Accounting Policies [Abstract] Accounting Policies [Abstract] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Receivable Type [Axis] Receivable Type [Axis] Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract] Outstanding principal and carrying value of acquired loans recorded at fair value Accrued Investment Income Receivable Accrued interest receivable Accumulated Defined Benefit Plans Adjustment [Member] Defined Benefit Plans [Member] Accumulated net unrealized investment gain loss all other. Accumulated Net Unrealized Investment Gain Loss All Other [Member] Investment Securities All Other [Member] Accumulated net unrealized investment gain loss with OTTI. Accumulated Net Unrealized Investment Gain Loss With Otti [Member] Investment Securities With OTTI [Member] Accumulated Other Adjustment [Member] Accumulated Other Adjustment [Member] Accumulated Other Adjustment [Member] Accumulated Other Comprehensive Income (Loss), before Tax Ending balance Beginning balance Accumulated Other Comprehensive Income Loss Income Tax Accumulated Other Comprehensive Income Loss Income Tax Ending balance Beginning balance Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss), Net of Tax Ending Balance Beginning balance Accumulated other comprehensive income (loss), net Accumulated Other Comprehensive Income (Loss) [Table] Schedule of Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Member] Accumulated other comprehensive income (loss), net [Member] Acquired financing receivable. Acquired Financing Receivable [Member] Acquired [Member] Acquired loans at fair value carrying amount. Acquired Loans At Fair Value Carrying Amount Carrying amount Acquired loans at fair value outstanding principal. Acquired Loans At Fair Value Outstanding Principal Outstanding principal balance Additional Collateral, Aggregate Fair Value Fair value of additional collateral to be posted for derivative financial instruments Additional Paid in Capital Additional paid-in capital Additional Paid-in Capital [Member] Additional paid-in capital [Member] Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Compensation expense, net Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities Allocated. Allocated [Member] Allocated [Member] Other Segments [Member] Other Segments [Member] Allowance for Loan and Lease Losses, Loans Sold Allowance related to loans securitized and sold Allowance for Loan and Lease Losses Write-offs, Net Net charge-offs Amendment Flag Amendment Flag Amortization of Intangible Assets Amortization of core deposit and other intangible assets Amortization of Mortgage Servicing Rights (MSRs) Amortization of capitalized servicing rights Amortized cost and estimated fair value of debt securities by contractual maturity. Amortized Cost And Estimated Fair Value Of Debt Securities By Contractual Maturity Table [Text Block] Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity Amortized cost and estimated fair value of investment securities. Amortized Cost And Estimated Fair Value Of Investment Securities Table [Text Block] Amortized Cost and Estimated Fair Value of Investment Securities Amortized Cost and Fair Value Debt Securities [Abstract] Amortized Cost and Fair Value Debt Securities [Abstract] Amortized Cost and Fair Value Debt Securities [Abstract] Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive securities excluded from computation of earnings per share Asset Impairment Charges Asset write-downs Assets Assets Total assets Assets [Abstract] Assets Assets, Fair Value Disclosure Total assets Assets taken in foreclosure of defaulted loans measured at fair value on a nonrecurring basis. Assets Taken In Foreclosure Of Defaulted Loans Measured At Fair Value On Nonrecurring Basis Assets taken in foreclosure of defaulted loans measured at fair value on a nonrecurring basis Automobile Loan [Member] Automobile [Member] Automobile Loans Securitized and Sold Automobile Loans Securitized and Sold Automobile loans securitized and sold Available-for-sale Debt Securities, Amortized Cost Basis Total Available-for-sale Securities Available for sale (cost: $4,555,109 at September 30, 2013; $4,643,070 at December 31, 2012) Investment securities available for sale, estimated fair value Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Investment securities available for sale, gross unrealized gains Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Investment securities available for sale, gross unrealized losses Available-for-sale Securities, Amortized Cost Basis Investment securities, available for sale, amortized cost Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or More Aggregate Losses Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Available For Sale Securities Continuous Unrealized Losses Position Less Than Twelve Months Aggregate Losses Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Estimated fair value, Less than 12 months Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Estimated fair value, 12 months or more Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis Due after five years through ten years Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value Due after five years through ten years Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis Due after one year through five years Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value Due after one year through five years Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis Due after ten years Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value Due after ten years Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract] Debt securities available for sale: Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract] Debt securities available for sale: Available-for-sale Securities, Debt Maturities, Single Maturity Date Total available for sale (fair value) Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis Total available for sale (amortized cost) Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis Due in one year or less Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value Due in one year or less Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis Mortgage-backed securities available for sale Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value Mortgage-backed securities available for sale Available-for-sale Securities, Debt Securities Total Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds Privately issued mortgage backed securities sold Average Assets Average Asset Average Assets Bayview Financial [Member] Bayview Financial [Member] Bayview Financial [Member] Bayview Lending Group And Bayview Financial [Member] Bayview Lending Group And Bayview Financial [Member] Bayview Lending Group And Bayview Financial [Member] Bayview Lending Group [Member] Bayview Lending Group [Member] Bayview Lending Group [Member] Brokerage Commissions Revenue Brokerage services income Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition Contingent Consideration At Fair Value1 Business Acquisition Contingent Consideration At Fair Value1 Total consideration to be paid Business Acquisition [Line Items] Business Acquisition [Line Items] Business Banking Segment. Business Banking [Member] Business Banking [Member] Business Combination Disclosure [Text Block] Acquisitions Business Combinations [Abstract] Business Combinations [Abstract] Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Cost Expensed Merger-related expenses Total merger-related expenses Reported Value Measurement [Member] Carrying Amount [Member] Carrying value of loans in securitization trusts. Carrying Value Of Loans In Securitization Trusts Carrying value of loans in the Securitization trusts Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents at end of period Cash and cash equivalents at beginning of period Cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Net increase (decrease) in cash and cash equivalents Cash and Due from Banks Cash and due from banks Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Supplemental schedule of noncash investing and financing activities Cash less exercise. Cash Less Exercise [Member] Cash Less Exercise [Member] Cash [Member] Cash [Member] Certain loans acquired in transfer accounted for as debt securities accretable yield accretion. Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield Accretion Table [Text Block] Summary of Changes in Accretable Yield for Acquired Loans Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Balance at end of period Balance at beginning of period Certain loans acquired in transfer not accounted for as debt securities accretable yield interest income. Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Interest Income Interest income Certain loans acquired in transfer not accounted for as debt securities accretable yield interest other increase decrease. Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Interest Other Increase Decrease Other Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward] Summary of changes in Accretable Yield for acquired loans Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications (to) from Nonaccretable Difference Reclassifications from nonaccretable balance, net Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value Contractual principal and interest payments Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net Purchased impaired Change in fair value of nonrecurring fair value measured loans for charge-offs and impairment reserves. Change In Fair Value Of Nonrecurring Fair Value Measured Loans For Charge Offs And Impairment Reserves Change in fair value of nonrecurring fair value measured loans for charge-offs and impairment reserves Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments Derivatives in fair value hedging relationships, Derivatives Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge Derivatives in fair value hedging relationships, Hedged item The tabular disclosure of changes in allowance for credit losses. Changes In Allowance For Credit Losses Table [Text Block] Changes in Allowance for Credit Losses Changes in credit losses associated with debt securities for which other-than-temporary impairment losses. Changes In Credit Losses Associated With Debt Securities For Which Other Than Temporary Impairment Losses Table [Text Block] Changes in Credit Losses Associated with Debt Securities for Which OTTI Losses The tabular disclosure of changes in level 3 assets and liabilities measured at estimated fair value on recurring basis. Changes In Level Three Assets And Liabilities Measured At Estimated Fair Value On Recurring Basis Table [Text Block] Changes in Level 3 Assets and Liabilities Measured at Estimated Fair Value on Recurring Basis Class Of Financing Receivables [Member] Class Of Financing Receivables [Member] Impaired Financing Receivable With Related Allowance [Member] Class Of Financing Receivable With No Related Allowance [Member] Class Of Financing Receivable With No Related Allowance [Member] Impaired Financing Receivable with No Related Allowance [Member] Class of Stock [Domain] Class of Stock [Domain] Class of Stock [Line Items] Class of Stock [Line Items] Class of Warrant or Right [Axis] Class of Warrant or Right [Axis] Class of Warrant or Right [Domain] Class of Warrant or Right [Domain] Class of Warrant or Right, Number of Securities Called by Warrants or Rights Cashless warrants exercised Exercise of warrants into shares of common stock Class of Warrant or Right, Outstanding Warrants and rights outstanding Clearinghouse Credit Facilities [Member] Clearinghouse Credit Facilities [Member] Clearinghouse Credit Facilities [Member] Collateral Already Posted, Aggregate Fair Value Fair value of collateral already posted for derivative financial instruments Collateralized Debt Obligations [Member] Collateralized Debt Obligations [Member] Collectively evaluated for impairment. Collectively Evaluated For Impairment [Member] Collectively Evaluated for Impairment [Member] Combination of concession types. Combination Of Concession Types [Member] Combination of concession types [Member] Combined Outstanding Principal Amount Of Mortgage Backed Securities Issued By Qualified Special Purpose Trusts Held By Unrelated Parties Combined Outstanding Principal Amount Of Mortgage Backed Securities Issued By Qualified Special Purpose Trusts Held By Unrelated Parties Combined outstanding principal amount of mortgage-backed securities issued by qualified special purpose trust held by unrelated parties Commercial Banking Segment. Commercial Banking [Member] Commercial Banking [Member] Commercial financial leasing. Commercial Financial Leasing [Member] Commercial, Financial, Leasing, etc. [Member] Commercial real estate excluding residential builder and developer and other construction. Commercial Real Estate Excluding Residential Builder And Developer And Other Construction [Member] Commercial [Member] Commercial Real Estate [Member] Commercial Real Estate [Member] Commercial Real Estate Portfolio Segment [Member] Real Estate Commercial [Member] Commercial Real Estate Segment. Commercial Real Estate Segment [Member] Commercial Real Estate [Member] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Text Block] Commitments and contingencies Commitments regarding Commercial letters of credit. Commitments Regarding Commercial Letters Of Credit Commercial letters of credit Commitments regarding Financial guarantees and indemnification contracts. Commitments Regarding Financial Guarantees And Indemnification Contracts Financial guarantees, indemnification contracts and other The tabular disclosure of commitments. Commitments Table [Text Block] Company's Significant Commitments Commitments to Extend Credit. Commitments To Extend Credit [Abstract] Commitments to extend credit Commitments to extend credit for Commercial and other. Commitments To Extend Credit For Commercial And Other Commercial and other Commitments to extend credit for Commercial real estate loans to be sold. Commitments To Extend Credit For Commercial Real Estate Loans To Be Sold Commercial real estate loans to be sold Commitments to extend credit for Home equity lines of credit. Commitments To Extend Credit For Home Equity Lines Of Credit Home equity lines of credit Commitments to extend credit for Other commercial real estate and construction. Commitments To Extend Credit For Other Commercial Real Estate And Construction Other commercial real estate and construction Commitments to extend credit for Other residential real estate. Commitments To Extend Credit For Other Residential Real Estate Other residential real estate Commitments to extend credit for Residential real estate loans to be sold. Commitments To Extend Credit For Residential Real Estate Loans To Be Sold Residential real estate loans to be sold Commitments to originate real estate loans for sale. Commitments To Originate Real Estate Loans For Sale Commitments to originate real estate loans for sale Commitments to sell real estate loans. Commitments To Sell Real Estate Loans [Member] Commitments to sell real estate loans [Member] Commitments To Sell Real Estate Loans Notional Amount. Commitments To Sell Real Estate Loans Notional Amount Commitments to sell real estate loans Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards. Common Shares Outstanding Including Common Stock Issuable And Unvested Stock Based Compensation Awards Common and unvested stock-based compensation awards Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards Common Stock, Dividends, Per Share, Cash Paid Cash dividends per common share Common stock per share dividend amount The obligation to issue shares of Company common stock in connection with deferred compensation plans. Common Stock Issuable Common stock issuable, 41,261 shares at September 30, 2014; 47,231 shares at December 31, 2013 Common stock issuable. Common Stock Issuable [Member] Common stock issuable [Member] Number of shares of common stock issuable in connection with deferred Compensation plans. Common Stock Issuable Shares Common stock issuable, shares Common Stock [Member] Common stock [Member] Common Stock, Par or Stated Value Per Share Common stock, par value Common Stock, Shares Authorized Common stock, shares authorized Common Stock, Shares, Issued Common stock, shares issued Common Stock, Value, Issued Common stock, $.50 par, 250,000,000 shares authorized, 132,100,384 shares issued at September 30, 2014; 130,516,364 shares issued at December 31, 2013 Compensation and Retirement Disclosure [Abstract] Compensation and Retirement Disclosure [Abstract] The tabular disclosure of components of other comprehensive income loss. Components Of Other Comprehensive Income Loss Table [Text Block] Components of Other Comprehensive Income (Loss) and Amounts Reclassified from Accumulated Other Comprehensive Income (Loss) to Net Income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Total comprehensive income Total comprehensive income Comprehensive Income (Loss) Note [Text Block] Comprehensive income Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Consolidation, Policy [Policy Text Block] Consolidation Consolidation securitized trusts increase decrease investment securities held for sale. Consolidation Securitized Trusts Increase Decrease Investment Securities Held For Sale Securitization of residential mortgage loans allocated to Available-for-sale investment securities Consolidation Securitized Trusts Increase Decrease Investment Securities Held To Maturity Consolidation Securitized Trusts Increase Decrease Investment Securities Held To Maturity Securitization of residential mortgage loans allocated to Held to maturity investment securities Consumer Loan [Member] Consumer loans [Member] Consumer Loans Auto Financing Receivable [Member] Automobile [Member] Consumer Other Financing Receivable [Member] Other [Member] Consumer Portfolio Segment [Member] Consumer [Member] Cost Method Investments Cost method investment securities Credit Derivatives [Line Items] Credit Derivatives [Line Items] Credit risk derivative. Credit Risk Derivative [Member] Credit Risk Derivative [Member] Criticized accrual. Criticized Accrual [Member] Criticized Accrual [Member] Criticized nonaccrual. Criticized Nonaccrual [Member] Criticized Nonaccrual [Member] Current Fiscal Year End Date Current Fiscal Year End Date Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Disclosure [Text Block] Borrowings Debt Instrument, Basis Spread on Variable Rate Discount margin over LIBOR Debt Instrument, Interest Rate, Stated Percentage Interest rate of debt instrument Debt Instrument, Maturity Date Range, End Debt Maturity, End Year Debt Instrument, Maturity Date Range, Start Debt Maturity, Start Year Debt Security [Axis] Debt Security [Axis] Deferred Income Tax Expense (Benefit) Provision for deferred income taxes Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Amortization of prior service cost Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Actuarial Gain (Loss), before Tax Amortization of net actuarial loss Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan, Expected Return on Plan Assets Expected return on plan assets Defined Benefit Plan, Interest Cost Interest cost on projected benefit obligation Defined Benefit Plan, Net Periodic Benefit Cost Net periodic benefit cost Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Defined Benefit Plan, Service Cost Service cost Delinquency period for loan level collectability analysis consumer mortgage. Delinquency Period For Loan Level Collectability Analysis Consumer Mortgage Delinquency period for loan level collectability analysis consumer mortgage Deposits Deposits Total deposits Deposits, Foreign Deposits at Cayman Islands office Deposits at Cayman Islands office Deposits, Negotiable Order of Withdrawal (NOW) NOW accounts Deposits, Savings Deposits Savings deposits Depreciation, Nonproduction Depreciation and amortization of premises and equipment Derivative Asset, Fair Value of Collateral Counterparties posted collateral relating to positions Derivative, Average Fixed Interest Rate Weighted-Average Rate, Fixed Derivative, Average Remaining Maturity Average Maturity (in years) Derivative, Average Variable Interest Rate Weighted-Average Rate, Variable Derivative, by Nature [Axis] Derivative, by Nature [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Derivative Asset, Fair Value, Gross Asset Asset derivatives, Fair value Derivative Asset, Fair Value, Amount Not Offset Against Collateral Aggregate fair value of derivative financial instruments in asset position Derivative Asset, Fair Value, Amount Offset Against Collateral Net asset positions with counterparties