Entity Central Index Key Other securities gross unrealized gains. Other securities gross unrealized losses. Total amount of accumulated unrealized gain on investments in debt and equity securities before taxes. Total amount of accumulated unrealized gain on investments in debt and equity securities before taxes. Carrying amount of debt securities accounted for as held-to-maturity, net of adjustments including, but not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized, and fair value hedge accounting adjustments, that have single maturity date. Financing receivables that are thirty to eighty nine days past due. The balance of financing receivables that were purchased impaired amount. Amount before tax of increase (decrease) in accumulated other comprehensive income (loss) related to the reclassification adjustment for other than temporary impairment (OTTI) related to factors other than credit loss on a previously impaired investment on held-to-maturity security. Other comprehensive income loss reclassification adjustment for realized gains losses included in net income before tax. Other comprehensive income loss net yield adjustment from cash flow hedges, before tax. Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income of unrealized holding gain or loss on held to maturity securities arising during period. Other comprehensive income loss reclassification adjustment for realized gains losses included in net income tax. Other comprehensive income loss net yield adjustment from cash flow hedges, tax. Other comprehensive income amortization of defined benefit plan actuarial loss recognized in net periodic benefit cost tax effect. Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income (loss). Amount after tax of increase (decrease) in accumulated other comprehensive income (loss) related to the reclassification adjustment for other than temporary impairment (OTTI) related to factors other than credit loss on a previously impaired investment on held-to-maturity security. Other comprehensive income loss reclassification adjustment for realized gains losses included in net income net of tax. Other comprehensive income loss net yield adjustment from cash flow hedges, net of tax. Other comprehensive income amortization of defined benefit plan actuarial loss recognized in net periodic benefit cost net of tax. Amount before allowance of consumer installment revolving and home equity loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Document and entity information. Document And Entity Information [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Amount of domestic interest-bearing checking and savings accounts, which may include money market accounts, NOW accounts, interest-bearing corporate checking accounts, brokered deposits and other savings accounts. The obligation to issue shares of company common stock in connection with deferred compensation plans. Statement Of Financial Position [Abstract] Assets Assets [Abstract] Cash and due from banks Cash And Due From Banks Interest-bearing deposits at banks Interest Bearing Deposits In Banks Trading account Trading Securities Investment securities (includes pledged securities that can be sold or repledged of $488,200 at September 30, 2017; $1,203,473 at December 31, 2016) Marketable Securities [Abstract] Available for sale (cost: $11,369,815 at September 30, 2017; $13,338,301 at December 31, 2016) Available For Sale Securities Held to maturity (fair value: $3,247,954 at September 30, 2017; $2,451,222 at December 31, 2016) Held To Maturity Securities Other (fair value: $414,978 at September 30, 2017; $461,118 at December 31, 2016) Other Investments And Securities At Cost Total investment securities Investments Loans and leases Loans And Leases Receivable Gross Carrying Amount Unearned discount Loans And Leases Receivable Deferred Income Loans and leases, net of unearned discount Loans And Leases Receivable Net Of Deferred Income Allowance for credit losses Loans And Leases Receivable Allowance Loans and leases, net Loans And Leases Receivable Net Reported Amount Premises and equipment Property Plant And Equipment Net Goodwill Goodwill Core deposit and other intangible assets Finite Lived Intangible Assets Net Accrued interest and other assets Interest Receivable And Other Assets Total assets Assets Liabilities Liabilities [Abstract] Noninterest-bearing deposits Noninterest Bearing Deposit Liabilities Domestic Savings and interest-checking deposits Savings And Interest Checking Deposits Time deposits Time Deposits Deposits at Cayman Islands office Deposits Foreign Total deposits Deposits Federal funds purchased and agreements to repurchase securities Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Accrued interest and other liabilities Other Liabilities Long-term borrowings Long Term Debt Total liabilities Liabilities Shareholders' equity Stockholders Equity [Abstract] Preferred stock, $1.00 par, 1,000,000 shares authorized; Issued and outstanding: Liquidation preference of $1,000 per share: shares 731,500 at September 30, 2017 and December 31, 2016; Liquidation preference of $10,000 per share: 50,000 shares at September 30, 2017 and December 31, 2016 Preferred Stock Value Common stock, $.50 par, 250,000,000 shares authorized, 159,819,892 shares issued at September 30, 2017; 159,945,678 shares issued at December 31, 2016 Common Stock Value Common stock issuable, 27,019 shares at September 30, 2017; 32,403 shares at December 31, 2016 Common Stock Issuable Additional paid-in capital Additional Paid In Capital Retained earnings Retained Earnings Accumulated Deficit Accumulated other comprehensive income (loss), net Accumulated Other Comprehensive Income Loss Net Of Tax Treasury stock — common, at cost — 8,555,636 shares at September 30, 2017; 3,764,742 shares at December 31, 2016 Treasury Stock Value Total shareholders’ equity Stockholders Equity Total liabilities and shareholders’ equity Liabilities And Stockholders Equity Number of shares of common stock issuable in connection with deferred compensation plans. Statement [Table] Statement [Table] Class of Stock Statement Class Of Stock [Axis] Class of Stock Class Of Stock [Domain] Series A and Series C. Series A and Series C [Member] Series A And Series C [Member] Series D Preferred Stock [Member] Series D Preferred Stock [Member] Statement [Line Items] Statement [Line Items] Pledged securities that can be sold or repledged Securities Held As Collateral At Fair Value Investment securities, available for sale, amortized cost Available For Sale Securities Amortized Cost Investment securities, held to maturity, fair value Held To Maturity Securities Fair Value Other, fair value Federal Home Loan Bank Stock And Federal Reserve Bank Stock Preferred stock, par value Preferred Stock Par Or Stated Value Per Share Preferred stock, shares authorized Preferred Stock Shares Authorized Preferred stock, shares issued Preferred Stock Shares Issued Preferred stock, shares outstanding Preferred Stock Shares Outstanding Preferred stock, liquidation preference per share Preferred Stock Liquidation Preference Common stock, par value Common Stock Par Or Stated Value Per Share Common stock, shares authorized Common Stock Shares Authorized Common stock, shares issued Common Stock Shares Issued Common stock issuable, shares Common Stock Issuable Share Treasury stock, shares Treasury Stock Shares Interest expenses savings and interest checking deposits. Income Statement [Abstract] Interest income Interest And Dividend Income Operating [Abstract] Loans and leases, including fees Interest And Fee Income Loans And Leases Investment securities Interest And Dividend Income Securities By Taxable Status [Abstract] Fully taxable Interest Income Securities Taxable Exempt from federal taxes Interest Income Securities Tax Exempt Deposits at banks Interest Income Domestic Deposits Other Other Interest And Dividend Income Total interest income Interest And Dividend Income Operating Interest expense Interest Expense [Abstract] Savings and interest-checking deposits Interest Expenses Savings And Interest Checking Deposits Time deposits Interest Expense Time Deposits Deposits at Cayman Islands office Interest Expense Foreign Deposits Short-term borrowings Interest Expense Short Term Borrowings Long-term borrowings Interest Expense Long Term Debt Total interest expense Interest Expense Net interest income Interest Income Expense Net Provision for credit losses Provision For Loan And Lease Losses Net interest income after provision for credit losses Interest Income Expense After Provision For Loan Loss Other income Noninterest Income [Abstract] Mortgage banking revenues Fees And Commissions Mortgage Banking Service charges on deposit accounts Fees And Commissions Depositor Accounts Trust income Fees And Commissions Fiduciary And Trust Activities Brokerage services income Brokerage Commissions Revenue Trading account and foreign exchange gains Trading Gains Losses Gain (loss) on bank investment securities Gain Loss On Sale Of Securities Net Other revenues from operations Noninterest Income Other Operating Income Total other income Noninterest Income Other expense Noninterest Expense [Abstract] Salaries and employee benefits Labor And Related Expense Equipment and net occupancy Occupancy Net Outside data processing and software Information Technology And Data Processing FDIC assessments Federal Deposit Insurance Corporation Premium Expense Advertising and marketing Marketing And Advertising Expense Printing, postage and supplies Supplies And Postage Expense Amortization of core deposit and other intangible assets Amortization Of Intangible Assets Other costs of operations Other Noninterest Expense Total other expense Noninterest Expense Income before taxes Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest Income taxes Income Tax Expense Benefit Net income Net Income Loss Net income available to common shareholders Net Income Loss Available To Common Stockholders Basic [Abstract] Basic Net Income Loss Available To Common Stockholders Basic Diluted Net Income Loss Available To Common Stockholders Diluted Net income per common share Earnings Per Share [Abstract] Basic Earnings Per Share Basic Diluted Earnings Per Share Diluted Cash dividends per common share Common Stock Dividends Per Share Cash Paid Average common shares outstanding Weighted Average Number Of Shares Outstanding [Abstract] Basic Weighted Average Number Of Shares Outstanding Basic Diluted Weighted Average Number Of Diluted Shares Outstanding Statement Of Partners Capital [Abstract] Net income Other comprehensive income, net of tax and reclassification adjustments: Other Comprehensive Income Loss Net Of Tax Period Increase Decrease [Abstract] Net unrealized gains (losses) on investment securities Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax Cash flow hedges adjustments Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax Foreign currency translation adjustment Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax Defined benefit plans liability adjustments Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax Total other comprehensive income (loss) Other Comprehensive Income Loss Net Of Tax Total comprehensive income Comprehensive Income Net Of Tax Net change in accrued interest receivable, payable. The net cash outflow or inflow for the increase (decrease) of loan servicing advances. The noncash increase of investment securities held for sale resulting from securitization of residential mortgage loans. Statement Of Cash Flows [Abstract] Cash flows from operating activities Net Cash Provided By Used In Operating Activities Continuing Operations [Abstract] Adjustments to reconcile net income to net cash provided by operating activities Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Depreciation and amortization of premises and equipment Depreciation And Amortization Amortization of capitalized servicing rights Amortization Of Mortgage Servicing Rights M S Rs Provision for deferred income taxes Deferred Income Tax Expense Benefit Asset write-downs Asset Impairment Charges Net gain on sales of assets Gains Losses On Sales Of Assets Net change in accrued interest receivable, payable Net Change In Accrued Interest Receivable Payable Net change in other accrued income and expense Increase Decrease In Other Operating Capital Net Net change in loans originated for sale Increase Decrease In Loans Held For Sale Net change in trading account assets and liabilities Increase Decrease In Financial Instruments Used In Operating Activities Net cash provided by operating activities Net Cash Provided By Used In Operating Activities Continuing Operations Cash flows from investing activities Net Cash Provided By Used In Investing Activities Continuing Operations [Abstract] Proceeds from sales of investment securities Available for sale Proceeds From Sale Of Available For Sale Securities Proceeds from sales of investment securities Other Proceeds From Sale Of Other Investments Proceeds from maturities of investment securities Available for sale Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities Proceeds from maturities of investment securities Held to maturity Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities Purchases of investment securities Available for sale Payments To Acquire Available For Sale Securities Purchases of investment securities Held to maturity Payments To Acquire Held To Maturity Securities Purchases of investment securities Other Payments To Acquire Other Investments Net decrease (increase) in loans and leases Payments For Proceeds From Loans And Leases Net increase in interest-bearing deposits at banks Proceeds From Payments For In Interest Bearing Deposits In Banks Capital expenditures, net Payments For Proceeds From Productive Assets Net decrease in loan servicing advances Net Increase Decrease In Loan Servicing Advances Other, net Payments For Proceeds From Other Investing Activities Net cash provided (used) by investing activities Net Cash Provided By Used In Investing Activities Continuing Operations Cash flows from financing activities Net Cash Provided By Used In Financing Activities Continuing Operations [Abstract] Net increase (decrease) in deposits Increase Decrease In Deposits Net increase (decrease) in short-term borrowings Proceeds From Repayments Of Short Term Debt Proceeds from long-term borrowings Proceeds From Issuance Of Long Term Debt Payments on long-term borrowings Repayments Of Long Term Debt Purchases of treasury stock Payments For Repurchase Of Common Stock Dividends paid — common Payments Of Dividends Common Stock Dividends paid — preferred Payments Of Dividends Preferred Stock And Preference Stock Other, net Proceeds From Payments For Other Financing Activities Net cash provided (used) by financing activities Net Cash Provided By Used In Financing Activities Continuing Operations Net increase (decrease) in cash and cash equivalents Cash And Cash Equivalents Period Increase Decrease Cash and cash equivalents at beginning of period Cash And Cash Equivalents At Carrying Value Cash and cash equivalents at end of period Supplemental disclosure of cash flow information Supplemental Cash Flow Information [Abstract] Interest received during the period Proceeds From Interest Received Interest paid during the period Interest Paid Income taxes paid during the period Income Taxes Paid Net