| Average assets (a) | $563B | $569.5B | — | $556.4B | $561.7B | $571.5B | $3.2B | $601.5B |
| Payments for (Proceeds from) Loans Receivable | — | -$378M | -$4.5B | $2.4B | $7.4B | $173M | $4.8B | $13.8B |
| Cash Provided by (Used in) Investing Activity, Including Discontinued Operation | -$10B | -$3.8B | — | -$980M | -$11.7B | -$820M | -$2.1B | -$10.6B |
| Federal Home Loan Bank advances | — | $0 | $3B | $0 | $3B | $1.1B | $0 | $10B |
| Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation | -$20.3B | — | — | -$7.9B | -$8B | — | — | -$8B |
| Securities available-for-sale | $3.8B | $564M | $0 | $1.2B | $90M | $0 | $1.9B | $7.7B |
| Interest and Dividend Income, Operating | $6.6B | $6.8B | $6.5B | $6.1B | $6.3B | $6.5B | $6.4B | $6.4B |
| Payments to Acquire Debt Securities, Available-for-Sale | $14.5B | $9.3B | $4.9B | $4.1B | $4.9B | $3.1B | $3.3B | $5.7B |
| Interest and Fee Income, Loans and Leases | $4.8B | $5B | $4.7B | $4.5B | $4.6B | $4.8B | $4.6B | $4.8B |
| Proceeds from Maturities, Prepayments and Calls of Held-to-Maturity Securities | $1.8B | $3.9B | $7.1B | $3.5B | $3.4B | $3.4B | $4.8B | $4.5B |
| Interest Income (Expense), Operating | $3.3B | $3.4B | $3.5B | $3.5B | $3.6B | $3.6B | $3.7B | $4B |
| Interest-bearing deposits | — | $7.5B | $4.7B | -$3.6B | $2.9B | $8.1B | $7.6B | -$3.9B |
| Noninterest Expense | $3.4B | $3.3B | $3.5B | $3.4B | $3.4B | $3.5B | $3.6B | $3.8B |
| Payments to Acquire Held-to-Maturity Securities | $877M | $95M | $717M | $31M | $3.9B | $1.2B | $1.5B | $3.3B |
| Repayments Maturities Of Federal Home Loan Bank Borrowings | $2B | $7B | $9B | $4B | $3B | $3B | $3.1B | $3B |
| Repayments Maturities Of Senior Debt | $0 | $600M | $2.4B | $750M | $2B | — | — | $3B |
| Common stock activity | $16M | — | $16M | — | $18M | — | $17M | $2.9B |
| Senior debt | $1.7B | $2.5B | $3.2B | $2.7B | $2.5B | $2.8B | $0 | $2.6B |
| Interest Paid, Net | $3.5B | $3.3B | $3.5B | $2.7B | $2.8B | $2.8B | $2.8B | $2.5B |
| Interest Paid, Excluding Capitalized Interest, Operating Activity | $3.5B | $3.3B | $3.5B | $2.7B | $2.8B | $2.8B | $2.8B | $2.5B |
| Noninterest-bearing deposits | -$3.5B | $0 | -$2B | -$272M | $885M | -$2B | — | -$2.3B |
| Goodwill Period Increase Decrease | — | — | — | — | — | — | — | $2.3B |
| Cash Provided by (Used in) Operating Activity, Including Discontinued Operation | $1B | $3.3B | $1.8B | -$509M | $1.5B | $2.7B | $757M | $1.9B |
| Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale | $1.7B | $2.3B | $1.6B | $1.7B | $1.7B | $2.2B | $1B | $1.9B |
| Increase in accrued expenses and other liabilities | -$671M | — | -$810M | -$1.6B | -$784M | — | — | -$1.8B |
| Interest Expense, Deposits | $2.1B | $2.2B | $2B | $1.8B | $1.8B | $2B | $1.9B | $1.7B |
| Net Income Loss Available To Common Stockholders | $1.4B | $1.4B | $1.5B | $1.4B | $1.5B | $1.7B | $1.9B | $1.7B |
| Reclassifications Net of Tax | $1.4B | $1.4B | $1.5B | $1.4B | $1.5B | $1.7B | $1.9B | $1.7B |
| Payment for (Proceeds from) Other Investing Activity | $266M | $230M | $516M | $145M | $525M | $827M | $1.1B | $1.6B |
| Subordinated debt | — | — | — | $0 | — | — | — | $1.5B |
| Comprehensive Income Including Noncontrolling Interest | $2.1B | $3.9B | $152M | $2.8B | $2.2B | $2.4B | $2.7B | $1.4B |
| Comprehensive Income Attributable to Parent | $2.1B | $3.9B | $152M | $2.8B | $2.2B | $2.4B | $2.7B | $1.4B |
| Comprehensive Income Including Noncontrolling Interest | $2.1B | $3.9B | $152M | $2.8B | $2.2B | $2.4B | $2.7B | $1.4B |
| Comprehensive income (loss), including noncontrolling interest | $2.1B | $3.9B | $152M | $2.8B | $2.2B | $2.4B | $2.7B | $1.4B |
| Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest | $2.1B | $3.9B | $152M | $2.8B | $2.2B | $2.4B | $2.7B | $1.4B |
| Comprehensive Income (Loss), Total | $2.1B | $3.9B | $152M | $2.8B | $2.2B | $2.4B | $2.7B | $1.4B |
| Comprehensive Income, Including Noncontrolling Interest | $2.1B | $3.9B | $152M | $2.8B | $2.2B | $2.4B | $2.7B | $1.4B |
| Comprehensive Income Including Noncontrolling Interest | $2.1B | $3.9B | $152M | $2.8B | $2.2B | $2.4B | $2.7B | $1.4B |
| Total Comprehensive Income | $2.1B | $3.9B | $152M | $2.8B | $2.2B | $2.4B | $2.7B | $1.4B |
| Comprehensive Income (Loss), Net of Tax, Attributable to Parent | $2.1B | $3.8B | $135M | $2.8B | $2.2B | $2.4B | $2.7B | $1.4B |
| Other Comprehensive Income (Loss) | $2.1B | $3.8B | $135M | $2.8B | $2.2B | $2.4B | $2.7B | $1.4B |
| Interest and Dividend Income, Securities, Operating | $1B | $1.1B | $1.1B | $1.1B | $1.2B | $1.2B | $1.2B | $1.2B |
| Payments for Repurchase of Common Stock | $113M | $130M | $221M | $262M | $336M | $334M | $406M | $796M |
| Card and cash management | $706M | $698M | $695M | $692M | $737M | $737M | $733M | $738M |
| Dividends, Common Stock, Cash | $623M | $646M | $644M | $639M | $642M | $678M | $676M | $696M |
| Payments of Ordinary Dividends, Common Stock | $623M | $646M | $644M | $639M | $642M | $678M | $676M | $696M |
| Cash Dividends, Common Stock | $623M | $646M | $644M | $639M | $642M | $678M | $676M | $696M |
| Cash Provided by (Used in) Financing Activity, Including Discontinued Operation | -$11.3B | — | -$3.9B | -$6.4B | $2.2B | $6.6B | $2.2B | $644M |
| Payment for Acquisition, Loan, Held-for-Investment | $586M | $730M | $320M | $403M | $450M | $739M | $720M | $600M |
| Increase (Decrease) in Loan, Held-for-Sale | $249M | — | $133M | $297M | $658M | — | $854M | -$571M |
| Stock Issued During Period, Value, Treasury Stock Reissued And Share-Based Payment Arrangement, After Forfeiture | -$93M | -$114M | $626M | -$36M | -$326M | -$323M | $1.8B | -$568M |
| Other Comprehensive Income (Loss), Before Tax | $784M | $3.1B | — | $1.8B | $727M | $802M | $892M | -$482M |
| Increase (Decrease) in Other Operating Assets and Liabilities, Net | -$232M | — | -$1.1B | $22M | -$148M | -$253M | -$329M | -$480M |
| Increase (Decrease) in Other Operating Assets | — | -$1.6B | — | -$964M | -$818M | -$863M | — | -$474M |
| Equipment | $356M | $357M | $473M | $384M | $394M | $416M | $412M | $415M |
| Other comprehensive income (loss) | $596M | $2.4B | — | $1.3B | $555M | $605M | $669M | -$365M |
| Lending and deposit services | $304M | $320M | $330M | $316M | $317M | $335M | $342M | $340M |
| OCI Cash Flow Hedge After Reclassification Before Tax | $308M | $1.5B | — | $825M | $485M | $136M | $54M | -$332M |
| Gross charge-offs | $375M | $376M | $354M | $312M | $324M | $284M | $256M | $309M |
| Short-term borrowings/(repayments) less than 90 days — net | -$224M | $633M | — | $419M | -$270M | $621M | -$1.1B | $290M |
| Proceeds from (Payments for) Federal Funds Sold and Securities Purchased under Agreements to Resell, Net | $171M | -$773M | — | -$445M | $257M | -$669M | $1.3B | $260M |
| Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) | $262M | $286M | $250M | $205M | $198M | $179M | $162M | $253M |
| Acquisition PSL reserves | — | — | — | — | — | — | — | $229M |
| Provision For Credit Losses | $235M | $243M | $156M | $219M | $254M | $167M | $139M | $210M |
| Contractually specified servicing fees, late charges and ancillary fees | $200M | $200M | $100M | $200M | $200M | $100M | $200M | $200M |
| Provision for credit losses | $204M | $235M | $155M | $260M | $171M | $136M | $93M | $188M |
| Proceeds from Sale, Loan, Held-for-Investment | $141M | $138M | $261M | $143M | $150M | $281M | $302M | $177M |
| OCI Available-for-Sale Securities Adjustment, Before Tax | $475M | $1.6B | — | $929M | $263M | $667M | $519M | -$159M |
| OCI Available-for-Sale Securities Adjustment Before Tax | $475M | $1.6B | — | $929M | $263M | $667M | $519M | -$159M |
| OCI Available-for-Sale Debt Securities, Before Tax | $475M | $1.6B | — | $929M | $263M | $667M | $519M | -$159M |
| OCI Unrealized Gain (Loss) on Securities, Pre-tax | $475M | $1.6B | — | $929M | $263M | $667M | $519M | -$159M |
| Financing — other | — | — | — | $0 | — | — | — | $154M |
| Total other income | $332M | $69M | $175M | $137M | $212M | $198M | $217M | $125M |
| Residential and commercial mortgage | $131M | $181M | $122M | $134M | $128M | $161M | $148M | $118M |
| Tax expense (benefit) | $188M | $739M | — | $423M | $172M | $197M | $223M | -$117M |
| Other Comprehensive Income Tax | $188M | $739M | — | $423M | $172M | $197M | $223M | -$117M |
| Other Comprehensive Income (Loss), Tax | $188M | $739M | — | $423M | $172M | $197M | $223M | -$117M |
| Changes in fair value of mortgage servicing rights | $66M | $274M | — | $191M | $137M | $94M | $70M | $108M |
| Increase (Decrease) in Debt Securities, Trading, and Equity Securities, FV-NI | — | $662M | -$287M | $1.5B | $151M | $1.6B | $673M | -$105M |
| Deferred taxes | — | -$68M | — | -$47M | -$11M | -$10M | — | -$102M |
| Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery | $113M | $90M | $104M | $107M | $126M | $105M | $94M | $101M |
| Lease Income | $93M | $99M | $99M | $94M | $93M | $97M | $99M | $100M |
| Initial allowance for credit losses on newly purchased credit-deteriorated assets during the period | — | — | — | — | — | — | — | $93M |
| Interest income on lease receivables | $88M | $92M | $91M | $85M | $85M | $89M | $91M | $92M |
| Payments to Acquire Businesses, Net of Cash Acquired | — | — | — | $0 | — | — | — | $80M |
| Dividends, Preferred Stock, Cash | $95M | $82M | $94M | $71M | $83M | $71M | $83M | $73M |
| Payments of Ordinary Dividends, Preferred Stock and Preference Stock | $95M | $82M | $94M | $71M | $83M | $71M | $83M | $73M |
| Stockholders' Equity, Other | -$29M | -$29M | -$24M | $99M | -$39M | -$28M | — | -$69M |
| Acquired gross charge-offs | — | — | — | $0 | — | — | — | $45M |
| Restricted stock acquisition consideration | — | — | — | — | — | — | — | $29M |
| Total net securities (losses) | -$499M | $0 | -$2M | -$2M | — | — | -$7M | $28M |
| Change in federal funds purchased and securities sold under repurchase agreements | -$11M | — | — | -$3M | -$33M | $132M | — | -$28M |
| Net investment hedges | -$2M | -$68M | $83M | -$41M | -$83M | $28M | -$5M | $27M |
| Common and treasury stock | $9M | $27M | $9M | $25M | $9M | $27M | $9M | $26M |
| Provision for (recapture of) credit losses | $45M | $7M | $0 | -$46M | $84M | $16M | $43M | $14M |
| OCI Attributable to Noncontrolling Interest | $18M | $15M | $17M | $18M | $16M | $14M | $13M | $12M |
| Less: comprehensive income attributable to noncontrolling interest | $18M | $15M | $17M | $18M | $16M | $14M | $13M | $12M |
| Net Income Loss Attributable To Noncontrolling Interest | $18M | $15M | $17M | $18M | $16M | $14M | $13M | $12M |
| Comprehensive Income Attributable to Noncontrolling Interests | $18M | $15M | $17M | $18M | $16M | $14M | $13M | $12M |
| Comprehensive Income, Noncontrolling Interest | $18M | $15M | $17M | $18M | $16M | $14M | $13M | $12M |
| Earnings allocated to participating share awards | $7M | $10M | $9M | $9M | $10M | $12M | $12M | $11M |
| Lease income — operating leases | $5M | $7M | $8M | $9M | $8M | $8M | $8M | $8M |
| OCI Pension Unamortized Gain (Loss), Pre-tax | -$1M | $0 | -$22M | $2M | $19M | -$1M | -$320M | -$8M |
| OCI Available-for-Sale Securities, Tax | -$105M | — | — | $0 | $0 | $0 | — | $6M |
| Other | $1M | $4M | — | $3M | $6M | -$2M | — | -$4M |
| Debt Securities, Available-for-Sale, Realized Loss | $497M | $3M | $2M | $4M | — | — | $37M | $3M |
| Cash flow hedges, Gain or (loss) reclassified from accumulated OCI into income | $20M | $5M | $5M | $5M | -$3M | -$4M | -$5M | -$3M |
| Other Comprehensive Income (Loss), Other Gains and Losses, Net of Tax | $0 | -$1M | $4M | -$1M | -$2M | -$2M | -$1M | $1M |
| Preferred stock discount accretion and redemptions | $2M | $2M | $2M | $2M | $2M | $2M | $3M | $1M |
| Number of countries outside the US where strategic international offices are held | — | — | — | 400.0% | — | — | — | 400.0% |
| Number of reportable segments | — | — | — | 3.00 | — | — | — | 3.00 |
| Common Stock Dividends Per Share Declared | $1.6 | $1.6 | $1.6 | $1.6 | $1.6 | $1.7 | $1.7 | $1.7 |
| Common Stock Dividends Per Share | $1.6 | $1.6 | $1.6 | $1.6 | $1.6 | $1.7 | $1.7 | $1.7 |
| Dividends per share declared | $1.6 | $1.6 | $1.6 | $1.6 | $1.6 | $1.7 | $1.7 | $1.7 |
| Dividends per share declared | $1.6 | $1.6 | $1.6 | $1.6 | $1.6 | $1.7 | $1.7 | $1.7 |
| Common Stock Dividends Per Share Declared | $1.6 | $1.6 | $1.6 | $1.6 | $1.6 | $1.7 | $1.7 | $1.7 |
| Dividends declared (in dollars per share) | $1.6 | $1.6 | $1.6 | $1.6 | $1.6 | $1.7 | $1.7 | $1.7 |
| Common Stock Dividends Per Share Declared | $1.6 | $1.6 | $1.6 | $1.6 | $1.6 | $1.7 | $1.7 | $1.7 |
| Common Stock Dividends Per Share Declared | $1.6 | $1.6 | $1.6 | $1.6 | $1.6 | $1.7 | $1.7 | $1.7 |
| Income Taxes Paid, Net | $97.3M | $97.3M | $97.3M | $176M | $176M | $176M | $176M | — |
| Federal | $261.5M | $261.5M | $261.5M | $336.5M | $336.5M | $336.5M | $336.5M | — |
| Foreign | $13M | $13M | $13M | $2.5M | $2.5M | $2.5M | $2.5M | — |
| Federal | $0 | $0 | $0 | -$1.5M | -$1.5M | -$1.5M | -$1.5M | — |
| State | -$7.3M | -$7.3M | -$7.3M | -$9M | -$9M | -$9M | -$9M | — |
| Assumed health care cost trend rate Year ultimate trend reached | 50825.0% | 50825.0% | 50825.0% | 50900.0% | 50900.0% | 50900.0% | 50900.0% | — |
| Minimum annual earnings credit per participant | $500 | $500 | $500 | $500 | $500 | $500 | $500 | — |
| Defined Contribution Plan, eligible compensation for deferral in absence of election otherwise (percent) | 1.0% | 1.0% | 1.0% | 1.5% | 1.5% | 1.5% | 1.5% | — |
| Depreciation | $228M | $228M | $228M | $250.3M | $250.3M | $250.3M | $250.3M | — |
| Effective tax rates | $0 | $0 | $0 | $0 | $0 | $0 | $0 | — |
| Income taxes at U.S. statutory rate of 21% | $0.1 | $0.1 | $0.1 | $0.1 | $0.1 | $0.1 | $0.1 | — |
| Foreign operations | 0.1% | 0.1% | 0.1% | -0.0% | -0.0% | -0.0% | -0.0% | — |
| Effective Income Tax Rate Reconciliation, Low Income Housing Tax Credit, Amount | $25.5M | $25.5M | $25.5M | $34.5M | $34.5M | $34.5M | $34.5M | — |
| Effective Income Tax Rate Reconciliation, Low Income Housing Tax Credit, Percent | 0.4% | 0.4% | 0.4% | 0.4% | 0.4% | 0.4% | 0.4% | — |
| Effective Income Tax Rate Reconciliation, New Markets Tax Credit, Amount | $19M | $19M | $19M | $8.8M | $8.8M | $8.8M | $8.8M | — |
| Effective Income Tax Rate Reconciliation, New Markets Tax Credit, Percent | 0.3% | 0.3% | 0.3% | 0.1% | 0.1% | 0.1% | 0.1% | — |
| Other | -0.3% | -0.3% | -0.3% | -0.1% | -0.1% | -0.1% | -0.1% | — |
| Effective Income Tax Rate Reconciliation Other Reconciling Items Percent | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | — |
| State income taxes – net of federal income tax benefit | $0 | $0 | $0 | $0 | $0 | $0 | $0 | — |
| Changes in unrecognized tax benefits | 0.1% | 0.1% | 0.1% | -0.2% | -0.2% | -0.2% | -0.2% | — |
| Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent | 0.3% | 0.3% | 0.3% | 0.3% | 0.3% | 0.3% | 0.3% | — |
| Other | -$1.3M | -$1.3M | -$1.3M | $2M | $2M | $2M | $2M | — |
| Currency exchange and other | — | — | — | $6.8M | $6.8M | $6.8M | $6.8M | — |
| Federal taxes | $33M | $33M | $33M | $96.3M | $96.3M | $96.3M | $96.3M | — |
| Foreign | $8.3M | $8.3M | $8.3M | $14.3M | $14.3M | $14.3M | $14.3M | — |
| State taxes | $56M | $56M | $56M | $65.5M | $65.5M | $65.5M | $65.5M | — |
| Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount | $380.3M | $380.3M | $380.3M | $445.5M | $445.5M | $445.5M | $445.5M | — |
| Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount | -$19.3M | -$19.3M | -$19.3M | -$9.8M | -$9.8M | -$9.8M | -$9.8M | — |
| Effective Income Tax Rate Reconciliation, Other Adjustments, Amount | -$1.3M | -$1.3M | -$1.3M | -$5.3M | -$5.3M | -$5.3M | -$5.3M | — |
| Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount | $50M | $50M | $50M | $49.5M | $49.5M | $49.5M | $49.5M | — |
| Changes in unrecognized tax benefits | $2.8M | $2.8M | $2.8M | -$17.3M | -$17.3M | -$17.3M | -$17.3M | — |
| Effective Income Tax Rate Reconciliation, Tax Credit, Other, Amount | $23M | $23M | $23M | $21M | $21M | $21M | $21M | — |
| Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount | $25.8M | $25.8M | $25.8M | $23.3M | $23.3M | $23.3M | $23.3M | — |
| Income Taxes Paid, Net | $97.3M | $97.3M | $97.3M | $176M | $176M | $176M | $176M | — |
| Increase in Carrying Amount of Redeemable Preferred Stock | $0 | $0 | — | $0 | $0 | $0 | — | $0 |
| Other | $0 | $1M | -$1M | $1M | $1M | $0 | $0 | $0 |
| Operating Lease Payments | $103.3M | $103.3M | $103.3M | $99M | $99M | $99M | $99M | — |
| Pension plan, decline in discount rate (percent) | 0.1% | 0.1% | 0.1% | 0.1% | 0.1% | 0.1% | 0.1% | — |
| Sensitivity analysis of fair value, inputs change for fair value | $0 | $0 | $0 | $0 | $0 | $0 | $0 | — |
| Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Weighted Average Grant Date Fair Value | $35.44 | $35.44 | $35.44 | $47.73 | $47.73 | $47.73 | $47.73 | — |
| Vested, grant-date fair value | $53.5M | $53.5M | $53.5M | $64M | $64M | $64M | $64M | — |
| Shares exchange program, percentage of shares monetized | 50.0% | — | — | — | — | — | — | — |
| Total Depreciation And Amortization | $262.8M | $262.8M | $262.8M | $288M | $288M | $288M | $288M | — |
| Loans reclassified to held for sale | $50M | $27M | $37M | $90M | $18M | $128M | $84M | $0 |
| Unrecognized tax benefits, settlements | $250K | $250K | $250K | $10M | $10M | $10M | $10M | — |
| Additions for tax positions of prior years | $8.8M | $8.8M | $8.8M | $500K | $500K | $500K | $500K | — |
