| Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation | — | — | — | $5.3B | — | — | — | $17.2B |
| Interest and Dividend Income, Operating | $11.3B | $11.9B | $11.7B | $11.4B | $13.8B | $16.8B | $16.7B | $16.2B |
| Interest and Fee Income, Loans and Leases | $10.0B | $10.5B | $10.4B | $10.2B | $12.4B | $15.2B | $15.2B | $14.7B |
| Increase (Decrease) in Deposits | — | — | — | $4.7B | — | — | — | $13.3B |
| Interest Income (Expense), Operating | $7.5B | $8.1B | $8.1B | $8.0B | $10.0B | $12.4B | $12.5B | $12.1B |
| Cash Provided by (Used in) Financing Activity, Including Discontinued Operation | — | $1.7B | $5.8B | -$218.0M | -$9.9B | -$2.3B | — | $11.1B |
| Noninterest Expense | $4.9B | $5.3B | $6.1B | $5.9B | $7.0B | $8.3B | $9.3B | $8.5B |
| Interest Income (Expense), after Provision for Loan Loss | $3.6B | $5.6B | $5.5B | $5.6B | -$1.4B | $9.7B | $8.3B | $8.1B |
| Cash Provided by (Used in) Operating Activity, Including Discontinued Operation | $6.2B | $6.5B | $2.4B | $4.7B | $6.1B | $9.2B | $7.8B | $6.0B |
| Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale | $3.0B | $3.4B | $3.1B | $3.1B | $5.8B | $4.4B | $4.6B | $5.8B |
| Payments to Acquire Debt Securities, Available-for-Sale | $4.1B | $4.8B | $5.5B | $2.8B | $3.8B | $6.0B | $5.6B | $5.7B |
| Gross charge-offs | $3.4B | $3.4B | — | $3.7B | $4.3B | $4.9B | — | $5.4B |
| Revolving Loans | $2.7B | $2.6B | — | $3.0B | $3.5B | $4.0B | — | $4.4B |
| Total provisions for credit losses | $3.9B | $2.5B | $2.6B | $2.4B | $11.4B | $2.7B | $4.1B | $4.1B |
| Interest Paid, Net | $3.4B | $3.3B | $3.4B | $3.2B | $3.4B | $4.2B | $4.1B | $4.0B |
| Interest Paid, Excluding Capitalized Interest, Operating Activity | $3.4B | $3.3B | $3.4B | $3.2B | $3.4B | $4.2B | $4.1B | $4.0B |
| Interest Expense, Deposits | $2.9B | $2.9B | $2.9B | $2.7B | $3.1B | $3.6B | $3.5B | $3.4B |
| Proceeds From Issuance Of Secured Debt | $0.0 | $997.0M | — | $1.7B | — | — | — | $3.0B |
| Increase (Decrease) in Other Operating Assets | — | -$1.4B | $1.3B | $9.0M | $708.0M | — | — | $3.0B |
| Payments for Repurchase of Common Stock | $163.0M | $161.0M | $161.0M | $375.0M | $167.0M | $1.0B | $2.5B | $2.8B |
| Treasury stock, value, acquired | $163.0M | $161.0M | — | $375.0M | $167.0M | $1.0B | — | $2.8B |
| Repayments of Secured Debt | $445.0M | $2.6B | — | $6.1B | — | $2.5B | — | $2.5B |
| Revenue | $1.5B | $1.4B | — | $1.5B | $1.8B | $2.3B | — | $2.4B |
| Amortized Cost | $1.0B | $1.3B | — | $1.1B | $2.1B | $2.3B | — | $2.2B |
| Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent | $597.0M | $1.8B | $1.1B | $1.4B | -$4.3B | $3.2B | $1.8B | $2.2B |
| Reclassifications Net of Tax | $531.0M | $1.7B | $1.0B | $1.3B | -$4.3B | $3.1B | $2.1B | $2.1B |
| Discount and interchange fees, net | $1.2B | $1.2B | $1.3B | $1.2B | $1.5B | $1.8B | $1.9B | $2.0B |
| Comprehensive Income (Loss), Net of Tax, Attributable to Parent | $430.0M | $5.2B | — | $3.2B | -$3.6B | $4.1B | — | $1.8B |
| Other Comprehensive Income (Loss) | $430.0M | $5.2B | — | $3.2B | -$3.6B | $4.1B | — | $1.8B |
| Proceeds from sales and paydowns | $1.4B | $890.0M | — | $724.0M | $1.7B | $870.0M | — | $1.7B |
| Payments For (Proceeds From) Sale Of Financing Receivable, Held-For-Investment | $6.6B | $5.3B | $11.4B | -$1.3B | $13.1B | $9.1B | $16.0B | -$1.7B |
| Marketing | $1.1B | $1.1B | $1.4B | $1.2B | $1.3B | $1.4B | $1.9B | $1.5B |
| Credit card marketing expense | $907.0M | $964.0M | — | $1.0B | $1.1B | $1.2B | — | $1.3B |
| Payment for Origination and Purchase, Loan, Held-for-Sale | $591.0M | $535.0M | $1.1B | $1.2B | $1.1B | $1.4B | $2.1B | $1.1B |
| Payments to Acquire Held-to-Maturity Securities | — | — | — | $0.0 | — | — | — | $1.1B |
| Uncollectible portion of billed finance charges and fees | $649.0M | $624.0M | — | $705.0M | $785.0M | $869.0M | — | $980.0M |
| Total Term Loans | $656.0M | $764.0M | — | $694.0M | $698.0M | $818.0M | — | $898.0M |
| Interest and Dividend Income, Securities, Operating | $700.0M | $733.0M | $753.0M | $770.0M | $784.0M | $823.0M | $841.0M | $832.0M |
| Service charges and other customer-related fees | $459.0M | $501.0M | $554.0M | $509.0M | $658.0M | $849.0M | $833.0M | $809.0M |
| Revenue (reduction) from other sources | $492.0M | $491.0M | — | $498.0M | $653.0M | $672.0M | — | $676.0M |
| Professional and outside services | $316.0M | $402.0M | $630.0M | $437.0M | $653.0M | $641.0M | $693.0M | $585.0M |
| Capital Expenditures | $289.0M | $312.0M | $356.0M | $348.0M | $399.0M | $387.0M | $444.0M | $553.0M |
| Payments to Acquire Property, Plant, and Equipment | $289.0M | $312.0M | $356.0M | $348.0M | $399.0M | $387.0M | $444.0M | $553.0M |
| Proceeds From Repayments Of Other Debt | $148.0M | -$196.0M | — | $7.0M | $166.0M | — | — | $538.0M |
| Senior and subordinated notes | $591.0M | $596.0M | $540.0M | $505.0M | $535.0M | $582.0M | $550.0M | $532.0M |
| Other Comprehensive Income (Loss), Before Tax | -$217.0M | $4.4B | — | $2.3B | $845.0M | $1.2B | — | -$519.0M |
| Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent | -$217.0M | $4.4B | — | $2.3B | $845.0M | $1.2B | — | -$519.0M |
| Dividends, Common Stock | $232.0M | $233.0M | — | $234.0M | $388.0M | $386.0M | — | $502.0M |
| Payments of Ordinary Dividends, Common Stock | $232.0M | $233.0M | $232.0M | $234.0M | $388.0M | $386.0M | $508.0M | $502.0M |
| Cash Dividends, Common Stock | $232.0M | $233.0M | $232.0M | $234.0M | $388.0M | $386.0M | $508.0M | $502.0M |
| Amortization of intangibles | $19.0M | $20.0M | $19.0M | $16.0M | $271.0M | $514.0M | $525.0M | $492.0M |
| Amortization of capitalized software and acquired intangible assets | — | — | — | — | $271.0M | $514.0M | — | $492.0M |
| Other comprehensive income/(loss) before reclassifications | -$410.0M | $3.1B | — | $1.5B | $521.0M | $787.0M | — | -$486.0M |
| OCI Before Reclassifications, Net of Tax | -$410.0M | $3.1B | — | $1.5B | $521.0M | $787.0M | — | -$486.0M |
| Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months | -$1.6B | — | — | -$571.0M | — | — | — | -$446.0M |
| Other Comprehensive Income (Loss), Net of Tax | -$167.0M | $3.4B | — | $1.8B | $710.0M | $902.0M | — | -$411.0M |
| OCI Attributable to Parent | -$167.0M | $3.4B | — | $1.8B | $710.0M | $902.0M | — | -$411.0M |
| Other comprehensive income/(loss) | -$167.0M | $3.4B | — | $1.8B | $710.0M | $902.0M | — | -$411.0M |
| Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent | -$167.0M | $3.4B | — | $1.8B | $710.0M | $902.0M | — | -$411.0M |
| OCI Net of Tax, Parent | -$167.0M | $3.4B | — | $1.8B | $710.0M | $902.0M | — | -$411.0M |
| Account balance, modified and subsequent default | — | — | — | — | $3.1B | — | — | $315.0M |
| Total other income | $252.0M | $244.0M | $278.0M | $255.0M | $361.0M | $294.0M | $354.0M | $313.0M |
| Net unrealized gains/(losses) on available-for-sale securities | — | — | — | $1.4B | — | — | — | -$311.0M |
| Debt Securities, Available-for-sale, Change in Present Value, Interest Income | $245.0M | $264.0M | $262.0M | $291.0M | $304.0M | $302.0M | $327.0M | $306.0M |
| Deferred taxes | -$469.0M | -$148.0M | -$352.0M | $262.0M | -$2.5B | — | -$503.0M | $244.0M |
| Payments to Acquire Businesses, Net of Cash Acquired | $0.0 | $0.0 | $0.0 | $318.0M | -$16.8B | -$1.0M | $0.0 | $241.0M |
| Term loan by year, year 3 | $225.0M | $238.0M | — | $170.0M | $166.0M | $193.0M | — | $238.0M |
| OCI Available-for-Sale Securities Adjustment | -$184.0M | $2.3B | — | $1.1B | $254.0M | $769.0M | — | -$234.0M |
| OCI - Available-for-Sale Securities Adjustment | -$184.0M | $2.3B | — | $1.1B | $254.0M | $769.0M | — | -$234.0M |
| Net unrealized debt securities gains (losses), net of tax | — | — | — | $1.1B | — | — | — | -$234.0M |
| Term loan by year, year 2 | $155.0M | $181.0M | — | $155.0M | $190.0M | $231.0M | — | $231.0M |
| OCI Cash Flow Hedge Before Reclassification and Tax | $24.0M | $1.4B | — | $886.0M | $518.0M | $199.0M | — | -$222.0M |
| Cash flow hedges | $24.0M | $1.4B | — | $886.0M | $518.0M | $199.0M | — | -$222.0M |
| Net addition to the allowance for credit losses | — | — | — | -$359.0M | $8.0B | — | — | $221.0M |
| Income Taxes Paid, Net | $276.3M | $276.3M | $276.3M | $3.0M | — | — | — | $184.0M |
| Income Taxes Paid, Net | $276.3M | $276.3M | $276.3M | $3.0M | — | — | — | $184.0M |
| Change in Other Liabilities | — | -$293.0M | -$487.0M | $178.0M | $360.0M | $821.0M | $730.0M | $181.0M |
| Other liabilities | — | -$293.0M | -$487.0M | $178.0M | $360.0M | $821.0M | $730.0M | $181.0M |
| Income tax credits and Other income tax benefits recognized in tax provision | $230.0M | $257.0M | — | $153.0M | $223.0M | $229.0M | — | $179.0M |
| Investment Program, Proportional Amortization Method, Applied, Amortization Expense | $178.0M | $171.0M | — | $159.0M | $180.0M | $176.0M | — | $179.0M |
| Net gains (losses) deferred | $18.0M | $1.1B | — | $670.0M | $392.0M | $149.0M | — | -$167.0M |
| Term loan by year, year 4 | $147.0M | $179.0M | — | $171.0M | $162.0M | $183.0M | — | $160.0M |
| Securitized debt obligations | $258.0M | $234.0M | $205.0M | $176.0M | $164.0M | $165.0M | $155.0M | $141.0M |
| Prior | $57.0M | $47.0M | — | $84.0M | $67.0M | $47.0M | — | $139.0M |
| Stock-based compensation | $105.0M | $127.0M | $144.0M | $177.0M | $225.0M | $174.0M | $200.0M | $131.0M |
| Share-based compensation expense related to employee stock plans | $107.0M | $125.0M | — | $169.0M | $214.0M | $168.0M | — | $130.0M |
| Term loan by year, year 5 | $58.0M | $66.0M | — | $109.0M | $93.0M | $92.0M | — | $127.0M |
| Proceeds from Issuance of Common Stock | $95.0M | $76.0M | $72.0M | $93.0M | $111.0M | $91.0M | $105.0M | $119.0M |
| Issuances of common stock and restricted stock, net of forfeitures | $95.0M | $76.0M | — | $93.0M | $111.0M | $91.0M | — | $119.0M |
| Revolving Loans Converted to Term | $31.0M | $31.0M | — | $36.0M | $60.0M | $94.0M | — | $118.0M |
| Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent | — | — | — | $540.0M | — | — | — | -$108.0M |
| Net unrealized gains on securities available for sale | -$60.0M | $733.0M | — | $345.0M | $83.0M | $253.0M | — | -$77.0M |
| Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent | -$243.0M | -$304.0M | — | -$276.0M | -$189.0M | -$115.0M | — | -$75.0M |
| Reclassification from AOCI, Net of Tax | -$243.0M | -$304.0M | — | -$276.0M | -$189.0M | -$115.0M | — | -$75.0M |
| Dividends, Preferred Stock, Cash | — | — | — | $57.0M | — | — | — | $73.0M |
| Sale of investments | $0.0 | $175.0M | — | $0.0 | $1.0M | — | — | $68.0M |
| Payments of Ordinary Dividends, Preferred Stock and Preference Stock | $57.0M | $57.0M | $57.0M | $57.0M | $65.0M | $57.0M | $73.0M | $57.0M |
| Unrealized Gain (Loss) on Derivatives, Net | $6.0M | $343.0M | — | $216.0M | $126.0M | $50.0M | — | -$55.0M |
| Increase Decrease In Accrued Interest Receivable Net | — | $83.0M | — | $67.0M | -$152.0M | $83.0M | $36.0M | -$32.0M |
| Other borrowings | $11.0M | $9.0M | $12.0M | $9.0M | $14.0M | $15.0M | $23.0M | $26.0M |
| Cash Provided by (Used in) Investing Activity, Including Discontinued Operation | -$7.5B | -$6.3B | -$14.2B | $845.0M | $16.5B | -$10.0B | -$7.8B | $26.0M |
| Amortization expense (benefit) | $18.0M | $21.0M | — | -$10.0M | $16.0M | $23.0M | — | -$20.0M |
| Participating Securities, Distributed and Undistributed Earnings (Loss), excluding Preferred Stock Dividends, Basic | $9.0M | $28.0M | $17.0M | $22.0M | $4.0M | $33.0M | $13.0M | $20.0M |
| Increase Decrease In Interest Payable Net | — | $37.0M | — | -$20.0M | -$105.0M | -$62.0M | — | -$17.0M |
| Foreign Currency Translation Adjustments | -$1.0M | $45.0M | — | $16.0M | $64.0M | -$16.0M | — | -$13.0M |
| Change in foreign currency translation | -$1.0M | $45.0M | — | $16.0M | $64.0M | -$16.0M | — | -$13.0M |
| Foreign Currency Translation Adjustments, Net of Tax | -$1.0M | $45.0M | — | $16.0M | $64.0M | -$16.0M | — | -$13.0M |
| OCI - Foreign Currency Translation Adjustment | -$1.0M | $45.0M | — | $16.0M | $64.0M | -$16.0M | — | -$13.0M |
| Foreign currency translation | -$1.0M | $45.0M | — | $16.0M | $64.0M | -$16.0M | — | -$13.0M |
| Currency Translation Adjustment, Net of Tax | -$1.0M | $45.0M | — | $16.0M | $64.0M | -$16.0M | — | -$13.0M |
| OCI Foreign Currency Translation | -$1.0M | $45.0M | — | $16.0M | $64.0M | -$16.0M | — | -$13.0M |
| Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent | — | — | — | -$5.0M | — | — | — | $11.0M |
| Currency exchange and other | — | $21.0M | — | $11.0M | $23.0M | — | — | -$7.0M |
| Income from discontinued operations, net of tax | $0.0 | $0.0 | — | $0.0 | -$14.0M | -$1.0M | — | -$7.0M |
| Other Noncash Income (Expense) | $0.0 | -$6.0M | -$28.0M | -$45.0M | -$25.0M | -$31.0M | -$10.0M | -$6.0M |
| Recognized interest income | $6.0M | $6.0M | — | $3.0M | $3.0M | $4.0M | — | $4.0M |
| Term loan by year, year 1 | $14.0M | $53.0M | — | $5.0M | $20.0M | $72.0M | — | $3.0M |
| Other | $0.0 | $0.0 | — | $0.0 | $0.0 | $0.0 | — | $3.0M |
| Other | $0.0 | $0.0 | — | $0.0 | $0.0 | $0.0 | — | $3.0M |
| Proceeds from Maturities, Prepayments and Calls of Held-to-Maturity Securities | — | — | — | $0.0 | — | — | — | $3.0M |
| Proceeds from issuance of common stock relating to employee stock plans | — | $3.0M | — | $1.0M | — | — | $8.0M | $1.0M |
| Exercises of stock options | — | $3.0M | — | $1.0M | — | — | — | $1.0M |
| Add - Incremental shares associated with contingently issuable shares (in shares) | 600K | 600K | — | 700K | 0 | 400K | — | 900K |
| Add: dilutive effect of potential common shares (in shares) | $800.0K | $700.0K | — | $900.0K | $0.0 | $500.0K | — | $900.0K |
| Number of operating segments | — | — | — | 3.00 | — | — | — | 3.00 |
| Number of reportable segments | — | — | — | 3.00 | — | — | — | 3.00 |
| Common Stock Dividends Per Share Declared | $0.6 | $0.6 | — | $0.6 | $0.6 | $0.6 | — | $0.8 |
| Common Stock Dividends Per Share | $0.6 | $0.6 | — | $0.6 | $0.6 | $0.6 | — | $0.8 |
| Dividends per share declared | $0.6 | $0.6 | — | $0.6 | $0.6 | $0.6 | — | $0.8 |
| Dividends per share declared | $0.6 | $0.6 | — | $0.6 | $0.6 | $0.6 | — | $0.8 |
| Common Stock Dividends Per Share Declared | $0.6 | $0.6 | — | $0.6 | $0.6 | $0.6 | — | $0.8 |
| Dividends declared (in dollars per share) | $0.6 | $0.6 | — | $0.6 | $0.6 | $0.6 | — | $0.8 |
| Common Stock Dividends Per Share Declared | $0.6 | $0.6 | — | $0.6 | $0.6 | $0.6 | — | $0.8 |
| Common Stock Dividends Per Share Declared | $0.6 | $0.6 | — | $0.6 | $0.6 | $0.6 | — | $0.8 |
| % of total class of receivables | 0.3% | 0.4% | — | 0.4% | 0.5% | 0.5% | — | 0.5% |
| Discount For Preferred Stock Redeemed | $0.0 | $0.0 | $0.0 | — | — | $0.0 | — | $0.0 |
| Add - Incremental shares under stock-based compensation plans (in shares) | 200K | 100K | — | 200K | 0 | 100K | — | 0 |
| Other | $0.0 | $0.0 | — | $0.0 | $0.0 | $0.0 | — | $0.0 |
| Preferred Stock Redemption Discount | $0.0 | $0.0 | — | $0.0 | $6.0M | — | — | — |
