v3.20.4
Revenue Recognition (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Corporate Bank [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax $ 354 $ 295 $ 286
Corporate Bank [Member] | Service charges on deposit accounts      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 152 154 145
Corporate Bank [Member] | Card and ATM fees      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 43 54 52
Corporate Bank [Member] | Investment management and trust fee income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Corporate Bank [Member] | Capital markets income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 126 69 76
Corporate Bank [Member] | Mortgage income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Corporate Bank [Member] | Investment Services Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Corporate Bank [Member] | Commercial Credit Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Corporate Bank [Member] | Bank-owned life insurance [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Corporate Bank [Member] | Securities gains, net [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Corporate Bank [Member] | Market value adjustments on employee benefit assets - defined benefit [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax   0 0
Corporate Bank [Member] | Market value adjustments on employee benefit assets - other [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Corporate Bank [Member] | Insurance commissions and fees [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax     0
Corporate Bank [Member] | Other miscellaneous income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 33 18 13
Consumer Bank [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 893 1,045 1,000
Consumer Bank [Member] | Service charges on deposit accounts      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 459 565 554
Consumer Bank [Member] | Card and ATM fees      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 385 422 404
Consumer Bank [Member] | Investment management and trust fee income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Consumer Bank [Member] | Capital markets income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Consumer Bank [Member] | Mortgage income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Consumer Bank [Member] | Investment Services Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Consumer Bank [Member] | Commercial Credit Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Consumer Bank [Member] | Bank-owned life insurance [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Consumer Bank [Member] | Securities gains, net [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Consumer Bank [Member] | Market value adjustments on employee benefit assets - defined benefit [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax   0 0
Consumer Bank [Member] | Market value adjustments on employee benefit assets - other [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Consumer Bank [Member] | Insurance commissions and fees [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax     0
Consumer Bank [Member] | Other miscellaneous income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 49 58 42
Wealth Management [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 343 331 314
Wealth Management [Member] | Service charges on deposit accounts      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 3 3 3
Wealth Management [Member] | Card and ATM fees      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 1 1
Wealth Management [Member] | Investment management and trust fee income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 253 243 235
Wealth Management [Member] | Capital markets income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Wealth Management [Member] | Mortgage income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Wealth Management [Member] | Investment Services Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 84 79 71
Wealth Management [Member] | Commercial Credit Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Wealth Management [Member] | Bank-owned life insurance [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Wealth Management [Member] | Securities gains, net [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Wealth Management [Member] | Market value adjustments on employee benefit assets - defined benefit [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax   0 0
Wealth Management [Member] | Market value adjustments on employee benefit assets - other [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Wealth Management [Member] | Insurance commissions and fees [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax     1
Wealth Management [Member] | Other miscellaneous income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 3 5 3
Other Segment Revenue [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 3 (2) 1
Other Segment Revenue [Member] | Service charges on deposit accounts      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 2 0 0
Other Segment Revenue [Member] | Card and ATM fees      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax (1) 0 (1)
Other Segment Revenue [Member] | Investment management and trust fee income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Other Segment Revenue [Member] | Capital markets income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Other Segment Revenue [Member] | Mortgage income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Other Segment Revenue [Member] | Investment Services Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Other Segment Revenue [Member] | Commercial Credit Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Other Segment Revenue [Member] | Bank-owned life insurance [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Other Segment Revenue [Member] | Securities gains, net [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Other Segment Revenue [Member] | Market value adjustments on employee benefit assets - defined benefit [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax   0 0
Other Segment Revenue [Member] | Market value adjustments on employee benefit assets - other [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Other Segment Revenue [Member] | Insurance commissions and fees [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax     3
Other Segment Revenue [Member] | Other miscellaneous income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 2 (2) (1)
Other Revenue - Not Impacted [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1] 800 447 418
Other Revenue - Not Impacted [Member] | Service charges on deposit accounts      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1] 5 7 8
Other Revenue - Not Impacted [Member] | Card and ATM fees      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1] 11 (22) (18)
Other Revenue - Not Impacted [Member] | Investment management and trust fee income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1] 0 0 0
Other Revenue - Not Impacted [Member] | Capital markets income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1] 149 109 126
Other Revenue - Not Impacted [Member] | Mortgage income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1] 333 163 137
Other Revenue - Not Impacted [Member] | Investment Services Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1] 0 0 0
Other Revenue - Not Impacted [Member] | Commercial Credit Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1] 77 73 71
Other Revenue - Not Impacted [Member] | Bank-owned life insurance [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1] 95 78 65
Other Revenue - Not Impacted [Member] | Securities gains, net [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1] 4 (28) 1
Other Revenue - Not Impacted [Member] | Market value adjustments on employee benefit assets - defined benefit [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1]   5 (6)
Other Revenue - Not Impacted [Member] | Market value adjustments on employee benefit assets - other [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1] 12 11 (5)
Other Revenue - Not Impacted [Member] | Insurance commissions and fees [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1]     0
Other Revenue - Not Impacted [Member] | Valuation Gain on Equity Investments [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [2] 50    
Other Revenue - Not Impacted [Member] | Other miscellaneous income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1] 64 51 39
Continuing Operations [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 2,393 2,116 2,019
Continuing Operations [Member] | Service charges on deposit accounts      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 621 729 710
Continuing Operations [Member] | Card and ATM fees      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 438 455 438
Continuing Operations [Member] | Investment management and trust fee income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 253 243 235
Continuing Operations [Member] | Capital markets income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 275 178 202
Continuing Operations [Member] | Mortgage income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 333 163 137
Continuing Operations [Member] | Investment Services Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 84 79 71
Continuing Operations [Member] | Commercial Credit Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 77 73 71
Continuing Operations [Member] | Bank-owned life insurance [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 95 78 65
Continuing Operations [Member] | Securities gains, net [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 4 (28) 1
Continuing Operations [Member] | Market value adjustments on employee benefit assets - defined benefit [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax   5 (6)
Continuing Operations [Member] | Market value adjustments on employee benefit assets - other [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 12 11 (5)
Continuing Operations [Member] | Insurance commissions and fees [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax     4
Continuing Operations [Member] | Valuation Gain on Equity Investments [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [2] 50    
Continuing Operations [Member] | Other miscellaneous income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 151 130 96
Discontinued Operations [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 349
Discontinued Operations [Member] | Service charges on deposit accounts      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Discontinued Operations [Member] | Card and ATM fees      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Discontinued Operations [Member] | Investment management and trust fee income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Discontinued Operations [Member] | Capital markets income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Discontinued Operations [Member] | Mortgage income      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Discontinued Operations [Member] | Investment Services Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Discontinued Operations [Member] | Commercial Credit Fee Income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Discontinued Operations [Member] | Bank-owned life insurance [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Discontinued Operations [Member] | Securities gains, net [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 (1)
Discontinued Operations [Member] | Market value adjustments on employee benefit assets - defined benefit [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax   0 0
Discontinued Operations [Member] | Market value adjustments on employee benefit assets - other [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax 0 0 0
Discontinued Operations [Member] | Insurance commissions and fees [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax     69
Discontinued Operations [Member] | Gain on sale of business [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [1]     281
Discontinued Operations [Member] | Valuation Gain on Equity Investments [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax [2] 0    
Discontinued Operations [Member] | Other miscellaneous income [Member]      
Disaggregation of Revenue [Line Items]      
RevenueFromContractWithCustomerExcludingAssessedTax $ 0 $ 0 $ 0
[1] (2)This revenue is not impacted by the accounting guidance adopted in 2018 and continues to be recognized when earned in accordance with the Company's prior revenue recognition policy.
[2] In the third quarter of 2020, the equity investee executed an initial public offering. The Company was subject to a conventional post-issuance 180 day lock-up period, which prevented the sale of its position until January 2021. The Company sold its position in January 2021 and recognized an immaterial gain.