Fair Value of Financial Instruments - Summary of Estimated Fair Values of Financial Instruments not Carried at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturities, fair value	$ 76,169	$ 97,227
Net loans	73,614	65,854
Time deposits	6,693	1,739
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	13,803	14,586
Held-to-maturities, fair value	91,321	98,195
Non-marketable securities not measured at net asset value	441	424
Non-marketable securities measured at net asset value	628	710
Net loans	73,614	65,854
FHLB and FRB stock	720	107
Non-maturity deposits	166,416	187,464
Time deposits	6,693	1,739
FHLB Advances	2,000
Junior subordinated debentures	91	90
Commitments to extend credit	0	0
Carrying Amount | Other short-term borrowings
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	13,565	71
Carrying Amount | 3.50% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	349	349
Carrying Amount | 3.125% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	496	496
Carrying Amount | 1.800% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	495	494
Carrying Amount | 2.100% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	497	496
Carrying Amount | 1.800% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	646	645
Carrying Amount | 4.345% Senior Fixed Rate/Floating Rate Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	348
Carrying Amount | 4.570% Senior Fixed Rate/Floating Rate Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	448
Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	13,803	14,586
Held-to-maturities, fair value	76,169	97,227
Non-marketable securities not measured at net asset value	441	424
Non-marketable securities measured at net asset value	628	710
Net loans	74,602	67,335
FHLB and FRB stock	720	107
Non-maturity deposits	166,416	187,464
Time deposits	6,479	1,728
FHLB Advances	2,000
Junior subordinated debentures	96	92
Commitments to extend credit	52	47
Estimated Fair Value | Other short-term borrowings
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	13,565	71
Estimated Fair Value | 3.50% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	337	370
Estimated Fair Value | 3.125% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	412	526
Estimated Fair Value | 1.800% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	364	474
Estimated Fair Value | 2.100% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	417	501
Estimated Fair Value | 1.800% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	570	649
Estimated Fair Value | 4.345% Senior Fixed Rate/Floating Rate Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	331
Estimated Fair Value | 4.570% Senior Fixed Rate/Floating Rate Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	397
Estimated Fair Value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	13,803	14,586
Held-to-maturities, fair value	0	0
Non-marketable securities not measured at net asset value	0	0
Net loans	0	0
FHLB and FRB stock	0	0
Non-maturity deposits	166,416	187,464
Time deposits	0	0
FHLB Advances	0
Junior subordinated debentures	0	0
Commitments to extend credit	0	0
Estimated Fair Value | Level 1 | Other short-term borrowings
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Estimated Fair Value | Level 1 | 3.50% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0	0
Estimated Fair Value | Level 1 | 3.125% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0	0
Estimated Fair Value | Level 1 | 1.800% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0	0
Estimated Fair Value | Level 1 | 2.100% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0	0
Estimated Fair Value | Level 1 | 1.800% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0	0
Estimated Fair Value | Level 1 | 4.345% Senior Fixed Rate/Floating Rate Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0
Estimated Fair Value | Level 1 | 4.570% Senior Fixed Rate/Floating Rate Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0
Estimated Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Held-to-maturities, fair value	76,169	97,227
Non-marketable securities not measured at net asset value	0	0
Net loans	0	0
FHLB and FRB stock	0	0
Non-maturity deposits	0	0
Time deposits	6,479	1,728
FHLB Advances	2,000
Junior subordinated debentures	96	92
Commitments to extend credit	0	0
Estimated Fair Value | Level 2 | Other short-term borrowings
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	13,565	71
Estimated Fair Value | Level 2 | 3.50% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	337	370
Estimated Fair Value | Level 2 | 3.125% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	412	526
Estimated Fair Value | Level 2 | 1.800% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	364	474
Estimated Fair Value | Level 2 | 2.100% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	417	501
Estimated Fair Value | Level 2 | 1.800% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	570	649
Estimated Fair Value | Level 2 | 4.345% Senior Fixed Rate/Floating Rate Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	331
Estimated Fair Value | Level 2 | 4.570% Senior Fixed Rate/Floating Rate Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	397
Estimated Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Held-to-maturities, fair value	0	0
Non-marketable securities not measured at net asset value	441	424
Net loans	74,602	67,335
FHLB and FRB stock	720	107
Non-maturity deposits	0	0
Time deposits	0	0
FHLB Advances	0
Junior subordinated debentures	0	0
Commitments to extend credit	52	47
Estimated Fair Value | Level 3 | Other short-term borrowings
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Estimated Fair Value | Level 3 | 3.50% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0	0
Estimated Fair Value | Level 3 | 3.125% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0	0
Estimated Fair Value | Level 3 | 1.800% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0	0
Estimated Fair Value | Level 3 | 2.100% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0	0
Estimated Fair Value | Level 3 | 1.800% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0	$ 0
Estimated Fair Value | Level 3 | 4.345% Senior Fixed Rate/Floating Rate Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0
Estimated Fair Value | Level 3 | 4.570% Senior Fixed Rate/Floating Rate Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	$ 0