Parent Company Only Condensed Financial Information - Condensed Statements of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Adjustments to reconcile net income to net cash used for operating activities:
Gains on equity warrant assets, net	$ (560)	$ (237)	$ (138)
Gains on investment securities, net	(761)	(421)	(135)
Amortization of share-based compensation	136	84	67
Other, net	(280)	(289)	(75)
Net cash provided by operating activities	1,812	1,446	1,164
Cash flows from investing activities:
Net decrease (increase) in loans	(13,726)	(11,927)	(4,775)
Business acquisitions	(1,081)	27	102
Net cash used for investing activities	(90,336)	(31,206)	(9,372)
Cash flows from financing activities:
Principal payments of long-term debt	0	0	(359)
Proceeds from issuance of common stock, ESPP and ESOP	2,374	31	25
Net proceeds from the issuance of preferred stock	3,306	0	340
Payment of preferred stock dividends	(63)	(17)	0
Common stock repurchase	0	(60)	(352)
Net cash provided by financing activities	85,468	40,653	11,418
Net (decrease) increase in cash and cash equivalents	(3,056)	10,893	3,210
Cash and cash equivalents at beginning of period	17,675	6,782	3,572
Cash and cash equivalents at end of period	14,619	17,675	6,782
Parent Company
Condensed Cash Flow Statements, Captions [Line Items]
Net income before preferred stock dividend	1,833	1,208	1,137
Adjustments to reconcile net income to net cash used for operating activities:
Gains on equity warrant assets, net	(554)	(227)	(138)
Gains on investment securities, net	(197)	(158)	(45)
Gains on derivatives, net	0	(30)	0
Distributions of earnings from investment securities	60	65	50
Net income of subsidiaries	(264)	(211)	(776)
Cash dividends from bank subsidiary	0	50	733
Amortization of share-based compensation	136	84	67
(Increase) decrease in other assets	(40)	17	27
Increase in other liabilities	58	99	21
Other, net	2	14	8
Net cash provided by operating activities	(271)	75	766
Cash flows from investing activities:
Net decrease in investment securities from purchases, sales and maturities	533	123	129
Net decrease (increase) in loans	0	15	(15)
Net cash used for investing activities	(5,329)	(654)	(172)
Cash flows from financing activities:
Principal payments of long-term debt	0	0	(358)
Proceeds from issuance long-term debt	1,636	495	0
Proceeds from issuance of common stock, ESPP and ESOP	2,374	31	25
Net proceeds from the issuance of preferred stock	3,306	0	340
Payment of preferred stock dividends		(17)	0
Common stock repurchase	0	(60)	(353)
Net cash provided by financing activities	7,253	449	(346)
Net (decrease) increase in cash and cash equivalents	1,653	(130)	248
Cash and cash equivalents at beginning of period	671	801	553
Cash and cash equivalents at end of period	2,324	671	801
Bank Subsidiary | Parent Company
Adjustments to reconcile net income to net cash used for operating activities:
Net income of subsidiaries	(1,294)	(826)	(1,037)
Cash flows from investing activities:
Increase (decrease) in investment in subsidiaries	(1,240)	(69)	(43)
Capital Infusion In Bank Subsidiary	(5,750)	(700)	0
Nonbank Subsidiaries | Parent Company
Adjustments to reconcile net income to net cash used for operating activities:
Net income of subsidiaries	(275)	(221)	(57)
Cash flows from investing activities:
Increase (decrease) in investment in subsidiaries	47	4	23
Business acquisitions	$ (1,081)	$ 27	$ 266