Parent Company - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Condensed Financial Statements, Captions [Line Items]
Other comprehensive income/(loss)	$ (942.0)	$ (634.0)	$ 50.0
Cash payments for interest, net of capitalized interest	19,022.0	5,521.0	9,091.0
Cash payments for income taxes, net	4,555.0	6,195.0	2,754.0
Group Inc.
Condensed Financial Statements, Captions [Line Items]
Cash dividends from bank subsidiaries	97.0	16,990.0	38.0
Cash dividends from nonbank subsidiaries	6,140.0	15,140.0	11,320.0
Other revenues from related parties	(3,340.0)	(1,010.0)	2,620.0
Interest income from related parties	7,470.0	3,390.0	3,680.0
Interest expense from related parties	3,800.0	1,240.0	1,730.0
Other expenses from related parties	116.0	113.0	100.0
Other comprehensive income/(loss)	(942.0)	(634.0)	50.0
Derivative contracts with subsidiaries, trading assets	2,170.0	1,380.0
Derivative contracts with subsidiaries, trading liabilities	2,540.0	1,120.0
Unsecured long-term borrowings with subsidiaries by maturity date, 2024	56,100.0
Unsecured long-term borrowings with subsidiaries by maturity date, 2025	534.0
Unsecured long-term borrowings with subsidiaries by maturity date, 2026	62.0
Unsecured long-term borrowings with subsidiaries by maturity date, 2027	103.0
Unsecured long-term borrowings with subsidiaries by maturity date, 2028	770.0
Cash payments for interest, net of capitalized interest	8,540.0	4,720.0	5,920.0
Cash payments for interest, to subsidiaries	3,550.0	1,330.0	1,900.0
Cash payments for income taxes, net	2,590.0	3,740.0	1,370.0
Issuance of common stock in connection with acquisition	$ 1,750.0
Loans exchanged for additional equity interest in subsidiaries		$ 948.0
Trust Preferred securities and common beneficial interests exchanged			11.2
Junior subordinated debt			$ 12.5