CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Millions		Total	Cumulative Effect, Period of Adoption, Adjustment		Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment		Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effects of accounting standards adoption		$ 52,582	$ 48	[1]	$ 0	$ 7	$ 34,725	$ 57,184	$ 48	[1]	$ (9,916)	$ (29,418)
Beginning balance (shares) at Dec. 31, 2022					4,975,000	690,334,422
Beginning balance at Dec. 31, 2022		52,582	48	[1]	$ 0	$ 7	34,725	57,184	48	[1]	(9,916)	(29,418)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)		2,336						960			1,376
Dividends—common stock (shares)	[2]					26,635
Dividends—common stock	[2]	(234)				$ 0	3	(237)
Dividends—preferred stock		(57)						(57)
Purchases of treasury stock		(246)										(246)
Issuances of common stock and restricted stock, net of forfeitures (shares)						2,972,149
Issuances of common stock and restricted stock, net of forfeitures		76				$ 0	76
Compensation expense for restricted stock units		148					148
Ending balance (shares) at Mar. 31, 2023					4,975,000	693,333,206
Ending balance at Mar. 31, 2023		54,653			$ 0	$ 7	34,952	57,898			(8,540)	(29,664)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effects of accounting standards adoption		54,653			0	7	34,952	57,898			(8,540)	(29,664)
Cumulative effects of accounting standards adoption		58,089	(25)	[3]	$ 0	$ 7	35,541	60,945	(25)	[3]	(8,268)	(30,136)
Beginning balance (shares) at Dec. 31, 2023					4,975,000	696,242,668
Beginning balance at Dec. 31, 2023		58,089	$ (25)	[3]	$ 0	$ 7	35,541	60,945	$ (25)	[3]	(8,268)	(30,136)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)		14						1,280			(1,266)
Dividends—common stock (shares)	[2]					24,969
Dividends—common stock	[2]	(235)				$ 0	3	(238)
Dividends—preferred stock		(57)						(57)
Purchases of treasury stock		(249)										(249)
Issuances of common stock and restricted stock, net of forfeitures (shares)						3,470,983
Issuances of common stock and restricted stock, net of forfeitures		80				$ 0	80
Exercises of stock options (shares)						15,000
Exercises of stock options		1				$ 0	1
Compensation expense for restricted stock units		183					183
Ending balance (shares) at Mar. 31, 2024					4,975,000	699,753,620
Ending balance at Mar. 31, 2024		57,801			$ 0	$ 7	35,808	61,905			(9,534)	(30,385)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effects of accounting standards adoption		$ 57,801			$ 0	$ 7	$ 35,808	$ 61,905			$ (9,534)	$ (30,385)

[1] Impact from the adoption of ASU 2022-02, Financial Instruments - Credit Losses (Topic 326): Troubled Debt Restructurings (“TDR”) and Vintage Disclosures as of January 1, 2023.

[2] We declared dividends per share on our common stock of $0.60 in both the first quarters of 2024 and 2023.

[3] Impact from the adoption of Accounting Standards Update (“ASU”) 2023-02, Investments - Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Tax Credit Structures Using the Proportional Amortization Method as of January 1, 2024.