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	Treasury Stock, at Cost	Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2022			2,000,000	492,000,000
Beginning balance at Dec. 31, 2022	$ 23,690	$ (26)	$ 2,014	$ 6	$ 22,142	$ 9,159	$ (26)	$ (5,071)	$ (4,560)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared - common stock	(609)					(609)
Dividends declared - preferred stock	$ (87)					(87)
Treasury stock purchased (in shares)	(28,472,450)			(29,000,000)
Treasury stock purchased	$ (906)							(906)
Share repurchase excise tax	(9)							(9)
Share-based compensation plans (in shares)				3,000,000
Share-based compensation plans	68				68
Employee stock purchase plan	21				21
Total comprehensive income (loss):
Net income	1,419					1,419
Other comprehensive income (loss)	(683)								(683)
Total comprehensive income (loss)	736					1,419			(683)
Ending balance (in shares) at Sep. 30, 2023			2,000,000	466,000,000
Ending balance at Sep. 30, 2023	22,878		$ 2,014	$ 6	22,231	9,856		(5,986)	(5,243)
Beginning balance (in shares) at Jun. 30, 2023			2,000,000	475,000,000
Beginning balance at Jun. 30, 2023	23,585		$ 2,014	$ 6	22,207	9,655		(5,734)	(4,563)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared - common stock	(199)					(199)
Dividends declared - preferred stock	(30)					(30)
Treasury stock purchased (in shares)				(9,000,000)
Treasury stock purchased	(250)							(250)
Share repurchase excise tax	(2)							(2)
Share-based compensation plans (in shares)				0
Share-based compensation plans	17				17
Employee stock purchase plan	7				7
Total comprehensive income (loss):
Net income	430					430
Other comprehensive income (loss)	(680)								(680)
Total comprehensive income (loss)	(250)					430			(680)
Ending balance (in shares) at Sep. 30, 2023			2,000,000	466,000,000
Ending balance at Sep. 30, 2023	22,878		$ 2,014	$ 6	22,231	9,856		(5,986)	(5,243)
Beginning balance (in shares) at Dec. 31, 2023			2,000,000	466,000,000
Beginning balance at Dec. 31, 2023	24,342		$ 2,014	$ 6	22,250	9,816		(5,986)	(3,758)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared - common stock	(581)					(581)
Dividends declared - preferred stock	(103)					(103)
Preferred stock issued	391		391
Preferred stock redemption	$ (300)		$ (293)			(7)
Treasury stock purchased (in shares)	(23,006,560)			(23,000,000)
Treasury stock purchased	$ (825)							(825)
Share repurchase excise tax	(9)							(9)
Share-based compensation plans (in shares)				2,000,000
Share-based compensation plans	57				57
Employee stock purchase plan	20				20
Total comprehensive income (loss):
Net income	1,108					1,108
Other comprehensive income (loss)	832								832
Total comprehensive income (loss)	1,940					1,108			832
Ending balance (in shares) at Sep. 30, 2024			2,000,000	445,000,000
Ending balance at Sep. 30, 2024	24,932		$ 2,112	$ 6	22,327	10,233		(6,820)	(2,926)
Beginning balance (in shares) at Jun. 30, 2024			2,000,000	453,000,000
Beginning balance at Jun. 30, 2024	23,869		$ 2,112	$ 6	22,299	10,079		(6,492)	(4,135)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared - common stock	(190)					(190)
Dividends declared - preferred stock	(38)					(38)
Treasury stock purchased (in shares)				(8,000,000)
Treasury stock purchased	(325)							(325)
Share repurchase excise tax	(3)							(3)
Share-based compensation plans (in shares)				0
Share-based compensation plans	21				21
Employee stock purchase plan	7				7
Total comprehensive income (loss):
Net income	382					382
Other comprehensive income (loss)	1,209								1,209
Total comprehensive income (loss)	1,591					382			1,209
Ending balance (in shares) at Sep. 30, 2024			2,000,000	445,000,000
Ending balance at Sep. 30, 2024	$ 24,932		$ 2,112	$ 6	$ 22,327	$ 10,233		$ (6,820)	$ (2,926)