Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total		Common Stock	Nonvoting Common Stock	Preferred Stock	Common Stock	Common Stock Common Stock	Common Stock Nonvoting Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock, at cost	Treasury Stock, at cost Common Stock	Treasury Stock, at cost Nonvoting Common Stock	Accumulated Other Comprehensive Income (Loss)
Balance at beginning of period at Dec. 31, 2021	$ 56,261.0				$ 9,954.0		$ 20.0	$ 1.0	$ 26,741.0	$ 25,992.0	$ (5,338.0)			$ (1,109.0)
Beginning balance (in shares) at Dec. 31, 2021							1,995,000,000	79,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	5,215.0	[1]	$ 5,014.0	$ 201.0						5,215.0
Other comprehensive income (loss), net of tax	(22,043.0)													(22,043.0)
Issuance of preferred stock, net	740.0				740.0
Call of preferred stock	(400.0)				(397.0)					(3.0)
Dividends declared on preferred stock	(373.9)									(374.0)
Dividends declared on common stock	(1,179.0)									(1,179.0)
Repurchase of stock (in shares)							15,000,000	15,000,000
Repurchase of stock			(500.0)	(1,000.0)								$ (500.0)	$ (1,000.0)
Conversion of nonvoting common stock to common stock (in shares)							13,000,000	(13,000,000)
Stock option exercises and other	42.0								(68.0)		110.0
Share-based compensation	215.0								215.0
Other	64.0								87.0		(23.0)
Ending balance (in shares) at Sep. 30, 2022							2,023,000,000	51,000,000
Balance at end of period at Sep. 30, 2022	37,041.0				10,297.0		$ 20.0	$ 1.0	26,975.0	29,651.0	(6,751.0)			(23,152.0)
Balance at beginning of period at Jun. 30, 2022	44,513.0				10,694.0		$ 20.0	$ 1.0	26,918.0	28,174.0	(5,272.0)			(16,022.0)
Beginning balance (in shares) at Jun. 30, 2022							1,995,000,000	79,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,020.0		1,956.0	64.0						2,020.0
Other comprehensive income (loss), net of tax	(7,130.0)													(7,130.0)
Call of preferred stock	(400.0)				(397.0)					(3.0)
Dividends declared on preferred stock	(123.4)									(123.0)
Dividends declared on common stock	(417.0)									(417.0)
Repurchase of stock (in shares)							15,000,000	15,000,000
Repurchase of stock			(500.0)	(1,000.0)								$ (500.0)	$ (1,000.0)
Conversion of nonvoting common stock to common stock (in shares)							13,000,000	(13,000,000)
Stock option exercises and other	9.0								(12.0)		21.0
Share-based compensation	50.0								50.0
Other	19.0								19.0
Ending balance (in shares) at Sep. 30, 2022							2,023,000,000	51,000,000
Balance at end of period at Sep. 30, 2022	37,041.0				10,297.0		$ 20.0	$ 1.0	26,975.0	29,651.0	(6,751.0)			(23,152.0)
Balance at beginning of period at Dec. 31, 2022	36,608.0	[2]			9,706.0		$ 20.0	$ 1.0	27,075.0	31,066.0	(8,639.0)			(22,621.0)
Beginning balance (in shares) at Dec. 31, 2022							2,023,000,000	51,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,022.0	[1]	3,910.0	112.0						4,022.0
Other comprehensive income (loss), net of tax	1,869.0													1,869.0
Redemption and repurchase of preferred stock, inclusive of tax	(471.0)				(515.0)					44.0
Dividends declared on preferred stock	(323.9)									(324.0)
Dividends declared on common stock	(1,379.0)									(1,379.0)
Repurchase of stock (in shares)						37,000,000
Repurchase of stock	(2,869.0)					$ (2,800.0)					(2,869.0)
Stock option exercises and other	33.0								(110.0)		143.0
Share-based compensation	242.0								242.0
Other	53.0								86.0		(33.0)
Ending balance (in shares) at Sep. 30, 2023							2,023,000,000	51,000,000
Balance at end of period at Sep. 30, 2023	37,784.0	[2]			9,191.0		$ 20.0	$ 1.0	27,293.0	33,429.0	(11,398.0)			(20,752.0)
Balance at beginning of period at Jun. 30, 2023	37,147.0				9,191.0		$ 20.0	$ 1.0	27,220.0	32,865.0	(11,420.0)			(20,730.0)
Beginning balance (in shares) at Jun. 30, 2023							2,023,000,000	51,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,125.0		$ 1,094.0	$ 31.0						1,125.0
Other comprehensive income (loss), net of tax	(22.0)													(22.0)
Dividends declared on preferred stock	(103.0)									(103.0)
Dividends declared on common stock	(458.0)									(458.0)
Repurchase of stock (in shares)						0
Stock option exercises and other	9.0								(9.0)		18.0
Share-based compensation	60.0								60.0
Other	26.0								22.0		4.0
Ending balance (in shares) at Sep. 30, 2023							2,023,000,000	51,000,000
Balance at end of period at Sep. 30, 2023	$ 37,784.0	[2]			$ 9,191.0		$ 20.0	$ 1.0	$ 27,293.0	$ 33,429.0	$ (11,398.0)			$ (20,752.0)

[1] Certain prior period amounts have been reclassified to conform to the current year presentation. See Note 1 for additional information.

[2] Certain prior year amounts have been reclassified to conform to the current year presentation. See Note 1 for additional information.