Preferred Stock (Details) $ in Millions		3 Months Ended		9 Months Ended		12 Months Ended
	Jul. 23, 2024 USD ($)	Sep. 30, 2024 USD ($) shares	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) vote shares	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($) shares
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		4,742,300		4,742,300		4,776,800
Preferred stock, shares issued and outstanding | shares		4,680,752		4,680,752		4,714,427
Preferred stock, liquidation preference, value | $		$ 19,376		$ 19,376		$ 20,216
Preferred stock, carrying value | $		18,608		$ 18,608		$ 19,448
Detail of Preferred Stock [Abstract]
Voting rights				If issued, preference shares would be limited to one vote per share
Preferred stock issued | $		$ 1,997	$ 1,722	$ 1,997	$ 1,722
Number of additional common stock shares per preferred share | shares		16.5916		16.5916		16.5916
Preferred stock, no voting rights [Member]
Detail of Preferred Stock [Abstract]
Preferred shares authorized | shares		20,000,000		20,000,000
Preferred stock, par or stated value | $		$ 0		$ 0
Preferred stock, voting rights [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares issued and outstanding | shares		0		0
Detail of Preferred Stock [Abstract]
Preferred shares authorized | shares		4,000,000		4,000,000
Preferred stock, par or stated value | $		$ 0		$ 0
Number of votes per share | vote				1
Dividend Equalization Preferred Shares (DEP) [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		97,000		97,000		97,000
Preferred stock, shares issued and outstanding | shares		96,546		96,546		96,546
Preferred stock, liquidation preference, value | $		$ 0		$ 0		$ 0
Preferred stock, carrying value | $		$ 0		$ 0		$ 0
Series L - 7.50% Non-Cumulative Perpetual Convertible Class A Preferred Stock [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		4,025,000		4,025,000		4,025,000
Preferred stock, shares issued and outstanding | shares		3,967,906		3,967,906		3,967,981
Preferred stock, liquidation preference, value | $		$ 3,968		$ 3,968		$ 3,968
Preferred stock, carrying value | $		$ 3,200		$ 3,200		$ 3,200
Preferred stock, dividend rate (percent)				7.50%		7.50%
Detail of Preferred Stock [Abstract]
Number of common stock shares per preferred share | shares		6.3814		6.3814		6.3814
Dividends, preferred stock | $				$ 74	$ 74
Series R - 6.625% Fixed-to-Floating Non-Cumulative Perpetual Class A Preferred Stock [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		0		0		34,500
Preferred stock, shares issued and outstanding | shares		0		0		33,600
Preferred stock, liquidation preference, value | $		$ 0		$ 0		$ 840
Preferred stock, carrying value | $		$ 0		$ 0		$ 840
Preferred stock, dividend rate (percent)				6.625%		6.625%
Series S - 5.900% Fixed-to-Floating Non-Cumulative Perpetual Class A Preferred Stock [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		0		0		80,000
Preferred stock, shares issued and outstanding | shares		0		0		80,000
Preferred stock, liquidation preference, value | $		$ 0		$ 0		$ 2,000
Preferred stock, carrying value | $		$ 0		$ 0		$ 2,000
Preferred stock, dividend rate (percent)				5.90%		5.90%
Series U - 5.875% Fixed-to-Floating Non-Cumulative Perpetual Class A Preferred Stock [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		80,000		80,000		80,000
Preferred stock, shares issued and outstanding | shares		80,000		80,000		80,000
Preferred stock, liquidation preference, value | $		$ 2,000		$ 2,000		$ 2,000
Preferred stock, carrying value | $		$ 2,000		$ 2,000		$ 2,000
Preferred stock, dividend rate (percent)				5.875%		5.875%
Series Y - 5.625% Non-Cumulative Perpetual Class A Preferred Stock [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		27,600		27,600		27,600
Preferred stock, shares issued and outstanding | shares		27,600		27,600		27,600
Preferred stock, liquidation preference, value | $		$ 690		$ 690		$ 690
Preferred stock, carrying value | $		$ 690		$ 690		$ 690
Preferred stock, dividend rate (percent)				5.625%		5.625%
Series Z - 4.75% Non-Cumulative Perpetual Class A Preferred Stock [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		80,500		80,500		80,500
Preferred stock, shares issued and outstanding | shares		80,500		80,500		80,500
Preferred stock, liquidation preference, value | $		$ 2,013		$ 2,013		$ 2,013
Preferred stock, carrying value | $		$ 2,013		$ 2,013		$ 2,013
Preferred stock, dividend rate (percent)				4.75%		4.75%
Series AA - 4.70% Non-Cumulative Perpetual Class A Preferred Stock [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		46,800		46,800		46,800
Preferred stock, shares issued and outstanding | shares		46,800		46,800		46,800
Preferred stock, liquidation preference, value | $		$ 1,170		$ 1,170		$ 1,170
Preferred stock, carrying value | $		$ 1,170		$ 1,170		$ 1,170
Preferred stock, dividend rate (percent)				4.70%		4.70%
Series BB - 3.90% Fixed-Reset Non-Cumulative Perpetual Class A Preferred Stock [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		140,400		140,400		140,400
Preferred stock, shares issued and outstanding | shares		140,400		140,400		140,400
Preferred stock, liquidation preference, value | $		$ 3,510		$ 3,510		$ 3,510
Preferred stock, carrying value | $		$ 3,510		$ 3,510		$ 3,510
Preferred stock, dividend rate (percent)				3.90%		3.90%
Series CC - 4.375% Non-Cumulative Perpetual Class A Preferred Stock [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		46,000		46,000		46,000
Preferred stock, shares issued and outstanding | shares		42,000		42,000		42,000
Preferred stock, liquidation preference, value | $		$ 1,050		$ 1,050		$ 1,050
Preferred stock, carrying value | $		$ 1,050		$ 1,050		$ 1,050
Preferred stock, dividend rate (percent)				4.375%		4.375%
Series DD - 4.25% Non-Cumulative Perpetual Class A Preferred Stock [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		50,000		50,000		50,000
Preferred stock, shares issued and outstanding | shares		50,000		50,000		50,000
Preferred stock, liquidation preference, value | $		$ 1,250		$ 1,250		$ 1,250
Preferred stock, carrying value | $		$ 1,250		$ 1,250		$ 1,250
Preferred stock, dividend rate (percent)				4.25%		4.25%
Series EE - 7.625% Non-Cumulative Perpetual Class A Preferred Stock [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		69,000		69,000		69,000
Preferred stock, shares issued and outstanding | shares		69,000		69,000		69,000
Preferred stock, liquidation preference, value | $		$ 1,725		$ 1,725		$ 1,725
Preferred stock, carrying value | $		$ 1,725		$ 1,725		$ 1,725
Preferred stock, dividend rate (percent)				7.625%		7.625%
Series FF - 6.85% Fixed Non-Cumulative Perpetual Class A Preferred Stock [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]
Preferred stock, shares authorized and designated | shares		80,000		80,000		0
Preferred stock, shares issued and outstanding | shares		80,000		80,000		0
Preferred stock, liquidation preference, value | $		$ 2,000		$ 2,000		$ 0
Preferred stock, carrying value | $		$ 2,000		$ 2,000		$ 0
Preferred stock, dividend rate (percent)				6.85%
Detail of Preferred Stock [Abstract]
Preferred stock issued | $	$ 2,000