Common, Preferred and Treasury Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 30, 2020	Sep. 17, 2019	Aug. 26, 2019	Jun. 05, 2014	Dec. 09, 2013	May 16, 2013	Dec. 31, 2021	Dec. 31, 2020	Jun. 30, 2019
Class of Stock [Line Items]
Preferred stock, liquidation preference per share (in dollars per share)							$ 25,000	$ 25,000
Number of shares authorized to be repurchased									100,000,000
Preferred stock, Series L
Class of Stock [Line Items]
Issuance of preferred shares (in shares)	350,000
Preferred stock, issued (in shares)	14,000
Preferred stock, dividend rate (as a percent)	4.50%
Issuance of preferred shares	$ 346
Preferred stock, liquidation preference per share (in dollars per share)	$ 25,000
Preferred stock, redemption percentage	100.00%
Preferred stock, Series L | U.S. Treasury Rate
Class of Stock [Line Items]
Preferred stock, basis spread on variable rate (as a percent)	4.215%
Preferred Stock Series K
Class of Stock [Line Items]
Issuance of preferred shares (in shares)		10,000,000
Preferred stock, issued (in shares)		10,000
Preferred stock, dividend rate (as a percent)		4.95%
Issuance of preferred shares		$ 242
Preferred stock, liquidation preference per share (in dollars per share)		$ 25,000
Preferred Stock Class B, Series A
Class of Stock [Line Items]
Issuance of preferred shares (in shares)			200,000
Preferred stock, dividend rate (as a percent)			6.00%
Preferred stock, liquidation preference per share (in dollars per share)			$ 1,000				$ 1,000	$ 1,000
Preferred stock, Series J
Class of Stock [Line Items]
Issuance of preferred shares (in shares)				300,000
Preferred stock, issued (in shares)				12,000
Preferred stock, dividend rate (as a percent)				4.90%
Issuance of preferred shares				$ 297
Preferred stock, liquidation preference per share (in dollars per share)				$ 25,000
Preferred stock, Series J | LIBOR
Class of Stock [Line Items]
Preferred stock, basis spread on variable rate (as a percent)				3.129%
Preferred stock, Series I
Class of Stock [Line Items]
Issuance of preferred shares (in shares)					18,000,000
Preferred stock, issued (in shares)					18,000
Preferred stock, dividend rate (as a percent)					6.625%
Issuance of preferred shares					$ 441
Preferred stock, liquidation preference per share (in dollars per share)					$ 25,000
Preferred stock, Series I | LIBOR
Class of Stock [Line Items]
Preferred stock, basis spread on variable rate (as a percent)					3.71%
Preferred stock, Series H
Class of Stock [Line Items]
Issuance of preferred shares (in shares)						600,000
Preferred stock, issued (in shares)						24,000
Preferred stock, dividend rate (as a percent)						5.10%
Issuance of preferred shares						$ 593
Preferred stock, liquidation preference per share (in dollars per share)						$ 25,000
Preferred stock, Series H | LIBOR
Class of Stock [Line Items]
Preferred stock, basis spread on variable rate (as a percent)						3.033%