Shareholders' Equity - Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended				3 Months Ended				6 Months Ended
	Sep. 30, 2018	Apr. 30, 2016	May 31, 2015	Feb. 28, 2014	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Class of Stock [Line Items]
Preferred stock cash dividend					$ 37	$ 23	$ 35	$ 20	$ 60	$ 55
Series D Preferred Stock
Class of Stock [Line Items]
Preferred dividends declared (USD per share)					$ 1,475		$ 1,475		$ 2,950	$ 2,950
Preferred stock cash dividend					$ 11		$ 11		$ 22	$ 22
Ownership Interest Per Depositary Share				0.025%
Series D Preferred Stock, Depository Share
Class of Stock [Line Items]
Preferred dividends declared (USD per share)					$ 0.37		$ 0.37		$ 0.74	$ 0.74
Series F Preferred Stock
Class of Stock [Line Items]
Preferred dividends declared (USD per share)					$ 2,163		$ 1,130		$ 4,254	$ 2,080
Preferred stock cash dividend					$ 5		$ 3		$ 11	$ 5
Ownership Interest Per Depositary Share			1.00%
Series F Preferred Stock, Depository Share
Class of Stock [Line Items]
Preferred dividends declared (USD per share)					$ 21.63		$ 11.30		$ 42.54	$ 20.80
Series G Preferred Stock
Class of Stock [Line Items]
Preferred dividends declared (USD per share)					$ 1,338		$ 1,338		$ 2,675	$ 2,676
Preferred stock cash dividend					$ 7		$ 7		$ 13	$ 14
Ownership Interest Per Depositary Share		0.025%
Series G Preferred Stock, Depository Share
Class of Stock [Line Items]
Preferred dividends declared (USD per share)					$ 0.33		$ 0.33		$ 0.66	$ 0.66
Series H Preferred Stock
Class of Stock [Line Items]
Preferred dividends declared (USD per share)					$ 2,813		$ 2,813		$ 2,813	$ 2,813
Preferred stock cash dividend					$ 14		$ 14		$ 14	$ 14
Ownership Interest Per Depositary Share	1.00%
Series H Preferred Stock, Depository Share
Class of Stock [Line Items]
Preferred dividends declared (USD per share)					$ 28.13		$ 28.13		$ 28.13	$ 28.13