Shareholders' Equity - Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended				3 Months Ended
	Sep. 30, 2018	Apr. 30, 2016	May 31, 2015	Feb. 28, 2014	Mar. 31, 2023	Mar. 31, 2022
Class of Stock [Line Items]
Preferred stock cash dividend					$ 23	$ 20
Series D Preferred Stock
Class of Stock [Line Items]
Preferred dividends declared (USD per share)					$ 1,475	$ 1,475
Preferred stock cash dividend					$ 11	$ 11
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
Series F Preferred Stock
Class of Stock [Line Items]
Preferred dividends declared (USD per share)					$ 2,092	$ 950
Preferred stock cash dividend					$ 5	$ 2
Ownership Interest Per Depositary Share			1.00%
Series F Preferred Stock, Depository Share
Class of Stock [Line Items]
Preferred dividends declared (USD per share)					$ 20.92	$ 9.50
Series G Preferred Stock
Class of Stock [Line Items]
Preferred dividends declared (USD per share)					$ 1,338	$ 1,338
Preferred stock cash dividend					$ 7	$ 7
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
Series H Preferred Stock
Class of Stock [Line Items]
Ownership Interest Per Depositary Share	1.00%