Shareholders' Equity - Schedule of Dividends Declared (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Dividends Payable [Line Items]
Preferred stock cash dividend	$ 25	$ 44
Series C Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 0	$ 1,313
Preferred stock cash dividend	$ 0	$ 6
Series C Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 0	$ 0.33
Series D Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 1,475	$ 1,475
Preferred stock cash dividend	$ 11	$ 11
Series D Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 0.37	$ 0.37
Series F Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 953	$ 2,625
Preferred stock cash dividend	$ 7	$ 20
Series F Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 9.53	$ 26.25
Series G Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 1,338	$ 1,338,000,000
Preferred stock cash dividend	$ 7	$ 7
Series G Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 0.33	$ 0.33
Series H Preferred Stock
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 0	$ 0
Preferred stock cash dividend	$ 0	$ 0
Series H Preferred Stock, Depository Share
Dividends Payable [Line Items]
Preferred dividends declared (USD per share)	$ 0	$ 0