Stockholders' Equity - Preferred Stock Outstanding (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Preferred Stock, Including Additional Paid in Capital, Net of Discount	$ 4,845	$ 4,847
Series E Preferred Stock
Class of Stock [Line Items]
Per Annum Dividend Rate	5.55%
Liquidation Preference per Share	$ 1,000
Total Shares Outstanding as of December 31, 2021	0
Preferred Stock, Including Additional Paid in Capital, Net of Discount	$ 0	988
Preferred Stock, Dividend Payment Rate, Variable	LIBOR + 380 bps
Series G Preferred Stock
Class of Stock [Line Items]
Per Annum Dividend Rate	5.20%
Liquidation Preference per Share	$ 1,000
Total Shares Outstanding as of December 31, 2021	0
Preferred Stock, Including Additional Paid in Capital, Net of Discount	$ 0	583
Series H Preferred Stock
Class of Stock [Line Items]
Per Annum Dividend Rate	6.00%
Liquidation Preference per Share	$ 1,000
Total Shares Outstanding as of December 31, 2021	0
Preferred Stock, Including Additional Paid in Capital, Net of Discount	$ 0	483
Series I Preferred Stock
Class of Stock [Line Items]
Per Annum Dividend Rate	5.00%
Liquidation Preference per Share	$ 1,000
Total Shares Outstanding as of December 31, 2021	1,500,000
Preferred Stock, Including Additional Paid in Capital, Net of Discount	$ 1,462	1,462
Series J Preferred Stock
Class of Stock [Line Items]
Per Annum Dividend Rate	4.80%
Liquidation Preference per Share	$ 1,000
Total Shares Outstanding as of December 31, 2021	1,250,000
Preferred Stock, Including Additional Paid in Capital, Net of Discount	$ 1,209	1,209
Series K Preferred Stock
Class of Stock [Line Items]
Per Annum Dividend Rate	4.625%
Liquidation Preference per Share	$ 1,000
Total Shares Outstanding as of December 31, 2021	125,000
Preferred Stock, Including Additional Paid in Capital, Net of Discount	$ 122	122
Series L Preferred Stock
Class of Stock [Line Items]
Per Annum Dividend Rate	4.375%
Liquidation Preference per Share	$ 1,000
Total Shares Outstanding as of December 31, 2021	675,000
Preferred Stock, Including Additional Paid in Capital, Net of Discount	$ 652	0
Series M Preferred Stock
Class of Stock [Line Items]
Per Annum Dividend Rate	3.95%
Liquidation Preference per Share	$ 1,000
Total Shares Outstanding as of December 31, 2021	1,000,000
Preferred Stock, Including Additional Paid in Capital, Net of Discount	$ 988	0
Preferred Stock, Dividend Payment Rate, Variable	5-Year Treasury Rate +3.157
Series N Preferred Stock
Class of Stock [Line Items]
Per Annum Dividend Rate	4.25%
Liquidation Preference per Share	$ 1,000
Total Shares Outstanding as of December 31, 2021	425,000
Preferred Stock, Including Additional Paid in Capital, Net of Discount	$ 412	$ 0