Preferred Stock - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Preferred stock issuance	$ 145	$ 144
Carrying Amount			$ 520	$ 470
Liquidation Amount			$ 538
Call of preferred stock	100
Preferred stock, shares issued (in shares)			26,750	26,250
Noncontrolling interest			$ 295	$ 295
Retained Earnings
Class of Stock [Line Items]
Call of preferred stock	5		$ 5
Series F
Class of Stock [Line Items]
Preferred stock issuance	$ 150
Annual Dividend Rate	4.70%		4.70%
Carrying Amount	$ 145		$ 145	0
Liquidation Amount			$ 150
Series A
Class of Stock [Line Items]
Annual Dividend Rate			6.20%
Carrying Amount			$ 0	95
Liquidation Amount			0
Series A | Other Liabilities
Class of Stock [Line Items]
Liquidation Amount			$ 100
Preferred Class A
Class of Stock [Line Items]
Annual Dividend Rate			3.75%
Preferred stock, shares issued (in shares)			300,000
Preferred stock, liquidation preference per share (in dollars per share)			$ 1,000
Noncontrolling interest			$ 295	$ 295
Preferred Class A | LIBOR
Class of Stock [Line Items]
Basis spread on variable rate			0.85%