Stockholders' Equity - Additional Information (Details) - USD ($)			12 Months Ended
	Jan. 23, 2019	May 05, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 22, 2020
Class of Stock [Line Items]
Common stock, shares authorized (in shares)			1,125,000,000	1,125,000,000
Common stock, par value (in dollars per share)			$ 0.2	$ 0.2
Common stock shares outstanding (in shares)			421,000,000
Common shares unissued but encumbered (in shares)			37,000,000
Common stock dividend per common share			$ 0.12
Common stock dividends				$ 0	$ 0
Aggregate purchase price (not to exceed)	$ 200,000,000
Common stock repurchased (in shares)	17,000,000		16,962,199	0	0
Repurchase amount	$ 167,000,000		$ 33,000,000
Subsequent Event
Class of Stock [Line Items]
Aggregate purchase price (not to exceed)						$ 600,000,000
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock shares outstanding (in shares)		3,300,000	0	0
Preferred stock dividend rate (as a percentage)		6.97%
Preferred stock dividend rate (in dollars per share)		$ 50
Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock shares outstanding (in shares)			4,000,000.0	4,000,000
Preferred stock liquidation preference (in dollars per share)			$ 100
Series B Preferred Stock | Three Month LIBOR
Class of Stock [Line Items]
Preferred stock dividend rate (as a percentage)			1.70%
Common Stock
Class of Stock [Line Items]
Share price (in dollars per share)			$ 8.91