Shareholders' Equity (Details) - USD ($)		6 Months Ended
	Mar. 05, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Common stock, shares issued	10,000,000
Preferred stock, shares authorized		50,000,000		50,000,000
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01		$ 0.01
Preferred Stock, shares issued		10,000,000		0
Preferred Stock, shares outstanding		10,000,000		0
Preferred Stock, Liquidation Preference, Value		$ 250,000,000.0	$ 250,000
Preferred Stock, rate (as a percent)	6.15%
Preferred Stock, Liquidation Preference, per share	$ 25.00
Preferred Stock, state amount	$ 25.00
Dividend Payable Beginning on 15 June 2019
Class of Stock [Line Items]
Preferred Stock, rate (as a percent)	6.15%
Preferred Stock, term	5 years
Dividend Payable Beginning on 15 March 2024
Class of Stock [Line Items]
Preferred Stock, redemption price (in dollars per share)		$ 25.00
Dividend Payable Beginning on 15 March 2024 | Three-Month LIBOR
Class of Stock [Line Items]
Preferred Stock, spread	3.65%
Class A Common Stock
Class of Stock [Line Items]
Common Stock, authorized shares		500,000,000		500,000,000
Common Stock, par value (in dollars per share)		$ 0.01		$ 0.01
Common stock, shares issued		111,666,126		110,949,850
Common stock, shares outstanding		111,666,126		110,949,850
Class B Non-Voting Common Stock
Class of Stock [Line Items]
Common Stock, authorized shares		10,000,000		10,000,000
Common Stock, par value (in dollars per share)		$ 0.01		$ 0.01
Common stock, shares issued		0		0
Common stock, shares outstanding		0		0
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized		50,000,000		50,000,000
Preferred stock, par value (in dollars per share)		$ 0.01		$ 0.01
Preferred Stock, shares issued		10,000,000		0
Preferred Stock, shares outstanding				0
Preferred Stock, rate (as a percent)		6.15%