Common and Preferred Stock (Details) - USD ($)		1 Months Ended	3 Months Ended				6 Months Ended
	Dec. 01, 2015	Jul. 31, 2018	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Nov. 06, 2014
Equity [Abstract]
Increase in share repurchase authorized amount	$ 300,000,000.0
Stock repurchase program, authorized amount										$ 400,000,000.0
Purchase of common stock (in shares)			19,143	369,810	147,490	0	389,000	147,000
Repurchase of shares of common stock			$ 2,962,000	$ 51,706,000	$ 20,494,000		$ 54,700,000	$ 20,500,000
Purchase of common stock		$ 1,000,000.0					54,668,000	$ 19,499,000
Remaining authorized repurchase amount			$ 322,300,000				$ 322,300,000
Common stock, authorized (in shares)			150,000,000				150,000,000		150,000,000
Common stock, par value (in dollars per share)			$ 0.01				$ 0.01		$ 0.01
Preferred stock, authorized (in shares)			5,000,000				5,000,000		5,000,000
Preferred stock, par value (in dollars per share)			$ 0.01				$ 0.01		$ 0.01
Preferred stock, shares outstanding (in shares)			0				0		0