Stockholders' Equity - Schedule of Stock Repurchases (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Stockholders Equity [Line Items]
Total cost	$ 48,332	$ 21,883		$ 14,220
2016 Stock Repurchase Program
Stockholders Equity [Line Items]
Shares of common stock repurchased and retired (in shares)	580		0		908	337
Average price paid per share (in dollars per share)	$ 83.34		$ 0		$ 77.33	$ 42.17
Total cost	$ 48,320		$ 0		$ 70,197	$ 14,213