Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	$ 202,889	$ 79,129	$ 123,714
Other comprehensive income (loss):
Foreign currency translation adjustments	483	(4,191)	(3,930)
Change in fair value of interest rate swap	599	337	242
Other comprehensive income (loss)	1,082	(3,854)	(3,688)
Comprehensive income	$ 203,971	$ 75,275	$ 120,026