Income Taxes - Summary of Significant Components of the Income Tax Provision From Continuing Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ 1,693	$ 3,685	$ (876)
State	2,573	1,716	1,558
Foreign	15,583	8,177	9,342
Total current	19,849	13,578	10,024
Deferred:
Federal	19,893	8,427	1,854
State	1,761	(598)	(164)
Foreign	4,395	(157)	(1,221)
Total deferred	26,049	7,672	469
Income tax expense	$ 45,898	$ 21,250	$ 10,493