Goodwill and Intangible Assets, Net - Amortization Expense by Income Statement Caption (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 1,776	$ 1,791	$ 3,578	$ 3,391
Cost of sales
Finite-Lived Intangible Assets [Line Items]
Amortization expense	18	55	73	74
Selling, general and administrative expenses
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 1,758	$ 1,736	$ 3,505	$ 3,317