Summary of Significant Accounting Policies - Additional Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 01, 2017
Class of Warrant or Right [Line Items]
Advertising costs	$ 1,100	$ 1,100	$ 1,100
Other shipping and handling costs	$ 12,200	11,600	$ 12,700
Maturity of foreign currency exchange contracts	9 months
Retained earnings	$ 266,780	275,594
Deferred income taxes	$ 7,913
Impact to retained earnings from adoption of ASU 2016-09		1,509
Performance-based warrants
Class of Warrant or Right [Line Items]
Dividend yield	0.00%
Accounting Standards Update 2016-09
Class of Warrant or Right [Line Items]
Deferred income taxes				$ 1,500
Retained Earnings
Class of Warrant or Right [Line Items]
Impact to retained earnings from adoption of ASU 2016-09		$ 1,509
Retained Earnings | Accounting Standards Update 2016-09
Class of Warrant or Right [Line Items]
Impact to retained earnings from adoption of ASU 2016-09				$ 1,500
Minimum | Cumulative-effect adjustment | Pro Forma | Accounting Standards Update 2014-09
Class of Warrant or Right [Line Items]
Retained earnings	$ 4,000
Maximum | Cumulative-effect adjustment | Pro Forma | Accounting Standards Update 2014-09
Class of Warrant or Right [Line Items]
Retained earnings	$ 5,000