Segment Information - Geographic Information - Net Sales (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Information
Net sales	$ 137,480	$ 123,970	$ 132,597	$ 120,199	$ 130,873	$ 132,976	$ 135,452	$ 135,703	$ 514,246	$ 535,004	$ 555,103
United States
Segment Information
Net sales									271,076	288,645	261,849
United Kingdom
Segment Information
Net sales									36,552	43,217	46,049
Japan
Segment Information
Net sales									35,243	35,753	45,261
France
Segment Information
Net sales									23,646	20,875	28,575
Germany
Segment Information
Net sales									21,416	17,804	20,656
China
Segment Information
Net sales									18,559	17,943	17,166
Canada
Segment Information
Net sales									13,858	17,065	21,910
South Korea
Segment Information
Net sales									10,231	12,218	18,692
Belgium
Segment Information
Net sales									9,373	10,383	11,166
Netherlands
Segment Information
Net sales									5,696	5,184	5,466
Italy
Segment Information
Net sales									5,206	2,432	2,215
Singapore
Segment Information
Net sales									4,126	9,923	6,418
Spain
Segment Information
Net sales									3,812	3,302	4,049
Mexico
Segment Information
Net sales									3,705	2,662	3,751
Denmark
Segment Information
Net sales									3,588	4,252	3,978
Other
Segment Information
Net sales									$ 48,159	$ 43,346	$ 57,902