Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014 segment		Sep. 30, 2013		Dec. 31, 2013	Dec. 31, 2012
Segment Reporting [Abstract]
Number of reportable segments					3
Segment Information
Net sales	$ 209,320		$ 195,619		$ 585,518		$ 545,248
Income (Loss) from Operations	32,218		30,885		83,956		69,575
Total Assets	981,843		934,176		981,843		934,176		953,613
Cash and cash equivalent	258,238		215,764		258,238		215,764		251,208	175,553
Intersegment elimination
Segment Information
Net sales	7,256	[1]	5,304	[1]	17,303	[1]	16,558	[1]
Administrative and all other
Segment Information
Income (Loss) from Operations	(995)		(807)		(3,142)		(3,871)
Total Assets	77,285		74,002		77,285		74,002		93,473
Cash and cash equivalent	166,800		120,100		166,800		120,100		156,000
North America
Segment Information
Net sales	171,064		157,278		476,546		444,772
Income (Loss) from Operations	29,914		28,659		82,598		73,582
Total Assets	684,820		630,459		684,820		630,459		627,196
North America | Intersegment elimination
Segment Information
Net sales	1,058	[1]	1,316	[1]	3,151	[1]	3,247	[1]
Europe
Segment Information
Net sales	34,609		33,866		97,297		89,855
Income (Loss) from Operations	3,447		3,682		6,283		1,742
Total Assets	190,359		196,958		190,359		196,958		201,384
Europe | Intersegment elimination
Segment Information
Net sales	308	[1]	20	[1]	934	[1]	332	[1]
Asia/Pacific
Segment Information
Net sales	3,647		4,475		11,675		10,621
Income (Loss) from Operations	(148)		(649)		(1,783)		(1,878)
Total Assets	29,379		32,757		29,379		32,757		31,560
Asia/Pacific | Intersegment elimination
Segment Information
Net sales	$ 5,890	[1]	$ 3,968	[1]	$ 13,218	[1]	$ 12,979	[1]

[1] The sales to other segments are eliminated in consolidation.