Segment Information (Details) $ in Thousands		3 Months Ended								12 Months Ended
	Nov. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) segment	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment										3
Proceeds from Sale of Property Held-for-sale	$ 17,500
Gain (Loss) on Sale of Properties	$ 8,800
Segment Information
Net sales		$ 241,845	$ 284,178	$ 308,007	$ 244,779	$ 231,681	$ 262,476	$ 263,002	$ 219,867	$ 1,078,809	$ 977,025	$ 860,661
Income from operations		18,871	59,680	60,886	32,895	24,363	46,712	44,614	22,226	172,332	137,915	141,210
Depreciation and amortization										39,393	33,724	27,927
Impairment of goodwill		6,686	0	0	0	0	0	0	0	6,686	0	0
Business Combination, Bargain Purchase, Gain Recognized, Amount										0	6,336	0
Significant non-cash charges										11,176	13,908	13,946
Provision for income taxes		5,293	$ 16,473	$ 16,476	$ 7,253	10,829	$ 16,581	$ 16,712	$ 7,679	45,495	51,801	49,166
Capital expenditures and asset acquisitions, net of cash acquired										31,317	85,962	47,363
Total assets		1,021,663				1,037,523				1,021,663	1,037,523	979,974
Cash and short-term investments		160,180				168,514				160,180	168,514	226,537	$ 258,825
Administrative and all other
Segment Information
Net sales										0	0	0
Income from operations										8,865	901	(178)
Depreciation and amortization										797	901	1,477
Impairment of goodwill										0
Business Combination, Bargain Purchase, Gain Recognized, Amount											0
Significant non-cash charges										3,619	2,473	3,657
Provision for income taxes										2,797	1,824	1,470
Capital expenditures and asset acquisitions, net of cash acquired										0	0	0
Total assets		(280,430)				(150,970)				(280,430)	(150,970)	(64,091)
Cash and short-term investments		113,600				80,200				113,600	80,200	137,400
Intersegment elimination
Segment Information
Net sales										32,344	24,911	31,772
North America
Segment Information
Net sales										910,587	803,697	742,021
Income from operations										164,453	132,995	137,466
Depreciation and amortization										30,505	25,745	19,433
Impairment of goodwill										0
Business Combination, Bargain Purchase, Gain Recognized, Amount											0
Significant non-cash charges										6,340	9,861	9,124
Provision for income taxes										39,638	47,434	45,547
Capital expenditures and asset acquisitions, net of cash acquired										27,059	70,040	37,652
Total assets		1,119,012				953,033				1,119,012	953,033	853,826
North America | Intersegment elimination
Segment Information
Net sales										2,279	3,237	2,512
Europe
Segment Information
Net sales										159,027	165,155	111,274
Income from operations										(3,026)	2,723	2,115
Depreciation and amortization										6,297	5,832	5,809
Impairment of goodwill										6,686
Business Combination, Bargain Purchase, Gain Recognized, Amount											6,336
Significant non-cash charges										1,169	1,509	1,052
Provision for income taxes										2,947	2,124	1,428
Capital expenditures and asset acquisitions, net of cash acquired										2,556	11,411	8,461
Total assets		157,437				208,640				157,437	208,640	165,121
Europe | Intersegment elimination
Segment Information
Net sales										1,773	959	570
Asia/Pacific
Segment Information
Net sales										9,195	8,173	7,366
Income from operations										2,040	1,296	1,807
Depreciation and amortization										1,794	1,246	1,208
Impairment of goodwill										0
Business Combination, Bargain Purchase, Gain Recognized, Amount											0
Significant non-cash charges										48	65	113
Provision for income taxes										113	419	721
Capital expenditures and asset acquisitions, net of cash acquired										1,702	4,511	1,250
Total assets		25,644				$ 26,820				25,644	26,820	25,118
Asia/Pacific | Intersegment elimination
Segment Information
Net sales										28,292	$ 20,715	$ 28,690
Foreign operating entities
Segment Information
Cash and short-term investments		$ 45,500								$ 45,500
Percentage of cash and cash equivalents		28.40%								28.40%