Selected Quarterly Financial Data (Unaudited) (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information [Line Items]
Net sales	$ 222,555	$ 190,117	$ 197,154	$ 186,567	$ 204,094	$ 184,792	$ 193,433	$ 181,201	$ 796,392	$ 763,520	$ 719,168
Gross Profit	123,958	102,547	104,652	99,885	106,959	101,209	102,422	97,740	431,041	408,330	381,702
Net income	46,696	$ 7,197	$ 6,139	$ (4,545)	$ 6,708	7,337	$ 2,884	(2,265)	55,487	14,664	30,498
Legal Fees									5,300	3,800
Income tax benefit, 2017 Tax Cuts and Jobs Act	$ 31,900								31,900
Restructuring charges									4,250	9,736	21,671
Debt Instrument, Financing Costs Expensed								2,700		2,700
Gain (Loss) on Extinguishment of Debt								$ (300)	0	(254)	0
Proceeds from Sale of Buildings						$ 5,200				5,200
Gain (Loss) on Sale of Properties									$ 0	$ 1,890	$ 0
EPS:
Basic (in dollars per share)	$ 1.67	$ 0.26	$ 0.22	$ (0.16)	$ 0.24	$ 0.26	$ 0.10	$ (0.08)	$ 1.99	$ 0.53	$ 1.10
Diluted (in dollars per share)	$ 1.65	$ 0.26	$ 0.22	$ (0.16)	$ 0.24	$ 0.26	$ 0.10	$ (0.08)	$ 1.97	$ 0.52	$ 1.09
Selling and Administrative Expenses [Member]
Quarterly Financial Information [Line Items]
Legal Fees	$ 400	$ 300	$ 2,500	$ 2,000	$ 1,000	$ 600	$ 1,400	$ 800	$ 17,480	$ 3,773	$ 0
Business and asset acquisition costs									2,336	17,029	2,543
Gain (Loss) on Sale of Properties						1,900			0	1,890	0
Cost of Sales [Member]
Quarterly Financial Information [Line Items]
Restructuring charges									2,903	7,612	8,016
SurgiQuestInc [Member]
Quarterly Financial Information [Line Items]
Net sales										68,400
SurgiQuestInc [Member] | Selling and Administrative Expenses [Member]
Quarterly Financial Information [Line Items]
Loss Contingency, Damages Awarded, Value				12,200					12,200
Business and asset acquisition costs	1,300	100	400	500	2,500	2,700	3,600	8,200
SurgiQuestInc [Member] | Selling and Administrative Expenses [Member] | Compensatory damages [Member]
Quarterly Financial Information [Line Items]
Loss Contingency, Damages Awarded, Value				2,200					2,200
SurgiQuestInc [Member] | Selling and Administrative Expenses [Member] | Punitive damages [Member]
Quarterly Financial Information [Line Items]
Loss Contingency, Damages Awarded, Value				10,000					10,000
Administrative Restructuring [Member] | Selling and Administrative Expenses [Member]
Quarterly Financial Information [Line Items]
Restructuring charges				1,300	2,600	$ 400	1,000	2,800	1,347	6,670	13,655
Consolidation Costs [Member] | Cost of Sales [Member]
Quarterly Financial Information [Line Items]
Restructuring charges	$ 100	$ 1,300	$ 300	$ 1,200	$ 2,100		100	$ 900	2,903	3,066	8,016
Termination of Product Offering [Member] | Cost of Sales [Member]
Quarterly Financial Information [Line Items]
Restructuring charges							$ 4,500		$ 0	$ 4,546	$ 0