Segment Reporting and Foreign Operations - Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net Sales	$ 233,249	$ 221,659	$ 224,810	$ 203,035	$ 190,897	$ 179,337	$ 186,549	$ 171,069	$ 882,753	$ 727,852	$ 603,838
Operating expenses									336,153	293,184	230,149
Operating income (loss)	13,661	21,061	15,114	8,781	13,219	879	13,362	5,609	58,617	33,069	34,876
Total other income (expense) - net									(9,098)	2,812	(9,490)
Income tax expense	3,022	2,766	624	1,090	4,474	1,364	1,830	690	7,502	8,358	5,265
NET INCOME	$ 9,188	$ 16,619	$ 10,941	$ 5,269	$ 6,806	$ (3,569)	$ 9,483	$ 14,803	42,017	27,523	20,121
Cardiovascular
Segment Reporting Information [Line Items]
Net Sales									849,477	700,613	580,151
Operating expenses									321,461	281,095	218,659
Operating income (loss)									49,289	24,819	30,053
Endoscopy
Segment Reporting Information [Line Items]
Net Sales									33,276	27,239	23,687
Operating expenses									14,692	12,089	11,490
Operating income (loss)									$ 9,328	$ 8,250	$ 4,823