Segment Reporting and Foreign Operations - Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 257,922	$ 243,049	$ 255,532	$ 238,349	$ 233,249	$ 221,659	$ 224,810	$ 203,035	$ 994,852	$ 882,753	$ 727,852
Operating expenses									416,932	336,153	293,184
Operating income	(3,409)	(2,881)	12,201	9,523	13,661	21,061	15,114	8,781	15,434	58,617	33,069
Total other income (expense) - net									(13,241)	(9,098)	2,812
Income tax expense (benefit)	(3,757)	(2,292)	2,140	651	3,022	2,766	624	1,090	(3,258)	7,502	8,358
NET INCOME	$ (4,205)	$ (3,398)	$ 6,859	$ 6,195	$ 9,188	$ 16,619	$ 10,941	$ 5,269	5,451	42,017	27,523
Cardiovascular
Segment Reporting Information [Line Items]
Net sales									960,981	849,477	700,613
Operating expenses									382,313	321,461	281,095
Operating income									25,780	49,289	24,819
Endoscopy
Segment Reporting Information [Line Items]
Net sales									33,871	33,276	27,239
Operating expenses									34,619	14,692	12,089
Operating income									$ (10,346)	$ 9,328	$ 8,250