Segment Reporting - Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Net sales	$ 243,049			$ 221,659			$ 736,930	$ 649,504
Operating income	(2,881)			21,061			18,844	44,955
Total other expense - net	(2,809)			(1,676)			(8,689)	(7,646)
Income tax expense (benefit)	(2,292)			2,766			499	4,481
Net income	(3,398)	$ 6,859	$ 6,195	16,619	$ 10,941	$ 5,269	9,656	32,828
Cardiovascular
Segment Reporting Information [Line Items]
Net sales	234,426			212,150			711,570	624,392
Operating income	(6,210)			18,199			11,263	37,263
Endoscopy
Segment Reporting Information [Line Items]
Net sales	8,623			9,509			25,360	25,112
Operating income	$ 3,329			$ 2,862			$ 7,581	$ 7,692