Segment Reporting and Foreign Operations - Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 138,404	$ 136,086	$ 138,082	$ 129,577	$ 132,780	$ 128,808	$ 128,865	$ 119,236	$ 542,149	$ 509,689	$ 449,049
Operating expenses									198,238	185,056	166,523
Operating income (loss)									37,543	40,166	27,844
Total other expense - net									(6,343)	(8,594)	(8,005)
Income tax expense	145	1,842	3,122	2,289	3,680	2,489	1,366	1,063	7,398	8,598	3,269
NET INCOME	$ 6,409	$ 4,818	$ 7,401	$ 5,174	$ 8,671	$ 7,764	$ 3,716	$ 2,823	23,802	22,974	16,570
Cardiovascular Segment
Segment Reporting Information [Line Items]
Revenues									520,915	491,706	432,124
Operating expenses									187,492	175,152	157,479
Operating income (loss)									34,052	38,601	26,597
Endoscopy Segment
Segment Reporting Information [Line Items]
Revenues									21,234	17,983	16,925
Operating expenses									10,746	9,904	9,044
Operating income (loss)									$ 3,491	$ 1,565	$ 1,247