Segment Reporting and Foreign Operations - Operating Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Revenues	$ 102,231	$ 95,907	$ 100,532	$ 95,618	$ 91,092	$ 90,477	$ 91,249	$ 86,631	$ 394,288	$ 359,449	$ 296,755
Operating expenses									152,351	132,278	102,950
Goodwill impairment charge									0	0	8,344
Operating income (loss)									29,641	33,190	17,204
Total other expense - net									(2,023)	(315)	(416)
Income tax expense	1,209	1,811	2,719	2,169	806	2,120	3,746	3,159	7,908	9,831	4,328
NET INCOME									19,710	23,044	12,460
Cardiovascular Segment [Member]
Segment Reporting Information [Line Items]
Revenues									378,493	347,430	287,707
Operating expenses									142,089	122,600	93,884
Goodwill impairment charge									0	0	0
Operating income (loss)									30,411	38,010	30,176
Endoscopy Segment [Member]
Segment Reporting Information [Line Items]
Revenues									15,795	12,019	9,048
Operating expenses									10,262	9,678	9,066
Goodwill impairment charge									0	0	8,344
Operating income (loss)									$ (770)	$ (4,820)	$ (12,972)