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Segment Reporting and Foreign Operations - Operating Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Revenues	$ 132,780us-gaap_SalesRevenueGoodsNet	$ 128,808us-gaap_SalesRevenueGoodsNet	$ 128,865us-gaap_SalesRevenueGoodsNet	$ 119,236us-gaap_SalesRevenueGoodsNet	$ 120,016us-gaap_SalesRevenueGoodsNet	$ 115,210us-gaap_SalesRevenueGoodsNet	$ 109,875us-gaap_SalesRevenueGoodsNet	$ 103,948us-gaap_SalesRevenueGoodsNet	$ 509,689us-gaap_SalesRevenueGoodsNet	$ 449,049us-gaap_SalesRevenueGoodsNet	$ 394,288us-gaap_SalesRevenueGoodsNet
Operating expenses									185,056us-gaap_OperatingExpenses	166,523us-gaap_OperatingExpenses	152,351us-gaap_OperatingExpenses
Operating income (loss)									40,166us-gaap_OperatingIncomeLoss	27,844us-gaap_OperatingIncomeLoss	29,641us-gaap_OperatingIncomeLoss
Total other expense - net									(8,594)us-gaap_NonoperatingIncomeExpense	(8,005)us-gaap_NonoperatingIncomeExpense	(2,023)us-gaap_NonoperatingIncomeExpense
Income tax expense	3,680us-gaap_IncomeTaxExpenseBenefit	2,489us-gaap_IncomeTaxExpenseBenefit	1,366us-gaap_IncomeTaxExpenseBenefit	1,063us-gaap_IncomeTaxExpenseBenefit	1,642us-gaap_IncomeTaxExpenseBenefit	833us-gaap_IncomeTaxExpenseBenefit	1,253us-gaap_IncomeTaxExpenseBenefit	(459)us-gaap_IncomeTaxExpenseBenefit	8,598us-gaap_IncomeTaxExpenseBenefit	3,269us-gaap_IncomeTaxExpenseBenefit	7,908us-gaap_IncomeTaxExpenseBenefit
NET INCOME									22,974us-gaap_ProfitLoss	16,570us-gaap_ProfitLoss	19,710us-gaap_ProfitLoss
Cardiovascular Segment
Segment Reporting Information [Line Items]
Revenues									491,706	432,124	378,493
Operating expenses									175,152	157,479	142,089
Operating income (loss)									38,601	26,597	30,411
Endoscopy Segment
Segment Reporting Information [Line Items]
Revenues									17,983	16,925	15,795
Operating expenses									9,904	9,044	10,262
Operating income (loss)									$ 1,565	$ 1,247	$ (770)