Segment Reporting and Foreign Operations - Sales by Business Segment (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
Revenue from External Customer [Line Items]
Revenues	$ 132,780	$ 128,808	$ 128,865	$ 119,236	$ 120,016	$ 115,210	$ 109,875	$ 103,948	$ 509,689	$ 449,049	$ 394,288
% Change	14.00%				14.00%				14.00%	14.00%	10.00%
Cardiovascular Segment
Revenue from External Customer [Line Items]
Revenues									491,706	432,124	378,493
% Change	14.00%				14.00%				14.00%	14.00%	9.00%
Cardiovascular Segment | Stand Alone Devices
Revenue from External Customer [Line Items]
Revenues									143,712	125,445	114,242
% Change	15.00%				10.00%				15.00%	10.00%	12.00%
Cardiovascular Segment | Custom Kit And Procedures Trays
Revenue from External Customer [Line Items]
Revenues									111,076	103,700	94,586
% Change	7.00%				10.00%				7.00%	10.00%	3.00%
Cardiovascular Segment | Inflation Devices
Revenue from External Customer [Line Items]
Revenues									72,538	66,182	68,979
% Change	10.00%				(4.00%)				10.00%	(4.00%)	2.00%
Cardiovascular Segment | Catheters
Revenue from External Customer [Line Items]
Revenues									87,550	75,131	64,878
% Change	17.00%				16.00%				17.00%	16.00%	17.00%
Cardiovascular Segment | Embolization Devices
Revenue from External Customer [Line Items]
Revenues									43,855	33,395	33,870
% Change	31.00%				(1.00%)				31.00%	(1.00%)	8.00%
Cardiovascular Segment | Electrophysiology
Revenue from External Customer [Line Items]
Revenues									32,975	28,271	1,938
% Change	17.00%				1359.00%				17.00%	1359.00%	0.00%
Endoscopy Segment
Revenue from External Customer [Line Items]
Revenues									17,983	16,925	15,795
Endoscopy Segment | Endoscopy Devices
Revenue from External Customer [Line Items]
Revenues									$ 17,983	$ 16,925	$ 15,795
% Change	6.00%				7.00%				6.00%	7.00%	31.00%