Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Net sales	$ 224,810	$ 186,549	$ 427,844	$ 357,618
United States
Disaggregation of Revenue [Line Items]
Net sales	124,445	108,106	234,501	210,222
International
Disaggregation of Revenue [Line Items]
Net sales	100,365	78,443	193,343	147,396
Cardiovascular
Disaggregation of Revenue [Line Items]
Net sales	216,387	179,663	412,241	344,418
Cardiovascular | United States
Disaggregation of Revenue [Line Items]
Net sales	116,324	101,394	219,461	197,416
Cardiovascular | International
Disaggregation of Revenue [Line Items]
Net sales	100,063	78,269	192,780	147,002
Endoscopy
Disaggregation of Revenue [Line Items]
Net sales	8,423	6,886	15,603	13,200
Stand-alone devices | Cardiovascular
Disaggregation of Revenue [Line Items]
Net sales	92,496	71,056	175,742	134,709
Stand-alone devices | Cardiovascular | United States
Disaggregation of Revenue [Line Items]
Net sales	50,941	37,202	94,953	73,366
Stand-alone devices | Cardiovascular | International
Disaggregation of Revenue [Line Items]
Net sales	41,555	33,854	80,789	61,343
Custom kits and procedure trays | Cardiovascular
Disaggregation of Revenue [Line Items]
Net sales	33,992	31,797	67,264	60,672
Custom kits and procedure trays | Cardiovascular | United States
Disaggregation of Revenue [Line Items]
Net sales	23,667	24,271	45,984	45,737
Custom kits and procedure trays | Cardiovascular | International
Disaggregation of Revenue [Line Items]
Net sales	10,325	7,526	21,280	14,935
Inflation devices | Cardiovascular
Disaggregation of Revenue [Line Items]
Net sales	24,305	20,789	46,724	39,296
Inflation devices | Cardiovascular | United States
Disaggregation of Revenue [Line Items]
Net sales	8,160	8,042	15,828	16,017
Inflation devices | Cardiovascular | International
Disaggregation of Revenue [Line Items]
Net sales	16,145	12,747	30,896	23,279
Catheters | Cardiovascular
Disaggregation of Revenue [Line Items]
Net sales	39,374	32,429	73,239	62,605
Catheters | Cardiovascular | United States
Disaggregation of Revenue [Line Items]
Net sales	16,704	16,022	31,974	31,151
Catheters | Cardiovascular | International
Disaggregation of Revenue [Line Items]
Net sales	22,670	16,407	41,265	31,454
Embolization devices | Cardiovascular
Disaggregation of Revenue [Line Items]
Net sales	12,724	12,158	25,310	24,685
Embolization devices | Cardiovascular | United States
Disaggregation of Revenue [Line Items]
Net sales	5,094	5,593	10,126	11,134
Embolization devices | Cardiovascular | International
Disaggregation of Revenue [Line Items]
Net sales	7,630	6,565	15,184	13,551
CRM/EP | Cardiovascular
Disaggregation of Revenue [Line Items]
Net sales	13,496	11,434	23,962	22,451
CRM/EP | Cardiovascular | United States
Disaggregation of Revenue [Line Items]
Net sales	11,758	10,264	20,596	20,011
CRM/EP | Cardiovascular | International
Disaggregation of Revenue [Line Items]
Net sales	1,738	1,170	3,366	2,440
Endoscopy devices | Endoscopy
Disaggregation of Revenue [Line Items]
Net sales	8,423	6,886	15,603	13,200
Endoscopy devices | Endoscopy | United States
Disaggregation of Revenue [Line Items]
Net sales	8,121	6,712	15,040	12,806
Endoscopy devices | Endoscopy | International
Disaggregation of Revenue [Line Items]
Net sales	$ 302	$ 174	$ 563	$ 394