Acquisitions - Narrative (Details) - USD ($) shares in Millions					3 Months Ended
	Feb. 04, 2016	Jan. 20, 2016	Dec. 04, 2015	Jul. 14, 2015	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Business Acquisition [Line Items]
Payments to acquire intangible assets					$ 482,000	$ 500,000	$ 495,000
Number of units acquired		2.0
Percent owned					15.49%
Goodwill acquired					$ 2,555,000
Payments to acquire investment		$ 2,000,000
HeRO®Graft [Member]
Business Acquisition [Line Items]
Consideration paid	$ 18,500,000
Income since acquisition date							$ 1,300,000
Weighted average useful life	9 years 9 months 26 days
Quellent, LLC
Business Acquisition [Line Items]
Payments to acquire intangible assets						500,000
Consideration paid				$ 1,000,000
Accrued purchase obligation						500,000
Noncurrent contingent consideration						270,000
Goodwill acquired						60,000
License agreements
Business Acquisition [Line Items]
Intangible Assets					17,023,000	16,671,000
Developed technology
Business Acquisition [Line Items]
Intangible Assets					79,168,000	69,861,000
Developed technology | HeRO®Graft [Member]
Business Acquisition [Line Items]
Useful life	10 years
Developed technology | Quellent, LLC
Business Acquisition [Line Items]
Useful life				13 years
Intangible Assets						1,210,000
Customer Lists
Business Acquisition [Line Items]
Intangible Assets					5,773,000	5,770,000
Customer Lists | HeRO®Graft [Member]
Business Acquisition [Line Items]
Useful life	12 years
Trademarks
Business Acquisition [Line Items]
Intangible Assets					5,272,000	$ 4,705,000
Trademarks | HeRO®Graft [Member]
Business Acquisition [Line Items]
Useful life	5 years 6 months
ArraVasc Limited
Business Acquisition [Line Items]
Payments to acquire intangible assets					$ 500,000
ArraVasc Limited | License agreements
Business Acquisition [Line Items]
Useful life			12 years
ArraVasc Limited | Additional Payments for License Agreement Milestone | License agreements
Business Acquisition [Line Items]
Potential payments on license agreement			$ 1,000,000