Acquisitions - Purchase Price Allocation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Feb. 04, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets Acquired
Goodwill	$ 211,927		$ 184,472	$ 184,464
HeRO®Graft
Assets Acquired
Inventories		$ 2,455
Property and equipment		290
Goodwill		2,555
Total assets acquired		18,500
DFINE, Inc.
Assets Acquired
Trade receivables	4,054
Other receivables	6
Inventories	8,585
Prepaid expenses	630
Property and equipment	1,630
Other long-term assets	145
Goodwill	24,818
Total assets acquired	114,268
Liabilities Assumed
Trade payables	(1,790)
Accrued expenses	(5,298)
Deferred income tax liabilities - current	(701)
Deferred income tax liabilities - noncurrent	(10,844)
Total liabilities assumed	(18,633)
Net assets acquired, net of cash received of $1,327	95,635
Cash received	1,327
Developed technology | HeRO®Graft
Assets Acquired
Intangibles		12,100
Developed technology | DFINE, Inc.
Assets Acquired
Intangibles	67,600
Customer lists | HeRO®Graft
Assets Acquired
Intangibles		400
Customer lists | DFINE, Inc.
Assets Acquired
Intangibles	2,400
Trademarks | HeRO®Graft
Assets Acquired
Intangibles		$ 700
Trademarks | DFINE, Inc.
Assets Acquired
Intangibles	$ 4,400