Acquisitions - Purchase Price Allocation (DFINE Inc. and HeRO Graft) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Sep. 30, 2017	Feb. 04, 2016
Assets Acquired
Goodwill	$ 211,927	$ 234,043
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 Rights | HeRO®Graft
Assets Acquired
Intangibles			12,100
Developed Technology Rights | 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