Acquisitions - Purchase Price Allocation (Details) - USD ($) $ in Thousands								3 Months Ended			9 Months Ended
	May 23, 2018	Feb. 14, 2018	Oct. 02, 2017	Aug. 04, 2017	Jul. 03, 2017	May 01, 2017	Jan. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Assets Acquired
Goodwill								$ 249,023			$ 249,023		$ 238,147
Liabilities Assumed
Gain on bargain purchase								0	$ 778		0	$ (10,796)
DirectACCESS Medical, LLC
Assets Acquired
Inventories	$ 971
Goodwill	938
Total assets acquired	7,269
Liabilities Assumed
Total purchase price	7,300
DirectACCESS Medical, LLC | Developed technology
Assets Acquired
Intangibles	4,840
DirectACCESS Medical, LLC | Customer lists
Assets Acquired
Intangibles	120
DirectACCESS Medical, LLC | Trademarks
Assets Acquired
Intangibles	$ 400
Becton, Dickinson and Company
Assets Acquired
Inventories								5,804			5,804
Property and equipment								748			748
Goodwill								10,613			10,613
Total assets acquired								100,265			100,265
Liabilities Assumed
Total purchase price		$ 100,300
Becton, Dickinson and Company | Developed technology
Assets Acquired
Intangibles								74,000			74,000
Becton, Dickinson and Company | Customer lists
Assets Acquired
Intangibles								4,200			4,200
Becton, Dickinson and Company | Trademarks
Assets Acquired
Intangibles								$ 4,900			$ 4,900
ITL Healthcare Pty Ltd
Assets Acquired
Trade receivables			$ 1,287
Other receivables			56
Inventories			1,808
Prepaid expenses and other assets			65
Property and equipment			1,053
Goodwill			3,945
Total assets acquired			14,154
Liabilities Assumed
Trade payables			(216)
Accrued expenses			(747)
Deferred income tax liabilities			(1,901)
Total liabilities assumed			(2,864)
Total net assets acquired			11,290
Total purchase price			11,300
ITL Healthcare Pty Ltd | Customer lists
Assets Acquired
Intangibles			$ 5,940
Laurane Medical S.A.S.
Assets Acquired
Inventories				$ 594
Goodwill				6,366
Total assets acquired				22,000
Liabilities Assumed
Total purchase price				16,500
Laurane Medical S.A.S. | Developed technology
Assets Acquired
Intangibles				14,920
Laurane Medical S.A.S. | Customer lists
Assets Acquired
Intangibles				$ 120
Osseon LLC
Assets Acquired
Inventories					$ 979
Property and equipment					58
Goodwill					203
Total assets acquired					6,840
Liabilities Assumed
Total purchase price					6,800
Osseon LLC | Developed technology
Assets Acquired
Intangibles					5,400
Osseon LLC | Customer lists
Assets Acquired
Intangibles					$ 200
Vascular Access Technologies, Inc.
Assets Acquired
Goodwill						$ 4,281
Liabilities Assumed
Deferred income tax liabilities						(3,101)
Total net assets acquired						9,900
Total purchase price						5,000
Vascular Access Technologies, Inc. | Developed technology
Assets Acquired
Intangibles						7,800
Vascular Access Technologies, Inc. | In-process technology
Assets Acquired
Intangibles						$ 920
Argon Medical Devices, Inc.
Assets Acquired
Cash and cash equivalents							$ 1,436
Trade receivables							8,351
Inventories							11,222
Prepaid expenses and other assets							1,275
Income tax refund receivables							165
Property and equipment							2,319
Deferred income tax assets							202
Total assets acquired							29,570
Liabilities Assumed
Trade payables							(2,414)
Accrued expenses							(5,083)
Deferred income tax liabilities							(934)
Total liabilities assumed							(8,431)
Total net assets acquired							21,139
Gain on bargain purchase							(11,039)
Total purchase price							10,100
Negative adjustment (Argon Medical Devices, Inc.)										$ 1,200
Argon Medical Devices, Inc. | Developed technology
Assets Acquired
Intangibles							2,200
Argon Medical Devices, Inc. | Customer lists
Assets Acquired
Intangibles							1,500
Argon Medical Devices, Inc. | Trademarks
Assets Acquired
Intangibles							900
Catheter Connections, Inc.
Assets Acquired
Trade receivables							958
Inventories							2,157
Prepaid expenses and other assets							85
Property and equipment							1,472
Goodwill							8,989
Total assets acquired							38,361
Liabilities Assumed
Trade payables							(338)
Accrued expenses							(23)
Total liabilities assumed							(361)
Total net assets acquired							38,000
Total purchase price							38,000
Catheter Connections, Inc. | Developed technology
Assets Acquired
Intangibles							21,100
Catheter Connections, Inc. | Customer lists
Assets Acquired
Intangibles							700
Catheter Connections, Inc. | Trademarks
Assets Acquired
Intangibles							$ 2,900