Acquisitions - Purchase Price Allocation (Catheter Connections, Inc.) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill	$ 234,043	$ 211,927
Catheter Connections, Inc.
Business Acquisition [Line Items]
Trade receivables	959
Inventories	2,157
Prepaid expenses	85
Property and equipment	1,472
Goodwill	8,988
Total assets acquired	38,361
Trade payables	(338)
Accrued expenses	(23)
Total liabilities assumed	(361)
Net assets acquired, net of cash received of $1,327	38,000
Preliminary Allocation | Catheter Connections, Inc.
Business Acquisition [Line Items]
Trade receivables	952
Inventories	2,244
Prepaid expenses	181
Property and equipment	1,472
Goodwill	7,612
Total assets acquired	38,361
Trade payables	(338)
Accrued expenses	(23)
Total liabilities assumed	(361)
Net assets acquired, net of cash received of $1,327	38,000
Adjustment | Catheter Connections, Inc.
Business Acquisition [Line Items]
Trade receivables	7
Inventories	(87)
Prepaid expenses	(96)
Property and equipment	0
Goodwill	1,376
Total assets acquired	0
Trade payables	0
Accrued expenses	0
Total liabilities assumed	0
Net assets acquired, net of cash received of $1,327	0
Developed Technology Rights | Catheter Connections, Inc.
Business Acquisition [Line Items]
Intangibles	21,100
Developed Technology Rights | Preliminary Allocation | Catheter Connections, Inc.
Business Acquisition [Line Items]
Intangibles	22,900
Developed Technology Rights | Adjustment | Catheter Connections, Inc.
Business Acquisition [Line Items]
Intangibles	(1,800)
Customer lists | Catheter Connections, Inc.
Business Acquisition [Line Items]
Intangibles	700
Customer lists | Preliminary Allocation | Catheter Connections, Inc.
Business Acquisition [Line Items]
Intangibles	100
Customer lists | Adjustment | Catheter Connections, Inc.
Business Acquisition [Line Items]
Intangibles	600
Trademarks | Catheter Connections, Inc.
Business Acquisition [Line Items]
Intangibles	2,900
Trademarks | Preliminary Allocation | Catheter Connections, Inc.
Business Acquisition [Line Items]
Intangibles	2,900
Trademarks | Adjustment | Catheter Connections, Inc.
Business Acquisition [Line Items]
Intangibles	$ 0