Business Combinations - Total Purchase Price and Identifiable Intangible Assets (Details) - USD ($) $ in Thousands					12 Months Ended
	Apr. 30, 2015	Apr. 30, 2015	Apr. 21, 2015	Aug. 22, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Cash	$ 3,789	$ 3,789
Accounts receivable	7,350	7,350
Inventory	5,008	5,008
Deferred tax assets and other current assets	457	457
Total current assets	16,604	16,604
Property and equipment	463	463
Intangibles	14,051	14,051
Goodwill	26,197	26,197			$ 147,906	$ 122,720	$ 111,343
Other non-current assets	52	52
Total assets	57,367	57,367
Current liabilities	7,809	7,809
Long-term deferred tax liabilities	3,833	3,833
Deferred service revenue and gross profit	3,242	3,242
Other non-current liabilities	1,056	1,056
Total purchase price	41,427	41,427
Payments to Acquire Businesses, Net of Cash Acquired		37,638			$ 25,507	$ 20,723	$ 0
Surgichem
Business Acquisition [Line Items]
Cash				$ 153
Accounts receivable				2,462
Inventory				2,190
Deferred tax assets and other current assets				361
Total current assets				5,166
Property and equipment				164
Intangibles				5,730
Goodwill				12,112
Total assets				23,172
Current liabilities				1,191
Long-term deferred tax liabilities				1,104
Total purchase price				20,877
Payments to Acquire Businesses, Net of Cash Acquired				$ 20,700
Surgichem | Trade name
Identifiable Intangible Assets
Weighted average useful life (in years)				1 year
Surgichem | Customer relationships
Identifiable Intangible Assets
Weighted average useful life (in years)				18 years
Mach4
Business Acquisition [Line Items]
Cash			$ 397
Accounts receivable			3,743
Inventory			3,580
Deferred tax assets and other current assets			368
Total current assets			8,088
Property and equipment			463
Intangibles			7,710
Goodwill			10,591
Other non-current assets			52
Total assets			26,904
Current liabilities			3,684
Long-term deferred tax liabilities			2,564
Deferred service revenue and gross profit			2,314
Other non-current liabilities			1,056
Total purchase price			17,286
Payments to Acquire Businesses, Net of Cash Acquired			16,889
Identifiable Intangible Assets
Fair value of identifiable intangible assets purchased			7,710
Mach4 | Developed technology
Identifiable Intangible Assets
Fair value of identifiable intangible assets purchased			$ 3,290
Weighted average useful life (in years)			8 years
Mach4 | Trade name
Identifiable Intangible Assets
Fair value of identifiable intangible assets purchased			$ 850
Weighted average useful life (in years)			6 years
Mach4 | Customer relationships
Identifiable Intangible Assets
Fair value of identifiable intangible assets purchased			$ 3,570
Weighted average useful life (in years)			10 years
Avantec
Business Acquisition [Line Items]
Cash	3,392	3,392
Accounts receivable	3,607	3,607
Inventory	1,428	1,428
Deferred tax assets and other current assets	89	89
Total current assets	8,516	8,516
Property and equipment	0	0
Intangibles	6,341	6,341
Goodwill	15,606	15,606
Other non-current assets	0	0
Total assets	30,463	30,463
Current liabilities	4,125	4,125
Long-term deferred tax liabilities	1,269	1,269
Deferred service revenue and gross profit	928	928
Other non-current liabilities	0	0
Total purchase price	24,141	$ 24,141
Payments to Acquire Businesses, Net of Cash Acquired	20,749
Identifiable Intangible Assets
Fair value of identifiable intangible assets purchased	6,341
Avantec | Developed technology
Identifiable Intangible Assets
Fair value of identifiable intangible assets purchased	0
Avantec | Trade name
Identifiable Intangible Assets
Fair value of identifiable intangible assets purchased	$ 92
Weighted average useful life (in years)	2 years
Avantec | Customer relationships
Identifiable Intangible Assets
Fair value of identifiable intangible assets purchased	$ 5,834
Weighted average useful life (in years)	12 years
Avantec | Backlog
Identifiable Intangible Assets
Fair value of identifiable intangible assets purchased	$ 415
Weighted average useful life (in years)	2 years
Income Approach Valuation Technique | Mach4 | Developed technology
Business Acquisition [Line Items]
Fair value inputs, royalty rate			5.00%
Fair value inputs, discount rate			17.50%
Income Approach Valuation Technique | Mach4 | Trade name
Business Acquisition [Line Items]
Fair value inputs, royalty rate			2.00%
Income Approach Valuation Technique | Mach4 | Minimum | Developed technology
Business Acquisition [Line Items]
Fair value inputs, discount rate			1.50%
Income Approach Valuation Technique | Avantec | Trade name
Business Acquisition [Line Items]
Fair value inputs, royalty rate	1.00%