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Acquisitions (Details) (USD $)	12 Months Ended	1 Months Ended
Acquisitions (Details) (USD $)	Dec. 31, 2014	Jul. 31, 2014	Jan. 31, 2014	Dec. 31, 2013	Aug. 31, 2013	Jul. 31, 2013	Jul. 31, 2012	Feb. 29, 2012	Jan. 31, 2012
Business Acquisition [Line Items]
Goodwill	$ 354,838,000us-gaap_Goodwill			$ 350,350,000us-gaap_Goodwill
Pro forma effect of business acquisition	The pro forma effect of the ongoing operations for Waters, Medimass, ULSP LaserComp, ESS, Nonlinear Dynamics, Scarabaeus, Blue Reference, the Israeli sales and service distributor and Baehr, either individually or in the aggregate, as though these acquisitions had occurred at the beginning of the periods covered by this report was immaterial.
Acquisitions in 2014 [Member]
Business Acquisition [Line Items]
Accounts receivable and other assets acquired	550,000
Intangible assets acquired	18,457,000
Goodwill	11,631,000
Total assets acquired	30,638,000
Accrued expenses and other liabilities acquired	294,000
Accrued contingent consideration	3,336,000
Cash consideration paid	27,008,000
Medimass [Member]
Business Acquisition [Line Items]
Intangible assets acquired		18,000,000
Goodwill		8,000,000
Accrued contingent consideration		3,336,000
Cash consideration paid for acquired entity		23,000,000
Medimass [Member] \| Unpatented Technology
Business Acquisition [Line Items]
Intangible assets acquired		13,000,000
Weighted-average useful life of acquired intangible assets		15 years
Medimass [Member] \| In-Process Research and Development
Business Acquisition [Line Items]
Intangible assets acquired		5,000,000
ULSP [Member]
Business Acquisition [Line Items]
Goodwill			3,000,000
Cash consideration paid for acquired entity			4,000,000
ULSP [Member] \| Unpatented Technology
Business Acquisition [Line Items]
Intangible assets acquired			1,000,000
Weighted-average useful life of acquired intangible assets			10 years
LaserComp [Member]
Business Acquisition [Line Items]
Cash consideration paid for acquired entity				12,000,000
ESS [Member]
Business Acquisition [Line Items]
Cash consideration paid for acquired entity				3,000,000
Nonlinear Dynamics [Member]
Business Acquisition [Line Items]
Cash consideration paid for acquired entity					23,000,000
Scarabaeus [Member]
Business Acquisition [Line Items]
Cash consideration paid for acquired entity						4,000,000
Blue Reference [Member]
Business Acquisition [Line Items]
Cash consideration paid for acquired entity							14,000,000
Israeli sales and service distributor [Member]
Business Acquisition [Line Items]
Cash consideration paid for acquired entity								6,000,000
Baehr [Member]
Business Acquisition [Line Items]
Cash consideration paid for acquired entity									12,000,000
Debt acquired									$ 1,000,000