Acquisitions - Triune Purchase Price Allocation (Details) - USD ($) $ in Thousands	Jul. 31, 2016	Jan. 31, 2016	Mar. 04, 2015
Business Acquisition [Line Items]
Goodwill	$ 329,703	$ 329,703
Earn-out liability	(7,593)	(6,259)
Triune Systems [Member]
Business Acquisition [Line Items]
Current assets			$ 877
Property, plant, and equipment, net			226
Goodwill			49,384
Current liabilities			(1,287)
Earn-out liability	$ 0	$ 0	(16,200)
Total acquisition consideration			45,000
Core Technologies [Member] | Triune Systems [Member]
Business Acquisition [Line Items]
Amortizable intangible assets			10,000
Customer Relationships [Member] | Triune Systems [Member]
Business Acquisition [Line Items]
Amortizable intangible assets			$ 2,000