Business Combinations - Schedule of Purchase Price Allocation (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Feb. 01, 2016	Jan. 14, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill	$ 974,184			$ 750,288
Invotas International Corporation
Business Acquisition [Line Items]
Net tangible liabilities assumed		$ (306)
Intangible assets		8,400
Deferred tax liability		(703)
Goodwill		21,364
Total preliminary purchase price allocation		$ 28,755
iSIGHT Security
Business Acquisition [Line Items]
Net tangible liabilities assumed			$ (18,366)
Intangible assets			82,800
Deferred tax liability			(10,328)
Goodwill			202,532
Total preliminary purchase price allocation			$ 256,638