Business Combinations - Schedule of Intangible Assets Acquired (Details) - USD ($) $ in Thousands	Dec. 31, 2014	May. 09, 2014	Dec. 30, 2013
nPulse Technologies
Acquired Finite-Lived Intangible Assets [Line Items]
Total		$ 24,700
nPulse Technologies | In process research and development [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets		6,600
nPulse Technologies | Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets		10,100
nPulse Technologies | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets		$ 8,000
Mandiant, Inc.
Acquired Finite-Lived Intangible Assets [Line Items]
Total	$ 276,200		$ 276,200
Mandiant, Inc. | In process research and development [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets			1,400
Mandiant, Inc. | Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets			54,600
Mandiant, Inc. | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets			65,400
Mandiant, Inc. | Contract backlog
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets			13,800
Mandiant, Inc. | Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets			$ 12,400