Business Combination, Intangible Assets Acquired (Details) (Business Acquisitions - 2012 [Member], USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Business Acquisition [Line Items]
Acquired Finite and Indefinite Lived intangible Assets, Amount	36.7
Existing or Core Technology [Member]
Business Acquisition [Line Items]
Acquired finite-lived intangible asset, weighted average estimated useful life (in years)	5 years
Trade Name and Trademarks [Member]
Business Acquisition [Line Items]
Acquired finite-lived intangible asset, weighted average estimated useful life (in years)	7 years
Business Acquisition Acquired Entity Mykonos [Member]
Business Acquisition [Line Items]
Acquired Finite and Indefinite Lived intangible Assets, Amount	24.3
Business Acquisition Acquired Entity Mykonos [Member] | Existing or Core Technology [Member]
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, amount	31.7
Business Acquisition Acquired Entity Mykonos [Member] | Trade Name and Trademarks [Member]
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, amount	1.0
Business Acquisition Acquired Entity Mykonos [Member] | In Process Research And Development [Member]
Business Acquisition [Line Items]
Acquired Indefinite-lived Intangible Asset, Amount	4.0
Business Acquisition Acquired Entity BitGravity [Member]
Business Acquisition [Line Items]
Acquired Finite and Indefinite Lived intangible Assets, Amount	12.4