Business Combination, Textuals (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Business Acquisition [Line Items]
Goodwill, Translation and Purchase Accounting Adjustments					$ (0.6)
Business Acquisition, Cost of Acquired Entity, Purchase Price	95.6				95.6
Business Acquisition, Purchase Price Allocation, Net Tangible Assets	(0.1)				(0.1)
Business Acquisition, Purchase Price Allocation, Goodwill Amount	59.0				59.0
Business Combination, Acquisition Related Costs	0.3	[1]	0	[1]	1.2	[1]	9.3	[1]
Goodwill deductible for income tax purposes	0				0
Business Acquisition Acquired Entity Mykonos [Member] | Business Acquisitions - 2012 [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Purchase Price	82.6				82.6
Business Acquisition, Purchase Price Allocation, Net Tangible Assets	(0.2)				(0.2)
Business Acquisition, Purchase Price Allocation, Goodwill Amount	58.5				58.5
Business Acquisition Acquired Entity BitGravity [Member] | Business Acquisitions - 2012 [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Purchase Price	13.0				13.0
Business Acquisition, Purchase Price Allocation, Net Tangible Assets	0.1				0.1
Business Acquisition, Purchase Price Allocation, Goodwill Amount	$ 0.5				$ 0.5

[1] Amount includes acquisition-related costs reported in operating expenses and in cost of revenues.