Equity, Accumulated Other Comprehensive (Loss) Income, Net of Tax (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Accumulated Other Comprehensive (Loss) Income, Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, Beginning balance	$ 4.7
Other comprehensive loss before reclassifications	(8.1)
Amount reclassified from accumulated other comprehensive (loss) income	(1.8)
Other comprehensive (loss) income, net of tax	(9.9)	[1]	16.9
Accumulated other comprehensive (loss) income, Ending balance	(5.2)
Other expense, net	(10.1)		(24.4)
Cost of revenues	388.4		398.4
Research and development	262.2		269.6
Sales and marketing	255.2		257.7
General and administrative	47.8		54.7
Unrealized gains (losses) on available-for-sale securities [Member]
Accumulated Other Comprehensive (Loss) Income, Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, Beginning balance	2.1	[2]
Other comprehensive loss before reclassifications	(0.2)	[2]
Amount reclassified from accumulated other comprehensive (loss) income	(0.4)	[2]
Other comprehensive (loss) income, net of tax	(0.6)	[1],[2]
Accumulated other comprehensive (loss) income, Ending balance	1.5	[2]
Other expense, net	0.4
Unrealized gains (losses) on cash flow hedges [Member]
Accumulated Other Comprehensive (Loss) Income, Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, Beginning balance	3.0	[3]
Other comprehensive loss before reclassifications	(2.1)	[3]
Amount reclassified from accumulated other comprehensive (loss) income	(1.4)	[3]
Other comprehensive (loss) income, net of tax	(3.5)	[1],[3]
Accumulated other comprehensive (loss) income, Ending balance	(0.5)	[3]
Cost of revenues	0.2
Research and development	0.4
Sales and marketing	0.5
General and administrative	0.3
Foreign currency translation adjustments [Member]
Accumulated Other Comprehensive (Loss) Income, Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, Beginning balance	(0.4)
Other comprehensive loss before reclassifications	(5.8)
Amount reclassified from accumulated other comprehensive (loss) income	0
Other comprehensive (loss) income, net of tax	(5.8)	[1]
Accumulated other comprehensive (loss) income, Ending balance	$ (6.2)

[1] Taxes related to each component of other comprehensive loss were not material for the three months ended March 31, 2013 and March 31, 2012.

[2] The reclassifications out of accumulated comprehensive income during the three months ended March 31, 2013 for realized gains on available-for-sale securities of $0.4 million are included in other expense, net in the Condensed Consolidated Statements of Operations.

[3] The reclassifications out of accumulated comprehensive income during the three months ended March 31, 2013 for realized gains on cash flow hedges are included within cost of revenues of $0.2 million, research and development of $0.4 million, sales and marketing of $0.5 million, and general and administrative of $0.3 million for which the hedged transactions relate in the Condensed Consolidated Statements of Operations.