Income Taxes Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Sep. 30, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Gain recorded on sale of portion of Facebook	$ 132.2	$ 132.2	$ 0	$ 0
One hundred percent valuation allowance		100.00%
Tax credit carryforward amount		32.9
Tax credit carryforward, expiration date		2013
Operating loss carryforwards		1,413.5
Undistributed foreign earnings		1,766.7	1,547.1
Unrecognized tax benefits		161.0	146.7	160.5	174.9
Unrecognized tax benefits that would impact effective tax rate		160.1
Income tax penalties and interest accrued		12.1	11.9
Income tax penalties and interest expense		(0.2)	5.0
Estimated unrecognized tax benefit decrease, lower bound		5.0
Estimated unrecognized tax benefit decrease, upper bound		15.0
Domestic country
Operating loss carryforwards		58.4
Operating loss carryforwards, expiration date		expire in the years 2029 through 2030
Domestic country | Minimum [Member]
Income tax examination year		2007
Open tax years		2009
Domestic country | Maximum [Member]
Income tax examination year		2008
State and local jurisdiction | Minimum [Member]
Open tax years		1999
Foreign country
Operating loss carryforwards		1,355.1
Operating loss carryforwards, expiration date		expiration periods from 2012 through 2030
Operating loss carryforwards, no expiration		1,094.3
Operating loss carryforwards, subject to expiration		$ 260.8
Foreign country | Minimum [Member]
Open tax years		2004