Reconciliation of Effective Income Tax Rate (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
U.S. federal statutory income tax rate									35.00%		35.00%		35.00%
Income tax provision at U.S. federal statutory rate									$ 258.4		$ 157.7		$ 81.3
State and local income taxes, net of federal income tax benefit									15.3		10.8		22.1
Impact of foreign operations, including withholding taxes									(21.9)		4.7		26.9
Change in net valuation allowance									(32.9)	[1]	(2.4)	[1]	12.4	[1]
Worthless securities deduction									(23.0)		(2.5)		(2.3)
(Decreases) increases in unrecognized tax benefits, net									(2.7)		8.9		(55.6)
Stock based compensation									0.2		0.2		16.4
Other									(3.2)		(6.1)		(11.1)
Total provision for income taxes	$ 93.7	$ 70.4	$ 47.6	$ (21.5)	$ 98.9	$ 24.4	$ 63.3	$ (15.3)	$ 190.2		$ 171.3		$ 90.1
Effective income tax rate on operations									25.80%		38.00%		38.80%

[1] Reflects changes in valuation allowance that impacted the effective income tax rate for each year presented.