Provision for Income Taxes (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
U.S. federal income taxes (including foreign withholding taxes):
Current federal income taxes									$ 0.9	$ 13.7	$ (48.4)
Deferred federal income taxes									92.3	60.2	38.7
Total federal income taxes									93.2	73.9	(9.7)
State and local income taxes:
Current state and local income taxes									12.3	16.8	(6.1)
Deferred state and local income taxes									11.3	(0.1)	40.1
Total state and local income taxes									23.6	16.7	34.0
Foreign income taxes:
Current foreign income taxes									93.1	84.8	55.4
Deferred foreign income taxes									(19.7)	(4.1)	10.4
Total foreign income taxes									73.4	80.7	65.8
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