Provision for Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
U.S. federal income taxes (including foreign withholding taxes):
Current federal income taxes									$ 9.4	$ 0.9	$ 13.7
Deferred federal income taxes									118.1	92.3	60.2
Total federal income taxes									127.5	93.2	73.9
State and local income taxes:
Current state and local income taxes									17.1	12.3	16.8
Deferred state and local income taxes									25.3	11.3	(0.1)
Total state and local income taxes									42.4	23.6	16.7
Foreign income taxes:
Current foreign income taxes									83.2	93.1	84.8
Deferred foreign income taxes									(39.8)	(19.7)	(4.1)
Total foreign income taxes									43.4	73.4	80.7
Total provision for income taxes	$ 140.5	$ 41.9	$ 50.1	$ (19.2)	$ 93.7	$ 70.4	$ 47.6	$ (21.5)	$ 213.3	$ 190.2	$ 171.3