Provision for Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended									12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
U.S. federal income taxes (including foreign withholding taxes):
Current federal income taxes										$ 8.0	$ 46.9	$ 9.4
Deferred federal income taxes										130.7	25.2	118.1
Total federal income taxes										138.7	72.1	127.5
State and local income taxes:
Current state and local income taxes										9.7	(14.7)	17.1
Deferred state and local income taxes										23.8	24.7	25.3
Total state and local income taxes										33.5	10.0	42.4
Foreign income taxes:
Current foreign income taxes										115.3	79.6	83.2
Deferred foreign income taxes										(71.0)	19.5	(39.8)
Total foreign income taxes										44.3	99.1	43.4
Total provision for income taxes	$ 87.9	[1]	$ 65.0	$ 65.3	$ (1.7)	$ 103.2	$ 28.4	$ 62.0	$ (12.4)	$ 216.5	$ 181.2	$ 213.3

[1] The three months ended December 31, 2014 included a tax benefit of $67.6 due to the net reversal of valuation allowances on deferred tax assets in Continental Europe.