Reconciliation of Effective Income Tax Rate (Details) - USD ($) $ in Millions		3 Months Ended																12 Months Ended
		Dec. 31, 2017	[2]	Sep. 30, 2017	[2]	Jun. 30, 2017	[2]	Mar. 31, 2017	[2]	Dec. 31, 2016	[2]	Sep. 30, 2016	[2]	Jun. 30, 2016	[2]	Mar. 31, 2016	[2]	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Valuation Allowance [Line Items]
U.S. federal statutory income tax rate																		35.00%	35.00%	35.00%
Income tax provision at U.S. federal statutory rate																		$ 306.6	$ 290.6	$ 266.8
State and local income taxes, net of federal income tax benefit																		23.5	4.3	18.3
Impact of foreign operations, including withholding taxes																		(6.7)	(23.9)	14.7
Change in net valuation allowance	[1]																	1.4	(13.4)	(20.6)
Divestitures																		1.1	9.7	11.9
U.S. federal tax credits																		(1.7)	(44.6)	0.0
Stock Compensation																		(15.3)	(9.0)	0.0
Increase (decrease) in unrecognized tax benefits																		7.0	(22.2)	(6.5)
Net impact of the Tax Act																		(36.0)	0.0	0.0
Statutory tax rate changes																		0.0	11.4	1.4
Other																		2.0	(4.9)	(3.2)
Total provision for income taxes		$ 166.1		$ 42.5		$ 75.4		$ (2.1)		$ 106.1		$ 63.8		$ 43.7		$ (15.6)		$ 281.9	$ 198.0	$ 282.8
Effective income tax rate on operations																		32.20%	23.80%	37.10%

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

[2] The three months ended September 30, 2017 included a tax benefit of $31.2 related to foreign tax credits from distributions of unremitted earnings, which was reversed during the three months ended December 31, 2017 as a result of the enactment of the Tax Cuts and Jobs Act. The three months ended December 31, 2017 included a net tax benefit of $36.0 as a result of the enactment of the Tax Cuts and Jobs Act. The three months ended March 31, 2016 included a tax benefit of $12.2 due to the reversal of valuation allowances. The three months ended June 30, 2016 included a tax benefit of $23.4 related to the conclusion and settlement of a tax examination of previous years. The three months ended December 31, 2016 included a tax benefit of $37.4 for refunds to be claimed on future amended U.S. federal returns.