Reconciliation of Effective Income Tax Rate (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. federal statutory income tax rate										21.00%	35.00%	35.00%
Income tax provision at U.S. federal statutory rate										$ 176.0	$ 294.3	$ 289.0
State and local income taxes, net of federal income tax benefit										23.8	23.5	4.3
Impact of foreign operations, including withholding taxes										50.7	(6.7)	(23.9)
U.S. tax incentives										(17.5)	(1.3)	(1.3)
Change in net valuation allowance	[1]									(16.9)	1.4	(13.4)
Divestitures										11.7	1.1	9.7
U.S. federal tax credits										(48.1)	(0.4)	(44.6)
Stock compensation										(6.8)	(15.3)	(9.0)
Change in unrecognized tax benefits										8.4	7.0	(21.8)
Net impact of the Tax Act										13.4	(36.0)	0.0
Statutory tax rate changes										0.0	0.0	11.4
Other										4.5	3.7	(3.5)
Provision for income taxes		$ 62.2	$ 60.7	$ 63.6	$ 12.7	$ 135.1	$ 54.9	$ 81.6	$ (0.3)	$ 199.2	$ 271.3	$ 196.9
Effective income tax rate on operations										23.80%	32.30%	23.80%

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