Stockholders' Equity (Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Beginning balance			$ 5,111.9
Other comprehensive income (loss), net of tax	$ 50.3	$ (43.9)	112.3	$ 25.9
Accumulated other comprehensive income (loss)	13,724.9		5,111.9		$ 5,111.9
Accumulated other comprehensive income attributable to noncontrolling interest	(4.5)				(11.7)
Ending balance	13,729.4		13,729.4
Foreign Currency Translation
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Beginning balance			(849.8)
Other comprehensive income (loss) before reclassifications, net of tax			(34.7)
Other comprehensive income (loss), net of tax			(34.7)
Accumulated other comprehensive income (loss)	(884.5)		(849.8)		(849.8)
Accumulated other comprehensive income attributable to noncontrolling interest	(0.7)
Ending balance	(885.2)		(885.2)
Hedging Instruments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Beginning balance			(126.9)
Other comprehensive income (loss) before reclassifications, net of tax			74.9
Reclassification adjustment for net losses (gains) included in net income, net of tax			74.3
Other comprehensive income (loss), net of tax			149.2
Accumulated other comprehensive income (loss)	22.3		(126.9)		(126.9)
Ending balance	22.3		22.3
Defined Pension and Other Post-retirement Benefits
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Beginning balance			(80.7)
Other comprehensive income (loss) before reclassifications, net of tax			(4.0)
Reclassification adjustment for net losses (gains) included in net income, net of tax			1.8
Other comprehensive income (loss), net of tax			(2.2)
Accumulated other comprehensive income (loss)	(82.9)		(80.7)		(80.7)
Ending balance	(82.9)		(82.9)
AOCI Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Accumulated other comprehensive income attributable to noncontrolling interest	(0.7)
AOCI Including Portion Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Other comprehensive income (loss), net of tax			112.3
Accumulated other comprehensive income (loss)	(945.1)
Accumulated Other Comprehensive Income (Loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Beginning balance			(1,057.4)
Other comprehensive income (loss) before reclassifications, net of tax			36.2
Reclassification adjustment for net losses (gains) included in net income, net of tax			76.1
Other comprehensive income (loss), net of tax			111.6
Accumulated other comprehensive income (loss)	(945.8)		(1,057.4)		$ (1,057.4)
Ending balance	$ (945.8)		$ (945.8)