Stockholders' Equity (Changes in Accumulated Other Comprehensive Loss by Component) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance			$ 10,003.1	$ 10,945.2
Amounts reclassified from AOCI	$ 17.1	$ 0.4	26.6	6.1
Other comprehensive income, net of tax			51.7	34.5
Foreign currency translation reclassification adjustments, tax	(12.7)	0.9	(17.1)	(14.7)
Ending balance	7,351.5	11,093.3	7,351.5	11,093.3
Total AOCI [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance			(140.1)	(142.1)
AOCI activity before reclassification			25.1	28.4
Amounts reclassified from AOCI			26.6	6.1
Other comprehensive income, net of tax			51.7	34.5
Ending balance	(88.4)	(107.6)	(88.4)	(107.6)
Foreign currency translation adjustments [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance			(61.4)	(65.7)
AOCI activity before reclassification			17.3	13.9
Amounts reclassified from AOCI			26.2	4.7
Other comprehensive income, net of tax			43.5	18.6
Ending balance	(17.9)	(47.1)	(17.9)	(47.1)
Changes in benefit plan net gain (loss) and prior service (cost) credit [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance			(65.3)	(69.3)
AOCI activity before reclassification			0.9	(0.2)
Amounts reclassified from AOCI			0.6	1.4
Other comprehensive income, net of tax			1.5	1.2
Ending balance	(63.8)	(68.1)	(63.8)	(68.1)
Unrealized net gains (losses) on available for sale securities [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance			(13.4)	(7.1)
AOCI activity before reclassification			6.9	14.7
Amounts reclassified from AOCI			(0.2)
Other comprehensive income, net of tax			6.7	14.7
Ending balance	$ (6.7)	$ 7.6	$ (6.7)	$ 7.6