Changes in Stockholders' Equity (Changes in Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance beginning of period	$ 3,128.7	$ 2,998.1	$ 2,993.5	$ 3,095.3
Net losses (gains) reclassified from accumulated other comprehensive loss	1.1	3.7	8.2	12.5
Other comprehensive (income) loss, net of reclassification adjustments	(61.5)	(49.3)	(38.2)	(223.3)
Balance end of period	3,038.8	2,968.9	3,038.8	2,968.9
Defined Benefit Pension Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance beginning of period			(282.4)
Other comprehensive loss before reclassifications			0.0
Net losses (gains) reclassified from accumulated other comprehensive loss	2.8	2.9	8.8	9.0
Other comprehensive (income) loss, net of reclassification adjustments			8.8
Balance end of period	(273.6)		(273.6)
Deferred Net Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance beginning of period			1.4
Other comprehensive loss before reclassifications			(0.3)
Net losses (gains) reclassified from accumulated other comprehensive loss			(0.6)
Other comprehensive (income) loss, net of reclassification adjustments			(0.9)
Balance end of period	0.5		0.5
Cumulative Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance beginning of period			(1,274.4)
Other comprehensive loss before reclassifications			(47.6)
Net losses (gains) reclassified from accumulated other comprehensive loss			0.0
Other comprehensive (income) loss, net of reclassification adjustments			(47.6)
Balance end of period	(1,322.0)		(1,322.0)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance beginning of period	(1,534.3)	(1,533.5)	(1,555.4)	(1,361.6)
Other comprehensive loss before reclassifications			(47.9)
Net losses (gains) reclassified from accumulated other comprehensive loss			8.2
Other comprehensive (income) loss, net of reclassification adjustments			(39.7)
Balance end of period	$ (1,595.1)	$ (1,581.9)	$ (1,595.1)	$ (1,581.9)

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.

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