Equity Equity (Changes in Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31:			$ (964.1)			$ (778.8)	$ (964.1)	$ (778.8)
Other comprehensive income before reclassifications							(134.2)	(170.5)
Amounts reclassified from accumulated other comprehensive income							36.4	38.9
Provision for income taxes							(7.9)	(9.4)
Other comprehensive income (loss)	$ (131.1)	$ 20.6	5.9	$ (15.4)	$ (281.0)	152.5
Balance at June 30:	(1,069.8)			(919.8)			(1,069.8)	(919.8)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31:			(516.8)			(289.2)	(516.8)	(289.2)
Other comprehensive income before reclassifications							(140.4)	(175.2)
Amounts reclassified from accumulated other comprehensive income							0.0	0.0
Provision for income taxes							0.0	0.0
Other comprehensive income (loss)							(140.4)	(175.2)
Balance at June 30:	(657.2)			(464.4)			(657.2)	(464.4)
Accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss)	(130.6)	$ 19.4	5.5	(15.2)	$ (277.9)	152.1	(105.7)	(141.0)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31:			6.7			4.7	6.7	4.7
Other comprehensive income before reclassifications							(0.9)	(0.5)
Amounts reclassified from accumulated other comprehensive income							0.6	0.6
Provision for income taxes							0.5	0.0
Other comprehensive income (loss)							0.2	0.1
Balance at June 30:	6.9			4.8			6.9	4.8
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31:			$ (454.0)			$ (494.3)	(454.0)	(494.3)
Other comprehensive income before reclassifications							7.1	5.2
Amounts reclassified from accumulated other comprehensive income							35.8	38.3
Provision for income taxes							(8.4)	(9.4)
Other comprehensive income (loss)							34.5	34.1
Balance at June 30:	$ (419.5)			$ (460.2)			$ (419.5)	$ (460.2)