Accumulated Other Comprehensive Income (Loss) by Component (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 2,790.9		$ 2,718.3
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	0.0	$ (0.9)
Other Comprehensive Income (Loss) after tax expense	13.8	(109.1)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(35.8)	(62.5)	(35.8)	$ (63.4)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0.0	0.9
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0.0	0.0
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent		0.9
Reclassification from AOCI, Current Period, Tax	0.0	0.0
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	0.0	0.0
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(286.7)	(245.9)	(300.5)	(136.8)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	13.8	(109.1)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0.0	0.0
Other Comprehensive Income (Loss) after tax expense		(109.1)
Reclassification from AOCI, Current Period, Tax	0.0	0.0
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	0.0	0.0
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(322.5)	(308.4)	$ (336.3)	$ (200.2)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	13.8	(108.2)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0.0	0.0
Other Comprehensive Income (Loss) after tax expense	13.8
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	13.8	(108.2)
Reclassification from AOCI, Current Period, Tax	0.0	0.0
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	$ 0.0	$ 0.0