Income Taxes - Valuation Allowances (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of year				$ 40.1				$ 32.4	$ 40.1	$ 32.4	$ 47.4
Expiring tax credits									(0.3)	(0.5)	(1.8)
Acquisitions and dispositions									0.0	(1.0)	(32.7)
Changes in judgment about deferred tax assets(a)									1.5	1.9	(0.2)
Income from continuing operations	$ (3.2)	$ 7.7	$ (13.0)	(0.6)	$ (25.5)	$ 28.8	$ 0.9	(59.0)	(9.1)	(54.8)	66.0
Foreign currency exchange effects									(4.3)	(2.9)	1.0
Income from discontinued operations	(0.4)	$ (0.1)	$ 0.1	$ (2.4)	(21.7)	$ (8.6)	$ 0.7	$ 0.5	(2.8)	(29.1)	(9.2)
Other comprehensive income (loss)									(103.4)	(181.5)	154.6
End of year	$ 45.7				$ 40.1				45.7	40.1	32.4
Valuation Allowance of Deferred Tax Assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Income from continuing operations									8.4	6.3	6.1
Income from discontinued operations									0.0	3.3	12.6
Other comprehensive income (loss)									$ 0.3	$ 0.6	$ 0.0