Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Beginning Balance				$ (146.0)
Ending Balance	$ (152.0)	$ (148.0)		(152.0)	$ (148.0)
Foreign currency translation adjustments
Beginning Balance	(54.0)	(51.0)	$ (40.0)	(57.0)	(40.0)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(10.0)	(2.0)		(7.0)	(14.0)
Ending Balance	(64.0)	(53.0)		(64.0)	(53.0)
Amortization of pension and post-retirement prior service costs and net loss
Beginning Balance	(91.0)	(99.0)	(84.0)	(93.0)	(84.0)
Effect of adoption of ASU 2018-02	0.0	0.0		0.0	(17.0)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0.0	(0.0)		0.0	0.0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	1.0	1.0		3.0	4.0
Ending Balance	(90.0)	(98.0)		(90.0)	(98.0)
Unrealized gain (loss) on investments
Beginning Balance	3.0	3.0	2.0	3.0	2.0
Effect of adoption of ASU 2018-02	0.0	0.0		0.0	1.0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0.0	0.0		(1.0)	0.0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0.0	0.0		0.0	0.0
Ending Balance	3.0	3.0		3.0	3.0
AOCI Attributable to Parent [Member]
Beginning Balance	(143.0)	(147.0)	(122.0)	(146.0)	(122.0)
Ending Balance	$ (152.0)	$ (148.0)	(135.0)	$ (152.0)	$ (148.0)
Accounting Standards Update 2018-02 [Member]
Effect of adoption of ASU 2018-02			0.0
Accounting Standards Update 2018-02 [Member] | AOCI Attributable to Parent [Member]
Effect of adoption of ASU 2018-02			$ (17.0)