Shareowners' Deficit Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Beginning Balance		$ (90.3)		$ (171.0)
Remeasurement of benefit obligations		2.8		6.6		$ (6.6)
Reclassifications, net		(62.5)		6.1
Unrealized gain on Investment in CyrusOne, net		8.3		68.1		0.0
Foreign currency gain (loss)		0.2		(0.1)		(0.4)
Reclassification adjustment to accumulated deficit for stranded other comprehensive taxes arising from tax reform		0.0
Ending Balance		(173.7)		(90.3)		(171.0)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Beginning Balance		(157.6)		(170.3)
Remeasurement of benefit obligations		2.8		6.6
Reclassifications, net	[1]	13.9		6.1
Unrealized gain on Investment in CyrusOne, net		0.0		0.0
Foreign currency gain (loss)		0.0		0.0
Reclassification adjustment to accumulated deficit for stranded other comprehensive taxes arising from tax reform	[2]	(32.2)
Ending Balance		(173.1)		(157.6)		(170.3)
Accumulated Net Investment Gain (Loss) Attributable to Parent
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Beginning Balance		68.1		0.0
Remeasurement of benefit obligations		0.0		0.0
Reclassifications, net		(76.4)	[3]	0.0
Unrealized gain on Investment in CyrusOne, net		8.3	[4]	68.1	[5]
Foreign currency gain (loss)		0.0		0.0
Reclassification adjustment to accumulated deficit for stranded other comprehensive taxes arising from tax reform		0.0
Ending Balance		0.0		68.1		0.0
Accumulated Foreign Currency Adjustment Attributable to Parent
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Beginning Balance		(0.8)		(0.7)
Remeasurement of benefit obligations		0.0		0.0
Reclassifications, net		0.0		0.0
Unrealized gain on Investment in CyrusOne, net		0.0		0.0
Foreign currency gain (loss)		0.2		(0.1)
Reclassification adjustment to accumulated deficit for stranded other comprehensive taxes arising from tax reform		0.0
Ending Balance		$ (0.6)		$ (0.8)		$ (0.7)

[1] These reclassifications are included in the components of net period pension and postretirement benefit costs (see Note 10 for additional details). The components of net period pension and postretirement benefit cost are reported within "Cost of services", "Cost of products sold", and "Selling, general and administrative" expenses on the Consolidated Statements of Operations, with the exception of pension settlement charges, which are reported within "Other" on the Consolidated Statements of Operations.

[2] This provisional reclassification adjustment resulted from a change in the corporate tax rate arising from tax legislation enacted in December 2017, commonly referred to as the Tax Cuts and Jobs Act (the "Tax Act"). In February 2018, the FASB issued ASU 2018-02 which allows entities to make a one-time reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from newly enacted corporate tax rates. The Company early adopted the guidance effective December 31, 2017. The amount of the reclassification is calculated on the basis of the difference between the historical and newly enacted tax rates on deferred taxes related to our pension and postretirement benefit plans.

[3] These reclassifications are reported within "Gain on sale of CyrusOne investment" on the Consolidated Statements of Operations.

[4] The unrealized gain on Investment in CyrusOne, net of tax, represents changes in the fair value of CyrusOne shares of common stock owned by the Company during the period, before any subsequent sales of those shares.

[5] The unrealized gain on the investment in CyrusOne was recorded in 2016 as the investment is no longer accounted for using the equity-method and is recorded as an available-for-sale security on the Consolidated Balance Sheets at fair value.