Shareowners' Deficit - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Beginning balance		$ (90.3)
Unrealized gain on Investment in CyrusOne, net		8.3	$ 0.0
Reclassifications, net		(73.6)
Ending balance		(155.6)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Beginning balance		(157.6)
Unrealized gain on Investment in CyrusOne, net		0.0
Reclassifications, net	[1]	2.8
Ending balance		(154.8)
Available-for-sale Securities [Member]
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Beginning balance		68.1
Unrealized gain on Investment in CyrusOne, net	[2]	8.3
Reclassifications, net	[3]	(76.4)
Ending balance		0.0
Accumulated Translation Adjustment [Member]
Changes in Accumulated Other Comprehensive Loss by Component [Roll Forward]
Beginning balance		(0.8)
Unrealized gain on Investment in CyrusOne, net		0.0
Reclassifications, net		0.0
Ending balance		$ (0.8)

[1] These reclassifications are included in the components of net periodic pension and postretirement benefit costs (see Note 6 for additional details). The components of net periodic pension and postretirement benefit cost are reported within "Cost of services," "Cost of products sold," and "Selling, general and administrative" expenses on the Condensed Consolidated Statements of Operations.

[2] 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.

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