Income Taxes (Details 3) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Deferred tax liability not recognized, undistributed earnings of foreign subsidiaries	$ 28.0
Deferred tax assets:
Net operating loss and capital loss carryforwards	359.0	$ 187.0
Retirement and other employee benefits	67.0	118.0
Unrealized loss on hedging derivatives	6.0	9.0
Intangible asset	5.0	34.0
Other	115.0	140.0
Gross deferred tax assets	552.0	488.0
Valuation allowance	(156.0)	(159.0)
Net deferred tax assets	396.0	329.0
Deferred tax liabilities:
Depreciation and amortization	(256.0)	(329.0)
Deferred Tax Liabilities, Investment in Noncontrolled Affiliates	(1,151.0)	(1,582.0)
Foreign earnings	(28.0)	(28.0)
Unrealized gain on hedging derivatives	0.0	(16.0)
Other	(8.0)	(4.0)
Deferred tax liabilities	1,443.0	1,959.0
Net deferred tax liability	(1,047.0)	(1,630.0)
Unrecognized tax benefits:
Beginning balance	134.0	155.0
Additions for tax positions taken during the current year	0.0	0.0
Additions for tax positions taken during prior years	0.0	2.0
Reductions related to lapsed statutes of limitations	(11.0)	(7.0)
Ending balance	122.0	134.0
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	$ 1.0	$ 16.0