Guarantor and Non-Guarantor Financial Statements, Comprehensive Income Statements (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME
Net sales	$ 343.2	$ 371.7
Cost of products sold:
Cost of products sold, excluding depreciation and amortization and other items	262.0	302.3
Inventory Write-down	4.9	0.0
Unrealized (gain) loss on derivative instruments	(4.0)	4.5
Depreciation and amortization	8.7	8.0
Selling, general, administrative, research and development	26.1	22.7
Net periodic postretirement benefit cost relating to Salaried VEBA	0.8	0.6
(Gain) loss on removal of Union VEBA net assets	(0.1)	492.2
Total selling, general, administrative, research and development	26.8	515.5
Total costs and expenses	298.4	830.3
Operating (loss) income	44.8	(458.6)
Other (expense) income:
Interest expense	(3.7)	(9.8)
Other (expense) income, net	0.3	0.4
(Loss) income before income taxes	41.4	(468.0)
Income tax benefit	(15.1)	175.8
(Loss) earnings in equity of subsidiaries	0.0	0.0
Net (loss) income	26.3	(292.2)
Comprehensive (loss) income	27.2	(225.3)
Parent
CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME
Net sales	0.0	0.0
Cost of products sold:
Cost of products sold, excluding depreciation and amortization and other items	0.0	0.0
Inventory Write-down	0.0
Unrealized (gain) loss on derivative instruments	0.0	0.0
Depreciation and amortization	0.0	0.0
Selling, general, administrative, research and development	0.8	1.0
Net periodic postretirement benefit cost relating to Salaried VEBA	0.0	0.0
(Gain) loss on removal of Union VEBA net assets	0.0	0.0
Total selling, general, administrative, research and development	0.8	1.0
Total costs and expenses	0.8	1.0
Operating (loss) income	(0.8)	(1.0)
Other (expense) income:
Interest expense	(4.3)	(9.5)
Other (expense) income, net	0.0	0.0
(Loss) income before income taxes	(5.1)	(10.5)
Income tax benefit	0.0	0.0
(Loss) earnings in equity of subsidiaries	31.4	(281.7)
Net (loss) income	26.3	(292.2)
Comprehensive (loss) income	27.2	(225.3)
Guarantor Subsidiaries
CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME
Net sales	335.7	363.4
Cost of products sold:
Cost of products sold, excluding depreciation and amortization and other items	257.1	296.4
Inventory Write-down	4.9
Unrealized (gain) loss on derivative instruments	(4.0)	4.5
Depreciation and amortization	8.2	7.7
Selling, general, administrative, research and development	23.6	20.7
Net periodic postretirement benefit cost relating to Salaried VEBA	0.8	0.6
(Gain) loss on removal of Union VEBA net assets	(0.1)	492.2
Total selling, general, administrative, research and development	24.3	513.5
Total costs and expenses	290.5	822.1
Operating (loss) income	45.2	(458.7)
Other (expense) income:
Interest expense	0.6	(0.5)
Other (expense) income, net	0.3	0.5
(Loss) income before income taxes	46.1	(458.7)
Income tax benefit	(16.9)	171.9
(Loss) earnings in equity of subsidiaries	0.3	1.1
Net (loss) income	29.5	(285.7)
Comprehensive (loss) income	30.3	(218.9)
Non-Guarantor Subsidiaries
CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME
Net sales	26.4	34.7
Cost of products sold:
Cost of products sold, excluding depreciation and amortization and other items	23.1	31.6
Inventory Write-down	0.0
Unrealized (gain) loss on derivative instruments	0.0	0.0
Depreciation and amortization	0.5	0.3
Selling, general, administrative, research and development	2.2	1.6
Net periodic postretirement benefit cost relating to Salaried VEBA	0.0	0.0
(Gain) loss on removal of Union VEBA net assets	0.0	0.0
Total selling, general, administrative, research and development	2.2	1.6
Total costs and expenses	25.8	33.5
Operating (loss) income	0.6	1.2
Other (expense) income:
Interest expense	0.0	0.0
Other (expense) income, net	0.0	0.1
(Loss) income before income taxes	0.6	1.3
Income tax benefit	(0.2)	0.0
(Loss) earnings in equity of subsidiaries	0.0	0.0
Net (loss) income	0.4	1.3
Comprehensive (loss) income	0.5	1.4
Consolidating Adjustments
CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME
Net sales	(18.9)	(26.4)
Cost of products sold:
Cost of products sold, excluding depreciation and amortization and other items	(18.2)	(25.7)
Inventory Write-down	0.0
Unrealized (gain) loss on derivative instruments	0.0	0.0
Depreciation and amortization	0.0	0.0
Selling, general, administrative, research and development	(0.5)	(0.6)
Net periodic postretirement benefit cost relating to Salaried VEBA	0.0	0.0
(Gain) loss on removal of Union VEBA net assets	0.0	0.0
Total selling, general, administrative, research and development	(0.5)	(0.6)
Total costs and expenses	(18.7)	(26.3)
Operating (loss) income	(0.2)	(0.1)
Other (expense) income:
Interest expense	0.0	0.2
Other (expense) income, net	0.0	(0.2)
(Loss) income before income taxes	(0.2)	(0.1)
Income tax benefit	2.0	3.9
(Loss) earnings in equity of subsidiaries	(31.7)	280.6
Net (loss) income	(29.9)	284.4
Comprehensive (loss) income	$ (30.8)	$ 217.5