Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Net operating loss carryforwards	$ 238.7	$ 160.8
Pension and retiree benefits accruals	33.5	36.3
Inventory	9.4	8.2
Depreciation and fixed assets	11.7	12.9
Intangibles	3.3	2.8
Tax credit carryforwards	10.3	8.8
Equity compensation	16.2	21.5
Other	53.3	76.5
Valuation allowance	(177.1)	(172.1)
Total deferred tax assets	199.3	155.7
Deferred tax liabilities:
Convertible debt discount	247.0	209.2
Inventory	2.4	1.0
Depreciation and fixed assets	25.7	28.3
Intangibles	4.9	7.4
Other	25.6	24.4
Total deferred tax liabilities	305.6	270.3
Net deferred tax assets (liabilities)	$ (106.3)	$ (114.6)