Income Taxes (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax liabilities:
Depreciation, depletion, and amortization	$ 668.9	$ 887.6
Derivatives	0	12.4
Accrued liabilities and other	48.3	0
Convertible debt	105.4	96.5
Total deferred tax liabilities	822.6	996.5
Deferred tax assets:
Workers compensation, pensions, and other benefits	61.3	52.4
Warranties and reserves	13.8	15.6
Equity items	33.4	81.5
Tax loss carryforwards and credits	27.5	249.7
Inventory	18.8	17.9
Accrued liabilities and other	0	3.9
Total deferred tax assets	154.8	421.0
Net deferred tax liabilities before valuation allowance	667.8	575.5
Valuation allowance	10.2	19.7
Net deferred tax liabilities before reserve for uncertain tax positions	678.0	595.2
Deferred tax assets included in reserve for uncertain tax positions	(38.6)	(39.4)
Adjusted net deferred tax liabilities	$ 639.4	$ 555.8