Income Taxes (Details 1) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred tax liabilities:
Depreciation, depletion, and amortization	$ 887.6	$ 740.8
Derivatives	12.4	14.5
Convertible debt	96.5	88.4
Total deferred tax liabilities	996.5	843.7
Deferred tax assets:
Workers compensation, pensions, and other benefits	52.4	47.8
Warranties and reserves	15.6	14.4
Equity items	81.5	72.8
Tax loss carryforwards and credits	249.7	234.9
Inventory	17.9	11.1
Accrued liabilities and other	3.9	4.7
Total deferred tax assets	421.0	385.7
Net deferred tax liabilities before valuation allowance	575.5	458.0
Valuation allowance	19.7	19.3
Net deferred tax liabilities before reserve for uncertain tax positions	595.2	477.3
Deferred tax assets included in reserve for uncertain tax positions	(39.4)	(42.6)
Adjusted net deferred tax liabilities	$ 555.8	$ 434.7