Income Taxes (Details 1) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Deferred tax liabilities:
Depreciation, depletion, and amortization	$ 740.8	$ 667.3
Derivatives	14.5
Convertible debt	88.4	80.9
Total deferred tax liabilities	843.7	748.2
Deferred tax assets:
Workers compensation, pensions, and other benefits	47.8	44.7
Warranties and reserves	14.4	17.5
Equity items	72.8	56.4
Tax loss carryforwards and credits	234.9	224.3
Inventory	11.1	7.6
Accrued liabilities and other	4.7	1.6
Total deferred tax assets	385.7	352.1
Net deferred tax liabilities before valuation allowance	458.0	396.1
Valuation allowance	19.3	19.9
Net deferred tax liabilities before reserve for uncertain tax positions	477.3	416.0
Deferred tax assets included in reserve for uncertain tax positions	(42.6)	(25.0)
Adjusted net deferred tax liabilities	$ 434.7	$ 391.0