Income Taxes (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Deferred Tax Liabilities
Book/tax basis difference due to depreciation	$ 756.2	$ 704.4
Leveraged leases	62.7	61.8
Investments in affiliated companies	82.4	84.1
Lease accounting (other than leveraged)	13.7	13.9
Other	2.9	1.7
Total deferred tax liabilities	917.9	865.9
Deferred Tax Assets
Alternative minimum tax credit	8.9	11.5
Federal net operating loss	38.1	14.8
Foreign tax credits	13.9	16.9
Valuation on foreign tax credit	(13.9)	(16.9)
State net operating loss	31.1	28.2
Valuation on state net operating loss	(15.8)	(15.8)
Foreign tax net operating loss	7.3	4.7
Accruals not currently deductible for tax purposes	21.8	20.9
Allowance for losses	5.4	3.9
Pension and post-retirement benefits	40.7	31.4
Other	14.5	15.7
Total deferred tax assets	152.0	115.3
Net deferred tax liabilities	765.9	750.6
Gross liability for unrecognized tax benefits
Beginning balance	42.7	54.8
Additions to positions for prior years, including interest		2.6
Reductions due to resolution of audit issues	(21.9)	(14.7)
Ending balance	$ 20.8	$ 42.7