Income Taxes (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards		$ 0.80
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	$ 200,000	800,000	$ 200,000
Tax Credit Carryforward, Valuation Allowance	200,000	$ 800,000	$ 200,000
Effective Income Tax Rate Reconciliation, Percent		26.40%	17.50%	(113.70%)
Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act, Amount		$ 0	$ 16,500,000	$ 315,900,000
Deferred Tax Liabilities
Book/tax basis difference due to depreciation	890,700,000	930,700,000	890,700,000
Deferred Tax Liabilities, Right of Use Assets		103,900,000
Investments in affiliated companies	36,200,000	37,300,000	36,200,000
Lease accounting (other than leveraged)	12,200,000	39,800,000	12,200,000
Other	1,900,000	3,200,000	1,900,000
Total deferred tax liabilities	941,000,000.0	1,114,900,000	941,000,000.0
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Contingencies		108,600,000
Deferred Tax Assets
Alternative minimum tax credit	3,400,000	1,700,000	3,400,000
Federal net operating loss	0	15,100,000	0
State net operating loss	26,400,000	31,100,000	26,400,000
Valuation on state net operating loss	(12,600,000)	(12,900,000)	(12,600,000)
Foreign net operating loss	2,100,000	2,200,000	2,100,000
Deferred Tax Assets, Valuation Allowance	(300,000)	0	(300,000)
Accruals not currently deductible for tax purposes	24,800,000	23,200,000	24,800,000
Allowance for losses	1,100,000	1,200,000	1,100,000
Pension and post-retirement benefits	17,800,000	16,800,000	17,800,000
Other	500,000	3,600,000	500,000
Total deferred tax assets	63,200,000	190,600,000	63,200,000
Net deferred tax liabilities	877,800,000	924,300,000	877,800,000
Gross liability for unrecognized tax benefits
Effective Income Tax Rate Reconciliation, Tax Credit, Foreign, Amount		$ 0	1,400,000	0
Tax Cuts and Jobs Act, Change in Tax Rate, Income Tax Expense (Benefit)				371,400,000
Tax Cuts and Jobs Act of 2017, Change in Tax Rate, Deferred Tax Liability, Income Tax (Expense) Benefit				5,000,000.0
Tax Cuts and Jobs Act of 2017, Transition Tax for Accumulated Foreign Earnings, Income Tax Expense (Benefit)			$ 23,100,000	$ 57,200,000
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent		28.00%	26.70%	31.20%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	$ 17,900,000	$ 0	$ 9,400,000	$ (371,400,000)
Provision for Income Taxes, Equity Method Investment		18,000,000.0	$ 10,800,000	$ 12,000,000.0
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards		2,200,000
Gross liability for unrecognized tax benefits
Ending balance		$ 1,600,000