Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 0.80
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	800,000	$ 800,000
Tax Credit Carryforward, Valuation Allowance	$ 800,000	$ 800,000
Effective Income Tax Rate Reconciliation, Percent	29.80%	28.20%	17.90%
Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act, Amount	$ 0	$ 0	$ 16,500,000
Deferred Tax Liabilities
Book/tax basis difference due to depreciation	1,017,800,000	901,300,000
Deferred Tax Liabilities, Right of Use Assets	93,800,000	103,900,000
Investments in affiliated companies	26,100,000	38,500,000
Lease accounting (other than leveraged)	33,400,000	31,600,000
Other	2,800,000	0
Total deferred tax liabilities	1,173,900,000	1,075,300,000
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Contingencies	95,900,000	108,600,000
Deferred Tax Assets
Alternative minimum tax credit	0	1,700,000
Federal net operating loss	53,500,000	15,100,000
State net operating loss	38,300,000	31,100,000
Valuation on state net operating loss	(13,900,000)	(12,900,000)
Foreign net operating loss	2,100,000	2,200,000
Accruals not currently deductible for tax purposes	16,000,000.0	19,200,000
Allowance for losses	1,100,000	1,200,000
Pension and post-retirement benefits	16,400,000	16,800,000
Other	1,700,000	3,800,000
Total deferred tax assets	211,100,000	186,800,000
Net deferred tax liabilities	962,800,000	888,500,000
Gross liability for unrecognized tax benefits
Effective Income Tax Rate Reconciliation, Tax Credit, Foreign, Amount	0	$ 0	1,400,000
Tax Cuts and Jobs Act of 2017, Transition Tax for Accumulated Foreign Earnings, Income Tax Expense (Benefit)			$ 23,100,000
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent		30.10%	28.40%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	0	$ 0	$ 9,400,000
Provision for Income Taxes, Equity Method Investment	33,600,000	$ 18,000,000.0	$ 10,800,000
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 2,100,000