Income Taxes (Details) € in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2017	Mar. 31, 2017 EUR (€)	Mar. 31, 2017 USD ($)
Income Tax Expense (Benefit)	$ (15,890,000)	$ 21,928,000
Tax Benefit from United States Short Line Tax Credit, Amount	$ 31,600,000
Effective income tax rate excluding short line tax credit, percentage	26.20%
Effective income tax rate		44.60%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%		35.00%
Tax credits percentage of qualified maintenance expenditures to reduce federal income tax	50.00%
Tax credit limitation per mile on maintenance expenditures to reduce federal income tax	$ 3,500
U.K./European Operations [Member]
Income Tax Expense (Benefit)	$ 2,774,000	$ (1,007,000)
ERS Railways [Member] | U.K./European Operations [Member]
Valuation allowance				€ 1.6	$ 1,700,000