Income Taxes (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income tax provision	$ 14,260,000	$ (15,890,000)
Effective income tax rate	26.90%
Tax Benefit from United States Short Line Tax Credit, Amount		$ 31,600,000
Effective income tax reconciliation excluding short line tax credit, percentage		26.20%
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