Operating Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	$ 300	$ 1,800
Terminal Facilities
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	800	1,300
Terminal Facilities | Related Party
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	0	247
Related Party Transaction, Expenses from Transactions with Related Party	$ 0	$ 300