Operating Leases (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	$ 3,800	$ 0	$ 3,800	$ 800
Related Party
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense		0	0	813
Terminal Facilities
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	1,500	500	2,500	1,600
Terminal Facilities | Related Party
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	$ 421	$ 466	$ 1,227	$ 1,397