Operating Leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	$ 800	$ 2,300	$ 1,900	$ 4,600
related party payment for terminal purchase	4,875	2,825	4,875	2,825
Related Party
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	799	1,817	1,884	3,646
Terminal Facilities
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	1,000	1,000	2,100	2,100
Terminal Facilities | Related Party
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	$ 963	$ 977	$ 1,900	$ 2,000