Operating Leases (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	$ 1,100	$ 2,300
Related Party
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	1,085	1,830
Terminal Facilities
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	1,000	1,100
Terminal Facilities | Related Party
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	$ 956	$ 1,027