Related Party Transactions (Affiliates Earned Commissions and Billed for Reimbursements Pursuant to Operating Agreement (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Related Party Transactions [Abstract]
Cost reimbursements to General Partner	$ 125	$ 49	$ 225	$ 95
Equipment and incentive management fees to General Partner	22	13	43	28
Related party transaction, total	$ 147	$ 62	$ 268	$ 123