Unit Based Awards (Schedule of Compensation Costs) (Details) - Selling, General and Administrative Expenses [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unit-based compensation expense	$ 351	$ 208	$ 750	$ 387
Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unit-based compensation expense	341	156	652	284
Non-employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unit-based compensation expense	$ 10	$ 52	$ 98	$ 103