Acquisiitions (Proforma Financial Results - 2014 Acquisition And 2013 East Texas Acquisition) (Details) (2014 Acquisition And 2013 East Texas Acquisition [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total revenues, Proforma	$ 123,741	$ 121,020
Operating income, Proforma	26,646	22,551
Net income (loss), Proforma	$ (14,251)	$ (5,136)
Limited Partners - Public And Affiliated Common Units [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Unitholders' (basic and diluted) (in dollars per unit), Proforma	$ (2.85)	$ (0.28)