Consolidated Statements of Partners' Capital (USD $) In Thousands, unless otherwise specified	Total	General Partner [Member]	Common Unitholders [Member]	Subordinated Unitholder [Member]	Accumulated Other Comprehensive Income [Member]
Beginning balance at Dec. 31, 2011	$ 188,644	$ 3,515	$ 111,989	$ 72,238	$ 902
Partners' capital rollforward
Net income	11,432	229	6,648	4,555	0
Distributions ($1.1625 per unit)	(18,429)	(369)	(10,768)	(7,292)	0
Equity compensation	1,313	0	1,313	0	0
Other comprehensive income (loss)	112	0	0	0	112
Ending balance at Sep. 30, 2012	$ 183,072	$ 3,375	$ 109,182	$ 69,501	$ 1,014