Common Unit Repurchase and Retirement (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	1 Months Ended	3 Months Ended			12 Months Ended			36 Months Ended		1 Months Ended		3 Months Ended	12 Months Ended
	Feb. 29, 2012	Jun. 30, 2010	Mar. 31, 2012 Plan II [Member]	Dec. 31, 2011 Plan II [Member]	Sep. 30, 2012 Plan II [Member]	Sep. 30, 2011 Plan II [Member]	Sep. 30, 2010 Plan II [Member]	Sep. 30, 2012 Plan II [Member]	Jul. 19, 2010 Plan II [Member]	Sep. 30, 2012 Plan III [Member]	Aug. 31, 2012 Plan III [Member]	Sep. 30, 2012 Plan III [Member]	Sep. 30, 2012 Plan III [Member]	Jul. 31, 2012 Plan III [Member]
Partnerships repurchase units
Total Number of Units Purchased as Part of a Publicly Announced Plan or Program			1,497	2,448	3,945	2,108	1,197	7,250		18	4	22	22
Average Price Paid per Unit	$ 4.94	$ 4.04	$ 4.62	$ 5.17	$ 4.96	$ 5.19	$ 4.44	$ 4.94		$ 4.25	$ 4.26	$ 4.26	$ 4.26
Maximum Number of Units that May Yet Be Purchased Under the Program				1,497		3,945	6,053		7,250	2,978	2,996	2,978	2,978	3,000