Partnership's Repurchase Activities (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	1 Months Ended						3 Months Ended		12 Months Ended
	Dec. 31, 2013		Nov. 30, 2013		Oct. 30, 2013		Dec. 31, 2013		Sep. 30, 2013		Sep. 30, 2012
Capital Unit [Line Items]
Partnership's common units authorized for repurchase in a private transaction	1,150	[1]					1,150	[1]
Maximum Number of Units that May Yet Be Purchased Under the Program Plan III and Private Transaction Beginning Total	6,044						6,044
Plan III Common Units Repurchase Program
Capital Unit [Line Items]
Plan III partnership's common units authorized for repurchase	4,894						4,894
Total Number of Units Purchased		[2]		[2]	250	[2],[3]	250	[2]	3,284	[1],[2]	22	[2]
Average Price Paid per Unit		[4]		[4]	$ 5.20	[3],[4]	$ 5.20	[4]	$ 4.63	[1],[4]	$ 4.26	[4]
Maximum Number of Units that May Yet Be Purchased	2,488		2,488		2,488	[3]	2,488		2,738	[1]	6,022

[1] Fiscal year 2013 common unit repurchases include 1.15 million common units acquired in a private transaction.

[2] Units were repurchased as part of a publicly announced program, except as noted in a private transaction.

[3] October 2013 common unit repurchases were acquired in a private transaction.

[4] Amounts include repurchase costs.