Partnership's Repurchase Activities (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2013		Jun. 30, 2014		Sep. 30, 2013		Sep. 30, 2012		Mar. 31, 2014
Capital Unit [Line Items]
Partnership's common units authorized for repurchase			6,044
Private Transaction
Capital Unit [Line Items]
Partnership's common units authorized for repurchase			1,150	[1]	1,150
Plan III Common Units Repurchase Program
Capital Unit [Line Items]
Partnership's common units authorized for repurchase			4,894
Total Number of Units Purchased	250	[2],[3]	250	[2]	3,284	[1],[2]	22	[2]
Average Price Paid per Unit	$ 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	[3]	2,488		2,738	[1]	6,022		2,488

[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] First quarter fiscal year 2014 common unit repurchases were acquired in a private transaction.

[4] Amounts include repurchase costs.