CONDENSED CONSOLIDATED STATEMENTS OF PARTNERS' CAPITAL - USD ($) shares in Thousands, $ in Thousands		Total	General Partner	Common Stock	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Sep. 30, 2013		$ 259,281	$ 3	$ 282,289	$ (23,011)
Beginning Balance, unit at Sep. 30, 2013			326	57,718
Net income		36,084	$ 203	$ 35,881
Unrealized gain (loss) on pension plan obligation	[1]	(1,070)			(1,070)
Tax effect of unrealized gain (loss) on pension plan obligation		463			463
Distributions	[2]	(19,850)	(311)	$ (19,539)
Retirement of units, shares	[3]			(313)
Retirement of units	[3]	(1,663)		$ (1,663)
Ending Balance at Sep. 30, 2014		273,245	$ (105)	$ 296,968	(23,618)
Ending Balance, Unit at Sep. 30, 2014			326	57,405
Net income		37,556	$ 212	$ 37,344
Unrealized gain (loss) on pension plan obligation	[1]	1,827			1,827
Tax effect of unrealized gain (loss) on pension plan obligation		(753)			(753)
Distributions	[2]	(21,298)	(390)	$ (20,908)
Retirement of units, shares	[3]			(123)
Retirement of units	[3]	(691)		$ (691)
Ending Balance at Sep. 30, 2015		289,886	$ (283)	$ 312,713	(22,544)
Ending Balance, Unit at Sep. 30, 2015			326	57,282
Net income		44,934	$ 252	$ 44,682
Unrealized gain (loss) on pension plan obligation	[1]	3,067			3,067
Tax effect of unrealized gain (loss) on pension plan obligation		(1,285)			(1,285)
Distributions	[2]	(23,092)	(485)	$ (22,607)
Retirement of units, shares	[3]			(1,395)
Retirement of units	[3]	(12,017)		$ (12,017)
Ending Balance at Sep. 30, 2016		$ 301,493	$ (516)	$ 322,771	$ (20,762)
Ending Balance, Unit at Sep. 30, 2016			326	55,887

[1] These items are included in the computation of net periodic pension cost. See Note 12 - Employee Benefit Plans.

[2] See Note 3 - Quarterly Distributions of Available Cash.

[3] See Note 4 - Common Unit Repurchase Plans and Retirement.