CONDENSED CONSOLIDATED STATEMENT OF PARTNERS' CAPITAL - USD ($) shares in Thousands, $ in Thousands	Total	General Partner	Common Stock	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Sep. 30, 2022	$ 257,915	$ (3,656)	$ 277,177	$ (15,606)
Beginning Balance, unit at Sep. 30, 2022		326	36,092
Net income	13,539	$ 122	$ 13,417
Unrealized gain on pension plan obligation	380			380
Tax effect of unrealized gain on pension plan obligation	(97)			(97)
Unrealized gain on captive insurance collateral	355			355
Tax effect of unrealized gain on captive insurance collateral	(74)			(74)
Unrealized loss on interest rate hedges	(377)			(377)
Tax effect of unrealized loss on interest rate hedges	102			102
Distributions	(5,774)	(292)	(5,482)
Retirement of units	(3,596)		$ (3,596)
Retirement of units, shares			(411)
Ending Balance at Dec. 31, 2022	262,373	$ (3,826)	$ 281,516	(15,317)
Ending Balance, Unit at Dec. 31, 2022		326	35,681
Beginning Balance at Sep. 30, 2023	263,724	$ (4,615)	$ 281,862	(13,523)
Beginning Balance, unit at Sep. 30, 2023		326	35,603
Net income	12,979	$ 118	$ 12,861
Unrealized gain on pension plan obligation	319			319
Tax effect of unrealized gain on pension plan obligation	(75)			(75)
Unrealized gain on captive insurance collateral	932			932
Tax effect of unrealized gain on captive insurance collateral	(202)			(202)
Unrealized loss on interest rate hedges	(1,042)			(1,042)
Tax effect of unrealized loss on interest rate hedges	285			285
Distributions	(6,118)	(334)	(5,784)
Retirement of units	(150)		$ (150)
Retirement of units, shares			(13)
Ending Balance at Dec. 31, 2023	$ 270,652	$ (4,831)	$ 288,789	$ (13,306)
Ending Balance, Unit at Dec. 31, 2023		326	35,590