Pension Plans - Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	$ 68,875	$ 67,581
Government
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	27,322	20,430
Corporate Investment Grade
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	1,632	2,038
Large Capitalization Stocks
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	20,864	22,379
Commodity Option
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	4,977	599
Insurance Company Funds
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	7,102	6,823
Options
Fair Value of Plan Assets [Line Items]
Fair value of plan assets		1,430
Cash
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	6,978	13,882
Level 1
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	61,773	60,758
Level 1 | Government
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	27,322	20,430
Level 1 | Corporate Investment Grade
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	1,632	2,038
Level 1 | Large Capitalization Stocks
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	20,864	22,379
Level 1 | Commodity Option
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	4,977	599
Level 1 | Insurance Company Funds
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	0	0
Level 1 | Options
Fair Value of Plan Assets [Line Items]
Fair value of plan assets		1,430
Level 1 | Cash
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	6,978	13,882
Level 2
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	7,102	6,823
Level 2 | Government
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	0	0
Level 2 | Corporate Investment Grade
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	0	0
Level 2 | Large Capitalization Stocks
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	0	0
Level 2 | Commodity Option
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	0	0
Level 2 | Insurance Company Funds
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	7,102	6,823
Level 2 | Options
Fair Value of Plan Assets [Line Items]
Fair value of plan assets		0
Level 2 | Cash
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	0	0
Level 3
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	0	0
Level 3 | Government
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	0	0
Level 3 | Corporate Investment Grade
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	0	0
Level 3 | Large Capitalization Stocks
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	0	0
Level 3 | Commodity Option
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	0	0
Level 3 | Insurance Company Funds
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	0	0
Level 3 | Options
Fair Value of Plan Assets [Line Items]
Fair value of plan assets		0
Level 3 | Cash
Fair Value of Plan Assets [Line Items]
Fair value of plan assets	$ 0	$ 0