Pension Plan and Retirement Benefits (Tables)

6 Months Ended

Mar. 31, 2022

Pension and Post-retirement Benefits

Schedule of components of net periodic pension and postretirement benefit cost

	Three Months Ended March 31,								Six Months Ended March 31,
	Pension Benefits				Other Benefits				Pension Benefits				Other Benefits
	2021		2022		2021		2022		2021		2022		2021		2022
Service cost	$	1,407	$	1,182	$	274	$	456	$	2,814	$	2,364	$	548	$	912
Interest cost		1,808		1,923		573		559		3,616		3,846		1,146		1,118
Expected return		(3,978)		(3,561)		—		—		(7,956)		(7,122)		—		—
Amortizations		1,956		51		—		(60)		3,912		102		—		(120)
Net periodic benefit cost	$	1,193	$	(405)	$	847	$	955	$	2,386	$	(810)	$	1,694	$	1,910