Retirement Plan And Other Post-Retirement Benefits (Tables)

6 Months Ended

Mar. 31, 2021

Retirement Benefits [Abstract]

Components of Net Periodic Benefit Cost

Components of Net Periodic Benefit Cost (in thousands):

	Retirement Plan				Other Post-Retirement Benefits
Three Months Ended March 31,	2021		2020		2021		2020
Service Cost	$	2,466	$	2,330	$	400	$	402
Interest Cost	5,422		7,483		2,326		3,228
Expected Return on Plan Assets	(14,537)		(15,016)		(7,241)		(7,308)
Amortization of Prior Service Cost (Credit)	158		182		(107)		(107)
Amortization of Losses	9,203		9,846		212		134
Net Amortization and Deferral for Regulatory Purposes (Including Volumetric Adjustments) (1)	7,710		5,519		9,451		8,846
Net Periodic Benefit Cost	$	10,422	$	10,344	$	5,041	$	5,195

	Retirement Plan				Other Post-Retirement Benefits
Six Months Ended March 31,	2021		2020		2021		2020
Service Cost	$	4,932	$	4,659	$	801	$	804
Interest Cost	10,843		14,965		4,652		6,457
Expected Return on Plan Assets	(29,074)		(30,032)		(14,482)		(14,616)
Amortization of Prior Service Cost (Credit)	316		365		(214)		(214)
Amortization of Losses	18,407		19,692		424		267
Net Amortization and Deferral for Regulatory Purposes (Including Volumetric Adjustments) (1)	11,422		7,047		16,303		15,094
Net Periodic Benefit Cost	$	16,846	$	16,696	$	7,484	$	7,792

(1)The Company’s policy is to record retirement plan and other post-retirement benefit costs in the Utility segment on a volumetric basis to reflect the fact that the Utility segment experiences higher throughput of natural gas in the winter months and lower throughput of natural gas in the summer months.