Regulation (Tables)

12 Months Ended

Sep. 30, 2023

Regulated Operations [Abstract]

Schedule of Regulatory Liabilities

Significant regulatory assets and liabilities as of September 30, 2023 and 2022 included the following:

	September 30
	2023		2022
	(In thousands)
Regulatory assets:
Pension and postretirement benefit costs	$	20,629	$	31,122
Infrastructure mechanisms (1)	229,996		235,972
Winter Storm Uri incremental costs	32,115		2,109,454
Deferred gas costs	148,297		119,742
Regulatory excess deferred taxes (2)	47,549		47,311
Recoverable loss on reacquired debt	3,238		3,406
Deferred pipeline record collection costs	54,008		36,898
Other	19,096		21,467
	$	554,928	$	2,605,372
Regulatory liabilities:
Regulatory excess deferred taxes (2)	$	384,513	$	545,021
Regulatory cost of removal obligation	582,867		568,307
Deferred gas costs	23,093		28,834
APT annual adjustment mechanism	49,894		31,138
Pension and postretirement benefit costs	215,913		156,857
Other	28,054		23,013
	$	1,284,334	$	1,353,170

(1)Infrastructure mechanisms in Texas, Louisiana and Tennessee allow for the deferral of all eligible expenses associated with capital expenditures incurred pursuant to these rules, including the recording of interest on the deferred expenses until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recovered through base rates.

(2)Regulatory excess deferred taxes represent changes in our net deferred tax liability related to our cost of service ratemaking due to the enactment of the Tax Cuts and Jobs Act of 2017 (the "TCJA") and a Kansas legislative change enacted in fiscal 2020. See Notes 13 and 15 to the consolidated financial statements for further information.

Schedule of Regulatory Assets

Significant regulatory assets and liabilities as of September 30, 2023 and 2022 included the following:

	September 30
	2023		2022
	(In thousands)
Regulatory assets:
Pension and postretirement benefit costs	$	20,629	$	31,122
Infrastructure mechanisms (1)	229,996		235,972
Winter Storm Uri incremental costs	32,115		2,109,454
Deferred gas costs	148,297		119,742
Regulatory excess deferred taxes (2)	47,549		47,311
Recoverable loss on reacquired debt	3,238		3,406
Deferred pipeline record collection costs	54,008		36,898
Other	19,096		21,467
	$	554,928	$	2,605,372
Regulatory liabilities:
Regulatory excess deferred taxes (2)	$	384,513	$	545,021
Regulatory cost of removal obligation	582,867		568,307
Deferred gas costs	23,093		28,834
APT annual adjustment mechanism	49,894		31,138
Pension and postretirement benefit costs	215,913		156,857
Other	28,054		23,013
	$	1,284,334	$	1,353,170

(1)Infrastructure mechanisms in Texas, Louisiana and Tennessee allow for the deferral of all eligible expenses associated with capital expenditures incurred pursuant to these rules, including the recording of interest on the deferred expenses until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recovered through base rates.

(2)Regulatory excess deferred taxes represent changes in our net deferred tax liability related to our cost of service ratemaking due to the enactment of the Tax Cuts and Jobs Act of 2017 (the "TCJA") and a Kansas legislative change enacted in fiscal 2020. See Notes 13 and 15 to the consolidated financial statements for further information.