Regulation (Tables)

6 Months Ended

Mar. 31, 2024

Regulated Operations [Abstract]

Schedule of Regulatory Assets

Regulatory assets and liabilities as of March 31, 2024 and September 30, 2023 included the following:

	March 31, 2024		September 30, 2023
	(In thousands)
Regulatory assets:
Pension and postretirement benefit costs	$	16,174	$	20,629
Infrastructure mechanisms (1)	210,795		229,996
Winter Storm Uri incremental costs	15,510		32,115
Deferred gas costs	25,928		148,297
Regulatory excess deferred taxes (2)	51,654		47,549
Recoverable loss on reacquired debt	3,154		3,238
Deferred pipeline record collection costs	66,535		54,008
Other	15,618		19,096
	$	405,368	$	554,928
Regulatory liabilities:
Regulatory excess deferred taxes (2)	$	315,020	$	384,513
Regulatory cost of removal obligation	594,815		582,867
Deferred gas costs	57,680		23,093
APT annual adjustment mechanism	40,233		49,894
Pension and postretirement benefit costs	205,718		215,913
Other	35,315		28,054
	$	1,248,781	$	1,284,334

(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 deferred expenses until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recoverable 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 Tax Cuts and Jobs Act of 2017 (the "TCJA") and a Kansas legislative change enacted in fiscal 2020. See Note 12 to the condensed consolidated financial statements for further information.

Schedule of Regulatory Liabilities

Regulatory assets and liabilities as of March 31, 2024 and September 30, 2023 included the following:

	March 31, 2024		September 30, 2023
	(In thousands)
Regulatory assets:
Pension and postretirement benefit costs	$	16,174	$	20,629
Infrastructure mechanisms (1)	210,795		229,996
Winter Storm Uri incremental costs	15,510		32,115
Deferred gas costs	25,928		148,297
Regulatory excess deferred taxes (2)	51,654		47,549
Recoverable loss on reacquired debt	3,154		3,238
Deferred pipeline record collection costs	66,535		54,008
Other	15,618		19,096
	$	405,368	$	554,928
Regulatory liabilities:
Regulatory excess deferred taxes (2)	$	315,020	$	384,513
Regulatory cost of removal obligation	594,815		582,867
Deferred gas costs	57,680		23,093
APT annual adjustment mechanism	40,233		49,894
Pension and postretirement benefit costs	205,718		215,913
Other	35,315		28,054
	$	1,248,781	$	1,284,334

(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 deferred expenses until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recoverable 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 Tax Cuts and Jobs Act of 2017 (the "TCJA") and a Kansas legislative change enacted in fiscal 2020. See Note 12 to the condensed consolidated financial statements for further information.