v3.26.1
Regulation (Tables)
 6 Months Ended
Mar. 31, 2026
Regulated Operations [Abstract]  
Schedule of Regulatory Assets
Regulatory assets and liabilities as of March 31, 2026 and September 30, 2025 included the following:
March 31,
2026		September 30,
2025
 (In thousands)
Regulatory assets:
Pension and postretirement benefit costs$4,508 $262 
Infrastructure mechanisms (1)
424,630 314,047 
Winter Storm Uri incremental costs1,843 5,841 
Deferred gas costs132,354 140,626 
Regulatory excess deferred taxes (2)
49,093 49,793 
Recoverable loss on reacquired debt2,819 2,903 
Deferred pipeline record collection costs34,911 39,035 
System Safety and Integrity Riders (3)
41,478 43,625 
Other16,869 12,597 
$708,505 $608,729 
Regulatory liabilities:
Regulatory excess deferred taxes (2)
$152,503 $190,274 
Regulatory cost of removal obligation647,575 641,019 
Deferred gas costs11,999 6,879 
APT annual adjustment mechanism128,148 99,393 
Pension and postretirement benefit costs292,213 291,351 
Other45,417 40,732 
$1,277,855 $1,269,648 
(1)Texas, Louisiana, and Tennessee have authorized infrastructure mechanisms that mitigate regulatory lag and allow for the deferral of eligible incurred costs related to qualifying capital expenditures until new rates are implemented. The investment and deferred costs are required to be included in the Company's next rate filing (rate case or annual rate filing) for recovery 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"), a Kansas legislative change enacted in fiscal 2020, and a Louisiana legislative change enacted in fiscal 2025. See Note 12 to the condensed consolidated financial statements for further information.
(3)In our APT and West Texas Divisions and portions of our Mid-Tex Division, the RRC has approved the deferral of certain system safety and integrity costs incurred in excess of a specified benchmark. These costs are eligible for recovery in a future filing after such costs are approved by the RRC.
Schedule of Regulatory Liabilities
Regulatory assets and liabilities as of March 31, 2026 and September 30, 2025 included the following:
March 31,
2026		September 30,
2025
 (In thousands)
Regulatory assets:
Pension and postretirement benefit costs$4,508 $262 
Infrastructure mechanisms (1)
424,630 314,047 
Winter Storm Uri incremental costs1,843 5,841 
Deferred gas costs132,354 140,626 
Regulatory excess deferred taxes (2)
49,093 49,793 
Recoverable loss on reacquired debt2,819 2,903 
Deferred pipeline record collection costs34,911 39,035 
System Safety and Integrity Riders (3)
41,478 43,625 
Other16,869 12,597 
$708,505 $608,729 
Regulatory liabilities:
Regulatory excess deferred taxes (2)
$152,503 $190,274 
Regulatory cost of removal obligation647,575 641,019 
Deferred gas costs11,999 6,879 
APT annual adjustment mechanism128,148 99,393 
Pension and postretirement benefit costs292,213 291,351 
Other45,417 40,732 
$1,277,855 $1,269,648 
(1)Texas, Louisiana, and Tennessee have authorized infrastructure mechanisms that mitigate regulatory lag and allow for the deferral of eligible incurred costs related to qualifying capital expenditures until new rates are implemented. The investment and deferred costs are required to be included in the Company's next rate filing (rate case or annual rate filing) for recovery 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"), a Kansas legislative change enacted in fiscal 2020, and a Louisiana legislative change enacted in fiscal 2025. See Note 12 to the condensed consolidated financial statements for further information.
(3)In our APT and West Texas Divisions and portions of our Mid-Tex Division, the RRC has approved the deferral of certain system safety and integrity costs incurred in excess of a specified benchmark. These costs are eligible for recovery in a future filing after such costs are approved by the RRC.