Income Taxes (Tables)

12 Months Ended

Sep. 30, 2025

Schedule of Effective Income Tax Rate Reconciliation

Reconciliations of the provision for income taxes computed at the statutory rate of 21 percent to the reported provisions for income taxes from continuing operations for 2025, 2024, and 2023 are set forth below:


	2025				2024				2023
	(In thousands)		%		(In thousands)		%		(In thousands)		%


U.S federal statutory tax rate	$	310,387	21.0	%	$	259,513	21.0	%	$	209,925	21.0	%
State and local income taxes, net of federal income tax effect (1)	24,254		1.6	%	27,367		2.2	%	19,853		2.0	%
Changes in valuation allowances	—		—	%	1,106		0.1	%	—		—	%


Changes in unrecognized tax benefits	2,004		0.1	%	926		0.1	%	5,302		0.5	%
Nontaxable or nondeductible items	741		0.1	%	2,464		0.2	%	1,000		0.1	%
Amortization of excess deferred taxes	(60,727)		(4.1)	%	(100,270)		(8.1)	%	(123,953)		(12.4)	%
Other, net	2,621		0.2	%	1,775		0.1	%	1,652		0.2	%
Income tax expense	$	279,280	18.9	%	$	192,881	15.6	%	$	113,779	11.4	%

(1) The states that contribute to the majority (greater than 50%) of the tax effect in this category include Texas and Louisiana.

Schedule of Deferred Tax Assets and Liabilities

The tax effect of temporary differences that gave rise to significant components of the deferred tax liabilities and deferred tax assets at September 30, 2025 and 2024 are presented below:


	2025		2024
	(In thousands)
Deferred tax assets:
Employee benefit plans	$	34,202	$	41,184

Net operating loss carryforwards	473,642		484,816
Charitable and other credit carryforwards	14,200		12,301
Regulatory excess deferred tax	31,387		46,330
Lease asset	72,973		63,747
Other	31,145		34,934
Total deferred tax assets	657,549		683,312
Valuation allowance	(1,365)		(1,457)
Net deferred tax assets	656,184		681,855
Deferred tax liabilities:
Difference in net book value and net tax value of assets	(3,200,535)		(2,914,854)

Gas cost adjustments	(43,819)		(49,443)

Winter Storm Uri regulatory asset	(17,993)		(20,846)
Lease liability	(66,831)		(57,177)
Rate deferral adjustment	(64,640)		(50,571)
Interest rate agreements	(135,640)		(134,536)
Other	(45,073)		(47,770)
Total deferred tax liabilities	(3,574,531)		(3,275,197)
Net deferred tax liabilities	$	(2,918,347)	$	(2,593,342)

Schedule of Unrecognized Tax Benefits

The following table reconciles the beginning and ending balance of our unrecognized tax benefits:


	2025		2024		2023
	(In thousands)
Unrecognized tax benefits - beginning balance	$	57,797	$	58,638	$	52,683
Decrease resulting from prior period tax positions	(1,759)		(2,867)		(631)
Decrease resulting from a lapse in statute of limitations	(5,699)		(6,188)		—
Increase resulting from current period tax positions	9,993		8,214		6,586
Unrecognized tax benefits - ending balance	60,332		57,797		58,638
Less: deferred federal and state income tax benefits	(12,670)		(12,137)		(12,314)
Total unrecognized tax benefits that, if recognized, would impact the effective income tax rate as of the end of the year (1)	$	47,662	$	45,660	$	46,324

(1) As of September 30, 2025, there is an anticipated $43.3 million regulatory offset and associated impact to tax expense to be recorded upon recognition of unrecognized tax benefits.