Income Taxes (Tables)

12 Months Ended

Sep. 30, 2024

Income Tax Disclosure [Abstract]

Components of Federal and State Income Taxes Included in the Consolidated Statements of Income

The components of federal and state income taxes included in the Consolidated Statements of Income are as follows:

	Year Ended September 30
	2024		2023		2022
	(Thousands)
Current Income Taxes —
Federal	$	6,453	$	11,744	$	—
State	5,899		1,386		12,214
Deferred Income Taxes —
Federal	894		106,801		137,025
State	(3,504)		44,602		(32,610)
Total Income Taxes	$	9,742	$	164,533	$	116,629

Schedule of Income Tax Reconciliation by Applying Federal Income Tax Rate

The following is a reconciliation of this difference:

	Year Ended September 30
	2024		2023		2022
	(Thousands)
U.S. Income Before Income Taxes	$	87,255	$	641,399	$	682,650
Income Tax Expense, Computed at U.S. Federal Statutory Rate of 21%	$	18,324	$	134,694	$	143,357
State Valuation Allowance (1)	—		—		(24,850)
State Income Taxes (2)	1,892		36,331		8,736
Amortization of Excess Deferred Federal Income Taxes	(5,607)		(6,053)		(5,184)
Plant Flow Through Items	(6,135)		(2,856)		(814)
Stock Compensation	1,758		957		820
Federal Tax Credits	(5)		(6)		(5,701)
Miscellaneous	(485)		1,466		265
Total Income Taxes	$	9,742	$	164,533	$	116,629

(1)During fiscal 2022, the valuation allowance recorded against certain state deferred tax assets was removed. See discussion below.

(2)The state income tax expense shown above includes adjustments to the estimated state effective tax rates utilized in the calculation of deferred income taxes, including the Pennsylvania rate change discussed above.

Significant Components of Deferred Tax Liabilities and Assets

Significant components of the Company’s deferred tax liabilities and assets were as follows:

	At September 30
	2024		2023
	(Thousands)
Deferred Tax Liabilities:
Unrealized Hedging Gains	$	22,433	$	3,385
Property, Plant and Equipment	1,134,727		1,178,893
Pension and Other Post-Retirement Benefit Costs	59,877		44,358
Other	13,885		21,470
Total Deferred Tax Liabilities	1,230,922		1,248,106
Deferred Tax Assets:
Tax Loss and Credit Carryforwards	(31,111)		(33,744)
Pension and Other Post-Retirement Benefit Costs	(49,622)		(41,843)
Other	(39,024)		(48,349)
Total Deferred Tax Assets	(119,757)		(123,936)
Total Net Deferred Income Taxes	$	1,111,165	$	1,124,170

Summary of Changes in Valuation Allowances for Deferred Tax Assets

The following is a summary of changes in valuation allowances for deferred tax assets:

	Year Ended September 30
	2024		2023		2022
	(Thousands)
Balance at Beginning of Year	$	—	$	—	$	57,645
Additions	—		—		—
Deductions	—		—		57,645
Balance at End of Year	$	—	$	—	$	—

Summary of Operating Loss and Tax Credit Carryforwards

Tax carryforwards available at September 30, 2024, were as follows:

Jurisdiction	Tax Attribute	Amount (Thousands)		Expires
Pennsylvania	Net Operating Loss	$	438,058	2031-2044