Regulatory Assets and Liabilities Regulatory Assets and Liabilities (Tables)

12 Months Ended

Sep. 30, 2025

Regulatory Assets and Liabilities Disclosure [Abstract]

Regulatory Assets and Liabilities

Components of regulatory assets and regulatory liabilities are summarized in the table below. 

Regulatory Assets and Liabilities  At September 30 (in millions)
	2025		2024
Current regulatory assets
Unrealized losses on commodity contract derivatives	$	59	$	102
Unrealized losses on interest rate derivatives	57		54
Fuel cost adjustment receivable	—		35
Other current regulatory assets	11		—
Total current regulatory assets	127		191
Non-current regulatory assets
Non-nuclear decommissioning costs	5,563		6,187
Retirement benefit plans deferred costs	1,531		1,979
Unrealized losses on interest rate derivatives	316		447
Environmental compliance and remediation costs	308		215
Nuclear decommissioning costs	149		362
Unrealized losses on commodity contract derivatives	12		64
Other non-current regulatory assets	168		154
Total non-current regulatory assets	8,047		9,408
Total regulatory assets	$	8,174	$	9,599
Current regulatory liabilities
Fuel cost adjustment tax equivalents	$	203	$	169
Unrealized gains on commodity contract derivatives	14		5
Fuel cost adjustment payable	11		—
Total current regulatory liabilities	228		174
Non-current regulatory liabilities
Retirement benefit plans deferred credits	131		81
Unrealized gains on commodity contract derivatives	10		2
Total non-current regulatory liabilities	141		83
Total regulatory liabilities	$	369	$	257