Regulatory Assets and Liabilities

3 Months Ended

Dec. 31, 2021

Regulatory Assets and Liabilities Disclosure [Abstract]

Regulatory assets generally represent incurred costs that have been deferred because such costs are probable of future recovery in customer rates. Regulatory liabilities generally represent obligations to make refunds to customers for previous collections for costs that are not likely to be incurred or deferral of gains that will be credited to customers in future periods. Components of regulatory assets and regulatory liabilities are summarized in the table below.


Regulatory Assets and Liabilities
	At December 31, 2021		At September 30, 2021
Current regulatory assets

Unrealized losses on interest rate derivatives	$	109	$	114

Unrealized losses on commodity derivatives	5		3


Fuel cost adjustment receivable	49		79

Total current regulatory assets	163		196

Non-current regulatory assets
Deferred pension costs and other post-retirement benefits costs	3,592		3,668
Non-nuclear decommissioning costs	2,696		2,653

Unrealized losses on interest rate derivatives	1,143		1,122
Nuclear decommissioning costs	218		363

Unrealized losses on commodity derivatives	1		—


Other non-current regulatory assets	143		150
Total non-current regulatory assets	7,793		7,956
Total regulatory assets	$	7,956	$	8,152

Current regulatory liabilities
Fuel cost adjustment tax equivalents	$	137	$	130

Unrealized gains on commodity derivatives	86		210
Total current regulatory liabilities	223		340

Non-current regulatory liabilities

Unrealized gains on commodity derivatives	25		40
Total non-current regulatory liabilities	25		40

Total regulatory liabilities	$	248	$	380