Regulatory Assets and Liabilities (Tables)

12 Months Ended

Dec. 31, 2023

Regulatory Assets and Liabilities Disclosure [Abstract]

Components of regulatory assets:


(Millions of Dollars)	See Note(s)	Remaining Amortization Period	Dec. 31, 2023				Dec. 31, 2022
Regulatory Assets			Current		Noncurrent		Current		Noncurrent
Pension and retiree medical obligations	9	Various	$	2	$	396	$	3	$	367
Net AROs (a)	1, 10	Various	—		236		—		212
Depreciation differences		One to 10 years	16		184		16		187
Recoverable deferred taxes on AFUDC		Plant lives	—		135		—		119
Excess deferred taxes — TCJA	7	Various	—		55		2		54
Environmental remediation costs		Various	—		44		6		26
Conservation programs (b)	1	One to two years	12		33		8		16
Revenue decoupling		Various	—		31		—		—
Gas pipeline inspection costs		One to two years	3		25		—		13
Deferred natural gas, electric, steam energy/fuel costs		One to three years	221		22		312		200
Purchased power contract costs		Term of related contract	4		20		3		16
Grid modernization costs		Two years	15		14		14		22
Property tax		Various	3		7		8		2
Other		Various	28		65		39		43
Total regulatory assets			$	304	$	1,267	$	411	$	1,277

(a)Includes amounts recorded for future recovery of AROs.

(b)Includes costs for conservation programs, as well as incentives allowed in certain jurisdictions.

Regulatory Liabilities

Components of regulatory liabilities:


(Millions of Dollars)	See Note(s)	Remaining Amortization Period	Dec. 31, 2023				Dec. 31, 2022
Regulatory Liabilities			Current		Noncurrent		Current		Noncurrent
Deferred income tax adjustments and TCJA refunds (a)	7	Various	$	2	$	1,260	$	2	$	1,298
Plant removal costs	1, 10	Various	—		769		—		705
Effects of regulation on employee benefit costs (b)		Various	—		234		—		227
Renewable resources and environmental initiatives		Various	—		152		—		141
Revenue decoupling		Various	—		63		—		55
ITC deferrals	1	Various	1		44		1		41
Deferred natural gas, electric, steam energy/fuel costs		Less than one year	34		—		3		—
Conservation programs	1	Less than one year	9		—		19		—
Formula rates		One to two years	8		—		16		—
Other		Various	16		40		18		22
Total regulatory liabilities			$	70	$	2,562	$	59	$	2,489

(a)Includes the revaluation of recoverable/regulated plant accumulated deferred income taxes and revaluation impact of non-plant accumulated deferred income taxes due to the TCJA.

(b)Includes regulatory amortization and certain 2018 TCJA benefits approved by the CPUC to offset the prepaid pension asset.