Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2023

Asset Retirement Obligation Disclosure [Abstract]

Schedule of Asset Retirement Obligations [Table Text Block]

AROs consist of the following (in millions):

	As of December 31,
	2023		2022
Trojan decommissioning activities	$	174	$	170
Utility plant	85		86
Non-utility property	27		33
Total asset retirement obligations	286		289
Less: current portion *	14		32
Noncurrent asset retirement obligations	$	272	$	257

*    Current portion of AROs are classified within Accrued expenses and other current liabilities in the consolidated balance sheets.

Schedule of Change in Asset Retirement Obligation [Table Text Block]

The following is a summary of the changes in the Company’s AROs (in millions):

	Years Ended December 31,
	2023		2022		2021
Balance as of beginning of year	$	289	$	269	$	291
Liabilities incurred	2		1		—
Liabilities settled	(25)		(27)		(18)
Accretion expense	11		10		10
Revisions in estimated cash flows	9		36		(14)
Balance as of end of year	$	286	$	289	$	269