Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2021

Asset Retirement Obligation Disclosure [Abstract]

Schedule of Asset Retirement Obligations [Table Text Block]

AROs consist of the following (in millions):

	As of December 31,
	2021		2020
Trojan decommissioning activities	$	139	$	139
Utility plant	95		118
Non-utility property	35		34
Total asset retirement obligations	269		291
Less: current portion *	31		21
Noncurrent asset retirement obligations	$	238	$	270

*    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,
	2021		2020		2019
Balance as of beginning of year	$	291	$	279	$	197
Liabilities incurred	—		3		—
Liabilities settled	(18)		(18)		(9)
Accretion expense	10		10		9
Revisions in estimated cash flows	(14)		17		82
Balance as of end of year	$	269	$	291	$	279