Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2019

Asset Retirement Obligation Disclosure [Abstract]

Schedule of Asset Retirement Obligations [Table Text Block]

AROs consist of the following (in millions):

	As of December 31,
	2019		2018
Trojan decommissioning activities	$	137	$	68
Utility plant	126		112
Non-utility property	16		17
Total asset retirement obligations	279		197
Less: current portion *	16		—
Noncurrent asset retirement obligations	$	263	$	197

*

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,
	2019			2018			2017
Balance as of beginning of year	$	197		$	167		$	161
Liabilities incurred	—			—			2
Liabilities settled	(9		)	(5		)	(3		)
Accretion expense	9			8			7
Revisions in estimated cash flows	82			27			—
Balance as of end of year	$	279		$	197		$	167