Balance Sheet Components Allowance for Uncollectible accounts activity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance as of beginning of year	$ 16	$ 5	$ 15
Increase in provision	35	15	2
Amounts written off, less recoveries	(25)	(4)	(12)
Balance as of end of year	26	16	$ 5
OPUC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase in provision	$ 29	$ 8