Balance Sheet Components Schedule of Other Asssets and Other Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Other current assets:
Prepaid Expense, Current	$ 63	$ 54
Margin Deposit Assets	16	16
Assets from price risk management activities	25	20
Other Assets, Current	104	90
Accrued expenses and other current liabilities:
Regulatory Liability, Current	44	36
Accrued employee compensation and benefits	74	66
Accrued interest payable	25	27
Dividends payable	36	34
Taxes Payable, Current	33	34
Other	103	71
Other Liabilities, Current	$ 315	$ 268