Balance Sheet Components Other Current Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Accrued employee compensation and benefits	$ 51	$ 52
Accrued taxes payable	46	25
Accrued interest payable	40	25
Accrued dividends payable	31	30
Regulatory liabilities—current	20	51
Other	60	71
Total accrued expenses and other current liabilities	$ 248	$ 254