Balance Sheet Components Other Current Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Accrued employee compensation and benefits	$ 39	$ 60
Accrued taxes payable	32	31
Accrued interest payable	43	27
Accrued dividends payable	31	31
Regulatory liabilities—current	28	31
Other	56	61
Total accrued expenses and other current liabilities	$ 229	$ 241