Balance Sheet Components Other Current Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Regulatory liabilities—current	$ 45	$ 60
Accrued employee compensation and benefits	44	51
Accrued interest payable	40	26
Accrued dividends payable	28	23
Accrued taxes payable	40	22
Other	57	54
Total accrued expenses and other current liabilities	$ 254	$ 236