Balance Sheet Components Other Current Assets (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Other Current Assets [Line Items]
Prepaid expenses	$ 53	$ 38
Current deferred income tax asset	43	42
Assets from price risk management activities	18	13
Other	0	1
Other current assets	$ 114	$ 94