Supplemental Balance Sheet Information (Details Textual) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2015	Dec. 31, 2014
Long Lived Assets Held-for-sale [Line Items]
Assets held-for-sale		$ 41	$ 5
Supplemental Balance Sheet Information [Abstract]
Interest accrued on debt		36	$ 45
Gain on sale of surplus property	$ 12
Minimum
Long Lived Assets Held-for-sale [Line Items]
Anticipated gain		6
Maximum
Long Lived Assets Held-for-sale [Line Items]
Anticipated gain		$ 8