Other Financial Data - Schedule of Other Current Assets (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Other Financial Data [Abstract]
Taxes receivable	$ 94	$ 99
Deferred tax assets	232	212
Prepaid expenses	130	164
Deferred project costs	92	102
Other	18	25
Total Other Current Assets	$ 566	$ 602