Other Financial Data - Schedule of Other Current Assets (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Other Financial Data [Abstract]
Taxes receivable	$ 114	$ 100
Prepaid expenses	126	102
Receivables from the Divested Business	28	0
Other	21	45
Total other current assets	$ 289	$ 247