Segments, Geographical Area and Major Customer Information - Reconciliation of Segment Net Assets to Consolidated Total Assets (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting [Abstract]
Segment net assets	$ 3,887	$ 3,355	$ 2,894
Accounts payable and other current liabilities	1,704	1,254
Other current and long-term assets	53	251
Total assets	$ 5,644	$ 4,860