Other Financial Data - Schedule of Other Non-current Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Other Financial Data [Abstract]
Taxes payable	$ 538		$ 529
Deferred revenue	56		49
Leases	156		153
Compensation and benefits	62		67
Other	293		304
Total	1,105	$ 1,099	1,102
Noncurrent portion of transition tax	$ 222		$ 222