Other Long-Term Liabilities - Schedule of Other Long-Term Liabilities (Details) - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017
Other Liabilities Noncurrent [Abstract]
Unrecognized tax benefits	[1]	$ 148	$ 127
Long-term income taxes payable	[2]	31	61
Financing obligation, net of current portion	[3]	83	84
Other	[4]	20	21
Total other long term liabilities		$ 282	$ 293

[1] Refer to “Note 11: Income Taxes” for additional information on our unrecognized tax benefits. Amount includes accrued interest related to this liability.

[2] Amount relates to the long-term portion of Transition Tax related to 2017 Tax Act. Refer to “Note 11: Income Taxes,” for additional information.

[3] Refer to “Note 14: Commitments and Contingencies,” for additional information on our corporate headquarters lease and its related financing obligation.

[4] Amounts primarily consist of long-term deferred rent balances related to our operating leases for office space.