Other Financial Information (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid expenses	$ 57	$ 42
Contract acquisition costs	52	0
Contract assets	155	49
Other	14	7
Total other current assets	$ 278	$ 98

Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer; classified as current.

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Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as current.

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Amount of current assets classified as other.

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Amount of other miscellaneous assets expected to be realized or consumed within one year or operating cycle, if longer.

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Amount of asset related to consideration paid in advance for costs that provide economic benefits within a future period of one year or the normal operating cycle, if longer.

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