Supplemental Financial Information (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Inventories
Finished goods	$ 33		$ 18
Service parts	12		12
Total inventories	45		30
Deferred revenue
Deferred revenue, current	384	$ 395	414
Long-term deferred revenue	102	$ 85	85
Total deferred revenue	$ 486		$ 499

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

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