Joint Venture and Consortium Arrangements - Summarized Balance Sheet Information for Consolidated Joint Venture (Detail) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Current assets	$ 104	$ 102
Non-current assets	14	15
Total assets	118	117
Current liabilities	$ 145	$ 138

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Amount of consolidated variable interest entity's (VIE) assets, classified as current.

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