Revenue Recognition - Summary of Changes to Remaining Performance Obligations (Parenthetical) (Detail)	Mar. 31, 2018
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Percentage of remaining performance obligations	100.00%
Saudi Aramco [Member]
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Percentage of remaining performance obligations	48.00%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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