Share-Based Compensation - Additional Information (Detail)	3 Months Ended
Mar. 31, 2017 USD ($)
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unearned compensation expense	$ 3,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Fair Value	$ 0

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.

No definition available.

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