Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions	Mar. 31, 2018 USD ($)
Accounting Standards Update 2016-16
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Prepaid taxes written off to accumulated deficit	$ 2.6

Amount of cumulative effect of the change in accounting principle or new accounting pronouncement on retained earnings or other components of equity or net assets in the statement of financial position as of the beginning of the earliest period presented.

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