Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions		3 Months Ended	9 Months Ended
Jul. 12, 2019	Sep. 30, 2019	Sep. 30, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Special cash dividend paid	$ 20,000,000		$ 20,000,000
Dividend payable date	Sep. 05, 2019		Sep. 05, 2019
Dividend payable, date of record	Aug. 28, 2019		Aug. 28, 2019
Incremental compensation expense			$ 0
Additional compensation expense			$ 0
Weighted-average grant date fair value per share of stock options		$ 3.53	$ 3.53
Stock Incentive Plan 2011 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock available for grant		1.2	1.2

Date the declared dividend will be paid, in CCYY-MM-DD format.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
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Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
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Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

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Amount of additional cost recognized for award under share-based payment arrangement from occurrence of event accelerating recognition of cost.

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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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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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An excess of the fair value of the modified award over the fair value of the award immediately before the modification.

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