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Equity and Stock-based Compensation - Employee Stock Purchase Plan - Additional information (Detail) - 2014 ESPP [Member] - shares | 1 Months Ended | 12 Months Ended
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Sep. 30, 2014 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Purchase of common stock shares at discount | 15.00% |  |  |
Percentage of fair value exercise price grant date | 85.00% |  |  |
Number of common stock reserved for issuance | 1,600,000 |  |  |
Common stock reserved for future issuance, Description |  | The Company has reserved 1,600,000 shares of its common stock for issuance under the 2014 ESPP and shares reserved for issuance increases January 1 of each year commencing January 1, 2016 by the lesser of (i) a number of shares equal to 1% of the total number of outstanding shares of common stock on December 31 immediately prior to the date of increase; (ii) 1,200,000 shares or (iii) such number of shares as may be determined by the board of directors. |  |
Percentage of common stock reserved for future issuance | 1.00% |  |  |
Increase in number of shares of common stock reserved for future issuance, shares | 1,200,000 |  |  |
Shares purchased by employees |  | 135,115 | 230,317 | 250,834

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- Definition Discount rate from fair value on purchase date that participants pay for shares. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
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- Definition Sets forth the nature of any other increase or decrease in the number of shares reserved for issuance under the option plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
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- Definition The increase or decrease in number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding, including vested options. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
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