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Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
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Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020
Accounting Policies [Abstract] |  |  |  |
Interest bearing amounts held at other financial institutions | $ 38.0 | $ 35.1 | $ 38.0 | $ 35.1
Dilutive effect of common stock issuable upon exercise of options | 423,469 | 121,382 | 420,471 | 143,698
Anti-dilutive shares | 0 | 534,275 | 0 | 418,910

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- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257 + Details
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