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Stockholder's/Shareholder's Equity - Additional Information (Detail) - USD ($) | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Jul. 31, 2015 | Jul. 31, 2014 | Nov. 30, 2004 | Nov. 30, 2003
Stockholders Equity [Line Items] |  |  |  |  |  |  |
Stock repurchased during period | 2,951,243 | 2,951,243 |  |  |  |  |
Payment for repurchase of common stock | $ 24,919,000 | $ 24,919,000 |  |  |  |  |
Stock Repurchase Program [Member] |  |  |  |  |  |  |
Stockholders Equity [Line Items] |  |  |  |  |  |  |
Repurchases of common stock |  |  |  | $ 26,000,000 | $ 20,000,000 | $ 10,000,000 | $ 10,000,000
Stock repurchased during period | 2,931,125 |  |  |  |  |  |
Payment for repurchase of common stock | $ 24,587,000 |  |  |  |  |  |
Stock purchased during period | 0 | 0 | 0 |  |  |  |
Shares remain authorized for repurchase amount | $ 22,874,509 |  |  |  |  |  |

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- Definition Amount of stock repurchase plan authorized. + References No definition available. + Details
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- Definition Amount remaining of a stock repurchase plan authorized. + References No definition available. + Details
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- Definition Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29,30) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655 + Details
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