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Stock Option Plan - Additional Information (Detail) |  |  |  |  | 12 Months Ended |
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May 07, 2021 USD ($) person $ / shares shares | Dec. 31, 2020 USD ($) shares | Apr. 24, 2020 USD ($) person $ / shares shares | May 03, 2019 USD ($) person $ / shares shares | Dec. 31, 2021 USD ($) $ / shares shares | Dec. 31, 2020 USD ($) $ / shares | Dec. 31, 2019 USD ($) $ / shares | Dec. 31, 2004 | Dec. 31, 2005 shares
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Deferred compensation (in shares) | shares |  | 120,240 |  |  | 9,486 |  |  |  |
Exercise price of options (in usd per share) | $ / shares |  |  |  |  | $ 43.89 | $ 50.00 | $ 55.71 |  |
Intrinsic value of options exercised |  |  |  |  | $ 400,000 | $ 100,000 | $ 600,000 |  |
Intrinsic value of options exercisable |  | $ 2,300,000 |  |  | $ 4,900,000 | $ 2,300,000 |  |  |
Closing price (in usd per share) | $ / shares |  |  |  |  | $ 53.02 |  |  |  |
Allocated share based compensation |  |  |  |  | $ 1,300,000 |  |  |  |
Future expense |  |  |  |  | $ 1,700,000 |  |  |  |
2019 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Exercise price of options (in usd per share) | $ / shares |  |  |  | $ 55.71 |  |  |  |  |
Fair value stock option grant |  |  |  | $ 1,900,000 |  |  |  |  |
2020 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Exercise price of options (in usd per share) | $ / shares |  |  | $ 50.00 |  |  |  |  |  |
Closing price (in usd per share) | $ / shares |  |  | $ 28.02 |  |  |  |  |  |
Fair value stock option grant |  |  | $ 200,000 |  |  |  |  |  |
2021 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Exercise price of options (in usd per share) | $ / shares | $ 43.89 |  |  |  |  |  |  |  |
Fair value stock option grant | $ 1,400,000 |  |  |  |  |  |  |  |
Common Stock |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Shares due to exercise of employee stock options and issuance of directors' deferred stock | shares |  |  |  |  | 7,874 |  |  |  |
Officer | 2019 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Number of individuals granted options | person |  |  |  | 23 |  |  |  |  |
Options vested |  |  |  | 25.00% |  |  |  |  |
Fair value stock option grant |  |  |  | $ 1,700,000 |  |  |  |  |
Officer | 2020 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Number of individuals granted options | person |  |  | 20 |  |  |  |  |  |
Options vested |  |  | 25.00% |  |  |  |  |  |
Fair value stock option grant |  |  | $ 200,000 |  |  |  |  |  |
Officer | 2021 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Number of individuals granted options | person | 21 |  |  |  |  |  |  |  |
Options vested | 25.00% |  |  |  |  |  |  |  |
Fair value stock option grant | $ 1,200,000 |  |  |  |  |  |  |  |
Director | 2019 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Number of individuals granted options | person |  |  |  | 11 |  |  |  |  |
Fair value stock option grant |  |  |  | $ 226,600 |  |  |  |  |
Director | 2020 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Number of individuals granted options | person |  |  | 11 |  |  |  |  |  |
Fair value stock option grant |  |  | $ 23,100 |  |  |  |  |  |
Director | 2021 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Number of individuals granted options | person | 11 |  |  |  |  |  |  |  |
Fair value stock option grant | $ 173,800 |  |  |  |  |  |  |  |
Stock options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Expiration period |  |  |  |  |  |  |  | 10 years |
Stock options | Amended 2004 Plan |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Authorized shares for a grant | shares |  |  |  |  |  |  |  |  | 3,400,000
Stock options | 2019 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Options granted to purchase stocks (in shares) | shares |  |  |  | 260,000 |  |  |  |  |
Stock options | 2020 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Options granted to purchase stocks (in shares) | shares |  |  | 238,000 |  |  |  |  |  |
Stock options | 2021 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Options granted to purchase stocks (in shares) | shares | 250,500 |  |  |  |  |  |  |  |
Stock options | Officer |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Option vesting period |  |  |  |  |  |  |  | 4 years |
Stock options | Officer | 2019 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Option vesting period |  |  |  | 4 years |  |  |  |  |
Stock options | Officer | 2020 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Option vesting period |  |  | 4 years |  | 4 years |  |  |  |
Stock options | Officer | 2021 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Option vesting period | 4 years |  |  |  | 4 years |  |  |  |
Incentive stock option | 2019 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Options granted to purchase stocks (in shares) | shares |  |  |  | 34,651 |  |  |  |  |
Incentive stock option | 2020 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Options granted to purchase stocks (in shares) | shares |  |  | 29,624 |  |  |  |  |  |
Incentive stock option | 2021 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Options granted to purchase stocks (in shares) | shares | 35,572 |  |  |  |  |  |  |  |
Nonqualified stock options | 2019 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Options granted to purchase stocks (in shares) | shares |  |  |  | 225,349 |  |  |  |  |
Nonqualified stock options | 2020 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Options granted to purchase stocks (in shares) | shares |  |  | 208,376 |  |  |  |  |  |
Nonqualified stock options | 2021 Options |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] |  |  |  |  |  |  |  |  |
Options granted to purchase stocks (in shares) | shares | 214,928 |  |  |  |  |  |  |  |

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