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Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Additional disclosures [Abstract] |  |  |
Stock-based compensation expense | $ 4,581 | $ 4,210 | $ 3,936
Number of shares available for future grant (in shares) | 781,123 |  |
Stock Options [Member] |  |  |
Share-based compensation [Abstract] |  |  |
Stock awards termination period | 10 years |  |
Stock options [Roll Forward] |  |  |
Outstanding, beginning of period (in shares) | 33,145 |  |
Exercised (in shares) | (8,845) |  |
Expired (in shares) | (10,500) |  |
Outstanding, end of period (in shares) | 13,800 | 33,145 |
Exercisable, end of period (in shares) | 13,800 |  |
Stock options, weighted average exercise price [Abstract] |  |  |
Outstanding, beginning of period (in dollars per share) | $ 23.73 |  |
Exercised (in dollars per share) | 20.87 |  |
Expired (in dollars per share) | 20.74 |  |
Outstanding, end of period (in dollars per share) | 27.83 | $ 23.73 |
Exercisable, end of period (in dollars per share) | $ 27.83 |  |
Additional disclosures [Abstract] |  |  |
Weighted average remaining contractual term, outstanding, end of period | 3 years 4 months 9 days |  |
Weighted average remaining contractual term, exercisable, end of period | 3 years 4 months 9 days |  |
Aggregate intrinsic value, outstanding, end of period | $ 75 |  |
Aggregate intrinsic value, exercisable, end of period | 75 |  |
Stock-based compensation expense | 0 | $ 1 | 11
Proceeds from stock options exercised | 185 | 725 | 999
Tax benefits related to stock options exercised | 41 | 123 | 173
Intrinsic value of stock options exercised | 165 | 490 | 692
Fair value of shares vested during the year | 0 | 13 | 16
Restricted Stock [Member] |  |  |
Additional disclosures [Abstract] |  |  |
Stock-based compensation expense | $ 4,600 | $ 4,200 | 3,900
Restricted Stock [Member] | Employees [Member] | Minimum [Member] |  |  |
Share-based compensation [Abstract] |  |  |
Stock awards vesting period | 3 years |  |
Restricted Stock [Member] | Employees [Member] | Maximum [Member] |  |  |
Share-based compensation [Abstract] |  |  |
Stock awards vesting period | 5 years |  |
Restricted Stock [Member] | Non-employee Directors [Member] |  |  |
Share-based compensation [Abstract] |  |  |
Stock awards vesting period | 3 years |  |
Restricted Stock Units (RSUs) [Member] |  |  |
Restricted stock and restricted stock units [Roll Forward] |  |  |
Unvested, beginning of period (in shares) | 555,440 |  |
Forfeited (in shares) | (2,315) |  |
Vested (in shares) | (115,432) |  |
Granted (in shares) | 147,562 |  |
Unvested, end of period (in shares) | 585,255 | 555,440 |
Restricted stock and restricted stock units, weighted average grant date fair value [Abstract] |  |  |
Unvested, beginning of period (in dollars per share) | $ 30.11 |  |
Forfeited (in dollars per share) | 34.82 |  |
Vested (in dollars per share) | 29.93 |  |
Granted (in dollars per share) | 28.61 |  |
Unvested, end of period (in dollars per share) | $ 29.78 | $ 30.11 |
Restricted Stock Awards and Stock Units [Member] |  |  |
Additional disclosures [Abstract] |  |  |
Tax benefit on restricted stock awards | $ 1,000 | $ 1,100 | $ 1,200
Unrecognized compensation cost | $ 5,100 |  |
Unrecognized compensation cost, weighted average period of recognition | 1 year 6 months |  |

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- Definition The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target 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)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit 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)(2)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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