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STOCK COMPENSATION PLANS (Details) |  | 3 Months Ended
--- | --- | ---
May 06, 2020 $ / shares shares | Mar. 31, 2021 USD ($) Director $ / shares shares | Mar. 31, 2020 USD ($)
Stock Compensation Plans [Abstract] |  |  |
Compensation expense |  | $ 43,000 | $ 45,000
Number of directors in committee | Director |  | 3 |
Total intrinsic value of options exercised |  | $ 484,000 |
Shares of Class A Non-Voting Common Stock under option [Abstract] |  |  |
Exercised/vested and released, aggregate intrinsic value |  | 484,000 |
Class A Stock [Member] | Stock Options [Member] |  |  |
Stock Compensation Plans [Abstract] |  |  |
Total intrinsic value of options exercised |  | $ 484,000 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] |  |  |
Outstanding at beginning of period, option shares (in shares) | shares |  | 116,347 |
Granted, option shares (in shares) | shares |  | 0 |
Exercised/vested and released, option shares (in shares) | shares |  | (21,885) |
Expired/cancelled, option shares (in shares) | shares |  | 0 |
Outstanding at end of period, option shares (in shares) | shares |  | 94,462 |
Exercisable/vested at end of period, option share (in shares) | shares |  | 94,462 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] |  |  |
Outstanding at beginning of period, weighted average exercise price (in dollars per shares) | $ / shares |  | $ 2,090 |
Granted, weighted average exercise price (in dollars per share) | $ / shares |  | 0 |
Exercised/vested and released, weighted average exercise price (in dollars per shares) | $ / shares |  | 19 |
Expired/cancelled, weighted average exercise price (in dollars per share) | $ / shares |  | 0 |
Outstanding at end of period, weighted average exercise price (in dollars per shares) | $ / shares |  | 21 |
Options exercisable at year end (in dollars per shares) | $ / shares |  | $ 21 |
Shares of Class A Non-Voting Common Stock under option [Abstract] |  |  |
Outstanding at end of period, weighted average remaining life |  | 2 years |
Exercisable/vested at end of period, weighted average remaining life |  | 2 years |
Outstanding at beginning of period, aggregate intrinsic value |  | $ 1,882,000 |
Granted, aggregate intrinsic value |  | 0 |
Exercised/vested and released, aggregate intrinsic value |  | 484,000 |
Expired/cancelled, aggregate intrinsic value |  | 0 |
Outstanding at end of period, aggregate intrinsic value |  | 1,704,000 |
Exercisable/vested at end of period, aggregate intrinsic value |  | 1,704,000 |
Class A Stock [Member] | Stock Options [Member] | 2015 Equity Compensation Plan [Member] |  |  |
Stock Compensation Plans [Abstract] |  |  |
Unrecognized expense related to non-vested option shares |  | 0 |
Class A Stock [Member] | Restricted Stock [Member] |  |  |
Stock Compensation Plans [Abstract] |  |  |
Compensation expense |  | $ 43,000 | $ 45,000
Fair value per share (in dollars per share) | $ / shares | $ 35.01 |  |
Shares [Roll Forward] |  |  |
Outstanding at beginning of year (in shares) | shares |  | 5,000 |
Granted (in shares) | shares | 5,000 | 0 |
Exercised/vested and released, restricted stock awards (in shares) | shares |  | 0 |
Cancelled (in shares) | shares |  | 0 |
Unvested Outstanding at end of year (in shares) | shares |  | 5,000 |
Weighted Average Grant Date Fair Value [Abstract] |  |  |
Outstanding at beginning of year (in dollars per shares) | $ / shares |  | $ 35 |
Granted, weighted average grant date fair value (in dollars per share) | $ / shares |  | 0 |
Vested and released, weighted average grant date fair value (in dollars per shares) | $ / shares |  | 0 |
Cancelled, weighted average grant date fair value (in dollars per share) | $ / shares |  | 0 |
Unvested Outstanding at end of year (in dollars per shares) | $ / shares |  | $ 35 |
Class A Stock [Member] | Restricted Stock [Member] | 2015 Equity Compensation Plan [Member] |  |  |
Stock Compensation Plans [Abstract] |  |  |
Unrecognized expense related to non-vested option shares |  | $ 17,000 |
Period over which unvested options cost will recognized |  | 1 month 6 days |

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