EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator [Abstract]
Net earnings	$ 2,967	$ 6,634	$ 4,098	$ 5,332
Undistributed earnings	2,132	5,814	2,425	3,681
Class A [Member]
Numerator [Abstract]
Net earnings	494	1,141	673	901
Less dividends declared	131	131	261	261
Undistributed earnings	$ 363	$ 1,010	$ 412	$ 640
Weighted-average shares outstanding [Abstract]
Basic and diluted (in shares)	2,175	2,175	2,175	2,175
Net earnings per share [Abstract]
Basic and diluted (in dollars per share)	$ 0.23	$ 0.52	$ 0.31	$ 0.41
Class B [Member]
Numerator [Abstract]
Net earnings	$ 2,473	$ 5,493	$ 3,425	$ 4,431
Less dividends declared	704	689	1,412	1,390
Undistributed earnings	$ 1,769	$ 4,804	$ 2,013	$ 3,041
Weighted-average shares outstanding [Abstract]
Basic and diluted (in shares)	10,112	9,844	10,100	9,850
Net earnings per share [Abstract]
Basic and diluted (in dollars per share)	$ 0.24	$ 0.56	$ 0.34	$ 0.45

Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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The earnings that is allocated to common stock and participating securities to the extent that each security may share in earnings as if all of the earnings for the period had been distributed.

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