NET INCOME PER COMMON SHARE AND EQUITY PER COMMON SHARE (Details) - $ / shares	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	May 23, 2023
Shares used in computing basic and diluted net income per share [Abstract]
Weighted average common shares outstanding during the period for Basic computation (in shares)	10,287,000	9,504,000
Dilutive effect of employee stock options and awards (in shares)	4,000	6,000
Weighted average common shares outstanding during the period for Diluted computation (in shares)	10,291,000	9,510,000
Earnings Per Share [Abstract]
Equity per common share (in dollars per share)	$ 0.43	$ 0.39
Class A Stock [Member]
Common Stock [Abstract]
Common stock, par value (in dollars per share)				$ 1
Common Stock [Member] | Class A Stock [Member]
Common Stock [Abstract]
Common stock, shares authorized (in shares)	15,000,000	15,000,000
Common stock, shares issued (in shares)	9,406,808	8,622,999
Common stock, shares outstanding (in shares)	9,406,808	8,622,999
Common stock, par value (in dollars per share)	$ 1	$ 1
Earnings Per Share [Abstract]
Equity per common share (in dollars per share)	$ 22.55		$ 23
Common Stock [Member] | Class B Stock [Member]
Common Stock [Abstract]
Common stock, shares authorized (in shares)	1,040,000	1,040,000
Common stock, shares issued (in shares)	881,452	881,452
Common stock, shares outstanding (in shares)	881,452	881,452
Common stock, par value (in dollars per share)	$ 1	$ 1
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Abstract]
Shares excluded from calculations of diluted net income per share (in shares)	0	0
Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Abstract]
Shares excluded from calculations of diluted net income per share (in shares)	0	0