EQUITY (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Sep. 19, 2016
Stock-based compensation
Number of shares reserved to be granted under the plan	2,000,000
Number of shares available for grant	463,000
Treasury Stock
Shares Repurchased	139,784	161,500	45,807
Aggregate Cost	$ 12,258,000	$ 8,327,000	$ 2,582,000
Shares repurchased to satisfy tax withholdings and exercise obligations	33,271	32,227	42,703
Aggregate cost to satisfy tax withholdings and exercise obligations	$ 1,713,000	$ 1,733,000	$ 2,419,000
Average Repurchase Price (in dollars per share)	$ 51.49	$ 53.78	$ 56.65
Number of Options
Exercised (in shares)			17,000
Stock-based compensation, additional disclosures
Cash proceeds received upon exercise of options	$ 383,000
2016 Repurchase Plan
Treasury Stock
Authorized amount				$ 50,000,000.0
Shares Repurchased	244,798	129,273	3,104
Aggregate Cost	$ 10,546,000	$ 6,589,000	$ 162,000
Average Repurchase Price (in dollars per share)	$ 43.08	$ 50.97	$ 52.37
Value of shares available for repurchase	$ 20,400,000
Stock options
Stock-based compensation
Expiration term	10 years
Vesting period	4 years
Number of Options
Outstanding at the beginning of the period (in shares)	15,000	15,000
Granted (in shares)	0	0
Forfeited (in shares)		0
Expired (in shares)		0
Exercised (in shares)	10,000	0
Outstanding at the end of the period (in shares)	5,000	15,000	15,000
Vested and expected to vest at the end of the period (in shares)	5,000	15,000
Exercisable at the end of the period (in shares)	5,000
Weighted Avg. Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 49.34	$ 49.34
Granted (in dollars per share)		0
Forfeited (in dollars per share)		0
Expired (in dollars per share)		0
Exercised (in dollars per share)	38.30	0
Outstanding at the end of the period (in dollars per share)	71.43	49.34	$ 49.34
Vested and expected to vest at the end of the period (in dollars per share)	71.43	$ 49.34
Exercisable at the end of the period (in dollars per share)	$ 71.43
Weighted Average Remaining Contractual Term
Outstanding	3 years 8 months 12 days	2 years 2 months 12 days
Vested and expected to vest	3 years 8 months 12 days	2 years 2 months 12 days
Exercisable	3 years 8 months 12 days
Aggregate Intrinsic Value
Outstanding		$ 34,600
Vested and expected to vest		34,600
Stock-based compensation, additional disclosures
Aggregate intrinsic value of options exercised	$ 84,000		$ 229,000
Cash proceeds received upon exercise of options	$ 383,000
Restricted Stock
Stock-based compensation
Vesting period	4 years
Unamortized stock based compensation
Unamortized stock based compensation	$ 7,800,000
Weighted-average period for recognition of unamortized stock-based compensation cost	2 years 4 months 24 days
Stock compensation expense
Stock compensation expense	$ 5,400,000	$ 5,600,000	$ 6,400,000
Shares
Unvested at the beginning of the period (in shares)	223,623	204,146
Granted (in shares)	117,794	116,404
Forfeited (in shares)	(14,213)	(3,323)
Vested and issued (in shares)	(99,136)	(93,604)
Unvested at the end of the period (in shares)	228,068	223,623	204,146
Weighted Avg. Fair Value
Unvested at the beginning of the period (in dollars per share)	$ 54.42	$ 60.13
Granted (in dollars per share)	48.76	50.45
Forfeited (in dollars per share)	50.86	59.99
Vested and issued (in dollars per share)	55.95	61.75
Unvested at the end of the period (in dollars per share)	$ 51.05	$ 54.42	$ 60.13
Restricted Stock | Management
Stock compensation expense
Stock compensation expense	$ 400,000	$ 300,000	$ 500,000
2008 Plan | Performance Stock
Number of Options
Granted (in shares)	43,000
Forfeited (in shares)	0
Weighted Avg. Exercise Price
Granted (in dollars per share)	$ 59.77
Unamortized stock based compensation
Unamortized stock based compensation	$ 1,900,000
Weighted-average period for recognition of unamortized stock-based compensation cost	2 years 2 months 12 days
Stock compensation expense
Stock compensation expense	$ 700,000	$ 0	$ 0
Shares
Unvested at the end of the period (in shares)	43,000