REVENUE RECOGNITION (Additional Information) (Details) - USD ($)		3 Months Ended								12 Months Ended
	Jan. 02, 2018	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net Income (Loss) Attributable to Parent		$ 24,592,000	$ 22,776,000	$ 19,670,000	$ 17,299,000	$ 22,198,000	$ 21,454,000	$ 21,713,000	$ 21,682,000	$ 84,337,000	$ 87,047,000	$ 80,411,000
Retained Earnings
Net Income (Loss) Attributable to Parent										$ 84,337,000	$ 87,047,000	$ 80,411,000
Retained Earnings | Revision of Prior Period, Change in Accounting Principle, Adjustment
Net Income (Loss) Attributable to Parent	$ 24,000