SUMMARY OF ACCOUNTING POLICIES - maturity analysis of the annual undiscounted cash flows (Details) - USD ($)	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
operating lease liabilities
2020	$ 900,000
2021	828,000
2022	739,000
2023	637,000
2024	369,000
Thereafter	1,042,000
Total operating lease payments	4,515,000
Less imputed interest	(566,000)
Total operating lease liabilities	$ 3,949,000	$ 418,000	$ 3,949,000
Weighted-average remaining lease term	6 years 8 months 12 days
Weighted-average discount rate	4.40%