SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Investments in Real Estate Partnerships (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) investment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Accounting Policies [Abstract]
Limited partner interest (as a percent)	99.00%
Number of investments accounted for under the proportional amortization method | investment	1
Recorded investment in real estate partnerships	$ 3,600	$ 3,900
Investments accounted for under proportional amortization method	1,300	1,600
Losses accounted for under the equity method	55	331	$ 277
Losses on investments accounted for under proportional amortization method	214	214	217
Federal tax credits	$ 460	$ 578	$ 1,000