COMMERCIAL MORTGAGE LOANS - Delinquent Loans (Details) - Commercial mortgage loans $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) loan	Dec. 31, 2019 USD ($) loan
Delinquent loans
Delinquent commercial mortgage loans | $	$ 848	$ 7,165
Number of delinquent commercial mortgage loans | loan	1	5
30-59 Days Delinquent
Delinquent loans
Delinquent commercial mortgage loans | $	$ 0	$ 6,455
Number of delinquent commercial mortgage loans | loan	0	2
60-89 Days Delinquent
Delinquent loans
Delinquent commercial mortgage loans | $	$ 848	$ 0
Number of delinquent commercial mortgage loans | loan	1	0
90 Days and Greater Delinquent
Delinquent loans
Delinquent commercial mortgage loans | $	$ 0	$ 710
Number of delinquent commercial mortgage loans | loan	0	3