SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Traditional Life, Health, and Credit Insurance Products & Reinsurance (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Minimum
Liability for unpaid claims and claims adjustment expense
Interest rate assumptions to compute liabilities for future policy benefits	1.00%
Maximum
Liability for unpaid claims and claims adjustment expense
Interest rate assumptions to compute liabilities for future policy benefits	7.08%
Traditional Life Insurance | Minimum
Liability for unpaid claims and claims adjustment expense
Interest rate assumptions to compute liabilities for future policy benefits	2.50%
Traditional Life Insurance | Maximum
Liability for unpaid claims and claims adjustment expense
Interest rate assumptions to compute liabilities for future policy benefits	5.50%
Universal Life | Minimum
Liability for unpaid claims and claims adjustment expense
Interest rate credited to policy account balances	1.00%
Universal Life | Maximum
Liability for unpaid claims and claims adjustment expense
Interest rate credited to policy account balances	8.75%
Investments Product Line | Minimum
Liability for unpaid claims and claims adjustment expense
Interest rate credited to policy account balances	0.18%
Investments Product Line | Maximum
Liability for unpaid claims and claims adjustment expense
Interest rate credited to policy account balances	11.25%
Variable annuity | Guaranteed minimum death benefits (GMDB)
Liability for unpaid claims and claims adjustment expense
Impact of reinsurance	$ 30,227	$ 34,700	$ 26,934	$ 27,835