SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Reinsurance (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amount of allowance for uncollectible amounts on paid recoverables	$ 15,700,000	$ 15,700,000
Reinsurance balances recoverable on unpaid losses and settlement expenses, allowances for uncollectible amounts	8,539,000	9,402,000
Financing Receivable, Allowance for Credit Loss, Writeoff	0
Financing Receivable, Allowance for Credit Loss, Recovery	$ 0
Restatement Adjustment | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption impact of ASU 2016-13 on reinsurance balances recoverable		$ 1,345,000