SUBSEQUENT EVENTS - (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands					12 Months Ended
	Mar. 15, 2021	Mar. 01, 2021	Feb. 13, 2021	Jan. 01, 2021	Dec. 31, 2020	Mar. 08, 2021	Feb. 28, 2021	Jan. 31, 2021	Dec. 31, 2019
Subsequent Event [Line Items]
Reinsurance payable and funds withheld liabilities					$ 202,827				$ 102,467
2019-2020 Catastrophe Excess Loss Reinsurance Programs
Subsequent Event [Line Items]
Reinsurance payable and funds withheld liabilities					224,300
Combined FNIC, MIC and MNIC Twenty Twenty to Twenty Twenty-one Catastrophe Excess Loss Reinsurance Programs
Subsequent Event [Line Items]
Reinsurance payable and funds withheld liabilities					286,000
FNIC | 2019-2020 Catastrophe Excess Loss Reinsurance Programs
Subsequent Event [Line Items]
Excess retention, amount reinsured					27,000
Additional coverage amount					$ 20,000
FNIC | Combined FNIC, MIC and MNIC Twenty Twenty to Twenty Twenty-one Catastrophe Excess Loss Reinsurance Programs
Subsequent Event [Line Items]
Excess retention, retention percentage, co-participation					9.10%
Excess retention, threshold limit above initial insured amount					$ 70,000
Excess retention, amount reinsured					25,000
Second Event Coverage | 2019-2020 Catastrophe Excess Loss Reinsurance Programs | Maximum
Subsequent Event [Line Items]
Additional coverage amount					18,000
Second Event Coverage | Combined FNIC, MIC and MNIC Twenty Twenty to Twenty Twenty-one Catastrophe Excess Loss Reinsurance Programs | Maximum
Subsequent Event [Line Items]
Additional coverage amount					$ 16,000
Subsequent Event | Public Stock Offering
Subsequent Event [Line Items]
Number of shares issued (in shares)	3,500,000
Price per share (in dollars per share)	$ 4.75
Gross proceeds from sale of stock	$ 16,600
Net proceeds to the company from sale of stock	$ 15,200
Subsequent Event | Winter Storm Uri
Subsequent Event [Line Items]
Estimated loss from catastrophes			$ 41,000
Subsequent Event | FNIC | Hurricane Delta and Subsequent Events | Maison Insurance Company (MIC)
Subsequent Event [Line Items]
Excess retention, retention percentage, co-participation				65.00%
Reinsurance payable and funds withheld liabilities		$ 13,000		$ 2,300
Subsequent Event | First Event Coverage | FNIC | Hurricane Delta and Subsequent Events | Maison Insurance Company (MIC)
Subsequent Event [Line Items]
Excess retention, retention percentage, co-participation		50.00%		65.00%
Excess retention, threshold limit above initial insured amount		$ 70,000		$ 15,000
Excess retention, amount reinsured		$ 25,000		10,000
Excess retention, occurrence deductible				900
Subsequent Event | Second Event Coverage | Winter Storm Uri | 2019-2020 Catastrophe Excess Loss Reinsurance Programs | Maximum
Subsequent Event [Line Items]
Excess retention, threshold limit above initial insured amount			61,000
Additional coverage amount			18,000
Subsequent Event | Second Event Coverage | FNIC | Hurricane Delta and Subsequent Events | Maison Insurance Company (MIC)
Subsequent Event [Line Items]
Excess retention, retention percentage, co-participation		100.00%
Excess retention, threshold limit above initial insured amount		$ 15,000
Excess retention, amount reinsured		$ 10,000		$ 4,200
Subsequent Event | Florida | FNIC | Homeowners Multiple-Peril Insurance Policies
Subsequent Event [Line Items]
Approved rate increase, percent						6.70%
Application for rate increase, pending approval, percent						7.00%
Subsequent Event | Florida | FNIC | Dwelling Fire Insurance Policies
Subsequent Event [Line Items]
Application for rate increase, pending approval, percent						6.00%
Subsequent Event | Louisiana | FNIC | Homeowners Multiple-Peril Insurance Policies
Subsequent Event [Line Items]
Approved rate increase, percent								9.90%
Subsequent Event | Texas | FNIC | Homeowners Multiple-Peril Insurance Policies
Subsequent Event [Line Items]
Approved rate increase, percent							12.30%
Subsequent Event | Texas | FNIC | Winter Storm Uri | Combined FNIC, MIC and MNIC Twenty Twenty to Twenty Twenty-one Catastrophe Excess Loss Reinsurance Programs
Subsequent Event [Line Items]
Excess retention, amount reinsured			$ 23,000