REINSURANCE (Narrative) (Details) - USD ($)													3 Months Ended	9 Months Ended
	Mar. 01, 2021	Feb. 01, 2021	Jan. 01, 2021	Dec. 31, 2020	Nov. 15, 2020	Nov. 04, 2020	Nov. 03, 2020	Nov. 02, 2020	Oct. 13, 2020	Oct. 01, 2020	Sep. 03, 2020	Jul. 01, 2020	Mar. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021
Liability for Catastrophe Claims [Line Items]
Reinsurance payable and funds withheld liabilities				$ 202,827,000									$ 136,795,000
Reinsurance recoverable				413,026,000									439,544,000
Maximum | Hurricane
Liability for Catastrophe Claims [Line Items]
Reinsurance recoverable				304,300,000									295,300,000
Federated Nationals Insurance Company Non Florida Reinsurance Program 2018-2019 | Maximum
Liability for Catastrophe Claims [Line Items]
Reinsurance payable and funds withheld liabilities													1,800,000
2019-2020 Catastrophe Excess Loss Reinsurance Programs
Liability for Catastrophe Claims [Line Items]
Reinsurance payable and funds withheld liabilities													224,300,000
2019-2020 Catastrophe Excess Loss Reinsurance Programs | Maximum | First Event Coverage
Liability for Catastrophe Claims [Line Items]
Reinsurance retention amount													20,000,000
Reinsurance amount retained on net basis with profit share agreement													10,000,000
2019-2020 Catastrophe Excess Loss Reinsurance Programs | Maximum | Second Event Coverage
Liability for Catastrophe Claims [Line Items]
Additional coverage amount													18,000,000
Reinsurance retention amount													2,000,000
Reinsurance amount retained on net basis with profit share agreement													1,000,000
2020-2021 Catastrophe Excess of Loss Reinsurance Program
Liability for Catastrophe Claims [Line Items]
Reinsurance payable and funds withheld liabilities													298,600,000
2020-2021 Catastrophe Excess of Loss Reinsurance Program | Maximum | First Event Coverage
Liability for Catastrophe Claims [Line Items]
Reinsurance retention amount													18,000,000
2020-2021 Catastrophe Excess of Loss Reinsurance Program | Maximum | Second Event Coverage
Liability for Catastrophe Claims [Line Items]
Additional coverage amount													16,000,000
Reinsurance retention amount													2,000,000
Federated National's Florida Exposure | 2019-2020 Catastrophe Excess Loss Reinsurance Programs
Liability for Catastrophe Claims [Line Items]
Reinsurance payable and funds withheld liabilities													178,500,000
Federated National's Florida Exposure | 2020-2021 Catastrophe Excess of Loss Reinsurance Program
Liability for Catastrophe Claims [Line Items]
Reinsurance payable and funds withheld liabilities													250,800,000
FHCF | 2019-2020 Catastrophe Excess Loss Reinsurance Programs
Liability for Catastrophe Claims [Line Items]
Reinsurance payable and funds withheld liabilities													$ 45,800,000
FHCF | 2019-2020 Catastrophe Excess Loss Reinsurance Programs | Maximum
Liability for Catastrophe Claims [Line Items]
Percentage of property quota share reinsurance treaty													90.00%
FHCF | 2020-2021 Catastrophe Excess of Loss Reinsurance Program
Liability for Catastrophe Claims [Line Items]
Maximum single event coverage													$ 650,000,000
Reinsurance payable and funds withheld liabilities													$ 47,800,000
FHCF | 2020-2021 Catastrophe Excess of Loss Reinsurance Program | Maximum
Liability for Catastrophe Claims [Line Items]
Percentage of property quota share reinsurance treaty													90.00%
FNIC
Liability for Catastrophe Claims [Line Items]
Trust agreement for loss exposure (Less than)				$ 100,000									$ 100,000
FNIC | 2019-2020 Catastrophe Excess Loss Reinsurance Programs
Liability for Catastrophe Claims [Line Items]
Excess retention, amount reinsured													27,000,000
Additional coverage amount													20,000,000
FNIC | 2020-2021 Catastrophe Excess of Loss Reinsurance Program
Liability for Catastrophe Claims [Line Items]
Excess retention, amount reinsured													$ 25,000,000
Retention percentage													100.00%
Amount reinsured, co-participation													$ 6,000,000
Retention percentage, co-participation													9.10%
Threshold limit above initial insured amount													$ 70,000,000
Potential decrease in retention if placed on parametric basis with an excess and surplus lines carrier													28.50%
FNIC | 2020-2021 Catastrophe Excess of Loss Reinsurance Program | Second and Third Event Coverage
Liability for Catastrophe Claims [Line Items]
Excess retention, amount reinsured													$ 10,000,000
Retention percentage, co-participation													71.50%
Threshold limit above initial insured amount													$ 15,000,000
Second and third event retention, combined basis													14,300,000
FNIC | 2020-2021 Catastrophe Excess of Loss Reinsurance Program | Second and Third Event Coverage | Hurricane Delta and Subsequent Events
Liability for Catastrophe Claims [Line Items]
Excess retention, amount reinsured						$ 13,500,000			$ 8,000,000		$ 39,200,000
Reinsurance payable and funds withheld liabilities						$ 2,000,000.0			$ 875,000		$ 11,200,000
Retention percentage, co-participation									50.00%
Threshold limit above initial insured amount									$ 10,000,000
FNIC | Quota Share One | Florida Homeowners Book of Business
Liability for Catastrophe Claims [Line Items]
Percentage of property quota share reinsurance treaty				10.00%	10.00%
FNIC | Quota Share One | Florida Homeowners Book of Business | Forecast
Liability for Catastrophe Claims [Line Items]
Percentage of property quota share reinsurance treaty														40.00%
Percentage of quota share up for renewal																20.00%
FNIC | Quota Share One | Federated Nationals Insurance Company Non Florida Reinsurance Program 2018-2019 | SageSure LLP
Liability for Catastrophe Claims [Line Items]
Percentage of property quota share reinsurance treaty												50.00%
Profit sharing agreement, profit sharing percent												50.00%
FNIC | Quota Share One | Non-Florida Homeowners Book Of Business
Liability for Catastrophe Claims [Line Items]
Percentage of property quota share reinsurance treaty							80.00%	50.00%
Percentage of quota share reinsurance treaty terminated			80.00%
New percentage quota share reinsurance treaty		80.00%
Proceeds from initial commutation agreement		$ 7,200,000
FNIC | Quota Share Two | Florida Homeowners Book of Business
Liability for Catastrophe Claims [Line Items]
Percentage of property quota share reinsurance treaty										20.00%		10.00%			10.00%
FNIC | Maison Insurance Company (MIC) | Hurricane Delta and Subsequent Events
Liability for Catastrophe Claims [Line Items]
Reinsurance payable and funds withheld liabilities	$ 13,000,000		$ 2,300,000
FNIC | Maison Insurance Company (MIC) | First Event Coverage | Hurricane Delta and Subsequent Events
Liability for Catastrophe Claims [Line Items]
Excess retention, amount reinsured			$ 10,000,000
Retention percentage, co-participation			65.00%
Threshold limit above initial insured amount	50,000,000		$ 15,000,000
Excess retention, occurrence deductible			850,000
FNIC | Maison Insurance Company (MIC) | Second Event Coverage | Hurricane Delta and Subsequent Events
Liability for Catastrophe Claims [Line Items]
Excess retention, amount reinsured	$ 10,000,000		$ 4,150,000
Number of layers protection was secured	2
Private and FHCF Reinsurance | 2019-2020 Catastrophe Excess Loss Reinsurance Programs
Liability for Catastrophe Claims [Line Items]
Maximum single event coverage													1,300,000,000
Maximum second and third event coverage													15,000,000
Liability for catastrophe claims													1,900,000,000
Private and FHCF Reinsurance | 2019-2020 Catastrophe Excess Loss Reinsurance Programs | Florida
Liability for Catastrophe Claims [Line Items]
Aggregate maximum single event coverage													$ 1,300,000,000
Private and FHCF Reinsurance | 2019-2020 Catastrophe Excess Loss Reinsurance Programs | Maximum
Liability for Catastrophe Claims [Line Items]
Percentage of property quota share reinsurance treaty													75.00%
Private and FHCF Reinsurance | 2020-2021 Catastrophe Excess of Loss Reinsurance Program
Liability for Catastrophe Claims [Line Items]
Maximum single event coverage													$ 650,000,000
Excess retention, amount reinsured													25,000,000
Liability for catastrophe claims													1,900,000,000
Aggregate maximum single event coverage													1,300,000,000
Private and FHCF Reinsurance | 2020-2021 Catastrophe Excess of Loss Reinsurance Program | Florida
Liability for Catastrophe Claims [Line Items]
Liability for catastrophe claims													1,900,000,000
Private and FHCF Reinsurance | 2020-2021 Catastrophe Excess of Loss Reinsurance Program | First Event Coverage
Liability for Catastrophe Claims [Line Items]
Excess retention, amount reinsured													$ 31,000,000
Private and FHCF Reinsurance | 2020-2021 Catastrophe Excess of Loss Reinsurance Program | Maximum
Liability for Catastrophe Claims [Line Items]
Percentage of property quota share reinsurance treaty													90.00%
Monarch National S Florida | 2019-2020 Catastrophe Excess Loss Reinsurance Programs
Liability for Catastrophe Claims [Line Items]
Maximum second and third event coverage													$ 10,000,000
Additional coverage amount													2,000,000
Maison | 2019-2020 Catastrophe Excess Loss Reinsurance Programs
Liability for Catastrophe Claims [Line Items]
Additional coverage amount													$ 5,000,000