TRANSACTIONS WITH AFFILIATES (Details) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended				12 Months Ended
	Jun. 30, 2019 USD ($) $ / shares	Jun. 30, 2018 USD ($)	Dec. 31, 2019 USD ($) Plan	Jun. 30, 2019 USD ($) Plan $ / shares	Dec. 31, 2018 USD ($) Plan	Jun. 30, 2018 USD ($) Plan	Dec. 31, 2019 USD ($) Plan	Dec. 31, 2018 USD ($) Plan
Related Party Transaction [Line Items]
Offer Price By Parent | $ / shares	$ 36			$ 36
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Ceded premiums earned	$ 109,073	$ 103,303		$ 214,633		$ 203,341
Ceded losses and settlement expenses incurred	62,709	62,677		$ 125,904		$ 114,678
Affiliated Entity [Member] | Property and casualty insurance [Member]
Related Party Transaction [Line Items]
Number of reinsurance program treaties | Plan			1	1	1	1	2	2
Ceded premiums earned	107,761	101,991		$ 212,008		$ 200,716
Ceded losses and settlement expenses incurred	63,497	62,386		124,959		115,140
Affiliated Entity [Member] | Property and casualty insurance [Member] | Annual Aggregate Catastrophe Excess of Loss [Member]
Related Party Transaction [Line Items]
Catastrophe claims, retention amount			$ 15,000	22,000	$ 15,000	22,000
Affiliated reinsurance contract first layer limit			12,000	24,000	12,000	24,000
Ceded premiums earned			$ 1,400	6,000	$ 1,400	6,000
Ceded losses and settlement expenses incurred	1,002	317		1,529		784
Affiliated Entity [Member] | Reinsurance [Member]
Related Party Transaction [Line Items]
Number of reinsurance program treaties | Plan							2
Ceded premiums earned	1,312	1,312		2,625		2,625
Ceded losses and settlement expenses incurred	$ (788)	$ 291		$ 945		$ (462)
Reinsurance Recovered On Industry Loss Warranties								$ 0
Affiliated Entity [Member] | Reinsurance [Member] | Per Occurrence Catastrophe Excess of Loss [Member]
Related Party Transaction [Line Items]
Catastrophe claims, retention amount							$ 10,000
Affiliated reinsurance contract first layer limit							$ 10,000
First layer excess of loss coinsurance percentage (in hundreths)							20.00%
Ceded premiums earned							$ 1,600
Affiliated Entity [Member] | Reinsurance [Member] | Annual Aggregate Catastrophe Excess of Loss [Member]
Related Party Transaction [Line Items]
Catastrophe claims, retention amount							20,000
Affiliated reinsurance contract first layer limit							$ 100,000
First layer excess of loss coinsurance percentage (in hundreths)							20.00%
Ceded premiums earned							$ 3,600
Catastrophe event minimum amount							$ 500