REINSURANCE (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Loss and LAE reserves:
Direct	$ 269.3				$ 269.3	$ 313.2	$ 237.2
Assumed	18.1				18.1	7.0	0.0
Ceded	(76.4)				(76.4)	(79.5)	(79.6)	$ (18.9)
Net loss and LAE reserves	211.0				211.0	240.7	157.6	$ 121.8
Unearned premiums:
Direct	125.8				125.8	170.6	157.1
Assumed	10.7				10.7	9.5	0.0
Ceded	(74.2)				(74.2)	(100.8)	(112.8)
Net unearned premiums	62.3				62.3	79.3	44.3
Premiums written:
Direct					556.8	725.9	616.8
Assumed					43.2	16.7	0.0
Ceded					(331.2)	(397.3)	(378.0)
Net premiums written					268.8	345.3	238.8
Premiums earned:
Direct					601.6	712.3	605.2
Assumed					42.0	7.3	0.0
Ceded					(357.7)	(409.3)	(282.7)
Net premiums earned	64.3	$ 68.6	$ 74.7	$ 78.3	285.9	310.3	322.5
Losses and LAE incurred:
Direct					549.8	683.9	557.6
Assumed					44.9	10.9	0.0
Ceded					(243.7)	(302.5)	(194.8)
Net losses and LAE incurred	77.7	$ 80.9	$ 95.7	$ 96.7	351.0	392.3	$ 362.8
Maximum amount of ceded commissions returned	19.0				19.0	26.5
Reinsurance recoverable unpaid losses	143.3				143.3	160.7
Provision for loss corridor	$ 66.2				$ 66.2	$ 80.4