INCOME TAXES - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Unpaid losses and loss adjustment expenses	$ 2.5	$ 1.5
Unearned premium reserves	3.8	1.9
Nondeductible accruals	0.5	0.9
Deferred rent	2.0	1.4
Research and development credits	0.9	0.9
Disallowed interest carryforward	9.6	3.7
Bad debt expense	1.2	0.8
Excess ceding commission	2.2	0.0
Deferred compensation	2.5	1.4
Stock compensation	5.4	0.5
Other	2.6	0.6
State net operating loss carryforward	10.2	5.3
Net operating loss carryforward	217.4	124.1
Gross deferred assets	260.8	143.0
Less valuation allowance	(255.0)	(137.3)
Total deferred tax assets, less valuation allowance	5.8	5.7
Deferred tax liabilities:
Internally developed software	2.7	2.1
Fixed assets	2.2	1.9
Deferred acquisition costs	0.6	0.4
Unrealized gains	0.1	1.2
Other	0.2	0.1
Deferred tax liabilities	5.8	5.7
Net deferred tax asset	$ 0.0	$ 0.0