CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net loss	$ (74.8)	$ (49.0)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1.5	0.9
Stock-based compensation	14.1	6.1
Amortization of discount on bonds	2.5	0.0
Provision for bad debt	2.0	0.9
Changes in operating assets and liabilities:
Premium receivable	(10.6)	(13.3)
Reinsurance recoverable	(22.7)	(16.8)
Prepaid reinsurance premium	(7.1)	(13.1)
Deferred acquisition costs	(0.5)	(0.6)
Other assets	(4.2)	(1.6)
Unpaid loss and loss adjustment expense	9.7	15.9
Unearned premium	14.7	19.7
Trade payables	1.6	(0.4)
Funds held for reinsurance treaties	5.1	3.9
Deferred ceding commissions	2.3	3.6
Ceded premium payable	16.1	2.3
Other liabilities and accrued expenses	10.8	1.2
Net cash used in operating activities	(39.5)	(40.3)
Cash flows from investing activities:
Proceeds from short-term investments sold or matured	44.7	0.0
Proceeds from bonds sold or matured	9.2	0.0
Cost of short-term investments acquired	(17.9)	0.0
Cost of bonds acquired	(29.1)	0.0
Purchases of property and equipment	(2.8)	(2.0)
Net cash provided by (used in) investing activities	4.1	(2.0)
Cash flows from financing activities:
Proceeds from Follow-on Offering, net of underwriting discounts and commissions and offering costs	0.0	640.3
Proceeds from stock exercises	0.6	6.1
Net cash provided by financing activities	0.6	646.4
Effect of exchange rate changes on cash and cash equivalents	(0.8)	(0.8)
Net (decrease) increase in cash, cash equivalents and restricted cash	(35.6)	603.3
Cash, cash equivalents and restricted cash at beginning of period	270.6	571.4
Cash, cash equivalents and restricted cash at end of period	235.0	1,174.7
Supplemental disclosure of cash flow information:
Cash paid for income taxes	$ 1.1	$ 0.6