Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows (used in) provided by operating activities:
Net income (loss)	$ (1.0)	$ 29.8
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Amortization and depreciation	5.9	2.9
Share-based payments expense	3.2	2.3
Deferred income tax benefit, net	9.3	0.3
Net realized investment (gains) losses	34.5	(13.1)
Undistributed earnings from alternative investment portfolio	(13.6)	(20.7)
Change in:
Accrued investment income	(1.2)	(0.6)
Receivables	43.9	242.5
Deferred acquisition costs	(6.5)	(6.5)
Ceded unearned premiums	(2.9)	(11.8)
Reserves for losses and loss adjustment expenses	101.4	(268.2)
Unearned premiums	(38.5)	(33.6)
Ceded reinsurance payable and funds held	(147.8)	158.2
Income taxes	3.2	1.3
Accrued underwriting expenses and other liabilities	11.5	6.4
Other, net	(29.3)	(19.0)
Cash (used in) provided by operating activities	(27.9)	70.2
Cash flows provided by (used in) investing activities:
Sales of fixed maturity investments	291.1	264.0
Maturities and mandatory calls of fixed maturity investments	144.3	195.9
Sales of equity securities	9.0	14.6
Sales of other investments	20.9	27.1
Purchases of fixed maturity investments	(597.4)	(617.6)
Purchases of equity securities	(1.0)	(0.5)
Purchases of other investments	(17.9)	(20.6)
Change in foreign regulatory deposits and voluntary pools	(8.6)	(9.1)
Change in mortgage loans	(46.5)	0.0
Change in short-term investments	234.1	59.7
Settlements of foreign currency exchange forward contracts	0.0	(1.7)
Proceeds from sale of Argo Seguros Brasil, net of cash transferred	22.7	0.0
Purchases of fixed assets, net	(0.7)	(7.7)
Other, net	0.0	45.9
Cash used in investing activities	50.0	(50.0)
Cash flows used in financing activities:
Activity under stock incentive plans	(1.1)	0.3
Payment of cash dividends to preferred shareholders	(2.6)	(2.6)
Payment of cash dividends to common shareholders	(10.8)	(10.8)
Cash used in financing activities	(14.5)	(13.1)
Effect of exchange rate changes on cash	0.3	0.8
Change in cash	7.9	7.9
Cash, beginning of year	146.1	148.8
Cash, end of period	$ 154.0	$ 156.7