Consolidated Statements of Cash Flows - USD ($) $ in Millions		2 Months Ended	11 Months Ended	12 Months Ended
		Dec. 31, 2023	Nov. 15, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows provided by (used in) operating activities:
Net income (loss)		$ 0.9	$ (210.4)	$ (175.2)	$ 6.7
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Amortization and depreciation		39.6	12.2	18.5	43.4
Share-based payments expense		0.0	1.5	9.6	8.0
Deferred income tax benefit, net		1.3	(14.9)	15.4	(38.6)
Net investment and other (gains) losses		0.3	22.7	115.3	(32.6)
Undistributed earnings from alternative investment portfolio		(2.2)	(11.5)	(17.7)	(95.5)
Loss on disposals of long-lived assets, net		0.0	1.2	0.6	23.3
Foreign currency exchange loss		0.6	1.8	0.0	0.0
Impairment of goodwill and intangibles		0.0	0.0	28.5	43.2
Change in:
Accrued investment income		(3.3)	1.4	0.2	0.8
Receivables		98.5	614.3	(193.6)	47.4
Deferred acquisition costs		(7.2)	8.8	(12.6)	0.8
Ceded unearned premiums		31.6	(69.7)	88.4	65.7
Reserves for losses and loss adjustment expenses		17.2	(27.9)	446.2	210.8
Unearned premiums		(69.6)	(12.0)	(74.7)	7.2
Ceded reinsurance payable and funds held		(57.3)	20.1	(162.9)	(207.3)
Income taxes		0.1	14.6	(47.5)	(4.5)
Accrued underwriting expenses and other liabilities		(19.3)	18.7	14.7	3.0
Other, net		(14.3)	(77.2)	0.0	17.9
Net cash flows from operating activities		16.9	293.7	53.2	99.7
Cash flows provided by (used in) investing activities:
Sales of fixed maturity investments		0.7	24.2	818.5	992.9
Maturities and mandatory calls of fixed maturity investments		22.3	139.3	380.1	717.7
Sales of equity securities		0.0	45.7	17.8	125.8
Sales of other investments		22.2	24.0	58.1	212.3
Purchases of fixed maturity investments		(10.1)	(11.9)	(1,093.6)	(1,932.9)
Purchases of equity securities		0.0	(0.3)	(1.0)	(5.3)
Purchases of other investments		(2.9)	(19.3)	(52.8)	(47.4)
Change in foreign regulatory deposits and voluntary pools		0.0	0.0	(6.7)	(27.1)
Purchase of mortgage loans		0.0	0.0	(159.9)	0.0
Change in short-term investments		24.1	(627.0)	26.1	(116.4)
Settlements of foreign currency exchange forward contracts		1.3	4.5	(22.0)	(1.2)
Proceeds from business divestitures, net of cash transferred		4.2	63.8	14.9	0.0
Purchases of fixed assets, net		0.0	(2.7)	(6.1)	18.0
Other, net		0.0	0.0	0.0	7.7
Cash provided by (used in) investing activities		61.8	(359.7)	(26.6)	(55.9)
Cash flows provided by (used in) financing activities:
Activity under stock incentive plans		0.0	0.7	1.8	1.3
Payment of cash dividends to preferred stockholders		0.0	(10.5)	(10.5)	(10.5)
Payment of cash dividends to common stockholders		0.0	0.3	(43.4)	(43.7)
Cash used in financing activities		0.0	(9.5)	(52.1)	(52.9)
Effect of exchange rate changes on cash		0.0	0.3	0.4	6.4
Net change in cash and restricted cash including balances classified as held-for-sale		78.7	(75.2)	(25.1)	(2.7)
Cash, restricted cash and cash equivalents	[1]	0.0	70.8	(70.8)	0.0
Cash, restricted cash, and cash equivalents, beginning of period		45.8	50.2	146.1	148.8
Cash, restricted cash, and cash equivalents, end of period		$ 791.6	$ 45.8	$ 50.2	$ 146.1

[1] See Note 2 for details of the assets and liabilities classified as “held-for-sale” as of December 31, 2022.