Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Investments:
Fixed maturities available-for-sale, at fair value (cost: 2024 - $2,370.0, 2023 - $2,521.5; allowance for expected credit losses: 2024 - $0.2, 2023 - $0.2)	$ 2,413.4	$ 2,585.4
Mortgage loans (cost: 2024 - $171.6, 2023 - $144.8; allowance for expected credit losses: 2024 - $0.5, 2023 - $0.2)	171.1	144.6
Equity securities, at fair value (cost: 2024 - $9.5; 2023 - $11.7)	8.6	10.7
Other investments (cost: 2024 - $344.4; 2023 - $311.0)	344.4	311.0
Short-term investments, at fair value (cost: 2024 - $1,073.7; 2023 - $429.0)	1,073.6	429.5
Total investments	4,011.1	3,481.2
Cash, restricted cash and cash equivalents	462.4	791.6
Accrued investment income	18.0	20.4
Premiums receivable	209.8	230.7
Reinsurance recoverables	2,933.1	2,959.3
Other intangible assets, net of accumulated amortization	170.3	180.6
Current income taxes receivable, net	54.2	53.1
Deferred tax asset, net	41.7	39.1
Deferred acquisition costs, net	32.2	7.2
Ceded unearned premiums	353.7	356.0
Operating lease right-of-use assets	52.8	51.2
Other assets	196.9	189.1
Value of business acquired, net of accumulated amortization	110.9	143.6
Total assets	8,647.1	8,503.1
Liabilities and Stockholders' Equity
Reserves for losses and loss adjustment expenses	5,543.1	5,544.5
Unearned premiums	842.1	916.6
Accrued underwriting expenses and other liabilities	56.3	73.9
Ceded reinsurance payable, net	229.4	192.7
Funds held	48.6	57.3
Borrowing under revolving credit facility	100.0	0.0
Senior unsecured fixed rate notes	128.1	128.0
Junior subordinated debentures	241.6	241.2
Operating lease liabilities	53.4	51.4
Total liabilities	7,242.6	7,205.6
Commitments and contingencies (Note 12)
Stockholders' equity:
Series A Preferred stock and additional paid-in capital - $1.00 par, 30,000,000 shares authorized; 6,000 and 6,000 shares issued at March 31, 2024 and December 31, 2023, respectively; liquidation preference $25,000	137.1	137.1
Common stock - $1.00 par, 2,000,000,000 shares authorized; 1,156,638,730 and 1,056,638,730 shares issued at March 31, 2024 and December 31, 2023, respectively	1,156.6	1,056.6
Additional paid-in capital	51.1	51.1
Retained earnings	23.9	0.9
Accumulated other comprehensive income, net of taxes	35.8	51.8
Total stockholders' equity	1,404.5	1,297.5
Total liabilities and stockholders' equity	$ 8,647.1	$ 8,503.1