Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash Flows From Operating Activities
Net income (loss)	$ (12.0)	$ 104.9
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized and unrealized investment losses	22.8	16.0
Net amortization and depreciation	2.2	3.3
Stock-based compensation expense	7.1	6.7
Amortization of defined benefit plan costs	2.0	1.4
Deferred income tax benefit	(7.7)	(5.5)
Change in deferred acquisition costs	7.0	(0.9)
Change in premiums receivable, net of reinsurance premiums payable	6.8	1.3
Change in loss, loss adjustment expense and unearned premium reserves	145.6	90.1
Change in reinsurance recoverable	(8.2)	(33.0)
Change in expenses and taxes payable	(114.0)	(103.4)
Cash received for MCCA refund, partially offset by payments made to policyholders		148.9
Other, net	(33.5)	(29.7)
Net cash provided by operating activities	18.1	200.1
Cash Flows From Investing Activities
Proceeds from disposals and maturities of fixed maturities	171.7	228.9
Proceeds from disposals of equity securities and other investments	7.8	75.2
Purchase of fixed maturities	(259.2)	(372.8)
Purchase of equity securities and other investments	(23.3)	(38.6)
Capital expenditures	(3.5)	(4.9)
Net cash used in investing activities	(106.5)	(112.2)
Cash Flows From Financing Activities
Proceeds from exercise of employee stock options	3.0	7.4
Dividends paid to shareholders	(28.9)	(26.7)
Repurchases of common stock	0.0	(16.3)
Other financing activities	(9.2)	(11.2)
Net cash used in financing activities	(35.1)	(46.8)
Net change in cash and cash equivalents	(123.5)	41.1
Cash and cash equivalents, beginning of period	305.0	230.9
Cash and cash equivalents, end of period	$ 181.5	$ 272.0