CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021
Cash flows - operating activities
Net income		$ 45.0		$ 19.8	[1],[2]	$ 170.4	[1],[2]
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Net investment losses		24.0		56.5	[2]	11.0	[2]
Depreciation and intangible asset amortization		26.2		27.6	[2]	18.4	[2]
Share-based compensation expense		9.5		8.9	[2]	8.4	[2]
Loss (gain) from equity method investments, net of dividends or distributions		(14.5)		18.2	[2]	(41.5)	[2]
Other expense - goodwill impairments		0.0		4.8	[1],[2]	0.0	[1],[2]
Changes in:
Insurance liabilities		186.7		334.2	[2]	114.5	[2]
Amounts due under reinsurance agreements		(12.5)		(309.8)	[2]	7.4	[2]
Income tax liabilities		(15.0)		110.5	[2]	(91.2)	[2]
Other operating assets and liabilities		53.9		(109.4)	[2]	4.5	[2]
Other, net		(1.2)		10.2	[2]	3.0	[2]
Net cash provided by operating activities		302.1		171.5	[2]	204.9	[2]
Cash flows - investing activities
Fixed maturity securities purchases		(596.7)		(1,046.4)	[2]	(1,459.0)	[2]
Fixed maturity securities sales		377.6		752.0	[2]	578.2	[2]
Fixed maturity securities maturities, paydowns, calls and redemptions		291.9		496.8	[2]	873.3	[2]
Equity securities purchases		(2.5)		(5.2)	[2]	(46.1)	[2]
Equity securities sales and repayments		18.7		12.0	[2]	4.7	[2]
Limited partnership interests purchases		(207.2)		(356.4)	[2]	(320.6)	[2]
Limited partnership interests sales		41.4		66.6	[2]	86.5	[2]
Change in short-term and other investments, net		(39.8)		40.0	[2]	(8.8)	[2]
Acquisition of business, net of cash acquired		0.0		(164.4)	[2]	0.0	[2]
Other, net		9.2		(9.6)		(10.2)
Net cash used in investing activities		(107.4)		(214.6)	[2]	(302.0)	[2]
Cash flows - financing activities
Dividends paid to shareholders		(53.9)		(52.6)	[2]	(51.4)	[2]
Proceeds from issuance of 2023 Senior Notes due 2028		297.7		0.0	[2]	0.0	[2]
Principal borrowings on Revolving Credit Facility		0.0		0.0	[2]	114.0	[2]
FHLB borrowings		0.0		0.0		5.0
Principal repayment on Revolving Credit Facility		(249.0)		0.0		0.0
Principal repayment on FHLB borrowings		0.0		(5.0)	[2]	(54.0)	[2]
Treasury stock acquired		(6.5)		(24.0)	[2]	(5.3)	[2]
Withholding tax payments on RSUs tendered		(1.8)		(2.4)	[2]	(2.0)	[2]
Annuity contracts: variable, fixed and FHLB funding agreements
Deposits		787.6		636.5	[2]	1,060.4	[2]
Benefits, withdrawals and net transfers to Separate Account variable annuity assets		(604.7)		(472.2)	[2]	(462.7)	[2]
Repayment of FHLB funding agreements		(189.5)		(149.0)	[2]	(362.0)	[2]
Life policy accounts deposits, withdrawals, and surrenders		8.6		7.8	[2]	5.1	[2]
Change in deposit asset on reinsurance		(123.6)		(67.0)	[2]	(39.2)	[2]
Net increase (decrease) in reverse repurchase agreements		(70.2)		70.2	[2]	0.0	[2]
Change in book overdrafts		(2.5)		9.9	[2]	0.3	[2]
Net cash provided by (used in) financing activities		(207.8)		(47.8)	[2]	208.5	[2]
Net increase (decrease) in cash		(13.1)		(90.9)	[2]	111.4	[2]
Cash at beginning of year	[2]	42.8	[3]	133.7		22.3
Cash at end of year		$ 29.7		$ 42.8	[2],[3]	$ 133.7	[2]

[1] Recast for the adoption of ASU 2018-12. See Note 1 of the Consolidated Financial Statements

[2] Recast for the adoption of ASU 2018-12. See Note 1 of the Consolidated Financial Statements

[3] Recast for the adoption of ASU 2018-12. See Note 1 of the Consolidated Financial Statements