Reinsurance - Components of Net Realized Capital Gains (Losses) on Funds Withheld Assets (Details) - Talcott Life & Annuity Re - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Reinsurance
Net realized capital gains (losses)	$ (23.1)	$ (47.3)	$ (151.8)	$ 54.5
Fixed maturities, available-for-sale
Reinsurance
Net realized capital gains (losses)	(22.7)	(53.2)	(146.3)	60.7
Fixed maturities, trading
Reinsurance
Net realized capital gains (losses)		(5.6)	(0.1)	(6.4)
Equity securities
Reinsurance
Net realized capital gains (losses)		0.4	(1.2)	(2.4)
Mortgage loans
Reinsurance
Net realized capital gains (losses)		(0.2)	(9.2)	(1.8)
Derivatives
Reinsurance
Net realized capital gains (losses)	$ (0.4)	(0.5)	$ 5.0	(1.0)
Other
Reinsurance
Net realized capital gains (losses)		$ 11.8		$ 5.4