Restructuring and Other Costs, Before Tax (Details) - USD ($) $ in Millions	3 Months Ended		45 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs	$ 1	$ 0
Other Operating Income (Expense) [Member] | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	126		$ 126
Restructuring and other costs	1	0	125
Other Operating Income (Expense) [Member] | Information Technology | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	25		25
Restructuring and other costs	0	1	25
Other Operating Income (Expense) [Member] | Professional fees and other expenses | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	66		66
Restructuring and other costs	1	2	65
Other Operating Income (Expense) [Member] | Employee Severance | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	35		35
Restructuring and other costs	$ 0	$ (3)	$ 35