Accrued Restructuring and Other Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs	$ 1	$ 104	$ 0
Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Payments for Restructuring	(37)	(50)
Employee Severance | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Payments for Restructuring	(11)	(19)
Information Technology | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Payments for Restructuring	(9)	(2)
Professional fees and other expenses | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Payments for Restructuring	(17)	(29)
Other Operating Income (Expense) [Member] | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs	1	104
Other Operating Income (Expense) [Member] | Employee Severance | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs	25	73
Other Operating Income (Expense) [Member] | Information Technology | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs	9	2
Other Operating Income (Expense) [Member] | Professional fees and other expenses | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs	17	29
Other liabilities | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Beginning Balance	54	0
Restructuring Reserve, Ending Balance	18	54	0
Other liabilities | Employee Severance | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Beginning Balance	54	0
Restructuring Reserve, Ending Balance	18	54	0
Other liabilities | Information Technology | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Beginning Balance	0	0
Restructuring Reserve, Ending Balance	0	0	0
Other liabilities | Professional fees and other expenses | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Beginning Balance	0	0
Restructuring Reserve, Ending Balance	$ 0	$ 0	$ 0