Accrued Restructuring and Other Costs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs	$ 5	$ 11
Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Payments for Restructuring	(7)	(14)
Employee Severance | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Payments for Restructuring	0	(6)
Restructuring Reserve, Ending Balance	16
Information Technology | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Payments for Restructuring	(2)	(2)
Professional fees and other expenses | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Payments for Restructuring	(5)	(6)
Other Operating Income (Expense) [Member] | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs	5	11
Other Operating Income (Expense) [Member] | Employee Severance | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs	2	0
Other Operating Income (Expense) [Member] | Information Technology | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs	2	2
Other Operating Income (Expense) [Member] | Professional fees and other expenses | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs	5	9
Other liabilities | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Beginning Balance	18	54
Restructuring Reserve, Ending Balance	16	51
Other liabilities | Employee Severance | Hartford Next Program
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Beginning Balance	18	54
Restructuring Reserve, Ending Balance	16	48
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
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	$ 3