Segment Information - Non-insurance Revenue from Customers (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Insurance Commissions and Fees	$ 341	$ 375	$ 703	$ 730
Other revenues	19	26	35	38
Non-insurance revenues with customers	361	396	740	770
Installment billing fees [Member] | Operating Segments [Member] | Commercial Lines
Segment Reporting Information [Line Items]
Insurance Commissions and Fees	10	8	19	17
Installment billing fees [Member] | Operating Segments [Member] | Personal Lines
Segment Reporting Information [Line Items]
Insurance Commissions and Fees	7	8	15	16
Insurance servicing revenues | Operating Segments [Member] | Personal Lines
Segment Reporting Information [Line Items]
Other revenues	19	21	36	40
Administrative services | Operating Segments [Member] | Group Benefits
Segment Reporting Information [Line Items]
Insurance Commissions and Fees	48	49	93	93
Advisor, distribution and other management fees | Operating Segments [Member] | Hartford Funds
Segment Reporting Information [Line Items]
Insurance Commissions and Fees	263	296	550	578
Investment management and other fees | Corporate
Segment Reporting Information [Line Items]
Insurance Commissions and Fees	13	14	26	26
Other | Corporate
Segment Reporting Information [Line Items]
Other revenues	$ 1	$ 0	$ 1	$ 0