Segment Information - Net Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net income (loss)	$ 2,365	$ 1,737	$ 2,085
Preferred stock dividends	21	21	21
Net income (loss) available to common stockholders	2,344	1,716	2,064
Operating Segments | P&C Commercial Lines
Segment Reporting Information [Line Items]
Net income (loss)	1,757	856	1,192
Operating Segments | P&C Personal Lines
Segment Reporting Information [Line Items]
Net income (loss)	385	718	318
Operating Segments | Property & Casualty Other Operations
Segment Reporting Information [Line Items]
Net income (loss)	(95)	(168)	61
Operating Segments | Group Benefits [Member]
Segment Reporting Information [Line Items]
Net income (loss)	249	383	536
Operating Segments | Hartford Funds
Segment Reporting Information [Line Items]
Net income (loss)	217	170	149
Corporate
Segment Reporting Information [Line Items]
Net income (loss)	$ (148)	$ (222)	$ (171)