Schedule II Condensed Financial Information of the Hartford Financial Services, Inc. - Cash Flow Disclosures (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activities
Net income (loss)	$ 548	$ 535	$ 372	$ 630	$ 196	$ 432	$ 582	$ 597	$ 2,085	$ 1,807	$ (3,131)
Loss on extinguishment of debt									(90)	(6)	0
Realized Gain (Loss) on Marketable Securities, Cost Method Investments, and Other Investments									(395)	165	(111)
Cash provided by operating activities									3,489	2,843	2,186
Investing Activities
Net proceeds from (payments for) short-term investments									1,491	(3,460)	(144)
Proceeds from Sale of Debt Securities, Available-for-sale									(18,499)	(24,700)	(31,646)
Payments for (Proceeds from) Other Investing Activities									13	(3)	21
Net additions to property and equipment									(105)	(122)	(250)
Net cash used for investing activities									(2,148)	(1,962)	(1,442)
Financing Activities
Treasury stock acquired									(200)		(1,028)
Dividends paid on common shares									(433)	(379)	(341)
Payments of Ordinary Dividends, Preferred Stock and Preference Stock									21
Net cash used for financing activities									(1,191)	(1,467)	(979)
Cash and restricted cash — beginning of period				112					112
Cash and restricted cash — end of period	185				112				185	112
Parent Company
Operating Activities
Net income (loss)									2,085	1,807	(3,131)
Loss on extinguishment of debt									(68)	(6)	0
Dividends from subsidiaries									18	3,115	2,142
Equity in net loss (income) of subsidiaries									(2,310)	(1,397)	1,972
Realized Gain (Loss) on Marketable Securities, Cost Method Investments, and Other Investments									3	(37)	2
Change in operating assets and liabilities									640	(716)	1,076
Cash provided by operating activities									504	2,778	2,061
Investing Activities
Net proceeds from (payments for) short-term investments									1,731	(2,161)	(121)
Proceeds from Sale of Debt Securities, Available-for-sale									(478)	0	0
Payments for (Proceeds from) Other Investing Activities									(33)	0	0
Net additions to property and equipment									0	(69)	0
Payments to Acquire Businesses, Net of Cash Acquired									(2,098)	0	0
Capital contributions to subsidiaries									(20)	(148)	(633)
Net cash used for investing activities									58	(2,378)	(754)
Financing Activities
Proceeds from issuance of debt									1,376	490	500
Repayments of long-term debt									(1,278)	(826)	(416)
Preferred stock issued, net of issuance costs									0	334	0
Treasury stock acquired									(200)		(1,028)
Net issuance (return of) shares under incentive and stock compensation plans									(6)	(18)	(20)
Dividends paid on common shares									(436)	(379)	(341)
Payments of Ordinary Dividends, Preferred Stock and Preference Stock									21	0	0
Net cash used for financing activities									(565)	(399)	(1,305)
Net increase (decrease) in cash									(3)	1	2
Cash and restricted cash — beginning of period				$ 3				$ 2	3	2	0
Cash and restricted cash — end of period	$ 0				$ 3				0	3	2
Supplemental Disclosure of Cash Flow Information
Interest Paid									$ 255	$ 290	$ 312