Schedule II - Condensed Financial Information of Registrant - Statement of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net income (loss)	$ 4,667	$ (188)	$ (1,289)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Net (gains) losses on investments and derivatives	225	300	1,072
Pension and other postretirement remeasurement (gains) losses	(37)	9	116
Changes in:
Net cash provided by operating activities	8,931	4,228	5,121
Cash flows from investing activities
Change in short-term investments, net	724	(617)	792
Net cash used in investing activities	(8,252)	(2,999)	(1,728)
Cash flows from financing activities
Proceeds from issuance of debt	495	743	0
Redemption and repayment of debt	(350)	(750)	0
Proceeds from issuance of preferred stock	0	587	0
Dividends paid on common stock	(962)	(925)	(926)
Dividends paid on preferred stock	(117)	(107)	(105)
Treasury stock purchases	(2)	(335)	(2,520)
Shares reissued under equity incentive plans, net	163	73	82
Other	(16)	(49)	(35)
Net cash used in financing activities	(697)	(1,243)	(3,420)
Net increase (decrease) in cash	(18)	(14)	(27)
Cash at beginning of period	722	736	763
Cash at end of period	704	722	736
Allstate Corporation
Cash flows from operating activities
Net income (loss)	4,667	(188)	(1,289)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Equity in net income (loss) of subsidiaries	(4,954)	(257)	929
Dividends received from subsidiaries	130	250	3,396
Net (gains) losses on investments and derivatives	9	28	34
Pension and other postretirement remeasurement (gains) losses	(21)	12	179
Changes in:
Pension and other postretirement benefits	(36)	55	(98)
Income taxes	29	(78)	(14)
Operating assets and liabilities	109	43	76
Net cash provided by operating activities	(67)	(135)	3,213
Cash flows from investing activities
Proceeds from sales of investments	411	1,427	2,572
Investment purchases	(405)	(50)	(2,507)
Investment collections	374	85	39
Capital contribution or return of capital from subsidiaries	325	975	145
Disbursements for loans to subsidiaries	(380)	0	0
Proceeds from loans to subsidiaries	26	0	0
Change in short-term investments, net	(209)	(7)	6
Net cash used in investing activities	142	2,430	255
Cash flows from financing activities
Proceeds from borrowings from subsidiaries	350	0	1,000
Repayment of notes due to subsidiaries	0	(1,000)	(1,000)
Proceeds from issuance of debt	495	743	0
Redemption of preferred stock	0	(575)	0
Redemption and repayment of debt	0	(750)	0
Proceeds from issuance of preferred stock	0	587	0
Dividends paid on common stock	(962)	(925)	(926)
Dividends paid on preferred stock	(117)	(107)	(105)
Treasury stock purchases	(2)	(335)	(2,520)
Shares reissued under equity incentive plans, net	163	73	82
Other	(1)	(6)	0
Net cash used in financing activities	(74)	(2,295)	(3,469)
Net increase (decrease) in cash	1	0	(1)
Cash at beginning of period	0	0	1
Cash at end of period	$ 1	$ 0	$ 0