Condensed Consolidated Statements of Operations (unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenues
Other revenue	$ 679	$ 597	$ 1,348	$ 1,158
Net investment income	712	610	1,476	1,185
Net gains (losses) on investments and derivatives	(103)	(151)	(267)	(137)
Total revenues	15,714	13,979	30,973	27,765
Costs and expenses
Accident, health and other policy benefits	291	258	587	523
Amortization of deferred policy acquisition costs	2,001	1,789	3,940	3,533
Operating costs and expenses	2,019	1,786	3,904	3,502
Pension and other postretirement remeasurement (gains) losses	(9)	(40)	(11)	(93)
Restructuring and related charges	13	27	23	54
Amortization of purchased intangibles	70	82	139	163
Interest expense	98	98	195	184
Total costs and expenses	15,284	15,727	29,079	29,919
Income (loss) from operations before income tax expense	430	(1,748)	1,894	(2,154)
Income tax expense (benefit)	83	(373)	349	(458)
Net income (loss)	347	(1,375)	1,545	(1,696)
Less: Net income (loss) attributable to noncontrolling interest	16	(23)	(4)	(24)
Net income (loss) attributable to Allstate	331	(1,352)	1,549	(1,672)
Less: Preferred stock dividends	30	37	59	63
Net income (loss) applicable to common shareholders, basic	301	(1,389)	1,490	(1,735)
Net income (loss) applicable to common shareholders, diluted	$ 301	$ (1,389)	$ 1,490	$ (1,735)
Earnings per common share:
Net income (loss) applicable to common shareholders per common share - Basic (in dollars per share)	$ 1.14	$ (5.29)	$ 5.65	$ (6.59)
Weighted average common shares - Basic (in shares)	264.1	262.6	263.8	263.1
Net income (loss) applicable to common shareholders per common share - Diluted (in dollars per share)	$ 1.13	$ (5.29)	$ 5.58	$ (6.59)
Weighted average common shares - Diluted (in shares)	267.1	262.6	266.8	263.1
Property and casualty insurance premiums
Revenues
Insurance premiums and contract charges	$ 13,952	$ 12,470	$ 27,464	$ 24,643
Costs and expenses
Property and casualty insurance claims and claims expense	10,801	11,727	20,302	22,053
Accident and health insurance premiums and contract charges
Revenues
Insurance premiums and contract charges	$ 474	$ 453	$ 952	$ 916