Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenues
Insurance premiums and contract charges	$ 58,309	$ 52,516	$ 47,736
Other revenue	2,930	2,400	2,344
Net investment income	3,092	2,478	2,403
Net gains (losses) on investments and derivatives	(225)	(300)	(1,072)
Total revenues	64,106	57,094	51,411
Costs and expenses
Accident, health and other policy benefits (including remeasurement (gains) losses of $1, $0, and $(4))	1,241	1,071	1,042
Amortization of deferred policy acquisition costs	8,039	7,278	6,634
Operating costs and expenses	8,626	7,137	7,446
Pension and other postretirement remeasurement (gains) losses	(37)	9	116
Restructuring and related charges	61	169	51
Amortization of purchased intangibles	280	329	353
Interest expense	400	379	335
Total costs and expenses	58,345	57,442	53,241
Income (loss) from operations before income tax expense	5,761	(348)	(1,830)
Income tax expense (benefit)	1,162	(135)	(488)
Net income (loss)	4,599	(213)	(1,342)
Less: Net loss attributable to noncontrolling interest	(68)	(25)	(53)
Net income (loss) attributable to Allstate	4,667	(188)	(1,289)
Less: Preferred stock dividends	117	128	105
Net income (loss) applicable to common shareholders, basic	4,550	(316)	(1,394)
Net income (loss) applicable to common shareholders, diluted	$ 4,550	$ (316)	$ (1,394)
Earnings per common share:
Net income (loss) applicable to common shareholders per common share - Basic (in dollars per share)	$ 17.22	$ (1.20)	$ (5.14)
Weighted average common shares - Basic (in shares)	264.3	262.5	271.2
Net income (loss) applicable to common shareholders per common share - Diluted (in dollars per share)	$ 16.99	$ (1.20)	$ (5.14)
Weighted average common shares - Diluted (in shares)	267.8	262.5	271.2
Property and casualty insurance premiums
Revenues
Insurance premiums and contract charges	$ 56,388	$ 50,670	$ 45,904
Costs and expenses
Property and casualty insurance claims and claims expense	39,735	41,070	37,264
Accident and health insurance premiums and contract charges
Revenues
Insurance premiums and contract charges	$ 1,921	$ 1,846	$ 1,832