Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenues
Insurance premiums and contract charges	$ 61,449	$ 58,309	$ 52,516
Other revenue	2,955	2,930	2,400
Net investment income	3,449	3,092	2,478
Net gains (losses) on investments and derivatives	(168)	(225)	(300)
Total revenues	67,685	64,106	57,094
Costs and expenses
Accident, health and other policy benefits	656	1,241	1,071
Amortization of deferred policy acquisition costs	8,389	8,039	7,278
Operating costs and expenses	8,977	8,626	7,137
Pension and other postretirement remeasurement (gains) losses	(35)	(37)	9
Restructuring and related charges	61	61	169
Amortization of purchased intangibles	231	280	329
Interest expense	399	400	379
Total costs and expenses	56,132	58,345	57,442
Gain on disposition of operations	1,603	0	0
Income (loss) from operations before income taxes	13,156	5,761	(348)
Income tax expense (benefit)	2,890	1,162	(135)
Net income (loss)	10,266	4,599	(213)
Less: Net loss attributable to noncontrolling interest	(16)	(68)	(25)
Net income (loss) attributable to Allstate	10,282	4,667	(188)
Less: Preferred stock dividends	117	117	128
Net income (loss) applicable to common shareholders, basic	10,165	4,550	(316)
Net income (loss) applicable to common shareholders, diluted	$ 10,165	$ 4,550	$ (316)
Earnings per common share:
Net income (loss) applicable to common shareholders per common share - Basic (in dollars per share)	$ 38.56	$ 17.22	$ (1.20)
Weighted average common shares - Basic (in shares)	263.6	264.3	262.5
Net income (loss) applicable to common shareholders per common share - Diluted (in dollars per share)	$ 38.06	$ 16.99	$ (1.20)
Weighted average common shares - Diluted (in shares)	267.1	267.8	262.5
Property and casualty insurance premiums
Revenues
Insurance premiums and contract charges	$ 60,503	$ 56,388	$ 50,670
Costs and expenses
Property and casualty insurance claims and claims expense	37,454	39,735	41,070
Accident and health insurance premiums and contract charges
Revenues
Insurance premiums and contract charges	$ 946	$ 1,921	$ 1,846