Condensed Consolidated Statements of Operations (unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenues
Net investment income	$ 562	$ 974	$ 1,156	$ 1,682
Net gains (losses) on investments and derivatives	(733)	287	(1,000)	713
Total revenues	12,220	12,646	24,557	25,097
Costs and expenses
Property and casualty insurance claims and claims expense	9,367	7,207	17,189	13,250
Shelter-in-Place Payback expense	0	29	0	29
Accident, health and other policy benefits	269	252	538	494
Amortization of deferred policy acquisition costs	1,619	1,545	3,231	3,068
Operating costs and expenses	1,850	1,683	3,752	3,414
Pension and other postretirement remeasurement (gains) losses	259	(134)	12	(444)
Restructuring and related charges	1	71	13	122
Amortization of purchased intangibles	87	105	174	158
Interest expense	83	91	166	177
Total costs and expenses	13,535	10,849	25,075	20,268
(Loss) income from operations before income tax expense	(1,315)	1,797	(518)	4,829
Income tax (benefit) expense	(291)	362	(140)	988
Net (loss) income from continuing operations	(1,024)	1,435	(378)	3,841
Income (loss) from discontinued operations, net of tax	0	196	0	(3,597)
Net (loss) income	(1,024)	1,631	(378)	244
Less: Net (loss) income attributable to noncontrolling interest	(9)	6	(19)	0
Net (loss) income attributable to Allstate	(1,015)	1,625	(359)	244
Less: Preferred stock dividends	27	30	53	57
Net (loss) income applicable to common shareholders	$ (1,042)	$ 1,595	$ (412)	$ 187
Basic
Continuing operations (in dollars per share)	$ (3.81)	$ 4.68	$ (1.49)	$ 12.59
Discontinued operations (in dollars per share)	0	0.66	0	(11.97)
Earnings per common share applicable to common shareholders - Basic (in dollars per share)	(3.81)	5.34	(1.49)	0.62
Diluted
Continuing operations (in dollars per share)	(3.81)	4.61	(1.49)	12.41
Discontinued operations (in dollars per share)	0	0.65	0	(11.80)
Earnings per common share applicable to common shareholders - Diluted (in dollars per share)	$ (3.81)	$ 5.26	$ (1.49)	$ 0.61
Weighted average common shares - Basic (in shares)	273.8	298.8	275.9	300.6
Weighted average common shares - Diluted (in shares)	273.8	303.3	275.9	304.9
Property and casualty insurance premiums
Revenues
Property and casualty insurance premiums	$ 11,362	$ 10,444	$ 22,343	$ 20,751
Accident and health insurance premiums and contract charges
Revenues
Insurance premiums, commissions and fees	466	447	935	902
Other revenue
Revenues
Insurance premiums, commissions and fees	$ 563	$ 494	$ 1,123	$ 1,049