Condensed Consolidated Statements of Shareholders’ Equity (unaudited) - USD ($) $ in Millions	Total	Preferred stock par value	Preferred stock additional capital paid-in	Common Stock, par value $.01 per share	Common stock additional capital paid-in	Retained income	Treasury stock	Accumulated other comprehensive income	Noncontrolling interest
Increase (decrease) in equity
Total equity					$ 3,722	$ 53,288	$ (34,471)	$ 426	$ (52)
Balance, beginning of period at Dec. 31, 2021					3,722	53,288	(34,471)	426	(52)
Increase (decrease) in equity
Equity incentive plans activity					(16)
Net (loss) income	$ 650					660			(10)
Dividends on common stock (declared per share of $0.89 and $0.85)						(236)
Dividends on preferred stock						(26)
Shares acquired							(794)
Shares reissued under equity incentive plans, net							57
Change in unrealized net capital gains and losses	(1,594)							(1,594)	(12)
Change in unrealized foreign currency translation adjustments	0							0
Change in unamortized pension and other postretirement prior service credit	(15)							(15)
Change in discount rate for reserve for future policy benefits	95							95
Balance, end of period at Mar. 31, 2022	23,001	$ 0	$ 1,970	$ 9	3,706	53,686	(35,208)	(1,088)	(74)
Increase (decrease) in equity
Total Allstate shareholders’ equity	23,075
Total equity	23,001	0	1,970	9	3,706	53,686	(35,208)	(1,088)	(74)
Total Allstate shareholders’ equity	17,488
Total equity	17,363				3,788	50,970	(36,857)	(2,392)	(125)
Balance, beginning of period at Dec. 31, 2022	17,363				3,788	50,970	(36,857)	(2,392)	(125)
Increase (decrease) in equity
Equity incentive plans activity					(8)
Net (loss) income	(321)					(320)			(1)
Dividends on common stock (declared per share of $0.89 and $0.85)						(236)
Dividends on preferred stock						(26)
Shares acquired							(153)
Shares reissued under equity incentive plans, net							30
Change in unrealized net capital gains and losses	682							682	5
Change in unrealized foreign currency translation adjustments	50							50
Change in unamortized pension and other postretirement prior service credit	(4)							(4)
Change in discount rate for reserve for future policy benefits	(9)							(9)
Balance, end of period at Mar. 31, 2023	17,373	0	1,970	9	3,780	50,388	(36,980)	(1,673)	(121)
Increase (decrease) in equity
Total Allstate shareholders’ equity	17,494
Total equity	$ 17,373	$ 0	$ 1,970	$ 9	$ 3,780	$ 50,388	$ (36,980)	$ (1,673)	$ (121)