Reporting Segments (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information
Life and annuity premiums and contract charges									$ 2,352	$ 2,241	$ 2,238
Net investment income									3,943	4,010	3,971
Restructuring and related charges									(70)	(34)	(44)
Net income available to common shareholders	810	310	434	709	394	723	423	766	2,263	2,306	787
Amortization of DAC									4,002	3,884	3,971
Total income tax expense									1,116	1,000	172
Property-Liability
Segment Reporting Information
Underwriting income (loss)									2,218	1,200	(882)
Net investment income									1,375	1,326	1,201
Income tax expense (benefit) on operations									(1,177)	(779)	30
Realized capital gains and losses, after-tax									339	221	54
(Loss) gain on disposition of operations, after-tax									(1)
Net income available to common shareholders									2,754	1,968	403
Amortization of DAC									3,674	3,483	3,477
Total income tax expense									1,357	893	1
Allstate Protection
Segment Reporting Information
Underwriting income (loss)									2,361	1,253	(857)
Amortization of DAC									328	401	494
Total income tax expense									87	241	289
Discontinued Lines and Coverages
Segment Reporting Information
Underwriting income (loss)									(143)	(53)	(25)
Allstate Financial
Segment Reporting Information
Life and annuity premiums and contract charges									2,352	2,241	2,238
Net investment income									2,538	2,647	2,716
Periodic settlements and accruals on non-hedge derivative instruments									17	55	70
Contract benefits and interest credited to contract holder funds									(3,171)	(3,252)	(3,378)
Operating costs and expenses and amortization of deferred policy acquisition costs									(895)	(926)	(898)
Restructuring and related charges									(7)		(1)
Income tax expense (benefit) on operations									(246)	(236)	(240)
Operating income (loss)									588	529	507
Realized capital gains and losses, after-tax									46	(8)	250
Valuation changes on embedded derivatives that are not hedged, after-tax									(16)	82	(12)
DAC and DSI amortization related to realized capital gains and losses and valuation changes on embedded derivatives that are not hedged, after-tax									(5)	(42)	(108)
DAC and DSI unlocking related to realized capital gains and losses, after-tax									7	4	3
Reclassification of periodic settlements and accruals on non-hedge derivative instruments, after-tax									(11)	(36)	(45)
(Loss) gain on disposition of operations, after-tax									(514)	12	(5)
Net income available to common shareholders									95	541	590
Corporate and Other
Segment Reporting Information
Service fees									9	4	7
Net investment income									30	37	54
Operating costs and expenses									(627)	(383)	(403)
Income tax expense (benefit) on operations									220	136	126
Preferred stock dividends									(17)
Operating income (loss)									(385)	(206)	(216)
Realized capital gains and losses, after-tax										3	20
Loss on extinguishment of debt, after-tax									(319)
Postretirement benefits curtailment gain, after-tax									118
Business combination expenses, after-tax											(10)
Net income available to common shareholders									(586)	(203)	(206)
Total income tax expense									$ (328)	$ (134)	$ (118)