SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT (Details 2) - USD ($) $ / shares in Units, $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets
Fixed income securities, at fair value (amortized cost $485 and $878)	$ 57,948	$ 62,440
Short-term investments, at fair value (amortized cost $277 and $673)	2,122	2,540
Cash	495	657	$ 675	$ 806
Total assets	104,656	108,479	123,460
Liabilities
Long-term debt	5,124	5,140
Total liabilities	84,631	86,175
Shareholders’ equity
Common stock, $.01 par value, 2.0 billion shares authorized and 900 million issued, 381 million and 418 million shares outstanding	9	9
Additional capital paid-in	3,245	3,199
Retained income	39,413	37,842
Deferred ESOP expense	(13)	(23)
Treasury stock, at cost (519 million and 482 million shares)	(23,620)	(21,030)
Accumulated other comprehensive income:
Unrealized net capital gains and losses	620	1,926
Unrealized foreign currency translation adjustments	(60)	(2)
Unrecognized pension and other postretirement benefit cost	(1,315)	(1,363)
Total accumulated other comprehensive (loss) income	(755)	561
Total shareholders’ equity	20,025	22,304
Total liabilities and shareholders’ equity	104,656	108,479
Additional balance sheet disclosures:
Short-term, at fair value, amortized cost (in dollars)	$ 2,122	$ 2,540
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares issued	72,200	72,200
Preferred stock, shares outstanding	72,200	72,200
Preferred stock, shares aggregate liquidation preference (in dollars)	$ 1,805	$ 1,805
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares issued	900,000,000	900,000,000
Common stock, shares outstanding	381,000,000	418,000,000
Treasury stock, shares	519,000,000	482,000,000
Allstate Corporation
Assets
Investments in subsidiaries	$ 25,047	$ 26,362
Fixed income securities, at fair value (amortized cost $485 and $878)	485	880
Short-term investments, at fair value (amortized cost $277 and $673)	277	673
Cash	4	155	$ 105	$ 4
Receivable from subsidiaries	339	342
Deferred income taxes	302	352
Other assets	133	167
Total assets	26,587	28,931
Liabilities
Long-term debt	5,124	5,140
Pension and other postretirement benefit obligations	948	977
Deferred compensation	259	263
Dividends payable to shareholders	150	155
Deferred income taxes	0	0
Other liabilities	81	92
Total liabilities	6,562	6,627
Shareholders’ equity
Preferred stock and additional capital paid-in, $1 par value, 25 million shares authorized, 72.2 thousand issued and outstanding, and $1,805 aggregate liquidation preference	1,746	1,746
Common stock, $.01 par value, 2.0 billion shares authorized and 900 million issued, 381 million and 418 million shares outstanding	9	9
Additional capital paid-in	3,245	3,199
Retained income	39,413	37,842
Deferred ESOP expense	(13)	(23)
Treasury stock, at cost (519 million and 482 million shares)	(23,620)	(21,030)
Accumulated other comprehensive income:
Unrealized net capital gains and losses	620	1,926
Unrealized foreign currency translation adjustments	(60)	(2)
Unrecognized pension and other postretirement benefit cost	(1,315)	(1,363)
Total accumulated other comprehensive (loss) income	(755)	561
Total shareholders’ equity	20,025	22,304
Total liabilities and shareholders’ equity	26,587	28,931
Additional balance sheet disclosures:
Fixed income securities, at fair value, amortized cost (in dollars)	485	878
Short-term, at fair value, amortized cost (in dollars)	$ 277	$ 673
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares issued	72,200	72,200
Preferred stock, shares outstanding	72,200	72,200
Preferred stock, shares aggregate liquidation preference (in dollars)	$ 1,805	$ 1,805
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares issued	900,000,000	900,000,000
Common stock, shares outstanding	381,000,000	418,000,000
Treasury stock, shares	519,000,000	482,000,000