Deferred Policy Acquisition and Sales Inducement Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred policy acquisition costs
Balance, beginning of year	$ 3,525	$ 3,372	$ 3,621
Classified as held for sale, beginning balance			743
Total, including those classified as held for sale			4,115
Acquisition costs deferred	4,596	4,350	4,267
Amortization charged to income	(4,364)	(4,135)	(4,002)
Effect of unrealized gains and losses	104	(98)	229
Sold in LBL disposition		(707)
Classified as held for sale			(743)
Balance, end of year	3,861	3,525	3,372
DSI activity relates to fixed annuities and interest-sensitive life contracts
Balance, beginning of year	44	42	41
Classified as held for sale, beginning balance	0	28	0
Total, including those classified as held for sale	44	70	41
Sales inducements deferred	3	4	24
Amortization charged to income	(4)	(4)	(7)
Effect of unrealized gains and losses	2	(3)	12
Sold in LBL disposition	0	(23)	0
Classified as held for sale, ending balance	0	0	28
Balance, end of year	45	44	42
Allstate Financial
Deferred policy acquisition costs
Balance, beginning of year	1,705	1,747	2,225
Classified as held for sale, beginning balance			743
Total, including those classified as held for sale			2,490
Acquisition costs deferred	285	280	364
Amortization charged to income	(262)	(260)	(328)
Effect of unrealized gains and losses	104	(98)	229
Sold in LBL disposition		(707)
Classified as held for sale			(743)
Balance, end of year	1,832	1,705	1,747
Property-Liability
Deferred policy acquisition costs
Balance, beginning of year	1,820	1,625	1,396
Classified as held for sale, beginning balance			0
Total, including those classified as held for sale			1,625
Acquisition costs deferred	4,311	4,070	3,903
Amortization charged to income	(4,102)	(3,875)	(3,674)
Effect of unrealized gains and losses	0	0	0
Sold in LBL disposition		0
Classified as held for sale			0
Balance, end of year	$ 2,029	$ 1,820	$ 1,625