Deferred Policy Acquisition and Sales Inducement Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred policy acquisition costs
Balance, beginning of year	$ 3,861	$ 3,525	$ 3,372
Classified as held for sale, beginning balance				$ 743
Total, including those classified as held for sale				4,115
Acquisition costs deferred	4,717	4,596	4,350
Amortization charged to income	(4,550)	(4,364)	(4,135)
Effect of unrealized gains and losses	(74)	104	(98)
Sold in LBL disposition			(707)
Balance, end of year	3,954	3,861	3,525
DSI activity relates to fixed annuities and interest-sensitive life contracts
Balance, beginning of year	45	44	42
Classified as held for sale, beginning balance	0	0	28
Total, including those classified as held for sale		45	44	70
Sales inducements deferred	1	3	4
Amortization charged to income	(5)	(4)	(4)
Effect of unrealized gains and losses	(1)	2	(3)
Sold in LBL disposition	0	0	(23)
Balance, end of year	40	45	44
Allstate Financial
Deferred policy acquisition costs
Balance, beginning of year	1,832	1,705	1,747
Classified as held for sale, beginning balance				743
Total, including those classified as held for sale				2,490
Acquisition costs deferred	291	285	280
Amortization charged to income	(283)	(262)	(260)
Effect of unrealized gains and losses	(74)	104	(98)
Sold in LBL disposition			(707)
Balance, end of year	1,766	1,832	1,705
Property-Liability
Deferred policy acquisition costs
Balance, beginning of year	2,029	1,820	1,625
Classified as held for sale, beginning balance				0
Total, including those classified as held for sale				$ 1,625
Acquisition costs deferred	4,426	4,311	4,070
Amortization charged to income	(4,267)	(4,102)	(3,875)
Effect of unrealized gains and losses	0	0	0
Sold in LBL disposition			0
Balance, end of year	$ 2,188	$ 2,029	$ 1,820