Statutory Financial Information and Dividend Limitations (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Amount per statutory accounting practices
Net income (loss)	$ 1,717	$ 1,770	$ 3,631
Capital and surplus	$ 16,819	16,486
Dividend Limitations
Action level RBC expressed as a multiplier of authorized control level RBC, which if not achieved would require specific actions to be taken	2
Restricted net assets	$ 23,000
Allstate Insurance Company ("AIC")
Amount per statutory accounting practices
Capital and surplus	15,880
Dividend Limitations
Dividends paid	1,900
Maximum amount of dividends without prior approval	$ 1,560
Advance notice period required for payment of dividend in excess of amount available for distribution without prior approval	30 days
Unassigned surplus excluding unrealized appreciation from investments	$ 10,260
Authorized control level RBC	2,560
Property-Liability
Amount per statutory accounting practices
Net income (loss)	1,520	1,826	2,501
Capital and surplus	13,436	13,332
Allstate Financial
Amount per statutory accounting practices
Net income (loss)	197	(56)	$ 1,130
Capital and surplus	$ 3,383	$ 3,154