Statutory Financial Information and Dividend Limitations (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Statutory Financial Information and Dividend Limitations
Restricted net assets	$ 25,000,000,000
Amount per statutory accounting practices
Net income	2,470,000,000	171,000,000	634,000,000
Capital and surplus	17,279,000,000	15,592,000,000
Dividend Limitations
Dividends paid	534,000,000	435,000,000	430,000,000
Allstate Insurance Company ("AIC")
Dividend Limitations
Dividends paid	1,510,000,000
Maximum amount of dividends in 2013 without prior approval	1,950,000,000
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	11,650,000,000
Property-Liability
Amount per statutory accounting practices
Net income	2,014,000,000	213,000,000	1,064,000,000
Capital and surplus	13,743,000,000	11,992,000,000
Allstate Financial
Amount per statutory accounting practices
Net income	456,000,000	(42,000,000)	(430,000,000)
Capital and surplus	$ 3,536,000,000	$ 3,600,000,000