Commitments and Contingencies (Details 2) (USD $) In Millions, unless otherwise specified	1 Months Ended		12 Months Ended
	Oct. 31, 2011 M Y anniversary	Oct. 07, 2011	Dec. 31, 2011 OB Services	Dec. 31, 2011 Furniture and equipment OB Services Y	Dec. 31, 2011 Capitalized software OB Services Y
Capital Lease
Capital lease term (in years)				5	4
Cash proceeds received a result of entering into the sale-leaseback transactions			$ 23.1
Capital lease obligation			23.1
Capital lease asset			22.9
Future annual minimum rental payments
2012			5.3
2013			5.3
2014			5.3
2015			5.3
2016			$ 1.9
Esurance
Period for which company has indemnified Allstate for breaches of representations and warranties (in months)	18
Period for which the entity has agreed not to engage in certain competing business activities (in years)	2
Period for which the entity has agreed not to solicit certain employees of the Transferred Subsidiaries (in years)	3
Percentage of positive or negative development in the loss reserves of the Transferred Subsidiaries retained		90.00%
Number of anniversaries from the closing date for which positive or negative development in the loss reserves of the Transferred Subsidiaries are to be computed	3