Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Schedule of Goodwill by reporting unit

The Company’s goodwill reporting units are equivalent to its reportable segments, Allstate Protection, Service Businesses, Allstate Life and Allstate Benefits to which goodwill has been assigned.

Goodwill by reporting unit
($ in millions)	December 31, 2017
Allstate Protection	$	810
Service Businesses	1,100
Allstate Life	175
Allstate Benefits	96
Total	$	2,181

Computation of basic and diluted earnings per common share

Computation of basic and diluted earnings per common share
	For the years ended December 31,
($ in millions, except per share data)	2017		2016		2015
Numerator:
Net income	$	3,189	$	1,877	$	2,171
Less: Preferred stock dividends	116		116		116
Net income applicable to common shareholders(1)	$	3,073	$	1,761	$	2,055
Denominator:
Weighted average common shares outstanding	362.0		372.8		401.1
Effect of dilutive potential common shares:
Stock options	4.3		3.2		4.0
Restricted stock units (non-participating) and performance stock awards	1.5		1.3		1.7
Weighted average common and dilutive potential common shares outstanding	367.8		377.3		406.8
Earnings per common share – Basic	$	8.49	$	4.72	$	5.12
Earnings per common share – Diluted	$	8.36	$	4.67	$	5.05

⁽¹⁾  Net income applicable to common shareholders is net income less preferred stock dividends.