Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Schedule of unearned premiums

The portion of premiums written applicable to the unexpired terms of the policies is recorded as unearned premiums.

Unearned premiums
	As of December 31,
($ in millions)	2020		2019
Allstate Protection	$	12,772	$	12,567
Protection Services	3,167		2,765
Total	$	15,939	$	15,332

Allowance for credit loss

Rollforward of credit loss allowance for premium installment receivables
($ in millions)	For the year ended December 31, 2020
Beginning balance	$	(91)
Increase in the provision for credit losses	(223)
Write-off of uncollectible premium installment receivable amounts	161
Ending balance	$	(153)

Allowance for credit losses
($ in millions)	December 31, 2020		January 1, 2020
Fixed income securities	$	3	$	—
Mortgage loans	67		45
Other investments
Bank loans	67		53
Agent loans	5		5
Investments	142		103
Premium installment receivables	153		91
Reinsurance recoverables	74		74
Other assets	23		18
Assets	392		286
Commitments to fund mortgage loans, bank loans and agent loans	1		3
Liabilities	1		3
Total	$	393	$	289

Rollforward of credit loss allowance for fixed income securities
	For the year ended
($ in millions)	December 31, 2020
Beginning balance	$	—
Credit losses on securities for which credit losses not previously reported	(5)
Reduction of allowance related to sales	2
Write-offs	—
Ending balance (1)	$	(3)

(1)Allowance for fixed income securities as of December 31, 2020 comprised $1 million and $2 million of corporate bonds and ABS, respectively.

Rollforward of credit loss allowance for mortgage loans
($ in millions)	For the year ended December 31, 2020
Beginning balance	$	(3)
Cumulative effect of change in accounting principle	(42)
Net increases related to credit losses	(39)
Reduction of allowance related to sales	17
Write-offs	—
Ending balance	$	(67)

Rollforward of credit loss allowance for bank loans
	For the year ended December 31, 2020
($ in millions)
Beginning balance	$	—
Cumulative effect of change in accounting principle	(53)
Net increases related to credit losses	(28)
Reduction of allowance related to sales	9
Write-offs	5
Ending balance	$	(67)

Schedule of goodwill by reporting unit

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

Goodwill by reporting unit
	As of December 31,
($ in millions)	2020		2019
Allstate Protection	$	810	$	810
Protection Services	1,463		1,464
Allstate Life	175		175
Allstate Benefits	96		96
Total	$	2,544	$	2,545

Future amortization expense

Amortization expense of intangible assets for the next five years and thereafter
($ in millions)
2021	$	91
2022	74
2023	60
2024	45
2025	33
Thereafter	31
Total amortization	$	334

Schedule of indefinite-lived intangible assets

Intangible assets by type
	As of December 31,
($ in millions)	2020		2019
Customers relationships	$	322	$	419
Trade names and licenses	37		38
Technology and other	94		24
Total	$	453	$	481

Schedule of finite-lived intangible assets

Intangible assets by type
	As of December 31,
($ in millions)	2020		2019
Customers relationships	$	322	$	419
Trade names and licenses	37		38
Technology and other	94		24
Total	$	453	$	481

Other information related to operating leases

Other information related to operating leases
	As of December 31,
	2020		2019
Weighted average remaining lease term (years)	5		6
Weighted average discount rate	3.10	%	3.15	%

Maturity of lease liabilities

Maturity of lease liabilities
($ in millions)	Operating leases
2021	$	120
2022	116
2023	95
2024	77
2025	63
Thereafter	84
Total lease payments	$	555
Less: interest	(44)
Present value of lease liabilities	$	511

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)	2020		2019		2018
Numerator:
Net income	$	5,576	$	4,847	$	2,160
Less: Preferred stock dividends	115		169		148
Net income applicable to common shareholders (1)	$	5,461	$	4,678	$	2,012
Denominator:
Weighted average common shares outstanding	311.6		328.2		347.8
Effect of dilutive potential common shares:
Stock options	2.2		3.2		3.6
Restricted stock units (non-participating) and performance stock awards	1.7		2.1		1.8
Weighted average common and dilutive potential common shares outstanding	315.5		333.5		353.2
Earnings per common share – Basic	$	17.53	$	14.25	$	5.78
Earnings per common share – Diluted	$	17.31	$	14.03	$	5.70
Anti-dilutive options excluded from diluted earnings per common share	2.9		3.7		2.0