Guarantees and Contingent Liabilities (Details)	9 Months Ended
	Sep. 30, 2021 USD ($) claims
Holland Hewitt v. Allstate Life Insurance Company
Proceedings:
Number of putative class actions | claims	2
Minimum
Proceedings:
Loss contingencies, reasonably possible pretax loss exposure in excess of the amount accrued	$ 0
Maximum
Proceedings:
Loss contingencies, reasonably possible pretax loss exposure in excess of the amount accrued	$ 85,000,000