Lending Activities - Credit quality of commercial mortgages (Details) $ in Millions	Sep. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Commercial mortgage loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	$ 1,722	$ 6,473
Prior year	6,903	3,355
Two years prior	3,831	2,206
Three years prior	1,712	5,453
Four years prior	5,334	5,431
Five years & beyond prior	18,494	14,210
Total	$ 37,996	$ 37,128
Weighted average debt service coverage ratio	1.9	1.9
Weighted average loan-to-value ratio (as a percent)	59.00%	59.00%
Commercial mortgage loans | >90 days delinquent or in process of foreclosure(a)
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 197	$ 215
Commercial mortgage loans | Fortitude RE Funds Withheld Assets | >90 days delinquent or in process of foreclosure(a)
Financing Receivable, Credit Quality Indicator [Line Items]
Total	157	156
AIG Financial Products
Financing Receivable, Credit Quality Indicator [Line Items]
Total	37,600	37,600
Less than 65% | Commercial mortgage loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	1,546	5,425
Prior year	4,588	2,548
Two years prior	2,871	1,775
Three years prior	1,254	3,958
Four years prior	3,789	3,016
Five years & beyond prior	12,601	10,739
Total	26,649	27,461
65% to 75% | Commercial mortgage loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	176	998
Prior year	1,701	517
Two years prior	619	405
Three years prior	239	1,445
Four years prior	1,495	1,487
Five years & beyond prior	3,821	1,393
Total	8,051	6,245
76% to 80% | Commercial mortgage loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	50
Prior year	564	52
Two years prior	52	0
Three years prior	0	0
Four years prior	0	168
Five years & beyond prior	171	229
Total	787	499
Greater than 80% | Commercial mortgage loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Prior year	50	238
Two years prior	289	26
Three years prior	219	50
Four years prior	50	760
Five years & beyond prior	1,901	1,849
Total	2,509	2,923
Greater than 1.2X | Commercial mortgage loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	1,612	5,518
Prior year	5,790	2,457
Two years prior	2,354	1,710
Three years prior	1,362	4,985
Four years prior	5,091	4,120
Five years & beyond prior	14,822	11,663
Total	31,031	30,453
1.00 - 1.20X | Commercial mortgage loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	110	910
Prior year	1,065	898
Two years prior	1,477	473
Three years prior	350	416
Four years prior	243	567
Five years & beyond prior	2,667	1,353
Total	5,912	4,617
Less than 1.00X | Commercial mortgage loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	45
Prior year	48	0
Two years prior	0	23
Three years prior	0	52
Four years prior	0	744
Five years & beyond prior	1,005	1,194
Total	$ 1,053	$ 2,058