Employee Benefits - Schedule of Funded Status of the Plans Reconciled to the Amount Reported in the Balance Sheets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
U.S. Plans | Pension
Change in projected benefit obligation:
Benefit obligation, beginning of year	$ 3,301	$ 3,475
Service cost	4	5	$ 6
Interest cost	154	168	109
Actuarial gain (loss)	(200)	75
AIG assets	(17)	(16)
Plan assets	(280)	(171)
Plan amendment	0	0
Settlements	0	(234)
Foreign exchange effect	0	0
Other	0	(1)
Projected benefit obligation, end of year	2,962	3,301	3,475
Change in plan assets:
Fair value of plan assets, beginning of year	3,228	3,345
Actual return on plan assets, net of expenses	28	288
AIG contributions	17	16
AIG assets	(17)	(16)
Plan assets	(280)	(171)
Settlements	0	(234)
Foreign exchange effect	0	0
Fair value of plan assets, end of year	2,976	3,228	3,345
Funded status, end of year	14	(73)
Amounts recognized in the balance sheet:
Assets	184	110
Liabilities	(170)	(183)
Total amounts recognized	14	(73)
Pre-tax amounts recognized in AOCI:
Net gain (loss)	(1,082)	(1,142)
Prior service (cost) credit	0	0
Total amounts recognized	(1,082)	(1,142)
U.S. Plans | Pension | Defined Benefit Plan, Unfunded Plan
Change in projected benefit obligation:
Benefit obligation, beginning of year	184
Projected benefit obligation, end of year	170	184
U.S. Plans | Postretirement benefit plans
Change in projected benefit obligation:
Benefit obligation, beginning of year	97	99
Service cost	0	0	1
Interest cost	4	5	3
Actuarial gain (loss)	(4)	3
AIG assets	(10)	(10)
Plan assets	0	0
Plan amendment	0	0
Settlements	0	0
Foreign exchange effect	0	0
Other	0	0
Projected benefit obligation, end of year	87	97	99
Change in plan assets:
Fair value of plan assets, beginning of year	0	0
Actual return on plan assets, net of expenses	0	0
AIG contributions	10	10
AIG assets	(10)	(10)
Plan assets	0	0
Settlements	0	0
Foreign exchange effect	0	0
Fair value of plan assets, end of year	0	0	0
Funded status, end of year	(87)	(97)
Amounts recognized in the balance sheet:
Assets	0	0
Liabilities	(87)	(97)
Total amounts recognized	(87)	(97)
Pre-tax amounts recognized in AOCI:
Net gain (loss)	28	28
Prior service (cost) credit	0	0
Total amounts recognized	28	28
Foreign Plan | Pension
Change in projected benefit obligation:
Benefit obligation, beginning of year	804	810
Service cost	14	16	18
Interest cost	20	20	9
Actuarial gain (loss)	14	(8)
AIG assets	(9)	(10)
Plan assets	(28)	(31)
Plan amendment	1	(1)
Settlements	(9)	(1)
Foreign exchange effect	(60)	9
Other	0	0
Projected benefit obligation, end of year	747	804	810
Change in plan assets:
Fair value of plan assets, beginning of year	734	709
Actual return on plan assets, net of expenses	35	15
AIG contributions	42	47
AIG assets	(9)	(10)
Plan assets	(28)	(31)
Settlements	(9)	(1)
Foreign exchange effect	(61)	5
Fair value of plan assets, end of year	704	734	709
Funded status, end of year	(43)	(70)
Amounts recognized in the balance sheet:
Assets	122	97
Liabilities	(165)	(167)
Total amounts recognized	(43)	(70)
Pre-tax amounts recognized in AOCI:
Net gain (loss)	(72)	(79)
Prior service (cost) credit	(18)	(21)
Total amounts recognized	(90)	(100)
Foreign Plan | Pension | Defined Benefit Plan, Unfunded Plan
Change in projected benefit obligation:
Benefit obligation, beginning of year	140
Projected benefit obligation, end of year	139	140
Foreign Plan | Postretirement benefit plans
Change in projected benefit obligation:
Benefit obligation, beginning of year	31	32
Service cost	0	0	0
Interest cost	2	2	1
Actuarial gain (loss)	0	(2)
AIG assets	(1)	(1)
Plan assets	0	0
Plan amendment	0	0
Settlements	0	0
Foreign exchange effect	(2)	0
Other	0	0
Projected benefit obligation, end of year	30	31	32
Change in plan assets:
Fair value of plan assets, beginning of year	0	0
Actual return on plan assets, net of expenses	0	0
AIG contributions	1	1
AIG assets	(1)	(1)
Plan assets	0	0
Settlements	0	0
Foreign exchange effect	0	0
Fair value of plan assets, end of year	0	0	$ 0
Funded status, end of year	(30)	(31)
Amounts recognized in the balance sheet:
Assets	0	0
Liabilities	(30)	(31)
Total amounts recognized	(30)	(31)
Pre-tax amounts recognized in AOCI:
Net gain (loss)	21	23
Prior service (cost) credit	0	1
Total amounts recognized	$ 21	$ 24