Deferred Policy Acquisition Costs - Rollforward of DAC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Balance, beginning of year	$ 12,857	$ 13,001	$ 12,955
Capitalization	5,419	4,722	4,729
Amortization expense	(4,808)	(4,557)	(4,524)
Other, including foreign exchange	9	(309)	(159)
Dispositions	(578)
Reclassified to held for sale	(814)
Balance, end of year	12,085	12,857	13,001
General Insurance
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Balance, beginning of year	2,310	2,428	2,489
Capitalization	4,135	3,648	3,658
Amortization expense	(3,747)	(3,536)	(3,566)
Other, including foreign exchange	(45)	(230)	(153)
Dispositions	(578)
Reclassified to held for sale	0
Balance, end of year	2,075	2,310	2,428
Life and Retirement | Individual Retirement
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Balance, beginning of year	4,597	4,553	4,421
Capitalization	705	562	579
Amortization expense	(567)	(519)	(447)
Other, including foreign exchange	0	1	0
Dispositions	0
Reclassified to held for sale	0
Balance, end of year	4,735	4,597	4,553
Life and Retirement | Group Retirement
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Balance, beginning of year	1,060	1,078	1,094
Capitalization	78	62	62
Amortization expense	(82)	(80)	(78)
Other, including foreign exchange	0	0	0
Dispositions	0
Reclassified to held for sale	0
Balance, end of year	1,056	1,060	1,078
Life and Retirement | Life Insurance
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Balance, beginning of year	4,839	4,904	4,918
Capitalization	473	429	420
Amortization expense	(403)	(415)	(427)
Other, including foreign exchange	54	(79)	(7)
Dispositions	0
Reclassified to held for sale	(814)
Balance, end of year	4,149	4,839	4,904
Life and Retirement | Institutional Markets
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Balance, beginning of year	51	38	33
Capitalization	28	21	10
Amortization expense	(9)	(7)	(6)
Other, including foreign exchange	0	(1)	1
Dispositions	0
Reclassified to held for sale	0
Balance, end of year	$ 70	$ 51	$ 38