Shareholders' Equity - OCI Components (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pretax
Total other comprehensive income (loss)	$ (206)	$ 717
Income Tax Benefit (Expense)
Total other comprehensive income (loss)	42	(156)
Net of Tax
Arising during the period	(164)	563
Reclassification to net income		(2)
Total other comprehensive income (loss), net of tax	(164)	561
Net unrealized gains (losses) on securities
Pretax
Total other comprehensive income (loss)	(228)	551
Income Tax Benefit (Expense)
Total other comprehensive income (loss)	50	(121)
Net of Tax
Arising during the period	(178)	432
Reclassification to net income		(2)
Total other comprehensive income (loss), net of tax	(178)	430
Net unrealized gains (losses) on securities arising during the period
Pretax
Arising during the period	(236)	566
Income Tax Benefit (Expense)
Arising during the period	52	(124)
Net of Tax
Arising during the period	(184)	442
Reclassification of net (gains) losses on securities included in net income
Pretax
Reclassification to net income	0	(3)
Income Tax Benefit (Expense)
Reclassification to net income	0	1
Net of Tax
Reclassification to net income	0	(2)
Impact of benefit reserves and reinsurance recoverables
Pretax
Arising during the period	8	(12)
Income Tax Benefit (Expense)
Arising during the period	(2)	2
Net of Tax
Arising during the period	6	(10)
Net unrealized gains (losses) on derivatives
Pretax
Arising during the period	0	3
Total other comprehensive income (loss)	0	3
Income Tax Benefit (Expense)
Arising during the period	0	(1)
Total other comprehensive income (loss)	0	(1)
Net of Tax
Arising during the period	0	2
Reclassification to net income		0
Total other comprehensive income (loss), net of tax	0	2
Effect of changes in discount rate assumptions on certain long-duration contracts
Pretax
Total other comprehensive income (loss)	88	(83)
Income Tax Benefit (Expense)
Total other comprehensive income (loss)	(19)	18
Net of Tax
Arising during the period	69	(65)
Reclassification to net income		0
Total other comprehensive income (loss), net of tax	69	(65)
Effect of changes in instrument-specific credit risk on MRBs
Pretax
Total other comprehensive income (loss)	(48)	204
Income Tax Benefit (Expense)
Total other comprehensive income (loss)	11	(43)
Net of Tax
Arising during the period	(37)	161
Reclassification to net income		0
Total other comprehensive income (loss), net of tax	(37)	161
Foreign currency translation
Pretax
Total other comprehensive income (loss)	(18)	42
Income Tax Benefit (Expense)
Total other comprehensive income (loss)	0	(9)
Net of Tax
Arising during the period	(18)	33
Reclassification to net income		0
Total other comprehensive income (loss), net of tax	$ (18)	$ 33