Shareholders' Equity - Progression of the components of accumulated other comprehensive income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Accumulated Other Comprehensive Income [Roll Forward]
AOCI beginning balance			$ (543)
Other comprehensive income (loss), pretax	$ (73)	$ (319)	(33)	$ (912)
Other comprehensive income (loss), tax	14	65	6	191
Other comprehensive income (loss)	(59)	(254)	(27)	(721)
AOCI ending balance	(570)		(570)
Net unrealized gains (losses) on securities:
Unrealized holding gains (losses) on securities arising during the period, pretax	(81)	(292)	(69)	(884)
Unrealized holding gains (losses) on securities arising during the period, tax	17	61	14	186
Unrealized holding gains (losses) on securities arising during the period, after tax	(64)	(231)	(55)	(698)
Reclassification adjustment for realized (gains) losses included in net earnings, pretax	9	4	40	10
Reclassification adjustment for realized (gains) losses included in net earnings, tax	(2)	(1)	(9)	(2)
Reclassification adjustment for realized (gains) losses included in net earnings, after tax	7	3	31	8
Total net unrealized gains (losses) on securities, pretax	(72)	(288)	(29)	(874)
Total net unrealized gains (losses) on securities, tax	15	60	5	184
Total net unrealized gains (losses) on securities	(57)	(228)	(24)	(690)
Reclassification of Cash Flow Hedge Gain (Loss) [Abstract]
Unrealized holding gains (losses) on cash flow hedges arising during the period, pretax	(9)	(26)	(25)	(34)
Unrealized holding gains (losses) on cash flow hedges arising during the period, tax	2	5	5	7
Unrealized holding gains (losses) on cash flow hedges arising during the period, after tax	(7)	(21)	(20)	(27)
Reclassification adjustment for investment income included in net earnings, pretax	8	(1)	19	(3)
Reclassification adjustment for investment income included in net earnings, tax	(2)	1	(4)	1
Reclassification adjustment for investment income included in net earnings from discontinued operations, after tax	6	0	15	(2)
Total net unrealized gains (losses) on cash flow hedges, pretax	(1)	(27)	(6)	(37)
Total net unrealized gains (losses) on cash flow hedges, tax	0	6	1	8
Total net unrealized gains (losses) on cash flow hedges	(1)	(21)	(5)	(29)
Foreign currency translation adjustments, pretax	0	(4)	2	(1)
Foreign currency translation adjustments, tax	(1)	(1)	0	(1)
Foreign currency translation adjustments	(1)	(5)	2	(2)
Total pension and OPRP adjustments, pretax	0	0	0	0
Total pension and OPRP adjustments, tax	0	0	0	0
Pension and OPRP adjustments	0	0	0	0
Accumulated net investment gain (loss) attributable to parent
Accumulated Other Comprehensive Income [Roll Forward]
AOCI beginning balance	(464)	(326)	(497)	136
AOCI ending balance	(521)	(554)	(521)	(554)
Accumulated gain (loss), net, cash flow hedge, parent
Accumulated Other Comprehensive Income [Roll Forward]
AOCI beginning balance	(33)	(8)	(29)	0
AOCI ending balance	(34)	(29)	(34)	(29)
Accumulated foreign currency adjustment attributable to parent
Accumulated Other Comprehensive Income [Roll Forward]
AOCI beginning balance	(17)	(15)	(20)	(18)
AOCI ending balance	(18)	(20)	(18)	(20)
Accumulated defined benefit plans adjustment attributable to parent
Accumulated Other Comprehensive Income [Roll Forward]
AOCI beginning balance	3	1	3	1
AOCI ending balance	3	1	3	1
AOCI attributable to parent
Accumulated Other Comprehensive Income [Roll Forward]
AOCI beginning balance	(511)	(348)	(543)	119
AOCI ending balance	$ (570)	$ (602)	$ (570)	$ (602)