Shareholders' Equity - Progression of the components of accumulated other comprehensive income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Accumulated Other Comprehensive Income [Roll Forward]
AOCI beginning balance	$ (319)
Other comprehensive income (loss), pretax	104	$ 283	$ (839)
Other comprehensive income (loss), tax	(25)	(59)	177
Other comprehensive income (loss)	79	224	(662)
AOCI ending balance	(240)	(319)
Net unrealized gains (losses) on securities:
Unrealized holding gains (losses) on securities arising during the period, pretax	77	224	(821)
Unrealized holding gains (losses) on securities arising during the period, tax	(16)	(48)	174
Unrealized holding gains (losses) on securities arising during the period, after tax	(61)	(176)	647
Reclassification adjustment for realized (gains) losses included in net earnings, pretax	31	43	18
Reclassification adjustment for realized (gains) losses included in net earnings, tax	(7)	(9)	(4)
Reclassification adjustment for realized (gains) losses included in net earnings, after tax	24	34	14
Total net unrealized gains (losses) on securities, pretax	108	267	(803)
Total net unrealized gains (losses) on securities, tax	(23)	(57)	170
Total net unrealized gains (losses) on securities	85	210	(633)
Reclassification of Cash Flow Hedge Gain (Loss) [Abstract]
Unrealized holding gains (losses) on cash flow hedges arising during the period, pretax	(16)	(11)	(37)
Unrealized holding gains (losses) on cash flow hedges arising during the period, tax	4	2	8
Unrealized holding gains (losses) on cash flow hedges arising during the period, after tax	(12)	(9)	(29)
Reclassification adjustment for investment income included in net earnings from, pretax	24	26	0
Reclassification adjustment for investment income included in net earnings, tax	(5)	(5)	0
Reclassification adjustment for investment income included in net earnings from discontinued operations, after tax	19	21	0
Total net unrealized gains (losses) on cash flow hedges, pretax	8	15	(37)
Total net unrealized gains (losses) on cash flow hedges, tax	(1)	(3)	8
Total net unrealized gains (losses) on cash flow hedges	7	12	(29)
Foreign currency translation adjustments, pretax	(12)	2	(1)
Foreign currency translation adjustments, tax	(1)	1	(1)
Foreign currency translation adjustments	(13)	3	(2)
Pension and other postretirement plan adjustments, pretax	0	(1)	2
Pension and other postretirement plan adjustments, tax	0	0	0
Pension and other postretirement plan adjustments	0	(1)	2
Accumulated net investment gain (loss) attributable to parent
Accumulated Other Comprehensive Income [Roll Forward]
AOCI beginning balance	(287)	(497)	136
AOCI ending balance	(202)	(287)	(497)
Accumulated net gain (loss) on cash flow hedges attributable to parent
Accumulated Other Comprehensive Income [Roll Forward]
AOCI beginning balance	(17)	(29)	0
AOCI ending balance	(10)	(17)	(29)
Accumulated foreign currency adjustment attributable to parent
Accumulated Other Comprehensive Income [Roll Forward]
AOCI beginning balance	(17)	(20)	(18)
AOCI ending balance	(30)	(17)	(20)
Accumulated defined benefit plans adjustment attributable to parent
Accumulated Other Comprehensive Income [Roll Forward]
AOCI beginning balance	2	3	1
AOCI ending balance	2	2	3
AOCI attributable to parent
Accumulated Other Comprehensive Income [Roll Forward]
AOCI beginning balance	(319)	(543)	119
Other comprehensive income (loss)	79	224	(662)
AOCI ending balance	$ (240)	$ (319)	$ (543)