Shareholders' Equity - Progression of the components of accumulated other comprehensive income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Accumulated Other Comprehensive Income [Roll Forward]
Other comprehensive income (loss), pretax	$ 77	$ 5
Other comprehensive income (loss), tax	(16)	(1)
Other comprehensive income, net of tax	61	4
Net unrealized gains (losses) on securities:
Unrealized holding gains (losses) on securities arising during the period, pretax	69	6
Unrealized holding gains (losses) on securities arising during the period, tax	(14)	(1)
Unrealized holding gains (losses) on securities arising during the period, after tax	55	5
Reclassification adjustment for realized (gains) losses included in net earnings, pretax	7	5
Reclassification adjustment for realized (gains) losses included in net earnings, tax	(1)	(1)
Reclassification adjustment for realized (gains) losses included in net earnings, after tax	6	4
Total net unrealized gains (losses) on securities, pretax	76	11
Total net unrealized gains (losses) on securities, tax	(15)	(2)
Total net unrealized gains (losses) on securities	61	9
Net unrealized gains (losses) on cash flow hedges:
Unrealized holding gains (losses) on cash flow hedges arising during the period, pretax	1	(13)
Unrealized holding gains (losses) on cash flow hedges arising during the period, tax	0	3
Unrealized holding gains (losses) on cash flow hedges arising during the period, after tax	1	(10)
Reclassification adjustment for investment income included in net earnings, pretax	3	7
Reclassification adjustment for investment income included in net earnings, tax	(1)	(2)
Reclassification adjustment for investment income included in net earnings from discontinued operations, after tax	2	5
Total net unrealized gains (losses) on cash flow hedges, pretax	4	(6)
Total net unrealized gains (losses) on cash flow hedges, tax	(1)	1
Total net unrealized gains (losses) on cash flow hedges	3	(5)
Foreign currency translation adjustments, pretax	(3)	0
Foreign currency translation adjustments, tax	0	0
Foreign currency translation adjustments, after tax	(3)	0
Total pension and OPRP adjustments, pretax	0	0
Total pension and OPRP adjustments, tax	0	0
Total pension and OPRP adjustments, after Tax	0	0
AOCI attributable to parent
Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(240)	(319)
Ending Balance	(179)	(315)
Accumulated net investment gain (loss) attributable to parent
Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(202)	(287)
Ending Balance	(141)	(278)
Accumulated gain (loss), net, cash flow hedge, parent
Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(10)	(17)
Ending Balance	(7)	(22)
Accumulated foreign currency adjustment attributable to parent
Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(30)	(17)
Ending Balance	(33)	(17)
Accumulated defined benefit plans adjustment attributable to parent
Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	2	2
Ending Balance	$ 2	$ 2