Segment Reporting - Core Earnings Adjustments to GAAP (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Adjustments Required To Reconcile Core Earnings [Line Items]
Net Income (Loss)	$ 14	$ 36	$ 11	$ 109
Net tax effect	(4)	(12)	(1)	(27)
Operating Segments [Member]
Adjustments Required To Reconcile Core Earnings [Line Items]
Net Income (Loss)	21	33	47	86
Net tax effect	(6)	(10)	(14)	(26)
Total Adjustments [Member] | Adjustments [Member]
Adjustments Required To Reconcile Core Earnings [Line Items]
Net Income (Loss)	7	(3)	36	(23)
Core Earnings adjustments to GAAP	9	(5)	49	(24)
Net tax effect	(2)	2	(13)	1
Net Impact of Derivative Accounting [Member] | Total Adjustments [Member] | Adjustments [Member]
Adjustments Required To Reconcile Core Earnings [Line Items]
Core Earnings adjustments to GAAP	8	(8)	47	(29)
Net Impact of Goodwill and Acquired Intangible Assets [Member] | Total Adjustments [Member] | Adjustments [Member]
Adjustments Required To Reconcile Core Earnings [Line Items]
Core Earnings adjustments to GAAP	$ 1	$ 3	$ 2	$ 5