Segment Reporting - Segment Result and Reconciliations to GAAP - Core Earnings Adjustments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income (loss) after provisions for loan losses	$ 1,042	$ 1,393	$ 1,097
Total other income (loss)	616	806	430
Goodwill and acquired intangible asset impairment and amortization	19	30	22
Income tax expense (benefit)	182	219	120
Net income	645	717	412
Total Adjustments [Member] | Adjustments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income (loss) after provisions for loan losses	95	184	(9)
Total other income (loss)	171	51	(256)
Goodwill and acquired intangible asset impairment and amortization	19	30	22
Total Core Earnings adjustments to GAAP	247	205	(287)
Income tax expense (benefit)	60	39	(68)
Net income	187	166	(219)
Net Impact of Goodwill and Acquired Intangible Assets [Member] | Total Adjustments [Member] | Adjustments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Goodwill and acquired intangible asset impairment and amortization	19	30	22
Total Core Earnings adjustments to GAAP	(19)	(30)	(22)
Net Impact of Derivative Accounting [Member] | Total Adjustments [Member] | Adjustments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income (loss) after provisions for loan losses	95	184	(9)
Total other income (loss)	171	51	(256)
Total Core Earnings adjustments to GAAP	$ 266	$ 235	$ (265)