CONSOLIDATED STATEMENT OF INCOME (LOSS) (UNAUDITED) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Interest income:
Loans		$ 451	$ 638
Securities		177	243
Trading securities		48	80
Short-term investments		16	87
Other		9	19
Total interest income		701	1,067
Interest expense:
Deposits		81	321
Short-term borrowings		5	40
Long-term debt		82	198
Other		2	4
Total interest expense		170	563
Net interest income		531	504
Provision for credit losses		(227)	726
Net interest income (expense) after provision for credit losses		758	(222)
Other revenues:
Other revenues		288	283
Trading revenue		41	14
Other securities gains, net		29	28
Gain (loss) on instruments designated at fair value and related derivatives		18	(22)
Other income		9	86
Total other revenues	[1]	384	387
Operating expenses:
Salaries and employee benefits		176	207
Support services from HSBC affiliates		367	382
Occupancy expense, net		30	140
Goodwill impairment		0	784
Other expenses		109	92
Total operating expenses		682	1,605
Income (loss) before income tax		460	(1,440)
Income tax expense (benefit)		121	(157)
Net income (loss)		339	(1,283)
Credit card fees, net [Member]
Other revenues:
Other revenues		10	11
Trust and investment management fees [Member]
Other revenues:
Other revenues		29	31
Other fees and commissions [Member]
Other revenues:
Other revenues		165	151
Servicing and other fees from HSBC affiliates [Member]
Other revenues:
Other revenues		$ 83	$ 88

[1] See Note 15, "Business Segments," for a reconciliation of total other revenues on a U.S. GAAP basis to other operating income for each business segment under the Group Reporting Basis.