CONSOLIDATED STATEMENT OF INCOME (LOSS) (UNAUDITED) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Interest income:
Loans		$ 416	$ 511	$ 1,308	$ 1,729
Securities		154	202	491	707
Trading securities		60	64	162	192
Short-term investments		24	16	57	126
Other		4	11	17	35
Total interest income		658	804	2,035	2,789
Interest expense:
Deposits		60	135	210	656
Short-term borrowings		4	7	13	62
Long-term debt		70	111	230	471
Other		4	3	8	10
Total interest expense		138	256	461	1,199
Net interest income		520	548	1,574	1,590
Provision for credit losses		(81)	(105)	(537)	840
Net interest income after provision for credit losses		601	653	2,111	750
Other revenues:
Other revenues		267	269	837	814
Trading revenue (expense)		(42)	49	1	255
Other securities gains, net		4	52	51	111
Gain on instruments designated at fair value and related derivatives		8	15	33	15
Other income (loss)		7	(27)	13	18
Total other revenues	[1]	242	356	930	1,207
Operating expenses:
Salaries and employee benefits		151	193	509	590
Support services from HSBC affiliates		389	391	1,148	1,162
Occupancy expense, net		27	44	175	222
Goodwill impairment		0	0	0	784
Other expenses		99	157	318	359
Total operating expenses		666	785	2,150	3,117
Income (loss) before income tax		177	224	891	(1,160)
Income tax expense (benefit)		40	36	222	(72)
Net income (loss)		137	188	669	(1,088)
Credit card fees, net [Member]
Other revenues:
Other revenues		0	10	23	30
Trust and investment management fees [Member]
Other revenues:
Other revenues		26	34	81	98
Other fees and commissions [Member]
Other revenues:
Other revenues		160	144	496	425
Servicing and other fees from HSBC affiliates [Member]
Other revenues:
Other revenues		$ 79	$ 79	$ 232	$ 255

[1] See Note 16, "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.