HSBC USA (HUSI+G) 10-Q 28 Apr 20 2020 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	Apr. 24, 2020
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Registrant Name	HSBC USA INC /MD/
Entity Central Index Key	0000083246
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		714
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Zero Coupon Callable Accreting Notes due January 15, 2043 [Member]
Entity Information [Line Items]
Trading Symbol	HBA/43
Zero Coupon Callable Accreting Notes due January 29, 2043 [Member]
Entity Information [Line Items]
Trading Symbol	HBA/43A

CONSOLIDATED STATEMENT OF INCOM

CONSOLIDATED STATEMENT OF INCOME (LOSS) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Interest income:
Loans		$ 638	$ 716
Securities		243	304
Trading securities		80	63
Short-term investments		87	176
Other		19	18
Total interest income		1,067	1,277
Interest expense:
Deposits		321	333
Short-term borrowings		40	62
Long-term debt		198	312
Other		4	8
Total interest expense		563	715
Net interest income		504	562
Provision for credit losses		726
Provision for credit losses		512	58
Net interest income (expense) after provision for credit losses		(222)	504
Other revenues:
Other revenues		283	272
Trading revenue		14	133
Other securities gains, net		28	7
Loss on instruments designated at fair value and related derivatives		(22)	(9)
Other income (loss)		86	(11)
Total other revenues	[1]	387	390
Operating expenses:
Salaries and employee benefits		207	210
Support services from HSBC affiliates		382	380
Occupancy expense, net		140	45
Goodwill impairment		784	0
Other expenses		92	115
Total operating expenses		1,605	750
Income (loss) before income tax		(1,440)	144
Income tax expense (benefit)		(157)	35
Net income (loss)		(1,283)	109
Credit card fees, net [Member]
Other revenues:
Other revenues		11	12
Trust and investment management fees [Member]
Other revenues:
Other revenues		31	30
Other fees and commissions [Member]
Other revenues:
Other revenues		151	147
Servicing and other fees from HSBC affiliates [Member]
Other revenues:
Other revenues		$ 88	$ 81
[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.

CONSOLIDATED STATEMENT OF COMPR

CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (1,283)	$ 109
Net change in unrealized gains (losses), net of tax:
Investment securities	758	179
Fair value option liabilities attributable to our own credit spread	407	(111)
Derivatives designated as cash flow hedges	90	14
Pension and post-retirement benefit plans	0	(3)
Total other comprehensive income	1,255	79
Comprehensive income (loss)	$ (28)	$ 188

CONSOLIDATED BALANCE SHEET

CONSOLIDATED BALANCE SHEET - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Assets:
Cash and due from banks		$ 983	$ 1,744
Interest bearing deposits with banks		26,496	2,038
Federal funds sold and securities purchased under agreements to resell		4,643	17,838
Trading assets (includes $6.6 billion and $336 million pledged to creditors at March 31, 2020 and December 31, 2019, respectively)		29,217	28,452
Securities available-for-sale (includes $7.8 billion and nil pledged to creditors at March 31, 2020 and December 31, 2019, respectively, and an allowance for credit losses of $2 million at March 31, 2020)		40,792	35,663
Securities held-to-maturity, net of allowance for credit losses of $2 million at March 31, 2020 (fair value of $13.4 billion at both March 31, 2020 and December 31, 2019)		12,981	13,293
Loans (includes $37 million designated under fair value option at March 31, 2020)		81,728	68,553
Less – allowance for credit losses		931	637
Loans, net		80,797	67,916
Loans held for sale (includes $206 million and $178 million designated under fair value option at March 31, 2020 and December 31, 2019, respectively)		285	289
Properties and equipment, net		153	177
Goodwill		458	1,242
Other assets, net of allowance for credit losses of $5 million at March 31, 2020		8,272	6,723
Total assets	[1]	205,077	175,375
Domestic deposits:
Noninterest bearing		28,265	24,132
Interest bearing (includes $6.4 billion and $7.2 billion designated under fair value option at March 31, 2020 and December 31, 2019, respectively)		99,724	90,766
Foreign deposits:
Noninterest bearing		189	137
Interest bearing		8,545	4,658
Total deposits		136,723	119,693
Short-term borrowings (includes nil and $373 million designated under fair value option at March 31, 2020 and December 31, 2019, respectively)		17,579	3,659
Long-term debt (includes $8.4 billion and $10.3 billion designated under fair value option at March 31, 2020 and December 31, 2019, respectively)		24,777	26,697
Total debt		179,079	150,049
Trading liabilities		3,923	3,235
Interest, taxes and other liabilities		3,756	3,835
Total liabilities	[1]	186,758	157,119
Equity
Preferred stock (no par value; 40,999,000 shares authorized; 1,265 shares issued and outstanding at both March 31, 2020 and December 31, 2019)		1,265	1,265
Common equity:
Common stock ($5 par; 150,000,000 shares authorized; 714 shares issued and outstanding at both March 31, 2020 and December 31, 2019)		0	0
Additional paid-in capital		15,741	15,736
Retained earnings		335	1,534
Accumulated other comprehensive income (loss)		978	(279)
Total common equity		17,054	16,991
Total equity		18,319	18,256
Total liabilities and equity		$ 205,077	$ 175,375
[1]	The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at March 31, 2020 and December 31, 2019 which are consolidated on our balance sheet. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 17, "Variable Interest Entities," for additional information. Assets: Loans $39 million and $0 million. Other assets $92 million and $98 million. Total assets $131 million and $98 million respectively. Liabilities: Interest, taxes and other liabilities $32 million and $38 million. Total liabilities $32 million and $38 million, respectively.

CONSOLIDATED BALANCE SHEET (Par

CONSOLIDATED BALANCE SHEET (Parenthetical) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Assets pledged to creditors, trading assets	[1]	$ 6,633	$ 525
Securities available-for-sale, allowance for credit losses	[2],[3]	2
Securities held-to-maturity, fair value		13,446	$ 13,431
Securities held-to-maturity, allowance for credit losses	[2],[3]	2
Other assets, allowance for credit losses	[4]	$ 5
Preferred stock, par value (usd per share)		$ 0	$ 0
Preferred stock, shares authorized (shares)		40,999,000	40,999,000
Preferred stock, shares issued (shares)		1,265	1,265
Preferred stock, shares outstanding (shares)		1,265	1,265
Common stock, par value (usd per share)		$ 5	$ 5
Common stock, shares authorized (shares)		150,000,000	150,000,000
Common stock, shares issued (shares)		714	714
Common stock, shares outstanding (shares)		714	714
Assets:
Loans		$ 81,728	$ 68,553
Other assets		8,272	6,723
Total assets	[5]	205,077	175,375
Liabilities:
Long-term debt		24,777	26,697
Interest, taxes and other liabilities		3,756	3,835
Total liabilities	[5]	186,758	157,119
Student Loan [Member]
Loans, designated under fair value option		37
Loans Held For Sale [Member]
Loans Held-for-sale, designated under fair value option		206	178
Deposits [Member]
Deposits designated under fair value option		6,400	7,200
Short-term Borrowings [Member]
Short-term borrowings designated under fair value option		0	373
Long-term debt [Member]
Long-term debt designated under fair value option		8,400	10,300
Trading assets [Member]
Assets pledged to creditors, trading assets		6,633	336
Securities available-for-sale [Member]
Assets pledged to creditors, securities-available-for-sale		7,760	0
Variable interest entities [Member]
Assets:
Loans		39	0
Other assets		92	98
Total assets		131	98
Liabilities:
Interest, taxes and other liabilities		32	38
Total liabilities		$ 32	$ 38
[1]	Trading assets are primarily pledged against liabilities associated with repurchase agreements.
[2]	As discussed in Note 21, "New Accounting Pronouncements," beginning January 1, 2020, an allowance for credit losses is recognized for debt securities while, prior to January 1, 2020, debt securities were assessed for other-than-temporary impairment. At December 31, 2019, we did not consider any of our debt securities to be other-than-temporarily impaired
[3]	See Note 4, "Securities," for additional information regarding the allowance for credit losses associated with our security portfolios.
[4]	Primarily includes accrued interest receivables and customer acceptances.
[5]	The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at March 31, 2020 and December 31, 2019 which are consolidated on our balance sheet. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 17, "Variable Interest Entities," for additional information. Assets: Loans $39 million and $0 million. Other assets $92 million and $98 million. Total assets $131 million and $98 million respectively. Liabilities: Interest, taxes and other liabilities $32 million and $38 million. Total liabilities $32 million and $38 million, respectively.

CONSOLIDATED STATEMENT OF CHANG

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - USD ($) $ in Millions	Total		Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	As Previously Reported [Member]Retained Earnings [Member]	As Previously Reported [Member]Accumulated Other Comprehensive Loss [Member]	Student Loan [Member]Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of new accounting principle in period of adoption | Accounting Standards Update 2016-13 [Member]	$ 0	[1]				$ 0				$ 0
Cumulative effect of new accounting principle in period of adoption | Accounting Standards Update 2016-02 [Member]						27
Cumulative effect of new accounting principle in period of adoption, reclassification | Accounting Standards Update 2016-13 [Member]						0	$ 0
Balance at beginning of period at Dec. 31, 2018			$ 1,265
Balance at beginning of period at Dec. 31, 2018				$ 0	$ 18,136	1,498	(366)	$ 1,471	$ (366)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Return of capital to parent					(2,400)
Employee benefit plans					0
Net income (loss)	109					109
Other comprehensive income, net of tax	79						79
Balance at end of period at Mar. 31, 2019	17,056			0	15,736	1,607	(287)
Balance at end of period at Mar. 31, 2019	18,321		1,265
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of new accounting principle in period of adoption	(170)
Cumulative effect of new accounting principle in period of adoption | Accounting Standards Update 2016-13 [Member]	2	[1]				84				$ 2
Cumulative effect of new accounting principle in period of adoption | Accounting Standards Update 2016-02 [Member]						0
Cumulative effect of new accounting principle in period of adoption, reclassification | Accounting Standards Update 2016-13 [Member]						(2)	2
Balance at beginning of period at Dec. 31, 2019	18,256		1,265
Balance at beginning of period at Dec. 31, 2019	16,991			0	15,736	1,618	(277)	$ 1,534	$ (279)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Return of capital to parent					0
Employee benefit plans					5
Net income (loss)	(1,283)					(1,283)
Other comprehensive income, net of tax	1,255						1,255
Balance at end of period at Mar. 31, 2020	17,054			$ 0	$ 15,741	$ 335	$ 978
Balance at end of period at Mar. 31, 2020	$ 18,319		$ 1,265
[1]	See Note 21, "New Accounting Pronouncements," for additional discussion.

CONSOLIDATED STATEMENT OF CASH

CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities
Net income (loss)	$ (1,283)	$ 109
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	77	11
Goodwill impairment	784	0
Provision for credit losses	726
Provision for credit losses	512	58
Net realized gains on securities available-for-sale	(28)	(7)
Net change in other assets and liabilities	(4,613)	1,326
Net change in loans held for sale:
Originations and purchases of loans held for sale	(1,239)	(593)
Sales and collections of loans held for sale	1,184	621
Net change in trading assets and liabilities	(77)	(3,858)
Lower of amortized cost or fair value adjustments on loans held for sale	(1)	0
Loss on instruments designated at fair value and related derivatives	22	9
Net cash used in operating activities	(4,448)	(2,324)
Cash flows from investing activities
Net change in federal funds sold and securities purchased under agreements to resell	13,195	3,244
Securities available-for-sale:
Purchases of securities available-for-sale	(9,918)	(4,408)
Proceeds from sales of securities available-for-sale	4,630	2,145
Proceeds from maturities of securities available-for-sale	2,295	2,123
Securities held-to-maturity:
Purchases of securities held-to-maturity	(515)	(229)
Proceeds from maturities of securities held-to-maturity	817	509
Change in loans:
Originations, net of collections	(13,510)	(2,413)
Loans sold to third parties	299	381
Net cash provided by disposal (used for acquisitions) of properties and equipment	7	(8)
Outflow related to the sale of a portion of our Private Banking business	0	(2)
Other, net	(213)	(1)
Net cash provided by (used in) investing activities	(2,913)	1,341
Cash flows from financing activities
Net change in deposits	14,153	2,479
Debt:
Net change in short-term borrowings	13,920	5,387
Issuance of long-term debt	5,844	1,829
Repayment of long-term debt	(2,864)	(2,091)
Return of capital to parent	0	(2,400)
Other increases in capital surplus	5	0
Net cash provided by financing activities	31,058	5,204
Net change in cash and due from banks and interest bearing deposits with banks	23,697	4,221
Cash and due from banks and interest bearing deposits with banks at beginning of period	3,782	17,214
Cash and due from banks and interest bearing deposits with banks at end of period	$ 27,479	$ 21,435

Organization

Organization	3 Months Ended
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization and Presentation HSBC USA Inc. ("HSBC USA"), incorporated under the laws of Maryland, is a New York State based bank holding company and a wholly-owned subsidiary of HSBC North America Holdings Inc. ("HSBC North America"), which is an indirect wholly-owned subsidiary of HSBC Holdings plc ("HSBC" and, together with its subsidiaries, "HSBC Group"). The accompanying unaudited interim consolidated financial statements of HSBC USA and its subsidiaries (collectively "HUSI") have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X, as well as in accordance with predominant practices within the banking industry. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all normal and recurring adjustments considered necessary for a fair presentation of financial position, results of operations and cash flows for the interim periods have been made. HUSI may also be referred to in these notes to the consolidated financial statements as "we," "us" or "our." These unaudited interim consolidated financial statements should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2019 (the "2019 Form 10-K"). Certain reclassifications have been made to prior period amounts to conform to the current period presentation. The preparation of financial statements in conformity with U.S. GAAP requires the use of estimates and assumptions that affect reported amounts and disclosures. Actual results could differ from those estimates. Interim results should not be considered indicative of results in future periods.

Strategic Initiatives

Strategic Initiatives	3 Months Ended
	Mar. 31, 2020
Restructuring and Related Activities [Abstract]
Strategic Initiatives	Strategic Initiatives As discussed in our 2019 Form 10-K, in February 2020, our Board of Directors approved a strategic plan to restructure our operations ("Restructuring Plan") in alignment with HSBC’s global strategy to refocus our wholesale operations to better serve our international corporate clients and restructure our retail operations to better meet the needs of globally mobile and affluent clients. We will also streamline our functional and operations support model by removing duplication and reduce the size of our balance sheet to better align with the scope and scale of the U.S. opportunity . We expect to incur pre-tax charges in connection with this Restructuring Plan over a two year period of approximately $350 - $400 million ( $265 - $305 million after-tax). During the first quarter of 2020, we decided to pause the vast majority of head count reductions due to the extraordinary impact of the coronavirus ("COVID-19") pandemic. However, many elements of our Restructuring Plan are moving forward as planned, including consolidation of our retail branch network and wholesale and retail middle and back office functions, and the creation of our Wealth and Personal Banking business. While we remain committed to our multi-year strategic plan to re-profile our business, the timing of the strategic actions as outlined in our 2019 Form 10-K may be re-sequenced or delayed beyond 24 months as the situation continues to develop. In light of COVID-19, we continue to reassess our strategic plan and may take additional actions in future periods. The following table summarizes the changes in the liability associated with our Restructuring Plan during the three months ended March 31, 2020: Severance and Other Employee Costs (1) Lease Termination and Associated Costs (2) Total (in millions) Three Months Ended March 31, 2020 Restructuring liability at beginning of period $ — $ — $ — Restructuring costs recorded during the period 9 24 33 Restructuring costs paid during the period — — — Restructuring liability at end of period $ 9 $ 24 $ 33 (1) Severance and other employee costs are included in salaries and employee benefits in the consolidated statement of income (loss), substantially all of which were reported in the Retail Banking & Wealth Management business segment for segment reporting purposes. (2) Primarily includes real estate taxes, service charges and decommissioning costs. Lease termination and associated costs are included in occupancy expense, net in the consolidated statement of income (loss) and were reported in the Corporate Center business segment for segment reporting purposes. In connection with the restructuring costs reflected above, during the first quarter of 2020, we determined that we would exit approximately 60 branches (in addition to the approximately 20 branches for which we disclosed plans to exit in the fourth quarter of 2019). As a result, we recorded impairment charges during the first quarter of 2020 to write down the lease ROU assets, net of estimated sublease income, by $52 million and to write down the leasehold improvement assets associated with these branches by $16 million based on their estimated remaining useful lives. These impairment charges are reflected in occupancy expense, net in the consolidated statement of income (loss) and were reported in the Corporate Center business segment for segment reporting purposes. Our Restructuring Plan also resulted in costs being allocated to us from HSBC Technology & Services ("HTSU") which are reflected in support services from HSBC affiliates in the consolidated statement of income (loss). During the three months ended March 31, 2020, we recorded $8 million of allocated costs from HTSU, primarily including contract cancellation and equipment removal charges associated with the branch exits discussed above.

Trading Assets and Liabilities

Trading Assets and Liabilities	3 Months Ended
	Mar. 31, 2020
Trading Assets And Liabilities [Abstract]
Trading Assets and Liabilities	Trading Assets and Liabilities Trading assets and liabilities consisted of the following: March 31, 2020 December 31, 2019 (in millions) Trading assets: U.S. Treasury $ 8,207 $ 6,763 U.S. Government agency issued or guaranteed 39 18 U.S. Government sponsored enterprises 21 20 Asset-backed securities 156 168 Corporate and foreign bonds 9,365 10,826 Equity securities 1,432 5,693 Precious metals 4,604 1,909 Derivatives, net 5,393 3,055 Total trading assets $ 29,217 $ 28,452 Trading liabilities: Securities sold, not yet purchased $ 434 $ 1,182 Payables for precious metals — 124 Derivatives, net 3,489 1,929 Total trading liabilities $ 3,923 $ 3,235 At March 31, 2020 and December 31, 2019 , the fair value of derivatives included in trading assets is net of $6,137 million and $2,538 million , respectively, relating to amounts recognized for the obligation to return cash collateral received under master netting agreements with derivative counterparties. At March 31, 2020 and December 31, 2019 , the fair value of derivatives included in trading liabilities is net of $8,575 million and $4,351 million , respectively, relating to amounts recognized for the right to reclaim cash collateral paid under master netting agreements with derivative counterparties. See Note 9, "Derivative Financial Instruments," for further information on our trading derivatives and related collateral.

Securities

Securities	3 Months Ended
	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Securities	Securities Our securities available-for-sale and securities held-to-maturity portfolios consisted of the following: March 31, 2020 Amortized Cost Allowance for Credit Losses (1) Unrealized Gains Unrealized Losses Fair Value (in millions) Securities available-for-sale: U.S. Treasury $ 16,893 $ — $ 607 $ (209 ) $ 17,291 U.S. Government sponsored enterprises: Mortgage-backed securities 4,697 — 219 (1 ) 4,915 Collateralized mortgage obligations 262 — 16 (1 ) 277 Direct agency obligations 1,849 — 9 (14 ) 1,844 U.S. Government agency issued or guaranteed: Mortgage-backed securities 10,214 — 276 (2 ) 10,488 Collateralized mortgage obligations 1,282 — 42 (1 ) 1,323 Direct agency obligations 290 — — (11 ) 279 Asset-backed securities collateralized by: Home equity 32 (2 ) — (2 ) 28 Other 116 — 3 (3 ) 116 Foreign debt securities (2) 4,232 — 6 (7 ) 4,231 Total available-for-sale securities $ 39,867 $ (2 ) $ 1,178 $ (251 ) $ 40,792 Securities held-to-maturity: U.S. Government sponsored enterprises: Mortgage-backed securities $ 1,561 $ — $ 53 $ — $ 1,614 Collateralized mortgage obligations 1,289 — 69 — 1,358 U.S. Government agency issued or guaranteed: Mortgage-backed securities 2,805 — 90 — 2,895 Collateralized mortgage obligations 7,316 — 255 (4 ) 7,567 Obligations of U.S. states and political subdivisions 10 (1 ) 1 — 10 Asset-backed securities collateralized by residential mortgages 2 (1 ) 1 — 2 Total held-to-maturity securities $ 12,983 $ (2 ) $ 469 $ (4 ) $ 13,446 December 31, 2019 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in millions) Securities available-for-sale: U.S. Treasury $ 16,219 $ 128 $ (269 ) $ 16,078 U.S. Government sponsored enterprises: Mortgage-backed securities 3,358 57 (13 ) 3,402 Collateralized mortgage obligations 345 3 (1 ) 347 Direct agency obligations 1,382 21 — 1,403 U.S. Government agency issued or guaranteed: Mortgage-backed securities 10,009 29 (41 ) 9,997 Collateralized mortgage obligations 741 10 (4 ) 747 Direct agency obligations 254 6 — 260 Asset-backed securities collateralized by: Home equity 34 — (2 ) 32 Other 108 3 — 111 Foreign debt securities (2) 3,282 4 — 3,286 Total available-for-sale securities $ 35,732 $ 261 $ (330 ) $ 35,663 Securities held-to-maturity: U.S. Government sponsored enterprises: Mortgage-backed securities $ 1,632 $ 22 $ (1 ) $ 1,653 Collateralized mortgage obligations 1,418 40 (4 ) 1,454 U.S. Government agency issued or guaranteed: Mortgage-backed securities 3,004 17 — 3,021 Collateralized mortgage obligations 7,227 85 (22 ) 7,290 Obligations of U.S. states and political subdivisions 10 1 — 11 Asset-backed securities collateralized by residential mortgages 2 — — 2 Total held-to-maturity securities $ 13,293 $ 165 $ (27 ) $ 13,431 (1) As discussed in Note 21, "New Accounting Pronouncements," beginning January 1, 2020, an allowance for credit losses is recognized for debt securities while, prior to January 1, 2020, debt securities were assessed for other-than-temporary impairment. At December 31, 2019 , we did not consider any of our debt securities to be other-than-temporarily impaired (2) Foreign debt securities represent public sector entity, bank or corporate debt. Securities Available-for-Sale The following provides additional information about our portfolio of securities available-for-sale: Allowance for credit losses On a quarterly basis, we perform an assessment to determine whether there have been any events or economic circumstances to indicate that a debt security available-for-sale in an unrealized loss position has suffered impairment due to credit factors. A debt security available-for-sale is considered impaired if its fair value is less than its amortized cost basis at the reporting date. If impaired, we assess whether the impairment is due to credit factors. If we intend to sell the debt security or if it is more-likely-than-not that we will be required to sell the debt security before the recovery of its amortized cost basis, the impairment is recognized and the unrealized loss is recorded as a direct write-down of the security's amortized cost basis with an offsetting entry to earnings. If we do not intend to sell the debt security or believe we will not be required to sell the debt security before the recovery of its amortized cost basis, the impairment is assessed to determine if a credit loss component exists. We use a discounted cash flow method to determine the credit loss component. In the event a credit loss exists, an allowance for credit losses is recorded in earnings for the credit loss component of the impairment while the remaining portion of the impairment attributable to factors other than credit loss is recognized, net of tax, in other comprehensive income. The amount of impairment recognized due to credit factors is limited to the excess of the amortized cost basis over the fair value of the security available-for-sale. In determining whether a credit loss component exists, we consider a series of factors which include: • The extent to which the fair value is less than the amortized cost basis; • The credit protection features embedded within the instrument, which includes but is not limited to credit subordination positions, payment structure, over collateralization, protective triggers and financial guarantees provided by third parties; • Changes in the near term prospects of the issuer or the underlying collateral of a security such as changes in default rates, loss severities given default and significant changes in prepayment assumptions; • The level of excess cash flows generated from the underlying collateral supporting the principal and interest payments of the debt securities; and • Any adverse change to the credit conditions of the issuer, the monoline insurer or the security such as credit downgrades by external rating agencies or changes to internal ratings. At March 31, 2020 and January 1, 2020, the allowance for credit losses on securities available-for-sale was $2 million and $3 million , respectively. Securities in an unrealized loss position for which no allowance for credit losses has been recognized The following table summarizes gross unrealized losses and related fair values for securities available-for-sale by major security type at March 31, 2020 classified as to the length of time the losses have existed: One Year or Less Greater Than One Year March 31, 2020 Number of Securities Gross Unrealized Losses Aggregate Fair Value of Investment Number of Securities Gross Unrealized Losses Aggregate Fair Value of Investment (dollars are in millions) Securities available-for-sale: U.S. Treasury 23 $ (86 ) $ 3,827 16 $ (123 ) $ 1,640 U.S. Government sponsored enterprises 10 (15 ) 910 10 (1 ) 95 U.S. Government agency issued or guaranteed 5 (12 ) 375 7 (2 ) 251 Asset-backed securities 1 (3 ) 59 4 (2 ) 28 Foreign debt securities 24 (7 ) 2,427 5 — 241 Securities available-for-sale 63 $ (123 ) $ 7,598 42 $ (128 ) $ 2,255 Gross unrealized losses improved as compared with December 31, 2019 due primarily to decreasing yields on U.S. Treasury and U.S. Government agency mortgage-backed securities. Although the fair value of a particular security may be below its amortized cost, it does not necessarily result in a credit loss and hence an allowance for credit losses. The decline in fair value may be caused by, among other things, the illiquidity of the market. We have reviewed the securities in an unrealized loss position for which no allowance for credit losses has been recognized in accordance with our accounting policies, discussed further above. At March 31, 2020 , we do not consider any of these securities to be impaired due to credit factors as we expect to recover their amortized cost basis and we neither intend nor expect to be required to sell these securities prior to recovery, even if that equates to holding them until their individual maturities. However, impairments due to credit factors may occur in future periods if the credit quality of the securities deteriorates. For the comparative period prior to the adoption of the new accounting guidance on January 1, 2020, we have retained the following disclosure as previously reported, which included both securities available-for-sale and securities held-to-maturity. The following table summarizes gross unrealized losses and related fair values at December 31, 2019 classified as to the length of time the losses have existed: One Year or Less Greater Than One Year December 31, 2019 Number of Securities Gross Unrealized Losses Aggregate Fair Value of Investment Number of Securities Gross Unrealized Losses Aggregate Fair Value of Investment (dollars are in millions) Securities available-for-sale: U.S. Treasury 22 $ (61 ) $ 4,034 28 $ (208 ) $ 4,962 U.S. Government sponsored enterprises 18 (8 ) 772 83 (6 ) 672 U.S. Government agency issued or guaranteed 27 (4 ) 1,961 50 (41 ) 2,508 Asset-backed securities — — — 5 (2 ) 33 Foreign debt securities 11 — 1,238 5 — 292 Securities available-for-sale 78 $ (73 ) $ 8,005 171 $ (257 ) $ 8,467 Securities held-to-maturity: U.S. Government sponsored enterprises 15 $ — $ 63 76 $ (5 ) $ 522 U.S. Government agency issued or guaranteed 46 (3 ) 887 274 (19 ) 1,705 Obligations of U.S. states and political subdivisions 1 — — 1 — — Securities held-to-maturity 62 $ (3 ) $ 950 351 $ (24 ) $ 2,227 Securities Held-to-Maturity The following provides additional information about our portfolio of securities held-to-maturity: Allowance for credit losses As discussed further in Note 6, "Allowance for Credit Losses," beginning January 1, 2020, we exclude from our calculation of lifetime expected credit losses ("lifetime ECL") securities for which we expect that non-payment of the amortized cost basis will be zero ("Zero Expected Credit Loss Exception"). Due to the composition of our portfolio of securities held-to-maturity, substantially all of our portfolio qualifies for the Zero Expected Credit Loss Exception and has been excluded from our lifetime ECL calculation. Our methodology for calculating lifetime ECL for our securities held-to-maturity which do not qualify for the Zero Expected Credit Loss Exception is consistent with our methodology for calculating lifetime ECL for loans. See Note 6, "Allowance for Credit Losses," for further discussion of this calculation including the use of probability-weighted scenarios, forward economic guidance and key model inputs. We calculate lifetime ECL for securities held-for-maturity based on the present value of expected future cash flows, discounted using the contractual interest rate which approximates the effective interest rate. At both March 31, 2020 and January 1, 2020, the allowance for credit losses on securities held-to-maturity was $2 million . At March 31, 2020 , none of our securities held-to-maturity were past due or in nonaccrual status. Credit risk profile Securities are assigned a credit rating based on the estimated probability of default. The credit ratings are used as a credit quality indicator to monitor our securities held-to-maturity portfolio. We utilize Standard and Poor's ("S&P") as the primary source of our credit ratings. If S&P ratings are not available, ratings by Moody's and Fitch are used in that order. Investment grade includes securities with credit ratings of at least BBB- or above. The following table shows the credit risk profile of our securities held-to-maturity portfolio: At March 31, 2020 Investment Grade Non-Investment Grade Total (in millions) U.S. Government sponsored enterprises $ 2,850 $ — $ 2,850 U.S. Government agency issued or guaranteed 10,121 — 10,121 Obligations of U.S. states and political subdivisions 10 — 10 Asset-backed securities collateralized by residential mortgages 2 — 2 Total securities held-to-maturity $ 12,983 $ — $ 12,983 Other securities gains, net The following table summarizes realized gains and losses on investment securities transactions attributable to available-for-sale securities: Three Months Ended March 31, 2020 2019 (in millions) Gross realized gains $ 51 $ 16 Gross realized losses (23 ) (9 ) Net realized gains $ 28 $ 7 Contractual Maturities and Yields The following table summarizes the amortized cost and fair values of securities available-for-sale and securities held-to-maturity at March 31, 2020 by contractual maturity. Expected maturities differ from contractual maturities because borrowers have the right to prepay obligations without prepayment penalties in certain cases. The table below also reflects the distribution of maturities of debt securities held at March 31, 2020 , together with the approximate yield of the portfolio. The yields shown are calculated by dividing annualized interest income, including the accretion of discounts and the amortization of premiums, by the amortized cost of securities outstanding at March 31, 2020 . Within One Year After One But Within Five Years After Five But Within Ten Years After Ten Years Amount Yield Amount Yield Amount Yield Amount Yield (dollars are in millions) Available-for-sale: U.S. Treasury $ 55 2.93 % $ 5,308 1.27 % $ 6,201 1.61 % $ 5,329 2.10 % U.S. Government sponsored enterprises 730 2.82 516 1.90 2,426 2.66 3,136 2.55 U.S. Government agency issued or guaranteed — — 80 2.12 1 7.88 11,705 2.03 Asset-backed securities — — — — 62 4.85 86 3.19 Foreign debt securities 2,242 .56 1,990 1.52 — — — — Total amortized cost $ 3,027 1.15 % $ 7,894 1.39 % $ 8,690 1.93 % $ 20,256 2.14 % Total fair value $ 3,031 $ 7,997 $ 9,176 $ 20,588 Held-to-maturity: U.S. Government sponsored enterprises $ — — % $ 480 2.66 % $ 568 2.26 % $ 1,802 3.19 % U.S. Government agency issued or guaranteed — — 12 3.92 20 4.18 10,089 2.57 Obligations of U.S. states and political subdivisions — — 6 3.58 4 4.16 — — Asset-backed securities — — — — — — 2 6.02 Total amortized cost $ — — % $ 498 2.70 % $ 592 2.34 % $ 11,893 2.67 % Total fair value $ — $ 512 $ 607 $ 12,327 Equity Securities Equity securities that are not classified as trading and are included in other assets consisted of the following: March 31, 2020 December 31, 2019 (in millions) Equity securities carried at fair value $ 278 $ 283 Equity securities without readily determinable fair values 12 12 On a quarterly basis, we perform an assessment to determine whether any equity securities without readily determinable fair values are impaired. In the event an equity security is deemed impaired, the security is written down to fair value with impairment recorded in earnings. At March 31, 2020 and December 31, 2019 , none of our equity securities without readily determinable fair values were determined to be impaired. Also included in other assets were investments in Federal Home Loan Bank ("FHLB") stock and Federal Reserve Bank stock of $324 million and $559 million , respectively, at March 31, 2020 and $110 million and $559 million , respectively, at December 31, 2019 .

Loans

Loans	3 Months Ended
	Mar. 31, 2020
Receivables [Abstract]
Loans	Loans Loans consisted of the following: March 31, 2020 December 31, 2019 (in millions) Commercial loans: Real estate, including construction $ 11,369 $ 11,501 Business and corporate banking 19,620 13,479 Global banking (1) 24,141 17,915 Other commercial: Affiliates (2) 3,087 2,343 Other 3,029 2,973 Total other commercial 6,116 5,316 Total commercial 61,246 48,211 Consumer loans: Residential mortgages 18,034 17,801 Home equity mortgages 814 853 Credit cards 1,300 1,405 Other consumer (3) 334 283 Total consumer 20,482 20,342 Total loans $ 81,728 $ 68,553 (1) Represents large multinational firms including globally focused U.S. corporate and financial institutions, U.S. dollar lending to multinational banking clients managed by HSBC on a global basis and complex large business clients supported by Global Banking and Markets relationship managers. (2) See Note 14, "Related Party Transactions," for additional information regarding loans to HSBC affiliates. (3) Includes certain student loans that we have elected to designate under the fair value option and are therefore carried at fair value, which totaled $37 million at March 31, 2020 . See Note 10, "Fair Value Option," for further details. Net deferred origination costs totaled $76 million and $79 million at March 31, 2020 and December 31, 2019 , respectively. At March 31, 2020 and December 31, 2019 , we had a net unamortized premium on our loans of $9 million and $3 million , respectively. Aging Analysis of Past Due Loans The following table summarizes the past due status of our loans at March 31, 2020 and December 31, 2019 . The aging of past due amounts is determined based on the contractual delinquency status of payments under the loan. An account is generally considered to be contractually delinquent when payments have not been made in accordance with the loan terms. Delinquency status is affected by customer account management policies and practices such as re-age, which results in the re-setting of the contractual delinquency status to current. Past Due Total Past Due 30 Days or More At March 31, 2020 30 - 89 Days 90+ Days Current (1) Total Loans (in millions) Commercial loans: Real estate, including construction $ 4 $ 2 $ 6 $ 11,363 $ 11,369 Business and corporate banking 104 8 112 19,508 19,620 Global banking — — — 24,141 24,141 Other commercial 32 — 32 6,084 6,116 Total commercial 140 10 150 61,096 61,246 Consumer loans: Residential mortgages 366 259 625 17,409 18,034 Home equity mortgages 10 23 33 781 814 Credit cards 25 28 53 1,247 1,300 Other consumer 7 5 12 322 334 Total consumer 408 315 723 19,759 20,482 Total loans $ 548 $ 325 $ 873 $ 80,855 $ 81,728 Past Due Total Past Due 30 Days or More At December 31, 2019 30 - 89 Days 90+ Days Current (1) Total Loans (in millions) Commercial loans: Real estate, including construction $ 7 $ 1 $ 8 $ 11,493 $ 11,501 Business and corporate banking 60 35 95 13,384 13,479 Global banking — — — 17,915 17,915 Other commercial 22 — 22 5,294 5,316 Total commercial 89 36 125 48,086 48,211 Consumer loans: Residential mortgages 342 272 614 17,187 17,801 Home equity mortgages 10 24 34 819 853 Credit cards 24 24 48 1,357 1,405 Other consumer 5 5 10 273 283 Total consumer 381 325 706 19,636 20,342 Total loans $ 470 $ 361 $ 831 $ 67,722 $ 68,553 (1) Loans less than 30 days past due are presented as current. Nonperforming Loans Nonperforming loans, including nonaccrual loans and accruing loans contractually 90 days or more past due, consisted of the following: Nonaccrual Loans Accruing Loans Contractually Past Due 90 Days or More Nonaccrual Loans With No Allowance For Credit Losses (in millions) At March 31, 2020 Commercial: Real estate, including construction $ 5 $ — $ 3 Business and corporate banking 112 2 2 Global banking 138 — 127 Total commercial 255 2 132 Consumer: Residential mortgages (1)(2)(3) 370 — 171 Home equity mortgages (1)(2) 38 — 31 Credit cards — 28 — Other consumer — 2 — Total consumer 408 30 202 Total nonperforming loans $ 663 $ 32 $ 334 At December 31, 2019 Commercial: Real estate, including construction $ 6 $ — $ 3 Business and corporate banking 82 1 19 Global banking 149 — 117 Total commercial 237 1 139 Consumer: Residential mortgages (1)(2)(3) 381 — 257 Home equity mortgages (1)(2) 46 — 32 Credit cards — 24 — Other consumer — 5 — Total consumer 427 29 289 Total nonperforming loans $ 664 $ 30 $ 428 (1) At March 31, 2020 and December 31, 2019 , nonaccrual consumer mortgage loans include $286 million and $289 million , respectively, of loans that are carried at the lower of amortized cost or fair value of the collateral less cost to sell. The decrease in nonaccrual consumer mortgage loans with no allowance for credit losses at March 31, 2020 reflects the impact of adopting new accounting guidance which requires expected recoveries related to subsequent increases in the fair value of collateral for collateral-dependent loans to be recognized in the allowance for credit losses beginning January 1, 2020. See Note 21, "New Accounting Pronouncements," for additional discussion. (2) Nonaccrual consumer mortgage loans include all loans which are 90 or more days contractually delinquent as well as loans discharged under Chapter 7 bankruptcy and not re-affirmed and second lien loans where the first lien loan that we own or service is 90 or more days contractually delinquent. (3) Nonaccrual consumer mortgage loans for all periods does not include guaranteed loans purchased from the Government National Mortgage Association. Repayment of these loans is predominantly insured by the Federal Housing Administration and as such, these loans have different risk characteristics from the rest of our consumer loan portfolio. The following table provides additional information on our nonaccrual loans: Three Months Ended March 31, 2020 2019 (in millions) Interest income that would have been recorded if the nonaccrual loans had been current in accordance with contractual terms during the period $ 8 $ 9 Interest income that was recorded on nonaccrual loans and included in interest income during the period 7 3 Collateral-Dependent Loans Loans for which the repayment is expected to be provided substantially through the operation or sale of the collateral and the borrower is experiencing financial difficulty are considered to be collateral-dependent loans. Collateral can have a significant financial effect in mitigating our exposure to credit risk and, where there is sufficient collateral, an allowance for expected credit losses is not recognized or is minimal. Collateral-dependent residential mortgage loans are carried at the lower of amortized cost or fair value of the collateral less costs to sell, with any excess in the carrying amount of the loan generally charged off at the time foreclosure is initiated or when settlement is reached with the borrower, but not to exceed the end of the month in which the account becomes six months contractually delinquent. Collateral values are based on broker price opinions or appraisals which are updated at least every 180 days less estimated costs to sell. During the quarterly period between updates, real estate price trends are reviewed on a geographic basis and incorporated as necessary. At March 31, 2020 and December 31, 2019 , we had collateral-dependent residential mortgage loans totaling $802 million and $803 million , respectively. For collateral-dependent commercial loans, the allowance for expected credit losses is individually assessed based on the fair value of the collateral. Various types of collateral are used, including real estate, inventory, equipment, accounts receivable, securities and cash, among others. For commercial real estate loans, collateral values are generally based on appraisals which are updated based on management judgment under the specific circumstances on a case-by-case basis. In situations where an appraisal is not used, borrower-specific factors such as operating results, cash flows and debt service ratios are reviewed along with relevant market data of comparable properties in order to create a 10-year cash flow model to be discounted at appropriate rates to present value. The collateral value for securities is based on their quoted market prices or broker quotes. The collateral value for other financial assets is generally based on appraisals or is estimated using a discounted cash flow analysis. Commercial loan balances are charged off at the time all or a portion of the balance is deemed uncollectible. At March 31, 2020 and December 31, 2019 , we had collateral-dependent commercial loans totaling $252 million and $227 million , respectively. Troubled debt restructurings TDR Loans, including beginning in 2020 loans which we reasonably expect to become TDR Loans ("anticipatory TDRs"), represent loans for which the original contractual terms have been modified to provide for terms that are less than what we would be willing to accept for new loans with comparable risk because of deterioration in the borrower's financial condition. There were no anticipatory TDRs at March 31, 2020. Modifications for consumer or commercial loans may include changes to one or more terms of the loan, including, but not limited to, a change in interest rate, extension of the amortization period, reduction in payment amount and partial forgiveness or deferment of principal, accrued interest or other loan covenants. A substantial amount of our modifications involve interest rate reductions on consumer loans, which lower the amount of interest income we are contractually entitled to receive in future periods. Through lowering the interest rate and other loan term changes, we believe we are able to increase the amount of cash flow that will ultimately be collected from the loan, given the borrower's financial condition. Once a consumer loan is classified as a TDR Loan, it continues to be reported as such until it is paid off or charged-off. For commercial loans, if subsequent performance is in accordance with the new terms and the loan is upgraded, it is possible the loan will no longer be reported as a TDR Loan at the earliest one year after the restructure had been anticipated. During the three months ended March 31, 2020 and 2019 there were no commercial loans that met this criteria and were removed from TDR Loan classification. The following table summarizes our TDR Loans at March 31, 2020 and December 31, 2019 : March 31, 2020 December 31, 2019 (in millions) Commercial loans: Business and corporate banking $ 32 $ 36 Global banking 69 68 Total commercial (1) 101 104 Consumer loans: Residential mortgages (2) 561 580 Home equity mortgages (2) 32 32 Credit cards 4 4 Total consumer 597 616 Total TDR Loans (3) $ 698 $ 720 (1) Additional commitments to lend to commercial borrowers whose loans have been modified in TDR Loans totaled $143 million and $222 million at March 31, 2020 and December 31, 2019 , respectively. (2) At March 31, 2020 and December 31, 2019 , the carrying value of consumer mortgage TDR Loans includes $508 million and $557 million , respectively, of loans that are recorded at the lower of amortized cost or fair value of the collateral less cost to sell. (3) At March 31, 2020 and December 31, 2019 , the carrying value of TDR Loans includes $318 million and $230 million , respectively, of loans which are classified as nonaccrual. The following table presents information about loans which were modified during the three months ended March 31, 2020 and 2019 and as a result of this action became classified as TDR Loans: Three Months Ended March 31, 2020 2019 (in millions) Commercial loans: Global banking $ 12 $ — Total commercial 12 — Consumer loans: Residential mortgages 4 1 Home equity mortgages 1 — Credit cards 1 1 Total consumer 6 2 Total $ 18 $ 2 The weighted-average contractual rate reduction for consumer loans which became classified as TDR Loans during the three months ended March 31, 2020 and 2019 was 3.04 percent and 1.24 percent , respectively. The weighted-average contractual rate reduction for commercial loans was not significant in either the number of loans or rate. The following table presents consumer loans which were classified as TDR Loans during the previous 12 months which subsequently became 60 days or greater contractually delinquent during the three months ended March 31, 2020 and 2019 : Three Months Ended March 31, 2020 2019 (in millions) Consumer loans: Residential mortgages $ 1 $ 2 Total consumer $ 1 $ 2 During the three months ended March 31, 2020 and 2019 , there were no commercial TDR Loans which were classified as TDR Loans during the previous 12 months which subsequently became 90 days or greater contractually delinquent. Commercial Loan Credit Quality Indicators The following credit quality indicators are utilized to monitor our commercial loan portfolio: Criticized loans Criticized loan classifications presented in the table below are determined by the assignment of various criticized facility grades based on the risk rating standards of our regulator. The following facility grades are deemed to be criticized: Special Mention - generally includes loans that are protected by collateral and/or the credit worthiness of the customer, but are potentially weak based upon economic or market circumstances which, if not checked or corrected, could weaken our credit position at some future date. Substandard - includes loans that are inadequately protected by the underlying collateral and/or general credit worthiness of the customer. These loans present a distinct possibility that we will sustain some loss if the deficiencies are not corrected. Doubtful - includes loans that have all the weaknesses exhibited by substandard loans, with the added characteristic that the weaknesses make collection or liquidation in full of the recorded loan highly improbable. However, although the possibility of loss is extremely high, certain factors exist which may strengthen the credit at some future date, and therefore the decision to charge-off the loan is deferred. Loans graded as doubtful are required to be placed in nonaccrual status. The following table summarizes our criticized commercial loans, including a disaggregation of the loans by year of origination as of March 31, 2020 : 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total at Mar. 31, 2020 Total at Dec. 31, 2019 (in millions) Real estate, including construction: Special mention $ — $ 402 $ 150 $ 122 $ — $ 234 $ — $ — $ 908 $ 516 Substandard — 130 7 — — 45 — — 182 203 Doubtful — — — — — — — — — — Total real estate, including construction — 532 157 122 — 279 — — 1,090 719 Business and corporate banking: Special mention — 25 21 50 13 164 555 24 852 467 Substandard — 29 24 24 2 121 367 2 569 386 Doubtful — 16 13 — — 18 64 2 113 23 Total business and corporate banking — 70 58 74 15 303 986 28 1,534 876 Global banking: Special mention — 38 — — — 102 334 — 474 184 Substandard — — — — — 86 270 — 356 196 Doubtful — — — — — 13 — — 13 15 Total global banking — 38 — — — 201 604 — 843 395 Other commercial: Special mention — 24 11 — 3 20 — — 58 11 Substandard — — — — — — 61 — 61 — Doubtful — — — — — — — — — — Total other commercial — 24 11 — 3 20 61 — 119 11 Total commercial: Special mention — 489 182 172 16 520 889 24 2,292 1,178 Substandard — 159 31 24 2 252 698 2 1,168 785 Doubtful — 16 13 — — 31 64 2 126 38 Total commercial $ — $ 664 $ 226 $ 196 $ 18 $ 803 $ 1,651 $ 28 $ 3,586 $ 2,001 Nonperforming The following table summarizes the nonperforming status of our commercial loan portfolio, including a disaggregation of the loans by year of origination as of March 31, 2020 : 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total at Mar. 31, 2020 Total at Dec. 31, 2019 (in millions) Real estate, including construction: Performing loans $ 405 $ 3,800 $ 3,095 $ 1,389 $ 335 $ 2,169 $ 147 $ 24 $ 11,364 $ 11,495 Nonaccrual loans — — — 1 2 — 2 5 6 Accruing loans contractually past due 90 days or more — — — — — — — — — — Total real estate, including construction 405 3,800 3,095 1,389 336 2,171 147 26 11,369 11,501 Business and corporate banking: Performing loans 619 1,509 840 415 540 3,428 11,808 347 19,506 13,396 Nonaccrual loans — 16 13 — — 16 66 1 112 82 Accruing loans contractually past — — — — — — 2 — 2 1 Total business and corporate banking 619 1,525 853 415 540 3,444 11,876 348 19,620 13,479 Global banking: Performing loans 378 1,832 1,501 842 564 4,386 14,500 — 24,003 17,766 Nonaccrual loans — — — — 19 51 68 — 138 149 Accruing loans contractually past due 90 days or more — — — — — — — — — — Total global banking 378 1,832 1,501 842 583 4,437 14,568 — 24,141 17,915 Other commercial: Performing loans 137 477 335 185 148 384 4,450 — 6,116 5,316 Nonaccrual loans — — — — — — — — — — Accruing loans contractually past due 90 days or more — — — — — — — — — — Total other commercial 137 477 335 185 148 384 4,450 — 6,116 5,316 Total commercial: Performing loans 1,539 7,618 5,771 2,831 1,587 10,367 30,905 371 60,989 47,973 Nonaccrual loans — 16 13 — 20 69 134 3 255 237 Accruing loans contractually past due 90 days or more — — — — — — 2 — 2 1 Total commercial $ 1,539 $ 7,634 $ 5,784 $ 2,831 $ 1,607 $ 10,436 $ 31,041 $ 374 $ 61,246 $ 48,211 Credit risk profile Commercial loans are assigned a credit rating based on the estimated probability of default. Investment grade includes loans with credit ratings of at least BBB- or above or the equivalent based on our internal credit rating system. The following table shows the credit risk profile of our commercial loan portfolio, including a disaggregation of the loans by year of origination as of March 31, 2020 : 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total at Mar. 31, 2020 Total at Dec. 31, 2019 (in millions) Real estate, including construction: Investment grade $ 287 $ 1,392 $ 1,500 $ 515 $ 202 $ 1,205 $ 6 $ 4 $ 5,111 $ 6,332 Non-investment grade 118 2,408 1,595 874 134 966 141 22 6,258 5,169 Total real estate, including construction 405 3,800 3,095 1,389 336 2,171 147 26 11,369 11,501 Business and corporate banking: Investment grade 459 611 202 104 389 1,744 5,219 87 8,815 6,029 Non-investment grade 160 914 651 311 151 1,700 6,657 261 10,805 7,450 Total business and corporate banking 619 1,525 853 415 540 3,444 11,876 348 19,620 13,479 Global banking: Investment grade 319 1,363 1,013 802 141 3,299 10,386 — 17,323 12,981 Non-investment grade 59 469 488 40 442 1,138 4,182 — 6,818 4,934 Total global banking 378 1,832 1,501 842 583 4,437 14,568 — 24,141 17,915 Other commercial: Investment grade 76 431 247 163 96 300 4,217 — 5,530 4,649 Non-investment grade 61 46 88 22 52 84 233 — 586 667 Total other commercial 137 477 335 185 148 384 4,450 — 6,116 5,316 Total commercial: Investment grade 1,141 3,797 2,962 1,584 828 6,548 19,828 91 36,779 29,991 Non-investment grade 398 3,837 2,822 1,247 779 3,888 11,213 283 24,467 18,220 Total commercial $ 1,539 $ 7,634 $ 5,784 $ 2,831 $ 1,607 $ 10,436 $ 31,041 $ 374 $ 61,246 $ 48,211 Consumer Loan Credit Quality Indicators The following credit quality indicators are utilized to monitor our consumer loan portfolio: Delinquency The following table summarizes dollars of two-months-and-over contractual delinquency for our consumer loan portfolio, including a disaggregation of the loans by year of origination as of March 31, 2020 : 2020 2019 2018 2017 2016 Prior Revolving Loans Total at Mar. 31, 2020 Total at Dec. 31, 2019 (in millions) Residential mortgages (1)(2) $ — $ 11 $ 10 $ 15 $ 13 $ 315 $ — $ 364 $ 350 Home equity mortgages (1)(2) — — — — — 26 — 26 25 Credit cards — — — — — — 39 39 34 Other consumer — 1 — — — 4 2 7 7 Total consumer $ — $ 12 $ 10 $ 15 $ 13 $ 345 $ 41 $ 436 $ 416 (1) At March 31, 2020 and December 31, 2019 , consumer mortgage loan delinquency includes $249 million and $256 million , respectively, of loans that are carried at the lower of amortized cost or fair value of the collateral less cost to sell. (2) At March 31, 2020 and December 31, 2019 , consumer mortgage loans include $135 million and $142 million , respectively, of loans that were in the process of foreclosure. Nonperforming The following table summarizes the nonperforming status of our consumer loan portfolio, including a disaggregation of the loans by year of origination as of March 31, 2020 : 2020 2019 2018 2017 2016 Prior Revolving Loans Total at Mar. 31, 2020 Total at Dec. 31, 2019 (in millions) Residential mortgages: Performing loans $ 1,032 $ 2,968 $ 1,799 $ 2,049 $ 2,359 $ 7,457 $ — $ 17,664 $ 17,420 Nonaccrual loans — 8 6 13 12 331 — 370 381 Total residential mortgages 1,032 2,976 1,805 2,062 2,371 7,788 — 18,034 17,801 Home equity mortgages: Performing loans 14 54 44 41 53 570 — 776 807 Nonaccrual loans — — — — — 38 — 38 46 Total home equity mortgages 14 54 44 41 53 608 — 814 853 Credit cards: Performing loans — — — — — — 1,272 1,272 1,381 Accruing loans contractually past due 90 days or more — — — — — — 28 28 24 Total credit cards — — — — — — 1,300 1,300 1,405 Other consumer: Performing loans 41 63 1 2 4 125 96 332 278 Accruing loans contractually past due 90 days or more — — — — — — 2 2 5 Total other consumer 41 63 1 2 4 125 98 334 283 Total consumer: Performing loans 1,087 3,085 1,844 2,092 2,416 8,152 1,368 20,044 19,886 Nonaccrual loans — 8 6 13 12 369 — 408 427 Accruing loans contractually past due 90 days or more — — — — — — 30 30 29 Total consumer $ 1,087 $ 3,093 $ 1,850 $ 2,105 $ 2,428 $ 8,521 $ 1,398 $ 20,482 $ 20,342 Troubled debt restructurings The following table summarizes TDR Loans in our consumer loan portfolio, including a disaggregation of the loans by year of origination as of March 31, 2020 : 2020 2019 2018 2017 2016 Prior Revolving Loans Total at Mar. 31, 2020 Total at Dec. 31, 2019 (in millions) Residential mortgages $ — $ — $ — $ — $ 1 $ 560 $ — $ 561 $ 580 Home equity mortgages — — — — — 32 — 32 32 Credit cards — — — — — — 4 4 4 Total consumer $ — $ — $ — $ — $ 1 $ 592 $ 4 $ 597 $ 616 Concentration of Credit Risk At March 31, 2020 and December 31, 2019 , our loan portfolios included interest-only residential mortgage and home equity mortgage loans totaling $3,366 million and $3,362 million , respectively. An interest-only residential mortgage loan allows a customer to pay the interest-only portion of the monthly payment for a period of time which results in lower payments during the initial loan period. However, subsequent events affecting a customer's financial position could affect the ability of customers to repay the loan in the future when the principal payments are required which increases the credit risk of this loan type.

Allowance for Credit Losses

Allowance for Credit Losses	3 Months Ended
	Mar. 31, 2020
Credit Loss [Abstract]
Allowance for Credit Losses	Allowance for Credit Losses As discussed further in Note 21, "New Accounting Pronouncements," beginning January 1, 2020, an allowance for credit losses is recognized based on lifetime ECL for loans, securities held-to-maturity and certain other financial assets measured at amortized cost, and an allowance for credit losses is also recognized for securities available-for-sale. Prior to January 1, 2020, an allowance for credit losses was recognized based on probable incurred losses for loans only while debt securities were assessed for other-than-temporary impairment. In addition, beginning January 1, 2020, the liability for off-balance sheet credit exposures is recognized based on lifetime ECL while, prior to January 1, 2020, it was recognized based on probable incurred losses. The new guidance also requires inclusion of expected recoveries of amounts previously written off, limited to the cumulative amount of prior write-offs, when estimating the allowance for credit losses for in scope financial assets (including collateral-dependent assets). Prior to January 1, 2020, these expected recoveries were not recognized. Comparative information at January 1, 2020, reflecting the adoption of the new accounting guidance has been included in the tables below where applicable. Comparative information at December 31, 2019, which is not comparable as it does not reflect the adoption of the new accounting guidance, has been retained as previously reported. Measurement of ECL Estimates The recognition and measurement of lifetime ECL is highly complex and involves the use of significant judgment and estimation. Multiple forward-looking economic forecasts are formulated and incorporated into the lifetime ECL calculations when estimating the allowance for credit losses for in scope financial assets and the liability for off-balance sheet credit exposures as discussed below under the heading "Calculation of Lifetime ECL". We utilize a standard framework to form economic scenarios to reflect assumptions about future economic conditions supplemented by the use of management judgment, which may result in using alternative or additional economic scenarios and/or management adjustments. Methodology HUSI has adopted the use of three forward-looking economic scenarios, representative of management's view of forecasted economic conditions, sufficient to calculate unbiased expected loss in most economic environments. They represent a 'most likely outcome' (the "Central scenario") and two less likely 'outer' scenarios, referred to as the "Upside scenario" and the "Downside scenario". Each scenario is assigned a weighting with the significant majority of the weighting placed on the Central scenario and lower equal weights placed on the Upside and Downside scenarios. This weighting is deemed appropriate for the estimation of lifetime ECL, unless determined otherwise. See Updates to Economic Scenarios and Other Changes During the Three Months Ended March 31, 2020 below for further discussion. Key Central scenario assumptions are set using the average of forecasts of external economists, helping to ensure the scenarios are unbiased and maximize the use of independent information, except when in management's judgment it is believed not to be representative of the current economic environment. The Central, Upside and Downside scenarios selected with reference to external forecast distributions using the above approach are termed the "Consensus Economic Scenarios". We have determined that two years is a reasonable and supportable forecast period for the Consensus Economic Scenarios. At the end of the two year reasonable and supportable forecast period, assumption variables start to revert to their 20 -year average of historical values over a reversion period. The reversion period for most assumption variables is generally three years , but is longer in some specific cases. The reversion path for this period is linear in the Central scenario for all variables. The reversion path for variables in the Upside and Downside scenarios is generally non-linear. For the Central scenario, we set key assumptions such as Gross Domestic Product ("GDP") growth, inflation, unemployment, housing price growth, U.S. Treasury yields, equity price growth, short-term interest rates and oil price using either the average of external forecasts (commonly referred to as consensus forecasts) or market implied rates. An external provider's model, conditioned to follow the consensus forecasts for the above key assumption variables, projects the remaining variable paths required as inputs to credit models. This external provider is subject to our risk governance framework, including oversight by an internal independent model review team. The Upside and Downside scenarios are constructed following a standard process supported by a scenario narrative reflecting our top and emerging risks and by consulting external and internal subject matter experts. They are designed to be cyclical in that GDP growth, inflation and unemployment usually revert back to the Central scenario after the first two years. We determine the maximum divergence of GDP growth from the Central scenario using the 10th and the 90th percentile of the entire distribution of consensus forecast outcomes. Using externally available forecast distributions ensures independence in scenario construction. Key economic variables are set with reference to external distributional forecasts and we project additional variable paths using the external provider's model. Generally, the Upside and Downside scenarios are generated at year-end and are only updated during the year if economic conditions change significantly. The Central scenario is generated every quarter. In quarters where only the Central scenario is updated, the Upside and Downside scenarios used for commercial loans are adjusted such that the relationship between the Central scenario and the Upper and Downside scenarios in the quarter is consistent with that observed at the last full scenario generation. For consumer loans, the three scenarios are run annually to establish the effect of multiple scenarios on the ECL estimates for each portfolio. This effect is then applied in each quarter with the understanding that the non-linearity of response to economic conditions should not change, unless a significant change in economic conditions occurs. We recognize that the Consensus Economic Scenario approach using three scenarios may be insufficient in certain economic environments. Additional analysis may be requested at management's discretion. This may result in a change to the weighting assigned to the three scenarios or the inclusion of extra scenarios. We exclude from our lifetime ECL calculation financial assets which qualify for the Zero Expected Credit Loss Exception. As a result, no allowance for credit losses is recorded for these financial assets. We have identified the following types of financial assets which we believe qualify for this exclusion: • U.S. Treasury securities; • U.S. Government agency issued or guaranteed securities; • U.S. Government sponsored enterprises securities; • G10 sovereign foreign debt securities; and • Interest bearing deposits held with the Federal Reserve Bank. We also exclude from our lifetime ECL calculation financial assets which are secured by collateral maintenance provisions (e.g., the borrower is contractually required to adjust the amount of financial collateral securing the financial asset) if such collateral meets liquidity requirements. In most circumstances subject to such requirements, collateral exceeds our amortized cost basis and no allowance for credit losses is recorded for these financial assets, consisting of the substantial majority of our securities purchased under agreements to resell as well as substantially all of our margin loans provided to our Private Banking customers. In addition, loans to other HSBC affiliated entities are exempt from ECL measurement. Description of Consensus Economic Scenarios Adopted on January 1, 2020 The following discussion summarizes the key macroeconomic variable forecasts in the Central, Upside and Downside scenarios at January 1, 2020. The economic assumptions described in this section have been formed specifically for the purpose of calculating ECL. While macroeconomic assumptions have changed significantly during the first quarter, the following scenarios are being provided to explain the impact of adopting the Consensus Economic Scenarios on January 1, 2020. The Central scenario at January 1, 2020 - In the Central scenario, growth was expected to slow down in the United States as the benefits from tax reform waned in 2020. Inflation was forecast to remain around the target of 2 percent , while the unemployment rate was expected to stay at a low level in 2020 before gradually rising towards its long-term trend. The expected paths for Federal Reserve Board ("FRB") policy rates implied three rate cuts in 2020. The Upside scenario at January 1, 2020 - In the Upside scenario, the economic forecast distribution of risks (as captured by consensus probability distribution of GDP growth) showed a marginal increase in upside risk for the United States in the reasonable and supportable period. Increased confidence, positive resolution of trade disputes and expansionary fiscal policy supported the Upside scenario. In this scenario, GDP growth rose to 4.0 percent in 2020, which drove inflation higher and unemployment to fall further than in the Central scenario. Stronger GDP growth and domestic demand supported stronger equity and housing prices in this scenario. The Downside scenario at January 1, 2020 - In the Downside scenario, the economic forecast distribution of risks (as captured by consensus probability distribution of GDP growth) showed a marginal increase in the downside risks for the United States in the reasonable and supportable period. In this scenario, the U.S. economy was expected to contract in 2020 before slowly reverting back to the long-run trend. The slowdown in growth was consistent with an escalation of trade tensions with China and other trading partners in this scenario. Additional tariffs and non-tariff barriers on trade were expected to lead to the benefits from corporate tax cuts being offset by a sharp rise in costs for businesses and consumers and a loss of confidence in this scenario, while lower business investment and confidence were expected to affect hiring, with an impact on the unemployment rate and earnings expectations. In the downside scenario, policy interest rates were expected to be cut back below 0.5 percent in order to support growth and inflation. In conjunction with adopting the new accounting guidance, we performed a review of the methodology used to estimate lifetime ECL and determined that risk associated with the non-homogeneous nature of our current commercial loan portfolio and the potential impact of large loan defaults was not fully captured in the models. As a result, we recorded a management judgment allowance of $125 million for risk factors associated with large loan exposure in our commercial loan portfolio at January 1, 2020. Updates to Economic Scenarios and Other Changes During the Three Months Ended March 31, 2020 As a result of the deterioration in economic conditions caused by the spread of the COVID-19 pandemic during the first quarter of 2020 and the related increase in economic uncertainty given the rapidly changing economic impact, we determined that the Consensus Economic Scenarios described above were no longer representative of management's current view of forecasted economic conditions and, as a result, three new COVID-19 forward-looking economic scenarios were developed and utilized for estimating lifetime ECL at March 31, 2020. The three new COVID-19 scenarios, referred to as mild, moderate and severe, were assigned weightings with the majority of the weighting placed on the mild scenario and progressively lower weights placed on the moderate and severe scenarios. This weighting was deemed appropriate for the estimation of lifetime ECL under current conditions. The following discussion summarizes the COVID-19 macroeconomic variable forecasts in the mild, moderate and severe scenarios at March 31, 2020. In the mild scenario , widespread and large-scale movement restrictions and social distancing measures are lifted by the end of 2020. In this scenario, GDP growth contracts for one quarter, before rebounding towards its historical average, while unemployment and housing prices both worsen modestly for a period of one to two years. In the financial markets, equity prices experience a correction, reflecting the COVID-19 impact on corporate earnings, and the 10-year U.S. Treasury yield falls into negative territory due to supportive monetary policy. In the moderate scenario , widespread and large-scale movement restrictions and social distancing measures are sustained, lifting by the second quarter of 2021. In this scenario, the economic downturn lasts longer than in the mild scenario. As a result, the unemployment rate increases significantly in 2020 and the first half of 2021, before gradually returning to its historical average in 2022. Weakness in the housing market lingers, with the price level not returning to the pre-pandemic level until 2027, while equity prices decline by over 20 percent by the end of 2020. In the severe scenario , widespread and large-scale movement restrictions and social distancing measures are sustained further, lifting at different paces over the course of 2021. In this scenario, GDP growth contracts substantially in 2020 and stays flat in 2021. The housing downturn lasts longer than in the moderate and mild scenarios, with the decline in housing prices exceeding 20 percent . The unemployment rate spikes to the peak level from the 2007-2009 recession, and remains elevated above the long-term average in 2022 and 2023. The decline in equity prices exceeds 40 percent by the end of 2020, while the 10-year U.S. Treasury yield falls below (1) percent beginning in the second quarter of 2020. In addition to the updates to the economic scenarios, we recorded a management judgment allowance which increased our consumer allowance for credit losses by $41 million to consider the extent of recent economic events and deteriorating conditions that were not fully captured in the economic scenarios applied at March 31, 2020. The circumstances around this pandemic are evolving rapidly and will continue to impact our business and our allowance for credit losses in future periods. The details of how various U.S. Government actions will impact our customers and therefore the impact on our allowance for credit losses remains highly uncertain. We will continue to monitor the COVID-19 situation closely and anticipate returning to utilizing our Consensus Economic Scenarios approach as described above if and when the economic environment in the United States improves and returns to more normal conditions. We also increased our management judgment allowance for risk factors associated with large loan exposure in our commercial loan portfolio by $95 million to $220 million at March 31, 2020, reflecting an increase in projected large loan defaults given the deterioration in economic conditions during the quarter. Calculation of Lifetime ECL Commercial loans Commercial loans are monitored on a continuous basis with a formal assessment completed, at a minimum, annually. As part of this process, a credit rating and loss given default ("LGD") are assigned and serve as the basis for establishing an allowance for these loans' expected balance at default ("EAD") based on a probability of default ("PD") estimate associated with each credit rating under the allowance for credit losses methodology. In assigning the credit ratings to a particular loan, among the risk factors considered are the obligor's debt capacity and financial position, the level of earnings, the amount and sources for repayment, the level of contingencies, management strength and the industry or geography in which the obligor operates. We utilize a consistent methodology for the application of forward economic guidance ("FEG") into the calculation of lifetime ECL by incorporating FEG into the estimation of the term structure of PD and LGD. For PDs, we consider the correlation of FEG to default rates for a particular industry. For LGDs, we consider the correlation of FEG to collateral values and realization rates for a particular industry and if applicable, country which is adjusted for recoveries. Our PD estimates are validated on an annual basis using back-testing of actual default rates and benchmarking of the internal ratings with external rating agency data like S&P ratings and default rates. PDs and LGDs are estimated for the entire term structure of the loan. Credit Review, a function independent of the business, provides an on-going assessment of lending activities that includes independently assessing credit ratings and LGD estimates for sampled credits across various portfolios. Loans with similar risk characteristics are pooled for determining lifetime ECL. When it is deemed probable based upon known facts and circumstances that full interest and principal on an individual loan will not be collected in accordance with its contractual terms, in general the loan is no longer considered part of the collective pool of homogeneous loans against which lifetime ECL are established. Instead, an allowance for credit losses is established on an individual basis ("individually assessed") primarily based on the present value of expected future cash flows, discounted at the loan's original effective interest rate, or the fair value of the collateral if the loan is collateral dependent. Individually assessed loans are evaluated quarterly. Generally, loans that are placed on non-accrual must be removed from a collective pool and individually assessed. In addition, the allowance for credit losses may reflect consideration of management judgment of risk factors that are considered likely to cause estimated credit losses associated with the existing portfolio to differ from historical loss experience as well as where the models used to generate the reserves do not produce an estimate that is sufficient to encompass the current view of lifetime ECL. In making this determination, we consider the characteristics of our portfolio and any other significant factors that are relevant. Factors that are relevant to determining the expected collectability of our loan portfolio include, but are not limited to, the volume and severity of past due loans, the volume and severity of adversely classified or rated loans, the underlying collateral on loans that are not collateral dependent, lending policies and procedures including changes in lending strategies, underwriting standards or collection and recovery practices as well as the obligor's operations, environmental factors of an obligor and the areas in which our credit exposure is concentrated, the non-homogeneous nature of the portfolio, changes and expected changes in the general market condition of either a geographical area or an industry, and changes in international, national, regional, and local economic and business conditions. For loans which have been identified as TDR Loans, including beginning in 2020 loans which we reasonably expect to become TDR Loans, judgment will be used as to whether or not we expect full repayment of principal and interest. If full repayment is expected, the TDR Loan will remain in a collective pool of homogeneous loans for determining lifetime ECL. When full repayment of principal and interest is not expected or, beginning in 2020, when we anticipate offering payment concessions, the loan will be removed from the pool and individually assessed. If a commercial TDR subsequently performs in accordance with the new terms and the loan is upgraded, it is possible the loan will no longer be reported as a TDR Loan at the earliest one year after the restructure had been anticipated. Consumer loans For pools of homogeneous consumer loans and certain small business loans which do not qualify as TDR Loans, we estimate lifetime ECL using a component based framework based on PD, LGD and EAD that estimates the likelihood that a loan will progress through the various stages of delinquency and ultimately charge-off based upon a forward-looking view of macro-economic expectations that impact a lifetime ECL and historical experience. The impact of FEG on PD is modeled at the loan or segment level depending on the portfolio. Historic relationships between observed default rates and macroeconomic variables are integrated into lifetime ECL estimates by leveraging economic response models. The impact of FEG on PD is modeled over a period equal to the remaining maturity of the underlying loans. The impact on LGD is modeled for mortgage portfolios by forecasting future loan-to-value ("LTV") profiles for the remaining maturity of the loans by leveraging national forecasts of the house price index ("HPI") and applying the corresponding LGD expectation. The models consider delinquency status, loss experience and severity, and take into account where borrowers have historically filed for bankruptcy or have been subject to account management actions, such as the re-age or modification of accounts. Expected loss severity is based on the underlying collateral, if any, for the loan in the event of default based on historical and recent trends which are updated monthly based on a rolling average of several months' data using the most recently available information. The lifetime ECL recognized for consumer loans considers the effect on lifetime ECL over a range of potential outcomes, calculated on a probability-weighted basis, based on the economic scenarios described above, including management judgment where required. Management judgment reflects consideration of risk factors that are considered likely to cause estimated credit losses associated with the existing portfolio to differ from historical loss experience as well as where the models used to generate the reserves do not produce an estimate that is sufficient to encompass the current view of lifetime ECL. In making this determination, we consider the characteristics of our portfolio and any other significant factors that are relevant. Factors that are relevant to determining the expected collectability of our consumer loan portfolio include, but are not limited to changes in risk selection or underwriting standards, changes in collection, account management, charge-off and recovery practices and changes in loan concentrations affecting either the frequency or severity of losses. For loans which have been identified as TDR Loans, including beginning in 2020, loans which we reasonably expect to become TDR Loans, an allowance for credit losses is maintained primarily based on the present value of expected future cash flows, discounted at the loan's original effective interest rate, or the fair value of the collateral if the loan is collateral dependent. Once a loan is classified as a TDR Loan, it continues to be reported as such until it is paid off or charged-off. Collateral-dependent loans As discussed above, beginning January 1, 2020, expected recoveries related to subsequent increases in the fair value of collateral for collateral-dependent loans that were previously written down below current recovery value estimates are recognized in the allowance for credit losses. The amount recognized is limited to the cumulative amount of prior write-offs. See Note 5, "Loans," for additional information regarding collateral-dependent loans. Off-balance sheet credit exposures A separate estimate of lifetime ECL for off-balance sheet credit exposures is also maintained, which is recorded in interest, taxes and other liabilities on the consolidated balance sheet and includes lifetime ECL arising from off-balance sheet exposures such as letters of credit, guarantees and unused commitments to extend credit. The process for measuring lifetime ECL on these exposures is consistent with that for commercial or consumer loans discussed above as applicable, but is subject to an additional parameter reflecting the likelihood that funding will occur. No lifetime ECL is recognized for off-balance sheet credit exposures that are unconditionally cancellable by us such as unused credit card lines of credit. Securities See Note 4, "Securities," for discussion of the methodologies utilized for calculating the allowance for credit losses on our securities available-for-sale and securities held-to-maturity portfolios. The following table summarizes our allowance for credit losses and the liability for off-balance sheet credit exposures: March 31, 2020 January 1, 2020 December 31, 2019 (in millions) Allowance for credit losses: Loans $ 931 $ 467 $ 637 Securities held-to-maturity (1) 2 2 — Other financial assets measured at amortized cost (2) 5 3 — Securities available-for-sale (1) 2 3 — Total allowance for credit losses $ 940 $ 475 $ 637 Liability for off-balance sheet credit exposures $ 371 $ 158 $ 104 (1) See Note 4, "Securities," for additional information regarding the allowance for credit losses associated with our security portfolios. (2) Primarily includes accrued interest receivables and customer acceptances. The following table summarizes the changes in the allowance for credit losses on loans by product or line of business during the three months ended March 31, 2020 and 2019 : Commercial Loans Consumer Loans Real Estate, including Construction Business Global Other Residential Home Credit Other Total Loans (in millions) Three Months Ended March 31, 2020 Allowance for credit losses – beginning of period $ 153 $ 239 $ 106 $ 9 $ 12 $ 6 $ 105 $ 7 $ 637 Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses (112 ) (60 ) 51 (5 ) (86 ) 7 32 3 (170 ) Allowance for credit losses – beginning of period, adjusted 41 179 157 4 (74 ) 13 137 10 467 Provision charged (credited) to income 51 213 110 1 30 3 95 9 512 Charge-offs — (12 ) (19 ) — 1 (2 ) (22 ) (2 ) (56 ) Recoveries — 2 — — 2 2 2 — 8 Net (charge-offs) recoveries — (10 ) (19 ) — 3 — (20 ) (2 ) (48 ) Allowance for credit losses – end of period $ 92 $ 382 $ 248 $ 5 $ (41 ) $ 16 $ 212 $ 17 $ 931 Three Months Ended March 31, 2019 Allowance for credit losses – beginning of period $ 116 $ 219 $ 108 $ 15 $ 13 $ 7 $ 58 $ 5 $ 541 Provision charged (credited) to income 3 22 14 — (1 ) 1 16 3 58 Charge-offs — (2 ) — — (4 ) (1 ) (13 ) (1 ) (21 ) Recoveries — — — — 2 1 2 — 5 Net (charge-offs) recoveries — (2 ) — — (2 ) — (11 ) (1 ) (16 ) Allowance for credit losses – end of period $ 119 $ 239 $ 122 $ 15 $ 10 $ 8 $ 63 $ 7 $ 583 The following table summarizes the changes in the liability for off-balance sheet credit exposures during the three months ended March 31, 2020 and 2019 : Three Months Ended March 31, 2020 2019 (in millions) Balance at beginning of period $ 104 $ 96 Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses 54 — Balance at beginning of period, adjusted 158 96 Provision charged (credited) to income 213 (7 ) Balance at end of period $ 371 $ 89 Accrued Interest Receivables The following table summarizes accrued interest receivables associated with financial assets carried at amortized cost and securities available-for-sale along with the related allowance for credit losses, which are reported net in other assets on the consolidated balance sheet. These accrued interest receivables are excluded from the amortized cost basis disclosures presented elsewhere in these financial statements, including Note 4, "Securities," and Note 5, "Loans." March 31, 2020 (in millions) Accrued interest receivables: Loans $ 177 Securities held-to-maturity 32 Other financial assets measured at amortized cost 3 Securities available-for-sale 109 Total accrued interest receivables 321 Allowance for credit losses 3 Accrued interest receivables, net $ 318 During the three months ended March 31, 2020 , we charged-off accrued interest receivables by reversing interest income for loans of $1 million .

Loans Held for Sale

Loans Held for Sale	3 Months Ended
	Mar. 31, 2020
Receivables [Abstract]
Loans Held for Sale	Loans Held for Sale Loans held for sale consisted of the following: March 31, 2020 December 31, 2019 (in millions) Commercial loans: Real estate, including construction $ — $ 83 Business and corporate banking — 35 Global banking 234 94 Total commercial 234 212 Consumer loans: Residential mortgages 51 77 Total consumer 51 77 Total loans held for sale $ 285 $ 289 Commercial Loans Included in commercial loans held for sale are certain loans that we have elected to designate under the fair value option which consists of loans that we originate in connection with our participation in a number of syndicated credit facilities with the intent of selling them to unaffiliated third parties as well as loans that we purchase from the secondary market and hold as hedges against our exposure to certain total return swaps. The fair value of these loans totaled $206 million and $178 million at March 31, 2020 and December 31, 2019 , respectively. See Note 10, "Fair Value Option," for additional information. Commercial loans held for sale also includes certain loans that we no longer intend to hold for investment and were transferred to held for sale which totaled $28 million and $34 million at March 31, 2020 and December 31, 2019 , respectively. During both the three months ended March 31, 2020 and 2019, we recorded no lower of amortized cost or fair value adjustments on commercial loans held for sale. Consumer Loans Included in residential mortgage loans held for sale are agency-eligible residential mortgage loans which are originated and held for sale to third parties, currently on a servicing retained basis. Gains and losses from the sale of these residential mortgage loans are reflected as a component of other income (loss) in the consolidated statement of income (loss). Loans held for sale are subject to market risk, liquidity risk and interest rate risk, in that their value will fluctuate as a result of changes in market conditions, as well as the credit environment. Beginning with 2018 applications, interest rate risk for agency-eligible residential mortgage loans held for sale is partially mitigated through an economic hedging program to offset changes in the fair value of these mortgage loans held for sale, from the time of commitment to sale, attributable to changes in market interest rates. Revenue associated with this economic hedging program, which is reflected as a component of other income (loss) in the consolidated statement of income (loss), was losses of $3 million and $1 million during the three months ended March 31, 2020 and 2019 , respectively. Valuation Allowances Excluding the commercial loans designated under the fair value option discussed above, loans held for sale are recorded at the lower of amortized cost or fair value, with adjustments to fair value being recorded as a valuation allowance through other revenues. The valuation allowance on consumer loans held for sale was $1 million and $2 million at March 31, 2020 and December 31, 2019 , respectively. The valuation allowance on commercial loans held for sale was nil at both March 31, 2020 and December 31, 2019 .

Goodwill

Goodwill	3 Months Ended
	Mar. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill Goodwill was $458 million and $1,242 million at March 31, 2020 and December 31, 2019 , respectively. Goodwill for these periods reflects accumulated impairment losses of $1,819 million and $1,035 million , respectively. During the first quarter of 2020, as a result of the deterioration in economic conditions caused by the spread of the COVID-19 pandemic across the globe, including into the United States, and its impact on our businesses including changes to the interest rate environment as a result of recent FRB actions to combat the economic effects of the virus and the amount of headroom calculated in our previous annual impairment test for certain reporting units, we determined that it was more likely than not that the fair value of one or more of our reporting units was lower than their carrying amounts, including goodwill. Based on this analysis, we determined that an interim goodwill impairment test should be performed for all of our reporting units as of March 31, 2020 and prepared updated cash flow projections for each reporting unit, resulting in a reduction in the long-term forecasts of profitability for both our Retail Banking and Wealth Management and our Private Banking reporting units as compared to the prior year forecasts. These projections were reviewed by senior management in early April in connection with the preparation of our first quarter financial statements and it was determined that these forecasts represent our current best estimate of future profitability and would be used to conduct our interim impairment test. We completed our interim impairment test of goodwill utilizing cash flow projections based on these forecasts under a present value approach and, in conjunction with valuation estimates determined under a market approach, concluded that the fair value of our Commercial Banking reporting unit exceeded its carrying value, including goodwill. However, the cash flow projections for our Retail Banking and Wealth Management and our Private Banking reporting units were significantly lower which, in conjunction with valuation estimates under a market approach and in consideration of a challenging macroeconomic outlook, resulted in a fair value that was significantly lower than their book values, including goodwill. As a result, we recorded a non-cash impairment charge of $784 million in the first quarter of 2020, representing the entire amount of goodwill previously allocated to these reporting units. As discussed in our 2019 Form 10-K, our goodwill impairment testing is highly sensitive to certain assumptions and estimates used.

Derivative Financial Instrument

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments In the normal course of business, the derivative instruments we enter into are for trading, market making and risk management purposes. For financial reporting purposes, derivative instruments are designated in one of the following categories: (a) hedging instruments designated as qualifying hedges under derivative and hedge accounting principles, (b) financial instruments held for trading or (c) non-qualifying economic hedges. The derivative instruments held are predominantly swaps, futures, options and forward contracts. All derivatives are stated at fair value. Where we enter into enforceable master netting agreements with counterparties, the master netting agreements permit us to net those derivative asset and liability positions and to offset cash collateral held and posted with the same counterparty. The following table presents the fair value of derivative contracts by major product type on a gross basis. Gross fair values exclude the effects of both counterparty netting as well as collateral, and therefore are not representative of our exposure. The table below also presents the amounts of counterparty netting and cash collateral that have been offset in the consolidated balance sheet, as well as cash and securities collateral posted and received under enforceable master netting agreements that do not meet the criteria for netting. Derivative assets and liabilities which are not subject to an enforceable master netting agreement, or are subject to a netting agreement where an appropriate legal opinion to determine such agreements are enforceable has not been either sought or obtained, have not been netted in the following table. Where we have received or posted collateral under netting agreements where an appropriate legal opinion to determine such agreements are enforceable has not been either sought or obtained, the related collateral also has not been netted in the following table. March 31, 2020 December 31, 2019 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities (in millions) Derivatives accounted for as fair value hedges (1) OTC-cleared (2) $ — $ 2 $ — $ 1 Bilateral OTC (2) — 291 — 164 Interest rate contracts — 293 — 165 Derivatives accounted for as cash flow hedges (1) Foreign exchange contracts - bilateral OTC (2) 12 8 16 20 Interest rate contracts - bilateral OTC (2) — 2 — 1 Total derivatives accounted for as hedges 12 303 16 186 Trading derivatives not accounted for as hedges (3) Exchange-traded (2) 11 11 110 3 OTC-cleared (2) 126 17 167 29 Bilateral OTC (2) 19,494 22,164 11,990 13,324 Interest rate contracts 19,631 22,192 12,267 13,356 Exchange-traded (2) — 7 80 — OTC-cleared (2) 41 — — — Bilateral OTC (2) 31,072 29,727 16,440 15,786 Foreign exchange contracts 31,113 29,734 16,520 15,786 Exchange-traded (2) 1 — — — Bilateral OTC (2) 4,182 3,201 3,753 3,993 Equity contracts 4,183 3,201 3,753 3,993 Exchange-traded (2) — 147 71 80 Bilateral OTC (2) 2,211 2,040 1,087 1,309 Precious metals contracts 2,211 2,187 1,158 1,389 OTC-cleared (2) 85 — 1 — Bilateral OTC (2) 1,876 2,307 1,138 1,024 Credit contracts 1,961 2,307 1,139 1,024 Other non-qualifying derivatives not accounted for as hedges (1) Interest rate contracts - bilateral OTC (2) 211 5 128 51 Foreign exchange contracts - bilateral OTC (2) — 2 — — Equity contracts - bilateral OTC (2) 423 929 1,354 75 Credit contracts - bilateral OTC (2) 30 21 — 44 Other contracts - bilateral OTC (2)(4) 9 67 10 85 Total derivatives 59,784 60,948 36,345 35,989 Less: Gross amounts of receivable / payable subject to enforceable master netting agreements (5)(7) 48,099 48,099 29,510 29,510 Less: Gross amounts of cash collateral received / posted subject to enforceable master netting agreements (6)(7) 6,178 9,131 3,683 4,390 Net amounts of derivative assets / liabilities presented in the balance sheet 5,507 3,718 3,152 2,089 Less: Gross amounts of financial instrument collateral received / posted subject to enforceable master netting agreements but not offset in the consolidated balance sheet 1,443 552 891 553 Net amounts of derivative assets / liabilities $ 4,064 $ 3,166 $ 2,261 $ 1,536 (1) Derivative assets / liabilities related to cash flow hedges, fair value hedges and derivative instruments held for purposes other than for trading are recorded in other assets / interest, taxes and other liabilities on the consolidated balance sheet. (2) Over-the-counter ("OTC") derivatives include derivatives executed and settled bilaterally with counterparties without the use of an organized exchange or central clearing house. The credit risk associated with bilateral OTC derivatives is managed through obtaining collateral and enforceable master netting agreements. OTC-cleared derivatives are executed bilaterally in the OTC market but then novated to a central clearing counterparty, whereby the central clearing counterparty becomes the counterparty to each of the original counterparties. Exchange traded derivatives are executed directly on an organized exchange. Credit risk is minimized for OTC-cleared derivatives and exchange traded derivatives through daily margining requirements. In addition, OTC-cleared interest rate and credit derivatives with certain central clearing counterparties are settled daily. (3) Trading related derivative assets / liabilities are recorded in trading assets / trading liabilities on the consolidated balance sheet. (4) Consists of swap agreements entered into in conjunction with the sales of Visa Inc. ("Visa") Class B common shares ("Class B Shares"). (5) Represents the netting of derivative receivable and payable balances for the same counterparty under enforceable netting agreements. (6) Represents the netting of cash collateral posted and received by counterparty under enforceable netting agreements. (7) Netting is performed at a counterparty level in cases where enforceable master netting agreements are in place, regardless of the type of derivative instrument. Therefore, we have not allocated netting to the different types of derivative instruments shown in the table above. See Note 18, "Guarantee Arrangements, Pledged Assets and Repurchase Agreements," for further information on offsetting related to resale and repurchase agreements. Derivatives Held for Risk Management Purposes Our risk management policy requires us to identify, analyze and manage risks arising from the activities conducted during the normal course of business. We use derivative instruments as an asset and liability management tool to manage our exposures in interest rate, foreign currency and credit risks in existing assets and liabilities, commitments and forecasted transactions. The accounting for changes in fair value of a derivative instrument will depend on whether the derivative has been designated and qualifies for hedge accounting. We designate derivative instruments to offset the fair value risk and cash flow risk arising from fixed-rate and floating-rate assets and liabilities as well as forecasted transactions. We assess the hedging relationships, both at the inception of the hedge and on an ongoing basis, using a regression approach to determine whether the designated hedging instrument is highly effective in offsetting changes in the fair value or the cash flows attributable to the hedged risk. Accounting principles for qualifying hedges require us to prepare detailed documentation describing the relationship between the hedging instrument and the hedged item, including, but not limited to, the risk management objective, the hedging strategy and the methods to assess and measure the ineffectiveness of the hedging relationship. We discontinue hedge accounting when we determine that the hedge is no longer highly effective, the hedging instrument is terminated, sold or expired, the designated forecasted transaction is not probable of occurring, or when the designation is removed by us. Fair Value Hedges In the normal course of business, we hold fixed-rate loans and securities, and issue fixed-rate deposits and senior and subordinated debt obligations. The fair value of fixed-rate assets and liabilities fluctuates in response to changes in interest rates. We utilize interest rate swaps, forward and futures contracts to minimize our exposure to changes in fair value caused by interest rate volatility. The changes in the fair value of the hedged item designated in a qualifying hedge are captured as an adjustment to the carrying amount of the hedged item (basis adjustment). If the hedging relationship is discontinued and the hedged item continues to exist, the basis adjustment is amortized over the remaining life of the hedged item. The following table presents the carrying amount of hedged items in fair value hedges recognized in the consolidated balance sheet at March 31, 2020 and December 31, 2019 , along with the cumulative amount of fair value hedging adjustments included in the carrying amount of those hedged items: Carrying Amount of Hedged Items (1) Cumulative Amount of Fair Value Hedging Adjustments Increasing (Decreasing) the Carrying Amount of Hedged Items Active Discontinued Total (in millions) At March 31, 2020 Securities available-for-sale ("AFS") $ 10,928 $ 1,630 $ 356 $ 1,986 Deposits (2) 3,229 229 — 229 Long-term debt 5,927 326 (22 ) 304 At December 31, 2019 Securities available-for-sale ("AFS") 7,277 554 428 982 Long-term debt 10,975 285 (32 ) 253 (1) The carrying amount of securities AFS represents the amortized cost basis. (2) During the first quarter of 2020, $3.0 billion of fixed-rate senior debt obligations issued to HSBC North America were recharacterized as time deposits. The cumulative amount of fair value hedging adjustments associated with this debt was reclassified to deposits. See Note 14, "Related Party Transactions," for additional information. The following table presents information on gains and losses on derivative instruments designated and qualifying as hedging instruments and the hedged items in fair value hedges and their locations on the consolidated statement of income (loss): Location of Gain (Loss) Gain (Loss) on Derivatives Gain (Loss) on Hedged Items (in millions) Three Months Ended March 31, 2020 Interest rate contracts / Securities AFS Net interest income $ (1,156 ) $ 1,178 Interest rate contracts / Deposits Net interest income 120 (146 ) Interest rate contracts / Long-term debt Net interest income 177 (229 ) Total $ (859 ) $ 803 Three Months Ended March 31, 2019 Interest rate contracts / Securities AFS Net interest income $ (257 ) $ 350 Interest rate contracts / Long-term debt Net interest income 84 (199 ) Total $ (173 ) $ 151 Cash Flow Hedges We own or issue floating rate financial instruments and enter into forecasted transactions that give rise to variability in future cash flows. As a part of our risk management strategy, we use interest rate swaps, currency swaps and futures contracts to mitigate risk associated with variability in the cash flows. Changes in fair value of a derivative instrument associated with a qualifying cash flow hedge are recognized in other comprehensive income. When the cash flows being hedged materialize and are recorded in income or expense, the associated gain or loss from the hedging derivative previously recorded in accumulated other comprehensive income (loss) ("AOCI") is reclassified into earnings in the same accounting period in which the designated forecasted transaction or hedged item affects earnings. If a cash flow hedge of a forecasted transaction is discontinued because it is no longer highly effective, or if the hedge relationship is terminated, the cumulative gain or loss on the hedging derivative to that date will continue to be reported in AOCI unless it is probable that the hedged forecasted transaction will not occur by the end of the originally specified time period as documented at the inception of the hedge, at which time the cumulative gain or loss is released into earnings. At March 31, 2020 , active cash flow hedge relationships extend or mature through June 2031 . During the three months ended March 31, 2020 , $6 million of losses related to discontinued cash flow hedge relationships were amortized to earnings from AOCI compared with losses of $10 million during the three months ended March 31, 2019 . During the next twelve months, we expect to amortize $11 million of remaining losses to earnings resulting from these discontinued cash flow hedges. The interest accrual related to the hedging instruments is recognized in net interest income. The following table presents information on gains and losses on derivative instruments designated and qualifying as hedging instruments in cash flow hedges (including amounts recognized in AOCI from discontinued cash flow hedges) and their locations on the consolidated statement of income (loss): Gain (Loss) Recognized in AOCI on Derivatives Location of Gain (Loss) Reclassified from AOCI into Income Gain (Loss) Reclassified From AOCI into Income 2020 2019 2020 2019 (in millions) Three Months Ended March 31, Foreign exchange contracts $ — $ 1 Net interest income $ — $ — Interest rate contracts 113 7 Net interest income (6 ) (10 ) Total $ 113 $ 8 $ (6 ) $ (10 ) Trading Derivatives and Non-Qualifying Hedging Activities In addition to risk management, we also enter into derivative contracts, including buy- and sell-protection credit derivatives, for the purposes of trading and market making, or repackaging risks to form structured trades to meet clients' risk taking objectives. Additionally, we buy or sell securities and use derivatives to mitigate the market risks arising from our trading activities with our clients that exceed our risk appetite. We also use buy-protection credit derivatives to manage our counterparty credit risk exposure. Where we enter into derivatives for trading purposes, realized and unrealized gains and losses are recognized in trading revenue. Counterparty credit risk associated with OTC derivatives, including risk-mitigating buy-protection credit derivatives, are recognized as an adjustment to the fair value of the derivatives and are recorded in trading revenue. Our non-qualifying hedging and other activities include: • Derivative contracts related to the fixed-rate long-term debt issuances and hybrid instruments, including all structured notes and deposits, for which we have elected fair value option accounting. These derivative contracts are non-qualifying hedges but are considered economic hedges. • Credit default swaps which are designated as economic hedges against the credit risks within our loan portfolio. In the event of an impairment loss occurring in a loan that is economically hedged, the impairment loss is recognized as provision for credit losses while the gain on the credit default swap is recorded as other income (loss). • Swap agreements entered into in conjunction with the sales of Visa Class B Shares to a third party to retain the litigation risk associated with the Class B Shares sold until the related litigation is settled and the Class B Shares can be converted into Class A common shares ("Class A Shares"). See Note 18, "Guarantee Arrangements, Pledged Assets and Repurchase Agreements," for additional information. • Forward purchases or sales of to-be-announced ("TBA") securities used to economically hedge changes in the fair value of agency-eligible residential mortgage loans held for sale attributable to changes in market interest rates. Changes in the fair value of TBA positions, which are considered derivatives, are recorded in other income (loss). See Note 7, "Loans Held for Sale," for additional information. Derivative instruments designated as economic hedges that do not qualify for hedge accounting are recorded at fair value through profit and loss. Realized and unrealized gains and losses on economic hedges are recognized in loss on instruments designated at fair value and related derivatives or other income (loss) while the derivative asset or liability positions are reflected as other assets or other liabilities. The following table presents information on gains and losses on derivative instruments held for trading purposes and their locations on the consolidated statement of income (loss): Location of Gain (Loss) Recognized in Income on Derivatives Gain (Loss) Recognized in Income on Derivatives Three Months Ended March 31, 2020 2019 (in millions) Interest rate contracts Trading revenue $ 17 $ 56 Foreign exchange contracts (1) Trading revenue (665 ) (14 ) Equity contracts Trading revenue 1,257 (89 ) Precious metals contracts (1) Trading revenue 160 17 Credit contracts Trading revenue (657 ) (122 ) Total $ 112 $ (152 ) (1) During the third quarter of 2019, we changed our presentation for certain derivatives that were previously reported in foreign exchange contracts and began reporting these derivatives in precious metals contracts. As a result, we have reclassified $151 million of gains from foreign exchange contracts to precious metals contracts during the three months ended March 31, 2019 to conform with the current year presentation. The significant gains and losses recognized in trading revenue on derivatives during the three months ended March 31, 2020, primarily in foreign exchange, equity and credit contracts, reflect the impact of market volatility caused by the spread of the COVID-19 pandemic. The following table presents information on gains and losses on derivative instruments held for non-qualifying hedging and other activities and their locations on the consolidated statement of income (loss): Location of Gain (Loss) Recognized in Income on Derivatives Gain (Loss) Recognized in Income on Derivatives Three Months Ended March 31, 2020 2019 (in millions) Interest rate contracts Loss on instruments designated at fair value and related derivatives $ 250 $ 156 Interest rate contracts Other income (loss) (3 ) (1 ) Foreign exchange contracts Loss on instruments designated at fair value and related derivatives (2 ) (1 ) Equity contracts Loss on instruments designated at fair value and related derivatives (1,698 ) 914 Credit contracts Loss on instruments designated at fair value and related derivatives 37 — Credit contracts Other income (loss) 51 (10 ) Other contracts (1) Other income (loss) 11 (6 ) Total $ (1,354 ) $ 1,052 (1) Consists of swap agreements entered into in conjunction with the sales of Visa Class B Shares. Credit-Risk Related Contingent Features The majority of our derivative contracts contain provisions that require us to maintain a specific credit rating from each of the major credit rating agencies. Sometimes the derivative instrument transactions are a part of broader structured product transactions. If our credit ratings were to fall below the current ratings, the counterparties to our derivative instruments could demand us to post additional collateral. The amount of additional collateral required to be posted will depend on whether we are downgraded by one or more notches. The aggregate fair value of all derivative instruments with credit-risk related contingent features that were in a net liability position at March 31, 2020 was $1,220 million , for which we had posted collateral of $753 million . The aggregate fair value of all derivative instruments with credit-risk-related contingent features that were in a net liability position at December 31, 2019 was $611 million , for which we had posted collateral of $316 million . Substantially all of the collateral posted is in the form of cash or securities available-for-sale. See Note 18, "Guarantee Arrangements, Pledged Assets and Repurchase Agreements," for further details. The following table presents the amount of additional collateral that we would be required to post (from the current collateral level) related to derivative instruments with credit-risk related contingent features if our long-term ratings were downgraded by one or two notches. A downgrade by a single rating agency that does not result in a rating lower than a preexisting corresponding rating provided by another rating agency will generally not result in additional collateral. One-notch downgrade Two-notch downgrade (in millions) Amount of additional collateral to be posted upon downgrade $ 51 $ 100 Notional Value of Derivative Contracts The following table summarizes the notional values of derivative contracts: March 31, 2020 December 31, 2019 (in millions) Interest rate: Futures and forwards $ 765,243 $ 597,980 Swaps 1,938,082 2,130,442 Options written 116,380 158,861 Options purchased 121,867 164,265 2,941,572 3,051,548 Foreign exchange: Swaps, futures and forwards 1,304,885 1,362,959 Options written 35,269 44,876 Options purchased 36,088 46,085 Spot 44,391 67,060 1,420,633 1,520,980 Commodities, equities and precious metals: Swaps, futures and forwards 73,740 55,678 Options written 35,418 39,035 Options purchased 45,636 49,517 154,794 144,230 Credit derivatives 95,364 90,049 Other contracts (1) 895 1,044 Total $ 4,613,258 $ 4,807,851 (1) Consists of swap agreements entered into in conjunction with the sales of Visa Class B Shares.

Fair Value Option

Fair Value Option	3 Months Ended
	Mar. 31, 2020
Fair Value Option [Abstract]
Fair Value Option	Fair Value Option We report our results to HSBC in accordance with HSBC Group accounting and reporting policies ("Group Reporting Basis"), which apply International Financial Reporting Standards ("IFRSs") as issued by the International Accounting Standards Board ("IASB") and endorsed by the European Union ("EU"). We typically have elected to apply fair value option ("FVO") accounting to selected financial instruments to align the measurement attributes of those instruments under U.S. GAAP and the Group Reporting Basis and to simplify the accounting model applied to those financial instruments. We elected to apply FVO accounting to certain commercial loans held for sale, certain securities purchased and sold under resale and repurchase agreements, certain fixed-rate long-term debt issuances, all of our hybrid instruments, including structured notes and deposits, and, beginning January 1, 2020, certain student loans held for investment. Excluding the fair value movement on fair value option liabilities attributable to our own credit spread, which is recorded in other comprehensive income, changes in the fair value of fair value option assets and liabilities as well as the mark-to-market adjustment on the related derivatives and the net realized gains or losses on these derivatives are reported in loss on instruments designated at fair value and related derivatives in the consolidated statement of income (loss). Loans and Loans Held For Sale We elected to apply FVO accounting to certain commercial syndicated loans which are originated with the intent to sell and certain commercial loans that we purchased from the secondary market and hold as hedges against our exposure to certain total return swaps and include these loans as loans held for sale in the consolidated balance sheet. Beginning January 1, 2020, we also elected to apply FVO accounting to certain student loans held for investment. These elections allow us to account for these loans at fair value which is consistent with the manner in which the instruments are managed. Where available, fair value is based on observable market pricing obtained from independent sources, relevant broker quotes or observed market prices of instruments with similar characteristics. Where observable market parameters are not available, fair value is determined based on contractual cash flows adjusted for estimates of prepayment rates, expected default rates and loss severity discounted at management's estimate of the expected rate of return required by market participants. We also consider loan-specific risk mitigating factors such as collateral arrangements in determining the fair value estimate. Interest from these loans is recorded as interest income in the consolidated statement of income (loss). Because a substantial majority of the loans elected for the fair value option are floating rate commercial loans, changes in their fair value are primarily attributable to changes in loan-specific credit risk factors. The components of gain (loss) related to loans designated at fair value are summarized in the table below. At March 31, 2020 and December 31, 2019 , no loans for which the fair value option has been elected were 90 days or more past due or in nonaccrual status. Resale and Repurchase Agreements We elected to apply FVO accounting to certain securities purchased and sold under resale and repurchase agreements which are trading in nature. The election allows us to account for these resale and repurchase agreements at fair value which is consistent with the manner in which the instruments are managed. The fair value of the resale and repurchase agreements is determined using market rates currently offered on comparable transactions with similar underlying collateral and maturities. Interest on these resale and repurchase agreements is recorded as interest income or expense in the consolidated statement of income (loss). The components of gain (loss) related to these resale and repurchase agreements designated at fair value are summarized in the table below. Long-Term Debt (Own Debt Issuances) We elected to apply FVO accounting for certain fixed-rate long-term debt for which we had applied or otherwise would elect to apply fair value hedge accounting. The election allows us to achieve a similar accounting effect without having to meet the hedge accounting requirements. The own debt issuances elected under FVO are traded in secondary markets and, as such, the fair value is determined based on observed prices for the specific instruments. The observed market price of these instruments reflects the effect of changes to our own credit spreads and interest rates. Interest on the fixed-rate debt accounted for under FVO is recorded as interest expense in the consolidated statement of income (loss). Excluding the fair value movement attributable to our own credit spread, the components of gain (loss) in the consolidated statement of income (loss) related to long-term debt designated at fair value are summarized in the table below. Hybrid Instruments We elected to apply FVO accounting to all of our hybrid instruments issued, including structured notes and deposits. The valuation of the hybrid instruments is predominantly driven by the derivative features embedded within the instruments and our own credit risk. Cash flows of the hybrid instruments in their entirety, including the embedded derivatives, are discounted at an appropriate rate for the applicable duration of the instrument adjusted for our own credit spreads. The credit spreads applied to structured notes are determined with reference to our own debt issuance rates observed in the primary and secondary markets, internal funding rates, and structured note rates in recent executions while the credit spreads applied to structured deposits are determined using market rates currently offered on comparable deposits with similar characteristics and maturities. Interest on this debt is recorded as interest expense in the consolidated statement of income (loss). Excluding the fair value movement attributable to our own credit spread, the components of gain (loss) in the consolidated statement of income (loss) related to hybrid instruments designated at fair value are summarized in the table below. The following table summarizes the fair value and unpaid principal balance for items we account for under FVO: Fair Value Unpaid Principal Balance Fair Value Over (Under) Unpaid Principal Balance (in millions) At March 31, 2020 Student loans held for investment $ 37 $ 39 $ (2 ) Commercial loans held for sale 206 263 (57 ) Fixed rate long-term debt 898 741 157 Hybrid instruments: Structured deposits 6,371 7,278 (907 ) Structured notes 7,477 8,176 (699 ) At December 31, 2019 Commercial loans held for sale $ 178 $ 189 $ (11 ) Securities sold under repurchase agreements 373 373 — Fixed rate long-term debt 959 741 218 Hybrid instruments: Structured deposits 7,209 7,491 (282 ) Structured notes 9,388 8,187 1,201 Components of Loss on Instruments Designated at Fair Value and Related Derivatives The following table summarizes the components of loss on instruments designated at fair value and related derivatives reflected in the consolidated statement of income (loss) for the three months ended March 31, 2020 and 2019 : Loans and Loans Held for Sale Long-Term Debt Hybrid Instruments Total (in millions) Three Months Ended March 31, 2020 Interest rate and other components (1) $ — $ (134 ) $ 1,579 $ 1,445 Credit risk component (2)(3) (54 ) — — (54 ) Total mark-to-market on financial instruments designated at fair value (54 ) (134 ) 1,579 1,391 Mark-to-market on related derivatives 37 150 (1,606 ) (1,419 ) Net realized gain on related long-term debt derivatives — 6 — 6 Gain (loss) on instruments designated at fair value and related derivatives $ (17 ) $ 22 $ (27 ) $ (22 ) Three Months Ended March 31, 2019 Interest rate and other components (1) $ — $ (69 ) $ (1,012 ) $ (1,081 ) Credit risk component (2) 3 — — 3 Total mark-to-market on financial instruments designated at fair value 3 (69 ) (1,012 ) (1,078 ) Mark-to-market on related derivatives — 53 1,006 1,059 Net realized gain on related long-term debt derivatives — 10 — 10 Gain (loss) on instruments designated at fair value and related derivatives $ 3 $ (6 ) $ (6 ) $ (9 ) (1) As it relates to hybrid instruments, interest rate and other components primarily includes interest rate, foreign exchange and equity contract risks. (2) The fair value movement on fair value option liabilities attributable to our own credit spread is recorded in other comprehensive income. (3) During the three months ended March 31, 2020, the loss in the credit risk component for loans and loans held for sale was attributable to the widening of credit spreads associated with certain commercial loans held for sale which were impacted by the spread of the COVID-19 pandemic.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2020
Equity [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Income (Loss) Accumulated other comprehensive income (loss) includes certain items that are reported directly within a separate component of equity. The following table presents changes in accumulated other comprehensive income (loss) balances: Three Months Ended March 31, 2020 2019 (in millions) Unrealized gains (losses) on investment securities: Balance at beginning of period $ (116 ) $ (519 ) Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses on securities available-for-sale, net of tax of $1 million (1) 2 — Balance at beginning of period, adjusted (114 ) (519 ) Other comprehensive income (loss) for period: Net unrealized gains arising during period, net of tax of $245 million and $55 million, respectively 775 180 Reclassification adjustment for gains realized in net income (loss), net of tax of $(7) million and $(2) million, respectively (2) (21 ) (5 ) Reversal of provision for credit losses realized in net income (loss), net of tax of less than $1 million (3) 1 — Amortization of net unrealized losses on securities transferred from available-for-sale to held-to-maturity realized in net income (loss), net of tax of $1 million and $1 million, respectively (4) 3 4 Total other comprehensive income for period 758 179 Balance at end of period 644 (340 ) Unrealized gains (losses) on fair value option liabilities attributable to our own credit spread: Balance at beginning of period (9 ) 301 Other comprehensive income (loss) for period: Net unrealized gains (losses) arising during period, net of tax of $128 million and $(35) million, respectively 407 (111 ) Total other comprehensive income (loss) for period 407 (111 ) Balance at end of period 398 190 Unrealized gains (losses) on derivatives designated as cash flow hedges: Balance at beginning of period (151 ) (159 ) Other comprehensive income (loss) for period: Net unrealized gains arising during period, net of tax of $28 million and $2 million, respectively 85 6 Reclassification adjustment for losses realized in net income (loss), net of tax of $1 million and $2 million, respectively (5) 5 8 Total other comprehensive income for period 90 14 Balance at end of period (61 ) (145 ) Pension and postretirement benefit liability: Balance at beginning of period (3 ) 11 Other comprehensive income (loss) for period: Change in unfunded pension and postretirement liability, net of tax of nil and $(1) million, respectively — (3 ) Total other comprehensive loss for period — (3 ) Balance at end of period (3 ) 8 Total accumulated other comprehensive income (loss) at end of period $ 978 $ (287 ) (1) See Note 21, "New Accounting Pronouncements," for additional discussion. (2) Amount reclassified to net income (loss) is included in other securities gains, net in our consolidated statement of income (loss). (3) Changes in the allowance for credit losses on securities available-for-sale are included in the provision for credit losses in our consolidated statement of income (loss). (4) Amount amortized to net income (loss) is included in interest income in our consolidated statement of income (loss). During 2014, we transferred securities from available-for-sale to held-to-maturity. At the date of transfer, AOCI included net pretax unrealized losses related to the transferred securities which are being amortized over the remaining contractual life of each security as an adjustment of yield in a manner consistent with the amortization of any premium or discount. (5) Amount reclassified to net income (loss) is included in net interest income in our consolidated statement of income (loss).

Pension and Other Postretiremen

Pension and Other Postretirement Benefits	3 Months Ended
	Mar. 31, 2020
Retirement Benefits [Abstract]
Pension and Other Postretirement Benefits	Pension and Other Postretirement Benefits Defined Benefit Pension Plan The table below reflects the portion of pension expense and its related components of the combined HSBC North America Pension Plan (either the "HSBC North America Pension Plan" or the "Plan") which has been allocated to us and is recorded in our consolidated statement of income (loss). We have not been allocated any portion of the Plan's net pension liability. Three Months Ended March 31, 2020 2019 (in millions) Interest cost on projected benefit obligation $ 12 $ 15 Expected return on plan assets (19 ) (18 ) Amortization of net actuarial loss 2 7 Administrative costs 1 1 Pension (income) expense $ (4 ) $ 5 Postretirement Plans Other Than Pensions Certain employees also participate in plans which provide medical and life insurance benefits to retirees and eligible dependents. These plans cover all eligible employees who meet certain age and vested service requirements. We have instituted dollar limits on payments under the plans to control the cost of future medical benefits. Net periodic postretirement benefit cost was less than $1 million during both the three months ended March 31, 2020 and 2019 .

Fee Income from Contracts with

Fee Income from Contracts with Customers	3 Months Ended
	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Fee Income from Contracts with Customers	Fee Income from Contracts with Customers The following table summarizes fee income from contracts with customers disaggregated by type of activity, as well as a reconciliation to total other revenues, during the three months ended March 31, 2020 and 2019 . See Note 22, "Fee Income from Contracts with Customers," in our 2019 Form 10-K for a description of the various types of fee-based activities and how revenue associated with these activities is recognized. There have been no significant changes in these activities since December 31, 2019 . Three Months Ended March 31, 2020 2019 (in millions) Credit card fees, net $ 11 $ 12 Trust and investment management fees 31 30 Other fees and commissions: Account services 61 65 Credit facilities 73 69 Other fees 17 13 Total other fees and commissions 151 147 Servicing and other fees from HSBC affiliates 88 81 Insurance (1) 2 2 Total fee income from contracts with customers 283 272 Other non-fee revenues 104 118 Total other revenues (2) $ 387 $ 390 (1) Included within other income (loss) in the consolidated statement of income (loss). (2) 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. Credit card fees, net We recognized interchange fees of $22 million during both the three months ended March 31, 2020 and 2019 , respectively. Credit card rewards program costs totaled $13 million and $12 million during the three months ended March 31, 2020 and 2019 , respectively. Deferred Fee Income Information related to deferred fee income on loan commitments, revolving credit facilities and standby letters of credit is included in Note 18, "Guarantee Arrangements, Pledged Assets and Repurchase Agreements," and Note 19, "Fair Value Measurements." Excluding these items, we had deferred fee income related to certain account service fees that are paid upfront and recognized over the service period and annual fees on credit cards which collectively was $3 million and $2 million at March 31, 2020 and December 31, 2019 , respectively. We expect to recognize this revenue over a remaining period of one year or less. Other than trust and investment management fees as discussed in our 2019 Form 10-K, we do not use significant judgments in the determination of the amount and timing of fee income from contracts with customers. Additionally, costs to obtain or fulfill contracts with customers were immaterial.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions In the normal course of business, we conduct transactions with HSBC and its subsidiaries. HSBC policy requires that these transactions occur at prevailing market rates and terms and, where applicable, these transactions are compliant with United States banking regulations. All extensions of credit by (and certain credit exposures of) HSBC Bank USA, National Association (together with its subsidiaries, "HSBC Bank USA") to other HSBC affiliates (other than Federal Deposit Insurance Corporation insured banks) are legally required to be secured by eligible collateral. The following tables present related party balances and the income (expense) generated by related party transactions: March 31, 2020 December 31, 2019 (in millions) Assets: Cash and due from banks $ 199 $ 850 Interest bearing deposits with banks 97 40 Securities purchased under agreements to resell (1) 673 4,600 Trading assets 159 79 Loans 3,087 2,343 Other (2) 728 456 Total assets $ 4,943 $ 8,368 Liabilities: Deposits $ 17,360 $ 9,000 Trading liabilities 402 293 Short-term borrowings 5,418 1,166 Long-term debt 4,849 7,848 Other (2) 212 931 Total liabilities $ 28,241 $ 19,238 (1) Reflects purchases of securities under which other HSBC affiliates have agreed to repurchase. (2) Other assets and other liabilities primarily consist of derivative balances associated with hedging activities and other miscellaneous account receivables and payables. Three Months Ended March 31, 2020 2019 (in millions) Income (Expense): Interest income $ 26 $ 43 Interest expense (120 ) (124 ) Net interest expense (94 ) (81 ) Trading revenue (expense) (261 ) (1,514 ) Servicing and other fees from HSBC affiliates: HSBC Bank plc 47 35 HSBC Markets (USA) Inc. ("HMUS") 24 30 Other HSBC affiliates 17 16 Total servicing and other fees from HSBC affiliates 88 81 Gain (loss) on instruments designated at fair value and related derivatives (1,606 ) 1,008 Support services from HSBC affiliates: HTSU (263 ) (277 ) HMUS (27 ) (27 ) Other HSBC affiliates (92 ) (76 ) Total support services from HSBC affiliates (382 ) (380 ) Rental income from HSBC affiliates, net (1) 12 12 Stock based compensation expense (2) (6 ) (6 ) (1) We receive rental income from our affiliates, and in some cases pay rental expense to our affiliates, for rent on certain office space. Net rental income from our affiliates is recorded as a component of occupancy expense, net in our consolidated statement of income (loss). (2) Employees may participate in one or more stock compensation plans sponsored by HSBC. These expenses are included in salaries and employee benefits in our consolidated statement of income (loss). Certain employees are also eligible to participate in a defined benefit pension plan and other postretirement plans sponsored by HSBC North America which are discussed in Note 12, "Pension and Other Postretirement Benefits." Funding Arrangements with HSBC Affiliates: We use HSBC affiliates to fund a portion of our borrowing and liquidity needs. At March 31, 2020 and December 31, 2019 , long-term debt with affiliates reflected $4.8 billion and $7.8 billion , respectively, of borrowings from HSBC North America. During the first quarter of 2020, $3.0 billion of these borrowings were recharacterized as time deposits, including $1.5 billion of fixed-rate senior debt which matures in March 2021 and $1.5 billion of fixed-rate senior debt which matures in March 2026. The remaining outstanding balances include: • $2.0 billion of fixed-rate senior debt which matures in May 2021; • $0.8 billion of floating-rate subordinated debt which matures in May 2025; and • $2.0 billion of fixed-rate senior debt which matures in September 2025. We have a $150 million uncommitted line of credit with HSBC North America. There was no outstanding balance under this credit facility at either March 31, 2020 or December 31, 2019 . We have also incurred short-term borrowings with certain affiliates, largely securities sold under repurchase agreements with HSBC Securities (USA) Inc. ("HSI"). In addition, certain affiliates have also placed deposits with us. Lending and Derivative Related Arrangements Extended to HSBC Affiliates: At March 31, 2020 and December 31, 2019 , we had the following loan balances outstanding with HSBC affiliates: March 31, 2020 December 31, 2019 (in millions) HMUS and subsidiaries $ 3,032 $ 2,296 Other short-term affiliate lending 55 47 Total loans $ 3,087 $ 2,343 HMUS and subsidiaries We have extended loans and lines, some of them uncommitted, to HMUS and its subsidiaries in the amount of $12.0 billion at both March 31, 2020 and December 31, 2019 of which $3.0 billion and $2.3 billion , respectively, was outstanding. The maturities of the outstanding balances range from overnight to three months. Each borrowing is re-evaluated prior to its maturity date and either extended or allowed to mature. We have extended lines of credit to various other HSBC affiliates totaling $4.7 billion which did not have any outstanding balances at either March 31, 2020 or December 31, 2019 . Other short-term affiliate lending In addition to loans and lines extended to affiliates discussed above, from time to time we may extend loans to affiliates which are generally short term in nature. At March 31, 2020 and December 31, 2019 , there were $55 million and $47 million , respectively, of these loans outstanding. Derivative contracts As part of a global HSBC strategy to offset interest rate or other market risks associated with certain securities, debt issues and derivative contracts with unaffiliated third parties, we routinely enter into derivative transactions with HSBC Bank plc and other HSBC affiliates. The notional value of derivative contracts related to these transactions was approximately $1,005.3 billion and $1,111.5 billion at March 31, 2020 and December 31, 2019 , respectively. The net credit exposure (defined as the net fair value of derivative assets and liabilities, including any collateral received) related to the contracts was approximately $116 million and $90 million at March 31, 2020 and December 31, 2019 , respectively. Our Global Banking and Markets business accounts for these transactions on a mark to market basis, with the change in value of contracts with HSBC affiliates substantially offset by the change in value of related contracts entered into with unaffiliated third parties. Services Provided Between HSBC Affiliates: Under multiple service level agreements, we provide services to and receive services from various HSBC affiliates. These activities are summarized in Note 23, "Related Party Transactions," in our 2019 Form 10-K. There have been no significant changes in these activities since December 31, 2019. Other Transactions with HSBC Affiliates: At both March 31, 2020 and December 31, 2019 , we had $1,265 million of non-cumulative preferred stock issued and outstanding to HSBC North America. See Note 18, "Preferred Stock," in our 2019 Form 10-K for additional details.

Business Segments

Business Segments	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Business Segments	Business Segments We have five distinct business segments that we utilize for management reporting and analysis purposes, which are aligned with HSBC's global business strategy: Retail Banking and Wealth Management ("RBWM"), Commercial Banking ("CMB"), Global Banking and Markets ("GB&M"), Private Banking ("PB") and a Corporate Center ("CC"). There have been no changes in the basis of our segmentation as compared with the presentation in our 2019 Form 10-K. Net interest income of each segment represents the difference between actual interest earned on assets and interest incurred on liabilities of the segment, adjusted for a funding charge or credit that includes both interest rate and liquidity components. Segments are charged a cost to fund assets (e.g. customer loans) and receive a funding credit for funds provided (e.g. customer deposits) based on equivalent market rates that incorporate both repricing (interest rate risk) and tenor (liquidity) characteristics. The objective of these charges/credits is to transfer interest rate risk from the segments to one centralized unit in Balance Sheet Management, recognize term funding costs/benefits and more appropriately reflect the profitability of the segments. Certain other revenue and operating expense amounts are also apportioned among the business segments based upon the benefits derived from this activity or the relationship of this activity to other segment activity. These inter-segment transactions have not been eliminated, and we generally account for them as if they were with third parties. Our segment results are presented in accordance with HSBC Group accounting and reporting policies, which apply IFRSs as issued by the IASB and endorsed by the EU, and, as a result, our segment results are prepared and presented using financial information prepared on the Group Reporting Basis as operating results are monitored and reviewed, trends are evaluated and decisions about allocating resources, such as employees, are primarily made on this basis. We continue, however, to monitor capital adequacy and report to regulatory agencies on a U.S. GAAP basis. There have been no changes in the measurement of segment profit as compared with the presentation in our 2019 Form 10-K. A summary of significant differences between U.S. GAAP and the Group Reporting Basis as they impact our results are summarized in Note 24, "Business Segments," in our 2019 Form 10-K. Other than the changes discussed below, there have been no other significant changes since December 31, 2019 in the differences between U.S. GAAP and the Group Reporting Basis impacting our results. Expected credit losses - As discussed further in Note 21, "New Accounting Pronouncements," on January 1, 2020, we adopted new accounting guidance under U.S. GAAP which requires entities to recognize an allowance for credit losses based on lifetime ECL. However, under the Group Reporting Basis for the requirements of IFRS 9, "Financial Instruments" ("IFRS 9"), only financial assets which are considered to have experienced a significant increase in credit risk or for which there is objective evidence of impairment require an allowance based on lifetime ECL. Under the Group Reporting Basis, financial assets which have not experienced a significant increase in credit risk since initial recognition only require an allowance based on expected credit losses resulting from default events that are possible within the next 12 months. Principally as a result of this difference, the allowance for credit losses remains higher under U.S. GAAP than under the Group Reporting Basis. In addition, the new guidance requires inclusion of expected recoveries, limited to the cumulative amount of prior write-offs, when estimating the allowance for credit losses for in scope financial assets (including collateral-dependent assets) under U.S. GAAP, which results in an impact to earnings substantially consistent with the Group Reporting Basis. Prior to January 1, 2020, these expected recoveries were not recognized under U.S. GAAP. The following table summarizes the results for each segment on a Group Reporting Basis, as well as provides a reconciliation of total results under the Group Reporting Basis to U.S. GAAP consolidated totals: Group Reporting Basis Consolidated Amounts RBWM CMB GB&M PB CC Total Group Reporting Basis Adjustments (1) Group Reporting Basis Reclassi- fications (2) U.S. GAAP Consolidated Totals (in millions) Three Months Ended March 31, 2020 Net interest income $ 195 $ 208 $ 81 $ 31 $ 4 $ 519 $ 3 $ (18 ) $ 504 Other operating income 59 58 264 16 (26 ) 371 (4 ) 20 387 Total operating income 254 266 345 47 (22 ) 890 (1 ) 2 891 Expected credit losses / provision for credit losses 140 123 115 — 1 379 347 — 726 114 143 230 47 (23 ) 511 (348 ) 2 165 Operating expenses 660 146 187 370 146 1,509 94 2 1,605 Profit (loss) before income tax $ (546 ) $ (3 ) $ 43 $ (323 ) $ (169 ) $ (998 ) $ (442 ) $ — $ (1,440 ) Balances at end of period: Total assets $ 18,954 $ 31,540 $ 114,802 $ 7,159 $ 97,154 $ 269,609 $ (64,532 ) $ — $ 205,077 Total loans, net 17,701 30,370 22,461 6,084 2,039 78,655 (4,596 ) 6,738 80,797 Goodwill — 358 — — — 358 100 — 458 Total deposits 39,083 32,309 40,417 8,201 4,305 124,315 (7,066 ) 19,474 136,723 Three Months Ended March 31, 2019 Net interest income $ 221 $ 201 $ 151 $ 37 $ 14 $ 624 $ 6 $ (68 ) $ 562 Other operating income 65 58 175 16 24 338 (17 ) 69 390 Total operating income 286 259 326 53 38 962 (11 ) 1 952 Expected credit losses / provision for credit losses 21 6 (17 ) (1 ) 1 10 41 7 58 265 253 343 54 37 952 (52 ) (6 ) 894 Operating expenses 311 138 206 53 40 748 8 (6 ) 750 Profit (loss) before income tax $ (46 ) $ 115 $ 137 $ 1 $ (3 ) $ 204 $ (60 ) $ — $ 144 Balances at end of period: Total assets $ 18,733 $ 25,612 $ 78,899 $ 6,686 $ 79,715 $ 209,645 $ (28,724 ) $ — $ 180,921 Total loans, net 16,885 24,447 20,068 5,584 2,230 69,214 (1,797 ) 3,034 70,451 Goodwill 581 358 — 321 — 1,260 347 — 1,607 Total deposits 33,459 22,323 28,274 7,540 6,629 98,225 (2,827 ) 18,241 113,639 (1) Represents adjustments associated with differences between U.S. GAAP and the Group Reporting Basis. (2) Represents differences in financial statement presentation between U.S. GAAP and the Group Reporting Basis.

Retained Earnings and Regulator

Retained Earnings and Regulatory Capital Requirements	3 Months Ended
	Mar. 31, 2020
Banking and Thrift [Abstract]
Retained Earnings and Regulatory Capital Requirements	Retained Earnings and Regulatory Capital Requirements Bank dividends are one of the sources of funds used for payment of shareholder dividends and other HSBC USA cash needs. Approval from the Office of the Comptroller of the Currency ("OCC") is required if the total of all dividends HSBC Bank USA declares in any year exceeds the cumulative net income for that year, combined with the net income for the two preceding years reduced by dividends attributable to those years. OCC approval also is required for a reduction of permanent capital of HSBC Bank USA. Under a separate restriction, payment of dividends is prohibited in amounts greater than undivided profits then on hand, after deducting actual losses and bad debts. Bad debts are debts due and unpaid for a period of six months unless well secured, as defined, and in the process of collection. In March 2020, the FRB announced it had reduced its reserve requirement to zero percent. Prior to the announcement, HSBC Bank USA was required to maintain reserve balances either in the form of vault cash or on deposit with the Federal Reserve Bank, based on a percentage of deposits. At December 31, 2019 , HSBC Bank USA was required to maintain $2,475 million of reserve balances with the Federal Reserve Bank which were reported within interest bearing deposits with banks on the consolidated balance sheet. We are subject to regulatory capital rules issued by U.S. banking regulators including Basel III (the "Basel III rule"). A bank or bank holding company's failure to meet minimum capital requirements can result in certain mandatory actions and possibly additional discretionary actions by its regulators. The following table summarizes the capital amounts and ratios of HSBC USA and HSBC Bank USA, calculated in accordance with the Basel III rule at March 31, 2020 and December 31, 2019 : March 31, 2020 December 31, 2019 Capital Amount Well-Capitalized Ratio (1) Actual Ratio Capital Amount Well-Capitalized Ratio (1) Actual Ratio (dollars are in millions) Common equity Tier 1 ratio: HSBC USA $ 15,622 4.5 % (2) 11.9 % $ 15,876 4.5 % (2) 13.1 % HSBC Bank USA 17,814 6.5 14.0 18,043 6.5 15.2 Tier 1 capital ratio: HSBC USA 16,887 6.0 12.9 17,141 6.0 14.1 HSBC Bank USA 20,314 8.0 15.9 20,543 8.0 17.3 Total capital ratio: HSBC USA 20,932 10.0 16.0 19,743 10.0 16.3 HSBC Bank USA 23,063 10.0 18.1 22,724 10.0 19.2 Tier 1 leverage ratio: HSBC USA 16,887 4.0 (2) 9.0 17,141 4.0 (2) 9.9 HSBC Bank USA 20,314 5.0 11.0 20,543 5.0 12.0 Supplementary leverage ratio ("SLR"): HSBC USA 16,887 3.0 (3) 6.5 17,141 3.0 (3) 6.9 HSBC Bank USA 20,314 3.0 (3) 8.0 20,543 3.0 (3) 8.4 Risk-weighted assets: (4) HSBC USA 130,901 121,407 HSBC Bank USA 127,499 118,618 Adjusted quarterly average assets: (5) HSBC USA 187,962 173,270 HSBC Bank USA 184,851 170,722 Total leverage exposure: (6) HSBC USA 258,783 247,590 HSBC Bank USA 254,907 244,008 (1) HSBC USA and HSBC Bank USA are categorized as "well-capitalized," as defined by their principal regulators. To be categorized as well-capitalized under regulatory guidelines, a banking institution must have the ratios reflected in the above table, and must not be subject to a directive, order, or written agreement to meet and maintain specific capital levels. (2) There are no common equity Tier 1 or Tier 1 leverage ratio components in the definition of a well-capitalized bank holding company. The ratios shown are the regulatory minimums. (3) There is no SLR component in the definition of a well-capitalized banking institution. The ratios shown are the regulatory minimum ratios. (4) Calculated using the generally-applicable Standardized Approach. (5) Represents the Tier 1 leverage ratio denominator which reflects quarterly average assets adjusted for amounts permitted to be deducted from Tier 1 capital. (6) Represents the SLR denominator which includes adjusted quarterly average assets plus certain off-balance sheet exposures. In response to the COVID-19 pandemic, on March 31, 2020, the federal banking agencies issued an interim final rule that provides the option to transition in the regulatory capital impacts of the new current expected credit loss accounting standard over a five-year period. This option comes in addition to the separate three-year transition option already available. HSBC North America and HSBC Bank USA elected the five-year transition option and, as a result, beginning in 2020, capital ratios are reported in accordance with the transition rules in the interim final rule.

Variable Interest Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2020
Variable Interest Entities [Abstract]
Variable Interest Entities	Variable Interest Entities In the ordinary course of business, we have organized special purpose entities ("SPEs") primarily to structure financial products to meet our clients' investment needs, to facilitate clients to access and raise financing from capital markets and to securitize financial assets held to meet our own funding needs. For disclosure purposes, we aggregate SPEs based on the purpose, risk characteristics and business activities of the SPEs. An SPE is a VIE if it lacks sufficient equity investment at risk to finance its activities without additional subordinated financial support or, as a group, the holders of the equity investment at risk lack either a) the power through voting or similar rights to direct the activities of the entity that most significantly impacts the entity's economic performance; or b) the obligation to absorb the entity's expected losses, the right to receive the expected residual returns, or both. Variable Interest Entities We consolidate VIEs in which we hold a controlling financial interest as evidenced by the power to direct the activities of a VIE that most significantly impact its economic performance and the obligation to absorb losses of, or the right to receive benefits from, the VIE that could potentially be significant to the VIE and therefore are deemed to be the primary beneficiary. We take into account our entire involvement in a VIE (explicit or implicit) in identifying variable interests that individually or in the aggregate could be significant enough to warrant our designation as the primary beneficiary and hence require us to consolidate the VIE or otherwise require us to make appropriate disclosures. We consider our involvement to be potentially significant where we, among other things, (i) enter into derivative contracts to absorb the risks and benefits from the VIE or from the assets held by the VIE; (ii) provide a financial guarantee that covers assets held or liabilities issued by a VIE; (iii) sponsor the VIE in that we design, organize and structure the transaction; and (iv) retain a financial or servicing interest in the VIE. We are required to evaluate whether to consolidate a VIE when we first become involved and on an ongoing basis. In almost all cases, a qualitative analysis of our involvement in the entity provides sufficient evidence to determine whether we are the primary beneficiary. In rare cases, a more detailed analysis to quantify the extent of variability to be absorbed by each variable interest holder is required to determine the primary beneficiary. Consolidated VIEs The following table summarizes assets and liabilities related to our consolidated VIEs at March 31, 2020 and December 31, 2019 which are consolidated on our balance sheet. Assets and liabilities exclude intercompany balances that eliminate in consolidation. March 31, 2020 December 31, 2019 Consolidated Assets Consolidated Liabilities Consolidated Assets Consolidated Liabilities (in millions) Low income housing limited liability partnership: Other assets $ 92 $ — $ 98 $ — Interest, taxes and other liabilities — 31 — 38 Subtotal 92 31 98 38 Venture debt financing entity: Loans 39 — — — Interest, taxes and other liabilities — 1 — — Subtotal 39 1 — — Total $ 131 $ 32 $ 98 $ 38 Low income housing limited liability partnership In 2009, all low income housing investments held by us at the time were transferred to a Limited Liability Partnership ("LLP") in exchange for debt and equity while a third party invested cash for an equity interest that was mandatorily redeemable. The LLP was created in order to ensure the utilization of future tax benefits from these low income housing tax projects. The LLP was deemed to be a VIE as it does not have sufficient equity investment at risk to finance its activities. Upon entering into this transaction, we concluded that we were the primary beneficiary of the LLP due to the nature of our continuing involvement and, as a result, we consolidated the LLP and reported the equity interest issued to the third party investor in long-term debt and the assets of the LLP in other assets on our consolidated balance sheet. The investments held by the LLP represent equity investments in the underlying low income housing partnerships. The LLP does not consolidate the underlying partnerships because it does not have the power to direct the activities of the partnerships that most significantly impact the economic performance of the partnerships. In 2019, the equity interest issued to the third party investor was redeemed. As a practical expedient, we amortize our low income housing investments in proportion to the allocated tax benefits under the proportional amortization method and present the associated tax benefits net of investment amortization in income tax expense (benefit). Venture debt financing entity During 2019, HSBC USA organized and provided equity financing to HSBC Ventures USA Inc. ("HSBC Ventures"), an entity designed to provide debt financing to venture capital-backed companies generally in the form of term or revolving loans, or loan commitments. Given the typically early stage and development of the companies, the loans are usually collateralized by all of the company's assets and intellectual property, or by specific items such as receivables or equipment. The loan terms may, at times, also include warrants for company stock granting HSBC Ventures a share of the financial returns in case of a positive realization event. HSBC USA also provides debt financing to HSBC Ventures in the form of loans on an as-needed basis. HSBC Ventures is a VIE because it does not have sufficient equity investment at risk to finance its activities. As the sole investor, HSBC USA is considered to be the primary beneficiary because it has the obligation to absorb losses and the right to receive benefits that could be potentially significant to HSBC Ventures. As a result, we consolidate HSBC Ventures and report the third party loans and warrants, if any, on our consolidated balance sheet. Unconsolidated VIEs We also have variable interests in other VIEs that are not consolidated because we are not the primary beneficiary. The following table provides additional information on these unconsolidated VIEs, including the variable interests held by us and our maximum exposure to loss arising from our involvements in these VIEs, at March 31, 2020 and December 31, 2019 : Total Assets Held by Unconsolidated VIEs Carrying Value of Variable Interests Held Reported as Maximum Exposure to Loss Assets Liabilities (in millions) At March 31, 2020 Structured note vehicles $ 1,657 $ 510 $ 142 $ 1,515 Limited partnership investments 2,149 591 307 591 Total $ 3,806 $ 1,101 $ 449 $ 2,106 At December 31, 2019 Structured note vehicles $ 1,524 $ 510 $ 9 $ 1,515 Limited partnership investments 2,160 561 300 562 Total $ 3,684 $ 1,071 $ 309 $ 2,077 Information on the types of VIEs with which we are involved, the nature of our involvement and the variable interests held in those entities is presented below. Structured note vehicles We provide derivatives, such as interest rate and currency swaps, to structured note vehicles and, in certain instances, invest in the vehicles' debt instruments. We hold variable interests in these structured note vehicles in the form of total return swaps under which we take on the risks and benefits of the structured notes they issue. The same risks and benefits are passed on to third party entities through back-end total return swaps. We earn a spread for facilitating the transaction. Since we do not have the power to direct the activities of the VIE and are not the primary beneficiary, we do not consolidate them. Our maximum exposure to loss is the notional amount of the derivatives wrapping the structured notes. The maximum exposure to loss of $1,515 million at March 31, 2020 would occur in the unlikely scenario where the value of the structured notes is reduced to zero and, at the same time, the counterparty of the back-end swap defaults with zero recovery. In certain instances, we hold credit default swaps with the structured note vehicles under which we receive credit protection on specified reference assets in exchange for the payment of a premium. Through these derivatives, the vehicles assume the credit risk associated with the reference assets which are then passed on to the holders of the debt instruments they issue. Because they create rather than absorb variability, the credit default swaps we hold are not considered variable interests. We record all investments in, and derivative contracts with, unconsolidated structured note vehicles at fair value on our consolidated balance sheet. During the first quarter of 2019, one of the structured note vehicles was unwound and our investment in the structured note vehicle along with the related derivatives were terminated. As a result, we recognized a loss of approximately $39 million , reflecting a payment made to the derivative counterparty as a result of the termination. At the time of unwind, our investment in the structured note vehicle had a total carrying value of $1,293 million , which was recorded in trading assets on the consolidated balance sheet. Limited partnership investments We invest as a limited partner in partnerships that operate qualified affordable housing, renewable energy and community development projects. The returns of these investments are generated primarily from the tax benefits, including Federal tax credits and tax deductions from operating losses in the project companies. In addition, some of the investments also help us comply with the Community Reinvestment Act. Certain limited partnership structures are considered to be VIEs because either (a) they do not have sufficient equity investment at risk or (b) the limited partners with equity at risk do not have substantive kick-out rights through voting rights or substantive participating rights over the general partner. As a limited partner, we are not the primary beneficiary of the VIEs and do not consolidate them. Our investments in these partnerships are recorded in other assets on the consolidated balance sheet. The maximum exposure to loss shown in the table above represents our recorded investments as well as any outstanding funding commitments extended to the partnerships. Third-party sponsored securitization entities We invest in asset-backed securities issued by third party sponsored securitization entities which may be considered VIEs. The investments are transacted at arm's-length and decisions to invest are based on a credit analysis of the underlying collateral assets or the issuer. We are a passive investor in these issuers and do not have the power to direct the activities of these issuers. As such, we do not consolidate these securitization entities. Additionally, we do not have other involvements in servicing or managing the collateral assets or provide financial or liquidity support to these issuers which potentially give rise to risk of loss exposure. These investments are an integral part of the disclosure in Note 3, "Trading Assets and Liabilities," Note 4, "Securities," and Note 19, "Fair Value Measurements," and, therefore, are not disclosed in this note to avoid redundancy.

Guarantee Arrangements, Pledged

Guarantee Arrangements, Pledged Assets and Repurchase Agreements	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Guarantee Arrangements, Pledged Assets and Repurchase Agreements	Guarantee Arrangements, Pledged Assets and Repurchase Agreements Guarantee Arrangements As part of our normal operations, we enter into credit derivatives and various off-balance sheet guarantee arrangements with affiliates and third parties. These arrangements arise principally in connection with our lending and client intermediation activities and include standby letters of credit and certain credit derivative transactions. The contractual amounts of these arrangements represent our maximum possible credit exposure in the event that we are required to fulfill the maximum obligation under the contractual terms of the guarantee. The following table presents total carrying value and contractual amounts of our sell protection credit derivatives and major off-balance sheet guarantee arrangements at March 31, 2020 and December 31, 2019 . Following the table is a description of the various arrangements. March 31, 2020 December 31, 2019 Carrying Value Notional / Maximum Exposure to Loss Carrying Value Notional / Maximum Exposure to Loss (in millions) Credit derivatives (1)(2) $ (2,064 ) $ 41,036 $ (63 ) $ 38,739 Financial standby letters of credit, net of participations (3)(4) — 5,805 — 5,657 Performance standby letters of credit, net of participations (3)(4) — 3,687 — 3,779 Total $ (2,064 ) $ 50,528 $ (63 ) $ 48,175 (1) Includes $19,399 million and $18,391 million of notional issued for the benefit of HSBC affiliates at March 31, 2020 and December 31, 2019 , respectively. (2) For credit derivatives, the maximum loss is represented by the notional amounts without consideration of mitigating effects from collateral or recourse arrangements. (3) Includes $1,649 million and $1,623 million of both financial and performance standby letters of credit issued for the benefit of HSBC affiliates at March 31, 2020 and December 31, 2019 , respectively. (4) For standby letters of credit, maximum loss represents losses to be recognized assuming the letters of credit have been fully drawn and the obligors have defaulted with zero recovery. Credit-Risk Related Guarantees Credit derivatives Credit derivatives are financial instruments that transfer the credit risk of a reference obligation from the credit protection buyer to the credit protection seller who is exposed to the credit risk without buying the reference obligation. We sell credit protection on underlying reference obligations (such as loans or securities) by entering into credit derivatives, primarily in the form of credit default swaps, with various institutions. We account for all credit derivatives at fair value. Where we sell credit protection to a counterparty that holds the reference obligation, the arrangement is effectively a financial guarantee on the reference obligation. Under a credit derivative contract, the credit protection seller will reimburse the credit protection buyer upon occurrence of a credit event (such as bankruptcy, insolvency, restructuring or failure to meet payment obligations when due) as defined in the derivative contract, in return for a periodic premium. Upon occurrence of a credit event, we will pay the counterparty the stated notional amount of the derivative contract and receive the underlying reference obligation. The recovery value of the reference obligation received could be significantly lower than its notional principal amount when a credit event occurs. Certain derivative contracts are subject to master netting arrangements and related collateral agreements. A party to a derivative contract may demand that the counterparty post additional collateral in the event its net exposure exceeds certain predetermined limits and when the credit rating falls below a certain grade. We set the collateral requirements by counterparty such that the collateral covers various transactions and products, and is not allocated to specific individual contracts. We manage our exposure to credit derivatives using a variety of risk mitigation strategies where we enter into offsetting hedge positions or transfer the economic risks, in part or in entirety, to investors through the issuance of structured credit products. We actively manage the credit and market risk exposure in the credit derivative portfolios on a net basis and, as such, retain no or a limited net position at any time. The following table summarizes our net credit derivative positions at March 31, 2020 and December 31, 2019 : March 31, 2020 December 31, 2019 Carrying / Fair Value Notional Carrying / Fair Value Notional (in millions) Sell-protection credit derivative positions $ (2,064 ) $ 41,036 $ (63 ) $ 38,739 Buy-protection credit derivative positions 1,783 54,328 77 51,310 Net position (1) $ (281 ) $ 13,292 $ 14 $ 12,571 (1) Positions are presented net in the table above to provide a complete analysis of our risk exposure and depict the way we manage our credit derivative portfolio. The offset of the sell-protection credit derivatives against the buy-protection credit derivatives may not be legally binding in the absence of master netting agreements with the same counterparty. Furthermore, the credit loss triggering events for individual sell protection credit derivatives may not be the same or occur in the same period as those of the buy protection credit derivatives thereby not providing an exact offset. Standby letters of credit A standby letter of credit is issued to a third party for the benefit of a client and is a guarantee that the client will perform or satisfy certain obligations under a contract. It irrevocably obligates us to pay a specified amount to the third party beneficiary if the client fails to perform the contractual obligation. We issue two types of standby letters of credit: performance and financial. A performance standby letter of credit is issued where the client is required to perform some non-financial contractual obligation, such as the performance of a specific act, whereas a financial standby letter of credit is issued where the client's contractual obligation is of a financial nature, such as the repayment of a loan or debt instrument. The issuance of a standby letter of credit is subject to our credit approval process and collateral requirements. We charge fees for issuing letters of credit commensurate with the client's credit evaluation and the nature of any collateral. Included in other liabilities are deferred fees on standby letters of credit amounting to $52 million at both March 31, 2020 and December 31, 2019 . Also included in other liabilities is an allowance for credit losses on unfunded standby letters of credit of $44 million and $26 million at March 31, 2020 and December 31, 2019 , respectively. The following table summarizes the credit ratings related to guarantees including the ratings of counterparties against which we sold credit protection and financial standby letters of credit at March 31, 2020 as an indicative proxy of payment risk: Average Life (in years) Credit Ratings of the Obligors Notional/Contractual Amounts Investment Non-Investment Grade Total (dollars are in millions) Sell-protection Credit Derivatives (1) Single name credit default swaps ("CDS") 3.2 $ 20,231 $ 9,090 $ 29,321 Index credit derivatives 4.3 6,159 4,300 10,459 Total return swaps 2.3 1,062 194 1,256 Subtotal 27,452 13,584 41,036 Standby Letters of Credit (2) 1.2 7,598 1,894 9,492 Total $ 35,050 $ 15,478 $ 50,528 (1) The credit ratings in the table represent external credit ratings for classification as investment grade and non-investment grade. (2) External ratings for most of the obligors are not available. Presented above are the internal credit ratings which are developed using similar methodologies and rating scale equivalent to external credit ratings for purposes of classification as investment grade and non-investment grade. Our internal credit ratings are determined based on HSBC's risk rating systems and processes which assign a credit grade based on a scale which ranks the risk of default of a client. The credit grades are assigned and used for managing risk and determining level of credit exposure appetite based on the client's operating performance, liquidity, capital structure and debt service ability. In addition, we also incorporate subjective judgments into the risk rating process concerning such things as industry trends, comparison of performance to industry peers and perceived quality of management. We compare our internal risk ratings to outside external rating agency benchmarks, where possible, at the time of formal review and regularly monitor whether our risk ratings are comparable to the external ratings benchmark data. A non-investment grade rating of a referenced obligor has a negative impact to the fair value of the credit derivative and increases the likelihood that we will be required to perform under the credit derivative contract. We employ market-based parameters and, where possible, use the observable credit spreads of the referenced obligors as measurement inputs in determining the fair value of the credit derivatives. We believe that such market parameters are more indicative of the current status of payment/performance risk than external ratings by the rating agencies which may not be forward-looking in nature and, as a result, lag behind those market-based indicators. Non Credit-Risk Related Guarantees and Other Arrangements Visa covered litigation In 2008, we received Class B Shares as part of Visa's initial public offering ("IPO"). Pursuant to the IPO, we, along with all the other Class B shareholders, agreed to indemnify Visa for the claims and obligations arising from certain specific covered litigation. The Class B Shares are not eligible to be converted into publicly traded Class A Shares until settlement of the covered litigation described in Note 29, "Litigation and Regulatory Matters" in our 2019 Form 10-K. Accordingly, the Class B Shares are considered restricted and are only transferable under limited circumstances, which include transfers to other Class B shareholders. In 2017, we sold substantially all of our remaining Visa Class B Shares to a third party. Under the terms of the sale agreements, we entered into swap agreements with the purchaser to retain the litigation risk associated with the Class B Shares sold until the related litigation is settled and the Class B Shares can be converted into Class A Shares. These swaps had a carrying value of $67 million and $85 million at March 31, 2020 and December 31, 2019 , respectively. The swap agreements we entered into with the purchaser requires us to (a) make periodic payments, calculated by reference to the market price of Class A Shares and (b) make or receive payments based on subsequent changes in the conversion rate of Class B Shares into Class A Shares. We have entered into a total return swap position to economically hedge the periodic payments made under these swap agreements. The payments under the derivative will continue until the Class B Shares are able to be converted into Class A Shares. The fair value of the swap agreements is estimated using a discounted cash flow methodology and is dependent upon the final resolution of the related litigation. Changes in fair value between periods are recognized in other income (loss). See Note 9, "Derivative Financial Instruments," for further information. Clearing houses and exchanges We are a member of various exchanges and clearing houses that trade and clear securities and/or derivatives contracts. Under the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, members of a clearing house may be required to contribute to a guaranty fund to backstop members' obligations to the clearing house. As a member, we may be required to pay a proportionate share of the financial obligations of another member who defaults on its obligations to the exchange or the clearing house. Our guarantee obligations would arise only if the exchange or clearing house had exhausted its resources. Any potential contingent liability under these membership agreements cannot be estimated. Lease Obligations We are obligated under a number of noncancellable operating leases for premises and equipment. See Note 10, "Leases" in our 2019 Form 10-K, for a full discussion of our leases, including a maturity analysis of our operating lease liabilities. Mortgage Loan Repurchase Obligations We have provided various representations and warranties related to the origination and sale of mortgage loans including, among other things, the ownership of the loans, the validity of the liens, the loan selection and origination process, and the compliance to the origination criteria established by the government agencies. In the event of a breach of our representations and warranties, we may be obligated to repurchase the loans with identified defects or to indemnify the buyers. Our contractual obligation arises only when the breach of representations and warranties are discovered and repurchase is demanded. From 2013 to 2017, we sold agency-eligible mortgage loan originations directly to PHH Mortgage Corporation and they are responsible for origination representations and warranties for all such loans. With the insourcing of our mortgage fulfillment operations, beginning with 2018 applications, we are now responsible for origination representations and warranties for all agency-eligible mortgage loan originations sold to third parties. In estimating our repurchase liability arising from breaches of representations and warranties, we consider historical losses on residual risks not covered by settlement agreements adjusted for any risk factors not captured in the historical losses as well as the level of outstanding repurchase demands received. Outstanding repurchase demands received were immaterial at both March 31, 2020 and December 31, 2019 . There were no changes in our estimated repurchase liability during both the three months ended March 31, 2020 and 2019 for obligations arising from the breach of representations and warranties associated with mortgage loans sold. Our repurchase liability of $4 million at March 31, 2020 represents our best estimate of the loss that has been incurred, including interest, arising from breaches of representations and warranties associated with mortgage loans sold. Because the level of mortgage loan repurchase losses is dependent upon economic factors, investor demand strategies and other external risk factors such as housing market trends that may change, the level of the liability for mortgage loan repurchase losses requires significant judgment. We continue to evaluate our methods of determining the best estimate of loss based on recent trends. As these estimates are influenced by factors outside our control, there is uncertainty inherent in these estimates making it reasonably possible that they could change. The range of reasonably possible losses in excess of our recorded repurchase liability is between zero and $25 million at March 31, 2020 . This estimated range of reasonably possible losses was determined based upon modifying the assumptions utilized in our best estimate of probable losses to reflect what we believe to be reasonably possible adverse assumptions. Securitization Activity In addition to the repurchase risk described above, we have also been involved as a sponsor/seller of loans used to facilitate whole loan securitizations underwritten by our affiliate, HSI. In this regard, we began acquiring residential mortgage loans in 2005 which were warehoused on our balance sheet with the intent of selling them to HSI to facilitate HSI's whole loan securitization program which was discontinued in 2007. During 2005-2007, we purchased and sold $24 billion of such loans to HSI which were subsequently securitized and sold by HSI to third parties. See "Mortgage Securitization Matters" in Note 29, "Litigation and Regulatory Matters," in our 2019 Form 10-K for additional discussion of related exposure. The outstanding principal balance on these loans was approximately $3.4 billion at both March 31, 2020 and December 31, 2019 . Pledged Assets Pledged assets included in the consolidated balance sheet consisted of the following: March 31, 2020 December 31, 2019 (in millions) Interest bearing deposits with banks $ 4,816 $ 2,682 Trading assets (1) 6,633 525 Securities available-for-sale (2) 14,986 6,814 Securities held-to-maturity (2) 1,573 1,688 Loans (3) 13,316 14,342 Other assets (4) 6,634 3,517 Total $ 47,958 $ 29,568 (1) Trading assets are primarily pledged against liabilities associated with repurchase agreements. (2) Securities are primarily pledged against derivatives, public fund deposits, trust deposits and various short-term and long term borrowings, as well as providing capacity for potential secured borrowings from the FHLB and the Federal Reserve Bank of New York. (3) Loans are primarily residential mortgage loans pledged against current and potential borrowings from the FHLB and the Federal Reserve Bank of New York. (4) Other assets represent cash on deposit with non-banks related to derivative collateral support agreements. Debt securities pledged as collateral under repurchase agreements that can be sold or repledged by the secured party continue to be reported on the consolidated balance sheet. The fair value of securities available-for-sale that could be sold or repledged was $7,760 million and nil at March 31, 2020 and December 31, 2019 , respectively. The fair value of trading assets that could be sold or repledged was $6,633 million and $336 million at March 31, 2020 and December 31, 2019 , respectively. The fair value of collateral we accepted under security resale agreements but was not reported on the consolidated balance sheet was $8,324 million and $19,174 million at March 31, 2020 and December 31, 2019 , respectively. Of this collateral, $7,199 million and $18,199 million could be sold or repledged at March 31, 2020 and December 31, 2019 , respectively, of which $1,853 million and $2,062 million , respectively, had been sold or repledged as collateral under repurchase agreements or to cover short sales. Repurchase Agreements We enter into purchases of securities under agreements to resell (resale agreements) and sales of securities under agreements to repurchase (repurchase agreements) identical or substantially the same securities. Resale and repurchase agreements are accounted for as secured lending and secured borrowing transactions, respectively. Repurchase agreements may require us to deposit cash or other collateral with the lender. In connection with resale agreements, it is our policy to obtain possession of collateral, which may include the securities purchased, with market value in excess of the principal amount loaned. The market value of the collateral subject to the resale and repurchase agreements is regularly monitored, and additional collateral is obtained or provided when appropriate, to ensure appropriate collateral coverage of these secured financing transactions. The following table provides information about resale and repurchase agreements that are subject to offset at March 31, 2020 and December 31, 2019 : Gross Amounts Not Offset in the Balance Sheet Gross Amounts Recognized Gross Amounts Offset in the Balance Sheet (1) Net Amounts Presented in the Balance Sheet Financial Instruments (2) Cash Collateral Received / Pledged Net Amount (3) (in millions) At March 31, 2020 Assets: Securities purchased under resale agreements $ 8,241 $ 3,598 $ 4,643 $ 4,641 $ — $ 2 Liabilities: Securities sold under repurchase agreements $ 16,096 $ 3,598 $ 12,498 $ 12,453 $ — $ 45 At December 31, 2019 Assets: Securities purchased under resale agreements $ 19,167 $ 1,329 $ 17,838 $ 17,832 $ — $ 6 Liabilities: Securities sold under repurchase agreements $ 2,401 $ 1,329 $ 1,072 $ 1,068 $ — $ 4 (1) Represents recognized amount of resale and repurchase agreements with counterparties subject to legally enforceable netting agreements that meet the applicable netting criteria as permitted by generally accepted accounting principles. (2) Represents securities received or pledged to cover financing transaction exposures. (3) Represents the amount of our exposure that is not collateralized / covered by pledged collateral. The following table provides the class of collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings at March 31, 2020 and December 31, 2019 : Overnight and Continuous Up to 30 Days 31 to 90 Days 91 Days to One Year Greater Than One Year Total (in millions) At March 31, 2020 U.S. Treasury, U.S. Government sponsored and U.S. Government agency securities $ 6,719 $ 6,148 $ 3,229 $ — $ — $ 16,096 At December 31, 2019 U.S. Treasury, U.S. Government sponsored and U.S. Government agency securities $ 2,401 $ — $ — $ — $ — $ 2,401

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Accounting principles related to fair value measurements provide a framework for measuring fair value that focuses on the exit price that would be received to sell an asset or paid to transfer a liability in the principal market (or in the absence of the principal market, the most advantageous market) accessible in an orderly transaction between willing market participants (the "Fair Value Framework"). Where required by the applicable accounting standards, assets and liabilities are measured at fair value using the "highest and best use" valuation premise. Fair value measurement guidance clarifies that financial instruments do not have alternative use and, as such, the fair value of financial instruments should be determined using an "in-exchange" valuation premise. However, the fair value measurement literature provides a valuation exception and permits an entity to measure the fair value of a group of financial assets and financial liabilities with offsetting credit risks and/or market risks based on the exit price it would receive or pay to transfer the net risk exposure of a group of assets or liabilities if certain conditions are met. We elected to apply the measurement exception to a group of derivative instruments with offsetting credit risks and market risks, which primarily relate to interest rate, foreign currency, debt and equity price risk, and commodity price risk as of the reporting date. Fair Value Adjustments The best evidence of fair value is quoted market price in an actively traded market, where available. In the event listed price or market quotes are not available, valuation techniques that incorporate relevant transaction data and market parameters reflecting the attributes of the asset or liability under consideration are applied. Where applicable, fair value adjustments are made to ensure the financial instruments are appropriately recorded at fair value. The fair value adjustments reflect the risks associated with the products, contractual terms of the transactions, and the liquidity of the markets in which the transactions occur. The fair value adjustments are broadly categorized by the following major types: Credit valuation adjustment - The credit valuation adjustment is an adjustment to a group of financial assets and financial liabilities, predominantly derivative assets and derivative liabilities, to reflect the credit quality of the parties to the transaction in arriving at fair value. A credit valuation adjustment to a financial asset is required to reflect the default risk of the counterparty. A debit valuation adjustment to a financial liability is recorded to reflect the default risk of HUSI. See "Valuation Techniques - Derivatives" below for additional details. Liquidity risk adjustment - The liquidity risk adjustment (primarily in the form of bid-offer adjustment) reflects the cost that would be incurred to close out the market risks by hedging, disposing or unwinding the position. Valuation models generally produce mid-market values. The bid-offer adjustment is made in such a way that results in a measure that reflects the exit price that most represents the fair value of the financial asset or financial liability under consideration or, where applicable, the fair value of the net market risk exposure of a group of financial assets or financial liabilities. These adjustments relate primarily to Level 2 assets. Model valuation adjustment - Where fair value measurements are determined using an internal valuation model based on observable and unobservable inputs, certain valuation inputs may be less readily determinable. There may be a range of possible valuation inputs that market participants may assume in determining the fair value measurement. The resultant fair value measurement has inherent measurement risk if one or more parameters are unobservable and must be estimated. An input valuation adjustment is necessary to reflect the likelihood that market participants may use different input parameters, and to mitigate the possibility of measurement error. In addition, the values derived from valuation techniques are affected by the choice of valuation model and model limitation. When different valuation techniques are available, the choice of valuation model can be subjective. Furthermore, the valuation model applied may have measurement limitations. In those cases, an additional valuation adjustment is also applied to mitigate the measurement risk. Model valuation adjustments are not material and relate primarily to Level 2 instruments. We apply stress scenarios in determining appropriate liquidity risk and model risk adjustments for Level 3 fair values by reviewing the historical data for unobservable inputs (e.g., correlation, volatility). Some stress scenarios involve at least a 95 percent confidence interval (i.e., two standard deviations). We also utilize unobservable parameter adjustments when instruments are valued using internally developed models which reflects the uncertainty in the value estimates provided by the model. Funding Fair Value Adjustment ("FFVA") - The FFVA reflects the estimated present value of the future market funding cost or benefit associated with funding uncollateralized derivative exposure at rates other than the Overnight Indexed Swap ("OIS") rate. See "Valuation Techniques - Derivatives" below for additional details. Fair Value Hierarchy The Fair Value Framework establishes a three-tiered fair value hierarchy as follows: Level 1 quoted market price - Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities. Level 2 valuation technique using observable inputs - Level 2 inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are inactive, and measurements determined using valuation models where all significant inputs are observable, such as interest rates and yield curves that are observable at commonly quoted intervals. Level 3 valuation technique with significant unobservable inputs - Level 3 inputs are unobservable inputs for the asset or liability and include situations where fair values are measured using valuation techniques based on one or more significant unobservable inputs. Classification within the fair value hierarchy is based on whether the lowest hierarchical level input that is significant to the fair value measurement is observable. As such, the classification within the fair value hierarchy is dynamic and can be transferred to other hierarchy levels in each reporting period. Where fair value measurements are determined based on information obtained from independent pricing services or brokers, Finance applies appropriate validation procedures to substantiate fair value. For price validation purposes, quotations from at least two independent pricing sources are obtained for each financial instrument, where possible. The following factors are considered in determining fair values: • similarities between the asset or the liability under consideration and the asset or liability for which quotation is received; • collaboration of pricing by referencing to other independent market data such as market transactions and relevant benchmark indices; • consistency among different pricing sources; • the valuation approach and the methodologies used by the independent pricing sources in determining fair value; • the elapsed time between the date to which the market data relates and the measurement date; • the source of the fair value information; and • whether the security is traded in an active or inactive market. Greater weight is given to quotations of instruments with recent market transactions, pricing quotes from dealers who stand ready to transact, quotations provided by market-makers who structured such instrument and market consensus pricing based on inputs from a large number of survey participants. Any significant discrepancies among the external quotations are reviewed and adjustments to fair values are recorded where appropriate. Where the transaction volume of a specific instrument has been reduced and the fair value measurement becomes less transparent, Finance will apply more detailed procedures to understand and challenge the appropriateness of the unobservable inputs and the valuation techniques used by the independent pricing service. Where applicable, Finance will develop a fair value estimate using its own pricing model inputs to test reasonableness. Where fair value measurements are determined using internal valuation models, Finance will validate the fair value measurement by either developing unobservable inputs based on the industry consensus pricing surveys in which we participate or back testing by observing the actual settlements occurring soon after the measurement date. Assets and Liabilities Recorded at Fair Value on a Recurring Basis The following table presents information about our assets and liabilities measured at fair value on a recurring basis at March 31, 2020 and December 31, 2019 , and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. Unless otherwise noted below, assets and liabilities in the following table are recorded at fair value through net income (loss). Fair Value Measurements on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Gross Balance Netting (6) Net Balance (in millions) Assets: Trading assets, excluding derivatives: U.S. Treasury, U.S. Government agencies and sponsored enterprises $ 8,207 $ 60 $ — $ 8,267 $ — $ 8,267 Asset-backed securities: Collateralized debt obligations — 67 — 67 — 67 Residential mortgages — — 16 16 — 16 Student loans — 73 — 73 — 73 Corporate and other domestic debt securities — — 465 465 — 465 Debt securities issued by foreign entities 8,803 97 — 8,900 — 8,900 Equity securities 1,432 — — 1,432 — 1,432 Precious metals trading — 4,604 — 4,604 — 4,604 Derivatives: (1) Interest rate contracts 11 19,790 41 19,842 — 19,842 Foreign exchange contracts — 31,123 2 31,125 — 31,125 Equity contracts 1 4,380 225 4,606 — 4,606 Precious metals contracts 1 2,210 — 2,211 — 2,211 Credit contracts — 1,640 351 1,991 — 1,991 Other contracts (2) — — 9 9 — 9 Derivatives netting — — — — (54,277 ) (54,277 ) Total derivatives 13 59,143 628 59,784 (54,277 ) 5,507 Securities available-for-sale: (3) U.S. Treasury, U.S. Government agencies and sponsored enterprises 21,844 14,573 — 36,417 — 36,417 Asset-backed securities: Home equity — 28 — 28 — 28 Other — — 116 116 — 116 Debt securities issued by foreign entities 4,193 38 — 4,231 — 4,231 Loans (4) — 37 — 37 — 37 Loans held for sale (4) — 206 — 206 — 206 Other assets: Equity securities — 147 — 147 — 147 Equity securities measured at net asset value (5) — — — 131 — 131 Total assets $ 44,492 $ 79,073 $ 1,225 $ 124,921 $ (54,277 ) $ 70,644 Liabilities: Domestic deposits (4) $ — $ 5,718 $ 653 $ 6,371 $ — $ 6,371 Trading liabilities, excluding derivatives 429 5 — 434 — 434 Derivatives: (1) Interest rate contracts 11 22,481 — 22,492 — 22,492 Foreign exchange contracts 7 29,732 5 29,744 — 29,744 Equity contracts — 3,909 221 4,130 — 4,130 Precious metals contracts 147 2,040 — 2,187 — 2,187 Credit contracts — 2,075 253 2,328 — 2,328 Other contracts (2) — — 67 67 — 67 Derivatives netting — — — — (57,230 ) (57,230 ) Total derivatives 165 60,237 546 60,948 (57,230 ) 3,718 Long-term debt (4) — 8,004 371 8,375 — 8,375 Total liabilities $ 594 $ 73,964 $ 1,570 $ 76,128 $ (57,230 ) $ 18,898 Fair Value Measurements on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Gross Balance Netting (6) Net Balance (in millions) Assets: Trading assets, excluding derivatives: U.S. Treasury, U.S. Government agencies and sponsored enterprises $ 6,763 $ 38 $ — $ 6,801 $ — $ 6,801 Asset-backed securities: Collateralized debt obligations — 71 — 71 — 71 Residential mortgages — — 17 17 — 17 Student loans — 80 — 80 — 80 Corporate and other domestic debt securities — — 510 510 — 510 Debt securities issued by foreign entities 10,095 221 — 10,316 — 10,316 Equity securities 5,693 — — 5,693 — 5,693 Precious metals trading — 1,909 — 1,909 — 1,909 Derivatives: (1) Interest rate contracts 110 12,275 10 12,395 — 12,395 Foreign exchange contracts 80 16,456 — 16,536 — 16,536 Equity contracts — 4,922 185 5,107 — 5,107 Precious metals contracts 70 1,085 3 1,158 — 1,158 Credit contracts — 1,060 79 1,139 — 1,139 Other contracts (2) — — 10 10 — 10 Derivatives netting — — — — (33,193 ) (33,193 ) Total derivatives 260 35,798 287 36,345 (33,193 ) 3,152 Securities available-for-sale: (3) U.S. Treasury, U.S. Government agencies and sponsored enterprises 17,532 14,702 — 32,234 — 32,234 Asset-backed securities: Home equity — 32 — 32 — 32 Other — — 111 111 — 111 Debt securities issued by foreign entities 3,158 128 — 3,286 — 3,286 Loans held for sale (4) — 178 — 178 — 178 Other assets: Equity securities — 147 — 147 — 147 Equity securities measured at net asset value (5) — — — 136 — 136 Total assets $ 43,501 $ 53,304 $ 925 $ 97,866 $ (33,193 ) $ 64,673 Liabilities: Domestic deposits (4) $ — $ 6,435 $ 774 $ 7,209 $ — $ 7,209 Trading liabilities, excluding derivatives 1,182 124 — 1,306 — 1,306 Derivatives: (1) Interest rate contracts 3 13,570 — 13,573 — 13,573 Foreign exchange contracts — 15,805 1 15,806 — 15,806 Equity contracts — 3,955 113 4,068 — 4,068 Precious metals contracts 80 1,306 3 1,389 — 1,389 Credit contracts — 1,048 20 1,068 — 1,068 Other contracts (2) — — 85 85 — 85 Derivatives netting — — — — (33,900 ) (33,900 ) Total derivatives 83 35,684 222 35,989 (33,900 ) 2,089 Short-term borrowings (4) — 373 — 373 — 373 Long-term debt (4) — 9,993 354 10,347 — 10,347 Total liabilities $ 1,265 $ 52,609 $ 1,350 $ 55,224 $ (33,900 ) $ 21,324 (1) Includes trading derivative assets of $5,393 million and $3,055 million and trading derivative liabilities of $3,489 million and $1,929 million at March 31, 2020 and December 31, 2019 , respectively, as well as derivatives held for hedging and commitments accounted for as derivatives. See Note 9, "Derivative Financial Instruments," for additional information. Excluding changes in fair value of a derivative instrument associated with a qualifying cash flow hedge, which are recognized initially in other comprehensive income, derivative assets and liabilities are recorded at fair value through net income (loss). (2) Consists of swap agreements entered into in conjunction with the sales of Visa Class B Shares. (3) Securities available-for-sale are recorded at fair value through other comprehensive income. Changes in the allowance for credit losses on securities available-for-sale are recorded through net income (loss). (4) See Note 10, "Fair Value Option," for additional information. Excluding the fair value movement on fair value option liabilities attributable to our own credit spread, which is recorded in other comprehensive income, fair value option assets and liabilities are recorded at fair value through net income (loss). (5) Investments that are measured at fair value using the net asset value per share practical expedient have not been classified in the fair value hierarchy. (6) Represents counterparty and cash collateral netting which allow the offsetting of amounts relating to certain contracts if certain conditions are met. Information on Level 3 assets and liabilities The following table summarizes additional information about changes in the fair value of Level 3 assets and liabilities during the three months ended March 31, 2020 and 2019 . As a risk management practice, we may risk manage the Level 3 assets and liabilities, in whole or in part, using securities and derivative positions that are classified as Level 1 or Level 2 measurements within the fair value hierarchy. Since those Level 1 and Level 2 risk management positions are not included in the table below, the information provided does not reflect the effect of such risk management activities related to the Level 3 assets and liabilities. Jan. 1, 2020 Total Realized / Unrealized Gains (Losses) Included in Purch- ases Issu- ances Settle- ments Transfers Into Level 3 Transfers Out of Level 3 Mar. 31, Current Period Unrealized Gains Earnings Other Compre- hensive Income Earnings Other Compre- (in millions) Assets: Trading assets, excluding derivatives: (1) Residential mortgage asset-backed securities $ 17 $ (1 ) $ — $ — $ — $ — $ — $ — $ 16 $ (1 ) $ — Corporate and other domestic debt securities 510 (45 ) — — — — — — 465 (45 ) — Derivatives, net: (2) Interest rate contracts 10 31 — — — — — — 41 31 — Foreign exchange contracts (1 ) (2 ) — — — — — — (3 ) (2 ) — Equity contracts 72 (74 ) — — — 6 — — 4 12 — Credit contracts 59 35 — — — 4 — — 98 35 — Other contracts (3) (75 ) 11 — — — 6 — — (58 ) — — Other asset-backed securities available-for-sale (4) 111 — 5 — — — — — 116 — 5 Total assets $ 703 $ (45 ) $ 5 $ — $ — $ 16 $ — $ — $ 679 $ 30 $ 5 Liabilities: Domestic deposits (5) $ (774 ) $ 1 $ 18 $ — $ (36 ) $ 105 $ — $ 33 $ (653 ) $ — $ 18 Long-term debt (5) (354 ) 5 10 — (101 ) 65 — 4 (371 ) 4 10 Total liabilities $ (1,128 ) $ 6 $ 28 $ — $ (137 ) $ 170 $ — $ 37 $ (1,024 ) $ 4 $ 28 Jan. 1, 2019 Total Realized / Unrealized Gains (Losses) Included in Purch- ases Issu- ances Settle- ments Transfers Into Level 3 Transfers Out of Level 3 Mar. 31, 2019 Current Period Unrealized Gains (Losses) Still Held Included in Earnings Other Compre- hensive Income Earnings Other Compre- hensive Income (in millions) Assets: Trading assets, excluding derivatives: (1) Collateralized debt obligations $ 100 $ 1 $ — $ — $ — $ (11 ) $ — $ — $ 90 $ (6 ) $ — Residential mortgage asset-backed securities 16 — — — — — — — 16 — — Student loan asset-backed securities 92 5 — — — (2 ) — — 95 3 — Corporate and other domestic debt securities 1,803 — — — — (1,293 ) — — 510 — — Derivatives, net: (2) Interest rate contracts 2 5 — — — — — — 7 5 — Foreign exchange contracts (1 ) — — — — — — — (1 ) — — Equity contracts (52 ) 71 — — — 4 — 1 24 75 — Credit contracts 52 (37 ) — — — 38 — — 53 — — Other contracts (3) (35 ) (6 ) — — — 4 — — (37 ) — — Other asset-backed securities available-for-sale (4) 107 — 2 — — — — — 109 — 2 Other assets (6) 4 — — — — — — — 4 — — Total assets $ 2,088 $ 39 $ 2 $ — $ — $ (1,260 ) $ — $ 1 $ 870 $ 77 $ 2 Liabilities: Domestic deposits (5) $ (925 ) $ (29 ) $ (5 ) $ — $ (96 ) $ 45 $ — $ 61 $ (949 ) $ (100 ) $ (5 ) Long-term debt (5) (412 ) (28 ) (3 ) — (31 ) 13 — 8 (453 ) (49 ) (3 ) Total liabilities $ (1,337 ) $ (57 ) $ (8 ) $ — $ (127 ) $ 58 $ — $ 69 $ (1,402 ) $ (149 ) $ (8 ) (1) Gains (losses) on trading assets, excluding derivatives are included in trading revenue in the consolidated statement of income (loss). (2) Level 3 net derivatives included derivative assets of $628 million and derivative liabilities of $546 million at March 31, 2020 and derivative assets of $288 million and derivative liabilities of $242 million at March 31, 2019 . Gains (losses) on derivatives, net are predominantly included in trading revenue and loss on instruments designated at fair value and related derivatives in the consolidated statement of income (loss). (3) Consists of swap agreements entered into in conjunction with the sales of Visa Class B Shares. Gains (losses) on these swap agreements are included in other income (loss) in the consolidated statement of income (loss). (4) Realized gains (losses) on securities available-for-sale are included in other securities gains, net in the consolidated statement of income (loss). Changes in the allowance for credit losses on securities available-for-sale are included in the provision for credit losses in the consolidated statement of income (loss). Unrealized gains (losses) on securities available-for-sale are included in other comprehensive income. (5) Excluding unrealized gains (losses) on fair value option liabilities attributable to our own credit spread, which are recorded in other comprehensive income, gains (losses) on fair value option liabilities are included in loss on instruments designated at fair value and related derivatives in the consolidated statement of income (loss). (6) Represented contingent consideration receivable associated with the sale of a portion of our PB business, which concluded in 2019. Gains (losses) associated with this transaction were included in other income (loss) in the consolidated statement of income (loss). Significant Unobservable Inputs for Recurring Fair Value Measurements The following table presents quantitative information about the unobservable inputs used to determine the recurring fair value measurement of assets and liabilities classified as Level 3 fair value measurements at March 31, 2020 and December 31, 2019 : March 31, 2020 Financial Instrument Type Fair Value (in millions) Valuation Technique(s) Significant Unobservable Inputs Range of Inputs Weighted Average (1) Residential mortgage asset-backed securities $ 16 Broker quotes or consensus pricing and, where applicable, discounted cash flows Prepayment rates 3% N/A Conditional default rates 8% N/A Loss severity rates 70% N/A Discount margin 879bps N/A Corporate and other domestic debt securities $ 465 Discounted cash flows Spread volatility on collateral assets 4% N/A Correlation between insurance claim 80% N/A Interest rate derivative contracts $ 41 Market comparable adjusted for probability to fund and, where applicable, discounted cash flows Probability to fund for rate lock commitments 41% - 100% 72% Likelihood of transaction being executed 90% N/A Foreign exchange derivative contracts (2) $ (3 ) Option pricing model Implied volatility of currency pairs 10% - 17% 13% Equity derivative contracts (2) $ 4 Option pricing model Equity / Equity Index volatility 6% - 81% 35% Equity / Equity and Equity / Index correlation 43% - 78% 50% Equity dividend yields and forward price (7)% - 3% 0% Credit derivative contracts $ 98 Option pricing model and, where applicable, discounted cash flows Credit default swap spreads 200bps N/A Other derivative contracts $ (58 ) Discounted cash flows Conversion rate 1.6 times N/A Expected duration 3 years N/A Other asset-backed securities available-for-sale $ 116 Discounted cash flows Market assumptions related to yields for comparable instruments 4% - 5% 5% Domestic deposits (structured deposits) (2)(3) $ (653 ) Option adjusted discounted cash flows Implied volatility of currency pairs 10% - 17% 13% Equity / Equity Index volatility 7% - 60% 29% Equity / Equity and Equity / Index correlation 43% - 60% 46% Long-term debt (structured notes) (2)(3) $ (371 ) Option adjusted discounted cash flows Implied volatility of currency pairs 10% - 17% 13% Equity / Equity Index volatility 8% - 71% 33% Equity / Equity and Equity / Index correlation 55% - 78% 66% December 31, 2019 Financial Instrument Type Fair Value (in millions) Valuation Technique(s) Significant Unobservable Inputs Range of Inputs Weighted Average (1) Residential mortgage asset-backed securities $ 17 Broker quotes or consensus pricing and, where applicable, discounted cash flows Prepayment rates 1% N/A Conditional default rates 8% N/A Loss severity rates 70% N/A Discount margin 600bps N/A Corporate and other domestic debt securities $ 510 Discounted cash flows Spread volatility on collateral assets 4% N/A Correlation between insurance claim shortfall and collateral value 80% N/A Interest rate derivative contracts $ 10 Market comparable adjusted for probability to fund and, where applicable, discounted cash flows Probability to fund for rate lock commitments 42% - 100% 80% Likelihood of transaction being executed 90% N/A Foreign exchange derivative contracts (2) $ (1 ) Option pricing model Implied volatility of currency pairs 6% - 11% 8% Equity derivative contracts (2) $ 72 Option pricing model Equity / Equity Index volatility 7% - 36% 22% Equity / Equity and Equity / Index correlation 43% - 79% 49% Equity dividend yields 0% - 4% 2% Credit derivative contracts $ 59 Option pricing model and, where applicable, discounted cash flows Credit default swap spreads 41bps N/A Other derivative contracts $ (75 ) Discounted cash flows Conversion rate 1.6 times N/A Expected duration 3 years N/A Other asset-backed securities available-for-sale $ 111 Discounted cash flows Market assumptions related to yields for comparable instruments 0% - 3% 2% Domestic deposits (structured deposits) (2)(3) $ (774 ) Option adjusted discounted cash flows Implied volatility of currency pairs 6% - 11% 8% Equity / Equity Index volatility 7% - 28% 13% Equity / Equity and Equity / Index correlation 43% - 49% 46% Long-term debt (structured notes) (2)(3) $ (354 ) Option adjusted discounted cash flows Implied volatility of currency pairs 6% - 11% 8% Equity / Equity Index volatility 7% - 29% 16% Equity / Equity and Equity / Index correlation 54% - 79% 64% (1) For other asset-backed securities available-for-sale, the value shown is the arithmetic average. For foreign exchange derivatives, equity derivatives, structured deposits and structured notes, weighted averages are calculated based on the fair value of the instruments. For all remaining instrument types, weighted averages are calculated based on the notional value of the instruments. (2) We are the client-facing entity and we enter into identical but opposite derivatives to transfer the resultant risks to our affiliates. With the exception of counterparty credit risks, we are market neutral. The corresponding intra-group derivatives are presented as equity derivatives and foreign exchange derivatives in the table. (3) Structured deposits and structured notes contain embedded derivative features whose fair value measurements contain significant Level 3 inputs. See equity and foreign exchange derivatives below for a discussion of the uncertainty of Level 3 inputs related to structured deposits and structured notes. N/A Not Applicable Uncertainty of Level 3 Inputs to Fair Value Measurements Residential mortgage asset-backed securities - Prepayment rate, probability of default, loss severity rate and discount margin are significant unobservable inputs. • Prepayment rate - The rate at which borrowers pay off the loans early. The prepayment rate is affected by a number of factors including location of the collateral, interest rate type of the loan, borrowers' credit and sensitivity to interest rate movement. • Probability of default - Annualized percentage of default rate over a group of collateral such as residential mortgage loans. • Loss severity rate - The loss severity rate is the percentage of total lifetime losses (both interest and principal) as a percentage of principal balance measured at default date. • Discount margin - An expected return earned in addition to the index underlying (in this case the London Interbank Offered Rate ("LIBOR")) is another input into valuation of securities. A significant increase (decrease) in one or more of these inputs would have resulted in a lower (higher) fair value measurement of the securities. Generally, a change in assumption for default probability would have been accompanied by a directionally similar change in loss severity, and a directionally opposite change in prepayment speed. Corporate and domestic debt securities - The fair value measurement of certain corporate debt securities is affected by the fair value of the underlying portfolios of investments used as collateral and the make-whole guarantee provided by third party guarantors. The probability that the collateral fair value declines below the collateral call threshold concurrent with the guarantors' failure to perform its make whole obligation is unobservable. Generally, an increase (decrease) in the probability the collateral value falls below the collateral call threshold would have been accompanied by a directionally similar change in default probability of the guarantor and would have resulted in a lower (higher) fair value measurement of the securities. Interest rate derivatives - The fair value measurement of certain forward starting interest rate derivatives is affected by the underlying project contingency risk for which probability of execution is not certain (i.e., the interest rate derivative can be canceled if the project fails to execute). For mortgage rate lock commitments, the fair value measurement is affected by the probability of executing and funding the mortgage. An increase (decrease) in the likelihood of a project or mortgage being executed would have resulted in a lower (higher) fair value measurement of the interest rate derivative. Equity and foreign exchange derivatives - The fair value measurement of a structured equity or foreign exchange derivative is primarily affected by the implied volatility of the underlying equity price or exchange rate of the paired foreign currencies. The level of volatility is a function of the nature of the underlying risk, the level of strike price and the years to maturity of the option. Depending on the underlying risk and tenure, we determine the implied volatility based on observable input where information is available. However, substantially all of the implied volatilities are derived based on historical information and are not observable. A significant increase (decrease) in the implied volatility would have resulted in a higher (lower) fair value of a long position in the derivative contract. For a derivative referenced to a basket of variables such as equities or foreign currencies, the fair value measurement is also affected by the correlation of the referenced variables. Correlation measures the relative change in values among two or more variables (i.e., equity or foreign currency pair), which can be positively or negatively correlated. A majority of the correlations are not observable, but are derived based on historical data. A significant increase (decrease) in the correlation of the referenced variables would have resulted in a higher (lower) fair value of a long position in the derivative contract. Credit derivatives - The fair value measurement of certain credit derivatives is primarily affected by the credit spreads of credit default swap contracts insuring asset-backed securities. A significant increase (decrease) in the credit spreads would have resulted in a lower (higher) fair value measurement of the credit derivative. Other derivatives - The fair value of the swap agreements we entered into in conjunction with the sales of Visa Class B Shares is dependent upon the final resolution of the related litigation. Significant unobservable inputs used in the fair value measurement include estimated changes in the conversion rate of Visa Class B Shares into Visa Class A Shares and the expected timing of the final resolution. An increase (decrease) in the loss estimate or in the timing of the resolution of the related litigation would have resulted in a higher (lower) fair value measurement of the derivative. Other asset-backed securities available-for-sale - The fair value measurement of certain asset-backed securities is primarily affected by estimated yields which are determined based on current market yields of comparable instruments adjusted for market liquidity. An increase (decrease) in the yields would have resulted in a decrease (increase) in the fair value measurement of the securities. Significant Transfers Into and Out of Level 3 Measurements During the three months ended March 31, 2020 , we transferred $33 million of domestic deposits and $4 million of long-term debt, which we have elected to carry at fair value, from Level 3 to Level 2 as a result of the embedded derivative no longer being unobservable as the derivative option is closer to maturity and there is more observability in short term volatility. During the three months ended March 31, 2019 , we transferred $61 million of domestic deposits and $8 million of long-term debt, which we have elected to carry at fair value, from Level 3 to Level 2 as a result of the embedded derivative no longer being unobservable as the derivative option is closer in maturity and there is more observability in short term volatility. Assets and Liabilities Recorded at Fair Value on a Non-recurring Basis Certain financial and non-financial assets are measured at fair value on a non-recurring basis and therefore, are not included in the tables above. These assets include (a) loans classified as held for sale reported at the lower of amortized cost or fair value, (b) impaired loans or assets that are written down to fair value based on the valuation of underlying collateral during the period and (c) goodwill, lease ROU assets or leasehold improvement

Litigation and Regulatory Matte

Litigation and Regulatory Matters	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Litigation and Regulatory Matters	Litigation and Regulatory Matters The following supplements, and should be read together with, the disclosure in Note 29, "Litigation and Regulatory Matters," in our 2019 Form 10-K. Only those matters with significant updates and new matters since our disclosure in our 2019 Form 10-K are reported herein. In addition to the matters described below and in our 2019 Form 10-K, in the ordinary course of business, we are routinely named as defendants in, or as parties to, various legal actions and proceedings relating to activities of our current and/or former operations. These legal actions and proceedings may include claims for substantial or indeterminate compensatory or punitive damages, or for injunctive relief. In the ordinary course of business, we also are subject to governmental and regulatory examinations, information-gathering requests, investigations and proceedings (both formal and informal), certain of which may result in adverse judgments, settlements, fines, penalties, injunctions or other relief. In connection with formal and informal inquiries by these regulators, we receive numerous requests, subpoenas and orders seeking documents, testimony and other information in connection with various aspects of our regulated activities. Due to the inherent unpredictability of legal matters, including litigation, governmental and regulatory matters, particularly where the damages sought are substantial or indeterminate or when the proceedings or investigations are in the early stages, we cannot determine with any degree of certainty the timing or ultimate resolution of such matters or the eventual loss, fines, penalties or business impact, if any, that may result. We establish reserves for litigation, governmental and regulatory matters when those matters present loss contingencies that are both probable and can be reasonably estimated. Once established, reserves are adjusted from time to time, as appropriate, in light of additional information. The actual costs of resolving litigation and regulatory matters, however, may be substantially higher than the amounts reserved for those matters. For the legal matters disclosed below, including litigation and governmental and regulatory matters, as well as for the legal matters disclosed in Note 29, "Litigation and Regulatory Matters," in our 2019 Form 10-K, as to which a loss in excess of accrued liability is reasonably possible in future periods and for which there is sufficient currently available information on the basis of which management believes it can make a reliable estimate, we believe a reasonable estimate could be as much as $225 million for HUSI. The legal matters underlying this estimate of possible loss will change from time to time and actual results may differ significantly from this current estimate. In addition, based on the facts currently known for each of the ongoing investigations disclosed in Note 29, "Litigation and Regulatory Matters," in our 2019 Form 10-K, it is not practicable at this time for us to determine the terms on which these ongoing investigations will be resolved or the timing of such resolution. As matters progress, it is possible that any fines and/or penalties could be significant. Given the substantial or indeterminate amounts sought in certain of these matters, and the inherent unpredictability of such matters, an adverse outcome in certain of these matters could have a material adverse effect on our consolidated financial statements in any particular quarterly or annual period. Foreign Exchange ("FX") Matters The Contant v. Bank of America Corporation, et al case has settled. The settlement is subject to court approval. It is possible that additional actions will be initiated against the HSBC entities, including HSBC Bank USA, in relation to their historical foreign exchange activities. Investigations In March 2019, the Competition Appeal Court of South Africa issued a ruling requiring the Competition Commission to refile its complaint and re-opening the question as to whether HSBC Bank USA and certain other financial institutions can be subject to financial penalties. Precious Metals Fix Matters Platinum and Palladium Fix Litigation In March 2020 the court granted the defendants' joint motion to dismiss the third amended complaint but granted plaintiffs leave to replead their Sherman Act and Commodity Exchange Act claims. Plaintiffs may appeal. Benchmark Rate Litigation USD LIBOR: Intercontinental Exchange ("ICE") LIBOR: In March 2020 the court granted the defendants' joint motion to dismiss in its entirety. Plaintiffs may appeal. Mortgage Securitization Trust Litigation The claim brought by Triaxx has settled on a confidential basis . Anti-Terrorism Act Cases Timothy O'Sullivan, et al. v. Deutsche Bank AG, et al. In February 2020, the court denied plaintiffs' motion to amend the complaint following dismissal of the action in March 2019. Plaintiffs may appeal. Based on the facts currently known, in respect of each of the above investigations, it is not practicable at this time for us to determine the terms on which these ongoing investigations will be resolved or the timing of such resolution or for us to estimate reliably the amounts, or range of possible amounts, of any fines and/or penalties. As matters progress, it is possible that any fines and/or penalties could be significant.

New Accounting Pronouncements

New Accounting Pronouncements	3 Months Ended
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements The following new accounting pronouncements were adopted effective January 1, 2020: • Financial Instruments - Credit Losses In June 2016, the Financial Accounting Standards Board ("FASB") issued an Accounting Standards Update ("ASU") that significantly changes measurement of credit losses. The ASU requires recognition of lifetime ECL for loans, securities held-to-maturity, off-balance sheet credit exposures and certain other financial assets reported at amortized cost. In addition, the new guidance requires inclusion of expected recoveries of amounts previously written off, limited to the cumulative amount of prior write-offs, when estimating the allowance for credit losses for in scope financial assets (including collateral-dependent assets). For available-for-sale debt securities where fair value is less than cost, the ASU requires that credit-related impairment, if any, be recognized through an allowance for credit losses and adjusted each period for changes in credit risk. Modeling and economic forecasting requirements of the ASU are new and extensive, and the ASU's requirements differ significantly from the IFRS credit loss reporting that we implemented in 2018 for reporting to HSBC. The ASU also requires expanded disclosures. See Note 4, "Securities," Note 5, "Loans," and Note 6, "Allowance for Credit Losses," for the new disclosures required by this standard, including further discussion of our accounting policies and methodologies used to estimate ECL beginning in 2020. The adoption of this guidance required a cumulative effect adjustment to retained earnings as of January 1, 2020, which resulted in the following impacts: ◦ a decrease in our allowance for credit losses on funded loans of $170 million ; ◦ an increase in our liability for off-balance sheet credit exposures of $54 million ; and ◦ including but not limited to the items above, an increase in retained earnings of $82 million , net of tax. The decrease in our allowance for credit losses on loans was driven by a decrease of approximately $126 million for commercial loans reflecting the impact of their short contractual maturities and the benign credit environment at the time as well as a decrease of approximately $44 million for consumer loans as the impact of their lifetime losses was more than offset by expected recoveries of previous charge-offs of collateral-dependent residential mortgages. The liability for off-balance sheet credit exposures increased reflecting the inclusion of lifetime losses for expected funding over the remaining life of the exposures. The allowance for credit losses established on other financial assets was not material. In accordance with the new guidance, we elected the practical expedients to present accrued interest receivables, net of the allowance for credit losses, in other assets on the consolidated balance sheet and to exclude accrued interest balances from the amortized cost basis for disclosure purposes. In conjunction with our adoption of this guidance, we also elected fair value option on certain student loans held for investment and recorded a separate cumulative effect adjustment to write-up these loans to fair value which resulted in an increase in retained earnings of $2 million , after tax, as of January 1, 2020. The following are accounting pronouncements which will be adopted in future periods: • Reference Rate Reform In March 2020, the FASB issued an ASU that provides temporary optional expedients and exceptions to the U.S. GAAP guidance on contract modifications and hedge accounting to ease the financial reporting burdens associated with transitioning away from LIBOR and other interbank offered rates to acceptable alternative rates. Under the new guidance, an entity can elect by accounting topic or industry subtopic to account for the modification of a contract affected by reference rate reform as a continuation of the existing contract, if certain conditions are met. In addition, the new guidance allows an entity to elect on a hedge-by-hedge basis to continue to apply hedge accounting for hedging relationships in which the critical terms change due to reference rate reform, if certain conditions are met. A one-time election to sell and/or transfer held-to-maturity debt securities that reference a rate affected by reference rate reform is also allowed under the ASU. While the ASU is effective upon issuance, we are currently evaluating which optional expedients and exceptions we will elect to apply. These optional elections generally will cease to apply to contract modifications or existing hedging relationships after December 31, 2022. There have been no additional accounting pronouncements issued that are expected to have or could have a material impact on our consolidated financial statements.

Strategic Initiatives (Tables)

Strategic Initiatives (Tables)	3 Months Ended
	Mar. 31, 2020
Restructuring and Related Activities [Abstract]
Schedule of Changes in Restructuring Liability	The following table summarizes the changes in the liability associated with our Restructuring Plan during the three months ended March 31, 2020: Severance and Other Employee Costs (1) Lease Termination and Associated Costs (2) Total (in millions) Three Months Ended March 31, 2020 Restructuring liability at beginning of period $ — $ — $ — Restructuring costs recorded during the period 9 24 33 Restructuring costs paid during the period — — — Restructuring liability at end of period $ 9 $ 24 $ 33 (1) Severance and other employee costs are included in salaries and employee benefits in the consolidated statement of income (loss), substantially all of which were reported in the Retail Banking & Wealth Management business segment for segment reporting purposes. (2) Primarily includes real estate taxes, service charges and decommissioning costs. Lease termination and associated costs are included in occupancy expense, net in the consolidated statement of income (loss) and were reported in the Corporate Center business segment for segment reporting purposes.

Trading Assets and Liabilities

Trading Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2020
Trading Assets And Liabilities [Abstract]
Trading Assets and Liabilities	Trading assets and liabilities consisted of the following: March 31, 2020 December 31, 2019 (in millions) Trading assets: U.S. Treasury $ 8,207 $ 6,763 U.S. Government agency issued or guaranteed 39 18 U.S. Government sponsored enterprises 21 20 Asset-backed securities 156 168 Corporate and foreign bonds 9,365 10,826 Equity securities 1,432 5,693 Precious metals 4,604 1,909 Derivatives, net 5,393 3,055 Total trading assets $ 29,217 $ 28,452 Trading liabilities: Securities sold, not yet purchased $ 434 $ 1,182 Payables for precious metals — 124 Derivatives, net 3,489 1,929 Total trading liabilities $ 3,923 $ 3,235

Securities (Tables)

Securities (Tables)	3 Months Ended
	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Amortized Cost and Fair Value of the Securities Available-for-Sale and Held-to-Maturity	Our securities available-for-sale and securities held-to-maturity portfolios consisted of the following: March 31, 2020 Amortized Cost Allowance for Credit Losses (1) Unrealized Gains Unrealized Losses Fair Value (in millions) Securities available-for-sale: U.S. Treasury $ 16,893 $ — $ 607 $ (209 ) $ 17,291 U.S. Government sponsored enterprises: Mortgage-backed securities 4,697 — 219 (1 ) 4,915 Collateralized mortgage obligations 262 — 16 (1 ) 277 Direct agency obligations 1,849 — 9 (14 ) 1,844 U.S. Government agency issued or guaranteed: Mortgage-backed securities 10,214 — 276 (2 ) 10,488 Collateralized mortgage obligations 1,282 — 42 (1 ) 1,323 Direct agency obligations 290 — — (11 ) 279 Asset-backed securities collateralized by: Home equity 32 (2 ) — (2 ) 28 Other 116 — 3 (3 ) 116 Foreign debt securities (2) 4,232 — 6 (7 ) 4,231 Total available-for-sale securities $ 39,867 $ (2 ) $ 1,178 $ (251 ) $ 40,792 Securities held-to-maturity: U.S. Government sponsored enterprises: Mortgage-backed securities $ 1,561 $ — $ 53 $ — $ 1,614 Collateralized mortgage obligations 1,289 — 69 — 1,358 U.S. Government agency issued or guaranteed: Mortgage-backed securities 2,805 — 90 — 2,895 Collateralized mortgage obligations 7,316 — 255 (4 ) 7,567 Obligations of U.S. states and political subdivisions 10 (1 ) 1 — 10 Asset-backed securities collateralized by residential mortgages 2 (1 ) 1 — 2 Total held-to-maturity securities $ 12,983 $ (2 ) $ 469 $ (4 ) $ 13,446 December 31, 2019 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in millions) Securities available-for-sale: U.S. Treasury $ 16,219 $ 128 $ (269 ) $ 16,078 U.S. Government sponsored enterprises: Mortgage-backed securities 3,358 57 (13 ) 3,402 Collateralized mortgage obligations 345 3 (1 ) 347 Direct agency obligations 1,382 21 — 1,403 U.S. Government agency issued or guaranteed: Mortgage-backed securities 10,009 29 (41 ) 9,997 Collateralized mortgage obligations 741 10 (4 ) 747 Direct agency obligations 254 6 — 260 Asset-backed securities collateralized by: Home equity 34 — (2 ) 32 Other 108 3 — 111 Foreign debt securities (2) 3,282 4 — 3,286 Total available-for-sale securities $ 35,732 $ 261 $ (330 ) $ 35,663 Securities held-to-maturity: U.S. Government sponsored enterprises: Mortgage-backed securities $ 1,632 $ 22 $ (1 ) $ 1,653 Collateralized mortgage obligations 1,418 40 (4 ) 1,454 U.S. Government agency issued or guaranteed: Mortgage-backed securities 3,004 17 — 3,021 Collateralized mortgage obligations 7,227 85 (22 ) 7,290 Obligations of U.S. states and political subdivisions 10 1 — 11 Asset-backed securities collateralized by residential mortgages 2 — — 2 Total held-to-maturity securities $ 13,293 $ 165 $ (27 ) $ 13,431 (1) As discussed in Note 21, "New Accounting Pronouncements," beginning January 1, 2020, an allowance for credit losses is recognized for debt securities while, prior to January 1, 2020, debt securities were assessed for other-than-temporary impairment. At December 31, 2019 , we did not consider any of our debt securities to be other-than-temporarily impaired (2) Foreign debt securities represent public sector entity, bank or corporate debt.
Gross Unrealized Losses and Related Fair Value	The following table summarizes gross unrealized losses and related fair values for securities available-for-sale by major security type at March 31, 2020 classified as to the length of time the losses have existed: One Year or Less Greater Than One Year March 31, 2020 Number of Securities Gross Unrealized Losses Aggregate Fair Value of Investment Number of Securities Gross Unrealized Losses Aggregate Fair Value of Investment (dollars are in millions) Securities available-for-sale: U.S. Treasury 23 $ (86 ) $ 3,827 16 $ (123 ) $ 1,640 U.S. Government sponsored enterprises 10 (15 ) 910 10 (1 ) 95 U.S. Government agency issued or guaranteed 5 (12 ) 375 7 (2 ) 251 Asset-backed securities 1 (3 ) 59 4 (2 ) 28 Foreign debt securities 24 (7 ) 2,427 5 — 241 Securities available-for-sale 63 $ (123 ) $ 7,598 42 $ (128 ) $ 2,255
Gross Unrealized Losses and Related Fair Value, Previous Guidance	The following table summarizes gross unrealized losses and related fair values at December 31, 2019 classified as to the length of time the losses have existed: One Year or Less Greater Than One Year December 31, 2019 Number of Securities Gross Unrealized Losses Aggregate Fair Value of Investment Number of Securities Gross Unrealized Losses Aggregate Fair Value of Investment (dollars are in millions) Securities available-for-sale: U.S. Treasury 22 $ (61 ) $ 4,034 28 $ (208 ) $ 4,962 U.S. Government sponsored enterprises 18 (8 ) 772 83 (6 ) 672 U.S. Government agency issued or guaranteed 27 (4 ) 1,961 50 (41 ) 2,508 Asset-backed securities — — — 5 (2 ) 33 Foreign debt securities 11 — 1,238 5 — 292 Securities available-for-sale 78 $ (73 ) $ 8,005 171 $ (257 ) $ 8,467 Securities held-to-maturity: U.S. Government sponsored enterprises 15 $ — $ 63 76 $ (5 ) $ 522 U.S. Government agency issued or guaranteed 46 (3 ) 887 274 (19 ) 1,705 Obligations of U.S. states and political subdivisions 1 — — 1 — — Securities held-to-maturity 62 $ (3 ) $ 950 351 $ (24 ) $ 2,227
Credit risk Profile of Held-to-Maturity Securities	The following table shows the credit risk profile of our securities held-to-maturity portfolio: At March 31, 2020 Investment Grade Non-Investment Grade Total (in millions) U.S. Government sponsored enterprises $ 2,850 $ — $ 2,850 U.S. Government agency issued or guaranteed 10,121 — 10,121 Obligations of U.S. states and political subdivisions 10 — 10 Asset-backed securities collateralized by residential mortgages 2 — 2 Total securities held-to-maturity $ 12,983 $ — $ 12,983
Realized Gains and Losses on Investment Securities Transactions Attributable to Available-for-Sale Securities	The following table summarizes realized gains and losses on investment securities transactions attributable to available-for-sale securities: Three Months Ended March 31, 2020 2019 (in millions) Gross realized gains $ 51 $ 16 Gross realized losses (23 ) (9 ) Net realized gains $ 28 $ 7
Distribution of Maturities of Debt Securities with the Approximate Yield of the Portfolio	The table below also reflects the distribution of maturities of debt securities held at March 31, 2020 , together with the approximate yield of the portfolio. The yields shown are calculated by dividing annualized interest income, including the accretion of discounts and the amortization of premiums, by the amortized cost of securities outstanding at March 31, 2020 . Within One Year After One But Within Five Years After Five But Within Ten Years After Ten Years Amount Yield Amount Yield Amount Yield Amount Yield (dollars are in millions) Available-for-sale: U.S. Treasury $ 55 2.93 % $ 5,308 1.27 % $ 6,201 1.61 % $ 5,329 2.10 % U.S. Government sponsored enterprises 730 2.82 516 1.90 2,426 2.66 3,136 2.55 U.S. Government agency issued or guaranteed — — 80 2.12 1 7.88 11,705 2.03 Asset-backed securities — — — — 62 4.85 86 3.19 Foreign debt securities 2,242 .56 1,990 1.52 — — — — Total amortized cost $ 3,027 1.15 % $ 7,894 1.39 % $ 8,690 1.93 % $ 20,256 2.14 % Total fair value $ 3,031 $ 7,997 $ 9,176 $ 20,588 Held-to-maturity: U.S. Government sponsored enterprises $ — — % $ 480 2.66 % $ 568 2.26 % $ 1,802 3.19 % U.S. Government agency issued or guaranteed — — 12 3.92 20 4.18 10,089 2.57 Obligations of U.S. states and political subdivisions — — 6 3.58 4 4.16 — — Asset-backed securities — — — — — — 2 6.02 Total amortized cost $ — — % $ 498 2.70 % $ 592 2.34 % $ 11,893 2.67 % Total fair value $ — $ 512 $ 607 $ 12,327
Equity Securities Not Classified as Trading	Equity securities that are not classified as trading and are included in other assets consisted of the following: March 31, 2020 December 31, 2019 (in millions) Equity securities carried at fair value $ 278 $ 283 Equity securities without readily determinable fair values 12 12

Loans (Tables)

Loans (Tables)	3 Months Ended
	Mar. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Components of Loans	Loans consisted of the following: March 31, 2020 December 31, 2019 (in millions) Commercial loans: Real estate, including construction $ 11,369 $ 11,501 Business and corporate banking 19,620 13,479 Global banking (1) 24,141 17,915 Other commercial: Affiliates (2) 3,087 2,343 Other 3,029 2,973 Total other commercial 6,116 5,316 Total commercial 61,246 48,211 Consumer loans: Residential mortgages 18,034 17,801 Home equity mortgages 814 853 Credit cards 1,300 1,405 Other consumer (3) 334 283 Total consumer 20,482 20,342 Total loans $ 81,728 $ 68,553 (1) Represents large multinational firms including globally focused U.S. corporate and financial institutions, U.S. dollar lending to multinational banking clients managed by HSBC on a global basis and complex large business clients supported by Global Banking and Markets relationship managers. (2) See Note 14, "Related Party Transactions," for additional information regarding loans to HSBC affiliates. (3) Includes certain student loans that we have elected to designate under the fair value option and are therefore carried at fair value, which totaled $37 million at March 31, 2020 . See Note 10, "Fair Value Option," for further details.
Summary of Past Due Status of Loans	The following table summarizes the past due status of our loans at March 31, 2020 and December 31, 2019 . The aging of past due amounts is determined based on the contractual delinquency status of payments under the loan. An account is generally considered to be contractually delinquent when payments have not been made in accordance with the loan terms. Delinquency status is affected by customer account management policies and practices such as re-age, which results in the re-setting of the contractual delinquency status to current. Past Due Total Past Due 30 Days or More At March 31, 2020 30 - 89 Days 90+ Days Current (1) Total Loans (in millions) Commercial loans: Real estate, including construction $ 4 $ 2 $ 6 $ 11,363 $ 11,369 Business and corporate banking 104 8 112 19,508 19,620 Global banking — — — 24,141 24,141 Other commercial 32 — 32 6,084 6,116 Total commercial 140 10 150 61,096 61,246 Consumer loans: Residential mortgages 366 259 625 17,409 18,034 Home equity mortgages 10 23 33 781 814 Credit cards 25 28 53 1,247 1,300 Other consumer 7 5 12 322 334 Total consumer 408 315 723 19,759 20,482 Total loans $ 548 $ 325 $ 873 $ 80,855 $ 81,728 Past Due Total Past Due 30 Days or More At December 31, 2019 30 - 89 Days 90+ Days Current (1) Total Loans (in millions) Commercial loans: Real estate, including construction $ 7 $ 1 $ 8 $ 11,493 $ 11,501 Business and corporate banking 60 35 95 13,384 13,479 Global banking — — — 17,915 17,915 Other commercial 22 — 22 5,294 5,316 Total commercial 89 36 125 48,086 48,211 Consumer loans: Residential mortgages 342 272 614 17,187 17,801 Home equity mortgages 10 24 34 819 853 Credit cards 24 24 48 1,357 1,405 Other consumer 5 5 10 273 283 Total consumer 381 325 706 19,636 20,342 Total loans $ 470 $ 361 $ 831 $ 67,722 $ 68,553 (1) Loans less than 30 days past due are presented as current.
Summary of Nonaccrual Loans and Accruing Receivables 90 Days or More Delinquent	Nonperforming loans, including nonaccrual loans and accruing loans contractually 90 days or more past due, consisted of the following: Nonaccrual Loans Accruing Loans Contractually Past Due 90 Days or More Nonaccrual Loans With No Allowance For Credit Losses (in millions) At March 31, 2020 Commercial: Real estate, including construction $ 5 $ — $ 3 Business and corporate banking 112 2 2 Global banking 138 — 127 Total commercial 255 2 132 Consumer: Residential mortgages (1)(2)(3) 370 — 171 Home equity mortgages (1)(2) 38 — 31 Credit cards — 28 — Other consumer — 2 — Total consumer 408 30 202 Total nonperforming loans $ 663 $ 32 $ 334 At December 31, 2019 Commercial: Real estate, including construction $ 6 $ — $ 3 Business and corporate banking 82 1 19 Global banking 149 — 117 Total commercial 237 1 139 Consumer: Residential mortgages (1)(2)(3) 381 — 257 Home equity mortgages (1)(2) 46 — 32 Credit cards — 24 — Other consumer — 5 — Total consumer 427 29 289 Total nonperforming loans $ 664 $ 30 $ 428 (1) At March 31, 2020 and December 31, 2019 , nonaccrual consumer mortgage loans include $286 million and $289 million , respectively, of loans that are carried at the lower of amortized cost or fair value of the collateral less cost to sell. The decrease in nonaccrual consumer mortgage loans with no allowance for credit losses at March 31, 2020 reflects the impact of adopting new accounting guidance which requires expected recoveries related to subsequent increases in the fair value of collateral for collateral-dependent loans to be recognized in the allowance for credit losses beginning January 1, 2020. See Note 21, "New Accounting Pronouncements," for additional discussion. (2) Nonaccrual consumer mortgage loans include all loans which are 90 or more days contractually delinquent as well as loans discharged under Chapter 7 bankruptcy and not re-affirmed and second lien loans where the first lien loan that we own or service is 90 or more days contractually delinquent. (3) Nonaccrual consumer mortgage loans for all periods does not include guaranteed loans purchased from the Government National Mortgage Association. Repayment of these loans is predominantly insured by the Federal Housing Administration and as such, these loans have different risk characteristics from the rest of our consumer loan portfolio.
Schedule of Additional Information on Nonaccrual Loans	The following table provides additional information on our nonaccrual loans: Three Months Ended March 31, 2020 2019 (in millions) Interest income that would have been recorded if the nonaccrual loans had been current in accordance with contractual terms during the period $ 8 $ 9 Interest income that was recorded on nonaccrual loans and included in interest income during the period 7 3
Summary of TDR Loans	The following table summarizes our TDR Loans at March 31, 2020 and December 31, 2019 : March 31, 2020 December 31, 2019 (in millions) Commercial loans: Business and corporate banking $ 32 $ 36 Global banking 69 68 Total commercial (1) 101 104 Consumer loans: Residential mortgages (2) 561 580 Home equity mortgages (2) 32 32 Credit cards 4 4 Total consumer 597 616 Total TDR Loans (3) $ 698 $ 720 (1) Additional commitments to lend to commercial borrowers whose loans have been modified in TDR Loans totaled $143 million and $222 million at March 31, 2020 and December 31, 2019 , respectively. (2) At March 31, 2020 and December 31, 2019 , the carrying value of consumer mortgage TDR Loans includes $508 million and $557 million , respectively, of loans that are recorded at the lower of amortized cost or fair value of the collateral less cost to sell. (3) At March 31, 2020 and December 31, 2019 , the carrying value of TDR Loans includes $318 million and $230 million , respectively, of loans which are classified as nonaccrual.
Summary of Receivables which were Modified and as a Result became Classified as TDR Loans	The following table presents information about loans which were modified during the three months ended March 31, 2020 and 2019 and as a result of this action became classified as TDR Loans: Three Months Ended March 31, 2020 2019 (in millions) Commercial loans: Global banking $ 12 $ — Total commercial 12 — Consumer loans: Residential mortgages 4 1 Home equity mortgages 1 — Credit cards 1 1 Total consumer 6 2 Total $ 18 $ 2
Loans Classified as TDR Loans in Previous 12 Months that became 60 Days or Greater Delinquent	The following table presents consumer loans which were classified as TDR Loans during the previous 12 months which subsequently became 60 days or greater contractually delinquent during the three months ended March 31, 2020 and 2019 : Three Months Ended March 31, 2020 2019 (in millions) Consumer loans: Residential mortgages $ 1 $ 2 Total consumer $ 1 $ 2
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Summary of Criticized Commercial Loans	The following table summarizes our criticized commercial loans, including a disaggregation of the loans by year of origination as of March 31, 2020 : 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total at Mar. 31, 2020 Total at Dec. 31, 2019 (in millions) Real estate, including construction: Special mention $ — $ 402 $ 150 $ 122 $ — $ 234 $ — $ — $ 908 $ 516 Substandard — 130 7 — — 45 — — 182 203 Doubtful — — — — — — — — — — Total real estate, including construction — 532 157 122 — 279 — — 1,090 719 Business and corporate banking: Special mention — 25 21 50 13 164 555 24 852 467 Substandard — 29 24 24 2 121 367 2 569 386 Doubtful — 16 13 — — 18 64 2 113 23 Total business and corporate banking — 70 58 74 15 303 986 28 1,534 876 Global banking: Special mention — 38 — — — 102 334 — 474 184 Substandard — — — — — 86 270 — 356 196 Doubtful — — — — — 13 — — 13 15 Total global banking — 38 — — — 201 604 — 843 395 Other commercial: Special mention — 24 11 — 3 20 — — 58 11 Substandard — — — — — — 61 — 61 — Doubtful — — — — — — — — — — Total other commercial — 24 11 — 3 20 61 — 119 11 Total commercial: Special mention — 489 182 172 16 520 889 24 2,292 1,178 Substandard — 159 31 24 2 252 698 2 1,168 785 Doubtful — 16 13 — — 31 64 2 126 38 Total commercial $ — $ 664 $ 226 $ 196 $ 18 $ 803 $ 1,651 $ 28 $ 3,586 $ 2,001
Summary of Credit Quality Indicators	Commercial loans are assigned a credit rating based on the estimated probability of default. Investment grade includes loans with credit ratings of at least BBB- or above or the equivalent based on our internal credit rating system. The following table shows the credit risk profile of our commercial loan portfolio, including a disaggregation of the loans by year of origination as of March 31, 2020 : 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total at Mar. 31, 2020 Total at Dec. 31, 2019 (in millions) Real estate, including construction: Investment grade $ 287 $ 1,392 $ 1,500 $ 515 $ 202 $ 1,205 $ 6 $ 4 $ 5,111 $ 6,332 Non-investment grade 118 2,408 1,595 874 134 966 141 22 6,258 5,169 Total real estate, including construction 405 3,800 3,095 1,389 336 2,171 147 26 11,369 11,501 Business and corporate banking: Investment grade 459 611 202 104 389 1,744 5,219 87 8,815 6,029 Non-investment grade 160 914 651 311 151 1,700 6,657 261 10,805 7,450 Total business and corporate banking 619 1,525 853 415 540 3,444 11,876 348 19,620 13,479 Global banking: Investment grade 319 1,363 1,013 802 141 3,299 10,386 — 17,323 12,981 Non-investment grade 59 469 488 40 442 1,138 4,182 — 6,818 4,934 Total global banking 378 1,832 1,501 842 583 4,437 14,568 — 24,141 17,915 Other commercial: Investment grade 76 431 247 163 96 300 4,217 — 5,530 4,649 Non-investment grade 61 46 88 22 52 84 233 — 586 667 Total other commercial 137 477 335 185 148 384 4,450 — 6,116 5,316 Total commercial: Investment grade 1,141 3,797 2,962 1,584 828 6,548 19,828 91 36,779 29,991 Non-investment grade 398 3,837 2,822 1,247 779 3,888 11,213 283 24,467 18,220 Total commercial $ 1,539 $ 7,634 $ 5,784 $ 2,831 $ 1,607 $ 10,436 $ 31,041 $ 374 $ 61,246 $ 48,211
Summary of Nonperforming Status	The following table summarizes the nonperforming status of our commercial loan portfolio, including a disaggregation of the loans by year of origination as of March 31, 2020 : 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total at Mar. 31, 2020 Total at Dec. 31, 2019 (in millions) Real estate, including construction: Performing loans $ 405 $ 3,800 $ 3,095 $ 1,389 $ 335 $ 2,169 $ 147 $ 24 $ 11,364 $ 11,495 Nonaccrual loans — — — 1 2 — 2 5 6 Accruing loans contractually past due 90 days or more — — — — — — — — — — Total real estate, including construction 405 3,800 3,095 1,389 336 2,171 147 26 11,369 11,501 Business and corporate banking: Performing loans 619 1,509 840 415 540 3,428 11,808 347 19,506 13,396 Nonaccrual loans — 16 13 — — 16 66 1 112 82 Accruing loans contractually past — — — — — — 2 — 2 1 Total business and corporate banking 619 1,525 853 415 540 3,444 11,876 348 19,620 13,479 Global banking: Performing loans 378 1,832 1,501 842 564 4,386 14,500 — 24,003 17,766 Nonaccrual loans — — — — 19 51 68 — 138 149 Accruing loans contractually past due 90 days or more — — — — — — — — — — Total global banking 378 1,832 1,501 842 583 4,437 14,568 — 24,141 17,915 Other commercial: Performing loans 137 477 335 185 148 384 4,450 — 6,116 5,316 Nonaccrual loans — — — — — — — — — — Accruing loans contractually past due 90 days or more — — — — — — — — — — Total other commercial 137 477 335 185 148 384 4,450 — 6,116 5,316 Total commercial: Performing loans 1,539 7,618 5,771 2,831 1,587 10,367 30,905 371 60,989 47,973 Nonaccrual loans — 16 13 — 20 69 134 3 255 237 Accruing loans contractually past due 90 days or more — — — — — — 2 — 2 1 Total commercial $ 1,539 $ 7,634 $ 5,784 $ 2,831 $ 1,607 $ 10,436 $ 31,041 $ 374 $ 61,246 $ 48,211
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Summary of TDR Loans	The following table summarizes TDR Loans in our consumer loan portfolio, including a disaggregation of the loans by year of origination as of March 31, 2020 : 2020 2019 2018 2017 2016 Prior Revolving Loans Total at Mar. 31, 2020 Total at Dec. 31, 2019 (in millions) Residential mortgages $ — $ — $ — $ — $ 1 $ 560 $ — $ 561 $ 580 Home equity mortgages — — — — — 32 — 32 32 Credit cards — — — — — — 4 4 4 Total consumer $ — $ — $ — $ — $ 1 $ 592 $ 4 $ 597 $ 616
Summary of Credit Quality Indicators	The following table summarizes dollars of two-months-and-over contractual delinquency for our consumer loan portfolio, including a disaggregation of the loans by year of origination as of March 31, 2020 : 2020 2019 2018 2017 2016 Prior Revolving Loans Total at Mar. 31, 2020 Total at Dec. 31, 2019 (in millions) Residential mortgages (1)(2) $ — $ 11 $ 10 $ 15 $ 13 $ 315 $ — $ 364 $ 350 Home equity mortgages (1)(2) — — — — — 26 — 26 25 Credit cards — — — — — — 39 39 34 Other consumer — 1 — — — 4 2 7 7 Total consumer $ — $ 12 $ 10 $ 15 $ 13 $ 345 $ 41 $ 436 $ 416 (1) At March 31, 2020 and December 31, 2019 , consumer mortgage loan delinquency includes $249 million and $256 million , respectively, of loans that are carried at the lower of amortized cost or fair value of the collateral less cost to sell. (2) At March 31, 2020 and December 31, 2019 , consumer mortgage loans include $135 million and $142 million , respectively, of loans that were in the process of foreclosure.
Summary of Nonperforming Status	The following table summarizes the nonperforming status of our consumer loan portfolio, including a disaggregation of the loans by year of origination as of March 31, 2020 : 2020 2019 2018 2017 2016 Prior Revolving Loans Total at Mar. 31, 2020 Total at Dec. 31, 2019 (in millions) Residential mortgages: Performing loans $ 1,032 $ 2,968 $ 1,799 $ 2,049 $ 2,359 $ 7,457 $ — $ 17,664 $ 17,420 Nonaccrual loans — 8 6 13 12 331 — 370 381 Total residential mortgages 1,032 2,976 1,805 2,062 2,371 7,788 — 18,034 17,801 Home equity mortgages: Performing loans 14 54 44 41 53 570 — 776 807 Nonaccrual loans — — — — — 38 — 38 46 Total home equity mortgages 14 54 44 41 53 608 — 814 853 Credit cards: Performing loans — — — — — — 1,272 1,272 1,381 Accruing loans contractually past due 90 days or more — — — — — — 28 28 24 Total credit cards — — — — — — 1,300 1,300 1,405 Other consumer: Performing loans 41 63 1 2 4 125 96 332 278 Accruing loans contractually past due 90 days or more — — — — — — 2 2 5 Total other consumer 41 63 1 2 4 125 98 334 283 Total consumer: Performing loans 1,087 3,085 1,844 2,092 2,416 8,152 1,368 20,044 19,886 Nonaccrual loans — 8 6 13 12 369 — 408 427 Accruing loans contractually past due 90 days or more — — — — — — 30 30 29 Total consumer $ 1,087 $ 3,093 $ 1,850 $ 2,105 $ 2,428 $ 8,521 $ 1,398 $ 20,482 $ 20,342

Allowance for Credit Losses (Ta

Allowance for Credit Losses (Tables)	3 Months Ended
	Mar. 31, 2020
Credit Loss [Abstract]
Summary of Allowance for Credit Losses and Liability for Off-balance Sheet Credit Exposures	The following table summarizes our allowance for credit losses and the liability for off-balance sheet credit exposures: March 31, 2020 January 1, 2020 December 31, 2019 (in millions) Allowance for credit losses: Loans $ 931 $ 467 $ 637 Securities held-to-maturity (1) 2 2 — Other financial assets measured at amortized cost (2) 5 3 — Securities available-for-sale (1) 2 3 — Total allowance for credit losses $ 940 $ 475 $ 637 Liability for off-balance sheet credit exposures $ 371 $ 158 $ 104 (1) See Note 4, "Securities," for additional information regarding the allowance for credit losses associated with our security portfolios. (2) Primarily includes accrued interest receivables and customer acceptances.
Summary of Changes in the Allowance for Credit Losses and the Related Loan Balance by Product	The following table summarizes the changes in the allowance for credit losses on loans by product or line of business during the three months ended March 31, 2020 and 2019 : Commercial Loans Consumer Loans Real Estate, including Construction Business Global Other Residential Home Credit Other Total Loans (in millions) Three Months Ended March 31, 2020 Allowance for credit losses – beginning of period $ 153 $ 239 $ 106 $ 9 $ 12 $ 6 $ 105 $ 7 $ 637 Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses (112 ) (60 ) 51 (5 ) (86 ) 7 32 3 (170 ) Allowance for credit losses – beginning of period, adjusted 41 179 157 4 (74 ) 13 137 10 467 Provision charged (credited) to income 51 213 110 1 30 3 95 9 512 Charge-offs — (12 ) (19 ) — 1 (2 ) (22 ) (2 ) (56 ) Recoveries — 2 — — 2 2 2 — 8 Net (charge-offs) recoveries — (10 ) (19 ) — 3 — (20 ) (2 ) (48 ) Allowance for credit losses – end of period $ 92 $ 382 $ 248 $ 5 $ (41 ) $ 16 $ 212 $ 17 $ 931 Three Months Ended March 31, 2019 Allowance for credit losses – beginning of period $ 116 $ 219 $ 108 $ 15 $ 13 $ 7 $ 58 $ 5 $ 541 Provision charged (credited) to income 3 22 14 — (1 ) 1 16 3 58 Charge-offs — (2 ) — — (4 ) (1 ) (13 ) (1 ) (21 ) Recoveries — — — — 2 1 2 — 5 Net (charge-offs) recoveries — (2 ) — — (2 ) — (11 ) (1 ) (16 ) Allowance for credit losses – end of period $ 119 $ 239 $ 122 $ 15 $ 10 $ 8 $ 63 $ 7 $ 583
Summary of Changes in the Liability for Off-balance Sheet Credit Exposures	The following table summarizes the changes in the liability for off-balance sheet credit exposures during the three months ended March 31, 2020 and 2019 : Three Months Ended March 31, 2020 2019 (in millions) Balance at beginning of period $ 104 $ 96 Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses 54 — Balance at beginning of period, adjusted 158 96 Provision charged (credited) to income 213 (7 ) Balance at end of period $ 371 $ 89
Summary of Accrued Interest Receivables	The following table summarizes accrued interest receivables associated with financial assets carried at amortized cost and securities available-for-sale along with the related allowance for credit losses, which are reported net in other assets on the consolidated balance sheet. These accrued interest receivables are excluded from the amortized cost basis disclosures presented elsewhere in these financial statements, including Note 4, "Securities," and Note 5, "Loans." March 31, 2020 (in millions) Accrued interest receivables: Loans $ 177 Securities held-to-maturity 32 Other financial assets measured at amortized cost 3 Securities available-for-sale 109 Total accrued interest receivables 321 Allowance for credit losses 3 Accrued interest receivables, net $ 318

Loans Held for Sale (Tables)

Loans Held for Sale (Tables)	3 Months Ended
	Mar. 31, 2020
Receivables [Abstract]
Loans Held for Sale	Loans held for sale consisted of the following: March 31, 2020 December 31, 2019 (in millions) Commercial loans: Real estate, including construction $ — $ 83 Business and corporate banking — 35 Global banking 234 94 Total commercial 234 212 Consumer loans: Residential mortgages 51 77 Total consumer 51 77 Total loans held for sale $ 285 $ 289

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	The following table presents the fair value of derivative contracts by major product type on a gross basis. Gross fair values exclude the effects of both counterparty netting as well as collateral, and therefore are not representative of our exposure. The table below also presents the amounts of counterparty netting and cash collateral that have been offset in the consolidated balance sheet, as well as cash and securities collateral posted and received under enforceable master netting agreements that do not meet the criteria for netting. Derivative assets and liabilities which are not subject to an enforceable master netting agreement, or are subject to a netting agreement where an appropriate legal opinion to determine such agreements are enforceable has not been either sought or obtained, have not been netted in the following table. Where we have received or posted collateral under netting agreements where an appropriate legal opinion to determine such agreements are enforceable has not been either sought or obtained, the related collateral also has not been netted in the following table. March 31, 2020 December 31, 2019 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities (in millions) Derivatives accounted for as fair value hedges (1) OTC-cleared (2) $ — $ 2 $ — $ 1 Bilateral OTC (2) — 291 — 164 Interest rate contracts — 293 — 165 Derivatives accounted for as cash flow hedges (1) Foreign exchange contracts - bilateral OTC (2) 12 8 16 20 Interest rate contracts - bilateral OTC (2) — 2 — 1 Total derivatives accounted for as hedges 12 303 16 186 Trading derivatives not accounted for as hedges (3) Exchange-traded (2) 11 11 110 3 OTC-cleared (2) 126 17 167 29 Bilateral OTC (2) 19,494 22,164 11,990 13,324 Interest rate contracts 19,631 22,192 12,267 13,356 Exchange-traded (2) — 7 80 — OTC-cleared (2) 41 — — — Bilateral OTC (2) 31,072 29,727 16,440 15,786 Foreign exchange contracts 31,113 29,734 16,520 15,786 Exchange-traded (2) 1 — — — Bilateral OTC (2) 4,182 3,201 3,753 3,993 Equity contracts 4,183 3,201 3,753 3,993 Exchange-traded (2) — 147 71 80 Bilateral OTC (2) 2,211 2,040 1,087 1,309 Precious metals contracts 2,211 2,187 1,158 1,389 OTC-cleared (2) 85 — 1 — Bilateral OTC (2) 1,876 2,307 1,138 1,024 Credit contracts 1,961 2,307 1,139 1,024 Other non-qualifying derivatives not accounted for as hedges (1) Interest rate contracts - bilateral OTC (2) 211 5 128 51 Foreign exchange contracts - bilateral OTC (2) — 2 — — Equity contracts - bilateral OTC (2) 423 929 1,354 75 Credit contracts - bilateral OTC (2) 30 21 — 44 Other contracts - bilateral OTC (2)(4) 9 67 10 85 Total derivatives 59,784 60,948 36,345 35,989 Less: Gross amounts of receivable / payable subject to enforceable master netting agreements (5)(7) 48,099 48,099 29,510 29,510 Less: Gross amounts of cash collateral received / posted subject to enforceable master netting agreements (6)(7) 6,178 9,131 3,683 4,390 Net amounts of derivative assets / liabilities presented in the balance sheet 5,507 3,718 3,152 2,089 Less: Gross amounts of financial instrument collateral received / posted subject to enforceable master netting agreements but not offset in the consolidated balance sheet 1,443 552 891 553 Net amounts of derivative assets / liabilities $ 4,064 $ 3,166 $ 2,261 $ 1,536 (1) Derivative assets / liabilities related to cash flow hedges, fair value hedges and derivative instruments held for purposes other than for trading are recorded in other assets / interest, taxes and other liabilities on the consolidated balance sheet. (2) Over-the-counter ("OTC") derivatives include derivatives executed and settled bilaterally with counterparties without the use of an organized exchange or central clearing house. The credit risk associated with bilateral OTC derivatives is managed through obtaining collateral and enforceable master netting agreements. OTC-cleared derivatives are executed bilaterally in the OTC market but then novated to a central clearing counterparty, whereby the central clearing counterparty becomes the counterparty to each of the original counterparties. Exchange traded derivatives are executed directly on an organized exchange. Credit risk is minimized for OTC-cleared derivatives and exchange traded derivatives through daily margining requirements. In addition, OTC-cleared interest rate and credit derivatives with certain central clearing counterparties are settled daily. (3) Trading related derivative assets / liabilities are recorded in trading assets / trading liabilities on the consolidated balance sheet. (4) Consists of swap agreements entered into in conjunction with the sales of Visa Inc. ("Visa") Class B common shares ("Class B Shares"). (5) Represents the netting of derivative receivable and payable balances for the same counterparty under enforceable netting agreements. (6) Represents the netting of cash collateral posted and received by counterparty under enforceable netting agreements. (7) Netting is performed at a counterparty level in cases where enforceable master netting agreements are in place, regardless of the type of derivative instrument. Therefore, we have not allocated netting to the different types of derivative instruments shown in the table above.
Schedule of Gains and Losses on Fair Value Hedging Instruments	The following table presents the carrying amount of hedged items in fair value hedges recognized in the consolidated balance sheet at March 31, 2020 and December 31, 2019 , along with the cumulative amount of fair value hedging adjustments included in the carrying amount of those hedged items: Carrying Amount of Hedged Items (1) Cumulative Amount of Fair Value Hedging Adjustments Increasing (Decreasing) the Carrying Amount of Hedged Items Active Discontinued Total (in millions) At March 31, 2020 Securities available-for-sale ("AFS") $ 10,928 $ 1,630 $ 356 $ 1,986 Deposits (2) 3,229 229 — 229 Long-term debt 5,927 326 (22 ) 304 At December 31, 2019 Securities available-for-sale ("AFS") 7,277 554 428 982 Long-term debt 10,975 285 (32 ) 253 (1) The carrying amount of securities AFS represents the amortized cost basis. (2) During the first quarter of 2020, $3.0 billion of fixed-rate senior debt obligations issued to HSBC North America were recharacterized as time deposits. The cumulative amount of fair value hedging adjustments associated with this debt was reclassified to deposits. See Note 14, "Related Party Transactions," for additional information. The following table presents information on gains and losses on derivative instruments designated and qualifying as hedging instruments and the hedged items in fair value hedges and their locations on the consolidated statement of income (loss): Location of Gain (Loss) Gain (Loss) on Derivatives Gain (Loss) on Hedged Items (in millions) Three Months Ended March 31, 2020 Interest rate contracts / Securities AFS Net interest income $ (1,156 ) $ 1,178 Interest rate contracts / Deposits Net interest income 120 (146 ) Interest rate contracts / Long-term debt Net interest income 177 (229 ) Total $ (859 ) $ 803 Three Months Ended March 31, 2019 Interest rate contracts / Securities AFS Net interest income $ (257 ) $ 350 Interest rate contracts / Long-term debt Net interest income 84 (199 ) Total $ (173 ) $ 151
Schedule of Gains and Losses on Cash Flow Hedging Instruments	The following table presents information on gains and losses on derivative instruments designated and qualifying as hedging instruments in cash flow hedges (including amounts recognized in AOCI from discontinued cash flow hedges) and their locations on the consolidated statement of income (loss): Gain (Loss) Recognized in AOCI on Derivatives Location of Gain (Loss) Reclassified from AOCI into Income Gain (Loss) Reclassified From AOCI into Income 2020 2019 2020 2019 (in millions) Three Months Ended March 31, Foreign exchange contracts $ — $ 1 Net interest income $ — $ — Interest rate contracts 113 7 Net interest income (6 ) (10 ) Total $ 113 $ 8 $ (6 ) $ (10 )
Schedule of Gains and Losses on Derivative Instruments Included in Trading Activities	The following table presents information on gains and losses on derivative instruments held for trading purposes and their locations on the consolidated statement of income (loss): Location of Gain (Loss) Recognized in Income on Derivatives Gain (Loss) Recognized in Income on Derivatives Three Months Ended March 31, 2020 2019 (in millions) Interest rate contracts Trading revenue $ 17 $ 56 Foreign exchange contracts (1) Trading revenue (665 ) (14 ) Equity contracts Trading revenue 1,257 (89 ) Precious metals contracts (1) Trading revenue 160 17 Credit contracts Trading revenue (657 ) (122 ) Total $ 112 $ (152 ) (1) During the third quarter of 2019, we changed our presentation for certain derivatives that were previously reported in foreign exchange contracts and began reporting these derivatives in precious metals contracts. As a result, we have reclassified $151 million of gains from foreign exchange contracts to precious metals contracts during the three months ended March 31, 2019 to conform with the current year presentation.
Schedule of Gains and Losses on Derivative Instruments Held for Non-qualifying Hedging Activities	The following table presents information on gains and losses on derivative instruments held for non-qualifying hedging and other activities and their locations on the consolidated statement of income (loss): Location of Gain (Loss) Recognized in Income on Derivatives Gain (Loss) Recognized in Income on Derivatives Three Months Ended March 31, 2020 2019 (in millions) Interest rate contracts Loss on instruments designated at fair value and related derivatives $ 250 $ 156 Interest rate contracts Other income (loss) (3 ) (1 ) Foreign exchange contracts Loss on instruments designated at fair value and related derivatives (2 ) (1 ) Equity contracts Loss on instruments designated at fair value and related derivatives (1,698 ) 914 Credit contracts Loss on instruments designated at fair value and related derivatives 37 — Credit contracts Other income (loss) 51 (10 ) Other contracts (1) Other income (loss) 11 (6 ) Total $ (1,354 ) $ 1,052 (1) Consists of swap agreements entered into in conjunction with the sales of Visa Class B Shares.
Credit-Risk Related Contingent Features	The following table presents the amount of additional collateral that we would be required to post (from the current collateral level) related to derivative instruments with credit-risk related contingent features if our long-term ratings were downgraded by one or two notches. A downgrade by a single rating agency that does not result in a rating lower than a preexisting corresponding rating provided by another rating agency will generally not result in additional collateral. One-notch downgrade Two-notch downgrade (in millions) Amount of additional collateral to be posted upon downgrade $ 51 $ 100
Notional Value of Derivative Contracts	The following table summarizes the notional values of derivative contracts: March 31, 2020 December 31, 2019 (in millions) Interest rate: Futures and forwards $ 765,243 $ 597,980 Swaps 1,938,082 2,130,442 Options written 116,380 158,861 Options purchased 121,867 164,265 2,941,572 3,051,548 Foreign exchange: Swaps, futures and forwards 1,304,885 1,362,959 Options written 35,269 44,876 Options purchased 36,088 46,085 Spot 44,391 67,060 1,420,633 1,520,980 Commodities, equities and precious metals: Swaps, futures and forwards 73,740 55,678 Options written 35,418 39,035 Options purchased 45,636 49,517 154,794 144,230 Credit derivatives 95,364 90,049 Other contracts (1) 895 1,044 Total $ 4,613,258 $ 4,807,851 (1) Consists of swap agreements entered into in conjunction with the sales of Visa Class B Shares.

Fair Value Option (Tables)

Fair Value Option (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Option [Abstract]
Fair Value, Option, Quantitative Disclosures	The following table summarizes the fair value and unpaid principal balance for items we account for under FVO: Fair Value Unpaid Principal Balance Fair Value Over (Under) Unpaid Principal Balance (in millions) At March 31, 2020 Student loans held for investment $ 37 $ 39 $ (2 ) Commercial loans held for sale 206 263 (57 ) Fixed rate long-term debt 898 741 157 Hybrid instruments: Structured deposits 6,371 7,278 (907 ) Structured notes 7,477 8,176 (699 ) At December 31, 2019 Commercial loans held for sale $ 178 $ 189 $ (11 ) Securities sold under repurchase agreements 373 373 — Fixed rate long-term debt 959 741 218 Hybrid instruments: Structured deposits 7,209 7,491 (282 ) Structured notes 9,388 8,187 1,201
Components of Gain on Instruments at Fair Value and Related Derivatives	The following table summarizes the components of loss on instruments designated at fair value and related derivatives reflected in the consolidated statement of income (loss) for the three months ended March 31, 2020 and 2019 : Loans and Loans Held for Sale Long-Term Debt Hybrid Instruments Total (in millions) Three Months Ended March 31, 2020 Interest rate and other components (1) $ — $ (134 ) $ 1,579 $ 1,445 Credit risk component (2)(3) (54 ) — — (54 ) Total mark-to-market on financial instruments designated at fair value (54 ) (134 ) 1,579 1,391 Mark-to-market on related derivatives 37 150 (1,606 ) (1,419 ) Net realized gain on related long-term debt derivatives — 6 — 6 Gain (loss) on instruments designated at fair value and related derivatives $ (17 ) $ 22 $ (27 ) $ (22 ) Three Months Ended March 31, 2019 Interest rate and other components (1) $ — $ (69 ) $ (1,012 ) $ (1,081 ) Credit risk component (2) 3 — — 3 Total mark-to-market on financial instruments designated at fair value 3 (69 ) (1,012 ) (1,078 ) Mark-to-market on related derivatives — 53 1,006 1,059 Net realized gain on related long-term debt derivatives — 10 — 10 Gain (loss) on instruments designated at fair value and related derivatives $ 3 $ (6 ) $ (6 ) $ (9 ) (1) As it relates to hybrid instruments, interest rate and other components primarily includes interest rate, foreign exchange and equity contract risks. (2) The fair value movement on fair value option liabilities attributable to our own credit spread is recorded in other comprehensive income. (3) During the three months ended March 31, 2020, the loss in the credit risk component for loans and loans held for sale was attributable to the widening of credit spreads associated with certain commercial loans held for sale which were impacted by the spread of the COVID-19 pandemic.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2020
Equity [Abstract]
Accumulated Other Comprehensive Loss	The following table presents changes in accumulated other comprehensive income (loss) balances: Three Months Ended March 31, 2020 2019 (in millions) Unrealized gains (losses) on investment securities: Balance at beginning of period $ (116 ) $ (519 ) Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses on securities available-for-sale, net of tax of $1 million (1) 2 — Balance at beginning of period, adjusted (114 ) (519 ) Other comprehensive income (loss) for period: Net unrealized gains arising during period, net of tax of $245 million and $55 million, respectively 775 180 Reclassification adjustment for gains realized in net income (loss), net of tax of $(7) million and $(2) million, respectively (2) (21 ) (5 ) Reversal of provision for credit losses realized in net income (loss), net of tax of less than $1 million (3) 1 — Amortization of net unrealized losses on securities transferred from available-for-sale to held-to-maturity realized in net income (loss), net of tax of $1 million and $1 million, respectively (4) 3 4 Total other comprehensive income for period 758 179 Balance at end of period 644 (340 ) Unrealized gains (losses) on fair value option liabilities attributable to our own credit spread: Balance at beginning of period (9 ) 301 Other comprehensive income (loss) for period: Net unrealized gains (losses) arising during period, net of tax of $128 million and $(35) million, respectively 407 (111 ) Total other comprehensive income (loss) for period 407 (111 ) Balance at end of period 398 190 Unrealized gains (losses) on derivatives designated as cash flow hedges: Balance at beginning of period (151 ) (159 ) Other comprehensive income (loss) for period: Net unrealized gains arising during period, net of tax of $28 million and $2 million, respectively 85 6 Reclassification adjustment for losses realized in net income (loss), net of tax of $1 million and $2 million, respectively (5) 5 8 Total other comprehensive income for period 90 14 Balance at end of period (61 ) (145 ) Pension and postretirement benefit liability: Balance at beginning of period (3 ) 11 Other comprehensive income (loss) for period: Change in unfunded pension and postretirement liability, net of tax of nil and $(1) million, respectively — (3 ) Total other comprehensive loss for period — (3 ) Balance at end of period (3 ) 8 Total accumulated other comprehensive income (loss) at end of period $ 978 $ (287 ) (1) See Note 21, "New Accounting Pronouncements," for additional discussion. (2) Amount reclassified to net income (loss) is included in other securities gains, net in our consolidated statement of income (loss). (3) Changes in the allowance for credit losses on securities available-for-sale are included in the provision for credit losses in our consolidated statement of income (loss). (4) Amount amortized to net income (loss) is included in interest income in our consolidated statement of income (loss). During 2014, we transferred securities from available-for-sale to held-to-maturity. At the date of transfer, AOCI included net pretax unrealized losses related to the transferred securities which are being amortized over the remaining contractual life of each security as an adjustment of yield in a manner consistent with the amortization of any premium or discount. (5) Amount reclassified to net income (loss) is included in net interest income in our consolidated statement of income (loss).

Pension and Other Postretirem_2

Pension and Other Postretirement Benefits (Tables)	3 Months Ended
	Mar. 31, 2020
HSBC North America Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Components of Net Periodic Benefit Cost	Three Months Ended March 31, 2020 2019 (in millions) Interest cost on projected benefit obligation $ 12 $ 15 Expected return on plan assets (19 ) (18 ) Amortization of net actuarial loss 2 7 Administrative costs 1 1 Pension (income) expense $ (4 ) $ 5

Fee Income from Contracts wit_2

Fee Income from Contracts with Customers (Tables)	3 Months Ended
	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Fee Income	The following table summarizes fee income from contracts with customers disaggregated by type of activity, as well as a reconciliation to total other revenues, during the three months ended March 31, 2020 and 2019 . See Note 22, "Fee Income from Contracts with Customers," in our 2019 Form 10-K for a description of the various types of fee-based activities and how revenue associated with these activities is recognized. There have been no significant changes in these activities since December 31, 2019 . Three Months Ended March 31, 2020 2019 (in millions) Credit card fees, net $ 11 $ 12 Trust and investment management fees 31 30 Other fees and commissions: Account services 61 65 Credit facilities 73 69 Other fees 17 13 Total other fees and commissions 151 147 Servicing and other fees from HSBC affiliates 88 81 Insurance (1) 2 2 Total fee income from contracts with customers 283 272 Other non-fee revenues 104 118 Total other revenues (2) $ 387 $ 390 (1) Included within other income (loss) in the consolidated statement of income (loss). (2) 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.

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2020
Related Party Transactions [Abstract]
Summary of Related Party Transactions	The following tables present related party balances and the income (expense) generated by related party transactions: March 31, 2020 December 31, 2019 (in millions) Assets: Cash and due from banks $ 199 $ 850 Interest bearing deposits with banks 97 40 Securities purchased under agreements to resell (1) 673 4,600 Trading assets 159 79 Loans 3,087 2,343 Other (2) 728 456 Total assets $ 4,943 $ 8,368 Liabilities: Deposits $ 17,360 $ 9,000 Trading liabilities 402 293 Short-term borrowings 5,418 1,166 Long-term debt 4,849 7,848 Other (2) 212 931 Total liabilities $ 28,241 $ 19,238 (1) Reflects purchases of securities under which other HSBC affiliates have agreed to repurchase. (2) Other assets and other liabilities primarily consist of derivative balances associated with hedging activities and other miscellaneous account receivables and payables. Three Months Ended March 31, 2020 2019 (in millions) Income (Expense): Interest income $ 26 $ 43 Interest expense (120 ) (124 ) Net interest expense (94 ) (81 ) Trading revenue (expense) (261 ) (1,514 ) Servicing and other fees from HSBC affiliates: HSBC Bank plc 47 35 HSBC Markets (USA) Inc. ("HMUS") 24 30 Other HSBC affiliates 17 16 Total servicing and other fees from HSBC affiliates 88 81 Gain (loss) on instruments designated at fair value and related derivatives (1,606 ) 1,008 Support services from HSBC affiliates: HTSU (263 ) (277 ) HMUS (27 ) (27 ) Other HSBC affiliates (92 ) (76 ) Total support services from HSBC affiliates (382 ) (380 ) Rental income from HSBC affiliates, net (1) 12 12 Stock based compensation expense (2) (6 ) (6 ) (1) We receive rental income from our affiliates, and in some cases pay rental expense to our affiliates, for rent on certain office space. Net rental income from our affiliates is recorded as a component of occupancy expense, net in our consolidated statement of income (loss). (2) Employees may participate in one or more stock compensation plans sponsored by HSBC. These expenses are included in salaries and employee benefits in our consolidated statement of income (loss). Certain employees are also eligible to participate in a defined benefit pension plan and other postretirement plans sponsored by HSBC North America which are discussed in Note 12, "Pension and Other Postretirement Benefits."
Schedule of Assets by Related Party	At March 31, 2020 and December 31, 2019 , we had the following loan balances outstanding with HSBC affiliates: March 31, 2020 December 31, 2019 (in millions) HMUS and subsidiaries $ 3,032 $ 2,296 Other short-term affiliate lending 55 47 Total loans $ 3,087 $ 2,343

Business Segments (Tables)

Business Segments (Tables)	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Summary on Reconciliation of Results under Group Reporting Basis to US GAAP	The following table summarizes the results for each segment on a Group Reporting Basis, as well as provides a reconciliation of total results under the Group Reporting Basis to U.S. GAAP consolidated totals: Group Reporting Basis Consolidated Amounts RBWM CMB GB&M PB CC Total Group Reporting Basis Adjustments (1) Group Reporting Basis Reclassi- fications (2) U.S. GAAP Consolidated Totals (in millions) Three Months Ended March 31, 2020 Net interest income $ 195 $ 208 $ 81 $ 31 $ 4 $ 519 $ 3 $ (18 ) $ 504 Other operating income 59 58 264 16 (26 ) 371 (4 ) 20 387 Total operating income 254 266 345 47 (22 ) 890 (1 ) 2 891 Expected credit losses / provision for credit losses 140 123 115 — 1 379 347 — 726 114 143 230 47 (23 ) 511 (348 ) 2 165 Operating expenses 660 146 187 370 146 1,509 94 2 1,605 Profit (loss) before income tax $ (546 ) $ (3 ) $ 43 $ (323 ) $ (169 ) $ (998 ) $ (442 ) $ — $ (1,440 ) Balances at end of period: Total assets $ 18,954 $ 31,540 $ 114,802 $ 7,159 $ 97,154 $ 269,609 $ (64,532 ) $ — $ 205,077 Total loans, net 17,701 30,370 22,461 6,084 2,039 78,655 (4,596 ) 6,738 80,797 Goodwill — 358 — — — 358 100 — 458 Total deposits 39,083 32,309 40,417 8,201 4,305 124,315 (7,066 ) 19,474 136,723 Three Months Ended March 31, 2019 Net interest income $ 221 $ 201 $ 151 $ 37 $ 14 $ 624 $ 6 $ (68 ) $ 562 Other operating income 65 58 175 16 24 338 (17 ) 69 390 Total operating income 286 259 326 53 38 962 (11 ) 1 952 Expected credit losses / provision for credit losses 21 6 (17 ) (1 ) 1 10 41 7 58 265 253 343 54 37 952 (52 ) (6 ) 894 Operating expenses 311 138 206 53 40 748 8 (6 ) 750 Profit (loss) before income tax $ (46 ) $ 115 $ 137 $ 1 $ (3 ) $ 204 $ (60 ) $ — $ 144 Balances at end of period: Total assets $ 18,733 $ 25,612 $ 78,899 $ 6,686 $ 79,715 $ 209,645 $ (28,724 ) $ — $ 180,921 Total loans, net 16,885 24,447 20,068 5,584 2,230 69,214 (1,797 ) 3,034 70,451 Goodwill 581 358 — 321 — 1,260 347 — 1,607 Total deposits 33,459 22,323 28,274 7,540 6,629 98,225 (2,827 ) 18,241 113,639 (1) Represents adjustments associated with differences between U.S. GAAP and the Group Reporting Basis. (2) Represents differences in financial statement presentation between U.S. GAAP and the Group Reporting Basis.

Retained Earnings and Regulat_2

Retained Earnings and Regulatory Capital Requirements (Tables)	3 Months Ended
	Mar. 31, 2020
Banking and Thrift [Abstract]
Capital Amounts and Ratios in Accordance With Current Banking Regulations	The following table summarizes the capital amounts and ratios of HSBC USA and HSBC Bank USA, calculated in accordance with the Basel III rule at March 31, 2020 and December 31, 2019 : March 31, 2020 December 31, 2019 Capital Amount Well-Capitalized Ratio (1) Actual Ratio Capital Amount Well-Capitalized Ratio (1) Actual Ratio (dollars are in millions) Common equity Tier 1 ratio: HSBC USA $ 15,622 4.5 % (2) 11.9 % $ 15,876 4.5 % (2) 13.1 % HSBC Bank USA 17,814 6.5 14.0 18,043 6.5 15.2 Tier 1 capital ratio: HSBC USA 16,887 6.0 12.9 17,141 6.0 14.1 HSBC Bank USA 20,314 8.0 15.9 20,543 8.0 17.3 Total capital ratio: HSBC USA 20,932 10.0 16.0 19,743 10.0 16.3 HSBC Bank USA 23,063 10.0 18.1 22,724 10.0 19.2 Tier 1 leverage ratio: HSBC USA 16,887 4.0 (2) 9.0 17,141 4.0 (2) 9.9 HSBC Bank USA 20,314 5.0 11.0 20,543 5.0 12.0 Supplementary leverage ratio ("SLR"): HSBC USA 16,887 3.0 (3) 6.5 17,141 3.0 (3) 6.9 HSBC Bank USA 20,314 3.0 (3) 8.0 20,543 3.0 (3) 8.4 Risk-weighted assets: (4) HSBC USA 130,901 121,407 HSBC Bank USA 127,499 118,618 Adjusted quarterly average assets: (5) HSBC USA 187,962 173,270 HSBC Bank USA 184,851 170,722 Total leverage exposure: (6) HSBC USA 258,783 247,590 HSBC Bank USA 254,907 244,008 (1) HSBC USA and HSBC Bank USA are categorized as "well-capitalized," as defined by their principal regulators. To be categorized as well-capitalized under regulatory guidelines, a banking institution must have the ratios reflected in the above table, and must not be subject to a directive, order, or written agreement to meet and maintain specific capital levels. (2) There are no common equity Tier 1 or Tier 1 leverage ratio components in the definition of a well-capitalized bank holding company. The ratios shown are the regulatory minimums. (3) There is no SLR component in the definition of a well-capitalized banking institution. The ratios shown are the regulatory minimum ratios. (4) Calculated using the generally-applicable Standardized Approach. (5) Represents the Tier 1 leverage ratio denominator which reflects quarterly average assets adjusted for amounts permitted to be deducted from Tier 1 capital. (6) Represents the SLR denominator which includes adjusted quarterly average assets plus certain off-balance sheet exposures.

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	3 Months Ended
	Mar. 31, 2020
Variable Interest Entities [Abstract]
Summary of Assets and Liabilities Related to Consolidated Variable Interest Entities	The following table summarizes assets and liabilities related to our consolidated VIEs at March 31, 2020 and December 31, 2019 which are consolidated on our balance sheet. Assets and liabilities exclude intercompany balances that eliminate in consolidation. March 31, 2020 December 31, 2019 Consolidated Assets Consolidated Liabilities Consolidated Assets Consolidated Liabilities (in millions) Low income housing limited liability partnership: Other assets $ 92 $ — $ 98 $ — Interest, taxes and other liabilities — 31 — 38 Subtotal 92 31 98 38 Venture debt financing entity: Loans 39 — — — Interest, taxes and other liabilities — 1 — — Subtotal 39 1 — — Total $ 131 $ 32 $ 98 $ 38
Variable Interests Held by Us and Our Maximum Exposure to Loss Rising From Our Involvements in Those VIEs	The following table provides additional information on these unconsolidated VIEs, including the variable interests held by us and our maximum exposure to loss arising from our involvements in these VIEs, at March 31, 2020 and December 31, 2019 : Total Assets Held by Unconsolidated VIEs Carrying Value of Variable Interests Held Reported as Maximum Exposure to Loss Assets Liabilities (in millions) At March 31, 2020 Structured note vehicles $ 1,657 $ 510 $ 142 $ 1,515 Limited partnership investments 2,149 591 307 591 Total $ 3,806 $ 1,101 $ 449 $ 2,106 At December 31, 2019 Structured note vehicles $ 1,524 $ 510 $ 9 $ 1,515 Limited partnership investments 2,160 561 300 562 Total $ 3,684 $ 1,071 $ 309 $ 2,077

Guarantee Arrangements, Pledg_2

Guarantee Arrangements, Pledged Assets and Repurchase Agreements (Tables)	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Carrying Value and Contractual Amounts of our Sell Protection Credit Derivatives and Major Off-Balance Sheet Guarantee Arrangements	The following table presents total carrying value and contractual amounts of our sell protection credit derivatives and major off-balance sheet guarantee arrangements at March 31, 2020 and December 31, 2019 . Following the table is a description of the various arrangements. March 31, 2020 December 31, 2019 Carrying Value Notional / Maximum Exposure to Loss Carrying Value Notional / Maximum Exposure to Loss (in millions) Credit derivatives (1)(2) $ (2,064 ) $ 41,036 $ (63 ) $ 38,739 Financial standby letters of credit, net of participations (3)(4) — 5,805 — 5,657 Performance standby letters of credit, net of participations (3)(4) — 3,687 — 3,779 Total $ (2,064 ) $ 50,528 $ (63 ) $ 48,175 (1) Includes $19,399 million and $18,391 million of notional issued for the benefit of HSBC affiliates at March 31, 2020 and December 31, 2019 , respectively. (2) For credit derivatives, the maximum loss is represented by the notional amounts without consideration of mitigating effects from collateral or recourse arrangements. (3) Includes $1,649 million and $1,623 million of both financial and performance standby letters of credit issued for the benefit of HSBC affiliates at March 31, 2020 and December 31, 2019 , respectively. (4) For standby letters of credit, maximum loss represents losses to be recognized assuming the letters of credit have been fully drawn and the obligors have defaulted with zero recovery.
Net Credit Derivative Positions	The following table summarizes our net credit derivative positions at March 31, 2020 and December 31, 2019 : March 31, 2020 December 31, 2019 Carrying / Fair Value Notional Carrying / Fair Value Notional (in millions) Sell-protection credit derivative positions $ (2,064 ) $ 41,036 $ (63 ) $ 38,739 Buy-protection credit derivative positions 1,783 54,328 77 51,310 Net position (1) $ (281 ) $ 13,292 $ 14 $ 12,571 (1) Positions are presented net in the table above to provide a complete analysis of our risk exposure and depict the way we manage our credit derivative portfolio. The offset of the sell-protection credit derivatives against the buy-protection credit derivatives may not be legally binding in the absence of master netting agreements with the same counterparty. Furthermore, the credit loss triggering events for individual sell protection credit derivatives may not be the same or occur in the same period as those of the buy protection credit derivatives thereby not providing an exact offset.
Summary of Credit Ratings of Credit Risk Related Guarantees	The following table summarizes the credit ratings related to guarantees including the ratings of counterparties against which we sold credit protection and financial standby letters of credit at March 31, 2020 as an indicative proxy of payment risk: Average Life (in years) Credit Ratings of the Obligors Notional/Contractual Amounts Investment Non-Investment Grade Total (dollars are in millions) Sell-protection Credit Derivatives (1) Single name credit default swaps ("CDS") 3.2 $ 20,231 $ 9,090 $ 29,321 Index credit derivatives 4.3 6,159 4,300 10,459 Total return swaps 2.3 1,062 194 1,256 Subtotal 27,452 13,584 41,036 Standby Letters of Credit (2) 1.2 7,598 1,894 9,492 Total $ 35,050 $ 15,478 $ 50,528 (1) The credit ratings in the table represent external credit ratings for classification as investment grade and non-investment grade. (2) External ratings for most of the obligors are not available. Presented above are the internal credit ratings which are developed using similar methodologies and rating scale equivalent to external credit ratings for purposes of classification as investment grade and non-investment grade.
Summary of Pledged Assets Included in Consolidated Balance Sheet	Pledged Assets Pledged assets included in the consolidated balance sheet consisted of the following: March 31, 2020 December 31, 2019 (in millions) Interest bearing deposits with banks $ 4,816 $ 2,682 Trading assets (1) 6,633 525 Securities available-for-sale (2) 14,986 6,814 Securities held-to-maturity (2) 1,573 1,688 Loans (3) 13,316 14,342 Other assets (4) 6,634 3,517 Total $ 47,958 $ 29,568 (1) Trading assets are primarily pledged against liabilities associated with repurchase agreements. (2) Securities are primarily pledged against derivatives, public fund deposits, trust deposits and various short-term and long term borrowings, as well as providing capacity for potential secured borrowings from the FHLB and the Federal Reserve Bank of New York. (3) Loans are primarily residential mortgage loans pledged against current and potential borrowings from the FHLB and the Federal Reserve Bank of New York. (4) Other assets represent cash on deposit with non-banks related to derivative collateral support agreements.
Offsetting Assets and Liabilities	The following table provides information about resale and repurchase agreements that are subject to offset at March 31, 2020 and December 31, 2019 : Gross Amounts Not Offset in the Balance Sheet Gross Amounts Recognized Gross Amounts Offset in the Balance Sheet (1) Net Amounts Presented in the Balance Sheet Financial Instruments (2) Cash Collateral Received / Pledged Net Amount (3) (in millions) At March 31, 2020 Assets: Securities purchased under resale agreements $ 8,241 $ 3,598 $ 4,643 $ 4,641 $ — $ 2 Liabilities: Securities sold under repurchase agreements $ 16,096 $ 3,598 $ 12,498 $ 12,453 $ — $ 45 At December 31, 2019 Assets: Securities purchased under resale agreements $ 19,167 $ 1,329 $ 17,838 $ 17,832 $ — $ 6 Liabilities: Securities sold under repurchase agreements $ 2,401 $ 1,329 $ 1,072 $ 1,068 $ — $ 4 (1) Represents recognized amount of resale and repurchase agreements with counterparties subject to legally enforceable netting agreements that meet the applicable netting criteria as permitted by generally accepted accounting principles. (2) Represents securities received or pledged to cover financing transaction exposures. (3) Represents the amount of our exposure that is not collateralized / covered by pledged collateral.
Class of Collateral Pledged and Remaining Contractual Maturity of Repurchase Agreements Accounted for as Secured Borrowings	The following table provides the class of collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings at March 31, 2020 and December 31, 2019 : Overnight and Continuous Up to 30 Days 31 to 90 Days 91 Days to One Year Greater Than One Year Total (in millions) At March 31, 2020 U.S. Treasury, U.S. Government sponsored and U.S. Government agency securities $ 6,719 $ 6,148 $ 3,229 $ — $ — $ 16,096 At December 31, 2019 U.S. Treasury, U.S. Government sponsored and U.S. Government agency securities $ 2,401 $ — $ — $ — $ — $ 2,401

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Assets and Liabilities Recorded at Fair Value on a Recurring Basis	The following table presents information about our assets and liabilities measured at fair value on a recurring basis at March 31, 2020 and December 31, 2019 , and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. Unless otherwise noted below, assets and liabilities in the following table are recorded at fair value through net income (loss). Fair Value Measurements on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Gross Balance Netting (6) Net Balance (in millions) Assets: Trading assets, excluding derivatives: U.S. Treasury, U.S. Government agencies and sponsored enterprises $ 8,207 $ 60 $ — $ 8,267 $ — $ 8,267 Asset-backed securities: Collateralized debt obligations — 67 — 67 — 67 Residential mortgages — — 16 16 — 16 Student loans — 73 — 73 — 73 Corporate and other domestic debt securities — — 465 465 — 465 Debt securities issued by foreign entities 8,803 97 — 8,900 — 8,900 Equity securities 1,432 — — 1,432 — 1,432 Precious metals trading — 4,604 — 4,604 — 4,604 Derivatives: (1) Interest rate contracts 11 19,790 41 19,842 — 19,842 Foreign exchange contracts — 31,123 2 31,125 — 31,125 Equity contracts 1 4,380 225 4,606 — 4,606 Precious metals contracts 1 2,210 — 2,211 — 2,211 Credit contracts — 1,640 351 1,991 — 1,991 Other contracts (2) — — 9 9 — 9 Derivatives netting — — — — (54,277 ) (54,277 ) Total derivatives 13 59,143 628 59,784 (54,277 ) 5,507 Securities available-for-sale: (3) U.S. Treasury, U.S. Government agencies and sponsored enterprises 21,844 14,573 — 36,417 — 36,417 Asset-backed securities: Home equity — 28 — 28 — 28 Other — — 116 116 — 116 Debt securities issued by foreign entities 4,193 38 — 4,231 — 4,231 Loans (4) — 37 — 37 — 37 Loans held for sale (4) — 206 — 206 — 206 Other assets: Equity securities — 147 — 147 — 147 Equity securities measured at net asset value (5) — — — 131 — 131 Total assets $ 44,492 $ 79,073 $ 1,225 $ 124,921 $ (54,277 ) $ 70,644 Liabilities: Domestic deposits (4) $ — $ 5,718 $ 653 $ 6,371 $ — $ 6,371 Trading liabilities, excluding derivatives 429 5 — 434 — 434 Derivatives: (1) Interest rate contracts 11 22,481 — 22,492 — 22,492 Foreign exchange contracts 7 29,732 5 29,744 — 29,744 Equity contracts — 3,909 221 4,130 — 4,130 Precious metals contracts 147 2,040 — 2,187 — 2,187 Credit contracts — 2,075 253 2,328 — 2,328 Other contracts (2) — — 67 67 — 67 Derivatives netting — — — — (57,230 ) (57,230 ) Total derivatives 165 60,237 546 60,948 (57,230 ) 3,718 Long-term debt (4) — 8,004 371 8,375 — 8,375 Total liabilities $ 594 $ 73,964 $ 1,570 $ 76,128 $ (57,230 ) $ 18,898 Fair Value Measurements on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Gross Balance Netting (6) Net Balance (in millions) Assets: Trading assets, excluding derivatives: U.S. Treasury, U.S. Government agencies and sponsored enterprises $ 6,763 $ 38 $ — $ 6,801 $ — $ 6,801 Asset-backed securities: Collateralized debt obligations — 71 — 71 — 71 Residential mortgages — — 17 17 — 17 Student loans — 80 — 80 — 80 Corporate and other domestic debt securities — — 510 510 — 510 Debt securities issued by foreign entities 10,095 221 — 10,316 — 10,316 Equity securities 5,693 — — 5,693 — 5,693 Precious metals trading — 1,909 — 1,909 — 1,909 Derivatives: (1) Interest rate contracts 110 12,275 10 12,395 — 12,395 Foreign exchange contracts 80 16,456 — 16,536 — 16,536 Equity contracts — 4,922 185 5,107 — 5,107 Precious metals contracts 70 1,085 3 1,158 — 1,158 Credit contracts — 1,060 79 1,139 — 1,139 Other contracts (2) — — 10 10 — 10 Derivatives netting — — — — (33,193 ) (33,193 ) Total derivatives 260 35,798 287 36,345 (33,193 ) 3,152 Securities available-for-sale: (3) U.S. Treasury, U.S. Government agencies and sponsored enterprises 17,532 14,702 — 32,234 — 32,234 Asset-backed securities: Home equity — 32 — 32 — 32 Other — — 111 111 — 111 Debt securities issued by foreign entities 3,158 128 — 3,286 — 3,286 Loans held for sale (4) — 178 — 178 — 178 Other assets: Equity securities — 147 — 147 — 147 Equity securities measured at net asset value (5) — — — 136 — 136 Total assets $ 43,501 $ 53,304 $ 925 $ 97,866 $ (33,193 ) $ 64,673 Liabilities: Domestic deposits (4) $ — $ 6,435 $ 774 $ 7,209 $ — $ 7,209 Trading liabilities, excluding derivatives 1,182 124 — 1,306 — 1,306 Derivatives: (1) Interest rate contracts 3 13,570 — 13,573 — 13,573 Foreign exchange contracts — 15,805 1 15,806 — 15,806 Equity contracts — 3,955 113 4,068 — 4,068 Precious metals contracts 80 1,306 3 1,389 — 1,389 Credit contracts — 1,048 20 1,068 — 1,068 Other contracts (2) — — 85 85 — 85 Derivatives netting — — — — (33,900 ) (33,900 ) Total derivatives 83 35,684 222 35,989 (33,900 ) 2,089 Short-term borrowings (4) — 373 — 373 — 373 Long-term debt (4) — 9,993 354 10,347 — 10,347 Total liabilities $ 1,265 $ 52,609 $ 1,350 $ 55,224 $ (33,900 ) $ 21,324 (1) Includes trading derivative assets of $5,393 million and $3,055 million and trading derivative liabilities of $3,489 million and $1,929 million at March 31, 2020 and December 31, 2019 , respectively, as well as derivatives held for hedging and commitments accounted for as derivatives. See Note 9, "Derivative Financial Instruments," for additional information. Excluding changes in fair value of a derivative instrument associated with a qualifying cash flow hedge, which are recognized initially in other comprehensive income, derivative assets and liabilities are recorded at fair value through net income (loss). (2) Consists of swap agreements entered into in conjunction with the sales of Visa Class B Shares. (3) Securities available-for-sale are recorded at fair value through other comprehensive income. Changes in the allowance for credit losses on securities available-for-sale are recorded through net income (loss). (4) See Note 10, "Fair Value Option," for additional information. Excluding the fair value movement on fair value option liabilities attributable to our own credit spread, which is recorded in other comprehensive income, fair value option assets and liabilities are recorded at fair value through net income (loss). (5) Investments that are measured at fair value using the net asset value per share practical expedient have not been classified in the fair value hierarchy. (6) Represents counterparty and cash collateral netting which allow the offsetting of amounts relating to certain contracts if certain conditions are met.
Changes in Fair Value of Level 3 Assets and Liabilities	The following table summarizes additional information about changes in the fair value of Level 3 assets and liabilities during the three months ended March 31, 2020 and 2019 . As a risk management practice, we may risk manage the Level 3 assets and liabilities, in whole or in part, using securities and derivative positions that are classified as Level 1 or Level 2 measurements within the fair value hierarchy. Since those Level 1 and Level 2 risk management positions are not included in the table below, the information provided does not reflect the effect of such risk management activities related to the Level 3 assets and liabilities. Jan. 1, 2020 Total Realized / Unrealized Gains (Losses) Included in Purch- ases Issu- ances Settle- ments Transfers Into Level 3 Transfers Out of Level 3 Mar. 31, Current Period Unrealized Gains Earnings Other Compre- hensive Income Earnings Other Compre- (in millions) Assets: Trading assets, excluding derivatives: (1) Residential mortgage asset-backed securities $ 17 $ (1 ) $ — $ — $ — $ — $ — $ — $ 16 $ (1 ) $ — Corporate and other domestic debt securities 510 (45 ) — — — — — — 465 (45 ) — Derivatives, net: (2) Interest rate contracts 10 31 — — — — — — 41 31 — Foreign exchange contracts (1 ) (2 ) — — — — — — (3 ) (2 ) — Equity contracts 72 (74 ) — — — 6 — — 4 12 — Credit contracts 59 35 — — — 4 — — 98 35 — Other contracts (3) (75 ) 11 — — — 6 — — (58 ) — — Other asset-backed securities available-for-sale (4) 111 — 5 — — — — — 116 — 5 Total assets $ 703 $ (45 ) $ 5 $ — $ — $ 16 $ — $ — $ 679 $ 30 $ 5 Liabilities: Domestic deposits (5) $ (774 ) $ 1 $ 18 $ — $ (36 ) $ 105 $ — $ 33 $ (653 ) $ — $ 18 Long-term debt (5) (354 ) 5 10 — (101 ) 65 — 4 (371 ) 4 10 Total liabilities $ (1,128 ) $ 6 $ 28 $ — $ (137 ) $ 170 $ — $ 37 $ (1,024 ) $ 4 $ 28 Jan. 1, 2019 Total Realized / Unrealized Gains (Losses) Included in Purch- ases Issu- ances Settle- ments Transfers Into Level 3 Transfers Out of Level 3 Mar. 31, 2019 Current Period Unrealized Gains (Losses) Still Held Included in Earnings Other Compre- hensive Income Earnings Other Compre- hensive Income (in millions) Assets: Trading assets, excluding derivatives: (1) Collateralized debt obligations $ 100 $ 1 $ — $ — $ — $ (11 ) $ — $ — $ 90 $ (6 ) $ — Residential mortgage asset-backed securities 16 — — — — — — — 16 — — Student loan asset-backed securities 92 5 — — — (2 ) — — 95 3 — Corporate and other domestic debt securities 1,803 — — — — (1,293 ) — — 510 — — Derivatives, net: (2) Interest rate contracts 2 5 — — — — — — 7 5 — Foreign exchange contracts (1 ) — — — — — — — (1 ) — — Equity contracts (52 ) 71 — — — 4 — 1 24 75 — Credit contracts 52 (37 ) — — — 38 — — 53 — — Other contracts (3) (35 ) (6 ) — — — 4 — — (37 ) — — Other asset-backed securities available-for-sale (4) 107 — 2 — — — — — 109 — 2 Other assets (6) 4 — — — — — — — 4 — — Total assets $ 2,088 $ 39 $ 2 $ — $ — $ (1,260 ) $ — $ 1 $ 870 $ 77 $ 2 Liabilities: Domestic deposits (5) $ (925 ) $ (29 ) $ (5 ) $ — $ (96 ) $ 45 $ — $ 61 $ (949 ) $ (100 ) $ (5 ) Long-term debt (5) (412 ) (28 ) (3 ) — (31 ) 13 — 8 (453 ) (49 ) (3 ) Total liabilities $ (1,337 ) $ (57 ) $ (8 ) $ — $ (127 ) $ 58 $ — $ 69 $ (1,402 ) $ (149 ) $ (8 ) (1) Gains (losses) on trading assets, excluding derivatives are included in trading revenue in the consolidated statement of income (loss). (2) Level 3 net derivatives included derivative assets of $628 million and derivative liabilities of $546 million at March 31, 2020 and derivative assets of $288 million and derivative liabilities of $242 million at March 31, 2019 . Gains (losses) on derivatives, net are predominantly included in trading revenue and loss on instruments designated at fair value and related derivatives in the consolidated statement of income (loss). (3) Consists of swap agreements entered into in conjunction with the sales of Visa Class B Shares. Gains (losses) on these swap agreements are included in other income (loss) in the consolidated statement of income (loss). (4) Realized gains (losses) on securities available-for-sale are included in other securities gains, net in the consolidated statement of income (loss). Changes in the allowance for credit losses on securities available-for-sale are included in the provision for credit losses in the consolidated statement of income (loss). Unrealized gains (losses) on securities available-for-sale are included in other comprehensive income. (5) Excluding unrealized gains (losses) on fair value option liabilities attributable to our own credit spread, which are recorded in other comprehensive income, gains (losses) on fair value option liabilities are included in loss on instruments designated at fair value and related derivatives in the consolidated statement of income (loss). (6) Represented contingent consideration receivable associated with the sale of a portion of our PB business, which concluded in 2019. Gains (losses) associated with this transaction were included in other income (loss) in the consolidated statement of income (loss).
Quantitative Information about Recurring Fair Value Measurement of Assets and Liabilities Classified as Level 3	The following table presents quantitative information about the unobservable inputs used to determine the recurring fair value measurement of assets and liabilities classified as Level 3 fair value measurements at March 31, 2020 and December 31, 2019 : March 31, 2020 Financial Instrument Type Fair Value (in millions) Valuation Technique(s) Significant Unobservable Inputs Range of Inputs Weighted Average (1) Residential mortgage asset-backed securities $ 16 Broker quotes or consensus pricing and, where applicable, discounted cash flows Prepayment rates 3% N/A Conditional default rates 8% N/A Loss severity rates 70% N/A Discount margin 879bps N/A Corporate and other domestic debt securities $ 465 Discounted cash flows Spread volatility on collateral assets 4% N/A Correlation between insurance claim 80% N/A Interest rate derivative contracts $ 41 Market comparable adjusted for probability to fund and, where applicable, discounted cash flows Probability to fund for rate lock commitments 41% - 100% 72% Likelihood of transaction being executed 90% N/A Foreign exchange derivative contracts (2) $ (3 ) Option pricing model Implied volatility of currency pairs 10% - 17% 13% Equity derivative contracts (2) $ 4 Option pricing model Equity / Equity Index volatility 6% - 81% 35% Equity / Equity and Equity / Index correlation 43% - 78% 50% Equity dividend yields and forward price (7)% - 3% 0% Credit derivative contracts $ 98 Option pricing model and, where applicable, discounted cash flows Credit default swap spreads 200bps N/A Other derivative contracts $ (58 ) Discounted cash flows Conversion rate 1.6 times N/A Expected duration 3 years N/A Other asset-backed securities available-for-sale $ 116 Discounted cash flows Market assumptions related to yields for comparable instruments 4% - 5% 5% Domestic deposits (structured deposits) (2)(3) $ (653 ) Option adjusted discounted cash flows Implied volatility of currency pairs 10% - 17% 13% Equity / Equity Index volatility 7% - 60% 29% Equity / Equity and Equity / Index correlation 43% - 60% 46% Long-term debt (structured notes) (2)(3) $ (371 ) Option adjusted discounted cash flows Implied volatility of currency pairs 10% - 17% 13% Equity / Equity Index volatility 8% - 71% 33% Equity / Equity and Equity / Index correlation 55% - 78% 66% December 31, 2019 Financial Instrument Type Fair Value (in millions) Valuation Technique(s) Significant Unobservable Inputs Range of Inputs Weighted Average (1) Residential mortgage asset-backed securities $ 17 Broker quotes or consensus pricing and, where applicable, discounted cash flows Prepayment rates 1% N/A Conditional default rates 8% N/A Loss severity rates 70% N/A Discount margin 600bps N/A Corporate and other domestic debt securities $ 510 Discounted cash flows Spread volatility on collateral assets 4% N/A Correlation between insurance claim shortfall and collateral value 80% N/A Interest rate derivative contracts $ 10 Market comparable adjusted for probability to fund and, where applicable, discounted cash flows Probability to fund for rate lock commitments 42% - 100% 80% Likelihood of transaction being executed 90% N/A Foreign exchange derivative contracts (2) $ (1 ) Option pricing model Implied volatility of currency pairs 6% - 11% 8% Equity derivative contracts (2) $ 72 Option pricing model Equity / Equity Index volatility 7% - 36% 22% Equity / Equity and Equity / Index correlation 43% - 79% 49% Equity dividend yields 0% - 4% 2% Credit derivative contracts $ 59 Option pricing model and, where applicable, discounted cash flows Credit default swap spreads 41bps N/A Other derivative contracts $ (75 ) Discounted cash flows Conversion rate 1.6 times N/A Expected duration 3 years N/A Other asset-backed securities available-for-sale $ 111 Discounted cash flows Market assumptions related to yields for comparable instruments 0% - 3% 2% Domestic deposits (structured deposits) (2)(3) $ (774 ) Option adjusted discounted cash flows Implied volatility of currency pairs 6% - 11% 8% Equity / Equity Index volatility 7% - 28% 13% Equity / Equity and Equity / Index correlation 43% - 49% 46% Long-term debt (structured notes) (2)(3) $ (354 ) Option adjusted discounted cash flows Implied volatility of currency pairs 6% - 11% 8% Equity / Equity Index volatility 7% - 29% 16% Equity / Equity and Equity / Index correlation 54% - 79% 64% (1) For other asset-backed securities available-for-sale, the value shown is the arithmetic average. For foreign exchange derivatives, equity derivatives, structured deposits and structured notes, weighted averages are calculated based on the fair value of the instruments. For all remaining instrument types, weighted averages are calculated based on the notional value of the instruments. (2) We are the client-facing entity and we enter into identical but opposite derivatives to transfer the resultant risks to our affiliates. With the exception of counterparty credit risks, we are market neutral. The corresponding intra-group derivatives are presented as equity derivatives and foreign exchange derivatives in the table. (3) Structured deposits and structured notes contain embedded derivative features whose fair value measurements contain significant Level 3 inputs. See equity and foreign exchange derivatives below for a discussion of the uncertainty of Level 3 inputs related to structured deposits and structured notes. N/A Not Applicable
Assets and Liabilities Recorded at Fair Value on a Non Recurring Basis	The following table presents the fair value hierarchy level within which the fair value of the financial and non-financial assets has been recorded at March 31, 2020 and December 31, 2019 . The gains (losses) during the three months ended March 31, 2020 and 2019 are also included. Non-Recurring Fair Value Measurements Total Gains (Losses) For the Three Months Ended March 31, 2020 Level 1 Level 2 Level 3 Total (in millions) Residential mortgage loans held for sale (1) $ — $ 7 $ — $ 7 $ — Consumer loans (2) — 330 — 330 3 Commercial loans (3) — — 58 58 (53 ) Real estate owned (4) — 3 — 3 — Goodwill (5) — — — — (784 ) Leases (6) — — 25 25 (68 ) Total assets at fair value on a non-recurring basis $ — $ 340 $ 83 $ 423 $ (902 ) Non-Recurring Fair Value Measurements Total Gains (Losses) For the Three Months Ended March 31, 2019 Level 1 Level 2 Level 3 Total (in millions) Residential mortgage loans held for sale (1) $ — $ 12 $ — $ 12 $ — Consumer loans (2) — 14 — 14 (2 ) Commercial loans (3) — — 50 50 (1 ) Real estate owned (4) — 6 — 6 (1 ) Goodwill (5) — — 372 372 — Leases (6) — — 2 2 — Total assets at fair value on a non-recurring basis $ — $ 32 $ 424 $ 456 $ (4 ) (1) At March 31, 2020 and December 31, 2019, the fair value of the loans held for sale was below cost. (2) Represents residential mortgage loans held for investment whose carrying amount was adjusted during the period based on the fair value of the underlying collateral. The increase at March 31, 2020 reflects the impact of adopting new accounting guidance which requires expected recoveries related to subsequent increases in the fair value of collateral for collateral-dependent loans to be recognized in the allowance for credit losses beginning January 1, 2020. See Note 21, "New Accounting Pronouncements," for additional discussion. (3) Certain commercial loans are individually assessed for impairment. We measure the credit impairment of a collateral-dependent loan based on the fair value of the collateral asset. The collateral often involves real estate properties that are illiquid due to market conditions. As a result, these loans are classified as a Level 3 fair value measurement within the fair value hierarchy. (4) Real estate owned is required to be reported on the balance sheet net of transactions costs. The real estate owned amounts in the table above reflect the fair value unadjusted for transaction costs. (5) During the first quarter of 2020, the goodwill allocated to our RBWM and PB businesses were both written down to $0 million . During the third quarter of 2019, the goodwill allocated to our RBWM business was written down to $372 million . See Note 8, "Goodwill," in this Form 10-Q and Note 9, "Goodwill" in our 2019 Form 10-K for further discussion of the results of our goodwill impairment testing, including the events and circumstances leading to the impairments. (6) Beginning in the fourth quarter of 2019 and into the first quarter of 2020, we determined that we would exit certain branches and, as a result, the lease ROU assets and leasehold improvement assets associated with these branches were written down based on their estimated remaining useful lives. See Note 2, "Strategic Initiatives," in this Form 10-Q and Note 10, "Leases" in our 2019 Form 10-K for further discussion.
Quantitative Information about Non Recurring Fair Value Measurement of Assets and Liabilities	The following tables present quantitative information about non-recurring fair value measurements of assets and liabilities classified with Level 3 of the fair value hierarchy at March 31, 2020 and December 31, 2019 : At March 31, 2020 Financial Instrument Type Fair Value (in millions) Valuation Technique(s) Significant Unobservable Inputs Range of Inputs Weighted Average (1) Commercial loans $ 58 Valuation of third party appraisal Loss severity rates 9% - 93% 53% At December 31, 2019 Financial Instrument Type Fair Value (in millions) Valuation Technique(s) Significant Unobservable Inputs Range of Inputs Weighted Average (1) Commercial loans $ 50 Valuation of third party appraisal Loss severity rates 9% - 100% 45% (1) Weighted average is calculated based on the carrying value of the loans.
Additional Information Relating to Asset-Backed Securities and Collateralized Debt Obligations	The following tables provide additional information relating to our asset-backed securities, including CDOs, at March 31, 2020 : Trading asset-backed securities: Rating of Securities: (1) Collateral Type: Level 2 Level 3 Total (in millions) AAA - A Collateralized debt obligations $ 39 $ — $ 39 Student loans 73 — 73 Total AAA -A 112 — 112 BBB - B Collateralized debt obligations 28 — 28 CCC - Unrated Residential mortgages - Subprime — 16 16 $ 140 $ 16 $ 156 Available-for-sale asset-backed securities: Rating of Securities: (1) Collateral Type: Level 2 Level 3 Total (in millions) AAA - A Home equity - Alt A $ 28 $ — $ 28 BBB -B Other — 116 116 $ 28 $ 116 $ 144 (1) We utilize S&P as the primary source of credit ratings in the tables above. If S&P ratings are not available, ratings by Moody's and Fitch are used in that order. Ratings for CDOs represent the ratings associated with the underlying collateral.
Carrying Value and Estimated Fair Value of Financial Instruments	The following table summarizes the carrying value and estimated fair value of our financial instruments, excluding financial instruments that are carried at fair value on a recurring basis, at March 31, 2020 and December 31, 2019 , and their classification within the fair value hierarchy: March 31, 2020 Carrying Value Fair Value Level 1 Level 2 Level 3 (in millions) Financial assets: Short-term financial assets, net of allowance for credit losses $ 27,490 $ 27,490 $ 983 $ 26,496 $ 11 Federal funds sold and securities purchased under agreements to resell 4,643 4,643 — 4,643 — Securities held-to-maturity, net of allowance for credit losses 12,981 13,446 — 13,446 — Commercial loans, net of allowance for credit losses 60,519 60,987 — — 60,987 Commercial loans held for sale 28 28 — 28 — Consumer loans, net of allowance for credit losses 20,278 19,953 — — 19,953 Residential mortgage loans held for sale 51 51 — 51 — Financial liabilities: Short-term financial liabilities $ 17,592 $ 17,592 $ — $ 17,579 $ 13 Deposits: Without fixed maturities 115,371 115,371 — 115,371 — Fixed maturities 14,981 14,917 — 14,917 — Long-term debt 16,402 16,485 — 16,485 — December 31, 2019 Carrying Value Fair Value Level 1 Level 2 Level 3 (in millions) Financial assets: Short-term financial assets $ 3,800 $ 3,800 $ 1,744 $ 2,038 $ 18 Federal funds sold and securities purchased under agreements to resell 17,838 17,838 — 17,838 — Securities held-to-maturity 13,293 13,431 — 13,431 — Commercial loans, net of allowance for credit losses 47,704 49,252 — — 49,252 Commercial loans held for sale 34 34 — 34 — Consumer loans, net of allowance for credit losses 20,212 19,889 — — 19,889 Residential mortgage loans held for sale 77 78 — 77 1 Financial liabilities: Short-term financial liabilities $ 3,304 $ 3,304 $ — $ 3,286 $ 18 Deposits: Without fixed maturities 96,161 96,161 — 96,161 — Fixed maturities 16,323 16,264 — 16,264 — Long-term debt 16,350 16,696 — 16,696 —

Strategic Initiatives (Details)

Strategic Initiatives (Details) - 2-year Restructuring Plan [Member] - USD ($) $ in Millions	24 Months Ended
	Dec. 31, 2021	Mar. 31, 2020
Forecast [Member]
Restructuring Cost and Reserve [Line Items]
Expected period for completion of restructuring plan	2 years
Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges, pre-tax		$ 350
Expected restructuring charges, after-tax		265
Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges, pre-tax		400
Expected restructuring charges, after-tax		$ 305

Strategic Initiatives - Restruc

Strategic Initiatives - Restructuring Liability (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	$ 0
Restructuring costs recorded during the period	33
Restructuring costs paid during the period	0
Restructuring liability at end of period	33
Severance and Other Employee Costs
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	0	[1]
Restructuring costs recorded during the period	9	[1]
Restructuring costs paid during the period	0	[1]
Restructuring liability at end of period	9	[1]
Lease Termination and Associated Costs
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	0	[2]
Restructuring costs recorded during the period	24	[2]
Restructuring costs paid during the period	0	[2]
Restructuring liability at end of period	$ 24	[2]
[1]	and other employee costs are included in salaries and employee benefits in the consolidated statement of income (loss), substantially all of which were reported in the Retail Banking & Wealth Management business segment for segment reporting purposes.
[2]	Primarily includes real estate taxes, service charges and decommissioning costs. Lease termination and associated costs are included in occupancy expense, net in the consolidated statement of income (loss) and were reported in the Corporate Center business segment for segment reporting purposes.

Strategic Initiatives - Branch

Strategic Initiatives - Branch Closings (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)branch	Dec. 31, 2019branch
Restructuring Cost and Reserve [Line Items]
Number of branches closing | branch	60	20
Allocated restructuring costs from HTSU	$ 8
Occupancy Expense, Net [Member]
Restructuring Cost and Reserve [Line Items]
Lease impairment charges	52
Fixed asset impairment charges	$ 16

Trading Assets and Liabilitie_2

Trading Assets and Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	$ 29,217	$ 28,452
Trading liabilities	3,923	3,235
U.S. Treasury [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	8,207	6,763
US Government agency issued or guaranteed [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	39	18
US Government-sponsored enterprises [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	21	20
Asset-backed securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	156	168
Corporate and foreign bonds [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	9,365	10,826
Equity securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	1,432	5,693
Precious metals [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	4,604	1,909
Trading liabilities	0	124
Securities sold, not yet purchased [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading liabilities	434	1,182
Derivatives, net [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	5,393	3,055
Derivatives, net [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading liabilities	$ 3,489	$ 1,929

Trading Assets and Liabilitie_3

Trading Assets and Liabilities - Additional Information (Detail) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Debt and Equity Securities, FV-NI [Line Items]
Derivatives included in trading assets, amount offset	[1],[2]	$ 6,178	$ 3,683
Derivatives included in trading liabilities, amount offset	[1],[2]	9,131	4,390
Trading Assets [Member]
Debt and Equity Securities, FV-NI [Line Items]
Derivatives included in trading assets, amount offset		6,137	2,538
Trading Liabilities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Derivatives included in trading liabilities, amount offset		$ 8,575	$ 4,351
[1]	Netting is performed at a counterparty level in cases where enforceable master netting agreements are in place, regardless of the type of derivative instrument. Therefore, we have not allocated netting to the different types of derivative instruments shown in the table above.
[2]	Represents the netting of cash collateral posted and received by counterparty under enforceable netting agreements.

Securities - Amortized Cost and

Securities - Amortized Cost and Fair Value of Asset Backed Securities (Detail) - USD ($) $ in Millions		Mar. 31, 2020		Jan. 01, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Securities available-for-sale, fair value		$ 40,792			$ 35,663
Securities available-for-sale, unrealized losses		(251)			(330)
Securities available-for-sale, unrealized gains		1,178			261
Securities available-for-sale, allowance for credit losses	[2]	(2)	[1]	$ (3)
Securities available-for-sale, amortized cost		39,867
Securities available-for-sale, amortized cost					35,732
Securities held-to-maturity, fair value		13,446			13,431
Securities held-to-maturity, unrealized losses		(4)			(27)
Securities held-to-maturity, unrealized gain		469			165
Securities held-to-maturity, allowance for credit losses	[2]	(2)	[1]	$ (2)
Securities held-to-maturity, amortized cost		12,983
Securities held-to-maturity, amortized cost					13,293
US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available-for-sale, fair value		17,291			16,078
Securities available-for-sale, unrealized losses		(209)			(269)
Securities available-for-sale, unrealized gains		607			128
Securities available-for-sale, allowance for credit losses	[1]	0
Securities available-for-sale, amortized cost		16,893
Securities available-for-sale, amortized cost					16,219
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available-for-sale, fair value		4,915			3,402
Securities available-for-sale, unrealized losses		(1)			(13)
Securities available-for-sale, unrealized gains		219			57
Securities available-for-sale, allowance for credit losses	[1]	0
Securities available-for-sale, amortized cost		4,697
Securities available-for-sale, amortized cost					3,358
Securities held-to-maturity, fair value		1,614			1,653
Securities held-to-maturity, unrealized losses		0			(1)
Securities held-to-maturity, unrealized gain		53			22
Securities held-to-maturity, allowance for credit losses	[1]	0
Securities held-to-maturity, amortized cost		1,561
Securities held-to-maturity, amortized cost					1,632
Collateralized Mortgage Obligations, Issued by U.S. Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available-for-sale, fair value		277			347
Securities available-for-sale, unrealized losses		(1)			(1)
Securities available-for-sale, unrealized gains		16			3
Securities available-for-sale, allowance for credit losses	[1]	0
Securities available-for-sale, amortized cost		262
Securities available-for-sale, amortized cost					345
Securities held-to-maturity, fair value		1,358			1,454
Securities held-to-maturity, unrealized losses		0			(4)
Securities held-to-maturity, unrealized gain		69			40
Securities held-to-maturity, allowance for credit losses	[1]	0
Securities held-to-maturity, amortized cost		1,289
Securities held-to-maturity, amortized cost					1,418
Direct Agency Obligations U S Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available-for-sale, fair value		1,844			1,403
Securities available-for-sale, unrealized losses		(14)			0
Securities available-for-sale, unrealized gains		9			21
Securities available-for-sale, allowance for credit losses	[1]	0
Securities available-for-sale, amortized cost		1,849
Securities available-for-sale, amortized cost					1,382
Mortgage-backed Securities, Issued or Guaranteed by US Government Agency [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available-for-sale, fair value		10,488			9,997
Securities available-for-sale, unrealized losses		(2)			(41)
Securities available-for-sale, unrealized gains		276			29
Securities available-for-sale, allowance for credit losses	[1]	0
Securities available-for-sale, amortized cost		10,214
Securities available-for-sale, amortized cost					10,009
Securities held-to-maturity, fair value		2,895			3,021
Securities held-to-maturity, unrealized losses		0			0
Securities held-to-maturity, unrealized gain		90			17
Securities held-to-maturity, allowance for credit losses	[1]	0
Securities held-to-maturity, amortized cost		2,805
Securities held-to-maturity, amortized cost					3,004
Collateralized Mortgage Obligations, Issued or Guaranteed by US Government Agency [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available-for-sale, fair value		1,323			747
Securities available-for-sale, unrealized losses		(1)			(4)
Securities available-for-sale, unrealized gains		42			10
Securities available-for-sale, allowance for credit losses	[1]	0
Securities available-for-sale, amortized cost		1,282
Securities available-for-sale, amortized cost					741
Securities held-to-maturity, fair value		7,567			7,290
Securities held-to-maturity, unrealized losses		(4)			(22)
Securities held-to-maturity, unrealized gain		255			85
Securities held-to-maturity, allowance for credit losses	[1]	0
Securities held-to-maturity, amortized cost		7,316
Securities held-to-maturity, amortized cost					7,227
Direct Agency Obligations, Issued or Guaranteed by US Government Agency [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available-for-sale, fair value		279			260
Securities available-for-sale, unrealized losses		(11)			0
Securities available-for-sale, unrealized gains		0			6
Securities available-for-sale, allowance for credit losses	[1]	0
Securities available-for-sale, amortized cost		290
Securities available-for-sale, amortized cost					254
Obligations of U.S. states and political subdivision [Member]
Debt Securities, Available-for-sale [Line Items]
Securities held-to-maturity, fair value		10			11
Securities held-to-maturity, unrealized losses		0			0
Securities held-to-maturity, unrealized gain		1			1
Securities held-to-maturity, allowance for credit losses	[1]	(1)
Securities held-to-maturity, amortized cost		10
Securities held-to-maturity, amortized cost					10
Residential mortgage asset-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities held-to-maturity, fair value		2			2
Securities held-to-maturity, unrealized losses		0			0
Securities held-to-maturity, unrealized gain		1			0
Securities held-to-maturity, allowance for credit losses	[1]	(1)
Securities held-to-maturity, amortized cost		2
Securities held-to-maturity, amortized cost					2
Home Equity Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available-for-sale, fair value		28			32
Securities available-for-sale, unrealized losses		(2)			(2)
Securities available-for-sale, unrealized gains		0			0
Securities available-for-sale, allowance for credit losses	[1]	(2)
Securities available-for-sale, amortized cost		32
Securities available-for-sale, amortized cost					34
Other securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available-for-sale, fair value		116			111
Securities available-for-sale, unrealized losses		(3)			0
Securities available-for-sale, unrealized gains		3			3
Securities available-for-sale, allowance for credit losses	[1]	0
Securities available-for-sale, amortized cost		116
Securities available-for-sale, amortized cost					108
Foreign debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available-for-sale, fair value	[3]	4,231			3,286
Securities available-for-sale, unrealized losses	[3]	(7)			0
Securities available-for-sale, unrealized gains	[3]	6			4
Securities available-for-sale, allowance for credit losses	[1]	0
Securities available-for-sale, amortized cost	[3]	$ 4,232
Securities available-for-sale, amortized cost	[3]				$ 3,282
[1]	As discussed in Note 21, "New Accounting Pronouncements," beginning January 1, 2020, an allowance for credit losses is recognized for debt securities while, prior to January 1, 2020, debt securities were assessed for other-than-temporary impairment. At December 31, 2019, we did not consider any of our debt securities to be other-than-temporarily impaired
[2]	See Note 4, "Securities," for additional information regarding the allowance for credit losses associated with our security portfolios.
[3]	Foreign debt securities represent public sector entity, bank or corporate debt.

Securities - Gross unrealized l

Securities - Gross unrealized losses and related fair values (Detail) $ in Millions	Mar. 31, 2020USD ($)security	Dec. 31, 2019USD ($)security
Debt Securities, Available-for-sale [Line Items]
Number of securities available for sale in one year or less | security	63	78
Securities available-for-sale gross unrealized losses one year or less	$ (123)	$ (73)
Securities available-for-sale aggregate fair value of investment one year or less	$ 7,598	$ 8,005
Number of Securities available for sale greater than one year | security	42	171
Securities available-for-sale gross unrealized losses greater than one year	$ (128)	$ (257)
Securities available-for-sale agregate fair value of investment greater than one year	$ 2,255	$ 8,467
Number of securities held-to-maturity in one year or less | security		62
Securities held-to-maturity gross unrealized losses one year or less		$ (3)
Securities held-to-maturity aggregate fair value of investment one year or less		$ 950
Number of securities held-to-maturity greater than one year | security		351
Securities held-to-maturity gross unrealized losses greater than one year		$ (24)
Securities held-to-maturity aggregate fair value of investment greater than one year		$ 2,227
US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Number of securities available for sale in one year or less | security	23	22
Securities available-for-sale gross unrealized losses one year or less	$ (86)	$ (61)
Securities available-for-sale aggregate fair value of investment one year or less	$ 3,827	$ 4,034
Number of Securities available for sale greater than one year | security	16	28
Securities available-for-sale gross unrealized losses greater than one year	$ (123)	$ (208)
Securities available-for-sale agregate fair value of investment greater than one year	$ 1,640	$ 4,962
US Government-sponsored enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Number of securities available for sale in one year or less | security	10	18
Securities available-for-sale gross unrealized losses one year or less	$ (15)	$ (8)
Securities available-for-sale aggregate fair value of investment one year or less	$ 910	$ 772
Number of Securities available for sale greater than one year | security	10	83
Securities available-for-sale gross unrealized losses greater than one year	$ (1)	$ (6)
Securities available-for-sale agregate fair value of investment greater than one year	$ 95	$ 672
Number of securities held-to-maturity in one year or less | security		15
Securities held-to-maturity gross unrealized losses one year or less		$ 0
Securities held-to-maturity aggregate fair value of investment one year or less		$ 63
Number of securities held-to-maturity greater than one year | security		76
Securities held-to-maturity gross unrealized losses greater than one year		$ (5)
Securities held-to-maturity aggregate fair value of investment greater than one year		$ 522
US Government agency issued or guaranteed [Member]
Debt Securities, Available-for-sale [Line Items]
Number of securities available for sale in one year or less | security	5	27
Securities available-for-sale gross unrealized losses one year or less	$ (12)	$ (4)
Securities available-for-sale aggregate fair value of investment one year or less	$ 375	$ 1,961
Number of Securities available for sale greater than one year | security	7	50
Securities available-for-sale gross unrealized losses greater than one year	$ (2)	$ (41)
Securities available-for-sale agregate fair value of investment greater than one year	$ 251	$ 2,508
Number of securities held-to-maturity in one year or less | security		46
Securities held-to-maturity gross unrealized losses one year or less		$ (3)
Securities held-to-maturity aggregate fair value of investment one year or less		$ 887
Number of securities held-to-maturity greater than one year | security		274
Securities held-to-maturity gross unrealized losses greater than one year		$ (19)
Securities held-to-maturity aggregate fair value of investment greater than one year		$ 1,705
Asset-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Number of securities available for sale in one year or less | security	1	0
Securities available-for-sale gross unrealized losses one year or less	$ (3)	$ 0
Securities available-for-sale aggregate fair value of investment one year or less	$ 59	$ 0
Number of Securities available for sale greater than one year | security	4	5
Securities available-for-sale gross unrealized losses greater than one year	$ (2)	$ (2)
Securities available-for-sale agregate fair value of investment greater than one year	$ 28	$ 33
Foreign debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Number of securities available for sale in one year or less | security	24	11
Securities available-for-sale gross unrealized losses one year or less	$ (7)	$ 0
Securities available-for-sale aggregate fair value of investment one year or less	$ 2,427	$ 1,238
Number of Securities available for sale greater than one year | security	5	5
Securities available-for-sale gross unrealized losses greater than one year	$ 0	$ 0
Securities available-for-sale agregate fair value of investment greater than one year	$ 241	$ 292
Obligations of U.S. states and political subdivision [Member]
Debt Securities, Available-for-sale [Line Items]
Number of securities held-to-maturity in one year or less | security		1
Securities held-to-maturity gross unrealized losses one year or less		$ 0
Securities held-to-maturity aggregate fair value of investment one year or less		$ 0
Number of securities held-to-maturity greater than one year | security		1
Securities held-to-maturity gross unrealized losses greater than one year		$ 0
Securities held-to-maturity aggregate fair value of investment greater than one year		$ 0

Securities Securities - Credit

Securities Securities - Credit Risk Profile of Held-to-maturity Securities (Details) $ in Millions	Mar. 31, 2020USD ($)
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	$ 12,983
Investment Grade [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	12,983
Non-Investment Grade [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	0
US Government-sponsored enterprises [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	2,850
US Government-sponsored enterprises [Member] | Investment Grade [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	2,850
US Government-sponsored enterprises [Member] | Non-Investment Grade [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	0
US Government agency issued or guaranteed [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	10,121
US Government agency issued or guaranteed [Member] | Investment Grade [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	10,121
US Government agency issued or guaranteed [Member] | Non-Investment Grade [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	0
Obligations of U.S. states and political subdivision [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	10
Obligations of U.S. states and political subdivision [Member] | Investment Grade [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	10
Obligations of U.S. states and political subdivision [Member] | Non-Investment Grade [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	0
Asset-backed securities collateralized by residential mortgages [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	2
Asset-backed securities collateralized by residential mortgages [Member] | Investment Grade [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	2
Asset-backed securities collateralized by residential mortgages [Member] | Non-Investment Grade [Member]
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Securities held-to-maturity	$ 0

Securities - Realized gains and

Securities - Realized gains and losses on investment securities Transactions Attributable to available-for-sale securities (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Gross realized gains	$ 51	$ 16
Gross realized losses	(23)	(9)
Net realized gains	$ 28	$ 7

Securities - Distribution of ma

Securities - Distribution of maturities of debt securities with approximate yield of portfolio (Detail) $ in Millions	Mar. 31, 2020USD ($)
Debt Securities, Available-for-sale [Line Items]
Available-for-sale amount within one year	$ 3,027
Available-for-sale yield within one year	1.15%
Available-for-sale amount after one but within five years	$ 7,894
Available-for-sale yield after one but within five years	1.39%
Available-for-sale amount after five but within ten years	$ 8,690
Available-for-sale yield after five but within ten years	1.93%
Available-for-sale amount after ten years	$ 20,256
Available-for-sale yield after ten years	2.14%
Total fair value within one year	$ 3,031
Total fair value after one but within five years	7,997
Total fair value after five but within ten years	9,176
Total fair value after ten years	20,588
Held-to-maturity amount within one year	$ 0
Held-to-maturity yield within one year	0.00%
Held-to-maturity amount after one but within five years	$ 498
Held-to-maturity yield after one but within five years	2.70%
Held-to-maturity after five but within ten years	$ 592
Held-to-maturity yield after five but within ten years	2.34%
Held-to-maturity after ten years	$ 11,893
Held-to-maturity yield after ten years	2.67%
Total fair value within one year	$ 0
Total fair value after one but within five years	512
Total fair value after five but within ten years	607
Total fair value after ten years	12,327
U.S. Treasury [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale amount within one year	$ 55
Available-for-sale yield within one year	2.93%
Available-for-sale amount after one but within five years	$ 5,308
Available-for-sale yield after one but within five years	1.27%
Available-for-sale amount after five but within ten years	$ 6,201
Available-for-sale yield after five but within ten years	1.61%
Available-for-sale amount after ten years	$ 5,329
Available-for-sale yield after ten years	2.10%
US Government-sponsored enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale amount within one year	$ 730
Available-for-sale yield within one year	2.82%
Available-for-sale amount after one but within five years	$ 516
Available-for-sale yield after one but within five years	1.90%
Available-for-sale amount after five but within ten years	$ 2,426
Available-for-sale yield after five but within ten years	2.66%
Available-for-sale amount after ten years	$ 3,136
Available-for-sale yield after ten years	2.55%
Held-to-maturity amount within one year	$ 0
Held-to-maturity yield within one year	0.00%
Held-to-maturity amount after one but within five years	$ 480
Held-to-maturity yield after one but within five years	2.66%
Held-to-maturity after five but within ten years	$ 568
Held-to-maturity yield after five but within ten years	2.26%
Held-to-maturity after ten years	$ 1,802
Held-to-maturity yield after ten years	3.19%
US Government agency issued or guaranteed [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale amount within one year	$ 0
Available-for-sale yield within one year	0.00%
Available-for-sale amount after one but within five years	$ 80
Available-for-sale yield after one but within five years	2.12%
Available-for-sale amount after five but within ten years	$ 1
Available-for-sale yield after five but within ten years	7.88%
Available-for-sale amount after ten years	$ 11,705
Available-for-sale yield after ten years	2.03%
Held-to-maturity amount within one year	$ 0
Held-to-maturity yield within one year	0.00%
Held-to-maturity amount after one but within five years	$ 12
Held-to-maturity yield after one but within five years	3.92%
Held-to-maturity after five but within ten years	$ 20
Held-to-maturity yield after five but within ten years	4.18%
Held-to-maturity after ten years	$ 10,089
Held-to-maturity yield after ten years	2.57%
Obligations of U.S. states and political subdivision [Member]
Debt Securities, Available-for-sale [Line Items]
Held-to-maturity amount within one year	$ 0
Held-to-maturity yield within one year	0.00%
Held-to-maturity amount after one but within five years	$ 6
Held-to-maturity yield after one but within five years	3.58%
Held-to-maturity after five but within ten years	$ 4
Held-to-maturity yield after five but within ten years	4.16%
Held-to-maturity after ten years	$ 0
Held-to-maturity yield after ten years	0.00%
Asset-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale amount within one year	$ 0
Available-for-sale yield within one year	0.00%
Available-for-sale amount after one but within five years	$ 0
Available-for-sale yield after one but within five years	0.00%
Available-for-sale amount after five but within ten years	$ 62
Available-for-sale yield after five but within ten years	4.85%
Available-for-sale amount after ten years	$ 86
Available-for-sale yield after ten years	3.19%
Held-to-maturity amount within one year	$ 0
Held-to-maturity yield within one year	0.00%
Held-to-maturity amount after one but within five years	$ 0
Held-to-maturity yield after one but within five years	0.00%
Held-to-maturity after five but within ten years	$ 0
Held-to-maturity yield after five but within ten years	0.00%
Held-to-maturity after ten years	$ 2
Held-to-maturity yield after ten years	6.02%
Foreign debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale amount within one year	$ 2,242
Available-for-sale yield within one year	0.56%
Available-for-sale amount after one but within five years	$ 1,990
Available-for-sale yield after one but within five years	1.52%
Available-for-sale amount after five but within ten years	$ 0
Available-for-sale yield after five but within ten years	0.00%
Available-for-sale amount after ten years	$ 0
Available-for-sale yield after ten years	0.00%

Securities - Additional Informa

Securities - Additional Information (Detail) - USD ($)		Mar. 31, 2020		Jan. 01, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Securities available-for-sale, allowance for credit losses	[2]	$ 2,000,000	[1]	$ 3,000,000
Securities held-to-maturity, allowance for credit losses	[2]	2,000,000	[1]	2,000,000
Securities held-to-maturity, past due		0		0
Securities held-to-maturity, nonaccrual		0		$ 0
Equity securities without readily determinable fair value, impairment loss		0			$ 0
Other assets [Member]
Debt Securities, Available-for-sale [Line Items]
Equity securities carried at fair value		278,000,000			283,000,000
Equity securities without readily determinable fair values		12,000,000			12,000,000
Federal Home Loan Bank Stock		324,000,000			110,000,000
Federal Reserve Bank Stock		$ 559,000,000			$ 559,000,000
[1]	As discussed in Note 21, "New Accounting Pronouncements," beginning January 1, 2020, an allowance for credit losses is recognized for debt securities while, prior to January 1, 2020, debt securities were assessed for other-than-temporary impairment. At December 31, 2019, we did not consider any of our debt securities to be other-than-temporarily impaired
[2]	See Note 4, "Securities," for additional information regarding the allowance for credit losses associated with our security portfolios.

Loans - Components of Loans (De

Loans - Components of Loans (Details) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 81,728	$ 68,553
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		61,246	48,211
Commercial Loans [Member] | Real Estate, Including Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		11,369	11,501
Commercial Loans [Member] | Business and Corporate Banking [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		19,620	13,479
Commercial Loans [Member] | Global Banking [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[1]	24,141	17,915
Commercial Loans [Member] | Other Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		6,116	5,316
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		20,482	20,342
Consumer Loans [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		18,034	17,801
Consumer Loans [Member] | Home Equity Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		814	853
Consumer Loans [Member] | Credit Cards [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		1,300	1,405
Consumer Loans [Member] | Other consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[2]	334	283
Consumer Loans [Member] | Student Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, designated under fair value option		37
Affiliated Entity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		3,087	2,343
Affiliated Entity [Member] | Other Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[3]		2,343
Affiliated Entity [Member] | Commercial Loans [Member] | Other Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[3]	3,087
Other [Member] | Commercial Loans [Member] | Other Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 3,029	$ 2,973
[1]	Represents large multinational firms including globally focused U.S. corporate and financial institutions, U.S. dollar lending to multinational banking clients managed by HSBC on a global basis and complex large business clients supported by Global Banking and Markets relationship managers.
[2]	Includes certain student loans that we have elected to designate under the fair value option and are therefore carried at fair value, which totaled $37 million at March 31, 2020. See Note 10, "Fair Value Option," for further details.
[3]	See Note 14, "Related Party Transactions," for additional information regarding loans to HSBC affiliates.

Loans - Additional Information

Loans - Additional Information (Detail) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Receivables [Abstract]
Net deferred origination costs (fees)	$ 76	$ 79
Net unamortized premium (discount)	$ 9	$ 3

Loans - Summary of Past Due Sta

Loans - Summary of Past Due Status of Loans (Detail) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		$ 873	$ 831
Current	[1]	80,855	67,722
Total loans		81,728	68,553
Commercial Loans [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		150	125
Current	[1]	61,096	48,086
Total loans		61,246	48,211
Commercial Loans [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		6	8
Current	[1]	11,363	11,493
Total loans		11,369	11,501
Commercial Loans [Member] | Business and Corporate Banking [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		112	95
Current	[1]	19,508	13,384
Total loans		19,620	13,479
Commercial Loans [Member] | Global Banking [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		0	0
Current	[1]	24,141	17,915
Total loans	[2]	24,141	17,915
Commercial Loans [Member] | Other Commercial [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		32	22
Current	[1]	6,084	5,294
Total loans		6,116	5,316
Consumer Loans [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		723	706
Current	[1]	19,759	19,636
Total loans		20,482	20,342
Consumer Loans [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		625	614
Current	[1]	17,409	17,187
Total loans		18,034	17,801
Consumer Loans [Member] | Home Equity Mortgages [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		33	34
Current	[1]	781	819
Total loans		814	853
Consumer Loans [Member] | Credit Cards [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		53	48
Current	[1]	1,247	1,357
Total loans		1,300	1,405
Consumer Loans [Member] | Other consumer [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		12	10
Current	[1]	322	273
Total loans	[3]	334	283
Financing Receivables, 30 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		548	470
Financing Receivables, 30 to 89 Days Past Due [Member] | Commercial Loans [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		140	89
Financing Receivables, 30 to 89 Days Past Due [Member] | Commercial Loans [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		4	7
Financing Receivables, 30 to 89 Days Past Due [Member] | Commercial Loans [Member] | Business and Corporate Banking [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		104	60
Financing Receivables, 30 to 89 Days Past Due [Member] | Commercial Loans [Member] | Global Banking [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		0	0
Financing Receivables, 30 to 89 Days Past Due [Member] | Commercial Loans [Member] | Other Commercial [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		32	22
Financing Receivables, 30 to 89 Days Past Due [Member] | Consumer Loans [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		408	381
Financing Receivables, 30 to 89 Days Past Due [Member] | Consumer Loans [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		366	342
Financing Receivables, 30 to 89 Days Past Due [Member] | Consumer Loans [Member] | Home Equity Mortgages [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		10	10
Financing Receivables, 30 to 89 Days Past Due [Member] | Consumer Loans [Member] | Credit Cards [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		25	24
Financing Receivables, 30 to 89 Days Past Due [Member] | Consumer Loans [Member] | Other consumer [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		7	5
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		325	361
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Loans [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		10	36
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Loans [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		2	1
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Loans [Member] | Business and Corporate Banking [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		8	35
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Loans [Member] | Global Banking [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Loans [Member] | Other Commercial [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Loans [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		315	325
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Loans [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		259	272
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Loans [Member] | Home Equity Mortgages [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		23	24
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Loans [Member] | Credit Cards [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		28	24
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Loans [Member] | Other consumer [Member]
Financing Receivable, Past Due [Line Items]
Total Days Past Due, 30 Days or More		$ 5	$ 5
[1]	Loans less than 30 days past due are presented as current.
[2]	Represents large multinational firms including globally focused U.S. corporate and financial institutions, U.S. dollar lending to multinational banking clients managed by HSBC on a global basis and complex large business clients supported by Global Banking and Markets relationship managers.
[3]	Includes certain student loans that we have elected to designate under the fair value option and are therefore carried at fair value, which totaled $37 million at March 31, 2020. See Note 10, "Fair Value Option," for further details.

Loans - Summary of Nonaccrual L

Loans - Summary of Nonaccrual Loans and Accruing Receivables 90 Days or More Delinquent (Detail) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans		$ 663	$ 664
Accruing Loans Contractually Past Due 90 days or More		32	30
Nonaccrual Loans With No Allowance For Credit Losses		334	428
Residential mortgage loans carried at lower of cost or fair value of the collateral less cost to sell		286	289
Commercial Loans [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans		255	237
Accruing Loans Contractually Past Due 90 days or More		2	1
Nonaccrual Loans With No Allowance For Credit Losses		132	139
Commercial Loans [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans		5	6
Accruing Loans Contractually Past Due 90 days or More		0	0
Nonaccrual Loans With No Allowance For Credit Losses		3	3
Commercial Loans [Member] | Business and Corporate Banking [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans		112	82
Accruing Loans Contractually Past Due 90 days or More		2	1
Nonaccrual Loans With No Allowance For Credit Losses		2	19
Commercial Loans [Member] | Global Banking [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans		138	149
Accruing Loans Contractually Past Due 90 days or More		0	0
Nonaccrual Loans With No Allowance For Credit Losses		127	117
Consumer Loans [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans		408	427
Accruing Loans Contractually Past Due 90 days or More		30	29
Nonaccrual Loans With No Allowance For Credit Losses		202	289
Consumer Loans [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans	[1],[2],[3]	370	381
Accruing Loans Contractually Past Due 90 days or More	[1],[2],[3]	0	0
Nonaccrual Loans With No Allowance For Credit Losses	[1],[2],[3]	171	257
Consumer Loans [Member] | Home Equity Mortgages [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans	[1],[3]	38	46
Accruing Loans Contractually Past Due 90 days or More	[1],[3]	0	0
Nonaccrual Loans With No Allowance For Credit Losses	[1],[3]	31	32
Consumer Loans [Member] | Credit Cards [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans		0	0
Accruing Loans Contractually Past Due 90 days or More		28	24
Nonaccrual Loans With No Allowance For Credit Losses		0	0
Consumer Loans [Member] | Other consumer [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans		0	0
Accruing Loans Contractually Past Due 90 days or More		2	5
Nonaccrual Loans With No Allowance For Credit Losses		$ 0	$ 0
[1]	At March 31, 2020 and December 31, 2019, nonaccrual consumer mortgage loans include $286 million and $289 million, respectively, of loans that are carried at the lower of amortized cost or fair value of the collateral less cost to sell. The decrease in nonaccrual consumer mortgage loans with no allowance for credit losses at March 31, 2020 reflects the impact of adopting new accounting guidance which requires expected recoveries related to subsequent increases in the fair value of collateral for collateral-dependent loans to be recognized in the allowance for credit losses beginning January 1, 2020. See Note 21, "New Accounting Pronouncements," for additional discussion.
[2]	Nonaccrual consumer mortgage loans for all periods does not include guaranteed loans purchased from the Government National Mortgage Association. Repayment of these loans is predominantly insured by the Federal Housing Administration and as such, these loans have different risk characteristics from the rest of our consumer loan portfolio.
[3]	Nonaccrual consumer mortgage loans include all loans which are 90 or more days contractually delinquent as well as loans discharged under Chapter 7 bankruptcy and not re-affirmed and second lien loans where the first lien loan that we own or service is 90 or more days contractually delinquent.

Loans - Schedule of Additional

Loans - Schedule of Additional Information on Nonaccrual Loans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Receivables [Abstract]
Interest income that would have been recorded if the nonaccrual receivable had been current in accordance with contractual terms during the period	$ 8	$ 9
Interest income that was recorded on nonaccrual loans and included in interest income during the period	$ 7	$ 3

Loans Loans - Collateral-Depend

Loans Loans - Collateral-Dependent Loans (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Consumer Loans [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateral-dependent loans	$ 802	$ 803
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateral-dependent loans	$ 252	$ 227

Loans - Summary of TDRs (Detail

Loans - Summary of TDRs (Detail) - USD ($)		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Anticipatory TDRs		$ 0
Commercial loans removed from TDR classification		0	$ 0
TDR Loans	[1]	698,000,000		$ 720,000,000
Residential mortgage loan TDR carried at lower of amortized cost or fair value less cost to sell		508,000,000		557,000,000
Non Accrual loans included in TDR loan		318,000,000		230,000,000
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDR Loans	[2]	101,000,000		104,000,000
Additional commitments to lend to commercial borrowers with modified TDRs		143,000,000		222,000,000
Commercial Loans [Member] | Business and Corporate Banking [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDR Loans		32,000,000		36,000,000
Commercial Loans [Member] | Global Banking [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDR Loans		69,000,000		68,000,000
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDR Loans		597,000,000		616,000,000
Consumer Loans [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDR Loans	[3]	561,000,000		580,000,000
Consumer Loans [Member] | Home Equity Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDR Loans	[3]	32,000,000		32,000,000
Consumer Loans [Member] | Credit Cards [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDR Loans		$ 4,000,000		$ 4,000,000
[1]	At March 31, 2020 and December 31, 2019, the carrying value of TDR Loans includes $318 million and $230 million, respectively, of loans which are classified as nonaccrual.
[2]	Additional commitments to lend to commercial borrowers whose loans have been modified in TDR Loans totaled $143 million and $222 million at March 31, 2020 and December 31, 2019, respectively.
[3]	At March 31, 2020 and December 31, 2019, the carrying value of consumer mortgage TDR Loans includes $508 million and $557 million, respectively, of loans that are recorded at the lower of amortized cost or fair value of the collateral less cost to sell.

Loans - Summary of Receivables

Loans - Summary of Receivables which were Modified and as Result Became Classified as TDR Loans (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	$ 18	$ 2
Commercial Loan [Member]
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	12	0
Commercial Loan [Member] | Global Banking [Member]
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	12	0
Consumer Loans [Member]
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	$ 6	$ 2
Weighted average rate of reduction	3.04%	1.24%
Consumer Loans [Member] | Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	$ 4	$ 1
Consumer Loans [Member] | Home Equity Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	1	0
Consumer Loans [Member] | Credit Cards [Member]
Financing Receivable, Impaired [Line Items]
Loans which were modified and as a result became classified as TDR Loans	$ 1	$ 1

Loans - Loans Classified as TDR

Loans - Loans Classified as TDR Loans (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Commercial Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Threshold period for troubled debt restructuring status	90 days	90 days
Loans which were classified as TDR loans during previous 12 months which became contractually delinquent	$ 0	$ 0
Consumer Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Threshold period for troubled debt restructuring status	60 days	60 days
Loans which were classified as TDR loans during previous 12 months which became contractually delinquent	$ 1	$ 2
Consumer Loans [Member] | Residential Mortgage [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans which were classified as TDR loans during previous 12 months which became contractually delinquent	$ 1	$ 2

Loans - Summary of Criticized A

Loans - Summary of Criticized Assets for Commercial Loans (Detail) - Commercial Loans [Member] - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 1,539
2019	7,634
2018	5,784
2017	2,831
2016	1,607
Prior	10,436
Revolving Loans	31,041
Revolving Loans Converted to Term Loans	374
Total loans	61,246	$ 48,211
Real Estate, Including Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	405
2019	3,800
2018	3,095
2017	1,389
2016	336
Prior	2,171
Revolving Loans	147
Revolving Loans Converted to Term Loans	26
Total loans	11,369	11,501
Business and Corporate Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	619
2019	1,525
2018	853
2017	415
2016	540
Prior	3,444
Revolving Loans	11,876
Revolving Loans Converted to Term Loans	348
Total loans	19,620	13,479
Global Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	378
2019	1,832
2018	1,501
2017	842
2016	583
Prior	4,437
Revolving Loans	14,568
Revolving Loans Converted to Term Loans	0
Total loans	24,141	17,915
Other Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	137
2019	477
2018	335
2017	185
2016	148
Prior	384
Revolving Loans	4,450
Revolving Loans Converted to Term Loans	0
Total loans	6,116	5,316
Criticized [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	664
2018	226
2017	196
2016	18
Prior	803
Revolving Loans	1,651
Revolving Loans Converted to Term Loans	28
Total loans	3,586	2,001
Criticized [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	532
2018	157
2017	122
2016	0
Prior	279
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total loans	1,090	719
Criticized [Member] | Business and Corporate Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	70
2018	58
2017	74
2016	15
Prior	303
Revolving Loans	986
Revolving Loans Converted to Term Loans	28
Total loans	1,534	876
Criticized [Member] | Global Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	38
2018	0
2017	0
2016	0
Prior	201
Revolving Loans	604
Revolving Loans Converted to Term Loans	0
Total loans	843	395
Criticized [Member] | Other Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	24
2018	11
2017	0
2016	3
Prior	20
Revolving Loans	61
Revolving Loans Converted to Term Loans	0
Total loans	119	11
Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	489
2018	182
2017	172
2016	16
Prior	520
Revolving Loans	889
Revolving Loans Converted to Term Loans	24
Total loans	2,292	1,178
Special Mention [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	402
2018	150
2017	122
2016	0
Prior	234
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total loans	908	516
Special Mention [Member] | Business and Corporate Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	25
2018	21
2017	50
2016	13
Prior	164
Revolving Loans	555
Revolving Loans Converted to Term Loans	24
Total loans	852	467
Special Mention [Member] | Global Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	38
2018	0
2017	0
2016	0
Prior	102
Revolving Loans	334
Revolving Loans Converted to Term Loans	0
Total loans	474	184
Special Mention [Member] | Other Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	24
2018	11
2017	0
2016	3
Prior	20
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total loans	58	11
Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	159
2018	31
2017	24
2016	2
Prior	252
Revolving Loans	698
Revolving Loans Converted to Term Loans	2
Total loans	1,168	785
Substandard [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	130
2018	7
2017	0
2016	0
Prior	45
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total loans	182	203
Substandard [Member] | Business and Corporate Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	29
2018	24
2017	24
2016	2
Prior	121
Revolving Loans	367
Revolving Loans Converted to Term Loans	2
Total loans	569	386
Substandard [Member] | Global Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	86
Revolving Loans	270
Revolving Loans Converted to Term Loans	0
Total loans	356	196
Substandard [Member] | Other Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	61
Revolving Loans Converted to Term Loans	0
Total loans	61	0
Doubtful [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	16
2018	13
2017	0
2016	0
Prior	31
Revolving Loans	64
Revolving Loans Converted to Term Loans	2
Total loans	126	38
Doubtful [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total loans	0	0
Doubtful [Member] | Business and Corporate Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	16
2018	13
2017	0
2016	0
Prior	18
Revolving Loans	64
Revolving Loans Converted to Term Loans	2
Total loans	113	23
Doubtful [Member] | Global Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	13
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total loans	13	15
Doubtful [Member] | Other Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total loans	$ 0	$ 0

Loans - Status of Loan Portfoli

Loans - Status of Loan Portfolios (Detail) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Commercial Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 1,539
2019	7,634
2018	5,784
2017	2,831
2016	1,607
Prior	10,436
Revolving Loans	31,041
Revolving Loans Converted to Term Loans	374
Total loans	61,246	$ 48,211
Commercial Loans [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	405
2019	3,800
2018	3,095
2017	1,389
2016	336
Prior	2,171
Revolving Loans	147
Revolving Loans Converted to Term Loans	26
Total loans	11,369	11,501
Commercial Loans [Member] | Business and Corporate Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	619
2019	1,525
2018	853
2017	415
2016	540
Prior	3,444
Revolving Loans	11,876
Revolving Loans Converted to Term Loans	348
Total loans	19,620	13,479
Commercial Loans [Member] | Global Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	378
2019	1,832
2018	1,501
2017	842
2016	583
Prior	4,437
Revolving Loans	14,568
Revolving Loans Converted to Term Loans	0
Total loans	24,141	17,915
Commercial Loans [Member] | Other Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	137
2019	477
2018	335
2017	185
2016	148
Prior	384
Revolving Loans	4,450
Revolving Loans Converted to Term Loans	0
Total loans	6,116	5,316
Commercial Loans [Member] | Performing Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,539
2019	7,618
2018	5,771
2017	2,831
2016	1,587
Prior	10,367
Revolving Loans	30,905
Revolving Loans Converted to Term Loans	371
Total loans	60,989	47,973
Commercial Loans [Member] | Performing Loans [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	405
2019	3,800
2018	3,095
2017	1,389
2016	335
Prior	2,169
Revolving Loans	147
Revolving Loans Converted to Term Loans	24
Total loans	11,364	11,495
Commercial Loans [Member] | Performing Loans [Member] | Business and Corporate Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	619
2019	1,509
2018	840
2017	415
2016	540
Prior	3,428
Revolving Loans	11,808
Revolving Loans Converted to Term Loans	347
Total loans	19,506	13,396
Commercial Loans [Member] | Performing Loans [Member] | Global Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	378
2019	1,832
2018	1,501
2017	842
2016	564
Prior	4,386
Revolving Loans	14,500
Revolving Loans Converted to Term Loans	0
Total loans	24,003	17,766
Commercial Loans [Member] | Performing Loans [Member] | Other Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	137
2019	477
2018	335
2017	185
2016	148
Prior	384
Revolving Loans	4,450
Revolving Loans Converted to Term Loans	0
Total loans	6,116	5,316
Commercial Loans [Member] | Nonaccrual Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	16
2018	13
2017	0
2016	20
Prior	69
Revolving Loans	134
Revolving Loans Converted to Term Loans	3
Total loans	255	237
Commercial Loans [Member] | Nonaccrual Loans [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017
2016	1
Prior	2
Revolving Loans	0
Revolving Loans Converted to Term Loans	2
Total loans	5	6
Commercial Loans [Member] | Nonaccrual Loans [Member] | Business and Corporate Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	16
2018	13
2017	0
2016	0
Prior	16
Revolving Loans	66
Revolving Loans Converted to Term Loans	1
Total loans	112	82
Commercial Loans [Member] | Nonaccrual Loans [Member] | Global Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	19
Prior	51
Revolving Loans	68
Revolving Loans Converted to Term Loans	0
Total loans	138	149
Commercial Loans [Member] | Nonaccrual Loans [Member] | Other Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total loans	0	0
Commercial Loans [Member] | Nonperforming Loans, Accruing Loans 90 Days or More Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	2
Revolving Loans Converted to Term Loans	0
Total loans	2	1
Commercial Loans [Member] | Nonperforming Loans, Accruing Loans 90 Days or More Past Due [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total loans	0	0
Commercial Loans [Member] | Nonperforming Loans, Accruing Loans 90 Days or More Past Due [Member] | Business and Corporate Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	2
Revolving Loans Converted to Term Loans	0
Total loans	2	1
Commercial Loans [Member] | Nonperforming Loans, Accruing Loans 90 Days or More Past Due [Member] | Global Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total loans	0	0
Commercial Loans [Member] | Nonperforming Loans, Accruing Loans 90 Days or More Past Due [Member] | Other Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total loans	0	0
Consumer Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,087
2019	3,093
2018	1,850
2017	2,105
2016	2,428
Prior	8,521
Revolving Loans	1,398
Total loans	20,482	20,342
Consumer Loans [Member] | Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,032
2019	2,976
2018	1,805
2017	2,062
2016	2,371
Prior	7,788
Revolving Loans	0
Total loans	18,034	17,801
Consumer Loans [Member] | Home Equity Mortgages [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	14
2019	54
2018	44
2017	41
2016	53
Prior	608
Revolving Loans	0
Total loans	814	853
Consumer Loans [Member] | Credit Cards [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	1,300
Total loans	1,300	1,405
Consumer Loans [Member] | Other consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	41
2019	63
2018	1
2017	2
2016	4
Prior	125
Revolving Loans	98
Total loans	334	283
Consumer Loans [Member] | Performing Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,087
2019	3,085
2018	1,844
2017	2,092
2016	2,416
Prior	8,152
Revolving Loans	1,368
Total loans	20,044	19,886
Consumer Loans [Member] | Performing Loans [Member] | Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,032
2019	2,968
2018	1,799
2017	2,049
2016	2,359
Prior	7,457
Revolving Loans	0
Total loans	17,664	17,420
Consumer Loans [Member] | Performing Loans [Member] | Home Equity Mortgages [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	14
2019	54
2018	44
2017	41
2016	53
Prior	570
Revolving Loans	0
Total loans	776	807
Consumer Loans [Member] | Performing Loans [Member] | Credit Cards [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	1,272
Total loans	1,272	1,381
Consumer Loans [Member] | Performing Loans [Member] | Other consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	41
2019	63
2018	1
2017	2
2016	4
Prior	125
Revolving Loans	96
Total loans	332	278
Consumer Loans [Member] | Nonaccrual Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	8
2018	6
2017	13
2016	12
Prior	369
Revolving Loans	0
Total loans	408	427
Consumer Loans [Member] | Nonaccrual Loans [Member] | Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	8
2018	6
2017	13
2016	12
Prior	331
Revolving Loans	0
Total loans	370	381
Consumer Loans [Member] | Nonaccrual Loans [Member] | Home Equity Mortgages [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	38
Revolving Loans	0
Total loans	38	46
Consumer Loans [Member] | Nonperforming Loans, Accruing Loans 90 Days or More Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	30
Total loans	30	29
Consumer Loans [Member] | Nonperforming Loans, Accruing Loans 90 Days or More Past Due [Member] | Credit Cards [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	28
Total loans	28	24
Consumer Loans [Member] | Nonperforming Loans, Accruing Loans 90 Days or More Past Due [Member] | Other consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	2
Total loans	$ 2	$ 5

Loans - Credit Risk Profile of

Loans - Credit Risk Profile of Commercial Loans (Detail) - Commercial Loans [Member] - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 1,539
2019	7,634
2018	5,784
2017	2,831
2016	1,607
Prior	10,436
Revolving Loans	31,041
Revolving Loans Converted to Term Loans	374
Total loans	61,246	$ 48,211
Real Estate, Including Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	405
2019	3,800
2018	3,095
2017	1,389
2016	336
Prior	2,171
Revolving Loans	147
Revolving Loans Converted to Term Loans	26
Total loans	11,369	11,501
Business and Corporate Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	619
2019	1,525
2018	853
2017	415
2016	540
Prior	3,444
Revolving Loans	11,876
Revolving Loans Converted to Term Loans	348
Total loans	19,620	13,479
Global Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	378
2019	1,832
2018	1,501
2017	842
2016	583
Prior	4,437
Revolving Loans	14,568
Revolving Loans Converted to Term Loans	0
Total loans	24,141	17,915
Other Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	137
2019	477
2018	335
2017	185
2016	148
Prior	384
Revolving Loans	4,450
Revolving Loans Converted to Term Loans	0
Total loans	6,116	5,316
Investment Grade [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,141
2019	3,797
2018	2,962
2017	1,584
2016	828
Prior	6,548
Revolving Loans	19,828
Revolving Loans Converted to Term Loans	91
Total loans	36,779	29,991
Investment Grade [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	287
2019	1,392
2018	1,500
2017	515
2016	202
Prior	1,205
Revolving Loans	6
Revolving Loans Converted to Term Loans	4
Total loans	5,111	6,332
Investment Grade [Member] | Business and Corporate Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	459
2019	611
2018	202
2017	104
2016	389
Prior	1,744
Revolving Loans	5,219
Revolving Loans Converted to Term Loans	87
Total loans	8,815	6,029
Investment Grade [Member] | Global Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	319
2019	1,363
2018	1,013
2017	802
2016	141
Prior	3,299
Revolving Loans	10,386
Revolving Loans Converted to Term Loans	0
Total loans	17,323	12,981
Investment Grade [Member] | Other Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	76
2019	431
2018	247
2017	163
2016	96
Prior	300
Revolving Loans	4,217
Revolving Loans Converted to Term Loans	0
Total loans	5,530	4,649
Noninvestment Grade [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	398
2019	3,837
2018	2,822
2017	1,247
2016	779
Prior	3,888
Revolving Loans	11,213
Revolving Loans Converted to Term Loans	283
Total loans	24,467	18,220
Noninvestment Grade [Member] | Real Estate, Including Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	118
2019	2,408
2018	1,595
2017	874
2016	134
Prior	966
Revolving Loans	141
Revolving Loans Converted to Term Loans	22
Total loans	6,258	5,169
Noninvestment Grade [Member] | Business and Corporate Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	160
2019	914
2018	651
2017	311
2016	151
Prior	1,700
Revolving Loans	6,657
Revolving Loans Converted to Term Loans	261
Total loans	10,805	7,450
Noninvestment Grade [Member] | Global Banking [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	59
2019	469
2018	488
2017	40
2016	442
Prior	1,138
Revolving Loans	4,182
Revolving Loans Converted to Term Loans	0
Total loans	6,818	4,934
Noninvestment Grade [Member] | Other Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	61
2019	46
2018	88
2017	22
2016	52
Prior	84
Revolving Loans	233
Revolving Loans Converted to Term Loans	0
Total loans	$ 586	$ 667

Loans - Delinquency Ratio for C

Loans - Delinquency Ratio for Consumer Loan (Detail) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Residential Mortgage Loan Delinquency Carried At Lower Of Amortized Cost Or Fair Value Less Cost To Sell	$ 249	$ 256
Consumer Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,087
2019	3,093
2018	1,850
2017	2,105
2016	2,428
Prior	8,521
Revolving Loans	1,398
Total loans	20,482	20,342
Mortgage Loans in Process of Foreclosure, Amount	135	142
Consumer Loans [Member] | Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,032
2019	2,976
2018	1,805
2017	2,062
2016	2,371
Prior	7,788
Revolving Loans	0
Total loans	18,034	17,801
Consumer Loans [Member] | Home Equity Mortgages [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	14
2019	54
2018	44
2017	41
2016	53
Prior	608
Revolving Loans	0
Total loans	814	853
Consumer Loans [Member] | Credit Cards [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	1,300
Total loans	1,300	1,405
Consumer Loans [Member] | Other consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	41
2019	63
2018	1
2017	2
2016	4
Prior	125
Revolving Loans	98
Total loans	334	283
Consumer Loans [Member] | Contractual Delinquency, 60 Days or More Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	12
2018	10
2017	15
2016	13
Prior	345
Revolving Loans	41
Total loans	436	416
Consumer Loans [Member] | Contractual Delinquency, 60 Days or More Past Due [Member] | Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	11
2018	10
2017	15
2016	13
Prior	315
Revolving Loans	0
Total loans	364	350
Consumer Loans [Member] | Contractual Delinquency, 60 Days or More Past Due [Member] | Home Equity Mortgages [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	26
Revolving Loans	0
Total loans	26	25
Consumer Loans [Member] | Contractual Delinquency, 60 Days or More Past Due [Member] | Credit Cards [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	39
Total loans	39	34
Consumer Loans [Member] | Contractual Delinquency, 60 Days or More Past Due [Member] | Other consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	1
2018	0
2017	0
2016	0
Prior	4
Revolving Loans	2
Total loans	$ 7	$ 7

Loans - Summary of TDRs in Cons

Loans - Summary of TDRs in Consumer Portfolio (Detail) - Consumer Loans [Member] - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Impaired [Line Items]
2020	$ 1,087
2019	3,093
2018	1,850
2017	2,105
2016	2,428
Prior	8,521
Revolving Loans	1,398
Total loans	20,482	$ 20,342
Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
2020	1,032
2019	2,976
2018	1,805
2017	2,062
2016	2,371
Prior	7,788
Revolving Loans	0
Total loans	18,034	17,801
Home Equity Mortgages [Member]
Financing Receivable, Impaired [Line Items]
2020	14
2019	54
2018	44
2017	41
2016	53
Prior	608
Revolving Loans	0
Total loans	814	853
Credit Cards [Member]
Financing Receivable, Impaired [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	1,300
Total loans	1,300	1,405
Troubled Debt Restructuring [Member]
Financing Receivable, Impaired [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	1
Prior	592
Revolving Loans	4
Total loans	597	616
Troubled Debt Restructuring [Member] | Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	1
Prior	560
Revolving Loans	0
Total loans	561	580
Troubled Debt Restructuring [Member] | Home Equity Mortgages [Member]
Financing Receivable, Impaired [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	32
Revolving Loans	0
Total loans	32	32
Troubled Debt Restructuring [Member] | Credit Cards [Member]
Financing Receivable, Impaired [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	4
Total loans	$ 4	$ 4

Loans - Concentration of Credit

Loans - Concentration of Credit Risk (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Receivables [Abstract]
Interest only residential mortgage loans	$ 3,366	$ 3,362

Allowance for Credit Losses - E

Allowance for Credit Losses - ECL Estimates (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)scenario	Jan. 01, 2020USD ($)
Measurement of ECL Measurements [Line Items]
Number of forward-looking economic scenarios | scenario	3
Reasonable and supportable forecast period for consensus economic scenarios	2 years
Reversion period for average historical values	20 years
Reversion period for most assumption variables	3 years
Management judgment allowance for risk factors associated with large loan exposure in our commercial loan portfolio | $	$ 220	$ 125
Downside Scenario [Member]
Measurement of ECL Measurements [Line Items]
Policy interest rate (percent, less than)		0.50%
Forecast Period 2020 [Member] | Central Scenario [Member]
Measurement of ECL Measurements [Line Items]
Inflation (percent)		2.00%
Forecast Period 2020 [Member] | Upside Scenario [Member]
Measurement of ECL Measurements [Line Items]
GDP growth rate (percent)		4.00%

Allowance for Credit Losses - U

Allowance for Credit Losses - Updates to Economic Scenarios for Impact of Covid-19 (Details) $ in Millions	Mar. 31, 2020USD ($)quarterscenarioYear	Jan. 01, 2020USD ($)
Measurement of ECL Measurements [Line Items]
Number of COVID-19 economic scenarios | scenario	3
Increase to management judgment allowance for risk factors associated with large loan exposure in our commercial loan portfolio	$ 95
Management judgment allowance for risk factors associated with large loan exposure in our commercial loan portfolio	220	$ 125
Increase to management judgment allowance for recent economic events and deteriorating conditions in our consumer loan portfolio	$ 41
Forecast Period 2020 [Member] | Mild Scenario [Member]
Measurement of ECL Measurements [Line Items]
Number of quarters of economic contraction for GDP | quarter	1
Forecast Period 2020 [Member] | Moderate Scenario [Member]
Measurement of ECL Measurements [Line Items]
Equity price decline (exceeds percent for all periods)	20.00%
Forecast Period 2020 [Member] | Severe Scenario [Member]
Measurement of ECL Measurements [Line Items]
Equity price decline (exceeds percent for all periods)	40.00%
Forecast Period through late 2021 [Member] | Severe Scenario [Member]
Measurement of ECL Measurements [Line Items]
Housing price decrease (exceeds percent)	20.00%
Forecast Period beginning in the second quarter of 2020 [Member] | Severe Scenario [Member]
Measurement of ECL Measurements [Line Items]
10-year U.S. Treasury bond yields (below percent)	(1.00%)
Minimum [Member] | Mild Scenario [Member]
Measurement of ECL Measurements [Line Items]
Period of moderate worsening for unemployment and housing prices | Year	1
Maximum [Member] | Mild Scenario [Member]
Measurement of ECL Measurements [Line Items]
Period of moderate worsening for unemployment and housing prices | Year	2

Allowance for Credit Losses - A

Allowance for Credit Losses - Allowance for Credit Losses and Liability for Off-balance Sheet Credit Exposures (Details) - USD ($) $ in Millions		Mar. 31, 2020		Jan. 01, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Loans		$ 931		$ 467	$ 637	$ 583	$ 541
Securities held-to-maturity	[2]	2	[1]	2
Other financial assets measured at amortized cost	[3]	5		3
Securities available-for-sale	[2]	2	[1]	3
Total allowance for credit losses		940		475
Liability for off-balance sheet credit exposures		$ 371		$ 158	158	$ 89	96
As Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Loans					637
Securities held-to-maturity	[2]				0
Other financial assets measured at amortized cost	[3]				0
Securities available-for-sale	[2]				0
Total allowance for credit losses					637
Liability for off-balance sheet credit exposures					$ 104		$ 96
[1]	As discussed in Note 21, "New Accounting Pronouncements," beginning January 1, 2020, an allowance for credit losses is recognized for debt securities while, prior to January 1, 2020, debt securities were assessed for other-than-temporary impairment. At December 31, 2019, we did not consider any of our debt securities to be other-than-temporarily impaired
[2]	See Note 4, "Securities," for additional information regarding the allowance for credit losses associated with our security portfolios.
[3]	Primarily includes accrued interest receivables and customer acceptances.

Allowance for Credit Losses - S

Allowance for Credit Losses - Summary of Changes in Allowance for Credit Losses and Related Loan Balance by Product (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	$ 637	$ 541
Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses			$ (170)
Provision charged (credited) to income	512	58
Charge offs	(56)	(21)
Recoveries	8	5
Net (charge offs) recoveries	(48)	(16)
Balance at end of period	931	583
Commercial Loans [Member] | Real Estate, Including Construction [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period		116
Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses			(112)
Provision charged (credited) to income	51	3
Charge offs	0	0
Recoveries	0	0
Net (charge offs) recoveries	0	0
Balance at end of period	92	119
Commercial Loans [Member] | Business and Corporate Banking [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period		219
Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses			(60)
Provision charged (credited) to income	213	22
Charge offs	(12)	(2)
Recoveries	2	0
Net (charge offs) recoveries	(10)	(2)
Balance at end of period	382	239
Commercial Loans [Member] | Global Banking [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period		108
Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses			51
Provision charged (credited) to income	110	14
Charge offs	(19)	0
Recoveries	0	0
Net (charge offs) recoveries	(19)	0
Balance at end of period	248	122
Commercial Loans [Member] | Other Commercial [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period		15
Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses			(5)
Provision charged (credited) to income	1	0
Charge offs	0	0
Recoveries	0	0
Net (charge offs) recoveries	0	0
Balance at end of period	5	15
Consumer Loans [Member] | Residential Mortgages [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period		13
Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses			(86)
Provision charged (credited) to income	30	(1)
Charge offs	1	(4)
Recoveries	2	2
Net (charge offs) recoveries	3	(2)
Balance at end of period	(41)	10
Consumer Loans [Member] | Home Equity Mortgages [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period		7
Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses			7
Provision charged (credited) to income	3	1
Charge offs	(2)	(1)
Recoveries	2	1
Net (charge offs) recoveries	0	0
Balance at end of period	16	8
Consumer Loans [Member] | Credit Cards [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period		58
Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses			32
Provision charged (credited) to income	95	16
Charge offs	(22)	(13)
Recoveries	2	2
Net (charge offs) recoveries	(20)	(11)
Balance at end of period	212	63
Consumer Loans [Member] | Other consumer [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period		5
Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses			$ 3
Provision charged (credited) to income	9	3
Charge offs	(2)	(1)
Recoveries	0	0
Net (charge offs) recoveries	(2)	(1)
Balance at end of period	17	$ 7
As Previously Reported [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	637
As Previously Reported [Member] | Commercial Loans [Member] | Real Estate, Including Construction [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	153
As Previously Reported [Member] | Commercial Loans [Member] | Business and Corporate Banking [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	239
As Previously Reported [Member] | Commercial Loans [Member] | Global Banking [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	106
As Previously Reported [Member] | Commercial Loans [Member] | Other Commercial [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	9
As Previously Reported [Member] | Consumer Loans [Member] | Residential Mortgages [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	12
As Previously Reported [Member] | Consumer Loans [Member] | Home Equity Mortgages [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	6
As Previously Reported [Member] | Consumer Loans [Member] | Credit Cards [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	105
As Previously Reported [Member] | Consumer Loans [Member] | Other consumer [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	7
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	467
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Commercial Loans [Member] | Real Estate, Including Construction [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	41
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Commercial Loans [Member] | Business and Corporate Banking [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	179
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Commercial Loans [Member] | Global Banking [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	157
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Commercial Loans [Member] | Other Commercial [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	4
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Consumer Loans [Member] | Residential Mortgages [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	(74)
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Consumer Loans [Member] | Home Equity Mortgages [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	13
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Consumer Loans [Member] | Credit Cards [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	137
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Consumer Loans [Member] | Other consumer [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	$ 10

Allowance for Credit Losses All

Allowance for Credit Losses Allowance for Credit Losses - Change in Liability for Off-balance Sheet Credit Exposures (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	$ 158	$ 96
Provision charged (credited) to income	213	(7)
Balance at end of period	371	89
Accounting Standards Update 2016-13 [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Cumulative effect adjustment to initially apply new accounting guidance for measuring credit losses			$ 54	$ 0
As Previously Reported [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Balance at beginning of period	$ 104	$ 96

Allowance for Credit Losses -_2

Allowance for Credit Losses - Accrued Interest Receivables (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)
Financing Receivable, Allowance for Credit Loss [Line Items]
Total accrued interest receivables	$ 321
Allowance for credit losses	3
Accrued interest receivables, net	318
Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total accrued interest receivables	177
Accrued interest receivables charged off during the period	1
Securities Held-to-maturity [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total accrued interest receivables	32
Other Financial Assets Measured at Amortized Cost [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total accrued interest receivables	3
Securities available-for-sale [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total accrued interest receivables	$ 109

Loans Held for Sale (Details)

Loans Held for Sale (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for sale	$ 285	$ 289
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for sale	234	212
Commercial Loans [Member] | Real Estate, Including Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for sale	0	83
Commercial Loans [Member] | Business and Corporate Banking [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for sale	0	35
Commercial Loans [Member] | Global Banking [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for sale	234	94
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for sale	51	77
Consumer Loans [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for sale	$ 51	$ 77

Loans Held for Sale - Additiona

Loans Held for Sale - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for sale	$ 285		$ 289
Revenue associated with the economic hedging program (less than)	(1,354)	$ 1,052
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for sale	234		212
Valuation allowance	0		0
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for sale	51		77
Valuation allowance	1		2
Commercial Loans - Fair Value Option [Member] | Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for sale	206		178
Commercial Loans - Transferred to Held for Sale [Member] | Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for sale	28		34
Residential Mortgage [Member] | Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans held for sale	51		$ 77
Other Income (Loss) [Member] | Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Lower of amortized cost or fair value adjustment	0	0
Residential mortgage banking revenue (expense) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revenue associated with the economic hedging program (less than)	$ (3)	$ (1)

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 458	$ 1,607	$ 1,242
Accumulated impairment loss	1,819		$ 1,035
Goodwill impairment charge	$ 784	$ 0

Derivative Financial Instrume_3

Derivative Financial Instruments - Fair Value of Derivatives and Balance Offsetting (Details) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative Assets		$ 59,784	$ 36,345
Derivative Liabilities		60,948	35,989
Netting assets	[1],[2]	48,099	29,510
Netting liabilities	[1],[2]	48,099	29,510
Less: Gross amounts of cash collateral received subject to enforceable master netting agreements(5)(6)	[1],[3]	6,178	3,683
Less: Gross amounts of cash collateral posted subject to enforceable master netting agreements(5)(6)	[1],[3]	9,131	4,390
Derivative Asset		5,507	3,152
Derivative Liability		3,718	2,089
Less: Gross amounts of financial instrument collateral received not offset		1,443	891
Less: Gross amounts of financial instrument collateral posted not offset		552	553
Net amount of derivative asset		4,064	2,261
Net amount of derivative liability		3,166	1,536
Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Less: Gross amounts of cash collateral received subject to enforceable master netting agreements(5)(6)		6,137	2,538
Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Less: Gross amounts of cash collateral posted subject to enforceable master netting agreements(5)(6)		8,575	4,351
Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[4]	12	16
Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4]	303	186
Interest rate contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5]	19,631	12,267
Interest rate contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5]	22,192	13,356
Foreign exchange contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5]	31,113	16,520
Foreign exchange contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5]	29,734	15,786
Equity contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		4,183	3,753
Equity contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities		3,201	3,993
Precious metals contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5]	2,211	1,158
Precious metals contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5]	2,187	1,389
Credit contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5]	1,961	1,139
Credit contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5]	2,307	1,024
Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[4]	0	0
Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4]	293	165
OTC Cleared [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5],[6]	126	167
OTC Cleared [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5],[6]	17	29
OTC Cleared [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5],[6]	41	0
OTC Cleared [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5],[6]	0	0
OTC Cleared [Member] | Credit contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5],[6]	85	1
OTC Cleared [Member] | Credit contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5],[6]	0	0
OTC Cleared [Member] | Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[4],[6]	0	0
OTC Cleared [Member] | Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4],[6]	2	1
Bilateral OTC [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5],[6]	19,494	11,990
Bilateral OTC [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5],[6]	22,164	13,324
Bilateral OTC [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument, Other [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[4]	211	128
Bilateral OTC [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument, Other [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4]	5	51
Bilateral OTC [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5],[6]	31,072	16,440
Bilateral OTC [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5],[6]	29,727	15,786
Bilateral OTC [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument, Other [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[4],[6]	0	0
Bilateral OTC [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument, Other [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4],[6]	2	0
Bilateral OTC [Member] | Equity contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5],[6]	4,182	3,753
Bilateral OTC [Member] | Equity contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5],[6]	3,201	3,993
Bilateral OTC [Member] | Equity contracts [Member] | Not Designated as Hedging Instrument, Other [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[4],[6]	423	1,354
Bilateral OTC [Member] | Equity contracts [Member] | Not Designated as Hedging Instrument, Other [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4],[6]	929	75
Bilateral OTC [Member] | Precious metals contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5],[6]	2,211	1,087
Bilateral OTC [Member] | Precious metals contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5],[6]	2,040	1,309
Bilateral OTC [Member] | Credit contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5],[6]	1,876	1,138
Bilateral OTC [Member] | Credit contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5],[6]	2,307	1,024
Bilateral OTC [Member] | Credit contracts [Member] | Not Designated as Hedging Instrument, Other [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[4],[6]	30	0
Bilateral OTC [Member] | Credit contracts [Member] | Not Designated as Hedging Instrument, Other [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4],[6]	21	44
Bilateral OTC [Member] | Other Contracts [Member] | Not Designated as Hedging Instrument, Other [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[4],[6],[7]	9	10
Bilateral OTC [Member] | Other Contracts [Member] | Not Designated as Hedging Instrument, Other [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4],[6],[7]	67	85
Bilateral OTC [Member] | Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[4],[6]	0	0
Bilateral OTC [Member] | Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4],[6]	291	164
Bilateral OTC [Member] | Cash Flow Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[4]	0	0
Bilateral OTC [Member] | Cash Flow Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4]	2	1
Bilateral OTC [Member] | Cash Flow Hedging [Member] | Foreign exchange contracts [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[4],[6]	12	16
Bilateral OTC [Member] | Cash Flow Hedging [Member] | Foreign exchange contracts [Member] | Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4],[6]	8	20
Exchange Traded [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5],[6]	11	110
Exchange Traded [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5],[6]	11	3
Exchange Traded [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5],[6]	0	80
Exchange Traded [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5],[6]	7	0
Exchange Traded [Member] | Equity contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5],[6]	1	0
Exchange Traded [Member] | Equity contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5],[6]	0	0
Exchange Traded [Member] | Precious metals contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	[5],[6]	0	71
Exchange Traded [Member] | Precious metals contracts [Member] | Not Designated as Hedging Instrument, Trading [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[5],[6]	$ 147	$ 80
[1]	Netting is performed at a counterparty level in cases where enforceable master netting agreements are in place, regardless of the type of derivative instrument. Therefore, we have not allocated netting to the different types of derivative instruments shown in the table above.
[2]	Represents the netting of derivative receivable and payable balances for the same counterparty under enforceable netting agreements.
[3]	Represents the netting of cash collateral posted and received by counterparty under enforceable netting agreements.
[4]	Derivative assets / liabilities related to cash flow hedges, fair value hedges and derivative instruments held for purposes other than for trading are recorded in other assets / interest, taxes and other liabilities on the consolidated balance sheet.
[5]	Trading related derivative assets / liabilities are recorded in trading assets / trading liabilities on the consolidated balance sheet.
[6]	Over-the-counter ("OTC") derivatives include derivatives executed and settled bilaterally with counterparties without the use of an organized exchange or central clearing house. The credit risk associated with bilateral OTC derivatives is managed through obtaining collateral and enforceable master netting agreements. OTC-cleared derivatives are executed bilaterally in the OTC market but then novated to a central clearing counterparty, whereby the central clearing counterparty becomes the counterparty to each of the original counterparties. Exchange traded derivatives are executed directly on an organized exchange. Credit risk is minimized for OTC-cleared derivatives and exchange traded derivatives through daily margining requirements. In addition, OTC-cleared interest rate and credit derivatives with certain central clearing counterparties are settled daily.
[7]	Consists of swap agreements entered into in conjunction with the sales of Visa Inc. ("Visa") Class B common shares ("Class B Shares").

Derivative Financial Instrume_4

Derivative Financial Instruments Derivative Financial Instruments - Carrying Value of Hedged Items in Fair Value Hedge (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Dec. 31, 2019
Securities available-for-sale [Member]
Derivatives, Fair Value [Line Items]
Carrying amount of hedged items	[1]	$ 10,928	$ 7,277
Active hedged asset adjustments		1,630	554
Discontinued hedged asset adjustments		356	428
Total hedged asset adjustments		1,986	982
Deposits [Member]
Derivatives, Fair Value [Line Items]
Carrying amount of hedged liability items	[1],[2]	3,229
Active hedged liability adjustments	[2]	229
Discontinued hedged liability adjustments	[2]	0
Total hedged liability adjustments	[2]	229
Fixed-rate senior debt obligations recharacterized as time deposits		3,000
Long-term Debt [Member]
Derivatives, Fair Value [Line Items]
Carrying amount of hedged liability items	[1]	5,927	10,975
Active hedged liability adjustments		326	285
Discontinued hedged liability adjustments		(22)	(32)
Total hedged liability adjustments		$ 304	$ 253
[1]	The carrying amount of securities AFS represents the amortized cost basis.
[2]	During the first quarter of 2020, $3.0 billion of fixed-rate senior debt obligations issued to HSBC North America were recharacterized as time deposits. The cumulative amount of fair value hedging adjustments associated with this debt was reclassified to deposits. See Note 14, "Related Party Transactions," for additional information.

Derivative Financial Instrume_5

Derivative Financial Instruments - Gains and Losses on Hedged Items in Fair Value Hedges (Detail) - Net Interest Income [Member] - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivative	[1]	$ (859)	$ (173)
Gain (Loss) on Hedged Items	[1]	803	151
Securities available-for-sale [Member] | Interest rate contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivative	[1]	(1,156)	(257)
Gain (Loss) on Hedged Items	[1]	1,178	350
Deposits [Member] | Interest rate contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivative	[1]	120
Gain (Loss) on Hedged Items	[1]	(146)
Long-term Debt [Member] | Interest rate contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivative	[1]	177	84
Gain (Loss) on Hedged Items	[1]	$ (229)	$ (199)
[1]	During the first quarter of 2020, $3.0 billion of fixed-rate senior debt obligations issued to HSBC North America were recharacterized as time deposits. The cumulative amount of fair value hedging adjustments associated with this debt was reclassified to deposits. See Note 14, "Related Party Transactions," for additional information.

Derivative Financial Instrume_6

Derivative Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Losses related to discontinued cash flow hedge relationships amortized to earnings	$ 6	$ 10
Next twelve months, reclassification of remaining losses to earnings resulting from cash flow hedges	11
Aggregate fair value of all derivative instruments with credit-risk related contingent features	1,220		$ 611
Collateral already posted aggregate fair value	$ 753		$ 316

Derivative Financial Instrume_7

Derivative Financial Instruments - Gains and Losses on Derivative Instruments Designated and Qualifying As Hedging Instruments in Cash Flow Hedges (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in AOCI on Derivatives	$ 113	$ 8
Net Interest Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified From AOCI into Income	(6)	(10)
Foreign exchange contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in AOCI on Derivatives	0	1
Foreign exchange contracts [Member] | Net Interest Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified From AOCI into Income	0	0
Interest rate contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in AOCI on Derivatives	113	7
Interest rate contracts [Member] | Net Interest Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified From AOCI into Income	$ (6)	$ (10)

Derivative Financial Instrume_8

Derivative Financial Instruments - Gains and Losses on Derivative Instruments Held For Trading Purpose (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives		$ 112	$ (152)
Trading revenue [Member] | Interest rate contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives		17	56
Trading revenue [Member] | Foreign exchange contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	[1]	(665)	(14)
Trading revenue [Member] | Equity contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives		1,257	(89)
Trading revenue [Member] | Precious metals contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	[1]	160	17
Trading revenue [Member] | Credit contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives		$ (657)	(122)
Reclassified Amount [Member] | Trading revenue [Member] | Precious metals contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	[1]		$ 151
[1]	During the third quarter of 2019, we changed our presentation for certain derivatives that were previously reported in foreign exchange contracts and began reporting these derivatives in precious metals contracts. As a result, we have reclassified $151 million of gains from foreign exchange contracts to precious metals contracts during the three months ended March 31, 2019 to conform with the current year presentation.

Derivative Financial Instrume_9

Derivative Financial Instruments - Gains and Losses on Derivative Instruments Held For Other Purpose (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Derivatives, Fair Value [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives held for other purposes		$ (1,354)	$ 1,052
Loss on Instruments Designated at Fair Value and Related Derivatives [Member]
Derivatives, Fair Value [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives held for other purposes		(1,419)	1,059
Loss on Instruments Designated at Fair Value and Related Derivatives [Member] | Interest rate contracts [Member]
Derivatives, Fair Value [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives held for other purposes		250	156
Loss on Instruments Designated at Fair Value and Related Derivatives [Member] | Foreign exchange contracts [Member]
Derivatives, Fair Value [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives held for other purposes		(2)	(1)
Loss on Instruments Designated at Fair Value and Related Derivatives [Member] | Equity contracts [Member]
Derivatives, Fair Value [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives held for other purposes		(1,698)	914
Loss on Instruments Designated at Fair Value and Related Derivatives [Member] | Credit contracts [Member]
Derivatives, Fair Value [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives held for other purposes		37	0
Other Income (Loss) [Member] | Interest rate contracts [Member]
Derivatives, Fair Value [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives held for other purposes		(3)	(1)
Other Income (Loss) [Member] | Credit contracts [Member]
Derivatives, Fair Value [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives held for other purposes		51	(10)
Other Income (Loss) [Member] | Other Contracts [Member]
Derivatives, Fair Value [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives held for other purposes	[1]	$ 11	$ (6)
[1]	Consists of swap agreements entered into in conjunction with the sales of Visa Class B Shares.

Derivative Financial Instrum_10

Derivative Financial Instruments - Credit-Risk Related Contingent Features (Detail) $ in Millions	Mar. 31, 2020USD ($)
One-notch Downgrade [Member]
Derivative [Line Items]
Amount of additional collateral to be posted upon downgrade	$ 51
Two-notch Downgrade [Member]
Derivative [Line Items]
Amount of additional collateral to be posted upon downgrade	$ 100

Derivative Financial Instrum_11

Derivative Financial Instruments - Notional Value of Derivative Contracts (Detail) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Total		$ 4,613,258	$ 4,807,851
Interest rate contracts [Member]
Derivative [Line Items]
Total		2,941,572	3,051,548
Interest Rate Futures and Forwards [Member]
Derivative [Line Items]
Total		765,243	597,980
Interest Rate Swap [Member]
Derivative [Line Items]
Total		1,938,082	2,130,442
Interest Rate Options Written [Member]
Derivative [Line Items]
Total		116,380	158,861
Interest Rate Options Purchased [Member]
Derivative [Line Items]
Total		121,867	164,265
Foreign exchange contracts [Member]
Derivative [Line Items]
Total		1,420,633	1,520,980
Foreign Exchange Swaps, Futures and Forwards [Member]
Derivative [Line Items]
Total		1,304,885	1,362,959
Foreign Exchange Options Written [Member]
Derivative [Line Items]
Total		35,269	44,876
Foreign Exchange Options Purchased [Member]
Derivative [Line Items]
Total		36,088	46,085
Foreign Exchange Spot [Member]
Derivative [Line Items]
Total		44,391	67,060
Commodities, equities and precious metals contracts [Member]
Derivative [Line Items]
Total		154,794	144,230
Commodities, Equities and Precious Metals, Swaps, Futures and Forwards [Member]
Derivative [Line Items]
Total		73,740	55,678
Commodities, Equities and Precious Metals Options Written [Member]
Derivative [Line Items]
Total		35,418	39,035
Commodities, Equities and Precious Metals Options Purchased [Member]
Derivative [Line Items]
Total		45,636	49,517
Credit contracts [Member]
Derivative [Line Items]
Total		95,364	90,049
Other Contracts [Member]
Derivative [Line Items]
Total	[1]	$ 895	$ 1,044
[1]	Consists of swap agreements entered into in conjunction with the sales of Visa Class B Shares.

Fair Value Option - Additional

Fair Value Option - Additional Information (Details) - Loans Held For Sale [Member] - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value option loan in nonaccrual status	$ 0	$ 0
Fair value option, loans 90 days or more past due	$ 0	$ 0

Fair Value Option - Summary of

Fair Value Option - Summary of Fair Value and Unpaid Principal Balance (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Student Loans Held for Investment [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans, designated under fair value option	$ 37
Loans held for investment, Unpaid Principal Balance	39
Fair value over (under) unpaid principal balance	(2)
Loans Held For Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Commercial loans held for sale, Fair Value	206	$ 178
Commercial loans held for sale, Unpaid Principal Balance	263	189
Fair value over (under) unpaid principal balance	(57)	(11)
Securities sold under repurchase agreements [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value over (under) unpaid principal balance		0
Securities sold under repurchase agreements, Fair Value	0	373
Securities sold under repurchase agreements, Unpaid Principal Balance		373
Long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value over (under) unpaid principal balance	157	218
Fixed rate long-term debt, Fair Value	898	959
Fixed rate long-term debt, Unpaid Principal Balance	741	741
Long-term debt [Member] | Structured Notes [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value over (under) unpaid principal balance	(699)	1,201
Hybrid instruments, Unpaid Principal Balance	8,176	8,187
Hybrid instruments, structured notes, Fair Value	7,477	9,388
Structured Deposits [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value over (under) unpaid principal balance	(907)	(282)
Hybrid instruments, structured deposits, Fair Value	6,371	7,209
Hybrid instruments, Unpaid Principal Balance	$ 7,278	$ 7,491

Fair Value Option - Components

Fair Value Option - Components of Gain (Loss) on Instruments at Fair Value and Related Derivatives (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020		Mar. 31, 2019
Components Of Gain On Instruments At Fair Value And Related Derivatives [Line Items]
Mark-to-market on related derivatives		$ (1,354)		$ 1,052
Gain (loss) on instruments designated at fair value and related derivatives		(22)		(9)
Gain (Loss) on Instruments Designated at Fair Value and Related Derivatives [Member]
Components Of Gain On Instruments At Fair Value And Related Derivatives [Line Items]
Interest rate and other components	[1]	1,445		(1,081)
Credit risk component, total	[3]	(54)	[2]	3
Total mark-to-market on financial instruments designated at fair value		1,391		(1,078)
Mark-to-market on related derivatives		(1,419)		1,059
Net realized gain on related long-term debt derivatives		6		10
Gain (loss) on instruments designated at fair value and related derivatives		(22)		(9)
Gain (Loss) on Instruments Designated at Fair Value and Related Derivatives [Member] | Loans [Member]
Components Of Gain On Instruments At Fair Value And Related Derivatives [Line Items]
Interest rate and other components	[1]	0		0
Credit risk component, assets	[3]	(54)	[2]	3
Total mark-to-market on financial instruments designated at fair value		(54)		3
Mark-to-market on related derivatives		37		0
Net realized gain on related long-term debt derivatives		0		0
Gain (loss) on instruments designated at fair value and related derivatives		(17)		3
Gain (Loss) on Instruments Designated at Fair Value and Related Derivatives [Member] | Long-term debt [Member]
Components Of Gain On Instruments At Fair Value And Related Derivatives [Line Items]
Interest rate and other components	[1]	(134)		(69)
Credit risk component, liabilities	[3]	0	[2]	0
Total mark-to-market on financial instruments designated at fair value		(134)		(69)
Mark-to-market on related derivatives		150		53
Net realized gain on related long-term debt derivatives		6		10
Gain (loss) on instruments designated at fair value and related derivatives		22		(6)
Gain (Loss) on Instruments Designated at Fair Value and Related Derivatives [Member] | Hybrid Instrument [Member]
Components Of Gain On Instruments At Fair Value And Related Derivatives [Line Items]
Interest rate and other components	[1]	1,579		(1,012)
Credit risk component, liabilities	[3]	0	[2]	0
Total mark-to-market on financial instruments designated at fair value		1,579		(1,012)
Mark-to-market on related derivatives		(1,606)		1,006
Net realized gain on related long-term debt derivatives		0		0
Gain (loss) on instruments designated at fair value and related derivatives		$ (27)		$ (6)
[1]	As it relates to hybrid instruments, interest rate and other components primarily includes interest rate, foreign exchange and equity contract risks.
[2]	During the three months ended March 31, 2020, the loss in the credit risk component for loans and loans held for sale was attributable to the widening of credit spreads associated with certain commercial loans held for sale which were impacted by the spread of the COVID-19 pandemic.
[3]	The fair value movement on fair value option liabilities attributable to our own credit spread is recorded in other comprehensive income.

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) - (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Unrealized gains (losses) on investment securities:
Balance at beginning of period		$ (114)	$ (519)
Cumulative effect of new accounting principle in period of adoption				$ (170)
Other comprehensive income for period:
Net unrealized gains arising during period, net of tax		775	180
Reclassification adjustment for (gains) losses realized in net income (loss), net of tax	[1]	(21)	(5)
Reversal of provision for credit losses realized in net income (loss), net of tax	[2]	1	0
Amortization of net unrealized losses on securities transferred from available-for-sale to held-to-maturity realized in net income (loss), net of tax	[3]	3	4
Total other comprehensive income for period		758	179
Balance at end of period		644	(340)
Unrealized gains (losses) on fair value option liabilities attributable to our own credit spread:
Balance at beginning of period		(9)	301
Other comprehensive income (loss) for period:
Net unrealized gains (losses) arising during period, net of tax		407	(111)
Total other comprehensive income (loss) for period		407	(111)
Balance at end of period		398	190
Unrealized gains (losses) on derivatives designated as cash flow hedges:
Balance at beginning of period		(151)	(159)
Other comprehensive income (loss) for period:
Net unrealized gains arising during period, net of tax		85	6
Reclassification adjustment for losses realized in net income (loss), net of tax	[4]	5	8
Total other comprehensive income for period		90	14
Balance at end of period		(61)	(145)
Pension and postretirement benefit liability:
Balance at beginning of period		(3)	11
Change in unfunded pension and postretirement liability, net of tax		0	(3)
Total other comprehensive loss for period		0	(3)
Balance at end of period		(3)	8
Total accumulated other comprehensive income (loss) at end of period		978	(287)	(279)
Accounting Standards Update 2016-13 [Member]
Unrealized gains (losses) on investment securities:
Cumulative effect of new accounting principle in period of adoption	[5]			$ 2	$ 0
As Previously Reported [Member]
Unrealized gains (losses) on investment securities:
Balance at beginning of period		$ (116)	$ (519)
[1]	Amount reclassified to net income (loss) is included in other securities gains, net in our consolidated statement of income (loss).
[2]	Changes in the allowance for credit losses on securities available-for-sale are included in the provision for credit losses in our consolidated statement of income (loss).
[3]	Amount amortized to net income (loss) is included in interest income in our consolidated statement of income (loss). During 2014, we transferred securities from available-for-sale to held-to-maturity. At the date of transfer, AOCI included net pretax unrealized losses related to the transferred securities which are being amortized over the remaining contractual life of each security as an adjustment of yield in a manner consistent with the amortization of any premium or discount.
[4]	Amount reclassified to net income (loss) is included in net interest income in our consolidated statement of income (loss).
[5]	See Note 21, "New Accounting Pronouncements," for additional discussion.

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Loss) - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax (benefit) expense included in net unrealized gains (losses), investment securities	$ 245	$ 55
Tax included in reclassification, investment securities	(7)	(2)
Tax included in provision for credit losses, investment securities	0	0
Tax included in amortization, investment securities	1	1
Tax (benefit) expense included in net unrealized gains (losses), fair value option liabilities	128	(35)
Tax (benefit) expense included in net unrealized gains (losses), cash flow hedges	28	2
Tax included in reclassification, cash flow hedges	1	2
Tax included in net unrealized gains (losses), pension and postretirement benefit liability	$ 0	$ (1)
Accounting Standards Update 2016-13 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax on cumulative effect for AFS securities			$ 1	$ 0

Pension and Other Postretirem_3

Pension and Other Postretirement Benefits-Net Periodic Benefit Cost (Detail) - HSBC North America [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Postretirement Plans Other Than Pensions [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost (less than $1 million for post retirement plans other than pensions)	$ 1	$ 1
HSBC North America Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on projected benefit obligation	12	15
Expected return on plan assets	(19)	(18)
Amortization of net actuarial loss	2	7
Administrative costs	1	1
Net periodic benefit cost (less than $1 million for post retirement plans other than pensions)	$ (4)	$ 5

Fee Income from Contracts wit_3

Fee Income from Contracts with Customers (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Fee income from contracts with customers		$ 283	$ 272
Other non-fee revenues		104	118
Total other revenues	[1]	387	390
Deferred fee income		3		$ 2
Credit card fees, net [Member]
Disaggregation of Revenue [Line Items]
Fee income from contracts with customers		11	12
Interchange fees		22	22
Rewards program costs		13	12
Trust and investment management fees [Member]
Disaggregation of Revenue [Line Items]
Fee income from contracts with customers		31	30
Account services [Member]
Disaggregation of Revenue [Line Items]
Fee income from contracts with customers		61	65
Credit facilities [Member]
Disaggregation of Revenue [Line Items]
Fee income from contracts with customers		73	69
Other fees [Member]
Disaggregation of Revenue [Line Items]
Fee income from contracts with customers		17	13
Other fees and commissions [Member]
Disaggregation of Revenue [Line Items]
Fee income from contracts with customers		151	147
Servicing and other fees from HSBC affiliates [Member]
Disaggregation of Revenue [Line Items]
Fee income from contracts with customers		88	81
Insurance [Member]
Disaggregation of Revenue [Line Items]
Fee income from contracts with customers	[2]	$ 2	$ 2
[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.
[2]	Included within other income (loss) in the consolidated statement of income (loss).

Related Party Transactions - Su

Related Party Transactions - Summary of Related Party Transactions (Details) - USD ($) $ in Millions		Mar. 31, 2020		Dec. 31, 2019		Mar. 31, 2019
Assets:
Cash and due from banks		$ 983		$ 1,744
Interest bearing deposits with banks		26,496		2,038
Securities purchased under agreements to resell		4,643		17,838
Trading assets		29,217		28,452
Loans		81,728		68,553
Other		8,272		6,723
Total assets		205,077	[1]	175,375	[1]	$ 180,921
Liabilities:
Deposits		136,723		119,693		$ 113,639
Trading liabilities		3,923		3,235
Short-term borrowings		17,579		3,659
Long-term debt		24,777		26,697
Other		3,756		3,835
Total liabilities	[1]	186,758		157,119
Affiliated Entity [Member]
Assets:
Cash and due from banks		199		850
Interest bearing deposits with banks		97		40
Securities purchased under agreements to resell	[2]	673		4,600
Trading assets		159		79
Loans		3,087		2,343
Other	[2]	728		456
Total assets		4,943		8,368
Liabilities:
Deposits		17,360		9,000
Trading liabilities		402		293
Short-term borrowings		5,418		1,166
Long-term debt		4,849		7,848
Other	[2]	212		931
Total liabilities		$ 28,241		$ 19,238
[1]	The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at March 31, 2020 and December 31, 2019 which are consolidated on our balance sheet. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 17, "Variable Interest Entities," for additional information. Assets: Loans $39 million and $0 million. Other assets $92 million and $98 million. Total assets $131 million and $98 million respectively. Liabilities: Interest, taxes and other liabilities $32 million and $38 million. Total liabilities $32 million and $38 million, respectively.
[2]	Other assets and other liabilities primarily consist of derivative balances associated with hedging activities and other miscellaneous account receivables and payables.

Related Party Transactions - _2

Related Party Transactions - Summary of Related Party Transactions (Income - Expense) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Related Party Transaction [Line Items]
Interest income		$ 1,067	$ 1,277
Interest expense		(563)	(715)
Net interest income		504	562
Trading revenue (expense)		14	133
Servicing and other fees from HSBC affiliates: [Abstract]
Other revenues		283	272
Gain (loss) on instruments designated at fair value and related derivatives		(22)	(9)
Support services from HSBC affiliates:
Total support services from HSBC affiliates		(382)	(380)
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Interest income		26	43
Interest expense		(120)	(124)
Net interest income		(94)	(81)
Trading revenue (expense)		(261)	(1,514)
Servicing and other fees from HSBC affiliates: [Abstract]
Gain (loss) on instruments designated at fair value and related derivatives		(1,606)	1,008
Support services from HSBC affiliates:
Total support services from HSBC affiliates		(382)	(380)
Rental income from HSBC affiliates, net	[1]	12	12
Stock based compensation expense	[2]	(6)	(6)
HSBC Markets (USA) Inc. (HMUS) and subsidiaries [Member]
Support services from HSBC affiliates:
Total support services from HSBC affiliates		(27)	(27)
Other HSBC affiliates [Member]
Support services from HSBC affiliates:
Total support services from HSBC affiliates		(92)	(76)
HSBC Technology and Services (USA) (HTSU) [Member]
Support services from HSBC affiliates:
Total support services from HSBC affiliates		(263)	(277)
Servicing and other fees from HSBC affiliates [Member]
Servicing and other fees from HSBC affiliates: [Abstract]
Other revenues		88	81
Servicing and other fees from HSBC affiliates [Member] | Affiliated Entity [Member]
Servicing and other fees from HSBC affiliates: [Abstract]
Other revenues		88	81
Servicing and other fees from HSBC affiliates [Member] | HSBC Bank plc [Member]
Servicing and other fees from HSBC affiliates: [Abstract]
Other revenues		47	35
Servicing and other fees from HSBC affiliates [Member] | HSBC Markets (USA) Inc. (HMUS) and subsidiaries [Member]
Servicing and other fees from HSBC affiliates: [Abstract]
Other revenues		24	30
Servicing and other fees from HSBC affiliates [Member] | Other HSBC affiliates [Member]
Servicing and other fees from HSBC affiliates: [Abstract]
Other revenues		$ 17	$ 16
[1]	We receive rental income from our affiliates, and in some cases pay rental expense to our affiliates, for rent on certain office space. Net rental income from our affiliates is recorded as a component of occupancy expense, net in our consolidated statement of income (loss).
[2]	Employees may participate in one or more stock compensation plans sponsored by HSBC. These expenses are included in salaries and employee benefits in our consolidated statement of income (loss). Certain employees are also eligible to participate in a defined benefit pension plan and other postretirement plans sponsored by HSBC North America which are discussed in Note 12, "Pension and Other Postretirement Benefits."

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Long-term debt	$ 24,777,000,000	$ 26,697,000,000
Notional value of derivative contracts	4,613,258,000,000	4,807,851,000,000
Preferred stock issued	1,265,000,000	1,265,000,000
HNAH [Member]
Related Party Transaction [Line Items]
Long-term debt	4,800,000,000	7,800,000,000
Maximum borrowing capacity	150,000,000	150,000,000
Amount outstanding under the loan agreement	0	0
Preferred stock issued	1,265,000,000	1,265,000,000
Preferred stock outstanding	1,265,000,000	1,265,000,000
HMUS [Member]
Related Party Transaction [Line Items]
Extended loans and lines of credit	12,000,000,000	12,000,000,000
Amount outstanding on line of credit	3,000,000,000	2,300,000,000
Loans and leases receivable from related parties	3,032,000,000	2,296,000,000
Other HSBC affiliates [Member]
Related Party Transaction [Line Items]
Extended loans and lines of credit	4,700,000,000	4,700,000,000
Amount outstanding on line of credit	0	0
Loans and leases receivable from related parties	55,000,000	47,000,000
HSBC Affiliates [Member]
Related Party Transaction [Line Items]
Long-term debt	4,849,000,000	7,848,000,000
Loans and leases receivable from related parties	3,087,000,000	2,343,000,000
Notional value of derivative contracts	1,005,300,000,000	1,111,500,000,000
Fair value of derivative assets and liabilities	116,000,000	$ 90,000,000
Fixed Rate Note Maturing May 2021 [Member] | HNAH [Member] | Senior debt [Member]
Related Party Transaction [Line Items]
Long-term debt	2,000,000,000
Floating Rate Note Maturing May 2025 [Member] | HNAH [Member] | Subordinated Debt [Member]
Related Party Transaction [Line Items]
Long-term debt	800,000,000
Fixed Rate Note Maturing September 2025 [Member] | HNAH [Member] | Senior debt [Member]
Related Party Transaction [Line Items]
Long-term debt	2,000,000,000
Deposits [Member]
Related Party Transaction [Line Items]
Fixed-rate senior debt obligations recharacterized as time deposits	3,000,000,000
Deposits [Member] | Fixed Rate Note Maturing March 2021 [Member]
Related Party Transaction [Line Items]
Fixed-rate senior debt obligations recharacterized as time deposits	1,500,000,000
Deposits [Member] | Fixed Rate Note Maturing March 2026 [Member]
Related Party Transaction [Line Items]
Fixed-rate senior debt obligations recharacterized as time deposits	$ 1,500,000,000

Related Party Transactions - _3

Related Party Transactions - Summary of Loans (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
HMUS [Member]
Related Party Transaction [Line Items]
Loans and leases receivable from related parties	$ 3,032	$ 2,296
Other short-term affiliate lending [Member]
Related Party Transaction [Line Items]
Loans and leases receivable from related parties	55	47
HSBC Affiliates [Member]
Related Party Transaction [Line Items]
Loans and leases receivable from related parties	$ 3,087	$ 2,343

Business Segments Additional In

Business Segments Additional Information (Details)	3 Months Ended
	Mar. 31, 2020segment
Segment Reporting [Abstract]
Number of reportable segments	5

Business Segments - Summary on

Business Segments - Summary on Reconciliation of Results Under Ifrs to Us Gaap (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020		Mar. 31, 2019	Dec. 31, 2019
Operating Statistics [Line Items]
Net Interest Income		$ 519		$ 624
Group Reporting Basis Other operating income		371		338
Group Reporting Basis Total operating income		890		962
Expected credit losses / provision for credit losses		379
Expected credit losses/provision for credit losses				10
Group Reporting Basis Revenues		511		952
Operating Expenses		1,509		748
Group Reporting Basis Profit (Loss) Before Income Tax		(998)		204
Total Assets		269,609		209,645
Group Reporting Basis Total loans, net		78,655		69,214
Group Reporting Basis Goodwill		358		1,260
Group Reporting Basis Total deposits		124,315		98,225
Net interest income		504		562
Other operating income	[1]	387		390
Total operating income		891		952
Provision for credit losses		726
Provision for credit losses		512		58
Total income		165		894
Operating expenses		1,605		750
Income (loss) before income tax		(1,440)		144
Total assets		205,077	[2]	180,921	$ 175,375	[2]
Total loans, net		80,797		70,451	67,916
Goodwill		458		1,607	1,242
Total deposits		136,723		113,639	$ 119,693
Group Reporting Basis Adjustments [Member]
Operating Statistics [Line Items]
Net Interest Income	[3]	3		6
Group Reporting Basis Other operating income	[3]	(4)		(17)
Group Reporting Basis Total operating income	[3]	(1)		(11)
Expected credit losses / provision for credit losses	[3]	347
Expected credit losses/provision for credit losses	[3]			41
Group Reporting Basis Revenues	[3]	(348)		(52)
Operating Expenses	[3]	94		8
Group Reporting Basis Profit (Loss) Before Income Tax	[3]	(442)		(60)
Total Assets	[3]	(64,532)		(28,724)
Group Reporting Basis Total loans, net	[3]	(4,596)		(1,797)
Group Reporting Basis Goodwill	[3]	100		347
Group Reporting Basis Total deposits	[3]	(7,066)		(2,827)
Group Reporting Basis Reclassifications [Member]
Operating Statistics [Line Items]
Net Interest Income	[4]	(18)		(68)
Group Reporting Basis Other operating income	[4]	20		69
Group Reporting Basis Total operating income	[4]	2		1
Expected credit losses / provision for credit losses	[4]	0
Expected credit losses/provision for credit losses	[4]			7
Group Reporting Basis Revenues	[4]	2		(6)
Operating Expenses	[4]	2		(6)
Group Reporting Basis Profit (Loss) Before Income Tax	[4]	0		0
Total Assets	[4]	0		0
Group Reporting Basis Total loans, net	[4]	6,738		3,034
Group Reporting Basis Goodwill	[4]	0		0
Group Reporting Basis Total deposits	[4]	19,474		18,241
RBWM [Member] | Operating Segments [Member]
Operating Statistics [Line Items]
Net Interest Income		195		221
Group Reporting Basis Other operating income		59		65
Group Reporting Basis Total operating income		254		286
Expected credit losses / provision for credit losses		140
Expected credit losses/provision for credit losses				21
Group Reporting Basis Revenues		114		265
Operating Expenses		660		311
Group Reporting Basis Profit (Loss) Before Income Tax		(546)		(46)
Total Assets		18,954		18,733
Group Reporting Basis Total loans, net		17,701		16,885
Group Reporting Basis Goodwill		0		581
Group Reporting Basis Total deposits		39,083		33,459
CMB [Member] | Operating Segments [Member]
Operating Statistics [Line Items]
Net Interest Income		208		201
Group Reporting Basis Other operating income		58		58
Group Reporting Basis Total operating income		266		259
Expected credit losses / provision for credit losses		123
Expected credit losses/provision for credit losses				6
Group Reporting Basis Revenues		143		253
Operating Expenses		146		138
Group Reporting Basis Profit (Loss) Before Income Tax		(3)		115
Total Assets		31,540		25,612
Group Reporting Basis Total loans, net		30,370		24,447
Group Reporting Basis Goodwill		358		358
Group Reporting Basis Total deposits		32,309		22,323
GB&M [Member] | Operating Segments [Member]
Operating Statistics [Line Items]
Net Interest Income		81		151
Group Reporting Basis Other operating income		264		175
Group Reporting Basis Total operating income		345		326
Expected credit losses / provision for credit losses		115
Expected credit losses/provision for credit losses				(17)
Group Reporting Basis Revenues		230		343
Operating Expenses		187		206
Group Reporting Basis Profit (Loss) Before Income Tax		43		137
Total Assets		114,802		78,899
Group Reporting Basis Total loans, net		22,461		20,068
Group Reporting Basis Goodwill		0		0
Group Reporting Basis Total deposits		40,417		28,274
PB [Member] | Operating Segments [Member]
Operating Statistics [Line Items]
Net Interest Income		31		37
Group Reporting Basis Other operating income		16		16
Group Reporting Basis Total operating income		47		53
Expected credit losses / provision for credit losses		0
Expected credit losses/provision for credit losses				(1)
Group Reporting Basis Revenues		47		54
Operating Expenses		370		53
Group Reporting Basis Profit (Loss) Before Income Tax		(323)		1
Total Assets		7,159		6,686
Group Reporting Basis Total loans, net		6,084		5,584
Group Reporting Basis Goodwill		0		321
Group Reporting Basis Total deposits		8,201		7,540
CC [Member] | Operating Segments [Member]
Operating Statistics [Line Items]
Net Interest Income		4		14
Group Reporting Basis Other operating income		(26)		24
Group Reporting Basis Total operating income		(22)		38
Expected credit losses / provision for credit losses		1
Expected credit losses/provision for credit losses				1
Group Reporting Basis Revenues		(23)		37
Operating Expenses		146		40
Group Reporting Basis Profit (Loss) Before Income Tax		(169)		(3)
Total Assets		97,154		79,715
Group Reporting Basis Total loans, net		2,039		2,230
Group Reporting Basis Goodwill		0		0
Group Reporting Basis Total deposits		$ 4,305		$ 6,629
[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.
[2]	The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at March 31, 2020 and December 31, 2019 which are consolidated on our balance sheet. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 17, "Variable Interest Entities," for additional information. Assets: Loans $39 million and $0 million. Other assets $92 million and $98 million. Total assets $131 million and $98 million respectively. Liabilities: Interest, taxes and other liabilities $32 million and $38 million. Total liabilities $32 million and $38 million, respectively.
[3]	Represents adjustments associated with differences between U.S. GAAP and the Group Reporting Basis.
[4]	epresents differences in financial statement presentation between U.S. GAAP and the Group Reporting Basis.

Retained Earnings and Regulat_3

Retained Earnings and Regulatory Capital Requirements - Additional Information (Details) $ in Millions	Dec. 31, 2019USD ($)
Banking and Thrift [Abstract]
Restricted cash	$ 2,475

Retained Earnings and Regulat_4

Retained Earnings and Regulatory Capital Requirements - Capital Amounts and Ratios in Accordance With Current Banking Regulations (Details) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
HSBC USA Inc [Member]
Common equity Tier 1 ratio:
Capital Amount, Common Equity Tier 1		$ 15,622	$ 15,876
Well Capitalized Ratio, Common Equity Tier 1	[1],[2]	4.50%	4.50%
Actual Ratio, Common equity Tier 1		11.90%	13.10%
Tier 1 capital ratio:
Capital Amount, Tier 1 capital		$ 16,887	$ 17,141
Well-Capitalized Ratio, Tier 1 capital	[1]	6.00%	6.00%
Actual Ratio, Tier 1 Capital		12.90%	14.10%
Total capital ratio:
Capital Amount		$ 20,932	$ 19,743
Well-Capitalized Ratio	[1]	10.00%	10.00%
Actual Ratio, Total Capital		16.00%	16.30%
Tier 1 leverage ratio:
Capital Amount, Tier 1 leverage capital		$ 16,887	$ 17,141
Well-Capitalized Ratio, Tier 1 leverage capital	[1],[2]	4.00%	4.00%
Actual Ratio, Tier 1 leverage capital		9.00%	9.90%
Supplementary Leverage Ratio [Abstract]
Capital Amount, Supplementary Leverage Ratio		$ 16,887	$ 17,141
Well-capitalized Ratio, Supplementary Leverage Ratio	[1],[3]	3.00%	3.00%
Actual Ratio, Supplementary Leverage Ratio		6.50%	6.90%
Risk weighted assets:
Risk Weighted Assets	[4]	$ 130,901	$ 121,407
Adjusted Quarterly Average Assets [Abstract]
Adjusted quarterly average assets	[5]	187,962	173,270
Total Leverage Exposure [Abstract]
Total leverage exposure	[6]	258,783	247,590
HSBC Bank USA [Member]
Common equity Tier 1 ratio:
Capital Amount, Common Equity Tier 1		$ 17,814	$ 18,043
Well Capitalized Ratio, Common Equity Tier 1	[1]	6.50%	6.50%
Actual Ratio, Common equity Tier 1		14.00%	15.20%
Tier 1 capital ratio:
Capital Amount, Tier 1 capital		$ 20,314	$ 20,543
Well-Capitalized Ratio, Tier 1 capital	[1]	8.00%	8.00%
Actual Ratio, Tier 1 Capital		15.90%	17.30%
Total capital ratio:
Capital Amount		$ 23,063	$ 22,724
Well-Capitalized Ratio	[1]	10.00%	10.00%
Actual Ratio, Total Capital		18.10%	19.20%
Tier 1 leverage ratio:
Capital Amount, Tier 1 leverage capital		$ 20,314	$ 20,543
Well-Capitalized Ratio, Tier 1 leverage capital	[1]	5.00%	5.00%
Actual Ratio, Tier 1 leverage capital		11.00%	12.00%
Supplementary Leverage Ratio [Abstract]
Capital Amount, Supplementary Leverage Ratio		$ 20,314	$ 20,543
Well-capitalized Ratio, Supplementary Leverage Ratio	[1],[3]	3.00%	3.00%
Actual Ratio, Supplementary Leverage Ratio		8.00%	8.40%
Risk weighted assets:
Risk Weighted Assets	[4]	$ 127,499	$ 118,618
Adjusted Quarterly Average Assets [Abstract]
Adjusted quarterly average assets	[5]	184,851	170,722
Total Leverage Exposure [Abstract]
Total leverage exposure	[6]	$ 254,907	$ 244,008
[1]	HSBC USA and HSBC Bank USA are categorized as "well-capitalized," as defined by their principal regulators. To be categorized as well-capitalized under regulatory guidelines, a banking institution must have the ratios reflected in the above table, and must not be subject to a directive, order, or written agreement to meet and maintain specific capital levels.
[2]	There are no common equity Tier 1 or Tier 1 leverage ratio components in the definition of a well-capitalized bank holding company. The ratios shown are the regulatory minimums.
[3]	There is no SLR component in the definition of a well-capitalized banking institution. The ratios shown are the regulatory minimum ratios.
[4]	Calculated using the generally-applicable Standardized Approach.
[5]	Represents the Tier 1 leverage ratio denominator which reflects quarterly average assets adjusted for amounts permitted to be deducted from Tier 1 capital.
[6]	Represents the SLR denominator which includes adjusted quarterly average assets plus certain off-balance sheet exposures.

Variable Interest Entities - Su

Variable Interest Entities - Summary of Assets and Liabilities Related to Consolidated Variable Interest Entities (Details) - USD ($) $ in Millions		Mar. 31, 2020		Dec. 31, 2019		Mar. 31, 2019
Variable Interest Entity [Line Items]
Total assets		$ 205,077	[1]	$ 175,375	[1]	$ 180,921
Liabilities	[1]	186,758		157,119
Variable interest entities [Member]
Variable Interest Entity [Line Items]
Total assets		131		98
Liabilities		32		38
Low Income Housing Limited Liability Partnership [Member] | Variable interest entities [Member]
Variable Interest Entity [Line Items]
Total assets		92		98
Liabilities		31		38
Low Income Housing Limited Liability Partnership [Member] | Variable interest entities [Member] | Other assets [Member]
Variable Interest Entity [Line Items]
Total assets		92		98
Low Income Housing Limited Liability Partnership [Member] | Variable interest entities [Member] | Interest, taxes and other liabilities [Member]
Variable Interest Entity [Line Items]
Liabilities		31		38
Venture Debt Financing Entity [Member] | Variable interest entities [Member]
Variable Interest Entity [Line Items]
Total assets		39		0
Liabilities		1		0
Venture Debt Financing Entity [Member] | Variable interest entities [Member] | Interest, taxes and other liabilities [Member]
Variable Interest Entity [Line Items]
Liabilities		1		0
Venture Debt Financing Entity [Member] | Variable interest entities [Member] | Loans [Member]
Variable Interest Entity [Line Items]
Total assets		$ 39		$ 0
[1]	The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at March 31, 2020 and December 31, 2019 which are consolidated on our balance sheet. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 17, "Variable Interest Entities," for additional information. Assets: Loans $39 million and $0 million. Other assets $92 million and $98 million. Total assets $131 million and $98 million respectively. Liabilities: Interest, taxes and other liabilities $32 million and $38 million. Total liabilities $32 million and $38 million, respectively.

Variable Interest Entities - Va

Variable Interest Entities - Variable Interests Held by Us and Our Maximum Exposure to Loss Rising From Our Involvements in Those VIEs (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Total Assets Held by Unconsolidated VIEs	$ 3,806	$ 3,684
Variable Interest Held Classified as Assets	1,101	1,071
Variable Interests Held Classified as Liabilities	449	309
Maximum Exposure to Loss	2,106	2,077
Structured note vehicles [Member]
Variable Interest Entity [Line Items]
Total Assets Held by Unconsolidated VIEs	1,657	1,524
Variable Interest Held Classified as Assets	510	510
Variable Interests Held Classified as Liabilities	142	9
Maximum Exposure to Loss	1,515	1,515
Limited partnership investments [Member]
Variable Interest Entity [Line Items]
Total Assets Held by Unconsolidated VIEs	2,149	2,160
Variable Interest Held Classified as Assets	591	561
Variable Interests Held Classified as Liabilities	307	300
Maximum Exposure to Loss	$ 591	$ 562

Variable Interest Entities - Ad

Variable Interest Entities - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2020	Dec. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Maximum exposure to loss		$ 2,106	$ 2,077
Carrying value of structured note vehicle		3,806	3,684
Structured note vehicles [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Maximum exposure to loss		1,515	1,515
Loss on structured note settlement	$ 39
Carrying value of structured note vehicle		$ 1,657	$ 1,524
Trading Assets [Member] | Structured note vehicles [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Carrying value of structured note vehicle	$ 1,293

Guarantee Arrangements, Pledg_3

Guarantee Arrangements, Pledged Assets and Repurchase Agreements - Carrying Value and Contractual Amounts of our Sell Protection Credit Derivatives and Major Off-Balance Sheet Guarantee Arrangements (Detail) - USD ($) $ in Millions		Mar. 31, 2020		Dec. 31, 2019
Guarantor Obligations [Line Items]
Carrying Value		$ (2,064)		$ (63)
Notional/maximum exposure to loss		50,528	[1]	48,175
Credit derivatives [Member]
Guarantor Obligations [Line Items]
Carrying Value	[2],[3]	(2,064)		(63)
Notional/maximum exposure to loss	[2],[3]	41,036		38,739
Financial standby letters of credit, net of participations [Member]
Guarantor Obligations [Line Items]
Carrying Value	[4],[5]	0		0
Notional/maximum exposure to loss	[4],[5]	5,805		5,657
Performance standby letters of credit, net of participations [Member]
Guarantor Obligations [Line Items]
Carrying Value	[4],[5]	0		0
Notional/maximum exposure to loss	[4],[5]	3,687		3,779
Affiliated Entity [Member] | Credit derivatives [Member]
Guarantor Obligations [Line Items]
Notional/maximum exposure to loss		19,399		18,391
Affiliated Entity [Member] | Financial and performance standby letters of credit [Member]
Guarantor Obligations [Line Items]
Notional/maximum exposure to loss		$ 1,649		$ 1,623
[1]	External ratings for most of the obligors are not available. Presented above are the internal credit ratings which are developed using similar methodologies and rating scale equivalent to external credit ratings for purposes of classification as investment grade and non-investment grade.
[2]	For credit derivatives, the maximum loss is represented by the notional amounts without consideration of mitigating effects from collateral or recourse arrangements.
[3]	Includes $19,399 million and $18,391 million of notional issued for the benefit of HSBC affiliates at March 31, 2020 and December 31, 2019, respectively.
[4]	For standby letters of credit, maximum loss represents losses to be recognized assuming the letters of credit have been fully drawn and the obligors have defaulted with zero recovery.
[5]	Includes $1,649 million and $1,623 million of both financial and performance standby letters of credit issued for the benefit of HSBC affiliates at March 31, 2020 and December 31, 2019, respectively.

Guarantee Arrangements, Pledg_4

Guarantee Arrangements, Pledged Assets and Repurchase Agreements - Net Credit Derivative Positions (Detail) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Credit Derivatives [Line Items]
Net position, Carrying/Fair Value	[1]	$ (281)	$ 14
Notional	[1]	13,292	12,571
Sell-protection credit derivative positions [Member]
Credit Derivatives [Line Items]
Carrying/Fair Value		(2,064)	(63)
Notional		41,036	38,739
Buy-protection credit derivative positions [Member]
Credit Derivatives [Line Items]
Carrying/Fair Value		1,783	77
Notional		$ 54,328	$ 51,310
[1]	Positions are presented net in the table above to provide a complete analysis of our risk exposure and depict the way we manage our credit derivative portfolio. The offset of the sell-protection credit derivatives against the buy-protection credit derivatives may not be legally binding in the absence of master netting agreements with the same counterparty. Furthermore, the credit loss triggering events for individual sell protection credit derivatives may not be the same or occur in the same period as those of the buy protection credit derivatives thereby not providing an exact offset.

Guarantee Arrangements, Pledg_5

Guarantee Arrangements, Pledged Assets and Repurchase Agreements - Additional Information (Detail) - USD ($) $ in Millions		36 Months Ended
		Dec. 31, 2007	Mar. 31, 2020	Dec. 31, 2019
Guarantor Obligations [Line Items]
Deferred fees			$ 3	$ 2
Carrying value of swap			4,613,258	4,807,851
Pledged assets not separately reported, trading assets	[1]		6,633	525
Collateral accepted under security resale agreements, fair value			8,324	19,174
Collateral accepted under security repurchase agreements but not reported on the balance sheet that can be sold or repledged, fair value			7,199	18,199
Collateral accepted under security repurchase agreements that has been sold or repledged under repurchase agreements or to cover short sales			1,853	2,062
HSBC Securities [Member]
Guarantor Obligations [Line Items]
Whole loan securitization		$ 24,000
Securities available-for-sale [Member]
Guarantor Obligations [Line Items]
Securities pledged as collateral that can be sold or repledged by the secured party, fair value			7,760	0
Trading assets [Member]
Guarantor Obligations [Line Items]
Pledged assets not separately reported, trading assets			6,633	336
Other liabilities [Member]
Guarantor Obligations [Line Items]
Allowance for credit losses on unfunded standby letters of credit			44	26
Other liabilities [Member] | Standby Letters of Credit [Member]
Guarantor Obligations [Line Items]
Deferred fees			52	52
Swap [Member]
Guarantor Obligations [Line Items]
Carrying value of swap			67	85
Mortgage Securitization Activity Related Litigation [Member] | HSBC Securities [Member]
Guarantor Obligations [Line Items]
Mortgage securitization outstanding loan purchase and sold			$ 3,400	$ 3,400
[1]	Trading assets are primarily pledged against liabilities associated with repurchase agreements.

Guarantee Arrangements, Pledg_6

Guarantee Arrangements, Pledged Assets and Repurchase Agreements - Summary of Credit Ratings of Credit Risk Related Guarantees (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020		Dec. 31, 2019
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions		$ 50,528	[1]	$ 48,175
Sell Protection Credit Derivatives [Member]
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions		$ 41,036
Single name credit default swap [Member] | Sell Protection Credit Derivatives [Member]
Credit Derivatives [Line Items]
Average Life in years	[2]	3 years 1 month 26 days
Credit Ratings of the Obligors or the Transactions	[2]	$ 29,321
Index credit derivatives [Member] | Sell Protection Credit Derivatives [Member]
Credit Derivatives [Line Items]
Average Life in years	[2]	4 years 3 months 19 days
Credit Ratings of the Obligors or the Transactions	[2]	$ 10,459
Total return swaps [Member] | Sell Protection Credit Derivatives [Member]
Credit Derivatives [Line Items]
Average Life in years	[2]	2 years 4 months 5 days
Credit Ratings of the Obligors or the Transactions	[2]	$ 1,256
Standby Letters of Credit [Member]
Credit Derivatives [Line Items]
Average Life in years	[1]	1 year 2 months 14 days
Credit Ratings of the Obligors or the Transactions	[1]	$ 9,492
External Credit Rating, Investment Grade [Member]
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions	[1]	35,050
External Credit Rating, Investment Grade [Member] | Sell Protection Credit Derivatives [Member]
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions		27,452
External Credit Rating, Investment Grade [Member] | Single name credit default swap [Member] | Sell Protection Credit Derivatives [Member]
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions	[2]	20,231
External Credit Rating, Investment Grade [Member] | Index credit derivatives [Member] | Sell Protection Credit Derivatives [Member]
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions	[2]	6,159
External Credit Rating, Investment Grade [Member] | Total return swaps [Member] | Sell Protection Credit Derivatives [Member]
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions	[2]	1,062
External Credit Rating, Investment Grade [Member] | Standby Letters of Credit [Member]
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions	[1]	7,598
External Credit Rating, Non Investment Grade [Member]
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions	[1]	15,478
External Credit Rating, Non Investment Grade [Member] | Sell Protection Credit Derivatives [Member]
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions		13,584
External Credit Rating, Non Investment Grade [Member] | Single name credit default swap [Member] | Sell Protection Credit Derivatives [Member]
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions	[2]	9,090
External Credit Rating, Non Investment Grade [Member] | Index credit derivatives [Member] | Sell Protection Credit Derivatives [Member]
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions	[2]	4,300
External Credit Rating, Non Investment Grade [Member] | Total return swaps [Member] | Sell Protection Credit Derivatives [Member]
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions	[2]	194
External Credit Rating, Non Investment Grade [Member] | Standby Letters of Credit [Member]
Credit Derivatives [Line Items]
Credit Ratings of the Obligors or the Transactions	[1]	$ 1,894
[1]	External ratings for most of the obligors are not available. Presented above are the internal credit ratings which are developed using similar methodologies and rating scale equivalent to external credit ratings for purposes of classification as investment grade and non-investment grade.
[2]	The credit ratings in the table represent external credit ratings for classification as investment grade and non-investment grade.

Guarantee Arrangements, Pledg_7

Guarantee Arrangements, Pledged Assets and Repurchase Agreements - Summary of Change in Estimated Repurchase Liability for Loans Sold to GSEs and Other Third Parties (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Loss Contingencies [Line Items]
Estimate of possible losses in excess of recorded liability	$ 225,000,000
Obligation to Repurchase Receivables Sold [Member]
Loss Contingencies [Line Items]
Changes in estimated repurchase liability	0	$ 0
Repurchase liability	4,000,000
Minimum [Member] | Obligation to Repurchase Receivables Sold [Member]
Loss Contingencies [Line Items]
Estimate of possible losses in excess of recorded liability	0
Maximum [Member] | Obligation to Repurchase Receivables Sold [Member]
Loss Contingencies [Line Items]
Estimate of possible losses in excess of recorded liability	$ 25,000,000

Guarantee Arrangements, Pledg_8

Guarantee Arrangements, Pledged Assets and Repurchase Agreements - Summary of Pledged Assets Included in Consolidated Balance Sheet (Detail) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Interest bearing deposits with banks		$ 4,816	$ 2,682
Trading assets	[1]	6,633	525
Securities available-for-sale	[2]	14,986	6,814
Securities held to maturity	[2]	1,573	1,688
Loans	[3]	13,316	14,342
Other assets	[4]	6,634	3,517
Total		$ 47,958	$ 29,568
[1]	Trading assets are primarily pledged against liabilities associated with repurchase agreements.
[2]	Securities are primarily pledged against derivatives, public fund deposits, trust deposits and various short-term and long term borrowings, as well as providing capacity for potential secured borrowings from the FHLB and the Federal Reserve Bank of New York.
[3]	Loans are primarily residential mortgage loans pledged against current and potential borrowings from the FHLB and the Federal Reserve Bank of New York.
[4]	Other assets represent cash on deposit with non-banks related to derivative collateral support agreements.

Guarantee Arrangements and Pled

Guarantee Arrangements and Pledged Assets and Repurchase Agreements - Offsetting of Resale and Repurchase Agreements and Securities Borrowing and Lending Agreements (Details) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Securities purchased under agreements to resell, Gross Amounts Recognized		$ 8,241	$ 19,167
Securities purchased under agreements to resell, Gross Amounts Offset in the Balance Sheet	[1]	3,598	1,329
Securities Purchased under Agreements to Resell		4,643	17,838
Securities purchased under agreements to resell, Gross Amounts Not Offset in the Balance Sheet, Financial Instruments	[2]	4,641	17,832
Securities purchased under agreements to resell, Gross Amounts Not Offset in the Balance Sheet, Cash Collateral Receive / Pledged		0	0
Securities purchased under agreements to resell, Net amount	[3]	2	6
Securities sold under repurchase agreements, Gross Amounts Recognized		16,096	2,401
Securities sold under repurchase agreements, Gross Amounts Offset in the Balance Sheet	[1]	3,598	1,329
Securities sold under repurchase agreements, Net Amounts Presented in the Balance Sheet		12,498	1,072
Securities sold under repurchase agreements, Gross Amounts Not Offset in the Balance sheet, Financial Instruments	[2]	12,453	1,068
Securities sold under repurchase agreements, Gross Amounts Not Offset in the Balance Sheet, Cash Collateral Received / Pledged		0	0
Securities sold under repurchase agreements, Net amount	[3]	$ 45	$ 4
[1]	Represents recognized amount of resale and repurchase agreements with counterparties subject to legally enforceable netting agreements that meet the applicable netting criteria as permitted by generally accepted accounting principles.
[2]	Represents securities received or pledged to cover financing transaction exposures.
[3]	Represents the amount of our exposure that is not collateralized / covered by pledged collateral.

Guarantee Arrangements, Pledg_9

Guarantee Arrangements, Pledged Assets and Repurchase Agreements, Collateral Pledged and Remaining Contractual Maturity of Repurchase Agreements Accounted for as Secured Borrowings (Details) - U.S. Treasury, U.S. Government agencies and sponsored entities [Member] - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings	$ 16,096	$ 2,401
Maturity Overnight and Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings	6,719	2,401
Maturity up to 30 Days [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings	6,148	0
Maturity 31 to 90 Days [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings	3,229	0
Maturity 91 Days to One Year [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings	0	0
Maturity Greater than One Year [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings	$ 0	$ 0

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Recorded at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions		Mar. 31, 2020		Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Netting, Assets	[1],[2]	$ (48,099)		$ (29,510)
Netting Liabilities	[1],[2]	(48,099)		(29,510)
Trading assets		29,217		28,452
Trading liabilities		3,923		3,235
Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading assets		1,432		5,693
Precious metals [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading assets		4,604		1,909
Trading liabilities		0		124
Derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading liabilities		3,489		1,929
Derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading assets		5,393		3,055
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		124,921		97,866
Netting, Assets	[3]	(54,277)		(33,193)
Net Balance, Assets		70,644		64,673
Gross Balance, Liabilities		76,128		55,224
Netting Liabilities	[3]	(57,230)		(33,900)
Net Balance, Liabilities		18,898		21,324
Fair Value, Recurring [Member] | Domestic Deposits [Member] | Domestic Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	6,371		7,209
Net Balance, Liabilities	[4]	6,371		7,209
Fair Value, Recurring [Member] | Trading liabilities, excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities		434		1,306
Net Balance, Liabilities		434		1,306
Fair Value, Recurring [Member] | Derivative financial liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	60,948		35,989
Netting Liabilities	[3],[5]	(57,230)		(33,900)
Net Balance, Liabilities	[5]	3,718		2,089
Fair Value, Recurring [Member] | Derivative financial liabilities [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	22,492		13,573
Netting Liabilities	[3],[5]	0		0
Net Balance, Liabilities	[5]	22,492		13,573
Fair Value, Recurring [Member] | Derivative financial liabilities [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	29,744		15,806
Netting Liabilities	[3],[5]	0		0
Net Balance, Liabilities	[5]	29,744		15,806
Fair Value, Recurring [Member] | Derivative financial liabilities [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	4,130		4,068
Netting Liabilities	[3],[5]	0		0
Net Balance, Liabilities	[5]	4,130		4,068
Fair Value, Recurring [Member] | Derivative financial liabilities [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	2,187		1,389
Netting Liabilities	[3],[5]	0		0
Net Balance, Liabilities	[5]	2,187		1,389
Fair Value, Recurring [Member] | Derivative financial liabilities [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	2,328		1,068
Netting Liabilities	[3],[5]	0		0
Net Balance, Liabilities	[5]	2,328		1,068
Fair Value, Recurring [Member] | Derivative financial liabilities [Member] | Other Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	67	[4]	85	[6]
Netting Liabilities	[3],[5]	0		0	[6]
Net Balance, Liabilities	[5]	67	[4]	85	[6]
Fair Value, Recurring [Member] | Derivative financial liabilities [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	0		0
Netting Liabilities	[3],[5]	(57,230)		(33,900)
Net Balance, Liabilities	[5]	(57,230)		(33,900)
Fair Value, Recurring [Member] | Short-term borrowings [Member] | Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]			373
Net Balance, Liabilities	[4]			373
Fair Value, Recurring [Member] | Long-term Debt [Member] | Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	8,375		10,347
Net Balance, Liabilities	[4]	8,375		10,347
Fair Value, Recurring [Member] | Trading assets, excluding derivatives [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		8,267		6,801
Net Balance, Assets		8,267		6,801
Fair Value, Recurring [Member] | Trading assets, excluding derivatives [Member] | Collateralized debt obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		67		71
Net Balance, Assets		67		71
Fair Value, Recurring [Member] | Trading assets, excluding derivatives [Member] | Residential mortgage asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		16		17
Net Balance, Assets		16		17
Fair Value, Recurring [Member] | Trading assets, excluding derivatives [Member] | Student loan asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		73		80
Net Balance, Assets		73		80
Fair Value, Recurring [Member] | Trading assets, excluding derivatives [Member] | Corporate and other domestic debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		465		510
Net Balance, Assets		465		510
Fair Value, Recurring [Member] | Trading assets, excluding derivatives [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		8,900		10,316
Net Balance, Assets		8,900		10,316
Fair Value, Recurring [Member] | Trading assets, excluding derivatives [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		1,432		5,693
Net Balance, Assets		1,432		5,693
Fair Value, Recurring [Member] | Trading assets, excluding derivatives [Member] | Precious metals [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		4,604		1,909
Net Balance, Assets		4,604		1,909
Fair Value, Recurring [Member] | Derivative financial assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	59,784		36,345
Netting, Assets	[3],[5]	(54,277)		(33,193)
Net Balance, Assets	[5]	5,507		3,152
Fair Value, Recurring [Member] | Derivative financial assets [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	19,842		12,395
Netting, Assets	[3],[5]	0		0
Net Balance, Assets	[5]	19,842		12,395
Fair Value, Recurring [Member] | Derivative financial assets [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	31,125		16,536
Netting, Assets	[3],[5]	0		0
Net Balance, Assets	[5]	31,125		16,536
Fair Value, Recurring [Member] | Derivative financial assets [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	4,606		5,107
Netting, Assets	[3],[5]	0		0
Net Balance, Assets	[5]	4,606		5,107
Fair Value, Recurring [Member] | Derivative financial assets [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	2,211		1,158
Netting, Assets	[3],[5]	0		0
Net Balance, Assets	[5]	2,211		1,158
Fair Value, Recurring [Member] | Derivative financial assets [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	1,991		1,139
Netting, Assets	[3],[5]	0		0
Net Balance, Assets	[5]	1,991		1,139
Fair Value, Recurring [Member] | Derivative financial assets [Member] | Other Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5],[6]	9		10
Netting, Assets	[3],[5],[6]	0		0
Net Balance, Assets	[5],[6]	9		10
Fair Value, Recurring [Member] | Derivative financial assets [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	0		0
Netting, Assets	[3],[5]	(54,277)		(33,193)
Net Balance, Assets	[5]	(54,277)		(33,193)
Fair Value, Recurring [Member] | Securities available-for-sale [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	36,417		32,234
Net Balance, Assets	[7]	36,417		32,234
Fair Value, Recurring [Member] | Securities available-for-sale [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	4,231		3,286
Net Balance, Assets	[7]	4,231		3,286
Fair Value, Recurring [Member] | Securities available-for-sale [Member] | Home equity [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	28		32
Net Balance, Assets	[7]	28		32
Fair Value, Recurring [Member] | Securities available-for-sale [Member] | Other asset-backed securities available-for-sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	116		111
Net Balance, Assets	[7]	116		111
Fair Value, Recurring [Member] | Loans [Member] | Student Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	37
Net Balance, Assets	[4]	37
Fair Value, Recurring [Member] | Loans [Member] | Loans Held For Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	206		178
Net Balance, Assets	[4]	206		178
Fair Value, Recurring [Member] | Other assets [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		147		147
Net Balance, Assets		147		147
Fair Value, Recurring [Member] | Other assets [Member] | Equity Securities Measured at Net Asset Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[8]	131		136
Net Balance, Assets	[8]	131		136
Fair Value, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		44,492		43,501
Gross Balance, Liabilities		594		1,265
Fair Value, Recurring [Member] | Level 1 [Member] | Domestic Deposits [Member] | Domestic Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Trading liabilities, excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities		429		1,182
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	165		83
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial liabilities [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	11		3
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial liabilities [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	7		0
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial liabilities [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial liabilities [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	147		80
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial liabilities [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial liabilities [Member] | Other Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	0	[4]	0	[6]
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial liabilities [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Short-term borrowings [Member] | Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]			0
Fair Value, Recurring [Member] | Level 1 [Member] | Long-term Debt [Member] | Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Trading assets, excluding derivatives [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		8,207		6,763
Fair Value, Recurring [Member] | Level 1 [Member] | Trading assets, excluding derivatives [Member] | Collateralized debt obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Trading assets, excluding derivatives [Member] | Residential mortgage asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Trading assets, excluding derivatives [Member] | Student loan asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Trading assets, excluding derivatives [Member] | Corporate and other domestic debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Trading assets, excluding derivatives [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		8,803		10,095
Fair Value, Recurring [Member] | Level 1 [Member] | Trading assets, excluding derivatives [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		1,432		5,693
Fair Value, Recurring [Member] | Level 1 [Member] | Trading assets, excluding derivatives [Member] | Precious metals [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	13		260
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial assets [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	11		110
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial assets [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	0		80
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial assets [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	1		0
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial assets [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	1		70
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial assets [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial assets [Member] | Other Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5],[6]	0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Derivative financial assets [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Securities available-for-sale [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	21,844		17,532
Fair Value, Recurring [Member] | Level 1 [Member] | Securities available-for-sale [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	4,193		3,158
Fair Value, Recurring [Member] | Level 1 [Member] | Securities available-for-sale [Member] | Home equity [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Securities available-for-sale [Member] | Other asset-backed securities available-for-sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Loans [Member] | Student Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	0
Fair Value, Recurring [Member] | Level 1 [Member] | Loans [Member] | Loans Held For Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Other assets [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 1 [Member] | Other assets [Member] | Equity Securities Measured at Net Asset Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[8]	0		0
Fair Value, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		79,073		53,304
Gross Balance, Liabilities		73,964		52,609
Fair Value, Recurring [Member] | Level 2 [Member] | Domestic Deposits [Member] | Domestic Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	5,718		6,435
Fair Value, Recurring [Member] | Level 2 [Member] | Trading liabilities, excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities		5		124
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	60,237		35,684
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial liabilities [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	22,481		13,570
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial liabilities [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	29,732		15,805
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial liabilities [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	3,909		3,955
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial liabilities [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	2,040		1,306
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial liabilities [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	2,075		1,048
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial liabilities [Member] | Other Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	0	[4]	0	[6]
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial liabilities [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	0		0
Fair Value, Recurring [Member] | Level 2 [Member] | Short-term borrowings [Member] | Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]			373
Fair Value, Recurring [Member] | Level 2 [Member] | Long-term Debt [Member] | Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	8,004		9,993
Fair Value, Recurring [Member] | Level 2 [Member] | Trading assets, excluding derivatives [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		60		38
Fair Value, Recurring [Member] | Level 2 [Member] | Trading assets, excluding derivatives [Member] | Collateralized debt obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		67		71
Fair Value, Recurring [Member] | Level 2 [Member] | Trading assets, excluding derivatives [Member] | Residential mortgage asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 2 [Member] | Trading assets, excluding derivatives [Member] | Student loan asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		73		80
Fair Value, Recurring [Member] | Level 2 [Member] | Trading assets, excluding derivatives [Member] | Corporate and other domestic debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 2 [Member] | Trading assets, excluding derivatives [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		97		221
Fair Value, Recurring [Member] | Level 2 [Member] | Trading assets, excluding derivatives [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 2 [Member] | Trading assets, excluding derivatives [Member] | Precious metals [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		4,604		1,909
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	59,143		35,798
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial assets [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	19,790		12,275
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial assets [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	31,123		16,456
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial assets [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	4,380		4,922
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial assets [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	2,210		1,085
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial assets [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	1,640		1,060
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial assets [Member] | Other Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5],[6]	0		0
Fair Value, Recurring [Member] | Level 2 [Member] | Derivative financial assets [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	0		0
Fair Value, Recurring [Member] | Level 2 [Member] | Securities available-for-sale [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	14,573		14,702
Fair Value, Recurring [Member] | Level 2 [Member] | Securities available-for-sale [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	38		128
Fair Value, Recurring [Member] | Level 2 [Member] | Securities available-for-sale [Member] | Home equity [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	28		32
Fair Value, Recurring [Member] | Level 2 [Member] | Securities available-for-sale [Member] | Other asset-backed securities available-for-sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	0		0
Fair Value, Recurring [Member] | Level 2 [Member] | Loans [Member] | Student Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	37
Fair Value, Recurring [Member] | Level 2 [Member] | Loans [Member] | Loans Held For Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	206		178
Fair Value, Recurring [Member] | Level 2 [Member] | Other assets [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		147		147
Fair Value, Recurring [Member] | Level 2 [Member] | Other assets [Member] | Equity Securities Measured at Net Asset Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[8]	0		0
Fair Value, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		1,225		925
Gross Balance, Liabilities		1,570		1,350
Fair Value, Recurring [Member] | Level 3 [Member] | Domestic Deposits [Member] | Domestic Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	653		774
Fair Value, Recurring [Member] | Level 3 [Member] | Trading liabilities, excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities		0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	546		222
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial liabilities [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial liabilities [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	5		1
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial liabilities [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	221		113
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial liabilities [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	0		3
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial liabilities [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	253		20
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial liabilities [Member] | Other Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	67	[4]	85	[6]
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial liabilities [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[5]	0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Short-term borrowings [Member] | Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]			0
Fair Value, Recurring [Member] | Level 3 [Member] | Long-term Debt [Member] | Long-term debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	371		354
Fair Value, Recurring [Member] | Level 3 [Member] | Trading assets, excluding derivatives [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Trading assets, excluding derivatives [Member] | Collateralized debt obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Trading assets, excluding derivatives [Member] | Residential mortgage asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		16		17
Fair Value, Recurring [Member] | Level 3 [Member] | Trading assets, excluding derivatives [Member] | Student loan asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Trading assets, excluding derivatives [Member] | Corporate and other domestic debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		465		510
Fair Value, Recurring [Member] | Level 3 [Member] | Trading assets, excluding derivatives [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Trading assets, excluding derivatives [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Trading assets, excluding derivatives [Member] | Precious metals [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	628		287
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial assets [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	41		10
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial assets [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	2		0
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial assets [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	225		185
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial assets [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	0		3
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial assets [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	351		79
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial assets [Member] | Other Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5],[6]	9		10
Fair Value, Recurring [Member] | Level 3 [Member] | Derivative financial assets [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[5]	0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Securities available-for-sale [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Securities available-for-sale [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Securities available-for-sale [Member] | Home equity [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Securities available-for-sale [Member] | Other asset-backed securities available-for-sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	116		111
Fair Value, Recurring [Member] | Level 3 [Member] | Loans [Member] | Student Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	0
Fair Value, Recurring [Member] | Level 3 [Member] | Loans [Member] | Loans Held For Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Other assets [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Other assets [Member] | Equity Securities Measured at Net Asset Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[8]	$ 0		$ 0
[1]	Netting is performed at a counterparty level in cases where enforceable master netting agreements are in place, regardless of the type of derivative instrument. Therefore, we have not allocated netting to the different types of derivative instruments shown in the table above.
[2]	Represents the netting of derivative receivable and payable balances for the same counterparty under enforceable netting agreements.
[3]	Represents counterparty and cash collateral netting which allow the offsetting of amounts relating to certain contracts if certain conditions are met.
[4]	See Note 10, "Fair Value Option," for additional information. Excluding the fair value movement on fair value option liabilities attributable to our own credit spread, which is recorded in other comprehensive income, fair value option assets and liabilities are recorded at fair value through net income (loss).
[5]	Includes trading derivative assets of $5,393 million and $3,055 million and trading derivative liabilities of $3,489 million and $1,929 million at March 31, 2020 and December 31, 2019, respectively, as well as derivatives held for hedging and commitments accounted for as derivatives. See Note 9, "Derivative Financial Instruments," for additional information. Excluding changes in fair value of a derivative instrument associated with a qualifying cash flow hedge, which are recognized initially in other comprehensive income, derivative assets and liabilities are recorded at fair value through net income (loss).
[6]	Consists of swap agreements entered into in conjunction with the sales of Visa Class B Shares.
[7]	Securities available-for-sale are recorded at fair value through other comprehensive income.
[8]	Investments that are measured at fair value using the net asset value per share practical expedient have not been classified in the fair value hierarchy.

Fair Value Measurements - Chang

Fair Value Measurements - Changes in Fair Value of Level 3 Assets and Liabilities (Detail) - Level 3 [Member] - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020		Mar. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Assets, Beginning Balance		$ 703		$ 2,088
Fair Value Assets, Gains (Losses) Included In Earnings		(45)		39
Fair Value Assets, Gains (Losses) Included in Other Comprehensive Income		5		2
Fair Value Assets, Purchases		0		0
Fair Value Assets, Issuances		0		0
Fair Value Assets, Settlements		16		(1,260)
Fair Value Assets, Transfers Into Level 3		0		0
Fair Value Assets, Transfers Out of Level 3		0		1
Fair Value Assets, Ending Balance		679		870
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Earnings		30		77	[1]
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income , Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	[1]	5		2
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Liability, Beginning Balance		(1,128)		(1,337)
Fair Value Liability, Gains (Losses) Included In Earnings		6		(57)
Fair Value, Liability, Gains (Losses) Included in Other Comprehensive Income		28		(8)
Fair Value Liability, Purchases		0		0
Fair Value Liability, Issuances		(137)		(127)
Fair Value Liability, Settlements		170		58
Fair Value Liability, Transfers Into Level 3		0		0
Fair Value Liability, Transfers Out of Level 3		37		69
Fair Value Liability, Ending Balance		(1,024)		(1,402)
Fair Value Liability, Current Period Unrealized Gains (Losses) Included in Earnings		4		(149)	[2]
Fair Value Liability, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income	[2]	28		(8)
Interest rate contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivatives, net, Beginning Balance	[3]	10		2
Derivatives, net, Gains (Losses) included in Earnings	[3]	31		5
Derivatives, net, Gains (Losses) included in Other Comprehensive Income	[3]	0		0
Derivatives, net, Purchases	[3]	0		0
Derivatives, net, Issuances	[3]	0		0
Derivatives, net, Settlements	[3]	0		0
Derivatives, net, Transfers into Level 3	[3]	0		0
Derivatives, net, Transfers out of Level 3	[3]	0		0
Derivatives, net, Ending Balance	[3]	41		7
Derivatives, net, Current Period Unrealized Gains (Losses) Included in Earnings	[3]	31		5
Derivatives, net, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income	[3]	0		0
Foreign exchange contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivatives, net, Beginning Balance	[3]	(1)	[4]	(1)
Derivatives, net, Gains (Losses) included in Earnings	[3]	(2)		0
Derivatives, net, Gains (Losses) included in Other Comprehensive Income	[3]	0		0
Derivatives, net, Purchases	[3]	0		0
Derivatives, net, Issuances	[3]	0		0
Derivatives, net, Settlements	[3]	0		0
Derivatives, net, Transfers into Level 3	[3]	0		0
Derivatives, net, Transfers out of Level 3	[3]	0		0
Derivatives, net, Ending Balance	[3]	(3)	[4]	(1)
Derivatives, net, Current Period Unrealized Gains (Losses) Included in Earnings	[3]	(2)		0
Derivatives, net, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income	[3]	0		0
Equity contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivatives, net, Beginning Balance	[3]	72	[4]	(52)
Derivatives, net, Gains (Losses) included in Earnings	[3]	(74)		71
Derivatives, net, Gains (Losses) included in Other Comprehensive Income	[3]	0		0
Derivatives, net, Purchases	[3]	0		0
Derivatives, net, Issuances	[3]	0		0
Derivatives, net, Settlements	[3]	6		4
Derivatives, net, Transfers into Level 3	[3]	0		0
Derivatives, net, Transfers out of Level 3	[3]	0		1
Derivatives, net, Ending Balance	[3]	4	[4]	24
Derivatives, net, Current Period Unrealized Gains (Losses) Included in Earnings	[3]	12		75
Derivatives, net, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income	[3]	0		0
Credit contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivatives, net, Beginning Balance	[3]	59		52
Derivatives, net, Gains (Losses) included in Earnings	[3]	35		(37)
Derivatives, net, Gains (Losses) included in Other Comprehensive Income	[3]	0		0
Derivatives, net, Purchases	[3]	0		0
Derivatives, net, Issuances	[3]	0		0
Derivatives, net, Settlements	[3]	4		38
Derivatives, net, Transfers into Level 3	[3]	0		0
Derivatives, net, Transfers out of Level 3	[3]	0		0
Derivatives, net, Ending Balance	[3]	98		53
Derivatives, net, Current Period Unrealized Gains (Losses) Included in Earnings	[3]	35		0
Derivatives, net, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income	[3]	0		0
Other Contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Derivatives, net, Beginning Balance	[3]	(75)		(35)
Derivatives, net, Gains (Losses) included in Earnings	[3]	11		(6)
Derivatives, net, Gains (Losses) included in Other Comprehensive Income	[3]	0		0
Derivatives, net, Purchases	[3]	0		0
Derivatives, net, Issuances	[3]	0		0
Derivatives, net, Settlements	[3]	6		4
Derivatives, net, Transfers into Level 3	[3]	0		0
Derivatives, net, Transfers out of Level 3	[3]	0		0
Derivatives, net, Ending Balance	[3]	(58)		(37)
Derivatives, net, Current Period Unrealized Gains (Losses) Included in Earnings	[3]	0		0
Derivatives, net, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income	[3]	0		0
Other assets [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Assets, Beginning Balance	[5]			4
Fair Value Assets, Gains (Losses) Included In Earnings	[5]			0
Fair Value Assets, Gains (Losses) Included in Other Comprehensive Income	[5]			0
Fair Value Assets, Purchases	[5]			0
Fair Value Assets, Issuances	[5]			0
Fair Value Assets, Settlements	[5]			0
Fair Value Assets, Transfers Into Level 3	[5]			0
Fair Value Assets, Transfers Out of Level 3	[5]			0
Fair Value Assets, Ending Balance	[5]			4
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Earnings	[1]			0
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income , Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	[1]			0
Collateralized debt obligations [Member] | Trading assets, excluding derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Assets, Beginning Balance	[1]			100
Fair Value Assets, Gains (Losses) Included In Earnings	[1]			1
Fair Value Assets, Gains (Losses) Included in Other Comprehensive Income	[1]			0
Fair Value Assets, Purchases	[1]			0
Fair Value Assets, Issuances	[1]			0
Fair Value Assets, Settlements	[1]			(11)
Fair Value Assets, Transfers Into Level 3	[1]			0
Fair Value Assets, Transfers Out of Level 3	[1]			0
Fair Value Assets, Ending Balance	[1]			90
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Earnings	[1]			(6)
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income , Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	[1]			0
Residential mortgage asset-backed securities [Member] | Trading assets, excluding derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Assets, Beginning Balance		17	[1]	16
Fair Value Assets, Gains (Losses) Included In Earnings	[1]	(1)		0
Fair Value Assets, Gains (Losses) Included in Other Comprehensive Income		0	[1]	0
Fair Value Assets, Purchases		0	[1]	0
Fair Value Assets, Issuances		0	[1]	0
Fair Value Assets, Settlements		0	[1]	0
Fair Value Assets, Transfers Into Level 3		0		0
Fair Value Assets, Transfers Out of Level 3		0	[1]	0
Fair Value Assets, Ending Balance		16	[1]	16
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Earnings	[1]	(1)		0
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income , Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	[1]	0		0
Student loan asset-backed securities [Member] | Trading assets, excluding derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Assets, Beginning Balance				92
Fair Value Assets, Gains (Losses) Included In Earnings	[1]			5
Fair Value Assets, Gains (Losses) Included in Other Comprehensive Income				0
Fair Value Assets, Purchases				0
Fair Value Assets, Issuances				0
Fair Value Assets, Settlements				(2)
Fair Value Assets, Transfers Into Level 3				0
Fair Value Assets, Transfers Out of Level 3				0
Fair Value Assets, Ending Balance				95
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Earnings	[1]			3
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income , Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	[1]			0
Corporate and other domestic debt securities [Member] | Trading assets, excluding derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Assets, Beginning Balance		510		1,803	[1]
Fair Value Assets, Gains (Losses) Included In Earnings	[1]	(45)		0
Fair Value Assets, Gains (Losses) Included in Other Comprehensive Income		0		0	[1]
Fair Value Assets, Purchases		0		0	[1]
Fair Value Assets, Issuances		0		0	[1]
Fair Value Assets, Settlements		0		(1,293)	[1]
Fair Value Assets, Transfers Into Level 3		0		0	[1]
Fair Value Assets, Transfers Out of Level 3		0		0	[1]
Fair Value Assets, Ending Balance		465		510	[1]
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Earnings		(45)		0	[1]
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income , Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	[1]	0		0
Other asset-backed securities available-for-sale [Member] | Available-for-sale securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Assets, Beginning Balance	[6]	111		107
Fair Value Assets, Gains (Losses) Included In Earnings	[6]	0		0
Fair Value Assets, Gains (Losses) Included in Other Comprehensive Income	[6]	5		2
Fair Value Assets, Purchases	[6]	0		0
Fair Value Assets, Issuances	[6]	0		0
Fair Value Assets, Settlements	[6]	0		0
Fair Value Assets, Transfers Into Level 3	[6]	0		0
Fair Value Assets, Transfers Out of Level 3	[6]	0		0
Fair Value Assets, Ending Balance	[6]	116		109
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Earnings		0	[6]	0	[1]
Fair Value Assets, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income , Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	[1]	5		2
Deposits [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Liability, Beginning Balance	[2]	(774)	[4],[7]	(925)
Fair Value Liability, Gains (Losses) Included In Earnings	[2]	1		(29)
Fair Value, Liability, Gains (Losses) Included in Other Comprehensive Income	[2]	18		(5)
Fair Value Liability, Purchases	[2]	0		0
Fair Value Liability, Issuances	[2]	(36)		(96)
Fair Value Liability, Settlements	[2]	105		45
Fair Value Liability, Transfers Into Level 3	[2]	0		0
Fair Value Liability, Transfers Out of Level 3	[2]	33		61
Fair Value Liability, Ending Balance	[2]	(653)	[4],[7]	(949)
Fair Value Liability, Current Period Unrealized Gains (Losses) Included in Earnings	[2]	0		(100)
Fair Value Liability, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income	[2]	18		(5)
Long-term debt [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Liability, Beginning Balance	[2]	(354)	[4],[7]	(412)
Fair Value Liability, Gains (Losses) Included In Earnings	[2]	5		(28)
Fair Value, Liability, Gains (Losses) Included in Other Comprehensive Income	[2]	10		(3)
Fair Value Liability, Purchases	[2]	0		0
Fair Value Liability, Issuances	[2]	(101)		(31)
Fair Value Liability, Settlements	[2]	65		13
Fair Value Liability, Transfers Into Level 3	[2]	0		0
Fair Value Liability, Transfers Out of Level 3	[2]	4		8
Fair Value Liability, Ending Balance	[2]	(371)	[4],[7]	(453)
Fair Value Liability, Current Period Unrealized Gains (Losses) Included in Earnings	[2]	4		(49)
Fair Value Liability, Current Period Unrealized Gains (Losses) Included in Other Comprehensive Income	[2]	$ 10		$ (3)
[1]	Gains (losses) on trading assets, excluding derivatives are included in trading revenue in the consolidated statement of income (loss).
[2]	Excluding unrealized gains (losses) on fair value option liabilities attributable to our own credit spread, which are recorded in other comprehensive income, gains (losses) on fair value option liabilities are included in loss on instruments designated at fair value and related derivatives in the consolidated statement of income (loss).
[3]	Level 3 net derivatives included derivative assets of $628 million and derivative liabilities of $546 million at March 31, 2020 and derivative assets of $288 million and derivative liabilities of $242 million at March 31, 2019. Gains (losses) on derivatives, net are predominantly included in trading revenue and loss on instruments designated at fair value and related derivatives in the consolidated statement of income (loss).
[4]	We are the client-facing entity and we enter into identical but opposite derivatives to transfer the resultant risks to our affiliates. With the exception of counterparty credit risks, we are market neutral. The corresponding intra-group derivatives are presented as equity derivatives and foreign exchange derivatives in the table.
[5]	Represented contingent consideration receivable associated with the sale of a portion of our PB business, which concluded in 2019. Gains (losses) associated with this transaction were included in other income (loss) in the consolidated statement of income (loss).
[6]	Realized gains (losses) on securities available-for-sale are included in other securities gains, net in the consolidated statement of income (loss). Changes in the allowance for credit losses on securities available-for-sale are included in the provision for credit losses in the consolidated statement of income (loss). Unrealized gains (losses) on securities available-for-sale are included in other comprehensive income.
[7]	Structured deposits and structured notes contain embedded derivative features whose fair value measurements contain significant Level 3 inputs. See equity and foreign exchange derivatives below for a discussion of the uncertainty of Level 3 inputs related to structured deposits and structured notes.

Fair Value Measurements - Quant

Fair Value Measurements - Quantitative Information about Recurring Fair Value Measurement of Assets and Liabilities Classified as Level 3 (Detail) $ in Millions		3 Months Ended		12 Months Ended
		Mar. 31, 2020USD ($)		Dec. 31, 2019USD ($)		Mar. 31, 2019USD ($)		Dec. 31, 2018USD ($)
Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value		$ 679		$ 703		$ 870		$ 2,088
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value		(1,024)		(1,128)		(1,402)		(1,337)
Deposits [Member] | Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value	[1]	(653)	[2],[3]	(774)	[2],[3]	(949)		(925)
Long-term debt [Member] | Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value	[1]	(371)	[2],[3]	(354)	[2],[3]	(453)		(412)
Interest rate contracts [Member] | Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	[4]	41		10		7		2
Foreign exchange contracts [Member] | Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	[4]	(3)	[3]	(1)	[3]	(1)		(1)
Equity contracts [Member] | Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	[4]	4	[3]	72	[3]	24		(52)
Credit contracts [Member] | Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	[4]	98		59		53		52
Other Contracts [Member] | Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	[4]	(58)		(75)		(37)		(35)
Trading assets, excluding derivatives [Member] | Collateralized debt obligations [Member] | Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	[5]					90		100
Trading assets, excluding derivatives [Member] | Residential mortgage asset-backed securities [Member] | Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value		16	[5]	17	[5]	16		16
Trading assets, excluding derivatives [Member] | Student loan asset-backed securities [Member] | Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value						95		92
Trading assets, excluding derivatives [Member] | Corporate and other domestic debt securities [Member] | Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value		465		510		510	[5]	1,803	[5]
Available-for-sale securities [Member] | Other asset-backed securities available-for-sale [Member] | Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	[6]	$ 116		$ 111		109		107
Other assets [Member] | Level 3 [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	[7]					$ 4		$ 4
Measurement Input, Prepayment Rates [Member] | Residential mortgage asset-backed securities [Member] | Recurring [Member] | Valuation Technique, Broker Quotes or Consensus Pricing [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Debt Securities, Trading, Measurement Input		0.03		0.01
Measurement Input, Default Rates [Member] | Residential mortgage asset-backed securities [Member] | Recurring [Member] | Valuation Technique, Broker Quotes or Consensus Pricing [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Debt Securities, Trading, Measurement Input		0.08		0.08
Measurement Input, Loss Severity Rates [Member] | Residential mortgage asset-backed securities [Member] | Recurring [Member] | Valuation Technique, Broker Quotes or Consensus Pricing [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Debt Securities, Trading, Measurement Input		0.70		0.70
Measurement Input, Discount Margin [Member] | Residential mortgage asset-backed securities [Member] | Recurring [Member] | Valuation Technique, Broker Quotes or Consensus Pricing [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Debt Securities, Trading, Measurement Input		0.0879		0.0600
Measurement Input, Spread Volatility on Collateral Assets [Member] | Corporate and other domestic debt securities [Member] | Recurring [Member] | Valuation Technique, Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Debt Securities, Trading, Measurement Input		0.04		0.04
Measurement Input, Correlation between Insurance Claim Shortfall and Collateral Value [Member] | Corporate and other domestic debt securities [Member] | Recurring [Member] | Valuation Technique, Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Debt Securities, Trading, Measurement Input		0.80		0.80
Measurement Input, Probability to Fund for Rate Lock Commitments [Member] | Interest rate contracts [Member] | Recurring [Member] | Minimum [Member] | Valuation Technique, Market Comparable Adjusted for Probability to Fund [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input		0.41		0.42
Measurement Input, Probability to Fund for Rate Lock Commitments [Member] | Interest rate contracts [Member] | Recurring [Member] | Maximum [Member] | Valuation Technique, Market Comparable Adjusted for Probability to Fund [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input		1		1
Measurement Input, Probability to Fund for Rate Lock Commitments [Member] | Interest rate contracts [Member] | Recurring [Member] | Weighted Average [Member] | Valuation Technique, Market Comparable Adjusted for Probability to Fund [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input		0.72		0.80
Measurement Input, Interest Rate Transaction Execution [Member] | Interest rate contracts [Member] | Recurring [Member] | Valuation Technique, Market Comparable Adjusted for Probability to Fund [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input		0.90		0.90
Measurement Input, Implied Volatility of Currency Pairs [Member] | Deposits [Member] | Recurring [Member] | Minimum [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic Deposits, Measurement Input	[2],[3]	0.10		0.06
Measurement Input, Implied Volatility of Currency Pairs [Member] | Deposits [Member] | Recurring [Member] | Maximum [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic Deposits, Measurement Input	[2],[3]	0.17		0.11
Measurement Input, Implied Volatility of Currency Pairs [Member] | Deposits [Member] | Recurring [Member] | Weighted Average [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic Deposits, Measurement Input	[2],[3]	0.13		0.08
Measurement Input, Implied Volatility of Currency Pairs [Member] | Long-term debt [Member] | Recurring [Member] | Minimum [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term Debt, Measurement Input	[2],[3]	0.10		0.06
Measurement Input, Implied Volatility of Currency Pairs [Member] | Long-term debt [Member] | Recurring [Member] | Maximum [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term Debt, Measurement Input	[2],[3]	0.17		0.11
Measurement Input, Implied Volatility of Currency Pairs [Member] | Long-term debt [Member] | Recurring [Member] | Weighted Average [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term Debt, Measurement Input	[2],[3]	0.13		0.08
Measurement Input, Implied Volatility of Currency Pairs [Member] | Foreign exchange contracts [Member] | Recurring [Member] | Minimum [Member] | Valuation Technique, Option Pricing Model [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	[3]	0.10		0.06
Measurement Input, Implied Volatility of Currency Pairs [Member] | Foreign exchange contracts [Member] | Recurring [Member] | Maximum [Member] | Valuation Technique, Option Pricing Model [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	[3]	0.17		0.11
Measurement Input, Implied Volatility of Currency Pairs [Member] | Foreign exchange contracts [Member] | Recurring [Member] | Weighted Average [Member] | Valuation Technique, Option Pricing Model [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	[3]	0.13		0.08
Measurement Input, Equity / Equity Index Volatility [Member] | Deposits [Member] | Recurring [Member] | Minimum [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic Deposits, Measurement Input	[2],[3]	0.07		0.07
Measurement Input, Equity / Equity Index Volatility [Member] | Deposits [Member] | Recurring [Member] | Maximum [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic Deposits, Measurement Input	[2],[3]	0.60		0.28
Measurement Input, Equity / Equity Index Volatility [Member] | Deposits [Member] | Recurring [Member] | Weighted Average [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic Deposits, Measurement Input	[2],[3]	0.29		0.13
Measurement Input, Equity / Equity Index Volatility [Member] | Long-term debt [Member] | Recurring [Member] | Minimum [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term Debt, Measurement Input	[2],[3]	0.08		0.07
Measurement Input, Equity / Equity Index Volatility [Member] | Long-term debt [Member] | Recurring [Member] | Maximum [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term Debt, Measurement Input	[2],[3]	0.71		0.29
Measurement Input, Equity / Equity Index Volatility [Member] | Long-term debt [Member] | Recurring [Member] | Weighted Average [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term Debt, Measurement Input	[2],[3]	0.33		0.16
Measurement Input, Equity / Equity Index Volatility [Member] | Equity contracts [Member] | Recurring [Member] | Minimum [Member] | Valuation Technique, Option Pricing Model [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	[3]	0.06		0.07
Measurement Input, Equity / Equity Index Volatility [Member] | Equity contracts [Member] | Recurring [Member] | Maximum [Member] | Valuation Technique, Option Pricing Model [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	[3]	0.81		0.36
Measurement Input, Equity / Equity Index Volatility [Member] | Equity contracts [Member] | Recurring [Member] | Weighted Average [Member] | Valuation Technique, Option Pricing Model [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	[3]	0.35		0.22
Measurement Input, Equity/Equity and Equity/Index Correlation [Member] | Deposits [Member] | Recurring [Member] | Minimum [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic Deposits, Measurement Input		0.43		0.43
Measurement Input, Equity/Equity and Equity/Index Correlation [Member] | Deposits [Member] | Recurring [Member] | Maximum [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic Deposits, Measurement Input		0.60		0.49
Measurement Input, Equity/Equity and Equity/Index Correlation [Member] | Deposits [Member] | Recurring [Member] | Weighted Average [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Domestic Deposits, Measurement Input		0.46		0.46
Measurement Input, Equity/Equity and Equity/Index Correlation [Member] | Long-term debt [Member] | Recurring [Member] | Minimum [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term Debt, Measurement Input	[2],[3]	0.55		0.54
Measurement Input, Equity/Equity and Equity/Index Correlation [Member] | Long-term debt [Member] | Recurring [Member] | Maximum [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term Debt, Measurement Input	[2],[3]	0.78		0.79
Measurement Input, Equity/Equity and Equity/Index Correlation [Member] | Long-term debt [Member] | Recurring [Member] | Weighted Average [Member] | Valuation Technique, Option Adjusted Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Long-term Debt, Measurement Input	[2],[3]	0.66		0.64
Measurement Input, Equity/Equity and Equity/Index Correlation [Member] | Equity contracts [Member] | Recurring [Member] | Minimum [Member] | Valuation Technique, Option Pricing Model [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	[3]	0.43		0.43
Measurement Input, Equity/Equity and Equity/Index Correlation [Member] | Equity contracts [Member] | Recurring [Member] | Maximum [Member] | Valuation Technique, Option Pricing Model [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	[3]	0.78		0.79
Measurement Input, Equity/Equity and Equity/Index Correlation [Member] | Equity contracts [Member] | Recurring [Member] | Weighted Average [Member] | Valuation Technique, Option Pricing Model [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	[3]	0.50		0.49
Measurement Input, Equity Dividend Yields and Forward Price [Member] | Equity contracts [Member] | Recurring [Member] | Minimum [Member] | Valuation Technique, Option Pricing Model [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	[3]	(0.07)		0
Measurement Input, Equity Dividend Yields and Forward Price [Member] | Equity contracts [Member] | Recurring [Member] | Maximum [Member] | Valuation Technique, Option Pricing Model [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	[3]	0.03		0.04
Measurement Input, Equity Dividend Yields and Forward Price [Member] | Equity contracts [Member] | Recurring [Member] | Weighted Average [Member] | Valuation Technique, Option Pricing Model [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	[3]	0		0.02
Measurement Input, Credit Default Swap Spreads [Member] | Credit contracts [Member] | Recurring [Member] | Valuation Technique, Option Pricing Model [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input		0.0200		0.0041
Measurement Input, Conversion Rate [Member] | Other Contracts [Member] | Recurring [Member] | Valuation Technique, Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input		1.6		1.6
Measurement Input, Expected Duration [Member] | Other Contracts [Member] | Recurring [Member] | Valuation Technique, Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Derivative Contract, Duration, Measurement Input		3 years		3 years
Measurement Input, Market Assumptions Related to Yields for Comparable Instruments [Member] | Other asset-backed securities available-for-sale [Member] | Recurring [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		0.04		0
Measurement Input, Market Assumptions Related to Yields for Comparable Instruments [Member] | Other asset-backed securities available-for-sale [Member] | Recurring [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		0.05		0.03
Measurement Input, Market Assumptions Related to Yields for Comparable Instruments [Member] | Other asset-backed securities available-for-sale [Member] | Recurring [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flows [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		0.05		0.02
[1]	Excluding unrealized gains (losses) on fair value option liabilities attributable to our own credit spread, which are recorded in other comprehensive income, gains (losses) on fair value option liabilities are included in loss on instruments designated at fair value and related derivatives in the consolidated statement of income (loss).
[2]	Structured deposits and structured notes contain embedded derivative features whose fair value measurements contain significant Level 3 inputs. See equity and foreign exchange derivatives below for a discussion of the uncertainty of Level 3 inputs related to structured deposits and structured notes.
[3]	We are the client-facing entity and we enter into identical but opposite derivatives to transfer the resultant risks to our affiliates. With the exception of counterparty credit risks, we are market neutral. The corresponding intra-group derivatives are presented as equity derivatives and foreign exchange derivatives in the table.
[4]	Level 3 net derivatives included derivative assets of $628 million and derivative liabilities of $546 million at March 31, 2020 and derivative assets of $288 million and derivative liabilities of $242 million at March 31, 2019. Gains (losses) on derivatives, net are predominantly included in trading revenue and loss on instruments designated at fair value and related derivatives in the consolidated statement of income (loss).
[5]	Gains (losses) on trading assets, excluding derivatives are included in trading revenue in the consolidated statement of income (loss).
[6]	Realized gains (losses) on securities available-for-sale are included in other securities gains, net in the consolidated statement of income (loss). Changes in the allowance for credit losses on securities available-for-sale are included in the provision for credit losses in the consolidated statement of income (loss). Unrealized gains (losses) on securities available-for-sale are included in other comprehensive income.
[7]	Represented contingent consideration receivable associated with the sale of a portion of our PB business, which concluded in 2019. Gains (losses) associated with this transaction were included in other income (loss) in the consolidated statement of income (loss).

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020		Mar. 31, 2019	Dec. 31, 2019		Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Unfunded commitments, equity securities measured at net asset value		$ 37			$ 41
Revaluation period		90 days
Deferred fees		$ 3			2
Derivative financial assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of level 3 assets		628		$ 288
Derivative financial liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of level 3 liabilities	[1]	546		242
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of level 3 assets		679		870	703		$ 2,088
Fair value of level 3 liabilities		1,024		1,402	1,128		1,337
Fair Value Assets, Transfers Into Level 3		0		0
Fair Value Assets, Transfers Out of Level 3		0		1
Fair Value Liability, Transfers Into Level 3		0		0
Fair Value Liability, Transfers Out of Level 3		37		69
Level 3 [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivatives, net, Transfers out of Level 3	[2]	0		1
Unfunded Loan Commitment [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Deferred fees		157			162
Deposits [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of level 3 liabilities	[1]	653	[3],[4]	949	774	[3],[4]	925
Fair Value Liability, Transfers Into Level 3	[1]	0		0
Fair Value Liability, Transfers Out of Level 3	[1]	33		61
Long-term debt [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of level 3 liabilities	[1]	371	[3],[4]	453	354	[3],[4]	412
Fair Value Liability, Transfers Into Level 3	[1]	0		0
Fair Value Liability, Transfers Out of Level 3	[1]	4		8
Collateralized debt obligations [Member] | Level 3 [Member] | Trading assets, excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of level 3 assets	[5]			90			100
Fair Value Assets, Transfers Into Level 3	[5]			0
Fair Value Assets, Transfers Out of Level 3	[5]			0
Residential mortgage asset-backed securities [Member] | Level 3 [Member] | Trading assets, excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of level 3 assets		16	[5]	16	$ 17	[5]	16
Fair Value Assets, Transfers Into Level 3		0		0
Fair Value Assets, Transfers Out of Level 3		$ 0	[5]	0
Student loan asset-backed securities [Member] | Level 3 [Member] | Trading assets, excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of level 3 assets				95			$ 92
Fair Value Assets, Transfers Into Level 3				0
Fair Value Assets, Transfers Out of Level 3				$ 0
[1]	Excluding unrealized gains (losses) on fair value option liabilities attributable to our own credit spread, which are recorded in other comprehensive income, gains (losses) on fair value option liabilities are included in loss on instruments designated at fair value and related derivatives in the consolidated statement of income (loss).
[2]	Level 3 net derivatives included derivative assets of $628 million and derivative liabilities of $546 million at March 31, 2020 and derivative assets of $288 million and derivative liabilities of $242 million at March 31, 2019. Gains (losses) on derivatives, net are predominantly included in trading revenue and loss on instruments designated at fair value and related derivatives in the consolidated statement of income (loss).
[3]	Structured deposits and structured notes contain embedded derivative features whose fair value measurements contain significant Level 3 inputs. See equity and foreign exchange derivatives below for a discussion of the uncertainty of Level 3 inputs related to structured deposits and structured notes.
[4]	We are the client-facing entity and we enter into identical but opposite derivatives to transfer the resultant risks to our affiliates. With the exception of counterparty credit risks, we are market neutral. The corresponding intra-group derivatives are presented as equity derivatives and foreign exchange derivatives in the table.
[5]	Gains (losses) on trading assets, excluding derivatives are included in trading revenue in the consolidated statement of income (loss).

Fair Value Measurements - Ass_2

Fair Value Measurements - Assets and Liabilities Recorded as Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Sep. 30, 2019
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Total Gains (Losses)		$ (902)	$ (4)
Residential Mortgage [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Total Gains (Losses)	[1]	0	0
Consumer loans [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Total Gains (Losses)	[2]	3	(2)
Impaired commercial loans [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Total Gains (Losses)	[3]	(53)	(1)
Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Total Gains (Losses)	[4]	0	(1)
Goodwill [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Total Gains (Losses)	[5]	(784)	0
Leases [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Total Gains (Losses)	[6]	(68)	$ 0
Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		423		$ 456
Fair Value, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		0		0
Fair Value, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		340		32
Fair Value, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		83		424
Fair Value, Nonrecurring [Member] | Residential Mortgage [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[1]	7		12
Fair Value, Nonrecurring [Member] | Residential Mortgage [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[1]	0		0
Fair Value, Nonrecurring [Member] | Residential Mortgage [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[1]	7		12
Fair Value, Nonrecurring [Member] | Residential Mortgage [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[1]	0		0
Fair Value, Nonrecurring [Member] | Consumer loans [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[2]	330		14
Fair Value, Nonrecurring [Member] | Consumer loans [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[2]	0		0
Fair Value, Nonrecurring [Member] | Consumer loans [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[2]	330		14
Fair Value, Nonrecurring [Member] | Consumer loans [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[2]	0		0
Fair Value, Nonrecurring [Member] | Impaired commercial loans [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[3]	58		50
Fair Value, Nonrecurring [Member] | Impaired commercial loans [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[3]	0		0
Fair Value, Nonrecurring [Member] | Impaired commercial loans [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[3]	0		0
Fair Value, Nonrecurring [Member] | Impaired commercial loans [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[3]	58		50
Fair Value, Nonrecurring [Member] | Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[4]	3		6
Fair Value, Nonrecurring [Member] | Real Estate Owned [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[4]	0		0
Fair Value, Nonrecurring [Member] | Real Estate Owned [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[4]	3		6
Fair Value, Nonrecurring [Member] | Real Estate Owned [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[4]	0		0
Fair Value, Nonrecurring [Member] | Goodwill [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[5]	0		372
Fair Value, Nonrecurring [Member] | Goodwill [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[5]	0		0
Fair Value, Nonrecurring [Member] | Goodwill [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[5]	0		0
Fair Value, Nonrecurring [Member] | Goodwill [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[5]	0		372
Fair Value, Nonrecurring [Member] | Leases [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[6]	25		2
Fair Value, Nonrecurring [Member] | Leases [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[6]	0		0
Fair Value, Nonrecurring [Member] | Leases [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[6]	0		0
Fair Value, Nonrecurring [Member] | Leases [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[6]	25		$ 2
RBWM [Member] | Fair Value, Nonrecurring [Member] | Goodwill [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[5]	0			$ 372
PB [Member] | Fair Value, Nonrecurring [Member] | Goodwill [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		$ 0
[1]	At March 31, 2020 and December 31, 2019, the fair value of the loans held for sale was below cost.
[2]	Represents residential mortgage loans held for investment whose carrying amount was adjusted during the period based on the fair value of the underlying collateral. The increase at March 31, 2020 reflects the impact of adopting new accounting guidance which requires expected recoveries related to subsequent increases in the fair value of collateral for collateral-dependent loans to be recognized in the allowance for credit losses beginning January 1, 2020. See Note 21, "New Accounting Pronouncements," for additional discussion.
[3]	Certain commercial loans are individually assessed for impairment. We measure the credit impairment of a collateral-dependent loan based on the fair value of the collateral asset. The collateral often involves real estate properties that are illiquid due to market conditions. As a result, these loans are classified as a Level 3 fair value measurement within the fair value hierarchy.
[4]	Real estate owned is required to be reported on the balance sheet net of transactions costs. The real estate owned amounts in the table above reflect the fair value unadjusted for transaction costs.
[5]	During the first quarter of 2020, the goodwill allocated to our RBWM and PB businesses were both written down to $0 million. During the third quarter of 2019, the goodwill allocated to our RBWM business was written down to $372 million. See Note 8, "Goodwill," in this Form 10-Q and Note 9, "Goodwill" in our 2019 Form 10-K for further discussion of the results of our goodwill impairment testing, including the events and circumstances leading to the impairments.
[6]	Beginning in the fourth quarter of 2019 and into the first quarter of 2020, we determined that we would exit certain branches and, as a result, the lease ROU assets and leasehold improvement assets associated with these branches were written down based on their estimated remaining useful lives. See Note 2, "Strategic Initiatives," in this Form 10-Q and Note 10, "Leases" in our 2019 Form 10-K for further discussion.

Fair Value Measurements - Qua_2

Fair Value Measurements - Quantitative Information about Nonrecurring Fair Value Measurement of Assets and Liabilities Classified as Level 3 (Detail) - Fair Value, Nonrecurring [Member] $ in Millions		Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		$ 423	$ 456
Residential mortgages [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[1]	7	12
Impaired commercial loans [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[2]	58	50
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		83	424
Level 3 [Member] | Residential mortgages [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[1]	0	0
Level 3 [Member] | Impaired commercial loans [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[2]	$ 58	$ 50
Measurement Input, Loss Severity Rates [Member] | Level 3 [Member] | Impaired commercial loans [Member] | Minimum [Member] | Third Party Appraisal [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Loans, Measurement Input		0.09	0.09
Measurement Input, Loss Severity Rates [Member] | Level 3 [Member] | Impaired commercial loans [Member] | Maximum [Member] | Third Party Appraisal [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Loans, Measurement Input		0.93	1
Measurement Input, Loss Severity Rates [Member] | Level 3 [Member] | Impaired commercial loans [Member] | Weighted Average [Member] | Third Party Appraisal [Member]
Fair Value, Assets and Liabilities Measured on a Nonrecurring Basis [Line Items]
Loans, Measurement Input	[3]	0.53	0.45
[1]	At March 31, 2020 and December 31, 2019, the fair value of the loans held for sale was below cost.
[2]	Certain commercial loans are individually assessed for impairment. We measure the credit impairment of a collateral-dependent loan based on the fair value of the collateral asset. The collateral often involves real estate properties that are illiquid due to market conditions. As a result, these loans are classified as a Level 3 fair value measurement within the fair value hierarchy.
[3]	Weighted average is calculated based on the carrying value of the loans.

Fair Value Measurements - Add_2

Fair Value Measurements - Additional Information Relating To Asset-Backed Securities and Collateralized Debt Obligations (Detail) $ in Millions	Mar. 31, 2020USD ($)
AAA - A Rating [Member] | Level 3 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	$ 0	[1]
AAA - A Rating [Member] | Level 2 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	112	[1]
Collateralized debt obligations [Member] | AAA - A Rating [Member] | Level 3 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	0	[1]
Collateralized debt obligations [Member] | AAA - A Rating [Member] | Level 2 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	39	[1]
Collateralized debt obligations [Member] | BBB -B Rating [Member] | Level 3 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	0	[1]
Collateralized debt obligations [Member] | BBB -B Rating [Member] | Level 2 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	28	[1]
Student loans [Member] | AAA - A Rating [Member] | Level 3 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	0	[1]
Student loans [Member] | AAA - A Rating [Member] | Level 2 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	73	[1]
Other [Member] | BBB -B Rating [Member] | Level 3 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	116	[1]
Other [Member] | BBB -B Rating [Member] | Level 2 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	0	[1]
Trading assets, excluding derivatives [Member] | Level 3 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	16	[1]
Trading assets, excluding derivatives [Member] | Level 2 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	140	[1]
Available-for-sale securities [Member] | Level 3 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	116
Available-for-sale securities [Member] | Level 2 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	28
Estimate of fair value [Member] | AAA - A Rating [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	112	[1]
Estimate of fair value [Member] | Collateralized debt obligations [Member] | AAA - A Rating [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	39	[1]
Estimate of fair value [Member] | Collateralized debt obligations [Member] | BBB -B Rating [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	28	[1]
Estimate of fair value [Member] | Student loans [Member] | AAA - A Rating [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	73	[1]
Estimate of fair value [Member] | Other [Member] | BBB -B Rating [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	116	[1]
Estimate of fair value [Member] | Trading assets, excluding derivatives [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	156	[1]
Estimate of fair value [Member] | Available-for-sale securities [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	144
Alt [Member] | Home equity [Member] | AAA - A Rating [Member] | Level 3 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	0	[1]
Alt [Member] | Home equity [Member] | AAA - A Rating [Member] | Level 2 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	28	[1]
Alt [Member] | Estimate of fair value [Member] | Home equity [Member] | AAA - A Rating [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	28	[1]
Subprime [Member] | Residential mortgage - Subprime [Member] | CCC - Unrated [Member] | Level 3 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	16	[1]
Subprime [Member] | Residential mortgage - Subprime [Member] | CCC - Unrated [Member] | Level 2 [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	0	[1]
Subprime [Member] | Estimate of fair value [Member] | Residential mortgage - Subprime [Member] | CCC - Unrated [Member]
Fair Value Of Other Financial Instrument [Line Items]
Trading asset-backed securities and related collateral	$ 16	[1]
[1]	We utilize S&P as the primary source of credit ratings in the tables above. If S&P ratings are not available, ratings by Moody's and Fitch are used in that order. Ratings for CDOs represent the ratings associated with the underlying collateral.

Fair Value Measurements - Carry

Fair Value Measurements - Carrying Value and Estimated Fair Value of Financial Instruments (Detail) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Federal funds sold and securities purchased under agreements to resell	$ 4,643	$ 17,838
Securities held-to-maturity	12,981	13,293
Loans, net of allowance for credit losses	80,797	67,916	$ 70,451
Loans held for sale	285	289
Deposits	136,723	119,693	$ 113,639
Long-term debt	24,777	26,697
Commercial Loans [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans held for sale	234	212
Consumer Loans [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans held for sale	51	77
Consumer Loans [Member] | Residential Mortgage [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans held for sale	51	77
Level 1 [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Short-term financial assets, net of allowance for credit losses	983
Short-term financial assets		1,744
Federal funds sold and securities purchased under agreements to resell	0	0
Securities held-to-maturity, net of allowance for credit losses	0
Securities held-to-maturity		0
Short-term financial liabilities	0	0
Long-term debt	0	0
Level 1 [Member] | Commercial Loans [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans, net of allowance for credit losses	0	0
Loans held for sale	0	0
Level 1 [Member] | Consumer Loans [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans, net of allowance for credit losses	0	0
Level 1 [Member] | Consumer Loans [Member] | Residential Mortgage [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans held for sale	0	0
Level 1 [Member] | Deposits Without Fixed Maturities [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Deposits	0	0
Level 1 [Member] | Deposits With Fixed Maturities [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Deposits	0	0
Level 2 [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Short-term financial assets, net of allowance for credit losses	26,496
Short-term financial assets		2,038
Federal funds sold and securities purchased under agreements to resell	4,643	17,838
Securities held-to-maturity, net of allowance for credit losses	13,446
Securities held-to-maturity		13,431
Short-term financial liabilities	17,579	3,286
Long-term debt	16,485	16,696
Level 2 [Member] | Commercial Loans [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans, net of allowance for credit losses	0	0
Loans held for sale	28	34
Level 2 [Member] | Consumer Loans [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans, net of allowance for credit losses	0	0
Level 2 [Member] | Consumer Loans [Member] | Residential Mortgage [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans held for sale	51	77
Level 2 [Member] | Deposits Without Fixed Maturities [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Deposits	115,371	96,161
Level 2 [Member] | Deposits With Fixed Maturities [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Deposits	14,917	16,264
Level 3 [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Short-term financial assets, net of allowance for credit losses	11
Short-term financial assets		18
Federal funds sold and securities purchased under agreements to resell	0	0
Securities held-to-maturity, net of allowance for credit losses	0
Securities held-to-maturity		0
Short-term financial liabilities	13	18
Long-term debt	0	0
Level 3 [Member] | Commercial Loans [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans, net of allowance for credit losses	60,987	49,252
Loans held for sale	0	0
Level 3 [Member] | Consumer Loans [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans, net of allowance for credit losses	19,953	19,889
Level 3 [Member] | Consumer Loans [Member] | Residential Mortgage [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans held for sale	0	1
Level 3 [Member] | Deposits Without Fixed Maturities [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Deposits	0	0
Level 3 [Member] | Deposits With Fixed Maturities [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Deposits	0	0
Carrying Value [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Short-term financial assets, net of allowance for credit losses	27,490
Short-term financial assets		3,800
Federal funds sold and securities purchased under agreements to resell	4,643	17,838
Securities held-to-maturity, net of allowance for credit losses	12,981
Securities held-to-maturity		13,293
Short-term financial liabilities	17,592	3,304
Long-term debt	16,402	16,350
Carrying Value [Member] | Commercial Loans [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans, net of allowance for credit losses	60,519	47,704
Loans held for sale	28	34
Carrying Value [Member] | Consumer Loans [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans, net of allowance for credit losses	20,278	20,212
Carrying Value [Member] | Consumer Loans [Member] | Residential Mortgage [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans held for sale	51	77
Carrying Value [Member] | Deposits Without Fixed Maturities [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Deposits	115,371	96,161
Carrying Value [Member] | Deposits With Fixed Maturities [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Deposits	14,981	16,323
Estimate of fair value [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Short-term financial assets, net of allowance for credit losses	27,490
Short-term financial assets		3,800
Federal funds sold and securities purchased under agreements to resell	4,643	17,838
Securities held-to-maturity, net of allowance for credit losses	13,446
Securities held-to-maturity		13,431
Short-term financial liabilities	17,592	3,304
Long-term debt	16,485	16,696
Estimate of fair value [Member] | Commercial Loans [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans, net of allowance for credit losses	60,987	49,252
Loans held for sale	28	34
Estimate of fair value [Member] | Consumer Loans [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans, net of allowance for credit losses	19,953	19,889
Estimate of fair value [Member] | Consumer Loans [Member] | Residential Mortgage [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Loans held for sale	51	78
Estimate of fair value [Member] | Deposits Without Fixed Maturities [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Deposits	115,371	96,161
Estimate of fair value [Member] | Deposits With Fixed Maturities [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Deposits	$ 14,917	$ 16,264

Litigation and Regulatory Mat_2

Litigation and Regulatory Matters - Additional Information (Details)	Mar. 31, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
Estimate of reasonably possible loss	$ 225,000,000

New Accounting Pronouncements (

New Accounting Pronouncements (Details) - USD ($) $ in Millions	Jan. 01, 2020	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative decrease in allowance for credit losses on loans	$ (467)	$ (931)	$ (637)	$ (583)	$ (541)
Liability for off-balance sheet credit exposures	158	$ 371	$ 158	$ 89	$ 96
Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative decrease in allowance for credit losses on loans	170
Liability for off-balance sheet credit exposures	54
Increase in retained earnings, after tax	82
Commercial Loans [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative decrease in allowance for credit losses on loans	126
Consumer Loans [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative decrease in allowance for credit losses on loans	44
Student Loan [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase in retained earnings, after tax	$ 2