Discover Financial Services (DFS) 10-Q 23 Dec 24 2024 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Dec. 13, 2024
Cover [Abstract]
Document type	10-Q
Document quarterly report	true
Document period end date	Sep. 30, 2024
Document transition report	false
Entity file number	001-33378
Entity registrant name	DISCOVER FINANCIAL SERVICES
Entity incorporation, state	DE
Entity tax identification number	36-2517428
Entity address, address line one	2500 Lake Cook Road
Entity address, city or town	Riverwoods
Entity address, state or province	IL
Entity address, postal zip code	60015
Entity phone number, city area code	224
Entity phone number, local phone number	405-0900
Title of 12(b) security	Common Stock, par value $0.01 per share
Trading symbol	DFS
Security exchange name	NYSE
Entity current reporting status	Yes
Entity interactive data current	Yes
Entity filer category	Large Accelerated Filer
Smaller reporting company	false
Emerging growth company	false
Entity shell company	false
Entity common stock, shares outstanding		251,226,920
Entity central index key	0001393612
Current fiscal year end date	--12-31
Document fiscal year focus	2024
Document fiscal period focus	Q3
Amendment flag	false

Condensed Consolidated Statemen

Condensed Consolidated Statements of Financial Condition - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Assets
Cash and cash equivalents	$ 10,787	$ 11,685
Restricted cash	36	43
Other short-term investments	735	0
Investment securities (includes available-for-sale securities of $14,590 and $13,402 reported at fair value with associated amortized cost of $14,470 and $13,451 at September 30, 2024 and December 31, 2023, respectively)	14,865	13,655
Loan receivables
Financing Receivable, Held-for-Sale	8,484	0
Loan Portfolio, excluding held for sale	118,509	128,409
Loan portfolio	126,993	128,409
Allowance for credit losses	(8,512)	(9,283)
Net loan receivables	118,481	119,126
Premises and equipment, net	1,085	1,091
Goodwill	255	255
Other assets	5,371	5,858
Total assets	151,615	151,713
Deposits
Interest-bearing deposit accounts	108,356	107,493
Non-interest bearing deposit accounts	1,496	1,438
Total deposits	109,852	108,931
Short-term borrowings	750	750
Long-term borrowings	17,427	20,581
Accrued expenses and other liabilities	6,477	7,216
Total liabilities	134,506	137,478
Commitments, contingencies and guarantees (Notes 9, 12 and 13)
Stockholders' Equity
Common stock, par value $0.01 per share; 2,000,000,000 shares authorized; 572,469,165 and 570,837,720 shares issued at September 30, 2024 and December 31, 2023, respectively	6	6
Preferred stock, par value $0.01 per share; 200,000,000 shares authorized; 10,700 shares issued and outstanding at September 30, 2024 and December 31, 2023, respectively	1,056	1,056
Additional paid-in capital	4,633	4,553
Retained earnings	32,469	29,855
Accumulated other comprehensive income (loss)	17	(225)
Treasury stock, at cost; 321,255,534 and 320,734,860 shares at September 30, 2024 and December 31, 2023, respectively	(21,072)	(21,010)
Total stockholders' equity	17,109	14,235
Total liabilities and stockholders' equity	151,615	151,713
Variable Interest Entity, Primary Beneficiary [Member]
Assets
Restricted cash	36	43
Loan receivables
Financing Receivable, Held-for-Sale	132	0
Loan Portfolio, excluding held for sale	28,643
Loan portfolio		30,590
Allowance for credit losses	(1,334)	(1,347)
Other assets	4	3
Deposits
Short- and long-term borrowings	9,307	11,743
Accrued expenses and other liabilities	$ 15	$ 19

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Millions		Sep. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Available-for-sale investment securities, fair value	[1]	$ 14,590	$ 13,402
Available-for-sale investment securities, amortized cost	[1]	$ 14,470	$ 13,451
Common Stock, Par or Stated Value Per Share		$ 0.01	$ 0.01
Common Stock, Shares Authorized		2,000,000,000	2,000,000,000
Common Stock, Shares, Issued		572,469,165	570,837,720
Preferred stock, par or stated value per Share		$ 0.01	$ 0.01
Preferred Stock, Shares Authorized		200,000,000	200,000,000
Preferred Stock, Shares Issued		10,700	10,700
Preferred Stock, Shares Outstanding		10,700	10,700
Treasury Stock, Common, Shares		321,255,534	320,734,860
[1] Available-for-sale investment securities are reported at fair value.

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Income - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Interest income
Credit card loans		$ 4,092	$ 3,726	$ 11,989	$ 10,513
Other loans, including loans held-for-sale		742	653	2,183	1,823
Investment securities		130	120	379	327
Other interest income		148	111	480	314
Interest income		5,112	4,610	15,031	12,977
Interest expense
Deposits		1,213	1,061	3,622	2,722
Short-term borrowings		8	2	14	2
Long-term borrowings		236	225	729	622
Interest Expense, Operating, Total		1,457	1,288	4,365	3,346
Net interest income		3,655	3,322	10,666	9,631
Provision for credit losses		1,473	1,702	3,709	4,109
Net interest income after provision for credit losses		2,182	1,620	6,957	5,522
Other income
Discount and interchange revenue, net	[1]	363	360	1,121	1,027
Protection products revenue		42	42	126	129
Loan fee income		214	194	619	546
Transaction processing revenue		84	82	262	221
Other non-interest income subject to ASC 606		95	27	357	60
Total other income		798	705	2,485	1,983
Other expense
Employee compensation and benefits		703	575	2,032	1,788
Marketing and business development		263	283	771	792
Information processing and communications		197	149	527	438
Professional fees		323	281	911	729
Premises and equipment		25	22	68	64
Other expense		277	254	761	540
Total other expense		1,788	1,564	5,070	4,351
Income before income taxes		1,192	761	4,372	3,154
Income tax expense		322	175	1,128	724
Net income		870	586	3,244	2,430
Net income allocated to common stockholders		$ 834	$ 550	$ 3,162	$ 2,351
Basic earnings per common share		$ 3.32	$ 2.21	$ 12.61	$ 9.23
Diluted earnings per common share		$ 3.32	$ 2.21	$ 12.61	$ 9.22
[1] Net of rewards, including Cashback Bonus rewards, of $779 million and $787 million for the three months ended September 30, 2024 and 2023, respectively, and $2.2 billion and $2.3 billion for the nine months ended September 30, 2024 and 2023 , respectively.

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 870	$ 586	$ 3,244	$ 2,430
Other comprehensive income (loss), net of tax
Unrealized gains (losses) on available-for-sale investment securities, net of tax	239	(83)	128	(142)
Unrealized gains (losses) on cash flow hedges, net of tax	176	(20)	114	(92)
Other comprehensive income (loss)	415	(103)	242	(234)
Comprehensive income	$ 1,285	$ 483	$ 3,486	$ 2,196

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive (Loss) Income [Member]	Treasury Stock, Common	Series C Preferred Stock [Member]	Series C Preferred Stock [Member] Retained Earnings [Member]	Series D Preferred Stock	Series D Preferred Stock Retained Earnings [Member]
Preferred stock, shares outstanding, balance at beginning of period (in shares) at Dec. 31, 2022			11,000
Common stock, shares outstanding, balance at beginning of period (in shares) at Dec. 31, 2022				569,689,000
Stockholders' equity, balance at beginning of period at Dec. 31, 2022	$ 13,895		$ 1,056	$ 6	$ 4,468	$ 27,758		$ (339)	$ (19,054)
Stockholders' equity, balance at beginning of period (Accounting Standards Update 2022-02) at Dec. 31, 2022		$ 52					$ 52
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,430					2,430
Other comprehensive income	(234)							(234)
Purchases of treasury stock	(1,955)								(1,955)
Common stock issued under employee benefit plans (in shares)				90,000
Common stock issued under employee benefit plans	9			$ 0	9
Common stock issued and stock-based compensation expense				1,002,000
Common stock issued and stock-based compensation expense	43			$ 0	43
Dividends — common stock	(513)					(513)
Dividends — preferred stock										$ (31)	$ (31)	$ (31)	$ (31)
Preferred stock, shares outstanding, balance at end of period (in shares) at Sep. 30, 2023			11,000
Common stock, shares outstanding, balance at end of period (in shares) at Sep. 30, 2023				570,781,000
Stockholders' equity, balance at end of period at Sep. 30, 2023	13,665		$ 1,056	$ 6	4,520	29,665		(573)	(21,009)
Preferred stock, shares outstanding, balance at beginning of period (in shares) at Jun. 30, 2023			11,000
Common stock, shares outstanding, balance at beginning of period (in shares) at Jun. 30, 2023				570,628,000
Stockholders' equity, balance at beginning of period at Jun. 30, 2023	13,382		$ 1,056	$ 6	4,508	29,287		(470)	(21,005)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	586					586
Other comprehensive income	(103)							(103)
Purchases of treasury stock	(4)								(4)
Common stock issued under employee benefit plans (in shares)				32,000
Common stock issued under employee benefit plans	3			$ 0	3
Common stock issued and stock-based compensation expense				121,000
Common stock issued and stock-based compensation expense	9			$ 0	9
Dividends — common stock	(177)					(177)
Dividends — preferred stock										(15)	(15)	(16)	(16)
Preferred stock, shares outstanding, balance at end of period (in shares) at Sep. 30, 2023			11,000
Common stock, shares outstanding, balance at end of period (in shares) at Sep. 30, 2023				570,781,000
Stockholders' equity, balance at end of period at Sep. 30, 2023	$ 13,665		$ 1,056	$ 6	4,520	29,665		(573)	(21,009)
Preferred stock, shares outstanding, balance at beginning of period (in shares) at Dec. 31, 2023	10,700		11,000
Common stock, shares outstanding, balance at beginning of period (in shares) at Dec. 31, 2023				570,838,000
Stockholders' equity, balance at beginning of period at Dec. 31, 2023	$ 14,235		$ 1,056	$ 6	4,553	29,855		(225)	(21,010)
Stockholders' equity, balance at beginning of period (Accounting Standards update 2023-02) at Dec. 31, 2023		$ (37)					$ (37)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,244					3,244
Other comprehensive income	242							242
Purchases of treasury stock	(62)								(62)
Common stock issued under employee benefit plans (in shares)				80,000
Common stock issued under employee benefit plans	10			$ 0	10
Common stock issued and stock-based compensation expense				1,551,000
Common stock issued and stock-based compensation expense	70			$ 0	70
Dividends — common stock	$ (531)					(531)
Dividends — preferred stock										(31)	(31)	(31)	(31)
Preferred stock, shares outstanding, balance at end of period (in shares) at Sep. 30, 2024	10,700		11,000
Common stock, shares outstanding, balance at end of period (in shares) at Sep. 30, 2024				572,469,000
Stockholders' equity, balance at end of period at Sep. 30, 2024	$ 17,109		$ 1,056	$ 6	4,633	32,469		17	(21,072)
Preferred stock, shares outstanding, balance at beginning of period (in shares) at Jun. 30, 2024			11,000
Common stock, shares outstanding, balance at beginning of period (in shares) at Jun. 30, 2024				572,265,000
Stockholders' equity, balance at beginning of period at Jun. 30, 2024	16,010		$ 1,056	$ 6	4,603	31,807		(398)	(21,064)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	870					870
Other comprehensive income	415							415
Purchases of treasury stock	(8)								(8)
Common stock issued under employee benefit plans (in shares)				24,000
Common stock issued under employee benefit plans	3			$ 0	3
Common stock issued and stock-based compensation expense				180,000
Common stock issued and stock-based compensation expense	27			$ 0	27
Dividends — common stock	$ (177)					(177)
Dividends — preferred stock										$ (15)	$ (15)	$ (16)	$ (16)
Preferred stock, shares outstanding, balance at end of period (in shares) at Sep. 30, 2024	10,700		11,000
Common stock, shares outstanding, balance at end of period (in shares) at Sep. 30, 2024				572,469,000
Stockholders' equity, balance at end of period at Sep. 30, 2024	$ 17,109		$ 1,056	$ 6	$ 4,633	$ 32,469		$ 17	$ (21,072)

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Dividends declared, common stock (dollars per share)	$ 0.70	$ 0.70	$ 2.10	$ 2
Series C Preferred Stock [Member]
Dividends declared, preferred stock (dollars per share)	2,750	2,750	5,500	5,500
Series D Preferred Stock
Dividends declared, preferred stock (dollars per share)	$ 3,062.5	$ 3,062.5	$ 6,125	$ 6,125

Condensed Consolidated Statem_7

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows provided by operating activities
Net income	$ 3,244	$ 2,430
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	3,709	4,109
Deferred income taxes	84	(508)
Depreciation and amortization	269	354
Amortization of deferred revenues	(324)	(335)
Net losses on investments and other assets	45	40
Gain related to loans sold	(70)	0
Other, net	60	63
Changes in assets and liabilities:
Decrease (increase) in other assets	78	(436)
Decrease in accrued expenses and other liabilities	(650)	(30)
Net cash provided by operating activities	6,445	5,687
Cash flows provided by (used for) investing activities
Payments to Acquire Short-Term Investments	(734)	0
Maturities of available-for-sale investment securities	1,568	1,431
Purchases of available-for-sale investment securities	(2,480)	(2,627)
Maturities of held-to-maturity investment securities	12	12
Purchases of held-to-maturity investment securities	(35)	(49)
Proceeds from the sale of loans originated for investment	1,554	0
Net change in principal on loans originated for investment	(4,067)	(13,145)
Proceeds from the sale of other investments	2	4
Purchases of other investments	(44)	(60)
Proceeds from sale of premises and equipment	59	0
Purchases of premises and equipment	(205)	(235)
Net cash used for investing activities	(4,370)	(14,669)
Cash flows provided by (used for) financing activities
Net change in deposits	888	12,348
Proceeds from issuance of securitized debt	0	2,232
Maturities and repayment of securitized debt	(2,486)	(1,489)
Proceeds from issuance of other long-term borrowings	0	523
Maturities and repayments of other long-term borrowings	(751)	(1,808)
Proceeds from issuance of common stock	10	9
Purchases of treasury stock	(62)	(1,937)
Dividends paid on common and preferred stock	(579)	(560)
Net cash (used for) provided by financing activities	(2,980)	9,318
Net (decrease) increase in cash, cash equivalents and restricted cash	(905)	336
Cash, cash equivalents and restricted cash, at the beginning of the period	11,728	8,897
Cash, cash equivalents and restricted cash, at the end of the period	10,823	9,233
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	10,787	9,194
Restricted cash	36	39
Supplemental Cash Flow Information [Abstract]
Loan and Lease, Transfer from Held-in-Portfolio to Held-for-Sale	$ 8,484	$ 0

Background and Basis of Present

Background and Basis of Presentation	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background and Basis of Presentation	Background and Basis of Presentation Description of Business Discover Financial Services ("DFS" or the "Company") is a digital banking and payment services company. The Company is a bank holding company under the Bank Holding Company Act of 1956 and a financial holding company under the Gramm-Leach-Bliley Act. Therefore, the Company is subject to oversight, regulation and examination by the Board of Governors of the Federal Reserve System (the "Federal Reserve"). The Company provides digital banking products and services and payment services through its subsidiaries. The Company offers its customers credit card loans, personal loans, home loans and deposit products. The Company also operates the Discover Network, the PULSE network ("PULSE") and Diners Club International ("Diners Club"), collectively known as the Discover Global Network. The Discover Network processes transactions for Discover-branded credit and debit cards and provides payment transaction processing and settlement services. PULSE operates an electronic funds transfer network, providing financial institutions issuing debit cards on the PULSE network with access to automated teller machines ("ATMs") domestically and internationally, as well as merchant acceptance throughout the United States of America ("U.S.") for debit card transactions. Diners Club is a global payments network of licensees, which are generally financial institutions, that issue Diners Club branded credit and charge cards and/or provide card acceptance services. The Company manages its business activities in two segments, Digital Banking and Payment Services, based on the products and services provided. See Note 16: Segment Disclosures for a detailed description of each segment's operations and the allocation conventions used in business segment reporting. Sale of The Private Student Loan Portfolio In November 2023, the Company announced its Board of Directors had authorized management to explore the sale of its private student loan portfolio. The Company stopped accepting new applications for private student loans February 1, 2024, and as of June 30, 2024, the Company's private student loan portfolio was classified as loans held-for-sale. On July 17, 2024, Discover Bank entered into a purchase agreement to sell its private student loan portfolio and transfer servicing of the portfolio to a third-party servicer upon the sale. The purchase price payable to Discover Bank in the transaction represents a premium to the balances of principal and interest to be capitalized of the private student loan portfolio. The transaction is expected to be completed in multiple closings by the end of 2024, subject to the satisfaction or waiver of customary closing conditions. The first closing was executed during the three months ended September 30, 2024, resulting in the recognition of a $70 million gain recorded in other income on the condensed consolidated statements of income. As of September 30, 2024, the remaining principal balance of the private student loan portfolio, excluding interest to be capitalized, was approximately $8.5 billion, and based on certain assumptions the remaining proceeds are estimated to be up to approximately $9.0 billion. For more information, see Discover's Current Report on Form 8-K filed with the Securities and Exchange Commission (the "SEC") on July 17, 2024. Pending Merger with Capital One Financial Corporation On February 19, 2024, Discover and Capital One Financial Corporation ("Capital One") jointly announced that they entered into an agreement and plan of merger (the "Merger Agreement"), under which the companies will combine in an all-stock merger, which valued Discover at $35.3 billion based on the price of Capital One common stock on the last trading day before the public announcement of the merger. Under the terms of the Merger Agreement, holders of Discover common stock will receive 1.0192 shares of Capital One common stock for each share of Discover common stock they own. Capital One shareholders will own approximately 60% of the combined company and Discover shareholders will own approximately 40% of the combined company. The Merger Agreement contains customary representations and warranties, covenants and closing conditions. The Board of Directors of the combined company will have fifteen directors, consisting of twelve Capital One Board members and three Discover Board members to be named at a later date. For more information, see Discover’s Current Report on Form 8-K filed with the SEC on February 22, 2024. Completion of the proposed merger remains subject to approval by the Federal Reserve Board and the Office of the Comptroller of the Currency and other customary closing conditions, including the approval of both companies’ shareholders. Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. ("GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. In the opinion of management, the financial statements reflect all adjustments necessary for the fair presentation of results for the interim period. All such adjustments are of a normal, recurring nature. The preparation of financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and related disclosures. These estimates are based on information available as of the date of the condensed consolidated financial statements. The Company believes that the estimates used in the preparation of the condensed consolidated financial statements are reasonable. Actual results could differ from these estimates. These interim condensed consolidated financial statements should be read in conjunction with the Company's 2023 audited consolidated financial statements filed with the Company's annual report on Form 10-K/A for the year ended December 31, 2023. The condensed consolidated financial statements for the period ended September 30, 2023 have been restated as disclosed in the Company's annual report on Form 10-K/A for the year ended December 31, 2023. Certain prior year amounts have been reclassified to conform to the current period presentation. These reclassifications had no impact on the Company’s condensed consolidated financial condition, results of operations or changes in stockholders’ equity. Restatement of Financial Statements As reported in the second quarter of 2023, beginning in 2007, the Company incorrectly classified certain credit card accounts into its highest merchant and merchant acquirer pricing tier. The card product classification impacts the pricing and charging of discount and interchange revenue, which is recorded within discount and interchange revenue, net, on the consolidated statements of income. The Company determined that corrections to the financial statements for the impacts of the card product misclassification were required for prior periods presented in this Form 10-Q. Therefore, the Company has reflected these corrections to the condensed consolidated financial statements for prior periods presented in this Form 10-Q. Additionally, prior period amounts in the applicable notes to the condensed consolidated financial statements have been corrected. The impacts of the misclassification and subsequent corrections are contained entirely within the Digital Banking segment. Recently Issued Accounting Pronouncements (Not Yet Adopted) In November 2024, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses . This ASU aims to build a better understanding of an entity’s expenses through more detailed tabular disclosures surrounding certain costs and expenses (including but not limited to employee compensation, amortization of intangibles, and depreciation), defining and disclosing selling expense, and qualitatively describing remaining amounts not disaggregated in relevant expense captions. In addition, certain existing expense disclosures will be required to be presented within the same note and tabular format as prescribed by ASU No. 2024-03. The guidance is effective for the Company for the year ending December 31, 2027, and interim periods thereafter and can be applied on a prospective or retrospective basis. While the ASU implements further disclosure requirements, it does not change how an entity calculates and/or records its expenses, and it will have no impact on the Company’s consolidated financial condition, results of operations or cash flows. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures . This ASU enhances the transparency of income tax information through improvements to income tax disclosures primarily related to the rate reconciliation and income taxes paid. Entities are required to disaggregate the rate reconciliation (including percentages and reported amounts) by certain specified categories with additional disaggregation by nature and/or jurisdiction for items over a designated threshold. Income taxes paid (net of refunds received) must be disaggregated by federal, state and foreign taxes and separately by individual jurisdiction in which that amount for a particular jurisdiction is equal to or greater than five percent of total income taxes paid (net of refunds received). This annual disclosure guidance is effective for the Company for the year ending December 31, 2025 and can be adopted on either a prospective or retrospective basis. The Company expects to adopt this standard on a prospective basis. While the ASU implements further income tax disclosure requirements, it does not change how an entity determines its income tax obligation, and it will have no impact on the Company’s consolidated financial condition, results of operations or cash flows. In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures . The ASU requires disclosure of additional segment level information, particularly regarding significant segment expenses. Entities must disclose significant expense categories and amounts that are regularly provided to the chief operating decision maker ("CODM") and included in the reported segment measure of profit or loss. Other segment items must also be reported, which are those items that make up the difference between segment revenues less significant segment expenses and reported segment profit or loss. Additionally, entities must disclose the identity of the CODM and how they use the reported measures of segment profit or loss for decision making and assessing segment performance. The guidance is effective for the Company for the year ending December 31, 2024, and interim periods thereafter and requires retrospective application. While the ASU implements further segment disclosure requirements, it does not change how an entity identifies its operating or reportable segments, and it will have no impact on the Company’s consolidated financial condition, results of operations or cash flows.

Investments

Investments	9 Months Ended
	Sep. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Investments	Investments The Company's investment securities consist of the following (dollars in millions): September 30, December 31, U.S. Treasury bills (1) $ 735 $ — Total other short-term investments $ 735 $ — U.S. Treasury (2) and U.S. GSE (3) securities $ 14,185 $ 12,937 Residential mortgage-backed securities - Agency (4) 680 718 Total investment securities $ 14,865 $ 13,655 (1) Includes U.S. Treasury bills with maturity dates greater than 90 days but less than one year at the time of acquisition. (2) Includes $407 million and $320 million of U.S. Treasury securities pledged as swap collateral as of September 30, 2024 and December 31, 2023, respectively. (3) Consists of securities issued by the Federal Home Loan Bank ("FHLB"). (4) Primarily consists of securities issued by Fannie Mae, Freddie Mac, or Ginnie Mae. The amortized cost, gross unrealized gains and losses and fair value of available-for-sale and held-to-maturity investment securities are as follows (dollars in millions): Amortized Gross Gross Fair Value At September 30, 2024 Available-for-Sale Investment Securities (1) U.S. Treasury and U.S. GSE securities $ 14,058 $ 146 $ (19) $ 14,185 Residential mortgage-backed securities - Agency 412 — (7) 405 Total available-for-sale investment securities $ 14,470 $ 146 $ (26) $ 14,590 Held-to-Maturity Investment Securities (2) Residential mortgage-backed securities - Agency (3) $ 275 $ 2 $ (17) $ 260 Total held-to-maturity investment securities $ 275 $ 2 $ (17) $ 260 At December 31, 2023 Available-for-Sale Investment Securities (1) U.S. Treasury and U.S. GSE securities $ 12,971 $ 52 $ (86) $ 12,937 Residential mortgage-backed securities - Agency 480 — (15) 465 Total available-for-sale investment securities $ 13,451 $ 52 $ (101) $ 13,402 Held-to-Maturity Investment Securities (2) Residential mortgage-backed securities - Agency (3) $ 253 $ — $ (19) $ 234 Total held-to-maturity investment securities $ 253 $ — $ (19) $ 234 (1) Available-for-sale investment securities are reported at fair value. (2) Held-to-maturity investment securities are reported at amortized cost. (3) Amounts represent residential mortgage-backed securities ("RMBS") that were classified as held-to-maturity as they were entered into as a part of the Company's community reinvestment initiatives. The Company primarily invests in U.S. Treasury obligations and securities issued by a U.S. government agency ("Agency") or government-sponsored enterprise ("U.S. GSE"), which have long histories with no credit losses and are explicitly or implicitly guaranteed by the U.S. federal government. Therefore, management has concluded that there is no expectation of non-payment on its investment securities and does not record an allowance for credit losses on these investments. In addition, the Company does not have the intent to sell any available-for-sale securities in an unrealized loss position and does not believe it is more likely than not that it will be required to sell any such security before recovery of its amortized cost basis. The following table provides information about available-for-sale investment securities with aggregate gross unrealized losses and the length of time that individual investment securities have been in a continuous unrealized loss position (dollars in millions): Number of Securities in a Loss Position Less than 12 months More than 12 months Fair Unrealized Fair Unrealized At September 30, 2024 Available-for-Sale Investment Securities U.S. Treasury and U.S. GSE securities 31 $ 1,137 $ (2) $ 2,593 $ (17) Residential mortgage-backed securities - Agency 30 $ — $ — $ 405 $ (7) At December 31, 2023 Available-for-Sale Investment Securities U.S. Treasury and U.S. GSE securities 105 $ 3,513 $ (13) $ 3,978 $ (73) Residential mortgage-backed securities - Agency 31 $ — $ — $ 465 $ (15) There were no proceeds from sales or recognized gains or losses on available-for-sale securities during the three and nine months ended September 30, 2024 and 2023. See Note 8: Accumulated Other Comprehensive Income for unrealized gains and losses on available-for-sale securities during the three and nine months ended September 30, 2024 and 2023. Maturities of available-for-sale debt securities and held-to-maturity debt securities are provided in the following table (dollars in millions): At September 30, 2024 One Year After One After Five After Ten Total Available-for-Sale Investment Securities — Amortized Cost U.S. Treasury and U.S. GSE securities $ 2,193 $ 11,792 $ 73 $ — $ 14,058 Residential mortgage-backed securities - Agency (1) — 52 106 254 412 Total available-for-sale investment securities $ 2,193 $ 11,844 $ 179 $ 254 $ 14,470 Held-to-Maturity Investment Securities — Amortized Cost Residential mortgage-backed securities - Agency (1) $ — $ — $ — $ 275 $ 275 Total held-to-maturity investment securities $ — $ — $ — $ 275 $ 275 Available-for-Sale Investment Securities — Fair Values U.S. Treasury and U.S. GSE securities $ 2,183 $ 11,926 $ 76 $ — $ 14,185 Residential mortgage-backed securities - Agency (1) — 50 105 250 405 Total available-for-sale investment securities $ 2,183 $ 11,976 $ 181 $ 250 $ 14,590 Held-to-Maturity Investment Securities — Fair Values Residential mortgage-backed securities - Agency (1) $ — $ — $ — $ 260 $ 260 Total held-to-maturity investment securities $ — $ — $ — $ 260 $ 260 (1) Maturities of RMBS are reflective of the contractual maturities of the investment. Other Investments As a part of the Company’s community reinvestment initiatives, the Company has made equity investments in certain limited partnerships and limited liability companies that finance the construction and rehabilitation of affordable rental housing and stimulate economic development in low- to moderate-income communities. These investments are recorded within other assets on the Company’s condensed consolidated statements of financial condition. The Company has elected to account for its qualifying investments in Low Income Housing Tax Credit and New Markets Tax Credit programs under the proportional amortization method beginning January 1, 2024 on a modified retrospective basis. As of September 30, 2024, all of the Company's tax credit investments qualified for this election. Prior to 2024, these investments were accounted for using the equity method. Under the proportional amortization method, the cost of the investment is amortized in proportion to the income tax credits and other income tax benefits received, the net effect of which is recognized as a component of income tax expense on the condensed consolidated statements of income and within cash flows provided by operating activities on the condensed consolidated statements of cash flows. The Company earns a return primarily through tax credits allocated to the affordable housing projects and the community revitalization projects. The Company does not consolidate these investments as the Company does not have a controlling financial interest in the investee entities. The related commitments for future investments are recorded in accrued expenses and other liabilities within the consolidated statements of financial condition for delayed equity contributions that are unconditional and legally binding. Equity contributions that are contingent upon a future event are recognized when that contingent event becomes probable. As of September 30, 2024 and December 31, 2023, the Company had outstanding investments in these entities of $451 million and $514 million, respectively, and related liabilities for delayed equity contributions of $156 million and $187 million, respectively. During the three and nine months ended September 30, 2024, the Company recognized $15 million and $46 million of amortization, respectively. During the three and nine months ended September 30, 2024 the Company recognized $17 million and $52 million of income tax credits and other income tax benefits, respectively. Non-income tax benefits comprised only immaterial cash distributions from these investments during the three and nine months ended September 30, 2024. The Company holds non-controlling equity positions in several payment services entities and third-party venture capital funds, which invest in such entities. Most of the direct investments in such entities are not subject to equity method accounting because the Company does not have significant influence over the investee. The Company's investments in third-party venture capital funds represent limited partnership interests and are accounted for under the equity method. The common or preferred equity securities that the Company holds typically do not have readily determinable fair values. As a result, these investments are carried at cost minus impairment, if any. As of September 30, 2024 and December 31, 2023, the carrying value of these investments, which are recorded within other assets on the Company's condensed consolidated statements of financial condition, was $38 million and $35 million, respectively.

Loan Receivables

Loan Receivables	9 Months Ended
	Sep. 30, 2024
Receivables [Abstract]
Financing Receivables [Text Block]	Loan Receivables The Company's loans held-for-investment comprise two loan portfolio segments: credit card loans and other loans. The Company's classes of receivables within the two portfolio segments are depicted in the following table (dollars in millions): September 30, December 31, Loans held-for-sale (1)(2) $ 8,484 $ — Loan portfolio Credit card loans (3)(4) 100,489 102,259 Other loans (1) Private student loans (2) — 10,352 Personal loans 10,438 9,852 Other loans 7,582 5,946 Total other loans 18,020 26,150 Total loan portfolio 118,509 128,409 Total loan receivables 126,993 128,409 Allowance for credit losses (8,512) (9,283) Net loan receivables $ 118,481 $ 119,126 (1) Accrued interest receivable on private student, personal and other loans, which is presented as part of other assets in the Company's condensed consolidated statements of financial condition, was $372 million, $74 million and $28 million, respectively, at September 30, 2024 and $522 million, $69 million and $21 million, respectively, at December 31, 2023. (2) At September 30, 2024, the private student loan portfolio was classified as held-for-sale and there were $6.0 billion of private student loans in repayment. At December 31, 2023, the private student loan portfolio was classified as held-for-investment and there were $6.3 billion of private student loans in repayment. (3) Amounts include carrying values of $11.7 billion and $14.8 billion underlying investors' interest in trust debt at September 30, 2024 and December 31, 2023, respectively, and $16.9 billion and $15.6 billion in seller's interest at September 30, 2024 and December 31, 2023, respectively. See Note 4: Credit Card and Private Student Loan Securitization Activities for additional information. (4) Unbilled accrued interest receivable on credit card loans, which is presented as part of other assets in the Company's condensed consolidated statements of financial condition, was $726 million and $753 million at September 30, 2024 and December 31, 2023, respectively. Loans Held-for-Sale As of September 30, 2024, the Company's private student loans portfolio comprises the entirety of the Company’s loans held-for-sale balance. The Company includes its loans held-for-sale in loan receivables and carries these assets at the lower of amortized cost or fair value. The estimated fair value of loans held-for-sale is based on the pricing terms defined in the purchase agreement executed on July 17, 2024. An allowance for credit losses is not maintained for loans held-for-sale. Interest income on loans held-for-sale continues to accrue and is recognized in income based on the contractual rate of interest. As with the Company’s loans held-for-investment, accrued interest on loans held-for-sale is recorded in other assets in the Company’s condensed consolidated statements of financial condition. Accrued interest on private student loans as of September 30, 2024, was incorporated into the lower of amortized cost or fair value measurement of those loans. Credit Quality Indicators As part of credit risk management activities, on an ongoing basis, the Company reviews information related to the performance of a customer's account with the Company and information from credit bureaus, such as FICO or other credit scores, relating to the customer's broader credit performance. The Company actively monitors key credit quality indicators, including FICO scores and delinquency status, for its loan receivables. These indicators are important to understand the overall credit performance of the Company's customers and their ability to repay. FICO scores are generally obtained at the origination of the account and are refreshed monthly or quarterly thereafter to assist in predicting customer behavior. Historically, the Company has noted that accounts with FICO scores below 660 have larger delinquencies and credit losses than those with higher credit scores. Credit quality disclosures, including disclosures pertaining to loan modifications to borrowers experiencing financial difficulty, do not apply to loans carried at the lower of amortized cost or fair value. Therefore, loans held-for-sale are excluded from these disclosures. The following table provides the distribution of the amortized cost basis (excluding accrued interest receivable presented in other assets) by the most recent FICO scores available for the Company's customers for credit card and personal loan receivables (dollars in millions): Credit Risk Profile by FICO Score September 30, 2024 December 31, 2023 660 and Above Less than 660 660 and Above Less than 660 $ % $ % $ % $ % Credit card loans $ 80,277 80 % $ 20,212 20 % $ 82,238 80 % $ 20,021 20 % Personal loans by origination year 2024 $ 3,915 99 % $ 37 1 % 2023 3,533 95 % 192 5 % $ 5,149 98 % $ 100 2 % 2022 1,623 91 % 169 9 % 2,604 93 % 187 7 % 2021 588 90 % 67 10 % 1,049 92 % 91 8 % 2020 177 91 % 17 9 % 355 92 % 29 8 % Prior 100 83 % 20 17 % 247 86 % 41 14 % Total personal loans $ 9,936 95 % $ 502 5 % $ 9,404 95 % $ 448 5 % Delinquencies are an indicator of credit quality at a point in time. A loan balance is considered delinquent when contractual payments on the loan become 30 days past due. The amortized cost basis (excluding accrued interest receivable presented in other assets) of delinquent loans in the Company's loan portfolio is shown below for credit card and personal loan receivables (dollars in millions): September 30, 2024 December 31, 2023 30-89 Days 90 or Total Past 30-89 Days 90 or Total Past Credit card loans $ 1,974 $ 1,883 $ 3,857 $ 2,038 $ 1,917 $ 3,955 Personal loans by origination year 2024 $ 13 $ 3 $ 16 2023 55 19 74 $ 26 $ 8 $ 34 2022 38 15 53 44 16 60 2021 14 6 20 20 8 28 2020 4 1 5 7 2 9 Prior 3 3 6 7 5 12 Total personal loans $ 127 $ 47 $ 174 $ 104 $ 39 $ 143 Allowance for Credit Losses The following tables provide changes in the Company's allowance for credit losses (dollars in millions): For the Three Months Ended September 30, 2024 Credit Card Loans Private Student Loans Personal Loans Other Loans Total Loans Balance at June 30, 2024 $ 7,591 $ — $ 793 $ 97 $ 8,481 Additions Provision for credit losses (1) 1,327 — 111 35 1,473 Deductions Charge-offs (1,629) — (123) (4) (1,756) Recoveries 297 — 17 — 314 Net charge-offs (1,332) — (106) (4) (1,442) Balance at September 30, 2024 $ 7,586 $ — $ 798 $ 128 $ 8,512 For the Three Months Ended September 30, 2023 Credit Card Loans Private Student Loans Personal Loans Other Loans Total Loans Balance at June 30, 2023 $ 6,525 $ 849 $ 622 $ 68 $ 8,064 Additions Provision for credit losses (1) 1,518 52 93 8 1,671 Deductions Charge-offs (1,171) (40) (76) — (1,287) Recoveries 198 5 14 — 217 Net charge-offs (973) (35) (62) — (1,070) Balance at September 30, 2023 $ 7,070 $ 866 $ 653 $ 76 $ 8,665 For the Nine Months Ended September 30, 2024 Credit Card Loans Private Student Loans Personal Loans Other Loans Total Loans Balance at December 31, 2023 $ 7,619 $ 858 $ 722 $ 84 $ 9,283 Additions Provision for credit losses (1)(2) 4,083 (770) 383 53 3,749 Deductions Charge-offs (4,926) (100) (353) (9) (5,388) Recoveries 810 12 46 — 868 Net charge-offs (4,116) (88) (307) (9) (4,520) Balance at September 30, 2024 $ 7,586 $ — $ 798 $ 128 $ 8,512 For the Nine Months Ended September 30, 2023 Credit Card Loans Private Student Loans Personal Loans Other Loans Total Loans Balance at December 31, 2022 $ 5,883 $ 839 $ 595 $ 57 $ 7,374 Cumulative effect of ASU No. 2022-02 adoption (3) (66) — (2) — (68) Balance at January 1, 2023 5,817 839 593 57 7,306 Additions Provision for credit losses (1) 3,752 121 211 19 4,103 Deductions Charge-offs (3,101) (111) (194) — (3,406) Recoveries 602 17 43 — 662 Net charge-offs (2,499) (94) (151) — (2,744) Balance at September 30, 2023 $ 7,070 $ 866 $ 653 $ 76 $ 8,665 (1) Excludes a $31 million adjustment of the liability for expected credit losses on unfunded commitments for the three months ended September 30, 2023, and $40 million and $6 million for the nine months ended September 30, 2024 and 2023, respectively, as the liability is recorded in accrued expenses and other liabilities in the Company's condensed consolidated statements of financial condition. With the transfer of private student loans to the held-for-sale classification as of June 30, 2024, a liability for expected credit losses on unfunded commitments is no longer recorded. (2) Includes the adjustment to eliminate the allowance for credit losses upon classifying the private student loan portfolio as held-for-sale. (3) Represents the adjustment to the allowance for credit losses as a result of the adoption of ASU No. 2022-02 on January 1, 2023, which eliminated the requirement to apply discounted cash flow measurements for certain troubled debt restructurings. The allowance for credit losses was approximately $8.5 billion at September 30, 2024, which reflects a $31 million build from June 30, 2024, and a $771 million release from December 31, 2023. The build in the allowance for credit losses for the three months ended September 30, 2024 was primarily driven by the impact of loan growth in the Company's loan portfolio. The release in the allowance for credit losses for the nine months ended September 30, 2024 was driven by the reversal of the private student loans allowance due to the loans being classified as held-for-sale, partially offset by the impact of loan growth. The allowance estimation process begins with a loss forecast that uses certain macroeconomic variables and multiple macroeconomic scenarios among its inputs. In estimating the allowance at September 30, 2024, the Company used a macroeconomic forecast that projected the following amounts: (i) unemployment rate ending 2024 at 4.35% and, within the Company's reasonable and supportable period, peaking at 4.62% in the third quarter of 2025 and (ii) 2.54% growth rate in real gross domestic product in 2024. In estimating expected credit losses, the Company considered the uncertainties associated with borrower behavior and payment trends, as well as recent and expected macroeconomic conditions including those relating to consumer price inflation and the fiscal and monetary policy responses to that inflation. Federal Reserve officials believe trends in inflation and employment are supportive of a less restrictive monetary policy, as indicated by a reduction of the federal funds target range in September 2024 and signaling of further cuts over the remainder of 2024. However, the timing and magnitude of rate decreases will be dependent on trends in economic data, particularly inflation and labor market conditions, and monetary policy remains restrictive, which typically precedes weaker consumer credit conditions caused by rising unemployment as economic growth slows. While credit performance in the Company's lending portfolios has evolved in line with its expectations, the Company assessed the prospects for various macroeconomic outcomes in setting its allowance for credit losses. The forecast period the Company deemed to be reasonable and supportable was 18 months for all periods presented. The 18 months reasonable and supportable forecast period was deemed appropriate given the current economic conditions. For all periods presented, the Company determined that a reversion period of 12 months was appropriate for the same reason. The Company applied a weighted reversion method to provide a more reasonable transition to historical losses for all loan products for all periods presented. The net charge-offs for credit card loans and personal loans increased for the three and nine months ended September 30, 2024, when compared to the same periods in 2023, primarily driven by portfolio seasoning. Net charge-offs of principal are recorded against the allowance for credit losses, as shown in the preceding table. Information regarding net charge-offs of interest and fee revenues on credit card and other loans is as follows (dollars in millions): (1) For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 Interest and fees accrued subsequently charged-off, net of recoveries (recorded as a reduction of interest income) $ 274 $ 176 $ 831 $ 460 Fees accrued subsequently charged-off, net of recoveries (recorded as a reduction to other income) $ 61 $ 47 $ 196 $ 134 (1) Amounts presented in this table include charge-offs related to private student loans through June 30, 2024, the date those loans were transferred to held-for-sale classification . Gross principal charge-offs of the Company's loan portfolio are presented in the table below, on a year-to-date basis, for credit card and personal loan receivables (dollars in millions): For the Nine Months Ended September 30, 2024 2023 Credit card loans $ 4,926 $ 3,101 Personal loans by origination year 2024 $ 6 2023 125 $ 5 2022 132 74 2021 56 58 2020 18 26 Prior 16 31 Total personal loans $ 353 $ 194 Delinquent and Non-Accruing Loans The amortized cost basis (excluding accrued interest receivable presented in other assets) of delinquent and non-accruing loans in the Company's loan portfolio, which excludes loans held-for-sale, is shown below for each class of loan receivables (dollars in millions): (1) 30-89 Days 90 or Total Past 90 or Total Non-accruing (2) At September 30, 2024 Credit card loans $ 1,974 $ 1,883 $ 3,857 $ 1,845 $ 191 Other loans Personal loans 127 47 174 45 12 Other loans 44 30 74 5 79 Total other loans 171 77 248 50 91 Total loan portfolio $ 2,145 $ 1,960 $ 4,105 $ 1,895 $ 282 At December 31, 2023 Credit card loans $ 2,038 $ 1,917 $ 3,955 $ 1,881 $ 197 Other loans Personal loans 104 39 143 37 11 Other loans 39 19 58 3 53 Total other loans 143 58 201 40 64 Total loan portfolio $ 2,181 $ 1,975 $ 4,156 $ 1,921 $ 261 (1) The payment status of both modified and unmodified loans is included in this table. (2) The Company estimates that the gross interest income that would have been recorded under the original terms of non-accruing credit card loans was $9 million and $11 million for the three months ended September 30, 2024 and 2023, respectively, and $26 million and $29 million for the nine months ended September 30, 2024 and 2023, respectively. The Company does not separately track the amount of gross interest income that would have been recorded under the original terms of loans. Instead, the Company estimated this amount based on customers' current balances and most recent interest rates. Loan Modifications to Borrowers Experiencing Financial Difficulty The Company has internal loan modification programs that provide relief to credit card and personal loan borrowers who are experiencing financial hardship. The internal loan modification programs include both temporary and permanent programs, which vary by product. External loan modification programs, through third party consumer credit counseling agencies, are also available for credit card and personal loans. Those programs feature interest rate reductions, payment delays, term extensions, or a combination thereof. For credit card customers, the Company offers both temporary and permanent hardship programs. The temporary hardship programs consist of an interest rate reduction lasting for a period no longer than 12 months. Charging privileges on these accounts are generally suspended while in the program. However, if the customer meets certain criteria, charging privileges may be reinstated following completion of the program. The permanent modification program involves closing the account, changing the structure of the loan to a fixed payment loan with a maturity no longer than 72 months and reducing the interest rate on the loan. The permanent modification program does not typically provide for the forgiveness of unpaid principal, but may allow for the reversal of certain unpaid interest or fee assessments. The Company also makes permanent loan modifications for customers who request financial assistance through external sources, such as a consumer credit counseling agency program. These loans typically receive a reduced interest rate, typically continue to be subject to the original minimum payment terms and do not normally include waiver of unpaid principal, interest or fees. For personal loan customers, the Company offers various payment programs, including temporary and permanent programs, in certain situations. The temporary programs normally consist of reducing the minimum payment for no longer than 12 months and, in certain circumstances, the interest rate on the loan is reduced. The permanent programs involve extending the loan term and, in certain circumstances, reducing the interest rate on the loan. The total term of the loan, including modification, may not exceed nine years. The Company also allows permanent loan modifications for customers who request financial assistance through external sources, similar to the credit card customers discussed above. Payments are modified based on the new terms agreed upon with the credit counseling agency. In addition to the programs described above, the Company will in certain cases accept partial payment in full satisfaction of the outstanding receivable. This is a form of principal forgiveness also known as a settlement. The difference between the loan balance and the amount received at settlement is recorded as a charge-off. The Company monitors borrower performance after using payment programs. The Company believes the programs are useful in assisting customers experiencing financial difficulties and allowing them to make timely payments. In addition to helping customers with their credit needs, these programs are designed to maximize collections and ultimately the Company’s profitability. The Company plans to continue to use payment programs to provide relief to customers experiencing financial difficulties. The following table provides the period-end amortized cost basis, by modification category, of loans to borrowers experiencing financial difficulty that entered a modification program during the period (dollars in millions). Some of the loans presented in the table below may no longer be enrolled in a program at period-end: For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 Credit card loans (1)(2) Interest rate reduction $ 1,028 $ 685 $ 2,619 $ 1,712 Total credit card loans (3) $ 1,028 $ 685 $ 2,619 $ 1,712 % of total class of financing receivables 1.02 % 0.70 % 2.61 % 1.76 % Personal loans (1) Payment delay (4) $ 5 $ 4 $ 11 $ 8 Term extension (5) 11 9 30 24 Interest rate reduction and payment delay (4) 31 21 75 48 Interest rate reduction and term extension (5) 12 9 34 22 Total personal loans $ 59 $ 43 $ 150 $ 102 % of total class of financing receivables 0.57 % 0.45 % 1.44 % 1.07 % (1) Accrued interest receivable (including unbilled accrued interest receivable for credit card loans) on modified loans to borrowers experiencing financial difficulty, which is presented as part of other assets in the Company's condensed consolidated statements of financial condition, was immaterial at September 30, 2024 and 2023. (2) Accounts that entered a credit card loan modification program include $191 million and $487 million that were converted from revolving line-of-credit arrangements to term loans during the three and nine months ended September 30, 2024, respectively. Accounts that entered a credit card loan modification program include $120 million and $302 million that were converted from revolving line-of-credit arrangements to term loans during the three and nine months ended September 30, 2023, respectively. (3) For settlements, the amortized cost basis is zero at period-end and therefore there is no amount reported for principal forgiveness in the table above. See financial effects table below for principal forgiveness to borrowers experiencing financial difficulty. (4) The Company defines a payment delay as a temporary reduction in payments below the original contractually required payment amounts (e.g., interest only payments). The Company's credit card loan modification programs do not result in an other than insignificant delay in payment. (5) The Company defines term extensions as only those modifications for which the maturity date is extended beyond the original contractual maturity date by virtue of a change in terms other than a payment delay as defined above. Modifications to credit card loans are not considered term extensions because credit card loans do not have a fixed repayment term. The following table provides information on the financial effects of loan modifications to borrowers experiencing financial difficulty, by modification type, made during the period (dollars in millions): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 Credit card loans Weighted-average interest rate reduction 14.47 % 13.84 % 14.45 % 13.68 % Principal forgiven $ 62 $ 35 $ 166 $ 81 Interest and fees forgiven (1) $ 58 $ 30 $ 160 $ 77 Personal loans Weighted-average interest rate reduction 14.01 % 12.30 % 13.62 % 12.01 % Weighted-average term extension (in months) 39 38 40 38 Payment delay duration (in months) (2) 6 to 12 6 to 12 6 to 12 6 to 12 (1) Represents the amount of interest and fees forgiven resulting from accounts entering into a credit card loan modification program and pre-charge off settlements. Interest and fees forgiven are reversed against the respective line items in the condensed consolidated statements of income. (2) For personal loan payment delays, the Company limits this assistance to a life of loan maximum of 12 months. Loan receivables that have been modified are subject to the same requirements for the accrual of expected credit loss over their expected remaining lives as for unmodified loans. The allowance for credit losses incorporates modeling of historical loss data and thereby captures the higher risk associated with modified loans to borrowers experiencing financial difficulty based on their account attributes. The following table presents the payment status and period-end amortized cost basis, by class of loan receivable, of loans that were modified to borrowers experiencing financial difficulty during the 12 months preceding each of the periods presented (dollars in millions): (1) Current 30-89 Days 90 or At September 30, 2024 Credit card loans $ 2,677 $ 293 $ 222 Personal loans 147 29 6 Total $ 2,824 $ 322 $ 228 At December 31, 2023 Credit card loans $ 1,882 $ 252 $ 196 Personal loans 109 20 4 Total $ 1,991 $ 272 $ 200 (1) This table includes any loan that entered a modification program during the preceding 12 months without regard to whether it remained in a modification program as of the reporting date. The following table presents the defaulted amount and period-end amortized cost basis, by modification category, of loans that defaulted during the period and were modified to borrowers experiencing financial difficulty during the 12 months preceding default (dollars in millions): For the Three Months Ended September 30, 2024 For the Nine Months Ended September 30, 2024 Defaulted Amount (1) Period-end Amortized Cost Basis Defaulted Amount (1) Period-end Amortized Cost Basis Credit card loans Interest rate reduction $ 263 $ 186 $ 658 $ 349 Total credit card loans $ 263 $ 186 $ 658 $ 349 Personal loans Payment delay $ 1 $ 1 $ 2 $ 1 Term extension 2 2 6 3 Interest rate reduction and payment delay 9 3 23 6 Interest rate reduction and term extension 6 5 15 7 Total personal loans $ 18 $ 11 $ 46 $ 17 For the Three Months Ended September 30, 2023 For the Nine Months Ended September 30, 2023 Defaulted Amount (1) Period-end Amortized Cost Basis Defaulted Amount (1) Period-end Amortized Cost Basis Credit card loans Interest rate reduction $ 120 $ 96 $ 203 $ 124 Total credit card loans $ 120 $ 96 $ 203 $ 124 Personal loans Payment delay $ — $ — $ 1 $ 1 Term extension 1 1 2 2 Interest rate reduction and payment delay 3 3 4 4 Interest rate reduction and term extension 3 3 3 3 Total personal loans $ 7 $ 7 $ 10 $ 10 (1) For purposes of this disclosure, a loan is considered to be defaulted when it is 60 days or more delinquent at month end and has advanced two stages of delinquency subsequent to modification. Loans that entered a modification program in any stage of delinquency but did not experience a further payment default are included in the payment status table above but are not counted as defaulted for purposes of this disclosure.

Credit Card and Private Student

Credit Card and Private Student Loan Securitization Activities	9 Months Ended
	Sep. 30, 2024
Variable Interest Entities Disclosure [Abstract]
Credit Card and Private Student Loan Securitization Activities	Credit Card and Private Student Loan Securitization Activities The Company's securitizations are accounted for as secured borrowings and the related trusts are treated as consolidated subsidiaries of the Company. For a description of the Company's principles of consolidation with respect to VIEs, see Note 1: Background and Basis of Presentation to the consolidated financial statements in the Company's annual report on Form 10-K/A for the year ended December 31, 2023. Credit Card Securitization Activities The Company accesses the term asset securitization market through Discover Card Master Trust I ("DCMT") and Discover Card Execution Note Trust ("DCENT"). Credit card loan receivables are transferred into DCMT and beneficial interests in DCMT are transferred into DCENT. DCENT issues debt securities to investors that are reported primarily in long-term borrowings. The DCENT debt structure consists of four classes of securities (DiscoverSeries Class A, B, C and D notes), with the most senior class generally receiving a triple-A rating. To issue senior, higher-rated classes of notes, it is necessary to obtain the appropriate amount of credit enhancement, generally through the issuance of junior, lower-rated or more highly subordinated classes of notes. Wholly-owned subsidiaries of Discover Bank hold the subordinated classes of notes. The Company is exposed to credit risk associated with trust receivables as of the balance sheet date through the retention of these subordinated interests. The estimate of expected credit losses on trust receivables is included in the allowance for credit losses estimate. The Company's retained interests in the trust's assets, consisting of investments in DCENT notes held by subsidiaries of Discover Bank, constitute intercompany positions that are eliminated in the preparation of the Company's condensed consolidated statements of financial condition. Upon transfer of credit card loan receivables to the trust, the receivables and certain cash flows derived from them become restricted for use in meeting obligations to the trust's creditors. Further, the transferred credit card loan receivables are owned by the trust and are not available to the Company's third-party creditors. The trusts have ownership of cash balances, the amounts of which are reported in restricted cash within the Company's condensed consolidated statements of financial condition. Except for the seller's interest in trust receivables, the Company's interests in trust assets are generally subordinate to the interests of third-party investors in trust debt and, as such, may not be realized by the Company if needed to absorb deficiencies in cash flows that are allocated to those investors. Apart from the restricted assets related to securitization activities, the investors and the securitization trusts have no recourse to the Company's other assets or the Company's general credit for a shortage in cash flows. The carrying values of these restricted assets, which are presented on the Company's condensed consolidated statements of financial condition as relating to securitization activities, are shown in the following table (dollars in millions): September 30, December 31, Restricted cash $ 29 $ 36 Investors' interests held by third-party investors 9,250 11,725 Investors' interests held by wholly-owned subsidiaries of Discover Bank 2,459 3,117 Seller's interest 16,934 15,598 Loan receivables (1) 28,643 30,440 Allowance for credit losses allocated to securitized loan receivables (1) (1,334) (1,347) Net loan receivables 27,309 29,093 Other assets 3 2 Carrying value of assets of consolidated variable interest entities $ 27,341 $ 29,131 (1) The Company maintains its allowance for credit losses at an amount equal to lifetime expected credit losses associated with all loan receivables, which includes all loan receivables in the trusts. Therefore, the credit risk associated with the transferred receivables is fully reflected on the Company's statements of financial condition in accordance with GAAP. The debt securities issued by the consolidated trusts are subject to credit, payment and interest rate risks on the transferred credit card loan receivables. To protect investors in the securities, there are certain features or triggering events that will cause an early amortization of the debt securities, including triggers related to the impact of the performance of the trust receivables on the availability and adequacy of cash flows to meet contractual requirements. As of September 30, 2024, no economic or other early amortization events have occurred. The Company continues to own and service the accounts that generate the loan receivables held by the trusts. Discover Bank receives servicing fees from the trusts based on a percentage of the monthly investor principal balance outstanding. Although the fee income to Discover Bank offsets the fee expense to the trusts and thus is eliminated in consolidation, failure to service the transferred loan receivables in accordance with contractual requirements could lead to a termination of the servicing rights and the loss of future servicing income, net of related expenses. Private Student Loan Securitization Activities The Company's private student loan trust receivables reported in loan receivables and the related debt issued by the trust reported in long-term borrowings were immaterial as of September 30, 2024 and December 31, 2023. The amounts are included, together with amounts related to the Company's credit card securitizations, in the supplemental information about assets and liabilities of consolidated variable interest entities, which is presented with the Company's condensed consolidated statements of financial condition.

Deposits

Deposits	9 Months Ended
	Sep. 30, 2024
Deposits [Abstract]
Deposits	Deposits The Company obtains deposits from consumers directly or through affinity relationships ("direct-to-consumer deposits"). Additionally, the Company obtains deposits through third-party securities brokerage firms that offer the Company's deposits to their customers ("brokered deposits"). Direct-to-consumer deposit products include savings accounts, certificates of deposit, money market accounts, IRA savings accounts, IRA certificates of deposit and checking accounts. Brokered deposit products include certificates of deposit and sweep accounts. The following table summarizes certificates of deposits maturing over the remainder of this year, over each of the next four years and thereafter (dollars in millions): At September 30, 2024 2024 $ 10,208 2025 23,052 2026 4,914 2027 4,521 2028 2,209 Thereafter 1,172 Total $ 46,076

Long-Term Borrowings

Long-Term Borrowings	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Long-Term Borrowings	Long-Term Borrowings Long-term borrowings consist of borrowings having original maturities of one year or more. The following table provides a summary of the Company's long-term borrowings and weighted-average interest rates on outstanding balances (dollars in millions): September 30, 2024 December 31, 2023 Maturity Interest Weighted-Average Interest Rate Outstanding Amount Outstanding Amount Securitized Debt Fixed-rate asset-backed securities (1) 2025-2026 1.03% - 5.03% 3.55% $ 8,503 $ 10,003 Floating-rate asset-backed securities 2024 — — — 925 Total Discover Card Master Trust I and Discover Card Execution Note Trust 8,503 10,928 Floating-rate asset-backed security (2)(3) 2031 9.00% 9.00% 54 65 Total private student loan securitization trust 54 65 Total long-term borrowings - owed to securitization investors 8,557 10,993 Discover Financial Services (Parent Company) Fixed-rate senior notes 2024-2032 3.75% - 6.70% 4.68% 3,339 3,336 Fixed-rate retail notes 2025-2031 3.25% - 4.40% 3.82% 138 140 Fixed to floating-rate senior notes (4) 2034 7.96% 7.96% 993 993 Discover Bank Fixed-rate senior bank notes (1) 2026-2030 2.70% - 4.65% 3.82% 2,846 3,571 Fixed-rate subordinated bank notes 2028 5.97% 5.97% 506 500 Fixed-rate Federal Home Loan Bank advances 2030 4.77% - 4.82% 4.82% 523 523 Floating-rate Federal Home Loan Bank advances (5) 2024 4.99% - 5.09% 5.09% 525 525 Total long-term borrowings $ 17,427 $ 20,581 (1) The Company uses interest rate swaps to hedge portions of these long-term borrowings against changes in fair value attributable to changes in the applicable benchmark interest rates. The use of these interest rate swaps impacts the carrying value of the debt. See Note 15: Derivatives and Hedging Activities. (2) The private student loan securitization trust floating-rate asset-backed security includes an issuance with the following interest rate term: Prime rate + 100 basis points as of September 30, 2024. (3) Repayment of this debt is dependent upon the timing of principal and interest payments on the underlying private student loans. The date shown represents the final maturity date. (4) The fixed to floating-rate senior notes include a rate reset on November 2, 2033, to a floating rate based on compounded SOFR + 3.370%. (5) The floating-rate FHLB advances include interest rate terms based on SOFR plus a spread ranging from 16 to 26 basis points as of September 30, 2024. The following table summarizes long-term borrowings maturing over the remainder of this year, over each of the next four years and thereafter (dollars in millions): September 30, 2024 2024 $ 1,025 2025 6,174 2026 4,941 2027 1,002 2028 1,452 Thereafter 2,833 Total $ 17,427 As a member of the FHLB of Chicago, the Company has access to both short- and long-term advance structures with maturities ranging from overnight to 30 years. As of September 30, 2024, the Company had total committed borrowing capacity of $4.9 billion based on the amount and type of assets pledged, of which the outstanding balance was comprised of $1.0 billion in long-term advances. As of December 31, 2023, the Company had total committed borrowing capacity of $3.6 billion based on the amount and type of assets pledged, of which the outstanding balance was comprised of $1.0 billion in long-term advances. These advances are presented as short- or long-term borrowings on the condensed consolidated statements of financial condition based on the contractual maturity at origination. Additionally, the Company has access to committed borrowing capacity through private securitizations to support the funding of its credit card loan receivables. As of September 30, 2024 and December 31, 2023, the total commitment of secured credit facilities through private providers was $3.5 billion, $750 million of which was outstanding at each of the reporting dates as a short-term advance and presented as short-term borrowings on the condensed consolidated statements of financial condition. Access to the unused portions of the secured credit facilities is subject to the terms of the agreements with each of the providers. The secured credit facilities have various expirations in 2025 and 2026. Borrowings outstanding under each facility bear interest at a margin above the Term Secured Overnight Financing Rate ("SOFR") or the asset-backed commercial paper costs of each provider. The terms of each agreement provide for a commitment fee to be paid on the unused capacity and include various affirmative and negative covenants, including performance metrics and legal requirements similar to those required to issue any term securitization transaction.

Preferred Stock (Notes)

Preferred Stock (Notes)	9 Months Ended
	Sep. 30, 2024
Equity [Abstract]
Preferred Stock	Preferred Stock The table below presents a summary of the Company's non-cumulative perpetual preferred stock that is outstanding at September 30, 2024 (dollars in millions, except per depositary share amounts): Series Description Initial Issuance Date Liquidation Preference and Redemption Price per Depositary Share (1) Per Annum Dividend Rate in effect at September 30, 2024 Total Depositary Shares Authorized, Issued and Outstanding Carrying Value September 30, 2024 December 31, 2023 September 30, 2024 December 31, 2023 C (2)(3)(4) Fixed-to-Floating Rate 10/31/2017 $ 1,000 5.500 % 570,000 570,000 $ 563 $ 563 D (2)(5)(6) Fixed-Rate Reset 6/22/2020 $ 1,000 6.125 % 500,000 500,000 493 493 Total Preferred Stock 1,070,000 1,070,000 $ 1,056 $ 1,056 (1) Redeemable at the redemption price plus declared and unpaid dividends. (2) Issued as depositary shares, each representing 1/100 th interest in a share of the corresponding series of preferred stock. Each preferred share has a par value of $0.01. (3) Redeemable at the Company’s option, subject to regulatory approval, either (i) in whole or in part on any dividend payment date on or after October 30, 2027, or (ii) in whole but not in part, at any time within 90 days following a regulatory capital treatment event (as defined in the certificate of designations for the Series C preferred stock). (4) Any dividends declared are payable semi-annually in arrears at a rate of 5.500% per annum until October 30, 2027. Thereafter, dividends declared will be payable quarterly in arrears at a floating rate equal to 3-month Term SOFR plus a spread of 3.338% per annum. (5) Redeemable at the Company’s option, subject to regulatory approval, either (i) in whole or in part during the three-month period prior to, and including, each reset date (as defined in the certificate of designations for the Series D preferred stock) or (ii) in whole but not in part, at any time within 90 days following a regulatory capital treatment event (as defined in the certificate of designations for the Series D Preferred Stock). (6) Any dividends declared are payable semi-annually in arrears at a rate of 6.125% per annum until September 23, 2025, after which the dividend rate will reset every 5 years to a fixed annual rate equal to the 5-year Treasury plus a spread of 5.783%.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2024
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income Changes in each component of accumulated other comprehensive (loss) income ("AOCI") were as follows (dollars in millions): Unrealized (Losses) Gains on Available-for-Sale Investment Securities, Net of Tax (Losses) Gains on Cash Flow Hedges, Net of Tax Losses on Pension Plan, Net of Tax AOCI For the Three Months Ended September 30, 2024 Balance at June 30, 2024 $ (148) $ (70) $ (180) $ (398) Net change 239 176 — 415 Balance at September 30, 2024 $ 91 $ 106 $ (180) $ 17 For the Three Months Ended September 30, 2023 Balance at June 30, 2023 $ (195) $ (86) $ (189) $ (470) Net change (83) (20) — (103) Balance at September 30, 2023 $ (278) $ (106) $ (189) $ (573) For the Nine Months Ended September 30, 2024 Balance at December 31, 2023 $ (37) $ (8) $ (180) $ (225) Net change 128 114 — 242 Balance at September 30, 2024 $ 91 $ 106 $ (180) $ 17 For the Nine Months Ended September 30, 2023 Balance at December 31, 2022 $ (136) $ (14) $ (189) $ (339) Net change (142) (92) — (234) Balance at September 30, 2023 $ (278) $ (106) $ (189) $ (573) The following table presents each component of other comprehensive income ("OCI") before reclassifications and amounts reclassified from AOCI for each component of OCI before- and after-tax (dollars in millions): Before Tax Tax (Expense) Benefit Net of Tax For the Three Months Ended September 30, 2024 Available-for-Sale Investment Securities Net unrealized holding gains arising during the period $ 316 $ (77) $ 239 Net change $ 316 $ (77) $ 239 Cash Flow Hedges Net unrealized gains arising during the period $ 200 $ (48) $ 152 Amounts reclassified from AOCI 31 (7) 24 Net change $ 231 $ (55) $ 176 For the Three Months Ended September 30, 2023 Available-for-Sale Investment Securities Net unrealized holding losses arising during the period $ (111) $ 28 $ (83) Net change $ (111) $ 28 $ (83) Cash Flow Hedges Net unrealized losses arising during the period $ (55) $ 13 $ (42) Amounts reclassified from AOCI 29 (7) 22 Net change $ (26) $ 6 $ (20) For the Nine Months Ended September 30, 2024 Available-for-Sale Investment Securities Net unrealized holding gains arising during the period $ 169 $ (41) $ 128 Net change $ 169 $ (41) $ 128 Cash Flow Hedges Net unrealized gains arising during the period $ 38 $ (9) $ 29 Amounts reclassified from AOCI 112 (27) 85 Net change $ 150 $ (36) $ 114 For the Nine Months Ended September 30, 2023 Available-for-Sale Investment Securities Net unrealized holding losses arising during the period $ (188) $ 46 $ (142) Net change $ (188) $ 46 $ (142) Cash Flow Hedges Net unrealized losses arising during the period $ (172) $ 42 $ (130) Amounts reclassified from AOCI 50 (12) 38 Net change $ (122) $ 30 $ (92)

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The following table presents the calculation of the Company's effective income tax rate (dollars in millions): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 (As Restated) (As Restated) Income before income taxes $ 1,192 $ 761 $ 4,372 $ 3,154 Income tax expense $ 322 $ 175 $ 1,128 $ 724 Effective income tax rate 27.0 % 23.0 % 25.8 % 23.0 % The effective tax rate increased for the three and nine months ended September 30, 2024, as compared to the same periods in 2023, due to the adoption of the proportional amortization method for qualifying tax credit investments effective January 1, 2024, and the recognition of a charge representing potential non-deductible regulatory penalties related to the card product misclassification. The Company is subject to examination by the Internal Revenue Service and tax authorities in various state, local and foreign tax jurisdictions. The Company's federal income tax filings are open to examinations for the tax years ended December 31, 2020 and forward. The Company regularly assesses the likelihood of additional assessments or settlements in each of the taxing jurisdictions. At this time, the potential change in unrecognized tax benefits is expected to be immaterial over the next 12 months. The Company believes that its reserves are sufficient to cover any tax, penalties and interest that would result from such examinations.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following table presents the calculation of basic and diluted earnings per share ("EPS") (dollars and shares in millions, except per share amounts): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 (As Restated) (As Restated) Numerator Net income $ 870 $ 586 $ 3,244 $ 2,430 Preferred stock dividends (31) (31) (62) (62) Net income available to common stockholders 839 555 3,182 2,368 Income allocated to participating securities (5) (5) (20) (17) Net income allocated to common stockholders $ 834 $ 550 $ 3,162 $ 2,351 Denominator Weighted-average shares of common stock outstanding 251 250 251 255 Weighted-average shares of common stock outstanding and common stock equivalents 251 250 251 255 Basic earnings per common share $ 3.32 $ 2.21 $ 12.61 $ 9.23 Diluted earnings per common share $ 3.32 $ 2.21 $ 12.61 $ 9.22 Anti-dilutive securities were not material and had no impact on the computation of diluted EPS for the three and nine months ended September 30, 2024 and 2023.

Capital Adequacy

Capital Adequacy	9 Months Ended
	Sep. 30, 2024
Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]
Capital Adequacy	Capital Adequacy DFS is subject to the capital adequacy guidelines of the Federal Reserve. Discover Bank, the Company's banking subsidiary, is subject to various regulatory capital requirements as administered by the Federal Deposit Insurance Corporation ("FDIC"). Failure to meet minimum capital requirements can result in the initiation of certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could limit the Company's business activities and have a direct material effect on the financial condition and operating results of DFS and Discover Bank. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, DFS and Discover Bank must meet specific risk-based capital requirements and leverage ratios that involve quantitative measures of assets, liabilities and certain off-balance sheet items, as calculated under regulatory guidelines. Capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors. DFS and Discover Bank are subject to regulatory and capital rules issued by the Federal Reserve and FDIC, respectively, under the Basel Committee's December 2010 framework ("Basel III rules"). Under the Basel III rules, DFS and Discover Bank are classified as "standardized approach" entities. Standardized approach entities are defined as U.S. banking organizations with consolidated total assets over $50 billion but not exceeding $250 billion and consolidated total on-balance sheet foreign exposure less than $10 billion. In accordance with the final rule on the impact of current expected credit losses ("CECL") on regulatory capital, the Company has elected to phase in the impact over three years beginning in 2022. Accordingly, the Company's Common Equity Tier 1 ("CET1") capital ratios are higher than they otherwise would have been. The Company's CET1 capital ratios will continue to be favorably impacted by this election over the phase-in period, which ends December 31, 2024. As of September 30, 2024 and December 31, 2023, DFS and Discover Bank met all Basel III minimum capital ratio requirements to which they were subject. DFS and Discover Bank also met the requirements to be considered "well-capitalized" under Regulation Y and prompt corrective action rules, respectively. There have been no conditions or events that management believes have changed DFS' or Discover Bank's category. To be categorized as "well-capitalized", DFS and Discover Bank must maintain minimum capital ratios outlined in the table below. The following table shows the actual capital amounts and ratios of DFS and Discover Bank and comparisons of each to the regulatory minimum and "well-capitalized" requirements (dollars in millions): Actual Minimum Capital Capital Requirements Amount Ratio (1) Amount Ratio Amount (2) Ratio (2) (As Restated) (As Restated) (As Restated) (As Restated) September 30, 2024 Total capital (to risk-weighted assets) Discover Financial Services $ 19,379 14.9 % $ 10,407 ≥8.0% $ 13,009 ≥10.0% Discover Bank $ 17,611 13.7 % $ 10,266 ≥8.0% $ 12,832 ≥10.0% Tier 1 capital (to risk-weighted assets) Discover Financial Services $ 17,373 13.4 % $ 7,805 ≥6.0% $ 7,805 ≥6.0% Discover Bank $ 14,877 11.6 % $ 7,699 ≥6.0% $ 10,266 ≥8.0% Tier 1 capital (to average assets) Discover Financial Services $ 17,373 11.4 % $ 6,080 ≥4.0% N/A N/A Discover Bank $ 14,877 9.9 % $ 6,012 ≥4.0% $ 7,515 ≥5.0% Common Equity Tier 1 (to risk-weighted assets) Discover Financial Services $ 16,317 12.5 % $ 5,854 ≥4.5% N/A N/A Discover Bank $ 14,877 11.6 % $ 5,775 ≥4.5% $ 8,341 ≥6.5% December 31, 2023 Total capital (to risk-weighted assets) Discover Financial Services $ 17,399 13.2 % $ 10,509 ≥8.0% $ 13,137 ≥10.0% Discover Bank $ 16,409 12.7 % $ 10,381 ≥8.0% $ 12,976 ≥10.0% Tier 1 capital (to risk-weighted assets) Discover Financial Services $ 15,279 11.6 % $ 7,882 ≥6.0% $ 7,882 ≥6.0% Discover Bank $ 13,459 10.4 % $ 7,786 ≥6.0% $ 10,381 ≥8.0% Tier 1 capital (to average assets) Discover Financial Services $ 15,279 10.3 % $ 5,915 ≥4.0% N/A N/A Discover Bank $ 13,459 9.2 % $ 5,833 ≥4.0% $ 7,292 ≥5.0% Common Equity Tier 1 (to risk-weighted assets) Discover Financial Services $ 14,223 10.8 % $ 5,911 ≥4.5% N/A N/A Discover Bank $ 13,459 10.4 % $ 5,839 ≥4.5% $ 8,435 ≥6.5% (1) Capital ratios are calculated based on the Basel III standardized approach rules, subject to applicable transition provisions, including CECL transition provisions. (2) The Basel III rules do not establish well-capitalized thresholds for these measures for bank holding companies. Existing well-capitalized thresholds established in the Federal Reserve's Regulation Y have been included where available.

Commitments, Contingencies and

Commitments, Contingencies and Guarantees	9 Months Ended
	Sep. 30, 2024
Commitments Contingencies and Guarantees [Abstract]
Commitments, Contingencies and Guarantees	Commitments, Contingencies and Guarantees In the normal course of business, the Company enters into a number of off-balance sheet commitments, transactions and obligations under guarantee arrangements that expose the Company to varying degrees of risk. The Company's commitments, contingencies and guarantee relationships are described below. Commitments Unused Credit Arrangements At September 30, 2024, the Company had unused credit arrangements for loans of approximately $233.7 billion. Such arrangements arise primarily from agreements with customers for unused lines of credit on certain credit cards and certain other loan products, provided there is no violation of conditions in the related agreements. These arrangements, substantially all of which the Company can terminate at any time and which do not necessarily represent future cash requirements, are periodically reviewed based on account usage, customer creditworthiness, loan qualification and the cost of capital. As the Company’s credit card loans are unconditionally cancellable, no liability for expected credit losses is required for unused lines of credit. For all other loans, the Company records a liability for expected credit losses for unfunded commitments, which is presented as part of accrued expenses and other liabilities in the condensed consolidated statements of financial condition. Contingencies See Note 13: Litigation and Regulatory Matters for a description of potential liability arising from pending litigation or regulatory proceedings involving the Company. Guarantees The Company has obligations under certain guarantee arrangements, including contracts, indemnification agreements and representations and warranties, which contingently require the Company to make payments to the guaranteed party based on changes in an underlying asset, liability or equity security of a guaranteed party, rate or index. Also included as guarantees are contracts that contingently require the Company to make payments to a guaranteed party based on another entity's failure to perform under an agreement. The Company's use of guarantees is disclosed below by type of guarantee. Securitizations Representations and Warranties As part of the Company's financing activities, the Company provides representations and warranties that certain assets pledged as collateral in secured borrowing arrangements conform to specified guidelines. Due diligence is performed by the Company, which is intended to ensure that asset guideline qualifications are met. If the assets pledged as collateral do not meet certain conforming guidelines, the Company may be required to replace, repurchase or sell such assets. In its credit card securitization activities, the Company would replace nonconforming receivables through the allocation of excess seller's interest or from additional transfers from the unrestricted pool of receivables. If the Company could not add enough receivables to satisfy the requirement, an early amortization (or repayment) of investors' interests would be triggered. In its student loan securitizations, the Company would generally repurchase the loans from the trust at the outstanding principal amount plus interest. The maximum potential amount of future payments the Company could be required to make would be equal to the current outstanding balances of third-party investor interests in credit card asset-backed securities and the principal amount of any private student loan secured borrowings, plus any unpaid interest for the corresponding secured borrowings. The Company has recorded substantially all of the maximum potential amount of future payments in long-term borrowings on the Company's condensed consolidated statements of financial condition. The Company has not recorded any incremental contingent liability associated with its secured borrowing representations and warranties. Management believes that the probability of having to replace, repurchase or sell assets pledged as collateral under secured borrowing arrangements, including an early amortization event, is low. Counterparty Settlement Guarantees Diners Club and DFS Services LLC (on behalf of PULSE) have various counterparty exposures, which are listed below: • Merchant Guarantee . Diners Club has entered into contractual relationships with certain international merchants, which generally include travel-related businesses, for the benefit of all Diners Club licensees. The licensees hold the primary liability to settle the transactions of their customers with these merchants. However, Diners Club retains a counterparty exposure if a licensee fails to meet its financial payment obligation to one of these merchants. • ATM Guarantee. PULSE entered into contractual relationships with certain international ATM acquirers in which DFS Services LLC retains counterparty exposure if an issuer fails to fulfill its settlement obligation. • Global Network Alliance Guarantee . Discover Network, Diners Club and PULSE have entered into contractual relationships with certain international payment networks in which DFS Services LLC retains the counterparty exposure if a network fails to fulfill its settlement obligation. The maximum potential amount of future payments related to such contingent obligations is dependent upon the transaction volume processed between the time a potential counterparty defaults on its settlement and the time at which the Company disables the settlement of any further transactions for the defaulting party. The Company has some contractual remedies to offset these counterparty settlement exposures (such as letters of credit or pledged deposits), however, there is no limitation on the maximum amount the Company may be liable to pay. The actual amount of the potential exposure cannot be quantified as the Company cannot determine whether particular counterparties will fail to meet their settlement obligations. In the event all licensees and/or issuers were to become unable to settle their transactions, the Company estimates its maximum potential counterparty exposures to these settlement guarantees would be approximately $120 million as of September 30, 2024. The Company believes that the estimated amounts of maximum potential future payments are not representative of the Company's actual potential loss exposure given Diners Club's and PULSE's insignificant historical losses from these counterparty exposures. As of September 30, 2024, the Company had not recorded any contingent liability in the condensed consolidated statements of financial condition for these counterparty exposures and management believes that the probability of any payments under these arrangements is low. Discover Network Merchant Chargeback Guarantees The Company operates the Discover Network, issues payment cards and permits third parties to issue payment cards. The Company is contingently liable for certain transactions processed on the Discover Network in the event of a dispute between the payment card customer and a merchant. The contingent liability arises if the disputed transaction involves a merchant or merchant acquirer with whom the Discover Network has a direct relationship. If a dispute is resolved in the customer's favor, the Discover Network will credit or refund the disputed amount to the Discover Network card issuer, who in turn credits its customer's account. The Discover Network will then charge back the disputed amount of the payment card transaction to the merchant or merchant acquirer, where permitted by the applicable agreement, to seek recovery of amounts already paid to the merchant for payment card transactions. If the Discover Network is unable to collect the amount subject to dispute from the merchant or merchant acquirer (e.g., in the event of merchant default or dissolution or after expiration of the time period for chargebacks in the applicable agreement), the Discover Network will bear the loss for the amount credited or refunded to the customer. In most instances, a loss by the Discover Network is unlikely to arise in connection with payments on card transactions because most products or services are delivered when purchased and credits are issued by merchants on returned items in a timely fashion, thus minimizing the likelihood of cardholder disputes with respect to amounts paid by the Discover Network. However, where the product or service is not scheduled to be provided to the customer until a later date following the purchase, the likelihood of a contingent payment obligation by the Discover Network increases. Losses related to merchant chargebacks were not material for the three and nine months ended September 30, 2024 and 2023. The maximum potential amount of obligations of the Discover Network arising from such contingent obligations is estimated to be the portion of the total Discover Network transaction volume processed to date for which timely and valid disputes may be raised under applicable law and relevant issuer and customer agreements. There is no limitation on the maximum amount the Company may be liable to pay to issuers. However, the Company believes that such amount is not representative of the Company's actual potential loss exposure based on the Company's historical experience. The actual amount of the potential exposure cannot be quantified as the Company cannot determine whether the current or cumulative transaction volumes may include or result in disputed transactions. The following table summarizes certain information regarding merchant chargeback guarantees (dollars in millions): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 Aggregate sales transaction volume (1) $ 61,166 $ 65,490 $ 184,384 $ 192,173 (1) Represents transactions processed on the Discover Network for which a potential liability exists that, in aggregate, can differ from credit card sales volume. The Company did not record any contingent liability in the condensed consolidated financial statements for merchant chargeback guarantees as of September 30, 2024 and December 31, 2023. The Company mitigates the risk of potential loss exposure by withholding settlement from merchants, obtaining third-party guarantees, or obtaining escrow deposits or letters of credit from certain merchant acquirers or merchants that are considered a higher risk due to various factors such as time delays in the delivery of products or services. As of September 30, 2024 and December 31, 2023, the Company had escrow deposits and settlement withholdings of $9 million and $10 million, respectively, which are recorded in interest-bearing deposit accounts and accrued expenses and other liabilities on the Company's condensed consolidated statements of financial condition.

Litigation and Regulatory Matte

Litigation and Regulatory Matters	9 Months Ended
	Sep. 30, 2024
Loss Contingency [Abstract]
Litigation and Regulatory Matters	Litigation and Regulatory Matters In the normal course of business, from time to time, the Company has been named as a defendant in various legal actions, including arbitrations, class actions and other litigation, arising in connection with its activities. Certain of the actual or threatened legal actions include claims for substantial compensatory and/or punitive damages or claims for indeterminate amounts of damages. The litigation process is not predictable and can lead to unexpected results. The Company contests liability and/or the amount of damages as appropriate in each pending matter. The Company has historically offered its customers an arbitration clause in its customer agreements. The arbitration clause allows the Company and its customers to quickly and economically resolve disputes. Additionally, the arbitration clause has in some instances limited the costs of, and the Company's exposure to, litigation. Future legal and regulatory challenges and prohibitions may cause the Company to discontinue its offering and use of such clauses. From time to time, the Company is involved in legal actions challenging its arbitration clause. Bills may be periodically introduced in Congress to directly or indirectly prohibit the use of pre-dispute arbitration clauses. The Company is also involved, from time to time, in other reviews, investigations and proceedings (both formal and informal) by governmental agencies regarding the Company's business including, among other matters, regulatory, accounting, tax and other operational matters. The investigations and proceedings may result in significant adverse judgments, settlements, fines, penalties, injunctions, decreases in regulatory ratings, customer restitution or other relief. These outcomes could materially impact the Company's condensed consolidated financial statements, increase its cost of operations, or limit the Company's ability to execute its business strategies and engage in certain business activities. Certain subsidiaries of the Company are subject to consent orders with the Consumer Financial Protection Bureau ("CFPB") and FDIC, as described below. Pursuant to powers granted under federal banking laws, regulatory agencies have broad and sweeping discretion and may assess civil money penalties, require changes to certain business practices or require customer restitution at any time. In accordance with applicable accounting guidance, the Company establishes a liability for legal and regulatory matters when those matters create loss contingencies that are both probable and estimable. Except as discussed below regarding the card product misclassification matter, other litigation and regulatory settlement-related expenses were immaterial for the three and nine months ended September 30, 2024 and 2023. There may be an exposure to loss in excess of any amounts accrued. The Company believes the estimate of the aggregate range of reasonably possible losses (meaning the likelihood of losses is more than remote but less than likely), in excess of the amounts that the Company has accrued for legal and regulatory proceedings, is up to $70 million as of September 30, 2024. This estimated range of reasonably possible losses is based on currently available information for those proceedings in which the Company is involved and considers the Company's best estimate of such losses for those matters for which an estimate can be made. It does not represent the Company's maximum potential loss exposure. Various aspects of the legal and regulatory proceedings underlying the estimated range will change from time to time and actual results may vary significantly from the estimate. The Company's estimated range noted above involves significant judgment, given the varying stages of the proceedings, the existence of numerous yet to be resolved issues, the breadth of the claims (often spanning multiple years and, in some cases, a wide range of business activities), unspecified damages and/or the novelty of the legal issues presented. The outcome of pending matters could adversely affect the Company's reputation and be material to the Company's condensed consolidated financial condition, operating results and cash flows for a particular future period, depending on, among other things, the level of the Company's income for such period. In July 2015, the Company announced that its subsidiaries, Discover Bank, The Student Loan Corporation and Discover Products Inc. (the "Discover Subsidiaries"), agreed to a consent order with the CFPB with respect to certain private student loan servicing practices (the "2015 Order"). The 2015 Order expired in July 2020. In December 2020, the Discover Subsidiaries agreed to a consent order (the "2020 Order") with the CFPB resolving the agency’s investigation into Discover Bank’s compliance with the 2015 Order. In connection with the 2020 Order, Discover is required to implement a redress and compliance plan and must pay at least $10 million in consumer redress to consumers who may have been harmed and has paid a $25 million civil money penalty to the CFPB. On September 25, 2023, following the consent of the Board of Directors of Discover Bank, the FDIC issued a consent order (the "2023 Order") to Discover Bank. The 2023 Order addresses shortcomings in Discover Bank’s compliance management system for consumer protection laws and related matters. It does not contain any monetary penalties or fines. As part of the 2023 Order, Discover Bank agreed to improve its consumer compliance management system and enhance related corporate governance and enterprise risk management practices, and increase the level of Board oversight of such matters. Discover Bank has been taking significant steps to strengthen the organization’s compliance management system and address the other issues identified in the 2023 Order. In addition, Discover added two new independent directors with significant banking experience to the Boards of Discover and Discover Bank in the third quarter of 2023. Management and the Board are committed to meeting all the requirements of the 2023 Order. Discover Bank is working diligently to complete items required by the 2023 Order. This includes having retained third party consultants to conduct independent reviews and the submission of action plans to the FDIC by the required deadlines for review and feedback. The actions completed to date, taken together with actions previously undertaken to improve and enhance its compliance management system and enhance related corporate governance, address multiple consent order objectives, however, many provisions require longer term implementation. Depending on regulatory feedback, the timing of approvals and sustainability periods, necessary work is not likely to be completed until at least 2025. On March 8, 2016, a class-action lawsuit was filed against the Company, other credit card networks, other issuing banks and EMVCo in the U.S. District Court for the Northern District of California (B&R Supermarket, Inc., d/b/a Milam's Market, et al. v. Visa, Inc., et al.) alleging a conspiracy by defendants to shift fraud liability to merchants with the migration to the EMV security standard and chip technology. The plaintiffs assert joint and several liability among the defendants and seek unspecified damages, including treble damages, attorneys' fees, costs and injunctive relief. On December 6, 2024, Plaintiffs and the Company reached an agreement on the terms of a class wide settlement to resolve the claims against the Company. The parties must now negotiate a formal settlement and that settlement must be approved by the court. Card Product Misclassification As of September 30, 2024, the balance of the Company's counterparty restitution liability was $1.2 billion, reflecting additional accruals for interest on the overcharges committed to as part of the counterparty restitution plan approved by the Board of Directors in the third quarter of 2023, additional concessions agreed to as part of the class action settlement negotiations through the third quarter of 2024 and settlement disbursements made year-to-date. As reported in the Company's Current Report on Form 8-K filed on July 3, 2024, on July 1, 2024, the Company and certain of its subsidiaries entered into a settlement agreement to resolve putative class actions filed on behalf of merchants allegedly affected by the card product misclassification. The settlement agreement, which is subject to court approval, would resolve claims by parties affected by the card product misclassification (merchants, merchant acquirers and other intermediaries). The Company expects all payments under the settlement agreement to be covered by the $1.2 billion liability. Substantially all of the liability represents amounts payable to or on behalf of impacted merchants, merchant acquirers and other intermediaries in settlement of the card product misclassification matter, with $26 million of that balance representing provision for legal fees and expenses payable to plaintiffs' counsel. On August 27, 2024, plaintiffs moved for preliminary approval of the settlement agreement, and on October 22, 2024, the court entered an order granting preliminary approval. The liability does not include any potential regulatory fines or penalties, or the cost of administering the distribution of funds to affected parties. The following table summarizes the change in the Company's counterparty restitution liability pertaining to the card product misclassification (dollars in millions): For the Nine Months Ended September 30, 2024 Balance at December 31, 2023 $ 1,159 Provision for refund of overcharges — Provision for interest on overcharges 42 Provision for other settlement concessions 76 Disbursements (76) Balance at September 30, 2024 $ 1,201 The Company remains in discussions with its various regulators regarding the card product misclassification. For the three months ended June 30, 2024, the Company recognized a separate charge of approximately $200 million representing the Company's current estimate of potential penalties to be imposed by its various regulators in relation to this matter. For the three months ended September 30, 2024, the Company recognized an additional charge of approximately $90 million in respect of such potential penalties. Actual penalties imposed are subject to further discussion with the Company's various regulators and may be more or less than such amount. In addition, the Company and its subsidiaries have been named as defendants in various lawsuits, including a putative class action on behalf of shareholders and a shareholder derivative action. The Company is also cooperating with an SEC investigation into the card product misclassification matter. The Company believes that additional losses are probable as a result of these actions and such losses could be material but it is not able to make a reasonable estimate of the amount or range of such losses as of September 30, 2024.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Accounting Standards Codification ("ASC") Topic 820, Fair Value Measurement , provides a three-level hierarchy for classifying the inputs to valuation techniques used to measure fair value of financial instruments based on whether the inputs are observable or unobservable. It also requires certain disclosures about those measurements. The three-level valuation hierarchy is as follows: • Level 1 : Fair values determined by Level 1 inputs are defined as those that utilize quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access. • Level 2 : Fair values determined by Level 2 inputs are those that utilize inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices for similar assets and liabilities in active or inactive markets, quoted prices for the identical assets in an inactive market and inputs other than quoted prices that are observable for the asset or liability, such as interest rates and yield curves that are observable at commonly quoted intervals. The Company evaluates factors such as the frequency of transactions, the size of the bid-ask spread and the significance of adjustments made when considering transactions involving similar assets or liabilities to assess the relevance of those observed prices. If relevant and observable prices are available, the fair values of the related assets or liabilities would be classified as Level 2. • Level 3 : Fair values determined by Level 3 inputs are those based on unobservable inputs and include situations where there is little, if any, market activity for the asset or liability being valued. In instances where the inputs used to measure fair value may fall into different levels of the fair value hierarchy, the level in the fair value hierarchy in which the measurements are classified is based on the lowest level input that is significant to the fair value measurement in its entirety. Accordingly, the Company may utilize both observable and unobservable inputs in determining the fair values of financial instruments classified within the Level 3 category. The Company evaluates the classification of each fair value measurement within the hierarchy at least quarterly. The Company's assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and involves consideration of factors specific to the asset or liability. Furthermore, certain techniques used to measure fair value involve some degree of judgment and, as a result, are not necessarily indicative of the amounts the Company would realize in a current market exchange. Assets and Liabilities Measured at Fair Value on a Recurring Basis Assets and liabilities measured at fair value on a recurring basis are as follows (dollars in millions): Quoted Price Significant Significant Total Balance at September 30, 2024 Assets Fair value - OCI U.S. Treasury and U.S. GSE securities $ 14,177 $ 8 $ — $ 14,185 Residential mortgage-backed securities - Agency — 405 — 405 Available-for-sale investment securities $ 14,177 $ 413 $ — $ 14,590 Liabilities Fair value - OCI Derivative financial instruments - cash flow hedges (1) $ — $ 18 $ — $ 18 Fair value - Net income Derivative financial instruments - fair value hedges (1) $ — $ 19 $ — $ 19 Balance at December 31, 2023 Assets Fair value - OCI U.S. Treasury and U.S. GSE securities $ 12,928 $ 9 $ — $ 12,937 Residential mortgage-backed securities - Agency — 465 — 465 Available-for-sale investment securities $ 12,928 $ 474 $ — $ 13,402 Derivative financial instruments - cash flow hedges (1) $ — $ 2 $ — $ 2 Fair value - Net income Marketable equity securities $ 1 $ — $ — $ 1 Derivative financial instruments - fair value hedges (1) $ — $ 2 $ — $ 2 . (1) Derivative instrument carrying values in an asset or liability position are presented as part of other assets or accrued expenses and other liabilities, respectively, in the Company's condensed consolidated statements of financial condition. Available-for-Sale Investment Securities Investment securities classified as available-for-sale consist of U.S. Treasury and U.S. GSE securities and RMBS. The fair value estimates of investment securities classified as Level 1, consisting of U.S. Treasury securities, are determined based on quoted market prices for the same securities. The fair value estimates of U.S. GSE securities and RMBS are classified as Level 2 and are valued by maximizing the use of relevant observable inputs, including quoted prices for similar securities, benchmark yield curves and market-corroborated inputs. The Company validates the fair value estimates provided by pricing services primarily by comparing to valuations obtained through other pricing sources. The Company evaluates pricing variances among different pricing sources to ensure that the valuations utilized are reasonable. The Company also corroborates the reasonableness of the fair value estimates with analysis of trends of significant inputs, such as market interest rate curves. The Company further performs due diligence in understanding the procedures and techniques performed by the pricing services to derive fair value estimates. At September 30, 2024, amounts reported in RMBS reflect U.S. government agency and U.S. GSE obligations issued by Ginnie Mae, Fannie Mae and Freddie Mac with an aggregate par value of $412 million, a weighted-average coupon of 4.12% and a weighted-average remaining maturity of four years. Derivative Financial Instruments The Company's derivative financial instruments consist of interest rate swaps and foreign exchange forward contracts. These instruments are classified as Level 2 as their fair values are estimated using proprietary pricing models, containing certain assumptions based on readily observable market-based inputs, including interest rate curves, option volatility and foreign currency forward and spot rates. In determining fair values, the pricing models use widely accepted valuation techniques, including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity and the observable market-based inputs. The fair values of the interest rate swaps are determined using the market standard methodology of netting the discounted future fixed cash receipts (or payments) and the discounted expected variable cash payments (or receipts). The variable cash payments (or receipts) are based on an expectation of future interest rates derived from the observable market interest rate curves. The Company considers collateral and master netting agreements that mitigate credit exposure to counterparties in determining the counterparty credit risk valuation adjustment. The fair values of the foreign exchange forward contracts are valued by comparing the contracted forward exchange rate pertaining to the specific contract maturities to the current market exchange rate. The Company validates the fair value estimates of interest rate swaps primarily through comparison to the fair value estimates computed by the counterparties to each of the derivative transactions. The Company evaluates pricing variances among different pricing sources to ensure that the valuations utilized are reasonable. The Company also corroborates the reasonableness of the fair value estimates with analysis of trends of significant inputs, such as market interest rate curves. The Company performs due diligence in understanding the impact of any changes to the valuation techniques performed by proprietary pricing models before implementation, working closely with the third-party valuation service and reviewing the service's control objectives at least annually. The Company corroborates the fair value of foreign exchange forward contracts through independent calculation of the fair value estimates. Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis The Company also has assets that, under certain conditions, are subject to measurement at fair value on a non-recurring basis. These assets include those associated with acquired businesses, including goodwill. For these assets, measurement at fair value in periods subsequent to the initial recognition of the assets may be applicable whenever one is tested for impairment. No impairments were recognized related to these assets during the three and nine months ended September 30, 2024 and 2023. Financial Instruments Measured at Other Than Fair Value The following tables disclose the estimated fair value of the Company's financial assets and financial liabilities that are not required to be carried at fair value (dollars in millions): Balance at September 30, 2024 Quoted Prices in Active Markets Significant Significant Total Carrying Assets Amortized cost Residential mortgage-backed securities - Agency $ — $ 260 $ — $ 260 $ 275 Held-to-maturity investment securities $ — $ 260 $ — $ 260 $ 275 Net loan receivables (1) $ — $ 8,878 $ 117,553 $ 126,431 $ 118,481 Carrying value approximates fair value (2) Cash and cash equivalents $ 10,787 $ — $ — $ 10,787 $ 10,787 Restricted cash $ 36 $ — $ — $ 36 $ 36 Other short-term investments $ 735 $ — $ — $ 735 $ 735 Accrued interest receivables (3)(4) $ — $ 1,324 $ — $ 1,324 $ 1,309 Liabilities Amortized cost Time deposits (5) $ — $ 46,338 $ — $ 46,338 $ 46,076 Short-term borrowings $ — $ 750 $ — $ 750 $ 750 Long-term borrowings - owed to securitization investors $ — $ 8,448 $ 54 $ 8,502 $ 8,557 Other long-term borrowings — 9,043 — 9,043 8,870 Long-term borrowings $ — $ 17,491 $ 54 $ 17,545 $ 17,427 Carrying value approximates fair value (2) Accrued interest payables (3) $ — $ 396 $ — $ 396 $ 396 Balance at December 31, 2023 Assets Amortized cost Residential mortgage-backed securities - Agency $ — $ 234 $ — $ 234 $ 253 Held-to-maturity investment securities $ — $ 234 $ — $ 234 $ 253 Net loan receivables $ — $ — $ 126,940 $ 126,940 $ 119,126 Carrying value approximates fair value (2) Cash and cash equivalents $ 11,685 $ — $ — $ 11,685 $ 11,685 Restricted cash $ 43 $ — $ — $ 43 $ 43 Accrued interest receivables (3) $ — $ 1,450 $ — $ 1,450 $ 1,450 Liabilities Amortized cost Time deposits (5) $ — $ 45,333 $ — $ 45,333 $ 45,240 Short-term borrowings $ — $ 750 $ — $ 750 $ 750 Long-term borrowings - owed to securitization investors $ — $ 10,770 $ 65 $ 10,835 $ 10,993 Other long-term borrowings — 9,469 — 9,469 9,588 Long-term borrowings $ — $ 20,239 $ 65 $ 20,304 $ 20,581 Carrying value approximates fair value (2) Accrued interest payables (3) $ — $ 421 $ — $ 421 $ 421 (1) Includes $8.9 billion in private student loans held-for-sale valued based on the terms of the executed purchase agreement. The carrying value for loans held-for-sale represents the lower of amortized cost or fair value while the carrying value for the loan portfolio is amortized cost, net of the allowance for credit losses. (2) The carrying values of these assets and liabilities approximate fair value due to their short-term nature, except as otherwise indicated. (3) Accrued interest receivable and payable carrying values are presented as part of other assets and accrued expenses and other liabilities, respectively, in the Company's condensed consolidated statements of financial condition. (4) The fair value includes a premium associated with interest to be capitalized on private student loans held-for-sale based on the terms of the executed purchase agreement. (5) Excludes deposits without contractually defined maturities for all periods presented.

Derivatives and Hedging Activit

Derivatives and Hedging Activities	9 Months Ended
	Sep. 30, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	Derivatives and Hedging Activities The Company uses derivatives to manage its exposure to various financial risks. The Company does not enter into derivatives for trading or speculative purposes. Certain derivatives used to manage the Company's exposure to foreign currency are not designated as hedges and do not qualify for hedge accounting. Derivatives may give rise to counterparty credit risk, which generally is mitigated through collateral arrangements as described under the sub-heading "— Collateral Requirements and Credit-Risk Related Contingency Features." The Company enters into derivative transactions with established dealers that meet minimum credit criteria established by the Company. All counterparties must be pre-approved before engaging in any transaction with the Company. The Company regularly monitors counterparties to ensure compliance with the Company's risk policies and limits. In determining the counterparty credit risk valuation adjustment for the fair values of derivatives, if any, the Company considers collateral and legally enforceable master netting agreements that mitigate credit exposure to related counterparties. All derivatives are recorded in other assets at their gross positive fair values and in accrued expenses and other liabilities at their gross negative fair values. See Note 14: Fair Value Measurements for a description of the valuation methodologies used for derivatives. Cash collateral amounts associated with derivative positions that are cleared through an exchange are legally characterized as settlement of the derivative positions. Such collateral amounts are reflected as offsets to the associated derivatives balances recorded in other assets or in accrued expenses and other liabilities. Other cash collateral posted and held balances are recorded in other assets and deposits, respectively, in the condensed consolidated statements of financial condition. Collateral amounts recorded in the condensed consolidated statements of financial condition are based on the net collateral posted or held position for each applicable legal entity's master netting arrangement with each counterparty. Derivatives Designated as Hedges Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows arising from changes in interest rates, or other types of forecasted transactions, are considered cash flow hedges. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Cash Flow Hedges The Company uses interest rate swaps to manage its exposure to variability in cash flows related to changes in interest rates on interest-earning assets and funding instruments. These interest rate swaps qualify for hedge accounting in accordance with ASC Topic 815, Derivatives and Hedging ("ASC 815"). At September 30, 2024 and December 31, 2023, the Company's outstanding cash flow hedges primarily relate to interest receipts from credit card receivables and had an initial maximum period of five years. The change in the fair value of derivatives designated as cash flow hedges is recorded in OCI and is subsequently reclassified into earnings in the period that the hedged forecasted cash flows affect earnings. Amounts reported in AOCI related to derivatives at September 30, 2024, will be reclassified to interest income and interest expense as interest receipts and payments are accrued on the Company's then outstanding credit card receivables and certain floating-rate debt, respectively. During the next 12 months, the Company estimates it will reclassify $28 million into pretax earnings related to its cash flow hedges. Fair Value Hedges The Company is exposed to changes in the fair value of its fixed-rate debt obligations due to changes in interest rates. The Company uses interest rate swaps to manage its exposure to changes in the fair value of certain fixed-rate long-term borrowings, including securitized debt and bank notes, and deposits attributable to changes in the respective benchmark rates. These interest rate swaps qualify as fair value hedges in accordance with ASC 815. Changes in the fair values of both (i) the derivatives and (ii) the hedged long-term borrowings and deposits attributable to the interest-rate risk being hedged are recorded in interest expense and generally provide substantial offset to one another. Derivatives Not Designated as Hedges Foreign Exchange Forward Contracts The Company has foreign exchange forward contracts that are economic hedges and are not designated as accounting hedges. The Company enters into foreign exchange forward contracts to manage foreign currency risk. Changes in the fair value of these contracts are recorded in other income on the condensed consolidated statements of income. Derivatives Cleared Through an Exchange Cash variation margin payments on derivatives cleared through an exchange are legally considered settlement payments and are accounted for with corresponding derivative positions as one unit of account and not presented separately as collateral. With settlement payments on derivative positions cleared through this exchange reflected as offsets to the associated derivative asset and liability balances, the fair values of derivative instruments and collateral balances shown are generally reduced. Derivatives Activity The following table summarizes the fair value (including accrued interest) and outstanding notional amounts of derivative instruments and related collateral balances (dollars in millions): September 30, 2024 December 31, 2023 Notional Number of Outstanding Derivative Contracts Derivative Assets Derivative Liabilities Notional Derivative Assets Derivative Liabilities Derivatives designated as hedges Interest rate swaps—cash flow hedge $ 15,000 20 $ — $ 18 $ 10,650 $ 2 $ — Interest rate swaps—fair value hedge $ 15,371 19 — 19 $ 8,650 2 — Derivatives not designated as hedges Foreign exchange forward contracts (1) $ 33 6 — — $ 29 — — Total gross derivative assets/liabilities (2) — 37 4 — Less: collateral held/posted (3) — (37) — — Total net derivative assets/liabilities $ — $ — $ 4 $ — (1) The foreign exchange forward contracts have notional amounts of EUR 6 million, GBP 6 million, SGD 1 million and INR 1.5 billion as of September 30, 2024, and notional amounts of EUR 6 million, GBP 6 million, SGD 1 million, INR 1.1 billion and AUD 2 million as of December 31, 2023. (2) In addition to the derivatives disclosed in the table, the Company enters into forward contracts to purchase when-issued mortgage-backed securities and tax exempt single family mortgage revenue bonds as part of its community reinvestment initiatives. At September 30, 2024, the Company had no outstanding contracts. At December 31, 2023, the Company had one outstanding contract with a total notional amount of $35 million and an immaterial fair value. (3) Collateral amounts, which consist of cash and investment securities, are limited to the related derivative asset/liability balance and do not include excess collateral received/pledged. The following amounts were recorded on the statements of financial condition related to cumulative basis adjustments for fair value hedges (dollars in millions): September 30, 2024 December 31, 2023 Carrying Amount of Hedged Liabilities Cumulative Amount of Fair Value Hedging Adjustment Increasing the Carrying Amount of Hedged Liabilities (1) Carrying Amount of Hedged Liabilities Cumulative Amount of Fair Value Hedging Adjustment Increasing/(Decreasing) the Carrying Amount of Hedged Liabilities (1) Long-term borrowings $ 15,490 $ 162 $ 8,620 $ — (1) The balance includes $6 million and $12 million of cumulative hedging adjustments related to discontinued hedging relationships as of September 30, 2024 and December 31, 2023, respectively. The following table summarizes the impact of the derivative instruments on income and indicates where within the condensed consolidated financial statements such impact is reported (dollars in millions): Location and Amount of (Losses) Gains Recognized on the Condensed Consolidated Statements of Income Interest Expense Interest Income (Credit Card) Other Expense Deposits Long-Term Borrowings For the Three Months Ended September 30, 2024 Total amounts of income and expense line items presented in the condensed consolidated statements of income, where the effects of fair value or cash flow hedges are recorded $ (1,213) $ (236) $ 4,092 $ (277) The effects of cash flow and fair value hedging Gains (losses) on cash flow hedging relationships Amounts reclassified from OCI into earnings $ — $ 4 $ (48) $ — Gains on discontinued cash flow hedging relationships Amounts reclassified from OCI into earnings $ — $ — $ — $ 13 (Losses) gains on fair value hedging relationships Losses on hedged items $ (90) $ (187) $ — $ — Gains on interest rate swaps 81 145 — — Total losses on fair value hedging relationships $ (9) $ (42) $ — $ — For the Three Months Ended September 30, 2023 Total amounts of income and expense line items presented in the condensed consolidated statements of income, where the effects of fair value or cash flow hedges are recorded $ (1,061) $ (225) $ 3,726 $ (254) The effects of cash flow and fair value hedging Gains (losses) on cash flow hedging relationships Amounts reclassified from OCI into earnings $ — $ 2 $ (31) $ — Gains (losses) on fair value hedging relationships Gains on hedged items $ — $ 24 $ — $ — Losses on interest rate swaps — (53) — — Total losses on fair value hedging relationships $ — $ (29) $ — $ — Location and Amount of (Losses) Gains Recognized on the Condensed Consolidated Statements of Income Interest Expense Interest Income (Credit Card) Other Expense Deposits Long-Term Borrowings For the Nine Months Ended September 30, 2024 Total amounts of income and expense line items presented in the condensed consolidated statements of income, where the effects of fair value or cash flow hedges are recorded $ (3,622) $ (729) $ 11,989 $ (761) The effects of cash flow and fair value hedging Gains (losses) on cash flow hedging relationships Amounts reclassified from OCI into earnings $ — $ 9 $ (134) $ — Gains on discontinued cash flow hedging relationships Amounts reclassified from OCI into earnings $ — $ — $ — $ 13 (Losses) gains on fair value hedging relationships Losses on hedged items $ (91) $ (76) $ — $ — Gains (losses) on interest rate swaps 75 (40) — — Total losses on fair value hedging relationships $ (16) $ (116) $ — $ — For the Nine Months Ended September 30, 2023 Total amounts of income and expense line items presented in the condensed consolidated statements of income, where the effects of fair value or cash flow hedges are recorded $ (2,722) $ (622) $ 10,513 $ (540) The effects of cash flow and fair value hedging Gains (losses) on cash flow hedging relationships Amounts reclassified from OCI into earnings $ — $ 6 $ (56) $ — Gains (losses) on fair value hedging relationships Gains on hedged items $ — $ 111 $ — $ — Losses on interest rate swaps — (181) — — Total losses on fair value hedging relationships $ — $ (70) $ — $ — For the impact of the derivative instruments on OCI, see Note 8: Accumulated Other Comprehensive Income. Collateral Requirements and Credit-Risk Related Contingency Features The Company has master netting arrangements and minimum collateral posting thresholds with its counterparties for its fair value and cash flow hedge interest rate swaps and foreign exchange forward contracts. The Company has not sought a legal opinion in relation to the enforceability of its master netting arrangements and, as such, does not report any of these positions on a net basis. Collateral is required by either the Company or its subsidiaries or the counterparty depending on the net fair value position of the derivatives held with that counterparty. These collateral receivable or payable amounts are generally not offset against the fair value of these derivatives but are recorded separately in other assets or deposits. Most of the Company's cash collateral amounts relate to positions cleared through an exchange and are reflected as offsets to the associated derivatives balances recorded in other assets and accrued expenses and other liabilities. The Company also has agreements with certain of its derivative counterparties that contain a provision under which the Company could be declared in default on any of its derivative obligations if the Company defaults on any of its indebtedness, including default where the lender has not accelerated repayment of the indebtedness.

Segment Disclosures

Segment Disclosures	9 Months Ended
	Sep. 30, 2024
Segment Reporting [Abstract]
Segment Disclosures	Segment Disclosures The Company manages its business activities in two segments: Digital Banking and Payment Services. • Digital Banking: The Digital Banking segment includes Discover-branded credit cards issued to individuals on the Discover Network and other consumer products and services, including private student loans, personal loans, home loans and deposit products. The majority of Digital Banking revenues relate to interest income earned on the segment's loan products. Additionally, the Company's credit card products generate substantially all revenues related to discount and interchange, protection products and loan fee income. • Payment Services: The Payment Services segment includes PULSE, an ATM, debit and electronic funds transfer network; Diners Club, a global payments network; and the Company's Network Partners business, which provides payment transaction processing and settlement services on the Discover Network. The majority of Payment Services revenues relate to transaction processing revenue from PULSE and royalty and licensee revenue from Diners Club. The business segment reporting provided to and used by the Company's CODM is prepared using the following principles and allocation conventions: • The Company aggregates operating segments when determining reportable segments. • Corporate overhead is not allocated between segments; all corporate overhead is included in the Digital Banking segment. • Through its operation of the Discover Network, the Digital Banking segment incurs fixed marketing, servicing and infrastructure costs that are not specifically allocated among the segments, except for an allocation of direct and incremental costs driven by the Company's Payment Services segment. • The Company's assets are not allocated among the operating segments in the information reviewed by the Company's CODM. • The revenues of each segment are derived from external sources. The segments do not earn revenue from intercompany sources. • Income taxes are not specifically allocated between the operating segments in the information reviewed by the Company's CODM. The following table presents segment data (dollars in millions): Digital Payment Total For the Three Months Ended September 30, 2024 Interest income Credit card loans $ 4,092 $ — $ 4,092 Private student loans 244 — 244 Personal loans 360 — 360 Other loans 138 — 138 Other interest income 278 — 278 Total interest income 5,112 — 5,112 Interest expense 1,457 — 1,457 Net interest income 3,655 — 3,655 Provision for credit losses 1,473 — 1,473 Other income 669 129 798 Other expense 1,743 45 1,788 Income before income taxes $ 1,108 $ 84 $ 1,192 For the Three Months Ended September 30, 2023 (As Restated) Interest income Credit card loans $ 3,726 $ — $ 3,726 Private student loans 261 — 261 Personal loans 305 — 305 Other loans 87 — 87 Other interest income 231 — 231 Total interest income 4,610 — 4,610 Interest expense 1,288 — 1,288 Net interest income 3,322 — 3,322 Provision for credit losses 1,702 — 1,702 Other income 575 130 705 Other expense 1,519 45 1,564 Income before income taxes $ 676 $ 85 $ 761 Digital Payment Total For the Nine Months Ended September 30, 2024 Interest income Credit card loans $ 11,989 $ — $ 11,989 Private student loans 764 — 764 Personal loans 1,040 — 1,040 Other loans 379 — 379 Other interest income 859 — 859 Total interest income 15,031 — 15,031 Interest expense 4,365 — 4,365 Net interest income 10,666 — 10,666 Provision for credit losses 3,709 — 3,709 Other income 1,901 584 2,485 Other expense 4,929 141 5,070 Income before income taxes $ 3,929 $ 443 $ 4,372 For the Nine Months Ended September 30, 2023 (As Restated) Interest income Credit card loans $ 10,513 $ — $ 10,513 Private student loans 768 — 768 Personal loans 831 — 831 Other loans 224 — 224 Other interest income 641 — 641 Total interest income 12,977 — 12,977 Interest expense 3,346 — 3,346 Net interest income 9,631 — 9,631 Provision for credit losses 4,109 — 4,109 Other income 1,650 333 1,983 Other expense 4,220 131 4,351 Income before income taxes $ 2,952 $ 202 $ 3,154

Revenue from Contracts with Cus

Revenue from Contracts with Customers	9 Months Ended
	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Revenue from Contracts with Customers ASC Topic 606, Revenue from Contracts with Customers ("ASC 606"), generally applies to the sales of any good or service for which no other specific accounting guidance is provided. ASC 606 defines a principles-based model under which revenue from a contract is allocated to the distinct performance obligations within the contract and recognized in income as each performance obligation is satisfied. The Company's revenue that is subject to this model includes discount and interchange, protection products fees, transaction processing revenue and certain amounts classified as other income. The following table presents revenue from contracts with customers disaggregated by business segment and reconciles revenue from contracts with customers to total other income (dollars in millions): Digital Banking Payment Services Total For the Three Months Ended September 30, 2024 Other income subject to ASC 606 Discount and interchange revenue, net (1) $ 337 $ 26 $ 363 Protection products revenue 42 — 42 Transaction processing revenue — 84 84 Other income 76 19 95 Total other income subject to ASC 606 (2) 455 129 584 Other income not subject to ASC 606 Loan fee income 214 — 214 Total other income not subject to ASC 606 214 — 214 Total other income by operating segment $ 669 $ 129 $ 798 For the Three Months Ended September 30, 2023 (As Restated) Other income subject to ASC 606 Discount and interchange revenue, net (1) $ 337 $ 23 $ 360 Protection products revenue 42 — 42 Transaction processing revenue — 82 82 Other income 2 19 21 Total other income subject to ASC 606 (2) 381 124 505 Other income not subject to ASC 606 Loan fee income 194 — 194 Other income — 6 6 Total other income not subject to ASC 606 194 6 200 Total other income by operating segment $ 575 $ 130 $ 705 Digital Banking Payment Services Total For the Nine Months Ended September 30, 2024 Other income subject to ASC 606 Discount and interchange revenue, net (1) $ 1,044 $ 77 $ 1,121 Protection products revenue 126 — 126 Transaction processing revenue — 262 262 Other income 112 245 357 Total other income subject to ASC 606 (2) 1,282 584 1,866 Other income not subject to ASC 606 Loan fee income 619 — 619 Total other income not subject to ASC 606 619 — 619 Total other income by operating segment $ 1,901 $ 584 $ 2,485 For the Nine Months Ended September 30, 2023 (As Restated) Other income subject to ASC 606 Discount and interchange revenue, net (1) $ 963 $ 64 $ 1,027 Protection products revenue 129 — 129 Transaction processing revenue — 221 221 Other income 12 59 71 Total other income subject to ASC 606 (2) 1,104 344 1,448 Other income not subject to ASC 606 Loan fee income 546 — 546 Other income (loss) — (11) (11) Total other income (loss) not subject to ASC 606 546 (11) 535 Total other income by operating segment $ 1,650 $ 333 $ 1,983 (1) Net of rewards, including Cashback Bonus rewards, of $779 million and $787 million for the three months ended September 30, 2024 and 2023, respectively, and $2.2 billion and $2.3 billion for the nine months ended September 30, 2024 and 2023 , respectively. (2) Excludes $2 million and $3 million of deposit product fees that are reported within net interest income for the three months ended September 30, 2024 and 2023, respectively, and $6 million and $13 million for the nine months ended September 30, 2024 and 2023, respectively. For a detailed description of the Company's significant revenue recognition accounting policies, see Note 2: Summary of Significant Accounting Policies to the consolidated financial statements in the Company's annual report on Form 10-K/A for the year ended December 31, 2023.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2024
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company has evaluated events and transactions that have occurred subsequent to September 30, 2024, and determined that there were no subsequent events that would require recognition or additional disclosure in the condensed consolidated financial statements.

Background and Basis of Prese_2

Background and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of presentation	The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. ("GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. In the opinion of management, the financial statements reflect all adjustments necessary for the fair presentation of results for the interim period. All such adjustments are of a normal, recurring nature.
Use of estimates	The preparation of financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and related disclosures. These estimates are based on information available as of the date of the condensed consolidated financial statements. The Company believes that the estimates used in the preparation of the condensed consolidated financial statements are reasonable. Actual results could differ from these estimates.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Schedule of Investment Securities	The Company's investment securities consist of the following (dollars in millions): September 30, December 31, U.S. Treasury bills (1) $ 735 $ — Total other short-term investments $ 735 $ — U.S. Treasury (2) and U.S. GSE (3) securities $ 14,185 $ 12,937 Residential mortgage-backed securities - Agency (4) 680 718 Total investment securities $ 14,865 $ 13,655 (1) Includes U.S. Treasury bills with maturity dates greater than 90 days but less than one year at the time of acquisition. (2) Includes $407 million and $320 million of U.S. Treasury securities pledged as swap collateral as of September 30, 2024 and December 31, 2023, respectively. (3) Consists of securities issued by the Federal Home Loan Bank ("FHLB"). (4) Primarily consists of securities issued by Fannie Mae, Freddie Mac, or Ginnie Mae.
Schedule of Amortized Cost, Gross Unrealized Gains, Gross Unrealized Losses and Fair Value	The amortized cost, gross unrealized gains and losses and fair value of available-for-sale and held-to-maturity investment securities are as follows (dollars in millions): Amortized Gross Gross Fair Value At September 30, 2024 Available-for-Sale Investment Securities (1) U.S. Treasury and U.S. GSE securities $ 14,058 $ 146 $ (19) $ 14,185 Residential mortgage-backed securities - Agency 412 — (7) 405 Total available-for-sale investment securities $ 14,470 $ 146 $ (26) $ 14,590 Held-to-Maturity Investment Securities (2) Residential mortgage-backed securities - Agency (3) $ 275 $ 2 $ (17) $ 260 Total held-to-maturity investment securities $ 275 $ 2 $ (17) $ 260 At December 31, 2023 Available-for-Sale Investment Securities (1) U.S. Treasury and U.S. GSE securities $ 12,971 $ 52 $ (86) $ 12,937 Residential mortgage-backed securities - Agency 480 — (15) 465 Total available-for-sale investment securities $ 13,451 $ 52 $ (101) $ 13,402 Held-to-Maturity Investment Securities (2) Residential mortgage-backed securities - Agency (3) $ 253 $ — $ (19) $ 234 Total held-to-maturity investment securities $ 253 $ — $ (19) $ 234 (1) Available-for-sale investment securities are reported at fair value. (2) Held-to-maturity investment securities are reported at amortized cost. (3) Amounts represent residential mortgage-backed securities ("RMBS") that were classified as held-to-maturity as they were entered into as a part of the Company's community reinvestment initiatives.
Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value	The following table provides information about available-for-sale investment securities with aggregate gross unrealized losses and the length of time that individual investment securities have been in a continuous unrealized loss position (dollars in millions): Number of Securities in a Loss Position Less than 12 months More than 12 months Fair Unrealized Fair Unrealized At September 30, 2024 Available-for-Sale Investment Securities U.S. Treasury and U.S. GSE securities 31 $ 1,137 $ (2) $ 2,593 $ (17) Residential mortgage-backed securities - Agency 30 $ — $ — $ 405 $ (7) At December 31, 2023 Available-for-Sale Investment Securities U.S. Treasury and U.S. GSE securities 105 $ 3,513 $ (13) $ 3,978 $ (73) Residential mortgage-backed securities - Agency 31 $ — $ — $ 465 $ (15)
Schedule of Maturities of Available-for-Sale Debt Securities and Held-to-Maturity Debt Securities	Maturities of available-for-sale debt securities and held-to-maturity debt securities are provided in the following table (dollars in millions): At September 30, 2024 One Year After One After Five After Ten Total Available-for-Sale Investment Securities — Amortized Cost U.S. Treasury and U.S. GSE securities $ 2,193 $ 11,792 $ 73 $ — $ 14,058 Residential mortgage-backed securities - Agency (1) — 52 106 254 412 Total available-for-sale investment securities $ 2,193 $ 11,844 $ 179 $ 254 $ 14,470 Held-to-Maturity Investment Securities — Amortized Cost Residential mortgage-backed securities - Agency (1) $ — $ — $ — $ 275 $ 275 Total held-to-maturity investment securities $ — $ — $ — $ 275 $ 275 Available-for-Sale Investment Securities — Fair Values U.S. Treasury and U.S. GSE securities $ 2,183 $ 11,926 $ 76 $ — $ 14,185 Residential mortgage-backed securities - Agency (1) — 50 105 250 405 Total available-for-sale investment securities $ 2,183 $ 11,976 $ 181 $ 250 $ 14,590 Held-to-Maturity Investment Securities — Fair Values Residential mortgage-backed securities - Agency (1) $ — $ — $ — $ 260 $ 260 Total held-to-maturity investment securities $ — $ — $ — $ 260 $ 260 (1) Maturities of RMBS are reflective of the contractual maturities of the investment.

Loan Receivables (Tables)

Loan Receivables (Tables)	9 Months Ended
	Sep. 30, 2024
Receivables [Abstract]
Schedule of Loan Receivables	The Company's classes of receivables within the two portfolio segments are depicted in the following table (dollars in millions): September 30, December 31, Loans held-for-sale (1)(2) $ 8,484 $ — Loan portfolio Credit card loans (3)(4) 100,489 102,259 Other loans (1) Private student loans (2) — 10,352 Personal loans 10,438 9,852 Other loans 7,582 5,946 Total other loans 18,020 26,150 Total loan portfolio 118,509 128,409 Total loan receivables 126,993 128,409 Allowance for credit losses (8,512) (9,283) Net loan receivables $ 118,481 $ 119,126 (1) Accrued interest receivable on private student, personal and other loans, which is presented as part of other assets in the Company's condensed consolidated statements of financial condition, was $372 million, $74 million and $28 million, respectively, at September 30, 2024 and $522 million, $69 million and $21 million, respectively, at December 31, 2023. (2) At September 30, 2024, the private student loan portfolio was classified as held-for-sale and there were $6.0 billion of private student loans in repayment. At December 31, 2023, the private student loan portfolio was classified as held-for-investment and there were $6.3 billion of private student loans in repayment. (3) Amounts include carrying values of $11.7 billion and $14.8 billion underlying investors' interest in trust debt at September 30, 2024 and December 31, 2023, respectively, and $16.9 billion and $15.6 billion in seller's interest at September 30, 2024 and December 31, 2023, respectively. See Note 4: Credit Card and Private Student Loan Securitization Activities for additional information. (4) Unbilled accrued interest receivable on credit card loans, which is presented as part of other assets in the Company's condensed consolidated statements of financial condition, was $726 million and $753 million at September 30, 2024 and December 31, 2023, respectively.
Schedule of Credit Risk Profile by FICO Score and Origination Year	The following table provides the distribution of the amortized cost basis (excluding accrued interest receivable presented in other assets) by the most recent FICO scores available for the Company's customers for credit card and personal loan receivables (dollars in millions): Credit Risk Profile by FICO Score September 30, 2024 December 31, 2023 660 and Above Less than 660 660 and Above Less than 660 $ % $ % $ % $ % Credit card loans $ 80,277 80 % $ 20,212 20 % $ 82,238 80 % $ 20,021 20 % Personal loans by origination year 2024 $ 3,915 99 % $ 37 1 % 2023 3,533 95 % 192 5 % $ 5,149 98 % $ 100 2 % 2022 1,623 91 % 169 9 % 2,604 93 % 187 7 % 2021 588 90 % 67 10 % 1,049 92 % 91 8 % 2020 177 91 % 17 9 % 355 92 % 29 8 % Prior 100 83 % 20 17 % 247 86 % 41 14 % Total personal loans $ 9,936 95 % $ 502 5 % $ 9,404 95 % $ 448 5 %
Schedule of Delinquent Loans by Origination Year	The amortized cost basis (excluding accrued interest receivable presented in other assets) of delinquent loans in the Company's loan portfolio is shown below for credit card and personal loan receivables (dollars in millions): September 30, 2024 December 31, 2023 30-89 Days 90 or Total Past 30-89 Days 90 or Total Past Credit card loans $ 1,974 $ 1,883 $ 3,857 $ 2,038 $ 1,917 $ 3,955 Personal loans by origination year 2024 $ 13 $ 3 $ 16 2023 55 19 74 $ 26 $ 8 $ 34 2022 38 15 53 44 16 60 2021 14 6 20 20 8 28 2020 4 1 5 7 2 9 Prior 3 3 6 7 5 12 Total personal loans $ 127 $ 47 $ 174 $ 104 $ 39 $ 143
Schedule of Changes in the Allowance for Credit Losses	The following tables provide changes in the Company's allowance for credit losses (dollars in millions): For the Three Months Ended September 30, 2024 Credit Card Loans Private Student Loans Personal Loans Other Loans Total Loans Balance at June 30, 2024 $ 7,591 $ — $ 793 $ 97 $ 8,481 Additions Provision for credit losses (1) 1,327 — 111 35 1,473 Deductions Charge-offs (1,629) — (123) (4) (1,756) Recoveries 297 — 17 — 314 Net charge-offs (1,332) — (106) (4) (1,442) Balance at September 30, 2024 $ 7,586 $ — $ 798 $ 128 $ 8,512 For the Three Months Ended September 30, 2023 Credit Card Loans Private Student Loans Personal Loans Other Loans Total Loans Balance at June 30, 2023 $ 6,525 $ 849 $ 622 $ 68 $ 8,064 Additions Provision for credit losses (1) 1,518 52 93 8 1,671 Deductions Charge-offs (1,171) (40) (76) — (1,287) Recoveries 198 5 14 — 217 Net charge-offs (973) (35) (62) — (1,070) Balance at September 30, 2023 $ 7,070 $ 866 $ 653 $ 76 $ 8,665 For the Nine Months Ended September 30, 2024 Credit Card Loans Private Student Loans Personal Loans Other Loans Total Loans Balance at December 31, 2023 $ 7,619 $ 858 $ 722 $ 84 $ 9,283 Additions Provision for credit losses (1)(2) 4,083 (770) 383 53 3,749 Deductions Charge-offs (4,926) (100) (353) (9) (5,388) Recoveries 810 12 46 — 868 Net charge-offs (4,116) (88) (307) (9) (4,520) Balance at September 30, 2024 $ 7,586 $ — $ 798 $ 128 $ 8,512 For the Nine Months Ended September 30, 2023 Credit Card Loans Private Student Loans Personal Loans Other Loans Total Loans Balance at December 31, 2022 $ 5,883 $ 839 $ 595 $ 57 $ 7,374 Cumulative effect of ASU No. 2022-02 adoption (3) (66) — (2) — (68) Balance at January 1, 2023 5,817 839 593 57 7,306 Additions Provision for credit losses (1) 3,752 121 211 19 4,103 Deductions Charge-offs (3,101) (111) (194) — (3,406) Recoveries 602 17 43 — 662 Net charge-offs (2,499) (94) (151) — (2,744) Balance at September 30, 2023 $ 7,070 $ 866 $ 653 $ 76 $ 8,665 (1) Excludes a $31 million adjustment of the liability for expected credit losses on unfunded commitments for the three months ended September 30, 2023, and $40 million and $6 million for the nine months ended September 30, 2024 and 2023, respectively, as the liability is recorded in accrued expenses and other liabilities in the Company's condensed consolidated statements of financial condition. With the transfer of private student loans to the held-for-sale classification as of June 30, 2024, a liability for expected credit losses on unfunded commitments is no longer recorded. (2) Includes the adjustment to eliminate the allowance for credit losses upon classifying the private student loan portfolio as held-for-sale. (3) Represents the adjustment to the allowance for credit losses as a result of the adoption of ASU No. 2022-02 on January 1, 2023, which eliminated the requirement to apply discounted cash flow measurements for certain troubled debt restructurings.
Schedule of Net Charge-offs of Interest and Fee Revenues on Loan Receivables	Net charge-offs of principal are recorded against the allowance for credit losses, as shown in the preceding table. Information regarding net charge-offs of interest and fee revenues on credit card and other loans is as follows (dollars in millions): (1) For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 Interest and fees accrued subsequently charged-off, net of recoveries (recorded as a reduction of interest income) $ 274 $ 176 $ 831 $ 460 Fees accrued subsequently charged-off, net of recoveries (recorded as a reduction to other income) $ 61 $ 47 $ 196 $ 134 (1) Amounts presented in this table include charge-offs related to private student loans through June 30, 2024, the date those loans were transferred to held-for-sale classification .
Schedule of Gross Charge Offs from Loan Receivables	Gross principal charge-offs of the Company's loan portfolio are presented in the table below, on a year-to-date basis, for credit card and personal loan receivables (dollars in millions): For the Nine Months Ended September 30, 2024 2023 Credit card loans $ 4,926 $ 3,101 Personal loans by origination year 2024 $ 6 2023 125 $ 5 2022 132 74 2021 56 58 2020 18 26 Prior 16 31 Total personal loans $ 353 $ 194
Schedule of Delinquent and Non-Accruing Loans	The amortized cost basis (excluding accrued interest receivable presented in other assets) of delinquent and non-accruing loans in the Company's loan portfolio, which excludes loans held-for-sale, is shown below for each class of loan receivables (dollars in millions): (1) 30-89 Days 90 or Total Past 90 or Total Non-accruing (2) At September 30, 2024 Credit card loans $ 1,974 $ 1,883 $ 3,857 $ 1,845 $ 191 Other loans Personal loans 127 47 174 45 12 Other loans 44 30 74 5 79 Total other loans 171 77 248 50 91 Total loan portfolio $ 2,145 $ 1,960 $ 4,105 $ 1,895 $ 282 At December 31, 2023 Credit card loans $ 2,038 $ 1,917 $ 3,955 $ 1,881 $ 197 Other loans Personal loans 104 39 143 37 11 Other loans 39 19 58 3 53 Total other loans 143 58 201 40 64 Total loan portfolio $ 2,181 $ 1,975 $ 4,156 $ 1,921 $ 261 (1) The payment status of both modified and unmodified loans is included in this table. (2) The Company estimates that the gross interest income that would have been recorded under the original terms of non-accruing credit card loans was $9 million and $11 million for the three months ended September 30, 2024 and 2023, respectively, and $26 million and $29 million for the nine months ended September 30, 2024 and 2023, respectively. The Company does not separately track the amount of gross interest income that would have been recorded under the original terms of loans. Instead, the Company estimated this amount based on customers' current balances and most recent interest rates.
Schedule of Financing Receivables in Modification , Amortized Cost Basis	The following table provides the period-end amortized cost basis, by modification category, of loans to borrowers experiencing financial difficulty that entered a modification program during the period (dollars in millions). Some of the loans presented in the table below may no longer be enrolled in a program at period-end: For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 Credit card loans (1)(2) Interest rate reduction $ 1,028 $ 685 $ 2,619 $ 1,712 Total credit card loans (3) $ 1,028 $ 685 $ 2,619 $ 1,712 % of total class of financing receivables 1.02 % 0.70 % 2.61 % 1.76 % Personal loans (1) Payment delay (4) $ 5 $ 4 $ 11 $ 8 Term extension (5) 11 9 30 24 Interest rate reduction and payment delay (4) 31 21 75 48 Interest rate reduction and term extension (5) 12 9 34 22 Total personal loans $ 59 $ 43 $ 150 $ 102 % of total class of financing receivables 0.57 % 0.45 % 1.44 % 1.07 % (1) Accrued interest receivable (including unbilled accrued interest receivable for credit card loans) on modified loans to borrowers experiencing financial difficulty, which is presented as part of other assets in the Company's condensed consolidated statements of financial condition, was immaterial at September 30, 2024 and 2023. (2) Accounts that entered a credit card loan modification program include $191 million and $487 million that were converted from revolving line-of-credit arrangements to term loans during the three and nine months ended September 30, 2024, respectively. Accounts that entered a credit card loan modification program include $120 million and $302 million that were converted from revolving line-of-credit arrangements to term loans during the three and nine months ended September 30, 2023, respectively. (3) For settlements, the amortized cost basis is zero at period-end and therefore there is no amount reported for principal forgiveness in the table above. See financial effects table below for principal forgiveness to borrowers experiencing financial difficulty. (4) The Company defines a payment delay as a temporary reduction in payments below the original contractually required payment amounts (e.g., interest only payments). The Company's credit card loan modification programs do not result in an other than insignificant delay in payment.
Schedule of Loan Modification Effects	The following table provides information on the financial effects of loan modifications to borrowers experiencing financial difficulty, by modification type, made during the period (dollars in millions): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 Credit card loans Weighted-average interest rate reduction 14.47 % 13.84 % 14.45 % 13.68 % Principal forgiven $ 62 $ 35 $ 166 $ 81 Interest and fees forgiven (1) $ 58 $ 30 $ 160 $ 77 Personal loans Weighted-average interest rate reduction 14.01 % 12.30 % 13.62 % 12.01 % Weighted-average term extension (in months) 39 38 40 38 Payment delay duration (in months) (2) 6 to 12 6 to 12 6 to 12 6 to 12 (1) Represents the amount of interest and fees forgiven resulting from accounts entering into a credit card loan modification program and pre-charge off settlements. Interest and fees forgiven are reversed against the respective line items in the condensed consolidated statements of income. (2) For personal loan payment delays, the Company limits this assistance to a life of loan maximum of 12 months.
Schedule of Financing Receivable, Past Due, Modified	The following table presents the payment status and period-end amortized cost basis, by class of loan receivable, of loans that were modified to borrowers experiencing financial difficulty during the 12 months preceding each of the periods presented (dollars in millions): (1) Current 30-89 Days 90 or At September 30, 2024 Credit card loans $ 2,677 $ 293 $ 222 Personal loans 147 29 6 Total $ 2,824 $ 322 $ 228 At December 31, 2023 Credit card loans $ 1,882 $ 252 $ 196 Personal loans 109 20 4 Total $ 1,991 $ 272 $ 200 (1) This table includes any loan that entered a modification program during the preceding 12 months without regard to whether it remained in a modification program as of the reporting date.
Schedule of Financing Receivable, Modified, Subsequent Default	The following table presents the defaulted amount and period-end amortized cost basis, by modification category, of loans that defaulted during the period and were modified to borrowers experiencing financial difficulty during the 12 months preceding default (dollars in millions): For the Three Months Ended September 30, 2024 For the Nine Months Ended September 30, 2024 Defaulted Amount (1) Period-end Amortized Cost Basis Defaulted Amount (1) Period-end Amortized Cost Basis Credit card loans Interest rate reduction $ 263 $ 186 $ 658 $ 349 Total credit card loans $ 263 $ 186 $ 658 $ 349 Personal loans Payment delay $ 1 $ 1 $ 2 $ 1 Term extension 2 2 6 3 Interest rate reduction and payment delay 9 3 23 6 Interest rate reduction and term extension 6 5 15 7 Total personal loans $ 18 $ 11 $ 46 $ 17 For the Three Months Ended September 30, 2023 For the Nine Months Ended September 30, 2023 Defaulted Amount (1) Period-end Amortized Cost Basis Defaulted Amount (1) Period-end Amortized Cost Basis Credit card loans Interest rate reduction $ 120 $ 96 $ 203 $ 124 Total credit card loans $ 120 $ 96 $ 203 $ 124 Personal loans Payment delay $ — $ — $ 1 $ 1 Term extension 1 1 2 2 Interest rate reduction and payment delay 3 3 4 4 Interest rate reduction and term extension 3 3 3 3 Total personal loans $ 7 $ 7 $ 10 $ 10 (1) For purposes of this disclosure, a loan is considered to be defaulted when it is 60 days or more delinquent at month end and has advanced two stages of delinquency subsequent to modification. Loans that entered a modification program in any stage of delinquency but did not experience a further payment default are included in the payment status table above but are not counted as defaulted for purposes of this disclosure.

Credit Card and Private Stude_2

Credit Card and Private Student Loan Securitization Activities (Tables)	9 Months Ended
	Sep. 30, 2024
Variable Interest Entities Disclosure [Abstract]
Schedule of Restricted Credit Card Securitized Assets	The carrying values of these restricted assets, which are presented on the Company's condensed consolidated statements of financial condition as relating to securitization activities, are shown in the following table (dollars in millions): September 30, December 31, Restricted cash $ 29 $ 36 Investors' interests held by third-party investors 9,250 11,725 Investors' interests held by wholly-owned subsidiaries of Discover Bank 2,459 3,117 Seller's interest 16,934 15,598 Loan receivables (1) 28,643 30,440 Allowance for credit losses allocated to securitized loan receivables (1) (1,334) (1,347) Net loan receivables 27,309 29,093 Other assets 3 2 Carrying value of assets of consolidated variable interest entities $ 27,341 $ 29,131 (1) The Company maintains its allowance for credit losses at an amount equal to lifetime expected credit losses associated with all loan receivables, which includes all loan receivables in the trusts. Therefore, the credit risk associated with the transferred receivables is fully reflected on the Company's statements of financial condition in accordance with GAAP.

Deposits (Tables)

Deposits (Tables)	9 Months Ended
	Sep. 30, 2024
Deposits [Abstract]
Schedule of Certificates of Deposit Maturities	The following table summarizes certificates of deposits maturing over the remainder of this year, over each of the next four years and thereafter (dollars in millions): At September 30, 2024 2024 $ 10,208 2025 23,052 2026 4,914 2027 4,521 2028 2,209 Thereafter 1,172 Total $ 46,076

Long-Term Borrowings (Tables)

Long-Term Borrowings (Tables)	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Schedule of Long-Term Borrowings and Weighted Average Interest Rates	Long-term borrowings consist of borrowings having original maturities of one year or more. The following table provides a summary of the Company's long-term borrowings and weighted-average interest rates on outstanding balances (dollars in millions): September 30, 2024 December 31, 2023 Maturity Interest Weighted-Average Interest Rate Outstanding Amount Outstanding Amount Securitized Debt Fixed-rate asset-backed securities (1) 2025-2026 1.03% - 5.03% 3.55% $ 8,503 $ 10,003 Floating-rate asset-backed securities 2024 — — — 925 Total Discover Card Master Trust I and Discover Card Execution Note Trust 8,503 10,928 Floating-rate asset-backed security (2)(3) 2031 9.00% 9.00% 54 65 Total private student loan securitization trust 54 65 Total long-term borrowings - owed to securitization investors 8,557 10,993 Discover Financial Services (Parent Company) Fixed-rate senior notes 2024-2032 3.75% - 6.70% 4.68% 3,339 3,336 Fixed-rate retail notes 2025-2031 3.25% - 4.40% 3.82% 138 140 Fixed to floating-rate senior notes (4) 2034 7.96% 7.96% 993 993 Discover Bank Fixed-rate senior bank notes (1) 2026-2030 2.70% - 4.65% 3.82% 2,846 3,571 Fixed-rate subordinated bank notes 2028 5.97% 5.97% 506 500 Fixed-rate Federal Home Loan Bank advances 2030 4.77% - 4.82% 4.82% 523 523 Floating-rate Federal Home Loan Bank advances (5) 2024 4.99% - 5.09% 5.09% 525 525 Total long-term borrowings $ 17,427 $ 20,581 (1) The Company uses interest rate swaps to hedge portions of these long-term borrowings against changes in fair value attributable to changes in the applicable benchmark interest rates. The use of these interest rate swaps impacts the carrying value of the debt. See Note 15: Derivatives and Hedging Activities. (2) The private student loan securitization trust floating-rate asset-backed security includes an issuance with the following interest rate term: Prime rate + 100 basis points as of September 30, 2024. (3) Repayment of this debt is dependent upon the timing of principal and interest payments on the underlying private student loans. The date shown represents the final maturity date. (4) The fixed to floating-rate senior notes include a rate reset on November 2, 2033, to a floating rate based on compounded SOFR + 3.370%. (5) The floating-rate FHLB advances include interest rate terms based on SOFR plus a spread ranging from 16 to 26 basis points as of September 30, 2024.
Schedule of Long-Term Borrowings Maturities	The following table summarizes long-term borrowings maturing over the remainder of this year, over each of the next four years and thereafter (dollars in millions): September 30, 2024 2024 $ 1,025 2025 6,174 2026 4,941 2027 1,002 2028 1,452 Thereafter 2,833 Total $ 17,427

Preferred Stock (Tables)

Preferred Stock (Tables)	9 Months Ended
	Sep. 30, 2024
Equity [Abstract]
Schedule of Stock by Class	The table below presents a summary of the Company's non-cumulative perpetual preferred stock that is outstanding at September 30, 2024 (dollars in millions, except per depositary share amounts): Series Description Initial Issuance Date Liquidation Preference and Redemption Price per Depositary Share (1) Per Annum Dividend Rate in effect at September 30, 2024 Total Depositary Shares Authorized, Issued and Outstanding Carrying Value September 30, 2024 December 31, 2023 September 30, 2024 December 31, 2023 C (2)(3)(4) Fixed-to-Floating Rate 10/31/2017 $ 1,000 5.500 % 570,000 570,000 $ 563 $ 563 D (2)(5)(6) Fixed-Rate Reset 6/22/2020 $ 1,000 6.125 % 500,000 500,000 493 493 Total Preferred Stock 1,070,000 1,070,000 $ 1,056 $ 1,056 (1) Redeemable at the redemption price plus declared and unpaid dividends. (2) Issued as depositary shares, each representing 1/100 th interest in a share of the corresponding series of preferred stock. Each preferred share has a par value of $0.01. (3) Redeemable at the Company’s option, subject to regulatory approval, either (i) in whole or in part on any dividend payment date on or after October 30, 2027, or (ii) in whole but not in part, at any time within 90 days following a regulatory capital treatment event (as defined in the certificate of designations for the Series C preferred stock). (4) Any dividends declared are payable semi-annually in arrears at a rate of 5.500% per annum until October 30, 2027. Thereafter, dividends declared will be payable quarterly in arrears at a floating rate equal to 3-month Term SOFR plus a spread of 3.338% per annum. (5) Redeemable at the Company’s option, subject to regulatory approval, either (i) in whole or in part during the three-month period prior to, and including, each reset date (as defined in the certificate of designations for the Series D preferred stock) or (ii) in whole but not in part, at any time within 90 days following a regulatory capital treatment event (as defined in the certificate of designations for the Series D Preferred Stock). (6) Any dividends declared are payable semi-annually in arrears at a rate of 6.125% per annum until September 23, 2025, after which the dividend rate will reset every 5 years to a fixed annual rate equal to the 5-year Treasury plus a spread of 5.783%.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2024
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Changes in Accumulated Other Comprehensive Income (Loss)	Changes in each component of accumulated other comprehensive (loss) income ("AOCI") were as follows (dollars in millions): Unrealized (Losses) Gains on Available-for-Sale Investment Securities, Net of Tax (Losses) Gains on Cash Flow Hedges, Net of Tax Losses on Pension Plan, Net of Tax AOCI For the Three Months Ended September 30, 2024 Balance at June 30, 2024 $ (148) $ (70) $ (180) $ (398) Net change 239 176 — 415 Balance at September 30, 2024 $ 91 $ 106 $ (180) $ 17 For the Three Months Ended September 30, 2023 Balance at June 30, 2023 $ (195) $ (86) $ (189) $ (470) Net change (83) (20) — (103) Balance at September 30, 2023 $ (278) $ (106) $ (189) $ (573) For the Nine Months Ended September 30, 2024 Balance at December 31, 2023 $ (37) $ (8) $ (180) $ (225) Net change 128 114 — 242 Balance at September 30, 2024 $ 91 $ 106 $ (180) $ 17 For the Nine Months Ended September 30, 2023 Balance at December 31, 2022 $ (136) $ (14) $ (189) $ (339) Net change (142) (92) — (234) Balance at September 30, 2023 $ (278) $ (106) $ (189) $ (573)
Schedule of Other Comprehensive Income Before Reclassifications and Amounts Reclassified from AOCI	The following table presents each component of other comprehensive income ("OCI") before reclassifications and amounts reclassified from AOCI for each component of OCI before- and after-tax (dollars in millions): Before Tax Tax (Expense) Benefit Net of Tax For the Three Months Ended September 30, 2024 Available-for-Sale Investment Securities Net unrealized holding gains arising during the period $ 316 $ (77) $ 239 Net change $ 316 $ (77) $ 239 Cash Flow Hedges Net unrealized gains arising during the period $ 200 $ (48) $ 152 Amounts reclassified from AOCI 31 (7) 24 Net change $ 231 $ (55) $ 176 For the Three Months Ended September 30, 2023 Available-for-Sale Investment Securities Net unrealized holding losses arising during the period $ (111) $ 28 $ (83) Net change $ (111) $ 28 $ (83) Cash Flow Hedges Net unrealized losses arising during the period $ (55) $ 13 $ (42) Amounts reclassified from AOCI 29 (7) 22 Net change $ (26) $ 6 $ (20) For the Nine Months Ended September 30, 2024 Available-for-Sale Investment Securities Net unrealized holding gains arising during the period $ 169 $ (41) $ 128 Net change $ 169 $ (41) $ 128 Cash Flow Hedges Net unrealized gains arising during the period $ 38 $ (9) $ 29 Amounts reclassified from AOCI 112 (27) 85 Net change $ 150 $ (36) $ 114 For the Nine Months Ended September 30, 2023 Available-for-Sale Investment Securities Net unrealized holding losses arising during the period $ (188) $ 46 $ (142) Net change $ (188) $ 46 $ (142) Cash Flow Hedges Net unrealized losses arising during the period $ (172) $ 42 $ (130) Amounts reclassified from AOCI 50 (12) 38 Net change $ (122) $ 30 $ (92)

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Calculation	The following table presents the calculation of the Company's effective income tax rate (dollars in millions): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 (As Restated) (As Restated) Income before income taxes $ 1,192 $ 761 $ 4,372 $ 3,154 Income tax expense $ 322 $ 175 $ 1,128 $ 724 Effective income tax rate 27.0 % 23.0 % 25.8 % 23.0 %

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Schedule of Basic and Diluted EPS	The following table presents the calculation of basic and diluted earnings per share ("EPS") (dollars and shares in millions, except per share amounts): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 (As Restated) (As Restated) Numerator Net income $ 870 $ 586 $ 3,244 $ 2,430 Preferred stock dividends (31) (31) (62) (62) Net income available to common stockholders 839 555 3,182 2,368 Income allocated to participating securities (5) (5) (20) (17) Net income allocated to common stockholders $ 834 $ 550 $ 3,162 $ 2,351 Denominator Weighted-average shares of common stock outstanding 251 250 251 255 Weighted-average shares of common stock outstanding and common stock equivalents 251 250 251 255 Basic earnings per common share $ 3.32 $ 2.21 $ 12.61 $ 9.23 Diluted earnings per common share $ 3.32 $ 2.21 $ 12.61 $ 9.22

Capital Adequacy (Tables)

Capital Adequacy (Tables)	9 Months Ended
	Sep. 30, 2024
Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]
Schedule of Minimum and Well-Capitalized Requirements	The following table shows the actual capital amounts and ratios of DFS and Discover Bank and comparisons of each to the regulatory minimum and "well-capitalized" requirements (dollars in millions): Actual Minimum Capital Capital Requirements Amount Ratio (1) Amount Ratio Amount (2) Ratio (2) (As Restated) (As Restated) (As Restated) (As Restated) September 30, 2024 Total capital (to risk-weighted assets) Discover Financial Services $ 19,379 14.9 % $ 10,407 ≥8.0% $ 13,009 ≥10.0% Discover Bank $ 17,611 13.7 % $ 10,266 ≥8.0% $ 12,832 ≥10.0% Tier 1 capital (to risk-weighted assets) Discover Financial Services $ 17,373 13.4 % $ 7,805 ≥6.0% $ 7,805 ≥6.0% Discover Bank $ 14,877 11.6 % $ 7,699 ≥6.0% $ 10,266 ≥8.0% Tier 1 capital (to average assets) Discover Financial Services $ 17,373 11.4 % $ 6,080 ≥4.0% N/A N/A Discover Bank $ 14,877 9.9 % $ 6,012 ≥4.0% $ 7,515 ≥5.0% Common Equity Tier 1 (to risk-weighted assets) Discover Financial Services $ 16,317 12.5 % $ 5,854 ≥4.5% N/A N/A Discover Bank $ 14,877 11.6 % $ 5,775 ≥4.5% $ 8,341 ≥6.5% December 31, 2023 Total capital (to risk-weighted assets) Discover Financial Services $ 17,399 13.2 % $ 10,509 ≥8.0% $ 13,137 ≥10.0% Discover Bank $ 16,409 12.7 % $ 10,381 ≥8.0% $ 12,976 ≥10.0% Tier 1 capital (to risk-weighted assets) Discover Financial Services $ 15,279 11.6 % $ 7,882 ≥6.0% $ 7,882 ≥6.0% Discover Bank $ 13,459 10.4 % $ 7,786 ≥6.0% $ 10,381 ≥8.0% Tier 1 capital (to average assets) Discover Financial Services $ 15,279 10.3 % $ 5,915 ≥4.0% N/A N/A Discover Bank $ 13,459 9.2 % $ 5,833 ≥4.0% $ 7,292 ≥5.0% Common Equity Tier 1 (to risk-weighted assets) Discover Financial Services $ 14,223 10.8 % $ 5,911 ≥4.5% N/A N/A Discover Bank $ 13,459 10.4 % $ 5,839 ≥4.5% $ 8,435 ≥6.5% (1) Capital ratios are calculated based on the Basel III standardized approach rules, subject to applicable transition provisions, including CECL transition provisions. (2) The Basel III rules do not establish well-capitalized thresholds for these measures for bank holding companies. Existing well-capitalized thresholds established in the Federal Reserve's Regulation Y have been included where available.

Commitments, Contingencies an_2

Commitments, Contingencies and Guarantees (Tables)	9 Months Ended
	Sep. 30, 2024
Guarantor Obligations [Line Items]
Schedule of Maximum Potential Counterparty Exposures Related to Settlement Guarantees and Merchant Chargeback Guarantee	The following table summarizes certain information regarding merchant chargeback guarantees (dollars in millions): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 Aggregate sales transaction volume (1) $ 61,166 $ 65,490 $ 184,384 $ 192,173 (1) Represents transactions processed on the Discover Network for which a potential liability exists that, in aggregate, can differ from credit card sales volume.

Litigation and Regulatory Mat_2

Litigation and Regulatory Matters (Tables)	9 Months Ended
	Sep. 30, 2024
Card Product Misclassification Merchant and Merchant acquirers
Counterparty Counterparty Restitution Liability [Line Items]
Counterparty Counterparty Restitution Liability [Table]	The following table summarizes the change in the Company's counterparty restitution liability pertaining to the card product misclassification (dollars in millions): For the Nine Months Ended September 30, 2024 Balance at December 31, 2023 $ 1,159 Provision for refund of overcharges — Provision for interest on overcharges 42 Provision for other settlement concessions 76 Disbursements (76) Balance at September 30, 2024 $ 1,201

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	Assets and liabilities measured at fair value on a recurring basis are as follows (dollars in millions): Quoted Price Significant Significant Total Balance at September 30, 2024 Assets Fair value - OCI U.S. Treasury and U.S. GSE securities $ 14,177 $ 8 $ — $ 14,185 Residential mortgage-backed securities - Agency — 405 — 405 Available-for-sale investment securities $ 14,177 $ 413 $ — $ 14,590 Liabilities Fair value - OCI Derivative financial instruments - cash flow hedges (1) $ — $ 18 $ — $ 18 Fair value - Net income Derivative financial instruments - fair value hedges (1) $ — $ 19 $ — $ 19 Balance at December 31, 2023 Assets Fair value - OCI U.S. Treasury and U.S. GSE securities $ 12,928 $ 9 $ — $ 12,937 Residential mortgage-backed securities - Agency — 465 — 465 Available-for-sale investment securities $ 12,928 $ 474 $ — $ 13,402 Derivative financial instruments - cash flow hedges (1) $ — $ 2 $ — $ 2 Fair value - Net income Marketable equity securities $ 1 $ — $ — $ 1 Derivative financial instruments - fair value hedges (1) $ — $ 2 $ — $ 2 . (1) Derivative instrument carrying values in an asset or liability position are presented as part of other assets or accrued expenses and other liabilities, respectively, in the Company's condensed consolidated statements of financial condition.
Schedule of Financial Instruments Measured at Other Than Fair Value	The following tables disclose the estimated fair value of the Company's financial assets and financial liabilities that are not required to be carried at fair value (dollars in millions): Balance at September 30, 2024 Quoted Prices in Active Markets Significant Significant Total Carrying Assets Amortized cost Residential mortgage-backed securities - Agency $ — $ 260 $ — $ 260 $ 275 Held-to-maturity investment securities $ — $ 260 $ — $ 260 $ 275 Net loan receivables (1) $ — $ 8,878 $ 117,553 $ 126,431 $ 118,481 Carrying value approximates fair value (2) Cash and cash equivalents $ 10,787 $ — $ — $ 10,787 $ 10,787 Restricted cash $ 36 $ — $ — $ 36 $ 36 Other short-term investments $ 735 $ — $ — $ 735 $ 735 Accrued interest receivables (3)(4) $ — $ 1,324 $ — $ 1,324 $ 1,309 Liabilities Amortized cost Time deposits (5) $ — $ 46,338 $ — $ 46,338 $ 46,076 Short-term borrowings $ — $ 750 $ — $ 750 $ 750 Long-term borrowings - owed to securitization investors $ — $ 8,448 $ 54 $ 8,502 $ 8,557 Other long-term borrowings — 9,043 — 9,043 8,870 Long-term borrowings $ — $ 17,491 $ 54 $ 17,545 $ 17,427 Carrying value approximates fair value (2) Accrued interest payables (3) $ — $ 396 $ — $ 396 $ 396 Balance at December 31, 2023 Assets Amortized cost Residential mortgage-backed securities - Agency $ — $ 234 $ — $ 234 $ 253 Held-to-maturity investment securities $ — $ 234 $ — $ 234 $ 253 Net loan receivables $ — $ — $ 126,940 $ 126,940 $ 119,126 Carrying value approximates fair value (2) Cash and cash equivalents $ 11,685 $ — $ — $ 11,685 $ 11,685 Restricted cash $ 43 $ — $ — $ 43 $ 43 Accrued interest receivables (3) $ — $ 1,450 $ — $ 1,450 $ 1,450 Liabilities Amortized cost Time deposits (5) $ — $ 45,333 $ — $ 45,333 $ 45,240 Short-term borrowings $ — $ 750 $ — $ 750 $ 750 Long-term borrowings - owed to securitization investors $ — $ 10,770 $ 65 $ 10,835 $ 10,993 Other long-term borrowings — 9,469 — 9,469 9,588 Long-term borrowings $ — $ 20,239 $ 65 $ 20,304 $ 20,581 Carrying value approximates fair value (2) Accrued interest payables (3) $ — $ 421 $ — $ 421 $ 421 (1) Includes $8.9 billion in private student loans held-for-sale valued based on the terms of the executed purchase agreement. The carrying value for loans held-for-sale represents the lower of amortized cost or fair value while the carrying value for the loan portfolio is amortized cost, net of the allowance for credit losses. (2) The carrying values of these assets and liabilities approximate fair value due to their short-term nature, except as otherwise indicated. (3) Accrued interest receivable and payable carrying values are presented as part of other assets and accrued expenses and other liabilities, respectively, in the Company's condensed consolidated statements of financial condition. (4) The fair value includes a premium associated with interest to be capitalized on private student loans held-for-sale based on the terms of the executed purchase agreement. (5) Excludes deposits without contractually defined maturities for all periods presented.

Derivatives and Hedging Activ_2

Derivatives and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Fair Value and Outstanding Notional Amounts of Derivative Instruments and Related Collateral Balances	The following table summarizes the fair value (including accrued interest) and outstanding notional amounts of derivative instruments and related collateral balances (dollars in millions): September 30, 2024 December 31, 2023 Notional Number of Outstanding Derivative Contracts Derivative Assets Derivative Liabilities Notional Derivative Assets Derivative Liabilities Derivatives designated as hedges Interest rate swaps—cash flow hedge $ 15,000 20 $ — $ 18 $ 10,650 $ 2 $ — Interest rate swaps—fair value hedge $ 15,371 19 — 19 $ 8,650 2 — Derivatives not designated as hedges Foreign exchange forward contracts (1) $ 33 6 — — $ 29 — — Total gross derivative assets/liabilities (2) — 37 4 — Less: collateral held/posted (3) — (37) — — Total net derivative assets/liabilities $ — $ — $ 4 $ — (1) The foreign exchange forward contracts have notional amounts of EUR 6 million, GBP 6 million, SGD 1 million and INR 1.5 billion as of September 30, 2024, and notional amounts of EUR 6 million, GBP 6 million, SGD 1 million, INR 1.1 billion and AUD 2 million as of December 31, 2023. (2) In addition to the derivatives disclosed in the table, the Company enters into forward contracts to purchase when-issued mortgage-backed securities and tax exempt single family mortgage revenue bonds as part of its community reinvestment initiatives. At September 30, 2024, the Company had no outstanding contracts. At December 31, 2023, the Company had one outstanding contract with a total notional amount of $35 million and an immaterial fair value. (3) Collateral amounts, which consist of cash and investment securities, are limited to the related derivative asset/liability balance and do not include excess collateral received/pledged.
Schedule of Hedged Items in Fair Value Hedging Relationship	The following amounts were recorded on the statements of financial condition related to cumulative basis adjustments for fair value hedges (dollars in millions): September 30, 2024 December 31, 2023 Carrying Amount of Hedged Liabilities Cumulative Amount of Fair Value Hedging Adjustment Increasing the Carrying Amount of Hedged Liabilities (1) Carrying Amount of Hedged Liabilities Cumulative Amount of Fair Value Hedging Adjustment Increasing/(Decreasing) the Carrying Amount of Hedged Liabilities (1) Long-term borrowings $ 15,490 $ 162 $ 8,620 $ — (1) The balance includes $6 million and $12 million of cumulative hedging adjustments related to discontinued hedging relationships as of September 30, 2024 and December 31, 2023, respectively.
Schedule of Impact of the Derivative Instruments on Income	The following table summarizes the impact of the derivative instruments on income and indicates where within the condensed consolidated financial statements such impact is reported (dollars in millions): Location and Amount of (Losses) Gains Recognized on the Condensed Consolidated Statements of Income Interest Expense Interest Income (Credit Card) Other Expense Deposits Long-Term Borrowings For the Three Months Ended September 30, 2024 Total amounts of income and expense line items presented in the condensed consolidated statements of income, where the effects of fair value or cash flow hedges are recorded $ (1,213) $ (236) $ 4,092 $ (277) The effects of cash flow and fair value hedging Gains (losses) on cash flow hedging relationships Amounts reclassified from OCI into earnings $ — $ 4 $ (48) $ — Gains on discontinued cash flow hedging relationships Amounts reclassified from OCI into earnings $ — $ — $ — $ 13 (Losses) gains on fair value hedging relationships Losses on hedged items $ (90) $ (187) $ — $ — Gains on interest rate swaps 81 145 — — Total losses on fair value hedging relationships $ (9) $ (42) $ — $ — For the Three Months Ended September 30, 2023 Total amounts of income and expense line items presented in the condensed consolidated statements of income, where the effects of fair value or cash flow hedges are recorded $ (1,061) $ (225) $ 3,726 $ (254) The effects of cash flow and fair value hedging Gains (losses) on cash flow hedging relationships Amounts reclassified from OCI into earnings $ — $ 2 $ (31) $ — Gains (losses) on fair value hedging relationships Gains on hedged items $ — $ 24 $ — $ — Losses on interest rate swaps — (53) — — Total losses on fair value hedging relationships $ — $ (29) $ — $ — Location and Amount of (Losses) Gains Recognized on the Condensed Consolidated Statements of Income Interest Expense Interest Income (Credit Card) Other Expense Deposits Long-Term Borrowings For the Nine Months Ended September 30, 2024 Total amounts of income and expense line items presented in the condensed consolidated statements of income, where the effects of fair value or cash flow hedges are recorded $ (3,622) $ (729) $ 11,989 $ (761) The effects of cash flow and fair value hedging Gains (losses) on cash flow hedging relationships Amounts reclassified from OCI into earnings $ — $ 9 $ (134) $ — Gains on discontinued cash flow hedging relationships Amounts reclassified from OCI into earnings $ — $ — $ — $ 13 (Losses) gains on fair value hedging relationships Losses on hedged items $ (91) $ (76) $ — $ — Gains (losses) on interest rate swaps 75 (40) — — Total losses on fair value hedging relationships $ (16) $ (116) $ — $ — For the Nine Months Ended September 30, 2023 Total amounts of income and expense line items presented in the condensed consolidated statements of income, where the effects of fair value or cash flow hedges are recorded $ (2,722) $ (622) $ 10,513 $ (540) The effects of cash flow and fair value hedging Gains (losses) on cash flow hedging relationships Amounts reclassified from OCI into earnings $ — $ 6 $ (56) $ — Gains (losses) on fair value hedging relationships Gains on hedged items $ — $ 111 $ — $ — Losses on interest rate swaps — (181) — — Total losses on fair value hedging relationships $ — $ (70) $ — $ —

Segment Disclosures (Tables)

Segment Disclosures (Tables)	9 Months Ended
	Sep. 30, 2024
Segment Reporting [Abstract]
Schedule of Segment Disclosures	The following table presents segment data (dollars in millions): Digital Payment Total For the Three Months Ended September 30, 2024 Interest income Credit card loans $ 4,092 $ — $ 4,092 Private student loans 244 — 244 Personal loans 360 — 360 Other loans 138 — 138 Other interest income 278 — 278 Total interest income 5,112 — 5,112 Interest expense 1,457 — 1,457 Net interest income 3,655 — 3,655 Provision for credit losses 1,473 — 1,473 Other income 669 129 798 Other expense 1,743 45 1,788 Income before income taxes $ 1,108 $ 84 $ 1,192 For the Three Months Ended September 30, 2023 (As Restated) Interest income Credit card loans $ 3,726 $ — $ 3,726 Private student loans 261 — 261 Personal loans 305 — 305 Other loans 87 — 87 Other interest income 231 — 231 Total interest income 4,610 — 4,610 Interest expense 1,288 — 1,288 Net interest income 3,322 — 3,322 Provision for credit losses 1,702 — 1,702 Other income 575 130 705 Other expense 1,519 45 1,564 Income before income taxes $ 676 $ 85 $ 761 Digital Payment Total For the Nine Months Ended September 30, 2024 Interest income Credit card loans $ 11,989 $ — $ 11,989 Private student loans 764 — 764 Personal loans 1,040 — 1,040 Other loans 379 — 379 Other interest income 859 — 859 Total interest income 15,031 — 15,031 Interest expense 4,365 — 4,365 Net interest income 10,666 — 10,666 Provision for credit losses 3,709 — 3,709 Other income 1,901 584 2,485 Other expense 4,929 141 5,070 Income before income taxes $ 3,929 $ 443 $ 4,372 For the Nine Months Ended September 30, 2023 (As Restated) Interest income Credit card loans $ 10,513 $ — $ 10,513 Private student loans 768 — 768 Personal loans 831 — 831 Other loans 224 — 224 Other interest income 641 — 641 Total interest income 12,977 — 12,977 Interest expense 3,346 — 3,346 Net interest income 9,631 — 9,631 Provision for credit losses 4,109 — 4,109 Other income 1,650 333 1,983 Other expense 4,220 131 4,351 Income before income taxes $ 2,952 $ 202 $ 3,154

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Schedule of Revenue from Contracts with Customers Disaggregated by Business Segment	The following table presents revenue from contracts with customers disaggregated by business segment and reconciles revenue from contracts with customers to total other income (dollars in millions): Digital Banking Payment Services Total For the Three Months Ended September 30, 2024 Other income subject to ASC 606 Discount and interchange revenue, net (1) $ 337 $ 26 $ 363 Protection products revenue 42 — 42 Transaction processing revenue — 84 84 Other income 76 19 95 Total other income subject to ASC 606 (2) 455 129 584 Other income not subject to ASC 606 Loan fee income 214 — 214 Total other income not subject to ASC 606 214 — 214 Total other income by operating segment $ 669 $ 129 $ 798 For the Three Months Ended September 30, 2023 (As Restated) Other income subject to ASC 606 Discount and interchange revenue, net (1) $ 337 $ 23 $ 360 Protection products revenue 42 — 42 Transaction processing revenue — 82 82 Other income 2 19 21 Total other income subject to ASC 606 (2) 381 124 505 Other income not subject to ASC 606 Loan fee income 194 — 194 Other income — 6 6 Total other income not subject to ASC 606 194 6 200 Total other income by operating segment $ 575 $ 130 $ 705 Digital Banking Payment Services Total For the Nine Months Ended September 30, 2024 Other income subject to ASC 606 Discount and interchange revenue, net (1) $ 1,044 $ 77 $ 1,121 Protection products revenue 126 — 126 Transaction processing revenue — 262 262 Other income 112 245 357 Total other income subject to ASC 606 (2) 1,282 584 1,866 Other income not subject to ASC 606 Loan fee income 619 — 619 Total other income not subject to ASC 606 619 — 619 Total other income by operating segment $ 1,901 $ 584 $ 2,485 For the Nine Months Ended September 30, 2023 (As Restated) Other income subject to ASC 606 Discount and interchange revenue, net (1) $ 963 $ 64 $ 1,027 Protection products revenue 129 — 129 Transaction processing revenue — 221 221 Other income 12 59 71 Total other income subject to ASC 606 (2) 1,104 344 1,448 Other income not subject to ASC 606 Loan fee income 546 — 546 Other income (loss) — (11) (11) Total other income (loss) not subject to ASC 606 546 (11) 535 Total other income by operating segment $ 1,650 $ 333 $ 1,983 (1) Net of rewards, including Cashback Bonus rewards, of $779 million and $787 million for the three months ended September 30, 2024 and 2023, respectively, and $2.2 billion and $2.3 billion for the nine months ended September 30, 2024 and 2023 , respectively. (2) Excludes $2 million and $3 million of deposit product fees that are reported within net interest income for the three months ended September 30, 2024 and 2023, respectively, and $6 million and $13 million for the nine months ended September 30, 2024 and 2023, respectively.

Background and Basis of Prese_3

Background and Basis of Presentation (Narrative) (Details) $ in Millions		3 Months Ended	9 Months Ended
		Sep. 30, 2024 USD ($) numberOfDirectors	Sep. 30, 2024 USD ($) numberOfDirectors segment	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Background and Basis of Presentation [Line Items]
Number of reportable segments (in number of segments) | segment			2
Gain related to loans sold			$ 70	$ 0
Financing Receivable, Held-for-Sale		$ 8,484	8,484		$ 0
Total Other Loans [Member] | Private Student Loans [Member]
Background and Basis of Presentation [Line Items]
Gain related to loans sold		70
Financing Receivable, Held-for-Sale	[1],[2]	8,484	8,484		$ 0
Expected Sale Price of loans held-for-sale		$ 9,000	9,000
Discover Financial Services | Capital One Financial Corporation
Background and Basis of Presentation [Line Items]
Business Combination, Price of Acquisition, Expected			$ 35,300
Business Acquisition, Number of Common Stock Shares Issued for each Share of Acquiree Stock		1.0192	1.0192
Business Acquisition Acquirer's Percentage Ownership in Combined Entity		0.60	0.60
Business Acquisition Acquiree's Percentage Ownership in Combined Entity		0.40	0.40
Business Acquisition, Number of Directors on Combined Entity BOD | numberOfDirectors		15	15
Business Acquisition, Number of Directors on Combined Entity BOD from Acquirer | numberOfDirectors		12	12
Business Acquisition, Number of Directors on Combined Entity BOD from Acquiree | numberOfDirectors		3	3
[1] Accrued interest receivable on private student, personal and other loans, which is presented as part of other assets in the Company's condensed consolidated statements of financial condition, was $372 million, $74 million and $28 million, respectively, at September 30, 2024 and $522 million, $69 million and $21 million, respectively, at December 31, 2023. At September 30, 2024, the private student loan portfolio was classified as held-for-sale and there were $6.0 billion of private student loans in repayment. At December 31, 2023, the private student loan portfolio was classified as held-for-investment and there were $6.3 billion of private student loans in repayment.

Investments (Narrative) (Detail

Investments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Summary of Investment Holdings [Line Items]
Proceeds from the sale of available-for-sale securities	$ 0	$ 0	$ 0	$ 0
Debt Securities, Available-for-Sale, Gain (Loss)	0	$ 0	$ 0	$ 0
Investment Program, Proportional Amortization Method, Policy Election [true false]			true
Affordable housing project equity method investments	451		$ 451		$ 514
Amortization Method Qualified Affordable Housing Project Investments, Amortization	15		46
Affordable Housing Tax Credits and Other Tax Benefits, Amount	$ 17		$ 52
Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, before Amortization, Statement of Cash Flows [Extensible Enumeration]	Net Cash Provided by (Used in) Operating Activities		Net Cash Provided by (Used in) Operating Activities
Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Cash Flows [Extensible Enumeration]	Net Cash Provided by (Used in) Operating Activities		Net Cash Provided by (Used in) Operating Activities
Investment, Proportional Amortization Method, Elected, Statement of Financial Position [Extensible Enumeration]	Other assets		Other assets		Other assets
Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, before Amortization, Statement of Income or Comprehensive Income [Extensible Enumeration]	Income tax expense		Income tax expense
Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Income or Comprehensive Income [Extensible Enumeration]	Income tax expense		Income tax expense
Other Assets [Member] | Payment Services [Member]
Summary of Investment Holdings [Line Items]
Equity securities without readily determinable fair value	$ 38		$ 38		$ 35
Other Liabilities [Member]
Summary of Investment Holdings [Line Items]
Contingent liabilities related to affordable housing project equity method investments	$ 156		$ 156		$ 187

Investments (Schedule of Invest

Investments (Schedule of Investment Securities) (Details) - USD ($) $ in Millions		Sep. 30, 2024	Dec. 31, 2023
Summary of Investment Holdings [Line Items]
Other short-term investments		$ 735	$ 0
Investment securities		14,865	13,655
US Treasury Bill Securities [Member] | Asset Not Pledged as Collateral [Member]
Summary of Investment Holdings [Line Items]
Other short-term investments	[1]	735	0
US Treasury and Government
Summary of Investment Holdings [Line Items]
Investment securities	[2]	14,185	12,937
Residential Mortgage-Backed Securities - Agency [Member]
Summary of Investment Holdings [Line Items]
Investment securities	[3]	680	718
U.S. Treasury Securities [Member] | Asset Pledged as Collateral [Member]
Summary of Investment Holdings [Line Items]
Derivative collateral		$ 407	$ 320
[1] Includes U.S. Treasury bills with maturity dates greater than 90 days but less than one year at the time of acquisition. Includes $407 million and $320 million of U.S. Treasury securities pledged as swap collateral as of September 30, 2024 and December 31, 2023, respectively. (3) Consists of securities issued by the Federal Home Loan Bank ("FHLB").

Investments (Schedule of Amorti

Investments (Schedule of Amortized Cost, Gross Unrealized Gains, Gross Unrealized Losses and Fair Value) (Details) - USD ($) $ in Millions		Sep. 30, 2024		Dec. 31, 2023
Summary of Investment Holdings [Line Items]
Available-for-sale investment securities, amortized cost	[1]	$ 14,470		$ 13,451
Available-for-sale investment securities, gross unrealized gains	[1]	146		52
Available-for-sale investment securities, gross unrealized losses	[1]	(26)		(101)
Available-for-sale investment securities, fair value	[1]	14,590		13,402
Held-to-maturity investment securities, amortized cost	[2]	275		253
Held-to-maturity investment securities, gross unrealized gains	[2]	2		0
Held-to-maturity investment securities, gross unrealized losses	[2]	(17)		(19)
Held-to-maturity investment securities, fair value	[2]	260		234
US Treasury and Government
Summary of Investment Holdings [Line Items]
Available-for-sale investment securities, amortized cost	[1]	14,058		12,971
Available-for-sale investment securities, gross unrealized gains	[1]	146		52
Available-for-sale investment securities, gross unrealized losses	[1]	(19)		(86)
Available-for-sale investment securities, fair value	[1]	14,185		12,937
Residential Mortgage-Backed Securities - Agency [Member]
Summary of Investment Holdings [Line Items]
Available-for-sale investment securities, amortized cost	[1]	412	[3]	480
Available-for-sale investment securities, gross unrealized gains	[1]	0		0
Available-for-sale investment securities, gross unrealized losses	[1]	(7)		(15)
Available-for-sale investment securities, fair value	[1]	405	[3]	465
Held-to-maturity investment securities, amortized cost	[2],[4]	275	[3]	253
Held-to-maturity investment securities, gross unrealized gains	[2],[4]	2		0
Held-to-maturity investment securities, gross unrealized losses	[2],[4]	(17)		(19)
Held-to-maturity investment securities, fair value	[2],[4]	$ 260	[3]	$ 234
[1] Available-for-sale investment securities are reported at fair value. Held-to-maturity investment securities are reported at amortized cost. Maturities of RMBS are reflective of the contractual maturities of the investment. Amounts represent residential mortgage-backed securities ("RMBS") that were classified as held-to-maturity as they were entered into as a part of the Company's community reinvestment initiatives.

Investments (Schedule of Fair V

Investments (Schedule of Fair Value of Securities in a Continuous Unrealized Loss Position for Less Than 12 Months and More Than 12 Months) (Details) $ in Millions	Sep. 30, 2024 USD ($) securities	Dec. 31, 2023 USD ($) securities
US Treasury and Government
Summary of Investment Holdings [Line Items]
Available-for-sale investment securities, continuous unrealized loss position, number of securities | securities	31	105
Available-for-sale investment securities, continuous unrealized loss position, less than 12 months, fair value	$ 1,137	$ 3,513
Available-for-sale securities, continuous unrealized loss position, less than 12 months, accumulated loss	(2)	(13)
Debt securities, available-for-sale, continuous unrealized loss position, 12 months or longer, fair value	2,593	3,978
Available-for-sale investment securities, continuous unrealized loss position, more than 12 months, unrealized losses	$ (17)	$ (73)
Residential Mortgage-Backed Securities - Agency [Member]
Summary of Investment Holdings [Line Items]
Available-for-sale investment securities, continuous unrealized loss position, number of securities | securities	30	31
Available-for-sale investment securities, continuous unrealized loss position, less than 12 months, fair value	$ 0	$ 0
Available-for-sale securities, continuous unrealized loss position, less than 12 months, accumulated loss	0	0
Debt securities, available-for-sale, continuous unrealized loss position, 12 months or longer, fair value	405	465
Available-for-sale investment securities, continuous unrealized loss position, more than 12 months, unrealized losses	$ (7)	$ (15)

Investments (Schedule of Maturi

Investments (Schedule of Maturities of Available-for-Sale Debt Securities and Held-to-Maturity Debt Securities) (Details) - USD ($) $ in Millions		Sep. 30, 2024		Dec. 31, 2023
Summary of Investment Holdings [Line Items]
Available-for-sale investment securities, debt maturities, one year or less, amortized cost		$ 2,193
Available-for-sale investment securities, debt maturities, after one year through five years, amortized cost		11,844
Available-for-sale investment securities, debt maturities, after five years through ten years, amortized cost		179
Available-for-sale investment securities, debt maturities, after ten years, amortized cost		254
Available-for-sale investment securities, amortized cost	[1]	14,470		$ 13,451
Held-to-maturity investment securities, debt maturities, one year or less, amortized cost		0
Held-to-maturity investment securities, debt maturities, after one year through five years, amortized cost		0
Held-to-maturity investment securities, debt maturities, after five years through ten years, amortized cost		0
Held-to-maturity investment securities, debt maturities, after ten years, amortized cost		275
Held-to-maturity investment securities, amortized cost	[2]	275		253
Available-for-sale investment securities, debt maturities, one year or less, fair value		2,183
Available-for-sale investment securities, debt maturities, after one year through five years, fair value		11,976
Available-for-sale investment securities, debt maturities, after five years through ten years, fair value		181
Available-for-sale investment securities, debt maturities, after ten years, fair value		250
Available-for-sale investment securities, fair value	[1]	14,590		13,402
Held-to-maturity investment securities, debt maturities, one year or less, fair value		0
Held-to-maturity investment securities, debt maturities, after one year through five years, fair value		0
Held-to-maturity investment securities, debt maturities, after five years through ten years, fair value		0
Held-to-maturity investment securities, debt maturities, after ten years, fair value		260
Held-to-maturity investment securities, fair value	[2]	260		234
US Treasury and Government
Summary of Investment Holdings [Line Items]
Available-for-sale investment securities, debt maturities, one year or less, amortized cost		2,193
Available-for-sale investment securities, debt maturities, after one year through five years, amortized cost		11,792
Available-for-sale investment securities, debt maturities, after five years through ten years, amortized cost		73
Available-for-sale investment securities, debt maturities, after ten years, amortized cost		0
Available-for-sale investment securities, amortized cost	[1]	14,058		12,971
Available-for-sale investment securities, debt maturities, one year or less, fair value		2,183
Available-for-sale investment securities, debt maturities, after one year through five years, fair value		11,926
Available-for-sale investment securities, debt maturities, after five years through ten years, fair value		76
Available-for-sale investment securities, debt maturities, after ten years, fair value		0
Available-for-sale investment securities, fair value	[1]	14,185		12,937
Residential Mortgage-Backed Securities - Agency [Member]
Summary of Investment Holdings [Line Items]
Available-for-sale investment securities, debt maturities, one year or less, amortized cost	[3]	0
Available-for-sale investment securities, debt maturities, after one year through five years, amortized cost	[3]	52
Available-for-sale investment securities, debt maturities, after five years through ten years, amortized cost	[3]	106
Available-for-sale investment securities, debt maturities, after ten years, amortized cost	[3]	254
Available-for-sale investment securities, amortized cost	[1]	412	[3]	480
Held-to-maturity investment securities, debt maturities, one year or less, amortized cost	[3]	0
Held-to-maturity investment securities, debt maturities, after one year through five years, amortized cost	[3]	0
Held-to-maturity investment securities, debt maturities, after five years through ten years, amortized cost	[3]	0
Held-to-maturity investment securities, debt maturities, after ten years, amortized cost	[3]	275
Held-to-maturity investment securities, amortized cost	[2],[4]	275	[3]	253
Available-for-sale investment securities, debt maturities, one year or less, fair value	[3]	0
Available-for-sale investment securities, debt maturities, after one year through five years, fair value	[3]	50
Available-for-sale investment securities, debt maturities, after five years through ten years, fair value	[3]	105
Available-for-sale investment securities, debt maturities, after ten years, fair value	[3]	250
Available-for-sale investment securities, fair value	[1]	405	[3]	465
Held-to-maturity investment securities, debt maturities, one year or less, fair value	[3]	0
Held-to-maturity investment securities, debt maturities, after one year through five years, fair value	[3]	0
Held-to-maturity investment securities, debt maturities, after five years through ten years, fair value	[3]	0
Held-to-maturity investment securities, debt maturities, after ten years, fair value	[3]	260
Held-to-maturity investment securities, fair value	[2],[4]	$ 260	[3]	$ 234
[1] Available-for-sale investment securities are reported at fair value. Held-to-maturity investment securities are reported at amortized cost. Maturities of RMBS are reflective of the contractual maturities of the investment. Amounts represent residential mortgage-backed securities ("RMBS") that were classified as held-to-maturity as they were entered into as a part of the Company's community reinvestment initiatives.

Loan Receivables (Narrative) (D

Loan Receivables (Narrative) (Details) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2024 USD ($)	Mar. 31, 2024	Dec. 31, 2023 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) segment	Sep. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan portfolio segments (in segments) | segment					2
Allowance for credit losses	$ 8,512		$ 9,283	$ 8,665	$ 8,512	$ 8,665	$ 8,481	$ 8,064	$ 7,374
Allowance for credit losses, period increase (decrease)	$ 31				$ (771)
Expected EOY Unemployment Rate	4.35%				4.35%
Expected Future Peak Unemployment Rate	4.62%				4.62%
Expected EY Annualized Increase in GDP	2.54%				2.54%
Reasonable and supportable forecast period	18 months	18 months	18 months	18 months	18 months	18 months
Reversion period					12 months	12 months
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Delinquent Loan Qualification Period					30 days
Personal Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Temporary Reduced Payment Program, Maximum Period of Payment Reduction					12 months
Maximum repayment term for permanent modification programs (in years)					9 years
Credit Card Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ 7,586		$ 7,619	$ 7,070	$ 7,586	$ 7,070	$ 7,591	$ 6,525	$ 5,883
Temporary Reduced Payment Program, Maximum Period of Payment Reduction					12 months
Permanent workout program maturity (in months)					72 months

Loan Receivables (Schedule of L

Loan Receivables (Schedule of Loan Receivables) (Details) - USD ($) $ in Millions		Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Held-for-Sale		$ 8,484		$ 0
Loan portfolio		126,993		128,409
Loan Portfolio, excluding held for sale		118,509		128,409
Allowance for credit losses		(8,512)	$ (8,481)	(9,283)	$ (8,665)	$ (8,064)	$ (7,374)
Net loan receivables		118,481		119,126
Variable Interest Entity, Primary Beneficiary [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Held-for-Sale		132		0
Loan portfolio				30,590
Loan Portfolio, excluding held for sale		28,643
Allowance for credit losses		(1,334)		(1,347)
Credit Card Securitization Trusts [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	[1]	28,643		30,440
Allowance for credit losses	[1]	(1,334)		(1,347)
Net loan receivables		27,309		29,093
Seller's interest		16,934		15,598
Total Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	[2]	18,020		26,150
Total Other Loans [Member] | Private Student Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Held-for-Sale	[2],[3]	8,484		0
Loan portfolio	[2],[3]	0		10,352
Allowance for credit losses		0	0	(858)	(866)	(849)	(839)
Accrued interest receivable		372		522
Private student loans in repayment held-for-sale		6,000
Private student loans in repayment				6,300
Total Other Loans [Member] | Personal Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	[2]	10,438		9,852
Allowance for credit losses		(798)	(793)	(722)	(653)	(622)	(595)
Accrued interest receivable		74		69
Total Other Loans [Member] | Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	[2]	7,582		5,946
Allowance for credit losses		(128)	(97)	(84)	(76)	(68)	(57)
Accrued interest receivable		28		21
Credit Card Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	[4],[5]	100,489		102,259
Allowance for credit losses		(7,586)	$ (7,591)	(7,619)	$ (7,070)	$ (6,525)	$ (5,883)
Accrued interest receivable		726		753
Credit Card Loans [Member] | Credit Card Securitization Trusts [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investors' interest		11,700		14,800
Seller's interest		$ 16,900		$ 15,600
[1] The Company maintains its allowance for credit losses at an amount equal to lifetime expected credit losses associated with all loan receivables, which includes all loan receivables in the trusts. Therefore, the credit risk associated with the transferred receivables is fully reflected on the Company's statements of financial condition in accordance with GAAP. Accrued interest receivable on private student, personal and other loans, which is presented as part of other assets in the Company's condensed consolidated statements of financial condition, was $372 million, $74 million and $28 million, respectively, at September 30, 2024 and $522 million, $69 million and $21 million, respectively, at December 31, 2023. At September 30, 2024, the private student loan portfolio was classified as held-for-sale and there were $6.0 billion of private student loans in repayment. At December 31, 2023, the private student loan portfolio was classified as held-for-investment and there were $6.3 billion of private student loans in repayment. Amounts include carrying values of $11.7 billion and $14.8 billion underlying investors' interest in trust debt at September 30, 2024 and December 31, 2023, respectively, and $16.9 billion and $15.6 billion in seller's interest at September 30, 2024 and December 31, 2023, respectively. See Note 4: Credit Card and Private Student Loan Securitization Activities for additional information.

Loan Receivables (Schedule of C

Loan Receivables (Schedule of Credit Risk Profile by FICO Score and Origination Year) (Details) - USD ($) $ in Millions		Sep. 30, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio		$ 126,993	$ 128,409
Credit Card Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio	[1],[2]	100,489	102,259
Credit Card Loans [Member] | FICO Score, 660 and Above [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan receivables, credit card		$ 80,277	$ 82,238
FICO distribution %, credit card		80%	80%
Credit Card Loans [Member] | FICO Score, Less Than 660 Or No Score [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan receivables, credit card		$ 20,212	$ 20,021
FICO distribution %, credit card		20%	20%
Total Other Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio	[3]	$ 18,020	$ 26,150
Total Other Loans [Member] | Personal Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio	[3]	10,438	9,852
Total Other Loans [Member] | Personal Loans [Member] | FICO Score, 660 and Above [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan receivables, originated in current fiscal year		$ 3,915
FICO distribution %, originated in current fiscal year		99%
Loan receivables, originated in fiscal year before current fiscal year		$ 3,533	$ 5,149
FICO distribution %, originated in fiscal year before current fiscal year		95%	98%
Loan receivables, originated in two years before current fiscal year		$ 1,623	$ 2,604
FICO distribution %, originated in two years before current fiscal year		91%	93%
Loan receivables, originated in three years before current fiscal year		$ 588	$ 1,049
FICO distribution %, originated in three years before current fiscal year		90%	92%
Loan receivables, originated in four years before current fiscal year		$ 177	$ 355
FICO distribution %, originated in four years before current fiscal year		91%	92%
Loan receivables, originated prior to more than five years before current fiscal year		$ 100	$ 247
FICO distribution %, originated prior to more than five years before current fiscal year		83%	86%
Loan portfolio		$ 9,936	$ 9,404
FICO distribution %, loan receivables		95%	95%
Total Other Loans [Member] | Personal Loans [Member] | FICO Score, Less Than 660 Or No Score [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan receivables, originated in current fiscal year		$ 37
FICO distribution %, originated in current fiscal year		1%
Loan receivables, originated in fiscal year before current fiscal year		$ 192	$ 100
FICO distribution %, originated in fiscal year before current fiscal year		5%	2%
Loan receivables, originated in two years before current fiscal year		$ 169	$ 187
FICO distribution %, originated in two years before current fiscal year		9%	7%
Loan receivables, originated in three years before current fiscal year		$ 67	$ 91
FICO distribution %, originated in three years before current fiscal year		10%	8%
Loan receivables, originated in four years before current fiscal year		$ 17	$ 29
FICO distribution %, originated in four years before current fiscal year		9%	8%
Loan receivables, originated prior to more than five years before current fiscal year		$ 20	$ 41
FICO distribution %, originated prior to more than five years before current fiscal year		17%	14%
Loan portfolio		$ 502	$ 448
FICO distribution %, loan receivables		5%	5%
[1] Amounts include carrying values of $11.7 billion and $14.8 billion underlying investors' interest in trust debt at September 30, 2024 and December 31, 2023, respectively, and $16.9 billion and $15.6 billion in seller's interest at September 30, 2024 and December 31, 2023, respectively. See Note 4: Credit Card and Private Student Loan Securitization Activities for additional information. Accrued interest receivable on private student, personal and other loans, which is presented as part of other assets in the Company's condensed consolidated statements of financial condition, was $372 million, $74 million and $28 million, respectively, at September 30, 2024 and $522 million, $69 million and $21 million, respectively, at December 31, 2023.

Loan Receivables (Schedule of D

Loan Receivables (Schedule of Delinquent Loans by Origination Year) (Details) - USD ($) $ in Millions		Sep. 30, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio		$ 126,993	$ 128,409
Credit Card Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio	[1],[2]	100,489	102,259
Total Other Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio	[3]	18,020	26,150
Total Other Loans [Member] | Personal Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio	[3]	10,438	9,852
30-89 Days Delinquent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio		2,145	2,181
30-89 Days Delinquent [Member] | Credit Card Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan receivables, credit card		1,974	2,038
30-89 Days Delinquent [Member] | Total Other Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio		171	143
30-89 Days Delinquent [Member] | Total Other Loans [Member] | Personal Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan receivables, originated in current fiscal year		13
Loan receivables, originated in fiscal year before current fiscal year		55	26
Loan receivables, originated in two years before current fiscal year		38	44
Loan receivables, originated in three years before current fiscal year		14	20
Loan receivables, originated in four years before current fiscal year		4	7
Loan receivables, originated prior to more than five years before current fiscal year		3	7
Loan portfolio		127	104
90 or More Days Delinquent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio		1,960	1,975
90 or More Days Delinquent [Member] | Credit Card Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan receivables, credit card		1,883	1,917
90 or More Days Delinquent [Member] | Total Other Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio		77	58
90 or More Days Delinquent [Member] | Total Other Loans [Member] | Personal Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan receivables, originated in current fiscal year		3
Loan receivables, originated in fiscal year before current fiscal year		19	8
Loan receivables, originated in two years before current fiscal year		15	16
Loan receivables, originated in three years before current fiscal year		6	8
Loan receivables, originated in four years before current fiscal year		1	2
Loan receivables, originated prior to more than five years before current fiscal year		3	5
Loan portfolio		47	39
Total Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio		4,105	4,156
Total Past Due [Member] | Credit Card Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan receivables, credit card		3,857	3,955
Total Past Due [Member] | Total Other Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan portfolio		248	201
Total Past Due [Member] | Total Other Loans [Member] | Personal Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loan receivables, originated in current fiscal year		16
Loan receivables, originated in fiscal year before current fiscal year		74	34
Loan receivables, originated in two years before current fiscal year		53	60
Loan receivables, originated in three years before current fiscal year		20	28
Loan receivables, originated in four years before current fiscal year		5	9
Loan receivables, originated prior to more than five years before current fiscal year		6	12
Loan portfolio		$ 174	$ 143
[1] Amounts include carrying values of $11.7 billion and $14.8 billion underlying investors' interest in trust debt at September 30, 2024 and December 31, 2023, respectively, and $16.9 billion and $15.6 billion in seller's interest at September 30, 2024 and December 31, 2023, respectively. See Note 4: Credit Card and Private Student Loan Securitization Activities for additional information. Accrued interest receivable on private student, personal and other loans, which is presented as part of other assets in the Company's condensed consolidated statements of financial condition, was $372 million, $74 million and $28 million, respectively, at September 30, 2024 and $522 million, $69 million and $21 million, respectively, at December 31, 2023.

Loan Receivables (Schedule of_2

Loan Receivables (Schedule of Changes in the Allowance for Credit Losses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period	$ 8,481	$ 8,064	$ 9,283	$ 7,374
Provision for credit losses(1)	1,473	1,671	3,749	4,103
Charge-offs	(1,756)	(1,287)	(5,388)	(3,406)
Recoveries	314	217	868	662
Net charge-offs	(1,442)	(1,070)	(4,520)	(2,744)
Allowance for credit losses, balance at end of period	8,512	8,665	8,512	8,665
Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal)		31	40	6
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2022-02
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period				(68)
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2022-02
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period				7,306
Credit Card Loans [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period	7,591	6,525	7,619	5,883
Provision for credit losses(1)	1,327	1,518	4,083	3,752
Charge-offs	(1,629)	(1,171)	(4,926)	(3,101)
Recoveries	297	198	810	602
Net charge-offs	(1,332)	(973)	(4,116)	(2,499)
Allowance for credit losses, balance at end of period	7,586	7,070	7,586	7,070
Credit Card Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2022-02
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period				(66)
Credit Card Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2022-02
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period				5,817
Total Other Loans [Member] | Private Student Loans [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period	0	849	858	839
Provision for credit losses(1)	0	52	(770)	121
Charge-offs	0	(40)	(100)	(111)
Recoveries	0	5	12	17
Net charge-offs	0	(35)	(88)	(94)
Allowance for credit losses, balance at end of period	0	866	0	866
Total Other Loans [Member] | Private Student Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2022-02
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period				0
Total Other Loans [Member] | Private Student Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2022-02
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period				839
Total Other Loans [Member] | Personal Loans [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period	793	622	722	595
Provision for credit losses(1)	111	93	383	211
Charge-offs	(123)	(76)	(353)	(194)
Recoveries	17	14	46	43
Net charge-offs	(106)	(62)	(307)	(151)
Allowance for credit losses, balance at end of period	798	653	798	653
Total Other Loans [Member] | Personal Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2022-02
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period				(2)
Total Other Loans [Member] | Personal Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2022-02
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period				593
Total Other Loans [Member] | Other Loans [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period	97	68	84	57
Provision for credit losses(1)	35	8	53	19
Charge-offs	(4)	0	(9)	0
Recoveries	0	0	0	0
Net charge-offs	(4)	0	(9)	0
Allowance for credit losses, balance at end of period	$ 128	$ 76	$ 128	76
Total Other Loans [Member] | Other Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2022-02
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period				0
Total Other Loans [Member] | Other Loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2022-02
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, balance at beginning of period				$ 57

Loan Receivables (Schedule of N

Loan Receivables (Schedule of Net Charge-offs of Interest and Fee Revenues on Loan Receivables) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Receivables [Abstract]
Interest and fees accrued subsequently charged-off, net of recoveries (recorded as a reduction of interest income)	$ 274	$ 176	$ 831	$ 460
Fees accrued subsequently charged-off, net of recoveries (recorded as a reduction to other income)	$ 61	$ 47	$ 196	$ 134

Loan Receivables (Schedule of G

Loan Receivables (Schedule of Gross Principal Charge-offs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Financing Receivable, Loan Modifications [Line Items]
Financing Receivable, Allowance for Credit Loss, Writeoff	$ 1,756	$ 1,287	$ 5,388	$ 3,406
Credit Card Loans [Member]
Financing Receivable, Loan Modifications [Line Items]
Financing Receivable Revolving Writeoff			4,926	3,101
Financing Receivable, Allowance for Credit Loss, Writeoff	1,629	1,171	4,926	3,101
Total Other Loans [Member] | Personal Loans [Member]
Financing Receivable, Loan Modifications [Line Items]
Gross Principal Charge-off, Year One, Originated, Current Fiscal Year			6
Gross Principal Charge-off, Year Two, Originated, Year Before Current Fiscal Year			125	5
Gross Principal Charge-off, Year Three, Originated, Two Years Before Current Fiscal Year			132	74
Gross Principal Charge-off, Year Four, Originated, Three Years Before Current Fiscal Year			56	58
Gross Principal Charge-off, Year Five, Originated, Four Years Before Current Fiscal Year			18	26
Gross Principal Charge-off Originated More Than Five Years Before Current Fiscal Year			16	31
Financing Receivable, Allowance for Credit Loss, Writeoff	$ 123	$ 76	$ 353	$ 194

Loan Receivables (Schedule of_3

Loan Receivables (Schedule of Delinquent and Non-Accruing Loans) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Loan portfolio		$ 126,993		$ 126,993		$ 128,409
Loan receivables, 90 or more days delinquent and accruing		1,895		1,895		1,921
Loan receivables, total non-accruing	[1]	282		282		261
30-89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio		2,145		2,145		2,181
90 or More Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio		1,960		1,960		1,975
Total Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio		4,105		4,105		4,156
Credit Card Loans [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio	[2],[3]	100,489		100,489		102,259
Loan receivables, 90 or more days delinquent and accruing		1,845		1,845		1,881
Loan receivables, total non-accruing	[1]	191		191		197
Estimated gross interest income that would have been recorded based on original terms		9	$ 11	26	$ 29
Credit Card Loans [Member] | 30-89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Loan receivables, credit card		1,974		1,974		2,038
Credit Card Loans [Member] | 90 or More Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Loan receivables, credit card		1,883		1,883		1,917
Credit Card Loans [Member] | Total Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loan receivables, credit card		3,857		3,857		3,955
Total Other Loans [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio	[4]	18,020		18,020		26,150
Loan receivables, 90 or more days delinquent and accruing		50		50		40
Loan receivables, total non-accruing	[1]	91		91		64
Total Other Loans [Member] | 30-89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio		171		171		143
Total Other Loans [Member] | 90 or More Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio		77		77		58
Total Other Loans [Member] | Total Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio		248		248		201
Total Other Loans [Member] | Personal Loans [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio	[4]	10,438		10,438		9,852
Loan receivables, 90 or more days delinquent and accruing		45		45		37
Loan receivables, total non-accruing	[1]	12		12		11
Total Other Loans [Member] | Personal Loans [Member] | 30-89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio		127		127		104
Total Other Loans [Member] | Personal Loans [Member] | 90 or More Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio		47		47		39
Total Other Loans [Member] | Personal Loans [Member] | Total Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio		174		174		143
Total Other Loans [Member] | Other Loans [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio	[4]	7,582		7,582		5,946
Loan receivables, 90 or more days delinquent and accruing		5		5		3
Loan receivables, total non-accruing	[1]	79		79		53
Total Other Loans [Member] | Other Loans [Member] | 30-89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio		44		44		39
Total Other Loans [Member] | Other Loans [Member] | 90 or More Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio		30		30		19
Total Other Loans [Member] | Other Loans [Member] | Total Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loan portfolio		$ 74		$ 74		$ 58
[1] The Company estimates that the gross interest income that would have been recorded under the original terms of non-accruing credit card loans was $9 million and $11 million for the three months ended September 30, 2024 and 2023, respectively, and $26 million and $29 million for the nine months ended September 30, 2024 and 2023, respectively. The Company does not separately track the amount of gross interest income that would have been recorded under the original terms of loans. Instead, the Company estimated this amount based on customers' current balances and most recent interest rates. Amounts include carrying values of $11.7 billion and $14.8 billion underlying investors' interest in trust debt at September 30, 2024 and December 31, 2023, respectively, and $16.9 billion and $15.6 billion in seller's interest at September 30, 2024 and December 31, 2023, respectively. See Note 4: Credit Card and Private Student Loan Securitization Activities for additional information. Accrued interest receivable on private student, personal and other loans, which is presented as part of other assets in the Company's condensed consolidated statements of financial condition, was $372 million, $74 million and $28 million, respectively, at September 30, 2024 and $522 million, $69 million and $21 million, respectively, at December 31, 2023.

Loan Receivables (Schedule of_4

Loan Receivables (Schedule of Loans That Entered a Modification Program During the Period) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Credit Card Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Troubled Debt Restructuring, Postmodification	[1]	$ 1,028	$ 685	$ 2,619	$ 1,712
Financing Receivable, Modified in Period, to Total Financing Receivables, Percentage	[1]	1.02%	0.70%	2.61%	1.76%
Financing Receivable, Revolving, Converted to Term Loan During Period		$ 191	$ 120	$ 487	$ 302
Credit Card Loans [Member] | Contractual Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Troubled Debt Restructuring, Postmodification	[1]	1,028	685	2,619	1,712
Total Other Loans [Member] | Personal Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Troubled Debt Restructuring, Postmodification		$ 59	$ 43	$ 150	$ 102
Financing Receivable, Modified in Period, to Total Financing Receivables, Percentage		0.57%	0.45%	1.44%	1.07%
Total Other Loans [Member] | Personal Loans [Member] | Payment Deferral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Troubled Debt Restructuring, Postmodification		$ 5	$ 4	$ 11	$ 8
Total Other Loans [Member] | Personal Loans [Member] | Extended Maturity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Troubled Debt Restructuring, Postmodification		11	9	30	24
Total Other Loans [Member] | Personal Loans [Member] | InterestRateReductionandPaymentDeferral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Troubled Debt Restructuring, Postmodification		31	21	75	48
Total Other Loans [Member] | Personal Loans [Member] | Extended Maturity and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Troubled Debt Restructuring, Postmodification		$ 12	$ 9	$ 34	$ 22
[1]Accounts that entered a credit card loan modification program include $191 million and $487 million that were converted from revolving line-of-credit arrangements to term loans during the three and nine months ended September 30, 2024, respectively. Accounts that entered a credit card loan modification program include $120 million and $302 million that were converted from revolving line-of-credit arrangements to term loans during the three and nine months ended September 30, 2023, respectively.

Loan Receivables (Schedule of_5

Loan Receivables (Schedule of Loan Modification Effects) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Credit Card Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	14.47%	13.84%	14.45%	13.68%
Interest and fees forgiven due to loan modification program	$ 58	$ 30	$ 160	$ 77
Credit Card Loans [Member] | Principal forgiven due to loan modification program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal forgiven due to loan modification program	$ 62	$ 35	$ 166	$ 81
Total Other Loans [Member] | Personal Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	14.01%	12.30%	13.62%	12.01%
Financing Receivable, Modified, Weighted Average Term Increase from Modification	39 months	38 months	40 months	38 months
Total Other Loans [Member] | Personal Loans [Member] | Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Payment delay duration (in months)	6 months	6 months	6 months	6 months
Total Other Loans [Member] | Personal Loans [Member] | Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Payment delay duration (in months)	12 months	12 months	12 months	12 months

Loan Receivables (Schedule of_6

Loan Receivables (Schedule of Delinquent Loans Receivables Aging) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Financial Asset, 1 to 29 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Troubled Debt Restructuring	$ 2,824	$ 1,991
30-89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Troubled Debt Restructuring	322	272
90 or More Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Troubled Debt Restructuring	228	200
Credit Card Loans [Member] | Financial Asset, 1 to 29 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Troubled Debt Restructuring	2,677	1,882
Credit Card Loans [Member] | 30-89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Troubled Debt Restructuring	293	252
Credit Card Loans [Member] | 90 or More Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Troubled Debt Restructuring	222	196
Total Other Loans [Member] | Personal Loans [Member] | Financial Asset, 1 to 29 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Troubled Debt Restructuring	147	109
Total Other Loans [Member] | Personal Loans [Member] | 30-89 Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Troubled Debt Restructuring	29	20
Total Other Loans [Member] | Personal Loans [Member] | 90 or More Days Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Troubled Debt Restructuring	$ 6	$ 4

Loan Receivables (Schedule of F

Loan Receivables (Schedule of Financing Receivable, Modified, Subsequent Default) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Credit Card Loans [Member] | Carrying Value [Member]
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount	[1]	$ 263	$ 120	$ 658	$ 203
Credit Card Loans [Member]
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount		186	96	349	124
Credit Card Loans [Member] | Contractual Interest Rate Reduction | Carrying Value [Member]
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount	[1]	263	120	658	203
Credit Card Loans [Member] | Contractual Interest Rate Reduction
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount		186	96	349	124
Total Other Loans [Member] | Personal Loans [Member] | Carrying Value [Member]
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount	[1]	18	7	46	10
Total Other Loans [Member] | Personal Loans [Member]
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount		11	7	17	10
Total Other Loans [Member] | Personal Loans [Member] | Payment Deferral | Carrying Value [Member]
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount	[1]	1		2	1
Total Other Loans [Member] | Personal Loans [Member] | Payment Deferral
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount		1		1	1
Total Other Loans [Member] | Personal Loans [Member] | Extended Maturity | Carrying Value [Member]
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount	[1]	2	1	6	2
Total Other Loans [Member] | Personal Loans [Member] | Extended Maturity
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount		2	1	3	2
Total Other Loans [Member] | Personal Loans [Member] | InterestRateReductionandPaymentDeferral | Carrying Value [Member]
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount	[1]	9	3	23	4
Total Other Loans [Member] | Personal Loans [Member] | InterestRateReductionandPaymentDeferral
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount		3	3	6	4
Total Other Loans [Member] | Personal Loans [Member] | Extended Maturity and Interest Rate Reduction | Carrying Value [Member]
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount	[1]	6	3	15	3
Total Other Loans [Member] | Personal Loans [Member] | Extended Maturity and Interest Rate Reduction
Financing Receivable, Modified, Subsequent Default [Line Items]
Defaulted Amount		$ 5	$ 3	$ 7	$ 3
[1] For purposes of this disclosure, a loan is considered to be defaulted when it is 60 days or more delinquent at month end and has advanced two stages of delinquency subsequent to modification. Loans that entered a modification program in any stage of delinquency but did not experience a further payment default are included in the payment status table above but are not counted as defaulted for purposes of this disclosure.

Credit Card and Private Stude_3

Credit Card and Private Student Loan Securitization Activities (Narrative) (Details)	9 Months Ended
	Sep. 30, 2024 classes
Variable Interest Entity, Primary Beneficiary [Member] | Discover Card Execution Note Trust [Member] | Credit Card Securitization Trusts [Member]
Variable Interest Entity [Line Items]
Number of classes of securities in debt structure (in classes)	4

Credit Card and Private Stude_4

Credit Card and Private Student Loan Securitization Activities (Schedule of Restricted Credit Card Securitized Assets) (Details) - USD ($) $ in Millions		Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Variable Interest Entity [Line Items]
Restricted cash		$ 36		$ 43	$ 39
Loan portfolio		126,993		128,409
Allowance for credit losses allocated to securitized loan receivables		(8,512)	$ (8,481)	(9,283)	$ (8,665)	$ (8,064)	$ (7,374)
Net loan receivables		118,481		119,126
Other assets		5,371		5,858
Total assets		151,615		151,713
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Restricted cash		36		43
Loan portfolio				30,590
Allowance for credit losses allocated to securitized loan receivables		(1,334)		(1,347)
Other assets		4		3
Variable Interest Entity, Primary Beneficiary [Member] | Credit Card Securitization Trusts [Member]
Variable Interest Entity [Line Items]
Restricted cash		29		36
Investors' interests held by third-party investors		9,250		11,725
Investors' interests held by wholly-owned subsidiaries of Discover Bank		2,459		3,117
Seller's interest		16,934		15,598
Loan portfolio	[1]	28,643		30,440
Allowance for credit losses allocated to securitized loan receivables	[1]	(1,334)		(1,347)
Net loan receivables		27,309		29,093
Other assets		3		2
Total assets		$ 27,341		$ 29,131
[1] The Company maintains its allowance for credit losses at an amount equal to lifetime expected credit losses associated with all loan receivables, which includes all loan receivables in the trusts. Therefore, the credit risk associated with the transferred receivables is fully reflected on the Company's statements of financial condition in accordance with GAAP.

Deposits (Schedule of Certifica

Deposits (Schedule of Certificates of Deposit Maturities) (Details) $ in Millions	Sep. 30, 2024 USD ($)
Deposits [Abstract]
2024	$ 10,208
2025	23,052
2026	4,914
2027	4,521
2028	2,209
Thereafter	1,172
Total	$ 46,076

Long-Term Borrowings (Narrative

Long-Term Borrowings (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Federal Home Loan Bank, advances, general debt obligations, maximum amount available	$ 4,900	$ 3,600
Federal Home Loan Bank advances	1,000	1,000
Discover Card Master Trust I and Discover Card Execution Note Trust [Member] | Securitized Debt [Member]
Debt Instrument [Line Items]
Total commitment of secured credit facilities	3,500	3,500
Total used commitment of secured credit facilities	$ 750	$ 750

Long-Term Borrowings (Schedule

Long-Term Borrowings (Schedule of Long-Term Borrowings and Weighted Average Interest Rates) (Details) $ in Millions		9 Months Ended
		Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Debt Instrument [Line Items]
Long-term borrowings (in dollars)		$ 17,427	$ 20,581
Securitized Debt [Member] | Discover Card Master Trust I and Discover Card Execution Note Trust [Member]
Debt Instrument [Line Items]
Long-term borrowings (in dollars)		$ 8,503	10,928
Securitized Debt [Member] | Discover Card Master Trust I and Discover Card Execution Note Trust [Member] | Fixed-Rate Asset-Backed Securities [Member]
Debt Instrument [Line Items]
Weighted-average interest rate	[1]	3.55%
Long-term borrowings (in dollars)	[1]	$ 8,503	10,003
Securitized Debt [Member] | Discover Card Master Trust I and Discover Card Execution Note Trust [Member] | Fixed-Rate Asset-Backed Securities [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest rate	[1]	1.03%
Securitized Debt [Member] | Discover Card Master Trust I and Discover Card Execution Note Trust [Member] | Fixed-Rate Asset-Backed Securities [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest rate	[1]	5.03%
Securitized Debt [Member] | Discover Card Master Trust I and Discover Card Execution Note Trust [Member] | Floating-Rate Asset-Backed Securities [Member]
Debt Instrument [Line Items]
Weighted-average interest rate		0%
Long-term borrowings (in dollars)		$ 0	925
Securitized Debt [Member] | Discover Card Master Trust I and Discover Card Execution Note Trust [Member] | Floating-Rate Asset-Backed Securities [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest rate		0%
Securitized Debt [Member] | Discover Card Master Trust I and Discover Card Execution Note Trust [Member] | Floating-Rate Asset-Backed Securities [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest rate		0%
Securitized Debt [Member] | Student Loan Trust [Member]
Debt Instrument [Line Items]
Long-term borrowings (in dollars)		$ 54	65
Securitized Debt [Member] | Student Loan Trust [Member] | Floating-Rate Asset-Backed Securities [Member]
Debt Instrument [Line Items]
Interest rate	[2]	9%
Weighted-average interest rate	[3],[4]	9%
Long-term borrowings (in dollars)	[3],[4]	$ 54	65
Interest rate terms		Prime rate + 100 basis points
Basis spread on variable rate		1%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]		Prime Rate [Member]
Securitized Debt [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Debt Instrument [Line Items]
Long-term borrowings (in dollars)		$ 8,557	10,993
Corporate Debt Securities [Member] | Parent Company [Member] | Fixed-Rate Senior Notes [Member]
Debt Instrument [Line Items]
Weighted-average interest rate		4.68%
Long-term borrowings (in dollars)		$ 3,339	3,336
Corporate Debt Securities [Member] | Parent Company [Member] | Fixed-Rate Senior Notes [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest rate		3.75%
Corporate Debt Securities [Member] | Parent Company [Member] | Fixed-Rate Senior Notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest rate		6.70%
Corporate Debt Securities [Member] | Parent Company [Member] | Fixed-Rate Retail Notes [Member]
Debt Instrument [Line Items]
Weighted-average interest rate		3.82%
Long-term borrowings (in dollars)		$ 138	140
Corporate Debt Securities [Member] | Parent Company [Member] | Fixed-Rate Retail Notes [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest rate		3.25%
Corporate Debt Securities [Member] | Parent Company [Member] | Fixed-Rate Retail Notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest rate		4.40%
Corporate Debt Securities [Member] | Parent Company [Member] | Fixed to Floating-Rate Senior Notes
Debt Instrument [Line Items]
Weighted-average interest rate	[5]	7.96%
Long-term borrowings (in dollars)	[5]	$ 993	993
Interest rate terms		SOFR + 3.370%
Debt Instrument Basis Spread on Variable Rate 1, Rate To Be Used in Future Periods		0.0337
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Corporate Debt Securities [Member] | Parent Company [Member] | Fixed to Floating-Rate Senior Notes | Minimum [Member]
Debt Instrument [Line Items]
Interest rate		7.96%
Corporate Debt Securities [Member] | Parent Company [Member] | Fixed to Floating-Rate Senior Notes | Maximum [Member]
Debt Instrument [Line Items]
Interest rate		7.96%
Senior Notes [Member] | Discover Bank [Member] | Fixed-Rate Senior Bank Notes [Member]
Debt Instrument [Line Items]
Weighted-average interest rate	[1]	3.82%
Long-term borrowings (in dollars)	[1]	$ 2,846	3,571
Senior Notes [Member] | Discover Bank [Member] | Fixed-Rate Senior Bank Notes [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest rate	[1]	2.70%
Senior Notes [Member] | Discover Bank [Member] | Fixed-Rate Senior Bank Notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest rate	[1]	4.65%
Subordinated Debt [Member] | Discover Bank [Member] | Fixed-Rate Subordinated Bank Notes
Debt Instrument [Line Items]
Weighted-average interest rate		5.97%
Long-term borrowings (in dollars)		$ 506	500
Subordinated Debt [Member] | Discover Bank [Member] | Fixed-Rate Subordinated Bank Notes | Minimum [Member]
Debt Instrument [Line Items]
Interest rate		5.97%
Subordinated Debt [Member] | Discover Bank [Member] | Fixed-Rate Subordinated Bank Notes | Maximum [Member]
Debt Instrument [Line Items]
Interest rate	[1]	5.97%
Federal Home Loan Bank Advances | Discover Bank [Member] | Minimum [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		0.16%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Federal Home Loan Bank Advances | Discover Bank [Member] | Maximum [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		0.26%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Federal Home Loan Bank Advances | Discover Bank [Member] | Fixed-Rate FHLB Advance
Debt Instrument [Line Items]
Weighted-average interest rate		4.82%
Long-term borrowings (in dollars)		$ 523	523
Federal Home Loan Bank Advances | Discover Bank [Member] | Fixed-Rate FHLB Advance | Minimum [Member]
Debt Instrument [Line Items]
Interest rate		4.77%
Federal Home Loan Bank Advances | Discover Bank [Member] | Fixed-Rate FHLB Advance | Maximum [Member]
Debt Instrument [Line Items]
Interest rate		4.82%
Federal Home Loan Bank Advances | Discover Bank [Member] | Floating-Rate FHLB Advance
Debt Instrument [Line Items]
Weighted-average interest rate	[2]	5.09%
Long-term borrowings (in dollars)	[2]	$ 525	$ 525
Interest rate terms		SOFR plus a spread ranging from 16 to 26 basis points
Federal Home Loan Bank Advances | Discover Bank [Member] | Floating-Rate FHLB Advance | Minimum [Member]
Debt Instrument [Line Items]
Interest rate		4.99%
Federal Home Loan Bank Advances | Discover Bank [Member] | Floating-Rate FHLB Advance | Maximum [Member]
Debt Instrument [Line Items]
Interest rate		5.09%
[1] The Company uses interest rate swaps to hedge portions of these long-term borrowings against changes in fair value attributable to changes in the applicable benchmark interest rates. The use of these interest rate swaps impacts the carrying value of the debt. See Note 15: Derivatives and Hedging Activities. (5) The floating-rate FHLB advances include interest rate terms based on SOFR plus a spread ranging from 16 to 26 basis points as of September 30, 2024. Repayment of this debt is dependent upon the timing of principal and interest payments on the underlying private student loans. The date shown represents the final maturity date. The private student loan securitization trust floating-rate asset-backed security includes an issuance with the following interest rate term: Prime rate + 100 basis points as of September 30, 2024.

Long-Term Borrowings (Schedul_2

Long-Term Borrowings (Schedule of Long-Term Borrowings Maturities) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Debt Disclosure [Abstract]
2024	$ 1,025
2025	6,174
2026	4,941
2027	1,002
2028	1,452
Thereafter	2,833
Total	$ 17,427	$ 20,581

Preferred Stock (Schedule of St

Preferred Stock (Schedule of Stock by Class) (Details) - USD ($) $ / shares in Units, $ in Millions				9 Months Ended
		Jun. 22, 2020	Oct. 31, 2017	Sep. 30, 2024	Dec. 31, 2023
Class of Stock [Line Items]
Preferred stock, par or stated value per share				$ 0.01	$ 0.01
Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, depositary shares issued (in number of depositary shares)				1,070,000	1,070,000
Proceeds from issuance of preferred stock, net				$ 1,056	$ 1,056
Preferred Stock [Member] | Series C Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, initial issue date	[1]		Oct. 31, 2017
Preferred stock, liquidation preference per share	[1],[2],[3]			$ 1,000
Preferred stock, redemption price per share	[1],[2],[3]			$ 1,000
Preferred Stock, Dividend Rate, Percentage	[1],[4]			5.50%
Preferred stock, depositary shares issued (in number of depositary shares)	[1]			570,000	570,000
Proceeds from issuance of preferred stock, net	[1]			$ 563	$ 563
Depositary shares represented by one preferred share				100
Preferred stock, par or stated value per share				$ 0.01
Preferred stock, earliest redemption date				Oct. 30, 2027
Redemption period of preferred stock following regulatory capital treatment event				90 days
Preferred Stock [Member] | Series C Preferred Stock [Member] | Three-Month Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Class of Stock [Line Items]
Preferred stock dividend payment rate variable, rate to be used in future periods				0.03338
Preferred Stock [Member] | Series D Preferred Stock
Class of Stock [Line Items]
Preferred stock, initial issue date	[1]	Jun. 22, 2020
Preferred stock, liquidation preference per share	[1],[3],[5]			$ 1,000
Preferred stock, redemption price per share	[1],[3],[5]			$ 1,000
Preferred Stock, Dividend Rate, Percentage	[1],[6]			6.125%
Preferred stock, depositary shares issued (in number of depositary shares)	[1]			500,000	500,000
Proceeds from issuance of preferred stock, net	[1]			$ 493	$ 493
Depositary shares represented by one preferred share				100
Preferred stock, par or stated value per share				$ 0.01
Redemption period of preferred stock following regulatory capital treatment event				90 days
Dividend rate reset				5 years
Preferred Stock [Member] | Series D Preferred Stock | Five-Year Treasury Rate
Class of Stock [Line Items]
Preferred stock dividend payment rate variable, rate to be used in future periods				0.05783
[1] Issued as depositary shares, each representing 1/100 th interest in a share of the corresponding series of preferred stock. Each preferred share has a par value of $0.01. Redeemable at the Company’s option, subject to regulatory approval, either (i) in whole or in part on any dividend payment date on or after October 30, 2027, or (ii) in whole but not in part, at any time within 90 days following a regulatory capital treatment event (as defined in the certificate of designations for the Series C preferred stock). Redeemable at the redemption price plus declared and unpaid dividends. Any dividends declared are payable semi-annually in arrears at a rate of 5.500% per annum until October 30, 2027. Thereafter, dividends declared will be payable quarterly in arrears at a floating rate equal to 3-month Term SOFR plus a spread of 3.338% per annum. Redeemable at the Company’s option, subject to regulatory approval, either (i) in whole or in part during the three-month period prior to, and including, each reset date (as defined in the certificate of designations for the Series D preferred stock) or (ii) in whole but not in part, at any time within 90 days following a regulatory capital treatment event (as defined in the certificate of designations for the Series D Preferred Stock). Any dividends declared are payable semi-annually in arrears at a rate of 6.125% per annum until September 23, 2025, after which the dividend rate will reset every 5 years to a fixed annual rate equal to the 5-year Treasury plus a spread of 5.783%.

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Schedule of Changes in Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax, balance at beginning of period			$ (225)
Net change in accumulated other comprehensive income (loss), net of tax	$ 415	$ (103)	242	$ (234)
Accumulated other comprehensive income (loss), net of tax, balance at end of period	17		17
Unrealized Gains (Losses) on Available-for-Sale Investment Securities, Net of Tax [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax, balance at beginning of period	(148)	(195)	(37)	(136)
Net change in accumulated other comprehensive income (loss), net of tax	239	(83)	128	(142)
Accumulated other comprehensive income (loss), net of tax, balance at end of period	91	(278)	91	(278)
Gains (Losses) on Cash Flow Hedges, Net of Tax [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax, balance at beginning of period	(70)	(86)	(8)	(14)
Net change in accumulated other comprehensive income (loss), net of tax	176	(20)	114	(92)
Accumulated other comprehensive income (loss), net of tax, balance at end of period	106	(106)	106	(106)
Gains (Losses) on Pension Plan, Net of Tax [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax, balance at beginning of period	(180)	(189)	(180)	(189)
Net change in accumulated other comprehensive income (loss), net of tax	0	0	0	0
Accumulated other comprehensive income (loss), net of tax, balance at end of period	(180)	(189)	(180)	(189)
Accumulated Other Comprehensive (Loss) Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax, balance at beginning of period	(398)	(470)	(225)	(339)
Net change in accumulated other comprehensive income (loss), net of tax	415	(103)	242	(234)
Accumulated other comprehensive income (loss), net of tax, balance at end of period	$ 17	$ (573)	$ 17	$ (573)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Schedule of Other Comprehensive Income Before Reclassifications and Amounts Reclassified from AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Available-for-sale investment securities, net unrealized holding gains (losses) arising during the period, before tax	$ 316	$ (111)	$ 169	$ (188)
Available-for-sale investment securities, net unrealized holding gains (losses) arising during the period, tax benefit (expense)	(77)	28	(41)	46
Available-for-sale investment securities, net unrealized holding gains (losses) arising during the period, net of tax	239	(83)	128	(142)
Available-for-sale investment securities, net change, before tax	316	(111)	169	(188)
Available-for-sale investment securities, net change, tax benefit (expense)	(77)	28	(41)	46
Available-for-sale investment securities, net change, net of tax	239	(83)	128	(142)
Cash flow hedges, net unrealized gains (losses) arising during the period, before tax	200	(55)	38	(172)
Cash flow hedges, net unrealized gains (losses) arising during the period, tax benefit (expense)	(48)	13	(9)	42
Cash flow hedges, net unrealized gains (losses) arising during the period, net of tax	152	(42)	29	(130)
Cash flow hedges, amounts reclassified from AOCI, before tax	31	29	112	50
Cash flow hedges, amounts reclassified from AOCI, tax benefit (expense)	(7)	(7)	(27)	(12)
Cash flow hedges, amounts reclassified from AOCI, net of tax	24	22	85	38
Cash flow hedges, net change, before tax	231	(26)	150	(122)
Cash flow hedges, net change, tax benefit (expense)	(55)	6	(36)	30
Cash flow hedges, net change, net of tax	$ 176	$ (20)	$ 114	$ (92)

Income Taxes (Schedule of Effec

Income Taxes (Schedule of Effective Income Tax Rate Calculation) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income before income taxes	$ 1,192	$ 761	$ 4,372	$ 3,154
Income tax expense	$ 322	$ 175	$ 1,128	$ 724
Effective income tax rate (in percent)	27%	23%	25.80%	23%

Earnings Per Share (Schedule of

Earnings Per Share (Schedule of Basic and Diluted EPS ) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator:
Net income	$ 870	$ 586	$ 3,244	$ 2,430
Preferred stock dividends	(31)	(31)	(62)	(62)
Net income available to common stockholders	839	555	3,182	2,368
Income allocated to participating securities	(5)	(5)	(20)	(17)
Net income allocated to common stockholders	834	550	3,162	2,351
Net income (loss) available to common stockholders, diluted	$ 834	$ 550	$ 3,162	$ 2,351
Denominator:
Weighted-average shares of common stock outstanding	251	250	251	255
Weighted-average shares of common stock outstanding and common stock equivalents	251	250	251	255
Basic earnings per common share (in dollars per share)	$ 3.32	$ 2.21	$ 12.61	$ 9.23
Diluted earnings per common share (in dollars per share)	$ 3.32	$ 2.21	$ 12.61	$ 9.22

Capital Adequacy (Schedule of M

Capital Adequacy (Schedule of Minimum and Well-Capitalized Requirements) (Details) $ in Millions		Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Parent Company [Member]
Compliance with Regulatory Capital Requirements [Line Items]
Total capital to risk-weighted assets, actual amount		$ 19,379	$ 17,399
Total capital to risk-weighted assets, actual ratio (in percent)	[1]	0.149	0.132
Total capital to risk-weighted assets, minimum capital requirements, amount		$ 10,407	$ 10,509
Total capital to risk-weighted assets, minimum capital requirements, ratio (in percent)		0.080	0.080
Total capital to risk-weighted assets, capital requirements to be classified as well-capitalized, amount	[2]	$ 13,009	$ 13,137
Total capital to risk-weighted assets, capital requirements to be classified as well-capitalized, ratio (in percent)	[2]	0.100	0.100
Tier I capital to risk-weighted assets, actual amount		$ 17,373	$ 15,279
Tier I capital to risk-weighted assets, actual ratio (in percent)	[1]	0.134	0.116
Tier I capital to risk-weighted assets, minimum capital requirements, amount		$ 7,805	$ 7,882
Tier I capital to risk-weighted assets, minimum capital requirements, ratio (in percent)		0.060	0.060
Tier I capital to risk-weighted assets, capital requirements to be classified as well-capitalized, amount	[2]	$ 7,805	$ 7,882
Tier I capital to risk-weighted assets, capital requirements to be classified as well-capitalized, ratio (in percent)	[2]	0.060	0.060
Tier I capital to average assets, actual amount		$ 17,373	$ 15,279
Tier I capital to average assets, actual ratio (in percent)	[1]	0.114	0.103
Tier I capital to average assets, minimum capital requirements, amount		$ 6,080	$ 5,915
Tier I capital to average assets, minimum capital requirements, ratio (in percent)		0.040	0.040
CET1 capital to risk-weighted assets, actual amount		$ 16,317	$ 14,223
CET1 capital to risk-weighted assets, actual ratio (in percent)	[1]	0.125	0.108
CET1 capital to risk-weighted assets, minimum capital requirements, amount		$ 5,854	$ 5,911
CET1 capital to risk-weighted assets, minimum capital requirements, ratio (in percent)		4.50%	4.50%
Discover Bank [Member]
Compliance with Regulatory Capital Requirements [Line Items]
Total capital to risk-weighted assets, actual amount		$ 17,611	$ 16,409
Total capital to risk-weighted assets, actual ratio (in percent)	[1]	0.137	0.127
Total capital to risk-weighted assets, minimum capital requirements, amount		$ 10,266	$ 10,381
Total capital to risk-weighted assets, minimum capital requirements, ratio (in percent)		0.080	0.080
Total capital to risk-weighted assets, capital requirements to be classified as well-capitalized, amount	[2]	$ 12,832	$ 12,976
Total capital to risk-weighted assets, capital requirements to be classified as well-capitalized, ratio (in percent)	[2]	0.100	0.100
Tier I capital to risk-weighted assets, actual amount		$ 14,877	$ 13,459
Tier I capital to risk-weighted assets, actual ratio (in percent)	[1]	0.116	0.104
Tier I capital to risk-weighted assets, minimum capital requirements, amount		$ 7,699	$ 7,786
Tier I capital to risk-weighted assets, minimum capital requirements, ratio (in percent)		0.060	0.060
Tier I capital to risk-weighted assets, capital requirements to be classified as well-capitalized, amount	[2]	$ 10,266	$ 10,381
Tier I capital to risk-weighted assets, capital requirements to be classified as well-capitalized, ratio (in percent)	[2]	0.080	0.080
Tier I capital to average assets, actual amount		$ 14,877	$ 13,459
Tier I capital to average assets, actual ratio (in percent)	[1]	0.099	0.092
Tier I capital to average assets, minimum capital requirements, amount		$ 6,012	$ 5,833
Tier I capital to average assets, minimum capital requirements, ratio (in percent)		0.040	0.040
Tier I capital to average assets, capital requirements to be classified as well-capitalized, amount	[2]	$ 7,515	$ 7,292
Tier I capital to average assets, capital requirements to be classified as well-capitalized, ratio (in percent)	[2]	0.050	0.050
CET1 capital to risk-weighted assets, actual amount		$ 14,877	$ 13,459
CET1 capital to risk-weighted assets, actual ratio (in percent)	[1]	0.116	0.104
CET1 capital to risk-weighted assets, minimum capital requirements, amount		$ 5,775	$ 5,839
CET1 capital to risk-weighted assets, minimum capital requirements, ratio (in percent)		4.50%	4.50%
CET1 capital to risk-weighted assets, capital requirements to be classified as well-capitalized, amount	[2]	$ 8,341	$ 8,435
CET1 capital to risk-weighted assets, capital requirements to be classified as well-capitalized, ratio (in percent)	[2]	6.50%	6.50%
[1] Capital ratios are calculated based on the Basel III standardized approach rules, subject to applicable transition provisions, including CECL transition provisions. The Basel III rules do not establish well-capitalized thresholds for these measures for bank holding companies. Existing well-capitalized thresholds established in the Federal Reserve's Regulation Y have been included where available.

Commitments, Contingencies an_3

Commitments, Contingencies and Guarantees (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Commitments, Contingencies and Guarantees [Line Items]
Off-Balance-Sheet, Credit Loss, Liability	$ 0
Contingent liabilities related to equity method investments	0	$ 0
Commitments to Extend Credit [Member]
Commitments, Contingencies and Guarantees [Line Items]
Unused commitments to extend credit for loans	233,700
CounterpartySettlementGuarantees
Commitments, Contingencies and Guarantees [Line Items]
Guarantor obligations, maximum exposure, undiscounted	120
Merchant Chargeback Guarantees [Member]
Commitments, Contingencies and Guarantees [Line Items]
Escrow deposits and settlement withholdings	$ 9	$ 10

Commitments, Contingencies an_4

Commitments, Contingencies and Guarantees (Schedule of Maximum Potential Counterparty Exposures Related to Settlement Guarantees and Merchant Chargeback Guarantee) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Merchant Chargeback Guarantees [Member]
Loss Contingencies [Line Items]
Aggregate sales transaction volume	[1]	$ 61,166	$ 65,490	$ 184,384	$ 192,173
[1] Represents transactions processed on the Discover Network for which a potential liability exists that, in aggregate, can differ from credit card sales volume.

Litigation and Regulatory Mat_3

Litigation and Regulatory Matters (Narrative) (Details) - USD ($) $ in Millions		9 Months Ended
	Dec. 22, 2020	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023
Loss Contingencies [Line Items]
Loss Contingency Accrual, Provision for Other Settlement Concessions		$ 76
Card Product Misclassification Merchant and Merchant acquirers
Loss Contingencies [Line Items]
Accrued Liabilities and Other Liabilities		1,201		$ 1,159
Accrued Professional Fees			$ 26
Loss Contingency Accrual, Provision for Refund of Overcharges		0
Loss Contingency Accrual, Provision for Interest on Overcharges		42
Loss Contingency Accrual, Payments		76
Card Product Misclassification Regulator penalties
Loss Contingencies [Line Items]
Accrued Liabilities and Other Liabilities		90	$ 200
Unfavorable Regulatory Action [Member] | Consumer Financial Protection Bureau Consent Order [Member]
Loss Contingencies [Line Items]
Amount of civil money penalty for consent order	$ 25
Maximum [Member] | Pending and Threatened Litigation [Member]
Loss Contingencies [Line Items]
Loss contingency, range of possible loss, portion not accrued		$ 70
Minimum [Member] | Unfavorable Regulatory Action [Member] | Consumer Financial Protection Bureau Consent Order [Member]
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss	$ 10

Litigation and Regulatory Mat_4

Litigation and Regulatory Matters (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Card Product Misclassification Merchant and Merchant acquirers
Loss Contingencies [Line Items]
Accrued Liabilities and Other Liabilities	$ 1,201	$ 1,159

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions		Sep. 30, 2024		Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value	[1]	$ 14,590		$ 13,402
US Treasury and Government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value	[1]	14,185		12,937
Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value	[1]	405	[2]	465
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value		14,590		13,402
Equity Securities, FV-NI				1
Fair Value, Recurring [Member] | Interest Rate Swaps [Member] | Cash Flow Hedging [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities, fair value	[3]	18
Derivative financial instruments, assets, fair value				2
Fair Value, Recurring [Member] | Interest Rate Swaps [Member] | Fair Value Hedging [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities, fair value		19
Derivative financial instruments, assets, fair value				2
Fair Value, Recurring [Member] | US Treasury and Government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value		14,185		12,937
Fair Value, Recurring [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value		405		465
Fair Value, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value		14,177		12,928
Equity Securities, FV-NI				1
Fair Value, Recurring [Member] | Level 1 [Member] | Interest Rate Swaps [Member] | Cash Flow Hedging [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities, fair value	[3]	0
Derivative financial instruments, assets, fair value				0
Fair Value, Recurring [Member] | Level 1 [Member] | Interest Rate Swaps [Member] | Fair Value Hedging [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities, fair value		0
Derivative financial instruments, assets, fair value				0
Fair Value, Recurring [Member] | Level 1 [Member] | US Treasury and Government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value		14,177		12,928
Fair Value, Recurring [Member] | Level 1 [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value		0		0
Fair Value, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value		413		474
Equity Securities, FV-NI				0
Fair Value, Recurring [Member] | Level 2 [Member] | Interest Rate Swaps [Member] | Cash Flow Hedging [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities, fair value	[3]	18
Derivative financial instruments, assets, fair value				2
Fair Value, Recurring [Member] | Level 2 [Member] | Interest Rate Swaps [Member] | Fair Value Hedging [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities, fair value		19
Derivative financial instruments, assets, fair value				2
Fair Value, Recurring [Member] | Level 2 [Member] | US Treasury and Government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value		8		9
Fair Value, Recurring [Member] | Level 2 [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value		405		465
Fair Value, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value		0		0
Equity Securities, FV-NI				0
Fair Value, Recurring [Member] | Level 3 [Member] | Interest Rate Swaps [Member] | Cash Flow Hedging [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities, fair value	[3]	0
Derivative financial instruments, assets, fair value				0
Fair Value, Recurring [Member] | Level 3 [Member] | Interest Rate Swaps [Member] | Fair Value Hedging [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities, fair value		0
Derivative financial instruments, assets, fair value				0
Fair Value, Recurring [Member] | Level 3 [Member] | US Treasury and Government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value		0		0
Fair Value, Recurring [Member] | Level 3 [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities, fair value		$ 0		$ 0
[1] Available-for-sale investment securities are reported at fair value. Maturities of RMBS are reflective of the contractual maturities of the investment. Derivative instrument carrying values in an asset or liability position are presented as part of other assets or accrued expenses and other liabilities, respectively, in the Company's condensed consolidated statements of financial condition.

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill and Intangible Asset Impairment	$ 0	$ 0	$ 0	$ 0
Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities, par value	$ 412,000,000		$ 412,000,000
Available for sale securities, weighted average coupon rate (in percent)	4.12%		4.12%
Available for sale securities, weighted average remaining maturity (in years)			4 years

Fair Value Measurements (Sche_2

Fair Value Measurements (Schedule of Financial Instruments Measured at Other Than Fair Value) (Details) - USD ($) $ in Millions		Sep. 30, 2024		Dec. 31, 2023
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		$ 260		$ 234
Net loan receivables		126,431		126,940
Cash and cash equivalents	[1]	10,787		11,685
Restricted cash	[1]	36		43
Other Short-term Investments Fair Value Disclosure		735
Accrued interest receivables	[1],[2]	1,324	[3]	1,450
Time deposits	[4]	46,338		45,333
Short-term debt, fair value		750		750
Long-term borrowings		17,545		20,304
Accrued interest payables	[1],[2]	396		421
Estimated Fair Value [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		8,502		10,835
Estimated Fair Value [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		9,043		9,469
Estimated Fair Value [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		260		234
Estimated Fair Value [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		0		0
Net loan receivables		0		0
Cash and cash equivalents	[1]	10,787		11,685
Restricted cash	[1]	36		43
Other Short-term Investments Fair Value Disclosure		735
Accrued interest receivables	[1],[2]	0	[3]	0
Time deposits	[4]	0		0
Short-term debt, fair value		0		0
Long-term borrowings		0		0
Accrued interest payables	[1],[2]	0		0
Estimated Fair Value [Member] | Level 1 [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		0		0
Estimated Fair Value [Member] | Level 1 [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		0		0
Estimated Fair Value [Member] | Level 1 [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		0		0
Estimated Fair Value [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		260		234
Net loan receivables				0
Cash and cash equivalents	[1]	0		0
Restricted cash	[1]	0		0
Other Short-term Investments Fair Value Disclosure		0
Accrued interest receivables	[1],[2]	1,324	[3]	1,450
Time deposits	[4]	46,338		45,333
Short-term debt, fair value		750		750
Long-term borrowings		17,491		20,239
Accrued interest payables	[1],[2]	396		421
Estimated Fair Value [Member] | Level 2 [Member] | Total Other Loans [Member] | Private Student Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net loan receivables		8,878
Estimated Fair Value [Member] | Level 2 [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		8,448		10,770
Estimated Fair Value [Member] | Level 2 [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		9,043		9,469
Estimated Fair Value [Member] | Level 2 [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		260		234
Estimated Fair Value [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		0		0
Net loan receivables		117,553		126,940
Cash and cash equivalents	[1]	0		0
Restricted cash	[1]	0		0
Other Short-term Investments Fair Value Disclosure		0
Accrued interest receivables	[1],[2]	0	[3]	0
Time deposits	[4]	0		0
Short-term debt, fair value		0		0
Long-term borrowings		54		65
Accrued interest payables	[1],[2]	0		0
Estimated Fair Value [Member] | Level 3 [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		54		65
Estimated Fair Value [Member] | Level 3 [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		0		0
Estimated Fair Value [Member] | Level 3 [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		0		0
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		275		253
Net loan receivables		118,481		119,126
Cash and cash equivalents	[1]	10,787		11,685
Restricted cash	[1]	36		43
Other Short-term Investments Fair Value Disclosure		735
Accrued interest receivables	[1],[2]	1,309	[3]	1,450
Time deposits	[4]	46,076		45,240
Short-term debt, fair value		750		750
Long-term borrowings		17,427		20,581
Accrued interest payables	[1],[2]	396		421
Carrying Value [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		8,557		10,993
Carrying Value [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings		8,870		9,588
Carrying Value [Member] | Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		275		253
Held-to-maturity investment securities	[5]	260		234
Residential Mortgage-Backed Securities - Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities	[5],[6]	$ 260	[7]	$ 234
[1] The carrying values of these assets and liabilities approximate fair value due to their short-term nature, except as otherwise indicated. Accrued interest receivable and payable carrying values are presented as part of other assets and accrued expenses and other liabilities, respectively, in the Company's condensed consolidated statements of financial condition. The fair value includes a premium associated with interest to be capitalized on private student loans held-for-sale based on the terms of the executed purchase agreement. Excludes deposits without contractually defined maturities for all periods presented. Held-to-maturity investment securities are reported at amortized cost. Amounts represent residential mortgage-backed securities ("RMBS") that were classified as held-to-maturity as they were entered into as a part of the Company's community reinvestment initiatives. Maturities of RMBS are reflective of the contractual maturities of the investment.

Derivatives and Hedging Activ_3

Derivatives and Hedging Activities (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Interest Income
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified within twelve months	$ (28)
Financing Receivable [Member]
Derivative [Line Items]
Initial maximum period for cash flow hedges (in years)	5 years	5 years

Derivatives and Hedging Activ_4

Derivatives and Hedging Activities (Schedule of Fair Value and Outstanding Notional Amounts of Derivative Instruments and Related Collateral Balances) (Details) € in Millions, £ in Millions, $ in Millions, $ in Millions, $ in Millions, ₨ in Billions		Sep. 30, 2024 USD ($) transactions	Sep. 30, 2024 EUR (€) transactions	Sep. 30, 2024 GBP (£) transactions	Sep. 30, 2024 SGD ($) transactions	Sep. 30, 2024 INR (₨) transactions	Dec. 31, 2023 USD ($) transactions		Dec. 31, 2023 EUR (€) transactions	Dec. 31, 2023 GBP (£) transactions	Dec. 31, 2023 SGD ($) transactions	Dec. 31, 2023 INR (₨) transactions	Dec. 31, 2023 AUD ($) transactions
Derivatives, Fair Value [Line Items]
Derivative assets	[1]	$ 0					$ 4	[2]
Derivative liabilities	[1]	37					0	[2]
Collateral held, derivative assets	[3]	0					0	[2]
Collateral posted, derivative liabilities	[3]	(37)					0	[2]
Total net derivative assets		0					4	[2]
Total net derivative liabilities		0					0	[2]
Designated as Hedges [Member] | Cash Flow Hedging [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative, notional amount		$ 15,000					10,650
Derivative, number of outstanding derivative contracts | transactions		20	20	20	20	20
Derivative assets		$ 0					2	[2]
Derivative liabilities		18					0	[2]
Designated as Hedges [Member] | Fair Value Hedging [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative, notional amount		$ 15,371					8,650
Derivative, number of outstanding derivative contracts | transactions		19	19	19	19	19
Derivative assets		$ 0					2	[2]
Derivative liabilities		19					0	[2]
Not Designated as Hedges [Member] | Foreign Exchange Forward [Member]
Derivatives, Fair Value [Line Items]
Derivative, notional amount	[4]	$ 33					29
Derivative, number of outstanding derivative contracts | transactions		6	6	6	6	6
Derivative assets		$ 0					0	[2]
Derivative liabilities		$ 0					0	[2]
Not Designated as Hedges [Member] | Foreign Exchange Forward [Member] | Euro Member Countries, Euro
Derivatives, Fair Value [Line Items]
Derivative, notional amount | €			€ 6						€ 6
Not Designated as Hedges [Member] | Foreign Exchange Forward [Member] | United Kingdom, Pounds
Derivatives, Fair Value [Line Items]
Derivative, notional amount | £				£ 6						£ 6
Not Designated as Hedges [Member] | Foreign Exchange Forward [Member] | Singapore, Dollars
Derivatives, Fair Value [Line Items]
Derivative, notional amount					$ 1						$ 1
Not Designated as Hedges [Member] | Foreign Exchange Forward [Member] | India, Rupees
Derivatives, Fair Value [Line Items]
Derivative, notional amount | ₨						₨ 1.5						₨ 1.1
Not Designated as Hedges [Member] | Foreign Exchange Forward [Member] | Australia, Dollars
Derivatives, Fair Value [Line Items]
Derivative, notional amount													$ 2
Not Designated as Hedges [Member] | When-Issued Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative, notional amount							$ 35
Derivative, number of outstanding derivative contracts | transactions		0	0	0	0	0	1		1	1	1	1	1
[1] In addition to the derivatives disclosed in the table, the Company enters into forward contracts to purchase when-issued mortgage-backed securities and tax exempt single family mortgage revenue bonds as part of its community reinvestment initiatives. At September 30, 2024, the Company had no outstanding contracts. At December 31, 2023, the Company had one outstanding contract with a total notional amount of $35 million and an immaterial fair value. Collateral amounts, which consist of cash and investment securities, are limited to the related derivative asset/liability balance and do not include excess collateral received/pledged.

Derivatives and Hedging Activ_5

Derivatives and Hedging Activities Derivatives and Hedging Activities (Schedule of Hedged Items in a Fair Value Hedging Relationship) (Details) - Long-term Debt [Member] - USD ($) $ in Millions		Sep. 30, 2024	Dec. 31, 2023
Schedule of Hedged Items in Fair Value Hedging Relationship [Line Items]
Carrying amount of hedged assets/liabilities		$ 15,490	$ 8,620
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	[1]	162	0
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)		$ 6	$ 12
[1] The balance includes $6 million and $12 million of cumulative hedging adjustments related to discontinued hedging relationships as of September 30, 2024 and December 31, 2023, respectively.

Derivatives and Hedging Activ_6

Derivatives and Hedging Activities (Schedule of Impact of the Derivative Instruments on Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI into earnings, cash flow hedges	$ (31)	$ (29)	$ (112)	$ (50)
Credit card loans	4,092	3,726	11,989	10,513
Designated as Hedges [Member] | Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI into earnings, cash flow hedges			0
Other Comprehensive Income (Loss), Cash Flow Hedge, Reclassification for Discontinuance, before Tax	$ 13		13
Gains on hedged items, fair value hedges			0
Losses on interest rate swaps, fair value hedges			0
Total gains on fair value hedges			$ 0
OCI, Cash Flow Hedge, Reclassification for Discontinuance, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other expense		Other expense
Deposits [Member] | Designated as Hedges [Member] | Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Reclassification for Discontinuance, before Tax	$ 0		$ 0
OCI, Cash Flow Hedge, Reclassification for Discontinuance, Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest Expense, Deposits		Interest Expense, Deposits
Long-term Debt [Member] | Designated as Hedges [Member] | Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Reclassification for Discontinuance, before Tax	$ 0		$ 0
OCI, Cash Flow Hedge, Reclassification for Discontinuance, Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest Expense, Long-Term Debt		Interest Expense, Long-Term Debt
Credit Card Loans [Member] | Designated as Hedges [Member] | Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Reclassification for Discontinuance, before Tax	$ 0		$ 0
OCI, Cash Flow Hedge, Reclassification for Discontinuance, Statement of Income or Comprehensive Income [Extensible Enumeration]	Credit card loans		Credit card loans
Interest Expense [Member] | Deposits [Member] | Designated as Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total amounts of income and expense line items presented in the condensed consolidated statements of income, where the effects of fair value or cash flow hedges are recorded	$ (1,213)	(1,061)	$ (3,622)	(2,722)
Interest Expense [Member] | Deposits [Member] | Designated as Hedges [Member] | Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI into earnings, cash flow hedges	0	0	0	0
Gains on hedged items, fair value hedges	(90)	0	(91)	0
Losses on interest rate swaps, fair value hedges	81	0	75	0
Total gains on fair value hedges	(9)	0	(16)	0
Interest Expense [Member] | Long-term Debt [Member] | Designated as Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total amounts of income and expense line items presented in the condensed consolidated statements of income, where the effects of fair value or cash flow hedges are recorded	(236)	(225)	(729)	(622)
Interest Expense [Member] | Long-term Debt [Member] | Designated as Hedges [Member] | Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI into earnings, cash flow hedges	4	2	9	6
Gains on hedged items, fair value hedges	(187)	24	(76)	111
Losses on interest rate swaps, fair value hedges	145	(53)	(40)	(181)
Total gains on fair value hedges	(42)	(29)	(116)	(70)
Interest Income | Credit Card Loans [Member] | Designated as Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total amounts of income and expense line items presented in the condensed consolidated statements of income, where the effects of fair value or cash flow hedges are recorded	4,092	3,726	11,989	10,513
Interest Income | Credit Card Loans [Member] | Designated as Hedges [Member] | Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI into earnings, cash flow hedges	(48)	(31)	(134)	(56)
Gains on hedged items, fair value hedges	0	0	0	0
Losses on interest rate swaps, fair value hedges	0	0	0	0
Total gains on fair value hedges	0	0	0	0
Other Expense | Designated as Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total amounts of income and expense line items presented in the condensed consolidated statements of income, where the effects of fair value or cash flow hedges are recorded	(277)	(254)	$ (761)	(540)
Other Expense | Designated as Hedges [Member] | Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI into earnings, cash flow hedges	0	0		0
Gains on hedged items, fair value hedges	0	0		0
Losses on interest rate swaps, fair value hedges	0	0		0
Total gains on fair value hedges	$ 0	$ 0		$ 0

Segment Disclosures (Narrative)

Segment Disclosures (Narrative) (Details)	9 Months Ended
	Sep. 30, 2024 segment
Segment Reporting [Abstract]
Number of reportable segments (in number of segments)	2

Segment Disclosures (Schedule o

Segment Disclosures (Schedule of Segment Disclosures) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Interest income	$ 5,112	$ 4,610	$ 15,031	$ 12,977
Interest Expense, Operating	1,457	1,288	4,365	3,346
Net interest income	3,655	3,322	10,666	9,631
Provision for credit losses	1,473	1,702	3,709	4,109
Other income	798	705	2,485	1,983
Other expense	1,788	1,564	5,070	4,351
Income before income taxes	1,192	761	4,372	3,154
Credit Card Loans [Member]
Segment Reporting Information [Line Items]
Interest income	4,092	3,726	11,989	10,513
Total Other Loans [Member] | Private Student Loans [Member]
Segment Reporting Information [Line Items]
Interest income	244	261	764	768
Total Other Loans [Member] | Personal Loans [Member]
Segment Reporting Information [Line Items]
Interest income	360	305	1,040	831
Total Other Loans [Member] | Other Loans [Member]
Segment Reporting Information [Line Items]
Interest income	138	87	379	224
Unallocated Financing Receivables | Other [Member]
Segment Reporting Information [Line Items]
Interest income	278	231	859	641
Operating Segments [Member] | Digital Banking [Member]
Segment Reporting Information [Line Items]
Interest income	5,112	4,610	15,031	12,977
Interest Expense, Operating	1,457	1,288	4,365	3,346
Net interest income	3,655	3,322	10,666	9,631
Provision for credit losses	1,473	1,702	3,709	4,109
Other income	669	575	1,901	1,650
Other expense	1,743	1,519	4,929	4,220
Income before income taxes	1,108	676	3,929	2,952
Operating Segments [Member] | Digital Banking [Member] | Credit Card Loans [Member]
Segment Reporting Information [Line Items]
Interest income	4,092	3,726	11,989	10,513
Operating Segments [Member] | Digital Banking [Member] | Total Other Loans [Member] | Private Student Loans [Member]
Segment Reporting Information [Line Items]
Interest income	244	261	764	768
Operating Segments [Member] | Digital Banking [Member] | Total Other Loans [Member] | Personal Loans [Member]
Segment Reporting Information [Line Items]
Interest income	360	305	1,040	831
Operating Segments [Member] | Digital Banking [Member] | Total Other Loans [Member] | Other Loans [Member]
Segment Reporting Information [Line Items]
Interest income	138	87	379	224
Operating Segments [Member] | Digital Banking [Member] | Unallocated Financing Receivables | Other [Member]
Segment Reporting Information [Line Items]
Interest income	278	231	859	641
Operating Segments [Member] | Payment Services [Member]
Segment Reporting Information [Line Items]
Interest income	0	0	0	0
Interest Expense, Operating	0	0	0	0
Net interest income	0	0	0	0
Provision for credit losses	0	0	0	0
Other income	129	130	584	333
Other expense	45	45	141	131
Income before income taxes	84	85	443	202
Operating Segments [Member] | Payment Services [Member] | Credit Card Loans [Member]
Segment Reporting Information [Line Items]
Interest income	0	0	0	0
Operating Segments [Member] | Payment Services [Member] | Total Other Loans [Member] | Private Student Loans [Member]
Segment Reporting Information [Line Items]
Interest income	0	0	0	0
Operating Segments [Member] | Payment Services [Member] | Total Other Loans [Member] | Personal Loans [Member]
Segment Reporting Information [Line Items]
Interest income	0	0	0	0
Operating Segments [Member] | Payment Services [Member] | Total Other Loans [Member] | Other Loans [Member]
Segment Reporting Information [Line Items]
Interest income	0	0	0	0
Operating Segments [Member] | Payment Services [Member] | Unallocated Financing Receivables | Other [Member]
Segment Reporting Information [Line Items]
Interest income	$ 0	$ 0	$ 0	$ 0

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Schedule of Revenue from Contracts with Customers Disaggregated by Business Segment) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Discount and interchange revenue, net	[1]	$ 363	$ 360	$ 1,121	$ 1,027
Protection products revenue		42	42	126	129
Transaction processing revenue		84	82	262	221
Noninterest Income, Other, Subject to ASC 606		95	21	357	71
Total other income subject to ASC 606	[2]	584	505	1,866	1,448
Loan fee income		214	194	619	546
Other income (loss)			6		(11)
Revenue Not from Contract with Customer, Excluding Interest Income		214	200	619	535
Total other income		798	705	2,485	1,983
Customer rewards included in discount and interchange revenue		779	787	2,200	2,300
Deposit product fees reported in net interest income and excluded from other income subject to ASC 606		2	3	6	13
Operating Segments [Member] | Digital Banking [Member]
Disaggregation of Revenue [Line Items]
Discount and interchange revenue, net	[1]	337	337	1,044	963
Protection products revenue		42	42	126	129
Transaction processing revenue		0	0	0	0
Noninterest Income, Other, Subject to ASC 606		76	2	112	12
Total other income subject to ASC 606	[2]	455	381	1,282	1,104
Loan fee income		214	194	619	546
Other income (loss)			0		0
Revenue Not from Contract with Customer, Excluding Interest Income		214	194	619	546
Total other income		669	575	1,901	1,650
Operating Segments [Member] | Payment Services [Member]
Disaggregation of Revenue [Line Items]
Discount and interchange revenue, net	[1]	26	23	77	64
Protection products revenue		0	0	0	0
Transaction processing revenue		84	82	262	221
Noninterest Income, Other, Subject to ASC 606		19	19	245	59
Total other income subject to ASC 606	[2]	129	124	584	344
Loan fee income		0	0	0	0
Other income (loss)			6		(11)
Revenue Not from Contract with Customer, Excluding Interest Income		0	6	0	(11)
Total other income		$ 129	$ 130	$ 584	$ 333
[1] Net of rewards, including Cashback Bonus rewards, of $779 million and $787 million for the three months ended September 30, 2024 and 2023, respectively, and $2.2 billion and $2.3 billion for the nine months ended September 30, 2024 and 2023 , respectively. Excludes $2 million and $3 million of deposit product fees that are reported within net interest income for the three months ended September 30, 2024 and 2023, respectively, and $6 million and $13 million for the nine months ended September 30, 2024 and 2023, respectively.