Discover Financial Services (DFS) 10-Q 29 Apr 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document	3 Months Ended
	Mar. 31, 2014	Apr. 25, 2014
Document Information [Line Items]	'	'
Document type	'10-Q	'
Amendment flag	'false	'
Document period end date	31-Mar-14	'
Document fiscal year focus	'2014	'
Document fiscal period focus	'Q1	'
Entity registrant name	'Discover Financial Services	'
Entity central index key	'0001393612	'
Current fiscal year end date	'--12-31	'
Entity filer category	'Large Accelerated Filer	'
Entity common stock, shares outstanding	'	466,273,816

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Financial Condition (USD $)	Mar. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Assets	'		'
Cash and cash equivalents	$8,731		$6,554
Restricted cash	1,163		182
Investment securities:	'		'
Available-for-sale (amortized cost of $3,868 and $4,900 at March 31, 2014 and December 31, 2013, respectively)	3,902	[1]	4,931	[1]
Held-to-maturity (fair value of $62 and $58 at March 31, 2014 and December 31, 2013, respectively)	62	[2]	60	[2]
Total investment securities	3,964		4,991
Loan receivables:	'		'
Mortgage loans held for sale, measured at fair value	133	[3]	148	[3]
Loan portfolio:	'		'
Credit card	50,879		53,150
Other	8,794		8,295
Purchased credit-impaired loans	4,046		4,178
Total loan portfolio	63,719		65,623
Total loan receivables	63,852		65,771
Allowance for loan losses	-1,591		-1,648
Net loan receivables	62,261		64,123
Premises and equipment, net	668		654
Goodwill	284		284
Intangible assets, net	182		185
Other assets	2,331		2,367
Total assets	79,584		79,340
Deposits:	'		'
Interest-bearing deposit accounts	44,813		44,766
Non-interest bearing deposit accounts	171		193
Total deposits	44,984		44,959
Short-term borrowings	124		140
Long-term borrowings	20,182		20,474
Accrued expenses and other liabilities	3,273		2,958
Total liabilities	68,563		68,531
Commitments, contingencies and guarantees (Notes 8, 11, and 12)	'		'
Stockholders’ Equity:	'		'
Common stock, par value $0.01 per share; 2,000,000,000 shares authorized; 558,034,622 and 555,349,629 shares issued at March 31, 2014 and December 31, 2013, respectively	5		5
Preferred stock, par value $0.01 per share; 200,000,000 shares authorized; 575,000 shares issued or outstanding and aggregate liquidation preference of $575 at March 31, 2014 and December 31, 2013	560		560
Additional paid-in capital	3,739		3,687
Retained earnings	10,138		9,611
Accumulated other comprehensive loss	-70		-68
Treasury stock, at cost; 89,651,099 and 83,105,578 shares at March 31, 2014 and December 31, 2013, respectively	-3,351		-2,986
Total stockholders’ equity	11,021		10,809
Total liabilities and stockholders’ equity	79,584		79,340
Variable Interest Entity, Primary Beneficiary [Member]	'		'
Assets	'		'
Restricted cash	1,160		179
Loan portfolio:	'		'
Allowance for loan losses	-807		-861
Other assets	37		34
Deposits:	'		'
Long-term borrowings	16,295		16,986
Accrued expenses and other liabilities	8		9
Variable Interest Entity, Primary Beneficiary [Member] | Credit Card Securitization Trusts [Member]	'		'
Assets	'		'
Restricted cash	1,069		90
Loan portfolio:	'		'
Credit card	29,157	[4]	31,112	[4]
Allowance for loan losses	-779	[4]	-833	[4]
Other assets	37		34
Variable Interest Entity, Primary Beneficiary [Member] | Student Loan Securitization Trusts [Member]	'		'
Assets	'		'
Restricted cash	91		89
Loan portfolio:	'		'
Purchased credit-impaired loans	2,177		2,248
Allowance for loan losses	($28)	[4]	($28)	[4]
[1]	Available-for-sale investment securities are reported at fair value.
[2]	Held-to-maturity investment securities are reported at amortized cost.
[3]	Substantially all mortgage loans held for sale are pledged as collateral against the warehouse line of credit used to fund consumer residential loans.
[4]	The Company maintains its allowance for loan losses at an amount sufficient to absorb probable losses inherent in all loan receivables, which includes all loan receivables in the trusts. Therefore, credit risk associated with the transferred receivables is fully reflected on the Company’s balance sheet in accordance with GAAP.

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Financial Condition (Parenthetical) (USD $)	Mar. 31, 2014		Dec. 31, 2013
Statement of Financial Position [Abstract]	'		'
Available-for-sale investment securities, amortized cost (in dollars)	$3,868,000,000	[1]	$4,900,000,000	[1]
Held-to-maturity investment securities, fair value (in dollars)	62,000,000	[2]	58,000,000	[2]
Common stock, par value per share	$0.01		$0.01
Common stock, shares authorized	2,000,000,000		2,000,000,000
Common stock, shares issued	558,034,622		555,349,629
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	575,000		575,000
Preferred stock, shares outstanding (in shares)	575,000		575,000
Preferred stock, liquidation preference (in dollars)	$575,000,000		$575,000,000
Treasury Stock, shares	89,651,099		83,105,578
[1]	Available-for-sale investment securities are reported at fair value.
[2]	Held-to-maturity investment securities are reported at amortized cost.

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Income (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Interest income:	'	'
Credit card loans	$1,537	$1,451
Other loans	275	234
Investment securities	16	20
Other interest income	5	3
Total interest income	1,833	1,708
Interest expense:	'	'
Deposits	153	186
Short-term borrowings	1	1
Long-term borrowings	116	111
Total interest expense	270	298
Net interest income	1,563	1,410
Provision for loan losses	272	159
Net interest income after provision for loan losses	1,291	1,251
Other income:	'	'
Discount and interchange revenue, net	254	263
Protection products revenue	83	88
Loan fee income	83	81
Transaction processing revenue	44	53
Gain on investments	4	3
Gain on origination and sale of mortgage loans	16	51
Other income	31	43
Total other income	515	582
Other expense:	'	'
Employee compensation and benefits	307	290
Marketing and business development	169	169
Information processing and communications	84	78
Professional fees	99	104
Premises and equipment	23	19
Other expense	102	93
Total other expense	784	753
Income before income tax expense	1,022	1,080
Income tax expense	391	407
Net income	631	673
Net income allocated to common stockholders	$618	$659
Basic earnings per common share (in dollars per share)	$1.31	$1.33
Diluted earnings per common share (in dollars per share)	$1.31	$1.33
Dividends declared per common share (in dollars per share)	$0.20	$0

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net income	$631	$673
Other comprehensive income (loss), net of taxes	'	'
Unrealized gain (loss) on securities available for sale, net of tax	2	-11
Unrealized loss on cash flow hedges, net of tax	-4	-1
Other comprehensive loss	-2	-12
Comprehensive income	$629	$661

Condensed_Consolidated_Stateme4

Condensed Consolidated Statements of Changes in Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Series B Preferred Stock [Member]	Series B Preferred Stock [Member]	Series B Preferred Stock [Member]
In Millions, except Share data, unless otherwise specified								Preferred Stock [Member]	Retained Earnings [Member]
Stockholders' equity, balance at beginning of period at Dec. 31, 2012	$9,873	$5	$3,598	$7,472	($72)	($1,690)	'	$560	'
Preferred stock, shares outstanding, balance at beginning of period (in shares) at Dec. 31, 2012	'	'	'	'	'	'	'	575,000	'
Common stock, shares outstanding, balance at beginning of period (in shares) at Dec. 31, 2012	'	553,351,000	'	'	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'	'
Net income	673	'	'	673	'	'	'	'	'
Other comprehensive income (loss), net of tax	-12	'	'	'	-12	'	'	'	'
Purchases of treasury stock	-261	'	'	'	'	-261	'	'	'
Common stock issued under employee benefit plans (in shares)	'	15,000	'	'	'	'	'	'	'
Common stock issued under employee benefit plans	1	0	1	'	'	'	'	'	'
Common stock issued and stock-based compensation expense (in shares)	'	1,490,000	'	'	'	'	'	'	'
Common stock issued and stock-based compensation expense	34	1	33	'	'	'	'	'	'
Dividends, Series B preferred stock	-9	'	'	'	'	'	-9	'	-9
Stockholders' equity, balance at end of period at Mar. 31, 2013	10,299	6	3,632	8,136	-84	-1,951	'	560	'
Preferred stock, shares outstanding, balance at end of period (in shares) at Mar. 31, 2013	'	'	'	'	'	'	'	575,000	'
Common stock, shares outstanding, balance at end of period (in shares) at Mar. 31, 2013	'	554,856,000	'	'	'	'	'	'	'
Stockholders' equity, balance at beginning of period at Dec. 31, 2013	10,809	5	3,687	9,611	-68	-2,986	'	560	'
Preferred stock, shares outstanding, balance at beginning of period (in shares) at Dec. 31, 2013	575,000	'	'	'	'	'	'	575,000	'
Common stock, shares outstanding, balance at beginning of period (in shares) at Dec. 31, 2013	'	555,350,000	'	'	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'	'
Net income	631	'	'	631	'	'	'	'	'
Other comprehensive income (loss), net of tax	-2	'	'	'	-2	'	'	'	'
Purchases of treasury stock	-365	'	'	'	'	-365	'	'	'
Common stock issued under employee benefit plans (in shares)	'	14,000	'	'	'	'	'	'	'
Common stock issued under employee benefit plans	1	0	1	'	'	'	'	'	'
Common stock issued and stock-based compensation expense (in shares)	'	2,671,000	'	'	'	'	'	'	'
Common stock issued and stock-based compensation expense	51	0	51	'	'	'	'	'	'
Dividends, common stock	-95	'	'	-95	'	'	'	'	'
Dividends, Series B preferred stock	-9	'	'	'	'	'	-9	'	-9
Stockholders' equity, balance at end of period at Mar. 31, 2014	$11,021	$5	$3,739	$10,138	($70)	($3,351)	'	$560	'
Preferred stock, shares outstanding, balance at end of period (in shares) at Mar. 31, 2014	575,000	'	'	'	'	'	'	575,000	'
Common stock, shares outstanding, balance at end of period (in shares) at Mar. 31, 2014	'	558,035,000	'	'	'	'	'	'	'

Condensed_Consolidated_Stateme5

Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities	'	'
Net income	$631	$673
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Provision for loan losses	272	159
Deferred income taxes	23	121
Depreciation and amortization on premises and equipment	29	25
Amortization of deferred revenues	-51	-48
Other depreciation and amortization	61	43
Accretion of accretable yield on acquired loans	-68	-70
Gain on investments	-4	-3
Loss on equity method and other investments	7	4
Gain on origination and sale of loans	-16	-51
Stock-based compensation expense	18	17
Proceeds from sale of mortgage loans originated for sale	512	1,249
Net principal disbursed on mortgage loans originated for sale	-478	-1,156
Changes in assets and liabilities:	'	'
Increase in other assets	-41	-88
Increase in accrued expenses and other liabilities	234	617
Net cash provided by operating activities	1,129	1,492
Cash flows from investing activities	'	'
Maturities and sales of available-for-sale investment securities	1,276	1,015
Purchases of available-for-sale investment securities	-101	-90
Maturities of held-to-maturity investment securities	5	13
Purchases of held-to-maturity investment securities	-8	0
Net principal disbursed on loans originated for investment	1,692	2,102
Purchases of loan receivables	0	-133
Purchases of other investments	-29	-31
Increase in restricted cash	-981	-192
Purchases of premises and equipment	-43	-59
Net cash provided by investing activities	1,811	2,625
Cash flows from financing activities	'	'
Net decrease in short-term borrowings	-16	-37
Proceeds from issuance of securitized debt	1,650	1,700
Maturities and repayment of securitized debt	-2,352	-899
Proceeds from issuance of other long-term borrowings	399	750
Proceeds from issuance of common stock	1	5
Purchases of treasury stock	-365	-261
Net increase in deposits	26	187
Dividends paid on common and preferred stock	-106	-79
Net cash (used for) provided by financing activities	-763	1,366
Net increase in cash and cash equivalents	2,177	5,483
Cash and cash equivalents, at beginning of period	6,554	2,584
Cash and cash equivalents, at end of period	$8,731	$8,067

Background_and_Basis_of_Presen

Background and Basis of Presentation	3 Months Ended
	Mar. 31, 2014
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 direct banking and payment services company. The Company is a bank holding company under the Bank Holding Company Act of 1956 as well as a financial holding company under the Gramm-Leach-Bliley Act and therefore is subject to oversight, regulation and examination by the Board of Governors of the Federal Reserve System (the “Federal Reserve”). Through its Discover Bank subsidiary, a Delaware state-chartered bank, the Company offers its customers credit card loans, private student loans, personal loans, home equity loans and deposit products. Through its Discover Home Loans, Inc. subsidiary, the Company offers its customers home loans. Through its DFS Services LLC subsidiary and its subsidiaries, the Company operates the Discover Network, the PULSE network (“PULSE”), and Diners Club International (“Diners Club”). The Discover Network is a payment card transaction processing network for Discover branded credit cards and credit, debit and prepaid cards, issued by third parties, which the Company refers to as network partners. PULSE operates an electronic funds transfer network, providing financial institutions issuing debit cards on the PULSE network with access to ATMs domestically and internationally, as well as point-of-sale terminals at retail locations throughout the U.S. for debit card transactions. Diners Club is a global payments network of licensees that issue Diners Club branded charge cards and/or provide card acceptance services.
	The Company’s business segments are Direct Banking and Payment Services. The Direct Banking segment includes consumer banking and lending products, specifically Discover branded credit cards issued to individuals and small businesses on the Discover Network and other consumer products and services, including private student loans, personal loans, home loans, home equity loans, prepaid cards and other consumer lending and deposit products. The majority of Direct 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.
	The Payment Services segment includes PULSE, Diners Club and the Company’s network partners business, which includes credit, debit and prepaid cards issued on the Discover Network by third parties. This segment also includes the business operations of Diners Club Italy, which primarily consist of issuing Diners Club charge cards. The majority of Payment Services revenues relate to transaction processing revenue from PULSE and royalty and licensee revenue (included in other income) from Diners Club.
	Basis of Presentation
	The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“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 which are necessary for a fair presentation of the 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 2013 audited consolidated financial statements filed with the Company’s annual report on Form 10-K for the calendar year ended December 31, 2013.
	Recently Issued Accounting Pronouncements.
	In January 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-01, Investments-Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Qualified Affordable Housing Projects. This standard will permit a reporting entity to make an accounting policy election to account for investments in qualified affordable housing projects using the proportional amortization method if certain conditions are met. Under this new method, an entity amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as a component of income tax expense (benefit). This treatment will replace the effective yield method currently permitted for certain investments of this kind. The Company has not historically utilized the effective yield method, and as a result, implementation of this ASU will not impact the Company’s accounting for its investments in qualified affordable housing projects unless a subsequent election is made to apply it. In addition to establishing the conditions under which the proportional amortization method can be used, the ASU calls for additional disclosures that will enable the reader to understand the nature of the investment and the effect of its measurement and related tax credits on the company’s financial position and results of operations. The new guidance is effective for annual reporting periods beginning after December 15, 2014 and interim periods within those periods, with early adoption permitted. The standard will require additional disclosure about the nature of the Company's affordable housing investments, but unless the Company subsequently decides to elect the new accounting model, the new guidance will have no effect on the Company’s financial condition, results of operations or cash flows.

Investments

Investments	3 Months Ended
	Mar. 31, 2014
Investments, Debt and Equity Securities [Abstract]	'
Investments	'
	Investments
	The Company’s investment securities consist of the following (dollars in millions):
		March 31,			December 31,
		2014			2013
	U.S. Treasury securities(1)	$	1,343		$	2,058
	U.S. government agency securities	1,047			1,561
	States and political subdivisions of states	10			15
	Other securities:
	Credit card asset-backed securities of other issuers	—			6
	Residential mortgage-backed securities - Agency(2)	1,564			1,351
	Total other securities	1,564			1,357
	Total investment securities	$	3,964		$	4,991
	-1	Includes $7 million and $9 million of U.S. Treasury securities that have been pledged as swap collateral in lieu of cash as of March 31, 2014 and December 31, 2013, respectively.
	-2	Consists of residential mortgage-backed securities issued by Fannie Mae, Freddie Mac and 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
		Cost			Unrealized			Unrealized
					Gains			Losses
	31-Mar-14
	Available-for-Sale Investment Securities(1)
	U.S. Treasury securities	$	1,320		$	22		$	—			$	1,342
	U.S. government agency securities	1,025			22			—				1,047
	Residential mortgage-backed securities - Agency	1,523			3			(13		)		1,513
	Total available-for-sale investment securities	$	3,868		$	47		$	(13	)		$	3,902
	Held-to-Maturity Investment Securities(2)
	U.S. Treasury securities(3)	$	1		$	—		$	—			$	1
	States and political subdivisions of states	10			—			—				10
	Residential mortgage-backed securities - Agency(4)	51			—			—				51
	Total held-to-maturity investment securities	$	62		$	—		$	—			$	62
	31-Dec-13
	Available-for-Sale Investment Securities(1)
	U.S. Treasury securities	$	2,030		$	27		$	—			$	2,057
	U.S. government agency securities	1,535			26			—				1,561
	Credit card asset-backed securities of other issuers	6			—			—				6
	Residential mortgage-backed securities - Agency	1,329			—			(22		)		1,307
	Total available-for-sale investment securities	$	4,900		$	53		$	(22	)		$	4,931
	Held-to-Maturity Investment Securities(2)
	U.S. Treasury securities(3)	$	1		$	—		$	—			$	1
	States and political subdivisions of states	15			—			(1		)		14
	Residential mortgage-backed securities - Agency(4)	44			—			(1		)		43
	Total held-to-maturity investment securities	$	60		$	—		$	(2	)		$	58
	-1	Available-for-sale investment securities are reported at fair value.
	-2	Held-to-maturity investment securities are reported at amortized cost.
	-3	Amount represents securities pledged as collateral to a government-related merchant for which transaction settlement occurs beyond the normal 24-hour period.
	-4	Amounts represent residential mortgage-backed securities that were classified as held-to-maturity as they were entered into as a part of the Company's community reinvestment initiatives.
	The following table provides information about 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		Less than 12 months							More than 12 months
		Securities
		in a Loss
		Position		Fair			Unrealized				Fair			Unrealized
				Value			Losses				Value			Losses
	At March 31, 2014
	Available-for-Sale Investment Securities
	Residential mortgage-backed securities - Agency	22		$	999		$	(12	)		$	47		$	(1	)
	Held-to-Maturity Investment Securities
	State and political subdivisions of states	4		$	5		$	—			$	3		$	—
	Residential mortgage backed securities - Agency	5		$	29		$	—			$	—		$	—
	At December 31, 2013
	Available-for-Sale Investment Securities
	Residential mortgage-backed securities - Agency	23		$	1,097		$	(20	)		$	48		$	(2	)
	Held-to-Maturity Investment Securities
	State and political subdivisions of states	4		$	8		$	(1	)		$	3		$	—
	Residential mortgage backed securities - Agency	2		$	40		$	(1	)		$	—		$	—
During the three months ended March 31, 2014, and 2013, the Company received $60 million and $309 million of proceeds related to maturities, or redemptions of investment securities. For the three months ended March 31, 2014, these proceeds primarily resulted from $49 million maturities of residential mortgage-backed securities and $6 million maturities of credit card asset-backed securities of other issuers. For the three months ended March 31, 2013, the proceeds primarily resulted from $100 million maturities of U.S. government agency securities, $82 million maturities of residential mortgage-backed securities, and $75 million maturities of U.S. Treasury securities.
The Company records gains and losses on investment securities in other income when investments are sold or liquidated, when the Company believes an investment is other than temporarily impaired prior to the disposal of the investment, or in certain other circumstances. Proceeds from the sales of available-for-sale investment securities, comprised of U.S. Treasury securities and U.S. government agency securities, were $1.2 billion and $719 million during the three months ended March 31, 2014 and 2013, respectively. The Company recognized gains on sales of available-for-sale investment securities of $4 million and $2 million during the three months ended March 31, 2014 and 2013, respectively, which were calculated using the specific identification method and were recorded entirely in earnings. There were no gains or losses related to other-than-temporary impairments during the three months ended March 31, 2014 and 2013.
The Company records unrealized gains and losses on its available-for-sale investment securities in other comprehensive income. For the three months ended March 31, 2014, the Company recorded net unrealized gains of $3 million ($2 million after tax) in other comprehensive income. For the three months ended March 31, 2013, the Company recorded net unrealized losses of $16 million ($11 million after tax) in other comprehensive income.
Maturities of available-for-sale debt securities and held-to-maturity debt securities at the end of the period are provided in the table below (dollars in millions):
	One Year			After One			After Five				After Ten			Total
	or			Year			Years				Years
	Less			Through			Through
				Five Years			Ten Years
At March 31, 2014
Available-for-sale—Amortized Cost(1)
U.S. Treasury securities	$	126		$	1,194		$	—			$	—		$	1,320
U.S. government agency securities	102			923			—				—			1,025
Residential mortgage-backed securities - Agency	—			—			422				1,101			1,523
Total available-for-sale investment securities	$	228		$	2,117		$	422			$	1,101		$	3,868
Held-to-maturity—Amortized Cost(2)
U.S. Treasury securities	$	1		$	—		$	—			$	—		$	1
State and political subdivisions of states	—			—			—				10			10
Residential mortgage-backed securities - Agency	—			—			—				51			51
Total held-to-maturity investment securities	$	1		$	—		$	—			$	61		$	62
Available-for-sale—Fair Values(1)
U.S. Treasury securities	$	127		$	1,215		$	—			$	—		$	1,342
U.S. government agency securities	103			944			—				—			1,047
Residential mortgage-backed securities - Agency	—			—			420				1,093			1,513
Total available-for-sale investment securities	$	230		$	2,159		$	420			$	1,093		$	3,902
Held-to-maturity—Fair Values(2)
U.S. Treasury securities	$	1		$	—		$	—			$	—		$	1
State and political subdivisions of states	—			—			—				10			10
Residential mortgage-backed securities - Agency	—			—			—				51			51
Total held-to-maturity investment securities	$	1		$	—		$	—			$	61		$	62
-1	Available-for-sale investment securities are reported at fair value.
-2	Held-to-maturity investment securities are reported at amortized cost.
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, as well as stimulate economic development in low to moderate income communities. These investments are accounted for using the equity method of accounting, and are recorded within other assets, and the related commitment for future investments is recorded in accrued expenses and other liabilities within the statement of financial condition. The portion of each investment's operating results allocable to the Company is recorded in other expense within the condensed consolidated statement of income. The Company earns a return primarily through the receipt of tax credits allocated to the affordable housing projects and the community revitalization projects. These investments are not consolidated as the Company does not have a controlling financial interest in the entities. As of March 31, 2014 and December 31, 2013, the Company had outstanding investments in these entities of $300 million and $308 million, respectively, and related contingent liabilities of $28 million and $52 million, respectively.

Loan_Receivables

Loan Receivables	3 Months Ended
	Mar. 31, 2014
Loans and Leases Receivable Disclosure [Abstract]	'
Loan Receivables	'
	Loan Receivables
	The Company has three portfolio segments: credit card loans, other loans and purchased credit-impaired ("PCI") student loans.
	The Company's classes of receivables within the three portfolio segments are depicted in the table below (dollars in millions):
		March 31,				December 31,
		2014				2013
	Mortgage loans held for sale(1)	$	133			$	148
	Loan portfolio:
	Credit card loans:
	Discover card(2)	50,685				52,952
	Discover business card	194				198
	Total credit card loans	50,879				53,150
	Other loans:
	Personal loans	4,310				4,191
	Private student loans	4,326				3,969
	Other	158				135
	Total other loans	8,794				8,295
	Purchased credit-impaired loans(3)	4,046				4,178
	Total loan portfolio	63,719				65,623
	Total loan receivables	63,852				65,771
	Allowance for loan losses	(1,591		)		(1,648		)
	Net loan receivables	$	62,261			$	64,123
	-1	Substantially all mortgage loans held for sale are pledged as collateral against the warehouse line of credit used to fund consumer residential loans.
	-2	Amounts include $19.6 billion and $20.2 billion underlying investors’ interest in trust debt at March 31, 2014 and December 31, 2013, respectively, and $9.5 billion and $10.9 billion in seller's interest at March 31, 2014 and December 31, 2013, respectively. See Note 4: Credit Card and Student Loan Securitization Activities for further information.
	-3	Amounts include $2.2 billion of loans pledged as collateral against the notes issued from the Student Loan Corporation ("SLC") securitization trusts at March 31, 2014 and December 31, 2013. See Note 4: Credit Card and Student Loan Securitization Activities. Of the remaining $1.8 billion and $2.0 billion at March 31, 2014 and December 31, 2013, respectively, that were not pledged as collateral, approximately $22 million for each period represents loans eligible for reimbursement through an indemnification claim. Discover Bank must purchase such loans from the trust before a claim may be filed.
	Credit Quality Indicators
	The Company regularly reviews its collection experience (including delinquencies and net charge-offs) in determining its allowance for loan losses. Credit card and closed-end consumer loan receivables are placed on nonaccrual status upon receipt of notification of the bankruptcy or death of a customer or suspected fraudulent activity on an account. Upon completion of the fraud investigation, non-fraudulent credit card and closed-end consumer loan receivables may resume accruing interest.
	Information related to the delinquent and non-accruing loans in the Company’s loan portfolio, which excludes loans held for sale, is shown below by each class of loan receivables except for PCI student loans, which is shown under the heading “— Purchased Credit-Impaired Loans” (dollars in millions):
		30-89 Days				90 or				Total Past				90 or		Total
		Delinquent				More Days				Due				More Days		Non-accruing(1)
						Delinquent								Delinquent
														and
														Accruing
	At March 31, 2014
	Credit card loans:
	Discover card(2)	$	432			$	441			$	873			$	402	$	162
	Discover business card	2				1				3				2		1
	Total credit card loans	434				442				876				404		163
	Other loans:
	Personal loans(3)	21				8				29				7		5
	Private student loans (excluding PCI)(4)	51				26				77				26		—
	Other	1				2				3				—		39
	Total other loans (excluding PCI)	73				36				109				33		44
	Total loan receivables (excluding PCI)	$	507			$	478			$	985			$	437	$	207
	At December 31, 2013
	Credit card loans:
	Discover card(2)	$	464			$	445			$	909			$	406	$	154
	Discover business card	1				2				3				2		1
	Total credit card loans	465				447				912				408		155
	Other loans:
	Personal loans(3)	21				8				29				8		5
	Private student loans (excluding PCI)(4)	48				18				66				18		—
	Other	1				2				3				—		40
	Total other loans (excluding PCI)	70				28				98				26		45
	Total loan receivables (excluding PCI)	$	535			$	475			$	1,010			$	434	$	200
	-1	The Company estimates that the gross interest income that would have been recorded in accordance with the original terms of non-accruing credit card loans was $7 million and $8 million for the three months ended March 31, 2014 and 2013, respectively. The Company does not separately systematically compute the amount of gross interest income that would have been recorded in accordance with the original terms of loans. This amount was estimated based on customers' quarterly average balances and rates prior to non-accrual status.
	-2	Consumer credit card loans that are 90 or more days delinquent and accruing interest include $42 million and $41 million of loans accounted for as troubled debt restructurings at March 31, 2014 and December 31, 2013, respectively.
	-3	Personal loans that are 90 or more days delinquent and accruing interest include $2 million of loans accounted for as troubled debt restructurings at March 31, 2014 and December 31, 2013.
	-4	Private student loans that are 90 or more days delinquent and accruing interest include $3 million of loans accounted for as troubled debt restructurings at March 31, 2014 and December 31, 2013.
	Net Charge-offs
	The Company's net charge-offs include the principal amount of loans charged off less principal recoveries and exclude charged-off interest and fees, recoveries of interest and fees and fraud losses. Charged-off and recovered interest and fees are recorded in interest income and loan fee income, respectively, which is effectively a reclassification of the loan loss provision, while fraud losses are recorded in other expense. Credit card loan receivables are charged off at the end of the month during which an account becomes 180 days contractually past due. Personal loans and private student loans, which are closed-end consumer loan receivables are generally charged off at the end of the month during which an account becomes 120 days contractually past due. Generally, customer bankruptcies and probate accounts are charged off at the end of the month 60 days following the receipt of notification of the bankruptcy or death but not later than the 180-day or 120-day contractual time frame.
	Information related to the net charge-offs in the Company's loan portfolio, which excludes loans held for sale, is shown below by each class of loan receivables except for PCI student loans, which is shown under the heading "— Purchased Credit-Impaired Loans" (dollars in millions):
		For the Three Months Ended March 31,
		2014							2013
	Net				Net			Net				Net
	Charge-offs				Charge-off			Charge-offs				Charge-off
					Rate							Rate
Credit card loans:
Discover card	$	293			2.32	%		$	286			2.36	%
Discover business card	1				1.76	%		1				2.66	%
Total credit card loans	294				2.32	%		287				2.36	%
Other loans:
Personal loans	21				2.07	%		19				2.3	%
Private student loans (excluding PCI)	14				1.31	%		7				0.82	%
Total other loans (excluding PCI)	35				1.67	%		26				1.49	%
Net charge-offs as a percentage of total loans (excluding PCI)	$	329			2.22	%		$	313			2.25	%
Net charge-offs as a percentage of total loans (including PCI)	$	329			2.08	%		$	313			2.08	%
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 as well as information from credit bureaus, such as FICO or other credit scores, relating to the customer’s broader credit performance. FICO scores are generally obtained at origination of the account and are refreshed monthly or quarterly thereafter to assist in predicting customer behavior. Historically, the Company has noted that a significant proportion of delinquent accounts have FICO scores below 660.
The following table provides the most recent FICO scores available for the Company’s customers as a percentage of each class of loan receivables:
	Credit Risk Profile
	by FICO Score
	660 and Above			Less than 660
				or No Score
31-Mar-14
Discover card	82	%		18	%
Discover business card	92	%		8	%
Personal loans	97	%		3	%
Private student loans (excluding PCI)(1)	95	%		5	%
31-Dec-13
Discover card	83	%		17	%
Discover business card	92	%		8	%
Personal loans	97	%		3	%
Private student loans (excluding PCI)(1)	95	%		5	%
-1	PCI loans are discussed under the heading "— Purchased Credit-Impaired Loans."
For private student loans, additional credit risk management activities include monitoring the amount of loans in forbearance. Forbearance allows borrowers experiencing temporary financial difficulties, but still willing to make payments, the ability to temporarily suspend payments. Eligible borrowers have a lifetime cap on forbearance of 12 months. At March 31, 2014 and December 31, 2013, there were $77 million and $110 million of private student loans, including PCI, in forbearance, respectively. In addition, at March 31, 2014 and December 31, 2013, there were 1.4% and 1.9% of private student loans in forbearance as a percentage of student loans in repayment and forbearance, respectively. At March 31, 2014, the dollar amount of loans in forbearance and loans in forbearance as a percentage of private student loans in repayment and forbearance were lower when compared to December 31, 2013 due the implementation of temporary reduced payment programs, which normally consist of a reduction of the minimum payment for a period of no longer than 12 months at a time. Loans in these programs are not considered to be in forbearance.
Allowance for Loan Losses
The Company maintains an allowance for loan losses at an appropriate level to absorb probable losses inherent in the loan portfolio. The Company considers the collectibility of all amounts contractually due on its loan receivables, including those components representing interest and fees. Accordingly, the allowance for loan losses represents the estimated uncollectible principal, interest and fee components of loan receivables. The allowance is evaluated monthly and is maintained through an adjustment to the provision for loan losses. Charge-offs of principal amounts of loans outstanding are deducted from the allowance and subsequent recoveries of such amounts increase the allowance. Charge-offs of loan balances representing unpaid interest and fees result in a reversal of interest and fee income, respectively, which is effectively a reclassification of provision for loan losses.
The Company bases its allowance for loan losses on several analyses that help estimate incurred losses as of the balance sheet date. While the Company’s estimation process includes historical data and analysis, there is a significant amount of judgment applied in selecting inputs and analyzing the results produced by the models to determine the allowance. The Company uses a migration analysis to estimate the likelihood that a loan will progress through the various stages of delinquency. The Company uses other analyses to estimate losses incurred on non-delinquent accounts. The considerations in these analyses include past performance, risk management techniques applied to various accounts, historical behavior of different account vintages, economic conditions, recent trends in delinquencies, bankruptcy filings, account collection management, policy changes, account seasoning, loan volume and amounts, payment rates, and forecasting uncertainties. The Company primarily estimates its allowance for loan losses on a pooled basis, which includes loans that are delinquent and/or no longer accruing interest and/or certain loans that have defaulted from a loan modification program, as discussed below under the section entitled "— Troubled Debt Restructurings." Certain other loans, including non-performing Diners Club licensee loans, are individually evaluated for impairment.
The following tables provide changes in the Company’s allowance for loan losses (dollars in millions):
	For the Three Months Ended March 31, 2014
	Credit Card				Personal Loans				Student Loans				Other		Total
Balance at beginning of period	$	1,406			$	112			$	113			$	17	$	1,648
Additions:
Provision for loan losses	230				18				23				1		272
Deductions:
Charge-offs	(408		)		(24		)		(15		)		—		(447		)
Recoveries	114				3				1				—		118
Net charge-offs	(294		)		(21		)		(14		)		—		(329		)
Balance at end of period	$	1,342			$	109			$	122			$	18	$	1,591
	For the Three Months Ended March 31, 2013
	Credit Card				Personal Loans				Student Loans				Other		Total
Balance at beginning of period	$	1,613			$	99			$	75			$	1	$	1,788
Additions:
Provision for loan losses	127				17				15				—		159
Deductions:
Charge-offs	(422		)		(20		)		(7		)		—		(449		)
Recoveries	135				1				—				—		136
Net charge-offs	(287		)		(19		)		(7		)		—		(313		)
Balance at end of period	$	1,453			$	97			$	83			$	1	$	1,634
Net charge-offs of principal are recorded against the allowance for loan losses, as shown in the table above. Information regarding net charge-offs of interest and fee revenues on credit card and other loans is as follows (dollars in millions):
	For the Three Months Ended March 31,
	2014				2013
Interest and fees accrued subsequently charged off, net of recoveries (recorded as a reduction of interest income)	$	72			$	77
Fees accrued subsequently charged off, net of recoveries (recorded as a reduction to other income)	$	17			$	16
The following tables provide additional detail of the Company’s allowance for loan losses and recorded investment in its loan portfolio (which excludes loans held for sale) by impairment methodology (dollars in millions):
	Credit Card				Personal				Student				Other		Total
					Loans				Loans				Loans
At March 31, 2014
Allowance for loans evaluated for impairment as:
Collectively evaluated for impairment in accordance with ASC 450-20	$	1,164			$	104			$	84			$	1	$	1,353
Evaluated for impairment in accordance with	178				5				10				17		210
ASC 310-10-35(1)(2)
Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				28				—		28
Total allowance for loan losses	$	1,342			$	109			$	122			$	18	$	1,591
Recorded investment in loans evaluated for impairment as:
Collectively evaluated for impairment in accordance with ASC 450-20	$	49,791			$	4,265			$	4,296			$	80	$	58,432
Evaluated for impairment in accordance with	1,088				45				30				78		1,241
ASC 310-10-35(1)(2)
Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				4,046				—		4,046
Total recorded investment	$	50,879			$	4,310			$	8,372			$	158	$	63,719
At December 31, 2013
Allowance for loans evaluated for impairment as:
Collectively evaluated for impairment in accordance with ASC 450-20	$	1,218			$	109			$	76			$	1	$	1,404
Evaluated for impairment in accordance with	188				3				9				16		216
ASC 310-10-35(1)(2)
Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				28				—		28
Total allowance for loan losses	$	1,406			$	112			$	113			$	17	$	1,648
Recorded investment in loans evaluated for impairment as:
Collectively evaluated for impairment in accordance with ASC 450-20	$	52,027			$	4,160			$	3,941			$	56	$	60,184
Evaluated for impairment in accordance with	1,123				31				28				79		1,261
ASC 310-10-35(1)(2)
Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				4,178				—		4,178
Total recorded investment	$	53,150			$	4,191			$	8,147			$	135	$	65,623
-1	Loan receivables evaluated for impairment in accordance with ASC 310-10-35 include credit card loans, personal loans and student loans collectively evaluated for impairment in accordance with ASC Subtopic 310-40, Receivables, which consists of modified loans accounted for as troubled debt restructurings. Other loans are individually evaluated for impairment and generally do not represent troubled debt restructurings.
-2	The unpaid principal balance of credit card loans was $919 million and $900 million at March 31, 2014 and December 31, 2013, respectively. The unpaid principal balance of personal loans was $44 million and $31 million at March 31, 2014 and December 31, 2013, respectively. The unpaid principal balance of student loans was $28 million and $26 million at March 31, 2014 and December 31, 2013, respectively. All loans accounted for as troubled debt restructurings have a related allowance for loan losses.
Troubled Debt Restructurings
Permanent and certain temporary modification programs for credit card loans as well as loans that defaulted or graduated from modification programs, certain grants of student loan forbearance and certain modifications to personal loans as well as those that defaulted or graduated from modification programs are considered troubled debt restructurings and are accounted for in accordance with ASC Subtopic 310-40, Troubled Debt Restructurings by Creditors. Generally, loans included in a loan modification program are considered to be individually impaired and are accounted for as troubled debt restructurings. The Company has both internal and external 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.
For credit card customers, the temporary hardship program primarily consists of a reduced minimum payment and an interest rate reduction, both lasting for a period no longer than 12 months. The permanent workout program involves changing the structure of the loan to a fixed payment loan with a maturity no longer than 60 months and reducing the interest rate on the loan. The permanent modification program does not normally provide for the forgiveness of unpaid principal, but may allow for the reversal of certain unpaid interest or fee assessments. The Company also makes loan modifications for customers who request financial assistance through external sources, such as a consumer credit counseling agency program (referred to here as external programs). These loans typically receive a reduced interest rate but continue to be subject to the original minimum payment terms and do not normally include waiver of unpaid principal, interest or fees.
To assist student loan borrowers who are experiencing temporary financial difficulties but are willing to resume making payments, the Company may offer forbearance periods of up to 12 months over the life of the loan. The Company does not anticipate significant shortfalls in the contractual amount due for borrowers using a first forbearance period as the historical performance of these borrowers is not significantly different from the overall portfolio. However, when a delinquent borrower is granted a second forbearance period, the forbearance is considered a troubled debt restructuring. In addition, we offer temporary reduced payment programs, which normally consist of a reduction of the minimum payment for a period of no longer than 12 months at a time. Student loans included in temporary reduced payment programs are not accounted for as troubled debt restructurings as long as the term of the program does not exceed 12 months.
For personal loan customers, the Company offers two temporary programs which normally consist of a reduction of the minimum payment for a period of no longer than 12 months with a final balloon payment required at the end of the loan term. In addition, the temporary APR reduction program also provides an interest rate reduction for up to 12 months. The permanent modification programs involve changing the terms of the loan in order to pay off the outstanding balance over the new term for a period no longer than 4 years. The total term, including both the original and renegotiated terms, generally does not exceed 9 years. The Company offers another permanent modification program which modifies the interest rate along with the term of the loan. The Company also allows loan modifications for personal loan customers who request financial assistance through external sources, similar to credit card customers discussed above. Payments are modified based on the new terms agreed upon with the credit counseling agency. Personal loans modified through temporary and permanent programs are accounted for as troubled debt restructurings. Beginning in first quarter of 2014, loan modifications through external sources are accounted for as troubled debt restructurings.
Loans classified as troubled debt restructurings are recorded at their present value with impairment measured as the difference between the loan balance and the discounted present value of cash flows expected to be collected. Consistent with the Company’s measurement of impairment of modified loans on a pooled basis, the discount rate used for credit card loans in internal programs is the average current annual percentage rate applied to non-impaired credit card loans, which approximates what would have applied to the pool of modified loans prior to impairment. The discount rate used for credit card loans in external programs reflects a rate that is consistent with rates offered to lower risk cardmembers. For student and personal loans, the discount rate used is the average contractual rate prior to modification.
Interest income from loans accounted for as troubled debt restructurings is accounted for in the same manner as other accruing loans. Cash collections on these loans are allocated according to the same payment hierarchy methodology applied to loans that are not in such programs.
Additional information about modified loans classified as troubled debt restructurings is shown below (dollars in millions):
	Average recorded investment in loans				Interest income recognized during period loans were impaired(1)				Gross interest income that would have been recorded with original terms(2)
For the Three Months Ended March 31, 2014
Credit card loans
Modified credit card loans(3)	$	256			$	11			$	1
Internal programs	$	454			$	3			$	15
External programs	$	394			$	7			$	3
Personal loans	$	44			$	1			$	—
Student loans(4)	$	29			$	1			N/A
For the Three Months Ended March 31, 2013
Credit card loans
Modified credit card loans(3)	$	279			$	13			$	1
Internal programs	$	490			$	3			$	17
External programs	$	507			$	10			$	3
Personal loans	$	22			$	1			$	—
Student loans(4)	$	18			$	—			N/A
-1	The Company does not separately track interest income on loans in modification programs. Amounts shown are estimated by applying an average interest rate to the average loans in the various modification programs.
-2	The Company does not separately track the amount of gross interest income that would have been recorded if the loans in modification programs had not been restructured and interest had instead been recorded in accordance with the original terms. Amounts shown are estimated by applying the difference between the average interest rate earned on non-impaired credit card loans and the average interest rate earned on loans in the modification programs to the average loans in the modification programs.
-3	This balance is considered impaired, but is excluded from the internal and external program amounts reflected in this table. Represents credit card loans that were modified in troubled debt restructurings, but are no longer enrolled in troubled debt restructuring program due to noncompliance with the terms of the modification or successful completion of a program
-4	Student loan customers who have been granted a forbearance are not given interest rate reductions.
In order to evaluate the primary financial effects that resulted from credit card loans entering into a loan modification program during the three months ended March 31, 2014 and 2013, the Company quantified the amount by which interest and fees were reduced during the periods. During the three months ended March 31, 2014 and 2013, the Company forgave approximately $10 million and $11 million, respectively, of interest and fees as a result of accounts entering into a credit card loan modification program.
The following table provides information on loans that entered a loan modification program during the period (dollars in millions):
	For the Three Months Ended March 31,
	2014							2013
	Number of Accounts			Balances				Number of Accounts			Balances
Accounts that entered a loan modification program during the period:
Credit card:
Internal programs	12,436			$	81			10,402			$	66
External programs	8,431			$	44			9,531			$	52
Personal loans	712			$	8			443			$	6
Student loans	307			$	4			172			$	4
The following table presents the carrying value of loans that experienced a payment default during the period that had been modified in a troubled debt restructuring during the 15 months preceding the end of each period (dollars in millions):
	For the Three Months Ended March 31,
	2014							2013
	Number of Accounts			Aggregated Outstanding Balances Upon Default				Number of Accounts			Aggregated Outstanding Balances Upon Default
Troubled debt restructurings that subsequently defaulted:
Credit card:
Internal programs(1)(2)	2,331			$	14			2,880			$	18
External programs(1)(2)	1,881			$	8			2,251			$	10
Personal loans(2)	106			$	1			24			$	—
Student loans(3)	311			$	5			135			$	3
-1	The outstanding balance upon default is the loan balance at the end of the month prior to default. Terms revert back to the pre-modification terms for customers who default from a temporary program and charging privileges remain revoked.
-2	A customer defaults from a modification program after two consecutive missed payments.
-3	Student loan defaults have been defined as loans that are 60 or more days delinquent.
Of the account balances that defaulted as shown above for the three months ended March 31, 2014 and 2013, approximately 34% and 45%, respectively, of the total balances charged off at the end of the month in which they defaulted. For accounts that have defaulted from a loan modification program and have not subsequently charged off, the balances are included in the allowance for loan loss analysis discussed above under "— Allowance for Loan Losses."
Purchased Credit-Impaired Loans
Purchased loans with evidence of credit deterioration since origination for which it is probable that not all contractually required payments will be collected are considered impaired at acquisition and are reported as PCI loans. The private student loans acquired in the SLC transaction as well as the additional private student loan portfolio acquired from Citibank, comprise the Company’s only PCI loans at March 31, 2014 and December 31, 2013. Total PCI student loans had an outstanding balance of $4.4 billion and $4.6 billion, including accrued interest, and a related carrying amount of $4.0 billion and $4.2 billion as of March 31, 2014 and December 31, 2013, respectively.
The following table provides changes in accretable yield for the acquired loans during the period (dollars in millions):
	For the Three Months Ended March 31,
	2014				2013
Balance at beginning of period	$	1,580			$	2,072
Accretion into interest income	(68		)		(70		)
Other changes in expected cash flows	—				19
Balance at end of period	$	1,512			$	2,021
Periodically, the Company updates the estimate of cash flows expected to be collected based on management's latest expectations of future credit losses, borrower prepayments and certain other assumptions that affect cash flows. The Company recorded no provision expense during the three months ended March 31, 2014 and 2013. The allowance for PCI loan losses at March 31, 2014 and December 31, 2013 was $28 million. There was no impact on accretable yield as a result of changes in cash flow assumptions for the three months ended March 31, 2014. For the three months ended March 31, 2013, changes to other cash flow assumptions resulted in an increase in accretable yield related to expected life of the loans. Changes to accretable yield are recognized prospectively as an adjustment to yield over the remaining life of the pools.
At March 31, 2014, the 30 or more days delinquency and 90 or more days delinquency rates on PCI student loans (which includes loans not yet in repayment) were 2.19% and 0.79%, respectively. At December 31, 2013, the 30 or more days delinquency and 90 or more days delinquency rates on PCI student loans (which includes loans not yet in repayment) were 2.33% and 0.80%, respectively. These rates include private student loans that are greater than 120 days delinquent that are covered by an indemnification agreement or insurance arrangements through which the Company expects to recover a substantial portion of the loan. The net charge-off rate on PCI student loans was 0.75% and 1.43% for the three months ended March 31, 2014 and 2013, respectively. The decrease in net charge-off rate on PCI student loans is primarily due to seasoning of the portfolio and introduction of the temporary interest only programs, which reduce the borrower's minimum payment for a period of no longer than 12 months at a time.
Mortgage Loans Held For Sale
The Company originates all of its residential real estate loans, except for home equity loans, with the intent to sell them in the secondary market. Loans held for sale consist primarily of residential first mortgage loans that are secured by residential real estate throughout the United States. Mortgage loans are funded through a warehouse line of credit and are recorded at fair value. Changes in the fair value of mortgage loans are recorded through other income prior to the sale of the loans to investors. The gain or loss on the sale of loans is recognized on the date the loans are sold and is based on the difference between the sale proceeds received and the carrying value of the loans, adjusted for the impact of the related hedges. See Note 14: Derivatives and Hedging Activities for further discussion of the mortgage loan related hedging activities. The Company sells its loans on a servicing released basis in which the Company gives up the right to service the loans.
The following table provides a summary of the initial unpaid principal balance of mortgage loans sold during the period, by type of loan  (dollars in millions):
	For the Three Months Ended March 31,
	2014							2013
	Amount				%			Amount				%
Conforming(1)	$	447			89.94	%		$	665			55.51	%
FHA(2)	48				9.66			533				44.49
Jumbo(3)	2				0.4			—				—
Total	$	497			100	%		$	1,198			100	%
-1	Conforming loans are loans that conform to Government Sponsored Enterprises guidelines.
-2	FHA loans are loans that are insured by the Federal Housing Administration and are typically made to borrowers with low down payments. The initial loan amount must be within certain limits.
-3	Jumbo loans are loans with an initial amount larger than the limits set by a Government Sponsored Enterprise.
The following table represents the loans held for sale by type of loan (dollars in millions):
	March 31, 2014							December 31, 2013
	Amount				%			Amount				%
Conforming(1)	$	116			87.22	%		$	136			91.89	%
FHA(2)	13				9.77			11				7.43
Jumbo(3)	4				3.01			1				0.68
Total	$	133			100	%		$	148			100	%
-1	Conforming loans are loans that conform to Government Sponsored Enterprises guidelines.
-2	FHA loans are loans that are insured by the Federal Housing Administration and are typically made to borrowers with low down payments. The initial loan amount must be within certain limits.
-3	Jumbo loans are loans with an initial loan amount larger than the limits set by a Government Sponsored Enterprise.

Credit_Card_and_Student_Loan_S

Credit Card and Student Loan Securitization Activities	3 Months Ended
	Mar. 31, 2014
Variable Interest Entities Disclosure [Abstract]	'
Credit Card and Student Loan Securitization Activities	'
	Credit Card and Student Loan Securitization Activities
	Credit Card Securitization Activities
	The Company accesses the term asset securitization market through the Discover Card Master Trust I (“DCMT”) and the Discover Card Execution Note Trust (“DCENT”), which are trusts into which credit card loan receivables are transferred (or, in the case of DCENT, into which beneficial interests in DCMT are transferred) and from which beneficial interests are issued to investors.
	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. In this structure, in order 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, the majority of which are held by wholly-owned subsidiaries of Discover Bank. The DCMT structure consists of Class A, triple-A rated certificates and Class B, single-A rated certificates held by third parties. Credit enhancement is provided by the subordinated Class B certificates, cash collateral accounts, and more subordinated Series 2009-CE certificates that are held by a wholly-owned subsidiary of Discover Bank. The credit-related risk of loss associated with trust assets as of the balance sheet date to which the Company is exposed through the retention of these subordinated interests is fully captured in the allowance for loan losses recorded by the Company.
	The Company’s credit card securitizations are accounted for as secured borrowings and the trusts are treated as consolidated subsidiaries of the Company. The Company’s retained interests in the assets of the trusts, principally consisting of investments in DCMT certificates and DCENT notes held by subsidiaries of Discover Bank, constitute intercompany positions which are eliminated in the preparation of the Company’s condensed consolidated statement 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 trusts’ creditors. Further, the transferred credit card loan receivables are owned by the trust and are not available to third party creditors of the Company. The trusts have ownership of cash balances that also have restrictions, the amounts of which are reported in restricted cash. Investment of trust cash balances is limited to investments that are permitted under the governing documents of the trusts and which have maturities no later than the related date on which funds must be made available for distribution to trust investors. With the exception of the seller’s interest in trust receivables, the Company’s interests in trust assets are generally subordinate to the interests of third-party investors and, as such, may not be realized by the Company if needed to absorb deficiencies in cash flows that are allocated to the investors in the trusts’ debt.
	The carrying values of these restricted assets, which are presented on the Company’s condensed consolidated statement of financial condition as relating to securitization activities, are shown in the table below (dollars in millions):
		March 31,			December 31,
		2014			2013
	Cash collateral accounts	$	8		$	59
	Collections and interest funding accounts	1,061			31
	Restricted cash	1,069			90
	Investors’ interests held by third-party investors	14,589			15,190
	Investors’ interests held by wholly-owned subsidiaries of Discover Bank	5,033			5,024
	Seller’s interest	9,535			10,898
	Loan receivables(1)	29,157			31,112
	Allowance for loan losses allocated to securitized loan receivables(1)	(779		)	(833		)
	Net loan receivables	28,378			30,279
	Other	37			34
	Carrying value of assets of consolidated variable interest entities	$	29,484		$	30,403
	-1	The Company maintains its allowance for loan losses at an amount sufficient to absorb probable losses inherent in all loan receivables, which includes all loan receivables in the trusts. Therefore, credit risk associated with the transferred receivables is fully reflected on the Company’s balance sheet 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, the securitization structures include certain features that could result in earlier-than-expected repayment of the securities. The primary investor protection feature relates to the availability and adequacy of cash flows in the securitized pool of receivables to meet contractual requirements. Insufficient cash flows would trigger the early repayment of the securities. This is referred to as the “economic early amortization” feature.
	Investors are allocated cash flows derived from activities related to the accounts comprising the securitized pool of receivables, the amounts of which reflect finance charges billed, certain fee assessments, allocations of merchant discount and interchange, and recoveries on charged-off accounts. From these cash flows, investors are reimbursed for charge-offs occurring within the securitized pool of receivables and receive a contractual rate of return and Discover Bank is paid a servicing fee as servicer. Any cash flows remaining in excess of these requirements are reported to investors as excess spread. An excess spread rate of less than 0% for a contractually specified period, generally a three-month average, would trigger an economic early amortization event. In such an event, the Company would be required to seek immediate sources of replacement funding. 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 Company is required to maintain a contractual minimum level of receivables in the trust in excess of the face value of outstanding investors’ interests. This excess is referred to as the minimum seller’s interest requirement. The required minimum seller’s interest in the pool of trust receivables, which is included in credit card loan receivables restricted for securitization investors, is set at approximately 7% in excess of the total investors’ interests (which includes interests held by third parties as well as those certificated interests held by the Company). If the level of receivables in the trust was to fall below the required minimum, the Company would be required to add receivables from the unrestricted pool of receivables, which would increase the amount of credit card loan receivables restricted for securitization investors. A decline in the amount of the excess seller’s interest could occur if balance repayments and charge-offs exceeded new lending on the securitized accounts or as a result of changes in total outstanding investors’ interests. Seller's interest is impacted by seasonality as higher balance repayments tend to occur in the first calendar year quarter. If the Company could not add enough receivables to satisfy the requirement, an early amortization (or repayment) of investors’ interests would be triggered. We retain significant exposure to the performance of trust assets through holdings of the seller's interest and subordinated security classes of DCMT and DCENT. In addition, the Company has the right to remove a random selection of accounts, which would serve to decrease the amount of credit card loan receivables restricted for securitization investors, subject to certain requirements including that the minimum seller's interest is still met.
	Another feature of the Company’s credit card securitization structure that is designed to protect investors’ interests from loss, which is applicable only to the notes issued from DCENT, is a reserve account funding requirement in which excess cash flows generated by the transferred loan receivables are held at the trust. This funding requirement is triggered when DCENT’s three-month average excess spread rate decreases to below 4.5%, with increasing funding requirements as excess spread levels decline below preset levels to 0%.
	In addition to performance measures associated with the transferred credit card loan receivables or the inability to add receivables to satisfy the seller's interest requirement, there are other events or conditions which could trigger an early amortization event, such as non-payment of principal at expected maturity. As of March 31, 2014, no economic or other early amortization events have occurred.
	The tables below provide information concerning investors’ interests and related excess spreads at the end of the current period (dollars in millions):
	March 31, 2014	Investors’			# of Series
		Interests(1)			Outstanding
	Discover Card Master Trust I	$	168		2
	Discover Card Execution Note Trust (DiscoverSeries notes)	19,454			38
	Total investors’ interests	$	19,622		40
	-1	Investors’ interests include third-party interests and subordinated interests held by wholly-owned subsidiaries of Discover Bank.
		3-Month Rolling
		Average Excess
		Spread(1)
	Group excess spread percentage	13.47	%
	DiscoverSeries excess spread percentage	13.46	%
	-1	DCMT certificates refer to the higher of the Group excess spread or their applicable series excess spread (not shown) and DiscoverSeries notes refer to the higher of the Group or DiscoverSeries excess spread in assessing whether an economic early amortization has been triggered.
	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.
	Student Loan Securitization Activities
	The Company’s student loan securitizations are accounted for as secured borrowings and the trusts are treated as consolidated subsidiaries of the Company. Trust receivables underlying third-party investors’ interests are recorded in purchased credit-impaired loans, and the related debt issued by the trusts is reported in long-term borrowings. The assets of the Company’s consolidated VIEs are restricted from being sold or pledged as collateral for other borrowings and the cash flows from these restricted assets may be used only to pay obligations of the trust.
	Currently there are three trusts from which securities were issued to investors. Principal payments on the long-term secured borrowings are made as cash is collected on the underlying loans that are used as collateral on the secured borrowings. The Company does not have access to cash collected by the securitization trusts until cash is released in accordance with the trust indenture agreements and, for certain securitizations, no cash will be released to the Company until all outstanding trust borrowings have been repaid. Similar to the credit card securitizations, the Company continues to own and service the accounts that generate the student loan receivables held by the trusts and receives servicing fees from the trusts based on either a percentage of the principal balance outstanding or a flat fee per borrower. Although the servicing fee income offsets the fee expense related to the trusts, failure to service the transferred loan receivables in accordance with contractual requirements could lead to a termination of the servicing rights.
	Under terms of all the trust arrangements, the Company has the option, but not the obligation, to provide financial support to the trusts, but has never provided such support. A substantial portion of the credit risk associated with the securitized loans has been transferred to third parties under private credit insurance or indemnification arrangements.
	The carrying values of these restricted assets, which are presented on the Company’s condensed consolidated statement of financial condition as relating to securitization activities, are shown in the table below (dollars in millions):
		March 31,			December 31,
		2014			2013
	Restricted cash	$	91		$	89
	Student loan receivables	2,177			2,248
	Allowance for loan losses allocated to securitized loan receivables(1)	(28		)	(28		)
	Net student loan receivables	2,149			2,220
	Carrying value of assets of consolidated variable interest entities	$	2,240		$	2,309
	-1	The Company maintains its allowance for loan losses at an amount sufficient to absorb probable losses inherent in all loan receivables, which includes all loan receivables in the trusts. Therefore, credit risk associated with the transferred receivables is fully reflected on the Company’s balance sheet in accordance with GAAP.

Deposits

Deposits	3 Months Ended
	Mar. 31, 2014
Deposits [Abstract]	'
Deposits	'
	Deposits
	The Company offers its deposit products to customers through two channels: (i) through direct marketing, internet origination and affinity relationships (“direct-to-consumer deposits”); and (ii) indirectly through contractual arrangements with securities brokerage firms (“brokered deposits”). Direct-to-consumer deposits include certificates of deposit, money market accounts, online savings and checking accounts, and IRA certificates of deposit, while brokered deposits include certificates of deposit, and sweep accounts.
	As of March 31, 2014 and December 31, 2013, the Company had approximately $28.7 billion and $28.4 billion, respectively, of direct-to-consumer deposits. As of each of March 31, 2014 and December 31, 2013, the Company had approximately $16.1 billion and $16.4 billion, respectively, of brokered deposits.
	A summary of interest-bearing deposit accounts is as follows (dollars in millions):
		March 31,			December 31,
		2014			2013
	Certificates of deposit in amounts less than $100,000(1)	$	20,832		$	21,211
	Certificates of deposit from amounts of $100,000(1) to less than $250,000(1)	4,781			4,860
	Certificates of deposit in amounts of $250,000(1) or greater	1,163			1,180
	Savings deposits, including money market deposit accounts	18,037			17,515
	Total interest-bearing deposits	$	44,813		$	44,766
	Average annual interest rate	1.32		%	1.57		%
	-1	$100,000 represents the basic insurance amount previously covered by the FDIC. Effective July 21, 2010, the basic insurance per depositor was permanently increased to $250,000.
	At the end of the current period, certificates of deposit maturing over the remainder of this year, over each of the next four years, and thereafter were as follows (dollars in millions):
	Year	Amount
	2014	$	9,925
	2015	$	7,444
	2016	$	3,768
	2017	$	2,310
	2018	$	1,728
	Thereafter	$	1,601

LongTerm_Borrowings

Long-Term Borrowings	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Long-Term Borrowings	'
	Long-Term Borrowings
	Long-term borrowings consist of borrowings and capital leases 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 balances outstanding at period end (dollars in millions):
		March 31, 2014				December 31, 2013
		Outstanding		Interest		Outstanding		Interest		Interest Rate Terms	Maturity
				Rate				Rate
	Securitized Debt
	Fixed rate asset-backed securities
	Principal value	$	5,549	1.86	%	$	5,549	1.86	%	Various fixed rates	Various
	(including discount of $1 at March 31, 2014 and December 31, 2013, respectively)										February 2015 - July 2019
	Fair value adjustment(1)	5				5
	Book value	5,554				5,554
	Floating rate asset-backed securities	8,189		0.47	%	9,140		0.46	%	1-month LIBOR(2) +	Various
										15 to 58 basis points	April 2014 - January 2019
	Floating rate asset-backed securities	850		0.4	%	—		—	%	3-month LIBOR(2) +	Feb-17
										20 basis points
	Floating rate asset-backed securities	—		—	%	500		0.44	%	Commercial Paper	Mar-14
										rate + 30 basis points
	Total Discover Card Master Trust I and Discover Card Execution Note Trust	14,593				15,194
	Floating rate asset-backed securities	959		0.48	%	1,005		0.48	%	3-month LIBOR(2) +	Various
	(including discount of $118 and $129 at March 31, 2014 and December 31, 2013)									12 to 45 basis points	January 2019 - July 2036 (3)
	Floating rate asset-backed securities	410		4.25	%	434		4.25	%	Prime rate + 100 basis points	June 2031 (3)
	(including discount of $2 and $3 at March 31, 2014 and December 31, 2013)
	Floating rate asset-backed securities	100		4	%	105		4	%	Prime rate +	July 2042 (3)
	(including premium of $1 at March 31, 2014 and December 31, 2013)									75 basis points
	Floating rate asset-backed securities	233		3.66	%	248		3.66	%	1-month LIBOR(2) +	July 2042 (3)
	(including premium of $3 at March 31, 2014 and December 31, 2013)									350 basis points
	Total SLC Private Student Loan Trusts	1,702				1,792
	Total Long-Term Borrowings—owed to securitization investors	16,295				16,986
	Discover Financial Services (Parent Company)
	Fixed rate senior notes due 2017
	Principal value	400		6.45	%	400		6.45	%	Fixed	Jun-17
	Fair value adjustment(1)	8				13
	Book value	408				413
	Fixed rate senior notes due 2019	78		10.25	%	78		10.25	%	Fixed	Jul-19
	Fixed rate senior notes due 2022	221		5.2	%	219		5.2	%	Fixed	Apr-22
	(including discount of $101 and $103 at March 31, 2014 and December 31, 2013)(4)
	Fixed rate senior notes due 2022	338		3.85	%	335		3.85	%	Fixed	Nov-22
	(including discount of $162 and $165 at March 31, 2014 and December 31, 2013)(5)
	Discover Bank
	Senior bank notes due 2018	750		2	%	750		2	%	Fixed	Feb-18
	Senior bank notes due 2023	994		4.2	%	994		4.2	%	Fixed	Aug-23
	(including discount of $6 at March 31, 2014 and December 31, 2013)
	Senior bank notes due 2026	399		4.25	%	—		—	%	Fixed	Mar-26
	(including discount of $1 at March 31, 2014)
	Subordinated bank notes due 2019	200		8.7	%	200		8.7	%	Fixed	November 2019
	Subordinated bank notes due 2020	498		7	%	498		7	%	Fixed	April 2020
	(including discount of $2 at March 31, 2014 and December 31, 2013)
	Capital lease obligations	1		4.51	%	1		4.51	%	Fixed	Apr-16
	Total long-term borrowings	$	20,182			$	20,474
	-1	The Company uses interest rate swaps to hedge portions of these long-term borrowings against changes in fair value attributable to changes in LIBOR. See Note 14: Derivatives and Hedging Activities.
	-2	London Interbank Offered Rate (“LIBOR”).
	-3	Repayment of this debt is dependent upon the timing of principal and interest payments on the underlying student loans. The dates shown represent final maturity dates.
	-4	Discount primarily relates to $115 million cash premium paid at issuance as part of 2012 private exchange offer to replace higher rate borrowings with borrowings bearing lower interest rates. During the three months ended March 31, 2014 and 2013, respectively, $2 million of the premium paid was amortized and included in interest expense in the condensed consolidated statements of income.
	-5	Discount primarily relates to $176 million cash premium paid at issuance as part of 2012 private exchange offer to replace higher rate borrowings with borrowings bearing lower interest rates. During the three months ended March 31, 2014 and 2013. respectively, $3 million of the premium paid was amortized and included in interest expense in the condensed consolidated statements of income.
	Maturities
	Long-term borrowings had the following maturities at the end of the current period (dollars in millions):
	Year	Amount
	Due in 2014	$	2,040
	Due in 2015	3,305
	Due in 2016	3,050
	Due in 2017	2,908
	Due in 2018	2,650
	Thereafter	6,229
Total	$	20,182
The Company has access to committed undrawn capacity through private securitizations to support the funding of its credit card loan receivables. As of March 31, 2014 , the total commitment of secured credit facilities through private providers was $7.5 billion, none of which had been used at March 31, 2014. Access to the unused portions of the secured credit facilities is subject to the terms of the agreements with each of the providers which have various expirations in 2015 and 2016. Borrowings outstanding under each facility bear interest at a margin above LIBOR or the asset-backed commercial paper costs of each individual conduit 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.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income	3 Months Ended
	Mar. 31, 2014
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 income (loss) were as follows (dollars in millions):
		Unrealized Gain (Loss) on Available-for-Sale Investment Securities,			Gain (Loss) on Cash Flow Hedges,			Foreign Currency Translation Adjustments, Net of Tax(1)			Pension and Post Retirement Plan Gain (Loss),			Accumulated Other Comprehensive Income (Loss)
		Net of Tax			Net of Tax						Net of Tax
	Balance at December 31, 2012	$	71		$	3		—			$	(146	)	$	(72	)
	Net change	(11		)	(1		)	—			—			(12		)
	Balance at March 31, 2013	$	60		$	2		—			$	(146	)	$	(84	)
	Balance at December 31, 2013	$	19		$	13		1			$	(101	)	$	(68	)
	Net change	2			(4		)	—			—			(2		)
	Balance at March 31, 2014	$	21		$	9		1			$	(101	)	$	(70	)
	-1	Includes unrealized losses on hedge of net investment in foreign subsidiary, net of tax benefit and net gains on foreign currency translation adjustments.
	The table below presents the other comprehensive income (loss) 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 March 31, 2014
	Available-for-Sale Investment Securities:
	Net unrealized holding gains arising during the period	$	7		$	(3	)	$	4
	Amounts reclassified from accumulated other comprehensive income	(4		)	2			(2		)
	Net change	$	3		$	(1	)	$	2
	Cash Flow Hedges:
	Net unrealized losses arising during the period	$	(13	)	$	5		$	(8	)
	Amounts reclassified from accumulated other comprehensive income	7			(3		)	4
	Net change	$	(6	)	$	2		$	(4	)
	For the Three Months Ended March 31, 2013
	Available-for-Sale Investment Securities:
	Net unrealized holding losses arising during the period	$	(14	)	$	5		$	(9	)
	Amounts reclassified from accumulated other comprehensive income	(2		)	—			(2		)
	Net change	$	(16	)	$	5		$	(11	)
	Cash Flow Hedges:
	Amounts reclassified from accumulated other comprehensive income	(2		)	1			(1		)
	Net change	$	(2	)	$	1		$	(1	)

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2014
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, except effective income tax rate):
		For the Three Months Ended March 31,
		2014			2013
	Income before income tax expense	$	1,022		$	1,080
	Income tax expense	$	391		$	407
	Effective income tax rate	38.3		%	37.7		%
	Income tax expense decreased $16 million for the three months ended March 31, 2014, as compared to the same period in 2013, because of a decrease in pretax income. The effective tax rate increased from 37.7% for the three months ended March 31, 2013 to 38.3% for the three months ended March 31, 2014 due to deferred tax adjustments on limited partnership community reinvestment act investments.
	The Company is subject to examination by the Internal Revenue Service (“IRS”) and the tax authorities in various states. The tax years under examination vary by jurisdiction. The Company is pursuing an administrative appeal of the IRS’s proposed assessment for the years 1999 through 2005, when Discover was a subsidiary of Morgan Stanley. It is reasonably possible that a settlement of the IRS appeal and certain state audits may be made within 12 months of the reporting date. At this time, the Company believes it is reasonably possible that a reduction in the amount of unrecognized tax benefits of $99 million could be recognized as a result of such settlement.
	The IRS is currently examining 2006 through June 20, 2007. This period is also part of a Morgan Stanley audit. A separate post-spin examination covers the years 2008 through 2010. The Company regularly assesses the likelihood of additional assessments or settlements in each of the taxing jurisdictions resulting from these and subsequent years' examinations. The Company believes that its reserves are sufficient to cover any tax, penalties and interest that could result from such examinations.

Earnings_Per_Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	Earnings Per Share
	The following table presents the calculation of basic and diluted earnings per share ("EPS") (in millions, except per share amounts):
		For the Three Months Ended March 31,
		2014			2013
	Numerator:
	Net income	$	631		$	673
	Preferred stock dividends	(9		)	(9		)
	Net income available to common stockholders	622			664
	Income allocated to participating securities	(4		)	(5		)
	Net income allocated to common stockholders	$	618		$	659
	Denominator:
	Weighted average shares of common stock outstanding	471			496
	Effect of dilutive common stock equivalents	1			1
	Weighted average shares of common stock outstanding and common stock equivalents	472			497
	Basic earnings per common share	$	1.31		$	1.33
	Diluted earnings per common share	$	1.31		$	1.33
	Anti-dilutive securities were not material and had no impact on the computation of diluted EPS for the three months ended March 31, 2014 and 2013, respectively.

Capital_Adequacy

Capital Adequacy	3 Months Ended
	Mar. 31, 2014
Regulatory Capital Requirements [Abstract]	'
Capital Adequacy	'
	Capital Adequacy
	The Company is subject to the capital adequacy guidelines of the Federal Reserve, and Discover Bank (the “Bank”), the Company’s main banking subsidiary, is subject to various regulatory capital requirements as administered by the Federal Deposit Insurance Corporation (the “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 have a direct material effect on the financial position and results of the Company and the Bank. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company and the Bank must meet specific capital guidelines that involve quantitative measures of assets, liabilities, and certain off-balance sheet items, as calculated under regulatory accounting practices. Capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors.
	Quantitative measures established by regulation to ensure capital adequacy require the Company and the Bank to maintain minimum amounts and ratios (as defined in the regulations) of total risk-based capital and Tier 1 capital to risk-weighted assets, and of Tier 1 capital to average assets. As of March 31, 2014, the Company and the Bank met all capital adequacy requirements to which they were subject. Under regulatory capital requirements, the Company and the Bank must maintain minimum levels of capital that are dependent upon the risk-weighted amount or average level of the financial institution’s assets, specifically (a) 8% to 10% of total risk-based capital to risk-weighted assets (“total risk-based capital ratio”), (b) 4% to 6% of Tier 1 capital to risk-weighted assets (“Tier 1 risk-based capital ratio”) and (c) 4% to 5% of Tier 1 capital to average assets (“Tier 1 leverage ratio”). To be categorized as “well-capitalized,” the Company and the Bank must maintain minimum total risk-based, Tier 1 risk-based, and Tier 1 leverage ratios as set forth in the table below. As of March 31, 2014, the Company and the Bank met the requirements for well-capitalized status and there have been no conditions or events that management believes have changed the Company’s or the Bank’s category.
	The following table shows the actual capital amounts and ratios of the Company and the Bank and comparisons of each to the regulatory minimum and “well-capitalized” requirements (dollars in millions):
		Actual				Minimum Capital			Capital Requirements
						Requirements			To Be Classified as
									Well-Capitalized
		Amount		Ratio		Amount		Ratio	Amount		Ratio
	March 31, 2014
	Total capital (to risk-weighted assets)
	Discover Financial Services	$	12,175	18.1	%	$	5,389	≥8.0%	$	6,736	≥10.0%
	Discover Bank	$	10,705	16.1	%	$	5,324	≥8.0%	$	6,655	≥10.0%
	Tier 1 capital (to risk-weighted assets)
	Discover Financial Services	$	10,626	15.8	%	$	2,695	≥4.0%	$	4,042	≥6.0%
	Discover Bank	$	9,166	13.8	%	$	2,662	≥4.0%	$	3,993	≥6.0%
	Tier 1 capital (to average assets)
	Discover Financial Services	$	10,626	13.4	%	$	3,173	≥4.0%	$	3,966	≥5.0%
	Discover Bank	$	9,166	11.7	%	$	3,137	≥4.0%	$	3,921	≥5.0%
	December 31, 2013
	Total capital (to risk-weighted assets)
	Discover Financial Services	$	11,975	17.4	%	$	5,492	≥8.0%	$	6,865	≥10.0%
	Discover Bank	$	10,496	15.5	%	$	5,428	≥8.0%	$	6,785	≥10.0%
	Tier 1 capital (to risk-weighted assets)
	Discover Financial Services	$	10,409	15.2	%	$	2,746	≥4.0%	$	4,119	≥6.0%
	Discover Bank	$	8,941	13.2	%	$	2,714	≥4.0%	$	4,071	≥6.0%
	Tier 1 capital (to average assets)
	Discover Financial Services	$	10,409	13.4	%	$	3,116	≥4.0%	$	3,895	≥5.0%
	Discover Bank	$	8,941	11.6	%	$	3,077	≥4.0%	$	3,847	≥5.0%

Commitments_Contingencies_and_

Commitments, Contingencies and Guarantees	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments, Contingencies and Guarantees	'
	Commitments, Contingencies and Guarantees
	Lease Commitments
	The Company leases various office space and equipment under capital and non-cancelable operating leases, which expire at various dates through 2024. At the end of the current period, future minimum payments on leases with original terms in excess of one year consist of the following (dollars in millions):
		Capitalized		Operating
		Leases		Leases
	2014	$	—	$	12
	2015	1		13
	2016	—		12
	2017	—		10
	2018	—		7
	Thereafter	—		12
	Total minimum lease payments	1		$	66
	Less: Amount representing interest	—
	Present value of net minimum lease payments	$	1
	Unused Commitments to Extend Credit
	At March 31, 2014, the Company had unused commitments to extend credit for loans of approximately $166.5 billion. Such commitments 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 commitments, 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 and loan qualification.
	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 plus the principal amount of any other outstanding secured borrowings. The Company has recorded substantially all of the maximum potential amount of future payments in long-term borrowings on the Company’s statement 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.
	Mortgage Loans Representations and Warranties
	The Company sells loans it originates to investors on a servicing released basis and the risk of loss or default by the borrower is generally transferred to the investor. However, the Company is required by these investors to make certain representations and warranties relating to credit information, loan documentation and collateral. These representations and warranties may extend through the contractual life of the mortgage loan. Subsequent to the sale, if underwriting deficiencies, borrower fraud or documentation defects are discovered in individual mortgage loans, the Company may be obligated to repurchase the respective mortgage loan or indemnify the investors for any losses from borrower defaults if such deficiency or defect cannot be cured within the specified period following discovery. The Company has established a repurchase reserve based on expected losses. At March 31, 2014, this amount was not material and was included in accrued expenses and other liabilities on the condensed consolidated statements of financial condition. The related provision was included in other income on the condensed consolidated statements of income.
	Guarantees
	The Company has obligations under certain guarantee arrangements, including contracts and indemnification agreements, 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.
	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.
	The maximum potential amount of future payments related to such contingent obligations is dependent upon the transaction volume processed between the time a counterparty defaults on its settlement and the time at which the Company disables the settlement of any further transactions for the defaulting party, which could be one month depending on the type of guarantee/counterparty. 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.
	While the Company has some contractual remedies to offset these counterparty settlement exposures (such as letters of credit or pledged deposits), in the event that 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, based on historical transaction volume, would be as follows (dollars in millions):
		March 31,
		2014
	Diners Club:
	Merchant guarantee	$	173
	PULSE:
	ATM guarantee	$	1
	With regard to the counterparty settlement guarantees discussed above, 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 March 31, 2014, the Company had not recorded any contingent liability in the condensed consolidated financial statements for these counterparty exposures, and management believes that the probability of any payments under these arrangements is low.
	The Company also retains counterparty exposure for the obligations of Diners Club licensees that participate in the Citishare network, an electronic funds processing network. Through the Citishare network, Diners Club customers are able to access certain ATMs directly connected to the Citishare network. The Company’s maximum potential future payment under this counterparty exposure is limited to $15 million subject to annual adjustment based on actual transaction experience. However, as of March 31, 2014, the Company had not recorded any contingent liability in the condensed consolidated financial statements related to this counterparty exposure, and management believes that the probability of any payments under this arrangement is low.
	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 months ended March 31, 2014 or 2013.
	The maximum potential amount of obligations of the Discover Network arising as a result of 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 table below summarizes certain information regarding merchant chargeback guarantees (in millions):
		For the Three Months Ended March 31,
		2014		2013
	Aggregate sales transaction volume(1)	$	28,154	$	27,228
	-1	Represents period 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 March 31, 2014 or December 31, 2013. 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 higher risk due to various factors such as time delays in the delivery of products or services.
	The table below provides information regarding settlement withholdings and escrow deposits, which are recorded in interest-bearing deposit accounts, and accrued expenses and other liabilities on the Company’s condensed consolidated statements of financial condition (dollars in millions):
		March 31,		December 31,
		2014		2013
	Settlement withholdings and escrow deposits	$	21	$	17

Litigation_and_Regulatory_Matt

Litigation and Regulatory Matters	3 Months Ended
	Mar. 31, 2014
Litigation Disclosure [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 Company contests liability and/or the amount of damages as appropriate in each pending matter.
	The Company has historically relied on the arbitration clause in its cardmember agreements, which has in some instances limited the costs of, and the Company’s exposure to, litigation, but there can be no assurance that the Company will continue to be successful in enforcing its arbitration clause in the future. Legal challenges to the enforceability of these clauses have led most card issuers, and may cause the Company, to discontinue their use. In addition, bills are periodically introduced in Congress to directly or indirectly prohibit the use of pre-dispute arbitration clauses, and the 2010 Dodd-Frank Wall Street Reform and Consumer Protection Act (the "Reform Act") authorized the Consumer Financial Protection Bureau (the "CFPB") to conduct a study on pre-dispute arbitration clauses and, based on the study, potentially limit or ban arbitration clauses. A preliminary report on arbitration agreements issued by the CFPB expressed concerns about these agreements that may signal the CFPB is contemplating taking such steps. Further, the Company is involved in pending legal actions challenging its arbitration clause.
	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, consumer regulatory, accounting, tax and other operational matters, some of which may result in significant adverse judgments, settlements, fines, penalties, injunctions, decreases in regulatory ratings, customer restitution or other relief, which could materially impact the Company's financial statements, increase its cost of operations, or limit its ability to execute its business strategies and engage in certain business activities. The FDIC is completing its annual anti-money laundering/Bank Secrecy Act examination of Discover Bank and has notified the Company of certain potential program deficiencies. The CFPB has issued a Civil Investigative Demand to Discover Bank seeking documents and information regarding certain of Discover Bank’s student loan servicing practices. Discover Bank is cooperating with each of the agencies on these matters. If the FDIC or CFPB determines to bring an enforcement action, it could include demands for civil money penalties, changes to certain of Discover Bank’s business practices and on the student loan servicing matter, customer restitution.
	In accordance with applicable accounting guidance, the Company establishes an accrued liability for legal and regulatory matters when those matters present loss contingencies which are both probable and estimable. Litigation expense was not material for the three months ended March 31, 2014 and 2013.
	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 those losses the likelihood of which 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 $160 million. This estimated range of reasonably possible losses is based upon currently available information for those proceedings in which the Company is involved, takes into account the Company’s best estimate of such losses for those matters for which an estimate can be made, and does not represent the Company’s maximum potential loss exposure. Various aspects of the legal 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 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 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, and could adversely affect the Company’s reputation.
	The Company has been subject to two class action cases in relation to the Telephone Consumer Protection Act (“TCPA”). The cases were filed in the U.S. District Court for the Northern District of California on November 30, 2011 (Walter Bradley et al. v. Discover Financial Services) and on March 6, 2012 (Andrew Steinfeld v. Discover Financial Services, DFS Services LLC and Discover Bank). The plaintiff in each case alleges that the Company contacted him, and members of the class he seeks to represent, on their cellular telephones without their express consent in violation of the TCPA. The plaintiff in each case seeks statutory damages for alleged negligent and willful violations of the TCPA, attorneys’ fees, costs and injunctive relief. The TCPA provides for statutory damages of $500 for each violation ($1,500 for willful violations). The Company and class counsel entered into a preliminary settlement of both pending class actions. On September 10, 2013, the court granted preliminary approval of the settlement. On March 31, 2014, the court granted final approval of the settlement.
	On July 5, 2012, the Antitrust Division of the United States Department of Justice (the “Division”) issued a Civil Investigative Demand (“CID”) to the Company seeking information regarding an investigation related to potential violations of Sections 1 and 2 of the Sherman Act, 15 U.S.C. §§1-2, by an unidentified party other than Discover. The CID seeks documents, data and narrative responses to several interrogatories and document requests, related to the debit card market. A CID is a request for information in the course of a civil investigation and does not constitute the commencement of legal proceedings. The Division is permitted by statute to issue a CID to anyone whom it believes may have information relevant to an investigation. The receipt of a CID does not presuppose that there is probable cause to believe that a violation of the antitrust laws has occurred or that a formal complaint ultimately will be filed. The Company is cooperating with the Division in connection with the CID.
	On August 14, 2012, a purported shareholder, James Groen, filed a shareholder derivative action in the U.S. District Court for the Northern District of Illinois (Groen v. Nelms et al.) against the Company’s board of directors, certain current and former officers and directors, and the Company as nominal defendant. On August 27, 2012, a second purported shareholder, the Charter Township of Clinton Police and Fire Retirement System, filed a substantially identical shareholder derivative action in the same court against the same parties (Charter Township of Clinton Police and Fire Retirement System v. Nelms et al.). On September 25, 2012, the actions were consolidated, and on February 19, 2013, the plaintiffs filed an amended consolidated complaint. The consolidated complaint asserts claims against the board of directors and certain current and former officers and directors for alleged breach of fiduciary duty, corporate waste, and unjust enrichment arising out of the Company’s alleged violations of the law in connection with the marketing and sale of its protection products. The relief sought in the consolidated complaint includes changes to the Company’s corporate governance procedures; unspecified damages, injunctive relief, restitution, and disgorgement from the individual defendants; and attorneys’ fees. On April 5, 2013, the defendants filed a motion to dismiss the amended consolidated complaint, and on June 5, 2013, briefing on the motion to dismiss was completed. The motion to dismiss is currently pending.

Fair_Value_Measurements_and_Di

Fair Value Measurements and Disclosures	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements and Disclosures	'
	Fair Value Measurements and Disclosures
	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. ASC Topic 820, Fair Value Measurement, provides a three-level hierarchy for classifying financial instruments, which is based on whether the inputs to the valuation techniques used to measure the fair value of each financial instrument 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 in which the inputs used to measure fair value may fall into different levels of the fair value hierarchy, the level in the fair value hierarchy within which the fair value measurement in its entirety is classified is based on the lowest level input that is significant to the fair value measurement in its entirety. The Company may utilize both observable and unobservable inputs in determining the fair values of financial instruments classified within the Level 3 category.
	The determination of classification of its financial instruments within the fair value hierarchy is performed at least quarterly by the Company. For transfers in and out of the levels of the fair value hierarchy, the Company discloses the fair value measurement based on the value immediately preceding the transfer.
	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.
	During the three months ended March 31, 2014, there were no changes to the Company's valuation techniques that had, or are expected to have, a material impact on the Company's condensed consolidated financial position or results of operations.
	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 Prices in		Significant				Significant				Total
		Active Markets		Other				Unobservable
		for Identical		Observable				Inputs (Level 3)
		Assets (Level 1)		Inputs (Level 2)
	Balance at March 31, 2014
	Assets
	U.S Treasury securities	$	1,342	$	—			$	—			$	1,342
	U.S government agency securities	1,047		—				—				1,047
	Residential mortgage-backed securities - Agency	—		1,513				—				1,513
	Available-for-sale investment securities	$	2,389	$	1,513			$	—			$	3,902
	Mortgage loans held for sale	$	—	$	133			$	—			$	133
	Interest rate lock commitments	$	—	$	—			$	5			$	5
	Forward delivery contracts	—		1				—				1
	Other derivative financial instruments	—		67				—				67
	Derivative financial instruments	$	—	$	68			$	5			$	73
	Liabilities
	Forward delivery contracts	$	—	$	1			$	—			$	1
	Other derivative financial instruments	—		7				—				7
	Derivative financial instruments	$	—	$	8			$	—			$	8
	Balance at December 31, 2013
	Assets
	U.S Treasury securities	$	2,057	$	—			$	—			$	2,057
	U.S government agency securities	1,561		—				—				1,561
	Credit card asset-backed securities of other issuers	—		6				—				6
	Residential mortgage-backed securities - Agency	—		1,307				—				1,307
	Available-for-sale investment securities	$	3,618	$	1,313			$	—			$	4,931
	Mortgage loans held for sale	$	—	$	148			$	—			$	148
	Interest rate lock commitments	$	—	$	—			$	4			$	4
	Forward delivery contracts	—		5				—				5
	Other derivative financial instruments	—		70				—				70
	Derivative financial instruments	$	—	$	75			$	4			$	79
	Liabilities
	Forward delivery contracts	$	—	$	1			$	—			$	1
	Other derivative financial instruments	—		6				—				6
	Derivative financial instruments	$	—	$	7			$	—			$	7
	There were no transfers between Levels 1 and 2 within the fair value hierarchy for the three months ended March 31, 2014 and 2013.
	Available-for-Sale Investment Securities
	Investment securities classified as available-for-sale consist of U.S. Treasury and government agency securities, residential mortgage-backed securities, and credit card asset-backed securities issued by other financial institutions. The fair value estimates of investment securities classified as Level 1, consisting of U.S. Treasury and government agency securities, are determined based on quoted market prices for the same or similar securities. The Company classifies all other available-for-sale investment securities as Level 2, the fair value estimates of which are primarily obtained from pricing services, where fair values are estimated using pricing models based on observable market inputs or recent trades of similar securities. The fair value estimates of mortgage-backed and credit card asset-backed securities are based on the best information available. This data may consist of observed market prices, broker quotes or discounted cash flow models that incorporate assumptions such as benchmark yields, issuer spreads, prepayment speeds, credit ratings and losses, the priority of which may vary based on availability of information.
	The Company validates the fair value estimates provided by the pricing services primarily by comparison to valuations obtained through other pricing sources. The Company evaluates pricing variances amongst 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 March 31, 2014, amounts reported in residential mortgage-backed securities reflect government-rated obligations issued by Fannie Mae, Freddie Mac and Ginnie Mae with a par value of $1.5 billion, a weighted-average coupon of 2.79% and a weighted-average remaining maturity of four years.
	Mortgage Loans Held for Sale and Related Derivative Instruments
	The Company enters into commitments with consumers to originate mortgage loans at a specified interest rate, known as interest rate lock commitments (“IRLCs”). The Company reports IRLCs as derivative instruments at fair value with changes in fair value being recorded in other income. IRLCs and mortgage loans held for sale under certain loan programs are hedged in aggregate using “to be announced mortgage-backed securities” (“TBA MBS”). IRLCs and mortgage loans held for sale under loan programs that generally have lower volume are hedged on an individual loan level using best-efforts forward delivery contracts.
	Fair values for each of these instruments are determined using quantitative risk models. The Company has various monitoring processes in place to validate these valuations, including valuations of Level 3 assets. Valuation results are reviewed in comparison to expected results, recent activity, and historical trends. Any significant or unusual fluctuations in value are analyzed.
	•	Mortgage loans held for sale. Valuations of mortgage loans held for sale are based on the loan amount, note rate, loan program, expected sale date of the loan and, most significantly, investor pricing tables stratified by product, note rate and term, adjusted for current market conditions. Mortgage loans held for sale are classified as Level 2 as the investor pricing tables used to value them are an observable input. Impaired mortgage loans held for sale are classified as Level 3 as loss severity is an unobservable input used in valuation. The Company recognizes interest income separately from changes in fair value.
	•	Interest rate lock commitments. IRLCs for loans to be sold to investors using a mandatory or assignment of trade method derive their base value from an underlying loan type with similar characteristics using the TBA MBS market, which is actively quoted and easily validated through external sources. The data inputs used in this valuation include, but are not limited to, loan type, underlying loan amount, note rate, loan program, and commitment term. IRLCs for loans to be sold to investors on a best-efforts basis derive their base value from the value of the underlying loans using investor pricing tables stratified by product, note rate and term, adjusted for current market conditions. These valuations are adjusted at the loan level to consider the servicing release premium and loan pricing adjustments specific to each loan. For all IRLCs, this base value is then adjusted for the anticipated loan funding probability, or pull through rate. The anticipated loan funding probability is an unobservable input based on historical experience, which results in classification of IRLCs as Level 3.
	•	Forward delivery contracts. Under the Company's risk management policy, the Company economically hedges the changes in fair value of IRLCs and mortgage loans held for sale caused by changes in interest rates by using TBA MBS and entering into best-efforts forward delivery contracts. These hedging instruments are recorded at fair value with changes in fair value recorded in other income. TBA MBS used to hedge both IRLCs and loans held for sale are valued based primarily on observable inputs related to characteristics of the underlying MBS stratified by product, coupon and settlement date. Therefore, these derivatives are classified as Level 2. Best-efforts forward delivery contracts are valued based on investor pricing tables, which are observable inputs, stratified by product, note rate, and term, adjusted for current market conditions. An anticipated loan funding probability is applied to value best-efforts contracts hedging IRLCs, which results in the classification of these contracts as Level 3. The current base loan price and, for best-efforts contracts hedging IRLCs, the anticipated loan funding probability, are the most significant assumptions affecting the value of the best-efforts contracts. The best-efforts forward delivery contracts hedging loans held for sale are classified as Level 2, so such contracts are transferred from Level 3 to Level 2 at the time the underlying loan is originated. For the purposes of the tables below, we refer to TBA MBS and best-efforts forward delivery contracts as forward delivery contracts.
	Other Derivative Financial Instruments
	The Company's other derivative financial instruments consist of interest rate swaps and foreign exchange forward contracts. The fair value of these instruments is estimated by a third-party valuation service that uses proprietary pricing models, where certain inputs to those models are 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 uses 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 are based on an expectation of future interest rates derived from 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 currency instruments are valued 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 amongst 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 to any changes to the valuation techniques performed by proprietary pricing models prior to implementation, working closely with the third-party valuation service, and reviews the control objectives of the service 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 under the Fair Value Option
	The Company has elected to account for mortgage loans held for sale at fair value. Electing the fair value option allows a better offset of the changes in fair values of the loans and the forward delivery contracts used to economically hedge them without the burden of complying with the requirements for hedge accounting. At March 31, 2014 and December 31, 2013, the aggregate unpaid principal balance of loans held for sale for which the fair value option had been elected was $129 million and $146 million, respectively. At March 31, 2014 and December 31, 2013, the same loans had a fair value of $133 million and $148 million, respectively. For the three months ended March 31, 2014, and 2013, respectively, $5 million of losses and $6 million of gains from fair value adjustments on mortgage loans held for sale were recorded in other revenue on the condensed consolidated statements of income.
	Level 3 Financial Instruments Only
	Changes in Level 3 Assets and Liabilities Measure at Fair Value on a Recurring Basis
The following tables provide changes in the Company’s Level 3 assets and liabilities measured at fair value on a recurring basis (dollars in millions):
For the Three Months Ended March 31, 2014
	Balance at December 31, 2013		Transfers into			Transfers out of Level 3			Total Net Gains included in Earnings			Purchases			Sales		Settlements	Transfers of IRLCs to Closed Loans		Balance at March 31, 2014
			Level 3
Interest rate lock commitments	$	4	—			—			18			—			—		—	(17	)	$	5
Forward delivery contracts	$	—	—			(1	)		1			—			—		—	—		$	—
Mortgage loans held for sale	$	—	1			—			—			—			(1	)	—	—		$	—
For the Three Months Ended March 31, 2013
	Balance at December 31, 2012		Transfers into			Transfers out of Level 3			Total Net Gains included in Earnings			Purchases			Sales		Settlements	Transfers of IRLCs to Closed Loans		Balance at March 31, 2013
			Level 3
Interest rate lock commitments	$	12	—			—			48			—			—		3	(49	)	$	14
Mortgage loans held for sale	$	—	1			—			—			—			—		—	—		$	1
Unobservable Inputs and Sensitivities
The following table presents information about significant unobservable inputs related to the Company's Level 3 financial assets and liabilities measured at fair value on a recurring and non-recurring basis at the end of the current period (dollars in millions):
	Fair Value		Valuation		Significant		Ranges of Inputs						Weighted Average(1)
			Technique		Unobservable
March 31, 2014					Input		Low			High
Interest rate lock commitments	$	5	Quantitative risk models		Loan funding probability		8	%		100	%		59	%
-1	Weighted averages are calculated using notional amounts for derivative instruments.
The anticipated loan funding probability represents the Company's expectation regarding the percentage of IRLCs that will ultimately be funded. Generally, an increase in the anticipated loan funding probability would result in an increase in the magnitude of fair value measurements.
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 and other intangible assets. For these assets, measurement at fair value in periods subsequent to the initial recognition of the assets is applicable if one or more of the assets is determined to be impaired. During the three months ended March 31, 2014 and 2013, the Company had no material impairments related to these assets.
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):
	Quoted Prices in Active Markets		Significant				Significant				Total				Carrying
	for Identical		Other				Unobservable								Value
	Assets (Level 1)		Observable				Inputs (Level 3)
			Inputs (Level 2)
Balance at March 31, 2014
Assets
U.S Treasury securities	$	1	$	—			$	—			$	1			$	1
States and political subdivisions of states	—		10				—				10				10
Residential mortgage-backed securities - Agency	—		51				—				51				51
Held-to-maturity investment securities	$	1	$	61			$	—			$	62			$	62
Cash and cash equivalents	$	8,731	$	—			$	—			$	8,731			$	8,731
Restricted cash	$	1,163	$	—			$	—			$	1,163			$	1,163
Net loan receivables(1)	$	—	$	—			$	49,785			$	49,785			$	62,128
Accrued interest receivables	$	—	$	560			$	—			$	560			$	560
Liabilities
Deposits	$	—	$	45,232			$	—			$	45,232			$	44,984
Short-term borrowings	$	—	$	124			$	—			$	124			$	124
Long-term borrowings - owed to securitization investors	$	—	$	14,731			$	1,853			$	16,584			$	16,295
Other long-term borrowings	$	—	$	4,410			$	1			$	4,411			$	3,887
Accrued interest payables	$	—	$	129			$	—			$	129			$	129
Balance at December 31, 2013
Assets
U.S Treasury securities	$	1	$	—			$	—			$	1			$	1
States and political subdivisions of states	—		14				—				14				15
Residential mortgage-backed securities - Agency	—		43				—				43				44
Held-to-maturity investment securities	$	1	$	57			$	—			$	58			$	60
Cash and cash equivalents	$	6,554	$	—			$	—			$	6,554			$	6,554
Restricted cash	$	182	$	—			$	—			$	182			$	182
Net loan receivables(1)	$	—	$	—			$	64,968			$	64,968			$	63,975
Accrued interest receivables	$	—	$	556			$	—			$	556			$	556
Liabilities
Deposits	$	—	$	45,231			$	—			$	45,231			$	44,959
Short-term borrowings	$	—	$	140			$	—			$	140			$	140
Long-term borrowings - owed to securitization investors	$	—	$	15,312			$	1,971			$	17,283			$	16,986
Other long-term borrowings	$	—	$	3,934			$	1			$	3,935			$	3,488
Accrued interest payables	$	—	$	117			$	—			$	117			$	117
-1	Net loan receivables exclude mortgage loans held for sale that are measured at fair value on a recurring basis.
The fair values of these financial assets and liabilities, which are not carried at fair value on the condensed consolidated statements of financial condition, were determined by applying the fair value provisions discussed herein. The use of different assumptions or estimation techniques may have a material effect on these estimated fair value amounts. The following describes the valuation techniques of these financial instruments measured at other than fair value.
Cash and Cash Equivalents
The carrying value of cash and cash equivalents approximates fair value due to the low level of risk these assets present to the Company as well as the relatively liquid nature of these assets, particularly given their short maturities.
Restricted Cash
The carrying value of restricted cash approximates fair value due to the low level of risk these assets present to the Company as well as the relatively liquid nature of these assets, particularly given their short maturities.
Held-to-Maturity Investment Securities
Held-to-maturity investment securities consist of residential mortgage-backed securities issued by agencies and municipal bonds. The fair value of residential mortgage-backed securities included in the held-to-maturity portfolio is estimated similarly to residential mortgage-backed securities carried at fair value on a recurring basis discussed herein. Municipal bonds are valued based on quoted market prices for the same or similar securities.
Total Loan Portfolio
The Company's loan receivables are comprised of credit card and installment loans, including the PCI student loans. Fair value estimates are derived utilizing discounted cash flow analyses, the calculations of which are performed on groupings of loan receivables that are similar in terms of loan type and characteristics. Inputs to the cash flow analysis of each grouping consider recent pre-payment and interest accrual trends and leverage forecasted loss estimates. The expected future cash flows, derived through the cash flow analysis, of each grouping are discounted at rates at which similar loans within each grouping could be originated under current market conditions. Significant inputs to the fair value measurement of the loan portfolio are unobservable, and as such are classified as Level 3.
Accrued Interest Receivable
The carrying value of accrued interest receivable, which is included in other assets on the statement of financial condition, approximates fair value as it is short term in nature and is due in less than one year.
Deposits
The carrying values of money market deposits, savings deposits and demand deposits approximate fair value due to the potentially liquid nature of these deposits. For time deposits for which readily available market rates do not exist, fair values are estimated by discounting expected future cash flows using market rates currently offered for deposits with similar remaining maturities.
Short-Term Borrowings
The carrying values of short-term borrowings approximate fair value as they are short term in nature and have maturities of less than one year.
Long-Term Borrowings-Owed to Securitization Investors
Fair values of long-term borrowings owed to credit card securitization investors are determined utilizing quoted market prices of the same transactions and, as such, are classified as Level 2. Fair values of long-term borrowings owed to student loan securitization investors are calculated by discounting cash flows using estimated assumptions including, among other things, maturity and market discount rates. A portion of the difference between the carrying value and the fair value of the long-term borrowings owed to student loan securitization investors relates to purchase accounting adjustments recorded in connection with the December 2010 purchase of SLC. Significant inputs to these fair value measurements are unobservable and, as such, are classified as Level 3.
Other Long-Term Borrowings
Fair values of other long-term borrowings, consisting of subordinated debt and unsecured debt, are determined utilizing current observable market prices for those transactions and, as such, are classified as Level 2. A portion of the difference between the carrying value and the fair value of the subordinated debt relates to the cash premiums paid in connection with the second and fourth quarter of the 2012 fiscal year debt exchanges as discussed in further detail in Note 6: Long-Term Borrowings. Fair values of other long-term borrowing for which there are no observable market transactions, namely capitalized leases, are determined by discounting cash flows of future interest accruals at market rates currently offered for borrowings with similar credit risks, remaining maturities and repricing terms. As the significant inputs to these fair value measurements are unobservable, they are classified as Level 3.
Accrued Interest Payable
The carrying value of the Company's accrued interest payable, which is included in other liabilities on the statement of financial condition, approximates fair value as it is short term in nature and is payable in less than one year.

Derivatives_and_Hedging_Activi

Derivatives and Hedging Activities	3 Months Ended
	Mar. 31, 2014
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 interest rate movements and other identified risks are not designated as hedges and do not qualify for hedge accounting.
	Derivatives may give rise to counterparty credit risk, which generally is addressed 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 prior to engaging in any transaction with the Company. Counterparties are monitored on a regular basis by the Company 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, the Company considers collateral and legally enforceable master netting agreements that mitigate credit exposure to 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 13: Fair Value Measurements and Disclosures for a description of the valuation methodologies of derivatives. Total derivative asset and liabilities are adjusted on an aggregate basis to take into consideration the effects of cash collateral receivable and payable. Cash collateral receivable and payable balances are recorded in other assets and deposits, respectively, in the condensed consolidated statement of financial condition. Collateral amounts recorded in the condensed consolidated statement of financial condition are based on the net collateral receivable or payable 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 fluctuations in foreign exchange rates on investments in foreign entities are referred to as net investment 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 changes in interest rates related to future cash flows resulting from interest receipts on credit card loan receivables, and from interest payments on credit card securitized debt and deposits. The Company's cash flow hedges related to credit card loan receivables were for an initial maximum period of three years, with none outstanding as of March 31, 2014. The Company's outstanding cash flow hedges are for an initial maximum period of five years for securitized debt and seven years for deposits. The derivatives are designated as hedges of the risk of changes in cash flows on the Company's LIBOR or Federal Funds rate-based interest payments, and qualify for hedge accounting in accordance with ASC Topic 815, Derivatives and Hedging (“ASC 815”).
	The effective portion of the change in the fair value of derivatives designated as cash flow hedges is recorded in other comprehensive income and is subsequently reclassified into earnings in the period that the hedged forecasted cash flows affect earnings. The ineffective portion of the change in fair value of the derivative, if any, is recognized directly in earnings. Amounts reported in accumulated other comprehensive income related to derivatives at March 31, 2014 will be reclassified to interest expense as interest payments are made on certain of the Company's floating rate securitized debt or deposits. During the next 12 months, the Company estimates it will reclassify $30 million of pretax losses to interest expense related to its derivatives designated as cash flow hedges.
	Net Investment Hedges
	The Company is exposed to fluctuations in foreign exchange rates on investments it holds in foreign entities with a functional currency other than the U.S. dollar. The Company uses foreign exchange forward contracts to hedge its exposure to changes in foreign exchange rates on its net investment in Diners Club Italy. Foreign exchange forward contracts utilized by the Company involve fixing the U.S. dollar-euro exchange rate for delivery of a specified amount of foreign currency on a specified date. These derivatives are designated as net investment hedges, with the effective portion of changes in the fair value of the derivatives reported in other comprehensive income as part of the cumulative translation adjustment. The ineffective portion of the change in fair value of the derivatives, if any, is recognized directly in earnings. Amounts are reclassified out of accumulated other comprehensive income into earnings when the hedged net investment is either sold or substantially liquidated.
	Fair Value Hedges
	The Company is exposed to changes in fair value of certain of its fixed rate debt obligations due to changes in interest rates. During the three months ended March 31, 2014, the Company used interest rate swaps to manage its exposure to changes in fair value of certain fixed rate senior notes, securitized debt and interest-bearing brokered deposits attributable to changes in LIBOR, a benchmark interest rate as defined by ASC 815. These interest rate swaps qualify as fair value hedges in accordance with ASC 815. Changes in both (i) the fair values of the derivatives and (ii) the hedged fixed rate senior notes, securitized debt and interest-bearing brokered deposits relating to the risk being hedged were recorded in interest expense. The changes provided substantial offset to one another, with any difference, or ineffectiveness recorded in interest expense. Any basis differences between the fair value and the carrying amount of the hedged item at the inception of the hedging relationship are amortized to interest expense.
	Derivatives Not Designated as Hedges
	Interest Rate Swaps
	The Company may have, from time to time, interest rate swap agreements that are not designated as hedges. As part of its acquisition of SLC, the Company also acquired an interest rate swap related to the securitized debt assumed in the transaction. Such agreements are not speculative and are also used to manage interest rate risk but are not designated for hedge accounting. Changes in the fair value of these contracts are recorded in other income.
	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.
	Forward Delivery Contracts
	The Company economically hedges the changes in fair value of IRLCs and mortgage loans held for sale caused by changes in interest rates by using TBA MBS and entering into best-efforts forward delivery commitments. These derivative instruments are recorded at fair value with changes in fair value recorded in other income.
	Interest Rate Lock Commitments
	The Company enters into commitments with consumers to originate residential mortgage loans at a specified interest rate. The Company reports IRLCs that relate to the origination of mortgage loans that will be held for sale as derivative instruments at fair value with changes in fair value recorded in other income.
	The following table summarizes the fair value (including accrued interest) and related outstanding notional amounts of derivative instruments and indicates where within the statement of financial condition each is reported (dollars in millions):
		March 31, 2014												December 31, 2013
								Statement of Financial Position Location								Statement of Financial Position Location
		Notional				Number of		Other			Accrued Expenses  and Other Liabilities (At Fair Value)			Notional		Other			Accrued
		Amount				Transactions		Assets						Amount		Assets			Expenses  and
								(At Fair								(At Fair			Other
								Value)								Value)			Liabilities
																			(At Fair
																			Value)
	Derivatives designated as hedges:
	Interest rate swaps—cash flow hedge	$	2,950			6		$	13		$	1		$	2,650	$	18		$	—
	Interest rate swaps—fair value hedge	$	6,686			218		54			6			$	7,138	52			6
	Foreign exchange forward contract - net investment hedge(1)	$	33			1		—			—			$	35	—			—
	Derivatives not designated as hedges:
	Foreign exchange forward contracts(2)	$	43			9		—			—			$	44	—			—
	Interest rate swap(3)	$	446			1		—			—			$	796	—			—
	Forward delivery contracts	$	560			453		1			1			$	693	5			1
	Interest rate lock commitments(3)	$	302			1,365		5			—			$	235	4			—
	Total gross derivative assets / liabilities(4)							73			8					79			7
	Less: Collateral receivable / payable(5)							(57		)	(8		)			(61		)	(7		)
	Total net derivative assets / liabilities							$	16		$	—				$	18		$	—
	-1	The foreign exchange forward contract has a notional amount of EUR 24 million and EUR 26 million as of March 31, 2014 and December 31, 2013, respectively.
	-2	The foreign exchange forward contracts have notional amounts of EUR 21 million, GBP 4 million, SGD 2 million, and CHF 6 million as of March 31, 2014, and EUR 20 million, GBP 6 million, SGD 1 million, CHF 5 million as of December 31, 2013.
	-3	Interest rate swaps not designated as hedges and interest rate lock commitments do not have associated master netting arrangements.
	-4	In addition to the derivatives disclosed in the table, the Company had one outstanding forward contract to purchase when-issued mortgage-backed securities as part of our community reinvestment initiatives. This forward contract had a notional amount of $32 million and $40 million and immaterial fair values as of March 31, 2014 and December 31, 2013, respectively.
	-5	Collateral amounts, which consist of both cash and investment securities, are limited to the related derivative asset/liability balance and do not include excess collateral received/pledged.
	The following table summarizes the impact of the derivative instruments on income, and indicates where within the consolidated statements of income such impact is reported for the period (dollars in millions):
				For the Three Months Ended March 31,
		Location		2014			2013
	Derivatives designated as hedges:
	Interest rate swaps—cash flow hedges:
	Total losses recognized in other comprehensive income after amounts reclassified into earnings, pre-tax	Other Comprehensive		$	(6	)	$	(2	)
		Income
	Total losses recognized in other comprehensive income			$	(6	)	$	(2	)
	Amount reclassified from other comprehensive income into income	Interest Income		$	—		$	2
	Amount reclassified from other comprehensive income into income	Interest Expense		(7		)	—
	Interest rate swaps—fair value hedges:
	Interest expense—ineffectiveness			(2		)	(8		)
	Interest expense—other			10			10
	Gain (loss) on interest rate swaps	Interest Expense		8			2
	Interest expense—ineffectiveness			3			9
Interest expense—other			3			(1		)
Gain on hedged item	Interest Expense		6			8
Total gains recognized in income			$	7		$	12
Derivatives not designated as hedges:
Gain on forward contracts	Other Income		$	—		$	2
Loss on interest rate swaps	Other Income		(1		)	—
Loss on forward delivery contracts	Other Income		(3		)	(1		)
Gain on interest rate lock commitments	Other Income		18			48
Total gains on derivatives not designated as hedges recognized in income			$	14		$	49
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, foreign exchange forward contracts, and forward delivery 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 these derivatives held with that counterparty. The Company may also be required to post collateral with a counterparty for its fair value and cash flow hedge interest rate swaps depending on the credit rating it or Discover Bank receives from specified major credit rating agencies. Collateral receivable or payable amounts are not offset against the fair value of these derivatives, but are recorded separately in other assets or deposits.
As of March 31, 2014, DFS had a right to reclaim $4 million of cash collateral that had been posted (net of amounts required to be posted by the counterparty) because the credit rating of the Company did not meet specified thresholds. At March 31, 2014, Discover Bank’s credit rating met specified thresholds set by its counterparties. However, if Discover Bank’s credit rating is reduced by one ratings notch, Discover Bank would be required to post additional collateral, which would have been $107 million as of March 31, 2014.
The Company also has agreements with certain of its derivative counterparties that contain a provision where if the Company defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then the Company could also be declared in default on its derivative obligations.

Segment_Disclosures

Segment Disclosures	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Segment Disclosures	'
	Segment Disclosures
	The Company’s business activities are managed in two segments: Direct Banking and Payment Services.
	•	Direct Banking: The Direct Banking segment includes Discover-branded credit cards issued to individuals and small businesses and other consumer products and services, including home loans, personal loans, student loans, home equity loans, prepaid cards and other consumer lending and deposit products. The majority of Direct Banking revenues relate to interest income earned on each of the 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 automated teller machine, debit and electronic funds transfer network; Diners Club, a global payments network; and the Company’s network partners business, which includes credit, debit and prepaid cards issued on the Discover Network by third parties. This segment also includes the business operations of Diners Club Italy, which primarily consist of issuing Diners Club charge cards. The majority of Payment Services revenues relate to transaction processing revenue from PULSE and royalty and licensee revenue (included in other income) from Diners Club.
	The business segment reporting provided to and used by the Company’s chief operating decision maker is prepared using the following principles and allocation conventions:
	•	The Company aggregates operating segments when determining reporting segments.
	•	Corporate overhead is not allocated between segments; all corporate overhead is included in the Direct Banking segment.
	•	Through its operation of the Discover Network, the Direct Banking segment incurs fixed marketing, servicing and infrastructure costs that are not specifically allocated among the segments.
	•	The assets of the Company are not allocated among the operating segments in the information reviewed by the Company’s chief operating decision maker.
	•	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 chief operating decision maker.
	The following table presents segment data for the period (dollars in millions):
		Direct		Payment		Total
		Banking		Services
	For the Three Months Ended March 31, 2014
	Interest income
	Credit card	$	1,537	$	—	$	1,537
	Private student loans	73		—		73
	PCI student loans	68		—		68
	Personal loans	132		—		132
	Other	23		—		23
	Total interest income	1,833		—		1,833
	Interest expense	270		—		270
	Net interest income	1,563		—		1,563
	Provision for loan losses	270		2		272
	Other income	436		79		515
	Other expense	735		49		784
	Income before income tax expense	$	994	$	28	$	1,022
	For the Three Months Ended March 31, 2013
	Interest income
	Credit card	$	1,451	$	—	$	1,451
	Private student loans	58		—		58
	PCI student loans	70		—		70
	Personal loans	103		—		103
	Other	26		—		26
	Total interest income	1,708		—		1,708
	Interest expense	298		—		298
	Net interest income	1,410		—		1,410
	Provision for loan losses	159		—		159
	Other income	495		87		582
	Other expense	713		40		753
	Income before income tax expense	$	1,033	$	47	$	1,080

Subsequent_Events

Subsequent Events	3 Months Ended
	Mar. 31, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	Subsequent Events
	The Company has evaluated events and transactions that have occurred subsequent to March 31, 2014 and determined there were no subsequent events that would require recognition or disclosure in the consolidated financial statements.

Background_and_Basis_of_Presen1

Background and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation and Significant Accounting Policies	'
	The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“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 which are necessary for a fair presentation of the 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.
Fair Value of Financial Instruments	'
	The fair values of these financial assets and liabilities, which are not carried at fair value on the condensed consolidated statements of financial condition, were determined by applying the fair value provisions discussed herein. The use of different assumptions or estimation techniques may have a material effect on these estimated fair value amounts. The following describes the valuation techniques of these financial instruments measured at other than fair value.
	Cash and Cash Equivalents
	The carrying value of cash and cash equivalents approximates fair value due to the low level of risk these assets present to the Company as well as the relatively liquid nature of these assets, particularly given their short maturities.
	Restricted Cash
	The carrying value of restricted cash approximates fair value due to the low level of risk these assets present to the Company as well as the relatively liquid nature of these assets, particularly given their short maturities.
	Held-to-Maturity Investment Securities
	Held-to-maturity investment securities consist of residential mortgage-backed securities issued by agencies and municipal bonds. The fair value of residential mortgage-backed securities included in the held-to-maturity portfolio is estimated similarly to residential mortgage-backed securities carried at fair value on a recurring basis discussed herein. Municipal bonds are valued based on quoted market prices for the same or similar securities.
	Total Loan Portfolio
	The Company's loan receivables are comprised of credit card and installment loans, including the PCI student loans. Fair value estimates are derived utilizing discounted cash flow analyses, the calculations of which are performed on groupings of loan receivables that are similar in terms of loan type and characteristics. Inputs to the cash flow analysis of each grouping consider recent pre-payment and interest accrual trends and leverage forecasted loss estimates. The expected future cash flows, derived through the cash flow analysis, of each grouping are discounted at rates at which similar loans within each grouping could be originated under current market conditions. Significant inputs to the fair value measurement of the loan portfolio are unobservable, and as such are classified as Level 3.
	Accrued Interest Receivable
	The carrying value of accrued interest receivable, which is included in other assets on the statement of financial condition, approximates fair value as it is short term in nature and is due in less than one year.
	Deposits
	The carrying values of money market deposits, savings deposits and demand deposits approximate fair value due to the potentially liquid nature of these deposits. For time deposits for which readily available market rates do not exist, fair values are estimated by discounting expected future cash flows using market rates currently offered for deposits with similar remaining maturities.
	Short-Term Borrowings
	The carrying values of short-term borrowings approximate fair value as they are short term in nature and have maturities of less than one year.
	Long-Term Borrowings-Owed to Securitization Investors
	Fair values of long-term borrowings owed to credit card securitization investors are determined utilizing quoted market prices of the same transactions and, as such, are classified as Level 2. Fair values of long-term borrowings owed to student loan securitization investors are calculated by discounting cash flows using estimated assumptions including, among other things, maturity and market discount rates. A portion of the difference between the carrying value and the fair value of the long-term borrowings owed to student loan securitization investors relates to purchase accounting adjustments recorded in connection with the December 2010 purchase of SLC. Significant inputs to these fair value measurements are unobservable and, as such, are classified as Level 3.
	Other Long-Term Borrowings
	Fair values of other long-term borrowings, consisting of subordinated debt and unsecured debt, are determined utilizing current observable market prices for those transactions and, as such, are classified as Level 2. A portion of the difference between the carrying value and the fair value of the subordinated debt relates to the cash premiums paid in connection with the second and fourth quarter of the 2012 fiscal year debt exchanges as discussed in further detail in Note 6: Long-Term Borrowings. Fair values of other long-term borrowing for which there are no observable market transactions, namely capitalized leases, are determined by discounting cash flows of future interest accruals at market rates currently offered for borrowings with similar credit risks, remaining maturities and repricing terms. As the significant inputs to these fair value measurements are unobservable, they are classified as Level 3.
	Accrued Interest Payable
	The carrying value of the Company's accrued interest payable, which is included in other liabilities on the statement of financial condition, approximates fair value as it is short term in nature and is payable in less than one year.

Investments_Tables

Investments (Tables)	3 Months Ended
	Mar. 31, 2014
Investments, Debt and Equity Securities [Abstract]	'
Schedule of Investment Securities	'
	The Company’s investment securities consist of the following (dollars in millions):
		March 31,			December 31,
		2014			2013
	U.S. Treasury securities(1)	$	1,343		$	2,058
	U.S. government agency securities	1,047			1,561
	States and political subdivisions of states	10			15
	Other securities:
	Credit card asset-backed securities of other issuers	—			6
	Residential mortgage-backed securities - Agency(2)	1,564			1,351
	Total other securities	1,564			1,357
	Total investment securities	$	3,964		$	4,991
	-1	Includes $7 million and $9 million of U.S. Treasury securities that have been pledged as swap collateral in lieu of cash as of March 31, 2014 and December 31, 2013, respectively.
	-2	Consists of residential mortgage-backed securities issued by Fannie Mae, Freddie Mac and 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
		Cost			Unrealized			Unrealized
					Gains			Losses
	31-Mar-14
	Available-for-Sale Investment Securities(1)
	U.S. Treasury securities	$	1,320		$	22		$	—			$	1,342
	U.S. government agency securities	1,025			22			—				1,047
	Residential mortgage-backed securities - Agency	1,523			3			(13		)		1,513
	Total available-for-sale investment securities	$	3,868		$	47		$	(13	)		$	3,902
	Held-to-Maturity Investment Securities(2)
	U.S. Treasury securities(3)	$	1		$	—		$	—			$	1
	States and political subdivisions of states	10			—			—				10
	Residential mortgage-backed securities - Agency(4)	51			—			—				51
	Total held-to-maturity investment securities	$	62		$	—		$	—			$	62
	31-Dec-13
	Available-for-Sale Investment Securities(1)
	U.S. Treasury securities	$	2,030		$	27		$	—			$	2,057
	U.S. government agency securities	1,535			26			—				1,561
	Credit card asset-backed securities of other issuers	6			—			—				6
	Residential mortgage-backed securities - Agency	1,329			—			(22		)		1,307
	Total available-for-sale investment securities	$	4,900		$	53		$	(22	)		$	4,931
	Held-to-Maturity Investment Securities(2)
	U.S. Treasury securities(3)	$	1		$	—		$	—			$	1
	States and political subdivisions of states	15			—			(1		)		14
	Residential mortgage-backed securities - Agency(4)	44			—			(1		)		43
	Total held-to-maturity investment securities	$	60		$	—		$	(2	)		$	58
	-1	Available-for-sale investment securities are reported at fair value.
	-2	Held-to-maturity investment securities are reported at amortized cost.
	-3	Amount represents securities pledged as collateral to a government-related merchant for which transaction settlement occurs beyond the normal 24-hour period.
	-4	Amounts represent residential mortgage-backed securities that were classified as held-to-maturity as they were entered into as a part of the Company's community reinvestment initiatives.
Schedule of Fair Value of Securities in a Continuous Unrealized Loss Position for Less Than 12 Months and More Than 12 Months	'
	The following table provides information about 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		Less than 12 months							More than 12 months
		Securities
		in a Loss
		Position		Fair			Unrealized				Fair			Unrealized
				Value			Losses				Value			Losses
	At March 31, 2014
	Available-for-Sale Investment Securities
	Residential mortgage-backed securities - Agency	22		$	999		$	(12	)		$	47		$	(1	)
	Held-to-Maturity Investment Securities
	State and political subdivisions of states	4		$	5		$	—			$	3		$	—
	Residential mortgage backed securities - Agency	5		$	29		$	—			$	—		$	—
	At December 31, 2013
	Available-for-Sale Investment Securities
	Residential mortgage-backed securities - Agency	23		$	1,097		$	(20	)		$	48		$	(2	)
	Held-to-Maturity Investment Securities
	State and political subdivisions of states	4		$	8		$	(1	)		$	3		$	—
	Residential mortgage backed securities - Agency	2		$	40		$	(1	)		$	—		$	—
Schedule of Maturities and Weighted Average Yields 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 at the end of the period are provided in the table below (dollars in millions):
		One Year			After One			After Five				After Ten			Total
		or			Year			Years				Years
		Less			Through			Through
					Five Years			Ten Years
	At March 31, 2014
	Available-for-sale—Amortized Cost(1)
	U.S. Treasury securities	$	126		$	1,194		$	—			$	—		$	1,320
	U.S. government agency securities	102			923			—				—			1,025
	Residential mortgage-backed securities - Agency	—			—			422				1,101			1,523
	Total available-for-sale investment securities	$	228		$	2,117		$	422			$	1,101		$	3,868
	Held-to-maturity—Amortized Cost(2)
	U.S. Treasury securities	$	1		$	—		$	—			$	—		$	1
	State and political subdivisions of states	—			—			—				10			10
	Residential mortgage-backed securities - Agency	—			—			—				51			51
	Total held-to-maturity investment securities	$	1		$	—		$	—			$	61		$	62
	Available-for-sale—Fair Values(1)
	U.S. Treasury securities	$	127		$	1,215		$	—			$	—		$	1,342
	U.S. government agency securities	103			944			—				—			1,047
	Residential mortgage-backed securities - Agency	—			—			420				1,093			1,513
	Total available-for-sale investment securities	$	230		$	2,159		$	420			$	1,093		$	3,902
	Held-to-maturity—Fair Values(2)
	U.S. Treasury securities	$	1		$	—		$	—			$	—		$	1
	State and political subdivisions of states	—			—			—				10			10
	Residential mortgage-backed securities - Agency	—			—			—				51			51
	Total held-to-maturity investment securities	$	1		$	—		$	—			$	61		$	62
	-1	Available-for-sale investment securities are reported at fair value.
	-2	Held-to-maturity investment securities are reported at amortized cost.

Loan_Receivables_Tables

Loan Receivables (Tables)	3 Months Ended
	Mar. 31, 2014
Loans and Leases Receivable Disclosure [Abstract]	'
Schedule of Loan Receivables	'
	The Company's classes of receivables within the three portfolio segments are depicted in the table below (dollars in millions):
		March 31,				December 31,
		2014				2013
	Mortgage loans held for sale(1)	$	133			$	148
	Loan portfolio:
	Credit card loans:
	Discover card(2)	50,685				52,952
	Discover business card	194				198
	Total credit card loans	50,879				53,150
	Other loans:
	Personal loans	4,310				4,191
	Private student loans	4,326				3,969
	Other	158				135
	Total other loans	8,794				8,295
	Purchased credit-impaired loans(3)	4,046				4,178
	Total loan portfolio	63,719				65,623
	Total loan receivables	63,852				65,771
	Allowance for loan losses	(1,591		)		(1,648		)
	Net loan receivables	$	62,261			$	64,123
	-1	Substantially all mortgage loans held for sale are pledged as collateral against the warehouse line of credit used to fund consumer residential loans.
	-2	Amounts include $19.6 billion and $20.2 billion underlying investors’ interest in trust debt at March 31, 2014 and December 31, 2013, respectively, and $9.5 billion and $10.9 billion in seller's interest at March 31, 2014 and December 31, 2013, respectively. See Note 4: Credit Card and Student Loan Securitization Activities for further information.
	-3	Amounts include $2.2 billion of loans pledged as collateral against the notes issued from the Student Loan Corporation ("SLC") securitization trusts at March 31, 2014 and December 31, 2013. See Note 4: Credit Card and Student Loan Securitization Activities. Of the remaining $1.8 billion and $2.0 billion at March 31, 2014 and December 31, 2013, respectively, that were not pledged as collateral, approximately $22 million for each period represents loans eligible for reimbursement through an indemnification claim. Discover Bank must purchase such loans from the trust before a claim may be filed.
Schedule of Delinquent and Non-Accruing Loans	'
	Information related to the delinquent and non-accruing loans in the Company’s loan portfolio, which excludes loans held for sale, is shown below by each class of loan receivables except for PCI student loans, which is shown under the heading “— Purchased Credit-Impaired Loans” (dollars in millions):
		30-89 Days				90 or				Total Past				90 or		Total
		Delinquent				More Days				Due				More Days		Non-accruing(1)
						Delinquent								Delinquent
														and
														Accruing
	At March 31, 2014
	Credit card loans:
	Discover card(2)	$	432			$	441			$	873			$	402	$	162
	Discover business card	2				1				3				2		1
	Total credit card loans	434				442				876				404		163
	Other loans:
	Personal loans(3)	21				8				29				7		5
	Private student loans (excluding PCI)(4)	51				26				77				26		—
	Other	1				2				3				—		39
	Total other loans (excluding PCI)	73				36				109				33		44
	Total loan receivables (excluding PCI)	$	507			$	478			$	985			$	437	$	207
	At December 31, 2013
	Credit card loans:
	Discover card(2)	$	464			$	445			$	909			$	406	$	154
	Discover business card	1				2				3				2		1
	Total credit card loans	465				447				912				408		155
	Other loans:
	Personal loans(3)	21				8				29				8		5
	Private student loans (excluding PCI)(4)	48				18				66				18		—
	Other	1				2				3				—		40
	Total other loans (excluding PCI)	70				28				98				26		45
	Total loan receivables (excluding PCI)	$	535			$	475			$	1,010			$	434	$	200
	-1	The Company estimates that the gross interest income that would have been recorded in accordance with the original terms of non-accruing credit card loans was $7 million and $8 million for the three months ended March 31, 2014 and 2013, respectively. The Company does not separately systematically compute the amount of gross interest income that would have been recorded in accordance with the original terms of loans. This amount was estimated based on customers' quarterly average balances and rates prior to non-accrual status.
	-2	Consumer credit card loans that are 90 or more days delinquent and accruing interest include $42 million and $41 million of loans accounted for as troubled debt restructurings at March 31, 2014 and December 31, 2013, respectively.
	-3	Personal loans that are 90 or more days delinquent and accruing interest include $2 million of loans accounted for as troubled debt restructurings at March 31, 2014 and December 31, 2013.
	-4	Private student loans that are 90 or more days delinquent and accruing interest include $3 million of loans accounted for as troubled debt restructurings at March 31, 2014 and December 31, 2013.
Schedule of Net Charge-offs	'
	Information related to the net charge-offs in the Company's loan portfolio, which excludes loans held for sale, is shown below by each class of loan receivables except for PCI student loans, which is shown under the heading "— Purchased Credit-Impaired Loans" (dollars in millions):
		For the Three Months Ended March 31,
		2014							2013
		Net				Net			Net				Net
		Charge-offs				Charge-off			Charge-offs				Charge-off
						Rate							Rate
	Credit card loans:
	Discover card	$	293			2.32	%		$	286			2.36	%
	Discover business card	1				1.76	%		1				2.66	%
	Total credit card loans	294				2.32	%		287				2.36	%
	Other loans:
	Personal loans	21				2.07	%		19				2.3	%
	Private student loans (excluding PCI)	14				1.31	%		7				0.82	%
	Total other loans (excluding PCI)	35				1.67	%		26				1.49	%
	Net charge-offs as a percentage of total loans (excluding PCI)	$	329			2.22	%		$	313			2.25	%
	Net charge-offs as a percentage of total loans (including PCI)	$	329			2.08	%		$	313			2.08	%
Schedule of Credit Risk Profile by FICO Score	'
	The following table provides the most recent FICO scores available for the Company’s customers as a percentage of each class of loan receivables:
		Credit Risk Profile
		by FICO Score
		660 and Above			Less than 660
					or No Score
	31-Mar-14
	Discover card	82	%		18	%
	Discover business card	92	%		8	%
	Personal loans	97	%		3	%
	Private student loans (excluding PCI)(1)	95	%		5	%
	31-Dec-13
	Discover card	83	%		17	%
	Discover business card	92	%		8	%
	Personal loans	97	%		3	%
	Private student loans (excluding PCI)(1)	95	%		5	%
	-1	PCI loans are discussed under the heading "— Purchased Credit-Impaired Loans."
Schedule of Changes in the Allowance for Loan Losses	'
	The following tables provide changes in the Company’s allowance for loan losses (dollars in millions):
		For the Three Months Ended March 31, 2014
		Credit Card				Personal Loans				Student Loans				Other		Total
	Balance at beginning of period	$	1,406			$	112			$	113			$	17	$	1,648
	Additions:
	Provision for loan losses	230				18				23				1		272
	Deductions:
	Charge-offs	(408		)		(24		)		(15		)		—		(447		)
	Recoveries	114				3				1				—		118
	Net charge-offs	(294		)		(21		)		(14		)		—		(329		)
	Balance at end of period	$	1,342			$	109			$	122			$	18	$	1,591
		For the Three Months Ended March 31, 2013
		Credit Card				Personal Loans				Student Loans				Other		Total
	Balance at beginning of period	$	1,613			$	99			$	75			$	1	$	1,788
	Additions:
	Provision for loan losses	127				17				15				—		159
	Deductions:
	Charge-offs	(422		)		(20		)		(7		)		—		(449		)
	Recoveries	135				1				—				—		136
	Net charge-offs	(287		)		(19		)		(7		)		—		(313		)
	Balance at end of period	$	1,453			$	97			$	83			$	1	$	1,634
Schedule of Net Charge-offs of Interest and Fee Revenues on Loan Receivables	'
	Net charge-offs of principal are recorded against the allowance for loan losses, as shown in the table above. Information regarding net charge-offs of interest and fee revenues on credit card and other loans is as follows (dollars in millions):
		For the Three Months Ended March 31,
		2014				2013
	Interest and fees accrued subsequently charged off, net of recoveries (recorded as a reduction of interest income)	$	72			$	77
	Fees accrued subsequently charged off, net of recoveries (recorded as a reduction to other income)	$	17			$	16
Schedule of Allowance for Loan Losses and Recorded Investment in its Loan Portfolio by Impairment Methodology	'
	The following tables provide additional detail of the Company’s allowance for loan losses and recorded investment in its loan portfolio (which excludes loans held for sale) by impairment methodology (dollars in millions):
		Credit Card				Personal				Student				Other		Total
						Loans				Loans				Loans
	At March 31, 2014
	Allowance for loans evaluated for impairment as:
	Collectively evaluated for impairment in accordance with ASC 450-20	$	1,164			$	104			$	84			$	1	$	1,353
	Evaluated for impairment in accordance with	178				5				10				17		210
	ASC 310-10-35(1)(2)
	Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				28				—		28
	Total allowance for loan losses	$	1,342			$	109			$	122			$	18	$	1,591
	Recorded investment in loans evaluated for impairment as:
	Collectively evaluated for impairment in accordance with ASC 450-20	$	49,791			$	4,265			$	4,296			$	80	$	58,432
	Evaluated for impairment in accordance with	1,088				45				30				78		1,241
	ASC 310-10-35(1)(2)
	Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				4,046				—		4,046
	Total recorded investment	$	50,879			$	4,310			$	8,372			$	158	$	63,719
	At December 31, 2013
	Allowance for loans evaluated for impairment as:
	Collectively evaluated for impairment in accordance with ASC 450-20	$	1,218			$	109			$	76			$	1	$	1,404
	Evaluated for impairment in accordance with	188				3				9				16		216
	ASC 310-10-35(1)(2)
	Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				28				—		28
	Total allowance for loan losses	$	1,406			$	112			$	113			$	17	$	1,648
	Recorded investment in loans evaluated for impairment as:
	Collectively evaluated for impairment in accordance with ASC 450-20	$	52,027			$	4,160			$	3,941			$	56	$	60,184
	Evaluated for impairment in accordance with	1,123				31				28				79		1,261
	ASC 310-10-35(1)(2)
	Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				4,178				—		4,178
	Total recorded investment	$	53,150			$	4,191			$	8,147			$	135	$	65,623
	-1	Loan receivables evaluated for impairment in accordance with ASC 310-10-35 include credit card loans, personal loans and student loans collectively evaluated for impairment in accordance with ASC Subtopic 310-40, Receivables, which consists of modified loans accounted for as troubled debt restructurings. Other loans are individually evaluated for impairment and generally do not represent troubled debt restructurings.
	-2	The unpaid principal balance of credit card loans was $919 million and $900 million at March 31, 2014 and December 31, 2013, respectively. The unpaid principal balance of personal loans was $44 million and $31 million at March 31, 2014 and December 31, 2013, respectively. The unpaid principal balance of student loans was $28 million and $26 million at March 31, 2014 and December 31, 2013, respectively. All loans accounted for as troubled debt restructurings have a related allowance for loan losses.
Schedule of Troubled Debt Restructurings	'
	Additional information about modified loans classified as troubled debt restructurings is shown below (dollars in millions):
		Average recorded investment in loans				Interest income recognized during period loans were impaired(1)				Gross interest income that would have been recorded with original terms(2)
	For the Three Months Ended March 31, 2014
	Credit card loans
	Modified credit card loans(3)	$	256			$	11			$	1
	Internal programs	$	454			$	3			$	15
	External programs	$	394			$	7			$	3
	Personal loans	$	44			$	1			$	—
	Student loans(4)	$	29			$	1			N/A
	For the Three Months Ended March 31, 2013
	Credit card loans
	Modified credit card loans(3)	$	279			$	13			$	1
	Internal programs	$	490			$	3			$	17
	External programs	$	507			$	10			$	3
	Personal loans	$	22			$	1			$	—
	Student loans(4)	$	18			$	—			N/A
	-1	The Company does not separately track interest income on loans in modification programs. Amounts shown are estimated by applying an average interest rate to the average loans in the various modification programs.
	-2	The Company does not separately track the amount of gross interest income that would have been recorded if the loans in modification programs had not been restructured and interest had instead been recorded in accordance with the original terms. Amounts shown are estimated by applying the difference between the average interest rate earned on non-impaired credit card loans and the average interest rate earned on loans in the modification programs to the average loans in the modification programs.
	-3	This balance is considered impaired, but is excluded from the internal and external program amounts reflected in this table. Represents credit card loans that were modified in troubled debt restructurings, but are no longer enrolled in troubled debt restructuring program due to noncompliance with the terms of the modification or successful completion of a program
	-4	Student loan customers who have been granted a forbearance are not given interest rate reductions.
Schedule of Loans That Entered a Modification Program During the Period	'
	The following table provides information on loans that entered a loan modification program during the period (dollars in millions):
		For the Three Months Ended March 31,
		2014							2013
		Number of Accounts			Balances				Number of Accounts			Balances
	Accounts that entered a loan modification program during the period:
	Credit card:
	Internal programs	12,436			$	81			10,402			$	66
	External programs	8,431			$	44			9,531			$	52
	Personal loans	712			$	8			443			$	6
	Student loans	307			$	4			172			$	4
Schedule of Troubled Debt Restructurings That Subsequently Defaulted	'
	The following table presents the carrying value of loans that experienced a payment default during the period that had been modified in a troubled debt restructuring during the 15 months preceding the end of each period (dollars in millions):
		For the Three Months Ended March 31,
		2014							2013
		Number of Accounts			Aggregated Outstanding Balances Upon Default				Number of Accounts			Aggregated Outstanding Balances Upon Default
	Troubled debt restructurings that subsequently defaulted:
	Credit card:
	Internal programs(1)(2)	2,331			$	14			2,880			$	18
	External programs(1)(2)	1,881			$	8			2,251			$	10
	Personal loans(2)	106			$	1			24			$	—
	Student loans(3)	311			$	5			135			$	3
	-1	The outstanding balance upon default is the loan balance at the end of the month prior to default. Terms revert back to the pre-modification terms for customers who default from a temporary program and charging privileges remain revoked.
	-2	A customer defaults from a modification program after two consecutive missed payments.
	-3	Student loan defaults have been defined as loans that are 60 or more days delinquent.
Schedule of Changes in Accretable Yield for the Acquired Loans	'
	The following table provides changes in accretable yield for the acquired loans during the period (dollars in millions):
		For the Three Months Ended March 31,
		2014				2013
	Balance at beginning of period	$	1,580			$	2,072
	Accretion into interest income	(68		)		(70		)
	Other changes in expected cash flows	—				19
	Balance at end of period	$	1,512			$	2,021
Schedule of Initial Unpaid Principal Balance of Mortgage Loans Sold by Type	'
	The following table provides a summary of the initial unpaid principal balance of mortgage loans sold during the period, by type of loan  (dollars in millions):
		For the Three Months Ended March 31,
		2014							2013
		Amount				%			Amount				%
	Conforming(1)	$	447			89.94	%		$	665			55.51	%
	FHA(2)	48				9.66			533				44.49
	Jumbo(3)	2				0.4			—				—
	Total	$	497			100	%		$	1,198			100	%
	-1	Conforming loans are loans that conform to Government Sponsored Enterprises guidelines.
	-2	FHA loans are loans that are insured by the Federal Housing Administration and are typically made to borrowers with low down payments. The initial loan amount must be within certain limits.
	-3	Jumbo loans are loans with an initial amount larger than the limits set by a Government Sponsored Enterprise.
Schedule of Mortgage Loans Held for Sale	'
	The following table represents the loans held for sale by type of loan (dollars in millions):
		March 31, 2014							December 31, 2013
		Amount				%			Amount				%
	Conforming(1)	$	116			87.22	%		$	136			91.89	%
	FHA(2)	13				9.77			11				7.43
	Jumbo(3)	4				3.01			1				0.68
	Total	$	133			100	%		$	148			100	%
	-1	Conforming loans are loans that conform to Government Sponsored Enterprises guidelines.
	-2	FHA loans are loans that are insured by the Federal Housing Administration and are typically made to borrowers with low down payments. The initial loan amount must be within certain limits.
	-3	Jumbo loans are loans with an initial loan amount larger than the limits set by a Government Sponsored Enterprise.

Credit_Card_and_Student_Loan_S1

Credit Card and Student Loan Securitization Activities (Tables)	3 Months Ended
	Mar. 31, 2014
Variable Interest Entities Disclosure [Abstract]	'
Schedule Of Restricted Credit Card Securitized Assets [Text Block]	'
	The carrying values of these restricted assets, which are presented on the Company’s condensed consolidated statement of financial condition as relating to securitization activities, are shown in the table below (dollars in millions):
		March 31,			December 31,
		2014			2013
	Cash collateral accounts	$	8		$	59
	Collections and interest funding accounts	1,061			31
	Restricted cash	1,069			90
	Investors’ interests held by third-party investors	14,589			15,190
	Investors’ interests held by wholly-owned subsidiaries of Discover Bank	5,033			5,024
	Seller’s interest	9,535			10,898
	Loan receivables(1)	29,157			31,112
	Allowance for loan losses allocated to securitized loan receivables(1)	(779		)	(833		)
	Net loan receivables	28,378			30,279
	Other	37			34
	Carrying value of assets of consolidated variable interest entities	$	29,484		$	30,403
	-1	The Company maintains its allowance for loan losses at an amount sufficient to absorb probable losses inherent in all loan receivables, which includes all loan receivables in the trusts. Therefore, credit risk associated with the transferred receivables is fully reflected on the Company’s balance sheet in accordance with GAAP.
Schedule of Investors' Interests and Related Excess Spreads	'
	The tables below provide information concerning investors’ interests and related excess spreads at the end of the current period (dollars in millions):
	March 31, 2014	Investors’			# of Series
		Interests(1)			Outstanding
	Discover Card Master Trust I	$	168		2
	Discover Card Execution Note Trust (DiscoverSeries notes)	19,454			38
	Total investors’ interests	$	19,622		40
	-1	Investors’ interests include third-party interests and subordinated interests held by wholly-owned subsidiaries of Discover Bank.
		3-Month Rolling
		Average Excess
		Spread(1)
	Group excess spread percentage	13.47	%
	DiscoverSeries excess spread percentage	13.46	%
	-1	DCMT certificates refer to the higher of the Group excess spread or their applicable series excess spread (not shown) and DiscoverSeries notes refer to the higher of the Group or DiscoverSeries excess spread in assessing whether an economic early amortization has been triggered.
Schedule Of Restricted Student Loan Securitized Assets [Text Block]	'
	The carrying values of these restricted assets, which are presented on the Company’s condensed consolidated statement of financial condition as relating to securitization activities, are shown in the table below (dollars in millions):
		March 31,			December 31,
		2014			2013
	Restricted cash	$	91		$	89
	Student loan receivables	2,177			2,248
	Allowance for loan losses allocated to securitized loan receivables(1)	(28		)	(28		)
	Net student loan receivables	2,149			2,220
	Carrying value of assets of consolidated variable interest entities	$	2,240		$	2,309
	-1	The Company maintains its allowance for loan losses at an amount sufficient to absorb probable losses inherent in all loan receivables, which includes all loan receivables in the trusts. Therefore, credit risk associated with the transferred receivables is fully reflected on the Company’s balance sheet in accordance with GAAP.

Deposits_Tables

Deposits (Tables)	3 Months Ended
	Mar. 31, 2014
Deposits [Abstract]	'
Schedule of Interest Bearing Deposit Accounts	'
	A summary of interest-bearing deposit accounts is as follows (dollars in millions):
		March 31,			December 31,
		2014			2013
	Certificates of deposit in amounts less than $100,000(1)	$	20,832		$	21,211
	Certificates of deposit from amounts of $100,000(1) to less than $250,000(1)	4,781			4,860
	Certificates of deposit in amounts of $250,000(1) or greater	1,163			1,180
	Savings deposits, including money market deposit accounts	18,037			17,515
	Total interest-bearing deposits	$	44,813		$	44,766
	Average annual interest rate	1.32		%	1.57		%
	-1	$100,000 represents the basic insurance amount previously covered by the FDIC. Effective July 21, 2010, the basic insurance per depositor was permanently increased to $250,000.
Schedule of Certificates of Deposit Maturities	'
	At the end of the current period, certificates of deposit maturing over the remainder of this year, over each of the next four years, and thereafter were as follows (dollars in millions):
	Year	Amount
	2014	$	9,925
	2015	$	7,444
	2016	$	3,768
	2017	$	2,310
	2018	$	1,728
	Thereafter	$	1,601

LongTerm_Borrowings_Tables

Long-Term Borrowings (Tables)	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Schedule of Long-Term Borrowings and Weighted Average Interest Rates	'
	Long-term borrowings consist of borrowings and capital leases 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 balances outstanding at period end (dollars in millions):
		March 31, 2014				December 31, 2013
		Outstanding		Interest		Outstanding		Interest		Interest Rate Terms	Maturity
				Rate				Rate
	Securitized Debt
	Fixed rate asset-backed securities
	Principal value	$	5,549	1.86	%	$	5,549	1.86	%	Various fixed rates	Various
	(including discount of $1 at March 31, 2014 and December 31, 2013, respectively)										February 2015 - July 2019
	Fair value adjustment(1)	5				5
	Book value	5,554				5,554
	Floating rate asset-backed securities	8,189		0.47	%	9,140		0.46	%	1-month LIBOR(2) +	Various
										15 to 58 basis points	April 2014 - January 2019
	Floating rate asset-backed securities	850		0.4	%	—		—	%	3-month LIBOR(2) +	Feb-17
										20 basis points
	Floating rate asset-backed securities	—		—	%	500		0.44	%	Commercial Paper	Mar-14
										rate + 30 basis points
	Total Discover Card Master Trust I and Discover Card Execution Note Trust	14,593				15,194
	Floating rate asset-backed securities	959		0.48	%	1,005		0.48	%	3-month LIBOR(2) +	Various
	(including discount of $118 and $129 at March 31, 2014 and December 31, 2013)									12 to 45 basis points	January 2019 - July 2036 (3)
	Floating rate asset-backed securities	410		4.25	%	434		4.25	%	Prime rate + 100 basis points	June 2031 (3)
	(including discount of $2 and $3 at March 31, 2014 and December 31, 2013)
	Floating rate asset-backed securities	100		4	%	105		4	%	Prime rate +	July 2042 (3)
	(including premium of $1 at March 31, 2014 and December 31, 2013)									75 basis points
	Floating rate asset-backed securities	233		3.66	%	248		3.66	%	1-month LIBOR(2) +	July 2042 (3)
	(including premium of $3 at March 31, 2014 and December 31, 2013)									350 basis points
	Total SLC Private Student Loan Trusts	1,702				1,792
	Total Long-Term Borrowings—owed to securitization investors	16,295				16,986
	Discover Financial Services (Parent Company)
	Fixed rate senior notes due 2017
	Principal value	400		6.45	%	400		6.45	%	Fixed	Jun-17
	Fair value adjustment(1)	8				13
	Book value	408				413
	Fixed rate senior notes due 2019	78		10.25	%	78		10.25	%	Fixed	Jul-19
	Fixed rate senior notes due 2022	221		5.2	%	219		5.2	%	Fixed	Apr-22
	(including discount of $101 and $103 at March 31, 2014 and December 31, 2013)(4)
	Fixed rate senior notes due 2022	338		3.85	%	335		3.85	%	Fixed	Nov-22
	(including discount of $162 and $165 at March 31, 2014 and December 31, 2013)(5)
	Discover Bank
	Senior bank notes due 2018	750		2	%	750		2	%	Fixed	Feb-18
	Senior bank notes due 2023	994		4.2	%	994		4.2	%	Fixed	Aug-23
	(including discount of $6 at March 31, 2014 and December 31, 2013)
	Senior bank notes due 2026	399		4.25	%	—		—	%	Fixed	Mar-26
	(including discount of $1 at March 31, 2014)
	Subordinated bank notes due 2019	200		8.7	%	200		8.7	%	Fixed	November 2019
	Subordinated bank notes due 2020	498		7	%	498		7	%	Fixed	April 2020
	(including discount of $2 at March 31, 2014 and December 31, 2013)
	Capital lease obligations	1		4.51	%	1		4.51	%	Fixed	Apr-16
	Total long-term borrowings	$	20,182			$	20,474
	-1	The Company uses interest rate swaps to hedge portions of these long-term borrowings against changes in fair value attributable to changes in LIBOR. See Note 14: Derivatives and Hedging Activities.
	-2	London Interbank Offered Rate (“LIBOR”).
	-3	Repayment of this debt is dependent upon the timing of principal and interest payments on the underlying student loans. The dates shown represent final maturity dates.
	-4	Discount primarily relates to $115 million cash premium paid at issuance as part of 2012 private exchange offer to replace higher rate borrowings with borrowings bearing lower interest rates. During the three months ended March 31, 2014 and 2013, respectively, $2 million of the premium paid was amortized and included in interest expense in the condensed consolidated statements of income.
	-5	Discount primarily relates to $176 million cash premium paid at issuance as part of 2012 private exchange offer to replace higher rate borrowings with borrowings bearing lower interest rates. During the three months ended March 31, 2014 and 2013. respectively, $3 million of the premium paid was amortized and included in interest expense in the condensed consolidated statements of income.
Schedule of Long-Term Borrowings Maturities	'
	Long-term borrowings had the following maturities at the end of the current period (dollars in millions):
	Year	Amount
	Due in 2014	$	2,040
	Due in 2015	3,305
	Due in 2016	3,050
	Due in 2017	2,908
	Due in 2018	2,650
	Thereafter	6,229
	Total	$	20,182

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2014
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 income (loss) were as follows (dollars in millions):
		Unrealized Gain (Loss) on Available-for-Sale Investment Securities,			Gain (Loss) on Cash Flow Hedges,			Foreign Currency Translation Adjustments, Net of Tax(1)			Pension and Post Retirement Plan Gain (Loss),			Accumulated Other Comprehensive Income (Loss)
		Net of Tax			Net of Tax						Net of Tax
	Balance at December 31, 2012	$	71		$	3		—			$	(146	)	$	(72	)
	Net change	(11		)	(1		)	—			—			(12		)
	Balance at March 31, 2013	$	60		$	2		—			$	(146	)	$	(84	)
	Balance at December 31, 2013	$	19		$	13		1			$	(101	)	$	(68	)
	Net change	2			(4		)	—			—			(2		)
	Balance at March 31, 2014	$	21		$	9		1			$	(101	)	$	(70	)
	-1	Includes unrealized losses on hedge of net investment in foreign subsidiary, net of tax benefit and net gains on foreign currency translation adjustments.
Schedule of Other Comprehensive Income Before Reclassifications and Amounts Reclassified from AOCI	'
	The table below presents the other comprehensive income (loss) 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 March 31, 2014
	Available-for-Sale Investment Securities:
	Net unrealized holding gains arising during the period	$	7		$	(3	)	$	4
	Amounts reclassified from accumulated other comprehensive income	(4		)	2			(2		)
	Net change	$	3		$	(1	)	$	2
	Cash Flow Hedges:
	Net unrealized losses arising during the period	$	(13	)	$	5		$	(8	)
	Amounts reclassified from accumulated other comprehensive income	7			(3		)	4
	Net change	$	(6	)	$	2		$	(4	)
	For the Three Months Ended March 31, 2013
	Available-for-Sale Investment Securities:
	Net unrealized holding losses arising during the period	$	(14	)	$	5		$	(9	)
	Amounts reclassified from accumulated other comprehensive income	(2		)	—			(2		)
	Net change	$	(16	)	$	5		$	(11	)
	Cash Flow Hedges:
	Amounts reclassified from accumulated other comprehensive income	(2		)	1			(1		)
	Net change	$	(2	)	$	1		$	(1	)

Income_Taxes_Tables

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
Schedule of Reconciliation of the Company's Effective Tax Rate to the U.S. Federal Statutory Income Tax Rate	'
	The following table presents the calculation of the Company's effective income tax rate (dollars in millions, except effective income tax rate):
		For the Three Months Ended March 31,
		2014			2013
	Income before income tax expense	$	1,022		$	1,080
	Income tax expense	$	391		$	407
	Effective income tax rate	38.3		%	37.7		%

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Schedule of Basic and Diluted EPS	'
	The following table presents the calculation of basic and diluted earnings per share ("EPS") (in millions, except per share amounts):
		For the Three Months Ended March 31,
		2014			2013
	Numerator:
	Net income	$	631		$	673
	Preferred stock dividends	(9		)	(9		)
	Net income available to common stockholders	622			664
	Income allocated to participating securities	(4		)	(5		)
	Net income allocated to common stockholders	$	618		$	659
	Denominator:
	Weighted average shares of common stock outstanding	471			496
	Effect of dilutive common stock equivalents	1			1
	Weighted average shares of common stock outstanding and common stock equivalents	472			497
	Basic earnings per common share	$	1.31		$	1.33
	Diluted earnings per common share	$	1.31		$	1.33

Capital_Adequacy_Tables

Capital Adequacy (Tables)	3 Months Ended
	Mar. 31, 2014
Regulatory Capital Requirements [Abstract]	'
Schedule of Minimum and Well-Capitalized Requirements	'
	The following table shows the actual capital amounts and ratios of the Company and the Bank and comparisons of each to the regulatory minimum and “well-capitalized” requirements (dollars in millions):
		Actual				Minimum Capital			Capital Requirements
						Requirements			To Be Classified as
									Well-Capitalized
		Amount		Ratio		Amount		Ratio	Amount		Ratio
	March 31, 2014
	Total capital (to risk-weighted assets)
	Discover Financial Services	$	12,175	18.1	%	$	5,389	≥8.0%	$	6,736	≥10.0%
	Discover Bank	$	10,705	16.1	%	$	5,324	≥8.0%	$	6,655	≥10.0%
	Tier 1 capital (to risk-weighted assets)
	Discover Financial Services	$	10,626	15.8	%	$	2,695	≥4.0%	$	4,042	≥6.0%
	Discover Bank	$	9,166	13.8	%	$	2,662	≥4.0%	$	3,993	≥6.0%
	Tier 1 capital (to average assets)
	Discover Financial Services	$	10,626	13.4	%	$	3,173	≥4.0%	$	3,966	≥5.0%
	Discover Bank	$	9,166	11.7	%	$	3,137	≥4.0%	$	3,921	≥5.0%
	December 31, 2013
	Total capital (to risk-weighted assets)
	Discover Financial Services	$	11,975	17.4	%	$	5,492	≥8.0%	$	6,865	≥10.0%
	Discover Bank	$	10,496	15.5	%	$	5,428	≥8.0%	$	6,785	≥10.0%
	Tier 1 capital (to risk-weighted assets)
	Discover Financial Services	$	10,409	15.2	%	$	2,746	≥4.0%	$	4,119	≥6.0%
	Discover Bank	$	8,941	13.2	%	$	2,714	≥4.0%	$	4,071	≥6.0%
	Tier 1 capital (to average assets)
	Discover Financial Services	$	10,409	13.4	%	$	3,116	≥4.0%	$	3,895	≥5.0%
	Discover Bank	$	8,941	11.6	%	$	3,077	≥4.0%	$	3,847	≥5.0%

Commitments_Contingencies_and_1

Commitments, Contingencies and Guarantees (Tables)	3 Months Ended
	Mar. 31, 2014
Guarantor Obligations [Line Items]	'
Schedule of Lease Commitments	'
	The Company leases various office space and equipment under capital and non-cancelable operating leases, which expire at various dates through 2024. At the end of the current period, future minimum payments on leases with original terms in excess of one year consist of the following (dollars in millions):
		Capitalized		Operating
		Leases		Leases
	2014	$	—	$	12
	2015	1		13
	2016	—		12
	2017	—		10
	2018	—		7
	Thereafter	—		12
	Total minimum lease payments	1		$	66
	Less: Amount representing interest	—
	Present value of net minimum lease payments	$	1
Schedule of Settlement Withholdings and Escrow Deposits	'
	The table below provides information regarding settlement withholdings and escrow deposits, which are recorded in interest-bearing deposit accounts, and accrued expenses and other liabilities on the Company’s condensed consolidated statements of financial condition (dollars in millions):
		March 31,		December 31,
		2014		2013
	Settlement withholdings and escrow deposits	$	21	$	17
Counterparty Settlement Guarantees [Member]	'
Guarantor Obligations [Line Items]	'
Schedule of Maximum Potential Counterparty Exposures Related to Settlement Guarantees and Merchant Chargeback Guarantee	'
	While the Company has some contractual remedies to offset these counterparty settlement exposures (such as letters of credit or pledged deposits), in the event that 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, based on historical transaction volume, would be as follows (dollars in millions):
		March 31,
		2014
	Diners Club:
	Merchant guarantee	$	173
	PULSE:
	ATM guarantee	$	1
Merchant Chargeback Guarantees [Member]	'
Guarantor Obligations [Line Items]	'
Schedule of Maximum Potential Counterparty Exposures Related to Settlement Guarantees and Merchant Chargeback Guarantee	'
	The table below summarizes certain information regarding merchant chargeback guarantees (in millions):
		For the Three Months Ended March 31,
		2014		2013
	Aggregate sales transaction volume(1)	$	28,154	$	27,228
	-1	Represents period transactions processed on the Discover Network for which a potential liability exists that, in aggregate, can differ from credit card sales volume.

Fair_Value_Measurements_and_Di1

Fair Value Measurements and Disclosures (Tables)	3 Months Ended
	Mar. 31, 2014
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 Prices in		Significant				Significant				Total
		Active Markets		Other				Unobservable
		for Identical		Observable				Inputs (Level 3)
		Assets (Level 1)		Inputs (Level 2)
	Balance at March 31, 2014
	Assets
	U.S Treasury securities	$	1,342	$	—			$	—			$	1,342
	U.S government agency securities	1,047		—				—				1,047
	Residential mortgage-backed securities - Agency	—		1,513				—				1,513
	Available-for-sale investment securities	$	2,389	$	1,513			$	—			$	3,902
	Mortgage loans held for sale	$	—	$	133			$	—			$	133
	Interest rate lock commitments	$	—	$	—			$	5			$	5
	Forward delivery contracts	—		1				—				1
	Other derivative financial instruments	—		67				—				67
	Derivative financial instruments	$	—	$	68			$	5			$	73
	Liabilities
	Forward delivery contracts	$	—	$	1			$	—			$	1
	Other derivative financial instruments	—		7				—				7
	Derivative financial instruments	$	—	$	8			$	—			$	8
	Balance at December 31, 2013
	Assets
	U.S Treasury securities	$	2,057	$	—			$	—			$	2,057
	U.S government agency securities	1,561		—				—				1,561
	Credit card asset-backed securities of other issuers	—		6				—				6
	Residential mortgage-backed securities - Agency	—		1,307				—				1,307
	Available-for-sale investment securities	$	3,618	$	1,313			$	—			$	4,931
	Mortgage loans held for sale	$	—	$	148			$	—			$	148
	Interest rate lock commitments	$	—	$	—			$	4			$	4
	Forward delivery contracts	—		5				—				5
	Other derivative financial instruments	—		70				—				70
	Derivative financial instruments	$	—	$	75			$	4			$	79
	Liabilities
	Forward delivery contracts	$	—	$	1			$	—			$	1
	Other derivative financial instruments	—		6				—				6
	Derivative financial instruments	$	—	$	7			$	—			$	7
Schedule of Changes in Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis	'
	The following tables provide changes in the Company’s Level 3 assets and liabilities measured at fair value on a recurring basis (dollars in millions):
	For the Three Months Ended March 31, 2014
		Balance at December 31, 2013		Transfers into			Transfers out of Level 3			Total Net Gains included in Earnings			Purchases			Sales		Settlements	Transfers of IRLCs to Closed Loans		Balance at March 31, 2014
				Level 3
	Interest rate lock commitments	$	4	—			—			18			—			—		—	(17	)	$	5
	Forward delivery contracts	$	—	—			(1	)		1			—			—		—	—		$	—
	Mortgage loans held for sale	$	—	1			—			—			—			(1	)	—	—		$	—
	For the Three Months Ended March 31, 2013
		Balance at December 31, 2012		Transfers into			Transfers out of Level 3			Total Net Gains included in Earnings			Purchases			Sales		Settlements	Transfers of IRLCs to Closed Loans		Balance at March 31, 2013
				Level 3
	Interest rate lock commitments	$	12	—			—			48			—			—		3	(49	)	$	14
	Mortgage loans held for sale	$	—	1			—			—			—			—		—	—		$	1
Schedule of Significant Unobservable Inputs Related to Level 3 Assets and Liabilities	'
	The following table presents information about significant unobservable inputs related to the Company's Level 3 financial assets and liabilities measured at fair value on a recurring and non-recurring basis at the end of the current period (dollars in millions):
		Fair Value		Valuation		Significant		Ranges of Inputs						Weighted Average(1)
				Technique		Unobservable
	March 31, 2014					Input		Low			High
	Interest rate lock commitments	$	5	Quantitative risk models		Loan funding probability		8	%		100	%		59	%
	-1	Weighted averages are calculated using notional amounts for derivative instruments.
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):
		Quoted Prices in Active Markets		Significant				Significant				Total				Carrying
		for Identical		Other				Unobservable								Value
		Assets (Level 1)		Observable				Inputs (Level 3)
				Inputs (Level 2)
	Balance at March 31, 2014
	Assets
	U.S Treasury securities	$	1	$	—			$	—			$	1			$	1
	States and political subdivisions of states	—		10				—				10				10
	Residential mortgage-backed securities - Agency	—		51				—				51				51
	Held-to-maturity investment securities	$	1	$	61			$	—			$	62			$	62
	Cash and cash equivalents	$	8,731	$	—			$	—			$	8,731			$	8,731
	Restricted cash	$	1,163	$	—			$	—			$	1,163			$	1,163
	Net loan receivables(1)	$	—	$	—			$	49,785			$	49,785			$	62,128
	Accrued interest receivables	$	—	$	560			$	—			$	560			$	560
	Liabilities
	Deposits	$	—	$	45,232			$	—			$	45,232			$	44,984
	Short-term borrowings	$	—	$	124			$	—			$	124			$	124
	Long-term borrowings - owed to securitization investors	$	—	$	14,731			$	1,853			$	16,584			$	16,295
	Other long-term borrowings	$	—	$	4,410			$	1			$	4,411			$	3,887
	Accrued interest payables	$	—	$	129			$	—			$	129			$	129
	Balance at December 31, 2013
	Assets
	U.S Treasury securities	$	1	$	—			$	—			$	1			$	1
	States and political subdivisions of states	—		14				—				14				15
	Residential mortgage-backed securities - Agency	—		43				—				43				44
	Held-to-maturity investment securities	$	1	$	57			$	—			$	58			$	60
	Cash and cash equivalents	$	6,554	$	—			$	—			$	6,554			$	6,554
	Restricted cash	$	182	$	—			$	—			$	182			$	182
	Net loan receivables(1)	$	—	$	—			$	64,968			$	64,968			$	63,975
	Accrued interest receivables	$	—	$	556			$	—			$	556			$	556
	Liabilities
	Deposits	$	—	$	45,231			$	—			$	45,231			$	44,959
	Short-term borrowings	$	—	$	140			$	—			$	140			$	140
	Long-term borrowings - owed to securitization investors	$	—	$	15,312			$	1,971			$	17,283			$	16,986
	Other long-term borrowings	$	—	$	3,934			$	1			$	3,935			$	3,488
	Accrued interest payables	$	—	$	117			$	—			$	117			$	117
	-1	Net loan receivables exclude mortgage loans held for sale that are measured at fair value on a recurring basis.

Derivatives_and_Hedging_Activi1

Derivatives and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of Fair Value and Related Outstanding Notional Amounts of Derivative Instruments	'
	The following table summarizes the fair value (including accrued interest) and related outstanding notional amounts of derivative instruments and indicates where within the statement of financial condition each is reported (dollars in millions):
		March 31, 2014												December 31, 2013
								Statement of Financial Position Location								Statement of Financial Position Location
		Notional				Number of		Other			Accrued Expenses  and Other Liabilities (At Fair Value)			Notional		Other			Accrued
		Amount				Transactions		Assets						Amount		Assets			Expenses  and
								(At Fair								(At Fair			Other
								Value)								Value)			Liabilities
																			(At Fair
																			Value)
	Derivatives designated as hedges:
	Interest rate swaps—cash flow hedge	$	2,950			6		$	13		$	1		$	2,650	$	18		$	—
	Interest rate swaps—fair value hedge	$	6,686			218		54			6			$	7,138	52			6
	Foreign exchange forward contract - net investment hedge(1)	$	33			1		—			—			$	35	—			—
	Derivatives not designated as hedges:
	Foreign exchange forward contracts(2)	$	43			9		—			—			$	44	—			—
	Interest rate swap(3)	$	446			1		—			—			$	796	—			—
	Forward delivery contracts	$	560			453		1			1			$	693	5			1
	Interest rate lock commitments(3)	$	302			1,365		5			—			$	235	4			—
	Total gross derivative assets / liabilities(4)							73			8					79			7
	Less: Collateral receivable / payable(5)							(57		)	(8		)			(61		)	(7		)
	Total net derivative assets / liabilities							$	16		$	—				$	18		$	—
	-1	The foreign exchange forward contract has a notional amount of EUR 24 million and EUR 26 million as of March 31, 2014 and December 31, 2013, respectively.
	-2	The foreign exchange forward contracts have notional amounts of EUR 21 million, GBP 4 million, SGD 2 million, and CHF 6 million as of March 31, 2014, and EUR 20 million, GBP 6 million, SGD 1 million, CHF 5 million as of December 31, 2013.
	-3	Interest rate swaps not designated as hedges and interest rate lock commitments do not have associated master netting arrangements.
	-4	In addition to the derivatives disclosed in the table, the Company had one outstanding forward contract to purchase when-issued mortgage-backed securities as part of our community reinvestment initiatives. This forward contract had a notional amount of $32 million and $40 million and immaterial fair values as of March 31, 2014 and December 31, 2013, respectively.
	-5	Collateral amounts, which consist of both cash and investment securities, are limited to the related derivative asset/liability balance and do not include excess collateral received/pledged.
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 consolidated statements of income such impact is reported for the period (dollars in millions):
				For the Three Months Ended March 31,
		Location		2014			2013
	Derivatives designated as hedges:
	Interest rate swaps—cash flow hedges:
	Total losses recognized in other comprehensive income after amounts reclassified into earnings, pre-tax	Other Comprehensive		$	(6	)	$	(2	)
		Income
	Total losses recognized in other comprehensive income			$	(6	)	$	(2	)
	Amount reclassified from other comprehensive income into income	Interest Income		$	—		$	2
	Amount reclassified from other comprehensive income into income	Interest Expense		(7		)	—
	Interest rate swaps—fair value hedges:
	Interest expense—ineffectiveness			(2		)	(8		)
	Interest expense—other			10			10
	Gain (loss) on interest rate swaps	Interest Expense		8			2
	Interest expense—ineffectiveness			3			9
	Interest expense—other			3			(1		)
	Gain on hedged item	Interest Expense		6			8
	Total gains recognized in income			$	7		$	12
	Derivatives not designated as hedges:
	Gain on forward contracts	Other Income		$	—		$	2
	Loss on interest rate swaps	Other Income		(1		)	—
	Loss on forward delivery contracts	Other Income		(3		)	(1		)
	Gain on interest rate lock commitments	Other Income		18			48
	Total gains on derivatives not designated as hedges recognized in income			$	14		$	49

Segment_Disclosures_Tables

Segment Disclosures (Tables)	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Schedule of Segment Disclosures	'
	The following table presents segment data for the period (dollars in millions):
		Direct		Payment		Total
		Banking		Services
	For the Three Months Ended March 31, 2014
	Interest income
	Credit card	$	1,537	$	—	$	1,537
	Private student loans	73		—		73
	PCI student loans	68		—		68
	Personal loans	132		—		132
	Other	23		—		23
	Total interest income	1,833		—		1,833
	Interest expense	270		—		270
	Net interest income	1,563		—		1,563
	Provision for loan losses	270		2		272
	Other income	436		79		515
	Other expense	735		49		784
	Income before income tax expense	$	994	$	28	$	1,022
	For the Three Months Ended March 31, 2013
	Interest income
	Credit card	$	1,451	$	—	$	1,451
	Private student loans	58		—		58
	PCI student loans	70		—		70
	Personal loans	103		—		103
	Other	26		—		26
	Total interest income	1,708		—		1,708
	Interest expense	298		—		298
	Net interest income	1,410		—		1,410
	Provision for loan losses	159		—		159
	Other income	495		87		582
	Other expense	713		40		753
	Income before income tax expense	$	1,033	$	47	$	1,080

Investments_Narrative_Details

Investments (Narrative) (Details) (USD $)

3 Months Ended

3 Months Ended

In Millions, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Community Reinvestment Act [Member]

Community Reinvestment Act [Member]

Community Reinvestment Act [Member]

Community Reinvestment Act [Member]

Residential Mortgage Backed Securities [Member]

Residential Mortgage Backed Securities [Member]

Asset-backed Securities, Securitized Loans and Receivables [Member]

US Government Agencies Debt Securities [Member]

US Treasury Securities [Member]

US Treasury and Government [Member]

US Treasury and Government [Member]

Other Assets [Member]

Other Assets [Member]

Other Liabilities [Member]

Other Liabilities [Member]

Maturities of Available for Sale Securities [Member]

Maturities of Available for Sale Securities [Member]

Maturities of Available for Sale Securities [Member]

Maturities of Available for Sale Securities [Member]

Maturities of Available for Sale Securities [Member]

Investment Holdings [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds related to maturities, or redemptions of investment securities

$60

$309

'

'

'

'

$49

$82

$6

$100

$75

'

'

Proceeds from sale of available-for-sale securities

'

'

'

'

'

'

'

'

'

'

'

1,200

719

Realized gain (loss) on sales of available-for-sale securities

4

2

'

'

'

'

'

'

'

'

'

'

'

Other than temporary impairment loss on investments

0

0

'

'

'

'

'

'

'

'

'

'

'

Other comprehensive income (loss), unrealized holding gain (loss) on securities arising during period, before tax

3

-16

'

'

'

'

'

'

'

'

'

'

'

Other comprehensive income (loss), unrealized holding gain (loss) on securities arising during period, net of tax

2

-11

'

'

'

'

'

'

'

'

'

'

'

Equity method investments

'

'

300

308

'

'

'

'

'

'

'

'

'

Contingent liabilities related to equity method investments

'

'

'

'

$28

$52

'

'

'

'

'

'

'

Investments_Schedule_of_Invest

Investments (Schedule of Investment Securities) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Investment Holdings [Line Items]	'		'
Total investment securities	$3,964		$4,991
US Treasury Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Total investment securities	1,343	[1]	2,058	[1]
Derivative collateral	7		9
US Government Corporations and Agencies Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Total investment securities	1,047		1,561
US States and Political Subdivisions Debt Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Total investment securities	10		15
Total Other Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Total investment securities	1,564		1,357
Credit Card Asset-Backed Securities of Other Issuers [Member]	'		'
Investment Holdings [Line Items]	'		'
Total investment securities	0		6
Residential Mortgage Backed Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Total investment securities	$1,564	[2]	$1,351	[2]
[1]	Includes $7 million and $9 million of U.S. Treasury securities that have been pledged as swap collateral in lieu of cash as of March 31, 2014 and December 31, 2013, respectively.
[2]	Consists of residential mortgage-backed securities issued by Fannie Mae, Freddie Mac and Ginnie Mae.

Investments_Schedule_of_Amorti

Investments (Schedule of Amortized Cost, Gross Unrealized Gains and Gross Unrealized Losses and Fair Value) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Investment Holdings [Line Items]	'		'
Available-for-sale investment securities, amortized cost	$3,868	[1]	$4,900	[1]
Available-for-sale investment securities, gross unrealized gains	47	[1]	53	[1]
Available-for-sale investment securities, gross unrealized losses	-13	[1]	-22	[1]
Available-for-sale investment securities, fair value	3,902	[1]	4,931	[1]
Held-to-maturity investment securities, amortized cost	62	[2]	60	[2]
Held-to-maturity investment securities, gross unrealized gains	0	[2]	0	[2]
Held-to-maturity investment securities, gross unrealized losses	0	[2]	-2	[2]
Held-to-maturity investment securities, fair value	62	[2]	58	[2]
US Treasury Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale investment securities, amortized cost	1,320	[1]	2,030	[1]
Available-for-sale investment securities, gross unrealized gains	22	[1]	27	[1]
Available-for-sale investment securities, gross unrealized losses	0	[1]	0	[1]
Available-for-sale investment securities, fair value	1,342	[1]	2,057	[1]
Held-to-maturity investment securities, amortized cost	1	[2],[3]	1	[2],[3]
Held-to-maturity investment securities, gross unrealized gains	0	[2],[3]	0	[2],[3]
Held-to-maturity investment securities, gross unrealized losses	0	[2],[3]	0	[2],[3]
Held-to-maturity investment securities, fair value	1	[2],[3]	1	[2],[3]
US Government Corporations and Agencies Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale investment securities, amortized cost	1,025	[1]	1,535	[1]
Available-for-sale investment securities, gross unrealized gains	22	[1]	26	[1]
Available-for-sale investment securities, gross unrealized losses	0	[1]	0	[1]
Available-for-sale investment securities, fair value	1,047	[1]	1,561	[1]
Asset-backed Securities, Securitized Loans and Receivables [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale investment securities, amortized cost	'		6	[1]
Available-for-sale investment securities, gross unrealized gains	'		0	[1]
Available-for-sale investment securities, gross unrealized losses	'		0	[1]
Available-for-sale investment securities, fair value	'		6	[1]
US States and Political Subdivisions Debt Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Held-to-maturity investment securities, amortized cost	10	[2]	15	[2]
Held-to-maturity investment securities, gross unrealized gains	0	[2]	0	[2]
Held-to-maturity investment securities, gross unrealized losses	0	[2]	-1	[2]
Held-to-maturity investment securities, fair value	10	[2]	14	[2]
Residential Mortgage Backed Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale investment securities, amortized cost	1,523	[1]	1,329	[1]
Available-for-sale investment securities, gross unrealized gains	3	[1]	0	[1]
Available-for-sale investment securities, gross unrealized losses	-13	[1]	-22	[1]
Available-for-sale investment securities, fair value	1,513	[1]	1,307	[1]
Held-to-maturity investment securities, amortized cost	51	[2],[4]	44	[2],[4]
Held-to-maturity investment securities, gross unrealized gains	0	[2],[4]	0	[2],[4]
Held-to-maturity investment securities, gross unrealized losses	0	[2],[4]	-1	[2],[4]
Held-to-maturity investment securities, fair value	$51	[2],[4]	$43	[2],[4]
[1]	Available-for-sale investment securities are reported at fair value.
[2]	Held-to-maturity investment securities are reported at amortized cost.
[3]	Amount represents securities pledged as collateral to a government-related merchant for which transaction settlement occurs beyond the normal 24-hour period.
[4]	Amounts represent residential mortgage-backed securities that were classified as held-to-maturity as they were entered into as a part of the Company's community reinvestment initiatives.

Investments_Investments_Schedu

Investments Investments (Schedule of Fair Value of Securities in a Continuous Unrealized Loss Position for Less Than 12 Months and More Than 12 Months) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	securities	securities
Residential Mortgage Backed Securities [Member]	'	'
Investment Holdings [Line Items]	'	'
Available-for-sale investment securities, number of securities in a loss position (in securities)	22	23
Available-for-sale investment securities, continuous unrealized loss position, less than 12 months, fair value	$999	$1,097
Available-for-sale investment securities, continuous unrealized loss position, less than 12 months, unrealized losses	-12	-20
Available-for-sale investment securities, continuous unrealized loss position, more than 12 months, fair value	47	48
Available-for-sale investment securities, continuous unrealized loss position, more than 12 months, unrealized losses	-1	-2
Held-to-maturity investment securities, number of securities in a loss position (in securities)	5	2
Held-to-maturity investment securities, continuous unrealized loss position, less than 12 months, fair value	29	40
Held-to-maturity investment securities, continuous unrealized loss position, less than 12 months, unrealized losses	0	-1
Held-to-maturity investment securities, continuous unrealized loss position, more than 12 months, fair value	0	0
Held-to-maturity investment securities, continuous unrealized loss position, more than 12 months, unrealized losses	0	0
US States and Political Subdivisions Debt Securities [Member]	'	'
Investment Holdings [Line Items]	'	'
Held-to-maturity investment securities, number of securities in a loss position (in securities)	4	4
Held-to-maturity investment securities, continuous unrealized loss position, less than 12 months, fair value	5	8
Held-to-maturity investment securities, continuous unrealized loss position, less than 12 months, unrealized losses	0	-1
Held-to-maturity investment securities, continuous unrealized loss position, more than 12 months, fair value	3	3
Held-to-maturity investment securities, continuous unrealized loss position, more than 12 months, unrealized losses	$0	$0

Investments_Schedule_of_Maturi

Investments (Schedule of Maturities and Weighted Average Yields of Available-for-Sale Debt Securities and Held-to-Maturity Debt Securities) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Investment Holdings [Line Items]	'		'
Available-for-sale investment securities, debt maturities, one year or less, amortized cost	$228	[1]	'
Available-for-sale investment securities, debt maturities, after one year through five years, amortized cost	2,117	[1]	'
Available-for-sale investment securities, debt maturities, after five years through ten years, amortized cost	422	[1]	'
Available-for-sale investment securities, debt maturities, after ten years, amortized cost	1,101	[1]	'
Available-for-sale investment securities, amortized cost	3,868	[1]	'
Held-to-maturity investment securities, debt maturities, one year or less, amortized cost	1	[2]	'
Held-to-maturity investment securities, debt maturities, after one year through five years, amortized cost	0	[2]	'
Held-to-maturity investment securities, debt maturities, after five years through ten years, amortized cost	0	[2]	'
Held-to-maturity investment securities, debt maturities, after ten years, amortized cost	61	[2]	'
Held-to-maturity investment securities, amortized cost	62	[2]	60	[2]
Available-for-sale investment securities, debt maturities, one year or less, fair value	230	[1]	'
Available-for-sale investment securities, debt maturities, after one year through five years, fair value	2,159	[1]	'
Available-for-sale investment securities, debt maturities, after five years through ten years, fair value	420	[1]	'
Available-for-sale investment securities, debt maturities, after ten years, fair value	1,093	[1]	'
Available-for-sale investment securities, fair value	3,902	[1]	4,931	[1]
Held-to-maturity investment securities, debt maturities, one year or less, fair value	1	[2]	'
Held-to-maturity investment securities, debt maturities, after one year through five years, fair value	0	[2]	'
Held-to-maturity investment securities, debt maturities, after five years through ten years, fair value	0	[2]	'
Held-to-maturity investment securities, debt maturities, after ten years, fair value	61	[2]	'
Held-to-maturity investment securities, fair value	62	[2]	58	[2]
US Treasury Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale investment securities, debt maturities, one year or less, amortized cost	126	[1]	'
Available-for-sale investment securities, debt maturities, after one year through five years, amortized cost	1,194	[1]	'
Available-for-sale investment securities, debt maturities, after five years through ten years, amortized cost	0	[1]	'
Available-for-sale investment securities, debt maturities, after ten years, amortized cost	0	[1]	'
Available-for-sale investment securities, amortized cost	1,320	[1]	'
Held-to-maturity investment securities, debt maturities, one year or less, amortized cost	1	[2]	'
Held-to-maturity investment securities, debt maturities, after one year through five years, amortized cost	0	[2]	'
Held-to-maturity investment securities, debt maturities, after five years through ten years, amortized cost	0	[2]	'
Held-to-maturity investment securities, debt maturities, after ten years, amortized cost	0	[2]	'
Held-to-maturity investment securities, amortized cost	1	[2],[3]	1	[2],[3]
Available-for-sale investment securities, debt maturities, one year or less, fair value	127	[1]	'
Available-for-sale investment securities, debt maturities, after one year through five years, fair value	1,215	[1]	'
Available-for-sale investment securities, debt maturities, after five years through ten years, fair value	0	[1]	'
Available-for-sale investment securities, debt maturities, after ten years, fair value	0	[1]	'
Available-for-sale investment securities, fair value	1,342	[1]	2,057	[1]
Held-to-maturity investment securities, debt maturities, one year or less, fair value	1	[2]	'
Held-to-maturity investment securities, debt maturities, after one year through five years, fair value	0	[2]	'
Held-to-maturity investment securities, debt maturities, after five years through ten years, fair value	0	[2]	'
Held-to-maturity investment securities, debt maturities, after ten years, fair value	0	[2]	'
Held-to-maturity investment securities, fair value	1	[2],[3]	1	[2],[3]
US Government Corporations and Agencies Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale investment securities, debt maturities, one year or less, amortized cost	102	[1]	'
Available-for-sale investment securities, debt maturities, after one year through five years, amortized cost	923	[1]	'
Available-for-sale investment securities, debt maturities, after five years through ten years, amortized cost	0	[1]	'
Available-for-sale investment securities, debt maturities, after ten years, amortized cost	0	[1]	'
Available-for-sale investment securities, amortized cost	1,025	[1]	'
Available-for-sale investment securities, debt maturities, one year or less, fair value	103	[1]	'
Available-for-sale investment securities, debt maturities, after one year through five years, fair value	944	[1]	'
Available-for-sale investment securities, debt maturities, after five years through ten years, fair value	0	[1]	'
Available-for-sale investment securities, debt maturities, after ten years, fair value	0	[1]	'
Available-for-sale investment securities, fair value	1,047	[1]	1,561	[1]
Residential Mortgage Backed Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale investment securities, debt maturities, one year or less, amortized cost	0	[1]	'
Available-for-sale investment securities, debt maturities, after one year through five years, amortized cost	0	[1]	'
Available-for-sale investment securities, debt maturities, after five years through ten years, amortized cost	422	[1]	'
Available-for-sale investment securities, debt maturities, after ten years, amortized cost	1,101	[1]	'
Available-for-sale investment securities, amortized cost	1,523	[1]	'
Held-to-maturity investment securities, debt maturities, one year or less, amortized cost	0	[2]	'
Held-to-maturity investment securities, debt maturities, after one year through five years, amortized cost	0	[2]	'
Held-to-maturity investment securities, debt maturities, after five years through ten years, amortized cost	0	[2]	'
Held-to-maturity investment securities, debt maturities, after ten years, amortized cost	51	[2]	'
Held-to-maturity investment securities, amortized cost	51	[2],[4]	44	[2],[4]
Available-for-sale investment securities, debt maturities, one year or less, fair value	0	[1]	'
Available-for-sale investment securities, debt maturities, after one year through five years, fair value	0	[1]	'
Available-for-sale investment securities, debt maturities, after five years through ten years, fair value	420	[1]	'
Available-for-sale investment securities, debt maturities, after ten years, fair value	1,093	[1]	'
Available-for-sale investment securities, fair value	1,513	[1]	1,307	[1]
Held-to-maturity investment securities, debt maturities, one year or less, fair value	0	[2]	'
Held-to-maturity investment securities, debt maturities, after one year through five years, fair value	0	[2]	'
Held-to-maturity investment securities, debt maturities, after five years through ten years, fair value	0	[2]	'
Held-to-maturity investment securities, debt maturities, after ten years, fair value	51	[2]	'
Held-to-maturity investment securities, fair value	51	[2],[4]	43	[2],[4]
US States and Political Subdivisions Debt Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Held-to-maturity investment securities, debt maturities, one year or less, amortized cost	0	[2]	'
Held-to-maturity investment securities, debt maturities, after one year through five years, amortized cost	0	[2]	'
Held-to-maturity investment securities, debt maturities, after five years through ten years, amortized cost	0	[2]	'
Held-to-maturity investment securities, debt maturities, after ten years, amortized cost	10	[2]	'
Held-to-maturity investment securities, amortized cost	10	[2]	15	[2]
Held-to-maturity investment securities, debt maturities, one year or less, fair value	0	[2]	'
Held-to-maturity investment securities, debt maturities, after one year through five years, fair value	0	[2]	'
Held-to-maturity investment securities, debt maturities, after five years through ten years, fair value	0	[2]	'
Held-to-maturity investment securities, debt maturities, after ten years, fair value	10	[2]	'
Held-to-maturity investment securities, fair value	$10	[2]	$14	[2]
[1]	Available-for-sale investment securities are reported at fair value.
[2]	Held-to-maturity investment securities are reported at amortized cost.
[3]	Amount represents securities pledged as collateral to a government-related merchant for which transaction settlement occurs beyond the normal 24-hour period.
[4]	Amounts represent residential mortgage-backed securities 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_Det

Loan Receivables (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Threshold charge-off period for bankruptcy and probate accounts	'60 days	'	'	'
Open-end charge-off period for bankruptcy and probate accounts	'180 days	'	'	'
Closed-end charge-off period for bankruptcy and probate accounts	'120 days	'	'	'
Private student loan forbearance lifetime cap	'12 months	'	'	'
Private student loans in forbearance	$77,000,000	'	$110,000,000	'
Private student loans in forbearance as a percentage of student loans in repayment and forbearance (percentage)	1.40%	'	1.90%	'
Interest and fees forgiven due to credit card loan modification program	10,000,000	11,000,000	'	'
Percentage of defaulted loans that were charged off at the end of the month in which they defaulted (percentage)	34.00%	45.00%	'	'
Purchased credit-impaired loans outstanding balance	4,400,000,000	'	4,600,000,000	'
Purchased credit-impaired loans	4,046,000,000	'	4,178,000,000	'
Provision for loan losses	272,000,000	159,000,000	'	'
Allowance for loan losses	1,591,000,000	1,634,000,000	1,648,000,000	1,788,000,000
30 days or more delinquency rate for purchased credit-impaired loans (rate)	2.19%	'	2.33%	'
90 days or more delinquency rate for purchased credit-impaired loans (rate)	0.79%	'	0.80%	'
Net charge-off rate for purchased credit-impaired loans (rate)	0.75%	1.43%	'	'
Credit Card Receivable [Member]	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Threshold charge-off period for past due accounts	'180 days	'	'	'
Temporary hardship program maturity	'12 months	'	'	'
Permanent workout program maturity	'60 months	'	'	'
Provision for loan losses	230,000,000	127,000,000	'	'
Allowance for loan losses	1,342,000,000	1,453,000,000	1,406,000,000	1,613,000,000
Personal And Private Student Loan Member [Member]	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Threshold charge-off period for past due accounts	'120 days	'	'	'
Student Loans [Member]	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Maximum forbearance period for student loan borrowers	'12 months	'	'	'
Maximum period of payment reduction for the temporary reduced payment program	'12 months	'	'	'
Period triggering TDR accounting for the temporary reduced payment program	'12 months	'	'	'
Personal Loans [Member]	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Temporary hardship program maturity	'12 months	'	'	'
Maximum period of interest rate reduction for the temporary APR reduction program	'12 months	'	'	'
New repayment term for permanent modification programs	'4 years	'	'	'
Maximum repayment term for permanent modification programs	'9 years	'	'	'
PCI Student Loans [Member]	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Provision for loan losses	0	0	'	'
Allowance for loan losses	$28,000,000	'	$28,000,000	'

Loan_Receivables_Schedule_of_L

Loan Receivables (Schedule of Loan Receivables) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Mortgage loans held for sale	$133,000,000	[1]	$148,000,000	[1]	'	'
Total credit card loans	50,879,000,000		53,150,000,000		'	'
Total other loans	8,794,000,000		8,295,000,000		'	'
Purchased credit-impaired loans	4,046,000,000		4,178,000,000		'	'
Total loan portfolio	63,719,000,000		65,623,000,000		'	'
Total loan receivables	63,852,000,000		65,771,000,000		'	'
Allowance for loan losses	-1,591,000,000		-1,648,000,000		-1,634,000,000	-1,788,000,000
Net loan receivables	62,261,000,000		64,123,000,000		'	'
Variable Interest Entity, Primary Beneficiary [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Allowance for loan losses	-807,000,000		-861,000,000		'	'
Credit Card Securitization Trusts [Member] | Variable Interest Entity, Primary Beneficiary [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Total credit card loans	29,157,000,000	[2]	31,112,000,000	[2]	'	'
Allowance for loan losses	-779,000,000	[2]	-833,000,000	[2]	'	'
Sellers' interest	9,535,000,000		10,898,000,000		'	'
Credit Card Receivable [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Total credit card loans	50,879,000,000		53,150,000,000		'	'
Total loan portfolio	50,879,000,000		53,150,000,000		'	'
Allowance for loan losses	-1,342,000,000		-1,406,000,000		-1,453,000,000	-1,613,000,000
Total Other Loans [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Total other loans	8,794,000,000		8,295,000,000		'	'
PCI Student Loans [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Purchased credit-impaired loans	4,046,000,000	[3]	4,178,000,000	[3]	'	'
Loans pledged as collateral	2,200,000,000		2,200,000,000		'	'
Private Student Loans Not Pledged as Collateral [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Purchased credit-impaired loans	1,800,000,000		2,000,000,000		'	'
Private Student Loans Eligible for Reimbursement [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Purchased credit-impaired loans	22,000,000		22,000,000		'	'
Discover Card [Member] | Credit Card Receivable [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Total credit card loans	50,685,000,000	[4]	52,952,000,000	[4]	'	'
Discover Business Card [Member] | Credit Card Receivable [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Total credit card loans	194,000,000		198,000,000		'	'
Personal Loans [Member] | Total Other Loans [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Total other loans	4,310,000,000		4,191,000,000		'	'
Total loan portfolio	4,310,000,000		4,191,000,000		'	'
Allowance for loan losses	-109,000,000		-112,000,000		-97,000,000	-99,000,000
Private Student Loans (Excluding PCI) [Member] | Total Other Loans [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Total other loans	4,326,000,000		3,969,000,000		'	'
Other Loans [Member] | Total Other Loans [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Total other loans	158,000,000		135,000,000		'	'
Total loan portfolio	158,000,000		135,000,000		'	'
Allowance for loan losses	-18,000,000		-17,000,000		-1,000,000	-1,000,000
Investors Interest in Trust Debt [Member] | Credit Card Receivable [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Total credit card loans	$19,600,000,000		$20,200,000,000		'	'
[1]	Substantially all mortgage loans held for sale are pledged as collateral against the warehouse line of credit used to fund consumer residential loans.
[2]	The Company maintains its allowance for loan losses at an amount sufficient to absorb probable losses inherent in all loan receivables, which includes all loan receivables in the trusts. Therefore, credit risk associated with the transferred receivables is fully reflected on the Company’s balance sheet in accordance with GAAP.
[3]	Amounts include $2.2 billion of loans pledged as collateral against the notes issued from the Student Loan Corporation ("SLC") securitization trusts at March 31, 2014 and December 31, 2013. See Note 4: Credit Card and Student Loan Securitization Activities. Of the remaining $1.8 billion and $2.0 billion at March 31, 2014 and December 31, 2013, respectively, that were not pledged as collateral, approximately $22 million for each period represents loans eligible for reimbursement through an indemnification claim. Discover Bank must purchase such loans from the trust before a claim may be filed.
[4]	Amounts include $19.6 billion and $20.2 billion underlying investors’ interest in trust debt at March 31, 2014 and December 31, 2013, respectively, and $9.5 billion and $10.9 billion in seller's interest at March 31, 2014 and December 31, 2013, respectively. See Note 4: Credit Card and Student Loan Securitization Activities for further information.

Loan_Receivables_Schedule_of_D

Loan Receivables (Schedule of Delinquent and Non-Accruing Loans) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'	'
Loan receivables, 30 to 89 days delinquent	$507		'	$535
Loan receivables, 90 or more days delinquent	478		'	475
Loan receivables, total past due	985		'	1,010
Loan receivables, 90 or more days delinquent and accruing	437		'	434
Loan receivables, total non-accruing	207		'	200
Consumer Credit Card Financing Receivable [Member]	'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'	'
Loan receivables, 90 or more days delinquent and accruing	42		'	41
Personal Loan Financing Receivable [Member]	'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'	'
Loan receivables, 90 or more days delinquent and accruing	2		'	2
Private Student Loan (excluding PCI) Financing Receivable [Member]	'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'	'
Loan receivables, 90 or more days delinquent and accruing	3		'	3
Credit Card Receivable [Member]	'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'	'
Loan receivables, 30 to 89 days delinquent	434		'	465
Loan receivables, 90 or more days delinquent	442		'	447
Loan receivables, total past due	876		'	912
Loan receivables, 90 or more days delinquent and accruing	404		'	408
Loan receivables, total non-accruing	163	[1]	'	155	[1]
Estimated gross interest income that would have been recorded based on original terms	7		8	'
Total Other Loans [Member]	'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'	'
Loan receivables, 30 to 89 days delinquent	73		'	70
Loan receivables, 90 or more days delinquent	36		'	28
Loan receivables, total past due	109		'	98
Loan receivables, 90 or more days delinquent and accruing	33		'	26
Loan receivables, total non-accruing	44		'	45
Discover Card [Member] | Credit Card Receivable [Member]	'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'	'
Loan receivables, 30 to 89 days delinquent	432		'	464
Loan receivables, 90 or more days delinquent	441		'	445
Loan receivables, total past due	873		'	909
Loan receivables, 90 or more days delinquent and accruing	402	[2]	'	406	[2]
Loan receivables, total non-accruing	162		'	154
Discover Business Card [Member] | Credit Card Receivable [Member]	'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'	'
Loan receivables, 30 to 89 days delinquent	2		'	1
Loan receivables, 90 or more days delinquent	1		'	2
Loan receivables, total past due	3		'	3
Loan receivables, 90 or more days delinquent and accruing	2		'	2
Loan receivables, total non-accruing	1		'	1
Personal Loans [Member] | Total Other Loans [Member]	'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'	'
Loan receivables, 30 to 89 days delinquent	21		'	21
Loan receivables, 90 or more days delinquent	8		'	8
Loan receivables, total past due	29		'	29
Loan receivables, 90 or more days delinquent and accruing	7	[3]	'	8	[3]
Loan receivables, total non-accruing	5		'	5
Private Student Loans (Excluding PCI) [Member] | Total Other Loans [Member]	'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'	'
Loan receivables, 30 to 89 days delinquent	51		'	48
Loan receivables, 90 or more days delinquent	26		'	18
Loan receivables, total past due	77		'	66
Loan receivables, 90 or more days delinquent and accruing	26	[4]	'	18	[4]
Loan receivables, total non-accruing	0		'	0
Other Loans [Member] | Total Other Loans [Member]	'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'	'
Loan receivables, 30 to 89 days delinquent	1		'	1
Loan receivables, 90 or more days delinquent	2		'	2
Loan receivables, total past due	3		'	3
Loan receivables, 90 or more days delinquent and accruing	0		'	0
Loan receivables, total non-accruing	$39		'	$40
[1]	The Company estimates that the gross interest income that would have been recorded in accordance with the original terms of non-accruing credit card loans was $7 million and $8 million for the three months ended March 31, 2014 and 2013, respectively. The Company does not separately systematically compute the amount of gross interest income that would have been recorded in accordance with the original terms of loans. This amount was estimated based on customers' quarterly average balances and rates prior to non-accrual status.
[2]	Consumer credit card loans that are 90 or more days delinquent and accruing interest include $42 million and $41 million of loans accounted for as troubled debt restructurings at March 31, 2014 and December 31, 2013, respectively.
[3]	Personal loans that are 90 or more days delinquent and accruing interest include $2 million of loans accounted for as troubled debt restructurings at March 31, 2014 and December 31, 2013.
[4]	Private student loans that are 90 or more days delinquent and accruing interest include $3 million of loans accounted for as troubled debt restructurings at March 31, 2014 and December 31, 2013.

Loan_Receivables_Schedule_of_N

Loan Receivables (Schedule of Net Charge-offs) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Charge Offs [Line Items]	'	'
Net charge-offs	$329	$313
Excluding PCI Loans [Member]	'	'
Charge Offs [Line Items]	'	'
Net charge-offs	329	313
Net charge-off rate	2.22%	2.25%
Including PCI Loans [Member]	'	'
Charge Offs [Line Items]	'	'
Net charge-offs	329	313
Net charge-off rate	2.08%	2.08%
Credit Card Receivable [Member]	'	'
Charge Offs [Line Items]	'	'
Net charge-offs	294	287
Credit Card Receivable [Member] | Excluding PCI Loans [Member]	'	'
Charge Offs [Line Items]	'	'
Net charge-offs	294	287
Net charge-off rate	2.32%	2.36%
Total Other Loans [Member] | Excluding PCI Loans [Member]	'	'
Charge Offs [Line Items]	'	'
Net charge-offs	35	26
Net charge-off rate	1.67%	1.49%
Discover Card [Member] | Credit Card Receivable [Member] | Excluding PCI Loans [Member]	'	'
Charge Offs [Line Items]	'	'
Net charge-offs	293	286
Net charge-off rate	2.32%	2.36%
Discover Business Card [Member] | Credit Card Receivable [Member] | Excluding PCI Loans [Member]	'	'
Charge Offs [Line Items]	'	'
Net charge-offs	1	1
Net charge-off rate	1.76%	2.66%
Personal Loans [Member] | Total Other Loans [Member]	'	'
Charge Offs [Line Items]	'	'
Net charge-offs	21	19
Personal Loans [Member] | Total Other Loans [Member] | Excluding PCI Loans [Member]	'	'
Charge Offs [Line Items]	'	'
Net charge-offs	21	19
Net charge-off rate	2.07%	2.30%
Private Student Loans (Excluding PCI) [Member] | Total Other Loans [Member] | Excluding PCI Loans [Member]	'	'
Charge Offs [Line Items]	'	'
Net charge-offs	$14	$7
Net charge-off rate	1.31%	0.82%

Loan_Receivables_Schedule_of_C

Loan Receivables (Schedule of Credit Risk Profile by FICO Score) (Details)	Mar. 31, 2014		Dec. 31, 2013
Discover Card [Member] | Credit Card Receivable [Member]	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Credit risk profile by FICO score, 660 and above	82.00%		83.00%
Credit risk profile by FICO score, less than 660 or no score	18.00%		17.00%
Discover Business Card [Member] | Credit Card Receivable [Member]	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Credit risk profile by FICO score, 660 and above	92.00%		92.00%
Credit risk profile by FICO score, less than 660 or no score	8.00%		8.00%
Personal Loans [Member] | Total Other Loans [Member]	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Credit risk profile by FICO score, 660 and above	97.00%		97.00%
Credit risk profile by FICO score, less than 660 or no score	3.00%		3.00%
Private Student Loans (Excluding PCI) [Member] | Total Other Loans [Member]	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Credit risk profile by FICO score, 660 and above	95.00%	[1]	95.00%	[1]
Credit risk profile by FICO score, less than 660 or no score	5.00%	[1]	5.00%	[1]
[1]	PCI loans are discussed under the heading "— Purchased Credit-Impaired Loans."

Loan_Receivables_Schedule_of_C1

Loan Receivables (Schedule of Changes in the Allowance for Loan Losses) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Allowance For Loan And Lease Losses Writeoffs Net Abstract [Roll Forward]	'	'
Balance at beginning of period	$1,648	$1,788
Provision for loan losses	272	159
Charge-offs	-447	-449
Recoveries	118	136
Net charge-offs	-329	-313
Balance at end of period	1,591	1,634
Credit Card Receivable [Member]	'	'
Allowance For Loan And Lease Losses Writeoffs Net Abstract [Roll Forward]	'	'
Balance at beginning of period	1,406	1,613
Provision for loan losses	230	127
Charge-offs	-408	-422
Recoveries	114	135
Net charge-offs	-294	-287
Balance at end of period	1,342	1,453
Total Other Loans [Member] | Personal Loans [Member]	'	'
Allowance For Loan And Lease Losses Writeoffs Net Abstract [Roll Forward]	'	'
Balance at beginning of period	112	99
Provision for loan losses	18	17
Charge-offs	-24	-20
Recoveries	3	1
Net charge-offs	-21	-19
Balance at end of period	109	97
Total Other Loans [Member] | Student Loans [Member]	'	'
Allowance For Loan And Lease Losses Writeoffs Net Abstract [Roll Forward]	'	'
Balance at beginning of period	113	75
Provision for loan losses	23	15
Charge-offs	-15	-7
Recoveries	1	0
Net charge-offs	-14	-7
Balance at end of period	122	83
Total Other Loans [Member] | Other Loans [Member]	'	'
Allowance For Loan And Lease Losses Writeoffs Net Abstract [Roll Forward]	'	'
Balance at beginning of period	17	1
Provision for loan losses	1	0
Charge-offs	0	0
Recoveries	0	0
Net charge-offs	0	0
Balance at end of period	$18	$1

Loan_Receivables_Schedule_of_N1

Loan Receivables (Schedule of Net Charge-offs of Interest and Fee Revenues on Loan Receivables) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Loans and Leases Receivable Disclosure [Abstract]	'	'
Interest and fees accrued subsequently charged off, net of recoveries (recorded as a reduction of interest income)	$72	$77
Fees accrued subsequently charged off, net of recoveries (recorded as a reduction to other income)	$17	$16

Loan_Receivables_Schedule_of_A

Loan Receivables (Schedule of Allowance for Loan Losses and Recorded Investment in its Loan Portfolio by Impairment Methodology) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Allowance for loan losses, collectively evaluated for impairment in accordance with ASC 450-20	$1,353		$1,404		'	'
Allowance for loan losses, evaluated for impairment in accordance with ASC 310-10-35	210	[1],[2]	216	[1],[2]	'	'
Allowance for loan losses, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	28		28		'	'
Total allowance for loan losses	1,591		1,648		1,634	1,788
Recorded investment in loans, collectively evaluated for impairment in accordance with ASC 450-20	58,432		60,184		'	'
Recorded investment in loans, evaluated for impairment in accordance with ASC 310-10-35	1,241	[1],[2]	1,261	[1],[2]	'	'
Recorded investment in loans, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	4,046		4,178		'	'
Total loan portfolio	63,719		65,623		'	'
Credit Card Receivable [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Allowance for loan losses, collectively evaluated for impairment in accordance with ASC 450-20	1,164		1,218		'	'
Allowance for loan losses, evaluated for impairment in accordance with ASC 310-10-35	178	[1],[2]	188	[1],[2]	'	'
Allowance for loan losses, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	0		0		'	'
Total allowance for loan losses	1,342		1,406		1,453	1,613
Recorded investment in loans, collectively evaluated for impairment in accordance with ASC 450-20	49,791		52,027		'	'
Recorded investment in loans, evaluated for impairment in accordance with ASC 310-10-35	1,088	[1],[2]	1,123	[1],[2]	'	'
Recorded investment in loans, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	0		0		'	'
Total loan portfolio	50,879		53,150		'	'
Credit Card Receivable [Member] | Troubled Debt Restructurings [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Unpaid principal balance of modified loans accounted for as troubled debt restructurings	919		900		'	'
Total Other Loans [Member] | Personal Loans [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Allowance for loan losses, collectively evaluated for impairment in accordance with ASC 450-20	104		109		'	'
Allowance for loan losses, evaluated for impairment in accordance with ASC 310-10-35	5	[1],[2]	3	[1],[2]	'	'
Allowance for loan losses, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	0		0		'	'
Total allowance for loan losses	109		112		97	99
Recorded investment in loans, collectively evaluated for impairment in accordance with ASC 450-20	4,265		4,160		'	'
Recorded investment in loans, evaluated for impairment in accordance with ASC 310-10-35	45	[1],[2]	31	[1],[2]	'	'
Recorded investment in loans, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	0		0		'	'
Total loan portfolio	4,310		4,191		'	'
Total Other Loans [Member] | Personal Loans [Member] | Troubled Debt Restructurings [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Unpaid principal balance of modified loans accounted for as troubled debt restructurings	44		31		'	'
Total Other Loans [Member] | Private Student Loans (Excluding PCI) [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Allowance for loan losses, collectively evaluated for impairment in accordance with ASC 450-20	84		76		'	'
Allowance for loan losses, evaluated for impairment in accordance with ASC 310-10-35	10	[1],[2]	9	[1],[2]	'	'
Recorded investment in loans, collectively evaluated for impairment in accordance with ASC 450-20	4,296		3,941		'	'
Recorded investment in loans, evaluated for impairment in accordance with ASC 310-10-35	30	[1],[2]	28	[1],[2]	'	'
Total Other Loans [Member] | Private Student Loans (Excluding PCI) [Member] | Troubled Debt Restructurings [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Unpaid principal balance of modified loans accounted for as troubled debt restructurings	28		26		'	'
Total Other Loans [Member] | Other Loans [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Allowance for loan losses, collectively evaluated for impairment in accordance with ASC 450-20	1		1		'	'
Allowance for loan losses, evaluated for impairment in accordance with ASC 310-10-35	17	[1],[2]	16	[1],[2]	'	'
Allowance for loan losses, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	0		0		'	'
Total allowance for loan losses	18		17		1	1
Recorded investment in loans, collectively evaluated for impairment in accordance with ASC 450-20	80		56		'	'
Recorded investment in loans, evaluated for impairment in accordance with ASC 310-10-35	78	[1],[2]	79	[1],[2]	'	'
Recorded investment in loans, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	0		0		'	'
Total loan portfolio	158		135		'	'
PCI Student Loans [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Allowance for loan losses, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	28		28		'	'
Recorded investment in loans, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	4,046		4,178		'	'
Student Loans [Member]	'		'		'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'
Total allowance for loan losses	122		113		'	'
Total loan portfolio	$8,372		$8,147		'	'
[1]	Loan receivables evaluated for impairment in accordance with ASC 310-10-35 include credit card loans, personal loans and student loans collectively evaluated for impairment in accordance with ASC Subtopic 310-40, Receivables, which consists of modified loans accounted for as troubled debt restructurings. Other loans are individually evaluated for impairment and generally do not represent troubled debt restructurings.
[2]	The unpaid principal balance of credit card loans was $919 million and $900 million at March 31, 2014 and December 31, 2013, respectively. The unpaid principal balance of personal loans was $44 million and $31 million at March 31, 2014 and December 31, 2013, respectively. The unpaid principal balance of student loans was $28 million and $26 million at March 31, 2014 and December 31, 2013, respectively. All loans accounted for as troubled debt restructurings have a related allowance for loan losses.

Loan_Receivables_Schedule_of_T

Loan Receivables (Schedule of Troubled Debt Restructurings) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Credit Card Receivable [Member] | Modified Loans [Member]	'		'
Financing Receivable, Modifications [Line Items]	'		'
Average recorded investment in loans	$256	[1]	$279	[1]
Interest income recognized during period loans were impaired	11	[1],[2]	13	[1],[2]
Gross interest income that would have been recorded with original terms	1	[1],[3]	1	[1],[3]
Credit Card Receivable [Member] | InternalPrograms [Member]	'		'
Financing Receivable, Modifications [Line Items]	'		'
Average recorded investment in loans	454		490
Interest income recognized during period loans were impaired	3	[2]	3	[2]
Gross interest income that would have been recorded with original terms	15	[3]	17	[3]
Credit Card Receivable [Member] | External Programs [Member]	'		'
Financing Receivable, Modifications [Line Items]	'		'
Average recorded investment in loans	394		507
Interest income recognized during period loans were impaired	7	[2]	10	[2]
Gross interest income that would have been recorded with original terms	3	[3]	3	[3]
Total Other Loans [Member] | Personal Loans [Member]	'		'
Financing Receivable, Modifications [Line Items]	'		'
Average recorded investment in loans	44		22
Interest income recognized during period loans were impaired	1	[2]	1	[2]
Gross interest income that would have been recorded with original terms	0	[3]	0	[3]
Total Other Loans [Member] | Student Loans [Member]	'		'
Financing Receivable, Modifications [Line Items]	'		'
Average recorded investment in loans	29	[4]	18	[4]
Interest income recognized during period loans were impaired	$1	[2],[4]	$0	[2],[4]
[1]	This balance is considered impaired, but is excluded from the internal and external program amounts reflected in this table. Represents credit card loans that were modified in troubled debt restructurings, but are no longer enrolled in troubled debt restructuring program due to noncompliance with the terms of the modification or successful completion of a program
[2]	The Company does not separately track interest income on loans in modification programs. Amounts shown are estimated by applying an average interest rate to the average loans in the various modification programs.
[3]	The Company does not separately track the amount of gross interest income that would have been recorded if the loans in modification programs had not been restructured and interest had instead been recorded in accordance with the original terms. Amounts shown are estimated by applying the difference between the average interest rate earned on non-impaired credit card loans and the average interest rate earned on loans in the modification programs to the average loans in the modification programs.
[4]	Student loan customers who have been granted a forbearance are not given interest rate reductions.

Loan_Receivables_Loan_Receivab

Loan Receivables Loan Receivables (Schedule of Loans That Entered a Modification Program During the Period) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
	accounts	accounts
Credit Card Receivable [Member] | InternalPrograms [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Accounts that entered a loan modification program during the period, number of accounts	12,436	10,402
Accounts that entered a loan modification program during the period, balances	$81	$66
Credit Card Receivable [Member] | External Programs [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Accounts that entered a loan modification program during the period, number of accounts	8,431	9,531
Accounts that entered a loan modification program during the period, balances	44	52
Total Other Loans [Member] | Personal Loans [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Accounts that entered a loan modification program during the period, number of accounts	712	443
Accounts that entered a loan modification program during the period, balances	8	6
Total Other Loans [Member] | Student Loans [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Accounts that entered a loan modification program during the period, number of accounts	307	172
Accounts that entered a loan modification program during the period, balances	$4	$4

Loan_Receivables_Loan_Receivab1

Loan Receivables Loan Receivables (Schedule of Troubled Debt Restructurings That Subsequently Defaulted) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
	accounts		accounts
Student Loans [Member]	'		'
Financing Receivable, Modifications [Line Items]	'		'
Delinquency days to default	'60 days		'
Credit Card Receivable [Member] | InternalPrograms [Member]	'		'
Financing Receivable, Modifications [Line Items]	'		'
Troubled debt restructurings that subsequently defaulted, number of accounts	2,331	[1],[2]	2,880	[1],[2]
Troubled debt restructurings that subsequently defaulted, aggregated outstanding balances upon default	$14	[1],[2]	$18	[1],[2]
Credit Card Receivable [Member] | External Programs [Member]	'		'
Financing Receivable, Modifications [Line Items]	'		'
Troubled debt restructurings that subsequently defaulted, number of accounts	1,881	[1],[2]	2,251	[1],[2]
Troubled debt restructurings that subsequently defaulted, aggregated outstanding balances upon default	8	[1],[2]	10	[1],[2]
Total Other Loans [Member] | Personal Loans [Member]	'		'
Financing Receivable, Modifications [Line Items]	'		'
Troubled debt restructurings that subsequently defaulted, number of accounts	106	[1]	24	[1]
Troubled debt restructurings that subsequently defaulted, aggregated outstanding balances upon default	1	[1]	0	[1]
Total Other Loans [Member] | Student Loans [Member]	'		'
Financing Receivable, Modifications [Line Items]	'		'
Troubled debt restructurings that subsequently defaulted, number of accounts	311	[3]	135	[3]
Troubled debt restructurings that subsequently defaulted, aggregated outstanding balances upon default	$5	[3]	$3	[3]
[1]	A customer defaults from a modification program after two consecutive missed payments.
[2]	The outstanding balance upon default is the loan balance at the end of the month prior to default. Terms revert back to the pre-modification terms for customers who default from a temporary program and charging privileges remain revoked.
[3]	Student loan defaults have been defined as loans that are 60 or more days delinquent.

Loan_Receivables_Schedule_of_C2

Loan Receivables (Schedule of Changes in Accretable Yield for the Acquired Loans) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]	'	'
Accretable yield, balance at beginning of period	$1,580	$2,072
Accretion into interest income	-68	-70
Other changes in expected cash flows	0	19
Accretable yield, balance at end of period	$1,512	$2,021

Loan_Receivables_Loan_Receivab2

Loan Receivables Loan Receivables (Schedule of Initial Unpaid Principal Balance of Mortgage Loans Sold by Type) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Mortgage Loans on Real Estate [Line Items]	'		'
Initial unpaid principal balance of mortgage loans, amount	$497		$1,198
Initial unpaid principal balance of mortgage loans, percentage	100.00%		100.00%
Conforming Loans [Member]	'		'
Mortgage Loans on Real Estate [Line Items]	'		'
Initial unpaid principal balance of mortgage loans, amount	447	[1]	665	[1]
Initial unpaid principal balance of mortgage loans, percentage	89.94%	[1]	55.51%	[1]
Federal Housing Administration Loan [Member]	'		'
Mortgage Loans on Real Estate [Line Items]	'		'
Initial unpaid principal balance of mortgage loans, amount	48	[2]	533	[2]
Initial unpaid principal balance of mortgage loans, percentage	9.66%	[2]	44.49%	[2]
Jumbo Mortgage Loan [Member]	'		'
Mortgage Loans on Real Estate [Line Items]	'		'
Initial unpaid principal balance of mortgage loans, amount	$2	[3]	$0	[3]
Initial unpaid principal balance of mortgage loans, percentage	0.40%	[3]	0.00%	[3]
[1]	Conforming loans are loans that conform to Government Sponsored Enterprises guidelines.
[2]	FHA loans are loans that are insured by the Federal Housing Administration and are typically made to borrowers with low down payments. The initial loan amount must be within certain limits.
[3]	Jumbo loans are loans with an initial amount larger than the limits set by a Government Sponsored Enterprise.

Loan_Receivables_Loan_Receivab3

Loan Receivables Loan Receivables (Schedule of Mortgage Loans Held for Sale) (Details) (USD $)	3 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Mortgage Loans on Real Estate [Line Items]	'		'
Mortgage loans held for sale, amount	$133	[1]	$148	[1]
Mortgage loans held for sale, percentage	100.00%		100.00%
Conforming Loans [Member]	'		'
Mortgage Loans on Real Estate [Line Items]	'		'
Mortgage loans held for sale, amount	116	[2]	136	[2]
Mortgage loans held for sale, percentage	87.22%	[2]	91.89%	[2]
FHA Loans [Member]	'		'
Mortgage Loans on Real Estate [Line Items]	'		'
Mortgage loans held for sale, amount	13	[3]	11	[3]
Mortgage loans held for sale, percentage	9.77%	[3]	7.43%	[3]
Jumbo Mortgage Loan [Member]	'		'
Mortgage Loans on Real Estate [Line Items]	'		'
Mortgage loans held for sale, amount	$4	[4]	$1	[4]
Mortgage loans held for sale, percentage	3.01%	[4]	0.68%	[4]
[1]	Substantially all mortgage loans held for sale are pledged as collateral against the warehouse line of credit used to fund consumer residential loans.
[2]	Conforming loans are loans that conform to Government Sponsored Enterprises guidelines.
[3]	FHA loans are loans that are insured by the Federal Housing Administration and are typically made to borrowers with low down payments. The initial loan amount must be within certain limits.
[4]	Jumbo loans are loans with an initial loan amount larger than the limits set by a Government Sponsored Enterprise.

Credit_Card_and_Student_Loan_S2

Credit Card and Student Loan Securitization Activities (Narrative) (Details)	3 Months Ended
	Mar. 31, 2014
Variable Interest Entity [Line Items]	'
Excess spread rate minimum	0.00%
Excess of the total investors' interests	7.00%
Average excess spread rate calculation period	'3 months
Excess spread rate for funding requirement trigger	4.50%
Excess spread rate for increasing funding requirements	0.00%
Student Loan Securitization Trusts [Member]	'
Variable Interest Entity [Line Items]	'
Number of trusts issuing securities	3
Discover Card Execution Note Trust [Member] | Credit Card Securitization Trusts [Member]	'
Variable Interest Entity [Line Items]	'
Number of classes of securities, debt structure	4

Credit_Card_and_Student_Loan_S3

Credit Card and Student Loan Securitization Activities (Schedule of Restricted Credit Card Securitized Assets) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Variable Interest Entity [Line Items]	'		'		'	'
Restricted cash	$1,163		$182		'	'
Loan receivables	50,879		53,150		'	'
Allowance for loan losses allocated to securitized loan receivables	-1,591		-1,648		-1,634	-1,788
Other	2,331		2,367		'	'
Variable Interest Entity, Primary Beneficiary [Member]	'		'		'	'
Variable Interest Entity [Line Items]	'		'		'	'
Restricted cash	1,160		179		'	'
Allowance for loan losses allocated to securitized loan receivables	-807		-861		'	'
Other	37		34		'	'
Variable Interest Entity, Primary Beneficiary [Member] | Credit Card Securitization Trusts [Member]	'		'		'	'
Variable Interest Entity [Line Items]	'		'		'	'
Restricted cash	1,069		90		'	'
Investors’ interests held by third-party investors	14,589		15,190		'	'
Investors’ interests held by wholly-owned subsidiaries of Discover Bank	5,033		5,024		'	'
Seller’s interest	9,535		10,898		'	'
Loan receivables	29,157	[1]	31,112	[1]	'	'
Allowance for loan losses allocated to securitized loan receivables	-779	[1]	-833	[1]	'	'
Net loan receivables	28,378		30,279		'	'
Other	37		34		'	'
Carrying value of assets of consolidated variable interest entities	29,484		30,403		'	'
Variable Interest Entity, Primary Beneficiary [Member] | Credit Card Securitization Trusts [Member] | Cash Collateral Accounts [Member]	'		'		'	'
Variable Interest Entity [Line Items]	'		'		'	'
Restricted cash	8		59		'	'
Variable Interest Entity, Primary Beneficiary [Member] | Credit Card Securitization Trusts [Member] | Collections and Interest Funding Accounts [Member]	'		'		'	'
Variable Interest Entity [Line Items]	'		'		'	'
Restricted cash	$1,061		$31		'	'
[1]	The Company maintains its allowance for loan losses at an amount sufficient to absorb probable losses inherent in all loan receivables, which includes all loan receivables in the trusts. Therefore, credit risk associated with the transferred receivables is fully reflected on the Company’s balance sheet in accordance with GAAP.

Credit_Card_and_Student_Loan_S4

Credit Card and Student Loan Securitization Activities (Schedule of Investors' Interests and Related Excess Spreads) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Group Excess Spread Percentage [Member]	'
Variable Interest Entity [Line Items]	'
Three month rolling average excess spread	13.47%	[1]
DiscoverSeries Excess Spread Percentage [Member]	'
Variable Interest Entity [Line Items]	'
Three month rolling average excess spread	13.46%	[1]
Discover Card Master Trust I [Member]	'
Variable Interest Entity [Line Items]	'
Investors' interests	168	[2]
Number of series outstanding	2
Discover Card Execution Note Trust (DiscoverSeries Notes) [Member]	'
Variable Interest Entity [Line Items]	'
Investors' interests	19,454	[2]
Number of series outstanding	38
Trust By Name [Member]	'
Variable Interest Entity [Line Items]	'
Investors' interests	19,622	[2]
Number of series outstanding	40
[1]	DCMT certificates refer to the higher of the Group excess spread or their applicable series excess spread (not shown) and DiscoverSeries notes refer to the higher of the Group or DiscoverSeries excess spread in assessing whether an economic early amortization has been triggered.
[2]	Investors’ interests include third-party interests and subordinated interests held by wholly-owned subsidiaries of Discover Bank.

Credit_Card_and_Student_Loan_S5

Credit Card and Student Loan Securitization Activities (Schedule of Restricted Student Loan Securitized Assets) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Variable Interest Entity [Line Items]	'		'		'	'
Restricted cash	$1,163		$182		'	'
Student loan receivables	4,046		4,178		'	'
Allowance for loan losses allocated to securitized loan receivables	-1,591		-1,648		-1,634	-1,788
Variable Interest Entity, Primary Beneficiary [Member]	'		'		'	'
Variable Interest Entity [Line Items]	'		'		'	'
Restricted cash	1,160		179		'	'
Allowance for loan losses allocated to securitized loan receivables	-807		-861		'	'
Variable Interest Entity, Primary Beneficiary [Member] | Student Loan Securitization Trusts [Member]	'		'		'	'
Variable Interest Entity [Line Items]	'		'		'	'
Restricted cash	91		89		'	'
Student loan receivables	2,177		2,248		'	'
Allowance for loan losses allocated to securitized loan receivables	-28	[1]	-28	[1]	'	'
Net student loan receivables	2,149		2,220		'	'
Carrying value of assets of consolidated variable interest entities	$2,240		$2,309		'	'
[1]	The Company maintains its allowance for loan losses at an amount sufficient to absorb probable losses inherent in all loan receivables, which includes all loan receivables in the trusts. Therefore, credit risk associated with the transferred receivables is fully reflected on the Company’s balance sheet in accordance with GAAP.

Deposits_Narrative_Details

Deposits (Narrative) (Details) (USD $)	3 Months Ended
In Billions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
	channels
Deposits [Abstract]	'	'
Deposits source channels	2	'
Direct-to-consumer deposits	$28.70	$28.40
Brokered deposits	$16.10	$16.40

Deposits_Schedule_of_Interest_

Deposits (Schedule of Interest Bearing Deposit Accounts) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2014	Mar. 31, 2014
					Prior FDIC Insured Deposit Limit [Member]	Current FDIC Insured Deposit Limit [Member]
Deposits [Line Items]	'		'		'	'
Certificates of deposit in amounts less than $100,000	$20,832,000,000	[1]	$21,211,000,000	[1]	'	'
Certificates of deposit from amounts of $100,000 to less than $250,000	4,781,000,000	[1]	4,860,000,000	[1]	'	'
Certificates of deposit in amounts of $250,000 or greater	1,163,000,000	[1]	1,180,000,000	[1]	'	'
Savings deposits, including money market deposit accounts	18,037,000,000		17,515,000,000		'	'
Total interest-bearing deposits	44,813,000,000		44,766,000,000		'	'
Average annual interest rate	1.32%		1.57%		'	'
Basic deposit amount covered by FDIC insurance	'		'		$100,000	$250,000
[1]	$100,000 represents the basic insurance amount previously covered by the FDIC. Effective July 21, 2010, the basic insurance per depositor was permanently increased to $250,000.

Deposits_Schedule_of_Certifica

Deposits (Schedule of Certificates of Deposit Maturities) (Details) (USD $)	Mar. 31, 2014
In Millions, unless otherwise specified
Deposits [Abstract]	'
2014	$9,925
2015	7,444
2016	3,768
2017	2,310
2018	1,728
Thereafter	$1,601

LongTerm_Borrowings_Narrative_

Long-Term Borrowings (Narrative) (Details) (Discover Card Master Trust I and Discover Card Execution Note Trust [Member], Secured Debt [Member], USD $)	Mar. 31, 2014
Discover Card Master Trust I and Discover Card Execution Note Trust [Member] | Secured Debt [Member]	'
Debt Instrument [Line Items]	'
Total commitment of secured credit facilities	$7,500,000,000
Total used commitment of secured credit facilities	$0

LongTerm_Borrowings_Schedule_o

Long-Term Borrowings (Schedule of Long-Term Borrowings and Weighted Average Interest Rates) (Details) (USD $)

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2012

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

In Millions, unless otherwise specified

Secured Debt [Member]

Secured Debt [Member]

Capital Lease Obligations [Member]

Capital Lease Obligations [Member]

Fixed Rate Senior Notes Due April 2022 [Member]

Fixed Rate Senior Notes Due November 2022 [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

Discover Card Master Trust I and Discover Card Execution Note Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

SLC Private Student Loan Trust [Member]

Parent Company [Member]

Parent Company [Member]

Parent Company [Member]

Parent Company [Member]

Parent Company [Member]

Parent Company [Member]

Parent Company [Member]

Parent Company [Member]

Parent Company [Member]

Parent Company [Member]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Secured Debt [Member]

Secured Debt [Member]

Fixed Rate Asset Backed Securities [Member]

Fixed Rate Asset Backed Securities [Member]

Floating Rate Credit Card Asset Backed Securities 1-Month LIBOR Plus Various Basis Points [Member]

Floating Rate Credit Card Asset Backed Securities 1-Month LIBOR Plus Various Basis Points [Member]

Floating Rate Credit Card Asset Backed Securities 1-Month LIBOR Plus Various Basis Points [Member]

Floating Rate Credit Card Asset Backed Securities 1-Month LIBOR Plus Various Basis Points [Member]

Floating Rate Credit Card Asset Backed Securities 3-Month LIBOR Plus Various Basis Points [Member]

Floating Rate Credit Card Asset Backed Securities 3-Month LIBOR Plus Various Basis Points [Member]

Floating Rate Credit Card Asset Backed Securities 3-Month LIBOR Plus Various Basis Points [Member]

Floating Rate Asset Backed Securities Commercial Paper Rate Plus Various Basis Points [Member]

Floating Rate Asset Backed Securities Commercial Paper Rate Plus Various Basis Points [Member]

Floating Rate Asset Backed Securities Commercial Paper Rate Plus Various Basis Points [Member]

Secured Debt [Member]

Secured Debt [Member]

Floating Rate Asset-Backed Securities 3-month LIBOR plus various basis points [Member]

Floating Rate Asset-Backed Securities 3-month LIBOR plus various basis points [Member]

Floating Rate Asset-Backed Securities 3-month LIBOR plus various basis points [Member]

Floating Rate Asset-Backed Securities 3-month LIBOR plus various basis points [Member]

Floating Rate Asset-Backed Securities Prime Plus 100 Basis Points [Member]

Floating Rate Asset-Backed Securities Prime Plus 100 Basis Points [Member]

Floating Rate Asset-Backed Securities Prime Plus 100 Basis Points [Member]

Floating Rate Asset-Backed Securities Prime Plus 75 Basis Points [Member]

Floating Rate Asset-Backed Securities Prime Plus 75 Basis Points [Member]

Floating Rate Asset-Backed Securities Prime Plus 75 Basis Points [Member]

Floating Rate Asset-Backed Securities 1-month LIBOR Plus 350 Basis Points [Member]

Floating Rate Asset-Backed Securities 1-month LIBOR Plus 350 Basis Points [Member]

Floating Rate Asset-Backed Securities 1-month LIBOR Plus 350 Basis Points [Member]

Fixed Rate Senior Notes Due 2017 [Member]

Fixed Rate Senior Notes Due 2017 [Member]

Fixed Rate Senior Notes Due 2019 [Member]

Fixed Rate Senior Notes Due 2019 [Member]

Fixed Rate Senior Notes Due April 2022 [Member]

Fixed Rate Senior Notes Due April 2022 [Member]

Fixed Rate Senior Notes Due April 2022 [Member]

Fixed Rate Senior Notes Due November 2022 [Member]

Fixed Rate Senior Notes Due November 2022 [Member]

Fixed Rate Senior Notes Due November 2022 [Member]

Senior Bank Notes Due 2018 [Member]

Senior Bank Notes Due 2018 [Member]

Senior Bank Notes Due 2023 [Member]

Senior Bank Notes Due 2023 [Member]

Senior Bank Notes Due 2026 [Member]

Senior Bank Notes Due 2026 [Member]

Subordinated Bank Notes Due 2019 [Member]

Subordinated Bank Notes Due 2019 [Member]

Subordinated Bank Notes Due 2020 [Member]

Subordinated Bank Notes Due 2020 [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Secured Debt [Member]

Corporate Debt Securities [Member]

Corporate Debt Securities [Member]

Corporate Debt Securities [Member]

Corporate Debt Securities [Member]

Corporate Debt Securities [Member]

Corporate Debt Securities [Member]

Corporate Debt Securities [Member]

Corporate Debt Securities [Member]

Corporate Debt Securities [Member]

Corporate Debt Securities [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Subordinated Debt [Member]

Subordinated Debt [Member]

Subordinated Debt [Member]

Subordinated Debt [Member]

Minimum [Member]

Maximum [Member]

London Interbank Offered Rate (LIBOR) [Member]

Commercial Paper Rate [Member]

Minimum [Member]

Maximum [Member]

Prime Rate [Member]

Prime Rate [Member]

London Interbank Offered Rate (LIBOR) [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Discount

'

'

'

'

'

'

'

'

'

'

$1

$1

'

'

'

'

'

'

'

'

'

'

'

'

$118

$129

'

'

$2

$3

'

'

'

'

'

'

'

'

'

'

'

$101

'

$103

$162

'

$165

'

'

$6

$6

$1

$0

'

'

$2

$2

Premium

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

1

'

3

3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal value

'

'

'

'

'

'

'

'

'

'

5,549

5,549

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

400

400

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair value adjustment

'

'

'

'

'

'

'

'

'

'

5

[1]

5

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8

[1]

13

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term borrowings

20,182

20,474

16,295

16,986

1

1

'

'

14,593

15,194

5,554

5,554

8,189

9,140

'

'

850

0

'

0

500

'

1,702

1,792

959

1,005

'

'

410

434

'

100

105

'

233

248

'

408

413

78

78

221

[2]

'

219

[2]

338

[3]

'

335

[3]

750

750

994

994

399

0

200

200

498

498

Interest rate

'

'

'

'

4.51%

4.51%

'

'

'

'

1.86%

1.86%

0.47%

0.46%

'

'

0.40%

0.00%

'

0.00%

0.44%

'

'

'

0.48%

0.48%

'

'

4.25%

4.25%

'

4.00%

4.00%

'

3.66%

3.66%

'

6.45%

6.45%

10.25%

10.25%

5.20%

'

5.20%

3.85%

'

3.85%

2.00%

2.00%

4.20%

4.20%

4.25%

0.00%

8.70%

8.70%

7.00%

7.00%

Interest rate terms

'

'

'

'

'Fixed

'

'

'

'

'

'Various fixed rates

'

'1-month LIBOR(2) + 15 to 58 basis points

[4]

'

'

'

'3-month LIBOR(2) + 20 basis points

[4]

'

'

'Commercial Paper rate + 30 basis points

'

'

'

'

'3-month LIBOR(2) + 12 to 45 basis points

[4]

'

'

'

'Prime rate + 100 basis points

'

'

'Prime rate + 75 basis points

'

'

'1-month LIBOR(2) + 350 basis points

[4]

'

'

'Fixed

'

'Fixed

'

'Fixed

'

'

'Fixed

'

'

'Fixed

'

'Fixed

'

'Fixed

'

'Fixed

'

'Fixed

'

Basis spread on variable rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.15%

0.58%

'

'

0.20%

'

'

0.30%

'

'

'

'

0.12%

0.45%

'

'

1.00%

'

'

0.75%

'

'

3.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maturity

'

'

'

'

'April 2016

'

'

'

'

'

'Various February 2015 - July 2019

'

'Various April 2014 - January 2019

'

'

'

'February 2017

'

'

'March 2014

'

'

'

'

'Various January 2019 - July 2036 (3)

[5]

'

'

'

'June 2031 (3)

[5]

'

'

'July 2042 (3)

[5]

'

'

'July 2042 (3)

[5]

'

'

'June 2017

'

'July 2019

'

'April 2022

'

'

'November 2022

'

'

'February 2018

'

'August 2023

'

'March 2026

'

'November 2019

'

'April 2020

'

Maturity range, start

'

'

'

'

'

'

'

'

'

'

28-Feb-15

'

30-Apr-14

'

'

'

'

'

'

'

'

'

'

'

31-Jan-19

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maturity range, end

'

'

'

'

'

'

'

'

'

'

31-Jul-19

'

31-Jan-19

'

'

'

'

'

'

'

'

'

'

'

31-Jul-36

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash premium paid on debt exchange

'

'

'

'

'

'

115

176

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

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'

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'

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'

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'

'

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'

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'

'

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'

'

'

'

'

'

'

'

Amortization of premium paid on debt exchange

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$2

$2

'

$3

$3

'

'

'

'

'

'

'

'

'

'

'

[1]

The Company uses interest rate swaps to hedge portions of these long-term borrowings against changes in fair value attributable to changes in LIBOR. See Note 14: Derivatives and Hedging Activities.

[2]

Discount primarily relates to $115 million cash premium paid at issuance as part of 2012 private exchange offer to replace higher rate borrowings with borrowings bearing lower interest rates. During the three months ended March 31, 2014 and 2013, respectively, $2 million of the premium paid was amortized and included in interest expense in the condensed consolidated statements of income.

[3]

Discount primarily relates to $176 million cash premium paid at issuance as part of 2012 private exchange offer to replace higher rate borrowings with borrowings bearing lower interest rates. During the three months ended March 31, 2014 and 2013. respectively, $3 million of the premium paid was amortized and included in interest expense in the condensed consolidated statements of income.

[4]

London Interbank Offered Rate (“LIBOR”).

[5]

Repayment of this debt is dependent upon the timing of principal and interest payments on the underlying student loans. The dates shown represent final maturity dates.

LongTerm_Borrowings_LongTerm_B

Long-Term Borrowings Long-Term Borrowings (Schedule of Long-Term Borrowings Maturities)) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Debt Disclosure [Abstract]	'	'
Due in 2014	$2,040	'
Due in 2015	3,305	'
Due in 2016	3,050	'
Due in 2017	2,908	'
Due in 2018	2,650	'
Thereafter	6,229	'
Long-term borrowings	$20,182	$20,474

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income Accumulated Other Comprehensive Income (Schedule of Changes in Accumulated Other Comprehensive Income (Loss)) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Accumulated Other Comprehensive Income Loss [Roll Forward]	'		'
Accumulated other comprehensive income (loss), balance at beginning of period, net of tax	($68)		($72)
Net change in accumulated other comprehensive income (loss), net of tax	-2		-12
Accumulated other comprehensive income (loss), balance at end of period, net of tax	-70		-84
Accumulated Net Unrealized Investment Gain (Loss) [Member]	'		'
Accumulated Other Comprehensive Income Loss [Roll Forward]	'		'
Accumulated other comprehensive income (loss), balance at beginning of period, net of tax	19		71
Net change in accumulated other comprehensive income (loss), net of tax	2		-11
Accumulated other comprehensive income (loss), balance at end of period, net of tax	21		60
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	'		'
Accumulated Other Comprehensive Income Loss [Roll Forward]	'		'
Accumulated other comprehensive income (loss), balance at beginning of period, net of tax	13		3
Net change in accumulated other comprehensive income (loss), net of tax	-4		-1
Accumulated other comprehensive income (loss), balance at end of period, net of tax	9		2
Accumulated Translation Adjustment [Member]	'		'
Accumulated Other Comprehensive Income Loss [Roll Forward]	'		'
Accumulated other comprehensive income (loss), balance at beginning of period, net of tax	1	[1]	0	[1]
Net change in accumulated other comprehensive income (loss), net of tax	0	[1]	0	[1]
Accumulated other comprehensive income (loss), balance at end of period, net of tax	1	[1]	0	[1]
Accumulated Defined Benefit Plans Adjustment [Member]	'		'
Accumulated Other Comprehensive Income Loss [Roll Forward]	'		'
Accumulated other comprehensive income (loss), balance at beginning of period, net of tax	-101		-146
Net change in accumulated other comprehensive income (loss), net of tax	0		0
Accumulated other comprehensive income (loss), balance at end of period, net of tax	($101)		($146)
[1]	Includes unrealized losses on hedge of net investment in foreign subsidiary, net of tax benefit and net gains on foreign currency translation adjustments.

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income Accumulated Other Comprehensive Income (Schedule of Other Comprehensive Income Before Reclassifications and Amounts Reclassified from AOCI) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
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	$7	($14)
Available-for-sale investment securities, net unrealized holding gains (losses) arising during the period, tax	-3	5
Available-for-sale investment securities, net unrealized holding gains (losses) arising during the period, net of tax	4	-9
Available-for-sale investment securities, amounts reclassified from accumulated other comprehensive income, before tax	-4	-2
Available-for-sale investment securities, amounts reclassified from accumulated other comprehensive income, tax	2	0
Available-for-sale investment securities, amounts reclassified from other comprehensive income, net of tax	-2	-2
Available-for-sale investment securities, other comprehensive income (loss), before tax	3	-16
Available-for-sale investment securities, other comprehensive income (loss), tax	-1	5
Available-for-sale investment securities, other comprehensive income (loss), net of tax	2	-11
Cash flow hedges, net unrealized losses arising during the period, before tax	-13	'
Cash flow hedges, net unrealized losses arising during the period, tax	5	'
Cash flow hedges, net unrealized losses arising during the period, net of tax	-8	'
Cash flow hedges, amounts reclassified from accumulated other comprehensive income, before tax	7	-2
Cash flow hedges, amounts reclassified from accumulated other comprehensive income, tax	-3	1
Cash flow hedges, amounts reclassified from accumulated other comprehensive income, net of tax	4	-1
Cash flow hedges, other comprehensive income (loss), before tax	-6	-2
Cash flow hedges, other comprehensive income (loss), tax	2	1
Cash flow hedges, other comprehensive income (loss), net of tax	($4)	($1)

Income_Taxes_Income_Taxes_Narr

Income Taxes Income Taxes (Narrative) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]	'	'
Change in income tax expense	($16)	'
Effective income tax rate	38.30%	37.70%
Period within which resolution of tax appeal is reasonably possible	'12 months	'
Reduction in the amount of unrecognized tax benefits as a result of settlement that is reasonable possible	$99	'

Income_Taxes_Schedule_of_Recon

Income Taxes (Schedule of Reconciliation of the Company's Effective Tax Rate to the U.S. Federal Statutory Income Tax Rate) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]	'	'
Income before income tax expense	$1,022	$1,080
Income tax expense	$391	$407
Effective income tax rate	38.30%	37.70%

Earnings_Per_Share_Schedule_of

Earnings Per Share (Schedule of Basic and Diluted EPS ) (Details) (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Numerator:	'	'
Net income	$631	$673
Preferred stock dividends	-9	-9
Net income available to common stockholders	622	664
Income allocated to participating securities	-4	-5
Net income allocated to common stockholders	$618	$659
Denominator:	'	'
Weighted average shares of common stock outstanding (in shares)	471	496
Effect of dilutive common stock equivalents (in shares)	1	1
Weighted average shares of common stock outstanding and common stock equivalents (in shares)	472	497
Basic earnings per common share (in dollars per share)	$1.31	$1.33
Diluted earnings per common share (in dollars per share)	$1.31	$1.33

Capital_Adequacy_Schedule_of_M

Capital Adequacy (Schedule of Minimum and Well-Capitalized Requirements) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Parent Company [Member]	'	'
Compliance with Regulatory Capital Requirements [Line Items]	'	'
Total capital to risk-weighted assets, actual amount	$12,175	$11,975
Total capital to risk-weighted assets, actual ratio	18.10%	17.40%
Total capital to risk-weighted assets, minimum capital requirements, amount	5,389	5,492
Total capital to risk-weighted assets, minimum capital requirements, ratio	8.00%	8.00%
Total capital to risk-weighted assets, capital requirements to be classified as well-capitalized, amount	6,736	6,865
Total capital to risk-weighted assets, capital requirements to be classified as well-capitalized, ratio	10.00%	10.00%
Tier I capital to risk-weighted assets, actual amount	10,626	10,409
Tier I capital to risk-weighted assets, actual ratio	15.80%	15.20%
Tier I capital to risk-weighted assets, minimum capital requirements, amount	2,695	2,746
Tier I capital to risk-weighted assets, minimum capital requirements, ratio	4.00%	4.00%
Tier I capital to risk-weighted assets, capital requirements to be classified as well-capitalized, amount	4,042	4,119
Tier I capital to risk-weighted assets, capital requirements to be classified as well-capitalized, ratio	6.00%	6.00%
Tier I capital to average assets, actual amount	10,626	10,409
Tier I capital to average assets, actual ratio	13.40%	13.40%
Tier I capital to average assets, minimum capital requirements, amount	3,173	3,116
Tier I capital to average assets, minimum capital requirements, ratio	4.00%	4.00%
Tier I capital to average assets, capital requirements to be classified as well-capitalize, amount	3,966	3,895
Tier I capital to average assets, capital requirements to be classified as well-capitalize, ratio	5.00%	5.00%
Discover Bank [Member]	'	'
Compliance with Regulatory Capital Requirements [Line Items]	'	'
Total capital to risk-weighted assets, actual amount	10,705	10,496
Total capital to risk-weighted assets, actual ratio	16.10%	15.50%
Total capital to risk-weighted assets, minimum capital requirements, amount	5,324	5,428
Total capital to risk-weighted assets, minimum capital requirements, ratio	8.00%	8.00%
Total capital to risk-weighted assets, capital requirements to be classified as well-capitalized, amount	6,655	6,785
Total capital to risk-weighted assets, capital requirements to be classified as well-capitalized, ratio	10.00%	10.00%
Tier I capital to risk-weighted assets, actual amount	9,166	8,941
Tier I capital to risk-weighted assets, actual ratio	13.80%	13.20%
Tier I capital to risk-weighted assets, minimum capital requirements, amount	2,662	2,714
Tier I capital to risk-weighted assets, minimum capital requirements, ratio	4.00%	4.00%
Tier I capital to risk-weighted assets, capital requirements to be classified as well-capitalized, amount	3,993	4,071
Tier I capital to risk-weighted assets, capital requirements to be classified as well-capitalized, ratio	6.00%	6.00%
Tier I capital to average assets, actual amount	9,166	8,941
Tier I capital to average assets, actual ratio	11.70%	11.60%
Tier I capital to average assets, minimum capital requirements, amount	3,137	3,077
Tier I capital to average assets, minimum capital requirements, ratio	4.00%	4.00%
Tier I capital to average assets, capital requirements to be classified as well-capitalize, amount	$3,921	$3,847
Tier I capital to average assets, capital requirements to be classified as well-capitalize, ratio	5.00%	5.00%

Commitments_Contingencies_and_2

Commitments, Contingencies and Guarantees (Narrative) (Details) (USD $)	Mar. 31, 2014
ATM Guarantee [Member] | Citishare Network Guarantee [Member]	'
Commitments, Contingencies and Guarantees [Line Items]	'
Maximum potential future payment	$15,000,000
Commitments to Extend Credit [Member]	'
Commitments, Contingencies and Guarantees [Line Items]	'
Unused commitments to extend credit for loans	$166,500,000,000

Commitments_Contingencies_and_3

Commitments, Contingencies and Guarantees (Schedule of Lease Commitments) (Details) (USD $)	Mar. 31, 2014
In Millions, unless otherwise specified
Capital Leases, Future Minimum Payments Due [Abstract]	'
2014, capitalized Leases	$0
2015, capitalized Leases	1
2016, capitalized Leases	0
2017, capitalized Leases	0
2018, capitalized Leases	0
Thereafter, capitalized Leases	0
Total minimum lease payments, capitalized leases	1
Less: amount representing interest, capitalized leases	0
Present value of net minimum lease payments, capitalized leases	1
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]	'
2014, operating leases	12
2015, operating leases	13
2016, operating leases	12
2017, operating leases	10
2018, operating leases	7
Thereafter, operating leases	12
Total minimum lease payments, operating leases	$66

Commitments_Contingencies_and_4

Commitments, Contingencies and Guarantees (Schedule of Maximum Potential Counterparty Exposures Related to Settlement Guarantees and Merchant Chargeback Guarantee) (Details) (USD $)	Mar. 31, 2014
In Millions, unless otherwise specified
Merchant Guarantee [Member] | Diners Club [Member]	'
Guarantor Obligations [Line Items]	'
Maximum potential counterparty exposures to settlement guarantees	$173
ATM Guarantee [Member] | PULSE [Member]	'
Guarantor Obligations [Line Items]	'
Maximum potential counterparty exposures to settlement guarantees	$1

Commitments_Contingencies_and_5

Commitments, Contingencies and Guarantees (Schedule of Merchant Chargeback Guarantee) (Details) (Merchant Chargebacks [Member], USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Merchant Chargebacks [Member]	'		'
Loss Contingencies [Line Items]	'		'
Aggregate sales transaction volume	$28,154	[1]	$27,228	[1]
[1]	Represents period transactions processed on the Discover Network for which a potential liability exists that, in aggregate, can differ from credit card sales volume.

Commitments_Contingencies_and_6

Commitments, Contingencies and Guarantees (Schedule of Settlement Withholdings and Escrow Deposits) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Commitments Contingencies and Guarantees [Abstract]	'	'
Settlement withholdings and escrow deposits	$21	$17

Litigation_Details

Litigation (Details) (USD $)	3 Months Ended	0 Months Ended
	Mar. 31, 2014	Mar. 06, 2012	Mar. 06, 2012	Mar. 31, 2014
	Cases Involving Violation of TCPA [Member]	Cases Involving Violation of TCPA [Member]	Cases Involving Violation of TCPA [Member]	Pending and Threatened Litigation [Member]
	cases	Violation [Member]	Willful violation [Member]
Litigation Disclosures [Line Items]	'	'	'	'
Maximum aggregate reasonably possible losses	'	'	'	$160,000,000
Number of pending class action cases	2	'	'	'
Sought statutory damages	'	$500	$1,500	'

Fair_Value_Measurements_and_Di2

Fair Value Measurements and Disclosures (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Aggregate unpaid principal balance of loans held for sale, fair value option	$129,000,000	'	$146,000,000
Fair value of loans held for sale	133,000,000	'	148,000,000
Gain (loss) from fair value adjustments on loans held for sale	-5,000,000	6,000,000	'
Residential Mortgage Backed Securities [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Available for sale security, par value	1,500,000,000	'	'
Available for sale securities, weighted average coupon rate	2.79%	'	'
Available for sale securities, weighted average remaining maturity	'4 years	'	'
Fair Value, Measurements, Recurring [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Asset transfers from level 1 to level 2 within the fair value hierarchy	0	0	'
Asset transfers from level 2 to level 1 within the fair value hierarchy	0	0	'
Liability transfers from level 1 to level 2 within the fair value hierarchy	0	0	'
Liability transfers from level 2 to level 1 within the fair value hierarchy	$0	$0	'

Fair_Value_Measurements_and_Di3

Fair Value Measurements and Disclosures (Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) (Fair Value, Measurements, Recurring [Member], USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	$3,902	$4,931
Mortgage loans held for sale, fair value	133	148
Derivative financial instruments, assets, fair value	73	79
Derivative financial instruments, liabilities, fair value	8	7
Interest Rate Lock Commitments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets, fair value	5	4
Forward Contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets, fair value	1	5
Derivative financial instruments, liabilities, fair value	1	1
Other Derivative Financial Instruments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets, fair value	67	70
Derivative financial instruments, liabilities, fair value	7	6
US Treasury Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	1,342	2,057
US Government Corporations and Agencies Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	1,047	1,561
Credit Card Asset-Backed Securities of Other Issuers [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	'	6
Residential Mortgage Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	1,513	1,307
Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	2,389	3,618
Mortgage loans held for sale, fair value	0	0
Derivative financial instruments, assets, fair value	0	0
Derivative financial instruments, liabilities, fair value	0	0
Level 1 [Member] | Interest Rate Lock Commitments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets, fair value	0	0
Level 1 [Member] | Forward Contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets, fair value	0	0
Derivative financial instruments, liabilities, fair value	0	0
Level 1 [Member] | Other Derivative Financial Instruments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets, fair value	0	0
Derivative financial instruments, liabilities, fair value	0	0
Level 1 [Member] | US Treasury Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	1,342	2,057
Level 1 [Member] | US Government Corporations and Agencies Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	1,047	1,561
Level 1 [Member] | Credit Card Asset-Backed Securities of Other Issuers [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	'	0
Level 1 [Member] | Residential Mortgage Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	0	0
Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	1,513	1,313
Mortgage loans held for sale, fair value	133	148
Derivative financial instruments, assets, fair value	68	75
Derivative financial instruments, liabilities, fair value	8	7
Level 2 [Member] | Interest Rate Lock Commitments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets, fair value	0	0
Level 2 [Member] | Forward Contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets, fair value	1	5
Derivative financial instruments, liabilities, fair value	1	1
Level 2 [Member] | Other Derivative Financial Instruments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets, fair value	67	70
Derivative financial instruments, liabilities, fair value	7	6
Level 2 [Member] | US Treasury Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	0	0
Level 2 [Member] | US Government Corporations and Agencies Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	0	0
Level 2 [Member] | Credit Card Asset-Backed Securities of Other Issuers [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	'	6
Level 2 [Member] | Residential Mortgage Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	1,513	1,307
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
Mortgage loans held for sale, fair value	0	0
Derivative financial instruments, assets, fair value	5	4
Derivative financial instruments, liabilities, fair value	0	0
Level 3 [Member] | Interest Rate Lock Commitments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets, fair value	5	4
Level 3 [Member] | Forward Contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets, fair value	0	0
Derivative financial instruments, liabilities, fair value	0	0
Level 3 [Member] | Other Derivative Financial Instruments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets, fair value	0	0
Derivative financial instruments, liabilities, fair value	0	0
Level 3 [Member] | US Treasury Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	0	0
Level 3 [Member] | US Government Corporations and Agencies Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	0	0
Level 3 [Member] | Credit Card Asset-Backed Securities of Other Issuers [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	'	0
Level 3 [Member] | Residential Mortgage Backed Securities [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_Measurements_and_Di4

Fair Value Measurements and Disclosures (Schedule of Changes in Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Interest Rate Lock Commitments [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Level 3 assets and liabilities, balance at beginning of period	$4	$12
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Total net gains included in earnings	18	48
Purchases	0	0
Sales	0	0
Settlements	0	3
Transfers of IRLCs to closed loans	-17	-49
Level 3 assets and liabilities, balance at end of period	5	14
Forward Contracts [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Level 3 assets and liabilities, balance at beginning of period	0	'
Transfers into Level 3	0	'
Transfers out of Level 3	-1	'
Total net gains included in earnings	1	'
Purchases	0	'
Sales	0	'
Settlements	0	'
Transfers of IRLCs to closed loans	0	'
Level 3 assets and liabilities, balance at end of period	0	'
Mortgage Loans Held For Sale [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Level 3 assets and liabilities, balance at beginning of period	0	0
Transfers into Level 3	1	1
Transfers out of Level 3	0	0
Total net gains included in earnings	0	0
Purchases	0	0
Sales	-1	0
Settlements	0	0
Transfers of IRLCs to closed loans	0	0
Level 3 assets and liabilities, balance at end of period	$0	$1

Fair_Value_Measurements_and_Di5

Fair Value Measurements and Disclosures Fair Value Measurements and Disclosures (Schedule of Significant Unobservable Inputs Related to Level 3 Assets and Liabilities) (Details) (Interest Rate Lock Commitments [Member], USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014
In Millions, unless otherwise specified					Fair Value, Inputs, Level 3 [Member]	Fair Value, Inputs, Level 3 [Member]	Fair Value, Inputs, Level 3 [Member]	Fair Value, Inputs, Level 3 [Member]	Fair Value, Inputs, Level 3 [Member]
					Quantitative Risk Model [Member]	Quantitative Risk Model [Member]	Quantitative Risk Model [Member]	Quantitative Risk Model [Member]	Quantitative Risk Model [Member]
						Loan Funding Probability [Member]	Loan Funding Probability [Member]	Loan Funding Probability [Member]	Loan Funding Probability [Member]
							Minimum [Member]	Maximum [Member]	Weighted Average [Member]
Significant Unobservable Inputs Related to Level 3 Assets and Liabilties [Line Items]	'	'	'	'	'	'	'	'	'
Significant unobservable inputs, fair value (in dollars)	$5	$4	$14	$12	'	'	'	'	'
Significant unobservable inputs, valuation technique	'	'	'	'	'Quantitative risk models	'	'	'	'
Significant unobservable inputs, significant unobservable input	'	'	'	'	'	'Loan funding probability	'	'	'
Significant unobservable inputs, ranges of inputs	'	'	'	'	'	'	8.00%	100.00%	59.00%	[1]
[1]	Weighted averages are calculated using notional amounts for derivative instruments.

Fair_Value_Measurements_and_Di6

Fair Value Measurements and Disclosures Fair Value Measurements and Disclosures (Schedule of Financial Instruments Measured at Other Than Fair Value) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	$62	[1]	$58	[1]
Fair Value, Measurements, Nonrecurring [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	62		58
Cash and cash equivalents	8,731		6,554
Restricted cash	1,163		182
Net loan receivables	49,785	[2]	64,968	[2]
Accrued interest receivables	560		556
Deposits	45,232		45,231
Short-term borrowings	124		140
Accrued interest payables	129		117
Fair Value, Measurements, Nonrecurring [Member] | Variable Interest Entity, Primary Beneficiary [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Long-term borrowings	16,584		17,283
Fair Value, Measurements, Nonrecurring [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Long-term borrowings	4,411		3,935
Fair Value, Measurements, Nonrecurring [Member] | US Treasury Securities [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	1		1
Fair Value, Measurements, Nonrecurring [Member] | States and political subdivisions of states	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	10		14
Fair Value, Measurements, Nonrecurring [Member] | Residential Mortgage Backed Securities [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	51		43
Fair Value, Measurements, Nonrecurring [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	62		60
Cash and cash equivalents	8,731		6,554
Restricted cash	1,163		182
Net loan receivables	62,128	[2]	63,975	[2]
Accrued interest receivables	560		556
Deposits	44,984		44,959
Short-term borrowings	124		140
Accrued interest payables	129		117
Fair Value, Measurements, Nonrecurring [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member] | Variable Interest Entity, Primary Beneficiary [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Long-term borrowings	16,295		16,986
Fair Value, Measurements, Nonrecurring [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Long-term borrowings	3,887		3,488
Fair Value, Measurements, Nonrecurring [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member] | US Treasury Securities [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	1		1
Fair Value, Measurements, Nonrecurring [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member] | States and political subdivisions of states	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	10		15
Fair Value, Measurements, Nonrecurring [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member] | Residential Mortgage Backed Securities [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	51		44
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	1		1
Cash and cash equivalents	8,731		6,554
Restricted cash	1,163		182
Net loan receivables	0	[2]	0	[2]
Accrued interest receivables	0		0
Deposits	0		0
Short-term borrowings	0		0
Accrued interest payables	0		0
Fair Value, Measurements, Nonrecurring [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
Fair Value, Measurements, Nonrecurring [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
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member] | US Treasury Securities [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	1		1
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member] | States and political subdivisions of states	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	0		0
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member] | Residential Mortgage Backed Securities [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	0		0
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	61		57
Cash and cash equivalents	0		0
Restricted cash	0		0
Net loan receivables	0	[2]	0	[2]
Accrued interest receivables	560		556
Deposits	45,232		45,231
Short-term borrowings	124		140
Accrued interest payables	129		117
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member] | Variable Interest Entity, Primary Beneficiary [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Long-term borrowings	14,731		15,312
Fair Value, Measurements, Nonrecurring [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	4,410		3,934
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member] | US Treasury Securities [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	0		0
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member] | States and political subdivisions of states	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	10		14
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member] | Residential Mortgage Backed Securities [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	51		43
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	0		0
Cash and cash equivalents	0		0
Restricted cash	0		0
Net loan receivables	49,785	[2]	64,968	[2]
Accrued interest receivables	0		0
Deposits	0		0
Short-term borrowings	0		0
Accrued interest payables	0		0
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Variable Interest Entity, Primary Beneficiary [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Long-term borrowings	1,853		1,971
Fair Value, Measurements, Nonrecurring [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	1		1
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | US Treasury Securities [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	0		0
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | States and political subdivisions of states	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	0		0
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Residential Mortgage Backed Securities [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	$0		$0
[1]	Held-to-maturity investment securities are reported at amortized cost.
[2]	Net loan receivables exclude mortgage loans held for sale that are measured at fair value on a recurring basis.

Derivatives_and_Hedging_Activi2

Derivatives and Hedging Activities (Narrative) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Derivative [Line Items]	'
Additional collateral	$107
Credit Rating Did Not Meet Specified Threshold [Member]	'
Derivative [Line Items]	'
Cash collateral posted	4
Interest Expense [Member]	'
Derivative [Line Items]	'
Cash flow hedge loss to be reclassified to earnings within twelve months	$30
Credit Card Receivable [Member]	'
Derivative [Line Items]	'
Initial maximum period for cash flow hedges	'3 years
Secured Debt [Member]	'
Derivative [Line Items]	'
Initial maximum period for cash flow hedges	'5 years
Deposits [Member]	'
Derivative [Line Items]	'
Initial maximum period for cash flow hedges	'7 years

Derivatives_and_Hedging_Activi3

Derivatives and Hedging Activities (Schedule of Fair Value and Related Outstanding Notional Amounts of Derivative Instruments) (Details)

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

In Millions, unless otherwise specified

USD ($)

USD ($)

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Not designated as hedges [Member]

Cash Flow Hedge [Member]

Cash Flow Hedge [Member]

Cash Flow Hedge [Member]

Cash Flow Hedge [Member]

Cash Flow Hedge [Member]

Cash Flow Hedge [Member]

Fair Value Hedge [Member]

Fair Value Hedge [Member]

Fair Value Hedge [Member]

Fair Value Hedge [Member]

Fair Value Hedge [Member]

Fair Value Hedge [Member]

Net Investment Hedging [Member]

Net Investment Hedging [Member]

Net Investment Hedging [Member]

Net Investment Hedging [Member]

Net Investment Hedging [Member]

Net Investment Hedging [Member]

Net Investment Hedging [Member]

Net Investment Hedging [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Forward Contracts [Member]

Forward Contracts [Member]

Forward Contracts [Member]

Forward Contracts [Member]

Forward Contracts [Member]

Forward Contracts [Member]

Interest Rate Lock Commitments [Member]

Interest Rate Lock Commitments [Member]

Interest Rate Lock Commitments [Member]

Interest Rate Lock Commitments [Member]

Interest Rate Lock Commitments [Member]

Interest Rate Lock Commitments [Member]

When-Issued Forward Contracts [Member]

When-Issued Forward Contracts [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

Foreign Exchange Forward Contracts [Member]

USD ($)

USD ($)

Other Assets [Member]

Other Assets [Member]

Other Liabilities [Member]

Other Liabilities [Member]

USD ($)

CHF

EUR (€)

GBP (£)

SGD

USD ($)

CHF

EUR (€)

GBP (£)

SGD

Other Assets [Member]

Other Assets [Member]

Other Liabilities [Member]

Other Liabilities [Member]

USD ($)

USD ($)

Other Assets [Member]

Other Assets [Member]

Other Liabilities [Member]

Other Liabilities [Member]

USD ($)

USD ($)

Other Assets [Member]

Other Assets [Member]

Other Liabilities [Member]

Other Liabilities [Member]

USD ($)

USD ($)

USD ($)

USD ($)

Other Assets [Member]

Other Assets [Member]

Other Liabilities [Member]

Other Liabilities [Member]

USD ($)

USD ($)

Other Assets [Member]

Other Assets [Member]

Other Liabilities [Member]

Other Liabilities [Member]

USD ($)

EUR (€)

USD ($)

EUR (€)

Other Assets [Member]

Other Assets [Member]

Other Liabilities [Member]

Other Liabilities [Member]

transactions

USD ($)

USD ($)

USD ($)

USD ($)

transactions

USD ($)

USD ($)

USD ($)

USD ($)

transactions

USD ($)

USD ($)

USD ($)

USD ($)

transactions

USD ($)

USD ($)

USD ($)

USD ($)

transactions

transactions

USD ($)

USD ($)

USD ($)

USD ($)

transactions

USD ($)

USD ($)

USD ($)

USD ($)

transactions

USD ($)

USD ($)

USD ($)

USD ($)

Derivatives, Fair Value [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative, notional amount

'

'

$2,950

$2,650

'

'

'

'

$6,686

$7,138

'

'

'

'

$33

[1]

€ 24

[1]

$35

[1]

€ 26

[1]

'

'

'

'

$446

[2]

$796

[2]

'

'

'

'

$43

[3]

6

€ 21

£ 4

2

$44

[3]

5

€ 20

£ 6

1

'

'

'

'

$560

$693

'

'

'

'

$302

[2]

$235

[2]

'

'

'

'

$32

$40

Derivative, number of transactions (in transations)

'

'

6

'

'

'

'

'

218

'

'

'

'

'

1

1

'

'

'

'

'

'

1

[2]

'

'

'

'

'

9

9

9

9

9

'

'

'

'

'

'

'

'

'

453

'

'

'

'

'

1,365

[2]

'

'

'

'

'

1

'

Derivative, other assets (at fair value)

73

[4]

79

[4]

'

'

13

18

'

'

'

'

54

52

'

'

'

'

'

'

0

0

'

'

'

'

0

[2]

0

[2]

'

'

'

'

'

'

'

'

'

'

'

'

0

0

'

'

'

'

1

5

'

'

'

'

5

[2]

4

[2]

'

'

'

'

Collateral receivable/payable, other assets (at fair value)

-57

[5]

-61

[5]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total net derivative assets

16

18

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative, accrued expenses and other liabilities (at fair value)

8

[4]

7

[4]

'

'

'

'

1

0

'

'

'

'

6

6

'

'

'

'

'

'

0

0

'

'

'

'

0

[2]

0

[2]

'

'

'

'

'

'

'

'

'

'

'

'

0

0

'

'

'

'

1

1

'

'

'

'

0

[2]

0

[2]

'

'

Collateral receivable/payable, accrued expenses and other liabilities (at fair value)

-8

[5]

-7

[5]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total net derivative liabilities

$0

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

The foreign exchange forward contract has a notional amount of EUR 24 million and EUR 26 million as of March 31, 2014 and December 31, 2013, respectively.

[2]

Interest rate swaps not designated as hedges and interest rate lock commitments do not have associated master netting arrangements.

[3]

The foreign exchange forward contracts have notional amounts of EUR 21 million, GBP 4 million, SGD 2 million, and CHF 6 million as of March 31, 2014, and EUR 20 million, GBP 6 million, SGD 1 million, CHF 5 million as of December 31, 2013.

[4]

In addition to the derivatives disclosed in the table, the Company had one outstanding forward contract to purchase when-issued mortgage-backed securities as part of our community reinvestment initiatives. This forward contract had a notional amount of $32 million and $40 million and immaterial fair values as of March 31, 2014 and December 31, 2013, respectively.

[5]

Collateral amounts, which consist of both cash and investment securities, are limited to the related derivative asset/liability balance and do not include excess collateral received/pledged.

Derivatives_and_Hedging_Activi4

Derivatives and Hedging Activities (Schedule of Impact of the Derivative Instruments on Income) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Designated as hedges [Member] | Cash Flow Hedging [Member] | Interest Rate Swap [Member] | Other Comprehensive Income [Member]	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Total gains (losses) recognized in other comprehensive income after amounts reclassified into earnings, pretax, interest rate swaps, cash flow hedges	($6)	($2)
Designated as hedges [Member] | Cash Flow Hedging [Member] | Interest Rate Swap [Member] | Interest Income [Member]	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Amount reclassified from other comprehensive income into income, interest rate swaps, cash flow hedges	0	2
Designated as hedges [Member] | Cash Flow Hedging [Member] | Interest Rate Swap [Member] | Interest Expense [Member]	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Amount reclassified from other comprehensive income into income, interest rate swaps, cash flow hedges	-7	0
Designated as hedges [Member] | Fair Value Hedging [Member] | Interest Expense [Member]	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Gain (loss) on derivatives	7	12
Designated as hedges [Member] | Fair Value Hedging [Member] | Hedged Item [Member] | Interest Expense [Member]	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Interest expense - ineffectiveness, interest rate swaps, fair value hedges	3	9
Interest expense - other, interest rate swaps, fair value hedges	3	-1
Gain on hedged item	6	8
Designated as hedges [Member] | Fair Value Hedging [Member] | Interest Rate Swap [Member] | Derivative [Member] | Interest Expense [Member]	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Interest expense - ineffectiveness, interest rate swaps, fair value hedges	-2	-8
Interest expense - other, interest rate swaps, fair value hedges	10	10
Gain (loss) on derivatives	8	2
Not designated as hedges [Member]	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Gain (loss) on derivatives	14	49
Not designated as hedges [Member] | Interest Rate Swap [Member] | Other Income	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Gain (loss) on derivatives	-1	0
Not designated as hedges [Member] | Foreign Exchange Forward [Member] | Other Income	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Gain (loss) on derivatives	0	2
Not designated as hedges [Member] | Forward Contracts [Member] | Other Income	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Gain (loss) on derivatives	-3	-1
Not designated as hedges [Member] | Interest Rate Lock Commitments [Member] | Other Income	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Gain (loss) on derivatives	$18	$48

Segment_Disclosures_Narrative_

Segment Disclosures (Narrative) (Details)	3 Months Ended
	Mar. 31, 2014
	segment
Segment Reporting [Abstract]	'
Number of reportable segments	2

Segment_Disclosures_Schedule_o

Segment Disclosures (Schedule of Segment Disclosures) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]	'	'
Interest income	$1,833	$1,708
Interest expense	270	298
Net interest income	1,563	1,410
Provision for loan losses	272	159
Other income	515	582
Other expense	784	753
Income before income tax expense	1,022	1,080
Direct Banking [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	1,833	1,708
Interest expense	270	298
Net interest income	1,563	1,410
Provision for loan losses	270	159
Other income	436	495
Other expense	735	713
Income before income tax expense	994	1,033
Payment Services [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	0	0
Interest expense	0	0
Net interest income	0	0
Provision for loan losses	2	0
Other income	79	87
Other expense	49	40
Income before income tax expense	28	47
Credit Card Receivable [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	1,537	1,451
Provision for loan losses	230	127
Credit Card Receivable [Member] | Direct Banking [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	1,537	1,451
Credit Card Receivable [Member] | Payment Services [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	0	0
Private Student Loans [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	73	58
Private Student Loans [Member] | Direct Banking [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	73	58
Private Student Loans [Member] | Payment Services [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	0	0
PCI Student Loans [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	68	70
PCI Student Loans [Member] | Direct Banking [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	68	70
PCI Student Loans [Member] | Payment Services [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	0	0
Personal Loans [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	132	103
Personal Loans [Member] | Direct Banking [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	132	103
Personal Loans [Member] | Payment Services [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	0	0
Other [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	23	26
Other [Member] | Direct Banking [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	23	26
Other [Member] | Payment Services [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	$0	$0