Discover Financial Services (DFS) 10-K 25 Feb 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document (USD $)	12 Months Ended
	Dec. 31, 2013	Feb. 14, 2014	Jun. 30, 2013
Document Information [Line Items]	'	'	'
Document type	'10-K	'	'
Amendment flag	'false	'	'
Document period end date	31-Dec-13	'	'
Document fiscal year focus	'2013	'	'
Document fiscal period focus	'FY	'	'
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	'	470,895,643	'
Entity well-known seasoned issuer	'Yes	'	'
Entity voluntary filers	'No	'	'
Entity current reporting status	'Yes	'	'
Entity public float	'	'	$22,996,337,070

Consolidated_Statements_of_Fin

Consolidated Statements of Financial Condition (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Assets	'		'
Cash and cash equivalents	$6,554		$2,584
Restricted cash	182		290
Investment securities:	'		'
Available-for-sale (amortized cost of $4,900 and $6,031 at December 31, 2013 and December 31, 2012, respectively)	4,931	[1]	6,145	[1]
Held-to-maturity (fair value of $58 and $89 at December 31, 2013 and December 31, 2012, respectively)	60	[2]	87	[2]
Total investment securities	4,991		6,232
Loan receivables:	'		'
Mortgage loans held for sale, measured at fair value	148	[3]	355	[3]
Loan portfolio:	'		'
Credit card	53,150		51,135
Other	8,295		6,406
Purchased credit-impaired loans	4,178		4,702
Total loan portfolio	65,623		62,243
Total loan receivables	65,771		62,598
Allowance for loan losses	-1,648		-1,788
Net loan receivables	64,123		60,810
Premises and equipment, net	654		538
Goodwill	284		286
Intangible assets, net	185		189
Other assets	2,367		2,562
Total assets	79,340		73,491
Deposits:	'		'
Interest-bearing deposit accounts	44,766		42,077
Non-interest bearing deposit accounts	193		136
Total deposits	44,959		42,213
Short-term borrowings	140		327
Long-term borrowings	20,474		17,666
Accrued expenses and other liabilities	2,958		3,412
Total liabilities	68,531		63,618
Commitments, contingencies and guarantees (Notes 16, 19, and 20)	'		'
Stockholders’ Equity:	'		'
Common stock, par value $0.01 per share; 2,000,000,000 shares authorized; 555,349,629 and 553,350,975 shares issued at December 31, 2013 and December 31, 2012, 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 December 31, 2013 and December 31, 2012, respectively	560		560
Additional paid-in capital	3,687		3,598
Retained earnings	9,611		7,472
Accumulated other comprehensive loss	-68		-72
Treasury stock, at cost; 83,105,578 and 55,489,104 shares at December 31, 2013 and December 31, 2012, respectively	-2,986		-1,690
Total stockholders’ equity	10,809		9,873
Total liabilities and stockholders’ equity	79,340		73,491
Variable Interest Entity, Primary Beneficiary [Member]	'		'
Assets	'		'
Restricted cash	179		280
Loan portfolio:	'		'
Allowance for loan losses	-861		-1,110
Other assets	34		29
Deposits:	'		'
Long-term borrowings	16,986		15,933
Accrued expenses and other liabilities	9		11
Variable Interest Entity, Primary Beneficiary [Member] | Credit Card Securitization Trusts [Member]	'		'
Assets	'		'
Restricted cash	90		184
Loan portfolio:	'		'
Credit card	31,112	[4]	34,782	[4]
Allowance for loan losses	-833	[4]	-1,110	[4]
Other assets	34		29
Variable Interest Entity, Primary Beneficiary [Member] | Student Loan Securitization Trusts [Member]	'		'
Assets	'		'
Restricted cash	89		96
Loan portfolio:	'		'
Purchased credit-impaired loans	2,248		2,539
Allowance for loan losses	($28)	[4]	$0	[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.

Consolidated_Statements_of_Fin1

Consolidated Statements of Financial Condition (Parenthetical) (USD $)	Dec. 31, 2013		Dec. 31, 2012
Statement of Financial Position [Abstract]	'		'
Available-for-sale investment securities, amortized cost (in dollars)	$4,900,000,000	[1]	$6,031,000,000	[1]
Held-to-maturity investment securities, fair value (in dollars)	58,000,000	[2]	89,000,000	[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	555,349,629		553,350,975
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	83,105,578		55,489,104
[1]	Available-for-sale investment securities are reported at fair value.
[2]	Held-to-maturity investment securities are reported at amortized cost.

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	1 Months Ended	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Interest income:	'	'	'	'
Credit card loans	$510	$5,978	$5,751	$5,654
Other loans	78	997	856	619
Investment securities	7	74	80	59
Other interest income	0	15	16	13
Total interest income	595	7,064	6,703	6,345
Interest expense:	'	'	'	'
Deposits	65	698	845	987
Short-term borrowings	0	3	1	0
Long-term borrowings	38	445	485	498
Total interest expense	103	1,146	1,331	1,485
Net interest income	492	5,918	5,372	4,860
Provision for loan losses	178	1,086	848	1,013
Net interest income after provision for loan losses	314	4,832	4,524	3,847
Other income:	'	'	'	'
Discount and interchange revenue, net	82	1,126	1,035	1,084
Protection products revenue	33	350	409	428
Loan fee income	29	320	325	338
Transaction processing revenue	18	192	218	180
Gain (loss) on investments	2	5	26	-4
Gain on origination and sale of mortgage loans	17	144	105	0
Other income	19	169	163	179
Total other income	200	2,306	2,281	2,205
Other expense:	'	'	'	'
Employee compensation and benefits	87	1,164	1,048	914
Marketing and business development	51	717	603	537
Information processing and communications	25	333	289	264
Professional fees	34	410	432	415
Premises and equipment	8	82	76	71
Other expense	35	488	604	340
Total other expense	240	3,194	3,052	2,541
Income before income tax expense	274	3,944	3,753	3,511
Income tax expense	104	1,474	1,408	1,284
Net income	170	2,470	2,345	2,227
Net income allocated to common stockholders	$168	$2,414	$2,318	$2,202
Basic earnings per common share (in dollars per share)	$0.34	$4.97	$4.47	$4.06
Diluted earnings per common share (in dollars per share)	$0.34	$4.96	$4.46	$4.06

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	1 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2013		Nov. 30, 2012		Nov. 30, 2011
Net income	$170		$2,470		$2,345		$2,227
Other comprehensive income (loss), net of taxes	'		'		'		'
Unrealized (loss) gain on available-for-sale investment securities, net of tax	-3		-52		19		47
Unrealized gain (loss) on cash flow hedges, net of tax	0		10		-4		5
Unrealized pension and post-retirement plan gain (loss), net of tax	6		45		-38		-21
Foreign currency translation adjustments, net of tax	0		1		0		0
Other comprehensive income (loss)	3	[1]	4	[1]	-23	[1]	31	[1]
Comprehensive income	$173		$2,474		$2,322		$2,258
[1]	In February 2013, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. ASU 2013-02 requires an entity to report the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in the consolidated statements of income if the amount being reclassified is required to be reclassified in its entirety to net income. For amounts that are not required to be reclassified to net income in their entirety in the same reporting period, an entity is required to cross-reference other disclosures that provide additional detail about those amounts. As the result, the Company has adjusted its AOCI presentation prospectively, as required, and therefore additional table was included to present the required information for the current period and the presentation has changed from historical periods.

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Stockholders' Equity (USD $)	Total		Preferred Stock [Member]	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 Nov. 30, 2010	$6,457		$0	$5	$3,435	$3,126	($83)	($26)	'	'	'
Preferred stock, shares outstanding, balance at beginning of period (in shares) at Nov. 30, 2010	'		0	'	'	'	'	'	'	'	'
Common stock, shares outstanding, balance at beginning of period (in shares) at Nov. 30, 2010	'		'	547,128,000	'	'	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'		'	'	'	'	'	'	'	'	'
Net income	2,227		'	'	'	2,227	'	'	'	'	'
Other comprehensive income (loss)	31	[1]	'	'	'	'	31	'	'	'	'
Purchases of treasury stock	-436		'	'	'	'	'	-436	'	'	'
Common stock issued under employee benefit plans (in shares)	'		'	54,000	'	'	'	'	'	'	'
Common stock issued under employee benefit plans	1		'	0	1	'	'	'	'	'	'
Common stock issued and stock-based compensation expense (in shares)	'		'	2,567,000	'	'	'	'	'	'	'
Common stock issued and stock-based compensation expense	72		'	0	72	'	'	'	'	'	'
Dividends declared, common stock	-110		'	'	'	-110	'	'	'	'	'
Dividends declared, Series B preferred stock	0		'	'	'	'	'	'	'	'	'
Dividends declared per common share, $0.20 in the fiscal year ended November 30, 2011, $0.40 in the fiscal year ended November 30, 2012, $0.14 in the one month ended December 31, 2012, $0.60 in the calendar year ended December 31, 2013 (in dollars per share)	$0.20		'	'	'	'	'	'	'	'	'
Dividends declared per preferred share, Series B preferred stock, $8.13 in the fiscal year ended November 30, 2012, $65.00 in the calendar year ended December 31, 2013 (in dollars per share)	$0		'	'	'	'	'	'	'	'	'
Stockholders' equity, balance at end of period at Nov. 30, 2011	8,242		0	5	3,508	5,243	-52	-462	'	'	'
Preferred stock, shares outstanding, balance at end of period (in shares) at Nov. 30, 2011	'		0	'	'	'	'	'	'	'	'
Common stock, shares outstanding, balance at end of period (in shares) at Nov. 30, 2011	'		'	549,749,000	'	'	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'		'	'	'	'	'	'	'	'	'
Net income	2,345		'	'	'	2,345	'	'	'	'	'
Other comprehensive income (loss)	-23	[1]	'	'	'	'	-23	'	'	'	'
Purchases of treasury stock	-1,216		'	'	'	'	'	-1,216	'	'	'
Common stock issued under employee benefit plans (in shares)	'		'	54,000	'	'	'	'	'	'	'
Common stock issued under employee benefit plans	2		'	0	2	'	'	'	'	'	'
Common stock issued and stock-based compensation expense (in shares)	'		'	3,246,000	'	'	'	'	'	'	'
Common stock issued and stock-based compensation expense	83		'	0	83	'	'	'	'	'	'
Dividends declared, common stock	-210		'	'	'	-210	'	'	'	'	'
Dividends declared, Series B preferred stock	-5		'	'	'	'	'	'	'	'	-5
Issuance of Series B preferred stock, net of issuance costs (in shares)	'		'	'	'	'	'	'	'	575,000	'
Issuance of Series B preferred stock, net of issuance costs	560		'	'	'	'	'	'	'	560	'
Dividends declared per common share, $0.20 in the fiscal year ended November 30, 2011, $0.40 in the fiscal year ended November 30, 2012, $0.14 in the one month ended December 31, 2012, $0.60 in the calendar year ended December 31, 2013 (in dollars per share)	$0.40		'	'	'	'	'	'	'	'	'
Dividends declared per preferred share, Series B preferred stock, $8.13 in the fiscal year ended November 30, 2012, $65.00 in the calendar year ended December 31, 2013 (in dollars per share)	$8.13		'	'	'	'	'	'	'	'	'
Stockholders' equity, balance at end of period at Nov. 30, 2012	9,778		'	5	3,593	7,373	-75	-1,678	'	560	'
Preferred stock, shares outstanding, balance at end of period (in shares) at Nov. 30, 2012	'		'	'	'	'	'	'	'	575,000	'
Common stock, shares outstanding, balance at end of period (in shares) at Nov. 30, 2012	'		'	553,049,000	'	'	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'		'	'	'	'	'	'	'	'	'
Net income	170		'	'	'	170	'	'	'	'	'
Other comprehensive income (loss)	3	[1]	'	'	'	'	3	'	'	'	'
Purchases of treasury stock	-12		'	'	'	'	'	-12	'	'	'
Common stock issued and stock-based compensation expense (in shares)	'		'	302,000	'	'	'	'	'	'	'
Common stock issued and stock-based compensation expense	5		'	0	5	'	'	'	'	'	'
Dividends declared, common stock	-71		'	'	'	-71	'	'	'	'	'
Dividends declared, Series B preferred stock	0		'	'	'	'	'	'	'	'	'
Dividends declared per common share, $0.20 in the fiscal year ended November 30, 2011, $0.40 in the fiscal year ended November 30, 2012, $0.14 in the one month ended December 31, 2012, $0.60 in the calendar year ended December 31, 2013 (in dollars per share)	$0.14		'	'	'	'	'	'	'	'	'
Dividends declared per preferred share, Series B preferred stock, $8.13 in the fiscal year ended November 30, 2012, $65.00 in the calendar year ended December 31, 2013 (in dollars per share)	$0		'	'	'	'	'	'	'	'	'
Stockholders' equity, balance at end of period at Dec. 31, 2012	9,873		'	5	3,598	7,472	-72	-1,690	'	560	'
Preferred stock, shares outstanding, balance at end of period (in shares) at Dec. 31, 2012	575,000		'	'	'	'	'	'	'	575,000	'
Common stock, shares outstanding, balance at end of period (in shares) at Dec. 31, 2012	'		'	553,351,000	'	'	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'		'	'	'	'	'	'	'	'	'
Net income	2,470		'	'	'	2,470	'	'	'	'	'
Other comprehensive income (loss)	4	[1]	'	'	'	'	4	'	'	'	'
Purchases of treasury stock	-1,296		'	'	'	'	'	-1,296	'	'	'
Common stock issued under employee benefit plans (in shares)	'		'	66,000	'	'	'	'	'	'	'
Common stock issued under employee benefit plans	3		'	0	3	'	'	'	'	'	'
Common stock issued and stock-based compensation expense (in shares)	'		'	1,933,000	'	'	'	'	'	'	'
Common stock issued and stock-based compensation expense	86		'	0	86	'	'	'	'	'	'
Dividends declared, common stock	-294		'	'	'	-294	'	'	'	'	'
Dividends declared, Series B preferred stock	-37		'	'	'	'	'	'	-37	'	-37
Dividends declared per common share, $0.20 in the fiscal year ended November 30, 2011, $0.40 in the fiscal year ended November 30, 2012, $0.14 in the one month ended December 31, 2012, $0.60 in the calendar year ended December 31, 2013 (in dollars per share)	$0.60		'	'	'	'	'	'	'	'	'
Dividends declared per preferred share, Series B preferred stock, $8.13 in the fiscal year ended November 30, 2012, $65.00 in the calendar year ended December 31, 2013 (in dollars per share)	$65		'	'	'	'	'	'	'	'	'
Stockholders' equity, balance at end of period at Dec. 31, 2013	$10,809		'	$5	$3,687	$9,611	($68)	($2,986)	'	$560	'
Preferred stock, shares outstanding, balance at end of period (in shares) at Dec. 31, 2013	575,000		'	'	'	'	'	'	'	575,000	'
Common stock, shares outstanding, balance at end of period (in shares) at Dec. 31, 2013	'		'	555,350,000	'	'	'	'	'	'	'
[1]	In February 2013, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. ASU 2013-02 requires an entity to report the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in the consolidated statements of income if the amount being reclassified is required to be reclassified in its entirety to net income. For amounts that are not required to be reclassified to net income in their entirety in the same reporting period, an entity is required to cross-reference other disclosures that provide additional detail about those amounts. As the result, the Company has adjusted its AOCI presentation prospectively, as required, and therefore additional table was included to present the required information for the current period and the presentation has changed from historical periods.

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Cash flows from operating activities	'	'	'	'
Net income	$170	$2,470	$2,345	$2,227
Adjustments to reconcile net income to net cash provided by operating activities:	'	'	'	'
Provision for loan losses	178	1,086	848	1,013
Deferred income taxes	-12	322	146	232
Depreciation and amortization on premises and equipment	9	111	95	90
Amortization of deferred revenues	-16	-193	-204	-255
Other depreciation and amortization	15	223	172	156
Accretion of accretable yield on acquired loans	-24	-272	-303	-225
(Gain) loss on investments	-2	-5	-26	4
Loss on equity method and other investments	1	18	11	5
Loss on premises and equipment	0	8	0	3
Gain on origination and sale of loans	-17	-144	-104	-5
Stock-based compensation expense	3	59	47	44
Gain on purchase of business	0	0	0	-7
Proceeds from sale of mortgage loans originated for sale	378	4,160	1,798	0
Net principal disbursed on mortgage loans originated for sale	-392	-3,805	-2,021	0
Changes in assets and liabilities:	'	'	'	'
Increase in other assets	-68	-252	-112	-22
(Decrease) increase in accrued expenses and other liabilities	-1	-269	349	338
Net cash provided by operating activities	222	3,517	3,041	3,598
Cash flows from investing activities	'	'	'	'
Maturities of other short-term investments	0	0	0	375
Maturities and sales of available-for-sale investment securities	112	1,423	1,783	1,327
Purchases of available-for-sale investment securities	-132	-325	-1,816	-2,400
Maturities of held-to-maturity investment securities	1	29	11	18
Purchases of held-to-maturity investment securities	0	-2	-51	-2
Proceeds from sale of student loans held for sale	0	0	269	29
Net principal disbursed on loans originated for investment	-1,599	-3,915	-4,085	-3,958
Purchases of loan receivables	-27	-136	-490	-3,165
Purchase of net assets of a business	0	0	-49	0
Purchase of business, net of cash acquired	0	0	0	-401
Purchases of other investments	-4	-114	-65	-109
Proceeds from sale of other investments	17	0	0	0
Decrease (increase) in restricted cash	2,054	108	-1,057	284
Proceeds from sale of premises and equipment	0	0	1	3
Purchases of premises and equipment	-13	-231	-144	-111
Net cash (used for) provided by investing activities	409	-3,163	-5,693	-8,110
Cash flows from financing activities	'	'	'	'
Net (decrease) increase in short-term borrowings	43	-231	234	50
Proceeds from issuance of securitized debt	0	4,650	5,850	3,700
Maturities and repayment of securitized debt	-2,066	-3,638	-3,752	-5,744
Proceeds from issuance of other long-term borrowings	0	1,744	0	0
Repayment of long-term borrowings and bank notes	0	0	-13	-362
Payment of contingent consideration for purchase of net assets of a business, at fair value	0	-9	0	0
Premium paid on debt exchange	0	0	-291	0
Proceeds from issuance of common stock	2	13	26	23
Purchases of treasury stock	-12	-1,296	-1,216	-436
Net increase in deposits	65	2,782	2,539	5,142
Proceeds from issuance of preferred stock	0	0	560	0
Dividends paid on common and preferred stock	-5	-399	-209	-110
Net cash provided by (used for) financing activities	-1,973	3,616	3,728	2,263
Net increase (decrease) in cash and cash equivalents	-1,342	3,970	1,076	-2,249
Cash and cash equivalents, at beginning of period	3,926	2,584	2,850	5,099
Cash and cash equivalents, at end of period	2,584	6,554	3,926	2,850
Cash paid during the period for:	'	'	'	'
Interest expense	81	975	1,203	1,342
Income taxes, net of income tax refunds	-1	1,348	1,301	906
Non-cash investing and financing transactions:	'	'	'	'
Initial fair value of contingent consideration paid for purchase of net assets of a business	0	0	8	0
Assumption of debt by buyer related to loans sold	0	0	425	0
Assumption of SLC debt	$0	$0	$0	$2,921

Background_and_Basis_of_Presen

Background and Basis of Presentation	12 Months Ended
	Dec. 31, 2013
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.
	Change in Fiscal Year End
	On December 3, 2012, the Company's board of directors approved a change in the Company’s fiscal year end from November 30 to December 31 of each year. This fiscal year change was effective January 1, 2013. As a result of the change, the Company had a one month transition period in December 2012. The audited results for the one month ended December 31, 2012 and the unaudited results for the one month ended December 31, 2011 are included in this report in Note 26: Transition Period Financial Information.
	Basis of Presentation
	The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The preparation of financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and related disclosures. These estimates are based on information available as of the date of the consolidated financial statements. The Company believes that the estimates used in the preparation of the consolidated financial statements are reasonable. Actual results could differ from these estimates. Beginning with the 2012 Form 10-K, the Company began reporting all dollar amounts in millions. In certain circumstances, this change in rounding resulted in prior year disclosures being removed. Certain prior period amounts have been reclassified to conform to current period presentation.
	Principles of Consolidation
	The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. The Company's policy is to consolidate all entities in which it owns more than 50% of the outstanding voting stock unless it does not control the entity. However, the Company did not have a controlling voting interest in any entity other than its wholly-owned subsidiaries in the periods presented in the accompanying consolidated financial statements.
	It is also the Company's policy to consolidate any variable interest entity for which the Company is the primary beneficiary, as defined by GAAP. On this basis, the Company consolidates the Discover Card Master Trust I and the Discover Card Execution Note Trust as well as three student loan securitization trusts acquired in 2010. The Company is deemed to be the primary beneficiary of each of these trusts since it is, for each, the trust servicer and the holder of both the residual interest and the majority of the most subordinated interests. Because of those involvements, the Company has, for each trust, i) the power to direct the activities that most significantly impact the economic performance of the trust, and ii) the obligation (or right) to absorb losses (or receive benefits) of the trust that could potentially be significant. The Company has determined that it was not the primary beneficiary of any other variable interest entity during the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 or one month ended December 31, 2012.
	For investments in any entities in which the Company owns 50% or less of the outstanding voting stock but in which the Company has significant influence over operating and financial decisions, the Company applies the equity method of accounting. In cases where the Company's equity investment is less than 20% and significant influence does not exist, such investments are carried at cost.
	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.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	Summary of Significant Accounting Policies
	Cash and Cash Equivalents
	Cash and cash equivalents is defined by the Company as cash on deposit with banks, including time deposits and other highly liquid investments, with maturities of 90 days or less when purchased. Cash and cash equivalents included $719 million and $797 million of cash and due from banks and $5.8 billion and $1.8 billion of interest-earning deposits in other banks at December 31, 2013 and 2012, respectively.
	Restricted Cash
	Restricted cash includes cash for which the Company's ability to withdraw funds at any time is contractually limited. Restricted cash is generally designated for specific purposes arising out of certain contractual or other obligations.
	Investment Securities
	At December 31, 2013, investment securities consisted of U.S. Treasury and U.S. government agency obligations, mortgage-backed securities issued by government agencies, debt instruments issued by states and political subdivisions of states and credit card asset-backed securities issued by other institutions. Investment securities that the Company has the positive intent and ability to hold to maturity are classified as held-to-maturity and are reported at amortized cost. All other investment securities are classified as available-for-sale, as the Company does not hold investment securities for trading purposes. Available-for-sale investment securities are reported at fair value with unrealized gains and losses, net of tax, reported as a component of accumulated other comprehensive income included in stockholders' equity. The Company estimates the fair value of available-for-sale investment securities pursuant to the guidance in ASC Topic 820, Fair Value Measurements and Disclosures (“ASC 820”) as more fully discussed in Note 21: Fair Value Measurements and Disclosures. The amortized cost for each held-to-maturity and available-for-sale investment security is adjusted for amortization of premiums or accretion of discounts, as appropriate. Such amortization or accretion is included in interest income. The Company evaluates its unrealized loss positions for other-than-temporary impairment in accordance with GAAP applicable for investments in debt and equity securities. Realized gains and losses and other-than-temporary impairments related to investment securities are determined at the individual security level and are reported in other income.
	Mortgage Loans Held for Sale
	Mortgage loans held for sale consist of residential first mortgage loans that are secured by residential real estate throughout the United States. The Company originates all of its residential real estate loans with the intent to sell them in the secondary market on a servicing-released basis and classifies them as held for sale at the time of origination. The Company includes mortgage loans held for sale in total loan receivables and carries these assets at fair value pursuant to an optional fair value measurement election. Changes in fair value are recorded through revenue 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 "— Financial Instruments Used for Asset and Liability Management" and Note 22: Derivatives and Hedging Activities for further discussion of mortgage-related hedging activities and see Note 21: Fair Value Measurements and Disclosures for further discussion on estimating fair value for mortgage loans held for sale). The Company recognizes interest income on these loans separately from changes in their fair value.
	Loan Receivables
	Loan receivables consist of credit card receivables and other loans and include purchased credit-impaired ("PCI") loans as well as loans held for sale. Loan receivables also include unamortized net deferred loan origination fees and costs (also see “— Loan Interest and Fee Income”). Credit card loan receivables include consumer credit card loan receivables and business credit card loan receivables. Credit card loan receivables are reported at their principal amounts outstanding and include uncollected billed interest and fees and are reduced for unearned revenue related to balance transfer fees (also see “— Loan Interest and Fee Income”). Other loans consist of student loans, personal loans and other loans and are reported at their principal amounts outstanding. With the exception of mortgages, the Company's loan receivables are deemed to be held for investment at origination or acquisition because management has the intent and ability to hold them for the foreseeable future.
	PCI loans are loans acquired at prices which reflected a discount related to deterioration in individual loan credit quality since origination. The Company's PCI loans are comprised entirely of private student loans acquired during the 2011 fiscal year. These loans are accounted for pursuant to ASC Subtopic 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality.
	The PCI student loans were aggregated into pools based on common risk characteristics at the time of their acquisition. Loans were grouped primarily on the basis of origination date as loans originated in a particular year generally reflect the application of common origination strategies and/or underwriting criteria. Each pool is accounted for as a single asset and each has a single composite interest rate, total contractual cash flows and total expected cash flows.
	Interest income on PCI loans is recognized on the basis of expected cash flows rather than contractual cash flows. The total amount of interest income recognizable on a pool of PCI loans (i.e., its accretable yield) is the difference between the carrying amount of the loan pool and the future cash flows expected to be collected without regard to whether the expected cash flows represent principal or interest collections. Interest is recognized on an effective yield basis over the life of the loan pool.
	The initial estimates of the fair value of the PCI student loans included the impact of expected credit losses, and therefore, no allowance for loan loss was recorded as of the purchase dates. The difference between contractually required cash flows and cash flows expected to be collected, as measured at the acquisition dates, is not permitted to be accreted. Charge-offs are absorbed by this non-accretable difference and do not result in a charge to earnings.
	The estimate of cash flows expected to be collected is evaluated each reporting period to ensure it reflects management's latest expectations of future credit losses and borrower prepayments, and interest rates in effect in the current period. To the extent expected credit losses increase after the acquisition dates, the Company will record an allowance for loan losses through the provision for loan losses, which will reduce net income. Changes in expected cash flows related to changes in prepayments or interest rate indices for variable rate loans generally are recorded prospectively as adjustments to interest income.
	To the extent that a significant increase in cash flows due to lower expected losses is deemed probable, the Company will first reverse any previously established allowance for loan losses and then increase the amount of remaining accretable yield. The increase to yield would be recognized prospectively over the remaining life of the loan pool. An increase in the accretable yield would reduce the remaining non-accretable difference available to absorb subsequent charge-offs. Disposals of loans, which may include sales of loans or receipt of payments in full from the borrower or charge-offs, result in removal of the loans from their respective pools.
	Cash flows associated with loans that are originated or acquired with the intent to sell are included in cash flows from operating activities. Cash flows associated with loans originated or acquired for investment are classified as cash flows from investing activities, regardless of a subsequent change in intent.
	Delinquent Loans
	The entire balance of an account is contractually past due if the minimum payment is not received by the specified date on the customer's billing statement. Delinquency is reported on loans that are 30 days or more past due.
	Credit card loans are charged off at the end of the month during which an account becomes 180 days past due. Closed-end consumer loan receivables are charged off at the end of the month during which an account becomes 120 days contractually past due. 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 time frame described above. Receivables associated with alleged or potential fraudulent transactions are adjusted to their net realizable value upon receipt of notification of such fraud through a charge to other expense and are subsequently written off at the end of the month 90 days following notification, but not later than the contractual 180-day or 120-day time frame described above. The Company's charge-off policies are designed to comply with guidelines established by the Federal Financial Institutions Examination Council (“FFIEC”).
	The practice of re-aging an account also may affect loan delinquencies and charge-offs. A re-age is intended to assist delinquent customers who have experienced financial difficulties but who demonstrate both an ability and willingness to repay. Accounts meeting specific criteria are re-aged when the Company and the customer agree on a temporary repayment schedule that may include concessionary terms. With re-aging, the outstanding balance of a delinquent account is returned to a current status. Customers may also qualify for a workout re-age when either a longer term or permanent hardship exists. The Company's re-age practices are designed to comply with FFIEC guidelines.
	Allowance for Loan Losses
	The Company maintains an allowance for loan losses at a level that is appropriate to absorb probable losses inherent in the loan portfolio. The estimate of probable incurred losses considers uncollectible principal, interest and fees reflected in the loan receivables. The allowance is evaluated monthly for appropriateness 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.
	The Company calculates its allowance for loan losses by estimating probable losses separately for classes of the loan portfolio with similar loan characteristics, which generally results in segmenting the portfolio by loan product type.
	For its credit card loan receivables, the Company bases its allowance for loan loss 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 does not evaluate credit card loans for impairment on an individual basis, but instead estimates its allowance for credit card loan losses on a pooled basis, which includes loans that are delinquent and/or no longer accruing interest.
	For its other loans, the Company considers historical and forecasted estimates of incurred losses in estimating the related allowance for loan losses. The Company also considers other factors, such as current economic conditions, recent trends in delinquencies and bankruptcy filings, account collection management, policy changes, account seasoning, loan volume and amounts, payment rates and forecasting uncertainties. Similar to credit card loans, the Company estimates its allowance for personal and student loan losses on a pooled basis, which includes loans that are delinquent and/or no longer accruing interest.
	As part of certain collection strategies, the Company may modify the terms of loans to customers experiencing financial hardship. Temporary and permanent modifications on credit card loans, certain grants of student loan forbearance and certain short and long-term modifications to personal loans are considered troubled debt restructurings and are accounted for in accordance with ASC Subtopic 310-40, Troubled Debt Restructuring by Creditors. With respect to student loans, the Company does not anticipate significant shortfalls in collections on the contractual amounts due from 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.
	Loan receivables, other than PCI loans, that have been modified under a troubled debt restructuring are evaluated separately from the pools of receivables that are subject to the collective analyses described above. Loan receivables modified in a troubled debt restructuring are recorded at their present values with impairment measured as the difference between the loan balance and the discounted present value of cash flows expected to be collected. Changes in the present value are recorded in the provision for loan losses. All of the Company's troubled debt restructurings, which are evaluated collectively on an aggregated (by loan type) basis, have a related allowance for loan losses.
	Premises and Equipment, net
	Premises and equipment, net, are stated at cost less accumulated depreciation and amortization, which is computed using the straight-line method over the estimated useful lives of the assets. Buildings are depreciated over a period of 39 years. The costs of leasehold improvements are capitalized and depreciated over the lesser of the remaining term of the lease or the asset's estimated useful life, typically ten years. Furniture and fixtures are depreciated over a period of five to ten years. Equipment is depreciated over three to ten years. Capitalized leases, consisting of computers and processing equipment, are depreciated over three and six years, respectively. Maintenance and repairs are immediately expensed, while the costs of improvements are capitalized.
	Purchased software and capitalized costs related to internally developed software are amortized over their useful lives of three to ten years. Costs incurred during the application development stage related to internally developed software are capitalized in accordance with ASC Subtopic 350-40, Intangibles - Goodwill and Other: Internal Use Software. Pursuant to that guidance, costs are expensed as incurred during the preliminary project stage and post implementation stage. Once the capitalization criteria as defined in GAAP have been met, external direct costs incurred for materials and services used in developing or obtaining internal-use computer software and payroll and payroll-related costs for employees who are directly associated with the internal-use computer software project (to the extent those employees devoted time directly to the project) are capitalized. Amortization of capitalized costs begins when the software is ready for its intended use. Capitalized software is included in premises and equipment, net in the Company's consolidated statements of financial condition. See Note 7: Premises and Equipment for further information about the Company's premises and equipment.
	Goodwill
	Goodwill is recorded as part of the Company's acquisitions of businesses when the purchase price exceeds the fair value of the net tangible and separately identifiable intangible assets acquired. The Company's goodwill is not amortized, but rather is subject to an impairment test at the reporting unit level annually, or between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount, pursuant to ASC Topic 350, Intangibles - Goodwill and Other. The Company's reported goodwill relates to PULSE, acquired in 2005, and to the Home Loan Center mortgage origination business acquired in 2012. The Company's goodwill impairment analysis is a two-step test. In the first step, the fair value of the reporting unit is compared to its carrying value. If the fair value of the reporting unit exceeds its carrying value including goodwill, goodwill is not impaired. If the carrying value including goodwill exceeds its fair value, goodwill is potentially impaired and the second step of the test becomes necessary. In the second step, the implied fair value of goodwill is derived and compared to the carrying amount of goodwill. The implied fair value of goodwill is the excess of the fair value of the reporting unit over the sum of the fair values of all identifiable assets less the liabilities associated with the reporting unit. If the carrying value of goodwill allocated to the reporting unit exceeds its implied fair value, an impairment charge is recorded for the excess.
	Historically, the Company’s policy was to perform the annual impairment test of goodwill as of June 1 of each year. The 2013 annual impairment test was conducted in accordance with this policy and identified no impairment. During the fourth quarter of 2013, the Company changed the date of its annual goodwill impairment test to October 1. The change in goodwill impairment testing date is deemed a change in accounting principle which management determined to be preferable under the circumstances. The change was made to better align with the timing of its annual and long-term planning process, which is a significant element in the testing process. Due to the change in the Company’s fiscal year end from November 30 to December 31, the change from June 1 to October 1 also enhances the ability of the Company to obtain carrying values for use in the testing process by using the beginning of a fiscal quarter.
	In connection with the change in date of the annual goodwill impairment test, the Company performed a goodwill impairment test on October 1, 2013, and no impairment charge was identified. This change did not delay, accelerate, or avoid a goodwill impairment charge. The goodwill impairment tests on June 1, 2013 and October 1, 2013 were performed such that a period greater than 12 months did not elapse between test dates. The change in the annual goodwill impairment testing date was applied prospectively beginning on October 1, 2013 and had no effect on the consolidated financial statements. This change was not applied retrospectively as it is impracticable to do so because retrospective application would have required the application of significant estimates and assumptions without the use of hindsight.
	Intangible Assets
	The Company's identifiable intangible assets consist of both amortizable and nonamortizable intangible assets. The Company's amortizable intangible assets consist primarily of acquired customer relationships and certain trade name intangibles. All of the Company's amortizable intangible assets are carried at net book value and are amortized over their estimated useful lives. The amortization periods approximate the periods over which the Company expects to generate future net cash inflows from the use of these assets. The Company's policy is to amortize intangibles in a manner that reflects the pattern in which the projected net cash inflows to the Company are expected to occur, where such pattern can be reasonably determined, as opposed to the straight-line basis. This method of amortization typically results in a greater portion of the intangible asset being amortized in the earlier years of its useful life.
	All of the Company's amortizable intangible assets, as well as other amortizable or depreciable long-lived assets such as premises and equipment, are subject to impairment testing when events or conditions indicate that the carrying value of an asset may not be fully recoverable from future cash flows. A test for recoverability is done by comparing the asset's carrying value to the sum of the undiscounted future net cash inflows expected to be generated from the use of the asset over its remaining useful life. Impairment exists if the sum of the undiscounted expected future net cash inflows is less than the carrying amount of the asset. Impairment would result in a write-down of the asset to its estimated fair value. The estimated fair values of these assets are based on the discounted present value of the stream of future net cash inflows expected to be derived over the remaining useful lives of the assets. If an impairment write-down is recorded, the remaining useful life of the asset will be evaluated to determine whether revision of the remaining amortization or depreciation period is appropriate.
	The Company's nonamortizable intangible assets consist of the international transaction processing rights and brand-related intangibles included in the acquisition of Diners Club as well as the trade names acquired in The Student Loan Corporation acquisition. These assets are deemed to have indefinite useful lives and are therefore not subject to amortization. All of the Company's nonamortizable intangible assets are subject to a test for impairment annually, or more frequently if events or changes in circumstances indicate that the asset might be impaired. As required by GAAP, if the carrying value of a nonamortizable intangible asset is in excess of its fair value, the asset must be written down to its fair value through the recognition of an impairment charge to earnings. In contrast to amortizable intangibles, there is no test for recoverability associated with the impairment test for nonamortizable intangible assets.
	During the fourth quarter of 2013, the Company changed the date of its annual impairment test for nonamortizable intangible assets from June 1 to October 1 to coincide with the change in the Company's goodwill impairment test date. The Company performed impairment tests at June 1, 2013 and October 1, 2013, and as such a period greater than 12 months did not elapse between test dates. No impairment charges were identified during the impairment tests conducted at June 1, 2013 and October 1, 2013.
	Stock-based Compensation
	The Company measures the cost of employee services received in exchange for an award of stock-based compensation based on the grant-date fair value of the award. The cost is recognized over the requisite service period, except for awards granted to retirement-eligible employees, which are fully expensed by the grant date. No compensation cost is recognized for awards that are subsequently forfeited.
	Advertising Costs
	The Company expenses advertising costs as incurred. Television advertising costs are expensed in the period in which the advertising is first aired. Advertising costs are recorded in marketing and business development and were $208 million, $172 million, $150 million and $17 million for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, respectively.
	Income Taxes
	Income tax expense is provided for using the asset and liability method, under which deferred tax assets and liabilities are determined based on the temporary differences between the financial statement and income tax bases of assets and liabilities using currently enacted tax rates. Deferred tax assets are recognized when their realization is determined to be more likely than not, in accordance with the accounting guidance. Uncertain tax positions are measured at the highest amount of tax benefit for which realization is judged to be more likely than not. Tax benefits that do not meet these criteria are unrecognized tax benefits. See Note 16: Income Taxes for more information about the Company's income taxes.
	Financial Instruments Used for Asset and Liability Management
	The Company utilizes derivative financial instruments to manage its various exposures to changes in fair value of certain assets and liabilities, variability in future cash flows arising from changes in interest rates, or other types of forecasted transactions, and changes in foreign exchange rates. All derivatives are carried at their estimated fair values on the Company’s consolidated statements of financial condition. Derivatives having positive net fair values, inclusive of net accrued interest receipts or payments, are recorded in other assets. Derivatives with negative net fair values, inclusive of net accrued interest payments or receipts, are recorded in accrued expenses and other liabilities. The methodologies used to estimate the fair values of these derivative financial instruments are described in Note 21: Fair Value Measurements and Disclosures. Collateral receivable or payable amounts associated with derivatives are not offset against the fair value of these derivatives, but are recorded separately in other assets or deposits, respectively.
	Certain of these instruments are designated and qualify for hedge accounting in accordance ASC Topic 815, Derivatives and Hedging. Under cash flow hedge accounting, the effective portion of the change in the fair value of these derivative instruments is recognized in other comprehensive income. The change in fair value of these derivative instruments relating to the ineffective portion is recognized immediately in other income. Amounts accumulated in other comprehensive income are reclassified to earnings in the period during which the hedged items affect income. For a net investment hedge, the effective portion of changes in the fair value of the derivatives is 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. Under fair value hedge accounting, changes in both (i) the fair values of the derivative instruments and (ii) the fair values of the hedged items relating to the risks being hedged, including net differences, if any (i.e., ineffectiveness), are recorded in interest expense. Certain other derivatives are not designated as hedges and do not qualify for hedge accounting; changes in the fair value of these derivatives are recorded in other income. These transactions are discussed in more detail in Note 22: Derivatives and Hedging Activities.
	Accumulated Other Comprehensive Income
	The Company records unrealized gains and losses on available-for-sale securities, changes in the fair value of cash flow hedges, and certain pension and foreign currency translation adjustments in other comprehensive income ("OCI") on an after-tax basis where applicable. Details of other comprehensive income, net of tax, are presented in the statement of comprehensive income, and a rollforward of accumulated other comprehensive income ("AOCI") is presented in the statement of changes in stockholders' equity and Note 14: Accumulated Other Comprehensive Income.
	Significant Revenue Recognition Accounting Policies
	Loan Interest and Fee Income
	Interest on loans is comprised largely of interest on credit card loans and is recognized based upon the amount of loans outstanding and their contractual interest rate. Interest on credit card loans is included in loan receivables when billed to the customer. The Company accrues unbilled interest revenue each month from a customer's billing cycle date to the end of the month. The Company applies an estimate of the percentage of loans that will revolve in the next cycle in the estimation of the accrued unbilled portion of interest revenue that is included in accrued interest receivable on the consolidated statements of financial condition. Interest on other loan receivables is accrued monthly in accordance with their contractual terms and recorded in accrued interest receivable, which is included in other assets, in the consolidated statements of financial condition. Interest related to purchased credit-impaired loans is discussed in Note 5: Loan Receivables.
	The Company recognizes fees (except annual fees, balance transfer fees and certain product fees) on loan receivables in interest income or loan fee income as the fees are assessed. Annual fees, balance transfer fees and certain product fees are recognized in interest income or loan fee income ratably over the periods to which they relate. Balance transfer fees are accreted to interest income over the life of the related balance. As of December 31, 2013 and 2012, deferred revenues related to balance transfer fees, recorded as a reduction of loan receivables, were $37 million and $34 million, respectively. Loan fee income consists of fees on credit card loans and includes annual, late, returned check, cash advance and other miscellaneous fees and is reflected net of waivers and charge-offs.
	Pursuant to ASC Subtopic 310-20, Receivables - Nonrefundable Fees and Other Costs, direct loan origination costs on credit card loans are deferred and amortized on a straight-line basis over a one-year period and recorded in interest income from credit card loans. Direct loan origination costs on other loan receivables are deferred and amortized over the life of the loan using the interest method and is recorded in interest income from other loans. As of December 31, 2013 and 2012, the remaining unamortized deferred costs related to loan origination were $43 million and $29 million, respectively, and were recorded in loan receivables.
	The Company accrues interest and fees on loan receivables until the loans are paid or charged off, except in instances of customer bankruptcy, death or fraud, where no further interest and fee accruals occur following notification. Payments received on nonaccrual loans are allocated according to the same payment hierarchy methodology applied to loans that are accruing interest. When loan receivables are charged off, unpaid accrued interest and fees are reversed against the income line items in which they were originally recorded in the consolidated statements of income. Charge-offs and recoveries of amounts which relate to capitalized interest on student loans are treated as principal charge-offs and recoveries, affecting the provision for loan losses rather than interest income. The Company considers uncollectible interest and fee revenues in assessing the adequacy of the allowance for loan losses.
	Discount and Interchange Revenue
	The Company earns discount revenue from fees charged to merchants with whom the Company has entered into card acceptance agreements for processing credit card purchase transactions. We earn acquirer interchange revenue from merchant acquirers on all Discover Network, Diners Club and PULSE transactions made by credit and debit cardholders at merchants with whom merchant acquirers have entered into card acceptance agreements for processing payment card transactions. The Company pays issuer interchange to network partners who have entered into contractual arrangements to issue cards on the Company's networks as compensation for risk and other operating costs. The discount revenue or acquirer interchange is recognized as revenue, net of any associated issuer interchange cost, at the time the transaction is captured.
	Customer Rewards
	The Company offers its customers various reward programs, including the Cashback Bonus reward program, pursuant to which the Company pays certain customers a reward equal to a percentage of their credit card purchase amounts based on the type and volume of the customer's purchases. The liability for customer rewards, which is included in accrued expenses and other liabilities on the consolidated statements of financial condition, is estimated on an individual customer basis and is accumulated as qualified customers make progress toward earning the reward through their ongoing credit card purchase activity or other defined actions. In determining the appropriate liability for customer rewards, the Company estimates forfeitures of rewards accumulated but not redeemed based on historical account closure and charge-off experience, actual customer credit card purchase activity and the terms of the rewards program. In accordance with ASC Subtopic 605-50, Revenue Recognition: Customer Payments and Incentives (“ASC 605-50”), the Company recognizes customer rewards costs as a reduction of the related revenue, if any. In instances where a reward is not associated with a revenue-generating transaction, such as when a reward is given for opening an account, the reward cost is recorded as an operating expense. For the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, rewards costs, adjusted for estimated forfeitures, amounted to $1.0 billion, $1.0 billion, $879 million and $123 million, respectively. At both December 31, 2013 and 2012, the liability for customer rewards, adjusted for estimated forfeitures, was $1.1 billion, which is included in accrued expenses and other liabilities on the consolidated statements of financial condition.
	Protection Products
The Company earns revenue related to fees received for marketing products or services that are ancillary to the Company's credit card and personal loans, including payment protection products and identity theft protection services, to the Company's customers. The amount of revenue recorded is based on the terms of the agreements and contracts with the third parties that provide these services. The Company recognizes this income over the customer agreement or contract period as earned.
Transaction Processing Revenue
Transaction processing revenue represents fees charged to financial institutions and merchant acquirers/processors for processing ATM and debit point-of-sale transactions over the PULSE network and is recognized at the time the transactions are processed. Transaction processing revenue also includes network participant revenue earned by PULSE related to fees charged for maintenance, support, information processing and other services provided to financial institutions, processors and other participants in the PULSE network. These revenues are recognized in the period that the related transactions occur or services are rendered.
Royalty and Licensee Revenue
The Company earns revenue from licensing fees for granting the right to use the Diners Club brand and processing fees for providing various services to Diners Club licensees, which are referred to together as royalty and licensee revenue. Royalty revenue is recognized in the period that the cardholder volume used to calculate the royalty fee is generated. Processing fees are recognized in the month that the services are provided. Royalty and licensee revenue is included in other income on the consolidated statements of income.
Incentive Payments
The Company makes certain incentive payments under contractual arrangements with financial institutions, Diners Club licensees, merchants, acquirers and certain other customers. In accordance with ASC 605-50, these payments are generally classified as contra-revenue unless a specifically identifiable benefit is received by the Company in consideration for the payment and the fair value of such benefit is reasonably estimable and measurable. If no such benefit is identified, then the entire payment is classified as contra-revenue, and included in other income in the consolidated statements of income in the line item where the related revenues are recorded. If the payment gives rise to an asset because it is expected to directly or indirectly contribute to future net cash inflows, it is deferred and recognized over the expected benefit period. The unamortized portion of the deferred incentive payments included in other assets on the consolidated statements of financial condition was $23 million and $41 million at December 31, 2013 and 2012, respectively.

Business_Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Business Combinations	'
	Business Combinations
	Acquisition of Diners Club Italia S.r.l. ("Diners Club Italy") and Dinit d.o.o. ("Dinit")
	On May 21, 2013, through its Discover Financial Services (UK) Limited subsidiary, the Company acquired Diners Club Italy and its wholly-owned subsidiary Dinit to support business operations and the Company's global payments strategy. The cash consideration paid for the acquisition was one euro. Subsequent to the purchase, a capital infusion of approximately €45 million (approximately $58 million) was executed primarily to settle outstanding debt. The primary assets acquired as part of the purchase were charge card receivables of approximately $34 million, which were recorded in the Payment Services segment. Since the acquisition date, the results of operations and cash flows from Diners Club Italy and Dinit have been included in the Company's consolidated results of operations and cash flows.
	Acquisition of the net assets of Home Loan Center, Inc.
	On June 6, 2012, through its Discover Home Loans, Inc. subsidiary, the Company acquired substantially all of the operating and related assets and certain liabilities of Home Loan Center, Inc. ("Home Loan Center"), a subsidiary of Tree.com, Inc., adding a residential mortgage lending component to the Company's direct banking business. In exchange for the net assets acquired, the Company paid an aggregate of $49 million, including payments made prior to the closing that were applied to the closing price. A portion of such amount is being held in escrow pending Home Loan Center's ability to discharge certain contingent liabilities related to loans previously sold to secondary market investors. These contingent liabilities were not assumed by the Company. During the second quarter of the 2013 calendar year, an additional $10 million of purchase price due on the first anniversary of the closing was paid as certain conditions were satisfied. Since the acquisition date, the results of operations and cash flows of Discover Home Loans, Inc. have been included in the Company's consolidated results of operations and cash flows.

Investments

Investments	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
Investments	'
	Investments
	The Company’s investment securities consist of the following (dollars in millions):
		December 31,							November 30,
		2013			2012				2012				2011
	U.S. Treasury securities(1)	$	2,058		$	2,460			$	2,463			$	2,564
	U.S. government agency securities	1,561			2,233				2,237				2,795
	States and political subdivisions of states	15			34				34				41
	Other securities:
	Credit card asset-backed securities of other issuers	6			151				159				300
	Corporate debt securities(2)	—			—				75				450
	To-be-announced investment securities(3)	—			—				—				50
	Residential mortgage-backed securities - Agency(4)	1,351			1,354				1,253				6
	Total other securities	1,357			1,505				1,487				806
	Total investment securities	$	4,991		$	6,232			$	6,221			$	6,206
	-1	Includes $9 million of U.S. Treasury securities that have been pledged as swap collateral in lieu of cash as of December 31, 2013.
	-2	Amount represents corporate debt obligations issued under the Temporary Liquidity Guarantee Program (TLGP) that are guaranteed by the Federal Deposit Insurance Corporation (FDIC).
	-3	The Company’s to-be-announced investment securities are forward contracts for regular-way purchases of government agency mortgage-backed securities. They are accounted for as investment securities rather than as derivative instruments. These contracts are for the purchase of mortgage-backed securities with a stated coupon and original term to maturity but for which the specific underlying mortgage loans are not known at the inception of the contract or at the end of the reporting period.
	-4	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
	At December 31, 2013
	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
	At December 31, 2012
	Available-for-Sale Investment Securities(1)
	U.S. Treasury securities	$	2,413		$	46			$	—			$	2,459
	U.S. government agency securities	2,187			46				—				2,233
	Credit card asset-backed securities of other issuers	149			2				—				151
	Residential mortgage-backed securities - Agency	1,282			20				—				1,302
	Total available-for-sale investment securities	$	6,031		$	114			$	—			$	6,145
	Held-to-Maturity Investment Securities(2)
	U.S. Treasury securities(3)	$	1		$	—			$	—			$	1
	States and political subdivisions of states	34			—				—				34
	Residential mortgage-backed securities - Agency(4)	52			2				—				54
	Total held-to-maturity investment securities	$	87		$	2			$	—			$	89
	-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 as of December 31, 2013. Aggregate gross unrealized losses on investment securities were not material as of December 31, 2012 (dollars in millions):
		Number of Securities in a Loss Position		Less than 12 months								More than 12 months
				Fair				Unrealized				Fair			Unrealized
				Value				Losses				Value			Losses
	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 calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, the Company received $733 million, $1.8 billion, $1.3 billion and $113 million, respectively, of proceeds related to maturities, redemptions, or liquidation of investment securities. For the calendar year ended December 31, 2013, these proceeds primarily resulted from $220 million maturities of U.S. government agency securities, $273 million maturities of residential mortgage-backed securities and $144 million maturities of credit card asset-backed securities of other issuers. For the fiscal year ended November 30, 2012, the proceeds primarily resulted from $757 million maturities of U.S. government agency securities, $388 million maturities of U.S. Treasury securities and $370 million maturities of corporate debt securities. For the fiscal year ended November 30, 2011, $843 million of these proceeds related to maturities of credit card asset-backed securities of other issuers and for the one month ended December 31, 2012, $75 million of these proceeds related to maturities of corporate debt 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 $719 million during the calendar year ended December 31, 2013. The Company recognized gains on sales of available-for-sale investment securities of $2 million, 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 calendar year ended December 31, 2013. There were no gains or losses related to either other than temporary impairments or sales of investment securities during the fiscal year ended November 30, 2012 and one month ended December 31, 2012. During the fiscal year ended November 30, 2011, the Company recorded $2 million of other than temporary impairment ("OTTI") on held to maturity securities, which was recorded entirely in earnings. There were no gains or losses related to sales of investment securities during the fiscal year ended November 30, 2011.
	The Company records unrealized gains and losses on its available-for-sale investment securities in other comprehensive income. For the calendar year ended December 31, 2013, the Company recorded net unrealized losses of $82 million ($52 million after tax) in other comprehensive income. For the fiscal years ended November 30, 2012 and 2011, the Company recorded net unrealized gains of $30 million and $75 million ($19 million and $47 million after tax), respectively, in other comprehensive income. For the one month ended December 31, 2012, the Company recorded net unrealized losses of $5 million ($3 million after tax) in other comprehensive income.
Maturities and weighted average yields of available-for-sale debt securities and held-to-maturity debt securities at December 31, 2013 are provided in the tables below (dollars in millions):
	One Year			After One				After Five				After Ten			Total
	or			Year				Years				Years
	Less			Through				Through
				Five Years				Ten Years
Available-for-Sale—Amortized Cost(1)
U.S. Treasury securities	$	709		$	1,321			$	—			$	—		$	2,030
U.S. government agency securities	508			1,027				—				—			1,535
Credit card asset-backed securities of other issuers	6			—				—				—			6
Residential mortgage-backed securities - Agency	—			—				401				928			1,329
Total available-for-sale investment securities	$	1,223		$	2,348			$	401			$	928		$	4,900
Held-to-Maturity—Amortized Cost(2)
U.S. Treasury securities	$	1		$	—			$	—			$	—		$	1
State and political subdivisions of states	—			—				—				15			15
Residential mortgage-backed securities - Agency	—			—				—				44			44
Total held-to-maturity investment securities	$	1		$	—			$	—			$	59		$	60
Available-for-Sale—Fair Values(1)
U.S. Treasury securities	$	711		$	1,346			$	—			$	—		$	2,057
U.S. government agency securities	511			1,050				—				—			1,561
Credit card asset-backed securities of other issuers	6			—				—				—			6
Residential mortgage-backed securities - Agency	—			—				398				909			1,307
Total available-for-sale investment securities	$	1,228		$	2,396			$	398			$	909		$	4,931
Held-to-Maturity—Fair Values(2)
U.S. Treasury securities	$	1		$	—			$	—			$	—		$	1
State and political subdivisions of states	—			—				—				14			14
Residential mortgage-backed securities - Agency	—			—				—				43			43
Total held-to-maturity investment securities	$	1		$	—			$	—			$	57		$	58
-1	Available-for-sale investment securities are reported at fair value.
-2	Held-to-maturity investment securities are reported at amortized cost.
	One Year		After One			After Five			After Ten			Total
	or		Year			Years			Years
	Less		Through			Through
			Five Years			Ten Years
Available-for-Sale—Weighted Average Yields(1)
U.S Treasury securities	0.65	%	1.45	%		—	%		—	%		1.17	%
U.S government agency securities	0.92	%	1.72	%		—	%		—	%		1.46	%
Credit card asset-backed securities of other issuers	12.83	%	—	%		—	%		—	%		12.83	%
Residential mortgage-backed securities - Agency	—	%	—	%		1.44	%		1.96	%		1.8	%
Total available-for-sale investment securities	0.82	%	1.57	%		1.44	%		1.96	%		1.45	%
Held-to-Maturity—Weighted Average Yields
U.S. Treasury securities	0.08	%	—	%		—	%		—	%		0.08	%
State and political subdivisions of states	—	%	4.27	%		—	%		4.68	%		4.67	%
Residential mortgage-backed securities	—	%	—	%		—	%		3.27	%		3.27	%
Total held-to-maturity investment securities	0.08	%	4.27	%		—	%		3.63	%		3.6	%
-1	The weighted average yield for available-for-sale investment securities is calculated based on the amortized cost.
The following table presents interest on investment securities (dollars in millions):
	For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,								For the One Month Ended December 31, 2012
				2012				2011
Taxable interest	$	73		$	78			$	57			$	7
Tax exempt interest	1			2				2				—
Total income from investment securities	$	74		$	80			$	59			$	7
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 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 December 31, 2013 and 2012, the Company had outstanding investments in these entities of $308 million and $259 million, respectively, and related contingent liabilities of $52 million and $79 million, respectively.

Loan_Receivables

Loan Receivables	12 Months Ended
	Dec. 31, 2013
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):
		December 31,
		2013				2012
	Mortgage loans held for sale(1)	$	148			$	355
	Loan portfolio:
	Credit card loans:
	Discover card(2)	52,952				50,929
	Discover business card	198				206
	Total credit card loans	53,150				51,135
	Other loans:
	Personal loans	4,191				3,296
	Private student loans	3,969				3,072
	Other	135				38
	Total other loans	8,295				6,406
	Purchased credit-impaired loans(3)	4,178				4,702
	Total loan portfolio	65,623				62,243
	Total loan receivables	65,771				62,598
	Allowance for loan losses	(1,648		)		(1,788		)
	Net loan receivables	$	64,123			$	60,810
	-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 $20.2 billion and $18.8 billion underlying investors’ interest in trust debt at December 31, 2013 and 2012, respectively, and $10.9 billion and $16.0 billion in seller's interest at December 31, 2013 and 2012, respectively. The decrease in the seller's interest from December 31, 2012 to December 31, 2013 is due in part to the removal of randomly-selected accounts from the credit card loan receivables restricted for securitization investors in order to reduce excess seller's interest. See Note 6: Credit Card and Student Loan Securitization Activities for further information.
	-3	Amounts include $2.2 billion and $2.5 billion of loans pledged as collateral against the notes issued from the Student Loan Corporation ("SLC") securitization trusts at December 31, 2013 and 2012, respectively. See Note 6: Credit Card and Student Loan Securitization Activities. Of the remaining $2.0 billion and $2.2 billion at December 31, 2013 and 2012, respectively, that were not pledged as collateral, approximately $22 million and $17 million represent loans eligible for reimbursement through an indemnification claim, respectively. 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 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
	At December 31, 2012
	Credit card loans:
	Discover card(2)	$	455			$	458			$	913			$	407			$	183
	Discover business card	2				2				4				2				1
	Total credit card loans	457				460				917				409				184
	Other loans:
	Personal loans(3)	18				8				26				7				4
	Private student loans (excluding PCI)(4)	28				9				37				7				2
	Other	—				1				1				—				2
	Total other loans (excluding PCI)	46				18				64				14				8
	Total loan receivables (excluding PCI)	$	503			$	478			$	981			$	423			$	192
	-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 $29 million, $32 million, $45 million and $3 million for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, respectively. The Company does not separately track 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' current balances and most recent interest rates.
	-2	Consumer credit card loans that are 90 or more days delinquent and accruing interest include $41 million and $52 million of loans accounted for as troubled debt restructurings at December 31, 2013 and 2012, 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 both December 31, 2013 and 2012, respectively.
	-4	Private student loans that are 90 or more days delinquent and accruing interest include $3 million and $2 million of loans accounted for as troubled debt restructurings at December 31, 2013 and 2012.
	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 Calendar Year Ended December 31, 2013							For the Fiscal Years Ended November 30,													For the One Month Ended December 31, 2012
									2012							2011
	Net				Net			Net				Net			Net				Net		Net			Net
	Charge-offs				Charge-off Rate			Charge-offs				Charge-off Rate			Charge-offs				Charge-off Rate		Charge-offs			Charge-off Rate
Credit card loans:
Discover card	$	1,096			2.21	%		$	1,233			2.62	%		$	2,018			4.46	%	$	106		2.48	%
Discover business card	4				2.05	%		7				3.36	%		18				7.27	%	—			2.08	%
Total credit card loans	1,100				2.21	%		1,240				2.62	%		2,036				4.47	%	106			2.47	%
Other loans:
Personal loans	79				2.13	%		69				2.33	%		67				3.02	%	7			2.52	%
Private student loans (excluding PCI)	46				1.3	%		19				0.73	%		7				0.48	%	2			0.81	%
Other	1				1.96	%		—				0.1	%		2				9.27	%	—			—	%
Total other loans (excluding PCI)	126				1.67	%		88				1.52	%		76				1.65	%	9			1.61	%
Net charge-offs as a percentage of total loans (excluding PCI)	$	1,226			2.14	%		$	1,328			2.5	%		$	2,112			4.21	%	$	115		2.37	%
Net charge-offs as a percentage of total loans (including PCI)	$	1,226			1.98	%		$	1,328			2.29	%		$	2,112			3.97	%	$	115		2.19	%
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			Less than 660
	Above			or No Score
At December 31, 2013
Discover card	83	%		17	%
Discover business card	92	%		8	%
Personal loans	97	%		3	%
Private student loans (excluding PCI)(1)	95	%		5	%
At December 31, 2012
Discover card	83	%		17	%
Discover business card	91	%		9	%
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 and willing to make payments the ability to temporarily suspend payments. Eligible borrowers have a lifetime cap on forbearance of 12 months. At December 31, 2013 and 2012, there were $110 million and $183 million of private student loans, including PCI, in forbearance, respectively. In addition, at December 31, 2013 and 2012, there were 1.9% and 3.4% of private student loans in forbearance as a percentage of student loans in repayment and forbearance, respectively. At December 31, 2012, the dollar amount of loans in forbearance and loans in forbearance as a percentage of private student loans in repayment and forbearance were higher due to administrative forbearances that were offered to certain customers impacted by Hurricane Sandy.
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 "— Impaired Loans and 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 for the calendar year ended December 31, 2013, one month period ended December 30, 2012 and fiscal years ended November 30, 2012 and 2011 (dollars in millions):
	For the Calendar Year Ended December 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	893				92				84				17				1,086
Deductions:
Charge-offs	(1,604		)		(86		)		(48		)		(1		)		(1,739		)
Recoveries	504				7				2				—				513
Net charge-offs	(1,100		)		(79		)		(46		)		(1		)		(1,226		)
Balance at end of period	$	1,406			$	112			$	113			$	17			$	1,648
	For the One Month Ended December 31, 2012
	Credit Card				Personal Loans				Student Loans				Other				Total
Balance at beginning of period	$	1,554			$	97			$	73			$	1			$	1,725
Additions:
Provision for loan losses	165				9				4				—				178
Deductions:
Charge-offs	(146		)		(8		)		(2		)		—				(156		)
Recoveries	40				1				—				—				41
Net charge-offs	(106		)		(7		)		(2		)		—				(115		)
Balance at end of period	$	1,613			$	99			$	75			$	1			$	1,788
	For the Fiscal Year Ended November 30, 2012
	Credit Card				Personal Loans				Student Loans				Other				Total
Balance at beginning of period	$	2,070			$	82			$	53			$	—			$	2,205
Additions:
Provision for loan losses	724				84				39				1				848
Deductions:
Charge-offs	(1,817		)		(73		)		(19		)		—				(1,909		)
Recoveries	577				4				—				—				581
Net charge-offs	(1,240		)		(69		)		(19		)		—				(1,328		)
Balance at end of period	$	1,554			$	97			$	73			$	1			$	1,725
The following tables provide changes in the Company’s allowance for loan losses for the calendar year ended December 31, 2013, one month period ended December 30, 2012 and fiscal years ended November 30, 2012 and 2011 (dollars in millions):
	For the Fiscal Year Ended November 30, 2011
	Credit Card				Personal Loans				Student Loans				Other				Total
Balance at beginning of period	$	3,209			$	76			$	18			$	1			$	3,304
Additions:
Provision for loan losses	897				73				42				1				1,013
Deductions:
Charge-offs	(2,615		)		(69		)		(7		)		(2		)		(2,693		)
Recoveries	579				2				—				—				581
Net charge-offs	(2,036		)		(67		)		(7		)		(2		)		(2,112		)
Balance at end of period	$	2,070			$	82			$	53			$	—			$	2,205
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 Calendar Year Ended December 31, 2013				For the Fiscal Years Ended November 30,								For the One Month Ended December 31, 2012
					2012				2011
Interest and fees accrued subsequently charged off, net of recoveries (recorded as a reduction of interest income)	$	280			$	345			$	589			$	26
Fees accrued subsequently charged off, net of recoveries (recorded as a reduction to other income)	$	59			$	67			$	106			$	5
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 December 31, 2013
Allowance for loan losses 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 ASC 310-10-35(1)(2)	188				3				9				16				216
Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				28				—				28
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 ASC 310-10-35(1)(2)	1,123				31				28				79				1,261
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
At December 31, 2012
Allowance for loan losses evaluated for impairment as:
Collectively evaluated for impairment in accordance with ASC 450-20	$	1,433			$	95			$	71			$	1			$	1,600
Evaluated for impairment in accordance with ASC 310-10-35(1)(2)	180				4				4				—				188
Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				—				—				—
Allowance for loan losses	$	1,613			$	99			$	75			$	1			$	1,788
Recorded investment in loans evaluated for impairment as:
Collectively evaluated for impairment in accordance with ASC 450-20	$	49,826			$	3,275			$	3,056			$	38			$	56,195
Evaluated for impairment in accordance with ASC 310-10-35(1)(2)	1,309				21				16				—				1,346
Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				4,702				—				4,702
Total recorded investment	$	51,135			$	3,296			$	7,774			$	38			$	62,243
-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 $0.9 billion and $1.1 billion at December 31, 2013 and 2012 respectively. The unpaid principal balance of personal loans was $31 million and $21 million at December 31, 2013 and 2012, respectively. The unpaid principal balance of student loans was $26 million and $15 million at December 31, 2013 and 2012, 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.
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 internal programs 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 Calendar Year Ended December 31, 2013
Credit card loans
Modified credit card loans(3)	$	269			$	49			$	3
Internal programs	$	468			$	9			$	66
External programs	$	463			$	36			$	11
Personal loans	$	26			$	3			$	1
Student loans(4)	$	22			$	2			N/A
For the Fiscal Year Ended November 30, 2012
Credit card loans
Modified credit card loans(3)	$	255			$	48			N/A
Internal programs	$	557			$	17			$	73
External programs	$	603			$	51			$	9
Personal loans	$	16			$	2			N/A
Student loans(4)	$	10			$	1			N/A
For the Fiscal Year Ended November 30, 2011
Credit card loans
Modified credit card loans(3)	$	276			$	48			N/A
Internal programs	$	537			$	21			$	65
External programs	$	715			$	62			$	10
Personal loans	$	7			$	1			N/A
Student loans(4)	$	5			$	—			N/A
For the One Month Ended December 31, 2012
Credit card loans
Modified credit card loans(3)	$	281			$	4			$	—
Internal programs	$	509			$	1			$	6
External programs	$	530			$	4			$	1
Personal loans	$	21			$	—			N/A
Student loans(4)	$	16			$	—			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 that have subsequently reverted back to the loans' pre-modification payment terms either due to noncompliance with the terms of the modification or successful completion of a temporary modification 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 calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, the Company quantified the amount by which interest and fees were reduced during the periods. During the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, the Company forgave approximately $40 million, $44 million, $64 million and $3 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 Calendar Year Ended December 31, 2013							For the Fiscal Years Ended November 30,													For the One Month Ended December 31, 2012
								2012							2011
	Number of Accounts			Balances				Number of Accounts			Balances				Number of Accounts			Balances			Number of Accounts		Balances
Accounts that entered a loan modification program during the period:
Credit card:
Internal programs	40,653			$	256			50,946			$	345			68,738			$	480		3,078		$	19
External programs	35,020			$	189			40,530			$	227			52,705			$	310		2,614		$	14
Personal loans	2,178			$	27			1,555			$	20			410			$	5		120		$	2
Student loans	877			$	17			470			$	11			262			$	5		60		$	2
The following table presents the carrying value of loans that experienced a payment default during the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012 that had been modified in a troubled debt restructuring during the 15 months preceding the end of each period (dollars in millions):
	For the Calendar Year Ended December 31, 2013							For the Fiscal Years Ended November 30,													For the One Month Ended December 31, 2012
								2012							2011
	Number of Accounts			Aggregated Outstanding Balances Upon Default				Number of Accounts			Aggregated Outstanding Balances Upon Default				Number of Accounts			Aggregated Outstanding Balances Upon Default			Number of Accounts		Aggregated Outstanding Balances Upon Default
Troubled debt restructurings that subsequently defaulted:
Credit card (1)(2):
Internal programs	9,186			$	57			15,703			$	106			18,354			$	131		945		$	6
External programs	8,481			$	36			8,543			$	40			11,974			$	62		722		$	3
Personal loans(2)	284			$	3			343			$	4			17			$	—		22		$	—
Student loans(3)	628			$	12			172			$	4			19			$	1		42		$	1
-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 calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, approximately 40%, 46%, 40% and 39%, respectively, of the total balances were 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 December 31, 2013 and 2012. Total PCI student loans had an outstanding balance of $4.6 billion and $5.2 billion, including accrued interest, and a related carrying amount of $4.2 billion and $4.7 billion, as of December 31, 2013 and 2012, respectively.
The following table provides changes in accretable yield for the acquired loans for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012 (dollars in millions):
	For the Calendar Year Ended December 31, 2013				For the Fiscal Years Ended November 30,								For the One Month Ended December 31, 2012
					2012				2011
Balance at beginning of period	$	2,072			$	2,580			$	—			$	2,096
Acquisition of the Student Loan Corporation	—				—				1,920				—
Acquisition of the additional private student loan portfolio from Citibank	—				—				855				—
Accretion into interest income	(272		)		(303		)		(225		)		(24		)
Other changes in expected cash flows	(220		)		(181		)		30				—
Balance at end of period	$	1,580			$	2,096			$	2,580			$	2,072
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 a $28 million provision expense during the calendar year ended December 31, 2013 due to higher expected future losses for one of its pools. The allowance for PCI loan losses at December 31, 2013 was $28 million. Additionally, changes to other cash flow assumptions resulted in a decrease in accretable yield related to expected life of the loans for the calendar year ended December 31, 2013 and fiscal year ended November 30, 2012 and increase in accretable yield for the fiscal year ended November 30, 2011. There was no impact on accretable yield as a result of changes in cash flow assumptions for the one month ended December 31, 2012. Changes to accretable yield are recognized prospectively as an adjustment to yield over the remaining life of the pools.
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. At December 31, 2012, 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 2.68% and 0.86%, 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 for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012 was 1.36%, 1.41%, 1.34% and 1.53%, respectively.
Mortgage Loans Held for Sale
The Company originates all of its residential real estate 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 22: 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 by type of loan for the calendar year ended December 31, 2013, fiscal year ended November 30, 2012 and one month ended December 31, 2012 (dollars in millions):
	For the Calendar Year Ended December 31, 2013							For the Fiscal Year Ended November 30, 2012							For the One Month Ended December 31, 2012
	Amount				%			Amount				%			Amount				%
Conforming(1)	$	2,721			67.77	%		$	1,213			70.28	%		$	218			60.06	%
FHA(2)	1,290				32.13			513				29.72			145				39.94
Jumbo(3)	4				0.1			—				—			—				—
Total	$	4,015			100	%		$	1,726			100	%		$	363			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 as of December 31, 2013 and 2012 (dollars in millions):
	December 31,
	2013							2012
	Amount				%			Amount				%
Conforming(1)	$	136			91.89	%		$	177			49.86	%
FHA(2)	11				7.43			178				50.14
Jumbo(3)	1				0.68			—				—
Total	$	148			100	%		$	355			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.
Geographical Distribution of Loans
The Company originates credit card loans throughout the United States. The geographic distribution of the Company's credit card loan receivables was as follows (dollars in millions):
	December 31,
	2013							2012
	$				%			$				%
California	$	4,548			8.5	%		$	4,442			8.7	%
Texas	4,299				8.1			4,090				8
New York	3,649				6.9			3,457				6.8
Florida	3,064				5.8			2,949				5.8
Illinois	2,998				5.6			2,903				5.7
Pennsylvania	2,823				5.3			2,703				5.3
Ohio	2,324				4.4			2,233				4.4
New Jersey	2,002				3.8			1,940				3.8
Michigan	1,575				3			1,537				3
Georgia	1,546				2.9			1,499				2.9
Other States	24,322				45.7			23,382				45.6
Total credit card loans	$	53,150			100	%		$	51,135			100	%
The Company originates personal loans, student loans, other loans and PCI loans throughout the United States. The table below does not include mortgage loans held for sale. The geographic distribution of personal, student, other and PCI loan receivables was as follows (dollars in millions):
	December 31,
	2013							2012
	$				%			$				%
New York	$	1,679			13.4	%		$	1,614			14.5	%
California	1,167				9.4			1,039				9.4
Pennsylvania	939				7.5			877				7.9
Illinois	696				5.6			612				5.5
Texas	637				5.1			542				4.9
New Jersey	630				5.1			570				5.1
Massachusetts	508				4.1			463				4.2
Michigan	482				3.9			436				3.9
Ohio	481				3.9			418				3.8
Florida	479				3.8			419				3.8
Other States	4,775				38.2			4,118				37
Total other loans (including PCI loans)	$	12,473			100	%		$	11,108			100	%

Credit_Card_and_Student_Loan_S

Credit Card and Student Loan Securitization Activities	12 Months Ended
	Dec. 31, 2013
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 consolidated statements of financial condition.
	Upon transfer of credit card loan receivables to the trust, the receivables and certain cash flows derived from them become restricted for use in meeting obligations to the 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 consolidated statement of financial condition as relating to securitization activities, are shown in the table below (dollars in millions):
		December 31,
		2013			2012
	Cash collateral accounts	$	59		$	93
	Collections and interest funding accounts	31			91
	Restricted cash	90			184
	Investors’ interests held by third-party investors	15,190			13,768
	Investors’ interests held by wholly owned subsidiaries of Discover Bank	5,024			5,038
	Seller’s interest	10,898			15,976
	Loan receivables(1)	31,112			34,782
	Allowance for loan losses allocated to securitized loan receivables(1)	(833		)	(1,110		)
	Net loan receivables	30,279			33,672
	Other	34			29
	Carrying value of assets of consolidated variable interest entities	$	30,403		$	33,885
	-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. In 2013, accounts were randomly selected to be removed from credit card loan receivables restricted for securitization investors in the amount of $3 billion to reduce excess seller's interest. The removal freed up the accounts to be pledged at the Federal Reserve discount window, allowing the Company to increase its borrowing capacity. The Company satisfied all requirements, including the minimum seller's interest requirement, in order to complete the account removal.
	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 December 31, 2013, no economic or other early amortization events have occurred.
	The tables below provide information concerning investors’ interests and related excess spreads at December 31, 2013 (dollars in millions):
		Investors’			# of Series
		Interests(1)			Outstanding
	Discover Card Master Trust I	$	918		2
	Discover Card Execution Note Trust (DiscoverSeries notes)	19,296			37
	Total investors’ interests	$	20,214		39
	-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	14.17	%
	DiscoverSeries excess spread percentage	14.15	%
	-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 consolidated statements of financial condition as relating to securitization activities, are shown in the table below (dollars in millions):
		December 31,
		2013			2012
	Restricted cash	$	89		$	96
	Student loan receivables	2,248			2,539
	Allowance for loan losses allocated to securitized loan receivables(1)	(28		)	—
	Net student loan receivables	2,220			2,539
	Carrying value of assets of consolidated variable interest entities	$	2,309		$	2,635
	-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.

Premises_and_Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Premises and Equipment	'
	Premises and Equipment
	A summary of premises and equipment, net is as follows (dollars in millions):
		December 31,
		2013			2012
	Land	$	43		$	42
	Buildings and improvements	547			517
	Capitalized equipment leases	2			2
	Furniture, fixtures and equipment	735			640
	Software	391			414
	Premises and equipment	1,718			1,615
	Less: Accumulated depreciation	(829		)	(764		)
	Less: Accumulated amortization of software	(235		)	(313		)
	Premises and equipment, net	$	654		$	538
	Depreciation expense, including amortization of assets recorded under capital leases, was $65 million, $63 million, $60 million and $6 million for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, respectively. Amortization expense on capitalized software was $41 million, $32 million, $30 million and $3 million for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, respectively.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Intangible Assets	'
	Goodwill and Intangible Assets
	Goodwill
	As of December 31, 2013 and 2012, the Company had goodwill of $284 million and $286 million, respectively. In 2012, $31 million of goodwill was recorded in connection with its acquisition of substantially all of the operating and related assets and certain liabilities of Home Loan Center (see Note 3: Business Combinations), which was allocated to the Direct Banking segment. In 2013, a $2 million adjustment was recorded to reduce goodwill as a result of the finalization of purchase accounting for this acquisition. Additionally, the Company has goodwill of $255 million resulting from its previous acquisition of PULSE, which was allocated to the Payment Services segment.
	The Company conducted its annual goodwill impairment test on June 1, 2013 and 2012, at which times management concluded that there was no impairment to goodwill. During the fourth quarter of 2013, the Company changed the date of its annual goodwill impairment test to October 1 and performed an additional impairment test which also resulted in management's conclusion that there was no impairment to goodwill. Additional information regarding the change in the annual goodwill impairment testing date is discussed in Note 2: Summary of Significant Accounting Policies.
	Intangible Assets
	The Company's amortizable intangible assets resulted from various acquisitions. The May 2013 acquisition of Diners Club Italy, which is part of the Payment Services segment, resulted in the recognition of amortizable intangible assets primarily related to customer relationships. The June 2012 acquisition of Home Loan Center, which is part of the Direct Banking segment, resulted in the recognition of amortizable intangible assets related to proprietary software, non-compete agreements and marketing agreements. The December 2010 acquisition of SLC, which is part of the Direct Banking segment, resulted in the recognition of an amortizable intangible asset relating to acquired customer relationships. The 2005 acquisition of PULSE, which is part of the Payment Services segment, resulted in the recognition of amortizable intangible assets relating to acquired customer relationships and trade name intangibles. Acquired customer relationships for Diners Club Italy consist of those relationships in existence between Diners Club Italy and their customers that have a Diners Club charge card as valued at the date of the acquisition. Acquired customer relationships for SLC consist of those relationships in existence between SLC and the numerous students that carry student loan balances, while for PULSE they consist of those relationships in existence between PULSE and the numerous financial institutions that participate in its network, as valued at the date of the respective acquisition.
	Non-amortizable intangible assets consist of trade name intangibles recognized in the acquisition of SLC, along with international transaction processing rights and trade name intangibles recognized in the acquisition of Diners Club in June 2008. During the fourth quarter of 2013, the Company changed the date of its annual impairment test for non-amortizable intangible assets from June 1 to October 1 to coincide with the change in the Company's goodwill impairment test date. No impairment charges were identified during the impairment tests conducted at June 1, 2013 and 2012 or October 1, 2013.
	The following table summarizes the Company's intangible assets (dollars in millions):
				December 31,
				2013						2012
		Weighted Average Amortization Period		Gross Carrying Amount		Accumulated Amortization		Net		Gross Carrying Amount		Accumulated Amortization		Net
								Book Value						Book Value
	Amortizable intangible assets:
	Customer relationships	13.7 years		$	78	$	60	$	18	$	72	$	52	$	20
	Trade name and other	25 years		8		2		6		8		2		6
	Proprietary software	7 years		6		2		4		6		1		5
	Non-compete agreements	3 years		2		1		1		2		—		2
	Marketing agreements and other	13 months		6		5		1		4		3		1
	Total amortizable intangible assets			100		70		30		92		58		34
	Non-amortizable intangible assets:
	Trade names	N/A		132		—		132		132		—		132
	International transaction processing rights	N/A		23		—		23		23		—		23
	Total non-amortizable intangible assets			155		—		155		155		—		155
	Total intangible assets			$	255	$	70	$	185	$	247	$	58	$	189
	Amortization expense related to the Company's intangible assets was $12 million, $11 million, $8 million and $1 million for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, respectively.
	The following table presents expected intangible asset amortization expense for the next five years based on intangible assets at December 31, 2013 (dollars in millions):
	Year	Amount
	2014	$	9
	2015	$	5
	2016	$	4
	2017	$	3
	2018	$	3

Deposits

Deposits	12 Months Ended
	Dec. 31, 2013
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 December 31, 2013 and 2012, the Company had approximately $28.4 billion and $28.0 billion, respectively, of direct-to-consumer deposits and approximately $16.4 billion and $14.1 billion, respectively, of brokered deposits.
	A summary of interest-bearing deposit accounts is as follows (dollars in millions):
		December 31,
		2013			2012
	Certificates of deposit in amounts less than $100,000(1)	$	21,211		$	21,070
	Certificates of deposit from amounts of $100,000(1) to less than $250,000(1)	4,860			5,508
	Certificates of deposit in amounts of $250,000(1) or greater	1,180			1,280
	Savings deposits, including money market deposit accounts	17,515			14,219
	Total interest-bearing deposits	$	44,766		$	42,077
	Average annual interest rate	1.57		%	1.74		%
	-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 December 31, 2013, certificates of deposit maturing over the next five years, and thereafter were as follows (dollars in millions):
	Year	Amount
	2014	$	12,226
	2015	$	6,301
	2016	$	3,475
	2017	$	2,198
	2018	$	1,691
	Thereafter	$	1,360

LongTerm_Borrowings

Long-Term Borrowings	12 Months Ended
	Dec. 31, 2013
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):
		December 31,
		2013				2012
		Outstanding		Interest		Outstanding		Interest		Interest Rate Terms	Maturity
				Rate				Rate
	Securitized Debt
	Fixed rate asset-backed securities
	Principal value	$	5,549	1.86	%	$	4,549	2.87	%	Various fixed rates	Various
	(including discount of $1 at December 31, 2013 and December 31, 2012)										February 2015 - July 2019
	Fair value adjustment(1)	5				6
	Book value	5,554				4,555
	Floating rate asset-backed securities	9,140		0.46	%	8,468		0.5	%	1-month LIBOR (2) +	Various
										8 to 58 basis points	February 2014 - October 2018
	Floating rate asset-backed securities	500		0.44	%	750		0.64	%	Commercial Paper	Mar-14
										rate + 30 basis points
	Total Discover Card Master Trust I and Discover Card Execution Note Trust	15,194				13,773
	Floating rate asset-backed securities	1,005		0.48	%	1,199		0.56	%	3-month LIBOR (2) +	Various
	(including discount of $129 and $173 at December 31, 2013 and December 31, 2012, respectively)									12 to 45 basis points	January 2019 - July 2036 (3)
	Floating rate asset-backed securities	434		4.25	%	528		4.25	%	Prime rate + 100 basis points	June 2031 (3)
	(including discount of $3 at December 31, 2013 and December 31, 2012)
	Floating rate asset-backed securities	105		4	%	126		4	%	Prime rate +	July 2042 (3)
	(including premium of $1 and $2 at December 31, 2013 and December 31, 2012, respectively)									75 basis points
	Floating rate asset-backed securities	248		3.66	%	307		3.71	%	1-month LIBOR (2) +	July 2042 (3)
	(including premium of $3 and $5 at December 31, 2013 and December 31, 2012, respectively)									350 basis points
	Total SLC Private Student Loan Trusts	1,792				2,160
	Total long-term borrowings – owed to securitization investors	16,986				15,933
	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)	13				21
	Book value	413				421
	Fixed rate senior notes due 2019	78		10.25	%	78		10.25	%	Fixed	Jul-19
	Fixed rate senior notes due 2022	219		5.2	%	211		5.2	%	Fixed	Apr-22
	(including discount of $103 and $110 at December 31, 2013 and December 31, 2012, respectively)
	Fixed rate senior notes due 2022	335		3.85	%	324		3.85	%	Fixed	Nov-22
	(including discount of $165 and $176 at December 31, 2013 and December 31, 2012, respectively)
	Discover Bank
	Senior bank notes due 2018	750		2	%	—		—	%	Fixed	Feb-18
	Senior bank notes due 2023	994		4.2	%	—		—	%	Fixed	Aug-23
	(including discount of $6 at December 31, 2013)
	Subordinated bank notes due 2019	200		8.7	%	200		8.7	%	Fixed	November 2019
	Subordinated bank notes due 2020	498		7	%	497		7	%	Fixed	April 2020
	(including discount of $2 and $3 at December 31, 2013 and December 31, 2012, respectively)
	Capital lease obligations	1		4.51	%	2		4.51	%	Fixed	Apr-16
	Total long-term borrowings	$	20,474			$	17,666
	-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 22: 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.
	Maturities
	Long-term borrowings had the following maturities at December 31, 2013 (dollars in millions):
	Year	Amount
	Due in 2014	$	4,290
	Due in 2015	3,305
	Due in 2016	3,050
	Due in 2017	2,062
	Due in 2018	2,650
	Thereafter	5,117
	Total	$	20,474
	In the fourth quarter of the 2012 fiscal year, the Company completed a private exchange offer, resulting in the exchange of $500 million outstanding aggregate principal amount of 8.70% Subordinated Notes due 2019 issued by Discover Bank for the same aggregate principal amount of new 3.85% Senior Notes due 2022 issued by Discover Financial Services and a cash premium paid of $176 million. The exchange was accounted for as a debt modification and not as an extinguishment. The entire outstanding aggregate principal amount of these notes was subsequently exchanged for substantially identical notes that were registered under the Securities Act of 1933. During the calendar year ended December 31, 2013 and one month ended December 31, 2012, respectively, $11 million and $1 million of the premium paid was amortized and included in interest expense on the consolidated statements of income.
	During second quarter of the 2012 fiscal year, the Company completed a private exchange offer, resulting in the exchange of $322 million outstanding aggregate principal amount of 10.25% Senior Notes due 2019 for the same aggregate principal amount of new 5.20% Senior Notes due 2022 and a cash premium paid of $115 million. The exchange was accounted for as a debt modification and not as an extinguishment. These notes were subsequently exchanged for substantially identical notes that were registered under the Securities Act of 1933. During the calendar year ended December 31, 2013, fiscal year ended November 30, 2012 and one month ended December 31, 2012, respectively, $7 million, $4 million and $1 million of the premium paid was amortized and included in interest expense on the consolidated statements of income.
	The Company has access to committed undrawn capacity through private securitizations to support the funding of its credit card loan receivables. As of December 31, 2013, the total commitment of secured credit facilities through private providers was $7.5 billion, of which $500 million had been used and was included in long-term borrowings at December 31, 2013. 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 calendar years 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.

StockBased_Compensation_Plans

Stock-Based Compensation Plans	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation Plans	'
	Stock-Based Compensation Plans
	The Company has two stock-based compensation plans: the Discover Financial Services Omnibus Incentive Plan and the Discover Financial Services Directors' Compensation Plan.
	Omnibus Incentive Plan
	The Discover Financial Services Omnibus Incentive Plan (“Omnibus Plan”), which is stockholder-approved, provides for the award of stock options, stock appreciation rights, restricted stock, restricted stock units (“RSUs”), performance stock units (“PSUs”) and other stock-based and/or cash awards (collectively, “Awards”). Currently, the Company does not have any stock appreciation rights or restricted stock outstanding. The total number of shares that may be granted is 45 million shares, subject to adjustments for certain transactions as described in the Omnibus Plan document. Shares granted under the Omnibus Plan may be the following: (i) authorized but unissued shares, and (ii) treasury shares that the Company acquires in the open market, in private transactions or otherwise.
	Directors' Compensation Plan
	The Discover Financial Services Directors' Compensation Plan (the “Directors' Compensation Plan”), which is stockholder-approved, permits the grant of RSUs to non-employee directors. The total number of units available for grant under the Directors' Compensation Plan equals the excess, if any, of (i) 1,000,000 shares over (ii) the sum of (a) the number of shares subject to outstanding awards granted under the Directors' Compensation Plan and (b) the number of shares previously issued pursuant to the Directors' Compensation Plan. Shares of stock that are issuable pursuant to the awards granted under the Directors' Compensation Plan may be authorized but unissued shares, treasury shares or shares that the Company acquires in the open market. Annual awards for eligible directors are calculated by dividing $125,000 by the fair market value of a share of stock on the date of grant and are subject to a restriction period whereby 100% of such units shall vest on the first anniversary of the date of grant.
	Stock-Based Compensation
	The following table details the compensation cost, net of forfeitures (dollars in millions):
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011
	Restricted stock units	$	31		$	29		$	34		$	2
	Performance stock units	28			18			10			1
	Total stock-based compensation expense	$	59		$	47		$	44		$	3
	Income tax benefit	$	22		$	18		$	17		$	1
	Restricted Stock Unit Activity
	The following table sets forth the activity related to vested and unvested RSUs during the calendar year ended December 31, 2013 and one month ended December 31, 2012:
		Number of Units		Weighted-Average Grant-Date Fair Value			Aggregate
							Intrinsic Value
							(in millions)
	Restricted stock units at November 30, 2012	4,771,746		$	21.01
	Granted	2,425		$	41.23
	Conversions to common stock	—		$	—
	Forfeited	—		$	—
	Restricted stock units at December 31, 2012	4,774,171		$	21.02		$	181
	Granted	998,263		$	42.14
	Conversions to common stock	(1,565,574	)	$	17.33
	Forfeited	(62,945	)	$	26.83
	Restricted stock units at December 31, 2013	4,143,915		$	27.38		$	232
	The following table sets forth the activity related to unvested RSUs during the calendar year ended December 31, 2013 and one month ended December 31, 2012:
		Number of Units		Weighted-Average Grant-Date Fair Value
	Unvested restricted stock units at November 30, 2012(1)	2,964,707		$	19.62
	Granted	2,425		$	41.23
	Vested	—		$	—
	Forfeited	—		$	—
	Unvested restricted stock units at December 31, 2012(1)	2,967,132		$	19.64
	Granted	998,263		$	42.14
	Vested	(1,404,830	)	$	19.41
	Forfeited	(62,945	)	$	26.83
	Unvested restricted stock units at December 31, 2013(1)	2,497,620		$	28.52
	-1	Unvested restricted stock units represent awards where recipients have yet to satisfy either explicit vesting terms or retirement-eligibility requirements.
	Compensation cost associated with restricted stock units is determined based on the number of units granted and the fair value on the date of grant. The fair value is amortized on a straight-line basis, net of estimated forfeitures over the requisite service period for each separately vesting tranche of the award. The requisite service period is generally the vesting period.
	The following table summarizes the total intrinsic value of the RSUs converted to common stock and the total grant date fair value of RSUs vested (dollars in millions, except weighted average grant date fair value amounts):
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011
	Intrinsic value of RSUs converted to common stock	$	63		$	49		$	30		$	—
	Grant date fair value of RSUs vested	$	27		$	28		$	35		$	—
	Weighted average grant date fair value of RSUs granted	$	42.14		$	25.64		$	19.57		$	41.23
	As of December 31, 2013 and 2012, there was $28 million and $19 million, respectively, of total unrecognized compensation cost related to non-vested RSUs. The cost is expected to be recognized over a total period of 2.1 years and 3.0 years, respectively, and a weighted average period of 2.8 years and 1.8 years, respectively.
	Performance Stock Unit Activity
	The following table sets forth the activity related to vested and unvested PSUs during the calendar year ended December 31, 2013 and one month ended December 31, 2012:
		Number of Units		Weighted Average Grant-Date Fair Value			Aggregate Intrinsic Value (in millions)
	Performance stock units at November 30, 2012	1,332,296		$	21.74
	Granted	—		$	—
	Conversions to common stock	—		$	—
	Forfeited	—		$	—
	Performance stock units at December 31, 2012	1,332,296		$	21.74		$	51
	Granted	581,520		$	38.89
	Conversions to common stock	—		$	—
	Forfeited	(15,949	)	$	29.2
	Performance stock units at December 31, 2013	1,897,867		$	26.93		$	106
	The following table sets forth the activity related to unvested PSUs during the calendar year ended December 31, 2013 and one month ended December 31, 2012:
		Number of Units		Weighted-Average Grant-Date Fair Value
	Unvested performance stock units at November 30, 2012	1,187,306		$	22.06
Granted	—		$	—
Vested(1)	—		$	—
Forfeited	—		$	—
Unvested performance stock units at December 31, 2012	1,187,306		$	22.06
Granted	581,520		$	38.89
Vested(1)	(100,585	)	$	24.39
Forfeited	(15,949	)	$	29.2
Unvested performance stock units at December 31, 2013(2)(3)(4)	1,652,292		$	27.77
-1	Vested performance stock units represent awards where recipients have satisfied retirement-eligibility requirements.
-2	Includes 559,114 performance stock units granted in fiscal year 2011 that are earned based on the Company's achievement of EPS during the two-year performance period ended November 30, 2012 and are subject to the requisite service period which ended January 2, 2014.
-3	Includes 518,438 performance stock units granted in fiscal year 2012 that are earned based on the Company's achievement of EPS during the two-year performance period ended November 30, 2013 and are subject to the requisite service period which ends January 2, 2015.
-4	Includes 574,740 performance stock units granted in calendar year 2013 that may be earned based on the Company's achievement of EPS during the three-year performance period which ends December 31, 2015 and are subject to the requisite service period which ends February 1, 2016.
Compensation cost associated with performance stock units is determined based on the number of instruments granted, the fair value on the date of grant, and the performance factor. The fair value is amortized on a straight-line basis, net of estimated forfeitures over the requisite service period. Each PSU is a restricted stock instrument that is subject to additional conditions and constitutes a contingent and unsecured promise by the Company to pay shares of the Company's common stock on the conversion date for the PSU contingent on the number of PSUs to be issued. PSUs granted in fiscal years 2011 and 2012 pay up to two shares per unit, whereas PSUs granted in calendar year 2013 pay up to 1.5 shares per unit. Additionally, PSUs granted in fiscal year 2011 and 2012 have a performance period of two years and a vesting period of three years, whereas PSUs granted in calendar year 2013 have a performance period of three years and a vesting period of three years. The requisite service period of an award, having both performance and service conditions, is the longest of the explicit, implicit and derived service periods.
As of December 31, 2013, there was $34 million of total unrecognized compensation cost related to non-vested PSUs. The cost is expected to be recognized over a total period of 2.1 years for non-retirement eligible employees and retirement eligible employees, with a weighted-average period of 0.8 years. As of December 31, 2012, there was $24 million of total unrecognized compensation cost related to non-vested PSUs. The cost is expected to be recognized over a total period of 2.0 years for non-retirement eligible employees and 0.9 years for retirement eligible employees, with a weighted-average period of 1.2 years.
Stock Option Activity
Option awards are granted with an exercise price equal to the fair market value of one share of the Company's common stock at the date of grant; these types of awards expire ten years from the grant date and may be subject to restrictions on transfer, vesting requirements, which are set at the discretion of the Compensation and Leadership Development Committee of the Company's board of directors, or cancellation under specified circumstances. Stock awards also may be subject to similar restrictions determined at the time of grant under this plan. Certain option and stock awards provide for accelerated vesting if there is a change in control or upon certain terminations (as defined in the Omnibus Plan or the award certificate).
The following table sets forth the activity concerning stock option activity during the calendar year ended December 31, 2013 and one month ended December 31, 2012:
	Number of Units		Weighted Average Exercise Price			Weighted-Average Remaining Contractual Term		Aggregate Intrinsic Value (in millions)
						(in years)
Options outstanding at November 30 2012	840,146		$	20.11		1.75 years
Granted(1)	—		$	—
Exercised	(301,677	)	$	18.87
Expired	—		$	—
Options outstanding at December 31, 2012	538,469		$	20.82		1.92 years		$	10
Granted(1)	—		—
Exercised	(366,743	)	$	18.46
Expired	—		$	—
Options outstanding at December 31, 2013	171,726		$	25.82		2.76 years		$	5
Vested and exercisable at December 31, 2013	171,726		$	25.82		2.76 years		$	5
-1	No stock options have been granted by the Company since its spin-off from Morgan Stanley.
Cash received from the exercise of stock options was $7 million and $6 million and the income tax benefit realized from the exercise of stock options was $3 million and $2 million for the calendar year ended December 31, 2013 and one month ended December 31, 2012, respectively.
The following table summarizes the total intrinsic value of options exercised and total fair value of options vested (dollars in millions):
	For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
				2012			2011
Intrinsic value of options exercised	$	11		$	22		$	9		$	6
As of December 31, 2013 and 2012 there was no unrecognized compensation cost related to non-vested stock options granted under the Company's Omnibus Plan, as all these options have vested.
The Company utilized the Black-Scholes pricing model to estimate the fair value of each option at its date of grant. The fair value was amortized on a straight-line basis, net of estimated forfeitures, over the requisite service periods of the awards, which is generally the vesting period. Use of a valuation model requires management to make certain assumptions with respect to selected model inputs. Since all options were granted prior to the Company's spin-off from Morgan Stanley, the expected option life of stock options and the expected dividend yield of stock were determined based upon Morgan Stanley's historical experience. The expected stock price volatility was determined based upon Morgan Stanley's historical stock price data over a time period similar to the expected option life. The risk-free interest rate was based on U.S. Treasury Strips with a remaining term equal to the expected life assumed at the date of grant.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]	'
Employee Benefit Plans	'
	Employee Benefit Plans
	The Company sponsors the Discover Financial Services Pension Plan (the "Discover Pension Plan"), which is a non-contributory defined benefit plan that is qualified under Section 401(a) of the Internal Revenue Code, for eligible employees in the U.S. Effective December 31, 2008, the Discover Pension Plan was amended to discontinue the accrual of future benefits. The Company also sponsors the Discover Financial Services 401(k) Plan (the “Discover 401(k) Plan”), which is a defined contribution plan that is qualified under Section 401(a) of the Internal Revenue Code, for its eligible U.S. employees.
	Defined Benefit Pension and Other Postretirement Plans
	The Discover Pension Plan generally provides retirement benefits that are based on each participant's years of credited service prior to 2009 and on compensation specified in the Discover Pension Plan. The Company's policy is to fund at least the amounts sufficient to meet minimum funding requirements under the Employee Retirement Income Security Act of 1974 (“ERISA”). The Company also participates in a self-funded postretirement benefit plan that provides medical and life insurance for eligible U.S. retirees and their dependents.
	Net Periodic Benefit Cost
	Net periodic benefit cost expensed by the Company included the following components (dollars in millions):
		Pension															Postretirement
		For the Calendar Year Ended December 31, 2013				For the Fiscal Years Ended November 30,							For the One Month Ended December 31, 2012				For the Calendar Year Ended December 31, 2013				For the Fiscal Years Ended November 30,					For the One Month Ended December 31, 2012
						2012				2011											2012			2011
	Service cost, benefits earned during the period	$	—			$	—			$	—		$	—			$	—			$	1		$	1	$	—
	Interest cost on projected benefit obligation	21				21				21			2				1				2			1		—
	Expected return on plan assets	(23		)		(23		)		(23		)	(2		)		—				—			—		—
	Net amortization	5				3				1			—				(1		)		—			—		—
	Net periodic benefit cost (income)	$	3			$	1			$	(1	)	$	—			$	—			$	3		$	2	$	—
	Accumulated Other Comprehensive Income
	As of December 31, 2013, pretax amounts recognized in accumulated other comprehensive income that have not yet been recognized as components of net periodic benefit cost consist of (dollars in millions):
		Pension				Postretirement
	Prior service credit (cost)	$	7			$	(1	)
	Net (loss) gain	(186		)		18
	Total	$	(179	)		$	17
	Benefit Obligations and Funded Status
	The following table provides a reconciliation of the changes in the benefit obligation and fair value of plan assets as well as a summary of the Company’s funded status (dollars in millions):
		Pension								Postretirement
		For the Calendar Year Ended December 31, 2013				For the One Month Ended December 31, 2012				For the Calendar Year Ended December 31, 2013			For the One Month Ended December 31, 2012
	Reconciliation of benefit obligation:
	Benefit obligation at beginning of year	$	523			$	535			$	13		$	13
	Service cost	—				—				—			—
	Interest cost	21				2				1			—
	Employee contributions	—				—				1			—
	Actuarial (gain) loss	(78		)		(13		)		(1		)	—
	Plan amendments	—				—				—			—
	Benefits paid	(14		)		(1		)		(1		)	—
	Benefit obligation at end of year	$	452			$	523			$	13		$	13
	Reconciliation of fair value of plan assets:
	Fair value of plan assets at beginning of year	$	368			$	368			$	—		$	—
	Actual return on plan assets	13				1				—			—
	Employer contributions	—				—				—			—
	Employee contributions	—				—				1			—
	Benefits paid	(14		)		(1		)		(1		)	—
	Fair value of plan assets at end of year	$	367			$	368			$	—		$	—
	Funded status (recorded in accrued expenses and other liabilities)	$	(85	)		$	(155	)		$	(13	)	$	(13	)
	Assumptions
	The following table presents the assumptions used to determine benefit obligations:
		Pension						Postretirement
		31-Dec-13			31-Dec-12			31-Dec-13			31-Dec-12
	Discount rate	4.93	%		4.09	%		4.29	%		4.09	%
	The following table presents the assumptions used to determine net periodic benefit cost:
		Pension											Postretirement
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011								2012			2011
	Discount rate	4.09	%		5.07	%		5.64	%		3.96	%	4.09	%		5.07	%		5.64	%		3.96	%
	Expected long-term rate of return on plan assets	6.75	%		6.75	%		6.75	%		6.75	%	N/A			N/A			N/A			N/A
	For the Discover Pension Plan, the expected long-term rate of return on plan assets was estimated by computing a weighted average return of the underlying long-term expected returns on the different asset classes, based on the target asset allocations. Asset class return assumptions are created by integrating information on past capital market performance, current levels of key economic indicators, and the market insights of investment professionals. Individual asset classes are analyzed as part of a larger system, acknowledging both the interaction between asset classes and the influence of larger macroeconomic variables such as inflation and economic growth on the entire structure of capital markets. Medium and long-term economic outlooks for the U.S. and other major industrial economies are forecast in order to understand the range of possible economic scenarios and evaluate their likelihood. Historical relationships between key economic variables and asset class performance patterns are analyzed using empirical models. Finally, comprehensive asset class performance projections are created by blending descriptive asset class characteristics with capital market insight and the initial economic analyses. The expected long-term return on plan assets is a long-term assumption that generally is expected to remain the same from one year to the next but is adjusted if there is a material change in the target asset allocation and/or significant changes in fees and expenses paid by the Discover Pension Plan.
	The following table presents assumed health care cost trend rates used to determine the postretirement benefit obligations:
		31-Dec-13			31-Dec-12
	Health care cost trend rate assumed for next year:
	Medical	6.90%-7.30%			6.90%-7.40%
	Prescription	6.90%-7.30%			8.4	%
	Rate to which the cost trend rate is assumed to decline (ultimate trend rate)	5	%		5	%
	Year that the rate reaches the ultimate trend rate	2027			2027
	Pension Plan Assets
	The targeted asset allocation for 2014 by asset class is 45% and 55% for equity securities and fixed income securities, respectively. The Discover Financial Services Retirement Plan Investment Committee (the “Investment Committee”) determined the asset allocation targets for the Pension Plan based on its assessment of business and financial conditions, demographic and actuarial data, funding characteristics and related risk factors. Other relevant factors, including industry practices and long-term historical and prospective capital market returns were considered as well.
	The Discover Pension Plan return objectives provide long-term measures for monitoring the investment performance against growth in the pension obligations. The overall allocation is expected to help protect the Discover Pension Plan's funded status while generating sufficiently stable real returns (net of inflation) to help cover current and future benefit payments and to improve the Discover Pension Plan's funded status. Total Discover Pension Plan portfolio performance is assessed by comparing actual returns with relevant benchmarks, such as the Standard & Poor's (“S&P”) 500 Index, the S&P 500 Total Return Index, the Russell 2000 Index and the MSCI All Country World Index.
Both the equity and fixed income portions of the asset allocation use a combination of active and passive investment strategies and different investment styles. The fixed income asset allocation consists of longer duration fixed income securities in order to help reduce plan exposure to interest rate variation and to better correlate assets with obligations. The longer duration fixed income allocation is expected to help stabilize the funding status ratio over the long term.
The asset mix of the Discover Pension Plan is reviewed by the Investment Committee on a regular basis. The asset allocation strategy will change over time in response to changes in the Pension Plan's funded status.
Fair Value Measurements
The Discover Pension Plan’s assets are stated at fair value. Quoted market prices in active markets are the best evidence of fair value and are used as the basis for the measurement, if available. If a quoted market price is not available, the estimate of the fair value is based on the best information available in the circumstances. The table below presents information about the Discover Pension Plan assets and indicates the level within the fair value hierarchy, as defined by ASC 820, with which each item is associated. For a description of the fair value hierarchy, see Note 21: Fair Value Measurements and Disclosures. (dollars in millions):
	31-Dec-13
	Level 1				Level 2				Level 3			Total				Net Asset Allocation
Assets
Registered Investment Company
Domestic small/mid cap equity fund	$	—			$	32			$	—		$	32			9	%
Emerging markets equity fund	—				29				—			29				8
Global low volatility equity fund	—				19				—			19				5
International core equity fund	—				46				—			46				13
Common Collective Trusts:
Domestic large cap equity fund	—				50				—			50				13
Domestic fixed income fund	—				7				—			7				2
Long duration fixed income fund	—				181				—			181				49
Temporary investment fund	—				3				—			3				1	%
Total assets	$	—			$	367			$	—		$	367			100	%
	31-Dec-12
	Level 1				Level 2				Level 3			Total				Net Asset Allocation
Assets
Fixed income securities - U.S. treasuries	$	47			$	—			$	—		$	47			13	%
Fixed income securities - corporate debt	—				151				—			151				41
Registered Investment Company:
International equity fund	24				—				—			24				6
Common Collective Trusts:
International equity fund	—				63				—			63				17
Domestic large cap equity fund	—				68				—			68				19
Domestic small cap equity fund	—				11				—			11				3
Temporary investment fund	—				4				—			4				1
Total assets	$	71			$	297			$	—		$	368			100	%
The investments that are categorized as Level 2 assets primarily consist of fixed income securities and common collective trusts. The common collective trust investment vehicles are valued using the Net Asset Value (“NAV”) provided by the administrator of the fund. The NAV is quoted on a private market that is not active; however, the unit price is based on underlying investments that are traded on an active market. The fair value of the stable value product is calculated as the present value of future cash flows.
There were no transfers between Levels 1 and 2 within the fair value hierarchy for the calendar year ended December 31, 2013, fiscal year ended November 30, 2012 and one month ended December 31, 2012.
Cash Flows
The Company does not expect to make any contributions to its postretirement benefit plans for 2014.
Expected benefit payments associated with the Company’s pension and postretirement benefit plans for the next five years and in aggregate for the years thereafter are as follows (dollars in millions):
	Pension				Postretirement
2014	$	12			$	1
2015	$	13			$	1
2016	$	13			$	1
2017	$	14			$	1
2018	$	15			$	1
Following five years thereafter	$	94			$	6
Discover 401(k) Plan
Under the Discover 401(k) Plan, eligible U.S. employees of the Company receive 401(k) matching contributions. Effective January 1, 2009, eligible employees also receive fixed employer contributions and, if eligible, employer transition credit contributions. The pretax expense associated with the 401(k) matching, fixed employer and transition credit contributions for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012 was $50 million, $42 million, $38 million and $3 million respectively.

Common_and_Preferred_Stock

Common and Preferred Stock	12 Months Ended
	Dec. 31, 2013
Class of Stock Disclosures [Abstract]	'
Common and Preferred Stock	'
	Common and Preferred Stock
	Preferred Stock
	The Company has 575,000 shares of Fixed Rate Non-Cumulative Perpetual Preferred Stock, Series B (the "preferred stock"), outstanding with a par value of $0.01 per share that were issued on October 16, 2012. Each share of preferred stock has a liquidation preference of $1,000 and is represented by 40 depositary shares. Net proceeds received from the preferred stock issuance totaled approximately $560 million. The preferred stock is redeemable at the Company's option, subject to regulatory approval, either (1) in whole or in part on any dividend payment date on or after December 1, 2017 or (2) in whole but not in part, at any time within 90 days following a regulatory capital event (as defined in the certificate of designations for the preferred stock), in each case at a redemption price equal to $1,000 per share of preferred stock plus declared and unpaid dividends. Any dividends declared on the preferred stock will be payable quarterly in arrears at a rate of 6.50% per annum.
	Stock Repurchase Program
	On March 14, 2013, the Company's board of directors approved a share repurchase program authorizing the repurchase of up to $2.4 billion of its outstanding shares of common stock. The program expires on March 31, 2015, and may be terminated at any time. During the calendar year ended December 31, 2013, the Company repurchased 27,034,355 shares for $1.3 billion.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2013
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, Net of Tax			Gain (Loss) on Cash Flow Hedges, Net of Tax			Foreign Currency Translation Adjustments, Net of Tax(4)			Pension and Post Retirement Plan Gain (Loss), Net of Tax			Accumulated Other Comprehensive Income (Loss)
	Balance at November 30, 2010	$	8		$	2		$	—		$	(93	)	$	(83	)
	Net unrealized gains on investment securities, net of tax expense of $28(1)	47			—			—			—			47
	Unrealized gains on cash flow hedges, net of tax expense of $3(2)	—			5			—			—			5
	Unrealized pension and postretirement plan loss, net of tax benefit of $12(3)	—			—			—			(21		)	(21		)
	Balance at November 30, 2011	55			7			—			(114		)	(52		)
	Net unrealized gains on investment securities, net of tax expense of $11(1)	19			—			—			—			19
	Unrealized losses on cash flow hedges, net of tax benefit of $2(2)	—			(4		)	—			—			(4		)
	Unrealized pension and postretirement plan loss, net of tax benefit of $25(3)	—			—			—			(38		)	(38		)
	Balance at November 30, 2012	74			3			—			(152		)	(75		)
	Net unrealized losses on investment securities, net of tax benefit of $2(1)	(3		)	—			—			—			(3		)
	Unrealized pension and postretirement plan gain, net of tax expense of $4(3)	—			—			—			6			6
	Balance at December 31, 2012	71			3			—			(146		)	(72		)
	Net change(5)	(52		)	10			1			45			4
	Balance at December 31, 2013	$	19		$	13		$	1		$	(101	)	$	(68	)
	-1	Represents the difference between the fair value and amortized cost of available-for-sale investment securities.
	-2	Represents unrealized gains (losses) related to effective portion of cash flow hedges.
	-3	Reflects adjustments to the funded status of pension and postretirement plans, which is the difference between the fair value of the plan assets and the projected benefit obligation.
	-4	Includes unrealized losses on hedge of net investment in foreign subsidiary, net of tax benefit and net gains on foreign currency translation adjustments.
	-5	In February 2013, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. ASU 2013-02 requires an entity to report the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in the consolidated statements of income if the amount being reclassified is required to be reclassified in its entirety to net income. For amounts that are not required to be reclassified to net income in their entirety in the same reporting period, an entity is required to cross-reference other disclosures that provide additional detail about those amounts. As the result, the Company has adjusted its AOCI presentation prospectively, as required, and therefore additional table was included to present the required information for the current period and the presentation has changed from historical periods.
	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):
		For the Calendar Year Ended December 31, 2013
		Before Tax			Tax (Expense) Benefit			Net of Tax
	Available-for-Sale Investment Securities:
	Net unrealized holding losses arising during the period	$	(80	)	$	30		$	(50	)
	Amounts reclassified from accumulated other comprehensive income	(2		)	—			(2		)
	Net change	$	(82	)	$	30		$	(52	)
	Cash Flow Hedges:
	Net unrealized gains arising during the period	$	8		$	(3	)	$	5
	Amounts reclassified from accumulated other comprehensive income	8			(3		)	5
	Net change	$	16		$	(6	)	$	10
	Foreign Currency Translation Adjustments:
	Net unrealized gains arising during the period	$	1		$	—		$	1
	Net change	$	1		$	—		$	1
	Pension and Postretirement Plan:
	Unrealized gains arising during the period	$	72		$	(27	)	$	45
	Net change	$	72		$	(27	)	$	45

Other_Income_and_Other_Expense

Other Income and Other Expense	12 Months Ended
	Dec. 31, 2013
Other Income and Expenses [Abstract]	'
Other Income and Other Expense	'
	Other Income and Other Expense
	Total other income includes the following components (dollars in millions):
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,				For the One Month Ended December 31, 2012
					2012		2011
	Royalty and licensee revenue	$	68		$	72	$	72	$	6
	Merchant fees	44			17		16		3
	Transition service agreement revenue	6			12		27		1
	Gain from sales of merchant contracts	—			3		11		—
	Other income	51			59		53		9
	Total other income	$	169		$	163	$	179	$	19
	Total other expense includes the following components (dollars in millions):
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,				For the One Month Ended December 31, 2012
					2012		2011
	Postage	$	86		$	85	$	82	$	7
	Fraud losses	110			93		72		9
	Supplies	26			22		23		2
	Credit related inquiry fees	19			20		17		1
	Litigation expense	(12		)	218		22		—
	Incentive expense	61			59		23		5
	Other expense	198			107		101		11
	Total other expense	$	488		$	604	$	340	$	35

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	Income tax expense consisted of the following (dollars in millions):
		For the Calendar Year Ended December 31, 2013				For the Fiscal Years Ended November 30,							For the One Month Ended December 31, 2012
						2012				2011
	Current:
	U.S. federal	$	1,059			$	1,109			$	931		$	101
	U.S. state and local	87				149				118			15
	International	6				4				3			—
	Total	1,152				1,262				1,052			116
	Deferred:
	U.S. federal	295				136				228			(11		)
	U.S. state and local	27				10				4			(1		)
	Total	322				146				232			(12		)
	Income tax expense	$	1,474			$	1,408			$	1,284		$	104
	The following table reconciles the Company’s effective tax rate to the U.S. federal statutory income tax rate:
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011
	U.S. federal statutory income tax rate	35	%		35	%		35	%		35	%
	U.S. state, local and other income taxes, net of U.S. federal income tax benefits	2.2			2.9			2.4			3.2
	Valuation allowance - capital loss	—			—			(0.6	)		—
	Other	0.2			(0.4	)		(0.2	)		(0.1	)
	Effective income tax rate	37.4	%		37.5	%		36.6	%		38.1	%
	Deferred income taxes reflect the net tax effects of temporary differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when such differences are expected to reverse. Valuation allowances are provided to reduce deferred tax assets to an amount that is more likely than not to be realized. The Company evaluates the likelihood of realizing its deferred tax assets by estimating sources of future taxable income and the impact of tax planning strategies. Significant components of the Company’s net deferred income taxes, which are included in other assets in the consolidated statements of financial condition, were as follows (dollars in millions):
		December 31,
		2013				2012
	Deferred tax assets:
	Allowance for loan losses	$	627			$	673
	Customer fees and rewards	212				372
	Compensation and benefits	87				104
	State income taxes	65				71
	Legal reserves	13				83
	Other	59				37
	Total deferred tax assets before valuation allowance	1,063				1,340
	Valuation allowance	(37		)		—
	Total deferred tax assets, net of valuation allowance	1,026				1,340
	Deferred tax liabilities:
	Debt exchange premium	(98		)		(107		)
	Depreciation and software amortization	(83		)		(60		)
	Unearned income	(40		)		(38		)
	Intangibles	(22		)		(22		)
	Deferred loan acquisition costs	(16		)		(12		)
	Unrealized gain/ loss	(8		)		(15		)
	Other	(5		)		(11		)
	Total deferred tax liabilities	(272		)		(265		)
	Net deferred tax assets	$	754			$	1,075
	Deferred tax assets at December 31, 2013 included a valuation allowance of $37 million established primarily on Diner's Club Italy deferred taxes.
	A reconciliation of beginning and ending unrecognized tax benefits is as follows (dollars in millions):
		For the Calendar Year Ended December 31, 2013				For the Fiscal Years Ended November 30,							For the One Month Ended December 31, 2012
						2012				2011
	Balance at beginning of period	$	575			$	507			$	373		$	573
	Additions:
	Current year tax positions	1				74				74			2
	Prior year tax positions	142				1				154			—
	Reductions:
	Prior year tax positions	(69		)		(5		)		(83		)	—
	Settlements with taxing authorities	(18		)		(2		)		(9		)	—
	Expired statute of limitations	(2		)		(2		)		(2		)	—
	Balance at end of period(1)	$	629			$	573			$	507		$	575
	-1	At December 31, 2013, November 30, 2012 and 2011 and December 31, 2012, amounts included $142 million, $108 million, $97 million and $109 million respectively, of unrecognized tax benefits, which, if recognized, would favorably affect the effective tax rate.
	The Company recognizes accrued interest and penalties related to unrecognized tax benefits as a component of income tax expense. Interest and penalties related to unrecognized tax benefits increased by $17 million to $118 million for the calendar year ended December 31, 2013, increased by $20 million to $99 million for the fiscal year ended November 30, 2012, increased by $11 million to $79 million for the fiscal year ended November 30, 2011 and increased by $2 million to $101 million for the one month ended December 31, 2012. The changes primarily relate to the revaluation of existing federal and state tax issues.
	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, the outcome of which remains uncertain, of the IRS’s proposed assessment for the years 1999 through 2005, when Discover was a subsidiary of Morgan Stanley. Although the appeals process is taking longer than anticipated, 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 $101 million could be recognized as a result of such settlement.
	The IRS is currently examining 2006 through June 20, 2007, which is approximately the date that Discover spun off from Morgan Stanley. 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.
	At December 31, 2013, the Company had net operating loss carryforwards of $89 million for foreign purposes which do not expire.

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2013
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 Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011
	Numerator:
	Net income	$	2,470		$	2,345		$	2,227		$	170
	Preferred stock dividends	(37		)	(5		)	—			—
	Net income available to common stockholders	2,433			2,340			2,227			170
	Income allocated to participating securities	(19		)	(22		)	(25		)	(2		)
	Net income allocated to common stockholders	$	2,414		$	2,318		$	2,202		$	168
	Denominator:
	Weighted average shares of common stock outstanding	485			519			542			498
	Effect of dilutive common stock equivalents	2			1			1			1
	Weighted average shares of common stock outstanding and common stock equivalents	487			520			543			499
	Basic earnings per common share	$	4.97		$	4.47		$	4.06		$	0.34
	Diluted earnings per common share	$	4.96		$	4.46		$	4.06		$	0.34
	Anti-dilutive securities were not material and had no impact on the computation of diluted EPS for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, respectively.

Capital_Adequacy

Capital Adequacy	12 Months Ended
	Dec. 31, 2013
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 December 31, 2013, 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 December 31, 2013, 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 as of December 31, 2013 and 2012 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
	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%
	December 31, 2012
	Total capital (to risk-weighted assets)
	Discover Financial Services	$	10,998	16.8	%	$	5,242	≥8.0%	$	6,552	≥10.0%
	Discover Bank	$	9,615	14.9	%	$	5,172	≥8.0%	$	6,465	≥10.0%
	Tier 1 capital (to risk-weighted assets)
	Discover Financial Services	$	9,470	14.5	%	$	2,621	≥4.0%	$	3,931	≥6.0%
	Discover Bank	$	8,097	12.5	%	$	2,586	≥4.0%	$	3,879	≥6.0%
	Tier 1 capital (to average assets)
	Discover Financial Services	$	9,470	12.7	%	$	2,987	≥4.0%	$	3,734	≥5.0%
	Discover Bank	$	8,097	11	%	$	2,936	≥4.0%	$	3,670	≥5.0%
	The amount of dividends that a bank may pay in any year is subject to certain regulatory restrictions. Under the current banking regulations, a bank may not pay dividends if such a payment would leave the bank inadequately capitalized. In the calendar year ended December 31, 2013 and fiscal years ended November 30, 2012 and 2011, Discover Bank paid dividends of $1.6 billion, $1.5 billion and $1.4 billion, respectively, to the Company. No dividends were paid by Discover Bank during the one month ended December 31, 2012.

Commitments_Contingencies_and_

Commitments, Contingencies and Guarantees	12 Months Ended
	Dec. 31, 2013
Commitments Contingencies and Guarantees [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 2022. At December 31, 2013, 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	$	1	$	15
	2015	—		11
	2016	—		10
	2017	—		9
	2018	—		6
	Thereafter	—		7
	Total minimum lease payments	1		$	58
	Less: Amount representing interest	—
	Present value of net minimum lease payments	$	1
	Occupancy lease agreements, in addition to base rentals, generally provide for rent and operating expense escalations resulting from increased assessments for real estate taxes and other charges. Total rent expense under operating lease agreements, which considers contractual escalations, was $15 million, $18 million, $16 million and $3 million for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, respectively.
	Unused Commitments to Extend Credit
	At December 31, 2013, the Company had unused commitments to extend credit for loans of approximately $162.8 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 statements of financial condition. The Company has not recorded any incremental contingent liability associated with its secured borrowing representations and warranties. Management believes that the probability of having to replace, repurchase or sell assets pledged as collateral under secured borrowing arrangements, including an early amortization event, is low.
	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 December 31, 2013, this amount was not material and was included in accrued expenses and other liabilities on the 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):
		December 31,
		2013
	Diners Club:
	Merchant guarantee	$	144
	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 December 31, 2013, the Company had not recorded any contingent liability in the 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 December 31, 2013, the Company had not recorded any contingent liability in the 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 calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012.
	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 Calendar Year Ended December 31, 2013		For the Fiscal Years Ended November 30,				For the One Month Ended December 31, 2012
				2012		2011
	Aggregate sales transaction volume(1)	$	120,442	$	114,847	$	108,225	$	11,521
	-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 consolidated financial statements for merchant chargeback guarantees on December 31, 2013 and 2012. 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 consolidated statements of financial condition (dollars in millions):
		December 31,
		2013		2012
	Settlement withholdings and escrow deposits	$	17	$	25

Litigation_and_Regulatory_Matt

Litigation and Regulatory Matters	12 Months Ended
	Dec. 31, 2013
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-related expense of $218 million and $22 million was recognized for the fiscal years ended November 30, 2012 and 2011, respectively. Litigation expense was not material for the calendar year ended December 31, 2013 and one month ended December 31, 2012.
	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 $150 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 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.
	On August 16, 2011, the Attorney General of West Virginia filed a lawsuit against the Company in the Circuit Court of Mason County, West Virginia (West Virginia v. Discover Financial Services, Inc., Discover Bank, DFS Services LLC et al.). The lawsuit asserts various claims related to the Company's marketing and administration of various protection products under West Virginia law. The Company has resolved this matter with the Attorney General.
	On August 26, 2011, the Attorney General of Missouri issued a request for information to the Company in connection with an investigation to determine whether the Company has engaged in conduct that violates Missouri law in the marketing of its payment protection product to its credit card customers. The Company has resolved this matter with the Attorney General.
	There are two class action cases pending 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. The settlement remains subject to final approval by the court.
	On April 12, 2012, the Attorney General of Hawaii filed a lawsuit against the Company in the Circuit Court of the First Circuit, Hawaii (Hawaii v. Discover Financial Services, Inc., Discover Bank, DFS Services LLC et al.). The lawsuit asserts various claims related to the Company's marketing and administration of various protection products under Hawaii law. The Company has resolved this matter with the Attorney General.
	On June 28, 2012, the Attorney General of Mississippi filed a lawsuit against the Company in the Chancery Court of the First Judicial District of Hinds County, Mississippi (Mississippi v. Discover Financial Services, Inc., Discover Bank, DFS Services LLC et al.). The lawsuit asserts various claims related to the Company's marketing and administration of various protection products under Mississippi law. The Company has resolved this matter with the Attorney General.
	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.
	On April 17, 2013, the Attorney General of New Mexico filed a lawsuit against the Company in the First Judicial District Court, County of Santa Fe, New Mexico (New Mexico v. Discover Financial Services, Inc., Discover Bank, DFS Services LLC et al.). The lawsuit asserts various claims related to the Company's marketing and administration of various protection products under New Mexico law. The Company has resolved this matter with the Attorney General.

Fair_Value_Measurements_and_Di

Fair Value Measurements and Disclosures	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value 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 calendar year ended December 31, 2013, there were no changes to the Company's valuation techniques that had, or are expected to have, a material impact on the Company's 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 Active Markets		Significant Other Observable Inputs				Significant Unobservable Inputs				Total
		for Identical Assets		(Level 2)				(Level 3)
		(Level 1)
	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
	Balance at December 31, 2012
	Assets
	U.S. Treasury securities	$	2,459	$	—			$	—			$	2,459
	U.S. government agency securities	2,233		—				—				2,233
	Credit card asset-backed securities of other issuers	—		151				—				151
	Residential mortgage-backed securities - Agency	—		1,302				—				1,302
	Available-for-sale investment securities	$	4,692	$	1,453			$	—			$	6,145
	Mortgage loans held for sale	$	—	$	355			$	—			$	355
	Interest rate lock commitments	$	—	$	—			$	12			$	12
	Forward delivery contracts	—		1				—				1
	Other derivative financial instruments	—		98				—				98
	Derivative financial instruments	$	—	$	99			$	12			$	111
	Liabilities
	Forward delivery contracts	$	—	$	2			$	—			$	2
	Other derivative financial instruments	—		1				—				1
	Derivative financial instruments	$	—	$	3			$	—			$	3
	There were no transfers between Levels 1 and 2 within the fair value hierarchy for the calendar year ended December 31, 2013, fiscal year ended November 30, 2012 and one month ended December 31, 2012.
	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 December 31, 2013, 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 $1.3 billion, a weighted-average coupon of 2.83% 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 December 31, 2013 and 2012, the aggregate unpaid principal balance of loans held for sale for which the fair value option had been elected was $146 million and $337 million, respectively. At December 31, 2013 and 2012, the same loans had a fair value of $148 million and $355 million, respectively. For the calendar year ended December 31, 2013 and one month ended December 31, 2012, $37 million of losses and $1 million of gains, respectively, from fair value adjustments on mortgage loans held for sale were recorded in other revenue on the 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). There were no Level 3 assets or liabilities measured at fair value on a recurring basis at any point during the fiscal year ended November 30, 2011.
For the Calendar Year Ended December 31, 2013
	Balance at December 31, 2012		Transfers into			Transfers out of Level 3			Total net gains (losses) included in earnings			Purchases			Sales		Settlements		Transfers of IRLCs to closed loans		Balance at December 31, 2013
			Level 3
Interest rate lock commitments	$	12	—			—			121			—			—		3		(132	)	$	4
Forward delivery contracts	$	—	—			(3	)		3			—			—		—		—		$	—
Mortgage loans held for sale	$	—	3			—			—			1			(3	)	(1	)	—		$	—
For the Fiscal Year Ended November 30, 2012
	Balance at November 30, 2011		Transfers into			Transfers out of Level 3			Total net gains (losses) included in earnings			Purchases			Sales		Settlements		Transfers of IRLCs to closed loans		Balance at November 30, 2012
			Level 3
Interest rate lock commitments	$	—	—			—			110			5			—		2		(102	)	$	15
Forward delivery contracts	$	—	—			(1	)		1			—			—		—		—		$	—
For the One Month Ended December 31, 2012
	Balance at November 30, 2012		Transfers into			Transfers out of Level 3			Total net gains (losses) included in earnings			Purchases			Sales		Settlements		Transfers of IRLCs to closed loans		Balance at December 31, 2012
			Level 3
Interest rate lock commitments	$	15	—			—			17			—			—		1		(21	)	$	12
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 as of December 31, 2013 (dollars in millions):
	Fair Value		Valuation		Significant Unobservable Input		Ranges of Inputs						Weighted Average(1)
			Technique				Low			High
Interest rate lock commitments	$	4	Quantitative risk models		Loan funding probability		15	%		100	%		60	%
-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 calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, 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, as of December 31, 2013 and 2012 (dollars in millions):
	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs (Level 2)				Significant Unobservable Inputs (Level 3)				Total				Carrying Value
	(Level 1)
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
Balance at December 31, 2012
Assets
U.S. Treasury securities	$	1	$	—			$	—			$	1			$	1
States and political subdivisions of states	—		34				—				34				34
Residential mortgage-backed securities - Agency	—		54				—				54				52
Held-to-maturity investment securities	$	1	$	88			$	—			$	89			$	87
Cash and cash equivalents	$	2,584	$	—			$	—			$	2,584			$	2,584
Restricted cash	$	290	$	—			$	—			$	290			$	290
Net loan receivables(1)	$	—	$	—			$	62,619			$	62,619			$	60,455
Accrued interest receivables	$	—	$	500			$	—			$	500			$	500
Liabilities
Deposits	$	—	$	42,671			$	—			$	42,671			$	42,213
Short-term borrowings	$	—	$	327			$	—			$	327			$	327
Long-term borrowings - owed to securitization investors	$	—	$	14,033			$	2,337			$	16,370			$	15,933
Other long-term borrowings	$	—	$	2,332			$	2			$	2,334			$	1,733
Accrued interest payables	$	—	$	126			$	—			$	126			$	126
-1	Net loan receivables excludes 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 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 statements 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 10: 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 statements 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	12 Months Ended
	Dec. 31, 2013
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.
	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, beginning in 2013, 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 December 31, 2013. 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 December 31, 2013 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 $23 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 calendar year ended December 31, 2013, 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 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.
	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 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.
	The following table summarizes the fair value (including accrued interest) and related outstanding notional amounts of derivative instruments and indicates where within the statements of financial condition each is reported as of December 31, 2013 and 2012 (dollars in millions). See Note 21: Fair Value Measurements and Disclosures for a description of the valuation methodologies of derivatives. 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. Total derivative assets 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 statements of financial condition. Collateral amounts recorded in the condensed consolidated statements 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.
		December 31, 2013														December 31, 2012
								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 Expenses and Other Liabilities (At Fair Value)
		Amount				Transactions		Assets								Amount		Assets
								(At Fair										(At Fair
								Value)										Value)
	Derivatives designated as hedges:
	Interest rate swaps - cash flow hedge	$	2,650			5		$	18			$	—			$	1,750	$	5		$	—
	Interest rate swaps - fair value hedge	$	7,138			244		52				6				$	7,859	93			—
	Foreign exchange forward contract - net investment hedge(1)	$	35			1		—				—				$	—	—			—
	Derivatives not designated as hedges:
	Foreign exchange forward contracts(2)	$	44			8		—				—				$	40	—			—
	Interest rate swap(3)	$	796			1		—				—				$	1,027	—			1
	Forward delivery contracts	$	693			478		5				1				$	774	1			2
	Interest rate lock commitments(3)	$	235			1,107		4				—				$	414	12			—
	Total gross derivative assets/liabilities(4)							79				7						111			3
	Less: Collateral receivable/payable(5)							(61		)		(7		)				(92		)	—
	Total net derivative assets/liabilities							$	18			$	—					$	19		$	3
	-1	The foreign exchange forward contract has a notional amounts of EUR 26 million as of December 31, 2013.
	-2	The foreign exchange forward contracts have notional amounts of EUR 20 million, GBP 6 million, SGD 1 million and CHF 5 million as of December 31, 2013 and EUR 18 million and GBP 9 million and SGD 2 million as of December 31, 2012.
	-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 $40 million and an immaterial fair value as of December 31, 2013.
	-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 calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012 (dollars in millions):
				For the Calendar Year Ended December 31, 2013(1)			For the Fiscal Years Ended November 30,								For the One Month Ended December 31, 2012
		Location					2012				2011
	Derivatives designated as hedges:
	Interest rate swaps—cash flow hedges:
	Total gains (losses) recognized in other comprehensive income after amounts reclassified into earnings, pre-tax	Other  Comprehensive Income		$	13		$	(6	)		$	7			$	(1	)
	Total gains (losses) recognized in other comprehensive income			$	13		$	(6	)		$	7			$	(1	)
	Amount reclassified from other comprehensive income into income	Interest Income		$	4		$	7			$	8			$	1
	Amount reclassified from other comprehensive income into income	Interest Expense		(12		)	—				—				—
	Interest rate swaps—fair value hedges:
	Interest expense - ineffectiveness			(46		)	58				37				(9		)
	Interest expense - other			41			30				13				3
	Gain (loss) on interest rate swaps	Interest Expense		(5		)	88				50				(6		)
	Interest expense - ineffectiveness			51			(52		)		(30		)		10
	Interest expense - other			(6		)	(6		)		(7		)		(1		)
	Gain (loss) on hedged item	Interest Expense		45			(58		)		(37		)		9
	Total gains (losses) recognized in income			$	32		$	37			$	21			$	4
	Derivatives not designated as hedges:
Gain (loss) on forward contracts	Other Income		$	(1	)	$	1			$	—			$	(1	)
Gain (loss) on interest rate swaps	Other Income		(1		)	(7		)		(5		)		—
Gain (loss) on forward delivery contracts	Other Income		4			(1		)		—				2
Gain (loss) on interest rate lock commitments	Other Income		121			110				—				17
Total gains (losses) on derivatives not designated as hedges recognized in income			$	123		$	103			$	(5	)		$	18
-1	The impact of the net investment hedge on the consolidated statements of income, which arise from amounts reclassified from other comprehensive income, was immaterial for the calendar year ended December 31, 2013.
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 December 31, 2013, 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 December 31, 2013, 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 $103 million as of December 31, 2013.
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	12 Months Ended
	Dec. 31, 2013
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 calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012 (dollars in millions):
		Direct		Payment		Total
		Banking		Services
	For the Calendar Year Ended December 31, 2013
	Interest income
	Credit card	$	5,978	$	—	$	5,978
	Private student loans	252		—		252
	PCI student loans	272		—		272
	Personal loans	464		—		464
	Other	98		—		98
	Total interest income	7,064		—		7,064
	Interest expense	1,146		—		1,146
	Net interest income	5,918		—		5,918
	Provision for loan losses	1,069		17		1,086
	Other income	1,976		330		2,306
	Other expense	2,961		233		3,194
	Income before income tax expense	$	3,864	$	80	$	3,944
	For the Fiscal Year Ended November 30, 2012
	Interest income
	Credit card	$	5,751	$	—	$	5,751
	Private student loans	184		—		184
	PCI student loans	303		—		303
	Personal loans	363		—		363
	Other	102		—		102
	Total interest income	6,703		—		6,703
	Interest expense	1,331		—		1,331
	Net interest income	5,372		—		5,372
	Provision for loan losses	848		—		848
	Other income	1,939		342		2,281
	Other expense	2,891		161		3,052
	Income before income tax expense	$	3,572	$	181	$	3,753
	For the Fiscal Year Ended November 30, 2011
	Interest income
	Credit card	$	5,654	$	—	$	5,654
	Private student loans	115		—		115
	PCI student loans	225		—		225
	Personal loans	266		—		266
	Other	85		—		85
	Total interest income	6,345		—		6,345
	Interest expense	1,485		—		1,485
	Net interest income	4,860		—		4,860
	Provision for loan losses	1,013		—		1,013
	Other income	1,907		298		2,205
	Other expense	2,409		132		2,541
	Income before income tax expense	$	3,345	$	166	$	3,511
	For the One Month Ended December 31, 2012
	Interest income
	Credit card	$	510	$	—	$	510
	Private student loans	18		—		18
	PCI student loans	24		—		24
	Personal loans	34		—		34
	Other	9		—		9
Total interest income	595		—		595
Interest expense	103		—		103
Net interest income	492		—		492
Provision for loan losses	178		—		178
Other income	169		31		200
Other expense	224		16		240
Income before income tax expense	$	259	$	15	$	274

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2013
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	Related Party Transactions
	In the ordinary course of business, the Company offers consumer loan products to its directors, executive officers and certain members of their families. These products are offered on substantially the same terms as those prevailing at the time for comparable transactions with unrelated parties, and these receivables are included in the loan receivables in the Company's consolidated statements of financial condition. They were not material to the Company's financial position or results of operations.

Parent_Company_Condensed_Finan

Parent Company Condensed Financial Information	12 Months Ended
	Dec. 31, 2013
Condensed Financial Information of Parent Company Only Disclosure [Abstract]	'
Parent Company Condensed Financial Information	'
	Parent Company Condensed Financial Information
	The following Parent Company financial statements are provided in accordance with SEC rules, which require such disclosure when the restricted net assets of consolidated subsidiaries exceed 25 percent of consolidated net assets.
	Discover Financial Services
	(Parent Company Only)
	Condensed Statements of Financial Condition
		December 31,
		2013			2012
		(dollars in millions)
	Assets:
	Cash and cash equivalents	$	4		$	41
	Notes receivable from subsidiaries(1)	2,254			2,225
	Investments in subsidiaries	9,824			8,947
	Other assets	158			133
	Total assets	$	12,240		$	11,346
	Liabilities and Stockholders' Equity:
	Non-interest bearing deposit accounts	$	6		$	3
	Interest-bearing deposit accounts	7			17
	Total deposits	13			20
	Short-term borrowings from subsidiaries	146			88
	Other long-term borrowings(2)	1,045			1,035
	Accrued expenses and other liabilities	227			330
	Total liabilities	1,431			1,473
	Stockholders' equity	10,809			9,873
	Total liabilities and stockholders' equity	$	12,240		$	11,346
	-1	The Parent Company advanced $1.8 billion to Discover Bank as of December 31, 2013, which is included in notes receivables from subsidiaries. The $1.8 billion is available to the Parent for liquidity purposes.
	-2	During the 2012 fiscal year, the Company completed a private exchange offer, resulting in the exchange of $500 million outstanding aggregate principal amount of subordinated debt issued by a subsidiary for the same aggregate principal amount of new senior notes issued by the Parent. A cash premium of $176 million paid by the subsidiary to bondholders tendering its subordinated notes under the exchange offer is reported as a component of the new senior notes and is thus included in other long term borrowings of the Parent.
	Discover Financial Services
	(Parent Company Only)
	Condensed Statements of Income
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011
		(dollars in millions)
	Interest income	$	22		$	22		$	23		$	2
	Interest expense	84			52			61			7
	Net interest expense	(62		)	(30		)	(38		)	(5		)
	Dividends from subsidiaries	1,600			1,500			1,375			—
	Other income	—			—			3			—
	Total income (loss)	1,538			1,470			1,340			(5		)
	Other expense
	Employee compensation and benefits	—			—			2			—
	Professional fees	3			1			—			—
	Other(1)	1			(171		)	2			—
	Total other (benefit) expense	4			(170		)	4			—
	Income (loss) before income tax (expense) benefit and equity in undistributed net income of subsidiaries	1,534			1,640			1,336			(5		)
	Income tax (expense) benefit	17			(54		)	16			2
	Equity in undistributed net income of subsidiaries	919			759			875			173
	Net income	$	2,470		$	2,345		$	2,227		$	170
	-1	During the 2012 fiscal year, the Company completed a private exchange offer, resulting in the exchange of $500 million outstanding aggregate principal amount of subordinated debt issued by a subsidiary for the same aggregate principal amount of new senior notes issued by the Parent. A cash premium of $176 million was paid by the subsidiary but is associated with the borrowings on the Parent financial statements.
	Discover Financial Services
	(Parent Company Only)
	Condensed Statements of Cash Flows
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011
		(dollars in millions)
	Cash flows from operating activities
	Net income	$	2,470		$	2,345		$	2,227		$	170
	Adjustments to reconcile net income to net cash provided by operating activities:
	Non-cash charges included in net income:
	Equity in undistributed net income of subsidiaries	(919		)	(759		)	(875		)	(173		)
	Stock-based compensation expense	59			47			44			3
	Deferred income taxes	(2		)	109			18			(1		)
	Premium on debt issuance(1)	—			(176		)	—			—
	Depreciation and amortization	19			4			—			1
Changes in assets and liabilities:
(Increase) decrease in other assets	(33		)	(16		)	(8		)	32
Increase (decrease) in other liabilities and accrued expenses	29			10			(16		)	(15		)
Net cash provided by operating activities	1,623			1,564			1,390			17
Cash flows from investing activities
Increase in investment in subsidiaries	—			(196		)	(8		)	(1		)
(Increase) decrease in loans to subsidiaries	(29		)	(520		)	(877		)	57
Net cash (used for) provided by investing activities	(29		)	(716		)	(885		)	56
Cash flows from financing activities
Net increase (decrease) in short-term borrowings from subsidiaries	58			1			—			(6		)
Proceeds from issuance of common stock	13			26			23			2
Proceeds from issuance of preferred stock	—			560			—			—
Proceeds from advances from subsidiaries	—			93			—			—
Purchases of treasury stock	(1,296		)	(1,216		)	(436		)	(12		)
Net (decrease) increase in deposits	(7		)	12			18			(12		)
Premium paid on debt exchange	—			(115		)	—			—
Dividends paid on common and preferred stock	(399		)	(209		)	(110		)	(5		)
Net cash used for financing activities	(1,631		)	(848		)	(505		)	(33		)
Increase (decrease) in cash and cash equivalents	(37		)	—			—			40
Cash and cash equivalents, at beginning of period	41			1			1			1
Cash and cash equivalents, at end of period	$	4		$	1		$	1		$	41
Supplemental Disclosures:
Cash paid during the year for:
Interest expense	$	65		$	66		$	77		$	2
Income taxes, net of income tax refunds	$	(1	)	$	(65	)	$	11		$	—
Significant non-cash investing and financing transactions
Capital contribution to subsidiary(1)	$	—		$	499		$	—		$	—
Debt issuance, net of discount(1)	$	—		$	(499	)	$	—		$	—
-1	During the 2012 fiscal year, the Company completed a private exchange offer, resulting in the exchange of $500 million outstanding aggregate principal amount of subordinated debt issued by a subsidiary for the same aggregate principal amount of new senior notes issued by the Parent. A cash premium of $176 million was paid by the subsidiary but is associated with the borrowings on the Parent financial statements.

Transition_Period_Financial_In

Transition Period Financial Information Transition Period Financial Information	12 Months Ended
	Dec. 31, 2013
Transition Period Financial Information [Abstract]	'
Transition Period Financial Information	'
	Transition Period Financial Information
	The following table presents selected financial data for the one month ended and as of December 31, 2012 and the one month ended and as of December 31, 2011 (in millions, except per share data):
		One Month Ended
		December 31,
		2012			2011
					(unaudited)
	Statement of Income Data:
	Net interest income	$	492		$	442
	Provision for loan losses	178			173
	Other income	200			211
	Other expense	240			217
	Income before income tax expense	274			263
	Income tax expense	104			99
	Net income	$	170		$	164
	Net income allocated to common stockholders	$	168		$	162
	Per Share of Common Stock:
	Basic earnings per common share	$	0.34		$	0.31
	Diluted earnings per common share	$	0.34		$	0.3
	Weighted average shares outstanding	498			529
	Weighted average shares outstanding (fully diluted)	499			530
	Statement of Financial Condition Data (as of):
	Total loan receivables	$	62,598		$	59,372
	Allowance for loan losses	$	(1,788	)	$	(2,245	)
	Total assets	$	73,491		$	69,473
	Long-term borrowings	$	17,666		$	18,265
	Total liabilities	$	63,618		$	61,115
	Total stockholders' equity	$	9,873		$	8,358

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2013
Subsequent Events [Abstract]	'
Subsequent Events	'
	Subsequent Events
	The Company has evaluated events and transactions that have occurred subsequent to December 31, 2013 and determined there were no subsequent events that would require recognition or disclosure in the consolidated financial statements.

Quarterly_Results

Quarterly Results	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Data [Abstract]	'
Quarterly Results	'
	Quarterly Results
	The following table provides unaudited quarterly results. As discussed previously, the Company changed its fiscal year end from November 30 to December 31 of each year. This fiscal year change was effective January 1, 2013. As a result of the change, the Company had a one month transition period in December 2012 that is not represented in this table of quarterly results. For information on the one month transition period, see Note 26: Transition Period Financial Information (dollars in millions, except per share data):
		31-Dec-13		30-Sep-13		30-Jun-13		31-Mar-13		30-Nov-12		August 31,		May 31,		February
												2012		2012		29, 2012
	Interest income	$	1,842	$	1,787	$	1,727	$	1,708	$	1,706	$	1,695	$	1,656	$	1,646
	Interest expense	273		278		297		298		312		325		341		353
	Net interest income	1,569		1,509		1,430		1,410		1,394		1,370		1,315		1,293
	Provision for loan losses	354		333		240		159		338		126		232		152
	Gain (loss) on investments	2		—		—		3		26		—		—		—
	Other income	558		553		611		579		578		594		533		550
	Other expense	838		783		820		753		800		826		749		677
	Income before income tax expense	937		946		981		1,080		860		1,012		867		1,014
	Income tax expense	335		353		379		407		309		385		330		384
	Net income	$	602	$	593	$	602	$	673	$	551	$	627	$	537	$	630
	Net income allocated to common stockholders(1)	$	588	$	579	$	588	$	659	$	541	$	621	$	532	$	624
	Basic earnings per common share(1)	$	1.24	$	1.2	$	1.2	$	1.33	$	1.08	$	1.21	$	1.01	$	1.18
	Diluted earnings per common share(1)	$	1.23	$	1.2	$	1.2	$	1.33	$	1.07	$	1.21	$	1	$	1.18
	-1	Because the inputs to net income allocated to common stockholders and earnings per share are calculated using weighted averages for the quarter, the sum of all four quarters may differ from the year to date amounts in the consolidated statements of income.

Background_and_Basis_of_Presen1

Background and Basis of Presentation (Policies)	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation and Significant Accounting Policies	'
	Basis of Presentation
	The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”).
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 consolidated financial statements and related disclosures. These estimates are based on information available as of the date of the consolidated financial statements. The Company believes that the estimates used in the preparation of the consolidated financial statements are reasonable. Actual results could differ from these estimates.
Consolidation	'
	Principles of Consolidation
	The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. The Company's policy is to consolidate all entities in which it owns more than 50% of the outstanding voting stock unless it does not control the entity. However, the Company did not have a controlling voting interest in any entity other than its wholly-owned subsidiaries in the periods presented in the accompanying consolidated financial statements.
	It is also the Company's policy to consolidate any variable interest entity for which the Company is the primary beneficiary, as defined by GAAP. On this basis, the Company consolidates the Discover Card Master Trust I and the Discover Card Execution Note Trust as well as three student loan securitization trusts acquired in 2010. The Company is deemed to be the primary beneficiary of each of these trusts since it is, for each, the trust servicer and the holder of both the residual interest and the majority of the most subordinated interests. Because of those involvements, the Company has, for each trust, i) the power to direct the activities that most significantly impact the economic performance of the trust, and ii) the obligation (or right) to absorb losses (or receive benefits) of the trust that could potentially be significant. The Company has determined that it was not the primary beneficiary of any other variable interest entity during the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 or one month ended December 31, 2012.
	For investments in any entities in which the Company owns 50% or less of the outstanding voting stock but in which the Company has significant influence over operating and financial decisions, the Company applies the equity method of accounting. In cases where the Company's equity investment is less than 20% and significant influence does not exist, such investments are carried at cost.
Fair Value of Financial Instruments	'
	The fair values of these financial assets and liabilities, which are not carried at fair value on the 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 statements 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 10: 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 statements of financial condition, approximates fair value as it is short term in nature and is payable in less than one year.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	Cash and cash equivalents is defined by the Company as cash on deposit with banks, including time deposits and other highly liquid investments, with maturities of 90 days or less when purchased. Cash and cash equivalents included $719 million and $797 million of cash and due from banks and $5.8 billion and $1.8 billion of interest-earning deposits in other banks at December 31, 2013 and 2012, respectively.
Restricted Cash	'
	Restricted Cash
	Restricted cash includes cash for which the Company's ability to withdraw funds at any time is contractually limited. Restricted cash is generally designated for specific purposes arising out of certain contractual or other obligations.
Investment Securities	'
	Investment Securities
	At December 31, 2013, investment securities consisted of U.S. Treasury and U.S. government agency obligations, mortgage-backed securities issued by government agencies, debt instruments issued by states and political subdivisions of states and credit card asset-backed securities issued by other institutions. Investment securities that the Company has the positive intent and ability to hold to maturity are classified as held-to-maturity and are reported at amortized cost. All other investment securities are classified as available-for-sale, as the Company does not hold investment securities for trading purposes. Available-for-sale investment securities are reported at fair value with unrealized gains and losses, net of tax, reported as a component of accumulated other comprehensive income included in stockholders' equity. The Company estimates the fair value of available-for-sale investment securities pursuant to the guidance in ASC Topic 820, Fair Value Measurements and Disclosures (“ASC 820”) as more fully discussed in Note 21: Fair Value Measurements and Disclosures. The amortized cost for each held-to-maturity and available-for-sale investment security is adjusted for amortization of premiums or accretion of discounts, as appropriate. Such amortization or accretion is included in interest income. The Company evaluates its unrealized loss positions for other-than-temporary impairment in accordance with GAAP applicable for investments in debt and equity securities. Realized gains and losses and other-than-temporary impairments related to investment securities are determined at the individual security level and are reported in other income.
Mortgage Loans Held for Sale	'
	Mortgage Loans Held for Sale
	Mortgage loans held for sale consist of residential first mortgage loans that are secured by residential real estate throughout the United States. The Company originates all of its residential real estate loans with the intent to sell them in the secondary market on a servicing-released basis and classifies them as held for sale at the time of origination. The Company includes mortgage loans held for sale in total loan receivables and carries these assets at fair value pursuant to an optional fair value measurement election. Changes in fair value are recorded through revenue 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 "— Financial Instruments Used for Asset and Liability Management" and Note 22: Derivatives and Hedging Activities for further discussion of mortgage-related hedging activities and see Note 21: Fair Value Measurements and Disclosures for further discussion on estimating fair value for mortgage loans held for sale). The Company recognizes interest income on these loans separately from changes in their fair value.
Loan Receivables	'
	Loan Receivables
	Loan receivables consist of credit card receivables and other loans and include purchased credit-impaired ("PCI") loans as well as loans held for sale. Loan receivables also include unamortized net deferred loan origination fees and costs (also see “— Loan Interest and Fee Income”). Credit card loan receivables include consumer credit card loan receivables and business credit card loan receivables. Credit card loan receivables are reported at their principal amounts outstanding and include uncollected billed interest and fees and are reduced for unearned revenue related to balance transfer fees (also see “— Loan Interest and Fee Income”). Other loans consist of student loans, personal loans and other loans and are reported at their principal amounts outstanding. With the exception of mortgages, the Company's loan receivables are deemed to be held for investment at origination or acquisition because management has the intent and ability to hold them for the foreseeable future.
	PCI loans are loans acquired at prices which reflected a discount related to deterioration in individual loan credit quality since origination. The Company's PCI loans are comprised entirely of private student loans acquired during the 2011 fiscal year. These loans are accounted for pursuant to ASC Subtopic 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality.
	The PCI student loans were aggregated into pools based on common risk characteristics at the time of their acquisition. Loans were grouped primarily on the basis of origination date as loans originated in a particular year generally reflect the application of common origination strategies and/or underwriting criteria. Each pool is accounted for as a single asset and each has a single composite interest rate, total contractual cash flows and total expected cash flows.
	Interest income on PCI loans is recognized on the basis of expected cash flows rather than contractual cash flows. The total amount of interest income recognizable on a pool of PCI loans (i.e., its accretable yield) is the difference between the carrying amount of the loan pool and the future cash flows expected to be collected without regard to whether the expected cash flows represent principal or interest collections. Interest is recognized on an effective yield basis over the life of the loan pool.
	The initial estimates of the fair value of the PCI student loans included the impact of expected credit losses, and therefore, no allowance for loan loss was recorded as of the purchase dates. The difference between contractually required cash flows and cash flows expected to be collected, as measured at the acquisition dates, is not permitted to be accreted. Charge-offs are absorbed by this non-accretable difference and do not result in a charge to earnings.
	The estimate of cash flows expected to be collected is evaluated each reporting period to ensure it reflects management's latest expectations of future credit losses and borrower prepayments, and interest rates in effect in the current period. To the extent expected credit losses increase after the acquisition dates, the Company will record an allowance for loan losses through the provision for loan losses, which will reduce net income. Changes in expected cash flows related to changes in prepayments or interest rate indices for variable rate loans generally are recorded prospectively as adjustments to interest income.
	To the extent that a significant increase in cash flows due to lower expected losses is deemed probable, the Company will first reverse any previously established allowance for loan losses and then increase the amount of remaining accretable yield. The increase to yield would be recognized prospectively over the remaining life of the loan pool. An increase in the accretable yield would reduce the remaining non-accretable difference available to absorb subsequent charge-offs. Disposals of loans, which may include sales of loans or receipt of payments in full from the borrower or charge-offs, result in removal of the loans from their respective pools.
	Cash flows associated with loans that are originated or acquired with the intent to sell are included in cash flows from operating activities. Cash flows associated with loans originated or acquired for investment are classified as cash flows from investing activities, regardless of a subsequent change in intent.
Delinquent Loans	'
	Delinquent Loans
	The entire balance of an account is contractually past due if the minimum payment is not received by the specified date on the customer's billing statement. Delinquency is reported on loans that are 30 days or more past due.
	Credit card loans are charged off at the end of the month during which an account becomes 180 days past due. Closed-end consumer loan receivables are charged off at the end of the month during which an account becomes 120 days contractually past due. 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 time frame described above. Receivables associated with alleged or potential fraudulent transactions are adjusted to their net realizable value upon receipt of notification of such fraud through a charge to other expense and are subsequently written off at the end of the month 90 days following notification, but not later than the contractual 180-day or 120-day time frame described above. The Company's charge-off policies are designed to comply with guidelines established by the Federal Financial Institutions Examination Council (“FFIEC”).
	The practice of re-aging an account also may affect loan delinquencies and charge-offs. A re-age is intended to assist delinquent customers who have experienced financial difficulties but who demonstrate both an ability and willingness to repay. Accounts meeting specific criteria are re-aged when the Company and the customer agree on a temporary repayment schedule that may include concessionary terms. With re-aging, the outstanding balance of a delinquent account is returned to a current status. Customers may also qualify for a workout re-age when either a longer term or permanent hardship exists. The Company's re-age practices are designed to comply with FFIEC guidelines.
Allowance for Loan Losses	'
	Allowance for Loan Losses
	The Company maintains an allowance for loan losses at a level that is appropriate to absorb probable losses inherent in the loan portfolio. The estimate of probable incurred losses considers uncollectible principal, interest and fees reflected in the loan receivables. The allowance is evaluated monthly for appropriateness 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.
	The Company calculates its allowance for loan losses by estimating probable losses separately for classes of the loan portfolio with similar loan characteristics, which generally results in segmenting the portfolio by loan product type.
	For its credit card loan receivables, the Company bases its allowance for loan loss 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 does not evaluate credit card loans for impairment on an individual basis, but instead estimates its allowance for credit card loan losses on a pooled basis, which includes loans that are delinquent and/or no longer accruing interest.
	For its other loans, the Company considers historical and forecasted estimates of incurred losses in estimating the related allowance for loan losses. The Company also considers other factors, such as current economic conditions, recent trends in delinquencies and bankruptcy filings, account collection management, policy changes, account seasoning, loan volume and amounts, payment rates and forecasting uncertainties. Similar to credit card loans, the Company estimates its allowance for personal and student loan losses on a pooled basis, which includes loans that are delinquent and/or no longer accruing interest.
	As part of certain collection strategies, the Company may modify the terms of loans to customers experiencing financial hardship. Temporary and permanent modifications on credit card loans, certain grants of student loan forbearance and certain short and long-term modifications to personal loans are considered troubled debt restructurings and are accounted for in accordance with ASC Subtopic 310-40, Troubled Debt Restructuring by Creditors. With respect to student loans, the Company does not anticipate significant shortfalls in collections on the contractual amounts due from 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.
	Loan receivables, other than PCI loans, that have been modified under a troubled debt restructuring are evaluated separately from the pools of receivables that are subject to the collective analyses described above. Loan receivables modified in a troubled debt restructuring are recorded at their present values with impairment measured as the difference between the loan balance and the discounted present value of cash flows expected to be collected. Changes in the present value are recorded in the provision for loan losses. All of the Company's troubled debt restructurings, which are evaluated collectively on an aggregated (by loan type) basis, have a related allowance for loan losses.
Premises and Equipment, net	'
	Premises and Equipment, net
	Premises and equipment, net, are stated at cost less accumulated depreciation and amortization, which is computed using the straight-line method over the estimated useful lives of the assets. Buildings are depreciated over a period of 39 years. The costs of leasehold improvements are capitalized and depreciated over the lesser of the remaining term of the lease or the asset's estimated useful life, typically ten years. Furniture and fixtures are depreciated over a period of five to ten years. Equipment is depreciated over three to ten years. Capitalized leases, consisting of computers and processing equipment, are depreciated over three and six years, respectively. Maintenance and repairs are immediately expensed, while the costs of improvements are capitalized.
	Purchased software and capitalized costs related to internally developed software are amortized over their useful lives of three to ten years. Costs incurred during the application development stage related to internally developed software are capitalized in accordance with ASC Subtopic 350-40, Intangibles - Goodwill and Other: Internal Use Software. Pursuant to that guidance, costs are expensed as incurred during the preliminary project stage and post implementation stage. Once the capitalization criteria as defined in GAAP have been met, external direct costs incurred for materials and services used in developing or obtaining internal-use computer software and payroll and payroll-related costs for employees who are directly associated with the internal-use computer software project (to the extent those employees devoted time directly to the project) are capitalized. Amortization of capitalized costs begins when the software is ready for its intended use. Capitalized software is included in premises and equipment, net in the Company's consolidated statements of financial condition. See Note 7: Premises and Equipment for further information about the Company's premises and equipment.
Goodwill	'
	Goodwill
	Goodwill is recorded as part of the Company's acquisitions of businesses when the purchase price exceeds the fair value of the net tangible and separately identifiable intangible assets acquired. The Company's goodwill is not amortized, but rather is subject to an impairment test at the reporting unit level annually, or between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount, pursuant to ASC Topic 350, Intangibles - Goodwill and Other. The Company's reported goodwill relates to PULSE, acquired in 2005, and to the Home Loan Center mortgage origination business acquired in 2012. The Company's goodwill impairment analysis is a two-step test. In the first step, the fair value of the reporting unit is compared to its carrying value. If the fair value of the reporting unit exceeds its carrying value including goodwill, goodwill is not impaired. If the carrying value including goodwill exceeds its fair value, goodwill is potentially impaired and the second step of the test becomes necessary. In the second step, the implied fair value of goodwill is derived and compared to the carrying amount of goodwill. The implied fair value of goodwill is the excess of the fair value of the reporting unit over the sum of the fair values of all identifiable assets less the liabilities associated with the reporting unit. If the carrying value of goodwill allocated to the reporting unit exceeds its implied fair value, an impairment charge is recorded for the excess.
	Historically, the Company’s policy was to perform the annual impairment test of goodwill as of June 1 of each year. The 2013 annual impairment test was conducted in accordance with this policy and identified no impairment. During the fourth quarter of 2013, the Company changed the date of its annual goodwill impairment test to October 1. The change in goodwill impairment testing date is deemed a change in accounting principle which management determined to be preferable under the circumstances. The change was made to better align with the timing of its annual and long-term planning process, which is a significant element in the testing process. Due to the change in the Company’s fiscal year end from November 30 to December 31, the change from June 1 to October 1 also enhances the ability of the Company to obtain carrying values for use in the testing process by using the beginning of a fiscal quarter.
	In connection with the change in date of the annual goodwill impairment test, the Company performed a goodwill impairment test on October 1, 2013, and no impairment charge was identified. This change did not delay, accelerate, or avoid a goodwill impairment charge. The goodwill impairment tests on June 1, 2013 and October 1, 2013 were performed such that a period greater than 12 months did not elapse between test dates. The change in the annual goodwill impairment testing date was applied prospectively beginning on October 1, 2013 and had no effect on the consolidated financial statements. This change was not applied retrospectively as it is impracticable to do so because retrospective application would have required the application of significant estimates and assumptions without the use of hindsight.
Intangible Assets	'
	Intangible Assets
	The Company's identifiable intangible assets consist of both amortizable and nonamortizable intangible assets. The Company's amortizable intangible assets consist primarily of acquired customer relationships and certain trade name intangibles. All of the Company's amortizable intangible assets are carried at net book value and are amortized over their estimated useful lives. The amortization periods approximate the periods over which the Company expects to generate future net cash inflows from the use of these assets. The Company's policy is to amortize intangibles in a manner that reflects the pattern in which the projected net cash inflows to the Company are expected to occur, where such pattern can be reasonably determined, as opposed to the straight-line basis. This method of amortization typically results in a greater portion of the intangible asset being amortized in the earlier years of its useful life.
	All of the Company's amortizable intangible assets, as well as other amortizable or depreciable long-lived assets such as premises and equipment, are subject to impairment testing when events or conditions indicate that the carrying value of an asset may not be fully recoverable from future cash flows. A test for recoverability is done by comparing the asset's carrying value to the sum of the undiscounted future net cash inflows expected to be generated from the use of the asset over its remaining useful life. Impairment exists if the sum of the undiscounted expected future net cash inflows is less than the carrying amount of the asset. Impairment would result in a write-down of the asset to its estimated fair value. The estimated fair values of these assets are based on the discounted present value of the stream of future net cash inflows expected to be derived over the remaining useful lives of the assets. If an impairment write-down is recorded, the remaining useful life of the asset will be evaluated to determine whether revision of the remaining amortization or depreciation period is appropriate.
	The Company's nonamortizable intangible assets consist of the international transaction processing rights and brand-related intangibles included in the acquisition of Diners Club as well as the trade names acquired in The Student Loan Corporation acquisition. These assets are deemed to have indefinite useful lives and are therefore not subject to amortization. All of the Company's nonamortizable intangible assets are subject to a test for impairment annually, or more frequently if events or changes in circumstances indicate that the asset might be impaired. As required by GAAP, if the carrying value of a nonamortizable intangible asset is in excess of its fair value, the asset must be written down to its fair value through the recognition of an impairment charge to earnings. In contrast to amortizable intangibles, there is no test for recoverability associated with the impairment test for nonamortizable intangible assets.
	During the fourth quarter of 2013, the Company changed the date of its annual impairment test for nonamortizable intangible assets from June 1 to October 1 to coincide with the change in the Company's goodwill impairment test date. The Company performed impairment tests at June 1, 2013 and October 1, 2013, and as such a period greater than 12 months did not elapse between test dates. No impairment charges were identified during the impairment tests conducted at June 1, 2013 and October 1, 2013.
Stock-based Compensation	'
	Stock-based Compensation
	The Company measures the cost of employee services received in exchange for an award of stock-based compensation based on the grant-date fair value of the award. The cost is recognized over the requisite service period, except for awards granted to retirement-eligible employees, which are fully expensed by the grant date. No compensation cost is recognized for awards that are subsequently forfeited.
Advertising Costs	'
	Advertising Costs
	The Company expenses advertising costs as incurred. Television advertising costs are expensed in the period in which the advertising is first aired. Advertising costs are recorded in marketing and business development and were $208 million, $172 million, $150 million and $17 million for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, respectively.
Income Taxes	'
	Income Taxes
	Income tax expense is provided for using the asset and liability method, under which deferred tax assets and liabilities are determined based on the temporary differences between the financial statement and income tax bases of assets and liabilities using currently enacted tax rates. Deferred tax assets are recognized when their realization is determined to be more likely than not, in accordance with the accounting guidance. Uncertain tax positions are measured at the highest amount of tax benefit for which realization is judged to be more likely than not. Tax benefits that do not meet these criteria are unrecognized tax benefits. See Note 16: Income Taxes for more information about the Company's income taxes.
Financial Instruments Used for Asset and Liability Management	'
	Financial Instruments Used for Asset and Liability Management
	The Company utilizes derivative financial instruments to manage its various exposures to changes in fair value of certain assets and liabilities, variability in future cash flows arising from changes in interest rates, or other types of forecasted transactions, and changes in foreign exchange rates. All derivatives are carried at their estimated fair values on the Company’s consolidated statements of financial condition. Derivatives having positive net fair values, inclusive of net accrued interest receipts or payments, are recorded in other assets. Derivatives with negative net fair values, inclusive of net accrued interest payments or receipts, are recorded in accrued expenses and other liabilities. The methodologies used to estimate the fair values of these derivative financial instruments are described in Note 21: Fair Value Measurements and Disclosures. Collateral receivable or payable amounts associated with derivatives are not offset against the fair value of these derivatives, but are recorded separately in other assets or deposits, respectively.
	Certain of these instruments are designated and qualify for hedge accounting in accordance ASC Topic 815, Derivatives and Hedging. Under cash flow hedge accounting, the effective portion of the change in the fair value of these derivative instruments is recognized in other comprehensive income. The change in fair value of these derivative instruments relating to the ineffective portion is recognized immediately in other income. Amounts accumulated in other comprehensive income are reclassified to earnings in the period during which the hedged items affect income. For a net investment hedge, the effective portion of changes in the fair value of the derivatives is 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. Under fair value hedge accounting, changes in both (i) the fair values of the derivative instruments and (ii) the fair values of the hedged items relating to the risks being hedged, including net differences, if any (i.e., ineffectiveness), are recorded in interest expense. Certain other derivatives are not designated as hedges and do not qualify for hedge accounting; changes in the fair value of these derivatives are recorded in other income. These transactions are discussed in more detail in Note 22: Derivatives and Hedging Activities.
Accumulated Other Comprehensive Income	'
	Accumulated Other Comprehensive Income
	The Company records unrealized gains and losses on available-for-sale securities, changes in the fair value of cash flow hedges, and certain pension and foreign currency translation adjustments in other comprehensive income ("OCI") on an after-tax basis where applicable. Details of other comprehensive income, net of tax, are presented in the statement of comprehensive income, and a rollforward of accumulated other comprehensive income ("AOCI") is presented in the statement of changes in stockholders' equity and Note 14: Accumulated Other Comprehensive Income.
Significant Revenue Recognition Accounting Policies	'
	Significant Revenue Recognition Accounting Policies
	Loan Interest and Fee Income
	Interest on loans is comprised largely of interest on credit card loans and is recognized based upon the amount of loans outstanding and their contractual interest rate. Interest on credit card loans is included in loan receivables when billed to the customer. The Company accrues unbilled interest revenue each month from a customer's billing cycle date to the end of the month. The Company applies an estimate of the percentage of loans that will revolve in the next cycle in the estimation of the accrued unbilled portion of interest revenue that is included in accrued interest receivable on the consolidated statements of financial condition. Interest on other loan receivables is accrued monthly in accordance with their contractual terms and recorded in accrued interest receivable, which is included in other assets, in the consolidated statements of financial condition. Interest related to purchased credit-impaired loans is discussed in Note 5: Loan Receivables.
	The Company recognizes fees (except annual fees, balance transfer fees and certain product fees) on loan receivables in interest income or loan fee income as the fees are assessed. Annual fees, balance transfer fees and certain product fees are recognized in interest income or loan fee income ratably over the periods to which they relate. Balance transfer fees are accreted to interest income over the life of the related balance. As of December 31, 2013 and 2012, deferred revenues related to balance transfer fees, recorded as a reduction of loan receivables, were $37 million and $34 million, respectively. Loan fee income consists of fees on credit card loans and includes annual, late, returned check, cash advance and other miscellaneous fees and is reflected net of waivers and charge-offs.
	Pursuant to ASC Subtopic 310-20, Receivables - Nonrefundable Fees and Other Costs, direct loan origination costs on credit card loans are deferred and amortized on a straight-line basis over a one-year period and recorded in interest income from credit card loans. Direct loan origination costs on other loan receivables are deferred and amortized over the life of the loan using the interest method and is recorded in interest income from other loans. As of December 31, 2013 and 2012, the remaining unamortized deferred costs related to loan origination were $43 million and $29 million, respectively, and were recorded in loan receivables.
	The Company accrues interest and fees on loan receivables until the loans are paid or charged off, except in instances of customer bankruptcy, death or fraud, where no further interest and fee accruals occur following notification. Payments received on nonaccrual loans are allocated according to the same payment hierarchy methodology applied to loans that are accruing interest. When loan receivables are charged off, unpaid accrued interest and fees are reversed against the income line items in which they were originally recorded in the consolidated statements of income. Charge-offs and recoveries of amounts which relate to capitalized interest on student loans are treated as principal charge-offs and recoveries, affecting the provision for loan losses rather than interest income. The Company considers uncollectible interest and fee revenues in assessing the adequacy of the allowance for loan losses.
	Discount and Interchange Revenue
	The Company earns discount revenue from fees charged to merchants with whom the Company has entered into card acceptance agreements for processing credit card purchase transactions. We earn acquirer interchange revenue from merchant acquirers on all Discover Network, Diners Club and PULSE transactions made by credit and debit cardholders at merchants with whom merchant acquirers have entered into card acceptance agreements for processing payment card transactions. The Company pays issuer interchange to network partners who have entered into contractual arrangements to issue cards on the Company's networks as compensation for risk and other operating costs. The discount revenue or acquirer interchange is recognized as revenue, net of any associated issuer interchange cost, at the time the transaction is captured.
	Customer Rewards
	The Company offers its customers various reward programs, including the Cashback Bonus reward program, pursuant to which the Company pays certain customers a reward equal to a percentage of their credit card purchase amounts based on the type and volume of the customer's purchases. The liability for customer rewards, which is included in accrued expenses and other liabilities on the consolidated statements of financial condition, is estimated on an individual customer basis and is accumulated as qualified customers make progress toward earning the reward through their ongoing credit card purchase activity or other defined actions. In determining the appropriate liability for customer rewards, the Company estimates forfeitures of rewards accumulated but not redeemed based on historical account closure and charge-off experience, actual customer credit card purchase activity and the terms of the rewards program. In accordance with ASC Subtopic 605-50, Revenue Recognition: Customer Payments and Incentives (“ASC 605-50”), the Company recognizes customer rewards costs as a reduction of the related revenue, if any. In instances where a reward is not associated with a revenue-generating transaction, such as when a reward is given for opening an account, the reward cost is recorded as an operating expense. For the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, rewards costs, adjusted for estimated forfeitures, amounted to $1.0 billion, $1.0 billion, $879 million and $123 million, respectively. At both December 31, 2013 and 2012, the liability for customer rewards, adjusted for estimated forfeitures, was $1.1 billion, which is included in accrued expenses and other liabilities on the consolidated statements of financial condition.
	Protection Products
	The Company earns revenue related to fees received for marketing products or services that are ancillary to the Company's credit card and personal loans, including payment protection products and identity theft protection services, to the Company's customers. The amount of revenue recorded is based on the terms of the agreements and contracts with the third parties that provide these services. The Company recognizes this income over the customer agreement or contract period as earned.
	Transaction Processing Revenue
	Transaction processing revenue represents fees charged to financial institutions and merchant acquirers/processors for processing ATM and debit point-of-sale transactions over the PULSE network and is recognized at the time the transactions are processed. Transaction processing revenue also includes network participant revenue earned by PULSE related to fees charged for maintenance, support, information processing and other services provided to financial institutions, processors and other participants in the PULSE network. These revenues are recognized in the period that the related transactions occur or services are rendered.
	Royalty and Licensee Revenue
	The Company earns revenue from licensing fees for granting the right to use the Diners Club brand and processing fees for providing various services to Diners Club licensees, which are referred to together as royalty and licensee revenue. Royalty revenue is recognized in the period that the cardholder volume used to calculate the royalty fee is generated. Processing fees are recognized in the month that the services are provided. Royalty and licensee revenue is included in other income on the consolidated statements of income.
	Incentive Payments
	The Company makes certain incentive payments under contractual arrangements with financial institutions, Diners Club licensees, merchants, acquirers and certain other customers. In accordance with ASC 605-50, these payments are generally classified as contra-revenue unless a specifically identifiable benefit is received by the Company in consideration for the payment and the fair value of such benefit is reasonably estimable and measurable. If no such benefit is identified, then the entire payment is classified as contra-revenue, and included in other income in the consolidated statements of income in the line item where the related revenues are recorded. If the payment gives rise to an asset because it is expected to directly or indirectly contribute to future net cash inflows, it is deferred and recognized over the expected benefit period. The unamortized portion of the deferred incentive payments included in other assets on the consolidated statements of financial condition was $23 million and $41 million at December 31, 2013 and 2012, respectively.

Investments_Tables

Investments (Tables)	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
Schedule of Investment Securities	'
	The Company’s investment securities consist of the following (dollars in millions):
		December 31,							November 30,
		2013			2012				2012				2011
	U.S. Treasury securities(1)	$	2,058		$	2,460			$	2,463			$	2,564
	U.S. government agency securities	1,561			2,233				2,237				2,795
	States and political subdivisions of states	15			34				34				41
	Other securities:
	Credit card asset-backed securities of other issuers	6			151				159				300
	Corporate debt securities(2)	—			—				75				450
	To-be-announced investment securities(3)	—			—				—				50
	Residential mortgage-backed securities - Agency(4)	1,351			1,354				1,253				6
	Total other securities	1,357			1,505				1,487				806
	Total investment securities	$	4,991		$	6,232			$	6,221			$	6,206
	-1	Includes $9 million of U.S. Treasury securities that have been pledged as swap collateral in lieu of cash as of December 31, 2013.
	-2	Amount represents corporate debt obligations issued under the Temporary Liquidity Guarantee Program (TLGP) that are guaranteed by the Federal Deposit Insurance Corporation (FDIC).
	-3	The Company’s to-be-announced investment securities are forward contracts for regular-way purchases of government agency mortgage-backed securities. They are accounted for as investment securities rather than as derivative instruments. These contracts are for the purchase of mortgage-backed securities with a stated coupon and original term to maturity but for which the specific underlying mortgage loans are not known at the inception of the contract or at the end of the reporting period.
	-4	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
	At December 31, 2013
	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
	At December 31, 2012
	Available-for-Sale Investment Securities(1)
	U.S. Treasury securities	$	2,413		$	46			$	—			$	2,459
	U.S. government agency securities	2,187			46				—				2,233
	Credit card asset-backed securities of other issuers	149			2				—				151
	Residential mortgage-backed securities - Agency	1,282			20				—				1,302
	Total available-for-sale investment securities	$	6,031		$	114			$	—			$	6,145
	Held-to-Maturity Investment Securities(2)
	U.S. Treasury securities(3)	$	1		$	—			$	—			$	1
	States and political subdivisions of states	34			—				—				34
	Residential mortgage-backed securities - Agency(4)	52			2				—				54
	Total held-to-maturity investment securities	$	87		$	2			$	—			$	89
	-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 Twelve Months and More Than Twelve 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 as of December 31, 2013. Aggregate gross unrealized losses on investment securities were not material as of December 31, 2012 (dollars in millions):
		Number of Securities in a Loss Position		Less than 12 months								More than 12 months
				Fair				Unrealized				Fair			Unrealized
				Value				Losses				Value			Losses
	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 and weighted average yields of available-for-sale debt securities and held-to-maturity debt securities at December 31, 2013 are provided in the tables below (dollars in millions):
		One Year			After One				After Five				After Ten			Total
		or			Year				Years				Years
		Less			Through				Through
					Five Years				Ten Years
	Available-for-Sale—Amortized Cost(1)
	U.S. Treasury securities	$	709		$	1,321			$	—			$	—		$	2,030
	U.S. government agency securities	508			1,027				—				—			1,535
	Credit card asset-backed securities of other issuers	6			—				—				—			6
	Residential mortgage-backed securities - Agency	—			—				401				928			1,329
	Total available-for-sale investment securities	$	1,223		$	2,348			$	401			$	928		$	4,900
	Held-to-Maturity—Amortized Cost(2)
	U.S. Treasury securities	$	1		$	—			$	—			$	—		$	1
	State and political subdivisions of states	—			—				—				15			15
	Residential mortgage-backed securities - Agency	—			—				—				44			44
	Total held-to-maturity investment securities	$	1		$	—			$	—			$	59		$	60
	Available-for-Sale—Fair Values(1)
	U.S. Treasury securities	$	711		$	1,346			$	—			$	—		$	2,057
	U.S. government agency securities	511			1,050				—				—			1,561
	Credit card asset-backed securities of other issuers	6			—				—				—			6
	Residential mortgage-backed securities - Agency	—			—				398				909			1,307
	Total available-for-sale investment securities	$	1,228		$	2,396			$	398			$	909		$	4,931
	Held-to-Maturity—Fair Values(2)
	U.S. Treasury securities	$	1		$	—			$	—			$	—		$	1
	State and political subdivisions of states	—			—				—				14			14
	Residential mortgage-backed securities - Agency	—			—				—				43			43
	Total held-to-maturity investment securities	$	1		$	—			$	—			$	57		$	58
	-1	Available-for-sale investment securities are reported at fair value.
	-2	Held-to-maturity investment securities are reported at amortized cost.
		One Year		After One			After Five			After Ten			Total
		or		Year			Years			Years
		Less		Through			Through
				Five Years			Ten Years
	Available-for-Sale—Weighted Average Yields(1)
	U.S Treasury securities	0.65	%	1.45	%		—	%		—	%		1.17	%
	U.S government agency securities	0.92	%	1.72	%		—	%		—	%		1.46	%
	Credit card asset-backed securities of other issuers	12.83	%	—	%		—	%		—	%		12.83	%
	Residential mortgage-backed securities - Agency	—	%	—	%		1.44	%		1.96	%		1.8	%
	Total available-for-sale investment securities	0.82	%	1.57	%		1.44	%		1.96	%		1.45	%
	Held-to-Maturity—Weighted Average Yields
	U.S. Treasury securities	0.08	%	—	%		—	%		—	%		0.08	%
	State and political subdivisions of states	—	%	4.27	%		—	%		4.68	%		4.67	%
	Residential mortgage-backed securities	—	%	—	%		—	%		3.27	%		3.27	%
	Total held-to-maturity investment securities	0.08	%	4.27	%		—	%		3.63	%		3.6	%
	-1	The weighted average yield for available-for-sale investment securities is calculated based on the amortized cost.
Schedule of Interest on Investment Securities	'
	The following table presents interest on investment securities (dollars in millions):
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,								For the One Month Ended December 31, 2012
					2012				2011
	Taxable interest	$	73		$	78			$	57			$	7
	Tax exempt interest	1			2				2				—
	Total income from investment securities	$	74		$	80			$	59			$	7

Loan_Receivables_Tables

Loan Receivables (Tables)	12 Months Ended
	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]	'
Schedule of Loan Receivables	'
	The Company's classes of receivables within the three portfolio segments are depicted in the table below (dollars in millions):
		December 31,
		2013				2012
	Mortgage loans held for sale(1)	$	148			$	355
	Loan portfolio:
	Credit card loans:
	Discover card(2)	52,952				50,929
	Discover business card	198				206
	Total credit card loans	53,150				51,135
	Other loans:
	Personal loans	4,191				3,296
	Private student loans	3,969				3,072
	Other	135				38
	Total other loans	8,295				6,406
	Purchased credit-impaired loans(3)	4,178				4,702
	Total loan portfolio	65,623				62,243
	Total loan receivables	65,771				62,598
	Allowance for loan losses	(1,648		)		(1,788		)
	Net loan receivables	$	64,123			$	60,810
	-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 $20.2 billion and $18.8 billion underlying investors’ interest in trust debt at December 31, 2013 and 2012, respectively, and $10.9 billion and $16.0 billion in seller's interest at December 31, 2013 and 2012, respectively. The decrease in the seller's interest from December 31, 2012 to December 31, 2013 is due in part to the removal of randomly-selected accounts from the credit card loan receivables restricted for securitization investors in order to reduce excess seller's interest. See Note 6: Credit Card and Student Loan Securitization Activities for further information.
	-3	Amounts include $2.2 billion and $2.5 billion of loans pledged as collateral against the notes issued from the Student Loan Corporation ("SLC") securitization trusts at December 31, 2013 and 2012, respectively. See Note 6: Credit Card and Student Loan Securitization Activities. Of the remaining $2.0 billion and $2.2 billion at December 31, 2013 and 2012, respectively, that were not pledged as collateral, approximately $22 million and $17 million represent loans eligible for reimbursement through an indemnification claim, respectively. 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 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
	At December 31, 2012
	Credit card loans:
	Discover card(2)	$	455			$	458			$	913			$	407			$	183
	Discover business card	2				2				4				2				1
	Total credit card loans	457				460				917				409				184
	Other loans:
	Personal loans(3)	18				8				26				7				4
	Private student loans (excluding PCI)(4)	28				9				37				7				2
	Other	—				1				1				—				2
	Total other loans (excluding PCI)	46				18				64				14				8
	Total loan receivables (excluding PCI)	$	503			$	478			$	981			$	423			$	192
	-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 $29 million, $32 million, $45 million and $3 million for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, respectively. The Company does not separately track 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' current balances and most recent interest rates.
	-2	Consumer credit card loans that are 90 or more days delinquent and accruing interest include $41 million and $52 million of loans accounted for as troubled debt restructurings at December 31, 2013 and 2012, 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 both December 31, 2013 and 2012, respectively.
	-4	Private student loans that are 90 or more days delinquent and accruing interest include $3 million and $2 million of loans accounted for as troubled debt restructurings at December 31, 2013 and 2012.
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 Calendar Year Ended December 31, 2013							For the Fiscal Years Ended November 30,													For the One Month Ended December 31, 2012
									2012							2011
		Net				Net			Net				Net			Net				Net		Net			Net
		Charge-offs				Charge-off Rate			Charge-offs				Charge-off Rate			Charge-offs				Charge-off Rate		Charge-offs			Charge-off Rate
	Credit card loans:
	Discover card	$	1,096			2.21	%		$	1,233			2.62	%		$	2,018			4.46	%	$	106		2.48	%
	Discover business card	4				2.05	%		7				3.36	%		18				7.27	%	—			2.08	%
	Total credit card loans	1,100				2.21	%		1,240				2.62	%		2,036				4.47	%	106			2.47	%
	Other loans:
	Personal loans	79				2.13	%		69				2.33	%		67				3.02	%	7			2.52	%
	Private student loans (excluding PCI)	46				1.3	%		19				0.73	%		7				0.48	%	2			0.81	%
	Other	1				1.96	%		—				0.1	%		2				9.27	%	—			—	%
	Total other loans (excluding PCI)	126				1.67	%		88				1.52	%		76				1.65	%	9			1.61	%
	Net charge-offs as a percentage of total loans (excluding PCI)	$	1,226			2.14	%		$	1,328			2.5	%		$	2,112			4.21	%	$	115		2.37	%
	Net charge-offs as a percentage of total loans (including PCI)	$	1,226			1.98	%		$	1,328			2.29	%		$	2,112			3.97	%	$	115		2.19	%
Schedule of Credit Risk Profile by FICO Score	'
	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			Less than 660
		Above			or No Score
	At December 31, 2013
	Discover card	83	%		17	%
	Discover business card	92	%		8	%
	Personal loans	97	%		3	%
	Private student loans (excluding PCI)(1)	95	%		5	%
	At December 31, 2012
	Discover card	83	%		17	%
	Discover business card	91	%		9	%
	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 for the calendar year ended December 31, 2013, one month period ended December 30, 2012 and fiscal years ended November 30, 2012 and 2011 (dollars in millions):
		For the Calendar Year Ended December 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	893				92				84				17				1,086
	Deductions:
	Charge-offs	(1,604		)		(86		)		(48		)		(1		)		(1,739		)
	Recoveries	504				7				2				—				513
	Net charge-offs	(1,100		)		(79		)		(46		)		(1		)		(1,226		)
	Balance at end of period	$	1,406			$	112			$	113			$	17			$	1,648
		For the One Month Ended December 31, 2012
		Credit Card				Personal Loans				Student Loans				Other				Total
	Balance at beginning of period	$	1,554			$	97			$	73			$	1			$	1,725
	Additions:
	Provision for loan losses	165				9				4				—				178
	Deductions:
	Charge-offs	(146		)		(8		)		(2		)		—				(156		)
	Recoveries	40				1				—				—				41
	Net charge-offs	(106		)		(7		)		(2		)		—				(115		)
	Balance at end of period	$	1,613			$	99			$	75			$	1			$	1,788
		For the Fiscal Year Ended November 30, 2012
		Credit Card				Personal Loans				Student Loans				Other				Total
	Balance at beginning of period	$	2,070			$	82			$	53			$	—			$	2,205
	Additions:
	Provision for loan losses	724				84				39				1				848
	Deductions:
	Charge-offs	(1,817		)		(73		)		(19		)		—				(1,909		)
	Recoveries	577				4				—				—				581
	Net charge-offs	(1,240		)		(69		)		(19		)		—				(1,328		)
	Balance at end of period	$	1,554			$	97			$	73			$	1			$	1,725
	The following tables provide changes in the Company’s allowance for loan losses for the calendar year ended December 31, 2013, one month period ended December 30, 2012 and fiscal years ended November 30, 2012 and 2011 (dollars in millions):
		For the Fiscal Year Ended November 30, 2011
		Credit Card				Personal Loans				Student Loans				Other				Total
	Balance at beginning of period	$	3,209			$	76			$	18			$	1			$	3,304
	Additions:
	Provision for loan losses	897				73				42				1				1,013
	Deductions:
	Charge-offs	(2,615		)		(69		)		(7		)		(2		)		(2,693		)
	Recoveries	579				2				—				—				581
	Net charge-offs	(2,036		)		(67		)		(7		)		(2		)		(2,112		)
	Balance at end of period	$	2,070			$	82			$	53			$	—			$	2,205
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 Calendar Year Ended December 31, 2013				For the Fiscal Years Ended November 30,								For the One Month Ended December 31, 2012
						2012				2011
	Interest and fees accrued subsequently charged off, net of recoveries (recorded as a reduction of interest income)	$	280			$	345			$	589			$	26
	Fees accrued subsequently charged off, net of recoveries (recorded as a reduction to other income)	$	59			$	67			$	106			$	5
Schedule of Allowance for Loan Losses and Recorded Investment in 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 December 31, 2013
	Allowance for loan losses 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 ASC 310-10-35(1)(2)	188				3				9				16				216
	Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				28				—				28
	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 ASC 310-10-35(1)(2)	1,123				31				28				79				1,261
	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
	At December 31, 2012
	Allowance for loan losses evaluated for impairment as:
	Collectively evaluated for impairment in accordance with ASC 450-20	$	1,433			$	95			$	71			$	1			$	1,600
	Evaluated for impairment in accordance with ASC 310-10-35(1)(2)	180				4				4				—				188
	Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				—				—				—
	Allowance for loan losses	$	1,613			$	99			$	75			$	1			$	1,788
	Recorded investment in loans evaluated for impairment as:
	Collectively evaluated for impairment in accordance with ASC 450-20	$	49,826			$	3,275			$	3,056			$	38			$	56,195
	Evaluated for impairment in accordance with ASC 310-10-35(1)(2)	1,309				21				16				—				1,346
	Acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	—				—				4,702				—				4,702
	Total recorded investment	$	51,135			$	3,296			$	7,774			$	38			$	62,243
	-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 $0.9 billion and $1.1 billion at December 31, 2013 and 2012 respectively. The unpaid principal balance of personal loans was $31 million and $21 million at December 31, 2013 and 2012, respectively. The unpaid principal balance of student loans was $26 million and $15 million at December 31, 2013 and 2012, respectively. All loans accounted for as troubled debt restructurings have a related allowance for loan losses.
Schedule of Troubled Debt Restructurings	'
	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 Calendar Year Ended December 31, 2013
	Credit card loans
	Modified credit card loans(3)	$	269			$	49			$	3
	Internal programs	$	468			$	9			$	66
	External programs	$	463			$	36			$	11
	Personal loans	$	26			$	3			$	1
	Student loans(4)	$	22			$	2			N/A
	For the Fiscal Year Ended November 30, 2012
	Credit card loans
	Modified credit card loans(3)	$	255			$	48			N/A
	Internal programs	$	557			$	17			$	73
	External programs	$	603			$	51			$	9
	Personal loans	$	16			$	2			N/A
	Student loans(4)	$	10			$	1			N/A
	For the Fiscal Year Ended November 30, 2011
	Credit card loans
	Modified credit card loans(3)	$	276			$	48			N/A
	Internal programs	$	537			$	21			$	65
	External programs	$	715			$	62			$	10
	Personal loans	$	7			$	1			N/A
	Student loans(4)	$	5			$	—			N/A
	For the One Month Ended December 31, 2012
	Credit card loans
	Modified credit card loans(3)	$	281			$	4			$	—
	Internal programs	$	509			$	1			$	6
	External programs	$	530			$	4			$	1
	Personal loans	$	21			$	—			N/A
	Student loans(4)	$	16			$	—			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 that have subsequently reverted back to the loans' pre-modification payment terms either due to noncompliance with the terms of the modification or successful completion of a temporary modification 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 Calendar Year Ended December 31, 2013							For the Fiscal Years Ended November 30,													For the One Month Ended December 31, 2012
									2012							2011
		Number of Accounts			Balances				Number of Accounts			Balances				Number of Accounts			Balances			Number of Accounts		Balances
	Accounts that entered a loan modification program during the period:
	Credit card:
	Internal programs	40,653			$	256			50,946			$	345			68,738			$	480		3,078		$	19
	External programs	35,020			$	189			40,530			$	227			52,705			$	310		2,614		$	14
	Personal loans	2,178			$	27			1,555			$	20			410			$	5		120		$	2
	Student loans	877			$	17			470			$	11			262			$	5		60		$	2
Schedule of Troubled Debt Restructurings That Subsequently Defaulted	'
	The following table presents the carrying value of loans that experienced a payment default during the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012 that had been modified in a troubled debt restructuring during the 15 months preceding the end of each period (dollars in millions):
		For the Calendar Year Ended December 31, 2013							For the Fiscal Years Ended November 30,													For the One Month Ended December 31, 2012
									2012							2011
		Number of Accounts			Aggregated Outstanding Balances Upon Default				Number of Accounts			Aggregated Outstanding Balances Upon Default				Number of Accounts			Aggregated Outstanding Balances Upon Default			Number of Accounts		Aggregated Outstanding Balances Upon Default
	Troubled debt restructurings that subsequently defaulted:
	Credit card (1)(2):
	Internal programs	9,186			$	57			15,703			$	106			18,354			$	131		945		$	6
	External programs	8,481			$	36			8,543			$	40			11,974			$	62		722		$	3
	Personal loans(2)	284			$	3			343			$	4			17			$	—		22		$	—
	Student loans(3)	628			$	12			172			$	4			19			$	1		42		$	1
	-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 for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012 (dollars in millions):
		For the Calendar Year Ended December 31, 2013				For the Fiscal Years Ended November 30,								For the One Month Ended December 31, 2012
						2012				2011
	Balance at beginning of period	$	2,072			$	2,580			$	—			$	2,096
	Acquisition of the Student Loan Corporation	—				—				1,920				—
	Acquisition of the additional private student loan portfolio from Citibank	—				—				855				—
	Accretion into interest income	(272		)		(303		)		(225		)		(24		)
	Other changes in expected cash flows	(220		)		(181		)		30				—
	Balance at end of period	$	1,580			$	2,096			$	2,580			$	2,072
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 by type of loan for the calendar year ended December 31, 2013, fiscal year ended November 30, 2012 and one month ended December 31, 2012 (dollars in millions):
		For the Calendar Year Ended December 31, 2013							For the Fiscal Year Ended November 30, 2012							For the One Month Ended December 31, 2012
		Amount				%			Amount				%			Amount				%
	Conforming(1)	$	2,721			67.77	%		$	1,213			70.28	%		$	218			60.06	%
	FHA(2)	1,290				32.13			513				29.72			145				39.94
	Jumbo(3)	4				0.1			—				—			—				—
	Total	$	4,015			100	%		$	1,726			100	%		$	363			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 as of December 31, 2013 and 2012 (dollars in millions):
		December 31,
		2013							2012
		Amount				%			Amount				%
	Conforming(1)	$	136			91.89	%		$	177			49.86	%
	FHA(2)	11				7.43			178				50.14
	Jumbo(3)	1				0.68			—				—
	Total	$	148			100	%		$	355			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.
Credit Card Receivable [Member]	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'
Schedule of Geographic Distribution of Loan Receivables	'
	The Company originates credit card loans throughout the United States. The geographic distribution of the Company's credit card loan receivables was as follows (dollars in millions):
		December 31,
		2013							2012
		$				%			$				%
	California	$	4,548			8.5	%		$	4,442			8.7	%
	Texas	4,299				8.1			4,090				8
	New York	3,649				6.9			3,457				6.8
	Florida	3,064				5.8			2,949				5.8
	Illinois	2,998				5.6			2,903				5.7
	Pennsylvania	2,823				5.3			2,703				5.3
	Ohio	2,324				4.4			2,233				4.4
	New Jersey	2,002				3.8			1,940				3.8
	Michigan	1,575				3			1,537				3
	Georgia	1,546				2.9			1,499				2.9
	Other States	24,322				45.7			23,382				45.6
	Total credit card loans	$	53,150			100	%		$	51,135			100	%
Total Other Loans and PCI Loans [Member]	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'
Schedule of Geographic Distribution of Loan Receivables	'
	The Company originates personal loans, student loans, other loans and PCI loans throughout the United States. The table below does not include mortgage loans held for sale. The geographic distribution of personal, student, other and PCI loan receivables was as follows (dollars in millions):
		December 31,
		2013							2012
		$				%			$				%
	New York	$	1,679			13.4	%		$	1,614			14.5	%
	California	1,167				9.4			1,039				9.4
	Pennsylvania	939				7.5			877				7.9
	Illinois	696				5.6			612				5.5
	Texas	637				5.1			542				4.9
	New Jersey	630				5.1			570				5.1
	Massachusetts	508				4.1			463				4.2
	Michigan	482				3.9			436				3.9
	Ohio	481				3.9			418				3.8
	Florida	479				3.8			419				3.8
	Other States	4,775				38.2			4,118				37
	Total other loans (including PCI loans)	$	12,473			100	%		$	11,108			100	%

Credit_Card_and_Student_Loan_S1

Credit Card and Student Loan Securitization Activities (Tables)	12 Months Ended
	Dec. 31, 2013
Variable Interest Entities Disclosure [Abstract]	'
Schedule of Restricted Credit Card Securitized Assets	'
	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 consolidated statement of financial condition as relating to securitization activities, are shown in the table below (dollars in millions):
		December 31,
		2013			2012
	Cash collateral accounts	$	59		$	93
	Collections and interest funding accounts	31			91
	Restricted cash	90			184
	Investors’ interests held by third-party investors	15,190			13,768
	Investors’ interests held by wholly owned subsidiaries of Discover Bank	5,024			5,038
	Seller’s interest	10,898			15,976
	Loan receivables(1)	31,112			34,782
	Allowance for loan losses allocated to securitized loan receivables(1)	(833		)	(1,110		)
	Net loan receivables	30,279			33,672
	Other	34			29
	Carrying value of assets of consolidated variable interest entities	$	30,403		$	33,885
	-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 December 31, 2013 (dollars in millions):
		Investors’			# of Series
		Interests(1)			Outstanding
	Discover Card Master Trust I	$	918		2
	Discover Card Execution Note Trust (DiscoverSeries notes)	19,296			37
	Total investors’ interests	$	20,214		39
	-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	14.17	%
	DiscoverSeries excess spread percentage	14.15	%
	-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	'
	The carrying values of these restricted assets, which are presented on the Company’s consolidated statements of financial condition as relating to securitization activities, are shown in the table below (dollars in millions):
		December 31,
		2013			2012
	Restricted cash	$	89		$	96
	Student loan receivables	2,248			2,539
	Allowance for loan losses allocated to securitized loan receivables(1)	(28		)	—
	Net student loan receivables	2,220			2,539
	Carrying value of assets of consolidated variable interest entities	$	2,309		$	2,635
	-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.

Premises_and_Equipment_Premise

Premises and Equipment Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Schedule of Premises and Equipment	'
	A summary of premises and equipment, net is as follows (dollars in millions):
		December 31,
		2013			2012
	Land	$	43		$	42
	Buildings and improvements	547			517
	Capitalized equipment leases	2			2
	Furniture, fixtures and equipment	735			640
	Software	391			414
	Premises and equipment	1,718			1,615
	Less: Accumulated depreciation	(829		)	(764		)
	Less: Accumulated amortization of software	(235		)	(313		)
	Premises and equipment, net	$	654		$	538

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Schedule of Intangible Assets	'
	The following table summarizes the Company's intangible assets (dollars in millions):
				December 31,
				2013						2012
		Weighted Average Amortization Period		Gross Carrying Amount		Accumulated Amortization		Net		Gross Carrying Amount		Accumulated Amortization		Net
								Book Value						Book Value
	Amortizable intangible assets:
	Customer relationships	13.7 years		$	78	$	60	$	18	$	72	$	52	$	20
	Trade name and other	25 years		8		2		6		8		2		6
	Proprietary software	7 years		6		2		4		6		1		5
	Non-compete agreements	3 years		2		1		1		2		—		2
	Marketing agreements and other	13 months		6		5		1		4		3		1
	Total amortizable intangible assets			100		70		30		92		58		34
	Non-amortizable intangible assets:
	Trade names	N/A		132		—		132		132		—		132
	International transaction processing rights	N/A		23		—		23		23		—		23
	Total non-amortizable intangible assets			155		—		155		155		—		155
	Total intangible assets			$	255	$	70	$	185	$	247	$	58	$	189
Schedule of Expected Intangible Asset Amortization Expense	'
	The following table presents expected intangible asset amortization expense for the next five years based on intangible assets at December 31, 2013 (dollars in millions):
	Year	Amount
	2014	$	9
	2015	$	5
	2016	$	4
	2017	$	3
	2018	$	3

Deposits_Tables

Deposits (Tables)	12 Months Ended
	Dec. 31, 2013
Deposits [Abstract]	'
Schedule of Interest Bearing Deposit Accounts	'
	A summary of interest-bearing deposit accounts is as follows (dollars in millions):
		December 31,
		2013			2012
	Certificates of deposit in amounts less than $100,000(1)	$	21,211		$	21,070
	Certificates of deposit from amounts of $100,000(1) to less than $250,000(1)	4,860			5,508
	Certificates of deposit in amounts of $250,000(1) or greater	1,180			1,280
	Savings deposits, including money market deposit accounts	17,515			14,219
	Total interest-bearing deposits	$	44,766		$	42,077
	Average annual interest rate	1.57		%	1.74		%
	-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 December 31, 2013, certificates of deposit maturing over the next five years, and thereafter were as follows (dollars in millions):
	Year	Amount
	2014	$	12,226
	2015	$	6,301
	2016	$	3,475
	2017	$	2,198
	2018	$	1,691
	Thereafter	$	1,360

LongTerm_Borrowings_Tables

Long-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2013
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):
		December 31,
		2013				2012
		Outstanding		Interest		Outstanding		Interest		Interest Rate Terms	Maturity
				Rate				Rate
	Securitized Debt
	Fixed rate asset-backed securities
	Principal value	$	5,549	1.86	%	$	4,549	2.87	%	Various fixed rates	Various
	(including discount of $1 at December 31, 2013 and December 31, 2012)										February 2015 - July 2019
	Fair value adjustment(1)	5				6
	Book value	5,554				4,555
	Floating rate asset-backed securities	9,140		0.46	%	8,468		0.5	%	1-month LIBOR (2) +	Various
										8 to 58 basis points	February 2014 - October 2018
	Floating rate asset-backed securities	500		0.44	%	750		0.64	%	Commercial Paper	Mar-14
										rate + 30 basis points
	Total Discover Card Master Trust I and Discover Card Execution Note Trust	15,194				13,773
	Floating rate asset-backed securities	1,005		0.48	%	1,199		0.56	%	3-month LIBOR (2) +	Various
	(including discount of $129 and $173 at December 31, 2013 and December 31, 2012, respectively)									12 to 45 basis points	January 2019 - July 2036 (3)
	Floating rate asset-backed securities	434		4.25	%	528		4.25	%	Prime rate + 100 basis points	June 2031 (3)
	(including discount of $3 at December 31, 2013 and December 31, 2012)
	Floating rate asset-backed securities	105		4	%	126		4	%	Prime rate +	July 2042 (3)
	(including premium of $1 and $2 at December 31, 2013 and December 31, 2012, respectively)									75 basis points
	Floating rate asset-backed securities	248		3.66	%	307		3.71	%	1-month LIBOR (2) +	July 2042 (3)
	(including premium of $3 and $5 at December 31, 2013 and December 31, 2012, respectively)									350 basis points
	Total SLC Private Student Loan Trusts	1,792				2,160
	Total long-term borrowings – owed to securitization investors	16,986				15,933
	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)	13				21
	Book value	413				421
	Fixed rate senior notes due 2019	78		10.25	%	78		10.25	%	Fixed	Jul-19
	Fixed rate senior notes due 2022	219		5.2	%	211		5.2	%	Fixed	Apr-22
	(including discount of $103 and $110 at December 31, 2013 and December 31, 2012, respectively)
	Fixed rate senior notes due 2022	335		3.85	%	324		3.85	%	Fixed	Nov-22
	(including discount of $165 and $176 at December 31, 2013 and December 31, 2012, respectively)
	Discover Bank
	Senior bank notes due 2018	750		2	%	—		—	%	Fixed	Feb-18
	Senior bank notes due 2023	994		4.2	%	—		—	%	Fixed	Aug-23
	(including discount of $6 at December 31, 2013)
	Subordinated bank notes due 2019	200		8.7	%	200		8.7	%	Fixed	November 2019
	Subordinated bank notes due 2020	498		7	%	497		7	%	Fixed	April 2020
	(including discount of $2 and $3 at December 31, 2013 and December 31, 2012, respectively)
	Capital lease obligations	1		4.51	%	2		4.51	%	Fixed	Apr-16
	Total long-term borrowings	$	20,474			$	17,666
	-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 22: 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.
Schedule of Long-Term Borrowings Maturities	'
	Long-term borrowings had the following maturities at December 31, 2013 (dollars in millions):
	Year	Amount
	Due in 2014	$	4,290
	Due in 2015	3,305
	Due in 2016	3,050
	Due in 2017	2,062
	Due in 2018	2,650
	Thereafter	5,117
	Total	$	20,474

StockBased_Compensation_Plans_

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Schedule of Stock-Based Compensation Plans Compensation cost, Net of Forfeitures	'
	The following table details the compensation cost, net of forfeitures (dollars in millions):
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011
	Restricted stock units	$	31		$	29		$	34		$	2
	Performance stock units	28			18			10			1
	Total stock-based compensation expense	$	59		$	47		$	44		$	3
	Income tax benefit	$	22		$	18		$	17		$	1
Schedule of Restricted Stock Unit Activity	'
	The following table sets forth the activity related to vested and unvested RSUs during the calendar year ended December 31, 2013 and one month ended December 31, 2012:
		Number of Units		Weighted-Average Grant-Date Fair Value			Aggregate
							Intrinsic Value
							(in millions)
	Restricted stock units at November 30, 2012	4,771,746		$	21.01
	Granted	2,425		$	41.23
	Conversions to common stock	—		$	—
	Forfeited	—		$	—
	Restricted stock units at December 31, 2012	4,774,171		$	21.02		$	181
	Granted	998,263		$	42.14
	Conversions to common stock	(1,565,574	)	$	17.33
	Forfeited	(62,945	)	$	26.83
	Restricted stock units at December 31, 2013	4,143,915		$	27.38		$	232
	The following table sets forth the activity related to unvested RSUs during the calendar year ended December 31, 2013 and one month ended December 31, 2012:
		Number of Units		Weighted-Average Grant-Date Fair Value
	Unvested restricted stock units at November 30, 2012(1)	2,964,707		$	19.62
	Granted	2,425		$	41.23
	Vested	—		$	—
	Forfeited	—		$	—
	Unvested restricted stock units at December 31, 2012(1)	2,967,132		$	19.64
	Granted	998,263		$	42.14
	Vested	(1,404,830	)	$	19.41
	Forfeited	(62,945	)	$	26.83
	Unvested restricted stock units at December 31, 2013(1)	2,497,620		$	28.52
	-1	Unvested restricted stock units represent awards where recipients have yet to satisfy either explicit vesting terms or retirement-eligibility requirements.
Schedule of Intrinsic Value of RSUs Converted to Common Stock and Grant Date Fair Value of RSUs Vested	'
	The following table summarizes the total intrinsic value of the RSUs converted to common stock and the total grant date fair value of RSUs vested (dollars in millions, except weighted average grant date fair value amounts):
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011
	Intrinsic value of RSUs converted to common stock	$	63		$	49		$	30		$	—
	Grant date fair value of RSUs vested	$	27		$	28		$	35		$	—
	Weighted average grant date fair value of RSUs granted	$	42.14		$	25.64		$	19.57		$	41.23
Schedule of Peformance Stock Unit Activity	'
	The following table sets forth the activity related to vested and unvested PSUs during the calendar year ended December 31, 2013 and one month ended December 31, 2012:
		Number of Units		Weighted Average Grant-Date Fair Value			Aggregate Intrinsic Value (in millions)
	Performance stock units at November 30, 2012	1,332,296		$	21.74
	Granted	—		$	—
	Conversions to common stock	—		$	—
	Forfeited	—		$	—
	Performance stock units at December 31, 2012	1,332,296		$	21.74		$	51
	Granted	581,520		$	38.89
	Conversions to common stock	—		$	—
	Forfeited	(15,949	)	$	29.2
	Performance stock units at December 31, 2013	1,897,867		$	26.93		$	106
	The following table sets forth the activity related to unvested PSUs during the calendar year ended December 31, 2013 and one month ended December 31, 2012:
		Number of Units		Weighted-Average Grant-Date Fair Value
	Unvested performance stock units at November 30, 2012	1,187,306		$	22.06
	Granted	—		$	—
	Vested(1)	—		$	—
	Forfeited	—		$	—
	Unvested performance stock units at December 31, 2012	1,187,306		$	22.06
	Granted	581,520		$	38.89
	Vested(1)	(100,585	)	$	24.39
	Forfeited	(15,949	)	$	29.2
	Unvested performance stock units at December 31, 2013(2)(3)(4)	1,652,292		$	27.77
	-1	Vested performance stock units represent awards where recipients have satisfied retirement-eligibility requirements.
	-2	Includes 559,114 performance stock units granted in fiscal year 2011 that are earned based on the Company's achievement of EPS during the two-year performance period ended November 30, 2012 and are subject to the requisite service period which ended January 2, 2014.
	-3	Includes 518,438 performance stock units granted in fiscal year 2012 that are earned based on the Company's achievement of EPS during the two-year performance period ended November 30, 2013 and are subject to the requisite service period which ends January 2, 2015.
	-4	Includes 574,740 performance stock units granted in calendar year 2013 that may be earned based on the Company's achievement of EPS during the three-year performance period which ends December 31, 2015 and are subject to the requisite service period which ends February 1, 2016.
Schedule of Stock Option Activity	'
	The following table sets forth the activity concerning stock option activity during the calendar year ended December 31, 2013 and one month ended December 31, 2012:
		Number of Units		Weighted Average Exercise Price			Weighted-Average Remaining Contractual Term		Aggregate Intrinsic Value (in millions)
							(in years)
	Options outstanding at November 30 2012	840,146		$	20.11		1.75 years
	Granted(1)	—		$	—
	Exercised	(301,677	)	$	18.87
	Expired	—		$	—
	Options outstanding at December 31, 2012	538,469		$	20.82		1.92 years		$	10
	Granted(1)	—		—
	Exercised	(366,743	)	$	18.46
	Expired	—		$	—
	Options outstanding at December 31, 2013	171,726		$	25.82		2.76 years		$	5
	Vested and exercisable at December 31, 2013	171,726		$	25.82		2.76 years		$	5
	-1	No stock options have been granted by the Company since its spin-off from Morgan Stanley.
Schedule of Intrinsic Value of Options Exercised and Fair Value of Options Vested	'
	The following table summarizes the total intrinsic value of options exercised and total fair value of options vested (dollars in millions):
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011
	Intrinsic value of options exercised	$	11		$	22		$	9		$	6

Employee_Benefit_Plans_Employe

Employee Benefit Plans Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]	'
Schedule of Net Periodic Benefit Cost	'
	Net periodic benefit cost expensed by the Company included the following components (dollars in millions):
		Pension															Postretirement
		For the Calendar Year Ended December 31, 2013				For the Fiscal Years Ended November 30,							For the One Month Ended December 31, 2012				For the Calendar Year Ended December 31, 2013				For the Fiscal Years Ended November 30,					For the One Month Ended December 31, 2012
						2012				2011											2012			2011
	Service cost, benefits earned during the period	$	—			$	—			$	—		$	—			$	—			$	1		$	1	$	—
	Interest cost on projected benefit obligation	21				21				21			2				1				2			1		—
	Expected return on plan assets	(23		)		(23		)		(23		)	(2		)		—				—			—		—
	Net amortization	5				3				1			—				(1		)		—			—		—
	Net periodic benefit cost (income)	$	3			$	1			$	(1	)	$	—			$	—			$	3		$	2	$	—
Schedule of Pretax Amounts Recognized in AOCI Not Recognized as Components of Net Periodic Benefit Cost	'
	As of December 31, 2013, pretax amounts recognized in accumulated other comprehensive income that have not yet been recognized as components of net periodic benefit cost consist of (dollars in millions):
		Pension				Postretirement
	Prior service credit (cost)	$	7			$	(1	)
	Net (loss) gain	(186		)		18
	Total	$	(179	)		$	17
Schedule of Funded Status and Changes in Benefit Obligations and Fair Value of Plan Assets	'
	The following table provides a reconciliation of the changes in the benefit obligation and fair value of plan assets as well as a summary of the Company’s funded status (dollars in millions):
		Pension								Postretirement
		For the Calendar Year Ended December 31, 2013				For the One Month Ended December 31, 2012				For the Calendar Year Ended December 31, 2013			For the One Month Ended December 31, 2012
	Reconciliation of benefit obligation:
	Benefit obligation at beginning of year	$	523			$	535			$	13		$	13
	Service cost	—				—				—			—
	Interest cost	21				2				1			—
	Employee contributions	—				—				1			—
	Actuarial (gain) loss	(78		)		(13		)		(1		)	—
	Plan amendments	—				—				—			—
	Benefits paid	(14		)		(1		)		(1		)	—
	Benefit obligation at end of year	$	452			$	523			$	13		$	13
	Reconciliation of fair value of plan assets:
	Fair value of plan assets at beginning of year	$	368			$	368			$	—		$	—
	Actual return on plan assets	13				1				—			—
	Employer contributions	—				—				—			—
	Employee contributions	—				—				1			—
	Benefits paid	(14		)		(1		)		(1		)	—
	Fair value of plan assets at end of year	$	367			$	368			$	—		$	—
	Funded status (recorded in accrued expenses and other liabilities)	$	(85	)		$	(155	)		$	(13	)	$	(13	)
Schedule of Assumptions Used to Determine Benefit Obligations and Net Periodic Benefit Cost	'
	The following table presents the assumptions used to determine benefit obligations:
		Pension						Postretirement
		31-Dec-13			31-Dec-12			31-Dec-13			31-Dec-12
	Discount rate	4.93	%		4.09	%		4.29	%		4.09	%
	The following table presents the assumptions used to determine net periodic benefit cost:
		Pension											Postretirement
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011								2012			2011
	Discount rate	4.09	%		5.07	%		5.64	%		3.96	%	4.09	%		5.07	%		5.64	%		3.96	%
	Expected long-term rate of return on plan assets	6.75	%		6.75	%		6.75	%		6.75	%	N/A			N/A			N/A			N/A
Schedule of Assumed Health Care Cost Trend Rates Used to Determine the Postretirement Benefit Obligations	'
	The following table presents assumed health care cost trend rates used to determine the postretirement benefit obligations:
		31-Dec-13			31-Dec-12
	Health care cost trend rate assumed for next year:
	Medical	6.90%-7.30%			6.90%-7.40%
	Prescription	6.90%-7.30%			8.4	%
	Rate to which the cost trend rate is assumed to decline (ultimate trend rate)	5	%		5	%
	Year that the rate reaches the ultimate trend rate	2027			2027
Schedule of Pension Plan Assets by Level Within the Fair Value Hierarchy	'
	The Discover Pension Plan’s assets are stated at fair value. Quoted market prices in active markets are the best evidence of fair value and are used as the basis for the measurement, if available. If a quoted market price is not available, the estimate of the fair value is based on the best information available in the circumstances. The table below presents information about the Discover Pension Plan assets and indicates the level within the fair value hierarchy, as defined by ASC 820, with which each item is associated. For a description of the fair value hierarchy, see Note 21: Fair Value Measurements and Disclosures. (dollars in millions):
		31-Dec-13
		Level 1				Level 2				Level 3			Total				Net Asset Allocation
	Assets
	Registered Investment Company
	Domestic small/mid cap equity fund	$	—			$	32			$	—		$	32			9	%
	Emerging markets equity fund	—				29				—			29				8
	Global low volatility equity fund	—				19				—			19				5
	International core equity fund	—				46				—			46				13
	Common Collective Trusts:
	Domestic large cap equity fund	—				50				—			50				13
	Domestic fixed income fund	—				7				—			7				2
	Long duration fixed income fund	—				181				—			181				49
	Temporary investment fund	—				3				—			3				1	%
	Total assets	$	—			$	367			$	—		$	367			100	%
		31-Dec-12
		Level 1				Level 2				Level 3			Total				Net Asset Allocation
	Assets
	Fixed income securities - U.S. treasuries	$	47			$	—			$	—		$	47			13	%
	Fixed income securities - corporate debt	—				151				—			151				41
	Registered Investment Company:
	International equity fund	24				—				—			24				6
	Common Collective Trusts:
	International equity fund	—				63				—			63				17
	Domestic large cap equity fund	—				68				—			68				19
	Domestic small cap equity fund	—				11				—			11				3
	Temporary investment fund	—				4				—			4				1
	Total assets	$	71			$	297			$	—		$	368			100	%
Schedule of Expected Benefit Payments for Next Five Years and Thereafter	'
	Expected benefit payments associated with the Company’s pension and postretirement benefit plans for the next five years and in aggregate for the years thereafter are as follows (dollars in millions):
		Pension				Postretirement
	2014	$	12			$	1
	2015	$	13			$	1
	2016	$	13			$	1
	2017	$	14			$	1
	2018	$	15			$	1
	Following five years thereafter	$	94			$	6

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2013
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, Net of Tax			Gain (Loss) on Cash Flow Hedges, Net of Tax			Foreign Currency Translation Adjustments, Net of Tax(4)			Pension and Post Retirement Plan Gain (Loss), Net of Tax			Accumulated Other Comprehensive Income (Loss)
	Balance at November 30, 2010	$	8		$	2		$	—		$	(93	)	$	(83	)
	Net unrealized gains on investment securities, net of tax expense of $28(1)	47			—			—			—			47
	Unrealized gains on cash flow hedges, net of tax expense of $3(2)	—			5			—			—			5
	Unrealized pension and postretirement plan loss, net of tax benefit of $12(3)	—			—			—			(21		)	(21		)
	Balance at November 30, 2011	55			7			—			(114		)	(52		)
	Net unrealized gains on investment securities, net of tax expense of $11(1)	19			—			—			—			19
	Unrealized losses on cash flow hedges, net of tax benefit of $2(2)	—			(4		)	—			—			(4		)
	Unrealized pension and postretirement plan loss, net of tax benefit of $25(3)	—			—			—			(38		)	(38		)
	Balance at November 30, 2012	74			3			—			(152		)	(75		)
	Net unrealized losses on investment securities, net of tax benefit of $2(1)	(3		)	—			—			—			(3		)
	Unrealized pension and postretirement plan gain, net of tax expense of $4(3)	—			—			—			6			6
	Balance at December 31, 2012	71			3			—			(146		)	(72		)
	Net change(5)	(52		)	10			1			45			4
	Balance at December 31, 2013	$	19		$	13		$	1		$	(101	)	$	(68	)
	-1	Represents the difference between the fair value and amortized cost of available-for-sale investment securities.
	-2	Represents unrealized gains (losses) related to effective portion of cash flow hedges.
	-3	Reflects adjustments to the funded status of pension and postretirement plans, which is the difference between the fair value of the plan assets and the projected benefit obligation.
	-4	Includes unrealized losses on hedge of net investment in foreign subsidiary, net of tax benefit and net gains on foreign currency translation adjustments.
	-5	In February 2013, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. ASU 2013-02 requires an entity to report the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in the consolidated statements of income if the amount being reclassified is required to be reclassified in its entirety to net income. For amounts that are not required to be reclassified to net income in their entirety in the same reporting period, an entity is required to cross-reference other disclosures that provide additional detail about those amounts. As the result, the Company has adjusted its AOCI presentation prospectively, as required, and therefore additional table was included to present the required information for the current period and the presentation has changed from historical periods.
	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):
		For the Calendar Year Ended December 31, 2013
		Before Tax			Tax (Expense) Benefit			Net of Tax
	Available-for-Sale Investment Securities:
	Net unrealized holding losses arising during the period	$	(80	)	$	30		$	(50	)
	Amounts reclassified from accumulated other comprehensive income	(2		)	—			(2		)
	Net change	$	(82	)	$	30		$	(52	)
	Cash Flow Hedges:
	Net unrealized gains arising during the period	$	8		$	(3	)	$	5
	Amounts reclassified from accumulated other comprehensive income	8			(3		)	5
	Net change	$	16		$	(6	)	$	10
	Foreign Currency Translation Adjustments:
	Net unrealized gains arising during the period	$	1		$	—		$	1
	Net change	$	1		$	—		$	1
	Pension and Postretirement Plan:
	Unrealized gains arising during the period	$	72		$	(27	)	$	45
	Net change	$	72		$	(27	)	$	45

Recovered_Sheet1

Other Income And Other Expense (Tables)	12 Months Ended
	Dec. 31, 2013
Other Income and Expenses [Abstract]	'
Schedule of Other Income	'
	Total other income includes the following components (dollars in millions):
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,				For the One Month Ended December 31, 2012
					2012		2011
	Royalty and licensee revenue	$	68		$	72	$	72	$	6
	Merchant fees	44			17		16		3
	Transition service agreement revenue	6			12		27		1
	Gain from sales of merchant contracts	—			3		11		—
	Other income	51			59		53		9
	Total other income	$	169		$	163	$	179	$	19
Schedule of Other Expense	'
	Total other expense includes the following components (dollars in millions):
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,				For the One Month Ended December 31, 2012
					2012		2011
	Postage	$	86		$	85	$	82	$	7
	Fraud losses	110			93		72		9
	Supplies	26			22		23		2
	Credit related inquiry fees	19			20		17		1
	Litigation expense	(12		)	218		22		—
	Incentive expense	61			59		23		5
	Other expense	198			107		101		11
	Total other expense	$	488		$	604	$	340	$	35

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Schedule of Income Tax Expense	'
	Income tax expense consisted of the following (dollars in millions):
		For the Calendar Year Ended December 31, 2013				For the Fiscal Years Ended November 30,							For the One Month Ended December 31, 2012
						2012				2011
	Current:
	U.S. federal	$	1,059			$	1,109			$	931		$	101
	U.S. state and local	87				149				118			15
	International	6				4				3			—
	Total	1,152				1,262				1,052			116
	Deferred:
	U.S. federal	295				136				228			(11		)
	U.S. state and local	27				10				4			(1		)
	Total	322				146				232			(12		)
	Income tax expense	$	1,474			$	1,408			$	1,284		$	104
Schedule of Reconciliation the Effective Tax Rate to the U.S. Federal Statutory Income Tax Rate	'
	The following table reconciles the Company’s effective tax rate to the U.S. federal statutory income tax rate:
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011
	U.S. federal statutory income tax rate	35	%		35	%		35	%		35	%
	U.S. state, local and other income taxes, net of U.S. federal income tax benefits	2.2			2.9			2.4			3.2
	Valuation allowance - capital loss	—			—			(0.6	)		—
	Other	0.2			(0.4	)		(0.2	)		(0.1	)
	Effective income tax rate	37.4	%		37.5	%		36.6	%		38.1	%
Schedule of Deferred Tax Assets and Liabilities	'
	Deferred income taxes reflect the net tax effects of temporary differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when such differences are expected to reverse. Valuation allowances are provided to reduce deferred tax assets to an amount that is more likely than not to be realized. The Company evaluates the likelihood of realizing its deferred tax assets by estimating sources of future taxable income and the impact of tax planning strategies. Significant components of the Company’s net deferred income taxes, which are included in other assets in the consolidated statements of financial condition, were as follows (dollars in millions):
		December 31,
		2013				2012
	Deferred tax assets:
	Allowance for loan losses	$	627			$	673
	Customer fees and rewards	212				372
	Compensation and benefits	87				104
	State income taxes	65				71
	Legal reserves	13				83
	Other	59				37
	Total deferred tax assets before valuation allowance	1,063				1,340
	Valuation allowance	(37		)		—
	Total deferred tax assets, net of valuation allowance	1,026				1,340
	Deferred tax liabilities:
	Debt exchange premium	(98		)		(107		)
	Depreciation and software amortization	(83		)		(60		)
	Unearned income	(40		)		(38		)
	Intangibles	(22		)		(22		)
	Deferred loan acquisition costs	(16		)		(12		)
	Unrealized gain/ loss	(8		)		(15		)
	Other	(5		)		(11		)
	Total deferred tax liabilities	(272		)		(265		)
	Net deferred tax assets	$	754			$	1,075
Schedule of Reconciliation of Beginning and Ending Unrecognized Tax Benefits	'
	A reconciliation of beginning and ending unrecognized tax benefits is as follows (dollars in millions):
		For the Calendar Year Ended December 31, 2013				For the Fiscal Years Ended November 30,							For the One Month Ended December 31, 2012
						2012				2011
	Balance at beginning of period	$	575			$	507			$	373		$	573
	Additions:
	Current year tax positions	1				74				74			2
	Prior year tax positions	142				1				154			—
	Reductions:
	Prior year tax positions	(69		)		(5		)		(83		)	—
	Settlements with taxing authorities	(18		)		(2		)		(9		)	—
	Expired statute of limitations	(2		)		(2		)		(2		)	—
	Balance at end of period(1)	$	629			$	573			$	507		$	575
	-1	At December 31, 2013, November 30, 2012 and 2011 and December 31, 2012, amounts included $142 million, $108 million, $97 million and $109 million respectively, of unrecognized tax benefits, which, if recognized, would favorably affect the effective tax rate.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2013
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 Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011
	Numerator:
	Net income	$	2,470		$	2,345		$	2,227		$	170
	Preferred stock dividends	(37		)	(5		)	—			—
	Net income available to common stockholders	2,433			2,340			2,227			170
	Income allocated to participating securities	(19		)	(22		)	(25		)	(2		)
	Net income allocated to common stockholders	$	2,414		$	2,318		$	2,202		$	168
	Denominator:
	Weighted average shares of common stock outstanding	485			519			542			498
	Effect of dilutive common stock equivalents	2			1			1			1
	Weighted average shares of common stock outstanding and common stock equivalents	487			520			543			499
	Basic earnings per common share	$	4.97		$	4.47		$	4.06		$	0.34
	Diluted earnings per common share	$	4.96		$	4.46		$	4.06		$	0.34

Capital_Adequacy_Tables

Capital Adequacy (Tables)	12 Months Ended
	Dec. 31, 2013
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 as of December 31, 2013 and 2012 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
	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%
	December 31, 2012
	Total capital (to risk-weighted assets)
	Discover Financial Services	$	10,998	16.8	%	$	5,242	≥8.0%	$	6,552	≥10.0%
	Discover Bank	$	9,615	14.9	%	$	5,172	≥8.0%	$	6,465	≥10.0%
	Tier 1 capital (to risk-weighted assets)
	Discover Financial Services	$	9,470	14.5	%	$	2,621	≥4.0%	$	3,931	≥6.0%
	Discover Bank	$	8,097	12.5	%	$	2,586	≥4.0%	$	3,879	≥6.0%
	Tier 1 capital (to average assets)
	Discover Financial Services	$	9,470	12.7	%	$	2,987	≥4.0%	$	3,734	≥5.0%
	Discover Bank	$	8,097	11	%	$	2,936	≥4.0%	$	3,670	≥5.0%

Commitments_Contingencies_and_1

Commitments, Contingencies and Guarantees (Tables)	12 Months Ended
	Dec. 31, 2013
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 2022. At December 31, 2013, 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	$	1	$	15
	2015	—		11
	2016	—		10
	2017	—		9
	2018	—		6
	Thereafter	—		7
	Total minimum lease payments	1		$	58
	Less: Amount representing interest	—
	Present value of net minimum lease payments	$	1
Schedule of Settlement Withholdings and Escrow Deposits	'
	The Company did not record any contingent liability in the consolidated financial statements for merchant chargeback guarantees on December 31, 2013 and 2012. 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 consolidated statements of financial condition (dollars in millions):
		December 31,
		2013		2012
	Settlement withholdings and escrow deposits	$	17	$	25
Counterparty Settlement Guarantees [Member]	'
Guarantor Obligations [Line Items]	'
Schedule of Maximum Potential Counterparty Exposures Related to Settlement Guarantees and Merchant Chargeback Guarantee	'
	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):
		December 31,
		2013
	Diners Club:
	Merchant guarantee	$	144
	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 Calendar Year Ended December 31, 2013		For the Fiscal Years Ended November 30,				For the One Month Ended December 31, 2012
				2012		2011
	Aggregate sales transaction volume(1)	$	120,442	$	114,847	$	108,225	$	11,521
	-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)	12 Months Ended
	Dec. 31, 2013
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 Active Markets		Significant Other Observable Inputs				Significant Unobservable Inputs				Total
		for Identical Assets		(Level 2)				(Level 3)
		(Level 1)
	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
	Balance at December 31, 2012
	Assets
	U.S. Treasury securities	$	2,459	$	—			$	—			$	2,459
	U.S. government agency securities	2,233		—				—				2,233
	Credit card asset-backed securities of other issuers	—		151				—				151
	Residential mortgage-backed securities - Agency	—		1,302				—				1,302
	Available-for-sale investment securities	$	4,692	$	1,453			$	—			$	6,145
	Mortgage loans held for sale	$	—	$	355			$	—			$	355
	Interest rate lock commitments	$	—	$	—			$	12			$	12
	Forward delivery contracts	—		1				—				1
	Other derivative financial instruments	—		98				—				98
	Derivative financial instruments	$	—	$	99			$	12			$	111
	Liabilities
	Forward delivery contracts	$	—	$	2			$	—			$	2
	Other derivative financial instruments	—		1				—				1
	Derivative financial instruments	$	—	$	3			$	—			$	3
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). There were no Level 3 assets or liabilities measured at fair value on a recurring basis at any point during the fiscal year ended November 30, 2011.
	For the Calendar Year Ended December 31, 2013
		Balance at December 31, 2012		Transfers into			Transfers out of Level 3			Total net gains (losses) included in earnings			Purchases			Sales		Settlements		Transfers of IRLCs to closed loans		Balance at December 31, 2013
				Level 3
	Interest rate lock commitments	$	12	—			—			121			—			—		3		(132	)	$	4
	Forward delivery contracts	$	—	—			(3	)		3			—			—		—		—		$	—
	Mortgage loans held for sale	$	—	3			—			—			1			(3	)	(1	)	—		$	—
	For the Fiscal Year Ended November 30, 2012
		Balance at November 30, 2011		Transfers into			Transfers out of Level 3			Total net gains (losses) included in earnings			Purchases			Sales		Settlements		Transfers of IRLCs to closed loans		Balance at November 30, 2012
				Level 3
	Interest rate lock commitments	$	—	—			—			110			5			—		2		(102	)	$	15
	Forward delivery contracts	$	—	—			(1	)		1			—			—		—		—		$	—
	For the One Month Ended December 31, 2012
		Balance at November 30, 2012		Transfers into			Transfers out of Level 3			Total net gains (losses) included in earnings			Purchases			Sales		Settlements		Transfers of IRLCs to closed loans		Balance at December 31, 2012
				Level 3
	Interest rate lock commitments	$	15	—			—			17			—			—		1		(21	)	$	12
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 as of December 31, 2013 (dollars in millions):
		Fair Value		Valuation		Significant Unobservable Input		Ranges of Inputs						Weighted Average(1)
				Technique				Low			High
	Interest rate lock commitments	$	4	Quantitative risk models		Loan funding probability		15	%		100	%		60	%
	-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, as of December 31, 2013 and 2012 (dollars in millions):
		Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs (Level 2)				Significant Unobservable Inputs (Level 3)				Total				Carrying Value
		(Level 1)
	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
	Balance at December 31, 2012
	Assets
	U.S. Treasury securities	$	1	$	—			$	—			$	1			$	1
	States and political subdivisions of states	—		34				—				34				34
	Residential mortgage-backed securities - Agency	—		54				—				54				52
	Held-to-maturity investment securities	$	1	$	88			$	—			$	89			$	87
	Cash and cash equivalents	$	2,584	$	—			$	—			$	2,584			$	2,584
	Restricted cash	$	290	$	—			$	—			$	290			$	290
	Net loan receivables(1)	$	—	$	—			$	62,619			$	62,619			$	60,455
	Accrued interest receivables	$	—	$	500			$	—			$	500			$	500
	Liabilities
	Deposits	$	—	$	42,671			$	—			$	42,671			$	42,213
	Short-term borrowings	$	—	$	327			$	—			$	327			$	327
	Long-term borrowings - owed to securitization investors	$	—	$	14,033			$	2,337			$	16,370			$	15,933
	Other long-term borrowings	$	—	$	2,332			$	2			$	2,334			$	1,733
	Accrued interest payables	$	—	$	126			$	—			$	126			$	126
	-1	Net loan receivables excludes mortgage loans held for sale that are measured at fair value on a recurring basis.

Derivatives_and_Hedging_Activi1

Derivatives and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2013
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 statements of financial condition each is reported as of December 31, 2013 and 2012 (dollars in millions). See Note 21: Fair Value Measurements and Disclosures for a description of the valuation methodologies of derivatives. 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. Total derivative assets 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 statements of financial condition. Collateral amounts recorded in the condensed consolidated statements 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.
		December 31, 2013														December 31, 2012
								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 Expenses and Other Liabilities (At Fair Value)
		Amount				Transactions		Assets								Amount		Assets
								(At Fair										(At Fair
								Value)										Value)
	Derivatives designated as hedges:
	Interest rate swaps - cash flow hedge	$	2,650			5		$	18			$	—			$	1,750	$	5		$	—
	Interest rate swaps - fair value hedge	$	7,138			244		52				6				$	7,859	93			—
	Foreign exchange forward contract - net investment hedge(1)	$	35			1		—				—				$	—	—			—
	Derivatives not designated as hedges:
	Foreign exchange forward contracts(2)	$	44			8		—				—				$	40	—			—
	Interest rate swap(3)	$	796			1		—				—				$	1,027	—			1
	Forward delivery contracts	$	693			478		5				1				$	774	1			2
	Interest rate lock commitments(3)	$	235			1,107		4				—				$	414	12			—
	Total gross derivative assets/liabilities(4)							79				7						111			3
	Less: Collateral receivable/payable(5)							(61		)		(7		)				(92		)	—
	Total net derivative assets/liabilities							$	18			$	—					$	19		$	3
	-1	The foreign exchange forward contract has a notional amounts of EUR 26 million as of December 31, 2013.
	-2	The foreign exchange forward contracts have notional amounts of EUR 20 million, GBP 6 million, SGD 1 million and CHF 5 million as of December 31, 2013 and EUR 18 million and GBP 9 million and SGD 2 million as of December 31, 2012.
	-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 $40 million and an immaterial fair value as of December 31, 2013.
	-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 calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012 (dollars in millions):
				For the Calendar Year Ended December 31, 2013(1)			For the Fiscal Years Ended November 30,								For the One Month Ended December 31, 2012
		Location					2012				2011
	Derivatives designated as hedges:
	Interest rate swaps—cash flow hedges:
	Total gains (losses) recognized in other comprehensive income after amounts reclassified into earnings, pre-tax	Other  Comprehensive Income		$	13		$	(6	)		$	7			$	(1	)
	Total gains (losses) recognized in other comprehensive income			$	13		$	(6	)		$	7			$	(1	)
	Amount reclassified from other comprehensive income into income	Interest Income		$	4		$	7			$	8			$	1
	Amount reclassified from other comprehensive income into income	Interest Expense		(12		)	—				—				—
	Interest rate swaps—fair value hedges:
	Interest expense - ineffectiveness			(46		)	58				37				(9		)
	Interest expense - other			41			30				13				3
	Gain (loss) on interest rate swaps	Interest Expense		(5		)	88				50				(6		)
	Interest expense - ineffectiveness			51			(52		)		(30		)		10
	Interest expense - other			(6		)	(6		)		(7		)		(1		)
	Gain (loss) on hedged item	Interest Expense		45			(58		)		(37		)		9
	Total gains (losses) recognized in income			$	32		$	37			$	21			$	4
	Derivatives not designated as hedges:
	Gain (loss) on forward contracts	Other Income		$	(1	)	$	1			$	—			$	(1	)
	Gain (loss) on interest rate swaps	Other Income		(1		)	(7		)		(5		)		—
	Gain (loss) on forward delivery contracts	Other Income		4			(1		)		—				2
	Gain (loss) on interest rate lock commitments	Other Income		121			110				—				17
	Total gains (losses) on derivatives not designated as hedges recognized in income			$	123		$	103			$	(5	)		$	18
	-1	The impact of the net investment hedge on the consolidated statements of income, which arise from amounts reclassified from other comprehensive income, was immaterial for the calendar year ended December 31, 2013.

Segment_Disclosures_Tables

Segment Disclosures (Tables)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Schedule of Segment Disclosures	'
	The following table presents segment data for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012 (dollars in millions):
		Direct		Payment		Total
		Banking		Services
	For the Calendar Year Ended December 31, 2013
	Interest income
	Credit card	$	5,978	$	—	$	5,978
	Private student loans	252		—		252
	PCI student loans	272		—		272
	Personal loans	464		—		464
	Other	98		—		98
	Total interest income	7,064		—		7,064
	Interest expense	1,146		—		1,146
	Net interest income	5,918		—		5,918
	Provision for loan losses	1,069		17		1,086
	Other income	1,976		330		2,306
	Other expense	2,961		233		3,194
	Income before income tax expense	$	3,864	$	80	$	3,944
	For the Fiscal Year Ended November 30, 2012
	Interest income
	Credit card	$	5,751	$	—	$	5,751
	Private student loans	184		—		184
	PCI student loans	303		—		303
	Personal loans	363		—		363
	Other	102		—		102
	Total interest income	6,703		—		6,703
	Interest expense	1,331		—		1,331
	Net interest income	5,372		—		5,372
	Provision for loan losses	848		—		848
	Other income	1,939		342		2,281
	Other expense	2,891		161		3,052
	Income before income tax expense	$	3,572	$	181	$	3,753
	For the Fiscal Year Ended November 30, 2011
	Interest income
	Credit card	$	5,654	$	—	$	5,654
	Private student loans	115		—		115
	PCI student loans	225		—		225
	Personal loans	266		—		266
	Other	85		—		85
	Total interest income	6,345		—		6,345
	Interest expense	1,485		—		1,485
	Net interest income	4,860		—		4,860
	Provision for loan losses	1,013		—		1,013
	Other income	1,907		298		2,205
	Other expense	2,409		132		2,541
	Income before income tax expense	$	3,345	$	166	$	3,511
	For the One Month Ended December 31, 2012
	Interest income
	Credit card	$	510	$	—	$	510
	Private student loans	18		—		18
	PCI student loans	24		—		24
	Personal loans	34		—		34
	Other	9		—		9
	Total interest income	595		—		595
	Interest expense	103		—		103
	Net interest income	492		—		492
	Provision for loan losses	178		—		178
	Other income	169		31		200
	Other expense	224		16		240
	Income before income tax expense	$	259	$	15	$	274

Parent_Company_Condensed_Finan1

Parent Company Condensed Financial Information (Tables) (Parent Company [Member])	12 Months Ended
	Dec. 31, 2013
Parent Company [Member]	'
Condensed Financial Statements, Captions [Line Items]	'
Schedule of Parent Company Condensed Statements of Financial Condition	'
	Discover Financial Services
	(Parent Company Only)
	Condensed Statements of Financial Condition
		December 31,
		2013			2012
		(dollars in millions)
	Assets:
	Cash and cash equivalents	$	4		$	41
	Notes receivable from subsidiaries(1)	2,254			2,225
	Investments in subsidiaries	9,824			8,947
	Other assets	158			133
	Total assets	$	12,240		$	11,346
	Liabilities and Stockholders' Equity:
	Non-interest bearing deposit accounts	$	6		$	3
	Interest-bearing deposit accounts	7			17
	Total deposits	13			20
	Short-term borrowings from subsidiaries	146			88
	Other long-term borrowings(2)	1,045			1,035
	Accrued expenses and other liabilities	227			330
	Total liabilities	1,431			1,473
	Stockholders' equity	10,809			9,873
	Total liabilities and stockholders' equity	$	12,240		$	11,346
	-1	The Parent Company advanced $1.8 billion to Discover Bank as of December 31, 2013, which is included in notes receivables from subsidiaries. The $1.8 billion is available to the Parent for liquidity purposes.
	-2	During the 2012 fiscal year, the Company completed a private exchange offer, resulting in the exchange of $500 million outstanding aggregate principal amount of subordinated debt issued by a subsidiary for the same aggregate principal amount of new senior notes issued by the Parent. A cash premium of $176 million paid by the subsidiary to bondholders tendering its subordinated notes under the exchange offer is reported as a component of the new senior notes and is thus included in other long term borrowings of the Parent.
Schedule of Parent Company Condensed Statements of Income	'
	Discover Financial Services
	(Parent Company Only)
	Condensed Statements of Income
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011
		(dollars in millions)
	Interest income	$	22		$	22		$	23		$	2
	Interest expense	84			52			61			7
	Net interest expense	(62		)	(30		)	(38		)	(5		)
	Dividends from subsidiaries	1,600			1,500			1,375			—
	Other income	—			—			3			—
	Total income (loss)	1,538			1,470			1,340			(5		)
	Other expense
	Employee compensation and benefits	—			—			2			—
	Professional fees	3			1			—			—
	Other(1)	1			(171		)	2			—
	Total other (benefit) expense	4			(170		)	4			—
	Income (loss) before income tax (expense) benefit and equity in undistributed net income of subsidiaries	1,534			1,640			1,336			(5		)
	Income tax (expense) benefit	17			(54		)	16			2
	Equity in undistributed net income of subsidiaries	919			759			875			173
	Net income	$	2,470		$	2,345		$	2,227		$	170
	-1	During the 2012 fiscal year, the Company completed a private exchange offer, resulting in the exchange of $500 million outstanding aggregate principal amount of subordinated debt issued by a subsidiary for the same aggregate principal amount of new senior notes issued by the Parent. A cash premium of $176 million was paid by the subsidiary but is associated with the borrowings on the Parent financial statements.
Schedule of Parent Company Condensed Statements of Cash Flows	'
	Discover Financial Services
	(Parent Company Only)
	Condensed Statements of Cash Flows
		For the Calendar Year Ended December 31, 2013			For the Fiscal Years Ended November 30,						For the One Month Ended December 31, 2012
					2012			2011
		(dollars in millions)
	Cash flows from operating activities
	Net income	$	2,470		$	2,345		$	2,227		$	170
	Adjustments to reconcile net income to net cash provided by operating activities:
	Non-cash charges included in net income:
	Equity in undistributed net income of subsidiaries	(919		)	(759		)	(875		)	(173		)
	Stock-based compensation expense	59			47			44			3
	Deferred income taxes	(2		)	109			18			(1		)
	Premium on debt issuance(1)	—			(176		)	—			—
	Depreciation and amortization	19			4			—			1
	Changes in assets and liabilities:
	(Increase) decrease in other assets	(33		)	(16		)	(8		)	32
	Increase (decrease) in other liabilities and accrued expenses	29			10			(16		)	(15		)
	Net cash provided by operating activities	1,623			1,564			1,390			17
	Cash flows from investing activities
	Increase in investment in subsidiaries	—			(196		)	(8		)	(1		)
	(Increase) decrease in loans to subsidiaries	(29		)	(520		)	(877		)	57
	Net cash (used for) provided by investing activities	(29		)	(716		)	(885		)	56
	Cash flows from financing activities
	Net increase (decrease) in short-term borrowings from subsidiaries	58			1			—			(6		)
	Proceeds from issuance of common stock	13			26			23			2
	Proceeds from issuance of preferred stock	—			560			—			—
	Proceeds from advances from subsidiaries	—			93			—			—
	Purchases of treasury stock	(1,296		)	(1,216		)	(436		)	(12		)
	Net (decrease) increase in deposits	(7		)	12			18			(12		)
	Premium paid on debt exchange	—			(115		)	—			—
	Dividends paid on common and preferred stock	(399		)	(209		)	(110		)	(5		)
	Net cash used for financing activities	(1,631		)	(848		)	(505		)	(33		)
	Increase (decrease) in cash and cash equivalents	(37		)	—			—			40
	Cash and cash equivalents, at beginning of period	41			1			1			1
	Cash and cash equivalents, at end of period	$	4		$	1		$	1		$	41
	Supplemental Disclosures:
	Cash paid during the year for:
	Interest expense	$	65		$	66		$	77		$	2
	Income taxes, net of income tax refunds	$	(1	)	$	(65	)	$	11		$	—
	Significant non-cash investing and financing transactions
	Capital contribution to subsidiary(1)	$	—		$	499		$	—		$	—
	Debt issuance, net of discount(1)	$	—		$	(499	)	$	—		$	—
	-1	During the 2012 fiscal year, the Company completed a private exchange offer, resulting in the exchange of $500 million outstanding aggregate principal amount of subordinated debt issued by a subsidiary for the same aggregate principal amount of new senior notes issued by the Parent. A cash premium of $176 million was paid by the subsidiary but is associated with the borrowings on the Parent financial statements.

Transition_Period_Financial_In1

Transition Period Financial Information Transition Period Financial Information (Tables)	12 Months Ended
	Dec. 31, 2013
Transition Period Financial Information [Abstract]	'
Schedule of Transition Period Financial Information	'
	The following table presents selected financial data for the one month ended and as of December 31, 2012 and the one month ended and as of December 31, 2011 (in millions, except per share data):
		One Month Ended
		December 31,
		2012			2011
					(unaudited)
	Statement of Income Data:
	Net interest income	$	492		$	442
	Provision for loan losses	178			173
	Other income	200			211
	Other expense	240			217
	Income before income tax expense	274			263
	Income tax expense	104			99
	Net income	$	170		$	164
	Net income allocated to common stockholders	$	168		$	162
	Per Share of Common Stock:
	Basic earnings per common share	$	0.34		$	0.31
	Diluted earnings per common share	$	0.34		$	0.3
	Weighted average shares outstanding	498			529
	Weighted average shares outstanding (fully diluted)	499			530
	Statement of Financial Condition Data (as of):
	Total loan receivables	$	62,598		$	59,372
	Allowance for loan losses	$	(1,788	)	$	(2,245	)
	Total assets	$	73,491		$	69,473
	Long-term borrowings	$	17,666		$	18,265
	Total liabilities	$	63,618		$	61,115
	Total stockholders' equity	$	9,873		$	8,358

Quarterly_Results_Tables

Quarterly Results (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Data [Abstract]	'
Schedule of Quarterly Results	'
	The following table provides unaudited quarterly results. As discussed previously, the Company changed its fiscal year end from November 30 to December 31 of each year. This fiscal year change was effective January 1, 2013. As a result of the change, the Company had a one month transition period in December 2012 that is not represented in this table of quarterly results. For information on the one month transition period, see Note 26: Transition Period Financial Information (dollars in millions, except per share data):
		31-Dec-13		30-Sep-13		30-Jun-13		31-Mar-13		30-Nov-12		August 31,		May 31,		February
												2012		2012		29, 2012
	Interest income	$	1,842	$	1,787	$	1,727	$	1,708	$	1,706	$	1,695	$	1,656	$	1,646
	Interest expense	273		278		297		298		312		325		341		353
	Net interest income	1,569		1,509		1,430		1,410		1,394		1,370		1,315		1,293
	Provision for loan losses	354		333		240		159		338		126		232		152
	Gain (loss) on investments	2		—		—		3		26		—		—		—
	Other income	558		553		611		579		578		594		533		550
	Other expense	838		783		820		753		800		826		749		677
	Income before income tax expense	937		946		981		1,080		860		1,012		867		1,014
	Income tax expense	335		353		379		407		309		385		330		384
	Net income	$	602	$	593	$	602	$	673	$	551	$	627	$	537	$	630
	Net income allocated to common stockholders(1)	$	588	$	579	$	588	$	659	$	541	$	621	$	532	$	624
	Basic earnings per common share(1)	$	1.24	$	1.2	$	1.2	$	1.33	$	1.08	$	1.21	$	1.01	$	1.18
	Diluted earnings per common share(1)	$	1.23	$	1.2	$	1.2	$	1.33	$	1.07	$	1.21	$	1	$	1.18
	-1	Because the inputs to net income allocated to common stockholders and earnings per share are calculated using weighted averages for the quarter, the sum of all four quarters may differ from the year to date amounts in the consolidated statements of income.

Background_and_Basis_of_Presen2

Background and Basis of Presentation (Details)	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Consolidation percentage	50.00%
Cost method ownership percentage	20.00%

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Accounting Policies [Line Items]	'	'	'	'
Cash and due from banks	$797,000,000	$719,000,000	'	'
Interest-bearing deposits in other banks	1,800,000,000	5,800,000,000	'	'
Fraudulent transaction charge off period	'	'90 days	'	'
Advertising costs	17,000,000	208,000,000	172,000,000	150,000,000
Unamortized deferred costs for loan origination	29,000,000	43,000,000	'	'
Credit card rewards cost adjusted for estimated forfeitures	123,000,000	1,000,000,000	1,000,000,000	879,000,000
Liability for customer rewards adjusted for estimated forfeitures	1,100,000,000	1,100,000,000	'	'
Unamortized portion of the deferred incentive payments	41,000,000	23,000,000	'	'
Loan Lending Commitment Arrangement Fees [Member]	'	'	'	'
Accounting Policies [Line Items]	'	'	'	'
Deferred revenue	$34,000,000	$37,000,000	'	'
Building [Member]	'	'	'	'
Accounting Policies [Line Items]	'	'	'	'
Premises and equipment, useful life	'	'39 years	'	'
Leasehold Improvements [Member]	'	'	'	'
Accounting Policies [Line Items]	'	'	'	'
Premises and equipment, useful life	'	'10 years	'	'
Computer Equipment [Member]	'	'	'	'
Accounting Policies [Line Items]	'	'	'	'
Premises and equipment, useful life	'	'3 years	'	'
Processing Equipment [Member]	'	'	'	'
Accounting Policies [Line Items]	'	'	'	'
Premises and equipment, useful life	'	'6 years	'	'
Minimum [Member]	'	'	'	'
Accounting Policies [Line Items]	'	'	'	'
Delinquent loan qualification period	'	'30 days	'	'
Minimum [Member] | Furniture and Fixtures [Member]	'	'	'	'
Accounting Policies [Line Items]	'	'	'	'
Premises and equipment, useful life	'	'5 years	'	'
Minimum [Member] | Equipment [Member]	'	'	'	'
Accounting Policies [Line Items]	'	'	'	'
Premises and equipment, useful life	'	'3 years	'	'
Minimum [Member] | Software Development [Member]	'	'	'	'
Accounting Policies [Line Items]	'	'	'	'
Premises and equipment, useful life	'	'3 years	'	'
Maximum [Member]	'	'	'	'
Accounting Policies [Line Items]	'	'	'	'
Cash and cash equivalents maturity period	'	'90 days	'	'
Maximum [Member] | Furniture and Fixtures [Member]	'	'	'	'
Accounting Policies [Line Items]	'	'	'	'
Premises and equipment, useful life	'	'10 years	'	'
Maximum [Member] | Equipment [Member]	'	'	'	'
Accounting Policies [Line Items]	'	'	'	'
Premises and equipment, useful life	'	'10 years	'	'
Maximum [Member] | Software Development [Member]	'	'	'	'
Accounting Policies [Line Items]	'	'	'	'
Premises and equipment, useful life	'	'10 years	'	'

Business_Combinations_Narrativ

Business Combinations (Narrative) (Details)	1 Months Ended	12 Months Ended			0 Months Ended	3 Months Ended			0 Months Ended	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011	21-May-13	Jun. 30, 2013	Jun. 30, 2013	21-May-13	Jun. 06, 2012	Jun. 30, 2013
	USD ($)	USD ($)	USD ($)	USD ($)	DC Italy [Member]	DC Italy [Member]	DC Italy [Member]	DC Italy [Member]	HLC Acquisition [Member]	HLC Acquisition [Member]
					EUR (€)	USD ($)	EUR (€)	Charge Card Receivables [Member]	USD ($)	USD ($)
								USD ($)
Business Acquisition [Line Items]	'	'	'	'	'	'	'	'	'	'
Consideration paid in a business combination	'	'	'	'	€ 1	'	'	'	'	'
Capital contribution to subsidiary	'	'	'	'	'	58,000,000	45,000,000	'	'	'
Recognized identifiable assets acquired in a business combination	'	'	'	'	'	'	'	34,000,000	'	'
Consideration paid for purchase of net assets of a business	0	0	49,000,000	0	'	'	'	'	49,000,000	'
Contingent consideration paid for purchase of net assets of a business	'	'	'	'	'	'	'	'	'	$10,000,000

Investments_Narrative_Details

Investments (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Investment Holdings [Line Items]	'	'	'	'
Proceeds related to maturities, redemptions, or liquidation of investment securities	$113	$733	$1,800	$1,300
Realized gain (loss) on sales of available-for-sale securities	0	'	0	0
Unrealized (loss) gain on available-for-sale investment securities, before tax	-5	-82	30	75
Unrealized (loss) gain on available-for-sale investment securities, net of tax	-3	-52	19	47
Other than temporary impairment loss on investments	0	0	0	2
Community Reinvestment Act [Member] | Other Assets [Member]	'	'	'	'
Investment Holdings [Line Items]	'	'	'	'
Equity method investments	259	308	'	'
Community Reinvestment Act [Member] | Other Liabilities [Member]	'	'	'	'
Investment Holdings [Line Items]	'	'	'	'
Contingent liabilities related to equity method investments	79	52	'	'
US Government Agencies Debt Securities [Member] | Maturities of Available-for-sale Securities [Member]	'	'	'	'
Investment Holdings [Line Items]	'	'	'	'
Proceeds related to maturities, redemptions, or liquidation of investment securities	'	220	757	'
Residential Mortgage Backed Securities [Member] | Maturities of Available-for-sale Securities [Member]	'	'	'	'
Investment Holdings [Line Items]	'	'	'	'
Proceeds related to maturities, redemptions, or liquidation of investment securities	'	273	'	'
Asset-backed Securities, Securitized Loans and Receivables [Member] | Maturities of Available-for-sale Securities [Member]	'	'	'	'
Investment Holdings [Line Items]	'	'	'	'
Proceeds related to maturities, redemptions, or liquidation of investment securities	'	144	'	843
US Treasury Securities [Member] | Maturities of Available-for-sale Securities [Member]	'	'	'	'
Investment Holdings [Line Items]	'	'	'	'
Proceeds related to maturities, redemptions, or liquidation of investment securities	'	'	388	'
Corporate Debt Securities [Member] | Maturities of Available-for-sale Securities [Member]	'	'	'	'
Investment Holdings [Line Items]	'	'	'	'
Proceeds related to maturities, redemptions, or liquidation of investment securities	75	'	370	'
US Treasury and Government [Member]	'	'	'	'
Investment Holdings [Line Items]	'	'	'	'
Proceeds from sale of available-for-sale securities	'	719	'	'
Realized gain (loss) on sales of available-for-sale securities	'	$2	'	'

Investments_Schedule_of_Invest

Investments (Schedule of Investment Securities) (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012		Nov. 30, 2012		Nov. 30, 2011
In Millions, unless otherwise specified
Investment Holdings [Line Items]	'		'		'		'
Total investment securities	$4,991		$6,232		$6,221		$6,206
US Treasury Securities [Member]	'		'		'		'
Investment Holdings [Line Items]	'		'		'		'
Total investment securities	2,058	[1]	2,460		2,463		2,564
Derivative collateral	9		'		'		'
US Government Corporations and Agencies Securities [Member]	'		'		'		'
Investment Holdings [Line Items]	'		'		'		'
Total investment securities	1,561		2,233		2,237		2,795
US States and Political Subdivisions Debt Securities [Member]	'		'		'		'
Investment Holdings [Line Items]	'		'		'		'
Total investment securities	15		34		34		41
Total Other Securities [Member]	'		'		'		'
Investment Holdings [Line Items]	'		'		'		'
Total investment securities	1,357		1,505		1,487		806
Credit Card Asset-Backed Securities of Other Issuers [Member]	'		'		'		'
Investment Holdings [Line Items]	'		'		'		'
Total investment securities	6		151		159		300
Corporate Debt Securities [Member]	'		'		'		'
Investment Holdings [Line Items]	'		'		'		'
Total investment securities	0	[2]	0	[2]	75	[2]	450	[2]
To-be-announced Investment Securities [Member]	'		'		'		'
Investment Holdings [Line Items]	'		'		'		'
Total investment securities	0	[3]	0	[3]	0	[3]	50	[3]
Residential Mortgage Backed Securities [Member]	'		'		'		'
Investment Holdings [Line Items]	'		'		'		'
Total investment securities	$1,351	[4]	$1,354	[4]	$1,253	[4]	$6	[4]
[1]	Includes $9 million of U.S. Treasury securities that have been pledged as swap collateral in lieu of cash as of December 31, 2013.
[2]	Amount represents corporate debt obligations issued under the Temporary Liquidity Guarantee Program (TLGP) that are guaranteed by the Federal Deposit Insurance Corporation (FDIC).
[3]	The Company’s to-be-announced investment securities are forward contracts for regular-way purchases of government agency mortgage-backed securities. They are accounted for as investment securities rather than as derivative instruments. These contracts are for the purchase of mortgage-backed securities with a stated coupon and original term to maturity but for which the specific underlying mortgage loans are not known at the inception of the contract or at the end of the reporting period.
[4]	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, Gross Unrealized Losses and Fair Value) (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Investment Holdings [Line Items]	'		'
Available-for-sale investment securities, amortized cost	$4,900	[1]	$6,031	[1]
Available-for-sale investment securities, gross unrealized gains	53	[1]	114	[1]
Available-for-sale investment securities, gross unrealized losses	-22	[1]	0	[1]
Available-for-sale investment securities, fair value	4,931	[1]	6,145	[1]
Held-to-maturity investment securities, amortized cost	60	[2]	87	[2]
Held-to-maturity investment securities, gross unrealized gains	0	[2]	2	[2]
Held-to-maturity investment securities, gross unrealized losses	-2	[2]	0	[2]
Held-to-maturity securities, debt maturities, fair value	58	[2]	89	[2]
US Treasury Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale investment securities, amortized cost	2,030	[1]	2,413	[1]
Available-for-sale investment securities, gross unrealized gains	27	[1]	46	[1]
Available-for-sale investment securities, gross unrealized losses	0	[1]	0	[1]
Available-for-sale investment securities, fair value	2,057	[1]	2,459	[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 securities, debt maturities, 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	1,535	[1]	2,187	[1]
Available-for-sale investment securities, gross unrealized gains	26	[1]	46	[1]
Available-for-sale investment securities, gross unrealized losses	0	[1]	0	[1]
Available-for-sale investment securities, fair value	1,561	[1]	2,233	[1]
Asset-backed Securities, Securitized Loans and Receivables [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale investment securities, amortized cost	6	[1]	149	[1]
Available-for-sale investment securities, gross unrealized gains	0	[1]	2	[1]
Available-for-sale investment securities, gross unrealized losses	0	[1]	0	[1]
Available-for-sale investment securities, fair value	6	[1]	151	[1]
Residential Mortgage Backed Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale investment securities, amortized cost	1,329	[1]	1,282	[1]
Available-for-sale investment securities, gross unrealized gains	0	[1]	20	[1]
Available-for-sale investment securities, gross unrealized losses	-22	[1]	0	[1]
Available-for-sale investment securities, fair value	1,307	[1]	1,302	[1]
Held-to-maturity investment securities, amortized cost	44	[2],[4]	52	[2],[4]
Held-to-maturity investment securities, gross unrealized gains	0	[2],[4]	2	[2],[4]
Held-to-maturity investment securities, gross unrealized losses	-1	[2],[4]	0	[2],[4]
Held-to-maturity securities, debt maturities, fair value	43	[2],[4]	54	[2],[4]
US States and Political Subdivisions Debt Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Held-to-maturity investment securities, amortized cost	15	[2]	34	[2]
Held-to-maturity investment securities, gross unrealized gains	0	[2]	0	[2]
Held-to-maturity investment securities, gross unrealized losses	-1	[2]	0	[2]
Held-to-maturity securities, debt maturities, fair value	$14	[2]	$34	[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.

Investments_Schedule_of_Fair_V

Investments (Schedule of Fair Value of Securities in a Continuous Unrealized Loss Position for Less Than 12 Months and More Than 12 Months) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified	securities
Residential Mortgage Backed Securities [Member]	'
Investment Holdings [Line Items]	'
Available-for-sale investment securities, number of securities in a loss position (in securities)	23
Available-for-sale investment securities, continuous unrealized loss position, less than 12 months, fair value	$1,097
Available-for-sale investment securities, continuous unrealized loss position, less than 12 months, unrealized losses	-20
Available-for-sale investment securities, continuous unrealized loss position, more than 12 months, fair value	48
Available-for-sale investment securities, continuous unrealized loss position, more than 12 months, unrealized losses	-2
Held-to-maturity investment securities, number of securities in a loss position (in securities)	2
Held-to-maturity investment securities, continuous unrealized loss position, less than 12 months, fair value	40
Held-to-maturity investment securities, continuous unrealized loss position, less than 12 months, unrealized losses	-1
Held-to-maturity investment securities, continuous unrealized loss position, more than 12 months, fair value	0
Held-to-maturity investment securities, continuous unrealized loss position, more than 12 months, unrealized losses	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
Held-to-maturity investment securities, continuous unrealized loss position, less than 12 months, fair value	8
Held-to-maturity investment securities, continuous unrealized loss position, less than 12 months, unrealized losses	-1
Held-to-maturity investment securities, continuous unrealized loss position, more than 12 months, fair value	3
Held-to-maturity investment securities, continuous unrealized loss position, more than 12 months, unrealized losses	$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 $)	Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Investment Holdings [Line Items]	'		'
Available-for-sale securities, debt maturities, one year or less, amortized cost	$1,223	[1]	'
Available-for-sale securities, debt maturities, after one year through five years, amortized cost	2,348	[1]	'
Available-for-sale securities, debt maturities, after five years through ten years, amortized cost	401	[1]	'
Available-for-sale securities, debt maturities, after ten years, amortized cost	928	[1]	'
Available-for-sale securities, debt maturities, amortized cost	4,900	[1]	'
Held-to-maturity securities, debt maturities, one year or less, amortized cost	1	[2]	'
Held-to-maturity securities, debt maturities, after one year through five years, amortized cost	0	[2]	'
Held-to-maturity securities, debt maturities, after five years through ten years, amortized cost	0	[2]	'
Held-to-maturity securities, debt maturities, after ten years, amortized cost	59	[2]	'
Held-to-maturity securities, debt maturities, amortized cost	60	[2]	87	[2]
Available-for-sale securities, debt maturities, one year or less, fair value	1,228	[1]	'
Available-for-sale securities, debt maturities, after one year through five years, fair value	2,396	[1]	'
Available-for-sale securities, debt maturities, after five years through ten years, fair value	398	[1]	'
Available-for-sale securities, debt maturities, after ten years, fair value	909	[1]	'
Available-for-sale investment securities, fair value	4,931	[1]	6,145	[1]
Held-to-maturity securities, debt maturities, one year or less, fair value	1	[2]	'
Held-to-maturity securities, debt maturities, after one year through five years, fair value	0	[2]	'
Held-to-maturity securities, debt maturities, after five years through ten years, fair value	0	[2]	'
Held-to-maturity securities, debt maturities, after ten years, fair value	57	[2]	'
Held-to-maturity securities, debt maturities, fair value	58	[2]	89	[2]
Available-for-sale securities, debt maturities, one year or less, percentage	0.82%	[3]	'
Available-for-sale securities, debt maturities, after one year through five years, percentage	1.57%	[3]	'
Available-for-sale securities, debt maturities, after five years through ten years, percentage	1.44%	[3]	'
Available-for-sale securities, debt maturities, after ten years, percentage	1.96%	[3]	'
Available-for-sale securities, debt maturities, percentage	1.45%	[3]	'
Held-to-maturity securities, debt maturities, one year or less, percentage	0.08%		'
Held-to-maturity securities, debt maturities, after one year through five years, percentage	4.27%		'
Held-to-maturity securities, debt maturities, after five years though ten years, percentage	0.00%		'
Held-to-maturity securities, debt maturities, after ten years, percentage	3.63%		'
Held-to-maturity securities, debt maturities, percentage	3.60%		'
US Treasury Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale securities, debt maturities, one year or less, amortized cost	709	[1]	'
Available-for-sale securities, debt maturities, after one year through five years, amortized cost	1,321	[1]	'
Available-for-sale securities, debt maturities, after five years through ten years, amortized cost	0	[1]	'
Available-for-sale securities, debt maturities, after ten years, amortized cost	0	[1]	'
Available-for-sale securities, debt maturities, amortized cost	2,030	[1]	'
Held-to-maturity securities, debt maturities, one year or less, amortized cost	1	[2]	'
Held-to-maturity securities, debt maturities, after one year through five years, amortized cost	0	[2]	'
Held-to-maturity securities, debt maturities, after five years through ten years, amortized cost	0	[2]	'
Held-to-maturity securities, debt maturities, after ten years, amortized cost	0	[2]	'
Held-to-maturity securities, debt maturities, amortized cost	1	[2],[4]	1	[2],[4]
Available-for-sale securities, debt maturities, one year or less, fair value	711	[1]	'
Available-for-sale securities, debt maturities, after one year through five years, fair value	1,346	[1]	'
Available-for-sale securities, debt maturities, after five years through ten years, fair value	0	[1]	'
Available-for-sale securities, debt maturities, after ten years, fair value	0	[1]	'
Available-for-sale investment securities, fair value	2,057	[1]	2,459	[1]
Held-to-maturity securities, debt maturities, one year or less, fair value	1	[2]	'
Held-to-maturity securities, debt maturities, after one year through five years, fair value	0	[2]	'
Held-to-maturity securities, debt maturities, after five years through ten years, fair value	0	[2]	'
Held-to-maturity securities, debt maturities, after ten years, fair value	0	[2]	'
Held-to-maturity securities, debt maturities, fair value	1	[2],[4]	1	[2],[4]
Available-for-sale securities, debt maturities, one year or less, percentage	0.65%	[3]	'
Available-for-sale securities, debt maturities, after one year through five years, percentage	1.45%	[3]	'
Available-for-sale securities, debt maturities, after five years through ten years, percentage	0.00%	[3]	'
Available-for-sale securities, debt maturities, after ten years, percentage	0.00%	[3]	'
Available-for-sale securities, debt maturities, percentage	1.17%	[3]	'
Held-to-maturity securities, debt maturities, one year or less, percentage	0.08%		'
Held-to-maturity securities, debt maturities, after one year through five years, percentage	0.00%		'
Held-to-maturity securities, debt maturities, after five years though ten years, percentage	0.00%		'
Held-to-maturity securities, debt maturities, after ten years, percentage	0.00%		'
Held-to-maturity securities, debt maturities, percentage	0.08%		'
US Government Corporations and Agencies Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale securities, debt maturities, one year or less, amortized cost	508	[1]	'
Available-for-sale securities, debt maturities, after one year through five years, amortized cost	1,027	[1]	'
Available-for-sale securities, debt maturities, after five years through ten years, amortized cost	0	[1]	'
Available-for-sale securities, debt maturities, after ten years, amortized cost	0	[1]	'
Available-for-sale securities, debt maturities, amortized cost	1,535	[1]	'
Available-for-sale securities, debt maturities, one year or less, fair value	511	[1]	'
Available-for-sale securities, debt maturities, after one year through five years, fair value	1,050	[1]	'
Available-for-sale securities, debt maturities, after five years through ten years, fair value	0	[1]	'
Available-for-sale securities, debt maturities, after ten years, fair value	0	[1]	'
Available-for-sale investment securities, fair value	1,561	[1]	2,233	[1]
Available-for-sale securities, debt maturities, one year or less, percentage	0.92%	[3]	'
Available-for-sale securities, debt maturities, after one year through five years, percentage	1.72%	[3]	'
Available-for-sale securities, debt maturities, after five years through ten years, percentage	0.00%	[3]	'
Available-for-sale securities, debt maturities, after ten years, percentage	0.00%	[3]	'
Available-for-sale securities, debt maturities, percentage	1.46%	[3]	'
Asset-backed Securities, Securitized Loans and Receivables [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale securities, debt maturities, one year or less, amortized cost	6	[1]	'
Available-for-sale securities, debt maturities, after one year through five years, amortized cost	0	[1]	'
Available-for-sale securities, debt maturities, after five years through ten years, amortized cost	0	[1]	'
Available-for-sale securities, debt maturities, after ten years, amortized cost	0	[1]	'
Available-for-sale securities, debt maturities, amortized cost	6	[1]	'
Available-for-sale securities, debt maturities, one year or less, fair value	6	[1]	'
Available-for-sale securities, debt maturities, after one year through five years, fair value	0	[1]	'
Available-for-sale securities, debt maturities, after five years through ten years, fair value	0	[1]	'
Available-for-sale securities, debt maturities, after ten years, fair value	0	[1]	'
Available-for-sale investment securities, fair value	6	[1]	151	[1]
Available-for-sale securities, debt maturities, one year or less, percentage	12.83%	[3]	'
Available-for-sale securities, debt maturities, after one year through five years, percentage	0.00%	[3]	'
Available-for-sale securities, debt maturities, after five years through ten years, percentage	0.00%	[3]	'
Available-for-sale securities, debt maturities, after ten years, percentage	0.00%	[3]	'
Available-for-sale securities, debt maturities, percentage	12.83%	[3]	'
Residential Mortgage Backed Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Available-for-sale securities, debt maturities, one year or less, amortized cost	0	[1]	'
Available-for-sale securities, debt maturities, after one year through five years, amortized cost	0	[1]	'
Available-for-sale securities, debt maturities, after five years through ten years, amortized cost	401	[1]	'
Available-for-sale securities, debt maturities, after ten years, amortized cost	928	[1]	'
Available-for-sale securities, debt maturities, amortized cost	1,329	[1]	'
Held-to-maturity securities, debt maturities, one year or less, amortized cost	0	[2]	'
Held-to-maturity securities, debt maturities, after one year through five years, amortized cost	0	[2]	'
Held-to-maturity securities, debt maturities, after five years through ten years, amortized cost	0	[2]	'
Held-to-maturity securities, debt maturities, after ten years, amortized cost	44	[2]	'
Held-to-maturity securities, debt maturities, amortized cost	44	[2],[5]	52	[2],[5]
Available-for-sale securities, debt maturities, one year or less, fair value	0	[1]	'
Available-for-sale securities, debt maturities, after one year through five years, fair value	0	[1]	'
Available-for-sale securities, debt maturities, after five years through ten years, fair value	398	[1]	'
Available-for-sale securities, debt maturities, after ten years, fair value	909	[1]	'
Available-for-sale investment securities, fair value	1,307	[1]	1,302	[1]
Held-to-maturity securities, debt maturities, one year or less, fair value	0	[2]	'
Held-to-maturity securities, debt maturities, after one year through five years, fair value	0	[2]	'
Held-to-maturity securities, debt maturities, after five years through ten years, fair value	0	[2]	'
Held-to-maturity securities, debt maturities, after ten years, fair value	43	[2]	'
Held-to-maturity securities, debt maturities, fair value	43	[2],[5]	54	[2],[5]
Available-for-sale securities, debt maturities, one year or less, percentage	0.00%	[3]	'
Available-for-sale securities, debt maturities, after one year through five years, percentage	0.00%	[3]	'
Available-for-sale securities, debt maturities, after five years through ten years, percentage	1.44%	[3]	'
Available-for-sale securities, debt maturities, after ten years, percentage	1.96%	[3]	'
Available-for-sale securities, debt maturities, percentage	1.80%	[3]	'
Held-to-maturity securities, debt maturities, one year or less, percentage	0.00%		'
Held-to-maturity securities, debt maturities, after one year through five years, percentage	0.00%		'
Held-to-maturity securities, debt maturities, after five years though ten years, percentage	0.00%		'
Held-to-maturity securities, debt maturities, after ten years, percentage	3.27%		'
Held-to-maturity securities, debt maturities, percentage	3.27%		'
US States and Political Subdivisions Debt Securities [Member]	'		'
Investment Holdings [Line Items]	'		'
Held-to-maturity securities, debt maturities, one year or less, amortized cost	0	[2]	'
Held-to-maturity securities, debt maturities, after one year through five years, amortized cost	0	[2]	'
Held-to-maturity securities, debt maturities, after five years through ten years, amortized cost	0	[2]	'
Held-to-maturity securities, debt maturities, after ten years, amortized cost	15	[2]	'
Held-to-maturity securities, debt maturities, amortized cost	15	[2]	34	[2]
Held-to-maturity securities, debt maturities, one year or less, fair value	0	[2]	'
Held-to-maturity securities, debt maturities, after one year through five years, fair value	0	[2]	'
Held-to-maturity securities, debt maturities, after five years through ten years, fair value	0	[2]	'
Held-to-maturity securities, debt maturities, after ten years, fair value	14	[2]	'
Held-to-maturity securities, debt maturities, fair value	$14	[2]	$34	[2]
Held-to-maturity securities, debt maturities, one year or less, percentage	0.00%		'
Held-to-maturity securities, debt maturities, after one year through five years, percentage	4.27%		'
Held-to-maturity securities, debt maturities, after five years though ten years, percentage	0.00%		'
Held-to-maturity securities, debt maturities, after ten years, percentage	4.68%		'
Held-to-maturity securities, debt maturities, percentage	4.67%		'
[1]	Available-for-sale investment securities are reported at fair value.
[2]	Held-to-maturity investment securities are reported at amortized cost.
[3]	The weighted average yield for available-for-sale investment securities is calculated based on the amortized cost.
[4]	Amount represents securities pledged as collateral to a government-related merchant for which transaction settlement occurs beyond the normal 24-hour period.
[5]	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 Interest on Investment Securities) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Investments, Debt and Equity Securities [Abstract]	'	'	'	'
Taxable interest	$7	$73	$78	$57
Tax exempt interest	0	1	2	2
Total income from investment securities	$7	$74	$80	$59

Loan_Receivables_Narrative_Det

Loan Receivables (Narrative) (Details) (USD $)

1 Months Ended

3 Months Ended

12 Months Ended

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Nov. 30, 2012

Aug. 31, 2012

31-May-12

Feb. 29, 2012

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2011

Nov. 30, 2010

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

$183,000,000

'

$110,000,000

'

'

'

'

'

'

'

$110,000,000

'

'

'

Private student loans in forbearance as a percentage of student loans in repayment and forbearance (percentage)

3.40%

'

1.90%

'

'

'

'

'

'

'

1.90%

'

'

'

Interest and fees forgiven due to credit card loan modification program

3,000,000

'

'

'

'

'

'

'

'

'

40,000,000

44,000,000

64,000,000

'

Percentage of defaulted loans that were charged off at the end of the month in which they defaulted (percentage)

39.00%

'

'

'

'

'

'

'

'

'

40.00%

46.00%

40.00%

'

Outstanding balance of purchased credit-impaired loans

5,200,000,000

'

4,600,000,000

'

'

'

'

'

'

'

4,600,000,000

'

'

'

Purchased credit-impaired loans

4,702,000,000

'

4,178,000,000

'

'

'

'

'

'

'

4,178,000,000

'

'

'

Provision for loan losses

178,000,000

173,000,000

354,000,000

333,000,000

240,000,000

159,000,000

338,000,000

126,000,000

232,000,000

152,000,000

1,086,000,000

848,000,000

1,013,000,000

'

Allowance for loan losses

1,788,000,000

2,245,000,000

1,648,000,000

'

'

'

1,725,000,000

'

'

'

1,648,000,000

1,725,000,000

2,205,000,000

3,304,000,000

30 days or more delinquency rate for purchased credit-impaired loans (rate)

2.68%

'

2.33%

'

'

'

'

'

'

'

2.33%

'

'

'

90 days or more delinquency rate for purchased credit-impaired loans (rate)

0.86%

'

0.80%

'

'

'

'

'

'

'

0.80%

'

'

'

Net charge-off rate for purchased credit-impaired loans (rate)

1.53%

'

'

'

'

'

'

'

'

'

1.36%

1.41%

1.34%

'

Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing

423,000,000

'

434,000,000

'

'

'

'

'

'

'

434,000,000

'

'

'

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

165,000,000

'

'

'

'

'

'

'

'

'

893,000,000

724,000,000

897,000,000

'

Allowance for loan losses

1,613,000,000

'

1,406,000,000

'

'

'

1,554,000,000

'

'

'

1,406,000,000

1,554,000,000

2,070,000,000

3,209,000,000

Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing

409,000,000

'

408,000,000

'

'

'

'

'

'

'

408,000,000

'

'

'

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 temporary financial difficulties

'

'

'

'

'

'

'

'

'

'

'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]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Threshold charge-off period for past due accounts

'

'

'

'

'

'

'

'

'

'

'120 days

'

'

'

Provision for loan losses

'

'

'

'

'

'

'

'

'

'

28,000,000

'

'

'

Allowance for loan losses

'

'

$28,000,000

'

'

'

'

'

'

'

$28,000,000

'

'

'

Loan_Receivables_Schedule_of_L

Loan Receivables (Schedule of Loan Receivables) (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012		Nov. 30, 2012	Dec. 31, 2011	Nov. 30, 2011	Nov. 30, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Mortgage loans held for sale	$148,000,000	[1]	$355,000,000	[1]	'	'	'	'
Credit card loans	53,150,000,000		51,135,000,000		'	'	'	'
Other loans	8,295,000,000		6,406,000,000		'	'	'	'
Purchased credit-impaired loans	4,178,000,000		4,702,000,000		'	'	'	'
Total loan portfolio	65,623,000,000		62,243,000,000		'	'	'	'
Total loan receivables	65,771,000,000		62,598,000,000		'	59,372,000,000	'	'
Allowance for loan losses	-1,648,000,000		-1,788,000,000		-1,725,000,000	-2,245,000,000	-2,205,000,000	-3,304,000,000
Net loan receivables	64,123,000,000		60,810,000,000		'	'	'	'
Variable Interest Entity, Primary Beneficiary [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Allowance for loan losses	-861,000,000		-1,110,000,000		'	'	'	'
Credit Card Securitization Trusts [Member] | Variable Interest Entity, Primary Beneficiary [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Credit card loans	31,112,000,000	[2]	34,782,000,000	[2]	'	'	'	'
Allowance for loan losses	-833,000,000	[2]	-1,110,000,000	[2]	'	'	'	'
Sellers' interest	10,898,000,000		15,976,000,000		'	'	'	'
Credit Card Receivable [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Credit card loans	53,150,000,000		51,135,000,000		'	'	'	'
Total loan portfolio	53,150,000,000		51,135,000,000		'	'	'	'
Allowance for loan losses	-1,406,000,000		-1,613,000,000		-1,554,000,000	'	-2,070,000,000	-3,209,000,000
Total Other Loans [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Other loans	8,295,000,000		6,406,000,000		'	'	'	'
PCI Student Loans [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Purchased credit-impaired loans	4,178,000,000	[3]	4,702,000,000	[3]	'	'	'	'
Loans pledged as collateral	2,200,000,000		2,500,000,000		'	'	'	'
Private Student Loans Not Pledged as Collateral [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	2,000,000,000		2,200,000,000		'	'	'	'
Private Student Loans Eligible for Reimbursement [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	22,000,000		17,000,000		'	'	'	'
Discover Card [Member] | Credit Card Receivable [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Credit card loans	52,952,000,000	[4]	50,929,000,000	[4]	'	'	'	'
Discover Business Card [Member] | Credit Card Receivable [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Credit card loans	198,000,000		206,000,000		'	'	'	'
Personal Loans [Member] | Total Other Loans [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Other loans	4,191,000,000		3,296,000,000		'	'	'	'
Total loan portfolio	4,191,000,000		3,296,000,000		'	'	'	'
Allowance for loan losses	-112,000,000		-99,000,000		-97,000,000	'	-82,000,000	-76,000,000
Private Student Loans (Excluding PCI) [Member] | Total Other Loans [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Other loans	3,969,000,000		3,072,000,000		'	'	'	'
Other Loans [Member] | Total Other Loans [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Other loans	135,000,000		38,000,000		'	'	'	'
Total loan portfolio	135,000,000		38,000,000		'	'	'	'
Allowance for loan losses	-17,000,000		-1,000,000		-1,000,000	'	0	-1,000,000
Investors Interest in Trust Debt [Member] | Credit Card Receivable [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Credit card loans	$20,200,000,000		$18,800,000,000		'	'	'	'
[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 and $2.5 billion of loans pledged as collateral against the notes issued from the Student Loan Corporation ("SLC") securitization trusts at December 31, 2013 and 2012, respectively. See Note 6: Credit Card and Student Loan Securitization Activities. Of the remaining $2.0 billion and $2.2 billion at December 31, 2013 and 2012, respectively, that were not pledged as collateral, approximately $22 million and $17 million represent loans eligible for reimbursement through an indemnification claim, respectively. Discover Bank must purchase such loans from the trust before a claim may be filed.
[4]	Amounts include $20.2 billion and $18.8 billion underlying investors’ interest in trust debt at December 31, 2013 and 2012, respectively, and $10.9 billion and $16.0 billion in seller's interest at December 31, 2013 and 2012, respectively. The decrease in the seller's interest from December 31, 2012 to December 31, 2013 is due in part to the removal of randomly-selected accounts from the credit card loan receivables restricted for securitization investors in order to reduce excess seller's interest. See Note 6: 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 $)	1 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2013		Nov. 30, 2012	Nov. 30, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'		'	'
Loan receivables, 30 to 89 days delinquent	$503		$535		'	'
Loan receivables, 90 or more days delinquent	478		475		'	'
Loan receivables, total past due	981		1,010		'	'
Loan receivables, 90 or more days delinquent and accruing	423		434		'	'
Loan receivables, total non-accruing	192		200		'	'
Consumer Credit Card Financing Receivable [Member]	'		'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'		'	'
Loan receivables, 90 or more days delinquent and accruing	52		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	2		3		'	'
Credit Card Receivable [Member]	'		'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'		'	'
Loan receivables, 30 to 89 days delinquent	457		465		'	'
Loan receivables, 90 or more days delinquent	460		447		'	'
Loan receivables, total past due	917		912		'	'
Loan receivables, 90 or more days delinquent and accruing	409		408		'	'
Loan receivables, total non-accruing	184	[1]	155	[1]	'	'
Estimated gross interest income that would have been recorded based on original terms	3		29		32	45
Total Other Loans [Member]	'		'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'		'	'
Loan receivables, 30 to 89 days delinquent	46		70		'	'
Loan receivables, 90 or more days delinquent	18		28		'	'
Loan receivables, total past due	64		98		'	'
Loan receivables, 90 or more days delinquent and accruing	14		26		'	'
Loan receivables, total non-accruing	8		45		'	'
Discover Card [Member] | Credit Card Receivable [Member]	'		'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'		'	'
Loan receivables, 30 to 89 days delinquent	455		464		'	'
Loan receivables, 90 or more days delinquent	458		445		'	'
Loan receivables, total past due	913		909		'	'
Loan receivables, 90 or more days delinquent and accruing	407	[2]	406	[2]	'	'
Loan receivables, total non-accruing	183		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	2		2		'	'
Loan receivables, total past due	4		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	18		21		'	'
Loan receivables, 90 or more days delinquent	8		8		'	'
Loan receivables, total past due	26		29		'	'
Loan receivables, 90 or more days delinquent and accruing	7	[3]	8	[3]	'	'
Loan receivables, total non-accruing	4		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	28		48		'	'
Loan receivables, 90 or more days delinquent	9		18		'	'
Loan receivables, total past due	37		66		'	'
Loan receivables, 90 or more days delinquent and accruing	7	[4]	18	[4]	'	'
Loan receivables, total non-accruing	2		0		'	'
Other Loans [Member] | Total Other Loans [Member]	'		'		'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'		'		'	'
Loan receivables, 30 to 89 days delinquent	0		1		'	'
Loan receivables, 90 or more days delinquent	1		2		'	'
Loan receivables, total past due	1		3		'	'
Loan receivables, 90 or more days delinquent and accruing	0		0		'	'
Loan receivables, total non-accruing	$2		$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 $29 million, $32 million, $45 million and $3 million for the calendar year ended December 31, 2013, fiscal years ended November 30, 2012 and 2011 and one month ended December 31, 2012, respectively. The Company does not separately track 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' current balances and most recent interest rates.
[2]	Consumer credit card loans that are 90 or more days delinquent and accruing interest include $41 million and $52 million of loans accounted for as troubled debt restructurings at December 31, 2013 and 2012, 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 both December 31, 2013 and 2012, respectively.
[4]	Private student loans that are 90 or more days delinquent and accruing interest include $3 million and $2 million of loans accounted for as troubled debt restructurings at December 31, 2013 and 2012.

Loan_Receivables_Schedule_of_N

Loan Receivables (Schedule of Net Charge-offs) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Charge Offs [Line Items]	'	'	'	'
Net charge-offs	$115	$1,226	$1,328	$2,112
Credit Card Receivable [Member]	'	'	'	'
Charge Offs [Line Items]	'	'	'	'
Net charge-offs	106	1,100	1,240	2,036
Excluding PCI Loans [Member]	'	'	'	'
Charge Offs [Line Items]	'	'	'	'
Net charge-offs	115	1,226	1,328	2,112
Net charge-off rate	2.37%	2.14%	2.50%	4.21%
Excluding PCI Loans [Member] | Credit Card Receivable [Member]	'	'	'	'
Charge Offs [Line Items]	'	'	'	'
Net charge-offs	106	1,100	1,240	2,036
Net charge-off rate	2.47%	2.21%	2.62%	4.47%
Excluding PCI Loans [Member] | Total Other Loans [Member]	'	'	'	'
Charge Offs [Line Items]	'	'	'	'
Net charge-offs	9	126	88	76
Net charge-off rate	1.61%	1.67%	1.52%	1.65%
Including PCI Loans [Member]	'	'	'	'
Charge Offs [Line Items]	'	'	'	'
Net charge-offs	115	1,226	1,328	2,112
Net charge-off rate	2.19%	1.98%	2.29%	3.97%
Discover Card [Member] | Excluding PCI Loans [Member] | Credit Card Receivable [Member]	'	'	'	'
Charge Offs [Line Items]	'	'	'	'
Net charge-offs	106	1,096	1,233	2,018
Net charge-off rate	2.48%	2.21%	2.62%	4.46%
Discover Business Card [Member] | Excluding PCI Loans [Member] | Credit Card Receivable [Member]	'	'	'	'
Charge Offs [Line Items]	'	'	'	'
Net charge-offs	0	4	7	18
Net charge-off rate	2.08%	2.05%	3.36%	7.27%
Personal Loans [Member] | Total Other Loans [Member]	'	'	'	'
Charge Offs [Line Items]	'	'	'	'
Net charge-offs	7	79	69	67
Personal Loans [Member] | Excluding PCI Loans [Member] | Total Other Loans [Member]	'	'	'	'
Charge Offs [Line Items]	'	'	'	'
Net charge-offs	7	79	69	67
Net charge-off rate	2.52%	2.13%	2.33%	3.02%
Private Student Loans (Excluding PCI) [Member] | Excluding PCI Loans [Member] | Total Other Loans [Member]	'	'	'	'
Charge Offs [Line Items]	'	'	'	'
Net charge-offs	2	46	19	7
Net charge-off rate	0.81%	1.30%	0.73%	0.48%
Other Loans [Member] | Total Other Loans [Member]	'	'	'	'
Charge Offs [Line Items]	'	'	'	'
Net charge-offs	0	1	0	2
Other Loans [Member] | Excluding PCI Loans [Member] | Total Other Loans [Member]	'	'	'	'
Charge Offs [Line Items]	'	'	'	'
Net charge-offs	$0	$1	$0	$2
Net charge-off rate	0.00%	1.96%	0.10%	9.27%

Loan_Receivables_Schedule_of_C

Loan Receivables (Schedule of Credit Risk Profile by FICO Score) (Details)	Dec. 31, 2013		Dec. 31, 2012
Discover Card [Member] | Credit Card Receivable [Member]	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Credit risk profile by FICO score, 660 and above	83.00%		83.00%
Credit risk profile by FICO score, less than 660 or no score	17.00%		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%		91.00%
Credit risk profile by FICO score, less than 660 or no score	8.00%		9.00%
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 $)

1 Months Ended

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Nov. 30, 2012

Aug. 31, 2012

31-May-12

Feb. 29, 2012

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2011

Allowance For Loan And Lease Losses Writeoffs Net Abstract [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

Allowance for loan losses, balance at beginning of period

$1,725

$2,205

'

'

'

$1,788

'

'

'

$2,205

$1,788

$2,205

$3,304

Provision for loan losses

178

173

354

333

240

159

338

126

232

152

1,086

848

1,013

Charge-offs

-156

'

'

'

'

'

'

'

'

'

-1,739

-1,909

-2,693

Recoveries

41

'

'

'

'

'

'

'

'

'

513

581

581

Net charge-offs

-115

'

'

'

'

'

'

'

'

'

-1,226

-1,328

-2,112

Allowance for loan losses, balance at end of period

1,788

2,245

1,648

'

'

'

1,725

'

'

'

1,648

1,725

2,205

Credit Card Receivable [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Allowance For Loan And Lease Losses Writeoffs Net Abstract [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

Allowance for loan losses, balance at beginning of period

1,554

2,070

'

'

'

1,613

'

'

'

2,070

1,613

2,070

3,209

Provision for loan losses

165

'

'

'

'

'

'

'

'

'

893

724

897

Charge-offs

-146

'

'

'

'

'

'

'

'

'

-1,604

-1,817

-2,615

Recoveries

40

'

'

'

'

'

'

'

'

'

504

577

579

Net charge-offs

-106

'

'

'

'

'

'

'

'

'

-1,100

-1,240

-2,036

Allowance for loan losses, balance at end of period

1,613

'

1,406

'

'

'

1,554

'

'

'

1,406

1,554

2,070

Personal Loans [Member] | Total Other Loans [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Allowance For Loan And Lease Losses Writeoffs Net Abstract [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

Allowance for loan losses, balance at beginning of period

97

82

'

'

'

99

'

'

'

82

99

82

76

Provision for loan losses

9

'

'

'

'

'

'

'

'

'

92

84

73

Charge-offs

-8

'

'

'

'

'

'

'

'

'

-86

-73

-69

Recoveries

1

'

'

'

'

'

'

'

'

'

7

4

2

Net charge-offs

-7

'

'

'

'

'

'

'

'

'

-79

-69

-67

Allowance for loan losses, balance at end of period

99

'

112

'

'

'

97

'

'

'

112

97

82

Student Loans [Member] | Total Other Loans [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Allowance For Loan And Lease Losses Writeoffs Net Abstract [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

Allowance for loan losses, balance at beginning of period

73

53

'

'

'

75

'

'

'

53

75

53

18

Provision for loan losses

4

'

'

'

'

'

'

'

'

'

84

39

42

Charge-offs

-2

'

'

'

'

'

'

'

'

'

-48

-19

-7

Recoveries

0

'

'

'

'

'

'

'

'

'

2

0

0

Net charge-offs

-2

'

'

'

'

'

'

'

'

'

-46

-19

-7

Allowance for loan losses, balance at end of period

75

'

113

'

'

'

73

'

'

'

113

73

53

Other Loans [Member] | Total Other Loans [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Allowance For Loan And Lease Losses Writeoffs Net Abstract [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

Allowance for loan losses, balance at beginning of period

1

0

'

'

'

1

'

'

'

0

1

0

1

Provision for loan losses

0

'

'

'

'

'

'

'

'

'

17

1

1

Charge-offs

0

'

'

'

'

'

'

'

'

'

-1

0

-2

Recoveries

0

'

'

'

'

'

'

'

'

'

0

0

0

Net charge-offs

0

'

'

'

'

'

'

'

'

'

-1

0

-2

Allowance for loan losses, balance at end of period

$1

'

$17

'

'

'

$1

'

'

'

$17

$1

$0

Loan_Receivables_Schedule_of_N1

Loan Receivables (Schedule of Net Charge-offs of Interest and Fee Revenues on Loan Receivables) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Loans and Leases Receivable Disclosure [Abstract]	'	'	'	'
Interest and fees accrued subsequently charged off, net of recoveries (recorded as a reduction of interest income)	$26	$280	$345	$589
Fees accrued subsequently charged off, net of recoveries (recorded as a reduction to other income)	$5	$59	$67	$106

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 $)	Dec. 31, 2013		Dec. 31, 2012		Nov. 30, 2012	Dec. 31, 2011	Nov. 30, 2011	Nov. 30, 2010
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	$1,404		$1,600		'	'	'	'
Allowance for loan losses, evaluated for impairment in accordance with ASC 310-10-35	216	[1],[2]	188	[1],[2]	'	'	'	'
Allowance for loan losses, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	28		0		'	'	'	'
Allowance for loan losses	1,648		1,788		1,725	2,245	2,205	3,304
Recorded investment in loans, collectively evaluated for impairment in accordance with ASC 450-20	60,184		56,195		'	'	'	'
Recorded investment in loans, evaluated for impairment in accordance with ASC 310-10-35	1,261	[1],[2]	1,346	[1],[2]	'	'	'	'
Recorded investment in loans, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	4,178		4,702		'	'	'	'
Total loan portfolio	65,623		62,243		'	'	'	'
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	1,218		1,433		'	'	'	'
Allowance for loan losses, evaluated for impairment in accordance with ASC 310-10-35	188	[1],[2]	180	[1],[2]	'	'	'	'
Allowance for loan losses, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	0		0		'	'	'	'
Allowance for loan losses	1,406		1,613		1,554	'	2,070	3,209
Recorded investment in loans, collectively evaluated for impairment in accordance with ASC 450-20	52,027		49,826		'	'	'	'
Recorded investment in loans, evaluated for impairment in accordance with ASC 310-10-35	1,123	[1],[2]	1,309	[1],[2]	'	'	'	'
Recorded investment in loans, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	0		0		'	'	'	'
Total loan portfolio	53,150		51,135		'	'	'	'
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	900		1,100		'	'	'	'
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		0		'	'	'	'
Recorded investment in loans, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	4,178		4,702		'	'	'	'
Student Loans [Member]	'		'		'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'	'	'	'
Allowance for loan losses	113		75		'	'	'	'
Total loan portfolio	8,147		7,774		'	'	'	'
Personal Loans [Member] | Total 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	109		95		'	'	'	'
Allowance for loan losses, evaluated for impairment in accordance with ASC 310-10-35	3	[1],[2]	4	[1],[2]	'	'	'	'
Allowance for loan losses, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	0		0		'	'	'	'
Allowance for loan losses	112		99		97	'	82	76
Recorded investment in loans, collectively evaluated for impairment in accordance with ASC 450-20	4,160		3,275		'	'	'	'
Recorded investment in loans, evaluated for impairment in accordance with ASC 310-10-35	31	[1],[2]	21	[1],[2]	'	'	'	'
Recorded investment in loans, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	0		0		'	'	'	'
Total loan portfolio	4,191		3,296		'	'	'	'
Personal Loans [Member] | Total Other 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	31		21		'	'	'	'
Private Student Loans (Excluding PCI) [Member] | Total 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	76		71		'	'	'	'
Allowance for loan losses, evaluated for impairment in accordance with ASC 310-10-35	9	[1],[2]	4	[1],[2]	'	'	'	'
Recorded investment in loans, collectively evaluated for impairment in accordance with ASC 450-20	3,941		3,056		'	'	'	'
Recorded investment in loans, evaluated for impairment in accordance with ASC 310-10-35	28	[1],[2]	16	[1],[2]	'	'	'	'
Private Student Loans (Excluding PCI) [Member] | Total Other 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	26		15		'	'	'	'
Other Loans [Member] | Total 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	16	[1],[2]	0	[1],[2]	'	'	'	'
Allowance for loan losses, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	0		0		'	'	'	'
Allowance for loan losses	17		1		1	'	0	1
Recorded investment in loans, collectively evaluated for impairment in accordance with ASC 450-20	56		38		'	'	'	'
Recorded investment in loans, evaluated for impairment in accordance with ASC 310-10-35	79	[1],[2]	0	[1],[2]	'	'	'	'
Recorded investment in loans, acquired with deteriorated credit quality, evaluated in accordance with ASC 310-30	0		0		'	'	'	'
Total loan portfolio	$135		$38		'	'	'	'
[1]	The unpaid principal balance of credit card loans was $0.9 billion and $1.1 billion at December 31, 2013 and 2012 respectively. The unpaid principal balance of personal loans was $31 million and $21 million at December 31, 2013 and 2012, respectively. The unpaid principal balance of student loans was $26 million and $15 million at December 31, 2013 and 2012, respectively. All loans accounted for as troubled debt restructurings have a related allowance for loan losses.
[2]	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.

Loan_Receivables_Schedule_of_T

Loan Receivables (Schedule of Troubled Debt Restructurings) (Details) (USD $)	1 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2013		Nov. 30, 2012		Nov. 30, 2011
Credit Card Receivable [Member] | Modified Loans [Member]	'		'		'		'
Financing Receivable, Modifications [Line Items]	'		'		'		'
Average recorded investment in loans	$281	[1]	$269	[1]	$255	[1]	$276	[1]
Interest income recognized during period loans were impaired	4	[1],[2]	49	[1],[2]	48	[1],[2]	48	[1],[2]
Gross interest income that would have been recorded with original terms	0	[1],[3]	3	[1],[3]	'		'
Credit Card Receivable [Member] | Internal Programs [Member]	'		'		'		'
Financing Receivable, Modifications [Line Items]	'		'		'		'
Average recorded investment in loans	509		468		557		537
Interest income recognized during period loans were impaired	1	[2]	9	[2]	17	[2]	21	[2]
Gross interest income that would have been recorded with original terms	6	[3]	66	[3]	73	[3]	65	[3]
Credit Card Receivable [Member] | External Programs [Member]	'		'		'		'
Financing Receivable, Modifications [Line Items]	'		'		'		'
Average recorded investment in loans	530		463		603		715
Interest income recognized during period loans were impaired	4	[2]	36	[2]	51	[2]	62	[2]
Gross interest income that would have been recorded with original terms	1	[3]	11	[3]	9	[3]	10	[3]
Personal Loans [Member] | Total Other Loans [Member]	'		'		'		'
Financing Receivable, Modifications [Line Items]	'		'		'		'
Average recorded investment in loans	21		26		16		7
Interest income recognized during period loans were impaired	0	[2]	3	[2]	2	[2]	1	[2]
Gross interest income that would have been recorded with original terms	'		1	[3]	'		'
Student Loans [Member] | Total Other Loans [Member]	'		'		'		'
Financing Receivable, Modifications [Line Items]	'		'		'		'
Average recorded investment in loans	16	[4]	22	[4]	10	[4]	5	[4]
Interest income recognized during period loans were impaired	$0	[2],[4]	$2	[2],[4]	$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 that have subsequently reverted back to the loans' pre-modification payment terms either due to noncompliance with the terms of the modification or successful completion of a temporary modification 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 $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
	accounts	accounts	accounts	accounts
Credit Card Receivable [Member] | Internal Programs [Member]	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Accounts that entered a loan modification program during the period, number of accounts	3,078	40,653	50,946	68,738
Accounts that entered a loan modification program during the period, balances	$19	$256	$345	$480
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	2,614	35,020	40,530	52,705
Accounts that entered a loan modification program during the period, balances	14	189	227	310
Personal Loans [Member] | Total Other Loans [Member]	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Accounts that entered a loan modification program during the period, number of accounts	120	2,178	1,555	410
Accounts that entered a loan modification program during the period, balances	2	27	20	5
Student Loans [Member] | Total Other Loans [Member]	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Accounts that entered a loan modification program during the period, number of accounts	60	877	470	262
Accounts that entered a loan modification program during the period, balances	$2	$17	$11	$5

Loan_Receivables_Loan_Receivab1

Loan Receivables Loan Receivables (Schedule of Troubled Debt Restructurings That Subsequently Defaulted) (Details) (USD $)	1 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2013		Nov. 30, 2012		Nov. 30, 2011
	accounts		accounts		accounts		accounts
Credit Card Receivable [Member] | Internal Programs [Member]	'		'		'		'
Financing Receivable, Modifications [Line Items]	'		'		'		'
Troubled debt restructurings that subsequently defaulted, number of accounts	945	[1],[2]	9,186	[1],[2]	15,703	[1],[2]	18,354	[1],[2]
Troubled debt restructurings that subsequently defaulted, aggregated outstanding balances upon default	$6	[1],[2]	$57	[1],[2]	$106	[1],[2]	$131	[1],[2]
Credit Card Receivable [Member] | External Programs [Member]	'		'		'		'
Financing Receivable, Modifications [Line Items]	'		'		'		'
Troubled debt restructurings that subsequently defaulted, number of accounts	722	[1],[2]	8,481	[1],[2]	8,543	[1],[2]	11,974	[1],[2]
Troubled debt restructurings that subsequently defaulted, aggregated outstanding balances upon default	3	[1],[2]	36	[1],[2]	40	[1],[2]	62	[1],[2]
Personal Loans [Member] | Total Other Loans [Member]	'		'		'		'
Financing Receivable, Modifications [Line Items]	'		'		'		'
Troubled debt restructurings that subsequently defaulted, number of accounts	22	[1]	284	[1]	343	[1]	17	[1]
Troubled debt restructurings that subsequently defaulted, aggregated outstanding balances upon default	0	[1]	3	[1]	4	[1]	0	[1]
Student Loans [Member]	'		'		'		'
Financing Receivable, Modifications [Line Items]	'		'		'		'
Delinquency days to default	'		'60 days		'		'
Student Loans [Member] | Total Other Loans [Member]	'		'		'		'
Financing Receivable, Modifications [Line Items]	'		'		'		'
Troubled debt restructurings that subsequently defaulted, number of accounts	42	[3]	628	[3]	172	[3]	19	[3]
Troubled debt restructurings that subsequently defaulted, aggregated outstanding balances upon default	$1	[3]	$12	[3]	$4	[3]	$1	[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 $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]	'	'	'	'
Accretable yield, balance at beginning of period	$2,096	$2,072	$2,580	$0
Accretion into interest income	-24	-272	-303	-225
Other changes in expected cash flows	0	-220	-181	30
Accretable yield, balance at end of period	2,072	1,580	2,096	2,580
Initial Acquisition of Loans [Member]	'	'	'	'
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]	'	'	'	'
Accretable yield, additions	0	0	0	1,920
Subsequent Acquisition of Loans [Member]	'	'	'	'
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]	'	'	'	'
Accretable yield, additions	$0	$0	$0	$855

Loan_Receivables_Loan_Receivab2

Loan Receivables Loan Receivables (Schedule of Initial Unpaid Principal Balance of Mortgage Loans Sold by Type) (Details) (USD $)	1 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2013		Nov. 30, 2012
Mortgage Loans on Real Estate [Line Items]	'		'		'
Initial unpaid principal balance of mortgage loans, amount	$363		$4,015		$1,726
Initial unpaid principal balance of mortgage loans, percentage	100.00%		100.00%		100.00%
Conforming Loans [Member]	'		'		'
Mortgage Loans on Real Estate [Line Items]	'		'		'
Initial unpaid principal balance of mortgage loans, amount	218	[1]	2,721	[1]	1,213	[1]
Initial unpaid principal balance of mortgage loans, percentage	60.06%	[1]	67.77%	[1]	70.28%	[1]
FHA Loans [Member]	'		'		'
Mortgage Loans on Real Estate [Line Items]	'		'		'
Initial unpaid principal balance of mortgage loans, amount	145	[2]	1,290	[2]	513	[2]
Initial unpaid principal balance of mortgage loans, percentage	39.94%	[2]	32.13%	[2]	29.72%	[2]
Jumbo Mortgage Loans [Member]	'		'		'
Mortgage Loans on Real Estate [Line Items]	'		'		'
Initial unpaid principal balance of mortgage loans, amount	$0	[3]	$4	[3]	$0	[3]
Initial unpaid principal balance of mortgage loans, percentage	0.00%	[3]	0.10%	[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 $)	1 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2013
Mortgage Loans on Real Estate [Line Items]	'		'
Mortgage loans held for sale, amount	$355	[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	177	[2]	136	[2]
Mortgage loans held for sale, percentage	49.86%	[2]	91.89%	[2]
FHA Loans [Member]	'		'
Mortgage Loans on Real Estate [Line Items]	'		'
Mortgage loans held for sale, amount	178	[3]	11	[3]
Mortgage loans held for sale, percentage	50.14%	[3]	7.43%	[3]
Jumbo Mortgage Loans [Member]	'		'
Mortgage Loans on Real Estate [Line Items]	'		'
Mortgage loans held for sale, amount	$0	[4]	$1	[4]
Mortgage loans held for sale, percentage	0.00%	[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 amount larger than the limits set by a Government Sponsored Enterprise.

Loan_Receivables_Loan_Recievab

Loan Receivables Loan Recievables (Schedule of Geographic Distribution of Loan Receivables) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	$65,623	$62,243
Credit Card Receivable [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	53,150	51,135
Percentage of total loan receivables	100.00%	100.00%
Credit Card Receivable [Member] | California [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	4,548	4,442
Percentage of total loan receivables	8.50%	8.70%
Credit Card Receivable [Member] | Texas [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	4,299	4,090
Percentage of total loan receivables	8.10%	8.00%
Credit Card Receivable [Member] | New York [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	3,649	3,457
Percentage of total loan receivables	6.90%	6.80%
Credit Card Receivable [Member] | Florida [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	3,064	2,949
Percentage of total loan receivables	5.80%	5.80%
Credit Card Receivable [Member] | Illinois [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	2,998	2,903
Percentage of total loan receivables	5.60%	5.70%
Credit Card Receivable [Member] | Pennsylvania [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	2,823	2,703
Percentage of total loan receivables	5.30%	5.30%
Credit Card Receivable [Member] | Ohio [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	2,324	2,233
Percentage of total loan receivables	4.40%	4.40%
Credit Card Receivable [Member] | New Jersey [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	2,002	1,940
Percentage of total loan receivables	3.80%	3.80%
Credit Card Receivable [Member] | Michigan [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	1,575	1,537
Percentage of total loan receivables	3.00%	3.00%
Credit Card Receivable [Member] | Georgia [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	1,546	1,499
Percentage of total loan receivables	2.90%	2.90%
Credit Card Receivable [Member] | Other States [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	24,322	23,382
Percentage of total loan receivables	45.70%	45.60%
Total Other Loans and PCI Loans [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	12,473	11,108
Percentage of total loan receivables	100.00%	100.00%
Total Other Loans and PCI Loans [Member] | California [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	1,167	1,039
Percentage of total loan receivables	9.40%	9.40%
Total Other Loans and PCI Loans [Member] | Texas [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	637	542
Percentage of total loan receivables	5.10%	4.90%
Total Other Loans and PCI Loans [Member] | New York [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	1,679	1,614
Percentage of total loan receivables	13.40%	14.50%
Total Other Loans and PCI Loans [Member] | Florida [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	479	419
Percentage of total loan receivables	3.80%	3.80%
Total Other Loans and PCI Loans [Member] | Illinois [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	696	612
Percentage of total loan receivables	5.60%	5.50%
Total Other Loans and PCI Loans [Member] | Pennsylvania [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	939	877
Percentage of total loan receivables	7.50%	7.90%
Total Other Loans and PCI Loans [Member] | Ohio [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	481	418
Percentage of total loan receivables	3.90%	3.80%
Total Other Loans and PCI Loans [Member] | New Jersey [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	630	570
Percentage of total loan receivables	5.10%	5.10%
Total Other Loans and PCI Loans [Member] | Michigan [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	482	436
Percentage of total loan receivables	3.90%	3.90%
Total Other Loans and PCI Loans [Member] | Massachusetts [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	508	463
Percentage of total loan receivables	4.10%	4.20%
Total Other Loans and PCI Loans [Member] | Other States [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loan portfolio	$4,775	$4,118
Percentage of total loan receivables	38.20%	37.00%

Credit_Card_and_Student_Loan_S2

Credit Card and Student Loan Securitization Activities (Narrative) (Details) (USD $)	12 Months Ended
In Billions, unless otherwise specified	Dec. 31, 2013
Variable Interest Entity [Line Items]	'
Excess spread rate minimum	0.00%
Excess of the total investors' interests	7.00%
Amount removed from credit card receivables restricted for securitization investors	$3
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 $)	Dec. 31, 2013		Dec. 31, 2012		Nov. 30, 2012	Dec. 31, 2011	Nov. 30, 2011	Nov. 30, 2010
In Millions, unless otherwise specified
Variable Interest Entity [Line Items]	'		'		'	'	'	'
Restricted cash	$182		$290		'	'	'	'
Loan receivables	53,150		51,135		'	'	'	'
Allowance for loan losses allocated to securitized loan receivables	-1,648		-1,788		-1,725	-2,245	-2,205	-3,304
Other	2,367		2,562		'	'	'	'
Variable Interest Entity, Primary Beneficiary [Member]	'		'		'	'	'	'
Variable Interest Entity [Line Items]	'		'		'	'	'	'
Restricted cash	179		280		'	'	'	'
Allowance for loan losses allocated to securitized loan receivables	-861		-1,110		'	'	'	'
Other	34		29		'	'	'	'
Variable Interest Entity, Primary Beneficiary [Member] | Credit Card Securitization Trusts [Member]	'		'		'	'	'	'
Variable Interest Entity [Line Items]	'		'		'	'	'	'
Restricted cash	90		184		'	'	'	'
Investors' interests held by third-party investors	15,190		13,768		'	'	'	'
Investors' interests held by wholly owned subsidiaries of Discover Bank	5,024		5,038		'	'	'	'
Seller's interest	10,898		15,976		'	'	'	'
Loan receivables	31,112	[1]	34,782	[1]	'	'	'	'
Allowance for loan losses allocated to securitized loan receivables	-833	[1]	-1,110	[1]	'	'	'	'
Net loan receivables	30,279		33,672		'	'	'	'
Other	34		29		'	'	'	'
Carrying value of assets of consolidated variable interest entities	30,403		33,885		'	'	'	'
Variable Interest Entity, Primary Beneficiary [Member] | Credit Card Securitization Trusts [Member] | Cash Collateral Accounts [Member]	'		'		'	'	'	'
Variable Interest Entity [Line Items]	'		'		'	'	'	'
Restricted cash	59		93		'	'	'	'
Variable Interest Entity, Primary Beneficiary [Member] | Credit Card Securitization Trusts [Member] | Collections and Interest Funding Accounts [Member]	'		'		'	'	'	'
Variable Interest Entity [Line Items]	'		'		'	'	'	'
Restricted cash	$31		$91		'	'	'	'
[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 $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Variable Interest Entity [Line Items]	'
Investors' interests	20,214	[1]
Number of series outstanding	39
Group Excess Spread Percentage [Member]	'
Variable Interest Entity [Line Items]	'
Three month rolling average excess spread	14.17%	[2]
Discover Series Excess Spread Percentage [Member]	'
Variable Interest Entity [Line Items]	'
Three month rolling average excess spread	14.15%	[2]
Discover Card Master Trust I [Member]	'
Variable Interest Entity [Line Items]	'
Investors' interests	918	[1]
Number of series outstanding	2
Discover Card Execution Note Trust (DiscoverSeries Notes) [Member]	'
Variable Interest Entity [Line Items]	'
Investors' interests	19,296	[1]
Number of series outstanding	37
[1]	Investors’ interests include third-party interests and subordinated interests held by wholly-owned subsidiaries of Discover Bank.
[2]	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.

Credit_Card_and_Student_Loan_S5

Credit Card and Student Loan Securitization Activities (Schedule of Restricted Student Loan Securitized Assets) (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012		Nov. 30, 2012	Dec. 31, 2011	Nov. 30, 2011	Nov. 30, 2010
In Millions, unless otherwise specified
Variable Interest Entity [Line Items]	'		'		'	'	'	'
Restricted cash	$182		$290		'	'	'	'
Student loan receivables	4,178		4,702		'	'	'	'
Allowance for loan losses allocated to securitized loan receivables	-1,648		-1,788		-1,725	-2,245	-2,205	-3,304
Variable Interest Entity, Primary Beneficiary [Member]	'		'		'	'	'	'
Variable Interest Entity [Line Items]	'		'		'	'	'	'
Restricted cash	179		280		'	'	'	'
Allowance for loan losses allocated to securitized loan receivables	-861		-1,110		'	'	'	'
Variable Interest Entity, Primary Beneficiary [Member] | Student Loan Securitization Trusts [Member]	'		'		'	'	'	'
Variable Interest Entity [Line Items]	'		'		'	'	'	'
Restricted cash	89		96		'	'	'	'
Student loan receivables	2,248		2,539		'	'	'	'
Allowance for loan losses allocated to securitized loan receivables	-28	[1]	0	[1]	'	'	'	'
Net student loan receivables	2,220		2,539		'	'	'	'
Carrying value of assets of consolidated variable interest entities	$2,309		$2,635		'	'	'	'
[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.

Premises_and_Equipment_Premise1

Premises and Equipment Premises and Equipment (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Property, Plant and Equipment [Abstract]	'	'	'	'
Depreciation expense, including amortization of assets under capital leases	$6	$65	$63	$60
Amortization expense on capitalized software	$3	$41	$32	$30

Premises_and_Equipment_Premise2

Premises and Equipment Premises and Equipment (Schedule of Premises and Equipment) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Premises and equipment, gross	$1,718	$1,615
Premises and equipment, net	654	538
Land [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Premises and equipment, gross	43	42
Building and Improvements [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Premises and equipment, gross	547	517
Capitalized Equipment Leases [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Premises and equipment, gross	2	2
Furniture, Fixtures and Equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Premises and equipment, gross	735	640
Software [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Premises and equipment, gross	391	414
Less: Accumulated depreciation and accumulated amortization of software	-235	-313
Property Plant And Equipment Excluding Software [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Less: Accumulated depreciation and accumulated amortization of software	($829)	($764)

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets (Narrative) (Details) (USD $)	0 Months Ended			1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Oct. 02, 2013	Jun. 02, 2013	Jun. 02, 2012	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Goodwill [Line Items]	'	'	'	'	'	'	'
Goodwill	'	'	'	$286	$284	'	'
Goodwill impairment loss	0	0	0	'	'	'	'
Intangible assets impairment loss	0	0	0	'	'	'	'
Amortization expense related to intangible assets	'	'	'	1	12	11	8
HLC Acquisition [Member] | Direct Banking [Member]	'	'	'	'	'	'	'
Goodwill [Line Items]	'	'	'	'	'	'	'
Goodwill	'	'	'	31	'	'	'
Goodwill purchase accounting adjustments	'	'	'	'	2	'	'
PULSE [Member] | Payment Services [Member]	'	'	'	'	'	'	'
Goodwill [Line Items]	'	'	'	'	'	'	'
Goodwill	'	'	'	'	$255	'	'

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets (Schedule of Intangible Assets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Finite Lived And Indefinite Lived Intangible Assets [Line Items]	'	'
Amortizable intangible assets, gross carrying amount	$100	$92
Amortizable intangible assets, accumulated amortization	70	58
Amortizable intangible assets, net book value	30	34
Non-amortizable intangible assets, gross carrying amount	155	155
Non-amortizable intangible assets, net book value	155	155
Total intangible assets, gross carrying amount	255	247
Total intangible assets, net book value	185	189
Trade Names [Member]	'	'
Finite Lived And Indefinite Lived Intangible Assets [Line Items]	'	'
Non-amortizable intangible assets, gross carrying amount	132	132
Non-amortizable intangible assets, net book value	132	132
International Transaction Processing Rights [Member]	'	'
Finite Lived And Indefinite Lived Intangible Assets [Line Items]	'	'
Non-amortizable intangible assets, gross carrying amount	23	23
Non-amortizable intangible assets, net book value	23	23
Customer Relationships [Member]	'	'
Finite Lived And Indefinite Lived Intangible Assets [Line Items]	'	'
Amortizable intangible assets, weighted-average amortization period (in years)	'13 years 8 months 13 days	'
Amortizable intangible assets, gross carrying amount	78	72
Amortizable intangible assets, accumulated amortization	60	52
Amortizable intangible assets, net book value	18	20
Trade Names [Member]	'	'
Finite Lived And Indefinite Lived Intangible Assets [Line Items]	'	'
Amortizable intangible assets, weighted-average amortization period (in years)	'25 years	'
Amortizable intangible assets, gross carrying amount	8	8
Amortizable intangible assets, accumulated amortization	2	2
Amortizable intangible assets, net book value	6	6
Proprietary Software [Member]	'	'
Finite Lived And Indefinite Lived Intangible Assets [Line Items]	'	'
Amortizable intangible assets, weighted-average amortization period (in years)	'7 years	'
Amortizable intangible assets, gross carrying amount	6	6
Amortizable intangible assets, accumulated amortization	2	1
Amortizable intangible assets, net book value	4	5
Noncompete Agreements [Member]	'	'
Finite Lived And Indefinite Lived Intangible Assets [Line Items]	'	'
Amortizable intangible assets, weighted-average amortization period (in years)	'3 years	'
Amortizable intangible assets, gross carrying amount	2	2
Amortizable intangible assets, accumulated amortization	1	0
Amortizable intangible assets, net book value	1	2
Service Agreements [Member]	'	'
Finite Lived And Indefinite Lived Intangible Assets [Line Items]	'	'
Amortizable intangible assets, weighted-average amortization period (in years)	'13 months	'
Amortizable intangible assets, gross carrying amount	6	4
Amortizable intangible assets, accumulated amortization	5	3
Amortizable intangible assets, net book value	$1	$1

Goodwill_and_Intangible_Assets4

Goodwill and Intangible Assets (Schedule of Expected Intangilbe Asset Amortization Expense) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]	'
2014	$9
2015	5
2016	4
2017	3
2018	$3

Deposits_Narrative_Details

Deposits (Narrative) (Details) (USD $)	12 Months Ended
In Billions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
	channels
Deposits [Abstract]	'	'
Deposits source channels	2	'
Direct-to-consumer deposits	$28.40	$28
Brokered deposits	$16.40	$14.10

Deposits_Schedule_of_Interest_

Deposits (Schedule of Interest Bearing Deposit Accounts) (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2013	Dec. 31, 2013
					Prior FDIC Insured Deposit Limit [Member]	Current FDIC Insured Deposit Limit [Member]
Deposits [Line Items]	'		'		'	'
Certificates of deposit in amounts less than $100,000	$21,211,000,000	[1]	$21,070,000,000	[1]	'	'
Certificates of deposit from amounts of $100,000 to less than $250,000	4,860,000,000	[1]	5,508,000,000	[1]	'	'
Certificates of deposit in amounts of $250,000 or greater	1,180,000,000	[1]	1,280,000,000	[1]	'	'
Savings deposits, including money market deposit accounts	17,515,000,000		14,219,000,000		'	'
Total interest-bearing deposits	44,766,000,000		42,077,000,000		'	'
Average annual interest rate	1.57%		1.74%		'	'
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 $)	Dec. 31, 2013
In Millions, unless otherwise specified
Deposits [Abstract]	'
2014	$12,226
2015	6,301
2016	3,475
2017	2,198
2018	1,691
Thereafter	$1,360

LongTerm_Borrowings_Narrative_

Long-Term Borrowings (Narrative) (Details) (USD $)

1 Months Ended

12 Months Ended

3 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

3 Months Ended

12 Months Ended

1 Months Ended

3 Months Ended

12 Months Ended

Dec. 31, 2012

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2011

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Nov. 30, 2012

31-May-12

Dec. 31, 2012

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2011

Dec. 31, 2012

Nov. 30, 2012

Dec. 31, 2013

Dec. 31, 2012

31-May-12

Dec. 31, 2013

Nov. 30, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Secured Debt [Member]

Secured Debt [Member]

Fixed Rate Senior Notes Due November 2022 [Member]

Fixed Rate Senior Notes Due April 2022 [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]

Parent Company [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]

Fixed Rate Senior Notes Due November 2022 [Member]

Fixed Rate Senior Notes Due November 2022 [Member]

Fixed Rate Senior Notes Due November 2022 [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 April 2022 [Member]

Secured Debt [Member]

Secured Debt [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]

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]

Secured Debt [Member]

Secured Debt [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Outstanding aggregate principal amount exchanged

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$500,000,000

'

'

$322,000,000

'

'

'

'

'

'

Premium paid on debt exchange

0

0

291,000,000

0

'

'

'

176,000,000

115,000,000

0

0

115,000,000

0

'

'

'

'

'

'

'

'

'

'

'

Amortization of premium paid on debt exchange

'

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000

'

11,000,000

1,000,000

'

7,000,000

4,000,000

'

'

'

'

Total commitment of secured credit facilities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7,500,000,000

'

Long-term borrowings

$17,666,000,000

$20,474,000,000

'

'

$18,265,000,000

$16,986,000,000

$15,933,000,000

'

'

$1,035,000,000

[1]

$1,045,000,000

'

'

$324,000,000

'

$335,000,000

$211,000,000

'

$219,000,000

'

$15,194,000,000

$13,773,000,000

$500,000,000

$750,000,000

[1]

During the 2012 fiscal year, the Company completed a private exchange offer, resulting in the exchange of $500 million outstanding aggregate principal amount of subordinated debt issued by a subsidiary for the same aggregate principal amount of new senior notes issued by the Parent. A cash premium of $176 million paid by the subsidiary to bondholders tendering its subordinated notes under the exchange offer is reported as a component of the new senior notes and is thus included in other long term borrowings of the Parent.

LongTerm_Borrowings_Schedule_o

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

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

In Millions, unless otherwise specified

Parent Company [Member]

Parent Company [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]

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]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Subordinated Debt [Member]

Subordinated Debt [Member]

Subordinated Debt [Member]

Subordinated Debt [Member]

Capital Lease Obligations [Member]

Capital Lease Obligations [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]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Discover Bank [Member]

Fixed Rate Asset-Backed Securities [Member]

Fixed Rate Asset-Backed Securities [Member]

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

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

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

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

Floating Rate Asset-Backed Securities 1-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 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 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]

Subordinated Bank Notes Due 2019 [Member]

Subordinated Bank Notes Due 2019 [Member]

Subordinated Bank Notes Due 2020 [Member]

Subordinated Bank Notes Due 2020 [Member]

Minimum [Member]

Maximum [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

'

'

'

'

'

'

'

'

'

$129

$173

'

'

$3

$3

'

'

'

'

'

'

'

'

'

'

'

$103

$110

$165

$176

'

'

$6

$0

'

'

$2

$3

'

'

Premium

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

2

'

3

5

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal value

'

'

'

'

'

'

'

'

'

5,549

4,549

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

400

400

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair value adjustment

'

'

'

'

'

'

'

'

'

5

[1]

6

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

13

[1]

21

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term borrowings

$20,474

$17,666

$18,265

$1,045

$1,035

[2]

$16,986

$15,933

$15,194

$13,773

$5,554

$4,555

$9,140

$8,468

'

'

'

$500

$750

$1,792

$2,160

$1,005

$1,199

'

'

$434

$528

'

$105

$126

'

$248

$307

'

$413

$421

$78

$78

$219

$211

$335

$324

$750

$0

$994

$0

$200

$200

$498

$497

$1

$2

Interest rate

'

'

'

'

'

'

'

'

'

1.86%

2.87%

0.46%

0.50%

'

'

'

0.44%

0.64%

'

'

0.48%

0.56%

'

'

4.25%

4.25%

'

4.00%

4.00%

'

3.66%

3.71%

'

6.45%

6.45%

10.25%

10.25%

5.20%

5.20%

3.85%

3.85%

2.00%

0.00%

4.20%

0.00%

8.70%

8.70%

7.00%

7.00%

4.51%

4.51%

Interest rate terms

'

'

'

'

'

'

'

'

'

'Various fixed rates

'

'1-month LIBOR (2) + 8 to 58 basis points

[3]

'

'

'

'

'Commercial Paper rate + 30 basis points

'

'

'

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

[3]

'

'

'

'Prime rate + 100 basis points

'

'

'Prime rate + 75 basis points

'

'

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

[3]

'

'

'Fixed

'

'Fixed

'

'Fixed

'

'Fixed

'

'Fixed

'

'Fixed

'

'Fixed

'

'Fixed

'

'Fixed

'

Basis spread on variable rate

'

'

'

'

'

'

'

'

'

'

'

'

'

0.08%

0.58%

0.30%

'

'

'

'

'

'

0.12%

0.45%

'

'

1.00%

'

'

0.75%

'

'

3.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maturity

'

'

'

'

'

'

'

'

'

'Various February 2015 - July 2019

'

'Various February 2014 - October 2018

'

'

'

'

'March 2014

'

'

'

'Various January 2019 - July 2036 (3)

[4]

'

'

'

'June 2031 (3)

[4]

'

'

'July 2042 (3)

[4]

'

'

'July 2042 (3)

[4]

'

'

'June 2017

'

'July 2019

'

'April 2022

'

'November 2022

'

'February 2018

'

'August 2023

'

'November 2019

'

'April 2020

'

'April 2016

'

Maturity range, start

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'

'

'

'

'

'

'

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28-Feb-15

'

28-Feb-14

'

'

'

'

'

'

'

'

31-Jan-19

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maturity range, end

'

'

'

'

'

'

'

'

'

31-Jul-19

'

31-Oct-18

'

'

'

'

'

'

'

'

31-Jul-36

'

'

'

'

'

'

'

'

'

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'

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'

[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 22: Derivatives and Hedging Activities.

[2]

During the 2012 fiscal year, the Company completed a private exchange offer, resulting in the exchange of $500 million outstanding aggregate principal amount of subordinated debt issued by a subsidiary for the same aggregate principal amount of new senior notes issued by the Parent. A cash premium of $176 million paid by the subsidiary to bondholders tendering its subordinated notes under the exchange offer is reported as a component of the new senior notes and is thus included in other long term borrowings of the Parent.

[3]

London Interbank Offered Rate (“LIBOR”).

[4]

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 $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Debt Disclosure [Abstract]	'	'	'
Due in 2014	$4,290	'	'
Due in 2015	3,305	'	'
Due in 2016	3,050	'	'
Due in 2017	2,062	'	'
Due in 2018	2,650	'	'
Thereafter	5,117	'	'
Long-term borrowings	$20,474	$17,666	$18,265

StockBased_Compensation_Plans_1

Stock-Based Compensation Plans (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013
Restricted Stock Units [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total unrecognized compensation cost	$19,000,000	$28,000,000
Total period of unrecognized compensation cost recognition (in years)	'3 years 0 months 0 days	'2 years 1 month 7 days
Weighted average period of recognizing unrecognized compensation cost (in years)	'1 year 9 months 20 days	'2 years 9 months 19 days
Performance Stock Units [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total unrecognized compensation cost	24,000,000	34,000,000
Weighted average period of recognizing unrecognized compensation cost (in years)	'1 year 2 months 12 days	'0 years 9 months 19 days
Number of common shares to be paid upon conversion for awards granted in fiscal year 2011 and 2012 (in shares)	'	2
Number of common shares to be paid upon conversion for awards granted in fiscal year 2013 (in shares)	'	1.5
Award performance period for awards granted in fiscal year 2011 and 2012	'	'2 years
Award vesting period	'	'3 years
Award performance period for awards granted in fiscal year 2013	'	'3 years
Performance Stock Units [Member] | Non-Retirement Eligible Employees [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total period of unrecognized compensation cost recognition (in years)	'2 years 0 months 0 days	'2 years 1 month 7 days
Performance Stock Units [Member] | Retirement Eligible Employees [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total period of unrecognized compensation cost recognition (in years)	'0 years 10 months 24 days	'2 years 1 month 7 days
Stock Option [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Cash received from the exercise of stock options	6,000,000	7,000,000
Income tax benefit realized from the exercise of stock options	2,000,000	3,000,000
Omnibus Incentive Plan [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total number of shares available for grant (in shares)	'	45,000,000
Total unrecognized compensation cost	0	0
Omnibus Incentive Plan [Member] | Stock Option [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Expiration period of option awards (in years)	'	'10 years
Directors Compensation Plan [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Shares used in calculation of the total number of units available for grant (in shares)	'	1,000,000
Annual awards calculation	'	$125,000
Percentage of annual awards that shall vest on first anniversary date of grant	'	100.00%

StockBased_Compensation_Plans_2

Stock-Based Compensation Plans (Schedule of Stock-Based Compensation Plans Compensation cost, Net of Forfeitures) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Compensation cost, net of forfeitures	$3	$59	$47	$44
Income tax benefit from compensation cost, net of forfeitures	1	22	18	17
Restricted Stock Units [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Compensation cost, net of forfeitures	2	31	29	34
Performance Stock Units [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Compensation cost, net of forfeitures	$1	$28	$18	$10

StockBased_Compensation_Plans_3

Stock-Based Compensation Plans (Schedule of Restricted Stock Unit Activity) (Details) (Restricted Stock Units [Member], USD $)	1 Months Ended		12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2013		Nov. 30, 2012		Nov. 30, 2011
Restricted Stock Units [Member]	'		'		'		'
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options [Roll Forward]	'		'		'		'
Stock-based compensation, balance at beginning of period, number of units	4,771,746		4,774,171		'		'
Stock-based compensation, granted, number of units	2,425		998,263		'		'
Stock-based compensation, conversions to common stock, number of units	0		-1,565,574		'		'
Stock-based compensation, forfeited, number of units	0		-62,945		'		'
Stock-based compensation, balance at end of period, number of units	4,774,171		4,143,915		4,771,746		'
Stock-based compensation, balance at beginning of period, weighted-average grant-date fair value	$21.01		$21.02		'		'
Stock-based compensation, granted, weighted-average grant-date fair value	$41.23		$42.14		$25.64		$19.57
Stock-based compensation, conversions to common stock, weighted-average grant-date fair value	$0		$17.33		'		'
Stock-based compensation, forfeited, weighted-average grant-date fair value	$0		$26.83		'		'
Stock-based compensation, balance at end of period, weighted-average grant-date fair value	$21.02		$27.38		$21.01		'
Stock-based compensation, aggregate intrinsic value (in dollars)	$181		$232		'		'
Unvested stock-based compensation, balance at beginning of period, number of units	2,964,707	[1]	2,967,132	[1]	'		'
Stock-based compensation, vested, number of units	0		-1,404,830		'		'
Unvested stock-based compensation, balance at end of period, number of units	2,967,132	[1]	2,497,620	[1]	2,964,707	[1]	'
Unvested stock-based compensation, balance at beginning of period, weighted-average grant-date fair value (in dollars per share)	$19.62	[1]	$19.64	[1]	'		'
Stock-based compensation, vested, weighted-average grant-date fair value	$0		$19.41		'		'
Unvested stock-based compensation, balance at end of period, weighted-average grant-date fair value (in dollars per share)	$19.64	[1]	$28.52	[1]	$19.62	[1]	'
[1]	Unvested restricted stock units represent awards where recipients have yet to satisfy either explicit vesting terms or retirement-eligibility requirements.

StockBased_Compensation_Plans_4

Stock-Based Compensation Plans (Schedule of Intrinsic Value of RSUs Converted to Common Stock and Grant Date Fair Value of RSUs Vested) (Details) (Restricted Stock Units [Member], USD $)	1 Months Ended	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Restricted Stock Units [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Intrinsic value of RSUs converted to common stock	$0	$63	$49	$30
Grant date fair value of RSUs vested	$0	$27	$28	$35
Weighted average grant date fair value of RSUs granted (in dollars per share)	$41.23	$42.14	$25.64	$19.57

StockBased_Compensation_Plans_5

Stock-Based Compensation Plans (Schedule of Performance Stock Unit Activity) (Details) (Performance Stock Units [Member], USD $)	1 Months Ended		12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2013		Nov. 30, 2012		Nov. 30, 2011
Performance Stock Units [Member]	'		'		'		'
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options [Roll Forward]	'		'		'		'
Stock-based compensation, balance at beginning of period, number of units	1,332,296		1,332,296		'		'
Stock-based compensation, granted, number of units	0		581,520		'		'
Stock-based compensation, conversions to common stock, number of units	0		0		'		'
Stock-based compensation, forfeited, number of units	0		-15,949		'		'
Stock-based compensation, balance at end of period, number of units	1,332,296		1,897,867		1,332,296		'
Stock-based compensation, balance at beginning of period, weighted-average grant-date fair value	$21.74		$21.74		'		'
Stock-based compensation, granted, weighted-average grant-date fair value	$0		$38.89		'		'
Stock-based compensation, conversions to common stock, weighted-average grant-date fair value	$0		$0		'		'
Stock-based compensation, forfeited, weighted-average grant-date fair value	$0		$29.20		'		'
Stock-based compensation, balance at end of period, weighted-average grant-date fair value	$21.74		$26.93		$21.74		'
Stock-based compensation, aggregate intrinsic value (in dollars)	$51		$106		'		'
Unvested stock-based compensation, balance at beginning of period, number of units	1,187,306		1,187,306		'		'
Stock-based compensation, vested, number of units	0	[1]	-100,585	[1]	'		'
Unvested stock-based compensation, balance at end of period, number of units	1,187,306		1,652,292	[2],[3],[4]	1,187,306		'
Unvested stock-based compensation, balance at beginning of period, weighted-average grant-date fair value (in dollars per share)	$22.06		$22.06		'		'
Stock-based compensation, vested, weighted-average grant-date fair value	$0	[1]	$24.39	[1]	'		'
Unvested stock-based compensation, balance at end of period, weighted-average grant-date fair value (in dollars per share)	$22.06		$27.77	[2],[3],[4]	$22.06		'
Performance stock units granted during period that are earned and subject to requisite service period	'		'		518,438	[1]	559,114	[1]
Performance stock units granted during period that may be earned and subject to requisite service period	'		574,740	[1]	'		'
[1]	Vested performance stock units represent awards where recipients have satisfied retirement-eligibility requirements.
[2]	Includes 518,438 performance stock units granted in fiscal year 2012 that are earned based on the Company's achievement of EPS during the two-year performance period ended November 30, 2013 and are subject to the requisite service period which ends January 2, 2015.
[3]	Includes 559,114 performance stock units granted in fiscal year 2011 that are earned based on the Company's achievement of EPS during the two-year performance period ended November 30, 2012 and are subject to the requisite service period which ended January 2, 2014.
[4]	Includes 574,740 performance stock units granted in calendar year 2013 that may be earned based on the Company's achievement of EPS during the three-year performance period which ends December 31, 2015 and are subject to the requisite service period which ends February 1, 2016.

StockBased_Compensation_Plans_6

Stock-Based Compensation Plans (Schedule of Stock Option Activity) (Details) (Stock Option [Member], USD $)	1 Months Ended		12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2013		Nov. 30, 2012
Stock Option [Member]	'		'		'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'		'		'
Options outstanding, balance at beginning of period, number of units	840,146		538,469		'
Options granted, number of units	0	[1]	0	[1]	'
Options exercised, number of units	-301,677		-366,743		'
Options expired, number of units	0		0		'
Options outstanding, balance at end of period, number of units	538,469		171,726		840,146
Options outstanding, balance at beginning of period, weighted average exercise price	$20.11		$20.82		'
Options granted, weighted average exercise price	$0		$0		'
Options exercised, weighted average exercise price	$18.87		$18.46		'
Options expired, weighted average exercise price	$0		$0		'
Options outstanding, balance at end of period, weighted average exercise price	$20.82		$25.82		$20.11
Options outstanding, weighted-average remaining contractual term (in years)	'1 year 11 months 1 day		'2 years 9 months 4 days		'1 year 9 months 0 days
Options outstanding, aggregate intrinsic value (in dollars)	$10		$5		'
Options vested and exercisable, number of units	'		171,726		'
Options vested and exercisable, weighted average exercise price	'		$25.82		'
Options vested and exercisable, weighted-average remaining contractual term (in years)	'		'2 years 9 months 4 days		'
Options vested and exercisable, aggregate intrinsic value (in dollars)	'		$5		'
[1]	No stock options have been granted by the Company since its spin-off from Morgan Stanley.

StockBased_Compensation_Plans_7

Stock-Based Compensation Plans (Schedule of Intrinsic Value of Options Exercised and Fair Value of Options Vested) (Details) (Stock Options [Member], USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Stock Options [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Intrinsic value of options exercised	$6	$11	$22	$9

Employee_Benefit_Plans_Employe1

Employee Benefit Plans Employee Benefit Plans (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'	'	'
Pretax expense associated with the 401(k) matching, fixed employer and transition credit contributions	$3	$50	$42	$38
Equity Securities [Member]	'	'	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'	'	'
Target asset allocations for 2014	'	45.00%	'	'
Fixed Income Securities [Member]	'	'	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'	'	'
Target asset allocations for 2014	'	55.00%	'	'
Pension Plans, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'	'	'
Asset transfers from level 1 to level 2 within the fair value hierarchy	0	0	0	'
Asset transfers from level 2 to level 1 within the fair value hierarchy	0	0	0	'
Liability transfers from level 1 to level 2 within the fair value hierarchy	0	0	0	'
Liability transfers from level 2 to level 1 within the fair value hierarchy	$0	$0	$0	'

Employee_Benefit_Plans_Employe2

Employee Benefit Plans Employee Benefit Plans (Schedule of Net Periodic Benefit Cost) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Pension Plans, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Service cost, benefits earned during the period	$0	$0	$0	$0
Interest cost on projected benefit obligation	2	21	21	21
Expected return on plan assets	-2	-23	-23	-23
Net amortization	0	5	3	1
Net periodic benefit cost (income)	0	3	1	-1
Other Postretirement Benefit Plans, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Service cost, benefits earned during the period	0	0	1	1
Interest cost on projected benefit obligation	0	1	2	1
Expected return on plan assets	0	0	0	0
Net amortization	0	-1	0	0
Net periodic benefit cost (income)	$0	$0	$3	$2

Employee_Benefit_Plans_Employe3

Employee Benefit Plans Employee Benefit Plans (Schedule of Pretax Amounts Recognized in AOCI Not Recognized as Components of Net Periodic Benefit Cost) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Pension Plans, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Prior service credit (cost)	$7
Net (loss) gain	-186
Total recognized in AOCI	-179
Other Postretirement Benefit Plans, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Prior service credit (cost)	-1
Net (loss) gain	18
Total recognized in AOCI	$17

Employee_Benefit_Plans_Employe4

Employee Benefit Plans Employee Benefit Plans (Schedule of Funded Status and Changes in Benefit Obligations and Fair Value of Plan Assets) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Pension Plans, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]	'	'	'	'
Benefit obligation at beginning of year	$535	$523	'	'
Service cost	0	0	0	0
Interest cost	2	21	21	21
Employee contributions	0	0	'	'
Actuarial (gain) loss	-13	-78	'	'
Plan amendments	0	0	'	'
Benefits paid	-1	-14	'	'
Benefit obligation at end of year	523	452	535	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'	'	'
Fair value of plan assets at beginning of year	368	368	'	'
Actual return on plan assets	1	13	'	'
Employer contributions	0	0	'	'
Employee contributions	0	0	'	'
Benefits paid	-1	-14	'	'
Fair value of plan assets at end of year	368	367	368	'
Funded status (recorded in accrued expenses and other liabilities)	-155	-85	'	'
Other Postretirement Benefit Plans, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]	'	'	'	'
Benefit obligation at beginning of year	13	13	'	'
Service cost	0	0	1	1
Interest cost	0	1	2	1
Employee contributions	0	1	'	'
Actuarial (gain) loss	0	-1	'	'
Plan amendments	0	0	'	'
Benefits paid	0	-1	'	'
Benefit obligation at end of year	13	13	13	'
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'	'	'
Fair value of plan assets at beginning of year	0	0	'	'
Actual return on plan assets	0	0	'	'
Employer contributions	0	0	'	'
Employee contributions	0	1	'	'
Benefits paid	0	-1	'	'
Fair value of plan assets at end of year	0	0	0	'
Funded status (recorded in accrued expenses and other liabilities)	($13)	($13)	'	'

Employee_Benefit_Plans_Employe5

Employee Benefit Plans Employee Benefit Plans (Schedule of Assumptions Used to Determine Benefit Obligations and Net Periodic Benefit Cost) (Details)	1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Pension Plans, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Benefit obligation discount rate	4.09%	4.93%	'	'
Net periodic benefit cost discount rate	3.96%	4.09%	5.07%	5.64%
Net periodic benefit cost expected long-term rate of return on plan assets	6.75%	6.75%	6.75%	6.75%
Other Postretirement Benefit Plans, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Benefit obligation discount rate	4.09%	4.29%	'	'
Net periodic benefit cost discount rate	3.96%	4.09%	5.07%	5.64%

Employee_Benefit_Plans_Employe6

Employee Benefit Plans Employee Benefit Plans (Schedule of Assumed Health Care Cost Trend Rates Used to Determine the Postretirement Benefit Obligations) (Details) (Other Postretirement Benefit Plans, Defined Benefit [Member])	1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]	'	'
Rate to which the cost trend rate is assumed to decline (ultimate trend rate)	5.00%	5.00%
Year that the rate reaches the ultimate trend rate	'2027	'2027
Medical [Member] | Minimum [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Health care cost trend rate assumed for next year	6.90%	6.90%
Medical [Member] | Maximum [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Health care cost trend rate assumed for next year	7.40%	7.30%
Prescription [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Health care cost trend rate assumed for next year	8.40%	'
Prescription [Member] | Minimum [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Health care cost trend rate assumed for next year	'	6.90%
Prescription [Member] | Maximum [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Health care cost trend rate assumed for next year	'	7.30%

Employee_Benefit_Plans_Employe7

Employee Benefit Plans Employee Benefit Plans (Schedule of Pension Plan Assets by Level Within the Fair Value Hierarchy) (Details) (Pension Plans, Defined Benefit [Member], USD $)	Dec. 31, 2013	Dec. 31, 2012	Nov. 30, 2012
In Millions, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	$367	$368	$368
Net asset allocation	100.00%	100.00%	'
Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	71	'
Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	367	297	'
Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	0	'
Registered Investment Company - Domestic Small/Mid Cap Equity Fund [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	32	'	'
Net asset allocation	9.00%	'	'
Registered Investment Company - Domestic Small/Mid Cap Equity Fund [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	'	'
Registered Investment Company - Domestic Small/Mid Cap Equity Fund [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	32	'	'
Registered Investment Company - Domestic Small/Mid Cap Equity Fund [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	'	'
Registered Investment Company - Emerging Markets Equity Fund [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	29	'	'
Net asset allocation	8.00%	'	'
Registered Investment Company - Emerging Markets Equity Fund [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	'	'
Registered Investment Company - Emerging Markets Equity Fund [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	29	'	'
Registered Investment Company - Emerging Markets Equity Fund [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	'	'
Registered Investment Company - Global Low Volatility Equity Fund [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	19	'	'
Net asset allocation	5.00%	'	'
Registered Investment Company - Global Low Volatility Equity Fund [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	'	'
Registered Investment Company - Global Low Volatility Equity Fund [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	19	'	'
Registered Investment Company - Global Low Volatility Equity Fund [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	'	'
Registered Investment Company - International Core Equity Fund [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	46	'	'
Net asset allocation	13.00%	'	'
Registered Investment Company - International Core Equity Fund [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	'	'
Registered Investment Company - International Core Equity Fund [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	46	'	'
Registered Investment Company - International Core Equity Fund [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	'	'
Domestic Large Cap Equity Fund [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	50	68	'
Net asset allocation	13.00%	19.00%	'
Domestic Large Cap Equity Fund [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	0	'
Domestic Large Cap Equity Fund [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	50	68	'
Domestic Large Cap Equity Fund [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	0	'
Common Collective Trust - Domestic Fixed Income Fund [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	7	'	'
Net asset allocation	2.00%	'	'
Common Collective Trust - Domestic Fixed Income Fund [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	'	'
Common Collective Trust - Domestic Fixed Income Fund [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	7	'	'
Common Collective Trust - Domestic Fixed Income Fund [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	'	'
Common Collective Tust - Long Duration Fixed Income Fund [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	181	'	'
Net asset allocation	49.00%	'	'
Common Collective Tust - Long Duration Fixed Income Fund [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	'	'
Common Collective Tust - Long Duration Fixed Income Fund [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	181	'	'
Common Collective Tust - Long Duration Fixed Income Fund [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	'	'
Common Collective Trust - Temporary Investment Fund [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	3	4	'
Net asset allocation	1.00%	1.00%	'
Common Collective Trust - Temporary Investment Fund [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	0	'
Common Collective Trust - Temporary Investment Fund [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	3	4	'
Common Collective Trust - Temporary Investment Fund [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	0	0	'
US Treasury Securities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	47	'
Net asset allocation	'	13.00%	'
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	47	'
US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	0	'
US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	0	'
Corporate Debt Securities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	151	'
Net asset allocation	'	41.00%	'
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	0	'
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	151	'
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	0	'
Registered Investment Company [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	24	'
Net asset allocation	'	6.00%	'
Registered Investment Company [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	24	'
Registered Investment Company [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	0	'
Registered Investment Company [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	0	'
International Equity Fund [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	63	'
Net asset allocation	'	17.00%	'
International Equity Fund [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	0	'
International Equity Fund [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	63	'
International Equity Fund [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	0	'
Domestic Small Cap Equity Fund [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	11	'
Net asset allocation	'	3.00%	'
Domestic Small Cap Equity Fund [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	0	'
Domestic Small Cap Equity Fund [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	11	'
Domestic Small Cap Equity Fund [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair value of plan assets	'	$0	'

Employee_Benefit_Plans_Employe8

Employee Benefit Plans Employee Benefit Plans (Schedule of Expected Benefit Payments for Next Five Years and Thereafter) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Pension Plans, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
2014	$12
2015	13
2016	13
2017	14
2018	15
Following five years thereafter	94
Other Postretirement Benefit Plans, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
2014	1
2015	1
2016	1
2017	1
2018	1
Following five years thereafter	$6

Common_and_Preferred_Stock_Nar

Common and Preferred Stock (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended			0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011	Oct. 16, 2012	Dec. 31, 2013	Mar. 14, 2013	Dec. 31, 2013
					Preferred Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Common Stock [Member]
					Preferred Class B [Member]	Preferred Class B [Member]
Class of Stock [Line Items]	'	'	'	'	'	'	'	'
Preferred stock, shares issued	575,000	575,000	'	'	'	575,000	'	'
Preferred stock, par or stated value per share	$0.01	$0.01	'	'	'	$0.01	'	'
Preferred stock, liquidation preference per share	'	'	'	'	'	$1,000	'	'
Depositary shares represented by one preferred stock share	'	'	'	'	'	40	'	'
Net proceeds from issuance of preferred stock	$0	$0	$560,000,000	$0	$560,000,000	'	'	'
Redemption period of preferred stock following regulatory capital event	'	'	'	'	'	'90 days	'	'
Preferred stock, redemption price per share	'	'	'	'	'	$1,000	'	'
Preferred stock, dividend rate	'	'	'	'	'	6.50%	'	'
Share repurchase program, authorized amount	'	'	'	'	'	'	2,400,000,000	'
Number of shares of stock repurchased during the period	'	'	'	'	'	'	'	27,034,355
Value of stock repurchased during the period	'	'	'	'	'	'	'	$1,300,000,000

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income Accumulated Other Comprehensive Income (Schedule of Changes in Accumulated Other Comprehensive Income (Loss)) (Details) (USD $)

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2012

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2011

Dec. 31, 2012

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2011

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2011

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2011

Nov. 30, 2010

Dec. 31, 2012

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2011

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Net Gain (Loss) From Designated Or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) From Designated Or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) From Designated Or Qualifying Cash Flow Hedges [Member]

Accumulated Translation Adjustment [Member]

Accumulated Translation Adjustment [Member]

Accumulated Translation Adjustment [Member]

Accumulated Translation Adjustment [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

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

($75)

($72)

($52)

($83)

$74

$71

$55

$8

$3

$7

$2

$0

[1]

$0

[1]

$0

[1]

$0

[1]

($152)

($146)

($114)

($93)

Net unrealized gains (losses) on investment securities, net of tax

-3

-52

19

47

-3

-52

19

47

'

'

'

'

'

'

'

'

'

'

'

Unrealized gains (losses) on cash flow hedges, net of tax

0

10

-4

5

'

'

'

'

10

-4

5

'

'

'

'

'

'

'

'

Unrealized foreign currency translation adjustments, net of tax

0

1

0

0

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

Unrealized pension and postretirement plan loss, net of tax

6

45

-38

-21

'

'

'

'

'

'

'

'

'

'

'

6

45

-38

-21

Other comprehensive income (loss)

3

[2]

4

[2]

-23

[2]

31

[2]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accumulated other comprehensive income (loss), balance at end of period, net of tax

-72

-68

-75

-52

71

19

74

55

13

3

7

1

[1]

0

[1]

0

[1]

0

[1]

-146

-101

-152

-114

Other Comprehensive Income (Loss), Tax [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Available for sale investment securities, net unrealized holding losses arising during the period, before tax

'

'

'

'

'

-80

'

'

'

'

'

'

'

'

'

'

'

'

'

Available-for-sale investment securities, amounts reclassified from accumulated other comprehensive income, before tax

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

Available-for-sale investment securities, net change, before tax

-5

-82

30

75

'

-82

'

'

'

'

'

'

'

'

'

'

'

'

'

Available-for-sale investment securities, net unrealized holding losses arising during the period, tax

'

'

'

'

'

30

'

'

'

'

'

'

'

'

'

'

'

'

'

Available-for-sale investment securities, amounts reclassified from accumulated other comprehensive income, tax (expense) benefit

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

Available-for-sale investment securities, net change, tax (expense) benefit

'

'

'

'

-2

30

11

28

'

'

'

'

'

'

'

'

'

'

'

Available-for-sale investment securities, net unrealized holding losses arising during the period, net of tax

'

'

'

'

'

-50

'

'

'

'

'

'

'

'

'

'

'

'

'

Available-for-sale investment securities, amounts reclassified from other comprehensive income, net of tax

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

Available-for-sale investment securities, net change, net of tax

-3

-52

19

47

-3

-52

19

47

'

'

'

'

'

'

'

'

'

'

'

Cash flow hedges, net unrealized gains arising during the period, before tax

'

'

'

'

'

'

'

'

8

'

'

'

'

'

'

'

'

'

'

Cash flow hedges, amounts reclassified from accumulated other comprehensive income, before tax

'

'

'

'

'

'

'

'

8

'

'

'

'

'

'

'

'

'

'

Cash flow hedges, net change, before tax

'

'

'

'

'

'

'

'

16

'

'

'

'

'

'

'

'

'

'

Cash flow hedges, net unrealized gains arising during the period, tax (expense) benefit

'

'

'

'

'

'

'

'

-3

'

'

'

'

'

'

'

'

'

'

Cash flow hedges, amounts reclassified from accumulated other comprehensive income, tax (expense) benefit

'

'

'

'

'

'

'

'

-3

'

'

'

'

'

'

'

'

'

'

Cash flow hedges, net change, tax (expense) benefit

'

'

'

'

'

'

'

'

-6

-2

3

'

'

'

'

'

'

'

'

Cash flow hedges, net unrealized gains arising during the period, net of tax

'

'

'

'

'

'

'

'

5

'

'

'

'

'

'

'

'

'

'

Cash flow hedges, amounts reclassified from accumulated other comprehensive income, net of tax

'

'

'

'

'

'

'

'

5

'

'

'

'

'

'

'

'

'

'

Cash flow hedges, net change, net of tax

0

10

-4

5

'

'

'

'

10

-4

5

'

'

'

'

'

'

'

'

Foreign currency translation adjustments, net unrealized gains arising during the period, before tax

'

'

'

'

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

Foreign currency translation adjustments, net change, before tax

'

'

'

'

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

Foreign currency translation adjustments, net unrealized gains arising during the period, tax (expense) benefit

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

Foreign currency translation adjustments, net change, tax (expense) benefit

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

Foreign currency translation adjustments, net unrealized gains arising during the period, net of tax

'

'

'

'

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

Foreign currency translation adjustments, net change, net of tax

0

1

0

0

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

Pension and postretirement plan, unrealized gains arising during the period, before tax

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-72

'

'

Pension and postretirement plan, net change, before tax

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

72

'

'

Pension and post retirement plan, net pension and postretirement plan gains during the period, tax (expense) benefit

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-27

'

'

Pension and post retirement plan, net change, tax (expense) benefit

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-4

-27

25

12

Other comprehensive income (loss), before reclassifications, net of tax

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

45

'

'

Pension and postretirement plan, net change, net of tax

$6

$45

($38)

($21)

'

'

'

'

'

'

'

'

'

'

'

$6

$45

($38)

($21)

[1]

Includes unrealized losses on hedge of net investment in foreign subsidiary, net of tax benefit and net gains on foreign currency translation adjustments.

[2]

In February 2013, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. ASU 2013-02 requires an entity to report the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in the consolidated statements of income if the amount being reclassified is required to be reclassified in its entirety to net income. For amounts that are not required to be reclassified to net income in their entirety in the same reporting period, an entity is required to cross-reference other disclosures that provide additional detail about those amounts. As the result, the Company has adjusted its AOCI presentation prospectively, as required, and therefore additional table was included to present the required information for the current period and the presentation has changed from historical periods.

Other_Income_and_Other_Expense1

Other Income and Other Expense (Schedule of Other Income) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Component of Other Income [Abstract]	'	'	'	'
Royalty and licensee revenue	$6	$68	$72	$72
Merchant fees	3	44	17	16
Transition service agreement revenue	1	6	12	27
Gain from sales of merchant contracts	0	0	3	11
Other income	9	51	59	53
Total other income	$19	$169	$163	$179

Other_Income_and_Other_Expense2

Other Income and Other Expense (Schedule of Other Expense) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Component of Other Expense [Abstract]	'	'	'	'
Postage	$7	$86	$85	$82
Fraud losses	9	110	93	72
Supplies	2	26	22	23
Credit related inquiry fees	1	19	20	17
Litigation expense	0	-12	218	22
Incentive expense	5	61	59	23
Other expense	11	198	107	101
Total other expense	$35	$488	$604	$340

Income_Taxes_Income_Taxes_Narr

Income Taxes Income Taxes (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Operating Loss Carryforwards [Line Items]	'	'	'	'
Deferred tax assets, valuation allowance	$0	$37	'	'
Interest and penalties related to unrecognized tax benefts, change from prior year	2	17	20	11
Interest and penalties related to unrecognized tax benefits	101	118	99	79
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	'	101	'	'
Foreign Tax Authority [Member]	'	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'	'
Operating Loss Carryforwards	'	$89	'	'

Income_Taxes_Schedule_of_Incom

Income Taxes (Schedule of Income Tax Expense) (Details) (USD $)

1 Months Ended

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Nov. 30, 2012

Aug. 31, 2012

31-May-12

Feb. 29, 2012

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2011

Current Income Tax Expense (Benefit), Continuing Operations [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

Current, U.S. federal

$101

'

'

'

'

'

'

'

'

'

$1,059

$1,109

$931

Current, U.S. state and local

15

'

'

'

'

'

'

'

'

'

87

149

118

Current, international

0

'

'

'

'

'

'

'

'

'

6

4

3

Total current

116

'

'

'

'

'

'

'

'

'

1,152

1,262

1,052

Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred, U.S. federal

-11

'

'

'

'

'

'

'

'

'

295

136

228

Deferred, U.S. state and local

-1

'

'

'

'

'

'

'

'

'

27

10

4

Total deferred

-12

'

'

'

'

'

'

'

'

'

322

146

232

Income tax expense

$104

$99

$335

$353

$379

$407

$309

$385

$330

$384

$1,474

$1,408

$1,284

Income_Taxes_Schedule_of_Recon

Income Taxes (Schedule of Reconciliation the Effective Tax Rate to the U.S. Federal Statutory Income Tax Rate) (Details)	1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Effective Income Tax Rate Reconciliation, Percent [Abstract]	'	'	'	'
U.S. federal statutory income tax rate	35.00%	35.00%	35.00%	35.00%
U.S. state, local and other income taxes, net of U.S. federal income tax benefits	3.20%	2.20%	2.90%	2.40%
Valuation allowance, capital loss	0.00%	0.00%	0.00%	-0.60%
Other	-0.10%	0.20%	-0.40%	-0.20%
Effective income tax rate	38.10%	37.40%	37.50%	36.60%

Income_Taxes_Income_Taxes_Sche

Income Taxes Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Income Tax Disclosure [Abstract]	'	'
Deferred tax assets, allowance for loan losses	$627	$673
Deferred tax assets, customer fees and rewards	212	372
Deferred tax assets, compensation and benefits	87	104
Deferred tax assets, state income taxes	65	71
Deferred tax assets, legal reserves	13	83
Deferred tax assets, other	59	37
Total deferred tax assets before valuation allowance	1,063	1,340
Deferred tax assets, valuation allowance	-37	0
Total deferred tax assets, net of valuation allowance	1,026	1,340
Deferred tax liabilities, debt exchange premium	-98	-107
Deferred tax liabilities, depreciation and software amortization	-83	-60
Deferred tax liabilities, unearned income	-40	-38
Deferred tax liabilities, intangible assets	-22	-22
Deferred tax liabilities, deferred loan acquisition costs	-16	-12
Deferred tax liabilities, unrealized gain/loss	-8	-15
Deferred tax liabilities, other	-5	-11
Total deferred tax liabilities	-272	-265
Net deferred tax assets	$754	$1,075

Income_Taxes_Income_Taxes_Sche1

Income Taxes Income Taxes (Schedule of Reconciliation of Beginning and Ending Unrecognized Tax Benefits) (Details) (USD $)	1 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2013		Nov. 30, 2012		Nov. 30, 2011
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]	'		'		'		'
Unrecognized tax benefits, balance at beginning of period	$573	[1]	$575	[1]	$507	[1]	$373
Unrecognized tax benefits, additions, current period tax positions	2		1		74		74
Unrecognized tax benefits, additions, prior year tax positions	0		142		1		154
Unrecognized tax benefits, reductions, prior year tax positions	0		-69		-5		-83
Unrecognized tax benefits, reductions, settlements with taxing authorities	0		-18		-2		-9
Unrecognized tax benefits, reductions, expired statute of limitations	0		-2		-2		-2
Unrecognized tax benefits, balance at end of period	575	[1]	629	[1]	573	[1]	507	[1]
Unrecognized tax benefits that would favorably affect the effective tax rate	$109		$142		$108		$97
[1]	(1)At December 31, 2013, November 30, 2012 and 2011 and December 31, 2012, amounts included $142 million, $108 million, $97 million and $109 million respectively, of unrecognized tax benefits, which, if recognized, would favorably affect the effective tax rate.

Earnings_Per_Share_Schedule_of

Earnings Per Share (Schedule of Basic and Diluted EPS) (Details) (USD $)

1 Months Ended

3 Months Ended

12 Months Ended

In Millions, except Per Share data, unless otherwise specified

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Nov. 30, 2012

Aug. 31, 2012

31-May-12

Feb. 29, 2012

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2011

Earnings Per Share Reconciliation [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income

$170

$164

$602

$593

$602

$673

$551

$627

$537

$630

$2,470

$2,345

$2,227

Preferred stock dividends

0

'

'

'

'

'

'

'

'

'

-37

-5

0

Net income available to common stockholders

170

'

'

'

'

'

'

'

'

'

2,433

2,340

2,227

Income allocated to participating securities

-2

'

'

'

'

'

'

'

'

'

-19

-22

-25

Net Income allocated to common stockholders

$168

$162

$588

[1]

$579

[1]

$588

[1]

$659

[1]

$541

[1]

$621

[1]

$532

[1]

$624

[1]

$2,414

$2,318

$2,202

Weighted Average Number of Shares Outstanding Reconciliation [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted average shares of common stock outstanding

498

529

'

'

'

'

'

'

'

'

485

519

542

Effect of dilutive common stock equivalents

1

'

'

'

'

'

'

'

'

'

2

1

1

Weighted average shares of common stock outstanding and common stock equivalents

499

530

'

'

'

'

'

'

'

'

487

520

543

Basic earnings per common share (in dollars per share)

$0.34

$0.31

$1.24

[1]

$1.20

[1]

$1.20

[1]

$1.33

[1]

$1.08

[1]

$1.21

[1]

$1.01

[1]

$1.18

[1]

$4.97

$4.47

$4.06

Diluted earnings per common share (in dollars per share)

$0.34

$0.30

$1.23

[1]

$1.20

[1]

$1.20

[1]

$1.33

[1]

$1.07

[1]

$1.21

[1]

$1

[1]

$1.18

[1]

$4.96

$4.46

$4.06

[1]

Because the inputs to net income allocated to common stockholders and earnings per share are calculated using weighted averages for the quarter, the sum of all four quarters may differ from the year to date amounts in the consolidated statements of income.

Capital_Adequacy_Capital_Adequ

Capital Adequacy Capital Adequacy (Narrative) (Details) (Discover Bank [Member], USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Discover Bank [Member]	'	'	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'	'	'
Cash dividends paid to parent company	$0	$1,600	$1,500	$1,400

Capital_Adequacy_Schedule_of_M

Capital Adequacy (Schedule of Minimum and Well-Capitalized Requirements) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Parent Company [Member]	'	'
Compliance with Regulatory Capital Requirements [Line Items]	'	'
Total capital to risk-weighted assets, actual amount	$11,975	$10,998
Total capital to risk-weighted assets, actual ratio	17.40%	16.80%
Total capital to risk-weighted assets, minimum capital requirements, amount	5,492	5,242
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	6,865	6,552
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	10,409	9,470
Tier I capital to risk-weighted assets, actual ratio	15.20%	14.50%
Tier I capital to risk-weighted assets, minimum capital requirements, amount	2,746	2,621
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	4,119	3,931
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 ratio, actual ratio	13.40%	12.70%
Tier I capital to average assets ratio, minimum capital requirements, amount	3,116	2,987
Tier I capital to average assets ratio, minimum capital requirements, ratio	4.00%	4.00%
Tier I capital to average assets ratio, capital requirements to be classified as well-capitalize, amount	3,895	3,734
Tier I capital to average assets ratio, 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	10,496	9,615
Total capital to risk-weighted assets, actual ratio	15.50%	14.90%
Total capital to risk-weighted assets, minimum capital requirements, amount	5,428	5,172
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	6,785	6,465
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	8,941	8,097
Tier I capital to risk-weighted assets, actual ratio	13.20%	12.50%
Tier I capital to risk-weighted assets, minimum capital requirements, amount	2,714	2,586
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	4,071	3,879
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 ratio, actual ratio	11.60%	11.00%
Tier I capital to average assets ratio, minimum capital requirements, amount	3,077	2,936
Tier I capital to average assets ratio, minimum capital requirements, ratio	4.00%	4.00%
Tier I capital to average assets ratio, capital requirements to be classified as well-capitalize, amount	$3,847	$3,670
Tier I capital to average assets ratio, capital requirements to be classified as well-capitalize, ratio	5.00%	5.00%

Commitments_Contingencies_and_2

Commitments, Contingencies and Guarantees (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Commitments, Contingencies and Guarantees [Line Items]	'	'	'	'
Operating lease agreements rent expense	$3,000,000	$15,000,000	$18,000,000	$16,000,000
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	'	$162,800,000,000	'	'

Commitments_Contingencies_and_3

Commitments, Contingencies and Guarantees (Schedule of Lease Commitments) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Capital Leases, Future Minimum Payments Due [Abstract]	'
2014, capitalized leases	$1
2015, capitalized leases	0
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	15
2015, operating leases	11
2016, operating leases	10
2017, operating leases	9
2018, operating leases	6
Thereafter, operating leases	7
Total minimum lease payments, operating leases	$58

Commitments_Contingencies_and_4

Commitments, Contingencies and Guarantees (Schedule of Maximum Potential Counterparty Exposures Related to Settlement Guarantees) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Merchant Guarantee [Member] | Diners Club [Member]	'
Guarantor Obligations [Line Items]	'
Maximum potential counterparty exposures to settlement guarantees	$144
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 $)	1 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2013		Nov. 30, 2012		Nov. 30, 2011
Merchant Chargebacks [Member]	'		'		'		'
Loss Contingencies [Line Items]	'		'		'		'
Aggregate sales transaction volume	$11,521	[1]	$120,442	[1]	$114,847	[1]	$108,225	[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 $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Commitments Contingencies and Guarantees [Abstract]	'	'
Settlement withholdings and escrow deposits	$17	$25

Litigation_and_Regulatory_Matt1

Litigation and Regulatory Matters (Details) (USD $)	1 Months Ended	12 Months Ended				0 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011	Dec. 31, 2013	Mar. 06, 2012	Mar. 06, 2012	Dec. 31, 2013
					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]	'	'	'	'	'	'	'	'
Litigation expense excluding legal service providers	$0	($12,000,000)	$218,000,000	$22,000,000	'	'	'	'
Maximum aggregate reasonably possible losses	'	'	'	'	'	'	'	150,000,000
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 $)	1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Nov. 30, 2012
			Residential Mortgage Backed Securities [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	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	$0
Asset transfers from level 2 to level 1 within the fair value hierarchy	'	'	'	0	0	0
Liability transfers from level 1 to level 2 within the fair value hierarchy	'	'	'	0	0	0
Liability transfers from level 2 to level 1 within the fair value hierarchy	'	'	'	0	0	0
Available for sale security, par value	'	'	1,300,000,000	'	'	'
Available for sale securities, weighted average coupon rate	'	'	2.83%	'	'	'
Available for sale securities, weighted average remaining maturity	'	'	'4 years	'	'	'
Aggregate unpaid principal balance of loans held for sale, fair value option	337,000,000	146,000,000	'	'	'	'
Fair value of loans held for sale	355,000,000	148,000,000	'	'	'	'
Gain (loss) from fair value adjustments on loans held for sale	$1,000,000	($37,000,000)	'	'	'	'

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 $)	Dec. 31, 2013	Dec. 31, 2012
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	$4,931	$6,145
Mortgage loans held for sale, fair value	148	355
Derivative financial instruments, assets	79	111
Derivative financial instruments, liabilities	7	3
Interest Rate Lock Commitments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets	4	12
Forward Contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets	5	1
Derivative financial instruments, liabilities	1	2
Other Derivative Financial Instruments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets	70	98
Derivative financial instruments, liabilities	6	1
US Treasury Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	2,057	2,459
U.S. Government Agency Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	1,561	2,233
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	151
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	1,307	1,302
Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	3,618	4,692
Mortgage loans held for sale, fair value	0	0
Derivative financial instruments, assets	0	0
Derivative financial instruments, liabilities	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	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	0	0
Derivative financial instruments, liabilities	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	0	0
Derivative financial instruments, liabilities	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	2,057	2,459
Level 1 [Member] | U.S. Government Agency Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale investment securities, fair value	1,561	2,233
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	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	1,313	1,453
Mortgage loans held for sale, fair value	148	355
Derivative financial instruments, assets	75	99
Derivative financial instruments, liabilities	7	3
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	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	5	1
Derivative financial instruments, liabilities	1	2
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	70	98
Derivative financial instruments, liabilities	6	1
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] | U.S. Government Agency 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	151
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	1,307	1,302
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	4	12
Derivative financial instruments, liabilities	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	4	12
Level 3 [Member] | Forward Contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative financial instruments, assets	0	0
Derivative financial instruments, liabilities	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	0	0
Derivative financial instruments, liabilities	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] | U.S. Government Agency 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	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 $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012
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	$15	$12	$0
Transfers into Level 3	0	0	0
Transfers out of Level 3	0	0	0
Total net gains (losses) included in earnings	17	121	110
Purchases	0	0	5
Sales	0	0	0
Settlements	1	3	2
Transfers of IRLC's to closed loans	-21	-132	-102
Level 3 assets and liabilities, balance at end of period	12	4	15
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	0
Transfers into Level 3	'	0	0
Transfers out of Level 3	'	-3	-1
Total net gains (losses) included in earnings	'	3	1
Purchases	'	0	0
Sales	'	0	0
Settlements	'	0	0
Transfers of IRLC's to closed loans	'	0	0
Level 3 assets and liabilities, balance at end of period	'	0	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	'
Transfers into Level 3	'	3	'
Transfers out of Level 3	'	0	'
Total net gains (losses) included in earnings	'	0	'
Purchases	'	1	'
Sales	'	-3	'
Settlements	'	-1	'
Transfers of IRLC's to closed loans	'	0	'
Level 3 assets and liabilities, balance at end of period	'	$0	'

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 $)	Dec. 31, 2013	Dec. 31, 2012	Nov. 30, 2012	Nov. 30, 2011	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013
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)	$4	$12	$15	$0	'	'	'	'	'
Significant unobservable inputs, valuation technique	'	'	'	'	'Quantitative risk models	'	'	'	'
Significant unobservable inputs, significant unobservable input	'	'	'	'	'	'Loan funding probability	'	'	'
Significant unobservable inputs, ranges of inputs	'	'	'	'	'	'	15.00%	100.00%	60.00%	[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 $)	Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	$58	[1]	$89	[1]
Fair Value, Measurements, Nonrecurring [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	58		89
Cash and cash equivalents	6,554		2,584
Restricted cash	182		290
Net loan receivables	64,968	[2]	62,619	[2]
Accrued interest receivables	556		500
Deposits	45,231		42,671
Short-term borrowings	140		327
Accrued interest payables	117		126
Fair Value, Measurements, Nonrecurring [Member] | Variable Interest Entity, Primary Beneficiary [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Long-term borrowings	17,283		16,370
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	3,935		2,334
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 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	14		34
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	43		54
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	60		87
Cash and cash equivalents	6,554		2,584
Restricted cash	182		290
Net loan receivables	63,975	[2]	60,455	[2]
Accrued interest receivables	556		500
Deposits	44,959		42,213
Short-term borrowings	140		327
Accrued interest payables	117		126
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	16,986		15,933
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	3,488		1,733
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 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	15		34
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	44		52
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	6,554		2,584
Restricted cash	182		290
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 [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 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	57		88
Cash and cash equivalents	0		0
Restricted cash	0		0
Net loan receivables	0	[2]	0	[2]
Accrued interest receivables	556		500
Deposits	45,231		42,671
Short-term borrowings	140		327
Accrued interest payables	117		126
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	15,312		14,033
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	3,934		2,332
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 [Member]	'		'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'		'
Held-to-maturity investment securities, fair value	14		34
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	43		54
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	64,968	[2]	62,619	[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	1,971		2,337
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		2
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 [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] | 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 excludes 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 $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Derivative [Line Items]	'
Additional collateral	$103
Credit Rating Did Not Meet Specified Threshold [Member]	'
Derivative [Line Items]	'
Cash collateral posted	4
Interest Expense [Member]	'
Derivative [Line Items]	'
Cash flow hedge pretax loss to be reclassified to earnings within twelve months	$23
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)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

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]

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]

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]

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]

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]

USD ($)

USD ($)

Other Assets [Member]

Other Assets [Member]

Other Liabilities [Member]

Other Liabilities [Member]

USD ($)

CHF

EUR (€)

GBP (£)

SGD

USD ($)

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 ($)

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 ($)

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

'

'

$2,650

$1,750

'

'

'

'

$7,138

$7,859

'

'

'

'

$35

[1]

€ 26

$0

[1]

'

'

'

'

$796

[2]

$1,027

[2]

'

'

'

'

$44

[3]

5

€ 20

£ 6

1

$40

[3]

€ 18

£ 9

2

'

'

'

'

$693

$774

'

'

'

'

$235

[2]

$414

[2]

'

'

'

'

$40

Derivative, number of transactions (in transations)

'

'

5

'

'

'

'

'

244

'

'

'

'

'

1

1

'

'

'

'

'

1

[2]

'

'

'

'

'

8

8

8

8

8

'

'

'

'

'

'

'

'

478

'

'

'

'

'

1,107

[2]

'

'

'

'

'

1

Derivative, other assets (at fair value)

79

[4]

111

'

'

18

5

'

'

'

'

52

93

'

'

'

'

'

0

0

'

'

'

'

0

[2]

0

[2]

'

'

'

'

'

'

'

'

'

'

'

0

0

'

'

'

'

5

1

'

'

'

'

4

[2]

12

[2]

'

'

'

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

-61

[5]

-92

[5]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total net derivative assets

18

19

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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

7

[4]

3

'

'

'

'

0

0

'

'

'

'

6

0

'

'

'

'

'

0

0

'

'

'

'

0

[2]

1

[2]

'

'

'

'

'

'

'

'

'

'

'

0

0

'

'

'

'

1

2

'

'

'

'

0

[2]

0

[2]

'

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

-7

[5]

0

[5]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total net derivative liabilities

$0

$3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

The foreign exchange forward contract has a notional amounts of EUR 26 million as of December 31, 2013.

[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 20 million, GBP 6 million, SGD 1 million and CHF 5 million as of December 31, 2013 and EUR 18 million and GBP 9 million and SGD 2 million as of December 31, 2012.

[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 $40 million and an immaterial fair value as of December 31, 2013.

[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 $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013		Nov. 30, 2012	Nov. 30, 2011
Designated as Hedges [Member] | Cash Flow Hedging [Member] | Interest Rate Swap [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	($1)	$13	[1]	($6)	$7
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	-1	13	[1]	-6	7
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	1	4	[1]	7	8
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	0	-12	[1]	0	0
Designated as Hedges [Member] | Fair Value Hedging [Member] | Interest Expense [Member]	'	'		'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'		'	'
Gain (loss) on derivatives	4	32	[1]	37	21
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	10	51	[1]	-52	-30
Interest expense - other, interest rate swaps-fair value hedges	-1	-6	[1]	-6	-7
Gain (loss) on hedged item	9	45	[1]	-58	-37
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	-9	-46	[1]	58	37
Interest expense - other, interest rate swaps-fair value hedges	3	41	[1]	30	13
Gain (loss) on derivatives	-6	-5	[1]	88	50
Not Designated as Hedges [Member]	'	'		'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'		'	'
Gain (loss) on derivatives	18	123	[1]	103	-5
Not Designated as Hedges [Member] | Interest Rate Swap [Member] | Other Income	'	'		'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'		'	'
Gain (loss) on derivatives	0	-1	[1]	-7	-5
Not Designated as Hedges [Member] | Foreign Exchange Forward [Member] | Other Income	'	'		'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'		'	'
Gain (loss) on derivatives	-1	-1	[1]	1	0
Not Designated as Hedges [Member] | Forward Contracts [Member] | Other Income	'	'		'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'		'	'
Gain (loss) on derivatives	2	4	[1]	-1	0
Not Designated as Hedges [Member] | Interest Rate Lock Commitments [Member] | Other Income	'	'		'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'		'	'
Gain (loss) on derivatives	$17	$121	[1]	$110	$0
[1]	The impact of the net investment hedge on the consolidated statements of income, which arise from amounts reclassified from other comprehensive income, was immaterial for the calendar year ended December 31, 2013.

Segment_Disclosures_Narrative_

Segment Disclosures (Narrative) (Details)	12 Months Ended
	Dec. 31, 2013
	segment
Segment Reporting [Abstract]	'
Number of reportable segments	2

Segment_Disclosures_Schedule_o

Segment Disclosures (Schedule of Segment Disclosures) (Details) (USD $)

1 Months Ended

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Nov. 30, 2012

Aug. 31, 2012

31-May-12

Feb. 29, 2012

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2011

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

$595

'

$1,842

$1,787

$1,727

$1,708

$1,706

$1,695

$1,656

$1,646

$7,064

$6,703

$6,345

Interest expense

103

'

273

278

297

298

312

325

341

353

1,146

1,331

1,485

Net interest income

492

442

1,569

1,509

1,430

1,410

1,394

1,370

1,315

1,293

5,918

5,372

4,860

Provision for loan losses

178

173

354

333

240

159

338

126

232

152

1,086

848

1,013

Other income

200

211

'

'

'

'

'

'

'

'

2,306

2,281

2,205

Other expense

240

217

838

783

820

753

800

826

749

677

3,194

3,052

2,541

Income before income tax expense

274

263

937

946

981

1,080

860

1,012

867

1,014

3,944

3,753

3,511

Direct Banking [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

595

'

'

'

'

'

'

'

'

'

7,064

6,703

6,345

Interest expense

103

'

'

'

'

'

'

'

'

'

1,146

1,331

1,485

Net interest income

492

'

'

'

'

'

'

'

'

'

5,918

5,372

4,860

Provision for loan losses

178

'

'

'

'

'

'

'

'

'

1,069

848

1,013

Other income

169

'

'

'

'

'

'

'

'

'

1,976

1,939

1,907

Other expense

224

'

'

'

'

'

'

'

'

'

2,961

2,891

2,409

Income before income tax expense

259

'

'

'

'

'

'

'

'

'

3,864

3,572

3,345

Payment Services [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

0

'

'

'

'

'

'

'

'

'

0

0

0

Interest expense

0

'

'

'

'

'

'

'

'

'

0

0

0

Net interest income

0

'

'

'

'

'

'

'

'

'

0

0

0

Provision for loan losses

0

'

'

'

'

'

'

'

'

'

17

0

0

Other income

31

'

'

'

'

'

'

'

'

'

330

342

298

Other expense

16

'

'

'

'

'

'

'

'

'

233

161

132

Income before income tax expense

15

'

'

'

'

'

'

'

'

'

80

181

166

Credit Card Receivable [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

510

'

'

'

'

'

'

'

'

'

5,978

5,751

5,654

Provision for loan losses

165

'

'

'

'

'

'

'

'

'

893

724

897

Credit Card Receivable [Member] | Direct Banking [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

510

'

'

'

'

'

'

'

'

'

5,978

5,751

5,654

Credit Card Receivable [Member] | Payment Services [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

0

'

'

'

'

'

'

'

'

'

0

0

0

Private Student Loans [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

18

'

'

'

'

'

'

'

'

'

252

184

115

Private Student Loans [Member] | Direct Banking [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

18

'

'

'

'

'

'

'

'

'

252

184

115

Private Student Loans [Member] | Payment Services [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

0

'

'

'

'

'

'

'

'

'

0

0

0

PCI Student Loans [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

24

'

'

'

'

'

'

'

'

'

272

303

225

PCI Student Loans [Member] | Direct Banking [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

24

'

'

'

'

'

'

'

'

'

272

303

225

PCI Student Loans [Member] | Payment Services [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

0

'

'

'

'

'

'

'

'

'

0

0

0

Personal Loans [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

34

'

'

'

'

'

'

'

'

'

464

363

266

Personal Loans [Member] | Direct Banking [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

34

'

'

'

'

'

'

'

'

'

464

363

266

Personal Loans [Member] | Payment Services [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

0

'

'

'

'

'

'

'

'

'

0

0

0

Other [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

9

'

'

'

'

'

'

'

'

'

98

102

85

Other [Member] | Direct Banking [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

9

'

'

'

'

'

'

'

'

'

98

102

85

Other [Member] | Payment Services [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

$0

'

'

'

'

'

'

'

'

'

$0

$0

$0

Parent_Company_Condensed_Finan2

Parent Company Condensed Financial Information Parent Company Condensed Financial Information (Narrative) (Details) (Parent Company [Member])	Dec. 31, 2013
Parent Company [Member]	'
Condensed Financial Statements, Captions [Line Items]	'
Threshold for parent company financial information disclosure	25.00%

Parent_Company_Condensed_Finan3

Parent Company Condensed Financial Information (Schedule of Parent Company Condensed Statements of Financial Condition) (Details) (USD $)	1 Months Ended		12 Months Ended
	Dec. 31, 2012		Dec. 31, 2013		Nov. 30, 2012	Nov. 30, 2011	Dec. 31, 2011	Nov. 30, 2010
Assets	'		'		'	'	'	'
Cash and cash equivalents	$2,584,000,000		$6,554,000,000		$3,926,000,000	$2,850,000,000	'	$5,099,000,000
Other assets	2,562,000,000		2,367,000,000		'	'	'	'
Total assets	73,491,000,000		79,340,000,000		'	'	69,473,000,000	'
Liabilities and Stockholders’ Equity	'		'		'	'	'	'
Non-interest bearing deposit accounts	136,000,000		193,000,000		'	'	'	'
Interest-bearing deposit accounts	42,077,000,000		44,766,000,000		'	'	'	'
Total deposits	42,213,000,000		44,959,000,000		'	'	'	'
Other long-term borrowings	17,666,000,000		20,474,000,000		'	'	18,265,000,000	'
Accrued expenses and other liabilities	3,412,000,000		2,958,000,000		'	'	'	'
Total liabilities	63,618,000,000		68,531,000,000		'	'	61,115,000,000	'
Stockholders' equity	9,873,000,000		10,809,000,000		9,778,000,000	8,242,000,000	8,358,000,000	6,457,000,000
Total liabilities and stockholders' equity	73,491,000,000		79,340,000,000		'	'	'	'
Premium paid on debt exchange	0		0		291,000,000	0	'	'
Parent Company [Member]	'		'		'	'	'	'
Assets	'		'		'	'	'	'
Cash and cash equivalents	41,000,000		4,000,000		1,000,000	1,000,000	'	1,000,000
Notes receivable from subsidiaries	2,225,000,000		2,254,000,000	[1]	'	'	'	'
Investments in subsidiaries	8,947,000,000		9,824,000,000		'	'	'	'
Other assets	133,000,000		158,000,000		'	'	'	'
Total assets	11,346,000,000		12,240,000,000		'	'	'	'
Liabilities and Stockholders’ Equity	'		'		'	'	'	'
Non-interest bearing deposit accounts	3,000,000		6,000,000		'	'	'	'
Interest-bearing deposit accounts	17,000,000		7,000,000		'	'	'	'
Total deposits	20,000,000		13,000,000		'	'	'	'
Short-term borrowings from subsidiaries	88,000,000		146,000,000		'	'	'	'
Other long-term borrowings	1,035,000,000	[2]	1,045,000,000		'	'	'	'
Accrued expenses and other liabilities	330,000,000		227,000,000		'	'	'	'
Total liabilities	1,473,000,000		1,431,000,000		'	'	'	'
Stockholders' equity	9,873,000,000		10,809,000,000		'	'	'	'
Total liabilities and stockholders' equity	11,346,000,000		12,240,000,000		'	'	'	'
Premium paid on debt exchange	0		0		115,000,000	0	'	'
Discover Bank [Member]	'		'		'	'	'	'
Liabilities and Stockholders’ Equity	'		'		'	'	'	'
Premium paid on debt exchange	'		'		176,000,000	'	'	'
Discover Bank [Member] | Parent Company [Member]	'		'		'	'	'	'
Assets	'		'		'	'	'	'
Notes receivable from subsidiaries	'		1,800,000,000		'	'	'	'
Liabilities and Stockholders’ Equity	'		'		'	'	'	'
Liquidity available to parent from funds advanced to subsidiary	'		1,800,000,000		'	'	'	'
Senior Notes [Member] | Parent Company [Member]	'		'		'	'	'	'
Liabilities and Stockholders’ Equity	'		'		'	'	'	'
Outstanding aggregate principal amount exchanged	'		'		$500,000,000	'	'	'
[1]	The Parent Company advanced $1.8 billion to Discover Bank as of December 31, 2013, which is included in notes receivables from subsidiaries. The $1.8 billion is available to the Parent for liquidity purposes.
[2]	During the 2012 fiscal year, the Company completed a private exchange offer, resulting in the exchange of $500 million outstanding aggregate principal amount of subordinated debt issued by a subsidiary for the same aggregate principal amount of new senior notes issued by the Parent. A cash premium of $176 million paid by the subsidiary to bondholders tendering its subordinated notes under the exchange offer is reported as a component of the new senior notes and is thus included in other long term borrowings of the Parent.

Parent_Company_Condensed_Finan4

Parent Company Condensed Financial Information (Schedule of Parent Company Condensed Statements of Income) (Details) (USD $)

1 Months Ended

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Nov. 30, 2012

Aug. 31, 2012

31-May-12

Feb. 29, 2012

Dec. 31, 2013

Nov. 30, 2012

Nov. 30, 2011

Condensed Financial Statements, Captions [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

$595

'

$1,842

$1,787

$1,727

$1,708

$1,706

$1,695

$1,656

$1,646

$7,064

$6,703

$6,345

Interest expense

103

'

273

278

297

298

312

325

341

353

1,146

1,331

1,485

Net interest income

492

442

1,569

1,509

1,430

1,410

1,394

1,370

1,315

1,293

5,918

5,372

4,860

Other income

19

'

'

'

'

'

'

'

'

'

169

163

179

Employee compensation and benefits

87

'

'

'

'

'

'

'

'

'

1,164

1,048

914

Professional fees

34

'

'

'

'

'

'

'

'

'

410

432

415

Other

35

'

'

'

'

'

'

'

'

'

488

604

340

Total other (benefit) expense

240

217

838

783

820

753

800

826

749

677

3,194

3,052

2,541

Income before income tax expense

274

263

937

946

981

1,080

860

1,012

867

1,014

3,944

3,753

3,511

Income tax (expense) benefit

-104

-99

-335

-353

-379

-407

-309

-385

-330

-384

-1,474

-1,408

-1,284

Net income

170

164

602

593

602

673

551

627

537

630

2,470

2,345

2,227

Premium paid on debt exchange

0

'

'

'

'

'

'

'

'

'

0

291

0

Discover Bank [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Condensed Financial Statements, Captions [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Premium paid on debt exchange

'

'

'

'

'

'

'

'

'

'

'

176

'

Parent Company [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Condensed Financial Statements, Captions [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest income

2

'

'

'

'

'

'

'

'

'

22

22

23

Interest expense

7

'

'

'

'

'

'

'

'

'

84

52

61

Net interest income

-5

'

'

'

'

'

'

'

'

'

-62

-30

-38

Dividends from subsidiaries

0

'

'

'

'

'

'

'

'

'

1,600

1,500

1,375

Other income

0

'

'

'

'

'

'

'

'

'

0

0

3

Total income (loss)

-5

'

'

'

'

'

'

'

'

'

1,538

1,470

1,340

Employee compensation and benefits

0

'

'

'

'

'

'

'

'

'

0

0

2

Professional fees

0

'

'

'

'

'

'

'

'

'

3

1

0

Other

0

'

'

'

'

'

'

'

'

'

1

-171

[1]

2

Total other (benefit) expense

0

'

'

'

'

'

'

'

'

'

4

-170

4

Income before income tax expense

-5

'

'

'

'

'

'

'

'

'

1,534

1,640

1,336

Income tax (expense) benefit

2

'

'

'

'

'

'

'

'

'

17

-54

16

Equity in undistributed net income of subsidiaries

173

'

'

'

'

'

'

'

'

'

919

759

875

Net income

170

'

'

'

'

'

'

'

'

'

2,470

2,345

2,227

Premium paid on debt exchange

0

'

'

'

'

'

'

'

'

'

0

115

0

Parent Company [Member] | Senior Notes [Member]

'

'

'

'

'

'

'

'

'

'

'

'

'

Condensed Financial Statements, Captions [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Outstanding aggregate principal amount exchanged

'

'

'

'

'

'

'

'

'

'

'

$500

'

[1]

During the 2012 fiscal year, the Company completed a private exchange offer, resulting in the exchange of $500 million outstanding aggregate principal amount of subordinated debt issued by a subsidiary for the same aggregate principal amount of new senior notes issued by the Parent. A cash premium of $176 million was paid by the subsidiary but is associated with the borrowings on the Parent financial statements.

Parent_Company_Condensed_Finan5

Parent Company Condensed Financial Information (Schedule of Parent Company Condensed Statements of Cash Flows) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Nov. 30, 2012		Nov. 30, 2011
Cash flows from operating activities	'	'	'		'
Net income	$170	$2,470	$2,345		$2,227
Stock-based compensation expense	3	59	47		44
Deferred income taxes	-12	322	146		232
Depreciation and amortization	6	65	63		60
(Increase) decrease in other assets	-68	-252	-112		-22
Net cash provided by operating activities	222	3,517	3,041		3,598
Cash flows from investing activities	'	'	'		'
Net cash (used for) provided by investing activities	409	-3,163	-5,693		-8,110
Cash flows from financing activities	'	'	'		'
Net increase (decrease) in short-term borrowings from subsidiaries	43	-231	234		50
Proceeds from issuance of common stock	2	13	26		23
Proceeds from issuance of preferred stock	0	0	560		0
Purchases of treasury stock	-12	-1,296	-1,216		-436
Net (decrease) increase in deposits	65	2,782	2,539		5,142
Premium paid on debt exchange	0	0	-291		0
Dividends paid on common and preferred stock	-5	-399	-209		-110
Net cash provided by (used for) financing activities	-1,973	3,616	3,728		2,263
Increase (decrease) in cash and cash equivalents	-1,342	3,970	1,076		-2,249
Cash and cash equivalents, at beginning of period	3,926	2,584	2,850		5,099
Cash and cash equivalents, at end of period	2,584	6,554	3,926		2,850
Cash paid during year for interest expense	81	975	1,203		1,342
Cash paid during year for income taxes, net of income tax refunds	-1	1,348	1,301		906
Parent Company [Member]	'	'	'		'
Cash flows from operating activities	'	'	'		'
Net income	170	2,470	2,345		2,227
Equity in undistributed net income of subsidiaries	-173	-919	-759		-875
Stock-based compensation expense	3	59	47		44
Deferred income taxes	-1	-2	109		18
Premium on debt issuance	0	0	-176	[1]	0
Depreciation and amortization	1	19	4		0
(Increase) decrease in other assets	32	-33	-16		-8
Increase (decrease) in other liabilities and accrued expenses	-15	29	10		-16
Net cash provided by operating activities	17	1,623	1,564		1,390
Cash flows from investing activities	'	'	'		'
Increase in investment in subsidiaries	-1	0	-196		-8
(Increase) decrease in loans to subsidiaries	57	-29	-520		-877
Net cash (used for) provided by investing activities	56	-29	-716		-885
Cash flows from financing activities	'	'	'		'
Net increase (decrease) in short-term borrowings from subsidiaries	-6	58	1		0
Proceeds from issuance of common stock	2	13	26		23
Proceeds from issuance of preferred stock	0	0	560		0
Proceeds from advances from subsidiaries	0	0	93		0
Purchases of treasury stock	-12	-1,296	-1,216		-436
Net (decrease) increase in deposits	-12	-7	12		18
Premium paid on debt exchange	0	0	-115		0
Dividends paid on common and preferred stock	-5	-399	-209		-110
Net cash provided by (used for) financing activities	-33	-1,631	-848		-505
Increase (decrease) in cash and cash equivalents	40	-37	0		0
Cash and cash equivalents, at beginning of period	1	41	1		1
Cash and cash equivalents, at end of period	41	4	1		1
Cash paid during year for interest expense	2	65	66		77
Cash paid during year for income taxes, net of income tax refunds	0	-1	-65		11
Capital contribution to subsidiary	0	0	499	[1]	0
Debt issuance, net of discount	0	0	-499	[1]	0
Parent Company [Member] | Senior Notes [Member]	'	'	'		'
Cash flows from financing activities	'	'	'		'
Outstanding aggregate principal amount exchanged	'	'	$500		'
[1]	During the 2012 fiscal year, the Company completed a private exchange offer, resulting in the exchange of $500 million outstanding aggregate principal amount of subordinated debt issued by a subsidiary for the same aggregate principal amount of new senior notes issued by the Parent. A cash premium of $176 million was paid by the subsidiary but is associated with the borrowings on the Parent financial statements.

Transition_Period_Financial_In2

Transition Period Financial Information Transition Period Financial Information (Schedule of Transition Period Financial Information) (Details) (USD $)	1 Months Ended		3 Months Ended																12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Nov. 30, 2012		Aug. 31, 2012		31-May-12		Feb. 29, 2012		Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2010
Transition Period Financial Information [Abstract]	'	'	'		'		'		'		'		'		'		'		'	'	'	'
Net interest income	$492	$442	$1,569		$1,509		$1,430		$1,410		$1,394		$1,370		$1,315		$1,293		$5,918	$5,372	$4,860	'
Provision for loan losses	178	173	354		333		240		159		338		126		232		152		1,086	848	1,013	'
Other income	200	211	'		'		'		'		'		'		'		'		2,306	2,281	2,205	'
Other expense	240	217	838		783		820		753		800		826		749		677		3,194	3,052	2,541	'
Income before income tax expense	274	263	937		946		981		1,080		860		1,012		867		1,014		3,944	3,753	3,511	'
Income tax expense	104	99	335		353		379		407		309		385		330		384		1,474	1,408	1,284	'
Net income	170	164	602		593		602		673		551		627		537		630		2,470	2,345	2,227	'
Net income allocated to common stockholders	168	162	588	[1]	579	[1]	588	[1]	659	[1]	541	[1]	621	[1]	532	[1]	624	[1]	2,414	2,318	2,202	'
Basic earnings per common share (in dollars per share)	$0.34	$0.31	$1.24	[1]	$1.20	[1]	$1.20	[1]	$1.33	[1]	$1.08	[1]	$1.21	[1]	$1.01	[1]	$1.18	[1]	$4.97	$4.47	$4.06	'
Diluted earnings per common share (in dollars per share)	$0.34	$0.30	$1.23	[1]	$1.20	[1]	$1.20	[1]	$1.33	[1]	$1.07	[1]	$1.21	[1]	$1	[1]	$1.18	[1]	$4.96	$4.46	$4.06	'
Weighted average shares outstanding	498	529	'		'		'		'		'		'		'		'		485	519	542	'
Weighted average shares outstanding (fully diluted)	499	530	'		'		'		'		'		'		'		'		487	520	543	'
Total loan receivables	62,598	59,372	65,771		'		'		'		'		'		'		'		65,771	'	'	'
Allowance for loan losses	-1,788	-2,245	-1,648		'		'		'		-1,725		'		'		'		-1,648	-1,725	-2,205	-3,304
Total assets	73,491	69,473	79,340		'		'		'		'		'		'		'		79,340	'	'	'
Long-term borrowings	17,666	18,265	20,474		'		'		'		'		'		'		'		20,474	'	'	'
Total liabilities	63,618	61,115	68,531		'		'		'		'		'		'		'		68,531	'	'	'
Total stockholders' equity	$9,873	$8,358	$10,809		'		'		'		$9,778		'		'		'		$10,809	$9,778	$8,242	$6,457
[1]	Because the inputs to net income allocated to common stockholders and earnings per share are calculated using weighted averages for the quarter, the sum of all four quarters may differ from the year to date amounts in the consolidated statements of income.

Quarterly_Results_Schedule_of_

Quarterly Results (Schedule of Quarterly Results) (Details) (USD $)	1 Months Ended		3 Months Ended																12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Nov. 30, 2012		Aug. 31, 2012		31-May-12		Feb. 29, 2012		Dec. 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Quarterly Financial Data [Abstract]	'	'	'		'		'		'		'		'		'		'		'	'	'
Interest income	$595	'	$1,842		$1,787		$1,727		$1,708		$1,706		$1,695		$1,656		$1,646		$7,064	$6,703	$6,345
Interest expense	103	'	273		278		297		298		312		325		341		353		1,146	1,331	1,485
Net interest income	492	442	1,569		1,509		1,430		1,410		1,394		1,370		1,315		1,293		5,918	5,372	4,860
Provision for loan losses	178	173	354		333		240		159		338		126		232		152		1,086	848	1,013
Gain (loss) on investments	2	'	2		0		0		3		26		0		0		0		5	26	-4
Other income	'	'	558		553		611		579		578		594		533		550		'	'	'
Other expense	240	217	838		783		820		753		800		826		749		677		3,194	3,052	2,541
Income before income tax expense	274	263	937		946		981		1,080		860		1,012		867		1,014		3,944	3,753	3,511
Income tax expense	104	99	335		353		379		407		309		385		330		384		1,474	1,408	1,284
Net income	170	164	602		593		602		673		551		627		537		630		2,470	2,345	2,227
Net income allocated to common stockholders	$168	$162	$588	[1]	$579	[1]	$588	[1]	$659	[1]	$541	[1]	$621	[1]	$532	[1]	$624	[1]	$2,414	$2,318	$2,202
Basic earnings per common share (in dollars per share)	$0.34	$0.31	$1.24	[1]	$1.20	[1]	$1.20	[1]	$1.33	[1]	$1.08	[1]	$1.21	[1]	$1.01	[1]	$1.18	[1]	$4.97	$4.47	$4.06
Diluted earnings per common share (in dollars per share)	$0.34	$0.30	$1.23	[1]	$1.20	[1]	$1.20	[1]	$1.33	[1]	$1.07	[1]	$1.21	[1]	$1	[1]	$1.18	[1]	$4.96	$4.46	$4.06
[1]	Because the inputs to net income allocated to common stockholders and earnings per share are calculated using weighted averages for the quarter, the sum of all four quarters may differ from the year to date amounts in the consolidated statements of income.