Basis of presentation (Policies)	9 Months Ended
Basis of presentation (Policies)	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of presentation policy	The accounting and financial reporting policies of JPMorgan Chase and its subsidiaries conform to accounting principles generally accepted in the U.S. (“U.S. GAAP”). Additionally, where applicable, the policies conform to the accounting and reporting guidelines prescribed by regulatory authorities.
Use of estimates in the preparation of consolidated financial statements policy	The unaudited Consolidated Financial Statements prepared in conformity with U.S. GAAP require management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue and expense, and the disclosures of contingent assets and liabilities. Actual results could be different from these estimates. In the opinion of management, all normal, recurring adjustments have been included for a fair statement of this interim financial information.
Reclassifications policy	Certain amounts reported in prior periods have been reclassified to conform with the current presentation.
New accounting guidance	Effective January 1, 2015, the Firm adopted new accounting guidance for investments in affordable housing projects that qualify for the low-income housing tax credit, which impacted the Corporate & Investment Bank (“CIB”). As a result of the adoption of this new guidance, the Firm made an accounting policy election to amortize the initial cost of its qualifying investments in proportion to the tax credits and other benefits received, and to present the amortization as a component of income tax expense; previously such amounts were predominantly presented in other income. The guidance was required to be applied retrospectively and accordingly, certain prior period amounts have been revised to conform with the current period presentation. The cumulative effect on retained earnings was a reduction of $321 million as of January 1, 2014. The adoption of this accounting guidance resulted in an increase of $223 million and $230 million in other income and income tax expense, respectively, for the three months ended September 30, 2014, and $669 million and $686 million, respectively, for the nine months ended September 30, 2014, which led to an increase of approximately 2% in the effective tax rate for both the three and nine months ended September 30, 2014. The impact on net income and earnings per share in the periods affected was not material. The Firm recognized $398 million and $394 million of tax credits and other tax benefits associated with these investments within Income tax expense for the three months ended September 30, 2015 and 2014, respectively, and $1.2 billion for both the nine months ended September 30, 2015 and 2014. The amount of amortization of such investments reported in income tax expense under the current period presentation was $274 million and $268 million, for the three months ended September 30, 2015 and 2014, respectively, and $829 million and $799 million for the nine months ended September 30, 2015 and 2014, respectively. The carrying value of investments in affordable housing projects was $7.3 billion at both September 30, 2015 and December 31, 2014. These investments are reported in other assets on the Firm’s Consolidated balance sheets. The amount of commitments related to these investments was $1.9 billion and $1.8 billion at September 30, 2015, and December 31, 2014, respectively. These commitments are reported in accounts payable and other liabilities on the Firm’s Consolidated balance sheets.
Offsetting assets and liabilities policy	U.S. GAAP permits entities to present derivative receivables and derivative payables with the same counterparty and the related cash collateral receivables and payables on a net basis on the balance sheet when a legally enforceable master netting agreement exists. U.S. GAAP also permits securities sold and purchased under repurchase agreements to be presented net when specified conditions are met, including the existence of a legally enforceable master netting agreement. The Firm has elected to net such balances when the specified conditions are met. For further information on offsetting assets and liabilities, see Note 1 of JPMorgan Chase’s 2014 Annual Report.
Derivatives executed in contemplation of a sale of the underlying financial asset	In certain instances the Firm enters into transactions where it transfers financial assets but maintains the economic exposure to the transferred assets by entering into a derivative with the same counterparty in contemplation of the initial transfer. The Firm generally accounts for such transfers as collateralized financing transactions as described in Note 12, but in limited circumstances they may qualify to be accounted for as a sale and a derivative under U.S. GAAP. The amount of such transfers accounted for as a sale where the associated derivative was outstanding at September 30, 2015 was not material.
Securities policy	Securities are classified as trading, AFS or held-to-maturity (“HTM”). Securities classified as trading assets are discussed in Note 3.
Transfers and Servicing of Financial Assets Policy	In addition to the Firm’s obligation to repurchase certain loans due to material breaches of representations and warranties as discussed in Note 21, the Firm also has the option to repurchase delinquent loans that it services for Ginnie Mae loan pools, as well as for other U.S. government agencies under certain arrangements. The Firm typically elects to repurchase delinquent loans from Ginnie Mae loan pools as it continues to service them and/or manage the foreclosure process in accordance with the applicable requirements, and such loans continue to be insured or guaranteed. When the Firm’s repurchase option becomes exercisable, such loans must be reported on the Consolidated balance sheets as a loan with a corresponding liability. As of September 30, 2015, and December 31, 2014, the Firm had recorded on its Consolidated balance sheets $11.3 billion and $12.4 billion, respectively, of loans that either had been repurchased or for which the Firm had an option to repurchase. Predominantly all of these amounts relate to loans that have been repurchased from Ginnie Mae loan pools. Additionally, real estate owned resulting from voluntary repurchases of loans was $327 million and $464 million as of September 30, 2015, and December 31, 2014, respectively. Substantially all of these loans and real estate owned are insured or guaranteed by U.S. government agencies. For additional information, refer to Note 13 of this Form 10-Q and Note 14 of JPMorgan Chase’s 2014 Annual Report.

Disclosure of accounting policy for transfers and servicing financial assets, including securitization transactions as well as repurchase and resale agreements. This disclosure may include how the entity (1) determines whether a transaction is accounted for as a sale; (2) accounts for a sale transaction, including the initial and subsequent accounting for any interests that the entity obtains or continues to hold in the transaction, how such interests are valued, and the significant assumptions used in the valuation; (3) accounts for a transaction that does not qualify for sale treatment (that is, a financing); and (4) accounts for its servicing assets and liabilities ("servicing"), including how such servicing is measured initially and subsequently, and the methodology and significant assumptions used to value such servicing.