Description Of Business, Basis Of Presentation, And Changes In Significant Accounting Policies	3 Months Ended
Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]	Description of Business, Basis of Presentation, and Changes in Significant Accounting Policies Ally Financial Inc. (formerly GMAC Inc. and referred to herein as Ally, we, our, or us) is a leading, independent, diversified, financial services firm. Founded in 1919, we are a leading automotive financial services company with over 90 years of experience, providing a broad array of financial products and services to automotive dealers and their customers. We operate as a financial holding company and a bank holding company. Our banking subsidiary, Ally Bank, is an indirect wholly owned subsidiary of Ally Financial Inc. and a leading franchise in the growing direct (internet, telephone, mobile, and mail) banking market. Our accounting and reporting policies conform to accounting principles generally accepted in the United States of America (GAAP). Additionally, where applicable, the policies conform to the accounting and reporting guidelines prescribed by bank regulatory authorities. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and that affect income and expenses during the reporting period. In developing the estimates and assumptions, management uses all available evidence; however, actual results could differ. The Condensed Consolidated Financial Statements at March 31, 2014, and for the three months ended March 31, 2014, and 2013, are unaudited but reflect all adjustments that are, in management’s opinion, necessary for the fair presentation of the results for the interim periods presented. All such adjustments are of a normal recurring nature. These unaudited Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements (and the related notes) included in our Annual Report on Form 10-K for the year ended December 31, 2013, as filed on March 3, 2014, with the U.S. Securities and Exchange Commission (SEC). Initial Public Offering of Common Stock, Stock Split, and Changes in Number of Shares Authorized In April 2014, we completed an initial public offering (IPO) of 95 million shares of common stock at $25 per share. Proceeds from the offering amounted to $2.4 billion, which were obtained by the U.S. Department of the Treasury (Treasury) as the single selling stockholder. In connection with the IPO, we effected a 310-for-one stock split on shares of our common stock, $0.01 par value per share. Accordingly, all references in the Condensed Consolidated Financial Statements to share and per share amounts relating to common stock have been adjusted, on a retroactive basis, to recognize the 310-for-one stock split. In addition, on April 9, 2014, we increased the number of shares authorized for issuance of common stock to 1.1 billion and decreased the number of shares authorized for issuance of Series A Preferred Stock to approximately 41 million. The changes in the number of shares authorized will be reflected in the Condensed Consolidated Financial Statements in future reporting periods. Significant Accounting Policies Income Taxes In calculating the provision for interim income taxes, in accordance with Accounting Standards Codification (ASC) 740, Income Taxes, we apply an estimated annual effective tax rate to year-to-date ordinary income. At the end of each interim period, we estimate the effective tax rate expected to be applicable for the full fiscal year. This method differs from that described in Note 1 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K, which describes our annual significant income tax accounting policy and related methodology. Recently Adopted Accounting Standards Liabilities — Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation Is Fixed at the Reporting Date (ASU 2013-04) As of January 1, 2014, we adopted ASU 2013-04. The guidance within the ASU requires an entity to measure obligations resulting from joint and several liability arrangements for which the total amount of the obligation within the scope of this guidance is fixed at the reporting date, as the sum of the following: (a) The amount the reporting entity agreed to pay on the basis of its arrangement among its co-obligors and (b) any additional amount the reporting entity expects to pay on behalf of its co-obligors. The amendments were effective retrospectively for all arrangements within its scope. It further requires an entity to disclose the nature and amount of the obligation as well as other information about those obligations. The adoption of this guidance did not have a material effect on our consolidated financial condition or results of operations. Foreign Currency Matters — Parent's Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity (ASU 2013-05) As of January 1, 2014, we adopted ASU 2013-05. The guidance within the ASU closes diversity in practice in this area and requires a reporting entity that ceases to have a controlling financial interest, in a subsidiary or group of assets or a business, within a foreign entity to release any related Cumulative Translation Adjustment (CTA) into net income. The CTA should be released into net income only if the sale or transfer results in the complete or substantially complete liquidation of the foreign entity. For an equity method investment that is a foreign entity, a pro rata portion of the CTA should be released into net income upon a partial sale of such an investment. This ASU further clarifies that the sale of an investment in a foreign entity includes both events that result in the loss of a controlling financial interest in a foreign entity, irrespective of any retained investment, and events that result in step acquisition under which an acquirer obtains control of an acquiree in which it held an equity interest immediately before the acquisition date. Under these circumstances, the CTA should be released into net income upon their occurrence. The amendments are to be applied prospectively for all transactions within its scope. Since the guidance is prospective and we have previously sold or exited substantially all of our international businesses and released the related CTA upon those dispositions, the implementation will not have a material effect on our consolidated financial condition or results of operations. Income Taxes — Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (ASU 2013-11) As of January 1, 2014, we adopted ASU 2013-11. The guidance within the ASU closes diversity in practice and requires an unrecognized tax benefit, or a portion of an unrecognized tax benefit, to be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. The guidance further includes an exception that if a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available to settle any additional income taxes that would result from the disallowance of a tax position at the reporting date or the tax law of the applicable jurisdiction does not require the entity to use them and the entity does not intend to use them, the unrecognized tax benefit for such purpose should be presented in the financial statements as a liability and should not be combined with deferred tax assets. The assessment of whether a deferred tax asset is available is based on the unrecognized tax benefit and deferred tax asset that exist at the reporting date and should be made presuming disallowance of the tax position at the reporting date. The amendments are to be applied prospectively to all unrecognized tax benefits that exist at the effective date. The adoption of this guidance did not have a material effect to our consolidated financial condition or results of operations. Investments — Accounting for Investments in Qualified Affordable Housing Projects (ASU 2014-01) As of January 1, 2014, we adopted ASU 2014-01. The amendments in this ASU allow an entity to make an accounting policy election to account for investments in qualified affordable housing projects using a proportional amortization method, if certain conditions are met. Under the election, the entity would amortize the initial cost of the investment in proportion to the tax credits and other benefits received while recognizing the net investment performance in the statement of comprehensive income as a component of income tax expense. The amendments are to be applied retrospectively to all periods presented. We have elected to utilize the proportional amortization method for qualifying affordable housing investments and therefore will be presenting the amortization and tax impacts of such investments as a component income tax expense under the proportional amortization method. The adoption of this guidance did not have a material effect to our consolidated financial condition or results of operations. Recently Issued Accounting Standards Receivables — Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure (ASU 2014-04) In January 2014, the FASB issued ASU 2014-04. The amendments in this ASU clarify the timing for which an entity should reclassify a loan that has been foreclosed or where an in substance repossession has occurred to real estate owned. The guidance requires such reclassification to occur when the entity obtains legal title upon completion of foreclosure or the borrower conveys all interest in the residential real estate property to the entity to satisfy the loan through completion of a deed in lieu of foreclosure or similar legal agreement. In addition, the ASU clarifies that redemption rights of the borrower should be ignored for purposes of determining whether legal title has transferred. The amendments are effective for us beginning on January 1, 2015. The amendments can be applied using either a modified retrospective or prospective basis. Under the modified retrospective approach, the entity should record a cumulative-effect adjustment to residential consumer mortgage loans and residential real estate owned as of the beginning of the annual period for which the amendments are effective. Early adoption is permitted. Management is assessing the impact of the adoption of this guidance.

Description of Business, Basis of Presentation, and Changes in Significant Accounting Policies

Ally Financial Inc. (formerly GMAC Inc. and referred to herein as Ally, we, our, or us) is a leading, independent, diversified, financial services firm. Founded in 1919, we are a leading automotive financial services company with over 90 years of experience, providing a broad array of financial products and services to automotive dealers and their customers. We operate as a financial holding company and a bank holding company. Our banking subsidiary, Ally Bank, is an indirect wholly owned subsidiary of Ally Financial Inc. and a leading franchise in the growing direct (internet, telephone, mobile, and mail) banking market.

Our accounting and reporting policies conform to accounting principles generally accepted in the United States of America (GAAP). Additionally, where applicable, the policies conform to the accounting and reporting guidelines prescribed by bank regulatory authorities. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and that affect income and expenses during the reporting period. In developing the estimates and assumptions, management uses all available evidence; however, actual results could differ.

The Condensed Consolidated Financial Statements at March 31, 2014, and for the three months ended March 31, 2014, and 2013, are unaudited but reflect all adjustments that are, in management’s opinion, necessary for the fair presentation of the results for the interim periods presented. All such adjustments are of a normal recurring nature. These unaudited Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements (and the related notes) included in our Annual Report on Form 10-K for the year ended December 31, 2013, as filed on March 3, 2014, with the U.S. Securities and Exchange Commission (SEC).

Initial Public Offering of Common Stock, Stock Split, and Changes in Number of Shares Authorized

In April 2014, we completed an initial public offering (IPO) of 95 million shares of common stock at $25 per share. Proceeds from the offering amounted to $2.4 billion, which were obtained by the U.S. Department of the Treasury (Treasury) as the single selling stockholder. In connection with the IPO, we effected a 310-for-one stock split on shares of our common stock, $0.01 par value per share. Accordingly, all references in the Condensed Consolidated Financial Statements to share and per share amounts relating to common stock have been adjusted, on a retroactive basis, to recognize the 310-for-one stock split. In addition, on April 9, 2014, we increased the number of shares authorized for issuance of common stock to 1.1 billion and decreased the number of shares authorized for issuance of Series A Preferred Stock to approximately 41 million. The changes in the number of shares authorized will be reflected in the Condensed Consolidated Financial Statements in future reporting periods.

Significant Accounting Policies

Income Taxes

In calculating the provision for interim income taxes, in accordance with Accounting Standards Codification (ASC) 740, Income Taxes, we apply an estimated annual effective tax rate to year-to-date ordinary income. At the end of each interim period, we estimate the effective tax rate expected to be applicable for the full fiscal year. This method differs from that described in Note 1 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K, which describes our annual significant income tax accounting policy and related methodology.

Recently Adopted Accounting Standards

Liabilities — Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation Is Fixed at the Reporting Date (ASU 2013-04)

As of January 1, 2014, we adopted ASU 2013-04. The guidance within the ASU requires an entity to measure obligations resulting from joint and several liability arrangements for which the total amount of the obligation within the scope of this guidance is fixed at the reporting date, as the sum of the following: (a) The amount the reporting entity agreed to pay on the basis of its arrangement among its co-obligors and (b) any additional amount the reporting entity expects to pay on behalf of its co-obligors. The amendments were effective retrospectively for all arrangements within its scope. It further requires an entity to disclose the nature and amount of the obligation as well as other information about those obligations. The adoption of this guidance did not have a material effect on our consolidated financial condition or results of operations.

Foreign Currency Matters — Parent's Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity (ASU 2013-05)

As of January 1, 2014, we adopted ASU 2013-05. The guidance within the ASU closes diversity in practice in this area and requires a reporting entity that ceases to have a controlling financial interest, in a subsidiary or group of assets or a business, within a foreign entity to release any related Cumulative Translation Adjustment (CTA) into net income. The CTA should be released into net income only if the sale or transfer results in the complete or substantially complete liquidation of the foreign entity. For an equity method investment that is a foreign entity, a pro rata portion of the CTA should be released into net income upon a partial sale of such an investment. This ASU further clarifies that the sale of an investment in a foreign entity includes both events that result in the loss of a controlling financial interest in a foreign entity, irrespective of any retained investment, and events that result in step acquisition under which an acquirer obtains control of an acquiree in which it held an equity interest immediately before the acquisition date. Under these circumstances, the CTA should be released into net income upon their occurrence. The amendments are to be applied prospectively for all transactions within its scope. Since the guidance is prospective and we have previously sold or exited substantially all of our international businesses and released the related CTA upon those dispositions, the implementation will not have a material effect on our consolidated financial condition or results of operations.

Income Taxes — Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (ASU 2013-11)

As of January 1, 2014, we adopted ASU 2013-11. The guidance within the ASU closes diversity in practice and requires an unrecognized tax benefit, or a portion of an unrecognized tax benefit, to be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. The guidance further includes an exception that if a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available to settle any additional income taxes that would result from the disallowance of a tax position at the reporting date or the tax law of the applicable jurisdiction does not require the entity to use them and the entity does not intend to use them, the unrecognized tax benefit for such purpose should be presented in the financial statements as a liability and should not be combined with deferred tax assets. The assessment of whether a deferred tax asset is available is based on the unrecognized tax benefit and deferred tax asset that exist at the reporting date and should be made presuming disallowance of the tax position at the reporting date. The amendments are to be applied prospectively to all unrecognized tax benefits that exist at the effective date. The adoption of this guidance did not have a material effect to our consolidated financial condition or results of operations.

Investments — Accounting for Investments in Qualified Affordable Housing Projects (ASU 2014-01)

As of January 1, 2014, we adopted ASU 2014-01. The amendments in this ASU allow an entity to make an accounting policy election to account for investments in qualified affordable housing projects using a proportional amortization method, if certain conditions are met. Under the election, the entity would amortize the initial cost of the investment in proportion to the tax credits and other benefits received while recognizing the net investment performance in the statement of comprehensive income as a component of income tax expense. The amendments are to be applied retrospectively to all periods presented. We have elected to utilize the proportional amortization method for qualifying affordable housing investments and therefore will be presenting the amortization and tax impacts of such investments as a component income tax expense under the proportional amortization method. The adoption of this guidance did not have a material effect to our consolidated financial condition or results of operations.

Recently Issued Accounting Standards

Receivables — Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure (ASU 2014-04)

In January 2014, the FASB issued ASU 2014-04. The amendments in this ASU clarify the timing for which an entity should reclassify a loan that has been foreclosed or where an in substance repossession has occurred to real estate owned. The guidance requires such reclassification to occur when the entity obtains legal title upon completion of foreclosure or the borrower conveys all interest in the residential real estate property to the entity to satisfy the loan through completion of a deed in lieu of foreclosure or similar legal agreement. In addition, the ASU clarifies that redemption rights of the borrower should be ignored for purposes of determining whether legal title has transferred. The amendments are effective for us beginning on January 1, 2015. The amendments can be applied using either a modified retrospective or prospective basis. Under the modified retrospective approach, the entity should record a cumulative-effect adjustment to residential consumer mortgage loans and residential real estate owned as of the beginning of the annual period for which the amendments are effective. Early adoption is permitted. Management is assessing the impact of the adoption of this guidance.