Significant Accounting Policies (Policies)	9 Months Ended
Significant Accounting Policies (Policies)	Sep. 30, 2012
Accounting Policies [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	NOTE 1 – SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The unaudited consolidated financial statements have been prepared in accordance with U.S. GAAP for interim financial information. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete consolidated financial statements. In the opinion of management, all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair presentation of the results of operations in these financial statements, have been made. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could vary from these estimates. Certain reclassifications have been made to prior period amounts to conform to the current period presentation. The Company evaluated subsequent events through the date its financial statements were issued. These financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2011. During the three months ended September 30, 2012, the Company elected to revise its credit policy related to the nonaccrual status and timing of charge-off recognition of second lien loans. The Company began classifying second lien loans as nonaccrual when the first lien loan is classified as nonaccrual, even if the second lien loan is performing, and as a result, the Company reclassified $81 million of performing second lien loans to nonaccrual. Additionally, the Company previously charged-off second lien loans at 180 days past due, but implemented a change in policy in the third quarter of 2012 to recognize the charge-off at 120 days past due as the analysis indicated that when a second lien loan becomes 120 days past due, the vast majority of these loans ultimately experience a charge-off. The change in credit policy resulted in $65 million of incremental charge-offs during the three and nine months ended September 30, 2012. Except for accounting policies that have been recently adopted as described below, and the policy change related to second lien loans noted above, there have been no significant changes to the Company’s accounting policies as disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2011.
Accounting Policies Recently Adopted and Pending Accounting Pronouncements	Accounting Policies Recently Adopted and Pending Accounting Pronouncements In May 2011, the FASB issued ASU 2011-04, “Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRSs.” The primary purpose of the ASU was to conform the language in the fair value measurements guidance in U.S. GAAP and IFRS. The ASU also clarified how to apply existing fair value measurement and disclosure requirements. Further, the ASU required additional disclosures about transfers between level 1 and 2 of the fair value hierarchy, quantitative information for level 3 inputs, and the level of the fair value measurement hierarchy for items that are not measured at fair value in the statement of financial position but for which the fair value is required to be disclosed. The ASU was effective for the interim reporting period ending March 31, 2012. The Company adopted the standard as of January 1, 2012, and the required disclosures are included in Note 12, “Fair Value Election and Measurement.” The adoption did not impact the Company’s financial position, results of operations, or EPS. In June 2011, the FASB issued ASU 2011-05, “Comprehensive Income (Topic 220): Presentation of Comprehensive Income.” The ASU requires presentation of the components of comprehensive income in either a continuous statement of comprehensive income or two separate but consecutive statements. The update does not change the items presented in OCI and does not affect the calculation or reporting of EPS. In December 2011, the FASB issued ASU 2011-12, “Comprehensive Income (Topic 220): Deferral of the Effective Date for Amendments to the Presentation of Reclassification of Items out of Accumulated Other Comprehensive Income in ASU 2011-05,” which deferred the effective date for the amendments to the reclassification of items out of AOCI. In June 2012, the FASB decided that the presentation requirements deferred in ASU 2011-12 would not be reinstated. The guidance, with the exception of reclassification adjustments, was effective on January 1, 2012, and must be applied retrospectively for all periods presented. The Company adopted the standard as of January 1, 2012, and the required disclosures are included in the Consolidated Statements of Comprehensive (Loss)/Income. The adoption did not impact the Company’s financial position, results of operations, or EPS. In September 2011, the FASB issued ASU 2011-08, “Intangibles-Goodwill and Other (Topic 350): Testing Goodwill for Impairment.” The ASU amends interim and annual goodwill impairment testing requirements such that an entity is not required to calculate the fair value of a reporting unit unless the entity determines that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. The guidance was effective for annual and interim goodwill impairment tests beginning on or after January 1, 2012. The Company adopted the standard as of January 1, 2012. The adoption did not have an impact on the Company's financial position, results of operations, or EPS. In July 2012, the FASB issued ASU 2012-02, “Intangibles-Goodwill and Other (Topic 350): Testing Indefinite-Lived Intangible Assets for Impairment." The ASU permits entities to perform an optional qualitative assessment for determining whether it is more likely than not that an indefinite-lived intangible asset is impaired. The guidance is effective for annual and interim impairment tests performed for fiscal years beginning after September 15, 2012. The Company has evaluated this ASU and it is not expected to impact the Company's financial position, results of operations, or EPS when adopted. In October 2012, the FASB issued ASU 2012-04, “Technical Corrections and Improvements." The ASU prescribes technical corrections and improvements to the Accounting Standards Codification for source literature amendments, guidance clarification and reference corrections, and relocated guidance within the Accounting Standards Codification. The ASU is effective for fiscal periods beginning after December 15, 2012. The Company is evaluating the impact of the ASU; however, it is not expected to have a significant impact on the Company's financial position, results of operations, or EPS.
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	The Company sponsors various short-term incentive and LTI plans for eligible employees. The Company delivers LTIs through various incentive programs, including stock options, RSUs, restricted stock, and LTI cash. Awards under the LTI cash plan generally cliff vest over a period of three years from the date of the award and are paid in cash. AIP is the Company's short-term cash incentive plan for key employees that provides for potential annual cash awards based on the Company's performance and/or the achievement of business unit and individual performance objectives. For the three and nine months ended September 30, 2012, the Company's AIP plan includes a higher number of eligible employees that previously received compensation under other incentive plans. Compensation expense for the AIP and LTI cash plans was $39 million and $32 million for the three months ended September 30, 2012 and 2011, respectively, and $116 million and $92 million for the nine months ended September 30, 2012 and 2011, respectively. Previously, TARP prohibited the payment of any bonus, incentive compensation or stock option award to the Company's five NEOs and certain other highly-compensated executives. As a result, beginning in January 2010, the Company paid additional base salary amounts in the form of stock (salary shares) to the NEOs and some of the other employees who were among the next 20 most highly-compensated employees. The Company did this each pay period in the form of stock units under the SunTrust Banks, Inc. 2009 Stock Plan (the "2009 Stock Plan") until the Company repaid TARP. The Company settled the stock units in cash; for the 2010 salary shares, one half was settled on March 31, 2011, and one half was settled on March 31, 2012. The 2011 salary shares were settled on March 30, 2011, the date the Company repaid the U.S. government's TARP investment. The amount paid upon settlement of the stock units was equal to the value of a share of SunTrust common stock on the settlement date. The value of salary shares paid was $4 million and $7 million in 2012 and 2011, respectively. Stock-Based Compensation The Company provides stock-based awards through the SunTrust Banks, Inc. 2009 Stock Plan (as amended and restated effective January 1, 2011) under which the Compensation Committee of the Board of Directors has the authority to grant stock options, restricted stock, and RSUs to key employees of the Company, of which some awards may have performance or other conditions such as vesting tied to the Company's total shareholder return relative to a peer group or vesting tied to the achievement of a ROA target. The Company granted 1,687,968 shares of restricted stock and 1,690,515 RSUs during the first nine months of 2012. The weighted average grant-date fair value of these awards was $21.84 and $20.77 per share, respectively. The Company also granted 859,390 shares of stock options with a weighted average exercise price of $21.92 during the nine months ended September 30, 2012. During the first nine months of 2011, the Company granted 1,375,406 shares of restricted stock and 344,590 RSUs. The weighted average grant-date fair value of these awards was $31.44 and $37.57 per share, respectively. The Company also granted 813,265 shares of stock options with a weighted average exercise price of $29.70 during the nine months ended September 30, 2011.The fair value of stock options granted during the first nine months of 2012 and 2011 was $7.83 and $10.51 per share, respectively. The fair value of each option grant was estimated on the date of grant using the Black-Scholes option pricing model using the following assumptions:
Loans and Leases Receivable, Nonaccrual Loan and Lease Status, Policy [Policy Text Block]	During the three months ended September 30, 2012, the Company elected to revise its credit policy related to the nonaccrual status and timing of charge-off recognition of second lien loans. The Company began classifying second lien loans as nonaccrual when the first lien loan is classified as nonaccrual, even if the second lien loan is performing, and as a result, the Company reclassified $81 million of performing second lien loans to nonaccrual. Additionally, the Company previously charged-off second lien loans at 180 days past due, but implemented a change in policy in the third quarter of 2012 to recognize the charge-off at 120 days past due as the analysis indicated that when a second lien loan becomes 120 days past due, the vast majority of these loans ultimately experience a charge-off. The change in credit policy resulted in $65 million of incremental charge-offs during the three and nine months ended September 30, 2012.

Disclosure of accounting policy for when a loan ceases to accrue interest or other revenue because the borrower is in financial difficulty. May also describe the treatment of previously earned but uncollected interest income on loans in nonaccrual status, how cash received from borrowers is recorded on loans that are in nonaccrual status, and the policy for resuming accrual of interest. Also includes the policy for charging off uncollectible loans and trade receivables, and the policy for determining past-due or delinquency status (i.e. whether past-due status is based on how recently payments have been received or on contractual terms).

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Disclosure of accounting policy for stock option and stock incentive plans. This disclosure may include (1) the types of stock option or incentive plans sponsored by the entity (2) the groups that participate in (or are covered by) each plan (3) significant plan provisions and (4) how stock compensation is measured, and the methodologies and significant assumptions used to determine that measurement.

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