Significant Accounting Policies	6 Months Ended
Jun. 30, 2018
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Basis of Presentation The accompanying unaudited, consolidated financial statements of SLM Corporation (“Sallie Mae,” “SLM,” the “Company,” “we,” or “us”) have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information. Accordingly, they do not include all the information and footnotes required by GAAP for complete consolidated financial statements. The consolidated financial statements include the accounts of SLM Corporation and its majority-owned and controlled subsidiaries after eliminating the effects of intercompany accounts and transactions. In the opinion of management, all adjustments considered necessary for a fair statement of the results for the interim periods have been included. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Operating results for the three and six months ended June 30, 2018 are not necessarily indicative of the results for the year ending December 31, 2018 or for any other period. These unaudited financial statements should be read in conjunction with the audited financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2017 (the “2017 Form 10-K”). Consolidation The consolidated financial statements include the accounts of the Company and its majority-owned and controlled subsidiaries after eliminating the effects of intercompany accounts and transactions. We consolidate any variable interest entity (“VIE”) where we have determined we are the primary beneficiary. The primary beneficiary is the entity which has both: (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses or receive benefits of the entity that could potentially be significant to the VIE. Recently Issued and Adopted Accounting Pronouncements In November 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash.” Whereas restricted cash balances have traditionally been excluded from the statement of cash flows, this ASU requires restricted cash and restricted cash equivalents to be included within the beginning and ending totals of cash, cash equivalents and restricted cash presented on the statement of cash flows for all periods presented. Restricted cash and restricted cash equivalent inflows and outflows with external parties are required to be classified within the operating, investing, and/or financing activity sections of the statement of cash flows, whereas transfers between cash and cash equivalents and restricted cash and restricted cash equivalents should no longer be presented on the statement of cash flows. ASU No. 2016-18 also requires (a) the nature of the restrictions to be disclosed to help provide information about the sources and uses of these balances during a reporting period and (b) a reconciliation of the cash, cash equivalents and restricted cash totals on the statement of cash flows to the related balance sheet line items when cash, cash equivalents, and restricted cash are presented in more than one line item on the balance sheet. The reconciliation can be presented either on the face of the statement of cash flows or in the notes to the financial statements and must be provided for each period that a balance sheet is presented. We adopted the new accounting pronouncement on January 1, 2018, and the adoption did not have a material impact to our statement of cash flows. In February 2018, the FASB issued ASU No. 2018-02, “Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income,” which allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the tax law and tax rate changes under the Tax Cuts and Jobs Act of 2017 (the “Tax Act”) enacted on December 22, 2017. Under the Tax Act, deferred taxes were adjusted to reflect the reduction of the historical corporate income tax rate to the newly enacted corporate income tax rate, which left the tax effects on items within accumulated other comprehensive income stranded at an inappropriate tax rate. This guidance is effective for fiscal years beginning after December 15, 2018, and for interim periods within those fiscal years, with early adoption permitted. We adopted this standard effective January 1, 2018 and recorded a $0.6 million reclass from accumulated other comprehensive income to retained earnings in the first quarter of 2018.

Significant Accounting Policies

Basis of Presentation

The accompanying unaudited, consolidated financial statements of SLM Corporation (“Sallie Mae,” “SLM,” the “Company,” “we,” or “us”) have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information. Accordingly, they do not include all the information and footnotes required by GAAP for complete consolidated financial statements. The consolidated financial statements include the accounts of SLM Corporation and its majority-owned and controlled subsidiaries after eliminating the effects of intercompany accounts and transactions. In the opinion of management, all adjustments considered necessary for a fair statement of the results for the interim periods have been included. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Operating results for the three and six months ended June 30, 2018 are not necessarily indicative of the results for the year ending December 31, 2018 or for any other period. These unaudited financial statements should be read in conjunction with the audited financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2017 (the “2017 Form 10-K”).

Consolidation

The consolidated financial statements include the accounts of the Company and its majority-owned and controlled subsidiaries after eliminating the effects of intercompany accounts and transactions.

We consolidate any variable interest entity (“VIE”) where we have determined we are the primary beneficiary. The primary beneficiary is the entity which has both: (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses or receive benefits of the entity that could potentially be significant to the VIE.

Recently Issued and Adopted Accounting Pronouncements

In November 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash.” Whereas restricted cash balances have traditionally been excluded from the statement of cash flows, this ASU requires restricted cash and restricted cash equivalents to be included within the beginning and ending totals of cash, cash equivalents and restricted cash presented on the statement of cash flows for all periods presented. Restricted cash and restricted cash equivalent inflows and outflows with external parties are required to be classified within the operating, investing, and/or financing activity sections of the statement of cash flows, whereas transfers between cash and cash equivalents and restricted cash and restricted cash equivalents should no longer be presented on the statement of cash flows. ASU No. 2016-18 also requires (a) the nature of the restrictions to be disclosed to help provide information about the sources and uses of these balances during a reporting period and (b) a reconciliation of the cash, cash equivalents and restricted cash totals on the statement of cash flows to the related balance sheet line items when cash, cash equivalents, and restricted cash are presented in more than one line item on the balance sheet. The reconciliation can be presented either on the face of the statement of cash flows or in the notes to the financial statements and must be provided for each period that a balance sheet is presented. We adopted the new accounting pronouncement on January 1, 2018, and the adoption did not have a material impact to our statement of cash flows.

In February 2018, the FASB issued ASU No. 2018-02, “Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income,” which allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the tax law and tax rate changes under the Tax Cuts and Jobs Act of 2017 (the “Tax Act”) enacted on December 22, 2017. Under the Tax Act, deferred taxes were adjusted to reflect the reduction of the historical corporate income tax rate to the newly enacted corporate income tax rate, which left the tax effects on items within accumulated other comprehensive income stranded at an inappropriate tax rate. This guidance is effective for fiscal years beginning after December 15, 2018, and for interim periods within those fiscal years, with early adoption permitted. We adopted this standard effective January 1, 2018 and recorded a $0.6 million reclass from accumulated other comprehensive income to retained earnings in the first quarter of 2018.