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Stockholders' Equity - Additional Detail (Details) - USD ($) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014
Class of Stock [Line Items] |  |  |  |
Total net transfers from the entity that is now a subsidiary of Navient | $ 0 | $ 462,165,000 | $ 0 | $ 479,409,000
Common Stock |  |  |  |
Class of Stock [Line Items] |  |  |  |
Common stock closing price (usd per share) | $ 9.87 |  | $ 9.87 |

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