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

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_ClassOfStockLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration