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Allowance for Loan Losses - Receivable for Partially Charged-Off Loans (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Receivables [Abstract]
Allowance for private education loans losses	$ 2,097	$ 2,171	$ 2,200

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- Definition

Amount of allowance to cover probable credit losses on the company's Private Education Loans.

+ References

No definition available.

+ Details

Name:	navi_AllowanceForPrivateEducationLoansLosses
Namespace Prefix:	navi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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- Details

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