| Document and Entity Information | May 12, 2023 |
| Document And Entity Information [Line Items] | |
| Entity Registrant Name | NAVIENT CORP |
| Amendment Flag | false |
| Entity Central Index Key | 0001593538 |
| Document Type | 8-K |
| Document Period End Date | May 12, 2023 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-36228 |
| Entity Tax Identification Number | 46-4054283 |
| Entity Address, Address Line One | 123 Justison Street |
| Entity Address, City or Town | Wilmington |
| Entity Address, State or Province | DE |
| Entity Address, Postal Zip Code | 19801 |
| City Area Code | (302) |
| Local Phone Number | 283-8000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Common Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Common stock, par value $.01 per share |
| Trading Symbol | NAVI |
| Security Exchange Name | NASDAQ |
| Senior Notes [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 6% Senior Notes due December 15, 2043 |
| Trading Symbol | JSM |
| Security Exchange Name | NASDAQ |
| Preferred Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Preferred Stock Purchase Rights |
| Security Exchange Name | NASDAQ |
