| Document and Entity Information | May 15, 2020 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001502034 |
| Document Type | 8-K |
| Document Period End Date | May 15, 2020 |
| Entity Registrant Name | GNC HOLDINGS, INC. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-35113 |
| Entity Tax Identification Number | 20-8536244 |
| Entity Address, Address Line One | 300 Sixth Avenue |
| Entity Address, City or Town | Pittsburgh |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 15222 |
| City Area Code | (412) |
| Local Phone Number | 288-4600 |
| Security 12b Title | Class A common stock, par value $0.001 per share |
| Trading Symbol | GNC |
| Security Exchange Name | NYSE |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
