| Document and Entity Information | Jan. 03, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jan. 3, 2020 |
| Current Fiscal Year End Date | --12-31 |
| Entity Registrant Name | GANNETT CO., INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-36097 |
| Entity Tax Identification Number | 38-3910250 |
| Entity Address, Address Line One | 7950 Jones Branch Drive |
| Entity Address, City or Town | McLean |
| Entity Address, State or Province | VA |
| Entity Address, Postal Zip Code | 22107 |
| City Area Code | 0910 |
| Local Phone Number | 703-854-6000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001579684 |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | GCI |
| Security Exchange Name | NYSE |
