| Document and Entity Information | Oct. 29, 2019 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001635718 |
| Document Type | 8-K |
| Document Period End Date | Oct. 29, 2019 |
| Entity Registrant Name | GANNETT CO., INC. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 1-36874 |
| Entity Tax Identification Number | 47-2390983 |
| 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 | 22107-0910 |
| City Area Code | (703) |
| Local Phone Number | 854-6000 |
| Written Communications | true |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, par value $0.01 per share |
| Trading Symbol | GCI |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
