| Cover Document | Aug. 05, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Aug. 5, 2021 |
| Entity Registrant Name | IRON MOUNTAIN INC |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 1-13045 |
| Entity Tax Identification Number | 23-2588479 |
| Entity Address, Address Line One | One Federal Street |
| Entity Address, City or Town | Boston |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 2110 |
| City Area Code | 617 |
| Local Phone Number | 535-4766 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $.01 par value per share |
| Trading Symbol | IRM |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001020569 |
| Amendment Flag | false |
