| Document and Entity Information | Oct. 28, 2021 |
| Cover [Abstract] | |
| Entity Registrant Name | MEDICAL PROPERTIES TRUST INC |
| Amendment Flag | false |
| Entity Central Index Key | 0001287865 |
| Document Type | 8-K |
| Document Period End Date | Oct. 28, 2021 |
| Entity File Number | 001-32559 |
| Entity Incorporation State Country Code | MD |
| Entity Tax Identification Number | 20-0191742 |
| Entity Address, Address Line One | 1000 Urban Center Drive |
| Entity Address, Address Line Two | Suite 501 |
| Entity Address, City or Town | Birmingham |
| Entity Address, State or Province | AL |
| Entity Address, Postal Zip Code | 35242 |
| City Area Code | (205) |
| Local Phone Number | 969-3755 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, par value $0.001 per share, of Medical Properties Trust, Inc. |
| Trading Symbol | MPW |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
