Related Person Transactions - Narrative (Details)	Sep. 30, 2023
SEVN
Related Party Transaction [Line Items]
Equity interest percentage	13.40%
DHC
Related Party Transaction [Line Items]
Equity interest percentage	9.80%
ILPT | Related Party | Adam D. Portnoy
Related Party Transaction [Line Items]
Equity interest percentage	5.00%
OPI | Related Party | Adam D. Portnoy
Related Party Transaction [Line Items]
Equity interest percentage	5.00%
SVC | Related Party | Adam D. Portnoy
Related Party Transaction [Line Items]
Equity interest percentage	5.00%
TA | Related Party | Adam D. Portnoy
Related Party Transaction [Line Items]
Equity interest percentage	5.00%