Related Person Transactions - Narrative (Details)	Mar. 31, 2022 shares
ALR
Related Party Transaction [Line Items]
Ownership percentage	6.20%
SVC
Related Party Transaction [Line Items]
Ownership percentage	1.10%
ILPT
Related Party Transaction [Line Items]
Ownership percentage	1.20%
OPI
Related Party Transaction [Line Items]
Ownership percentage	1.50%
DHC
Related Party Transaction [Line Items]
Ownership percentage	1.10%
TA
Related Party Transaction [Line Items]
Ownership percentage	4.40%
SEVN
Related Party Transaction [Line Items]
Ownership percentage	7.40%
ABP Trust | Class A Common Stock
Related Party Transaction [Line Items]
Common stock shares outstanding (in shares)	173,502
ABP Trust | Class A Units
Related Party Transaction [Line Items]
Common stock shares outstanding (in shares)	15,000,000