Organization and Basis of Presentation - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2021 ft² Property
Easterly Government Properties LP [Member]
Organization And Significant Accounting Policies [Line Items]
Outstanding common units of aggregate limited partnership interest owned percentage	88.20%
Wholly Owned Operating Properties [Member]
Organization And Significant Accounting Policies [Line Items]
Number of properties	83
Leased percentage of operating properties	99.00%
Aggregate area of land | ft²	7,600,000
Wholly Owned Operating Properties [Member] | Government [Member]
Organization And Significant Accounting Policies [Line Items]
Number of properties	81
Wholly Owned Operating Properties [Member] | Private Tenants [Member]
Organization And Significant Accounting Policies [Line Items]
Number of properties	2
Wholly Owned Properties Under Development [Member]
Organization And Significant Accounting Policies [Line Items]
Number of properties	1
Aggregate area of land | ft²	200,000