Organization and Basis of Presentation - Additional Information (Detail)	3 Months Ended
	Mar. 31, 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	89.00%
Wholly Owned Operating Properties [Member]
Organization And Significant Accounting Policies [Line Items]
Number of properties	82
Leased percentage of operating properties	99.00%
Aggregate area of land | ft²	7,500,000
Wholly Owned Operating Properties [Member] | Government [Member]
Organization And Significant Accounting Policies [Line Items]
Number of properties	80
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