Organization and Basis of Presentation - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2020 ft² Property
Organization And Significant Accounting Policies [Line Items]
Area excluded from total rentable area | ft²	15,215
Easterly Government Properties LP [Member]
Organization And Significant Accounting Policies [Line Items]
Outstanding common units of aggregate limited partnership interest owned percentage	87.70%
Wholly Owned Operating Properties [Member]
Organization And Significant Accounting Policies [Line Items]
Number of properties	72
Leased percentage of operating properties	100.00%
Aggregate area of land | ft²	6,800,000
Wholly Owned Operating Properties [Member] | Government [Member]
Organization And Significant Accounting Policies [Line Items]
Number of properties	70
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	2
Aggregate area of land | ft²	200,000