Unconsolidated Joint Ventures -Liberty Washington, LP (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Schedule of Equity Method Investments [Line Items]
Impairment charges - real estate assets	$ 0	$ 26,000	$ 99	$ 26,000
DC Metro
Schedule of Equity Method Investments [Line Items]
Impairment charges - real estate assets	4,000		14,400
DC Metro | Liberty Washington, LP [Member] | Discontinued operations
Schedule of Equity Method Investments [Line Items]
Impairment charges - real estate assets	16,400		16,400
DC Metro | Liberty Property Limited Partnership | Other Investments | Equity Method Investee | Liberty Washington, LP [Member]
Schedule of Equity Method Investments [Line Items]
Impairment charges - real estate assets	$ 4,100		$ 4,100