Dispositions of Property (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 23, 2020	Dec. 31, 2020
Dispositions of properties
Gain (loss) on sale of property		$ 41,928
Disposal group disposed of by sale, not classified as discontinued operations | Office Property In Durham North California
Dispositions of properties
Gain (loss) on sale of property	$ 41,900
Net Proceeds	$ 89,700