Non-Controlling Interests (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 30, 2014
Noncontrolling Interest [Line Items]
Limited partner units (in units)	90	90
Distributions to non-controlling interest holders	$ 346	$ 492	$ 643
Non-controlling Interests
Noncontrolling Interest [Line Items]
Limited partner units (in units)				405,908
Units issued to purchase building				$ 10,100
Units issued to fund purchase of A Building (in dollars per share)				$ 25.00