Merger With Tier REIT, Inc. - (Pro Forma Information) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Business Combinations [Abstract]
Revenues	$ 182,288	$ 367,319
Net income	62,092	87,744
Net income available to common stockholders	$ 61,211	$ 86,576