Transactions With Tier Reit, Inc. (Pro Forma Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Business Combinations [Abstract]
Revenues	$ 750,080	$ 702,463
Net income	232,136	28,064
Net income available to common stockholders	$ 229,503	$ 27,742