Reportable Segments - Net Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Net Operating Income	$ 123,051	$ 122,705	$ 242,658	$ 245,829
Atlanta
Segment Reporting Information [Line Items]
Net Operating Income	46,756	43,274	91,164	86,471
Austin
Segment Reporting Information [Line Items]
Net Operating Income	36,565	35,955	72,932	70,232
Charlotte
Segment Reporting Information [Line Items]
Net Operating Income	11,218	15,863	21,873	31,120
Dallas
Segment Reporting Information [Line Items]
Net Operating Income	3,191	3,571	6,498	7,122
Phoenix
Segment Reporting Information [Line Items]
Net Operating Income	9,868	8,928	18,843	17,953
Tampa
Segment Reporting Information [Line Items]
Net Operating Income	10,643	8,919	21,334	18,321
Other markets
Segment Reporting Information [Line Items]
Net Operating Income	4,810	6,195	10,014	14,610
Office
Segment Reporting Information [Line Items]
Net Operating Income	121,164	121,430	238,984	243,326
Office | Atlanta
Segment Reporting Information [Line Items]
Net Operating Income	46,506	43,115	90,679	86,218
Office | Austin
Segment Reporting Information [Line Items]
Net Operating Income	36,565	35,955	72,932	70,232
Office | Charlotte
Segment Reporting Information [Line Items]
Net Operating Income	10,246	15,688	20,258	30,685
Office | Dallas
Segment Reporting Information [Line Items]
Net Operating Income	3,191	3,571	6,498	7,122
Office | Phoenix
Segment Reporting Information [Line Items]
Net Operating Income	9,868	8,928	18,843	17,953
Office | Tampa
Segment Reporting Information [Line Items]
Net Operating Income	10,643	8,919	21,334	18,321
Office | Other markets
Segment Reporting Information [Line Items]
Net Operating Income	4,145	5,254	8,440	12,795
Non-Office
Segment Reporting Information [Line Items]
Net Operating Income	1,887	1,275	3,674	2,503
Non-Office | Atlanta
Segment Reporting Information [Line Items]
Net Operating Income	250	159	485	253
Non-Office | Austin
Segment Reporting Information [Line Items]
Net Operating Income	0	0	0	0
Non-Office | Charlotte
Segment Reporting Information [Line Items]
Net Operating Income	972	175	1,615	435
Non-Office | Dallas
Segment Reporting Information [Line Items]
Net Operating Income	0	0	0	0
Non-Office | Phoenix
Segment Reporting Information [Line Items]
Net Operating Income	0	0	0	0
Non-Office | Tampa
Segment Reporting Information [Line Items]
Net Operating Income	0	0	0	0
Non-Office | Other markets
Segment Reporting Information [Line Items]
Net Operating Income	$ 665	$ 941	$ 1,574	$ 1,815