Reportable Segments - Segment Net Operating Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Total Net Operating Income	$ 502,200	$ 493,720	$ 486,034
Atlanta
Segment Reporting Information [Line Items]
Total Net Operating Income	185,649	177,415	172,539
Austin
Segment Reporting Information [Line Items]
Total Net Operating Income	152,806	146,923	125,215
Charlotte
Segment Reporting Information [Line Items]
Total Net Operating Income	44,836	54,645	65,203
Dallas
Segment Reporting Information [Line Items]
Total Net Operating Income	12,890	14,014	14,586
Phoenix
Segment Reporting Information [Line Items]
Total Net Operating Income	41,544	36,244	33,440
Tampa
Segment Reporting Information [Line Items]
Total Net Operating Income	45,187	38,305	37,358
Other markets
Segment Reporting Information [Line Items]
Total Net Operating Income	19,288	26,174	37,693
Office
Segment Reporting Information [Line Items]
Total Net Operating Income	495,149	488,364	481,409
Office | Atlanta
Segment Reporting Information [Line Items]
Total Net Operating Income	184,609	176,793	172,588
Office | Austin
Segment Reporting Information [Line Items]
Total Net Operating Income	152,806	146,923	125,215
Office | Charlotte
Segment Reporting Information [Line Items]
Total Net Operating Income	41,234	53,294	63,876
Office | Dallas
Segment Reporting Information [Line Items]
Total Net Operating Income	12,890	14,014	14,586
Office | Phoenix
Segment Reporting Information [Line Items]
Total Net Operating Income	41,544	36,244	37,358
Office | Tampa
Segment Reporting Information [Line Items]
Total Net Operating Income	45,187	38,305	33,440
Office | Other markets
Segment Reporting Information [Line Items]
Total Net Operating Income	16,879	22,791	34,346
Non-Office
Segment Reporting Information [Line Items]
Total Net Operating Income	7,051	5,356	4,625
Non-Office | Atlanta
Segment Reporting Information [Line Items]
Total Net Operating Income	1,040	622	(49)
Non-Office | Austin
Segment Reporting Information [Line Items]
Total Net Operating Income	0	0	0
Non-Office | Charlotte
Segment Reporting Information [Line Items]
Total Net Operating Income	3,602	1,351	1,327
Non-Office | Dallas
Segment Reporting Information [Line Items]
Total Net Operating Income	0	0	0
Non-Office | Phoenix
Segment Reporting Information [Line Items]
Total Net Operating Income	0	0	0
Non-Office | Tampa
Segment Reporting Information [Line Items]
Total Net Operating Income	0	0	0
Non-Office | Other markets
Segment Reporting Information [Line Items]
Total Net Operating Income	$ 2,409	$ 3,383	$ 3,347