Reportable Segments - Net Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Net Operating Income	$ 129,400	$ 124,148	$ 372,058	$ 369,977
Atlanta
Segment Reporting Information [Line Items]
Net Operating Income	46,958	44,513	138,122	130,984
Austin
Segment Reporting Information [Line Items]
Net Operating Income	39,564	38,532	112,496	108,764
Charlotte
Segment Reporting Information [Line Items]
Net Operating Income	11,522	12,852	33,394	43,972
Dallas
Segment Reporting Information [Line Items]
Net Operating Income	3,197	3,424	9,696	10,546
Phoenix
Segment Reporting Information [Line Items]
Net Operating Income	11,145	9,299	29,988	27,252
Tampa
Segment Reporting Information [Line Items]
Net Operating Income	11,254	9,434	32,588	27,755
Other markets
Segment Reporting Information [Line Items]
Net Operating Income	5,760	6,094	15,774	20,704
Office
Segment Reporting Information [Line Items]
Net Operating Income	127,304	122,860	366,289	366,186
Office | Atlanta
Segment Reporting Information [Line Items]
Net Operating Income	46,678	44,333	137,357	130,551
Office | Austin
Segment Reporting Information [Line Items]
Net Operating Income	39,564	38,532	112,496	108,764
Office | Charlotte
Segment Reporting Information [Line Items]
Net Operating Income	10,587	12,491	30,845	43,176
Office | Dallas
Segment Reporting Information [Line Items]
Net Operating Income	3,197	3,424	9,696	10,546
Office | Phoenix
Segment Reporting Information [Line Items]
Net Operating Income	11,145	9,299	29,988	27,252
Office | Tampa
Segment Reporting Information [Line Items]
Net Operating Income	11,254	9,434	32,588	27,755
Office | Other markets
Segment Reporting Information [Line Items]
Net Operating Income	4,879	5,347	13,319	18,142
Non-Office
Segment Reporting Information [Line Items]
Net Operating Income	2,096	1,288	5,769	3,791
Non-Office | Atlanta
Segment Reporting Information [Line Items]
Net Operating Income	280	180	765	433
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	935	361	2,549	796
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	$ 881	$ 747	$ 2,455	$ 2,562