Reportable Segments - Segment Revenues (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]
Total Revenues	$ 195,170	$ 188,732	$ 567,748	$ 564,919
Rental property revenues
Segment Reporting Information [Line Items]
Total Revenues	193,455	185,515	559,856	552,088
Rental property revenues | Office
Segment Reporting Information [Line Items]
Total Revenues	192,139	184,794	556,252	550,215
Rental property revenues | Non-Office
Segment Reporting Information [Line Items]
Total Revenues	1,316	721	3,604	1,873
Rental property revenues | Operating segments
Segment Reporting Information [Line Items]
Total Revenues	197,849	193,509	572,500	575,462
Rental property revenues | Operating segments | Atlanta
Segment Reporting Information [Line Items]
Total Revenues	71,169	68,328	208,905	199,500
Rental property revenues | Operating segments | Austin
Segment Reporting Information [Line Items]
Total Revenues	64,522	65,448	184,800	183,158
Rental property revenues | Operating segments | Charlotte
Segment Reporting Information [Line Items]
Total Revenues	15,659	18,248	45,380	62,451
Rental property revenues | Operating segments | Dallas
Segment Reporting Information [Line Items]
Total Revenues	4,240	4,337	12,568	13,351
Rental property revenues | Operating segments | Phoenix
Segment Reporting Information [Line Items]
Total Revenues	15,135	12,847	42,098	38,067
Rental property revenues | Operating segments | Tampa
Segment Reporting Information [Line Items]
Total Revenues	18,229	14,444	52,369	43,180
Rental property revenues | Operating segments | Other markets
Segment Reporting Information [Line Items]
Total Revenues	8,895	9,857	26,380	35,755
Rental property revenues | Operating segments | Office
Segment Reporting Information [Line Items]
Total Revenues	194,653	191,264	563,616	568,620
Rental property revenues | Operating segments | Office | Atlanta
Segment Reporting Information [Line Items]
Total Revenues	70,708	67,959	207,582	198,461
Rental property revenues | Operating segments | Office | Austin
Segment Reporting Information [Line Items]
Total Revenues	64,522	65,448	184,800	183,158
Rental property revenues | Operating segments | Office | Charlotte
Segment Reporting Information [Line Items]
Total Revenues	14,343	17,527	41,776	60,578
Rental property revenues | Operating segments | Office | Dallas
Segment Reporting Information [Line Items]
Total Revenues	4,240	4,337	12,568	13,351
Rental property revenues | Operating segments | Office | Phoenix
Segment Reporting Information [Line Items]
Total Revenues	15,135	12,847	42,098	38,067
Rental property revenues | Operating segments | Office | Tampa
Segment Reporting Information [Line Items]
Total Revenues	18,229	14,444	52,369	43,180
Rental property revenues | Operating segments | Office | Other markets
Segment Reporting Information [Line Items]
Total Revenues	7,476	8,702	22,423	31,825
Rental property revenues | Operating segments | Non-Office
Segment Reporting Information [Line Items]
Total Revenues	3,196	2,245	8,884	6,842
Rental property revenues | Operating segments | Non-Office | Atlanta
Segment Reporting Information [Line Items]
Total Revenues	461	369	1,323	1,039
Rental property revenues | Operating segments | Non-Office | Austin
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Rental property revenues | Operating segments | Non-Office | Charlotte
Segment Reporting Information [Line Items]
Total Revenues	1,316	721	3,604	1,873
Rental property revenues | Operating segments | Non-Office | Dallas
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Rental property revenues | Operating segments | Non-Office | Phoenix
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Rental property revenues | Operating segments | Non-Office | Tampa
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Rental property revenues | Operating segments | Non-Office | Other markets
Segment Reporting Information [Line Items]
Total Revenues	1,419	1,155	3,957	3,930
Rental property revenues | Segment reconciling items
Segment Reporting Information [Line Items]
Total Revenues	(4,394)	(7,994)	(12,644)	(23,374)
Rental property revenues | Segment reconciling items | Office
Segment Reporting Information [Line Items]
Total Revenues	(2,514)	(6,470)	(7,364)	(18,405)
Rental property revenues | Segment reconciling items | Non-Office
Segment Reporting Information [Line Items]
Total Revenues	$ (1,880)	$ (1,524)	$ (5,280)	$ (4,969)