Reportable Segments - Segment Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Total Revenues	$ 186,898	$ 189,550
Rental property revenues
Segment Reporting Information [Line Items]
Total Revenues	183,227	184,807
Rental property revenues | Office
Segment Reporting Information [Line Items]
Total Revenues	182,242	184,248
Rental property revenues | Non-Office
Segment Reporting Information [Line Items]
Total Revenues	985	559
Rental property revenues | Operating segments
Segment Reporting Information [Line Items]
Total Revenues	187,385	192,044
Rental property revenues | Operating segments | Atlanta
Segment Reporting Information [Line Items]
Total Revenues	68,437	65,151
Rental property revenues | Operating segments | Austin
Segment Reporting Information [Line Items]
Total Revenues	61,224	58,033
Rental property revenues | Operating segments | Charlotte
Segment Reporting Information [Line Items]
Total Revenues	14,488	21,727
Rental property revenues | Operating segments | Dallas
Segment Reporting Information [Line Items]
Total Revenues	4,196	4,484
Rental property revenues | Operating segments | Phoenix
Segment Reporting Information [Line Items]
Total Revenues	13,430	12,738
Rental property revenues | Operating segments | Tampa
Segment Reporting Information [Line Items]
Total Revenues	16,924	14,571
Rental property revenues | Operating segments | Other markets
Segment Reporting Information [Line Items]
Total Revenues	8,686	15,340
Rental property revenues | Operating segments | Office
Segment Reporting Information [Line Items]
Total Revenues	184,619	189,881
Rental property revenues | Operating segments | Office | Atlanta
Segment Reporting Information [Line Items]
Total Revenues	68,014	64,792
Rental property revenues | Operating segments | Office | Austin
Segment Reporting Information [Line Items]
Total Revenues	61,224	58,033
Rental property revenues | Operating segments | Office | Charlotte
Segment Reporting Information [Line Items]
Total Revenues	13,503	21,168
Rental property revenues | Operating segments | Office | Dallas
Segment Reporting Information [Line Items]
Total Revenues	4,196	4,484
Rental property revenues | Operating segments | Office | Phoenix
Segment Reporting Information [Line Items]
Total Revenues	13,430	12,738
Rental property revenues | Operating segments | Office | Tampa
Segment Reporting Information [Line Items]
Total Revenues	16,924	14,571
Rental property revenues | Operating segments | Office | Other markets
Segment Reporting Information [Line Items]
Total Revenues	7,328	14,095
Rental property revenues | Operating segments | Non-Office
Segment Reporting Information [Line Items]
Total Revenues	2,766	2,163
Rental property revenues | Operating segments | Non-Office | Atlanta
Segment Reporting Information [Line Items]
Total Revenues	423	359
Rental property revenues | Operating segments | Non-Office | Austin
Segment Reporting Information [Line Items]
Total Revenues	0	0
Rental property revenues | Operating segments | Non-Office | Charlotte
Segment Reporting Information [Line Items]
Total Revenues	985	559
Rental property revenues | Operating segments | Non-Office | Dallas
Segment Reporting Information [Line Items]
Total Revenues	0	0
Rental property revenues | Operating segments | Non-Office | Phoenix
Segment Reporting Information [Line Items]
Total Revenues	0	0
Rental property revenues | Operating segments | Non-Office | Tampa
Segment Reporting Information [Line Items]
Total Revenues	0	0
Rental property revenues | Operating segments | Non-Office | Other markets
Segment Reporting Information [Line Items]
Total Revenues	1,358	1,245
Rental property revenues | Segment reconciling items
Segment Reporting Information [Line Items]
Total Revenues	(4,158)	(7,237)
Rental property revenues | Segment reconciling items | Office
Segment Reporting Information [Line Items]
Total Revenues	(2,377)	(5,633)
Rental property revenues | Segment reconciling items | Non-Office
Segment Reporting Information [Line Items]
Total Revenues	$ (1,781)	$ (1,604)