Segment Reporting - Reconciliation of GAAP Net Income to NOI (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting [Abstract]
Net income applicable to Piedmont	$ 59,964	$ 9,344
Management fee revenue	(362)	(390)
Depreciation and amortization	53,767	51,015
General and administrative	7,595	7,251
Interest expense	13,898	12,580
Other income	(1,808)	(2,141)
Gain on sale of real estate assets	(50,673)	0
Net loss applicable to noncontrolling interests	0	(1)
NOI	$ 82,381	$ 77,658