CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues:
Rental income									$ 411,667	$ 455,125	$ 439,918
Tenant reimbursements									92,743	98,139	94,901
Total revenues	$ 137,185	$ 129,708	$ 129,174	$ 129,900	$ 139,444	$ 137,587	$ 148,679	$ 148,463	525,967	574,173	555,715
Expenses:
Property operating costs									209,338	222,441	220,796
Depreciation									107,956	119,288	127,733
Amortization									63,295	75,367	75,119
Impairment loss on real estate assets									0	46,461	33,901
General and administrative									29,713	29,319	27,382
Operating Expenses									410,302	492,876	484,931
Real estate operating income									115,665	81,297	70,784
Other income (expense):
Interest expense									(61,023)	(68,124)	(64,860)
Other income/(expense)									1,638	657	(13)
Net recoveries from casualty events									0	0	34
Equity in income of unconsolidated joint ventures									0	3,845	362
Loss on extinguishment of debt									(1,680)	0	0
Gain on sale of real estate assets, net	30,505	0	(23)	45,209	(77)	109,512	6,492	(53)	75,691	115,874	93,410
Nonoperating Income (Expense)									14,626	52,252	28,933
Net income	45,409	16,114	10,940	57,828	(31,388)	126,129	23,707	15,101	130,291	133,549	99,717
Net loss applicable to noncontrolling interest									5	15	15
Net income applicable to Piedmont	$ 45,410	$ 16,114	$ 10,942	$ 57,830	$ (31,383)	$ 126,133	$ 23,710	$ 15,104	$ 130,296	$ 133,564	$ 99,732
Per share information— basic and diluted:
Net income available to common stockholders (in dollars per share)					$ (0.21)	$ 0.87	$ 0.16	$ 0.10	$ 1.00	$ 0.92	$ 0.69
Weighted-average shares outstanding - basic (in shares)									130,161,202	145,043,503	145,230,382
Weighted-average shares outstanding - diluted (in shares)									130,635,650	145,379,994	145,634,953
Property management fee revenue
Revenues:
Property related revenue									$ 1,450	$ 1,735	$ 1,914
Other property related income
Revenues:
Property related revenue									$ 20,107	$ 19,174	$ 18,982