CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Rental and tenant reimbursement revenue									$ 511,905	$ 504,410	$ 553,264
Total revenues	$ 134,153	$ 135,421	$ 130,668	$ 132,936	$ 137,185	$ 129,708	$ 129,174	$ 129,900	533,178	525,967	574,173
Expenses:
Property operating costs									211,380	209,338	222,441
Depreciation									106,015	107,956	119,288
Amortization									76,666	63,295	75,367
Impairment loss on real estate assets									8,953	0	46,461
General and administrative									37,895	29,713	29,319
Expenses									440,909	410,302	492,876
Other income (expense):
Interest expense									(61,594)	(61,023)	(68,124)
Other income/(expense)									1,571	1,638	657
Equity in income of unconsolidated joint ventures									0	0	3,845
Loss on extinguishment of debt									0	(1,680)	0
Gain on sale of real estate assets, net	157,640	32	1,451	37,887	30,505	0	(23)	45,209	197,010	75,691	115,874
Nonoperating Income (Expense)									136,987	14,626	52,252
Net income	162,476	8,419	8,152	50,209	45,409	16,114	10,940	57,828	229,256	130,291	133,549
Net loss applicable to noncontrolling interest									5	5	15
Net income applicable to Piedmont	$ 162,478	$ 8,422	$ 8,153	$ 50,208	$ 45,410	$ 16,114	$ 10,942	$ 57,830	$ 229,261	$ 130,296	$ 133,564
Per share information— basic and diluted:
Net income available to common stockholders (in dollars per share)	$ 1.29	$ 0.07	$ 0.06	$ 0.40					$ 1.82	$ 1.00	$ 0.92
Weighted-average shares outstanding - basic (in shares)									125,709,207	130,161,202	145,043,503
Weighted-average shares outstanding - diluted (in shares)									126,182,137	130,635,650	145,379,994
Property management fee revenue
Revenues:
Property related revenue									$ 3,398	$ 1,450	$ 1,735
Other property related income
Revenues:
Property related revenue									$ 17,875	$ 20,107	$ 19,174