CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Cumulative Distributions in Excess of Earnings	Other Comprehensive Income/(Loss)	Noncontrolling Interest
Beginning balance (in shares) at Dec. 31, 2015		145,512,000
Beginning balance, value at Dec. 31, 2015	$ 2,123,420	$ 1,455	$ 3,669,977	$ (1,550,698)	$ 1,661	$ 1,025
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock repurchases as part of an announced plan (in shares)		(462,000)
Share repurchases as part of an announced plan	(7,943)	$ (5)		(7,938)
Offering costs	(342)		(342)
Noncontrolling interest in consolidated joint venture	888					888
Dividends to common stockholders, dividends to preferred stockholders of subsidiary, and dividends reinvested	(122,148)		(173)	(121,959)		(16)
Shares issued and amortized under the 2007 Omnibus Incentive Plan, net of tax (in shares)		185,000
Shares issued and amortized under the 2007 Omnibus Incentive Plan, net of tax	3,668	$ 2	3,666
Net loss applicable to noncontrolling interest	(15)					(15)
Net income applicable to Piedmont	99,732			99,732
Other comprehensive income	$ 443				443
Ending balance, (in shares) at Dec. 31, 2016	145,235,000	145,235,000
Ending balance, value at Dec. 31, 2016	$ 2,097,703	$ 1,452	3,673,128	(1,580,863)	2,104	1,882
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock repurchases as part of an announced plan (in shares)		(3,133,000)
Share repurchases as part of an announced plan	(61,750)	$ (31)		(61,719)
Offering costs	(182)		(182)
Dividends to common stockholders, dividends to preferred stockholders of subsidiary, and dividends reinvested	(193,541)		(233)	(193,263)		(45)
Shares issued and amortized under the 2007 Omnibus Incentive Plan, net of tax (in shares)		257,000
Shares issued and amortized under the 2007 Omnibus Incentive Plan, net of tax	4,650	$ 3	4,647
Net loss applicable to noncontrolling interest	(15)					(15)
Net income applicable to Piedmont	133,564			133,564
Other comprehensive income	$ 6,060				6,060
Ending balance, (in shares) at Dec. 31, 2017	142,358,940	142,359,000
Ending balance, value at Dec. 31, 2017	$ 1,986,489	$ 1,424	3,677,360	(1,702,281)	8,164	1,822
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock repurchases as part of an announced plan (in shares)		(16,495,000)
Share repurchases as part of an announced plan	(301,678)	$ (165)		(301,513)
Offering costs	(85)		(85)
Dividends to common stockholders, dividends to preferred stockholders of subsidiary, and dividends reinvested	$ (109,265)		(82)	(109,138)		(45)
Shares issued and amortized under the 2007 Omnibus Incentive Plan, net of tax (in shares)	355,055	355,000
Shares issued and amortized under the 2007 Omnibus Incentive Plan, net of tax	$ 5,996	$ 3	5,993
Net loss applicable to noncontrolling interest	(5)					(5)
Net income applicable to Piedmont	130,296			130,296
Other comprehensive income	$ 392				392
Ending balance, (in shares) at Dec. 31, 2018	126,218,554	126,219,000
Ending balance, value at Dec. 31, 2018	$ 1,712,140	$ 1,262	$ 3,683,186	$ (1,982,542)	$ 8,462	$ 1,772