Guarantor and Non-Guarantor Financial Information - Condensed Consolidated Statements of Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended				12 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013		Dec. 31, 2013
Revenues:
Rental income	$ 113,287		$ 107,951		$ 224,191		$ 214,006
Tenant reimbursements	24,745		24,101		49,674		49,566
Property management fee revenue	548		513		1,035		1,144
Total revenues	138,580		132,565		274,900		264,716
Expenses:
Property operating costs	57,136		52,223		115,407		104,378
Depreciation	34,144		30,169		67,788		58,994
Amortization	13,599		11,201		28,172		20,210
General and administrative	7,145		6,279		11,700		10,827
Operating Expenses	112,024		99,872		223,067		194,409
Real estate operating income	26,556		32,693		51,833		70,307
Other income (expense):
Interest expense	(18,012)		(18,228)		(36,938)		(34,601)
Other income/(expense)	(366)		(72)		(456)		(1,349)
Net recoveries from casualty events and litigation settlements	1,480		3,553		4,522		3,392
Equity in income/(loss) of unconsolidated joint ventures	(333)		163		(599)		558
Nonoperating Income (Expense)	(17,231)		(14,584)		(33,471)		(32,000)
Income from continuing operations	9,325		18,109		18,362		38,307
Discontinued operations:
Operating income	514		995		980		1,854
Impairment loss	0	[1]	0	[1]	0	[1]	(6,402)	[1]
Gain on sale of real estate assets, net	1,304		16,258		1,198		16,258
Income from discontinued operations	1,818		17,253		2,178		11,710
Gain on sale of real estate assets	1,140		0		1,140		0
Net income	12,283		35,362		21,680		50,017
Less: Net income attributable to noncontrolling interest	(4)		(4)		(8)		(8)
Net income attributable to Piedmont	12,279		35,358		21,672		50,009		98,728
Issuer [Member]
Revenues:
Rental income	17,109		17,057		34,510		34,016
Tenant reimbursements	3,917		3,951		7,778		7,800
Property management fee revenue	0		0		0		0
Total revenues	21,026		21,008		42,288		41,816
Expenses:
Property operating costs	10,330		9,394		20,375		18,829
Depreciation	5,650		5,577		11,490		11,097
Amortization	1,105		1,205		2,217		2,417
General and administrative	6,949		6,013		11,418		10,391
Operating Expenses	24,034		22,189		45,500		42,734
Real estate operating income	(3,008)		(1,181)		(3,212)		(918)
Other income (expense):
Interest expense	(12,482)		(5,410)		(21,602)		(9,034)
Other income/(expense)	2,797		2,793		5,560		5,571
Net recoveries from casualty events and litigation settlements	1		1,038		1,352		1,096
Equity in income/(loss) of unconsolidated joint ventures	(333)		163		(599)		558
Nonoperating Income (Expense)	(10,017)		(1,416)		(15,289)		(1,809)
Income from continuing operations	(13,025)		(2,597)		(18,501)		(2,727)
Discontinued operations:
Operating income	461		711		941		1,181
Impairment loss							(6,402)
Gain on sale of real estate assets, net	557		(9)		451		(9)
Income from discontinued operations	1,018		702		1,392		(5,230)
Gain on sale of real estate assets	0				0
Net income	(12,007)		(1,895)		(17,109)		(7,957)
Less: Net income attributable to noncontrolling interest	0		0		0		0
Net income attributable to Piedmont	(12,007)		(1,895)		(17,109)		(7,957)
Guarantor [Member]
Revenues:
Rental income	0		0		0		0
Tenant reimbursements	0		0		0		0
Property management fee revenue	0		0		0		0
Total revenues	0		0		0		0
Expenses:
Property operating costs	0		0		0		0
Depreciation	0		0		0		0
Amortization	0		0		0		0
General and administrative	66		67		143		185
Operating Expenses	66		67		143		185
Real estate operating income	(66)		(67)		(143)		(185)
Other income (expense):
Interest expense	0		0		0		0
Other income/(expense)	35		44		69		87
Net recoveries from casualty events and litigation settlements	1,479		0		1,479		0
Equity in income/(loss) of unconsolidated joint ventures	0		0		0		0
Nonoperating Income (Expense)	1,514		44		1,548		87
Income from continuing operations	1,448		(23)		1,405		(98)
Discontinued operations:
Operating income	0		0		0		0
Impairment loss							0
Gain on sale of real estate assets, net	0		0		0		0
Income from discontinued operations	0		0		0		0
Gain on sale of real estate assets	0				0
Net income	1,448		(23)		1,405		(98)
Less: Net income attributable to noncontrolling interest	0		0		0		0
Net income attributable to Piedmont	1,448		(23)		1,405		(98)
Non-Guarantor Subsidiaries [Member]
Revenues:
Rental income	97,694		92,125		192,850		182,439
Tenant reimbursements	20,921		20,219		42,100		41,905
Property management fee revenue	3,939		3,931		8,110		7,389
Total revenues	122,554		116,275		243,060		231,733
Expenses:
Property operating costs	52,008		47,464		105,886		94,481
Depreciation	28,494		24,592		56,298		47,897
Amortization	12,494		9,996		25,955		17,793
General and administrative	7,851		7,009		13,812		12,427
Operating Expenses	100,847		89,061		201,951		172,598
Real estate operating income	21,707		27,214		41,109		59,135
Other income (expense):
Interest expense	(8,664)		(15,960)		(21,603)		(31,851)
Other income/(expense)	(64)		234		182		(723)
Net recoveries from casualty events and litigation settlements	0		2,515		1,691		2,296
Equity in income/(loss) of unconsolidated joint ventures	0		0		0		0
Nonoperating Income (Expense)	(8,728)		(13,211)		(19,730)		(30,278)
Income from continuing operations	12,979		14,003		21,379		28,857
Discontinued operations:
Operating income	53		284		39		673
Impairment loss							0
Gain on sale of real estate assets, net	747		16,267		747		16,267
Income from discontinued operations	800		16,551		786		16,940
Gain on sale of real estate assets	1,140				1,140
Net income	14,919		30,554		23,305		45,797
Less: Net income attributable to noncontrolling interest	(4)		(4)		(8)		(8)
Net income attributable to Piedmont	14,915		30,550		23,297		45,789
Eliminations [Member]
Revenues:
Rental income	(1,516)		(1,231)		(3,169)		(2,449)
Tenant reimbursements	(93)		(69)		(204)		(139)
Property management fee revenue	(3,391)		(3,418)		(7,075)		(6,245)
Total revenues	(5,000)		(4,718)		(10,448)		(8,833)
Expenses:
Property operating costs	(5,202)		(4,635)		(10,854)		(8,932)
Depreciation	0		0		0		0
Amortization	0		0		0		0
General and administrative	(7,721)		(6,810)		(13,673)		(12,176)
Operating Expenses	(12,923)		(11,445)		(24,527)		(21,108)
Real estate operating income	7,923		6,727		14,079		12,275
Other income (expense):
Interest expense	3,134		3,142		6,267		6,284
Other income/(expense)	(3,134)		(3,143)		(6,267)		(6,284)
Net recoveries from casualty events and litigation settlements	0		0		0		0
Equity in income/(loss) of unconsolidated joint ventures	0		0		0		0
Nonoperating Income (Expense)	0		(1)		0		0
Income from continuing operations	7,923		6,726		14,079		12,275
Discontinued operations:
Operating income	0		0		0		0
Impairment loss							0
Gain on sale of real estate assets, net	0		0		0		0
Income from discontinued operations	0		0		0		0
Gain on sale of real estate assets	0				0
Net income	7,923		6,726		14,079		12,275
Less: Net income attributable to noncontrolling interest	0		0		0		0
Net income attributable to Piedmont	$ 7,923		$ 6,726		$ 14,079		$ 12,275

[1] Piedmont sold the 1111 Durham Avenue building in South Plainfield, New Jersey and recorded an impairment charge of $6.4 million based on the difference between carrying value and fair value of the asset at the time it was reclassified from real estate assets held-for-use (at cost) to real estate assets held for sale (at estimated fair value). The fair value measurement used in the evaluation of this non-financial asset was based upon the amount set forth in the purchaser's original letter of intent which approximated the land value of the asset due to the age of construction and lack of near term leasing prospects for the building.