Discontinued Operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended			0 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 08, 2010 Sylvan Avenue 111 Building [Member]	Jul. 02, 2011 Eastpointe Corporate Center [Member]	Aug. 31, 2011 Corporate Court 5000 [Member]	Dec. 15, 2011 W Wacker Building 35 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Sales Proceeds									$ 291,785	$ 51,637	$ 0	$ 51,637	$ 31,704	$ 36,100	$ 223,981	[1]
Percent of Ownership Interest In Real Estate Property Disposal															96.50%
Revenues:
Rental Income									30,839	40,159	39,909
Tenant Reimbursement									18,566	20,348	22,323
Lease termination income									0	1,136	0
Revenue									49,405	61,643	62,232
Expenses:
Property operating costs									20,064	21,798	24,280
Depreciation									4,912	7,215	8,606
Amortization of deferred leasing costs									5,099	6,910	10,941
General and administrative expense									67	249	127
Expenses									30,142	36,172	43,954
Other income (expense):
Interest expense									(5,931)	(6,274)	(6,279)
Interest and other income									1	3	43
Net income attributable to noncontrolling interest									(453)	(516)	(463)
Other income (expense)									(6,383)	(6,787)	(6,699)
Operating income, excluding impairment loss and gain on sale									12,880	18,684	11,579
Impairment loss									0	(9,587)	0
Gain/(loss) on sale of real estate assets									122,657	(817)	0	(817)	12,152	14,367	96,138	[1]
Income from discontinued operations	$ 100,662	$ 29,475	$ 2,645	$ 2,755	$ 4,024	$ 5,268	$ (5,214)	$ 4,202	$ 135,537	$ 8,280	$ 11,579

[1] Piedmont sold its approximate 96.5% ownership in the property. Transaction data above is presented at Piedmont's ownership percentage.