Guarantor and Non-Guarantor Financial Information- Condensed Consolidated Balance Sheets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2010
Assets:
Land	$ 688,761		$ 629,536
Buildings and improvements, less accumulated depreciation	3,164,575		2,908,078
Intangible lease assets, less accumulated amortization	74,377		54,745
Construction in progress	24,270		20,373
Total real estate assets	3,951,983		3,612,732
Investments in and amounts due from unconsolidated joint ventures	14,388		37,689
Cash and cash equivalents	6,973		12,957		139,690	56,718
Tenant and straight-line receivables, net	170,551		147,337
Advances to affiliates	0		0
Investment in subsidiary	0		0
Notes receivable	0		0
Prepaid expenses, restricted cash, escrows, and other assets	25,165		21,617
Goodwill	180,097		180,097
Interest rate swaps	24,176		1,075
Deferred financing costs, net	8,759		6,454
Deferred lease costs, net	283,996		234,917
Total assets	4,666,088		4,254,875
Liabilities:
Debt	2,002,205	[1]	1,416,525	[1]
Accounts payable, accrued expenses, and accrued capital expenditures	128,818		127,263
Advances from affiliates	0		0
Deferred income	22,267		21,552
Intangible lease liabilities, net	47,113		40,805
Interest rate swaps	4,526		8,235
Total liabilities	2,204,929		1,614,380
Stockholders’ Equity:
Common stock	1,575		1,676
Additional paid-in capital	3,668,906		3,667,051
Cumulative distributions in excess of earnings	(1,231,209)		(1,022,681)
Other comprehensive income/(loss)	20,278		(7,160)
Piedmont stockholders’ equity	2,459,550		2,638,886
Noncontrolling interest	1,609		1,609
Total stockholders’ equity	2,461,159		2,640,495		2,773,428	2,773,454
Total liabilities and stockholders’ equity	4,666,088		4,254,875
Issuer [Member]
Assets:
Land	88,054		93,967
Buildings and improvements, less accumulated depreciation	477,712		528,548
Intangible lease assets, less accumulated amortization	2,356		3,266
Construction in progress	4,627		1,056
Total real estate assets	572,749		626,837
Investments in and amounts due from unconsolidated joint ventures	14,388		37,689
Cash and cash equivalents	3,352		62,371		166,920	61,516
Tenant and straight-line receivables, net	36,142		34,288
Advances to affiliates	5,312,384		4,623,173
Investment in subsidiary	0		0
Notes receivable	160,000		160,000
Prepaid expenses, restricted cash, escrows, and other assets	5,319		5,149
Goodwill	180,097		180,097
Interest rate swaps	24,176		1,075
Deferred financing costs, net	7,764		4,292
Deferred lease costs, net	34,413		30,426
Total assets	6,350,784		5,765,397
Liabilities:
Debt	1,038,570		452,890
Accounts payable, accrued expenses, and accrued capital expenditures	13,824		20,443
Advances from affiliates	312,881		274,159
Deferred income	5,086		5,991
Intangible lease liabilities, net	0		24
Interest rate swaps	4,526		8,235
Total liabilities	1,374,887		761,742
Stockholders’ Equity:
Common stock	0		0
Additional paid-in capital	4,003,806		4,068,844
Cumulative distributions in excess of earnings	951,813		941,971
Other comprehensive income/(loss)	20,278		(7,160)
Piedmont stockholders’ equity	4,975,897		5,003,655
Noncontrolling interest	0		0
Total stockholders’ equity	4,975,897		5,003,655
Total liabilities and stockholders’ equity	6,350,784		5,765,397
Guarantor [Member]
Assets:
Land	0		0
Buildings and improvements, less accumulated depreciation	0		0
Intangible lease assets, less accumulated amortization	0		0
Construction in progress	0		0
Total real estate assets	0		0
Investments in and amounts due from unconsolidated joint ventures	0		0
Cash and cash equivalents	150		239		139	896
Tenant and straight-line receivables, net	0		0
Advances to affiliates	1,288,547		1,300,158
Investment in subsidiary	4,003,806		4,068,844
Notes receivable	2,000		2,500
Prepaid expenses, restricted cash, escrows, and other assets	44		14
Goodwill	0		0
Interest rate swaps	0		0
Deferred financing costs, net	0		0
Deferred lease costs, net	0		0
Total assets	5,294,547		5,371,755
Liabilities:
Debt	0		0
Accounts payable, accrued expenses, and accrued capital expenditures	2,376		645
Advances from affiliates	4,863,672		4,636,936
Deferred income	0		0
Intangible lease liabilities, net	0		0
Interest rate swaps	0		0
Total liabilities	4,866,048		4,637,581
Stockholders’ Equity:
Common stock	1,575		1,676
Additional paid-in capital	3,668,906		3,667,051
Cumulative distributions in excess of earnings	(3,241,982)		(2,934,553)
Other comprehensive income/(loss)	0		0
Piedmont stockholders’ equity	428,499		734,174
Noncontrolling interest	0		0
Total stockholders’ equity	428,499		734,174
Total liabilities and stockholders’ equity	5,294,547		5,371,755
Non-Guarantor Subsidiaries [Member]
Assets:
Land	600,707		535,569
Buildings and improvements, less accumulated depreciation	2,687,163		2,379,530
Intangible lease assets, less accumulated amortization	72,021		51,479
Construction in progress	19,643		19,317
Total real estate assets	3,379,534		2,985,895
Investments in and amounts due from unconsolidated joint ventures	0		0
Cash and cash equivalents	3,471		(49,653)		(27,369)	(5,694)
Tenant and straight-line receivables, net	134,409		113,049
Advances to affiliates	0		0
Investment in subsidiary	197		200
Notes receivable	23,890		23,890
Prepaid expenses, restricted cash, escrows, and other assets	20,779		17,402
Goodwill	0		0
Interest rate swaps	0		0
Deferred financing costs, net	995		2,162
Deferred lease costs, net	249,583		204,491
Total assets	3,812,858		3,297,436
Liabilities:
Debt	1,149,525		1,150,025
Accounts payable, accrued expenses, and accrued capital expenditures	113,595		107,123
Advances from affiliates	1,467,334		1,044,446
Deferred income	17,181		15,561
Intangible lease liabilities, net	47,113		40,781
Interest rate swaps	0		0
Total liabilities	2,794,748		2,357,936
Stockholders’ Equity:
Common stock	0		0
Additional paid-in capital	197		200
Cumulative distributions in excess of earnings	1,016,304		937,691
Other comprehensive income/(loss)	0		0
Piedmont stockholders’ equity	1,016,501		937,891
Noncontrolling interest	1,609		1,609
Total stockholders’ equity	1,018,110		939,500
Total liabilities and stockholders’ equity	3,812,858		3,297,436
Eliminations [Member]
Assets:
Land	0		0
Buildings and improvements, less accumulated depreciation	(300)		0
Intangible lease assets, less accumulated amortization	0		0
Construction in progress	0		0
Total real estate assets	(300)		0
Investments in and amounts due from unconsolidated joint ventures	0		0
Cash and cash equivalents	0		0		0	0
Tenant and straight-line receivables, net	0		0
Advances to affiliates	(6,600,931)		(5,923,331)
Investment in subsidiary	(4,004,003)		(4,069,044)
Notes receivable	(185,890)		(186,390)
Prepaid expenses, restricted cash, escrows, and other assets	(977)		(948)
Goodwill	0		0
Interest rate swaps	0		0
Deferred financing costs, net	0		0
Deferred lease costs, net	0		0
Total assets	(10,792,101)		(10,179,713)
Liabilities:
Debt	(185,890)		(186,390)
Accounts payable, accrued expenses, and accrued capital expenditures	(977)		(948)
Advances from affiliates	(6,643,887)		(5,955,541)
Deferred income	0		0
Intangible lease liabilities, net	0		0
Interest rate swaps	0		0
Total liabilities	(6,830,754)		(6,142,879)
Stockholders’ Equity:
Common stock	0		0
Additional paid-in capital	(4,004,003)		(4,069,044)
Cumulative distributions in excess of earnings	42,656		32,210
Other comprehensive income/(loss)	0		0
Piedmont stockholders’ equity	(3,961,347)		(4,036,834)
Noncontrolling interest	0		0
Total stockholders’ equity	(3,961,347)		(4,036,834)
Total liabilities and stockholders’ equity	$ (10,792,101)		$ (10,179,713)

[1] Weighted average is based on the net book value of outstanding debt and interest rates in the table (or as footnoted) as of December 31, 2013.