Income Taxes (Details) (USD $)	3 Months Ended								12 Months Ended												12 Months Ended
	Dec. 31, 2013 Property	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013 Y Property		Dec. 31, 2012		Dec. 31, 2011 Property		May 18, 2011	Dec. 31, 2013 Internal Revenue Service (IRS) [Member]	Dec. 19, 2013 Internal Revenue Service (IRS) [Member]	Dec. 19, 2013 CALIFORNIA State and Local Jurisdiction [Member]	Dec. 19, 2013 PENNSYLVANIA State and Local Jurisdiction [Member]	Dec. 31, 2013 TEXAS State and Local Jurisdiction [Member]	Dec. 31, 2012 Management Contract [Member]	Dec. 19, 2013 Thomas Properties Group, Inc. [Member] Wholly Owned Properties [Member] Property	Dec. 19, 2013 Thomas Properties Group, Inc. [Member] Partially Owned Properties [Member] Property
Reconciliation of GAAP net income (loss) to taxable income loss [Abstract]
GAAP net loss	$ (8,557,000)	$ (2,306,000)	$ (7,619,000)	$ (1,168,000)	$ (49,002,000)	$ 2,129,000	$ 2,773,000	$ 4,705,000	$ (19,650,000)		$ (39,395,000)		$ (126,903,000)
Taxable Real Estate Subsidiary Net Income									6,796,000		46,896,000		(9,248,000)
Net Income Loss Excluding Net Income From Taxable Real Estate Investment Trust Subsidiary									(12,854,000)	[1]	7,501,000	[1]	(136,151,000)	[1]
GAAP to tax adjustments [Abstract]
Depreciation and amortization									38,961,000		10,619,000		13,969,000
Gains and losses from capital transactions									(6,731,000)		(115,065,000)		53,699,000
Share-based compensation expense									5,699,000		431,000		1,341,000
Deferred compensation distributions									0		(226,000)		(1,902,000)
Amortization of mortgage loan discount									0		32,000		(335,000)
Allowance for doubtful accounts									858,000		(480,000)		(761,000)
Vesting of restricted shares and dividends									(170,000)		(674,000)		(1,175,000)
Deferred revenue									481,000		(329,000)		(2,525,000)
Capitalizable acquisition costs									12,985,000		2,119,000		11,213,000
Straight line rent									(1,702,000)		(2,883,000)		(2,169,000)
Interest expense									0		(214,000)		2,338,000
Income Tax Reconciliation, Nontaxable Dividend Income									(1,360,000)		(3,707,000)		(1,986,000)
Other differences									(104,000)		829,000		192,000
Taxable income (loss) before adjustments									36,063,000		(102,047,000)		(64,252,000)
Less: NOL carry forward									0		0		0
Adjusted taxable income subject to 90% dividend requirement									36,063,000		0		0
Current [Abstract]
Federal									(488,000)		(914,000)		(420,000)
State									(67,000)		(202,000)		(66,000)
Total Current									(555,000)		(1,116,000)		(486,000)
Deferred [Abstract]
Federal									1,582,000		722,000		363,000
State									378,000		133,000		67,000
Total Deferred									1,960,000		855,000		430,000
Total income tax benefit (expense)	(305,000)	819,000	384,000	507,000	(118,000)	7,000	11,000	(161,000)	1,405,000		(261,000)		(56,000)
Reconciliation of income tax amount attributable to continuing operations [Abstract]
Tax at U.S. statutory rates on consolidated income(loss) subject to tax									1,990,000		(150,000)
State income tax, net of federal tax benefit									185,000		(40,000)
Effect of permanent differences									(291,000)		(37,000)
Excess tax basis of capitalizable transaction costs									(479,000)		0
Other									0		(34,000)
Total income tax benefit (expense)	(305,000)	819,000	384,000	507,000	(118,000)	7,000	11,000	(161,000)	1,405,000		(261,000)		(56,000)
Reconciliation of income tax rate attributable to continuing operations [Abstract]
Tax at U.S. statutory rates on consolidated income(loss) subject to tax (in hundredths)									34.00%		34.00%
State income tax, net of federal tax benefit (in hundredths)									3.20%		9.00%
Effect of permanent differences (in hundredths)									(5.00%)		8.50%
Excess tax basis of capitalizable transaction costs (in hundredths)									(8.20%)		0.00%
Other (in hundredths)									0.00%		7.40%
Total income tax expense (benefit) (in hundredths)									24.00%		58.90%
Operating Loss Carryforwards [Line Items]
REIT annual taxable income distribution requirement (in percent)									90.00%
Number of subsequent taxable years disqualification									4
Net operating loss carryforwards	166,400,000								166,400,000								79,300,000	16,200,000	30,900,000
Income tax valuation allowance	500,000								500,000							71,300,000
Tax benefit associated with non-cash impairment loss on management contracts and goodwill									11,400,000
Consolidated income (loss) subject to tax									5,800,000		41,500,000
Number of real estate properties	43								43				2									2	5
Deferred tax liabilities	2,000,000								2,000,000				14,800,000		14,800,000					11,000
Net deferred tax liabilities					2,000,000						2,000,000
Changes in deferred tax liabilities due valuation of management contracts																					19,000,000
Amortization period (in years)																					2 years 8 months 12 days
Deferred tax asset recorded during period									500,000
Deferred tax assets, net	1,600,000								1,600,000
Reconciliation of cash dividends paid to dividends paid deduction [Abstract]
Cash dividends paid common stock									45,189,000		26,306,000		16,472,000
Less: Dividends on deferred compensation plan shares									0		(3,000)		(3,000)
Less: Dividends absorbed by current earnings and profits									(36,291,000)		0		0
Less: Return of capital									(8,898,000)		(26,303,000)		(16,469,000)
Dividends paid deduction									$ 0		$ 0		$ 0
Income tax treatment for dividends to stockholders [Abstract]
Ordinary income (in dollars per share)									$ 0.443		$ 0.00		$ 0.00
Unrecaptured Section 1250 gain (in dollars per share)									$ 0.083		$ 0.00		$ 0.00
Return of capital (in dollars per share)									$ 0.112		$ 0.38		$ 0.30
Distributions paid per common share (in dollars per share)									$ 0.638		$ 0.38		$ 0.30
Ordinary income (in hundredths)									69.00%		0.00%		0.00%
Unrecaptured Section 1250 gain (in hundredths)									13.00%		0.00%		0.00%
Return of capital (in hundredths)									18.00%		100.00%		100.00%
Distributions per share, cash paid percentage (in hundredths)									100.00%		100.00%		100.00%

[1] GAAP net income (loss) from REIT operations is net of amounts attributable to noncontrolling interests.