Investment in Unconsolidated Ventures (Tables)

12 Months Ended

Dec. 31, 2011

Equity Method Investments and Joint Ventures [Abstract]

Schedule of equity method investments

	Ownership Percentage (a)		Carrying Amount			Company’s Share of 2011 Real Estate Venture Income (Loss)			Real Estate Venture Debt at 100%		Current Interest Rate		Debt Maturity
Broadmoor Austin Associates	50	%	$	66,150		$	197		$	66,810	7.04	%	Apr-2023
Brandywine-AI Venture LLC (b)	50	%	24,670			(278		)	68,000		(b)		(b)
Macquarie BDN Christina LLC	20	%	6,168			875			60,000		4.50	%	June-2016
One Commerce Square (c)	25	%	5,100			242			128,529		5.67	%	Dec-15
Brandywine 1919 Ventures (d)	50	%	4,882			—			—		N/A		N/A
Two Commerce Square (c)	25	%	3,415			224			107,112		6.30	%	May-13
1000 Chesterbrook Blvd.	50	%	1,745			245			26,000		4.75	%	Dec-21
Four Tower Bridge (e)	65	%	1,360			702			10,870		5.20	%	Feb-21
G&I Interchange Office LLC (DRA — N. PA) (f)	20	%	1,239			76			181,967		5.78	%	Jan-15
Residence Inn Tower Bridge	50	%	481			433			14,261		5.63	%	Feb-16
PJP VII	25	%	472			190			8,072		L+1.55%		Nov-13
PJP V	25	%	361			116			5,789		6.47	%	Aug-19
PJP II	30	%	300			138			4,263		6.12	%	Nov-23
Six Tower Bridge (e)	63	%	201			126			12,599		7.79	%	Aug-12
Two Tower Bridge	35	%	134			(364		)	13,482		(g)		(g)
Seven Tower Bridge	20	%	105			—			11,182		(h)		(h)
PJP VI	25	%	31			67			8,834		6.08	%	Apr-23
Eight Tower Bridge	3.4	%	—			583			—
Coppell Associates (e)	50	%	(1,007		)	(139		)	18,060		(i)		(i)
Five Tower Bridge			—			60
Invesco, L.P.			—			282
			$	115,807		$	3,775		$	745,830

(a) Ownership percentage represents the Company’s entitlement to residual distributions after payments of priority returns, where applicable.

(b) See Note 3 for related discussion about the Brandywine-AI Venture, LLC formation.

(c) During November, 2010, the Company acquired a 25% interest in two partnerships which own One and Two Commerce Square buildings in Philadelphia, PA. The other partner holds the remaining 75% interest in each of the two partnerships. In accordance with the accounting guidance for joint ventures, the Company is currently recognizing its preferred return from the real estate ventures as income on its invested capital. After the other partner has recognized the losses equal to its invested capital, the Company will begin to recognize its share from the results of the real estate ventures in proportion to its ownership interests.

(d) See Note 3 for related discussion about the Brandywine 1919 Market Ventures formation.

(e) As a result of the adoption of the new accounting standard for the consolidation of variable interest entities, the Company deconsolidated these three real estate ventures as of January 1, 2010.

(f) Proceeds received by the Company from the sale of an 80% ownership stake in the properties exceeded the historical cost of those properties. Accordingly, no investment in the real estate venture was reflected on the balance sheet at period end.

(g) Consists of a $10.1 million fixed rate mortgage with a 5.72% interest rate and May 2013 maturity date; also includes $3.4 million municipal and state borrowings with nominal interest rates (0 — 1%) and maturity dates from 3 to 10 years.

(h) Comprised of two fixed rate mortgages: $7.0 million and $1.0 million. Both mature in February 2013 and accrue interest at a fixed rate of 4% through February 2012, and 5% through February 2013. The total loan amount of $11.2 million as presented above also includes a 3% fixed rate loan (interest only through maturity) with a balance of $1.2 million as of December 31, 2011. This loan can be increased up to $1.3 million through its maturity date of September 2025. The remaining $2.0 million of the total amount features a 4% fixed rate with interest only through its maturity date of February 2014.

(i) Comprised of two fixed rate mortgages: a senior fixed rate note of $16.4 million at 5.75% that matures in March 2016 and a junior fixed rate note of $1.6 million at 6.89% that matures in December 2013; 5.89% is the blended rate.

Financial position of unconsolidated Real Estate Ventures

	December 31,
	2011		2010
Net property	$	846,643	$	804,705
Other assets	110,520		105,576
Other Liabilities	48,798		44,509
Debt	745,830		748,387
Equity	162,535		117,385
Company’s share of equity (Company’s basis)	115,807		84,372

Summary of results of operations of unconsolidated Real Estate Ventures

	Years ended December 31,
	2011 (a)		2010 (a)		2009
Revenue	$	145,867	$	118,923	$	105,236
Operating expenses	63,715		44,942		38,691
Interest expense, net	42,032		37,505		30,858
Depreciation and amortization	39,172		32,703		36,700
Net income	948		3,773		(1,012		)
Company’s share of income (Company’s basis)	3,775		5,305		4,069

(a) - Includes the three real estate ventures that were deconsolidated upon the adoption of the accounting standard for the consolidation of VIEs on January 1, 2010

Schedule of aggregate principal payments of recourse and non-recourse debt payable to third-parties

2011	$	24,228
2012	143,705
2013	13,809
2014	306,051
2015	97,215
Thereafter	160,822
	$	745,830