Segment Information (Tables)

3 Months Ended

Mar. 31, 2014

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment [Table Text Block]

Segment information is as follows (in thousands):

	Pennsylvania Suburbs		Philadelphia CBD			Metropolitan Washington, D.C.		New Jersey/Delaware		Richmond, Virginia			Austin, Texas		California		Corporate			Total
As of March 31, 2014:
Real estate investments, at cost:
Operating properties	$	1,209,328	$	1,318,170		$	1,219,542	$	414,353	$	310,465		$	36,480	$	192,951	$	—		$	4,701,289
Construction-in-progress																	90,140			90,140
Land inventory																	96,427			96,427
Investment in real estate ventures, at equity (a)	$	17,379	$	20,131		$	59,847	$	—	$	1,355		$	81,525	$	—	$	—		$	180,237
As of December 31, 2013:
Real estate investments, at cost:
Operating properties	$	1,199,105	$	1,300,666		$	1,214,965	$	414,716	$	310,397		$	36,856	$	192,584	$	—		$	4,669,289
Construction-in-progress																	74,174			74,174
Land inventory																	93,351			93,351
Investment in real estate ventures, at equity	$	17,272	$	19,975		$	59,905	$	—	$	1,400		$	81,960	$	—	$	—		$	180,512
For the three-month period ended March 31, 2014:
Total revenue	$	40,574	$	49,414		$	30,690	$	15,625	$	8,867		$	2,081	$	4,602	$	261		$	152,114
Property operating expenses, real estate taxes and third party management expenses	14,687		18,443			11,957		8,692		4,340			1,176		2,409		270			61,974
Net operating income	$	25,887	$	30,971		$	18,733	$	6,933	$	4,527		$	905	$	2,193	$	(9	)	$	90,140
Equity in income of real estate ventures	$	32	$	(21	)	$	67	$	18	$	(45	)	$	191	$	—	$	—		$	242
For the three-month period ended March 31, 2013:
Total revenue	$	37,916	$	35,925		$	27,785	$	14,919	$	8,765		$	9,257	$	4,605	$	382		$	139,554
Property operating expenses, real estate taxes and third party management expenses	14,436		13,534			10,763		7,031		3,683			3,958		2,160		(496		)	55,069
Net operating income	$	23,480	$	22,391		$	17,022	$	7,888	$	5,082		$	5,299	$	2,445	$	878		$	84,485
Equity in income of real estate ventures	$	31	$	566		$	16	$	908	$	(8	)	$	22	$	—	$	—		$	1,535

(a) Does not include the negative investment balance of one real estate venture totaling $1.2 million as of March 31, 2014, which was included in other liabilities.

Reconciliation Of Consolidated Net Operating Income [Table Text Block]

	Three month periods ended March 31,
	2014			2013
	(amounts in thousands)
Consolidated net operating income	$	90,140		$	84,485
Less:
Interest expense	(31,844		)	(30,914		)
Interest expense - amortization of deferred financing costs	(1,189		)	(1,161		)
Interest expense - financing obligation	(272		)	(218		)
Depreciation and amortization	(52,570		)	(49,476		)
General and administrative expenses	(8,181		)	(6,551		)
Loss on real estate venture transactions	(135		)	—
Loss on early extinguishment of debt	—			(3		)
Plus:
Interest income	385			58
Equity in income of real estate ventures	242			1,535
Gain on sale of undepreciated real estate	1,187			—
Loss from continuing operations	(2,237		)	(2,245		)
Income (loss) from discontinued operations	(8		)	6,164
Net income (loss)	$	(2,245	)	$	3,919