Real Estate

12 Months Ended

Dec. 31, 2012

Real Estate [Abstract]

Real Estate Disclosure [Text Block]

REAL ESTATE

The Company owns and operates industrial and office properties. The carrying value of these properties by type as of December 31, 2012 and 2011 is as follows (in thousands):

	Land	Building
	And Land	And		Accumulated
	Improvements	Improvements	Total	Depreciation
2012
Industrial properties	$445,721	$2,097,334	$2,543,055	$511,259
Office properties	454,780	2,256,099	2,710,879	658,771
2012 Total	$900,501	$4,353,433	$5,253,934	$1,170,030
2011
Industrial properties	$401,849	$1,878,520	$2,280,369	$453,576
Office properties	450,936	2,213,536	2,664,472	593,760
2011 Total	$852,785	$4,092,056	$4,944,841	$1,047,336

Depreciation expense was $140.6 million in 2012, $144.3 million in 2011 and $147.3 million in 2010.

Information on the operating properties the Company sold during the years ended December 31, 2012 and 2011 is as follows:

2012 Sales

	Number of	Leaseable
Reportable Segment	Buildings	Square Feet	Gross Proceeds
			(in thousands)
Northeast
Southeastern PA	3	308,344	$	23,300
Lehigh/Central PA	1	45,000	2,025
Northeast - Other	8	632,758	49,386
Central	20	996,115	69,861
South	18	1,055,840	83,888
Total	50	3,038,057	$	228,460

2011 Sales

	Number of	Leaseable
Reportable Segment	Buildings	Square Feet	Gross Proceeds
			(in thousands)
Northeast
Southeastern PA	1	35,212	$	3,882
Lehigh/Central PA	32	1,422,501	124,000
Northeast - Other	2	91,698	11,351
Central	6	919,480	71,301
South	21	1,750,489	154,656
Total	62	4,219,380	$	365,190