Real Estate (Tables)

12 Months Ended

Dec. 31, 2016

Real Estate [Abstract]

Schedule of Carrying Value of Properties

The carrying value of these properties by type as of December 31, 2016 and 2015 is as follows (in thousands):

	Land		Building
	and Land		and				Accumulated
	Improvements		Improvements		Total		Depreciation
2016
Industrial properties	$	919,951	$	3,757,063	$	4,677,014	$	734,595
Office properties	174,519		744,858		919,377		205,520
2016 Total	$	1,094,470	$	4,501,921	$	5,596,391	$	940,115
2015
Industrial properties	$	824,140	$	3,637,484	$	4,461,624	$	698,456
Office properties	360,787		1,494,164		1,854,951		450,472
2015 Total	$	1,184,927	$	5,131,648	$	6,316,575	$	1,148,928

Schedule of Operating Properties

Information on the operating properties the Company sold during the years ended December 31, 2016 and 2015 is as follows:

2016 Sales

Reportable Segment	Number of Buildings	Acres of Developable Land (unaudited)	Leaseable Square Feet (unaudited)	Gross Proceeds (in thousands)
Chicago/Milwaukee	1	5	171,114	$	10,625
Florida	51	12	3,509,641	505,828
Lehigh/Central PA	1	—	120,777	11,200
Minnesota	23	—	1,866,161	189,200
Philadelphia	—	1	—	2,640
Southeastern PA	31	—	2,165,002	266,821
Other	18	18	1,631,295	224,241
Total	125	36	9,463,990	$	1,210,555

2015 Sales

Reportable Segment	Number of Buildings	Acres of Developable Land (unaudited)	Leaseable Square Feet (unaudited)	Gross Proceeds (in thousands)
Carolinas/Richmond	22	3	1,319,299	$	110,054
Florida	4	—	874,125	55,425
Minnesota	2	—	222,642	25,700
Southeastern PA	46	20	2,724,489	316,583
Other	7	—	569,618	37,371
Total	81	23	5,710,173	$	545,133

A summary of the results of operations for the properties classified as discontinued operations through the respective disposition dates is as follows (in thousands):

	For the Year Ended
	December 31, 2014
Revenues	$	4,728
Operating expenses	(2,258		)
Interest and other income	37
Interest expense	(557		)
Depreciation and amortization	—
Income before gain on property dispositions	1,950
Gain on property dispositions	46,631
Net income	$	48,581

Schedule of Operating Properties and Land Parcels Acquired

Information on the operating properties and land parcels the Company acquired during the years ended December 31, 2016 and 2015 is as follows:

2016 Acquisitions

Reportable Segment	Number of Buildings	Acres of Developable Land (unaudited)	Leaseable Square Feet (unaudited)	Purchase Price
				(in thousands)
Carolinas/Richmond	—	13	—	$	2,251
Chicago/Milwaukee	1	6	73,160	11,064
Lehigh/Central PA	—	76	—	15,395
Philadelphia	—	6	—	13,943
Southeastern PA	—	8	—	3,344
Other	—	108	—	14,895
Total	1	217	73,160	$	60,892

2015 Acquisitions

Reportable Segment	Number of Buildings	Acres of Developable Land (unaudited)	Leaseable Square Feet (unaudited)	Purchase Price
				(in thousands)
Carolinas/Richmond	—	94	—	$	1,727
Houston	3	139	921,196	86,497
Lehigh/Central PA	—	281	—	62,402
Minnesota	1	188	197,956	24,541
Other	1	56	410,059	45,248
Total	5	758	1,529,211	$	220,415