REAL ESTATE

The Company owns and operates industrial and office properties. The carrying value of these operating properties by type as of December 31, 2017 and 2016 is as follows (in thousands):



	Land		Building
	and Land		and				Accumulated
	Improvements		Improvements		Total		Depreciation
2017
Industrial properties	$	1,001,454	$	3,873,830	$	4,875,284	$	814,301
Office properties	152,226		569,753		721,979		126,312

2017 Total	$	1,153,680	$	4,443,583	$	5,597,263	$	940,613

2016
Industrial properties	$	914,428	$	3,725,331	$	4,639,759	$	719,658
Office properties	145,637		572,681		718,318		127,448

2016 Total	$	1,060,065	$	4,298,012	$	5,358,077	$	847,106

Depreciation expense was $148.9 million, $166.8 million and $181.0 million for the years ended December 31, 2017, 2016 and 2015, respectively.

Information on the operating properties the Company sold during the years ended December 31, 2017, 2016 and 2015 is as follows:

2017 Sales



Reportable Segment	Number of Buildings	Acres of Developable Land (unaudited)	Leaseable Square Feet (unaudited)	Gross Proceeds (in thousands)
Chicago/Minneapolis	3	—	136,110	$	8,917
Florida	—	16	—	13,256
Houston	1	42	206,808	36,145
Lehigh/Central PA	2	44	1,683,876	249,045
Southeastern PA	4	3	313,410	56,156
Other	—	8	—	3,739
Total	10	113	2,340,204	$	367,258

2016 Sales



Reportable Segment	Number of Buildings	Acres of Developable Land (unaudited)	Leaseable Square Feet (unaudited)	Gross Proceeds (in thousands)
Chicago/Minneapolis	24	5	2,037,275	$	199,825
Florida	51	12	3,509,641	505,828
Lehigh/Central PA	1	—	120,777	11,200
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
Chicago/Minneapolis	2	—	222,642	25,700
Florida	4	—	874,125	55,425
Southeastern PA	46	20	2,724,489	316,583
Other	7	—	569,618	37,371
Total	81	23	5,710,173	$	545,133

Included in the sales for the year ended December 31, 2015 are 22 properties and three acres of land in the Carolinas/Richmond segment that the Company sold for $110.3 million to a firm in which the brother of David L. Lingerfelt, a member of the Company's Board of Trustees, has an equity interest.

During the year ended December 31, 2015, the Company completed a portfolio sale consisting of 41 properties and 20 acres of land in the Southeastern PA segment. As of December 31, 2016, the Company had deferred gain recognition related to this sale in the amount of $14.3 million which is recorded in other liabilities on the accompanying consolidated balance sheets. During the year ended December 31, 2017, the contingency related to the portfolio sale was settled and the Company recognized the deferred gain in the accompanying statements of comprehensive income.

Information on the operating properties and land parcels the Company acquired during the years ended December 31, 2017, 2016 and 2015 is as follows:

2017 Acquisitions



Reportable Segment	Number of Buildings	Acres of Developable Land (unaudited)	Leaseable Square Feet (unaudited)	Purchase Price
				(in thousands)
Carolinas/Richmond	—	11	—	$	1,242
Lehigh/Central PA	—	95	—	17,798
United Kingdom	—	35	—	12,550
Other	8	113	1,861,879	264,808
Total	8	254	1,861,879	$	296,398

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/Minneapolis	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
Chicago/Minneapolis	1	188	197,956	24,541
Houston	3	139	921,196	86,497
Lehigh/Central PA	—	281	—	62,402
Other	1	56	410,059	45,248
Total	5	758	1,529,211	$	220,415

Subsequent to December 31, 2017, the Company closed on the acquisition of a 400,000 square foot property in its Southern California segment for a Total Investment of $92.7 million.