Real Estate (Tables)

6 Months Ended

Jun. 30, 2012

Real Estate [Abstract]

Real estate assets

	June 30,		December 31,
	2012		2011
Industrial operating properties (1):
Improved land	$	5,525,407	$	4,813,145
Buildings and improvements		17,916,987		16,739,403
Development portfolio, including cost of land (2)		656,561		860,531
Land (3)		1,881,062		1,984,233
Other real estate investments (4)		442,280		390,225
Total investments in real estate properties		26,422,297		24,787,537
Less accumulated depreciation		2,256,101		2,157,907
Net investments in properties	$	24,166,196	$	22,629,630

(1) At June 30, 2012 and December 31, 2011, we had 1,927 and 1,797 industrial properties consisting of 328.0 million square feet and 291.1 million square feet, respectively. Included at June 30, 2012 were 180 properties totaling $2.1 billion that were acquired in connection with the Q1 Venture Acquisitions.

(2) At June 30, 2012, the development portfolio consisted of 30 properties aggregating 10.6 million square feet. At December 31, 2011, we had 30 properties aggregating 9.5 million square feet in the development portfolio. Our total expected investment upon completion of the properties currently in the development portfolio at June 30, 2012 was $1.0 billion, including land, development and leasing costs.

(3) Land consisted of 10,508 acres and 10,723 acres at June 30, 2012 and December 31, 2011, respectively, and included land parcels that we may develop or sell depending on market conditions and other factors.

(4) Included in other investments are: (i) certain non-industrial real estate; (ii) our corporate office buildings; (iii) land ground leased to third parties; (iv) certain infrastructure costs related to projects we are developing on behalf of others; (v) costs related to future development projects, including purchase options on land; and (vi) earnest money deposits associated with potential acquisitions.