Real Estate (Tables)

12 Months Ended

Dec. 31, 2012

Real Estate Assets

Investments in real estate properties are presented at cost, and consist of the following as of December 31 (in thousands):

	2012		2011
Industrial operating properties (1):
Improved land	$	5,317,123	$	4,813,145
Buildings and improvements		17,291,125		16,739,403
Development portfolio, including cost of land (2)		951,643		860,531
Land (3)		1,794,364		1,984,233
Other real estate investments (4)		454,868		390,225
Total investments in real estate properties		25,809,123		24,787,537
Less accumulated depreciation		2,480,660		2,157,907
Net investments in real estate properties	$	23,328,463	$	22,629,630

(1) At December 31, 2012 and 2011, we had 1,853 and 1,797 industrial properties consisting of 316.3 million and 291.1 million square feet, respectively. Included at December 31, 2012 were 183 properties totaling $2.2 billion that were acquired in connection with the Co-Investment Venture Acquisitions.

(2) At December 31, 2012, the development portfolio consisted of 30 properties aggregating 13.2 million square feet under development and 15 properties aggregating 4.8 million square feet of pre-stabilized completed properties. At December 31, 2011, the development portfolio consisted of 26 properties aggregating 7.2 million square feet that were under development and four properties aggregating 2.3 million square feet that were pre-stabilized completed properties.

(3) Land consisted of 10,915 acres at December 31, 2012, and 10,723 acres at 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 were: (i) certain non-industrial real estate; (ii) our corporate office buildings; (iii) land parcels that are ground leased to third parties; (iv) certain infrastructure costs related to projects we are developing on behalf of others; (v) restricted funds that are held in escrow pending the completion of tax-deferred exchange transactions involving operating properties; (vi) costs related to future development projects, including purchase options on land; and (vii) earnest money deposits associated with potential acquisitions.

Future Minimum Rental Payments under Non-Cancelable Operating Leases

Future minimum rental payments under non-cancelable operating leases in effect as of December 31, 2012 were as follows (in thousands):

2013	$	37,680
2014		36,475
2015		34,971
2016		29,569
2017		28,274
Thereafter		384,825
Total	$	551,794

Operating Properties and Leases

At December 31, 2012, minimum lease payments on leases with lease periods greater than one year for space in our operating properties and leases of land subject to ground leases, during each of the years in the five-year period ending December 31, 2017 and thereafter were as follows (in thousands):

2013	$	1,304,476
2014		1,120,418
2015		909,425
2016		702,224
2017		530,208
Thereafter		1,522,733
Total	$	6,089,304