CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 133,931	$ 120,235
Adjustments to net income:
Depreciation and amortization	199,138	182,864
Income from discontinued operations		(3,097)
Amortization of share-based compensation	5,362	5,449
Non-cash rental adjustments	(4,939)	(3,706)
Amortization of net premiums on mortgages payable	(3,824)	(5,394)
Amortization of deferred financing costs	6,509	5,267
Gain on sale of real estate	(10,893)	(3,236)
Provisions for impairment on real estate	5,317	2,182
Cash provided by discontinued operations		1,310
Change in assets and liabilities
Accounts receivable and other assets	1,778	12,745
Accounts payable, accrued expenses and other liabilities	(10,669)	(15,843)
Net cash provided by operating activities	321,710	298,776
CASH FLOWS FROM INVESTING ACTIVITIES
Investment in real estate	(924,541)	(899,405)
Improvements to real estate, including leasing costs	(2,470)	(2,734)
Proceeds from sales of real estate:
Continuing operations	30,455	12,805
Discontinued operations		6,918
olCollection of loans receivable		350
Restricted escrow deposits for Section 1031 tax-deferred exchanges and pending acquisitions	21,313	(5,280)
Net cash used in investing activities	(875,243)	(887,346)
CASH FLOWS FROM FINANCING ACTIVITIES
Cash distributions to common stockholders	(258,277)	(234,643)
Cash dividends to preferred stockholders	(13,540)	(20,965)
Borrowings on line of credit	957,000	1,054,121
Payments on line of credit	(750,000)	(1,111,321)
Proceeds from notes and bonds payable issued		349,846
Principal payments on mortgages payable	(79,291)	(21,901)
Proceeds from term loans	250,000
Proceeds from common stock offerings, net	276,430	528,627
Redemption of preferred units	(6,750)
Distributions to noncontrolling interests	(848)	(929)
Debt issuance costs	(10,204)	(3,243)
Proceeds from dividend reinvestment and stock purchase plan, net	208,033	54,204
Other items, including shares withheld upon vesting	(4,131)	(6,575)
Net cash provided by financing activities	568,422	587,221
Net increase (decrease) in cash and cash equivalents	14,889	(1,349)
Cash and cash equivalents, beginning of period	3,852	10,257
Cash and cash equivalents, end of period	$ 18,741	$ 8,908