CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 89,035	$ 70,484
Adjustments to net income:
Depreciation and amortization	121,097	107,933
Amortization of share-based compensation	2,753	2,605
Non-cash revenue adjustments	(1,343)	(3,099)
Amortization of net premiums on mortgages payable	(630)	(1,101)
Amortization of deferred financing costs	2,390	2,200
(Gain) loss on interest rate swaps	(1,330)	5,778
Gain on sales of real estate	(10,532)	(2,289)
Provisions for impairment on real estate	5,433	1,923
Change in assets and liabilities
Accounts receivable and other assets	139	5,081
Accounts payable, accrued expenses and other liabilities	6,119	(53,225)
Net cash provided by operating activities	213,131	136,290
CASH FLOWS FROM INVESTING ACTIVITIES
Investment in real estate	(374,573)	(313,169)
Improvements to real estate, including leasing costs	(3,749)	(902)
Proceeds from sale of real estate	31,232	11,038
Collection of loans receivable	30	12,428
Restricted escrow deposits for Section 1031 tax-deferred exchanges and pending acquisitions	(18,252)	(4,088)
Net cash used in investing activities	(365,312)	(294,693)
CASH FLOWS FROM FINANCING ACTIVITIES
Cash distributions to common stockholders	(162,506)	(147,345)
Cash dividends to preferred stockholders	(6,168)	(6,770)
Borrowings on line of credit	79,000	1,209,000
Payments on line of credit	(1,199,000)	(794,000)
Proceeds from notes and bonds payable issued	711,812
Principal payments on mortgages payable	(2,120)	(164,339)
Proceeds from common stock offerings, net	705,012
Proceeds from dividend reinvestment and stock purchase plan	56,991	3,512
Procceds from At-the-Market (ATM) program		30,547
Distributions to noncontrolling interests	(631)	(382)
Debt issuance costs	(6,614)
Other items, including shares withheld upon vesting	(5,417)	(3,419)
Net cash provided by financing activities	170,359	126,804
Net increase (decrease) in cash and cash equivalents	18,178	(31,599)
Cash and cash equivalents, beginning of period	9,420	40,294
Cash and cash equivalents, end of period	$ 27,598	$ 8,695