CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 180,012	$ 170,294
Adjustments to net income:
Depreciation and amortization	265,102	244,186
Amortization of share-based compensation	8,657	7,215
Non-cash revenue adjustments	(4,029)	(1,564)
Amortization of net premiums on mortgages payable	(813)	(1,240)
Amortization of deferred financing costs	3,469	4,684
Gain on interest rate swaps	(2,799)	(859)
Gain on sales of real estate	(11,005)	(13,371)
Provisions for impairment on real estate	18,172	7,706
Change in assets and liabilities
Accounts receivable and other assets	2,785	3,168
Accounts payable, accrued expenses and other liabilities	17,718	41,620
Net cash provided by operating activities	477,269	461,839
CASH FLOWS FROM INVESTING ACTIVITIES
Investment in real estate	(829,818)	(696,116)
Improvements to real estate, including leasing costs	(17,017)	(9,232)
Proceeds from sales of real estate	47,526	44,005
Insurance proceeds received	3,836	0
Collection of loans receivable	5,267	61
Net cash used in investing activities	(790,206)	(661,282)
CASH FLOWS FROM FINANCING ACTIVITIES
Cash distributions to common stockholders	(373,044)	(335,380)
Cash dividends to preferred stockholders	0	(6,168)
Borrowings on line of credit	1,140,000	772,000
Payments on line of credit	(716,000)	(1,244,000)
Principal payment on term loan	(125,866)	0
Proceeds from notes and bonds payable issued	497,500	711,812
Principal payment on notes payable	(350,000)	0
Principal payments on mortgages payable	(13,447)	(86,515)
Redemption of preferred stock	0	(408,750)
Proceeds from common stock offerings, net	0	704,938
Proceeds from dividend reinvestment and stock purchase plan	4,806	59,649
Proceeds from At-the-Market (ATM) program	297,983	52,442
Distributions to noncontrolling interests	(758)	(887)
Debt issuance costs	(4,436)	(6,663)
Other items, including shares withheld upon vesting	(11,143)	(6,305)
Net cash provided by financing activities	345,595	206,173
Net increase in cash, cash equivalents and restricted cash	32,658	6,730
Cash, cash equivalents and restricted cash, beginning of period	12,142	15,681
Cash, cash equivalents and restricted cash, end of period	$ 44,800	$ 22,411