CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 83,315	$ 89,035
Adjustments to net income:
Depreciation and amortization	131,103	121,097
Amortization of share-based compensation	3,662	2,753
Non-cash revenue adjustments	(1,544)	(1,343)
Amortization of net premiums on mortgages payable	(459)	(630)
Amortization of deferred financing costs	1,652	2,390
Gain on interest rate swaps	(2,007)	(1,330)
Gain on sales of real estate	(3,218)	(10,532)
Provisions for impairment on real estate	14,221	5,433
Change in assets and liabilities
Accounts receivable and other assets	(2,473)	3,027
Accounts payable, accrued expenses and other liabilities	(10,723)	6,119
Net cash provided by operating activities	213,529	216,019
CASH FLOWS FROM INVESTING ACTIVITIES
Investment in real estate	(498,448)	(374,573)
Improvements to real estate, including leasing costs	(8,940)	(3,749)
Proceeds from sales of real estate	13,779	31,232
Insurance proceeds received	1,184
Collection of loans receivable	32	30
Non-refundable escrow deposits for pending acquisitions	(442)
Net cash used in investing activities	(492,835)	(347,060)
CASH FLOWS FROM FINANCING ACTIVITIES
Cash distributions to common stockholders	(185,556)	(162,506)
Cash dividends to preferred stockholders		(6,168)
Borrowings on line of credit	1,058,000	79,000
Payments on line of credit	(86,000)	(1,199,000)
Principal payment on term loan	(125,866)
Proceeds from notes and bonds payable issued		711,812
Principal payment on notes payable	(350,000)
Principal payments on mortgages payable	(12,323)	(2,120)
Proceeds from common stock offerings, net		705,012
Proceeds from dividend reinvestment and stock purchase plan	2,346	56,991
Distributions to noncontrolling interests	(313)	(631)
Debt issuance costs		(6,614)
Other items, including shares withheld upon vesting	(6,542)	(5,417)
Net cash provided by financing activities	293,746	170,359
Net increase in cash, cash equivalents and restricted cash	14,440	39,318
Cash, cash equivalents and restricted cash, beginning of period	12,142	15,681
Cash, cash equivalents and restricted cash, end of period	$ 26,582	$ 54,999