Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets
Land	$ 1,098,526	$ 1,021,031
Buildings and improvements	6,935,971	6,269,481
Real estate assets, at cost, total	8,034,497	7,290,512
Accumulated depreciation	(2,403,149)	(2,118,839)
Net operating real estate assets	5,631,348	5,171,673
Properties under development, including land	293,978	377,231
Investments in joint ventures	22,283	27,237
Total real estate assets	5,947,609	5,576,141
Accounts receivable – affiliates	22,920	24,038
Other assets, net	205,454	195,764
Cash and cash equivalents	34,378	368,492
Restricted cash	9,225	9,313
Total assets	6,219,586	6,173,748
Liabilities
Unsecured notes payable	1,836,427	1,338,628
Secured notes payable	485,176	865,970
Accounts payable and accrued expenses	146,866	128,313
Accrued real estate taxes	54,358	51,383
Distributions payable	74,982	72,943
Other liabilities	183,999	154,567
Total liabilities	2,781,808	2,611,804
Commitments and contingencies (Note 15)
Non-qualified deferred compensation share awards	52,674	77,230
Equity
Common shares of beneficial interest; $0.01 par value per share; 175,000 shares authorized; 105,503 and 105,489 issued; 103,080 and 102,769 outstanding at December 31, 2018 and 2017, respectively	1,031	1,028
Additional paid-in capital	4,154,763	4,137,161
Distributions in excess of net income attributable to common shareholders	(495,496)	(368,703)
Treasury shares, at cost (9,841 and 10,073 common shares, at December 31, 2018 and 2017, respectively)	(355,804)	(364,066)
Accumulated other comprehensive income (loss)	6,929	(57)
Total common equity	3,311,423	3,405,363
Non-controlling interests	73,681	79,351
Total equity	3,385,104	3,484,714
Total liabilities and equity	$ 6,219,586	$ 6,173,748