Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets
Land	$ 1,053,578	$ 1,021,031
Buildings and improvements	6,494,229	6,269,481
Real estate assets, at cost, total	7,547,807	7,290,512
Accumulated depreciation	(2,185,452)	(2,118,839)
Net operating real estate assets	5,362,355	5,171,673
Properties under development, including land	399,903	377,231
Investments in joint ventures	26,863	27,237
Total real estate assets	5,789,121	5,576,141
Accounts receivable – affiliates	23,397	24,038
Other assets, net	199,420	195,764
Cash and cash equivalents	101,401	368,492
Restricted cash	15,036	9,313
Total assets	6,128,375	6,173,748
Liabilities
Unsecured notes payable	1,339,142	1,338,628
Secured notes payable	865,798	865,970
Accounts payable and accrued expenses	123,706	128,313
Accrued real estate taxes	29,061	51,383
Distributions payable	75,083	72,943
Other liabilities	157,002	154,567
Total liabilities	2,589,792	2,611,804
Commitments and contingencies (Note 12)
Non-qualified deferred compensation share awards	76,174	77,230
Equity
Common shares of beneficial interest; $0.01 par value per share; 175,000 shares authorized; 105,493 and 105,489 issued; 102,640 and 102,769 outstanding at March 31, 2018 and December 31, 2017, respectively	1,026	1,028
Additional paid-in capital	4,132,056	4,137,161
Distributions in excess of net income attributable to common shareholders	(396,596)	(368,703)
Treasury shares, at cost (9,865 and 10,073 common shares at March 31, 2018 and December 31, 2017, respectively)	(356,687)	(364,066)
Accumulated other comprehensive income (loss)	3,579	(57)
Total common equity	3,383,378	3,405,363
Non-controlling interests	79,031	79,351
Total equity	3,462,409	3,484,714
Total liabilities and equity	$ 6,128,375	$ 6,173,748