Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Assets
Land	$ 962,507	$ 989,247
Buildings and improvements	5,910,347	5,911,432
Real estate assets, at cost, total	6,872,854	6,900,679
Accumulated depreciation	(1,829,563)	(1,780,694)
Net operating real estate assets	5,043,291	5,119,985
Properties under development, including land	425,452	486,918
Investments in joint ventures	30,046	33,698
Discontinued operations held for sale, including land	0	239,063
Total real estate assets	5,498,789	5,879,664
Short-term Investments	100,000	0
Accounts receivable – affiliates	23,998	25,100
Other assets, net	143,059	116,260
Cash and cash equivalents	313,742	10,617
Restricted cash	8,691	5,971
Total assets	6,088,279	6,037,612
Liabilities
Unsecured notes payable	1,582,655	1,824,930
Secured notes payable	897,971	899,757
Accounts payable and accrued expenses	143,193	133,353
Accrued real estate taxes	66,079	45,223
Distributions payable	82,861	64,275
Other liabilities	122,270	97,814
Total liabilities	2,895,029	3,065,352
Commitments and contingencies (Note 10)
Non-qualified deferred compensation share awards	72,222	79,364
Equity
Common shares of beneficial interest; $0.01 par value per share; 175,000 shares authorized; 100,695 and 100,636 issued; 97,805 and 97,571 outstanding at September 30, 2016 and December 31, 2015, respectively	978	976
Additional paid-in capital	3,675,806	3,662,864
Distributions in excess of net income attributable to common shareholders	(261,324)	(458,577)
Treasury shares, at cost (10,337 and 10,703 common shares at September 30, 2016 and December 31, 2015, respectively)	(373,597)	(386,793)
Accumulated other comprehensive loss	(1,816)	(1,913)
Total common equity	3,040,047	2,816,557
Non-controlling interests	80,981	76,339
Total equity	3,121,028	2,892,896
Total liabilities and equity	$ 6,088,279	$ 6,037,612