CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Real estate:
Buildings and improvements	$ 11,008,771	$ 11,692,654
Development costs and construction in progress	430,007	400,619
Land	1,772,174	1,881,487
Accumulated depreciation and amortization	(2,577,248)	(2,648,930)
Net real estate	10,633,704	11,325,830
Net investment in direct financing leases	712,540	752,589
Loans receivable, net	788,486	807,954
Investments in and advances to unconsolidated joint ventures	827,202	571,491
Accounts receivable, net of allowance of $3,941 and $4,459, respectively	31,500	45,116
Cash and cash equivalents	764,114	94,730
Restricted cash	60,806	42,260
Intangible assets, net	432,109	479,805
Assets held for sale, net		927,866
Other assets, net	605,407	711,624
Total assets	14,855,868	15,759,265
LIABILITIES AND EQUITY
Bank line of credit	492,421	899,718
Term loans	274,103	440,062
Senior unsecured notes	7,136,336	7,133,538
Mortgage debt	147,329	623,792
Other debt	91,263	92,385
Intangible liabilities, net	54,472	58,145
Liabilities of assets held for sale, net		3,776
Accounts payable and accrued liabilities	344,908	417,360
Deferred revenue	141,561	149,181
Total liabilities	8,682,393	9,817,957
Commitments and contingencies
Common stock, $1.00 par value: 750,000,000 shares authorized; 468,446,208 and 468,081,489 shares issued and outstanding, respectively	468,446	468,081
Additional paid-in capital	8,203,778	8,198,890
Cumulative dividends in excess of earnings	(2,802,218)	(3,089,734)
Accumulated other comprehensive loss	(28,658)	(29,642)
Total stockholders' equity	5,841,348	5,547,595
Joint venture partners	154,161	214,377
Non-managing member unitholders	177,966	179,336
Total noncontrolling interests	332,127	393,713
Total equity	6,173,475	5,941,308
Total liabilities and equity	$ 14,855,868	$ 15,759,265