CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Real estate:
Buildings and improvements	$ 11,532,338	$ 11,239,732
Development costs and construction in progress	344,948	447,976
Land	1,808,210	1,785,865
Accumulated depreciation and amortization	(2,826,325)	(2,741,695)
Net real estate	10,859,171	10,731,878
Net investment in direct financing leases	713,463	714,352
Loans receivable, net	47,012	313,326
Investments in and advances to unconsolidated joint ventures	863,775	800,840
Accounts receivable, net of allowance of $4,516 and $4,425, respectively	51,468	40,733
Cash and cash equivalents	86,021	55,306
Restricted cash	31,947	26,897
Intangible assets, net	395,298	410,082
Assets held for sale, net	436,155	417,014
Other assets, net	583,261	578,033
Total assets	14,067,571	14,088,461
LIABILITIES AND EQUITY
Bank line of credit	1,092,357	1,017,076
Term loan	236,878	228,288
Senior unsecured notes	6,398,976	6,396,451
Mortgage debt	143,524	144,486
Other debt	93,856	94,165
Intangible liabilities, net	52,576	52,579
Liabilities of assets held for sale, net	8,564	14,031
Accounts payable and accrued liabilities	391,942	401,738
Deferred revenue	167,975	144,709
Total liabilities	8,586,648	8,493,523
Commitments and contingencies
Common stock, $1.00 par value: 750,000,000 shares authorized; 469,725,220 and 469,435,678 shares issued and outstanding, respectively	469,725	469,436
Additional paid-in capital	8,183,166	8,226,113
Cumulative dividends in excess of earnings	(3,425,293)	(3,370,520)
Accumulated other comprehensive income (loss)	(21,307)	(24,024)
Total stockholders' equity	5,206,291	5,301,005
Joint venture partners	97,744	117,045
Non-managing member unitholders	176,888	176,888
Total noncontrolling interests	274,632	293,933
Total equity	5,480,923	5,594,938
Total liabilities and equity	$ 14,067,571	$ 14,088,461