CONSOLIDATED BALANCE SHEETS - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Real estate:
Buildings and improvements	$ 11,692,654,000	$ 12,007,071,000
Development costs and construction in progress	400,619,000	388,576,000
Land	1,881,487,000	1,934,610,000
Accumulated depreciation and amortization	(2,648,930,000)	(2,476,015,000)
Net real estate	11,325,830,000	11,854,242,000
Net investment in direct financing leases	752,589,000	750,693,000
Loans receivable, net	807,954,000	768,743,000
Investments in and advances to unconsolidated joint ventures	571,491,000	605,244,000
Accounts receivable, net of allowance of $4,459 and $3,261, respectively	45,116,000	48,929,000
Cash and cash equivalents of continuing operations, end of year	94,730,000	340,442,000
Restricted cash	42,260,000	46,090,000
Intangible assets, net	479,805,000	586,657,000
Assets held for sale and discontinued operations, net	927,866,000	5,654,326,000
Other assets, net	711,624,000	794,483,000
Total assets	15,759,265,000	21,449,849,000
LIABILITIES AND EQUITY
Bank line of credit	899,718,000	397,432,000
Term loans	440,062,000	524,807,000
Senior unsecured notes	7,133,538,000	9,120,107,000
Mortgage debt	623,792,000	932,212,000
Other debt	92,385,000	94,445,000
Intangible liabilities, net	58,145,000	56,147,000
Liabilities of assets held for sale and discontinued operations, net	3,776,000	25,266,000
Accounts payable and accrued liabilities	417,360,000	430,786,000
Deferred revenue	149,181,000	122,330,000
Total liabilities	9,817,957,000	11,703,532,000
Commitments and contingencies
Common stock, $1.00 par value: 750,000,000 shares authorized; 468,081,489 and 465,488,492 shares issued and outstanding, respectively	468,081,000	465,488,000
Additional paid-in capital	8,198,890,000	11,647,039,000
Cumulative dividends in excess of earnings	(3,089,734,000)	(2,738,414,000)
Accumulated other comprehensive loss	(29,642,000)	(30,470,000)
Total stockholders' equity	5,547,595,000	9,343,643,000
Joint venture partners	214,377,000	217,066,000
Non-managing member unitholders	179,336,000	185,608,000
Total noncontrolling interests	393,713,000	402,674,000
Total equity	5,941,308,000	9,746,317,000
Total liabilities and equity	$ 15,759,265,000	$ 21,449,849,000