Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands		Jun. 30, 2021	Dec. 31, 2020
Assets:
Real estate, net of accumulated depreciation and amortization of $2,784,417 and $2,717,114, respectively		$ 9,263,542	$ 9,346,041
Cash and cash equivalents		230,062	293,188
Marketable securities		792,136	706,954
Accounts and notes receivable, net		200,121	219,248
Operating lease right-of-use assets, net		99,924	102,369
Other assets		230,646	233,192
Total assets	[1]	11,558,922	11,614,498
Liabilities:
Notes payable, net		5,047,529	5,044,208
Mortgages payable, net		167,976	311,272
Dividends payable		5,366	5,366
Operating lease liabilities		94,492	96,619
Other liabilities		455,560	470,995
Total liabilities	[2]	5,770,923	5,928,460
Redeemable noncontrolling interests		15,784	15,784
Commitments and Contingencies
Stockholders' equity:
Preferred stock, $1.00 par value, authorized 7,054,000 shares; Issued and outstanding (in series) 19,580 shares; Aggregate liquidation preference $489,500		20	20
Common stock, $.01 par value, authorized 750,000,000 shares; Issued and outstanding 433,516,714 and 432,518,743 shares, respectively		4,335	4,325
Paid-in capital		5,771,179	5,766,511
Cumulative distributions in excess of net income		(68,265)	(162,812)
Total stockholders' equity		5,707,269	5,608,044
Noncontrolling interests		64,946	62,210
Total equity		5,772,215	5,670,254
Total liabilities and equity		11,558,922	11,614,498
Real Estate Under Development [Member]
Assets:
Real estate under development		5,672	5,672
Investments in and Advances to Real Estate Joint Ventures [Member]
Assets:
Investments in and advances to real estate joint ventures		595,283	590,694
Other Real Estate Investments [Member]
Assets:
Other real estate investments		$ 141,536	$ 117,140

[1] Includes restricted assets of consolidated variable interest entities ("VIEs") at June 30, 2021 and December 31, 2020 of $101,807 and $102,482, respectively. See Footnote 11 of the Notes to Condensed Consolidated Financial Statements.

[2] Includes non-recourse liabilities of consolidated VIEs at June 30, 2021 and December 31, 2020 of $60,723 and $62,076, respectively. See Footnote 11 of the Notes to Condensed Consolidated Financial Statements.