Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Real estate assets:
Operating properties, net of accumulated depreciation of $347,681 and $275,977 in 2018 and 2017, respectively	$ 3,513,203	$ 3,332,619
Projects under development	115,158	280,982
Land	4,221	4,221
Total properties	3,632,582	3,617,822
Cash and cash equivalents	110,232	148,929
Restricted cash	328	56,816
Notes and accounts receivable, net of allowance for doubtful accounts of $362 and $535 in 2018 and 2017, respectively	12,364	14,420
Deferred rents receivable	71,576	58,158
Investment in unconsolidated joint ventures	143,201	101,414
Intangible assets, net	164,753	186,206
Other assets	31,216	20,854
Total assets	4,166,252	4,204,619
Liabilities:
Notes payable	1,089,264	1,093,228
Accounts payable and accrued expenses	98,562	137,909
Deferred income	39,884	37,383
Intangible liabilities, net of accumulated amortization of $36,058 and $28,960 in 2018 and 2017, respectively	63,356	70,454
Other liabilities	42,842	40,534
Total liabilities	1,333,908	1,379,508
Commitments and contingencies
Stockholders' investment:
Preferred stock, $1 par value, 20,000,000 shares authorized, 6,867,357 shares issued and outstanding in 2018 and 2017	6,867	6,867
Common stock, $1 par value, 700,000,000 shares authorized, 430,733,698 and 430,349,620 shares issued in 2018 and 2017, respectively	430,734	430,350
Additional paid-in capital	3,605,047	3,604,776
Treasury stock at cost, 10,339,735 and 10,329,082 shares in 2018 and 2017, respectively	(148,473)	(148,373)
Distributions in excess of cumulative net income	(1,116,640)	(1,121,647)
Total stockholders' investment	2,777,535	2,771,973
Nonredeemable noncontrolling interests	54,809	53,138
Total equity	2,832,344	2,825,111
Total liabilities and equity	$ 4,166,252	$ 4,204,619