Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Real estate assets:
Operating properties, net of accumulated depreciation of $311,238 and $275,977 in 2018 and 2017, respectively	$ 3,528,617	$ 3,332,619
Projects under development	81,964	280,982
Land	4,221	4,221
Total properties	3,614,802	3,617,822
Cash and cash equivalents	108,152	148,929
Restricted cash	1,185	56,816
Notes and accounts receivable, net of allowance for doubtful accounts of $298 and $535 in 2018 and 2017, respectively	16,668	14,420
Deferred rents receivable	65,995	58,158
Investment in unconsolidated joint ventures	145,465	101,414
Intangible assets, net	175,159	186,206
Other assets	31,884	20,854
Total assets	4,159,310	4,204,619
Liabilities:
Notes payable	1,091,258	1,093,228
Accounts payable and accrued expenses	87,964	137,909
Deferred income	37,895	37,383
Intangible liabilities, net of accumulated amortization of $32,503 and $28,960 in 2018 and 2017, respectively	66,911	70,454
Other liabilities	39,367	40,534
Total liabilities	1,323,395	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, 430,572,693 and 430,349,620 shares issued in 2018 and 2017, respectively	430,573	430,350
Additional paid-in capital	3,604,336	3,604,776
Treasury stock at cost, 10,329,082 shares in 2018 and 2017	(148,373)	(148,373)
Distributions in excess of cumulative net income	(1,110,590)	(1,121,647)
Total stockholders' investment	2,782,813	2,771,973
Nonredeemable noncontrolling interests	53,102	53,138
Total equity	2,835,915	2,825,111
Total liabilities and equity	$ 4,159,310	$ 4,204,619