Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income		$ 50,316	$ 64,196	$ 63,059
Adjustments to reconcile net income to net cash provided by operating activities:
Change in fair value of derivatives		0	436	3
Gains on sales of properties		(278)	0	(509)
Depreciation and amortization of deferred leasing costs		51,126	46,333	45,861
Amortization of deferred debt costs		1,570	1,518	1,610
Non cash compensation costs of stock grants and options		1,438	1,859	1,766
Credit losses on operating lease receivables		5,212	1,226	685
(Increase) decrease in accounts receivable and accrued income		(17,818)	339	(336)
Additions to deferred leasing costs		(8,050)	(1,843)	(6,034)
(Increase) decrease in prepaid expenses		(356)	(188)	73
Decrease in other assets		361	894	3,681
Increase in accounts payable, accrued expenses and other liabilities		875	158	225
Increase (decrease) in deferred income		(6,013)	455	255
Net cash provided by operating activities		78,383	115,383	110,339
Cash flows from investing activities:
Acquisitions of real estate investments	[1]	0	0	(40,836)
Additions to real estate investments		(19,484)	(21,891)	(12,883)
Additions to development and redevelopment projects		(37,060)	(113,772)	(76,257)
Proceeds from sale of properties	[2]	376	0	1,326
Net cash used in investing activities		(56,168)	(135,663)	(128,650)
Cash flows from financing activities:
Proceeds from mortgage notes payable		52,100	50,600	54,900
Repayments on mortgage notes payable		(45,654)	(109,235)	(72,572)
Proceeds from term loan facility		0	0	75,000
Proceeds from revolving credit facility		90,000	152,500	102,000
Repayments on revolving credit facility		(73,000)	(112,000)	(116,000)
Proceeds from construction loans payable		35,883	86,868	23,332
Additions to deferred debt costs		(1,206)	(1,010)	(3,233)
Proceeds from the issuance of:
Common stock		8,264	25,039	30,503
Partnership units	[1]	1,677	3,180	5,383
Preferred stock redemption costs		0	0	(12)
Distributions to:
Distributions to preferred stockholders		(11,194)	(12,390)	(12,402)
Common stockholders		(49,383)	(48,568)	(46,306)
Noncontrolling interests		(16,751)	(16,642)	(15,981)
Net cash provided by (used in) financing activities		(9,264)	19,607	21,981
Net increase (decrease) in cash and cash equivalents		12,951	(673)	3,670
Cash and cash equivalents, beginning of year		13,905	14,578	10,908
Cash and cash equivalents, end of year		26,856	13,905	14,578
Supplemental disclosure of cash flow information:
Cash paid for interest		44,990	40,434	43,561
Increase (decrease) in accrued real estate investments and development costs		(11,690)	303	9,663
Series C Cumulative Preferred Stock
Proceeds from the issuance of:
Series C preferred stock redemption		0	(105,000)	(75,000)
Distributions to:
Distributions to preferred stockholders		0	(7,541)	(9,238)
Series D Cumulative Redeemable Preferred Stock
Proceeds from the issuance of:
Preferred stock		0	0	72,369
Distributions to:
Distributions to preferred stockholders		(4,594)	(4,592)	(3,164)
Series E Cumulative Redeemable Preferred Stock
Proceeds from the issuance of:
Preferred stock		0	106,265	0
Distributions to:
Distributions to preferred stockholders		$ (6,600)	$ (257)	0
Ashbrook Marketplace
Supplemental disclosure of cash flow information:
Limited partnership units issued				8,776
Great Eastern Shopping Center
Supplemental disclosure of cash flow information:
Seller financing				1,275
Interest income				$ 51

[1] The 2018 acquisition of real estate and proceeds from the issuance of partnership units each excludes $8,776 in connection with the acquisition of Ashbrook Marketplace in exchange for limited partnership units.

[2] Proceeds from sale of property in 2018 includes $1,275 of seller financing in connection with the sale of the Company's Great Eastern property in 2017, which were received in 2018 plus accrued interest of $51.