Business Segments - Schedule of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Real estate rental operations:
Revenue	$ 57,052			$ 56,910			$ 174,943	$ 169,100
Income from real estate	42,413			43,063			131,221	127,775
Interest expense, net and amortization of deferred debt costs	(10,325)			(10,974)			(32,185)	(33,568)
Depreciation and amortization of deferred leasing costs	(12,018)			(11,256)			(35,185)	(33,956)
General and administrative	(4,742)			(4,141)			(14,696)	(13,208)
Change in fair value of derivatives	0			10			0	(2)
Gain on sale of property	0			0			0	509
Net Income	15,328	$ 16,750	$ 17,077	16,702	$ 15,901	$ 14,947	49,155	47,550
Capital investment	36,456			59,306			105,055	96,299
Total assets	1,646,764			1,506,138			1,646,764	1,506,138	$ 1,527,489
Operating Segments | Shopping Centers
Real estate rental operations:
Revenue	41,313			41,091			126,730	122,770
Income from real estate	32,339			32,517			99,516	96,839
Interest expense, net and amortization of deferred debt costs	0			0			0	0
Depreciation and amortization of deferred leasing costs	(7,260)			(7,249)			(21,917)	(21,880)
General and administrative	0			0			0	0
Change in fair value of derivatives				0				0
Gain on sale of property								509
Net Income	25,079			25,268			77,599	75,468
Capital investment	9,166			15,145			22,746	22,288
Total assets	985,244			982,038			985,244	982,038
Operating Segments | Mixed-Use Properties
Real estate rental operations:
Revenue	15,739			15,819			48,213	46,330
Income from real estate	10,074			10,546			31,705	30,936
Interest expense, net and amortization of deferred debt costs	0			0			0	0
Depreciation and amortization of deferred leasing costs	(4,758)			(4,007)			(13,268)	(12,076)
General and administrative	0			0			0	0
Change in fair value of derivatives				0				0
Gain on sale of property								0
Net Income	5,316			6,539			18,437	18,860
Capital investment	27,290			44,161			82,309	74,011
Total assets	609,560			514,480			609,560	514,480
Corporate and Other
Real estate rental operations:
Revenue	0			0			0	0
Income from real estate	0			0			0	0
Interest expense, net and amortization of deferred debt costs	(10,325)			(10,974)			(32,185)	(33,568)
Depreciation and amortization of deferred leasing costs	0			0			0	0
General and administrative	(4,742)			(4,141)			(14,696)	(13,208)
Change in fair value of derivatives				10				(2)
Gain on sale of property								0
Net Income	(15,067)			(15,105)			(46,881)	(46,778)
Capital investment	0			0			0	0
Total assets	51,960			9,620			51,960	9,620
Real Estate
Real estate rental operations:
Expenses	(14,639)			(13,847)			(43,722)	(41,325)
Real Estate | Operating Segments | Shopping Centers
Real estate rental operations:
Expenses	(8,974)			(8,574)			(27,214)	(25,931)
Real Estate | Operating Segments | Mixed-Use Properties
Real estate rental operations:
Expenses	(5,665)			(5,273)			(16,508)	(15,394)
Real Estate | Corporate and Other
Real estate rental operations:
Expenses	$ 0			$ 0			$ 0	$ 0