Business Segments (Detail) - USD ($) $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenue	$ 54,201	$ 53,233	$ 52,710	$ 56,926		$ 52,376	$ 51,711	$ 52,088	$ 52,902	$ 217,070	$ 209,077	$ 207,092
Expenses										(53,701)	(51,143)	(49,513)
Income from real estate										163,369	157,934	157,579
Interest expense and amortization of deferred debt costs										(45,683)	(45,165)	(46,034)
General and administrative										(17,496)	(16,353)	(16,961)
Subtotal										100,190	96,416	94,584
Depreciation and amortization of deferred leasing costs										(44,417)	(43,270)	(41,203)
Acquisition related costs										(60)	(84)	(949)
Predevelopment expenses										0	(132)	(503)
Change in fair value of derivatives										(6)	(10)	(10)
Gain on sale of property	1,013	$ 0	$ 0	$ 0	$ 0	$ 0	$ 11	$ 0		1,013	11	6,069
Net income (loss)										56,720	52,931	57,988
Capital investment										91,045	69,619	90,268
Total assets	1,343,025				1,295,408				1,257,113	1,343,025	1,295,408	1,257,113
Operating Segments | Shopping Centers
Segment Reporting Information [Line Items]
Revenue										160,179	156,110	154,385
Expenses										(34,931)	(33,877)	(33,781)
Income from real estate										125,248	122,233	120,604
Interest expense and amortization of deferred debt costs										0	0	0
General and administrative										0	0	0
Subtotal										125,248	122,233	120,604
Depreciation and amortization of deferred leasing costs										(29,964)	(30,171)	(28,082)
Acquisition related costs										(60)	(84)	(949)
Predevelopment expenses											(57)	0
Change in fair value of derivatives										0	0	0
Gain on sale of property										0	11	6,069
Net income (loss)										95,224	91,932	97,642
Capital investment										64,044	17,159	66,508
Total assets	976,545				931,256				939,267	976,545	931,256	939,267
Operating Segments | Mixed-Use Properties
Segment Reporting Information [Line Items]
Revenue										56,840	52,916	52,632
Expenses										(18,770)	(17,266)	(15,732)
Income from real estate										38,070	35,650	36,900
Interest expense and amortization of deferred debt costs										0	0	0
General and administrative										0	0	0
Subtotal										38,070	35,650	36,900
Depreciation and amortization of deferred leasing costs										(14,453)	(13,099)	(13,121)
Acquisition related costs										0	0	0
Predevelopment expenses											(75)	(503)
Change in fair value of derivatives										0	0	0
Gain on sale of property										1,013	0	0
Net income (loss)										24,630	22,476	23,276
Capital investment										27,001	52,460	23,760
Total assets	358,419				354,254				305,579	358,419	354,254	305,579
Corporate
Segment Reporting Information [Line Items]
Revenue										51	51	75
Expenses										0	0	0
Income from real estate										51	51	75
Interest expense and amortization of deferred debt costs										(45,683)	(45,165)	(46,034)
General and administrative										(17,496)	(16,353)	(16,961)
Subtotal										(63,128)	(61,467)	(62,920)
Depreciation and amortization of deferred leasing costs										0	0	0
Acquisition related costs										0	0	0
Predevelopment expenses											0	0
Change in fair value of derivatives										(6)	(10)	(10)
Gain on sale of property										0	0	0
Net income (loss)										(63,134)	(61,477)	(62,930)
Capital investment										0	0	0
Total assets	$ 8,061				$ 9,898				$ 12,267	$ 8,061	$ 9,898	$ 12,267