Segment Reporting Operating Activity Within Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Operating income (loss)	$ 16,415	$ 20,323	$ 22,995	$ 28,848	$ 29,993	$ 30,384	$ 24,487	$ 28,821	$ 88,581	$ 113,685	$ 79,535
Total segments' profit									223,454	234,761	209,412
Total Retail
Segment Reporting Information [Line Items]
Property revenue									88,280	107,604	105,552
Property expense									(27,374)	(30,633)	(30,078)
Operating income (loss)									60,906	76,971	75,474
Total Office
Segment Reporting Information [Line Items]
Property revenue									177,554	144,683	112,362
Property expense									(47,424)	(42,234)	(33,860)
Operating income (loss)									130,130	102,449	78,502
Total Multifamily
Segment Reporting Information [Line Items]
Property revenue									50,327	51,066	50,627
Property expense									(22,074)	(20,863)	(20,441)
Operating income (loss)									28,253	30,203	30,186
Total Mixed-Use
Segment Reporting Information [Line Items]
Property revenue									28,412	63,388	62,326
Property expense									(24,247)	(38,250)	(37,076)
Operating income (loss)									$ 4,165	$ 25,138	$ 25,250