Investments in and Advances to Joint Ventures - Revenues Earned By the Company from Unconsolidated Joint Ventures and Interest Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue from contracts:
Total revenue from contracts with customers	$ 8,620	$ 14,398	$ 23,367	$ 30,983
Other:
Interest income	3,500	4,200	6,900	8,400
Other	400	800	1,200	1,500
Other, Total	3,900	5,000	8,100	9,900
Revenue and other income	7,000	10,900	18,300	22,500
Asset and Property Management Fees [Member]
Revenue from contracts:
Total revenue from contracts with customers	7,551	11,110	16,876	22,641
Unconsolidated Joint Ventures [Member]
Revenue from contracts:
Total revenue from contracts with customers	3,100	5,900	10,200	12,600
Unconsolidated Joint Ventures [Member] | Asset and Property Management Fees [Member]
Revenue from contracts:
Total revenue from contracts with customers	2,700	4,800	7,200	10,100
Unconsolidated Joint Ventures [Member] | Development Fees, Leasing Commissions and Other [Member]
Revenue from contracts:
Total revenue from contracts with customers	$ 400	$ 1,100	$ 3,000	$ 2,500