Investments in and Advances to Joint Ventures - Service Fees and Income Earned by Company's Unconsolidated Joint Ventures and Interest Income (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue from contracts with customers:
Asset and property management fees	$ 5,596	$ 6,173
Total revenue from contracts with customers	7,543	8,624
Other:
Other	612	883
Total fee and other income	13,019	14,017
Unconsolidated Joint Ventures [Member]
Revenue from contracts with customers:
Asset and property management fees	5,600	6,200
Development fees and leasing commissions	1,900	2,400
Total revenue from contracts with customers	7,500	8,600
Other:
Interest income	5,000	7,500
Other	500	700
Total fee and other income	$ 13,000	$ 16,800