Impairment Charges and Reserves - Impairment Charges on Assets or Investments (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Impairment Charges And Impairment Of Joint Venture Investments [Abstract]
Assets marketed for sale	$ 0	$ 5,800	$ 600	$ 5,800
Assets included in the spin-off of RVI	0	14,100	0	62,600
Reserve of preferred equity interests, net	6,400	2,200	12,106	4,537
Total impairment charges	9,200	22,100	15,500	72,900
Undeveloped Land [Member]
Impairment Charges And Impairment Of Joint Venture Investments [Abstract]
Assets marketed for sale	$ 2,800	$ 0	$ 2,800	$ 0

The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Period Type:	duration