Summary of Significant Accounting Policies - Summary of Consideration Received, Consideration Transferred and Resulting Net Gain on Deconsolidation (Detail) - Cabs Joint Venture - USD ($)		1 Months Ended
	Nov. 01, 2019	Nov. 30, 2019
Schedule Of Equity Method Investments [Line Items]
Retained investment (at fair value)	$ 13,831,000
Contributed net assets (at carrying value)	13,394,000
Gain on deconsolidation	437,000
Less: deal costs	(179,000)
Net gain on deconsolidation	$ 258,000	$ 50,000