Fair Value Measurement - Amount of Gains and Losses from Changes in Fair Value Included in Earnings (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Change in fair value			$ 3,363	$ (2,559)
Construction [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Change in fair value	$ 122	$ (362)	3,363	(2,559)
Total change in fair value	$ 122	$ (362)	$ 3,363	$ (2,559)