Condensed Combined Balance Sheets for LLCs/LPs Accounted Under Equity Method (Parenthetical) (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule Of Equity Method Investments [Line Items]
Right-of-use land assets	$ 8,922	$ 8,944
Right-of-use land liabilities	8,922	8,944
Limited Liability Companies
Schedule Of Equity Method Investments [Line Items]
Right-of-use land assets	3,700	3,700
Right-of-use land liabilities	$ 3,700	$ 3,700