Equity and Redeemable Non-controlling Interest - Schedule of Company's Outstanding Shares of Common Stock (Parenthetical) (Detail) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Jan. 31, 2019	Sep. 30, 2020	Sep. 30, 2020
Class Of Stock [Line Items]
Amortization period of grant	4 years
Class I Shares [Member]
Class Of Stock [Line Items]
Independent directors' restricted stock grant, value		$ 0.1	$ 0.1
Amortization period of grant			1 year