Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended		6 Months Ended
	May 04, 2021	Apr. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 25, 2021	Jan. 14, 2021	Dec. 31, 2020	Nov. 24, 2020
Class Of Stock [Line Items]
Capital stock, shares authorized	350,000,000								250,000,000
Proceeds from issuance of Class A Common Stock, net of offering costs					$ 14,422	$ 7,280
Class A Common Stock [Member]
Class Of Stock [Line Items]
Common stock, shares authorized	200,000,000		200,000,000		200,000,000				100,000,000
Increase in shares authorized	100,000,000
Common stock par value			$ 0.01		$ 0.01				$ 0.01
Class A Common Stock [Member] | Cantor Fitzgerald [Member] | ATM Offering [Member]
Class Of Stock [Line Items]
Common stock par value		$ 0.01
Aggregate offering price							$ 50,000	$ 5,500
Shares sold			2,180,337	2,638,306	2,180,337	2,638,306
Proceeds from issuance of Class A Common Stock, net of offering costs			$ 5,300	$ 7,300	$ 5,300	$ 7,300
Class A Common Stock [Member] | Cantor Fitzgerald [Member] | ATM Offering [Member] | Maximum [Member]
Class Of Stock [Line Items]
Aggregate offering price		$ 13,000
Class A Common Stock [Member] | LPC Purchase Agreement [Member]
Class Of Stock [Line Items]
Proceeds from issuance of Class A Common Stock, net of offering costs			$ 1,000		$ 9,100
Stock Issued During Period Shares New Issues			441,726		3,941,726
Class A Common Stock [Member] | LPC Purchase Agreement [Member] | Maximum [Member]
Class Of Stock [Line Items]
Aggregate offering price										$ 47,000
Class A And Class B Common Stock [Member]
Class Of Stock [Line Items]
Common stock, shares authorized	300,000,000								200,000,000