Stock-Based Compensation - Board of Director Equity Awards - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Apr. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Director share awards		60,998	79,918
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Director share awards		60,998	79,918
Company's stock at fair value		$ 400	$ 400
Service Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants vesting period	1 year
Service Based Restricted Stock [Member] | One New Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants vesting period		3 years
Service Based Restricted Stock [Member] | New Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards granted		$ 55