Shared-Based Compensation - Components of Share-Based Compensation Expense by Type of Award (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	$ 858	$ (124)	$ 3,565	$ 1,855
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	132	371	453	732
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	963	446	2,791	1,407
Performance share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	340	334	898	991
Change in estimate of share-based award vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	$ (577)	$ (1,275)	$ (577)	$ (1,275)