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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	$ 931	$ 858	$ 2,580	$ 3,565
Discontinued Operations
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation		(200)		200
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	59	132	207	453
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	521	963	1,660	2,791
Performance share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	351	340	1,050	898
Change in estimate of share-based award vesting (1)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	$ 0	$ (577)	$ (337)	$ (577)