Shared-Based Compensation - Components of Share-Based Compensation Expense by Type of Award (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	$ 763	$ 1,411	$ 1,649	$ 2,707
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	59	140	148	321
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	591	936	1,139	1,828
Performance share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	450	335	699	558
Change in estimate of share-based award vesting (1)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	$ (337)	$ 0	$ (337)	$ 0