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Stock Based Compensation - Narrative (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense (gain)	$ 5,200			$ 2,700			$ 12,400	$ 7,500
Unrecognized stock-based compensation cost	14,000						$ 14,000
Unrecognized share-based compensation expense, weighted-average recognition period (in years)							2 years 2 months 12 days
Common stock issuance ESPP Plan	1,020	$ 1,245	$ 1,024	$ 808	$ 928	$ 796
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation cost	$ 12,000						$ 12,000
Unrecognized share-based compensation expense, weighted-average recognition period (in years)							1 year 9 months 18 days
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan, discount rate (as a percent)							15.00%
Common stock issuance ESPP Plan (in shares)	27,210			29,853			82,966	105,241
Common stock issuance ESPP Plan	$ 200			$ 200			$ 800	$ 600