Stock Based Compensation - Narrative (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense (gain)	$ 2,200	$ 2,100
Unrecognized stock-based compensation cost	$ 8,200
Unrecognized share-based compensation expense, weighted-average recognition period (in years)	1 year 6 months 14 days
Common stock issuance ESPP Plan	$ 796	$ 419
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation cost	$ 4,400
Unrecognized share-based compensation expense, weighted-average recognition period (in years)	1 year 3 months 14 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)	34,330	36,154
Common stock issuance ESPP Plan	$ 200	$ 100

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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