Share-Based Compensation and Stock Repurchases - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested share-based compensation arrangements	$ 4,200
Unrecognized compensation cost, period for recognition	2 years
Share-based compensation expense	$ 900	$ 1,300
Repurchased shares, value	$ 19	$ 41
Board of Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vesting period	1 year
Restricted Stock Units [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vesting period	3 years
Restricted Stock Units [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vesting period	5 years
Restricted Stock Award \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vesting period	3 years
Restricted Stock Award \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vesting period	5 years
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchased shares, shares	2,256
Repurchased shares, value	$ 20

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

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