Equity - Schedule of Non-Vested Restricted Stock Units Compensation (Detail) - USD ($) $ in Thousands	3 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total expected compensation expense related to RSUs	$ 352	$ 447
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total expected compensation expense related to RSUs	16,056
Recognized compensation expense related to RSUs	(13,262)
Unrecognized compensation expense related to RSUs	$ 2,794
Weighted average remaining years to expense for RSUs	2 years 9 months 18 days

Amount of cost capitalized for award under share-based payment arrangement.

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Amount of noncash expense for share-based payment arrangement.

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