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Earnings Per Share and Equity - Summary of Basic and Diluted Net Income per Common Share Available to Common Shareholders (Detail) - $ / shares shares in Thousands	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Line Items]
Net income per common share available to common shareholders - Basic	$ 0.31	$ 0.55
Shares used in computing net income per common share available to common shareholders - Basic	35,023	34,518
Net income per common share available to common shareholders - Diluted	$ 0.31	$ 0.54
Shares used in computing net income per common share available to common shareholders - Diluted	35,182	35,113
As Previously Reported
Earnings Per Share [Line Items]
Net income per common share available to common shareholders - Basic		$ 0.80
Shares used in computing net income per common share available to common shareholders - Basic		23,903
Net income per common share available to common shareholders - Diluted		$ 0.55
Shares used in computing net income per common share available to common shareholders - Diluted		34,821
As Restated
Earnings Per Share [Line Items]
Net income per common share available to common shareholders - Basic		$ 0.55
Shares used in computing net income per common share available to common shareholders - Basic		34,518
Net income per common share available to common shareholders - Diluted		$ 0.54
Shares used in computing net income per common share available to common shareholders - Diluted		35,113

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