Equity-Based Compensation - Summary of restricted stock award activity (Details)	12 Months Ended
Sep. 30, 2021 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price [Roll Forward]
Weighted Average Exercise Price, Outstanding at October 1, 2020	$ 20.08
Granted, weighted average exercise price	13.78
Exercised, Weighted Average Exercise Price	13.98
Forfeited, weighted average exercise price	20.84
Weighted Average Exercise Price, Outstanding at September 30, 2021	$ 21.55
Restricted Stock Units R S U [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Beginning balance, Outstanding \| shares	749,000
Granted \| shares	876,000
Exercised \| shares	221,000
Forfeited \| shares	105,000
Ending balance, Outstanding \| shares	1,299,000
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price [Roll Forward]
Weighted Average Exercise Price, Outstanding at October 1, 2020	$ 16.58
Granted, weighted average exercise price	14.28
Exercised, Weighted Average Exercise Price	16.68
Forfeited, weighted average exercise price	15.20
Weighted Average Exercise Price, Outstanding at September 30, 2021	$ 15.14
Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Beginning balance, Outstanding \| shares	1,123,000
Granted \| shares
Exercised \| shares	253,000
Forfeited \| shares	68,000
Ending balance, Outstanding \| shares	802,000
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price [Roll Forward]
Weighted Average Exercise Price, Outstanding at October 1, 2020	$ 15.12
Granted, weighted average exercise price
Exercised, Weighted Average Exercise Price	17.54
Forfeited, weighted average exercise price	16.47
Weighted Average Exercise Price, Outstanding at September 30, 2021	$ 14.31

Share based compensation arrangement by share based payment award redeemed units in period.

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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- Definition

Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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