Share-Based Compensation (RSU Activity) (Details) shares in Thousands	6 Months Ended
Mar. 31, 2022 $ / shares shares
Shares
Forfeited \| shares	28
Options exercisable (shares) \| shares	3,752
Weighted Average Grant Date Fair Value/Share
Weighted average grant date fair value, forfeited (in dollars per share) \| $ / shares	$ 6.60
Weighted average exercise price, options vested and expected to vest (in dollars per share) \| $ / shares	$ 13.71
Restricted Stock Units (RSUs)
Shares
Outstanding at beginning of the period (shares) \| shares	1,209
Granted \| shares	321
Vested in period (shares) \| shares	(417)
Forfeited \| shares	27
Outstanding at beginning of the period \| shares	1,086
Options exercisable (shares) \| shares	1,049
Weighted Average Grant Date Fair Value/Share
Weighted average grant date fair value, nonvested, equity instruments other than options, beginning of the period (in dollar per share) \| $ / shares	$ 22.77
Weighted average grant date fair value, granted (in dollars per share) \| $ / shares	45.10
Weighted average grant date fair value, vested (in dollars per share) \| $ / shares	21.09
Weighted average grant date fair value, forfeited (in dollars per share) \| $ / shares	23.73
Weighted average grant date fair value, nonvested, equity instruments other than options, end of the period (in dollar per share) \| $ / shares	29.99
Weighted average exercise price, options vested and expected to vest (in dollars per share) \| $ / shares	$ 29.64
Special RSU
Shares
Outstanding at beginning of the period (shares) \| shares	469
Granted \| shares	124
Outstanding at beginning of the period \| shares	593
Options exercisable (shares) \| shares	546
Weighted Average Grant Date Fair Value/Share
Weighted average grant date fair value, nonvested, equity instruments other than options, beginning of the period (in dollar per share) \| $ / shares	$ 16.92
Weighted average grant date fair value, granted (in dollars per share) \| $ / shares	52.50
Weighted average grant date fair value, nonvested, equity instruments other than options, end of the period (in dollar per share) \| $ / shares	23.39
Weighted average exercise price, options vested and expected to vest (in dollars per share) \| $ / shares	$ 23.28

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).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued 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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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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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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

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-Publisher FASB
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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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Number of fully vested and expected to vest exercisable options that may be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of non-vested options forfeited.

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Weighted average grant-date fair value of non-vested options forfeited.

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