Stock-Based Compensation - Summary of Stock and Stock Unit Award Activity (Details) shares in Thousands	6 Months Ended
Mar. 31, 2024 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested balance at October 1, 2023	15,881
Granted	12,271
Vested	(1,279)
Forfeited/canceled	(573)
Nonvested Balance at March 31, 2024	26,300
Nonvested beginning balance, Weighted Average Grant Date Fair Value \| $ / shares	$ 23.09
Weighted Average Grant Date Fair Value of shares granted \| $ / shares	25.89
Weighted Average Grant Date Fair Value of shares vested \| $ / shares	23.49
Weighted Average Grant Date Fair Value of shares forfeited/canceled \| $ / shares	21.87
Nonvested ending balance, Weighted Average Grant Date Fair Value \| $ / shares	$ 24.40
Time-Based Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested balance at October 1, 2023	12,782
Granted	11,829
Vested	(1,117)
Forfeited/canceled	(270)
Nonvested Balance at March 31, 2024	23,224
Performance-Based Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested balance at October 1, 2023	3,099
Granted	442
Vested	(162)
Forfeited/canceled	(303)
Nonvested Balance at March 31, 2024	3,076

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

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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

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- Definition

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 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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- 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

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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.

+ References

No definition available.

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- Definition

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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- Definition

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

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- Definition

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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