Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019
Long-term debt
Long-term debt, Carrying Value	$ 1,813,168	$ 1,609,296
Long-term debt, Fair Value	1,837,104	1,608,644
Level 1 \| Senior notes
Long-term debt
Long-term debt, Carrying Value	1,177,380	885,296
Long-term debt, Fair Value	1,217,707	898,814
Level 2 \| Other Long-Term Debt
Long-term debt
Long-term debt, Carrying Value	635,788	724,000
Long-term debt, Fair Value	619,397	709,830
Fair value measurement on recurring basis
Financial Assets
Total assets	194,639	344
Fair value measurement on recurring basis \| Level 1 \| Cash and cash equivalents
Financial Assets
Cash equivalents	194,612
Fair value measurement on recurring basis \| Level 2 \| Other assets
Financial Assets
Interest rate caps	$ 27	$ 344

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value as of the balance sheet date of all interest rate derivative assets designated as cash flow hedging instruments.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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