Fair Value Measurements and Derivatives Instruments - Additional Information (Details) - USD ($)	6 Months Ended
Mar. 31, 2019	Sep. 30, 2018
Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 1,000,000,000	$ 1,560,000,000
Interest Rate Swaps
Derivative [Line Items]
Net deferred losses on interest rate swap net of taxes expected to be recognized over the next 12 months	$ 6,594,000
Maximum
Derivative [Line Items]
Percentage of participants compensation deferred	70.00%

Deferred compensation arrangement percentage of participants compensation deferred.

No definition available.

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- Definition

Net deferred losses net of taxes expected to be recognized in interest expense.

+ References

No definition available.

+ Details

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- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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- Details

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- Details

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