Financial Instruments Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2020	Sep. 30, 2019
Other Comprehensive Income [Abstract]
Total other comprehensive income (loss) from hedging, net of tax	$ 56,888	$ (22,944)
Expected Earnings [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	3,647	3,022
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	53,241	$ (25,966)
Interest rate agreements
Expected Earnings [Line Items]
FY2021	(4,569)
FY2022	(4,569)
FY2023	(4,569)
FY2024	(4,569)
FY2025	(4,569)
Thereafter	(91,657)
Total	$ (114,502)

Cash Flow Hedge Gain (Loss) To Be Recassiflied, Total

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Cash Flow Hedge Gain (Loss) To Be Reclassifed Year Two

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Cash Flow Hedge Gain (Loss) To Be Reclassified After Year Five

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Cash Flow Hedge Gain (Loss) To Be Reclassified Year Five

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Cash Flow Hedge Gain (Loss) To Be Reclassified Year Four

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The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss), attributable to parent entity.

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Amount after tax of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).

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Amount after tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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