Financial Instruments - Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Increase (decrease) in fair value:
Interest rate agreements	$ (22,716)	$ (1,332)
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Interest rate agreements	458	377
Total other comprehensive income (loss) from hedging, net of tax	$ (22,258)	$ (955)

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).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669646-108580

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration