Accounting Changes and Recent Accounting Pronouncements - Schedule of Effect of ASU No. 2014-09 Adoption on Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Sep. 30, 2018
Recent Accounting Pronouncements
Other current assets	$ 39,895	$ 42,960
Accrued liabilities	156,490	$ 180,287
ASU 2014-09 \| Excluding ASU No. 2014-09 Effect
Recent Accounting Pronouncements
Other current assets	37,256
Accrued liabilities	153,851
ASU 2014-09 \| ASU No. 2014-09 Effect
Recent Accounting Pronouncements
Other current assets	2,639
Accrued liabilities	$ 2,639

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_AccruedLiabilitiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant