Guarantees - Narrative (Details)	12 Months Ended
Sep. 30, 2017
Minimum
Product Warranty Liability [Line Items]
Product warranty specification period	12 months
Maximum
Product Warranty Liability [Line Items]
Product warranty specification period	24 months

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.

No definition available.

Name:	us-gaap_ProductWarrantyLiabilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration