Basis for Presentation (Details)	12 Months Ended
Sep. 30, 2017
Basis for Presentation
Net Sales, Recognized under Units-of-Delivery Method	22.00%

Represents the percentage of net sales used the units-of-delivery method to recognize revenue during the year.

No definition available.

Name:	cub_PercentageOfNetSalesRecognizedUnderUnitsOfDeliveryMethod
Namespace Prefix:	cub_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration