Summary of Significant Accounting Policies - Warranty (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Movement in Standard Product Warranty Accrual [Roll Forward]
Warranty beginning balance	$ 795	$ 793
Additions for warranties issued during the period	383	146
Reductions in the liability for payments made under the warranty	(27)	(109)
Changes related to pre-existing warranties	(245)	(54)
Currency translation adjustment	(27)	(10)
Warranty ending balance	$ 879	$ 766
Minimum
Product Warranty [Line Items]
Standard product warranty, period	12 months
Maximum
Product Warranty [Line Items]
Standard product warranty, period	24 months