Benefit Plans (Contributions) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Multiemployer plan, contributions	$ 993	$ 983	$ 963
Pensioenfonds Metaal en Techniek (PMT) | Multiemployer Plans, Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Multiemployer plan, contributions	805	796	805
Other plans | Multiemployer Plans, Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Multiemployer plan, contributions	$ 188	$ 187	$ 158