Segment and Geographic Information - Long-Lived Assets, Consisting of Property, Plant and Equipment by Geographic Area (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	$ 117,665	$ 100,669
North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	79,366	72,401
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	79,400	72,300
Asia/Pacific/Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	25,117	15,628
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	$ 13,182	$ 12,640