Restructuring Costs - Restructuring charges (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Restructuring plan
Cost incurred to date	$ 2,500		$ 2,500
Restructuring costs	8,505	$ 1,631	12,254	$ 3,382
Unallocated corporate expenses and other
Restructuring plan
Restructuring costs	4,500	1,000	7,400	1,800
Transportation Systems
Restructuring plan
Restructuring costs	2,600	300	2,700	1,000
Cubic Global Defense
Restructuring plan
Restructuring costs	$ 1,400	$ 300	$ 2,200	$ 600