Segment Information - Business segment financial data (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenue recognition
Sales	$ 375,240	$ 347,806	$ 1,055,077	$ 1,005,128
Operating income (loss)	13,893	10,293	(3,270)	40,678
Depreciation and amortization	12,966	8,653	31,943	28,717
Cubic Transportation Systems
Revenue recognition
Sales	156,000	133,300	430,500	411,500
Operating income (loss)	20,500	11,700	43,900	50,800
Depreciation and amortization	1,200	2,800	5,400	8,400
Cubic Global Defense Systems
Revenue recognition
Sales	119,000	102,600	331,300	295,200
Operating income (loss)	900	3,200	(23,700)	2,800
Depreciation and amortization	8,700	3,900	19,700	13,300
Cubic Global Defense Services
Revenue recognition
Sales	100,200	111,900	293,300	298,400
Operating income (loss)	4,800	3,100	9,300	4,200
Depreciation and amortization	1,800	1,900	4,800	6,200
Corporate and other
Revenue recognition
Depreciation and amortization	1,300	100	2,000	800
Unallocated corporate expenses and other
Revenue recognition
Operating income (loss)	$ (12,300)	$ (7,700)	$ (32,800)	$ (17,100)