BUSINESS SEGMENT INFORMATION (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Sep. 30, 2015 USD ($) segment	Sep. 30, 2014 USD ($)	Sep. 30, 2013 USD ($)
BUSINESS SEGMENT INFORMATION
Number of primary business segments | segment									3
Revenue recognition
Sales	$ 425,917	$ 347,806	$ 338,834	$ 318,488	$ 396,366	$ 340,357	$ 354,492	$ 307,137	$ 1,431,045	$ 1,398,352	$ 1,361,407
Operating income (loss)	34,709	$ 10,293	$ 23,206	$ 7,179	39,268	$ 19,215	$ 22,177	$ 11,830	75,387	92,490	40,735
Assets	1,300,276				1,194,606				1,300,276	1,194,606	1,108,400
Depreciation and amortization									37,662	30,440	25,359
Capital expenditures									22,202	16,620	9,052
Transportation Systems
Revenue recognition
Sales									566,800	599,700	529,500
Operating income (loss)									75,900	65,900	66,800
Assets	410,000				422,200				410,000	422,200	369,800
Depreciation and amortization									10,800	11,500	5,000
Capital expenditures									2,000	1,800	2,800
Sales to Transport for London									183,200	213,200	193,400
Cubic Global Defense Services
Revenue recognition
Sales									402,100	398,100	468,700
Operating income (loss)									6,600	7,800	(36,100)
Assets	200,700				195,800				200,700	195,800	205,200
Depreciation and amortization									8,500	10,700	13,000
Capital expenditures											300
Cubic Global Defense Systems
Revenue recognition
Sales									462,100	400,600	363,000
Operating income (loss)									18,400	26,800	14,200
Assets	341,200				252,400				341,200	252,400	228,900
Depreciation and amortization									17,100	7,400	6,100
Capital expenditures									600	13,200	4,600
Other
Revenue recognition
Sales											200
Corporate and other
Revenue recognition
Assets	$ 348,400				$ 324,200				348,400	324,200	304,500
Depreciation and amortization									1,300	800	1,300
Capital expenditures									19,600	1,600	1,400
CGD services and CGD systems segments
Revenue recognition
Sales to U.S. government agencies									670,000	651,500	691,800
Unallocated corporate expenses and other
Revenue recognition
Operating income (loss)									$ (25,500)	$ (8,000)	$ (4,200)