GOODWILL AND PURCHASED INTANGIBLE ASSETS (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2015 USD ($) item	Sep. 30, 2014 USD ($)	Sep. 30, 2013 USD ($)
Goodwill [Roll Forward]
Balance at the beginning of the period	$ 184,141	$ 136,094
Goodwill, Acquired During Period	57,875	48,157
Foreign currency exchange rate changes	(4,117)	(110)
Balance at the end of the period	237,899	184,141	$ 136,094
Impairment of goodwill	$ 0		50,865
Number of remaining reporting units whose estimated fair values exceeded carrying values | item	3
Transportation Systems
Goodwill [Roll Forward]
Balance at the beginning of the period	$ 59,167	18,301
Goodwill, Acquired During Period		40,792
Foreign currency exchange rate changes	(3,193)	74
Balance at the end of the period	$ 55,974	59,167	18,301
Transportation Systems | Minimum
Goodwill [Roll Forward]
Estimated percentage of excess of fair value over carrying value	20.00%
Cubic Global Defense Systems
Goodwill [Roll Forward]
Balance at the beginning of the period	$ 30,624	23,443
Goodwill, Acquired During Period	57,875	7,365
Foreign currency exchange rate changes	(924)	(184)
Balance at the end of the period	$ 87,575	30,624	23,443
Cubic Global Defense Systems | Minimum
Goodwill [Roll Forward]
Estimated percentage of excess of fair value over carrying value	20.00%
Cubic Global Defense Services
Goodwill [Roll Forward]
Balance at the beginning of the period	$ 94,350	94,350
Balance at the end of the period	$ 94,350	$ 94,350	$ 94,350
Decrease in future years' projected cash flows requiring additional analysis for goodwill impairment	12.00%
Cubic Global Defense Services | Minimum
Goodwill [Roll Forward]
Estimated percentage of excess of fair value over carrying value	10.00%