SUMMARY OF QUARTERLY RESULTS OF OPERATIONS (UNAUDITED) - Quarterly results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
SUMMARY OF QUARTERLY RESULTS OF OPERATIONS (UNAUDITED)
Net sales	$ 406,588	$ 375,240	$ 366,024	$ 313,813	$ 425,917	$ 347,806	$ 338,834	$ 318,488	$ 1,461,665	$ 1,431,045	$ 1,398,352
Operating income (loss)	10,488	13,893	(9,086)	(8,077)	34,709	10,293	23,206	7,179	7,218	75,387	92,490
Net income (loss) attributable to Cubic	$ (7,493)	$ 4,498	$ 10,144	$ (5,414)	$ 19,977	$ 8,780	$ (11,024)	$ 5,152	$ 1,735	$ 22,885	$ 69,491
Net income (loss) per share, basic (in dollars per share)	$ (0.29)	$ 0.17	$ 0.38	$ (0.20)	$ 0.74	$ 0.33	$ (0.41)	$ 0.19	$ 0.06	$ 0.85	$ 2.59
Net income (loss) per share, diluted (in dollars per share)	$ (0.29)	$ 0.17	$ 0.38	$ (0.20)	$ 0.74	$ 0.33	$ (0.41)	$ 0.19	$ 0.06	$ 0.85	$ 2.59