CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Net sales:
Net sales	$ 343,408	$ 321,482	$ 662,202	$ 650,321
Costs and expenses:
Selling, general and administrative expenses	83,141	78,294	146,801	144,209
Research and development	14,368	11,360	26,514	19,782
Amortization of purchased intangibles	15,033	16,493	31,140	26,582
(Gain) loss on sale of property, plant and equipment	125	40	125	(130)
Restructuring costs	7,746	3,807	11,881	5,382
Total costs and expenses	368,963	351,416	686,460	686,738
Operating loss	(25,555)	(29,934)	(24,258)	(36,417)
Other income (expenses):
Interest and dividend income	1,946	1,693	3,735	3,911
Interest expense	(6,734)	(8,219)	(14,905)	(13,582)
Loss on extinguishment of debt		(16,090)		(16,090)
Other income (expense), net	14,543	(19,664)	15,839	(19,791)
Loss from continuing operations before income taxes	(15,800)	(72,214)	(19,589)	(81,969)
Income tax provision (benefit)	3,440	(19,784)	6,929	(13,538)
Loss from continuing operations	(19,240)	(52,430)	(26,518)	(68,431)
Net income (loss) from discontinued operations		129		(455)
Net loss	(19,240)	(52,301)	(26,518)	(68,886)
Less noncontrolling interest in net income (loss) of VIE	16,777	(13,178)	22,494	(9,188)
Net loss attributable to Cubic	(36,017)	(39,123)	(49,012)	(59,698)
Amounts attributable to Cubic:
Net loss from continuing operations	(36,017)	(39,252)	(49,012)	(59,243)
Net loss from discontinued operations		129		(455)
Net loss attributable to Cubic	$ (36,017)	$ (39,123)	$ (49,012)	$ (59,698)
Basic
Continuing operations attributable to Cubic (in dollars per share)	$ (1.14)	$ (1.25)	$ (1.55)	$ (1.89)
Discontinued operations (in dollars per share)				(0.01)
Basic earnings per share attributable to Cubic (in dollars per share)	(1.14)	(1.25)	(1.55)	(1.91)
Diluted
Continuing operations attributable to Cubic (in dollars per share)	(1.14)	(1.25)	(1.55)	(1.89)
Discontinued operations (in dollars per share)				(0.01)
Diluted earnings per share attributable to Cubic (in dollars per share)	$ (1.14)	$ (1.25)	$ (1.55)	$ (1.91)
Weighted average shares used in per share calculations:
Basic (in shares)	31,633	31,296	31,598	31,284
Diluted (in shares)	31,633	31,296	31,598	31,284
Products
Net sales:
Net sales	$ 200,428	$ 187,494	$ 381,917	$ 388,098
Costs and expenses:
Costs	149,671	153,002	287,690	319,845
Services
Net sales:
Net sales	142,980	133,988	280,285	262,223
Costs and expenses:
Costs	$ 98,879	$ 88,420	$ 182,309	$ 171,068