Implementation of the New Revenue Recognition Standard - Cumulative effect on Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Oct. 01, 2018	Sep. 30, 2018
Current assets:
Accounts receivable - net	$ 178,849	$ 155,624	$ 392,367
Contract assets	275,422	272,210
Recoverable income taxes	8,701	91	91
Inventories	124,297	61,688	84,199
Assets held for sale		8,177	8,177
Other current assets		43,705	43,705
Total current assets	717,847	681,103	668,147
Long-term contracts receivables			6,134
Long-term contracts financing receivables			6,134
Property, plant and equipment, net	137,004	117,546	117,546
Deferred income taxes	5,102	5,102	4,713
Goodwill	578,945	333,626	333,626
Purchased intangibles, net	175,207	73,533	73,533
Other assets	70,396
Total assets	1,814,885	1,321,130	1,304,883
Current liabilities:
Short-term borrowings	231,000
Contract liabilities	62,266	70,127
Customer advances			75,941
Accrued compensation and other current liabilities		118,816	118,233
Income taxes payable	1,292	8,586	8,586
Total current liabilities	552,160	320,097	328,339
Shareholders' equity:
Common stock	268,965	45,008	45,008
Retained earnings	825,396	821,668	801,834
Accumulated other comprehensive loss	(112,470)	(110,643)	(110,643)
Treasury stock at cost	(36,078)	(36,078)	(36,078)
Shareholders' equity related to Cubic	945,813	719,955	700,121
Noncontrolling interest in consolidated VIE	19,769	28,730	24,075
Total shareholders' equity	965,582	748,685	724,196
Total liabilities and shareholders' equity	1,814,885	1,321,130	1,304,883
Cubic Corporation Excluding VIE
Current assets:
Cash and cash equivalents	62,522	111,834	111,834
Restricted cash	17,062	17,400	17,400
Other current assets	40,615		43,705
Long-term contracts financing receivables	38,885	56,228
Long-term capitalized contract costs			84,924
Other assets	70,396	14,192	14,192
Current liabilities:
Trade accounts payable	154,291	122,403	125,414
Accrued compensation and other current liabilities	92,327		118,233
Long-term debt	189,103	199,793	199,793
Other long term liabilities	45,152	43,486	43,486
OpCo.
Current assets:
Cash and cash equivalents	359	374	374
Restricted cash	9,967	10,000	10,000
Other current assets	53
Long-term contracts financing receivables	90,233	38,990
Long-term capitalized contract costs			1,258
Other assets	1,266	810	810
Current liabilities:
Trade accounts payable	88	165	165
Accrued compensation and other current liabilities	183
Long-term debt	45,991	9,056	9,056
Other long term liabilities	16,897	$ 13	13
ASU 2014-09 | ASC 606
Current assets:
Accounts receivable - net	(215,928)		(236,743)
Contract assets	280,474		272,210
Recoverable income taxes	220
Inventories	(46,950)		(22,511)
Total current assets	17,816		12,956
Long-term contracts receivables	(3,201)		(6,134)
Deferred income taxes	235		389
Total assets	22,382		16,247
Current liabilities:
Contract liabilities	62,266		70,127
Customer advances	(78,760)		(75,941)
Accrued compensation and other current liabilities			583
Income taxes payable	266
Total current liabilities	(18,481)		(8,242)
Shareholders' equity:
Retained earnings	28,238		19,834
Shareholders' equity related to Cubic	28,238		19,834
Noncontrolling interest in consolidated VIE	12,625		4,655
Total shareholders' equity	40,863		24,489
Total liabilities and shareholders' equity	22,382		16,247
ASU 2014-09 | Cubic Corporation Excluding VIE | ASC 606
Current assets:
Long-term contracts financing receivables	38,885		56,228
Long-term capitalized contract costs	(119,331)		(84,924)
Current liabilities:
Trade accounts payable	(2,253)		(3,011)
ASU 2014-09 | OpCo. | ASC 606
Current assets:
Long-term contracts financing receivables	90,233		38,990
Long-term capitalized contract costs	$ (2,255)		$ (1,258)