Implementation of the New Revenue Recognition Standard - Cumulative effect on Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Oct. 01, 2018	Sep. 30, 2018	Sep. 30, 2017
Current assets:
Accounts receivable, net	$ 126,014	$ 155,624	$ 392,367
Contract assets	349,559	272,210
Recoverable income taxes	7,754	91	91
Inventories	106,794	61,688	84,199
Assets held for sale		8,177	8,177
Other current assets		43,705	43,705
Total current assets	724,309	681,103	668,147
Long-term contracts receivables			6,134
Property, plant and equipment, net	144,969	117,546	117,546
Deferred income taxes	4,098	5,102	4,713
Goodwill	578,097	333,626	333,626	$ 321,562
Purchased intangibles, net	165,613	73,533	73,533
Other assets	76,872
Total assets	1,847,170	1,321,130	1,304,883	$ 1,336,300
Current liabilities:
Short-term borrowings	195,500
Contract liabilities	46,170	70,127
Customer advances			75,941
Accrued compensation and other current liabilities		118,816	118,233
Income taxes payable	773	8,586	8,586
Total current liabilities	529,159	320,097	328,339
Long-term debt	189,111		199,793
Accrued pension liability	25,386	7,802	7,802
Deferred compensation	11,040	11,476	11,476
Income taxes payable	937	2,406	2,406
Deferred income taxes	4,554	2,689	2,689
Shareholders' equity:
Common stock	274,472	45,008	45,008
Retained earnings	862,948	821,668	801,834
Accumulated other comprehensive loss	(139,693)	(110,643)	(110,643)
Treasury stock at cost	(36,078)	(36,078)	(36,078)
Shareholders' equity related to Cubic	961,649	719,955	700,121
Noncontrolling interest in VIE	18,919	28,730	24,075
Total shareholders' equity	980,568	748,685	724,196
Total liabilities and shareholders' equity	1,847,170	1,321,130	1,304,883
Cubic Corporation Excluding VIE
Current assets:
Cash and cash equivalents	65,800	111,834	111,834
Restricted cash	19,507	17,400	17,400
Other current assets	38,534		43,705
Long-term contracts financing receivables	36,285	56,228
Long-term capitalized contract costs			84,924
Other assets	76,872	14,192	14,192
Current liabilities:
Trade accounts payable	180,773	122,403	125,414
Long-term debt	189,110	199,793	199,793
Other long term liabilities	22,817	19,113	19,113
OpCo.
Current assets:
Cash and cash equivalents	347	374	374
Restricted cash	9,967	10,000	10,000
Other current assets	33
Long-term contracts financing receivables	115,508	38,990
Long-term capitalized contract costs			1,258
Other assets	1,419	810	810
Current liabilities:
Trade accounts payable	25	165	165
Long-term debt	61,994	9,056	9,056
Other long term liabilities	21,605	$ 13	13
ASU 2014-09 | ASC 606
Current assets:
Accounts receivable, net	(273,625)		(236,743)
Contract assets	349,559		272,210
Recoverable income taxes	1,029
Inventories	(51,919)		(22,511)
Total current assets	25,044		12,956
Long-term contracts receivables	(3,077)		(6,134)
Deferred income taxes			389
Total assets	34,411		16,247
Current liabilities:
Contract liabilities	46,170		70,127
Customer advances	(56,001)		(75,941)
Accrued compensation and other current liabilities			583
Income taxes payable	621
Total current liabilities	(11,108)		(8,242)
Shareholders' equity:
Retained earnings	28,599		19,834
Shareholders' equity related to Cubic	28,599		19,834
Noncontrolling interest in VIE	16,920		4,655
Total shareholders' equity	45,519		24,489
Total liabilities and shareholders' equity	34,411		16,247
ASU 2014-09 | Cubic Corporation Excluding VIE | ASC 606
Current assets:
Long-term contracts financing receivables	36,285		56,228
Long-term capitalized contract costs	(136,804)		(84,924)
Current liabilities:
Trade accounts payable	(1,898)		(3,011)
ASU 2014-09 | OpCo. | ASC 606
Current assets:
Long-term contracts financing receivables	115,508		38,990
Long-term capitalized contract costs	$ (2,545)		$ (1,258)