CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Operating Activities:
Net loss	$ (19,240)	$ (52,301)	$ (26,518)	$ (68,886)
Net income (loss) from discontinued operations		(129)		455
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	25,055	23,414	49,716	40,364
Share-based compensation expense	6,472	5,382	11,151	9,859
Change in fair value of contingent consideration	1,260	(1,473)	684	(4,478)
Deferred income taxes	161	2,909	(977)	2,909
Loss on extinguishment of debt		16,090		16,090
Other items	2,094	13	5,705	4,308
Changes in operating assets and liabilities, net of effects from acquisitions	(37,150)	(36,281)	(80,027)	(86,222)
NET CASH USED IN OPERATING ACTIVITIES FROM CONTINUING OPERATIONS	(36,439)	(26,557)	(58,609)	(74,119)
NET CASH PROVIDED BY OPERATING ACTIVITIES FROM DISCONTINUED OPERATIONS		129		85
NET CASH USED IN OPERATING ACTIVITIES	(36,439)	(26,428)	(58,609)	(74,034)
Investing Activities:
Acquisition of businesses, net of cash acquired		(234,538)		(234,538)
Purchases of property, plant and equipment	(13,389)	(13,478)	(20,053)	(25,311)
Purchase of non-marketable debt and equity securities	(1,446)		(1,446)
Receipt of withheld proceeds from sale of trade receivables	641		2,483	5,521
NET CASH USED IN INVESTING ACTIVITIES	(14,194)	(248,016)	(19,016)	(254,328)
Financing Activities:
Proceeds from short-term borrowings	104,786	727,000	186,644	884,500
Principal payments on short-term borrowings	(32,956)	(616,500)	(123,646)	(743,000)
Principal payments on long-term borrowings	(3,653)	(199,833)	(5,625)	(199,833)
Debt extinguishment make-whole payment		(15,856)		(15,856)
Deferred financing fees		(2,517)		(2,517)
Principal payments on finance lease liability	(673)		(691)
Proceeds from stock issued under employee stock purchase plan	1,170		1,170	1,169
Purchase of common stock	(1,004)	(39)	(4,014)	(3,660)
Shares repurchased for tax withholdings	(5,243)		(5,243)
Dividends paid	(4,270)	(4,225)	(4,270)	(4,225)
Contingent consideration payments related to acquisitions of businesses	(1,006)		(1,006)
NET CASH PROVIDED BY FINANCING ACTIVITIES	77,126	341,066	85,828	389,800
Effect of exchange rates on cash	(2,448)	(11,224)	6,078	(7,203)
NET INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	24,045	55,398	14,281	54,235
Cash, cash equivalents and restricted cash at the beginning of the period	147,220	94,458	156,984	95,621
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT THE END OF THE PERIOD	171,265	149,856	171,265	149,856
PIXIA Corp
Supplemental disclosure of non-cash investing and financing activities:
Receivable recognized in connection with the acquisition of net		1,214		1,214
Delerrok Inc.
Adjustments to reconcile net loss to net cash used in operating activities:
Change in fair value of contingent consideration			(900)
Supplemental disclosure of non-cash investing and financing activities:
Contingent consideration liability incurred with the acquisition		1,600		1,600
Cubic Corporation Excluding VIE
Financing Activities:
Proceeds from long-term borrowings	1,008	450,000	1,008	450,000
VIE
Adjustments to reconcile net loss to net cash used in operating activities:
Change in fair value of interest rate swap	(15,091)	15,819	(18,343)	11,482
Financing Activities:
Proceeds from long-term borrowings	$ 18,967	$ 3,036	$ 41,501	$ 23,222