REVENUES - Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025
Disaggregation of revenues
Revenues	$ 309,341	$ 231,777	$ 599,000	$ 446,370
Point in time
Disaggregation of revenues
Revenues	160,292	136,973	307,231	263,037
Over time
Disaggregation of revenues
Revenues	149,049	94,804	291,769	183,333
United States
Disaggregation of revenues
Revenues	199,066	153,823	389,059	307,683
International
Disaggregation of revenues
Revenues	110,275	77,954	209,941	138,687
Commercial
Disaggregation of revenues
Revenues	201,148	176,242	379,000	342,626
Government
Disaggregation of revenues
Revenues	108,193	55,535	220,000	103,744
A&D
Disaggregation of revenues
Revenues	150,310	89,627	294,139	171,495
A&D \| Point in time
Disaggregation of revenues
Revenues	69,877	52,364	136,412	99,359
A&D \| Over time
Disaggregation of revenues
Revenues	80,433	37,263	157,727	72,136
A&D \| United States
Disaggregation of revenues
Revenues	99,609	66,612	192,396	131,926
A&D \| International
Disaggregation of revenues
Revenues	50,701	23,015	101,743	39,569
A&D \| Commercial
Disaggregation of revenues
Revenues	55,937	48,702	101,733	94,458
A&D \| Government
Disaggregation of revenues
Revenues	94,373	40,925	192,406	77,037
USG
Disaggregation of revenues
Revenues	93,529	90,767	181,013	177,427
USG \| Point in time
Disaggregation of revenues
Revenues	75,227	73,002	143,515	142,280
USG \| Over time
Disaggregation of revenues
Revenues	18,302	17,765	37,498	35,147
USG \| United States
Disaggregation of revenues
Revenues	58,873	54,944	119,597	114,860
USG \| International
Disaggregation of revenues
Revenues	34,656	35,823	61,416	62,567
USG \| Commercial
Disaggregation of revenues
Revenues	89,982	89,649	175,721	173,928
USG \| Government
Disaggregation of revenues
Revenues	3,547	1,118	5,292	3,499
Test
Disaggregation of revenues
Revenues	65,502	51,383	123,848	97,448
Test \| Point in time
Disaggregation of revenues
Revenues	15,188	11,607	27,304	21,398
Test \| Over time
Disaggregation of revenues
Revenues	50,314	39,776	96,544	76,050
Test \| United States
Disaggregation of revenues
Revenues	40,584	32,267	77,066	60,897
Test \| International
Disaggregation of revenues
Revenues	24,918	19,116	46,782	36,551
Test \| Commercial
Disaggregation of revenues
Revenues	55,229	37,891	101,546	74,240
Test \| Government
Disaggregation of revenues
Revenues	$ 10,273	$ 13,492	$ 22,302	$ 23,208