REVENUES - Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	$ 205,501	$ 177,010
Point in time
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	98,736	92,214
Over time
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	106,765	84,796
United States
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	142,816	122,403
International
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	62,685	54,607
Commercial
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	152,894	131,954
U.S. Government
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	52,607	45,056
Aerospace & Defense
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	82,983	70,244
Aerospace & Defense | Point in time
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	33,604	28,558
Aerospace & Defense | Over time
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	49,379	41,686
Aerospace & Defense | United States
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	68,934	60,687
Aerospace & Defense | International
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	14,049	9,557
Aerospace & Defense | Commercial
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	36,740	28,075
Aerospace & Defense | U.S. Government
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	46,243	42,169
USG
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	71,045	63,485
USG | Point in time
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	56,031	50,835
USG | Over time
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	15,014	12,650
USG | United States
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	46,379	38,741
USG | International
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	24,666	24,744
USG | Commercial
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	70,162	62,842
USG | U.S. Government
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	883	643
Test
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	51,473	43,281
Test | Point in time
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	9,101	12,821
Test | Over time
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	42,372	30,460
Test | United States
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	27,503	22,975
Test | International
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	23,970	20,306
Test | Commercial
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	45,992	41,037
Test | U.S. Government
Disaggregation of revenues
Revenue from contract with customer excluding assessed tax	$ 5,481	$ 2,244