Annual report pursuant to Section 13 and 15(d)

Goodwill And Intangiable Assets - Schedule of goodwill (Details)

v3.22.2.2
Goodwill And Intangiable Assets - Schedule of goodwill (Details) - USD ($)
$ in Thousands
 12 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2020
Goodwill [Roll Forward]      
Balance at the beginning of the period $ 1,774,406 $ 593,129  
Acquisitions 13,681 1,179,943  
Foreign currency translation (8,672) 1,334  
Balance at the end of the period 1,779,415 1,774,406 $ 593,129
Goodwill, impairment charges 0 0 0
U.S. Federal Services      
Goodwill [Roll Forward]      
Balance at the beginning of the period 1,549,921 381,719  
Acquisitions 9,942 1,168,202  
Foreign currency translation 0 0  
Balance at the end of the period 1,559,863 1,549,921 381,719
U.S. Services      
Goodwill [Roll Forward]      
Balance at the beginning of the period 164,472 164,472  
Acquisitions 0 0  
Foreign currency translation 0 0  
Balance at the end of the period 164,472 164,472 164,472
Outside the U.S.      
Goodwill [Roll Forward]      
Balance at the beginning of the period 60,013 46,938  
Acquisitions 3,739 11,741  
Foreign currency translation (8,672) 1,334  
Balance at the end of the period $ 55,080 $ 60,013 $ 46,938