Quarterly report pursuant to Section 13 or 15(d)

Business combinations - Changes in Goodwill (Details)

v3.21.2
Business combinations - Changes in Goodwill (Details)
$ in Thousands
 9 Months Ended
Jun. 30, 2021
USD ($)
Goodwill [Roll Forward]  
Balance at the beginning of the period $ 593,129
Estimated effects of acquisitions 1,161,923
Foreign currency translation 2,743
Balance at the end of the period 1,757,795
U.S. Services  
Goodwill [Roll Forward]  
Balance at the beginning of the period 164,472
Estimated effects of acquisitions 0
Foreign currency translation 0
Balance at the end of the period 164,472
U.S. Federal Services  
Goodwill [Roll Forward]  
Balance at the beginning of the period 381,719
Estimated effects of acquisitions 1,161,300
Foreign currency translation 0
Balance at the end of the period 1,543,019
Outside the U.S.  
Goodwill [Roll Forward]  
Balance at the beginning of the period 46,938
Estimated effects of acquisitions 623
Foreign currency translation 2,743
Balance at the end of the period $ 50,304