Quarterly report [Sections 13 or 15(d)]

Business Segments - Financial Information by Segment (Details)

v3.25.1
Business Segments - Financial Information by Segment (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2025
Mar. 31, 2024
Revenue:        
Revenue $ 1,361,786 $ 1,348,357 $ 2,764,461 $ 2,675,398
Gross profit:        
Gross profit $ 338,821 $ 317,589 $ 640,378 $ 617,643
Gross profit (as a percent) 24.90% 23.60% 23.20% 23.10%
Selling, general, and administrative expenses:        
Selling, general, and administrative expenses $ 162,857 $ 168,454 $ 354,592 $ 337,649
Selling, general, and administrative expenses (as a percent) 12.00% 12.50% 12.80% 12.60%
Divestiture-related charges     $ 39,343 $ 1,018
Operating income:        
Operating income $ 152,968 $ 127,494 $ 239,755 $ 235,004
Operating income (as a percent) 11.20% 9.50% 8.70% 8.80%
Amortization of Intangible Assets $ (22,996) $ (21,641) $ (46,031) $ (44,990)
Divestiture-related charges     (39,343) (1,018)
Operating Segments | U.S. Federal Services        
Revenue:        
Revenue 777,927 701,702 1,558,582 1,378,780
Gross profit:        
Gross profit $ 202,058 $ 163,337 $ 375,373 $ 319,999
Gross profit (as a percent) 26.00% 23.30% 24.10% 23.20%
Selling, general, and administrative expenses:        
Selling, general, and administrative expenses $ 83,076 $ 79,867 $ 157,291 $ 167,722
Selling, general, and administrative expenses (as a percent) 10.70% 11.40% 10.10% 12.20%
Operating income:        
Operating income $ 118,982 $ 83,470 $ 218,082 $ 152,277
Operating income (as a percent) 15.30% 11.90% 14.00% 11.00%
Operating Segments | U.S. Services        
Revenue:        
Revenue $ 442,350 $ 486,115 $ 894,600 $ 975,960
Gross profit:        
Gross profit $ 111,770 $ 130,122 $ 206,774 $ 248,485
Gross profit (as a percent) 25.30% 26.80% 23.10% 25.50%
Selling, general, and administrative expenses:        
Selling, general, and administrative expenses $ 57,963 $ 62,201 $ 112,121 $ 114,501
Selling, general, and administrative expenses (as a percent) 13.10% 12.80% 12.50% 11.70%
Operating income:        
Operating income $ 53,807 $ 67,921 $ 94,653 $ 133,984
Operating income (as a percent) 12.20% 14.00% 10.60% 13.70%
Operating Segments | Outside the U.S.        
Revenue:        
Revenue $ 141,509 $ 160,540 $ 311,279 $ 320,658
Gross profit:        
Gross profit $ 24,993 $ 24,130 $ 58,231 $ 49,159
Gross profit (as a percent) 17.70% 15.00% 18.70% 15.30%
Selling, general, and administrative expenses:        
Selling, general, and administrative expenses $ 20,197 $ 23,460 $ 45,315 $ 48,601
Selling, general, and administrative expenses (as a percent) 14.30% 14.60% 14.60% 15.20%
Operating income:        
Operating income $ 4,796 $ 670 $ 12,916 $ 558
Operating income (as a percent) 3.40% 0.40% 4.10% 0.20%
Segment Reconciling Items        
Selling, general, and administrative expenses:        
Selling, general, and administrative expenses $ 619 $ 2,926 $ 522 $ 5,807
Divestiture-related charges 1,002 0 39,343 1,018
Operating income:        
Amortization of Intangible Assets (22,996) (21,641) (46,031) (44,990)
Divestiture-related charges (1,002) 0 (39,343) (1,018)
Other $ (619) $ (2,926) $ (522) $ (5,807)