Quarterly report [Sections 13 or 15(d)]

Revenue Recognition - Disaggregation of Revenue (Details)

v3.25.4
Revenue Recognition - Disaggregation of Revenue (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disaggregation of Revenue [Line Items]    
Revenue $ 1,345,046 $ 1,402,675
New York state government agencies    
Disaggregation of Revenue [Line Items]    
Revenue $ 150,121 $ 161,695
New York state government agencies | Revenue Benchmark | Customer Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 11.20% 11.50%
Other U.S. state government agencies    
Disaggregation of Revenue [Line Items]    
Revenue $ 268,472 $ 291,067
Other U.S. state government agencies | Revenue Benchmark | Customer Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 20.00% 20.80%
Total U.S. state government agencies    
Disaggregation of Revenue [Line Items]    
Revenue $ 418,593 $ 452,762
U.S. federal government agencies    
Disaggregation of Revenue [Line Items]    
Revenue $ 767,803 $ 764,437
U.S. federal government agencies | Revenue Benchmark | Customer Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 57.10% 54.50%
International government agencies    
Disaggregation of Revenue [Line Items]    
Revenue $ 141,012 $ 166,866
International government agencies | Revenue Benchmark | Customer Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 10.50% 11.90%
Other, including local municipalities and commercial customers    
Disaggregation of Revenue [Line Items]    
Revenue $ 17,638 $ 18,610
Other, including local municipalities and commercial customers | Revenue Benchmark | Customer Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 1.30% 1.30%
Performance-based    
Disaggregation of Revenue [Line Items]    
Revenue $ 720,661 $ 717,771
Performance-based | Revenue Benchmark | Contract Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 53.60% 51.20%
Cost-plus    
Disaggregation of Revenue [Line Items]    
Revenue $ 386,388 $ 384,427
Cost-plus | Revenue Benchmark | Contract Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 28.70% 27.40%
Fixed price    
Disaggregation of Revenue [Line Items]    
Revenue $ 168,519 $ 174,679
Fixed price | Revenue Benchmark | Contract Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 12.50% 12.50%
Time and materials    
Disaggregation of Revenue [Line Items]    
Revenue $ 69,478 $ 125,798
Time and materials | Revenue Benchmark | Contract Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 5.20% 9.00%
Program Operations    
Disaggregation of Revenue [Line Items]    
Revenue $ 676,407 $ 727,967
Program Operations | Revenue Benchmark | Contract Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 50.30% 51.90%
Clinical Services    
Disaggregation of Revenue [Line Items]    
Revenue $ 523,719 $ 471,526
Clinical Services | Revenue Benchmark | Contract Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 38.90% 33.60%
Employment & Other    
Disaggregation of Revenue [Line Items]    
Revenue $ 70,165 $ 113,618
Employment & Other | Revenue Benchmark | Contract Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 5.20% 8.10%
Technology Solutions    
Disaggregation of Revenue [Line Items]    
Revenue $ 74,755 $ 89,564
Technology Solutions | Revenue Benchmark | Contract Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 5.60% 6.40%