Quarterly report pursuant to Section 13 or 15(d)

Revenue Recognition - Disaggregation of Revenue (Details)

v3.25.0.1
Revenue Recognition - Disaggregation of Revenue (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Disaggregation of Revenue [Line Items]    
Revenue $ 1,402,675 $ 1,327,041
Program Operations    
Disaggregation of Revenue [Line Items]    
Revenue 727,967 687,370
Clinical Services    
Disaggregation of Revenue [Line Items]    
Revenue 471,526 428,369
Employment & Other    
Disaggregation of Revenue [Line Items]    
Revenue 113,618 118,288
Technology Solutions    
Disaggregation of Revenue [Line Items]    
Revenue $ 89,564 $ 93,014
Revenue Benchmark | Contract Concentration Risk | Program Operations    
Disaggregation of Revenue [Line Items]    
Revenue in % 51.90% 51.80%
Revenue Benchmark | Contract Concentration Risk | Clinical Services    
Disaggregation of Revenue [Line Items]    
Revenue in % 33.60% 32.30%
Revenue Benchmark | Contract Concentration Risk | Employment & Other    
Disaggregation of Revenue [Line Items]    
Revenue in % 8.10% 8.90%
Revenue Benchmark | Contract Concentration Risk | Technology Solutions    
Disaggregation of Revenue [Line Items]    
Revenue in % 6.40% 7.00%
New York state government agencies    
Disaggregation of Revenue [Line Items]    
Revenue $ 161,695 $ 160,534
New York state government agencies | Revenue Benchmark | Customer Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 11.50% 12.10%
Other U.S. state government agencies    
Disaggregation of Revenue [Line Items]    
Revenue $ 291,067 $ 326,409
Other U.S. state government agencies | Revenue Benchmark | Customer Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 20.80% 24.60%
Total U.S. state government agencies    
Disaggregation of Revenue [Line Items]    
Revenue $ 452,762 $ 486,943
U.S. federal government agencies    
Disaggregation of Revenue [Line Items]    
Revenue $ 764,437 $ 662,946
U.S. federal government agencies | Revenue Benchmark | Customer Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 54.50% 50.00%
International government agencies    
Disaggregation of Revenue [Line Items]    
Revenue $ 166,866 $ 155,612
International government agencies | Revenue Benchmark | Customer Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 11.90% 11.70%
Other, including local municipalities and commercial customers    
Disaggregation of Revenue [Line Items]    
Revenue $ 18,610 $ 21,540
Other, including local municipalities and commercial customers | Revenue Benchmark | Customer Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 1.30% 1.60%
Performance-based    
Disaggregation of Revenue [Line Items]    
Revenue $ 717,771 $ 704,711
Performance-based | Revenue Benchmark | Contract Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 51.20% 53.10%
Cost-plus    
Disaggregation of Revenue [Line Items]    
Revenue $ 384,427 $ 342,015
Cost-plus | Revenue Benchmark | Contract Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 27.40% 25.80%
Fixed price    
Disaggregation of Revenue [Line Items]    
Revenue $ 174,679 $ 176,677
Fixed price | Revenue Benchmark | Contract Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 12.50% 13.30%
Time and materials    
Disaggregation of Revenue [Line Items]    
Revenue $ 125,798 $ 103,638
Time and materials | Revenue Benchmark | Contract Concentration Risk    
Disaggregation of Revenue [Line Items]    
Revenue in % 9.00% 7.80%