Quarterly report pursuant to Section 13 or 15(d)

Revenue Recognition - Disaggregation of Revenue (Details)

v3.19.1
Revenue Recognition - Disaggregation of Revenue (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Mar. 31, 2019
Mar. 31, 2018
Disaggregation of Revenue [Line Items]        
Revenue $ 736,520 $ 612,787 $ 1,401,139 $ 1,235,935
United States of America        
Disaggregation of Revenue [Line Items]        
Revenue 580,473   1,091,673  
United Kingdom        
Disaggregation of Revenue [Line Items]        
Revenue 78,334   151,752  
Australia        
Disaggregation of Revenue [Line Items]        
Revenue 50,997   104,370  
Rest of world        
Disaggregation of Revenue [Line Items]        
Revenue 26,716   53,344  
Total U.S. state government agencies        
Disaggregation of Revenue [Line Items]        
Revenue 287,728   578,342  
New York State government agencies        
Disaggregation of Revenue [Line Items]        
Revenue 89,858   181,570  
Other U.S. state government agencies        
Disaggregation of Revenue [Line Items]        
Revenue 197,870   396,772  
United States Federal Government agencies        
Disaggregation of Revenue [Line Items]        
Revenue 270,623   468,901  
International government agencies        
Disaggregation of Revenue [Line Items]        
Revenue 146,292   289,073  
Other, including local municipalities and commercial customers        
Disaggregation of Revenue [Line Items]        
Revenue 31,877   64,823  
Performance-based        
Disaggregation of Revenue [Line Items]        
Revenue 261,592   574,479  
Cost-plus        
Disaggregation of Revenue [Line Items]        
Revenue 298,133   473,431  
Fixed price        
Disaggregation of Revenue [Line Items]        
Revenue 139,871   287,022  
Time and materials        
Disaggregation of Revenue [Line Items]        
Revenue 36,924   66,207  
U.S. Health & Human Services        
Disaggregation of Revenue [Line Items]        
Revenue 290,737   584,950  
U.S. Federal Services        
Disaggregation of Revenue [Line Items]        
Revenue 289,736   506,723  
Outside the U.S.        
Disaggregation of Revenue [Line Items]        
Revenue 156,047   309,466  
Program administration | U.S. Health & Human Services        
Disaggregation of Revenue [Line Items]        
Revenue 219,732   438,705  
Program administration | U.S. Federal Services        
Disaggregation of Revenue [Line Items]        
Revenue 209,996   350,117  
Program administration | Outside the U.S.        
Disaggregation of Revenue [Line Items]        
Revenue 15,922   31,242  
Assessments and appeals | U.S. Health & Human Services        
Disaggregation of Revenue [Line Items]        
Revenue 33,331   70,552  
Assessments and appeals | U.S. Federal Services        
Disaggregation of Revenue [Line Items]        
Revenue 41,747   79,730  
Assessments and appeals | Outside the U.S.        
Disaggregation of Revenue [Line Items]        
Revenue 67,771   130,081  
Workforce and children services | U.S. Health & Human Services        
Disaggregation of Revenue [Line Items]        
Revenue 23,898   47,801  
Workforce and children services | Outside the U.S.        
Disaggregation of Revenue [Line Items]        
Revenue 69,759   143,037  
Other | U.S. Health & Human Services        
Disaggregation of Revenue [Line Items]        
Revenue 13,776   27,892  
Other | Outside the U.S.        
Disaggregation of Revenue [Line Items]        
Revenue 2,595   5,106  
Technology solutions | U.S. Federal Services        
Disaggregation of Revenue [Line Items]        
Revenue $ 37,993   $ 76,876