Quarterly report pursuant to Section 13 or 15(d)

Revenue Recognition - Disaggregation of Revenue (Details)

v3.21.1
Revenue Recognition - Disaggregation of Revenue (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Mar. 31, 2021
Mar. 31, 2020
Disaggregation of Revenue [Line Items]        
Revenue $ 959,280 $ 818,135 $ 1,904,834 $ 1,636,364
United States        
Disaggregation of Revenue [Line Items]        
Revenue 778,350 702,089 1,568,529 1,380,941
United Kingdom        
Disaggregation of Revenue [Line Items]        
Revenue 72,882 63,722 137,668 136,724
Australia        
Disaggregation of Revenue [Line Items]        
Revenue 70,947 24,540 126,878 61,975
Rest of world        
Disaggregation of Revenue [Line Items]        
Revenue 37,101 27,784 71,759 56,724
Total U.S. state government agencies        
Disaggregation of Revenue [Line Items]        
Revenue 445,697 317,417 833,811 624,526
New York State government agencies        
Disaggregation of Revenue [Line Items]        
Revenue 111,911 100,222 187,267 197,445
Other U.S. state government agencies        
Disaggregation of Revenue [Line Items]        
Revenue 333,786 217,195 646,544 427,081
U.S. Federal Government agencies        
Disaggregation of Revenue [Line Items]        
Revenue 307,870 374,909 693,442 726,742
International government agencies        
Disaggregation of Revenue [Line Items]        
Revenue 171,700 107,460 319,042 238,276
Other, including local municipalities and commercial customers        
Disaggregation of Revenue [Line Items]        
Revenue 34,013 18,349 58,539 46,820
Performance-based        
Disaggregation of Revenue [Line Items]        
Revenue 349,749 275,669 643,709 568,427
Cost-plus        
Disaggregation of Revenue [Line Items]        
Revenue 286,082 398,973 670,565 761,784
Fixed price        
Disaggregation of Revenue [Line Items]        
Revenue 146,344 100,504 267,121 219,720
Time and materials        
Disaggregation of Revenue [Line Items]        
Revenue 177,105 42,989 323,439 86,433
U.S. Services        
Disaggregation of Revenue [Line Items]        
Revenue 448,215 308,698 833,149 620,979
U.S. Federal Services        
Disaggregation of Revenue [Line Items]        
Revenue 330,136 393,391 735,381 759,962
Outside the U.S.        
Disaggregation of Revenue [Line Items]        
Revenue 180,929 116,046 336,304 255,423
Program administration | U.S. Services        
Disaggregation of Revenue [Line Items]        
Revenue 345,383 236,436 639,227 473,343
Program administration | U.S. Federal Services        
Disaggregation of Revenue [Line Items]        
Revenue 226,322 304,367 554,112 586,055
Program administration | Outside the U.S.        
Disaggregation of Revenue [Line Items]        
Revenue 22,932 16,945 45,988 34,039
Technology solutions | U.S. Federal Services        
Disaggregation of Revenue [Line Items]        
Revenue 62,784 44,508 97,448 88,114
Assessments and appeals | U.S. Services        
Disaggregation of Revenue [Line Items]        
Revenue 35,416 29,916 68,031 63,747
Assessments and appeals | U.S. Federal Services        
Disaggregation of Revenue [Line Items]        
Revenue 41,030 44,516 83,821 85,793
Assessments and appeals | Outside the U.S.        
Disaggregation of Revenue [Line Items]        
Revenue 57,966 62,286 111,089 124,929
Workforce and children services | U.S. Services        
Disaggregation of Revenue [Line Items]        
Revenue 55,045 28,734 102,866 58,120
Workforce and children services | Outside the U.S.        
Disaggregation of Revenue [Line Items]        
Revenue 97,971 34,683 175,433 91,922
Other | U.S. Services        
Disaggregation of Revenue [Line Items]        
Revenue 12,371 13,612 23,025 25,769
Other | Outside the U.S.        
Disaggregation of Revenue [Line Items]        
Revenue $ 2,060 $ 2,132 $ 3,794 $ 4,533