Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Total	$ 97,850	$ 72,738
Prime Contractor
Disaggregation of Revenue [Line Items]
Total	87,633	67,981
Subcontractor
Disaggregation of Revenue [Line Items]
Total	10,217	4,757
Time and Materials
Disaggregation of Revenue [Line Items]
Total	54,789	48,991
Cost Reimbursable
Disaggregation of Revenue [Line Items]
Total	19,751	12,580
Firm Fixed Price
Disaggregation of Revenue [Line Items]
Total	23,310	11,167
Department of Health and Human Services | Revenue from Contract with Customer | Customer concentration
Disaggregation of Revenue [Line Items]
Total	44,297	27,305
Department of Veterans Affairs | Revenue from Contract with Customer | Customer concentration
Disaggregation of Revenue [Line Items]
Total	34,680	33,708
Department of Defense | Revenue from Contract with Customer | Customer concentration
Disaggregation of Revenue [Line Items]
Total	16,871	10,263
Other | Revenue from Contract with Customer | Customer concentration
Disaggregation of Revenue [Line Items]
Total	$ 2,002	$ 1,462