Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Revenue	$ 395,937	$ 375,872
Prime Contractor
Disaggregation of Revenue [Line Items]
Revenue	355,147	356,792
Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	40,790	19,080
Time and Materials
Disaggregation of Revenue [Line Items]
Revenue	215,341	209,951
Cost Reimbursable
Disaggregation of Revenue [Line Items]
Revenue	79,481	81,797
Firm Fixed Price
Disaggregation of Revenue [Line Items]
Revenue	101,115	84,124
Department of Health and Human Services | Revenue Concentration | Customer Concentration
Disaggregation of Revenue [Line Items]
Revenue	184,544	161,311
Department of Veterans Affairs | Revenue Concentration | Customer Concentration
Disaggregation of Revenue [Line Items]
Revenue	139,945	138,862
Department of Defense | Revenue Concentration | Customer Concentration
Disaggregation of Revenue [Line Items]
Revenue	64,128	70,325
Other | Revenue Concentration | Customer Concentration
Disaggregation of Revenue [Line Items]
Revenue	$ 7,320	$ 5,374