Revenue - Disaggregation of Revenue by Revenue Source and Pattern of Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Revenues	$ 222,111	$ 169,341
Over Time
Disaggregation of Revenue [Line Items]
Revenues	221,110	168,019
Point In Time
Disaggregation of Revenue [Line Items]
Revenues	1,001	1,322
Services
Disaggregation of Revenue [Line Items]
Revenues	221,434	168,730
Services | Over Time
Disaggregation of Revenue [Line Items]
Revenues	221,110	168,019
Services | Point In Time
Disaggregation of Revenue [Line Items]
Revenues	324	711
Professional services
Disaggregation of Revenue [Line Items]
Revenues	219,164	164,902
Professional services | Over Time
Disaggregation of Revenue [Line Items]
Revenues	219,164	164,902
Professional services | Point In Time
Disaggregation of Revenue [Line Items]
Revenues	0	0
Professional services | Time and materials contracts
Disaggregation of Revenue [Line Items]
Revenues	171,629	128,591
Professional services | Time and materials contracts | Over Time
Disaggregation of Revenue [Line Items]
Revenues	171,629	128,591
Professional services | Time and materials contracts | Point In Time
Disaggregation of Revenue [Line Items]
Revenues	0	0
Professional services | Fixed fee percent complete contracts
Disaggregation of Revenue [Line Items]
Revenues	14,369	11,580
Professional services | Fixed fee percent complete contracts | Over Time
Disaggregation of Revenue [Line Items]
Revenues	14,369	11,580
Professional services | Fixed fee percent complete contracts | Point In Time
Disaggregation of Revenue [Line Items]
Revenues	0	0
Professional services | Fixed fee contracts
Disaggregation of Revenue [Line Items]
Revenues	31,207	22,477
Professional services | Fixed fee contracts | Over Time
Disaggregation of Revenue [Line Items]
Revenues	31,207	22,477
Professional services | Fixed fee contracts | Point In Time
Disaggregation of Revenue [Line Items]
Revenues	0	0
Professional services | Reimbursable expenses
Disaggregation of Revenue [Line Items]
Revenues	1,959	2,254
Professional services | Reimbursable expenses | Over Time
Disaggregation of Revenue [Line Items]
Revenues	1,959	2,254
Professional services | Reimbursable expenses | Point In Time
Disaggregation of Revenue [Line Items]
Revenues	0	0
Other services
Disaggregation of Revenue [Line Items]
Revenues	2,270	3,828
Other services | Over Time
Disaggregation of Revenue [Line Items]
Revenues	1,946	3,117
Other services | Point In Time
Disaggregation of Revenue [Line Items]
Revenues	324	711
Software and hardware
Disaggregation of Revenue [Line Items]
Revenues	677	611
Software and hardware | Over Time
Disaggregation of Revenue [Line Items]
Revenues	0	0
Software and hardware | Point In Time
Disaggregation of Revenue [Line Items]
Revenues	$ 677	$ 611