Contracts with Customers - Summary of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation Of Revenue [Line Items]
Revenues	$ 949,069	$ 874,697
Fixed-Price
Disaggregation Of Revenue [Line Items]
Revenues	240,574	229,942
Time-and-Materials
Disaggregation Of Revenue [Line Items]
Revenues	263,315	239,665
Cost-Plus
Disaggregation Of Revenue [Line Items]
Revenues	$ 445,180	$ 405,090