Contract Receivables, Net - Summary of Contract Receivables, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Receivables [Abstract]
Billed and billable	$ 223,791	$ 230,466
Allowance for expected credit losses	(8,468)	(7,616)
Contract receivables, net	$ 215,323	$ 222,850

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Balance Type:	debit
Period Type:	instant