Accounts Receivable and Allowance for Expected Credit Losses (Tables)

9 Months Ended

Sep. 30, 2021

Allowance for Doubtful Accounts and Unbilled Services [Abstract]

Schedule of Accounts Receivable

The following table summarizes the components of "Accounts receivable, net" as presented on the Condensed Consolidated Balance Sheets:

	September 30, 2021		December 31, 2020
Accounts receivable:
Billed receivables	$	560,046	$	513,459
Unbilled receivables	290,352		236,285
Allowance for expected credit losses	(40,520)		(38,387)
Accounts receivable, net	$	809,878	$	711,357

Schedule of Accounts Receivable, Writeoff

The following table summarizes the total provision for expected credit losses and write-offs:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Provision for expected credit losses (1)	$	6,580	$	3,984	$	14,816	$	15,608
Write-offs	$	5,746	$	6,182	$	15,464	$	19,707

(1)    Adjustments to the allowance for expected credit losses are recorded to selling, general & administrative ("SG&A") expenses on the Condensed Consolidated Statements of Comprehensive Income.