Accounts Receivable (Tables)

9 Months Ended

Sep. 30, 2021

Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]

Schedule of Accounts Receivable

Net accounts receivable consisted of the following as of September 30, 2021 and December 31, 2020 (in thousands):

 

	September 30, 2021		December 31, 2020
Trade accounts receivable	$	479,267	$	473,474
Unbilled accounts receivable	183,093		188,400
Gross accounts receivable	662,360		661,874
Allowances for current expected credit losses and other reserves	(2,268)		(1,822)
Accounts receivable, net	$	660,092	$	660,052

Summary of Allowance for Credit Loss Activity

The following table summarizes the activity of the Company's allowance for current expected credit losses and other reserves during the nine months ended September 30, 2021 and 2020 (in thousands):

	September 30, 2021		September 30, 2020
Beginning balance	$	1,822	$	1,880
Charges to income from operations	3,510		10,354
Collections from customers previously reserved and other	(3,064)		(8,538)
Ending balance	$	2,268	$	3,696