Accounts Receivable (Tables)

9 Months Ended

Sep. 30, 2019

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, 2019 and December 31, 2018 (in thousands):

	September 30, 2019			December 31, 2018
Trade accounts receivable	$	357,050		$	337,445
Unbilled accounts receivable	161,352			143,978
Gross accounts receivable	518,402			481,423
Allowance for doubtful accounts and other reserves	(1,745		)	(1,534		)
Accounts receivable, net	$	516,657		$	479,889