RECEIVABLES (Tables)

9 Months Ended

Sep. 30, 2019

Receivables [Abstract]

Summary of Accounts Receivable

A summary of accounts receivable as of September 30, 2019 and December 31, 2018 is as follows (in thousands):

	September 30, 2019			December 31, 2018
	(unaudited)
Trade accounts receivable	$	178,745		$	207,266
Unbilled receivables	97,342			76,268
Allowance for doubtful accounts	(12,582		)	(15,182		)
Total	$	263,505		$	268,352