RECEIVABLES (Tables)

9 Months Ended

Sep. 30, 2017

Receivables [Abstract]

Summary of Accounts Receivable

A summary of accounts receivable as of September 30, 2017 and December 31, 2016 is as follows (in thousands):

	September 30, 2017			December 31, 2016
	(unaudited)
Trade accounts receivable	$	194,722		$	230,889
Unbilled revenues	99,943			39,719
Allowance for doubtful accounts	(12,709		)	(7,835		)
Total	$	281,956		$	262,773