TRADE ACCOUNTS RECEIVABLE, NET OF ALLOWANCE (Tables)

6 Months Ended

Jun. 30, 2017

Schedule of Trade Accounts Receivable

(in thousands)	June 30, 2017			December 31, 2016
Trade accounts receivable	$	188,304		$	234,473
Unbilled trade accounts receivable		34,306			34,681
Total accounts receivable		222,610			269,154
Allowance for sales credit memos		(5,590	)		(4,126	)
	$	217,020		$	265,028