TRADE ACCOUNTS RECEIVABLE, NET OF ALLOWANCE

9 Months Ended

Sep. 30, 2014

TRADE ACCOUNTS RECEIVABLE, NET OF ALLOWANCE

6.    TRADE ACCOUNTS RECEIVABLE, NET OF ALLOWANCE

(in thousands)	September 30,             2014		December 31,             2013
Trade accounts receivable	$	79,717	$	129,020
Unbilled trade accounts receivable		25,311		38,618
Total accounts receivable		105,028		167,638
Allowance for sales credit memos		(1,589)		(1,997)
	$	103,439	$	165,641

Unbilled trade accounts receivable primarily related to services revenue earned under time and material arrangements, and maintenance and license arrangements that had not been invoiced.