TRADE ACCOUNTS RECEIVABLE, NET OF ALLOWANCE (Tables)

12 Months Ended

Dec. 31, 2015

Schedule of Trade Accounts Receivable

Unbilled trade accounts receivable primarily relates to services earned under time and materials arrangements and to license, maintenance, and cloud arrangements that have commenced or been delivered in excess of scheduled invoicing.

	December 31,
(in thousands)	2015			2014
Trade accounts receivable	$	190,820		$	128,757
Unbilled accounts receivable		25,657			27,627
Total accounts receivable		216,477			156,384
Allowance for sales credit memos		(4,631	)		(1,540	)
	$	211,846		$	154,844

Activity of Allowance for Sales Credit Memos

The following reflects the activity of the allowance for sales credit memos:

	Year Ended December 31,
(in thousands)	2015			2014			2013
Balance at beginning of year	$	1,540		$	1,997		$	963
Provision for credit memos		8,005			2,164			5,374
Credit memos issued		(4,914	)		(2,621	)		(4,340	)
	$	4,631		$	1,540		$	1,997