Trade Accounts Receivable, Net Of Allowances

12 Months Ended

Dec. 31, 2011

Trade Accounts Receivable, Net Of Allowances [Abstract]

Trade Accounts Receivable, Net Of Allowances

7. TRADE ACCOUNTS RECEIVABLE, NET OF ALLOWANCES

Unbilled trade accounts receivable relate to services earned under time and material arrangements, maintenance and license arrangements that had not been invoiced as of December 31, 2011 and December 31, 2010, respectively.

(in thousands)	December 31, 2011			December 31, 2010
Trade accounts receivable	$	77,123		$	65,373
Unbilled accounts receivable		22,096			15,682
Total accounts receivable		99,219			81,055
Allowance for sales credit memos		(895	)		(1,027	)
Allowance for doubtful accounts		(31	)		(132	)
Total allowance		(926	)		(1,159	)
	$	98,293		$	79,896

The Company records an allowance for estimates of potential sales credit memos when the related revenue is recorded and reviews this allowance periodically. The following reflects the activity of the allowance for sales credit memos for each of three years ended December 31:

(in thousands)	2011			2010			2009
Balance at beginning of year	$	1,027		$	540		$	1,125
Provision for credit memos		2,877			3,050			2,600
Credit memos issued		(3,009	)		(2,563	)		(3,185	)
	$	895		$	1,027		$	540