ACCOUNTS RECEIVABLE AND SIGNIFICANT CLIENTS (TABLES)

12 Months Ended

Dec. 31, 2017

ACCOUNTS RECEIVABLE AND SIGNIFICANT CLIENTS [Abstract]

Schedule of Accounts Receivable

Accounts receivable, net in the accompanying Consolidated Balance Sheets consists of the following (in thousands):

	December 31,
	2017		2016
Accounts receivable	$	386,672	$	301,470
Less: Allowance for doubtful accounts		(921)		(662)
Accounts receivable, net	$	385,751	$	300,808

Schedule of Change in Allowance for Doubtful Accounts

Activity in the Company’s Allowance for doubtful accounts consists of the following (in thousands):

	December 31,
	2017		2016		2015
Balance, beginning of year	$	662	$	2,176	$	3,425
Provision for doubtful accounts		458		1,164		1,465
Uncollectible receivables written-off		(180)		(2,670)		(2,035)
Effect of foreign currency and other		(19)		(8)		(679)
Balance, end of year	$	921	$	662	$	2,176

Schedule of Revenue from Significant Clients

	Year Ended December 31,
	2017		2016		2015
Telecommunications client	9	%	10	%	10	%

Schedule of Accounts Receivable Outstanding from Significant Clients

Accounts receivable from this client was as follows (in thousands):

	Year Ended December 31,
	2017		2016		2015
Telecommunications client	$	26,920	$	28,080	$	23,953