ACCOUNTS RECEIVABLE (SCHEDULE OF CHANGE IN ALLOWANCE) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
ACCOUNTS RECEIVABLE AND SIGNIFICANT CLIENTS [Abstract]
Balance, beginning of year	$ 5,452	$ 5,592	$ 921
Provision for credit losses	494	1,711	3,679
Uncollectible receivables written-off	(880)	(1,311)	(429)
Effect of foreign currency	1	(540)	1,421
Balance, end of year	$ 5,067	$ 5,452	$ 5,592