STOCKHOLDERS' EQUITY (Details Narrative) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2016		Mar. 31, 2015	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash dividend paid	$ 21,855		$ 17,483
Cash dividend per share (in dollars per share)	$ 0.10		$ 0.08
Number of shares repurchased (in shares)	54,000	[1]	19,000
Par value of common stock (in dollars per share)	$ 1			$ 1
Weighted average stock price of shares repurchased (in dollars per share)	$ 24.77		$ 22.42
Repurchase of common stock from employees	$ 7,400		$ 6,100
Tax benefits from share-based payments	3,000		$ 2,300	$ 1,900
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 40,900			$ 31,300
Unrecognized compensation cost, period for recognition	4 years 3 months 18 days			3 years 9 months 24 days

[1] Charges to Retained Earnings are from purchases of the Company's Common Stock.