EMPLOYEE RETIREMENT PLANS (Details 4) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Benefits earned during the period		$ 1,638	$ 1,636	$ 1,263
Interest cost on projected benefit obligation	[1]	2,449	2,665	2,586
Expected return on plan assets		(2,430)	(2,364)	(2,343)
Net amortization and deferral		1,527	1,762	706
Net pension expense		$ 3,184	$ 3,699	$ 2,212

[1] The decrease in interest cost in 2016 was primarily due to the adoption of the spot-rate approach, as described above.