EMPLOYEE BENEFIT PLANS (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Other changes in plan assets and benefit obligations recognized in accumulated other comprehensive income:
Total adjustments	$ (1,804)	$ (21,739)	$ (1,572)
Pension Plan
Components of net periodic benefit cost:
Service cost	2,682	2,312	2,214
Interest cost	3,246	3,184	2,924
Expected return on plan assets	(3,882)	(3,877)	(3,270)
Amortization of net loss	1,788	537	366
Net periodic benefit cost	3,834	2,156	2,234
Other changes in plan assets and benefit obligations recognized in accumulated other comprehensive income:
Net actuarial gain (loss)	(6,524)	(17,483)	5,110
Reversal of amortization item, net actuarial (gain) loss	1,788	537	366
Total adjustments	(4,736)	(16,946)	5,476
Net periodic benefit cost	(3,834)	(2,156)	(2,234)
Total recognized in net periodic benefit cost and accumulated other comprehensive loss	$ 8,570	$ 19,102