EMPLOYEE BENEFITS (Details 3) - USD ($)
$ in Thousands |
12 Months Ended |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
| Pension Plan [Member] |
|
|
|
| Components of net periodic benefit cost (credit) |
|
|
|
| Service cost |
$ 1,953
|
$ 1,421
|
$ 1,401
|
| Interest cost |
6,676
|
8,426
|
7,380
|
| Expected return on plan assets |
(9,555)
|
(9,892)
|
(9,464)
|
| Amortization of prior service credit |
(318)
|
(399)
|
(393)
|
| Amortization of transition asset |
(258)
|
(276)
|
(272)
|
| Settlement loss |
16
|
810
|
229
|
| Special termination benefits |
235
|
0
|
0
|
| Curtailment gain |
0
|
(409)
|
0
|
| Amortization of loss (gain) |
3,273
|
1,719
|
3,223
|
| Net periodic cost (benefit) |
2,022
|
1,400
|
2,104
|
| Other Postretirement Benefit Plan [Member] |
|
|
|
| Components of net periodic benefit cost (credit) |
|
|
|
| Service cost |
12
|
11
|
18
|
| Interest cost |
74
|
87
|
92
|
| Expected return on plan assets |
0
|
0
|
0
|
| Amortization of prior service credit |
0
|
0
|
(254)
|
| Amortization of transition asset |
0
|
0
|
0
|
| Settlement loss |
0
|
0
|
0
|
| Special termination benefits |
0
|
0
|
0
|
| Curtailment gain |
0
|
0
|
0
|
| Amortization of loss (gain) |
(51)
|
(57)
|
(5)
|
| Net periodic cost (benefit) |
$ 35
|
$ 41
|
$ (149)
|