RETIREMENT PLANS (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Pension Plan [Member]
Components of net periodic benefit cost: [Abstract]
Service cost	$ 3,673,000	$ 2,660,000	$ 11,020,000	$ 7,983,000
Interest cost	3,327,000	3,208,000	9,983,000	9,629,000
Expected return on plan assets	(4,481,000)	(4,712,000)	(13,449,000)	(14,143,000)
Amortization of actuarial loss	1,932,000	175,000	5,799,000	526,000
Net periodic benefit cost	4,451,000	1,331,000	13,353,000	3,995,000
Pension Plan [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan of asset contributions to pension plan obligations	10,000,000		10,000,000
SERP [Member]
Components of net periodic benefit cost: [Abstract]
Service cost	0	0	0	0
Interest cost	16,000	18,000	48,000	55,000
Expected return on plan assets	0	0	0	0
Amortization of actuarial loss	7,000	4,000	21,000	12,000
Net periodic benefit cost	23,000	22,000	$ 69,000	67,000
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan defined benefit plan cost increase limit percentage			4.00%
Components of net periodic benefit cost: [Abstract]
Service cost	0	0	$ 0	0
Interest cost	9,000	27,000	27,000	82,000
Amortization of actuarial loss	(199,000)	(162,000)	(594,000)	(486,000)
Net periodic benefit cost	$ (190,000)	$ (135,000)	$ (567,000)	$ (404,000)