EMPLOYEE BENEFIT PLANS (Tables)

3 Months Ended

Mar. 31, 2015

Employee Benefit Plans [Line Items]

Schedule of Net Benefit Costs [Table Text Block]

The following tables set forth the components of net periodic benefit cost for our pension and other postretirement benefit plans for the periods indicated:

	Pension Benefits
	Three Months Ended			Three Months Ended
	March 31,			March 31,
	2015			2014
	(Thousands of dollars)
Components of net periodic benefit cost
Service cost	$	3,524		$	2,768
Interest cost	10,652			10,948
Expected return on assets	(15,362		)	(14,965		)
Amortization of unrecognized prior service cost	67			137
Amortization of net loss	11,055			7,550
Net periodic benefit cost	$	9,936		$	6,438

	Other Postretirement Benefits
	Three Months Ended			Three Months Ended
	March 31,			March 31,
	2015			2014
	(Thousands of dollars)
Components of net periodic benefit cost
Service cost	$	849		$	1,174
Interest cost	2,666			2,901
Expected return on assets	(2,908		)	(2,848		)
Amortization of unrecognized prior service cost	(440		)	(440		)
Amortization of net loss	1,510			992
Net periodic benefit cost	$	1,677		$	1,779