EMPLOYEE BENEFITS (Tables)

6 Months Ended

Jun. 30, 2014

Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]

Net Periodic Benefit Costs Charged to Operating Expenses

The net periodic benefit costs charged to operating expenses, which are valued at the measurement date of January 1 and recognized evenly throughout the year, consisted of the following components (in thousands of dollars):

	Three Months Ended June 30,						Six Months Ended June 30,
	2014			2013			2014			2013
Service cost	$	2,252		$	2,567		$	4,503		$	5,294
Interest cost	2,637			2,119			5,274			4,469
Expected return on assets	(2,060		)	(1,769		)	(4,119		)	(3,538		)
Amortization of transition asset	(35		)	(36		)	(71		)	(71		)
Amortization of unrecognized losses	195			746			390			1,862
Amortization of prior service credits	(1,814		)	(1,852		)	(3,627		)	(3,705		)
Net periodic benefit costs	$	1,175		$	1,775		$	2,350		$	4,311