EMPLOYEE BENEFITS - POSTRETIREMENT (Tables)

6 Months Ended

Jun. 30, 2017

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

Schedule of 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,
	2017			2016			2017			2016
Service cost	$	1,897		$	2,060		$	3,794		$	4,119
Interest cost	2,148			2,463			4,297			4,927
Expected return on assets	(2,857		)	(2,528		)	(5,714		)	(5,056		)
Amortization of unrecognized (gains) losses	(656		)	32			(1,311		)	64
Amortization of prior service credits	(1,622		)	(1,672		)	(3,244		)	(3,344		)
Net periodic (benefits) costs	$	(1,090	)	$	355		$	(2,178	)	$	710