POSTRETIREMENT MEDICAL BENEFITS AND PENSION (Tables)

9 Months Ended

Sep. 30, 2016

Postretirement Medical Benefits

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

Components of net periodic benefit cost

The components of net periodic postretirement medical benefit cost are as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
	(In thousands)
Components of net periodic benefit cost:
Service cost	$	763	$	1,054	$	2,507	$	3,163
Interest cost	3,075		2,907		9,278		8,722
Amortization of deferred items	368		327		891		981
Total net periodic benefit cost	$	4,206	$	4,288	$	12,676	$	12,866

The following table shows the net periodic postretirement medical benefit costs that relate to current and former mining operations:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
	(In thousands)
Former mining operations	$	2,135	$	2,034	$	6,405	$	6,103
Current operations	2,071		2,254		6,271		6,763
Total net periodic benefit cost	$	4,206	$	4,288	$	12,676	$	12,866

Pension

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

Components of net periodic benefit cost

The Company incurred net periodic benefit costs of providing these pension benefits as follows:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2016			2015			2016			2015
	(In thousands)
Components of net periodic benefit cost:
Service cost	$	373		$	436		$	1,242		$	1,318
Interest cost	2,564			1,831			7,926			5,780
Expected return on plan assets	(3,349		)	(2,435		)	(10,390		)	(7,744		)
Settlements	247			(1,529		)	247			(1,874		)
Amortization of deferred items	1,294			1,059			3,884			3,301
Total net periodic pension cost	$	1,129		$	(638	)	$	2,909		$	781