PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Tables)

6 Months Ended

Jun. 30, 2013

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS

Summary of the components of net periodic benefit cost

	Three Months Ended June 30
	Nonunion Defined						Supplemental				Postretirement
	Benefit Pension Plan						Benefit Pension Plan				Health Benefit Plan
	2013			2012			2013		2012		2013			2012
	(in thousands)
Service cost	$	2,367		$	2,297		$	—	$	—	$	83		$	78
Interest cost	1,922			2,173			38		53		187			188
Expected return on plan assets	(3,155		)	(3,016		)	—		—		—			—
Amortization of prior service credit	—			—			—		—		(47		)	(47		)
Amortization of net actuarial loss and other	2,714			2,692			65		50		133			104
Net periodic benefit cost	$	3,848		$	4,146		$	103	$	103	$	356		$	323

	Six Months Ended June 30
	Nonunion Defined						Supplemental				Postretirement
	Benefit Pension Plan						Benefit Pension Plan				Health Benefit Plan
	2013			2012			2013		2012		2013			2012
	(in thousands)
Service cost	$	4,734		$	4,594		$	—	$	—	$	166		$	157
Interest cost	3,845			4,346			75		105		375			375
Expected return on plan assets	(6,309		)	(6,032		)	—		—		—			—
Amortization of prior service credit	—			—			—		—		(95		)	(95		)
Amortization of net actuarial loss and other	5,427			5,384			130		101		267			208
Net periodic benefit cost	$	7,697		$	8,292		$	205	$	206	$	713		$	645

Schedule of changes in the PBO, plan assets, funded status, and accumulated benefit obligation of nonunion defined benefit pension plan

	Nonunion Defined
	Benefit Pension Plan
	(in thousands)
Change in projected benefit obligation
Projected benefit obligation at December 31, 2012	$	260,950
Service cost	4,734
Interest cost	3,845
Actuarial gain and other(1)	(10,747		)
Benefits paid	(10,745		)
Curtailment	(29,262		)
Projected benefit obligation at June 30, 2013	218,775
Change in plan assets
Fair value of plan assets at December 31, 2012	181,225
Actual return on plan assets	12,575
Employer contributions	9,000
Benefits paid	(10,745		)
Fair value of plan assets at June 30, 2013	192,055
Funded status at June 30, 2013(2)	$	(26,720	)
Accumulated benefit obligation	$	218,775

(1) Net actuarial gain from remeasurement upon curtailment was impacted by an actual return on plan assets during the first six months of 2013 that exceeded the assumed annualized return rate of 7.5% combined with an increase in discount rates since the last measurement date. The discount rate used to remeasure the PBO was 3.9% compared to a rate of 3.1% as of the December 31, 2012 measurement date.

(2) Noncurrent liability recognized within pension and postretirement liabilities in the accompanying consolidated balance sheet at June 30, 2013.