Retirement Plans and Other Post-Retirement Benefits

3 Months Ended

Mar. 31, 2015

Compensation and Retirement Disclosure [Abstract]

Retirement Plans and Other Post-Retirement Benefits

9. RETIREMENT PLANS AND OTHER POST-RETIREMENT BENEFITS

The following tables provide information with respect to the net periodic costs of our pension and post retirement medical benefit plans.

	Three months ended March 31
In thousands	2015			2014
Pension Benefits
Service cost	$	3,136		$	2,703
Interest cost		5,950			6,171
Expected return on plan assets		(11,543	)		(11,007	)
Amortization of prior service cost		760			734
Amortization of unrecognized loss		4,506			2,940
Net periodic benefit cost	$	2,809		$	1,541
Other Benefits
Service cost	$	413		$	615
Interest cost		563			598
Amortization of prior service cost		(70	)		(72	)
Amortization of unrecognized loss		100			129
Net periodic benefit cost	$	1,006		$	1,270