Retirement Benefits

3 Months Ended

Mar. 31, 2016

Retirement Benefits [Abstract]

Retirement Benefits

15.  RETIREMENT BENEFITS

The Company maintains both qualified and non-qualified defined benefit pension plans and a retiree health plan for its U.S. employees employed prior to April 1, 2010.

Net periodic benefit cost for U.S. employees included the following components for the periods indicated:

Pension Benefits	Three Months Ended
	March 31,
(Dollars in thousands)	2016			2015
Service cost	$	2,897		$	2,940
Interest cost		2,361			2,457
Expected return on plan assets		(2,484	)		(2,903	)
Amortization of prior service cost		-			5
Amortization of net (income) loss		2,014			2,251
Net periodic benefit cost	$	4,788		$	4,750

Other Benefits	Three Months Ended
	March 31,
(Dollars in thousands)	2016		2015
Service cost	$	438	$	401
Interest cost		296		263
Amortization of net (income) loss		48		211
Net periodic benefit cost	$	782	$	875

The Company did not make any contributions to the qualified pension benefit plan for the three months ended March 31, 2016 and 2015.