Pension Benefit and Other Postretirement Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2014

Compensation and Retirement Disclosure [Abstract]

Components of net periodic benefit cost

The components of net periodic benefit cost (income) for the periods indicated are:

(Dollars in thousands)	Pension Benefits												Retirement Health and Life Insurance Benefits
	Three Months Ended						Nine Months Ended						Three Months Ended				Nine Months Ended
Change in benefit obligation:	September 30, 2014			September 30, 2013			September 30, 2014			September 30, 2013			September 30, 2014		September 30, 2013		September 30, 2014		September 30, 2013
Service cost	$	—		$	132		$	—		$	2,342		$	160	$	143	$	479	$	484
Interest cost	2,004			1,869			6,012			5,884			83		61		250		202
Expected return on plan assets	(3,227		)	(2,900		)	(9,682		)	(8,347		)	—		—		—		—
Amortization of prior service cost	—			—			—			124			—		—		—		(115		)
Amortization of net loss	172			545			515			3,070			31		—		92		165
Special termination benefit	—			—			—			—			—		—		—		—
Settlement charge	—			—			77			—			—		—		—		—
Curtailment charge	—			—			—			1,537			—		—		—		—
Net periodic benefit cost (income)	$	(1,051	)	$	(354	)	$	(3,078	)	$	4,610		$	274	$	204	$	821	$	736