Retirement Benefits (Tables)

6 Months Ended

Jun. 30, 2014

Compensation and Retirement Disclosure [Abstract]

Components of Net Periodic Benefit Cost

The components of the net periodic pension benefit costs were as follows:

	Three Months Ended						Six Months Ended
	June 30, 2014			June 30, 2013			June 30, 2014			June 30, 2013
	(Dollars in thousands)
Service cost	$	3,316		$	3,947		$	6,771		$	8,056
Interest cost	7,419			6,624			14,849			13,272
Expected return on plan assets	(14,333		)	(13,156		)	(28,688		)	(26,269		)
Amortization of prior service cost	334			421			619			849
Amortization of actuarial losses	217			2,898			434			5,885
Net periodic benefit (credit) cost	$	(3,047	)	$	734		$	(6,015	)	$	1,793

The components of the net periodic other postretirement benefits costs were as follows:

	Three Months Ended						Six Months Ended
	June 30, 2014			June 30, 2013			June 30, 2014			June 30, 2013
	(Dollars in thousands)
Service cost	$	126		$	191		$	264		$	392
Interest cost	417			443			825			917
Amortization of prior service credit	(714		)	(669		)	(1,428		)	(1,339		)
Amortization of actuarial (gains) losses	(86		)	49			(171		)	104
Net periodic benefit (credit) cost	$	(257	)	$	14		$	(510	)	$	74