Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2015

Pension Costs [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Benefit Plans

	For the Three Months Ended
	March 31,
	2014			2015
	(Dollars in thousands)
Service cost	$	473		$	827
Interest cost	2,169			1,526
Expected return on plan assets	(1,938		)	(1,354		)
Amortization of prior service cost	1			1
Net cost	$	705		$	1,000

Postretirement Costs [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Benefit Plans

	For the Three Months Ended
	March 31,
	2014			2015
	(Dollars in thousands)
Service cost	$	19		$	4
Interest cost	352			315
Amortization of prior service benefit	(47		)	(43		)
Net cost	$	324		$	276