Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2012

Pension Costs [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Benefit Plans

	For the Three Months Ended						For the Six Months Ended
	June 30,						June 30,
	2011			2012			2011			2012
	(Dollars in thousands)						(Dollars in thousands)
Service cost	$	164		$	426		$	328		$	852
Interest cost	2,446			2,150			4,892			4,300
Expected return on plan assets	(2,138		)	(2,195		)	(4,276		)	(4,390		)
Amortization of prior service cost	13			6			26			12
Net cost	$	485		$	387		$	970		$	774

Postretirement Costs [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Benefit Plans

	For the Three Months Ended						For the Six Months Ended
	June 30,						June 30,
	2011			2012			2011			2012
	(Dollars in thousands)						(Dollars in thousands)
Service cost	$	41		$	46		$	82		$	92
Interest cost	440			381			880			762
Amortization of prior service benefit	(48		)	(49		)	(96		)	(98		)
Plan amendment	—			1,147			—			1,147
Net cost	$	433		$	1,525		$	866		$	1,903