Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2013

Defined Benefit Pension Plans [Member]

Defined Benefit Plan Disclosure [Line Items]

Components Of Net Periodic Benefit Expense (Income)

	Qualified Pension Plans
	Three Months Ended June 30,						Six Months Ended June 30,
(Dollars in thousands)	2013			2012			2013			2012
Interest cost on benefit obligation	$	17,422		$	17,582		$	35,011		$	35,084
Expected return on plan assets	(23,005		)	(21,095		)	(45,662		)	(42,206		)
Amortization of actuarial loss	4,486			4,889			9,136			9,716
Amortization of prior-service costs	417			4			835			7
Net periodic benefit expense (income)	$	(680	)	$	1,380		$	(680	)	$	2,601
	Non-Qualified Pension Plans
	Three Months Ended June 30,						Six Months Ended June 30,
(Dollars in thousands)	2013			2012			2013			2012
Interest cost on benefit obligation	$	803		$	863		$	1,607		$	1,719
Amortization of actuarial loss	280			242			559			523
Amortization of prior-service costs	2			—			3			—
Net periodic benefit expense	$	1,085		$	1,105		$	2,169		$	2,242

Postretirement Medical Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Components Of Net Periodic Benefit Expense (Income)

	Three Months Ended June 30,						Six Months Ended June 30,
(Dollars in thousands)	2013			2012			2013			2012
Service cost	$	313		$	417		$	742		$	840
Interest cost on benefit obligation	848			1,138			1,739			2,159
Amortization of prior-service credit	(263		)	(301		)	(526		)	(603		)
Net periodic benefit expense	$	898		$	1,254		$	1,955		$	2,396