Retirement Plans (Schedule Of Funded Status Plan And Change In Funded Status Plan) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Change in fair value of plan assets: At beginning of year	$ 26,858
Change in fair value of plan assets: At end of year	28,471
Discount rate - Benefit obligations	4.41%	5.09%
Expected return on plan assets	8.00%
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
At beginning of year	36,690	34,760
Service cost	774	731	790
Interest cost	1,819	1,883	1,847
Plan participants' contributions	238	231
Actuarial (gain) loss	6,122	965
Benefits paid	(1,397)	(1,880)
At end of year	44,246	36,690	34,760
Change in fair value of plan assets: At beginning of year	26,858	24,587
Actual return on plan assets	724	2,802
Employer contribution	2,048	1,118
Change in fair value of plan assets: At end of year	28,471	26,858	24,587
Funded status - net pension liability at year end	(15,775)	(9,832)
Amounts recognized in accumulated other comprehensive loss, Net actuarial loss	19,744	13,665
Net actuarial loss	1,885	1,370
Discount rate - Components of cost	5.09%	5.52%
Discount rate - Benefit obligations	4.41%	5.09%
Expected return on plan assets	8.00%	8.00%
Supplemental Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
At beginning of year	3,204	5,720
Service cost	20	16	93
Interest cost	159	192	318
Plan participants' contributions	11	6
Actuarial (gain) loss	464	493
Benefits paid	(158)	(3,223)
At end of year	3,700	3,204	5,720
Employer contribution	147	3,217
Funded status - net pension liability at year end	3,700	3,204
Amounts recognized in accumulated other comprehensive loss, Net actuarial loss	1,863	1,552
Net actuarial loss	192	153
Discount rate - Components of cost	5.09%	5.52%
Discount rate - Benefit obligations	4.41%	5.09%
Postretirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
At beginning of year	1,837	1,783
Service cost	38	38	49
Interest cost	81	89	92
Plan participants' contributions	55	59
Actuarial (gain) loss	(35)	(79)
Benefits paid	(69)	(53)
At end of year	1,907	1,837	1,783
Change in fair value of plan assets: At beginning of year
Employer contribution	14	(6)
Change in fair value of plan assets: At end of year
Funded status - net pension liability at year end	1,907	1,837
Amounts recognized in accumulated other comprehensive loss, Net actuarial loss	348	411
Net actuarial loss	$ 21	$ 25
Discount rate - Components of cost	4.56%	5.17%
Discount rate - Benefit obligations	3.91%	4.56%