Defined Benefit Pension Plans (Components of Net Periodic Benefit Cost) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Qualified Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 643	$ 578	$ 1,287	$ 1,157
Interest Cost	706	644	1,412	1,289
Expected Return on Plan Assets	(747)	(698)	(1,493)	(1,397)
Amortization of Prior Service Cost	(9)	(9)	(17)	(17)
Recognized Net Actuarial Loss	247	99	491	196
Net Periodic Benefit Cost	840	614	1,680	1,228
Non-Qualified Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	37	18	75	36
Interest Cost	126	124	252	248
Expected Return on Plan Assets	0	0	0	0
Amortization of Prior Service Cost	0	0	0	0
Recognized Net Actuarial Loss	30	3	59	6
Net Periodic Benefit Cost	$ 193	$ 145	$ 386	$ 290