Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Mar. 31, 2013	Dec. 31, 2012
Amounts Recognized in Other Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, before Tax	$ 3		$ 21
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Tax	(2)		(9)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(40)		(40)		(41)	(41)
Accumulated Other Comprehensive Loss	(1,207)		(1,207)		(1,305)	(1,328)
Other Comprehensive Income Loss Derivatives Before Reclassification Adjustments Net Of Tax	0		0
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	1		1
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Net of Tax	1		12
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, before Tax	120		112
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax	(28)		(45)
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	122		122		117	69
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	(1,289)		(1,289)		(1,381)	(1,356)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Reclassification Adjustments, Net of Tax	4		41
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments, Net of Tax	0		0
Total Other Comprehensive Income Before Reclassification, Net of Tax	4		41
Other Comprehensive Income Loss Reclassification Adjustment Derivatives Included In Net Income Net Of Tax	1		1
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, Net of Tax	92		67
Total Amounts Reclassified From AOCI, Net of Tax	94		80
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	5		53
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	92		67
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ 98	$ (58)	$ 121	$ (3)