Retirement Plans (Income (Loss) Estimated to be Amortized from Accumulated Other Comprehensive Income (Loss) into Net Periodic Cost) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Amortization of prior service credits, next twelve months	$ 1
Amortization of net gain (loss), next twelve months	(2,454)
Total amortization of accumulated other comprehensive income (loss), next twelve months	(2,453)
Pension Plan [Member]
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Amortization of prior service credits, next twelve months	1
Amortization of net gain (loss), next twelve months	(2,385)
Total amortization of accumulated other comprehensive income (loss), next twelve months	(2,384)
Postretirement Plan [Member]
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Amortization of prior service credits, next twelve months	0
Amortization of net gain (loss), next twelve months	6
Total amortization of accumulated other comprehensive income (loss), next twelve months	6
Supplemental Plan [Member]
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Amortization of prior service credits, next twelve months	0
Amortization of net gain (loss), next twelve months	(75)
Total amortization of accumulated other comprehensive income (loss), next twelve months	$ (75)