Retirement Plans (Income (Loss) Estimated to be Amortized from Accumulated Other Comprehensive Income (Loss) into Net Periodic Cost) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($)
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	$ (76)
Amortization of net gain (loss), next twelve months	(1,423)
Total amortization of accumulated other comprehensive income (loss), next twelve months	(1,499)
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	0
Amortization of net gain (loss), next twelve months	(1,468)
Total amortization of accumulated other comprehensive income (loss), next twelve months	(1,468)
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	(76)
Amortization of net gain (loss), next twelve months	65
Total amortization of accumulated other comprehensive income (loss), next twelve months	(11)
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	(20)
Total amortization of accumulated other comprehensive income (loss), next twelve months	$ (20)