Retirement Plans (Details 3) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan, Fair Value Of Plan Assets	$ 9,754	$ 9,019	$ 9,217	$ 8,673
Debt Securities [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	3,188	2,916
Equity Securities [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	6,153	5,733
Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	413	370
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	6,566	6,103
Fair Value, Inputs, Level 1 [Member] | Debt Securities [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	6,153	5,733
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	413	370
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	3,188	2,916
Fair Value, Inputs, Level 2 [Member] | Debt Securities [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	3,188	2,916
Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 3 [Member] | Debt Securities [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	$ 0	$ 0