Employee Benefit Plans (Details 6) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan, Fair Value Of Plan Assets	$ 61,384	$ 53,895	$ 45,427
Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	238	219
United States Large Cap Growth [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	5,193	4,497
United States Large Cap Value [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	5,317	4,586
United States Small and Mid Cap Growth [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	2,159	1,856
United States Small and Mid Cap Value [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	2,167	1,888
Non United States Core [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	9,478	8,470
United States Large Cap Passive [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	6,004	5,387
Emerging Markets [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	732	0
United States Core Opportunistic [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	22,189	19,410
United States Passive [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	7,907	7,582
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	238	219
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	238	219
Fair Value, Inputs, Level 1 [Member] | United States Large Cap Growth [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | United States Large Cap Value [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | United States Small and Mid Cap Growth [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | United States Small and Mid Cap Value [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | Non United States Core [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | United States Large Cap Passive [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | Emerging Markets [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | United States Core Opportunistic [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | United States Passive [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	0	0
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	61,146	53,676
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 2 [Member] | United States Large Cap Growth [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	5,193	4,497
Fair Value, Inputs, Level 2 [Member] | United States Large Cap Value [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	5,317	4,586
Fair Value, Inputs, Level 2 [Member] | United States Small and Mid Cap Growth [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	2,159	1,856
Fair Value, Inputs, Level 2 [Member] | United States Small and Mid Cap Value [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	2,167	1,888
Fair Value, Inputs, Level 2 [Member] | Non United States Core [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	9,478	8,470
Fair Value, Inputs, Level 2 [Member] | United States Large Cap Passive [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	6,004	5,387
Fair Value, Inputs, Level 2 [Member] | Emerging Markets [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	732	0
Fair Value, Inputs, Level 2 [Member] | United States Core Opportunistic [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	22,189	19,410
Fair Value, Inputs, Level 2 [Member] | United States Passive [Member]
Defined Benefit Plan, Fair Value Of Plan Assets	$ 7,907	$ 7,582