Pension and Other Post Retirement Benefit Plans Pension and Other Post Retirement Benefit Plans - Schedule of Plan Assets by Level (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 62,865	$ 62,078	$ 63,275
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	45,296
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	17,569
Cash and cash equivalents | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	795
Cash and cash equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	795
Corporate Bonds and Notes | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	6,157
Corporate Bonds and Notes | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	6,157
Government Agency and Municipal Bonds and Notes | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8,642
Government Agency and Municipal Bonds and Notes | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8,642
Certificates of Deposit | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	357
Certificates of Deposit | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	357
Preferred | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	52
Preferred | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	52
Common Stock | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	898
Common Stock | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	898
Common Bond Fund | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,075
Common Bond Fund | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,075
Common Equity Fund | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,495
Common Equity Fund | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,495
Taxable Bond | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	7,409
Taxable Bond | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	7,409
Large Cap Equity | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	16,166
Large Cap Equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	16,166
Mid Cap Equity | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	6,772
Mid Cap Equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	6,772
Small Cap Equity | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,640
Small Cap Equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,640
International Equity | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3,178
International Equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3,178
Specialty Alternative Equity | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,229
Specialty Alternative Equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 1,229