Pension and Other Post Retirement Benefit Plans - Schedule of Plan Assets by Level (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 76,736	$ 85,213	$ 83,557
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	71,277	78,280
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash & Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3,026	5,123
Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate Bonds and Notes
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	16,691	14,598
Quoted Prices in Active Markets for Identical Assets (Level 1) | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,073	2,545
Quoted Prices in Active Markets for Identical Assets (Level 1) | Taxable Bond
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	12,817	12,198
Quoted Prices in Active Markets for Identical Assets (Level 1) | Large Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	18,269	22,137
Quoted Prices in Active Markets for Identical Assets (Level 1) | Mid Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8,735	10,676
Quoted Prices in Active Markets for Identical Assets (Level 1) | Small Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,713	5,264
Quoted Prices in Active Markets for Identical Assets (Level 1) | International Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3,336	4,030
Quoted Prices in Active Markets for Identical Assets (Level 1) | Specialty Alternative Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,617	1,709
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5,459	6,933
Significant Other Observable Inputs (Level 2) | Government Agency and Municipal Bonds and Notes
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,479	5,679
Significant Other Observable Inputs (Level 2) | Certificates of Deposit
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	980	1,254
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets
Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	76,736	85,213
Fair Value | Cash & Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3,026	5,123
Fair Value | Corporate Bonds and Notes
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	16,691	14,598
Fair Value | Government Agency and Municipal Bonds and Notes
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,479	5,679
Fair Value | Certificates of Deposit
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	980	1,254
Fair Value | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,073	2,545
Fair Value | Taxable Bond
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	12,817	12,198
Fair Value | Large Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	18,269	22,137
Fair Value | Mid Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8,735	10,676
Fair Value | Small Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,713	5,264
Fair Value | International Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3,336	4,030
Fair Value | Specialty Alternative Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 1,617	$ 1,709