Pension and Other Post Retirement Benefit Plans - Schedule of Plan Assets by Level (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 88,512	$ 85,121	$ 76,736
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	85,007	80,689
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash & Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,361	2,578
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	16,330	17,629
Quoted Prices in Active Markets for Identical Assets (Level 1) | Government Agency and Municipal Bonds and Notes
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Certificates of Deposit
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,263	2,516
Quoted Prices in Active Markets for Identical Assets (Level 1) | Taxable Bond
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	17,676	13,938
Quoted Prices in Active Markets for Identical Assets (Level 1) | Large Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	25,117	21,958
Quoted Prices in Active Markets for Identical Assets (Level 1) | Mid Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	10,731	10,407
Quoted Prices in Active Markets for Identical Assets (Level 1) | Small Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,867	5,753
Quoted Prices in Active Markets for Identical Assets (Level 1) | International Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3,912	3,898
Quoted Prices in Active Markets for Identical Assets (Level 1) | Specialty Alternative Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,750	2,012
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3,505	4,432
Significant Other Observable Inputs (Level 2) | Cash & Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Other Observable Inputs (Level 2) | Corporate Bonds and Notes
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Other Observable Inputs (Level 2) | Government Agency and Municipal Bonds and Notes
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,462	3,660
Significant Other Observable Inputs (Level 2) | Certificates of Deposit
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,043	772
Significant Other Observable Inputs (Level 2) | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Other Observable Inputs (Level 2) | Taxable Bond
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Other Observable Inputs (Level 2) | Large Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Other Observable Inputs (Level 2) | Mid Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Other Observable Inputs (Level 2) | Small Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Other Observable Inputs (Level 2) | International Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Other Observable Inputs (Level 2) | Specialty Alternative Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) | Cash & Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) | Corporate Bonds and Notes
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) | Government Agency and Municipal Bonds and Notes
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) | Certificates of Deposit
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) | Taxable Bond
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) | Large Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) | Mid Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) | Small Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) | International Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) | Specialty Alternative Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	88,512	85,121
Fair Value | Cash & Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,361	2,578
Fair Value | Corporate Bonds and Notes
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	16,330	17,629
Fair Value | Government Agency and Municipal Bonds and Notes
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,462	3,660
Fair Value | Certificates of Deposit
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,043	772
Fair Value | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,263	2,516
Fair Value | Taxable Bond
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	17,676	13,938
Fair Value | Large Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	25,117	21,958
Fair Value | Mid Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	10,731	10,407
Fair Value | Small Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,867	5,753
Fair Value | International Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3,912	3,898
Fair Value | Specialty Alternative Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 1,750	$ 2,012