Pension and Other Post Retirement Benefit Plans - Schedule of Plan Assets by Category (Details)	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Actual (as a percent)	100.00%	100.00%
Target (as a percent)	100.00%	100.00%
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Actual (as a percent)	2.70%	3.00%
Target (as a percent)	3.00%	3.00%
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Actual (as a percent)	53.00%	52.30%
Target (as a percent)	50.00%	50.00%
Debt securities
Defined Benefit Plan Disclosure [Line Items]
Actual (as a percent)	42.30%	42.30%
Target (as a percent)	45.00%	45.00%
Alternative investments
Defined Benefit Plan Disclosure [Line Items]
Actual (as a percent)	2.00%	2.40%
Target (as a percent)	2.00%	2.00%