Pension and Post-Retirement Benefits - Investment Categories and Their Relative Percentage of Fair Value to Total Plan Assets (Details)	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits | Equity securities
Pension Plans, Postretirement and Other Employee Benefits
Percentage of the fair value of the total plan assets	52.10%	42.10%
Pension Benefits | Debt securities
Pension Plans, Postretirement and Other Employee Benefits
Percentage of the fair value of the total plan assets	46.60%	55.50%
Pension Benefits | Cash
Pension Plans, Postretirement and Other Employee Benefits
Percentage of the fair value of the total plan assets	1.30%	2.40%
Post-retirement Benefits | Equity securities
Pension Plans, Postretirement and Other Employee Benefits
Percentage of the fair value of the total plan assets	0.00%	0.00%
Post-retirement Benefits | Debt securities
Pension Plans, Postretirement and Other Employee Benefits
Percentage of the fair value of the total plan assets	0.00%	0.00%
Post-retirement Benefits | Cash
Pension Plans, Postretirement and Other Employee Benefits
Percentage of the fair value of the total plan assets	0.00%	0.00%