Employee Benefits - Schedule of Significant Assumptions of Pension and Other Postretirement Benefit Plans (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Plan Asset
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.74%	3.44%	4.38%
Rate of compensation increase	3.51%	2.97%	3.00%
Discount rate	3.44%	4.38%	3.75%
Expected return on plan assets	6.50%	6.20%	5.95%
Rate of compensation increase	2.97%	3.00%	3.02%
Other Postretirement Benefit Cost
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.56%	3.36%	4.32%
Discount rate	3.36%	4.32%	4.23%
Expected return on plan assets	3.68%	3.56%	4.77%
Other Postretirement Benefit Cost | Maximum
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate, benefit obligations, percentage	6.25%	6.50%	6.75%
Health care cost trend rate, net periodic costs, percentage	6.50%	6.75%	7.00%
Other Postretirement Benefit Cost | Minimum
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate, benefit obligations, percentage	5.00%	5.00%	5.00%
Health care cost trend rate, benefit obligation, year	2026	2026	2026
Health care cost trend rate, net periodic costs, percentage	5.00%	5.00%	4.50%
Health care cost trend rate, net periodic costs, year	2026	2026	2026