Employee Benefit Plans - Assumptions Used to Determine Projected Postretirement Benefit Obligations and Postretirement Costs (Details)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Weighted-average assumptions used to determine projected pension benefit obligations
Discount rate	2.85%	2.65%	3.50%
Health care cost trend rate for medical benefits assumed for next year (pre-65)	6.50%	6.75%	7.00%
Health care cost trend rate for medical benefits assumed for next year (post-65)	4.75%	5.00%	5.25%
Ultimate trend rate (pre-65)	4.50%	4.50%	4.50%
Ultimate trend rate (post-65)	4.50%	4.50%	4.50%
Beginning discount rate	2.65%	3.50%	4.45%