Pension and Other Postretirement Plans - Assumptions Used for Benefit Plans (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Pension Benefits
Assumptions used to determine benefit obligations
Discount rate	2.90%	2.72%
Rate of compensation increase	3.83%	3.88%
Assumptions used to determine net expense
Discount rate	2.72%	3.51%
Expected return on plan assets	7.28%	7.31%
Rate of compensation increase	3.88%	3.88%
Other Postretirement Benefits
Assumptions used to determine benefit obligations
Discount rate	2.82%	2.43%
Assumptions used to determine net expense
Discount rate	2.43%	3.35%
Expected return on plan assets	3.00%	3.00%
Health care cost trend rate assumed for next year	5.70%	5.80%
Rate to which the cost trend rate is assumed to decline (ultimate trend rate in 2033)	4.50%	4.50%