Pensions and Other Benefits - Actuarial Assumptions (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation, Discount rate		2.58%	3.25%	4.01%
Benefit obligation, Projected future salary increases		2.75%	2.75%	2.75%
Health care cost trend rate		5.50%	6.00%	7.00%
Benefit cost, Discount rate		3.25%	4.01%	3.80%
Benefit cost, Expected rate of return on fund assets		7.25%	7.50%	7.75%
Benefit cost, Projected future salary increases		2.75%	2.75%	2.75%
Health care cost trend rate change		0.50%
Ultimate health care cost trend rate		5.00%
Forecast
Defined Benefit Plan Disclosure [Line Items]
Benefit cost, Expected rate of return on fund assets	6.90%