Post Employment Plans - Weighted Average Assumptions (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	0.95%	1.06%	2.04%
Decrease in the discount rate attributable to the reduction in bond yields across the Euro zone	0.11%
Inflation	1.33%	1.18%	1.45%
Expected return on assets	1.76%	2.54%	2.94%
Interest crediting rates	0.59%	0.83%	1.41%
Other Postretirement Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	3.14%	4.25%	3.59%