Post Employment Plans - Weighted Average Assumptions (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	2.04%	1.91%	1.76%
Inflation	1.45%	1.45%	1.43%
Expected return on assets	2.94%	2.90%	2.89%
Other Postretirement Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	3.59%	3.59%	4.00%