Income Taxes - Schedule of Significant Components of Deferred Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets
Intangible assets	$ 197	$ 842
Property, plant and equipment	8,363	8,963
Financial assets	7,004	7,044
Inventories	2,817	4,131
Receivables, other assets	3,212	1,207
Liabilities
Provisions	20,662	18,825
Liabilities	41,434	31,093
Other
Loss carryforwards	39,595	43,753
Interest carryforwards	9,967	9,041
Tax credits	3,185	1,022
Other	2,028	2,750
Total deferred tax assets (gross)	138,463	128,671
Valuation allowance	(41,994)	(40,905)
Total deferred tax assets (net)	96,468	87,766
Assets
Intangible assets	3,673	12,973
Property, plant and equipment	33,040	30,628
Financial assets	7,649	6,719
Receivables, other assets	11,883	12,157
Liabilities
Provisions	8,203	6,441
Liabilities	12,568	3,953
Other	14,039	8,005
Total deferred tax liabilities	91,057	80,876
Deferred income tax liabilities	43,308	45,504
Deferred income tax assets	48,720	52,395
Net deferred tax asset / (liability) positions	$ 5,412	$ 6,891