Financial Instruments and Fair Value Measurement - Narrative (Details) - Fair Value, Inputs, Level 2 - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivables from hedges/ derivatives	$ 8,436	$ 9,949
Prepaid expenses and other current assets	8,434	9,777
Other financial assets (non-current)	1	172
Liabilities from derivatives	9,425	7,032
Other current liabilities	109	2,302
Other liabilities (non-current)	9,316	4,730
Term loan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of loans	643,051	658,163
Local bank loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of loans	$ 29,762	$ 28,618

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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