Financial Liabilities - Maturity of Financial Liabilities and Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Borrowings
Borrowings	$ 82,921	$ 9,245	$ 13,051
Next fiscal year	5,522
Year two	817
Year three	632
Year four	75,634
Year five	316
Year six	0
Financial liabilities relating to finance leases
Financial liabilities relating to finance leases	0	23	307
Next fiscal year	0
Year two	0
Year three	0
Year four	0
Year five	0
Year six	0
Other financial liabilities
Other financial liabilities	691	608	679
Next fiscal year	477
Year two	0
Year three	214
Year four	0
Year five	0
Year six	0
Bank overdraft
Bank overdrafts	0
Next fiscal year	0
Year two	0
Year three	0
Year four	0
Year five	0
Year six	0
Financial derivatives
Financial liabilities	1,968	552	743
Next fiscal year	1,968
Year two	0
Year three	0
Year four	0
Year five	0
Year six	0
Financial liabilities
Financial liabilities	85,580	$ 10,428	$ 14,780
Next fiscal year	7,967
Year two	817
Year three	846
Year four	75,634
Year five	316
Year six	$ 0