Categories of Financial Assets and Financial Liabilities - Credit Risks (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Concentration Risk [Line Items]
Allowance for doubtful accounts receivable, period increase (decrease)	$ 5,400	$ 2,300
Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk, maximum exposure	756,872	677,884
Cash and cash equivalents | Carrying Value
Concentration Risk [Line Items]
Concentration risk, maximum exposure	270,317	353,537
Trade receivables, net of allowances | Carrying Value
Concentration Risk [Line Items]
Concentration risk, maximum exposure	397,244	261,581
Other taxes | Carrying Value
Concentration Risk [Line Items]
Concentration risk, maximum exposure	52,942	29,552
Other current assets | Carrying Value
Concentration Risk [Line Items]
Concentration risk, maximum exposure	19,340	16,030
Financial assets | Carrying Value
Concentration Risk [Line Items]
Concentration risk, maximum exposure	$ 17,029	$ 17,184