Foreign Currency Transaction Exposure - Summary (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Currency Transaction Gains (Losses) [Line Items]
Currency transaction gains (losses), net	$ 1,789	$ (11,828)	$ (3,649)	$ (3,508)
Operating income (loss)
Currency Transaction Gains (Losses) [Line Items]
Currency transaction gains (losses), net	672	(12,274)	(3,098)	(4,541)
Other non-operating income (expense), net
Currency Transaction Gains (Losses) [Line Items]
Currency transaction gains (losses), net	$ 1,117	$ 446	$ (551)	$ 1,033

Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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