Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

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Accumulated adjustment, net of tax, that results from the process of translating subsidiary financial statements and foreign equity investments into the reporting currency from the functional currency of the reporting entity, net of reclassification of realized foreign currency translation gains or losses.

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Derivative Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Foreign Currency Derivatives [Abstract]
Unrealized gains/(losses) related to foreign currency cash flow hedges included in accumulated other comprehensive loss	$ 0		$ 0		$ 0
Cumulative translation adjustments included in accumulated other comprehensive loss	81,300		81,300		$ 79,900
Foreign Currency Forward Contracts [Member] \| Not Designated as Hedging Instrument [Member]
Foreign Currency Derivatives [Abstract]
Gain (loss) on derivative instruments	0	$ 0	0	$ 0
Foreign Currency Forward Contracts [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedges [Member]
Foreign Currency Derivatives [Abstract]
Notional amount	0	0	0	0
Foreign Currency Forward Contracts [Member] \| Other Comprehensive Income (Loss) [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedges [Member]
Foreign Currency Derivatives [Abstract]
Gain (loss) recognized in other comprehensive loss	0	87	0	(160)
Foreign Currency Forward Contracts [Member] \| Revenue [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedges [Member]
Foreign Currency Derivatives [Abstract]
Gain (loss) reclassified from accumulated other comprehensive loss into income	$ 0	$ (26)	$ 0	$ 18