Condensed Consolidated Statements of Stockholders' Equity - Parenthetical (Unaudited) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Stockholders' Equity [Abstract]
Unrealized gain (loss) on marketable securities tax expense (benefit)		$ 0	$ 5	$ 13	$ 11	$ (18)	$ 6	$ 6
Gain (loss) on derivatives, tax (benefit) expense		0	(33)	(6)	4	28	(139)	26
Foreign currency translation tax expense (benefit)	$ (37)	$ (37)	$ (55)	$ 7	$ 3	$ (3)	$ (101)	$ 7

Amount of tax expense (benefit), after reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature, attributable to parent entity.

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Amount of tax expense (benefit), after reclassification adjustments, 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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Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.

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