Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (644,239)	$ (178,903)	$ (1,782,712)	$ (413,242)
Other comprehensive income
Foreign currency translation adjustment	420	191	667	240
Unrealized gain on marketable securities, net of taxes	2,887	1,621	4,693	559
Other comprehensive income	3,307	1,812	5,360	799
Comprehensive loss	$ (640,932)	$ (177,091)	$ (1,777,352)	$ (412,443)

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax and 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.

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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