Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (12,217)	$ 2,215	$ (27,072)	$ 5,248
Other comprehensive income (loss), net of tax:
Change in foreign currency translation	(104)	40	(392)	(220)
Change in fair value of available for sale securities	154	103	1,440	(1,139)
Total other comprehensive income (loss)	50	143	1,048	(1,359)
Comprehensive income (loss)	$ (12,167)	$ 2,358	$ (26,024)	$ 3,889

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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