Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss):	$ (15,251)	$ 67,362	$ 636,667	$ 185,803
Unrealized net gain (loss) on available-for-sale securities, net of tax	(187)	87	546	73
Foreign currency translation	(764)	0	(1,015)	0
Comprehensive income (loss)	$ (16,202)	$ 67,449	$ 636,198	$ 185,876