Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 1,211,242	$ 558,929	$ 186,678
Other comprehensive income (loss):
Foreign currency translation adjustments	975	27,409	(5,464)
Change in unrealized gains (losses) on available-for-sale securities, net of tax of $0, $378, and $126, respectively	0	599	207
Total other comprehensive income (loss)	975	28,008	(5,257)
Comprehensive income	$ 1,212,217	$ 586,937	$ 181,421

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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