Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 384,349	$ 65,600	$ 674,473	$ 243,822
Other comprehensive income:
Foreign currency translation adjustments	(16,691)	14,347	8,130	16,926
Change in unrealized gains on available-for-sale securities, net of tax of $0, $89, $0, and $166, respectively	0	144	0	271
Total other comprehensive income (loss)	(16,691)	14,491	8,130	17,197
Comprehensive income	$ 367,658	$ 80,091	$ 682,603	$ 261,019