Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 29, 2016	Oct. 31, 2015	Oct. 29, 2016	Oct. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 2,517	$ 20,710	$ (4,035)	$ 57,801
Net gains (losses) from foreign currency translation	(915)	(18)	485	(872)
Net unrealized holding gains (losses) on available-for-sale investments	(59)	(13)	84	(18)
Total comprehensive income (loss)	$ 1,543	$ 20,679	$ (3,466)	$ 56,911