Fair Value of Financial Instruments (Tables)

6 Months Ended

Aug. 01, 2015

Fair Value Disclosures [Abstract]

Schedule of Assets Measured at Fair Value

Assets measured at fair value were as follows (in thousands):

	August 1, 2015						January 31, 2015
	Level 1		Level 2		Total		Level 1		Level 2		Total
Cash equivalents
Money market funds	$	2	$	—	$	2	$	44	$	—	$	44
Commercial paper		—		48,882		48,882		—		18,248		18,248
Government agency obligations		—		1,081		1,081		—		1,001		1,001
Total cash equivalents		2		49,963		49,965		44		19,249		19,293
Short-term investments
Commercial paper		—		20,532		20,532		—		13,996		13,996
Government agency obligations		—		129,160		129,160		—		48,172		48,172
Total short-term investments		—		149,692		149,692		—		62,168		62,168
Long-term investments
Government agency obligations		—		—		—		—		18,338		18,338
Total long-term investments		—		—		—		—		18,338		18,338
Total	$	2	$	199,655	$	199,657	$	44	$	99,755	$	99,799

Estimated Fair Value and Carrying Value of 2019 and 2020 Notes

The estimated fair value and carrying value of the 2019 Notes and 2020 Notes (carrying value excludes the equity component of the 2019 Notes and 2020 Notes classified in stockholders’ equity) were as follows (in thousands):

	August 1, 2015				January 31, 2015
	Fair Value		Carrying Value		Fair Value		Carrying Value
Convertible senior notes due 2019	$	272,460	$	294,024	$	260,444	$	287,487
Convertible senior notes due 2020	$	214,793	$	217,747	$	—	$	—