Fair Value Measurements (Tables)

3 Months Ended

Apr. 30, 2014

Fair Value Disclosures [Abstract]

Fair Value Hierarchy for Financial Assets Measured at Fair Value on Recurring Basis

The following table presents the fair value hierarchy for financial assets measured at fair value on a recurring basis as of April 30, 2014 (in thousands):

	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	56,401	$	—	$	—	$	56,401
Commercial paper		—		6,300		—		6,300
Corporate notes and bonds		—		3,502		—		3,502
U.S. agency obligations		—		13,871		—		13,871
U.S. treasury securities		—		2,000		—		2,000
Short-term investments
Asset backed-securities		—		3,703		—		3,703
Commercial paper		—		4,997		—		4,997
Corporate notes and bonds		—		23,870		—		23,870
U.S. agency obligations		—		102,616		—		102,616
U.S. treasury securities		—		21,422		—		21,422
Total	$	56,401	$	182,281	$	—	$	238,682

The following table presents the fair value hierarchy for financial assets measured at fair value on a recurring basis as of January 31, 2014 (in thousands):

	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	170,235	$	—	$	—	$	170,235
Commercial paper		—		9,999		—		9,999
U.S. treasury securities		—		33,153		—		33,153
Short-term investments
Corporate notes and bonds		—		10,507		—		10,507
U.S. agency obligations		—		15,118		—		15,118
Total	$	170,235	$	68,777	$	—	$	239,012