5.	Cash Equivalents and Marketable Securities

Cash equivalents are short-term, highly liquid investments with original maturity dates of three months or less at the date of acquisition. Cash equivalents are carried at cost plus accrued interest, which approximates fair market value. As of January 28, 2012, the Company’s short and long term investments, as classified on the balance sheet, were $311.5 million and $73.7 million, respectively. These investments are marketable securities classified as available-for-sale and are recorded at fair value with any unrealized gain or loss recorded as an element of stockholders’ equity. The fair value of short and long term investments is determined based on quoted market prices at the reporting date for those instruments. As of January 28, 2012 and July 31, 2011, aggregate cash and cash equivalents and short and long term investments consisted of (in thousands):


January 28, 2012:	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Cash and cash equivalents	$	53,347	$	—	$	—		$	53,347
Corporate securities		11,971		—		(1	)		11,970
Government securities		373,047		197		(48	)		373,196

Total	$	438,365	$	197	$	(49	)	$	438,513


July 31, 2011:	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Cash and cash equivalents	$	60,765	$	—	$	—		$	60,765
Corporate securities		26,819		37		—			26,856
Government securities		353,907		27		(157	)		353,777

Total	$	441,491	$	64	$	(157	)	$	441,398