Short-Term Investments (Tables)

6 Months Ended

Mar. 31, 2012

Cash, Cash Equivalents, and Short-term Investments [Abstract]

Schedule of cash, cash equivalents and short-term investments

Cash, cash equivalents and short-term investments consist of the following (in thousands):

	March 31, 2012
	Cost Basis		Unrealized Gains		Unrealized Losses			Fair Value
Cash and cash equivalents	$	86,030	$	34	$	—		$	86,064
Short-term investments:
Available-for-sale securities:
Certificates of deposit	$	2,000	$	3	$	—		$	2,003
U.S. Treasury and agency obligations	85,220		454		(19		)	85,655
Corporate notes and obligations	41,209		262		(18		)	41,453
Total short-term investments	$	128,429	$	719	$	(37	)	$	129,111

	October 1, 2011
	Cost Basis		Unrealized Gains		Unrealized Losses			Fair Value
Cash and cash equivalents	$	166,931	$	131	$	(1	)	$	167,061
Short-term investments:
Available-for-sale securities:
Certificates of deposit	$	6,500	$	10	$	—		$	6,510
International government obligations	1,101		1		(1		)	1,101
Corporate notes and obligations	45,282		275		(26		)	45,531
Total short-term investments	$	52,883	$	286	$	(27	)	$	53,142

Schedule of amortized cost and estimated fair value of available-for-sale investments in debt securities

The amortized cost and estimated fair value of available-for-sale investments in debt securities as of March 31, 2012 and October 1, 2011 classified as short-term investments on our condensed consolidated balance sheet were as follows (in thousands):

	March 31, 2012				October 1, 2011
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Due in less than 1 year	$	126,429	$	127,108	$	46,383	$	46,632
Total investments in available-for-sale debt securities	$	126,429	$	127,108	$	46,383	$	46,632