Marketable Securities (Tables)

3 Months Ended

Jan. 31, 2013

Investments, Debt and Equity Securities [Abstract]

Short-term and long-term investments

As of the dates indicated, short-term investments are comprised of the following (in thousands):

	January 31, 2013
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
U.S. government obligations	$	84,918	$	—	$	—	$	84,918
Included in short-term investments	$	84,918	$	—	$	—	$	84,918

	October 31, 2012
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
U.S. government obligations	$	49,987	$	70	$	—	$	50,057
Included in short-term investments	$	49,987	$	70	$	—	$	50,057

Legal maturities of debt investments

The following table summarizes final legal maturities of debt investments at January 31, 2013 (in thousands):

	Amortized Cost		Estimated Fair Value
Less than one year	$	84,918	$	84,918
Due in 1-2 years	—		—
	$	84,918	$	84,918