Short-term and Long-term Investments (Tables)

3 Months Ended

Jan. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Short-term and long-term investments

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

	January 31, 2015
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
U.S. government obligations:
Included in short-term investments	$	115,129	$	39	—		$	115,168
Included in long-term investments	55,085		68		—		55,153
	$	170,214	$	107	$	—	$	170,321
Commercial paper:
Included in short-term investments	29,986		—		—		29,986
	$	29,986	$	—	$	—	$	29,986

	October 31, 2014
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
U.S. government obligations:
Included in short-term investments	$	110,182	$	29	$	—	$	110,211
Included in long-term investments	50,016		41		—		50,057
	$	160,198	$	70	$	—	$	160,268
Commercial paper:
Included in short-term investments	29,994		—		—		29,994
	$	29,994	$	—	$	—	$	29,994

Legal maturities of debt investments

The following table summarizes final legal maturities of debt investments at January 31, 2015 (in thousands):

	Amortized Cost		Estimated Fair Value
Less than one year	$	145,115	$	145,154
Due in 1-2 years	55,085		55,153
	$	200,200	$	200,307