Investments in U.S. Treasury Securities

9 Months Ended

Jul. 31, 2011

Investments in U.S. Treasury Securities [Abstract]

Investments in U.S. Treasury Securities

Note 4. Investments in U.S. Treasury Securities

We classify our investments as held-to-maturity and record them at amortized cost. These investments consist entirely of U.S. treasury securities. The following table summarizes the amortized cost basis and fair value (based on quoted market prices) at July 31, 2011 and October 31, 2010:

			Gross		Gross
	Amortized		unrealized		unrealized
	cost		gains		(losses)		Fair value
U.S. government obligations
As of July 31, 2011	$	18,040	$	23	$	—	$	18,063
As of October 31, 2010	$	34,090	$	74	$	—	$	34,164

The following table summarizes the contractual maturities of investments at amortized cost and fair value as of July 31, 2011:

					Weighted
					average
	Amortized				yield to
	cost		Fair value		maturity
Due within one year	$	18,040	$	18,063		1.2	%
Due after one year		—		—		—
Total investments	$	18,040	$	18,063		1.2	%