Investments in U.S. Treasury Securities

9 Months Ended

Jul. 31, 2012

Schedule of Investments [Abstract]

Investments in U.S. Treasury Securities

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, 2012 and October 31, 2011:

	Amortized cost		Gross unrealized gains		Gross unrealized (losses)		Fair value
U.S. government obligations
As of July 31, 2012	$	—	$	—	$	—	$	—
As of October 31, 2011	$	12,016	$	14	$	—	$	12,030