Short-term investments

9 Months Ended

Sep. 30, 2013

Short-term investments

Short-term investments

3. Short-term investments

We invest in short-term investments in order to maximize our return on cash. Short-term investments consist of VRDN, which are classified as available –for-sale securities and reported at fair value. VRDNs are municipal and corporate securities with an interest rate that is reset frequently.  While the contractual maturities of these instruments range between seven to twenty-two years, VRDNs are considered to be liquid instruments. All of the VRDNs currently in our portfolio are backed by a letter of credit from a reputed bank that may be tendered at any time with a typical settlement date of one week and the lack of volatility in the market has further helped to maintain the liquidity of the instrument. VRDNs are always purchased and redeemed at par value.  Any unrealized gains or losses on available-for-sale securities would be recorded in other comprehensive income. As of September 30, 2013, there were no unrealized gains or losses with respect to available-for-sale securities.

The following table presents the amortized cost and fair value of our available-for sale investments, which are carried at fair value:

	September 30, 2013
	Amortized Cost		Fair Value
Variable —rate demand notes	$	21,460	$	21,460