Investments

9 Months Ended

Sep. 30, 2011

Investments [Abstract]

Investments

Note 4. Investments

We have cash investment policies that limit investments to investment grade securities. At September 30, 2011 and December 31, 2010, all of our investments were classified as available-for-sale and carried at fair value. Our investments in corporate debt are guaranteed by the FDIC or foreign governments. At September 30, 2011, all of our investments had maturity dates of less than twenty-four months.

The amortized cost and fair value of our investments, with gross unrealized gains and losses, were as follows:

At September 30, 2011

			Gross		Gross
	Amortized		Unrealized		Unrealized			Aggregate
	Cost Basis		Gains		Losses			Fair Value
Short-term investments:
U.S. government agency debt	$	25,185,201	$	3,384	$	(5,924	)	$	25,182,661
Corporate debt		15,094,437		14,770		—			15,109,207
Certificates of deposit		50,000,000		—		—			50,000,000
Total short-term investments	$	90,279,638	$	18,154	$	(5,924	)	$	90,291,868

At December 31, 2010

			Gross		Gross
	Amortized		Unrealized		Unrealized			Aggregate
	Cost Basis		Gains		Losses			Fair Value
Short-term investments:
Corporate debt	$	21,294,673	$	35,437	$	—		$	21,330,110
Total short-term investments	$	21,294,673	$	35,437	$	—		$	21,330,110
Long-term investments:
U.S. government agency debt	$	4,006,714	$	—	$	(1,055	)	$	4,005,659
Total long-term investments	$	4,006,714	$	—	$	(1,055	)	$	4,005,659

For the three and nine months ended September 30, 2011 and 2010 we did not have any realized gains or losses on our investments.