Investments

9 Months Ended

Sep. 30, 2011

Investments [Abstract]

Investments

7. Investments

Our available-for-sale investments were classified as short-term investments on our September 30, 2011, December 31, 2010 and September 30, 2010 Condensed Consolidated Balance Sheets. The following table sets forth the aggregate fair value, amortized cost basis and the net unrealized gains and losses included in accumulated other comprehensive income (loss) of our available-for-sale investments as of the dates indicated:

	As of:
	September 30, 2011						December 31, 2010						September 30, 2010
	Aggregate     Fair Value		Amortized     Cost		Net     Unrealized     Gains (Losses)		Aggregate   Fair Value		Amortized   Cost		Net   Unrealized   Gains (Losses)		Aggregate   Fair Value		Amortized   Cost		Net   Unrealized   Gains (Losses)
Available-for-Sale Investments:
Government obligations		$90,629		$90,611		$18		$110,560		$110,550		$10		$90,374		$90,348		$26
Government agency obligations		31,565		31,565		0		24,394		24,399		(5)		36,165		36,153		12
Corporate obligations		24,605		24,645		(40)		8,903		8,908		(5)		10,683		10,688		(5)
		$146,799		$146,821		($22)		$143,857		$143,857		$0		$ 137,222		$ 137,189		$ 33

We also held a certificate of deposit with a total principal value of $5,303 as of December 31, 2010 and $5,261 as of September 30, 2010. We did not hold a certificate of deposit as of September 30, 2011. This investment was included in Short-term investments on our Condensed Consolidated Balance Sheets as of the applicable dates. We had $146,799 of debt securities classified as available-for-sale as of September 30, 2011, and all of those debt securities had contractual maturities within one year.

The following table sets forth the unrealized gains and losses on available-for-sale investments that were included in other comprehensive income (loss) in the periods indicated:

	Three Months Ended          September 30,				Nine Months Ended          September 30,
	2011		2010		2011		2010
Unrealized gains		$0		$0		$0		$56
Unrealized losses		($15)		($14)		($102)		$0

The following table sets forth the components of investment income included in Interest income in our Condensed Consolidated Statements of Income in the periods indicated:

		0000		0000		0000		0000	0000	0000
	Three Months  Ended September 30,				Nine Months  Ended September 30,
	2011		2010		2011		2010
Interest income on investments		$91		$188		$362		$551
Realized net gains on the sale of investments		23		51		219		150
		$114		$239		$581		$701