Cash, Cash Equivalents, and Available-For-Sale Investments

6 Months Ended

Jun. 30, 2011

Cash, Cash Equivalents, and Available-For-Sale Investments [Abstract]

Cash, Cash Equivalents, and Available-For-Sale Investments

Note 2 — Cash, Cash Equivalents, and Available-For-Sale Investments

     Cash, cash equivalents, and available-for-sale investments are as follows (in thousands):

	Estimated Fair Value at
	June 30,		December 31,
	2011		2010
Cash and cash equivalents	$	11,626	$	17,755
Short-term investments		351,280		298,177
Long-term investments		118,941		—
Total cash, cash equivalents, and available-for-sale investments	$	481,847	$	315,932

     Our portfolio of cash, cash equivalents, and available-for-sale investments includes (in thousands):

	Estimated Fair Value at
	June 30,		December 31,
	2011		2010
Corporate notes and bonds	$	360,536	$	190,527
U.S. corporate commercial paper		101,434		82,361
Obligations of U.S. government agencies		8,251		25,289
Cash and money market funds		11,626		17,755
Total cash, cash equivalents, and available-for-sale investments	$	481,847	$	315,932

     The following table summarizes our portfolio of available-for-sale investments reported as short-term and long-term investments by contractual maturity (in thousands):

	Estimated Fair Value at
	June 30,		December 31,
	2011		2010
Less than one year	$	351,280	$	298,177
Greater than one year but less than two years		118,941		—
Total available-for-sale investments	$	470,221	$	298,177

     We invest in liquid, high quality debt securities. Our investments in debt securities are subject to interest rate risk. To minimize the exposure due to an adverse shift in interest rates, we invest in securities with maturities of two years or less and maintain a weighted average maturity of one year or less. Investments in securities with maturities of less than one year are classified as short-term investments.

     During the six months ended June 30, 2011 and 2010, we realized gains and losses of less than $0.1 million from sales of available-for-sale securities in each of the periods. The cost of securities sold is based on the specific identification method.

     Gross unrealized gains and losses were not significant at June 30, 2011 and December 31, 2010. The gross unrealized losses were primarily due to changes in interest rates on fixed income securities. Based on our available cash and our expected operating cash requirements, we do not intend to sell these securities and it is more likely than not that we will not be required to sell these securities before we recover the amortized cost basis. Accordingly, we believe there are no other-than-temporary impairments on these securities and have not recorded a provision for impairment.

     We use a market approach to value our Level 2 investments as described in the table below. The disclosed fair value related to our investments is based primarily on the reported fair values in our period-end brokerage statements. We independently validate these fair values using available market quotes and other information.

     The following table represents the fair value hierarchy for our financial assets measured at fair value on a recurring basis as of June 30, 2011 and December 31, 2010 (in thousands):

	Level 1		Level 2		Level 3		Total
As of June 30, 2011:
Money market funds	$	10,594	$	—	$	—	$	10,594
U.S. corporate commercial paper		—		101,434		—		101,434
Corporate notes and bonds		—		360,536		—		360,536
Obligations of U.S. government agencies		—		8,251		—		8,251
Cash equivalents and available-for-sale investments	$	10,594	$	470,221	$	—	$	480,815
Cash								1,032
Cash, cash equivalents, and available-for-sale investments							$	481,847
As of December 31, 2010:
Money market funds	$	16,028	$	—	$	—	$	16,028
U.S. corporate commercial paper		—		82,361		—		82,361
Corporate notes and bonds		—		190,527		—		190,527
Obligations of U.S. government agencies		—		25,289		—		25,289
Cash equivalents and available-for-sale investments	$	16,028	$	298,177	$	—	$	314,205
Cash								1,727
Cash, cash equivalents, and available-for-sale investments							$	315,932

Level 1 —	Quoted prices in active markets for identical assets or liabilities.
Level 2 —	Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
Level 3 —	Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.