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

3 Months Ended

Mar. 31, 2012

Cash, Cash Equivalents, and Available-For-Sales 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
	March 31, 2012		December 31, 2011
Cash and cash equivalents	$	148,485	$	15,312
Short-term investments		233,624		225,856
Long-term investments		116,732		173,768
Total cash, cash equivalents, and available-for-sale investments	$	498,841	$	414,936

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

	Estimated Fair Value at
	March 31, 2012		December 31, 2011
Corporate notes and bonds	$	310,389	$	344,427
U.S. corporate commercial paper		24,456		9,464
Obligations of U.S. government agencies		14,003		44,230
Obligations of U.S. states and municipalities		1,508		1,503
Cash and money market funds		148,485		15,312
Total cash, cash equivalents, and available-for-sale investments	$	498,841	$	414,936

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
	March 31, 2012		December 31, 2011
Less than one year	$	233,624	$	213,386
Greater than one year but less than two years		116,732		186,238
Total available-for-sale investments	$	350,356	$	399,624

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 remaining maturities of less than one year, or where our intent is to use the investments to fund current operations, or to make them available for current operations, are classified as short-term investments.

Gross unrealized gains and losses were not significant at March 31, 2012 and December 31, 2011.

During the three month periods ended March 31, 2012 and 2011, we sold available-for-sale securities totaling nil and $61.4 million, respectively, and realized gains and losses were not significant in any of those periods. The cost of securities sold is based on the specific identification method.

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, which are based on market prices from a variety of industry standard data providers. We independently validate these fair values using available market quotes and other information. During the three month periods ended March 31, 2012 and 2011, there were no transfers between Level 1 and Level 2 of the fair value hierarchy.

The following table represents the fair value hierarchy for our financial assets measured at fair value on a recurring basis as of March 31, 2012 and December 31, 2011 (in thousands):

As of March 31, 2012:	Level 1		Level 2		Level 3		Total
Money market funds	$	147,515	$	—	$	—	$	147,515
U.S. corporate commercial paper		—		24,456		—		24,456
Corporate notes and bonds		—		310,389		—		310,389
Obligations of U.S. government agencies		—		14,003		—		14,003
Obligations of U.S. states and municipalities		—		1,508		—		1,508
Cash equivalents and available-for-sale investments	$	147,515	$	350,356	$	—	$	497,871
Cash								970
Cash, cash equivalents, and available-for-sale investments							$	498,841

As of December 31, 2011:	Level 1		Level 2		Level 3		Total
Money market funds	$	13,950	$	—	$	—	$	13,950
U.S. corporate commercial paper		—		9,464		—		9,464
Corporate notes and bonds		—		344,427		—		344,427
Obligations of U.S. government agencies		—		44,230		—		44,230
Obligations of U.S. states and municipalities		—		1,503		—		1,503
Cash equivalents and available-for-sale investments	$	13,950	$	399,624	$	—	$	413,574
Cash								1,362
Cash, cash equivalents, and available-for-sale investments							$	414,936

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.