v2.4.0.6

Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2011

Marketable Securities

Schedule of estimated fair value of available-for-sale debt securities and money market funds

		December 31, 2011												December 31, 2010
(in thousands)		Amortized Cost			Gross Unrealized Gains			Gross Unrealized Losses			Estimated Fair Value			Amortized Cost			Gross Unrealized Gains			Gross Unrealized Losses			Estimated Fair Value
U.S. government securities		$	66,150		$	24		$	—		$	66,174		$	25,966		$	10		$	—		$	25,976
U.S. government agencies			93,183			9			(17	)		93,175			54,625			30			(7	)		54,648
U.S. corporate notes			2,707			—			(2	)		2,705			34,695			9			(9	)		34,695
U.S. commercial paper			34,973			3			—			34,976			97,221			—			—			97,221
Money market funds			38,721			—			—			38,721			91,805			—			—			91,805
Total			235,734			36			(19	)		235,751			304,312			49			(16	)		304,345
Less amounts classified as cash equivalents			(38,721	)		—			—			(38,721	)		(157,151	)		—			—			(157,151	)
Less amounts classified as restricted cash			(893	)		—			—			(893	)		(893	)		—			—			(893	)
Amounts classified as marketable securities		$	196,120		$	36		$	(19	)	$	196,137		$	146,268		$	49		$	(16	)	$	146,301

Schedule of net realized gains (losses) on marketable securities

		Year Ended December 31,
(in thousands)		2011			2010			2009
Realized gains		$	—		$	3		$	—
Realized losses			(2	)		—			—
Net realized gains (losses)		$	(2	)	$	3		$	—

Summary of marketable securities with unrealized losses

		In loss position for less than 12 months						In loss position for more than 12 months						Total
(in thousands)		Fair Value			Estimated Gross Unrealized Losses			Fair Value			Estimated Gross Unrealized Losses			Fair Value			Estimated Gross Unrealized Losses
U.S. government agencies		$	47,807		$	(17	)	$	—		$	—		$	47,807		$	(17	)
U.S. corporate notes			2,754			(2	)		—			—			2,754			(2	)
Total		$	50,561		$	(19	)	$	—		$	—		$	50,561		$	(19	)

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Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value.

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Tabular disclosure of the proceeds from sales of available-for-sale securities and the gross realized gains and gross realized losses that have been included in earnings as a result of those sales.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Topic 320

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For all investments in an unrealized loss position, including those for which other-than-temporary impairments have not been recognized in earnings (including investments for which a portion of an other-than-temporary impairment has been recognized in other comprehensive income), a tabular disclosure of the aggregate related fair value of investments with unrealized losses and the aggregate amount of unrealized losses (that is, the amount by which amortized cost basis exceeds fair value).

+ References

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