Investments (Tables)

12 Months Ended

Dec. 31, 2013

Investments, Debt and Equity Securities [Abstract]

Investment

Marketable securities at December 31, 2013, consisted of the following:

	Cost			Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(in thousands)
Short-term deposits	$	60,909		$	—	$	—		$	60,909
Mutual funds	15,722			5,061		—			20,783
United States government securities	50,356			23		—			50,379
Corporate securities	69,806			9,961		(5,208		)	74,559
Corporate obligations	31,356			885		(276		)	31,965
Commercial paper	1,799			—		—			1,799
Total available-for-sale securities	229,948			15,930		(5,484		)	240,394
Amounts classified as cash equivalents	(61,909		)	—		—			(61,909		)
Amounts classified as marketable securities	$	168,039		$	15,930	$	(5,484	)	$	178,485

Marketable securities at December 31, 2012, consisted of the following:

	Cost			Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(in thousands)
Short-term deposits	$	48,596		$	—	$	—		$	48,596
Mutual funds	10,368			1,452		—			11,820
United States government securities	99,299			178		—			99,477
Corporate securities	20,842			1,255		(1,980		)	20,117
Corporate obligations	48,708			283		(277		)	48,714
Commercial paper	22,275			16		—			22,291
Total available-for-sale securities	250,088			3,184		(2,257		)	251,015
Amounts classified as cash equivalents	(51,887		)	—		—			(51,887		)
Amounts classified as marketable securities	$	198,201		$	3,184	$	(2,257	)	$	199,128

Available-for-sale Securities

Gross realized gains and losses from sales of marketable securities, all of which are reported as a component of "Other income (expense), net" in the consolidated statements of operations for the years ended December 31, 2013, 2012, and 2011, were as follows:

	Fiscal Year Ended December 31, 2013
	2013			2012			2011
Gross realized gains	$	6,984		$	628		$	1,993
Gross realized losses	(4,376		)	(346		)	(280		)
Realized gains, net	$	2,608		$	282		$	1,713

Schedule of Unrealized Loss on Investments

The fair value of the Company’s marketable securities with unrealized losses at December 31, 2013, and the duration of time that such losses had been unrealized, were as follows:

	Less than 12 Months					12 Months or Greater					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
	(in thousands)
Corporate obligations	$	10,477	$	(276	)	$	—	$	—		$	10,477	$	(276	)
Corporate securities	15,609		(4,757		)	803		(451		)	16,412		(5,208		)
Total	$	26,086	$	(5,033	)	$	803	$	(451	)	$	26,889	$	(5,484	)

The fair value of the Company’s marketable securities with unrealized losses at December 31, 2012, all of which had been unrealized for a period of less than twelve months, were as follows:

	Fair Value		Gross Unrealized Losses
	(in thousands)
Corporate securities	$	6,389	$	(1,980	)
Corporate obligations	14,252		(277		)
Total	$	20,641	$	(2,257	)

Investments Classified by Contractual Maturity Date

The amortized cost and estimated fair value of available-for-sale securities at December 31, 2013, by contractual maturity, were as follows:

	Cost		Estimated  Fair Value
	(in thousands)
Debt securities:
Mature in one year or less	$	40,580	$	40,617
Mature after one year through three years	21,097		21,251
Mature in more than three years	21,833		22,274
Total debt securities	83,510		84,142
Securities with no contractual maturities	146,438		156,252
Total	$	229,948	$	240,394