Note 2—Cash Equivalents and Marketable Securities

Cash, cash equivalents and marketable securities primarily consist of money market mutual funds, US government and US Government Sponsored Entities (GSE’s), foreign government debt securities and high credit quality corporate debt securities. All marketable securities were considered available-for-sale and were carried at fair value on the Company’s condensed consolidated balance sheet. Short-term marketable securities mature twelve months or less, and long-term marketable securities mature greater than twelve months, from the date of the condensed consolidated balance sheet.

At September 30, 2013, the Company had no marketable securities.

Marketable securities at December 31, 2012 are summarized as follows (in thousands):

					Gross			Gross
					Unrealized			Unrealized
			Gross		Losses			Losses
	Amortized		Unrealized		Less than			12 Months		Aggregate
Balance at December 31, 2012	Cost		Gains		12 Months			or Longer		Fair Value

Corporate debt securities	$	110,540	$	13	$	(45	)	$	—	$	110,508
US government debt securities	59,811		7		(3		)	—		59,815
Foreign government debt securities	2,415		6		—			—		2,421
Total	$	172,766	$	26	$	(48	)	$	—	$	172,744

Unrealized gains and losses are a component of “Accumulated other comprehensive income” in the accompanying condensed consolidated balance sheet.

During the nine months ended September 30, 2013 and 2012, $228.6 million and $69.6 million, respectively, of marketable securities were sold or matured, which did not have any associated material gross realized gains or losses.