Cash Equivalents

The Company had $263,967 and $695,612 of held-to-maturity securities with original maturities of three months or less, primarily consisting of corporate debt securities, classified as cash equivalents at December 31, 2013 and 2012, respectively. The Company’s investments in held-to-maturity securities are held at amortized cost, which approximates fair value.

Current Marketable Securities

Investments in current marketable securities at December 31 were classified as follows:



	2013		2012
Available-for-sale securities	$	239,388	$	—
Held-to-maturity securities	—		124,873
Marketable securities	$	239,388	$	124,873

Available-for-Sale Securities

The cost, gross unrealized gains, gross unrealized losses and fair value of the Company’s available-for-sale securities were as follows:



	December 31, 2013
	Cost		Gross Unrealized Gains		Gross Unrealized Losses ⁽¹⁾			Fair Value
Debt securities
Corporate bonds	$	108,300	$	340	$	(69	)	$	108,571
U.S. government debt ⁽²⁾	106,335		60		(79		)	106,316
Asset-backed securities	24,478		34		(11		)	24,501
Total available-for-sale securities	$	239,113	$	434	$	(159	)	$	239,388

_____________


(1)	All unrealized loss positions were held at a loss for less than 12 months.


(2)	U.S. Treasury obligations, U.S. government agency obligations and U.S government agency mortgage-backed securities.

As of December 31, 2013, net unrealized gains on the Company's available-for-sale securities of $176, net of income tax expense of $99, were recorded in accumulated other comprehensive income. See Note 13 for the fair value hierarchy of the Company’s available-for-sale securities.

As of December 31, 2013, the corporate bond securities held by the Company had maturities between one month to five years, U.S. government debt securities, excluding U.S. government agency mortgage-backed securities, had maturities between three months to three years, U.S. government agency mortgage-backed securities had maturities between four to 29 years and asset-backed securities had maturities between two to seven years.

The proceeds from sales and maturities of available-for-sale securities and the gross realized gains and losses included in the consolidated statement of operations is reflected in the table below. The cost of securities sold was determined using the specific identification method.



	Year Ended December 31,
	2013
Proceeds from sales and maturities of securities	$	7,770
Gross realized gains	20
Gross realized losses	(39		)

Held-to-Maturity Securities

The Company owned held-to-maturity securities of $124,873 at December 31, 2012, consisting of short-term corporate debt securities with maturities exceeding three months at the date of acquisition. These debt securities are carried at amortized cost, which approximates their fair value.