4. Cash Equivalents and Investments

As of June 30, 2014, and December 31, 2013, we had invested our excess cash balances primarily in money market funds, and a corporate security. Our securities are classified as available-for-sale and are carried at estimated fair value, with unrealized gains and losses reported in accumulated other comprehensive income (loss) in stockholders’ equity, net of estimated taxes. See Note 3 for fair value measurement information. The cost of securities sold is based on the specific identification method. To date, we have not experienced credit losses on investments in these instruments and we do not require collateral for our investment activities.



Summary of Cash and Available-For-Sale Securities	Adjusted Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value		Cash and Cash Equivalents		Short-Term Investments
(In thousands)
June 30, 2014
Cash	$	59,418	$	—	$	—		$	59,418	$	59,418	$	—
Money market funds	155,107		—		—			155,107		155,107		—
Corporate security	3,500		—		(257		)	3,243		—		3,243
Total	$	218,025	$	—	$	(257	)	$	217,768	$	214,525	$	3,243

December 31, 2013
Cash	$	8,332	$	—	$	—		$	8,332	$	8,332	$	—
Money market funds	85,970		—		—			85,970		85,970		—
Corporate security	3,500		1,738		—			5,238		—		5,238
Total	$	97,802	$	1,738	$	—		$	99,540	$	94,302	$	5,238

No gains or losses on sales of available-for-sale securities were recognized for the three and six months ended June 30, 2014 and 2013.

The unrealized gain (loss) on investments included in other comprehensive income (loss), net of estimated taxes, was approximately ($167,000) and $1,129,000 as of June 30, 2014, and December 31, 2013, respectively. No significant facts or circumstances have arisen to indicate that there has been any deterioration in the creditworthiness of the issuers of these securities. Based on our review of these securities, we believe we had no other-than-temporary impairments on these securities as of June 30, 2014, and December 31, 2013.