INVESTMENTS AND FAIR VALUE MEASUREMENTS

Available-For-Sale

The following is a summary of available-for-sale securities as of December 28, 2013 and March 30, 2013 (in thousands):



	Available-for-Sale Securities
	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
December 28, 2013
U.S. government/agency securities	$	88,055	$	4	$	—		$	88,059
Auction rate securities	2,150		—		—			2,150
Money market funds	38,794		—		—			38,794
	$	128,999	$	4	$	—		$	129,003
March 30, 2013
U.S. government/agency securities	$	77,988	$	3	$	(4	)	$	77,987
Auction rate securities	2,150		—		—			2,150
Money market funds	26,328		—		—			26,328
	$	106,466	$	3	$	(4	)	$	106,465

The estimated fair value of available-for-sale securities was based on the prevailing market values on December 28, 2013 and March 30, 2013. We determine the cost of an investment sold based on the specific identification method.

The gross realized gains and losses recognized on available-for-sale securities for both the three and nine months ended December 28, 2013 and December 29, 2012, were insignificant.

No available-for-sale investments were in a continuous unrealized loss position for fewer than 12 months as of December 28, 2013. The available-for-sale investments that were in a continuous unrealized loss position for fewer than 12 months as of March 30, 2013 consisted of U.S. government/agency securities with gross unrealized losses of less than $0.1 million and an aggregate fair value of approximately $14.0 million. No available-for-sale investments were in a continuous unrealized loss position for 12 months or greater as of December 28, 2013 or as of March 30, 2013.

The amortized cost of available-for-sale investments in debt securities with contractual maturities is as follows (in thousands):



	December 28, 2013				March 30, 2013
	Cost		Estimated Fair Value		Cost		Estimated Fair Value
Due in less than one year	$	126,849	$	126,853	$	104,316	$	104,315
Due after ten years	2,150		2,150		2,150		2,150
Total investments in debt securities	$	128,999	$	129,003	$	106,466	$	106,465

Fair Value Measurements

On a quarterly basis, the Company measures the fair value of its marketable securities, which are comprised of U.S. government/agency securities, auction rate securities (ARS), and money market funds. Marketable securities are reported at fair value in cash and cash equivalents, short-term investments and long-term investments on the Company’s Condensed Consolidated Balance Sheet. The related unrealized gains and losses are included in accumulated other comprehensive loss, a component of shareholders’ equity, net of tax.

Recurring Fair Value Measurements

The fair value of the financial assets measured at fair value on a recurring basis was determined using the following levels of inputs as of December 28, 2013 and March 30, 2013 (in thousands):



	Total		Quoted Prices In Active Markets For Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
December 28, 2013
U.S. government/agency securities	$	88,059	$	88,059	$	—
Auction rate securities	2,150		—		2,150
Money market funds	38,794		38,794		—
	$	129,003	$	126,853	$	2,150
March 30, 2013
U.S. government/agency securities	$	77,987	$	77,987	$	—
Auction rate securities	2,150		—		2,150
Money market funds	26,328		26,328		—
	$	106,465	$	104,315	$	2,150

ARS are debt instruments with interest rates that reset through periodic short-term auctions. The Company’s Level 2 ARS are valued at par based on quoted prices for identical or similar instruments in markets that are not active. As of December 28, 2013 and March 30, 2013, the Company did not have any Level 3 securities.

Nonrecurring Fair Value Measurements

The Company's non-financial assets, such as intangible assets and property and equipment, are measured at fair value when there is an indicator of impairment, and recorded at fair value only when an impairment charge is recognized. During the first quarter of fiscal 2014, the Company recorded a $1.7 million impairment of certain property and equipment as a result of the phase out of manufacturing and the then-pending sale of its U.K. manufacturing facility. As of June 29, 2013, the fair value of these impaired assets was estimated to be $0.8 million using a significant Level 3 unobservable input (market valuation approach). The market valuation approach uses prices and other relevant information generated primarily by recent market transactions involving similar or comparable assets, as well as the Company's experience. During the second quarter of fiscal 2014, the Company sold its U.K. manufacturing facility, which resulted in a loss on these impaired assets of $0.6 million.

Other Fair Value Disclosures

The carrying values of cash and cash equivalents, accounts receivable, accounts payable and other accrued liabilities approximate fair values because of the relatively short-term maturities of these instruments.

The fair value of the Company’s 2014 Notes is measured using a Level 1 input obtained from the PORTAL Market and is disclosed in Note 4 to the Condensed Consolidated Financial Statements.