Cash, Cash Equivalents and Short-Term Investments

6 Months Ended

Jun. 25, 2011

Cash, Cash Equivalents and Short-Term Investments [Abstract]

Cash, Cash Equivalents and Short-Term Investments

3. Cash, Cash Equivalents and Short-Term Investments

As of June 25, 2011, and December 25, 2010, our cash, cash equivalents, and short-term investments consisted primarily of cash, corporate debt securities, government and government agency securities, state and municipal securities, money market funds and other investment grade securities. We do not hold investment securities for trading purposes. All short-term investments are classified as available-for-sale and recorded at fair value. Investment securities are exposed to market risk due to changes in interest rates and credit risk and we monitor credit risk and attempt to mitigate exposure by making high-quality investments and through investment diversification.

Gains and losses on investments are calculated using the specific-identification method and are recognized during the period in which the investment is sold or when an investment experiences an other-than-temporary decline in value. Factors that could indicate an impairment exists include, but are not limited to: earnings performance, changes in credit rating or adverse changes in the regulatory or economic environment of the asset. Gross realized gains and losses on sales of short-term investments are included in interest income. Realized gains and losses for the periods presented were not significant.

Investments that we have classified as short-term, by security type, are as follows (in thousands):

	June 25, 2011
			Gross		Gross		Estimated
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses (1)		Value
U.S. Treasury securities	$	4,768	$	14	$	—	$	4,782
Corporate debt securities (2)		23,790		16		—		23,806
Municipal securities		9,560		—		—		9,560
Government-sponsored enterprise securities		13,806		51		1		13,856
	$	51,924	$	81	$	1	$	52,004

	December 25, 2010
			Gross		Gross		Estimated
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses (1)		Value
U.S. Treasury securities	$	6,778	$	9	$	—	$	6,787
Corporate debt securities (2)		18,010		28		4		18,034
Municipal securities		11,102		1		—		11,103
Government-sponsored enterprise securities		15,105		8		20		15,093
Bank certificates of deposit		1,000		—		—		1,000
Asset-backed securities		236		1		—		237
	$	52,231	$	47	$	24	$	52,254

(1)	As of June 25, 2011, and December 25, 2010, the cost and fair value of investments with loss positions was $5.9 million and $16.1 million, respectively. We evaluated the nature of these investments, credit worthiness of the issuer and the duration of these impairments to determine if an other-than-temporary decline in fair value had occurred and concluded that these losses were temporary.
(2)	Corporate debt securities include investments in financial, insurance, and corporate institutions. No single issuer represents a significant portion of the total corporate debt securities portfolio.

Effective maturities of short-term investments at June 25, 2011 and December 25, 2010, were as follows (in thousands):

	June 25, 2011				December 25, 2010
	Amortized		Estimated		Amortized		Estimated
	Cost		Fair Value		Cost		Fair Value
Due in one year or less	$	41,097	$	41,133	$	34,891	$	34,918
Due after one year through two years		10,827		10,871		17,104		17,099
Asset-backed securities not due at a single maturity date		—		—		236		237
	$	51,924	$	52,004	$	52,231	$	52,254

Our municipal securities include variable rate demand notes which can be put (sold at par) typically on a daily basis with settlement periods ranging from the same day to one week and have varying contractual maturities through 2037. These securities can be used for short-term liquidity needs and are held for limited periods of time. At June 25, 2011 and December 25, 2010 these securities had amortized cost and fair value of $7.1 million and $7.5 million, respectively, and are included in “Due in one year or less” in the table above.

Accounting standards pertaining to fair value measurements establish a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. When available, we use quoted market prices to determine the fair value of our investments, and they are included in Level 1. When quoted market prices are unobservable, we use quotes from independent pricing vendors based on recent trading activity and other relevant information, and they are included in Level 2.

The following table summarizes, by major security type, our assets that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy (in thousands):

	Fair value measurements at June 25, 2011 using:
							Total estimated
	Level 1		Level 2		Level 3		fair value
Cash	$	18,908	$	—	$	—	$	18,908
U.S. Treasury securities		4,782		—		—		4,782
Corporate debt securities		—		25,304		—		25,304
Municipal securities		—		10,110		—		10,110
Government-sponsored enterprise securities		—		13,856		—		13,856
Money market funds		—		27,432		—		27,432
Bank certificates of deposit		—		1,000		—		1,000
	$	23,690	$	77,702	$	—	$	101,392

	Fair value measurements at December 25, 2010 using:
							Total estimated
	Level 1		Level 2		Level 3		fair value
Cash	$	18,842	$	—	$	—	$	18,842
U.S. Treasury securities		6,787		—		—		6,787
Corporate debt securities		—		21,432		—		21,432
Municipal securities		—		11,852		—		11,852
Government-sponsored enterprise securities		—		15,093		—		15,093
Money market funds		—		22,932		—		22,932
Bank certificates of deposit		—		1,000		—		1,000
Asset-backed securities		—		237		—		237
	$	25,629	$	72,546	$	—	$	98,175

When available, we use quoted market prices to determine the fair value of our investments, and they are included in Level 1. When quoted market prices are unobservable, we use quotes from independent pricing vendors based on recent trading activity and other relevant information. These investments are included in Level 2 and primarily comprise our money market funds and our portfolio of corporate debt securities, bank certificates of deposit, government-sponsored enterprise, municipal securities and asset-backed securities.