Investments in Cash Equivalents and Marketable Securities (Tables)

9 Months Ended

Oct. 01, 2011

Investments, Debt and Equity Securities [Abstract]

Available-for-sale Securities

The cost, net unrealized holding gains, net unrealized holding losses and fair value of available-for-sale investments by types and classes of security at October 1, 2011 consisted of the following:

At October 1, 2011	Cost		Net unrealized holding gains		Net unrealized holding losses			Fair Value
Available-for-sale-included in cash equivalents:
Corporate debt securities	$	29,273	$	—	$	—		$	29,273
Money market funds and other	46,930		—		—			46,930
U.S. government-sponsored enterprise securities	10,900		—		(2		)	10,898
U.S. treasury securities	4,000		—		—			4,000
Available-for-sale-included in short-term marketable securities:
Municipal notes	9,295		—		—			9,295
U.S. government-sponsored enterprise securities	10,001		—		(1		)	10,000
U.S. treasury securities	6,024		2		—			6,026
Corporate debt securities	8,018		—		(1		)	8,017
Certificates of deposit	206		—		—			206
	$	124,647	$	2	$	(4	)	$	124,645

The cost, net unrealized holding gains, net unrealized holding losses and fair value of available-for-sale investments by types and classes of security at December 31, 2010 consisted of the following:

At December 31, 2010	Cost		Net unrealized holding gains		Net unrealized holding losses			Fair Value
Available-for-sale-included in cash equivalents:
U.S. treasury securities	$	5,500	$	—	$	—		$	5,500
Certificates of deposit	325		—		—			325
Money market funds and other	114,217		—		—			114,217
Available-for-sale-included in short-term marketable securities:
U.S. treasury securities	3,115		—		(2		)	3,113
U.S. government-sponsored enterprise securities	26,366		4		—			26,370
Certificate of deposits	1,709		—		—			1,709
	$	151,232	$	4	$	(2	)	$	151,234