Cash, Cash Equivalents and Investments (Tables)

9 Months Ended

Oct. 02, 2011

Cash, Cash Equivalents, and Investments [Abstract]

Components of cash, cash equivalents and investments

	October 2,		December 31,
	2011		2010
Cash	$	28,038	$	26,650
Money market instruments		2,137		6,553
Cash and cash equivalents		30,175		33,203
Treasury bills		—		2,494
Municipal bonds		49,626		75,457
Corporate bonds		60,123		34,543
Agency bonds		31,276		15,979
Sovereign bonds		—		19,350
Covered bonds		1,384		—
Short-term investments		142,409		147,823
Municipal bonds		70,583		34,794
Corporate bonds		65,206		36,762
Agency bonds		13,894		21,025
Sovereign bonds		12,971		—
Covered bonds		4,934		3,541
Limited partnership interest (accounted for using cost method)		5,933		5,933
Long-term investments		173,521		102,055
	$	346,105	$	283,081

Summary of available-for-sale investments

			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses			Fair Value
Short-term:
Municipal bonds	$	49,575	$	57	$	(6	)	$	49,626
Corporate bonds		60,879		9		(765	)		60,123
Agency bonds		31,289		15		(28	)		31,276
Covered bonds		1,384		—		—			1,384
Long-term:
Municipal bonds		70,413		227		(57	)		70,583
Corporate bonds		65,143		162		(99	)		65,206
Agency bonds		13,878		27		(11	)		13,894
Sovereign bonds		12,768		203		—			12,971
Covered bonds		4,919		15		—			4,934
	$	310,248	$	715	$	(966	)	$	309,997

Gross unrealized losses and fair value for available-for-sale investments

	Unrealized Loss Position For:
	Less than 12 Months					12 Months or Greater					Total
			Unrealized					Unrealized					Unrealized
	Fair Value		Losses			Fair Value		Losses			Fair Value		Losses
Municipal bonds	$	31,230	$	(62	)	$	704	$	(1	)	$	31,934	$	(63	)
Corporate bonds		56,169		(839	)		18,630		(25	)		74,799		(864	)
Agency bonds		19,663		(30	)		8,608		(9	)		28,271		(39	)
	$	107,062	$	(931	)	$	27,942	$	(35	)	$	135,004	$	(966	)

Effective maturity dates of available-for-sale investments

	<1 Year		1-2 Years		2-3 Years		3-4 Years		4-5 Years		Total
Municipal bonds	$	49,626	$	27,175	$	19,999	$	14,585	$	8,824	$	120,209
Corporate bonds		60,123		36,032		24,312		1,221		3,641		125,329
Agency bonds		31,276		11,499		2,395		—		—		45,170
Sovereign bonds		—		4,220		6,986		—		1,765		12,971
Covered bonds		1,384		4,934		—		—		—		6,318
	$	142,409	$	83,860	$	53,692	$	15,806	$	14,230	$	309,997