Cash, Cash Equivalents and Investments (Tables)

3 Months Ended

Apr. 01, 2012

Cash, Cash Equivalents, and Investments [Abstract]

Components of cash, cash equivalents and investments

	April 1, 2012		December 31, 2011
Cash	$	39,824	$	36,404
Money market instruments		1,735		1,699
Cash and cash equivalents		41,559		38,103
Corporate bonds		61,517		55,570
Municipal bonds		57,862		54,036
Agency bonds		27,298		27,545
Sovereign bonds		6,222		4,016
Covered bonds		4,443		1,319
Asset-backed securities		1,867		—
Treasury bills		—		1,945
Short-term investments		159,209		144,431
Corporate bonds		71,969		59,902
Municipal bonds		67,532		69,680
Sovereign bonds		18,279		22,355
Agency bonds		13,987		12,335
Asset-backed securities		3,526		—
Covered bonds		1,740		4,701
Treasury bills		999		—
Limited partnership interest (accounted for using cost method)		5,933		5,933
Long-term investments		183,965		174,906
	$	384,733	$	357,440

Summary of available-for-sale investments

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Short-term:
Corporate bonds	$	61,459	$	188	$	(130	)	$	61,517
Municipal bonds		57,774		89		(1	)		57,862
Agency bonds		27,220		87		(9	)		27,298
Sovereign bonds		6,192		30		—			6,222
Covered bonds		4,402		41		—			4,443
Asset-backed securities		1,865		2		—			1,867
Long-term:
Corporate bonds		71,175		795		(1	)		71,969
Municipal bonds		67,265		295		(28	)		67,532
Sovereign bonds		18,019		260		—			18,279
Agency bonds		13,988		34		(35	)		13,987
Asset-backed securities		3,520		6		—			3,526
Covered bonds		1,722		18		—			1,740
Treasury bills		998		1		—			999
	$	335,599	$	1,846	$	(204	)	$	337,241

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

	Unrealized Loss Position For:
	Less than 12 Months					12 Months or Greater					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Municipal bonds	$	19,415	$	(29	)	$	—	$	—		$	19,415	$	(29	)
Agency bonds		11,772		(44	)		—		—			11,772		(44	)
Corporate bonds		3,935		(2	)		8,758		(129	)		12,693		(131	)
	$	35,122	$	(75	)	$	8,758	$	(129	)	$	43,880	$	(204	)

Effective maturity dates of available-for-sale investments

	<1 Year		1-2 Years		2-3 Years		3-4 Years		4-5 Years		5-7 Years		Total
Corporate bonds	$	61,517	$	37,014	$	25,674	$	4,868	$	4,413	$	—	$	133,486
Municipal bonds		57,862		21,567		29,861		10,489		5,091		524		125,394
Agency bonds		27,298		10,515		2,101		1,371		—		—		41,285
Sovereign bonds		6,222		4,587		8,732		984		3,976		—		24,501
Covered bonds		4,443		1,740		—		—		—		—		6,183
Asset-backed securities		1,867		—		3,026		—		—		500		5,393
Treasury bills		—		999		—		—		—		—		999
	$	159,209	$	76,422	$	69,394	$	17,712	$	13,480	$	1,024	$	337,241

Summary of available-for-sale investments held in its international portfolio

Short-term	Corporate bonds		Agency bonds		Sovereign bonds		Asset- backed securities		Covered bonds		Total
Australia	$	3,399	$	—	$	—	$	—	$	—	$	3,399
Austria		—		817		—		—		—		817
Canada		1,993		2,402		—		—		—		4,395
Cayman Islands		2,076		—		—		—		—		2,076
France		2,072		—		—		—		—		2,072
Germany		9,125		2,015		2,177		—		—		13,317
Great Britain		11,408		5,613		—		1,867		1,353		20,241
Japan		1,697		—		—		—		—		1,697
Jersey		1,341		—		—		—		—		1,341
Netherlands		4,266		8,092		4,046		—		1,721		18,125
Norway		—		—		—		—		1,369		1,369
Supranational		—		3,009		—		—		—		3,009
Sweden		3,038		3,676		—		—		—		6,714
Switzerland		3,679		—		—		—		—		3,679
United States		13,956		1,675		—		—		—		15,631
Total	$	58,050	$	27,299	$	6,223	$	1,867	$	4,443	$	97,882

Long-term	Corporate bonds		Agency bonds		Sovereign bonds		Covered bonds		Total
Austria	$	—	$	4,798	$	—	$	—	$	4,798
Belgium		1,824		—		—		—		1,824
Canada		1,119		2,279		—		—		3,398
Denmark		1,810		—		—		1,740		3,550
Finland		—		—		1,911		—		1,911
France		2,112		—		—		—		2,112
Germany		6,784		1,371		16,367		—		24,522
Great Britain		10,615		—		—		—		10,615
Hong Kong		1,749		—		—		—		1,749
Japan		1,891		—		—		—		1,891
Jersey		1,766		—		—		—		1,766
Netherlands		5,079		—		—		—		5,079
Sweden		—		2,101		—		—		2,101
United States		8,491		2,437		—		—		10,928
Total	$	43,240	$	12,986	$	18,278	$	1,740	$	76,244