Note 6. Cash, Cash Equivalents and Short Term Marketable Securities (Tables)

12 Months Ended

Mar. 31, 2013

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

	March 31, 2013
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	5,042	$	—	$	—	$	5,042	3	%
U.S. government and agency securities		22,460		19,261		—		41,721	21	%
State and local government securities		—		2,935		—		2,935	1	%
Corporate bonds and securities		274		91,955		—		92,229	47	%
Asset-backed securities		—		30,966		—		30,966	16	%
Mortgage-backed securities		—		22,736		—		22,736	12	%
Total investment assets	$	27,776	$	167,853	$	—	$	195,629	100	%
Liabilities:
Acquisition-related contingent consideration	$	—	$	—	$	10,138	$	10,138	100	%

	April 1, 2012
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	3,088	$	—	$	—	$	3,088	2	%
U.S. government and agency securities		16,282		27,954		—		44,236	23	%
State and local government securities		—		590		—		590	—
Corporate bonds and securities		—		69,234		—		69,234	36	%
Asset-backed securities		—		26,364		—		26,364	14	%
Mortgage-backed securities		—		47,244		—		47,244	25	%
Total investment assets	$	19,370	$	171,386	$	—	$	190,756	100	%

Marketable Securities [Table Text Block]

	March 31, 2013		April 1, 2012
Cash and cash equivalents
Cash in financial institutions	$	9,676	$	5,626
Cash equivalents
Money market funds		5,042		3,088
Total cash and cash equivalents	$	14,718	$	8,714
Short-term marketable securities
U.S. government and agency securities	$	41,721	$	44,236
State and local government securities		2,935		590
Corporate bonds and securities		92,229		69,234
Asset-backed securities		30,966		26,364
Mortgage-backed securities		22,736		47,244
Total short-term marketable securities	$	190,587	$	187,668

Fair Value Inputs, Assets, Quantitative Information [Table Text Block]

	Fair Value (in thousands)		Valuation Technique	Significant Unobservable Input	Range (in thousands)
As of March 31, 2013
Acquisition-related contingent consideration	$	10,138	Combination of income and marketable approach	Revenue (in “000’s)	$18,817	-	$37,633
				Discount rate (in %)		5%
				Probability of occurrence (in %)	40%	-	65%

Realized Gain (Loss) on Investments [Table Text Block]

	Fiscal Years Ended
	March 31, 2013			April 1, 2012			March 27, 2011
Gross realized gains	$	871		$	799		$	1,271
Gross realized losses		(953	)		(1,098	)		(1,173	)
Net realized gains (losses)	$	(82	)	$	(299	)	$	98

Available-for-sale Securities [Table Text Block]

	March 31, 2013
	Amortized Cost		Unrealized Gross Gains(1)		Unrealized Gross Losses(1)			Fair Value
Money market funds	$	5,042	$	—	$	—		$	5,042
U.S. government and agency securities		41,694		27		—			41,721
State and local government securities		2,927		10		(2	)		2,935
Corporate bonds and securities		92,059		215		(45	)		92,229
Asset-backed securities		30,932		61		(27	)		30,966
Mortgage-backed securities		22,646		194		(104	)		22,736
Total investments	$	195,300	$	507	$	(178	)	$	195,629

	April 1, 2012
	Amortized Cost		Unrealized Gross Gains(1)		Unrealized Gross Losses(1)			Fair Value
Money market funds	$	3,088	$	—	$	—		$	3,088
U.S. government and agency securities		44,077		189		(30	)		44,236
State and local government securities		610		—		(20	)		590
Corporate bonds and securities		68,857		410		(33	)		69,234
Asset-backed securities		26,353		55		(44	)		26,364
Mortgage-backed securities		47,117		286		(159	)		47,244
Total investments	$	190,102	$	940	$	(286	)	$	190,756

Schedule Of Amortized Cost and Fair Market Value [Table Text Block]

	March 31, 2013				April 1, 2012
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Less than 1 year	$	61,011	$	61,029	$	48,978	$	49,011
Due in 1 to 5 years		134,289		134,600		141,124		141,745
Total	$	195,300	$	195,629	$	190,102	$	190,756

Schedule of Unrealized Loss on Investments [Table Text Block]

	March 31, 2013
	Less than 12 months					12 months or greater					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
State and local government securities		—		—			404		(2	)		404		(2	)
Corporate bonds and securities		29,609		(42	)		497		(3	)		30,106		(45	)
Asset-backed securities		10,008		(17	)		1,241		(10	)		11,249		(27	)
Mortgage-backed securities		2,911		(39	)		3,263		(65	)		6,174		(104	)
Total	$	42,528	$	(98	)	$	5,405	$	(80	)	$	47,933	$	(178	)

	April 1, 2012
	Less than 12 months					12 months or greater					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
U.S. government and agency securities	$	15,585	$	(30	)	$	—	$	—		$	15,585	$	(30	)
State and local government securities		590		(20	)		—		—			590		(20	)
Corporate bonds and securities		11,685		(33	)		—		—			11,685		(33	)
Asset-backed securities		3,516		(5	)		3,786		(39	)		7,302		(44	)
Mortgage-backed securities		16,435		(108	)		2,417		(51	)		18,852		(159	)
Total	$	47,811	$	(196	)	$	6,203	$	(90	)	$	54,014	$	(286	)