Cash, Cash Equivalents and Short-Term Marketable Securities - Amortized Cost and Estimated Fair Value of Cash Equivalents and Marketable Securities (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Apr. 01, 2012
Less than 1 year, Amortized Cost	$ 55,093	$ 48,978
Less than 1 year, Fair Value	55,117	49,011
Due in 1 to 5 years, Amortized Cost	136,222	141,124
Due in 1 to 5 years, Fair Value	136,963	141,745
Total, Amortized Cost	191,315	190,102
Fair Value	$ 192,080	$ 190,756

Cash, Cash Equivalents and Short-Term Marketable Securities - Amortized Cost and Estimated Fair Value of Cash Equivalents and Marketable Securities (Detail) (USD $)
In Thousands, unless otherwise specified

Sep. 30, 2012

Apr. 01, 2012

$ 55,093

$ 48,978

Less than 1 year, Fair Value

55,117

49,011

Due in 1 to 5 years, Amortized Cost

136,222

141,124

Due in 1 to 5 years, Fair Value

136,963

141,745

Total, Amortized Cost

191,315

190,102

Fair Value

$ 192,080

$ 190,756

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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- Definition

Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the second fiscal year through the fifth fiscal year following the latest fiscal year. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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- Definition

Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the next fiscal year following the latest fiscal year. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents investment securities as of the balance sheet date which may include marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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