Employee Stock Benefit Plans (Details) (Detail) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	9 Months Ended
Mar. 31, 2012	Sep. 29, 2012
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common share granted		400,646
Stock options outstanding		3,176,121
Weighted-average exercise price of stock options		12.61
Aggregate intrinsic value of stock options		1.9
Weighted average remaining contractual term stock options		5 years 3 months 18 days
Stock options outstanding, Exercisable		2,210,946
Weighted-average exercise price of stock options, Exercisable		13.42
Aggregate intrinsic value of stock options, Exercisable		1.3
Weighted average remaining contractual term stock options, Exercisable		4 years
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common share granted		442,314
Aggregate intrinsic value of stock options		6.3
Restricted stock units outstanding		673,881
Restricted stock units weighted average remaining vesting period		2 years 9 months 18 days
Restricted stock units \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum period in which vested stock become exercisable		1 year
Restricted stock units \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum period in which vested stock become exercisable		4 years
Equity based performance units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum period in which vested stock become exercisable		3 years
Number of common share granted	128,916
Award measurement period		1 year
Equity based performance units [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock granted on achievement of performance goals		0.00%
Equity based performance units [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock granted on achievement of performance goals		150.00%
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of the fair value to determine the price of common stock		85.00%
Shares available for future equity grants under the 1997 ESPP Plan		568,915
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum period in which vested stock expire		10
Shares available for future equity grants under the 2005 Equity Plan		1,902,616
Stock Option [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum period in which vested stock become exercisable		1 year
Stock Option [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum period in which vested stock become exercisable		4 years

Employee Stock Purchase Plan Shares available for future issuance.

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Percentage of the Fair Value to Determine the price of common stock.

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Share based compensation arrangement by share based payment award award measurement period.

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Share Based Compensation Arrangement By Share Based Payment Award Expiration Term

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Share-based compensation arrangement by Share-based payment award option exercisable weighted average remaining contractual term.

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- Definition

Share based compensation arrangement by share based payment award percentage of shares available for issue.

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

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- Definition

Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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- Definition

Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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- Definition

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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- Definition

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of options outstanding.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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- Definition

The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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- Definition

Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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