The number of shares purchased by employees under the Investment Share Purchase Program.

No definition available.

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- Definition

Share Based Compensation Arrangement By Share Based Payment Award Options Annual Vesting Percentage

+ References

No definition available.

+ Details

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- Definition

Exercise or strike price stated in the contract for options indexed to the issuer's equity shares.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 480

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (f)(1)

-URI http://asc.fasb.org/extlink&oid=6940734&loc=d3e22047-110879

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 40

-Section 50

-Paragraph 5

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=6445032&loc=d3e90205-114008

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- Definition

The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

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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.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

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).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued 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).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

+ Details

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (d)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Number of options outstanding, including both vested and non-vested options.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

+ References

No definition available.

+ Details

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Common Stock and Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended		9 Months Ended
	May. 27, 2015	Jan. 01, 2015	Jan. 01, 2008	Sep. 26, 2015	Sep. 27, 2014	Sep. 26, 2015	Sep. 27, 2014	Dec. 27, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period exercise price						$ 283.22
Stock option outstanding				1,155,371		1,155,371		1,380,444
Other than options granted in period						14,405
Weighted average fair value of stock awards						$ 195.07
Stock-based compensation expense				$ 1,600	$ 1,400	$ 5,218	$ 5,324
Senior Management \| Common Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period		18,723
Options granted in period, weighted average fair value		$ 130.43
Non Employee Director \| Common Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period	5,640
Options granted in period, weighted average fair value	$ 122.25
Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period exercise price						$ 147.48	$ 150.19
Stock option outstanding				452,319	603,092	452,319	603,092
Chief Executive Officer \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period exercise price			$ 37.65
Chief Executive Officer \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period exercise price			$ 70
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other than options granted in period		6,092
Weighted average fair value of stock awards		$ 289.54
Restricted Stock Awards \| Vesting Scenario One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		5 years
Other than options granted in period		5,402
Restricted Stock Awards \| Vesting Scenario Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Other than options granted in period		690
Investment Share Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period						5 years
Shares employees elected to purchase		8,313
Weighted average fair value of stock awards		$ 125.84
Market Based Stock Option \| Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period			753,864
Vesting period			5 years
Vesting percentage per year			20.00%
Stock price			$ 42.00