Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Unrecognized cost of unvested options awarded to employees as compensation.

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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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&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.

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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

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

+ References

+ Details

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- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The estimated measure of the minimum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

No definition available.

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- Definition

The maximum risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

No definition available.

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- Definition

The minimum risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

No definition available.

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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

Net number of non-option equity instruments granted to participants.

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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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 accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

+ Details

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- Definition

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

+ References

No definition available.

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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.

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- Definition

Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

+ References

+ Details

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-Paragraph 2
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- Definition

An excess of the fair value of the modified award over the fair value of the award immediately before the modification.

+ References

+ Details

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- Definition

Number of shares for which recognition of compensation cost was accelerated.

+ References

No definition available.

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- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

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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.

+ References

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- Definition

Number of non-vested options outstanding.

+ References

No definition available.

+ Details

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- Definition

Number of options vested.

+ References

No definition available.

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- Definition

The noncash expense that accounts for the value of stock or unit options distributed to employees as compensation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

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Stock-Based Compensation - Additional Information (Details) - USD ($)				12 Months Ended
	Dec. 27, 2017	Dec. 28, 2016	Nov. 15, 2016	Dec. 26, 2018	Dec. 27, 2017	Dec. 28, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, options outstanding (shares)	2,309,103	2,191,728		2,102,404	2,309,103	2,191,728
Common stock, options vested (shares)				1,722,455
Common stock, options unvested (shares)				379,949
Options to purchase common stock granted (shares)				311,272	135,036
Stock-based compensation expense				$ 2,005,000	$ 1,056,000	$ 1,063,000
Aggregate intrinsic value of options outstanding				15,500,000
Aggregate intrinsic value of options exercisable	$ 14,200,000				14,200,000
Intrinsic value of options exercised				1,500,000	200,000	900,000
Stock-based compensation expense				1,100,000	$ 600,000	900,000
Incremental expense from plan modification				800,000
Unrecognized compensation expense				$ 1,300,000
Unrecognized compensation expense, recognition period				3 years 3 months 7 days
Granted (shares)				395,880	181,292
Exercise price equal to the fair market value of the common stock on the date of grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options to purchase common stock granted (shares)				311,272	135,036
Option vesting period				4 years
Premium Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, options outstanding (shares)				1,381,010
Performance Based Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, options outstanding (shares)				0
Common stock, options vested (shares)	17,378	80,799	17,380
Stock-based compensation expense						600,000
Time Based Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, options outstanding (shares)				2,102,404
Options expiration period				10 years
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized number of common stock for issuance (shares)				5,652,240
Number of share available for grant (shares)				1,495,767
Expected dividend yield				0.00%	0.00%
Weighted average grant date fair value (usd per share)				$ 3.78	$ 4.29
Expected volatility				28.40%
Expected life				6 years 3 months	5 years 9 months
Risk-free interest rates, minimum				2.86%	1.88%
Risk-free interest rates, maximum				2.88%	2.01%
Expected volatility, minimum					28.60%
Accelerated vesting of awards (shares)				33,545
Restricted Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense				$ 1,000,000	$ 500,000	$ 200,000
Unrecognized compensation expense, recognition period				3 years 21 days
Granted (shares)				323,764
Unrecognized compensation expense				$ 4,600,000
Restricted Shares \| Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period				3 years
Restricted Shares \| Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period				4 years
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				72,116
Performance Shares \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period				1 year
Performance Shares \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period				5 years