Number of equity plans.

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Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Converted into Common Stock

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No definition available.

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Share-based Compensation Arrangement by Share-based Payment Award, Period of Average Closing Trading Price Ending on Last Day of Performance Period

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Share-based Compensation Arrangement by Share-based Payment Award, Period of Average Closing Trading Price Preceding First Day of Performance Period

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Target Performance Rate

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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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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Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

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No definition available.

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Unrecognized cost of unvested options awarded to employees as compensation.

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Amount of cash outflow to satisfy an employee's income tax withholding obligation as part of a net-share settlement of a share-based award.

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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, 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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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).

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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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.

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No definition available.

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The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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The highest quantity of shares an employee can purchase under the plan per period.

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

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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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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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No definition available.

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Percentage of vesting of share-based compensation awards.

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Purchase price of common stock expressed as a percentage of its fair value.

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No definition available.

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- Definition

The number of shares issued during the period upon the conversion of units. An example of a convertible unit is an umbrella partnership real estate investment trust unit (UPREIT unit).

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Number of shares issued during the period as a result of an employee stock purchase plan.

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Number of share options (or share units) exercised during the current period.

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Stockholders' Equity - Textual (Details) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 24, 2016 USD ($) Plan $ / shares shares	Sep. 24, 2016 USD ($) Plan $ / shares shares	Sep. 26, 2015 USD ($) shares	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity incentive plans \| Plan	2	2
Stock options granted (in shares)	380,000	380,000
Weighted-average grant date fair value (in dollars per share) \| $ / shares	$ 3.29	$ 3.29
Stock options exercised (in shares)	0	2,312
Weighted-average exercise price per share, stock options (in dollars per share) \| $ / shares		$ 5.85
Unrecognized stock-based compensation expense, stock options \| $	$ 3,100	$ 3,100
Weighted-average amortization period		2 years 6 months 26 days
Taxes paid for awards vested under equity incentive plans \| $		$ 1,787	$ 2,093
Stock-based compensation \| $	$ 1,700
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average amortization period		2 years 7 months 6 days
Awards granted (in shares)	102,200	1,094,513
Weighted-average grant date fair value per share (in dollars per share) \| $ / shares	$ 7.84	$ 7.01
Awards vested (in shares)	58,444	546,534
Taxes paid for awards vested under equity incentive plans \| $	$ 200	$ 1,700
Unrecognized stock-based compensation expense \| $	14,600	$ 14,600
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average amortization period		1 month
Unrecognized stock-based compensation expense \| $	$ 200	$ 200
ESPP, maximum employee payroll deduction percentage	15.00%	15.00%
ESPP, maximum number of shares per employee (in shares)		2,000
ESPP, discounted purchase price percentage		85.00%
Shares available for issuance under the ESPP (in shares)	635,913	635,913
Shares issued under the ESPP (in shares)	493,226		493,226
Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average amortization period		1 year 1 month 14 days
Awards granted (in shares)	0	550,000
Weighted-average grant date fair value per share (in dollars per share) \| $ / shares		$ 7.42
Taxes paid for awards vested under equity incentive plans \| $		$ 100
Unrecognized stock-based compensation expense \| $	$ 2,200	$ 2,200
Period of average closing trading price ending on the last day of applicable performance period						90 days
Period of average closing trading price preceding first day of performance period						90 days
Shares converted into common stock (in shares)		44,992
Performance Restricted Stock Units \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period		1 year		2 years	2 years	2 years
Target performance rate		0.00%
Performance Restricted Stock Units \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period		2 years		3 years	3 years	3 years
Target performance rate		200.00%
Common Stock \| Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of stock issued upon conversion of units (in shares)		26,557
Period one - February 2017 \| Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		50.00%
Period two - February 2018 \| Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25.00%
Period three - February 2019 \| Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25.00%