Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 27, 2018	Jun. 28, 2017	Jun. 27, 2018	Jun. 28, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, options outstanding (shares)	2,196,744		2,196,744
Common stock, options vested (shares)			1,980,301
Common stock, options unvested (shares)	216,443		216,443
Stock options exercised (shares)	0	17,661	0	17,661
Number of options granted at fair market value (shares)	120,752	128,252	120,752
Stock-based compensation	$ 600	$ 0	$ 1,170	$ 414
Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost	$ 300		$ 800
Premium Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, options outstanding (shares)	1,599,944		1,599,944
Employee Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense	$ 700		$ 700
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			3 years 3 months 29 days
Share-based Compensation Arrangement by Share-based Payment Award, Accelerated Vesting, Number			33,545
Restricted Stock
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	0	169,676	0	169,676
Unvested restricted shares outstanding (shares)	113,741		113,741
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options	$ 1,400		$ 1,400
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			2 years 8 months 6 days
Performance Shares [Member]
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	0	72,116,000	0
Unvested restricted shares outstanding (shares)	72,116		72,116
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options	$ 400		$ 400
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			4 years 10 months 14 days
Restricted Stock Units (RSUs) [Member]
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	96,156	0	96,156,000	0
Unvested restricted shares outstanding (shares)	96,156		96,156
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options	$ 900		$ 900
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			3 years 10 months 14 days

Unrecognized cost of unvested share-based compensation awards.

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- Definition

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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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.

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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.

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

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

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

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

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

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Number of non-vested options outstanding.

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Number of options vested.

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

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