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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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Amount of stock repurchase plan authorized.

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Amount remaining of a stock repurchase plan authorized.

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Number of shares that have been repurchased and retired during the period.

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Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

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Total cost of shares repurchased divided by the total number of shares repurchased.

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Shareholders' Equity (Details) - USD ($)	3 Months Ended
Shareholders' Equity (Details) - USD ($)	Mar. 26, 2019	Mar. 27, 2018	Jul. 23, 2018	Aug. 24, 2016	Aug. 23, 2016	Feb. 26, 2016
Class of Stock [Line Items]
Shares repurchased, value	$ 4,306,000	$ 34,000
Common Stock and Warrants [Member]
Class of Stock [Line Items]
Maximum authorized stock repurchase amount (up to)				$ 50,000,000	$ 25,000,000	$ 25,000,000.0
share repurchase program additional authorized amount	75,000,000		$ 25,000,000
Remaining authorized stock repurchase amount	$ 25,400,000
Common Stock
Class of Stock [Line Items]
Shares repurchased (in shares)	270,874
Average price per share	$ 10.30
Shares repurchased, value	$ 2,800,000
Warrants [Member]
Class of Stock [Line Items]
Shares repurchased (in shares)	840,255
Average price per share	$ 1.78
Shares repurchased, value	$ 1,500,000