Impairment Of Long-Lived Assets And Other Lease Charges Closed Restaurant Reserve Activity (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Apr. 01, 2018	Dec. 31, 2017
Restructuring Reserve [Roll Forward]
Closed-restaurant reserve, beginning of the period	$ 2,028	$ 1,513
Provisions for restaurant closures	87	1,174
Changes in estimates of accrued costs	(4)	81
Payments, net	(166)	(862)
Other adjustments, including the effect of discounting future obligations	33	122
Closed-restaurant reserve, end of the period	$ 1,978	$ 2,028

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

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Discloses the amount charged against the accrued restructuring reserves, or earnings if not previously accrued, during the period for the specified type of restructuring cost.

+ References

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-Publisher FASB
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- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Amount of expense (reversal of expense) which increases (decreases) the restructuring reserve from an adjustment to a previously accrued restructuring liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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Amount of increase (decrease) in the restructuring reserve related to foreign currency translation (gain) loss and other increases (decreases).

+ References

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