Long-Term Debt (Details) $ in Millions	9 Months Ended
	Sep. 27, 2016 USD ($) item	Dec. 22, 2015 USD ($)
Long-term debt
Maximum commitments		$ 200.0
Maximum commitments, letter of credit subfacility		50.0
Additional available credit		$ 100.0
Available borrowings	$ 182.7
Outstanding borrowings	0.0
Outstanding letters of credit	$ 17.3
Multiplier of rent used to compute Adjusted Debt | item	8
Threshold amount of unrestricted cash and cash equivalents above which amounts are netted against debt for calculation of net adjusted leverage ratio	$ 25.0
Trailing period for which EBITDAR is computed	12 months
Net Adjusted Leverage Ratio	2.4
EBITDAR Ratio	3.1
Minimum
Long-term debt
Financial covenant, EBITDAR Ratio	1.9
Commitment fee (as a percent)	0.125%
Maximum
Long-term debt
Financial covenant, EBITDAR Ratio	4.0
Commitment fee (as a percent)	0.25%
Adjusted LIBO Rate
Long-term debt
Credit facility, floating interest rate basis	Adjusted LIBO Rate
Adjusted LIBO Rate | Minimum
Long-term debt
Credit facility, basis spread on variable rate, (as a percent)	1.00%
Adjusted LIBO Rate | Maximum
Long-term debt
Credit facility, basis spread on variable rate, (as a percent)	1.75%
Federal Funds Effective Rate
Long-term debt
Credit facility, floating interest rate basis	Federal Funds Effective Rate
Credit facility, basis spread on variable rate, (as a percent)	0.50%
One-month Adjusted LIBO Rate
Long-term debt
Credit facility, floating interest rate basis	one-month Adjusted LIBO Rate
Fixed percentage added to variable rate	1.00%
One-month Adjusted LIBO Rate | Minimum
Long-term debt
Credit facility, basis spread on variable rate, (as a percent)	0.00%
One-month Adjusted LIBO Rate | Maximum
Long-term debt
Credit facility, basis spread on variable rate, (as a percent)	0.75%