Nature of Business and Summary of Significant Accounting Policies (Details) - Valuation Assumptions	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Employee Stock Option
Note 1 - Nature of Business and Summary of Significant Accounting Policies (Details) - Valuation Assumptions of Stock Options [Line Items]
Expected dividend yield	0.00%	0.00%	0.00%
Expected stock price volatility	34.10%	34.30%	35.70%
Risk-free interest rate	1.40%	1.40%	1.70%
Expected life of options	4 years 8 months	5 years	5 years
Employee Stock Purchase Plan
Note 1 - Nature of Business and Summary of Significant Accounting Policies (Details) - Valuation Assumptions of Stock Options [Line Items]
Expected dividend yield	0.00%	0.00%	0.00%
Risk-free interest rate	0.50%	0.23%	0.05%
Expected life of options	6 months	6 months	6 months
Employee Stock Purchase Plan | Minimum
Note 1 - Nature of Business and Summary of Significant Accounting Policies (Details) - Valuation Assumptions of Stock Options [Line Items]
Expected stock price volatility	29.30%	31.10%	45.50%
Employee Stock Purchase Plan | Maximum
Note 1 - Nature of Business and Summary of Significant Accounting Policies (Details) - Valuation Assumptions of Stock Options [Line Items]
Expected stock price volatility	35.30%	37.90%	45.90%