Summary of Business and Significant Accounting Policies Matching Contributions (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 24, 2016	Jun. 26, 2015	Jun. 24, 2016	Jun. 26, 2015
Retirement and Tax-Deferred Savings Plan
Employer matching contributions (as a percent)			58.33%
Elective deferrals (as a percent)			6.00%
Maximum employer match to the 401(k) Plan (as a percent)			6.00%
Expenses related to matching contributions and defined contributions made in common stock for the 401(k) Plan	$ 7.4	$ 5.5	$ 12.9	$ 12.4