Retirement Benefit Plans Executive Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 01, 2017	Dec. 30, 2018	Dec. 31, 2017
Other liabilities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Deferred Compensation Arrangements, Recorded Liability		$ 444	$ 259
Chief Executive Officer
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Deferred Compensation Arrangement with Individual, Base Salary	$ 1,000
Supplemental Employee Retirement Plans, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Liability, Defined Benefit Plan		$ 1,257	$ 2,476