Business and Summary of Significant Accounting Policies Warranty Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of year	$ 8,633	$ 10,028	$ 5,824
Additions charged to costs and expenses for current-year sales	12,214	9,034	9,368
Deductions from reserves	(10,752)	(10,016)	(6,486)
Changes in liability for pre-existing warranties during the current year, including expirations	(775)	(413)	1,322
Balance at end of period	$ 9,320	$ 8,633	$ 10,028