Commitments and Contingencies Warranty Liabilities (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012
Warranty Liabilities [Abstract]
Limited warranty period (in years)	25 years
Customer participation term (in years)	23 years
Warranty Liabilities [Roll Forward]
Balance at beginning of year	$ 4,858	$ 6,310
Additions charged to costs and expenses for current-year sales	3,206	3,023
Deductions from reserves	(4,428)	(3,785)
Changes in liability for pre-existing warranties during the current year, including expirations	3	(484)
Acquired warranty reserve	532	0
Balance at end of period	$ 4,171	$ 5,064