Commitments and Contingencies Warranty Liabilities (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013
Commitments and Contingencies Disclosure [Abstract]
Limited warranty period (in years)	25 years
Customer participation term (in years)	23 years
Warranty Liabilities [Roll Forward]
Balance at beginning of year	$ 4,153	$ 4,858
Additions charged to costs and expenses for current-year sales	6,119	3,206
Deductions from reserves	(5,434)	(4,428)
Changes in liability for pre-existing warranties during the current year, including expirations	268	3
Acquired warranty reserve(1)	0	532	[1]
Balance at end of period	$ 5,106	$ 4,171

[1] Acquired warranty reserve resulted from the acquisition of Comfortaire Corporation in the first quarter of fiscal 2013.