Commitments and Contingencies Warranty Liabilities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013
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	$ 4,153	$ 4,858
Additions charged to costs and expenses for current-year sales	1,568	1,469
Deductions from reserves	(1,536)	(1,403)
Changes in liability for pre-existing warranties during the current year, including expirations	153	(306)
Acquired warranty reserve(1)	0	658	[1]
Balance at end of period	$ 4,338	$ 5,276

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