Product warranties (Tables)

6 Months Ended

Jun. 30, 2012

Product Warranties Disclosures [Abstract]

Provision for warranty obligations

The activity related to warranty obligations is as follows:

	Three Months Ended					Six Months Ended
	June 30, 2012			July 2, 2011		June 30, 2012		July 2, 2011
Balance at beginning of period	$	32,680		36,437		30,144		37,265
Warranty claims paid during the period	(14,866		)	(17,012	)	(28,786	)	(30,747	)
Pre-existing warranty accrual adjustment during the period	—			489		—		3,484
Warranty expense during the period	17,053			12,138		33,509		22,050
Balance at end of period	$	34,867		32,052		34,867		32,052