Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Sep. 29, 2012	Dec. 31, 2011
Disclosure Accrued Expenses [Abstract]
Advanced customer deposits	$ 38,056	$ 41,434
Accrued payroll and related expenses	18,760	23,136
Accrued warranty	16,586	13,842
Accrued customer rebates	12,525	10,771
Accrued agent commission	10,029	8,668
Accrued professional services	7,496	7,497
Other accrued expenses	17,327	31,798
Accrued expenses	$ 155,862	$ 170,392