Accounts payable and accrued expenses (Components of accounts payable and accrued expenses) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 30, 2013	Dec. 31, 2012
Payables and Accruals [Abstract]
Outstanding checks in excess of cash	$ 17,411	$ 25,480
Accounts payable, trade	459,397	387,871
Accrued expenses	176,045	180,039
Product warranties	35,483	32,930
Accrued interest	16,553	26,843
Deferred tax liability	10,377	6,309
Income taxes payable	10,033	2,074
Accrued compensation and benefits	98,836	111,890
Total accounts payable and accrued expenses	$ 824,135	$ 773,436