Accounts payable and accrued expenses (Components of accounts payable and accrued expenses) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2014	Dec. 31, 2013
Payables and Accruals [Abstract]
Outstanding checks in excess of cash	$ 20,950	$ 18,012
Accounts payable, trade	711,807	631,732
Accrued expenses	262,401	273,230
Product warranties	32,235	35,818
Accrued interest	35,455	35,618
Deferred tax liability	12,838	1,095
Income taxes payable	11,710	11,235
Accrued compensation and benefits	165,895	186,853
Total accounts payable and accrued expenses	$ 1,253,291	$ 1,193,593