Accounts payable and accrued expenses (Details) - USD ($) $ in Thousands	Mar. 30, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Outstanding checks in excess of cash	$ 3,626	$ 14,624
Accounts payable, trade	914,205	811,879
Accrued expenses	407,386	430,431
Product warranties	46,129	47,511
Accrued interest	7,197	21,908
Accrued compensation and benefits	192,730	197,513
Total accounts payable and accrued expenses	$ 1,571,273	$ 1,523,866