Derivative financial instruments and fair value measurements (Notional Amounts) (Details)	Apr. 05, 2014 lots
Cocoa [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	60
Future And Forward Purchase Contracts [Member] | Corn [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	1,778,000
Future And Forward Purchase Contracts [Member] | Soybean [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	1,814,000
Future And Forward Sale Contracts [Member] | Corn [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(789,000)
Future And Forward Sale Contracts [Member] | Soybean [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(2,138,000)
Future [Member] | Corn [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(1,355,000)
Future [Member] | Soybean [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(265,000)