Derivative financial instruments and fair value measurements (Tables)

9 Months Ended

Sep. 29, 2012

Derivative Instruments And Hedging Activities Disclosure [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

			September 29, 2012
			Fair value
			asset (liability)	Level 1	Level 2	Level 3
			$	$	$	$
(a)	Commodity futures and forward contracts(1)
		Unrealized short-term derivative gain	5,382	-	5,382	-
		Unrealized long-term derivative gain	262	-	262	-
		Unrealized short-term derivative loss	(3,540)	(891)	(2,649)	-
		Unrealized long-term derivative loss	(10)	-	(10)	-
(b)	Inventories carried at market(2)		18,625	-	18,625	-
(c)	Interest rate swaps(3)		(497)	-	(497)	-
(d)	Forward foreign currency contracts(4)		304	-	304	-
(e)	Contingent consideration(5)		(4,487)	-	-	(4,487)
			December 31, 2011
			Fair value
			asset (liability)	Level 1	Level 2	Level 3
			$	$	$	$
(a)	Commodity futures and forward contracts(1)
		Unrealized short-term derivative gain	2,125	34	2,091	-
		Unrealized long-term derivative gain	271	-	271	-
		Unrealized short-term derivative loss	(1,410)	-	(1,410)	-
		Unrealized long-term derivative loss	(70)	-	(70)	-
(b)	Inventories carried at market(2)		12,685	-	12,685	-
(c)	Interest rate swaps(3)		(256)	-	(256)	-
(d)	Forward foreign currency contracts(4)		(149)	-	(149)	-
(e)	Contingent consideration(5)		(4,456)	-	-	(4,456)

Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]

	Number of bushels
	purchase (sale)
	Corn	Soybeans
Forward commodity purchase contracts	1,515	698
Forward commodity sale contracts	(807)	(662)
Commodity futures contracts	(1,292)	(673)