Long-term debt (Tables)

12 Months Ended

Jan. 03, 2015

Debt Disclosure [Abstract]

Schedule Of Line Of Credit Facilities And Long Term Debt [Table Text Block]

		January 3, 2015	December 28, 2013
		$	$
Bank indebtedness:
	North American credit facilities(1)	6,263	64,382
	European credit facilities(2)	72,191	61,892
	Opta Minerals revolving term credit facility(3)	12,956	15,579
		91,410	141,853
Long-term debt:
	Opta Minerals non-revolving term credit facility(3)	34,633	42,253
	Lease obligations(4)	4,965	6,444
	Other	257	311
		39,855	49,008
	Less: current portion	5,927	6,354
		33,928	42,654

Schedule of Maturities of Long-term Debt [Table Text Block]

	$
2015	5,927
2016	5,623
2017	5,480
2018	5,414
2019	5,393
Thereafter	12,018
	39,855

Schedule Of Interest Expense And Interest Income [Table Text Block]

	January 3, 2015	December 28, 2013	December 29, 2012
	$	$	$
Interest expense	7,913	8,046	9,602
Interest income	(149)	(186)	(269)
Interest expense, net	7,764	7,860	9,333