Bank indebtedness and Long-Term Debt (Bank indebtedness Table) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 29, 2012	Dec. 31, 2011
Line of Credit Facility [Line Items]
Line of Credit Facility, Amount Outstanding	$ 111,237	$ 109,718
Opta Minerals Inc [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Amount Outstanding	7,057	0
The Organic Corporation [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Amount Outstanding	65,353	50,310
Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Amount Outstanding	802
Cad Line Of Credit [Member] | Opta Minerals Inc [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Amount Outstanding	0	7,765
Cad Line Of Credit [Member] | Syndicate Lending Group [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Amount Outstanding	0	26
U S Line Of Credit [Member] | Syndicate Lending Group [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Amount Outstanding	$ 38,025	$ 51,617