Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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+ Details

Supplemental cash flow information (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 28, 2013	Jun. 29, 2013	Dec. 29, 2012	Sep. 29, 2012	Jun. 30, 2012	Dec. 31, 2011
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 6,819	$ 6,460	$ 6,840	$ 4,187	$ 3,247	$ 2,378
Opta Minerals Inc [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 3,226		$ 3,966