SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 3) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2014	Dec. 28, 2013
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets and liabilities measured at fair value
Trading Securities	$ 45,966	$ 41,043
Carrying Value
Assets and liabilities measured at fair value
Trading Securities	45,966	41,043
Delta EMD Pty. Ltd.
Assets and liabilities measured at fair value
Fair value of remaining ownership	10,114	13,910
Valmont Deferred Compensation Plan
Assets and liabilities measured at fair value
Assets recorded for the investments held	35,852	27,133
Liabilities recorded for the investments held	$ 35,852	$ 27,133