| Component: (Network and Table) | |
|---|---|
| Network | 4040 - Disclosure - INVENTORIES (Details) (http://www.valmont.com/role/DisclosureInventoriesDetails)  | 
| Table | (Implied) | 
| Reporting Entity [Axis] | 0000102729 (http://www.sec.gov/CIK) | 
| INVENTORIES | Period [Axis] | |
|---|---|---|
2013-12-28  | 2012-12-29  | |
INVENTORIES  | ||
Raw materials and purchased parts  | ||
Work-in-process  | ||
Finished goods and manufactured goods  | ||
Subtotal  | ||
Less: LIFO reserve  | ||
Net inventory  | 380,000,000    | 412,384,000    | 
Increase in operating income due to liquidating portion of LIFO inventories  | ||