Inventories	3 Months Ended
Apr. 04, 2020
Inventory Disclosure [Abstract]
Inventories	2. Inventories Inventories consisted of approximately 42% raw materials and supplies and 58% finished and semi-finished products at both April 4, 2020 and December 31, 2019. Nucor’s manufacturing process consists of a continuous, vertically integrated process from which products are sold to customers at various stages throughout the process. Since most steel products can be classified as either finished or semi-finished products, these two categories of inventory are combined.

The entire disclosure for inventory. Includes, but is not limited to, the basis of stating inventory, the method of determining inventory cost, the classes of inventory, and the nature of the cost elements included in inventory.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-URI http://asc.fasb.org/topic&trid=2126998

Name:	us-gaap_InventoryDisclosureTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration