Inventories - Additional Information (Detail)	Jun. 30, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials and supplies in inventory, percentage	42.00%	42.00%
Finished and semi-finished products in inventory, percentage	58.00%	58.00%

Finished and semi-finished products in inventory, percentage.

No definition available.

Name:	nue_FinishedAndSemiFinishedProductsInInventoryPercentage
Namespace Prefix:	nue_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant