Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
Dec. 31, 2020
Accounting Policies [Abstract]
Cash equivalents original maturity period	three months or less

The maturity period for an instrument to be considered a cash equivalent.

No definition available.

Name:	nue_CashEquivalentMaturityPeriod
Namespace Prefix:	nue_
Data Type:	us-types:durationStringItemType
Balance Type:	na
Period Type:	duration