Stockholders' Equity - Additional Information (Detail) - USD ($)	Mar. 31, 2018	Sep. 02, 2015
Nucor-Yamato Steel Company [Member]
Stockholders' Equity [Line Items]
Noncontrolling interest, ownership percentage by parent	51.00%
Common Stock [Member]
Stockholders' Equity [Line Items]
Share repurchase program remaining amount	$ 708,900,000
Common Stock [Member] | Maximum [Member]
Stockholders' Equity [Line Items]
Share repurchase program authorized amount		$ 900,000,000