Debt and Other Financing Arrangements - Schedule of Debt and Other Financing Arrangements (Parenthetical) (Detail) - USD ($)				12 Months Ended
	May 23, 2022	Mar. 11, 2022	Feb. 01, 2022	Dec. 31, 2024	Dec. 31, 2023
CSI [Member]
Debt Instrument [Line Items]
Acquired controlling ownership percentage			51.00%
Due from 2025 to 2061 [Member] | Industrial Revenue Bonds [Member]
Debt Instrument [Line Items]
Debt instrument - maturity year - start				2025
Debt instrument - maturity year - end				2061
Principal amount of notes				$ 1,350,000,000	$ 1,350,000,000
Due from 2025 to 2061 [Member] | Industrial Revenue Bonds [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument interest rate				3.92%	4.20%
Due from 2025 to 2061 [Member] | Industrial Revenue Bonds [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument interest rate				4.70%	5.10%
NJSM notes due from 2025 to 2029 [Member] | NUE NJSM Notes [Member]
Debt Instrument [Line Items]
Debt instrument - maturity year - start				2025
Debt instrument - maturity year - end				2029
Line of credit facility maximum borrowing capacity				$ 80,000,000
Principal amount of notes				$ 80,000,000	$ 80,000,000
NJSM notes due from 2025 to 2029 [Member] | NUE NJSM Notes [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument interest rate				5.46%
NJSM notes due from 2025 to 2029 [Member] | NUE NJSM Notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument interest rate				6.88%
Notes, 2.000%, due 2025 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate				2.00%
Debt instrument - maturity year				2025
Principal amount of notes				$ 500,000,000	500,000,000
Notes, 3.950%, due 2025 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	3.95%			3.95%
Debt instrument - maturity year	2025			2025
Principal amount of notes	$ 500,000,000			$ 500,000,000	500,000,000
Notes, 4.300%, due 2027 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	4.30%			4.30%
Debt instrument - maturity year	2027			2027
Principal amount of notes	$ 500,000,000			$ 500,000,000	500,000,000
Term Notes, 2.950%, due 2027 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate				2.95%
Debt instrument - maturity year				2027
Principal amount of notes				$ 48,000,000	58,000,000
Term Notes, 2.950%, due 2027 [Member] | CSI [Member]
Debt Instrument [Line Items]
Debt instrument interest rate			2.95%
Acquired controlling ownership percentage			51.00%
Principal amount of notes			$ 101,000,000
Payments due quarterly			$ 3,000,000
Maturity period			Mar. 31, 2027
Notes, 3.950%, due 2028 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate				3.95%
Debt instrument - maturity year				2028
Principal amount of notes				$ 500,000,000	500,000,000
Notes, 2.700%, due 2030 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate				2.70%
Debt instrument - maturity year				2030
Principal amount of notes				$ 500,000,000	500,000,000
Notes, 3.125%, due 2032 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate		3.125%		3.125%
Debt instrument - maturity year		2032		2032
Principal amount of notes		$ 550,000,000		$ 550,000,000	550,000,000
Notes, 6.400%, due 2037 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate				6.40%
Debt instrument - maturity year				2037
Principal amount of notes				$ 543,000,000	543,000,000
Notes, 5.200%, due 2043 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate				5.20%
Debt instrument - maturity year				2043
Principal amount of notes				$ 338,000,000	338,000,000
Notes, 4.400%, due 2048 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate				4.40%
Debt instrument - maturity year				2048
Principal amount of notes				$ 329,000,000	329,000,000
Notes, 3.850%, due 2052 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate		3.85%		3.85%
Debt instrument - maturity year		2052		2052
Principal amount of notes		$ 550,000,000		$ 550,000,000	550,000,000
Notes, 2.979%, due 2055 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate				2.979%
Debt instrument - maturity year				2055
Principal amount of notes				$ 439,000,000	$ 439,000,000