Employee Benefit Plans	12 Months Ended
Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plans	18. Employee Benefit Plans Nucor makes contributions to a Profit Sharing and Retirement Savings Plan for qualified employees based on the profitability of the Company. Nucor’s expense for these benefits totaled $181.4 million in 2019 ($307.9 million in 2018 and $169.4 million in 2017). The related liability for these benefits is included in salaries, wages and related accruals in the consolidated balance sheets. Nucor also has a medical plan covering certain eligible early retirees. The unfunded obligation, included in deferred credits and other liabilities in the consolidated balance sheets, totaled $27.0 million at December 31, 2019 ($25.5 million at December 31, 2018). The expense associated with this early retiree medical plan totaled $2.0 million in 2019 ($2.1 million in 2018 and $2.2 million in 2017). The discount rate used by Nucor in determining its benefit obligation was 3.23% in 2019 (4.24% in 2018 and 3.6% in 2017). The health care cost increase trend rate used was 6.0% in 2019 (6.3% in 2018 and 6.6% in 2017). The health care cost increase trend rate is projected to decline gradually to 4.5% by 2037.

Employee Benefit Plans

12 Months Ended

Dec. 31, 2019

Compensation And Retirement Disclosure [Abstract]

18. Employee Benefit Plans

Nucor makes contributions to a Profit Sharing and Retirement Savings Plan for qualified employees based on the profitability of the Company. Nucor’s expense for these benefits totaled $181.4 million in 2019 ($307.9 million in 2018 and $169.4 million in 2017). The related liability for these benefits is included in salaries, wages and related accruals in the consolidated balance sheets.

Nucor also has a medical plan covering certain eligible early retirees. The unfunded obligation, included in deferred credits and other liabilities in the consolidated balance sheets, totaled $27.0 million at December 31, 2019 ($25.5 million at December 31, 2018). The expense associated with this early retiree medical plan totaled $2.0 million in 2019 ($2.1 million in 2018 and $2.2 million in 2017). The discount rate

used by Nucor in determining its benefit obligation was 3.23% in 2019 (4.24% in 2018 and 3.6% in 2017). The health care cost increase trend rate used was 6.0% in 2019 (6.3% in 2018 and 6.6% in 2017). The health care cost increase trend rate is projected to decline gradually to 4.5% by 2037.