Nucor (NUE) 10-Q 6 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 28, 2019shares
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 28, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Trading Symbol	NUE
Entity Registrant Name	NUCOR CORP
Entity Central Index Key	0000073309
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common stock, par value $0.40 per share
Security Exchange Name	NYSE
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	1-4119
Entity Tax Identification Number	13-1860817
Entity Address, Address Line One	1915 Rexford Road
Entity Address, City or Town	Charlotte
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	28211
City Area Code	704
Local Phone Number	366-7000
Entity Common Stock, Shares Outstanding	303,215,267

Condensed Consolidated Statemen

Condensed Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Income Statement [Abstract]
Net sales	$ 5,464,502	$ 6,742,202	$ 17,457,112	$ 18,771,395
Costs, expenses and other:
Cost of products sold	4,891,991	5,452,052	15,213,215	15,588,249
Marketing, administrative and other expenses	159,301	234,081	549,020	651,422
Equity in losses (earnings) of unconsolidated affiliates	1,585	(13,634)	(2,459)	(34,157)
Impairment of assets		110,000		110,000
Interest expense, net	31,286	37,201	92,759	103,766
Costs, expenses and other, total	5,084,163	5,819,700	15,852,535	16,419,280
Earnings before income taxes and noncontrolling interests	380,339	922,502	1,604,577	2,352,115
Provision for income taxes	86,752	216,215	367,920	552,101
Net earnings	293,587	706,287	1,236,657	1,800,014
Earnings attributable to noncontrolling interests	18,556	29,631	73,337	86,026
Net earnings attributable to Nucor stockholders	$ 275,031	$ 676,656	$ 1,163,320	$ 1,713,988
Net earnings per share:
Basic	$ 0.90	$ 2.13	$ 3.79	$ 5.37
Diluted	$ 0.90	$ 2.13	$ 3.78	$ 5.35
Average shares outstanding:
Basic	304,637	315,913	305,553	317,928
Diluted	304,980	316,798	306,029	318,882

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 28, 2019		Sep. 29, 2018		Sep. 28, 2019		Sep. 29, 2018
Statement Of Comprehensive Income [Abstract]
Net earnings	$ 293,587		$ 706,287		$ 1,236,657		$ 1,800,014
Other comprehensive income:
Net unrealized loss on hedging derivatives, net of income taxes of $(1,000) and $(400) for the third quarter of 2019 and 2018, respectively, and $(2,500) and $(1,000) for the first nine months of 2019 and 2018, respectively	(3,315)		(1,393)		(7,801)		(5,792)
Reclassification adjustment for settlement of hedging derivatives included in net income, net of income taxes of $500 and $100 for the third quarter of 2019 and 2018, respectively, and $500 and $200 for the first nine months of 2019 and 2018, respectively	1,615	[1]	193	[2]	1,501	[1]	592	[2]
Foreign currency translation (loss) gain, net of income taxes of $0 for the third quarter and first nine months of 2019 and 2018	(14,306)		22,625		(5,219)		(14,726)
Net current-period other comprehensive income (loss)	(16,006)		21,425		(11,519)		(19,926)
Comprehensive income	277,581		727,712		1,225,138		1,780,088
Comprehensive income attributable to noncontrolling interests	(18,556)		(29,631)		(73,337)		(86,026)
Comprehensive income attributable to Nucor stockholders	$ 259,025		$ 698,081		$ 1,151,801		$ 1,694,062
[1]	Includes $1,615 and $1,501 of accumulated other comprehensive income (loss) reclassifications into cost of products sold for net losses on commodity contracts in the third quarter and first nine months of 2019 2019
[2]	Includes $ 193 and $ 592 of accumulated other comprehensive income (loss) reclassifications into cost of products sold for net losses on commodity contracts in the third quarter and first nine months of 2018 , respectively. The tax impact of those reclassifications w as $ 100 and $ 200 in the third quarter and first nine months of 2018 , respectively .

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Statement Of Comprehensive Income [Abstract]
Net unrealized loss on hedging derivatives, tax	$ (1,000)	$ (400)	$ (2,500)	$ (1,000)
Reclassification adjustment for (gain) loss on settlement of hedging derivatives included in net earnings, tax effect	500	100	500	200
Foreign currency translation (loss) gain tax	$ 0	$ 0	$ 0	$ 0

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 28, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 1,686,365	$ 1,398,886
Short-term investments	249,616
Accounts receivable, net	2,312,366	2,505,568
Inventories, net	4,072,464	4,553,500
Other current assets	363,477	178,311
Total current assets	8,684,288	8,636,265
Property, plant and equipment, net	5,886,730	5,334,748
Goodwill	2,186,499	2,184,336
Other intangible assets, net	764,267	828,504
Other assets	984,481	936,735
Total assets	18,506,265	17,920,588
Current liabilities:
Short-term debt	47,725	57,870
Current portion of long-term debt and finance lease obligations	28,878
Accounts payable	1,310,670	1,428,191
Salaries, wages and related accruals	539,360	709,397
Accrued expenses and other current liabilities	659,360	610,842
Total current liabilities	2,585,993	2,806,300
Long-term debt and finance lease obligations due after one year	4,287,597	4,233,276
Deferred credits and other liabilities	771,642	679,044
Total liabilities	7,645,232	7,718,620
Nucor stockholders' equity:
Common stock	152,061	152,061
Additional paid-in capital	2,108,948	2,073,715
Retained earnings	11,130,172	10,337,445
Accumulated other comprehensive loss, net of income taxes	(313,766)	(304,133)
Treasury stock	(2,628,368)	(2,467,010)
Total Nucor stockholders' equity	10,449,047	9,792,078
Noncontrolling interests	411,986	409,890
Total equity	10,861,033	10,201,968
Total liabilities and equity	$ 18,506,265	$ 17,920,588

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018
Operating activities:
Net earnings	$ 1,236,657	$ 1,800,014
Adjustments:
Depreciation	477,957	474,330
Amortization	64,655	66,684
Stock-based compensation	74,311	65,597
Deferred income taxes	76,737	54,162
Distributions from affiliates	27,405	29,325
Equity in earnings of unconsolidated affiliates	(2,459)	(34,157)
Impairment of assets		110,000
Changes in assets and liabilities (exclusive of acquisitions and dispositions):
Accounts receivable	197,783	(615,118)
Inventories	476,761	(644,865)
Accounts payable	(180,397)	229,552
Federal income taxes	(177,405)	168,639
Salaries, wages and related accruals	(157,317)	173,732
Other operating activities	5,526	23,564
Cash provided by operating activities	2,120,214	1,901,459
Investing activities:
Capital expenditures	(984,646)	(624,739)
Investment in and advances to affiliates	(27,613)	(111,540)
Divestiture of affiliates	67,591
Disposition of plant and equipment	32,922	27,964
Acquisitions (net of cash acquired)	(9,495)
Purchase of investments	(249,616)
Proceeds from the sale of investments		50,000
Other investing activities	2,176	25,347
Cash used in investing activities	(1,168,681)	(632,968)
Financing activities:
Net change in short-term debt	(10,145)	(5)
Proceeds from long-term debt, net of discount		995,710
Repayment of long-term debt		(500,000)
Bond issuance related costs		(7,625)
Issuance of common stock	5,892	24,102
Payment of tax withholdings on certain stock-based compensation	(15,723)	(22,123)
Distributions to noncontrolling interests	(71,241)	(49,494)
Cash dividends	(369,270)	(364,982)
Acquisition of treasury stock	(197,511)	(351,392)
Other financing activities	(6,538)	(5,248)
Cash used in financing activities	(664,536)	(281,057)
Effect of exchange rate changes on cash	482	(4,383)
Increase in cash and cash equivalents	287,479	983,051
Cash and cash equivalents - beginning of year	1,398,886	949,104
Cash and cash equivalents - end of nine months	1,686,365	1,932,155
Non-cash investing activity:
Change in accrued plant and equipment purchases	$ 62,700	$ 40,996

Basis of Interim Presentation

Basis of Interim Presentation	9 Months Ended
	Sep. 28, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Interim Presentation	1. Recently Adopted Accounting Pronouncements – In the first quarter of 2019, Nucor adopted new guidance related to lease accounting using the modified retrospective approach, which permits companies to recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption without adjusting the comparative periods prior to adoption. The new lease guidance requires all lessees to recognize on the balance sheet right-of-use assets and lease liabilities for the rights and obligations created by lease arrangements with terms greater than 12 months, including operating leases. Expenses are recognized in the statement of earnings in a manner similar to previous accounting guidance. We elected the package of practical expedients permitted under the transition guidance within the new lease standard, which, among other things, allowed us to carry forward the historical lease classification. We also elected the practical expedient related to land easements, allowing us to carry forward our accounting treatment for land easements on existing agreements, and the short-term lease exemption policy such that the new lease guidance was applied to leases greater than one year in duration. The adoption of the new lease standard did not have a material impact on our consolidated financial statements as it resulted in an increase of 0.5% and 1.2% to our total assets and total liabilities, respectively, on our consolidated balance sheet at January 1, 2019. The new lease standard did not materially impact our consolidated net earnings and had no impact on our cash flows. Finance lease right-of-use assets and liabilities are presented separately from operating lease right-of-use assets and liabilities in the condensed consolidated balance sheet in accordance with the new lease standard. See Note 4 for further information. In the first quarter of 2019, we also adopted new accounting guidance related to tax effects of the Tax Cuts and Jobs Act of 2017. As a result of the adoption of the new guidance, we elected to reclassify stranded tax effects from accumulated other comprehensive income to retained earnings, effective January 1, 2019. The adoption of this new guidance did not have a material impact on the Company’s consolidated financial statements.

Inventories

Inventories	9 Months Ended
	Sep. 28, 2019
Inventory Disclosure [Abstract]
Inventories	2.

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 28, 2019
Property Plant And Equipment [Abstract]
Property, Plant and Equipment	3. Nucor performed an impairment assessment of its proved producing natural gas well assets in September 2018. One of the main assumptions that most significantly affects the undiscounted cash flows determination is management’s estimate of future pricing of natural gas and natural gas liquids. The pricing used in the impairment assessment was developed by management based on projected natural gas market supply and demand dynamics, in conjunction with a review of projections by market analysts. Management also makes key estimates on the expected reserve levels and on the expected drilling production costs. The impairment assessment was performed on each of Nucor’s three groups (“fields”) of wells, with each field defined by common geographic location. As a result of the impairment assessment, Nucor recorded an impairment charge of $110.0 million relating to two fields of wells in the third quarter of 2018. The post-impairment combined carrying value of these two fields was $68.0 million at September 28, 2019 ($71.0 million at December 31, 2018). The third field was not impaired and had a carrying value of $48.3 million at September 28, 2019 ($51.8 million at December 31, 2018). Changes in the natural gas industry or a prolonged low price environment beyond what had already been assumed in the assessment could cause management to revise the natural gas and natural gas liquids price assumptions, the estimated reserves or the estimated drilling production costs. Unfavorable revisions to these assumptions or estimates could possibly result in an impairment of some or all of the fields of proved well assets.

Leases

Leases	9 Months Ended
	Sep. 28, 2019
Disclosure Of Leases [Abstract]
Leases	4. Most leases include one or more options to renew, with renewal terms that can extend the lease term from one to five years or more. The exercise of lease renewal options is at our sole discretion and we consider these options in determining the lease term used to establish our right-of-use assets and lease liabilities. Certain leases also include options to purchase the leased property. The depreciable life of assets and leasehold improvements is limited by the expected lease term, unless there is a transfer of title or a purchase option reasonably certain of exercise. We determine that a contract contains a lease if the contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. In evaluating whether we have the right to control the use of an identified asset, we assess whether or not we have the right to direct the use of the identified asset and to obtain substantially all of the economic benefit from the use of the identified asset. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. Certain of our lease agreements include payments that adjust periodically for consumption of goods provided by the right-of-use asset in excess of contractually determined minimum amounts and for inflation. These variable lease payments are not significant. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants. Supplemental statement of earnings information related to our leases is as follows (in thousands): Three Months Nine Months (13 Weeks) Ended (39 Weeks) Ended Statement of Earnings Classification Sept. 28, 2019 Sept. 28, 2019 Operating lease cost Cost of products sold $ 4,932 $ 16,075 Operating lease cost Marketing, administrative and other expenses 990 1,572 Total operating lease cost $ 5,922 $ 17,647 Finance lease cost: Amortization of leased assets Cost of products sold $ 2,377 $ 7,054 Interest on lease liabilities Interest expense, net 2,788 8,451 Total finance lease cost $ 5,165 $ 15,505 Total lease cost $ 11,087 $ 33,152 Supplemental cash flow information related to our leases is as follows (in thousands): Nine Months (39 Weeks) Ended Sept. 28, 2019 Cash paid for amounts included in measurement of lease liabilities: Operating cash flows from operating leases $ 16,766 Operating cash flows from finance leases $ 8,451 Financing cash flows from finance leases $ 6,538 Supplemental balance sheet information related to our leases is as follows (in thousands): Balance Sheet Classification Sept. 28, 2019 Assets: Operating lease Other assets $ 92,022 Finance lease Property, plant and equipment, net 67,554 Total leased $ 159,576 Liabilities: Current operating Accrued expenses and other current liabilities $ 17,362 Current finance Current portion of long-term debt and finance lease obligations 8,878 Non-current operating Deferred credits and other liabilities 75,854 Non-current finance Long-term debt and finance lease obligations due after one year 72,773 Total leased $ 174,867 Weighted-average remaining lease term and discount rate for our leases are as follows: Sept. 28, 2019 Weighted-average remaining lease term - operating leases 9.3 years Weighted-average remaining lease term - finance leases 10.3 years Weighted-average discount rate - operating leases 3.8% Weighted-average discount rate - finance leases 30.8% The reason for the substantial weighted-average discount rate – finance leases, of 30.8%, is due to Nucor’s past accounting for the respective finance leases following the former accounting guidance for capital leases. Pursuant to the former lease accounting guidance, the recognition of a capital lease asset and associated capital lease liability could not exceed the fair market value of the leased asset at the lease commencement. Accordingly, the incremental borrowing rate was adjusted upward so that the present value of the minimum lease payments would equal the fair value of the asset. Maturities of lease liabilities by fiscal year for our leases were as follows as of September 28, 2019 (in thousands): Operating Leases Finance Leases Maturities of lease liabilities, year ending December 31, 2019 $ 5,957 $ 4,904 2020 19,223 19,307 2021 16,853 18,833 2022 15,248 18,038 2023 12,161 16,194 Thereafter 44,265 79,529 Total lease payments $ 113,707 $ 156,805 Less imputed interest (20,491 ) (75,154 ) Present value of lease liabilities $ 93,216 $ 81,651 Prior Period Disclosures - As a result of adopting the new lease accounting guidance on January 1, 2019 under the modified retrospective approach, the Company is required to present future minimum lease commitments for capital leases and operating leases having initial or noncancellable lease terms in excess of one year that were previously disclosed in our Annual Report on Form 10-K for the year ended December 31, 2018 and accounted for under previous lease guidance. Total future minimum lease payments related to capital leases at December 31, 2018 were $154.8 million, with the timing of those payments estimated at that date to be made as follows: $17.7 million in 2019; a total of $33.6 million to be paid between 2020 and 2021; a total of $30.0 million to be paid between 2022 and 2023; and $73.4 million to be paid thereafter. Total future minimum lease payments related to operating leases having initial or noncancellable lease terms in excess of one year at December 31, 2018 were $128.6 million, with the timing of those payments estimated at that date to be made as follows: $31.8 million in 2019; a total of $45.0 million to be paid between 2020 and 2021; a total of $28.4 million to be paid between 2022 and 2023; and $23.5 million to be paid thereafter. The gross amount of assets recorded under capital leases was $89.4 million as of December 31, 2018, which primarily consisted of buildings and improvements or machinery and equipment.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 28, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	5. Steel Mills Steel Products Raw Materials Total Balance at December 31, 2018 $ 591,986 $ 862,773 $ 729,577 $ 2,184,336 Translation - 2,163 - 2,163 Balance at September 28, 2019 $ 591,986 $ 864,936 $ 729,577 $ 2,186,499 Nucor completed its most recent annual goodwill impairment testing during the fourth quarter of 2018 and concluded that as of such time there was no impairment of goodwill for any of its reporting units. The assessment performed in 2018 used forward-looking projections and included significant expected improvements in the future cash flows of one of the Company’s reporting units, Rebar Fabrication. The fair value of this reporting unit exceeded its carrying value by approximately 8% in the most recent assessment. We expect the 2019 operating results of this reporting unit to improve as compared to 2018. If our assessment of the relevant facts and circumstances changes, or the actual performance of this reporting unit falls short of expected results, noncash impairment charges may be required. Total goodwill associated with the Rebar Fabrication reporting unit was $354.9 million as of September 28, 2019 ($353.0 million as of December 31, 2018). An impairment of goodwill may also lead us to record an impairment of other intangible assets. Total finite-lived intangible assets associated with the Rebar Fabrication reporting unit were $69.4 million as of September 28, 2019 ($76.7 million as of December 31, 2018). There have been no triggering events requiring an interim assessment for impairment of the Rebar Fabrication reporting unit since the most recent annual goodwill impairment testing date. The Company has monitored one of its reporting units, Grating, for potential triggering events since the impairment assessment performed in the fourth quarter of 2018. Due to lower than expected operating performance and anticipated changes to the reporting unit’s business strategy and structure, the Company determined a triggering event occurred in the third quarter of 2019 and performed an impairment assessment. The fair value of the Grating reporting unit exceeded its carrying value by approximately 17% in the most recent assessment. If our assessment of the relevant facts and circumstances changes, or the actual performance of this reporting unit falls short of expected results, noncash impairment charges may be required. An impairment of goodwill may also lead us to record an impairment of other intangible assets. As of September 28, 2019, total goodwill and finite-lived intangible assets associated with the Grating reporting unit were $36.7 million and $3.3 million, respectively. Intangible assets with estimated useful lives of five to 22 years are amortized on a straight-line or accelerated basis and were comprised of the following as of September 28, 2019 and December 31, 2018 (in thousands): September 28, 2019 December 31, 2018 Gross Amount Accumulated Amortization Gross Amount Accumulated Amortization Customer relationships $ 1,421,107 $ 767,027 $ 1,418,250 $ 713,656 Trademarks and trade names 177,620 95,450 176,046 87,680 Other 63,807 35,790 67,820 32,276 $ 1,662,534 $ 898,267 $ 1,662,116 $ 833,612 Intangible asset amortization expense in the third quarter of 2019 and 2018 was $22.0 million and $22.1 million, respectively, and was $64.7 million and $66.7 million in the first nine months of 2019 and 2018, respectively. Annual amortization expense is estimated to be $87.1 million in 2019; $84.7 million in 2020; $83.5 million in 2021; $81.2 million in 2022; and $80.0 million in 2023.

Equity Investments

Equity Investments	9 Months Ended
	Sep. 28, 2019
Equity Method Investments And Joint Ventures [Abstract]
Equity Investments	6. NUMIT Nucor owns a 50% economic and voting interest in NuMit LLC (“NuMit”). NuMit owns 100% of the equity interest in Steel Technologies LLC, an operator of 26 sheet processing facilities located throughout the United States, Canada and Mexico. Nucor accounts for the investment in NuMit (on a one-month lag basis) under the equity method, as control and risk of loss are shared equally between the members. Nucor’s investment in NuMit was $323.9 million at September 28, 2019 ($337.2 million at December 31, 2018). Nucor received distributions of $27.4 million and $28.3 million from NuMit during the first nine months of 2019 and 2018, respectively. DUFERDOFIN NUCOR Nucor owns a 50% economic and voting interest in Duferdofin Nucor S.r.l. (“Duferdofin Nucor”), an Italian steel manufacturer, and accounts for the investment (on a one-month lag basis) under the equity method, as control and risk of loss are shared equally between the members. Nucor’s investment in Duferdofin Nucor was $256.0 million at September 28, 2019 ($269.1 million at December 31, 2018). Nucor’s 50% share of the total net assets of Duferdofin Nucor was $107.0 million at September 28, 2019, resulting in a basis difference of $149.0 million due to the step-up to fair value of certain assets and liabilities attributable to Duferdofin Nucor as well as the identification of goodwill ($84.3 million) and finite-lived intangible assets. This basis difference, excluding the portion attributable to goodwill, is being amortized based on the remaining estimated useful lives of the various underlying net assets, as appropriate. Amortization expense associated with the fair value step-up was $2.2 million and $ 2.3 million in the third quarter of 2019 and 2018 , respectively, and was $ 6.7 million and $ 7.1 million in the first nine months of 2019 and 2018, respectively. As of September 28, 2019, Nucor had outstanding notes receivable of €35.0 million ($38.3 million) from Duferdofin Nucor (€35.0 million, or $40.2 million, as of December 31, 2018). The notes receivable bear interest at a rate that resets annually on September 30 to the 12-month Euro Interbank Offered Rate plus 0.75% per year. The maturity date of the principal amounts was extended to January 31, 2022 during the first quarter of 2018. As of September 28, 2019 and December 31, 2018, the notes receivable were classified in other assets in the condensed consolidated balance sheets. Nucor has issued a guarantee for its ownership percentage (50%) of Duferdofin Nucor’s borrowings under Facility A of a Structured Trade Finance Facilities Agreement (“Facility A”). The fair value of the guarantee is immaterial. In April 2018, Duferdofin Nucor amended and extended Facility A to mature on April 16, 2021. The maximum amount Duferdofin Nucor could borrow under Facility A was €160.0 million ($175.1 million) at September 28, 2019. As of September 28, 2019, there was €154.0 million ($168.5 million) outstanding under that facility (€155.0 million, or $178.0 million, as of December 31, 2018). If Duferdofin Nucor fails to pay when due any amounts for which it is obligated under Facility A, Nucor could be required to pay 50% of such amounts pursuant to and in accordance with the terms of its guarantee. Any indebtedness of Duferdofin Nucor to Nucor is effectively subordinated to the indebtedness of Duferdofin Nucor under Facility A. Nucor has not recorded any liability associated with this guarantee. NUCOR-JFE Nucor owns a 50% economic and voting interest in Nucor-JFE Steel Mexico, S. de R.L. de C.V. (“Nucor-JFE”), a 50-50 joint venture with JFE Steel Corporation of Japan, to build and operate a galvanized sheet steel plant in central Mexico. Nucor-JFE plant construction is substantially complete and operations are expected to begin by the end of 2019. Nucor accounts for the investment in Nucor-JFE (on a one-month lag basis) under the equity method, as control and risk of loss are shared equally between the members. Nucor’s investment in Nucor-JFE was $150.1 million at September 28, 2019 ($135.7 million at December 31, 2018). On January 16, 2019, Nucor entered into an agreement to guarantee a percentage, equal to its ownership percentage (50%), of Nucor-JFE’s borrowings under the General Financing Agreement and Promissory Note (the “Facility”). The fair value of the guarantee is immaterial. Nucor’s guarantee expires on April 30, 2020. Under the Facility, the maximum amount Nucor-JFE could borrow was $65.0 million as of September 28, 2019. The Facility is uncommitted. As of September 28, 2019, there was $30.0 million outstanding under the Facility. If Nucor-JFE fails to pay when due any amounts for which it is obligated under the Facility, Nucor could be required to pay 50% of such amounts pursuant to and in accordance with the terms of its guarantee. Nucor has not recorded any liability associated with this guarantee. On July 26, 2019, Nucor entered into another agreement to guarantee $17.5 million of debt, plus interest and fees, totaling up to $20.0 million under the $35.0 million Uncommitted Loan Facility Agreement and Promissory Note (the “Loan Agreement”). The fair value of the guarantee is immaterial. Nucor’s guarantee expires on July 31, 2024. If Nucor-JFE fails to pay when due any amounts for which it is obligated under the Loan Agreement, Nucor could be required to pay such amounts pursuant to and in accordance with the terms of its guarantee. Nucor has not recorded any liability associated with this guarantee. ALL EQUITY INVESTMENTS Nucor reviews its equity investments for impairment if and when circumstances indicate that a decline in fair value below their carrying amounts may have occurred. Nucor last assessed its equity investment in Duferdofin Nucor for impairment during the fourth quarter of 2017 due to the protracted challenging steel market conditions in Europe. After completing its assessment, the Company determined that the estimated fair value exceeded its carrying amount by a sufficient amount and that there was no need to record an impairment charge. The assumptions that most significantly affect the fair value determination include projected cash flows and the discount rate. It is reasonably possible that material deviation of future performance from the estimates used in our most recent valuation could result in impairment of our investment in Duferdofin Nucor. The outlook for the European economy has weakened in 2019. We will continue to monitor for potential triggering events that could affect the carrying value of our investment in Duferdofin Nucor as a result of future market conditions and any changes in our business strategy.

Current Liabilities

Current Liabilities	9 Months Ended
	Sep. 28, 2019
Payables And Accruals [Abstract]
Current Liabilities	7.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 28, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	8. Fair Value Measurements at Reporting Date Using Description Carrying Amount in Condensed Consolidated Balance Sheets Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of September 28, 2019 Assets: Cash equivalents $ 1,445,116 $ 1,445,116 $ - $ - Short-term investments 249,616 249,616 - - Derivative contracts 2,228 - 2,228 - Total assets $ 1,696,960 $ 1,694,732 $ 2,228 $ - Liabilities: Derivative contracts $ (16,800 ) $ - $ (16,800 ) $ - As of December 31, 2018 Assets: Cash equivalents $ 1,084,319 $ 1,084,319 $ - $ - Derivative contracts 4,772 - 4,772 - Total assets $ 1,089,091 $ 1,084,319 $ 4,772 $ - Liabilities: Derivative contracts $ (8,600 ) $ - $ (8,600 ) $ - Fair value measurements for Nucor’s cash equivalents and short-term investments are classified under Level 1 because such measurements are based on quoted market prices in active markets for identical assets. Our short-term investments at September 28, 2019 consisted of certificates of deposit, commercial paper and corporate notes. Fair value measurements for Nucor’s derivatives are classified under Level 2 because such measurements are based on published market prices for similar assets or are estimated based on observable inputs such as interest rates, yield curves, credit risks, spot and future commodity prices, and spot and future exchange rates. The fair value of short-term and long-term debt, including current maturities, was approximately $4.83 billion at September 28, 2019 ($4.45 billion at December 31, 2018). The debt fair value estimates are classified under Level 2 because such estimates are based on readily available market prices of our debt at September 28, 2019 and December 31, 2018, or similar debt with the same maturities, ratings and interest rates.

Contingencies

Contingencies	9 Months Ended
	Sep. 28, 2019
Commitments And Contingencies Disclosure [Abstract]
Contingencies	9. We are from time to time a party to various lawsuits, claims and other legal proceedings that arise in the ordinary course of business. With respect to all such lawsuits, claims and proceedings, we record reserves when it is probable a liability has been incurred and the amount of loss can be reasonably estimated. We do not believe that any of these proceedings, individually or in the aggregate, would be expected to have a material adverse effect on our results of operations, financial position or cash flows. Nucor maintains liability insurance with self-insurance limits for certain risks.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 28, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	10. Overview The Company also maintains a number of inactive plans under which stock-based awards remain outstanding but no further awards may be made. As of September 28, 2019, 1.5 million shares were reserved for issuance upon the future settlement of outstanding awards under such inactive plans. Stock Options – Stock options may be granted to Nucor’s key employees, officers and non-employee directors with exercise prices at 100% of the market value on the date of the grant. The stock options granted are generally exercisable at the end of three years and have a term of 10 years. A summary of activity under Nucor’s stock option plans for the first nine months of 2019 is as follows (in thousands, except years and per share amounts): Weighted- Weighted- Average Average Aggregate Exercise Remaining Intrinsic Shares Price Contractual Life Value Number of shares under stock options: Outstanding at beginning of year 3,828 $ 49.71 Granted 489 $ 48.00 Exercised (153 ) $ 38.56 $ 3,058 Canceled - $ - Outstanding at September 28, 2019 4,164 $ 49.92 5.9 years $ 11,151 Stock options exercisable at September 28, 2019 2,914 $ 47.13 4.7 years $ 10,283 Stock options granted to employees who are eligible for retirement on the date of the grant are expensed immediately since these awards vest upon retirement from the Company. Retirement, for purposes of vesting in these stock options, means termination of employment after satisfying age and years of service requirements. Similarly, stock options granted to employees who will become retirement-eligible prior to the end of the vesting term are expensed over the period through which the employee will become retirement-eligible. Compensation expense for stock options granted to employees who will not become retirement-eligible prior to the end of the vesting term is recognized on a straight-line basis over the vesting period. Compensation expense for stock options was $0.3 million in the third quarter of both 2019 and 2018 and $4.4 million and $4.3 million in the first nine months of 2019 and 2018, respectively. As of September 28, 2019, unrecognized compensation expense related to stock options was $1.5 million, which is expected to be recognized over a weighted-average period of 1.8 years. Restricted Stock Units – Nucor annually grants restricted stock units (“RSUs”) to key employees, officers and non-employee directors. The RSUs granted to key employees and officers vest and are converted to common stock in three equal installments on each of the first three anniversaries of the grant date, provided that a portion of the RSUs awarded to officers prior to 2018 vests only upon the officer’s retirement. Retirement, for purposes of vesting in these RSUs only, means termination of employment with approval of the Compensation and Executive Development Committee of the Board of Directors after satisfying age and years of service requirements. RSUs granted to a non-employee director are fully vested on the grant date and are payable to the non-employee director in the form of common stock after the termination of the director’s service on the Board of Directors. RSUs granted to employees who are eligible for retirement on the date of the grant are expensed immediately, and RSUs granted to employees who will become retirement-eligible prior to the end of the vesting term are expensed over the period through which the employee will become retirement-eligible since these awards vest upon retirement from the Company. Compensation expense for RSUs granted to employees who will not become retirement-eligible prior to the end of the vesting term is recognized on a straight-line basis over the vesting period. Cash dividend equivalents are paid to holders of RSUs each quarter. Dividend equivalents paid on RSUs expected to vest are recognized as a reduction in retained earnings. The fair value of an RSU is determined based on the closing price of Nucor’s common stock on the date of the grant . Shares Grant Date Fair Value Restricted stock units: Unvested at beginning of year 1,246 $ 59.09 Granted 1,770 $ 48.00 Vested (1,177 ) $ 52.39 Canceled (29 ) $ 57.53 Unvested at September 28, 2019 1,810 $ 52.62 Compensation expense for RSUs was $11.0 million and $8.5 million in the third quarter of 2019 and 2018, respectively, and $59.1 million and $46.8 million in the first nine months of 2019 and 2018, respectively. As of September 28, 2019, unrecognized compensation expense related to unvested RSUs was $70.2 million, which is expected to be recognized over a weighted-average period of 1.7 years. Restricted Stock Awards – Prior to their expiration effective December 31, 2017, the Nucor Corporation Senior Officers Long-Term Incentive Plan and the Nucor Corporation Senior Officers Annual Incentive Plan authorized the award of shares of common stock to officers subject to certain conditions and restrictions. Effective January 1, 2018, the Company adopted supplements to the Omnibus Plan with terms that permit the award of shares of common stock to officers subject to the conditions and restrictions described below, which are substantially similar to those of the expired Senior Officers Long-Term Incentive Plan and Senior Officers Annual Incentive Plan. The expired Senior Officers Long-Term Incentive Plan, together with the applicable supplement, is referred to below as the “LTIP,” and the expired Senior Officers Annual Incentive Plan, together with the applicable supplement, is referred to below as the “AIP.” The LTIP provides for the award of shares of restricted common stock at the end of each LTIP performance measurement period at no cost to officers if certain financial performance goals are met during the period. One-third of the LTIP restricted stock award vests upon each of the first three anniversaries of the award date or, if earlier, upon the officer’s attainment of age 55 while employed by Nucor. Although LTIP participants are entitled to cash dividends and may vote such awarded shares, the sale or transfer of such shares is limited during the restricted period. The AIP provides for the payment of annual cash incentive awards. An AIP participant may elect, however, to defer payment of up to one-half of an AIP award. In such event, the deferred AIP award is converted into common stock units and credited with a deferral incentive, in the form of additional common stock units, equal to 25% of the number of common stock units attributable to the deferred AIP award. Common stock units attributable to deferred AIP awards are fully vested. Common stock units credited as a deferral incentive vest upon the AIP participant’s attainment of age 55 while employed by Nucor. Vested common stock units are paid to AIP participants in the form of shares of common stock following their termination of employment with Nucor. A summary of Nucor’s restricted stock activity under the AIP and the LTIP for the first nine months of 2019 is as follows (shares in thousands): Grant Date Shares Fair Value Restricted stock units and restricted stock awards: Unvested at beginning of year 130 $ 62.97 Granted 316 $ 58.04 Vested (296 ) $ 58.78 Canceled - $ - Unvested at September 28, 2019 150 $ 60.84 Compensation expense for common stock and common stock units awarded under the AIP and the LTIP is recorded over the performance measurement and vesting periods based on the anticipated number and market value of shares of common stock and common stock units to be awarded. Compensation expense for anticipated awards based upon Nucor’s financial performance, exclusive of amounts payable in cash, was $1.8 million and $4.9 million in the third quarter of 2019 and 2018, respectively, and $10.9 million and $14.6 million in the first nine months of 2019 and 2018, respectively. As of September 28, 2019, unrecognized compensation expense related to unvested restricted stock awards was $2.1 million, which is expected to be recognized over a weighted-average period of 1.7 years.

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 28, 2019
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plans	11.

Interest Expense (Income)

Interest Expense (Income)	9 Months Ended
	Sep. 28, 2019
Banking And Thrift Interest [Abstract]
Interest Expense (Income)	12. Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 28, 2019 Sept. 29, 2018 Sept. 28, 2019 Sept. 29, 2018 Interest expense $ 40,721 $ 44,789 $ 119,736 $ 120,308 Interest income (9,435 ) (7,588 ) (26,977 ) (16,542 ) Interest expense, net $ 31,286 $ 37,201 $ 92,759 $ 103,766 Interest expense decreased in the third quarter and first nine months of 2019 as compared to the third quarter and first nine months of 2018 due to an increase in capitalized interest related to capital projects being constructed in the first nine months of 2019. Included in interest expense in the first nine months of 2018 was the benefit received from the settlement of a treasury lock instrument that was entered into in anticipation of the Company’s debt issuance that occurred in the second quarter of 2018. The Company did not elect hedge accounting for this instrument.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 28, 2019
Income Tax Disclosure [Abstract]
Income Taxes	13. Nucor has concluded U.S. federal income tax matters for years through 2014. The tax years 2015 through 2018 remain open to examination by the Internal Revenue Service. The Canada Revenue Agency has concluded its examination of the 2012 and 2013 Canadian returns for Harris Steel Group Inc. and certain related affiliates. The 2015 tax year is currently under examination by the Canada Revenue Agency. The Trinidad and Tobago Inland Revenue Division has concluded its examination of the Nu-Iron Unlimited 2013 corporate income tax return. The tax years 2012 through 2018 remain open to examination by other major taxing jurisdictions to which Nucor is subject (primarily Canada and other state and local jurisdictions). Non-current deferred tax assets included in other assets in the condensed consolidated balance sheets were $0.9 million at September 28, 2019 ($0.7 million at December 31, 2018). Non-current deferred tax liabilities included in deferred credits and other liabilities in the condensed consolidated balance sheets were $407.0 million at September 28, 2019 ($332.0 million at December 31, 2018).

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 28, 2019
Federal Home Loan Banks [Abstract]
Stockholders' Equity	14. 51% Three Months (13 Weeks) Ended September 28, 2019 Accumulated Total Additional Other Treasury Stock Nucor Common Stock Paid-in Retained Comprehensive (at cost) Stockholders' Noncontrolling Total Shares Amount Capital Earnings Income (Loss) Shares Amount Equity Interests BALANCES, June 29, 2019 $ 10,698,008 380,154 $ 152,061 $ 2,098,809 $ 10,977,950 $ (297,760 ) 76,997 $ (2,630,343 ) $ 10,300,717 $ 397,291 Net earnings 293,587 - - - 275,031 - - - 275,031 18,556 Other comprehensive income (loss) (16,006 ) - - - - (16,006 ) - - (16,006 ) - Stock options exercised - - - - - - - - - - Stock option expense 275 - - 275 - - - - 275 - Issuance of stock under award plans, net of forfeitures 11,339 - - 9,365 - - (58 ) 1,974 11,339 - Amortization of unearned compensation 500 - - 500 - - - - 500 - Treasury stock acquired - - - - - - - - - - Cash dividends declared (122,809 ) - - - (122,809 ) - - - (122,809 ) - Distributions to noncontrolling interests (3,861 ) - - - - - - - - (3,861 ) Other - - - (1 ) - - - 1 - - BALANCES, September 28, 2019 $ 10,861,033 380,154 $ 152,061 $ 2,108,948 $ 11,130,172 $ (313,766 ) 76,939 $ (2,628,368 ) $ 10,449,047 $ 411,986 Nine Months (39 Weeks) Ended September 28, 2019 Accumulated Total Additional Other Treasury Stock Nucor Common Stock Paid-in Retained Comprehensive (at cost) Stockholders' Noncontrolling Total Shares Amount Capital Earnings Income (Loss) Shares Amount Equity Interests BALANCES, December 31, 2018 $ 10,201,968 380,154 $ 152,061 $ 2,073,715 $ 10,337,445 $ (304,133 ) 74,562 $ (2,467,010 ) $ 9,792,078 $ 409,890 Net earnings 1,236,657 - - - 1,163,320 - - - 1,163,320 73,337 Other comprehensive income (loss) (11,519 ) - - - - (11,519 ) - - (11,519 ) - Stock options exercised 5,892 - - 808 - - (153 ) 5,084 5,892 - Stock option expense 4,387 - - 4,387 - - - - 4,387 - Issuance of stock under award plans, net of forfeitures 59,608 - - 28,540 - - (920 ) 31,068 59,608 - Amortization of unearned compensation 1,500 - - 1,500 - - - - 1,500 - Treasury stock acquired (197,511 ) - - - - - 3,450 (197,511 ) (197,511 ) - Cash dividends declared (368,707 ) - - - (368,707 ) - - - (368,707 ) - Distributions to noncontrolling interests (71,241 ) - - - - - - - - (71,241 ) Other (1 ) - - (2 ) (1,886 ) 1,886 - 1 (1 ) - BALANCES, September 28, 2019 $ 10,861,033 380,154 $ 152,061 $ 2,108,948 $ 11,130,172 $ (313,766 ) 76,939 $ (2,628,368 ) $ 10,449,047 $ 411,986 Three Months (13 Weeks) Ended September 29, 2018 Accumulated Total Additional Other Treasury Stock Nucor Common Stock Paid-in Retained Comprehensive (at cost) Stockholders' Noncontrolling Total Shares Amount Capital Earnings Income (Loss) Shares Amount Equity Interests BALANCES, June 30, 2018 $ 9,735,424 380,154 $ 152,061 $ 2,051,383 $ 9,257,822 $ (296,032 ) 63,810 $ (1,791,827 ) $ 9,373,407 $ 362,017 Net earnings 706,287 - - - 676,656 - - - 676,656 29,631 Other comprehensive income (loss) 21,425 - - - - 21,425 - - 21,425 - Stock options exercised 11,822 - - 4,572 - - (256 ) 7,250 11,822 - Stock option expense 312 - - 312 - - - - 312 - Issuance of stock under award plans, net of forfeitures 9,598 - - 8,633 - - (34 ) 965 9,598 - Amortization of unearned compensation 400 - - 400 - - - - 400 - Treasury stock acquired (181,077 ) - - - - - 2,701 (181,077 ) (181,077 ) - Cash dividends declared (120,406 ) - - - (120,406 ) - - - (120,406 ) - Distributions to noncontrolling interests (9,364 ) - - - - - - - - (9,364 ) Other - - - (1 ) 1 - - - - - BALANCES, September 29, 2018 $ 10,174,421 380,154 $ 152,061 $ 2,065,299 $ 9,814,073 $ (274,607 ) 66,221 $ (1,964,689 ) $ 9,792,137 $ 382,284 Nine Months (39 Weeks) Ended September 29, 2018 Accumulated Total Additional Other Treasury Stock Nucor Common Stock Paid-in Retained Comprehensive (at cost) Stockholders' Noncontrolling Total Shares Amount Capital Earnings Income (Loss) Shares Amount Equity Interests BALANCES, December 31, 2017 $ 9,084,788 379,900 $ 151,960 $ 2,021,339 $ 8,463,709 $ (254,681 ) 61,931 $ (1,643,291 ) $ 8,739,036 $ 345,752 Net earnings 1,800,014 - - - 1,713,988 - - - 1,713,988 86,026 Other comprehensive income (loss) (19,926 ) - - - - (19,926 ) - - (19,926 ) - Stock options exercised 24,102 210 84 14,675 - - (334 ) 9,343 24,102 - Stock option expense 4,249 - - 4,249 - - - - 4,249 - Issuance of stock under award plans, net of forfeitures 44,304 44 17 23,636 - - (754 ) 20,651 44,304 - Amortization of unearned compensation 1,400 - - 1,400 - - - - 1,400 - Treasury stock acquired (351,392 ) - - - - - 5,378 (351,392 ) (351,392 ) - Cash dividends declared (363,624 ) - - - (363,624 ) - - - (363,624 ) - Distributions to noncontrolling interests (49,494 ) - - - - - - - - (49,494 ) BALANCES, September 29, 2018 $ 10,174,421 380,154 $ 152,061 $ 2,065,299 $ 9,814,073 $ (274,607 ) 66,221 $ (1,964,689 ) $ 9,792,137 $ 382,284 Dividends declared per share were $0.40 per share in the third quarter of 2019 ($0.38 per share in the third quarter of 2018) and $1.20 per share in the first nine months of 2019 ($1.14 per share in the first nine months of 2018). In September 2018, the Company announced that the Board of Directors had approved a share repurchase program under which the Company is authorized to repurchase up to $2.0 billion of the Company’s common stock. Share repurchases will be made from time to time in the open market at prevailing market prices or through private transactions or block trades. The timing and amount of repurchases will depend on market conditions, share price, applicable legal requirements and other factors. The share repurchase authorization is discretionary and has no expiration date. The Board of Directors also terminated any previously authorized share repurchase programs. As of September 28, 2019, the Company had approximately $1.3 billion remaining available for share repurchases under the program.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 28, 2019
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	15. Three-Month (13-Week) Period Ended September 28, 2019 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive income (loss) at June 29, 2019 $ (11,100 ) $ (295,559 ) $ 8,899 $ (297,760 ) Other comprehensive income (loss) before reclassifications (3,315 ) (14,306 ) - (17,621 ) Amounts reclassified from accumulated other comprehensive income (loss) into earnings (1) 1,615 - - 1,615 Net current-period other comprehensive income (loss) (1,700 ) (14,306 ) - (16,006 ) Accumulated other comprehensive income (loss) at September 28, 2019 $ (12,800 ) $ (309,865 ) $ 8,899 $ (313,766 ) Nine-Month (39-Week) Period Ended September 28, 2019 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive income (loss) at December 31, 2018 $ (6,500 ) $ (304,646 ) $ 7,013 $ (304,133 ) Other comprehensive income (loss) before reclassifications (7,801 ) (5,219 ) - (13,020 ) Amounts reclassified from accumulated other comprehensive income (loss) into earnings (1) 1,501 - - 1,501 Net current-period other comprehensive income (loss) (6,300 ) (5,219 ) - (11,519 ) Other - - 1,886 1,886 Accumulated other comprehensive income (loss) at September 28, 2019 $ (12,800 ) $ (309,865 ) $ 8,899 $ (313,766 ) ( 1) 2019 2019 Three-Month (13-Week) Period Ended September 29, 2018 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive income (loss) at June 30, 2018 $ (6,800 ) $ (294,864 ) $ 5,632 $ (296,032 ) Other comprehensive income (loss) before reclassifications (1,393 ) 22,625 - 21,232 Amounts reclassified from accumulated other comprehensive income (loss) into earnings (2) 193 - - 193 Net current-period other comprehensive income (loss) (1,200 ) 22,625 - 21,425 Accumulated other comprehensive income (loss) at September 29, 2018 $ (8,000 ) $ (272,239 ) $ 5,632 $ (274,607 ) Nine-Month (39-Week) Period Ended September 29, 2018 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive income (loss) at December 31, 2017 $ (2,800 ) $ (257,513 ) $ 5,632 $ (254,681 ) Other comprehensive income (loss) before reclassifications (5,792 ) (14,726 ) - (20,518 ) Amounts reclassified from accumulated other comprehensive income (loss) into earnings (2) 592 - - 592 Net current-period other comprehensive income (loss) (5,200 ) (14,726 ) - (19,926 ) Accumulated other comprehensive income (loss) at September 29, 2018 $ (8,000 ) $ (272,239 ) $ 5,632 $ (274,607 ) (2) Includes $ 193 and $ 592 of accumulated other comprehensive income (loss) reclassifications into cost of products sold for net losses on commodity contracts in the third quarter and first nine months of 2018 , respectively. The tax impact of those reclassifications w as $ 100 and $ 200 in the third quarter and first nine months of 2018 , respectively .

Segments

Segments	9 Months Ended
	Sep. 28, 2019
Segment Reporting [Abstract]
Segments	16. Net interest expense on long-term debt, charges and credits associated with changes in allowances to eliminate intercompany profit in inventory, profit sharing expense and stock-based compensation are shown under Corporate/eliminations. Corporate assets primarily include cash and cash equivalents, short-term investments, allowances to eliminate intercompany profit in inventory, deferred income tax assets, federal and state income taxes receivable and investments in and advances to affiliates. Nucor’s results by segment for the third quarter and first nine months of 2019 and 2018 were as follows (in thousands): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 28, 2019 Sept. 29, 2018 Sept. 28, 2019 Sept. 29, 2018 Net sales to external customers: Steel mills $ 3,244,473 $ 4,401,610 $ 10,897,322 $ 12,151,843 Steel products 1,820,359 1,849,218 5,225,064 5,056,299 Raw materials 399,670 491,374 1,334,726 1,563,253 $ 5,464,502 $ 6,742,202 $ 17,457,112 $ 18,771,395 Intercompany sales: Steel mills $ 825,237 $ 1,055,093 $ 2,542,008 $ 3,019,199 Steel products 57,517 56,185 174,718 142,862 Raw materials 2,063,167 2,923,196 6,917,523 8,687,408 Corporate/eliminations (2,945,921 ) (4,034,474 ) (9,634,249 ) (11,849,469 ) $ - $ - $ - $ - Earnings (loss) before income taxes and noncontrolling interests: Steel mills $ 309,939 $ 1,095,360 $ 1,578,257 $ 2,617,647 Steel products 170,214 138,688 363,731 380,268 Raw materials (10,599 ) (29,074 ) 64,333 180,468 Corporate/eliminations (89,215 ) (282,472 ) (401,744 ) (826,268 ) $ 380,339 $ 922,502 $ 1,604,577 $ 2,352,115 Sept. 28, 2019 Dec. 31, 2018 Segment assets: Steel mills $ 9,117,610 $ 9,244,086 Steel products 4,730,410 4,734,636 Raw materials 3,225,367 3,492,126 Corporate/eliminations 1,432,878 449,740 $ 18,506,265 $ 17,920,588

Revenue

Revenue	9 Months Ended
	Sep. 28, 2019
Revenue From Contract With Customer [Abstract]
Revenue	17. Three Months (13 Weeks) Ended September 28, 2019 Nine Months (39 Weeks) Ended September 28, 2019 Steel Mills Steel Products Raw Materials Total Steel Mills Steel Products Raw Materials Total Sheet $ 1,513,884 $ - $ - $ 1,513,884 $ 5,071,027 $ - $ - $ 5,071,027 Bar 979,082 - - 979,082 3,173,289 - - 3,173,289 Structural 378,670 - - 378,670 1,214,355 - - 1,214,355 Plate 372,837 - - 372,837 1,438,651 - - 1,438,651 Tubular Products - 296,519 - 296,519 - 919,711 - 919,711 Rebar Fabrication - 469,180 - 469,180 - 1,249,912 - 1,249,912 Other Steel Products - 1,054,660 - 1,054,660 - 3,055,441 - 3,055,441 Raw Materials - - 399,670 399,670 - - 1,334,726 1,334,726 $ 3,244,473 $ 1,820,359 $ 399,670 $ 5,464,502 $ 10,897,322 $ 5,225,064 $ 1,334,726 $ 17,457,112 Three Months (13 Weeks) Ended September 29, 2018 Nine Months (39 Weeks) Ended September 29, 2018 Steel Mills Steel Products Raw Materials Total Steel Mills Steel Products Raw Materials Total Sheet $ 2,051,634 $ - $ - $ 2,051,634 $ 5,692,281 $ - $ - $ 5,692,281 Bar 1,243,890 - - 1,243,890 3,592,475 - - 3,592,475 Structural 503,733 - - 503,733 1,348,987 - - 1,348,987 Plate 602,353 - - 602,353 1,518,100 - - 1,518,100 Tubular Products - 357,815 - 357,815 - 1,040,611 - 1,040,611 Rebar Fabrication - 412,977 - 412,977 - 1,133,117 - 1,133,117 Other Steel Products - 1,078,426 - 1,078,426 - 2,882,571 - 2,882,571 Raw Materials - - 491,374 491,374 - - 1,563,253 1,563,253 $ 4,401,610 $ 1,849,218 $ 491,374 $ 6,742,202 $ 12,151,843 $ 5,056,299 $ 1,563,253 $ 18,771,395

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 28, 2019
Earnings Per Share [Abstract]
Earnings Per Share	18. Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 28, 2019 Sept. 29, 2018 Sept. 28, 2019 Sept. 29, 2018 Basic net earnings per share: Basic net earnings $ 275,031 $ 676,656 $ 1,163,320 $ 1,713,988 Earnings allocated to participating securities (1,655 ) (2,807 ) (6,295 ) (6,707 ) Net earnings available to common stockholders $ 273,376 $ 673,849 $ 1,157,025 $ 1,707,281 Average shares outstanding 304,637 315,913 305,553 317,928 Basic net earnings per share $ 0.90 $ 2.13 $ 3.79 $ 5.37 Diluted net earnings per share: Diluted net earnings $ 275,031 $ 676,656 $ 1,163,320 $ 1,713,988 Earnings allocated to participating securities (1,656 ) (2,796 ) (6,295 ) (6,684 ) Net earnings available to common stockholders $ 273,375 $ 673,860 $ 1,157,025 $ 1,707,304 Diluted average shares outstanding: Basic shares outstanding 304,637 315,913 305,553 317,928 Dilutive effect of stock options and other 343 885 476 954 304,980 316,798 306,029 318,882 Diluted net earnings per share $ 0.90 $ 2.13 $ 3.78 $ 5.35 The following stock options were excluded from the computation of diluted net earnings per share for the third quarter and first nine months of 2019 and 2018 because their effect would have been anti-dilutive (shares in thousands): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 28, 2019 Sept. 29, 2018 Sept. 28, 2019 Sept. 29, 2018 Anti-dilutive stock options: Weighted-average shares 963 265 963 89 Weighted-average exercise price $ 60.92 $ 65.80 $ 60.92 $ 65.80

Basis of Interim Presentation (

Basis of Interim Presentation (Policies)	9 Months Ended
	Sep. 28, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements – In the first quarter of 2019, Nucor adopted new guidance related to lease accounting using the modified retrospective approach, which permits companies to recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption without adjusting the comparative periods prior to adoption. The new lease guidance requires all lessees to recognize on the balance sheet right-of-use assets and lease liabilities for the rights and obligations created by lease arrangements with terms greater than 12 months, including operating leases. Expenses are recognized in the statement of earnings in a manner similar to previous accounting guidance. We elected the package of practical expedients permitted under the transition guidance within the new lease standard, which, among other things, allowed us to carry forward the historical lease classification. We also elected the practical expedient related to land easements, allowing us to carry forward our accounting treatment for land easements on existing agreements, and the short-term lease exemption policy such that the new lease guidance was applied to leases greater than one year in duration. The adoption of the new lease standard did not have a material impact on our consolidated financial statements as it resulted in an increase of 0.5% and 1.2% to our total assets and total liabilities, respectively, on our consolidated balance sheet at January 1, 2019. The new lease standard did not materially impact our consolidated net earnings and had no impact on our cash flows. Finance lease right-of-use assets and liabilities are presented separately from operating lease right-of-use assets and liabilities in the condensed consolidated balance sheet in accordance with the new lease standard. See Note 4 for further information. In the first quarter of 2019, we also adopted new accounting guidance related to tax effects of the Tax Cuts and Jobs Act of 2017. As a result of the adoption of the new guidance, we elected to reclassify stranded tax effects from accumulated other comprehensive income to retained earnings, effective January 1, 2019. The adoption of this new guidance did not have a material impact on the Company’s consolidated financial statements.

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 28, 2019
Disclosure Of Leases [Abstract]
Supplemental statement of earnings information leases operating finance	Supplemental statement of earnings information related to our leases is as follows (in thousands): Three Months Nine Months (13 Weeks) Ended (39 Weeks) Ended Statement of Earnings Classification Sept. 28, 2019 Sept. 28, 2019 Operating lease cost Cost of products sold $ 4,932 $ 16,075 Operating lease cost Marketing, administrative and other expenses 990 1,572 Total operating lease cost $ 5,922 $ 17,647 Finance lease cost: Amortization of leased assets Cost of products sold $ 2,377 $ 7,054 Interest on lease liabilities Interest expense, net 2,788 8,451 Total finance lease cost $ 5,165 $ 15,505 Total lease cost $ 11,087 $ 33,152
Supplemental cash flow information leases operating finance	Supplemental cash flow information related to our leases is as follows (in thousands): Nine Months (39 Weeks) Ended Sept. 28, 2019 Cash paid for amounts included in measurement of lease liabilities: Operating cash flows from operating leases $ 16,766 Operating cash flows from finance leases $ 8,451 Financing cash flows from finance leases $ 6,538
Lessee balance sheet information	Supplemental balance sheet information related to our leases is as follows (in thousands): Balance Sheet Classification Sept. 28, 2019 Assets: Operating lease Other assets $ 92,022 Finance lease Property, plant and equipment, net 67,554 Total leased $ 159,576 Liabilities: Current operating Accrued expenses and other current liabilities $ 17,362 Current finance Current portion of long-term debt and finance lease obligations 8,878 Non-current operating Deferred credits and other liabilities 75,854 Non-current finance Long-term debt and finance lease obligations due after one year 72,773 Total leased $ 174,867
Weighted average lease term discount rate finance operating	Weighted-average remaining lease term and discount rate for our leases are as follows: Sept. 28, 2019 Weighted-average remaining lease term - operating leases 9.3 years Weighted-average remaining lease term - finance leases 10.3 years Weighted-average discount rate - operating leases 3.8% Weighted-average discount rate - finance leases 30.8%
Lessee operating finance lease liability maturity	Maturities of lease liabilities by fiscal year for our leases were as follows as of September 28, 2019 (in thousands): Operating Leases Finance Leases Maturities of lease liabilities, year ending December 31, 2019 $ 5,957 $ 4,904 2020 19,223 19,307 2021 16,853 18,833 2022 15,248 18,038 2023 12,161 16,194 Thereafter 44,265 79,529 Total lease payments $ 113,707 $ 156,805 Less imputed interest (20,491 ) (75,154 ) Present value of lease liabilities $ 93,216 $ 81,651

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 28, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Change in Net Carrying Amount of Goodwill by Segment	The change in the net carrying amount of goodwill for the nine months ended September 28, 2019 by segment was as follows (in thousands): Steel Mills Steel Products Raw Materials Total Balance at December 31, 2018 $ 591,986 $ 862,773 $ 729,577 $ 2,184,336 Translation - 2,163 - 2,163 Balance at September 28, 2019 $ 591,986 $ 864,936 $ 729,577 $ 2,186,499
Schedule of Intangible Assets	September 28, 2019 December 31, 2018 Gross Amount Accumulated Amortization Gross Amount Accumulated Amortization Customer relationships $ 1,421,107 $ 767,027 $ 1,418,250 $ 713,656 Trademarks and trade names 177,620 95,450 176,046 87,680 Other 63,807 35,790 67,820 32,276 $ 1,662,534 $ 898,267 $ 1,662,116 $ 833,612

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 28, 2019
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value	The following table summarizes information regarding Nucor’s financial assets and financial liabilities that were measured at fair value as of September 28, 2019 and December 31, 2018 (in thousands). Nucor does not have any non-financial assets or non-financial liabilities that are measured at fair value on a recurring basis. Fair Value Measurements at Reporting Date Using Description Carrying Amount in Condensed Consolidated Balance Sheets Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of September 28, 2019 Assets: Cash equivalents $ 1,445,116 $ 1,445,116 $ - $ - Short-term investments 249,616 249,616 - - Derivative contracts 2,228 - 2,228 - Total assets $ 1,696,960 $ 1,694,732 $ 2,228 $ - Liabilities: Derivative contracts $ (16,800 ) $ - $ (16,800 ) $ - As of December 31, 2018 Assets: Cash equivalents $ 1,084,319 $ 1,084,319 $ - $ - Derivative contracts 4,772 - 4,772 - Total assets $ 1,089,091 $ 1,084,319 $ 4,772 $ - Liabilities: Derivative contracts $ (8,600 ) $ - $ (8,600 ) $ -

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 28, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Plans Activity	A summary of activity under Nucor’s stock option plans for the first nine months of 2019 is as follows (in thousands, except years and per share amounts): Weighted- Weighted- Average Average Aggregate Exercise Remaining Intrinsic Shares Price Contractual Life Value Number of shares under stock options: Outstanding at beginning of year 3,828 $ 49.71 Granted 489 $ 48.00 Exercised (153 ) $ 38.56 $ 3,058 Canceled - $ - Outstanding at September 28, 2019 4,164 $ 49.92 5.9 years $ 11,151 Stock options exercisable at September 28, 2019 2,914 $ 47.13 4.7 years $ 10,283
Summary of Nucor's RSU Activity	The fair value of an RSU is determined based on the closing price of Nucor’s common stock on the date of the grant . Shares Grant Date Fair Value Restricted stock units: Unvested at beginning of year 1,246 $ 59.09 Granted 1,770 $ 48.00 Vested (1,177 ) $ 52.39 Canceled (29 ) $ 57.53 Unvested at September 28, 2019 1,810 $ 52.62
Summary of Nucor's Restricted Stock Activity under AIP and LTIP	A summary of Nucor’s restricted stock activity under the AIP and the LTIP for the first nine months of 2019 is as follows (shares in thousands): Grant Date Shares Fair Value Restricted stock units and restricted stock awards: Unvested at beginning of year 130 $ 62.97 Granted 316 $ 58.04 Vested (296 ) $ 58.78 Canceled - $ - Unvested at September 28, 2019 150 $ 60.84

Interest Expense (Income) (Tabl

Interest Expense (Income) (Tables)	9 Months Ended
	Sep. 28, 2019
Banking And Thrift Interest [Abstract]
Schedule of Components of Net Interest Expense	The components of net interest expense for the third quarter and first nine months of 2019 and 2018 are as follows (in thousands): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 28, 2019 Sept. 29, 2018 Sept. 28, 2019 Sept. 29, 2018 Interest expense $ 40,721 $ 44,789 $ 119,736 $ 120,308 Interest income (9,435 ) (7,588 ) (26,977 ) (16,542 ) Interest expense, net $ 31,286 $ 37,201 $ 92,759 $ 103,766

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 28, 2019
Federal Home Loan Banks [Abstract]
Schedule Of Changes In Stock Holders Equity	The following tables reflect the changes in stockholders’ equity attributable to both Nucor and the noncontrolling interests of Nucor’s joint ventures, primarily Nucor-Yamato Steel Company (Limited Partnership) of which Nucor owns 51% Three Months (13 Weeks) Ended September 28, 2019 Accumulated Total Additional Other Treasury Stock Nucor Common Stock Paid-in Retained Comprehensive (at cost) Stockholders' Noncontrolling Total Shares Amount Capital Earnings Income (Loss) Shares Amount Equity Interests BALANCES, June 29, 2019 $ 10,698,008 380,154 $ 152,061 $ 2,098,809 $ 10,977,950 $ (297,760 ) 76,997 $ (2,630,343 ) $ 10,300,717 $ 397,291 Net earnings 293,587 - - - 275,031 - - - 275,031 18,556 Other comprehensive income (loss) (16,006 ) - - - - (16,006 ) - - (16,006 ) - Stock options exercised - - - - - - - - - - Stock option expense 275 - - 275 - - - - 275 - Issuance of stock under award plans, net of forfeitures 11,339 - - 9,365 - - (58 ) 1,974 11,339 - Amortization of unearned compensation 500 - - 500 - - - - 500 - Treasury stock acquired - - - - - - - - - - Cash dividends declared (122,809 ) - - - (122,809 ) - - - (122,809 ) - Distributions to noncontrolling interests (3,861 ) - - - - - - - - (3,861 ) Other - - - (1 ) - - - 1 - - BALANCES, September 28, 2019 $ 10,861,033 380,154 $ 152,061 $ 2,108,948 $ 11,130,172 $ (313,766 ) 76,939 $ (2,628,368 ) $ 10,449,047 $ 411,986 Nine Months (39 Weeks) Ended September 28, 2019 Accumulated Total Additional Other Treasury Stock Nucor Common Stock Paid-in Retained Comprehensive (at cost) Stockholders' Noncontrolling Total Shares Amount Capital Earnings Income (Loss) Shares Amount Equity Interests BALANCES, December 31, 2018 $ 10,201,968 380,154 $ 152,061 $ 2,073,715 $ 10,337,445 $ (304,133 ) 74,562 $ (2,467,010 ) $ 9,792,078 $ 409,890 Net earnings 1,236,657 - - - 1,163,320 - - - 1,163,320 73,337 Other comprehensive income (loss) (11,519 ) - - - - (11,519 ) - - (11,519 ) - Stock options exercised 5,892 - - 808 - - (153 ) 5,084 5,892 - Stock option expense 4,387 - - 4,387 - - - - 4,387 - Issuance of stock under award plans, net of forfeitures 59,608 - - 28,540 - - (920 ) 31,068 59,608 - Amortization of unearned compensation 1,500 - - 1,500 - - - - 1,500 - Treasury stock acquired (197,511 ) - - - - - 3,450 (197,511 ) (197,511 ) - Cash dividends declared (368,707 ) - - - (368,707 ) - - - (368,707 ) - Distributions to noncontrolling interests (71,241 ) - - - - - - - - (71,241 ) Other (1 ) - - (2 ) (1,886 ) 1,886 - 1 (1 ) - BALANCES, September 28, 2019 $ 10,861,033 380,154 $ 152,061 $ 2,108,948 $ 11,130,172 $ (313,766 ) 76,939 $ (2,628,368 ) $ 10,449,047 $ 411,986 Three Months (13 Weeks) Ended September 29, 2018 Accumulated Total Additional Other Treasury Stock Nucor Common Stock Paid-in Retained Comprehensive (at cost) Stockholders' Noncontrolling Total Shares Amount Capital Earnings Income (Loss) Shares Amount Equity Interests BALANCES, June 30, 2018 $ 9,735,424 380,154 $ 152,061 $ 2,051,383 $ 9,257,822 $ (296,032 ) 63,810 $ (1,791,827 ) $ 9,373,407 $ 362,017 Net earnings 706,287 - - - 676,656 - - - 676,656 29,631 Other comprehensive income (loss) 21,425 - - - - 21,425 - - 21,425 - Stock options exercised 11,822 - - 4,572 - - (256 ) 7,250 11,822 - Stock option expense 312 - - 312 - - - - 312 - Issuance of stock under award plans, net of forfeitures 9,598 - - 8,633 - - (34 ) 965 9,598 - Amortization of unearned compensation 400 - - 400 - - - - 400 - Treasury stock acquired (181,077 ) - - - - - 2,701 (181,077 ) (181,077 ) - Cash dividends declared (120,406 ) - - - (120,406 ) - - - (120,406 ) - Distributions to noncontrolling interests (9,364 ) - - - - - - - - (9,364 ) Other - - - (1 ) 1 - - - - - BALANCES, September 29, 2018 $ 10,174,421 380,154 $ 152,061 $ 2,065,299 $ 9,814,073 $ (274,607 ) 66,221 $ (1,964,689 ) $ 9,792,137 $ 382,284 Nine Months (39 Weeks) Ended September 29, 2018 Accumulated Total Additional Other Treasury Stock Nucor Common Stock Paid-in Retained Comprehensive (at cost) Stockholders' Noncontrolling Total Shares Amount Capital Earnings Income (Loss) Shares Amount Equity Interests BALANCES, December 31, 2017 $ 9,084,788 379,900 $ 151,960 $ 2,021,339 $ 8,463,709 $ (254,681 ) 61,931 $ (1,643,291 ) $ 8,739,036 $ 345,752 Net earnings 1,800,014 - - - 1,713,988 - - - 1,713,988 86,026 Other comprehensive income (loss) (19,926 ) - - - - (19,926 ) - - (19,926 ) - Stock options exercised 24,102 210 84 14,675 - - (334 ) 9,343 24,102 - Stock option expense 4,249 - - 4,249 - - - - 4,249 - Issuance of stock under award plans, net of forfeitures 44,304 44 17 23,636 - - (754 ) 20,651 44,304 - Amortization of unearned compensation 1,400 - - 1,400 - - - - 1,400 - Treasury stock acquired (351,392 ) - - - - - 5,378 (351,392 ) (351,392 ) - Cash dividends declared (363,624 ) - - - (363,624 ) - - - (363,624 ) - Distributions to noncontrolling interests (49,494 ) - - - - - - - - (49,494 ) BALANCES, September 29, 2018 $ 10,174,421 380,154 $ 152,061 $ 2,065,299 $ 9,814,073 $ (274,607 ) 66,221 $ (1,964,689 ) $ 9,792,137 $ 382,284

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 28, 2019
Equity [Abstract]
Components of Accumulated Other Comprehensive Income (Loss)	The following tables reflect the changes in accumulated other comprehensive income (loss) by component for the three- and nine-month periods ended September 28, 2019 and September 29, 2018 (in thousands): Three-Month (13-Week) Period Ended September 28, 2019 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive income (loss) at June 29, 2019 $ (11,100 ) $ (295,559 ) $ 8,899 $ (297,760 ) Other comprehensive income (loss) before reclassifications (3,315 ) (14,306 ) - (17,621 ) Amounts reclassified from accumulated other comprehensive income (loss) into earnings (1) 1,615 - - 1,615 Net current-period other comprehensive income (loss) (1,700 ) (14,306 ) - (16,006 ) Accumulated other comprehensive income (loss) at September 28, 2019 $ (12,800 ) $ (309,865 ) $ 8,899 $ (313,766 ) Nine-Month (39-Week) Period Ended September 28, 2019 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive income (loss) at December 31, 2018 $ (6,500 ) $ (304,646 ) $ 7,013 $ (304,133 ) Other comprehensive income (loss) before reclassifications (7,801 ) (5,219 ) - (13,020 ) Amounts reclassified from accumulated other comprehensive income (loss) into earnings (1) 1,501 - - 1,501 Net current-period other comprehensive income (loss) (6,300 ) (5,219 ) - (11,519 ) Other - - 1,886 1,886 Accumulated other comprehensive income (loss) at September 28, 2019 $ (12,800 ) $ (309,865 ) $ 8,899 $ (313,766 ) ( 1) 2019 2019 Three-Month (13-Week) Period Ended September 29, 2018 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive income (loss) at June 30, 2018 $ (6,800 ) $ (294,864 ) $ 5,632 $ (296,032 ) Other comprehensive income (loss) before reclassifications (1,393 ) 22,625 - 21,232 Amounts reclassified from accumulated other comprehensive income (loss) into earnings (2) 193 - - 193 Net current-period other comprehensive income (loss) (1,200 ) 22,625 - 21,425 Accumulated other comprehensive income (loss) at September 29, 2018 $ (8,000 ) $ (272,239 ) $ 5,632 $ (274,607 ) Nine-Month (39-Week) Period Ended September 29, 2018 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive income (loss) at December 31, 2017 $ (2,800 ) $ (257,513 ) $ 5,632 $ (254,681 ) Other comprehensive income (loss) before reclassifications (5,792 ) (14,726 ) - (20,518 ) Amounts reclassified from accumulated other comprehensive income (loss) into earnings (2) 592 - - 592 Net current-period other comprehensive income (loss) (5,200 ) (14,726 ) - (19,926 ) Accumulated other comprehensive income (loss) at September 29, 2018 $ (8,000 ) $ (272,239 ) $ 5,632 $ (274,607 ) (2) Includes $ 193 and $ 592 of accumulated other comprehensive income (loss) reclassifications into cost of products sold for net losses on commodity contracts in the third quarter and first nine months of 2018 , respectively. The tax impact of those reclassifications w as $ 100 and $ 200 in the third quarter and first nine months of 2018 , respectively .

Segments (Tables)

Segments (Tables)	9 Months Ended
	Sep. 28, 2019
Segment Reporting [Abstract]
Segments	Nucor’s results by segment for the third quarter and first nine months of 2019 and 2018 were as follows (in thousands): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 28, 2019 Sept. 29, 2018 Sept. 28, 2019 Sept. 29, 2018 Net sales to external customers: Steel mills $ 3,244,473 $ 4,401,610 $ 10,897,322 $ 12,151,843 Steel products 1,820,359 1,849,218 5,225,064 5,056,299 Raw materials 399,670 491,374 1,334,726 1,563,253 $ 5,464,502 $ 6,742,202 $ 17,457,112 $ 18,771,395 Intercompany sales: Steel mills $ 825,237 $ 1,055,093 $ 2,542,008 $ 3,019,199 Steel products 57,517 56,185 174,718 142,862 Raw materials 2,063,167 2,923,196 6,917,523 8,687,408 Corporate/eliminations (2,945,921 ) (4,034,474 ) (9,634,249 ) (11,849,469 ) $ - $ - $ - $ - Earnings (loss) before income taxes and noncontrolling interests: Steel mills $ 309,939 $ 1,095,360 $ 1,578,257 $ 2,617,647 Steel products 170,214 138,688 363,731 380,268 Raw materials (10,599 ) (29,074 ) 64,333 180,468 Corporate/eliminations (89,215 ) (282,472 ) (401,744 ) (826,268 ) $ 380,339 $ 922,502 $ 1,604,577 $ 2,352,115 Sept. 28, 2019 Dec. 31, 2018 Segment assets: Steel mills $ 9,117,610 $ 9,244,086 Steel products 4,730,410 4,734,636 Raw materials 3,225,367 3,492,126 Corporate/eliminations 1,432,878 449,740 $ 18,506,265 $ 17,920,588

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 28, 2019
Revenue From Contract With Customer [Abstract]
Schedule of Net Sales Disaggregates by Major Source	The following tables disaggregate our revenue by major source for the third quarter and first nine months of 2019 and 2018 (in thousands): Three Months (13 Weeks) Ended September 28, 2019 Nine Months (39 Weeks) Ended September 28, 2019 Steel Mills Steel Products Raw Materials Total Steel Mills Steel Products Raw Materials Total Sheet $ 1,513,884 $ - $ - $ 1,513,884 $ 5,071,027 $ - $ - $ 5,071,027 Bar 979,082 - - 979,082 3,173,289 - - 3,173,289 Structural 378,670 - - 378,670 1,214,355 - - 1,214,355 Plate 372,837 - - 372,837 1,438,651 - - 1,438,651 Tubular Products - 296,519 - 296,519 - 919,711 - 919,711 Rebar Fabrication - 469,180 - 469,180 - 1,249,912 - 1,249,912 Other Steel Products - 1,054,660 - 1,054,660 - 3,055,441 - 3,055,441 Raw Materials - - 399,670 399,670 - - 1,334,726 1,334,726 $ 3,244,473 $ 1,820,359 $ 399,670 $ 5,464,502 $ 10,897,322 $ 5,225,064 $ 1,334,726 $ 17,457,112 Three Months (13 Weeks) Ended September 29, 2018 Nine Months (39 Weeks) Ended September 29, 2018 Steel Mills Steel Products Raw Materials Total Steel Mills Steel Products Raw Materials Total Sheet $ 2,051,634 $ - $ - $ 2,051,634 $ 5,692,281 $ - $ - $ 5,692,281 Bar 1,243,890 - - 1,243,890 3,592,475 - - 3,592,475 Structural 503,733 - - 503,733 1,348,987 - - 1,348,987 Plate 602,353 - - 602,353 1,518,100 - - 1,518,100 Tubular Products - 357,815 - 357,815 - 1,040,611 - 1,040,611 Rebar Fabrication - 412,977 - 412,977 - 1,133,117 - 1,133,117 Other Steel Products - 1,078,426 - 1,078,426 - 2,882,571 - 2,882,571 Raw Materials - - 491,374 491,374 - - 1,563,253 1,563,253 $ 4,401,610 $ 1,849,218 $ 491,374 $ 6,742,202 $ 12,151,843 $ 5,056,299 $ 1,563,253 $ 18,771,395

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 28, 2019
Earnings Per Share [Abstract]
Computations of Basic and Diluted Net Earnings Per Share	The computations of basic and diluted net earnings per share for the third quarter and first nine months of 2019 and 2018 are as follows (in thousands, except per share amounts): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 28, 2019 Sept. 29, 2018 Sept. 28, 2019 Sept. 29, 2018 Basic net earnings per share: Basic net earnings $ 275,031 $ 676,656 $ 1,163,320 $ 1,713,988 Earnings allocated to participating securities (1,655 ) (2,807 ) (6,295 ) (6,707 ) Net earnings available to common stockholders $ 273,376 $ 673,849 $ 1,157,025 $ 1,707,281 Average shares outstanding 304,637 315,913 305,553 317,928 Basic net earnings per share $ 0.90 $ 2.13 $ 3.79 $ 5.37 Diluted net earnings per share: Diluted net earnings $ 275,031 $ 676,656 $ 1,163,320 $ 1,713,988 Earnings allocated to participating securities (1,656 ) (2,796 ) (6,295 ) (6,684 ) Net earnings available to common stockholders $ 273,375 $ 673,860 $ 1,157,025 $ 1,707,304 Diluted average shares outstanding: Basic shares outstanding 304,637 315,913 305,553 317,928 Dilutive effect of stock options and other 343 885 476 954 304,980 316,798 306,029 318,882 Diluted net earnings per share $ 0.90 $ 2.13 $ 3.78 $ 5.35
Anti-dilutive Stock Options	The following stock options were excluded from the computation of diluted net earnings per share for the third quarter and first nine months of 2019 and 2018 because their effect would have been anti-dilutive (shares in thousands): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 28, 2019 Sept. 29, 2018 Sept. 28, 2019 Sept. 29, 2018 Anti-dilutive stock options: Weighted-average shares 963 265 963 89 Weighted-average exercise price $ 60.92 $ 65.80 $ 60.92 $ 65.80

Basis of Interim Presentation -

Basis of Interim Presentation - Additional Information (Detail)	Jan. 01, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Adoption Of New Accounting Standard Increase Decrease In Total Assets	0.50%
Adoption Of New Accounting Standard Increase Decrease In Total Liabilities	1.20%

Inventories - Additional Inform

Inventories - Additional Information (Detail)	Sep. 28, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Raw materials and supplies in inventory, percentage	43.00%	43.00%
Finished and semi-finished products in inventory, percentage	57.00%	57.00%

Property, Plant and Equipment -

Property, Plant and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 29, 2018	Sep. 29, 2018	Sep. 28, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Accumulated depreciation			$ 9,540,000	$ 9,190,000
Property, plant and equipment, net			5,886,730	5,334,748
Impairment of assets	$ 110,000	$ 110,000
Carrying Value of Two Field of Wells [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net			68,000	71,000
Impairment of assets	$ 110,000
Carrying Value of Third Field of Wells [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net			$ 48,300	$ 51,800

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 28, 2019	Dec. 31, 2018
Disclosure of Leases [Line Items]
Operating lease, renewal term	can extend the lease term from one to five years or more.
Weighted-average discount rate - finance leases	30.80%
Capital leases, future minimum payments due		$ 154.8
Capital leases, future minimum payments due, next twelve months		17.7
Capital leases future minimum payments due in second third years		33.6
Capital leases future minimum payments due in fourth fifth years		30
Capital leases, future minimum payments due thereafter		73.4
Operating leases, future minimum payments due		128.6
Operating leases, future minimum payments due, next twelve months		31.8
Operating leases future minimum payments due in second third years		45
Operating leases future minimum payments due in fourth fifth years		28.4
Operating leases, future minimum payments, due thereafter		23.5
Capital leased assets, gross		$ 89.4
Minimum [Member]
Disclosure of Leases [Line Items]
Operating lease, renewal period	1 year
Maximum [Member]
Disclosure of Leases [Line Items]
Operating lease, renewal period	5 years

Leases - Quantitative data rela

Leases - Quantitative data related to our leases (Detail) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 28, 2019USD ($)	Sep. 28, 2019USD ($)
Disclosure of Leases [Line Items]
Operating lease cost	$ 5,922	$ 17,647
Finance lease cost:
Total finance lease cost	5,165	15,505
Total lease cost	11,087	33,152
Cash paid for amounts included in measurement of lease liabilities:
Operating cash flows from operating leases		16,766
Operating cash flows from finance leases		8,451
Financing cash flows from finance leases		6,538
Assets
Total leased assets	159,576	159,576
Liabilities
Total leased liabilities	$ 174,867	$ 174,867
Weighted-average remaining lease term - operating leases	9 years 3 months 18 days	9 years 3 months 18 days
Weighted-average remaining lease term - finance leases	10 years 3 months 18 days	10 years 3 months 18 days
Weighted-average discount rate - operating leases	3.80%	3.80%
Weighted-average discount rate - finance leases	30.80%	30.80%
Maturity Of Lease Liabilities [Abstract]
2019	$ 5,957	$ 5,957
2020	19,223	19,223
2021	16,853	16,853
2022	15,248	15,248
2023	12,161	12,161
Thereafter	44,265	44,265
Total lease payments	113,707	113,707
Less imputed interest	(20,491)	(20,491)
Present value of lease liabilities	93,216	93,216
2019	4,904	4,904
2020	19,307	19,307
2021	18,833	18,833
2022	18,038	18,038
2023	16,194	16,194
Thereafter	79,529	79,529
Total lease payments	156,805	156,805
Less imputed interest	(75,154)	(75,154)
Present value of lease liabilities	81,651	81,651
Other Assets
Assets
Operating lease assets	92,022	92,022
Accrued Expenses and Other Current Liabilities
Liabilities
Current operating	17,362	17,362
Current Portion of Long-term Debt and Finance Lease Obligations
Liabilities
Current finance	8,878	8,878
Deferred Credits and Other Liabilities
Liabilities
Non-current operating	75,854	75,854
Long-term Debt and Finance Lease Obligations Due After One Year
Liabilities
Non-current finance	72,773	72,773
Property, Plant and Equipment, Net
Assets
Finance lease assets	67,554	67,554
Cost of Products Sold
Disclosure of Leases [Line Items]
Operating lease cost	4,932	16,075
Finance lease cost:
Amortization of leased assets	2,377	7,054
Marketing, Administrative and Other Expenses
Disclosure of Leases [Line Items]
Operating lease cost	990	1,572
Interest Expense, Net
Finance lease cost:
Interest on lease liabilities	$ 2,788	$ 8,451

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Schedule of Change in Net Carrying Amount of Goodwill by Segment (Detail) $ in Thousands	9 Months Ended
	Sep. 28, 2019USD ($)
Goodwill [Line Items]
Balance, beginning of period	$ 2,184,336
Translation	2,163
Balance, end of period	2,186,499
Steel Mills [Member]
Goodwill [Line Items]
Balance, beginning of period	591,986
Translation	0
Balance, end of period	591,986
Steel Products [Member]
Goodwill [Line Items]
Balance, beginning of period	862,773
Translation	2,163
Balance, end of period	864,936
Raw Materials [Member]
Goodwill [Line Items]
Balance, beginning of period	729,577
Translation	0
Balance, end of period	$ 729,577

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018	Dec. 31, 2018
Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	$ 2,186,499		$ 2,186,499		$ 2,184,336
Finite-lived intangible assets	764,267		764,267		828,504
Intangible asset amortization expense	22,000	$ 22,100	64,700	$ 66,700
Future amortization expense, in 2019	87,100		87,100
Future amortization expense, in 2020	84,700		84,700
Future amortization expense, in 2021	83,500		83,500
Future amortization expense, in 2022	81,200		81,200
Future amortization expense, in 2023	80,000		$ 80,000
Minimum [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, useful life			5 years
Maximum [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, useful life			22 years
Rebar Fabrication [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Percentage of fair value exceeded carrying value			8.00%
Goodwill	354,900		$ 354,900		353,000
Finite-lived intangible assets	69,400		$ 69,400		$ 76,700
Grating unit [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Percentage of fair value exceeded carrying value			17.00%
Goodwill	36,700		$ 36,700
Finite-lived intangible assets	$ 3,300		$ 3,300

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	Sep. 28, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	$ 1,662,534	$ 1,662,116
Intangible assets, Accumulated Amortization	898,267	833,612
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	1,421,107	1,418,250
Intangible assets, Accumulated Amortization	767,027	713,656
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	177,620	176,046
Intangible assets, Accumulated Amortization	95,450	87,680
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	63,807	67,820
Intangible assets, Accumulated Amortization	$ 35,790	$ 32,276

Equity Investments - Additional

Equity Investments - Additional Information (Detail) € in Millions	Jul. 26, 2019USD ($)	Sep. 28, 2019USD ($)	Sep. 29, 2018USD ($)	Sep. 28, 2019USD ($)Sheet	Sep. 29, 2018USD ($)	Sep. 28, 2019EUR (€)	Jan. 16, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2018EUR (€)
Schedule Of Equity Method Investments [Line Items]
Equity method investments		$ 826,100,000		$ 826,100,000				$ 869,900,000
Amortization				64,655,000	$ 66,684,000
NuMit LLC [Member]
Schedule Of Equity Method Investments [Line Items]
Equity method investments		$ 323,900,000		$ 323,900,000				337,200,000
Equity method investment, ownership percentage		50.00%		50.00%		50.00%
Period used for lag basis, in months				1 month
Distributions from affiliates				$ 27,400,000	28,300,000
Steel Technologies LLC [Member]
Schedule Of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		100.00%		100.00%		100.00%
Number of sheet processing facilities operated by Steel Technologies | Sheet				26
Duferdofin Nucor S.r.l. [Member]
Schedule Of Equity Method Investments [Line Items]
Equity method investments		$ 256,000,000		$ 256,000,000				269,100,000
Equity method investment, ownership percentage		50.00%		50.00%		50.00%
Period used for lag basis, in months				1 month
Equity method investments, share of net assets		$ 107,000,000		$ 107,000,000
Basis difference due to the step-up to fair value of certain assets and liabilities		149,000,000		149,000,000
Step-up to fair value of equity method investment, portion related to identification of goodwill				84,300,000
Amortization		2,200,000	$ 2,300,000	6,700,000	$ 7,100,000
Due from related parties, noncurrent		38,300,000		$ 38,300,000		€ 35		40,200,000	€ 35
Interest rate per year in excess of Euribor as of date of the notes				0.75%
Equity method investments notes payable with parent company, maturity date				Jan. 31, 2022
Duferdofin Nucor S.r.l. [Member] | Facility A [Member]
Schedule Of Equity Method Investments [Line Items]
Equity method investments credit facilities subject to guarantee, amount		175,100,000		$ 175,100,000		160
Total amount outstanding under equity method investments credit facilities		$ 168,500,000		$ 168,500,000		€ 154		178,000,000	€ 155
Guarantor obligation percentage of exposure in case of default		50.00%		50.00%		50.00%
Line of credit facility, maturity period				Apr. 16, 2021
Nucor-JFE [Member]
Schedule Of Equity Method Investments [Line Items]
Equity method investments		$ 150,100,000		$ 150,100,000				$ 135,700,000
Equity method investment, ownership percentage		50.00%		50.00%		50.00%	50.00%
Nucor-JFE [Member] | General Financing Agreement and Promissory Note [Member]
Schedule Of Equity Method Investments [Line Items]
Equity method investments credit facilities subject to guarantee, amount							$ 65,000,000
Total amount outstanding under equity method investments credit facilities		$ 30,000,000		$ 30,000,000
Guarantor obligation percentage of exposure in case of default		50.00%		50.00%		50.00%
Nucor-JFE [Member] | Uncommitted Loan Facility and Promissory Note [Member]
Schedule Of Equity Method Investments [Line Items]
Guarantee of debt	$ 17,500,000
Guarantee of debt, plus interest and fees	$ 20,000,000
Equity method investments credit facilities, maturity date	Jul. 31, 2024
Equity method investments credit facilities, amount	$ 35,000,000

Current Liabilities - Additiona

Current Liabilities - Additional Information (Detail) - USD ($) $ in Millions	Sep. 28, 2019	Dec. 31, 2018
Liabilities Current [Abstract]
Book overdrafts	$ 161.5	$ 89.8
Dividends payable, current	$ 122.8	$ 123.4

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 28, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments	$ 249,616
Total assets	18,506,265	$ 17,920,588
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	1,445,116	1,084,319
Short-term investments	249,616
Derivative contracts	2,228	4,772
Total assets	1,696,960	1,089,091
Derivative contracts	(16,800)	(8,600)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	1,445,116	1,084,319
Short-term investments	249,616
Derivative contracts	0	0
Total assets	1,694,732	1,084,319
Derivative contracts	0	0
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0	0
Short-term investments	0
Derivative contracts	2,228	4,772
Total assets	2,228	4,772
Derivative contracts	(16,800)	(8,600)
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0	0
Short-term investments	0
Derivative contracts	0	0
Total assets	0	0
Derivative contracts	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	Sep. 28, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair value of short-term and long-term debt, including current maturities	$ 4,830	$ 4,450

Contingencies - Additional Info

Contingencies - Additional Information (Detail) - USD ($) $ in Millions	Sep. 28, 2019	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Accrual for environmental loss contingencies, gross	$ 17.1	$ 18.4
Accrued environmental loss contingencies, current	4.7	7
Accrued environmental loss contingencies, noncurrent	$ 12.4	$ 11.4

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018	May 08, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance	1.5		1.5
Stock options exercise prices as percentage of the market value on the date of the grant			100.00%
Compensation expenses for stock options	$ 0.3	$ 0.3	$ 4.4	$ 4.3
Omnibus Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, common stock available for grant	3.6		3.6
Omnibus Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, common stock available for grant					13
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period			3 years
Stock options term, years			10 years
Unrecognized compensation expense related to stock	$ 1.5		$ 1.5
Weighted-average recognition period for unrecognized compensation expense related to stock (years)			1 year 9 months 18 days
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock	70.2		$ 70.2
Weighted-average recognition period for unrecognized compensation expense related to stock (years)			1 year 8 months 12 days
Compensation expense	11	8.5	$ 59.1	46.8
Restricted Stock Units [Member] | LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Eligible age of officer for restricted stock award			55 years
Restricted Stock Units [Member] | AIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Eligible age of officer for restricted stock award			55 years
Additional common stock units for election of deferred annual incentive award, percentage			25.00%
Restricted Stock Awards and Units [Member] | AIP and LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock	2.1		$ 2.1
Weighted-average recognition period for unrecognized compensation expense related to stock (years)			1 year 8 months 12 days
Compensation expense	$ 1.8	$ 4.9	$ 10.9	$ 14.6

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Stock Option Plans Activity (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 28, 2019USD ($)$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Outstanding at beginning of year, Shares | shares	3,828
Granted, Shares | shares	489
Exercised, Shares | shares	(153)
Outstanding at end of year, Shares | shares	4,164
Options exercisable at end of year, Shares | shares	2,914
Outstanding at beginning of year, Weighted - Average Exercise Price | $ / shares	$ 49.71
Granted, Weighted - Average Exercise Price | $ / shares	48
Exercised, Weighted - Average Exercise Price | $ / shares	38.56
Outstanding at end of period, Weighted - Average Exercise Price | $ / shares	49.92
Options exercisable at end of year, Weighted - Average Exercise Price | $ / shares	$ 47.13
Outstanding, Weighted - Average Remaining Contractual Life	5 years 10 months 24 days
Stock options exercisable, Weighted - Average Remaining Contractual Life	4 years 8 months 12 days
Exercised, Aggregate Intrinsic Value | $	$ 3,058
Outstanding at end of year, Aggregate Intrinsic Value | $	11,151
Stock options exercisable, Aggregate Intrinsic Value | $	$ 10,283

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Nucor's RSU Activity (Detail) - Restricted Stock Units [Member] shares in Thousands	9 Months Ended
	Sep. 28, 2019$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested at beginning of year, Shares | shares	1,246
Granted, Shares | shares	1,770
Vested, Shares | shares	(1,177)
Canceled, Shares | shares	(29)
Unvested at end of year, Shares | shares	1,810
Unvested at beginning of year, Grant Date Fair Value | $ / shares	$ 59.09
Granted, Grant Date Fair Value | $ / shares	48
Vested, Grant Date Fair Value | $ / shares	52.39
Canceled, Grant Date Fair Value | $ / shares	57.53
Unvested at end of year, Grant Date Fair Value | $ / shares	$ 52.62

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Nucor's Restricted Stock Activity under AIP and LTIP (Detail) - Restricted Stock Units and Restricted Stock Awards [Member] shares in Thousands	9 Months Ended
	Sep. 28, 2019$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested at beginning of year, Shares | shares	130
Granted, Shares | shares	316
Vested, Shares | shares	(296)
Unvested at end of year, Shares | shares	150
Unvested at beginning of year, Grant Date Fair Value | $ / shares	$ 62.97
Granted, Grant Date Fair Value | $ / shares	58.04
Vested, Grant Date Fair Value | $ / shares	58.78
Unvested at end of year, Grant Date Fair Value | $ / shares	$ 60.84

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Employee Benefit Plan [Abstract]
Profit Sharing and Retirement Savings Plan, plan expense	$ 40	$ 86.4	$ 163.7	$ 226.5

Interest Expense (Income) - Sch

Interest Expense (Income) - Schedule of Components of Net Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Interest Revenue Or Expense Net [Abstract]
Interest expense	$ 40,721	$ 44,789	$ 119,736	$ 120,308
Interest income	(9,435)	(7,588)	(26,977)	(16,542)
Interest expense, net	$ 31,286	$ 37,201	$ 92,759	$ 103,766

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Effective income tax rate	22.80%	23.40%
Non-current deferred tax liabilities included in deferred credits and other liabilities	$ 407		$ 332
Non-current deferred tax assets included in other assets	$ 0.9		$ 0.7

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Billions	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Common Stock, Dividends, Per Share, Declared	$ 0.40	$ 0.38	$ 1.20	$ 1.14
Common Stock [Member]
Stock Repurchase Program, Authorized Amount	$ 2		$ 2
Share repurchase program, available repurchase amount	$ 1.3		$ 1.3
Nucor Yamato Steel Company [Member]
Noncontrolling Interest, Ownership Percentage by Parent	51.00%	51.00%	51.00%	51.00%

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Change in Stockholder's Equity (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
BALANCES, beginning of period	$ 10,698,008	$ 9,735,424	$ 10,201,968	$ 9,084,788
Net earnings	293,587	706,287	1,236,657	1,800,014
Other comprehensive income (loss)	(16,006)	21,425	(11,519)	(19,926)
Stock options exercised		11,822	$ 5,892	24,102
Stock options exercised (in shares)			153
Stock option expense	275	312	$ 4,387	4,249
Issuance of stock under award plans, net of forfeitures	11,339	9,598	59,608	44,304
Amortization of unearned compensation	500	400	1,500	1,400
Treasury stock value acquired		(181,077)	(197,511)	(351,392)
Cash dividends declared	(122,809)	(120,406)	(368,707)	(363,624)
Distributions to noncontrolling interests	(3,861)	(9,364)	(71,241)	(49,494)
Other			(1)
BALANCES, end of period	10,861,033	10,174,421	10,861,033	10,174,421
Common Stock [Member]
BALANCES, beginning of period	$ 152,061	$ 152,061	$ 152,061	$ 151,960
BALANCES, shares at beginning of period	380,154	380,154	380,154	379,900
Stock options exercised				$ 84
Stock options exercised (in shares)				210
Issuance of stock under award plans, net of forfeitures				$ 17
Issuance of stock under award plans, net of forfeitures, shares				44
BALANCES, end of period	$ 152,061	$ 152,061	$ 152,061	$ 152,061
BALANCES, shares at end of period	380,154	380,154	380,154	380,154
Additional Paid-in Capital [Member]
BALANCES, beginning of period	$ 2,098,809	$ 2,051,383	$ 2,073,715	$ 2,021,339
Stock options exercised		4,572	808	14,675
Stock option expense	275	312	4,387	4,249
Issuance of stock under award plans, net of forfeitures	9,365	8,633	28,540	23,636
Amortization of unearned compensation	500	400	1,500	1,400
Other	(1)	(1)	(2)
BALANCES, end of period	2,108,948	2,065,299	2,108,948	2,065,299
Retained Earnings [Member]
BALANCES, beginning of period	10,977,950	9,257,822	10,337,445	8,463,709
Net earnings	275,031	676,656	1,163,320	1,713,988
Cash dividends declared	(122,809)	(120,406)	(368,707)	(363,624)
Other		1	(1,886)
BALANCES, end of period	11,130,172	9,814,073	11,130,172	9,814,073
Accumulated Other Comprehensive Loss [Member]
BALANCES, beginning of period	(297,760)	(296,032)	(304,133)	(254,681)
Other comprehensive income (loss)	(16,006)	21,425	(11,519)	(19,926)
Other			1,886
BALANCES, end of period	(313,766)	(274,607)	(313,766)	(274,607)
Treasury Stock [Member]
BALANCES, beginning of period	$ (2,630,343)	$ (1,791,827)	$ (2,467,010)	$ (1,643,291)
BALANCES, shares at beginning of period	76,997	63,810	74,562	61,931
Stock options exercised		$ 7,250	$ 5,084	$ 9,343
Stock options exercised (in shares)		(256)	(153)	(334)
Issuance of stock under award plans, net of forfeitures	$ 1,974	$ 965	$ 31,068	$ 20,651
Issuance of stock under award plans, net of forfeitures, shares	(58)	(34)	(920)	(754)
Treasury stock value acquired		$ (181,077)	$ (197,511)	$ (351,392)
Treasury stock acquired (in shares)		2,701	3,450	5,378
Other	$ 1		$ 1
BALANCES, end of period	$ (2,628,368)	$ (1,964,689)	$ (2,628,368)	$ (1,964,689)
BALANCES, shares at end of period	76,939	66,221	76,939	66,221
Total Nucor Stockholders' Equity [Member]
BALANCES, beginning of period	$ 10,300,717	$ 9,373,407	$ 9,792,078	$ 8,739,036
Net earnings	275,031	676,656	1,163,320	1,713,988
Other comprehensive income (loss)	(16,006)	21,425	(11,519)	(19,926)
Stock options exercised		11,822	5,892	24,102
Stock option expense	275	312	4,387	4,249
Issuance of stock under award plans, net of forfeitures	11,339	9,598	59,608	44,304
Amortization of unearned compensation	500	400	1,500	1,400
Treasury stock value acquired		(181,077)	(197,511)	(351,392)
Cash dividends declared	(122,809)	(120,406)	(368,707)	(363,624)
Other			(1)
BALANCES, end of period	10,449,047	9,792,137	10,449,047	9,792,137
Noncontrolling Interest [Member]
BALANCES, beginning of period	397,291	362,017	409,890	345,752
Net earnings	18,556	29,631	73,337	86,026
Distributions to noncontrolling interests	(3,861)	(9,364)	(71,241)	(49,494)
BALANCES, end of period	$ 411,986	$ 382,284	$ 411,986	$ 382,284

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 28, 2019		Sep. 29, 2018		Sep. 28, 2019		Sep. 29, 2018
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Beginning Balance, Gains and Losses on Hedging Derivatives	$ (11,100)		$ (6,800)		$ (6,500)		$ (2,800)
Other comprehensive income (loss) before reclassifications, Gains and Losses on Hedging Derivatives	(3,315)		(1,393)		(7,801)		(5,792)
Amounts reclassified from accumulated other comprehensive (loss) income into earnings, Gains and Losses on Hedging Derivatives	1,615	[1]	193	[2]	1,501	[1]	592	[2]
Net current-period other comprehensive income (loss), Gains and Losses on Hedging Derivatives	(1,700)		(1,200)		(6,300)		(5,200)
Ending Balance, Gains and Losses on Hedging Derivatives	(12,800)		(8,000)		(12,800)		(8,000)
Beginning Balance, Foreign Currency Gains (Losses)	(295,559)		(294,864)		(304,646)		(257,513)
Other comprehensive income (loss) before reclassifications, Foreign Currency Gains (Losses)	(14,306)		22,625		(5,219)		(14,726)
Net current-period other comprehensive income (loss), Foreign Currency Gains (Losses)	(14,306)		22,625		(5,219)		(14,726)
Ending Balance, Foreign Currency Gains (Losses)	(309,865)		(272,239)		(309,865)		(272,239)
Beginning Balance, Adjustment to Early Retiree Medical Plan	8,899		5,632		7,013		5,632
Accumulated other comprehensive income loss defined benefit pension and other postretirement plans other net of tax					1,886
Ending Balance, Adjustment to Early Retiree Medical Plan	8,899		5,632		8,899		5,632
Beginning Balance	(297,760)		(296,032)		(304,133)		(254,681)
Other comprehensive income (loss) before reclassifications	(17,621)		21,232		(13,020)		(20,518)
Amounts reclassified from accumulated other comprehensive income (loss) into earnings	1,615	[1]	193	[2]	1,501	[1]	592	[2]
Net current-period other comprehensive income (loss)	(16,006)		21,425		(11,519)		(19,926)
Accumulated other comprehensive income loss other net of tax					1,886
Ending Balance	$ (313,766)		$ (274,607)		$ (313,766)		$ (274,607)
[1]	Includes $1,615 and $1,501 of accumulated other comprehensive income (loss) reclassifications into cost of products sold for net losses on commodity contracts in the third quarter and first nine months of 2019 2019
[2]	Includes $ 193 and $ 592 of accumulated other comprehensive income (loss) reclassifications into cost of products sold for net losses on commodity contracts in the third quarter and first nine months of 2018 , respectively. The tax impact of those reclassifications w as $ 100 and $ 200 in the third quarter and first nine months of 2018 , respectively .

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income (Loss) (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 28, 2019		Sep. 29, 2018		Sep. 28, 2019		Sep. 29, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive (loss) income into earnings, Gains and Losses on Hedging Derivatives	$ 1,615	[1]	$ 193	[2]	$ 1,501	[1]	$ 592	[2]
AOCI reclassification impact on tax	500		100		500		200
Cost of Sales [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive (loss) income into earnings, Gains and Losses on Hedging Derivatives	1,615		193		1,501		592
AOCI reclassification impact on tax	$ 500		$ 100		$ 500		$ 200
[1]	Includes $1,615 and $1,501 of accumulated other comprehensive income (loss) reclassifications into cost of products sold for net losses on commodity contracts in the third quarter and first nine months of 2019 2019
[2]	Includes $ 193 and $ 592 of accumulated other comprehensive income (loss) reclassifications into cost of products sold for net losses on commodity contracts in the third quarter and first nine months of 2018 , respectively. The tax impact of those reclassifications w as $ 100 and $ 200 in the third quarter and first nine months of 2018 , respectively .

Segments - Segments (Detail)

Segments - Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net sales	$ 5,464,502	$ 6,742,202	$ 17,457,112	$ 18,771,395
Earnings (loss) before income taxes and noncontrolling interests	380,339	922,502	1,604,577	2,352,115
Total assets	18,506,265		18,506,265		$ 17,920,588
Operating Segments [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	3,244,473	4,401,610	10,897,322	12,151,843
Earnings (loss) before income taxes and noncontrolling interests	309,939	1,095,360	1,578,257	2,617,647
Total assets	9,117,610		9,117,610		9,244,086
Operating Segments [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	1,820,359	1,849,218	5,225,064	5,056,299
Earnings (loss) before income taxes and noncontrolling interests	170,214	138,688	363,731	380,268
Total assets	4,730,410		4,730,410		4,734,636
Operating Segments [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	399,670	491,374	1,334,726	1,563,253
Earnings (loss) before income taxes and noncontrolling interests	(10,599)	(29,074)	64,333	180,468
Total assets	3,225,367		3,225,367		3,492,126
Intercompany Eliminations [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	825,237	1,055,093	2,542,008	3,019,199
Intercompany Eliminations [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	57,517	56,185	174,718	142,862
Intercompany Eliminations [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	2,063,167	2,923,196	6,917,523	8,687,408
Corporate and Eliminations Items [Member]
Segment Reporting Information [Line Items]
Net sales	(2,945,921)	(4,034,474)	(9,634,249)	(11,849,469)
Earnings (loss) before income taxes and noncontrolling interests	(89,215)	$ (282,472)	(401,744)	$ (826,268)
Total assets	$ 1,432,878		$ 1,432,878		$ 449,740

Revenue - Schedule of Net Sales

Revenue - Schedule of Net Sales Disaggregates by Major Source (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Revenue from Contract with Customers [Line Items]
Revenues	$ 5,464,502	$ 6,742,202	$ 17,457,112	$ 18,771,395
Sheet [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,513,884	2,051,634	5,071,027	5,692,281
Bar [Member]
Revenue from Contract with Customers [Line Items]
Revenues	979,082	1,243,890	3,173,289	3,592,475
Structural [Member]
Revenue from Contract with Customers [Line Items]
Revenues	378,670	503,733	1,214,355	1,348,987
Plate [Member]
Revenue from Contract with Customers [Line Items]
Revenues	372,837	602,353	1,438,651	1,518,100
Tubular Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	296,519	357,815	919,711	1,040,611
Rebar Fabrication [Member]
Revenue from Contract with Customers [Line Items]
Revenues	469,180	412,977	1,249,912	1,133,117
Other Steel Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,054,660	1,078,426	3,055,441	2,882,571
Raw Materials [Member]
Revenue from Contract with Customers [Line Items]
Revenues	399,670	491,374	1,334,726	1,563,253
Steel Mills [Member]
Revenue from Contract with Customers [Line Items]
Revenues	3,244,473	4,401,610	10,897,322	12,151,843
Steel Mills [Member] | Sheet [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,513,884	2,051,634	5,071,027	5,692,281
Steel Mills [Member] | Bar [Member]
Revenue from Contract with Customers [Line Items]
Revenues	979,082	1,243,890	3,173,289	3,592,475
Steel Mills [Member] | Structural [Member]
Revenue from Contract with Customers [Line Items]
Revenues	378,670	503,733	1,214,355	1,348,987
Steel Mills [Member] | Plate [Member]
Revenue from Contract with Customers [Line Items]
Revenues	372,837	602,353	1,438,651	1,518,100
Steel Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,820,359	1,849,218	5,225,064	5,056,299
Steel Products [Member] | Tubular Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	296,519	357,815	919,711	1,040,611
Steel Products [Member] | Rebar Fabrication [Member]
Revenue from Contract with Customers [Line Items]
Revenues	469,180	412,977	1,249,912	1,133,117
Steel Products [Member] | Other Steel Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,054,660	1,078,426	3,055,441	2,882,571
Raw Materials [Member]
Revenue from Contract with Customers [Line Items]
Revenues	399,670	491,374	1,334,726	1,563,253
Raw Materials [Member] | Raw Materials [Member]
Revenue from Contract with Customers [Line Items]
Revenues	$ 399,670	$ 491,374	$ 1,334,726	$ 1,563,253

Earnings Per Share - Computatio

Earnings Per Share - Computations of Basic and Diluted Net Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Earnings Per Share [Abstract]
Basic net earnings	$ 275,031	$ 676,656	$ 1,163,320	$ 1,713,988
Earnings allocated to participating securities, Basic	(1,655)	(2,807)	(6,295)	(6,707)
Net earnings available to common stockholders, Basic	$ 273,376	$ 673,849	$ 1,157,025	$ 1,707,281
Average shares outstanding	304,637	315,913	305,553	317,928
Basic net earnings per share	$ 0.90	$ 2.13	$ 3.79	$ 5.37
Diluted net earnings	$ 275,031	$ 676,656	$ 1,163,320	$ 1,713,988
Earnings allocated to participating securities, Diluted	(1,656)	(2,796)	(6,295)	(6,684)
Net earnings available to common stockholders, Diluted	$ 273,375	$ 673,860	$ 1,157,025	$ 1,707,304
Dilutive effect of stock options and other	343	885	476	954
Diluted average shares outstanding	304,980	316,798	306,029	318,882
Diluted net earnings per share	$ 0.90	$ 2.13	$ 3.78	$ 5.35

Earnings Per Share - Anti-dilut

Earnings Per Share - Anti-dilutive Stock Options (Detail) - $ / shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Earnings Per Share [Abstract]
Weighted-average shares	963	265	963	89
Weighted-average exercise price	$ 60.92	$ 65.80	$ 60.92	$ 65.80