Nucor (NUE) 10-Q 7 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 29, 2018shares
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 29, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	NUE
Entity Registrant Name	NUCOR CORP
Entity Central Index Key	73,309
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding	313,932,540

Condensed Consolidated Statemen

Condensed Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Income Statement [Abstract]
Net sales	$ 6,742,202	$ 5,170,117	$ 18,771,395	$ 15,160,065
Costs, expenses and other:
Cost of products sold	5,452,052	4,591,153	15,588,249	13,111,226
Marketing, administrative and other expenses	234,081	172,792	651,422	519,429
Equity in earnings of unconsolidated affiliates	(13,634)	(7,743)	(34,157)	(29,801)
Impairment of assets	110,000		110,000
Interest expense, net	37,201	43,310	103,766	131,495
Costs, expenses and other, total	5,819,700	4,799,512	16,419,280	13,732,349
Earnings before income taxes and noncontrolling interests	922,502	370,605	2,352,115	1,427,716
Provision for income taxes	216,215	104,500	552,101	442,239
Net earnings	706,287	266,105	1,800,014	985,477
Earnings attributable to noncontrolling interests	29,631	11,255	86,026	50,680
Net earnings attributable to Nucor stockholders	$ 676,656	$ 254,850	$ 1,713,988	$ 934,797
Net earnings per share:
Basic	$ 2.13	$ 0.79	$ 5.37	$ 2.91
Diluted	$ 2.13	$ 0.79	$ 5.35	$ 2.90
Average shares outstanding:
Basic	315,913	320,096	317,928	320,253
Diluted	316,798	320,763	318,882	321,045

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Statement Of Comprehensive Income [Abstract]
Net earnings	$ 706,287	$ 266,105	$ 1,800,014	$ 985,477
Other comprehensive income (loss):
Net unrealized income (loss) on hedging derivatives, net of income taxes of $(400) and $300 for the third quarter of 2018 and 2017, respectively, and $(1,000) and $(700) for the first nine months of 2018 and 2017, respectively	(1,393)	405	(5,792)	(1,301)
Reclassification adjustment for loss on settlement of hedging derivatives included in net income, net of income taxes of $100 and $0 for the third quarter of 2018 and 2017, respectively, and $200 and $300 for the first nine months of 2018 and 2017, respectively	193	195	592	851
Foreign currency translation gain (loss), net of income taxes of $0 for the third quarter of 2018 and 2017, and $0 for the first nine months of 2018 and 2017	22,625	74,479	(14,726)	100,437
Net current-period other comprehensive income (loss)	21,425	75,079	(19,926)	99,987
Comprehensive income	727,712	341,184	1,780,088	1,085,464
Comprehensive income attributable to noncontrolling interests	(29,631)	(11,255)	(86,026)	(50,680)
Comprehensive income attributable to Nucor stockholders	$ 698,081	$ 329,929	$ 1,694,062	$ 1,034,784

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Statement Of Comprehensive Income [Abstract]
Net unrealized income (loss) on hedging derivatives, tax	$ (400)	$ 300	$ (1,000)	$ (700)
Reclassification adjustment for loss on settlement of hedging derivatives included in net income, tax effect	100	0	200	300
Foreign currency translation gain (loss) tax	$ 0	$ 0	$ 0	$ 0

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 1,932,155	$ 949,104
Short-term investments		50,000
Accounts receivable, net	2,636,038	2,028,545
Inventories, net	4,105,714	3,461,686
Other current assets	170,344	335,085
Total current assets	8,844,251	6,824,420
Property, plant and equipment, net	5,151,302	5,093,147
Goodwill	2,194,231	2,196,058
Other intangible assets, net	847,569	914,646
Other assets	925,540	812,987
Total assets	17,962,893	15,841,258
Current liabilities:
Short-term debt	52,829	52,833
Long-term debt due within one year		500,000
Accounts payable	1,447,528	1,181,346
Salaries, wages and related accruals	679,954	516,660
Accrued expenses and other current liabilities	627,384	573,925
Total current liabilities	2,807,695	2,824,764
Long-term debt due after one year	4,232,760	3,242,242
Deferred credits and other liabilities	748,017	689,464
Total liabilities	7,788,472	6,756,470
Nucor stockholders' equity:
Common stock	152,061	151,960
Additional paid-in capital	2,065,299	2,021,339
Retained earnings	9,814,073	8,463,709
Accumulated other comprehensive loss, net of income taxes	(274,607)	(254,681)
Treasury stock	(1,964,689)	(1,643,291)
Total Nucor stockholders' equity	9,792,137	8,739,036
Noncontrolling interests	382,284	345,752
Total equity	10,174,421	9,084,788
Total liabilities and equity	$ 17,962,893	$ 15,841,258

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Operating activities:
Net earnings	$ 1,800,014	$ 985,477
Adjustments:
Depreciation	474,330	474,822
Amortization	66,684	68,394
Stock-based compensation	65,597	51,227
Deferred income taxes	54,162	(38,335)
Distributions from affiliates	29,325	48,037
Equity in earnings of unconsolidated affiliates	(34,157)	(29,801)
Impairment of assets	110,000
Changes in assets and liabilities (exclusive of acquisitions and dispositions):
Accounts receivable	(615,118)	(406,582)
Inventories	(644,865)	(957,029)
Accounts payable	229,552	451,774
Federal income taxes	168,639	(30,859)
Salaries, wages and related accruals	173,732	74,306
Other operating activities	23,564	75,137
Cash provided by operating activities	1,901,459	766,568
Investing activities:
Capital expenditures	(624,739)	(292,312)
Investment in and advances to affiliates	(111,540)	(19,000)
Disposition of plant and equipment	27,964	19,420
Acquisitions (net of cash acquired)		(543,153)
Purchases of investments		(50,000)
Proceeds from the sale of investments	50,000	150,000
Other investing activities	25,347	(1,455)
Cash used in investing activities	(632,968)	(736,500)
Financing activities:
Net change in short-term debt	(5)	32,409
Proceeds from long-term debt, net of discount	995,710
Repayments of long-term debt	(500,000)
Bond issuance related costs	(7,625)
Issuance of common stock	24,102	5,417
Payment of tax withholdings on certain stock-based compensation	(22,123)	(13,960)
Distributions to noncontrolling interests	(49,494)	(85,094)
Cash dividends	(364,982)	(364,302)
Acquisition of treasury stock	(351,392)	(90,305)
Other financing activities	(5,248)	(1,703)
Cash used in financing activities	(281,057)	(517,538)
Effect of exchange rate changes on cash	(4,383)	17,453
Increase (decrease) in cash and cash equivalents	983,051	(470,017)
Cash and cash equivalents-beginning of year	949,104	2,045,961
Cash and cash equivalents-end of nine months	1,932,155	1,575,944
Non-cash investing activity:
Change in accrued plant and equipment purchases and assets recorded under capital lease arrangements	$ 40,996	$ 42,810

Basis of Interim Presentation

Basis of Interim Presentation	9 Months Ended
	Sep. 29, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Interim Presentation	1. BASIS OF INTERIM PRESENTATION: The information furnished in this Item 1 reflects all adjustments which are, in the opinion of management, necessary to a fair statement of the results for the interim periods presented and are of a normal and recurring nature unless otherwise noted. The information furnished has not been audited; however, the December 31, 2017 condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by accounting principles generally accepted in the United States of America. The unaudited condensed consolidated financial statements in this Item 1 should be read in conjunction with the audited consolidated financial statements and the notes thereto included in Nucor’s Annual Report on Form 10-K Reclassifications – In the first quarter of 2018, the Company began reporting its tubular products and piling products businesses as part of the steel products segment. These businesses were previously included in the steel mills segment and were reclassified to the steel products segment as part of a realignment of Nucor’s reportable segments to reflect the way in which they are now viewed by management and how segment performance assessments will be made by the chief operating decision maker beginning in such period. As a result, certain prior period amounts have been reclassified to conform to the current year presentation. These reclassifications did not have an impact on the condensed consolidated financial statements of the Company for the prior periods presented. See Note 15 for more information related to this segment realignment. Recently Adopted Accounting Pronouncements – In the first quarter of 2018, we adopted new accounting guidance related to revenue recognition for all contracts using the modified retrospective method. The modified retrospective method requires that the cumulative effect of initially applying this new guidance be recorded as an adjustment to the opening balance of retained earnings in the condensed consolidated balance sheet. The adoption of this new accounting guidance did not have an impact on any prior period earnings attributable to Nucor stockholders, and no adjustment was recorded to the opening retained earnings balance as of January 1, 2018. Retrospective adjustment of comparative prior period information is not required when using the modified retrospective adoption method, and no comparative prior periods have been adjusted for the new guidance. The adoption of the new revenue accounting guidance did not significantly change the way we recognize revenue. To illustrate this, if we had continued using the previous accounting guidance in effect before the adoption of the new revenue accounting guidance, our consolidated net sales for the third quarter and first nine months of 2018 would have increased approximately $25.2 million, or 0.4%, and $58.1 million, or 0.3%, respectively, and cost of products sold would have increased by the same amounts. There would have been no impact on any other financial statement line items in the condensed consolidated financial statements for the third quarter or first nine months of 2018. See Note 16 for disclosures required by the new revenue accounting guidance. In the first quarter of 2018, we adopted new accounting guidance regarding the recognition and measurement of financial assets and financial liabilities. Changes to the current accounting guidance primarily affect the accounting for equity investments, financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. In addition, the Financial Accounting Standards Board clarified guidance related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale In the first quarter of 2018, we adopted new accounting guidance regarding the presentation and classification of certain cash receipts and cash payments in the statement of cash flows. The new guidance addresses specific cash flow presentation issues in order to reduce diversity in existing practice. The adoption of this new guidance did not have a material impact on the Company’s consolidated financial statements. In the first quarter of 2018, we adopted new accounting guidance regarding intra-entity transfers of assets other than inventory. The new guidance requires that an entity should recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The adoption of this new guidance did not have a material impact on the Company’s consolidated financial statements. Recently Issued Accounting Pronouncements— In February 2016, new accounting guidance was issued regarding the accounting for leases. The new guidance requires all lessees to recognize on the balance sheet right to use assets and lease liabilities for the rights and obligations created by lease arrangements with terms greater than 12 months. The new guidance is effective for the Company for annual and interim reporting periods beginning after December 15, 2018. In July 2018, this accounting guidance was amended to permit companies to recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption and to continue reporting comparative periods prior to adoption in accordance with current lease guidance. The Company will adopt this new guidance in the first quarter of 2019 and will record a cumulative adjustment to the January 1, 2019 retained earnings balance. While the adoption of this new guidance is expected to increase assets and liabilities due to the recognition of lease rights and obligations on the Company’s consolidated balance sheet effective January 1, 2019, the Company does not expect the adoption of this new guidance to have a significant impact on its consolidated statement of earnings, statement of comprehensive income or statement of cash flows. In February 2018, new accounting guidance was issued regarding the tax effects of the Tax Cuts and Jobs Act (the “Tax Reform Act”). The new guidance allows for a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Reform Act to improve the usefulness of information reported to financial statement users. The new guidance is effective for the Company for annual and interim reporting periods beginning after December 15, 2018. The Company does not expect the adoption of this new guidance to have a material impact on its consolidated financial statements.

Inventories

Inventories	9 Months Ended
	Sep. 29, 2018
Inventory Disclosure [Abstract]
Inventories	2. INVENTORIES: Inventories consisted of approximately 40% raw materials and supplies and 60% finished and semi-finished products at September 29, 2018 (42% and 58%, respectively, at December 31, 2017). Nucor’s manufacturing process consists of a continuous, vertically integrated process from which products are sold to customers at various stages throughout the process. Since most steel products can be classified as either finished or semi-finished products, these two categories of inventory are combined.

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 29, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	3. PROPERTY, PLANT AND EQUIPMENT: Property, plant and equipment is recorded net of accumulated depreciation of $9.14 billion at September 29, 2018 ($8.70 billion at December 31, 2017). In September 2018, Nucor performed an impairment analysis of its proved producing natural gas well assets due to the current and projected natural gas pricing environment at our sales point in the Piceance Basin, which continued to deteriorate during 2018. Management has monitored these assets since the last impairment analysis was performed in the fourth quarter of 2017, and the deterioration in the current and projected natural gas pricing and, in particular, the projected natural gas pricing at our sales point in the Piceance Basin reached such a level in the third quarter of 2018 that management determined that a triggering event had occurred. One of the main assumptions that most significantly affects the cash flow determination is management’s estimate of future natural gas prices. The pricing used in this 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. The impairment analysis was performed on each of Nucor’s three groups (“fields”) of wells, with each field defined by common geographic location. Two of Nucor’s three fields of wells did not pass the undiscounted cash flow impairment analysis. An after-tax

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 29, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	4. GOODWILL AND OTHER INTANGIBLE ASSETS: The change in the net carrying amount of goodwill for the nine months ended September 29, 2018, by segment, was as follows (in thousands): Steel Mills Steel Products Raw Materials Total Balance at December 31, 2017 $ 745,484 $ 720,997 $ 729,577 $ 2,196,058 Translation — (1,827 ) — (1,827 ) Reclassifications (153,498 ) 153,498 — — Balance at September 29, 2018 $ 591,986 $ 872,668 $ 729,577 $ 2,194,231 Previously, Nucor’s tubular products and piling products businesses were reported in the steel mills segment. Beginning in the first quarter of 2018, these businesses were reclassified to the steel products segment to better reflect the way in which they are viewed by management. Nucor completed its most recent annual goodwill impairment testing during the fourth quarter of 2017 and concluded that as of such time there was no impairment of goodwill for any of its reporting units. There have been no triggering events requiring an interim assessment for impairment since the most recent annual goodwill impairment testing date. 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 29, 2018 and December 31, 2017 (in thousands): September 29, 2018 December 31, 2017 Gross Accumulated Gross Accumulated Customer relationships $ 1,419,899 $ 695,613 $ 1,420,224 $ 641,089 Trademarks and trade names 176,402 85,022 176,471 77,208 Other 62,807 30,904 62,805 26,557 $ 1,659,108 $ 811,539 $ 1,659,500 $ 744,854 Intangible asset amortization expense in the third quarter of 2018 and 2017 was $22.1 million and $23.0 million, respectively, and was $66.7 million and $68.4 million in the first nine months of 2018 and 2017, respectively. Annual amortization expense is estimated to be $88.6 million in 2018; $86.7 million in 2019; $84.4 million in 2020; $83.1 million in 2021; and $80.8 million in 2022.

Equity Investments

Equity Investments	9 Months Ended
	Sep. 29, 2018
Equity Method Investments and Joint Ventures [Abstract]
Equity Investments	5. EQUITY INVESTMENTS: The carrying value of our equity investments in domestic and foreign companies was $858.0 million at September 29, 2018 ($750.1 million at December 31, 2017) and is recorded in other assets in the condensed consolidated balance sheets. 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 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 Nucor’s investment in Duferdofin Nucor at September 29, 2018 was $272.2 million ($285.9 million at December 31, 2017). Nucor’s 50% share of the total net assets of Duferdofin Nucor was $113.6 million at September 29, 2018, resulting in a basis difference of $158.6 million due to the step-up step-up As of September 29, 2018, Nucor had outstanding notes receivable of €35.0 million ($40.6 million) from Duferdofin Nucor (€35.0 million, or $41.9 million, as of December 31, 2017). The notes receivable bear interest at 0.84% and reset annually on September 30 to the 12-month Euro Interbank Offered Rate plus 1% per year. The maturity date of the principal amounts was extended to January 31, 2022 during the first quarter of 2018. As of September 29, 2018 and December 31, 2017, 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 ($185.8 million) at September 29, 2018. As of September 29, 2018, there was €148.5 million ($172.5 million) outstanding under that facility (€122.5 million, or $146.7 million, as of December 31, 2017). 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 (“Nucor-JFE”), 50-50 Nucor-JFE Nucor-JFE one-month Nucor-JFE ALL EQUITY INVESTMENTS Nucor reviews its equity investments for impairment if and when circumstances indicate that a decline in 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 revenues 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. 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. 29, 2018
Payables and Accruals [Abstract]
Current Liabilities	6. CURRENT LIABILITIES: Book overdrafts, included in accounts payable in the condensed consolidated balance sheets, were $161.8 million at September 29, 2018 ($139.2 million at December 31, 2017). Dividends payable, included in accrued expenses and other current liabilities in the condensed consolidated balance sheets, were $120.4 million at September 29, 2018 ($121.8 million at December 31, 2017).

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 29, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	7. FAIR VALUE MEASUREMENTS: The following table summarizes information regarding Nucor’s financial assets and financial liabilities that are measured at fair value as of September 29, 2018 and December 31, 2017 (in thousands). Nucor does not have any non-financial non-financial Fair Value Measurements at Reporting Date Quoted Prices Carrying Significant Significant Amount in Condensed Consolidated Description Balance Sheets (Level 1) (Level 2) (Level 3) As of September 29, 2018 Assets: Cash equivalents $ 1,578,541 $ 1,578,541 $ — $ — Derivative contracts 2,237 — 2,237 — Total assets $ 1,580,778 $ 1,578,541 $ 2,237 $ — Liabilities: Derivative contracts $ (10,500 ) $ — $ (10,500 ) $ — As of December 31, 2017 Assets: Cash equivalents $ 594,946 $ 594,946 $ — $ — Short-term investments 50,000 50,000 — — Derivative contracts 479 — 479 — Total assets $ 645,425 $ 644,946 $ 479 $ — Liabilities: Derivative contracts $ (8,531 ) $ — $ (8,531 ) $ — 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. Fair value measurements for Nucor’s derivatives, which are typically commodity or foreign exchange contracts, 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 $4.48 billion at September 29, 2018 ($4.19 billion at December 31, 2017). 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 29, 2018 and December 31, 2017, or similar debt with the same maturities, ratings and interest rates.

Contingencies

Contingencies	9 Months Ended
	Sep. 29, 2018
Commitments and Contingencies Disclosure [Abstract]
Contingencies	8. CONTINGENCIES: Nucor is subject to environmental laws and regulations established by federal, state and local authorities and, accordingly, makes provisions for the estimated costs of compliance. Of the undiscounted total of $17.5 million of accrued environmental costs at September 29, 2018 ($17.1 million at December 31, 2017), $3.2 million was classified in accrued expenses and other current liabilities ($3.8 million at December 31, 2017) and $14.3 million was classified in deferred credits and other liabilities ($13.3 million at December 31, 2017). Inherent uncertainties exist in these estimates primarily due to unknown conditions, evolving remediation technology and changing governmental regulations and legal standards. 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. 29, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	9. STOCK-BASED COMPENSATION: Overview – The Company maintains the Nucor Corporation 2014 Omnibus Incentive Compensation Plan (the “Omnibus Plan”) under which the Company may award stock-based compensation to key employees, officers and non-employee 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 29, 2018, 1.9 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 A summary of activity under Nucor’s stock option plans for the first nine months of 2018 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 4,106 $ 47.96 Granted 265 $ 65.80 Exercised (543 ) $ 44.33 $ 12,587 Canceled — $ — Outstanding at September 29, 2018 3,828 $ 49.71 6.7 years $ 53,223 Stock options exercisable at September 29, 2018 2,112 $ 45.41 5.3 years $ 38,166 Stock options granted to employees who are eligible for retirement on the date of 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 and $0.4 million in the third quarter of 2018 and 2017, respectively, and $4.3 million and $7.9 million in the first nine months of 2018 and 2017, respectively. As of September 29, 2018, unrecognized compensation expense related to stock options was $1.9 million, which is expected to be recognized over a weighted-average period of 1.9 years. Restricted Stock Units Nucor annually grants restricted stock units (“RSUs”) to key employees, officers and non-employee non-employee non-employee RSUs granted to employees who are eligible for retirement on the date of 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 A summary of Nucor’s RSU activity for the first nine months of 2018 is as follows (shares in thousands): Grant Date Shares Fair Value RSUs: Unvested at beginning of year 1,071 $ 52.62 Granted 1,013 $ 65.80 Vested (799 ) $ 59.23 Canceled (11 ) $ 55.02 Unvested at September 29, 2018 1,274 $ 58.93 Compensation expense for RSUs was $8.5 million and $6.1 million in the third quarter of 2018 and 2017, respectively, and $46.8 million and $32.2 million in the first nine months of 2018 and 2017, respectively. As of September 29, 2018, unrecognized compensation expense related to unvested RSUs was $53.9 million, which is expected to be recognized over a weighted-average period of 2.0 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 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 A summary of Nucor’s restricted stock activity under the AIP and the LTIP for the first nine months of 2018 is as follows (shares in thousands): Grant Date Shares Fair Value Restricted stock awards and RSUs: Unvested at beginning of year 91 $ 54.50 Granted 256 $ 67.68 Vested (217 ) $ 64.95 Canceled — $ — Unvested at September 29, 2018 130 $ 62.97 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 $4.9 million and $3.6 million in the third quarter of 2018 and 2017, respectively, and $14.6 million and $11.1 million in the first nine months of 2018 and 2017, respectively. As of September 29, 2018, unrecognized compensation expense related to unvested restricted stock awards was $2.0 million, which is expected to be recognized over a weighted-average period of 1.8 years.

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 29, 2018
Retirement Benefits [Abstract]
Employee Benefit Plans	10. EMPLOYEE BENEFIT PLAN: Nucor makes contributions to a Profit Sharing and Retirement Savings Plan for qualified employees based on the profitability of the Company. Nucor’s expense for these benefits totaled $86.4 million and $35.7 million in the third quarter of 2018 and 2017, respectively, and $226.5 million and $138.2 million in the first nine months of 2018 and 2017, respectively. The related liability for these benefits is included in salaries, wages and related accruals in the condensed consolidated balance sheets.

Interest Expense (Income)

Interest Expense (Income)	9 Months Ended
	Sep. 29, 2018
Banking and Thrift, Interest [Abstract]
Interest Expense (Income)	11. INTEREST EXPENSE (INCOME): The components of net interest expense for the third quarter and first nine months of 2018 and 2017 are as follows (in thousands): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 29, 2018 Sept. 30, 2017 Sept. 29, 2018 Sept. 30, 2017 Interest expense $ 44,789 $ 47,621 $ 120,308 $ 141,486 Interest income (7,588 ) (4,311 ) (16,542 ) (9,991 ) Interest expense, net $ 37,201 $ 43,310 $ 103,766 $ 131,495 Interest expense for the first nine months of 2018 decreased compared to the first nine months of 2017 in part due to a benefit received from entering into and settling a treasury lock instrument in anticipation of the Company’s debt issuance in the second quarter of 2018. The Company did not elect hedge accounting for this instrument.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 29, 2018
Income Tax Disclosure [Abstract]
Income Taxes	12. INCOME TAXES: The staff of the Securities and Exchange Commission issued Staff Accounting Bulletin No. 118 (“SAB 118”) to address situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Reform Act. Reflected in our 2017 financial results in accordance with SAB 118 were certain provisional income tax effects of the Tax Reform Act, including no tax impact related to the one-time In the third quarter of 2018, upon completion of its 2017 federal tax return, Nucor finalized the analysis of the previously estimated one-time The effective tax rate for the third quarter of 2018 was 23.4% compared to 28.2% for the third quarter of 2017. The decrease in the effective tax rate for the third quarter of 2018 as compared to the third quarter of 2017 was primarily due to the permanent lowering of the U.S. corporate federal income tax rate from 35% to 21% effective for the years beginning after December 31, 2017 under the Tax Reform Act. This decrease was somewhat offset by increases in the effective tax rate due to the elimination of the domestic manufacturing deduction under the Tax Reform Act. The third quarter of 2017 included a net tax benefit totaling $13.2 million related to a return to provision change in estimate and state tax credits. Nucor has concluded U.S. federal income tax matters for years through 2013. The tax years 2014 through 2017 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 tax years 2011 through 2017 remain open to examination by other major taxing jurisdictions to which Nucor is subject (primarily Canada and other state and local jurisdictions). Non-current Non-current

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 29, 2018
Federal Home Loan Banks [Abstract]
Stockholders' Equity	13. STOCKHOLDERS’ 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%, for the nine months ended September 29, 2018 and September 30, 2017 (in thousands): Attributable to Attributable to Nucor Noncontrolling Total Stockholders’ equity at December 31, 2017 $ 8,739,036 $ 345,752 $ 9,084,788 Total comprehensive income 1,694,062 86,026 1,780,088 Stock options 28,351 — 28,351 Issuance of stock under award plans, net of forfeitures 44,304 — 44,304 Amortization of unearned compensation 1,400 — 1,400 Treasury stock acquired (351,392 ) — (351,392 ) Dividends declared (363,624 ) — (363,624 ) Distributions to noncontrolling interests — (49,494 ) (49,494 ) Stockholders’ equity at September 29, 2018 $ 9,792,137 $ 382,284 $ 10,174,421 Attributable to Attributable to Nucor Noncontrolling Total Stockholders’ equity at December 31, 2016 $ 7,879,865 $ 374,843 $ 8,254,708 Total comprehensive income 1,034,784 50,680 1,085,464 Stock options 13,300 — 13,300 Issuance of stock under award plans, net of forfeitures 30,787 — 30,787 Amortization of unearned compensation 1,000 — 1,000 Treasury stock acquired (90,305 ) — (90,305 ) Dividends declared (364,046 ) — (364,046 ) Distributions to noncontrolling interests — (85,094 ) (85,094 ) Stockholders’ equity at September 30, 2017 $ 8,505,385 $ 340,429 $ 8,845,814 Dividends declared per share were $0.38 per share in the third quarter of 2018 ($0.3775 per share in the third quarter of 2017) and $1.14 per share in the first nine months of 2018 ($1.1325 per share in the first nine months of 2017). On September 6, 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, 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 repurchase programs. At September 29, 2018, the Company had the entire $2.0 billion available for share repurchases.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 29, 2018
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	14. 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 29, 2018 and September 30, 2017 (in thousands): Three Months (13 Weeks) Ended September 29, 2018 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive 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 (1) 193 — — 193 Net current-period other comprehensive income (loss) (1,200 ) 22,625 — 21,425 Accumulated other comprehensive loss at September 29, 2018 $ (8,000 ) $ (272,239 ) $ 5,632 $ (274,607 ) Nine Months (39 Weeks) Ended September 29, 2018 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive 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 (1) 592 — — 592 Net current-period other comprehensive income (loss) (5,200 ) (14,726 ) — (19,926 ) Accumulated other comprehensive loss at September 29, 2018 $ (8,000 ) $ (272,239 ) $ 5,632 $ (274,607 ) (1) Includes $193 and $592 of accumulated other comprehensive income 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 impacts of those reclassifications were $100 and $200, respectively. Three Months (13 Weeks) Ended September 30, 2017 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive loss at July 1, 2017 $ (300 ) $ (300,212 ) $ 7,577 $ (292,935 ) Other comprehensive income (loss) before reclassifications 405 74,479 — 74,884 Amounts reclassified from accumulated other comprehensive income (loss) into earnings (2) 195 — — 195 Net current-period other comprehensive income (loss) 600 74,479 — 75,079 Accumulated other comprehensive loss at September 30, 2017 $ 300 $ (225,733 ) $ 7,577 $ (217,856 ) Nine Months (39 Weeks) Ended September 30, 2017 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive loss at December 31, 2016 $ 750 $ (326,170 ) $ 7,577 $ (317,843 ) Other comprehensive income (loss) before reclassifications (1,301 ) 100,437 — 99,136 Amounts reclassified from accumulated other comprehensive income (loss) into earnings (2) 851 — — 851 Net current-period other comprehensive income (loss) (450 ) 100,437 — 99,987 Accumulated other comprehensive loss at September 30, 2017 $ 300 $ (225,733 ) $ 7,577 $ (217,856 ) (2) Includes $195 and $851 of accumulated other comprehensive income reclassifications into cost of products sold for net losses on commodity contracts in the third quarter and first nine months of 2017, respectively. The tax impacts of those reclassifications were $0 and $300, respectively.

Segments

Segments	9 Months Ended
	Sep. 29, 2018
Segment Reporting [Abstract]
Segments	15. SEGMENTS: Nucor reports its results in the following segments: steel mills, steel products and raw materials. The steel mills segment includes carbon and alloy steel in sheet, bars, structural and plate; steel trading businesses; rebar distribution businesses; and Nucor’s equity method investments in Duferdofin Nucor, NuMit and Nucor-JFE. Nu-Iron Previously, Nucor’s tubular products and piling products businesses were reported in the steel mills segment. Beginning in the first quarter of 2018, these businesses were reclassified to the steel products segment as part of a realignment of Nucor’s reportable segments to reflect the way in which they are now viewed by management and how segment performance assessments will be made by the chief operating decision maker beginning in such period. The segment data for the comparable periods has also been reclassified into the steel products segment in order to conform to the current year presentation. The steel mills, steel products and raw materials segments are consistent with the way Nucor manages its business, which is primarily based upon the similarity of the types of products produced and sold by each segment. Additionally, the composition of assets by segment at December 31, 2017 was reclassified to conform to the current year presentation. This reclassification between segments did not have any impact on the consolidated asset balances. Net interest expense, other income, 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 2018 and 2017 were as follows (in thousands): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 29, 2018 Sept. 30, 2017 Sept. 29, 2018 Sept. 30, 2017 Net sales to external customers: Steel mills $ 4,401,610 $ 3,214,921 $ 12,151,843 $ 9,809,492 Steel products 1,849,218 1,514,086 5,056,299 4,093,136 Raw materials 491,374 441,110 1,563,253 1,257,437 $ 6,742,202 $ 5,170,117 $ 18,771,395 $ 15,160,065 Intercompany sales: Steel mills $ 1,055,093 $ 764,977 $ 3,019,199 $ 2,182,582 Steel products 56,185 30,828 142,862 87,193 Raw materials 2,923,196 2,333,840 8,687,408 6,971,831 Corporate/eliminations (4,034,474 ) (3,129,645 ) (11,849,469 ) (9,241,606 ) $ — $ — $ — $ — Earnings (loss) before income taxes and noncontrolling interests: Steel mills $ 1,095,360 $ 405,097 $ 2,617,647 $ 1,628,800 Steel products 138,688 86,908 380,268 237,463 Raw materials (29,074 ) 9,957 180,468 102,575 Corporate/eliminations (282,472 ) (131,357 ) (826,268 ) (541,122 ) $ 922,502 $ 370,605 $ 2,352,115 $ 1,427,716 Sept. 29, 2018 Dec. 31, 2017 Segment assets: Steel mills $ 8,764,717 $ 7,671,217 Steel products 4,828,354 4,323,907 Raw materials 3,318,424 3,396,110 Corporate/eliminations 1,051,398 450,024 $ 17,962,893 $ 15,841,258

Revenue

Revenue	9 Months Ended
	Sep. 29, 2018
Revenue from Contract with Customer [Abstract]
Revenue	16. REVENUE: Revenue is recognized when obligations under the terms of contracts with our customers are satisfied; generally, this occurs upon shipment or when control is transferred. Revenue is measured as the amount of consideration expected to be received in exchange for transferring the goods. In addition, revenue is deferred when cash payments are received or due in advance of performance. The durations of Nucor’s contracts with customers are generally one year or less. Customer payment terms are generally 30 days. Contract liabilities are primarily related to deferred revenue resulting from cash payments received in advance from customers to protect against credit risk. Contract liabilities totaled $85.0 million as of September 29, 2018 ($72.3 million as of December 31, 2017), and are included in accrued expenses and other current liabilities in the condensed consolidated balance sheets. The amount of revenue reclassified from the December 31, 2017 contract liabilities balance during the first nine months of 2018 was approximately $60.8 million. The following table disaggregates our net sales by major source for the third quarter and first nine months of 2018 (in thousands): Three Months (13 Weeks) Ended September 29, 2018 Nine Months (39 Weeks) Ended September 29, 2018 Steel Mills Steel Raw Total Steel Mills Steel Raw 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 STEEL MILLS SEGMENT Sheet – For the majority of sheet products, we transfer control and recognize a sale when we ship the product from the sheet mill to our customer. The amount of consideration we receive and revenue we recognize for spot market sales are based upon prevailing prices at the time of sale. The amount of consideration we receive and revenue we recognize for contract customers are based primarily on pricing formulae that permit price adjustments to reflect changes in the current market-based indices and/or raw material costs near the time of shipment. The amount of tons sold to contract customers at any given time depends on a variety of factors, including our consideration of current and future market conditions, our strategy to appropriately balance spot and contract tons in a manner to meet our customers’ requirements while considering the expected profitability, our desire to sustain a diversified customer base and our end-use Bar, Structural and Plate – For the majority of bar, structural and plate products, we transfer control and recognize a sale when we ship the product from the mill to our customer. The significant majority of bar, structural and plate product sales are spot market sales, and the amount of consideration we receive and revenue we recognize for those sales are based upon prevailing prices at the time of sale. STEEL PRODUCTS SEGMENT Tubular Products – The tubular products businesses transfer control and recognize a sale when the product is shipped from our operating locations to our customers. The significant majority of tubular product sales are spot market sales, and the amount of consideration we receive and revenue we recognize for those sales are based upon prevailing prices at the time of sale. Rebar Fabrication – The majority of revenue for our rebar fabrication businesses relates to revenue from contracts with customers for the supply of fabricated rebar. For the majority of these transactions, we transfer control and recognize a sale when the products are shipped from our operating locations and collection is reasonably assured. Provisions for losses on incomplete contracts are made in the period in which such losses are determined. Our rebar fabrication businesses also generate a significant amount of revenue from contracts with customers in which they supply fabricated rebar and install it at the customer’s job site. There are two performance obligations for these types of contracts: the supply of the fabricated rebar and the installation of the supplied rebar at the customer’s job site. For the supply of fabricated rebar performance obligation, we transfer control and recognize a sale when the product is delivered to our customer’s job site. The transaction price allocated to this performance obligation is determined at the start of the contract, based on the then current market price for supplied fabricated rebar. For the installation of supplied rebar performance obligation, we transfer control and recognize a sale when the delivered material is installed. The transaction price allocated to this performance obligation is determined at the start of the contract, based on the then current market price for the installation of fabricated rebar. Variable consideration occurring from change orders and price escalations caused by changes in underlying material costs for previously satisfied performance obligations are recognized cumulatively in the period in which management believes that the amount of consideration is changed and collection is reasonably assured. Management reviews these situations on a case-by-case Other Steel Products – Other steel products include our joist, deck, cold finish, metal building systems, piling and the other remaining businesses that comprise the steel products segment. Generally for these businesses, we transfer control and recognize a sale when we ship the product from our operating locations to our customers. The amount of consideration we receive and revenue we recognize for those sales are agreed upon with the customers before the product is shipped. RAW MATERIALS SEGMENT The majority of the raw materials segment revenue from outside customers is generated by The David J. Joseph Company and its affiliates. We transfer control and recognize a sale based on the terms of the agreement with the customer, which is generally when the product has met the delivery requirements. The amount of consideration we receive and revenue we recognize for those sales is based on the contract with the customer, which generally reflects current market prices at the time the contract is entered into.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 29, 2018
Earnings Per Share [Abstract]
Earnings Per Share	17. EARNINGS PER SHARE: The computations of basic and diluted net earnings per share for the third quarter and first nine months of 2018 and 2017 are as follows (in thousands, except per share amounts): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 29, 2018 Sept. 30, 2017 Sept. 29, 2018 Sept. 30, 2017 Basic net earnings per share: Basic net earnings $ 676,656 $ 254,850 $ 1,713,988 $ 934,797 Earnings allocated to participating securities (2,807 ) (900 ) (6,707 ) (3,239 ) Net earnings available to common stockholders $ 673,849 $ 253,950 $ 1,707,281 $ 931,558 Average shares outstanding 315,913 320,096 317,928 320,253 Basic net earnings per share $ 2.13 $ 0.79 $ 5.37 $ 2.91 Diluted net earnings per share: Diluted net earnings $ 676,656 $ 254,850 $ 1,713,988 $ 934,797 Earnings allocated to participating securities (2,796 ) (899 ) (6,684 ) (3,233 ) Net earnings available to common stockholders $ 673,860 $ 253,951 $ 1,707,304 $ 931,564 Diluted average shares outstanding: Basic shares outstanding 315,913 320,096 317,928 320,253 Dilutive effect of stock options and other 885 667 954 792 316,798 320,763 318,882 321,045 Diluted net earnings per share $ 2.13 $ 0.79 $ 5.35 $ 2.90 The following stock options were excluded from the computation of diluted net earnings per share for the third quarter and first nine months of 2018 and 2017 because their effect would have been anti-dilutive (in thousands, except per share amounts): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 29, 2018 Sept. 30, 2017 Sept. 29, 2018 Sept. 30, 2017 Anti-dilutive stock options: Weighted-average shares 265 698 89 309 Weighted-average exercise price $ 65.80 $ 59.07 $ 65.80 $ 59.07

Basis of Interim Presentation (

Basis of Interim Presentation (Policies)	9 Months Ended
	Sep. 29, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Reclassifications	Reclassifications – In the first quarter of 2018, the Company began reporting its tubular products and piling products businesses as part of the steel products segment. These businesses were previously included in the steel mills segment and were reclassified to the steel products segment as part of a realignment of Nucor’s reportable segments to reflect the way in which they are now viewed by management and how segment performance assessments will be made by the chief operating decision maker beginning in such period. As a result, certain prior period amounts have been reclassified to conform to the current year presentation. These reclassifications did not have an impact on the condensed consolidated financial statements of the Company for the prior periods presented. See Note 15 for more information related to this segment realignment.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements – In the first quarter of 2018, we adopted new accounting guidance related to revenue recognition for all contracts using the modified retrospective method. The modified retrospective method requires that the cumulative effect of initially applying this new guidance be recorded as an adjustment to the opening balance of retained earnings in the condensed consolidated balance sheet. The adoption of this new accounting guidance did not have an impact on any prior period earnings attributable to Nucor stockholders, and no adjustment was recorded to the opening retained earnings balance as of January 1, 2018. Retrospective adjustment of comparative prior period information is not required when using the modified retrospective adoption method, and no comparative prior periods have been adjusted for the new guidance. The adoption of the new revenue accounting guidance did not significantly change the way we recognize revenue. To illustrate this, if we had continued using the previous accounting guidance in effect before the adoption of the new revenue accounting guidance, our consolidated net sales for the third quarter and first nine months of 2018 would have increased approximately $25.2 million, or 0.4%, and $58.1 million, or 0.3%, respectively, and cost of products sold would have increased by the same amounts. There would have been no impact on any other financial statement line items in the condensed consolidated financial statements for the third quarter or first nine months of 2018. See Note 16 for disclosures required by the new revenue accounting guidance. In the first quarter of 2018, we adopted new accounting guidance regarding the recognition and measurement of financial assets and financial liabilities. Changes to the current accounting guidance primarily affect the accounting for equity investments, financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. In addition, the Financial Accounting Standards Board clarified guidance related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale In the first quarter of 2018, we adopted new accounting guidance regarding the presentation and classification of certain cash receipts and cash payments in the statement of cash flows. The new guidance addresses specific cash flow presentation issues in order to reduce diversity in existing practice. The adoption of this new guidance did not have a material impact on the Company’s consolidated financial statements. In the first quarter of 2018, we adopted new accounting guidance regarding intra-entity transfers of assets other than inventory. The new guidance requires that an entity should recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The adoption of this new guidance did not have a material impact on the Company’s consolidated financial statements.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements— In February 2016, new accounting guidance was issued regarding the accounting for leases. The new guidance requires all lessees to recognize on the balance sheet right to use assets and lease liabilities for the rights and obligations created by lease arrangements with terms greater than 12 months. The new guidance is effective for the Company for annual and interim reporting periods beginning after December 15, 2018. In July 2018, this accounting guidance was amended to permit companies to recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption and to continue reporting comparative periods prior to adoption in accordance with current lease guidance. The Company will adopt this new guidance in the first quarter of 2019 and will record a cumulative adjustment to the January 1, 2019 retained earnings balance. While the adoption of this new guidance is expected to increase assets and liabilities due to the recognition of lease rights and obligations on the Company’s consolidated balance sheet effective January 1, 2019, the Company does not expect the adoption of this new guidance to have a significant impact on its consolidated statement of earnings, statement of comprehensive income or statement of cash flows. In February 2018, new accounting guidance was issued regarding the tax effects of the Tax Cuts and Jobs Act (the “Tax Reform Act”). The new guidance allows for a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Reform Act to improve the usefulness of information reported to financial statement users. The new guidance is effective for the Company for annual and interim reporting periods beginning after December 15, 2018. The Company does not expect the adoption of this new guidance to have a material impact on its consolidated financial statements.

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 29, 2018
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 29, 2018, by segment, was as follows (in thousands): Steel Mills Steel Products Raw Materials Total Balance at December 31, 2017 $ 745,484 $ 720,997 $ 729,577 $ 2,196,058 Translation — (1,827 ) — (1,827 ) Reclassifications (153,498 ) 153,498 — — Balance at September 29, 2018 $ 591,986 $ 872,668 $ 729,577 $ 2,194,231
Schedule of Intangible Assets	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 29, 2018 and December 31, 2017 (in thousands): September 29, 2018 December 31, 2017 Gross Accumulated Gross Accumulated Customer relationships $ 1,419,899 $ 695,613 $ 1,420,224 $ 641,089 Trademarks and trade names 176,402 85,022 176,471 77,208 Other 62,807 30,904 62,805 26,557 $ 1,659,108 $ 811,539 $ 1,659,500 $ 744,854

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 29, 2018
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 are measured at fair value as of September 29, 2018 and December 31, 2017 (in thousands). Nucor does not have any non-financial non-financial Fair Value Measurements at Reporting Date Quoted Prices Carrying Significant Significant Amount in Condensed Consolidated Description Balance Sheets (Level 1) (Level 2) (Level 3) As of September 29, 2018 Assets: Cash equivalents $ 1,578,541 $ 1,578,541 $ — $ — Derivative contracts 2,237 — 2,237 — Total assets $ 1,580,778 $ 1,578,541 $ 2,237 $ — Liabilities: Derivative contracts $ (10,500 ) $ — $ (10,500 ) $ — As of December 31, 2017 Assets: Cash equivalents $ 594,946 $ 594,946 $ — $ — Short-term investments 50,000 50,000 — — Derivative contracts 479 — 479 — Total assets $ 645,425 $ 644,946 $ 479 $ — Liabilities: Derivative contracts $ (8,531 ) $ — $ (8,531 ) $ —

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 29, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Plans Activity	A summary of activity under Nucor’s stock option plans for the first nine months of 2018 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 4,106 $ 47.96 Granted 265 $ 65.80 Exercised (543 ) $ 44.33 $ 12,587 Canceled — $ — Outstanding at September 29, 2018 3,828 $ 49.71 6.7 years $ 53,223 Stock options exercisable at September 29, 2018 2,112 $ 45.41 5.3 years $ 38,166
Summary of Nucor's RSU Activity	A summary of Nucor’s RSU activity for the first nine months of 2018 is as follows (shares in thousands): Grant Date Shares Fair Value RSUs: Unvested at beginning of year 1,071 $ 52.62 Granted 1,013 $ 65.80 Vested (799 ) $ 59.23 Canceled (11 ) $ 55.02 Unvested at September 29, 2018 1,274 $ 58.93
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 2018 is as follows (shares in thousands): Grant Date Shares Fair Value Restricted stock awards and RSUs: Unvested at beginning of year 91 $ 54.50 Granted 256 $ 67.68 Vested (217 ) $ 64.95 Canceled — $ — Unvested at September 29, 2018 130 $ 62.97

Interest Expense (Income) (Tabl

Interest Expense (Income) (Tables)	9 Months Ended
	Sep. 29, 2018
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 2018 and 2017 are as follows (in thousands): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 29, 2018 Sept. 30, 2017 Sept. 29, 2018 Sept. 30, 2017 Interest expense $ 44,789 $ 47,621 $ 120,308 $ 141,486 Interest income (7,588 ) (4,311 ) (16,542 ) (9,991 ) Interest expense, net $ 37,201 $ 43,310 $ 103,766 $ 131,495

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 29, 2018
Federal Home Loan Banks [Abstract]
Schedule of Changes in Stockholders' 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%, for the nine months ended September 29, 2018 and September 30, 2017 (in thousands): Attributable to Attributable to Nucor Noncontrolling Total Stockholders’ equity at December 31, 2017 $ 8,739,036 $ 345,752 $ 9,084,788 Total comprehensive income 1,694,062 86,026 1,780,088 Stock options 28,351 — 28,351 Issuance of stock under award plans, net of forfeitures 44,304 — 44,304 Amortization of unearned compensation 1,400 — 1,400 Treasury stock acquired (351,392 ) — (351,392 ) Dividends declared (363,624 ) — (363,624 ) Distributions to noncontrolling interests — (49,494 ) (49,494 ) Stockholders’ equity at September 29, 2018 $ 9,792,137 $ 382,284 $ 10,174,421 Attributable to Attributable to Nucor Noncontrolling Total Stockholders’ equity at December 31, 2016 $ 7,879,865 $ 374,843 $ 8,254,708 Total comprehensive income 1,034,784 50,680 1,085,464 Stock options 13,300 — 13,300 Issuance of stock under award plans, net of forfeitures 30,787 — 30,787 Amortization of unearned compensation 1,000 — 1,000 Treasury stock acquired (90,305 ) — (90,305 ) Dividends declared (364,046 ) — (364,046 ) Distributions to noncontrolling interests — (85,094 ) (85,094 ) Stockholders’ equity at September 30, 2017 $ 8,505,385 $ 340,429 $ 8,845,814

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 29, 2018
Equity [Abstract]
Components of Accumulated 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 29, 2018 and September 30, 2017 (in thousands): Three Months (13 Weeks) Ended September 29, 2018 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive 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 (1) 193 — — 193 Net current-period other comprehensive income (loss) (1,200 ) 22,625 — 21,425 Accumulated other comprehensive loss at September 29, 2018 $ (8,000 ) $ (272,239 ) $ 5,632 $ (274,607 ) Nine Months (39 Weeks) Ended September 29, 2018 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive 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 (1) 592 — — 592 Net current-period other comprehensive income (loss) (5,200 ) (14,726 ) — (19,926 ) Accumulated other comprehensive loss at September 29, 2018 $ (8,000 ) $ (272,239 ) $ 5,632 $ (274,607 ) (1) Includes $193 and $592 of accumulated other comprehensive income 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 impacts of those reclassifications were $100 and $200, respectively. Three Months (13 Weeks) Ended September 30, 2017 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive loss at July 1, 2017 $ (300 ) $ (300,212 ) $ 7,577 $ (292,935 ) Other comprehensive income (loss) before reclassifications 405 74,479 — 74,884 Amounts reclassified from accumulated other comprehensive income (loss) into earnings (2) 195 — — 195 Net current-period other comprehensive income (loss) 600 74,479 — 75,079 Accumulated other comprehensive loss at September 30, 2017 $ 300 $ (225,733 ) $ 7,577 $ (217,856 ) Nine Months (39 Weeks) Ended September 30, 2017 Gains and Losses on Foreign Currency Adjustment to Early Hedging Derivatives Gain (Loss) Retiree Medical Plan Total Accumulated other comprehensive loss at December 31, 2016 $ 750 $ (326,170 ) $ 7,577 $ (317,843 ) Other comprehensive income (loss) before reclassifications (1,301 ) 100,437 — 99,136 Amounts reclassified from accumulated other comprehensive income (loss) into earnings (2) 851 — — 851 Net current-period other comprehensive income (loss) (450 ) 100,437 — 99,987 Accumulated other comprehensive loss at September 30, 2017 $ 300 $ (225,733 ) $ 7,577 $ (217,856 ) (2) Includes $195 and $851 of accumulated other comprehensive income reclassifications into cost of products sold for net losses on commodity contracts in the third quarter and first nine months of 2017, respectively. The tax impacts of those reclassifications were $0 and $300, respectively.

Segments (Tables)

Segments (Tables)	9 Months Ended
	Sep. 29, 2018
Segment Reporting [Abstract]
Segments	Nucor’s results by segment for the third quarter and first nine months of 2018 and 2017 were as follows (in thousands): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 29, 2018 Sept. 30, 2017 Sept. 29, 2018 Sept. 30, 2017 Net sales to external customers: Steel mills $ 4,401,610 $ 3,214,921 $ 12,151,843 $ 9,809,492 Steel products 1,849,218 1,514,086 5,056,299 4,093,136 Raw materials 491,374 441,110 1,563,253 1,257,437 $ 6,742,202 $ 5,170,117 $ 18,771,395 $ 15,160,065 Intercompany sales: Steel mills $ 1,055,093 $ 764,977 $ 3,019,199 $ 2,182,582 Steel products 56,185 30,828 142,862 87,193 Raw materials 2,923,196 2,333,840 8,687,408 6,971,831 Corporate/eliminations (4,034,474 ) (3,129,645 ) (11,849,469 ) (9,241,606 ) $ — $ — $ — $ — Earnings (loss) before income taxes and noncontrolling interests: Steel mills $ 1,095,360 $ 405,097 $ 2,617,647 $ 1,628,800 Steel products 138,688 86,908 380,268 237,463 Raw materials (29,074 ) 9,957 180,468 102,575 Corporate/eliminations (282,472 ) (131,357 ) (826,268 ) (541,122 ) $ 922,502 $ 370,605 $ 2,352,115 $ 1,427,716 Sept. 29, 2018 Dec. 31, 2017 Segment assets: Steel mills $ 8,764,717 $ 7,671,217 Steel products 4,828,354 4,323,907 Raw materials 3,318,424 3,396,110 Corporate/eliminations 1,051,398 450,024 $ 17,962,893 $ 15,841,258

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 29, 2018
Revenue from Contract with Customer [Abstract]
Schedule of Net Sales Disaggregates by Major Source	Three Months (13 Weeks) Ended September 29, 2018 Nine Months (39 Weeks) Ended September 29, 2018 Steel Mills Steel Raw Total Steel Mills Steel Raw 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. 29, 2018
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 2018 and 2017 are as follows (in thousands, except per share amounts): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 29, 2018 Sept. 30, 2017 Sept. 29, 2018 Sept. 30, 2017 Basic net earnings per share: Basic net earnings $ 676,656 $ 254,850 $ 1,713,988 $ 934,797 Earnings allocated to participating securities (2,807 ) (900 ) (6,707 ) (3,239 ) Net earnings available to common stockholders $ 673,849 $ 253,950 $ 1,707,281 $ 931,558 Average shares outstanding 315,913 320,096 317,928 320,253 Basic net earnings per share $ 2.13 $ 0.79 $ 5.37 $ 2.91 Diluted net earnings per share: Diluted net earnings $ 676,656 $ 254,850 $ 1,713,988 $ 934,797 Earnings allocated to participating securities (2,796 ) (899 ) (6,684 ) (3,233 ) Net earnings available to common stockholders $ 673,860 $ 253,951 $ 1,707,304 $ 931,564 Diluted average shares outstanding: Basic shares outstanding 315,913 320,096 317,928 320,253 Dilutive effect of stock options and other 885 667 954 792 316,798 320,763 318,882 321,045 Diluted net earnings per share $ 2.13 $ 0.79 $ 5.35 $ 2.90
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 2018 and 2017 because their effect would have been anti-dilutive (in thousands, except per share amounts): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Sept. 29, 2018 Sept. 30, 2017 Sept. 29, 2018 Sept. 30, 2017 Anti-dilutive stock options: Weighted-average shares 265 698 89 309 Weighted-average exercise price $ 65.80 $ 59.07 $ 65.80 $ 59.07

Basis of Interim Presentation -

Basis of Interim Presentation - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 29, 2018	Sep. 29, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Amount of increase in consolidated net sales if previous accounting guidance had continued to be used	$ 25.2	$ 58.1
Amount of increase in revenue had previous accounting method been used as a percentage of sales	0.40%	0.30%
Amount of increase in consolidated cost of products sold if previous accounting guidance had continued to be used	$ 25.2	$ 58.1

Inventories - Additional Inform

Inventories - Additional Information (Detail)	Sep. 29, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials and supplies in inventory, percentage	40.00%	42.00%
Finished and semi-finished products in inventory, percentage	60.00%	58.00%

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	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ 9,140,000	$ 9,140,000	$ 8,700,000
Property, plant and equipment, net	5,151,302	5,151,302	$ 5,093,147
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	72,400	72,400
Impairment of assets		110,000
Carrying Value of Third Field of Wells [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 53,300	$ 53,300

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. 29, 2018USD ($)
Goodwill [Line Items]
Balance, beginning of period	$ 2,196,058
Translation	(1,827)
Balance, end of period	2,194,231
Steel Mills [Member]
Goodwill [Line Items]
Balance, beginning of period	745,484
Reclassifications	(153,498)
Balance, end of period	591,986
Steel Products [Member]
Goodwill [Line Items]
Balance, beginning of period	720,997
Translation	(1,827)
Reclassifications	153,498
Balance, end of period	872,668
Raw Materials [Member]
Goodwill [Line Items]
Balance, beginning of period	729,577
Balance, end of period	$ 729,577

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 29, 2018	Dec. 31, 2017	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 31, 2017
Finite And Indefinite Lived Intangible Assets [Line Items]
Impairment of goodwill		$ 0
Intangible asset amortization expense	$ 22,100,000		$ 23,000,000	$ 66,700,000	$ 68,400,000
Future amortization expense, in 2018	88,600,000			88,600,000
Future amortization expense, in 2019	86,700,000			86,700,000
Future amortization expense, in 2020	84,400,000			84,400,000
Future amortization expense, in 2021	83,100,000			83,100,000
Future amortization expense, in 2022	$ 80,800,000			$ 80,800,000
Minimum [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, useful life				5 years		5 years
Maximum [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, useful life				22 years		22 years

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	$ 1,659,108	$ 1,659,500
Intangible assets, Accumulated Amortization	811,539	744,854
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	1,419,899	1,420,224
Intangible assets, Accumulated Amortization	695,613	641,089
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	176,402	176,471
Intangible assets, Accumulated Amortization	85,022	77,208
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	62,807	62,805
Intangible assets, Accumulated Amortization	$ 30,904	$ 26,557

Equity Investments - Additional

Equity Investments - Additional Information (Detail) $ in Thousands, € in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 29, 2018USD ($)Sheet	Sep. 30, 2017USD ($)	Sep. 29, 2018EUR (€)	Dec. 31, 2017USD ($)	Dec. 31, 2017EUR (€)
Schedule of Equity Method Investments [Line Items]
Equity method investment	$ 858,000		$ 858,000			$ 750,100
Distributions from affiliates			29,325	$ 48,037
Amortization expense due to fair value step-up			66,684	68,394
NuMit LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	$ 330,900		$ 330,900			321,400
Equity method investment, ownership percentage	50.00%		50.00%		50.00%
Period used for lag basis, in months			1 month
Distributions from affiliates			$ 28,300	47,000
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 investment	$ 272,200		$ 272,200			285,900
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	$ 113,600		$ 113,600
Basis difference due to the step-up to fair value of certain assets and liabilities	158,600		158,600
Step-up to fair value of equity method investment, portion related to identification of goodwill			89,500
Amortization expense due to fair value step-up	2,300	$ 2,300	7,100	$ 6,600
Due from related parties, noncurrent	40,600		$ 40,600		€ 35	41,900	€ 35
Notes receivable, related parties, interest rate			0.84%
Interest rate per year in excess of Euribor as of date of the notes			1.00%
Equity method investments notes payable with parent company, maturity date			Jan. 31, 2022
Nucor JFE [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	$ 128,800		$ 128,800			71,100
Equity method investment, ownership percentage	50.00%		50.00%		50.00%
Period used for lag basis, in months			1 month
Facility A [Member] | Duferdofin Nucor S.r.l. [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments credit facilities, amount	$ 185,800		$ 185,800		€ 160
Total amount outstanding under equity method investments credit facilities	$ 172,500		$ 172,500		€ 148.5	$ 146,700	€ 122.5
Guarantor obligation percentage of exposure in case of default	50.00%		50.00%		50.00%
Line of credit facility, maturity period			Apr. 16, 2021

Current Liabilities - Additiona

Current Liabilities - Additional Information (Detail) - USD ($) $ in Millions	Sep. 29, 2018	Dec. 31, 2017
Liabilities, Current [Abstract]
Book overdrafts	$ 161.8	$ 139.2
Dividends payable, current	$ 120.4	$ 121.8

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments		$ 50,000
Total assets	$ 17,962,893	15,841,258
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	1,578,541	594,946
Short-term investments		50,000
Derivative contracts	2,237	479
Total assets	1,580,778	645,425
Derivative contracts	(10,500)	(8,531)
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	1,578,541	594,946
Short-term investments		50,000
Total assets	1,578,541	644,946
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts	2,237	479
Total assets	2,237	479
Derivative contracts	$ (10,500)	$ (8,531)

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	Sep. 29, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair value of short-term and long-term debt, including current maturities	$ 4,480	$ 4,190

Contingencies - Additional Info

Contingencies - Additional Information (Detail) - USD ($) $ in Millions	Sep. 29, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Accrual for environmental loss contingencies, gross	$ 17.5	$ 17.1
Accrued environmental loss contingencies, current	3.2	3.8
Accrued environmental loss contingencies, noncurrent	$ 14.3	$ 13.3

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2018USD ($)shares	Sep. 30, 2017USD ($)	Sep. 29, 2018USD ($)AnniversariesInstallmentshares	Sep. 30, 2017USD ($)	May 08, 2014shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
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	$ 0.4	$ 4.3	$ 7.9
Omnibus Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, common stock available for grant | shares	6		6		13
Inactive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance | shares	1.9		1.9
Restricted Stock [Member] | LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Portion of restricted stock award vesting on anniversary			0.333%
Eligible age of officer for restricted stock award			55 years
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock	$ 53.9		$ 53.9
Weighted-average recognition period for unrecognized compensation expense related to stock (years)	2 years
Number of anniversaries of grant date upon which restricted stock units vest | Anniversaries			3
Installments in which restricted stock units vest and are converted to common stock | Installment			3
Compensation expense	$ 8.5	6.1	$ 46.8	32.2
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
Amount of annual incentive award payment participant can elect to defer			50.00%
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		$ 2
Weighted-average recognition period for unrecognized compensation expense related to stock (years)			1 year 9 months 18 days
Compensation expense	4.9	$ 3.6	$ 14.6	$ 11.1
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	$ 1.9		$ 1.9
Weighted-average recognition period for unrecognized compensation expense related to stock (years)			1 year 10 months 24 days

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. 29, 2018USD ($)$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding at beginning of year, Shares | shares	4,106
Granted, Shares | shares	265
Exercised, Shares | shares	(543)
Canceled, Shares | shares	0
Outstanding at end of year, Shares | shares	3,828
Stock Options exercisable at end of year, Shares | shares	2,112
Outstanding at beginning of year, Weighted - Average Exercise Price | $ / shares	$ 47.96
Granted, Weighted - Average Exercise Price | $ / shares	65.80
Exercised, Weighted - Average Exercise Price | $ / shares	44.33
Canceled, Weighted - Average Exercise Price | $ / shares	0
Outstanding at end of period, Weighted - Average Exercise Price | $ / shares	49.71
Stock options exercisable at end of year, Weighted - Average Exercise Price | $ / shares	$ 45.41
Outstanding at end of period, Weighted - Average Remaining Contractual Life	6 years 8 months 12 days
Stock options exercisable at end of period, Weighted - Average Remaining Contractual Life	5 years 3 months 18 days
Exercised, Aggregate Intrinsic Value | $	$ 12,587
Outstanding at end of period, Aggregate Intrinsic Value | $	53,223
Stock options exercisable at end of period, Aggregate Intrinsic Value | $	$ 38,166

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. 29, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested at beginning of year, Shares | shares	1,071
Granted, Shares | shares	1,013
Vested, Shares | shares	(799)
Canceled, Shares | shares	(11)
Unvested at end of year, Shares | shares	1,274
Unvested at beginning of year, Grant Date Fair Value | $ / shares	$ 52.62
Granted, Grant Date Fair Value | $ / shares	65.80
Vested, Grant Date Fair Value | $ / shares	59.23
Canceled, Grant Date Fair Value | $ / shares	55.02
Unvested at end of year, Grant Date Fair Value | $ / shares	$ 58.93

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Nucor's Restricted Stock Activity under AIP and LTIP (Detail) - Restricted Stock Awards and Units [Member] - AIP and LTIP [Member] shares in Thousands	9 Months Ended
	Sep. 29, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested at beginning of year, Shares | shares	91
Granted, Shares | shares	256
Vested, Shares | shares	(217)
Canceled, Shares | shares	0
Unvested at end of year, Shares | shares	130
Unvested at beginning of year, Grant Date Fair Value | $ / shares	$ 54.50
Granted, Grant Date Fair Value | $ / shares	67.68
Vested, Grant Date Fair Value | $ / shares	64.95
Canceled, Grant Date Fair Value | $ / shares	0
Unvested at end of year, Grant Date Fair Value | $ / shares	$ 62.97

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Employee Benefit Plan [Abstract]
Profit Sharing and Retirement Savings Plan, plan expense	$ 86.4	$ 35.7	$ 226.5	$ 138.2

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. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Interest Revenue (Expense), Net [Abstract]
Interest expense	$ 44,789	$ 47,621	$ 120,308	$ 141,486
Interest income	(7,588)	(4,311)	(16,542)	(9,991)
Interest expense, net	$ 37,201	$ 43,310	$ 103,766	$ 131,495

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Transition tax expense			$ 2.4
Impact on effective tax rate			0.30%
Effective income tax rate	23.40%	28.20%
U.S. corporate federal income tax rate	21.00%	35.00%
Benefit related to return to provision changes in estimate and state tax credits		$ 13.2
Non-current deferred tax liabilities included in deferred credits and other liabilities	$ 382.7		$ 382.7	$ 329.3
Non-current deferred tax assets included in other assets	$ 0.8		$ 0.8	$ 0.6

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Sep. 06, 2018
Stockholders' Equity [Line Items]
Dividends declared per share	$ 0.3800	$ 0.3775	$ 1.1400	$ 1.1325
Nucor-Yamato Steel Company [Member]
Stockholders' Equity [Line Items]
Noncontrolling interest, ownership percentage by parent	51.00%		51.00%
Common Stock [Member]
Stockholders' Equity [Line Items]
Share repurchase program authorized amount	$ 2,000,000,000		$ 2,000,000,000
Common Stock [Member] | Maximum [Member]
Stockholders' Equity [Line Items]
Share repurchase program authorized amount					$ 2,000,000,000

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Change in Stockholder's Equity (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			$ 9,084,788	$ 8,254,708
Total comprehensive income	$ 727,712	$ 341,184	1,780,088	1,085,464
Stock options			28,351	13,300
Issuance of stock under award plans, net of forfeitures			44,304	30,787
Amortization of unearned compensation			1,400	1,000
Treasury stock acquired			(351,392)	(90,305)
Dividends declared			(363,624)	(364,046)
Distributions to noncontrolling interests			(49,494)	(85,094)
Stockholders' equity, end of period	10,174,421	8,845,814	10,174,421	8,845,814
Total Nucor Stockholders' Equity [Member]
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			8,739,036	7,879,865
Total comprehensive income			1,694,062	1,034,784
Stock options			28,351	13,300
Issuance of stock under award plans, net of forfeitures			44,304	30,787
Amortization of unearned compensation			1,400	1,000
Treasury stock acquired			(351,392)	(90,305)
Dividends declared			(363,624)	(364,046)
Stockholders' equity, end of period	9,792,137	8,505,385	9,792,137	8,505,385
Noncontrolling Interests [Member]
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			345,752	374,843
Total comprehensive income			86,026	50,680
Distributions to noncontrolling interests			(49,494)	(85,094)
Stockholders' equity, end of period	$ 382,284	$ 340,429	$ 382,284	$ 340,429

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning Balance, Gains and Losses on Hedging Derivatives	$ (6,800)	$ (300)	$ (2,800)	$ 750
Other comprehensive income (loss) before reclassifications, Gains and Losses on Hedging Derivatives	(1,393)	405	(5,792)	(1,301)
Amounts reclassified from accumulated other comprehensive (loss) income into earnings, Gains and Losses on Hedging Derivatives	193	195	592	851
Net current-period other comprehensive income (loss), Gains and Losses on Hedging Derivatives	(1,200)	600	(5,200)	(450)
Ending Balance, Gains and Losses on Hedging Derivatives	(8,000)	300	(8,000)	300
Beginning Balance, Foreign Currency Gains and losses	(294,864)	(300,212)	(257,513)	(326,170)
Other comprehensive income (loss) before reclassifications, Foreign Currency Gains and Losses	22,625	74,479	(14,726)	100,437
Amounts reclassified from accumulated other comprehensive (loss) income into earnings, Foreign Currency Gains and Losses	0	0	0	0
Net current-period other comprehensive (loss) income, Foreign Currency Gains and losses	22,625	74,479	(14,726)	100,437
Ending Balance, Foreign Currency Gains and losses	(272,239)	(225,733)	(272,239)	(225,733)
Beginning Balance, Adjustment to Early Retiree Medical Plan	5,632	7,577	5,632	7,577
Other comprehensive income (loss) before reclassifications, Adjustment to Early Retiree Medical Plan	0	0	0	0
Amounts reclassified from accumulated other comprehensive (loss) income into earnings, Adjustment to Early Retiree Medical Plan	0	0	0	0
Net current-period other comprehensive (loss) income , Adjustment to Early Retiree Medical Plan	0	0	0	0
Ending Balance, Adjustment to Early Retiree Medical Plan	5,632	7,577	5,632	7,577
Beginning Balance	(296,032)	(292,935)	(254,681)	(317,843)
Other comprehensive income (loss) before reclassifications	21,232	74,884	(20,518)	99,136
Amounts reclassified from accumulated other comprehensive (loss) income into earnings	193	195	592	851
Net current-period other comprehensive income (loss)	21,425	75,079	(19,926)	99,987
Ending Balance	$ (274,607)	$ (217,856)	$ (274,607)	$ (217,856)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Comprehensive Loss (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive (loss) income into earnings, Gains and Losses on Hedging Derivatives	$ 193	$ 195	$ 592	$ 851
AOCI reclassification impact on tax	100	0	200	300
Cost of Products Sold [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive (loss) income into earnings, Gains and Losses on Hedging Derivatives	193	195	592	851
AOCI reclassification impact on tax	$ 100	$ 0	$ 200	$ 300

Segments - Segments (Detail)

Segments - Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 6,742,202	$ 5,170,117	$ 18,771,395	$ 15,160,065
Earnings (loss) before income taxes and noncontrolling interests	922,502	370,605	2,352,115	1,427,716
Total assets	17,962,893		17,962,893		$ 15,841,258
Operating Segments [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	4,401,610	3,214,921	12,151,843	9,809,492
Earnings (loss) before income taxes and noncontrolling interests	1,095,360	405,097	2,617,647	1,628,800
Total assets	8,764,717		8,764,717		7,671,217
Operating Segments [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	1,849,218	1,514,086	5,056,299	4,093,136
Earnings (loss) before income taxes and noncontrolling interests	138,688	86,908	380,268	237,463
Total assets	4,828,354		4,828,354		4,323,907
Operating Segments [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	491,374	441,110	1,563,253	1,257,437
Earnings (loss) before income taxes and noncontrolling interests	(29,074)	9,957	180,468	102,575
Total assets	3,318,424		3,318,424		3,396,110
Corporate and Eliminations Items [Member]
Segment Reporting Information [Line Items]
Net sales	(4,034,474)	(3,129,645)	(11,849,469)	(9,241,606)
Earnings (loss) before income taxes and noncontrolling interests	(282,472)	(131,357)	(826,268)	(541,122)
Total assets	1,051,398		1,051,398		$ 450,024
Intercompany Eliminations [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	1,055,093	764,977	3,019,199	2,182,582
Intercompany Eliminations [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	56,185	30,828	142,862	87,193
Intercompany Eliminations [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	$ 2,923,196	$ 2,333,840	$ 8,687,408	$ 6,971,831

Revenue - Additional Informatio

Revenue - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 29, 2018	Dec. 31, 2017
Revenue from Contract with Customers [Line Items]
Contract with customer, timing of satisfaction of performance obligation and payment	The durations of Nucor's contracts with customers are generally one year or less. Customer payment terms are generally 30 days.
Contract liabilities	$ 85	$ 72.3
Revenue reclassified from contract liabilities	$ 60.8
Steel Mills [Member]
Revenue from Contract with Customers [Line Items]
Contract with customer, timing of satisfaction of performance obligation and payment	One year or less

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. 29, 2018	Sep. 29, 2018
Revenue from Contract with Customers [Line Items]
Revenues	$ 6,742,202	$ 18,771,395
Sheet [Member]
Revenue from Contract with Customers [Line Items]
Revenues	2,051,634	5,692,281
Bar [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,243,890	3,592,475
Structural [Member]
Revenue from Contract with Customers [Line Items]
Revenues	503,733	1,348,987
Plate [Member]
Revenue from Contract with Customers [Line Items]
Revenues	602,353	1,518,100
Tubular Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	357,815	1,040,611
Rebar Fabrication [Member]
Revenue from Contract with Customers [Line Items]
Revenues	412,977	1,133,117
Other Steel Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,078,426	2,882,571
Raw Materials [Member]
Revenue from Contract with Customers [Line Items]
Revenues	491,374	1,563,253
Steel Mills [Member]
Revenue from Contract with Customers [Line Items]
Revenues	4,401,610	12,151,843
Steel Mills [Member] | Sheet [Member]
Revenue from Contract with Customers [Line Items]
Revenues	2,051,634	5,692,281
Steel Mills [Member] | Bar [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,243,890	3,592,475
Steel Mills [Member] | Structural [Member]
Revenue from Contract with Customers [Line Items]
Revenues	503,733	1,348,987
Steel Mills [Member] | Plate [Member]
Revenue from Contract with Customers [Line Items]
Revenues	602,353	1,518,100
Steel Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,849,218	5,056,299
Steel Products [Member] | Tubular Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	357,815	1,040,611
Steel Products [Member] | Rebar Fabrication [Member]
Revenue from Contract with Customers [Line Items]
Revenues	412,977	1,133,117
Steel Products [Member] | Other Steel Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,078,426	2,882,571
Raw Materials [Member]
Revenue from Contract with Customers [Line Items]
Revenues	491,374	1,563,253
Raw Materials [Member] | Raw Materials [Member]
Revenue from Contract with Customers [Line Items]
Revenues	$ 491,374	$ 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. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Basic net earnings	$ 676,656	$ 254,850	$ 1,713,988	$ 934,797
Earnings allocated to participating securities, Basic	(2,807)	(900)	(6,707)	(3,239)
Net earnings available to common stockholders, Basic	$ 673,849	$ 253,950	$ 1,707,281	$ 931,558
Average shares outstanding	315,913	320,096	317,928	320,253
Basic net earnings per share	$ 2.13	$ 0.79	$ 5.37	$ 2.91
Diluted net earnings	$ 676,656	$ 254,850	$ 1,713,988	$ 934,797
Earnings allocated to participating securities, Diluted	(2,796)	(899)	(6,684)	(3,233)
Net earnings available to common stockholders, Diluted	$ 673,860	$ 253,951	$ 1,707,304	$ 931,564
Basic shares outstanding	315,913	320,096	317,928	320,253
Dilutive effect of stock options and other	885	667	954	792
Diluted average shares outstanding	316,798	320,763	318,882	321,045
Diluted net earnings per share	$ 2.13	$ 0.79	$ 5.35	$ 2.90

Earnings Per Share - Anti-dilut

Earnings Per Share - Anti-dilutive Stock Options (Detail) - $ / shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 29, 2017	Sep. 29, 2018	Sep. 29, 2017
Earnings Per Share [Abstract]
Weighted-average shares	265	698	89	309
Weighted-average exercise price	$ 65.80	$ 59.07	$ 65.80	$ 59.07