Nucor (NUE) 10-Q 12 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Oct. 03, 2015shares
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Oct. 3, 2015
Document Fiscal Year Focus	2,015
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 Common Stock, Shares Outstanding	319,614,898

Consolidated Statements of Earn

Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Oct. 04, 2014	Oct. 03, 2015	Oct. 04, 2014
Income Statement [Abstract]
Net sales	$ 4,225,514	$ 5,701,869	$ 12,982,563	$ 16,101,388
Costs, expenses and other:
Cost of products sold	3,701,678	5,102,283	11,784,139	14,708,733
Marketing, administrative and other expenses	124,339	152,604	377,492	418,851
Equity in earnings of unconsolidated affiliates	(115)	(2,352)	(550)	(10,028)
Interest expense, net	45,341	45,349	131,944	130,481
Costs, expenses and other, total	3,871,243	5,297,884	12,293,025	15,248,037
Earnings before income taxes and noncontrolling interests	354,271	403,985	689,538	853,351
Provision for income taxes	86,535	129,784	178,166	282,519
Net earnings	267,736	274,201	511,372	570,832
Earnings attributable to noncontrolling interests	40,610	28,754	91,691	67,313
Net earnings attributable to Nucor stockholders	$ 227,126	$ 245,447	$ 419,681	$ 503,519
Net earnings per share:
Basic	$ 0.71	$ 0.76	$ 1.30	$ 1.57
Diluted	$ 0.71	$ 0.76	$ 1.30	$ 1.57
Average shares outstanding:
Basic	320,819	320,023	320,544	319,737
Diluted	320,900	320,337	320,695	320,025
Dividends declared per share	$ 0.3725	$ 0.3700	$ 1.1175	$ 1.1100

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Oct. 04, 2014	Oct. 03, 2015	Oct. 04, 2014
Statement Of Comprehensive Income [Abstract]
Net earnings	$ 267,736	$ 274,201	$ 511,372	$ 570,832
Other comprehensive income (loss):
Net unrealized (loss) income on hedging derivatives, net of income taxes of ($2,300) and $100 for the third quarter of 2015 and 2014, respectively, and ($3,900) and ($900) for the first nine months of 2015 and 2014, respectively	(3,985)	103	(6,717)	(1,530)
Reclassification adjustment for loss on settlement of hedging derivatives included in net income, net of income taxes of $1,000 and $100 for the third quarter of 2015 and 2014, respectively, and $1,800 and $200 for the first nine months of 2015 and 2014, respectively	1,685	197	3,017	430
Foreign currency translation (loss), net of income taxes of $0 for the third quarter of 2015 and 2014, and $0 and ($400) for the first nine months of 2015 and 2014, respectively	(62,903)	(81,689)	(155,203)	(93,321)
Other, net of income taxes of $0 for the third quarter of 2015 and 2014, and $1,500 and $0 for the first nine months of 2015 and 2014, respectively			2,700
Net current-period other comprehensive income (loss)	(65,203)	(81,389)	(156,203)	(94,421)
Comprehensive income	202,533	192,812	355,169	476,411
Comprehensive income attributable to noncontrolling interests	(40,610)	(28,754)	(91,691)	(67,313)
Comprehensive income attributable to Nucor stockholders	$ 161,923	$ 164,058	$ 263,478	$ 409,098

Consolidated Statements of Com4

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Oct. 04, 2014	Oct. 03, 2015	Oct. 04, 2014
Statement Of Comprehensive Income [Abstract]
Net unrealized (loss) income on hedging derivatives, tax effect	$ (2,300)	$ 100	$ (3,900)	$ (900)
Reclassification adjustment for loss on settlement of hedging derivatives included in net earnings, tax effect	1,000	100	1,800	200
Foreign currency translation (loss), tax effect	0	0	0	(400)
Other, tax effect	$ 0	$ 0	$ 1,500	$ 0

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Oct. 03, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 1,895,425	$ 1,024,144
Short-term investments	100,000	100,000
Accounts receivable, net	1,716,356	2,068,298
Inventories, net	2,361,071	2,745,032
Other current assets	392,879	504,414
Total current assets	6,465,731	6,441,888
Property, plant and equipment, net	5,040,902	5,287,639
Goodwill	2,023,788	2,068,664
Other intangible assets, net	793,046	862,093
Other assets	946,001	955,643
Total assets	15,269,468	15,615,927
Current liabilities:
Short-term debt	54,601	207,476
Long-term debt due within one year		16,335
Accounts payable	907,332	993,872
Salaries, wages and related accruals	329,499	352,488
Accrued expenses and other current liabilities	555,979	527,605
Total current liabilities	1,847,411	2,097,776
Long-term debt due after one year	4,360,600	4,360,600
Deferred credits and other liabilities	1,014,116	1,082,433
Total liabilities	7,222,127	7,540,809
Nucor stockholders' equity:
Common stock	151,425	151,237
Additional paid-in capital	1,913,240	1,883,356
Retained earnings	7,438,155	7,378,214
Accumulated other comprehensive loss, net of income taxes	(301,911)	(145,708)
Treasury stock	(1,491,822)	(1,494,629)
Total Nucor stockholders' equity	7,709,087	7,772,470
Noncontrolling interests	338,254	302,648
Total equity	8,047,341	8,075,118
Total liabilities and equity	$ 15,269,468	$ 15,615,927

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Oct. 03, 2015	Oct. 04, 2014
Operating activities:
Net earnings	$ 511,372	$ 570,832
Adjustments:
Depreciation	469,239	486,684
Amortization	55,673	54,127
Stock-based compensation	39,542	40,325
Deferred income taxes	(52,661)	(43,712)
Distributions from affiliates	14,149	11,504
Equity in earnings of unconsolidated affiliates	(550)	(10,028)
Loss on assets	7,700	21,546
Changes in assets and liabilities (exclusive of acquisitions and dispositions):
Accounts receivable	328,671	(418,353)
Inventories	370,445	(80,975)
Accounts payable	(83,396)	84,161
Federal income taxes	113,458	94,999
Salaries, wages and related accruals	(15,993)	65,027
Other operating activities	(350)	49,426
Cash provided by operating activities	1,757,299	925,563
Investing activities:
Capital expenditures	(283,087)	(557,249)
Investment in and advances to affiliates	(41,271)	(94,128)
Repayment of advances to affiliates		26,500
Disposition of plant and equipment	24,996	18,748
Acquisitions (net of cash acquired)	(253)	(38,466)
Purchases of investments	(111,927)	(100,000)
Proceeds from the sale of investments	111,452	27,529
Other investing activities	2,947
Cash used in investing activities	(297,143)	(717,066)
Financing activities:
Net change in short-term debt	(152,529)	11,900
Repayment of long-term debt	(16,300)	(3,300)
Issuance of common stock	423	4,465
Excess tax benefits from stock-based compensation	1,700	3,200
Distributions to noncontrolling interests	(56,085)	(51,401)
Cash dividends	(359,461)	(356,230)
Other financing activities	(1,630)	(1,651)
Cash used in financing activities	(583,882)	(393,017)
Effect of exchange rate changes on cash	(4,993)	(2,787)
Increase (decrease) in cash and cash equivalents	871,281	(187,307)
Cash and cash equivalents - beginning of year	1,024,144	1,483,252
Cash and cash equivalents - end of nine months	1,895,425	1,295,945
Non-cash investing activity:
Change in accrued plant and equipment purchases	$ (14,577)	$ (98,050)

Basis of Interim Presentation

Basis of Interim Presentation	9 Months Ended
	Oct. 03, 2015
Accounting Policies [Abstract]
Basis of Interim Presentation	1. BASIS OF INTERIM PRESENTATION: The information furnished in 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, 2014 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 consolidated financial statements and the notes thereto included in Nucor’s Annual Report on Form 10-K for the fiscal year ended December 31, 2014. Recently Adopted Accounting Pronouncements – In the first quarter of 2015, Nucor adopted new accounting guidance which changes the criteria for determining which disposals can be presented as discontinued operations and modifies related disclosure requirements. This standard is applied prospectively for the Company beginning January 1, 2015. The adoption of this standard did not have a material effect on the consolidated financial statements. Recently Issued Accounting Pronouncements – In May 2014, new accounting guidance was issued that will supersede nearly all existing accounting guidance related to revenue recognition. The new guidance provides that an entity recognizes revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This update also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. In August 2015, new accounting guidance was issued that deferred the effective date of this new accounting guidance by one year. As a result, the amendments are effective for the Company for all annual and interim reporting periods beginning after December 15, 2017. The Company is evaluating adoption methods and the impact it will have on the consolidated financial statements. In August 2014, new accounting guidance was issued that specifies the responsibility that an entity’s management has to evaluate whether there is substantial doubt about the entity’s ability to continue as a going concern. The standard is effective for annual and interim periods beginning after December 15, 2016, and is not expected to have an effect on the Company’s consolidated financial statements. In April 2015, new accounting guidance was issued that requires debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. This new guidance is effective for the Company for all annual and interim periods beginning after December 15, 2015, and is not expected to have a material effect on the Company’s consolidated financial statements. In September 2015, new accounting guidance was issued that requires an acquirer in a business combination to recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The standard is effective for annual and interim periods beginning after December 15, 2015, and is not expected to have a material effect on the Company’s consolidated financial statements.

Accounts Receivable

Accounts Receivable	9 Months Ended
	Oct. 03, 2015
Receivables [Abstract]
Accounts Receivable	2. ACCOUNTS RECEIVABLE: An allowance for doubtful accounts is maintained for estimated losses resulting from the inability of our customers to make required payments. Accounts receivable are stated net of an allowance for doubtful accounts of $37.6 million at October 3, 2015 ($65.4 million at December 31, 2014).

Inventories

Inventories	9 Months Ended
	Oct. 03, 2015
Inventory Disclosure [Abstract]
Inventories	3. INVENTORIES: Inventories consisted of approximately 42% raw materials and supplies and 58% finished and semi-finished products at October 3, 2015 (40% and 60%, respectively, at December 31, 2014). 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. Inventories valued using the last-in, first-out (LIFO) method of accounting represented approximately 47% of total inventories as of October 3, 2015 (43% as of December 31, 2014). If the first-in, first-out (FIFO) method of accounting had been used, inventories would have been $318.4 million higher at October 3, 2015 ($567.4 million higher at December 31, 2014). Use of the lower of cost or market methodology reduced inventories by $12.5 million at October 3, 2015 ($2.7 million at December 31, 2014).

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Oct. 03, 2015
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	4. PROPERTY, PLANT AND EQUIPMENT: Property, plant and equipment is recorded net of accumulated depreciation of $7.60 billion at October 3, 2015 ($7.17 billion at December 31, 2014). Included within property, plant and equipment, net at October 3, 2015, is $20.9 million of assets, net of accumulated depreciation, under a capital lease agreement ($22.8 million at December 31, 2014). The gross amount of property, plant and equipment acquired under the capital lease was $25.4 million, which was not included in capital expenditures on the condensed consolidated statement of cash flows in 2014. Total obligations associated with this capital lease agreement were $21.6 million at October 3, 2015 ($23.2 million at December 31, 2014), of which $2.3 million was classified in accrued expenses and other current liabilities ($2.2 million at December 31, 2014) and $19.3 million was classified in deferred credits and other liabilities ($21.0 million at December 31, 2014). In 2013, one of three iron ore storage domes collapsed at Nucor Steel Louisiana in St. James Parish. As a result, Nucor recorded a partial write-down of assets at the facility, including $21.0 million of property, plant and equipment and $7.0 million of inventory, offset by a $14.0 million insurance receivable that was based on management’s best estimate of probable insurance recoveries. As of October 3, 2015, Nucor has received initial payments of $10.3 million related to the insurance receivable. Nucor finalized its assessment process related to the two remaining storage domes during the third quarter of 2015 and determined that those domes would no longer be utilized. The Company recorded an associated write-down of property, plant and equipment of $19.4 million, offset by an $11.7 million insurance receivable that was based on management’s best estimate of probable insurance recoveries. As of October 3, 2015, the insurance receivable related to the three iron ore storage domes totaled $15.4 million. The net charge associated with the write-down of the two remaining domes of $7.7 million is included in marketing, administrative and other expenses in the condensed consolidated statement of earnings in the third quarter and first nine months of 2015. Included in property plant and equipment within the steel mills segment at October 3, 2015, and December 31, 2014, is approximately $84.1 million related to the anticipated further development activities at the St. James Parish site, the majority of which are engineering designs. Changes to the anticipated development activities at this site could result in full or partial impairment of these capitalized assets.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Oct. 03, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	5. GOODWILL AND OTHER INTANGIBLE ASSETS: The change in the net carrying amount of goodwill for the nine months ended October 3, 2015, by segment is as follows (in thousands): Steel Mills Steel Products Raw Materials Total Balance at December 31, 2014 $ 594,402 $ 744,685 $ 729,577 $ 2,068,664 Translation — (41,108 ) — (41,108 ) Other (3,768 ) — — (3,768 ) Balance at October 3, 2015 $ 590,634 $ 703,577 $ 729,577 $ 2,023,788 Nucor completed its most recent annual goodwill impairment testing during the fourth quarter of 2014 and concluded that 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 impairment testing date. Intangible assets with estimated useful lives of 5 to 22 years are amortized on a straight-line or accelerated basis and are comprised of the following (in thousands): October 3, 2015 December 31, 2014 Gross Accumulated Gross Accumulated Customer relationships $ 1,188,474 $ 501,902 $ 1,199,942 $ 454,353 Trademarks and trade names 156,470 55,442 158,584 48,356 Other 23,031 17,585 22,823 16,547 $ 1,367,975 $ 574,929 $ 1,381,349 $ 519,256 Intangible asset amortization expense for the third quarter of 2015 and 2014 was $18.8 million and $17.9 million, respectively, and was $55.7 million and $54.1 million in the first nine months of 2015 and 2014, respectively. Annual amortization expense is estimated to be $74.2 million in 2015; $70.9 million in 2016; $68.7 million in 2017; $65.9 million in 2018; and $63.4 million in 2019.

Equity Investments

Equity Investments	9 Months Ended
	Oct. 03, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Investments	6. EQUITY INVESTMENTS: The carrying value of our equity investments in domestic and foreign companies was $868.0 million at October 3, 2015, ($872.5 million at December 31, 2014) and is recorded in other assets in the condensed consolidated balance sheets. DUFERDOFIN NUCOR Nucor owns a 50% economic and voting interest in Duferdofin Nucor S.r.l. (Duferdofin Nucor), an Italian steel manufacturer, and accounts for the investment (on a one-month lag basis) under the equity method, as control and risk of loss are shared equally between the members. Nucor’s investment in Duferdofin Nucor at October 3, 2015, was $386.3 million ($412.9 million at December 31, 2014). Nucor’s 50% share of the total net assets of Duferdofin Nucor was $51.7 million at October 3, 2015, resulting in a basis difference of $334.6 million due to the step-up to fair value of certain assets and liabilities attributable to Duferdofin Nucor as well as the identification of goodwill ($270.6 million) and finite-lived intangible assets. This basis difference, excluding the portion attributable to goodwill, is being amortized based on the remaining estimated useful lives of the various underlying net assets, as appropriate. Amortization expense associated with the fair value step-up was $2.2 million and $2.6 million in the third quarter of 2015 and 2014, respectively, and was $6.6 million and $8.0 million in the first nine months of 2015 and 2014, respectively. As of October 3, 2015, Nucor had outstanding notes receivable of €35.0 million ($39.2 million) from Duferdofin Nucor (€35.0 million, or $42.5 million, as of December 31, 2014). The notes receivable bear interest at 1.14% and reset annually on September 30 to the twelve-month Euro Interbank Offered Rate (Euribor) plus 1% per year. The principal amounts are due on January 31, 2019. As of October 3, 2015, and December 31, 2014, the note receivable was classified in other assets in the condensed consolidated balance sheets. Nucor has issued guarantees, the fair values of which are immaterial, for its ownership percentage (50%) of Duferdofin Nucor’s borrowings under Facility A of a Structured Trade Finance Facilities Agreement as well as the Standby Medium Long Term Loan Credit Facility, which mature on April 26, 2016, and April 22, 2016, respectively. The maximum amount Duferdofin Nucor can borrow under Facility A is €122.5 million ($137.2 million at October 3, 2015). As of October 3, 2015, there was €115.0 million ($128.8 million) outstanding under that facility (€107.0 million, or $129.9 million, at December 31, 2014). Subsequent to October 3, 2015, Facility A was amended to extend the maturity date to October 12, 2018. The guarantee under the Standby Medium Long Term Loan Credit Facility was issued in the second quarter of 2014, and, as of October 3, 2015, Duferdofin Nucor had the maximum borrowing amount of €60.0 million ($67.2 million) outstanding under the facility (€60.0 million, or $72.8 million, at December 31, 2014). Subsequent to October 3, 2015, Nucor and its joint-venture partner provided capital contributions to Duferdofin Nucor that were used to pay the outstanding balance of the Standby Medium Long Term Loan Credit Facility, which was also terminated. If Duferdofin Nucor fails to pay when due any amounts for which it is obligated under Facility A or the Standby Medium Long Term Loan Credit Facility, Nucor could be required to pay 50% of such amounts pursuant to and in accordance with the terms of its guarantees. Any indebtedness of Duferdofin Nucor to Nucor is effectively subordinated to the indebtedness of Duferdofin Nucor under both financing agreements. Nucor has not recorded any liability associated with these guarantees. NUMIT Nucor has a 50% economic and voting interest in NuMit LLC (NuMit). NuMit owns 100% of the equity interest in Steel Technologies LLC, an operator of 25 sheet processing facilities located throughout the U.S., Canada and Mexico. Nucor accounts for the investment in NuMit (on a one-month lag basis) under the equity method as control and risk of loss are shared equally between the members. Nucor’s investment in NuMit at October 3, 2015, was $307.4 million ($301.5 million as of December 31, 2014). HUNTER RIDGE Nucor has a 50% economic and voting interest in Hunter Ridge Energy Services LLC (Hunter Ridge). Hunter Ridge provides services for the gathering, separation and compression of energy products including natural gas produced by Nucor’s working interest drilling programs. Nucor accounts for the investment (on a one-month lag basis) under the equity method, as control and risk of loss are shared equally between the members. Nucor’s investment in Hunter Ridge was $136.6 million at October 3, 2015 ($138.6 million at December 31, 2014). Recent declines in natural gas pricing have led to reduced natural gas drilling activity. Sustained or further reductions in natural gas production activity could lead to reduced utilization of the Hunter Ridge assets. We will continue to monitor for potential triggering events that could affect the carrying value of our investment in Hunter Ridge as a result of future market conditions and any changes in business strategy. 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. In the fourth quarter of 2014, Nucor assessed its equity investment in Duferdofin Nucor for impairment 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 and that there was no need for impairment. The assumptions that most significantly affect the fair value determination include projected revenues and the discount rate. Steel market conditions in Europe have continued to be challenging through the third quarter of 2015, and, therefore, 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 business strategy. It is possible that the future performance of Duferdofin Nucor could affect the recorded value of the note receivable the Company has with Duferdofin Nucor and any potential liability associated with the Company’s guarantees of the indebtedness of Duferdofin Nucor as discussed above.

Current Liabilities

Current Liabilities	9 Months Ended
	Oct. 03, 2015
Payables and Accruals [Abstract]
Current Liabilities	7. CURRENT LIABILITIES: Book overdrafts, included in accounts payable in the condensed consolidated balance sheets, were $61.2 million at October 3, 2015 ($107.9 million at December 31, 2014). Dividends payable, included in accrued expenses and other current liabilities in the condensed consolidated balance sheets, were $120.0 million at October 3, 2015 ($119.7 million at December 31, 2014).

Derivatives

Derivatives	9 Months Ended
	Oct. 03, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	8. DERIVATIVES: Nucor periodically uses derivative financial instruments primarily to partially manage its exposure to price risk related to natural gas purchases used in the production process as well as to scrap, copper and aluminum purchased for resale to its customers. In addition, Nucor periodically uses derivatives to partially manage its exposure to changes in interest rates on outstanding debt instruments and uses forward foreign exchange contracts to hedge cash flows associated with certain assets and liabilities, firm commitments and anticipated transactions. Nucor recognizes all derivative instruments in the condensed consolidated balance sheets at fair value. Any resulting changes in fair value are recorded as adjustments to other comprehensive income (loss), net of tax, or recognized in net earnings, as appropriate. At October 3, 2015, natural gas swaps covering approximately 16.1 million MMBTUs (extending through June 2017) were outstanding. The following tables summarize information regarding Nucor’s derivative instruments (in thousands): Fair Value of Derivative Instruments Fair Value at Balance Sheet Location Oct. 3, 2015 Dec. 31, 2014 Asset derivatives not designated as hedging instruments: Commodity contracts Other current assets $ 102 $ 1,856 Foreign exchange contracts Other current assets 175 372 Total asset derivatives not designated as hedging instruments $ 277 $ 2,228 Liability derivatives designated as hedging instruments: Commodity contracts Accrued expenses and other current liabilities $ (13,800 ) $ (6,400 ) Commodity contracts Deferred credits and other liabilities (4,700 ) (6,300 ) Total liability derivatives designated as hedging instruments $ (18,500 ) $ (12,700 ) The Effect of Derivative Instruments on the Condensed Consolidated Statements of Earnings Derivatives Designated as Hedging Instruments Derivatives in Cash Flow Hedging Relationships Statement of Amount of Gain or (Loss), net of tax, Recognized in OCI on Derivatives (Effective Portion) Amount of Gain or (Loss), net of tax, Reclassified from on Derivatives (Effective Portion) Amount of Gain or (Loss), net of tax, Recognized in Earnings on Derivatives (Ineffective Portion) Three Months (13 Weeks) Ended Three Months (13 Weeks) Ended Three Months (13 Weeks) Ended Oct. 3, 2015 Oct. 4, 2014 Oct. 3, 2015 Oct. 4, 2014 Oct. 3, 2015 Oct. 4, 2014 Commodity contracts Cost of products sold $ (3,985) $ 103 $ (1,685 ) $ (197 ) $ — $ — . Derivatives in Cash Flow Hedging Relationships Statement of Amount of Gain or (Loss), net of tax, Recognized in OCI on Derivatives (Effective Portion) Amount of Gain or (Loss), net of tax, Reclassified from on Derivatives (Effective Portion) Amount of Gain or net of tax, Recognized in Earnings on Derivatives Nine Months (39 Weeks) Ended Nine Months (39 Weeks) Ended Nine Months (39 Weeks) Ended Oct. 3, Oct. 4, 2014 Oct. 3, Oct. 4, 2014 Oct. 3, Oct. 4, Commodity contracts Cost of products sold $ (6,717) $ (1,530 ) $ (3,017 ) $ (430 ) $ — $ — Derivatives Not Designated as Hedging Instruments Amount of Gain or (Loss) Recognized in Earnings on Derivatives Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Derivatives Not Designated as Hedging Instruments Statement of Earnings Location Oct. 3, Oct. 4, Oct. 3, Oct. 4, Commodity contracts Cost of products sold $ 658 $ 844 $ 2,314 $ 1,282 Foreign exchange contracts Cost of products sold 602 314 1,364 266 Total $ 1,260 $ 1,158 $ 3,678 $ 1,548

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Oct. 03, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	9. FAIR VALUE MEASUREMENTS: The following table summarizes information regarding Nucor’s financial assets and financial liabilities that are measured at fair value as of October 3, 2015, and December 31, 2014 (in thousands). Nucor does not currently have any non-financial assets or liabilities that are measured at fair value on a recurring basis. Fair Value Measurements at Reporting Date Using Description Carrying Quoted Prices Significant Significant As of October 3, 2015 Assets: Cash equivalents $ 1,616,755 $ 1,616,755 $ — Short-term investments 100,000 100,000 — Foreign exchange and commodity contracts 277 — 277 Total assets $ 1,717,032 $ 1,716,755 $ 277 $ — Liabilities: Commodity contracts $ (18,500 ) $ — $ (18,500 ) $ — As of December 31, 2014 Assets: Cash equivalents $ 861,656 $ 861,656 $ — Short-term investments 100,000 100,000 — Foreign exchange and commodity contracts 2,228 — 2,228 Total assets $ 963,884 $ 961,656 $ 2,228 $ — Liabilities: Commodity contracts $ (12,700 ) $ — $ (12,700 ) $ — Fair value measurements for Nucor’s cash equivalents and short-term investments are classified under Level 1 because such measurements are based on quoted market prices in active markets for identical assets. Our short-term investments are held in similar short-term investment instruments as described in Note 4 to Nucor’s Annual Report on Form 10-K for the year ended December 31, 2014. Fair value measurements for Nucor’s derivatives are classified under Level 2 because such measurements are based on published market prices for similar assets or are estimated based on observable inputs such as interest rates, yield curves, credit risks, spot and future commodity prices, and spot and future exchange rates. The fair value of short-term and long-term debt, including current maturities, was approximately $4.67 billion at October 3, 2015 ($4.97 billion at December 31, 2014). The debt fair value estimates are classified under Level 2 because such estimates are based on readily available market prices of our debt at October 3, 2015, and December 31, 2014, or similar debt with the same maturities, ratings and interest rates.

Contingencies

Contingencies	9 Months Ended
	Oct. 03, 2015
Commitments and Contingencies Disclosure [Abstract]
Contingencies	10. CONTINGENCIES: Nucor is subject to environmental laws and regulations established by federal, state and local authorities and, accordingly, makes provision for the estimated costs of compliance. Of the undiscounted total of $21.4 million of accrued environmental costs at October 3, 2015 ($27.2 million at December 31, 2014), $10.0 million was classified in accrued expenses and other current liabilities ($11.3 million at December 31, 2014) and $11.4 million was classified in deferred credits and other liabilities ($15.9 million at December 31, 2014). Inherent uncertainties exist in these estimates primarily due to unknown conditions, evolving remediation technology and changing governmental regulations and legal standards. Nucor has been named, along with other major steel producers, as a co-defendant in several related antitrust class-action complaints filed by Standard Iron Works and other steel purchasers in the United States District Court for the Northern District of Illinois. The majority of these complaints were filed in September and October of 2008, with two additional complaints being filed in July and December of 2010. Two of these complaints have been voluntarily dismissed and are no longer pending. The plaintiffs allege that from April 1, 2005, through December 31, 2007, eight steel manufacturers, including Nucor, engaged in anticompetitive activities with respect to the production and sale of steel. The plaintiffs seek monetary and other relief on behalf of themselves and a putative class of all purchasers of steel products from the defendants in the U.S. between April 1, 2005, and December 31, 2007. Five of the eight defendants have reached court approved settlements with the plaintiffs. On September 9, 2015, the District Court entered an order ruling on issues of class certification. The Court granted in part, and denied in part, the plaintiffs’ motion, certifying a class solely on the issue of whether defendants engaged in a conspiracy in violation of the antitrust laws, and declining to certify a class on the issues of antitrust impact and damages. We continue to believe the plaintiffs’ claims are without merit and will continue to vigorously defend against them, but we cannot at this time predict the outcome of this litigation or estimate the range of Nucor’s potential exposure and, consequently, have not recorded any reserves or contingencies related to this lawsuit. On March 25, 2014, a jury in the U.S. District Court for the Southern District of Texas returned a verdict against Nucor and its co-defendants in an antitrust lawsuit brought by plaintiff MM Steel, LP, a steel plate service center located in Houston. The jury returned a verdict of $52.0 million in damages against all defendants jointly and severally. On June 1, 2014, pursuant to antitrust laws providing for treble damages, the court awarded a judgment to MM Steel jointly and severally against the defendants in an amount totaling $160.8 million after including costs and attorneys’ fees. As a result of developments since the verdict, including settlements reached by various other parties, the Company believes that its practical estimable exposure has been reduced to approximately $40.0 million. The Company has appealed the judgment to the U.S. Court of Appeals for the Fifth Circuit, and believes that it has valid grounds to have the judgment vacated or reversed. The Company believes that the evidence against Nucor was insufficient to support any finding that Nucor was involved in a horizontal conspiracy. The Company believes that the trial court wrongly excluded relevant testimony of Nucor’s expert witness. The Company believes that the trial court erred in admitting hearsay evidence. Finally, the Company believes that the trial court did not sufficiently instruct the jury on applicable legal principles. As a result, the Company believes that the likelihood that the judgment will be affirmed is not probable, and, accordingly, it has not recorded any reserves or contingencies related to this legal matter. Although we are defending this lawsuit vigorously, its ultimate resolution is uncertain. We are from time to time a party to various other lawsuits, claims and 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 for certain risks that is subject to certain self-insurance limits.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Oct. 03, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	11. STOCK-BASED COMPENSATION: Stock Options – Stock options may be granted to Nucor’s key employees, officers and non-employee directors with exercise prices at 100% of the market value on the date of the grant. The stock options granted are generally exercisable at the end of three years and have a term of 10 years. New shares are issued upon exercise of stock options. A summary of activity under Nucor’s stock option plans for the first nine months of 2015 is as follows (in thousands, except year and per share amounts): Shares Weighted - Weighted - Aggregate Number of shares under option: Outstanding at beginning of year 2,422 $ 42.39 Granted 700 $ 47.59 Exercised (10 ) $ 42.34 $ 66 Canceled (20 ) $ 50.63 Outstanding at October 3, 2015 3,092 $ 43.51 7.5 years $ 1,543 Options exercisable at October 3, 2015 1,531 $ 39.35 6.1 years $ 1,543 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 are not retirement-eligible is recognized on a straight-line basis over the vesting period. Compensation expense for stock options was $0.1 million in the third quarter of both 2015 and 2014, and $7.3 million and $7.7 million in the first nine months of 2015 and 2014, respectively. As of October 3, 2015, unrecognized compensation expense related to options was $1.4 million, which is expected to be recognized over a weighted-average period of 2.4 years. Restricted Stock Units Nucor annually grants restricted stock units (RSUs) to key employees, officers and non-employee directors. The RSUs typically vest and are converted to common stock in three equal installments on each of the first three anniversaries of the grant date. A portion of the RSUs awarded to senior officers vest upon the officer’s retirement. Retirement, for purposes of vesting in these units only, means termination of employment with approval of the Compensation and Executive Development Committee of the Board of Directors after satisfying age and years of service requirements. RSUs granted to non-employee directors are fully vested on the grant date and are payable to the non-employee director in the form of common stock after the termination of the director’s service on the Board of Directors. RSUs granted to employees who are eligible for retirement on the date of 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 are not retirement-eligible is recognized on a straight-line basis over the vesting period. Cash dividend equivalents are paid to participants 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 stock 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 2015 is as follows (shares in thousands): Shares Grant Date Restricted stock units: Unvested at beginning of year 1,012 $ 45.98 Granted 790 $ 47.59 Vested (750 ) $ 44.97 Canceled (13 ) $ 46.32 Unvested at October 3, 2015 1,039 $ 47.93 Shares reserved for future grants (stock options and RSUs) 10,355 Compensation expense for RSUs was $5.4 million and $5.3 million in the third quarter of 2015 and 2014, respectively, and $29.8 million and $27.8 million in the first nine months of 2015 and 2014, respectively. As of October 3, 2015, unrecognized compensation expense related to unvested RSUs was $36.2 million, which is expected to be recognized over a weighted-average period of 2.4 years. Restricted Stock Awards Nucor’s Senior Officers Long-Term Incentive Plan (LTIP) and Annual Incentive Plan (AIP) authorize the award of shares of common stock to officers subject to certain conditions and restrictions. The LTIP provides for the award of shares of restricted common stock at the end of each LTIP performance measurement period at no cost to officers if certain financial performance goals are met during the period. One-third of the LTIP restricted stock award vests upon each of the first three anniversaries of the award date or, if earlier, upon the officer’s attainment of age 55 while employed by Nucor. Although participants are entitled to cash dividends and may vote such awarded shares, the sale or transfer of such shares is limited during the restricted period. The AIP provides for the payment of annual cash incentive awards. An AIP participant may elect, however, to defer payment of up to one-half of an annual incentive award. In such event, the deferred AIP award is converted into common stock units and credited with a deferral incentive, in the form of additional common stock units, equal to 25% of the number of common stock units attributable to the deferred AIP award. Common stock units attributable to deferred AIP awards are fully vested. Common stock units credited as a deferral incentive vest upon the AIP participant’s attainment of age 55 while employed by Nucor. Vested common stock units are paid to AIP participants in the form of shares of common stock following their termination of employment with Nucor. A summary of Nucor’s restricted stock activity under the AIP and the LTIP for the first nine months of 2015 is as follows (shares in thousands): Shares Grant Date Restricted stock awards and units: Unvested at beginning of year 65 $ 48.20 Granted 136 $ 47.07 Vested (134 ) $ 47.11 Canceled — — Unvested at October 3, 2015 67 $ 48.08 Shares reserved for future grants 975 Compensation expense for common stock and common stock units awarded under the AIP and LTIP is recorded over the performance measurement and vesting periods based on the anticipated number and market value of shares of common stock and common stock units to be awarded. Compensation expense for anticipated awards based upon Nucor’s financial performance, exclusive of amounts payable in cash, was $1.8 million in the third quarter of 2014 (none in the third quarter of 2015), and $2.3 million and $4.9 million in the first nine months of 2015 and 2014, respectively. As of October 3, 2015, unrecognized compensation expense related to unvested restricted stock awards was $1.0 million, which is expected to be recognized over a weighted-average period of 1.7 years.

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Oct. 03, 2015
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans	12. 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 $31.4 million and $37.3 million in the third quarter of 2015 and 2014, respectively, and was $63.7 million and $77.5 million in the first nine months of 2015 and 2014, respectively. The related liability for these benefits is included in salaries, wages and related accruals.

Interest Expense (Income)

Interest Expense (Income)	9 Months Ended
	Oct. 03, 2015
Banking and Thrift, Interest [Abstract]
Interest Expense (Income)	13. INTEREST EXPENSE (INCOME): The components of net interest expense are as follows (in thousands): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Oct. 3, 2015 Oct. 4, 2014 Oct. 3, 2015 Oct. 4, 2014 Interest expense $ 46,406 $ 46,624 $ 134,624 $ 134,395 Interest income (1,065 ) (1,275 ) (2,680 ) (3,914 ) Interest expense, net $ 45,341 $ 45,349 $ 131,944 $ 130,481

Income Taxes

Income Taxes	9 Months Ended
	Oct. 03, 2015
Income Tax Disclosure [Abstract]
Income Taxes	14. INCOME TAXES: The effective tax rate for the third quarter of 2015 was 24.4% compared to 32.1% for the third quarter of 2014. The decrease in the effective tax rate for the third quarter of 2015 as compared to the third quarter of 2014 is primarily due to a $10.2 million favorable non-cash out-of-period adjustment to deferred tax balances during the third quarter of 2015, which is not material to the current or any prior periods. The decrease in effective tax rate is also due to the change in relative proportions of net earnings attributable to noncontrolling interests to total pre-tax earnings between the periods and the adjustment of tax expense to previously filed returns. Nucor has substantially concluded U.S. federal income tax matters for years through 2012. The 2013 and 2014 tax years remain open to examination by the Internal Revenue Service (“IRS”). The Canada Revenue Agency is examining the 2012 Canadian returns for Harris Steel Group Inc. and certain related affiliates. The tax years 2009 through 2014 remain open to examination by other major taxing jurisdictions to which Nucor is subject (primarily Canada and other state and local jurisdictions). Current deferred tax assets included in other current assets were $256.6 million at October 3, 2015 ($253.4 million at December 31, 2014). Current deferred tax liabilities included in accrued expenses and other current liabilities were $8.3 million at October 3, 2015 ($13.1 million at December 31, 2014). Non-current deferred tax liabilities included in deferred credits and other liabilities were $729.8 million at October 3, 2015 ($779.3 million at December 31, 2014).

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Oct. 03, 2015
Equity [Abstract]
Stockholders' Equity	15. 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, of which Nucor owns 51% (in thousands): Attributable to Attributable to Total Stockholders’ equity at December 31, 2014 $ 7,772,470 $ 302,648 $ 8,075,118 Total comprehensive income 263,478 91,691 355,169 Stock options 7,707 — 7,707 Issuance of stock under award plans, net of forfeitures 24,572 — 24,572 Amortization of unearned compensation 600 — 600 Dividends declared (359,740 ) — (359,740 ) Distributions to noncontrolling interests — (56,085 ) (56,085 ) Stockholders’ equity at October 3, 2015 $ 7,709,087 $ 338,254 $ 8,047,341 Attributable to Attributable to Total Stockholders’ equity at December 31, 2013 $ 7,645,769 $ 264,509 $ 7,910,278 Total comprehensive income 409,098 67,313 476,411 Stock options 12,132 — 12,132 Issuance of stock under award plans, net of forfeitures 24,242 — 24,242 Amortization of unearned compensation 500 — 500 Dividends declared (356,459 ) — (356,459 ) Distributions to noncontrolling interests — (51,401 ) (51,401 ) Stockholders’ equity at October 4, 2014 $ 7,735,282 $ 280,421 $ 8,015,703

Accumulated Other Comprehensive

Accumulated Other Comprehensive (Loss) Income	9 Months Ended
	Oct. 03, 2015
Text Block [Abstract]
Accumulated Other Comprehensive (Loss) Income	16. ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME: The following tables reflect the changes in accumulated other comprehensive (loss) income by component (in thousands): Three Month (13 Week) Period Ended October 3, 2015 Gains and Losses on Foreign Currency Adjustment to Early Total July 4, 2015 $ (9,400 ) $ (238,568 ) $ 11,260 $ (236,708 ) Other comprehensive income (loss) before reclassifications (3,985 ) (62,903 ) — (66,888 ) Amounts reclassified from accumulated other comprehensive income (loss) into earnings (1) 1,685 — — 1,685 Net current-period other comprehensive income (loss) (2,300 ) (62,903 ) — (65,203 ) October 3, 2015 $ (11,700 ) $ (301,471 ) $ 11,260 $ (301,911 ) Nine Month (39 Week) Period Ended October 3, 2015 Gains and Losses on Foreign Currency Adjustment to Early Total December 31, 2014 $ (8,000 ) $ (148,968 ) $ 11,260 $ (145,708 ) Other comprehensive income (loss) before reclassifications (6,717 ) (155,203 ) — (161,920 ) Amounts reclassified from accumulated other comprehensive income (loss) into earnings (1) 3,017 2,700 — 5,717 Net current-period other comprehensive income (loss) (3,700 ) (152,503 ) — (156,203 ) October 3, 2015 $ (11,700 ) $ (301,471 ) $ 11,260 $ (301,911 ) (1) Includes $1,685 and $3,017 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 2015, respectively. The tax impacts of those reclassifications were $1,000 and $1,800, respectively. Also includes $2,700 of accumulated other comprehensive income reclassifications into marketing, administrative, and other expenses for net losses on translation in the first nine months of 2015 (none in the third quarter of 2015). The tax impact of the reclassification was $1,500 in the first nine months of 2015. Three Month (13 Week) Period Ended October 4, 2014 Gains and Losses on Foreign Currency Adjustment to Early Total July 5, 2014 $ (1,400 ) $ (19,070 ) $ 16,518 $ (3,952 ) Other comprehensive income (loss) before reclassifications 103 (81,689 ) — (81,586 ) Amounts reclassified from accumulated other comprehensive income into earnings (2) 197 — — 197 Net current-period other comprehensive income (loss) 300 (81,689 ) — (81,389 ) October 4, 2014 $ (1,100 ) $ (100,759 ) $ 16,518 $ (85,341 ) Nine Month (39 Week) Period Ended October 4, 2014 Gains and Losses on Foreign Currency Adjustment to Early Total December 31, 2013 $ — $ (7,438 ) $ 16,518 $ 9,080 Other comprehensive (loss) income before reclassifications (1,530 ) (93,321 ) — (94,851 ) Amounts reclassified from accumulated other comprehensive income (loss) into earnings (2) 430 — — 430 Net current-period other comprehensive (loss) income (1,100 ) (93,321 ) — (94,421 ) October 4, 2014 $ (1,100 ) $ (100,759 ) $ 16,518 $ (85,341 ) (2) Includes $197 and $430 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 2014, respectively. The tax impacts of those reclassifications were $100 and $200, respectively.

Segments

Segments	9 Months Ended
	Oct. 03, 2015
Segment Reporting [Abstract]
Segments	17. 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 foundation distributors; steel trading businesses; rebar distribution businesses; and Nucor’s equity method investments in Duferdofin Nucor and NuMit. The steel products segment includes steel joists and joist girders, steel deck, fabricated concrete reinforcing steel, cold finished steel, steel fasteners, metal building systems, steel grating and expanded metal, and wire and wire mesh. The raw materials segment includes DJJ, primarily a scrap broker and processor; Nu-Iron Unlimited and Nucor Steel Louisiana, two facilities that produce DRI used by the steel mills; our natural gas working interests; and Nucor’s equity method investment in Hunter Ridge. 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. During the first six months of 2015, the Company performed certain internal reorganization activities. In connection with this process, the financial information utilized by the Chief Operating Decision Maker when assessing segment performance and making resource allocations was adjusted in a way that affected how certain assets are grouped. This resulted in certain assets being reclassified between the steel mills segment, steel products segment, raw materials segment and corporate/eliminations in order to align with the approach management uses to assess the performance of those segments. The segment data for the comparable periods has also been reclassified in order to conform to the current period presentation. These reclassifications did not have any impact on the consolidated asset balances nor did they impact any segment income statement amounts. Net interest expense, other income, profit sharing expense, stock-based compensation and changes in the LIFO reserve 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, the LIFO reserve and investments in and advances to affiliates. Nucor’s results by segment were as follows (in thousands): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended October 3, 2015 October 4, 2014 October 3, 2015 October 4, 2014 Net sales to external customers: Steel mills $ 2,816,441 $ 3,898,031 $ 8,838,424 $ 11,179,935 Steel products 1,081,047 1,142,043 3,018,077 3,052,135 Raw materials 328,026 661,795 1,126,062 1,869,318 $ 4,225,514 $ 5,701,869 $ 12,982,563 $ 16,101,388 Intercompany sales: Steel mills $ 551,300 $ 797,396 $ 1,703,554 $ 2,248,462 Steel products 26,271 34,215 66,788 82,257 Raw materials 1,689,458 2,492,453 5,210,317 7,463,951 Corporate/eliminations (2,267,029 ) (3,324,064 ) (6,980,659 ) (9,794,670 ) $ — $ — $ — $ — Earnings (loss) before income taxes and noncontrolling interests: Steel mills $ 260,776 $ 502,703 $ 676,404 $ 1,188,638 Steel products 96,167 63,890 199,261 108,222 Raw materials (43,177 ) (19,321 ) (122,778 ) (20,597 ) Corporate/eliminations 40,505 (143,287 ) (63,349 ) (422,912 ) $ 354,271 $ 403,985 $ 689,538 $ 853,351 October 3, 2015 Dec. 31, 2014 Segment assets: Steel mills $ 7,851,349 $ 8,528,623 Steel products 2,638,770 2,731,320 Raw materials 3,492,948 3,858,254 Corporate/eliminations 1,286,401 497,730 $ 15,269,468 $ 15,615,927

Earnings Per Share

Earnings Per Share	9 Months Ended
	Oct. 03, 2015
Earnings Per Share [Abstract]
Earnings Per Share	18. EARNINGS PER SHARE: The computations of basic and diluted net earnings per share are as follows (in thousands, except per share amounts): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended October 3, 2015 October 4, 2014 October 3, 2015 October 4, 2014 Basic net earnings per share: Basic net earnings $ 227,126 $ 245,447 $ 419,681 $ 503,519 Earnings allocated to participating securities (737 ) (781 ) (1,498 ) (1,659 ) Net earnings available to common stockholders $ 226,389 $ 244,666 $ 418,183 $ 501,860 Average shares outstanding 320,819 320,023 320,544 319,737 Basic net earnings per share $ 0.71 $ 0.76 $ 1.30 $ 1.57 Diluted net earnings per share: Diluted net earnings $ 227,126 $ 245,447 $ 419,681 $ 503,519 Earnings allocated to participating securities (737 ) (781 ) (1,499 ) (1,659 ) Net earnings available to common stockholders $ 226,389 $ 244,666 $ 418,182 $ 501,860 Diluted average shares outstanding: Basic shares outstanding 320,819 320,023 320,544 319,737 Dilutive effect of stock options and other 81 314 151 288 320,900 320,337 320,695 320,025 Diluted net earnings per share $ 0.71 $ 0.76 $ 1.30 $ 1.57 The following stock options were excluded from the computation of diluted net earnings per share because their effect would have been anti-dilutive (in thousands, except per share amounts): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended October 3, 2015 October 4, 2014 October 3, 2015 October 4, 2014 Anti-dilutive stock options: Weighted average shares 1,641 — 846 — Weighted average exercise price $ 47.45 $ — $ 48.58 $ —

Goodwill and Other Intangible25

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Oct. 03, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Change in Net Carrying Amount of Goodwill by Segment	5. GOODWILL AND OTHER INTANGIBLE ASSETS: The change in the net carrying amount of goodwill for the nine months ended October 3, 2015, by segment is as follows (in thousands): Steel Mills Steel Products Raw Materials Total Balance at December 31, 2014 $ 594,402 $ 744,685 $ 729,577 $ 2,068,664 Translation — (41,108 ) — (41,108 ) Other (3,768 ) — — (3,768 ) Balance at October 3, 2015 $ 590,634 $ 703,577 $ 729,577 $ 2,023,788
Schedule of Intangible Assets	Intangible assets with estimated useful lives of 5 to 22 years are amortized on a straight-line or accelerated basis and are comprised of the following (in thousands): October 3, 2015 December 31, 2014 Gross Accumulated Gross Accumulated Customer relationships $ 1,188,474 $ 501,902 $ 1,199,942 $ 454,353 Trademarks and trade names 156,470 55,442 158,584 48,356 Other 23,031 17,585 22,823 16,547 $ 1,367,975 $ 574,929 $ 1,381,349 $ 519,256

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Oct. 03, 2015
Fair Values of Derivative Instruments	The following tables summarize information regarding Nucor’s derivative instruments (in thousands): Fair Value of Derivative Instruments Fair Value at Balance Sheet Location Oct. 3, 2015 Dec. 31, 2014 Asset derivatives not designated as hedging instruments: Commodity contracts Other current assets $ 102 $ 1,856 Foreign exchange contracts Other current assets 175 372 Total asset derivatives not designated as hedging instruments $ 277 $ 2,228 Liability derivatives designated as hedging instruments: Commodity contracts Accrued expenses and other current liabilities $ (13,800 ) $ (6,400 ) Commodity contracts Deferred credits and other liabilities (4,700 ) (6,300 ) Total liability derivatives designated as hedging instruments $ (18,500 ) $ (12,700 )
Derivatives Designated as Hedging Instrument [Member]
Effect of Derivative Instruments on Condensed Consolidated Statements of Earnings	The Effect of Derivative Instruments on the Condensed Consolidated Statements of Earnings Derivatives Designated as Hedging Instruments Derivatives in Cash Flow Hedging Relationships Statement of Amount of Gain or (Loss), net of tax, Recognized in OCI on Derivatives (Effective Portion) Amount of Gain or (Loss), net of tax, Reclassified from on Derivatives (Effective Portion) Amount of Gain or (Loss), net of tax, Recognized in Earnings on Derivatives (Ineffective Portion) Three Months (13 Weeks) Ended Three Months (13 Weeks) Ended Three Months (13 Weeks) Ended Oct. 3, 2015 Oct. 4, 2014 Oct. 3, 2015 Oct. 4, 2014 Oct. 3, 2015 Oct. 4, 2014 Commodity contracts Cost of products sold $ (3,985) $ 103 $ (1,685 ) $ (197 ) $ — $ — . Derivatives in Cash Flow Hedging Relationships Statement of Amount of Gain or (Loss), net of tax, Recognized in OCI on Derivatives (Effective Portion) Amount of Gain or (Loss), net of tax, Reclassified from on Derivatives (Effective Portion) Amount of Gain or net of tax, Recognized in Earnings on Derivatives Nine Months (39 Weeks) Ended Nine Months (39 Weeks) Ended Nine Months (39 Weeks) Ended Oct. 3, Oct. 4, 2014 Oct. 3, Oct. 4, 2014 Oct. 3, Oct. 4, Commodity contracts Cost of products sold $ (6,717) $ (1,530 ) $ (3,017 ) $ (430 ) $ — $ —
Derivatives Not Designated as Hedging Instrument [Member]
Effect of Derivative Instruments on Condensed Consolidated Statements of Earnings	Derivatives Not Designated as Hedging Instruments Amount of Gain or (Loss) Recognized in Earnings on Derivatives Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Derivatives Not Designated as Hedging Instruments Statement of Earnings Location Oct. 3, Oct. 4, Oct. 3, Oct. 4, Commodity contracts Cost of products sold $ 658 $ 844 $ 2,314 $ 1,282 Foreign exchange contracts Cost of products sold 602 314 1,364 266 Total $ 1,260 $ 1,158 $ 3,678 $ 1,548

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Oct. 03, 2015
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Financial 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 October 3, 2015, and December 31, 2014 (in thousands). Nucor does not currently have any non-financial assets or liabilities that are measured at fair value on a recurring basis. Fair Value Measurements at Reporting Date Using Description Carrying Quoted Prices Significant Significant As of October 3, 2015 Assets: Cash equivalents $ 1,616,755 $ 1,616,755 $ — Short-term investments 100,000 100,000 — Foreign exchange and commodity contracts 277 — 277 Total assets $ 1,717,032 $ 1,716,755 $ 277 $ — Liabilities: Commodity contracts $ (18,500 ) $ — $ (18,500 ) $ — As of December 31, 2014 Assets: Cash equivalents $ 861,656 $ 861,656 $ — Short-term investments 100,000 100,000 — Foreign exchange and commodity contracts 2,228 — 2,228 Total assets $ 963,884 $ 961,656 $ 2,228 $ — Liabilities: Commodity contracts $ (12,700 ) $ — $ (12,700 ) $ —

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Oct. 03, 2015
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 2015 is as follows (in thousands, except year and per share amounts): Shares Weighted - Weighted - Aggregate Number of shares under option: Outstanding at beginning of year 2,422 $ 42.39 Granted 700 $ 47.59 Exercised (10 ) $ 42.34 $ 66 Canceled (20 ) $ 50.63 Outstanding at October 3, 2015 3,092 $ 43.51 7.5 years $ 1,543 Options exercisable at October 3, 2015 1,531 $ 39.35 6.1 years $ 1,543
Summary of Nucor's Restricted Stock Unit Activity	A summary of Nucor’s RSU activity for the first nine months of 2015 is as follows (shares in thousands): Shares Grant Date Restricted stock units: Unvested at beginning of year 1,012 $ 45.98 Granted 790 $ 47.59 Vested (750 ) $ 44.97 Canceled (13 ) $ 46.32 Unvested at October 3, 2015 1,039 $ 47.93 Shares reserved for future grants (stock options and RSUs) 10,355
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 2015 is as follows (shares in thousands): Shares Grant Date Restricted stock awards and units: Unvested at beginning of year 65 $ 48.20 Granted 136 $ 47.07 Vested (134 ) $ 47.11 Canceled — — Unvested at October 3, 2015 67 $ 48.08 Shares reserved for future grants 975

Interest Expense (Income) (Tabl

Interest Expense (Income) (Tables)	9 Months Ended
	Oct. 03, 2015
Banking and Thrift, Interest [Abstract]
Schedule of Components of Interest Expense, Net	The components of net interest expense are as follows (in thousands): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended Oct. 3, 2015 Oct. 4, 2014 Oct. 3, 2015 Oct. 4, 2014 Interest expense $ 46,406 $ 46,624 $ 134,624 $ 134,395 Interest income (1,065 ) (1,275 ) (2,680 ) (3,914 ) Interest expense, net $ 45,341 $ 45,349 $ 131,944 $ 130,481

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Oct. 03, 2015
Equity [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, of which Nucor owns 51% (in thousands): Attributable to Attributable to Total Stockholders’ equity at December 31, 2014 $ 7,772,470 $ 302,648 $ 8,075,118 Total comprehensive income 263,478 91,691 355,169 Stock options 7,707 — 7,707 Issuance of stock under award plans, net of forfeitures 24,572 — 24,572 Amortization of unearned compensation 600 — 600 Dividends declared (359,740 ) — (359,740 ) Distributions to noncontrolling interests — (56,085 ) (56,085 ) Stockholders’ equity at October 3, 2015 $ 7,709,087 $ 338,254 $ 8,047,341 Attributable to Attributable to Total Stockholders’ equity at December 31, 2013 $ 7,645,769 $ 264,509 $ 7,910,278 Total comprehensive income 409,098 67,313 476,411 Stock options 12,132 — 12,132 Issuance of stock under award plans, net of forfeitures 24,242 — 24,242 Amortization of unearned compensation 500 — 500 Dividends declared (356,459 ) — (356,459 ) Distributions to noncontrolling interests — (51,401 ) (51,401 ) Stockholders’ equity at October 4, 2014 $ 7,735,282 $ 280,421 $ 8,015,703

Accumulated Other Comprehensi31

Accumulated Other Comprehensive (Loss) Income (Tables)	9 Months Ended
	Oct. 03, 2015
Text Block [Abstract]
Components of Accumulated Other Comprehensive (Loss) Income	The following tables reflect the changes in accumulated other comprehensive (loss) income by component (in thousands): Three Month (13 Week) Period Ended October 3, 2015 Gains and Losses on Foreign Currency Adjustment to Early Total July 4, 2015 $ (9,400 ) $ (238,568 ) $ 11,260 $ (236,708 ) Other comprehensive income (loss) before reclassifications (3,985 ) (62,903 ) — (66,888 ) Amounts reclassified from accumulated other comprehensive income (loss) into earnings (1) 1,685 — — 1,685 Net current-period other comprehensive income (loss) (2,300 ) (62,903 ) — (65,203 ) October 3, 2015 $ (11,700 ) $ (301,471 ) $ 11,260 $ (301,911 ) Nine Month (39 Week) Period Ended October 3, 2015 Gains and Losses on Foreign Currency Adjustment to Early Total December 31, 2014 $ (8,000 ) $ (148,968 ) $ 11,260 $ (145,708 ) Other comprehensive income (loss) before reclassifications (6,717 ) (155,203 ) — (161,920 ) Amounts reclassified from accumulated other comprehensive income (loss) into earnings (1) 3,017 2,700 — 5,717 Net current-period other comprehensive income (loss) (3,700 ) (152,503 ) — (156,203 ) October 3, 2015 $ (11,700 ) $ (301,471 ) $ 11,260 $ (301,911 ) (1) Includes $1,685 and $3,017 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 2015, respectively. The tax impacts of those reclassifications were $1,000 and $1,800, respectively. Also includes $2,700 of accumulated other comprehensive income reclassifications into marketing, administrative, and other expenses for net losses on translation in the first nine months of 2015 (none in the third quarter of 2015). The tax impact of the reclassification was $1,500 in the first nine months of 2015. Three Month (13 Week) Period Ended October 4, 2014 Gains and Losses on Foreign Currency Adjustment to Early Total July 5, 2014 $ (1,400 ) $ (19,070 ) $ 16,518 $ (3,952 ) Other comprehensive income (loss) before reclassifications 103 (81,689 ) — (81,586 ) Amounts reclassified from accumulated other comprehensive income into earnings (2) 197 — — 197 Net current-period other comprehensive income (loss) 300 (81,689 ) — (81,389 ) October 4, 2014 $ (1,100 ) $ (100,759 ) $ 16,518 $ (85,341 ) Nine Month (39 Week) Period Ended October 4, 2014 Gains and Losses on Foreign Currency Adjustment to Early Total December 31, 2013 $ — $ (7,438 ) $ 16,518 $ 9,080 Other comprehensive (loss) income before reclassifications (1,530 ) (93,321 ) — (94,851 ) Amounts reclassified from accumulated other comprehensive income (loss) into earnings (2) 430 — — 430 Net current-period other comprehensive (loss) income (1,100 ) (93,321 ) — (94,421 ) October 4, 2014 $ (1,100 ) $ (100,759 ) $ 16,518 $ (85,341 ) (2) Includes $197 and $430 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 2014, respectively. The tax impacts of those reclassifications were $100 and $200, respectively.

Segments (Tables)

Segments (Tables)	9 Months Ended
	Oct. 03, 2015
Segment Reporting [Abstract]
Segments	Nucor’s results by segment were as follows (in thousands): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended October 3, 2015 October 4, 2014 October 3, 2015 October 4, 2014 Net sales to external customers: Steel mills $ 2,816,441 $ 3,898,031 $ 8,838,424 $ 11,179,935 Steel products 1,081,047 1,142,043 3,018,077 3,052,135 Raw materials 328,026 661,795 1,126,062 1,869,318 $ 4,225,514 $ 5,701,869 $ 12,982,563 $ 16,101,388 Intercompany sales: Steel mills $ 551,300 $ 797,396 $ 1,703,554 $ 2,248,462 Steel products 26,271 34,215 66,788 82,257 Raw materials 1,689,458 2,492,453 5,210,317 7,463,951 Corporate/eliminations (2,267,029 ) (3,324,064 ) (6,980,659 ) (9,794,670 ) $ — $ — $ — $ — Earnings (loss) before income taxes and noncontrolling interests: Steel mills $ 260,776 $ 502,703 $ 676,404 $ 1,188,638 Steel products 96,167 63,890 199,261 108,222 Raw materials (43,177 ) (19,321 ) (122,778 ) (20,597 ) Corporate/eliminations 40,505 (143,287 ) (63,349 ) (422,912 ) $ 354,271 $ 403,985 $ 689,538 $ 853,351 October 3, 2015 Dec. 31, 2014 Segment assets: Steel mills $ 7,851,349 $ 8,528,623 Steel products 2,638,770 2,731,320 Raw materials 3,492,948 3,858,254 Corporate/eliminations 1,286,401 497,730 $ 15,269,468 $ 15,615,927

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Oct. 03, 2015
Earnings Per Share [Abstract]
Computations of Basic and Diluted Net Earnings Per Share	The computations of basic and diluted net earnings per share are as follows (in thousands, except per share amounts): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended October 3, 2015 October 4, 2014 October 3, 2015 October 4, 2014 Basic net earnings per share: Basic net earnings $ 227,126 $ 245,447 $ 419,681 $ 503,519 Earnings allocated to participating securities (737 ) (781 ) (1,498 ) (1,659 ) Net earnings available to common stockholders $ 226,389 $ 244,666 $ 418,183 $ 501,860 Average shares outstanding 320,819 320,023 320,544 319,737 Basic net earnings per share $ 0.71 $ 0.76 $ 1.30 $ 1.57 Diluted net earnings per share: Diluted net earnings $ 227,126 $ 245,447 $ 419,681 $ 503,519 Earnings allocated to participating securities (737 ) (781 ) (1,499 ) (1,659 ) Net earnings available to common stockholders $ 226,389 $ 244,666 $ 418,182 $ 501,860 Diluted average shares outstanding: Basic shares outstanding 320,819 320,023 320,544 319,737 Dilutive effect of stock options and other 81 314 151 288 320,900 320,337 320,695 320,025 Diluted net earnings per share $ 0.71 $ 0.76 $ 1.30 $ 1.57
Anti-Dilutive Stock Options	The following stock options were excluded from the computation of diluted net earnings per share because their effect would have been anti-dilutive (in thousands, except per share amounts): Three Months (13 Weeks) Ended Nine Months (39 Weeks) Ended October 3, 2015 October 4, 2014 October 3, 2015 October 4, 2014 Anti-dilutive stock options: Weighted average shares 1,641 — 846 — Weighted average exercise price $ 47.45 $ — $ 48.58 $ —

Accounts Receivable - Additiona

Accounts Receivable - Additional Information (Detail) - USD ($) $ in Millions	Oct. 03, 2015	Dec. 31, 2014
Accounts Receivable, Net [Abstract]
Allowance for doubtful accounts receivable	$ 37.6	$ 65.4

Inventories - Additional Inform

Inventories - Additional Information (Detail) - USD ($) $ in Millions	Oct. 03, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Raw materials and supplies in inventory, percentage	42.00%	40.00%
Finished and semi-finished products in inventory, percentage	58.00%	60.00%
Inventories valued using the last-in, first-out	47.00%	43.00%
Increased value of inventory if FIFO method had been used	$ 318.4	$ 567.4
Lower of cost or market adjustments	$ 12.5	$ 2.7

Property, Plant and Equipment -

Property, Plant and Equipment - Additional information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 03, 2015	Oct. 04, 2014	Oct. 03, 2015	Oct. 04, 2014	Dec. 31, 2013	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ 7,600,000		$ 7,600,000			$ 7,170,000
Property, plant and equipment net of accumulated depreciation, under a capital lease agreement	20,900		20,900			22,800
Gross property, plant and equipment acquired under capital lease	25,400		25,400
Total obligations associated with capital lease agreement	21,600		21,600			23,200
Capital lease obligations classified in accrued expenses and other current liabilities	2,300		2,300			2,200
Capital lease obligations classified in deferred credits and other liabilities	19,300		19,300			21,000
Initial payments from insurance receivables			10,300
Net charge associated with write-down of two remaining storage domes included in marketing, administrative and other expenses	124,339	$ 152,604	377,492	$ 418,851
Property, plant and equipment, net	5,040,902		5,040,902			5,287,639
First of Three Storage Domes [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment written down					$ 21,000
Inventory written down					7,000
Insurance receivable					$ 14,000
Three Iron Ore Storage Domes [Member]
Property, Plant and Equipment [Line Items]
Insurance receivable	15,400		15,400
Two Remaining Storage Domes [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment written down			19,400
Insurance receivable	11,700		11,700
Net charge associated with write-down of two remaining storage domes included in marketing, administrative and other expenses			7,700
Net fixed assets associated with anticipated further development activities at the St. James Parish Site [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 84,100		$ 84,100			$ 84,100

Goodwill and Other Intangible37

Goodwill and Other Intangible Assets - Schedule of Change in Net Carrying Amount of Goodwill by Segment (Detail) $ in Thousands	9 Months Ended
	Oct. 03, 2015USD ($)
Goodwill [Line Items]
Balance, beginning of period	$ 2,068,664
Translation	(41,108)
Other	(3,768)
Balance, end of period	2,023,788
Steel Mills [Member]
Goodwill [Line Items]
Balance, beginning of period	594,402
Other	(3,768)
Balance, end of period	590,634
Steel Products [Member]
Goodwill [Line Items]
Balance, beginning of period	744,685
Translation	(41,108)
Balance, end of period	703,577
Raw Materials [Member]
Goodwill [Line Items]
Balance, beginning of period	729,577
Balance, end of period	$ 729,577

Goodwill and Other Intangible38

Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended			9 Months Ended
	Oct. 03, 2015	Dec. 31, 2014	Oct. 04, 2014	Oct. 03, 2015	Oct. 04, 2014
Finite And Indefinite Lived Intangible Assets [Line Items]
Impairment of goodwill		$ 0
Intangible asset amortization expense	$ 18,800,000		$ 17,900,000	$ 55,700,000	$ 54,100,000
Future amortization expense, in 2015	74,200,000			74,200,000
Future amortization expense, in 2016	70,900,000			70,900,000
Future amortization expense, in 2017	68,700,000			68,700,000
Future amortization expense, in 2018	65,900,000			65,900,000
Future amortization expense, in 2019	$ 63,400,000			$ 63,400,000
Minimum [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, useful life				5 years
Maximum [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, useful life				22 years

Goodwill and Other Intangible39

Goodwill and Other Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	Oct. 03, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	$ 1,367,975	$ 1,381,349
Intangible assets, Accumulated Amortization	574,929	519,256
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	1,188,474	1,199,942
Intangible assets, Accumulated Amortization	501,902	454,353
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	156,470	158,584
Intangible assets, Accumulated Amortization	55,442	48,356
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	23,031	22,823
Intangible assets, Accumulated Amortization	$ 17,585	$ 16,547

Equity Investments - Additional

Equity Investments - Additional Information (Detail) $ in Thousands, € in Millions	Oct. 03, 2015USD ($)	Oct. 03, 2015USD ($)	Oct. 04, 2014USD ($)	Oct. 03, 2015USD ($)Sheet	Oct. 04, 2014USD ($)	Oct. 03, 2015EUR (€)	Dec. 31, 2014USD ($)	Dec. 31, 2014EUR (€)
Schedule of Equity Method Investments [Line Items]
Equity method investment	$ 868,000	$ 868,000		$ 868,000			$ 872,500
Amortization expense due to fair value step-up				55,673	$ 54,127
Hunter Ridge Energy Services LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	$ 136,600	$ 136,600		$ 136,600			138,600
Period used for lag basis, in months	1 month
Equity method investment, ownership percentage	50.00%	50.00%		50.00%		50.00%
NuMit LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	$ 307,400	$ 307,400		$ 307,400			301,500
Period used for lag basis, in months				1 month
Equity method investment, ownership percentage	50.00%	50.00%		50.00%		50.00%
Steel Technologies LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	100.00%	100.00%		100.00%		100.00%
Number of sheet processing facilities operated by Steel Technologies | Sheet				25
Duferdofin Nucor S.r.l. [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	$ 386,300	$ 386,300		$ 386,300			412,900
Period used for lag basis, in months				1 month
Equity method investment, ownership percentage	50.00%	50.00%		50.00%		50.00%
Equity method investments, share of net assets	$ 51,700	$ 51,700		$ 51,700
Basis difference due to the step-up to fair value of certain assets and liabilities	334,600	334,600		334,600
Step-up to fair value of equity method investment, portion related to identification of goodwill				270,600
Amortization expense due to fair value step-up		2,200	$ 2,600	6,600	$ 8,000
Due from related parties, noncurrent	39,200	39,200		$ 39,200		€ 35	42,500	€ 35
Notes receivable, related parties, interest rate				1.14%
Interest rate per year in excess of Euribor as of date of the notes				1.00%
Equity method investments note payable with parent company, maturity date				Jan. 31, 2019
Facility A [Member] | Duferdofin Nucor S.r.l. [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments credit facilities, amount	137,200	137,200		$ 137,200		122.5
Total amount outstanding under equity method investments credit facilities	$ 128,800	$ 128,800		$ 128,800		€ 115	129,900	107
Line of credit facility, maturity period				Apr. 26, 2016
Guarantor obligation percentage of exposure in case of default	50.00%	50.00%		50.00%		50.00%
Standby Medium Long Term Credit Facility [Member] | Duferdofin Nucor S.r.l. [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments credit facilities, amount	$ 67,200	$ 67,200		$ 67,200		€ 60	72,800	60
Total amount outstanding under equity method investments credit facilities	$ 67,200	$ 67,200		$ 67,200		€ 60	$ 72,800	€ 60
Line of credit facility, maturity period				Apr. 22, 2016
Guarantor obligation percentage of exposure in case of default	50.00%	50.00%		50.00%		50.00%
Structured Trade Finance Facilities [Member] | Facility A [Member] | Duferdofin Nucor S.r.l. [Member]
Schedule of Equity Method Investments [Line Items]
Line of credit facility, maturity period				Oct. 12, 2018

Current Liabilities - Additiona

Current Liabilities - Additional Information (Detail) - USD ($) $ in Millions	Oct. 03, 2015	Dec. 31, 2014
Liabilities, Current [Abstract]
Book overdrafts	$ 61.2	$ 107.9
Dividends payable, current	$ 120	$ 119.7

Derivatives - Additional Inform

Derivatives - Additional Information (Detail) MMBTU in Millions	Oct. 03, 2015MMBTU
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Notional amount of commodity derivatives	16.1

Derivatives - Fair Values of De

Derivatives - Fair Values of Derivative Instruments (Detail) - USD ($) $ in Thousands	Oct. 03, 2015	Dec. 31, 2014
Derivatives Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	$ (18,500)	$ (12,700)
Derivatives Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	277	2,228
Commodity Contracts [Member] | Derivatives Designated as Hedging Instrument [Member] | Accrued Expenses and Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	(13,800)	(6,400)
Commodity Contracts [Member] | Derivatives Designated as Hedging Instrument [Member] | Deferred Credits and Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	(4,700)	(6,300)
Commodity Contracts [Member] | Derivatives Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	102	1,856
Foreign Exchange Contracts [Member] | Derivatives Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	$ 175	$ 372

Derivatives - Effect of Derivat

Derivatives - Effect of Derivative Instruments on Condensed Consolidated Statements of Earnings (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Oct. 04, 2014	Oct. 03, 2015	Oct. 04, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss), net of tax, Recognized in OCI on Derivatives (Effective Portion)	$ (3,985)	$ 103	$ (6,717)	$ (1,530)
Amount of Gain or (Loss), net of tax, Reclassified from Accumulated OCI into Earnings on Derivatives (Effective Portion)	(1,685)	(197)	(3,017)	(430)
Derivatives Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	1,260	1,158	3,678	1,548
Cost of Products Sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss), net of tax, Reclassified from Accumulated OCI into Earnings on Derivatives (Effective Portion)	(1,685)	(197)	(3,017)	(430)
Cost of Products Sold [Member] | Commodity Contracts [Member] | Derivatives Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	658	844	2,314	1,282
Cost of Products Sold [Member] | Commodity Contracts [Member] | Derivatives Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss), net of tax, Recognized in OCI on Derivatives (Effective Portion)	(3,985)	103	(6,717)	(1,530)
Amount of Gain or (Loss), net of tax, Reclassified from Accumulated OCI into Earnings on Derivatives (Effective Portion)	(1,685)	(197)	(3,017)	(430)
Amount of Gain or (Loss) Recognized in Earnings on Derivatives (Ineffective Portion)	0	0	0	0
Cost of Products Sold [Member] | Foreign Exchange Contracts [Member] | Derivatives Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	$ 602	$ 314	$ 1,364	$ 266

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Financial Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Oct. 03, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments	$ 100,000	$ 100,000
Total assets	15,269,468	15,615,927
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	1,616,755	861,656
Short-term investments	100,000	100,000
Foreign exchange and commodity contracts	277	2,228
Total assets	1,717,032	963,884
Commodity contracts	(18,500)	(12,700)
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	1,616,755	861,656
Short-term investments	100,000	100,000
Total assets	1,716,755	961,656
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Foreign exchange and commodity contracts	277	2,228
Total assets	277	2,228
Commodity contracts	$ (18,500)	$ (12,700)

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	Oct. 03, 2015	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair value of short-term and long-term debt, including current maturities	$ 4,670	$ 4,970

Contingencies - Additional Info

Contingencies - Additional Information (Detail) $ in Millions	Jun. 01, 2014USD ($)	Mar. 25, 2014USD ($)	Oct. 03, 2015USD ($)Manufacturers_DistributorsComplaintsDefendant	Dec. 31, 2014USD ($)
Commitments and Contingencies Disclosure [Abstract]
Accrual for environmental loss contingencies, gross			$ 21.4	$ 27.2
Accrued environmental loss contingencies, current			10	11.3
Accrued environmental loss contingencies, noncurrent			$ 11.4	$ 15.9
Steel manufacturers, number of manufacturers | Manufacturers_Distributors			8
Additional complaints being filed in July and December of 2010 | Complaints			2
Complaints that are dismissed | Complaints			2
Defendants that have reached court approved settlements with the plaintiffs | Defendant			5
Damages against all defendants jointly and severally	$ 160.8	$ 52
Practical estimable exposure			$ 40

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 03, 2015USD ($)	Oct. 04, 2014USD ($)	Oct. 03, 2015USD ($)AnniversariesInstallment	Oct. 04, 2014USD ($)
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	$ 0.1	$ 0.1	$ 7.3	$ 7.7
Restricted Stock [Member] | LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Portion of restricted stock award vesting on anniversary			33.30%
Eligible age of officer for LTIP 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	36.2		$ 36.2
Weighted-average recognition period for unrecognized compensation expense related to stock (years)			2 years 4 months 24 days
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	5.4	5.3	$ 29.8	27.8
Restricted Stock Units [Member] | AIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
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%
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	1.4		$ 1.4
Weighted-average recognition period for unrecognized compensation expense related to stock (years)			2 years 4 months 24 days
Restricted Stock And Restricted Stock Units [Member] | AIP and LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock	1		$ 1
Weighted-average recognition period for unrecognized compensation expense related to stock (years)			1 year 8 months 12 days
Compensation expense	$ 0	$ 1.8	$ 2.3	$ 4.9

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
	Oct. 03, 2015USD ($)$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding at beginning of year, Shares | shares	2,422
Granted, Shares | shares	700
Exercised, Shares | shares	(10)
Canceled, Shares | shares	(20)
Outstanding at end of year, Shares | shares	3,092
Options exercisable at end of year, Shares | shares	1,531
Outstanding at beginning of year, Weighted - Average Exercise Price	$ 42.39
Granted, Weighted - Average Exercise Price	47.59
Exercised, Weighted - Average Exercise Price	42.34
Canceled, Weighted - Average Exercise Price	50.63
Outstanding at end of period, Weighted - Average Exercise Price	43.51
Options exercisable at end of year, Weighted - Average Exercise Price	$ 39.35
Outstanding at end of period, Weighted - Average Remaining Contractual Life	7 years 6 months
Options exercisable at end of period, Weighted - Average Remaining Contractual Life	6 years 1 month 6 days
Exercised, Aggregate Intrinsic Value | $	$ 66
Outstanding at end of period, Aggregate Intrinsic Value | $	1,543
Options exercisable at end of period, Aggregate Intrinsic Value | $	$ 1,543

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Nucor's Restricted Stock Unit Activity (Detail) shares in Thousands	9 Months Ended
	Oct. 03, 2015$ / sharesshares
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested at beginning of year, Shares	1,012
Granted, Shares	790
Vested, Shares	(750)
Canceled, Shares	(13)
Unvested at end of period, Shares	1,039
Unvested at beginning of year, Grant Date Fair Value | $ / shares	$ 45.98
Granted, Grant Date Fair Value | $ / shares	47.59
Vested, Grant Date Fair Value | $ / shares	44.97
Canceled, Grant Date Fair Value | $ / shares	46.32
Unvested at end of period, Grant Date Fair Value | $ / shares	$ 47.93
Restricted Stock Units and Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future grants	10,355

Stock-Based Compensation - Su51

Stock-Based Compensation - Summary of Nucor's Restricted Stock Activity under AIP and LTIP (Detail) - Restricted Stock And Restricted Stock Units [Member] - AIP and LTIP [Member] shares in Thousands	9 Months Ended
	Oct. 03, 2015$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested at beginning of year, Shares	65
Granted, Shares	136
Vested, Shares	(134)
Canceled, Shares	0
Unvested at end of period, Shares	67
Shares reserved for future grants	975
Unvested at beginning of year, Grant Date Fair Value | $ / shares	$ 48.20
Granted, Grant Date Fair Value | $ / shares	47.07
Vested, Grant Date Fair Value | $ / shares	47.11
Canceled, Grant Date Fair Value | $ / shares	0
Unvested at end of period, Grant Date Fair Value | $ / shares	$ 48.08

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Oct. 04, 2014	Oct. 03, 2015	Oct. 04, 2014
Employee Benefit Plan [Abstract]
Profit Sharing and Retirement Savings Plan, plan expense	$ 31.4	$ 37.3	$ 63.7	$ 77.5

Interest Expense (Income) - Sch

Interest Expense (Income) - Schedule of Components of Net Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Oct. 04, 2014	Oct. 03, 2015	Oct. 04, 2014
Interest Revenue (Expense), Net [Abstract]
Interest expense	$ 46,406	$ 46,624	$ 134,624	$ 134,395
Interest income	(1,065)	(1,275)	(2,680)	(3,914)
Interest expense, net	$ 45,341	$ 45,349	$ 131,944	$ 130,481

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Oct. 03, 2015	Oct. 04, 2014	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Effective income tax rate	24.40%	32.10%
Non-cash gain related to correction of deferred tax liabilities	$ 10.2
Current deferred tax assets	256.6		$ 253.4
Current deferred tax Liabilities	8.3		13.1
Non-current deferred tax liabilities	$ 729.8		$ 779.3

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail)	Oct. 03, 2015
Nucor-Yamato Steel Company [Member]
Stockholders' Equity [Line Items]
Noncontrolling interest, ownership percentage by parent	51.00%

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Changes in Stockholders' Equity (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Oct. 04, 2014	Oct. 03, 2015	Oct. 04, 2014
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			$ 8,075,118	$ 7,910,278
Total comprehensive income	$ 202,533	$ 192,812	355,169	476,411
Stock options			7,707	12,132
Issuance of stock under award plans, net of forfeitures			24,572	24,242
Amortization of unearned compensation			600	500
Dividends declared			(359,740)	(356,459)
Distributions to noncontrolling interests			(56,085)	(51,401)
Stockholders' equity, end of period	8,047,341	8,015,703	8,047,341	8,015,703
Attributable to Nucor Corporation [Member]
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			7,772,470	7,645,769
Total comprehensive income			263,478	409,098
Stock options			7,707	12,132
Issuance of stock under award plans, net of forfeitures			24,572	24,242
Amortization of unearned compensation			600	500
Dividends declared			(359,740)	(356,459)
Stockholders' equity, end of period	7,709,087	7,735,282	7,709,087	7,735,282
Attributable to Noncontrolling Interests [Member]
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			302,648	264,509
Total comprehensive income			91,691	67,313
Distributions to noncontrolling interests			(56,085)	(51,401)
Stockholders' equity, end of period	$ 338,254	$ 280,421	$ 338,254	$ 280,421

Accumulated Other Comprehensi57

Accumulated Other Comprehensive (Loss) Income - Components of Accumulated Other Comprehensive (Loss) Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Oct. 04, 2014	Oct. 03, 2015	Oct. 04, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning Balance, Gains and Losses on Hedging Derivatives	$ (9,400)	$ (1,400)	$ (8,000)
Other comprehensive income (loss) before reclassifications, Gains and Losses on Hedging Derivatives	(3,985)	103	(6,717)	$ (1,530)
Amounts reclassified from accumulated other comprehensive income (loss) into earnings, Gains and Losses on Hedging Derivatives	1,685	197	3,017	430
Net current-period other comprehensive income (loss), Gains and Losses on Hedging Derivatives	(2,300)	300	(3,700)	(1,100)
Ending Balance, Gains and Losses on Hedging Derivatives	(11,700)	(1,100)	(11,700)	(1,100)
Beginning Balance, Foreign Currency Gain (Loss)	(238,568)	(19,070)	(148,968)	(7,438)
Other comprehensive income (loss) before reclassifications, Foreign Currency Gain (Loss)	(62,903)	(81,689)	(155,203)	(93,321)
Amounts reclassified from accumulated other comprehensive income (loss) into earnings, Foreign Currency Gain (Loss)			2,700
Net current-period other comprehensive income (loss), Foreign Currency Gain (Loss)	(62,903)	(81,689)	(152,503)	(93,321)
Ending Balance, Foreign Currency Gain (Loss)	(301,471)	(100,759)	(301,471)	(100,759)
Beginning Balance, Adjustment to Early Retiree Medical Plan	11,260	16,518	11,260	16,518
Other comprehensive income (loss) before reclassifications, Adjustment to Early Retiree Medical Plan	0	0	0	0
Amounts reclassified from accumulated other comprehensive income (loss) into earnings, Adjustment to Early Retiree Medical Plan	0	0	0	0
Net current-period other comprehensive income (loss), Adjustment to Early Retiree Medical Plan	0	0	0	0
Ending Balance, Adjustment to Early Retiree Medical Plan	11,260	16,518	11,260	16,518
Beginning Balance	(236,708)	(3,952)	(145,708)	9,080
Other comprehensive income (loss) before reclassifications	(66,888)	(81,586)	(161,920)	(94,851)
Amounts reclassified from accumulated other comprehensive income (loss) into earnings	1,685	197	5,717	430
Net current-period other comprehensive income (loss)	(65,203)	(81,389)	(156,203)	(94,421)
Ending Balance	$ (301,911)	$ (85,341)	$ (301,911)	$ (85,341)

Accumulated Other Comprehensi58

Accumulated Other Comprehensive (Loss) Income - Components of Accumulated Other Comprehensive (Loss) Income (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Oct. 04, 2014	Oct. 03, 2015	Oct. 04, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss) into earnings, Gains and Losses on Hedging Derivatives	$ 1,685	$ 197	$ 3,017	$ 430
AOCI reclassification impact on tax	1,000	100	1,800	200
Amounts reclassified from accumulated other comprehensive income (loss) into earnings, foreign currency gain (loss)			2,700
Cost of Products Sold [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss) into earnings, Gains and Losses on Hedging Derivatives	1,685	197	3,017	430
AOCI reclassification impact on tax	1,000	$ 100	1,800	$ 200
Marketing Administrative and Other Expenses [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss) into earnings, foreign currency gain (loss)	$ 0		2,700
Amounts reclassified from accumulated other comprehensive income (loss) into earnings, foreign currency gain (loss), tax			$ 1,500

Segments - Segments (Detail)

Segments - Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Oct. 04, 2014	Oct. 03, 2015	Oct. 04, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Net sales	$ 4,225,514	$ 5,701,869	$ 12,982,563	$ 16,101,388
Earnings (loss) before income taxes and noncontrolling interests	354,271	403,985	689,538	853,351
Total assets	15,269,468		15,269,468		$ 15,615,927
Steel Mills [Member]
Segment Reporting Information [Line Items]
Earnings (loss) before income taxes and noncontrolling interests	260,776	502,703	676,404	1,188,638
Total assets	7,851,349		7,851,349		8,528,623
Steel Products [Member]
Segment Reporting Information [Line Items]
Earnings (loss) before income taxes and noncontrolling interests	96,167	63,890	199,261	108,222
Total assets	2,638,770		2,638,770		2,731,320
Raw Materials [Member]
Segment Reporting Information [Line Items]
Earnings (loss) before income taxes and noncontrolling interests	(43,177)	(19,321)	(122,778)	(20,597)
Total assets	3,492,948		3,492,948		3,858,254
Net Sales to External Customers [Member]
Segment Reporting Information [Line Items]
Net sales	4,225,514	5,701,869	12,982,563	16,101,388
Net Sales to External Customers [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	2,816,441	3,898,031	8,838,424	11,179,935
Net Sales to External Customers [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	1,081,047	1,142,043	3,018,077	3,052,135
Net Sales to External Customers [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	328,026	661,795	1,126,062	1,869,318
Intercompany Eliminations [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	551,300	797,396	1,703,554	2,248,462
Intercompany Eliminations [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	26,271	34,215	66,788	82,257
Intercompany Eliminations [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	1,689,458	2,492,453	5,210,317	7,463,951
Intercompany Eliminations [Member] | Corporate/Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	(2,267,029)	(3,324,064)	(6,980,659)	(9,794,670)
Earnings (loss) before income taxes and noncontrolling interests	40,505	$ (143,287)	(63,349)	$ (422,912)
Total assets	$ 1,286,401		$ 1,286,401		$ 497,730

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
	Oct. 03, 2015	Oct. 04, 2014	Oct. 03, 2015	Oct. 04, 2014
Earnings Per Share [Abstract]
Basic net earnings	$ 227,126	$ 245,447	$ 419,681	$ 503,519
Earnings allocated to participating securities, Basic	(737)	(781)	(1,498)	(1,659)
Net earnings available to common stockholders, Basic	$ 226,389	$ 244,666	$ 418,183	$ 501,860
Average shares outstanding	320,819	320,023	320,544	319,737
Basic net earnings per share	$ 0.71	$ 0.76	$ 1.30	$ 1.57
Diluted net earnings	$ 227,126	$ 245,447	$ 419,681	$ 503,519
Earnings allocated to participating securities, Diluted	(737)	(781)	(1,499)	(1,659)
Net earnings available to common stockholders, Diluted	$ 226,389	$ 244,666	$ 418,182	$ 501,860
Basic shares outstanding	320,819	320,023	320,544	319,737
Dilutive effect of stock options and other	81	314	151	288
Diluted average shares outstanding	320,900	320,337	320,695	320,025
Diluted net earnings per share	$ 0.71	$ 0.76	$ 1.30	$ 1.57

Earning Per Share - Anti-Diluti

Earning Per Share - Anti-Dilutive Stock Options (Detail) - $ / shares shares in Thousands	3 Months Ended	9 Months Ended
	Oct. 03, 2015	Oct. 03, 2015
Earnings Per Share [Abstract]
Weighted average shares	1,641	846
Weighted average exercise price	$ 47.45	$ 48.58