Segments - Segments (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Oct. 02, 2021	Jul. 03, 2021	Apr. 03, 2021	Dec. 31, 2020	Oct. 03, 2020	Jul. 04, 2020	Apr. 04, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net sales	$ 10,364,412	$ 10,313,223	$ 8,789,164	$ 7,017,140	$ 5,260,055	$ 4,927,960	$ 4,327,306	$ 5,624,337	$ 36,483,939	$ 20,139,658	$ 22,588,858
Depreciation expense									735,406	702,110	648,911
Amortization expense									129,157	83,356	85,742
Earnings (loss) before income taxes and noncontrolling interests									9,200,858	835,538	1,782,807
Total assets	25,823,072				20,125,394				25,823,072	20,125,394	18,344,666
Capital expenditures									1,700,364	1,527,116	1,512,070
Operating Segments [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales									24,145,396	12,109,307	13,933,950
Depreciation expense									465,733	449,289	401,609
Amortization expense									7,829	7,334	8,624
Earnings (loss) before income taxes and noncontrolling interests									9,735,020	720,151	1,790,694
Total assets	13,235,463				9,708,260				13,235,463	9,708,260	9,283,216
Capital expenditures									1,336,276	1,238,132	1,133,089
Operating Segments [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales									9,727,943	6,623,068	6,990,064
Depreciation expense									99,248	93,184	85,276
Amortization expense									93,160	47,773	49,914
Earnings (loss) before income taxes and noncontrolling interests									1,291,450	690,547	511,145
Total assets	7,845,010				4,461,042				7,845,010	4,461,042	4,610,628
Capital expenditures									187,152	135,512	93,848
Operating Segments [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales									2,610,600	1,407,283	1,664,844
Depreciation expense									159,886	150,474	151,124
Amortization expense									28,168	28,249	27,204
Earnings (loss) before income taxes and noncontrolling interests									549,956	23,621	(28,244)
Total assets	3,870,806				3,324,489				3,870,806	3,324,489	3,316,479
Capital expenditures									128,765	125,213	244,818
Intercompany Eliminations [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales									6,297,688	3,036,790	3,304,437
Intercompany Eliminations [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales									360,063	248,477	233,728
Intercompany Eliminations [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales									15,762,685	8,153,841	8,784,397
Corporate and Eliminations Items [Member]
Segment Reporting Information [Line Items]
Net sales									(22,420,436)	(11,439,108)	(12,322,562)
Earnings (loss) before income taxes and noncontrolling interests									(2,375,568)	(598,781)	(490,788)
Total assets	$ 871,793				$ 2,631,603				871,793	2,631,603	1,134,343
Corporate [Member]
Segment Reporting Information [Line Items]
Depreciation expense									10,539	9,163	10,902
Capital expenditures									$ 48,171	$ 28,259	$ 40,315