Segments - Segments (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jul. 01, 2023	Apr. 01, 2023	Dec. 31, 2022	Oct. 01, 2022	Jul. 02, 2022	Apr. 02, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Net sales	$ 7,704,531	$ 8,775,734	$ 9,523,256	$ 8,709,980	$ 8,723,956	$ 10,500,755	$ 11,794,474	$ 10,493,282	$ 34,713,501	$ 41,512,467	$ 36,483,939
Depreciation expense									930,585	826,692	735,406
Amortization expense									237,730	234,942	129,157
Earnings (loss) before income taxes and noncontrolling interests									6,272,757	10,244,844	9,200,858
Total assets	35,340,499				32,479,210				35,340,499	32,479,210	25,823,072
Capital expenditures									2,215,210	1,952,465	1,700,364
Operating Segments [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales									20,092,662	24,189,858	24,145,396
Depreciation expense									610,510	529,005	465,733
Amortization expense									7,829	7,829	7,829
Earnings (loss) before income taxes and noncontrolling interests									3,712,470	7,199,087	9,735,020
Total assets	15,407,266				14,157,229				15,407,266	14,157,229	13,235,463
Capital expenditures									1,440,478	1,453,277	1,336,276
Operating Segments [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales									12,758,939	15,060,328	9,727,943
Depreciation expense									131,189	115,501	99,248
Amortization expense									202,129	199,379	93,160
Earnings (loss) before income taxes and noncontrolling interests									3,443,950	4,093,105	1,291,450
Total assets	10,914,870				12,087,145				10,914,870	12,087,145	7,845,010
Capital expenditures									367,170	267,128	187,152
Operating Segments [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales									1,861,900	2,262,281	2,610,600
Depreciation expense									173,657	171,060	159,886
Amortization expense									27,772	27,734	28,168
Earnings (loss) before income taxes and noncontrolling interests									253,506	496,823	549,956
Total assets	3,546,759				3,383,114				3,546,759	3,383,114	3,870,806
Capital expenditures									352,642	181,680	128,765
Intercompany Eliminations [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales									4,812,479	5,859,367	6,297,688
Intercompany Eliminations [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales									455,816	547,219	360,063
Intercompany Eliminations [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales									12,363,577	13,715,176	15,762,685
Corporate and Eliminations Items [Member]
Segment Reporting Information [Line Items]
Net sales									(17,631,872)	(20,121,762)	(22,420,436)
Earnings (loss) before income taxes and noncontrolling interests									(1,137,169)	(1,544,171)	(2,375,568)
Corporate [Member]
Segment Reporting Information [Line Items]
Depreciation expense									15,229	11,126	10,539
Total assets	$ 5,471,604				$ 2,851,722				5,471,604	2,851,722	871,793
Capital expenditures									$ 54,920	$ 50,380	$ 48,171