Segments - Segments (Detail) - USD ($) $ in Millions	3 Months Ended
	Apr. 05, 2025	Mar. 30, 2024	Dec. 31, 2024
Segment Reporting Information [Line Items]
Net sales	$ 7,830	$ 8,137
Total sales	11,780	12,094
Depreciation expense	303	257
Amortization expense	65	59
Cost of products sold	7,225	6,614
Other segment items	56	117
Segment earnings before income taxes and noncontrolling interests	548	1,623
Earnings before income taxes and noncontrolling interests	285	1,225
Capital expenditures	921	659
Total assets	34,699		$ 33,940
Steel Mills [Member]
Segment Reporting Information [Line Items]
Total sales	5,981	6,420
Other segment items	7	19
Segment earnings before income taxes and noncontrolling interests	231	1,102
Steel Products [Member]
Segment Reporting Information [Line Items]
Total sales	2,555	2,654
Other segment items	38	79
Segment earnings before income taxes and noncontrolling interests	288	512
Raw Materials [Member]
Segment Reporting Information [Line Items]
Total sales	3,244	3,020
Other segment items	11	19
Segment earnings before income taxes and noncontrolling interests	29	9
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	7,830	8,137
Cost of products sold	11,176	10,354
Operating Segments [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	4,907	5,169
Depreciation expense	207	170
Amortization expense	2	2
Cost of products sold	5,743	5,299
Capital expenditures	609	401
Total assets	16,952		16,582
Operating Segments [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	2,405	2,517
Depreciation expense	40	35
Amortization expense	56	50
Cost of products sold	2,229	2,063
Capital expenditures	154	99
Total assets	11,287		11,235
Operating Segments [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	518	451
Depreciation expense	51	48
Amortization expense	7	7
Cost of products sold	3,204	2,992
Capital expenditures	118	127
Total assets	3,871		3,656
Intercompany Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	3,950	3,957
Intercompany Eliminations [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	1,074	1,251
Intercompany Eliminations [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	150	137
Intercompany Eliminations [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	2,726	2,569
Corporate and Eliminations Items [Member]
Segment Reporting Information [Line Items]
Net sales	(3,950)	(3,957)
Earnings before income taxes and noncontrolling interests	(263)	(398)
Corporate [Member]
Segment Reporting Information [Line Items]
Depreciation expense	5	4
Capital expenditures	40	$ 32
Total assets	$ 2,589		$ 2,467