Segments (Schedule Of Segments) (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2011	Jul. 03, 2010	Jul. 02, 2011	Jul. 03, 2010	Dec. 31, 2010
Net sales to external customers	$ 5,107,809	$ 4,195,966	$ 9,941,743	$ 7,850,808
Earnings (loss) before income taxes and noncontrolling interests	477,287	155,573	743,542	219,609
Segment assets	14,733,549		14,733,549		13,921,910
Steel Mills [Member]
Net sales to external customers	3,569,786	2,875,338	7,017,983	5,487,354
Intercompany sales	632,055	437,019	1,216,668	803,770
Earnings (loss) before income taxes and noncontrolling interests	626,840	262,147	939,418	420,647
Segment assets	6,557,391		6,557,391		5,969,846
Steel Products [Member]
Net sales to external customers	875,365	737,693	1,607,504	1,298,728
Intercompany sales	14,233	12,106	24,247	21,182
Earnings (loss) before income taxes and noncontrolling interests	(10,010)	(35,295)	(45,905)	(102,991)
Segment assets	3,025,989		3,025,989		2,835,812
Raw Materials [Member]
Net sales to external customers	555,545	504,080	1,083,008	900,825
Intercompany sales	2,697,521	2,390,344	5,475,127	4,316,327
Earnings (loss) before income taxes and noncontrolling interests	51,922	53,769	109,280	86,553
Segment assets	2,891,957		2,891,957		2,710,544
All Other [Member]
Net sales to external customers	107,113	78,855	233,248	163,901
Intercompany sales	9,926	2,813	16,351	4,740
Earnings (loss) before income taxes and noncontrolling interests	1,074	1,830	4,277	4,568
Segment assets	166,908		166,908		170,174
Corporate/ Eliminations [Member]
Intercompany sales	(3,353,735)	(2,842,282)	(6,732,393)	(5,146,019)
Earnings (loss) before income taxes and noncontrolling interests	(192,539)	(126,878)	(263,528)	(189,168)
Segment assets	$ 2,091,304		$ 2,091,304		$ 2,235,534