Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Net sales	$ 6,889,575	$ 7,656,375	$ 7,666,773
Costs and expenses:
Cost of goods sold	6,227,238	6,939,748	7,037,446
Selling, general and administrative expenses	468,611	481,746	508,916
Impairment of assets	17,270	607	24,466
Gain on sale of cost method investment	(26,088)	0	0
Interest expense	69,608	69,487	69,814
Total costs and expenses	6,756,639	7,491,588	7,640,642
Earnings from continuing operations before income taxes	132,936	164,787	26,131
Income taxes (benefit)	57,979	(45,762)	14,592
Earnings from continuing operations	74,957	210,549	11,539
Earnings (loss) from discontinued operations before income taxes	3,672	(11,906)	(139,195)
Income taxes (benefit)	1,310	(8,847)	1,748
Earnings (loss) from discontinued operations	2,362	(3,059)	(140,943)
Net earnings (loss)	77,319	207,490	(129,404)
Less net earnings attributable to noncontrolling interests	4	6	213
Net earnings (loss) attributable to CMC	$ 77,315	$ 207,484	$ (129,617)
Basic earnings (loss) per share attributable to CMC:
Earnings from continuing operations	$ 0.64	$ 1.82	$ 0.10
Earnings (loss) from discontinued operations	$ 0.02	$ (0.03)	$ (1.23)
Net earnings (loss)	$ 0.66	$ 1.79	$ (1.13)
Diluted earnings (loss) per share attributable to CMC:
Earnings from continuing operations	$ 0.64	$ 1.80	$ 0.09
Earnings (loss) from discontinued operations	$ 0.02	$ (0.02)	$ (1.21)
Net earnings (loss)	$ 0.66	$ 1.78	$ (1.12)