Condensed Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2010
Revenues	$ 632,826	$ 554,319	$ 373,681	$ 321,955	$ 427,785	$ 394,305	$ 319,675	$ 334,116	$ 1,882,781	$ 1,475,881	$ 1,494,771
Cost of revenues									1,532,095	1,260,770	1,376,558
Selling, general and administrative									287,257	261,355	263,224
Total									1,819,352	1,522,125	1,639,782
Income (loss) from operations									63,429	(46,244)	(145,011)
Other:
Income (loss) from unconsolidated entities									23,592	(1,194)	23,470
Other income - net									25,921	23,403	28,313
Interest expense									0	(1,504)	(22,751)
Expenses related to early retirement of debt										(3,827)	(1,208)
Income (loss) before income tax benefit	60,749	42,952	15,649	(6,408)	15,277	3,888	(31,484)	(17,047)	112,942	(29,366)	(117,187)
Income tax benefit									(374,204)	(69,161)	(113,813)
Net income (loss)	$ 411,417	$ 61,643	$ 16,872	$ (2,786)	$ 15,043	$ 42,108	$ (20,773)	$ 3,417	$ 487,146	$ 39,795	$ (3,374)
Income (loss) per share:
Basic	$ 2.44	$ 0.37	$ 0.10	$ (0.02)	$ 0.09	$ 0.25	$ (0.12)	$ 0.02	$ 2.91	$ 0.24	$ (0.02)
Diluted	$ 2.35	$ 0.36	$ 0.10	$ (0.02)	$ 0.09	$ 0.25	$ (0.12)	$ 0.02	$ 2.86	$ 0.24	$ (0.02)
Weighted average number of shares:
Basic	168,416	167,664	166,994	166,311	166,896	168,075	166,910	166,677	167,346	167,140	165,666
Diluted	174,775	170,229	168,503	166,311	167,525	169,338	166,910	168,121	170,154	168,381	165,666