Summary Consolidated Quarterly Financial Data (Unaudited) Summary Consolidated Quarterly Financial Data (Unaudited) (Details) (USD $) In Thousands, except 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
Quarterly Summary of Income Statement Data [Abstract]
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
Gross Profit	127,088	106,391	66,860	50,347	65,281	54,358	43,321	52,151
Income (loss) before income taxes	60,749	42,952	15,649	(6,408)	15,277	3,888	(31,484)	(17,047)	112,942	(29,366)	(117,187)
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)
Earnings Per Share [Abstract]
Earnings 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)
Earnings Per Share, 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 Outstanding, Diluted [Abstract]
Basic weighted-average shares	168,416,000	167,664,000	166,994,000	166,311,000	166,896,000	168,075,000	166,910,000	166,677,000	167,346,000	167,140,000	165,666,000
Weighted Average Number of Shares Outstanding, Diluted	174,775,000	170,229,000	168,503,000	166,311,000	167,525,000	169,338,000	166,910,000	168,121,000	170,154,000	168,381,000	165,666,000
Summary Consolidated Quarterly Financial Data (Textual) [Abstract]
Incremental Common Shares Attributable to Share-based Payment Arrangements				0			0