Income (Loss) Per Share Information (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	Sep. 05, 2012
Earnings Per Share [Abstract]
Net Income (Loss) Attributable to Parent	$ 411,417	$ 61,643	$ 16,872	$ (2,786)	$ 15,043	$ 42,108	$ (20,773)	$ 3,417	$ 487,146	$ 39,795	$ (3,374)
Interest on Convertible Debt, Net of Tax									78
Net Income (Loss) Available to Common Stockholders, Diluted									$ 487,224	$ 39,795	$ (3,374)
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
Common stock equivalents									1,996,000	1,241,000
Incremental Common Shares Attributable to Conversion of Debt Securities									812,000
Diluted weighted-average shares	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
Common stock equivalents excluded from diluted weighted-average shares due to anti-dilutive effect											1,968,000
Weighted average number of anti-dilutive options									3,646,000	7,936,000	8,401,000
Shares issued under stock incentive and employee stock purchase plans									2,927,000	2,390,000	1,712,000
Incremental Common Shares Attributable to Anti-Dilutive Options											0
Debt Instrument, Interest Rate, Stated Percentage												0.50%
Additional common share if convertible debt exchanged	5,900,000