Earnings (Loss) Per Share Calculation (Details 1) In Thousands, unless otherwise specified	3 Months Ended
	Jan. 31, 2012	Jan. 31, 2011
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect	61,427	60,776
0.25% Convertible Senior Notes due May 1, 2013 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Interest on convertible notes	0.25%
4.0% Convertible Senior Notes due March 15, 2015 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Interest on convertible notes	4.00%
0.875% Convertible Senior Notes due June 15, 2017 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Interest on convertible notes	0.875%
3.75% Convertible Senior Notes due October 15, 2018 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Interest on convertible notes	3.75%
Shares underlying stock options, restricted stock units and warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect	7,098	6,447
Convertible Senior Notes [Member] | 0.25% Convertible Senior Notes due May 1, 2013 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect	5,470	5,470
Convertible Senior Notes [Member] | 4.0% Convertible Senior Notes due March 15, 2015 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect	18,396	18,396
Convertible Senior Notes [Member] | 0.875% Convertible Senior Notes due June 15, 2017 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect	13,108	13,108
Convertible Senior Notes [Member] | 3.75% Convertible Senior Notes due October 15, 2018 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect	17,355	17,355