Earnings (Loss) Per Share Calculation (Details 1) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect (in shares)	27,309	36,875	45,711	52,065
4.0% Convertible Senior Notes due March 15, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Interest rate on convertible notes	4.00%		4.00%
0.875% Convertible Senior Notes due June 15, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Interest rate on convertible notes	0.875%		0.875%
3.75% Convertible Senior Notes due October 15, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Interest rate on convertible notes	3.75%		3.75%
4.0% Convertible Senior Notes due December 15, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Interest rate on convertible notes	4.00%		4.00%
Shares Underlying Stock Options and Restricted Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect (in shares)	755	1,123	1,534	3,205
Convertible Senior Notes | 4.0% Convertible Senior Notes due March 15, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect (in shares)	0	9,198	4,515	9,198
Convertible Senior Notes | 0.875% Convertible Senior Notes due June 15, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect (in shares)	0	0	13,108	13,108
Convertible Senior Notes | 3.75% Convertible Senior Notes due October 15, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect (in shares)	17,356	17,356	17,356	17,356
Convertible Senior Notes | 4.0% Convertible Senior Notes due December 15, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded due to anti-dilutive effect (in shares)	9,198	9,198	9,198	9,198