Share-Based Compensation Expense (Details 1) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Jul. 31, 2012 Y	Oct. 31, 2011
Summarizes information with respect to stock options outstanding
Range of Exercise Price, Lower (in dollars per share)	$ 0.94
Range of Exercise Price, Upper (in dollars per share)	$ 268
Number of Underlying Shares, Options Outstanding	3,321
Weighted Average, Outstanding Options Remaining Contractual Life (Years)	3.01
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 27.66	$ 30.01
Aggregate Intrinsic Value, Options Outstanding	$ 2,519
Number of Underlying Shares, Vested Options	3,267
Weighted Average, Vested Options Remaining Contractual Life (Years)	2.95
Weighted Average Exercise Price, Vested Options (in dollars per share)	$ 27.93
Aggregate Intrinsic Value, Vested Options	2,246
Range of Exercise Price 0.94 to 16.31 [Member]
Summarizes information with respect to stock options outstanding
Range of Exercise Price, Lower (in dollars per share)	$ 0.94
Range of Exercise Price, Upper (in dollars per share)	$ 16.31
Number of Underlying Shares, Options Outstanding	334
Weighted Average, Outstanding Options Remaining Contractual Life (Years)	5.36
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 8.45
Aggregate Intrinsic Value, Options Outstanding	2,519
Number of Underlying Shares, Vested Options	283
Weighted Average, Vested Options Remaining Contractual Life (Years)	5.07
Weighted Average Exercise Price, Vested Options (in dollars per share)	$ 8.06
Aggregate Intrinsic Value, Vested Options	2,246
Range of Exercise Price 16.52 to 17.29 [Member]
Summarizes information with respect to stock options outstanding
Range of Exercise Price, Lower (in dollars per share)	$ 16.52
Range of Exercise Price, Upper (in dollars per share)	$ 17.29
Number of Underlying Shares, Options Outstanding	393
Weighted Average, Outstanding Options Remaining Contractual Life (Years)	2.95
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 16.68
Aggregate Intrinsic Value, Options Outstanding	0
Number of Underlying Shares, Vested Options	391
Weighted Average, Vested Options Remaining Contractual Life (Years)	2.94
Weighted Average Exercise Price, Vested Options (in dollars per share)	$ 16.68
Aggregate Intrinsic Value, Vested Options	0
Range of Exercise Price 17.43 to 24.50 [Member]
Summarizes information with respect to stock options outstanding
Range of Exercise Price, Lower (in dollars per share)	$ 17.43
Range of Exercise Price, Upper (in dollars per share)	$ 24.5
Number of Underlying Shares, Options Outstanding	534
Weighted Average, Outstanding Options Remaining Contractual Life (Years)	2.79
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 20.47
Aggregate Intrinsic Value, Options Outstanding	0
Number of Underlying Shares, Vested Options	533
Weighted Average, Vested Options Remaining Contractual Life (Years)	2.79
Weighted Average Exercise Price, Vested Options (in dollars per share)	$ 20.47
Aggregate Intrinsic Value, Vested Options	0
Range of Exercise Price 24.69 to 28.28 [Member]
Summarizes information with respect to stock options outstanding
Range of Exercise Price, Lower (in dollars per share)	$ 24.69
Range of Exercise Price, Upper (in dollars per share)	$ 28.28
Number of Underlying Shares, Options Outstanding	409
Weighted Average, Outstanding Options Remaining Contractual Life (Years)	4.24
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 26.99
Aggregate Intrinsic Value, Options Outstanding	0
Number of Underlying Shares, Vested Options	409
Weighted Average, Vested Options Remaining Contractual Life (Years)	4.24
Weighted Average Exercise Price, Vested Options (in dollars per share)	$ 26.99
Aggregate Intrinsic Value, Vested Options	0
Range of Exercise Price 28.61 to 31.43 [Member]
Summarizes information with respect to stock options outstanding
Range of Exercise Price, Lower (in dollars per share)	$ 28.61
Range of Exercise Price, Upper (in dollars per share)	$ 31.43
Number of Underlying Shares, Options Outstanding	269
Weighted Average, Outstanding Options Remaining Contractual Life (Years)	2.84
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 29.75
Aggregate Intrinsic Value, Options Outstanding	0
Number of Underlying Shares, Vested Options	269
Weighted Average, Vested Options Remaining Contractual Life (Years)	2.84
Weighted Average Exercise Price, Vested Options (in dollars per share)	$ 29.75
Aggregate Intrinsic Value, Vested Options	0
Range of Exercise Price 31.71 to 32.55 [Member]
Summarizes information with respect to stock options outstanding
Range of Exercise Price, Lower (in dollars per share)	$ 31.71
Range of Exercise Price, Upper (in dollars per share)	$ 32.55
Number of Underlying Shares, Options Outstanding	512
Weighted Average, Outstanding Options Remaining Contractual Life (Years)	0.57
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 31.72
Aggregate Intrinsic Value, Options Outstanding	0
Number of Underlying Shares, Vested Options	512
Weighted Average, Vested Options Remaining Contractual Life (Years)	0.57
Weighted Average Exercise Price, Vested Options (in dollars per share)	$ 31.72
Aggregate Intrinsic Value, Vested Options	0
Range of Exercise Price 33.00 to 37.10 [Member]
Summarizes information with respect to stock options outstanding
Range of Exercise Price, Lower (in dollars per share)	$ 33
Range of Exercise Price, Upper (in dollars per share)	$ 37.1
Number of Underlying Shares, Options Outstanding	347
Weighted Average, Outstanding Options Remaining Contractual Life (Years)	4.75
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 35.17
Aggregate Intrinsic Value, Options Outstanding	0
Number of Underlying Shares, Vested Options	347
Weighted Average, Vested Options Remaining Contractual Life (Years)	4.75
Weighted Average Exercise Price, Vested Options (in dollars per share)	$ 35.17
Aggregate Intrinsic Value, Vested Options	0
Range Of Exercise Price 37.31 to 47.32 [Member]
Summarizes information with respect to stock options outstanding
Range of Exercise Price, Lower (in dollars per share)	$ 37.31
Range of Exercise Price, Upper (in dollars per share)	$ 47.32
Number of Underlying Shares, Options Outstanding	489
Weighted Average, Outstanding Options Remaining Contractual Life (Years)	2.20
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 44.83
Aggregate Intrinsic Value, Options Outstanding	0
Number of Underlying Shares, Vested Options	489
Weighted Average, Vested Options Remaining Contractual Life (Years)	2.2
Weighted Average Exercise Price, Vested Options (in dollars per share)	$ 44.83
Aggregate Intrinsic Value, Vested Options	0
Range Of Exercise Price 47.53 to 167.09 [Member]
Summarizes information with respect to stock options outstanding
Range of Exercise Price, Lower (in dollars per share)	$ 47.53
Range of Exercise Price, Upper (in dollars per share)	$ 55.79
Number of Underlying Shares, Options Outstanding	32
Weighted Average, Outstanding Options Remaining Contractual Life (Years)	1.07
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 49.35
Aggregate Intrinsic Value, Options Outstanding	0
Number of Underlying Shares, Vested Options	32
Weighted Average, Vested Options Remaining Contractual Life (Years)	1.07
Weighted Average Exercise Price, Vested Options (in dollars per share)	$ 49.35
Aggregate Intrinsic Value, Vested Options	0
Range Of Exercise Price 267.52 to 267.52 [Member]
Summarizes information with respect to stock options outstanding
Range of Exercise Price, Lower (in dollars per share)	$ 268
Range of Exercise Price, Upper (in dollars per share)	$ 268
Number of Underlying Shares, Options Outstanding	2
Weighted Average, Outstanding Options Remaining Contractual Life (Years)	0.15
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 267.52
Aggregate Intrinsic Value, Options Outstanding	0
Number of Underlying Shares, Vested Options	2
Weighted Average, Vested Options Remaining Contractual Life (Years)	0.15
Weighted Average Exercise Price, Vested Options (in dollars per share)	$ 267.52
Aggregate Intrinsic Value, Vested Options	$ 0