Stock-based compensation (Details 4) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Oct. 31, 2011
Summarized activity related to director deferred compensation shares
Number of Shares Outstanding, Beginning Balance	267
Number of Shares, Deferrals	3
Number of Shares, Restricted stock units vested	18
Number of Shares, Dividend equivalents	2
Number of Shares, Distributions	(47)
Number of Shares Outstanding, Ending Balance	243
Weighted Average Grant Date Fair Value, Outstanding, Beginning Balance	$ 16.54
Weighted Average Grant Date Fair Value, Deferrals	$ 48.82
Weighted Average Grant Date Fair Value, Restricted stock units vested	$ 16.55
Weighted Average Grant Date Fair Value, Dividend equivalents	$ 47.99
Weighted Average Grant Date Fair Value, Distributions	$ 15.27
Weighted Average Grant Date Fair Value, Outstanding, Ending Balance	$ 17.51