Goodwill and intangible assets (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Oct. 31, 2011
Estimated Amortization Expense
Estimated Amortization Expense, 2012	$ 10,359
Estimated Amortization Expense, 2013	9,713
Estimated Amortization Expense, 2014	8,881
Estimated Amortization Expense, 2015	8,330
Estimated Amortization Expense, 2016	$ 7,793

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The amount of amortization expense expected to be recognized during the fifth twelve-month period following the balance sheet date.