Long-term debt (Details Textuals) (USD $)				1 Months Ended	12 Months Ended		12 Months Ended
	Dec. 09, 2011	Oct. 31, 2011	Oct. 31, 2010	Jun. 30, 2011 Private shelf facility, due 2012-2020 [Member]	Oct. 31, 2011 Senior note, due 2013 [Member] Installment	Oct. 31, 2011 Prior credit facility agreement [Member]	Oct. 31, 2011 Senior notes, due 2005-2011 [Member]	Oct. 31, 2011 Loans Payable with State of Ohio [Member]	Oct. 31, 2011 Cuyahoga County [Member]	Oct. 31, 2011 Private shelf facility [Member] Private shelf facility, due 2012-2020 [Member]
Line of Credit Facility [Line Items]
Maximum borrowings under bank lines of credit	$ 500,000,000	$ 43,305,000	$ 39,710,000			$ 400,000,000
Weighted average life of notes							6 years 6 months
Value of agreement with New York Life Investment Management LLC				150,000,000
Fixed interest rate					4.98%			3.00%	3.50%	2.21%
Duration of repayment								15 years	15 years
Number of installment to repay the loan					1
Period of agreement				3 years
Maximum life of the borrowings				12 years
Average life of the borrowings				10 years
Long Term Debt (Textuals) [Abstract]
Weighted average interest for borrowings		0.54%
Annual maturity of long term debt, 2012		5,664,000
Annual maturity of long term debt, 2013		55,668,000
Annual maturity of long term debt, 2014		10,671,000
Annual maturity of long term debt, 2015		10,675,000
Annual maturity of long term debt, 2016		10,679,000
Private shelf note		$ 75,000,000