Receivables from customers and notes receivable, net Exim Bank Notes Receivable (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Insured short-term notes receivable	$ 10.2
Notes Sold through Participation Agreements	$ 0.8
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Short Term Notes Receivable Outstanding Balance Threshold, Percentage	90.00%
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Short Term Notes Receivable Outstanding Balance Threshold, Percentage	98.00%