Fair Value, Assets Measured On Nonrecurring Basis, Valuation Techniques (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Sep. 30, 2011
Fair Value Measurements Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Equipment under operating leases & Assets held for sale or re-lease, Fair Value	$ 25		$ 111
Aircraft Value Publications [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Equipment under operating leases & Assets held for sale or re-lease, Median	35
Aircraft Value Publications [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Equipment under operating leases & Assets held for sale or re-lease, Range	24	[1]
Aircraft Value Publications [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Equipment under operating leases & Assets held for sale or re-lease, Range	53	[1]
Aircraft Condition Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Equipment under operating leases & Assets held for sale or re-lease, Net	(10)
Aircraft Condition Adjustments [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Equipment under operating leases & Assets held for sale or re-lease, Range	(10)	[2]
Aircraft Condition Adjustments [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Equipment under operating leases & Assets held for sale or re-lease, Range	$ 0	[2]

[1] (1) The range represents the sum of the highest and lowest values for all aircraft subject to fair value measurement, according to the third party aircraft valuation publications that we use in our valuation process.

[2] (2) The negative amount represents the sum for all aircraft subject to fair value measurement, of all downward adjustments based on consideration of individual aircraft attributes and condition. The positive amount represents the sum of all such upward adjustments.