Purchase Commitments and Contingencies (Details) (USD $) In Billions, unless otherwise specified	Mar. 31, 2012
Unrecorded Unconditional Purchase Obligation [Line Items]
Unrecorded Unconditional Purchase Obligation	$ 6.8
B 737 900ER [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Unrecorded Unconditional Purchase Obligation, Minimum Quantity Required	100
B-787-8 aircraft [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Unrecorded Unconditional Purchase Obligation, Minimum Quantity Required	18
Md90 aircraft [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Unrecorded Unconditional Purchase Obligation, Minimum Quantity Required	13