Commitments, Contingencies And Guarantees (Aircraft Acquisition Commitments) (Details)	Sep. 30, 2012
Property Subject to or Available for Operating Lease [Line Items]
2012, Purchase	11
2013, Purchase	33
2013, Lease	26
2014, Purchase	10
2014, Lease	50
2015, Purchase	2
2015, Lease	50
2016, Purchase	2
2016, Lease	45
2017 and beyond, Purchase	130
2017 and beyond, Lease	40
Total, Purchase	188
Total, Lease	211
Boeing 737 Family [Member]
Property Subject to or Available for Operating Lease [Line Items]
2012, Purchase	9
2013, Purchase	25
2013, Lease	6
2014, Purchase	5
2014, Lease	15
2015, Purchase
2015, Lease	20
2016, Purchase
2016, Lease	20
2017 and beyond, Purchase
2017 and beyond, Lease	20
Total, Purchase	39	[1]
Total, Lease	81
Boeing Seven Seven Seven Two Zero Zero Er Aircraft [Member]
Property Subject to or Available for Operating Lease [Line Items]
2012, Purchase
2013, Purchase
2013, Lease
2014, Purchase	1
2014, Lease
2015, Purchase	2
2015, Lease
2016, Purchase	2
2016, Lease
2017 and beyond, Purchase
2017 and beyond, Lease
Total, Purchase	5
Total, Lease	0
Boeing 777-300ER Aircraft [Member]
Property Subject to or Available for Operating Lease [Line Items]
2012, Purchase	2
2013, Purchase	8
2013, Lease
2014, Purchase	4
2014, Lease
2015, Purchase
2015, Lease
2016, Purchase
2016, Lease
2017 and beyond, Purchase
2017 and beyond, Lease
Total, Purchase	14
Total, Lease	0
Airbus A320 Family [Member]
Property Subject to or Available for Operating Lease [Line Items]
2012, Purchase
2013, Purchase
2013, Lease	20
2014, Purchase
2014, Lease	35
2015, Purchase
2015, Lease	30
2016, Purchase
2016, Lease	25
2017 and beyond, Purchase
2017 and beyond, Lease	20
Total, Purchase	0
Total, Lease	130
Airbus NEO [Member]
Property Subject to or Available for Operating Lease [Line Items]
2012, Purchase
2013, Purchase
2013, Lease
2014, Purchase
2014, Lease
2015, Purchase
2015, Lease
2016, Purchase
2016, Lease
2017 and beyond, Purchase	130
2017 and beyond, Lease
Total, Purchase	130
Total, Lease	0

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