Subsequent Events Subsequent Events (Aircraft Purchase Commitments) (Details) (Details)	Jan. 23, 2013	Dec. 31, 2012
Property Subject to or Available for Operating Lease [Line Items]
Aircraft Purchase Commitment Future Minimum Quantity Required	326	184
Year Six and beyond, Lease	0	0
Aircraft Lease Commitment Future Minimum Quantity Required	205	205
Current, Purchase	39	39
Aircraft Lease Commitment Future Minimum Quantity Required Current	20	20
Year Two, Purchase	13	11
Year Two, Lease	50	50
Year Three, Purchase	13	2
Year Three, Lease	50	50
Year Four, Purchase	15	2
Year Four, Lease	45	45
Year Five, Purchase	19	10
Year Five, Lease	40	40
Year Six and beyond, Purchase	227	120
Boeing 737 MAX Aircraft [Member]
Property Subject to or Available for Operating Lease [Line Items]
Aircraft Purchase Commitment Future Minimum Quantity Required	100
Year Six and beyond, Lease	0
Aircraft Lease Commitment Future Minimum Quantity Required	0
Current, Purchase	0
Aircraft Lease Commitment Future Minimum Quantity Required Current	0
Year Two, Purchase	0
Year Two, Lease	0
Year Three, Purchase	0
Year Three, Lease	0
Year Four, Purchase	0
Year Four, Lease	0
Year Five, Purchase	0
Year Five, Lease	0
Year Six and beyond, Purchase	100
Boeing Seven Seven Seven Two Zero Zero Er Aircraft [Member]
Property Subject to or Available for Operating Lease [Line Items]
Aircraft Purchase Commitment Future Minimum Quantity Required		5
Year Six and beyond, Lease		0
Aircraft Lease Commitment Future Minimum Quantity Required		0
Current, Purchase		0
Aircraft Lease Commitment Future Minimum Quantity Required Current		0
Year Two, Purchase		1
Year Two, Lease		0
Year Three, Purchase		2
Year Three, Lease		0
Year Four, Purchase		2
Year Four, Lease		0
Year Five, Purchase		0
Year Five, Lease		0
Year Six and beyond, Purchase		0
Boeing 777-300 ER Aircraft [Member]
Property Subject to or Available for Operating Lease [Line Items]
Aircraft Purchase Commitment Future Minimum Quantity Required	18	13
Year Six and beyond, Lease	0	0
Aircraft Lease Commitment Future Minimum Quantity Required	0	0
Current, Purchase	8	8
Aircraft Lease Commitment Future Minimum Quantity Required Current	0	0
Year Two, Purchase	6	5
Year Two, Lease	0	0
Year Three, Purchase	2	0
Year Three, Lease	0	0
Year Four, Purchase	2	0
Year Four, Lease	0	0
Year Five, Purchase	0	0
Year Five, Lease	0	0
Year Six and beyond, Purchase	0	0
Boeing Seven Eight Seven Family [Member]
Property Subject to or Available for Operating Lease [Line Items]
Aircraft Purchase Commitment Future Minimum Quantity Required	42
Year Six and beyond, Lease	0
Aircraft Lease Commitment Future Minimum Quantity Required	0
Current, Purchase	0
Aircraft Lease Commitment Future Minimum Quantity Required Current	0
Year Two, Purchase	2
Year Two, Lease	0
Year Three, Purchase	11
Year Three, Lease	0
Year Four, Purchase	13
Year Four, Lease	0
Year Five, Purchase	9
Year Five, Lease	0
Year Six and beyond, Purchase	7
Airbus A320 Family [Member]
Property Subject to or Available for Operating Lease [Line Items]
Aircraft Purchase Commitment Future Minimum Quantity Required	0	0
Year Six and beyond, Lease	0	0
Aircraft Lease Commitment Future Minimum Quantity Required	130	130
Current, Purchase	0	0
Aircraft Lease Commitment Future Minimum Quantity Required Current	20	20
Year Two, Purchase	0	0
Year Two, Lease	35	35
Year Three, Purchase	0	0
Year Three, Lease	30	30
Year Four, Purchase	0	0
Year Four, Lease	25	25
Year Five, Purchase	0	0
Year Five, Lease	20	20
Year Six and beyond, Purchase	0	0
NEO Airbus Aircraft [Member]
Property Subject to or Available for Operating Lease [Line Items]
Aircraft Purchase Commitment Future Minimum Quantity Required	130
Year Six and beyond, Lease	0
Aircraft Lease Commitment Future Minimum Quantity Required	0
Current, Purchase	0
Aircraft Lease Commitment Future Minimum Quantity Required Current	0
Year Two, Purchase	0
Year Two, Lease	0
Year Three, Purchase	0
Year Three, Lease	0
Year Four, Purchase	0
Year Four, Lease	0
Year Five, Purchase	10
Year Five, Lease	0
Year Six and beyond, Purchase	120
Boeing 737 Family [Member]
Property Subject to or Available for Operating Lease [Line Items]
Aircraft Purchase Commitment Future Minimum Quantity Required	36	36
Year Six and beyond, Lease	0	0
Aircraft Lease Commitment Future Minimum Quantity Required	75	75
Current, Purchase	31	31
Aircraft Lease Commitment Future Minimum Quantity Required Current	0	0
Year Two, Purchase	5	5
Year Two, Lease	15	15
Year Three, Purchase	0
Year Three, Lease	20	20
Year Four, Purchase	0	0
Year Four, Lease	20	20
Year Five, Purchase	0	0
Year Five, Lease	20	20
Year Six and beyond, Purchase	0	0