Commitments and Contingencies Commitments and Contingencies (Tables) (Details)	Mar. 31, 2014 aircraft
Schedule of Future Operating Aircraft Leases [Line Items]
Future Aircraft To Be Received, Remainder of FIscal Year	9
Future Aircraft To Be Received, in Two Years	15
Future Aircraft To Be Received, in Three Years	16
Future Aircraft To Be Received, in Four Years	18
Future Aircraft To Be Received, in Five Years	13
Future Aircraft To Be Received, in Six Years	13
Future Aircraft To Be Received, in Seven Years	13
Future Aircraft To Be Received, in Eight Years	18
Future Aircraft To Be Received	115
Airbus [Member]
Schedule of Future Operating Aircraft Leases [Line Items]
Number of Aircraft without Secured Financing Commitments Scheduled for Delivery (in aircraft)	105
Airbus [Member] | Airbus A320 NEO [Member]
Schedule of Future Operating Aircraft Leases [Line Items]
Future Aircraft To Be Received, in Five Years	6
Future Aircraft To Be Received, in Six Years	3
Future Aircraft To Be Received, in Seven Years	13
Future Aircraft To Be Received, in Eight Years	18
Future Aircraft To Be Received	40
Airbus [Member] | Airbus 320 [Member]
Schedule of Future Operating Aircraft Leases [Line Items]
Future Aircraft To Be Received, Remainder of FIscal Year	9
Future Aircraft To Be Received, in Two Years	8
Future Aircraft To Be Received, in Three Years	3
Future Aircraft To Be Received, in Four Years	8
Future Aircraft To Be Received, in Five Years	2
Future Aircraft To Be Received	30
Airbus [Member] | Airbus A321 [Member]
Schedule of Future Operating Aircraft Leases [Line Items]
Future Aircraft To Be Received, in Two Years	6
Future Aircraft To Be Received, in Three Years	9
Future Aircraft To Be Received, in Four Years	10
Future Aircraft To Be Received, in Five Years	5
Future Aircraft To Be Received	30
Airbus [Member] | Airbus A321 NEO [Member]
Schedule of Future Operating Aircraft Leases [Line Items]
Future Aircraft To Be Received, in Six Years	10
Future Aircraft To Be Received	10
Third Party Lessor [Member] | Airbus A320 NEO [Member]
Schedule of Future Operating Aircraft Leases [Line Items]
Future Aircraft To Be Received, in Two Years	1
Future Aircraft To Be Received, in Three Years	4
Future Aircraft To Be Received	5
Fourth Quarter of 2014 [Member] | Airbus [Member]
Schedule of Future Operating Aircraft Leases [Line Items]
Number of Aircraft without Secured Financing Commitments Scheduled for Delivery (in aircraft)	4
2015 [Member] | Airbus [Member]
Schedule of Future Operating Aircraft Leases [Line Items]
Number of Aircraft without Secured Financing Commitments Scheduled for Delivery (in aircraft)	11