Commitments and Contingencies - Commitments (Details) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2012 aircraft_engine	Jun. 30, 2012 aircraft_engine	Dec. 31, 2011
Unrecorded Unconditional Purchase Obligation [Line Items]
Number of spare aircraft engines ordered (in aircraft engine)	3	3
Sale leaseback transaction, deferred gain (loss)	$ (4,900,000)	$ (4,900,000)
Sale leaseback transaction, refund in pre-delivery deposits	27,900,000
Amount of credit card holdback	0	0
Maximum potential exposure to cash holdbacks from credit card processors	159,500,000	159,500,000	115,200,000
Interest included in cash payment to pre-IPO stockholders pursuant to tax receivable agreement		300,000
Cash payment including interest to pre-IPO stockholders pursuant to tax receivable agreement	27,200,000
Aircraft and Related Flight Equipment [Member]
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Committed expenditures, remiander of 2012	96,000,000	96,000,000
Committed expenditures, 2013	323,000,000	323,000,000
Committed expenditures, 2014	348,000,000	348,000,000
Committed expenditures, 2015	520,000,000	520,000,000
Committed expenditures, 2016	510,000,000	510,000,000
Committed expenditures, 2017 and beyond	2,955,000,000	2,955,000,000
Reservation System Provider [Member]
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]
Committed expenditures, remiander of 2012	1,500,000	1,500,000
Committed expenditures, 2013	3,100,000	3,100,000
Committed expenditures, 2014	3,700,000	3,700,000
Committed expenditures, 2015	3,700,000	3,700,000
Committed expenditures, 2016	3,700,000	3,700,000
Committed expenditures, 2017 and beyond	$ 6,200,000	$ 6,200,000
Airbus A320 [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Number of aircraft ordered (in aircraft)	101	101
Number of aircraft in sale and leaseback agreement	5
Airbus A320, current model [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Number of aircraft ordered (in aircraft)	56	56
Airbus A320 NEO [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Number of aircraft ordered (in aircraft)	45	45