Special Charges (Details) (USD $)	0 Months Ended	9 Months Ended		1 Months Ended	3 Months Ended	9 Months Ended		9 Months Ended	21 Months Ended		0 Months Ended	9 Months Ended
	Jun. 02, 2011 debtors	Sep. 30, 2012	Sep. 30, 2011	Jun. 30, 2012 Slot Transaction [Member] aircraft_slot	Sep. 30, 2012 Slot Transaction [Member]	Sep. 30, 2012 July 31, 2012 Secondary Offering [Member]	Jul. 31, 2012 July 31, 2012 Secondary Offering [Member]	Sep. 30, 2012 January 25, 2012 Secondary Offering [Member]	Sep. 30, 2012 January 25, 2012 Secondary Offering [Member]	Jan. 25, 2012 January 25, 2012 Secondary Offering [Member]	Jun. 02, 2011 Initial Public Offering [Member]	Sep. 30, 2011 Initial Public Offering [Member]	Sep. 30, 2011 Initial Public Offering [Member] Indigo Partners, LLC Professional Services Agreement Termination [Member]	Sep. 30, 2011 Initial Public Offering [Member] Repayments to Unaffiliated Debt Holders [Member]
Restructuring Cost and Reserve [Line Items]
Number of permanent air carrier slots transferred				4
Cash received from sale of slots		$ 9,060,000	$ 0	$ 9,060,000
Deferred gain on sale of slots				9,100,000
Gain recognized on sale of slots					9,100,000
Shares sold by certain stockholders in secondary offering (in shares)							9,394,927			12,650,000
Payments of stock issuance costs						800,000		500,000	1,300,000
Common Stock, Shares Held, by Oaktree Capital Management, Post Secondary Offering							0
Stock issuance cost reimbursements								600,000
Shares issued in public offering (in shares)											15,600,000
Incurred costs												$ 2,250,000	$ 1,800,000	$ 500,000
Number of unaffiliated debt holders paid with IPO proceeds (in debtors)	3