Commitments and Contingencies - Aircraft-Related Commitments and Financing Arrangements (Details) (USD $)	3 Months Ended					12 Months Ended		12 Months Ended
	Jun. 30, 2012	Dec. 31, 2013 aircraft	Dec. 31, 2012	Dec. 31, 2013 Aircraft and Related Flight Equipment	Dec. 31, 2013 Reservation System Provider	Dec. 31, 2013 Airbus A321 aircraft	Jun. 20, 2013 Airbus A321 aircraft	Dec. 31, 2013 Airbus A321 NEO aircraft	Dec. 31, 2013 Airbus A320 Family aircraft	Dec. 31, 2013 Airbus A320 NEO aircraft	Dec. 31, 2013 V2500 SelectOne Engine aircraft_engine	Dec. 31, 2013 PurePower PW1100G-JM Engine aircraft_engine
Unrecorded Unconditional Purchase Obligation [Line Items]
Number of additional aircraft ordered							20
Number of aircraft not yet delivered under original order									92
Number of aircraft whose aircraft type was converted						10		5
Number of direct leased aircraft ordered from a third party										5
Number of spare aircraft engines ordered											6	9
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months				$ 559,300,000	$ 3,900,000
Committed expenditures, 2015				619,100,000	3,900,000
Committed expenditures, 2016				633,100,000	3,900,000
Committed expenditures, 2017				804,500,000	3,900,000
Committed expenditures, 2018				543,100,000	2,600,000
Committed expenditures, 2019 and beyond				2,197,100,000	0
Number of aircraft with secured financing commitments scheduled for delivery		7
Number of aircraft without secured financing commitments scheduled for delivery		105
Accrued health care claims		2,100,000	1,900,000
Cash payment including interest to pre-IPO stockholders pursuant to tax receivable agreement	27,200,000
Interest included in cash payment to pre-IPO stockholders pursuant to tax receivable agreement	300,000
Tax receivable agreement		5,643,000	7,987,000
Interest accrued related to pre-IPO stockholders pursuant to tax receivable agreement		$ 200,000