Spirit Airlines (SAVE) 10-Q 28 Oct 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 21, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Entity Registrant Name	'SPIRIT AIRLINES, INC.	'
Entity Central Index Key	'0001498710	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	72,766,894

Condensed_Statements_Of_Operat

Condensed Statements Of Operations (unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Operating revenues:	'	'	'	'
Passenger	$317,038	$279,499	$873,403	$739,515
Non-ticket	202,731	177,126	583,690	494,886
Total operating revenues	519,769	456,625	1,457,093	1,234,401
Operating expenses:	'	'	'	'
Aircraft fuel	171,584	144,986	474,907	411,903
Salaries, wages and benefits	79,087	66,805	232,776	192,758
Aircraft rent	50,009	42,134	144,618	125,121
Landing fees and other rents	27,735	22,106	77,582	61,508
Distribution	20,202	17,916	58,930	50,874
Maintenance, materials and repairs	19,622	16,908	56,441	43,890
Depreciation and amortization	11,338	8,475	33,803	22,403
Other operating	39,190	38,884	111,045	110,799
Loss on disposal of assets	793	165	1,658	426
Special charges (credits)	18	442	45	488
Total operating expenses	419,578	358,821	1,191,805	1,020,170
Operating income	100,191	97,804	265,288	214,231
Other (income) expense:	'	'	'	'
Interest expense	878	36	1,088	140
Capitalized interest	-878	-36	-1,088	-140
Interest income	-84	-87	-235	-308
Other expense	81	115	1,557	252
Total other (income) expense	-3	28	1,322	-56
Income before income taxes	100,194	97,776	263,966	214,287
Provision for income taxes	33,194	36,673	94,411	80,562
Net income	$67,000	$61,103	$169,555	$133,725
Basic earnings per share (in dollars per share)	$0.92	$0.84	$2.33	$1.84
Diluted earnings per share (in dollars per share)	$0.91	$0.84	$2.31	$1.83

Condensed_Balance_Sheets_unaud

Condensed Balance Sheets (unaudited) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$588,474	$530,631
Accounts receivable, net	26,515	23,246
Deferred income taxes	15,166	16,243
Prepaid expenses and other current assets	73,969	78,955
Total current assets	704,124	649,075
Property and equipment:	'	'
Flight equipment	16,064	9,847
Ground and other equipment	69,676	50,987
Less accumulated depreciation	-32,345	-25,221
Total property and equipment	53,395	35,613
Deposits on flight equipment purchase contracts	269,693	157,669
Aircraft maintenance deposits	194,867	161,484
Deferred heavy maintenance, net	128,304	125,288
Other long-term assets	63,171	51,636
Total assets	1,413,554	1,180,765
Current liabilities:	'	'
Accounts payable	17,954	23,104
Air traffic liability	216,477	167,627
Other current liabilities	160,386	145,262
Total current liabilities	394,817	335,993
Long-term deferred income taxes	47,443	48,916
Deferred credits and other long-term liabilities	25,979	26,739
Shareholders’ equity:	'	'
Common stock	7	7
Additional paid-in-capital	523,476	515,331
Treasury stock	-3,792	-2,291
Retained earnings	425,624	256,070
Total shareholders’ equity	945,315	769,117
Total liabilities and shareholders’ equity	$1,413,554	$1,180,765

Condensed_Statements_Of_Cash_F

Condensed Statements Of Cash Flows (unaudited) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Operating activities:	'	'
Net income	$169,555	$133,725
Adjustments to reconcile net income to net cash provided by operations:	'	'
Unrealized (gains) losses on open fuel hedge contracts	0	3,489
Equity-based compensation, net	6,315	3,970
Allowance for doubtful accounts	-63	128
Amortization of deferred gains and losses	-228	-452
Depreciation and amortization	33,803	22,403
Deferred income tax	-395	8,795
Loss on disposal of assets	1,658	426
Capitalized interest	-1,088	-140
Changes in operating assets and liabilities:	'	'
Accounts receivable	-3,206	-5,038
Prepaid maintenance reserves	-28,955	-10,166
Long-term deposits and other assets	-36,449	-37,062
Accounts payable	-5,524	-1,206
Air traffic liability	48,736	49,318
Other liabilities	22,136	5,441
Net cash provided by operating activities	206,295	173,631
Investing activities:	'	'
Pre-delivery deposits for flight equipment, net of refunds	-115,955	-41,328
Purchase of property and equipment	-26,261	-17,028
Net cash used in investing activities	-142,216	-58,356
Financing activities:	'	'
Proceeds from stock options exercised	140	675
Payments on capital lease obligations	-922	0
Proceeds from sale and leaseback transactions	0	6,900
Payments to pre-IPO shareholders pursuant to tax receivable agreement	-5,643	0
Excess tax benefits from equity-based compensation	1,690	1,635
Repurchase of common stock	-1,501	-1,106
Net cash (used in) provided by financing activities	-6,236	8,104
Net increase in cash and cash equivalents	57,843	123,379
Cash and cash equivalents at beginning of period	530,631	416,816
Cash and cash equivalents at end of period	588,474	540,195
Cash payments for:	'	'
Interest	398	26
Taxes	$88,884	$60,942

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accompanying unaudited condensed financial statements include the accounts of Spirit Airlines, Inc. (the Company). These unaudited condensed financial statements reflect all normal recurring adjustments which management believes are necessary to present fairly the financial position, results of operations and cash flows of the Company for the respective periods presented. Certain information and footnote disclosures normally included in the annual financial statements prepared in accordance with U.S. generally accepted accounting principles (GAAP) have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission for Form 10-Q. These unaudited interim condensed financial statements should be read in conjunction with the audited financial statements of the Company and notes thereto included in the Annual Report on Form 10-K for the year ended December 31, 2013 filed with the Securities and Exchange Commission.
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates.
	The interim results reflected in the unaudited condensed financial statements are not necessarily indicative of the results that may be expected for other interim periods or for the full year.

Recent_Accounting_Developments

Recent Accounting Developments	9 Months Ended
	Sep. 30, 2014
Accounting Changes and Error Corrections [Abstract]	'
Recent Accounting Developments	'
	Recent Accounting Developments
	In May 2014, the Financial Accounting Standards Board (the FASB) issued Accounting Standards Update (ASU) No. 2014-09, (ASU 2014-09), "Revenue from Contracts with Customers." The objective of ASU 2014-09 is to establish a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and will supersede most of the existing revenue recognition guidance, including industry-specific guidance. The core principle of ASU 2014-09 is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In applying the new guidance, an entity will (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the contract's performance obligations; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. ASU 2014-09 applies to all contracts with customers except those that are within the scope of other topics in the FASB Accounting Standards Codification. The new guidance is effective for annual reporting periods (including interim periods within those periods) beginning after December 15, 2016 for public companies. Early adoption is not permitted. Entities have the option of using either a full retrospective or modified approach to adopt ASU 2014-09. The Company is currently evaluating the new guidance and has not determined the impact this standard may have on its financial statements nor decided upon the planned method of adoption. While the Company is still evaluating the impact, it expects the accounting for its frequent flier program and certain ancillary fees to change.

Earnings_per_Share

Earnings per Share	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Earnings per Share	'
	Earnings per Share
	The following table sets forth the computation of basic and diluted earnings per common share:
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
		(in thousands, except per share amounts)
	Numerator
	Net income	$	67,000	$	61,103	$	169,555	$	133,725
	Denominator
	Weighted-average shares outstanding, basic	72,755		72,632		72,727		72,571
	Effect of dilutive stock awards	548		371		557		363
	Adjusted weighted-average shares outstanding, diluted	73,303		73,003		73,284		72,934
	Net Income per Share
	Basic earnings per common share	$	0.92	$	0.84	$	2.33	$	1.84
	Diluted earnings per common share	$	0.91	$	0.84	$	2.31	$	1.83
	Anti-dilutive weighted-average shares	—		1		38		1

Accrued_Liabilities

Accrued Liabilities	9 Months Ended
	Sep. 30, 2014
Payables and Accruals [Abstract]	'
Accrued Liabilities	'
	Accrued Liabilities
	Other current liabilities as of September 30, 2014 and December 31, 2013 consist of the following:
		September 30, 2014		December 31, 2013
		(in thousands)
	Federal excise and other passenger taxes and fees payable	$	42,790	$	26,979
	Salaries and wages	30,775		26,174
	Aircraft maintenance	29,738		36,165
	Airport expenses	18,155		17,109
	Fuel	11,799		13,819
	Aircraft and facility rent	9,153		7,993
	Federal and state income tax payable	5,031		794
	Other	12,945		16,229
	Other current liabilities	$	160,386	$	145,262

Financial_Instruments_and_Risk

Financial Instruments and Risk Management	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Financial Instruments and Risk Management	'
	Financial Instruments and Risk Management
	As part of the Company’s risk management program, the Company from time to time may use a variety of financial instruments to reduce its exposure to fluctuations in the price of jet fuel and interest rates. The Company does not hold or issue derivative financial instruments for trading purposes.
	The Company is exposed to credit losses in the event of nonperformance by counterparties to these financial instruments. The Company periodically reviews and seeks to mitigate exposure to the financial deterioration and nonperformance of any counterparty by monitoring the absolute exposure levels, each counterparty's credit ratings, and the historical performance of the counterparties relating to derivative transactions. The credit exposure related to these financial instruments is limited to the fair value of contracts in a net receivable position at the reporting date. The Company also maintains security agreements that require the Company to post collateral if the value of selected instruments falls below specified mark-to-market thresholds. As of September 30, 2014, the Company did not hold any derivatives with requirements to post collateral.
	The Company records financial derivative instruments at fair value, which includes an evaluation of each counterparty's credit risk. The Company's derivative contracts generally consist of United States Gulf Coast jet fuel swaps (jet fuel swaps) and United States Gulf Coast jet fuel options (jet fuel options). Both jet fuel swaps and jet fuel options are used at times to protect the refining price risk between the price of crude oil and the price of refined jet fuel, and to manage the risk of increasing fuel prices. Fair value of the instruments is determined using standard option valuation models.
	The Company did not elect hedge accounting on any fuel derivative instruments entered into during the three and nine months ended September 30, 2014 and 2013 and, as a result, changes in the fair value of these fuel derivative contracts are recorded in aircraft fuel expense. Premiums paid for fuel options are recognized in earnings within aircraft fuel expense as the fair value of the time value portion of each option changes.
	The following table summarizes the components of aircraft fuel expense for the three and nine months ended September 30, 2014 and 2013:
		Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014		2013
		(in thousands)
	Into-plane fuel cost	$	171,138	$	143,978		$	473,994	$	402,066
	Settlement losses (gains)	—		6,663			—		6,348
	Unrealized mark-to-market losses (gains)	—		(5,655		)	—		3,489
	Premium expense recognized related to fuel option contracts	446		—			913		—
	Aircraft fuel	$	171,584	$	144,986		$	474,907	$	411,903
	Premiums and settlements received or paid on fuel derivative contracts are reflected in the accompanying statements of cash flows in net cash provided by operating activities.
	During the third quarter of 2014, the Company became aware of an underpayment of Federal Excise Tax (FET) for fuel purchases during the period between July 1, 2009 and August 31, 2014. The commencement of the period in which the Company underpaid FET coincided with a change in its fuel service provider that took place in July 2009. The amount of underpayment of jet fuel FET from July 1, 2009 through December 31, 2013 is $9.3 million along with an additional $2.1 million for the nine months ended September 30, 2014. The total amount of $11.4 million is recorded within aircraft fuel in the statement of operations for the three and nine months ended September 30, 2014. Approximately, $0.8 million of interest was incurred related to the past-due tax payments. The Company does not believe the error to be material to the 2009 through 2013 financial statements nor for the cumulative out of period error to be material to the current year financial statements.
	Historically, during peak hurricane season (August through October), the Company has entered into jet fuel derivative contracts to protect the refining price risk between the price of crude oil and the price of refined jet fuel. As of September 30, 2014, the Company had fuel derivatives consisting of jet fuel options with refined products as the underlying commodities designed to protect 32.0 million gallons, or approximately 29.2% of the Company's fourth quarter 2014 and first quarter 2015 anticipated jet fuel consumption, at a weighted-average ceiling price of $3.19 per gallon. As of December 31, 2013, the Company had no outstanding fuel derivatives in place.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	Aircraft-Related Commitments and Financing Arrangements
	The Company’s contractual purchase commitments consist primarily of aircraft and engine acquisitions through manufacturers and aircraft leasing companies. As of September 30, 2014, the Company's aircraft orders consisted of the following:
		Airbus						Third-Party Lessor
		A320		A320NEO	A321		A321NEO	A320NEO		Total
	remainder of 2014	7								7
	2015	8			6			1		15
	2016	3			9			4		16
	2017	8			10					18
	2018	2		6	5					13
	2019			3			10			13
	2020			13						13
	2021			18						18
		28		40	30		10	5		113
	The Company also has six spare engine orders for V2500 SelectOne engines with International Aero Engines (IAE) and nine spare engine orders for PurePower PW1100G-JM engines with Pratt & Whitney. Spare engines are scheduled for delivery from 2014 through 2024. Purchase commitments for these aircraft and related flight equipment, including estimated amounts for contractual price escalations and pre-delivery payments, are estimated to be approximately $287 million for the remainder of 2014, $658 million in 2015, $601 million in 2016, $757 million in 2017, $615 million in 2018, and $2,208 million in 2019 and beyond. The Company has secured financing commitments with third parties for all seven aircraft deliveries, scheduled for delivery in 2014, and for six of the aircraft being delivered in 2015. The Company does not have financing commitments in place for the remaining 95 Airbus aircraft currently on firm order.
	During the first nine months of 2014, the Company took delivery of four aircraft which were financed via sale and leaseback transactions with third-party aircraft lessors. The four sale and leaseback transactions resulted in net deferred losses of $2.5 million. Deferred losses are included in other long-term assets on the accompanying balance sheet. Deferred losses are recognized as an increase to rent expense on a straight-line basis over the term of the respective operating leases. Deferred gains are included in deferred credits and other long-term liabilities on the accompanying balance sheet. Deferred gains are recognized as a decrease to rent expense on a straight-line basis over the term of the respective operating leases. The Company had agreements in place prior to the delivery of these aircraft which resulted in the settlement of the purchase obligation by the lessor and the refund of $20.4 million in pre-delivery deposits from Airbus during the nine months ended September 30, 2014. The refunded pre-delivery deposits have been disclosed in the accompanying statements of cash flows as pre-delivery deposits for flight equipment, net of refunds, within investing activities. All leases from these sale and leaseback transactions were accounted for as operating leases.
	Under the terms of the lease agreements, the Company will continue to operate and maintain the aircraft. Payments under the lease agreements are fixed for the term of the lease. The lease agreements contain standard termination events, including termination upon a breach of the Company's obligations to make rental payments and upon any other material breach of the Company's obligations under the leases, and standard maintenance and return condition provisions. These return provisions are evaluated at inception of the lease and throughout the lease terms and are accounted for as additional rent expense when it is probable that such amounts will be incurred. Upon a termination of the lease due to a breach by the Company, the Company would be liable for standard contractual damages, possibly including damages suffered by the lessor in connection with remarketing the aircraft or while the aircraft is not leased to another party.
	During the fourth quarter of 2013, the Company entered into an agreement for the lease of two quick engine change kits, classified as capital leases. Payments under the lease agreement are fixed for the three-year term of the lease.
	Future minimum lease payments under capital leases and noncancellable operating leases with initial or remaining terms in excess of one year at September 30, 2014 were as follows:
					Operating Leases
		Capital Leases			Aircraft and Spare Engine Leases			Property Facility Leases			Operating Lease Obligations
		(in thousands)
	remainder of 2014	$	511		$	50,185		$	7,449		$	57,634
	2015	1,244			201,304			22,212			223,516
	2016	1,044			199,479			13,320			212,799
	2017	44			182,977			9,549			192,526
	2018	44			159,290			7,286			166,576
	2019 and thereafter	12			634,537			24,541			659,078
	Total minimum lease payments	$	2,899		$	1,427,772		$	84,357		$	1,512,129
	Less amount representing interest	$	253
	Present value of minimum lease payments	$	2,646
	Less current portion	$	1,265
	Long term portion	$	1,381
	Aircraft rent expense consists of monthly lease rents for aircraft and spare engines under the terms of the related operating leases and is recognized on a straight-line basis. Aircraft rent expense also includes supplemental rent. Supplemental rent is made up of maintenance reserves paid or to be paid to aircraft lessors in advance of the performance of major maintenance activities that are not probable of being reimbursed, as well as lease return condition obligations which the Company begins to accrue when they are probable and can be estimated. The Company expects supplemental rent to increase as individual aircraft lease agreements approach their respective termination dates and the Company begins to accrue the estimated cost of return conditions for the corresponding aircraft.
	A majority of the Company’s master lease agreements provide that the Company pays maintenance reserves to aircraft lessors to be held as collateral in advance of the Company’s required performance of major maintenance activities. Maintenance reserve payments are either contractually fixed or utilization based amounts. Fixed maintenance reserve payments for these aircraft and related flight equipment, including estimated amounts for contractual price escalations, are expected to be approximately $1.8 million for the remainder of 2014, $7.6 million in 2015, $8.0 million in 2016, $7.4 million in 2017, $5.8 million in 2018, and $18.4 million in 2019 and beyond. These lease agreements provide that maintenance reserves are reimbursable to the Company upon completion of the maintenance event in an amount equal to the lesser of (1) the amount of the maintenance reserve held by the lessor associated with the specific maintenance event or (2) the qualifying costs related to the specific maintenance event.
	The Company is contractually obligated to pay the following minimum guaranteed payments for its reservation system and advertising media as of September 30, 2014: $0.9 million for the remainder of 2014, $3.9 million in 2015, $3.9 million in 2016, $3.9 million in 2017, $2.6 million in 2018, and none in 2019 and thereafter.
	Litigation
	The Company is subject to commercial litigation claims and to administrative and regulatory proceedings and reviews that may be asserted or maintained from time to time. The Company believes the ultimate outcome of such lawsuits, proceedings and reviews will not, individually or in the aggregate, have a material adverse effect on its financial position, liquidity or results of operations.
	Credit Card Processing Arrangements
	The Company has agreements with organizations that process credit card transactions arising from the purchase of air travel, baggage charges, and other ancillary services by customers. As it is standard in the airline industry, the Company's contractual arrangements with credit card processors permit them, under certain circumstances, to retain a holdback or other collateral, which the Company records as restricted cash, when future air travel and other future services are purchased via credit card transactions. The required holdback is the percentage of the Company's overall credit card sales its credit card processors hold to cover refunds to customers if the Company fails to fulfill its flight obligations. If the Company fails to satisfy certain liquidity and other financial covenants, the processing agreements provide the processors the right to require the Company to maintain cash collateral up to approximately 100% of the Company's air traffic liability, which would result in a commensurate reduction of unrestricted cash. As of September 30, 2014 and December 31, 2013, the Company continued to be in compliance with its credit card processing agreements and liquidity and other financial covenant requirements, and the processors were holding back no remittances.
	The maximum potential exposure to cash holdbacks by the Company's credit card processors, based upon advance ticket sales and $9 Fare Club memberships as of September 30, 2014 and December 31, 2013, was $250.6 million and $188.6 million, respectively.
	Employees
	Approximately 60% of the Company’s employees are covered under collective bargaining agreements. The table below sets forth the Company's employee groups and status of the collective bargaining agreements as of September 30, 2014.
	Employee Groups	Representative		Amendable Date	Percentage of Workforce
	Pilots	Air Line Pilots Association, International (ALPA)		August 2015	25%
	Flight Attendants	Association of Flight Attendants (AFA-CWA)		Aug-07	34%
	Dispatchers	Transport Workers Union (TWU)		Aug-18	1%
	In August 2014, under the supervision of the National Mediation Board (NMB), the Company and AFA-CWA reached a tentative agreement for a five-year contract with the Company's flight attendants. The tentative agreement was subject to ratification by the flight attendant membership. On October 1, 2014, the Company was notified that the flight attendants voted not to ratify the tentative agreement. The Company will continue to work together with the AFA-CWA and the NMB with a goal of reaching a mutually beneficial agreement. On July 8, 2014, approximately 250 ramp service agents directly employed by the Company voted to be represented by the International Association of Machinists and Aerospace Workers (IAM). These ramp service agents currently serve 4 of the 56 airports where the Company operates. The Company is in discussions with the IAM to begin the process of negotiating a collective bargaining agreement.
	The Company is self-insured for health care claims, up to a stop loss amount for eligible participating employees, and qualified dependent medical claims, subject to deductibles and limitations. The Company’s liabilities for claims incurred but not reported are determined based on an estimate of the ultimate aggregate liability for claims incurred. The estimate is calculated from actual claim rates and adjusted periodically as necessary. The Company has accrued $2.5 million and $2.1 million in health care claims as of September 30, 2014 and December 31, 2013, respectively.
	Other
	On October 15, 2013, a Company aircraft experienced an engine failure shortly after takeoff. The aircraft immediately returned to the airport, and the passengers and crew safely disembarked from the aircraft. The airframe and engine incurred damage as a result of the failure. In 2013, the Company expensed the insurance deductible related to this incident of approximately $0.8 million. As of September 30, 2014, the Company has received insurance proceeds for a portion of the damage incurred. After the conclusion of a lengthy investigation into the incident, the Company now anticipates it will receive a new replacement engine from the manufacturer, in exchange for a $2.3 million payment to the manufacturer. Upon receipt, title to the engine will transfer to the lessor. The Company expensed $2.3 million within maintenance, materials and repairs in the statement of operations for the three and nine months ended September 30, 2014.
	On July 22, 2014, the Company purchased $13.1 million of rotable spare inventory which was previously rented. The cost to rent this inventory was recorded as maintenance, material and repairs within the statement of operations. As a result of the purchase, the inventory will be capitalized and the cost will be amortized over the remaining useful life of the assets. The amortization will be recorded as depreciation and amortization within the statement of operations.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	Under ASC 820, Fair Value Measurements and Disclosures, disclosures are required about how fair value is determined for assets and liabilities, and a hierarchy for which these assets and liabilities must be grouped is established, based on significant levels of inputs, as follows:
	Level 1—Quoted prices in active markets for identical assets or liabilities.
	Level 2—Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company utilizes several valuation techniques in order to assess the fair value of the Company’s financial assets and liabilities. The Company's derivative contracts generally consist of jet fuel swaps and jet fuel options. These instruments are valued using energy and commodity market data, which is derived by combining raw inputs with quantitative models and processes to generate forward curves and volatilities.
	The Company utilizes the market approach to measure fair value for its financial assets and liabilities. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities.
	Assets and liabilities measured at gross fair value on a recurring basis are summarized below:
		Fair Value Measurements as of September 30, 2014
		Total			Level		Level		Level
					1		2		3
		(in millions)
	Cash and cash equivalents	$	588.5		$	588.5	$	—	$	—
	Jet fuel options	0.1			—		—		0.1
	Total assets	$	588.6		$	588.5	$	—	$	0.1
	Total liabilities	$	—		$	—	$	—	$	—
		Fair Value Measurements as of December 31, 2013
		Total			Level		Level		Level
					1		2		3
		(in millions)
	Cash and cash equivalents	$	530.6		$	530.6	$	—	$	—
	Total assets	$	530.6		$	530.6	$	—	$	—
	Total liabilities	$	—		$	—	$	—	$	—
	Cash and cash equivalents at September 30, 2014 and December 31, 2013 are comprised of liquid money market funds and cash and are categorized as Level 1 instruments. The Company maintains cash with various high-quality financial institutions. The Company had no transfers of assets or liabilities between any of the above levels during the nine months ended September 30, 2014 and the year ended December 31, 2013.
	The Company did not elect hedge accounting on any of its fuel derivative instruments, and as a result, changes in the fair values of these fuel derivative contracts are recorded each period in fuel expense. Fair value of the instruments is determined using standard option valuation models. The Company also considers counterparty risk and its own credit risk in its determination of all estimated fair values. Within the Condensed Balance Sheets, the Company offsets fair value amounts recognized for derivative instruments executed with the same counterparty under a master netting arrangement. All derivative instruments are presented on a gross basis in the table above.
	The Company determines the fair value of jet fuel options utilizing an option pricing model based on inputs that are either readily available in public markets or can be derived from information available in publicly quoted markets. The Company has consistently applied these valuation techniques in all periods presented and believes it has obtained the most accurate information available for the types of derivative contracts it holds.
	The fair value of the Company's jet fuel swaps are determined based on inputs that are readily available in public markets or can be derived from information available in publicly quoted markets; therefore, the Company has categorized these instruments as Level 2. Certain inputs utilized to determine the fair value of the Company's jet fuel options are unobservable (principally implied volatility); therefore, the Company has categorized these instruments as Level 3.
	The Company records the fair value of its aircraft fuel derivatives on the balance sheet within other current assets or other current liabilities, depending on whether the net fair value of the derivatives is in an asset or liability position as of the respective date. Changes in the fair value of aircraft fuel derivatives are reflected in the accompanying statement of operations within aircraft fuel.
	The Company's Valuation Group is made up of individuals from the Company's Risk Management, Treasury and Corporate Accounting departments. The Valuation Group is responsible for the Company's valuation policies, procedures and execution thereof. The Company's Valuation Group reports to the Company's Chief Financial Officer and seeks approval for certain fuel derivative transactions from the Audit Committee. The Valuation Group compares the results of the Company's internally developed valuation methods with counterparty reports at each balance sheet date and assesses the Company's valuation methods for accurateness and identifies any needs for modification.
	The following table presents the Company's activity for assets and liabilities measured at gross fair value on a recurring basis using significant unobservable inputs (Level 3):
		Jet Fuel Option Activity for the Three Months Ended September 30, 2014
		(in thousands)
	Balance at June 30, 2014	360
	Total realized or unrealized gains (losses) included in earnings, net	(446		)
	Purchases	164
	Sales	—
	Settlements, net	—
	Balance at September 30, 2014	$	78
		Jet Fuel Option Activity for the Nine Months Ended September 30, 2014
		(in thousands)
	Balance at December 31, 2013	—
	Total realized or unrealized gains (losses) included in earnings, net	(913		)
	Purchases	991
	Sales	—
	Settlements, net	—
	Balance at September 30, 2014	$	78

Tax_Receivable_Agreement

Tax Receivable Agreement	9 Months Ended
	Sep. 30, 2014
Tax Receivable Agreement [Abstract]	'
Tax Receivable Agreement	'
	Tax Receivable Agreement
	On June 1, 2011, the Company completed its initial public offering of common stock, or IPO. In connection with the IPO, the Company entered into a Tax Receivable Agreement (TRA) and thereby distributed immediately prior to the completion of the IPO to the holders of common stock as of such time, or the Pre-IPO Stockholders, the right to receive an amount equal to 90% of the cash savings in federal income tax realized by the Company by virtue of the use of the federal net operating loss, deferred interest deductions, and alternative minimum tax credits held by the Company as of March 31, 2011, which is defined as the Pre-IPO NOL. Cash tax savings generally will be computed by comparing the actual federal income tax liability to the amount of such taxes that the Company would have been required to pay had such Pre-IPO NOLs not been available. Upon consummation of the IPO and execution of the TRA, the Company recorded a liability with an offsetting reduction to additional paid-in-capital. The amount and timing of payments under the TRA depends upon a number of factors, including, but not limited to, the amount and timing of taxable income generated in the future and any future limitations that may be imposed on the Company's ability to use the Pre-IPO NOLs. The term of the TRA continues until the first to occur of (a) the full payment of all amounts required under the agreement with respect to utilization or expiration of all the Pre-IPO NOLs, (b) the end of the taxable year including the tenth anniversary of the IPO or (c) a change in control of the Company.
	In accordance with the TRA, the Company is required to submit a Tax Benefit Schedule showing the proposed TRA payout amount to the Stockholder Representatives within 45 calendar days after the Company files its tax return. The Stockholder Representatives are Indigo Pacific Partners, LLC and OCM FIE, LLC, who represent the two largest ownership interests of pre-IPO shares. The Tax Benefit Schedule shall become final and binding on all parties unless a Stockholder Representative, within 45 calendar days after receiving such schedule, provides the Company with notice of a material objection to such schedule. If the parties, for any reason, are unable to successfully resolve the issues raised in any notice within 30 calendar days of receipt of such notice, the Company and the Stockholder Representatives shall employ the Reconciliation procedures. If the Tax Benefit Schedule is accepted, the Company has five days after the acceptance to make payments to the pre-IPO shareholders. Pursuant to the TRA's Reconciliation procedures, any disputes that cannot be settled amicably, are settled by arbitration conducted by a single arbitrator jointly selected by both parties.
	During the second quarter of 2012, the Company paid $27.2 million, or 90% of the 2011 tax savings realized from the utilization of NOLs, including $0.3 million of applicable interest, to the Pre-IPO Stockholders.
	During 2013, the Company filed an amended 2009 income tax return which resulted in a reduction to the estimated TRA liability from $8.0 million to $5.6 million. On September 13, 2013, the Company filed its 2012 federal income tax return, and on October 14, 2013 the Company submitted the Tax Benefit Schedule to the Stockholder Representatives. On November 27, 2013, pursuant to the TRA, the Company received an objection notice to the Tax Benefit Schedule from the Stockholder Representatives. After several unsuccessful attempts at resolving the objections, on April 7, 2014, the Company received a demand for arbitration from the Stockholder Representatives. Prior to commencing arbitration proceedings, on June 17, 2014, the Company and Stockholder Representatives agreed on a settlement amount of $7.0 million in addition to interest of $0.3 million. The agreed upon settlement was in excess of the outstanding liability of $5.6 million at the time of settlement. The excess payment of $1.4 million was recorded within other expense in the statement of operations and recorded as cash from operations in the statement of cash flows. As of September 30, 2014, the Company had made all payments in accordance with the agreed upon settlement terms and had no outstanding obligations related to the TRA.

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	9	Subsequent Events
	The Company has entered into a Framework Agreement, dated as of October 1, 2014 (Framework Agreement), with a bank syndicate which will provide up to $379 million of debt financing for seven Airbus A320 aircraft and three Airbus A321 aircraft scheduled for delivery under the Company's existing purchase agreement with Airbus between October 2014 and September 2015. Each loan to be extended under the Framework Agreement will be funded on or about the delivery date of each aircraft and will be secured by a first-priority security interest in the individual aircraft. Each loan will amortize quarterly on a mortgage-style basis, with senior loans having a 12-year term and junior loans having a 7-year term. Loans will bear interest payable quarterly on a floating rate basis, provided that the Company may elect in advance a fixed rate basis. On October 16, 2014, the Company took delivery of an A320 aircraft financed through the Framework Agreement and recorded debt of $37.0 million in relation to this transaction.
	On October 23, 2014, the Company entered into forward interest rate swaps that fix the benchmark interest rate component of the forecasted interest payments on the debt related to three Airbus 321 aircraft with expected delivery dates ranging from July 2015 to September 2015 to limit the Company’s exposure to changes in the benchmark interest rate in the period from the trade date through the date of actual delivery. The interest rate swaps will be designated as cash flow hedges.

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of accounting	'
	The accompanying unaudited condensed financial statements include the accounts of Spirit Airlines, Inc. (the Company). These unaudited condensed financial statements reflect all normal recurring adjustments which management believes are necessary to present fairly the financial position, results of operations and cash flows of the Company for the respective periods presented. Certain information and footnote disclosures normally included in the annual financial statements prepared in accordance with U.S. generally accepted accounting principles (GAAP) have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission for Form 10-Q. These unaudited interim condensed financial statements should be read in conjunction with the audited financial statements of the Company and notes thereto included in the Annual Report on Form 10-K for the year ended December 31, 2013 filed with the Securities and Exchange Commission.
Use of estimates	'
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates.
Recent Accounting Developments	'
	In May 2014, the Financial Accounting Standards Board (the FASB) issued Accounting Standards Update (ASU) No. 2014-09, (ASU 2014-09), "Revenue from Contracts with Customers." The objective of ASU 2014-09 is to establish a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and will supersede most of the existing revenue recognition guidance, including industry-specific guidance. The core principle of ASU 2014-09 is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In applying the new guidance, an entity will (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the contract's performance obligations; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. ASU 2014-09 applies to all contracts with customers except those that are within the scope of other topics in the FASB Accounting Standards Codification. The new guidance is effective for annual reporting periods (including interim periods within those periods) beginning after December 15, 2016 for public companies. Early adoption is not permitted. Entities have the option of using either a full retrospective or modified approach to adopt ASU 2014-09. The Company is currently evaluating the new guidance and has not determined the impact this standard may have on its financial statements nor decided upon the planned method of adoption. While the Company is still evaluating the impact, it expects the accounting for its frequent flier program and certain ancillary fees to change.

Earnings_per_Share_Tables

Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Computation of basic and diluted earnings per common share	'
	The following table sets forth the computation of basic and diluted earnings per common share:
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
		(in thousands, except per share amounts)
	Numerator
	Net income	$	67,000	$	61,103	$	169,555	$	133,725
	Denominator
	Weighted-average shares outstanding, basic	72,755		72,632		72,727		72,571
	Effect of dilutive stock awards	548		371		557		363
	Adjusted weighted-average shares outstanding, diluted	73,303		73,003		73,284		72,934
	Net Income per Share
	Basic earnings per common share	$	0.92	$	0.84	$	2.33	$	1.84
	Diluted earnings per common share	$	0.91	$	0.84	$	2.31	$	1.83
	Anti-dilutive weighted-average shares	—		1		38		1

Accrued_Liabilities_Tables

Accrued Liabilities (Tables)	9 Months Ended
	Sep. 30, 2014
Payables and Accruals [Abstract]	'
Accrued liabilities included in other current liabilities	'
	Other current liabilities as of September 30, 2014 and December 31, 2013 consist of the following:
		September 30, 2014		December 31, 2013
		(in thousands)
	Federal excise and other passenger taxes and fees payable	$	42,790	$	26,979
	Salaries and wages	30,775		26,174
	Aircraft maintenance	29,738		36,165
	Airport expenses	18,155		17,109
	Fuel	11,799		13,819
	Aircraft and facility rent	9,153		7,993
	Federal and state income tax payable	5,031		794
	Other	12,945		16,229
	Other current liabilities	$	160,386	$	145,262

Financial_Instruments_and_Risk1

Financial Instruments and Risk Management (Tables)	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Components of aircraft fuel expense	'
	The following table summarizes the components of aircraft fuel expense for the three and nine months ended September 30, 2014 and 2013:
		Three Months Ended September 30,					Nine Months Ended September 30,
		2014		2013			2014		2013
		(in thousands)
	Into-plane fuel cost	$	171,138	$	143,978		$	473,994	$	402,066
	Settlement losses (gains)	—		6,663			—		6,348
	Unrealized mark-to-market losses (gains)	—		(5,655		)	—		3,489
	Premium expense recognized related to fuel option contracts	446		—			913		—
	Aircraft fuel	$	171,584	$	144,986		$	474,907	$	411,903

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Schedule of Future Operating Aircraft Leases	'
	As of September 30, 2014, the Company's aircraft orders consisted of the following:
		Airbus						Third-Party Lessor
		A320		A320NEO	A321		A321NEO	A320NEO		Total
	remainder of 2014	7								7
	2015	8			6			1		15
	2016	3			9			4		16
	2017	8			10					18
	2018	2		6	5					13
	2019			3			10			13
	2020			13						13
	2021			18						18
		28		40	30		10	5		113
Future minimum lease payments under noncancelable capital leases	'
	Future minimum lease payments under capital leases and noncancellable operating leases with initial or remaining terms in excess of one year at September 30, 2014 were as follows:
					Operating Leases
		Capital Leases			Aircraft and Spare Engine Leases			Property Facility Leases			Operating Lease Obligations
		(in thousands)
	remainder of 2014	$	511		$	50,185		$	7,449		$	57,634
	2015	1,244			201,304			22,212			223,516
	2016	1,044			199,479			13,320			212,799
	2017	44			182,977			9,549			192,526
	2018	44			159,290			7,286			166,576
	2019 and thereafter	12			634,537			24,541			659,078
	Total minimum lease payments	$	2,899		$	1,427,772		$	84,357		$	1,512,129
	Less amount representing interest	$	253
	Present value of minimum lease payments	$	2,646
	Less current portion	$	1,265
	Long term portion	$	1,381
Future minimum lease payments under noncancelable operating leases	'
	Future minimum lease payments under capital leases and noncancellable operating leases with initial or remaining terms in excess of one year at September 30, 2014 were as follows:
					Operating Leases
		Capital Leases			Aircraft and Spare Engine Leases			Property Facility Leases			Operating Lease Obligations
		(in thousands)
	remainder of 2014	$	511		$	50,185		$	7,449		$	57,634
	2015	1,244			201,304			22,212			223,516
	2016	1,044			199,479			13,320			212,799
	2017	44			182,977			9,549			192,526
	2018	44			159,290			7,286			166,576
	2019 and thereafter	12			634,537			24,541			659,078
	Total minimum lease payments	$	2,899		$	1,427,772		$	84,357		$	1,512,129
	Less amount representing interest	$	253
	Present value of minimum lease payments	$	2,646
	Less current portion	$	1,265
	Long term portion	$	1,381
Employee groups and status of the collective bargaining agreements	'
	The table below sets forth the Company's employee groups and status of the collective bargaining agreements as of September 30, 2014.
	Employee Groups	Representative		Amendable Date	Percentage of Workforce
	Pilots	Air Line Pilots Association, International (ALPA)		August 2015	25%
	Flight Attendants	Association of Flight Attendants (AFA-CWA)		Aug-07	34%
	Dispatchers	Transport Workers Union (TWU)		Aug-18	1%

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Schedule of assets and liabilities measured at fair value on a recurring basis	'
	Assets and liabilities measured at gross fair value on a recurring basis are summarized below:
		Fair Value Measurements as of September 30, 2014
		Total			Level		Level		Level
					1		2		3
		(in millions)
	Cash and cash equivalents	$	588.5		$	588.5	$	—	$	—
	Jet fuel options	0.1			—		—		0.1
	Total assets	$	588.6		$	588.5	$	—	$	0.1
	Total liabilities	$	—		$	—	$	—	$	—
		Fair Value Measurements as of December 31, 2013
		Total			Level		Level		Level
					1		2		3
		(in millions)
	Cash and cash equivalents	$	530.6		$	530.6	$	—	$	—
	Total assets	$	530.6		$	530.6	$	—	$	—
	Total liabilities	$	—		$	—	$	—	$	—
Schedule of assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)	'
	The following table presents the Company's activity for assets and liabilities measured at gross fair value on a recurring basis using significant unobservable inputs (Level 3):
		Jet Fuel Option Activity for the Three Months Ended September 30, 2014
		(in thousands)
	Balance at June 30, 2014	360
	Total realized or unrealized gains (losses) included in earnings, net	(446		)
	Purchases	164
	Sales	—
	Settlements, net	—
	Balance at September 30, 2014	$	78
		Jet Fuel Option Activity for the Nine Months Ended September 30, 2014
		(in thousands)
	Balance at December 31, 2013	—
	Total realized or unrealized gains (losses) included in earnings, net	(913		)
	Purchases	991
	Sales	—
	Settlements, net	—
	Balance at September 30, 2014	$	78

Earnings_per_Share_Details

Earnings per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Numerator	'	'	'	'
Net income	$67,000	$61,103	$169,555	$133,725
Denominator	'	'	'	'
Weighted-average shares outstanding, basic	72,755	72,632	72,727	72,571
Effect of dilutive stock awards (in shares)	548	371	557	363
Adjusted weighted-average shares outstanding, diluted	73,303	73,003	73,284	72,934
Net Income per Share	'	'	'	'
Basic earnings per common share (in dollars per share)	$0.92	$0.84	$2.33	$1.84
Diluted earnings per common share (in dollars per share)	$0.91	$0.84	$2.31	$1.83
Anti-dilutive weighted-average shares	0	1	38	1

Accrued_Liabilities_Details

Accrued Liabilities (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]	'	'
Federal excise and other passenger taxes and fees payable	$42,790	$26,979
Salaries and wages	30,775	26,174
Aircraft maintenance	29,738	36,165
Airport expenses	18,155	17,109
Fuel	11,799	13,819
Federal and state income tax payable	9,153	7,993
Aircraft and facility rent	5,031	794
Other	12,945	16,229
Other current liabilities	$160,386	$145,262

Financial_Instruments_and_Risk2

Financial Instruments and Risk Management (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'	'	'	'
Into-plane fuel cost	$171,138	$143,978	$473,994	$402,066
Settlement losses (gains)	0	6,663	0	6,348
Unrealized mark-to-market losses (gains)	0	-5,655	0	3,489
Premium expense recognized related to fuel option contracts	446	0	913	0
Aircraft fuel	$171,584	$144,986	$474,907	$411,903

Financial_Instruments_and_Risk3

Financial Instruments and Risk Management - Narrative (Details) (USD $)	8 Months Ended	54 Months Ended	62 Months Ended
In Millions, unless otherwise specified	Aug. 31, 2014	Dec. 31, 2013	Aug. 31, 2014	Sep. 30, 2014
				gal
Derivative [Line Items]	'	'	'	'
Federal excise tax	$2.10	$9.30	$11.40	'
Interest expense, past-due fuel excise tax	'	'	$0.80	'
Anticipated jet fuel consumption protected by hedges (in gallons)	'	'	'	32,000,000
Anticipated jet fuel consumption protected by hedges (as a percent)	'	'	'	29.20%
Fuel [Member] | Options Held [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Derivative contract, weighted average ceiling price (in USD per gallon)	'	'	'	3.19
Fuel [Member] | Future [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Number of derivative contracts	'	0	'	'

Commitments_and_Contingencies_1

Commitments and Contingencies - Aircraft Contractual Purchase Commitments (Details)	Sep. 30, 2014
	aircraft
Long-term Purchase Commitment [Line Items]	'
Future Aircraft To Be Received, Remainder of FIscal Year	7
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	113
Airbus [Member] | Airbus 320 [Member]	'
Long-term Purchase Commitment [Line Items]	'
Future Aircraft To Be Received, Remainder of FIscal Year	7
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	28
Airbus [Member] | Airbus A320 NEO [Member]	'
Long-term Purchase Commitment [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 A321 [Member]	'
Long-term Purchase Commitment [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]	'
Long-term Purchase Commitment [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]	'
Long-term Purchase Commitment [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

Commitments_and_Contingencies_2

Commitments and Contingencies - Commitments (Details) (USD $)	Sep. 30, 2014
	aircraft
Airbus [Member]	'
Unrecorded Unconditional Purchase Obligation [Line Items]	'
Number of Aircraft without Secured Financing Commitments Scheduled for Delivery (in aircraft)	95
Airbus [Member] | 2014 [Member]	'
Unrecorded Unconditional Purchase Obligation [Line Items]	'
Number of Aircraft with Secured Financing Commitments Scheduled for Delivery (in aircraft)	7
Airbus [Member] | 2015 [Member]	'
Unrecorded Unconditional Purchase Obligation [Line Items]	'
Number of Aircraft without Secured Financing Commitments Scheduled for Delivery (in aircraft)	6
Aircraft and Related Flight Equipment [Member]	'
Unrecorded Unconditional Purchase Obligation [Line Items]	'
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	287,000,000
Unrecorded Unconditional Purchase Obligation, Due in 2015	658,000,000
Unrecorded Unconditional Purchase Obligation, Due in 2016	601,000,000
Unrecorded Unconditional Purchase Obligation, Due in 2017	757,000,000
Unrecorded Unconditional Purchase Obligation, Due in 2018	615,000,000
Unrecorded Unconditional Purchase Obligation, Due in 2019 and beyond	2,208,000,000
V2500 SelectOne Engine [Member]	'
Unrecorded Unconditional Purchase Obligation [Line Items]	'
Number of spare aircraft engines ordered (in aircraft engine)	6
PurePower PW1100G-JM Engine [Member]	'
Unrecorded Unconditional Purchase Obligation [Line Items]	'
Number of spare aircraft engines ordered (in aircraft engine)	9

Commitments_and_Contingencies_3

Commitments and Contingencies - Sale Leaseback Transactions Aircraft (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
	aircraft
Commitments and Contingencies Disclosure [Abstract]	'
Number of aircrafts delivered	4
Aircraft [Member]	'
Sale Leaseback Transaction [Line Items]	'
Number of aircraft entered into sale and leaseback agreement	4
Sale leaseback transaction on aircraft, net deferred gain (loss)	-2.5
Sale leaseback transaction on aircraft, refund in pre-delivery deposits	20.4

Commitments_and_Contingencies_4

Commitments and Contingencies - Future Minimum Lease Payments Under Noncancelable Operating Leases (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
		leases
Capital Leases, Future Minimum Payments, Net Minimum Payments, Rolling Maturity [Abstract]	'	'
Future Minimum Payments Due, Remainder of Fiscal Year	511	'
Future Minimum Payments Due, 2015	1,244	'
Future Minimum Payments Due, 2016	1,044	'
Future Minimum Payments Due, 2017	44	'
Future Minimum Payments Due, 2018	44	'
Future Minimum Payments Due, 2019 and thereafter	12	'
Total minimum lease payments	2,899	'
Less amount representing interest	253	'
Present value of minimum lease payments	2,646	'
Less current portion	1,265	'
Long term portion	1,381	'
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]	'	'
Future Minimum Payments Due, Remainder of Fiscal Year	57,634	'
Future Minimum Payments Due, 2015	223,516	'
Future Minimum Payments Due, 2016	212,799	'
Future Minimum Payments Due, 2017	192,526	'
Future Minimum Payments Due, 2018	166,576	'
Future Minimum Payments Due, 2019 and thereafter	659,078	'
Total minimum lease payments	1,512,129	'
Aircraft and Spare Engine Leases [Member]	'	'
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]	'	'
Future Minimum Payments Due, Remainder of Fiscal Year	50,185	'
Future Minimum Payments Due, 2015	201,304	'
Future Minimum Payments Due, 2016	199,479	'
Future Minimum Payments Due, 2017	182,977	'
Future Minimum Payments Due, 2018	159,290	'
Future Minimum Payments Due, 2019 and thereafter	634,537	'
Total minimum lease payments	1,427,772	'
Property Facility Leases [Member]	'	'
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]	'	'
Future Minimum Payments Due, Remainder of Fiscal Year	7,449	'
Future Minimum Payments Due, 2015	22,212	'
Future Minimum Payments Due, 2016	13,320	'
Future Minimum Payments Due, 2017	9,549	'
Future Minimum Payments Due, 2018	7,286	'
Future Minimum Payments Due, 2019 and thereafter	24,541	'
Total minimum lease payments	84,357	'
Quick Engine Change Kit [Member]	'	'
Capital Leased Assets [Line Items]	'	'
Number of Capital Leases	'	2
Capital Leases of Lessee, Lease Term	'3 years	'

Commitments_and_Contingencies_5

Commitments and Contingencies - Fixed Maintenance Reserve Payments and Other Commitments (Details) (USD $)	Sep. 30, 2014
Reservation System and Advertising Media [Member]	'
Unrecorded Unconditional Purchase Obligation [Line Items]	'
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	$900,000
Unrecorded Unconditional Purchase Obligation, Due in 2015	3,900,000
Unrecorded Unconditional Purchase Obligation, Due in 2016	3,900,000
Unrecorded Unconditional Purchase Obligation, Due in 2017	3,900,000
Unrecorded Unconditional Purchase Obligation, Due in 2018	2,600,000
Unrecorded Unconditional Purchase Obligation, Due in 2019 and beyond	0
Aircraft and Related Flight Equipment [Member] | Fixed Maintenance Reserve Payments [Member]	'
Unrecorded Unconditional Purchase Obligation [Line Items]	'
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	1,800,000
Unrecorded Unconditional Purchase Obligation, Due in 2015	7,600,000
Unrecorded Unconditional Purchase Obligation, Due in 2016	8,000,000
Unrecorded Unconditional Purchase Obligation, Due in 2017	7,400,000
Unrecorded Unconditional Purchase Obligation, Due in 2018	5,800,000
Unrecorded Unconditional Purchase Obligation, Due in 2019 and beyond	$18,400,000

Commitments_and_Contingencies_6

Commitments and Contingencies - Insurance Deductible (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Insurance Deductible	$0.80

Commitments_and_Contingencies_7

Commitments and Contingencies - Credit Card Processing Arrangements (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'	'
Cash collateral required for credit card transactions as a percentage of air traffic liability, prior to amendment	100.00%	'
Restricted Cash and Cash Equivalents Items [Line Items]	'	'
Restricted cash holdbacks	$0	$0
Maximum [Member]	'	'
Restricted Cash and Cash Equivalents Items [Line Items]	'	'
Restricted cash holdbacks	$250,600,000	$188,600,000

Commitments_and_Contingencies_8

Commitments and Contingencies - Employees (Details) (USD $)	Jul. 08, 2014	Sep. 30, 2014	Dec. 31, 2013	Jul. 08, 2014	Sep. 30, 2014	Jul. 08, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014
In Millions, unless otherwise specified	airport	Health Insurance [Member]	Health Insurance [Member]	Ramp Service Agents [Member]	Association of Flight Attendants [Member]	International Association Of Machinists And Aerospace Workers (IAM) [Member]	Unionized Employees Concentration Risk [Member]	Unionized Employees Concentration Risk [Member]	Unionized Employees Concentration Risk [Member]	Unionized Employees Concentration Risk [Member]
				employee		airport	Number of Employees, Total [Member]	Number of Employees, Total [Member]	Number of Employees, Total [Member]	Number of Employees, Total [Member]
								Air Line Pilots Association, International [Member]	Association of Flight Attendants [Member]	Transport Workers Union [Member]
Concentration Risk [Line Items]	'	'	'	'	'	'	'	'	'	'
Company's employees covered under collective bargaining agreements (as a percent)	'	'	'	'	'	'	60.00%	25.00%	34.00%	1.00%
Tentative collective bargaining agreement, contract term	'	'	'	'	'5 years	'	'	'	'	'
Number of employees	'	'	'	250	'	'	'	'	'	'
Number of airports in which entity operates	56	'	'	'	'	4	'	'	'	'
Liability for Claims and Claims Adjustment Expense [Line Items]	'	'	'	'	'	'	'	'	'	'
Accrued health care claims	'	$2.50	$2.10	'	'	'	'	'	'	'

Commitments_and_Contingencies_9

Commitments and Contingencies Commitments and Contingencies - Payment due to Manufacturer (Details) (USD $)	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2014
Commitments and Contingencies [Abstract]	'	'
Engine, Replacement Expense	$2.30	$2.30

Recovered_Sheet1

Commitments and Contingencies Commitments and Contingencies - Rotable Spare Inventory Purchase (Details) (USD $)	Jul. 22, 2014
In Millions, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'
Other rotable inventory	$13.10

Fair_Value_Measurements_Assets

Fair Value Measurements - Assets and Liabilities Measured on Recurring Basis (Details) (Fair Value, Measurements, Recurring [Member], USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and cash equivalents	$588.50	$530.60
Total assets	588.6	530.6
Total liabilities	0	0
Jet fuel options [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative assets	0.1	'
Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and cash equivalents	588.5	530.6
Total assets	588.5	530.6
Total liabilities	0	0
Level 1 [Member] | Jet fuel options [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative assets	0	'
Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and cash equivalents	0	0
Total assets	0	0
Total liabilities	0	0
Level 2 [Member] | Jet fuel options [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative assets	0	'
Level 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and cash equivalents	0	0
Total assets	0.1	0
Total liabilities	0	0
Level 3 [Member] | Jet fuel options [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative assets	$0.10	'

Fair_Value_Measurements_Unobse

Fair Value Measurements - Unobservable Inputs (Details) (Jet fuel options [Member], USD $)	3 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2014
Jet fuel options [Member]	'	'
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]	'	'
Beginning Balance	$360	$0
Total realized or unrealized gains (losses) included in earnings, net	-446	-913
Purchases	164	991
Sales	0	0
Settlements, net	0	0
Ending Balance	$78	$78

Tax_Receivable_Agreement_Detai

Tax Receivable Agreement (Details) (USD $)	0 Months Ended		3 Months Ended	9 Months Ended
	Jun. 17, 2014	Jun. 01, 2011	Jun. 30, 2012	Sep. 30, 2014	Sep. 30, 2013	Jun. 17, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 01, 2011	Mar. 31, 2011
									owner
Tax Receivable Agreement [Abstract]	'	'	'	'	'	'	'	'	'	'
Percentage of cash savings from pre-initial public offering net operating loss due to pre-initial public offering stockholders	'	'	90.00%	'	'	'	'	'	'	90.00%
Tax receivable agreement, tax benefit schedule days to submission	'	'45 days	'	'	'	'	'	'	'	'
Tax receivable agreement, number of largest owners pre initial public offering	'	'	'	'	'	'	'	'	2	'
Tax receivable agreement, tax benefit schedule days to response	'	'45 days	'	'	'	'	'	'	'	'
Tax receivable agreement, tax benefit schedule days to resolve notice	'	'30 days	'	'	'	'	'	'	'	'
Tax receivable agreement, tax benefit schedule days to payment after acceptance	'	'5 days	'	'	'	'	'	'	'	'
Cash payment including interest to pre-IPO stockholders pursuant to tax receivable agreement	'	'	$27,200,000	$5,643,000	$0	'	'	'	'	'
Interest included in cash payment to pre-IPO stockholders pursuant to tax receivable agreement	'	'	300,000	'	'	'	'	'	'	'
Estimated remaining cash payment to pre-IPO stockholders	'	'	'	'	'	5,600,000	5,600,000	8,000,000	'	'
Tax settlement amount	7,000,000	'	'	'	'	'	'	'	'	'
Tax settlement interest	300,000	'	'	'	'	'	'	'	'	'
Excess Tax Payment Resulting From Settlement	'	'	'	$1,400,000	'	'	'	'	'	'

Subsequent_Events_Details

Subsequent Events (Details) (Subsequent Event [Member], USD $)	Oct. 01, 2014	Oct. 01, 2014	Oct. 01, 2014	Oct. 16, 2014	Oct. 01, 2014	Oct. 23, 2014	Oct. 01, 2014
In Millions, unless otherwise specified		Senior Loans [Member]	Junior Loans [Member]	Airbus 320 [Member]	Airbus 320 [Member]	Airbus A321 [Member]	Airbus A321 [Member]
					aircraft	aircraft	aircraft
Subsequent Event [Line Items]	'	'	'	'	'	'	'
Debt instrument, maximum borrowing capacity	$379	'	'	'	'	'	'
Number of Aircraft with Secured Financing Commitments Scheduled for Delivery (in aircraft)	'	'	'	'	7	'	3
Number of aircraft to be received, next twelve months (in aircraft)	'	'	'	'	'	3	'
Debt instrument, term	'	'12 years	'7 years	'	'	'	'
Long-term debt	'	'	'	$37	'	'	'