Spirit Airlines (SAVEQ) 10-K 20 Feb 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2013	Feb. 07, 2014	Jun. 28, 2013
Document And Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
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 Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Public Float	'	'	$2.10
Entity Common Stock, Shares Outstanding	'	72,670,673	'

Statements_Of_Operations

Statements Of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating revenues:	'	'	'
Passenger	$986,018	$782,792	$689,650
Non-ticket	668,367	535,596	381,536
Total operating revenues	1,654,385	1,318,388	1,071,186
Operating expenses:	'	'	'
Aircraft fuel	551,746	471,763	388,046
Salaries, wages and benefits	262,150	218,919	181,742
Aircraft rent	169,737	143,572	116,485
Landing fees and other rents	83,604	68,368	52,794
Distribution	67,481	56,668	51,349
Maintenance, materials and repairs	60,143	49,460	34,017
Depreciation and amortization	31,947	15,256	7,760
Other operating	144,586	127,886	91,172
Loss on disposal of assets	525	956	255
Special charges (credits)	174	-8,450	3,184
Total operating expenses	1,372,093	1,144,398	926,804
Operating income	282,292	173,990	144,382
Other (income) expense:	'	'	'
Interest expense	214	1,350	24,781
Capitalized interest	-214	-1,350	-2,890
Interest income	-401	-925	-575
Other expense	283	331	235
Total other (income) expense	-118	-594	21,551
Income before income taxes	282,410	174,584	122,831
Provision for income taxes	105,492	66,124	46,383
Net income	$176,918	$108,460	$76,448
Basic earnings per share (in dollars per share)	$2.44	$1.50	$1.44
Diluted earnings per share (in dollars per share)	$2.42	$1.49	$1.43

Balance_Sheets

Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$530,631	$416,816
Accounts receivable, net	23,246	22,740
Deferred income taxes	16,243	12,591
Prepaid expense and other assets, current	78,955	95,210
Total current assets	649,075	547,357
Property and equipment:	'	'
Flight equipment	9,847	2,648
Ground and other equipment	50,987	43,580
Less accumulated depreciation	-25,221	-17,825
Total property and equipment	35,613	28,403
Deposits on flight equipment purchase contracts	157,669	96,692
Aircraft maintenance deposits	161,484	122,379
Deferred heavy maintenance, net	125,288	80,533
Other long-term assets	51,636	44,520
Total assets	1,180,765	919,884
Current liabilities:	'	'
Accounts payable	23,104	24,166
Air traffic liability	167,627	131,414
Other current liabilities	145,262	121,314
Total current liabilities	335,993	276,894
Long-term deferred income taxes	48,916	33,216
Deferred credits and other long-term liabilities	26,739	27,239
Shareholders’ equity:	'	'
Additional paid-in-capital	515,331	504,527
Treasury stock, at cost: 104,247 and 60,040 shares as of December 31, 2013 and 2012, respectively	-2,291	-1,151
Retained earnings	256,070	79,152
Total shareholders’ equity	769,117	582,535
Total liabilities and shareholders’ equity	1,180,765	919,884
Common Stock	'	'
Shareholders’ equity:	'	'
Common stock	7	6
Non-Voting Common Stock	'	'
Shareholders’ equity:	'	'
Common stock	$0	$1

Balance_Sheets_Parenthetical

Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Common Stock	'	'
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized	240,000,000	240,000,000
Common stock, shares issued	72,670,673	70,861,822
Common stock, shares outstanding	72,566,426	70,801,782
Non-Voting Common Stock	'	'
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	0	1,669,205
Common stock, shares outstanding	0	1,669,205

Statements_of_Cash_Flows

Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities:	'	'	'
Net income	$176,918	$108,460	$76,448
Adjustments to reconcile net income to net cash provided by operations:	'	'	'
Changes in fair value of open fuel hedge contracts	265	46	3,204
Non-cash restructuring credit charges, net	0	0	0
Equity based stock compensation, net	5,689	4,327	530
Allowance for doubtful accounts	143	78	27
Amortization of deferred gains, losses and debt issuance costs	-558	-830	-1,047
Depreciation and amortization	31,947	15,256	7,760
Deferred income tax benefit	12,047	29,255	44,180
Loss on disposal of assets	525	956	255
Gain on slot sale	0	-9,060	0
Interest and dividends incurred but not paid	0	0	21,875
Capitalized interest	-214	-1,350	-2,890
Changes in operating assets and liabilities:	'	'	'
Restricted cash	0	0	72,736
Accounts receivable	-461	-7,393	-5,728
Prepaid maintenance reserves	-24,058	-31,567	-36,848
Long-term deposits and other assets	-65,654	-68,248	-15,992
Accounts payable	-1,674	8,452	2,457
Air traffic liability	36,226	19,134	6,573
Other liabilities	24,235	46,115	-2,189
Other	0	0	-153
Net cash provided by operating activities	195,376	113,631	171,198
Investing activities:	'	'	'
Proceeds from sale of property and equipment	0	14	150
Proceeds from sale of slots	0	9,060	0
Pre-delivery deposits for flight equipment, net of refunds	-70,288	-12,626	-53,274
Purchase of property and equipment	-19,812	-23,771	-14,093
Net cash used in investing activities	-90,100	-27,323	-67,217
Financing activities:	'	'	'
Proceeds from issuance of common stock, net of offering expenses	0	0	170,828
Proceeds from options exercised	852	469	423
Payments on debt	0	0	-18,221
Proceeds from sale and leaseback transactions	6,900	12,540	4,481
Payments to pre-IPO shareholders pursuant to tax receivable agreement	0	-26,905	0
Excess tax benefits from share-based compensation	1,927	2,098	0
Repurchase of common stock	-1,140	-1,022	-886
Debt issuance costs	0	0	8
Net cash provided by (used in) financing activities	8,539	-12,820	156,633
Net increase in cash and cash equivalents	113,815	73,488	260,614
Cash and cash equivalents at beginning of period	416,816	343,328	82,714
Cash and cash equivalents at end of period	530,631	416,816	343,328
Cash payments for:	'	'	'
Interest	29	303	10,562
Taxes	85,705	40,204	1,477
Non-cash transactions:	'	'	'
Exchange of notes due to related parties for common stock	0	0	279,206
Exchange of mandatorily redeemable preferred stock for common stock	0	0	81,747
Liability and equity related to tax receivable agreement	-2,336	-1,497	36,522
Capital expenditures funded by capital lease borrowings	($3,234)	$0	$0

Statements_of_Shareholders_Equ

Statements of Shareholders’ Equity (Deficit) (USD $)	Total	Class A Common Stock	Class B Common Stock	Common Stock	Non- Voting Common Stock	Additional Paid-In Capital	Treasury Stock	Retained Earnings (Accumulated Deficit)
In Thousands, unless otherwise specified
Balance at Dec. 31, 2010	($105,077)	$2	$1	$0	$0	$676	$0	($105,756)
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'
Conversion of Class A & B common stock to common stock	'	-2	-1	3	'	'	'	'
Proceeds from initial public offering, net	170,828	'	'	1	'	170,827	'	'
Conversion of debt to common stock	279,206	'	'	2	'	279,204	'	'
Conversion of preferred stock to common stock	81,747	'	'	1	'	81,746	'	'
Record liability under Tax Receivable Agreement	-36,522	'	'	'	'	-36,522	'	'
Share-based compensation	530	'	'	'	'	530	'	'
Repurchase of common stock	-886	'	'	'	'	-757	-129	'
Conversion of common stock to non-voting common stock	0	'	'	-1	1	'	'	'
Proceeds from options exercised	423	'	'	'	'	423	'	'
Net income	76,448	'	'	'	'	'	'	76,448
Other	9	'	'	'	'	9	'	'
Balance at Dec. 31, 2011	466,706	0	0	6	1	496,136	-129	-29,308
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'
Net income	23,419	'	'	'	'	'	'	108,460
Balance at Mar. 31, 2012	'	'	'	'	'	'	'	'
Balance at Dec. 31, 2011	466,706	'	'	'	'	496,136	-129	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'
Adjustment to liability recorded under Tax Receivable Agreement	1,497	'	'	'	'	1,497	'	'
Share-based compensation	4,327	'	'	'	'	4,327	'	'
Repurchase of common stock	-1,022	'	'	'	'	'	-1,022	'
Proceeds from options exercised	469	'	'	'	'	469	'	'
Excess tax benefits from share-based compensation	2,098	'	'	'	'	2,098	'	'
Net income	108,460	'	'	'	'	'	'	'
Balance at Dec. 31, 2012	582,535	0	0	6	1	504,527	-1,151	79,152
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'
Adjustment to liability recorded under Tax Receivable Agreement	2,336	'	'	'	'	2,336	'	'
Share-based compensation	5,689	'	'	'	'	5,689	'	'
Repurchase of common stock	-1,140	'	'	'	'	'	-1,140	'
Conversion of non-voting common stock to common stock	0	'	'	1	-1	'	'	'
Proceeds from options exercised	852	'	'	'	'	852	'	'
Excess tax benefits from share-based compensation	1,927	'	'	'	'	1,927	'	'
Net income	176,918	'	'	'	'	'	'	176,918
Balance at Dec. 31, 2013	$769,117	$0	$0	$7	$0	$515,331	($2,291)	$256,070

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	Summary of Significant Accounting Policies
	Basis of Presentation
	Spirit Airlines, Inc. (Spirit or the Company) headquartered in Miramar, Florida, is an ultra low-cost, low-fare airline that provides affordable travel opportunities principally throughout the domestic United States, the Caribbean and Latin America. The Company manages operations on a system-wide basis due to the interdependence of its route structure in the various markets served. As only one service is offered (i.e., air transportation), management has concluded there is only one reportable segment.
	Certain prior period amounts have been reclassified to conform to the current year's presentation.
	Use of Estimates
	The preparation of financial statements in conformity with generally accepted accounting principles in the United States of America requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from these estimates.
	Cash and Cash Equivalents
	The Company considers all highly liquid investments with maturities of less than three months at the date of acquisition to be cash equivalents. Investments included in this category primarily consist of money market funds.
	Restricted Cash
	Restricted cash, when reported, can consist of funds held by credit card processors as collateral for future travel paid with a credit card.
	Accounts Receivable
	Accounts receivable primarily consist of amounts due from credit card processors associated with the sales of tickets and amounts due from counterparties associated with fuel derivative instruments which have settled. The Company records an allowance for doubtful accounts for amounts not expected to be collected. The Company estimates the allowance based on historical write offs and chargebacks as well as aging trends. The allowance for doubtful accounts was immaterial as of December 31, 2013, 2012 and 2011.
	In addition, the provision for doubtful accounts and write-offs for 2013, 2012 and 2011 were each immaterial.
	Property and Equipment
	Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation of operating property and equipment is computed using the straight-line method applied to each unit of property, except on flight equipment (major rotable parts, avionics and assemblies), which are depreciated on a group basis over the average life of the applicable equipment. Property under capital leases and related obligations are initially recorded at an amount equal to the present value of future minimum lease payments computed using the Company's incremental borrowing rate or, when known, the interest rate implicit in the lease. Amortization of property under capital leases is on a straight-line basis over the lease term and is included in depreciation and amortization expense. During 2012, the Company wrote off approximately $15.3 million in fully depreciated and out-of-service assets and recorded a corresponding entry to accumulated depreciation.
	The depreciable lives used for the principal depreciable asset classifications are:
		Estimated Useful Life
	Spare rotables and flight assemblies	Lesser of the useful life of equipment or average remaining fleet life
	Other equipment and vehicles	5 to 7 years
	Internal use software	3 to 10 years
	Capital lease	Lease term
	All aircraft and spare engines are financed through operating leases with terms of 3 to 15 years for aircraft and 7 to 12 years for spare engines. Residual values for major spare rotable parts, avionics and assemblies are estimated to be 10%.
	The following table illustrates the components of depreciation and amortization expense:
		Year Ended December 31,
		2013			2012			2011
		(in thousands)
	Depreciation	$	8,340		$	6,156		$	5,186
	Amortization of heavy maintenance	23,607			9,100			2,574
	Total depreciation and amortization	$	31,947		$	15,256		$	7,760
	The Company capitalizes certain internal and external costs associated with the acquisition and development of internal-use software for new products, and enhancements to existing products, that have reached the application development stage and meet recoverability tests. Capitalized costs include external direct costs of materials and services utilized in developing or obtaining internal-use software, and labor cost for employees who are directly associated with, and devote time, to internal-use software projects. Capitalized computer software, included as a component of ground and other equipment in the accompanying balance sheets, net of accumulated depreciation, was $8.1 million and $7.8 million at December 31, 2013 and 2012, respectively.
	Amortization of capitalized software development costs is charged to depreciation on a straight-line method basis. Amortization of capitalized software development costs was $3.7 million, $3.2 million and $2.0 million for the years ended 2013, 2012 and 2011, respectively. The Company placed in service internal-use software of $7.0 million, $2.3 million and $3.3 million, during the years ended 2013, 2012 and 2011, respectively.
	Measurement of Asset Impairments
	The Company records impairment charges on long-lived assets used in operations when events and circumstances indicate that the assets may be impaired, the undiscounted cash flows estimated to be generated by those assets are less than the carrying amount of those assets, and the net book value of the assets exceeds their estimated fair value. In making these determinations, the Company uses certain assumptions, including, but not limited to: (i) estimated fair value of the assets; and (ii) estimated, undiscounted future cash flows expected to be generated by these assets, which are based on additional assumptions such as asset utilization, length of service the asset will be used in the Company’s operations, and estimated salvage values.
	Capitalized Interest
	Capitalized interest represents interest cost incurred during the acquisition period of an aircraft which theoretically could have been avoided had the Company not made purchase delivery deposits (PDPs) for that aircraft. These amounts are capitalized as part of the cost of the aircraft upon delivery. Capitalization of interest ceases when the asset is ready for service.
	Passenger Revenue Recognition
	Tickets sold are initially deferred as “air traffic liability.” Passenger revenue is recognized at time of departure when transportation is provided. A nonrefundable ticket expires at the date of scheduled travel and is recognized as revenue at the date of scheduled travel.
	Customers may elect to change their itinerary prior to the date of departure. A service charge is assessed and recognized on the date the change is initiated and is deducted from the face value of the original purchase price of the ticket, and the original ticket becomes invalid. The amount remaining after deducting the service charge is called a credit shell which expires 60 days from the date the credit shell is created and can be used towards the purchase of a new ticket and the Company’s other service offerings. The amount of credits expected to expire is recognized as revenue upon issuance of the credit and is estimated based on historical experience. Estimating the amount of credits that will go unused involves some level of subjectivity and judgment.
	The Company is also required to collect certain taxes and fees from customers on behalf of government agencies and airports and remit these back to the applicable governmental entity or airport on a periodic basis. These taxes and fees include U.S. federal transportation taxes, federal security charges, airport passenger facility charges and foreign arrival and departure taxes. These items are collected from customers at the time they purchase their tickets, but are not included in passenger revenue. The Company records a liability upon collection from the customer and relieves the liability when payments are remitted to the applicable governmental agency or airport.
	Frequent Flier Program
	Flown Miles. The Company records a liability for mileage credits earned by passengers under its FREE SPIRIT program, including mileage credits for members with an insufficient number of mileage credits to earn an award, based on the estimated incremental cost of providing free travel for credits that are expected to be redeemed. Incremental costs include fuel, insurance, security, ticketing and facility charges reduced by an estimate of fees required to be paid by the passenger when redeeming the award.
	Affinity Card Program. Under the Company's affinity card program, funds received for the marketing of a co-branded Spirit credit card and delivery of award miles are accounted for as a mulitple-deliverable arrangement. At the inception of the arrangement, the Company evaluated all deliverables in the arrangement to determine whether they represent separate units of accounting using the criteria as set forth in ASU No. 2009-13. The Company determined the arrangement had three separate units of accounting: (i) travel miles to be awarded, (ii) licensing of brand and access to member lists and (iii) advertising and marketing efforts. Under ASU No. 2009-13, arrangement consideration was allocated based on relative selling price. At inception of the arrangement, the Company established the relative selling price for all deliverables that qualified for separation. The manner in which the selling price was established was based on a hierarchy of evidence that the Company considered. Total arrangement consideration was then allocated to each deliverable on the basis of the deliverable’s relative selling price. In considering the hierarchy of evidence under ASU No. 2009-13, the Company first determined whether vendor specific objective evidence of selling price or third-party evidence of selling price existed. It was determined by the Company that neither vendor specific objective evidence of selling price nor third-party evidence existed due to the uniqueness of the Company’s program. As such, the Company developed its best estimate of the selling price for all deliverables. For the award miles, the Company considered a number of entity-specific factors when developing the best estimate of the selling price including the number of miles needed to redeem an award, average fare of comparable segments, breakage, restrictions and other charges. For licensing of brand and access to member lists, the Company considered both market-specific factors and entity-specific factors including general profit margins realized in the marketplace/industry, brand power, market royalty rates and size of customer base. For the advertising element, the Company considered market-specific factors and entity-specific factors, including the Company’s internal costs (and fluctuations of costs) of providing services, volume of marketing efforts and overall advertising plan. Consideration allocated based on the relative selling price to both brand licensing and advertising elements is recognized as revenue when earned and recorded in non-ticket revenue. Consideration allocated to award miles is deferred and recognized ratably as passenger revenue over the estimated period the transportation is expected to be provided which is estimated at 16 months. The Company used entity-specific assumptions coupled with the various judgments necessary to determine the selling price of a deliverable in accordance with the required selling price hierarchy. Changes in these assumptions could result in changes in the estimated selling prices. Determining the frequency to reassess selling price for individual deliverables requires significant judgment. As of December 31, 2013, there have been no changes in either the selling price or the method or assumptions used to determine selling price for any of the identified units of accounting that would have a significant effect on the allocation of consideration.
	The following table illustrates total cash proceeds received from the sale of mileage credits and the portion of such proceeds recognized in revenue immediately as marketing component:
		Cash proceeds from sale of miles to non-airline third parties			Portion of proceeds recognized immediately as marketing component
	Year Ended	(in thousands)
	December 31, 2013	$	28,496		$	23,124
	December 31, 2012	24,938			20,998
	December 31, 2011	20,954			16,580
	The total liability for future FREE SPIRIT award redemptions and unrecognized revenue from the sale of mileage credits was $2.6 million and $2.4 million at December 31, 2013 and 2012, respectively. These balances are recorded as a component of air traffic liability in the accompanying balance sheets.
	Non-ticket Revenue Recognition
	Non-ticket revenues are generated from air travel-related services for baggage, bookings through the Company’s call center or third-party vendors, advance seat selection, itinerary changes and loyalty programs. Non-ticket revenues also consist of services not directly related to providing transportation such as the FREE SPIRIT affinity credit card program, $9 Fare Club and the sale of advertising to third parties on Spirit’s website and on board aircraft.
	The following table summarizes the primary components of non-ticket revenue and the revenue recognition method utilized for each service or product:
			Year Ended December 31,
	Non-ticket revenue	Recognition method	2013			2012			2011
			(in thousands)
	Baggage	Time of departure	$	275,958		$	217,536		$	168,290
	Passenger usage fee	Time of departure	188,911			149,577			71,757
	Advance seat selection	Time of departure	59,241			48,956			42,112
	Service charges for changes and cancellations	When itinerary is changed	32,546			27,762			25,927
	Other		111,711			91,765			73,450
	Non-ticket revenue		$	668,367		$	535,596		$	381,536
	Charges for services recognized at time of departure are initially recorded as a liability until time of departure. The passenger usage fee is charged for tickets sold through the Company’s primary sales distribution channels, to cover the Company’s distribution costs. The primary sales distribution channels for which passenger usage fees are charged include sales through the Company’s website, sales through the third-party provided call center and sales through travel agents; the Company does not charge a passenger usage fee for sales made at its airport ticket counters. Other non-ticket revenues include revenues from other air related charges as well as non-air related charges. Other air related charges include optional services and products provided to passengers such as on-board products, travel insurance and use of the Company’s call center or travel agents, among others. Non-air related charges primarily consist of revenues from advertising on the Company’s aircraft and website, the Company’s $9 Fare Club subscription-based membership program and the Company’s FREE SPIRIT affinity credit card program.
	Airframe and Engine Maintenance
The Company accounts for heavy maintenance and major overhaul and repair under the deferral method whereby the cost of heavy maintenance and major overhaul and repair is deferred and amortized until the earlier of the end of the remaining lease term or until the next scheduled heavy maintenance event.
Amortization of heavy maintenance and major overhaul costs is charged to depreciation and amortization expense and was $23.6 million, $9.1 million and $2.6 million for the years ended 2013, 2012 and 2011, respectively. During the years ended 2013, 2012 and 2011, the Company deferred $70.8 million, $61.6 million and $22.1 million, respectively, of costs for heavy maintenance. At December 31, 2013 and 2012, the Company had deferred heavy maintenance balance of $165.3 million and $94.5 million, and accumulated heavy maintenance amortization of $40.0 million and $14.0 million, respectively.
On October 15, 2013, the Company had an aircraft experience 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. The Company anticipates it will recover insurance proceeds to cover the expenses related to this incident and therefore it has expensed the insurance deductible of approximately $0.8 million recorded within maintenance, materials and repairs expense.
The Company outsources certain routine, non-heavy maintenance functions under contracts that require payment on a utilization basis, such as flight hours. Costs incurred for maintenance and repair under flight hour maintenance contracts, where labor and materials price risks have been transferred to the service provider, are expensed based on contractual payment terms. All other costs for routine maintenance of the airframes and engines are charged to expense as performed.
The table below summarizes the extent to which the Company’s maintenance costs are rate capped due to flight hour maintenance contracts:
	Year Ended December 31,
	2013			2012			2011
	(in thousands)
Flight hour-based maintenance expense	$	30,322		$	25,748		$	21,974
Non-flight hour-based maintenance expense	29,821			23,712			12,043
Total maintenance, materials and repairs	$	60,143		$	49,460		$	34,017
Leased Aircraft Return Costs
Costs associated with returning leased aircraft are accrued when it is probable that a cash payment will be made and that amount is reasonably estimable. Leased aircraft return costs are recorded as a component of aircraft rent and characterized as supplemental rent. Any accrual is based on time remaining on the lease, planned aircraft usages and the provisions included in the lease agreement, although the actual amount due to any lessor upon return will not be known with certainty until lease termination.
Aircraft Fuel
Aircraft fuel expense includes jet fuel and associated “into-plane” costs, taxes, oil and all gains and losses associated with fuel hedge contracts.
Derivative Instruments
The Company accounts for derivative financial instruments at fair value and recognizes them in the balance sheet in prepaid expenses and other current assets or other current liabilities. For derivatives designated as cash flow hedges, changes in fair value of the derivative are generally reported in other comprehensive income and are subsequently reclassified into earnings when the hedged item affects earnings. For the years ended 2013, 2012 and 2011, the Company did not hold derivative instruments that qualified as cash flow hedges for accounting purposes. As a result, changes in the fair value of such derivative contracts were recorded within aircraft fuel expense in the accompanying statements of operations. These amounts include both realized gains and losses and mark-to-market adjustments of the fair value of unsettled derivative instruments at the end of each period.
Advertising
The Company expenses advertising and the production costs of advertising as incurred. Marketing and advertising expenses were $2.1 million, $2.4 million and $2.5 million for the years ended 2013, 2012 and 2011, respectively.
Income Taxes
The Company accounts for income taxes using the liability method. The Company records a valuation allowance to reduce the deferred tax assets reported if, based on the weight of the evidence, it is more likely than not that some portion or all of the deferred tax assets will be not realized.
Interest Expense
Related-party interest expense incurred during 2013, 2012 and 2011 was $0.0 million, $0.0 million and $21.0 million, respectively, and consisted primarily of paid-in-kind interest on tranche notes due to related parties, and preferred stock dividends due to related parties. Non-related party interest expense during 2013, 2012 and 2011 was $0.2 million, $1.4 million and $3.8 million, respectively.
Stock-Based Compensation
The Company recognizes cost of employee services received in exchange for awards of equity instruments based on the fair value of each instrument at the date of grant. Compensation expense is recognized on a straight-line basis over the period during which an employee is required to provide service in exchange for an award. The Company has issued and outstanding restricted stock awards, stock option awards and performance share awards. Restricted stock awards are valued at the fair value of the shares on the date of grant. To the extent a market price was not available, the fair value of stock awards was estimated using a discounted cash flow analysis based on management’s estimates of revenue, driven by assumed market growth rates and estimated costs as well as appropriate discount rates. These estimates are consistent with the plans and estimates that management uses to manage the Company’s business. The fair value of share option awards is estimated on the date of grant using the Black-Scholes valuation model. The fair value of performance share awards is estimated through the use of a Monte Carlo simulation model. See Note 8 for additional information.
Concentrations of Risk
The Company’s business has been, and may continue to be, adversely affected by increases in the price of aircraft fuel, the volatility of the price of aircraft fuel, or both. Aircraft fuel was the Company’s single largest expenditure representing approximately 40%, 41% and 42% of total operating expenses in 2013, 2012 and 2011, respectively.
The Company’s operations are largely concentrated in the southeast United States with Fort Lauderdale being the highest volume fueling point in the system. Gulf Coast Jet indexed fuel is the basis for a substantial majority of the Company’s fuel consumption. Any disruption to the oil production or refinery capacity in the Gulf Coast, as a result of weather or any other disaster, or disruptions in supply of jet fuel, dramatic escalations in the costs of jet fuel and/or the failure of fuel providers to perform under fuel arrangements for other reasons could have a material adverse effect on the Company’s financial condition and results of operations.
The Company’s operations will continue to be vulnerable to weather conditions (including hurricane season or snow and severe winter weather), which could disrupt service, create air traffic control problems, decrease revenue and increase costs.
Due to the relatively small size of the fleet and high utilization rate, the unavailability of one or more aircraft and resulting reduced capacity could have a material adverse effect on the Company’s business, results of operations and financial condition.
The Company has three union-represented employee groups that together represent approximately 59% and 54% of all employees at December 31, 2013 and 2012, respectively. A strike or other significant labor dispute with the Company’s unionized employees is likely to adversely affect the Company’s ability to conduct business. Additional disclosures are included in Note 15.

Recent_Accounting_Developments

Recent Accounting Developments	12 Months Ended
	Dec. 31, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Recent Accounting Developments	'
	Recent Accounting Developments
	In December 2011, the FASB issued amendments to Accounting Standards Update No. 2011-11, Balance Sheet (Topic 210); Disclosures about Offsetting Assets and Liabilities (ASU 2011-11). The amendments in this update are designed to enhance disclosures by requiring improved information about financial instruments and derivative instruments that are either (a) offset in accordance with certain right to set-off conditions prescribed by current accounting guidance or (b) subject to an enforceable master netting arrangement or similar agreement, irrespective of whether they are offset in accordance with current accounting guidance. In January 2013, the FASB issued Accounting Standards Update No. 2013-01, Scope Clarification of Disclosures about Offsetting Assets and Liabilities (ASU 2013-01), to limit the scope of ASU 2011-11, and its new balance sheet offsetting disclosure requirements to derivatives (including bifurcated embedded derivatives), repurchase agreements and reverse repurchase agreements and securities borrowing and lending transactions. ASU 2011-11 and ASU 2013-01 became effective for the Company's annual and interim periods beginning January 1, 2013, and the required disclosures are included in Note 16 of this report.

Special_Charges_and_Credits

Special Charges and Credits	12 Months Ended
	Dec. 31, 2013
Restructuring and Related Activities [Abstract]	'
Special Charges and Credits	'
	Special Charges and Credits
	Slot Transaction and Restructuring
	In 2012, the Company sold four permanent air carrier slots at Ronald Reagan National Airport (DCA) to another airline for $9.1 million. The Company recognized the $9.1 million gain within special charges (credits) in the third quarter of 2012, the period in which the FAA operating restriction lapsed and written confirmation of the slot transfer was received by the buyer from the FAA.
	In 2013, the Company incurred an additional $0.1 million of cost in connection with the DCA exit and relieved $0.2 million of previously accrued exit cost in connection with Chicago O'Hare (ORD).
	Secondary Offering Costs
	In the third quarter of 2013, the Company incurred costs of $0.3 million, recorded within special charges (credits), related to an underwritten public offering of 12,070,920 shares of common stock by certain stockholders affiliated with Indigo Partners LLC (Indigo). Upon completion of this offering, investment funds affiliated with Indigo owned no shares of common stock of Spirit Airlines. The Company did not receive any proceeds from this offering.
	In the third quarter of 2012, the Company incurred costs of $0.7 million, recorded within special charges (credits), related to an underwritten public offering of 9,394,927 shares of common stock by certain stockholders affiliated with Oaktree Capital Management (Oaktree). Upon completion of this offering, investment funds affiliated with Oaktree owned no shares of common stock of Spirit Airlines. The Company did not receive any proceeds from this offering.
	In January 2012, certain stockholders of the Company, including affiliates of Oaktree and Indigo Partners, LLC (Indigo) and certain members of the Company's executive team, sold an aggregate of 12,650,000 shares of common stock in an underwritten public offering. The Company incurred a total of $1.3 million in costs between 2011 and 2012 related to this offering, of which $0.5 million were incurred during the year ended December 31, 2012, offset by reimbursements from certain selling shareholders of $0.6 million in accordance with the Fourth Amendment to the Second Amended and Restated Investor Rights Agreement. The Company did not receive any proceeds from this offering.
	Initial Public Offering Costs
	In June 2011, the Company issued and sold 15,600,000 shares of common stock in its initial public offering (IPO). The Company incurred contract termination costs and fees of $2.3 million in connection with the IPO during the year ended December 31, 2011, which included $1.8 million paid to Indigo to terminate its professional services agreement with the Company, and $0.5 million paid to three individual, unaffiliated holders of the Company’s subordinated notes.

Letters_of_Credit

Letters of Credit	12 Months Ended
	Dec. 31, 2013
Letters of Credit [Abstract]	'
Letters of Credit	'
	Letters of Credit
	In connection with agreements with certain airports, the Company is required to post letters of credit, which totaled $0.2 million as of both December 31, 2013 and 2012. The issuing banks require that the Company deposit funds at those banks to cover the amounts that could be drawn under the letters of credit. These funds are generally invested in money market accounts and are classified as long-term assets within other long-term assets. Additionally, as of December 31, 2013, the Company had a $25.1 million unsecured standby letter of credit facility, representing an off balance-sheet commitment, of which $10.4 million had been drawn upon for issued letters of credit to airports and insurance underwriters.

Credit_Card_Processing_Arrange

Credit Card Processing Arrangements	12 Months Ended
	Dec. 31, 2013
Credit Card Processing Arrangements [Abstract]	'
Credit Card Processing Arrangements	'
	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 that its credit card processors hold to cover refunds to customers if the Company fails to fulfill its flight obligations.
	During 2011, the Company amended its processing agreements with all of its processors. Prior to the amendments, the credit card processors required the Company to maintain cash collateral equal to approximately 100% of the Company's air traffic liability. The amendments were approved in light of the Company's improved balance sheet as a result of the IPO, the related recapitalization and the elimination of the holdback held by the credit card processors, effectively eliminating the Company's restricted cash balance, provided that the Company continues to satisfy certain liquidity and other financial covenants. Failure to meet these covenants would provide the processors the right to reinstate a holdback, resulting in a commensurate reduction of unrestricted cash. As of December 31, 2013 and 2012, the Company continued to be in compliance with its credit card processing agreements, and the processors were holding back $0 of 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 December 31, 2013 and 2012, was $188.6 million and $144.8 million, respectively.

Accrued_Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2013
Payables and Accruals [Abstract]	'
Accrued Liabilities	'
	Accrued Liabilities
	Accrued liabilities included in other current liabilities as of December 31, 2013 and 2012 consist of the following:
		As of December 31,
		2013		2012
		(in thousands)
	Aircraft maintenance	$	36,165	$	22,319
	Federal excise and other passenger taxes and fees payable	26,979		23,401
	Salaries and wages	26,174		21,057
	Airport expenses	17,109		16,024
	Fuel	13,819		11,219
	Aircraft and facility rent	7,993		8,020
	Tax receivable agreement	5,643		7,987
	Other	11,380		11,287
	Other current liabilities	$	145,262	$	121,314

Common_Stock_and_Preferred_Sto

Common Stock and Preferred Stock	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity Note [Abstract]	'
Common Stock and Preferred Stock	'
	Common Stock and Preferred Stock
	The Company’s amended and restated certificate of incorporation dated June 1, 2011, authorizes the Company to issue up to 240,000,000 shares of common stock, $0.0001 par value per share, 50,000,000 shares of non-voting common stock, $0.0001 par value per share and 10,000,000 shares of preferred stock, $0.0001 par value per share. All of the Company’s issued and outstanding shares of common stock and preferred stock are duly authorized, validly issued, fully paid and non-assessable. The Company’s shares of common stock and non-voting common stock are not redeemable and do not have preemptive rights.
	Common Stock
	Dividend Rights. Holders of the Company’s common stock are entitled to receive dividends, if any, as may be declared from time to time by the Company’s board of directors out of legally available funds ratably with shares of the Company’s non-voting common stock, subject to preferences that may be applicable to any then outstanding preferred stock and limitations under Delaware law.
	Voting Rights. Each holder of the Company’s common stock is entitled to one vote for each share on all matters submitted to a vote of the stockholders, including the election of directors. The Company’s stockholders do not have cumulative voting rights in the election of directors. Accordingly, holders of a majority of the voting shares are able to elect all of the directors properly up for election at any given stockholders’ meeting.
	Liquidation. In the event of the Company’s liquidation, dissolution or winding up, holders of the Company's common stock will be entitled to share ratably with shares of the Company’s non-voting common stock in the net assets legally available for distribution to stockholders after the payment of all of the Company’s debts and other liabilities and the satisfaction of any liquidation preference granted to the holders of any then outstanding shares of preferred stock.
	Rights and Preferences. Holders of the Company’s common stock have no preemptive, conversion, subscription or other rights and there are no redemption or sinking fund provisions applicable to the Company’s common stock. The rights, preferences and privileges of the holders of the Company’s common stock are subject to and may be adversely affected by, the rights of the holders of shares of any series of the Company’s preferred stock that the Company may designate in the future.
	Non-Voting Common Stock
	Dividend Rights. Holders of the Company’s non-voting common stock are entitled to receive dividends, if any, as may be declared from time to time by the Company’s board of directors out of legally available funds ratably with shares of the Company’s common stock, subject to preferences that may be applicable to any then outstanding preferred stock and limitations under Delaware law.
	Voting Rights. Shares of the Company’s non-voting common stock are not entitled to vote on any matters submitted to a vote of the stockholders, including the election of directors, except to the extent required under Delaware law.
	Conversion Rights. Shares of the Company’s non-voting common stock will be convertible on a share-for-share basis into common stock at the election of the holder subject to the Company remaining in compliance with applicable foreign ownership limitations.
	Liquidation. In the event of the Company’s liquidation, dissolution or winding up, holders of the Company’s non-voting common stock will be entitled to share ratably with shares of the Company’s common stock in the net assets legally available for distribution to stockholders after the payment of all of the Company’s debts and other liabilities and the satisfaction of any liquidation preference granted to the holders of any then outstanding shares of preferred stock.
	Rights and Preferences. Holders of the Company’s non-voting common stock have no preemptive, subscription or other rights, and there are no redemption or sinking fund provisions applicable to the Company’s common stock. The rights, preferences and privileges of the holders of the Company’s common stock are subject to and may be adversely affected by, the rights of the holders of shares of any series of the Company’s preferred stock that the Company may designate in the future.
	On December 7, 2011, the Company entered into a Stock Distribution Agreement with Indigo Miramar LLC and its members. Pursuant to the Stock Distribution Agreement 10,576,180 shares of outstanding common stock were exchanged on a share-for-share basis for shares of non-voting common stock. As of December 31, 2012, the number of outstanding non-voting common stock had decreased to 1,669,205. In February 2013, all of the remaining outstanding shares of non-voting common stock were converted to voting shares in accordance with the Stock Distribution Agreement. As of December 31, 2013, there were no shares of non-voting common stock outstanding.
	Preferred Stock
	The Company’s board of directors has the authority, without further action by the Company’s stockholders, to issue up to 10,000,000 shares of preferred stock in one or more series and to fix the rights, preferences, privileges and restrictions thereof. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting any series or the designation of such series, any or all of which may be greater than the rights of common stock. The Company’s issuance of preferred stock could adversely affect the voting power of holders of common stock and the likelihood that such holders will receive dividend payments and payments upon liquidation. In addition, the issuance of preferred stock could have the effect of delaying, deferring or preventing a change of control of the Company or other corporate action. As of December 31, 2013 and 2012, there were no shares of preferred stock outstanding.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation	'
	Stock-Based Compensation
	The Company has stock plans under which directors, officers, key employees and consultants of the Company may be granted restricted stock awards, stock options and other equity-based instruments as a means of promoting the Company’s long-term growth and profitability. The plans are intended to encourage participants to contribute to and participate in the success of the Company.
	The Company's board of directors adopted, and the Company's stockholders approved, the Amended and Restated 2005 Incentive Stock Plan, or the 2005 Stock Plan, effective January 1, 2008. The total number of shares of common stock authorized for issue pursuant to awards granted under the 2005 Stock Plan was 2,500,000 shares. The 2005 Stock Plan provided for the grant of non-qualified stock options, stock appreciation rights, restricted stock, performance shares, phantom stock, restricted stock units and other awards that are valued in whole or in part by reference to the Company's stock.
	On May 9, 2011, the Company's board of directors adopted, and the Company's stockholders approved, the 2011 Equity Incentive Award Plan, or 2011 Plan. Under the 2011 Plan, 3,000,000 new shares of common stock are reserved for issuance pursuant to a variety of stock-based compensation awards, including stock options, stock appreciation rights or SARs, restricted stock awards, restricted stock unit awards, deferred stock awards, dividend equivalent awards, stock payment awards and performance share awards and other stock-based awards, plus the number of shares remaining available for future awards under the Company's 2005 Stock Plan. The number of shares reserved for issuance or transfer pursuant to awards under the 2011 Plan will be increased by the number of shares represented by awards outstanding under the Company's 2005 Stock Plan that are forfeited or lapse unexercised and which, following the effective date of the 2011 Plan, are not issued under the Company's 2005 Stock Plan. No further awards will be granted under the 2005 Stock Plan, and all outstanding awards will continue to be governed by their existing terms. As of December 31, 2013 and December 31, 2012, 2,685,029 and 2,689,490 shares of the Company’s common stock, respectively, remained available for future issuance under the 2011 Plan.
	Stock-based compensation cost is included within salaries, wages and benefits in operating expenses in the accompanying statements of operations. Stock-based compensation cost amounted to $5.7 million, $4.3 million and $0.5 million for 2013, 2012 and 2011, respectively. During 2013, 2012 and 2011, there was $2.1 million, $1.6 million and $0.2 million tax benefit recognized in income related to stock-based compensation, respectively.
	Restricted Stock
	Restricted stock and restricted stock unit awards are valued at the fair value of the shares on the date of grant. Generally, granted shares and units vest 25% per year on each anniversary of issuance. Each restricted stock unit represents the right to receive one share of common stock upon vesting of such restricted stock unit. Compensation expense, net of forfeitures, is recognized on a straight-line basis over the requisite service period.
	A summary of the status of the Company’s restricted stock shares (restricted stock awards and restricted stock unit awards) as of December 31, 2013 and changes during the year ended December 31, 2013 is presented below:
		Number of Shares			Weighted-Average
					Grant Date Fair Value ($)
	Outstanding at December 31, 2012	449,629			16.94
	Granted	151,202			27.7
	Vested	(168,514	)		13.19
	Forfeited	(96,269	)		19.28
	Outstanding at December 31, 2013	336,048			22.99
	There were 151,202 and 391,418 restricted stock shares granted during the years ended December 31, 2013 and December 31, 2012, respectively. As of December 31, 2013 and December 31, 2012, there was $6.1 million and $6.1 million, respectively, of total unrecognized compensation cost related to nonvested restricted stock to be recognized over 2.7 years and 3.2 years, respectively.
	The weighted-average fair value of restricted stock granted during the years ended December 31, 2013 and 2012 was $27.70 and $20.01, respectively. There was no restricted stock granted during the year ended December 31, 2011. The total fair value of restricted stock shares vested during the years ended December 31, 2013, 2012 and 2011 was $4.3 million, $3.9 million and $3.2 million respectively.
	Stock Options
	Stock option awards are granted with an exercise price equal to the fair market value of the Company’s common stock at the date of grant, vest over four years of continuous service and have ten-year contractual terms. The fair value of each stock option award is estimated on the date of grant using the Black Scholes model. There were no options granted during 2013 or 2012. For option grants during 2011, the Company’s weighted average assumptions for expected volatility, dividends, term and risk-free interest rate were 46.25%, 0%, 6.25 years and 2.03%, respectively. Expected volatilities are based on the historical volatility of a group of peer entities within the same industry. The expected term of options is based upon the simplified method, which represents the average of the vesting term and the contractual term. The risk-free interest rate is based on U.S. Treasury yields for securities with terms approximating the expected term of the option.
	Prior to the Company's IPO, to the extent a market price was not available, the fair value of the Company’s common stock was estimated using a discounted cash flow analysis and market multiples, based on management’s estimates of revenue, driven by assumed market growth rates, and estimated costs as well as appropriate discount rates. These estimates are consistent with the plans and estimates management uses to manage the Company’s business.
	A summary of share option activity under the 2011 Plan as of December 31, 2013 and changes during the year ended December 31, 2013 is presented below:
		Number			Weighted-	Average	Aggregate
		of Options			Average	Remaining	Intrinsic
					Exercise	Contractual	Value
					Price ($)	Term	$0
						(Years)
	Outstanding at December 31, 2012	247,650			9.59	8	2,015
	Exercised	(92,400	)		9.22
	Forfeited or expired	(98,750	)		10.7
	Outstanding at December 31, 2013	56,500			8.26	6.7	2,099
	Exercisable at December 31, 2013	27,125			8.12	6.6	1,011
	Vested or Expected to Vest at December 31, 2013	56,260			8.25	6.7	2,090
	There were no options granted during the years ended December 31, 2013 or 2012. The weighted-average fair value of option awards granted during the year ended December 31, 2011 was $5.73. The total intrinsic value of share options exercised during the years ended December 31, 2013, 2012 and 2011 was $2.0 million, $0.7 million and $0.2 million, respectively. The total fair value of shares vested during the years ended December 31, 2013, 2012 and 2011 was $0.2 million, $0.4 million and $0.3 million, respectively.
	As of December 31, 2013 and December 31, 2012, there was $46.7 thousand and $650.5 thousand respectively, of total unrecognized compensation cost related to options expected to be recognized over 0.8 years and 1.99 years, respectively.
	Performance Share Awards
	During 2013 and 2012, the Company granted certain senior-level executives restricted stock units that vest based on market and service conditions as part of a long-term incentive plan, which are referred to herein as performance share awards. The number of shares of common stock underlying each award is determined at the end of a three-year performance period. In order to vest, the senior level executive must still be employed by the Company, with certain contractual exclusions, at the end of the performance period. At the end of the performance period, the percentage of the stock units that will vest will be determined by ranking the Company’s total shareholder return compared to the total shareholder return of the nine peer companies identified in the plan. Based on the level of performance, between 0% and 200% of the award may vest. Within 60 days after vesting, the shares underlying the award will be issued to the participant. In the event of a change in control of the Company or the disability or death of a participant, the payout of any award is limited to a pro-rated portion of such award based upon a performance assessment prior to the change-in-control date or date of disability or death.
	The market condition requirements are reflected in the grant date fair value of the award, and the compensation expense, net of forfeitures, for the award will be recognized assuming that the requisite service is rendered regardless of whether the market conditions are achieved.
	The grant date fair value of the performance share awards was determined through the use of a Monte Carlo simulation model, which utilizes multiple input variables that determine the probability of satisfying the market condition requirements applicable to each award as follows:
		Weighted-Average at Grant Date for Year Ended December 31, 2013		Weighted-Average at Grant Date for Year Ended December 31, 2012
	Expected volatility factor	0.41		0.39
	Risk free interest rate	0.33	%	0.44	%
	Expected term (in years)	2.65		2.72
	Expected dividend yield	—	%	—	%
	The volatility was based upon a weighted average of the volatility for the Company and the most recent volatility of the peer group. The peer group used to calculate volatility is consistent with the group used for the traditional employee stock options. The Company chose to use historical volatility to value these awards because historical stock prices were used to develop the correlation coefficients between the Company and each of the peer companies within the peer group in order to model stock price movements. The volatilities used were calculated as the remaining term of the performance period at the date of grant. The risk-free interest rate was based on the implied yield available on U.S. Treasury zero-coupon issues with remaining terms equivalent to the remaining performance period. The Company does not intend to pay dividends on its common stock in the foreseeable future. Accordingly, the Company used a dividend yield of zero in its model.
	The following table summarizes the Company’s performance share awards for the year ended December 31, 2013:
		Number of Awards			Weighted-Average Fair Value at Grant Date ($)
	Outstanding at December 31, 2012	280,907			20.3
	Granted	126,147			28.09
	Vested	—			—
	Forfeited	(79,950	)		21.76
	Outstanding at December 31, 2013	327,104			22.94
	As of December 31, 2013 and December 31, 2012, there was $6.5 million and $6.9 million, respectively, of total unrecognized compensation cost related to performance share awards expected to be recognized over 1.54 years and 2.0 years, respectively.

Net_Income_per_Share_Net_Incom

Net Income per Share Net Income per Share	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Net Income per Share	'
	Net Income per Share
	The following table sets forth the computation of basic and diluted earnings per common share:
		Year Ended December 31,
		2013		2012		2011
		(in thousands, except per share amounts)
	Numerator:
	Net income	$	176,918	$	108,460	$	76,448
	Denominator:
	Weighted-average shares outstanding, basic	72,593		72,386		53,241
	Effect of dilutive stock awards	406		205		274
	Adjusted weighted-average shares outstanding, diluted	72,999		72,591		53,515
	Net Income per Share:
	Basic earnings per common share	$	2.44	$	1.5	$	1.44
	Diluted earnings per common share	$	2.42	$	1.49	$	1.43
	Anti-dilutive weighted-average shares	1		88		70

Debt_RelatedParty_Transactions

Debt, Related-Party Transactions and Other Obligations	12 Months Ended
	Dec. 31, 2013
Debt and Related Party Transactions Disclosure [Abstract]	'
Debt, Related-Party Transactions and Other Obligations	'
	Debt, Related-Party Transactions and Other Obligations
	In connection with the closing of the IPO, the Company consummated the transaction contemplated by the Recapitalization Agreement on June 1, 2011, which resulted in the repayment or exchange for common stock of all of the Company’s notes and preferred stock. The Company’s principal stockholders provided certain consulting services to the Company for a management fee of $0.3 million in 2011. In connection with the IPO, the management fee agreement with the Company's principal stockholders was terminated. See Note 18.
	As of December 31, 2013 and 2012, there was no outstanding long term debt or outstanding amounts due to related parties. During the fourth quarter of 2013, the Company executed an agreement for the lease of two quick engine change kits (QEC kit), classified as capital leases. Aggregate annual principal maturities of capital leases as of December 31, 2013, were $1.0 million in 2014, $1.1 million in 2015, $1.0 million in 2016, $0.0 million in 2017 and $0.0 million in 2018 and $0.0 million in 2019 and beyond. As of December 31, 2012, the Company had no outstanding amounts related to capital leases.
	The Company had a line of credit for $18.6 million and $18.6 million related to corporate credit cards, of which the Company had drawn $3.7 million and $3.2 million as of December 31, 2013 and 2012, respectively, which is included in accounts payable.
	As of December 31, 2013, the Company had lines of credit with counterparties for both physical fuel delivery and jet fuel derivatives in the amount of $34.5 million. As of December 31, 2013, the Company had drawn $13.8 million on these lines of credit, which is included in other current liabilities. As of December 31, 2012, the Company had lines of credit with counterparties for both physical fuel delivery and jet fuel derivatives in the amount $18.0 million. As of December 31, 2012, the Company had drawn $11.2 million on these lines of credit, which is included in other current liabilities. The Company is required to post collateral for any excess above the lines of credit if the derivatives are in a net liability position and make periodic payments in order to maintain an adequate undrawn portion for physical fuel delivery.

Leases_and_Prepaid_Maintenance

Leases and Prepaid Maintenance Deposits	12 Months Ended
	Dec. 31, 2013
Leases And Prepaid Maintenance Deposits [Abstract]	'
Leases and Prepaid Maintenance Deposits	'
	Leases and Prepaid Maintenance Deposits
	The Company leases various types of equipment and property, primarily aircraft, spare engines and airport facilities under leases, which expire in various years through 2032. Lease terms are generally 3 to 15 years for aircraft and up to 25 years for other leased equipment and property.
	Total rental expense for all leases charged to operations for the years ended 2013, 2012 and 2011 was $207.4 million, $172.4 million and $139.1 million, respectively. Total rental expense charged to operations for aircraft and engine operating leases for the years ended December 31, 2013, 2012 and 2011 was $169.7 million, $143.6 million and $116.5 million, respectively. 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 and probable return condition obligations. The Company expensed $5.2 million, $2.0 million and $1.5 million of supplemental rent recorded within aircraft rent during 2013, 2012 and 2011, respectively.
	Some 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. Some maintenance reserve payments are fixed contractual amounts, while others are based on actual flight hours. Fixed maintenance reserve payments for these aircraft and related flight equipment, including estimated amounts for contractual price escalations, will be approximately $7.4 million in 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. Substantially all of these maintenance reserve payments are calculated based on a utilization measure, such as flight hours or cycles, and are used solely to collateralize the lessor for maintenance time run off the aircraft until the completion of the maintenance of the aircraft. Some of the master lease agreements do not require that the Company pay maintenance reserves so long as the Company's cash balance does not fall below a certain level. The Company is in full compliance with those requirements and does not anticipate having to pay reserves related to these master leases in the future.
	At lease inception and at each balance sheet date, the Company assesses whether the maintenance reserve payments required by the master lease agreements are substantively and contractually related to the maintenance of the leased asset. Maintenance reserve payments that are substantively and contractually related to the maintenance of the leased asset are accounted for as maintenance deposits to the extent they are expected to be recoverable and are reflected as prepaid maintenance deposits in the accompanying balance sheets. When it is not probable the Company will recover amounts currently on deposit with a lessor, such amounts are expensed as supplemental rent. As of December 31, 2013 and 2012, the Company had aircraft maintenance deposits of $220.7 million and $198.5 million, respectively, on its balance sheets of which $59.2 million and $76.1 million, respectively, are included within prepaid expenses and other current assets on its balance sheets. The Company has concluded that these prepaid maintenance deposits are probable of recovery primarily due to the rate differential between the maintenance reserve payments and the expected cost for the related next maintenance event that the reserves serve to collateralize.
	The Company’s master lease agreements also provide that most maintenance reserves held by the lessor at the expiration of the lease are nonrefundable to the Company and will be retained by the lessor. Consequently, any usage-based maintenance reserve payments after the last major maintenance event are not substantively related to the maintenance of the leased asset and therefore are accounted for as contingent rent. The Company accrues for contingent rent beginning when it becomes probable and reasonably estimable the Company will incur such nonrefundable maintenance reserve payments. The Company makes certain assumptions at the inception of the lease and at each balance sheet date to determine the recoverability of maintenance deposits. These assumptions are based on various factors such as the estimated time between the maintenance events, the date the aircraft is due to be returned to the lessor, and the number of flight hours the aircraft is estimated to be utilized before it is returned to the lessor. The Company expensed $1.9 million, $2.0 million and $1.5 million of paid maintenance reserves as supplemental rent during 2013, 2012 and 2011, respectively. Maintenance reserves held by lessors that are refundable to the Company at the expiration of the lease are accounted for as prepaid maintenance deposits on the balance sheet when they are paid.
	At December 31, 2013, the Company had its entire fleet of 54 aircraft and nine spare engines financed under operating leases with lease term expiration dates ranging from 2016 to 2025. Five of the leased aircraft have variable rent payments, which fluctuate based on changes in LIBOR (London Interbank Offered Rate). During the second quarter of 2013, the Company extended the operating leases on 14 of its Airbus A319 aircraft, which were previously set to expire in 2017 through 2019. The Company has the option to renew three leases for three-year periods with contractual notice required in the tenth year. Twenty-three of the aircraft leases and all of the engine leases were the result of sale and leaseback transactions. Deferred gains or losses from sale and leaseback transactions are amortized over the term of the lease as a reduction in rent or additional rent, respectively. Losses are deferred when the fair value of the aircraft or engine is higher than the price it was sold for, which is in substance, a prepayment of rent. A loss on disposal is recorded at the time of sale for the excess of the carrying amount over the fair value of the aircraft or engine. The costs of returning aircraft to lessors, or lease return conditions, are accounted for in a manner similar to the accounting for contingent rent. These costs are recognized over the remaining life of the lease as aircraft hours accumulate, beginning from the time when the Company determines it is probable such costs will be incurred and can generally be estimated. Such estimated costs exclude the costs of maintenance events that are covered by reserves on deposit with the relevant lessor, or routine maintenance costs that are recorded in maintenance expense.
	During 2013, the Company entered into sale and leaseback transactions with third-party aircraft lessors for the sale and leaseback of seven Airbus A320 aircraft that resulted in net deferred losses of $3.1 million, which are included in other long-term assets within the balance sheet. Deferred losses are amortized as 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 $36.7 million in pre-delivery deposits from Airbus during 2013. The refunded pre-delivery deposits have been disclosed in the statement of cash flows as investing activities within pre-delivery deposits, net of refunds. In addition, the Company entered into a sale and leaseback transaction with a third-party lessor for the sale and leaseback of one V2500 IAE International Aero Engines AG engine. Cash outflows related to the purchase of the engine have been disclosed in the statement of cash flows as investing activities within purchases of property and equipment and the cash inflows from the sale of the engine as financing activities within proceeds received on sale lease back transactions. All of the leases from these sale and leaseback transactions are 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. 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 QEC kits, classified as capital leases. Payments under the lease agreement are fixed for the three year term of the lease.
	The Company had two QEC kits classified as capital leases at December 31, 2013, compared to no capital leases at December 31, 2012. Amounts applicable to these QEC kits that are included in property and equipment were:
	(in thousands)	2013		2012
	Flight equipment	$	3,234	$	—
	Less: accumulated amortization	54		—
		$	3,180	$	—
	Future minimum lease payments under capital leases and noncancellable operating leases with initial or remaining terms in excess of one year at December 31, 2013 were as follows:
				Operating Leases
		Capital Leases		Aircraft and Spare Engine Leases		Property Facility Leases		Total Operating Leases
		(in thousands)
	2014	$	1,200	$	184,131	$	18,535	$	202,666
	2015	1,200		184,694		16,308		201,002
	2016	1,000		182,984		11,610		194,594
	2017	—		163,673		8,795		172,468
	2018	—		139,740		6,445		146,185
	2019 and thereafter	—		502,102		24,406		526,508
	Total minimum lease payments	$	3,400	$	1,357,324	$	86,099	$	1,443,423
	Less amount representing interest	366
	Present value of minimum lease payments	3,034
	Less current portion	1,400
	Long term portion	1,634

Financial_Instruments_and_Risk

Financial Instruments and Risk Management	12 Months Ended
	Dec. 31, 2013
Investments, All Other Investments [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 uses a variety of financial instruments to reduce its exposure to fluctuations in the price of jet fuel. 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 hedge 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 December 31, 2013, the Company held none of these instruments and, therefore, was not required 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 chose not to elect hedge accounting on any derivative instruments entered into during 2013, 2012 and 2011 and, as a result, changes in the fair value of these fuel hedge contracts are recorded each period in aircraft fuel expense.
	The following table summarizes the components of aircraft fuel expense for the years ended December 31, 2013, 2012 and 2011:
		Year Ended December 31,
		2013		2012		2011
		(in thousands)
	Into-plane fuel cost	$	542,523	$	471,542	$	392,278
	Settlement losses (gains)	8,958		175		(7,436		)
	Unrealized mark-to-market losses (gains)	265		46		3,204
	Aircraft fuel	$	551,746	$	471,763	$	388,046
	All realized gains and losses are reflected in the statements of cash flows in cash flow from operating activities.
	As of December 31, 2013, the Company had no outstanding fuel hedges in place. As of December 31, 2012, the Company had fuel hedges using U.S. Gulf Coast jet fuel options as the underlying commodity. As of December 31, 2012, the Company had agreements in place to protect 7.8 million gallons or approximately 5% of its 2013 fuel consumption at a weighted-average ceiling and floor price of $3.09 and $2.84 per gallon, respectively.

Defined_Contribution_401k_Plan

Defined Contribution 401(k) Plan	12 Months Ended
	Dec. 31, 2013
Postemployment Benefits [Abstract]	'
Defined Contribution 401(k) Plan	'
	Defined Contribution 401(k) Plan
	The Company sponsors three defined contribution 401(k) plans, Spirit Airlines, Inc. Employee Retirement Savings Plan (first plan), Spirit Airlines, Inc. Pilots’ Retirement Savings Plan (second plan) and Spirit Airlines, Inc. Puerto Rico Retirement Savings Plan (third plan). The first plan was adopted on February 1, 1994. Essentially, all employees that are not covered by the pilots’ collective bargaining agreement, who have at least one year of service, have worked at least 1,000 hours during the year and have attained the age of 21 may participate in this plan. The Company may make a Qualified Discretionary Contribution, as defined in the plan, or provide matching contributions to this plan. Effective July 1, 2007, the Company amended this plan to change the service requirement to 60 days and provided for matching contribution to the plan at 50% of the employee’s contribution up to a maximum employer contribution of 3% of the employee’s annual compensation.
	The second plan is for the Company’s pilots, and contained the same service requirements as the first plan and was amended effective July 1, 2007, to change the service requirements to 60 days and having attained the age of 21. The Company matches 100% of the pilot’s contribution, up to 8% of the individual pilot’s annual compensation. Both the first and the second plans are subject to the annual IRS elective deferral limit, which was $17,500 for 2013.
	The third plan is for all Company employees residing in Puerto Rico and was adopted on April 16, 2012. It contains the same amended service requirements as the first and second plans. For pilots participating in the Puerto Rico plan, the Company matches 100% of their contribution, up to 8% of the individual pilot's annual compensation, but subject to the annual Puerto Rico pre-tax elective deferral limit, which was $17,500 for 2013. For all other employees participating in the Puerto Rico plan, the Company provides for matching contribution to the plan at 50% of the employee's contribution up to a maximum employer contribution of 3% of the employee's annual compensation.
	Matching contributions made to all plans were $7.7 million , $6.6 million and $4.9 million in 2013, 2012 and 2011, respectively, and were included within salaries, wages and benefits in the accompanying statements of operations.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	Significant components of the provision for income taxes from continuing operations are as follows:
		For the Years Ended December 31,
		2013			2012			2011
		(in thousands)
	Current:
	Federal	$	86,437		$	32,656		$	1,866
	State and local	6,595			3,250			74
	Foreign	413			963			263
	Total current expense	93,445			36,869			2,203
	Deferred:
	Federal	11,658			27,870			42,148
	State and local	389			1,385			2,032
	Total deferred expense (benefit)	12,047			29,255			44,180
	Total income tax expense (benefit)	$	105,492		$	66,124		$	46,383
	The reconciliation of income tax expense computed at the federal statutory tax rates to income tax expense from continuing operations is as follows:
		For the Years Ended December 31,
		2013			2012			2011
		(in thousands)
	Expected provision at federal statutory tax rate	$	98,843		$	61,104		$	42,991
	State and foreign tax expense, net of federal benefit	4,695			3,726			2,255
	Interest and dividend on preferred stock	—			—			710
	Meals and entertainment	772			649			469
	Fines and penalties	134			84			(36		)
	Federal credits	(58		)	(182		)	(103		)
	Adjustment to deferred tax assets and liabilities	(54		)	(3		)	(3		)
	Other	1,160			746			100
	Total income tax expense (benefit)	$	105,492		$	66,124		$	46,383
	The Company accounts for income taxes using the asset and liability method. Deferred taxes are recorded based on differences between the financial statement basis and tax basis of assets and liabilities and available tax loss and credit carryforwards. At December 31, 2013 and 2012, the significant components of the Company's deferred taxes consisted of the following:
		December 31,
		2013			2012
		(in thousands)
	Deferred tax assets:
	Net operating loss	$	188		$	83
	Deferred loss	1,428			—
	Deferred revenue	6,241			5,829
	Nondeductible accruals	9,734			6,744
	Other	2,767			1,073
	Deferred tax assets	20,358			13,729
	Deferred tax liabilities:
	Capitalized interest	736			1,125
	Deferred gain	—			364
	Fuel hedging	—			97
	Accrued engine maintenance	45,911			29,497
	Property, plant and equipment	6,384			3,271
	Deferred tax liabilities	53,031			34,354
	Net deferred tax assets (liabilities)	$	(32,673	)	$	(20,625	)
	Deferred taxes included within:
	Assets:
	Other current assets	$	16,243		$	12,591
	Liabilities:
	Other long-term liabilities	$	48,916		$	33,216
	In assessing the realizability of the deferred tax assets, management considered whether it is more likely than not that some or all of the deferred tax assets would be realized. In evaluating the Company’s ability to utilize its deferred tax assets, it considered all available evidence, both positive and negative, in determining future taxable income on a jurisdiction by jurisdiction basis. Management does not believe that the realization of deferred tax assets is in jeopardy and thus a valuation allowance for 2013 will not be necessary.
	During 2013, the Company filed an amended 2009 income tax return in order to correct its net operating loss carryforward (NOL) as of December 31, 2009. See Note 18. The amendment of the 2009 tax return resulted in a decrease to the Company's NOL of $7.9 million as of December 31, 2009. In addition, during the preparation of its 2012 tax return, the Company uncovered certain adjustments relating to the NOL carryforward balance as of December 31, 2011. These adjustments resulted in an increase to the NOL carryforward of $3.7 million. The net decrease to the NOL carryforwards of $4.2 million changed the NOL carryforwards as of December 31, 2011 from $20.8 million, as previously reported in 2012 and 2011, to $16.6 million. At December 31, 2011, the Company had available for federal income tax purposes an alternative minimum tax (AMT) credit carryforward of $3.2 million and federal NOL carryforwards of $16.6 million which were fully utilized against federal taxable income during 2012. As of December 31, 2013 and 2012, the Company did not have any NOLs or AMT credits to utilize against federal taxable income. As of December 31, 2013, the Company had approximately $4.7 million of State NOLs which can be used to offset future state taxable income. State net operating losses begin to expire in 2017.
	Excess tax benefits are recognized in the financial statements upon actual realization of the related tax benefit which occurred in 2012 upon utilization of the remaining NOLs and AMT credit carryforwards during the year. During 2013, the Company recognized a windfall tax benefit of $1.9 million which was recorded as a reduction to income tax payable and a corresponding entry to additional paid in capital.
	During 2013, the Company recorded a foreign tax credit of $0.4 million against its 2013 federal income tax liability which was fully utilized during the year. Previously the Company deducted income taxes paid in foreign countries in arriving at federal taxable income.
	On September 13, 2013, the United States Treasury and Internal Revenue Service issued final tangible personal property regulations that broadly apply to amounts paid to acquire, produce or improve tangible property, as well as dispositions of such property. In review of these regulations, the Company has concluded that there is no material impact on its financial position, results of operations or cash flows.
	On January 25, 2012, the Company experienced a subsequent ownership change under the principles of IRC §382, as a result of the secondary offering outlined in more detail in Note 3. Although the Company was subject to the limitations of IRC §382 on the utilization of its NOL and the tax credit carryforwards in 2012, the limitation was sufficiently in excess of the tax attribute carryforwards as not to prohibit complete utilization during the year.
	The Company accrues interest related to unrecognized tax benefits in its provision for income taxes, and any associated penalties are recorded in selling, general and administrative expenses.
	The Company files its tax returns as prescribed by the tax laws of the jurisdictions in which it operates. The Company's tax years from 2006 through 2012 are still subject to examination in the United States due to net operating loss carryovers generated in such years. Various state and foreign jurisdiction tax years remain open to examination and the Company was under examination in certain jurisdictions during 2012, and the outcome of these audits were immaterial to the financial statements. The Company believes that the effect of any additional assessment(s) will be immaterial to its financial statements.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
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. On June 20, 2013, the Company entered into an amendment to the Airbus A320 Family Purchase Agreement, by and between the Company and Airbus S.A.A., dated May 5, 2004 (Airbus Amendment) for the order of an additional 20 Airbus A321 aircraft. These aircraft are in addition to the 92 aircraft not yet delivered under Spirit's existing order with Airbus. In addition, the Company is committed to take delivery of an additional five aircraft directly from a third-party lessor. During the year, the Company converted ten Airbus A320 orders to Airbus A321 orders and converted five Airbus A321 orders to Airbus A321neo orders. On October 1, 2013, the Company entered into agreements with International Aero Engines AG (IAE) and Pratt & Whitney (collectively, the IAE & P&W Agreement) for the provision and servicing of engines to power its fleet of Airbus A320 family aircraft.
	As of December 31, 2013, the Company's aircraft orders consisted of the following:
		Airbus				Third-Party Lessor
		A320	A320NEO	A321	A321NEO	A320NEO	Total
	2014	11					11
	2015	11		2		1	14
	2016	5		8		4	17
	2017	10		10			20
	2018		6	5			11
	2019		8		5		13
	2020		13				13
	2021		18				18
		37	45	25	5	5	117
	The Company also has six spare engine orders for V2500 SelectOne engines with IAE and nine spare engine orders for PurePower PW 1100G-JM engines with Pratt & Whitney. Spare engines are scheduled for delivery from 2014 through 2024. Purchase commitments for these aircraft and engines, including estimated amounts for contractual price escalations and pre-delivery payments, will be approximately $559.3 million in 2014, $619.1 million in 2015, $633.1 million in 2016, $804.5 million in 2017, $543.1 million in 2018 and $2,197.1 million in 2019 and beyond. The Company has secured financing commitments with third parties for seven aircraft deliveries from Airbus, scheduled for delivery in 2014 and for the five aircraft to be leased directly from a third party. The Company does not have financing commitments in place for the remaining 105 Airbus firm aircraft orders scheduled for delivery between 2014 and 2021.
	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.
	Employees
	The Company has three union-represented employee groups that together represent approximately 59% of all employees at December 31, 2013 and 54% of all employees at December 31, 2012. The table below sets forth the Company's employee groups and status of the collective bargaining agreements as of December 31, 2013.
	Employee Groups	Representative	Amendable Date	Percentage of Workforce
	Pilots	Air Line Pilots Association, International (ALPA)	August 2015	24%
	Flight Attendants	Association of Flight Attendants (AFA-CWA)	Aug-07	34%
	Dispatchers	Transport Workers Union (TWU)	Aug-18	1%
	In December 2013, with the help of the National Mediation Board (NMB), the Company 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 February 7, 2014, the Company was notified that the flight attendants voted to not ratify the tentative agreement. The Company will continue to work together with the AFA and the NMB with a goal of reaching a mutually beneficial agreement.
	The Company is self-insured for health care claims, subject to a stop-loss policy, 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 $2.1 million and $1.9 million, for health care claims as of December 31, 2013, and 2012, respectively.
	Other
	The Company is contractually obligated to pay the following minimum guaranteed payments to the provider of its reservation system as of December 31, 2013: $3.9 million in 2014, $3.9 million in 2015, $3.9 million in 2016, $3.9 million in 2017, $2.6 million in 2018 and $0.0 million in 2019 and thereafter.
	The Company entered into a Tax Receivable Agreement (TRA) with the Company's Pre-IPO Stockholders (as defined in the TRA) that became effective immediately prior to the consummation of the IPO. In accordance with the TRA, the Company paid $27.2 million, including $0.3 million of applicable interest, in the second quarter of 2012. As of December 31, 2013, the Company has $5.6 million accrued related to the TRA and $0.2 million of applicable interest. See Note 18.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2013
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 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	$	—		$	—	$	—	$	—
		Fair Value Measurements as of December 31, 2012
		Total			Level		Level		Level
					1		2		3
		(in millions)
	Cash and cash equivalents	$	416.8		$	416.8	$	—	$	—
	Jet fuel options	0.3			—		—		0.3
	Total assets	$	417.1		$	416.8	$	—	$	0.3
	Total liabilities	$	—		$	—	$	—	$	—
	Cash and cash equivalents at December 31, 2013 and December 31, 2012 are comprised of liquid money market funds and cash. The Company maintains cash with various high-quality financial institutions. The company had no outstanding derivatives as of December 31, 2013. The Company had no transfers of assets or liabilities between any of the above levels during the years ended December 31, 2013 and 2012.
	The Company did not elect hedge accounting on any of the derivative instruments, and as a result, changes in the fair values of these fuel hedge contracts are recorded each period in fuel expense. Fair values of the instruments are 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. The Company offsets fair value amounts recognized for derivative instruments executed with the same counterparty under a master netting arrangement. 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.
	Due to the fact that certain inputs utilized to determine the fair value of jet fuel options are unobservable (principally implied volatility), the Company categorizes these derivatives as Level 3. Implied volatility of a jet fuel option is the volatility of the price of the underlying commodity that is implied by the market price of the option based on an option pricing model. Thus, it is the volatility that, when used in a particular pricing model, yields a theoretical value for the option equal to the current market price of that option. Implied volatility, a forward-looking measure, differs from historical volatility because the latter is calculated from known past returns. At each balance sheet date, the Company substantiates and adjusts unobservable inputs. The Company routinely assesses the valuation model's sensitivity to changes in implied volatility. Based on the Company's assessment of the valuation model's sensitivity to changes in implied volatility, it noted that holding other inputs constant, a significant increase (decrease) in implied volatility would result in a significantly higher (lower) determination of fair value measurement for the Company's aircraft fuel derivatives.
	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 Finance Committee who approve all derivative transactions. 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 Options
		(in millions)
	Balance at January 1, 2011	$	3.5
	Total realized or unrealized gains (losses) included in earnings, net	4.2
	Settlements, net	(7.4		)
	Balance at December 31, 2011	0.3
	Total realized or unrealized gains (losses) included in earnings, net	(0.2		)
	Settlements, net	0.2
	Balance at December 31, 2012	0.3
	Total realized or unrealized gains (losses) included in earnings, net	0.1
	Settlements, net	(0.4		)
	Balance at December 31, 2013	$	—
	The Company records the fair value adjustment of its aircraft fuel derivatives in the accompanying statement of operations within aircraft fuel and on the balance sheet within prepaid expenses and 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.

Operating_Segments_and_Related

Operating Segments and Related Disclosures	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Operating Segments and Related Disclosures	'
	Operating Segments and Related Disclosures
	The Company is managed as a single business unit that provides air transportation for passengers. Operating revenues by geographic region as defined by the Department of Transportation (DOT) area are summarized below:
		2013		2012		2011
		(in millions)
	DOT—domestic	$	1,467.50	$	1,135.10	$	900.1
	DOT—Latin America	186.9		183.3		171.1
	Total	$	1,654.40	$	1,318.40	$	1,071.20
	During 2013, 2012 and 2011, no revenue from any one foreign country represented greater than 4% of the Company’s total passenger revenue. The Company attributes operating revenues by geographic region based upon the origin and destination of each passenger flight segment. The Company’s tangible assets consist primarily of flight equipment, which are mobile across geographic markets and, therefore, have not been allocated.

Initial_Public_Offering_and_Ta

Initial Public Offering and Tax Receivable Agreement	12 Months Ended
	Dec. 31, 2013
Tax Receivable Agreement [Abstract]	'
Initial Public Offering and Tax Receivable Agreement	'
	Initial Public Offering and Tax Receivable Agreement
	On June 1, 2011, the Company raised $187.2 million of gross proceeds from an initial public offering of 15,600,000 shares of its common stock at a price of $12.00 per share. The resulting proceeds to the Company were approximately $176.9 million, after deducting underwriter commissions. The Company retained $150.0 million of the net proceeds, after paying $20.6 million of debt, $0.5 million to pay three unaffiliated holders of its subordinated notes and $5.9 million in direct costs of the offering. In accordance with a Recapitalization Agreement, all of the principal and accrued and unpaid interest on outstanding notes, to the extent not paid, totaling $279.2 million, as well as all of the Class A and B preferred stock outstanding immediately prior to the offering along with accrued and unpaid dividends totaling $81.7 million, were exchanged for 30,079,420 shares of common stock at a share price of $12.00 per share. Each share of Class B Common Stock was exchanged for one share of common stock. In addition, interest expense was reduced by $0.4 million due to a write off of the unamortized portion of prepaid loan fees and deferred interest.
	In connection with the IPO, the Company entered into the 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 it 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 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 (as defined in the TRA) 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 will depend 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 will continue until the first to occur (a) the full payment of all amounts required under the agreement with respect to utilization or expiration of all of 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. Stockholder Representatives are defined as Indigo Pacific Partners, LLC and OCM FIE, LLC, representing the two largest ownership interest 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 have the right to employ the TRA's reconciliation procedures. If the Tax Benefit Schedule is accepted, the Company has five days after acceptance to make payments to the Pre-IPO stockholders. 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. During 2012, management adjusted for an immaterial error in the original estimate of the liability. This adjustment reduced the liability with an offset to additional paid in capital.
	During 2013, the Company filed an amended 2009 income tax return in order to correct its NOL carry forward as of December 31, 2009. See Note 14. As a result, the Company's NOL carry forward as of March 31, 2011 was consequently reduced by $7.8 million, which corresponds to a reduction in the estimated TRA benefit of $2.4 million with an offset to additional paid in capital. On September 13, 2013, the Company filed its 2012 federal income tax return, and on October 14, 2013, the Company submitted a 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. As of December 31, 2013, the Company estimated the TRA liability to be $5.6 million. The Company and the Stockholder Representatives are in discussions attempting to resolve the objection related to the Tax Benefit Schedule and have not employed the TRA's reconciliation procedures.

Quarterly_Financial_Data_Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Quarterly Financial Data (Unaudited)	'
	Quarterly Financial Data (Unaudited)
	Quarterly results of operations for the year ended December 31, 2013 are summarized below:
		Three Months Ended
		31-Mar		30-Jun		30-Sep		31-Dec
		(in thousands, except per share amounts)
	2013
	Operating revenue	$	370,437	$	407,339	$	456,625	$	419,984
	Operating income	49,669		66,758		97,804		68,061
	Net income	30,554		42,068		61,103		43,193
	Basic earnings per share	0.42		0.58		0.84		0.59
	Diluted earnings per share	0.42		0.58		0.84		0.59
	2012
	Operating revenue	$	301,495	$	346,308	$	342,317	$	328,268
	Operating income	37,244		55,132		49,681		31,933
	Net income	23,419		34,591		30,884		19,566
	Basic earnings per share	0.32		0.48		0.43		0.27
	Diluted earnings per share	0.32		0.48		0.43		0.27

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	Spirit Airlines, Inc. (Spirit or the Company) headquartered in Miramar, Florida, is an ultra low-cost, low-fare airline that provides affordable travel opportunities principally throughout the domestic United States, the Caribbean and Latin America. The Company manages operations on a system-wide basis due to the interdependence of its route structure in the various markets served. As only one service is offered (i.e., air transportation), management has concluded there is only one reportable segment.
	Certain prior period amounts have been reclassified to conform to the current year's presentation.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with generally accepted accounting principles in the United States of America requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from these estimates.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	The Company considers all highly liquid investments with maturities of less than three months at the date of acquisition to be cash equivalents. Investments included in this category primarily consist of money market funds.
Accounts Receivable	'
	Accounts Receivable
	Accounts receivable primarily consist of amounts due from credit card processors associated with the sales of tickets and amounts due from counterparties associated with fuel derivative instruments which have settled. The Company records an allowance for doubtful accounts for amounts not expected to be collected. The Company estimates the allowance based on historical write offs and chargebacks as well as aging trends. The allowance for doubtful accounts was immaterial as of December 31, 2013, 2012 and 2011.
	In addition, the provision for doubtful accounts and write-offs for 2013, 2012 and 2011 were each immaterial.
Property and Equipment	'
	Property and Equipment
	Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation of operating property and equipment is computed using the straight-line method applied to each unit of property, except on flight equipment (major rotable parts, avionics and assemblies), which are depreciated on a group basis over the average life of the applicable equipment. Property under capital leases and related obligations are initially recorded at an amount equal to the present value of future minimum lease payments computed using the Company's incremental borrowing rate or, when known, the interest rate implicit in the lease. Amortization of property under capital leases is on a straight-line basis over the lease term and is included in depreciation and amortization expense. During 2012, the Company wrote off approximately $15.3 million in fully depreciated and out-of-service assets and recorded a corresponding entry to accumulated depreciation.
	The depreciable lives used for the principal depreciable asset classifications are:
		Estimated Useful Life
	Spare rotables and flight assemblies	Lesser of the useful life of equipment or average remaining fleet life
	Other equipment and vehicles	5 to 7 years
	Internal use software	3 to 10 years
	Capital lease	Lease term
	All aircraft and spare engines are financed through operating leases with terms of 3 to 15 years for aircraft and 7 to 12 years for spare engines. Residual values for major spare rotable parts, avionics and assemblies are estimated to be 10%.
	The following table illustrates the components of depreciation and amortization expense:
		Year Ended December 31,
		2013			2012			2011
		(in thousands)
	Depreciation	$	8,340		$	6,156		$	5,186
	Amortization of heavy maintenance	23,607			9,100			2,574
	Total depreciation and amortization	$	31,947		$	15,256		$	7,760
	The Company capitalizes certain internal and external costs associated with the acquisition and development of internal-use software for new products, and enhancements to existing products, that have reached the application development stage and meet recoverability tests. Capitalized costs include external direct costs of materials and services utilized in developing or obtaining internal-use software, and labor cost for employees who are directly associated with, and devote time, to internal-use software projects. Capitalized computer software, included as a component of ground and other equipment in the accompanying balance sheets, net of accumulated depreciation, was $8.1 million and $7.8 million at December 31, 2013 and 2012, respectively.
	Amortization of capitalized software development costs is charged to depreciation on a straight-line method basis. Amortization of capitalized software development costs was $3.7 million, $3.2 million and $2.0 million for the years ended 2013, 2012 and 2011, respectively. The Company placed in service internal-use software of $7.0 million, $2.3 million and $3.3 million, during the years ended 2013, 2012 and 2011, respectively.
Measurement of Asset Impairments	'
	Measurement of Asset Impairments
	The Company records impairment charges on long-lived assets used in operations when events and circumstances indicate that the assets may be impaired, the undiscounted cash flows estimated to be generated by those assets are less than the carrying amount of those assets, and the net book value of the assets exceeds their estimated fair value. In making these determinations, the Company uses certain assumptions, including, but not limited to: (i) estimated fair value of the assets; and (ii) estimated, undiscounted future cash flows expected to be generated by these assets, which are based on additional assumptions such as asset utilization, length of service the asset will be used in the Company’s operations, and estimated salvage values.
Capitalized Interest	'
	Capitalized Interest
	Capitalized interest represents interest cost incurred during the acquisition period of an aircraft which theoretically could have been avoided had the Company not made purchase delivery deposits (PDPs) for that aircraft. These amounts are capitalized as part of the cost of the aircraft upon delivery. Capitalization of interest ceases when the asset is ready for service.
Passenger Revenue Recognition	'
	Passenger Revenue Recognition
	Tickets sold are initially deferred as “air traffic liability.” Passenger revenue is recognized at time of departure when transportation is provided. A nonrefundable ticket expires at the date of scheduled travel and is recognized as revenue at the date of scheduled travel.
	Customers may elect to change their itinerary prior to the date of departure. A service charge is assessed and recognized on the date the change is initiated and is deducted from the face value of the original purchase price of the ticket, and the original ticket becomes invalid. The amount remaining after deducting the service charge is called a credit shell which expires 60 days from the date the credit shell is created and can be used towards the purchase of a new ticket and the Company’s other service offerings. The amount of credits expected to expire is recognized as revenue upon issuance of the credit and is estimated based on historical experience. Estimating the amount of credits that will go unused involves some level of subjectivity and judgment.
	The Company is also required to collect certain taxes and fees from customers on behalf of government agencies and airports and remit these back to the applicable governmental entity or airport on a periodic basis. These taxes and fees include U.S. federal transportation taxes, federal security charges, airport passenger facility charges and foreign arrival and departure taxes. These items are collected from customers at the time they purchase their tickets, but are not included in passenger revenue. The Company records a liability upon collection from the customer and relieves the liability when payments are remitted to the applicable governmental agency or airport.
Frequent Flier Program	'
	Frequent Flier Program
	Flown Miles. The Company records a liability for mileage credits earned by passengers under its FREE SPIRIT program, including mileage credits for members with an insufficient number of mileage credits to earn an award, based on the estimated incremental cost of providing free travel for credits that are expected to be redeemed. Incremental costs include fuel, insurance, security, ticketing and facility charges reduced by an estimate of fees required to be paid by the passenger when redeeming the award.
	Affinity Card Program. Under the Company's affinity card program, funds received for the marketing of a co-branded Spirit credit card and delivery of award miles are accounted for as a mulitple-deliverable arrangement. At the inception of the arrangement, the Company evaluated all deliverables in the arrangement to determine whether they represent separate units of accounting using the criteria as set forth in ASU No. 2009-13. The Company determined the arrangement had three separate units of accounting: (i) travel miles to be awarded, (ii) licensing of brand and access to member lists and (iii) advertising and marketing efforts. Under ASU No. 2009-13, arrangement consideration was allocated based on relative selling price. At inception of the arrangement, the Company established the relative selling price for all deliverables that qualified for separation. The manner in which the selling price was established was based on a hierarchy of evidence that the Company considered. Total arrangement consideration was then allocated to each deliverable on the basis of the deliverable’s relative selling price. In considering the hierarchy of evidence under ASU No. 2009-13, the Company first determined whether vendor specific objective evidence of selling price or third-party evidence of selling price existed. It was determined by the Company that neither vendor specific objective evidence of selling price nor third-party evidence existed due to the uniqueness of the Company’s program. As such, the Company developed its best estimate of the selling price for all deliverables. For the award miles, the Company considered a number of entity-specific factors when developing the best estimate of the selling price including the number of miles needed to redeem an award, average fare of comparable segments, breakage, restrictions and other charges. For licensing of brand and access to member lists, the Company considered both market-specific factors and entity-specific factors including general profit margins realized in the marketplace/industry, brand power, market royalty rates and size of customer base. For the advertising element, the Company considered market-specific factors and entity-specific factors, including the Company’s internal costs (and fluctuations of costs) of providing services, volume of marketing efforts and overall advertising plan. Consideration allocated based on the relative selling price to both brand licensing and advertising elements is recognized as revenue when earned and recorded in non-ticket revenue. Consideration allocated to award miles is deferred and recognized ratably as passenger revenue over the estimated period the transportation is expected to be provided which is estimated at 16 months. The Company used entity-specific assumptions coupled with the various judgments necessary to determine the selling price of a deliverable in accordance with the required selling price hierarchy. Changes in these assumptions could result in changes in the estimated selling prices. Determining the frequency to reassess selling price for individual deliverables requires significant judgment. As of December 31, 2013, there have been no changes in either the selling price or the method or assumptions used to determine selling price for any of the identified units of accounting that would have a significant effect on the allocation of consideration.
	The following table illustrates total cash proceeds received from the sale of mileage credits and the portion of such proceeds recognized in revenue immediately as marketing component:
		Cash proceeds from sale of miles to non-airline third parties			Portion of proceeds recognized immediately as marketing component
	Year Ended	(in thousands)
	December 31, 2013	$	28,496		$	23,124
	December 31, 2012	24,938			20,998
	December 31, 2011	20,954			16,580
	The total liability for future FREE SPIRIT award redemptions and unrecognized revenue from the sale of mileage credits was $2.6 million and $2.4 million at December 31, 2013 and 2012, respectively. These balances are recorded as a component of air traffic liability in the accompanying balance sheets.
Non-ticket Revenue Recognition	'
	Non-ticket Revenue Recognition
	Non-ticket revenues are generated from air travel-related services for baggage, bookings through the Company’s call center or third-party vendors, advance seat selection, itinerary changes and loyalty programs. Non-ticket revenues also consist of services not directly related to providing transportation such as the FREE SPIRIT affinity credit card program, $9 Fare Club and the sale of advertising to third parties on Spirit’s website and on board aircraft.
	The following table summarizes the primary components of non-ticket revenue and the revenue recognition method utilized for each service or product:
			Year Ended December 31,
	Non-ticket revenue	Recognition method	2013			2012			2011
			(in thousands)
	Baggage	Time of departure	$	275,958		$	217,536		$	168,290
	Passenger usage fee	Time of departure	188,911			149,577			71,757
	Advance seat selection	Time of departure	59,241			48,956			42,112
	Service charges for changes and cancellations	When itinerary is changed	32,546			27,762			25,927
	Other		111,711			91,765			73,450
	Non-ticket revenue		$	668,367		$	535,596		$	381,536
	Charges for services recognized at time of departure are initially recorded as a liability until time of departure. The passenger usage fee is charged for tickets sold through the Company’s primary sales distribution channels, to cover the Company’s distribution costs. The primary sales distribution channels for which passenger usage fees are charged include sales through the Company’s website, sales through the third-party provided call center and sales through travel agents; the Company does not charge a passenger usage fee for sales made at its airport ticket counters. Other non-ticket revenues include revenues from other air related charges as well as non-air related charges. Other air related charges include optional services and products provided to passengers such as on-board products, travel insurance and use of the Company’s call center or travel agents, among others. Non-air related charges primarily consist of revenues from advertising on the Company’s aircraft and website, the Company’s $9 Fare Club subscription-based membership program and the Company’s FREE SPIRIT affinity credit card program.
Airframe and Engine Maintenance	'
	Airframe and Engine Maintenance
	The Company accounts for heavy maintenance and major overhaul and repair under the deferral method whereby the cost of heavy maintenance and major overhaul and repair is deferred and amortized until the earlier of the end of the remaining lease term or until the next scheduled heavy maintenance event.
	Amortization of heavy maintenance and major overhaul costs is charged to depreciation and amortization expense and was $23.6 million, $9.1 million and $2.6 million for the years ended 2013, 2012 and 2011, respectively. During the years ended 2013, 2012 and 2011, the Company deferred $70.8 million, $61.6 million and $22.1 million, respectively, of costs for heavy maintenance. At December 31, 2013 and 2012, the Company had deferred heavy maintenance balance of $165.3 million and $94.5 million, and accumulated heavy maintenance amortization of $40.0 million and $14.0 million, respectively.
	On October 15, 2013, the Company had an aircraft experience 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. The Company anticipates it will recover insurance proceeds to cover the expenses related to this incident and therefore it has expensed the insurance deductible of approximately $0.8 million recorded within maintenance, materials and repairs expense.
	The Company outsources certain routine, non-heavy maintenance functions under contracts that require payment on a utilization basis, such as flight hours. Costs incurred for maintenance and repair under flight hour maintenance contracts, where labor and materials price risks have been transferred to the service provider, are expensed based on contractual payment terms. All other costs for routine maintenance of the airframes and engines are charged to expense as performed.
	The table below summarizes the extent to which the Company’s maintenance costs are rate capped due to flight hour maintenance contracts:
		Year Ended December 31,
		2013			2012			2011
		(in thousands)
	Flight hour-based maintenance expense	$	30,322		$	25,748		$	21,974
	Non-flight hour-based maintenance expense	29,821			23,712			12,043
	Total maintenance, materials and repairs	$	60,143		$	49,460		$	34,017
Leased Aircraft Return Costs	'
	Leased Aircraft Return Costs
	Costs associated with returning leased aircraft are accrued when it is probable that a cash payment will be made and that amount is reasonably estimable. Leased aircraft return costs are recorded as a component of aircraft rent and characterized as supplemental rent. Any accrual is based on time remaining on the lease, planned aircraft usages and the provisions included in the lease agreement, although the actual amount due to any lessor upon return will not be known with certainty until lease termination.
Aircraft Fuel	'
	Aircraft Fuel
	Aircraft fuel expense includes jet fuel and associated “into-plane” costs, taxes, oil and all gains and losses associated with fuel hedge contracts.
Derivative Instruments	'
	Derivative Instruments
	The Company accounts for derivative financial instruments at fair value and recognizes them in the balance sheet in prepaid expenses and other current assets or other current liabilities. For derivatives designated as cash flow hedges, changes in fair value of the derivative are generally reported in other comprehensive income and are subsequently reclassified into earnings when the hedged item affects earnings. For the years ended 2013, 2012 and 2011, the Company did not hold derivative instruments that qualified as cash flow hedges for accounting purposes. As a result, changes in the fair value of such derivative contracts were recorded within aircraft fuel expense in the accompanying statements of operations. These amounts include both realized gains and losses and mark-to-market adjustments of the fair value of unsettled derivative instruments at the end of each period.
Advertising	'
	Advertising
	The Company expenses advertising and the production costs of advertising as incurred. Marketing and advertising expenses were $2.1 million, $2.4 million and $2.5 million for the years ended 2013, 2012 and 2011, respectively.
Income Taxes	'
	Income Taxes
	The Company accounts for income taxes using the liability method. The Company records a valuation allowance to reduce the deferred tax assets reported if, based on the weight of the evidence, it is more likely than not that some portion or all of the deferred tax assets will be not realized.
Interest Expense	'
	Interest Expense
	Related-party interest expense incurred during 2013, 2012 and 2011 was $0.0 million, $0.0 million and $21.0 million, respectively, and consisted primarily of paid-in-kind interest on tranche notes due to related parties, and preferred stock dividends due to related parties. Non-related party interest expense during 2013, 2012 and 2011 was $0.2 million, $1.4 million and $3.8 million, respectively.
Stock-Based Compensation	'
	Stock-Based Compensation
	The Company recognizes cost of employee services received in exchange for awards of equity instruments based on the fair value of each instrument at the date of grant. Compensation expense is recognized on a straight-line basis over the period during which an employee is required to provide service in exchange for an award. The Company has issued and outstanding restricted stock awards, stock option awards and performance share awards. Restricted stock awards are valued at the fair value of the shares on the date of grant. To the extent a market price was not available, the fair value of stock awards was estimated using a discounted cash flow analysis based on management’s estimates of revenue, driven by assumed market growth rates and estimated costs as well as appropriate discount rates. These estimates are consistent with the plans and estimates that management uses to manage the Company’s business. The fair value of share option awards is estimated on the date of grant using the Black-Scholes valuation model. The fair value of performance share awards is estimated through the use of a Monte Carlo simulation model. See Note 8 for additional information.
Concentrations of Risk	'
	Concentrations of Risk
	The Company’s business has been, and may continue to be, adversely affected by increases in the price of aircraft fuel, the volatility of the price of aircraft fuel, or both. Aircraft fuel was the Company’s single largest expenditure representing approximately 40%, 41% and 42% of total operating expenses in 2013, 2012 and 2011, respectively.
	The Company’s operations are largely concentrated in the southeast United States with Fort Lauderdale being the highest volume fueling point in the system. Gulf Coast Jet indexed fuel is the basis for a substantial majority of the Company’s fuel consumption. Any disruption to the oil production or refinery capacity in the Gulf Coast, as a result of weather or any other disaster, or disruptions in supply of jet fuel, dramatic escalations in the costs of jet fuel and/or the failure of fuel providers to perform under fuel arrangements for other reasons could have a material adverse effect on the Company’s financial condition and results of operations.
	The Company’s operations will continue to be vulnerable to weather conditions (including hurricane season or snow and severe winter weather), which could disrupt service, create air traffic control problems, decrease revenue and increase costs.
	Due to the relatively small size of the fleet and high utilization rate, the unavailability of one or more aircraft and resulting reduced capacity could have a material adverse effect on the Company’s business, results of operations and financial condition.
	The Company has three union-represented employee groups that together represent approximately 59% and 54% of all employees at December 31, 2013 and 2012, respectively. A strike or other significant labor dispute with the Company’s unionized employees is likely to adversely affect the Company’s ability to conduct business. Additional disclosures are included in Note 15.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Depreciable lives used for the principal depreciable asset classifications	'
	The depreciable lives used for the principal depreciable asset classifications are:
		Estimated Useful Life
	Spare rotables and flight assemblies	Lesser of the useful life of equipment or average remaining fleet life
	Other equipment and vehicles	5 to 7 years
	Internal use software	3 to 10 years
	Capital lease	Lease term
Components of depreciation and amortization expense	'
	The following table illustrates the components of depreciation and amortization expense:
		Year Ended December 31,
		2013			2012			2011
		(in thousands)
	Depreciation	$	8,340		$	6,156		$	5,186
	Amortization of heavy maintenance	23,607			9,100			2,574
	Total depreciation and amortization	$	31,947		$	15,256		$	7,760
Total cash proceeds received from the sale of mileage credit	'
	The following table illustrates total cash proceeds received from the sale of mileage credits and the portion of such proceeds recognized in revenue immediately as marketing component:
		Cash proceeds from sale of miles to non-airline third parties			Portion of proceeds recognized immediately as marketing component
	Year Ended	(in thousands)
	December 31, 2013	$	28,496		$	23,124
	December 31, 2012	24,938			20,998
	December 31, 2011	20,954			16,580
Primary components of non-ticket revenue and the revenue recognition method utilized for each service or product	'
	The following table summarizes the primary components of non-ticket revenue and the revenue recognition method utilized for each service or product:
			Year Ended December 31,
	Non-ticket revenue	Recognition method	2013			2012			2011
			(in thousands)
	Baggage	Time of departure	$	275,958		$	217,536		$	168,290
	Passenger usage fee	Time of departure	188,911			149,577			71,757
	Advance seat selection	Time of departure	59,241			48,956			42,112
	Service charges for changes and cancellations	When itinerary is changed	32,546			27,762			25,927
	Other		111,711			91,765			73,450
	Non-ticket revenue		$	668,367		$	535,596		$	381,536
Aircraft maintenance expense	'
	The table below summarizes the extent to which the Company’s maintenance costs are rate capped due to flight hour maintenance contracts:
		Year Ended December 31,
		2013			2012			2011
		(in thousands)
	Flight hour-based maintenance expense	$	30,322		$	25,748		$	21,974
	Non-flight hour-based maintenance expense	29,821			23,712			12,043
	Total maintenance, materials and repairs	$	60,143		$	49,460		$	34,017

Accrued_Liabilities_Tables

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2013
Payables and Accruals [Abstract]	'
Accrued liabilities included in other current liabilities	'
	Accrued liabilities included in other current liabilities as of December 31, 2013 and 2012 consist of the following:
		As of December 31,
		2013		2012
		(in thousands)
	Aircraft maintenance	$	36,165	$	22,319
	Federal excise and other passenger taxes and fees payable	26,979		23,401
	Salaries and wages	26,174		21,057
	Airport expenses	17,109		16,024
	Fuel	13,819		11,219
	Aircraft and facility rent	7,993		8,020
	Tax receivable agreement	5,643		7,987
	Other	11,380		11,287
	Other current liabilities	$	145,262	$	121,314

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Summary of the status of the Company's restricted stock shares	'
	A summary of the status of the Company’s restricted stock shares (restricted stock awards and restricted stock unit awards) as of December 31, 2013 and changes during the year ended December 31, 2013 is presented below:
		Number of Shares			Weighted-Average
					Grant Date Fair Value ($)
	Outstanding at December 31, 2012	449,629			16.94
	Granted	151,202			27.7
	Vested	(168,514	)		13.19
	Forfeited	(96,269	)		19.28
	Outstanding at December 31, 2013	336,048			22.99
Summary of share option activity	'
	A summary of share option activity under the 2011 Plan as of December 31, 2013 and changes during the year ended December 31, 2013 is presented below:
		Number			Weighted-	Average	Aggregate
		of Options			Average	Remaining	Intrinsic
					Exercise	Contractual	Value
					Price ($)	Term	$0
						(Years)
	Outstanding at December 31, 2012	247,650			9.59	8	2,015
	Exercised	(92,400	)		9.22
	Forfeited or expired	(98,750	)		10.7
	Outstanding at December 31, 2013	56,500			8.26	6.7	2,099
	Exercisable at December 31, 2013	27,125			8.12	6.6	1,011
	Vested or Expected to Vest at December 31, 2013	56,260			8.25	6.7	2,090
Multiple input variables of performance share awards	'
	The grant date fair value of the performance share awards was determined through the use of a Monte Carlo simulation model, which utilizes multiple input variables that determine the probability of satisfying the market condition requirements applicable to each award as follows:
		Weighted-Average at Grant Date for Year Ended December 31, 2013		Weighted-Average at Grant Date for Year Ended December 31, 2012
	Expected volatility factor	0.41		0.39
	Risk free interest rate	0.33	%	0.44	%
	Expected term (in years)	2.65		2.72
	Expected dividend yield	—	%	—	%
Performance share award activity	'
	The following table summarizes the Company’s performance share awards for the year ended December 31, 2013:
		Number of Awards			Weighted-Average Fair Value at Grant Date ($)
	Outstanding at December 31, 2012	280,907			20.3
	Granted	126,147			28.09
	Vested	—			—
	Forfeited	(79,950	)		21.76
	Outstanding at December 31, 2013	327,104			22.94

Net_Income_per_Share_Tables

Net Income per Share (Tables)	12 Months Ended
	Dec. 31, 2013
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:
		Year Ended December 31,
		2013		2012		2011
		(in thousands, except per share amounts)
	Numerator:
	Net income	$	176,918	$	108,460	$	76,448
	Denominator:
	Weighted-average shares outstanding, basic	72,593		72,386		53,241
	Effect of dilutive stock awards	406		205		274
	Adjusted weighted-average shares outstanding, diluted	72,999		72,591		53,515
	Net Income per Share:
	Basic earnings per common share	$	2.44	$	1.5	$	1.44
	Diluted earnings per common share	$	2.42	$	1.49	$	1.43
	Anti-dilutive weighted-average shares	1		88		70

Leases_and_Prepaid_Maintenance1

Leases and Prepaid Maintenance Deposits (Tables)	12 Months Ended
	Dec. 31, 2013
Leases And Prepaid Maintenance Deposits [Abstract]	'
Schedule of capital leased assets	'
	Amounts applicable to these QEC kits that are included in property and equipment were:
	(in thousands)	2013		2012
	Flight equipment	$	3,234	$	—
	Less: accumulated amortization	54		—
		$	3,180	$	—
Future minimum lease payments under noncancelable capital and operating leases	'
	Future minimum lease payments under capital leases and noncancellable operating leases with initial or remaining terms in excess of one year at December 31, 2013 were as follows:
				Operating Leases
		Capital Leases		Aircraft and Spare Engine Leases		Property Facility Leases		Total Operating Leases
		(in thousands)
	2014	$	1,200	$	184,131	$	18,535	$	202,666
	2015	1,200		184,694		16,308		201,002
	2016	1,000		182,984		11,610		194,594
	2017	—		163,673		8,795		172,468
	2018	—		139,740		6,445		146,185
	2019 and thereafter	—		502,102		24,406		526,508
	Total minimum lease payments	$	3,400	$	1,357,324	$	86,099	$	1,443,423
	Less amount representing interest	366
	Present value of minimum lease payments	3,034
	Less current portion	1,400
	Long term portion	1,634

Financial_Instruments_and_Risk1

Financial Instruments and Risk Management (Tables)	12 Months Ended
	Dec. 31, 2013
Investments, All Other Investments [Abstract]	'
Components of aircraft fuel expense	'
	The following table summarizes the components of aircraft fuel expense for the years ended December 31, 2013, 2012 and 2011:
		Year Ended December 31,
		2013		2012		2011
		(in thousands)
	Into-plane fuel cost	$	542,523	$	471,542	$	392,278
	Settlement losses (gains)	8,958		175		(7,436		)
	Unrealized mark-to-market losses (gains)	265		46		3,204
	Aircraft fuel	$	551,746	$	471,763	$	388,046

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Significant components of the provision for income taxes from continuing operations	'
	Significant components of the provision for income taxes from continuing operations are as follows:
		For the Years Ended December 31,
		2013			2012			2011
		(in thousands)
	Current:
	Federal	$	86,437		$	32,656		$	1,866
	State and local	6,595			3,250			74
	Foreign	413			963			263
	Total current expense	93,445			36,869			2,203
	Deferred:
	Federal	11,658			27,870			42,148
	State and local	389			1,385			2,032
	Total deferred expense (benefit)	12,047			29,255			44,180
	Total income tax expense (benefit)	$	105,492		$	66,124		$	46,383
Reconciliation of income tax expense	'
	The reconciliation of income tax expense computed at the federal statutory tax rates to income tax expense from continuing operations is as follows:
		For the Years Ended December 31,
		2013			2012			2011
		(in thousands)
	Expected provision at federal statutory tax rate	$	98,843		$	61,104		$	42,991
	State and foreign tax expense, net of federal benefit	4,695			3,726			2,255
	Interest and dividend on preferred stock	—			—			710
	Meals and entertainment	772			649			469
	Fines and penalties	134			84			(36		)
	Federal credits	(58		)	(182		)	(103		)
	Adjustment to deferred tax assets and liabilities	(54		)	(3		)	(3		)
	Other	1,160			746			100
	Total income tax expense (benefit)	$	105,492		$	66,124		$	46,383
Deferred taxes	'
	The Company accounts for income taxes using the asset and liability method. Deferred taxes are recorded based on differences between the financial statement basis and tax basis of assets and liabilities and available tax loss and credit carryforwards. At December 31, 2013 and 2012, the significant components of the Company's deferred taxes consisted of the following:
		December 31,
		2013			2012
		(in thousands)
	Deferred tax assets:
	Net operating loss	$	188		$	83
	Deferred loss	1,428			—
	Deferred revenue	6,241			5,829
	Nondeductible accruals	9,734			6,744
	Other	2,767			1,073
	Deferred tax assets	20,358			13,729
	Deferred tax liabilities:
	Capitalized interest	736			1,125
	Deferred gain	—			364
	Fuel hedging	—			97
	Accrued engine maintenance	45,911			29,497
	Property, plant and equipment	6,384			3,271
	Deferred tax liabilities	53,031			34,354
	Net deferred tax assets (liabilities)	$	(32,673	)	$	(20,625	)
	Deferred taxes included within:
	Assets:
	Other current assets	$	16,243		$	12,591
	Liabilities:
	Other long-term liabilities	$	48,916		$	33,216

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Schedule of Future Operating Aircraft Leases	'
	As of December 31, 2013, the Company's aircraft orders consisted of the following:
		Airbus				Third-Party Lessor
		A320	A320NEO	A321	A321NEO	A320NEO	Total
	2014	11					11
	2015	11		2		1	14
	2016	5		8		4	17
	2017	10		10			20
	2018		6	5			11
	2019		8		5		13
	2020		13				13
	2021		18				18
		37	45	25	5	5	117
Number of employees, total | Unionized employees concentration risk	'
Concentration Risk [Line Items]	'
Schedules of Concentration of Risk, by Risk Factor	'
	The table below sets forth the Company's employee groups and status of the collective bargaining agreements as of December 31, 2013.
	Employee Groups	Representative	Amendable Date	Percentage of Workforce
	Pilots	Air Line Pilots Association, International (ALPA)	August 2015	24%
	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)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
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 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	$	—		$	—	$	—	$	—
		Fair Value Measurements as of December 31, 2012
		Total			Level		Level		Level
					1		2		3
		(in millions)
	Cash and cash equivalents	$	416.8		$	416.8	$	—	$	—
	Jet fuel options	0.3			—		—		0.3
	Total assets	$	417.1		$	416.8	$	—	$	0.3
	Total liabilities	$	—		$	—	$	—	$	—
Assets and liabilities measured at fair value on a recuring 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 Options
		(in millions)
	Balance at January 1, 2011	$	3.5
	Total realized or unrealized gains (losses) included in earnings, net	4.2
	Settlements, net	(7.4		)
	Balance at December 31, 2011	0.3
	Total realized or unrealized gains (losses) included in earnings, net	(0.2		)
	Settlements, net	0.2
	Balance at December 31, 2012	0.3
	Total realized or unrealized gains (losses) included in earnings, net	0.1
	Settlements, net	(0.4		)
	Balance at December 31, 2013	$	—

Operating_Segments_and_Related1

Operating Segments and Related Disclosures (Tables)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Operating revenues by geographic region	'
	Operating revenues by geographic region as defined by the Department of Transportation (DOT) area are summarized below:
		2013		2012		2011
		(in millions)
	DOT—domestic	$	1,467.50	$	1,135.10	$	900.1
	DOT—Latin America	186.9		183.3		171.1
	Total	$	1,654.40	$	1,318.40	$	1,071.20

Quarterly_Financial_Data_Unaud1

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Quarterly results of operations	'
	Quarterly results of operations for the year ended December 31, 2013 are summarized below:
		Three Months Ended
		31-Mar		30-Jun		30-Sep		31-Dec
		(in thousands, except per share amounts)
	2013
	Operating revenue	$	370,437	$	407,339	$	456,625	$	419,984
	Operating income	49,669		66,758		97,804		68,061
	Net income	30,554		42,068		61,103		43,193
	Basic earnings per share	0.42		0.58		0.84		0.59
	Diluted earnings per share	0.42		0.58		0.84		0.59
	2012
	Operating revenue	$	301,495	$	346,308	$	342,317	$	328,268
	Operating income	37,244		55,132		49,681		31,933
	Net income	23,419		34,591		30,884		19,566
	Basic earnings per share	0.32		0.48		0.43		0.27
	Diluted earnings per share	0.32		0.48		0.43		0.27

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Concentration Risk [Line Items]	'	'	'
Credit shell, term of expiration	'60 days	'	'
Amortization of heavy maintenance and major overhaul costs	$23,607,000	$9,100,000	$2,574,000
Deferred costs for heavy maintenance	70,800,000	61,600,000	22,100,000
Deferred heavy maintenance, gross	165,300,000	94,500,000	'
Accumulated heavy maintenance amortization	-40,000,000	-14,000,000	'
Marketing and advertising expenses	2,100,000	2,400,000	2,500,000
Related-party interest expense	0	0	21,000,000
Non-related party interest expense	200,000	1,400,000	3,800,000
Insurance Deductible	$800,000	'	'
Aircraft fuel expenditure concentration risk | Total operating expenses	'	'	'
Concentration Risk [Line Items]	'	'	'
Concentration of risk	40.00%	41.00%	42.00%
Unionized employees concentration risk | Number of employees, total	'	'	'
Concentration Risk [Line Items]	'	'	'
Concentration of risk	59.00%	54.00%	'
Union-represented employee groups	3	3	'

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Property and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]	'	'	'
Write-off of fully depreciated assets	'	$15,300,000	'
Depreciation, Depletion and Amortization, Nonproduction [Abstract]	'	'	'
Depreciation	8,340,000	6,156,000	5,186,000
Amortization of heavy maintenance	23,607,000	9,100,000	2,574,000
Total depreciation and amortization	31,947,000	15,256,000	7,760,000
Other equipment and vehicles | Minimum	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Depreciable lives used for the principal depreciable asset classifications	'5 years	'	'
Other equipment and vehicles | Maximum	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Depreciable lives used for the principal depreciable asset classifications	'7 years	'	'
Internally developed software	'	'	'
Depreciation, Depletion and Amortization, Nonproduction [Abstract]	'	'	'
Depreciation	3,700,000	3,200,000	2,000,000
Capitalized software development costs during the year	8,100,000	7,800,000	'
Capitalized computer software, placed in service internal-use software	$7,000,000	$2,300,000	$3,300,000
Internally developed software | Minimum	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Depreciable lives used for the principal depreciable asset classifications	'3 years	'	'
Internally developed software | Maximum	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Depreciable lives used for the principal depreciable asset classifications	'10 years	'	'
Aircraft | Minimum	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Operating leases, term	'3 years	'	'
Aircraft | Maximum	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Operating leases, term	'15 years	'	'
Spare engines | Minimum	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Operating leases, term	'7 years	'	'
Spare engines | Maximum	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Operating leases, term	'12 years	'	'
Major spare rotable parts, avionics, and assemblies	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Residual value, percentage	'	10.00%	'

Summary_of_Significant_Account5

Summary of Significant Accounting Policies - Frequent Flier Program (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2012
In Millions, unless otherwise specified			Transportation Component
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]	'	'	'
Affinity Card Program, deferred fair value of the transportation component, recognition period	'	'	'16 months
Liability for future FREE SPIRIT award redemptions and unrecognized revenue from the sale of mileage credits	$2.60	$2.40	'

Summary_of_Significant_Account6

Summary of Significant Accounting Policies - Cash Proceeds Received from the Sale of Mileage Credits (Details) (Marketing Component, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Marketing Component	'	'	'
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]	'	'	'
Cash proceeds from sale of miles to non-airline third parties	$28,496	$24,938	$20,954
Portion of proceeds recognized immediately as marketing component	$23,124	$20,998	$16,580

Summary_of_Significant_Account7

Summary of Significant Accounting Policies - Primary Components of Non-Ticket Revenue (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]	'	'	'
Non-ticket revenue	$668,367	$535,596	$381,536
Baggage	'	'	'
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]	'	'	'
Non-ticket revenue	275,958	217,536	168,290
Passenger usage fee	'	'	'
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]	'	'	'
Non-ticket revenue	188,911	149,577	71,757
Advance seat selection	'	'	'
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]	'	'	'
Non-ticket revenue	59,241	48,956	42,112
Change fees	'	'	'
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]	'	'	'
Non-ticket revenue	32,546	27,762	25,927
Other	'	'	'
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]	'	'	'
Non-ticket revenue	$111,711	$91,765	$73,450

Summary_of_Significant_Account8

Summary of Significant Accounting Policies - Maintenance Costs (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Aircraft Maintenance, Materials, and Repairs [Line Items]	'	'	'
Total maintenance expense	$60,143	$49,460	$34,017
Flight hour-based maintenance expense	'	'	'
Aircraft Maintenance, Materials, and Repairs [Line Items]	'	'	'
Total maintenance expense	30,322	25,748	21,974
Non-flight hour-based maintenance expense	'	'	'
Aircraft Maintenance, Materials, and Repairs [Line Items]	'	'	'
Total maintenance expense	$29,821	$23,712	$12,043

Special_Charges_and_Credits_De

Special Charges and Credits (Details) (USD $)

12 Months Ended

3 Months Ended

1 Months Ended

12 Months Ended

24 Months Ended

1 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Sep. 30, 2013

Sep. 30, 2012

Jan. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Jun. 30, 2011

Dec. 31, 2011

Sep. 30, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2011

Dec. 31, 2011

debtors

Third Quarter 2013 Secondary Offering [Member]

Third Quarter Two Thousand Twelve Secondary Offering [Member]

January 25, 2012 Secondary Offering [Member]

January 25, 2012 Secondary Offering [Member]

January 25, 2012 Secondary Offering [Member]

Initial Public Offering

Initial Public Offering

Slot Transaction [Member]

Slot Transaction [Member]

Ronald Reagan National Airport (DCA) Exit Plan [Member]

Indigo Partners, Llc Professional Services Agreement Termination [Member]

Repayments to Unaffiliated Debt Holders

aircraft_slot

Initial Public Offering

Initial Public Offering

Restructuring Cost and Reserve [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of permanent air carrier slots transferred

'

'

'

'

'

'

'

'

'

'

'

4

'

'

'

Proceeds from sale of slots

$0

$9,060,000

$0

'

'

'

'

'

'

'

'

$9,100,000

'

'

'

Business Exit Costs

'

'

'

'

'

'

'

'

'

'

'

'

100,000

'

'

Write-off of Accrued Business Exit Costs

'

'

'

'

'

'

'

'

'

'

'

'

200,000

'

'

Gain (loss) on slot sale

0

9,060,000

0

'

'

'

'

'

'

'

9,100,000

'

'

'

'

Shares sold by certain stockholders in secondary offering (in shares)

'

'

'

12,070,920

9,394,927

12,650,000

'

'

'

'

'

'

'

'

'

Payments of stock issuance costs

'

'

'

300,000

700,000

'

500,000

1,300,000

'

'

'

'

'

'

'

Common stock, shares held, by certain stockholders post secondary offering

'

'

'

0

0

'

'

'

'

'

'

'

'

'

'

Stock issuance cost reimbursements

'

'

'

'

'

'

600,000

'

'

'

'

'

'

'

'

Shares issued in public offering (in shares)

'

'

'

'

'

'

'

'

15,600,000

'

'

'

'

'

'

Incurred costs

'

'

'

'

'

'

'

'

'

$2,300,000

'

'

'

$1,800,000

$500,000

Number of unaffiliated debt holders paid with IPO proceeds (in debtors)

'

'

3

'

'

'

'

'

'

'

'

'

'

'

'

Letters_of_Credit_Details

Letters of Credit (Details) (Standby letter of credit facility, USD $)	Dec. 31, 2013	Dec. 31, 2012
Standby letter of credit facility	'	'
Line of Credit Facility [Line Items]	'	'
Posted letters of credit	$200,000	$200,000
Unsecured standby letter of credit facility, maximum borrowing capacity	25,100,000	'
Unsecured standby letter of credit facility, amount outstanding	$10,400,000	'

Credit_Card_Processing_Arrange1

Credit Card Processing Arrangements (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012
Credit Card Processing Arrangements [Abstract]	'	'	'
Cash collateral required for credit card transactions as a percentage of air traffic liability, prior to amendment	100.00%	'	'
Cash holdback for credit card transactions	'	$0	$0
Maximum potential exposure to cash holdbacks by the credit card processors	'	$188,600,000	$144,800,000

Accrued_Liabilities_Details

Accrued Liabilities (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]	'	'
Aircraft maintenance	$36,165	$22,319
Federal excise and other passenger taxes and fees payable	26,979	23,401
Salaries and wages	26,174	21,057
Airport expenses	17,109	16,024
Fuel	13,819	11,219
Aircraft and facility rent	7,993	8,020
Tax receivable agreement	5,643	7,987
Other	11,380	11,287
Other current liabilities	$145,262	$121,314

Common_Stock_and_Preferred_Sto1

Common Stock and Preferred Stock (Details) (USD $)	0 Months Ended
	Dec. 07, 2011	Dec. 31, 2013	Dec. 31, 2012
Class of Stock [Line Items]	'	'	'
Preferred stock, shares authorized	'	10,000,000	'
Preferred sock, par value per share	'	$0.00	'
Preferred stock, shares outstanding	'	0	0
Common Stock	'	'	'
Class of Stock [Line Items]	'	'	'
Common stock, shares authorized	'	240,000,000	240,000,000
Common stock, par value per share	'	$0.00	$0.00
Common stock, shares outstanding	'	72,566,426	70,801,782
Non-Voting Common Stock	'	'	'
Class of Stock [Line Items]	'	'	'
Common stock, shares authorized	'	50,000,000	50,000,000
Common stock, par value per share	'	$0.00	$0.00
Stock distribution agreement, common stock were exchanged on a share-for-share basis for shares of non-voting common stock	10,576,180	'	'
Common stock, shares outstanding	'	0	1,669,205

StockBased_Compensation_Restri

Stock-Based Compensation - Restricted Stock Activity (Details) (Restricted Stock [Member], USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Restricted Stock [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Award vesting percentage per year	25.00%	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]	'	'	'
Outstanding (in shares)	449,629	'	'
Granted (in shares)	151,202	391,418	0
Vested (in shares)	-168,514	'	'
Forfeited (in shares)	-96,269	'	'
Outstanding (in shares)	336,048	449,629	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'	'	'
Outstanding, weighted-average grant date fair value (in dollars per share)	$16.94	'	'
Granted, weighted-average grant date fair value (in dollars per share)	$27.70	$20.01	'
Vested, weighted-average grant date fair value (in dollars per share)	$13.19	'	'
Forfeited, weighted-average grant date fair value (in dollars per share)	$19.28	'	'
Outstanding, weighted-average grant date fair value (in dollars per share)	$22.99	$16.94	'
Total fair value of shares vested	$4,300,000	$3,900,000	$3,200,000
Total compensation cost not yet recognized	$6,100,000	$6,100,000	'
Total compensation cost not yet recognized, period for recognition	'2 years 8 months 20 days	'3 years 2 months 12 days	'

StockBased_Compensation_Share_

Stock-Based Compensation - Share Option Activity (Details) (Stock Options [Member], USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Options [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Award vesting period	'4 years	'	'
Contractual term	'10 years	'	'
Grants in period (in shares)	0	0	'
Expected volatility factor	'	'	46.25%
Expected dividend yield	'	'	0.00%
Expected term (in years)	'	'	'6 years 3 months
Risk free interest rate	'	'	2.03%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'	'	'
Outstanding (in shares)	247,650	'	'
Exercised (in shares)	-92,400	'	'
Forfeited or expired (in shares)	-98,750	'	'
Outstanding (in shares)	56,500	247,650	'
Exercisable (in shares)	27,125	'	'
Vested or expected to vest (in shares)	56,260	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]	'	'	'
Outstanding, weighted-average exercise price (in dollars per share)	$9.59	'	'
Exercised, weighted-average exercise price (in dollars per share)	$9.22	'	'
Forfeited or expired, weighted-average exercise price (in dollars per share)	$10.70	'	'
Outstanding, weighted-average exercise price (in dollars per share)	$8.26	$9.59	'
Exercisable, weighted-average exercise price (in dollars per share)	$8.12	'	'
Vested or expected to vest, weighted-average exercise price (in dollars per share)	$8.25	'	'
Outstanding, average remaining contractual term (in years)	'6 years 8 months 12 days	'8 years	'
Exercisable, average remaining contractual term (in years)	'6 years 7 months 6 days	'	'
Vested or expected to vest, average remaining contractual term	'6 years 8 months 12 days	'	'
Outstanding, aggregate intrinsic value	$2,099,000	$2,015,000	'
Exercisable, aggregate intrinsic value	1,011,000	'	'
Vested or expected to vest, aggregate intrinsic value	2,090,000	'	'
Granted, weighted-average fair value (in dollars per share)	'	'	$5.73
Total instrinsic value of share options exercised	2,000,000	700,000	200,000
Options, vested in period, fair value	200,000	400,000	300,000
Total compensation cost not yet recognized	$46,700	$650,500	'
Total compensation cost not yet recognized, period for recognition	'9 months 10 days	'1 year 11 months 26 days	'

StockBased_Compensation_Simula

Stock-Based Compensation - Simulation Model Input Variables (Details) (Performance Shares Awards [Member])	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Performance Shares Awards [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Expected volatility factor	41.00%	39.00%
Risk free interest rate	0.33%	0.44%
Expected term (in years)	'2 years 7 months 24 days	'2 years 8 months 19 days
Expected dividend yield	0.00%	'

StockBased_Compensation_Perfor

Stock-Based Compensation - Performance Share Awards (Details) (Performance Shares Awards [Member], USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Performance Shares Awards [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Potential vesting percentage, minimum	0.00%	'
Potential vesting percentage, maximum	200.00%	'
Period for share issuance after vesting	'60 days	'
Expected dividend yield	0.00%	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]	'	'
Outstanding (in shares)	280,907	'
Granted (in shares)	126,147	'
Vested (in shares)	0	'
Forfeited (in shares)	-79,950	'
Outstanding (in shares)	327,104	280,907
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'	'
Outstanding, weighted-average grant date fair value (in dollars per share)	$20.30	'
Granted, weighted-average grant date fair value (in dollars per share)	$28.09	'
Vested, weighted-average grant date fair value (in dollars per share)	$0	'
Forfeited, weighted-average grant date fair value (in dollars per share)	$21.76	'
Outstanding, weighted-average grant date fair value (in dollars per share)	$22.94	$20.30
Total compensation cost not yet recognized	$6,500,000	$6,900,000
Total compensation cost not yet recognized, period for recognition	'1 year 6 months 14 days	'2 years

StockBased_Compensation_Narrat

Stock-Based Compensation - Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2007	Dec. 31, 2013	Dec. 31, 2012	9-May-11
				2005 Stock Plan [Member]	2011 Equity Incentive Award Plan [Member]	2011 Equity Incentive Award Plan [Member]	2011 Equity Incentive Award Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'
Shares authorized for issue (in shares)	'	'	'	2,500,000	'	'	3,000,000
Shares available for future issuance (in shares)	'	'	'	'	2,685,029	2,689,490	'
Share-based compensation cost	$5,689,000	$4,327,000	$530,000	'	'	'	'
Share-based compensation cost, tax benefit recognized in income	$2,100,000	$1,600,000	$189,000	'	'	'	'

Net_Income_per_Share_Details

Net Income per Share (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Numerator:	'	'	'	'	'	'	'	'	'	'	'
Net income	$43,193	$61,103	$42,068	$30,554	$19,566	$30,884	$34,591	$23,419	$176,918	$108,460	$76,448
Denominator:	'	'	'	'	'	'	'	'	'	'	'
Weighted-average shares outstanding, basic	'	'	'	'	'	'	'	'	72,593	72,386	53,241
Effect of dilutive stock awards	'	'	'	'	'	'	'	'	406	205	274
Adjusted weighted-average shares outstanding, diluted	'	'	'	'	'	'	'	'	72,999	72,591	53,515
Net Income per Share:	'	'	'	'	'	'	'	'	'	'	'
Basic earnings per common share (in dollars per share)	$0.59	$0.84	$0.58	$0.42	$0.27	$0.43	$0.48	$0.32	$2.44	$1.50	$1.44
Diluted earnings per common share (in dollars per share)	$0.59	$0.84	$0.58	$0.42	$0.27	$0.43	$0.48	$0.32	$2.42	$1.49	$1.43
Antidilutive awards excluded from computation of earnings per common share (in shares)	'	'	'	'	'	'	'	'	1	88	70

Debt_RelatedParty_Transactions1

Debt, Related-Party Transactions and Other Obligations - Debt (Narrative) (Details) (USD $)	12 Months Ended						12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013
	leases		Line of credit	Line of credit	Line of credit	Line of credit	Quick Engine Change Kit
			Corporate credit cards	Corporate credit cards	Aircraft fuel	Aircraft fuel	leases
Line of Credit Facility [Line Items]	'	'	'	'	'	'	'
Long-term debt outstanding	$0	$0	'	'	'	'	'
Number of capital leases	0	'	'	'	'	'	2
2014	'	1,000,000	'	'	'	'	'
2015	'	1,100,000	'	'	'	'	'
2016	'	1,000,000	'	'	'	'	'
2017	'	0	'	'	'	'	'
2018	'	0	'	'	'	'	'
2019 and thereafter	'	0	'	'	'	'	'
Capital lease obligations outstanding	0	'	'	'	'	'	'
Line of credit, maximum borrowing capacity	'	'	18,600,000	18,600,000	34,500,000	18,000,000	'
Line of credit, amount outstanding	'	'	$3,700,000	$3,200,000	$13,800,000	$11,200,000	'

Debt_RelatedParty_Transactions2

Debt, Related-Party Transactions and Other Obligations - Related Party (Narrative) (Details) (Principal Stockholders, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2011
Principal Stockholders	'
Related Party Transaction [Line Items]	'
Management fee paid to principal stockholders for certain consulting services provided	$0.30

Leases_and_Prepaid_Maintenance2

Leases and Prepaid Maintenance Deposits - Operating Leases (Narrative) (Details) (USD $)

12 Months Ended

12 Months Ended

3 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Jun. 30, 2012

Prepaid expenses and other current assets

Prepaid expenses and other current assets

Aircraft

Aircraft

Aircraft

Other leased equipment and property

Spare engines

Spare engines

Spare engines

Airbus A319

leases

Minimum

Maximum

Maximum

aircraft_engine

Minimum

Maximum

aircraft

Operating Leased Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Operating leases, term

'

'

'

'

'

'

'3 years

'15 years

'25 years

'

'7 years

'12 years

'

Total rental expense

$207,400,000

$172,400,000

$139,100,000

'

'

'

'

'

'

'

'

'

'

Rental expense charged to operations for aircraft and engine operating leases

169,737,000

143,572,000

116,485,000

'

'

'

'

'

'

'

'

'

'

Supplemental rent expense

5,200,000

2,000,000

1,500,000

'

'

'

'

'

'

'

'

'

'

Prepaid aircraft maintenance to lessors, total

220,700,000

198,500,000

'

'

'

'

'

'

'

'

'

'

'

Prepaid aircraft maintenance to lessors, current

'

'

'

59,200,000

76,100,000

'

'

'

'

'

'

'

'

Payments for contingent rent

$1,900,000

$2,000,000

$1,500,000

'

'

'

'

'

'

'

'

'

'

Number of aircraft and spare engines financed under operating leases

'

'

'

'

'

54

'

'

'

9

'

'

'

Number of aircraft and spare engines financed under operating leases with a variable rate

'

'

'

'

'

5

'

'

'

'

'

'

'

Number of aircraft with extended leases

'

'

'

'

'

'

'

'

'

'

'

'

14

Number of aircraft leaes available for renewal

'

'

'

'

'

3

'

'

'

'

'

'

'

Aircraft operating leases, renewal term

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

Aircraft operating leases, period before renewal

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

Leases_and_Prepaid_Maintenance3

Leases and Prepaid Maintenance Deposits - Fixed Maintenance Reserve Payments (Narrative) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Leases And Prepaid Maintenance Deposits [Abstract]	'
Estimated fixed maintenance reserve payments, 2014	$7.40
Estimated fixed maintenance reserve payments, 2015	7.6
Estimated fixed maintenance reserve payments, 2016	8
Estimated fixed maintenance reserve payments, 2017	7.4
Estimated fixed maintenance reserve payments, 2018	5.8
Estimated fixed maintenance reserve payments, 2019 and beyond	$18.40

Leases_and_Prepaid_Maintenance4

Leases and Prepaid Maintenance Deposits - Sale and Leaseback Transactions (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013
	leases	Aircraft	Quick Engine Change Kit	Spare engines
			leases	aircraft_engine
Sale Leaseback Transaction [Line Items]	'	'	'	'
Number of sale-lease-back leases	'	23	'	'
Number of aircraft entered into sale leaseback agreement	'	7	'	'
Sale leaseback transaction on aircraft, net deferred gain (loss)	'	($3.10)	'	'
Sale leaseback transaction on aircraft, refund in pre-delivery deposits	'	$36.70	'	'
Number of spare aircraft engines entered into sale and leaseback agreement	'	'	'	1
Number of capital leases	0	'	2	'
Lease term	'	'	'3 years	'

Leases_and_Prepaid_Maintenance5

Leases and Prepaid Maintenance Deposits - Future Minimum Lease Payments Under Noncancelable Operating Leases (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Capital Leases	'
2014	$1,200
2015	1,200
2016	1,000
2017	0
2018	0
2019 and thereafter	0
Total minimum lease payments	3,400
Less amount representing interest	366
Present value of minimum lease payments	3,034
Less current portion	1,400
Long term portion	1,634
Operating Leases	'
2014	202,666
2015	201,002
2016	194,594
2017	172,468
2018	146,185
2019 and thereafter	526,508
Total minimum lease payments	1,443,423
Aircraft and Spare Engine Leases	'
Operating Leases	'
2014	184,131
2015	184,694
2016	182,984
2017	163,673
2018	139,740
2019 and thereafter	502,102
Total minimum lease payments	1,357,324
Property Facility Leases	'
Operating Leases	'
2014	18,535
2015	16,308
2016	11,610
2017	8,795
2018	6,445
2019 and thereafter	24,406
Total minimum lease payments	$86,099

Leases_and_Prepaid_Maintenance6

Leases and Prepaid Maintenance Deposits - Capital Leased Assets (Details) (Quick Engine Change Kit, USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Capital Leased Assets [Line Items]	'	'
Less: accumulated amortization	$54	$0
Capital leased assets, net	3,180	0
Flight equipment	'	'
Capital Leased Assets [Line Items]	'	'
Flight equipment	$3,234	$0

Financial_Instruments_and_Risk2

Financial Instruments and Risk Management (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative [Line Items]	'	'	'
Derivative instruments and hedges outstanding	$0	'	'
Into-plane fuel cost	542,523,000	471,542,000	392,278,000
Settlement losses (gains)	8,958,000	175,000	-7,436,000
Unrealized mark-to-market losses (gains)	265,000	46,000	3,204,000
Aircraft fuel	$551,746,000	$471,763,000	$388,046,000
Fuel [Member]	'	'	'
Derivative [Line Items]	'	'	'
Nonmonetary notional amount (in gallons)	'	7,800,000	'
Nonmonetary notional amount, percent of required need, coverage, next fiscal year	'	5.00%	'
Weighted average ceiling price (in dollars per gallon)	'	3.09	'
Weighted average floor price (in dollars per gallon)	'	2.84	'

Defined_Contribution_401k_Plan1

Defined Contribution 401(k) Plan (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	defined_contribution_plan
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]	'	'	'
Defined contribution 401(k) plan, number of plans	3	'	'
Defined contribution 401(k) plan, matching contributions made in period	$7,700,000	$6,600,000	$4,900,000
Spirit Airlines, Inc. Employee Retirement Savings Plan	'	'	'
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]	'	'	'
Defined contribution 401(k) plan, requisite service period	'60 days	'	'
Defined contribution 401(k) plan, requisite service period, hours	'1000 hours	'	'
Defined contribution 401(k) plan, requisite age	'21 years	'	'
Defined contribution plan, employer matching contribution, percent of match	50.00%	'	'
Spirit Airlines, Inc. Pilots’ Retirement Savings Plan	'	'	'
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]	'	'	'
Defined contribution 401(k) plan, requisite service period	'60 days	'	'
Defined contribution 401(k) plan, requisite service period, hours	'1000 hours	'	'
Defined contribution 401(k) plan, requisite age	'21 years	'	'
Defined contribution plan, employer matching contribution, percent of match	100.00%	'	'
Defined contribution 401(k) plan, IRS elective deferral limit	17,500	'	'
Spirit Airlines, Inc. Puerto Rico Retirement Savings Plan	'	'	'
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]	'	'	'
Defined contribution 401(k) plan, requisite service period	'60 days	'	'
Defined contribution 401(k) plan, requisite service period, hours	'1000 hours	'	'
Defined contribution 401(k) plan, requisite age	'21 years	'	'
Defined contribution 401(k) plan, IRS elective deferral limit	$17,500	'	'
Maximum | Spirit Airlines, Inc. Employee Retirement Savings Plan	'	'	'
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]	'	'	'
Defined contribution 401(k) plan, maximum employer contribution percent of the employee’s annual compensation	3.00%	'	'
Maximum | Spirit Airlines, Inc. Pilots’ Retirement Savings Plan	'	'	'
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]	'	'	'
Defined contribution 401(k) plan, maximum employer contribution percent of the employee’s annual compensation	8.00%	'	'
Pilots | Spirit Airlines, Inc. Puerto Rico Retirement Savings Plan	'	'	'
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]	'	'	'
Defined contribution plan, employer matching contribution, percent of match	100.00%	'	'
Pilots | Maximum | Spirit Airlines, Inc. Puerto Rico Retirement Savings Plan	'	'	'
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]	'	'	'
Defined contribution 401(k) plan, maximum employer contribution percent of the employee’s annual compensation	8.00%	'	'
Other Employees | Spirit Airlines, Inc. Puerto Rico Retirement Savings Plan	'	'	'
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]	'	'	'
Defined contribution plan, employer matching contribution, percent of match	50.00%	'	'
Other Employees | Maximum | Spirit Airlines, Inc. Puerto Rico Retirement Savings Plan	'	'	'
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]	'	'	'
Defined contribution 401(k) plan, maximum employer contribution percent of the employee’s annual compensation	3.00%	'	'

Income_Taxes_Components_of_the

Income Taxes - Components of the Provision for Income Taxes (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current:	'	'	'
Federal	$86,437	$32,656	$1,866
State and local	6,595	3,250	74
Foreign	413	963	263
Total current expense	93,445	36,869	2,203
Deferred:	'	'	'
Federal	11,658	27,870	42,148
State and local	389	1,385	2,032
Total deferred expense (benefit)	12,047	29,255	44,180
Total income tax expense (benefit)	$105,492	$66,124	$46,383

Income_Taxes_Income_Tax_Reconc

Income Taxes - Income Tax Reconciliation (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Income Tax Expense	'	'	'
Expected provision at federal statutory tax rate	$98,843	$61,104	$42,991
State and foreign tax expense, net of federal benefit	4,695	3,726	2,255
Interest and dividend on preferred stock	0	0	710
Meals and entertainment	772	649	469
Fines and penalties	134	84	-36
Federal credits	-58	-182	-103
Adjustment to deferred tax assets and liabilities	-54	-3	-3
Other	1,160	746	100
Total income tax expense (benefit)	$105,492	$66,124	$46,383

Income_Taxes_Deferred_Taxes_De

Income Taxes - Deferred Taxes (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Deferred tax assets:	'	'
Net operating loss	$188	$83
Deferred loss	1,428	0
Deferred revenue	6,241	5,829
Nondeductible accruals	9,734	6,744
Other	2,767	1,073
Deferred tax assets	20,358	13,729
Deferred tax liabilities:	'	'
Capitalized interest	736	1,125
Deferred gain	0	364
Fuel hedging	0	97
Accrued engine maintenance	45,911	29,497
Property, plant and equipment	6,384	3,271
Deferred tax liabilities	53,031	34,354
Net deferred tax assets (liabilities)	-32,673	-20,625
Assets:	'	'
Other current assets	16,243	12,591
Liabilities:	'	'
Other long-term liabilities	$48,916	$33,216

Income_Taxes_Narrative_Details

Income Taxes - Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Loss Carryforwards [Line Items]	'	'	'
Federal tax credits	'	'	$3,200,000
State net operating loss carryforwards	4,700,000	'	'
Excess tax benefits from share-based compensation	1,927,000	2,098,000	0
Current foreign tax expense (benefit)	413,000	963,000	263,000
Tax Year 2009	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Increase (decrease) in operating loss carryforwards, gross	-7,900,000	'	'
Tax Year 2011	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Increase (decrease) in operating loss carryforwards, gross	3,700,000	'	'
Increase (decrease) in operating loss carryforwards, net	-4,200,000	'	'
Net operating loss carryforwards for federal income tax purposes	16,600,000	'	'
Scenario, Previously Reported	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Net operating loss carryforwards for federal income tax purposes	'	$20,800,000	$20,800,000

Commitments_and_Contingencies_1

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

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Jun. 20, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

aircraft

Aircraft and Related Flight Equipment

Reservation System Provider

Airbus A321

Airbus A321

Airbus A321 NEO

Airbus A320 Family

Airbus A320 NEO

V2500 SelectOne Engine

PurePower PW1100G-JM Engine

aircraft

aircraft

aircraft

aircraft

aircraft

aircraft_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

'

'

'

'

'

'

'

'

'

'

Commitments_and_Contingencies_2

Commitments and Contingencies - Employees (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
	employee_groups	employee_groups
Multiemployer Plans [Line Items]	'	'
Accrued health care claims	2.1	1.9
Unionized employees concentration risk | Number of employees, total	'	'
Multiemployer Plans [Line Items]	'	'
Union-represented employee groups	3	3
Concentration of risk	59.00%	54.00%
Unionized employees concentration risk | Number of employees, total | Association of Flight Attendants [Member]	'	'
Multiemployer Plans [Line Items]	'	'
Concentration of risk	34.00%	'
Unionized employees concentration risk | Number of employees, total | Air Line Pilots Association, International [Member]	'	'
Multiemployer Plans [Line Items]	'	'
Concentration of risk	24.00%	'
Unionized employees concentration risk | Number of employees, total | Transport Workers Union [Member]	'	'
Multiemployer Plans [Line Items]	'	'
Concentration of risk	1.00%	'

Commitments_and_Contingencies_3

Commitments and Contingencies - Schedule of Future Aircraft Operating Leases (Details)	Dec. 31, 2013
	aircraft
Operating Leased Assets [Line Items]	'
2014	11
2015	14
2016	17
2017	20
2018	11
2019	13
2020	13
2021	18
Total future aircraft to be received	117
Airbus 320 | Airbus	'
Operating Leased Assets [Line Items]	'
2014	11
2015	11
2016	5
2017	10
Total future aircraft to be received	37
Airbus A320 NEO | Airbus	'
Operating Leased Assets [Line Items]	'
2018	6
2019	8
2020	13
2021	18
Total future aircraft to be received	45
Airbus A320 NEO | Third-Party Lessor	'
Operating Leased Assets [Line Items]	'
2015	1
2016	4
Total future aircraft to be received	5
Airbus A321 | Airbus	'
Operating Leased Assets [Line Items]	'
2015	2
2016	8
2017	10
2018	5
Total future aircraft to be received	25
Airbus A321 NEO | Airbus	'
Operating Leased Assets [Line Items]	'
2019	5
Total future aircraft to be received	5

Fair_Value_Measurements_Assets

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) (Fair Value, Measurements, Recurring [Member], USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Total [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and cash equivalents	$530.60	$416.80
Total assets	530.6	417.1
Total liabilities	0	0
Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and cash equivalents	530.6	416.8
Total assets	530.6	416.8
Total liabilities	0	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 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and cash equivalents	0	0
Total assets	0	0.3
Total liabilities	0	0
Option contracts [Member] | Total [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative assets	'	0.3
Option contracts [Member] | Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative assets	'	0
Option contracts [Member] | Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative assets	'	0
Option contracts [Member] | Level 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative assets	'	$0.30

Fair_Value_Measurements_Assets1

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis using Significant Unobservable Inputs (Details) (Option contracts [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Option contracts [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'
Beginning balance	$0.30	$0.30	$3.50
Total realized or unrealized gains (losses) included in earnings, net	0.1	-0.2	4.2
Settlements, net	-0.4	0.2	-7.4
Ending balance	$0	$0.30	$0.30

Operating_Segments_and_Related2

Operating Segments and Related Disclosures (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Concentration Risk [Line Items]	'	'	'	'	'	'	'	'	'	'	'
DOT—domestic	'	'	'	'	'	'	'	'	$1,467,500,000	$1,135,100,000	$900,100,000
DOT—Latin America	'	'	'	'	'	'	'	'	186,900,000	183,300,000	171,100,000
Total operating revenue	$419,984,000	$456,625,000	$407,339,000	$370,437,000	$328,268,000	$342,317,000	$346,308,000	$301,495,000	$1,654,385,000	$1,318,388,000	$1,071,186,000
Any individual foreign country | Total passenger revenue | Maximum	'	'	'	'	'	'	'	'	'	'	'
Concentration Risk [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Concentration of risk	'	'	'	'	'	'	'	'	4.00%	4.00%	4.00%

Initial_Public_Offering_and_Ta1

Initial Public Offering and Tax Receivable Agreement (Details) (USD $)	0 Months Ended	3 Months Ended	12 Months Ended					1 Months Ended	12 Months Ended
	Jun. 02, 2011	Jun. 30, 2012	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2012	Mar. 31, 2011	Jun. 02, 2011	Jun. 30, 2011	Dec. 31, 2011	Dec. 31, 2011
				debtors		owner	Class B Common Stock	Initial Public Offering	Initial Public Offering	Initial Public Offering
										Repayments to Unaffiliated Debt Holders
Initial Public Offering [Line Items]	'	'	'	'	'	'	'	'	'	'
Proceeds from initial public offering	$187,200,000	'	'	'	'	'	'	'	'	'
Shares issued in public offering (in shares)	'	'	'	'	'	'	'	15,600,000	'	'
Common stock price at IPO (in dollars per share)	$12	'	'	'	'	'	'	'	'	'
Proceeds from IPO, after underwriter commissions	176,900,000	'	'	'	'	'	'	'	'	'
Proceeds from IPO, after paying debt and direct issuance costs	150,000,000	'	'	'	'	'	'	'	'	'
Debts paid from IPO proceeds	20,600,000	'	'	'	'	'	'	'	'	'
Incurred costs	'	'	'	'	'	'	'	'	2,300,000	500,000
Number of unaffiliated debt holders paid with IPO proceeds (in debtors)	'	'	'	3	'	'	'	'	'	'
Direct IPO costs	5,900,000	'	'	'	'	'	'	'	'	'
Debt exchanged for common stock	279,200,000	'	'	'	'	'	'	'	'	'
Unpaid dividends exchanged for common stock	81,700,000	'	'	'	'	'	'	'	'	'
Common shares exchanged for forgiveness of debt and unpaid dividends (in shares)	30,079,420	'	'	'	'	'	'	'	'	'
Conversion ratio for class B common stock to common stock (in shares)	'	'	'	'	'	'	1	'	'	'
Interest expense reduction from IPO transactions	400,000	'	'	'	'	'	'	'	'	'
Percentage of cash savings from pre-IPO NOLs due to pre-IPO stockholders	'	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	'	'	'	'	'	'	'	'
Interest included in cash payment to pre-IPO stockholders pursuant to tax receivable agreement	'	300,000	'	'	'	'	'	'	'	'
Estimated remaining cash payment to pre-IPO stockholders	'	'	5,643,000	'	7,987,000	'	'	'	'	'
Pre-initial public offering, operating loss carryforwards, reduction	'	'	7,800,000	'	'	'	'	'	'	'
Reduction in TRA liability	'	'	$2,400,000	'	'	'	'	'	'	'

Quarterly_Financial_Data_Unaud2

Quarterly Financial Data (Unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly Financial Information Disclosure [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Total operating revenue	$419,984	$456,625	$407,339	$370,437	$328,268	$342,317	$346,308	$301,495	$1,654,385	$1,318,388	$1,071,186
Operating income	68,061	97,804	66,758	49,669	31,933	49,681	55,132	37,244	282,292	173,990	144,382
Net income	$43,193	$61,103	$42,068	$30,554	$19,566	$30,884	$34,591	$23,419	$176,918	$108,460	$76,448
Basic earnings per share (in dollars per share)	$0.59	$0.84	$0.58	$0.42	$0.27	$0.43	$0.48	$0.32	$2.44	$1.50	$1.44
Diluted earnings per share (in dollars per share)	$0.59	$0.84	$0.58	$0.42	$0.27	$0.43	$0.48	$0.32	$2.42	$1.49	$1.43