Allegiant Travel (ALGT) 10-Q 29 Oct 15 2015 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 15, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	Allegiant Travel CO
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		16,838,157
Amendment Flag	false
Entity Central Index Key	1,362,468
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Well Known Seasoned Issuer	Yes
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3

Consolidated Balance Sheets (Cu

Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
CURRENT ASSETS:
Cash and cash equivalents	$ 78,545	$ 89,610
Restricted cash	13,197	12,021
Short-term investments	246,985	269,817
Accounts receivable	15,712	14,216
Expendable parts, supplies and fuel, net	16,846	16,980
Prepaid expenses	22,817	24,306
Deferred income taxes	6,271	6,271
Other current assets	3,104	406
TOTAL CURRENT ASSETS	403,477	433,627
Property and equipment, net	832,822	738,783
Long-term investments	60,095	57,390
Investment in and advances to unconsolidated affiliates, net	2,797	1,811
Deposits and other assets	4,716	3,469
TOTAL ASSETS	1,303,907	1,235,080
CURRENT LIABILITIES:
Current maturities of long-term debt, net of related costs	69,593	52,605
Accounts payable	7,358	13,232
Accrued liabilities	71,463	110,802
Air traffic liability	209,725	185,315
TOTAL CURRENT LIABILITIES	358,139	361,954
LONG-TERM DEBT AND OTHER LONG-TERM LIABILITIES:
Long-term debt, net of current maturities and related costs	566,159	536,189
Deferred income taxes	45,531	42,872
TOTAL LIABILITIES	969,829	941,015
SHAREHOLDERS' EQUITY:
Common stock, par value $.001	22	22
Treasury stock	(446,515)	(325,396)
Additional paid in capital	229,365	221,257
Accumulated other comprehensive income, net	1,527	1,211
Retained earnings	549,679	395,783
TOTAL ALLEGIANT TRAVEL COMPANY SHAREHOLDERS' EQUITY	334,078	292,877
Noncontrolling interest	0	1,188
TOTAL EQUITY	334,078	294,065
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 1,303,907	$ 1,235,080

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Cash dividend declared per share:	$ 0.30	$ 0	$ 0.80	$ 0
OPERATING REVENUE:
Scheduled service revenue	$ 170,002	$ 166,893	$ 556,842	$ 559,587
Ancillary revenue:
Air-related charges	107,554	77,198	326,055	248,432
Third party products	9,890	8,051	31,663	28,338
Total ancillary revenue	117,444	85,249	357,718	276,770
Fixed fee contract revenue	4,640	4,899	11,993	10,508
Other revenue	7,870	7,988	24,745	11,229
Total operating revenue	299,956	265,029	951,298	858,094
OPERATING EXPENSES:
Aircraft fuel	68,272	94,864	216,985	308,308
Salary and benefits	58,968	52,109	171,119	145,845
Station operations	26,454	21,064	74,768	63,453
Maintenance and repairs	25,369	22,562	70,488	64,590
Sales and marketing	4,053	7,808	16,907	22,269
Aircraft lease rentals	695	1,565	2,092	12,897
Depreciation and amortization	24,346	22,174	73,597	60,355
Other	14,717	14,016	47,402	37,826
Total operating expenses	222,874	236,162	673,358	715,543
OPERATING INCOME	77,082	28,867	277,940	142,551
OTHER (INCOME) EXPENSE:
Earnings from unconsolidated affiliates, net	(67)	(101)	(117)	(173)
Interest income	(301)	(106)	(948)	(545)
Interest expense	6,687	7,097	20,531	13,817
Total other expense	6,319	6,890	19,466	13,099
INCOME BEFORE INCOME TAXES	70,763	21,977	258,474	129,452
PROVISION FOR INCOME TAXES	26,305	7,866	94,853	47,900
NET INCOME	44,458	14,111	163,621	81,552
Net loss attributable to noncontrolling interest	0	(61)	(44)	(340)
NET INCOME ATTRIBUTABLE TO ALLEGIANT TRAVEL COMPANY	$ 44,458	$ 14,172	$ 163,665	$ 81,892
Earnings per share to common shareholders:
Basic (in Dollars per share)	$ 2.63	$ 0.80	$ 9.57	$ 4.56
Diluted (in Dollars per share)	$ 2.62	$ 0.80	$ 9.55	$ 4.54
Weighted average shares outstanding used in computing earnings per share to common shareholders:
Basic (in Shares)	16,831	17,605	17,010	17,848
Diluted (in Shares)	16,869	17,704	17,050	17,912

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
NET INCOME	$ 44,458	$ 14,111	$ 163,621	$ 81,552
OTHER COMPREHENSIVE INCOME:
Change in available-for-sale securities, net of tax	(21)	(125)	377	(85)
Foreign currency translation adjustment, net of tax	(32)	0	230	0
Change in derivatives, net of tax	171	605	712	769
Reclassification of derivative gains into Other revenue	(260)	0	(1,003)	0
Total other comprehensive (loss) income	(142)	480	316	684
TOTAL COMPREHENSIVE INCOME	44,316	14,591	163,937	82,236
Net loss attributable to noncontrolling interest	0	(61)	(44)	(340)
COMPREHENSIVE INCOME ATTRIBUTABLE TO ALLEGIANT TRAVEL COMPANY	$ 44,316	$ 14,652	$ 163,981	$ 82,576

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
OPERATING ACTIVITIES:
NET INCOME	$ 163,621	$ 81,552
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	73,597	60,355
Loss on aircraft and other equipment disposals	3,043	3,967
Provision for obsolescence of expendable parts, supplies and fuel	1,183	956
Amortization of deferred financing costs (original issue discount)	945	(2,209)
Share-based compensation expense	10,736	13,813
Deferred income taxes	2,659	1,332
Excess tax benefits from share-based compensation	(3,868)	(3,339)
Changes in certain assets and liabilities:
Accounts receivable	(1,496)	349
Prepaid expenses	1,489	4,928
Accounts payable	(1,775)	6,194
Accrued liabilities	(2,228)	8,338
Air traffic liability	24,410	27,740
Other, net	(4,706)	(8,822)
Net cash provided by operating activities	267,610	195,154
INVESTING ACTIVITIES:
Purchase of investment securities	(272,970)	(285,918)
Proceeds from maturities of investment securities	293,181	204,306
Purchase of property and equipment, including pre-delivery deposits	(173,926)	(188,131)
Other investing activities	687	753
Net cash used in investing activities	(153,028)	(268,990)
FINANCING ACTIVITIES:
Cash dividends paid to shareholders	(57,410)	(41,787)
Proceeds from the exercise of stock options	3,869	0
Proceeds from the issuance of long-term debt	93,000	385,300
Repurchase of common stock	(121,119)	(129,323)
Principal payments on long-term debt	(46,447)	(155,577)
Other financing activities	2,460	3,709
Net cash (used in) provided by financing activities	(125,647)	62,322
Net change in cash and cash equivalents	(11,065)	(11,514)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	89,610	97,711
CASH AND CASH EQUIVALENTS AT END OF PERIOD	78,545	86,197
Non- cash transactions:
Long-term debt assumed for aircraft	$ 0	$ 141,960

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited consolidated financial statements include the accounts of Allegiant Travel Company (the “Company”) and its majority-owned operating subsidiaries. Investments in affiliates in which the Company’s ownership interest ranges from 20 to 50 percent and in which the Company has the ability to exercise significant influence over operating and financial policies are accounted for under the equity method. All intercompany balances and transactions have been eliminated. These unaudited consolidated financial statements reflect all normal recurring adjustments, which management believes are necessary to present fairly the financial position, results of operations, and cash flows of the Company for the respective periods presented. Certain information and footnote disclosures normally included in the annual consolidated financial statements prepared in accordance with U.S. generally accepted accounting principles ("U.S. GAAP") have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission for Form 10-Q. These unaudited interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements of the Company and notes thereto included in the annual report of the Company on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities, at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates. The interim results reflected in the unaudited condensed consolidated financial statements are not necessarily indicative of the results that may be expected for other interim periods, or for the full year. Reclassifications related to the adoption of ASU 2015-03 have been made to the prior period’s financial statements to conform to 2015 classifications. These reclassifications had no effect on the previously reported net income. Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, intended to create a unified model to determine when and how revenue is recognized. The core principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. On July 9, 2015, the FASB decided to defer the effective date by one year, to December 15, 2017, for annual and interim periods beginning after that date. The FASB has also proposed permitting early adoption of the standard, but not before the original effective date of annual periods beginning after December 15, 2016. The Company is evaluating the impact on its financial statements of adopting this new accounting standard and plans to provide additional information regarding its expected financial impact at a later date. In April 2015, the FASB issued ASU 2015-03, which amends existing guidance and requires the presentation of debt issuance costs on the balance sheet as a reduction of the carrying amount of the related debt liability rather than as a deferred charge, effective for fiscal years, and interim periods within those years, beginning on or after December 15, 2015. The Company has adopted this change in accounting principle as of September 30, 2015. As such, debt issuance costs previously reflected on the balance sheet in deposits and other assets, are now reflected as a reduction to long-term debt, in the amount of $4.1 million and $4.3 million as of September 30, 2015 and December 31, 2014, respectively.

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities The Company’s investments in marketable securities are classified as available-for-sale and are reported at fair market value with the net unrealized gain or loss reported as a component of accumulated other comprehensive income ("AOCI") in shareholders’ equity. Excluded from the following table is the change in fair value attributable to the foreign currency risk being hedged. Refer to Note 6 - Derivative Instruments for additional information related to the Company's foreign currency hedge. Investment securities are classified as cash equivalents, short-term investments, and long-term investments based on maturity date. Cash equivalents have maturities of three months or less, short-term investments have maturities of greater than three months but equal to or less than one year, and long-term investments are those with a maturity date greater than one year. Investment securities (in thousands): As of September 30, 2015 As of December 31, 2014 Net Unrealized Net Unrealized Cost Gains (Losses) Market Value Cost Gains (Losses) Market Value Money market funds $ 2,826 $ — $ — $ 2,826 $ 8,377 $ — $ — $ 8,377 Certificates of deposit — — — — 10,049 2 — 10,051 Commercial paper 90,103 9 (19 ) 90,093 47,941 3 (4 ) 47,940 Municipal debt securities 51,038 7 (3 ) 51,042 105,933 14 (2 ) 105,945 Government debt securities 44,759 12 (10 ) 44,761 24,028 — (31 ) 23,997 Corporate debt securities 110,990 7 (28 ) 110,969 134,770 1 (106 ) 134,665 Federal agency debt securities 20,562 2 — 20,564 4,711 — (1 ) 4,710 Total $ 320,278 $ 37 $ (60 ) $ 320,255 $ 335,809 $ 20 $ (144 ) $ 335,685

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment Disclosure	Property and Equipment Property and equipment (in thousands): As of September 30, 2015 As of December 31, 2014 Flight equipment $ 1,057,549 $ 947,082 Ground property and equipment 141,929 100,916 Total property and equipment 1,199,478 1,047,998 Less accumulated depreciation and amortization 366,656 309,215 Property and equipment, net $ 832,822 $ 738,783

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Long-term debt (in thousands): As of September 30, 2015 As of December 31, 2014 Fixed-rate notes payable due through 2020 $ 344,351 $ 343,625 Variable-rate notes payable due through 2020 291,401 245,169 Total long-term debt, net of related costs 635,752 588,794 Less current maturities 69,593 52,605 Long-term debt, net of current maturities and related costs $ 566,159 $ 536,189 Maturities of long-term debt for the remainder of 2015 and for the next four years and thereafter, in aggregate (in thousands): As of September 30, 2015 Remaining in 2015 $ 17,213 2016 70,219 2017 72,548 2018 128,718 2019 331,424 Thereafter 15,630 Total $ 635,752 Secured Debt In September 2015, the Company borrowed $29.0 million secured by two A319 aircraft. The notes bear interest at a floating rate based on LIBOR plus 1.75 percent and will be payable in quarterly installments through September 2020. In June 2015, the Company borrowed $26.5 million secured by two A319 aircraft. The notes bear interest at a floating rate based on LIBOR plus 1.70 percent and will be payable in quarterly installments through June 2020. In March 2015, the Company borrowed $30.0 million secured by two A319 aircraft. The notes bear interest at a floating rate based on LIBOR plus 1.70 percent , and are payable in quarterly installments through March 2020. In March 2015, the Company borrowed $7.5 million secured by the real estate purchased by the Company in October 2014. The note bears a fixed interest rate of 2.86 percent per annum, and provides for a 25-year amortization and a five-year term.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value, Measurement Inputs, Disclosure	Fair Value Measurements The Company measures certain financial assets and liabilities at fair value on a recurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Accounting standards pertaining to fair value measurements establish a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1 - Defined as observable inputs such as quoted prices in active markets for identical assets or liabilities Level 2 - Defined as inputs other than Level 1 inputs that are either directly or indirectly observable Level 3 - Defined as unobservable inputs for which little or no market data exists, therefore requiring an entity to develop its own assumptions The Company uses the market approach valuation technique to determine fair value for investment securities. The assets classified as Level 1 consist of money market funds for which original cost approximates fair value. The assets classified as Level 2 consist of certificates of deposit, commercial paper, municipal debt securities, federal agency debt securities, government debt securities, and corporate debt securities, which are valued using quoted market prices or alternative pricing sources including transactions involving identical or comparable assets and models utilizing market observable inputs. The Company has no investment securities classified as Level 3. For those assets classified as Level 2 that are not in active markets, the Company obtains fair value from pricing sources using quoted market prices for identical or comparable instruments, and uses pricing models which include all significant observable inputs; maturity dates, issue dates, settlement dates, benchmark yields, reported trades, broker-dealer quotes, issue spreads, benchmark securities, bids, offers and other market related data. These inputs are observable or can be derived from, or corroborated by, observable market data for substantially the full term of the asset. The fair value of the Company's derivative instrument is determined using standard valuation models. The significant inputs used in these models are readily available in public markets or can be derived from observable market transactions and therefore have been classified as Level 2. Inputs used in these standard valuation models for derivative instruments include the applicable exchange and interest rates. Financial instruments measured at fair value on a recurring basis (in thousands): As of Level 1 Level 2 Cash equivalents Money market funds $ 2,826 $ 2,826 $ — Commercial paper 10,349 — 10,349 Total cash equivalents 13,175 2,826 10,349 Short-term Corporate debt securities 92,892 — 92,892 Commercial paper 79,744 — 79,744 Municipal debt securities 48,778 — 48,778 Federal agency debt securities 20,564 — 20,564 Government debt securities 5,007 — 5,007 Total short-term 246,985 — 246,985 Long-term Government debt securities 39,754 — 39,754 Corporate debt securities 18,077 — 18,077 Derivative instruments 2,475 — 2,475 Municipal debt securities 2,264 — 2,264 Total long-term 62,570 — 62,570 Total financial instruments $ 322,730 $ 2,826 $ 319,904 As of Level 1 Level 2 Cash equivalents Money market funds $ 8,377 $ 8,377 $ — Municipal debt securities 101 — 101 Total cash equivalents 8,478 8,377 101 Short-term Corporate debt securities 103,961 — 103,961 Municipal debt securities 103,155 — 103,155 Commercial paper 47,940 — 47,940 Certificates of deposit 10,051 — 10,051 Federal agency debt securities 4,710 — 4,710 Total short-term 269,817 — 269,817 Long-term Corporate debt securities 30,704 — 30,704 Government debt securities 23,997 — 23,997 Municipal debt securities 2,689 — 2,689 Derivative instruments 1,858 — 1,858 Total long-term 59,248 — 59,248 Total financial instruments $ 337,543 $ 8,377 $ 329,166 The fair value of the Company’s publicly held long-term debt is determined based on inputs that are readily available in public markets or can be derived from information available in publicly quoted markets; therefore, the Company has categorized its publicly held debt as Level 2. The remaining debt agreements are not publicly held. The Company has determined the estimated fair value of these notes to be Level 3, as certain inputs used to determine the fair value of these agreements are unobservable and, therefore, could be sensitive to changes in inputs. The Company utilizes the discounted cash flow method to estimate the fair value of Level 3 debt. Carrying value and estimated fair value of long-term debt, including current maturities (in thousands): As of September 30, 2015 As of December 31, 2014 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Hierarchy Level Publicly held debt $ 300,000 $ 300,750 $ 300,000 $ 304,875 2 Non-publicly held debt 339,902 319,859 293,099 270,490 3 Total long-term debt $ 639,902 $ 620,609 $ 593,099 $ 575,365 Due to the short term nature, carrying amounts of cash, cash equivalents, restricted cash, accounts receivable and accounts payable approximate fair value.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2015
Derivative Instruments [Abstract]
Derivative Instruments and Hedging Activities Disclosure	Derivative Instruments In 2014, the Company entered into a foreign currency swap in order to mitigate the foreign currency exchange rate risk associated with the forecasted lease revenue from 12 Airbus A320 series aircraft leased to a European carrier until 2018. The Company uses a cash flow hedge to minimize the variability in cash flows of assets, liabilities and forecasted transactions caused by fluctuations in foreign currency exchange rates. At September 30, 2015 , the net change in fair value recorded in AOCI related to the unrealized gain on the hedge was $0.7 million , when compared to the fair value at December 31, 2014. At inception, the Company formally designated and documented this financial instrument as a hedge of a specific underlying exposure, the risk management objective, and the strategy for undertaking the hedge transaction. The Company also assessed whether the financial instrument used in the hedging transactions was effective at offsetting changes in either the fair values or cash flows of the related underlying exposures. This assessment is monitored on at least a quarterly basis, and the change in fair market value of any ineffective portion of a financial instrument would be immediately recognized into earnings. For the nine months ended September 30, 2015 , the Company realized $0.6 million in net gains from its cash flow hedge into Other revenue, and as of September 30, 2015 , expects $0.6 million to be reclassified from Other comprehensive income into Other revenue within the next 12 months. At September 30, 2015 , the fair value of the Company's derivative instrument was $2.5 million and is reported in the Company's consolidated balance sheet within deposits and other assets. Refer to Note 5 - Fair Value Measurements for additional information related to the estimated fair value.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Stockholders' Equity	Shareholders’ Equity The Company is authorized by the Board of Directors to acquire its stock through open market purchases under its share repurchase program. As repurchase authority is used, the Board of Directors has, to date, authorized additional expenditures for share repurchases. Share repurchases consisted of the following during the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Shares repurchased 175,142 223,147 644,603 953,309 Average price per share $218.67 $118.53 $185.43 $103.44 Total (in thousands) $38,298 $26,449 $119,530 $98,606 During the three months ended September 30, 2015 , the Company declared and paid cash dividends of $0.30 per share, or $5.1 million . During the nine months ended September 30, 2015 , the Company declared and paid cash dividends of $0.80 per share, or $13.7 million .

Earnings per Share

Earnings per Share	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Earnings per Share	Earnings per Share Basic and diluted earnings per share are computed pursuant to the two-class method. Under this method, the Company attributes net income to two classes: common stock and unvested restricted stock. Unvested restricted stock awards granted to employees under the Company’s Long-Term Incentive Plan are considered participating securities as they receive non-forfeitable rights to cash dividends at the same rate as common stock. Diluted net income per share is calculated using the more dilutive of the two methods. Under both methods, the exercise of employee stock options is assumed using the treasury stock method. The assumption of vesting of restricted stock, however, differs: 1. Assume vesting of restricted stock using the treasury stock method. 2. Assume unvested restricted stock awards are not vested, and allocate earnings to common shares and unvested restricted stock awards using the two-class method. For the three and nine months ended September 30, 2015 , the second method, which assumes unvested awards are not vested, was used in the computation because it was more dilutive than the first method. The following table sets forth the computation of net income per share, on a basic and diluted basis, for the periods indicated (share and dollar amounts in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Basic: Net income attributable to Allegiant Travel Company $ 44,458 $ 14,172 $ 163,665 $ 81,892 Less net income allocated to participating securities (199 ) (90 ) (802 ) (586 ) Net income attributable to common stock $ 44,259 $ 14,082 $ 162,863 $ 81,306 Net income per share, basic $ 2.63 $ 0.80 $ 9.57 $ 4.56 Weighted-average shares outstanding 16,831 17,605 17,010 17,848 Diluted: Net income attributable to Allegiant Travel Company $ 44,458 $ 14,172 $ 163,665 $ 81,892 Less net income allocated to participating securities (198 ) — (800 ) (584 ) Net income attributable to common stock $ 44,260 $ 14,172 $ 162,865 $ 81,308 Net income per share, diluted $ 2.62 $ 0.80 $ 9.55 $ 4.54 Weighted-average shares outstanding 16,831 17,605 17,010 17,848 Dilutive effect of stock options, restricted stock and stock-settled stock appreciation rights 68 99 68 101 Adjusted weighted-average shares outstanding under treasury stock method 16,899 17,704 17,078 17,949 Participating securities excluded under two-class method (30 ) N/A (28 ) (37 ) Adjusted weighted-average shares outstanding under two-class method 16,869 N/A 17,050 17,912 For the three and nine months ended September 30, 2015 , anti-dilutive shares excluded from the calculation of earnings per share were not material.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company is subject to certain legal and administrative actions it considers routine to business activities. The Company believes the ultimate outcome of any pending legal or administrative matters will not have a material adverse impact on its financial position, liquidity or results of operations. As of September 30, 2015 , the Company had firm commitments to purchase the following aircraft: Aircraft Type Number of Aircraft Under Contract Airbus A319 10 Airbus A320 5 Future minimum fixed payments for the Company's commitments related to the acquisition of aircraft, airport fees under use and lease agreements, and other operating lease obligations (in thousands): As of September 30, 2015 Remaining in 2015 $ 77,153 2016 118,556 2017 73,576 2018 2,801 2019 2,709 Thereafter 3,150 Total commitments $ 277,945

Related Party

Related Party	9 Months Ended
	Sep. 30, 2015
Related Party Transactions [Abstract]
Related Party Transactions Disclosure	Related Party Transactions The Company previously entered into lease agreements for approximately 70,000 and 10,000 square feet of office space in buildings for which the Company’s Chairman and Chief Executive Officer ("CEO"), and an additional member of its Board of Directors, own minority interests as limited partners. For the nine months ended September 30, 2015 and 2014 , the Company made rent payments under these leases totaling $1.1 million and $2.5 million , respectively. In early 2015, the Company exercised its option to terminate the lease for 70,000 square feet of office space (original expiration in April 2018) which was subsequently challenged by the managing members of that entity. As a result, the Company filed a declaratory judgment action seeking clarification regarding whether the early termination option was properly exercised and the amount owed upon early termination. Game Plane, LLC, a wholly owned subsidiary of the Company, partnered with Alpine Labs, LLC to produce and distribute game shows filmed on Company flights. The Company’s Chairman and CEO owns a 25 percent interest in, and is on the managing board of, Alpine Labs, LLC. For the nine months ended September 30, 2015 and 2014 , the Company made payments of $0.4 million and $2.5 million , respectively, to Alpine Labs, LLC. No further expenses are expected to be incurred related to this transaction. For the nine months ended September 30, 2015 , the Company made payments totaling $2.1 million to entities owned or controlled by the Company's Chairman and CEO for the building of corporate training content. The amount paid during the same period in 2014 was nominal. In October 2015, the Company's Board of Directors approved an additional commitment of $3.5 million to be spent on training content. The project is expected to conclude in 2016. GMS Racing, LLC competes in the NASCAR Camping World Truck Series and ARCA Racing Series. The Company's Chairman and CEO owns a controlling interest in GMS Racing, LLC. During the nine months ended September 30, 2015 , the Company made sponsorship payments in the amount of $2.3 million . An additional payment of $0.2 million will be made in fourth quarter 2015, after which no further payments are anticipated. No payments were made to GMS Racing, LLC during the nine months ended September 30, 2014 . In September 2014, as part of its stock repurchase plan, the Company repurchased all of Andrew Levy's (former President, Director, and Chief Operating Officer) unvested shares of restricted stock ( 23,623 shares at $124.05 ) and all of his unexercised stock options (options to purchase 127,512 shares at exercise prices between $36.97 per share and $108.59 per share) for a total payment of approximately $8.5 million . Also in September 2014, the Company repurchased 200,000 shares of its common stock from its Chairman and CEO at $126.20 per share, for a total purchase price of $25.2 million . The repurchase prices of the common stock listed above were based on the average closing market price of the Company's stock over the five trading days prior to each sale date.

Summary of Significant Accoun16

Summary of Significant Accounting Policies - (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited consolidated financial statements include the accounts of Allegiant Travel Company (the “Company”) and its majority-owned operating subsidiaries. Investments in affiliates in which the Company’s ownership interest ranges from 20 to 50 percent and in which the Company has the ability to exercise significant influence over operating and financial policies are accounted for under the equity method. All intercompany balances and transactions have been eliminated. These unaudited consolidated financial statements reflect all normal recurring adjustments, which management believes are necessary to present fairly the financial position, results of operations, and cash flows of the Company for the respective periods presented. Certain information and footnote disclosures normally included in the annual consolidated financial statements prepared in accordance with U.S. generally accepted accounting principles ("U.S. GAAP") have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission for Form 10-Q. These unaudited interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements of the Company and notes thereto included in the annual report of the Company on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities, at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates. The interim results reflected in the unaudited condensed consolidated financial statements are not necessarily indicative of the results that may be expected for other interim periods, or for the full year.
New Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, intended to create a unified model to determine when and how revenue is recognized. The core principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. On July 9, 2015, the FASB decided to defer the effective date by one year, to December 15, 2017, for annual and interim periods beginning after that date. The FASB has also proposed permitting early adoption of the standard, but not before the original effective date of annual periods beginning after December 15, 2016. The Company is evaluating the impact on its financial statements of adopting this new accounting standard and plans to provide additional information regarding its expected financial impact at a later date. In April 2015, the FASB issued ASU 2015-03, which amends existing guidance and requires the presentation of debt issuance costs on the balance sheet as a reduction of the carrying amount of the related debt liability rather than as a deferred charge, effective for fiscal years, and interim periods within those years, beginning on or after December 15, 2015. The Company has adopted this change in accounting principle as of September 30, 2015. As such, debt issuance costs previously reflected on the balance sheet in deposits and other assets, are now reflected as a reduction to long-term debt, in the amount of $4.1 million and $4.3 million as of September 30, 2015 and December 31, 2014, respectively.

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Summary of Investment Securities	Investment securities (in thousands): As of September 30, 2015 As of December 31, 2014 Net Unrealized Net Unrealized Cost Gains (Losses) Market Value Cost Gains (Losses) Market Value Money market funds $ 2,826 $ — $ — $ 2,826 $ 8,377 $ — $ — $ 8,377 Certificates of deposit — — — — 10,049 2 — 10,051 Commercial paper 90,103 9 (19 ) 90,093 47,941 3 (4 ) 47,940 Municipal debt securities 51,038 7 (3 ) 51,042 105,933 14 (2 ) 105,945 Government debt securities 44,759 12 (10 ) 44,761 24,028 — (31 ) 23,997 Corporate debt securities 110,990 7 (28 ) 110,969 134,770 1 (106 ) 134,665 Federal agency debt securities 20,562 2 — 20,564 4,711 — (1 ) 4,710 Total $ 320,278 $ 37 $ (60 ) $ 320,255 $ 335,809 $ 20 $ (144 ) $ 335,685

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2015
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	Property and equipment (in thousands): As of September 30, 2015 As of December 31, 2014 Flight equipment $ 1,057,549 $ 947,082 Ground property and equipment 141,929 100,916 Total property and equipment 1,199,478 1,047,998 Less accumulated depreciation and amortization 366,656 309,215 Property and equipment, net $ 832,822 $ 738,783

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Summary of Long-Term Debt	Long-term debt (in thousands): As of September 30, 2015 As of December 31, 2014 Fixed-rate notes payable due through 2020 $ 344,351 $ 343,625 Variable-rate notes payable due through 2020 291,401 245,169 Total long-term debt, net of related costs 635,752 588,794 Less current maturities 69,593 52,605 Long-term debt, net of current maturities and related costs $ 566,159 $ 536,189

Long-Term Debt Schedule of Matu

Long-Term Debt Schedule of Maturities of Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2015
Schedule of Maturities of Long-Term Debt [Abstract]
Schedule of Maturities of Long-term Debt	Maturities of long-term debt for the remainder of 2015 and for the next four years and thereafter, in aggregate (in thousands): As of September 30, 2015 Remaining in 2015 $ 17,213 2016 70,219 2017 72,548 2018 128,718 2019 331,424 Thereafter 15,630 Total $ 635,752

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Assets Measured at Fair Value On a Recurring Basis	Financial instruments measured at fair value on a recurring basis (in thousands): As of Level 1 Level 2 Cash equivalents Money market funds $ 2,826 $ 2,826 $ — Commercial paper 10,349 — 10,349 Total cash equivalents 13,175 2,826 10,349 Short-term Corporate debt securities 92,892 — 92,892 Commercial paper 79,744 — 79,744 Municipal debt securities 48,778 — 48,778 Federal agency debt securities 20,564 — 20,564 Government debt securities 5,007 — 5,007 Total short-term 246,985 — 246,985 Long-term Government debt securities 39,754 — 39,754 Corporate debt securities 18,077 — 18,077 Derivative instruments 2,475 — 2,475 Municipal debt securities 2,264 — 2,264 Total long-term 62,570 — 62,570 Total financial instruments $ 322,730 $ 2,826 $ 319,904 As of Level 1 Level 2 Cash equivalents Money market funds $ 8,377 $ 8,377 $ — Municipal debt securities 101 — 101 Total cash equivalents 8,478 8,377 101 Short-term Corporate debt securities 103,961 — 103,961 Municipal debt securities 103,155 — 103,155 Commercial paper 47,940 — 47,940 Certificates of deposit 10,051 — 10,051 Federal agency debt securities 4,710 — 4,710 Total short-term 269,817 — 269,817 Long-term Corporate debt securities 30,704 — 30,704 Government debt securities 23,997 — 23,997 Municipal debt securities 2,689 — 2,689 Derivative instruments 1,858 — 1,858 Total long-term 59,248 — 59,248 Total financial instruments $ 337,543 $ 8,377 $ 329,166
Fair Value, Liabilities Measured on Recurring Basis	Carrying value and estimated fair value of long-term debt, including current maturities (in thousands): As of September 30, 2015 As of December 31, 2014 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Hierarchy Level Publicly held debt $ 300,000 $ 300,750 $ 300,000 $ 304,875 2 Non-publicly held debt 339,902 319,859 293,099 270,490 3 Total long-term debt $ 639,902 $ 620,609 $ 593,099 $ 575,365

Stockholders' Equity Repurchase

Stockholders' Equity Repurchases (Tables)	9 Months Ended
	Sep. 30, 2015
Equity, Class of Treasury Stock [Line Items]
Treasury Stock [Text Block]	Share repurchases consisted of the following during the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Shares repurchased 175,142 223,147 644,603 953,309 Average price per share $218.67 $118.53 $185.43 $103.44 Total (in thousands) $38,298 $26,449 $119,530 $98,606

Earnings per Share (Tables)

Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Computation of Net Income Per Share, Basic and Diluted	The following table sets forth the computation of net income per share, on a basic and diluted basis, for the periods indicated (share and dollar amounts in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Basic: Net income attributable to Allegiant Travel Company $ 44,458 $ 14,172 $ 163,665 $ 81,892 Less net income allocated to participating securities (199 ) (90 ) (802 ) (586 ) Net income attributable to common stock $ 44,259 $ 14,082 $ 162,863 $ 81,306 Net income per share, basic $ 2.63 $ 0.80 $ 9.57 $ 4.56 Weighted-average shares outstanding 16,831 17,605 17,010 17,848 Diluted: Net income attributable to Allegiant Travel Company $ 44,458 $ 14,172 $ 163,665 $ 81,892 Less net income allocated to participating securities (198 ) — (800 ) (584 ) Net income attributable to common stock $ 44,260 $ 14,172 $ 162,865 $ 81,308 Net income per share, diluted $ 2.62 $ 0.80 $ 9.55 $ 4.54 Weighted-average shares outstanding 16,831 17,605 17,010 17,848 Dilutive effect of stock options, restricted stock and stock-settled stock appreciation rights 68 99 68 101 Adjusted weighted-average shares outstanding under treasury stock method 16,899 17,704 17,078 17,949 Participating securities excluded under two-class method (30 ) N/A (28 ) (37 ) Adjusted weighted-average shares outstanding under two-class method 16,869 N/A 17,050 17,912

Commitments and Contingencies C

Commitments and Contingencies Commitments to Purchase (Tables)	9 Months Ended
	Sep. 30, 2015
Commitments to Purchase Aircraft [Abstract]
Long-term Purchase Commitment	As of September 30, 2015 , the Company had firm commitments to purchase the following aircraft: Aircraft Type Number of Aircraft Under Contract Airbus A319 10 Airbus A320 5

Commitments and Contingencies P

Commitments and Contingencies Payments Related to Commitments to Purchase (Tables)	9 Months Ended
	Sep. 30, 2015
Payments Related to Commitments to Purchase [Abstract]
Long-term Purchase Commitment [Table Text Block]	Future minimum fixed payments for the Company's commitments related to the acquisition of aircraft, airport fees under use and lease agreements, and other operating lease obligations (in thousands): As of September 30, 2015 Remaining in 2015 $ 77,153 2016 118,556 2017 73,576 2018 2,801 2019 2,709 Thereafter 3,150 Total commitments $ 277,945

Summary of Significant Accoun26

Summary of Significant Accounting Policies Policies (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Accounting Policies [Abstract]
Debt Issuance Cost	$ 4.1	$ 4.3

Investment Securities (Detail)

Investment Securities (Detail) - Investment Securities - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Cost	$ 320,278	$ 335,809
Gross Unrealized Gains	37	20
Gross Unrealized Losses	(60)	(144)
Market Value	320,255	335,685
Money market funds
Cost	2,826	8,377
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Market Value	2,826	8,377
Certificates of deposit
Cost	0	10,049
Gross Unrealized Gains	0	2
Gross Unrealized Losses	0	0
Market Value	0	10,051
Commercial paper
Cost	90,103	47,941
Gross Unrealized Gains	9	3
Gross Unrealized Losses	(19)	(4)
Market Value	90,093	47,940
Municipal debt securities
Cost	51,038	105,933
Gross Unrealized Gains	7	14
Gross Unrealized Losses	(3)	(2)
Market Value	51,042	105,945
Government debt securities
Cost	44,759	24,028
Gross Unrealized Gains	12	0
Gross Unrealized Losses	(10)	(31)
Market Value	44,761	23,997
Corporate debt securities
Cost	110,990	134,770
Gross Unrealized Gains	7	1
Gross Unrealized Losses	(28)	(106)
Market Value	110,969	134,665
Federal agency debt securities
Cost	20,562	4,711
Gross Unrealized Gains	2	0
Gross Unrealized Losses	0	(1)
Market Value	20,564	4,710
Long Term Investments | Municipal debt securities
Market Value	$ 2,264	$ 2,689

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Flight equipment	$ 1,057,549	$ 947,082
Ground property and equipment	141,929	100,916
Total property and equipment	1,199,478	1,047,998
Less accumulated depreciation and amortization	(366,656)	(309,215)
Property and equipment, net	$ 832,822	$ 738,783

Long-Term Debt Long-Term Debt -

Long-Term Debt Long-Term Debt - Components of Long-Term Debt (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Notes Payable	$ 639,902			$ 593,099
Secured Long-term Debt, Noncurrent	635,752			588,794
Less current maturities	69,593			52,605
Long-term debt, net of current maturities and related costs	566,159			536,189
Due March 2020
Debt Instrument [Line Items]
Interest Rate			1.70%
Due June 2020
Debt Instrument [Line Items]
Interest Rate		1.70%
Fixed Rate Notes Payable Through 2020
Debt Instrument [Line Items]
Notes Payable	344,351			343,625
Variable Rate Notes Payable Through 2020
Debt Instrument [Line Items]
Notes Payable	$ 291,401			$ 245,169

Long-Term Debt (Detail)

Long-Term Debt (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Debt Issuance Cost	$ 4,100	$ 4,300
Secured Long-term Debt, Noncurrent	635,752				$ 588,794
Due September 2020
Secured Long-term Debt, Noncurrent	$ 29,000
Interest Rate	1.75%
Due June 2020
Interest Rate			1.70%
Due March 2020
Interest Rate				1.70%
Airbus A319 | Due September 2020
Debt Instrument, Collateral	2
Airbus A319 | Due June 2020
Debt Instrument, Collateral	2
Airbus A319 | Due March 2020
Debt Instrument, Collateral	2
Notes Payable, One Point Seven Percent, Due March Two Thousand Twenty | Due March 2020
Secured Long-term Debt, Noncurrent				$ 30,000
Notes Payable, One Point Seven Percent, Due June Two Thousand Twenty | Due June 2020
Secured Long-term Debt, Noncurrent			$ 26,500
Notes Payable, Two Point Eight Six Percent, Due March Two Thousand Twenty | Due March 2020
Secured Long-term Debt, Noncurrent				$ 7,500
Interest Rate				2.86%

Long-Term Debt Schedule of Ma31

Long-Term Debt Schedule of Maturities of Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 17,213
Long-term Debt, Maturities, Repayments of Principal in Year Two	70,219
Long-term Debt, Maturities, Repayments of Principal in Year Three	72,548
Long-term Debt, Maturities, Repayments of Principal in Year Four	128,718
Long-term Debt, Maturities, Repayments of Principal in Year Five	331,424
Long-term Debt, Maturities, Repayments of Principal after Year Five	15,630
Long-term Debt, Fair Value	$ 635,752	$ 588,794

Fair Value Measurements (Detail

Fair Value Measurements (Detail) - Fair Value Measurements at Reporting Date Using - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Investment Securities	$ 320,255	$ 335,685
Fair Value, Measurements, Recurring
Cash Equivalents	13,175	8,478
Investment Securities	322,730	337,543
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Cash Equivalents	2,826	8,377
Investment Securities	2,826	8,377
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Cash Equivalents	10,349	101
Investment Securities	319,904	329,166
Fair Value, Measurements, Recurring | Money market funds
Cash Equivalents	2,826	8,377
Fair Value, Measurements, Recurring | Money market funds | Fair Value, Inputs, Level 1
Cash Equivalents	2,826	8,377
Fair Value, Measurements, Recurring | Money market funds | Fair Value, Inputs, Level 2
Cash Equivalents	0	0
Fair Value, Measurements, Recurring | Commercial paper
Cash Equivalents	10,349
Fair Value, Measurements, Recurring | Commercial paper | Fair Value, Inputs, Level 1
Cash Equivalents	0
Fair Value, Measurements, Recurring | Commercial paper | Fair Value, Inputs, Level 2
Cash Equivalents	10,349
Fair Value, Measurements, Recurring | Municipal debt securities
Cash Equivalents		101
Fair Value, Measurements, Recurring | Municipal debt securities | Fair Value, Inputs, Level 1
Cash Equivalents		0
Fair Value, Measurements, Recurring | Municipal debt securities | Fair Value, Inputs, Level 2
Cash Equivalents		101
Short-term Investments | Corporate debt securities
Investment Securities	92,892	103,961
Short-term Investments | Corporate debt securities | Fair Value, Inputs, Level 1
Investment Securities	0	0
Short-term Investments | Corporate debt securities | Fair Value, Inputs, Level 2
Investment Securities	92,892	103,961
Short-term Investments | Fair Value, Measurements, Recurring
Investment Securities	246,985	269,817
Short-term Investments | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Investment Securities	0	0
Short-term Investments | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Investment Securities	246,985	269,817
Short-term Investments | Fair Value, Measurements, Recurring | Commercial paper
Investment Securities	79,744	47,940
Short-term Investments | Fair Value, Measurements, Recurring | Commercial paper | Fair Value, Inputs, Level 1
Investment Securities	0	0
Short-term Investments | Fair Value, Measurements, Recurring | Commercial paper | Fair Value, Inputs, Level 2
Investment Securities	79,744	47,940
Short-term Investments | Fair Value, Measurements, Recurring | Certificates of Deposit
Investment Securities		10,051
Short-term Investments | Fair Value, Measurements, Recurring | Certificates of Deposit | Fair Value, Inputs, Level 1
Investment Securities		0
Short-term Investments | Fair Value, Measurements, Recurring | Certificates of Deposit | Fair Value, Inputs, Level 2
Investment Securities		10,051
Short-term Investments | Fair Value, Measurements, Recurring | Government debt securities
Investment Securities	20,564	4,710
Short-term Investments | Fair Value, Measurements, Recurring | Government debt securities | Fair Value, Inputs, Level 1
Investment Securities	0	0
Short-term Investments | Fair Value, Measurements, Recurring | Government debt securities | Fair Value, Inputs, Level 2
Investment Securities	20,564	4,710
Short-term Investments | Fair Value, Measurements, Recurring | Municipal debt securities
Investment Securities	48,778	103,155
Short-term Investments | Fair Value, Measurements, Recurring | Municipal debt securities | Fair Value, Inputs, Level 1
Investment Securities	0	0
Short-term Investments | Fair Value, Measurements, Recurring | Municipal debt securities | Fair Value, Inputs, Level 2
Investment Securities	48,778	103,155
Short-term Investments | Fair Value, Measurements, Recurring | Federal agency debt securities
Investment Securities	5,007
Short-term Investments | Fair Value, Measurements, Recurring | Federal agency debt securities | Fair Value, Inputs, Level 1
Investment Securities	0
Short-term Investments | Fair Value, Measurements, Recurring | Federal agency debt securities | Fair Value, Inputs, Level 2
Investment Securities	5,007
Long Term Investments | Municipal debt securities
Investment Securities	2,264	2,689
Long Term Investments | Municipal debt securities | Fair Value, Inputs, Level 1
Investment Securities	0	0
Long Term Investments | Municipal debt securities | Fair Value, Inputs, Level 2
Investment Securities	2,264	2,689
Long Term Investments | Federal agency debt securities
Investment Securities	39,754	23,997
Long Term Investments | US Treasury and Government | Fair Value, Inputs, Level 1
Investment Securities	0	0
Long Term Investments | US Treasury and Government | Fair Value, Inputs, Level 2
Investment Securities	39,754	23,997
Long Term Investments | Fair Value, Measurements, Recurring
Investment Securities	62,570	59,248
Long Term Investments | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Investment Securities	0	0
Long Term Investments | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Investment Securities	62,570	59,248
Long Term Investments | Fair Value, Measurements, Recurring | Corporate debt securities
Investment Securities	18,077	30,704
Long Term Investments | Fair Value, Measurements, Recurring | Corporate debt securities | Fair Value, Inputs, Level 1
Investment Securities	0	0
Long Term Investments | Fair Value, Measurements, Recurring | Corporate debt securities | Fair Value, Inputs, Level 2
Investment Securities	18,077	30,704
Long Term Investments | Fair Value, Measurements, Recurring | Derivative Financial Instruments, Assets
Derivative Asset	2,475	1,858
Long Term Investments | Fair Value, Measurements, Recurring | Derivative Financial Instruments, Assets | Fair Value, Inputs, Level 1
Investment Securities	0	0
Long Term Investments | Fair Value, Measurements, Recurring | Derivative Financial Instruments, Assets | Fair Value, Inputs, Level 2
Investment Securities	$ 2,475	$ 1,858

Fair Value Measurements Estimat

Fair Value Measurements Estimated Fair Value of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes Payable	$ 639,902			$ 593,099
Secured Long-term Debt, Noncurrent	635,752			588,794
Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Long-term Debt, Noncurrent	620,609			575,365
Publicly Held Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes Payable	300,000			300,000
Publicly Held Debt | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Long-term Debt, Noncurrent	300,750			304,875
Non-Publicly Held Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes Payable	339,902			293,099
Non-Publicly Held Debt | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Long-term Debt, Noncurrent	$ 319,859			$ 270,490
Due March 2020 | Notes Payable, One Point Seven Percent, Due March Two Thousand Twenty
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Long-term Debt, Noncurrent			$ 30,000
Due March 2020 | Notes Payable, Two Point Eight Six Percent, Due March Two Thousand Twenty
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Long-term Debt, Noncurrent			$ 7,500
Due June 2020 | Notes Payable, One Point Seven Percent, Due June Two Thousand Twenty
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Long-term Debt, Noncurrent		$ 26,500

Derivative Instruments Derivati

Derivative Instruments Derivative Instruments - Textuals (Details) - USD ($)	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Derivative [Line Items]
Assets	$ 1,303,907,000	$ 1,235,080,000
Derivative, Gain (Loss) on Derivative, Net	642,000
Change in Unrealized Gain (Loss) on Foreign Currency Fair Value Hedging Instruments	712,000
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	632,000
Derivative, Notional Amount	$ 2,475,000
Airbus A320 Aircraft Series
Derivative [Line Items]
Assets			$ 12

Stockholders' Equity (Detail)

Stockholders' Equity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Stock Repurchased During Period, Shares	175,142	223,147	644,603	953,309
Treasury Stock Acquired, Average Cost Per Share	$ 218.67	$ 118.53	$ 185.43	$ 103.44
Stock Repurchased During Period, Value	$ 38,298	$ 26,449	$ 119,530	$ 98,606
Dividends	$ 5,095		$ 13,694
Common Stock, Dividends, Per Share, Cash Paid	$ 0.30		$ 0.80

Earnings per Share (Detail) - E

Earnings per Share (Detail) - Earnings Per Share - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Basic:
Net income attributable to Allegiant Travel Company (in Dollars)	$ 44,458	$ 14,172	$ 163,665	$ 81,892
Less: Net income allocated to participating securities (in Dollars)	(199)	(90)	(802)	(586)
Net income attributable to common stock (in Dollars)	$ 44,259	$ 14,082	$ 162,863	$ 81,306
Net income per share, basic (in Dollars per share)	$ 2.63	$ 0.80	$ 9.57	$ 4.56
Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted	$ (198)	$ 0	$ (800)	$ (584)
Net income attributable to common stock (in Dollars)	$ 44,260	$ 14,172	$ 162,865	$ 81,308
Net income per share, diluted (in Dollars per share)	$ 2.62	$ 0.80	$ 9.55	$ 4.54
Weighted-average shares outstanding	16,831	17,605	17,010	17,848
Dilutive effect of stock options, restricted stock and stock-settled stock appreciation rights	68	99	68	101
Adjusted weighted-average shares outstanding under treasury stock method	16,899	17,704	17,078	17,949
Participating securities excluded under two-class method	(30)		(28)	(37)
Two-Class Method, Weighted Average Number of Shares Outstanding, Diluted	16,869		17,050	17,912

Commitments and Contingencies (

Commitments and Contingencies (Detail)	Sep. 30, 2015aircraft
Airbus A319
Long-term Purchase Commitment [Line Items]
Number Of Aircraft Committed To Purchase	10
Airbus A320
Long-term Purchase Commitment [Line Items]
Number Of Aircraft Committed To Purchase	5

Commitments and Contingencies38

Commitments and Contingencies Payments Related to Commitments to Purchase (Details) $ in Thousands	Sep. 30, 2015USD ($)
Payments Related to Commitments to Purchase [Abstract]
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	$ 77,153
Unrecorded Unconditional Purchase Obligation, Due within Two Years	118,556
Unrecorded Unconditional Purchase Obligation, Due within Three Years	73,576
Unrecorded Unconditional Purchase Obligation, Due within Four Years	2,801
Unrecorded Unconditional Purchase Obligation, Due within Five Years	2,709
Unrecorded Unconditional Purchase Obligation, Due after Five Years	3,150
Unrecorded Unconditional Purchase Obligation	$ 277,945

Related Party (Details)

Related Party (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 02, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Office Space
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction			$ 1,087	$ 2,501
Game Plane, LLC
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction			365	2,533
GMS Racing, LLC
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction			2,300
Corporate Training
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction			$ 2,097
Building 1
Related Party Transaction [Line Items]
Related Party Transaction, Description of Transaction			70,000
Building 2
Related Party Transaction [Line Items]
Related Party Transaction, Description of Transaction			10,000
Chief Executive Officer
Related Party Transaction [Line Items]
Accelerated Share Repurchases, Final Price Paid Per Share		$ 126.20
Total Stock Repurchased, Shares		200,000
Total Stock Repurchased, Value		$ 25,240
Chief Executive Officer | GMS Racing, LLC
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction				$ 0
Chief Executive Officer | Beneficial Owner | Stock Ownership
Related Party Transaction [Line Items]
Related Party, Ownership Percentage			25.00%
Chief Operating Officer
Related Party Transaction [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number		23,623		23,623
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares		127,512		127,512
Accelerated Share Repurchases, Final Price Paid Per Share		$ 124.05
Chief Operating Officer | Beneficial Owner | Stock Ownership
Related Party Transaction [Line Items]
Stock Repurchased During Period Through Private Transactions, Value		$ 8,500
Minimum | Chief Operating Officer
Related Party Transaction [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price		$ 36.97		$ 36.97
Maximum | Chief Operating Officer
Related Party Transaction [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price		$ 108.59		$ 108.59
Subsequent Event | GMS Racing, LLC
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction	$ 200
Subsequent Event | Corporate Training
Related Party Transaction [Line Items]
Board Approved Spending	$ 3,500