Allegiant Travel (ALGT) 10-Q 1 Aug 16 2016 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2016	Jul. 15, 2016
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		16,483,224
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	Jun. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q2

Consolidated Balance Sheets (Cu

Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
CURRENT ASSETS:
Cash and cash equivalents	$ 105,683	$ 87,112
Restricted cash	10,436	10,358
Short-term investments	255,424	245,583
Accounts receivable	20,041	15,146
Expendable parts, supplies and fuel, net	16,584	15,583
Prepaid expenses	17,692	18,276
Other current assets	2,041	3,185
TOTAL CURRENT ASSETS	427,901	395,243
Property and equipment, net	937,125	885,942
Long-term investments	72,882	64,752
Deposits and other assets	9,057	5,725
TOTAL ASSETS	1,446,965	1,351,662
CURRENT LIABILITIES:
Accounts payable	10,306	6,801
Accrued liabilities	109,934	109,462
Air traffic liability	240,867	198,136
Current maturities of notes payable, net of related costs	80,085	74,069
TOTAL CURRENT LIABILITIES	441,192	388,468
Long-term debt, net of current maturities and related costs	550,636	567,609
Deferred income taxes	48,395	45,580
TOTAL LIABILITIES	1,040,223	1,001,657
SHAREHOLDERS' EQUITY:
Common stock, par value $.001	22	22
Treasury stock	(515,777)	(453,415)
Additional paid in capital	232,303	228,945
Accumulated other comprehensive income, net	375	834
Retained earnings	689,819	573,619
TOTAL EQUITY	406,742	350,005
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 1,446,965	$ 1,351,662

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Cash dividend declared per share:	$ 0.70	$ 0.25	$ 1	$ 0.50
OPERATING REVENUE:
Scheduled service revenue	$ 189,122	$ 186,311	$ 390,728	$ 386,840
Ancillary revenue:
Air-related charges	128,713	113,432	249,643	218,501
Third party products	11,965	10,976	23,223	21,773
Total ancillary revenue	140,678	124,408	272,866	240,274
Fixed fee contract revenue	6,706	2,986	13,507	7,353
Other revenue	8,345	8,397	16,366	16,874
Total operating revenue	344,851	322,102	693,467	651,341
OPERATING EXPENSES:
Aircraft fuel	60,005	79,087	113,663	148,713
Salary and benefits	68,553	53,598	137,761	112,151
Station operations	33,328	24,462	64,061	48,314
Maintenance and repairs	29,261	23,727	55,753	45,119
Depreciation and amortization	25,396	24,904	50,081	49,251
Selling and Marketing Expense	5,317	5,753	11,125	12,854
Aircraft Rental	219	680	452	1,398
Other	18,296	17,135	34,968	32,687
Total operating expenses	240,375	229,346	467,864	450,487
OPERATING INCOME	104,476	92,756	225,603	200,854
OTHER (INCOME) EXPENSE:
Interest income	(938)	(542)	(1,903)	(647)
Interest expense	7,390	7,017	14,629	13,843
Other, net	(72)	(55)	(81)	(51)
Total other expense	6,380	6,420	12,645	13,145
INCOME BEFORE INCOME TAXES	98,096	86,336	212,958	187,709
PROVISION FOR INCOME TAXES	37,249	31,997	80,131	68,548
NET INCOME	60,847	54,339	132,827	119,161
Net loss attributable to noncontrolling interest	0	0	0	(44)
NET INCOME ATTRIBUTABLE TO ALLEGIANT TRAVEL COMPANY	$ 60,847	$ 54,339	$ 132,827	$ 119,205
Earnings per share to common stockholders:
Basic	$ 3.69	$ 3.19	$ 8.09	$ 6.95
Diluted	$ 3.68	$ 3.18	$ 8.07	$ 6.93
Shares used for computation:
Basic	16,420	16,954	16,340	17,073
Diluted	16,442	16,992	16,365	17,114

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net income	$ 60,847	$ 54,339	$ 132,827	$ 119,161
Other comprehensive income (loss):
Change in available for sale securities, net of tax	148	95	439	398
Foreign currency translation adjustment	43	263	(63)	263
Change in derivatives, net of tax	6	(454)	(325)	540
Reclassification of derivative gains into Other revenue	(245)	(266)	(510)	(743)
Total other comprehensive (loss) income	(48)	(362)	(459)	458
TOTAL COMPREHENSIVE INCOME	60,799	53,977	132,368	119,619
Net loss attributable to noncontrolling interest	0	0	0	(44)
COMPREHENSIVE INCOME ATTRIBUTABLE TO ALLEGIANT TRAVEL COMPANY	$ 60,799	$ 53,977	$ 132,368	$ 119,663

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Statement of Cash Flows [Abstract]
Interest Paid, Net	$ 11,936	$ 12,684
OPERATING ACTIVITIES:
Net income	132,827	119,161
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	50,081	49,251
(Gain) loss on aircraft and other equipment disposals	(472)	1,636
Provision for obsolescence of expendable parts, supplies and fuel	1,043	780
Amortization of deferred financing costs	745	697
Share-based compensation expense	3,002	6,282
Deferred income taxes	2,753	1,719
Excess tax benefits from share-based compensation	0	(1,970)
Changes in certain assets and liabilities:
Accounts receivable	(4,895)	212
Prepaid expenses	584	(631)
Accounts payable	3,505	1,121
Accrued liabilities	28,556	13,909
Air traffic liability	42,731	37,269
Other, net	(4,361)	1,309
Net cash provided by operating activities	256,099	230,745
INVESTING ACTIVITIES:
Purchase of investment securities	(197,611)	(162,090)
Proceeds from maturities of investment securities	180,078	168,023
Purchase of property and equipment, including pre-delivery deposits	(105,177)	(132,489)
Other investing activities	3,773	(271)
Net cash used by investing activities	(118,937)	(126,827)
FINANCING ACTIVITIES:
Cash dividends paid to shareholders	(44,355)	(52,315)
Proceeds from the issuance of long-term debt	28,000	64,000
Repurchase of common stock	(63,319)	(82,787)
Principal payments on long-term debt	(39,210)	(29,483)
Other financing activities	293	528
Net cash used by financing activities	(118,591)	(100,057)
Net change in cash and cash equivalents	18,571	3,861
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	87,112	89,610
CASH AND CASH EQUIVALENTS AT END OF PERIOD	105,683	93,471
Non- cash transactions:
Income Taxes Paid, Net	$ 59,928	$ 53,903

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2016
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, 2015, 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 may differ from these estimates. The interim results reflected in the unaudited consolidated financial statements are not necessarily indicative of the results that may be expected for other interim periods, or for the full year. Recent Accounting Pronouncements In March 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2016-09, which is intended to simplify various aspects related to how share-based payments are accounted for and presented in the financial statements. This ASU is effective for fiscal years, and interim periods within those years, beginning on or after December 15, 2016 and early adoption is permitted. The Company has adopted the changes related to income taxes and cash flow presentation for excess tax benefits as of March 31, 2016 on a prospective basis, and prior periods have not been retrospectively adjusted. The remaining provisions of this ASU do not have an impact on the Company's consolidated financial statements. In February 2016, the FASB issued ASU 2016-02 related to leases. This standard will require leases with durations greater than twelve months to be recognized on the balance sheet and is effective for interim and annual reporting periods beginning after December 15, 2018 with early adoption permitted. The Company is currently assessing the impact of this new standard, specifically on its consolidated balance sheets, but does not expect adoption to significantly change the recognition, measurement or presentation of lease expenses within the consolidated statements of income or cash flows. In May 2014, the FASB issued ASU 2014-09, intended to create a unified model to determine when and how revenue is recognized. Subsequently, the FASB has issued several additional ASUs to clarify the implementation guidance for numerous aspects of this standard which applies to all companies entering into contracts with customers to transfer goods or services. 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 for which the entity expects to be entitled in exchange for those goods or services. The standard is effective for for annual and interim periods beginning after December 15, 2017. Early adoption of the standard is permitted, but not before December 15, 2016. The Company is currently evaluating the impact on its financial statements of adopting this new accounting standard.

Update to Accounting Policies (

Update to Accounting Policies (Notes)	6 Months Ended
	Jun. 30, 2016
Update to Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	Update to Accounting Policies Prior to the quarter ended June 30, 2016, the Company's Airbus A320 series aircraft (and Boeing 757-200) had not experienced any major maintenance events, so a method to account for major maintenance events had not yet been applied. The first major maintenance events for the Airbus A320 series aircraft occurred during the second quarter 2016. The Company accounts for major maintenance costs for its MD-80 airframes and the related JT8D-219 engines using the direct expense method. Under this method, major maintenance costs are charged to expense as incurred. The Company accounts for major maintenance costs for its Airbus airframes and the related CFM engines using the deferral method. Under this method, the Company capitalizes the cost of major maintenance events, which are amortized, as a component of depreciation and amortization expense, over the estimated period until the next scheduled major maintenance event. The Company has not experienced any major maintenance events for the Boeing 757-200 fleet.

Investment Securities

Investment Securities	6 Months Ended
	Jun. 30, 2016
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 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 7 - 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 June 30, 2016 As of December 31, 2015 Unrealized Unrealized Cost Gains (Losses) Market Value Cost Gains (Losses) Market Value Commercial paper $ 130,256 $ 35 $ (57 ) $ 130,234 $ 83,155 $ — $ (1 ) $ 83,154 Corporate debt securities 103,216 61 (26 ) 103,251 108,485 50 (154 ) 108,381 US Treasury bond 59,142 19 (2 ) 59,159 1,607 — (1 ) 1,606 Municipal debt securities 27,540 1 (7 ) 27,534 52,669 2 (1 ) 52,670 Money market funds 9,639 — — 9,639 781 — — 781 Federal agency debt securities 9,313 14 — 9,327 73,783 — (80 ) 73,703 Total $ 339,106 $ 130 $ (92 ) $ 339,144 $ 320,480 $ 52 $ (237 ) $ 320,295

Property and Equipment

Property and Equipment	6 Months Ended
	Jun. 30, 2016
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment Disclosure	Property and Equipment Property and equipment (in thousands): As of June 30, 2016 As of December 31, 2015 Flight equipment $ 1,195,320 $ 1,123,115 Computer hardware and software 92,221 78,200 Ground property and equipment 75,098 72,078 Total property and equipment 1,362,639 1,273,393 Less accumulated depreciation and amortization (425,514 ) (387,451 ) Property and equipment, net $ 937,125 $ 885,942

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Long-term debt (in thousands): As of June 30, 2016 As of December 31, 2015 Fixed-rate notes payable due through 2020 $ 336,889 $ 341,738 Variable-rate notes payable due through 2021 293,832 299,940 Total long-term debt, net of related costs 630,721 641,678 Less current maturities 80,085 74,069 Long-term debt, net of current maturities and related costs $ 550,636 $ 567,609 Maturities of long-term debt for the remainder of 2016 and for the next four years and thereafter, in aggregate (in thousands): As of June 30, 2016 Remaining in 2016 $ 39,762 2017 81,378 2018 138,409 2019 342,634 2020 27,034 Thereafter 1,504 Total $ 630,721 Secured Debt In January 2016, the Company received $28.0 million of proceeds from notes executed in December 2015. The notes bear interest at a floating rate based on LIBOR plus 1.75 percent , are payable in quarterly installments through January 2021, and are secured by two Airbus A319 aircraft.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2016
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 by selling 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. These tiers include: 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; and 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 commercial paper, municipal debt securities, federal agency debt securities, US Treasury Bonds, 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 $ 9,639 $ 9,639 $ — Commercial paper 1,199 — 1,199 Total cash equivalents 10,838 9,639 1,199 Short-term Commercial paper 129,035 — 129,035 Corporate debt securities 81,087 — 81,087 Municipal debt securities 27,534 — 27,534 US Treasury Bonds 11,749 — 11,749 Federal agency debt securities 6,019 — 6,019 Total short-term 255,424 — 255,424 Long-term US Treasury Bonds 47,410 — 47,410 Corporate debt securities 22,164 — 22,164 Federal agency debt securities 3,308 — 3,308 Derivative instruments 1,816 — 1,816 Total long-term 74,698 — 74,698 Total financial instruments $ 340,960 $ 9,639 $ 331,321 As of Level 1 Level 2 Cash equivalents Commercial paper $ 8,426 $ — $ 8,426 Money market funds 781 781 — Municipal debt securities 754 — 754 Total cash equivalents 9,961 781 9,180 Short-term Corporate debt securities 80,957 — 80,957 Commercial paper 74,728 — 74,728 Municipal debt securities 47,073 — 47,073 Federal agency debt securities 42,825 — 42,825 Total short-term 245,583 — 245,583 Long-term Federal agency debt securities 30,878 — 30,878 Corporate debt securities 27,425 — 27,425 Municipal debt securities 4,843 — 4,843 Derivative instruments 2,480 — 2,480 US Treasury Bonds 1,606 — 1,606 Total long-term 67,232 — 67,232 Total financial instruments $ 322,776 $ 781 $ 321,995 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 and excluding related costs (in thousands): As of June 30, 2016 As of December 31, 2015 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Hierarchy Level Publicly held debt $ 300,000 $ 312,750 $ 300,000 $ 299,250 2 Non-publicly held debt 334,958 314,325 346,179 327,321 3 Total long-term debt $ 634,958 $ 627,075 $ 646,179 $ 626,571 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	6 Months Ended
	Jun. 30, 2016
Derivative Instruments [Abstract]
Derivative Instruments and Hedging Activities Disclosure	Derivative Instruments 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. For the six months ended June 30, 2016 , the net change in fair value recorded in accumulated other comprehensive income related to the unrealized loss on the hedge was $0.3 million compared to an unrealized gain of $0.5 million for the six months ended June 30, 2015. 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 six months ended June 30, 2016 , the Company realized $0.5 million in gains from its cash flow hedge into Other revenue, compared to $0.7 million for the six months ended June 30, 2015. As of June 30, 2016 , the Company expects $0.6 million to be reclassified from Other comprehensive income into Other revenue within the next 12 months. At June 30, 2016 , the fair value of the Company's derivative instrument was $1.8 million compared to $2.5 million at December 31, 2015, and is reported in the Company's consolidated balance sheet within deposits and other assets. Refer to Note 6 - Fair Value Measurements for additional information related to the estimated fair value.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2016
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 June 30, Six Months Ended June 30, 2016 2015 2016 2015 Shares repurchased (not in thousands) 55,148 178,327 369,997 469,461 Average price per share $139.08 $160.38 $166.70 $173.03 Total (in thousands) $7,670 $28,600 $61,679 $81,232 During the three months ended June 30, 2016 , the Company declared and paid recurring cash dividends of $0.70 per share, or $11.6 million . During the six months ended June 30, 2016, the Company declared and paid cash dividends of $1.00 per share, or $16.6 million .

Earnings per Share

Earnings per Share	6 Months Ended
	Jun. 30, 2016
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 six months ended June 30, 2016 , 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 count and dollar amounts in chart are in thousands): Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Basic: Net income attributable to Allegiant Travel Company $ 60,847 $ 54,339 $ 132,827 $ 119,205 Less net income allocated to participating securities (283 ) (265 ) (663 ) (609 ) Net income attributable to common stock $ 60,564 $ 54,074 $ 132,164 $ 118,596 Net income per share, basic $ 3.69 $ 3.19 $ 8.09 $ 6.95 Weighted-average shares outstanding 16,420 16,954 16,340 17,073 Diluted: Net income attributable to Allegiant Travel Company $ 60,847 $ 54,339 $ 132,827 $ 119,205 Less net income allocated to participating securities (350 ) (265 ) (765 ) (607 ) Net income attributable to common stock $ 60,497 $ 54,074 $ 132,062 $ 118,598 Net income per share, diluted $ 3.68 $ 3.18 $ 8.07 $ 6.93 Weighted-average shares outstanding 16,420 16,954 16,340 17,073 Dilutive effect of stock options, restricted stock and stock-settled stock appreciation rights 36 59 42 71 Adjusted weighted-average shares outstanding under treasury stock method 16,456 17,013 16,382 17,144 Participating securities excluded under two-class method (14 ) (21 ) (17 ) (30 ) Adjusted weighted-average shares outstanding under two-class method 16,442 16,992 16,365 17,114 For the three and six months ended June 30, 2016 , anti-dilutive shares excluded from the calculation of earnings per share were 20,415 and 41,838 , respectively (shares not in thousands). For the three and six months ended June 30, 2015, anti-dilutive shares excluded were not material.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2016
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 June 30, 2016 , the Company had firm commitments to purchase the following aircraft: Aircraft Type Number of Aircraft Under Contract Airbus A319 7 Airbus A320 15 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) are as follows: As of June 30, 2016 Remaining in 2016 $ 65,980 2017 135,728 2018 67,367 2019 78,837 2020 42,447 Thereafter 3,361 Total commitments $ 393,720 See Note 13 below concerning commitments entered into subsequent to June 30, 2016.

Related Party

Related Party	6 Months Ended
	Jun. 30, 2016
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 owned minority interests as limited partners. For the six months ended June 30, 2015 , the Company made rent payments of $1.0 million under the terms of these agreements. Beginning in 2016, payments for the 10,000 square feet of office space are no longer being made to a related party entity as the lender has taken ownership of the property. Additionally, the Company exercised its option to terminate the lease for 70,000 square feet of space effective in May 2015. The Company paid $1.3 million in January 2016 in settlement of litigation in connection with the termination of this lease. 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 six months ended June 30, 2015 , the Company made payments of $0.4 million to Alpine Labs, LLC. No payments were made for the six months ended June 30, 2016 , as no additional shows are being filmed. The Company does not expect any further expenses related to this project. 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 six months ended June 30, 2015, the Company made sponsorship payments totaling $1.5 million to GMS Racing, LLC. No payments were made for the six months ended June 30, 2016 and no future payments are anticipated. Entities owned or controlled by the Company's Chairman and CEO have been paid for the building of corporate training content, with a current focus on the Company's operating groups. This approach to training focuses on concept mastery, recognizing that individuals learn at varying paces, through different styles, and is designed to ensure the trainee fully understands each module before moving on to more advanced training. The Company also expects program development to facilitate recurrent training and to contribute to cost savings in the future, and is in the process of seeking approval from the Federal Aviation Administration ("FAA") on various aspects of this training program. During the six months ended June 30, 2015 and 2016, the Company made payments to these entities of $1.0 million and $1.4 million , respectively. The project is expected to conclude in 2016.

Fuel Tax Refunds (Notes)

Fuel Tax Refunds (Notes)	6 Months Ended
	Jun. 30, 2016
Fuel [Abstract]
Other Income and Other Expense Disclosure [Text Block]	Fuel Tax Refunds During the second quarter 2016, the Company received a $5.4 million fuel tax refund from the State of Florida, as well as recorded $2.9 million in receivables for which claims have been submitted and funds are expected to be received by the end of 2016. These refunds are reflected as a decrease to Aircraft fuel expense on the Company's consolidated statements of income.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2016
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events In July 2016, the Company executed a purchase agreement for 12 new Airbus A320 aircraft for which delivery is expected in 2017 and 2018. In July 2016, the Company drew down $50.4 million against its senior secured revolving credit facility entered into in December 2015. Notes under this facility bear interest at a floating rate based on LIBOR and are due in December 2017. Also in July 2016, the Company borrowed $42.0 million secured by three Airbus A320 series aircraft. The notes bear interest at a floating rate based on LIBOR and will be payable in quarterly installments through July 2021. The Company reached a tentative agreement with the International Brotherhood of Teamsters for a collective bargaining agreement with its pilots in the second quarter 2016. The agreement was ratified by the Company's pilots in July 2016, and provides for enhancements to pay scales, benefits, and limited work rules. Estimated expenses over the five-year agreement term are expected to have a significant impact on the Company's results of operations.

Summary of Significant Accoun19

Summary of Significant Accounting Policies - (Policies)	6 Months Ended
	Jun. 30, 2016
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, 2015, 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 may differ from these estimates. The interim results reflected in the unaudited 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 March 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2016-09, which is intended to simplify various aspects related to how share-based payments are accounted for and presented in the financial statements. This ASU is effective for fiscal years, and interim periods within those years, beginning on or after December 15, 2016 and early adoption is permitted. The Company has adopted the changes related to income taxes and cash flow presentation for excess tax benefits as of March 31, 2016 on a prospective basis, and prior periods have not been retrospectively adjusted. The remaining provisions of this ASU do not have an impact on the Company's consolidated financial statements. In February 2016, the FASB issued ASU 2016-02 related to leases. This standard will require leases with durations greater than twelve months to be recognized on the balance sheet and is effective for interim and annual reporting periods beginning after December 15, 2018 with early adoption permitted. The Company is currently assessing the impact of this new standard, specifically on its consolidated balance sheets, but does not expect adoption to significantly change the recognition, measurement or presentation of lease expenses within the consolidated statements of income or cash flows. In May 2014, the FASB issued ASU 2014-09, intended to create a unified model to determine when and how revenue is recognized. Subsequently, the FASB has issued several additional ASUs to clarify the implementation guidance for numerous aspects of this standard which applies to all companies entering into contracts with customers to transfer goods or services. 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 for which the entity expects to be entitled in exchange for those goods or services. The standard is effective for for annual and interim periods beginning after December 15, 2017. Early adoption of the standard is permitted, but not before December 15, 2016. The Company is currently evaluating the impact on its financial statements of adopting this new accounting standard.

Investment Securities (Tables)

Investment Securities (Tables)	6 Months Ended
	Jun. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Summary of Investment Securities	Investment securities (in thousands): As of June 30, 2016 As of December 31, 2015 Unrealized Unrealized Cost Gains (Losses) Market Value Cost Gains (Losses) Market Value Commercial paper $ 130,256 $ 35 $ (57 ) $ 130,234 $ 83,155 $ — $ (1 ) $ 83,154 Corporate debt securities 103,216 61 (26 ) 103,251 108,485 50 (154 ) 108,381 US Treasury bond 59,142 19 (2 ) 59,159 1,607 — (1 ) 1,606 Municipal debt securities 27,540 1 (7 ) 27,534 52,669 2 (1 ) 52,670 Money market funds 9,639 — — 9,639 781 — — 781 Federal agency debt securities 9,313 14 — 9,327 73,783 — (80 ) 73,703 Total $ 339,106 $ 130 $ (92 ) $ 339,144 $ 320,480 $ 52 $ (237 ) $ 320,295

Property and Equipment (Tables)

Property and Equipment (Tables)	6 Months Ended
	Jun. 30, 2016
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	Property and equipment (in thousands): As of June 30, 2016 As of December 31, 2015 Flight equipment $ 1,195,320 $ 1,123,115 Computer hardware and software 92,221 78,200 Ground property and equipment 75,098 72,078 Total property and equipment 1,362,639 1,273,393 Less accumulated depreciation and amortization (425,514 ) (387,451 ) Property and equipment, net $ 937,125 $ 885,942

Long-Term Debt (Tables)

Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Summary of Long-Term Debt	Long-term debt (in thousands): As of June 30, 2016 As of December 31, 2015 Fixed-rate notes payable due through 2020 $ 336,889 $ 341,738 Variable-rate notes payable due through 2021 293,832 299,940 Total long-term debt, net of related costs 630,721 641,678 Less current maturities 80,085 74,069 Long-term debt, net of current maturities and related costs $ 550,636 $ 567,609

Long-Term Debt Schedule of Matu

Long-Term Debt Schedule of Maturities of Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2016
Schedule of Maturities of Long-Term Debt [Abstract]
Schedule of Maturities of Long-term Debt	Maturities of long-term debt for the remainder of 2016 and for the next four years and thereafter, in aggregate (in thousands): As of June 30, 2016 Remaining in 2016 $ 39,762 2017 81,378 2018 138,409 2019 342,634 2020 27,034 Thereafter 1,504 Total $ 630,721

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2016
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 $ 9,639 $ 9,639 $ — Commercial paper 1,199 — 1,199 Total cash equivalents 10,838 9,639 1,199 Short-term Commercial paper 129,035 — 129,035 Corporate debt securities 81,087 — 81,087 Municipal debt securities 27,534 — 27,534 US Treasury Bonds 11,749 — 11,749 Federal agency debt securities 6,019 — 6,019 Total short-term 255,424 — 255,424 Long-term US Treasury Bonds 47,410 — 47,410 Corporate debt securities 22,164 — 22,164 Federal agency debt securities 3,308 — 3,308 Derivative instruments 1,816 — 1,816 Total long-term 74,698 — 74,698 Total financial instruments $ 340,960 $ 9,639 $ 331,321 As of Level 1 Level 2 Cash equivalents Commercial paper $ 8,426 $ — $ 8,426 Money market funds 781 781 — Municipal debt securities 754 — 754 Total cash equivalents 9,961 781 9,180 Short-term Corporate debt securities 80,957 — 80,957 Commercial paper 74,728 — 74,728 Municipal debt securities 47,073 — 47,073 Federal agency debt securities 42,825 — 42,825 Total short-term 245,583 — 245,583 Long-term Federal agency debt securities 30,878 — 30,878 Corporate debt securities 27,425 — 27,425 Municipal debt securities 4,843 — 4,843 Derivative instruments 2,480 — 2,480 US Treasury Bonds 1,606 — 1,606 Total long-term 67,232 — 67,232 Total financial instruments $ 322,776 $ 781 $ 321,995
Fair Value, Liabilities Measured on Recurring Basis	Carrying value and estimated fair value of long-term debt, including current maturities and excluding related costs (in thousands): As of June 30, 2016 As of December 31, 2015 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Hierarchy Level Publicly held debt $ 300,000 $ 312,750 $ 300,000 $ 299,250 2 Non-publicly held debt 334,958 314,325 346,179 327,321 3 Total long-term debt $ 634,958 $ 627,075 $ 646,179 $ 626,571

Stockholders' Equity Repurchase

Stockholders' Equity Repurchases (Tables)	6 Months Ended
	Jun. 30, 2016
Equity, Class of Treasury Stock [Line Items]
Treasury Stock [Text Block]	Share repurchases consisted of the following during the periods indicated: Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Shares repurchased (not in thousands) 55,148 178,327 369,997 469,461 Average price per share $139.08 $160.38 $166.70 $173.03 Total (in thousands) $7,670 $28,600 $61,679 $81,232

Earnings per Share (Tables)

Earnings per Share (Tables)	6 Months Ended
	Jun. 30, 2016
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 count and dollar amounts in chart are in thousands): Three Months Ended June 30, Six Months Ended June 30, 2016 2015 2016 2015 Basic: Net income attributable to Allegiant Travel Company $ 60,847 $ 54,339 $ 132,827 $ 119,205 Less net income allocated to participating securities (283 ) (265 ) (663 ) (609 ) Net income attributable to common stock $ 60,564 $ 54,074 $ 132,164 $ 118,596 Net income per share, basic $ 3.69 $ 3.19 $ 8.09 $ 6.95 Weighted-average shares outstanding 16,420 16,954 16,340 17,073 Diluted: Net income attributable to Allegiant Travel Company $ 60,847 $ 54,339 $ 132,827 $ 119,205 Less net income allocated to participating securities (350 ) (265 ) (765 ) (607 ) Net income attributable to common stock $ 60,497 $ 54,074 $ 132,062 $ 118,598 Net income per share, diluted $ 3.68 $ 3.18 $ 8.07 $ 6.93 Weighted-average shares outstanding 16,420 16,954 16,340 17,073 Dilutive effect of stock options, restricted stock and stock-settled stock appreciation rights 36 59 42 71 Adjusted weighted-average shares outstanding under treasury stock method 16,456 17,013 16,382 17,144 Participating securities excluded under two-class method (14 ) (21 ) (17 ) (30 ) Adjusted weighted-average shares outstanding under two-class method 16,442 16,992 16,365 17,114

Commitments and Contingencies C

Commitments and Contingencies Commitments to Purchase (Tables)	6 Months Ended
	Jun. 30, 2016
Commitments to Purchase Aircraft [Abstract]
Long-term Purchase Commitment	As of June 30, 2016 , the Company had firm commitments to purchase the following aircraft: Aircraft Type Number of Aircraft Under Contract Airbus A319 7 Airbus A320 15

Commitments and Contingencies P

Commitments and Contingencies Payments Related to Commitments to Purchase (Tables)	6 Months Ended
	Jun. 30, 2016
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) are as follows: As of June 30, 2016 Remaining in 2016 $ 65,980 2017 135,728 2018 67,367 2019 78,837 2020 42,447 Thereafter 3,361 Total commitments $ 393,720 See Note 13 below concerning commitments entered into subsequent to June 30, 2016.

Investment Securities (Detail)

Investment Securities (Detail) - Investment Securities - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Cost	$ 339,106	$ 320,480
Gross Unrealized Gains	130	52
Gross Unrealized Losses	(92)	(237)
Market Value	339,144	320,295
Commercial paper
Cost	130,256	83,155
Gross Unrealized Gains	35	0
Gross Unrealized Losses	(57)	(1)
Market Value	130,234	83,154
Corporate debt securities
Cost	103,216	108,485
Gross Unrealized Gains	61	50
Gross Unrealized Losses	(26)	(154)
Market Value	103,251	108,381
US Treasury bond
Cost	59,142	1,607
Gross Unrealized Gains	19	0
Gross Unrealized Losses	(2)	(1)
Market Value	59,159	1,606
Municipal debt securities
Cost	27,540	52,669
Gross Unrealized Gains	1	2
Gross Unrealized Losses	(7)	(1)
Market Value	27,534	52,670
Money market funds
Cost	9,639	781
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Market Value	9,639	781
Federal agency debt securities
Cost	9,313	73,783
Gross Unrealized Gains	14	0
Gross Unrealized Losses	0	(80)
Market Value	$ 9,327	$ 73,703

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Flight equipment	$ 1,195,320	$ 1,123,115
Computer Hardware and Software	92,221	78,200
Ground property and equipment	75,098	72,078
Total property and equipment	1,362,639	1,273,393
Less accumulated depreciation and amortization	425,514	387,451
Property and equipment, net	$ 937,125	$ 885,942

Long-Term Debt Long-Term Debt -

Long-Term Debt Long-Term Debt - Components of Long-Term Debt (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Notes Payable	$ 634,958	$ 646,179
Secured Long-term Debt, Noncurrent	630,721	641,678
Less current maturities	80,085	74,069
Long-term debt, net of current maturities and related costs	550,636	567,609
Fixed Rate Notes Payable Through 2020
Debt Instrument [Line Items]
Notes Payable	336,889	341,738
Variable Rate Notes Payable Through 2021 [Domain]
Debt Instrument [Line Items]
Notes Payable	$ 293,832	$ 299,940

Long-Term Debt (Detail)

Long-Term Debt (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Secured Long-term Debt, Noncurrent		$ 630,721	$ 641,678
Debt Instrument, Interest Rate, Stated Percentage	1.75%
Due January 2021
Secured Long-term Debt, Noncurrent	$ 28,000
Airbus A319 | Due January 2021
Debt Instrument, Collateral	2

Long-Term Debt Schedule of Ma33

Long-Term Debt Schedule of Maturities of Long-Term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 39,762
Long-term Debt, Maturities, Repayments of Principal in Year Two	81,378
Long-term Debt, Maturities, Repayments of Principal in Year Three	138,409
Long-term Debt, Maturities, Repayments of Principal in Year Four	342,634
Long-term Debt, Maturities, Repayments of Principal in Year Five	27,034
Long-term Debt, Maturities, Repayments of Principal after Year Five	1,504
Long-term Debt, Fair Value	$ 630,721	$ 641,678

Fair Value Measurements (Detail

Fair Value Measurements (Detail) - Fair Value Measurements at Reporting Date Using - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Investment Securities	$ 339,144	$ 320,295
Fair Value, Measurements, Recurring
Investment Securities	340,960	322,776
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Investment Securities	9,639	781
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Investment Securities	331,321	321,995
Fair Value, Measurements, Recurring | Municipal debt securities
Cash Equivalents		754
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		754
Short-term Investments | Fair Value, Measurements, Recurring
Investment Securities	255,424	245,583
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	255,424	245,583
Short-term Investments | Fair Value, Measurements, Recurring | Commercial paper
Investment Securities	129,035	74,728
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	129,035	74,728
Short-term Investments | Fair Value, Measurements, Recurring | Federal agency debt securities
Investment Securities	6,019	42,825
Short-term Investments | Fair Value, Measurements, Recurring | Federal agency debt securities | Fair Value, Inputs, Level 1
Investment Securities	0	0
Short-term Investments | Fair Value, Measurements, Recurring | Federal agency debt securities | Fair Value, Inputs, Level 2
Investment Securities	6,019	42,825
Short-term Investments | Fair Value, Measurements, Recurring | Municipal debt securities
Investment Securities	27,534	47,073
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	27,534	47,073
Short-term Investments | Fair Value, Measurements, Recurring | Corporate debt securities
Investment Securities	81,087	80,957
Short-term Investments | Fair Value, Measurements, Recurring | Corporate debt securities | Fair Value, Inputs, Level 1
Investment Securities	0	0
Short-term Investments | Fair Value, Measurements, Recurring | Corporate debt securities | Fair Value, Inputs, Level 2
Investment Securities	81,087	80,957
Short-term Investments | Fair Value, Measurements, Recurring | US Treasury Securities
Investment Securities	11,749
Short-term Investments | Fair Value, Measurements, Recurring | US Treasury Securities | Fair Value, Inputs, Level 1
Investment Securities	0
Short-term Investments | Fair Value, Measurements, Recurring | US Treasury Securities | Fair Value, Inputs, Level 2
Investment Securities	11,749
Long Term Investments | Fair Value, Measurements, Recurring
Investment Securities	74,698	67,232
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	74,698	67,232
Long Term Investments | Fair Value, Measurements, Recurring | Federal agency debt securities
Investment Securities	3,308	30,878
Long Term Investments | Fair Value, Measurements, Recurring | Federal agency debt securities | Fair Value, Inputs, Level 1
Investment Securities	0	0
Long Term Investments | Fair Value, Measurements, Recurring | Federal agency debt securities | Fair Value, Inputs, Level 2
Investment Securities	3,308	30,878
Long Term Investments | Fair Value, Measurements, Recurring | Municipal debt securities
Investment Securities		4,843
Long Term Investments | Fair Value, Measurements, Recurring | Municipal debt securities | Fair Value, Inputs, Level 1
Investment Securities		0
Long Term Investments | Fair Value, Measurements, Recurring | Municipal debt securities | Fair Value, Inputs, Level 2
Investment Securities		4,843
Long Term Investments | Fair Value, Measurements, Recurring | Corporate debt securities
Investment Securities	22,164	27,425
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	22,164	27,425
Long Term Investments | Fair Value, Measurements, Recurring | US Treasury Securities
Investment Securities	47,410	1,606
Long Term Investments | Fair Value, Measurements, Recurring | US Treasury Securities | Fair Value, Inputs, Level 1
Investment Securities	0	0
Long Term Investments | Fair Value, Measurements, Recurring | US Treasury Securities | Fair Value, Inputs, Level 2
Investment Securities	47,410	1,606
Long Term Investments | Fair Value, Measurements, Recurring | Derivative Financial Instruments, Assets
Investment Securities	1,816	2,480
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	1,816	2,480
Cash Equivalents [Member] | Fair Value, Measurements, Recurring
Cash Equivalents	10,838	9,961
Cash Equivalents [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Cash Equivalents	9,639	781
Cash Equivalents [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Cash Equivalents	1,199	9,180
Cash Equivalents [Member] | Fair Value, Measurements, Recurring | Money market funds
Cash Equivalents	9,639	781
Cash Equivalents [Member] | Fair Value, Measurements, Recurring | Money market funds | Fair Value, Inputs, Level 1
Cash Equivalents	9,639	781
Cash Equivalents [Member] | Fair Value, Measurements, Recurring | Money market funds | Fair Value, Inputs, Level 2
Cash Equivalents	0	0
Cash Equivalents [Member] | Fair Value, Measurements, Recurring | Commercial paper
Cash Equivalents	1,199	8,426
Cash Equivalents [Member] | Fair Value, Measurements, Recurring | Commercial paper | Fair Value, Inputs, Level 1
Cash Equivalents	0	0
Cash Equivalents [Member] | Fair Value, Measurements, Recurring | Commercial paper | Fair Value, Inputs, Level 2
Cash Equivalents	$ 1,199	$ 8,426

Fair Value Measurements Estimat

Fair Value Measurements Estimated Fair Value of Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Long-term Debt, Noncurrent	$ 630,721	$ 641,678
Notes Payable	634,958	646,179
Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Long-term Debt, Noncurrent	627,075	626,571
Publicly Held Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Long-term Debt, Noncurrent	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	312,750	299,250
Non-Publicly Held Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Long-term Debt, Noncurrent	334,958	346,179
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	$ 314,325	$ 327,321

Derivative Instruments Derivati

Derivative Instruments Derivative Instruments - Textuals (Details) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2016USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2014Aircraft	Jun. 30, 2016USD ($)	Jun. 30, 2015USD ($)	Dec. 31, 2015USD ($)
Derivative [Line Items]
Unrealized Gain (Loss) on Cash Flow Hedging Instruments				$ (325)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	$ 6	$ (454)		(325)	$ 540
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	245	$ 266		510	$ 743
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				617
Derivative, Notional Amount	$ 1,816			$ 1,816		$ 2,500
Airbus A320 Aircraft Series
Derivative [Line Items]
Assets | Aircraft			12

Stockholders' Equity (Detail)

Stockholders' Equity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Stock Repurchased During Period, Shares	55,148	178,327
Treasury Stock, Shares, Acquired			369,997	469,461
Treasury Stock Acquired, Average Cost Per Share	$ 139.08	$ 160.38	$ 166.70	$ 173.03
Stock Repurchased During Period, Value	$ 7,670	$ 28,600	$ 61,679	$ 81,232
Dividends	$ 11,573		$ 16,627
Common Stock, Dividends, Per Share, Cash Paid	$ 0.70		$ 1

Earnings per Share (Detail) - E

Earnings per Share (Detail) - Earnings Per Share - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	20		42
Basic:
Net income attributable to Allegiant Travel Company (in Dollars)	$ 60,847	$ 54,339	$ 132,827	$ 119,205
Less: Net income allocated to participating securities (in Dollars)	(283)	(265)	(663)	(609)
Net income attributable to common stock (in Dollars)	$ 60,564	$ 54,074	$ 132,164	$ 118,596
Net income per share, basic (in Dollars per share)	$ 3.69	$ 3.19	$ 8.09	$ 6.95
Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted	$ (350)	$ (265)	$ (765)	$ (607)
Net Income (Loss) Available to Common Stockholders, Diluted	$ 60,497	$ 54,074	$ 132,062	$ 118,598
Net income per share, diluted (in Dollars per share)	$ 3.68	$ 3.18	$ 8.07	$ 6.93
Weighted-average shares outstanding	16,420	16,954	16,340	17,073
Dilutive effect of stock options, restricted stock and stock-settled stock appreciation rights	36	59	42	71
Adjusted weighted-average shares outstanding under treasury stock method	16,456	17,013	16,382	17,144
Participating securities excluded under two-class method	(14)	(21)	(17)	(30)
Two-Class Method, Weighted Average Number of Shares Outstanding, Diluted	16,442	16,992	16,365	17,114

Commitments and Contingencies (

Commitments and Contingencies (Detail)	Jun. 30, 2016aircraft
Airbus A319
Long-term Purchase Commitment [Line Items]
Number Of Aircraft Committed To Purchase	7
Airbus A320
Long-term Purchase Commitment [Line Items]
Number Of Aircraft Committed To Purchase	15

Commitments and Contingencies40

Commitments and Contingencies Payments Related to Commitments to Purchase (Details) $ in Thousands	Jun. 30, 2016USD ($)
Payments Related to Commitments to Purchase [Abstract]
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	$ 65,980
Unrecorded Unconditional Purchase Obligation, Due within Two Years	135,728
Unrecorded Unconditional Purchase Obligation, Due within Three Years	67,367
Unrecorded Unconditional Purchase Obligation, Due within Four Years	78,837
Unrecorded Unconditional Purchase Obligation, Due within Five Years	42,447
Unrecorded Unconditional Purchase Obligation, Due after Five Years	3,361
Unrecorded Unconditional Purchase Obligation	$ 393,720

Related Party (Details)

Related Party (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2016	Jun. 30, 2016	Jun. 30, 2015
Office Space
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction			$ 991
Lease Termination
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction	$ 1,300
Game Plane, LLC
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction		$ 0	365
Corporate Training
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction		$ 1,400	1,000
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 | GMS Racing, LLC
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction		$ 0	$ 1,500
Chief Executive Officer | Beneficial Owner | Stock Ownership
Related Party Transaction [Line Items]
Related Party, Ownership Percentage		25.00%

Fuel Tax Refunds (Details)

Fuel Tax Refunds (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Accounts receivable	$ 20,041	$ 15,146
Fuel Tax Refunds	5,400
Fuel Tax Refund Receivable
Accounts receivable	$ 2,900

Subsequent Events (Details)

Subsequent Events (Details) $ in Thousands	Jul. 28, 2016USD ($)	Jul. 23, 2016USD ($)	Jul. 26, 2016aircraft	Jun. 30, 2016USD ($)	Dec. 31, 2015USD ($)
Subsequent Event [Line Items]
Secured Long-term Debt, Noncurrent				$ 630,721	$ 641,678
Subsequent Event
Subsequent Event [Line Items]
Number Of Aircraft Committed To Purchase | aircraft			12
Secured Long-term Debt, Noncurrent	$ 42,000
Debt Instrument, Collateral	3
Proceeds from Lines of Credit		$ 50,400