Allegiant Travel (ALGT) 10-Q 21 May 20 2020 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - $ / shares	3 Months Ended
	Mar. 31, 2020	May 21, 2020	Dec. 31, 2019
Document and Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	001-33166
Entity Registrant Name	Allegiant Travel Co
Entity Incorporation, State or Country Code	NV
Entity Tax Identification Number	20-4745737
Entity Address, Address Line One	1201 North Town Center Drive
Entity Address, City or Town	Las Vegas,
Entity Address, State or Province	NV
Entity Address, Postal Zip Code	89144
City Area Code	702
Local Phone Number	851-7300
Title of 12(b) Security	Common stock, par value $.001
Trading Symbol	ALGT
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	true
Entity Common Stock, Shares Outstanding		16,200,067
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Entity Central Index Key	0001362468
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001	$ 0.001

Consolidated Balance Sheets (Cu

Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
CURRENT ASSETS
Cash and cash equivalents	$ 138,361	$ 121,888
Restricted cash	15,671	14,897
Short-term investments	314,946	335,928
Accounts receivable	190,108	25,516
Expendable parts, supplies and fuel, net	28,700	28,375
Prepaid expenses and other current assets	43,011	35,617
TOTAL CURRENT ASSETS	730,797	562,221
Property and equipment, net	2,210,721	2,236,808
Long-term investments	11,019	15,542
Deferred major maintenance, net	133,424	129,654
Operating lease right-of-use assets, net	70,260	22,081
Deposits and other assets	35,686	44,497
TOTAL ASSETS:	3,191,907	3,010,803
CURRENT LIABILITIES
Accounts payable	62,460	27,667
Accrued liabilities	154,009	161,693
Air traffic liability	303,835	249,950
Current maturities of long-term debt and finance lease obligations, net of related costs	223,600	173,274
TOTAL CURRENT LIABILITIES	743,904	612,584
Long-term debt and finance lease obligations, net of current maturities and related costs	1,264,389	1,248,579
Deferred income taxes	292,126	232,520
Other noncurrent liabilities	81,585	33,569
TOTAL LIABILITIES:	2,382,004	2,127,252
SHAREHOLDERS' EQUITY
Common stock, par value $.001	23	23
Treasury shares	(651,352)	(617,579)
Additional paid in capital	295,267	289,933
Accumulated other comprehensive income (loss), net	(624)	98
Retained earnings	1,166,589	1,211,076
TOTAL EQUITY:	809,903	883,551
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY:	$ 3,191,907	$ 3,010,803

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
OPERATING REVENUES:
Passenger	$ 378,911	$ 419,977
Third party products	15,976	17,141
Fixed fee contracts	8,919	10,575
Other	5,375	3,929
Total operating revenues	409,181	451,622
OPERATING EXPENSES:
Salary and benefits	112,646	119,411
Aircraft fuel	88,813	99,682
Station operations	40,999	38,965
Depreciation and amortization	43,699	36,182
Maintenance and repairs	21,795	22,824
Sales and marketing	18,455	20,926
Aircraft lease rental	962	0
Other	26,717	22,554
Special charges	172,900	0
Total operating expenses	526,986	360,544
OPERATING INCOME (LOSS)	(117,805)	91,078
OTHER (INCOME) EXPENSES:
Interest expense	18,153	18,083
Capitalized interest	(4,067)	(1,503)
Interest income	(2,311)	(3,201)
Loss on debt extinguishment	1,222	3,677
Other, net	(76)
Other, net		103
Total other expenses	12,921	17,159
INCOME (LOSS) BEFORE INCOME TAXES	(130,726)	73,919
INCOME TAX PROVISION (BENEFIT)	(97,717)	16,795
NET INCOME (LOSS)	$ (33,009)	$ 57,124
Earnings (loss) per share to common shareholders:
Basic	$ (2.08)	$ 3.52
Earnings Per Share, Diluted	$ (2.08)	$ 3.52
Shares used for computation:
Basic	15,952,000	16,011,000
Diluted	15,952,000	16,013,000
Cash dividends declared per share:	$ 0.70	$ 0.70

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
NET INCOME (LOSS)	$ (33,009)	$ 57,124
Other comprehensive income (loss):
Change in available for sale securities, net of tax	(733)	477
Foreign currency translation adjustments	11	(6)
Total other comprehensive income (loss)	(722)	471
TOTAL COMPREHENSIVE INCOME (LOSS)	$ (33,731)	$ 57,595

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity Statement - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Parent	Treasury Stock	Retained Earnings	AOCI Attributable to Parent
Common Stock, Shares, Outstanding		16,183
Common Stock, Value, Issued		$ 23
Additional paid in capital			$ 270,935
Accumulated other comprehensive income (loss), net							$ (661)
Retained Earnings (Accumulated Deficit)						$ 1,025,061
Treasury Stock, Value					$ (605,037)
Stockholders' Equity Attributable to Parent				$ 690,321
StockIssuedDuringPeriodSharesStockOptionsSARsExercised		118
APIC, Share-based Payment Arrangement, Increase for Cost Recognition			5,312	5,312
Treasury Stock, Value, Acquired, Cost Method				(2,279)	(2,279)
Payments of Dividends	$ 11,394			(11,394)		(11,394)
Treasury Stock, Shares, Acquired		(17)
Other Comprehensive Income (Loss), Net of Tax	471			(80)		(551)	471
NET INCOME	57,124			57,124		57,124
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income				(550)		(550)
Common Stock, Shares, Outstanding		16,284
Common Stock, Value, Issued		$ 23
Additional paid in capital			276,247
Accumulated other comprehensive income (loss), net							(190)
Retained Earnings (Accumulated Deficit)						1,069,690
Treasury Stock, Value					(607,316)
Stockholders' Equity Attributable to Parent				738,454
Common Stock, Shares, Outstanding		16,303
Common Stock, Value, Issued	23	$ 23
Additional paid in capital	289,933		289,933
Accumulated other comprehensive income (loss), net	98						98
Retained Earnings (Accumulated Deficit)	1,211,076					1,211,076
Treasury Stock, Value	617,579				(617,579)
Stockholders' Equity Attributable to Parent	883,551			883,551
StockIssuedDuringPeriodSharesStockOptionsSARsExercised		113
APIC, Share-based Payment Arrangement, Increase for Cost Recognition			5,334	5,334
Treasury Stock, Value, Acquired, Cost Method				(33,773)	(33,773)
Payments of Dividends	11,478			(11,478)		(11,478)
Treasury Stock, Shares, Acquired		(217)
Other Comprehensive Income (Loss), Net of Tax	(722)			(722)		0	(722)
NET INCOME	(33,009)			(33,009)		(33,009)
Common Stock, Shares, Outstanding		16,199
Common Stock, Value, Issued	23	$ 23
Additional paid in capital	295,267		$ 295,267
Accumulated other comprehensive income (loss), net	(624)						$ (624)
Retained Earnings (Accumulated Deficit)	1,166,589					$ 1,166,589
Treasury Stock, Value	651,352				$ (651,352)
Stockholders' Equity Attributable to Parent	$ 809,903			$ 809,903

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity Parentheticals - $ / shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Stockholders' Equity [Abstract]
Common Stock, Dividends, Per Share, Declared	$ 0.70	$ 0.70

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Cash Flows [Abstract]
Net income (loss)	$ (33,009)	$ 57,124
Depreciation and amortization	43,699	36,182
Special charges	163,360	0
Other adjustments	67,890	18,916
Air traffic liability	53,885	64,011
Other - net	(189,508)	(16,136)
Net cash provided by operating activities	106,317	160,097
Cash flows from investing activities:
Purchase of investment securities	(105,382)	(68,447)
Proceeds from maturities of investment securities	130,720	124,472
Purchase of property and equipment, including capitalized interest	(134,483)	(122,551)
Other investing activities	2,283	6,973
Net cash used in investing activities	(106,862)	(59,553)
Cash flows from financing activities:
Cash dividends paid to shareholders	(11,478)	(11,394)
Proceeds from the issuance of debt	128,296	494,000
Repurchase of common stock	(33,773)	(2,279)
Principal payments on debt and finance lease obligations	(62,723)	(386,329)
Debt issuance costs	(2,530)	(30,060)
Other financing activities	0	(2,615)
Net cash provided by financing activities	17,792	61,323
NET CHANGE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	17,247	161,867
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH AT BEGINNING OF PERIOD	136,785	95,911
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH AT END OF PERIOD	154,032	257,778
CASH PAYMENTS (RECEIPTS) FOR:
Interest paid, net of amount capitalized	12,031	20,924
Income tax payments (refunds)	22	(4,490)
Right-of-use (ROU) assets acquired	50,218	23,320
Purchases of property and equipment in accrued liabilities	$ 46,452	$ 3,565

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2020
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. The Company's investments in unconsolidated affiliates, which are 50 percent or less owned, are accounted for under the equity or cost method, and are insignificant to the consolidated financial statements. 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 reclassifications have been made to prior year financial statements to conform to classifications used in the current year. 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 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, 2019 and 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. Recent Accounting Pronouncements On June 16, 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments. The standard requires the use of an “expected loss” model on certain types of financial instruments. The standard also amends the impairment model for available-for-sale debt securities and requires estimated credit losses to be recorded as allowances instead of reductions to amortized cost of the securities. The Company adopted this accounting standard prospectively as of January 1, 2020, and it did not have a significant impact on its consolidated financial statements.

COVID-19 (Notes)

COVID-19 (Notes)	3 Months Ended
	Mar. 31, 2020
Unusual or Infrequent Items, or Both [Abstract]
Unusual or Infrequent Items, or Both, Disclosure [Text Block]	Impact of the COVID-19 Pandemic In December 2019, a novel strain of coronavirus (“ COVID-19 ”) was reported in Wuhan, China. The World Health Organization (“ WHO ”) declared COVID-19 a “pandemic” on March 11, 2020 and the U.S. government declared a national state of emergency on March 13, 2020. The U.S. government has implemented enhanced screenings, quarantine requirements and other travel restrictions in connection with the COVID-19 outbreak. U.S. state governments have instituted similar measures, such as “shelter-in-place” requirements, and declared states of emergency. In addition, the U.S. government has strongly recommended “social distancing” measures, including avoiding gathering in groups of more than 10 people and avoiding discretionary travel. Many attractions in the leisure destinations the Company serves, such as Walt Disney World in Orlando, Florida and Las Vegas hotels, have temporarily closed, also impacting travel to these destinations. Government restrictions and consumer fears relating to COVID-19 have impacted flight loads, resulted in unprecedented cancellations of bookings and substantially reduced demand for new bookings. While the Company performed largely as expected in January and February of 2020, a severe reduction in air travel during March 2020 resulted in a 36.0 percent decline in operating revenues for March 2020 as compared to March 2019. To the date of this report, a steep decline in demand has continued throughout the airline industry, and the Company is continuously reevaluating flight schedules based on demand trends. The Coronavirus Aid, Relief and Economic Security Act (the " CARES Act ") was enacted in March 2020, providing support for the airline industry and other businesses and individuals. The Company has taken many actions to mitigate the effects of COVID-19 on its business, as outlined below: Network and Customer Experience • Reduced April capacity by 87.4 percent • Continually evaluating forward schedules to adjust capacity according to demand trends • Waived change and cancellation fees for all customers • Extended expiry on credit vouchers to two years • Offered refunds on all flights canceled by the Company and also on itineraries canceled by customers Cash Outlay Reduction • Suspended all stock buybacks and dividends • Executives have reduced salaries by 50 percent and Board members are foregoing cash compensation • Enacted a hiring freeze and offering voluntary leave – More than 1,100 team members are currently participating in some form of pay reduction program • Suspended nearly all contractor positions, subscriptions, non-essential training and travel • Suspended all non-essential capital expenditures including, but not limited to, Sunseeker Resorts, Teesnap and Allegiant Nonstop family entertainment centers • Extended payment terms and renegotiating contracts with vendors Liquidity Response • Implemented immediate and meaningful cash burn reductions, which is the Company's most effective way to manage liquidity • Received additional financing of $31.0 million in April 2020, secured by two aircraft • As of April 30, 2020 the Company had 28 unencumbered aircraft and eight unencumbered spare engines • In April 2020, signed payroll support agreement with U.S. Department of Treasury (the " Treasury ") in the amount of $171.9 million comprised of $150.3 million in direct grants and a $21.6 million low-interest, unsecured 10 -year loan – Received first installment of $86.0 million in April, with remainder expected over the next three months – The Company will issue warrants to the U.S. Department of the Treasury to purchase 25,898 shares at a strike price of $83.33 per share • Expect to receive federal income tax refunds in 2020 and 2021 of up to $194.0 million related to 2018, 2019, and 2020 net operating loss carrybacks due to the change in loss carryback period under the CARES Act • Submitted application under the Loan Program under CARES Act with the option to access up to $276.0 million secured loan by the end of September 2020 Given the above actions and the Company's assumptions about the future impact of COVID-19 on travel demand, which could be materially different due to the inherent uncertainties of the current operating environment, the Company expects to meet its cash obligations as well as remain in compliance with the debt covenants in its existing financing agreements for the next 12 months based on its current level of unrestricted cash and short-term investments, its anticipated access to liquidity as discussed above, and projected cash flows from operations. Special Charges The effects of COVID-19 triggered an impairment review as of March 31, 2020, and due to the uncertainty of our non-airline activity moving forward a non-cash impairment charge was recognized during the first quarter (see Note 12 for additional detail). The Company also identified expenses that were unique and specific to COVID-19. This includes salary expense, additional aircraft cleaning expense, and other various expenses. See below for a summary of charges by segment: (in thousands) Airline Sunseeker Resort Other non-airline Total COVID-19 related expenses $ 9,540 $ — $ — $ 9,540 Impairment of assets (non-cash) — 136,793 26,567 163,360 Total special charges $ 9,540 $ 136,793 $ 26,567 $ 172,900

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 31, 2020
Revenue Recognition [Abstract]
Revenue from Contract with Customer [Text Block]	Revenue Recognition Passenger Revenue Passenger revenue is the most significant category in our reported operating revenues. Passenger revenue is primarily composed of scheduled service revenue (including passenger ticket sales and credit voucher breakage), revenue from ancillary air-related charges (including seat fees, baggage fees, and other travel-related services performed in conjunction with a passenger’s flight), as well as co-brand credit card point redemptions, as outlined below: Three Months Ended March 31, (in thousands) 2020 2019 Scheduled service $ 197,261 $ 234,772 Ancillary air-related charges 176,964 181,700 Co-brand redemptions 4,686 3,505 Total passenger revenue $ 378,911 $ 419,977 Sales of passenger tickets not yet flown are recorded in air traffic liability. Passenger revenue is recognized when transportation is provided or when ticket voucher breakage occurs, to the extent different from estimated breakage. As of March 31, 2020 , approximately 45 percent of the air traffic liability balance was related to forward bookings, with the remaining 55 percent related to credit vouchers for future travel. The contract term of passenger tickets is twelve months and revenue associated with future travel will principally be recognized within this time frame. During the three months ended March 31, 2020 , $191.6 million was recognized into passenger revenue that was recorded in the air traffic liability balance of $250.0 million at December 31, 2019 . In April 2020, the Company announced that credits issued for canceled travel in April through the end of the COVID-19 pandemic will have an extended expiration date which is two years from the original booking date. This change will be considered in estimating the future breakage rate, which represents the value of credit vouchers that are not expected to be redeemed prior to their contractual expiration date. Co-brand redemptions In relation to the travel component of the co-branded credit card contract with Bank of America, the Company has a performance obligation to provide cardholders with points to be used for future travel award redemptions. Therefore, consideration received from Bank of America related to the travel component is deferred based on its relative selling price and is recognized into passenger revenue when the points are redeemed and the transportation is provided. The following table presents the activity of the co-brand point liability as of the dates indicated: Three Months Ended March 31, (in thousands) 2020 2019 Balance at January 1 $ 15,613 $ 10,708 Points awarded (deferral of revenue) 6,354 4,164 Points redeemed (recognition of revenue) (4,686 ) (3,505 ) Balance at March 31 $ 17,281 $ 11,367 As of March 31, 2020 and 2019 , $12.5 million and $8.9 million , respectively, of the current points liability is reflected in Accrued liabilities and represents the Company's current estimate of revenue to be recognized in the next twelve months based on historical trends, with the remaining balance reflected in other noncurrent liabilities expected to be recognized into revenue in periods thereafter. Given the inherent uncertainty of the current operating environment due to COVID-19, the Company will continue to monitor redemption patterns and may adjust its estimates in the future.

Property and Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment Disclosure	Property and Equipment Property and equipment: (in thousands) March 31, 2020 December 31, 2019 Flight equipment, including pre-delivery deposits $ 2,397,141 $ 2,289,157 Computer hardware and software 153,842 171,516 Land and buildings/leasehold improvements 81,954 98,885 Other property and equipment 80,816 161,760 Total property and equipment 2,713,753 2,721,318 Less accumulated depreciation and amortization (503,032 ) (484,510 ) Property and equipment, net $ 2,210,721 $ 2,236,808 Accrued capital expenditures as of March 31, 2020 and December 31, 2019 were $46.5 million and $16.5 million

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Long-term debt and finance lease obligations: (in thousands) March 31, 2020 December 31, 2019 Fixed-rate debt and finance lease obligations due through 2029 $ 230,531 $ 235,071 Variable-rate debt due through 2029 1,257,458 1,186,782 Total long-term debt and finance lease obligations, net of related costs 1,487,989 1,421,853 Less current maturities, net of related costs 223,600 173,274 Long-term debt and finance lease obligations, net of current maturities and related costs $ 1,264,389 $ 1,248,579 Weighted average fixed-interest rate on debt 3.8 % 3.7 % Weighted average variable-interest rate on debt 3.7 % 4.5 % Maturities of long-term debt and finance lease obligations for the remainder of 2020 and for the next four years and thereafter, in the aggregate, are: remaining in 2020 - $140.9 million ; 2021 - $185.8 million ; 2022 - $117.8 million ; 2023 - $105.0 million ; 2024 - $639.1 million ; and $299.4 million thereafter. Senior Secured Revolving Credit Facility The Company has a senior secured revolving credit facility under which it is able to borrow up to $81.0 million . The facility has a term of 24 months and the borrowing ability is based on the value of the Airbus A320 series aircraft placed in the collateral pool. In 2019 the Company drew down $81.0 million under this facility. Aircraft remain in the collateral pool for up to two years , and, as of March 31, 2020 , there were eight aircraft in the collateral pool. The notes for the amounts borrowed under the facility bear interest at a floating rate based on LIBOR and are due in March 2021. Term Loan In February 2019, the Company entered into a Credit and Guaranty Agreement (the “Term Loan”) to borrow $450.0 million , guaranteed by all of the Company's subsidiaries, excluding Sunseeker Resorts Inc. and its subsidiaries, and other insignificant subsidiaries (the "Term Loan Guarantors"). In February 2020 the Company entered into an amendment to the Term Loan under which the interest rate was reduced by 150 basis points, and the principal amount of the debt was increased by a net amount of $100.0 million to $545.5 million . Quarterly principal payments increased under the amendment, but the remaining provisions were substantially unchanged, including the maturity date. The Term Loan is secured by substantially all property and assets of the Company and the Term Loan Guarantors, excluding aircraft and aircraft engines, and excluding certain other assets. The Term Loan bears interest based on LIBOR and provides for quarterly interest payments along with quarterly principal payments of $1.4 million through February 2024, at which time the Term Loan is due. The Term Loan may be prepaid at any time without penalty.

Income Taxes (Notes)

Income Taxes (Notes)	3 Months Ended
	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes The Company recorded a $97.7 million tax benefit for the three months ended March 31, 2020 , which was 74.7 percent of loss before taxes, compared to a $16.8 million tax provision, or 22.7 percent of income before taxes, for the three months ended March 31, 2019 . The effective tax rate for the three months ended March 31, 2020 differed from the statutory federal income tax rate of 21.0 percent primarily due to the tax accounting impact of the CARES Act which includes a $39.6 million discrete federal income tax benefit related to the full utilization of 2018 and 2019 net operating losses against taxable income in earlier years in which 35.0 percent was the enacted tax rate; the ability to carryback the 2020 net operating loss at a 35.0 percent

Leases (Notes)

Leases (Notes)	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Lessee, Leases [Policy Text Block]	Leases The Company evaluates all operating leases and they are measured on the balance sheet with a lease liability and right-of-use asset (“ROU”) at inception. ROU assets represent the Company’s right to use an underlying asset for the lease term, and lease liabilities represent the obligation to make scheduled lease payments. Airport terminal leases mostly include variable lease payments outside of those based on a fixed index, and are therefore not recorded as ROU assets. (in thousands) Classification on the Balance Sheet March 31, 2020 December 31, 2019 Assets Operating lease assets (1) Operating lease right-of-use assets $ 70,260 $ 22,081 Finance lease assets (2) Property and equipment, net 110,036 111,665 Total lease assets $ 180,296 $ 133,746 Liabilities Current Operating (1) Accrued liabilities $ 5,954 $ 2,662 Finance (2) Current maturities of long-term debt and finance lease obligations 7,750 7,666 Noncurrent Operating (1) Other noncurrent liabilities 66,545 21,290 Finance (2) Long-term debt and finance lease obligations 105,960 107,930 Total lease liabilities $ 186,209 $ 139,548 (1) Represents assets and liabilities of three aircraft, office facilities, office equipment, certain airport and terminal facilities, and other assets under operating lease (2) Represents assets and liabilities of five aircraft under finance lease

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value, Measurement Inputs, Disclosure	Fair Value Measurements The Company utilizes the market approach to measure the fair value of its financial assets. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets. The assets classified as Level 2 primarily utilize quoted market prices or alternative pricing sources including transactions involving identical or comparable assets and models utilizing market observable inputs for valuation of these securities. No changes in valuation techniques or inputs occurred during the three months ended March 31, 2020 . Financial instruments measured at fair value on a recurring basis: March 31, 2020 December 31, 2019 (in thousands) Total Level 1 Level 2 Total Level 1 Level 2 Cash equivalents Money market funds $ 47,774 $ 47,774 $ — $ 42,653 $ 42,653 $ — Commercial paper 7,135 — 7,135 5,807 — 5,807 Municipal debt securities 4,547 — 4,547 1,202 — 1,202 Total cash equivalents 59,456 47,774 11,682 49,662 42,653 7,009 Short-term Corporate debt securities 158,060 — 158,060 145,975 — 145,975 Commercial paper 142,667 — 142,667 161,286 — 161,286 Municipal debt securities 8,678 — 8,678 12,237 — 12,237 US Treasury bonds 3,076 — 3,076 2,915 — 2,915 Federal agency debt securities 2,465 — 2,465 13,515 — 13,515 Total short-term 314,946 — 314,946 335,928 — 335,928 Long-term Federal agency debt securities 11,019 — 11,019 — — — Corporate debt securities — — — 15,396 — 15,396 US Treasury bonds — — — 146 — 146 Total long-term 11,019 — 11,019 15,542 — 15,542 Total financial instruments $ 385,421 $ 47,774 $ 337,647 $ 401,132 $ 42,653 $ 358,479 None of the Company's debt is publicly held and as a result, the Company has determined the estimated fair value of these notes to be Level 3. Certain inputs used to determine fair value 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 without reduction for related costs, are as follows: March 31, 2020 December 31, 2019 (in thousands) Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Hierarchy Level Non-publicly held debt $ 1,397,339 $ 1,235,274 $ 1,329,882 $ 1,140,232 3 Due to their short-term nature, the carrying amounts of cash, cash equivalents, restricted cash, accounts receivable and accounts payable approximate fair value.

Earnings per Share

Earnings per Share	3 Months Ended
	Mar. 31, 2020
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 months ended March 31, 2020 and 2019 , respectively, 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 other than per-share amounts in table are in thousands): Three Months Ended March 31, 2020 2019 Basic: Net income (loss) $ (33,009 ) $ 57,124 Less net income allocated to participating securities (236 ) (799 ) Net income (loss) attributable to common stock $ (33,245 ) $ 56,325 Earnings (loss) per share, basic $ (2.08 ) $ 3.52 Weighted-average shares outstanding 15,952 16,011 Diluted: Net income (loss) $ (33,009 ) $ 57,124 Less net income allocated to participating securities (236 ) (798 ) Net income (loss) attributable to common stock $ (33,245 ) $ 56,326 Earnings (loss) per share, diluted $ (2.08 ) $ 3.52 Weighted-average shares outstanding 15,952 16,011 Dilutive effect of stock options and restricted stock 62 31 Adjusted weighted-average shares outstanding under treasury stock method 16,014 16,042 Participating securities excluded under two-class method (62 ) (29 ) Adjusted weighted-average shares outstanding under two-class method 15,952 16,013

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies As of March 31, 2020 , the Company had commitments to purchase eight Airbus A320 aircraft as well as purchase agreements for four spare engines. The Company's contractual purchase commitments consist primarily of aircraft and engine acquisitions. The total future commitments are as follows: (in thousands) March 31, 2020 Remaining in 2020 $ 126,141 2021 37,900 2022 21,000 Total commitments $ 185,041 Contingencies The Company is subject to certain legal and administrative actions it considers routine to its business activities. The Company believes the ultimate outcome of any potential and pending legal or administrative matters will not have a material adverse impact on its financial position, liquidity or results of operations.

Operating Segments (Notes)

Operating Segments (Notes)	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Segment Reporting Disclosure [Text Block]	Segments Operating segments are components of a company for which separate financial and operating information is regularly evaluated and reported to the Chief Operating Decision Maker ("CODM"), and is used to allocate resources and analyze performance. The Company's CODM is the executive leadership team, which reviews information about the Company's three operating segments: the Airline, Sunseeker Resort, and other non-airline. Airline Segment The Airline segment operates as a single business unit and includes all scheduled service air transportation, ancillary air-related products and services, third party products and services, fixed fee contract air transportation and other airline-related revenue. The CODM evaluation includes, but is not limited to, route and flight profitability data, ancillary and third party product and service offering statistics, and fixed fee contract information when making resource allocation decisions with the goal of optimizing consolidated financial results. Sunseeker Resort Segment The Sunseeker Resort segment represents activity related to the development and construction of Sunseeker Resort in Southwest Florida, as well as the operation of Kingsway golf course. Due to the various impacts of COVID-19, the Company suspended construction of Sunseeker Resort and temporarily closed operation of Kingsway golf course. At this time, it is uncertain when construction will resume and when the golf course will re-open. The Company recognized a $136.8 million non-cash impairment charge related to Sunseeker assets in the first quarter 2020 (refer to Note 12 for additional information). Other non-Airline Segment The other non-airline segment includes the Teesnap golf course management solution and Allegiant Nonstop family entertainment centers. Allegiant Nonstop family entertainment centers are comprised of games, attractions, and food facilities. Due to the impacts of COVID-19, the Company temporarily closed the Allegiant Nonstop location in Warren, MI, and permanently closed the Allegiant Nonstop location in Clearfield, Utah. The Company also permanently discontinued all activity for the Allegiant Nonstop location in West Jordan, Utah, which was being developed. An $18.3 million non-cash impairment charge was recognized in connection with these closures (refer to Note 12 for additional information). In July 2019, management began evaluating strategic alternatives for Teesnap, and its business-to-business software as a service offering. In the first quarter of 2020, the Company recognized a non-cash $8.3 million impairment charge over Teesnap assets (refer to Note 12 for additional information). Teesnap remains an asset held for sale. Selected information for the Company's segments and the reconciliation to the consolidated financial statement amounts are as follows: (in thousands) Airline (1) Sunseeker Resort (2) Other non- airline (3) Consolidated Three Months Ended March 31, 2020 Operating revenue: Passenger $ 378,911 $ — $ — $ 378,911 Third party products 15,976 — — 15,976 Fixed fee contract 8,919 — — 8,919 Other 876 621 3,878 5,375 Operating income (loss) 51,119 (139,235 ) (29,689 ) (117,805 ) Interest expense, net 11,199 576 — 11,775 Depreciation and amortization 42,451 476 772 43,699 Capital expenditures 118,899 45,160 442 164,501 Three Months Ended March 31, 2019 Operating revenue: Passenger $ 419,977 $ — $ — $ 419,977 Third party products 17,141 — — 17,141 Fixed fee contract 10,575 — — 10,575 Other 631 902 2,396 3,929 Operating income (loss) 98,490 (1,222 ) (6,190 ) 91,078 Interest expense, net 13,221 158 — 13,379 Depreciation and amortization 35,229 156 797 36,182 Capital expenditures 108,920 5,275 8,356 122,551 (1) Includes $9.5 million special charge in the first quarter 2020 (2) Includes $136.8 million special charge in the first quarter 2020 (3) Includes $26.6 million special charge in the first quarter 2020 Total assets were as follows as of the dates indicated: (in thousands) March 31, 2020 December 31, 2019 Airline $ 3,132,812 $ 2,830,236 Sunseeker Resort 38,223 133,362 Other non-airline 20,872 47,205 Consolidated $ 3,191,907 $ 3,010,803

Impairment (Notes)

Impairment (Notes)	3 Months Ended
	Mar. 31, 2020
Property, Plant and Equipment [Abstract]
Restructuring, Impairment, and Other Activities Disclosure [Text Block]	Impairment Accounting Standards Codification (ASC) 360 - Property, Plant, and Equipment (ASC 360) requires long-lived assets to be assessed for impairment when events and circumstances indicate that the assets may be impaired. As described in Note 2, in the first quarter of 2020, our operations and liquidity were significantly impacted by decreased passenger demand and U.S. government travel restrictions and quarantine requirements due to COVID-19. As a result of these events and circumstances, the Company performed impairment tests on its long-lived assets in connection with the preparation of its financial statements. In accordance with ASC 360, an impairment of a long-lived asset or group of long-lived assets exists only when the sum of the estimated undiscounted future cash flows expected to be generated directly by the assets are less than the carrying value of the assets. Assets were grouped by operating segment when estimating future cash flows, and further grouped within each segment as applicable. Estimates of future cash flows were generally based on historical results, and management's best estimate of future market and operating conditions. Airline Segment Long-lived assets for the Airline segment consist primarily of owned flight and ground equipment. To test the recoverability of the Company's airline operating fleet, undiscounted future cash flows for each aircraft under the Company's current expected operating fleet plan were assessed and it was determined that there was no impairment as of March 31, 2020. As the Company obtains greater clarity about the duration and extent of reduced demand and potentially executes further capacity adjustments, the Company will continue to evaluate its current fleet compared to network requirements and may decide to permanently retire aircraft. Sunseeker Resort Segment Long-lived assets for Sunseeker Resort and related Kingsway golf course consist primarily of the land, construction in process, building, and other various equipment. As a result of the impairment tests performed, the Company determined the sum of the undiscounted cash flows were less than the long-lived assets' carrying value. A $136.8 million impairment charge was recorded to reflect the difference between the carrying values of these assets and their fair values. Fair value reflects management's best estimate, including valuation inputs from third parties and recent market transactions. Other non-Airline Segment Long-lived assets for Allegiant Nonstop family entertainment centers consist primarily of leasehold improvements, arcade games, various equipment, and ROU assets. As a result of the impairment tests performed, the Company determined the sum of the undiscounted cash flows were less than the long-lived assets' carrying value. An $18.3 million impairment charge was recorded to reflect the difference between the carrying values of these assets and their fair values. Fair value reflects management's best estimate, including valuation inputs from third parties and recent market trends. Long-lived assets for Teesnap consist primarily of capitalized software and computer equipment. As a result of the impairment tests performed, the Company determined the sum of the undiscounted cash flows were less than the long-lived assets' carrying value. Management does not expect to recover any of the book value of the assets through operations, and an $8.3 million impairment charge was recorded to write down all long-lived assets to a net book value of zero . This reflects management's best estimate of the fair value of these assets based on recent market trends.

Subsequent Events (Notes)

Subsequent Events (Notes)	3 Months Ended
	Mar. 31, 2020
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events On April 20, 2020, the Company through its airline operating subsidiary Allegiant Air, LLC entered into a Payroll Support Program Agreement (the “ PSPA ”) with the Treasury for an award Allegiant Air will receive under the CARES Act. The total amount allocated to Allegiant Air under the Payroll Support Program established under the CARES Act is approximately $171.9 million , and is to be received in installments. The Company received the first installment of the grant in April 2020, which totaled $86.0 million . The majority of the remaining support under the PSPA is expected to be received in the second quarter 2020. The proceeds must be used exclusively for wages, salaries and benefits. In consideration for the grant, Allegiant Air issued to Treasury a low-interest rate, senior unsecured term promissory note (the “ PSP Note ”) which, when the full amount of the award is funded, will be in the principal amount of approximately $21.6 million . The PSP Note will mature 10 years after issuance. The PSP Note is guaranteed by the Company and is prepayable at any time at par. Also in consideration for the grant, the Company will issue to Treasury warrants (the “ PSP Warrants ”) to purchase 25,898 shares of common stock of the Company at a price of $83.33 per share (based on the closing price of the Company’s common stock on The Nasdaq Global Select Market on April 9, 2020). The PSP Warrants will expire five years after issuance, and will be exercisable either through net share settlement or cash, at the Company’s option. The PSP Warrants will include customary anti-dilution provisions, will not have any voting rights and will be freely transferable, with registration rights.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies - (Policies)	3 Months Ended
	Mar. 31, 2020
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. The Company's investments in unconsolidated affiliates, which are 50 percent or less owned, are accounted for under the equity or cost method, and are insignificant to the consolidated financial statements. 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 reclassifications have been made to prior year financial statements to conform to classifications used in the current year. 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 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, 2019 and 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.
New Accounting Pronouncements	Recent Accounting Pronouncements On June 16, 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments. The standard requires the use of an “expected loss” model on certain types of financial instruments. The standard also amends the impairment model for available-for-sale debt securities and requires estimated credit losses to be recorded as allowances instead of reductions to amortized cost of the securities. The Company adopted this accounting standard prospectively as of January 1, 2020, and it did not have a significant impact on its consolidated financial statements.

Operating Segments Asset Held f

Operating Segments Asset Held for Sale (Policies)	3 Months Ended
	Mar. 31, 2020
Long Lived Assets Held-for-sale [Line Items]
Disclosure of Long Lived Assets Held-for-sale [Table Text Block]	In July 2019, management began evaluating strategic alternatives for Teesnap, and its business-to-business software as a service offering. In the first quarter of 2020, the Company recognized a non-cash $8.3 million impairment charge over Teesnap assets (refer to Note 12 for additional information). Teesnap remains an asset held for sale.

COVID-19 (Tables)

COVID-19 (Tables)	3 Months Ended
	Mar. 31, 2020
Special Charge [Abstract]
Restructuring and Related Activities Disclosure [Text Block]	Special Charges The effects of COVID-19 triggered an impairment review as of March 31, 2020, and due to the uncertainty of our non-airline activity moving forward a non-cash impairment charge was recognized during the first quarter (see Note 12 for additional detail). The Company also identified expenses that were unique and specific to COVID-19. This includes salary expense, additional aircraft cleaning expense, and other various expenses. See below for a summary of charges by segment: (in thousands) Airline Sunseeker Resort Other non-airline Total COVID-19 related expenses $ 9,540 $ — $ — $ 9,540 Impairment of assets (non-cash) — 136,793 26,567 163,360 Total special charges $ 9,540 $ 136,793 $ 26,567 $ 172,900

Revenue Recognition (Tables)

Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 2020
Revenue Recognition [Abstract]
Disaggregation of Revenue [Table Text Block]	Passenger revenue is primarily composed of scheduled service revenue (including passenger ticket sales and credit voucher breakage), revenue from ancillary air-related charges (including seat fees, baggage fees, and other travel-related services performed in conjunction with a passenger’s flight), as well as co-brand credit card point redemptions, as outlined below: Three Months Ended March 31, (in thousands) 2020 2019 Scheduled service $ 197,261 $ 234,772 Ancillary air-related charges 176,964 181,700 Co-brand redemptions 4,686 3,505 Total passenger revenue $ 378,911 $ 419,977
Contract with Customer, Asset and Liability [Table Text Block]	The following table presents the activity of the co-brand point liability as of the dates indicated: Three Months Ended March 31, (in thousands) 2020 2019 Balance at January 1 $ 15,613 $ 10,708 Points awarded (deferral of revenue) 6,354 4,164 Points redeemed (recognition of revenue) (4,686 ) (3,505 ) Balance at March 31 $ 17,281 $ 11,367

Property and Equipment (Tables)

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2020
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	Property and equipment: (in thousands) March 31, 2020 December 31, 2019 Flight equipment, including pre-delivery deposits $ 2,397,141 $ 2,289,157 Computer hardware and software 153,842 171,516 Land and buildings/leasehold improvements 81,954 98,885 Other property and equipment 80,816 161,760 Total property and equipment 2,713,753 2,721,318 Less accumulated depreciation and amortization (503,032 ) (484,510 ) Property and equipment, net $ 2,210,721 $ 2,236,808

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
Summary of Long-Term Debt	Long-term debt and finance lease obligations: (in thousands) March 31, 2020 December 31, 2019 Fixed-rate debt and finance lease obligations due through 2029 $ 230,531 $ 235,071 Variable-rate debt due through 2029 1,257,458 1,186,782 Total long-term debt and finance lease obligations, net of related costs 1,487,989 1,421,853 Less current maturities, net of related costs 223,600 173,274 Long-term debt and finance lease obligations, net of current maturities and related costs $ 1,264,389 $ 1,248,579 Weighted average fixed-interest rate on debt 3.8 % 3.7 % Weighted average variable-interest rate on debt 3.7 % 4.5 %

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Leases of Lessee Disclosure [Text Block]	(in thousands) Classification on the Balance Sheet March 31, 2020 December 31, 2019 Assets Operating lease assets (1) Operating lease right-of-use assets $ 70,260 $ 22,081 Finance lease assets (2) Property and equipment, net 110,036 111,665 Total lease assets $ 180,296 $ 133,746 Liabilities Current Operating (1) Accrued liabilities $ 5,954 $ 2,662 Finance (2) Current maturities of long-term debt and finance lease obligations 7,750 7,666 Noncurrent Operating (1) Other noncurrent liabilities 66,545 21,290 Finance (2) Long-term debt and finance lease obligations 105,960 107,930 Total lease liabilities $ 186,209 $ 139,548

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Assets Measured at Fair Value On a Recurring Basis	Financial instruments measured at fair value on a recurring basis: March 31, 2020 December 31, 2019 (in thousands) Total Level 1 Level 2 Total Level 1 Level 2 Cash equivalents Money market funds $ 47,774 $ 47,774 $ — $ 42,653 $ 42,653 $ — Commercial paper 7,135 — 7,135 5,807 — 5,807 Municipal debt securities 4,547 — 4,547 1,202 — 1,202 Total cash equivalents 59,456 47,774 11,682 49,662 42,653 7,009 Short-term Corporate debt securities 158,060 — 158,060 145,975 — 145,975 Commercial paper 142,667 — 142,667 161,286 — 161,286 Municipal debt securities 8,678 — 8,678 12,237 — 12,237 US Treasury bonds 3,076 — 3,076 2,915 — 2,915 Federal agency debt securities 2,465 — 2,465 13,515 — 13,515 Total short-term 314,946 — 314,946 335,928 — 335,928 Long-term Federal agency debt securities 11,019 — 11,019 — — — Corporate debt securities — — — 15,396 — 15,396 US Treasury bonds — — — 146 — 146 Total long-term 11,019 — 11,019 15,542 — 15,542 Total financial instruments $ 385,421 $ 47,774 $ 337,647 $ 401,132 $ 42,653 $ 358,479
Fair Value, Liabilities Measured on Recurring Basis	Carrying value and estimated fair value of long-term debt, including current maturities and without reduction for related costs, are as follows: March 31, 2020 December 31, 2019 (in thousands) Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Hierarchy Level Non-publicly held debt $ 1,397,339 $ 1,235,274 $ 1,329,882 $ 1,140,232 3

Earnings per Share (Tables)

Earnings per Share (Tables)	3 Months Ended
	Mar. 31, 2020
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 other than per-share amounts in table are in thousands): Three Months Ended March 31, 2020 2019 Basic: Net income (loss) $ (33,009 ) $ 57,124 Less net income allocated to participating securities (236 ) (799 ) Net income (loss) attributable to common stock $ (33,245 ) $ 56,325 Earnings (loss) per share, basic $ (2.08 ) $ 3.52 Weighted-average shares outstanding 15,952 16,011 Diluted: Net income (loss) $ (33,009 ) $ 57,124 Less net income allocated to participating securities (236 ) (798 ) Net income (loss) attributable to common stock $ (33,245 ) $ 56,326 Earnings (loss) per share, diluted $ (2.08 ) $ 3.52 Weighted-average shares outstanding 15,952 16,011 Dilutive effect of stock options and restricted stock 62 31 Adjusted weighted-average shares outstanding under treasury stock method 16,014 16,042 Participating securities excluded under two-class method (62 ) (29 ) Adjusted weighted-average shares outstanding under two-class method 15,952 16,013

Commitments and Contingencies P

Commitments and Contingencies Payments Related to Commitments to Purchase (Tables)	3 Months Ended
	Mar. 31, 2020
Payments Related to Commitments to Purchase [Abstract]
Long-term Purchase Commitment [Table Text Block]	The Company's contractual purchase commitments consist primarily of aircraft and engine acquisitions. The total future commitments are as follows: (in thousands) March 31, 2020 Remaining in 2020 $ 126,141 2021 37,900 2022 21,000 Total commitments $ 185,041

Operating Segments (Tables)

Operating Segments (Tables)	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Selected information for the Company's segments and the reconciliation to the consolidated financial statement amounts are as follows: (in thousands) Airline (1) Sunseeker Resort (2) Other non- airline (3) Consolidated Three Months Ended March 31, 2020 Operating revenue: Passenger $ 378,911 $ — $ — $ 378,911 Third party products 15,976 — — 15,976 Fixed fee contract 8,919 — — 8,919 Other 876 621 3,878 5,375 Operating income (loss) 51,119 (139,235 ) (29,689 ) (117,805 ) Interest expense, net 11,199 576 — 11,775 Depreciation and amortization 42,451 476 772 43,699 Capital expenditures 118,899 45,160 442 164,501 Three Months Ended March 31, 2019 Operating revenue: Passenger $ 419,977 $ — $ — $ 419,977 Third party products 17,141 — — 17,141 Fixed fee contract 10,575 — — 10,575 Other 631 902 2,396 3,929 Operating income (loss) 98,490 (1,222 ) (6,190 ) 91,078 Interest expense, net 13,221 158 — 13,379 Depreciation and amortization 35,229 156 797 36,182 Capital expenditures 108,920 5,275 8,356 122,551 (1) Includes $9.5 million special charge in the first quarter 2020 (2) Includes $136.8 million special charge in the first quarter 2020 (3) Includes $26.6 million special charge in the first quarter 2020 Total assets were as follows as of the dates indicated: (in thousands) March 31, 2020 December 31, 2019 Airline $ 3,132,812 $ 2,830,236 Sunseeker Resort 38,223 133,362 Other non-airline 20,872 47,205 Consolidated $ 3,191,907 $ 3,010,803

COVID-19 COVID-19 (Details)

COVID-19 COVID-19 (Details)	Apr. 20, 2020USD ($)$ / sharesshares	Apr. 30, 2020Aircraftengine	Mar. 31, 2020	Jun. 30, 2021USD ($)	Apr. 09, 2020$ / shares	Apr. 01, 2020USD ($)	Feb. 13, 2020USD ($)	Feb. 01, 2019USD ($)
Unusual or Infrequent Item, or Both [Line Items]
Debt Instrument, Face Amount							$ 545,500,000	$ 450,000,000
Decrease in Revenue Compared to Prior Year			36.00%
Employee Related Cost Reductions, Percentage, Salary Reduction, Executive Officers			50.00%
Employee Related Cost Reductions, Number Of Employees Volunteering For Leave			1,100
Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Debt Instrument, Face Amount	$ 21,600,000					$ 31,000,000
Flight Capacity Reduction						87.40%
Credit Voucher Term Expiration		2 years
Number Of Aircrafts Included As Collateral | Aircraft		2
Total Expected Receipts of Relief Through Payroll Support Program of CARES Act	171,900,000
Maximum Expected Proceeds From Payroll Support Program, Direct Grant From Treasury	150,300,000
Maximum Expected Proceeds From Payroll Support Program, Low-Interest Loan	$ 21,600,000
Debt Instrument, Term	10 years
Total Amount Of Relief Granted Through Payroll Support Program Of CARES Act	$ 86,000,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares	25,898
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares	$ 83.33				$ 83.33
Expected Tax Refunds From CARES Act				$ 194,000,000
Total Expected Receipts of Relief through Loan Programs of CARES Act	$ 276,000,000
Asset, Aircraft, Unencumbered | Aircraft		28
Asset, Engine, Unencumbered | engine		8

COVID-19 COVID-19 Segment (Deta

COVID-19 COVID-19 Segment (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)
Segment Reporting Information [Line Items]
Operating Special Charges, Net	$ 9,540
Asset Impairment Charges	163,360
Special charge	172,900
Allegiant Air
Segment Reporting Information [Line Items]
Operating Special Charges, Net	9,540
Asset Impairment Charges	0
Special charge	9,540
Sunseeker Resorts
Segment Reporting Information [Line Items]
Asset Impairment Charges	136,793
Special charge	136,793
Other
Segment Reporting Information [Line Items]
Asset Impairment Charges	26,567
Special charge	$ 26,567

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 378,911	$ 419,977
Allegiant Air
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	378,911	419,977
Allegiant Air | Scheduled Service Revenue
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	197,261	234,772
Allegiant Air | Air-related revenue
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	176,964	181,700
Allegiant Air | Co-brand Revenue
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 4,686	$ 3,505

Revenue Recognition Passenger R

Revenue Recognition Passenger Revenue (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Apr. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Subsequent Event [Line Items]
Contract with Customer, Liability, Forward Bookings		45.00%
Contract with Customer, Liability, Credit Voucher Bookings		55.00%
Revenue, Performance Obligation, Description of Timing		P12M
Increase (Decrease) in Revenue from Contract with Customer		$ 191,600
Contract with Customer, Liability, Current		$ 303,835	$ 249,950
Subsequent Event
Subsequent Event [Line Items]
Credit Voucher Term Expiration	2 years

Revenue Recognition Points Liab

Revenue Recognition Points Liability (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Points Liability [Abstract]
Revenue, Performance Obligation, Description of Timing	P12M
Contract with Customer, Liability	$ 17,281	$ 11,367	$ 15,613	$ 10,708
Points awarded	6,354	4,164
Points redeemed	(4,686)	(3,505)
Points Liability	$ 12,500	$ 8,900

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Capital Expenditures Incurred but Not yet Paid	$ 46,500	$ 16,500
Flight equipment, including pre-delivery deposits	2,397,141	2,289,157
Computer hardware and software	153,842	171,516
Land and buildings/leasehold improvements	81,954	98,885
Other property and equipment	80,816	161,760
Total property and equipment	2,713,753	2,721,318
Less accumulated depreciation and amortization	503,032	484,510
Property and equipment, net	$ 2,210,721	$ 2,236,808

Long-Term Debt Components of Lo

Long-Term Debt Components of Long-Term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Secured Long-term Debt, Noncurrent	$ 1,487,989	$ 1,421,853
Less current maturities	223,600	173,274
Long-term debt and capital leases, net of current maturities and related costs	1,264,389	1,248,579
Weighted average fixed-interest rate on debt
Debt Instrument [Line Items]
Notes Payable	$ 230,531	$ 235,071
Long-term Debt, Weighted Average Interest Rate, at Point in Time	3.80%	3.70%
Weighted average variable-interest rate on debt
Debt Instrument [Line Items]
Notes Payable	$ 1,257,458	$ 1,186,782
Long-term Debt, Weighted Average Interest Rate, at Point in Time	3.70%	4.50%

Long-Term Debt (Details)

Long-Term Debt (Details) $ in Thousands	Feb. 13, 2020USD ($)	Feb. 28, 2019USD ($)	Mar. 31, 2020USD ($)Aircraft	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2019USD ($)	Feb. 01, 2019USD ($)
Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year			$ 140,900
Long-term Debt, Maturities, Repayments of Principal in Year Two			185,800
Long-term Debt, Maturities, Repayments of Principal in Year Three			117,800
Long-term Debt, Maturities, Repayments of Principal in Year Four			105,000
Long-term Debt, Maturities, Repayments of Principal in Year Five			639,100
Long-term Debt, Maturities, Repayments of Principal after Year Five			$ 299,400
Line of Credit Facility, Fair Value of Amount Outstanding						$ 81,000
Number of Terms to be Included in the Collateral Pool			2 years
Debt Instrument, Face Amount	$ 545,500						$ 450,000
Debt Instrument, Increase (Decrease), Net	$ 100,000
Gain (Loss) on Extinguishment of Debt			$ 1,222	$ 3,677
Debt Instrument, Periodic Payment, Principal		$ 1,400
Long-term Debt [Member]
reduction in debt interest rate	150.00%
Senior Secured Revolving Credit Facility
Line of Credit Facility, Maximum Borrowing Capacity					$ 81,000
Debt Instrument, Term					24 months
Senior Secured Revolving Credit Facility
Number Of Aircrafts Included As Collateral | Aircraft			8

Long-Term Debt Schedule of Matu

Long-Term Debt Schedule of Maturities of Long-Term Debt (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)Aircraft	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Gain (Loss) on Extinguishment of Debt	$ (1,222)	$ (3,677)
Line of Credit Facility, Fair Value of Amount Outstanding			$ 81,000
Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year	140,900
Long-term Debt, Maturities, Repayments of Principal in Year Two	185,800
Long-term Debt, Maturities, Repayments of Principal in Year Three	117,800
Long-term Debt, Maturities, Repayments of Principal in Year Four	105,000
Long-term Debt, Maturities, Repayments of Principal in Year Five	639,100
Long-term Debt, Maturities, Repayments of Principal after Year Five	$ 299,400
Senior Secured Revolving Credit Facility
Debt Instrument [Line Items]
Number Of Aircrafts Included As Collateral | Aircraft	8

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Tax Expense (Benefit)	$ (97,717)	$ 16,795
Effective Income Tax Rate Reconciliation, Percent	74.70%	22.70%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Discrete Income Tax Expense (Benefit)	$ 39,600
Effective Income Tax Rate Reconciliation,Other Reconciling Items, Percent	35.00%
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent	35.00%

Leases (Details)

Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)Aircraft	Dec. 31, 2019USD ($)
Leases [Abstract]
Operating Leased Assets, Number of Units | Aircraft	3
Finance Leased Assets, Number of Units | Aircraft	5
operating right of use asset, net	$ 70,260	$ 22,081
Finance Lease, Right-of-Use Asset	110,036	111,665
Total Right-of-Use Asset	180,296	133,746
Operating Lease, Liability, Current	5,954	2,662
Finance Lease, Liability, Current	7,750	7,666
Operating Lease, Liability, Noncurrent	66,545	21,290
Finance Lease, Liability, Noncurrent	105,960	107,930
Total Lease Liability	$ 186,209	$ 139,548

Fair Value Measurements (Detail

Fair Value Measurements (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Available-for-sale Securities	$ 385,421	$ 401,132
Fair Value, Inputs, Level 1
Available-for-sale Securities	47,774	42,653
Fair Value, Inputs, Level 2
Available-for-sale Securities	337,647	358,479
Short-term Investments
Available-for-sale Securities	314,946	335,928
Short-term Investments | Fair Value, Inputs, Level 1
Available-for-sale Securities	0	0
Short-term Investments | Fair Value, Inputs, Level 2
Available-for-sale Securities	314,946	335,928
Short-term Investments | Commercial paper
Available-for-sale Securities	142,667	161,286
Short-term Investments | Commercial paper | Fair Value, Inputs, Level 1
Available-for-sale Securities	0	0
Short-term Investments | Commercial paper | Fair Value, Inputs, Level 2
Available-for-sale Securities	142,667	161,286
Short-term Investments | Municipal debt securities
Available-for-sale Securities	8,678	12,237
Short-term Investments | Municipal debt securities | Fair Value, Inputs, Level 1
Available-for-sale Securities	0	0
Short-term Investments | Municipal debt securities | Fair Value, Inputs, Level 2
Available-for-sale Securities	8,678	12,237
Short-term Investments | Federal agency debt securities
Available-for-sale Securities	2,465	13,515
Short-term Investments | Federal agency debt securities | Fair Value, Inputs, Level 1
Available-for-sale Securities	0	0
Short-term Investments | Federal agency debt securities | Fair Value, Inputs, Level 2
Available-for-sale Securities	2,465	13,515
Short-term Investments | Corporate debt securities
Available-for-sale Securities	158,060	145,975
Short-term Investments | Corporate debt securities | Fair Value, Inputs, Level 1
Available-for-sale Securities	0	0
Short-term Investments | Corporate debt securities | Fair Value, Inputs, Level 2
Available-for-sale Securities	158,060	145,975
Short-term Investments | US Treasury Bond Securities
Available-for-sale Securities	3,076	2,915
Short-term Investments | US Treasury Bond Securities | Fair Value, Inputs, Level 1
Available-for-sale Securities	0	0
Short-term Investments | US Treasury Bond Securities | Fair Value, Inputs, Level 2
Available-for-sale Securities	3,076	2,915
Long Term Investments
Available-for-sale Securities	11,019	15,542
Long Term Investments | Fair Value, Inputs, Level 1
Available-for-sale Securities	0	0
Long Term Investments | Fair Value, Inputs, Level 2
Available-for-sale Securities	11,019	15,542
Long Term Investments | Federal agency debt securities
Available-for-sale Securities	11,019	0
Long Term Investments | Federal agency debt securities | Fair Value, Inputs, Level 1
Available-for-sale Securities	0	0
Long Term Investments | Federal agency debt securities | Fair Value, Inputs, Level 2
Available-for-sale Securities	11,019	0
Long Term Investments | Corporate debt securities
Available-for-sale Securities	0	15,396
Long Term Investments | Corporate debt securities | Fair Value, Inputs, Level 1
Available-for-sale Securities	0	0
Long Term Investments | Corporate debt securities | Fair Value, Inputs, Level 2
Available-for-sale Securities	0	15,396
Long Term Investments | US Treasury Bond Securities
Available-for-sale Securities	0	146
Long Term Investments | US Treasury Bond Securities | Fair Value, Inputs, Level 1
Available-for-sale Securities	0	0
Long Term Investments | US Treasury Bond Securities | Fair Value, Inputs, Level 2
Available-for-sale Securities	0	146
Cash Equivalents
Cash Equivalents	59,456	49,662
Cash Equivalents | Fair Value, Inputs, Level 1
Cash Equivalents	47,774	42,653
Cash Equivalents | Fair Value, Inputs, Level 2
Cash Equivalents	11,682	7,009
Cash Equivalents | Money Market Funds
Cash Equivalents	47,774	42,653
Cash Equivalents | Money Market Funds | Fair Value, Inputs, Level 1
Cash Equivalents	47,774	42,653
Cash Equivalents | Money Market Funds | Fair Value, Inputs, Level 2
Cash Equivalents	0	0
Cash Equivalents | Commercial paper
Cash Equivalents	7,135	5,807
Cash Equivalents | Commercial paper | Fair Value, Inputs, Level 1
Cash Equivalents	0	0
Cash Equivalents | Commercial paper | Fair Value, Inputs, Level 2
Cash Equivalents	7,135	5,807
Cash Equivalents | Municipal debt securities
Cash Equivalents	4,547	1,202
Cash Equivalents | Municipal debt securities | Fair Value, Inputs, Level 1
Cash Equivalents	0	0
Cash Equivalents | Municipal debt securities | Fair Value, Inputs, Level 2
Cash Equivalents	$ 4,547	$ 1,202

Fair Value Measurements Estimat

Fair Value Measurements Estimated Fair Value of Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Long-term Debt, Noncurrent	$ 1,487,989	$ 1,421,853
Non-Publicly Held Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Long-term Debt, Noncurrent	1,397,339	1,329,882
Non-Publicly Held Debt | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 1,235,274	$ 1,140,232

Earnings per Share (Details)

Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Basic:
Net income attributable to Allegiant Travel Company (in Dollars)	$ (33,009)	$ 57,124
Less: Net income allocated to participating securities (in Dollars)	(236)	(799)
Net income attributable to common stock (in Dollars)	$ (33,245)	$ 56,325
Net income per share, basic (in Dollars per share)	$ (2.08)	$ 3.52
Weighted-average shares outstanding	15,952,000	16,011,000
Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted	$ (236)	$ (798)
Net Income (Loss) Available to Common Stockholders, Diluted	$ (33,245)	$ 56,326
Diluted earnings per share	$ (2.08)	$ 3.52
Weighted Average Number of Shares Outstanding, Diluted	15,952,000	16,013,000
Dilutive effect of stock options, restricted stock and stock-settled stock appreciation rights	62,000	31,000
Adjusted weighted-average shares outstanding under treasury stock method	16,014,000	16,042,000
Participating securities excluded under two-class method	(62,000)	(29,000)
Two-Class Method, Weighted Average Number of Shares Outstanding, Diluted	15,952,000	16,013,000

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)aircraftengine
Long-term Purchase Commitment [Line Items]
Commitments To Purchase Engine | engine	4
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	$ 126,141
Unrecorded Unconditional Purchase Obligation, Due within Two Years	37,900
Unrecorded Unconditional Purchase Obligation, Due within Three Years	21,000
Unrecorded Unconditional Purchase Obligation	$ 185,041
Airbus A320 Aircraft Series
Long-term Purchase Commitment [Line Items]
Number Of Aircraft Committed To Purchase | aircraft	8

Operating Segments (Details)

Operating Segments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)
Segment Reporting Information [Line Items]
Special charge	$ 172,900
Number of Operating Segments	3
Asset Impairment Charges	$ 163,360
Revenue from Contract with Customer, Excluding Assessed Tax	378,911	$ 419,977
Third party products	15,976	17,141
Fixed fee contracts	8,919	10,575
Other	5,375	3,929
Operating Income (Loss)	(117,805)	91,078
Interest Revenue (Expense), Net	11,775	13,379
Depreciation and amortization	43,699	36,182
Payments to Acquire Productive Assets	164,501	122,551
Assets	3,191,907		$ 3,010,803
Allegiant Air
Segment Reporting Information [Line Items]
Special charge	9,540
Asset Impairment Charges	0
Revenue from Contract with Customer, Excluding Assessed Tax	378,911	419,977
Third party products	15,976	17,141
Fixed fee contracts	8,919	10,575
Other	876	631
Operating Income (Loss)	51,119	98,490
Interest Revenue (Expense), Net	11,199	13,221
Depreciation and amortization	42,451	35,229
Payments to Acquire Productive Assets	118,899	108,920
Assets	3,132,812		2,830,236
Sunseeker Resorts
Segment Reporting Information [Line Items]
Special charge	136,793
Asset Impairment Charges	136,793
Other	621	902
Operating Income (Loss)	(139,235)	(1,222)
Interest Revenue (Expense), Net	576	158
Depreciation and amortization	476	156
Payments to Acquire Productive Assets	45,160	5,275
Assets	38,223		133,362
Other
Segment Reporting Information [Line Items]
Special charge	26,567
Asset Impairment Charges	26,567
Other	3,878	2,396
Operating Income (Loss)	(29,689)	(6,190)
Interest Revenue (Expense), Net	0	0
Depreciation and amortization	772	797
Payments to Acquire Productive Assets	442	$ 8,356
Assets	20,872		$ 47,205
Allegiant Nonstop | Other
Segment Reporting Information [Line Items]
Asset Impairment Charges	18,300
Teesnap | Other
Segment Reporting Information [Line Items]
Asset Impairment Charges	$ 8,300

Impairment (Details)

Impairment (Details)	3 Months Ended
	Mar. 31, 2020USD ($)
Segment Reporting Information [Line Items]
Asset Impairment Charges	$ 163,360,000
Long-Lived Assets	0
Allegiant Air
Segment Reporting Information [Line Items]
Asset Impairment Charges	0
Sunseeker Resorts
Segment Reporting Information [Line Items]
Asset Impairment Charges	136,793,000
Other
Segment Reporting Information [Line Items]
Asset Impairment Charges	26,567,000
Allegiant Nonstop | Other
Segment Reporting Information [Line Items]
Asset Impairment Charges	18,300,000
Teesnap | Other
Segment Reporting Information [Line Items]
Asset Impairment Charges	$ 8,300,000

Subsequent Events (Details)

Subsequent Events (Details) - USD ($)	Apr. 20, 2020	Apr. 09, 2020	Apr. 01, 2020	Feb. 13, 2020	Feb. 01, 2019
Subsequent Event [Line Items]
Debt Instrument, Face Amount				$ 545,500,000	$ 450,000,000
Subsequent Event
Subsequent Event [Line Items]
Warrants and Rights Outstanding, Term	5 years
Total Expected Receipts of Relief Through Payroll Support Program of CARES Act	$ 171,900,000
Total Amount Of Relief Granted Through Payroll Support Program Of CARES Act	86,000,000
Debt Instrument, Face Amount	$ 21,600,000		$ 31,000,000
Debt Instrument, Term	10 years
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	25,898
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 83.33	$ 83.33