    <SEC-DOCUMENT>0001362468-22-000002-index.html : 20220106
    <SEC-HEADER>0001362468-22-000002.hdr.sgml : 20220106
    <ACCEPTANCE-DATETIME>20220106112632
    ACCESSION NUMBER:		0001362468-22-000002
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		33
    CONFORMED PERIOD OF REPORT:	20211231
    ITEM INFORMATION:		Entry into a Material Definitive Agreement
    ITEM INFORMATION:		Regulation FD Disclosure
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20220106
    DATE AS OF CHANGE:		20220106

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			Allegiant Travel CO
    		CENTRAL INDEX KEY:			0001362468
    		STANDARD INDUSTRIAL CLASSIFICATION:	AIR TRANSPORTATION, SCHEDULED [4512]
    		IRS NUMBER:				204745737
    		STATE OF INCORPORATION:			NV
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-33166
    		FILM NUMBER:		22514058

    	BUSINESS ADDRESS:
    		STREET 1:		1201 N. TOWN CENTER DRIVE
    		CITY:			LAS VEGAS
    		STATE:			NV
    		ZIP:			89144
    		BUSINESS PHONE:		702-851-7300

    	MAIL ADDRESS:
    		STREET 1:		1201 N. TOWN CENTER DRIVE
    		CITY:			LAS VEGAS
    		STATE:			NV
    		ZIP:			89144
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>8-K
    <SEQUENCE>1
    <FILENAME>algt-20211231.htm
    <DESCRIPTION>8-K
    <TEXT>
    Document 1 - file: algt-20211231.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.1
    <SEQUENCE>2
    <FILENAME>a1622fleetdeckvfinal.htm
    <DESCRIPTION>EX-99.1
    <TEXT>
    Document 2 - file: a1622fleetdeckvfinal.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.SCH
    <SEQUENCE>3
    <FILENAME>algt-20211231.xsd
    <DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA DOCUMENT
    <TEXT>
    Document 3 - file: algt-20211231.xsd

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.LAB
    <SEQUENCE>4
    <FILENAME>algt-20211231_lab.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION LABEL LINKBASE DOCUMENT
    <TEXT>
    Document 4 - file: algt-20211231_lab.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.PRE
    <SEQUENCE>5
    <FILENAME>algt-20211231_pre.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE DOCUMENT
    <TEXT>
    Document 5 - file: algt-20211231_pre.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>a1622fleetdeckvfinal001.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 6 - file: a1622fleetdeckvfinal001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>a1622fleetdeckvfinal002.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: a1622fleetdeckvfinal002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>a1622fleetdeckvfinal003.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 8 - file: a1622fleetdeckvfinal003.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>a1622fleetdeckvfinal004.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 9 - file: a1622fleetdeckvfinal004.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>a1622fleetdeckvfinal005.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: a1622fleetdeckvfinal005.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>a1622fleetdeckvfinal006.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: a1622fleetdeckvfinal006.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>a1622fleetdeckvfinal007.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 12 - file: a1622fleetdeckvfinal007.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>a1622fleetdeckvfinal008.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 13 - file: a1622fleetdeckvfinal008.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>a1622fleetdeckvfinal009.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 14 - file: a1622fleetdeckvfinal009.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>a1622fleetdeckvfinal010.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 15 - file: a1622fleetdeckvfinal010.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>16
    <FILENAME>a1622fleetdeckvfinal011.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 16 - file: a1622fleetdeckvfinal011.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>17
    <FILENAME>a1622fleetdeckvfinal012.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 17 - file: a1622fleetdeckvfinal012.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>18
    <FILENAME>a1622fleetdeckvfinal013.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 18 - file: a1622fleetdeckvfinal013.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>19
    <FILENAME>a1622fleetdeckvfinal014.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 19 - file: a1622fleetdeckvfinal014.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>20
    <FILENAME>a1622fleetdeckvfinal015.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 20 - file: a1622fleetdeckvfinal015.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>21
    <FILENAME>a1622fleetdeckvfinal016.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 21 - file: a1622fleetdeckvfinal016.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>22
    <FILENAME>a1622fleetdeckvfinal017.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 22 - file: a1622fleetdeckvfinal017.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>23
    <FILENAME>a1622fleetdeckvfinal018.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 23 - file: a1622fleetdeckvfinal018.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>24
    <FILENAME>a1622fleetdeckvfinal019.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 24 - file: a1622fleetdeckvfinal019.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>25
    <FILENAME>algt-20211231_g1.jpg
    <TEXT>
    Document 25 - file: algt-20211231_g1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>26
    <FILENAME>R1.htm
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 26 - file: R1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>27
    <FILENAME>algt-20211231_htm.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 27 - file: algt-20211231_htm.html

    Document 27 - RAW XML: algt-20211231_htm.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EXCEL
    <SEQUENCE>28
    <FILENAME>Financial_Report.xlsx
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 28 - file: Financial_Report.xlsx

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>29
    <FILENAME>Show.js
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 29 - file: Show.js

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>30
    <FILENAME>report.css
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 30 - file: report.css

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>31
    <FILENAME>FilingSummary.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 31 - file: FilingSummary.html

    Document 31 - RAW XML: FilingSummary.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>JSON
    <SEQUENCE>34
    <FILENAME>MetaLinks.json
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 34 - file: MetaLinks.json

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>ZIP
    <SEQUENCE>35
    <FILENAME>0001362468-22-000002-xbrl.zip
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 35 - file: 0001362468-22-000002-xbrl.zip

    </DOCUMENT>
    </SEC-DOCUMENT>