v3.26.1
Segments - Schedule of Segment Reporting Information, by Segment (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Segment Reporting [Line Items]          
Passenger $ 822,491 $ 617,908 $ 1,494,290 $ 1,234,658  
Third party products 45,758 33,649 88,093 68,852  
Fixed fee contracts 45,723 17,019 63,846 33,271  
Cargo 27,586 0 27,586 0  
Other 1,932 20,808 2,106 51,677  
Total operating revenues 943,490 689,384 1,675,921 1,388,458  
Salaries and benefits 250,318 214,102 468,403 445,541  
Aircraft fuel 307,669 165,752 487,910 332,085  
Station operations 95,551 75,248 172,033 148,753  
Depreciation and amortization 70,709 68,519 128,635 131,830  
Maintenance and repairs 49,252 36,379 84,469 71,233  
Sales and marketing 35,194 26,837 63,394 51,933  
Aircraft rent 7,015 11,023 14,476 16,942  
Other 40,716 41,089 60,649 76,259  
Special charges, net of recoveries 65,952 117,924 93,734 116,369  
Total operating expenses 922,376 756,873 1,573,703 1,390,945  
OPERATING INCOME (LOSS) 21,114 (67,489) 102,218 (2,487)  
Interest income (8,840) (10,359) (17,554) 22,294  
Interest expense 40,072 35,756 69,299 76,540  
Capitalized interest (4,937) (4,562) (9,227) (11,050)  
Other non-operating expense 39 240 (1,105) 941  
INCOME (LOSS) BEFORE INCOME TAXES (5,220) (88,564) 60,805 (46,624)  
Segment Reporting, Long-Lived Asset, Expenditure for Addition 188,130 138,753 364,070 222,295  
Assets 6,444,465   6,444,465   $ 4,209,401
Scheduled Service | Operating Segments          
Segment Reporting [Line Items]          
Passenger 411,461   749,760    
Ancillary Air-related Charges | Operating Segments          
Segment Reporting [Line Items]          
Passenger 390,538   703,188    
Loyalty Redemptions | Operating Segments          
Segment Reporting [Line Items]          
Passenger 20,492   41,342    
Allegiant Air          
Segment Reporting [Line Items]          
Passenger   617,908   1,234,658  
Third party products 44,483 33,649 86,818 68,852  
Fixed fee contracts 14,523 17,019 32,646 33,271  
Cargo 0   0    
Other 185 174 359 355  
Total operating revenues 776,207 668,750 1,508,638 1,337,136  
Salaries and benefits 201,337 203,485 419,422 423,859  
Aircraft fuel 265,123 165,752 445,364 332,085  
Station operations 76,139 75,248 152,621 148,753  
Depreciation and amortization 58,521 64,961 116,447 124,672  
Maintenance and repairs 39,349 36,379 74,566 71,233  
Sales and marketing 29,860 25,119 58,060 48,489  
Aircraft rent 7,015 11,023 14,476 16,942  
Other 29,263 29,031 49,196 51,107  
Special charges, net of recoveries 39,514 14,595 67,296 15,987  
Total operating expenses 746,121 625,593 1,397,448 1,233,127  
OPERATING INCOME (LOSS) 30,086 43,157 111,190 104,009  
Interest income (8,093) (10,359) (16,807) 22,294  
Interest expense 35,200 28,121 64,427 57,070  
Capitalized interest (4,937) (4,562) (9,227) (11,050)  
Other non-operating expense 74 240 (1,070) 941  
INCOME (LOSS) BEFORE INCOME TAXES 7,842 29,717 73,867 79,342  
Segment Reporting, Long-Lived Asset, Expenditure for Addition 183,243 137,717 359,183 220,853  
Assets 4,524,180   4,524,180   4,209,401
Allegiant Air | Scheduled Service | Operating Segments          
Segment Reporting [Line Items]          
Passenger 347,853   686,152    
Allegiant Air | Ancillary Air-related Charges | Operating Segments          
Segment Reporting [Line Items]          
Passenger 349,365   662,015    
Allegiant Air | Loyalty Redemptions | Operating Segments          
Segment Reporting [Line Items]          
Passenger 19,798   40,648    
Sun Country Airlines          
Segment Reporting [Line Items]          
Third party products 1,275        
Fixed fee contracts 31,200        
Cargo 27,586        
Other 1,747        
Total operating revenues 167,283        
Salaries and benefits 48,981        
Aircraft fuel 42,546        
Station operations 19,412        
Depreciation and amortization 12,188        
Maintenance and repairs 9,903        
Sales and marketing 5,334        
Aircraft rent 0        
Other 11,453        
Special charges, net of recoveries 26,438        
Total operating expenses 176,255        
OPERATING INCOME (LOSS) (8,972)        
Interest income (747)        
Interest expense 4,872        
Capitalized interest 0        
Other non-operating expense (35)        
INCOME (LOSS) BEFORE INCOME TAXES (13,062)        
Segment Reporting, Long-Lived Asset, Expenditure for Addition 4,887        
Assets 1,920,285   1,920,285   $ 0
Sun Country Airlines | Scheduled Service | Operating Segments          
Segment Reporting [Line Items]          
Passenger 63,608   63,608    
Sun Country Airlines | Ancillary Air-related Charges | Operating Segments          
Segment Reporting [Line Items]          
Passenger 41,173   41,173    
Sun Country Airlines | Loyalty Redemptions | Operating Segments          
Segment Reporting [Line Items]          
Passenger $ 694   694    
Sunseeker          
Segment Reporting [Line Items]          
Passenger   0   0  
Third party products   0 1,275 0  
Fixed fee contracts   0 31,200 0  
Cargo     27,586    
Other   20,634 1,747 51,322  
Total operating revenues   20,634 167,283 51,322  
Salaries and benefits   10,617 48,981 21,682  
Aircraft fuel   0 42,546 0  
Station operations   0 19,412 0  
Depreciation and amortization   3,558 12,188 7,158  
Maintenance and repairs   0 9,903 0  
Sales and marketing   1,718 5,334 3,444  
Aircraft rent   0 0 0  
Other   12,058 11,453 25,152  
Special charges, net of recoveries   103,329 26,438 100,382  
Total operating expenses   131,280 176,255 157,818  
OPERATING INCOME (LOSS)   (110,646) (8,972) (106,496)  
Interest income   0 (747) 0  
Interest expense   7,635 4,872 19,470  
Capitalized interest   0 0 0  
Other non-operating expense   0 (35) 0  
INCOME (LOSS) BEFORE INCOME TAXES   (118,281) (13,062) (125,966)  
Segment Reporting, Long-Lived Asset, Expenditure for Addition   $ 1,036 $ 4,887 $ 1,442