Note 8 - Earnings per Share (Detail) - Earnings Per Share (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Basic:
Net income attributable to Allegiant Travel Company (in Dollars)	$ 31,932	$ 21,703
Net income attributable to common stock (in Dollars)	31,718	21,544
Net income per share, diluted (in Dollars per share)	$ 1.65	$ 1.12
Net income attributable to common stock (in Dollars)	31,716	21,542
Net income per share, basic (in Dollars per share)	$ 1.66	$ 1.13
Weighted-average shares outstanding	19,081	18,989
Dilutive effect of stock options, restricted stock and stock-settled stock appreciation rights	172	246
Adjusted weighted-average shares outstanding under treasury stock method	19,253	19,235
Participating securities excluded under two-class method	(46)	(35)
Adjusted weighted-average shares outstanding under two-class method	19,207	19,200
Basic [Member]
Basic:
Less: Net income allocated to participating securities (in Dollars)	(216)	(161)
Diluted [Member]
Basic:
Less: Net income allocated to participating securities (in Dollars)	$ (214)	$ (159)