Outstanding Common Stock Equivalents That Were Anti-Dilutive Tickmarks (Detail) - $ / shares	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Anti-dilutive Non-Vested Stock Weighted Average Grant Date Fair Value	$ 52.07	$ 61.15

Anti-dilutive Non-Vested Stock Weighted Average Grant Date Fair Value

No definition available.

Name:	car_AntidilutiveNonVestedStockWeightedAverageGrantDateFairValue
Namespace Prefix:	car_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration