Employee Retirement Benefits (Details2) (Contribution Plan Benefits)	3 Months Ended
Mar. 31, 2012 Y
Defined Contribution Plan
Employer's matching contribution as percentage of employee contributions	100.00%
The period of enhanced employer matching contributions (in years)	5
Maximum
Defined Contribution Plan
Percentage of employee contributions eligible for employer match	8.00%

The period for which the employer will make enhanced matching contributions for former members of the defined benefit plan.

No definition available.

Name:	htz_DefinedContributionPlanEmployerEnhancedMatchPeriod
Namespace Prefix:	htz_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration