Tangible Asset Impairments and Asset Write-downs (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Jun. 30, 2014
Business Relationship
Revenue Earning Equipment [Line Items]
Asset impairment charges				$ 10
Held-for-sale | Selling, general and administrative expenses
Revenue Earning Equipment [Line Items]
Asset impairment charges			$ 13
Held-for-sale | Selling, general and administrative expenses | Dollar Thrifty Headquarters
Revenue Earning Equipment [Line Items]
Asset impairment charges		$ 6
Held-for-sale | Other (income) expenses
Revenue Earning Equipment [Line Items]
Asset impairment charges	$ 5	3
Assets deemed to have no future use | Customer contracts | Equipment
Revenue Earning Equipment [Line Items]
Asset impairment charges		11
Assets deemed to have no future use | Customer contracts | Direct operating | Equipment
Revenue Earning Equipment [Line Items]
Asset impairment charges		4
Assets deemed to have no future use | Customer contracts | Other (income) expenses | Equipment
Revenue Earning Equipment [Line Items]
Asset impairment charges		$ 7