Acquistions and Divestitures (Assets Acquired Liabilities Assumed) (Details) - USD ($) $ in Millions	Nov. 19, 2012	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012
Acquisition
Goodwill		$ 1,359	$ 1,349	$ 1,353	$ 1,353	$ 1,352	$ 1,363	$ 1,363	$ 1,346	$ 1,333
Dollar Thrifty
Acquisition
Cash and cash equivalents	$ 535
Restricted cash and cash equivalents	307
Receivables	170
Inventories	8
Prepaid expenses and other assets	41
Revenue earning equipment	1,614
Property and equipment	119
Other intangible assets	1,545
Other assets	35
Goodwill	889
Accounts payable	(43)
Accrued liabilities	(298)
Deferred taxes on income	(846)
Debt	(1,484)
Total	$ 2,592