Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Other income (loss), net	$ 19	$ 0	$ (22)
Equity earnings from non-consolidated affiliates
Related Party Transaction [Line Items]
Other income (loss), net	21	7	1
Investment in funds \| Mr. Icahn and affiliates
Related Party Transaction [Line Items]
Amount of transaction with related party	$ 220	$ 310	600
Percentage fair value of investments in Funds that is attributable to Mr. Icahn	51.00%	50.00%
Noncontrolling Interest in Variable Interest Entity	$ 4,500	$ 5,000
Expense sharing arrangement \| Consolidated VIE
Related Party Transaction [Line Items]
Amount of transaction with related party	23	12	13
Repair services revenue from related party \| Hertz
Related Party Transaction [Line Items]
Amount of transaction with related party	54	40	17
Purchases from related party \| Hertz
Related Party Transaction [Line Items]
Amount of transaction with related party		1	2
Purchases from related party \| ACF
Related Party Transaction [Line Items]
Amount of transaction with related party		3	6
Sales to related party \| ACF
Related Party Transaction [Line Items]
Amount of transaction with related party		6	1
Buying group operating expenses \| Insight Portfolio Group LLC
Related Party Transaction [Line Items]
Amount of transaction with related party	3	4	2
Automotive Segment
Related Party Transaction [Line Items]
Other income (loss), net	15	(1)	0
Automotive Segment \| 767 Leasing
Related Party Transaction [Line Items]
Variable Interest Entity, Nonconsolidated, assets at VIE	121	59
Variable Interest Entity, Nonconsolidated, liabilities at VIE	1	1
Contribution to non-consolidated VIE	50	60
Equity investment in non-consolidated VIE	120	59
Automotive Segment \| 767 Leasing \| Equity earnings from non-consolidated affiliates
Related Party Transaction [Line Items]
Other income (loss), net	11	(1)
Investment Segment
Related Party Transaction [Line Items]
Other income (loss), net	$ (5)	(2)	$ (50)
Investment Segment \| Purchases from related party \| Hertz
Related Party Transaction [Line Items]
Amount of transaction with related party		$ 36

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