Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Mr. Icahn and affiliates | Investment in funds
Related Party Transaction [Line Items]
Amount of transaction with related party		$ 280
Related party transaction, balance	$ 4,700		$ 5,000
Percentage fair value of investments in Funds that is attributable to Mr. Icahn	50.00%		50.00%
Consolidated VIE | Expense sharing arrangement
Related Party Transaction [Line Items]
Amount of transaction with related party	$ 3	1
Hertz (equity method investee) | Receipts and revenue from related party
Related Party Transaction [Line Items]
Amount of transaction with related party	12	6
Hertz (equity method investee) | Payments to and purchases from related party
Related Party Transaction [Line Items]
Amount of transaction with related party		1
ACF | Payments to and purchases from related party
Related Party Transaction [Line Items]
Amount of transaction with related party		1
Insight Portfolio Group LLC | Buying group operating expenses
Related Party Transaction [Line Items]
Amount of transaction with related party	1	2
767 Leasing | Automotive Segment
Related Party Transaction [Line Items]
Assets at non-consolidated VIE	87		$ 60
Liabilities at non-consolidated VIE	1		1
investment in nonconsolidated VIE	25	$ 5
investment in related parties	$ 86		$ 59