Schedule I Condensed Financial Information of Parent - Statements of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income (loss)	$ 1,182	$ (147)	$ 588	$ 423	$ 197	$ 829	$ 1,725	$ (160)	$ 2,046	$ 2,591	$ (2,220)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Net loss (gain) from securities transactions									476	(2,273)	(266)
Gain on disposition of assets, net									84	2,163	6
Other, net									123	(27)	58
Net cash used in operating activities									915	(1,428)	1,218
Other, net									(51)	(76)	(25)
Net cash provided by investing activities									2,590	413	(1,845)
Partnership contributions									0	612	1
Proceeds from other borrowings									1,268	1,334	1,908
Repayments of borrowings									(1,346)	(1,430)	(1,923)
Net cash (used in) provided by financing activities									(152)	718	58
Net change in cash and cash equivalents and restricted cash and restricted cash equivalents									3,427	27	(734)
Cash and cash equivalents and restricted cash and restricted cash equivalents	5,338				1,911				5,338	1,911	1,884	$ 2,618
Icahn Enterprises (Parent)
Net income (loss)									1,507	2,430	(1,128)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Amortization of deferred financing costs									1	1	1
Loss on extinguishment of debt, non-cash									0	(2)	0
Equity in (income) loss of subsidiary									(1,844)	(2,765)	839
Net cash used in operating activities									(336)	(332)	(288)
Net investment in subsidiaries									433	(204)	390
Net cash provided by investing activities									433	(204)	390
Partnership distributions									(97)	(81)	(103)
Partnership contributions									0	606	1
Proceeds from other borrowings									0	2,470	0
Repayments of borrowings									0	(2,450)	0
Debt issuance costs									0	(9)	0
Net cash (used in) provided by financing activities									(97)	536	(102)
Net change in cash and cash equivalents and restricted cash and restricted cash equivalents									0	0	0
Cash and cash equivalents and restricted cash and restricted cash equivalents	0				0				0	0	0	0
Icahn Enterprises Holdings (Parent)
Net income (loss)									1,508	2,432	(1,127)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Net loss (gain) from securities transactions									389	0	(1)
Equity in (income) loss of subsidiary									(2,225)	(2,739)	818
Gain on disposition of assets, net									(23)	1	0
Depreciation and amortization									2	3	3
Other, net									(2)	(39)	8
Change in operating assets and liabilities									8	18	(6)
Net cash used in operating activities									(343)	(324)	(305)
Net investment in subsidiaries									238	509	421
Other, net									41	53	0
Net cash provided by investing activities									279	562	421
Partnership distributions									(97)	(81)	(103)
Partnership contributions									0	6	1
Proceeds from other borrowings									0	2,470	0
Repayments of borrowings									(21)	(2,450)	0
Debt issuance costs									0	(7)	0
Net cash (used in) provided by financing activities									(118)	(62)	(102)
Net change in cash and cash equivalents and restricted cash and restricted cash equivalents									(182)	176	14
Cash and cash equivalents and restricted cash and restricted cash equivalents	$ 59				$ 241				$ 59	$ 241	$ 65	$ 51