Condensed Balance Sheets By Reporting Segment (Details) - USD ($) $ in Millions	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Cash and cash equivalents	$ 4,008		$ 2,656
Cash held at consolidated affiliated partnerships and restricted cash	664		2,682
Investments	8,858		8,337
Accounts receivable, net	508		474
Inventories, net	1,851		1,779
Property, plant and equipment, net	4,630		4,688
Goodwill and intangible assets, net	742		748
Assets held for sale	400		333
Other assets	2,687		1,792
Assets	24,348		23,489
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	3,934		2,603
Securities sold, not yet purchased, at fair value	146		468
Liabilities held for sale	164		112
Debt	8,658		7,326
Total liabilities	12,902		10,509
Equity attributable to Icahn Enterprises	5,691		6,560
Equity attributable to non-controlling interests	5,755		6,420
Total equity	11,446	$ 11,652	12,980	$ 12,544	$ 11,862	$ 11,486
Liabilities and Equity	24,348		23,489
Investment Segment
ASSETS
Cash and cash equivalents	8		5
Cash held at consolidated affiliated partnerships and restricted cash	651		2,648
Investments	8,191		6,867
Accounts receivable, net	0		0
Inventories, net	0		0
Property, plant and equipment, net	0		0
Goodwill and intangible assets, net	0		0
Assets held for sale	0		0
Other assets	1,508		1,230
Assets	10,358		10,750
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	923		181
Securities sold, not yet purchased, at fair value	146		468
Liabilities held for sale	0		0
Debt	0		0
Total liabilities	1,069		649
Equity attributable to Icahn Enterprises	4,624		5,066
Equity attributable to non-controlling interests	4,665		5,035
Total equity	9,289		10,101
Liabilities and Equity	10,358		10,750
Energy Segment
ASSETS
Cash and cash equivalents	540		668
Cash held at consolidated affiliated partnerships and restricted cash	0		0
Investments	82		84
Accounts receivable, net	168		169
Inventories, net	390		380
Property, plant and equipment, net	2,950		3,027
Goodwill and intangible assets, net	268		278
Assets held for sale	6		33
Other assets	227		192
Assets	4,631		4,831
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	1,076		1,043
Securities sold, not yet purchased, at fair value	0		0
Liabilities held for sale	0		0
Debt	1,195		1,170
Total liabilities	2,271		2,213
Equity attributable to Icahn Enterprises	1,317		1,274
Equity attributable to non-controlling interests	1,043		1,344
Total equity	2,360		2,618
Liabilities and Equity	4,631		4,831
Automotive Segment
ASSETS
Cash and cash equivalents	53		43
Cash held at consolidated affiliated partnerships and restricted cash	0		0
Investments	107		59
Accounts receivable, net	170		149
Inventories, net	1,231		1,203
Property, plant and equipment, net	939		941
Goodwill and intangible assets, net	388		412
Assets held for sale	0		0
Other assets	736		217
Assets	3,624		3,024
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	1,374		905
Securities sold, not yet purchased, at fair value	0		0
Liabilities held for sale	0		0
Debt	406		372
Total liabilities	1,780		1,277
Equity attributable to Icahn Enterprises	1,844		1,747
Equity attributable to non-controlling interests	0		0
Total equity	1,844		1,747
Liabilities and Equity	3,624		3,024
Food Packaging Segment
ASSETS
Cash and cash equivalents	22		46
Cash held at consolidated affiliated partnerships and restricted cash	1		1
Investments	0		0
Accounts receivable, net	82		74
Inventories, net	111		93
Property, plant and equipment, net	166		169
Goodwill and intangible assets, net	31		32
Assets held for sale	0		0
Other assets	134		96
Assets	547		511
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	206		164
Securities sold, not yet purchased, at fair value	0		0
Liabilities held for sale	0		0
Debt	270		273
Total liabilities	476		437
Equity attributable to Icahn Enterprises	54		55
Equity attributable to non-controlling interests	17		19
Total equity	71		74
Liabilities and Equity	547		511
Metals Segment
ASSETS
Cash and cash equivalents	3		20
Cash held at consolidated affiliated partnerships and restricted cash	1		1
Investments	0		0
Accounts receivable, net	44		48
Inventories, net	39		39
Property, plant and equipment, net	124		115
Goodwill and intangible assets, net	14		2
Assets held for sale	1		1
Other assets	20		7
Assets	246		233
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	66		56
Securities sold, not yet purchased, at fair value	0		0
Liabilities held for sale	0		0
Debt	10		0
Total liabilities	76		56
Equity attributable to Icahn Enterprises	170		177
Equity attributable to non-controlling interests	0		0
Total equity	170		177
Liabilities and Equity	246		233
Real Estate Segment
ASSETS
Cash and cash equivalents	41		39
Cash held at consolidated affiliated partnerships and restricted cash	2		26
Investments	15		15
Accounts receivable, net	4		3
Inventories, net	0		0
Property, plant and equipment, net	382		367
Goodwill and intangible assets, net	19		24
Assets held for sale	0		0
Other assets	32		34
Assets	495		508
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	41		41
Securities sold, not yet purchased, at fair value	0		0
Liabilities held for sale	0		0
Debt	2		2
Total liabilities	43		43
Equity attributable to Icahn Enterprises	452		465
Equity attributable to non-controlling interests	0		0
Total equity	452		465
Liabilities and Equity	495		508
Home Fashion Segment
ASSETS
Cash and cash equivalents	4		1
Cash held at consolidated affiliated partnerships and restricted cash	1		2
Investments	0		0
Accounts receivable, net	40		31
Inventories, net	80		64
Property, plant and equipment, net	69		69
Goodwill and intangible assets, net	22		0
Assets held for sale	0		0
Other assets	21		5
Assets	237		172
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	62		35
Securities sold, not yet purchased, at fair value	0		0
Liabilities held for sale	0		0
Debt	20		4
Total liabilities	82		39
Equity attributable to Icahn Enterprises	155		133
Equity attributable to non-controlling interests	0		0
Total equity	155		133
Liabilities and Equity	237		172
Mining Segment
ASSETS
Cash and cash equivalents	0		0
Cash held at consolidated affiliated partnerships and restricted cash	0		0
Investments	0		0
Accounts receivable, net	0		0
Inventories, net	0		0
Property, plant and equipment, net	0		0
Goodwill and intangible assets, net	0		0
Assets held for sale	393		299
Other assets	0		0
Assets	393		299
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	0		0
Securities sold, not yet purchased, at fair value	0		0
Liabilities held for sale	164		112
Debt	0		0
Total liabilities	164		112
Equity attributable to Icahn Enterprises	199		165
Equity attributable to non-controlling interests	30		22
Total equity	229		187
Liabilities and Equity	393		299
Holding Company
ASSETS
Cash and cash equivalents	3,337		1,834
Cash held at consolidated affiliated partnerships and restricted cash	8		4
Investments	463		1,312
Accounts receivable, net	0		0
Inventories, net	0		0
Property, plant and equipment, net	0		0
Goodwill and intangible assets, net	0		0
Assets held for sale	0		0
Other assets	9		11
Assets	3,817		3,161
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	186		178
Securities sold, not yet purchased, at fair value	0		0
Liabilities held for sale	0		0
Debt	6,755		5,505
Total liabilities	6,941		5,683
Equity attributable to Icahn Enterprises	(3,124)		(2,522)
Equity attributable to non-controlling interests	0		0
Total equity	(3,124)		(2,522)
Liabilities and Equity	$ 3,817		$ 3,161