Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

Name:	us-gaap_CommonStockSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

Consolidated Statement Of Changes In Equity - USD ($) shares in Millions, $ in Millions	Total	ExxonMobil Share Of Common Stock [Member]	ExxonMobil Share Of Earnings Reinvested [Member]	ExxonMobil Share Of Accumulated Other Comprehensive Income [Member]	ExxonMobil Share Of Common Stock Held In Treasury [Member]	ExxonMobil Share Of Equity [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2016	$ 173,830	$ 12,157	$ 407,831	$ (22,239)	$ (230,424)	$ 167,325	$ 6,505
Balance (in shares) - issued at Dec. 31, 2016	8,019
Balance (in shares) - in treasury at Dec. 31, 2016	(3,871)
Balance (in shares) - outstanding at Dec. 31, 2016	4,148
Amortization of stock-based awards	$ 801	801				801
Other	(432)	(380)				(380)	(52)
Net income for the year	19,848		19,710			19,710	138
Dividends - common shares (company)			(13,001)			(13,001)
Dividends - common shares (NCI)							(184)
Dividends - common shares (total)	(13,185)
Other comprehensive income	6,532			5,977		5,977	555
Acquisitions, at cost (company)					(828)	(828)
Acquisitions, at cost (NCI)							(150)
Acquisitions, at cost (total)	(978)
Issued for acquisitions	7,789	2,078			5,711	7,789
Dispositions	$ 295				295	295
Acquisitions (in shares)	(10)
Issued for acquisitions (in shares)	96
Dispositions (in shares)	5
Balance at Dec. 31, 2017	$ 194,500	14,656	414,540	(16,262)	(225,246)	187,688	6,812
Balance (in shares) - issued at Dec. 31, 2017	8,019
Balance (in shares) - in treasury at Dec. 31, 2017	(3,780)
Balance (in shares) - outstanding at Dec. 31, 2017	4,239
Amortization of stock-based awards	$ 758	758				758
Other	280	(156)				(156)	436
Net income for the year	21,421		20,840			20,840	581
Dividends - common shares (company)			(13,798)			(13,798)
Dividends - common shares (NCI)							(243)
Dividends - common shares (total)	(14,041)
Cumulative effect of accounting change	47		71	(39)		32	15
Other comprehensive income	(3,670)			(3,263)		(3,263)	(407)
Acquisitions, at cost (company)					(626)	(626)
Acquisitions, at cost (NCI)							(460)
Acquisitions, at cost (total)	(1,086)
Dispositions	$ 319				319	319
Acquisitions (in shares)	(8)
Dispositions (in shares)	6
Balance at Dec. 31, 2018	$ 198,528	15,258	421,653	(19,564)	(225,553)	191,794	6,734
Balance (in shares) - issued at Dec. 31, 2018	8,019
Balance (in shares) - in treasury at Dec. 31, 2018	(3,782)
Balance (in shares) - outstanding at Dec. 31, 2018	4,237
Amortization of stock-based awards	$ 697	697				697
Other	171	(318)				(318)	489
Net income for the year	14,774		14,340			14,340	434
Dividends - common shares (company)			(14,652)			(14,652)
Dividends - common shares (NCI)							(192)
Dividends - common shares (total)	(14,844)
Other comprehensive income	225			71		71	154
Acquisitions, at cost (company)					(594)	(594)
Acquisitions, at cost (NCI)							(331)
Acquisitions, at cost (total)	(925)
Dispositions	$ 312				312	312
Acquisitions (in shares)	(8)
Dispositions (in shares)	5
Balance at Dec. 31, 2019	$ 198,938	$ 15,637	$ 421,341	$ (19,493)	$ (225,835)	$ 191,650	$ 7,288
Balance (in shares) - issued at Dec. 31, 2019	8,019
Balance (in shares) - in treasury at Dec. 31, 2019	(3,785)
Balance (in shares) - outstanding at Dec. 31, 2019	4,234