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.

Condensed 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, 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	$ 223	223				223
Other	4	(5)				(5)	9
Net income (loss) for the period	2,406		2,350			2,350	56
Dividends - common shares (company)			(3,505)			(3,505)
Dividends - common shares (NCI)							(43)
Dividends - common shares (total)	(3,548)
Other comprehensive income (loss)	908			782		782	126
Acquisitions, at cost (company)					$ (421)	(421)
Acquisitions, at cost (NCI)							(83)
Acquisitions, at cost (total)	$ (504)
Acquisitions (in shares)	(6)				(6)
Dispositions	$ 4				$ 4	4
Balance at Mar. 31, 2019	$ 198,021	15,476	420,498	(18,782)	(225,970)	191,222	6,799
Balance (in shares) - issued at Mar. 31, 2019	8,019
Balance (in shares) - in treasury at Mar. 31, 2019	(3,788)
Balance (in shares) - outstanding at Mar. 31, 2019	4,231
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
Amortization of stock-based awards	$ 181	181				181
Other	(25)	(182)				(182)	157
Net income (loss) for the period	(770)		(610)			(610)	(160)
Dividends - common shares (company)			(3,719)			(3,719)
Dividends - common shares (NCI)							(45)
Dividends - common shares (total)	(3,764)
Cumulative effect of accounting change	(94)		(93)			(93)	(1)
Other comprehensive income (loss)	(5,358)			(4,846)		(4,846)	(512)
Acquisitions, at cost (company)					$ (305)	(305)
Acquisitions, at cost (NCI)							(63)
Acquisitions, at cost (total)	$ (368)
Acquisitions (in shares)	(6)				(6)
Dispositions	$ 3				$ 3	3
Balance at Mar. 31, 2020	$ 188,743	$ 15,636	$ 416,919	$ (24,339)	$ (226,137)	$ 182,079	$ 6,664
Balance (in shares) - issued at Mar. 31, 2020	8,019
Balance (in shares) - in treasury at Mar. 31, 2020	(3,791)
Balance (in shares) - outstanding at Mar. 31, 2020	4,228