Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 03, 2021
Document Information [Line Items]
Entity Central Index Key	0000866609
Entity Registrant Name	ION GEOPHYSICAL CORP
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2021
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	1-12691
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	22-2286646
Entity Address, Address Line One	2105 CityWest Blvd. Suite 100
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77042-2855
City Area Code	281
Local Phone Number	933-3339
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	IO
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		28,811,207