XML 16 R1.htm IDEA: XBRL DOCUMENT v3.20.4
Document And Entity Information - USD ($)
 12 Months Ended
Dec. 31, 2020
Feb. 28, 2021
Jun. 30, 2020
Document Information [Line Items]      
Entity Central Index Key 0000098222    
Entity Registrant Name TIDEWATER INC    
Amendment Flag false    
Current Fiscal Year End Date --12-31    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2020    
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2020    
Document Transition Report false    
Entity File Number 1-6311    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 72-0487776    
Entity Address, Address Line One 6002 Rogerdale Road, Suite 600    
Entity Address, City or Town Houston    
Entity Address, State or Province TX    
Entity Address, Postal Zip Code 77072    
City Area Code 713    
Local Phone Number 470-5300    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Public Float     $ 224,000,000.0
Entity Common Stock, Shares Outstanding   40,715,611  
Warrants to Purchase Shares of Common Stock [Member]      
Document Information [Line Items]      
Title of 12(b) Security Warrants to purchase shares of common stock    
Trading Symbol TDW.WS    
Security Exchange Name NYSEAMER    
Series B Warrants [Member]      
Document Information [Line Items]      
Title of 12(b) Security Series B Warrants to purchase shares of common stock    
Trading Symbol TDW.WS.B    
Security Exchange Name NYSE    
Series A Warrants [Member]      
Document Information [Line Items]      
Title of 12(b) Security Series A Warrants to purchase shares of common stock    
Trading Symbol TDW.WS.A    
Security Exchange Name NYSE    
Preferred Stock Purchase Rights [Member]      
Document Information [Line Items]      
Title of 12(b) Security Preferred stock purchase rights    
Trading Symbol N/A    
Security Exchange Name NYSE    
Common Stock [Member]      
Document Information [Line Items]      
Title of 12(b) Security Common Stock, $0.001 par value per share    
Trading Symbol TDW    
Security Exchange Name NYSE