Document and Entity Information
Sep. 23, 2019
Document and Entity Information [Abstract]  
Document Type 8-K
Document Period End Date Sep. 23, 2019
Entity File Number 001-38373
Entity Registrant Name TRANSOCEAN LTD
Entity Incorporation, State or Country Code V8
Entity Tax Identification Number 98-0599916
Entity Address, Address Line One Turmstrasse 30
Entity Address, City or Town Steinhausen
Entity Address, Postal Zip Code CH-6312
Entity Address, Country CH
City Area Code +41 (41)
Local Phone Number 749-0500
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security Shares
Trading Symbol RIG
Security Exchange Name NYSE
Entity Emerging Growth Company false
Entity Central Index Key 0001451505
Amendment Flag false