v3.26.1
Document and Entity Information
Jun. 23, 2026
Cover [Abstract]  
Amendment Flag false
Entity Central Index Key 0001190935
Document Type 8-K
Document Period End Date Jun. 23, 2026
Entity Registrant Name PIMCO Corporate & Income Opportunity Fund
Entity Incorporation State Country Code MA
Entity File Number 811-21238
Entity Tax Identification Number 46-6121513
Entity Address, Address Line One 1633 Broadway
Entity Address, City or Town New York
Entity Address, State or Province NY
Entity Address, Postal Zip Code 10019
City Area Code (844)
Local Phone Number 337-4626
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Security 12b Title Common shares
Trading Symbol PTY
Security Exchange Name NYSE
Entity Emerging Growth Company false