v3.26.1
Form N-1A Cover
Apr. 30, 2026
Prospectus [Line Items]  
Document Type 485BPOS
Amendment Flag false
Registrant Name COLUMBIA FUNDS SERIES TRUST I
Entity Central Index Key 0000773757
Entity Investment Company Type N-1A
Document Period End Date Apr. 30, 2026
Prospectus Date Sep. 01, 2026