v3.26.1
Form N-1A Cover
Jun. 25, 2026
Prospectus [Line Items]  
Document Type 485BPOS
Amendment Flag false
Registrant Name AIM Investment Securities Funds (Invesco Investment Securities Funds)
Entity Central Index Key 0000842790
Entity Investment Company Type N-1A
Document Period End Date Jun. 25, 2026
Prospectus Date Jun. 26, 2026