v3.25.2
Form N-CSR Cover
6 Months Ended
Jun. 30, 2025
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name Fidelity Central Investment Portfolios II LLC
Entity Central Index Key 0001401097
Entity Investment Company Type N-1A
Document Period End Date Jun. 30, 2025