N-2
N-2 | 6 Months Ended |
Dec. 31, 2023 | |
Cover [Abstract] | |
Entity Central Index Key | 0001817159 |
Amendment Flag | false |
Entity Inv Company Type | N-2 |
Document Type | N-CSRS |
Entity Registrant Name | RiverNorth Flexible Municipal Income Fund II, Inc. |
Capital Stock, Long-Term Debt, and Other Securities [Abstract] | |
Document Period End Date | Dec. 31, 2023 |