| Label                                                   | **Element**              | Value                                                                                                                                                                                                               |
|---------------------------------------------------------|--------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| **Risk/Return:**                                        | rr_RiskReturnAbstract    |                                                                                                                                                                                                                |
| Registrant Name                                         | dei_EntityRegistrantName | Fidelity Rutland Square Trust II                                                                                                                                                                                    |
| Prospectus Date                                         | rr_ProspectusDate        | Jul. 30,  2015                                                                                                                                                                                                      |
| Strategic | Strategic Advisers Value Multi-Manager Fund |                          |                                                                                                                                                                                                                |
| **Risk/Return:**                                        | rr_RiskReturnAbstract    |                                                                                                                                                                                                                |
| Supplement [Text Block]                                 | frst_SupplementTextBlock | **Supplement to the Strategic Advisers® Value Multi-Manager Fund July 30, 2015 Prospectus***Effective October 1, 2015, the fund changed its classification from a non-diversified fund to a diversified fund.* |

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The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.
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The date of the prospectus.
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| X                                                                                                                                 |
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