Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

Natixis Funds Trust II

Prospectus Date

rr_ProspectusDate

May 01, 2016

Supplement [Text Block]

nftii_SupplementTextBlock

ASG TACTICAL U.S. MARKET FUND

Supplement dated August 29, 2016 to the Prospectus and Statement of Additional Information of the ASG Tactical U.S. Market Fund (the "Fund"), each dated May 1, 2016, as may be revised and supplemented from time to time.

Active Investment Advisors, the division of NGAM Advisors, L.P. that is responsible for managing the equity securities portion of the Fund, changed its name to Active Index Advisors^SM on August 29, 2016. Accordingly, effective immediately, each reference to Active Investment Advisors in the Fund's Prospectus and Statement of Additional Information is replaced with Active Index Advisors^SM.

ASG Tactical U.S. Market Fund

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

nftii_SupplementTextBlock

ASG TACTICAL U.S. MARKET FUND

Supplement dated August 29, 2016 to the Prospectus and Statement of Additional Information of the ASG Tactical U.S. Market Fund (the "Fund"), each dated May 1, 2016, as may be revised and supplemented from time to time.

Active Investment Advisors, the division of NGAM Advisors, L.P. that is responsible for managing the equity securities portion of the Fund, changed its name to Active Index Advisors^SM on August 29, 2016. Accordingly, effective immediately, each reference to Active Investment Advisors in the Fund's Prospectus and Statement of Additional Information is replaced with Active Index Advisors^SM.