Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	DEUTSCHE DWS INSTITUTIONAL FUNDS
Prospectus Date	rr_ProspectusDate	Dec. 21, 2018
Supplement to Prospectus [Text Block]	rr_SupplementToProspectusTextBlock	SUPPLEMENT TO THE CURRENTLY EFFECTIVE SUMMARY PROSPECTUS, STATUTORY PROSPECTUS AND STATEMENT OF ADDITIONAL INFORMATION DWS U.S. Multi-Factor Fund The following disclosure is added to the "Principal Investment Strategy – Main Investments" section of the fund's summary prospectus and summary section of the fund's statutory prospectus, and the "Fund Details" section of the fund's statutory prospectus: While the fund is currently classified as "non-diversified" under the Investment Company Act of 1940, as amended, it may operate as or become classified as "diversified" over time. The fund could again become non-diversified solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the index that the fund is designed to track. Shareholder approval will not be sought when the fund crosses from diversified to non-diversified status under such circumstances. The following disclosure replaces similar disclosure in the "Main Risks" section of the fund's summary prospectus and summary section of the fund's statutory prospectus, and the "Fund Details" section of the fund's statutory prospectus: Non-diversification risk. The fund is classified as non-diversified under the Investment Company Act of 1940, as amended. This means that the fund may invest in securities of relatively few issuers. Thus, the performance of one or a small number of portfolio holdings can affect overall performance. If the fund becomes classified as "diversified" over time and again becomes non-diversified solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the index that the fund is designed to track, non-diversification risk would apply.
DWS US Multi-Factor Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement to Prospectus [Text Block]	rr_SupplementToProspectusTextBlock	SUPPLEMENT TO THE CURRENTLY EFFECTIVE SUMMARY PROSPECTUS, STATUTORY PROSPECTUS AND STATEMENT OF ADDITIONAL INFORMATION DWS U.S. Multi-Factor Fund The following disclosure is added to the "Principal Investment Strategy – Main Investments" section of the fund's summary prospectus and summary section of the fund's statutory prospectus, and the "Fund Details" section of the fund's statutory prospectus: While the fund is currently classified as "non-diversified" under the Investment Company Act of 1940, as amended, it may operate as or become classified as "diversified" over time. The fund could again become non-diversified solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the index that the fund is designed to track. Shareholder approval will not be sought when the fund crosses from diversified to non-diversified status under such circumstances. The following disclosure replaces similar disclosure in the "Main Risks" section of the fund's summary prospectus and summary section of the fund's statutory prospectus, and the "Fund Details" section of the fund's statutory prospectus: Non-diversification risk. The fund is classified as non-diversified under the Investment Company Act of 1940, as amended. This means that the fund may invest in securities of relatively few issuers. Thus, the performance of one or a small number of portfolio holdings can affect overall performance. If the fund becomes classified as "diversified" over time and again becomes non-diversified solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the index that the fund is designed to track, non-diversification risk would apply.
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	While the fund is currently classified as "non-diversified" under the Investment Company Act of 1940, as amended, it may operate as or become classified as "diversified" over time. The fund could again become non-diversified solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the index that the fund is designed to track. Shareholder approval will not be sought when the fund crosses from diversified to non-diversified status under such circumstances.
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	Non-diversification risk. The fund is classified as non-diversified under the Investment Company Act of 1940, as amended. This means that the fund may invest in securities of relatively few issuers. Thus, the performance of one or a small number of portfolio holdings can affect overall performance. If the fund becomes classified as "diversified" over time and again becomes non-diversified solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the index that the fund is designed to track, non-diversification risk would apply.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-diversification risk. The fund is classified as non-diversified under the Investment Company Act of 1940, as amended. This means that the fund may invest in securities of relatively few issuers. Thus, the performance of one or a small number of portfolio holdings can affect overall performance.If the fund becomes classified as "diversified" over time and again becomes non-diversified solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the index that the fund is designed to track, non-diversification risk would apply.

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

DEUTSCHE DWS INSTITUTIONAL FUNDS

Prospectus Date

rr_ProspectusDate

Dec. 21, 2018

Supplement to Prospectus [Text Block]

rr_SupplementToProspectusTextBlock

SUPPLEMENT TO THE CURRENTLY EFFECTIVE SUMMARY PROSPECTUS, STATUTORY PROSPECTUS AND
STATEMENT OF ADDITIONAL INFORMATION

DWS U.S. Multi-Factor Fund

The following disclosure is added to the "Principal Investment Strategy – Main Investments" section of the fund's summary prospectus and summary section of the fund's statutory prospectus, and the "Fund Details" section of the fund's statutory prospectus:

While the fund is currently classified as "non-diversified" under the Investment Company Act of 1940, as amended, it may operate as or become classified as "diversified" over time. The fund could again become non-diversified solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the index that the fund is designed to track. Shareholder approval will not be sought when the fund crosses from diversified to non-diversified status under such circumstances.

The following disclosure replaces similar disclosure in the "Main Risks" section of the fund's summary prospectus and summary section of the fund's statutory prospectus, and the "Fund Details" section of the fund's statutory prospectus:

Non-diversification risk. The fund is classified as non-diversified under the Investment Company Act of 1940, as amended. This means that the fund may invest in securities of relatively few issuers. Thus, the performance of one or a small number of portfolio holdings can affect overall performance.

If the fund becomes classified as "diversified" over time and again becomes non-diversified solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the index that the fund is designed to track, non-diversification risk would apply.

DWS US Multi-Factor Fund

Risk/Return:

rr_RiskReturnAbstract

Supplement to Prospectus [Text Block]

rr_SupplementToProspectusTextBlock

SUPPLEMENT TO THE CURRENTLY EFFECTIVE SUMMARY PROSPECTUS, STATUTORY PROSPECTUS AND
STATEMENT OF ADDITIONAL INFORMATION

DWS U.S. Multi-Factor Fund

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

Non-diversification risk. The fund is classified as non-diversified under the Investment Company Act of 1940, as amended. This means that the fund may invest in securities of relatively few issuers. Thus, the performance of one or a small number of portfolio holdings can affect overall performance.If the fund becomes classified as "diversified" over time and again becomes non-diversified solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the index that the fund is designed to track, non-diversification risk would apply.