DWS Intermediate Tax-Free Fund S000006133 [Member] Class ACIS [Member] Class A C000016867 [Member] Class C C000016870 [Member] INST Class C000016872 [Member] Class S C000016871 [Member] Return Before Taxes[Member] Bloomberg Municipal Bond Index (reflects no deduction for fees, expenses or taxes)[Member] Bloomberg Municipal Bond 1-15 Year Blend (1-17) Index (reflects no deduction for fees, expenses or taxes)[Member] Risk Municipal Securities [Member] Risk Interest Rate [Member] Risk Credit [Member] Risk Focus [Member] Risk Market [Member] Risk Security Selection [Member] Risk Tax [Member] Risk Market Disruption [Member] Risk Inflation [Member] Risk Liquidity [Member] Risk Prepayment [Member] Risk Pricing [Member] Risk Forward Commitment [Member] Risk Counterparty [Member] Risk Operational And Technology [Member]