Label	Element	Value
Advisor Class \| Transportation [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	18.20%
Advisor Class \| Health Care [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	16.10%
Advisor Class \| Housing [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	13.40%
Advisor Class \| Industrial Dev. Revenue and Pollution Control [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	10.50%
Advisor Class \| Utilities [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	9.10%
Advisor Class \| Special Tax [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	8.10%
Advisor Class \| Local [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	7.50%
Advisor Class \| Education [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	6.70%
Advisor Class \| Lease [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	5.80%
Advisor Class \| State General Obligation [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	2.40%
Advisor Class \| Refunded [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	1.70%
Advisor Class \| Other Revenue Bonds [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Total Investments	oef_PctOfTotalInv	0.50%