Shareholder Report, Average Annual Return (Details)	12 Months Ended	60 Months Ended	120 Months Ended
	Mar. 31, 2026	Mar. 31, 2026	Mar. 31, 2026
C000015153 [Member]
Average Annual Return [Line Items]
Line Graph and Table Measure Name	Class I Shares at NAV
Average Annual Return, Percent	3.02%	1.46%	1.52%
C000015152 [Member]
Average Annual Return [Line Items]
Line Graph and Table Measure Name	Class A Shares at maximum sales charge (Offering Price)
Average Annual Return, Percent	0.19%	0.73%	1.05%
Without Sales Load [Member] | C000137682 [Member]
Average Annual Return [Line Items]
Line Graph and Table Measure Name	Class C Shares at NAV (excluding maximum sales charge)
Average Annual Return, Percent	1.98%	0.45%	0.65%
Without Sales Load [Member] | C000015152 [Member]
Average Annual Return [Line Items]
Line Graph and Table Measure Name	Class A Shares at NAV (excluding maximum sales charge)
Average Annual Return, Percent	2.74%	1.24%	1.30%
S And P Municipal Bond Index [Member]
Average Annual Return [Line Items]
Line Graph and Table Measure Name	S&P Municipal Bond Index
Average Annual Return, Percent	4.32%	1.08%	2.25%
Lipper Short Municipal Debt Funds Classification Average [Member]
Average Annual Return [Line Items]
Line Graph and Table Measure Name	Lipper Short Municipal Debt Funds Classification Average
Average Annual Return, Percent	3.24%	1.65%	1.47%
S And P Municipal Bond Short Index [Member]
Average Annual Return [Line Items]
Line Graph and Table Measure Name	S&P Municipal Bond Short Index
Average Annual Return, Percent	3.08%	1.64%	1.65%