Average Annual Total Returns		12 Months Ended	60 Months Ended	107 Months Ended	120 Months Ended	208 Months Ended	297 Months Ended		470 Months Ended
Average Annual Total Returns	Sep. 30, 2026	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025
Class A
Prospectus [Line Items]
Average Annual Return, Percent		(0.19%)	0.15%		1.86%				4.73%
Performance Inception Date	Oct. 28, 1986
Class C
Prospectus [Line Items]
Average Annual Return, Percent		1.93%	0.15%		1.63%		3.45%
Performance Inception Date	Mar. 19, 2001
Class F-1
Prospectus [Line Items]
Average Annual Return, Percent		3.60%	0.82%		2.14%			3.61%
Performance Inception Date	Mar. 20, 2001
Class F-2
Prospectus [Line Items]
Average Annual Return, Percent		3.88%	1.10%		2.42%	3.83%
Performance Inception Date	Aug. 22, 2008
Class F-2 \| After Taxes on Distributions
Prospectus [Line Items]
Average Annual Return, Percent		3.88%	1.08%		2.38%
Class F-2 \| After Taxes on Distributions and Sales
Prospectus [Line Items]
Average Annual Return, Percent		3.61%	1.46%		2.51%
Class F-3
Prospectus [Line Items]
Average Annual Return, Percent		3.98%	1.19%	2.78%
Performance Inception Date	Jan. 27, 2017
Bloomberg Municipal Bond Index (reflects no deductions for sales charges, account fees, expenses or U.S. federal income taxes)
Prospectus [Line Items]
Average Annual Return, Percent		4.25%	0.80%		2.34%	3.50%
Bloomberg California Municipal Index (reflects no deductions for sales charges, account fees, expenses or U.S. federal income taxes)
Prospectus [Line Items]
Average Annual Return, Percent		4.11%	0.76%		2.29%	3.72%