Net Assets Investment Company, Portfolio Turnover C000032818 [Member] COLORADO BONDSHARES A TAX-EXEMPT FUND - HICOX Investment Type [Axis] CASH & OTHER ASSETS / LIABILITIES [Member] CHARTER SCHOOLS [Member] CO METRO DISTRICT [Member] HOUSING [Member] INDIAN TRIBE [Member] OTHER [Member] PUERTO RICO [Member] SHORT-TERM [Member] UTAH PID [Member] AAA / Aaa [Member] AA / Aa [Member] A / A [Member] BB / Ba [Member] BBB / Baa [Member] B / B [Member] NOT RATED [Member]