Note 4 - Fair Value: Fair Value Measurements, by Fair Value hierarchy (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Corporate Debt Securities
Investments, Fair Value Disclosure	$ 445,325	$ 391,113
Mutual Funds
Investments, Fair Value Disclosure	10,275,674
US States and Political Subdivisions Debt Securities
Investments, Fair Value Disclosure	187,909,036	166,799,531
Investments, Fair Value Disclosure	198,630,035	167,190,644
Fair Value, Inputs, Level 1 | Corporate Debt Securities
Investments, Fair Value Disclosure	445,325	391,113
Fair Value, Inputs, Level 1 | Mutual Funds
Investments, Fair Value Disclosure	10,275,674
Fair Value, Inputs, Level 1 | US States and Political Subdivisions Debt Securities
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1
Investments, Fair Value Disclosure	10,720,999	391,113
Fair Value, Inputs, Level 2 | Corporate Debt Securities
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 | Mutual Funds
Investments, Fair Value Disclosure	0
Fair Value, Inputs, Level 2 | US States and Political Subdivisions Debt Securities
Investments, Fair Value Disclosure	187,909,036	166,799,531
Fair Value, Inputs, Level 2
Investments, Fair Value Disclosure	187,909,036	166,799,531
Fair Value, Inputs, Level 3 | Corporate Debt Securities
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 | US States and Political Subdivisions Debt Securities
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3
Investments, Fair Value Disclosure	$ 0	$ 0