Note 5 - Qualified Affordable Housing Partnership Investments - Original Investment in LIHTC Projects (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Original Investment	$ 8,954		$ 7,954
Current Recorded Investment	3,098		2,529
Unfunded Liability Obligation	1,325		338
Tax Credits and Benefits	461	$ 417
Amortization of Investments	431	397
Net Income Tax Benefit	30	20
Raymond James California Housing Opportunities Fund II [Member]
Original Investment	2,000		2,000
Current Recorded Investment	717		852
Unfunded Liability Obligation	22		22
Tax Credits and Benefits	149	150
Amortization of Investments	135	135
Net Income Tax Benefit	14	15
WNC Institutional Tax Credit Fun 38 L.P. [Member]
Original Investment	1,000		1,000
Current Recorded Investment	335		400
Unfunded Liability Obligation	0		0
Tax Credits and Benefits	78	81
Amortization of Investments	65	68
Net Income Tax Benefit	13	13
Merritt Community Capital Corporation Fund XV, L.P. [Member]
Original Investment	2,500		2,500
Current Recorded Investment	903		1,067
Unfunded Liability Obligation	316		316
Tax Credits and Benefits	167	168
Amortization of Investments	164	165
Net Income Tax Benefit	3	3
California Affordable Housing Fund [Member]
Original Investment	2,454		2,454
Current Recorded Investment	181		210
Unfunded Liability Obligation	0		$ 0
Tax Credits and Benefits	18	18
Amortization of Investments	29	29
Net Income Tax Benefit	(11)	$ (11)
Boston Capital [Member]
Original Investment	1,000
Current Recorded Investment	962
Unfunded Liability Obligation	987
Tax Credits and Benefits	49
Amortization of Investments	38
Net Income Tax Benefit	$ 11