Note 4 - Loans/Leases Receivable (Details)		12 Months Ended
		Dec. 31, 2019 USD ($) lease loan item	Dec. 31, 2018 USD ($) contract lease loan item	Dec. 31, 2017 USD ($)
Number of Leases | lease		6
Loss related to unguaranteed residual values of leases		$ 0	$ 0	$ 0
Loans and leases		3,681,346,000	3,723,630,000
Loans receivable held for sale		3,673,000	1,295,000
Nonaccrual Loans/Leases		7,902,000	14,260,000
Accruing TDRs		$ 1,700,000	$ 6,500,000
Nonaccrual Loans/Leases | loan		15	14
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 1,093,000	$ 4,123,000
Financing Receivable, Modifications, Subsequent Default, Number of Contracts		2	5
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 66,000	$ 399,000
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down		$ 52,000	$ 896,000
Number of TDRs restructured and written off | item		1	13
Threshold for Related Party Loans Evaluated		$ 60,000
Accruing Past Due 90 Days or More		$ 33,000	$ 632,000
Nonaccrual [Member]
Nonaccrual Loans/Leases		3	3
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 121,000	$ 796,000
Troubled Debt Restructurings [Member]
Nonaccrual Loans/Leases		747,000	2,300,000
Accruing Past Due 90 Days or More			496,000
m2 Lease Funds, LLC [Member]
Loans and leases		142,000,000	103,400,000
Residential Portfolio Segment [Member]
Loans and leases	[1]	239,904,000	290,759,000
Loans Receivable Held-for-sale, Amount		3,700,000	1,300,000
Nonaccrual Loans/Leases		706,000	1,743,000
Accruing Past Due 90 Days or More			89,000
Residential Portfolio Segment [Member] | Troubled Debt Restructurings [Member]
Nonaccrual Loans/Leases		31,000	344,000
Commercial Portfolio Segment [Member]
Loans and leases		1,507,825,000	1,429,410,000
Nonaccrual Loans/Leases		1,236,000	4,088,000
Accruing Past Due 90 Days or More			389,000
Commercial Portfolio Segment [Member] | Troubled Debt Restructurings [Member]
Nonaccrual Loans/Leases		98,000	265,000
Accruing Past Due 90 Days or More			389,000
Commercial Real Estate Portfolio Segment [Member]
Loans and leases		1,736,396,000	1,766,111,000
Commercial Real Estate Portfolio Segment [Member] | Troubled Debt Restructurings [Member]
Nonaccrual Loans/Leases		269,000	1,400,000
Accruing Past Due 90 Days or More			107,000
Finance Leases Portfolio Segment [Member]
Loans and leases		87,869,000	117,969,000
Nonaccrual Loans/Leases		1,517,000	1,761,000
Finance Leases Portfolio Segment [Member] | Troubled Debt Restructurings [Member]
Nonaccrual Loans/Leases		294,000	321,000
Consumer Portfolio Segment [Member]
Loans and leases		109,352,000	119,381,000
Nonaccrual Loans/Leases		556,000	611,000
Accruing Past Due 90 Days or More		33,000	$ 47,000
Consumer Portfolio Segment [Member] | Troubled Debt Restructurings [Member]
Nonaccrual Loans/Leases		55,000
Nonaccrual Loans/Leases			3,000
No Lease End Option Rider [Member]
Number of Leases | lease			9
Lease residual values		$ 547,000	$ 828,000

[1] Includes residential real estate loans held for sale totaling $3.7 million and $1.3 million as of December 31, 2019 and 2018, respectively.