Note 11 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred Tax Assets
Loan loss allowance, due to differences in computation of bad debts	$ 37,567	$ 37,157
Share-based compensation	3,260	2,630
Non-accrual interest	2,277	2,100
Write-down on equity securities and venture capital investments	2,095	2,561
Depreciation and amortization	3,798	1,564
State tax	4,344	6,783
Unrealized loss on interest rate swaps	190	1,158
Unrealized loss on securities available-for-sale, net	3,864	198
Unrealized loss on equity securities	843
Basis difference in acquired assets	622	1,676
Tax credits carried forward	9,473	9,278
Net operating loss carried forward	17,163	18,375
Other, net	4,095	4,291
Gross deferred tax assets	89,591	87,771
Deferred Tax Liabilities
Deferred loan costs	(8,839)	(7,655)
Dividends on Federal Home Loan Bank common stock	(956)	(1,021)
Other, net	(4,008)	(3,758)
Gross deferred tax liabilities	(13,803)	(12,434)
Net deferred tax assets	$ 75,788	$ 75,337