Note 3 - Recent Accounting Pronouncements (Details Textual) - USD ($) $ in Thousands	Jun. 30, 2021	Jan. 01, 2021	Dec. 31, 2020
Retained Earnings (Accumulated Deficit), Ending Balance	$ 1,887,571		$ 1,789,325
Loans and Leases Receivable, Allowance, Ending Balance	131,256		166,538
Off-Balance Sheet, Credit Loss, Liability, Ending Balance			5,880
Deferred Tax Assets, Net of Valuation Allowance, Total			$ 85,610
Revision of Prior Period, Error Correction, Adjustment [Member] | Correction of Balance Sheet Amounts [Member]
Retained Earnings (Accumulated Deficit), Ending Balance	$ (2,300)	$ (2,300)
Loans and Leases Receivable, Allowance, Ending Balance		(2,200)
Off-Balance Sheet, Credit Loss, Liability, Ending Balance		5,500
Deferred Tax Assets, Net of Valuation Allowance, Total		1,000
Accounting Standards Update 2016-13 [Member]
Retained Earnings (Accumulated Deficit), Ending Balance		3,100
Loans and Leases Receivable, Allowance, Ending Balance		1,600
Off-Balance Sheet, Credit Loss, Liability, Ending Balance		$ 6,000