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Note 13 - Fair Value Measurements and Fair Value of Financial Instruments - Financial Assets and Liabilities Measured on a Non-recurring Basis (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2021 | Mar. 31, 2020 | Dec. 31, 2020 | Dec. 31, 2019
Assets, fair value disclosure |  | $ 936,359 |  | $ 1,068,382 |
Fair Value, Nonrecurring [Member] |  |  |  |  |
Assets, fair value disclosure |  | 31,522 |  | 41,920 |
Total Losses |  | 71 | $ 369 | 7,836 | $ 848
Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  | 25,287 |  | 35,398 |
Total Losses |  | 0 | 0 | 7,012 | 0
Fair Value, Nonrecurring [Member] | Other Real Estate Owned [Member] |  |  |  |  |
Assets, fair value disclosure | [1] | 5,141 |  | 5,141 |
Total Losses | [1] | 0 | 336 | 717 | 681
Fair Value, Nonrecurring [Member] | Investments in Venture Capital and Private Company Stock [Member] |  |  |  |  |
Assets, fair value disclosure |  | 1,094 |  | 1,381 |
Total Losses |  | 71 | 33 | 107 | 167
Fair Value, Inputs, Level 1 [Member] |  |  |  |  |
Assets, fair value disclosure |  | 61,713 |  | 104,692 |
Fair Value, Inputs, Level 1 [Member] | Fair Value, Nonrecurring [Member] |  |  |  |  |
Assets, fair value disclosure |  | 0 |  | 0 |
Fair Value, Inputs, Level 1 [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  | 0 |  | 0 |
Fair Value, Inputs, Level 1 [Member] | Fair Value, Nonrecurring [Member] | Other Real Estate Owned [Member] |  |  |  |  |
Assets, fair value disclosure | [1] | 0 |  | 0 |
Fair Value, Inputs, Level 1 [Member] | Fair Value, Nonrecurring [Member] | Investments in Venture Capital and Private Company Stock [Member] |  |  |  |  |
Assets, fair value disclosure |  | 0 |  | 0 |
Fair Value, Inputs, Level 2 [Member] |  |  |  |  |
Assets, fair value disclosure |  | 874,630 |  | 963,669 |
Fair Value, Inputs, Level 2 [Member] | Fair Value, Nonrecurring [Member] |  |  |  |  |
Assets, fair value disclosure |  | 905 |  | 905 |
Fair Value, Inputs, Level 2 [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  | 0 |  | 0 |
Fair Value, Inputs, Level 2 [Member] | Fair Value, Nonrecurring [Member] | Other Real Estate Owned [Member] |  |  |  |  |
Assets, fair value disclosure | [1] | 905 |  | 905 |
Fair Value, Inputs, Level 2 [Member] | Fair Value, Nonrecurring [Member] | Investments in Venture Capital and Private Company Stock [Member] |  |  |  |  |
Assets, fair value disclosure |  | 0 |  | 0 |
Fair Value, Inputs, Level 3 [Member] |  |  |  |  |
Assets, fair value disclosure |  | 16 |  | 21 |
Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member] |  |  |  |  |
Assets, fair value disclosure |  | 30,617 |  | 41,015 |
Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  | 25,287 |  | 35,398 |
Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member] | Other Real Estate Owned [Member] |  |  |  |  |
Assets, fair value disclosure | [1] | 4,236 |  | 4,236 |
Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member] | Investments in Venture Capital and Private Company Stock [Member] |  |  |  |  |
Assets, fair value disclosure |  | 1,094 |  | 1,381 |
Commercial Portfolio Segment [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  | 14,258 |  | 5,342 |
Total Losses |  | 0 | 0 | 7,012 | 0
Commercial Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  | 0 |  | 0 |
Commercial Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  | 0 |  | 0 |
Commercial Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  | 14,258 |  | 5,342 |
Commercial Real Estate Portfolio Segment [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  | 11,029 |  | 25,749 |
Total Losses |  | 0 | $ 0 | 0 | 0
Commercial Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  | 0 |  | 0 |
Commercial Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  | 0 |  | 0 |
Commercial Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  | $ 11,029 |  | 25,749 |
Residential Mortgage and Equity Lines Portfolio Segment [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  |  |  | 4,307 |
Total Losses |  |  |  | 0 | $ 0
Residential Mortgage and Equity Lines Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  |  |  | 0 |
Residential Mortgage and Equity Lines Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  |  |  | 0 |
Residential Mortgage and Equity Lines Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member] | Loans Receivable [Member] |  |  |  |  |
Assets, fair value disclosure |  |  |  | $ 4,307 |
[1] | Other real estate owned balance of $4.9 million in the condensed consolidated balance sheets is net of estimated disposal costs.

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