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Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands | 3 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2020 | Mar. 31, 2019 | Dec. 31, 2019 | Dec. 31, 2018
Commitments And Contingencies [Line Items] |  |  |  |
Allowance for credit loss | $ 43,356 | $ 33,327 | $ 40,076 | $ 33,914
Unfunded Commitments [Member] |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |
Credit loss expense | 493 | $ 0 |  |
Unfunded Commitments [Member] | Other Liabilities [Member] |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |
Allowance for credit loss | $ 2,600 |  | $ 0 |

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