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Loans - Major Classifications - Loan Concentrations (Details) - Real Estate Portfolio Segment [Member] - Loan receivables - Customer Concentration Risk [Member] | 3 Months Ended
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Mar. 31, 2019 | Mar. 31, 2018
Loans |  |
Credit risk as a percentage of benchmark |  | 77.90%
Loans receivable as a percentage of total portfolio | 76.90% |

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