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Investment Securities Text Tags (Details) | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Sep. 30, 2020 USD ($) | Sep. 30, 2020 USD ($) | Sep. 30, 2019 USD ($) | Mar. 31, 2020 USD ($)
Schedule of Investments [Line Items] |  |  |  |
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | 11 | 11 |  | 7
Debt Securities, Available-for-sale | $ 103,075,000 | $ 103,075,000 |  | $ 65,829,000
Percentage Available-for-sale Securities | 91.60% | 91.60% |  |
Debt Securities, Held-to-maturity | $ 9,501,000 | $ 9,501,000 |  | 10,151,000
Percentage Held-to-maturity Securities | 8.40% | 8.40% |  |
Trading | $ 0 | $ 0 |  |
Proceeds from Sale of Available-for-sale Securities | $ 0 | $ 30,190,000 | $ 0 |
Mortgage-backed securities |  |  |  |
Schedule of Investments [Line Items] |  |  |  |
Number of AFS securities in Unrealized Loss Positions, greater than or equal to 12 months | 1 | 1 |  |
Debt Securities, Held-to-maturity | $ 8,501,000 | $ 8,501,000 |  | $ 9,151,000
US Government Agency Securities |  |  |  |
Schedule of Investments [Line Items] |  |  |  |
Percentage Available-for-Sale, Continuos Unrealized Loss Position | 52.60% | 52.60% |  |
Number of AFS securities in Unrealized Loss Positions, greater than or equal to 12 months | 3 | 3 |  |
Municipal Securities |  |  |  |
Schedule of Investments [Line Items] |  |  |  |
Percentage Available-for-Sale, Continuos Unrealized Loss Position | 26.40% | 26.40% |  |

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- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121558606&loc=SL82898722-210454 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121553693&loc=d3e26610-111562 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27161-111563 + Details
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