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Loans Receivable - Troubled Debt Restructuring (Details) - USD ($) | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Mar. 31, 2019 | Dec. 31, 2017 | Dec. 31, 2018
Financing Receivable, Modifications [Line Items] |  |  |
Outstanding Commitments To Borrowers Loans Classified As Troubled Debt Restructurings | $ 0 | $ 0 |
Troubled Debt Restructurings |  |  |
Financing receivable modifications | 17,000 |  |
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount | 0 |  | $ 0.0
One-to-four family residential real estate loans - non-owner occupied loans [Member] | Non Accrual Loans [Member] |  |  |
Troubled Debt Restructurings |  |  |
Financing receivable modifications | $ 17,000 |  | $ 17,000

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- Definition Outstanding commitments to borrowers loans classified as troubled debt restructurings. + References No definition available. + Details
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- Definition Troubled debt restructurings. + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554 + Details
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- Definition Amount of allowance for credit losses related to recorded investment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524 + Details
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- Details
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