Investment and Mortgage-Backed Securities, Available for Sale (Schedule of Available for Sale Securities) (Details) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Available For Sale Securities Pledged as Collateral, Amortized Cost Basis	$ 288,000,000.0	$ 263,300,000
Pledged Assets Separately Reported, Other Debt Securities Available-for-sale or Held-for-investment	296,900,000	274,400,000
Amortized Cost of Investment And Mortgage-Backed Securities Available For Sale	558,836,046	572,137,595
Available-for-sale Securities, Gross Unrealized Gains	14,031,773	19,456,692
Available-for-sale Securities, Gross Unrealized Losses	4,080,236	2,269,886
Available-for-sale Securities, Fair Value Disclosure	568,787,583	589,324,401
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost of Investment And Mortgage-Backed Securities Available For Sale	42,761,381	42,793,179
Available-for-sale Securities, Gross Unrealized Gains	4,899,936	6,023,263
Available-for-sale Securities, Gross Unrealized Losses	27,382	0
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost of Investment And Mortgage-Backed Securities Available For Sale	32,900,000	37,000,000.0
Available-for-sale Securities, Fair Value Disclosure	33,400,000
Investments [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Gross Realized Gains		220,239
Collateralized Loan Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost of Investment And Mortgage-Backed Securities Available For Sale	61,405,854	61,244,212
Available-for-sale Securities, Gross Unrealized Losses	124,852	382,986
Available-for-sale Securities, Gross Realized Gains	513,332
SBA Bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost of Investment And Mortgage-Backed Securities Available For Sale	150,110,110	153,565,023
Available-for-sale Securities, Gross Unrealized Gains	731,545	797,456
Available-for-sale Securities, Gross Unrealized Losses	1,208,492	1,057,454
Mortgage-Backed Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost of Investment And Mortgage-Backed Securities Available For Sale	256,890,411	267,854,880
Available-for-sale Securities, Gross Unrealized Gains	7,485,115	10,672,412
Available-for-sale Securities, Gross Unrealized Losses	1,581,684	754,278
Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost of Investment And Mortgage-Backed Securities Available For Sale	47,668,290	46,680,301
Available-for-sale Securities, Gross Unrealized Gains	401,845	1,743,322
Available-for-sale Securities, Gross Unrealized Losses	1,137,826	75,168
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Fair Value Disclosure	47,633,935	48,816,442
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Collateralized Loan Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Fair Value Disclosure	61,794,334	61,081,465
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| SBA Bonds
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Fair Value Disclosure	149,633,163	153,305,025
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Mortgage-Backed Securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Fair Value Disclosure	262,793,842	277,773,014
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Fair Value Disclosure	$ 46,932,309	$ 48,348,455

Available For Sale Securities Pledged as Collateral, Amortized Cost Basis

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- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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Amount of unrealized gain before deducting unrealized loss on investments in debt and equity securities classified as available-for-sale securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
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Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale securities.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 50
-Paragraph 2
-Subparagraph (c)
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The fair value, as of the date of each statement of financial position presented, of other securities, classified as available for sale or held for investment, which are owned but transferred to serve as collateral for the payment of the related debt obligation, primarily a secured borrowing or repurchase agreement, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66007379&loc=d3e113888-111728

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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.

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