Represents carrying value of securities pledged to federal home loan bank during the reporting period.

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Debt Instrument, Covenant Terms, Debt Service Coverage Ratio, Percent

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Debt Instrument, Covenant Terms, Interest Coverage Ratio

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Debt Instrument, Covenant Terms, Liquidity Ratio, Percent

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Debt Instrument, Covenant Terms, Liquidity Ratio in Consecutive Quarters, Percent

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No definition available.

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- Definition

Debt Instrument, Covenant Terms, Ratio of Non-performing Assets to Total Assets

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No definition available.

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Debt Instrument, Covenant Terms, Return on Average Assets, Next Nine Months, Percent

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Debt Instrument, Covenant Terms, Return on Average Assets, Thereafter, Percent

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Debt Instrument, Covenant Terms, Texas Ratio, Non-performing Assets as a Percentage of Tangible Equity and Allowance for Loan and Lease Losses

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No definition available.

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Line of Credit Facility, Initial Period

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Line of Credit Facility, Variable Rate, Floor, Percentage

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No definition available.

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- Definition

The aggregate amount of recurring noncash expense charged against earnings in the period to allocate the cost of assets over their estimated remaining economic lives.

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- Definition

The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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No definition available.

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- Definition

Amount of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

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- Definition

Discloses the single interest rate [if] applicable to the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

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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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No definition available.

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- Definition

Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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- Definition

The effective interest rate at the end of the reporting period.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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- Definition

The amount of Tier 1 Leverage Capital required to be categorized as well capitalized divided by average assets as defined in the regulatory framework for prompt corrective action.

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The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action.

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Federal Home Loan Bank Advances and Other Borrowings (FY) (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Oct. 31, 2017	Dec. 31, 2016	Aug. 28, 2015
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Long-term line of credit	$ 10,000,000
Carrying value of securities pledged to Federal Home Loan Bank	$ 16,252,434		$ 14,844,441
Interest rate at period end (as a percent)	4.25%
Federal Home Loan Bank borrowings, fair value	$ 0		$ 5,765
Federal funds purchased	33,600,000
Fiscal quarter 2019 [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Amortization	262,500
Fiscal quarter 2020 [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Amortization	287,500
Fiscal Quarter 2021 [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Amortization	312,500
Fiscal Quarter 2022 [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Amortization	$ 337,500
Long-term advance dated January 10, 2007, Fixed Interest at 4.25, with a put option exercisable in January 2008 and then quarterly thereafter, principal due in January 2017 [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank, advances, interest rate (as a percent)	4.25%		4.25%
Federal Home Loan Bank Advances [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Line of credit facility, maximum borrowing capacity	$ 36,224,294
Revolving Credit Facility [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Line of credit facility, maximum borrowing capacity		$ 15,000,000		$ 8,000,000
Covenant compliance, ratio of non-performing assets as a percentage total assets, not to be greater than	3.25%
Covenant compliance, Texas ratio, not to be greater than (as a percent)	35.00%
Covenant compliance, liquidity ratio, not to be less than (as a percent)	9.00%
Covenant compliance, liquidity ratio in consecutive quarters, not to be less than (as a percent)	10.00%
Covenant terms, return on average assets, next nine months (as a percent)	0.45%
Covenant terms, return on average assets, thereafter (as a percent)	0.50%
Covenant terms, debt service coverage ratio	0.0125
Covenant compliance, interest coverage ratio, not to be less than	2.50
Revolving Credit Facility [Member] \| Prime Rate [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Initial line of credit period	90 days
Variable rate, floor (as a percent)	3.50%
Basis spread on variable rate (as a percent)	(0.25%)
Subsidiaries [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Total risk-based capital ratio required to well-capitalized	10.50%
Tier 1 risk-based capital ratio required to be well capitalized	9.50%
Tier 1 leverage ratio required to be well capitalized	8.00%