West Bancorporation (WTBA) 10-K 1 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 28, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	WEST BANCORPORATION INC
Entity Central Index Key	1,166,928
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-K
Document Period Date	Dec. 31, 2017
Document Fiscal Year Focus	2,107
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		16,215,672
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 372,424,686

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and due from banks	$ 34,952	$ 40,943
Federal funds sold	12,997	35,893
Cash and cash equivalents	47,949	76,836
Investment securities available for sale, at fair value	444,219	260,637
Investment securities held to maturity, at amortized cost (fair value of $45,890 and $47,789 at December 31, 2017 and 2016, respectively)	45,527	48,386
Federal Home Loan Bank stock, at cost	9,174	10,771
Loans	1,510,500	1,399,870
Allowance for loan losses	(16,430)	(16,112)
Loans, net	1,494,070	1,383,758
Premises and equipment, net	23,022	23,314
Accrued interest receivable	7,344	5,321
Bank-owned life insurance	33,618	33,111
Deferred tax assets, net	4,645	6,957
Other assets	4,809	5,113
Total assets	2,114,377	1,854,204
Deposits:
Noninterest-bearing demand	395,888	479,311
Interest-bearing demand	395,052	282,592
Savings	850,216	668,688
Time of $250 or more	16,965	10,446
Other time	152,692	105,568
Total deposits	1,810,813	1,546,605
Federal funds purchased	545	9,690
Subordinated notes, net	20,412	20,398
Federal Home Loan Bank advances, net	76,382	99,886
Long-term debt, net	22,917	5,126
Accrued expenses and other liabilities	5,210	7,123
Total liabilities	1,936,279	1,688,828
COMMITMENTS AND CONTINGENCIES (Note 16)
STOCKHOLDERS’ EQUITY
Preferred stock, $0.01 par value; authorized 50,000,000 shares; no shares issued and outstanding at December 31, 2017 and 2016	0	0
Common stock, no par value; authorized 50,000,000 shares; 16,215,672 and 16,137,999 shares issued and outstanding at December 31, 2017 and 2016, respectively	3,000	3,000
Additional paid-in capital	23,463	21,462
Retained earnings	153,527	141,956
Accumulated other comprehensive loss	(1,892)	(1,042)
Total stockholders’ equity	178,098	165,376
Total liabilities and stockholders’ equity	$ 2,114,377	$ 1,854,204

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets [Abstract]
Investment securities held to maturity, fair value	$ 45,890	$ 47,789
Preferred Stock:
Preferred stock, par value ($ per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common Stock:
Common stock, no par value
Common stock, share authorized	50,000,000	50,000,000
Common stock, share issued	16,215,672	16,137,999
Common stock, shares outstanding	16,215,672	16,137,999

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income:
Loans, including fees	$ 63,242	$ 57,419	$ 52,556
Investment securities:
Taxable	5,501	4,201	4,363
Tax-exempt	3,960	3,266	3,147
Federal funds sold	331	108	81
Total interest income	73,034	64,994	60,147
Interest expense:
Deposits	7,622	3,391	2,185
Federal funds purchased	99	47	46
Subordinated notes	901	728	705
Federal Home Loan Bank advances	3,836	3,565	2,825
Long-term debt	519	145	232
Total interest expense	12,977	7,876	5,993
Net interest income	60,057	57,118	54,154
Provision for loan losses	0	1,000	850
Net interest income after provision for loan losses	60,057	56,118	53,304
Noninterest income:
Service charges on deposit accounts	2,632	2,461	2,609
Debit card usage fees	1,754	1,825	1,830
Trust services	1,705	1,310	1,286
Increase in cash value of bank-owned life insurance	652	647	727
Gain from bank-owned life insurance	307	443	0
Realized investment securities gains, net	326	66	47
Other income	1,272	1,230	1,704
Total noninterest income	8,648	7,982	8,203
Noninterest expense:
Salaries and employee benefits	17,633	16,731	16,065
Occupancy	4,406	4,033	4,105
Data processing	2,677	2,510	2,329
FDIC insurance	677	937	839
Professional fees	1,075	774	748
Director fees	950	888	881
Other expenses	4,849	5,275	5,101
Total noninterest expense	32,267	31,148	30,068
Income before income taxes	36,438	32,952	31,439
Income taxes	13,368	9,936	9,697
Net income	$ 23,070	$ 23,016	$ 21,742
Basic earnings per common share	$ 1.42	$ 1.43	$ 1.35
Diluted earnings per common share	$ 1.41	$ 1.42	$ 1.35

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	$ 23,070	$ 23,016	$ 21,742
Total other comprehensive loss	(850)	(612)	(684)
Comprehensive income	22,220	22,404	21,058
Unrealized gains losses on derivatives [Member]
Unrealized gains (losses) on derivatives arising during the period	(66)	882	(1,144)
Less: reclassification adjustment for net loss on derivatives realized in net income	304	464	89
Less: reclassification adjustment for amortization of derivative termination costs, realized in interest expense	109	109	71
Income tax (expense) benefit	(132)	(553)	374
Other comprehensive income (loss) on derivatives	215	902	(610)
Unrealized gains losses on securities [Member]
Unrealized holding gains arising during the period	(1,124)	(2,249)	(33)
Less: reclassification adjustment for net (gains) losses realized in net income	(326)	(66)	(47)
Less: reclassification adjustment for amortization of net unrealized gains on securities transferred from available for sale to held to maturity, realized in interest income	(268)	(128)	(39)
Income tax (expense) benefit	653	929	45
Other comprehensive income on available for sale securities, net of tax	$ (1,065)	$ (1,514)	$ (74)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2014	$ 140,175	$ 0	$ 3,000	$ 18,971	$ 117,950	$ 254
Common stock, shares outstanding at Dec. 31, 2014			16,018,734
Stockholders' Equity [Roll Forward]
Net income	21,742	0	$ 0	0	21,742	0
Total other comprehensive income (loss), net of tax	(684)	0	0	0	0	(684)
Cash dividends declared, common stock	(9,952)	0	0	0	(9,952)	0
Stock-based compensation costs	1,166	0	0	1,166	0	0
Issuance of common stock upon vesting of restricted stock units, net of shares withheld for payroll taxes, value	(225)	0	$ 0	(225)	0	0
Issuance of common stock upon vesting of restricted stock units, net of shares withheld for payroll taxes, shares			45,701
Excess tax benefits from vesting of restricted stock units	155	0	$ 0	155	0	0
Balance at Dec. 31, 2015	152,377	0	$ 3,000	20,067	129,740	(430)
Common stock, shares outstanding at Dec. 31, 2015			16,064,435
Stockholders' Equity [Roll Forward]
Net income	23,016	0	$ 0	0	23,016	0
Total other comprehensive income (loss), net of tax	(612)	0	0	0	0	(612)
Cash dividends declared, common stock	(10,800)	0	0	0	(10,800)	0
Stock-based compensation costs	1,684	0	0	1,684	0	0
Issuance of common stock upon vesting of restricted stock units, net of shares withheld for payroll taxes, value	(394)	0	$ 0	(394)	0	0
Issuance of common stock upon vesting of restricted stock units, net of shares withheld for payroll taxes, shares			73,564
Excess tax benefits from vesting of restricted stock units	105	0	$ 0	105	0	0
Balance at Dec. 31, 2016	$ 165,376	0	$ 3,000	21,462	141,956	(1,042)
Common stock, shares outstanding at Dec. 31, 2016	16,137,999		16,137,999
Stockholders' Equity [Roll Forward]
Net income	$ 23,070	0	$ 0	0	23,070	0
Total other comprehensive income (loss), net of tax	(850)	0	0	0	0	(850)
Cash dividends declared, common stock	(11,499)	0	0	0	(11,499)	0
Stock-based compensation costs	2,632	0	0	2,632	0	0
Issuance of common stock upon vesting of restricted stock units, net of shares withheld for payroll taxes, value	(631)	0	$ 0	(631)	0	0
Issuance of common stock upon vesting of restricted stock units, net of shares withheld for payroll taxes, shares			77,673
Balance at Dec. 31, 2017	$ 178,098	$ 0	$ 3,000	$ 23,463	$ 153,527	$ (1,892)
Common stock, shares outstanding at Dec. 31, 2017	16,215,672		16,215,672

Consolidated Statements of Sto7

Consolidated Statements of Stockholders' Equity (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Cash dividends declared per common share	$ 0.71	$ 0.67	$ 0.62

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities:
Net income	$ 23,070	$ 23,016	$ 21,742
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	0	1,000	850
Net amortization and accretion	4,155	4,290	3,892
Investment securities gains, net	(326)	(66)	(47)
Stock-based compensation	2,632	1,684	1,166
Gain on sale of loans held for sale	0	0	(14)
Proceeds from sales of loans held for sale	0	0	840
Increase in cash value of bank-owned life insurance	(652)	(647)	(727)
Gain from bank-owned life insurance	(307)	(443)	0
Depreciation	1,347	1,046	921
Deferred income taxes	2,833	89	82
Change in assets and liabilities:
Increase in accrued interest receivable	(2,023)	(633)	(263)
(Increase) decrease in other assets	131	(85)	2,951
Increase (decrease) in accrued expenses and other liabilities	(1,503)	1,047	(196)
Net cash provided by operating activities	29,357	30,298	31,197
Cash Flows from Investing Activities:
Proceeds from sales of investment securities available for sale	108,584	3,054	16,946
Proceeds from maturities and calls of investment securities	47,781	58,358	49,665
Purchases of investment securities available for sale	(341,012)	(3,500)	(116,824)
Purchases of Federal Home Loan Bank stock	(19,414)	(17,407)	(19,986)
Proceeds from redemption of Federal Home Loan Bank stock	21,011	19,083	22,614
Net increase in loans	(110,312)	(153,037)	(62,133)
Proceeds from sales of other real estate owned	0	0	2,227
Purchases of premises and equipment	(1,055)	(12,802)	(2,502)
Proceeds of principal and earnings from bank-owned life insurance	452	812	0
Proceeds from settlement of other assets	0	0	3,593
Net cash used in investing activities	(293,965)	(105,439)	(106,400)
Cash Flows from Financing Activities:
Net increase in deposits	264,208	105,876	170,267
Net decrease in federal funds purchased	(9,145)	(12,070)	(47,215)
Proceeds from long-term debt	22,000	0	0
Principal payments on long-term debt	(4,212)	(3,286)	(4,261)
Principal payments on Federal Home Loan Bank advances	(25,000)	0	0
Interest rate swap termination costs paid	0	0	(541)
Common stock dividends paid	(11,499)	(10,800)	(9,952)
Restricted stock units withheld for payroll taxes	(631)	(394)	(225)
Net cash provided by financing activities	235,721	79,326	108,073
Net increase (decrease) in cash and cash equivalents	(28,887)	4,185	32,870
Cash and Cash Equivalents:
Beginning	76,836	72,651	39,781
Ending	47,949	76,836	72,651
Supplemental Disclosure of Cash Flow Information:
Interest	12,520	7,940	6,069
Income taxes	$ 9,300	$ 7,870	$ 6,700

Organization and Nature of Busi

Organization and Nature of Business and Summary of Significant Accounting Policies (Notes)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]	Organization and Nature of Business and Summary of Significant Accounting Policies Organization and nature of business : West Bancorporation, Inc. operates in the commercial banking industry through its wholly-owned subsidiary, West Bank. West Bank is a state chartered bank and has its main office in West Des Moines, Iowa, with seven additional offices located in the Des Moines, Iowa, metropolitan area, one office located in Iowa City, Iowa, one office located in Coralville, Iowa, and one office located in Rochester, Minnesota. As used herein, the term “Company” refers to West Bancorporation, Inc., or if the context dictates, West Bancorporation, Inc. and its subsidiary. Significant accounting policies : Accounting estimates and assumptions : The consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (GAAP) established by the Financial Accounting Standards Board (FASB). References to GAAP issued by the FASB in these footnotes are to the FASB Accounting Standards Codification TM , sometimes referred to as the Codification or ASC. In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses for the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near term are the fair value of financial instruments and the allowance for loan losses. Consolidation policy : The consolidated financial statements include the accounts of the Company, West Bank and West Bank’s wholly-owned subsidiary WB Funding Corporation (which owned an interest in a limited liability company that was sold in the fourth quarter of 2015). All significant intercompany transactions and balances have been eliminated in consolidation. In addition, the Company owns an unconsolidated subsidiary, West Bancorporation Capital Trust I (the Trust), which was formed for the purpose of issuing trust preferred securities. In accordance with GAAP, the results of the Trust are recorded on the books of the Company using the equity method of accounting and are not consolidated. Reclassification: Certain amounts in prior year financial statements have been reclassified, with no effect on net income, comprehensive income or stockholder's equity, to conform with current period presentation. Segment information: An operating segment is generally defined as a component of a business for which discrete financial information is available and whose operating results are regularly reviewed by the chief operating decision-maker. The Company has determined that its business is comprised of one operating segment, which is banking. The banking segment generates revenue through interest and fees on loans, interest on investment securities, service charges on deposit accounts, fees for trust services and other miscellaneous banking related activities. This segment includes the Company, West Bank, and related elimination entries between the two, as the Company’s operation is similar to that of West Bank. Comprehensive income : Comprehensive income consists of net income and other comprehensive income (OCI). OCI consists of the net change in unrealized gains and losses on the Company’s investment securities available for sale, including the noncredit-related portion of unrealized gains (losses) of OTTI securities, if any, and the effective portion of the change in fair value of derivative instruments. OCI also includes the amortization of derivative termination costs and the amortization of unrealized gains on investment securities transferred from available for sale to held to maturity. Cash and cash equivalents and cash flows : For statement of cash flow purposes, the Company considers cash, due from banks and federal funds sold to be cash and cash equivalents. Cash inflows and outflows from loans and deposits are reported on a net basis. Investment securities : Investment securities that management has the intent and ability to hold to maturity are classified as held to maturity and reported at amortized cost. Investment securities that may be sold for general liquidity needs, in response to market interest rate fluctuations, implementation of asset-liability management strategies, funding loan demand, changes in securities prepayment risk or other similar factors are classified as available for sale and reported at fair value, with unrealized gains and losses reported as a separate component of accumulated other comprehensive income (AOCI), net of deferred income taxes. Realized gains and losses on sales of investment securities are computed on a specific identification basis based on amortized cost. The amortized cost of debt securities classified as held to maturity or available for sale is adjusted for accretion of discounts to maturity and amortization of premiums over the estimated average life of each security or, in the case of callable securities, through the first call date, using the effective yield method. Such amortization and accretion is included in interest income. Interest income on securities is recognized using the interest method according to the terms of the investment security. The Company evaluates each of its investment securities whose value has declined below amortized cost to determine whether the decline in fair value is OTTI. When determining whether an investment security is OTTI, management assesses the severity and duration of the decline in fair value, the length of time expected for recovery, the financial condition of the issuer and other qualitative factors, as well as whether: (a) it has the intent to sell the security, and (b) it is more likely than not that it will be required to sell the security prior to its anticipated recovery. In instances when a determination is made that an OTTI exists but management does not intend to sell the security and it is not more likely than not that it will be required to sell the security prior to its anticipated repayment or maturity, the OTTI is separated into: (a) the amount of the total OTTI related to a decrease in cash flows expected to be collected from the security (the credit loss); and (b) the amount of the total OTTI related to all other factors. The amount of the total OTTI related to the credit loss is recognized as a charge to earnings. The amount of the total OTTI related to all other factors is recognized in OCI. If the Company intends to sell or it is more likely than not that it will be required to sell a security with OTTI before recovery of its amortized cost basis, the OTTI is recognized in earnings equal to the entire difference between the investment’s amortized cost basis and its fair value at the balance sheet date. Federal Home Loan Bank stock : West Bank, as a member of the Federal Home Loan Bank (FHLB) system, is required to maintain an investment in capital stock of the FHLB in an amount equal to 0.12 percent of total assets plus 4.00 percent of outstanding advances from the FHLB and the outstanding principal balance of loans previously issued through the Mortgage Partnership Finance Program (MPF). No ready market exists for the FHLB stock, and it has no quoted market value. The Company evaluates this asset for impairment on a quarterly basis and determined there was no impairment as of December 31, 2017 . All shares of FHLB stock are issued and redeemed at par value. Loans : Loans are stated at the principal amounts outstanding, net of unamortized loan fees and costs, with interest income recognized on the interest method based upon the terms of the loan. Loan origination fees, net of certain direct origination costs, are deferred and recognized as an adjustment of the related loan yield using the interest method. Loans are reported by the portfolio segments identified and are analyzed by management on this basis. All loan policies identified below apply to all segments of the loan portfolio. Delinquencies are determined based on the payment terms of the individual loan agreements. The accrual of interest on past due and other impaired loans is generally discontinued at 90 days past due or when, in the opinion of management, the borrower may be unable to make all payments pursuant to contractual terms. Unless considered collectible, all interest accrued but not collected for loans that are placed on nonaccrual or charged off is reversed against interest income, if accrued in the current year, or charged to the allowance for loan losses, if accrued in the prior year. Generally, all payments received while a loan is on nonaccrual status are applied to the principal balance of the loan. Loans are returned to accrual status when all principal and interest amounts contractually due are brought current and future payments are reasonably assured. A loan is classified as troubled debt restructured (TDR) when the Company separately concludes that a borrower is experiencing financial difficulties and a concession is granted that would not otherwise be considered. Concessions may include a restructuring of the loan terms to alleviate the burden of the borrower’s cash requirements, such as an extension of the payment terms beyond the original maturity date or a change in the interest rate charged. TDR loans with extended payment terms are accounted for as impaired until performance is established. A change to the interest rate would change the classification of a loan to a TDR loan if the restructured loan yields a rate that is below a market rate for that of a new loan with comparable risk. TDR loans with below market rates are considered impaired until fully collected. TDR loans may also be reported as nonaccrual or 90 days past due if they are not performing per the restructured terms. Based upon its ongoing assessment of credit quality within the loan portfolio, the Company maintains a Watch List, which includes loans classified as Doubtful, Substandard and Watch according to the Company’s classification criteria. These loans involve the anticipated potential for payment defaults or collateral inadequacies. A loan on the Watch List is considered impaired when management believes it is probable the Company will be unable to collect all contractual principal and interest payments due in accordance with the terms of the loan agreement. Impaired loans are measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate or, as a practical expedient, at the loan’s observable market price or the fair value of the collateral if the loan is collateral dependent. The amount of impairment, if any, and any subsequent changes are included in the allowance for loan losses. Allowance for loan losses : The allowance for loan losses is established through a provision for loan losses charged to expense. The allowance is an amount that management believes will be adequate to absorb probable losses on existing loans based on an evaluation of the collectability of loans and prior loss experience. This evaluation also takes into consideration such factors as changes in the nature and volume of the loan portfolio, overall portfolio quality, the review of specific problem loans, and current economic conditions that may affect the borrowers’ ability to pay. Loans are charged off against the allowance for loan losses when management believes that collectability of the principal is unlikely. While management uses the best information available to make its evaluations, future adjustments to the allowance may be necessary if there are significant changes in economic conditions or the other factors relied upon. The allowance for loan losses consists of specific and general components. The specific component relates to loans that meet the definition of impaired. The general component covers the remaining loans and is based on historical loss experience adjusted for qualitative factors such as delinquency trends, loan growth, economic elements and local market conditions. These same policies are applied to all segments of loans. In addition, regulatory agencies, as integral parts of their examination processes, periodically review the Company’s allowance for loan losses, and may require the Company to make additions to the allowance based on their judgment about information available to them at the time of their examinations. Premises and equipment : Premises and equipment are stated at cost less accumulated depreciation. The straight-line method of depreciation and amortization is used for calculating expense. The estimated useful lives of premises and equipment range up to 40 years for buildings, up to 10 years for furniture and equipment, and the shorter of the estimated useful life or lease term for leasehold improvements. Other real estate owned : Real estate properties acquired through or in lieu of foreclosure are initially recorded at fair value less estimated selling cost at the date of foreclosure, establishing a new cost basis. Fair value is determined by management by obtaining appraisals or other market value information at least annually. Any write-downs in value at the date of acquisition are charged to the allowance for loan losses. After foreclosure, valuations are periodically performed by management by obtaining updated appraisals or other market value information. Any subsequent write-downs are recorded as a charge to operations, if necessary, to reduce the carrying value of a property to the updated fair value less estimated selling cost. Net costs related to the holding of properties are included in noninterest expense. As of December 31, 2017 and 2016 , the Company had no other real estate owned. Trust assets : Assets held by West Bank in fiduciary or agency capacities, other than trust cash on deposit at West Bank, are not included in the consolidated balance sheets of the Company, as such assets are not assets of West Bank. The Company managed or administered accounts with assets totaling $306,974 as of December 31, 2017 , compared to assets totaling $251,767 as of December 31, 2016 . Bank-owned life insurance : The carrying amount of bank-owned life insurance consists of the initial premium paid, plus increases in cash value, less the carrying amount associated with any death benefit received. Death benefits paid in excess of the applicable carrying amount are recognized as income. Increases in cash value and the portion of death benefits recognized as income are exempt from income taxes. Derivatives: The Company uses derivative financial instruments (which consist of interest rate swaps) to assist in its interest rate risk management. All derivatives are measured and reported at fair value on the Company’s consolidated balance sheet as other assets or other liabilities. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative and the resulting designation. As of December 31, 2017 , the Company had cash flow hedging relationships, which were derivatives to hedge the exposure to variability in expected future cash flows. To qualify for hedge accounting, the Company must comply with the detailed rules and documentation requirements at the inception of the hedge, and hedge effectiveness is assessed at inception and on a quarterly basis throughout the life of each hedging relationship. Hedge ineffectiveness, if any, is measured periodically throughout the life of the hedging relationship. The Company does not use derivatives for trading or speculative purposes. For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of the derivative is initially reported in OCI, net of deferred taxes, and subsequently reclassified to interest income or expense when the hedged transaction affects earnings, while the ineffective portion of changes in the fair value of the derivative, if any, is recognized immediately in other noninterest income. The Company assesses the effectiveness of the hedging relationship by comparing the cumulative changes in cash flows of the derivative hedging instrument with the cumulative changes in cash flows of the designated hedged item or transaction. Stock-based compensation: The Company’s current and previous equity incentive plans were approved by the stockholders as a means to attract, retain and reward selected participants. The plans are administered by the Compensation Committee of the Board of Directors. Compensation expense for stock-based awards is recognized on a straight-line basis over the vesting period using the fair value of the award at the time of the grant. The restricted stock unit (RSU) participants do not have dividend rights prior to vesting, so the fair value of nonvested RSUs is equal to the fair market value of the underlying common stock at the grant date, reduced by the present value of the dividends expected to be paid on the underlying shares during the vesting period. Prior to January 1, 2017, the Company assumed no projected forfeitures on its stock-based compensation, since all RSUs were expected to vest and no forfeitures had occurred as of December 31, 2016. Upon adoption of ASU No. 2016-09, Compensation - Stock Compensation (Topic 718) on January 1, 2017, the Company made the accounting policy election to account for forfeitures as they occur. Deferred compensation: The West Bancorporation, Inc. Deferred Compensation Plan (the Deferred Compensation Plan) was adopted effective January 1, 2013, to provide certain individuals with additional deferral opportunities in planning for retirement. Eligible participants, including directors and key officers of the Company, may choose to voluntarily defer receipt of a portion of their respective cash compensation. The Deferred Compensation Plan is an unfunded, nonqualified deferred compensation plan intended to conform to the requirements of Section 409A of the Internal Revenue Code. As of December 31, 2017 , no individuals had chosen to participate in the Plan. Transfer of financial assets : Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when the assets have been isolated from the Company, the transferee obtains the right, free of conditions that constrain it from taking advantage of that right, to pledge or exchange the transferred assets, and the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. Income taxes : The Company files a consolidated federal income tax return. Income tax expense is generally allocated as if the Company and its subsidiary file separate income tax returns. Deferred taxes are provided on an asset and liability method whereby deferred tax assets are recognized for deductible temporary differences, capital losses and net operating losses, and deferred tax liabilities are recognized for taxable temporary differences. Temporary differences are the differences between the reported amounts of assets and liabilities and their tax basis. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion or all of the deferred tax assets will not be realized. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. When tax returns are filed, it is highly certain that some tax positions taken will be sustained upon examination by the taxing authorities, while others are subject to uncertainty about the merits of the positions taken or the amount of the position that would be ultimately sustained. The benefit of a tax position is recognized in the consolidated financial statements in the period during which, based on all available evidence, management believes it is more likely than not that the position will be sustained upon examination, including the resolution of appeals or litigation processes, if any. The evaluation of a tax position taken is considered by itself and is not offset or aggregated with other positions. Tax positions that meet the more likely than not recognition threshold are measured as the largest amount of tax benefit that is more than 50 percent likely of being realized upon settlement with the applicable taxing authority. Management does not believe the Company has any material uncertain tax positions to disclose. Interest and penalties, if any, related to income taxes are recorded as other noninterest expense in the consolidated income statements in the year assessed. Earnings per common share : Basic earnings per common share are computed by dividing net income by the weighted average number of common shares outstanding for the period. Diluted earnings per common share reflect the potential dilution that could occur if the Company’s outstanding RSUs were vested. The dilutive effect is computed using the treasury stock method, which assumes all stock-based awards were exercised and the hypothetical proceeds from exercise were used by the Company to purchase common stock at the average market price during the period. Current accounting developments : In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). The guidance in this update supersedes the revenue recognition requirements in ASC Topic 605, Revenue Recognition, and most industry-specific guidance throughout the industry topics of the Codification. For public companies, this update will be effective for interim and annual periods beginning after December 15, 2017. The Company adopted the guidance effective January 1, 2018, using the modified retrospective method. The Company's revenue is primarily composed of interest income on financial instruments, including investment securities and loans, which are excluded from the scope of this update. Also excluded from the scope of the update is revenue from bank-owned life insurance, loan fees and letter of credit fees. Service charges on deposit accounts are within the scope of the guidance; however, current revenue recognition practices will not change under the guidance, as deposit agreements are considered day-to-day contracts. Other noninterest income sources of revenue are considered immaterial. Implementation of the guidance will not change current business practices or internal controls for financial reporting. Implementation of the guidance will not have a material impact on the Company's consolidated financial statements. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. The update enhances the reporting model for financial instruments to provide users of financial statements with more decision-useful information by updating certain aspects of recognition, measurement, presentation and disclosure of financial instruments. Among other changes, the update requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes, and clarifies that entities should evaluate the need for a valuation allowance on a deferred tax asset related to available for sale securities in combination with the entities' other deferred tax assets. For public companies, this update will be effective for interim and annual periods beginning after December 15, 2017, and is to be applied on a modified retrospective basis. Upon the effective date, the fair value of the Company's loan portfolio will be presented using an exit price method. The Company has concluded that the remaining requirements of this update are not expected to have a material impact on the Company's consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The guidance in the update supersedes the requirements in ASC Topic 840, Leases. The guidance is intended to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet for leases with terms of more than 12 months. For public companies, this update will be effective for interim and annual periods beginning after December 15, 2018, and is to be applied on a modified retrospective basis. The Company currently leases its main location and space for six other branch offices and operational departments under operating leases that will result in recognition of lease assets and lease liabilities on the consolidated balance sheets under the update. The amount of assets and liabilities added to the balance sheet are not expected to have a material impact on the Company's consolidated financial statements per preliminary estimates. In March 2016, the FASB issued ASU No. 2016-09, Compensation—Stock Compensation (Topic 718). The guidance in this update simplifies several aspects of accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The guidance also allows an entity to make an entity-wide accounting policy election to either estimate expected forfeitures or account for forfeitures as they occur. For public companies, the update was effective for annual periods beginning after December 15, 2016. Portions of the amended guidance were to be applied using a modified retrospective transition method, and others required prospective application. Upon adoption of this update on January 1, 2017, the Company made the accounting policy election to account for forfeitures as they occur. This resulted in no effect on the Company's consolidated financial statements, as prior stock-based compensation expense assumed no expected forfeitures. Upon adoption, the Company changed the calculation of the assumed proceeds of the treasury stock method on a prospective basis to eliminate deferred taxes from the calculation. The net impact on the income statement is dependent upon the change in the Company's stock price from grant date to vesting date and cannot be predicted by management with any certainty. The requirement to report the excess tax benefit or shortfall related to settlements of share-based payment awards in earnings as an increase or decrease to tax expense, rather than within additional paid-in-capital, has been applied to settlements occurring on or after January 1, 2017, and the impact of applying that guidance reduced reported income tax expense by $285 for the year ended December 31, 2017. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326). The amendments in this update require a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial assets to present the net carrying value at the amount expected to be collected on the financial assets. The income statement reflects the measurement of credit losses for newly recognized financial assets, as well as the expected increases or decreases of expected credit losses that have taken place during the period. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectibility of the reported amount of financial assets. An entity must use judgment in determining the relevant information and estimation methods that are appropriate in its circumstances. The allowance for credit losses for purchased financial assets with a more-than-insignificant amount of credit deterioration since origination that are measured at amortized cost basis is determined in a similar manner to other financial assets measured at amortized cost basis; however, the initial allowance for credit losses is added to the purchase price rather than being reported as a credit loss expense. Only subsequent changes in the allowance for credit losses are recorded as a credit loss expense for these assets. Off-balance-sheet arrangements such as commitments to extend credit, guarantees, and standby letters of credit that are not considered derivatives under ASC 815 and are not unconditionally cancellable are also within the scope of this update. Credit losses relating to available for sale debt securities should be recorded through an allowance for credit losses. For public companies, the update is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. All entities may adopt the amendments in this update earlier as of fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. An entity will apply the amendments in this update on a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The Company does not plan to early adopt this standard, but is currently planning for the implementation. It is too early to assess the impact that this guidance will have on the Company's consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The amendments in this update provide guidance for eight specific cash flow classification issues for which current guidance is unclear or does not exist, thereby reducing diversity in practice. For public companies, the update is effective for annual periods beginning after December 15, 2017, with early adoption permitted. The Company's early adoption of the update as of January 1, 2017, did not have a material impact on the Company's consolidated financial statements. In March 2017, the FASB issued ASU No. 2017-08, Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities . The amendments in this update shorten the amortization period for certain purchased callable debt securities held at a premium. The amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. For public companies, the update is effective for annual periods beginning after December 15, 2018, and is to be applied on a modified retrospective basis with a cumulative-effect adjustment directly to retained earnings as of the beginning of the adoption period. Early adoption is permitted, including adoption in an interim period. The Company adopted the amendments in the fourth quarter of 2017, and it had no impact on the Company's consolidated financial statements. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities . The amendments in this update better align an entity's risk management activities and financial reporting for hedging relationships through changes to both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results. For public companies, the update is effective for annual periods beginning after December 15, 2018, with early adoption permitted, including in an interim period. The amendments' presentation and disclosure guidance is required on a prospective basis. The Company is currently assessing the impact of this guidance, but does not expect the guidance to have a material impact on the Company's consolidated financial statements. In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendment in this update allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the December 22, 2017, enactment

Earnings per Common Share (Note

Earnings per Common Share (Notes)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	Earnings per Common Share The calculation of earnings per common share and diluted earnings per common share is presented below for the years ended December 31, 2017 , 2016 and 2015 . (in thousands, except per share data) 2017 2016 2015 Net income $ 23,070 $ 23,016 $ 21,742 Weighted average common shares outstanding 16,194 16,117 16,050 Weighted average effect of restricted stock units outstanding 141 54 46 Diluted weighted average common shares outstanding 16,335 16,171 16,096 Basic earnings per common share $ 1.42 $ 1.43 $ 1.35 Diluted earnings per common share $ 1.41 $ 1.42 $ 1.35 Number of anti-dilutive common stock equivalents excluded from diluted earnings per share computation — 102 140

Investment securities (Notes)

Investment securities (Notes)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investments in Debt and Marketable Equity Securities Disclosure [Text Block]	Investment Securities The following tables show the amortized cost, gross unrealized gains and losses and fair value of investment securities, by investment security type as of December 31, 2017 and 2016 . 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Securities available for sale: State and political subdivisions $ 146,331 $ 928 $ (946 ) $ 146,313 Collateralized mortgage obligations (1) 162,631 28 (2,727 ) 159,932 Mortgage-backed securities (1) 60,956 20 (547 ) 60,429 Asset-backed securities (2) 45,539 8 (352 ) 45,195 Trust preferred security 2,134 — (128 ) 2,006 Corporate notes 30,278 331 (265 ) 30,344 $ 447,869 $ 1,315 $ (4,965 ) $ 444,219 Securities held to maturity: State and political subdivisions $ 45,527 $ 460 $ (97 ) $ 45,890 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Securities available for sale: U.S. government agencies and corporations $ 2,524 $ 69 $ — $ 2,593 State and political subdivisions 64,551 376 (591 ) 64,336 Collateralized mortgage obligations (1) 103,038 255 (1,343 ) 101,950 Mortgage-backed securities (1) 80,614 341 (797 ) 80,158 Trust preferred security 1,784 — (534 ) 1,250 Corporate notes 10,326 25 (1 ) 10,350 $ 262,837 $ 1,066 $ (3,266 ) $ 260,637 Securities held to maturity: State and political subdivisions $ 48,386 $ 70 $ (667 ) $ 47,789 (1) All collateralized mortgage obligations and mortgage-backed securities consist of residential mortgage pass-through securities guaranteed by FHLMC or FNMA, real estate mortgage investment conduits guaranteed by FNMA, FHLMC or GNMA, and commercial mortgage pass-through securities guaranteed by the SBA. (2) Pass-through asset-backed securities guaranteed by the SBA, representing participating interests in pools of long-term debentures issued by state and local development companies certified by the SBA. Investment securities with an amortized cost of approximately $120,338 and $141,995 as of December 31, 2017 and 2016 , respectively, were pledged to secure access to the Federal Reserve discount window, for public fund deposits, and for other purposes as required or permitted by law or regulation. The amortized cost and fair value of investment securities available for sale as of December 31, 2017 , by contractual maturity, are shown below. Certain securities have call features that allow the issuer to call the securities prior to maturity. Expected maturities may differ from contractual maturities for collateralized mortgage obligations, mortgage-backed securities and asset-backed securities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Therefore, collateralized mortgage obligations, mortgage-backed securities and asset-backed securities are not included in the maturity categories within the following maturity summary. 2017 Amortized Cost Fair Value Due in one year or less $ 110 $ 110 Due after one year through five years 2,355 2,358 Due after five years through ten years 41,525 41,710 Due after ten years 134,753 134,485 178,743 178,663 Collateralized mortgage obligations, mortgage-backed and asset-backed securities 269,126 265,556 $ 447,869 $ 444,219 The amortized cost and fair value of investment securities held to maturity as of December 31, 2017 , by contractual maturity, are shown below. Certain securities have call features that allow the issuer to call the securities prior to maturity. 2017 Amortized Cost Fair Value Due after one year through five years $ 1,594 $ 1,588 Due after five years through ten years 26,621 26,798 Due after ten years 17,312 17,504 $ 45,527 $ 45,890 The details of the sales of investment securities for the years ended December 31, 2017 , 2016 and 2015 are summarized in the following table. 2017 2016 2015 Proceeds from sales $ 108,584 $ 3,054 $ 16,946 Gross gains on sales 752 66 54 Gross losses on sales 426 — 7 The following tables show the fair value and gross unrealized losses, aggregated by investment type and length of time that individual securities have been in a continuous loss position, as of December 31, 2017 and 2016 . 2017 Less than 12 months 12 months or longer Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Securities available for sale: State and political subdivisions $ 86,750 $ (946 ) $ — $ — $ 86,750 $ (946 ) Collateralized mortgage obligations 107,526 (1,583 ) 46,396 (1,144 ) 153,922 (2,727 ) Mortgage-backed securities 53,974 (547 ) — — 53,974 (547 ) Asset-backed securities 38,652 (352 ) — — 38,652 (352 ) Trust preferred security — — 2,006 (128 ) 2,006 (128 ) Corporate notes 14,735 (265 ) — — 14,735 (265 ) $ 301,637 $ (3,693 ) $ 48,402 $ (1,272 ) $ 350,039 $ (4,965 ) Securities held to maturity: State and political subdivisions $ 12,611 $ (70 ) $ 1,740 $ (27 ) $ 14,351 $ (97 ) 2016 Less than 12 months 12 months or longer Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Securities available for sale: State and political subdivisions $ 34,903 $ (591 ) $ — $ — $ 34,903 $ (591 ) Collateralized mortgage obligations 75,771 (1,255 ) 2,538 (88 ) 78,309 (1,343 ) Mortgage-backed securities 60,221 (797 ) — — 60,221 (797 ) Trust preferred security — — 1,250 (534 ) 1,250 (534 ) Corporate notes 1,499 (1 ) — — 1,499 (1 ) $ 172,394 $ (2,644 ) $ 3,788 $ (622 ) $ 176,182 $ (3,266 ) Securities held to maturity: State and political subdivisions $ 32,976 $ (458 ) $ 3,968 $ (209 ) $ 36,944 $ (667 ) As of December 31, 2017 , the available for sale and held to maturity investment securities with unrealized losses included 146 state and political subdivision securities, 38 collateralized mortgage obligations, 15 mortgage-backed securities, six asset-backed securities, one trust preferred security and four corporate notes. The Company believes the unrealized losses on investment securities available for sale and held to maturity as of December 31, 2017 were due to market conditions, including interest rate fluctuations, rather than reduced estimated cash flows. The Company does not intend to sell these securities, does not anticipate that these securities will be required to be sold before anticipated recovery, and expects full principal and interest to be collected. Therefore, the Company does not consider these investments to have OTTI as of December 31, 2017 .

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses (Notes)	12 Months Ended
	Dec. 31, 2017
Loans and Allowance for Loan Losses [Abstract]
Loans, Notes, Trade and Other Receivables Disclosure [Text Block]	Loans and Allowance for Loan Losses Loans consisted of the following segments as of December 31, 2017 and 2016 . 2017 2016 Commercial $ 347,482 $ 334,014 Real estate: Construction, land and land development 207,451 205,610 1-4 family residential first mortgages 51,044 47,184 Home equity 13,811 18,057 Commercial 886,114 788,000 Consumer and other 6,363 8,355 1,512,265 1,401,220 Net unamortized fees and costs (1,765 ) (1,350 ) $ 1,510,500 $ 1,399,870 The loan portfolio included $997,642 and $911,067 of fixed-rate loans and $514,623 and $490,153 of variable-rate loans as of December 31, 2017 and 2016 , respectively. Real estate loans of approximately $810,000 and $680,000 were pledged as security for FHLB advances as of December 31, 2017 and 2016 , respectively. The Company has had, and may be expected to have in the future, banking transactions in the ordinary course of business with directors, executive officers, their immediate families, and affiliated companies in which they are principal stockholders or executive officers (commonly referred to as related parties), all of which have been originated, in the opinion of management, on the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with unrelated parties. Loan transactions with related parties were as follows for the years ended December 31, 2017 and 2016 . 2017 2016 Balance, beginning of year $ 191,697 $ 138,706 New loans 28,975 60,712 Repayments (55,575 ) (7,721 ) Balance, end of year $ 165,097 $ 191,697 The following table summarizes the recorded investment in impaired loans by segment, broken down by loans with no related allowance and loans with a related allowance and the amount of that allowance as of December 31, 2017 and 2016 . December 31, 2017 December 31, 2016 Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance Related Allowance With no related allowance recorded: Commercial $ — $ — $ — $ 35 $ 35 $ — Real estate: Construction, land and land development — — — — — — 1-4 family residential first mortgages 91 91 — 108 108 — Home equity 172 172 — 41 41 — Commercial 220 220 — 335 335 — Consumer and other — — — — — — 483 483 — 519 519 — With an allowance recorded: Commercial — — — 91 91 91 Real estate: Construction, land and land development — — — — — — 1-4 family residential first mortgages — — — — — — Home equity 21 21 21 276 276 276 Commercial 118 118 118 136 136 136 Consumer and other — — — — — — 139 139 139 503 503 503 Total: Commercial — — — 126 126 91 Real estate: Construction, land and land development — — — — — — 1-4 family residential first mortgages 91 91 — 108 108 — Home equity 193 193 21 317 317 276 Commercial 338 338 118 471 471 136 Consumer and other — — — — — — Total impaired loans $ 622 $ 622 $ 139 $ 1,022 $ 1,022 $ 503 The balance of impaired loans at December 31, 2017 was composed of loans to five different borrowers, and the balance of impaired loans at December 31, 2016 was composed of loans to ten different borrowers. As of December 31, 2017 , $450 of total impaired loans to four of the borrowers were also considered impaired as of December 31, 2016 . The Company has no commitments to advance additional funds on any of the impaired loans. The following table summarizes the average recorded investment and interest income recognized on impaired loans by segment for the years ended December 31, 2017 , 2016 and 2015 . December 31, 2017 December 31, 2016 December 31, 2015 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized With no related allowance recorded: Commercial $ 19 $ — $ 3 $ — $ 116 $ — Real estate: Construction, land and land development — — 8 — 259 10 1-4 family residential first mortgages 99 — 212 1 311 1 Home equity 39 2 3 — — — Commercial 276 — 393 — 952 — Consumer and other — — — — 2 — 433 2 619 1 1,640 11 With an allowance recorded: Commercial 60 7 127 — 204 2 Real estate: Construction, land and land development — — — — 190 6 1-4 family residential first mortgages — — — — — — Home equity 177 1 263 — 237 — Commercial 127 — 145 — 164 — Consumer and other — — — — — — 364 8 535 — 795 8 Total: Commercial 79 7 130 — 320 2 Real estate: Construction, land and land development — — 8 — 449 16 1-4 family residential first mortgages 99 — 212 1 311 1 Home equity 216 3 266 — 237 — Commercial 403 — 538 — 1,116 — Consumer and other — — — — 2 — Total impaired loans $ 797 $ 10 $ 1,154 $ 1 $ 2,435 $ 19 Interest income forgone on impaired loans was $47 , $72 and $128 , respectively, during the years ended December 31, 2017 , 2016 and 2015 . The following tables provide an analysis of the payment status of the recorded investment in loans as of December 31, 2017 and 2016 . December 31, 2017 30-59 Days Past Due 60-89 Days Past Due 90 Days or More Past Due Total Past Due Current Nonaccrual Loans Total Loans Commercial $ 40 $ 20 $ — $ 60 $ 347,422 $ — $ 347,482 Real estate: Construction, land and land development — — — — 207,451 — 207,451 1-4 family residential first mortgages — 75 — 75 50,878 91 51,044 Home equity — — — — 13,618 193 13,811 Commercial — — — — 885,776 338 886,114 Consumer and other — — — — 6,363 — 6,363 Total $ 40 $ 95 $ — $ 135 $ 1,511,508 $ 622 $ 1,512,265 December 31, 2016 30-59 Days Past Due 60-89 Days Past Due 90 Days or More Past Due Total Past Due Current Nonaccrual Loans Total Loans Commercial $ 109 $ — $ — $ 109 $ 333,779 $ 126 $ 334,014 Real estate: Construction, land and land development — — — — 205,610 — 205,610 1-4 family residential first mortgages 64 — — 64 47,012 108 47,184 Home equity — — — — 17,740 317 18,057 Commercial — — — — 787,529 471 788,000 Consumer and other — — — — 8,355 — 8,355 Total $ 173 $ — $ — $ 173 $ 1,400,025 $ 1,022 $ 1,401,220 TDR loans totaled $220 and $426 as of December 31, 2017 and 2016 , respectively, and were included in the nonaccrual category. There were no loan modifications considered to be TDR that occurred during the year ended December 31, 2017 or December 31, 2016 , and three loan modifications considered to be TDR that occurred during the year ended December 31, 2015 . The pre- and post-modification recorded investment in TDR loans that have occurred during the years ended December 31, 2017 , 2016 and 2015 , totaled $0 , $0 and $149 , respectively. The financial impact of charge-offs or specific reserves for these modified loans was immaterial. The recorded investment in TDR loans that have been modified within the twelve months ended December 31, 2017 , 2016 and 2015 , which have subsequently had a payment default, totaled $0 , $0 and $110 , respectively. A TDR loan is considered to have a payment default when it is past due 30 days or more. The following tables show the recorded investment in loans by credit quality indicator and loan segment as of December 31, 2017 and 2016 . December 31, 2017 Pass Watch Substandard Doubtful Total Commercial $ 344,586 $ 901 $ 1,995 $ — $ 347,482 Real estate: Construction, land and land development 206,719 732 — — 207,451 1-4 family residential first mortgages 49,905 890 249 — 51,044 Home equity 13,466 54 291 — 13,811 Commercial 856,789 20,574 8,751 — 886,114 Consumer and other 6,327 36 — — 6,363 Total $ 1,477,792 $ 23,187 $ 11,286 $ — $ 1,512,265 December 31, 2016 Pass Watch Substandard Doubtful Total Commercial $ 329,366 $ 3,303 $ 1,345 $ — $ 334,014 Real estate: Construction, land and land development 204,572 — 1,038 — 205,610 1-4 family residential first mortgages 46,278 798 108 — 47,184 Home equity 17,646 — 411 — 18,057 Commercial 769,010 18,392 598 — 788,000 Consumer and other 8,355 — — — 8,355 Total $ 1,375,227 $ 22,493 $ 3,500 $ — $ 1,401,220 All loans are subject to the assessment of a credit quality indicator. Risk ratings are assigned for each loan at the time of approval, and they change as circumstances dictate during the term of the loan. The Company utilizes a 9-point risk rating scale as shown below, with ratings 1 - 5 included in the Pass column, rating 6 included in the Watch column, ratings 7 - 8 included in the Substandard column, and rating 9 included in the Doubtful column. All loans classified as impaired that are included in the specific evaluation of the allowance for loan losses are included in the Substandard column along with all other loans with ratings of 7 - 8. Risk rating 1: The loan is secured by cash equivalent collateral. Risk rating 2: The loan is secured by properly margined marketable securities, bonds or cash surrender value of life insurance. Risk rating 3: The borrower is in strong financial condition and has strong debt service capacity. The loan is performing as agreed, and the financial characteristics and trends of the borrower exceed industry statistics. Risk rating 4: The borrower’s financial condition is satisfactory and stable. The borrower has satisfactory debt service capacity, and the loan is well secured. The loan is performing as agreed, and the financial characteristics and trends fall in line with industry statistics. Risk rating 5: The borrower’s financial condition is less than satisfactory. The loan is still generally paying as agreed, but strained cash flow may cause some slowness in payments. The collateral values adequately preclude loss on the loan. Financial characteristics and trends lag industry statistics. There may be noncompliance with loan covenants. Risk rating 6: The borrower’s financial condition is deficient. Payment delinquencies may be more common. Collateral values still protect from loss, but margins are narrow. The loan may be reliant on secondary sources of repayment, including liquidation of collateral and guarantor support. Risk rating 7: The loan is inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. Well-defined weaknesses exist that jeopardize the liquidation of the debt. The Company is inadequately protected by the valuation or paying capacity of the collateral pledged. If deficiencies are not corrected, there is a distinct possibility that a loss will be sustained. Risk rating 8: All the characteristics of rating 7 exist with the added condition that the loan is past due more than 90 days or there is reason to believe the Company will not receive its principal and interest according to the terms of the loan agreement. Risk rating 9: All the weaknesses inherent in risk ratings 7 and 8 exist with the added condition that collection or liquidation, on the basis of currently known facts, conditions and values, is highly questionable and improbable. A loan reaching this category would most likely be charged off. Credit quality indicators for all loans and the Company’s risk rating process are dynamic and updated on a continuous basis. Risk ratings are updated as circumstances that could affect the repayment of an individual loan are brought to management’s attention through an established monitoring process. Individual lenders initiate changes as appropriate for ratings 1 through 5, and changes for ratings 6 through 9 are initiated via communications with management. The likelihood of loss increases as the risk rating increases and is generally preceded by a loan appearing on the Watch List, which consists of all loans with a risk rating of 6 or worse. Written action plans with firm target dates for resolution of identified problems are maintained and reviewed on a quarterly basis for all segments of loans included on the Watch List. In addition to the Company’s internal credit monitoring practices and procedures, an outsourced independent credit review function is in place to further assess assigned internal risk classifications and monitor compliance with internal lending policies and procedures. In all portfolio segments, the primary risks are that a borrower’s income stream diminishes to the point that it is not able to make scheduled principal and interest payments and any collateral securing the loan declines in value. The risk of declining collateral values is present for most types of loans. Commercial loans consist primarily of loans to businesses for various purposes, including revolving lines to finance current operations, inventory and accounts receivable, and capital expenditure loans to finance equipment and other fixed assets. These loans generally have short maturities, have either adjustable or fixed interest rates, and are either unsecured or secured by inventory, accounts receivable and/or fixed assets. For commercial loans, the primary source of repayment is from the operation of the business. Real estate loans include various types of loans for which the Company holds real property as collateral, and consist of loans on commercial properties and single and multifamily residences. Real estate loans are typically structured to mature or reprice every 5 to 10 years with payments based on amortization periods up to 30 years. The majority of construction loans are to contractors and developers for construction of commercial buildings or residential real estate. These loans typically have maturities up to 24 months. The Company’s loan policy includes minimum appraisal and other credit guidelines. Consumer loans include loans extended to individuals for household, family and other personal expenditures not secured by real estate. The majority of the Company’s consumer lending is for vehicles, consolidation of personal debts and household improvements. The repayment source for consumer loans, including 1-4 family residential mortgages and home equity loans, is typically wages. The following tables detail changes in the allowance for loan losses by segment for the years ended December 31, 2017 , 2016 and 2015 . 2017 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Beginning balance $ 3,881 $ 2,639 $ 317 $ 478 $ 8,697 $ 100 $ 16,112 Charge-offs (199 ) — — (176 ) — — (375 ) Recoveries 232 398 15 28 13 7 693 Provision (1) (48 ) (824 ) (13 ) (144 ) 1,060 (31 ) — Ending balance $ 3,866 $ 2,213 $ 319 $ 186 $ 9,770 $ 76 $ 16,430 2016 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Beginning balance $ 4,369 $ 2,338 $ 508 $ 481 $ 7,254 $ 17 $ 14,967 Charge-offs (125 ) (141 ) (93 ) — — (47 ) (406 ) Recoveries 218 217 59 36 13 8 551 Provision (1) (581 ) 225 (157 ) (39 ) 1,430 122 1,000 Ending balance $ 3,881 $ 2,639 $ 317 $ 478 $ 8,697 $ 100 $ 16,112 2015 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Beginning balance $ 4,415 $ 2,151 $ 466 $ 534 $ 6,013 $ 28 $ 13,607 Charge-offs (408 ) — (23 ) (2 ) — (6 ) (439 ) Recoveries 579 250 7 87 12 14 949 Provision (1) (217 ) (63 ) 58 (138 ) 1,229 (19 ) 850 Ending balance $ 4,369 $ 2,338 $ 508 $ 481 $ 7,254 $ 17 $ 14,967 (1) The negative provisions for the various segments are either related to the decline in outstanding balances in each of those portfolio segments during the time periods disclosed and/or improvement in the credit quality factors related to those portfolio segments. The following tables show a breakdown of the allowance for loan losses disaggregated on the basis of impairment analysis method by segment as of December 31, 2017 and 2016 . December 31, 2017 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Ending balance: Individually evaluated for impairment $ — $ — $ — $ 21 $ 118 $ — $ 139 Collectively evaluated for impairment 3,866 2,213 319 165 9,652 76 16,291 Total $ 3,866 $ 2,213 $ 319 $ 186 $ 9,770 $ 76 $ 16,430 December 31, 2016 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Ending balance: Individually evaluated for impairment $ 91 $ — $ — $ 276 $ 136 $ — $ 503 Collectively evaluated for impairment 3,790 2,639 317 202 8,561 100 15,609 Total $ 3,881 $ 2,639 $ 317 $ 478 $ 8,697 $ 100 $ 16,112 The following tables show the recorded investment in loans, exclusive of unamortized fees and costs, disaggregated on the basis of impairment analysis method by segment as of December 31, 2017 and 2016 . December 31, 2017 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Ending balance: Individually evaluated for impairment $ — $ — $ 91 $ 193 $ 338 $ — $ 622 Collectively evaluated for impairment 347,482 207,451 50,953 13,618 885,776 6,363 1,511,643 Total $ 347,482 $ 207,451 $ 51,044 $ 13,811 $ 886,114 $ 6,363 $ 1,512,265 December 31, 2016 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Ending balance: Individually evaluated for impairment $ 126 $ — $ 108 $ 317 $ 471 $ — $ 1,022 Collectively evaluated for impairment 333,888 205,610 47,076 17,740 787,529 8,355 1,400,198 Total $ 334,014 $ 205,610 $ 47,184 $ 18,057 $ 788,000 $ 8,355 $ 1,401,220

Premises and Equipment, Net (No

Premises and Equipment, Net (Notes)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment Disclosure [Text Block]	Premises and Equipment, Net Premises and equipment consisted of the following as of December 31, 2017 and 2016 . 2017 2016 Land $ 4,323 $ 4,323 Buildings 14,423 14,344 Leasehold improvements 3,880 3,843 Furniture and equipment 7,946 7,637 30,572 30,147 Accumulated depreciation (7,550 ) (6,833 ) $ 23,022 $ 23,314

Deposits (Notes)

Deposits (Notes)	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Deposit Liabilities Disclosures [Text Block]	Deposits The scheduled maturities of time deposits were as follows as of December 31, 2017 . 2018 $ 133,323 2019 18,698 2020 8,451 2021 3,396 2022 5,789 $ 169,657 Time deposits as of December 31, 2017 and 2016 , included $100,091 and $53,821 , respectively, of Certificate of Deposit Account Registry Service deposits, which is a program that coordinates, on a reciprocal basis, a network of banks to spread deposits exceeding the FDIC insurance coverage limits out to numerous institutions in order to provide insurance coverage for all participating deposits. Also included in total deposits as of December 31, 2017 and 2016 , were $117,990 and $83,089 , respectively, of Insured Cash Sweep (ICS) interest-bearing checking and $213,587 and $155,957 , respectively, of ICS money market deposits. These are also reciprocal programs providing insurance coverage for all participating deposits.

Subordinated Notes (Notes)

Subordinated Notes (Notes)	12 Months Ended
	Dec. 31, 2017
Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust [Abstract]
Subordinated Borrowings Disclosure [Text Block]	Subordinated Notes On July 18, 2003, the Company issued $20,619 in junior subordinated debentures to the Company’s subsidiary trust, West Bancorporation Capital Trust I. The junior subordinated debentures are senior to the Company’s common stock. As a result, the Company must make payments on the junior subordinated debentures (and the related trust preferred securities) before any dividends can be paid on its common stock, and, in the event of the Company’s bankruptcy, dissolution or liquidation, the holders of the debentures must be satisfied before any distribution can be made to the holders of the common stock. The Company has the right to defer distributions on the junior subordinated debentures (and the related trust preferred securities) for up to five years , during which time no dividends may be paid to holders of the Company’s common stock. The junior subordinated debentures have a 30-year term, do not require any principal amortization, and are callable at the issuer’s option. The interest rate is a variable rate based on the 3-month LIBOR plus 3.05 percent . At December 31, 2017 , the interest rate was 4.74 percent . Interest is payable quarterly , unless deferred. The Company has never deferred an interest payment. The effective cost of the junior subordinated debentures at December 31, 2017 , including amortization of issuance costs, was 4.81 percent . Holders of the trust preferred securities associated with the junior subordinated debentures have no voting rights, are unsecured, and rank junior in priority to all the Company’s indebtedness and senior to the Company’s common stock. The junior subordinated debentures are reported net of unamortized debt issuance costs of $207 and $221 as of December 31, 2017 and 2016 , respectively. The Company also has a forward-starting interest rate swap contract that effectively converts $20,000 of the variable-rate junior subordinated debentures to a fixed rate beginning on September 30, 2018. See Note 10 for additional information on the interest rate swap. In addition, the junior subordinated debentures qualify as Tier 1 capital of the Company for regulatory purposes.

Federal Home Loan Bank Advances

Federal Home Loan Bank Advances (Notes)	12 Months Ended
	Dec. 31, 2017
Advances from Federal Home Loan Banks [Abstract]
Federal Home Loan Bank Advances, Disclosure [Text Block]	Federal Home Loan Bank and Other Borrowings The following table presents the terms of all FHLB long-term advances as of December 31, 2017 and 2016 . December 31, 2017 December 31, 2016 Maturity Interest Effective Interest Effective Date Variable/Fixed Rate Rate (1) Balance Rate Rate (1) Balance 1/29/2018 Fixed — — $ — 2.70 % 2.70 % $ 25,000 12/23/2019 Variable 1.93% 3.90% 25,000 1.28 % 3.26 % 25,000 6/22/2020 Variable 1.95% 4.09% 25,000 1.30 % 3.45 % 25,000 9/21/2020 Variable 1.95% 4.44% 30,000 1.30 % 4.44 % 30,000 80,000 105,000 Discount for modification (3,618 ) (5,114 ) Total FHLB advances, net of discount $ 76,382 $ 99,886 (1) The effective interest rate for the variable-rate advances includes the effects of the discount fee amortization and interest rate swaps, if applicable. Three of the FHLB advances totaling $80,000 were modified on December 21, 2012, to extend their terms and to convert the borrowings to a variable rate that is tied to 3-month LIBOR. In connection with these modifications, the Company paid a prepayment fee of $11,152 , which is being amortized and recognized as interest expense over the remaining terms of the advances. For the years ended December 31, 2017 , 2016 and 2015 , the Company amortized $1,496 , $1,501 and $1,497 , respectively, of interest expense related to the discount. Interest is payable quarterly on the FHLB advances. The Company also has an interest rate swap contract that effectively converts the $30,000 variable-rate advance to a fixed-rate advance. See Note 10 for additional information on the interest rate swap. The FHLB advances are collateralized by FHLB stock and real estate loans, as required by the FHLB’s collateral policy. West Bank had additional borrowing capacity of approximately $384,000 at the FHLB as of December 31, 2017 . As of December 31, 2017 , West Bank had arrangements that would allow it to borrow $67,000 in unsecured federal funds lines of credit at correspondent banks that are available under the correspondent banks’ normal terms. The lines have no stated expiration dates. As of December 31, 2017 , there were no amounts outstanding under these arrangements.

Long-term debt (Notes)

Long-term debt (Notes)	12 Months Ended
	Dec. 31, 2017
Debt Instruments [Abstract]
Long-term Debt [Text Block]	Long-Term Debt On May 25, 2017, the Company entered into a credit agreement with a commercial bank and borrowed $25,000 . This credit agreement replaced a prior credit agreement with the same commercial bank that had a remaining outstanding principal balance of $3,000. The additional borrowing was used to make a capital injection into the Company's subsidiary, West Bank. Principal and interest under the term note are payable quarterly over five years . Required quarterly principal payments are $625 , with the balance due at maturity. The Company may make additional principal payments without penalty. The interest rate is variable at 1.95 percent plus 30-day LIBOR , which totaled 3.33 percent as of December 31, 2017 . In the event of default, the unaffiliated commercial bank may accelerate payment of the loan. The outstanding balance was $22,500 as of December 31, 2017 . The note is secured by 100 percent of West Bank’s stock. The prior note that was replaced by this credit agreement had an outstanding balance of $4,600 as of December 31, 2016 . In June 2013, a portion of the property purchased for the branch office in Coralville, Iowa, was financed with a $765 , nine year variable-payment contract with a fixed interest rate of 1.25 percent . The outstanding balance on the contract was $417 and $529 as of December 31, 2017 and 2016 , respectively. Future required principal payments for long-term debt as of December 31, 2017 are shown in the table below. 2018 $ 2,614 2019 2,615 2020 2,616 2021 2,537 2022 12,535 $ 22,917

Derivatives (Notes)

Derivatives (Notes)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure [Text Block]	Derivatives The Company uses interest rate swap agreements to manage the interest rate risk related to the variability of interest payments. The Company has variable-rate FHLB advances and junior subordinated notes, which create exposure to variability in interest payments due to changes in interest rates. The notional amounts of the interest rate swaps do not represent amounts exchanged by the counterparties, but rather, the notional amount is used to determine, along with other terms of the derivative, the amounts to be exchanged between the counterparties. The Company has two interest rate swaps that effectively convert variable-rate FHLB advances and junior subordinated notes to fixed-rate debt. The swap transactions were designated as cash flow hedges of the changes in cash flows attributable to changes in LIBOR, the benchmark interest rate being hedged, associated with the interest payments made on the underlying debt with quarterly interest rate reset dates. An interest rate swap, with a notional amount of $30,000 , became effective in December 2015. In October 2016, the Company entered into a forward-starting interest rate swap transaction with a notional amount of $20,000 . The forward starting date of this swap is September 30, 2018. Interest rate swaps, with a total notional amount of $70,000 , were terminated in prior years, subject to termination fees totaling $541 . The termination fees are being reclassified from accumulated other comprehensive income to interest expense over the remaining life of the underlying cash flows, through June 2020. At the inception of each hedge transaction, the Company represented that the underlying principal balance would remain outstanding throughout the hedge transaction, making it probable that sufficient LIBOR-based interest payments would exist through the maturity date of the swaps. The cash flow hedges were determined to be fully effective during the remaining terms of the swaps. Therefore, the aggregate fair value of the swaps is recorded in other assets or other liabilities with changes in market value recorded in OCI, net of deferred taxes. See Note 17 for additional fair value information and disclosures. The amounts included in AOCI will be reclassified to interest expense should the hedge no longer be considered effective. No amount of ineffectiveness was included in net income for the years ended December 31, 2017 , 2016 and 2015 , and the Company estimates there will be approximately $278 of cash payments and reclassification from AOCI to interest expense through December 31, 2018 . The Company will continue to assess the effectiveness of the hedges on a quarterly basis. The Company is exposed to credit risk in the event of nonperformance by the interest rate swaps counterparty. The Company minimizes this risk by entering into derivative contracts with only large, stable financial institutions, and the Company has not experienced, and does not expect, any losses from counterparty nonperformance on the interest rate swaps. The Company monitors counterparty risk in accordance with the provisions of FASB ASC 815. In addition, the interest rate swap agreements contains language outlining collateral-pledging requirements for each counterparty. Collateral must be posted when the market value exceeds certain threshold limits. Derivative contracts are executed with a Credit Support Annex, which is a bilateral ratings-sensitive agreement that requires collateral postings at established credit threshold levels. These agreements protect the interests of the Company and its counterparties should either party suffer a credit rating deterioration. The Company was required to pledge $210 and $470 of cash as collateral to the counterparty as of December 31, 2017 and 2016 , respectively. The Company’s counterparty was required to pledge $980 and $1,070 at December 31, 2017 and 2016 , respectively. The table below identifies the balance sheet category and fair values of the Company’s derivative instruments designated as cash flow hedges as of December 31, 2017 and 2016 . Notional Amount Fair Value Balance Sheet Category Weighted Average Receive Rate Weighted Average Pay Rate Maturity December 31, 2017 Interest rate swap $ 30,000 $ (86 ) Other Liabilities 1.95 % 2.52 % 9/21/2020 Interest rate swap (1) 20,000 895 Other Assets — % 4.81 % 9/30/2026 December 31, 2016 Interest rate swap $ 30,000 $ (496 ) Other Liabilities 1.30 % 2.52 % 9/21/2020 Interest rate swap (1) 20,000 1,068 Other Assets — % 4.81 % 9/30/2026 (1) This swap is a forward starting swap with a weighted average pay rate of 4.81 percent beginning September 30, 2018. No interest payments are required related to this swap until December 30, 2018. The following table identifies the pretax gains (losses) recognized on the Company’s derivative instruments designated as cash flow hedges for the years ended December 31, 2017 , 2016 and 2015 . Effective Portion Ineffective Portion Amount of Reclassified from AOCI into Income Recognized in Income on Derivatives Pretax Gain (Loss) Recognized in Amount of Amount of OCI Category Loss Category Gain (Loss) 2017 $ (66 ) Interest Expense $ (413 ) Other Income $ — 2016 $ 882 Interest Expense $ (573 ) Other Income $ — 2015 $ (1,144 ) Interest Expense $ (160 ) Other Income $ —

Income Taxes (Notes)

Income Taxes (Notes)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes The Company files income tax returns in the U.S. federal and various state jurisdictions. Income tax returns for the years 2014 through 2017 remain open to examination by federal and state taxing authorities. During the years ended December 31, 2017 , 2016 and 2015 , the Company recognized no material income tax related interest or penalties. No accrued interest or penalties are included in accrued tax expense in the balance sheets as of December 31, 2017 and 2016 . The following table shows the components of income taxes for the years ended December 31, 2017 , 2016 and 2015 . 2017 2016 2015 Current: Federal $ 8,822 $ 8,220 $ 8,057 State 1,713 1,627 1,558 Deferred: Federal 2,527 115 112 State 306 (26 ) (30 ) Income taxes $ 13,368 $ 9,936 $ 9,697 Total income taxes for the years ended December 31, 2017 , 2016 and 2015 , differed from the amounts computed by applying the U.S. federal income tax rate of 35 percent to income before income taxes as shown in the following table. 2017 2016 2015 Amount Percent of Pretax Income Amount Percent of Pretax Income Amount Percent of Pretax Income Computed expected tax expense $ 12,753 35.0 % $ 11,533 35.0 % $ 11,004 35.0 % State income tax expense, net of federal income tax benefit 1,146 3.2 % 1,004 3.0 % 957 3.0 % Tax-exempt interest income (2,023 ) (5.6 )% (1,823 ) (5.5 )% (1,786 ) (5.7 )% Nondeductible interest expense to own tax-exempt securities 152 0.4 % 58 0.2 % 43 0.1 % Tax-exempt increase in cash value of life insurance and gains (336 ) (0.9 )% (381 ) (1.2 )% (254 ) (0.8 )% Stock compensation (261 ) (0.7 )% — — — — Effect of change in federal income tax rate 2,340 6.4 % — — — — Utilization of capital loss carryforwards — — — — (130 ) (0.4 )% Federal income tax credits (410 ) (1.1 )% (405 ) (1.2 )% (275 ) (0.9 )% Other, net 7 — (50 ) (0.1 )% 138 0.5 % Income taxes $ 13,368 36.7 % $ 9,936 30.2 % $ 9,697 30.8 % On December 22, 2017, the Tax Cuts and Jobs Act (the Tax Act) was signed into law. The Tax Act reduced the federal corporate income tax rate from the previous maximum rate of 35 percent to 21 percent effective for 2018 and future years. The enactment of the legislation and the reduction in the federal income tax rate required a one-time reduction in net deferred tax assets and an increase in tax expense of $2,340 as shown in the table above. Net deferred tax assets consisted of the following components as of December 31, 2017 and 2016 . 2017 2016 Deferred tax assets: Allowance for loan losses $ 4,108 $ 6,123 Net unrealized losses on securities available for sale 902 719 Intangibles 101 462 Accrued expenses 176 706 Restricted stock unit compensation 544 446 State net operating loss carryforward 1,379 1,271 Other 86 190 7,296 9,917 Deferred tax liabilities: Deferred loan costs 193 321 Net unrealized gains on interest rate swaps 139 80 Premises and equipment 792 1,027 Other 148 261 1,272 1,689 Net deferred tax assets before valuation allowance 6,024 8,228 Valuation allowance for deferred tax assets (1,379 ) (1,271 ) Net deferred tax assets $ 4,645 $ 6,957 As of December 31, 2017 , the parent Company had approximately $22,989 of Iowa net operating loss carryforwards available to offset future Iowa taxable income. The Company has recorded a valuation allowance against the tax effect of the Iowa net operating loss carryforwards, as management believes it is more likely than not that such carryforwards will expire without being utilized. The Iowa net operating loss carryforwards expire in 2019 and thereafter.

Stock Compensation Plans (Notes

Stock Compensation Plans (Notes)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	Stock Compensation Plans The West Bancorporation, Inc. 2017 Equity Incentive Plan (the 2017 Plan) was approved by the stockholders in April 2017. The 2017 Plan replaced the West Bancorporation, Inc. 2012 Equity Incentive Plan (the 2012 Plan). Upon approval of the 2017 Plan, the 2012 Plan was frozen and no new grants will be made under that plan. Outstanding awards under the 2012 Plan will continue pursuant to their terms and provisions. The Plans are administered by the Compensation Committee of the Board of Directors, which determines the specific individuals who will be granted awards under the 2017 Plan and the type and amount of any such awards. All employees and directors of, and service providers to, the Company and its subsidiary are eligible to become participants in the 2017 Plan, except that nonemployees may not be granted incentive stock options. Under the terms of the 2017 Plan, the Company may grant a total of 800,000 shares of the Company’s common stock as nonqualified and incentive stock options, stock appreciation rights and stock awards. As of December 31, 2017 , 776,000 shares of the Company’s common stock remained available for future awards under the 2017 Plan. Under the 2017 Plan, the Company may grant RSU awards, as determined by the Compensation Committee, that vest upon the completion of future service requirements or specified performance criteria. All RSUs granted through December 31, 2017 under the 2017 and 2012 Plans were at no cost to the participants, and the participants will not be entitled to receive or accrue dividends until the RSUs have vested. Each RSU entitles the participant to receive one share of common stock on the vesting date or upon the participant’s termination due to death or disability, or upon a change in control of the Company if the RSUs are not fully assumed or if the RSUs are assumed and the participant’s employment is thereafter terminated by the Company without cause or by the participant for good reason. If a participant terminates employment prior to the end of the continuous service period other than due to death, disability or retirement, the award is forfeited. If a participant terminates service due to retirement, the RSUs will continue to vest, subject to provisions of the 2017 and 2012 Plans. The following table includes a summary of nonvested RSU activity for the years ended December 31, 2017 , 2016 and 2015 . 2017 2016 2015 Weighted Weighted Weighted Average Average Average Grant Date Grant Date Grant Date Fair Value Fair Value Fair Value (actual amounts, not in thousands) Shares Per Share Shares Per Share Shares Per Share Nonvested shares, beginning balance 307,268 $ 17.46 261,833 $ 16.67 179,699 $ 13.39 Granted 138,500 22.06 141,000 18.44 139,500 19.59 Vested (106,468 ) 16.79 (95,565 ) 16.74 (57,366 ) 13.23 Forfeited — — — — — — Nonvested shares, ending balance 339,300 $ 19.55 307,268 $ 17.46 261,833 $ 16.67 The fair value of RSU awards that vested during 2017 , 2016 and 2015 was $2,371 , $1,730 and $1,118 , respectively. Total compensation costs, including director compensation, recorded for the RSUs were $2,632 , $1,684 , and $1,166 for the years ended December 31, 2017 , 2016 and 2015 , respectively. The tax benefit related to vesting of RSUs totaled $285 , $105 and $155 , respectively, for the years ended December 31, 2017 , 2016 and 2015 . As of December 31, 2017 , there was $3,788 of unrecognized compensation cost related to nonvested RSUs, and the weighted average period over which these remaining costs are expected to be recognized was approximately 1.5 years.

Employee Savings and Stock Owne

Employee Savings and Stock Ownership Plan (Notes)	12 Months Ended
	Dec. 31, 2017
Employee Savings and Stock Ownership Plan [Abstract]
Compensation and Employee Benefit Plans [Text Block]	Employee Savings and Stock Ownership Plan The Company has an employee savings and stock ownership plan covering substantially all of its employees. The plan consists of two components. One component is an employee stock ownership plan. The other component is a discretionary contribution plan. Both components have a qualified cash or deferred arrangement under Internal Revenue Code Section 401(k). Matching and discretionary contributions are determined annually by the Board of Directors. The Company matched 100 percent of the first six percent of employee deferrals and made an annual discretionary contribution of four percent of eligible employee compensation for the years ended December 31, 2017 , 2016 and 2015 . Total matching and discretionary contribution expense for the years ended December 31, 2017 , 2016 and 2015 , totaled $961 , $1,023 and $960 , respectively. As of December 31, 2017 and 2016 , the plan held 294,423 and 327,307 shares, respectively, of the Company’s common stock. These shares are included in the computation of earnings per share. Dividends on shares held in the plan may be reinvested in Company common stock or paid in cash to the participants, at the election of the participants

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Notes)	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Comprehensive Income (Loss) Note [Text Block]	Comprehensive Income (Loss) The following table summarizes the changes in the balances of each component of AOCI, net of tax, for the years ended December 31, 2017 , 2016 and 2015 . Unrealized Accumulated Unrealized Gains Other Gains (Losses) (Losses) on Comprehensive on Securities Derivatives Income (Loss) Balance, December 31, 2014 $ 416 $ (162 ) $ 254 Other comprehensive loss before reclassifications (21 ) (709 ) (730 ) Amounts reclassified from accumulated other comprehensive income (53 ) 99 46 Current period, other comprehensive loss (74 ) (610 ) (684 ) Balance, December 31, 2015 342 (772 ) (430 ) Other comprehensive income (loss) before reclassifications (1,394 ) 547 (847 ) Amounts reclassified from accumulated other comprehensive income (120 ) 355 235 Current period other comprehensive income (loss) (1,514 ) 902 (612 ) Balance, December 31, 2016 (1,172 ) 130 (1,042 ) Other comprehensive loss before reclassifications (697 ) (41 ) (738 ) Amounts reclassified from accumulated other comprehensive income (368 ) 256 (112 ) Current period other comprehensive income (loss) (1,065 ) 215 (850 ) Balance, December 31, 2017 $ (2,237 ) $ 345 $ (1,892 )

Regulatory Capital Requirements

Regulatory Capital Requirements (Notes)	12 Months Ended
	Dec. 31, 2017
Regulatory Capital Requirements [Abstract]
Regulatory Capital Requirements under Banking Regulations [Text Block]	Regulatory Capital Requirements The Company and West Bank are subject to various regulatory capital requirements administered by federal and state banking agencies. Failure to meet minimum capital requirements (as shown in the following table) can result in certain mandatory and possibly additional discretionary actions by regulators which, if undertaken, could have a direct material effect on the Company’s consolidated financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company and West Bank must meet specific capital guidelines that involve quantitative measures of their assets, liabilities and certain off-balance-sheet items as calculated under regulatory requirements. The Company’s and West Bank’s capital amounts and classifications are also subject to qualitative judgments by the regulators about components, risk weightings and other factors. Management believes the Company and West Bank met all capital adequacy requirements to which they were subject as of December 31, 2017 . The Company’s and West Bank’s capital amounts and ratios are presented in the following table as of December 31, 2017 and 2016 . Actual For Capital Adequacy Purposes For Capital Adequacy Purposes With Capital Conservation Buffer To Be Well-Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017: Total Capital (to Risk-Weighted Assets) Consolidated $ 216,420 11.76 % $ 147,169 8.00 % $ 170,164 9.25 % N/A N/A West Bank 235,570 12.82 % 147,049 8.00 % 170,026 9.25 % $ 183,812 10.00 % Tier 1 Capital (to Risk-Weighted Assets) Consolidated 199,990 10.87 % 110,377 6.00 % 133,372 7.25 % N/A N/A West Bank 219,140 11.92 % 110,287 6.00 % 133,263 7.25 % 147,049 8.00 % Common Equity Tier 1 Capital (to Risk-Weighted Assets) Consolidated 179,990 9.78 % 82,783 4.50 % 105,778 5.75 % N/A N/A West Bank 219,140 11.92 % 82,715 4.50 % 105,692 5.75 % 119,478 6.50 % Tier 1 Capital (to Average Assets) Consolidated 199,990 9.60 % 83,326 4.00 % 83,326 4.00 % N/A N/A West Bank 219,140 10.52 % 83,287 4.00 % 83,287 4.00 % 104,109 5.00 % As of December 31, 2016: Total Capital (to Risk-Weighted Assets) Consolidated $ 202,530 11.87 % $ 136,448 8.00 % $ 147,108 8.625 % N/A N/A West Bank 186,118 11.04 % 134,877 8.00 % 145,414 8.625 % $ 168,597 10.00 % Tier 1 Capital (to Risk-Weighted Assets) Consolidated 186,418 10.93 % 102,336 6.00 % 112,996 6.625 % N/A N/A West Bank 170,006 10.08 % 101,158 6.00 % 111,695 6.625 % 134,877 8.00 % Common Equity Tier 1 Capital (to Risk-Weighted Assets) Consolidated 166,418 9.76 % 76,752 4.50 % 87,412 5.125 % N/A N/A West Bank 170,006 10.08 % 75,868 4.50 % 86,406 5.125 % 109,588 6.50 % Tier 1 Capital (to Average Assets) Consolidated 186,418 10.14 % 73,530 4.00 % 73,530 4.00 % N/A N/A West Bank 170,006 9.34 % 72,807 4.00 % 72,807 4.00 % 91,009 5.00 % On January 1, 2015, the Company and West Bank became subject to the rules of the Basel III Rule and related Dodd-Frank Wall Street Reform and Consumer Protection Act changes. The rules included the implementation of a capital conservation buffer that is added to the minimum requirements for capital adequacy purposes. The capital conservation buffer is subject to a three year phase-in period that began January 1, 2016 and will be fully phased-in on January 1, 2019 at 2.5 percent. The required phase-in capital conservation buffer was 1.25 percent during 2017 and 0.625 percent during 2016 . A banking organization with a conservation buffer of less than the required phase-in amount will be subject to limitations on capital distributions, including dividend payments and certain discretionary bonus payments to executive officers. As of December 31, 2017 , the ratios for the Company and West Bank were sufficient to meet the fully phased-in conservation buffer. The ability of the Company to pay dividends to its stockholders is dependent upon dividends paid by its subsidiary, West Bank. There are currently no restrictions on such dividends, besides the general restrictions imposed on all banks by applicable law. The Company’s tangible common equity ratio was 8.42 percent and 8.92 percent at December 31, 2017 and 2016 , respectively. The tangible common equity ratio is computed by dividing total equity less preferred stock and intangible assets by total assets less intangible assets. As of December 31, 2017 and 2016 , the Company had no intangible assets or preferred stock.

Commitments and Contingencies (

Commitments and Contingencies (Notes)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	Commitments and Contingencies The Company leases real estate under a number of noncancelable operating lease agreements. Rent expense related to these leases was $1,344 , $1,293 and $1,741 , for the years ended December 31, 2017 , 2016 and 2015 , respectively. Total estimated minimum rental commitments were as follows as of December 31, 2017 . 2018 $ 1,509 2019 1,547 2020 1,547 2021 1,493 2022 1,462 Thereafter 5,341 $ 12,899 The Company had commitments to invest in qualified affordable housing projects totaling $6,130 and $5,768 as of December 31, 2017 and 2016 , respectively. Required reserve balances : West Bank is required to maintain an average reserve balance with the Federal Reserve Bank, which is included in cash and due from banks. Required reserve balances were approximately $6,086 and $6,393 as of December 31, 2017 and 2016 , respectively. Financial instruments with off-balance sheet risk : The Company is party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit. These instruments involve, to varying degrees, elements of credit risk in excess of the amount recognized in the consolidated balance sheets. The Company’s exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit and standby letters of credit is represented by the contractual amount of those instruments. The Company uses the same credit policies in making commitments and conditional obligations that it uses for on-balance sheet instruments. Commitments to lend are subject to borrowers’ continuing compliance with existing credit agreements. The Company’s commitments consisted of the following approximate amounts as of December 31, 2017 and 2016 . 2017 2016 Commitments to extend credit $ 617,949 $ 614,681 Standby letters of credit 5,996 5,487 $ 623,945 $ 620,168 Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract and generally expire within one year. Commitments to extend credit of approximately $99,105 at December 31, 2017 , expire beyond one year. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. The amount of collateral obtained is based on management’s credit evaluation of the party. Collateral held varies, but may include accounts receivable, inventory, equipment, and residential and commercial real estate. Standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party and generally expire within one year. Those guarantees are primarily issued to support public and private borrowing arrangements. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. Collateral held varies as specified above and is required in instances the Company deems necessary. In the event the customer does not perform in accordance with the terms of the third-party agreement, West Bank would be required to fund the commitment. The maximum potential amount of future payments West Bank could be required to make is represented by the contractual amount for letters of credit shown in the table above. If the commitment is funded, West Bank would be entitled to seek recovery from the customer. At December 31, 2017 and 2016 , no amounts have been recorded as liabilities for West Bank’s potential obligations under these guarantees. West Bank previously executed MPF Master Commitments (Commitments) with the FHLB of Des Moines to deliver residential mortgage loans and to guarantee the payment of any realized losses that exceed the FHLB’s first loss account for mortgages delivered under the Commitments. West Bank receives credit enhancement fees from the FHLB for providing this guarantee and continuing to assist with managing the credit risk of the MPF Program residential mortgage loans. The term of the most recent Commitment was through January 16, 2015 and was not renewed. At December 31, 2017 , the liability represented by the present value of the credit enhancement fees less any expected losses in the mortgages delivered under the Commitments was approximately $96 . The outstanding balance of mortgage loans sold under the MPF Program was $94,292 and $112,084 at December 31, 2017 and 2016 , respectively. Concentrations of credit risk : Substantially all of the Company’s loans, commitments to extend credit and standby letters of credit have been granted to customers in the Company’s market areas (a 50-mile radius of the greater Des Moines, Iowa, metropolitan area, a 30-mile radius of the Iowa City, Iowa, metropolitan area and a 30-mile radius of the Rochester, Minnesota, metropolitan area). The concentrations of credit by type of loan are set forth in Note 4. The distribution of commitments to extend credit approximates the distribution of loans outstanding. Standby letters of credit were granted primarily to commercial borrowers. Contingencies : Neither the Company nor West Bank is a party, and no property of these entities is subject, to any material pending legal proceedings, other than ordinary routine litigation incidental to West Bank’s business. The Company does not know of any proceeding contemplated by a governmental authority against the Company or West Bank.

Fair Value Measurements (Notes)

Fair Value Measurements (Notes)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Text Block]	Fair Value Measurements Accounting guidance on fair value measurements and disclosures defines fair value and establishes a framework for measuring the fair value of assets and liabilities using a hierarchy system. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants in the market in which the reporting entity transacts business. The Company’s balance sheet contains investment securities available for sale and derivative instruments that are recorded at fair value on a recurring basis. The three-level valuation hierarchy for disclosure of fair value is as follows: Level 1 uses quoted market prices in active markets for identical assets or liabilities. Level 2 uses observable market-based inputs or unobservable inputs that are corroborated by market data. Level 3 uses unobservable inputs that are not corroborated by market data. The Company’s policy is to recognize transfers between Levels at the end of each reporting period, if applicable. There were no transfers between Levels of the fair value hierarchy during 2017 or 2016 . The following is a description of valuation methodologies used for financial assets and liabilities recorded at fair value on a recurring basis. Investment securities available for sale: When available, quoted market prices are used to determine the fair value of investment securities. If quoted market prices are not available, the Company determines fair value based on various sources and may apply matrix pricing with observable prices for similar bonds where a price for the identical bond is not observable. The fair values of these securities are determined by pricing models that consider observable market data such as interest rate volatilities, LIBOR yield curve, credit spreads, prices from market makers and live trading systems. Level 1 securities include certain corporate bonds and would include U.S. Treasuries, if any were held. Level 2 securities include certain corporate bonds, U.S. government and agency securities, collateralized mortgage obligations, mortgage-backed securities, asset-backed securities, state and political subdivision securities and one trust preferred security. At December 31, 2017, the Company classified all of its corporate bonds as Level 2. For this portfolio, the Company has elected to a use matrix pricing model as a practical expedient to individual quoted market prices. The Company currently holds no investment securities classified as Level 3. Generally, management obtains the fair value of investment securities at the end of each reporting period via a third-party pricing service. Management reviewed the valuation process used by the third party and believed that process was valid. On a quarterly basis, management corroborates the fair values of a randomly selected sample of investment securities by obtaining pricing from an independent investment portfolio management firm and compares the two sets of fair values. Any significant variances are reviewed and investigated. For a sample of securities, the fair values are further validated by management, with assistance from an independent investment portfolio management firm, by obtaining details of the inputs used by the pricing service. Those inputs were independently tested, and management concluded the fair values were consistent with GAAP requirements and the investment securities were properly classified in the fair value hierarchy. Derivative instruments: The Company’s derivative instruments consist of interest rate swaps, which are accounted for as cash flow hedges. The Company’s derivative positions are classified within Level 2 of the fair value hierarchy and are valued using models generally accepted in the financial services industry and that use actively quoted or observable market input values from external market data providers and/or nonbinding broker-dealer quotations. The fair value of the derivatives are determined using discounted cash flow models. These models’ key assumptions include the contractual terms of the respective contract along with significant observable inputs, including interest rates, yield curves, nonperformance risk and volatility. The following tables present the balances of assets and liabilities measured at fair value on a recurring basis by level as of December 31, 2017 and 2016 . 2017 Description Total Level 1 Level 2 Level 3 Financial assets: Investment securities available for sale: State and political subdivisions $ 146,313 $ — $ 146,313 $ — Collateralized mortgage obligations 159,932 — 159,932 — Mortgage-backed securities 60,429 — 60,429 — Asset-backed securities 45,195 — 45,195 — Trust preferred security 2,006 — 2,006 — Corporate notes 30,344 — 30,344 — Derivative instrument, interest rate swap 895 — 895 — Financial liabilities: Derivative instrument, interest rate swap $ 86 $ — $ 86 $ — 2016 Description Total Level 1 Level 2 Level 3 Financial assets: Investment securities available for sale: U.S. government agencies and corporations $ 2,593 $ — $ 2,593 $ — State and political subdivisions 64,336 — 64,336 — Collateralized mortgage obligations 101,950 — 101,950 — Mortgage-backed securities 80,158 — 80,158 — Trust preferred security 1,250 — 1,250 — Corporate notes 10,350 10,050 300 — Derivative instrument, interest rate swap 1,068 — 1,068 — Financial liabilities: Derivative instrument, interest rate swap $ 496 $ — $ 496 $ — Certain assets are measured at fair value on a nonrecurring basis. That is, they are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment). As of December 31, 2017 and 2016 , impaired loans with a net book value of $0 and $0 , respectively, for which a fair value adjustment was recorded, were classified as Level 3. Impaired loans are evaluated and valued at the lower of cost or fair value when the loan is identified as impaired. Fair value is measured based on the value of the collateral securing these loans. The types of collateral vary widely and could include accounts receivables, inventory, a variety of equipment and real estate. Evaluations of the underlying assets are completed for each impaired loan with a specific reserve. Collateral evaluations are reviewed and discounted as appropriate based on knowledge of the specific type of collateral. In the case of real estate, an independent appraisal may be obtained. Types of discounts considered included aging of receivables, condition of the collateral, potential market for the collateral and estimated disposal costs. These discounts will vary from loan to loan and may be discounted based on management’s opinions concerning market developments or the client’s business. GAAP requires disclosure of the fair value of financial assets and liabilities, including those that are not measured and reported at fair value on a recurring or nonrecurring basis. The methodologies for estimating the fair value of financial assets and liabilities that are measured at fair value on a recurring or nonrecurring basis are discussed above. The methodologies for other financial assets and liabilities are discussed below. Cash and due from banks : The carrying amount approximates fair value. Federal funds sold : The carrying amount approximates fair value. Investment securities held to maturity : The fair values of these securities, which are all state and political subdivisions, are determined by the same method described previously for investment securities available for sale. FHLB stock : The fair value of this restricted stock is estimated at its carrying value and redemption price of $100 per share. Loans : The fair values of fixed-rate loans are estimated using discounted cash flow analysis based on observable market interest rates currently being offered for loans with similar terms to borrowers with similar credit quality. The carrying values of variable-rate loans approximate their fair values. Deposits : The carrying amounts for demand and savings deposits, which represent the amounts payable on demand, approximate their fair values. The fair values for time deposits are estimated using discounted cash flow analysis, based on observable market interest rates currently being offered on time deposits with similar terms. Accrued interest receivable and payable : The fair values of both accrued interest receivable and payable approximate their carrying amounts. Borrowings : The carrying amounts of federal funds purchased, variable-rate FHLB advances and variable-rate long-term borrowings approximate their fair values. Fair values of subordinated notes, fixed-rate FHLB advances and other long-term borrowings are estimated using a discounted cash flow analysis, based on observable market interest rates currently being offered with similar terms. Commitments to extend credit and standby letters of credit : The approximate fair values of commitments and standby letters of credit are based on the fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and creditworthiness of the counterparties. The following table presents the carrying amounts and approximate fair values of financial assets and liabilities as of December 31, 2017 and 2016 . 2017 2016 Fair Value Hierarchy Level Carrying Amount Approximate Fair Value Carrying Amount Approximate Fair Value Financial assets: Cash and due from banks Level 1 $ 34,952 $ 34,952 $ 40,943 $ 40,943 Federal funds sold Level 1 12,997 12,997 35,893 35,893 Investment securities available for sale See previous table 444,219 444,219 260,637 260,637 Investment securities held to maturity Level 2 45,527 45,890 48,386 47,789 Federal Home Loan Bank stock Level 1 9,174 9,174 10,771 10,771 Loans, net Level 2 1,494,070 1,490,166 1,383,758 1,382,569 Accrued interest receivable Level 1 7,344 7,344 5,321 5,321 Interest rate swap See previous table 895 895 1,068 1,068 Financial liabilities: Deposits Level 2 $ 1,810,813 $ 1,810,924 $ 1,546,605 $ 1,546,307 Federal funds purchased Level 1 545 545 9,690 9,690 Subordinated notes, net Level 2 20,412 15,357 20,398 12,703 Federal Home Loan Bank advances, net Level 2 76,382 76,382 99,886 99,959 Long-term debt, net Level 2 22,917 22,860 5,126 5,054 Accrued interest payable Level 1 736 736 280 280 Interest rate swap See previous table 86 86 496 496 Off-balance-sheet financial instruments: Commitments to extend credit Level 3 — — — — Standby letters of credit Level 3 — — — —

West Bancorporation, Inc. (Pare

West Bancorporation, Inc. (Parent Company Only) Condensed Financial Statements (Notes)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Financial Information of Parent Company Only Disclosure [Text Block]	West Bancorporation, Inc. (Parent Company Only) Condensed Financial Statements Balance Sheets December 31, 2017 and 2016 2017 2016 ASSETS Cash $ 3,226 $ 3,945 Investment in West Bank 216,693 168,302 Investment in West Bancorporation Capital Trust I 619 619 Premises, net — 18,194 Other assets 1,034 1,256 Total assets $ 221,572 $ 192,316 LIABILITIES AND STOCKHOLDERS’ EQUITY LIABILITIES Accrued expenses and other liabilities $ 562 $ 1,416 Subordinated notes, net 20,412 20,398 Long-term debt, net 22,500 5,126 Total liabilities 43,474 26,940 STOCKHOLDERS’ EQUITY Preferred stock — — Common stock 3,000 3,000 Additional paid-in capital 23,463 21,462 Retained earnings 153,527 141,956 Accumulated other comprehensive loss (1,892 ) (1,042 ) Total stockholders’ equity 178,098 165,376 Total liabilities and stockholders’ equity $ 221,572 $ 192,316 Statements of Income Years Ended December 31, 2017, 2016 and 2015 2017 2016 2015 Operating income: Equity in net income of West Bank $ 23,933 $ 23,544 $ 22,546 Equity in net income of West Bancorporation Capital Trust I 27 23 21 Intercompany rental income 333 503 207 Other rental income 21 50 43 Total operating income 24,314 24,120 22,817 Operating expenses: Interest on subordinated notes 901 728 705 Interest on long-term debt 517 145 232 Occupancy 187 280 170 Other expenses 602 443 496 Total operating expenses 2,207 1,596 1,603 Income before income taxes 22,107 22,524 21,214 Income tax benefits (963 ) (492 ) (528 ) Net income $ 23,070 $ 23,016 $ 21,742 Statements of Cash Flows Years Ended December 31, 2017, 2016 and 2015 2017 2016 2015 Cash Flows from Operating Activities: Net income $ 23,070 $ 23,016 $ 21,742 Adjustments to reconcile net income to net cash provided by operating activities: Equity in net income of West Bank (23,933 ) (23,544 ) (22,546 ) Equity in net income of West Bancorporation Capital Trust I (27 ) (23 ) (21 ) Dividends received from West Bank 16,800 14,400 13,900 Dividends received from West Bancorporation Capital Trust I 27 23 21 Amortization 17 20 23 Depreciation 178 244 139 Deferred income tax (benefits) (240 ) 97 99 Change in assets and liabilities: (Increase) decrease in other assets 50 (79 ) 1,436 Increase (decrease) in accrued expenses and other liabilities (549 ) 641 (31 ) Net cash provided by operating activities 15,393 14,795 14,762 Cash Flows from Investing Activities: Proceeds from sales of premises 18,032 — — Purchases of premises (16 ) (10,539 ) (1,386 ) Proceeds from sales of other real estate owned — — 2,227 Proceeds from settlement of other assets — — 3,593 Capital contribution to West Bank (40,000 ) — — Net cash provided by (used in) investing activities (21,984 ) (10,539 ) 4,434 Cash Flows from Financing Activities: Proceeds from long-term debt 22,000 — — Principal payments on long-term debt (4,629 ) (3,286 ) (4,261 ) Common stock cash dividends (11,499 ) (10,800 ) (9,952 ) Net cash provided by (used in) financing activities 5,872 (14,086 ) (14,213 ) Net increase (decrease) in cash (719 ) (9,830 ) 4,983 Cash: Beginning 3,945 13,775 8,792 Ending $ 3,226 $ 3,945 $ 13,775

Selected Quarterly Financial Da

Selected Quarterly Financial Data (unaudited) (Notes)	12 Months Ended
	Dec. 31, 2017
Selected Quarterly Financial Information [Abstract]
Quarterly Financial Information [Text Block]	Selected Quarterly Financial Data (unaudited) 2017 Three months ended March 31 June 30 September 30 December 31 Interest income $ 16,791 $ 18,166 $ 18,560 $ 19,517 Interest expense 2,402 3,073 3,529 3,973 Net interest income 14,389 15,093 15,031 15,544 Provision for loan losses — — — — Net interest income after provision for loan losses 14,389 15,093 15,031 15,544 Noninterest income 2,160 2,316 2,264 1,908 Noninterest expense 8,043 8,172 8,020 8,032 Income before income taxes 8,506 9,237 9,275 9,420 Income taxes 2,400 2,872 2,870 5,226 Net income $ 6,106 $ 6,365 $ 6,405 $ 4,194 Basic earnings per common share $ 0.38 $ 0.39 $ 0.40 $ 0.26 Diluted earnings per common share $ 0.37 $ 0.39 $ 0.39 $ 0.26 2016 Three months ended March 31 June 30 September 30 December 31 Interest income $ 15,524 $ 16,209 $ 16,696 $ 16,565 Interest expense 1,825 1,936 1,975 2,140 Net interest income 13,699 14,273 14,721 14,425 Provision for loan losses 200 500 200 100 Net interest income after provision for loan losses 13,499 13,773 14,521 14,325 Noninterest income 2,230 1,903 1,919 1,930 Noninterest expense 7,799 7,819 7,993 7,537 Income before income taxes 7,930 7,857 8,447 8,718 Income taxes 2,234 2,381 2,634 2,687 Net income $ 5,696 $ 5,476 $ 5,813 $ 6,031 Basic earnings per common share $ 0.35 $ 0.34 $ 0.36 $ 0.37 Diluted earnings per common share $ 0.35 $ 0.34 $ 0.36 $ 0.37

Organization and Nature of Bu28

Organization and Nature of Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Use of Estimates, Policy [Policy Text Block]	Accounting estimates and assumptions : The consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (GAAP) established by the Financial Accounting Standards Board (FASB). References to GAAP issued by the FASB in these footnotes are to the FASB Accounting Standards Codification TM , sometimes referred to as the Codification or ASC. In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses for the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near term are the fair value of financial instruments and the allowance for loan losses.
Consolidation, Policy [Policy Text Block]	Consolidation policy : The consolidated financial statements include the accounts of the Company, West Bank and West Bank’s wholly-owned subsidiary WB Funding Corporation (which owned an interest in a limited liability company that was sold in the fourth quarter of 2015). All significant intercompany transactions and balances have been eliminated in consolidation. In addition, the Company owns an unconsolidated subsidiary, West Bancorporation Capital Trust I (the Trust), which was formed for the purpose of issuing trust preferred securities. In accordance with GAAP, the results of the Trust are recorded on the books of the Company using the equity method of accounting and are not consolidated.
Reclassification, Policy [Policy Text Block]	Reclassification: Certain amounts in prior year financial statements have been reclassified, with no effect on net income, comprehensive income or stockholder's equity, to conform with current period presentation.
Segment Reporting, Policy [Policy Text Block]	Segment information: An operating segment is generally defined as a component of a business for which discrete financial information is available and whose operating results are regularly reviewed by the chief operating decision-maker. The Company has determined that its business is comprised of one operating segment, which is banking. The banking segment generates revenue through interest and fees on loans, interest on investment securities, service charges on deposit accounts, fees for trust services and other miscellaneous banking related activities. This segment includes the Company, West Bank, and related elimination entries between the two, as the Company’s operation is similar to that of West Bank.
Comprehensive Income, Policy [Policy Text Block]	Comprehensive income : Comprehensive income consists of net income and other comprehensive income (OCI). OCI consists of the net change in unrealized gains and losses on the Company’s investment securities available for sale, including the noncredit-related portion of unrealized gains (losses) of OTTI securities, if any, and the effective portion of the change in fair value of derivative instruments. OCI also includes the amortization of derivative termination costs and the amortization of unrealized gains on investment securities transferred from available for sale to held to maturity.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and cash equivalents and cash flows : For statement of cash flow purposes, the Company considers cash, due from banks and federal funds sold to be cash and cash equivalents. Cash inflows and outflows from loans and deposits are reported on a net basis.
Investment Securities, Policy [Policy Text Block]	Investment securities : Investment securities that management has the intent and ability to hold to maturity are classified as held to maturity and reported at amortized cost. Investment securities that may be sold for general liquidity needs, in response to market interest rate fluctuations, implementation of asset-liability management strategies, funding loan demand, changes in securities prepayment risk or other similar factors are classified as available for sale and reported at fair value, with unrealized gains and losses reported as a separate component of accumulated other comprehensive income (AOCI), net of deferred income taxes. Realized gains and losses on sales of investment securities are computed on a specific identification basis based on amortized cost. The amortized cost of debt securities classified as held to maturity or available for sale is adjusted for accretion of discounts to maturity and amortization of premiums over the estimated average life of each security or, in the case of callable securities, through the first call date, using the effective yield method. Such amortization and accretion is included in interest income. Interest income on securities is recognized using the interest method according to the terms of the investment security. The Company evaluates each of its investment securities whose value has declined below amortized cost to determine whether the decline in fair value is OTTI. When determining whether an investment security is OTTI, management assesses the severity and duration of the decline in fair value, the length of time expected for recovery, the financial condition of the issuer and other qualitative factors, as well as whether: (a) it has the intent to sell the security, and (b) it is more likely than not that it will be required to sell the security prior to its anticipated recovery. In instances when a determination is made that an OTTI exists but management does not intend to sell the security and it is not more likely than not that it will be required to sell the security prior to its anticipated repayment or maturity, the OTTI is separated into: (a) the amount of the total OTTI related to a decrease in cash flows expected to be collected from the security (the credit loss); and (b) the amount of the total OTTI related to all other factors. The amount of the total OTTI related to the credit loss is recognized as a charge to earnings. The amount of the total OTTI related to all other factors is recognized in OCI. If the Company intends to sell or it is more likely than not that it will be required to sell a security with OTTI before recovery of its amortized cost basis, the OTTI is recognized in earnings equal to the entire difference between the investment’s amortized cost basis and its fair value at the balance sheet date.
Federal Home Loan Bank Stock [Policy Text Block]	Federal Home Loan Bank stock : West Bank, as a member of the Federal Home Loan Bank (FHLB) system, is required to maintain an investment in capital stock of the FHLB in an amount equal to 0.12 percent of total assets plus 4.00 percent of outstanding advances from the FHLB and the outstanding principal balance of loans previously issued through the Mortgage Partnership Finance Program (MPF). No ready market exists for the FHLB stock, and it has no quoted market value. The Company evaluates this asset for impairment on a quarterly basis and determined there was no impairment as of December 31, 2017 . All shares of FHLB stock are issued and redeemed at par value.
Loans and Leases Receivable, Origination Fees, Discounts or Premiums, and Direct Costs to Acquire Loans Policy [Policy Text Block]	Loans : Loans are stated at the principal amounts outstanding, net of unamortized loan fees and costs, with interest income recognized on the interest method based upon the terms of the loan. Loan origination fees, net of certain direct origination costs, are deferred and recognized as an adjustment of the related loan yield using the interest method. Loans are reported by the portfolio segments identified and are analyzed by management on this basis. All loan policies identified below apply to all segments of the loan portfolio.
Loans and Leases Receivable, Nonaccrual Loan and Lease Status, Policy [Policy Text Block]	Delinquencies are determined based on the payment terms of the individual loan agreements. The accrual of interest on past due and other impaired loans is generally discontinued at 90 days past due or when, in the opinion of management, the borrower may be unable to make all payments pursuant to contractual terms. Unless considered collectible, all interest accrued but not collected for loans that are placed on nonaccrual or charged off is reversed against interest income, if accrued in the current year, or charged to the allowance for loan losses, if accrued in the prior year. Generally, all payments received while a loan is on nonaccrual status are applied to the principal balance of the loan. Loans are returned to accrual status when all principal and interest amounts contractually due are brought current and future payments are reasonably assured.
Loans and Leases Receivable, Troubled Debt Restructuring Policy [Policy Text Block]	A loan is classified as troubled debt restructured (TDR) when the Company separately concludes that a borrower is experiencing financial difficulties and a concession is granted that would not otherwise be considered. Concessions may include a restructuring of the loan terms to alleviate the burden of the borrower’s cash requirements, such as an extension of the payment terms beyond the original maturity date or a change in the interest rate charged. TDR loans with extended payment terms are accounted for as impaired until performance is established. A change to the interest rate would change the classification of a loan to a TDR loan if the restructured loan yields a rate that is below a market rate for that of a new loan with comparable risk. TDR loans with below market rates are considered impaired until fully collected. TDR loans may also be reported as nonaccrual or 90 days past due if they are not performing per the restructured terms.
Impaired Financing Receivable, Policy [Policy Text Block]	Based upon its ongoing assessment of credit quality within the loan portfolio, the Company maintains a Watch List, which includes loans classified as Doubtful, Substandard and Watch according to the Company’s classification criteria. These loans involve the anticipated potential for payment defaults or collateral inadequacies. A loan on the Watch List is considered impaired when management believes it is probable the Company will be unable to collect all contractual principal and interest payments due in accordance with the terms of the loan agreement. Impaired loans are measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate or, as a practical expedient, at the loan’s observable market price or the fair value of the collateral if the loan is collateral dependent. The amount of impairment, if any, and any subsequent changes are included in the allowance for loan losses.
Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block]	Allowance for loan losses : The allowance for loan losses is established through a provision for loan losses charged to expense. The allowance is an amount that management believes will be adequate to absorb probable losses on existing loans based on an evaluation of the collectability of loans and prior loss experience. This evaluation also takes into consideration such factors as changes in the nature and volume of the loan portfolio, overall portfolio quality, the review of specific problem loans, and current economic conditions that may affect the borrowers’ ability to pay. Loans are charged off against the allowance for loan losses when management believes that collectability of the principal is unlikely. While management uses the best information available to make its evaluations, future adjustments to the allowance may be necessary if there are significant changes in economic conditions or the other factors relied upon. The allowance for loan losses consists of specific and general components. The specific component relates to loans that meet the definition of impaired. The general component covers the remaining loans and is based on historical loss experience adjusted for qualitative factors such as delinquency trends, loan growth, economic elements and local market conditions. These same policies are applied to all segments of loans. In addition, regulatory agencies, as integral parts of their examination processes, periodically review the Company’s allowance for loan losses, and may require the Company to make additions to the allowance based on their judgment about information available to them at the time of their examinations.
Property, Plant and Equipment, Policy [Policy Text Block]	Premises and equipment : Premises and equipment are stated at cost less accumulated depreciation. The straight-line method of depreciation and amortization is used for calculating expense. The estimated useful lives of premises and equipment range up to 40 years for buildings, up to 10 years for furniture and equipment, and the shorter of the estimated useful life or lease term for leasehold improvements.
Loans and Leases Receivable, Real Estate Acquired Through Foreclosure, Policy [Policy Text Block]	Other real estate owned : Real estate properties acquired through or in lieu of foreclosure are initially recorded at fair value less estimated selling cost at the date of foreclosure, establishing a new cost basis. Fair value is determined by management by obtaining appraisals or other market value information at least annually. Any write-downs in value at the date of acquisition are charged to the allowance for loan losses. After foreclosure, valuations are periodically performed by management by obtaining updated appraisals or other market value information. Any subsequent write-downs are recorded as a charge to operations, if necessary, to reduce the carrying value of a property to the updated fair value less estimated selling cost. Net costs related to the holding of properties are included in noninterest expense. As of December 31, 2017 and 2016 , the Company had no other real estate owned.
Trust Assets Policy [Policy Text Block]	Trust assets : Assets held by West Bank in fiduciary or agency capacities, other than trust cash on deposit at West Bank, are not included in the consolidated balance sheets of the Company, as such assets are not assets of West Bank.
Bank-Owned Life Insurance [Policy Text Block]	Bank-owned life insurance : The carrying amount of bank-owned life insurance consists of the initial premium paid, plus increases in cash value, less the carrying amount associated with any death benefit received. Death benefits paid in excess of the applicable carrying amount are recognized as income. Increases in cash value and the portion of death benefits recognized as income are exempt from income taxes.
Derivatives, Policy [Policy Text Block]	Derivatives: The Company uses derivative financial instruments (which consist of interest rate swaps) to assist in its interest rate risk management. All derivatives are measured and reported at fair value on the Company’s consolidated balance sheet as other assets or other liabilities. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative and the resulting designation. As of December 31, 2017 , the Company had cash flow hedging relationships, which were derivatives to hedge the exposure to variability in expected future cash flows. To qualify for hedge accounting, the Company must comply with the detailed rules and documentation requirements at the inception of the hedge, and hedge effectiveness is assessed at inception and on a quarterly basis throughout the life of each hedging relationship. Hedge ineffectiveness, if any, is measured periodically throughout the life of the hedging relationship. The Company does not use derivatives for trading or speculative purposes. For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of the derivative is initially reported in OCI, net of deferred taxes, and subsequently reclassified to interest income or expense when the hedged transaction affects earnings, while the ineffective portion of changes in the fair value of the derivative, if any, is recognized immediately in other noninterest income. The Company assesses the effectiveness of the hedging relationship by comparing the cumulative changes in cash flows of the derivative hedging instrument with the cumulative changes in cash flows of the designated hedged item or transaction.
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	Stock-based compensation: The Company’s current and previous equity incentive plans were approved by the stockholders as a means to attract, retain and reward selected participants. The plans are administered by the Compensation Committee of the Board of Directors. Compensation expense for stock-based awards is recognized on a straight-line basis over the vesting period using the fair value of the award at the time of the grant. The restricted stock unit (RSU) participants do not have dividend rights prior to vesting, so the fair value of nonvested RSUs is equal to the fair market value of the underlying common stock at the grant date, reduced by the present value of the dividends expected to be paid on the underlying shares during the vesting period. Prior to January 1, 2017, the Company assumed no projected forfeitures on its stock-based compensation, since all RSUs were expected to vest and no forfeitures had occurred as of December 31, 2016. Upon adoption of ASU No. 2016-09, Compensation - Stock Compensation (Topic 718) on January 1, 2017, the Company made the accounting policy election to account for forfeitures as they occur.
Deferred compensation [Policy Text Block]	Deferred compensation: The West Bancorporation, Inc. Deferred Compensation Plan (the Deferred Compensation Plan) was adopted effective January 1, 2013, to provide certain individuals with additional deferral opportunities in planning for retirement. Eligible participants, including directors and key officers of the Company, may choose to voluntarily defer receipt of a portion of their respective cash compensation. The Deferred Compensation Plan is an unfunded, nonqualified deferred compensation plan intended to conform to the requirements of Section 409A of the Internal Revenue Code. As of December 31, 2017 , no individuals had chosen to participate in the Plan.
Transfers and Servicing of Financial Assets, Policy [Policy Text Block]	Transfer of financial assets : Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when the assets have been isolated from the Company, the transferee obtains the right, free of conditions that constrain it from taking advantage of that right, to pledge or exchange the transferred assets, and the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity.
Income Tax, Policy [Policy Text Block]	Income taxes : The Company files a consolidated federal income tax return. Income tax expense is generally allocated as if the Company and its subsidiary file separate income tax returns. Deferred taxes are provided on an asset and liability method whereby deferred tax assets are recognized for deductible temporary differences, capital losses and net operating losses, and deferred tax liabilities are recognized for taxable temporary differences. Temporary differences are the differences between the reported amounts of assets and liabilities and their tax basis. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion or all of the deferred tax assets will not be realized. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. When tax returns are filed, it is highly certain that some tax positions taken will be sustained upon examination by the taxing authorities, while others are subject to uncertainty about the merits of the positions taken or the amount of the position that would be ultimately sustained. The benefit of a tax position is recognized in the consolidated financial statements in the period during which, based on all available evidence, management believes it is more likely than not that the position will be sustained upon examination, including the resolution of appeals or litigation processes, if any. The evaluation of a tax position taken is considered by itself and is not offset or aggregated with other positions. Tax positions that meet the more likely than not recognition threshold are measured as the largest amount of tax benefit that is more than 50 percent likely of being realized upon settlement with the applicable taxing authority. Management does not believe the Company has any material uncertain tax positions to disclose. Interest and penalties, if any, related to income taxes are recorded as other noninterest expense in the consolidated income statements in the year assessed.
Earnings Per Share, Policy [Policy Text Block]	Earnings per common share : Basic earnings per common share are computed by dividing net income by the weighted average number of common shares outstanding for the period. Diluted earnings per common share reflect the potential dilution that could occur if the Company’s outstanding RSUs were vested. The dilutive effect is computed using the treasury stock method, which assumes all stock-based awards were exercised and the hypothetical proceeds from exercise were used by the Company to purchase common stock at the average market price during the period.
New Accounting Pronouncements, Policy [Policy Text Block]	Current accounting developments : In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). The guidance in this update supersedes the revenue recognition requirements in ASC Topic 605, Revenue Recognition, and most industry-specific guidance throughout the industry topics of the Codification. For public companies, this update will be effective for interim and annual periods beginning after December 15, 2017. The Company adopted the guidance effective January 1, 2018, using the modified retrospective method. The Company's revenue is primarily composed of interest income on financial instruments, including investment securities and loans, which are excluded from the scope of this update. Also excluded from the scope of the update is revenue from bank-owned life insurance, loan fees and letter of credit fees. Service charges on deposit accounts are within the scope of the guidance; however, current revenue recognition practices will not change under the guidance, as deposit agreements are considered day-to-day contracts. Other noninterest income sources of revenue are considered immaterial. Implementation of the guidance will not change current business practices or internal controls for financial reporting. Implementation of the guidance will not have a material impact on the Company's consolidated financial statements. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. The update enhances the reporting model for financial instruments to provide users of financial statements with more decision-useful information by updating certain aspects of recognition, measurement, presentation and disclosure of financial instruments. Among other changes, the update requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes, and clarifies that entities should evaluate the need for a valuation allowance on a deferred tax asset related to available for sale securities in combination with the entities' other deferred tax assets. For public companies, this update will be effective for interim and annual periods beginning after December 15, 2017, and is to be applied on a modified retrospective basis. Upon the effective date, the fair value of the Company's loan portfolio will be presented using an exit price method. The Company has concluded that the remaining requirements of this update are not expected to have a material impact on the Company's consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The guidance in the update supersedes the requirements in ASC Topic 840, Leases. The guidance is intended to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet for leases with terms of more than 12 months. For public companies, this update will be effective for interim and annual periods beginning after December 15, 2018, and is to be applied on a modified retrospective basis. The Company currently leases its main location and space for six other branch offices and operational departments under operating leases that will result in recognition of lease assets and lease liabilities on the consolidated balance sheets under the update. The amount of assets and liabilities added to the balance sheet are not expected to have a material impact on the Company's consolidated financial statements per preliminary estimates. In March 2016, the FASB issued ASU No. 2016-09, Compensation—Stock Compensation (Topic 718). The guidance in this update simplifies several aspects of accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The guidance also allows an entity to make an entity-wide accounting policy election to either estimate expected forfeitures or account for forfeitures as they occur. For public companies, the update was effective for annual periods beginning after December 15, 2016. Portions of the amended guidance were to be applied using a modified retrospective transition method, and others required prospective application. Upon adoption of this update on January 1, 2017, the Company made the accounting policy election to account for forfeitures as they occur. This resulted in no effect on the Company's consolidated financial statements, as prior stock-based compensation expense assumed no expected forfeitures. Upon adoption, the Company changed the calculation of the assumed proceeds of the treasury stock method on a prospective basis to eliminate deferred taxes from the calculation. The net impact on the income statement is dependent upon the change in the Company's stock price from grant date to vesting date and cannot be predicted by management with any certainty. The requirement to report the excess tax benefit or shortfall related to settlements of share-based payment awards in earnings as an increase or decrease to tax expense, rather than within additional paid-in-capital, has been applied to settlements occurring on or after January 1, 2017, and the impact of applying that guidance reduced reported income tax expense by $285 for the year ended December 31, 2017. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326). The amendments in this update require a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial assets to present the net carrying value at the amount expected to be collected on the financial assets. The income statement reflects the measurement of credit losses for newly recognized financial assets, as well as the expected increases or decreases of expected credit losses that have taken place during the period. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectibility of the reported amount of financial assets. An entity must use judgment in determining the relevant information and estimation methods that are appropriate in its circumstances. The allowance for credit losses for purchased financial assets with a more-than-insignificant amount of credit deterioration since origination that are measured at amortized cost basis is determined in a similar manner to other financial assets measured at amortized cost basis; however, the initial allowance for credit losses is added to the purchase price rather than being reported as a credit loss expense. Only subsequent changes in the allowance for credit losses are recorded as a credit loss expense for these assets. Off-balance-sheet arrangements such as commitments to extend credit, guarantees, and standby letters of credit that are not considered derivatives under ASC 815 and are not unconditionally cancellable are also within the scope of this update. Credit losses relating to available for sale debt securities should be recorded through an allowance for credit losses. For public companies, the update is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. All entities may adopt the amendments in this update earlier as of fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. An entity will apply the amendments in this update on a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The Company does not plan to early adopt this standard, but is currently planning for the implementation. It is too early to assess the impact that this guidance will have on the Company's consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The amendments in this update provide guidance for eight specific cash flow classification issues for which current guidance is unclear or does not exist, thereby reducing diversity in practice. For public companies, the update is effective for annual periods beginning after December 15, 2017, with early adoption permitted. The Company's early adoption of the update as of January 1, 2017, did not have a material impact on the Company's consolidated financial statements. In March 2017, the FASB issued ASU No. 2017-08, Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities . The amendments in this update shorten the amortization period for certain purchased callable debt securities held at a premium. The amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. For public companies, the update is effective for annual periods beginning after December 15, 2018, and is to be applied on a modified retrospective basis with a cumulative-effect adjustment directly to retained earnings as of the beginning of the adoption period. Early adoption is permitted, including adoption in an interim period. The Company adopted the amendments in the fourth quarter of 2017, and it had no impact on the Company's consolidated financial statements. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities . The amendments in this update better align an entity's risk management activities and financial reporting for hedging relationships through changes to both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results. For public companies, the update is effective for annual periods beginning after December 15, 2018, with early adoption permitted, including in an interim period. The amendments' presentation and disclosure guidance is required on a prospective basis. The Company is currently assessing the impact of this guidance, but does not expect the guidance to have a material impact on the Company's consolidated financial statements. In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendment in this update allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the December 22, 2017, enactment of the reduced federal corporate income tax rate, which is effective in 2018. For public companies, the update is effective for annual periods beginning after December 15, 2018, with early adoption permitted. The amendment can be adopted at the beginning of the period or on a retrospective basis. The Company plans to adopt the amendment in the first quarter of 2018 using the beginning of the period option. The reclassified amount will be $369.
Off-Balance-Sheet Credit Exposure, Policy [Policy Text Block]	Financial instruments with off-balance sheet risk : The Company is party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit. These instruments involve, to varying degrees, elements of credit risk in excess of the amount recognized in the consolidated balance sheets. The Company’s exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit and standby letters of credit is represented by the contractual amount of those instruments. The Company uses the same credit policies in making commitments and conditional obligations that it uses for on-balance sheet instruments. Commitments to lend are subject to borrowers’ continuing compliance with existing credit agreements.
Fair Value Measurement, Policy [Policy Text Block]	Accounting guidance on fair value measurements and disclosures defines fair value and establishes a framework for measuring the fair value of assets and liabilities using a hierarchy system. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants in the market in which the reporting entity transacts business. The Company’s balance sheet contains investment securities available for sale and derivative instruments that are recorded at fair value on a recurring basis. The three-level valuation hierarchy for disclosure of fair value is as follows: Level 1 uses quoted market prices in active markets for identical assets or liabilities. Level 2 uses observable market-based inputs or unobservable inputs that are corroborated by market data. Level 3 uses unobservable inputs that are not corroborated by market data. The Company’s policy is to recognize transfers between Levels at the end of each reporting period, if applicable. There were no transfers between Levels of the fair value hierarchy during 2017 or 2016 . The following is a description of valuation methodologies used for financial assets and liabilities recorded at fair value on a recurring basis. Investment securities available for sale: When available, quoted market prices are used to determine the fair value of investment securities. If quoted market prices are not available, the Company determines fair value based on various sources and may apply matrix pricing with observable prices for similar bonds where a price for the identical bond is not observable. The fair values of these securities are determined by pricing models that consider observable market data such as interest rate volatilities, LIBOR yield curve, credit spreads, prices from market makers and live trading systems. Level 1 securities include certain corporate bonds and would include U.S. Treasuries, if any were held. Level 2 securities include certain corporate bonds, U.S. government and agency securities, collateralized mortgage obligations, mortgage-backed securities, asset-backed securities, state and political subdivision securities and one trust preferred security. At December 31, 2017, the Company classified all of its corporate bonds as Level 2. For this portfolio, the Company has elected to a use matrix pricing model as a practical expedient to individual quoted market prices. The Company currently holds no investment securities classified as Level 3. Generally, management obtains the fair value of investment securities at the end of each reporting period via a third-party pricing service. Management reviewed the valuation process used by the third party and believed that process was valid. On a quarterly basis, management corroborates the fair values of a randomly selected sample of investment securities by obtaining pricing from an independent investment portfolio management firm and compares the two sets of fair values. Any significant variances are reviewed and investigated. For a sample of securities, the fair values are further validated by management, with assistance from an independent investment portfolio management firm, by obtaining details of the inputs used by the pricing service. Those inputs were independently tested, and management concluded the fair values were consistent with GAAP requirements and the investment securities were properly classified in the fair value hierarchy. Derivative instruments: The Company’s derivative instruments consist of interest rate swaps, which are accounted for as cash flow hedges. The Company’s derivative positions are classified within Level 2 of the fair value hierarchy and are valued using models generally accepted in the financial services industry and that use actively quoted or observable market input values from external market data providers and/or nonbinding broker-dealer quotations. The fair value of the derivatives are determined using discounted cash flow models. These models’ key assumptions include the contractual terms of the respective contract along with significant observable inputs, including interest rates, yield curves, nonperformance risk and volatility.
Fair Value Transfer, Policy [Policy Text Block]	The Company’s policy is to recognize transfers between Levels at the end of each reporting period, if applicable.
Fair Value of Financial Instruments, Policy [Policy Text Block]	GAAP requires disclosure of the fair value of financial assets and liabilities, including those that are not measured and reported at fair value on a recurring or nonrecurring basis. The methodologies for estimating the fair value of financial assets and liabilities that are measured at fair value on a recurring or nonrecurring basis are discussed above. The methodologies for other financial assets and liabilities are discussed below. Cash and due from banks : The carrying amount approximates fair value. Federal funds sold : The carrying amount approximates fair value. Investment securities held to maturity : The fair values of these securities, which are all state and political subdivisions, are determined by the same method described previously for investment securities available for sale. FHLB stock : The fair value of this restricted stock is estimated at its carrying value and redemption price of $100 per share. Loans : The fair values of fixed-rate loans are estimated using discounted cash flow analysis based on observable market interest rates currently being offered for loans with similar terms to borrowers with similar credit quality. The carrying values of variable-rate loans approximate their fair values. Deposits : The carrying amounts for demand and savings deposits, which represent the amounts payable on demand, approximate their fair values. The fair values for time deposits are estimated using discounted cash flow analysis, based on observable market interest rates currently being offered on time deposits with similar terms. Accrued interest receivable and payable : The fair values of both accrued interest receivable and payable approximate their carrying amounts. Borrowings : The carrying amounts of federal funds purchased, variable-rate FHLB advances and variable-rate long-term borrowings approximate their fair values. Fair values of subordinated notes, fixed-rate FHLB advances and other long-term borrowings are estimated using a discounted cash flow analysis, based on observable market interest rates currently being offered with similar terms. Commitments to extend credit and standby letters of credit : The approximate fair values of commitments and standby letters of credit are based on the fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and creditworthiness of the counterparties.

Earnings per Common Share (Tabl

Earnings per Common Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The calculation of earnings per common share and diluted earnings per common share is presented below for the years ended December 31, 2017 , 2016 and 2015 . (in thousands, except per share data) 2017 2016 2015 Net income $ 23,070 $ 23,016 $ 21,742 Weighted average common shares outstanding 16,194 16,117 16,050 Weighted average effect of restricted stock units outstanding 141 54 46 Diluted weighted average common shares outstanding 16,335 16,171 16,096 Basic earnings per common share $ 1.42 $ 1.43 $ 1.35 Diluted earnings per common share $ 1.41 $ 1.42 $ 1.35 Number of anti-dilutive common stock equivalents excluded from diluted earnings per share computation — 102 140

Investment securities (Tables)

Investment securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Unrealized Gain (Loss) on Investments [Table Text Block]	The following tables show the amortized cost, gross unrealized gains and losses and fair value of investment securities, by investment security type as of December 31, 2017 and 2016 . 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Securities available for sale: State and political subdivisions $ 146,331 $ 928 $ (946 ) $ 146,313 Collateralized mortgage obligations (1) 162,631 28 (2,727 ) 159,932 Mortgage-backed securities (1) 60,956 20 (547 ) 60,429 Asset-backed securities (2) 45,539 8 (352 ) 45,195 Trust preferred security 2,134 — (128 ) 2,006 Corporate notes 30,278 331 (265 ) 30,344 $ 447,869 $ 1,315 $ (4,965 ) $ 444,219 Securities held to maturity: State and political subdivisions $ 45,527 $ 460 $ (97 ) $ 45,890 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Securities available for sale: U.S. government agencies and corporations $ 2,524 $ 69 $ — $ 2,593 State and political subdivisions 64,551 376 (591 ) 64,336 Collateralized mortgage obligations (1) 103,038 255 (1,343 ) 101,950 Mortgage-backed securities (1) 80,614 341 (797 ) 80,158 Trust preferred security 1,784 — (534 ) 1,250 Corporate notes 10,326 25 (1 ) 10,350 $ 262,837 $ 1,066 $ (3,266 ) $ 260,637 Securities held to maturity: State and political subdivisions $ 48,386 $ 70 $ (667 ) $ 47,789 (1) All collateralized mortgage obligations and mortgage-backed securities consist of residential mortgage pass-through securities guaranteed by FHLMC or FNMA, real estate mortgage investment conduits guaranteed by FNMA, FHLMC or GNMA, and commercial mortgage pass-through securities guaranteed by the SBA. (2) Pass-through asset-backed securities guaranteed by the SBA, representing participating interests in pools of long-term debentures issued by state and local development companies certified by the SBA.
Investments Classified by Contractual Maturity Date [Table Text Block]	The amortized cost and fair value of investment securities available for sale as of December 31, 2017 , by contractual maturity, are shown below. Certain securities have call features that allow the issuer to call the securities prior to maturity. Expected maturities may differ from contractual maturities for collateralized mortgage obligations, mortgage-backed securities and asset-backed securities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Therefore, collateralized mortgage obligations, mortgage-backed securities and asset-backed securities are not included in the maturity categories within the following maturity summary. 2017 Amortized Cost Fair Value Due in one year or less $ 110 $ 110 Due after one year through five years 2,355 2,358 Due after five years through ten years 41,525 41,710 Due after ten years 134,753 134,485 178,743 178,663 Collateralized mortgage obligations, mortgage-backed and asset-backed securities 269,126 265,556 $ 447,869 $ 444,219 The amortized cost and fair value of investment securities held to maturity as of December 31, 2017 , by contractual maturity, are shown below. Certain securities have call features that allow the issuer to call the securities prior to maturity. 2017 Amortized Cost Fair Value Due after one year through five years $ 1,594 $ 1,588 Due after five years through ten years 26,621 26,798 Due after ten years 17,312 17,504 $ 45,527 $ 45,890
Schedule of Realized Gain (Loss) [Table Text Block]	The details of the sales of investment securities for the years ended December 31, 2017 , 2016 and 2015 are summarized in the following table. 2017 2016 2015 Proceeds from sales $ 108,584 $ 3,054 $ 16,946 Gross gains on sales 752 66 54 Gross losses on sales 426 — 7
Schedule of Unrealized Loss on Investments [Table Text Block]	The following tables show the fair value and gross unrealized losses, aggregated by investment type and length of time that individual securities have been in a continuous loss position, as of December 31, 2017 and 2016 . 2017 Less than 12 months 12 months or longer Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Securities available for sale: State and political subdivisions $ 86,750 $ (946 ) $ — $ — $ 86,750 $ (946 ) Collateralized mortgage obligations 107,526 (1,583 ) 46,396 (1,144 ) 153,922 (2,727 ) Mortgage-backed securities 53,974 (547 ) — — 53,974 (547 ) Asset-backed securities 38,652 (352 ) — — 38,652 (352 ) Trust preferred security — — 2,006 (128 ) 2,006 (128 ) Corporate notes 14,735 (265 ) — — 14,735 (265 ) $ 301,637 $ (3,693 ) $ 48,402 $ (1,272 ) $ 350,039 $ (4,965 ) Securities held to maturity: State and political subdivisions $ 12,611 $ (70 ) $ 1,740 $ (27 ) $ 14,351 $ (97 ) 2016 Less than 12 months 12 months or longer Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Securities available for sale: State and political subdivisions $ 34,903 $ (591 ) $ — $ — $ 34,903 $ (591 ) Collateralized mortgage obligations 75,771 (1,255 ) 2,538 (88 ) 78,309 (1,343 ) Mortgage-backed securities 60,221 (797 ) — — 60,221 (797 ) Trust preferred security — — 1,250 (534 ) 1,250 (534 ) Corporate notes 1,499 (1 ) — — 1,499 (1 ) $ 172,394 $ (2,644 ) $ 3,788 $ (622 ) $ 176,182 $ (3,266 ) Securities held to maturity: State and political subdivisions $ 32,976 $ (458 ) $ 3,968 $ (209 ) $ 36,944 $ (667 )

Loans and Allowance for Loan 31

Loans and Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Loans and Allowance for Loan Losses [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	Loans consisted of the following segments as of December 31, 2017 and 2016 . 2017 2016 Commercial $ 347,482 $ 334,014 Real estate: Construction, land and land development 207,451 205,610 1-4 family residential first mortgages 51,044 47,184 Home equity 13,811 18,057 Commercial 886,114 788,000 Consumer and other 6,363 8,355 1,512,265 1,401,220 Net unamortized fees and costs (1,765 ) (1,350 ) $ 1,510,500 $ 1,399,870
Schedule of Loan Transactions with Related Parties [Table Text Block]	Loan transactions with related parties were as follows for the years ended December 31, 2017 and 2016 . 2017 2016 Balance, beginning of year $ 191,697 $ 138,706 New loans 28,975 60,712 Repayments (55,575 ) (7,721 ) Balance, end of year $ 165,097 $ 191,697
Schedule of Impaired Loans With and Without an Allowance [Table Text Block]	The following table summarizes the recorded investment in impaired loans by segment, broken down by loans with no related allowance and loans with a related allowance and the amount of that allowance as of December 31, 2017 and 2016 . December 31, 2017 December 31, 2016 Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance Related Allowance With no related allowance recorded: Commercial $ — $ — $ — $ 35 $ 35 $ — Real estate: Construction, land and land development — — — — — — 1-4 family residential first mortgages 91 91 — 108 108 — Home equity 172 172 — 41 41 — Commercial 220 220 — 335 335 — Consumer and other — — — — — — 483 483 — 519 519 — With an allowance recorded: Commercial — — — 91 91 91 Real estate: Construction, land and land development — — — — — — 1-4 family residential first mortgages — — — — — — Home equity 21 21 21 276 276 276 Commercial 118 118 118 136 136 136 Consumer and other — — — — — — 139 139 139 503 503 503 Total: Commercial — — — 126 126 91 Real estate: Construction, land and land development — — — — — — 1-4 family residential first mortgages 91 91 — 108 108 — Home equity 193 193 21 317 317 276 Commercial 338 338 118 471 471 136 Consumer and other — — — — — — Total impaired loans $ 622 $ 622 $ 139 $ 1,022 $ 1,022 $ 503 The balance of impaired loans at December 31, 2017 was composed of loans to five different borrowers, and the balance of impaired loans at December 31, 2016 was composed of loans to ten different borrowers. As of December 31, 2017 , $450 of total impaired loans to four of the borrowers were also considered impaired as of December 31, 2016 . The Company has no commitments to advance additional funds on any of the impaired loans. The following table summarizes the average recorded investment and interest income recognized on impaired loans by segment for the years ended December 31, 2017 , 2016 and 2015 . December 31, 2017 December 31, 2016 December 31, 2015 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized With no related allowance recorded: Commercial $ 19 $ — $ 3 $ — $ 116 $ — Real estate: Construction, land and land development — — 8 — 259 10 1-4 family residential first mortgages 99 — 212 1 311 1 Home equity 39 2 3 — — — Commercial 276 — 393 — 952 — Consumer and other — — — — 2 — 433 2 619 1 1,640 11 With an allowance recorded: Commercial 60 7 127 — 204 2 Real estate: Construction, land and land development — — — — 190 6 1-4 family residential first mortgages — — — — — — Home equity 177 1 263 — 237 — Commercial 127 — 145 — 164 — Consumer and other — — — — — — 364 8 535 — 795 8 Total: Commercial 79 7 130 — 320 2 Real estate: Construction, land and land development — — 8 — 449 16 1-4 family residential first mortgages 99 — 212 1 311 1 Home equity 216 3 266 — 237 — Commercial 403 — 538 — 1,116 — Consumer and other — — — — 2 — Total impaired loans $ 797 $ 10 $ 1,154 $ 1 $ 2,435 $ 19
Past Due Loans [Table Text Block]	The following tables provide an analysis of the payment status of the recorded investment in loans as of December 31, 2017 and 2016 . December 31, 2017 30-59 Days Past Due 60-89 Days Past Due 90 Days or More Past Due Total Past Due Current Nonaccrual Loans Total Loans Commercial $ 40 $ 20 $ — $ 60 $ 347,422 $ — $ 347,482 Real estate: Construction, land and land development — — — — 207,451 — 207,451 1-4 family residential first mortgages — 75 — 75 50,878 91 51,044 Home equity — — — — 13,618 193 13,811 Commercial — — — — 885,776 338 886,114 Consumer and other — — — — 6,363 — 6,363 Total $ 40 $ 95 $ — $ 135 $ 1,511,508 $ 622 $ 1,512,265 December 31, 2016 30-59 Days Past Due 60-89 Days Past Due 90 Days or More Past Due Total Past Due Current Nonaccrual Loans Total Loans Commercial $ 109 $ — $ — $ 109 $ 333,779 $ 126 $ 334,014 Real estate: Construction, land and land development — — — — 205,610 — 205,610 1-4 family residential first mortgages 64 — — 64 47,012 108 47,184 Home equity — — — — 17,740 317 18,057 Commercial — — — — 787,529 471 788,000 Consumer and other — — — — 8,355 — 8,355 Total $ 173 $ — $ — $ 173 $ 1,400,025 $ 1,022 $ 1,401,220
Troubled Debt Restructurings on Financing Receivables [Table Text Block]	TDR loans totaled $220 and $426 as of December 31, 2017 and 2016 , respectively, and were included in the nonaccrual category. There were no loan modifications considered to be TDR that occurred during the year ended December 31, 2017 or December 31, 2016 , and three loan modifications considered to be TDR that occurred during the year ended December 31, 2015 . The pre- and post-modification recorded investment in TDR loans that have occurred during the years ended December 31, 2017 , 2016 and 2015 , totaled $0 , $0 and $149 , respectively. The financial impact of charge-offs or specific reserves for these modified loans was immaterial. The recorded investment in TDR loans that have been modified within the twelve months ended December 31, 2017 , 2016 and 2015 , which have subsequently had a payment default, totaled $0 , $0 and $110 , respectively. A TDR loan is considered to have a payment default when it is past due 30 days or more.
Financing Receivable Credit Quality Indicators [Table Text Block]	The following tables show the recorded investment in loans by credit quality indicator and loan segment as of December 31, 2017 and 2016 . December 31, 2017 Pass Watch Substandard Doubtful Total Commercial $ 344,586 $ 901 $ 1,995 $ — $ 347,482 Real estate: Construction, land and land development 206,719 732 — — 207,451 1-4 family residential first mortgages 49,905 890 249 — 51,044 Home equity 13,466 54 291 — 13,811 Commercial 856,789 20,574 8,751 — 886,114 Consumer and other 6,327 36 — — 6,363 Total $ 1,477,792 $ 23,187 $ 11,286 $ — $ 1,512,265 December 31, 2016 Pass Watch Substandard Doubtful Total Commercial $ 329,366 $ 3,303 $ 1,345 $ — $ 334,014 Real estate: Construction, land and land development 204,572 — 1,038 — 205,610 1-4 family residential first mortgages 46,278 798 108 — 47,184 Home equity 17,646 — 411 — 18,057 Commercial 769,010 18,392 598 — 788,000 Consumer and other 8,355 — — — 8,355 Total $ 1,375,227 $ 22,493 $ 3,500 $ — $ 1,401,220
Allowance for Credit Losses on Financing Receivables [Table Text Block]	The following tables detail changes in the allowance for loan losses by segment for the years ended December 31, 2017 , 2016 and 2015 . 2017 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Beginning balance $ 3,881 $ 2,639 $ 317 $ 478 $ 8,697 $ 100 $ 16,112 Charge-offs (199 ) — — (176 ) — — (375 ) Recoveries 232 398 15 28 13 7 693 Provision (1) (48 ) (824 ) (13 ) (144 ) 1,060 (31 ) — Ending balance $ 3,866 $ 2,213 $ 319 $ 186 $ 9,770 $ 76 $ 16,430 2016 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Beginning balance $ 4,369 $ 2,338 $ 508 $ 481 $ 7,254 $ 17 $ 14,967 Charge-offs (125 ) (141 ) (93 ) — — (47 ) (406 ) Recoveries 218 217 59 36 13 8 551 Provision (1) (581 ) 225 (157 ) (39 ) 1,430 122 1,000 Ending balance $ 3,881 $ 2,639 $ 317 $ 478 $ 8,697 $ 100 $ 16,112 2015 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Beginning balance $ 4,415 $ 2,151 $ 466 $ 534 $ 6,013 $ 28 $ 13,607 Charge-offs (408 ) — (23 ) (2 ) — (6 ) (439 ) Recoveries 579 250 7 87 12 14 949 Provision (1) (217 ) (63 ) 58 (138 ) 1,229 (19 ) 850 Ending balance $ 4,369 $ 2,338 $ 508 $ 481 $ 7,254 $ 17 $ 14,967 (1) The negative provisions for the various segments are either related to the decline in outstanding balances in each of those portfolio segments during the time periods disclosed and/or improvement in the credit quality factors related to those portfolio segments.
Allowance for Loan Loss by Impairment Method [Table Text Block]	The following tables show a breakdown of the allowance for loan losses disaggregated on the basis of impairment analysis method by segment as of December 31, 2017 and 2016 . December 31, 2017 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Ending balance: Individually evaluated for impairment $ — $ — $ — $ 21 $ 118 $ — $ 139 Collectively evaluated for impairment 3,866 2,213 319 165 9,652 76 16,291 Total $ 3,866 $ 2,213 $ 319 $ 186 $ 9,770 $ 76 $ 16,430 December 31, 2016 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Ending balance: Individually evaluated for impairment $ 91 $ — $ — $ 276 $ 136 $ — $ 503 Collectively evaluated for impairment 3,790 2,639 317 202 8,561 100 15,609 Total $ 3,881 $ 2,639 $ 317 $ 478 $ 8,697 $ 100 $ 16,112
Loans by Impairment Method [Table Text Block]	The following tables show the recorded investment in loans, exclusive of unamortized fees and costs, disaggregated on the basis of impairment analysis method by segment as of December 31, 2017 and 2016 . December 31, 2017 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Ending balance: Individually evaluated for impairment $ — $ — $ 91 $ 193 $ 338 $ — $ 622 Collectively evaluated for impairment 347,482 207,451 50,953 13,618 885,776 6,363 1,511,643 Total $ 347,482 $ 207,451 $ 51,044 $ 13,811 $ 886,114 $ 6,363 $ 1,512,265 December 31, 2016 Real Estate Commercial Construction and Land 1-4 Family Residential Home Equity Commercial Consumer and Other Total Ending balance: Individually evaluated for impairment $ 126 $ — $ 108 $ 317 $ 471 $ — $ 1,022 Collectively evaluated for impairment 333,888 205,610 47,076 17,740 787,529 8,355 1,400,198 Total $ 334,014 $ 205,610 $ 47,184 $ 18,057 $ 788,000 $ 8,355 $ 1,401,220

Premises and Equipment, Net (Ta

Premises and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment [Table Text Block]	Premises and equipment consisted of the following as of December 31, 2017 and 2016 . 2017 2016 Land $ 4,323 $ 4,323 Buildings 14,423 14,344 Leasehold improvements 3,880 3,843 Furniture and equipment 7,946 7,637 30,572 30,147 Accumulated depreciation (7,550 ) (6,833 ) $ 23,022 $ 23,314

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Schedule of Maturities of Time Deposits [Table Text Block]	The scheduled maturities of time deposits were as follows as of December 31, 2017 . 2018 $ 133,323 2019 18,698 2020 8,451 2021 3,396 2022 5,789 $ 169,657

Federal Home Loan Bank Advanc34

Federal Home Loan Bank Advances (Tables)	12 Months Ended
	Dec. 31, 2017
Advances from Federal Home Loan Banks [Abstract]
Federal Home Loan Bank Advances Maturities Summary [Table Text Block]	The following table presents the terms of all FHLB long-term advances as of December 31, 2017 and 2016 . December 31, 2017 December 31, 2016 Maturity Interest Effective Interest Effective Date Variable/Fixed Rate Rate (1) Balance Rate Rate (1) Balance 1/29/2018 Fixed — — $ — 2.70 % 2.70 % $ 25,000 12/23/2019 Variable 1.93% 3.90% 25,000 1.28 % 3.26 % 25,000 6/22/2020 Variable 1.95% 4.09% 25,000 1.30 % 3.45 % 25,000 9/21/2020 Variable 1.95% 4.44% 30,000 1.30 % 4.44 % 30,000 80,000 105,000 Discount for modification (3,618 ) (5,114 ) Total FHLB advances, net of discount $ 76,382 $ 99,886 (1) The effective interest rate for the variable-rate advances includes the effects of the discount fee amortization and interest rate swaps, if applicable.

Long-term debt (Tables)

Long-term debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Instruments [Abstract]
Schedule of Maturities of Long-term Debt [Table Text Block]	Future required principal payments for long-term debt as of December 31, 2017 are shown in the table below. 2018 $ 2,614 2019 2,615 2020 2,616 2021 2,537 2022 12,535 $ 22,917

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The table below identifies the balance sheet category and fair values of the Company’s derivative instruments designated as cash flow hedges as of December 31, 2017 and 2016 . Notional Amount Fair Value Balance Sheet Category Weighted Average Receive Rate Weighted Average Pay Rate Maturity December 31, 2017 Interest rate swap $ 30,000 $ (86 ) Other Liabilities 1.95 % 2.52 % 9/21/2020 Interest rate swap (1) 20,000 895 Other Assets — % 4.81 % 9/30/2026 December 31, 2016 Interest rate swap $ 30,000 $ (496 ) Other Liabilities 1.30 % 2.52 % 9/21/2020 Interest rate swap (1) 20,000 1,068 Other Assets — % 4.81 % 9/30/2026 (1) This swap is a forward starting swap with a weighted average pay rate of 4.81 percent beginning September 30, 2018. No interest payments are required related to this swap until December 30, 2018.
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Table Text Block]	The following table identifies the pretax gains (losses) recognized on the Company’s derivative instruments designated as cash flow hedges for the years ended December 31, 2017 , 2016 and 2015 . Effective Portion Ineffective Portion Amount of Reclassified from AOCI into Income Recognized in Income on Derivatives Pretax Gain (Loss) Recognized in Amount of Amount of OCI Category Loss Category Gain (Loss) 2017 $ (66 ) Interest Expense $ (413 ) Other Income $ — 2016 $ 882 Interest Expense $ (573 ) Other Income $ — 2015 $ (1,144 ) Interest Expense $ (160 ) Other Income $ —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	The following table shows the components of income taxes for the years ended December 31, 2017 , 2016 and 2015 . 2017 2016 2015 Current: Federal $ 8,822 $ 8,220 $ 8,057 State 1,713 1,627 1,558 Deferred: Federal 2,527 115 112 State 306 (26 ) (30 ) Income taxes $ 13,368 $ 9,936 $ 9,697
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	Total income taxes for the years ended December 31, 2017 , 2016 and 2015 , differed from the amounts computed by applying the U.S. federal income tax rate of 35 percent to income before income taxes as shown in the following table. 2017 2016 2015 Amount Percent of Pretax Income Amount Percent of Pretax Income Amount Percent of Pretax Income Computed expected tax expense $ 12,753 35.0 % $ 11,533 35.0 % $ 11,004 35.0 % State income tax expense, net of federal income tax benefit 1,146 3.2 % 1,004 3.0 % 957 3.0 % Tax-exempt interest income (2,023 ) (5.6 )% (1,823 ) (5.5 )% (1,786 ) (5.7 )% Nondeductible interest expense to own tax-exempt securities 152 0.4 % 58 0.2 % 43 0.1 % Tax-exempt increase in cash value of life insurance and gains (336 ) (0.9 )% (381 ) (1.2 )% (254 ) (0.8 )% Stock compensation (261 ) (0.7 )% — — — — Effect of change in federal income tax rate 2,340 6.4 % — — — — Utilization of capital loss carryforwards — — — — (130 ) (0.4 )% Federal income tax credits (410 ) (1.1 )% (405 ) (1.2 )% (275 ) (0.9 )% Other, net 7 — (50 ) (0.1 )% 138 0.5 % Income taxes $ 13,368 36.7 % $ 9,936 30.2 % $ 9,697 30.8 %
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	Net deferred tax assets consisted of the following components as of December 31, 2017 and 2016 . 2017 2016 Deferred tax assets: Allowance for loan losses $ 4,108 $ 6,123 Net unrealized losses on securities available for sale 902 719 Intangibles 101 462 Accrued expenses 176 706 Restricted stock unit compensation 544 446 State net operating loss carryforward 1,379 1,271 Other 86 190 7,296 9,917 Deferred tax liabilities: Deferred loan costs 193 321 Net unrealized gains on interest rate swaps 139 80 Premises and equipment 792 1,027 Other 148 261 1,272 1,689 Net deferred tax assets before valuation allowance 6,024 8,228 Valuation allowance for deferred tax assets (1,379 ) (1,271 ) Net deferred tax assets $ 4,645 $ 6,957

Stock Compensation Plans (Table

Stock Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]	The following table includes a summary of nonvested RSU activity for the years ended December 31, 2017 , 2016 and 2015 . 2017 2016 2015 Weighted Weighted Weighted Average Average Average Grant Date Grant Date Grant Date Fair Value Fair Value Fair Value (actual amounts, not in thousands) Shares Per Share Shares Per Share Shares Per Share Nonvested shares, beginning balance 307,268 $ 17.46 261,833 $ 16.67 179,699 $ 13.39 Granted 138,500 22.06 141,000 18.44 139,500 19.59 Vested (106,468 ) 16.79 (95,565 ) 16.74 (57,366 ) 13.23 Forfeited — — — — — — Nonvested shares, ending balance 339,300 $ 19.55 307,268 $ 17.46 261,833 $ 16.67

Accumulated Other Comprehensi39

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Note 14. Accumulated Other Comprehensive Income (Loss) The following table summarizes the changes in the balances of each component of AOCI, net of tax, for the years ended December 31, 2017 , 2016 and 2015 . Unrealized Accumulated Unrealized Gains Other Gains (Losses) (Losses) on Comprehensive on Securities Derivatives Income (Loss) Balance, December 31, 2014 $ 416 $ (162 ) $ 254 Other comprehensive loss before reclassifications (21 ) (709 ) (730 ) Amounts reclassified from accumulated other comprehensive income (53 ) 99 46 Current period, other comprehensive loss (74 ) (610 ) (684 ) Balance, December 31, 2015 342 (772 ) (430 ) Other comprehensive income (loss) before reclassifications (1,394 ) 547 (847 ) Amounts reclassified from accumulated other comprehensive income (120 ) 355 235 Current period other comprehensive income (loss) (1,514 ) 902 (612 ) Balance, December 31, 2016 (1,172 ) 130 (1,042 ) Other comprehensive loss before reclassifications (697 ) (41 ) (738 ) Amounts reclassified from accumulated other comprehensive income (368 ) 256 (112 ) Current period other comprehensive income (loss) (1,065 ) 215 (850 ) Balance, December 31, 2017 $ (2,237 ) $ 345 $ (1,892 )

Regulatory Capital Requiremen40

Regulatory Capital Requirements (Tables)	12 Months Ended
	Dec. 31, 2017
Regulatory Capital Requirements [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]	The Company’s and West Bank’s capital amounts and ratios are presented in the following table as of December 31, 2017 and 2016 . Actual For Capital Adequacy Purposes For Capital Adequacy Purposes With Capital Conservation Buffer To Be Well-Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017: Total Capital (to Risk-Weighted Assets) Consolidated $ 216,420 11.76 % $ 147,169 8.00 % $ 170,164 9.25 % N/A N/A West Bank 235,570 12.82 % 147,049 8.00 % 170,026 9.25 % $ 183,812 10.00 % Tier 1 Capital (to Risk-Weighted Assets) Consolidated 199,990 10.87 % 110,377 6.00 % 133,372 7.25 % N/A N/A West Bank 219,140 11.92 % 110,287 6.00 % 133,263 7.25 % 147,049 8.00 % Common Equity Tier 1 Capital (to Risk-Weighted Assets) Consolidated 179,990 9.78 % 82,783 4.50 % 105,778 5.75 % N/A N/A West Bank 219,140 11.92 % 82,715 4.50 % 105,692 5.75 % 119,478 6.50 % Tier 1 Capital (to Average Assets) Consolidated 199,990 9.60 % 83,326 4.00 % 83,326 4.00 % N/A N/A West Bank 219,140 10.52 % 83,287 4.00 % 83,287 4.00 % 104,109 5.00 % As of December 31, 2016: Total Capital (to Risk-Weighted Assets) Consolidated $ 202,530 11.87 % $ 136,448 8.00 % $ 147,108 8.625 % N/A N/A West Bank 186,118 11.04 % 134,877 8.00 % 145,414 8.625 % $ 168,597 10.00 % Tier 1 Capital (to Risk-Weighted Assets) Consolidated 186,418 10.93 % 102,336 6.00 % 112,996 6.625 % N/A N/A West Bank 170,006 10.08 % 101,158 6.00 % 111,695 6.625 % 134,877 8.00 % Common Equity Tier 1 Capital (to Risk-Weighted Assets) Consolidated 166,418 9.76 % 76,752 4.50 % 87,412 5.125 % N/A N/A West Bank 170,006 10.08 % 75,868 4.50 % 86,406 5.125 % 109,588 6.50 % Tier 1 Capital (to Average Assets) Consolidated 186,418 10.14 % 73,530 4.00 % 73,530 4.00 % N/A N/A West Bank 170,006 9.34 % 72,807 4.00 % 72,807 4.00 % 91,009 5.00 %

Commitments and Contingencies41

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Total estimated minimum rental commitments were as follows as of December 31, 2017 . 2018 $ 1,509 2019 1,547 2020 1,547 2021 1,493 2022 1,462 Thereafter 5,341 $ 12,899
Summary Of Outstanding Commitments To Extend Credit And Letters Of Credit [Table Text Block]	The Company’s commitments consisted of the following approximate amounts as of December 31, 2017 and 2016 . 2017 2016 Commitments to extend credit $ 617,949 $ 614,681 Standby letters of credit 5,996 5,487 $ 623,945 $ 620,168

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring Basis [Table Text Block]	The following tables present the balances of assets and liabilities measured at fair value on a recurring basis by level as of December 31, 2017 and 2016 . 2017 Description Total Level 1 Level 2 Level 3 Financial assets: Investment securities available for sale: State and political subdivisions $ 146,313 $ — $ 146,313 $ — Collateralized mortgage obligations 159,932 — 159,932 — Mortgage-backed securities 60,429 — 60,429 — Asset-backed securities 45,195 — 45,195 — Trust preferred security 2,006 — 2,006 — Corporate notes 30,344 — 30,344 — Derivative instrument, interest rate swap 895 — 895 — Financial liabilities: Derivative instrument, interest rate swap $ 86 $ — $ 86 $ — 2016 Description Total Level 1 Level 2 Level 3 Financial assets: Investment securities available for sale: U.S. government agencies and corporations $ 2,593 $ — $ 2,593 $ — State and political subdivisions 64,336 — 64,336 — Collateralized mortgage obligations 101,950 — 101,950 — Mortgage-backed securities 80,158 — 80,158 — Trust preferred security 1,250 — 1,250 — Corporate notes 10,350 10,050 300 — Derivative instrument, interest rate swap 1,068 — 1,068 — Financial liabilities: Derivative instrument, interest rate swap $ 496 $ — $ 496 $ —
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	Certain assets are measured at fair value on a nonrecurring basis. That is, they are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment). As of December 31, 2017 and 2016 , impaired loans with a net book value of $0 and $0 , respectively, for which a fair value adjustment was recorded, were classified as Level 3.
Fair Value, by Balance Sheet Grouping [Table Text Block]	The following table presents the carrying amounts and approximate fair values of financial assets and liabilities as of December 31, 2017 and 2016 . 2017 2016 Fair Value Hierarchy Level Carrying Amount Approximate Fair Value Carrying Amount Approximate Fair Value Financial assets: Cash and due from banks Level 1 $ 34,952 $ 34,952 $ 40,943 $ 40,943 Federal funds sold Level 1 12,997 12,997 35,893 35,893 Investment securities available for sale See previous table 444,219 444,219 260,637 260,637 Investment securities held to maturity Level 2 45,527 45,890 48,386 47,789 Federal Home Loan Bank stock Level 1 9,174 9,174 10,771 10,771 Loans, net Level 2 1,494,070 1,490,166 1,383,758 1,382,569 Accrued interest receivable Level 1 7,344 7,344 5,321 5,321 Interest rate swap See previous table 895 895 1,068 1,068 Financial liabilities: Deposits Level 2 $ 1,810,813 $ 1,810,924 $ 1,546,605 $ 1,546,307 Federal funds purchased Level 1 545 545 9,690 9,690 Subordinated notes, net Level 2 20,412 15,357 20,398 12,703 Federal Home Loan Bank advances, net Level 2 76,382 76,382 99,886 99,959 Long-term debt, net Level 2 22,917 22,860 5,126 5,054 Accrued interest payable Level 1 736 736 280 280 Interest rate swap See previous table 86 86 496 496 Off-balance-sheet financial instruments: Commitments to extend credit Level 3 — — — — Standby letters of credit Level 3 — — — —

West Bancorporation, Inc. (Pa43

West Bancorporation, Inc. (Parent Company Only) Condensed Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule of Condensed Balance Sheet [Table Text Block]	Balance Sheets December 31, 2017 and 2016 2017 2016 ASSETS Cash $ 3,226 $ 3,945 Investment in West Bank 216,693 168,302 Investment in West Bancorporation Capital Trust I 619 619 Premises, net — 18,194 Other assets 1,034 1,256 Total assets $ 221,572 $ 192,316 LIABILITIES AND STOCKHOLDERS’ EQUITY LIABILITIES Accrued expenses and other liabilities $ 562 $ 1,416 Subordinated notes, net 20,412 20,398 Long-term debt, net 22,500 5,126 Total liabilities 43,474 26,940 STOCKHOLDERS’ EQUITY Preferred stock — — Common stock 3,000 3,000 Additional paid-in capital 23,463 21,462 Retained earnings 153,527 141,956 Accumulated other comprehensive loss (1,892 ) (1,042 ) Total stockholders’ equity 178,098 165,376 Total liabilities and stockholders’ equity $ 221,572 $ 192,316
Schedule of Condensed Income Statement [Table Text Block]	Statements of Income Years Ended December 31, 2017, 2016 and 2015 2017 2016 2015 Operating income: Equity in net income of West Bank $ 23,933 $ 23,544 $ 22,546 Equity in net income of West Bancorporation Capital Trust I 27 23 21 Intercompany rental income 333 503 207 Other rental income 21 50 43 Total operating income 24,314 24,120 22,817 Operating expenses: Interest on subordinated notes 901 728 705 Interest on long-term debt 517 145 232 Occupancy 187 280 170 Other expenses 602 443 496 Total operating expenses 2,207 1,596 1,603 Income before income taxes 22,107 22,524 21,214 Income tax benefits (963 ) (492 ) (528 ) Net income $ 23,070 $ 23,016 $ 21,742
Schedule of Condensed Cash Flow Statement [Table Text Block]	Statements of Cash Flows Years Ended December 31, 2017, 2016 and 2015 2017 2016 2015 Cash Flows from Operating Activities: Net income $ 23,070 $ 23,016 $ 21,742 Adjustments to reconcile net income to net cash provided by operating activities: Equity in net income of West Bank (23,933 ) (23,544 ) (22,546 ) Equity in net income of West Bancorporation Capital Trust I (27 ) (23 ) (21 ) Dividends received from West Bank 16,800 14,400 13,900 Dividends received from West Bancorporation Capital Trust I 27 23 21 Amortization 17 20 23 Depreciation 178 244 139 Deferred income tax (benefits) (240 ) 97 99 Change in assets and liabilities: (Increase) decrease in other assets 50 (79 ) 1,436 Increase (decrease) in accrued expenses and other liabilities (549 ) 641 (31 ) Net cash provided by operating activities 15,393 14,795 14,762 Cash Flows from Investing Activities: Proceeds from sales of premises 18,032 — — Purchases of premises (16 ) (10,539 ) (1,386 ) Proceeds from sales of other real estate owned — — 2,227 Proceeds from settlement of other assets — — 3,593 Capital contribution to West Bank (40,000 ) — — Net cash provided by (used in) investing activities (21,984 ) (10,539 ) 4,434 Cash Flows from Financing Activities: Proceeds from long-term debt 22,000 — — Principal payments on long-term debt (4,629 ) (3,286 ) (4,261 ) Common stock cash dividends (11,499 ) (10,800 ) (9,952 ) Net cash provided by (used in) financing activities 5,872 (14,086 ) (14,213 ) Net increase (decrease) in cash (719 ) (9,830 ) 4,983 Cash: Beginning 3,945 13,775 8,792 Ending $ 3,226 $ 3,945 $ 13,775

Selected Quarterly Financial 44

Selected Quarterly Financial Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Selected Quarterly Financial Information [Abstract]
Schedule of Quarterly Financial Information [Table Text Block]	2017 Three months ended March 31 June 30 September 30 December 31 Interest income $ 16,791 $ 18,166 $ 18,560 $ 19,517 Interest expense 2,402 3,073 3,529 3,973 Net interest income 14,389 15,093 15,031 15,544 Provision for loan losses — — — — Net interest income after provision for loan losses 14,389 15,093 15,031 15,544 Noninterest income 2,160 2,316 2,264 1,908 Noninterest expense 8,043 8,172 8,020 8,032 Income before income taxes 8,506 9,237 9,275 9,420 Income taxes 2,400 2,872 2,870 5,226 Net income $ 6,106 $ 6,365 $ 6,405 $ 4,194 Basic earnings per common share $ 0.38 $ 0.39 $ 0.40 $ 0.26 Diluted earnings per common share $ 0.37 $ 0.39 $ 0.39 $ 0.26 2016 Three months ended March 31 June 30 September 30 December 31 Interest income $ 15,524 $ 16,209 $ 16,696 $ 16,565 Interest expense 1,825 1,936 1,975 2,140 Net interest income 13,699 14,273 14,721 14,425 Provision for loan losses 200 500 200 100 Net interest income after provision for loan losses 13,499 13,773 14,521 14,325 Noninterest income 2,230 1,903 1,919 1,930 Noninterest expense 7,799 7,819 7,993 7,537 Income before income taxes 7,930 7,857 8,447 8,718 Income taxes 2,234 2,381 2,634 2,687 Net income $ 5,696 $ 5,476 $ 5,813 $ 6,031 Basic earnings per common share $ 0.35 $ 0.34 $ 0.36 $ 0.37 Diluted earnings per common share $ 0.35 $ 0.34 $ 0.36 $ 0.37

Organization and Nature of Bu45

Organization and Nature of Business and Summary of Significant Accounting Policies (Branches) (Details)	Dec. 31, 2017Bank_branches
Des Moines, Iowa metropolitan area branches, excluding main [Member]
Number of bank branches by location [Line Items]
Number of bank branches	7
Iowa City, Iowa [Member]
Number of bank branches by location [Line Items]
Number of bank branches	1
Coralville, Iowa [Member]
Number of bank branches by location [Line Items]
Number of bank branches	1
Rochester, Minnesota [Member]
Number of bank branches by location [Line Items]
Number of bank branches	1

Organization and Nature of Bu46

Organization and Nature of Business and Summary of Significant Accounting Policies Organization and Nature of Business and Summary of Significant Accounting Policies (Segments) (Details)	12 Months Ended
	Dec. 31, 2017number_of_operating_segments
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of Operating Segments	1

Organization and Nature of Bu47

Organization and Nature of Business and Summary of Significant Accounting Policies (FHLB stock) (Details) - Federal Home Loan Bank stock [Member]	Dec. 31, 2017USD ($)
Schedule of Cost-method Investments [Line Items]
Federal Home Loan Bank stock, percent of total assets required	0.12%
Federal Home Loan Bank stock, percent of outstanding advances required	4.00%
Quoted market value	$ 0

Organization and Nature of Bu48

Organization and Nature of Business and Summary of Significant Accounting Policies (Useful Lives) (Details) - Maximum [Member]	12 Months Ended
	Dec. 31, 2017
Buildings [Member]
Premises and equipment [Line Items]
Premises and equipment, useful life	40 years
Furniture and equipment [Member]
Premises and equipment [Line Items]
Premises and equipment, useful life	10 years

Organization and Nature of Bu49

Organization and Nature of Business and Summary of Significant Accounting Policies (OREO) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Other real estate owned, included in other assets	$ 0	$ 0

Organization and Nature of Bu50

Organization and Nature of Business and Summary of Significant Accounting Policies (Trust assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Trust assets	$ 306,974	$ 251,767

Organization and Nature of Bu51

Organization and Nature of Business and Summary of Significant Accounting Policies Organization and Nature of Business and Summary of Significant Accounting Policies (RSUs) (Details) - Restricted stock units (RSUs) [Member] - Common Stock [Member]	12 Months Ended
	Dec. 31, 2016shares
Stock compensation plan [Line Items]
Projected forfeitures on restricted stock awards	0
Stock Issued During Period, Shares, Restricted Stock Award, Forfeited	0

Earnings per Common Share (Deta

Earnings per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income	$ 4,194	$ 6,405	$ 6,365	$ 6,106	$ 6,031	$ 5,813	$ 5,476	$ 5,696	$ 23,070	$ 23,016	$ 21,742
Weighted average common shares outstanding (shares)									16,194	16,117	16,050
Weighted average effect of restricted stock units outstanding (shares)									141	54	46
Diluted weighted average common shares outstanding (shares)									16,335	16,171	16,096
Basic earnings per common share	$ 0.26	$ 0.40	$ 0.39	$ 0.38	$ 0.37	$ 0.36	$ 0.34	$ 0.35	$ 1.42	$ 1.43	$ 1.35
Diluted earnings per common share	$ 0.26	$ 0.39	$ 0.39	$ 0.37	$ 0.37	$ 0.36	$ 0.34	$ 0.35	$ 1.41	$ 1.42	$ 1.35
Number of anti-dilutive common stock equivalents excluded from diluted earnings per share computation									0	102	140

Investment Securities Available

Investment Securities Available-for-Sale by Security Type (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, amortized cost	$ 447,869	$ 262,837
Investment securities available for sale, gross unrealized gains	1,315	1,066
Investment securities available for sale, gross unrealized losses	(4,965)	(3,266)
Investment securities available for sale	444,219	260,637
U.S. government agencies and corporations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, amortized cost		2,524
Investment securities available for sale, gross unrealized gains		69
Investment securities available for sale, gross unrealized losses		0
Investment securities available for sale		2,593
State and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, amortized cost	146,331	64,551
Investment securities available for sale, gross unrealized gains	928	376
Investment securities available for sale, gross unrealized losses	(946)	(591)
Investment securities available for sale	146,313	64,336
Collateralized mortgage obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, amortized cost	162,631	103,038
Investment securities available for sale, gross unrealized gains	28	255
Investment securities available for sale, gross unrealized losses	(2,727)	(1,343)
Investment securities available for sale	159,932	101,950
Mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, amortized cost	60,956	80,614
Investment securities available for sale, gross unrealized gains	20	341
Investment securities available for sale, gross unrealized losses	(547)	(797)
Investment securities available for sale	60,429	80,158
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, amortized cost	45,539
Investment securities available for sale, gross unrealized gains	8
Investment securities available for sale, gross unrealized losses	(352)
Investment securities available for sale	45,195
Trust preferred security [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, amortized cost	2,134	1,784
Investment securities available for sale, gross unrealized gains	0	0
Investment securities available for sale, gross unrealized losses	(128)	(534)
Investment securities available for sale	2,006	1,250
Corporate notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, amortized cost	30,278	10,326
Investment securities available for sale, gross unrealized gains	331	25
Investment securities available for sale, gross unrealized losses	(265)	(1)
Investment securities available for sale	$ 30,344	$ 10,350

Investment Securities Held-to-M

Investment Securities Held-to-Maturity by Security Type (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Investment securities held to maturity	$ 45,527	$ 48,386
Investment securities held to maturity, fair value	45,890	47,789
State and political subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Investment securities held to maturity	45,527	48,386
Investment securities held to maturity, gross unrealized gains	460	70
Investment securities held to maturity, gross unrealized losses	(97)	(667)
Investment securities held to maturity, fair value	$ 45,890	$ 47,789

Investment Securities Contractu

Investment Securities Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Investment Securities Available for Sale, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Due in one year or less, amortized cost	$ 110
Due after one year through five years, amortized cost	2,355
Due after five years through ten years, amortized cost	41,525
Due after ten years, amortized cost	134,753
Subtotal before securities without single maturities, amortized cost	178,743
Collateralized mortgage obligations, mortgage-backed and asset-backed securities, amortized cost	269,126
Investment securities available for sale, amortized cost	447,869	$ 262,837
Investment Securities Available for Sale, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Due in one year or less, fair value	110
Due after one year through five years, fair value	2,358
Due after five years through ten years, fair value	41,710
Due after ten years, fair value	134,485
Subtotal before securities without single maturities, fair value	178,663
Collateralized mortgage obligations, mortgage-backed and asset-backed securities, fair value	265,556
Investment securities available for sale, fair value	444,219	260,637
Investment Securities Held to Maturity, Debt Maturities, Net Carrying Amount [Abstract]
Due after one year through five years, amortized cost	1,594
Due after five years through ten years, amortized cost	26,621
Due after ten years, amortized cost	17,312
Investment securities held to maturity, amortized cost	45,527	48,386
Investment Securities Held to Maturity, Debt Maturities, Single Maturity Date, Fair Value, Rolling Maturity [Abstract]
Due after one year through five years, fair value	1,588
Due after five years through ten years, fair value	26,798
Due after ten years, fair value	17,504
Investment securities held to maturity, fair value	$ 45,890	$ 47,789

Investment Securities Detail of

Investment Securities Detail of Sale of Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Available-for-sale Securities [Abstract]
Proceeds from sales	$ 108,584	$ 3,054	$ 16,946
Gross gains on sales	752	66	54
Gross losses on sales	$ 426	$ 0	$ 7

Investment Securities Gross Unr

Investment Securities Gross Unrealized Losses - AFS (Details) $ in Thousands	Dec. 31, 2017USD ($)securities	Dec. 31, 2016USD ($)
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, continuous unrealized loss position, less than 12 months, fair value	$ 301,637	$ 172,394
Investment securities available for sale, continuous unrealized loss position, less than 12 months, gross unrealized losses	(3,693)	(2,644)
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, fair value	48,402	3,788
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, gross unrealized losses	(1,272)	(622)
Investment securities available for sale, total, continuous unrealized loss position, fair value	350,039	176,182
Investment securities available for sale, total, continuous unrealized loss position, gross unrealized losses	(4,965)	(3,266)
State and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, continuous unrealized loss position, less than 12 months, fair value	86,750	34,903
Investment securities available for sale, continuous unrealized loss position, less than 12 months, gross unrealized losses	(946)	(591)
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, fair value	0	0
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, gross unrealized losses	0	0
Investment securities available for sale, total, continuous unrealized loss position, fair value	86,750	34,903
Investment securities available for sale, total, continuous unrealized loss position, gross unrealized losses	(946)	(591)
Collateralized mortgage obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, continuous unrealized loss position, less than 12 months, fair value	107,526	75,771
Investment securities available for sale, continuous unrealized loss position, less than 12 months, gross unrealized losses	(1,583)	(1,255)
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, fair value	46,396	2,538
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, gross unrealized losses	(1,144)	(88)
Investment securities available for sale, total, continuous unrealized loss position, fair value	153,922	78,309
Investment securities available for sale, total, continuous unrealized loss position, gross unrealized losses	$ (2,727)	(1,343)
Investment securities available for sale in unrealized loss positions, qualitative disclosure, number of positions | securities	38
Mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, continuous unrealized loss position, less than 12 months, fair value	$ 53,974	60,221
Investment securities available for sale, continuous unrealized loss position, less than 12 months, gross unrealized losses	(547)	(797)
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, fair value	0	0
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, gross unrealized losses	0	0
Investment securities available for sale, total, continuous unrealized loss position, fair value	53,974	60,221
Investment securities available for sale, total, continuous unrealized loss position, gross unrealized losses	$ (547)	(797)
Investment securities available for sale in unrealized loss positions, qualitative disclosure, number of positions | securities	15
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, continuous unrealized loss position, less than 12 months, fair value	$ 38,652
Investment securities available for sale, continuous unrealized loss position, less than 12 months, gross unrealized losses	(352)
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, fair value	0
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, gross unrealized losses	0
Investment securities available for sale, total, continuous unrealized loss position, fair value	38,652
Investment securities available for sale, total, continuous unrealized loss position, gross unrealized losses	$ (352)
Investment securities available for sale in unrealized loss positions, qualitative disclosure, number of positions | securities	6
Trust preferred security [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, continuous unrealized loss position, less than 12 months, fair value	$ 0	0
Investment securities available for sale, continuous unrealized loss position, less than 12 months, gross unrealized losses	0	0
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, fair value	2,006	1,250
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, gross unrealized losses	(128)	(534)
Investment securities available for sale, total, continuous unrealized loss position, fair value	2,006	1,250
Investment securities available for sale, total, continuous unrealized loss position, gross unrealized losses	$ (128)	(534)
Investment securities available for sale in unrealized loss positions, qualitative disclosure, number of positions | securities	1
Corporate notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available for sale, continuous unrealized loss position, less than 12 months, fair value	$ 14,735	1,499
Investment securities available for sale, continuous unrealized loss position, less than 12 months, gross unrealized losses	(265)	(1)
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, fair value	0	0
Investment securities available for sale, continuous unrealized loss position, 12 months or longer, gross unrealized losses	0	0
Investment securities available for sale, total, continuous unrealized loss position, fair value	14,735	1,499
Investment securities available for sale, total, continuous unrealized loss position, gross unrealized losses	$ (265)	$ (1)
Investment securities available for sale in unrealized loss positions, qualitative disclosure, number of positions | securities	4

Investment Securities Gross U58

Investment Securities Gross Unrealized Losses - HTM (Details) - State and political subdivisions [Member] $ in Thousands	Dec. 31, 2017USD ($)securities	Dec. 31, 2016USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Investment securities held to maturity, continuous unrealized loss position, less than 12 months, fair value	$ 12,611	$ 32,976
Investment securities held to maturity, continuous unrealized loss position, less than 12 months, gross unrealized losses	(70)	(458)
Investment securities held to maturity, continuous unrealized loss position, 12 months or longer, fair value	1,740	3,968
Investment securities held to maturity, continuous unrealized loss position, 12 months or longer, gross unrealized losses	(27)	(209)
Investment securities held to maturity, total, continuous unrealized loss position, fair value	14,351	36,944
Investment securities held to maturity, total, continuous unrealized loss position, gross unrealized losses	$ (97)	$ (667)
Investment securities held to maturity in unrealized loss positions, qualitative disclosure, number of positions | securities	146

Investment Securities Other Nar

Investment Securities Other Narratives (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Securities pledged as collateral at amortized cost	$ 120,338	$ 141,995

Loans and Allowance for Loan 60

Loans and Allowance for Loan Losses Schedule of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loans Receivable [Line Items]
Loans	$ 1,512,265	$ 1,401,220
Net unamortized fees and costs	(1,765)	(1,350)
Loans, net of unamortized fees and costs	1,510,500	1,399,870
Loans with fixed rates of interest	997,642	911,067
Loans with variable rates of interest	514,623	490,153
Commercial [Member]
Loans Receivable [Line Items]
Loans	347,482	334,014
Real Estate [Member]
Loans Receivable [Line Items]
Loans pledged as collateral	810,000	680,000
Construction, land and land development [Member]
Loans Receivable [Line Items]
Loans	207,451	205,610
1-4 family residential first mortgages [Member]
Loans Receivable [Line Items]
Loans	51,044	47,184
Home equity [Member]
Loans Receivable [Line Items]
Loans	13,811	18,057
Commercial real estate [Member]
Loans Receivable [Line Items]
Loans	886,114	788,000
Consumer and other [Member]
Loans Receivable [Line Items]
Loans	$ 6,363	$ 8,355

Loans and Allowance for Loan 61

Loans and Allowance for Loan Losses Schedule of Loan Transactions with Related Parties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Loans and Leases Receivable, Related Parties [Roll Forward]
Related party loans, due from related party, beginning of year	$ 191,697	$ 138,706
Related party loans, new loans	28,975	60,712
Related party loans, repayments	(55,575)	(7,721)
Related party loans, due from related party, end of year	$ 165,097	$ 191,697

Loans and Allowance for Loan 62

Loans and Allowance for Loan Losses Schedule of Impaired Loans With and Without an Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans, Impaired [Line Items]
Impaired loans, with no related allowance, recorded investment	$ 483	$ 519
Impaired loans, with no related allowance, unpaid principal balance	483	519
Impaired loans, with related allowance, recorded investment	139	503
Impaired loans, with related allowance, unpaid principal balance	139	503
Impaired loans, recorded investment	622	1,022
Impaired loans, unpaid principal balance	622	1,022
Impaired loans, related allowance	139	503
Impaired loans, with no related allowance, average recorded investment	433	619	$ 1,640
Impaired loans, with no related allowance, interest income, accrual method	2	1	11
Impaired loans, with related allowance, average recorded investment	364	535	795
Impaired loans, with related allowance, interest income, accrual method	8	0	8
Impaired loans, average recorded investment	797	1,154	2,435
Impaired loans, interest income, accrual method	10	1	19
Impaired loans, interest lost on nonaccrual loans	47	72	128
Commercial [Member]
Loans, Impaired [Line Items]
Impaired loans, with no related allowance, recorded investment	0	35
Impaired loans, with no related allowance, unpaid principal balance	0	35
Impaired loans, with related allowance, recorded investment	0	91
Impaired loans, with related allowance, unpaid principal balance	0	91
Impaired loans, recorded investment	0	126
Impaired loans, unpaid principal balance	0	126
Impaired loans, related allowance	0	91
Impaired loans, with no related allowance, average recorded investment	19	3	116
Impaired loans, with no related allowance, interest income, accrual method	0	0	0
Impaired loans, with related allowance, average recorded investment	60	127	204
Impaired loans, with related allowance, interest income, accrual method	7	0	2
Impaired loans, average recorded investment	79	130	320
Impaired loans, interest income, accrual method	7	0	2
Construction, land and land development [Member]
Loans, Impaired [Line Items]
Impaired loans, with no related allowance, recorded investment	0	0
Impaired loans, with no related allowance, unpaid principal balance	0	0
Impaired loans, with related allowance, recorded investment	0	0
Impaired loans, with related allowance, unpaid principal balance	0	0
Impaired loans, recorded investment	0	0
Impaired loans, unpaid principal balance	0	0
Impaired loans, related allowance	0	0
Impaired loans, with no related allowance, average recorded investment	0	8	259
Impaired loans, with no related allowance, interest income, accrual method	0	0	10
Impaired loans, with related allowance, average recorded investment	0	0	190
Impaired loans, with related allowance, interest income, accrual method	0	0	6
Impaired loans, average recorded investment	0	8	449
Impaired loans, interest income, accrual method	0	0	16
1-4 family residential first mortgages [Member]
Loans, Impaired [Line Items]
Impaired loans, with no related allowance, recorded investment	91	108
Impaired loans, with no related allowance, unpaid principal balance	91	108
Impaired loans, with related allowance, recorded investment	0	0
Impaired loans, with related allowance, unpaid principal balance	0	0
Impaired loans, recorded investment	91	108
Impaired loans, unpaid principal balance	91	108
Impaired loans, related allowance	0	0
Impaired loans, with no related allowance, average recorded investment	99	212	311
Impaired loans, with no related allowance, interest income, accrual method	0	1	1
Impaired loans, with related allowance, average recorded investment	0	0	0
Impaired loans, with related allowance, interest income, accrual method	0	0	0
Impaired loans, average recorded investment	99	212	311
Impaired loans, interest income, accrual method	0	1	1
Home equity [Member]
Loans, Impaired [Line Items]
Impaired loans, with no related allowance, recorded investment	172	41
Impaired loans, with no related allowance, unpaid principal balance	172	41
Impaired loans, with related allowance, recorded investment	21	276
Impaired loans, with related allowance, unpaid principal balance	21	276
Impaired loans, recorded investment	193	317
Impaired loans, unpaid principal balance	193	317
Impaired loans, related allowance	21	276
Impaired loans, with no related allowance, average recorded investment	39	3	0
Impaired loans, with no related allowance, interest income, accrual method	2	0	0
Impaired loans, with related allowance, average recorded investment	177	263	237
Impaired loans, with related allowance, interest income, accrual method	1	0	0
Impaired loans, average recorded investment	216	266	237
Impaired loans, interest income, accrual method	3	0	0
Commercial real estate [Member]
Loans, Impaired [Line Items]
Impaired loans, with no related allowance, recorded investment	220	335
Impaired loans, with no related allowance, unpaid principal balance	220	335
Impaired loans, with related allowance, recorded investment	118	136
Impaired loans, with related allowance, unpaid principal balance	118	136
Impaired loans, recorded investment	338	471
Impaired loans, unpaid principal balance	338	471
Impaired loans, related allowance	118	136
Impaired loans, with no related allowance, average recorded investment	276	393	952
Impaired loans, with no related allowance, interest income, accrual method	0	0	0
Impaired loans, with related allowance, average recorded investment	127	145	164
Impaired loans, with related allowance, interest income, accrual method	0	0	0
Impaired loans, average recorded investment	403	538	1,116
Impaired loans, interest income, accrual method	0	0	0
Consumer and other [Member]
Loans, Impaired [Line Items]
Impaired loans, with no related allowance, recorded investment	0	0
Impaired loans, with no related allowance, unpaid principal balance	0	0
Impaired loans, with related allowance, recorded investment	0	0
Impaired loans, with related allowance, unpaid principal balance	0	0
Impaired loans, recorded investment	0	0
Impaired loans, unpaid principal balance	0	0
Impaired loans, related allowance	0	0
Impaired loans, with no related allowance, average recorded investment	0	0	2
Impaired loans, with no related allowance, interest income, accrual method	0	0	0
Impaired loans, with related allowance, average recorded investment	0	0	0
Impaired loans, with related allowance, interest income, accrual method	0	0	0
Impaired loans, average recorded investment	0	0	2
Impaired loans, interest income, accrual method	$ 0	$ 0	$ 0

Loans and Allowance for Loan 63

Loans and Allowance for Loan Losses Impaired Loans (Details) $ in Thousands	Dec. 31, 2017USD ($)Borrowers	Dec. 31, 2016Borrowers
Loans and Allowance for Loan Losses [Abstract]
Impaired loans, number of borrowers | Borrowers	5	10
Impaired loans also impaired at end of prior year, number of borrowers | Borrowers	4
Impaired loans also impaired at end of prior year | $	$ 450
Impaired loans, commitment to lend | $	$ 0

Loans and Allowance for Loan 64

Loans and Allowance for Loan Losses Schedule of Past Due Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	$ 135	$ 173
Loans, recorded investment, current	1,511,508	1,400,025
Loans, recorded investment, nonaccrual status	622	1,022
Loans	1,512,265	1,401,220
Commercial [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	60	109
Loans, recorded investment, current	347,422	333,779
Loans, recorded investment, nonaccrual status	0	126
Loans	347,482	334,014
Construction, land and land development [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, recorded investment, current	207,451	205,610
Loans, recorded investment, nonaccrual status	0	0
Loans	207,451	205,610
1-4 family residential first mortgages [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	75	64
Loans, recorded investment, current	50,878	47,012
Loans, recorded investment, nonaccrual status	91	108
Loans	51,044	47,184
Home equity [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, recorded investment, current	13,618	17,740
Loans, recorded investment, nonaccrual status	193	317
Loans	13,811	18,057
Commercial real estate [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, recorded investment, current	885,776	787,529
Loans, recorded investment, nonaccrual status	338	471
Loans	886,114	788,000
Consumer and other [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, recorded investment, current	6,363	8,355
Loans, recorded investment, nonaccrual status	0	0
Loans	6,363	8,355
Loans, 30 to 59 days past due [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	40	173
Loans, 30 to 59 days past due [Member] | Commercial [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	40	109
Loans, 30 to 59 days past due [Member] | Construction, land and land development [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 30 to 59 days past due [Member] | 1-4 family residential first mortgages [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	64
Loans, 30 to 59 days past due [Member] | Home equity [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 30 to 59 days past due [Member] | Commercial real estate [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 30 to 59 days past due [Member] | Consumer and other [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 60 to 89 days past due [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	95	0
Loans, 60 to 89 days past due [Member] | Commercial [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	20	0
Loans, 60 to 89 days past due [Member] | Construction, land and land development [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 60 to 89 days past due [Member] | 1-4 family residential first mortgages [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	75	0
Loans, 60 to 89 days past due [Member] | Home equity [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 60 to 89 days past due [Member] | Commercial real estate [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 60 to 89 days past due [Member] | Consumer and other [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 90 or more days past due [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 90 or more days past due [Member] | Commercial [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 90 or more days past due [Member] | Construction, land and land development [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 90 or more days past due [Member] | 1-4 family residential first mortgages [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 90 or more days past due [Member] | Home equity [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 90 or more days past due [Member] | Commercial real estate [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	0	0
Loans, 90 or more days past due [Member] | Consumer and other [Member]
Loans, Recorded Investment, Past Due [Line Items]
Loans, recorded investment, past due	$ 0	$ 0

Loans and Allowance for Loan 65

Loans and Allowance for Loan Losses Schedule of Troubled Debt Restructured Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loans and Allowance for Loan Losses [Abstract]
Troubled debt restructured loans included in nonaccrual	$ 220	$ 426
Troubled debt restructured loans	$ 220	$ 426

Loans and Allowance for Loan 66

Loans and Allowance for Loan Losses Schedule of Troubled Debt Restructured Loan Modifications (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)loans	Dec. 31, 2016USD ($)loans	Dec. 31, 2015USD ($)loans
Loans and Allowance for Loan Losses [Abstract]
Troubled debt restructured loan modifications, pre-modification recorded investment	$ 0	$ 0	$ 149
Troubled debt restructured loan modifications, post-modification recorded investment	$ 0	$ 0	$ 149
Troubled debt restructured loan modifications, number | loans	0	0	3

Loans and Allowance for Loan 67

Loans and Allowance for Loan Losses Schedule of Troubled Debt Restructured Loans that Subsequently Defaulted (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans and Allowance for Loan Losses [Abstract]
Troubled debt restructured loans, subsequent default, recorded investment	$ 0	$ 0	$ 110

Loans and Allowance for Loan 68

Loans and Allowance for Loan Losses Schedule of Loans by Credit Quality Indicator (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loans, Recorded Investment [Line Items]
Loans	$ 1,512,265	$ 1,401,220
Commercial [Member]
Loans, Recorded Investment [Line Items]
Loans	347,482	334,014
Construction, land and land development [Member]
Loans, Recorded Investment [Line Items]
Loans	207,451	205,610
1-4 family residential first mortgages [Member]
Loans, Recorded Investment [Line Items]
Loans	51,044	47,184
Home Equity Loan [Member]
Loans, Recorded Investment [Line Items]
Loans	13,811	18,057
Commercial real estate [Member]
Loans, Recorded Investment [Line Items]
Loans	886,114	788,000
Consumer and other [Member]
Loans, Recorded Investment [Line Items]
Loans	6,363	8,355
Pass [Member]
Loans, Recorded Investment [Line Items]
Loans	1,477,792	1,375,227
Pass [Member] | Commercial [Member]
Loans, Recorded Investment [Line Items]
Loans	344,586	329,366
Pass [Member] | Construction, land and land development [Member]
Loans, Recorded Investment [Line Items]
Loans	206,719	204,572
Pass [Member] | 1-4 family residential first mortgages [Member]
Loans, Recorded Investment [Line Items]
Loans	49,905	46,278
Pass [Member] | Home Equity Loan [Member]
Loans, Recorded Investment [Line Items]
Loans	13,466	17,646
Pass [Member] | Commercial real estate [Member]
Loans, Recorded Investment [Line Items]
Loans	856,789	769,010
Pass [Member] | Consumer and other [Member]
Loans, Recorded Investment [Line Items]
Loans	6,327	8,355
Watch [Member]
Loans, Recorded Investment [Line Items]
Loans	23,187	22,493
Watch [Member] | Commercial [Member]
Loans, Recorded Investment [Line Items]
Loans	901	3,303
Watch [Member] | Construction, land and land development [Member]
Loans, Recorded Investment [Line Items]
Loans	732	0
Watch [Member] | 1-4 family residential first mortgages [Member]
Loans, Recorded Investment [Line Items]
Loans	890	798
Watch [Member] | Home Equity Loan [Member]
Loans, Recorded Investment [Line Items]
Loans	54	0
Watch [Member] | Commercial real estate [Member]
Loans, Recorded Investment [Line Items]
Loans	20,574	18,392
Watch [Member] | Consumer and other [Member]
Loans, Recorded Investment [Line Items]
Loans	36	0
Substandard [Member]
Loans, Recorded Investment [Line Items]
Loans	11,286	3,500
Substandard [Member] | Commercial [Member]
Loans, Recorded Investment [Line Items]
Loans	1,995	1,345
Substandard [Member] | Construction, land and land development [Member]
Loans, Recorded Investment [Line Items]
Loans	0	1,038
Substandard [Member] | 1-4 family residential first mortgages [Member]
Loans, Recorded Investment [Line Items]
Loans	249	108
Substandard [Member] | Home Equity Loan [Member]
Loans, Recorded Investment [Line Items]
Loans	291	411
Substandard [Member] | Commercial real estate [Member]
Loans, Recorded Investment [Line Items]
Loans	8,751	598
Substandard [Member] | Consumer and other [Member]
Loans, Recorded Investment [Line Items]
Loans	0	0
Doubtful [Member]
Loans, Recorded Investment [Line Items]
Loans	0	0
Doubtful [Member] | Commercial [Member]
Loans, Recorded Investment [Line Items]
Loans	0	0
Doubtful [Member] | Construction, land and land development [Member]
Loans, Recorded Investment [Line Items]
Loans	0	0
Doubtful [Member] | 1-4 family residential first mortgages [Member]
Loans, Recorded Investment [Line Items]
Loans	0	0
Doubtful [Member] | Home Equity Loan [Member]
Loans, Recorded Investment [Line Items]
Loans	0	0
Doubtful [Member] | Commercial real estate [Member]
Loans, Recorded Investment [Line Items]
Loans	0	0
Doubtful [Member] | Consumer and other [Member]
Loans, Recorded Investment [Line Items]
Loans	$ 0	$ 0

Loans and Allowance for Loan 69

Loans and Allowance for Loan Losses Schedule of Allowance for Loan Loss Activity (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, beginning balance				$ 16,112				$ 14,967	$ 16,112	$ 14,967	$ 13,607
Charge-offs									(375)	(406)	(439)
Recoveries									693	551	949
Provision for loan losses	$ 0	$ 0	$ 0	0	$ 100	$ 200	$ 500	200	0	1,000	850
Allowance for loan losses, ending balance	16,430				16,112				16,430	16,112	14,967
Commercial [Member]
Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, beginning balance				3,881				4,369	3,881	4,369	4,415
Charge-offs									(199)	(125)	(408)
Recoveries									232	218	579
Provision for loan losses									(48)	(581)	(217)
Allowance for loan losses, ending balance	3,866				3,881				3,866	3,881	4,369
Construction, land and land development [Member]
Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, beginning balance				2,639				2,338	2,639	2,338	2,151
Charge-offs									0	(141)	0
Recoveries									398	217	250
Provision for loan losses									(824)	225	(63)
Allowance for loan losses, ending balance	2,213				2,639				2,213	2,639	2,338
1-4 family residential first mortgages [Member]
Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, beginning balance				317				508	317	508	466
Charge-offs									0	(93)	(23)
Recoveries									15	59	7
Provision for loan losses									(13)	(157)	58
Allowance for loan losses, ending balance	319				317				319	317	508
Home equity [Member]
Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, beginning balance				478				481	478	481	534
Charge-offs									(176)	0	(2)
Recoveries									28	36	87
Provision for loan losses									(144)	(39)	(138)
Allowance for loan losses, ending balance	186				478				186	478	481
Commercial real estate [Member]
Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, beginning balance				8,697				7,254	8,697	7,254	6,013
Charge-offs									0	0	0
Recoveries									13	13	12
Provision for loan losses									1,060	1,430	1,229
Allowance for loan losses, ending balance	9,770				8,697				9,770	8,697	7,254
Consumer and other [Member]
Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, beginning balance				$ 100				$ 17	100	17	28
Charge-offs									0	(47)	(6)
Recoveries									7	8	14
Provision for loan losses									(31)	122	(19)
Allowance for loan losses, ending balance	$ 76				$ 100				$ 76	$ 100	$ 17

Loans and Allowance for Loan 70

Loans and Allowance for Loan Losses Schedule of Allowance for Loan Losses Based on Impairment Method (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loans, Allowance for Credit Losses [Line Items]
Allowance for loan losses, individually evaluated for impairment	$ 139	$ 503
Allowance for loan losses, collectively evaluated for impairment	16,291	15,609
Allowance for loan losses	16,430	16,112
Commercial [Member]
Loans, Allowance for Credit Losses [Line Items]
Allowance for loan losses, individually evaluated for impairment	0	91
Allowance for loan losses, collectively evaluated for impairment	3,866	3,790
Allowance for loan losses	3,866	3,881
Construction, land and land development [Member]
Loans, Allowance for Credit Losses [Line Items]
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	2,213	2,639
Allowance for loan losses	2,213	2,639
1-4 family residential first mortgages [Member]
Loans, Allowance for Credit Losses [Line Items]
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	319	317
Allowance for loan losses	319	317
Home equity [Member]
Loans, Allowance for Credit Losses [Line Items]
Allowance for loan losses, individually evaluated for impairment	21	276
Allowance for loan losses, collectively evaluated for impairment	165	202
Allowance for loan losses	186	478
Commercial real estate [Member]
Loans, Allowance for Credit Losses [Line Items]
Allowance for loan losses, individually evaluated for impairment	118	136
Allowance for loan losses, collectively evaluated for impairment	9,652	8,561
Allowance for loan losses	9,770	8,697
Consumer and other [Member]
Loans, Allowance for Credit Losses [Line Items]
Allowance for loan losses, individually evaluated for impairment	0	0
Allowance for loan losses, collectively evaluated for impairment	76	100
Allowance for loan losses	$ 76	$ 100

Loans and Allowance for Loan 71

Loans and Allowance for Loan Losses Schedule of Loans by Impairment Method (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loans, Allowance for Credit Losses [Line Items]
Loans, individually evaluated for impairment	$ 622	$ 1,022
Loans, collectively evaluated for impairment	1,511,643	1,400,198
Loans	1,512,265	1,401,220
Commercial [Member]
Loans, Allowance for Credit Losses [Line Items]
Loans, individually evaluated for impairment	0	126
Loans, collectively evaluated for impairment	347,482	333,888
Loans	347,482	334,014
Construction, land and land development [Member]
Loans, Allowance for Credit Losses [Line Items]
Loans, individually evaluated for impairment	0	0
Loans, collectively evaluated for impairment	207,451	205,610
Loans	207,451	205,610
1-4 family residential first mortgages [Member]
Loans, Allowance for Credit Losses [Line Items]
Loans, individually evaluated for impairment	91	108
Loans, collectively evaluated for impairment	50,953	47,076
Loans	51,044	47,184
Home equity [Member]
Loans, Allowance for Credit Losses [Line Items]
Loans, individually evaluated for impairment	193	317
Loans, collectively evaluated for impairment	13,618	17,740
Loans	13,811	18,057
Commercial real estate [Member]
Loans, Allowance for Credit Losses [Line Items]
Loans, individually evaluated for impairment	338	471
Loans, collectively evaluated for impairment	885,776	787,529
Loans	886,114	788,000
Consumer and other [Member]
Loans, Allowance for Credit Losses [Line Items]
Loans, individually evaluated for impairment	0	0
Loans, collectively evaluated for impairment	6,363	8,355
Loans	$ 6,363	$ 8,355

Premises and Equipment, Net (De

Premises and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Premises and equipment [Line Items]
Premises and equipment, gross	$ 30,572	$ 30,147
Accumulated depreciation	(7,550)	(6,833)
Premises and equipment, net	23,022	23,314
Land [Member]
Premises and equipment [Line Items]
Premises and equipment, gross	4,323	4,323
Buildings [Member]
Premises and equipment [Line Items]
Premises and equipment, gross	14,423	14,344
Leasehold improvements [Member]
Premises and equipment [Line Items]
Premises and equipment, gross	3,880	3,843
Furniture and equipment [Member]
Premises and equipment [Line Items]
Premises and equipment, gross	$ 7,946	$ 7,637

Deposits Deposits (Details)

Deposits Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deposits [Abstract]
Time deposit maturities, 2018	$ 133,323
Time deposit maturities, 2019	18,698
Time deposit maturities, 2020	8,451
Time deposit maturities, 2021	3,396
Time deposit maturities, 2022	5,789
Time deposits, total	169,657
CDARS deposits	100,091	$ 53,821
ICS Checking Deposits	117,990	83,089
ICS Money Market Deposits	$ 213,587	$ 155,957

Subordinated Notes (Details)

Subordinated Notes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Jul. 18, 2003
Debt Instrument [Line Items]
Subordinated notes, gross	$ 20,412,000	$ 20,398,000
Subordinated debt [Member]
Debt Instrument [Line Items]
Subordinated notes, gross			$ 20,619,000
Deferral period option, junior subordinated debentures	5 years
Dividends allowed, deferral of subordinated debt	$ 0
Term of security maturity	30 years
Debt instrument, variable interest rate period end	4.74%
Debt instrument, interest rate, effective percentage	4.81%
Debt instrument, unamortized discount and debt issuance costs	$ 207,000	221,000
Debt instrument, frequency of periodic payment	quarterly
Three-month LIBOR [Member] | Subordinated debt [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis	3-month LIBOR
Debt instrument, basis spread on variable rate	3.05%
Designated as hedging instrument [Member] | Interest rate swap due September 30, 2026 [Member] | Cash flow hedging [Member]
Debt Instrument [Line Items]
Derivative, notional amount	$ 20,000,000	$ 20,000,000

Federal Home Loan Bank Advanc75

Federal Home Loan Bank Advances, Maturities Summary (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Bank Advances Maturities Summary [Line Items]
Federal Home Loan Bank advances	$ 80,000	$ 105,000
Discount for modification	(3,618)	(5,114)
Federal Home Loan Bank advances, net	76,382	99,886
Maturity date January 29, 2018 [Member]
Federal Home Loan Bank Advances Maturities Summary [Line Items]
Federal Home Loan Bank advances	$ 0	$ 25,000
Debt instrument, fixed rate period end	0.00%	2.70%
Debt instrument, interest rate, effective percentage	0.00%	2.70%
Maturity date December 23, 2019 [Member]
Federal Home Loan Bank Advances Maturities Summary [Line Items]
Federal Home Loan Bank advances	$ 25,000	$ 25,000
Debt instrument, variable interest rate period end	1.93%	1.28%
Debt instrument, interest rate, effective percentage	3.90%	3.26%
Maturity date June 22, 2020 [Member]
Federal Home Loan Bank Advances Maturities Summary [Line Items]
Federal Home Loan Bank advances	$ 25,000	$ 25,000
Debt instrument, variable interest rate period end	1.95%	1.30%
Debt instrument, interest rate, effective percentage	4.09%	3.45%
Maturity date September 21, 2020 [Member]
Federal Home Loan Bank Advances Maturities Summary [Line Items]
Federal Home Loan Bank advances	$ 30,000	$ 30,000
Debt instrument, variable interest rate period end	1.95%	1.30%
Debt instrument, interest rate, effective percentage	4.44%	4.44%

Federal Home Loan Bank Advanc76

Federal Home Loan Bank Advances (Other Narratives) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 21, 2012
Line of Credit Facility [Line Items]
Federal Home Loan Bank Advances, modified				$ 80,000,000
Debt instrument, unamortized prepayment discount, gross				$ 11,152,000
Amortization of debt prepayment discount	$ 1,496,000	$ 1,501,000	$ 1,497,000
Federal Home Loan Bank advances	80,000,000	105,000,000
Additional borrowing capacity, Federal Home Loan Bank advances	384,000,000
Federal funds lines of credit at correspondent banks [Member]
Line of Credit Facility [Line Items]
Amount outstanding, line of credit	0
Federal funds lines of credit at correspondent banks [Member] | Unsecured debt [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity, line of credit	67,000,000
Maturity date September 21, 2020 [Member]
Line of Credit Facility [Line Items]
Federal Home Loan Bank advances	30,000,000	30,000,000
Cash flow hedging [Member] | Designated as hedging instrument [Member] | Interest rate swap due September 21 2020 [Member]
Line of Credit Facility [Line Items]
Derivative, notional amount	$ 30,000,000	$ 30,000,000

Long-term debt (Details)

Long-term debt (Details) - USD ($)	May 25, 2017	Jun. 30, 2013	Dec. 31, 2017	Dec. 31, 2016
Secured debt [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 25,000,000
Debt Instrument, Term	5 years
Debt instrument, gross			$ 22,500,000	$ 4,600,000
Debt instrument, Quarterly Payment, Principal	$ 625,000
Secured debt [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.95%
Debt instrument, description of variable rate basis	30-day LIBOR
Debt instrument, interest rate, effective percentage			3.33%
Contract Payable [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 765,000
Debt instrument, interest rate, stated percentage		1.25%
Debt Instrument, Term		9 years
Debt instrument, gross			$ 417,000	$ 529,000

Long-term debt Maturities of lo

Long-term debt Maturities of long-term debt (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Long-term Debt, Unclassified [Abstract]
Long-term debt, maturities, repayments of principal in next twelve months	$ 2,614
Long-term debt, maturities, repayments of principal in year two	2,615
Long-term debt, maturities, repayments of principal in year three	2,616
Long-term debt, maturities, repayments of principal in year four	2,537
Long-term debt, maturities, repayments of principal in year five	12,535
Long-term debt, net	$ 22,917	$ 5,126

Derivatives (Details)

Derivatives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest rate swap due September 21 2020 [Member]
Derivatives, Fair Value [Line Items]
Cash pledged as collateral		$ 210	$ 470
Interest rate swap due September 30, 2026 [Member] | Counterparties [Member]
Derivatives, Fair Value [Line Items]
Cash pledged as collateral		980	1,070
Cash flow hedging [Member] | Interest rate swap due September 21 2020 [Member] | Designated as hedging instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, notional amount		$ 30,000	$ 30,000
Derivative, weighted average receive rate		1.95%	1.30%
Derivative, weighted average pay rate		2.52%	2.52%
Cash flow hedging [Member] | Interest rate swap due September 21 2020 [Member] | Designated as hedging instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Interest rate cash flow hedge liability at fair value		$ (86)	$ (496)
Cash flow hedging [Member] | Interest rate swap due September 30, 2026 [Member] | Designated as hedging instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, notional amount		$ 20,000	$ 20,000
Derivative, weighted average receive rate		0.00%	0.00%
Derivative, weighted average pay rate		4.81%	4.81%
Cash flow hedging [Member] | Interest rate swap due September 30, 2026 [Member] | Designated as hedging instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Interest rate cash flow hedge asset at fair value		$ 895	$ 1,068
Cash flow hedging [Member] | Terminated interest rate swap [Member]
Derivatives, Fair Value [Line Items]
Derivative termination fee paid		541
Cash flow hedging [Member] | Terminated interest rate swap [Member] | Designated as hedging instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, notional amount		$ 70,000
Scenario, forecast [Member] | Cash flow hedging [Member] | Interest rate swap due September 21 2020 [Member] | Designated as hedging instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative instruments, gain (loss) reclassification from accumulated OCI to income, estimated net amount to be transferred	$ 278

Derivatives Pre-Tax Losses (Det

Derivatives Pre-Tax Losses (Details) - Designated as hedging instrument [Member] - Interest rate swap [Member] - Cash flow hedging [Member] - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Other income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on cash flow hedge ineffectiveness, net	$ 0	$ 0	$ 0
Effective portion [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on interest rate cash flow hedges, pretax, accumulated other comprehensive income (loss)	(1,144)	(66)	882
Effective portion [Member] | Interest expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified from accumulated oci into income, effective portion, net	$ (160)	$ (413)	$ (573)

Income Taxes Schedule of Compon

Income Taxes Schedule of Components of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Current federal income tax expense									$ 8,822	$ 8,220	$ 8,057
Current state income tax expense									1,713	1,627	1,558
Deferred federal income tax expense									2,527	115	112
Deferred state income tax expense									306	(26)	(30)
Income tax expense	$ 5,226	$ 2,870	$ 2,872	$ 2,400	$ 2,687	$ 2,634	$ 2,381	$ 2,234	$ 13,368	$ 9,936	$ 9,697

Income Taxes Schedule of Effect

Income Taxes Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income tax reconciliation, income tax expense, at federal statutory income tax rate, amount									$ 12,753	$ 11,533	$ 11,004
Effective income tax rate reconciliation, at federal statutory income tax rate, percent									35.00%	35.00%	35.00%
Income tax reconciliation, state income taxes, amount									$ 1,146	$ 1,004	$ 957
Effective income tax rate reconciliation, state income taxes, percent									3.20%	3.00%	3.00%
Income tax reconciliation, tax exempt interest income, amount									$ (2,023)	$ (1,823)	$ (1,786)
Effective income rate tax reconciliation, tax exempt interest income, percent									(5.60%)	(5.50%)	(5.70%)
Income tax reconciliation, nondeductible interest expense to own tax-exempts, amount									$ 152	$ 58	$ 43
Effective income tax rate reconciliation, nondeductible interest expense to own tax-exempts, percent									0.40%	0.20%	0.10%
Income tax reconciliation, tax-exempt increase in cash value of life insurance and gains, amount									$ (336)	$ (381)	$ (254)
Effective income tax rate reconciliation, tax-exempt increase in cash value of life insurance and gains, percent									(0.90%)	(1.20%)	(0.80%)
Income tax reconciliation, share based compensation excess tax benefit, amount									$ (261)	$ 0	$ 0
Effective income tax reconciliation, share based compensation excess tax benefit, percent									(0.70%)	(0.00%)	(0.00%)
Income tax reconciliation, change in enacted tax rate, amount									$ 2,340	$ 0	$ 0
Effective income tax rate reconciliation,change in enacted rate, percent									6.40%	0.00%	0.00%
Income tax reconciliation, capital loss carryforward, amount									$ 0	$ 0	$ (130)
Effective income tax rate reconciliation capital loss carryforward, percent									(0.00%)	(0.00%)	(0.40%)
Income tax reconciliation, federal income tax credits, amount									$ (410)	$ (405)	$ (275)
Effective income tax rate reconciliation, federal income tax credits, percent									(1.10%)	(1.20%)	(0.90%)
Income tax reconciliation, other adjustments, amount									$ 7	$ (50)	$ 138
Effective income tax rate reconciliation, other adjustments, percent									0.00%	(0.10%)	0.50%
Income tax expense	$ 5,226	$ 2,870	$ 2,872	$ 2,400	$ 2,687	$ 2,634	$ 2,381	$ 2,234	$ 13,368	$ 9,936	$ 9,697
Effective income tax rate									36.70%	30.20%	30.80%

Income Taxes Schedule of Deferr

Income Taxes Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Deferred tax assets, allowance for loan losses	$ 4,108	$ 6,123
Deferred tax assets, unrealized losses on securities available for sale	902	719
Deferred tax assets, intangible assets	101	462
Deferred tax assets, accrued expenses	176	706
Deferred tax assets, restricted stock unit compensation	544	446
Deferred tax assets, state net operating loss carryforward	1,379	1,271
Deferred tax assets, other	86	190
Deferred tax assets, gross	7,296	9,917
Deferred tax liabilities, deferred loan costs	193	321
Deferred tax liabilities, net unrealized gains on interest rate swaps	139	80
Deferred tax liabilities, premises and equipment	792	1,027
Deferred tax liabilities, other	148	261
Deferred tax liabilities, gross	1,272	1,689
Deferred tax assets, net, before valuation allowance	6,024	8,228
Valuation allowance	(1,379)	(1,271)
Deferred tax assets, net	$ 4,645	$ 6,957

Income Taxes Schedule of Operat

Income Taxes Schedule of Operating Loss Carryforwards (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Operating Loss Carryforwards [Line Items]
State net operating loss carryforwards	$ 22,989
Minimum [Member]
Operating Loss Carryforwards [Line Items]
State net operating loss carryforwards, expiration dates	Dec. 31, 2019

Income Taxes Schedule of Penalt

Income Taxes Schedule of Penalties and Interest (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income tax interest and penalties included in accrued tax expense	$ 0	$ 0
Income tax interest and penalties recognized	$ 0	$ 0	$ 0

Stock Compensation Plans Restri

Stock Compensation Plans Restricted Stock Unit Activity (Details) - Restricted stock units (RSUs) [Member] - Common stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Stock compensation plan, restricted stock, outstanding beginning of period (number of shares)	307,268	261,833	179,699
Stock compensation plan, restricted stock, grants in period (number of shares)	138,500	141,000	139,500
Stock compensation plan, restricted stock, vested in period (number of shares)	(106,468)	(95,565)	(57,366)
Stock compensation plan, restricted stock, forfeited in period (number of shares)	0	0	0
Stock compensation plan, restricted stock, outstanding end of period (number of shares)	339,300	307,268	261,833
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Stock compensation plan, restricted stock, outstanding beginning of period, weighted average grant date fair value ($ per share)	$ 17.46	$ 16.67	$ 13.39
Stock compensation plan, restricted stock, grants in period, weighted average grant date fair value ($ per share)	22.06	18.44	19.59
Stock compensation plan, restricted stock, vested in period, weighted average grant date fair value ($ per share)	16.79	16.74	13.23
Stock compensation plan, restricted stock, forfeitures, weighted average grant date fair value ($ per share)	0	0	0
Stock compensation plan, restricted stock, outstanding end of period, weighted average grand date fair value ($ per share)	$ 19.55	$ 17.46	$ 16.67

Stock Compensation Plans Narrat

Stock Compensation Plans Narratives (Details) - Common stock [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted stock units (RSUs) [Member]
Stock compensation plan [Line Items]
Stock compensation plan, restricted stock, outstanding, weighted average remaining contractual terms	1 year 6 months
Restricted stock or unit expense	$ 0
Shares of common stock per restricted stock unit	1
Stock compensation plan, restricted stock, vested in period, fair value	$ 2,371	$ 1,730	$ 1,118
Stock compensation expense	2,632	1,684	1,166
Stock compensation plan, tax benefit from compensation expense	285	$ 105	$ 155
Stock compensation plan, restricted stock, nonvested awards, compensation not yet recognized	$ 3,788
West Bancorporation, Inc. 2017 Equity Incentive Plan [Member]
Stock compensation plan [Line Items]
Stock compensation plan, restricted stock, number of shares authorized	800,000
Stock compensation plan, restricted stock, number of shares available for grant	776,000

Employee Savings and Stock Ow88

Employee Savings and Stock Ownership Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Contribution Plan Disclosure [Line Items]
Expense, defined contribution plan, employer contributions	$ 961	$ 1,023	$ 960
Defined contribution plan, employer discretionary contribution percent	4.00%	4.00%	4.00%
Shares held in employee stock ownership plan, allocated	294,423	327,307
One Hundred Percent Matching Percentage [Member]
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent	6.00%	6.00%	6.00%

Changes in Accumulated Other Co

Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), balance beg of period	$ (1,042)
Total other comprehensive loss	(850)	$ (612)	$ (684)
Accumulated other comprehensive income (loss), balance end of period	(1,892)	(1,042)
Accumulated Other Comprehensive Income (Loss) [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), balance beg of period	(1,042)	(430)	254
Other comprehensive income (loss), before reclassifications, net of tax	(738)	(847)	(730)
Amounts reclassified from accumulated other comprehensive income, current period, net of tax	(112)	235	46
Total other comprehensive loss	(850)	(612)	(684)
Accumulated other comprehensive income (loss), balance end of period	(1,892)	(1,042)	(430)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), balance beg of period	(1,172)	342	416
Other comprehensive income (loss), before reclassifications, net of tax	(697)	(1,394)	(21)
Amounts reclassified from accumulated other comprehensive income, current period, net of tax	(368)	(120)	(53)
Total other comprehensive loss	(1,065)	(1,514)	(74)
Accumulated other comprehensive income (loss), balance end of period	(2,237)	(1,172)	342
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), balance beg of period	130	(772)	(162)
Other comprehensive income (loss), before reclassifications, net of tax	(41)	547	(709)
Amounts reclassified from accumulated other comprehensive income, current period, net of tax	256	355	99
Total other comprehensive loss	215	902	(610)
Accumulated other comprehensive income (loss), balance end of period	$ 345	$ 130	$ (772)

Regulatory Capital Requiremen90

Regulatory Capital Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital	$ 216,420	$ 202,530
Capital to risk weighted assets	11.76%	11.87%
Capital required for capital adequacy	$ 147,169	$ 136,448
Capital required for capital adequacy to risk weighted assets	8.00%	8.00%
Capital Required for Capital Adequacy With Capital Conservation Buffer	$ 170,164	$ 147,108
Capital Required For Capital Adequacy With Capital Conservation Buffer To Risk Weighted Assets	9.25%	8.625%
Tier one risk based capital	$ 199,990	$ 186,418
Tier one risk based capital to risk weighted assets	10.87%	10.93%
Tier one risk based capital required for capital adequacy	$ 110,377	$ 102,336
Tier one risk based capital required for capital adequacy to risk weighted assets	6.00%	6.00%
Tier One Risk Based Capital Required For Capital Adequacy With Capital Conservation Buffer	$ 133,372	$ 112,996
Tier One Risk Based Capital Required For Capital Adequacy With Capital Conservation Buffer To Risk Weighted Assets	7.25%	6.625%
Common Equity Tier One Capital	$ 179,990	$ 166,418
Common equity tier one capital to risk weighted assets	9.78%	9.76%
Common Equity Tier One Capital Required for Capital Adequacy	$ 82,783	$ 76,752
Common equity tier one capital required for capital adequacy to risk weighted assets	4.50%	4.50%
Common Equity Tier One Capital Required For Capital Adequacy with Capital Conservation Buffer	$ 105,778	$ 87,412
Common Equity Tier One Capital Required For Capital Adequacy With Capital Conservation Buffer To Risk Weighted Assets	5.75%	5.125%
Tier one leverage capital	$ 199,990	$ 186,418
Tier one leverage capital to average assets	9.60%	10.14%
Tier one leverage capital required for capital adequacy	$ 83,326	$ 73,530
Tier one leverage capital required for capital adequacy to average assets	4.00%	4.00%
Tier one leverage capital required for capital adequacy with capital conservation buffer	$ 83,326	$ 73,530
Tier one leverage capital required for capital adequacy with capital conservation buffer to average assets	4.00%	4.00%
Tangible capital to tangible assets	8.42%	8.92%
Intangible assets	$ 0	$ 0
West Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital	$ 235,570	$ 186,118
Capital to risk weighted assets	12.82%	11.04%
Capital required for capital adequacy	$ 147,049	$ 134,877
Capital required for capital adequacy to risk weighted assets	8.00%	8.00%
Capital Required for Capital Adequacy With Capital Conservation Buffer	$ 170,026	$ 145,414
Capital Required For Capital Adequacy With Capital Conservation Buffer To Risk Weighted Assets	9.25%	8.625%
Capital required to be well capitalized	$ 183,812	$ 168,597
Capital required to be well capitalized to risk weighted assets	10.00%	10.00%
Tier one risk based capital	$ 219,140	$ 170,006
Tier one risk based capital to risk weighted assets	11.92%	10.08%
Tier one risk based capital required for capital adequacy	$ 110,287	$ 101,158
Tier one risk based capital required for capital adequacy to risk weighted assets	6.00%	6.00%
Tier One Risk Based Capital Required For Capital Adequacy With Capital Conservation Buffer	$ 133,263	$ 111,695
Tier One Risk Based Capital Required For Capital Adequacy With Capital Conservation Buffer To Risk Weighted Assets	7.25%	6.625%
Tier one risk based capital required to be well capitalized	$ 147,049	$ 134,877
Tier one risk based capital required to be well capitalized to risk weighted assets	8.00%	8.00%
Common Equity Tier One Capital	$ 219,140	$ 170,006
Common equity tier one capital to risk weighted assets	11.92%	10.08%
Common Equity Tier One Capital Required for Capital Adequacy	$ 82,715	$ 75,868
Common equity tier one capital required for capital adequacy to risk weighted assets	4.50%	4.50%
Common Equity Tier One Capital Required For Capital Adequacy with Capital Conservation Buffer	$ 105,692	$ 86,406
Common Equity Tier One Capital Required For Capital Adequacy With Capital Conservation Buffer To Risk Weighted Assets	5.75%	5.125%
Common Equity Tier One Capital Required to be Well-Capitalized	$ 119,478	$ 109,588
Common equity tier one capital required to be well capitalized to risk weighted assets	6.50%	6.50%
Tier one leverage capital	$ 219,140	$ 170,006
Tier one leverage capital to average assets	10.52%	9.34%
Tier one leverage capital required for capital adequacy	$ 83,287	$ 72,807
Tier one leverage capital required for capital adequacy to average assets	4.00%	4.00%
Tier one leverage capital required for capital adequacy with capital conservation buffer	$ 83,287	$ 72,807
Tier one leverage capital required for capital adequacy with capital conservation buffer to average assets	4.00%	4.00%
Tier one leverage capital required to be well capitalized	$ 104,109	$ 91,009
Tier one leverage capital required to be well capitalized to average assets	5.00%	5.00%

Commitments and Contingencies R

Commitments and Contingencies Rent Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Leases, Operating [Abstract]
Operating leases, rent expense	$ 1,344	$ 1,293	$ 1,741

Commitments and Contingencies M

Commitments and Contingencies Minimum Rental Commitments (Details) $ in Thousands	Dec. 31, 2017USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating leases, future estimated minimum payments due, 2018	$ 1,509
Operating leases, future estimated minimum payments due, 2019	1,547
Operating leases, future estimated minimum payments due, 2020	1,547
Operating leases, future estimated minimum payments due, 2021	1,493
Operating leases, future estimated minimum payments due, 2022	1,462
Operating leases, future estimated minimum payments due, thereafter	5,341
Operating leases, total future estimated minimum payments due	$ 12,899

Commitments and Contingencies93

Commitments and Contingencies Required Reserve Balances (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Subsidiaries [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Required cash reserve balances, Federal Reserve Bank	$ 6,086	$ 6,393

Commitments and Contingencies C

Commitments and Contingencies Commitments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan commitments	$ 623,945	$ 620,168
Commitments to extend credit [Member]
Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan commitments	617,949	614,681
Commitments to extend credit [Member] | Commitments to extend credit, expiration after [Member]
Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan commitments	99,105
Standby letters of credit [Member]
Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan commitments	$ 5,996	$ 5,487

Commitments and Contingencies O

Commitments and Contingencies Other Narratives (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loss Contingencies [Line Items]
Present value of credit enhancement fees	$ 96
FHLB MPF program remaining outstanding balance of loans sold	94,292	$ 112,084
Standby letters of credit [Member]
Loss Contingencies [Line Items]
Guarantor obligations, current carrying value	$ 0	$ 0

Commitments and Contingencies96

Commitments and Contingencies Contractual commitments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Affordable Housing Project Investment [Member]
Long-term Purchase Commitment [Line Items]
Contractual obligation	$ 6,130	$ 5,768

Fair Value Measurements Recurri

Fair Value Measurements Recurring Basis by Level (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	$ 444,219	$ 260,637
Fair value, inputs, level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Interest rate swaps, derivative asset	895	1,068
Interest rate swaps, derivative liability	86	496
Fair value, measurements, recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Interest rate swaps, derivative asset	895	1,068
Interest rate swaps, derivative liability	86	496
Fair value, measurements, recurring [Member] | Fair value, inputs, level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Interest rate swaps, derivative asset	0	0
Interest rate swaps, derivative liability	0	0
Fair value, measurements, recurring [Member] | Fair value, inputs, level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Interest rate swaps, derivative asset	895	1,068
Interest rate swaps, derivative liability	86	496
Fair value, measurements, recurring [Member] | Fair value, inputs, level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Interest rate swaps, derivative asset	0	0
Interest rate swaps, derivative liability	0	0
U.S. government agencies and corporations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale		2,593
U.S. government agencies and corporations [Member] | Fair value, measurements, recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale		2,593
U.S. government agencies and corporations [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale		0
U.S. government agencies and corporations [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale		2,593
U.S. government agencies and corporations [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale		0
State and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	146,313	64,336
State and political subdivisions [Member] | Fair value, measurements, recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	146,313	64,336
State and political subdivisions [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	0	0
State and political subdivisions [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	146,313	64,336
State and political subdivisions [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	0	0
Collateralized mortgage obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	159,932	101,950
Collateralized mortgage obligations [Member] | Fair value, measurements, recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	159,932	101,950
Collateralized mortgage obligations [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	0	0
Collateralized mortgage obligations [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	159,932	101,950
Collateralized mortgage obligations [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	0	0
Mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	60,429	80,158
Mortgage-backed securities [Member] | Fair value, measurements, recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	60,429	80,158
Mortgage-backed securities [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	0	0
Mortgage-backed securities [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	60,429	80,158
Mortgage-backed securities [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	0	0
Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	45,195
Asset-backed Securities [Member] | Fair value, measurements, recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	45,195
Asset-backed Securities [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	0
Asset-backed Securities [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	45,195
Asset-backed Securities [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	0
Trust preferred security [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	2,006	1,250
Trust preferred security [Member] | Fair value, measurements, recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	2,006	1,250
Trust preferred security [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	0	0
Trust preferred security [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	2,006	1,250
Trust preferred security [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	0	0
Corporate notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	30,344	10,350
Corporate notes [Member] | Fair value, measurements, recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	30,344	10,350
Corporate notes [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	0	10,050
Corporate notes [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	30,344	300
Corporate notes [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investment securities available for sale	$ 0	$ 0

Fair Value Measurements Nonrecu

Fair Value Measurements Nonrecurring Basis by Level (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, measurements, nonrecurring [Member] | Fair value, inputs, level 3 [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	$ 0	$ 0

Fair Value Measurements Carryin

Fair Value Measurements Carrying Amounts and Fair Values (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	$ 34,952	$ 40,943
Federal funds sold	12,997	35,893
Investment securities available for sale	444,219	260,637
Investment securities held to maturity	45,527	48,386
Federal Home Loan Bank stock	9,174	10,771
Loans, net	1,494,070	1,383,758
Accrued interest receivable	7,344	5,321
Deposits	1,810,813	1,546,605
Federal funds purchased	545	9,690
Federal Home Loan Bank advances	80,000	105,000
Long-term debt, net	22,917	5,126
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	444,219	260,637
Fair value, inputs, level 1 [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	34,952	40,943
Federal funds sold	12,997	35,893
Federal Home Loan Bank stock	9,174	10,771
Accrued interest receivable	7,344	5,321
Federal funds purchased	545	9,690
Accrued interest payable	736	280
Fair value, inputs, level 1 [Member] | Estimate of fair value, fair value disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	34,952	40,943
Federal funds sold	12,997	35,893
Federal Home Loan Bank stock	9,174	10,771
Accrued interest receivable	7,344	5,321
Federal funds purchased	545	9,690
Accrued interest payable	736	280
Fair value, inputs, level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps, derivative asset	895	1,068
Interest rate swaps, derivative liability	86	496
Fair value, inputs, level 2 [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities held to maturity	45,527	48,386
Loans, net	1,494,070	1,383,758
Interest rate swaps, derivative asset	895	1,068
Deposits	1,810,813	1,546,605
Subordinated notes, net	20,412	20,398
Federal Home Loan Bank advances	76,382	99,886
Long-term debt, net	22,917	5,126
Interest rate swaps, derivative liability	86	496
Fair value, inputs, level 2 [Member] | Estimate of fair value, fair value disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities held to maturity	45,890	47,789
Loans, net	1,490,166	1,382,569
Deposits	1,810,924	1,546,307
Subordinated notes, net	15,357	12,703
Federal Home Loan Bank advances	76,382	99,959
Long-term debt, net	22,860	5,054
Standby letters of credit [Member] | Fair value, inputs, level 3 [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Standby letters of credit	0	0
Standby letters of credit [Member] | Fair value, inputs, level 3 [Member] | Estimate of fair value, fair value disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Standby letters of credit	0	0
Commitments to extend credit [Member] | Fair value, inputs, level 3 [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Standby letters of credit	0	0
Commitments to extend credit [Member] | Fair value, inputs, level 3 [Member] | Estimate of fair value, fair value disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Standby letters of credit	$ 0	$ 0

Fair Value Measurements Narrati

Fair Value Measurements Narratives (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Federal Home Loan Bank Stock Carrying and Redemption Price Per Share	$ 100
Fair value, measurements, recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Transfers between levels, fair value disclosure	$ 0	$ 0

Condensed Balance Sheets - Pare

Condensed Balance Sheets - Parent Company Only (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Premises, net	$ 23,022	$ 23,314
Other assets	4,809	5,113
Total assets	2,114,377	1,854,204
LIABILITIES
Accrued expenses and other liabilities	5,210	7,123
Long-term debt, net	22,917	5,126
Total liabilities	1,936,279	1,688,828
STOCKHOLDERS’ EQUITY
Preferred stock	0	0
Common stock	3,000	3,000
Additional paid-in capital	23,463	21,462
Retained earnings	153,527	141,956
Accumulated other comprehensive income (loss)	(1,892)	(1,042)
Total stockholders’ equity	178,098	165,376	$ 152,377	$ 140,175
Total liabilities and stockholders’ equity	2,114,377	1,854,204
Parent Company [Member]
ASSETS
Cash	3,226	3,945	$ 13,775	$ 8,792
Investment in West Bank	216,693	168,302
Investment in West Bancorporation Capital Trust I	619	619
Premises, net	0	18,194
Other assets	1,034	1,256
Total assets	221,572	192,316
LIABILITIES
Accrued expenses and other liabilities	562	1,416
Subordinated notes, net	20,412	20,398
Long-term debt, net	22,500	5,126
Total liabilities	43,474	26,940
STOCKHOLDERS’ EQUITY
Preferred stock	0	0
Common stock	3,000	3,000
Additional paid-in capital	23,463	21,462
Retained earnings	153,527	141,956
Accumulated other comprehensive income (loss)	(1,892)	(1,042)
Total stockholders’ equity	178,098	165,376
Total liabilities and stockholders’ equity	$ 221,572	$ 192,316

Condensed Statements of Income-

Condensed Statements of Income- Parent Company Only (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Expenses [Abstract]
Interest on subordinated notes									$ 901	$ 728	$ 705
Interest on long-term debt									519	145	232
Occupancy									4,406	4,033	4,105
Income tax benefits	$ 5,226	$ 2,870	$ 2,872	$ 2,400	$ 2,687	$ 2,634	$ 2,381	$ 2,234	13,368	9,936	9,697
Net income	$ 4,194	$ 6,405	$ 6,365	$ 6,106	$ 6,031	$ 5,813	$ 5,476	$ 5,696	23,070	23,016	21,742
Parent Company [Member]
Operating Income
Equity in net income of West Bank									23,933	23,544	22,546
Equity in net income of West Bancorporation Capital Trust I									27	23	21
Intercompany rental income									333	503	207
Other rental income									21	50	43
Total operating income									24,314	24,120	22,817
Operating Expenses [Abstract]
Interest on subordinated notes									901	728	705
Interest on long-term debt									517	145	232
Occupancy									187	280	170
Other expenses									602	443	496
Total operating expenses									2,207	1,596	1,603
Income before income taxes									22,107	22,524	21,214
Income tax benefits									(963)	(492)	(528)
Net income									$ 23,070	$ 23,016	$ 21,742

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows - Parent Company Only (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities:
Net income	$ 4,194	$ 6,405	$ 6,365	$ 6,106	$ 6,031	$ 5,813	$ 5,476	$ 5,696	$ 23,070	$ 23,016	$ 21,742
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation									1,347	1,046	921
Deferred income tax (benefits)									2,833	89	82
Change in assets and liabilities:
(Increase) decrease in other assets									131	(85)	2,951
Increase (decrease) in accrued expenses and other liabilities									(1,503)	1,047	(196)
Cash Flows from Investing Activities:
Purchases of premises									(1,055)	(12,802)	(2,502)
Proceeds from sales of other real estate owned									0	0	2,227
Proceeds from settlement of other assets									0	0	3,593
Proceeds from long-term debt									22,000	0	0
Cash Flows from Financing Activities:
Principal payments on long-term debt									(4,212)	(3,286)	(4,261)
Common stock cash dividends									(11,499)	(10,800)	(9,952)
Parent Company [Member]
Cash Flows from Operating Activities:
Net income									23,070	23,016	21,742
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in net income of West Bank									(23,933)	(23,544)	(22,546)
Equity in net income of West Bancorporation Capital Trust I									(27)	(23)	(21)
Dividends received from West Bank									16,800	14,400	13,900
Dividends received from West Bancorporation Capital Trust I									27	23	21
Amortization									17	20	23
Depreciation									178	244	139
Deferred income tax (benefits)									(240)	97	99
Change in assets and liabilities:
(Increase) decrease in other assets									50	(79)	1,436
Increase (decrease) in accrued expenses and other liabilities									(549)	641	(31)
Net cash provided by operating activities									15,393	14,795	14,762
Cash Flows from Investing Activities:
Proceeds from sales of premises									18,032	0	0
Purchases of premises									(16)	(10,539)	(1,386)
Proceeds from sales of other real estate owned									0	0	2,227
Proceeds from settlement of other assets									0	0	3,593
Capital contribution to West Bank									(40,000)	0	0
Net cash provided by (used in) investing activities									(21,984)	(10,539)	4,434
Proceeds from long-term debt									22,000	0	0
Cash Flows from Financing Activities:
Principal payments on long-term debt									(4,629)	(3,286)	(4,261)
Common stock cash dividends									(11,499)	(10,800)	(9,952)
Net cash provided by (used in) financing activities									5,872	(14,086)	(14,213)
Net increase (decrease) in cash									(719)	(9,830)	4,983
Cash:
Beginning				$ 3,945				$ 13,775	3,945	13,775	8,792
Ending	$ 3,226				$ 3,945				$ 3,226	$ 3,945	$ 13,775

Selected Quarterly Financial104

Selected Quarterly Financial Data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Selected Quarterly Financial Information [Abstract]
Interest income	$ 19,517	$ 18,560	$ 18,166	$ 16,791	$ 16,565	$ 16,696	$ 16,209	$ 15,524	$ 73,034	$ 64,994	$ 60,147
Interest expense	3,973	3,529	3,073	2,402	2,140	1,975	1,936	1,825	12,977	7,876	5,993
Net interest income	15,544	15,031	15,093	14,389	14,425	14,721	14,273	13,699	60,057	57,118	54,154
Provision for loan losses	0	0	0	0	100	200	500	200	0	1,000	850
Net interest income after provision for loan losses	15,544	15,031	15,093	14,389	14,325	14,521	13,773	13,499	60,057	56,118	53,304
Noninterest income	1,908	2,264	2,316	2,160	1,930	1,919	1,903	2,230	8,648	7,982	8,203
Noninterest expense	8,032	8,020	8,172	8,043	7,537	7,993	7,819	7,799	32,267	31,148	30,068
Income before income taxes	9,420	9,275	9,237	8,506	8,718	8,447	7,857	7,930	36,438	32,952	31,439
Income taxes	5,226	2,870	2,872	2,400	2,687	2,634	2,381	2,234	13,368	9,936	9,697
Net income	$ 4,194	$ 6,405	$ 6,365	$ 6,106	$ 6,031	$ 5,813	$ 5,476	$ 5,696	$ 23,070	$ 23,016	$ 21,742
Basic earnings per common share	$ 0.26	$ 0.40	$ 0.39	$ 0.38	$ 0.37	$ 0.36	$ 0.34	$ 0.35	$ 1.42	$ 1.43	$ 1.35
Diluted earnings per common share	$ 0.26	$ 0.39	$ 0.39	$ 0.37	$ 0.37	$ 0.36	$ 0.34	$ 0.35	$ 1.41	$ 1.42	$ 1.35