Community Trust Bancorp (CTBI) 10-K 28 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	COMMUNITY TRUST BANCORP INC /KY/
Entity Central Index Key	350,852
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 735.9
Entity Common Stock, Shares Outstanding		17,710,852
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Cash and due from banks	$ 47,528	$ 48,603
Interest bearing deposits	127,746	95,586
Federal funds sold	0	527
Cash and cash equivalents	175,274	144,716
Certificates of deposit in other banks	9,800	980
Securities available-for-sale at fair value (amortized cost of $590,199 and $608,939, respectively)	585,761	605,394
Securities held-to-maturity at amortized cost (fair value of $660 and $867, respectively)	659	866
Loans held for sale	1,033	1,244
Loans	3,122,940	2,938,371
Allowance for loan and lease losses	(36,151)	(35,933)
Net loans	3,086,789	2,902,438
Premises and equipment, net	46,318	47,940
Federal Home Loan Bank stock	17,927	17,927
Federal Reserve Bank stock	4,887	4,887
Goodwill	65,490	65,490
Core deposit intangible (net of accumulated amortization of $8,616 and $8,483, respectively)	0	133
Bank owned life insurance	65,354	63,881
Mortgage servicing rights	3,484	3,433
Other real estate owned	31,996	35,856
Other assets	41,459	36,984
Total assets	4,136,231	3,932,169
Deposits:
Noninterest bearing	790,930	767,918
Interest bearing	2,472,933	2,313,390
Total deposits	3,263,863	3,081,308
Repurchase agreements	243,814	251,065
Federal funds purchased	7,312	4,816
Advances from Federal Home Loan Bank	845	944
Long-term debt	59,341	61,341
Deferred taxes	4,434	7,836
Other liabilities	25,923	24,244
Total liabilities	3,605,532	3,431,554
Commitments and contingencies (notes 18 and 20)
Shareholders' equity:
Preferred stock, 300,000 shares authorized and unissued	0	0
Common stock, $5 par value, shares authorized 25,000,000; shares outstanding 2017 - 17,692,912; 2016 - 17,628,695	88,465	88,144
Capital surplus	221,472	219,697
Retained earnings	224,268	195,078
Accumulated other comprehensive loss, net of tax	(3,506)	(2,304)
Total shareholders' equity	530,699	500,615
Total liabilities and shareholders' equity	$ 4,136,231	$ 3,932,169

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Securities available-for-sale at amortized cost	$ 590,199	$ 608,939
Securities held-to-maturity at fair value	660	867
Core deposit intangible, accumulated amortization	$ 8,616	$ 8,483
Shareholders' equity:
Preferred stock, shares authorized (in shares)	300,000	300,000
Common stock, par value (in dollars per share)	$ 5	$ 5
Common stock, shares authorized (in shares)	25,000,000	25,000,000
Common stock, shares outstanding (in shares)	17,692,912	17,628,695

Consolidated Statements of Inco

Consolidated Statements of Income and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income:
Interest and fees on loans, including loans held for sale	$ 141,497	$ 133,965	$ 130,829
Interest and dividends on securities:
Taxable	8,715	8,265	9,153
Tax exempt	3,011	2,718	2,705
Interest and dividends on Federal Reserve Bank and Federal Home Loan Bank stock	1,189	1,011	1,010
Other, including interest on federal funds sold	1,284	617	323
Total interest income	155,696	146,576	144,020
Interest expense:
Interest on deposits	14,350	10,921	9,616
Interest on repurchase agreements	1,832	1,155	938
Interest on advances from Federal Home Loan Bank	427	62	49
Interest on long-term debt	1,685	1,417	1,170
Total interest expense	18,294	13,555	11,773
Net interest income	137,402	133,021	132,247
Provision for loan losses	7,521	7,872	8,650
Net interest income after provision for loan losses	129,881	125,149	123,597
Noninterest income:
Service charges on deposit accounts	25,121	24,966	24,282
Gains on sales of loans, net	1,320	1,831	1,978
Trust and wealth management income	10,453	9,585	9,286
Loan related fees	3,678	4,107	3,821
Bank owned life insurance	2,172	2,199	2,158
Brokerage revenue	1,324	1,314	1,426
Securities gains (losses)	73	522	(106)
Other noninterest income	4,367	3,917	3,964
Total noninterest income	48,508	48,441	46,809
Noninterest expense:
Officer salaries and employee benefits	11,823	12,198	11,652
Other salaries and employee benefits	47,006	44,877	42,911
Occupancy, net	8,072	7,999	7,826
Equipment	3,049	2,950	3,049
Data processing	7,100	6,497	6,743
Bank franchise tax	5,478	5,671	5,174
Legal fees	1,668	1,906	2,236
Professional fees	1,991	1,890	1,884
Advertising and marketing	2,721	2,614	2,428
FDIC insurance	1,239	1,789	2,382
Other real estate owned provision and expense	4,500	2,879	3,533
Repossession expense	911	1,156	1,265
Amortization of limited partnership investments	2,419	2,623	2,580
Other noninterest expense	11,901	12,077	11,780
Total noninterest expense	109,878	107,126	105,443
Income before income taxes	68,511	66,464	64,963
Income taxes	17,018	19,118	18,531
Net income	51,493	47,346	46,432
Unrealized holding losses on securities available-for-sale:
Unrealized holding losses arising during the period	(820)	(4,578)	(342)
Less: Reclassification adjustments for realized gains (losses) included in net income	73	522	(106)
Tax benefit	(312)	(1,785)	(83)
Unrealized holding loss on securities available-for-sale, net of tax	(581)	(3,315)	(153)
Implementation of ASU 2018-02	(621)	0	0
Other comprehensive loss, net of tax	(1,202)	(3,315)	(153)
Comprehensive income	$ 50,291	$ 44,031	$ 46,279
Basic earnings per share (in dollars per share)	$ 2.92	$ 2.70	$ 2.66
Diluted earnings per share (in dollars per share)	$ 2.92	$ 2.70	$ 2.66
Weighted average shares outstanding-basic (in shares)	17,631	17,548	17,431
Weighted average shares outstanding-diluted (in shares)	17,653	17,566	17,483
Dividends declared per share (in dollars per share)	$ 1.30	$ 1.26	$ 1.22

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), Net of Tax [Member]	Total
Balance at Dec. 31, 2014	$ 87,332	$ 214,684	$ 144,697	$ 1,164	$ 447,877
Balance (in shares) at Dec. 31, 2014	17,466,375
Increase (Decrease) in Stockholders' Equity [Roll forward]
Net income			46,432		46,432
Unrealized holding loss on securities available-for-sale, net of tax					(153)
Other comprehensive loss, net of tax				(153)	(153)
Cash dividends declared			(21,274)		(21,274)
Issuance of common stock	$ 564	1,518			2,082
Issuance of common stock (in shares)	112,837
Repurchase of common stock	$ (29)	(160)			(189)
Repurchase of common stock (in shares)	(5,724)
Vesting of restricted stock	$ (232)	232			0
Vesting of restricted stock (in shares)	(46,482)
Issuance of restricted stock	$ 53	(53)			0
Issuance of restricted stock (in shares)	10,582
Forfeiture of restricted stock	$ (3)	3			0
Forfeiture of restricted stock (in shares)	(674)
Stock-based compensation		808			808
Balance at Dec. 31, 2015	$ 87,685	217,032	169,855	1,011	475,583
Balance (in shares) at Dec. 31, 2015	17,536,914
Increase (Decrease) in Stockholders' Equity [Roll forward]
Net income			47,346		47,346
Unrealized holding loss on securities available-for-sale, net of tax					(3,315)
Other comprehensive loss, net of tax				(3,315)	(3,315)
Cash dividends declared			(22,123)		(22,123)
Issuance of common stock	$ 693	2,292			2,985
Issuance of common stock (in shares)	138,605
Repurchase of common stock	$ (57)	(325)			(382)
Repurchase of common stock (in shares)	(11,574)
Vesting of restricted stock	$ (265)	265			0
Vesting of restricted stock (in shares)	(52,963)
Issuance of restricted stock	$ 90	(90)			0
Issuance of restricted stock (in shares)	18,069
Forfeiture of restricted stock	$ (2)	2			0
Forfeiture of restricted stock (in shares)	(356)
Stock-based compensation		521			521
Balance at Dec. 31, 2016	$ 88,144	219,697	195,078	(2,304)	$ 500,615
Balance (in shares) at Dec. 31, 2016	17,628,695				17,628,695
Increase (Decrease) in Stockholders' Equity [Roll forward]
Net income			51,493		$ 51,493
Unrealized holding loss on securities available-for-sale, net of tax				(581)	(581)
Other comprehensive loss, net of tax					(1,202)
Cash dividends declared			(22,924)		(22,924)
Issuance of common stock	$ 276	1,237			1,513
Issuance of common stock (in shares)	55,191
Vesting of restricted stock	$ (60)	60			0
Vesting of restricted stock (in shares)	(11,965)
Issuance of restricted stock	$ 118	(118)			0
Issuance of restricted stock (in shares)	23,668
Forfeiture of restricted stock	$ (13)	13			0
Forfeiture of restricted stock (in shares)	(2,677)
Stock-based compensation		583			583
Implementation of ASU 2018-02			621	(621)	0
Balance at Dec. 31, 2017	$ 88,465	$ 221,472	$ 224,268	$ (3,506)	$ 530,699
Balance (in shares) at Dec. 31, 2017	17,692,912				17,692,912

Consolidated Statements of Cha6

Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Increase (Decrease) in Stockholders' Equity [Roll forward]
Other comprehensive income (loss), tax	$ (312)	$ (1,785)	$ (83)
Cash dividends declared (in dollars per share)	$ 1.30	$ 1.26	$ 1.22

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	$ 51,493	$ 47,346	$ 46,432
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	4,007	3,904	3,932
Deferred taxes	(3,090)	701	115
Stock-based compensation	636	458	783
Excess tax benefits of stock-based compensation	0	100	104
Provision for loan losses	7,521	7,872	8,650
Write-downs of other real estate owned and other repossessed assets	3,034	1,214	1,656
Gains on sale of loans held for sale	(1,320)	(1,831)	(1,978)
Securities (gains) losses	(73)	(522)	106
Gain on debt repurchase	(560)	0	0
Gains (losses) on sale of assets, net	40	46	(321)
Proceeds from sale of mortgage loans held for sale	59,400	81,441	80,571
Funding of mortgage loans held for sale	(57,869)	(79,682)	(77,501)
Amortization of securities premiums and discounts, net	3,437	2,452	3,098
Change in cash surrender value of bank owned life insurance	(1,473)	(1,546)	(1,638)
Mortgage servicing rights:
Fair value adjustments	361	324	289
New servicing assets created	(412)	(521)	(557)
Changes in:
Other assets	(4,412)	(3,205)	(6,274)
Other liabilities	1,631	2,874	(2,488)
Net cash provided by operating activities	62,351	61,425	54,979
Certificates of deposit in other banks:
Purchase of certificates of deposit	(11,760)	0	0
Maturity of certificates of deposit	2,940	2,852	4,365
Securities available-for-sale (AFS):
Purchase of AFS securities	(231,680)	(176,236)	(81,456)
Proceeds from sales of AFS securities	87,472	54,446	44,198
Proceeds from prepayments, calls, and maturities of AFS securities	159,584	104,302	79,068
Securities held-to-maturity (HTM):
Proceeds from prepayments and maturities of HTM securities	207	795	1
Change in loans, net	(194,548)	(74,379)	(161,702)
Purchase of premises and equipment	(2,400)	(3,498)	(2,246)
Proceeds from sale and retirement of premises and equipment	25	10	239
Additional investment in Federal Reserve Bank stock	0	0	(18)
Proceeds from sale of other real estate owned and repossessed assets	3,574	5,601	9,287
Additional investment in other real estate owned and repossessed assets	0	0	(85)
Net cash used in investing activities	(186,586)	(86,107)	(108,349)
Cash flows from financing activities:
Change in deposits, net	182,555	100,526	106,525
Change in repurchase agreements and federal funds purchased, net	(4,755)	1,060	8,594
Advances from Federal Home Loan Bank	350,000	50,000	170,000
Payments on advances from Federal Home Loan Bank	(350,099)	(150,112)	(130,114)
Repurchase of long-term debt	(1,440)	0	0
Issuance of common stock	1,513	2,985	2,082
Repurchase of common stock	0	(382)	(189)
Excess tax benefits of stock-based compensation	0	(100)	(104)
Dividends paid	(22,981)	(22,190)	(21,330)
Net cash provided by (used in) financing activities	154,793	(18,213)	135,464
Net increase (decrease) in cash and cash equivalents	30,558	(42,895)	82,094
Cash and cash equivalents at beginning of year	144,716	187,611	105,517
Cash and cash equivalents at end of year	175,274	144,716	187,611
Supplemental disclosures:
Income taxes paid	21,400	19,244	20,527
Interest paid	17,266	13,426	11,609
Non-cash activities:
Loans to facilitate the sale of other real estate owned and repossessed assets	2,679	3,964	4,343
Common stock dividends accrued, paid in subsequent quarter	205	209	239
Real estate acquired in settlement of loans	$ 5,235	$ 5,900	$ 18,557

Accounting Policies

Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Accounting Policies	1. Accounting Policies Basis of Presentation Nature of Operations Use of Estimates The accompanying financial statements have been prepared using values and information currently available to CTBI. Given the volatility of current economic conditions, the values of assets and liabilities recorded in the financial statements could change rapidly, resulting in material future adjustments in asset values, the allowance for loan and lease losses, and capital. Cash and Cash Equivalents Certificates of Deposit in Other Banks Investments Investment Securities a. Trading securities . . b. Available-for-sale securities. Investments not classified as trading securities (nor as held-to-maturity securities) shall be classified as available-for-sale securities. We do not have any securities that are classified as trading securities. Available-for-sale securities are reported at fair value, with unrealized gains and losses included as a separate component of shareholders’ equity, net of tax. If declines in fair value are other than temporary, the carrying value of the securities is written down to fair value as a realized loss with a charge to income for the portion attributable to credit losses and a charge to other comprehensive income for the portion that is not credit related. Gains or losses on disposition of securities are computed by specific identification for all securities except for shares in mutual funds, which are computed by average cost. Interest and dividend income, adjusted by amortization of purchase premium or discount, is included in earnings. When the fair value of a security is below its amortized cost, and depending on the length of time the condition exists and the extent the fair market value is below amortized cost, additional analysis is performed to determine whether an other than temporary impairment condition exists. Available-for-sale and held-to-maturity securities are analyzed quarterly for possible other than temporary impairment. The analysis considers (i) whether we have the intent to sell our securities prior to recovery and/or maturity and (ii) whether it is more likely than not that we will not have to sell our securities prior to recovery and/or maturity. Often, the information available to conduct these assessments is limited and rapidly changing, making estimates of fair value subject to judgment. If actual information or conditions are different than estimated, the extent of the impairment of the security may be different than previously estimated, which could have a material effect on the CTBI’s results of operations and financial condition. Loans A restructuring of a debt constitutes a troubled debt restructuring if the creditor for economic or legal reasons related to the debtor’s financial difficulties grants a concession to the debtor that it would not otherwise consider. Loan origination and commitment fees and certain direct loan origination costs are deferred and the net amount amortized over the estimated life of the related loans, leases, or commitments as a yield adjustment. Allowance for Loan and Lease Losses We utilize an internal risk grading system for commercial credits. Those larger commercial credits that exhibit probable or observed credit weaknesses are subject to individual review. The borrower’s cash flow, adequacy of collateral coverage, and other options available to CTBI, including legal remedies, are evaluated. The review of individual loans includes those loans that are impaired as defined by ASC 310-10-35, Impairment of a Loan A loan is considered impaired when, based on current information and events, it is probable that CTBI will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. Impairment is measured on a loan-by-loan basis for commercial and construction loans by either the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s obtainable market price, or the fair value of the collateral if the loan is collateral dependent. Homogenous loans, such as consumer installment, residential mortgages, and home equity lines are not individually risk graded. The associated ALLL for these loans is measured under ASC 450, Contingencies When any secured commercial loan is considered uncollectable, whether past due or not, a current assessment of the value of the underlying collateral is made. If the balance of the loan exceeds the fair value of the collateral, the loan is placed on nonaccrual and the loan is charged down to the value of the collateral less estimated cost to sell or a specific reserve equal to the difference between book value of the loan and the fair value assigned to the collateral is created until such time as the loan is foreclosed. When the foreclosed collateral has been legally assigned to CTBI, the estimated fair value of the collateral less costs to sell is then transferred to other real estate owned or other repossessed assets, and a charge-off is taken for any remaining balance. When any unsecured commercial loan is considered uncollectable the loan is charged off no later than at 90 days past due. All closed-end consumer loans (excluding conventional 1-4 family residential loans and installment and revolving loans secured by real estate) are charged off no later than 120 days (5 monthly payments) delinquent. If a loan is considered uncollectable, it is charged off earlier than 120 days delinquent. For conventional 1-4 family residential loans and installment and revolving loans secured by real estate, when a loan is 90 days past due, a current assessment of the value of the real estate is made. If the balance of the loan exceeds the fair value of the property, the loan is placed on nonaccrual. Foreclosure proceedings are normally initiated after 120 days. When the foreclosed property has been legally assigned to CTBI, the fair value less estimated costs to sell is transferred to other real estate owned and the remaining balance is taken as a charge-off. Historical loss rates for loans are adjusted for significant factors that, in management’s judgment, reflect the impact of any current conditions on loss recognition. We use twelve rolling quarters for our historical loss rate analysis. Factors that we consider include delinquency trends, current economic conditions and trends, strength of supervision and administration of the loan portfolio, levels of underperforming loans, level of recoveries to prior year’s charge-offs, trends in loan losses, industry concentrations and their relative strengths, amount of unsecured loans, and underwriting exceptions. Management continually reevaluates the other subjective factors included in its ALLL analysis. Loans Held for Sale Premises and Equipment Depreciation and amortization are computed primarily using the straight-line method. Estimated useful lives range up to 40 years for buildings, 2 to 10 years for furniture, fixtures, and equipment, and up to the lease term for leasehold improvements. Capitalized leased assets are amortized on a straight-line basis over the lives of the respective leases. Federal Home Loan Bank and Federal Reserve Stock CTB is also a member of its regional Federal Reserve Bank. Federal Reserve Bank stock is carried at cost, classified as a restricted security, and periodically evaluated for impairment based on the ultimate recovery par value. Both cash and stock dividends are reported as income. Other Real Estate Owned All revenues and expenses related to the carrying of other real estate owned are recognized through the income statement. Goodwill and Core Deposit Intangible Intangibles-Goodwill and Other The balance of goodwill, at $65.5 million, has not changed since January 1, 2015. The activity to core deposit intangible for the years ended December 31, 2017, 2016, and 2015 is shown below. (in thousands) 2017 2016 2015 Beginning balance, January 1 $ 133 $ 291 $ 477 Amortization (133 ) (158 ) (186 ) Ending balance, December 31 $ 0 $ 133 $ 291 Our core deposit intangible has been fully amortized as of December 31, 2017. Transfers of Financial Assets Income Taxes Earnings Per Share (“EPS”) Diluted EPS adjusts the number of weighted average shares of common stock outstanding by the dilutive effect of stock options, including restricted shares, as prescribed in ASC 718, Share-Based Payment Segments Bank Owned Life Insurance Mortgage Servicing Rights Servicing Assets and Liabilities Fair Value Measurements Share-Based Compensation Share-Based Payment Comprehensive Income Transfers between Fair Value Hierarchy Levels – Reclassifications – New Accounting Standards Ø Financial Instruments – Overall Financial Instruments – Overall (Subtopic 825-10) Ø Leases – In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) . We have calculated the minimum and maximum net present value of all potential lease payments to be between $10.1 million and $20.3 million. The next step in the analysis will be to determine the renewal periods reasonably expected to be exercised. Ø Investments—Equity Method and Joint Ventures: Simplifying the Transition to the Equity Method of Accounting FASB issued ASU No. 2016-07, Investments - Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting. The amendments affect all entities that have an investment that becomes qualified for the equity method of accounting as a result of an increase in the level of ownership interest or degree of influence. The amendments eliminate the requirement that when an investment qualifies for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investment, results of operations, and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods that the investment had been held. The amendments require that the equity method investor add the cost of acquiring the additional interest in the investee to the current basis of the investor’s previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. Therefore, upon qualifying for the equity method of accounting, no retroactive adjustment of the investment is required. The amendments require that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in accumulated other comprehensive income at the date the investment becomes qualified for use of the equity method. The amendments should be applied prospectively upon their effective date to increases in the level of ownership interest or degree of influence that result in the adoption of the equity method. The amendments became effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016 and did not . Ø Compensation—Stock Compensation: Improvements to Employee Share-Based Payment Accounting FASB issued Accounting Standards Update (ASU) No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The amendments are intended to improve the accounting for employee share-based payments and affect all organizations that issue share-based payment awards to their employees. Several aspects of the accounting for share-based payment award transactions are simplified, including: (a) (b) (c) For public companies, the amendments were effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Ø Revenue from Contracts with Customers – Revenue from Contracts with Customers Ø Accounting for Credit Losses Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. For purchased financial assets with a more-than-insignificant amount of credit deterioration since origination (“PCD assets”) that are measured at amortized cost, the initial allowance for credit losses is added to the purchase price rather than being reported as a credit loss expense. Subsequent changes in the allowance for credit losses on PCD assets are recognized through the statement of income as a credit loss expense. Credit losses relating to available-for-sale debt securities will be recorded through an allowance for credit losses rather than as a direct write-down to the security. ASU 2016-13 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. CTBI has an implementation team working through the provisions of ASU 2016-13 including assessing the impact on its accounting and disclosures. The team has established the historical data that will be available and has identified the potential loan segments to be analyzed. Initial data analysis will begin in the first quarter of 2018. Ø Statement of Cash Flows Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. Stakeholders indicated that there is diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows under Topic 230, Statement of Cash Flows, and other Topics. This ASU addresses the following eight specific cash flow issues: Debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies (COLIs) (including bank-owned life insurance policies (BOLIs)); distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. The amendments in this Update apply to all entities that are required to present a statement of cash flows under Topic 230. This Update is the final version of Proposed Accounting Standards Update EITF-15F— Statement of Cash Flows—Classification of Certain Cash Receipts and Cash Payments (Topic 230) , which has been deleted. The amendments in this Update are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The amendments in this Update should be applied using a retrospective transition method to each period presented. If it is impracticable to apply the amendments retrospectively for some of the issues, the amendments for those issues would be applied prospectively as of the earliest date practicable. We adopted this ASU effective January 1, 2018 with no Ø Simplifying the Test for Goodwill Impairment Intangibles – Goodwill and Other (Topic 350) – Simplifying the Test for Goodwill Impairment Ø Receivables – Nonrefundable Fees and Other Costs: Premium Amortization on Purchased Callable Debt Securities Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities Ø Income Statement—Reporting Comprehensive Income Income Statement—Reporting Comprehensive Income (Topic 220)

Cash and Due from Banks and Int

Cash and Due from Banks and Interest Bearing Deposits	12 Months Ended
	Dec. 31, 2017
Cash and Due from Banks and Interest Bearing Deposits [Abstract]
Cash and Due from Banks and Interest Bearing Deposits	2. Cash and Due from Banks and Interest Bearing Deposits Included in cash and due from banks and interest bearing deposits are amounts required to be held at the Federal Reserve or maintained in vault cash in accordance with regulatory reserve requirements. The balance requirements were $73.5 million and $74.1 million at December 31, 2017 and 2016, respectively. At December 31, 2017, CTBI had cash accounts which exceeded federally insured limits, and therefore are not subject to FDIC insurance, with $124.3 million in deposits with the Federal Reserve, $21.3 million in deposits with US Bank, $0.3 million in deposits with Fifth Third Bank, and $3.5 million in deposits with the Federal Home Loan Bank.

Securities

Securities	12 Months Ended
	Dec. 31, 2017
Securities [Abstract]
Securities	3. Securities Securities are classified into held-to-maturity and available-for-sale categories. Held-to-maturity (HTM) securities are those that CTBI has the positive intent and ability to hold to maturity and are reported at amortized cost. Available-for-sale (AFS) securities are those that CTBI may decide to sell if needed for liquidity, asset-liability management or other reasons. Available-for-sale securities are reported at fair value, with unrealized gains or losses included as a separate component of equity, net of tax. The amortized cost and fair value of securities at December 31, 2017 are summarized as follows: Available-for-Sale (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury and government agencies $ 211,574 $ 170 $ (1,172 ) $ 210,572 State and political subdivisions 144,159 2,017 (1,161 ) 145,015 U.S. government sponsored agency mortgage-backed securities 208,959 357 (4,007 ) 205,309 Other debt securities 507 0 0 507 Total debt securities 565,199 2,544 (6,340 ) 561,403 CRA investment funds 25,000 76 (718 ) 24,358 Total available-for-sale securities $ 590,199 $ 2,620 $ (7,058 ) $ 585,761 Held-to-Maturity (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value State and political subdivisions $ 659 $ 1 $ 0 $ 660 Total held-to-maturity securities $ 659 $ 1 $ 0 $ 660 The amortized cost and fair value of securities at December 31, 2016 are summarized as follows: Available-for-Sale (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury and government agencies $ 223,014 $ 193 $ (743 ) $ 222,464 State and political subdivisions 133,351 1,957 (1,792 ) 133,516 U.S. government sponsored agency mortgage-backed securities 227,574 1,008 (3,526 ) 225,056 Other debt securities 0 0 0 0 Total debt securities 583,939 3,158 (6,061 ) 581,036 CRA investment funds 25,000 76 (718 ) 24,358 Total available-for-sale securities $ 608,939 $ 3,234 $ (6,779 ) $ 605,394 Held-to-Maturity (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value State and political subdivisions $ 866 $ 1 $ 0 $ 867 Total held-to-maturity securities $ 866 $ 1 $ 0 $ 867 The amortized cost and fair value of securities at December 31, 2017 by contractual maturity are shown below. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Available-for-Sale Held-to-Maturity (in thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 4,288 $ 4,294 $ 0 $ 0 Due after one through five years 163,320 162,977 659 660 Due after five through ten years 43,595 44,022 0 0 Due after ten years 144,530 144,294 0 0 U.S. government sponsored agency mortgage-backed securities 208,959 205,309 0 0 Other debt securities 507 507 0 0 Total debt securities 565,199 561,403 659 660 CRA investment funds 25,000 24,358 0 0 Total securities $ 590,199 $ 585,761 $ 659 $ 660 In 2017, there was a net gain of $73 thousand realized on sales and calls of AFS securities, consisting of a pre-tax gain of $278 thousand and a pre-tax loss of $205 thousand. There was a net gain of $522 thousand realized in 2016 and a net loss of $106 thousand realized in 2015. The amortized cost of securities pledged as collateral, to secure public deposits and for other purposes, was $225.7 million at December 31, 2017 and $221.2 million at December 31, 2016. The amortized cost of securities sold under agreements to repurchase amounted to $296.4 million at December 31, 2017 and $303.5 million at December 31, 2016. CTBI evaluates its investment portfolio on a quarterly basis for impairment. The analysis performed as of December 31, 2017 indicates that all impairment is considered temporary, market and interest rate driven, and not credit-related. The percentage of total investments with unrealized losses as of December 31, 2017 was 69.5% compared to 65.6% as of December 31, 2016. The following tables provide the amortized cost, gross unrealized losses, and fair market value, aggregated by investment category and length of time the individual securities have been in a continuous unrealized loss position as of December 31, 2017 that are not deemed to be other-than-temporarily impaired. There were no held-to-maturity securities that were deemed to be impaired as of December 31, 2017. Available-for-Sale (in thousands) Amortized Cost Gross Unrealized Losses Fair Value Less Than 12 Months U.S. Treasury and government agencies $ 136,688 $ (840 ) $ 135,848 State and political subdivisions 34,283 (416 ) 33,867 U.S. government sponsored agency mortgage-backed securities 62,768 (643 ) 62,125 Other debt securities 0 0 0 Total debt securities 233,739 (1,899 ) 231,840 CRA investment funds 7,500 (105 ) 7,395 Total <12 months temporarily impaired AFS securities 241,239 (2,004 ) 239,235 12 Months or More U.S. Treasury and government agencies 23,885 (332 ) 23,553 State and political subdivisions 16,930 (745 ) 16,185 U.S. government sponsored agency mortgage-backed securities 117,827 (3,364 ) 114,463 Other debt securities 0 0 0 Total debt securities 158,642 (4,441 ) 154,201 CRA investment funds 15,000 (613 ) 14,387 Total ≥12 months temporarily impaired AFS securities 173,642 (5,054 ) 168,588 Total U.S. Treasury and government agencies 160,573 (1,172 ) 159,401 State and political subdivisions 51,213 (1,161 ) 50,052 U.S. government sponsored agency mortgage-backed securities 180,595 (4,007 ) 176,588 Other debt securities 0 0 0 Total debt securities 392,381 (6,340 ) 386,041 CRA investment funds 22,500 (718 ) 21,782 Total temporarily impaired AFS securities $ 414,881 $ (7,058 ) $ 407,823 The analysis performed as of December 31, 2016 indicated that all impairment was considered temporary, market and interest rate driven, and not credit-related. The following tables provide the amortized cost, gross unrealized losses, and fair market value, aggregated by investment category and length of time the individual securities have been in a continuous unrealized loss position as of December 31, 2016 that are not deemed to be other-than-temporarily impaired. There were no held-to-maturity securities that were deemed to be impaired as of December 31, 2016. Available-for-Sale (in thousands) Amortized Cost Gross Unrealized Losses Fair Value Less Than 12 Months U.S. Treasury and government agencies $ 158,732 $ (716 ) $ 158,016 State and political subdivisions 53,491 (1,780 ) 51,711 U.S. government sponsored agency mortgage-backed securities 135,939 (2,646 ) 133,293 Other debt securities 0 0 0 Total debt securities 348,162 (5,142 ) 343,020 CRA investment funds 17,500 (444 ) 17,056 Total <12 months temporarily impaired AFS securities 365,662 (5,586 ) 360,076 12 Months or More U.S. Treasury and government agencies 1,880 (27 ) 1,853 State and political subdivisions 751 (12 ) 739 U.S. government sponsored agency mortgage-backed securities 31,132 (880 ) 30,252 Other debt securities 0 0 0 Total debt securities 33,763 (919 ) 32,844 CRA investment funds 5,000 (274 ) 4,726 Total ≥12 months temporarily impaired AFS securities 38,763 (1,193 ) 37,570 Total U.S. Treasury and government agencies 160,612 (743 ) 159,869 State and political subdivisions 54,242 (1,792 ) 52,450 U.S. government sponsored agency mortgage-backed securities 167,071 (3,526 ) 163,545 Other debt securities 0 0 0 Total debt securities 381,925 (6,061 ) 375,864 CRA investment funds 22,500 (718 ) 21,782 Total temporarily impaired AFS securities $ 404,425 $ (6,779 ) $ 397,646 U.S. Treasury and Government Agencies The unrealized losses in U.S. Treasury and government agencies were caused by interest rate increases. The contractual terms of those investments do not permit the issuer to settle the securities at a price less than par which will equal amortized cost at maturity. CTBI does not consider those investments to be other-than-temporarily impaired at December 31, 2017, because CTBI does not intend to sell the investments and it is not more likely than not that we will be required to sell the investments before recovery of their amortized cost, which may be maturity. State and Political Subdivisions The unrealized losses in securities of state and political subdivisions were caused by interest rate increases. The contractual terms of those investments do not permit the issuer to settle the securities at a price less than par which will equal amortized cost at maturity. CTBI does not consider those investments to be other-than-temporarily impaired at December 31, 2017, because CTBI does not intend to sell the investments before recovery of their amortized cost and it is not more likely than not that we will be required to sell the investments before recovery of their amortized cost, which may be maturity. U.S. Government Sponsored Agency Mortgage-Backed Securities The unrealized losses in U.S. government sponsored agency mortgage-backed securities were caused by interest rate increases. CTBI expects to recover the amortized cost basis over the term of the securities. CTBI does not consider those investments to be other-than-temporarily impaired at December 31, 2017, because (i) the decline in market value is attributable to changes in interest rates and not credit quality, (ii) CTBI does not intend to sell the investments, and (iii) it is not more likely than not we will be required to sell the investments before recovery of their amortized cost, which may be maturity. CRA Investment Funds CTBI’s CRA investment funds consist of investments in fixed income mutual funds ($24.4 million of the total fair value and $718 thousand of the total unrealized losses in common stock investments). The severity of the impairment (fair value is approximately 2.9% less than cost) and the duration of the impairment correlates with the decline in long-term interest rates in 2017. CTBI evaluated the near-term prospects of these funds in relation to the severity and duration of the impairment. Based on that evaluation, CTBI does not consider those investments to be other-than-temporarily impaired at December 31, 2017.

Loans

Loans	12 Months Ended
	Dec. 31, 2017
Loans [Abstract]
Loans	4. Loans Major classifications of loans, net of unearned income, deferred loan origination costs, and net premiums on acquired loans, are summarized as follows: (in thousands) December 31 2017 December 31 2016 Commercial construction $ 76,479 $ 66,998 Commercial secured by real estate 1,188,680 1,085,428 Equipment lease financing 3,042 5,512 Commercial other 351,034 350,159 Real estate construction 67,358 57,966 Real estate mortgage 709,570 702,969 Home equity 99,356 91,511 Consumer direct 137,754 133,093 Consumer indirect 489,667 444,735 Total loans $ 3,122,940 $ 2,938,371 CTBI has segregated and evaluates its loan portfolio through nine portfolio segments. CTBI serves customers in small and mid-sized communities in eastern, northeastern, central, and south central Kentucky, southern West Virginia, and northeastern Tennessee. Therefore, CTBI’s exposure to credit risk is significantly affected by changes in these communities. Commercial construction loans are for the purpose of erecting or rehabilitating buildings or other structures for commercial purposes, including any infrastructure necessary for development. Included in this category are improved property, land development, and tract development loans. The terms of these loans are generally short-term with permanent financing upon completion. Commercial real estate loans include loans secured by nonfarm, nonresidential properties, 1-4 family/multi-family properties, farmland, and other commercial real estate. These loans are originated based on the borrower’s ability to service the debt and secondarily based on the fair value of the underlying collateral. Equipment lease financing loans are fixed or variable leases for commercial purposes. Commercial other loans consist of commercial check loans, agricultural loans, receivable financing, floorplans, loans to financial institutions, loans for purchasing or carrying securities, and other commercial purpose loans. Commercial loans are underwritten based on the borrower’s ability to service debt from the business’s underlying cash flows. As a general practice, we obtain collateral such as real estate, equipment, or other assets, although such loans may be uncollateralized but guaranteed. Real estate construction loans are typically for owner-occupied properties. The terms of these loans are generally short-term with permanent financing upon completion. Residential real estate loans are a mixture of fixed rate and adjustable rate first and second lien residential mortgage loans. As a policy, CTBI holds adjustable rate loans and sells the majority of its fixed rate first lien mortgage loans into the secondary market. Changes in interest rates or market conditions may impact a borrower’s ability to meet contractual principal and interest payments. Residential real estate loans are secured by real property. Home equity lines are revolving adjustable rate credit lines secured by real property. Consumer direct loans are a mixture of fixed rate and adjustable rate products comprised of unsecured loans, consumer revolving credit lines, deposit secured loans, and all other consumer purpose loans. Consumer indirect loans are fixed rate loans secured by automobiles, trucks, vans, and recreational vehicles originated at the selling dealership underwritten and purchased by CTBI’s indirect lending department. Both new and used products are financed. Only dealers who have executed dealer agreements with CTBI participate in the indirect lending program. Not i Refer to note 1 to the condensed consolidated financial statements for further information regarding our nonaccrual policy. Nonaccrual loans segregated by class of loans were as follows: (in thousands) December 31 2017 December 31 2016 Commercial: Commercial construction $ 1,207 $ 1,912 Commercial secured by real estate 7,028 6,326 Commercial other 934 1,559 Residential: Real estate construction 318 11 Real estate mortgage 8,243 6,260 Home equity 389 555 Total nonaccrual loans $ 18,119 $ 16,623 The following tables present CTBI’s loan portfolio aging analysis, segregated by class, as of December 31, 2017 and 2016: December 31, 2017 (in thousands) 30-59 Days Past Due 60-89 Days Past Due 90+ Days Past Due Total Past Due Current Total Loans 90+ and Accruing* Commercial: Commercial construction $ 138 $ 0 $ 1,238 $ 1,376 $ 75,103 $ 76,479 $ 31 Commercial secured by real estate 4,047 1,599 8,514 14,160 1,174,520 1,188,680 2,665 Equipment lease financing 430 0 0 430 2,612 3,042 0 Commercial other 835 77 652 1,564 349,470 351,034 87 Residential: Real estate construction 224 202 223 649 66,709 67,358 223 Real estate mortgage 2,064 5,029 11,605 18,698 690,872 709,570 6,293 Home equity 595 178 428 1,201 98,155 99,356 167 Consumer: Consumer direct 983 148 62 1,193 136,561 137,754 62 Consumer indirect 4,085 1,399 648 6,132 483,535 489,667 648 Total $ 13,401 $ 8,632 $ 23,370 $ 45,403 $ 3,077,537 $ 3,122,940 $ 10,176 December 31, 2016 (in thousands) 30-59 Days Past Due 60-89 Days Past Due 90+ Days Past Due Total Past Due Current Total Loans 90+ and Accruing* Commercial: Commercial construction $ 22 $ 0 $ 1,940 $ 1,962 $ 65,036 $ 66,998 $ 28 Commercial secured by real estate 2,033 478 8,847 11,358 1,074,070 1,085,428 3,015 Equipment lease financing 0 0 0 0 5,512 5,512 0 Commercial other 997 122 1,235 2,354 347,805 350,159 141 Residential: Real estate construction 707 42 152 901 57,065 57,966 152 Real estate mortgage 1,493 5,278 10,695 17,466 685,503 702,969 6,295 Home equity 829 288 905 2,022 89,489 91,511 467 Consumer: Consumer direct 873 265 68 1,206 131,887 133,093 68 Consumer indirect 3,288 851 681 4,820 439,915 444,735 681 Total $ 10,242 $ 7,324 $ 24,523 $ 42,089 $ 2,896,282 $ 2,938,371 $ 10,847 *90+ and Accruing are also included in 90+ Days Past Due column. The risk characteristics of CTBI’s material portfolio segments are as follows: Commercial construction loans generally are made to customers for the purpose of building income-producing properties. Personal guarantees of the principals are generally required. Such loans are made on a projected cash flow basis and are secured by the project being constructed. Construction loan draw procedures are included in each specific loan agreement, including required documentation items and inspection requirements. Construction loans may convert to term loans at the end of the construction period, or may be repaid by the take-out commitment from another financing source. If the loan is to convert to a term loan, the repayment ability is based on the borrower’s projected cash flow. Risk is mitigated during the construction phase by requiring proper documentation and inspections whenever a draw is requested. Loans in amounts greater than $500,000 generally require a performance bond to be posted by the general contractor to assure completion of the project. Commercial real estate loans are viewed primarily as cash flow loans and secondarily as loans secured by real estate. Commercial real estate lending typically involves higher loan principal amounts and the repayment of these loans is generally dependent on the successful operation of the property securing the loan or the business conducted on the property securing the loan. Commercial real estate loans may be more adversely affected by conditions in the real estate markets or in the general economy. Management monitors and evaluates commercial real estate loans based on collateral and risk grade criteria. Equipment lease financing is underwritten by our commercial lenders using the same underwriting standards as would be applied to a secured commercial loan requesting 100% financing. The pricing for equipment lease financing is comparable to that of borrowers with similar quality commercial credits with similar collateral. Maximum terms of equipment leasing are determined by the type and expected life of the equipment to be leased. Residual values are determined by appraisals or opinion letters from industry experts. Leases must be in conformity with our consolidated annual tax plan. As we underwrite our equipment lease financing in a manner similar to our commercial loan portfolio described below, the risk characteristics for this portfolio mirror that of the commercial loan portfolio. Commercial loans are primarily based on the identified cash flows of the borrower and secondarily on the underlying collateral provided by the borrower. The cash flows of borrowers, however, may not be as expected and the collateral securing these loans may fluctuate in value. Most commercial loans are secured by the assets being financed or other business assets such as accounts receivable or inventory and may incorporate a personal guarantee; however, some short-term loans may be made on an unsecured basis. In the case of loans secured by accounts receivable, the availability of funds for the repayment of these loans may be substantially dependent on the ability of the borrower to collect amounts due from its customers. With respect to residential loans that are secured by 1-4 family residences and are generally owner occupied, CTBI generally establishes a maximum loan-to-value ratio and requires private mortgage insurance if that ratio is exceeded. Home equity loans are typically secured by a subordinate interest in 1-4 family residences. Residential construction loans are handled through the home mortgage area of the bank. The repayment ability of the borrower and the maximum loan-to-value ratio are calculated using the normal mortgage lending criteria. Draws are processed based on percentage of completion stages including normal inspection procedures. Such loans generally convert to term loans after the completion of construction. Consumer loans are secured by consumer assets such as automobiles or recreational vehicles. Some consumer loans are unsecured such as small installment loans and certain lines of credit. Our determination of a borrower’s ability to repay these loans is primarily dependent on the personal income and credit rating of the borrowers, which can be impacted by economic conditions in their market areas such as unemployment levels. Repayment can also be impacted by changes in property values on residential properties. Risk is mitigated by the fact that the loans are of smaller individual amounts and spread over a large number of borrowers. The indirect lending area of the bank generally deals with purchasing/funding consumer contracts with new and used automobile dealers. The dealers generate consumer loan applications which are forwarded to the indirect loan processing area for approval or denial. Loan approvals or denials are based on the creditworthiness and repayment ability of the borrower, and on the collateral value. The dealers may have limited recourse agreements with CTB. Credit Quality Indicators: CTBI categorizes loans into risk categories based on relevant information about the ability of borrowers to service their debt such as: current financial information, historical payment experience, credit documentation, public information, and current economic trends, among other factors. CTBI also considers the fair value of the underlying collateral and the strength and willingness of the guarantor(s). CTBI analyzes commercial loans individually by classifying the loans as to credit risk. Loans classified as loss, doubtful, substandard, or special mention are reviewed quarterly by CTBI for further deterioration or improvement to determine if appropriately classified and valued if deemed impaired. All other commercial loan reviews are completed every 12 to 18 months. In addition, during the renewal process of any loan, as well as if a loan becomes past due or if other information becomes available, CTBI will evaluate the loan grade. CTBI uses the following definitions for risk ratings: Ø Pass Ø Watch Ø Other assets especially mentioned (OAEM) Ø Substandard Ø Doubtful The following tables present the credit risk profile of CTBI’s commercial loan portfolio based on rating category and payment activity, segregated by class of loans, as of December 31, 2017 and 2016: (in thousands) Commercial Construction Commercial Secured by Real Estate Equipment Leases Commercial Other Total December 31, 2017 Pass $ 67,846 $ 1,053,701 $ 3,005 $ 305,655 $ 1,430,207 Watch 3,323 65,182 0 29,008 97,513 OAEM 1,304 22,401 37 3,206 26,948 Substandard 3,828 47,223 0 12,947 63,998 Doubtful 178 173 0 218 569 Total $ 76,479 $ 1,188,680 $ 3,042 $ 351,034 $ 1,619,235 December 31, 2016 Pass $ 55,315 $ 975,383 $ 5,206 $ 299,301 $ 1,335,205 Watch 3,366 51,932 137 32,780 88,215 OAEM 2,535 25,772 169 7,913 36,389 Substandard 5,592 31,945 0 9,599 47,136 Doubtful 190 396 0 566 1,152 Total $ 66,998 $ 1,085,428 $ 5,512 $ 350,159 $ 1,508,097 The following tables present the credit risk profile of CTBI’s residential real estate and consumer loan portfolios based on performing or nonperforming status, segregated by class, as of December 31, 2017 and 2016: (in thousands) Real Estate Construction Real Estate Mortgage Home Equity Consumer Direct Consumer Indirect Total December 31, 2017 Performing $ 66,817 $ 695,034 $ 98,800 $ 137,692 $ 489,019 $ 1,487,362 Nonperforming (1) 541 14,536 556 62 648 16,343 Total $ 67,358 $ 709,570 $ 99,356 $ 137,754 $ 489,667 $ 1,503,705 December 31, 2016 Performing $ 57,803 $ 690,414 $ 90,489 $ 133,025 $ 444,054 $ 1,415,785 Nonperforming (1) 163 12,555 1,022 68 681 14,489 Total $ 57,966 $ 702,969 $ 91,511 $ 133,093 $ 444,735 $ 1,430,274 (1) A loan is considered nonperforming if it is 90 days or more past due or on nonaccrual. The total of consumer mortgage loans secured by real estate properties for which formal foreclosure proceedings are in process totaled $3.7 million at December 31, 2017 compared to $3.5 million at December 31, 2016. A loan is considered impaired, in accordance with the impairment accounting guidance (ASC 310-10-35-16), when based on current information and events, it is probable CTBI will be unable to collect all amounts due from the borrower in accordance with the contractual terms of the loan. Impaired loans include nonperforming commercial loans but also include loans modified in troubled debt restructurings where concessions have been granted to borrowers experiencing financial difficulties. These concessions could include a reduction in the interest rate on the loan, payment extensions, forgiveness of principal, forbearance, or other actions intended to maximize collection. The following table presents impaired loans, the average investment in impaired loans, and interest income recognized on impaired loans for the years ended December 31, 2017, 2016, and 2015: December 31, 2017 (in thousands) Recorded Balance Unpaid Contractual Principal Balance Specific Allowance Average Investment in Impaired Loans *Interest Income Recognized Loans without a specific valuation allowance: Commercial construction $ 4,431 $ 4,439 $ 0 $ 4,835 $ 200 Commercial secured by real estate 28,480 30,365 0 27,753 1,344 Equipment lease financing 0 0 0 34 0 Commercial other 9,481 11,252 0 10,444 539 Real estate construction 318 318 0 534 0 Real estate mortgage 1,564 1,570 0 1,591 36 Loans with a specific valuation allowance: Commercial construction 153 173 25 155 0 Commercial secured by real estate 2,985 4,095 966 3,932 8 Commercial other 0 0 0 65 0 Totals: Commercial construction 4,584 4,612 25 4,990 200 Commercial secured by real estate 31,465 34,460 966 31,685 1,352 Equipment lease financing 0 0 0 34 0 Commercial other 9,481 11,252 0 10,509 539 Real estate construction 318 318 0 534 0 Real estate mortgage 1,564 1,570 0 1,591 36 Total $ 47,412 $ 52,212 $ 991 $ 49,343 $ 2,127 December 31, 2016 (in thousands) Recorded Balance Unpaid Contractual Principal Balance Specific Allowance Average Investment in Impaired Loans *Interest Income Recognized Loans without a specific valuation allowance: Commercial construction $ 4,102 $ 4,123 $ 0 $ 4,367 $ 218 Commercial secured by real estate 29,025 29,594 0 31,136 1,609 Equipment lease financing 0 0 0 0 0 Commercial other 11,215 13,155 0 11,561 632 Real estate mortgage 1,483 1,483 0 1,691 52 Loans with a specific valuation allowance: Commercial construction 1,507 1,509 213 2,290 0 Commercial secured by real estate 4,731 5,885 1,035 4,151 19 Commercial other 139 139 65 483 0 Totals: Commercial construction 5,609 5,632 213 6,657 218 Commercial secured by real estate 33,756 35,479 1,035 35,287 1,628 Equipment lease financing 0 0 0 0 0 Commercial other 11,354 13,294 65 12,044 632 Real estate mortgage 1,483 1,483 0 1,691 52 Total $ 52,202 $ 55,888 $ 1,313 $ 55,679 $ 2,530 December 31, 2015 (in thousands) Recorded Balance Unpaid Contractual Principal Balance Specific Allowance Average Investment in Impaired Loans *Interest Income Recognized Loans without a specific valuation allowance: Commercial construction $ 2,861 $ 2,862 $ 0 $ 4,574 $ 200 Commercial secured by real estate 30,761 32,166 0 30,605 1,378 Equipment lease financing 0 0 0 0 0 Commercial other 7,500 9,148 0 8,802 316 Real estate mortgage 1,744 1,744 0 1,179 50 Loans with a specific valuation allowance: Commercial construction 3,402 3,402 831 3,631 0 Commercial secured by real estate 2,660 2,768 1,227 2,349 7 Commercial other 960 1,153 403 836 1 Totals: Commercial construction 6,263 6,264 831 8,205 200 Commercial secured by real estate 33,421 34,934 1,227 32,954 1,385 Equipment lease financing 0 0 0 0 0 Commercial other 8,460 10,301 403 9,638 317 Real estate mortgage 1,744 1,744 0 1,179 50 Total $ 49,888 $ 53,243 $ 2,461 $ 51,976 $ 1,952 *Cash basis interest is substantially the same as interest income recognized. Included in certain loan categories of impaired loans are certain loans and leases that have been modified in a troubled debt restructuring, where economic concessions have been granted to borrowers who have experienced financial difficulties. These concessions typically result from our loss mitigation activities and could include reductions in the interest rate, payment extensions, forgiveness of principal, forbearance or other actions. Modifications of terms for our loans and their inclusion as troubled debt restructurings are based on individual facts and circumstances. Loan modifications that are included as troubled debt restructurings may involve either an increase or reduction of the interest rate, extension of the term of the loan, or deferral of principal and/or interest payments, regardless of the period of the modification. All of the loans identified as troubled debt restructuring were modified due to financial stress of the borrower. In order to determine if a borrower is experiencing financial difficulty, an evaluation is performed to determine the probability that the borrower will be in payment default on any of its debt in the foreseeable future without the modification. This evaluation is performed under CTBI’s internal underwriting policy. When we modify loans and leases in a troubled debt restructuring, we evaluate any possible impairment similar to other impaired loans based on the present value of expected future cash flows, discounted at the contractual interest rate of the original loan or lease agreement, or use the current fair value of the collateral, less selling costs for collateral dependent loans. If we determined that the value of the modified loan is less than the recorded investment in the loan (net of previous charge-offs, deferred loan fees or costs and unamortized premium or discount), impairment is recognized through an allowance estimate or a charge-off to the allowance. In periods subsequent to modification, we evaluate all troubled debt restructuring, including those that have payment defaults, for possible impairment and recognize impairment through the allowance. During 2017, Year Ended December 31, 2017 (in thousands) Number of Loans Term Modification Rate Modification Combination Post-Modification Outstanding Balance Commercial: Commercial construction 2 $ 0 $ 0 $ 114 $ 114 Commercial secured by real estate 15 2,199 0 192 2,391 Commercial other 22 1,072 0 136 1,208 Residential: Real estate construction 1 846 0 0 846 Real estate mortgage 3 988 0 0 988 Total troubled debt restructurings 43 $ 5,105 $ 0 $ 442 $ 5,547 Year Ended December 31, 2016 (in thousands) Number of Loans Term Modification Rate Modification Combination Post-Modification Outstanding Balance Commercial: Commercial construction 1 $ 1,288 $ 0 $ 0 $ 1,288 Commercial secured by real estate 27 8,827 0 581 9,408 Commercial other 14 5,088 0 87 5,175 Residential: Real estate construction 0 0 0 0 0 Real estate mortgage 1 0 0 281 281 Total troubled debt restructurings 43 $ 15,203 $ 0 $ 949 $ 16,152 No charge-offs have resulted from modifications for any of the presented periods. We had commitments to extend additional credit in the amount of $0.2 million on loans that are considered troubled debt restructurings. Loans retain their accrual status at the time of their modification. As a result, if a loan is on nonaccrual at the time it is modified, it stays as nonaccrual, and if a loan is on accrual at the time of the modification, it generally stays on accrual. Commercial and consumer loans modified in a troubled debt restructuring are closely monitored for delinquency as an early indicator of possible future default. If loans modified in a troubled debt restructuring subsequently default, CTBI evaluates the loan for possible further impairment. The allowance for loan and lease losses may be increased, adjustments may be made in the allocation of the allowance, or partial charge-offs may be taken to further write-down the carrying value of the loan. Presented below, segregated by class of loans, are loans that were modified as troubled debt restructurings within the past twelve months which have subsequently defaulted. CTBI considers a loan in default when it is 90 days or more past due or transferred to nonaccrual. (in thousands) Year Ended December 31, 2017 Number of Loans Recorded Balance Commercial: Commercial secured by real estate 0 $ 0 Commercial other 0 0 Residential: Real estate construction 1 846 Real estate mortgage 0 0 Total defaulted restructured loans 1 $ 846 (in thousands) Year Ended December 31, 2016 Number of Loans Recorded Balance Commercial: Commercial secured by real estate 1 $ 67 Commercial other 1 12 Residential: Real estate construction 0 0 Real estate mortgage 0 0 Total defaulted restructured loans 2 $ 79

Mortgage Banking and Servicing

Mortgage Banking and Servicing Rights	12 Months Ended
	Dec. 31, 2017
Mortgage Banking and Servicing Rights [Abstract]
Mortgage Banking and Servicing Rights	5. Mortgage Banking and Servicing Rights Mortgage banking activities primarily include residential mortgage originations and servicing. As discussed in note 1 above, mortgage servicing rights (“MSRs”) are carried at fair market value. The fair value is determined quarterly based on an independent third-party valuation using a discounted cash flow analysis and calculated using a computer pricing model. The system used in this evaluation, Compass Point, attempts to quantify loan level idiosyncratic risk by calculating a risk derived value. As a result, each loan’s unique characteristics determine the valuation assumptions ascribed to that loan. Additionally, the computer valuation is based on key economic assumptions including the prepayment speeds of the underlying loans generated using the Andrew Davidson Prepayment Model, FHLMC/FNMA guidelines, the weighted average life of the loan, the discount rate, the weighted average coupon, and the weighted-average default rate, as applicable. Along with the gains received from the sale of loans, fees are received for servicing loans. These fees include late fees, which are recorded in interest income, and ancillary fees and monthly servicing fees, which are recorded in noninterest income. Costs of servicing loans are charged to expense as incurred. Changes in fair market value of the MSRs are reported as an increase or decrease to mortgage banking income. The following table presents the components of mortgage banking income: (in thousands) Year Ended December 31 2017 2016 2015 Net gain on sale of mortgage loans held for sale $ 1,232 $ 1,831 $ 1,978 Net loan servicing income (expense) Servicing fees 1,255 1,239 1,197 Late fees 84 78 88 Ancillary fees 239 322 212 Fair value adjustments (361 ) (324 ) (289 ) Net loan servicing income 1,217 1,315 1,208 Mortgage banking income $ 2,449 $ 3,146 $ 3,186 Mortgage loans serviced for others are not included in the accompanying balance sheets. Loans serviced for the benefit of others (primarily FHLMC) totaled $462 million, $466 million, and $458 million at December 31, 2017, 2016, and 2015, respectively. Servicing loans for others generally consists of collecting mortgage payments, maintaining escrow accounts, disbursing payments to investors, and processing foreclosures. Custodial escrow balances maintained in connection with the foregoing loan servicing, and included in demand deposits, were approximately $1.0 million at December 31, 2017, 2016, and 2015, respectively. Activity for capitalized mortgage servicing rights using the fair value method is as follows: (in thousands) 2017 2016 2015 Fair value of MSRs, beginning of period $ 3,433 $ 3,236 $ 2,968 New servicing assets created 412 521 557 Change in fair value during the period due to: Time decay (1) (184 ) (175 ) (168 ) Payoffs (2) (268 ) (313 ) (247 ) Changes in valuation inputs or assumptions (3) 91 164 126 Fair value of MSRs, end of period $ 3,484 $ 3,433 $ 3,236 (1) Represents decrease in value due to regularly scheduled loan principal payments and partial loan paydowns. (2) Represents decrease in value due to loans that paid off during the period. (3) Represents change in value resulting from market-driven changes in interest rates. The fair values of capitalized mortgage servicing rights were $3.5 million, $3.4 million, and $3.2 million at December 31, 2017, 2016, and 2015, respectively. Fair values for the years ended December 31, 2017, 2016, and 2015 were determined by third-party valuations with a resulting 10.1% average discount rate over the last three years, respectively, and weighted average default rates of 3.03%, 3.02%, and 2.64%, respectively. Prepayment speeds generated using the Andrew Davidson Prepayment Model averaged 10.0%, 9.5%, and 10.0% at December 31, 2017, 2016, and 2015, respectively. MSR values are very sensitive to movement in interest rates as expected future net servicing income depends on the projected balance of the underlying loans, which can be greatly impacted by the level of prepayments. CTBI does not currently hedge against changes in the fair value of its MSR portfolio.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	6. Related Party Transactions In the ordinary course of business, CTB has made extensions of credit and had transactions with certain directors and executive officers of CTBI or our subsidiaries, including their associates (as defined by the Securities and Exchange Commission). We believe such extensions of credit and transactions were made on substantially the same terms, including interest rate and collateral, as those prevailing at the same time for comparable transactions with other persons. Activity for related party extensions of credit during 2017 and 2016 is as follows: (in thousands) 2017 2016 Related party extensions of credit, beginning of period $ 27,081 $ 29,224 New loans and advances on lines of credit 522 2,456 Repayments (2,615 ) (4,599 ) Increase (decrease) due to changes in related parties (8,156 ) 0 Related party extensions of credit, end of period $ 16,832 $ 27,081 The aggregate balances of related party deposits at December 31, 2017 and 2016 were $15.8 million and $15.5 million, respectively. A director of CTBI is a shareholder in a law firm that provided services to CTBI and its subsidiaries during the years 2017, 2016, and 2015. Approximately $1.1 million in legal fees and $0.1 million in expenses paid on behalf of CTBI, $1.2 million total, were paid to this law firm during 2017. Approximately $1.0 million in legal fees and $0.1 million in expenses, $1.1 million total, were paid during 2016, and approximately $1.2 million in legal fees and $0.1 million in expenses, $1.3 million in total, were paid during 2015.

Allowance for Loan and Lease Lo

Allowance for Loan and Lease Losses	12 Months Ended
	Dec. 31, 2017
Allowance for Loan and Lease Losses [Abstract]
Allowance for Loan and Lease Losses	7. Allowance for Loan and Lease Losses The following tables present the balance in the allowance for loan and lease losses (“ALLL”) and the recorded investment in loans based on portfolio segment and impairment method as of December 31, 2017, 2016, and 2015: 2017 (in thousands) Commercial Construction Commercial Secured by Real Estate Equipment Lease Financing Commercial Other Real Estate Construction Real Estate Mortgage Home Equity Consumer Direct Consumer Indirect Total ALLL Balance, beginning of year $ 884 $ 14,191 $ 42 $ 4,656 $ 629 $ 6,027 $ 774 $ 1,885 $ 6,845 $ 35,933 Provision charged to expense (237 ) 2,281 (24 ) 1,744 31 189 257 418 2,862 7,521 Losses charged off (10 ) (2,038 ) 0 (1,893 ) 0 (615 ) (178 ) (965 ) (5,386 ) (11,085 ) Recoveries 49 75 0 532 0 87 4 525 2,510 3,782 Balance, end of year $ 686 $ 14,509 $ 18 $ 5,039 $ 660 $ 5,688 $ 857 $ 1,863 $ 6,831 $ 36,151 Ending balance: Individually evaluated for impairment $ 25 $ 966 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 991 Collectively evaluated for impairment $ 661 $ 13,543 $ 18 $ 5,039 $ 660 $ 5,688 $ 857 $ 1,863 $ 6,831 $ 35,160 Loans Ending balance: Individually evaluated for impairment $ 4,584 $ 31,465 $ 0 $ 9,481 $ 318 $ 1,564 $ 0 $ 0 $ 0 $ 47,412 Collectively evaluated for impairment $ 71,895 $ 1,157,215 $ 3,042 $ 341,553 $ 67,040 $ 708,006 $ 99,356 $ 137,754 $ 489,667 $ 3,075,528 2016 (in thousands) Commercial Construction Commercial Secured by Real Estate Equipment Lease Financing Commercial Other Real Estate Construction Real Estate Mortgage Home Equity Consumer Direct Consumer Indirect Total ALLL Balance, beginning of year $ 2,199 $ 14,434 $ 79 $ 4,225 $ 550 $ 6,678 $ 839 $ 1,594 $ 5,496 $ 36,094 Provision charged to expense (1,035 ) 1,220 (37 ) 2,128 264 291 (20 ) 912 4,149 7,872 Losses charged off (316 ) (1,641 ) 0 (2,136 ) (192 ) (1,043 ) (54 ) (1,236 ) (5,050 ) (11,668 ) Recoveries 36 178 0 439 7 101 9 615 2,250 3,635 Balance, end of year $ 884 $ 14,191 $ 42 $ 4,656 $ 629 $ 6,027 $ 774 $ 1,885 $ 6,845 $ 35,933 Ending balance: Individually evaluated for impairment $ 213 $ 1,035 $ 0 $ 65 $ 0 $ 0 $ 0 $ 0 $ 0 $ 1,313 Collectively evaluated for impairment $ 671 $ 13,156 $ 42 $ 4,591 $ 629 $ 6,027 $ 774 $ 1,885 $ 6,845 $ 34,620 Loans Ending balance: Individually evaluated for impairment $ 5,609 $ 33,756 $ 0 $ 11,354 $ 0 $ 1,483 $ 0 $ 0 $ 0 $ 52,202 Collectively evaluated for impairment $ 61,389 $ 1,051,672 $ 5,512 $ 338,805 $ 57,966 $ 701,486 $ 91,511 $ 133,093 $ 444,735 $ 2,886,169 2015 (in thousands) Commercial Construction Commercial Secured by Real Estate Equipment Lease Financing Commercial Other Real Estate Construction Real Estate Mortgage Home Equity Consumer Direct Consumer Indirect Total ALLL Balance, beginning of year $ 2,896 $ 13,618 $ 119 $ 4,263 $ 534 $ 6,094 $ 756 $ 1,574 $ 4,593 $ 34,447 Provision charged to expense (707 ) 2,135 (40 ) 1,338 147 1,888 158 891 2,840 8,650 Losses charged off (3 ) (1,379 ) 0 (1,961 ) (135 ) (1,421 ) (129 ) (1,306 ) (3,536 ) (9,870 ) Recoveries 13 60 0 585 4 117 54 435 1,599 2,867 Balance, end of year $ 2,199 $ 14,434 $ 79 $ 4,225 $ 550 $ 6,678 $ 839 $ 1,594 $ 5,496 $ 36,094 Ending balance: Individually evaluated for impairment $ 831 $ 1,227 $ 0 $ 403 $ 0 $ 0 $ 0 $ 0 $ 0 $ 2,461 Collectively evaluated for impairment $ 1,368 $ 13,207 $ 79 $ 3,822 $ 550 $ 6,678 $ 839 $ 1,594 $ 5,496 $ 33,633 Loans Ending balance: Individually evaluated for impairment $ 6,263 $ 33,421 $ 0 $ 8,460 $ 0 $ 1,744 $ 0 $ 0 $ 0 $ 49,888 Collectively evaluated for impairment $ 71,757 $ 1,019,498 $ 8,514 $ 350,438 $ 61,750 $ 706,130 $ 89,450 $ 126,406 $ 390,130 $ 2,824,073

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2017
Premises and Equipment [Abstract]
Premises and Equipment	8. Premises and Equipment Premises and equipment are summarized as follows: (in thousands) December 31 2017 2016 Land and buildings $ 79,173 $ 78,086 Leasehold improvements 4,894 4,886 Furniture, fixtures, and equipment 38,096 36,831 Construction in progress 80 769 Total premises and equipment 122,243 120,572 Less accumulated depreciation and amortization (75,925 ) (72,632 ) Premises and equipment, net $ 46,318 $ 47,940 Depreciation and amortization of premises and equipment for 2017, 2016, and 2015 was $3.9 million, $3.7 million, and $3.7 million, respectively.

Other Real Estate Owned

Other Real Estate Owned	12 Months Ended
	Dec. 31, 2017
Other Real Estate Owned [Abstract]
Other Real Estate Owned	9. Other Real Estate Owned Activity for other real estate owned was as follows: (in thousands) 2017 2016 Beginning balance of other real estate owned $ 35,856 $ 40,674 New assets acquired 5,382 5,900 Fair value adjustments (3,034 ) (1,214 ) Sale of assets (6,208 ) (9,504 ) Ending balance of other real estate owned $ 31,996 $ 35,856 Carrying costs and fair value adjustments associated with foreclosed properties were $4.5 million, $2.9 million, and $3.5 million for 2017, 2016, and 2015, respectively. See note 1 for a description of our accounting policies relative to foreclosed properties and other real estate owned. Included in the sale of assets above was the disposal of The major classifications of foreclosed properties are shown in the following table: (in thousands) December 31 2017 2016 1-4 family $ 5,908 $ 6,210 Agricultural/farmland 68 93 Construction/land development/other 16,158 20,778 Multifamily 176 270 Non-farm/non-residential 9,686 8,505 Total foreclosed properties $ 31,996 $ 35,856

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Deposits	10. Deposits Major classifications of deposits are categorized as follows: (in thousands) December 31 2017 2016 Noninterest bearing deposits $ 790,930 $ 767,918 NOW accounts 51,218 45,872 Money market deposits 692,021 649,917 Savings 416,551 404,558 Certificates of deposit and other time deposits of $100,000 or more 759,025 651,882 Certificates of deposit and other time deposits less than $100,000 554,118 561,161 Total deposits $ 3,263,863 $ 3,081,308 Certificates of deposit and other time deposits of $250,000 or more at December 31, 2017 and 2016 were $232.5 million and $228.6 million, respectively. Wholesale brokered deposits at December 31, 2017 totaled $82.3 million. There were no brokered deposits in our 2016 balances. Maturities of certificates of deposits and other time deposits are presented below: Maturities by Period at December 31, 2017 (in thousands) Total Within 1 Year 2 Years 3 Years 4 Years 5 Years After 5 Years Certificates of deposit and other time deposits of $100,000 or more $ 759,025 $ 556,382 $ 61,844 $ 79,013 $ 32,611 $ 29,175 $ 0 Certificates of deposit and other time deposits less than $100,000 554,118 455,593 41,147 22,443 20,149 14,673 113 Total maturities $ 1,313,143 $ 1,011,975 $ 102,991 $ 101,456 $ 52,760 $ 43,848 $ 113

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2017
Borrowings [Abstract]
Borrowings	11. Borrowings Short-term debt is categorized as follows: (in thousands) December 31 2017 2016 Repurchase agreements $ 243,814 $ 251,065 Federal funds purchased 7,312 4,816 Total short-term debt $ 251,126 $ 255,881 All federal funds purchased mature and reprice daily. See note 12 for information regarding the maturities of our repurchase agreements. The average rates paid for federal funds purchased and repurchase agreements on December 31, 2017 were 1.30% and 1.01%, respectively. The maximum balance for repurchase agreements at any month-end during 2017 occurred at September 30, 2017, with a month-end balance of $260.0 million. The average balance of repurchase agreements for the year was $251.0 million. On November 30, 2017, Community Trust Bancorp, Inc. signed an amendment to a revolving credit promissory note, dated October 31, 2014 and last amended February 3, 2017, for a line of credit in the amount of $12 million at a floating interest rate of 2.00% in excess of the one-month LIBOR rate. This amendment extended the maturity date to November 30, 2018 with an unused commitment fee of 0.30%. Currently, all $12 million remains available for general corporate purposes. Long-term debt is categorized as follows: (in thousands) December 31 2017 2016 Junior subordinated debentures, 3.07%, due 6/1/37 $ 59,341 $ 61,341 On March 30, 2007, CTBI issued $61.3 million in junior subordinated debentures to a newly formed unconsolidated Delaware statutory trust subsidiary which in turn issued $59.5 million of capital securities in a private placement to institutional investors. The debentures, which mature in 30 years but are redeemable at par at CTBI’s option after five years, were issued at a rate of 6.52% until June 1, 2012, and thereafter at a floating rate based on the three-month LIBOR plus 1.59%. The underlying capital securities were issued at the equivalent rates and terms. The proceeds of the debentures were used to fund the redemption on April 2, 2007 of all CTBI’s outstanding 9.0% and 8.25% junior subordinated debentures in the total amount of $61.3 million. In May 2017, CTBI was able to purchase $2.0 million of the junior subordinated debentures in the open market at a purchase price of $1.4 million, resulting in a gain of $0.6 million. The junior subordinated debentures will be retained by CTBI until maturity, and CTBI will continue to report the junior subordinated debentures at the net amount outstanding of $59.3 million. On November 29, 2017, the coupon rate was set at 3.07% for the March 1, 2018 distribution date, which was based on the three-month LIBOR rate as of November 29, 2017 of 1.48% plus 1.59%.

Repurchase Agreements

Repurchase Agreements	12 Months Ended
	Dec. 31, 2017
Repurchase Agreements [Abstract]
Repurchase Agreements	12. Repurchase Agreements We utilize securities sold under agreements to repurchase to facilitate the needs of our customers and provide additional funding to our balance sheet. Repurchase agreements are transactions whereby we offer to sell to a counterparty an undivided interest in an eligible security at an agreed upon purchase price, and which obligates CTBI to repurchase the security on an agreed upon date at an agreed upon repurchase price plus interest at an agreed upon rate. Securities sold under agreements to repurchase are recorded at the amount of cash received in connection with the transaction and are reflected in the accompanying consolidated balance sheets. We monitor collateral levels on a continuous basis and maintain records of each transaction specifically describing the applicable security and the counterparty’s fractional interest in that security, and we segregate the security from its general assets in accordance with regulations governing custodial holdings of securities. The primary risk with our repurchase agreements is market risk associated with the securities securing the transactions, as we may be required to provide additional collateral based on fair value changes of the underlying securities. Securities pledged as collateral under repurchase agreements are maintained with our safekeeping agents. The carrying value of investment securities available for sale pledged as collateral under repurchase agreements totaled $295.4 million and $302.3 million at December 31, 2017 and December 31, 2016, respectively. The remaining contractual maturity of the securities sold under agreements to repurchase by class of collateral pledged included in the accompanying consolidated balance sheets as of December 31, 2017 and December 31, 2016 is presented in the following tables: December 31, 2017 Remaining Contractual Maturity of the Agreements (in thousands) Overnight and Up to 30 days 30-90 days Greater Than Total Repurchase agreements and U.S. Treasury and government agencies $ 24,957 $ 0 $ 16,771 $ 67,867 $ 109,595 State and political subdivisions 62,620 0 567 12,161 75,348 U.S. government sponsored agency mortgage-backed securities 13,360 0 4,662 40,849 58,871 Total $ 100,937 $ 0 $ 22,000 $ 120,877 $ 243,814 December 31, 2016 Remaining Contractual Maturity of the Agreements (in thousands) Overnight and Up to 30 days 30-90 days Greater Than Total Repurchase agreements and U.S. Treasury and government agencies $ 17,249 $ 0 $ 14,349 $ 73,076 $ 104,674 State and political subdivisions 55,354 0 1,998 10,272 67,624 U.S. government sponsored agency mortgage-backed securities 23,386 0 8,003 47,378 78,767 Total $ 95,989 $ 0 $ 24,350 $ 130,726 $ 251,065

Advances from Federal Home Loan

Advances from Federal Home Loan Bank	12 Months Ended
	Dec. 31, 2017
Advances from Federal Home Loan Bank [Abstract]
Advances from Federal Home Loan Bank	13. Advances from Federal Home Loan Bank Federal Home Loan Bank advances consisted of the following monthly amortizing borrowings at December 31: (in thousands) 2017 2016 Monthly amortizing $ 845 $ 944 Total FHLB advances $ 845 $ 944 The advances from the FHLB that require monthly principal payments were due for repayment as follows: Principal Payments Due by Period at December 31, 2017 (in thousands) Total Within 1 Year 2 Years 3 Years 4 Years 5 Years After 5 Years Outstanding advances, weighted average interest rate – 1.14% $ 845 $ 411 $ 20 $ 20 $ 20 $ 21 $ 353 At December 31, 2016, CTBI had monthly amortizing FHLB advances totaling $0.9 million at a weighted average interest rate of 1.33%. Advances totaling $0.8 million at December 31, 2017 were collateralized by FHLB stock of $17.9 million and a blanket lien on qualifying 1-4 family first mortgage loans. As of December 31, 2017, CTBI had a $547.8 million FHLB borrowing capacity with $0.8 million in advances and $251.5 million in letters of credit used for public fund pledging leaving $295.5 million available for additional advances. The advances had fixed interest rates ranging from 0.00% to 4.85% with a weighted average rate of 1.14%. The advances are subject to restrictions or penalties in the event of prepayment.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Taxes [Abstract]
Income Taxes	14. Income Taxes The components of the provision for income taxes, exclusive of tax effect of unrealized securities gains and losses, are as follows: (in thousands) 2017 2016 2015 Current income tax expense $ 20,108 $ 18,417 $ 18,416 Deferred income tax expense (259 ) 701 115 Effect of Tax Cuts & Jobs Act (benefit) (2,831 ) - - Total income tax expense $ 17,018 $ 19,118 $ 18,531 The Tax Cuts and Jobs Act (the "Act") was enacted in December 2017. The Act reduces the U.S. federal corporate tax rate from 35 percent to 21 percent. As of December 31, 2017, we have substantially completed our accounting for the tax effects of enactment of the Act; however, in certain cases, we have made a reasonable estimate of the effects on our existing deferred tax balances. We do not believe the actual results will vary materially from those estimates. The effect of the Tax Cuts and Jobs Act (benefit) listed above reflects the revaluation of our net deferred tax liability based on a U.S. federal tax rate of 21 percent. A reconciliation of income tax expense at the statutory rate to our actual income tax expense is shown below: (in thousands) 2017 2016 2015 Computed at the statutory rate $ 23,979 35.00 % $ 23,262 35.00 % $ 22,737 35.00 % Adjustments resulting from: Tax-exempt interest (1,259 ) (1.84 ) (1,289 ) (1.94 ) (1,275 ) (1.96 ) Housing and new markets credits (2,579 ) (3.76 ) (2,680 ) (4.03 ) (2,692 ) (4.14 ) Dividends received deduction (129 ) (0.19 ) (136 ) (0.20 ) (128 ) (0.20 ) Bank owned life insurance (492 ) (0.72 ) (518 ) (0.78 ) (549 ) (0.84 ) ESOP dividend deduction (319 ) (0.47 ) (313 ) (0.47 ) (298 ) (0.46 ) Stock option exercises and restricted stock vesting (170 ) (0.25 ) - - - - Effect of Tax Cuts & Jobs Act (2,831 ) (4.13 ) - - - - Other, net 818 1.20 792 1.18 736 1.13 Total $ 17,018 24.84 % $ 19,118 28.76 % $ 18,531 28.53 % The components of the net deferred tax liability as of December 31 are as follows: (in thousands) 2017 2016 Deferred tax assets: Allowance for loan and lease losses $ 7,592 $ 12,577 Interest on nonperforming loans 560 806 Accrued expenses 442 1,883 Allowance for other real estate owned 1,322 1,898 Limited partnership investments 64 0 Unrealized losses on AFS securities 932 1,241 Other 204 282 Total deferred tax assets 11,116 18,687 Deferred tax liabilities: Depreciation and amortization (12,270 ) (20,287 ) FHLB stock dividends (2,076 ) (3,460 ) Loan fee income (263 ) (536 ) Mortgage servicing rights (732 ) (1,202 ) Capitalized lease obligations (14 ) (65 ) Limited partnership investments 0 (411 ) Other (195 ) (562 ) Total deferred tax liabilities (15,550 ) (26,523 ) Net deferred tax liability $ (4,434 ) $ (7,836 ) CTBI accounts for income taxes in accordance with income tax accounting guidance (ASC 740, Income Taxes Uncertain tax positions are recognized if it is more likely than not, based on the technical merits, that the tax position will be realized or sustained upon examination. The term more likely than not means a likelihood of more than 50 percent; the terms examined and upon examination also include resolution of the related appeals or litigation processes, if any. A tax position that meets the more-likely-than-not recognition threshold is initially and subsequently measured as the largest amount of tax benefit that has a greater than 50 percent likelihood of being realized upon settlement with a taxing authority that has full knowledge of all relevant information. The determination of whether or not a tax position has met the more-likely-than-not recognition threshold considers the facts, circumstances, and information available at the reporting date and is subject to management’s judgment. With a few exceptions, CTBI is no longer subject to U.S. federal tax examinations by tax authorities for years before 2014, and state and local income tax examinations by tax authorities for years before 2013. For federal tax purposes, CTBI recognizes interest and penalties on income taxes as a component of income tax expense. CTBI files consolidated income tax returns with its subsidiaries.

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2017
Employee Benefits [Abstract]
Employee Benefits	15. Employee Benefits CTBI maintains two separate retirement savings plans, a 401(k) Plan and an Employee Stock Ownership Plan ("ESOP"). The 401(k) Plan is available to all employees (age 21 and over) with one year of service and who work at least 1,000 hours per year. Participants in the plan have the option to contribute from 1% to 20% of their annual compensation. CTBI matches 50% of participant contributions up to 4% of gross pay. CTBI may at its discretion, contribute an additional percentage of covered employees' compensation. CTBI's matching contributions were $ million for the years ended December 31, 2017, 2016, and 2015. The 401(k) Plan owned 406,021, , and 515,062 shares of CTBI's common stock at December 31, 2017, 2016, and 2015, respectively. Substantially all shares owned by the 401(k) were allocated to employee accounts on those dates. The market price of the shares at the date of allocation is essentially the same as the market price at the date of purchase. The ESOP Plan has the same entrance requirements as the 401(k) Plan above. CTBI currently contributes 4% of covered employees' gross compensation to the ESOP. The ESOP uses the contributions to acquire shares of CTBI's common stock. CTBI's contributions to the ESOP were $1.6 million for the year ended December 31, 2017 and $1.5 million for the years ended December 31, 2016 and 2015. The ESOP owned 737,079, , and 765,630 shares of CTBI's common stock at December 31, 2017, 2016, and 2015, respectively. Substantially all shares owned by the ESOP were allocated to employee accounts on those dates. The market price of the shares at the date of allocation is essentially the same as the market price at the date of purchase. Stock-Based Compensation: As of December 31, 2017, CTBI maintained one active and two inactive incentive stock ownership plans covering key employees. The 2015 Stock Ownership Incentive Plan (“2015 Plan”) was approved by the Board of Directors and the Shareholders in 2015. The 2006 Stock Ownership Incentive Plan (“2006 Plan”) was approved by the Board of Directors and the Shareholders in 2006. The 2006 Plan was rendered inactive as of April 28, 2015. The 1998 Stock Option Plan (“1998 Plan”) was approved by the Board of Directors and the Shareholders in 1998. The 1998 Plan was rendered inactive as of April 26, 2006. The 2015 Plan has 550,000 shares authorized, 519,140 of which were available at December 31, 2017. Shares issuable pursuant to awards which were granted under the prior plans on or before their respective expiration or termination dates will be issued from the remaining shares reserved for issuance under the prior plans. The shares of common stock reserved for issuance under the prior plans in excess of the number of shares as to which options or other benefits are awarded thereunder, and any shares as to which options or other benefits granted under the prior plans may lapse, expire, terminate or be canceled, will not be reserved and available for issuance or reissuance under the 2015 Plan. The following table provides detail of the number of shares to be issued upon exercise of outstanding stock-based awards and remaining shares available for future issuance under all of CTBI's equity compensation plans as of December 31, 2017: Plan Category (shares in thousands) Number of Shares to Be Issued Upon Exercise Weighted Average Price Shares Available for Future Issuance Equity compensation plans approved by shareholders: Stock options 45 $ 32.26 519 (a) Restricted stock (c) (b) (a) Performance units (d) (b) (a) Stock appreciation rights (“SARs”) (e) (b) (a) Total 519 (a) Under the 2015 Plan, 550,000 shares are authorized for issuance; 33,668 have been issued as of December 31, 2017. In January of 2016, 18,069 restricted stock shares were issued under the terms of the 2015 Plan pursuant to awards granted under the 2006 Plan. Additional shares will not be issued pursuant to awards granted from prior plans. (b) Not applicable (c) The maximum number of shares of restricted stock that may be granted is 550,000 shares, and the maximum that may be granted to a participant during any calendar year is 75,000 shares. (d) No performance units payable in stock had been issued as of December 31, 2017. The maximum payment that can be made pursuant to performance units granted to any one participant in any calendar year shall be $1,000,000. (e) No SARS have been issued. The maximum number of shares with respect to which SARs may be granted to a participant during any calendar year shall be 100,000 shares. The following table details the shares available for future issuance under the 2015 Plan at December 31, 2017. Plan Category Shares Available for Future Issuance Shares available at January 1, 2017 540,131 Stock option issuances 0 Restricted stock issuances (23,668) Forfeitures 2,677 Shares available for future issuance 519,140 There were no stock options issued in 2017. CTBI uses a Black-Scholes option pricing model with the following weighted average assumptions, which are evaluated and revised as necessary, in estimating the grant-date fair value of each option grant for the year end: 2016 2015 Expected option life (in years) 7.5 7.5 Expected volatility 34.34% 43.11% Expected dividend yield 3.70% 3.72% Risk-free interest rate 1.45% 1.54% The expected life of options granted is estimated from past experience activity and represents the period of time that granted options are expected to be outstanding. The expected volatility is based on historical volatility of the stock using a historical look back that approximates the expected life of the option grant. The interest rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of the grant. CTBI's stock-based compensation expense for the years 2017, 2016, and 2015 was $0.6 million, $0.5 million, and $0.8 million, respectively. Included in stock-based compensation expense were dividends paid on restricted stock shares in the amount of $53 thousand, $37 thousand, and $80 thousand, respectively, for the same periods. The 2015 Plan: CTBI’s stock option activity for the 2015 Plan for the years ended December 31, 2017 and 2016 is summarized as follows: December 31 2017 2016 Options Weighted Average Exercise Price Options Weighted Average Exercise Price Outstanding at beginning of year 10,000 $ 33.55 0 $ 0 Granted 0 0 10,000 33.55 Exercised 0 0 0 0 Forfeited/expired 0 0 0 0 Outstanding at end of year 10,000 $ 33.55 10,000 $ 33.55 Exercisable at end of year 0 $ 0 0 $ 0 A summary of the status of CTBI’s 2015 Plan for nonvested options as of December 31, 2017, and changes during the year ended December 31, 2017, is presented as follows: Nonvested Options Options Weighted Average Grant Date Fair Value Nonvested at January 1, 2017 10,000 $ 6.82 Granted 0 0 Vested 0 0 Forfeited 0 0 Nonvested at December 31, 2017 10,000 $ 6.82 The weighted average remaining contractual term in years of the options outstanding at December 31, 2017 was 8.1 years. There were no options granted from the 2015 Plan for the year ended December 31, 2017. The following table shows the intrinsic values of options exercised, exercisable, and outstanding for the 2015 Plan for the years ended December 31, 2017: (in thousands) 2017 Options exercised $ 0 Options exercisable 0 Outstanding options 136 The following table shows restricted stock activity for the 2015 Plan for the years ended December 31, 2017 and 2016: December 31 2017 2016 Grants Weighted Average Fair Value at Grant Grants Weighted Average Fair Value at Grant Outstanding at beginning of year 17,496 $ 33.55 0 $ 0 Granted* 23,668 46.45 18,069 33.55 Vested (5,751 ) 35.79 (442 ) 33.55 Forfeited (2,328 ) 41.31 (131 ) 33.55 Outstanding at end of year 33,085 $ 41.84 17,496 $ 33.55 * Grants issued in 2016 were issued under the terms of the 2015 Plan pursuant to awards granted and earned under the 2006 Plan. The 2006 Plan: CTBI’s stock option activity for the 2006 Plan for the years ended December 31, 2017, 2016, and 2015 is summarized as follows: December 31 2017 2016 2015 Options Weighted Average Exercise Price Options Weighted Average Exercise Price Options Weighted Average Exercise Price Outstanding at beginning of year 61,041 $ 29.84 118,574 $ 32.36 98,821 $ 32.35 Granted 0 0 0 0 20,000 32.27 Exercised (25,665 ) 27.01 (57,423 ) 35.02 (247 ) 24.12 Forfeited/expired 0 0 (110 ) 35.41 0 0 Outstanding at end of year 35,376 $ 31.90 61,041 $ 29.84 118,574 $ 32.36 Exercisable at end of year 5,376 $ 25.22 30,629 $ 26.64 87,749 $ 32.12 A summary of the status of CTBI’s 2006 Plan for nonvested options as of December 31, 2017, and changes during the year ended December 31, 2017, is presented as follows: Nonvested Options Options Weighted Average Grant Date Fair Value Nonvested at January 1, 2017 30,412 $ 7.00 Granted 0 0 Vested (412 ) 8.23 Forfeited 0 0 Nonvested at December 31, 2017 30,000 $ 6.98 The weighted average remaining contractual term in years of the options outstanding at December 31, 2017 was 6.0 years. There were no options granted from the 2006 Plan for the years 2017 and 2016. The weighted-average fair value of options granted from the 2006 Plan during the year 2015 was $0.1 million or $6.60 per share. The following table shows the intrinsic values of options exercised, exercisable, and outstanding for the 2006 Plan for the years ended December 31, 2017, 2016, and 2015: (in thousands) 2017 2016 2015 Options exercised $ 537 $ 139 $ 3 Options exercisable 118 703 275 Outstanding options 538 1,206 334 The following table shows restricted stock activity for the years ended December 31, 2017, 2016, and 2015: December 31 2017 2016 2015 Grants Weighted Average Fair Value at Grant Grants Weighted Average Fair Value at Grant Grants Weighted Average Fair Value at Grant Outstanding at beginning of year 11,989 $ 32.85 64,735 $ 28.92 101,309 $ 26.19 Granted 0 0 0 0 10,582 32.27 Vested (6,214 ) 32.48 (52,521 ) 28.01 (46,482 ) 23.66 Forfeited (349 ) 33.31 (225 ) 32.52 (674 ) 33.31 Outstanding at end of year 5,426 $ 33.24 11,989 $ 32.85 64,735 $ 28.92 The 1998 Plan: The 1998 Plan had no outstanding options and no activity for the year ended December 31, 2017. CTBI’s stock option activity for the 1998 Plan for the years ended December 31, 2016 and 2015 is summarized as follows: December 31 2016 2015 Options Weighted Average Exercise Price Options Weighted Average Exercise Price Outstanding at beginning of year 2,980 $ 29.49 43,960 $ 29.43 Granted 0 0 0 0 Exercised (2,980 ) 29.49 (40,980 ) 29.42 Forfeited/expired 0 0 0 0 Outstanding at end of year 0 $ 0 2,980 $ 29.49 Exercisable at end of year 0 $ 0 2,980 $ 29.49 The following table shows the intrinsic values of options exercised, exercisable, and outstanding for the 1998 Plan for the years ended December 31, 2016 and 2015: (in thousands) 2016 2015 Options exercised $ 13 $ 241 Options exercisable 0 16 Outstanding options 0 16 There were no nonvested options in the 1998 Plan for the years December 31, 2017, 2016, and 2015. The following table shows the unrecognized compensation cost related to nonvested share-based compensation arrangements granted under the plans at December 31, 2017, 2016, and 2015 and the total grant-date fair value of shares vested, cash received from option exercises under all share-based payment arrangements, and the actual tax benefit realized for the tax deductions from option exercises of the share-based payment arrangements for the years ended December 31, 2017, 2016, and 2015. (in thousands) 2017 2016 2015 Unrecognized compensation cost of unvested share-based compensation arrangements granted under the plan at year-end $ 1,242 $ 835 $ 495 Grant date fair value of shares vested for the year 564 1,490 1,111 Cash received from option exercises under all share-based payment arrangements for the year 693 2,099 1,212 Tax benefit realized for the tax deductions from option exercises of the share-based payment arrangements for the year 138 3 82 The unrecognized compensation cost related to nonvested share-based compensation arrangements granted under the plans at December 31, 2017 is expected to be recognized over a weighted-average period of 2.6 years.

Operating Leases

Operating Leases	12 Months Ended
	Dec. 31, 2017
Operating Leases [Abstract]
Operating Leases	16. Operating Leases Certain premises and equipment are leased under operating leases. Additionally, certain premises are leased or subleased to third parties. These leases generally contain renewal options and require CTBI to pay all executory costs, such as taxes, maintenance fees, and insurance. Minimum non-cancellable rental payments and rental receipts are as follows: (in thousands) Payments Receipts 2018 $ 2,050 $ 574 2019 1,673 411 2020 1,626 351 2021 1,515 235 2022 1,392 100 Thereafter 3,783 145 Total $ 12,039 $ 1,816 Rental expense net of rental income under operating leases was $1.4 million for 2017, $1.3 million for 2016, and $1.3 million for 2015.

Fair Market Value of Financial

Fair Market Value of Financial Assets and Liabilities	12 Months Ended
	Dec. 31, 2017
Fair Market Value of Financial Assets and Liabilities [Abstract]
Fair Market Value of Financial Assets and Liabilities	17. Fair Market Value of Financial Assets and Liabilities Fair Value Measurements ASC 820, Fair Value Measurements Level 1 Inputs – Quoted prices in active markets for identical assets or liabilities. Level 2 Inputs - Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These might include quoted prices for similar assets and liabilities in active markets, and inputs other than quoted prices that are observable for the asset or liability, such as interest rates and yield curves that are observable at commonly quoted intervals. Level 3 Inputs - Unobservable inputs for determining the fair values of assets or liabilities that reflect an entity’s own assumptions about the assumptions that market participants would use in pricing the assets or liabilities. Recurring Measurements The following tables present the fair value measurements of assets recognized in the accompanying balance sheets measured at fair value on a recurring basis as of December 31, 2017 and December 31, 2016 and indicate the level within the fair value hierarchy of the valuation techniques. (in thousands) Fair Value Measurements at December 31, 2017 Using Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets measured – recurring basis Available-for-sale securities: U.S. Treasury and government agencies $ 210,572 $ 64,598 $ 145,974 $ 0 State and political subdivisions 145,015 0 145,015 0 U.S. government sponsored agenc y mortgage-backed securities 205,309 0 205,309 0 Other debt securities 507 0 507 0 CRA investment funds 24,358 24,358 0 0 Mortgage servicing rights 3,484 0 0 3,484 (in thousands) Fair Value Measurements at December 31, 2016 Using Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets measured – recurring basis Available-for-sale securities: U.S. Treasury and government agencies $ 222,464 $ 44,934 $ 177,530 $ 0 State and political subdivisions 133,516 0 133,516 0 U.S. government sponsored agenc y mortgage-backed securities 225,056 0 225,056 0 Other debt securities 0 0 0 0 CRA investment funds 24,358 24,358 0 0 Mortgage servicing rights 3,433 0 0 3,433 Following is a description of the valuation methodologies and inputs used for assets measured at fair value on a recurring basis and recognized in the accompanying balance sheets, as well as the general classification of such assets pursuant to the valuation hierarchy. These valuation methodologies were applied to all of CTBI’s financial assets carried at fair value. CTBI had no liabilities measured and recorded at fair value as of December 31, 2017 and December 31, 2016. There have been no significant changes in the valuation techniques during the year ended December 31, 2017. For assets classified within Level 3 of the fair value hierarchy, the process used to develop the reported fair value is described below. Available-for-Sale Securities Securities classified as available-for-sale are reported at fair value on a recurring basis. U.S. Treasury and government agencies and CTBI’s CRA investment funds are classified as Level 1 of the valuation hierarchy where quoted market prices are available in the active market on which the individual securities are traded. If quoted market prices are not available, CTBI obtains fair value measurements from an independent pricing service, such as Interactive Data, which utilizes pricing models to determine fair value measurement. CTBI reviews the pricing quarterly to verify the reasonableness of the pricing. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other factors. U.S. Treasury and government agencies, state and political subdivisions, U.S. government sponsored agency mortgage-backed securities, and other debt securities are classified as Level 2 inputs. In certain cases where Level 1 or Level 2 inputs are not available, securities are classified within Level 3 of the hierarchy. Fair value determinations for Level 3 measurements are estimated on a quarterly basis where assumptions used are reviewed to ensure the estimated fair value complies with accounting standards generally accepted in the United States. As of December 31, 2017, CTBI does not own any securities valued using Level 3 inputs. Mortgage Servicing Rights Mortgage servicing rights do not trade in an active, open market with readily observable prices. CTBI reports mortgage servicing rights at fair value on a recurring basis with subsequent remeasurement of MSRs based on change in fair value. In determining fair value, CTBI utilizes the expertise of an independent third party. Accordingly, fair value is determined by the independent third party by utilizing assumptions about factors such as mortgage interest rates, discount rates, mortgage loan prepayment speeds, market trends and industry demand. Due to the nature of the valuation inputs, mortgage servicing rights are classified within Level 3 of the hierarchy. Fair value determinations for Level 3 measurements of mortgage servicing rights are tested for impairment on a quarterly basis where assumptions used are reviewed to ensure the estimated fair value complies with accounting standards generally accepted in the United States. See the table below for inputs and valuation techniques used for Level 3 mortgage servicing rights. Transfers between Levels There were no transfers between Levels 1, 2, and 3 as of December 31, 2017. Level 3 Reconciliation Following is a reconciliation of the beginning and ending balances of recurring fair value measurements recognized in the accompanying balance sheet using significant unobservable (Level 3) inputs: Mortgage Servicing Rights (in thousands) 2017 2016 Beginning balance $ 3,433 $ 3,236 Total recognized gains (losses) Included in net income 91 164 Issues 412 521 Settlements (452 ) (488 ) Ending balance $ 3,484 $ 3,433 Total gains (losses) for the period included in net income attributable to the change in unrealized gains or losses related to assets still held at the reporting date $ 91 $ 164 Realized and unrealized gains and losses for items reflected in the table above are included in net income in the consolidated statements of income as follows: Noninterest Income (in thousands) 2017 2016 Total losses $ (361 ) $ (324 ) Nonrecurring Measurements The following tables present the fair value measurements of assets recognized in the accompanying balance sheets measured at fair value on a nonrecurring basis as of December 31, 2017 and December 31, 2016 and indicate the level within the fair value hierarchy of the valuation techniques. (in thousands) Fair Value Measurements at December 31, 2017 Using Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets measured – nonrecurring basis Impaired loans (collateral dependent) $ 2,709 $ 0 $ 0 $ 2,709 Other real estate owned 18,951 0 0 18,951 (in thousands) Fair Value Measurements at December 31, 2016 Using Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets measured – nonrecurring basis Impaired loans (collateral dependent) $ 5,506 $ 0 $ 0 $ 5,506 Other real estate owned 4,388 0 0 4,388 Following is a description of the valuation methodologies and inputs used for assets measured at fair value on a nonrecurring basis and recognized in the accompanying balance sheet, as well as the general classification of such assets pursuant to the valuation hierarchy. For assets classified within Level 3 of the fair value hierarchy, the process used to develop the reported fair value is described below. Impaired Loans (Collateral Dependent) The estimated fair value of collateral-dependent impaired loans is based on the appraised fair value of the collateral, less estimated cost to sell. Collateral-dependent impaired loans are classified within Level 3 of the fair value hierarchy. CTBI considers the appraisal or evaluation as the starting point for determining fair value and then considers other factors and events in the environment that may affect the fair value. Appraisals of the collateral underlying collateral-dependent loans are obtained when the loan is determined to be collateral-dependent and subsequently as deemed necessary by the Chief Credit Officer. Appraisals are reviewed for accuracy and consistency by the Chief Credit Officer. Appraisers are selected from the list of approved appraisers maintained by management. The appraised values are reduced by discounts to consider lack of marketability and estimated cost to sell if repayment or satisfaction of the loan is dependent on the sale of the collateral. These discounts and estimates are developed by the Chief Credit Officer by comparison to historical results. Loans considered impaired under ASC 310-35, Impairment of a Loan, Other Real Estate Owned In accordance with the provisions of ASC 360, Property, Plant, and Equipment, Our policy for determining the frequency of periodic reviews is based upon consideration of the specific properties and the known or perceived market fluctuations in a particular market and is typically between 12 and 18 months but generally not more than 24 months. Appraisers are selected from the list of approved appraisers maintained by management. Unobservable (Level 3) Inputs The following tables present quantitative information about unobservable inputs used in recurring and nonrecurring Level 3 fair value measurements at December 31, 2017 and December 31, 2016. (in thousands) Quantitative Information about Level 3 Fair Value Measurements Fair Value at December 31, 2017 Valuation Technique(s) Unobservable Input Range (Weighted Average) Mortgage servicing rights $ 3,484 Discount cash flows, computer pricing model Constant prepayment rate 7.0% - 45.0% (10.0%) Probability of default 0.0% - 100.0% (3.0%) Discount rate 10.0% - 11.5% (10.1%) Impaired loans (collateral-dependent) $ 2,709 Market comparable properties Marketability discount 1.9% - 89.8% (38.5%) Other real estate owned $ 18,951 Market comparable properties Comparability adjustments 6.0% - 58.6% (15.0%) (in thousands) Quantitative Information about Level 3 Fair Value Measurements Fair Value at December 31, 2016 Valuation Technique(s) Unobservable Input Range (Weighted Average) Mortgage servicing rights $ 3,433 Discount cash flows, computer pricing model Constant prepayment rate 7.0% - 27.0% (9.5%) Probability of default 0.0% - 100.0% (3.0%) Discount rate 10.0% - 11.5% (10.1%) Impaired loans (collateral-dependent) $ 5,506 Market comparable properties Marketability discount 0.0% - 100.0% (33.7%) Other real estate owned $ 4,388 Market comparable properties Comparability adjustments 10.0% - 100.0% (14.9%) Sensitivity of Significant Unobservable Inputs The following is a discussion of the sensitivity of significant unobservable inputs, the interrelationships between those inputs and other unobservable inputs used in recurring fair value measurement and of how those inputs might magnify or mitigate the effect of changes in the unobservable inputs on the fair value measurement. Mortgage Servicing Rights Fair market value for mortgage servicing rights is derived based on unobservable inputs, such as prepayment speeds of the underlying loans generated using the Andrew Davidson Prepayment Model, FHLMC/FNMA guidelines, the weighted-average life of the loan, the discount rate, the weighted average coupon, and the weighted average default rate. Significant increases (decreases) in either of those inputs in isolation would result in a significantly lower (higher) fair value measurement. Generally, a change in the assumption used for prepayment speeds is accompanied by a directionally opposite change in the assumption for interest rates. Fair Value of Financial Instruments The following table presents estimated fair value of CTBI’s financial instruments as of December 31, 2017 and indicates the level within the fair value hierarchy of the valuation techniques. (in thousands) Fair Value Measurements at December 31, 2017 Using Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets: Cash and cash equivalents $ 175,274 $ 175,274 $ 0 $ 0 Certificates of deposit in other banks 9,800 0 9,772 0 Securities available-for-sale 585,761 88,956 496,805 0 Securities held-to-maturity 659 0 660 0 Loans held for sale 1,033 1,060 0 0 Loans, net 3,086,789 0 0 3,092,437 Federal Home Loan Bank stock 17,927 0 17,927 0 Federal Reserve Bank stock 4,887 0 4,887 0 Accrued interest receivable 13,338 0 13,338 0 Mortgage servicing rights 3,484 0 0 3,484 Financial liabilities: Deposits $ 3,263,863 $ 790,930 $ 2,319,278 $ 0 Repurchase agreements 243,814 0 0 243,932 Federal funds purchased 7,312 0 7,312 0 Advances from Federal Home Loan Bank 845 0 841 0 Long-term debt 59,341 0 0 44,166 Accrued interest payable 2,228 0 2,228 0 Unrecognized financial instruments: Letters of credit $ 0 $ 0 $ 0 $ 0 Commitments to extend credit 0 0 0 0 Forward sale commitments 0 0 0 0 The following table presents estimated fair value of CTBI’s financial instruments as of December 31, 2016 and indicates the level within the fair value hierarchy of the valuation techniques. (in thousands) Fair Value Measurements at December 31, 2016 Using Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets: Cash and cash equivalents $ 144,716 $ 144,716 $ 0 $ 0 Certificates of deposit in other banks 980 0 982 0 Securities available-for-sale 605,394 69,292 536,102 0 Securities held-to-maturity 866 0 867 0 Loans held for sale 1,244 1,260 0 0 Loans, net 2,902,438 0 0 2,882,348 Federal Home Loan Bank stock 17,927 0 17,927 0 Federal Reserve Bank stock 4,887 0 4,887 0 Accrued interest receivable 11,922 0 11,922 0 Mortgage servicing rights 3,433 0 0 3,433 Financial liabilities: Deposits $ 3,081,308 $ 767,918 $ 2,321,690 $ 0 Repurchase agreements 251,065 0 0 250,820 Federal funds purchased 4,816 0 4,816 0 Advances from Federal Home Loan Bank 944 0 1,009 0 Long-term debt 61,341 0 0 49,073 Accrued interest payable 1,200 0 1,200 0 Unrecognized financial instruments: Letters of credit $ 0 $ 0 $ 0 $ 0 Commitments to extend credit 0 0 0 0 Forward sale commitments 0 0 0 0 The following methods and assumptions were used to estimate the fair value of each class of financial instruments for which it is practicable to estimate that value: Cash and cash equivalents – The carrying amount approximates fair value. Certificates of deposit in other banks – Fair values are based on quoted market prices or dealer quotes for similar instruments. Securities held-to-maturity – Fair values are based on quoted market prices, if available. If a quoted price is not available, fair value is estimated using quoted prices for similar securities. The fair value estimate is provided to management from a third party using modeling assumptions specific to each type of security that are reviewed and approved by management. Quarterly sampling of fair values provided by additional third parties supplement the fair value review process. Loans held for sale – The fair value is predetermined at origination based on sale price. Loans (net of the allowance for loan and lease losses) – The fair value of fixed rate loans and variable rate mortgage loans is estimated by discounting the future cash flows using current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities. For other variable rate loans, the carrying amount approximates fair value. Federal Home Loan Bank stock – The carrying value of Federal Home Loan Bank stock approximates fair value based on the redemption provisions of the Federal Home Loan Bank. Federal Reserve Bank stock – The carrying value of Federal Reserve Bank stock approximates fair value based on the redemption provisions of the Federal Reserve Bank. Accrued interest receivable – The carrying amount approximates fair value. Deposits – The fair value of fixed maturity time deposits is estimated by discounting the future cash flows using the rates currently offered for deposits of similar remaining maturities. For deposits including demand deposits, savings accounts, NOW accounts, and certain money market accounts, the carrying value approximates fair value. Repurchase agreements – The fair value is estimated by discounting future cash flows using current rates. Federal funds purchased – The carrying amount approximates fair value. Advances from Federal Home Loan Bank – The fair value of these fixed-maturity advances is estimated by discounting future cash flows using rates currently offered for advances of similar remaining maturities. Long-term debt – The fair value is estimated by discounting future cash flows using current rates. Accrued interest payable – The carrying amount approximates fair value. Commitments to originate loans, forward sale commitments, letters of credit, and lines of credit – The fair value of commitments to originate loans is estimated using the fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and the present creditworthiness of the counterparties. For fixed-rate loan commitments, fair value also considers the difference between current levels of interest rates and the committed rates. The fair value of forward sale commitments is estimated based on current market prices for loans of similar terms and credit quality. The fair values of letters of credit and lines of credit are based on fees currently charged for similar agreements or on the estimated cost to terminate or otherwise settle the obligations with the counterparties at the reporting date. The fair values of these commitments are not material.

Off-Balance Sheet Transactions

Off-Balance Sheet Transactions and Guarantees	12 Months Ended
	Dec. 31, 2017
Off-Balance Sheet Transactions and Guarantees [Abstract]
Off-Balance Sheet Transactions and Guarantees	18. Off-Balance Sheet Transactions and Guarantees CTBI is a party to transactions with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include standby letters of credit and commitments to extend credit in the form of unused lines of credit. CTBI uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments. At December 31, CTBI had the following off-balance sheet financial instruments, whose approximate contract amounts represent additional credit risk to CTBI: (in thousands) 2017 2016 Standby letters of credit $ 29,308 $ 29,917 Commitments to extend credit 516,731 570,467 Total off-balance sheet financial instruments $ 546,039 $ 600,384 Standby letters of credit represent conditional commitments to guarantee the performance of a third party. The credit risk involved is essentially the same as the risk involved in making loans. At December 31, 2017, we maintained a credit loss reserve recorded in other liabilities of approximately $7 thousand relating to these financial standby letters of credit. The reserve coverage calculation was determined using essentially the same methodology as used for the allowance for loan and lease losses. Approximately 64% of the total standby letters of credit are secured, with $15.3 million of the total $29.3 million secured by cash. Collateral for the remaining secured standby letters of credit varies but is comprised primarily of accounts receivable, inventory, property, equipment, and income-producing properties. Commitments to extend credit are agreements to originate loans to customers as long as there is no violation of any condition of the contract. At December 31, 2017, a credit loss reserve recorded in other liabilities of $248 thousand was maintained relating to these commitments. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since a portion of the commitments may expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. Each customer’s creditworthiness is evaluated on a case-by-case basis. The amount of collateral obtained, if deemed necessary, is based on management’s credit evaluation of the counterparty. Collateral held varies, but may include accounts receivable, inventory, property, plant and equipment, commercial real estate, and residential real estate. A portion of the commitments is to extend credit at fixed rates. Fixed rate loan commitments at December 31, 2017 of $52.2 million had interest rates ranging predominantly from 3.00% to 5.00%, respectively, and terms predominantly two years or less. These credit commitments were based on prevailing rates, terms, and conditions applicable to other loans being made at December 31, 2017. Included in our commitments to extend credit are mortgage loans in the process of origination which are intended for sale to investors in the secondary market. These forward sale commitments are on an individual loan basis that CTBI originates as part of its mortgage banking activities. CTBI commits to sell the loans at specified prices in a future period, typically within 60 days. These commitments are acquired to reduce market risk on mortgage loans in the process of origination and mortgage loans held for sale since CTBI is exposed to interest rate risk during the period between issuing a loan commitment and the sale of the loan into the secondary market. Total mortgage loans in the process of origination amounted to $2.5 million and $2.9 million at December 31, 2017 and 2016, respectively, and mortgage loans held for sale amounted to $1.0 million and $1.2 million for the years ended December 31, 2017 and 2016, respectively.

Concentrations of Credit Risk

Concentrations of Credit Risk	12 Months Ended
	Dec. 31, 2017
Concentrations of Credit Risk [Abstract]
Concentrations of Credit Risk	19. Concentrations of Credit Risk CTBI’s banking activities include granting commercial, residential, and consumer loans to customers primarily located in eastern, northeastern, central, and south central Kentucky, southern West Virginia, and northeastern Tennessee. CTBI is continuing to manage all components of its portfolio mix in a manner to reduce risk from changes in economic conditions. Concentrations of credit, as defined for regulatory purposes, are reviewed quarterly by management to ensure that internally established limits based on Tier 1 Capital plus the allowance for loan and lease losses are not exceeded. At December 31, 2017 and 2016, our concentrations of hotel/motel industry credits were 47% and 41% of Tier 1 Capital plus the allowance for loan and lease losses, respectively. Lessors of non-residential buildings credits were 45% and 45%, respectively. Lessors of residential buildings and dwellings were 39% and 37%, respectively. These percentages are within our internally established limits regarding concentrations of credit.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies [Abstract]
Commitments and Contingencies	20. Commitments and Contingencies CTBI and our subsidiaries, and from time to time, our officers, are named defendants in legal actions arising from ordinary business activities. Management, after consultation with legal counsel, believes any pending actions at December 31, 2017 are without merit or that the ultimate liability, if any, will not materially affect our consolidated financial position or results of operations. CTB will be required to make certain customer reimbursements related to two deposit add-on products. As previously discussed in CTBI’s prior year Form 10-K and most recent Form 10-Q, management established a related accrual in 2014, which was not considered material. The time period and amount of the reimbursements have not yet been determined; therefore, the actual amount may materially vary from the amount management has evaluated as most likely at December 31, 2017.

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2017
Regulatory Matters [Abstract]
Regulatory Matters	21. Regulatory Matters CTBI’s principal source of funds is dividends received from our banking subsidiary, CTB. Regulations limit the amount of dividends that may be paid by CTB without prior approval. During 2018, approximately $56.1 million plus any 2018 net profits can be paid by CTB without prior regulatory approval. The Federal Reserve Bank adopted quantitative measures which assign risk weightings to assets and off-balance sheet items and also define and set minimum regulatory capital requirements (risk based capital ratios). All banks are required to have a minimum Tier 1 (core capital) leverage ratio of 4% of adjusted quarterly average assets, common equity Tier 1 capital ratio of at least 4.5% of risk-weighted assets, Tier 1 capital of at least 6% of risk-weighted assets, and total capital of at least 8% of risk-weighted assets. Tier 1 capital consists principally of shareholders’ equity including capital-qualifying subordinated debt but excluding unrealized gains and losses on securities available-for-sale, less goodwill and certain other intangibles. Total capital consists of Tier 1 capital plus certain debt instruments and the reserve for credit losses, subject to limitation. Failure to meet certain capital requirements can initiate certain actions by regulators that, if undertaken, could have a direct material effect on our consolidated financial statements. The regulations also define well-capitalized levels of Tier 1 leverage, common equity Tier 1 capital, Tier 1, and total capital as 5%, 6.5%, 8%, and 10%, respectively. We had Tier 1 leverage, common equity Tier 1 capital, Tier 1, and total capital ratios above the well-capitalized levels at December 31, 2017 and 2016. We believe, as of December 31, 2017, CTBI meets all capital adequacy requirements for which it is subject to be defined as well-capitalized under the regulatory framework for prompt corrective action. Under the current Federal Reserve Board’s regulatory framework, certain capital securities offered by wholly owned unconsolidated trust preferred entities of CTBI are included as Tier 1 regulatory capital. On March 1, 2005, the Federal Reserve Board adopted a final rule that allows the continued limited inclusion of trust preferred securities in the Tier 1 capital of bank holding companies (“BHCs”). Under the final rule, trust preferred securities and other restricted core capital elements are subject to stricter quantitative limits. Consolidated Capital Ratios Actual For Capital Adequacy Purposes (in thousands) Amount Ratio Amount Ratio As of December 31, 2017: Tier 1 capital (to average assets) $ 525,707 12.89 % $ 163,136 4.00 % Common equity Tier 1 capital (to risk weighted assets) 468,207 15.33 137,438 4.50 Tier 1 capital (to risk weighted assets) 525,707 17.22 183,173 6.00 Total capital (to risk weighted assets) 562,114 18.41 244,265 8.00 As of December 31, 2016: Tier 1 capital (to average assets) $ 496,432 12.75 % $ 155,743 4.00 % Common equity Tier 1 capital (to risk weighted assets) 436,932 15.18 129,525 4.50 Tier 1 capital (to risk weighted assets) 496,432 17.25 172,672 6.00 Total capital (to risk weighted assets) 532,332 18.50 230,198 8.00 Community Trust Bank, Inc.’s Capital Ratios Actual For Capital Adequacy Purposes To Be Well-Capitalized Under Prompt Corrective Action Provision (in thousands) Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017: Tier 1 capital (to average assets) $ 501,537 12.35 % $ 162,441 4.00 % $ 203,051 5.00 % Common equity Tier 1 capital (to risk weighted assets) 501,537 16.46 137,115 4.50 198,055 6.50 Tier 1 capital (to risk weighted assets) 501,537 16.46 182,820 6.00 243,760 8.00 Total capital (to risk weighted assets) 537,944 17.65 243,827 8.00 304,784 10.00 As of December 31, 2016: Tier 1 capital (to average assets) $ 472,615 12.19 % $ 155,083 4.00 % $ 193,854 5.00 % Common equity Tier 1 capital (to risk weighted assets) 472,615 16.46 129,208 4.50 186,634 6.50 Tier 1 capital (to risk weighted assets) 472,615 16.46 172,278 6.00 229,704 8.00 Total capital (to risk weighted assets) 508,515 17.71 229,708 8.00 287,134 10.00 On July 2, 2013, the Federal Reserve approved final rules that substantially amend the regulatory risk-based capital rules applicable to CTBI and CTB. The FDIC subsequently approved these rules. The final rules implement the “Basel III” regulatory capital reforms and changes required by the Dodd-Frank Act. The rules include new risk-based capital and leverage ratios, which are being phased in from 2015 to 2019, and refine the definition of what constitutes “capital” for purposes of calculating those ratios. The new minimum capital level requirements applicable to CTBI and CTB under the final rules are: (i) a new common equity Tier 1 capital ratio of 4.5%; (ii) a Tier 1 capital ratio of 6% (increased from 4%); (iii) a total capital ratio of 8% (unchanged from previous rules); and (iv) a Tier 1 leverage ratio of 4% for all institutions. The final rules also establish a “capital conservation buffer” above the new regulatory minimum capital requirements, which must consist entirely of common equity Tier 1 capital. The capital conservation buffer began to be phased in on January 1, 2016 at 0.625% of risk-weighted assets and will increase by 0.625% annually until fully implemented in January 2019. An institution is subject to limitations on certain activities including payment of dividends, share repurchases, and discretionary bonuses to executive officers if its capital level is below the total capital plus capital conservation buffer amount. The final rules also implement revisions and clarifications consistent with Basel III regarding the various components of Tier 1 capital, including common equity, unrealized gains and losses (which are not considered a component of Tier 1 capital), as well as certain instruments that will no longer qualify as Tier 1 capital, some of which will be phased out over time. However, the final rules provide that small depository institution holding companies with less than $15 billion in total assets as of December 31, 2009 (which includes CTBI) will be able to permanently include non-qualifying instruments that were issued and included in Tier 1 or Tier 2 capital prior to May 19, 2010 in additional Tier 1 or Tier 2 capital until they redeem such instruments or until the instruments mature. The final rules also contain revisions to the prompt corrective action framework, which is designed to place restrictions on insured depository institutions, including CTB, if their capital levels begin to show signs of weakness. These revisions took effect January 1, 2015. Under the prompt corrective action requirements, which are designed to complement the capital conservation buffer, insured depository institutions are required to meet the following increased capital level requirements in order to qualify as “well capitalized:” (i) a common equity Tier 1 capital ratio of 6.5%; (ii) a Tier 1 capital ratio of 8% (increased from 6%); (iii) a total capital ratio of 10% (unchanged from previous rules); and (iv) a Tier 1 leverage ratio of 5% (unchanged from previous rules). The final rules set forth certain changes for the calculation of risk-weighted assets, which we were required to utilize beginning January 1, 2015. The standardized approach final rule utilizes an increased number of credit risk exposure categories and risk weights, and also addresses: (i) an alternative standard of creditworthiness consistent with Section 939A of the Dodd-Frank Act; (ii) revisions to recognition of credit risk mitigation; (iii) rules for risk weighting of equity exposures and past due loans; (iv) revised capital treatment for derivatives and repo-style transactions; and (v) disclosure requirements for top-tier banking organizations with $50 billion or more in total assets that are not subject to the “advance approach rules” that apply to banks with greater than $250 billion in consolidated assets. We currently satisfy the well-capitalized and the capital conservation standards, and based on our current capital composition and levels, we anticipate that our capital ratios, on a Basel III basis, will continue to exceed the well-capitalized minimum capital requirements and capital conservation buffer standards.

Parent Company Financial Statem

Parent Company Financial Statements	12 Months Ended
	Dec. 31, 2017
Parent Company Financial Statements [Abstract]
Parent Company Financial Statements	22. Parent Company Financial Statements Condensed Balance Sheets (in thousands) December 31 2017 2016 Assets: Cash on deposit $ 1,500 $ 1,525 Investment in and advances to subsidiaries 587,575 556,975 Goodwill 4,973 4,973 Premises and equipment, net 250 142 Other assets 200 391 Total assets $ 594,498 $ 564,006 Liabilities and shareholders’ equity: Long-term debt $ 61,341 $ 61,341 Other liabilities 2,458 2,050 Total liabilities 63,799 63,391 Shareholders’ equity 530,699 500,615 Total liabilities and shareholders’ equity $ 594,498 $ 564,006 Condensed Statements of Income and Comprehensive Income (in thousands) Year Ended December 31 2017 2016 2015 Income: Dividends from subsidiary banks $ 24,661 $ 20,708 $ 19,808 Other income 904 459 414 Total income 25,565 21,167 20,222 Expenses: Interest expense 1,723 1,417 1,170 Depreciation expense 116 107 130 Other expenses 2,858 2,256 2,465 Total expenses 4,697 3,780 3,765 Income before income taxes and equity in undistributed income of subsidiaries 20,868 17,387 16,457 Income tax benefit (1,445 ) (1,373 ) (1,371 ) Income before equity in undistributed income of subsidiaries 22,313 18,760 17,828 Equity in undistributed income of subsidiaries 29,180 28,586 28,604 Net income $ 51,493 $ 47,346 $ 46,432 Other comprehensive loss: Unrealized holding losses on securities available-for-sale: Unrealized holding losses arising during the period (820 ) (4,578 ) (342 ) Less: Reclassification adjustments for realized gains (losses) included in net income 73 522 (106 ) Tax benefit (312 ) (1,785 ) (83 ) Implementation of ASU 2018-02 (621 ) 0 0 Other comprehensive loss, net of tax (1,202 ) (3,315 ) (153 ) Comprehensive income $ 50,291 $ 44,031 $ 46,279 Condensed Statements of Cash Flows (in thousands) Year Ended December 31 2017 2016 2015 Cash flows from operating activities: Net income $ 51,493 $ 47,346 $ 46,432 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation 116 107 130 Equity in undistributed earnings of subsidiaries (29,180 ) (28,586 ) (28,604 ) Stock-based compensation 636 458 783 Excess tax benefits of stock-based compensation 0 100 104 Gain on debt repurchase (560 ) 0 0 Changes in: Other assets 145 519 240 Other liabilities 412 (90 ) 968 Net cash provided by operating activities 23,062 19,854 20,053 Cash flows from investing activities: Payment for investment in subsidiary (1,440 ) 0 0 Purchase of premises and equipment (179 ) (104 ) (45 ) Net cash used in investing activities (1,619 ) (104 ) (45 ) Cash flows from financing activities: Issuance of common stock 1,513 2,985 2,082 Repurchase of common stock 0 (382 ) (189 ) Excess tax benefits of stock-based compensation 0 (100 ) (104 ) Dividends paid (22,981 ) (22,190 ) (21,330 ) Net cash used in financing activities (21,468 ) (19,687 ) (19,541 ) Net increase (decrease) in cash and cash equivalents (25 ) 63 467 Cash and cash equivalents at beginning of year 1,525 1,462 995 Cash and cash equivalents at end of year $ 1,500 $ 1,525 $ 1,462

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	23. Earnings Per Share The following table sets forth the computation of basic and diluted earnings per share: Year Ended December 31 (in thousands except per share data) 2017 2016 2015 Numerator: Net income $ 51,493 $ 47,346 $ 46,432 Denominator: Basic earnings per share: Weighted average shares 17,631 17,548 17,431 Diluted earnings per share: Dilutive effect of equity grants 22 18 52 Adjusted weighted average shares 17,653 17,566 17,483 Earnings per share: Basic earnings per share $ 2.92 $ 2.70 $ 2.66 Diluted earnings per share 2.92 2.70 2.66 There were no options to purchase common shares that were excluded from the diluted calculations above for the years ended December 31, 2017 and 2016. In addition to in-the-money stock options, unvested restricted stock grants were also used in the calculation of diluted earnings per share based on the treasury method. Options to purchase 58,063 common shares at a weighted average price of $35.409 were excluded from the diluted calculations above for the year ended December 31, 2015, because the exercise prices on the options were greater than the average market price for the period.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income [Abstract]
Accumulated Other Comprehensive Income	24. Accumulated Other Comprehensive Income Unrealized gains (losses) on AFS securities Amounts reclassified from accumulated other comprehensive income (AOCI) and the affected line items in the statements of income during the years ended December 31, 2017, 2016, and 2015 were: Amounts Reclassified from AOCI Year Ended December 31 (in thousands) 2017 2016 2015 Affected line item in the statements of income Securities gains (losses) $ 73 $ 522 $ (106 ) Tax expense (benefit) 26 183 (37 ) Total reclassifications out of AOCI $ 47 $ 339 $ (69 )

Accounting Policies (Policies)

Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
Nature of Operations	Nature of Operations
Use of Estimates	Use of Estimates The accompanying financial statements have been prepared using values and information currently available to CTBI. Given the volatility of current economic conditions, the values of assets and liabilities recorded in the financial statements could change rapidly, resulting in material future adjustments in asset values, the allowance for loan and lease losses, and capital.
Cash and Cash Equivalents	Cash and Cash Equivalents
Certificates of Deposit in Other Banks	Certificates of Deposit in Other Banks
Investments	Investments Investment Securities a. Trading securities . . b. Available-for-sale securities. Investments not classified as trading securities (nor as held-to-maturity securities) shall be classified as available-for-sale securities. We do not have any securities that are classified as trading securities. Available-for-sale securities are reported at fair value, with unrealized gains and losses included as a separate component of shareholders’ equity, net of tax. If declines in fair value are other than temporary, the carrying value of the securities is written down to fair value as a realized loss with a charge to income for the portion attributable to credit losses and a charge to other comprehensive income for the portion that is not credit related. Gains or losses on disposition of securities are computed by specific identification for all securities except for shares in mutual funds, which are computed by average cost. Interest and dividend income, adjusted by amortization of purchase premium or discount, is included in earnings. When the fair value of a security is below its amortized cost, and depending on the length of time the condition exists and the extent the fair market value is below amortized cost, additional analysis is performed to determine whether an other than temporary impairment condition exists. Available-for-sale and held-to-maturity securities are analyzed quarterly for possible other than temporary impairment. The analysis considers (i) whether we have the intent to sell our securities prior to recovery and/or maturity and (ii) whether it is more likely than not that we will not have to sell our securities prior to recovery and/or maturity. Often, the information available to conduct these assessments is limited and rapidly changing, making estimates of fair value subject to judgment. If actual information or conditions are different than estimated, the extent of the impairment of the security may be different than previously estimated, which could have a material effect on the CTBI’s results of operations and financial condition.
Loans	Loans A restructuring of a debt constitutes a troubled debt restructuring if the creditor for economic or legal reasons related to the debtor’s financial difficulties grants a concession to the debtor that it would not otherwise consider. Loan origination and commitment fees and certain direct loan origination costs are deferred and the net amount amortized over the estimated life of the related loans, leases, or commitments as a yield adjustment.
Allowance for Loan and Lease Losses	Allowance for Loan and Lease Losses We utilize an internal risk grading system for commercial credits. Those larger commercial credits that exhibit probable or observed credit weaknesses are subject to individual review. The borrower’s cash flow, adequacy of collateral coverage, and other options available to CTBI, including legal remedies, are evaluated. The review of individual loans includes those loans that are impaired as defined by ASC 310-10-35, Impairment of a Loan A loan is considered impaired when, based on current information and events, it is probable that CTBI will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. Impairment is measured on a loan-by-loan basis for commercial and construction loans by either the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s obtainable market price, or the fair value of the collateral if the loan is collateral dependent. Homogenous loans, such as consumer installment, residential mortgages, and home equity lines are not individually risk graded. The associated ALLL for these loans is measured under ASC 450, Contingencies When any secured commercial loan is considered uncollectable, whether past due or not, a current assessment of the value of the underlying collateral is made. If the balance of the loan exceeds the fair value of the collateral, the loan is placed on nonaccrual and the loan is charged down to the value of the collateral less estimated cost to sell or a specific reserve equal to the difference between book value of the loan and the fair value assigned to the collateral is created until such time as the loan is foreclosed. When the foreclosed collateral has been legally assigned to CTBI, the estimated fair value of the collateral less costs to sell is then transferred to other real estate owned or other repossessed assets, and a charge-off is taken for any remaining balance. When any unsecured commercial loan is considered uncollectable the loan is charged off no later than at 90 days past due. All closed-end consumer loans (excluding conventional 1-4 family residential loans and installment and revolving loans secured by real estate) are charged off no later than 120 days (5 monthly payments) delinquent. If a loan is considered uncollectable, it is charged off earlier than 120 days delinquent. For conventional 1-4 family residential loans and installment and revolving loans secured by real estate, when a loan is 90 days past due, a current assessment of the value of the real estate is made. If the balance of the loan exceeds the fair value of the property, the loan is placed on nonaccrual. Foreclosure proceedings are normally initiated after 120 days. When the foreclosed property has been legally assigned to CTBI, the fair value less estimated costs to sell is transferred to other real estate owned and the remaining balance is taken as a charge-off. Historical loss rates for loans are adjusted for significant factors that, in management’s judgment, reflect the impact of any current conditions on loss recognition. We use twelve rolling quarters for our historical loss rate analysis. Factors that we consider include delinquency trends, current economic conditions and trends, strength of supervision and administration of the loan portfolio, levels of underperforming loans, level of recoveries to prior year’s charge-offs, trends in loan losses, industry concentrations and their relative strengths, amount of unsecured loans, and underwriting exceptions. Management continually reevaluates the other subjective factors included in its ALLL analysis.
Loans Held for Sale	Loans Held for Sale
Premises and Equipment	Premises and Equipment Depreciation and amortization are computed primarily using the straight-line method. Estimated useful lives range up to 40 years for buildings, 2 to 10 years for furniture, fixtures, and equipment, and up to the lease term for leasehold improvements. Capitalized leased assets are amortized on a straight-line basis over the lives of the respective leases.
Federal Home Loan Bank and Federal Reserve Stock	Federal Home Loan Bank and Federal Reserve Stock CTB is also a member of its regional Federal Reserve Bank. Federal Reserve Bank stock is carried at cost, classified as a restricted security, and periodically evaluated for impairment based on the ultimate recovery par value. Both cash and stock dividends are reported as income.
Other Real Estate Owned	Other Real Estate Owned All revenues and expenses related to the carrying of other real estate owned are recognized through the income statement.
Goodwill and Core Deposit Intangible	Goodwill and Core Deposit Intangible Intangibles-Goodwill and Other The balance of goodwill, at $65.5 million, has not changed since January 1, 2015. The activity to core deposit intangible for the years ended December 31, 2017, 2016, and 2015 is shown below. (in thousands) 2017 2016 2015 Beginning balance, January 1 $ 133 $ 291 $ 477 Amortization (133 ) (158 ) (186 ) Ending balance, December 31 $ 0 $ 133 $ 291 Our core deposit intangible has been fully amortized as of December 31, 2017.
Transfers of Financial Assets	Transfers of Financial Assets
Income Taxes	Income Taxes
Earnings Per Share ("EPS")	Earnings Per Share (“EPS”) Diluted EPS adjusts the number of weighted average shares of common stock outstanding by the dilutive effect of stock options, including restricted shares, as prescribed in ASC 718, Share-Based Payment
Segments	Segments
Bank Owned Life Insurance	Bank Owned Life Insurance
Mortgage Servicing Rights	Mortgage Servicing Rights Servicing Assets and Liabilities Fair Value Measurements
Share-Based Compensation	Share-Based Compensation Share-Based Payment
Comprehensive Income	Comprehensive Income
Transfers between Fair Value Hierarchy Levels	Transfers between Fair Value Hierarchy Levels –
Reclassifications	Reclassifications –
New Accounting Standards	New Accounting Standards Ø Financial Instruments – Overall Financial Instruments – Overall (Subtopic 825-10) Ø Leases – In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) . We have calculated the minimum and maximum net present value of all potential lease payments to be between $10.1 million and $20.3 million. The next step in the analysis will be to determine the renewal periods reasonably expected to be exercised. Ø Investments—Equity Method and Joint Ventures: Simplifying the Transition to the Equity Method of Accounting FASB issued ASU No. 2016-07, Investments - Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting. The amendments affect all entities that have an investment that becomes qualified for the equity method of accounting as a result of an increase in the level of ownership interest or degree of influence. The amendments eliminate the requirement that when an investment qualifies for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investment, results of operations, and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods that the investment had been held. The amendments require that the equity method investor add the cost of acquiring the additional interest in the investee to the current basis of the investor’s previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. Therefore, upon qualifying for the equity method of accounting, no retroactive adjustment of the investment is required. The amendments require that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in accumulated other comprehensive income at the date the investment becomes qualified for use of the equity method. The amendments should be applied prospectively upon their effective date to increases in the level of ownership interest or degree of influence that result in the adoption of the equity method. The amendments became effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016 and did not . Ø Compensation—Stock Compensation: Improvements to Employee Share-Based Payment Accounting FASB issued Accounting Standards Update (ASU) No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The amendments are intended to improve the accounting for employee share-based payments and affect all organizations that issue share-based payment awards to their employees. Several aspects of the accounting for share-based payment award transactions are simplified, including: (a) (b) (c) For public companies, the amendments were effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Ø Revenue from Contracts with Customers – Revenue from Contracts with Customers Ø Accounting for Credit Losses Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. For purchased financial assets with a more-than-insignificant amount of credit deterioration since origination (“PCD assets”) that are measured at amortized cost, the initial allowance for credit losses is added to the purchase price rather than being reported as a credit loss expense. Subsequent changes in the allowance for credit losses on PCD assets are recognized through the statement of income as a credit loss expense. Credit losses relating to available-for-sale debt securities will be recorded through an allowance for credit losses rather than as a direct write-down to the security. ASU 2016-13 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. CTBI has an implementation team working through the provisions of ASU 2016-13 including assessing the impact on its accounting and disclosures. The team has established the historical data that will be available and has identified the potential loan segments to be analyzed. Initial data analysis will begin in the first quarter of 2018. Ø Statement of Cash Flows Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. Stakeholders indicated that there is diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows under Topic 230, Statement of Cash Flows, and other Topics. This ASU addresses the following eight specific cash flow issues: Debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies (COLIs) (including bank-owned life insurance policies (BOLIs)); distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. The amendments in this Update apply to all entities that are required to present a statement of cash flows under Topic 230. This Update is the final version of Proposed Accounting Standards Update EITF-15F— Statement of Cash Flows—Classification of Certain Cash Receipts and Cash Payments (Topic 230) , which has been deleted. The amendments in this Update are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The amendments in this Update should be applied using a retrospective transition method to each period presented. If it is impracticable to apply the amendments retrospectively for some of the issues, the amendments for those issues would be applied prospectively as of the earliest date practicable. We adopted this ASU effective January 1, 2018 with no Ø Simplifying the Test for Goodwill Impairment Intangibles – Goodwill and Other (Topic 350) – Simplifying the Test for Goodwill Impairment Ø Receivables – Nonrefundable Fees and Other Costs: Premium Amortization on Purchased Callable Debt Securities Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities Ø Income Statement—Reporting Comprehensive Income Income Statement—Reporting Comprehensive Income (Topic 220)

Accounting Policies (Tables)

Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Activity to Core Deposit Intangible	The activity to core deposit intangible for the years ended December 31, 2017, 2016, and 2015 is shown below. (in thousands) 2017 2016 2015 Beginning balance, January 1 $ 133 $ 291 $ 477 Amortization (133 ) (158 ) (186 ) Ending balance, December 31 $ 0 $ 133 $ 291

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Securities [Abstract]
Summary of Amortized Cost and Fair Value of Available-for-sale Securities	The amortized cost and fair value of securities at December 31, 2017 are summarized as follows: Available-for-Sale (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury and government agencies $ 211,574 $ 170 $ (1,172 ) $ 210,572 State and political subdivisions 144,159 2,017 (1,161 ) 145,015 U.S. government sponsored agency mortgage-backed securities 208,959 357 (4,007 ) 205,309 Other debt securities 507 0 0 507 Total debt securities 565,199 2,544 (6,340 ) 561,403 CRA investment funds 25,000 76 (718 ) 24,358 Total available-for-sale securities $ 590,199 $ 2,620 $ (7,058 ) $ 585,761 The amortized cost and fair value of securities at December 31, 2016 are summarized as follows: Available-for-Sale (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury and government agencies $ 223,014 $ 193 $ (743 ) $ 222,464 State and political subdivisions 133,351 1,957 (1,792 ) 133,516 U.S. government sponsored agency mortgage-backed securities 227,574 1,008 (3,526 ) 225,056 Other debt securities 0 0 0 0 Total debt securities 583,939 3,158 (6,061 ) 581,036 CRA investment funds 25,000 76 (718 ) 24,358 Total available-for-sale securities $ 608,939 $ 3,234 $ (6,779 ) $ 605,394
Summary of Amortized Cost and Fair Value of Held-to-maturity Securities	The amortized cost and fair value of securities at December 31, 2017 are summarized as follows: Held-to-Maturity (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value State and political subdivisions $ 659 $ 1 $ 0 $ 660 Total held-to-maturity securities $ 659 $ 1 $ 0 $ 660 The amortized cost and fair value of securities at December 31, 2016 are summarized as follows: Held-to-Maturity (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value State and political subdivisions $ 866 $ 1 $ 0 $ 867 Total held-to-maturity securities $ 866 $ 1 $ 0 $ 867
Amortized Cost and Fair Value of Securities by Contractual Maturity	The amortized cost and fair value of securities at December 31, 2017 by contractual maturity are shown below. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Available-for-Sale Held-to-Maturity (in thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 4,288 $ 4,294 $ 0 $ 0 Due after one through five years 163,320 162,977 659 660 Due after five through ten years 43,595 44,022 0 0 Due after ten years 144,530 144,294 0 0 U.S. government sponsored agency mortgage-backed securities 208,959 205,309 0 0 Other debt securities 507 507 0 0 Total debt securities 565,199 561,403 659 660 CRA investment funds 25,000 24,358 0 0 Total securities $ 590,199 $ 585,761 $ 659 $ 660
Available for Sale Securities and Held-to-Maturity Securities, Continuous Unrealized Loss Position	The following tables provide the amortized cost, gross unrealized losses, and fair market value, aggregated by investment category and length of time the individual securities have been in a continuous unrealized loss position as of December 31, 2017 that are not deemed to be other-than-temporarily impaired. There were no held-to-maturity securities that were deemed to be impaired as of December 31, 2017. Available-for-Sale (in thousands) Amortized Cost Gross Unrealized Losses Fair Value Less Than 12 Months U.S. Treasury and government agencies $ 136,688 $ (840 ) $ 135,848 State and political subdivisions 34,283 (416 ) 33,867 U.S. government sponsored agency mortgage-backed securities 62,768 (643 ) 62,125 Other debt securities 0 0 0 Total debt securities 233,739 (1,899 ) 231,840 CRA investment funds 7,500 (105 ) 7,395 Total <12 months temporarily impaired AFS securities 241,239 (2,004 ) 239,235 12 Months or More U.S. Treasury and government agencies 23,885 (332 ) 23,553 State and political subdivisions 16,930 (745 ) 16,185 U.S. government sponsored agency mortgage-backed securities 117,827 (3,364 ) 114,463 Other debt securities 0 0 0 Total debt securities 158,642 (4,441 ) 154,201 CRA investment funds 15,000 (613 ) 14,387 Total ≥12 months temporarily impaired AFS securities 173,642 (5,054 ) 168,588 Total U.S. Treasury and government agencies 160,573 (1,172 ) 159,401 State and political subdivisions 51,213 (1,161 ) 50,052 U.S. government sponsored agency mortgage-backed securities 180,595 (4,007 ) 176,588 Other debt securities 0 0 0 Total debt securities 392,381 (6,340 ) 386,041 CRA investment funds 22,500 (718 ) 21,782 Total temporarily impaired AFS securities $ 414,881 $ (7,058 ) $ 407,823 The following tables provide the amortized cost, gross unrealized losses, and fair market value, aggregated by investment category and length of time the individual securities have been in a continuous unrealized loss position as of December 31, 2016 that are not deemed to be other-than-temporarily impaired. There were no held-to-maturity securities that were deemed to be impaired as of December 31, 2016. Available-for-Sale (in thousands) Amortized Cost Gross Unrealized Losses Fair Value Less Than 12 Months U.S. Treasury and government agencies $ 158,732 $ (716 ) $ 158,016 State and political subdivisions 53,491 (1,780 ) 51,711 U.S. government sponsored agency mortgage-backed securities 135,939 (2,646 ) 133,293 Other debt securities 0 0 0 Total debt securities 348,162 (5,142 ) 343,020 CRA investment funds 17,500 (444 ) 17,056 Total <12 months temporarily impaired AFS securities 365,662 (5,586 ) 360,076 12 Months or More U.S. Treasury and government agencies 1,880 (27 ) 1,853 State and political subdivisions 751 (12 ) 739 U.S. government sponsored agency mortgage-backed securities 31,132 (880 ) 30,252 Other debt securities 0 0 0 Total debt securities 33,763 (919 ) 32,844 CRA investment funds 5,000 (274 ) 4,726 Total ≥12 months temporarily impaired AFS securities 38,763 (1,193 ) 37,570 Total U.S. Treasury and government agencies 160,612 (743 ) 159,869 State and political subdivisions 54,242 (1,792 ) 52,450 U.S. government sponsored agency mortgage-backed securities 167,071 (3,526 ) 163,545 Other debt securities 0 0 0 Total debt securities 381,925 (6,061 ) 375,864 CRA investment funds 22,500 (718 ) 21,782 Total temporarily impaired AFS securities $ 404,425 $ (6,779 ) $ 397,646

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2017
Loans [Abstract]
Summary of Major Classification of Loans Net of Unearned Income, Deferred Loan Origination Costs and Net Premiums on Acquired Loans	Major classifications of loans, net of unearned income, deferred loan origination costs, and net premiums on acquired loans, are summarized as follows: (in thousands) December 31 2017 December 31 2016 Commercial construction $ 76,479 $ 66,998 Commercial secured by real estate 1,188,680 1,085,428 Equipment lease financing 3,042 5,512 Commercial other 351,034 350,159 Real estate construction 67,358 57,966 Real estate mortgage 709,570 702,969 Home equity 99,356 91,511 Consumer direct 137,754 133,093 Consumer indirect 489,667 444,735 Total loans $ 3,122,940 $ 2,938,371
Nonaccrual Loans Segregated by Class of Loans	Nonaccrual loans segregated by class of loans were as follows: (in thousands) December 31 2017 December 31 2016 Commercial: Commercial construction $ 1,207 $ 1,912 Commercial secured by real estate 7,028 6,326 Commercial other 934 1,559 Residential: Real estate construction 318 11 Real estate mortgage 8,243 6,260 Home equity 389 555 Total nonaccrual loans $ 18,119 $ 16,623
Bank's Loan Portfolio Aging Analysis, Segregated by Class	The following tables present CTBI’s loan portfolio aging analysis, segregated by class, as of December 31, 2017 and 2016: December 31, 2017 (in thousands) 30-59 Days Past Due 60-89 Days Past Due 90+ Days Past Due Total Past Due Current Total Loans 90+ and Accruing* Commercial: Commercial construction $ 138 $ 0 $ 1,238 $ 1,376 $ 75,103 $ 76,479 $ 31 Commercial secured by real estate 4,047 1,599 8,514 14,160 1,174,520 1,188,680 2,665 Equipment lease financing 430 0 0 430 2,612 3,042 0 Commercial other 835 77 652 1,564 349,470 351,034 87 Residential: Real estate construction 224 202 223 649 66,709 67,358 223 Real estate mortgage 2,064 5,029 11,605 18,698 690,872 709,570 6,293 Home equity 595 178 428 1,201 98,155 99,356 167 Consumer: Consumer direct 983 148 62 1,193 136,561 137,754 62 Consumer indirect 4,085 1,399 648 6,132 483,535 489,667 648 Total $ 13,401 $ 8,632 $ 23,370 $ 45,403 $ 3,077,537 $ 3,122,940 $ 10,176 December 31, 2016 (in thousands) 30-59 Days Past Due 60-89 Days Past Due 90+ Days Past Due Total Past Due Current Total Loans 90+ and Accruing* Commercial: Commercial construction $ 22 $ 0 $ 1,940 $ 1,962 $ 65,036 $ 66,998 $ 28 Commercial secured by real estate 2,033 478 8,847 11,358 1,074,070 1,085,428 3,015 Equipment lease financing 0 0 0 0 5,512 5,512 0 Commercial other 997 122 1,235 2,354 347,805 350,159 141 Residential: Real estate construction 707 42 152 901 57,065 57,966 152 Real estate mortgage 1,493 5,278 10,695 17,466 685,503 702,969 6,295 Home equity 829 288 905 2,022 89,489 91,511 467 Consumer: Consumer direct 873 265 68 1,206 131,887 133,093 68 Consumer indirect 3,288 851 681 4,820 439,915 444,735 681 Total $ 10,242 $ 7,324 $ 24,523 $ 42,089 $ 2,896,282 $ 2,938,371 $ 10,847 *90+ and Accruing are also included in 90+ Days Past Due column.
Credit Risk Profile of the Bank's Commercial Loan Portfolio Based on Rating Category and Payment Activity, Segregated by Class of Loans	The following tables present the credit risk profile of CTBI’s commercial loan portfolio based on rating category and payment activity, segregated by class of loans, as of December 31, 2017 and 2016: (in thousands) Commercial Construction Commercial Secured by Real Estate Equipment Leases Commercial Other Total December 31, 2017 Pass $ 67,846 $ 1,053,701 $ 3,005 $ 305,655 $ 1,430,207 Watch 3,323 65,182 0 29,008 97,513 OAEM 1,304 22,401 37 3,206 26,948 Substandard 3,828 47,223 0 12,947 63,998 Doubtful 178 173 0 218 569 Total $ 76,479 $ 1,188,680 $ 3,042 $ 351,034 $ 1,619,235 December 31, 2016 Pass $ 55,315 $ 975,383 $ 5,206 $ 299,301 $ 1,335,205 Watch 3,366 51,932 137 32,780 88,215 OAEM 2,535 25,772 169 7,913 36,389 Substandard 5,592 31,945 0 9,599 47,136 Doubtful 190 396 0 566 1,152 Total $ 66,998 $ 1,085,428 $ 5,512 $ 350,159 $ 1,508,097
Credit Risk Profile of Residential Real Estate and Consumer Loan Portfolio Based on Performing and Nonperforming Status Segregated by Class	The following tables present the credit risk profile of CTBI’s residential real estate and consumer loan portfolios based on performing or nonperforming status, segregated by class, as of December 31, 2017 and 2016: (in thousands) Real Estate Construction Real Estate Mortgage Home Equity Consumer Direct Consumer Indirect Total December 31, 2017 Performing $ 66,817 $ 695,034 $ 98,800 $ 137,692 $ 489,019 $ 1,487,362 Nonperforming (1) 541 14,536 556 62 648 16,343 Total $ 67,358 $ 709,570 $ 99,356 $ 137,754 $ 489,667 $ 1,503,705 December 31, 2016 Performing $ 57,803 $ 690,414 $ 90,489 $ 133,025 $ 444,054 $ 1,415,785 Nonperforming (1) 163 12,555 1,022 68 681 14,489 Total $ 57,966 $ 702,969 $ 91,511 $ 133,093 $ 444,735 $ 1,430,274 (1) A loan is considered nonperforming if it is 90 days or more past due or on nonaccrual.
Impaired Loans, Average Investment in Impaired Loans, and Interest Income Recognized on Impaired Loans	The following table presents impaired loans, the average investment in impaired loans, and interest income recognized on impaired loans for the years ended December 31, 2017, 2016, and 2015: December 31, 2017 (in thousands) Recorded Balance Unpaid Contractual Principal Balance Specific Allowance Average Investment in Impaired Loans *Interest Income Recognized Loans without a specific valuation allowance: Commercial construction $ 4,431 $ 4,439 $ 0 $ 4,835 $ 200 Commercial secured by real estate 28,480 30,365 0 27,753 1,344 Equipment lease financing 0 0 0 34 0 Commercial other 9,481 11,252 0 10,444 539 Real estate construction 318 318 0 534 0 Real estate mortgage 1,564 1,570 0 1,591 36 Loans with a specific valuation allowance: Commercial construction 153 173 25 155 0 Commercial secured by real estate 2,985 4,095 966 3,932 8 Commercial other 0 0 0 65 0 Totals: Commercial construction 4,584 4,612 25 4,990 200 Commercial secured by real estate 31,465 34,460 966 31,685 1,352 Equipment lease financing 0 0 0 34 0 Commercial other 9,481 11,252 0 10,509 539 Real estate construction 318 318 0 534 0 Real estate mortgage 1,564 1,570 0 1,591 36 Total $ 47,412 $ 52,212 $ 991 $ 49,343 $ 2,127 December 31, 2016 (in thousands) Recorded Balance Unpaid Contractual Principal Balance Specific Allowance Average Investment in Impaired Loans *Interest Income Recognized Loans without a specific valuation allowance: Commercial construction $ 4,102 $ 4,123 $ 0 $ 4,367 $ 218 Commercial secured by real estate 29,025 29,594 0 31,136 1,609 Equipment lease financing 0 0 0 0 0 Commercial other 11,215 13,155 0 11,561 632 Real estate mortgage 1,483 1,483 0 1,691 52 Loans with a specific valuation allowance: Commercial construction 1,507 1,509 213 2,290 0 Commercial secured by real estate 4,731 5,885 1,035 4,151 19 Commercial other 139 139 65 483 0 Totals: Commercial construction 5,609 5,632 213 6,657 218 Commercial secured by real estate 33,756 35,479 1,035 35,287 1,628 Equipment lease financing 0 0 0 0 0 Commercial other 11,354 13,294 65 12,044 632 Real estate mortgage 1,483 1,483 0 1,691 52 Total $ 52,202 $ 55,888 $ 1,313 $ 55,679 $ 2,530 December 31, 2015 (in thousands) Recorded Balance Unpaid Contractual Principal Balance Specific Allowance Average Investment in Impaired Loans *Interest Income Recognized Loans without a specific valuation allowance: Commercial construction $ 2,861 $ 2,862 $ 0 $ 4,574 $ 200 Commercial secured by real estate 30,761 32,166 0 30,605 1,378 Equipment lease financing 0 0 0 0 0 Commercial other 7,500 9,148 0 8,802 316 Real estate mortgage 1,744 1,744 0 1,179 50 Loans with a specific valuation allowance: Commercial construction 3,402 3,402 831 3,631 0 Commercial secured by real estate 2,660 2,768 1,227 2,349 7 Commercial other 960 1,153 403 836 1 Totals: Commercial construction 6,263 6,264 831 8,205 200 Commercial secured by real estate 33,421 34,934 1,227 32,954 1,385 Equipment lease financing 0 0 0 0 0 Commercial other 8,460 10,301 403 9,638 317 Real estate mortgage 1,744 1,744 0 1,179 50 Total $ 49,888 $ 53,243 $ 2,461 $ 51,976 $ 1,952 *Cash basis interest is substantially the same as interest income recognized.
Troubled Debt Restructurings	Presented below, segregated by class of loans, are troubled debt restructurings that occurred during the years ended December 31, 2017 and 2016: Year Ended December 31, 2017 (in thousands) Number of Loans Term Modification Rate Modification Combination Post-Modification Outstanding Balance Commercial: Commercial construction 2 $ 0 $ 0 $ 114 $ 114 Commercial secured by real estate 15 2,199 0 192 2,391 Commercial other 22 1,072 0 136 1,208 Residential: Real estate construction 1 846 0 0 846 Real estate mortgage 3 988 0 0 988 Total troubled debt restructurings 43 $ 5,105 $ 0 $ 442 $ 5,547 Year Ended December 31, 2016 (in thousands) Number of Loans Term Modification Rate Modification Combination Post-Modification Outstanding Balance Commercial: Commercial construction 1 $ 1,288 $ 0 $ 0 $ 1,288 Commercial secured by real estate 27 8,827 0 581 9,408 Commercial other 14 5,088 0 87 5,175 Residential: Real estate construction 0 0 0 0 0 Real estate mortgage 1 0 0 281 281 Total troubled debt restructurings 43 $ 15,203 $ 0 $ 949 $ 16,152
Summary of Defaulted Restructured Loans	Presented below, segregated by class of loans, are loans that were modified as troubled debt restructurings within the past twelve months which have subsequently defaulted. CTBI considers a loan in default when it is 90 days or more past due or transferred to nonaccrual. (in thousands) Year Ended December 31, 2017 Number of Loans Recorded Balance Commercial: Commercial secured by real estate 0 $ 0 Commercial other 0 0 Residential: Real estate construction 1 846 Real estate mortgage 0 0 Total defaulted restructured loans 1 $ 846 (in thousands) Year Ended December 31, 2016 Number of Loans Recorded Balance Commercial: Commercial secured by real estate 1 $ 67 Commercial other 1 12 Residential: Real estate construction 0 0 Real estate mortgage 0 0 Total defaulted restructured loans 2 $ 79

Mortgage Banking and Servicin36

Mortgage Banking and Servicing Rights (Tables)	12 Months Ended
	Dec. 31, 2017
Mortgage Banking and Servicing Rights [Abstract]
Components of Mortgage Banking Income	The following table presents the components of mortgage banking income: (in thousands) Year Ended December 31 2017 2016 2015 Net gain on sale of mortgage loans held for sale $ 1,232 $ 1,831 $ 1,978 Net loan servicing income (expense) Servicing fees 1,255 1,239 1,197 Late fees 84 78 88 Ancillary fees 239 322 212 Fair value adjustments (361 ) (324 ) (289 ) Net loan servicing income 1,217 1,315 1,208 Mortgage banking income $ 2,449 $ 3,146 $ 3,186
Activity for Capitalized Mortgage Servicing Rights Using Fair Value Method	Activity for capitalized mortgage servicing rights using the fair value method is as follows: (in thousands) 2017 2016 2015 Fair value of MSRs, beginning of period $ 3,433 $ 3,236 $ 2,968 New servicing assets created 412 521 557 Change in fair value during the period due to: Time decay (1) (184 ) (175 ) (168 ) Payoffs (2) (268 ) (313 ) (247 ) Changes in valuation inputs or assumptions (3) 91 164 126 Fair value of MSRs, end of period $ 3,484 $ 3,433 $ 3,236 (1) Represents decrease in value due to regularly scheduled loan principal payments and partial loan paydowns. (2) Represents decrease in value due to loans that paid off during the period. (3) Represents change in value resulting from market-driven changes in interest rates.

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Activity for Related Party Transactions	Activity for related party extensions of credit during 2017 and 2016 is as follows: (in thousands) 2017 2016 Related party extensions of credit, beginning of period $ 27,081 $ 29,224 New loans and advances on lines of credit 522 2,456 Repayments (2,615 ) (4,599 ) Increase (decrease) due to changes in related parties (8,156 ) 0 Related party extensions of credit, end of period $ 16,832 $ 27,081

Allowance for Loan and Lease 38

Allowance for Loan and Lease Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Allowance for Loan and Lease Losses [Abstract]
Activity in Allowance for Loan and Lease Losses	The following tables present the balance in the allowance for loan and lease losses (“ALLL”) and the recorded investment in loans based on portfolio segment and impairment method as of December 31, 2017, 2016, and 2015: 2017 (in thousands) Commercial Construction Commercial Secured by Real Estate Equipment Lease Financing Commercial Other Real Estate Construction Real Estate Mortgage Home Equity Consumer Direct Consumer Indirect Total ALLL Balance, beginning of year $ 884 $ 14,191 $ 42 $ 4,656 $ 629 $ 6,027 $ 774 $ 1,885 $ 6,845 $ 35,933 Provision charged to expense (237 ) 2,281 (24 ) 1,744 31 189 257 418 2,862 7,521 Losses charged off (10 ) (2,038 ) 0 (1,893 ) 0 (615 ) (178 ) (965 ) (5,386 ) (11,085 ) Recoveries 49 75 0 532 0 87 4 525 2,510 3,782 Balance, end of year $ 686 $ 14,509 $ 18 $ 5,039 $ 660 $ 5,688 $ 857 $ 1,863 $ 6,831 $ 36,151 Ending balance: Individually evaluated for impairment $ 25 $ 966 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 991 Collectively evaluated for impairment $ 661 $ 13,543 $ 18 $ 5,039 $ 660 $ 5,688 $ 857 $ 1,863 $ 6,831 $ 35,160 Loans Ending balance: Individually evaluated for impairment $ 4,584 $ 31,465 $ 0 $ 9,481 $ 318 $ 1,564 $ 0 $ 0 $ 0 $ 47,412 Collectively evaluated for impairment $ 71,895 $ 1,157,215 $ 3,042 $ 341,553 $ 67,040 $ 708,006 $ 99,356 $ 137,754 $ 489,667 $ 3,075,528 2016 (in thousands) Commercial Construction Commercial Secured by Real Estate Equipment Lease Financing Commercial Other Real Estate Construction Real Estate Mortgage Home Equity Consumer Direct Consumer Indirect Total ALLL Balance, beginning of year $ 2,199 $ 14,434 $ 79 $ 4,225 $ 550 $ 6,678 $ 839 $ 1,594 $ 5,496 $ 36,094 Provision charged to expense (1,035 ) 1,220 (37 ) 2,128 264 291 (20 ) 912 4,149 7,872 Losses charged off (316 ) (1,641 ) 0 (2,136 ) (192 ) (1,043 ) (54 ) (1,236 ) (5,050 ) (11,668 ) Recoveries 36 178 0 439 7 101 9 615 2,250 3,635 Balance, end of year $ 884 $ 14,191 $ 42 $ 4,656 $ 629 $ 6,027 $ 774 $ 1,885 $ 6,845 $ 35,933 Ending balance: Individually evaluated for impairment $ 213 $ 1,035 $ 0 $ 65 $ 0 $ 0 $ 0 $ 0 $ 0 $ 1,313 Collectively evaluated for impairment $ 671 $ 13,156 $ 42 $ 4,591 $ 629 $ 6,027 $ 774 $ 1,885 $ 6,845 $ 34,620 Loans Ending balance: Individually evaluated for impairment $ 5,609 $ 33,756 $ 0 $ 11,354 $ 0 $ 1,483 $ 0 $ 0 $ 0 $ 52,202 Collectively evaluated for impairment $ 61,389 $ 1,051,672 $ 5,512 $ 338,805 $ 57,966 $ 701,486 $ 91,511 $ 133,093 $ 444,735 $ 2,886,169 2015 (in thousands) Commercial Construction Commercial Secured by Real Estate Equipment Lease Financing Commercial Other Real Estate Construction Real Estate Mortgage Home Equity Consumer Direct Consumer Indirect Total ALLL Balance, beginning of year $ 2,896 $ 13,618 $ 119 $ 4,263 $ 534 $ 6,094 $ 756 $ 1,574 $ 4,593 $ 34,447 Provision charged to expense (707 ) 2,135 (40 ) 1,338 147 1,888 158 891 2,840 8,650 Losses charged off (3 ) (1,379 ) 0 (1,961 ) (135 ) (1,421 ) (129 ) (1,306 ) (3,536 ) (9,870 ) Recoveries 13 60 0 585 4 117 54 435 1,599 2,867 Balance, end of year $ 2,199 $ 14,434 $ 79 $ 4,225 $ 550 $ 6,678 $ 839 $ 1,594 $ 5,496 $ 36,094 Ending balance: Individually evaluated for impairment $ 831 $ 1,227 $ 0 $ 403 $ 0 $ 0 $ 0 $ 0 $ 0 $ 2,461 Collectively evaluated for impairment $ 1,368 $ 13,207 $ 79 $ 3,822 $ 550 $ 6,678 $ 839 $ 1,594 $ 5,496 $ 33,633 Loans Ending balance: Individually evaluated for impairment $ 6,263 $ 33,421 $ 0 $ 8,460 $ 0 $ 1,744 $ 0 $ 0 $ 0 $ 49,888 Collectively evaluated for impairment $ 71,757 $ 1,019,498 $ 8,514 $ 350,438 $ 61,750 $ 706,130 $ 89,450 $ 126,406 $ 390,130 $ 2,824,073

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Premises and Equipment [Abstract]
Schedule of Premises and Equipment	Premises and equipment are summarized as follows: (in thousands) December 31 2017 2016 Land and buildings $ 79,173 $ 78,086 Leasehold improvements 4,894 4,886 Furniture, fixtures, and equipment 38,096 36,831 Construction in progress 80 769 Total premises and equipment 122,243 120,572 Less accumulated depreciation and amortization (75,925 ) (72,632 ) Premises and equipment, net $ 46,318 $ 47,940

Other Real Estate Owned (Tables

Other Real Estate Owned (Tables)	12 Months Ended
	Dec. 31, 2017
Other Real Estate Owned [Abstract]
Activity for Other Real Estate Owned	Activity for other real estate owned was as follows: (in thousands) 2017 2016 Beginning balance of other real estate owned $ 35,856 $ 40,674 New assets acquired 5,382 5,900 Fair value adjustments (3,034 ) (1,214 ) Sale of assets (6,208 ) (9,504 ) Ending balance of other real estate owned $ 31,996 $ 35,856
Major Classifications of Foreclosed Properties	The major classifications of foreclosed properties are shown in the following table: (in thousands) December 31 2017 2016 1-4 family $ 5,908 $ 6,210 Agricultural/farmland 68 93 Construction/land development/other 16,158 20,778 Multifamily 176 270 Non-farm/non-residential 9,686 8,505 Total foreclosed properties $ 31,996 $ 35,856

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Major Classifications of Deposits	Major classifications of deposits are categorized as follows: (in thousands) December 31 2017 2016 Noninterest bearing deposits $ 790,930 $ 767,918 NOW accounts 51,218 45,872 Money market deposits 692,021 649,917 Savings 416,551 404,558 Certificates of deposit and other time deposits of $100,000 or more 759,025 651,882 Certificates of deposit and other time deposits less than $100,000 554,118 561,161 Total deposits $ 3,263,863 $ 3,081,308
Maturities of Certificates of Deposits and Other Time Deposits	Maturities of certificates of deposits and other time deposits are presented below: Maturities by Period at December 31, 2017 (in thousands) Total Within 1 Year 2 Years 3 Years 4 Years 5 Years After 5 Years Certificates of deposit and other time deposits of $100,000 or more $ 759,025 $ 556,382 $ 61,844 $ 79,013 $ 32,611 $ 29,175 $ 0 Certificates of deposit and other time deposits less than $100,000 554,118 455,593 41,147 22,443 20,149 14,673 113 Total maturities $ 1,313,143 $ 1,011,975 $ 102,991 $ 101,456 $ 52,760 $ 43,848 $ 113

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Borrowings [Abstract]
Schedule of Short-term Debt	Short-term debt is categorized as follows: (in thousands) December 31 2017 2016 Repurchase agreements $ 243,814 $ 251,065 Federal funds purchased 7,312 4,816 Total short-term debt $ 251,126 $ 255,881
Schedule of Long-term Debt	Long-term debt is categorized as follows: (in thousands) December 31 2017 2016 Junior subordinated debentures, 3.07%, due 6/1/37 $ 59,341 $ 61,341

Repurchase Agreements (Tables)

Repurchase Agreements (Tables)	12 Months Ended
	Dec. 31, 2017
Repurchase Agreements [Abstract]
Remaining Contractual Maturity of Securities Sold Under Agreements to Repurchase by Class of Collateral Pledged	The remaining contractual maturity of the securities sold under agreements to repurchase by class of collateral pledged included in the accompanying consolidated balance sheets as of December 31, 2017 and December 31, 2016 is presented in the following tables: December 31, 2017 Remaining Contractual Maturity of the Agreements (in thousands) Overnight and Up to 30 days 30-90 days Greater Than Total Repurchase agreements and U.S. Treasury and government agencies $ 24,957 $ 0 $ 16,771 $ 67,867 $ 109,595 State and political subdivisions 62,620 0 567 12,161 75,348 U.S. government sponsored agency mortgage-backed securities 13,360 0 4,662 40,849 58,871 Total $ 100,937 $ 0 $ 22,000 $ 120,877 $ 243,814 December 31, 2016 Remaining Contractual Maturity of the Agreements (in thousands) Overnight and Up to 30 days 30-90 days Greater Than Total Repurchase agreements and U.S. Treasury and government agencies $ 17,249 $ 0 $ 14,349 $ 73,076 $ 104,674 State and political subdivisions 55,354 0 1,998 10,272 67,624 U.S. government sponsored agency mortgage-backed securities 23,386 0 8,003 47,378 78,767 Total $ 95,989 $ 0 $ 24,350 $ 130,726 $ 251,065

Advances from Federal Home Lo44

Advances from Federal Home Loan Bank (Tables)	12 Months Ended
	Dec. 31, 2017
Advances from Federal Home Loan Bank [Abstract]
Schedule of Federal Home Loan Bank Advances	Federal Home Loan Bank advances consisted of the following monthly amortizing borrowings at December 31: (in thousands) 2017 2016 Monthly amortizing $ 845 $ 944 Total FHLB advances $ 845 $ 944
Advances from Federal Home Loan Bank Requiring Monthly Principal Payment Basis	The advances from the FHLB that require monthly principal payments were due for repayment as follows: Principal Payments Due by Period at December 31, 2017 (in thousands) Total Within 1 Year 2 Years 3 Years 4 Years 5 Years After 5 Years Outstanding advances, weighted average interest rate – 1.14% $ 845 $ 411 $ 20 $ 20 $ 20 $ 21 $ 353

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Taxes [Abstract]
Components of Provision for Income Taxes	The components of the provision for income taxes, exclusive of tax effect of unrealized securities gains and losses, are as follows: (in thousands) 2017 2016 2015 Current income tax expense $ 20,108 $ 18,417 $ 18,416 Deferred income tax expense (259 ) 701 115 Effect of Tax Cuts & Jobs Act (benefit) (2,831 ) - - Total income tax expense $ 17,018 $ 19,118 $ 18,531
Reconciliation of Income Tax Expense at Statutory Rate to Actual Income Tax Expense	A reconciliation of income tax expense at the statutory rate to our actual income tax expense is shown below: (in thousands) 2017 2016 2015 Computed at the statutory rate $ 23,979 35.00 % $ 23,262 35.00 % $ 22,737 35.00 % Adjustments resulting from: Tax-exempt interest (1,259 ) (1.84 ) (1,289 ) (1.94 ) (1,275 ) (1.96 ) Housing and new markets credits (2,579 ) (3.76 ) (2,680 ) (4.03 ) (2,692 ) (4.14 ) Dividends received deduction (129 ) (0.19 ) (136 ) (0.20 ) (128 ) (0.20 ) Bank owned life insurance (492 ) (0.72 ) (518 ) (0.78 ) (549 ) (0.84 ) ESOP dividend deduction (319 ) (0.47 ) (313 ) (0.47 ) (298 ) (0.46 ) Stock option exercises and restricted stock vesting (170 ) (0.25 ) - - - - Effect of Tax Cuts & Jobs Act (2,831 ) (4.13 ) - - - - Other, net 818 1.20 792 1.18 736 1.13 Total $ 17,018 24.84 % $ 19,118 28.76 % $ 18,531 28.53 %
Components of Net Deferred Tax Liability	The components of the net deferred tax liability as of December 31 are as follows: (in thousands) 2017 2016 Deferred tax assets: Allowance for loan and lease losses $ 7,592 $ 12,577 Interest on nonperforming loans 560 806 Accrued expenses 442 1,883 Allowance for other real estate owned 1,322 1,898 Limited partnership investments 64 0 Unrealized losses on AFS securities 932 1,241 Other 204 282 Total deferred tax assets 11,116 18,687 Deferred tax liabilities: Depreciation and amortization (12,270 ) (20,287 ) FHLB stock dividends (2,076 ) (3,460 ) Loan fee income (263 ) (536 ) Mortgage servicing rights (732 ) (1,202 ) Capitalized lease obligations (14 ) (65 ) Limited partnership investments 0 (411 ) Other (195 ) (562 ) Total deferred tax liabilities (15,550 ) (26,523 ) Net deferred tax liability $ (4,434 ) $ (7,836 )

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Shares to be Issued and Remaining Shares Available for Future Issuance	The following table provides detail of the number of shares to be issued upon exercise of outstanding stock-based awards and remaining shares available for future issuance under all of CTBI's equity compensation plans as of December 31, 2017: Plan Category (shares in thousands) Number of Shares to Be Issued Upon Exercise Weighted Average Price Shares Available for Future Issuance Equity compensation plans approved by shareholders: Stock options 45 $ 32.26 519 (a) Restricted stock (c) (b) (a) Performance units (d) (b) (a) Stock appreciation rights (“SARs”) (e) (b) (a) Total 519 (a) Under the 2015 Plan, 550,000 shares are authorized for issuance; 33,668 have been issued as of December 31, 2017. In January of 2016, 18,069 restricted stock shares were issued under the terms of the 2015 Plan pursuant to awards granted under the 2006 Plan. Additional shares will not be issued pursuant to awards granted from prior plans. (b) Not applicable (c) The maximum number of shares of restricted stock that may be granted is 550,000 shares, and the maximum that may be granted to a participant during any calendar year is 75,000 shares. (d) No performance units payable in stock had been issued as of December 31, 2017. The maximum payment that can be made pursuant to performance units granted to any one participant in any calendar year shall be $1,000,000. (e) No SARS have been issued. The maximum number of shares with respect to which SARs may be granted to a participant during any calendar year shall be 100,000 shares.
Schedule of Weighted Average Assumptions Used for Estimating Grant-Date Fair Value of Each Option Grant	CTBI uses a Black-Scholes option pricing model with the following weighted average assumptions, which are evaluated and revised as necessary, in estimating the grant-date fair value of each option grant for the year end: 2016 2015 Expected option life (in years) 7.5 7.5 Expected volatility 34.34% 43.11% Expected dividend yield 3.70% 3.72% Risk-free interest rate 1.45% 1.54%
Unrecognized Compensation Cost, Grant-Date Fair Value of Shares Vested, Cash Received from Option Exercises and Actual Tax Benefit Realized for Tax Deductions from Option Exercises	The following table shows the unrecognized compensation cost related to nonvested share-based compensation arrangements granted under the plans at December 31, 2017, 2016, and 2015 and the total grant-date fair value of shares vested, cash received from option exercises under all share-based payment arrangements, and the actual tax benefit realized for the tax deductions from option exercises of the share-based payment arrangements for the years ended December 31, 2017, 2016, and 2015. (in thousands) 2017 2016 2015 Unrecognized compensation cost of unvested share-based compensation arrangements granted under the plan at year-end $ 1,242 $ 835 $ 495 Grant date fair value of shares vested for the year 564 1,490 1,111 Cash received from option exercises under all share-based payment arrangements for the year 693 2,099 1,212 Tax benefit realized for the tax deductions from option exercises of the share-based payment arrangements for the year 138 3 82
2015 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Shares to be Issued and Remaining Shares Available for Future Issuance	The following table details the shares available for future issuance under the 2015 Plan at December 31, 2017. Plan Category Shares Available for Future Issuance Shares available at January 1, 2017 540,131 Stock option issuances 0 Restricted stock issuances (23,668) Forfeitures 2,677 Shares available for future issuance 519,140
Schedule of Stock Option Activity	CTBI’s stock option activity for the 2015 Plan for the years ended December 31, 2017 and 2016 is summarized as follows: December 31 2017 2016 Options Weighted Average Exercise Price Options Weighted Average Exercise Price Outstanding at beginning of year 10,000 $ 33.55 0 $ 0 Granted 0 0 10,000 33.55 Exercised 0 0 0 0 Forfeited/expired 0 0 0 0 Outstanding at end of year 10,000 $ 33.55 10,000 $ 33.55 Exercisable at end of year 0 $ 0 0 $ 0
Summary for Status of Nonvested Options	A summary of the status of CTBI’s 2015 Plan for nonvested options as of December 31, 2017, and changes during the year ended December 31, 2017, is presented as follows: Nonvested Options Options Weighted Average Grant Date Fair Value Nonvested at January 1, 2017 10,000 $ 6.82 Granted 0 0 Vested 0 0 Forfeited 0 0 Nonvested at December 31, 2017 10,000 $ 6.82
Schedule of Intrinsic Values of Options Exercised, Exercisable, and Outstanding	The following table shows the intrinsic values of options exercised, exercisable, and outstanding for the 2015 Plan for the years ended December 31, 2017: (in thousands) 2017 Options exercised $ 0 Options exercisable 0 Outstanding options 136
Schedule of Restricted Stock Activity	The following table shows restricted stock activity for the 2015 Plan for the years ended December 31, 2017 and 2016: December 31 2017 2016 Grants Weighted Average Fair Value at Grant Grants Weighted Average Fair Value at Grant Outstanding at beginning of year 17,496 $ 33.55 0 $ 0 Granted* 23,668 46.45 18,069 33.55 Vested (5,751 ) 35.79 (442 ) 33.55 Forfeited (2,328 ) 41.31 (131 ) 33.55 Outstanding at end of year 33,085 $ 41.84 17,496 $ 33.55 * Grants issued in 2016 were issued under the terms of the 2015 Plan pursuant to awards granted and earned under the 2006 Plan.
2006 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Stock Option Activity	CTBI’s stock option activity for the 2006 Plan for the years ended December 31, 2017, 2016, and 2015 is summarized as follows: December 31 2017 2016 2015 Options Weighted Average Exercise Price Options Weighted Average Exercise Price Options Weighted Average Exercise Price Outstanding at beginning of year 61,041 $ 29.84 118,574 $ 32.36 98,821 $ 32.35 Granted 0 0 0 0 20,000 32.27 Exercised (25,665 ) 27.01 (57,423 ) 35.02 (247 ) 24.12 Forfeited/expired 0 0 (110 ) 35.41 0 0 Outstanding at end of year 35,376 $ 31.90 61,041 $ 29.84 118,574 $ 32.36 Exercisable at end of year 5,376 $ 25.22 30,629 $ 26.64 87,749 $ 32.12
Summary for Status of Nonvested Options	A summary of the status of CTBI’s 2006 Plan for nonvested options as of December 31, 2017, and changes during the year ended December 31, 2017, is presented as follows: Nonvested Options Options Weighted Average Grant Date Fair Value Nonvested at January 1, 2017 30,412 $ 7.00 Granted 0 0 Vested (412 ) 8.23 Forfeited 0 0 Nonvested at December 31, 2017 30,000 $ 6.98
Schedule of Intrinsic Values of Options Exercised, Exercisable, and Outstanding	The following table shows the intrinsic values of options exercised, exercisable, and outstanding for the 2006 Plan for the years ended December 31, 2017, 2016, and 2015: (in thousands) 2017 2016 2015 Options exercised $ 537 $ 139 $ 3 Options exercisable 118 703 275 Outstanding options 538 1,206 334
Schedule of Restricted Stock Activity	The following table shows restricted stock activity for the years ended December 31, 2017, 2016, and 2015: December 31 2017 2016 2015 Grants Weighted Average Fair Value at Grant Grants Weighted Average Fair Value at Grant Grants Weighted Average Fair Value at Grant Outstanding at beginning of year 11,989 $ 32.85 64,735 $ 28.92 101,309 $ 26.19 Granted 0 0 0 0 10,582 32.27 Vested (6,214 ) 32.48 (52,521 ) 28.01 (46,482 ) 23.66 Forfeited (349 ) 33.31 (225 ) 32.52 (674 ) 33.31 Outstanding at end of year 5,426 $ 33.24 11,989 $ 32.85 64,735 $ 28.92
1998 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Stock Option Activity	CTBI’s stock option activity for the 1998 Plan for the years ended December 31, 2016 and 2015 is summarized as follows: December 31 2016 2015 Options Weighted Average Exercise Price Options Weighted Average Exercise Price Outstanding at beginning of year 2,980 $ 29.49 43,960 $ 29.43 Granted 0 0 0 0 Exercised (2,980 ) 29.49 (40,980 ) 29.42 Forfeited/expired 0 0 0 0 Outstanding at end of year 0 $ 0 2,980 $ 29.49 Exercisable at end of year 0 $ 0 2,980 $ 29.49
Schedule of Intrinsic Values of Options Exercised, Exercisable, and Outstanding	The following table shows the intrinsic values of options exercised, exercisable, and outstanding for the 1998 Plan for the years ended December 31, 2016 and 2015: (in thousands) 2016 2015 Options exercised $ 13 $ 241 Options exercisable 0 16 Outstanding options 0 16

Operating Leases (Tables)

Operating Leases (Tables)	12 Months Ended
	Dec. 31, 2017
Operating Leases [Abstract]
Schedule of Minimum Non-Cancellable Rental Payments and Rental Receipts	Minimum non-cancellable rental payments and rental receipts are as follows: (in thousands) Payments Receipts 2018 $ 2,050 $ 574 2019 1,673 411 2020 1,626 351 2021 1,515 235 2022 1,392 100 Thereafter 3,783 145 Total $ 12,039 $ 1,816

Fair Market Value of Financia48

Fair Market Value of Financial Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Market Value of Financial Assets and Liabilities [Abstract]
Fair Value Assets Measured on Recurring Basis	The following tables present the fair value measurements of assets recognized in the accompanying balance sheets measured at fair value on a recurring basis as of December 31, 2017 and December 31, 2016 and indicate the level within the fair value hierarchy of the valuation techniques. (in thousands) Fair Value Measurements at December 31, 2017 Using Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets measured – recurring basis Available-for-sale securities: U.S. Treasury and government agencies $ 210,572 $ 64,598 $ 145,974 $ 0 State and political subdivisions 145,015 0 145,015 0 U.S. government sponsored agenc y mortgage-backed securities 205,309 0 205,309 0 Other debt securities 507 0 507 0 CRA investment funds 24,358 24,358 0 0 Mortgage servicing rights 3,484 0 0 3,484 (in thousands) Fair Value Measurements at December 31, 2016 Using Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets measured – recurring basis Available-for-sale securities: U.S. Treasury and government agencies $ 222,464 $ 44,934 $ 177,530 $ 0 State and political subdivisions 133,516 0 133,516 0 U.S. government sponsored agenc y mortgage-backed securities 225,056 0 225,056 0 Other debt securities 0 0 0 0 CRA investment funds 24,358 24,358 0 0 Mortgage servicing rights 3,433 0 0 3,433
Reconciliation of the Beginning and Ending Balance of Recurring Fair Value Measurements Using Significant Unobservable (Level 3) Inputs	Following is a reconciliation of the beginning and ending balances of recurring fair value measurements recognized in the accompanying balance sheet using significant unobservable (Level 3) inputs: Mortgage Servicing Rights (in thousands) 2017 2016 Beginning balance $ 3,433 $ 3,236 Total recognized gains (losses) Included in net income 91 164 Issues 412 521 Settlements (452 ) (488 ) Ending balance $ 3,484 $ 3,433 Total gains (losses) for the period included in net income attributable to the change in unrealized gains or losses related to assets still held at the reporting date $ 91 $ 164
Realized and Unrealized Gains and Losses for Items Included in Net Income in the Consolidated Statements of Income	Realized and unrealized gains and losses for items reflected in the table above are included in net income in the consolidated statements of income as follows: Noninterest Income (in thousands) 2017 2016 Total losses $ (361 ) $ (324 )
Fair Value Measurements of Recognized Assets Measured on Nonrecurring Basis	The following tables present the fair value measurements of assets recognized in the accompanying balance sheets measured at fair value on a nonrecurring basis as of December 31, 2017 and December 31, 2016 and indicate the level within the fair value hierarchy of the valuation techniques. (in thousands) Fair Value Measurements at December 31, 2017 Using Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets measured – nonrecurring basis Impaired loans (collateral dependent) $ 2,709 $ 0 $ 0 $ 2,709 Other real estate owned 18,951 0 0 18,951 (in thousands) Fair Value Measurements at December 31, 2016 Using Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets measured – nonrecurring basis Impaired loans (collateral dependent) $ 5,506 $ 0 $ 0 $ 5,506 Other real estate owned 4,388 0 0 4,388
Quantitative Information about Unobservable Inputs Used in Recurring and Nonrecurring Level 3 Fair Value Measurements	The following tables present quantitative information about unobservable inputs used in recurring and nonrecurring Level 3 fair value measurements at December 31, 2017 and December 31, 2016. (in thousands) Quantitative Information about Level 3 Fair Value Measurements Fair Value at December 31, 2017 Valuation Technique(s) Unobservable Input Range (Weighted Average) Mortgage servicing rights $ 3,484 Discount cash flows, computer pricing model Constant prepayment rate 7.0% - 45.0% (10.0%) Probability of default 0.0% - 100.0% (3.0%) Discount rate 10.0% - 11.5% (10.1%) Impaired loans (collateral-dependent) $ 2,709 Market comparable properties Marketability discount 1.9% - 89.8% (38.5%) Other real estate owned $ 18,951 Market comparable properties Comparability adjustments 6.0% - 58.6% (15.0%) (in thousands) Quantitative Information about Level 3 Fair Value Measurements Fair Value at December 31, 2016 Valuation Technique(s) Unobservable Input Range (Weighted Average) Mortgage servicing rights $ 3,433 Discount cash flows, computer pricing model Constant prepayment rate 7.0% - 27.0% (9.5%) Probability of default 0.0% - 100.0% (3.0%) Discount rate 10.0% - 11.5% (10.1%) Impaired loans (collateral-dependent) $ 5,506 Market comparable properties Marketability discount 0.0% - 100.0% (33.7%) Other real estate owned $ 4,388 Market comparable properties Comparability adjustments 10.0% - 100.0% (14.9%)
Fair Value of Financial Instruments and Levels within the Fair Value Hierarchy of the Valuation Techniques	The following table presents estimated fair value of CTBI’s financial instruments as of December 31, 2017 and indicates the level within the fair value hierarchy of the valuation techniques. (in thousands) Fair Value Measurements at December 31, 2017 Using Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets: Cash and cash equivalents $ 175,274 $ 175,274 $ 0 $ 0 Certificates of deposit in other banks 9,800 0 9,772 0 Securities available-for-sale 585,761 88,956 496,805 0 Securities held-to-maturity 659 0 660 0 Loans held for sale 1,033 1,060 0 0 Loans, net 3,086,789 0 0 3,092,437 Federal Home Loan Bank stock 17,927 0 17,927 0 Federal Reserve Bank stock 4,887 0 4,887 0 Accrued interest receivable 13,338 0 13,338 0 Mortgage servicing rights 3,484 0 0 3,484 Financial liabilities: Deposits $ 3,263,863 $ 790,930 $ 2,319,278 $ 0 Repurchase agreements 243,814 0 0 243,932 Federal funds purchased 7,312 0 7,312 0 Advances from Federal Home Loan Bank 845 0 841 0 Long-term debt 59,341 0 0 44,166 Accrued interest payable 2,228 0 2,228 0 Unrecognized financial instruments: Letters of credit $ 0 $ 0 $ 0 $ 0 Commitments to extend credit 0 0 0 0 Forward sale commitments 0 0 0 0 The following table presents estimated fair value of CTBI’s financial instruments as of December 31, 2016 and indicates the level within the fair value hierarchy of the valuation techniques. (in thousands) Fair Value Measurements at December 31, 2016 Using Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets: Cash and cash equivalents $ 144,716 $ 144,716 $ 0 $ 0 Certificates of deposit in other banks 980 0 982 0 Securities available-for-sale 605,394 69,292 536,102 0 Securities held-to-maturity 866 0 867 0 Loans held for sale 1,244 1,260 0 0 Loans, net 2,902,438 0 0 2,882,348 Federal Home Loan Bank stock 17,927 0 17,927 0 Federal Reserve Bank stock 4,887 0 4,887 0 Accrued interest receivable 11,922 0 11,922 0 Mortgage servicing rights 3,433 0 0 3,433 Financial liabilities: Deposits $ 3,081,308 $ 767,918 $ 2,321,690 $ 0 Repurchase agreements 251,065 0 0 250,820 Federal funds purchased 4,816 0 4,816 0 Advances from Federal Home Loan Bank 944 0 1,009 0 Long-term debt 61,341 0 0 49,073 Accrued interest payable 1,200 0 1,200 0 Unrecognized financial instruments: Letters of credit $ 0 $ 0 $ 0 $ 0 Commitments to extend credit 0 0 0 0 Forward sale commitments 0 0 0 0

Off-Balance Sheet Transaction49

Off-Balance Sheet Transactions and Guarantees (Tables)	12 Months Ended
	Dec. 31, 2017
Off-Balance Sheet Transactions and Guarantees [Abstract]
Off-Balance Sheet Financial Instruments	At December 31, CTBI had the following off-balance sheet financial instruments, whose approximate contract amounts represent additional credit risk to CTBI: (in thousands) 2017 2016 Standby letters of credit $ 29,308 $ 29,917 Commitments to extend credit 516,731 570,467 Total off-balance sheet financial instruments $ 546,039 $ 600,384

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2017
Regulatory Matters [Abstract]
Capital Amounts and Ratios	Consolidated Capital Ratios Actual For Capital Adequacy Purposes (in thousands) Amount Ratio Amount Ratio As of December 31, 2017: Tier 1 capital (to average assets) $ 525,707 12.89 % $ 163,136 4.00 % Common equity Tier 1 capital (to risk weighted assets) 468,207 15.33 137,438 4.50 Tier 1 capital (to risk weighted assets) 525,707 17.22 183,173 6.00 Total capital (to risk weighted assets) 562,114 18.41 244,265 8.00 As of December 31, 2016: Tier 1 capital (to average assets) $ 496,432 12.75 % $ 155,743 4.00 % Common equity Tier 1 capital (to risk weighted assets) 436,932 15.18 129,525 4.50 Tier 1 capital (to risk weighted assets) 496,432 17.25 172,672 6.00 Total capital (to risk weighted assets) 532,332 18.50 230,198 8.00 Community Trust Bank, Inc.’s Capital Ratios Actual For Capital Adequacy Purposes To Be Well-Capitalized Under Prompt Corrective Action Provision (in thousands) Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017: Tier 1 capital (to average assets) $ 501,537 12.35 % $ 162,441 4.00 % $ 203,051 5.00 % Common equity Tier 1 capital (to risk weighted assets) 501,537 16.46 137,115 4.50 198,055 6.50 Tier 1 capital (to risk weighted assets) 501,537 16.46 182,820 6.00 243,760 8.00 Total capital (to risk weighted assets) 537,944 17.65 243,827 8.00 304,784 10.00 As of December 31, 2016: Tier 1 capital (to average assets) $ 472,615 12.19 % $ 155,083 4.00 % $ 193,854 5.00 % Common equity Tier 1 capital (to risk weighted assets) 472,615 16.46 129,208 4.50 186,634 6.50 Tier 1 capital (to risk weighted assets) 472,615 16.46 172,278 6.00 229,704 8.00 Total capital (to risk weighted assets) 508,515 17.71 229,708 8.00 287,134 10.00

Parent Company Financial Stat51

Parent Company Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2017
Parent Company Financial Statements [Abstract]
Condensed Balance Sheets	Condensed Balance Sheets (in thousands) December 31 2017 2016 Assets: Cash on deposit $ 1,500 $ 1,525 Investment in and advances to subsidiaries 587,575 556,975 Goodwill 4,973 4,973 Premises and equipment, net 250 142 Other assets 200 391 Total assets $ 594,498 $ 564,006 Liabilities and shareholders’ equity: Long-term debt $ 61,341 $ 61,341 Other liabilities 2,458 2,050 Total liabilities 63,799 63,391 Shareholders’ equity 530,699 500,615 Total liabilities and shareholders’ equity $ 594,498 $ 564,006
Condensed Statements of Income and Comprehensive Income	Condensed Statements of Income and Comprehensive Income (in thousands) Year Ended December 31 2017 2016 2015 Income: Dividends from subsidiary banks $ 24,661 $ 20,708 $ 19,808 Other income 904 459 414 Total income 25,565 21,167 20,222 Expenses: Interest expense 1,723 1,417 1,170 Depreciation expense 116 107 130 Other expenses 2,858 2,256 2,465 Total expenses 4,697 3,780 3,765 Income before income taxes and equity in undistributed income of subsidiaries 20,868 17,387 16,457 Income tax benefit (1,445 ) (1,373 ) (1,371 ) Income before equity in undistributed income of subsidiaries 22,313 18,760 17,828 Equity in undistributed income of subsidiaries 29,180 28,586 28,604 Net income $ 51,493 $ 47,346 $ 46,432 Other comprehensive loss: Unrealized holding losses on securities available-for-sale: Unrealized holding losses arising during the period (820 ) (4,578 ) (342 ) Less: Reclassification adjustments for realized gains (losses) included in net income 73 522 (106 ) Tax benefit (312 ) (1,785 ) (83 ) Implementation of ASU 2018-02 (621 ) 0 0 Other comprehensive loss, net of tax (1,202 ) (3,315 ) (153 ) Comprehensive income $ 50,291 $ 44,031 $ 46,279
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows (in thousands) Year Ended December 31 2017 2016 2015 Cash flows from operating activities: Net income $ 51,493 $ 47,346 $ 46,432 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation 116 107 130 Equity in undistributed earnings of subsidiaries (29,180 ) (28,586 ) (28,604 ) Stock-based compensation 636 458 783 Excess tax benefits of stock-based compensation 0 100 104 Gain on debt repurchase (560 ) 0 0 Changes in: Other assets 145 519 240 Other liabilities 412 (90 ) 968 Net cash provided by operating activities 23,062 19,854 20,053 Cash flows from investing activities: Payment for investment in subsidiary (1,440 ) 0 0 Purchase of premises and equipment (179 ) (104 ) (45 ) Net cash used in investing activities (1,619 ) (104 ) (45 ) Cash flows from financing activities: Issuance of common stock 1,513 2,985 2,082 Repurchase of common stock 0 (382 ) (189 ) Excess tax benefits of stock-based compensation 0 (100 ) (104 ) Dividends paid (22,981 ) (22,190 ) (21,330 ) Net cash used in financing activities (21,468 ) (19,687 ) (19,541 ) Net increase (decrease) in cash and cash equivalents (25 ) 63 467 Cash and cash equivalents at beginning of year 1,525 1,462 995 Cash and cash equivalents at end of year $ 1,500 $ 1,525 $ 1,462

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings per Share	The following table sets forth the computation of basic and diluted earnings per share: Year Ended December 31 (in thousands except per share data) 2017 2016 2015 Numerator: Net income $ 51,493 $ 47,346 $ 46,432 Denominator: Basic earnings per share: Weighted average shares 17,631 17,548 17,431 Diluted earnings per share: Dilutive effect of equity grants 22 18 52 Adjusted weighted average shares 17,653 17,566 17,483 Earnings per share: Basic earnings per share $ 2.92 $ 2.70 $ 2.66 Diluted earnings per share 2.92 2.70 2.66

Accumulated Other Comprehensi53

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income [Abstract]
Amounts Reclassified from Accumulated Other Comprehensive Income (AOCI)	Amounts reclassified from accumulated other comprehensive income (AOCI) and the affected line items in the statements of income during the years ended December 31, 2017, 2016, and 2015 were: Amounts Reclassified from AOCI Year Ended December 31 (in thousands) 2017 2016 2015 Affected line item in the statements of income Securities gains (losses) $ 73 $ 522 $ (106 ) Tax expense (benefit) 26 183 (37 ) Total reclassifications out of AOCI $ 47 $ 339 $ (69 )

Accounting Policies (Details)

Accounting Policies (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)PaymentQuarterSegment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Certificates of Deposits in Other Banks [Abstract]
Maturity period of certificates of deposit in other banks			18 months
Loans [Abstract]
Past due period after which loans must be well secured and in the process of collection to continue accruing interest			90 days
Period of current principal and interest payments for reclassifying nonaccrual loans as accruing loans			6 months
Allowance for Loan and Lease Losses [Abstract]
Number of delinquent monthly payments before loan charge off | Payment			5
Current value assessment period for past due loans secured against real estate			90 days
Threshold period past due for initiation of foreclosure proceedings			120 days
Historical loan loss review period | Quarter			12
Goodwill and Core Deposit Intangible [Abstract]
Goodwill			$ 65,490	$ 65,490
Finite-lived Intangible Assets [Roll Forward]
Beginning balance, January 1	$ 0	$ 0	133
Ending balance, December 31			$ 0	$ 133
Segment Reporting [Abstract]
Number of operating segments | Segment			1
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity securities			$ 25,000
Unrealized holding loss on securities			$ (600)
Federal corporate tax rate			35.00%	35.00%	35.00%
Minimum [Member]
Other Real Estate Owned [Abstract]
Typical frequency of periodic reviews			12 months
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net present value of all potential lease payments			$ 10,100
Maximum [Member]
Other Real Estate Owned [Abstract]
Typical frequency of periodic reviews			18 months
Frequency of periodic reviews in general			24 months
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net present value of all potential lease payments			$ 20,300
Plan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Federal corporate tax rate		21.00%
Buildings [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life			40 years
Furniture, Fixtures, and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life			2 years
Furniture, Fixtures, and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life			10 years
Core Deposit Intangible [Member]
Finite-lived Intangible Assets [Roll Forward]
Beginning balance, January 1	0	$ 0	$ 133	$ 291	$ 477
Amortization			(133)	(158)	(186)
Ending balance, December 31			$ 0	$ 133	$ 291
Commercial [Member] | Unsecured Commercial Loan [Member]
Allowance for Loan and Lease Losses [Abstract]
Charge off threshold for loans considered uncollectible			90 days
Consumer [Member] | Closed-End Consumer Loan [Member]
Allowance for Loan and Lease Losses [Abstract]
Charge off threshold for loans considered uncollectible			120 days
ASU 2017-08 [Member] | Forecast [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reduction in retained earnings	(150)
ASU 2017-08 [Member] | Forecast [Member] | Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Quarterly increase in amortization expense	24
ASU 2017-08 [Member] | Forecast [Member] | Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Quarterly increase in amortization expense	$ 30

Cash and Due from Banks and I55

Cash and Due from Banks and Interest Bearing Deposits (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Federal Reserve [Member]
Cash and Cash Equivalents [Line Items]
Balance requirements	$ 73.5	$ 74.1
Cash accounts which exceeded federally insured limits	124.3
US Bank [Member]
Cash and Cash Equivalents [Line Items]
Cash accounts which exceeded federally insured limits	21.3
Fifth Third Bank [Member]
Cash and Cash Equivalents [Line Items]
Cash accounts which exceeded federally insured limits	0.3
Federal Home Loan Bank [Member]
Cash and Cash Equivalents [Line Items]
Cash accounts which exceeded federally insured limits	$ 3.5

Securities, Amortized Cost and

Securities, Amortized Cost and Fair Value of Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Available-for-sale Debt Securities [Abstract]
Amortized cost	$ 565,199	$ 583,939
Gross unrealized gains	2,544	3,158
Gross unrealized losses	(6,340)	(6,061)
Fair value	561,403	581,036
Available-for-sale Equity Securities [Abstract]
Amortized cost	25,000
Securities Available-for-Sale [Abstract]
Amortized cost	590,199	608,939
Gross unrealized gains	2,620	3,234
Gross unrealized losses	(7,058)	(6,779)
Available-for-sale securities	585,761	605,394
Securities Held-to-Maturity [Abstract]
Amortized cost	659	866
Gross unrealized gains	1	1
Gross unrealized losses	0	0
Fair value	660	867
U.S. Treasury and Government Agencies [Member]
Available-for-sale Debt Securities [Abstract]
Amortized cost	211,574	223,014
Gross unrealized gains	170	193
Gross unrealized losses	(1,172)	(743)
Fair value	210,572	222,464
State and Political Subdivisions [Member]
Available-for-sale Debt Securities [Abstract]
Amortized cost	144,159	133,351
Gross unrealized gains	2,017	1,957
Gross unrealized losses	(1,161)	(1,792)
Fair value	145,015	133,516
U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Available-for-sale Debt Securities [Abstract]
Amortized cost	208,959	227,574
Gross unrealized gains	357	1,008
Gross unrealized losses	(4,007)	(3,526)
Fair value	205,309	225,056
Other Debt Securities [Member]
Available-for-sale Debt Securities [Abstract]
Amortized cost	507	0
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair value	507	0
CRA Investments Funds [Member]
Available-for-sale Equity Securities [Abstract]
Amortized cost	25,000	25,000
Gross unrealized gains	76	76
Gross unrealized losses	(718)	(718)
Fair value	24,358	24,358
State and Political Subdivisions [Member]
Securities Held-to-Maturity [Abstract]
Amortized cost	659	866
Gross unrealized gains	1	1
Gross unrealized losses	0	0
Fair value	$ 660	$ 867

Securities, Amortized Cost an57

Securities, Amortized Cost and Fair Value of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Available-for-sale, amortized cost [Abstract]
Due in one year or less	$ 4,288
Due after one through five years	163,320
Due after five through ten years	43,595
Due after ten years	144,530
Amortized cost	565,199	$ 583,939
CRA investment funds	25,000
Amortized cost	590,199	608,939
Available-for-sale, fair value [Abstract]
Due in one year or less	4,294
Due after one through five years	162,977
Due after five through ten years	44,022
Due after ten years	144,294
Total debt securities	561,403	581,036
CRA investment funds	24,358
Total securities	585,761	605,394
Held-to-maturity, amortized cost [Abstract]
Due in one year or less	0
Due after one through five years	659
Due after five through ten years	0
Due after ten years	0
Amortized cost	659	866
CRA investment funds	0
Total securities	659
Held-to-maturity, fair value [Abstract]
Due in one year or less	0
Due after one through five years	660
Due after five through ten years	0
Due after ten years	0
Total debt securities	660	867
CRA investment funds	0
Total securities	660
U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Available-for-sale, amortized cost [Abstract]
Without single maturity date	208,959
Amortized cost	208,959	227,574
Available-for-sale, fair value [Abstract]
Without single maturity date	205,309
Total debt securities	205,309	225,056
Other Debt Obligations [Member]
Available-for-sale, amortized cost [Abstract]
Without single maturity date	507
Amortized cost	507	0
Available-for-sale, fair value [Abstract]
Without single maturity date	507
Total debt securities	507	$ 0
U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Held-to-maturity, amortized cost [Abstract]
Without single maturity date	0
Held-to-maturity, fair value [Abstract]
Without single maturity date	0
Other Debt Obligations [Member]
Held-to-maturity, amortized cost [Abstract]
Without single maturity date	0
Held-to-maturity, fair value [Abstract]
Without single maturity date	$ 0

Securities, Gains (Loss) on Sal

Securities, Gains (Loss) on Sales of Securities, Securities Pledged, and Securities Sold Under Agreements to Repurchase (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Securities [Abstract]
Net gain (loss) realized on sales and calls of AFS securities	$ 73	$ 522	$ (106)
Realized pre-tax gain on sale of securities	278
Pre-tax loss on sale of securities	205
Securities pledged as collateral to secure public deposit and for other purposes	225,700	221,200
Amortized cost of securities sold under agreements to repurchase	$ 296,400	$ 303,500

Securities, Securities in Conti

Securities, Securities in Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Securities [Abstract]
Percentage of total investment with unrealized losses	69.50%	65.60%
Available-for-sale, amortized cost [Abstract]
Less than 12 months	$ 241,239	$ 365,662
12 months or more	173,642	38,763
Total	414,881	404,425
Available-for-sale, gross unrealized losses [Abstract]
Less than 12 months	(2,004)	(5,586)
12 months or more	(5,054)	(1,193)
Total	(7,058)	(6,779)
Available-for-sale, fair value [Abstract]
Less than 12 months	239,235	360,076
12 months or more	168,588	37,570
Total	407,823	397,646
U.S. Treasury and Government Agencies [Member]
Available-for-sale, amortized cost [Abstract]
Less than 12 months	136,688	158,732
12 months or more	23,885	1,880
Total	160,573	160,612
Available-for-sale, gross unrealized losses [Abstract]
Less than 12 months	(840)	(716)
12 months or more	(332)	(27)
Total	(1,172)	(743)
Available-for-sale, fair value [Abstract]
Less than 12 months	135,848	158,016
12 months or more	23,553	1,853
Total	159,401	159,869
State and Political Subdivisions [Member]
Available-for-sale, amortized cost [Abstract]
Less than 12 months	34,283	53,491
12 months or more	16,930	751
Total	51,213	54,242
Available-for-sale, gross unrealized losses [Abstract]
Less than 12 months	(416)	(1,780)
12 months or more	(745)	(12)
Total	(1,161)	(1,792)
Available-for-sale, fair value [Abstract]
Less than 12 months	33,867	51,711
12 months or more	16,185	739
Total	50,052	52,450
U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Available-for-sale, amortized cost [Abstract]
Less than 12 months	62,768	135,939
12 months or more	117,827	31,132
Total	180,595	167,071
Available-for-sale, gross unrealized losses [Abstract]
Less than 12 months	(643)	(2,646)
12 months or more	(3,364)	(880)
Total	(4,007)	(3,526)
Available-for-sale, fair value [Abstract]
Less than 12 months	62,125	133,293
12 months or more	114,463	30,252
Total	176,588	163,545
Other Debt Securities [Member]
Available-for-sale, amortized cost [Abstract]
Less than 12 months	0	0
12 months or more	0	0
Total	0	0
Available-for-sale, gross unrealized losses [Abstract]
Less than 12 months	0	0
12 months or more	0	0
Total	0	0
Available-for-sale, fair value [Abstract]
Less than 12 months	0	0
12 months or more	0	0
Total	0	0
Debt Securities [Member]
Available-for-sale, amortized cost [Abstract]
Less than 12 months	233,739	348,162
12 months or more	158,642	33,763
Total	392,381	381,925
Available-for-sale, gross unrealized losses [Abstract]
Less than 12 months	(1,899)	(5,142)
12 months or more	(4,441)	(919)
Total	(6,340)	(6,061)
Available-for-sale, fair value [Abstract]
Less than 12 months	231,840	343,020
12 months or more	154,201	32,844
Total	386,041	375,864
CRA Investment Funds [Member]
Available-for-sale, amortized cost [Abstract]
Less than 12 months	7,500	17,500
12 months or more	15,000	5,000
Total	22,500	22,500
Available-for-sale, gross unrealized losses [Abstract]
Less than 12 months	(105)	(444)
12 months or more	(613)	(274)
Total	(718)	(718)
Available-for-sale, fair value [Abstract]
Less than 12 months	7,395	17,056
12 months or more	14,387	4,726
Total	$ 21,782	$ 21,782
Severity of impairment in percentage of fair value less than cost	2.90%

Loans, Major Classifications of

Loans, Major Classifications of Loans, Net of Income and Deferred Loan Origination Cost (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Segment	Dec. 31, 2016USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 3,122,940	$ 2,938,371
Number of portfolio segments | Segment	9
Loans held for sale [Abstract]
Loans held for sale	$ 1,033	1,244
Commercial [Member] | Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	76,479	66,998
Commercial [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,188,680	1,085,428
Commercial [Member] | Equipment Lease Financing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,042	5,512
Commercial [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	351,034	350,159
Residential [Member] | Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	67,358	57,966
Residential [Member] | Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	709,570	702,969
Residential [Member] | Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	99,356	91,511
Consumer [Member] | Consumer Direct [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	137,754	133,093
Consumer [Member] | Consumer Indirect [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 489,667	$ 444,735

Loans, Nonaccrual Loans Segrega

Loans, Nonaccrual Loans Segregated by Class of Loans and Loan Portfolio Aging Analysis, Segregated by Class (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		$ 18,119	$ 16,623
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		45,403	42,089
Current		3,077,537	2,896,282
Total Loans		3,122,940	2,938,371
90+ and Accruing	[1]	10,176	10,847
Minimum threshold amount of loans requiring performance bond		500
30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		13,401	10,242
60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		8,632	7,324
90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		$ 23,370	24,523
Equipment Lease Financing [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Financing percentage requested for underwriting loans		100.00%
Commercial [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Loans		$ 1,619,235	1,508,097
Commercial [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		1,207	1,912
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		1,376	1,962
Current		75,103	65,036
Total Loans		76,479	66,998
90+ and Accruing	[1]	31	28
Commercial [Member] | Construction [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		138	22
Commercial [Member] | Construction [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		0	0
Commercial [Member] | Construction [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		1,238	1,940
Commercial [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		7,028	6,326
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		14,160	11,358
Current		1,174,520	1,074,070
Total Loans		1,188,680	1,085,428
90+ and Accruing	[1]	2,665	3,015
Commercial [Member] | Real Estate [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		4,047	2,033
Commercial [Member] | Real Estate [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		1,599	478
Commercial [Member] | Real Estate [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		8,514	8,847
Commercial [Member] | Equipment Lease Financing [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		430	0
Current		2,612	5,512
Total Loans		3,042	5,512
90+ and Accruing	[1]	0	0
Commercial [Member] | Equipment Lease Financing [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		430	0
Commercial [Member] | Equipment Lease Financing [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		0	0
Commercial [Member] | Equipment Lease Financing [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		0	0
Commercial [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		934	1,559
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		1,564	2,354
Current		349,470	347,805
Total Loans		351,034	350,159
90+ and Accruing	[1]	87	141
Commercial [Member] | Other [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		835	997
Commercial [Member] | Other [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		77	122
Commercial [Member] | Other [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		652	1,235
Residential [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		318	11
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		649	901
Current		66,709	57,065
Total Loans		67,358	57,966
90+ and Accruing	[1]	223	152
Residential [Member] | Construction [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		224	707
Residential [Member] | Construction [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		202	42
Residential [Member] | Construction [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		223	152
Residential [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		8,243	6,260
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		18,698	17,466
Current		690,872	685,503
Total Loans		709,570	702,969
90+ and Accruing	[1]	6,293	6,295
Residential [Member] | Real Estate [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		2,064	1,493
Residential [Member] | Real Estate [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		5,029	5,278
Residential [Member] | Real Estate [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		11,605	10,695
Residential [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		389	555
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		1,201	2,022
Current		98,155	89,489
Total Loans		99,356	91,511
90+ and Accruing	[1]	167	467
Residential [Member] | Home Equity [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		595	829
Residential [Member] | Home Equity [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		178	288
Residential [Member] | Home Equity [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		428	905
Consumer [Member] | Consumer Direct [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		1,193	1,206
Current		136,561	131,887
Total Loans		137,754	133,093
90+ and Accruing	[1]	62	68
Consumer [Member] | Consumer Direct [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		983	873
Consumer [Member] | Consumer Direct [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		148	265
Consumer [Member] | Consumer Direct [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		62	68
Consumer [Member] | Consumer Indirect [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		6,132	4,820
Current		483,535	439,915
Total Loans		489,667	444,735
90+ and Accruing	[1]	648	681
Consumer [Member] | Consumer Indirect [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		4,085	3,288
Consumer [Member] | Consumer Indirect [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		1,399	851
Consumer [Member] | Consumer Indirect [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		$ 648	$ 681
[1]	90+ and Accruing are also included in 90+ Days Past Due column.

Loans, Credit Risk Profile Base

Loans, Credit Risk Profile Based on Rating Category and Payment Activity and on Performing and Nonperforming Status, Segregated by Class (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		$ 3,122,940	$ 2,938,371
Consumer mortgage loans secured by real estate properties for which formal foreclosure proceedings are in process		3,700	3,500
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		1,619,235	1,508,097
Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		$ 1,430,207	1,335,205
Commercial [Member] | Pass [Member] | Minimum [Member]
Financing Receivable, Recorded Investment [Line Items]
Review period for loans		12 months
Commercial [Member] | Pass [Member] | Maximum [Member]
Financing Receivable, Recorded Investment [Line Items]
Review period for loans		18 months
Commercial [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		$ 97,513	88,215
Commercial [Member] | OAEM [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		26,948	36,389
Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		63,998	47,136
Commercial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		569	1,152
Commercial [Member] | Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		76,479	66,998
Commercial [Member] | Construction [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		67,846	55,315
Commercial [Member] | Construction [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		3,323	3,366
Commercial [Member] | Construction [Member] | OAEM [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		1,304	2,535
Commercial [Member] | Construction [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		3,828	5,592
Commercial [Member] | Construction [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		178	190
Commercial [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		1,188,680	1,085,428
Commercial [Member] | Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		1,053,701	975,383
Commercial [Member] | Real Estate [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		65,182	51,932
Commercial [Member] | Real Estate [Member] | OAEM [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		22,401	25,772
Commercial [Member] | Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		47,223	31,945
Commercial [Member] | Real Estate [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		173	396
Commercial [Member] | Equipment Lease [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		3,042	5,512
Commercial [Member] | Equipment Lease [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		3,005	5,206
Commercial [Member] | Equipment Lease [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		0	137
Commercial [Member] | Equipment Lease [Member] | OAEM [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		37	169
Commercial [Member] | Equipment Lease [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		0	0
Commercial [Member] | Equipment Lease [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		0	0
Commercial [Member] | Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		351,034	350,159
Commercial [Member] | Other [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		305,655	299,301
Commercial [Member] | Other [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		29,008	32,780
Commercial [Member] | Other [Member] | OAEM [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		3,206	7,913
Commercial [Member] | Other [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		12,947	9,599
Commercial [Member] | Other [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		218	566
Residential [Member] | Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		67,358	57,966
Residential [Member] | Construction [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		66,817	57,803
Residential [Member] | Construction [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile	[1]	541	163
Residential [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		709,570	702,969
Residential [Member] | Real Estate [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		695,034	690,414
Residential [Member] | Real Estate [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile	[1]	14,536	12,555
Residential [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		99,356	91,511
Residential [Member] | Home Equity [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		98,800	90,489
Residential [Member] | Home Equity [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile	[1]	556	1,022
Consumer [Member] | Consumer Direct [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		137,754	133,093
Consumer [Member] | Consumer Direct [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		137,692	133,025
Consumer [Member] | Consumer Direct [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile	[1]	62	68
Consumer [Member] | Consumer Indirect [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		489,667	444,735
Consumer [Member] | Consumer Indirect [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		489,019	444,054
Consumer [Member] | Consumer Indirect [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile	[1]	648	681
Residential and Consumer Portfolio Segments [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		1,503,705	1,430,274
Residential and Consumer Portfolio Segments [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile		1,487,362	1,415,785
Residential and Consumer Portfolio Segments [Member] | Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan portfolio based on credit risk profile	[1]	$ 16,343	$ 14,489
[1]	A loan is considered nonperforming if it is 90 days or more past due and/or on nonaccrual.

Loans, Impaired Loans, Average

Loans, Impaired Loans, Average Investments in Impaired Loans, and Interest Income Recognized on Impaired Loans (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans with a specific valuation allowance [Abstract]
Specific Allowance		$ 991	$ 1,313	$ 2,461
Total impaired loans [Abstract]
Recorded Balance		47,412	52,202	49,888
Unpaid Contractual Principal Balance		52,212	55,888	53,243
Specific Allowance		991	1,313	2,461
Average Investment in Impaired Loans		49,343	55,679	51,976
Interest Income Recognized	[1]	2,127	2,530	1,952
Commercial [Member] | Construction [Member]
Loans without a specific valuation allowance [Abstract]
Recorded Balance		4,431	4,102	2,861
Unpaid Contractual Principal Balance		4,439	4,123	2,862
Average Investment in Impaired Loans		4,835	4,367	4,574
Interest Income Recognized	[1]	200	218	200
Loans with a specific valuation allowance [Abstract]
Recorded Balance		153	1,507	3,402
Unpaid Contractual Principal Balance		173	1,509	3,402
Specific Allowance		25	213	831
Average Investment in Impaired Loans		155	2,290	3,631
Interest Income Recognized	[1]	0	0	0
Total impaired loans [Abstract]
Recorded Balance		4,584	5,609	6,263
Unpaid Contractual Principal Balance		4,612	5,632	6,264
Specific Allowance		25	213	831
Average Investment in Impaired Loans		4,990	6,657	8,205
Interest Income Recognized	[1]	200	218	200
Commercial [Member] | Real Estate [Member]
Loans without a specific valuation allowance [Abstract]
Recorded Balance		28,480	29,025	30,761
Unpaid Contractual Principal Balance		30,365	29,594	32,166
Average Investment in Impaired Loans		27,753	31,136	30,605
Interest Income Recognized	[1]	1,344	1,609	1,378
Loans with a specific valuation allowance [Abstract]
Recorded Balance		2,985	4,731	2,660
Unpaid Contractual Principal Balance		4,095	5,885	2,768
Specific Allowance		966	1,035	1,227
Average Investment in Impaired Loans		3,932	4,151	2,349
Interest Income Recognized	[1]	8	19	7
Total impaired loans [Abstract]
Recorded Balance		31,465	33,756	33,421
Unpaid Contractual Principal Balance		34,460	35,479	34,934
Specific Allowance		966	1,035	1,227
Average Investment in Impaired Loans		31,685	35,287	32,954
Interest Income Recognized	[1]	1,352	1,628	1,385
Commercial [Member] | Equipment Lease Financing [Member]
Loans without a specific valuation allowance [Abstract]
Recorded Balance		0	0	0
Unpaid Contractual Principal Balance		0	0	0
Average Investment in Impaired Loans		34	0	0
Interest Income Recognized	[1]	0	0	0
Loans with a specific valuation allowance [Abstract]
Specific Allowance		0	0	0
Total impaired loans [Abstract]
Recorded Balance		0	0	0
Unpaid Contractual Principal Balance		0	0	0
Specific Allowance		0	0	0
Average Investment in Impaired Loans		34	0	0
Interest Income Recognized	[1]	0	0	0
Commercial [Member] | Other [Member]
Loans without a specific valuation allowance [Abstract]
Recorded Balance		9,481	11,215	7,500
Unpaid Contractual Principal Balance		11,252	13,155	9,148
Average Investment in Impaired Loans		10,444	11,561	8,802
Interest Income Recognized	[1]	539	632	316
Loans with a specific valuation allowance [Abstract]
Recorded Balance		0	139	960
Unpaid Contractual Principal Balance		0	139	1,153
Specific Allowance		0	65	403
Average Investment in Impaired Loans		65	483	836
Interest Income Recognized	[1]	0	0	1
Total impaired loans [Abstract]
Recorded Balance		9,481	11,354	8,460
Unpaid Contractual Principal Balance		11,252	13,294	10,301
Specific Allowance		0	65	403
Average Investment in Impaired Loans		10,509	12,044	9,638
Interest Income Recognized	[1]	539	632	317
Residential [Member] | Construction [Member]
Loans without a specific valuation allowance [Abstract]
Recorded Balance		318
Unpaid Contractual Principal Balance		318
Average Investment in Impaired Loans		534
Interest Income Recognized	[1]	0
Loans with a specific valuation allowance [Abstract]
Specific Allowance		0
Total impaired loans [Abstract]
Recorded Balance		318
Unpaid Contractual Principal Balance		318
Specific Allowance		0
Average Investment in Impaired Loans		534
Interest Income Recognized	[1]	0
Residential [Member] | Real Estate [Member]
Loans without a specific valuation allowance [Abstract]
Recorded Balance		1,564	1,483	1,744
Unpaid Contractual Principal Balance		1,570	1,483	1,744
Average Investment in Impaired Loans		1,591	1,691	1,179
Interest Income Recognized	[1]	36	52	50
Loans with a specific valuation allowance [Abstract]
Specific Allowance		0	0	0
Total impaired loans [Abstract]
Recorded Balance		1,564	1,483	1,744
Unpaid Contractual Principal Balance		1,570	1,483	1,744
Specific Allowance		0	0	0
Average Investment in Impaired Loans		1,591	1,691	1,179
Interest Income Recognized	[1]	$ 36	$ 52	$ 50
[1]	Cash basis interest is substantially the same as interest income recognized.

Loans, Troubled Debt Restructur

Loans, Troubled Debt Restructurings Segregated by Class (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Loan	Dec. 31, 2016USD ($)Loan
Financing Receivable, Modifications [Line Items]
Number of Loans | Loan	43	43
Post-Modification Outstanding Balance	$ 5,547	$ 16,152
Commitment to extend additional credit on loans modified in TDRs	$ 200
Defaulted restructured loans, number of loans | Loan	1	2
Defaulted restructured loans, recorded balance	$ 846	$ 79
Term Modification [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	5,105	15,203
Rate Modification [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	0	0
Combination [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	$ 442	$ 949
Commercial [Member] | Construction [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | Loan	2	1
Post-Modification Outstanding Balance	$ 114	$ 1,288
Commercial [Member] | Construction [Member] | Term Modification [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	0	1,288
Commercial [Member] | Construction [Member] | Rate Modification [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	0	0
Commercial [Member] | Construction [Member] | Combination [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	$ 114	$ 0
Commercial [Member] | Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | Loan	15	27
Post-Modification Outstanding Balance	$ 2,391	$ 9,408
Defaulted restructured loans, number of loans | Loan	0	1
Defaulted restructured loans, recorded balance	$ 0	$ 67
Commercial [Member] | Real Estate [Member] | Term Modification [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	2,199	8,827
Commercial [Member] | Real Estate [Member] | Rate Modification [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	0	0
Commercial [Member] | Real Estate [Member] | Combination [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	$ 192	$ 581
Commercial [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | Loan	22	14
Post-Modification Outstanding Balance	$ 1,208	$ 5,175
Defaulted restructured loans, number of loans | Loan	0	1
Defaulted restructured loans, recorded balance	$ 0	$ 12
Commercial [Member] | Other [Member] | Term Modification [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	1,072	5,088
Commercial [Member] | Other [Member] | Rate Modification [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	0	0
Commercial [Member] | Other [Member] | Combination [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	$ 136	$ 87
Residential [Member] | Construction [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | Loan	1	0
Post-Modification Outstanding Balance	$ 846	$ 0
Defaulted restructured loans, number of loans | Loan	1	0
Defaulted restructured loans, recorded balance	$ 846	$ 0
Residential [Member] | Construction [Member] | Term Modification [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	846	0
Residential [Member] | Construction [Member] | Rate Modification [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	0	0
Residential [Member] | Construction [Member] | Combination [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	$ 0	$ 0
Residential [Member] | Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | Loan	3	1
Post-Modification Outstanding Balance	$ 988	$ 281
Defaulted restructured loans, number of loans | Loan	0	0
Defaulted restructured loans, recorded balance	$ 0	$ 0
Residential [Member] | Real Estate [Member] | Term Modification [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	988	0
Residential [Member] | Real Estate [Member] | Rate Modification [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	0	0
Residential [Member] | Real Estate [Member] | Combination [Member]
Financing Receivable, Modifications [Line Items]
Post-Modification Outstanding Balance	$ 0	$ 281

Mortgage Banking and Servicin65

Mortgage Banking and Servicing Rights (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Mortgage Banking and Servicing Rights [Abstract]
Net gain on sale of mortgage loans held for sale		$ 1,232	$ 1,831	$ 1,978
Net loan servicing income (expense) [Abstract]
Servicing fees		1,255	1,239	1,197
Late fees		84	78	88
Ancillary fees		239	322	212
Fair value adjustments		(361)	(324)	(289)
Net loan servicing income		1,217	1,315	1,208
Mortgage banking income		2,449	3,146	3,186
Loan service for benefit of others		462,000	466,000	458,000
Custodial escrow balance		1,000	1,000	1,000
Activity for capitalized mortgage servicing rights using fair value method [Roll Forward]
Fair value of MSRs, beginning of period		3,433	3,236	2,968
New servicing assets created		412	521	557
Change in fair value during the period due to [Abstract]
Time decay	[1]	(184)	(175)	(168)
Payoffs	[2]	(268)	(313)	(247)
Changes in valuation inputs or assumptions	[3]	91	164	126
Fair value of MSRs, end of period		$ 3,484	$ 3,433	$ 3,236
Discount rate of servicing assets and servicing liabilities		10.10%	10.10%	10.10%
Weighted average default rates		3.03%	3.02%	2.64%
Prepayment speeds generated using Andrew Davidson Prepayment Model		10.00%	9.50%	10.00%
[1]	Represents decrease in value due to regularly scheduled loan principal payments and partial loan paydowns.
[2]	Represents decrease in value due to loans that paid off during the period.
[3]	Represents change in value resulting from market-driven changes in interest rates.

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans and Leases Receivable, Related Parties [Roll Forward]
Related party extensions of credit, beginning of period	$ 27,081	$ 29,224
New loans and advances on lines of credit	522	2,456
Repayments	(2,615)	(4,599)
Increase (decrease) due to changes in related parties	(8,156)	0
Related party extensions of credit, end of period	16,832	27,081	$ 29,224
Related Party Transaction [Line Items]
Related party deposit	15,800	15,500
Legal fees	1,668	1,906	2,236
Director Who is Shareholder in Law Firm [Member] | Law Firm [Member]
Related Party Transaction [Line Items]
Legal fees	1,100	1,000	1,200
Expenses	100	100	100
Total payment to related party	$ 1,200	$ 1,100	$ 1,300

Allowance for Loan and Lease 67

Allowance for Loan and Lease Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for loan losses [Roll Forward]
Beginning balance	$ 35,933	$ 36,094	$ 34,447
Provision charged to expense	7,521	7,872	8,650
Losses charged off	(11,085)	(11,668)	(9,870)
Recoveries	3,782	3,635	2,867
Ending balance	36,151	35,933	36,094
Allowance for loan losses ending balance [Abstract]
Individually evaluated for impairment	991	1,313	2,461
Collectively evaluated for impairment	35,160	34,620	33,633
Loans ending balance [Abstract]
Individually evaluated for impairment	47,412	52,202	49,888
Collectively evaluated for impairment	3,075,528	2,886,169	2,824,073
Commercial [Member] | Construction [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	884	2,199	2,896
Provision charged to expense	(237)	(1,035)	(707)
Losses charged off	(10)	(316)	(3)
Recoveries	49	36	13
Ending balance	686	884	2,199
Allowance for loan losses ending balance [Abstract]
Individually evaluated for impairment	25	213	831
Collectively evaluated for impairment	661	671	1,368
Loans ending balance [Abstract]
Individually evaluated for impairment	4,584	5,609	6,263
Collectively evaluated for impairment	71,895	61,389	71,757
Commercial [Member] | Real Estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	14,191	14,434	13,618
Provision charged to expense	2,281	1,220	2,135
Losses charged off	(2,038)	(1,641)	(1,379)
Recoveries	75	178	60
Ending balance	14,509	14,191	14,434
Allowance for loan losses ending balance [Abstract]
Individually evaluated for impairment	966	1,035	1,227
Collectively evaluated for impairment	13,543	13,156	13,207
Loans ending balance [Abstract]
Individually evaluated for impairment	31,465	33,756	33,421
Collectively evaluated for impairment	1,157,215	1,051,672	1,019,498
Commercial [Member] | Equipment Lease Financing [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	42	79	119
Provision charged to expense	(24)	(37)	(40)
Losses charged off	0	0	0
Recoveries	0	0	0
Ending balance	18	42	79
Allowance for loan losses ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	18	42	79
Loans ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	3,042	5,512	8,514
Commercial [Member] | Other [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	4,656	4,225	4,263
Provision charged to expense	1,744	2,128	1,338
Losses charged off	(1,893)	(2,136)	(1,961)
Recoveries	532	439	585
Ending balance	5,039	4,656	4,225
Allowance for loan losses ending balance [Abstract]
Individually evaluated for impairment	0	65	403
Collectively evaluated for impairment	5,039	4,591	3,822
Loans ending balance [Abstract]
Individually evaluated for impairment	9,481	11,354	8,460
Collectively evaluated for impairment	341,553	338,805	350,438
Residential [Member] | Construction [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	629	550	534
Provision charged to expense	31	264	147
Losses charged off	0	(192)	(135)
Recoveries	0	7	4
Ending balance	660	629	550
Allowance for loan losses ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	660	629	550
Loans ending balance [Abstract]
Individually evaluated for impairment	318	0	0
Collectively evaluated for impairment	67,040	57,966	61,750
Residential [Member] | Real Estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	6,027	6,678	6,094
Provision charged to expense	189	291	1,888
Losses charged off	(615)	(1,043)	(1,421)
Recoveries	87	101	117
Ending balance	5,688	6,027	6,678
Allowance for loan losses ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	5,688	6,027	6,678
Loans ending balance [Abstract]
Individually evaluated for impairment	1,564	1,483	1,744
Collectively evaluated for impairment	708,006	701,486	706,130
Residential [Member] | Home Equity [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	774	839	756
Provision charged to expense	257	(20)	158
Losses charged off	(178)	(54)	(129)
Recoveries	4	9	54
Ending balance	857	774	839
Allowance for loan losses ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	857	774	839
Loans ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	99,356	91,511	89,450
Consumer [Member] | Consumer Direct [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	1,885	1,594	1,574
Provision charged to expense	418	912	891
Losses charged off	(965)	(1,236)	(1,306)
Recoveries	525	615	435
Ending balance	1,863	1,885	1,594
Allowance for loan losses ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	1,863	1,885	1,594
Loans ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	137,754	133,093	126,406
Consumer [Member] | Consumer Indirect [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	6,845	5,496	4,593
Provision charged to expense	2,862	4,149	2,840
Losses charged off	(5,386)	(5,050)	(3,536)
Recoveries	2,510	2,250	1,599
Ending balance	6,831	6,845	5,496
Allowance for loan losses ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	6,831	6,845	5,496
Loans ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	$ 489,667	$ 444,735	$ 390,130

Premises and Equipment (Details

Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment, Net, by Type [Abstract]
Premises and equipment, gross	$ 122,243	$ 120,572
Less accumulated depreciation and amortization	(75,925)	(72,632)
Premises and equipment, net	46,318	47,940
Depreciation and amortization of premises and equipment	3,900	3,700	$ 3,700
Land and Buildings [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Premises and equipment, gross	79,173	78,086
Leasehold Improvements [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Premises and equipment, gross	4,894	4,886
Furniture, Fixtures, and Equipment [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Premises and equipment, gross	38,096	36,831
Construction in Progress [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Premises and equipment, gross	$ 80	$ 769

Other Real Estate Owned (Detail

Other Real Estate Owned (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Activity for other real estate owned [Roll Forward]
Beginning balance of other real estate owned	$ 35,856	$ 40,674
New assets acquired	5,382	5,900
Fair value adjustments	(3,034)	(1,214)	$ (1,656)
Sale of assets	(6,208)	(9,504)
Ending balance of other real estate owned	31,996	35,856	40,674
Carrying cost and fair value adjustments for foreclosed properties	4,500	$ 2,900	$ 3,500
Disposal of property not acquired through foreclosure	$ 100

Other Real Estate Owned, Major

Other Real Estate Owned, Major Classifications of Foreclosed Properties (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Foreclosed Properties [Line Items]
Total foreclosed properties	$ 31,996	$ 35,856
1-4 Family [Member]
Schedule of Foreclosed Properties [Line Items]
Total foreclosed properties	5,908	6,210
Agricultural/Farmland [Member]
Schedule of Foreclosed Properties [Line Items]
Total foreclosed properties	68	93
Construction/Land Development/Other [Member]
Schedule of Foreclosed Properties [Line Items]
Total foreclosed properties	16,158	20,778
Multifamily [Member]
Schedule of Foreclosed Properties [Line Items]
Total foreclosed properties	176	270
Non-farm/Non-residential [Member]
Schedule of Foreclosed Properties [Line Items]
Total foreclosed properties	$ 9,686	$ 8,505

Deposits (Details)

Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deposits [Abstract]
Noninterest bearing deposits	$ 790,930	$ 767,918
NOW accounts	51,218	45,872
Money market deposits	692,021	649,917
Savings	416,551	404,558
Certificates of deposit and other time deposits of $100,000 or more	759,025	651,882
Certificates of deposit and other time deposits less than $100,000	554,118	561,161
Total deposits	3,263,863	3,081,308
Certificates of deposit and other time deposits of $250,000 or more	232,500	228,600
Wholesale brokered deposits	82,300	$ 0
Maturities of Time Deposits [Abstract]
Total	1,313,143
Within 1 Year	1,011,975
2 Years	102,991
3 Years	101,456
4 Years	52,760
5 Years	43,848
After 5 Years	113
Certificates of Deposit and Other Time Deposits of $100,000 or More [Member]
Maturities of Time Deposits [Abstract]
Total	759,025
Within 1 Year	556,382
2 Years	61,844
3 Years	79,013
4 Years	32,611
5 Years	29,175
After 5 Years	0
Certificates of Deposit and Other Time Deposits Less Than $100,000 [Member]
Maturities of Time Deposits [Abstract]
Total	554,118
Within 1 Year	455,593
2 Years	41,147
3 Years	22,443
4 Years	20,149
5 Years	14,673
After 5 Years	$ 113

Borrowings, Short-term Debt (De

Borrowings, Short-term Debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Repurchase agreements	$ 243,814	$ 251,065
Federal funds purchased	7,312	4,816
Total short-term debt	$ 251,126	$ 255,881
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Average interest rate	1.30%
Repurchase Agreements [Member]
Short-term Debt [Line Items]
Average interest rate	1.01%
Maximum balance for repurchase agreements at any month-end	$ 260,000
Average balance of repurchase agreements	$ 251,000

Borrowings, Line of Credit Faci

Borrowings, Line of Credit Facility (Details) - Revolving Credit Promissory Note [Member] $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Line of Credit Facility [Line Items]
Maximum borrowing capacity under line of credit	$ 12
Unused commitment fee	0.30%
Remaining borrowing capacity available for general corporate purposes	$ 12
Maturity date of line of credit	Nov. 30, 2018
LIBOR Rate [Member]
Line of Credit Facility [Line Items]
Term of variable rate	1 month
Basis spread on variable rate	2.00%
Description of variable rate basis	one-month LIBOR

Borrowings, Long-term Debt (Det

Borrowings, Long-term Debt (Details) - USD ($) $ in Thousands	Nov. 29, 2017	Apr. 02, 2007	Mar. 30, 2007	May 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Long-term debt [Abstract]
Debt instrument, purchase price					$ 1,440	$ 0	$ 0
Gain on repurchase of debt instrument					560	0	$ 0
Junior Subordinated Debentures [Member]
Long-term debt [Abstract]
Issuance of debt			$ 61,341
Long-term debt					$ 59,341	$ 61,341
Interest rate on junior subordinated debentures	3.07%		6.52%
Maturity date of junior subordinated debentures					Jun. 1, 2037
Maturity period of debentures					30 years
Period after which debentures are redeemable					5 years
Repayment of debt		$ 61,341
Debt instrument, repurchased face amount				$ 2,000
Debt instrument, purchase price				1,440
Gain on repurchase of debt instrument				$ 560
Junior Subordinated Debentures [Member] | LIBOR Rate [Member]
Long-term debt [Abstract]
Term of variable rate					3 months
Description of variable rate basis					three-month LIBOR
Basis spread on variable rate	1.59%		1.59%
Reference rate	1.48%
Junior Subordinated Debentures [Member] | Subordinated Debentures 9.0% [Member]
Long-term debt [Abstract]
Interest rate on junior subordinated debentures		9.00%
Junior Subordinated Debentures [Member] | Subordinated Debentures 8.25% [Member]
Long-term debt [Abstract]
Interest rate on junior subordinated debentures		8.25%
Unconsolidated Delaware Statutory Trust Subsidiary [Member]
Long-term debt [Abstract]
Issuance of capital securities in a private placement			$ 59,500

Repurchase Agreements (Details)

Repurchase Agreements (Details) - Securities Sold under Agreements to Repurchase [Member] - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Carrying value of investment securities available for sale pledged as collateral under repurchase agreements	$ 295,400	$ 302,300
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	243,814	251,065
Overnight and Continuous [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	100,937	95,989
Up to 30 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	0	0
30-90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	22,000	24,350
Greater Than 90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	120,877	130,726
U.S. Treasury and Government Agencies [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	109,595	104,674
U.S. Treasury and Government Agencies [Member] | Overnight and Continuous [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	24,957	17,249
U.S. Treasury and Government Agencies [Member] | Up to 30 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	0	0
U.S. Treasury and Government Agencies [Member] | 30-90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	16,771	14,349
U.S. Treasury and Government Agencies [Member] | Greater Than 90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	67,867	73,076
State and Political Subdivisions [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	75,348	67,624
State and Political Subdivisions [Member] | Overnight and Continuous [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	62,620	55,354
State and Political Subdivisions [Member] | Up to 30 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	0	0
State and Political Subdivisions [Member] | 30-90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	567	1,998
State and Political Subdivisions [Member] | Greater Than 90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	12,161	10,272
U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	58,871	78,767
U.S. Government Sponsored Agency Mortgage-backed Securities [Member] | Overnight and Continuous [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	13,360	23,386
U.S. Government Sponsored Agency Mortgage-backed Securities [Member] | Up to 30 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	0	0
U.S. Government Sponsored Agency Mortgage-backed Securities [Member] | 30-90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	4,662	8,003
U.S. Government Sponsored Agency Mortgage-backed Securities [Member] | Greater Than 90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	$ 40,849	$ 47,378

Advances from Federal Home Lo76

Advances from Federal Home Loan Bank (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Bank, Advances [Line Items]
Total FHLB advances	$ 845	$ 944
Monthly Amortizing Advances [Member]
Federal Home Loan Bank, Advances [Line Items]
Total FHLB advances	845	$ 944
Within 1 Year	411
2 Years	20
3 Years	20
4 Years	20
5 Years	21
After 5 Years	353
Federal Home Loan Bank Advances [Member]
Federal Home Loan Bank, Advances [Line Items]
Federal home loan bank stock used as collateral for advances	17,900
FHLB maximum borrowing capacity	547,800
Federal home loan bank letters of credit used for public fund pledging	251,500
Federal home loan bank advances available	$ 295,500
Federal Home Loan Bank Advances [Member] | Minimum [Member]
Federal Home Loan Bank, Advances [Line Items]
Federal home loan bank advances, interest rate	0.00%
Federal Home Loan Bank Advances [Member] | Maximum [Member]
Federal Home Loan Bank, Advances [Line Items]
Federal home loan bank advances, interest rate	4.85%
Federal Home Loan Bank Advances [Member] | Weighted Average [Member]
Federal Home Loan Bank, Advances [Line Items]
Federal home loan bank advances, interest rate	1.14%
Federal Home Loan Bank Advances [Member] | Monthly Amortizing Advances [Member] | Weighted Average [Member]
Federal Home Loan Bank, Advances [Line Items]
Federal home loan bank advances, interest rate	1.14%	1.33%

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of the provision for income taxes [Abstract]
Current income tax expense		$ 20,108	$ 18,417	$ 18,416
Deferred income tax expense		(259)	701	115
Effect of Tax Cuts & Jobs Act (benefit)		(2,831)	0	0
Total income tax expense		$ 17,018	$ 19,118	$ 18,531
Federal corporate tax rate		35.00%	35.00%	35.00%
Reconciliation of income tax expense at the statutory rate to actual income tax expense [Abstract]
Computed at the statutory rate		$ 23,979	$ 23,262	$ 22,737
Adjustments resulting from [Abstract]
Tax-exempt interest		(1,259)	(1,289)	(1,275)
Housing and new markets credits		(2,579)	(2,680)	(2,692)
Dividends received deduction		(129)	(136)	(128)
Bank owned life insurance		(492)	(518)	(549)
ESOP dividend deduction		(319)	(313)	(298)
Stock option exercises and restricted stock vesting		(170)	0	0
Effect of Tax Cuts & Jobs Act (benefit)		(2,831)	0	0
Other, net		818	792	736
Total income tax expense		$ 17,018	$ 19,118	$ 18,531
Reconciliation of income tax expense at the statutory rate to actual income tax expense [Abstract]
Computed at the statutory rate		35.00%	35.00%	35.00%
Adjustment resulting from [Abstract]
Tax-exempt interest		(1.84%)	(1.94%)	(1.96%)
Housing and new markets credits		(3.76%)	(4.03%)	(4.14%)
Dividends received deduction		(0.19%)	(0.20%)	(0.20%)
Bank owned life insurance		(0.72%)	(0.78%)	(0.84%)
ESOP dividend deduction		(0.47%)	(0.47%)	(0.46%)
Stock option exercises and restricted stock vesting		(0.25%)	0.00%	0.00%
Effect of Tax Cuts & Jobs Act		(4.13%)	0.00%	0.00%
Other, net		1.20%	1.18%	1.13%
Total		24.84%	28.76%	28.53%
Deferred tax assets [Abstract]
Allowance for loan and lease losses		$ 7,592	$ 12,577
Interest on nonperforming loans		560	806
Accrued expenses		442	1,883
Allowance for other real estate owned		1,322	1,898
Limited partnership investments		64	0
Unrealized losses on AFS securities		932	1,241
Other		204	282
Total deferred tax assets		11,116	18,687
Deferred tax liabilities [Abstract]
Depreciation and amortization		(12,270)	(20,287)
FHLB stock dividends		(2,076)	(3,460)
Loan fee income		(263)	(536)
Mortgage servicing rights		(732)	(1,202)
Capitalized lease obligations		(14)	(65)
Limited partnership investments		0	(411)
Other		(195)	(562)
Total deferred tax liabilities		(15,550)	(26,523)
Net deferred tax liability		$ (4,434)	$ (7,836)
Plan [Member]
Components of the provision for income taxes [Abstract]
Federal corporate tax rate	21.00%
Reconciliation of income tax expense at the statutory rate to actual income tax expense [Abstract]
Computed at the statutory rate	21.00%

Employee Benefits (Details)

Employee Benefits (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)Planhshares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)shares
Employee Benefits [Abstract]
Number of retirement savings plan | Plan	2
401(k) Plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Minimum age of employees to participate in plan	21 years
Minimum requisite service period to participate in retirement plans	1 year
Minimum annual working hours required to participate in plan | h	1,000
Percentage of employee contribution, minimum	1.00%
Percentage of employee contribution, maximum	20.00%
Employer matching contribution	50.00%
Maximum contribution on employees gross pay	4.00%
Contribution by employer under 401(K) plan | $	$ 1	$ 1	$ 1
Number of allocated shares under 401 (K) plan (in shares) | shares	406,021	482,426	515,062
Employee Stock Ownership Plan ("ESOP") [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Maximum annual contribution percentage under ESOP	4.00%
Contributions to ESOP by employer | $	$ 1.6	$ 1.5	$ 1.5
Number of allocated shares under ESOP (in shares) | shares	737,079	788,308	765,630

Employee Benefits, Stock-Based

Employee Benefits, Stock-Based Compensation (Details)		12 Months Ended
		Dec. 31, 2017USD ($)Plan$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of active incentive stock option plan | Plan		1
Number of inactive incentive stock option plan | Plan		2
Number of shares to be issued upon exercise of outstanding stock-based awards and remaining shares available for future issuance [Abstract]
Shares available for future issuance (in shares)		519,140
Black-Scholes option pricing model, weighted average assumptions [Abstract]
Stock-based compensation expense | $		$ 636,000	$ 458,000	$ 783,000
Dividends paid on restricted stock shares | $		53,000	37,000	80,000
Unrecognized compensation cost, grant date fair value of vested shares, cash received from option exercises, and actual tax benefit realized [Abstract]
Unrecognized compensation cost of unvested share-based compensation arrangements granted under the plan at year-end | $		1,242,000	835,000	495,000
Grant date fair value of shares vested for the year | $		564,000	1,490,000	1,111,000
Cash received from option exercises under all share-based payment arrangements for the year | $		693,000	2,099,000	1,212,000
Tax benefit realized for the tax deductions from option exercises of the share-based payment arrangements for the year | $		$ 138,000	$ 3,000	$ 82,000
Expected period for recognition of unrecognized compensation cost		2 years 7 months 6 days
Stock Options [Member]
Number of shares to be issued upon exercise of outstanding stock-based awards and remaining shares available for future issuance [Abstract]
Number of shares to be issued upon exercise (in shares)		45,000
Weighted average price (in dollars per share) | $ / shares		$ 32.26
Shares available for future issuance (in shares)	[1]	519,140
Black-Scholes option pricing model, weighted average assumptions [Abstract]
Expected option life			7 years 6 months	7 years 6 months
Expected volatility			34.34%	43.11%
Expected dividend yield			3.70%	3.72%
Risk-free interest rate			1.45%	1.54%
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (in shares)		550,000
Number of shares to be issued upon exercise of outstanding stock-based awards and remaining shares available for future issuance [Abstract]
Number of shares to be issued upon exercise (in shares)	[2]
Weighted average price (in dollars per share) | $ / shares	[3]
Shares issued (in shares)		33,668
Maximum number of shares to be grant to a participant (in shares)		75,000
Shares available for future issuance (in shares)	[1]
Performance Shares [Member]
Number of shares to be issued upon exercise of outstanding stock-based awards and remaining shares available for future issuance [Abstract]
Number of shares to be issued upon exercise (in shares)	[4]
Weighted average price (in dollars per share) | $ / shares	[3]
Maximum amount of shares to be grant to a participant | $		$ 1,000,000
Shares available for future issuance (in shares)	[1]
Stock Appreciation Rights (SARs) [Member]
Number of shares to be issued upon exercise of outstanding stock-based awards and remaining shares available for future issuance [Abstract]
Number of shares to be issued upon exercise (in shares)	[5]
Weighted average price (in dollars per share) | $ / shares	[3]
Maximum number of shares to be grant to a participant (in shares)		100,000
Shares available for future issuance (in shares)	[1]
2015 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (in shares)		550,000
Number of shares to be issued upon exercise of outstanding stock-based awards and remaining shares available for future issuance [Abstract]
Shares available, beginning of period (in shares)		540,131
Forfeitures (in shares)		2,677
Shares available for future issuance (in shares)		519,140	540,131
2015 Plan [Member] | Stock Options [Member]
Number of shares to be issued upon exercise of outstanding stock-based awards and remaining shares available for future issuance [Abstract]
Issuances (in shares)		0
Options, number of shares [Roll Forward]
Outstanding, beginning of period (in shares)		10,000	0
Granted (in shares)		0	10,000
Exercised (in shares)		0	0
Forfeited/expired (in shares)		0	0
Outstanding, end of period (in shares)		10,000	10,000	0
Exercisable, end of period (in shares)		0	0
Options, weighted average exercise price [Abstract]
Outstanding, beginning of period (in dollars per share) | $ / shares		$ 33.55	$ 0
Granted (in dollars per share) | $ / shares		0	33.55
Exercised (in dollars per share) | $ / shares		0	0
Forfeited/expired (in dollars per share) | $ / shares		0	0
Outstanding, end of period (in dollars per share) | $ / shares		33.55	33.55	$ 0
Exercisable, end of period (in dollars per share) | $ / shares		$ 0	$ 0
Nonvested options, number of shares [Roll Forward]
Nonvested, beginning of period (in shares)		10,000
Granted (in shares)		0	10,000
Vested (in shares)		0
Forfeited (in shares)		0
Nonvested, end of period (in shares)		10,000	10,000
Nonvested options, weighted average grant date fair value [Abstract]
Nonvested, beginning of period (in dollars per share) | $ / shares		$ 6.82
Granted (in dollars per share) | $ / shares		0
Vested (in dollars per share) | $ / shares		0
Forfeited (in dollars per share) | $ / shares		0
Nonvested, end of period (in dollars per share) | $ / shares		$ 6.82	$ 6.82
Options, additional disclosures [Abstract]
Weighted average remaining contractual term		8 years 1 month 6 days
Intrinsic value of options exercised | $		$ 0
Intrinsic value of options exercisable | $		0
Intrinsic value of outstanding options | $		$ 136,000
2015 Plan [Member] | Restricted Stock [Member]
Number of shares to be issued upon exercise of outstanding stock-based awards and remaining shares available for future issuance [Abstract]
Issuances (in shares)		(23,668)
Restricted stock activity, grants [Roll Forward]
Outstanding, beginning of period (in shares)		17,496	0
Granted (in shares)	[6]	23,668	18,069
Vested (in shares)		(5,751)	(442)
Forfeited (in shares)		(2,328)	(131)
Outstanding, end of period (in shares)		33,085	17,496	0
Restricted stock activity, weighted average fair value at grant [Roll Forward]
Outstanding, beginning of period (in dollars per share) | $ / shares		$ 33.55	$ 0
Granted (in dollars per share) | $ / shares	[6]	46.45	33.55
Vested (in dollars per share) | $ / shares		35.79	33.55
Forfeited (in dollars per share) | $ / shares		41.31	33.55
Outstanding, end of period (in dollars per share) | $ / shares		$ 41.84	$ 33.55	$ 0
2006 Plan [Member] | Stock Options [Member]
Options, number of shares [Roll Forward]
Outstanding, beginning of period (in shares)		61,041	118,574	98,821
Granted (in shares)		0	0	20,000
Exercised (in shares)		(25,665)	(57,423)	(247)
Forfeited/expired (in shares)		0	(110)	0
Outstanding, end of period (in shares)		35,376	61,041	118,574
Exercisable, end of period (in shares)		5,376	30,629	87,749
Options, weighted average exercise price [Abstract]
Outstanding, beginning of period (in dollars per share) | $ / shares		$ 29.84	$ 32.36	$ 32.35
Granted (in dollars per share) | $ / shares		0	0	32.27
Exercised (in dollars per share) | $ / shares		27.01	35.02	24.12
Forfeited/expired (in dollars per share) | $ / shares		0	35.41	0
Outstanding, end of period (in dollars per share) | $ / shares		31.90	29.84	32.36
Exercisable, end of period (in dollars per share) | $ / shares		$ 25.22	$ 26.64	$ 32.12
Nonvested options, number of shares [Roll Forward]
Nonvested, beginning of period (in shares)		30,412
Granted (in shares)		0	0	20,000
Vested (in shares)		(412)
Forfeited (in shares)		0
Nonvested, end of period (in shares)		30,000	30,412
Nonvested options, weighted average grant date fair value [Abstract]
Nonvested, beginning of period (in dollars per share) | $ / shares		$ 7
Granted (in dollars per share) | $ / shares		0		$ 6.60
Vested (in dollars per share) | $ / shares		8.23
Forfeited (in dollars per share) | $ / shares		0
Nonvested, end of period (in dollars per share) | $ / shares		$ 6.98	$ 7
Options, additional disclosures [Abstract]
Weighted average remaining contractual term		6 years
Weighted average fair value of options granted | $				$ 100,000
Intrinsic value of options exercised | $		$ 537,000	$ 139,000	3,000
Intrinsic value of options exercisable | $		118,000	703,000	275,000
Intrinsic value of outstanding options | $		$ 538,000	$ 1,206,000	$ 334,000
2006 Plan [Member] | Restricted Stock [Member]
Number of shares to be issued upon exercise of outstanding stock-based awards and remaining shares available for future issuance [Abstract]
Shares issued (in shares)				18,069
Restricted stock activity, grants [Roll Forward]
Outstanding, beginning of period (in shares)		11,989	64,735	101,309
Granted (in shares)		0	0	10,582
Vested (in shares)		(6,214)	(52,521)	(46,482)
Forfeited (in shares)		(349)	(225)	(674)
Outstanding, end of period (in shares)		5,426	11,989	64,735
Restricted stock activity, weighted average fair value at grant [Roll Forward]
Outstanding, beginning of period (in dollars per share) | $ / shares		$ 32.85	$ 28.92	$ 26.19
Granted (in dollars per share) | $ / shares		0	0	32.27
Vested (in dollars per share) | $ / shares		32.48	28.01	23.66
Forfeited (in dollars per share) | $ / shares		33.31	32.52	33.31
Outstanding, end of period (in dollars per share) | $ / shares		$ 33.24	$ 32.85	$ 28.92
1998 Plan [Member] | Stock Options [Member]
Options, number of shares [Roll Forward]
Outstanding, beginning of period (in shares)		0	2,980	43,960
Granted (in shares)			0	0
Exercised (in shares)			(2,980)	(40,980)
Forfeited/expired (in shares)			0	0
Outstanding, end of period (in shares)			0	2,980
Exercisable, end of period (in shares)			0	2,980
Options, weighted average exercise price [Abstract]
Outstanding, beginning of period (in dollars per share) | $ / shares		$ 0	$ 29.49	$ 29.43
Granted (in dollars per share) | $ / shares			0	0
Exercised (in dollars per share) | $ / shares			29.49	29.42
Forfeited/expired (in dollars per share) | $ / shares			0	0
Outstanding, end of period (in dollars per share) | $ / shares			0	29.49
Exercisable, end of period (in dollars per share) | $ / shares			$ 0	$ 29.49
Nonvested options, number of shares [Roll Forward]
Nonvested, beginning of period (in shares)		0	0
Granted (in shares)			0	0
Nonvested, end of period (in shares)		0	0	0
Options, additional disclosures [Abstract]
Intrinsic value of options exercised | $			$ 13,000	$ 241,000
Intrinsic value of options exercisable | $			0	16,000
Intrinsic value of outstanding options | $			$ 0	$ 16,000
[1]	Under the 2015 Plan, 550,000 shares are authorized for issuance; 33,668 have been issued as of December 31, 2017. In January of 2016, 18,069 restricted stock shares were issued under the terms of the 2015 Plan pursuant to awards granted under the 2006 Plan. Additional shares will not be issued pursuant to awards granted from prior plans.
[2]	The maximum number of shares of restricted stock that may be granted is 550,000 shares, and the maximum that may be granted to a participant during any calendar year is 75,000 shares.
[3]	Not applicable
[4]	No performance units payable in stock had been issued as of December 31, 2017. The maximum payment that can be made pursuant to performance units granted to any one participant in any calendar year shall be $1,000,000.
[5]	No SARS have been issued. The maximum number of shares with respect to which SARs may be granted to a participant during any calendar year shall be 100,000 shares.
[6]	Grants issued in 2016 were issued under the terms of the 2015 Plan pursuant to awards granted and earned under the 2006 Plan.

Operating Leases (Details)

Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Payments [Abstract]
2,018	$ 2,050
2,019	1,673
2,020	1,626
2,021	1,515
2,022	1,392
Thereafter	3,783
Total	12,039
Receipts [Abstract]
2,018	574
2,019	411
2,020	351
2,021	235
2,022	100
Thereafter	145
Total	1,816
Rental expense net of rental income under operating leases	$ 1,400	$ 1,300	$ 1,300

Fair Market Value of Financia81

Fair Market Value of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 585,761	$ 605,394
Impaired loan (collateral dependent) [Abstract]
Impaired loans, fair value adjustments	1,000	600
Other real estate owned [Abstract]
Other real estate owned, fair value adjustment	2,500	1,200
Reconciliation of beginning and ending balances of recurring fair value measurements recognized in balance sheet using significant unobservable (Level 3) inputs [Roll Forward]
Total losses	$ (361)	(324)	$ (289)
Minimum [Member]
Other real estate owned [Abstract]
Typical frequency of periodic reviews	12 months
Maximum [Member]
Other real estate owned [Abstract]
Typical frequency of periodic reviews	18 months
Frequency of periodic reviews in general	24 months
Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 88,956	69,292
Fair Value [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	496,805	536,102
Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	3,484	3,433
Recurring [Member] | U.S. Treasury and Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	210,572	222,464
Recurring [Member] | State and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	145,015	133,516
Recurring [Member] | U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	205,309	225,056
Recurring [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	507	0
Recurring [Member] | CRA Investment Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	24,358	24,358
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Treasury and Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	64,598	44,934
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | State and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | CRA Investment Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	24,358	24,358
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	0	0
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. Treasury and Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	145,974	177,530
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | State and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	145,015	133,516
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	205,309	225,056
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	507	0
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | CRA Investment Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	3,484	3,433
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | U.S. Treasury and Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | State and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | CRA Investment Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Mortgage Servicing Rights [Member]
Reconciliation of beginning and ending balances of recurring fair value measurements recognized in balance sheet using significant unobservable (Level 3) inputs [Roll Forward]
Beginning balance	3,433	3,236
Total recognized gains (losses) Included in net income	91	164
Issues	412	521
Settlements	(452)	(488)
Ending balance	3,484	3,433	$ 3,236
Total gains (losses) for the period included in net income attributable to the change in unrealized gains or losses related to assets still held at the reporting date	91	164
Nonrecurring [Member]
Assets measured-nonrecurring basis [Abstract]
Impaired loans (collateral dependent)	2,709	5,506
Other real estate owned	18,951	4,388
Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets measured-nonrecurring basis [Abstract]
Impaired loans (collateral dependent)	0	0
Other real estate owned	0	0
Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets measured-nonrecurring basis [Abstract]
Impaired loans (collateral dependent)	0	0
Other real estate owned	0	0
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets measured-nonrecurring basis [Abstract]
Impaired loans (collateral dependent)	2,709	5,506
Other real estate owned	$ 18,951	$ 4,388

Fair Market Value of Financia82

Fair Market Value of Financial Assets and Liabilities, Quantitative Information about Level 3 Fair Value Measurements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Mortgage Servicing Rights [Member] | Discount Cash Flows, Computer Pricing Model [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 3,484	$ 3,433
Mortgage Servicing Rights [Member] | Discount Cash Flows, Computer Pricing Model [Member] | Significant Unobservable Inputs (Level 3) [Member] | Minimum [Member]
Unobservable inputs [Abstract]
Constant prepayment rate	7.00%	7.00%
Probability of default	0.00%	0.00%
Discount rate	10.00%	10.00%
Mortgage Servicing Rights [Member] | Discount Cash Flows, Computer Pricing Model [Member] | Significant Unobservable Inputs (Level 3) [Member] | Maximum [Member]
Unobservable inputs [Abstract]
Constant prepayment rate	45.00%	27.00%
Probability of default	100.00%	100.00%
Discount rate	11.50%	11.50%
Mortgage Servicing Rights [Member] | Discount Cash Flows, Computer Pricing Model [Member] | Significant Unobservable Inputs (Level 3) [Member] | Weighted Average [Member]
Unobservable inputs [Abstract]
Constant prepayment rate	10.00%	9.50%
Probability of default	3.00%	3.00%
Discount rate	10.10%	10.10%
Impaired Loans (Collateral Dependent) [Member] | Market Comparable Properties [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 2,709	$ 5,506
Impaired Loans (Collateral Dependent) [Member] | Market Comparable Properties [Member] | Significant Unobservable Inputs (Level 3) [Member] | Minimum [Member]
Unobservable inputs [Abstract]
Marketability discount	1.90%	0.00%
Impaired Loans (Collateral Dependent) [Member] | Market Comparable Properties [Member] | Significant Unobservable Inputs (Level 3) [Member] | Maximum [Member]
Unobservable inputs [Abstract]
Marketability discount	89.80%	100.00%
Impaired Loans (Collateral Dependent) [Member] | Market Comparable Properties [Member] | Significant Unobservable Inputs (Level 3) [Member] | Weighted Average [Member]
Unobservable inputs [Abstract]
Marketability discount	38.50%	33.70%
Other Real Estate Owned [Member] | Market Comparable Properties [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 18,951	$ 4,388
Other Real Estate Owned [Member] | Market Comparable Properties [Member] | Significant Unobservable Inputs (Level 3) [Member] | Minimum [Member]
Unobservable inputs [Abstract]
Comparability adjustments	6.00%	10.00%
Other Real Estate Owned [Member] | Market Comparable Properties [Member] | Significant Unobservable Inputs (Level 3) [Member] | Maximum [Member]
Unobservable inputs [Abstract]
Comparability adjustments	58.60%	100.00%
Other Real Estate Owned [Member] | Market Comparable Properties [Member] | Significant Unobservable Inputs (Level 3) [Member] | Weighted Average [Member]
Unobservable inputs [Abstract]
Comparability adjustments	15.00%	14.90%

Fair Market Value of Financia83

Fair Market Value of Financial Assets and Liabilities, Estimated Fair Value of Financial Instruments and Indication of Level Within Fair Value Hierarchy of Valuation Techniques (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financial assets [Abstract]
Securities available-for-sale	$ 585,761	$ 605,394
Securities held-to-maturity	660	867
Mortgage servicing rights	3,484	3,433	$ 3,236	$ 2,968
Carrying Amount [Member]
Financial assets [Abstract]
Cash and cash equivalents	175,274	144,716
Certificates of deposits in other banks	9,800	980
Securities available-for-sale	585,761	605,394
Securities held-to-maturity	659	866
Loans held for sale	1,033	1,244
Loans, net	3,086,789	2,902,438
Federal Home Loan Bank stock	17,927	17,927
Federal Reserve Bank stock	4,887	4,887
Accrued interest receivable	13,338	11,922
Mortgage servicing rights	3,484	3,433
Financial liabilities [Abstract]
Deposits	3,263,863	3,081,308
Repurchase agreements	243,814	251,065
Federal funds purchased	7,312	4,816
Advances from Federal Home Loan Bank	845	944
Long-term debt	59,341	61,341
Accrued interest payable	2,228	1,200
Unrecognized financial instruments [Abstract]
Letters of credit	0	0
Commitments to extend credit	0	0
Forward sale commitments	0	0
Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets [Abstract]
Cash and cash equivalents	175,274	144,716
Certificates of deposits in other banks	0	0
Securities available-for-sale	88,956	69,292
Securities held-to-maturity	0	0
Loans held for sale	1,060	1,260
Loans, net	0	0
Federal Home Loan Bank stock	0	0
Federal Reserve Bank stock	0	0
Accrued interest receivable	0	0
Mortgage servicing rights	0	0
Financial liabilities [Abstract]
Deposits	790,930	767,918
Repurchase agreements	0	0
Federal funds purchased	0	0
Advances from Federal Home Loan Bank	0	0
Long-term debt	0	0
Accrued interest payable	0	0
Unrecognized financial instruments [Abstract]
Letters of credit	0	0
Commitments to extend credit	0	0
Forward sale commitments	0	0
Fair Value [Member] | Significant Other Observable Inputs (Level 2) [Member]
Financial assets [Abstract]
Cash and cash equivalents	0	0
Certificates of deposits in other banks	9,772	982
Securities available-for-sale	496,805	536,102
Securities held-to-maturity	660	867
Loans held for sale	0	0
Loans, net	0	0
Federal Home Loan Bank stock	17,927	17,927
Federal Reserve Bank stock	4,887	4,887
Accrued interest receivable	13,338	11,922
Mortgage servicing rights	0	0
Financial liabilities [Abstract]
Deposits	2,319,278	2,321,690
Repurchase agreements	0	0
Federal funds purchased	7,312	4,816
Advances from Federal Home Loan Bank	841	1,009
Long-term debt	0	0
Accrued interest payable	2,228	1,200
Unrecognized financial instruments [Abstract]
Letters of credit	0	0
Commitments to extend credit	0	0
Forward sale commitments	0	0
Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets [Abstract]
Cash and cash equivalents	0	0
Certificates of deposits in other banks	0	0
Securities available-for-sale	0	0
Securities held-to-maturity	0	0
Loans held for sale	0	0
Loans, net	3,092,437	2,882,348
Federal Home Loan Bank stock	0	0
Federal Reserve Bank stock	0	0
Accrued interest receivable	0	0
Mortgage servicing rights	3,484	3,433
Financial liabilities [Abstract]
Deposits	0	0
Repurchase agreements	243,932	250,820
Federal funds purchased	0	0
Advances from Federal Home Loan Bank	0	0
Long-term debt	44,166	49,073
Accrued interest payable	0	0
Unrecognized financial instruments [Abstract]
Letters of credit	0	0
Commitments to extend credit	0	0
Forward sale commitments	$ 0	$ 0

Off-Balance Sheet Transaction84

Off-Balance Sheet Transactions and Guarantees (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total off-balance sheet financial instruments	$ 546,039	$ 600,384
Mortgage loans held for sale	1,033	1,244
Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total off-balance sheet financial instruments	29,308	29,917
Credit loss reserve	$ 7
Percentage of secured standby letters of credit	64.00%
Standby letters of credit secured by cash	$ 15,300
Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total off-balance sheet financial instruments	516,731	570,467
Credit loss reserve	248
Fixed rate loan commitments amount	$ 52,200
Period of commitment to sell the loans at specified prices	60 days
Total mortgage loans in process	$ 2,500	2,900
Mortgage loans held for sale	$ 1,033	$ 1,244
Commitments to Extend Credit [Member] | Minimum [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Interest rate on loan commitments	3.00%
Commitments to Extend Credit [Member] | Maximum [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Interest rate on loan commitments	5.00%
Fixed rate loan commitments term	2 years

Concentrations of Credit Risk (

Concentrations of Credit Risk (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Hotel/Motel Industry Credits [Member]
Concentration Risk [Line Items]
Concentration of credit risk	47.00%	41.00%
Lessors of Non-residential Buildings Credits [Member]
Concentration Risk [Line Items]
Concentration of credit risk	45.00%	45.00%
Lessors of Residential Buildings and Dwellings Credits [Member]
Concentration Risk [Line Items]
Concentration of credit risk	39.00%	37.00%

Commitments and Contingencies (

Commitments and Contingencies (Details)	12 Months Ended
	Dec. 31, 2017Review
Unfavorable Regulatory Action [Member]
Loss Contingencies [Line Items]
Number of CTB deposit add-on products under review	2

Regulatory Matters (Details)

Regulatory Matters (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Tier I capital (to average assets), Amount [Abstract]
Actual Amount	$ 525,707	$ 496,432
For Capital Adequacy Purposes	$ 163,136	$ 155,743
Tier I capital (to average assets), Ratio [Abstract]
Actual Ratio	12.89%	12.75%
For Capital Adequacy Purposes	4.00%	4.00%
Common equity Tier 1 capital (to risk weighted assets), Amount [Abstract]
Actual Amount	$ 468,207	$ 436,932
For Capital Adequacy Purposes	$ 137,438	$ 129,525
Common equity Tier 1 capital (to risk weighted assets), Ratio [Abstract]
Actual Ratio	15.33%	15.18%
For Capital Adequacy Purposes	4.50%	4.50%
Tier I capital (to risk weighted assets), Amount [Abstract]
Actual Amount	$ 525,707	$ 496,432
For Capital Adequacy Purposes	$ 183,173	$ 172,672
Tier I capital (to risk weighted assets), Ratio [Abstract]
Actual Ratio	17.22%	17.25%
For Capital Adequacy Purposes	6.00%	6.00%
Total capital (to risk weighted assets), Amount [Abstract]
Actual Amount	$ 562,114	$ 532,332
For Capital Adequacy Purposes	$ 244,265	$ 230,198
Total capital (to risk-weighted assets), Ratio [Abstract]
Actual Ratio	18.41%	18.50%
For Capital Adequacy Purposes	8.00%	8.00%
Community Trust Bank, Inc [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Maximum dividend without Approval	$ 56,100
Tier I capital (to average assets), Amount [Abstract]
Actual Amount	501,537	$ 472,615
For Capital Adequacy Purposes	162,441	155,083
To Be Well-Capitalized Under Prompt Corrective Action Provision	$ 203,051	$ 193,854
Tier I capital (to average assets), Ratio [Abstract]
Actual Ratio	12.35%	12.19%
For Capital Adequacy Purposes	4.00%	4.00%
To Be Well-Capitalized Under Prompt Corrective Action Provision	5.00%	5.00%
Common equity Tier 1 capital (to risk weighted assets), Amount [Abstract]
Actual Amount	$ 501,537	$ 472,615
For Capital Adequacy Purposes	137,115	129,208
To Be Well-Capitalized Under Prompt Corrective Action Provision	$ 198,055	$ 186,634
Common equity Tier 1 capital (to risk weighted assets), Ratio [Abstract]
Actual Ratio	16.46%	16.46%
For Capital Adequacy Purposes	4.50%	4.50%
To Be Well-Capitalized Under Prompt Corrective Action Provision	6.50%	6.50%
Tier I capital (to risk weighted assets), Amount [Abstract]
Actual Amount	$ 501,537	$ 472,615
For Capital Adequacy Purposes	182,820	172,278
To Be Well-Capitalized Under Prompt Corrective Action Provision	$ 243,760	$ 229,704
Tier I capital (to risk weighted assets), Ratio [Abstract]
Actual Ratio	16.46%	16.46%
For Capital Adequacy Purposes	6.00%	6.00%
To Be Well-Capitalized Under Prompt Corrective Action Provision	8.00%	8.00%
Total capital (to risk weighted assets), Amount [Abstract]
Actual Amount	$ 537,944	$ 508,515
For Capital Adequacy Purposes	243,827	229,708
To Be Well-Capitalized Under Prompt Corrective Action Provision	$ 304,784	$ 287,134
Total capital (to risk-weighted assets), Ratio [Abstract]
Actual Ratio	17.65%	17.71%
For Capital Adequacy Purposes	8.00%	8.00%
To Be Well-Capitalized Under Prompt Corrective Action Provision	10.00%	10.00%

Parent Company Financial Stat88

Parent Company Financial Statements, Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets [Abstract]
Cash on deposit	$ 47,528	$ 48,603
Goodwill	65,490	65,490
Premises and equipment, net	46,318	47,940
Other assets	41,459	36,984
Total assets	4,136,231	3,932,169
Liabilities and shareholders' equity [Abstract]
Long-term debt	59,341	61,341
Other liabilities	25,923	24,244
Total liabilities	3,605,532	3,431,554
Shareholders' equity	530,699	500,615
Total liabilities and shareholders' equity	4,136,231	3,932,169
Parent Company [Member]
Assets [Abstract]
Cash on deposit	1,500	1,525
Investment in and advances to subsidiaries	587,575	556,975
Goodwill	4,973	4,973
Premises and equipment, net	250	142
Other assets	200	391
Total assets	594,498	564,006
Liabilities and shareholders' equity [Abstract]
Long-term debt	61,341	61,341
Other liabilities	2,458	2,050
Total liabilities	63,799	63,391
Shareholders' equity	530,699	500,615
Total liabilities and shareholders' equity	$ 594,498	$ 564,006

Parent Company Financial Stat89

Parent Company Financial Statements, Condensed Statements of Income and Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Expenses [Abstract]
Interest expense	$ 18,294	$ 13,555	$ 11,773
Other expenses	11,901	12,077	11,780
Income before income taxes and equity in undistributed income of subsidiaries	68,511	66,464	64,963
Income tax benefit	17,018	19,118	18,531
Net income	51,493	47,346	46,432
Unrealized holding losses on securities available-for-sale [Abstract]
Unrealized holding losses arising during the period	(820)	(4,578)	(342)
Less: Reclassification adjustments for realized gains (losses) included in net income	73	522	(106)
Implementation of ASU 2018-02	(621)	0	0
Other comprehensive loss, net of tax	(1,202)	(3,315)	(153)
Comprehensive income	50,291	44,031	46,279
Parent Company [Member]
Income [Abstract]
Dividends from subsidiary banks	24,661	20,708	19,808
Other income	904	459	414
Total income	25,565	21,167	20,222
Expenses [Abstract]
Interest expense	1,723	1,417	1,170
Depreciation expense	116	107	130
Other expenses	2,858	2,256	2,465
Total expenses	4,697	3,780	3,765
Income before income taxes and equity in undistributed income of subsidiaries	20,868	17,387	16,457
Income tax benefit	(1,445)	(1,373)	(1,371)
Income before equity in undistributed income of subsidiaries	22,313	18,760	17,828
Equity in undistributed income of subsidiaries	29,180	28,586	28,604
Net income	51,493	47,346	46,432
Unrealized holding losses on securities available-for-sale [Abstract]
Unrealized holding losses arising during the period	(820)	(4,578)	(342)
Less: Reclassification adjustments for realized gains (losses) included in net income	73	522	(106)
Tax benefit	(312)	(1,785)	(83)
Implementation of ASU 2018-02	(621)	0	0
Other comprehensive loss, net of tax	(1,202)	(3,315)	(153)
Comprehensive income	$ 50,291	$ 44,031	$ 46,279

Parent Company Financial Stat90

Parent Company Financial Statements, Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities [Abstract]
Net income	$ 51,493	$ 47,346	$ 46,432
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Depreciation	4,007	3,904	3,932
Stock-based compensation	636	458	783
Excess tax benefits of stock-based compensation	0	100	104
Gain on debt repurchase	(560)	0	0
Changes in [Abstract]
Other assets	(4,412)	(3,205)	(6,274)
Other liabilities	1,631	2,874	(2,488)
Net cash provided by operating activities	62,351	61,425	54,979
Cash flows from investing activities [Abstract]
Purchase of premises and equipment	(2,400)	(3,498)	(2,246)
Net cash used in investing activities	(186,586)	(86,107)	(108,349)
Cash flows from financing activities [Abstract]
Issuance of common stock	1,513	2,985	2,082
Repurchase of common stock	0	(382)	(189)
Excess tax benefits of stock-based compensation	0	(100)	(104)
Dividends paid	(22,981)	(22,190)	(21,330)
Net cash provided by (used in) financing activities	154,793	(18,213)	135,464
Net increase (decrease) in cash and cash equivalents	30,558	(42,895)	82,094
Cash and cash equivalents at beginning of year	144,716	187,611	105,517
Cash and cash equivalents at end of year	175,274	144,716	187,611
Parent Company [Member]
Cash flows from operating activities [Abstract]
Net income	51,493	47,346	46,432
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Depreciation	116	107	130
Equity in undistributed earnings of subsidiaries	(29,180)	(28,586)	(28,604)
Stock-based compensation	636	458	783
Excess tax benefits of stock-based compensation	0	100	104
Gain on debt repurchase	(560)	0	0
Changes in [Abstract]
Other assets	145	519	240
Other liabilities	412	(90)	968
Net cash provided by operating activities	23,062	19,854	20,053
Cash flows from investing activities [Abstract]
Payment for investment in subsidiary	(1,440)	0	0
Purchase of premises and equipment	(179)	(104)	(45)
Net cash used in investing activities	(1,619)	(104)	(45)
Cash flows from financing activities [Abstract]
Issuance of common stock	1,513	2,985	2,082
Repurchase of common stock	0	(382)	(189)
Excess tax benefits of stock-based compensation	0	(100)	(104)
Dividends paid	(22,981)	(22,190)	(21,330)
Net cash provided by (used in) financing activities	(21,468)	(19,687)	(19,541)
Net increase (decrease) in cash and cash equivalents	(25)	63	467
Cash and cash equivalents at beginning of year	1,525	1,462	995
Cash and cash equivalents at end of year	$ 1,500	$ 1,525	$ 1,462

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Numerator [Abstract]
Net income	$ 51,493	$ 47,346	$ 46,432
Basic earnings per share [Abstract]
Weighted average shares (in shares)	17,631,000	17,548,000	17,431,000
Diluted earnings per share [Abstract]
Dilutive effect of equity grants (in shares)	22,000	18,000	52,000
Adjusted weighted average shares (in shares)	17,653,000	17,566,000	17,483,000
Earnings per share [Abstract]
Basic earnings per share (in dollars per share)	$ 2.92	$ 2.70	$ 2.66
Diluted earnings per share (in dollars per share)	$ 2.92	$ 2.70	$ 2.66
Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options excluded from diluted calculations (in shares)	0	0	58,063
Weighted average price of outstanding options (in dollars per share)			$ 35.409

Accumulated Other Comprehensi92

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Securities gains (losses)	$ 73	$ 522	$ (106)
Tax expense (benefit)	17,018	19,118	18,531
Net income	51,493	47,346	46,432
Unrealized Gains (Losses) on AFS Securities [Member] | Reclassification Out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Securities gains (losses)	73	522	(106)
Tax expense (benefit)	26	183	(37)
Net income	$ 47	$ 339	$ (69)