Park National (PRK) 10-K 27 Feb 18 2017 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 26, 2018	Jun. 30, 2017
Entity Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Entity Registrant Name	PARK NATIONAL CORP /OH/
Entity Central Index Key	805,676
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Common Stock, Shares Outstanding		15,288,185
Entity Public Float			$ 1,556,752,306

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Cash and due from banks	$ 131,946	$ 122,811
Money market instruments	37,166	23,635
Cash and cash equivalents	169,112	146,446
Investment securities:
Securities available-for-sale, at fair value (amortized cost of $1,098,320 and $1,262,761 at December 31, 2017 and 2016, respectively)	1,093,816	1,258,139
Securities held-to-maturity, at amortized cost (fair value of $363,779 and $256,672 at December 31, 2017 and 2016, respectively)	357,197	259,833
Other investment securities	61,811	61,811
Total investment securities	1,512,824	1,579,783
Total loans	5,372,483	5,271,857
Allowance for loan losses	(49,988)	(50,624)
Net loans	5,322,495	5,221,233
Other assets:
Bank owned life insurance	189,322	185,234
Prepaid assets	97,712	88,874
Goodwill	72,334	72,334
Premises and equipment, net	55,901	57,971
Affordable housing tax credit investments	49,669	52,947
Accrued interest receivable	22,164	18,822
Other real estate owned	14,190	13,926
Mortgage loan servicing rights	9,688	9,266
Other	22,209	20,750
Total other assets	533,189	520,124
Total assets	7,537,620	7,467,586
Deposits:
Non-interest bearing	1,633,941	1,523,417
Interest bearing	4,183,385	3,998,539
Total deposits	5,817,326	5,521,956
Short-term borrowings	391,289	394,795
Long-term debt	500,000	694,281
Subordinated notes	15,000	45,000
Total borrowings	906,289	1,134,076
Other liabilities:
Accrued interest payable	2,278	2,151
Unfunded commitments in affordable housing tax credit investments	14,282	14,282
Other	41,344	52,881
Total other liabilities	57,904	69,314
Total liabilities	6,781,519	6,725,346
Commitments and Contingencies
Shareholders’ equity:
Preferred Stock, Value, Issued	0	0
Common shares, no par value (20,000,000 common shares authorized; 16,150,752 and 16,150,807 common shares issued at December 31, 2017 and 2016, respectively)	307,726	305,826
Accumulated other comprehensive loss, net	(26,454)	(17,745)
Retained earnings	561,908	535,631
Less: Treasury shares (862,558 and 810,089 common shares at December 31, 2017 and 2016, respectively)	(87,079)	(81,472)
Total shareholders’ equity	756,101	742,240
Total liabilities and shareholders’ equity	$ 7,537,620	$ 7,467,586

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Amortized cost of securities available-for-sale	$ 1,098,320	$ 1,262,761
Fair value of securities held-to-maturity	$ 363,779	$ 256,672
Preferred stock, shares authorized	200,000	200,000
Preferred stock, shares issued	0	0
Preferred stock per share liquidation preference	$ 0	$ 0
Common stock, no par value	$ 0	$ 0
Common stock, shares authorized	20,000,000	20,000,000
Common stock stock, shares issued	16,150,752	16,150,807
Treasury stock, shares	862,558	810,089

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest and dividend income:
Interest and fees on loans	$ 248,687	$ 241,979	$ 227,979
Interest and dividends on:
Obligations of U.S. Government, its agencies and other securities - taxable	27,440	30,627	36,025
Obligations of states and political subdivisions - tax-exempt	7,210	2,632	182
Other interest income	3,087	1,020	888
Total interest and dividend income	286,424	276,258	265,074
Interest on deposits:
Demand and savings deposits	9,464	4,079	2,229
Time deposits	9,629	9,337	10,125
Interest on short-term borrowings	992	456	469
Interest on long-term debt	22,580	24,300	24,619
Total interest expense	42,665	38,172	37,442
Net interest income	243,759	238,086	227,632
Provision for (recovery of) loan losses	8,557	(5,101)	4,990
Net interest income after provision for (recovery of) loan losses	235,202	243,187	222,642
Other income:
Income from fiduciary activities	23,735	21,400	20,195
Service charges on deposit accounts	12,653	14,259	14,751
Gain on sale of investment securities	1,821	0	88
Other service income	13,162	14,419	11,438
Checkcard fee income	15,798	15,057	14,561
Bank owned life insurance income	4,858	4,338	5,783
ATM fees	2,253	2,268	2,428
Gain on sale of OREO, net	251	1,323	1,604
OREO valuation adjustments	(458)	(601)	(1,592)
Gain on commercial loans held for sale	0	0	756
Miscellaneous	6,562	6,268	7,539
Total other income	80,635	78,731	77,551
Other expense:
Salaries	92,177	87,034	86,189
Employee benefits	19,918	19,262	21,296
Data processing fees	7,250	5,608	5,037
Professional fees and services	24,833	27,181	23,452
Occupancy expense	10,201	10,239	9,686
Furniture and equipment expense	15,324	13,766	11,806
Insurance	6,354	5,825	5,629
Marketing	4,374	4,523	3,983
Communication	4,826	4,985	5,130
State tax expense	3,583	3,560	3,566
Prepayment penalty on long-term debt	0	5,554	532
Miscellaneous	8,528	11,486	10,308
Total other expense	197,368	199,023	186,614
Income (loss) before taxes	118,469	122,895	113,579
Federal income taxes	34,227	36,760	32,567
Net income	$ 84,242	$ 86,135	$ 81,012
Earnings per common share:
Basic (in dollars per share)	$ 5.51	$ 5.62	$ 5.27
Diluted (in dollars per share)	$ 5.47	$ 5.59	$ 5.26

Statements of Comprehensive Inc

Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	$ 84,242	$ 86,135	$ 81,012
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax	(455)	(502)	(424)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, after Tax	9,241	(109)	910
Other comprehensive (loss) income, net of income tax:
Changes in pension plan assets and benefit obligations recognized in other comprehensive income	(8,786)	611	(486)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax	(1,184)	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Reclassification Adjustments, Net of Tax	1,261	(2,713)	(1,549)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	77	(2,713)	(1,549)
Other Comprehensive Income (Loss), Net of Tax	(8,709)	(2,102)	(2,035)
Comprehensive income	$ 75,533	$ 84,033	$ 78,977

Statements of Comprehensive In6

Statements of Comprehensive Income (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax	$ 455,000	$ 502,000	$ 424,000
Tax Effect
Amortization of net loss and prior service costs, tax expense	121	271	228
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax	(2,457)	59	(490)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	(637)	0	0
Unrealized net holding gain (loss) on securities available-for-sale, tax expense	678	(1,461)	(834)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, after Tax	$ (9,241,000)	$ 109,000	$ (910,000)

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred Shares	Common Shares	Retained Earnings	Treasury Shares	Accumulated Other Comprehensive (Loss) Income
Beginning balance at Dec. 31, 2014		$ 0	$ 303,104	$ 484,484	$ (77,439)	$ (13,608)
Beginning balance, shares at Dec. 31, 2014		0	15,392,399
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 81,012			81,012
Other comprehensive (loss) income, net of income tax:
Other Comprehensive Income (Loss), Net of Tax	$ (2,035)					(2,035)
Cash dividends				(57,930)
Fractional shares issued in dividend reinvestment plan, shares			(34)
Cash payment for fractional shares in dividend reinvestment plan			$ (3)
Allocated Share-based Compensation Expense			$ 865
Treasury Stock, Shares, Acquired			(71,700)
Treasury Stock, Value, Acquired, Cost Method					6,058
Treasury Stock Reissued Shares For Director Grants	10,150		10,150
Treasury shares reissued for director grants				(61)	1,024
Ending balance at Dec. 31, 2015		$ 0	$ 303,966	507,505	(82,473)	(15,643)
Ending balance, shares at Dec. 31, 2015		0	15,330,815
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 86,135			86,135
Other comprehensive (loss) income, net of income tax:
Other Comprehensive Income (Loss), Net of Tax	$ (2,102)					(2,102)
Cash dividends				(57,958)
Fractional shares issued in dividend reinvestment plan, shares			(47)
Cash payment for fractional shares in dividend reinvestment plan			$ (4)
Allocated Share-based Compensation Expense			$ 1,864
Treasury Stock, Shares, Acquired			0
Treasury Stock Reissued Shares For Director Grants	9,950		9,950
Treasury shares reissued for director grants				(51)	1,001
Ending balance at Dec. 31, 2016	$ 742,240	$ 0	$ 305,826	535,631	(81,472)	(17,745)
Ending balance, shares at Dec. 31, 2016		0	15,340,718
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	84,242			84,242
Other comprehensive (loss) income, net of income tax:
Other Comprehensive Income (Loss), Net of Tax	$ (8,709)					(8,709)
Cash dividends				(57,883)
Fractional shares issued in dividend reinvestment plan, shares			(55)
Cash payment for fractional shares in dividend reinvestment plan			$ (6)
Allocated Share-based Compensation Expense			2,701
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures	6,381
Stock Granted, Value, Share-based Compensation, Net of Forfeitures			$ (795)	(197)	(645)
Treasury Stock, Shares, Acquired			(70,000)
Treasury Stock, Value, Acquired, Cost Method					7,378
Treasury Stock Reissued Shares For Director Grants	11,150		11,150
Treasury shares reissued for director grants				115	1,126
Ending balance at Dec. 31, 2017	$ 756,101	$ 0	$ 307,726	$ 561,908	$ (87,079)	$ (26,454)
Ending balance, shares at Dec. 31, 2017		0	15,288,194

Consolidated Statements of Cha8

Consolidated Statements of Changes In Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Common Stock, Dividends, Per Share, Cash Paid	$ 3.76	$ 3.76	$ 3.76

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest Paid	$ 42,538	$ 38,359	$ 37,655
Operating activities:
Net income	84,242	86,135	81,012
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for (recovery of) loan losses	8,557	(5,101)	4,990
Amortization of loan fees and costs, net	(5,758)	(5,279)	(4,918)
Provision for depreciation	8,644	8,396	7,347
Amortization (accretion) of investment securities, net	1,473	247	(226)
Amortization of prepayment penalty on long-term debt	5,719	6,176	6,047
Prepayment penalty on long-term debt	0	5,554	532
(Increase) decrease in deferred income tax	3,289	581	(250)
Realized net investment security gains	(1,821)	0	0
Loan originations to be sold in secondary market	(230,860)	(287,722)	(220,800)
Proceeds from sale of loans in secondary market	242,139	290,132	222,785
Gain on sale of commercial loans held for sale	0	0	(756)
Share-based compensation expense	3,942	2,814	1,828
OREO valuation adjustments	458	601	1,592
Gain on sale of OREO, net	(251)	(1,323)	(1,604)
Bank owned life insurance income	(4,858)	(4,338)	(5,783)
Investment in qualified affordable housing tax credits amortization	10,278	7,300	6,664
Pension contribution	(15,000)	0	0
Changes in assets and liabilities:
Decrease (increase) in other assets	(1,060)	(7,042)	(3,448)
(Decrease) increase in other liabilities	(11,778)	2,006	1,173
Net cash provided by operating activities	87,991	87,887	89,234
Investing activities:
Proceeds from sales of securities	2,265	0	3,144
Proceeds from calls and maturities of securities:
Held-to-maturity	14,426	29,901	36,393
Available-for-sale	193,937	753,325	321,146
Purchase of securities:
Held-to-maturity	(113,519)	(141,045)	(48,226)
Available-for-sale	(29,684)	(579,006)	(457,617)
Net increase in other investments	0	(3,500)	0
Net loan originations, portfolio loans	119,336	199,494	247,882
Proceeds from sale of commercial loans held for sale	0	0	900
Investment in qualified affordable housing projects	(7,000)	(15,029)	(5,318)
Proceeds from the sale of OREO	2,921	8,704	17,058
Purchases of bank owned life insurance, net	0	0	10,045
Purchases of premises and equipment, net	(7,018)	(7,466)	(11,361)
Life insurance death benefits	1,037	1,050	6,340
Net cash used in investing activities	(61,971)	(152,560)	(395,468)
Financing activities
Net increase in deposits	295,370	174,314	219,642
Net (decrease) increase in short-term borrowings	(3,506)	553	117,262
Proceeds from issuance of long-term debt	150,000	0	25,000
Repayment of subordinated notes	(30,000)	0	0
Repayment of long-term debt	(350,000)	(55,554)	(80,076)
Value of common shares withheld to pay employee income taxes	(347)	0	0
Cash dividends paid	(57,493)	(57,653)	(57,776)
Net cash (used in) provided by financing activities	(3,354)	61,660	217,994
Increase (decrease) in cash and cash equivalents	22,666	(3,013)	(88,240)
Cash and cash equivalents at beginning of year	146,446	149,459	237,699
Cash and cash equivalents at end of year	169,112	146,446	149,459
Income Taxes Paid	26,190	27,260	26,140
Non cash activities [Abstract]
Real Estate Owned, Transfer to Real Estate Owned	3,457	3,339	13,447
Transfer of Portfolio Loans and Leases to Held-for-sale	0	0	144
Affordable Housing Program Obligation, Period Increase (Decrease)	7,000	9,000	9,000
Consumer
Adjustments to reconcile net income to net cash provided by operating activities:
Increase in prepaid dealer premiums	(4,350)	(5,733)	(2,836)
Mortgages [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sale of loans in secondary market	5,014	5,517	4,027
Foreclosed Asset [Domain]
Changes in assets and liabilities:
Decrease (increase) in other assets	(5,553)	0	0
Held-to-maturity Securities [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Realized net investment security gains			(88)
Treasury Stock, Common [Member]
Financing activities
Repurchase of treasury shares	$ (7,378)	$ 0	$ (6,058)

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies The following is a summary of significant accounting policies followed in the preparation of the consolidated financial statements: Principles of Consolidation The consolidated financial statements include the accounts of Park National Corporation and its subsidiaries (“Park”, the “Company” or the “Corporation”). Material intercompany accounts and transactions have been eliminated. Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles ("GAAP") requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Reclassifications Certain prior year amounts have been reclassified to conform with the current year presentation. These reclassifications had no impact on net income or shareholders' equity. Restrictions on Cash and Due from Banks The Corporation’s national bank subsidiary, The Park National Bank ("PNB"), is required to maintain average reserve balances with the Federal Reserve Bank of Cleveland. The average required reserve balance was approximately $64.8 million at December 31, 2017 and $51.6 million at December 31, 2016 . No other compensating balance arrangements were in existence at December 31, 2017 . Investment Securities Investment securities are classified upon acquisition into one of three categories: held-to-maturity ("HTM"), available-for-sale ("AFS"), or trading (see Note 4 - Investment Securities). HTM securities are those securities that the Corporation has the positive intent and ability to hold to maturity and are recorded at amortized cost. AFS securities are those securities that would be available to be sold in the future in response to the Corporation’s liquidity needs, changes in market interest rates, and asset-liability management strategies, among other reasons. AFS securities are reported at fair value, with unrealized holding gains and losses excluded from earnings but included in other comprehensive income (loss), net of applicable income taxes. The Corporation did not hold any trading securities during any period presented. AFS and HTM securities are evaluated quarterly for potential other-than-temporary impairment. Management considers the facts related to each security including the nature of the security, the amount and duration of the loss, the credit quality of the issuer, the expectations for that security’s performance and whether Park intends to sell, or it is more likely than not that Park will be required to sell, a security in an unrealized loss position before recovery of its amortized cost basis. Declines in the value of equity securities that are considered to be other-than-temporary are recorded as a charge to earnings in the Consolidated Statements of Income. Declines in the value of debt securities that are considered to be other-than-temporary are separated into (1) the amount of the total impairment related to credit loss and (2) the amount of the total impairment related to all other factors. The amount of the total other-than-temporary impairment related to the credit loss is recognized in earnings. The amount of the total other-than-temporary impairment related to all other factors is recognized in other comprehensive income (loss), net of income tax. Interest income from investment securities includes amortization of purchase premium or discount. Premiums and discounts on securities are amortized on the level-yield method without anticipating prepayments, except for mortgage-backed securities where prepayments are anticipated. Gains and losses realized on the sale of investment securities are recorded on the trade date and determined using the specific identification basis. Federal Home Loan Bank ("FHLB") and Federal Reserve Bank of Cleveland ("FRB") Stock Park’s national bank subsidiary, PNB, is a member of the FHLB. Additionally, PNB is a member of the FRB. Members are required to own a certain amount of stock based on their level of borrowings and other factors and may invest in additional amounts. FHLB stock and FRB stock are classified as restricted securities and are carried at their redemption value within other investment securities on the Consolidated Balance Sheets. Impairment is evaluated based on the ultimate recovery of par value. Both cash and stock dividends are reported as income. Bank Owned Life Insurance Park has purchased insurance policies on the lives of directors and certain key officers. Bank owned life insurance is recorded at its cash surrender value (or the amount that can be realized). Loans Held for Sale Park has elected the fair value option for mortgage loans held for sale, which are carried at their fair value as of each balance sheet date. Mortgage Banking Derivatives Commitments to fund mortgage loans (interest rate locks) to be sold into the secondary market and forward commitments for the future delivery of these mortgage loans are accounted for as free standing derivatives. The fair value of the interest rate lock is recorded at the time the commitment to fund the mortgage loan is executed and is adjusted for the expected exercise of the commitment before the loan is funded. In order to hedge the change in interest rates resulting from its commitments to fund the loans, the Company interest into forward commitments for the future delivery of mortgage loans when interest rate locks are entered into. Fair value of these mortgage derivatives are estimated based on change in mortgage interest rates from the date the interest on the loan is locked. Changes in the fair values of these derivatives are included in other service income in the Consolidated Statements of Income. Loans Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff, are reported at their outstanding principal balances adjusted for any charge-offs, any nonaccrual interest payments applied to principal, any deferred fees or costs on originated loans, and any unamortized premiums or discounts on purchased loans. Interest income is accrued on the unpaid principal balance. Late charges on loans are recognized as income when they are collected. Net loan origination fees and costs are deferred and recognized in interest income using the level-yield method without anticipating prepayments. Commercial loans include: (1) commercial, financial and agricultural loans; (2) commercial real estate loans; (3) those commercial loans in the real estate construction loan segment; and (4) those commercial loans in the residential real estate loan segment. Consumer loans include: (1) mortgage and installment loans included in the real estate construction segment; (2) mortgage, home equity lines of credit ("HELOCs"), and installment loans included in the residential real estate segment; and (3) all loans included in the consumer segment. Generally, commercial loans are placed on nonaccrual status at 90 days past due and consumer and residential mortgage loans are placed on nonaccrual status at 120 days past due. Commercial loans placed on nonaccrual status are considered impaired (see Note 5 - Loans). For loans which are on nonaccrual status, it is Park’s policy to reverse interest previously accrued on the loans against interest income. Interest on such loans may be recorded on a cash basis and be included in earnings only when Park expects to receive the entire recorded investment of the loan. Park’s charge-off policy for commercial loans requires management to establish a specific reserve or record a charge-off when collection is in doubt or it is probable a loss has been incurred and there is, or likely will be, a collateral shortfall related to the estimated value of the collateral securing the loan. The Company’s charge-off policy for consumer loans is dependent on the class of the loan. Residential mortgage loans, HELOCs, and consumer loans secured by residential real estate are typically charged down to the value of the collateral, less estimated selling costs, at 180 days past due. The charge-off policy for other consumer loans, primarily installment loans, requires a monthly review of delinquent loans and a complete charge-off for any account that reaches 120 days past due. The delinquency status of a loan is based on contractual terms and not on how recently payments have been received. Loans may be removed from nonaccrual status when loan payments have been received to cure the delinquency status, the borrower has demonstrated the ability to maintain current payment status in accordance with the loan agreement and the loan is deemed to be well-secured by management. A description of each segment of the loan portfolio, along with the risk characteristics of each segment, is included below: Commercial, financial and agricultural: Commercial, financial and agricultural ("C&I") loans are made for a wide variety of general corporate purposes, including financing for commercial and industrial businesses, financing for equipment, inventories and accounts receivable, acquisition financing, commercial leasing, and to consumer finance companies. The term of each commercial loan varies by its purpose. Repayment terms are structured such that commercial loans will be repaid within the economic useful life of the underlying asset. The commercial loan portfolio of Park’s current subsidiaries includes loans to a wide variety of corporations and businesses across many industrial classifications in the 29 Ohio counties where PNB and its divisions operate, with the exception of nationwide aircraft loans and nationwide asset based lending to consumer finance companies. The primary industries represented by these customers include real estate rental and leasing, finance and insurance, construction, agriculture, forestry, fishing and hunting, manufacturing, retail trade, health care and other services. Risk of loss on C&I loans largely depends upon general economic cycles, as they may adversely impact certain industries, competency of the borrower's management team, the quality of the underlying assets supporting the loans including accounts receivable, inventory, and equipment, and the accuracy of the borrower's financial reporting. Such risks are mitigated by generally requiring the borrower's owners to guaranty the loans. Commercial real estate: Commercial real estate (“CRE”) loans include mortgage loans to developers and owners of commercial real estate. The lending policy for CRE loans is designed to address the unique risk attributes of CRE lending. The collateral for these CRE loans is the underlying commercial real estate. Risk of loss on CRE loans largely depends upon the cash flow of the properties which is influenced by the amount of vacancy experienced by the underlying real estate, the credit capacity of the tenants occupying the underlying real estate, and general economic trends as they may adversely impact the value of the property. These risks are mitigated by generally requiring personal guaranties of the owners of the properties and by requiring appraisals pursuant to government regulations. Construction real estate : The Company defines construction loans as both commercial construction loans and residential construction loans where the loan proceeds are used exclusively for the improvement of real estate as to which the Company holds a mortgage. Construction loans may be in the form of a permanent loan or a short-term construction loan, depending on the needs of the individual borrower. Construction financing is generally considered to involve a higher degree of risk of loss than long-term financing on improved, occupied real estate. Risk of loss on a construction loan depends largely upon the accuracy of the initial estimate of the property’s value at completion of construction and the estimated cost (including interest) of construction. If the estimate of construction cost proves to be inaccurate, the PNB division making the loan may be required to advance funds beyond the amount originally committed to permit completion of the project. If the estimate of value proves inaccurate, the PNB division may be confronted, at or prior to the maturity of the loan, with a project having a value insufficient to assure full repayment, should the borrower default. In the event that a default on a construction loan occurs and foreclosure follows, the PNB division must take control of the project and attempt to either arrange for completion of construction or dispose of the unfinished project. Additional risk exists with respect to loans made to developers who do not have a buyer for the property, as the developer may lack funds to pay the loan if the property is not sold upon completion. PNB and its divisions attempt to reduce such risks on loans to developers by requiring personal guarantees and reviewing current personal financial statements and tax returns as well as other projects undertaken by the developer. Residential real estate: The Company defines residential real estate loans as first mortgages on individuals’ primary residences or second mortgages of individuals’ primary residences in the form of HELOCs or installment loans. Credit approval for residential real estate loans requires demonstration of sufficient income to repay the principal and interest and the real estate taxes and insurance, stability of employment, an established credit record and an appraised value of the real estate securing the loan. Residential real estate loans typically have longer terms and higher balances with lower yields as compared to consumer loans, but generally carry lower risks of default. The Dodd-Frank Wall Street Reform and Consumer Protection Act requires creditors to make a reasonable and good faith determination of a consumer's ability to repay any consumer credit transaction secured by a dwelling. Documentation and verification of income within defined time frames and not-to-exceed limits is basis for affirming ability to repay. Risk of loss largely depends upon factors affecting the borrower's ability to repay as well as the general economic trends as they may adversely impact the value of the property. These risks are mitigated by completing a comprehensive underwriting of the borrower and by requiring appraisals pursuant to government regulations. Consumer: The Company originates direct and indirect consumer loans, primarily automobile loans, to customers in its primary market areas. Credit approval for consumer loans requires income sufficient to repay principal and interest due, stability of employment, an established credit record and sufficient collateral for secured loans. Consumer loans typically have shorter terms and lower balances with higher yields as compared to real estate mortgage loans, but generally carry higher risks of default. Consumer loan collections are dependent on the borrower’s financial stability, and thus are more likely to be affected by adverse personal circumstances. Allowance for Loan Losses ("ALLL") The allowance for loan losses is that amount believed adequate to absorb probable incurred credit losses in the loan portfolio based on management’s evaluation of various factors. The determination of the allowance requires significant estimates, including the timing and amounts of expected cash flows on impaired loans, consideration of current economic conditions, and historical loss experience pertaining to pools of homogeneous loans, all of which may be susceptible to change. The allowance is increased through a provision for loan losses that is charged to earnings based on management’s quarterly evaluation of the factors previously mentioned and is reduced by charge-offs, net of recoveries. The allowance for loan losses includes both (1) an estimate of loss based on historical loss experience within both commercial and consumer loan categories with similar characteristics (“statistical allocation”) and (2) an estimate of loss based on an impairment analysis of each commercial loan that is considered to be impaired (“specific allocation”). Included in the statistical allocation is a reserve for troubled debt restructurings ("TDRs") within the consumer loan portfolio. Management performs a periodic evaluation to ensure the reserve calculated utilizing the statistical allocation is consistent with a reserve calculated under Accounting Standards Codification ("ASC") 310-10 - Receivables . In calculating the allowance for loan losses, management believes it is appropriate to consider historical loss rates that are comparable to the current period being analyzed, giving consideration to losses experienced over a full cycle. For the historical loss factor at December 31, 2017 , the Company utilized an annual loss rate (“historical loss experience”), calculated based on an average of the net charge-offs and the annual change in specific reserves for impaired commercial loans, experienced during 2010 through 2017 within the individual segments of the commercial and consumer loan categories. The 96 month historical loss period captures all annual periods subsequent to June 2009, the end of the most recent recession, thus encompassing the full economic cycle to date. The loss factor applied to Park’s consumer loan portfolio as of December 31, 2017 was based on the historical loss experience over the preceding 96 months, plus an additional judgmental reserve, increasing the total allowance for loan loss coverage in the consumer loan portfolio to approximately 1.92 years of historical losses, compared to 1.95 years at December 31, 2016 . Historical loss experience over the preceding 96 months for the consumer loan portfolio was 0.34% for both 2017 and 2016. The loss factor applied to Park’s commercial loan portfolio as of December 31, 2017 was based on the historical loss experience over the preceding 96 months, plus additional reserves for consideration of (1) a loss emergence period factor, (2) a loss migration factor and (3) a judgmental or environmental loss factor. These additional reserves increased the total allowance for loan loss coverage in the commercial loan portfolio to approximately 3.24 years of historical losses at December 31, 2017, compared to 3.20 years at December 31, 2016 . Historical loss experience over the preceding 96 months for the commercial loan portfolio was 0.37% for 2017 and 0.39% for 2016. Park’s commercial loans are individually risk graded. If loan downgrades occur, the probability of default increases and accordingly management allocates a higher percentage reserve to those accruing commercial loans graded special mention and substandard. The judgmental increases discussed above incorporate management’s evaluation of the impact of environmental qualitative factors which pose additional risks and assign a component of the allowance for loan losses in consideration of these factors. Such environmental factors include: national and local economic trends and conditions; experience, ability and depth of lending management and staff; effects of any changes in lending policies and procedures; and levels of, and trends in, consumer bankruptcies, delinquencies, impaired loans and charge-offs and recoveries. GAAP requires a specific allocation to be established as a component of the allowance for loan losses for certain loans when it is probable that all amounts due pursuant to the contractual terms of the loans will not be collected, and the recorded investment in the loans exceeds their measure of impairment. Management considers the following related to commercial loans when determining if a loan should be considered impaired : (1) current debt service coverage levels of the borrowing entity; (2) payment history over the most recent 12-month period; (3) other signs of deterioration in the borrower’s financial situation, such as changes in credit scores; and (4) consideration of global cash flows of financially sound guarantors that have previously supported loan payments. The recorded investment is the balance of the loan, plus accrued interest receivable, both as of the end of the year. Impairment is measured using either the present value of expected future cash flows based upon the initial effective interest rate on the loan, or the fair value of the collateral. If a loan is considered to be collateral dependent, the fair value of collateral, less estimated selling costs, is used to measure impairment. Troubled Debt Restructuring Management classifies loans as TDRs when a borrower is experiencing financial difficulty and Park has granted a concession. In order to determine whether a borrower is experiencing financial difficulty, an evaluation is performed of the probability that the borrower will be in payment default on any of the borrower's debt in the foreseeable future without the modification. This evaluation is performed under the Company’s internal underwriting policy. Management’s policy is to modify loans by extending the term or by granting a temporary or permanent contractual interest rate below the market rate, not by forgiving debt. A court's discharge of a borrower's debt in a Chapter 7 bankruptcy is considered a concession when the borrower does not reaffirm the discharged debt. TDRs are measured at the present value of estimated future cash flows using the loan’s effective rate at inception, or if a TDR is considered to be a collateral dependent loan, the loan is reported, net, at the fair value of the collateral. Commercial TDRs are separately identified for impairment disclosures. Premises and Equipment Land is carried at cost and is not subject to depreciation. Premises and equipment are carried at cost, less accumulated depreciation and amortization. Depreciation is generally provided on the straight-line method over the estimated useful lives of the related assets. Leasehold improvements are amortized over the shorter of the remaining lease period or the estimated useful lives of the improvements. Upon the sale or other disposal of an asset, the cost and related accumulated depreciation are removed from the accounts and the resulting gain or loss is recognized. Maintenance and repairs are charged to expense as incurred while renewals and improvements that extend the useful life of an asset are capitalized. Premises and equipment are evaluated for impairment whenever events or changes in circumstances indicate that the carrying amount of a particular asset may not be recoverable. The range of depreciable lives over which premises and equipment are being depreciated are: Buildings 30 Years Equipment, furniture and fixtures 3 to 12 Years Leasehold improvements 1 to 10 Years Other Real Estate Owned ("OREO") Management transfers a loan to OREO at the time that Park takes deed/title to the asset. OREO is initially recorded at fair value less anticipated selling costs (net realizable value), establishing a new cost basis, and consists of property acquired through foreclosure and real estate held for sale. If the net realizable value is below the carrying value of the loan at the date of transfer, the difference is charged to the allowance for loan losses. These assets are subsequently accounted for at the lower of cost or fair value less costs to sell. Subsequent changes in the value of real estate are classified as OREO valuation adjustments, are reported as adjustments to the carrying amount of OREO and are recorded within “Other income”. In certain circumstances where management believes the devaluation may not be permanent in nature, Park utilizes a valuation allowance to record OREO devaluations, which is also expensed through “Other income”. Costs relating to development and improvement of such properties are capitalized (not in excess of fair value less estimated costs to sell) and costs relating to holding the properties are charged to "Other expense". Foreclosed Assets Foreclosed assets include non-real estate assets where Park, as creditor, has received physical possession of a borrower’s assets, regardless of whether formal foreclosure proceedings take place. Additionally, troubled debt restructurings in which Park obtains one of more of the debtor’s non-real estate assets in place of all or part of the receivable are accounted for as foreclosed assets. Foreclosed assets are initially recorded as fair value less costs to sell when acquired, establishing a new cost basis. Operating costs after acquisition are expensed. As of December 31, 2017 and 2016, Park had $5.5 million and $0.6 million , respectively, of foreclosed assets included within “Other assets.” Mortgage Servicing Rights ("MSR") When Park sells mortgage loans with servicing rights retained, servicing rights are recorded at fair value with the income statement effect recorded in "Other service income." Capitalized servicing rights are amortized in proportion to and over the period of the estimated future servicing income of the underlying loan and are included within “Other service income”. Mortgage servicing rights are assessed for impairment periodically, based on fair value, with any impairment recognized through a valuation allowance. The fair value of mortgage servicing rights is determined by discounting estimated future cash flows from the servicing assets, using market discount rates and expected future prepayment rates. In order to calculate fair value, the sold loan portfolio is stratified into homogeneous pools of like categories. (See Note 24 - Loan Servicing.) Fees received for servicing mortgage loans owned by investors are based on a percentage of the outstanding monthly principal balance of such loans and are included in income as loan payments are received. The cost of servicing loans is charged to expense as incurred to "Other service income". Goodwill Goodwill represents the excess of the purchase price over net identifiable tangible and intangible assets acquired in a purchase business combination. Goodwill and indefinite-lived intangible assets are not amortized to expense, but are subject to impairment tests annually, or more frequently, if events or changes in circumstances indicate that the asset might be impaired, by assessing qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If after assessing these events or circumstances, it is concluded that it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then performing additional analysis is unnecessary. If the carrying amount of the goodwill exceeds the fair value, an impairment charge must be recorded in an amount equal to the excess, not to exceed the total goodwill allocated to the reporting unit. Management considers several factors when performing the annual impairment tests on goodwill. The factors considered include the operating results for the particular Park segment for the past year and the operating results budgeted for the current year (including multi-year projections), the deposit and loan totals of the Park segment and the economic conditions in the markets served by the Park segment. At December 31, 2017, the goodwill remaining on Park's Consolidated Balance Sheet consisted entirely of goodwill at PNB. (See Note 27 - Segment Information for operating segment results.) Park evaluates goodwill for impairment on April 1 of each year, with financial data as of March 31. Based on the analysis performed as of April 1, 2017, the Company determined that goodwill for Park’s national bank subsidiary (PNB) was not impaired. There have been no subsequent circumstances or events triggering an additional evaluation. Goodwill in the amount of $72.3 million was recorded at each of December 31, 2017, 2016, and 2015. Consolidated Statement of Cash Flows Cash and cash equivalents include cash and cash items, amounts due from banks and money market instruments. Generally, money market instruments are purchased and sold for one-day periods. Loss Contingencies and Guarantees Loss contingencies, including claims and legal actions arising in the ordinary course of business, are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated. Income Taxes The Corporation accounts for income taxes using the asset and liability approach. Under this method, deferred tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. To the extent that Park does not consider it more likely than not that a deferred tax asset will be recovered, a valuation allowance is recorded. All positive and negative evidence is reviewed when determining how much of a valuation allowance is recognized on a quarterly basis. A valuation allowance, if needed, reduces deferred tax assets to the amount expected to be realized. An uncertain tax position is recognized as a benefit only if it is “more-likely-than-not” that the tax position would be sustained in a tax examination being presumed to occur. The benefit recognized for a tax position that meets the “more-likely-than-not” criteria is measured based on the largest benefit that is more than 50 percent likely to be realized, taking into consideration the amounts and probabilities of the outcome upon settlement. For tax positions not meeting the “more-likely-than-not” test, no tax benefit is recorded. Park recognizes any interest and penalties related to income tax matters in income tax expense. Treasury Shares The purchase of Park’s common shares to be held in treasury is recorded at cost. At the date of retirement or subsequent reissuance, the treasury shares account is reduced by the weighted average cost of the common shares retired or reissued. Comprehensive Income Comprehensive income consists of net income and other comprehensive income (loss). Other comprehensive income (loss) includes unrealized gains and losses on securities available for sale, and changes in the funded status of the Company’s defined benefit pension plan, which are also recognized as separate components of equity. Share-Based Compensation Compensation cost is recognized for restricted stock units and stock awards issued to employees and directors, respectively, based on the fair value of these awards at the date of grant. The market price of Park’s common shares at the date of grant is used to estimate the fair value of restricted stock units and stock awards. Compensation cost is recognized over the required service period, generally defined as the vesting period and is recorded in "Salaries" expense. (See Note 17-Share-Based Compensation.) Loan Commitments and Related Financial Instruments Financial instruments include off‑balance sheet credit instruments, such as commitments to make loans and commercial letters of credit, issued to meet customer financing needs. The face amount for these items represents the exposure to loss, before considering customer collateral or ability to repay. Such financial instruments are recorded when they are funded. Fair Value Measurement Fair values of financial instruments are estimated using relevant market information and other assumptions, as more fully disclosed in Note 25 - Fair Value. Fair value estimates involve uncertainties and matters of significant judgment regarding interest rates, credit risk, prepayments, and other factors, especially in the absence of broad markets for particular items. Changes in assumptions or in market conditions could significantly affect the estimates. Transfers of Financial Assets Transfers of financial assets are accounted for as sales, when control over the assets has been relinquished. Control over transferred assets is deemed to be surrendered when the assets have been isolated from the Company, the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. Retirement Plans Pension expense is the net of service and interest cost, return on plan assets and amortization of gains and losses not immediately recognized. Employee KSOP plan expense is the amount of matching contributions to Park's employees stock ownership plan. Deferred compen

Adoption of New Accounting Pron

Adoption of New Accounting Pronouncements and Issued Not Yet Effective Accounting Standards Adoption of New Accounting Pronouncements	12 Months Ended
	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	Adoption of New Accounting Pronouncements and Issued Not Yet Effective Accounting Standards The following is a summary of new accounting pronouncements, new laws impacting Park's consolidated financial statements, and issued not yet effective accounting standards: Adoption of New Accounting Pronouncements ASU 2016-09 - Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting: In March 2016, FASB issued ASU 2016-09 - Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting . This ASU provides simplification for several aspects of accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The new guidance is effective for annual reporting periods and interim reporting periods within those annual periods, beginning after December 15, 2016. Early adoption was permitted. The adoption of this guidance on January 1, 2017 did not have a material impact on Park's consolidated financial statements. ASU 2017-01 – Business Combinations (Topic 805): Clarifying the Definition of a Business: In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business . This ASU clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The new guidance is effective for annual reporting periods and interim reporting periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted. The early adoption of this guidance on October 1, 2017 did not have a material impact on Park's consolidated financial statements. Park will apply this guidance to all future transactions. ASU 2017-04 - Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment: In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. This ASU eliminates Step 2 from the goodwill impairment test. Instead, under the new guidance, an entity should perform its annual goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An impairment charge would be recognized for the amount by which the carrying amount exceeds the reporting unit's fair value. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The early adoption of this guidance with Park's April 1, 2017 annual goodwill impairment test did not have an impact on Park's consolidated financial statements. Issued Not Yet Effective Accounting Standards ASU 2014-09 - Revenue from Contracts with Customers (Topic 606): In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606). This ASU creates a new topic, Topic 606, to provide guidance on revenue recognition for entities that enter into contracts with customers to transfer goods or services or enter into contracts for the transfer of nonfinancial assets. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Additional disclosures are required to provide quantitative and qualitative information regarding the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. The adoption of this guidance on January 1, 2018 did not have a material impact on Park's consolidated financial statements. However, the adoption of this standard will result in additional disclosures beginning with the first quarter 2018 Form 10-Q. ASU 2016-01 - Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. In January 2016, the FASB issued ASU 2016-01 - Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. Changes to the current U.S. GAAP model primarily affect the accounting for equity investments, financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. In addition, this ASU clarifies guidance related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on AFS securities. The new guidance is effective for annual reporting periods and interim reporting periods within those annual periods, beginning after December 15, 2017. The adoption of this guidance on January 1, 2018 did not have a material impact on Park's consolidated financial statements, but will impact the fair value disclosures in Note 25 beginning with the first quarter 2018 Form 10-Q. ASU 2016-02 - Leases (Topic 842): In February 2016, the FASB issued ASU 2016-02 - Leases (Topic 842) . This ASU will require all organizations that lease assets to recognize on the balance sheet the assets and liabilities for the rights and obligations created by those leases. Additional qualitative and quantitative disclosures will be required so that users can understand more about the nature of an entity’s leasing activities. The new guidance is effective for annual reporting periods and interim reporting periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted. Management is currently analyzing data on leased assets. The adoption of this guidance is expected to increase both assets and liabilities, but is not expected to have a material impact on Park's consolidated statement of income. ASU 2016-13 - Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments: In June 2016, FASB issued ASU 2016-13 - Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . The new guidance replaces the incurred loss model with an expected loss model, which is referred to as the current expected credit loss ("CECL") model. The CECL model is applicable to the measurement of credit losses on financial assets measured at amortized cost, including loan receivables, HTM debt securities, and reinsurance receivables. It also applies to off-balance sheet credit exposures not accounted for as insurance (loan commitments, standby letters of credit, financial guarantees, and other similar instruments) and net investments in leases recognized by a lessor. The CECL model requires an entity to estimate credit losses over the life of an asset or off-balance sheet exposure. The new guidance is effective for annual reporting periods and interim reporting periods within those annual periods, beginning after December 15, 2019. Early adoption is permitted for annual reporting periods and interim reporting periods within those annual periods, beginning after December 15, 2018. Management is currently evaluating the impact of the adoption of this guidance on Park's consolidated financial statements. We anticipate that the adoption of the CECL model will result in a material increase to Park's allowance for loan losses. Management has established a committee to oversee the implementation of the CECL model and is currently in the process of implementing a software solution to assist in the adoption of this ASU. Management plans to run our current allowance model and a CECL model concurrently for 12 months prior to the adoption of this guidance on January 1, 2020. ASU 2016-15 - Statement of Cash Flows (Topic 203): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force): In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 203): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) . This ASU provides guidance on eight specific cash flow issues where current GAAP is either unclear or does not include specific guidance. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. As such transactions arise, management will utilize the updated guidance within Park’s consolidated statements of cash flows. ASU 2017-07 - Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost: In March 2017, the FASB issued ASU 2017-07 - Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. This ASU requires that an employer report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the income statement separately from the service cost component. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. The adoption of this guidance on January 1, 2018 did not have a material impact on Park's consolidated financial statements. ASU 2017-08 - Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities: In March 2017, the FASB issued ASU 2017-08 - Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities. This ASU amends the amortization period for certain purchased callable debt securities held at a premium. It shortens the amortization period for the premium to the earliest call date. Under current U.S. GAAP, premiums on callable debt securities generally are amortized to the maturity date. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted for interim or annual periods. The adoption of this guidance is not expected to have a material impact on Park's consolidated financial statements. ASU 2017-09 - Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting: In May 2017, the FASB issued ASU 2017-09 - Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting. This ASU amends the guidance concerning which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. The adoption of this guidance on January 1, 2018 did not impact Park's consolidated financial statements. ASU 2017-12 - Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities: In August 2017, the FASB issued ASU 2017-12 - Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. This ASU amends the current guidance with the objective of improving the financial reporting of hedging relationships to better portray the economic results of an entity's risk management activities in its financial statements. In addition, this ASU amends the current guidance to simplify the application of the hedge accounting guidance. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted for interim or annual periods. The adoption of this guidance is not expected to have a material impact on Park's consolidated financial statements. Park is considering the early adoption of this guidance. ASU 2018-02 - Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income : In February 2018, the FASB issued ASU 2018-02 - Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. This ASU allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects, resulting from the newly - enacted federal corporate income tax rate. The amount of the reclassification is the difference between the historical federal corporate income tax rate and the newly - enacted 21% federal corporate income tax rate. The guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted for interim or annual periods. The early adoption of this guidance on January 1, 2018 resulted in a $3.8 million increase to Park's accumulated other comprehensive loss and a $3.8 million increase to retained earnings, which will be reflected in Park's first quarter 2018 Consolidated Balance Sheet.

Organization

Organization	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization Park National Corporation is a financial holding company headquartered in Newark, Ohio. Through its national bank subsidiary, PNB, Park is engaged in a general commercial banking and trust business, primarily in Ohio, with the exception of nationwide aircraft loans and nationwide asset based lending to consumer finance companies. PNB operates through eleven banking divisions with the Park National Bank Division headquartered in Newark, Ohio, the Fairfield National Bank Division headquartered in Lancaster, Ohio, The Park National Bank of Southwest Ohio & Northern Kentucky Division headquartered in Cincinnati, Ohio, the First-Knox National Bank Division headquartered in Mount Vernon, Ohio, the Farmers Bank Division headquartered in Loudonville, Ohio, the Security National Bank Division headquartered in Springfield, Ohio, the Unity National Bank Division headquartered in Piqua, Ohio, the Richland Bank Division headquartered in Mansfield, Ohio, the Century National Bank Division headquartered in Zanesville, Ohio, the United Bank, N.A. Division headquartered in Bucyrus, Ohio and the Second National Bank Division headquartered in Greenville, Ohio. The Farmers Bank Division will merge into the First-Knox Bank Division effective March 30, 2018, and thereafter, Park National Bank will have ten divisions. A wholly-owned subsidiary of Park, GFSC is a consumer finance company located in Central Ohio. Through February 16, 2012, Park operated a second banking subsidiary, Vision Bank ("Vision"), which was engaged in a general commercial banking business, primarily in Baldwin County, Alabama and the panhandle of Florida. Promptly following the sale of the Vision business to Centennial Bank (a wholly-owned subsidiary of HomeBanc Shares, Inc.), Vision surrendered its Florida banking charter to the Florida Office of Financial Regulation and became a non-bank Florida corporation. Vision (the Florida corporation) merged with and into a wholly-owned, non-bank subsidiary of Park, SEPH, with SEPH being the surviving entity. SEPH holds the remaining assets and liabilities retained by Vision subsequent to the sale. SEPH also holds OREO that had previously been transferred to SEPH from Vision. SEPH's assets consist primarily of performing and nonperforming loans and OREO. This segment represents a run off portfolio of the legacy Vision assets. All of the Ohio-based banking divisions provide the following principal services: the acceptance of deposits for demand, savings and time accounts; commercial, industrial, consumer and real estate lending, including installment loans, credit cards, home equity lines of credit; trust services; cash management; safe deposit operations; electronic funds transfers and a variety of additional banking-related services. See Note 27 - Segment Information for financial information on the Corporation’s operating segments.

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investments Securities	Investment Securities The amortized cost and fair value of investment securities are shown in the following tables. Management performs a quarterly evaluation of investment securities for any other-than-temporary impairment. During 2017 , 2016 and 2015, there were no investment securities deemed to be other-than-temporarily impaired. Investment securities at December 31, 2017 and December 31, 2016 were as follows: (In thousands) Amortized Cost Gross Unrealized/Unrecognized Holding Gains Gross Unrealized/Unrecognized Holding Losses Estimated Fair Value 2017: Securities Available-for-Sale Obligations of U.S. Treasury and other U.S. Government sponsored entities $ 245,000 $ — $ 2,280 $ 242,720 U.S. Government sponsored entities’ asset-backed securities 852,645 4,645 8,129 849,161 Other equity securities 675 1,260 — 1,935 Total $ 1,098,320 $ 5,905 $ 10,409 $ 1,093,816 2017: Securities Held-to-Maturity Obligations of states and political subdivisions $ 300,412 $ 6,575 $ 713 $ 306,274 U.S. Government sponsored entities’ asset-backed securities 56,785 758 38 57,505 Total $ 357,197 $ 7,333 $ 751 $ 363,779 (In thousands) Amortized Cost Gross Unrealized/Unrecognized Holding Gains Gross Unrealized/Unrecognized Holding Losses Estimated Fair Value 2016: Securities Available-for-Sale Obligations of U.S. Treasury and other U.S. Government sponsored entities $ 270,000 $ — $ 2,467 $ 267,533 U.S. Government sponsored entities’ asset-backed securities 991,642 5,372 9,842 987,172 Other equity securities 1,119 2,315 — 3,434 Total $ 1,262,761 $ 7,687 $ 12,309 $ 1,258,139 2016: Securities Held-to-Maturity Obligations of states and political subdivisions $ 188,622 $ 977 $ 5,148 $ 184,451 U.S. Government sponsored entities’ asset-backed securities 71,211 1,097 87 72,221 Total $ 259,833 $ 2,074 $ 5,235 $ 256,672 Park’s U.S. Government sponsored entities' asset-backed securities consisted of 15 -year mortgage-backed securities and collateralized mortgage obligations ("CMOs"). At December 31, 2017 , the amortized cost of Park’s AFS mortgage-backed securities was $455.3 million and there were no HTM mortgage-backed securities within Park's investment portfolio. At December 31, 2017 , the amortized cost of Park's AFS and HTM CMOs was $397.3 million and $56.8 million , respectively. The following table provides detail on investment securities with unrealized/unrecognized losses aggregated by investment category and length of time the individual securities had been in a continuous loss position at December 31, 2017 and December 31, 2016 : Less than 12 Months 12 Months or Longer Total (In thousands) Fair Value Unrealized/Unrecognized Losses Fair Value Unrealized/Unrecognized Losses Fair Value Unrealized/Unrecognized Losses 2017: Securities Available-for-Sale Obligations of U.S. Treasury and other U.S. Government sponsored entities $ 24,931 $ 70 $ 217,789 $ 2,210 $ 242,720 $ 2,280 U.S. Government sponsored entities' asset-backed securities 236,924 2,786 318,797 5,343 555,721 8,129 Total $ 261,855 $ 2,856 $ 536,586 $ 7,553 $ 798,441 $ 10,409 2017: Securities Held-to-Maturity Obligations of states and political subdivisions $ 26,644 $ 194 $ 45,498 $ 519 $ 72,142 $ 713 U.S. Government sponsored entities’ asset-backed securities 7,331 38 — — 7,331 38 Total $ 33,975 $ 232 $ 45,498 $ 519 $ 79,473 $ 751 Less than 12 Months 12 Months or Longer Total (In thousands) Fair Value Unrealized/Unrecognized Losses Fair Value Unrealized/Unrecognized Losses Fair Value Unrealized/Unrecognized Losses 2016: Securities Available-for-Sale Obligations of U.S. Treasury and other U.S. Government sponsored entities $ 247,695 $ 2,305 $ 19,838 $ 162 $ 267,533 $ 2,467 U.S. Government sponsored entities' asset-backed securities 612,321 9,473 27,325 369 639,646 9,842 Total $ 860,016 $ 11,778 $ 47,163 $ 531 $ 907,179 $ 12,309 2016: Securities Held-to-Maturity Obligations of states and political subdivisions $ 134,909 $ 5,148 $ — $ — $ 134,909 $ 5,148 U.S. Government sponsored entities' asset-backed securities $ — $ — $ 7,564 $ 87 $ 7,564 $ 87 Total $ 134,909 $ 5,148 $ 7,564 $ 87 $ 142,473 $ 5,235 Management does not believe any individual unrealized/unrecognized loss as of December 31, 2017 or 2016 represented an other-than-temporary impairment. The unrealized/unrecognized losses on debt securities are primarily the result of interest rate changes. These conditions will not prohibit Park from receiving its contractual principal and interest payments on these debt securities. The fair value of these debt securities is expected to recover as payments are received on these securities and they approach maturity. Should the impairment of any of these securities become other-than-temporary, the cost basis of the investment will be reduced and the resulting loss attributable to credit will be recognized in net income in the period the other-than-temporary impairment is identified. Other investment securities (as shown on the Consolidated Balance Sheets) consist of stock investments in the FHLB, the FRB and other equities carried at cost. The FHLB and FRB restricted stock investments are carried at their redemption value. Park owned $50.1 million of FHLB stock and $8.2 million of FRB stock at both December 31, 2017 and December 31, 2016 . Park owned $3.5 million of other equities carried at cost at both December 31, 2017 and December 31, 2016 . The amortized cost and estimated fair value of investments in debt securities at December 31, 2017 , are shown in the following table by contractual maturity, except for asset-backed securities, which are shown as a single total, due to the unpredictability of the timing in principal repayments. (In thousands) Amortized Cost Estimated Fair Value Tax Equivalent Yield (1) Securities Available-for-Sale U.S. Treasury and other U.S. Government sponsored entities’ notes: Due within one year $ 120,000 $ 119,499 1.14 % Due one through five years 125,000 123,221 1.29 % Total $ 245,000 $ 242,720 1.22 % U.S. Government sponsored entities’ asset-backed securities $ 852,645 $ 849,161 2.09 % Securities Held-to-Maturity Obligations of states and political subdivisions Due five through ten years $ 2,454 $ 2,462 3.61 % Due greater than ten years $ 297,958 $ 303,812 4.46 % Total $ 300,412 $ 306,274 4.46 % U.S. Government sponsored entities’ asset-backed securities $ 56,785 $ 57,505 3.16 % (1) The tax equivalent yield for obligations of states and political subdivisions includes the effects of a taxable equivalent adjustment using a 35% rate. The taxable equivalent adjustment was $3.9 million for the year ended December 31, 2017. All of Park’s securities shown in the above table as U.S. Treasury and other U.S. Government sponsored entities' notes are callable notes. These callable securities have a final maturity of 3 months to 2.5 years. The remaining weighted average life of the entire investment portfolio is 4.4 years. At December 31, 2017 , investment securities with an amortized cost of $317 million were pledged for government and trust department deposits, $215 million were pledged to secure repurchase agreements and $25 million were pledged as collateral for FHLB advance borrowings. At December 31, 2016 , investment securities with an amortized cost of $343 million were pledged for government and trust department deposits, $569 million were pledged to secure repurchase agreements and $25 million were pledged as collateral for FHLB advance borrowings. At December 31, 2017 , there were no holdings of securities of any one issuer, other than the U.S. Government and its agencies, in an amount greater than 10% of shareholders’ equity. During 2017, Park sold certain AFS investment securities with a book value of $444,000 at a gain of $1.8 million . During 2015, Park sold certain HTM investment securities with a book value of $3.1 million at a gain of $88,000 . These securities had been paid down to 97.8% of the principal outstanding at acquisition. No securities were sold during 2016.

Loans

Loans	12 Months Ended
	Dec. 31, 2017
Loans and Leases Receivable Disclosure [Abstract]
Loans	Loans The composition of the loan portfolio, by class of loan, as of December 31, 2017 and December 31, 2016 was as follows: 12/31/2017 12/31/2016 (In thousands) Loan Balance Accrued Interest Receivable Recorded Investment Loan Balance Accrued Interest Receivable Recorded Investment Commercial, financial and agricultural * $ 1,053,453 $ 4,413 $ 1,057,866 $ 994,619 $ 3,558 $ 998,177 Commercial real estate * 1,167,607 4,283 1,171,890 1,155,703 4,161 1,159,864 Construction real estate: Commercial 125,389 401 125,790 135,343 398 135,741 Mortgage 52,203 133 52,336 48,699 106 48,805 Installment 3,878 13 3,891 4,903 17 4,920 Residential real estate: Commercial 393,094 1,029 394,123 406,687 940 407,627 Mortgage 1,110,426 1,516 1,111,942 1,169,495 1,459 1,170,954 HELOC 203,178 974 204,152 212,441 853 213,294 Installment 18,526 53 18,579 19,874 67 19,941 Consumer 1,241,736 3,808 1,245,544 1,120,850 3,385 1,124,235 Leases 2,993 36 3,029 3,243 29 3,272 Total loans $ 5,372,483 $ 16,659 $ 5,389,142 $ 5,271,857 $ 14,973 $ 5,286,830 * Included within commercial, financial and agricultural loans and commercial real estate loans is an immaterial amount of consumer loans that were not broken out by class. Loans are shown net of deferred origination fees, costs and unearned income of $12.2 million at December 31, 2017 and of $11.1 million at December 31, 2016 , which represented a net deferred income position in both years. Overdrawn deposit accounts of $1.9 million and $2.9 million had been reclassified to loans at December 31, 2017 and 2016 , respectively, and are included in the commercial, financial and agricultural loan class above. Credit Quality The following table presents the recorded investment in nonaccrual loans, accruing troubled debt restructurings ("TDRs"), and loans past due 90 days or more and still accruing by class of loan as of December 31, 2017 and December 31, 2016 : 12/31/2017 (In thousands) Nonaccrual Loans Accruing TDRs Loans Past Due 90 Days or More and Accruing Total Nonperforming Loans Commercial, financial and agricultural $ 16,773 $ 1,291 $ — $ 18,064 Commercial real estate 12,979 5,163 — 18,142 Construction real estate: Commercial 986 338 — 1,324 Mortgage 8 92 — 100 Installment 52 — — 52 Residential real estate: Commercial 18,835 224 — 19,059 Mortgage 16,841 10,766 568 28,175 HELOC 1,593 1,025 14 2,632 Installment 586 616 7 1,209 Consumer 3,403 662 1,256 5,321 Total loans $ 72,056 $ 20,177 $ 1,845 $ 94,078 12/31/2016 (In thousands) Nonaccrual Loans Accruing TDRs Loans Past Due 90 Days or More and Accruing Total Nonperforming Loans Commercial, financial and agricultural $ 20,057 $ 600 $ 15 $ 20,672 Commercial real estate 19,169 5,305 — 24,474 Construction real estate: Commercial 1,833 393 — 2,226 Mortgage — 104 — 104 Installment 61 95 12 168 Residential real estate: Commercial 23,013 89 — 23,102 Mortgage 18,313 9,612 887 28,812 HELOC 1,783 673 25 2,481 Installment 644 609 60 1,313 Consumer 2,949 748 1,139 4,836 Total loans $ 87,822 $ 18,228 $ 2,138 $ 108,188 The following table provides additional information regarding those nonaccrual and accruing TDR loans that are individually evaluated for impairment and those collectively evaluated for impairment as of December 31, 2017 and December 31, 2016 . 12/31/2017 12/31/2016 (In thousands) Nonaccrual and accruing TDRs Loans individually evaluated for impairment Loans collectively evaluated for impairment Nonaccrual and accruing TDRs Loans individually evaluated for impairment Loans collectively evaluated for impairment Commercial, financial and agricultural $ 18,064 $ 18,039 $ 25 $ 20,657 $ 20,624 $ 33 Commercial real estate 18,142 18,142 — 24,474 24,474 — Construction real estate: Commercial 1,324 1,324 — 2,226 2,226 — Mortgage 100 — 100 104 — 104 Installment 52 — 52 156 — 156 Residential real estate: Commercial 19,059 19,059 — 23,102 23,102 — Mortgage 27,607 — 27,607 27,925 — 27,925 HELOC 2,618 — 2,618 2,456 — 2,456 Installment 1,202 — 1,202 1,253 — 1,253 Consumer 4,065 — 4,065 3,697 — 3,697 Total loans $ 92,233 $ 56,564 $ 35,669 $ 106,050 $ 70,426 $ 35,624 All of the loans individually evaluated for impairment were evaluated using the fair value of the collateral or the present value of expected future cash flows as the measurement method. The following table presents loans individually evaluated for impairment by class of loan as of December 31, 2017 and December 31, 2016 . 12/31/2017 12/31/2016 (In thousands) Unpaid principal balance Recorded investment Allowance for loan losses allocated Unpaid principal balance Recorded investment Allowance for loan losses allocated With no related allowance recorded Commercial, financial and agricultural $ 19,899 $ 14,704 $ — $ 41,075 $ 19,965 $ — Commercial real estate 18,974 18,060 — 23,961 23,474 — Construction real estate: Commercial 2,788 1,324 — 3,662 2,226 — Residential real estate: Commercial 19,346 19,012 — 24,409 22,687 — With an allowance recorded Commercial, financial and agricultural 5,394 3,335 681 810 659 152 Commercial real estate 137 82 2 1,014 1,000 309 Construction real estate: Commercial — — — — — — Residential real estate: Commercial 47 47 1 427 415 87 Total $ 66,585 $ 56,564 $ 684 $ 95,358 $ 70,426 $ 548 Management’s general practice is to proactively charge down loans individually evaluated for impairment to the fair value of the underlying collateral. At December 31, 2017 and December 31, 2016 , there were $7.9 million and $24.7 million , respectively, of partial charge-offs on loans individually evaluated for impairment with no related allowance recorded and $2.1 million and $0.2 million , respectively, of partial charge-offs on loans individually evaluated for impairment that also had a specific reserve allocated. The allowance for loan losses included specific reserves related to loans individually evaluated for impairment at December 31, 2017 and 2016 , of $0.7 million and $0.5 million , respectively. These loans with specific reserves had a recorded investment of $3.5 million and $2.1 million as of December 31, 2017 and 2016 , respectively. Interest income on nonaccrual loans individually evaluated for impairment is recognized on a cash basis only when Park expects to receive the entire recorded investment of the loan. Interest income on accruing TDRs individually evaluated for impairment continues to be recorded on an accrual basis. The following tables present the average recorded investment and interest income recognized during the year subsequent to impairment on loans individually evaluated for impairment as of and for the years ended December 31, 2017 , 2016 , and 2015 : Year ended December 31, 2017 (In thousands) Recorded Investment as of December 31, 2017 Average recorded investment Interest income recognized Commercial, financial and agricultural $ 18,039 $ 23,154 $ 963 Commercial real estate 18,142 21,692 903 Construction real estate: Commercial 1,324 1,729 64 Residential real estate: Commercial 19,059 20,490 778 Consumer — 5 — Total $ 56,564 $ 67,070 $ 2,708 Year ended December 31, 2016 (In thousands) Recorded Investment as of December 31, 2016 Average recorded investment Interest income recognized Commercial, financial and agricultural $ 20,624 $ 26,821 $ 885 Commercial real estate 24,474 22,828 884 Construction real estate: Commercial 2,226 5,503 66 Residential real estate: Commercial 23,102 24,341 2,942 Consumer — 3 — Total $ 70,426 $ 79,496 $ 4,777 Year ended December 31, 2015 (In thousands) Recorded Investment as of December 31, 2015 Average recorded investment Interest income recognized Commercial, financial and agricultural $ 30,595 $ 20,179 $ 340 Commercial real estate 18,025 17,883 550 Construction real estate: Commercial 6,720 7,732 47 Residential real estate: Commercial 25,324 24,968 1,026 Consumer — — — Total $ 80,664 $ 70,762 $ 1,963 The following tables present the aging of the recorded investment in past due loans as of December 31, 2017 and December 31, 2016 by class of loan. 12/31/2017 (In thousands) Accruing loans past due 30-89 days Past due, nonaccrual loans and loans past due 90 days or more and accruing (1) Total past due Total current (2) Total recorded investment Commercial, financial and agricultural $ 145 $ 1,043 $ 1,188 $ 1,056,678 $ 1,057,866 Commercial real estate 856 2,360 3,216 1,168,674 1,171,890 Construction real estate: Commercial 29 — 29 125,761 125,790 Mortgage 256 — 256 52,080 52,336 Installment 54 19 73 3,818 3,891 Residential real estate: Commercial 16 1,586 1,602 392,521 394,123 Mortgage 11,515 9,232 20,747 1,091,195 1,111,942 HELOC 616 876 1,492 202,660 204,152 Installment 239 253 492 18,087 18,579 Consumer 11,515 2,407 13,922 1,231,622 1,245,544 Leases — — — 3,029 3,029 Total loans $ 25,241 $ 17,776 $ 43,017 $ 5,346,125 $ 5,389,142 (1) Includes an aggregate of $1.8 million of loans past due 90 days or more and accruing. The remaining are past due, nonaccrual loans. (2) Includes an aggregate of $56.1 million of nonaccrual loans which are current in regards to contractual principal and interest payments. 12/31/2016 (In thousands) Accruing loans past due 30-89 days Past due, nonaccrual loans and loans past due 90 days or more and accruing (1) Total past due Total current (2) Total recorded investment Commercial, financial and agricultural $ 371 $ 4,113 $ 4,484 $ 993,693 $ 998,177 Commercial real estate 355 2,499 2,854 1,157,010 1,159,864 Construction real estate: Commercial — 541 541 135,200 135,741 Mortgage 559 — 559 48,246 48,805 Installment 223 64 287 4,633 4,920 Residential real estate: Commercial 330 3,631 3,961 403,666 407,627 Mortgage 10,854 9,769 20,623 1,150,331 1,170,954 HELOC 970 1,020 1,990 211,304 213,294 Installment 350 319 669 19,272 19,941 Consumer 12,579 2,094 14,673 1,109,562 1,124,235 Leases — — — 3,272 3,272 Total loans $ 26,591 $ 24,050 $ 50,641 $ 5,236,189 $ 5,286,830 (1) Includes an aggregate of $2.1 million of loans past due 90 days or more and accruing. The remaining are past due, nonaccrual loans. (2) Includes an aggregate of $65.9 million of nonaccrual loans which are current in regards to contractual principal and interest payments. Credit Quality Indicators Management utilizes past due information as a credit quality indicator across the loan portfolio. Past due information as of December 31, 2017 and 2016 is included in the tables above. The past due information is the primary credit quality indicator within the following classes of loans: (1) mortgage loans and installment loans in the construction real estate segment; (2) mortgage loans, HELOC and installment loans in the residential real estate segment; and (3) consumer loans. The primary credit indicator for commercial loans is based on an internal grading system that grades all commercial loans on a scale from 1 to 8. Credit grades are continuously monitored by the responsible loan officer and adjustments are made when appropriate. A grade of 1 indicates little or no credit risk and a grade of 8 is considered a loss. Commercial loans that are pass-rated (graded a 1 through a 4) are considered to be of acceptable credit risk. Commercial loans graded a 5 (special mention) are considered to be watch list credits and a higher loan loss reserve percentage is allocated to these loans. Loans classified as special mention have potential weaknesses that require management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the loan or of Park’s credit position at some future date. Commercial loans graded a 6 (substandard), also considered watch list credits, are considered to represent higher credit risk and, as a result, a higher loan loss reserve percentage is allocated to these loans. Loans classified as substandard are inadequately protected by the current sound worth and paying capacity of the obligor or the value of the collateral pledged, if any. Loans so classified have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that Park will sustain some loss if the deficiencies are not corrected. Commercial loans graded a 7 (doubtful) are shown as nonaccrual and Park generally charges these loans down to their fair value by taking a partial charge-off or recording a specific reserve. Loans classified as doubtful have all the weaknesses inherent in those classified as substandard with the added characteristic that the weaknesses make collection or liquidation in full, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. Certain 6-rated loans and all 7-rated loans are placed on nonaccrual status and included within the impaired category. A loan is deemed impaired when management determines the borrower's ability to perform in accordance with the contractual loan agreement is in doubt. Any commercial loan graded an 8 (loss) is completely charged off. The tables below present the recorded investment by loan grade at December 31, 2017 and December 31, 2016 for all commercial loans: 12/31/2017 (In thousands) 5 Rated 6 Rated Nonaccrual and Accruing Troubled Debt Restructurings Pass Rated Recorded Investment Commercial, financial and agricultural* $ 17,272 $ 153 $ 18,064 $ 1,022,377 $ 1,057,866 Commercial real estate* 5,322 457 18,142 1,147,969 1,171,890 Construction real estate: Commercial 278 — 1,324 124,188 125,790 Residential real estate: Commercial 216 1 19,059 374,847 394,123 Leases — — — 3,029 3,029 Total Commercial Loans $ 23,088 $ 611 $ 56,589 $ 2,672,410 $ 2,752,698 * Included within commercial, financial and agricultural loans and commercial real estate loans is an immaterial amount of consumer loans that were not broken out by class. 12/31/2016 (In thousands) 5 Rated 6 Rated Nonaccrual and Accruing Troubled Debt Restructurings Pass Rated Recorded Investment Commercial, financial and agricultural* $ 5,826 $ — $ 20,657 $ 971,694 $ 998,177 Commercial real estate* 7,548 190 24,474 1,127,652 1,159,864 Construction real estate: Commercial 287 118 2,226 133,110 135,741 Residential real estate: Commercial 1,055 124 23,102 383,346 407,627 Leases — — — 3,272 3,272 Total Commercial Loans $ 14,716 $ 432 $ 70,459 $ 2,619,074 $ 2,704,681 * Included within commercial, financial and agricultural loans and commercial real estate loans is an immaterial amount of consumer loans that were not broken out by class. Troubled Debt Restructuring Management classifies loans as TDRs when a borrower is experiencing financial difficulties and Park has granted a concession to the borrower as part of a modification or in the loan renewal process. In order to determine whether a borrower is experiencing financial difficulty, an evaluation is performed of the probability that the borrower will be in payment default on any of the borrower's debt in the foreseeable future without the modification. This evaluation is performed in accordance with the Company’s internal underwriting policy. Management’s policy is to modify loans by extending the term or by granting a temporary or permanent contractual interest rate below the market rate, not by forgiving debt. A court's discharge of a borrower's debt in a Chapter 7 bankruptcy is considered a concession when the borrower does not reaffirm the discharged debt. Certain loans which were modified during the years ended December 31, 2017 and December 31, 2016 did not meet the definition of a TDR as the modification was a delay in a payment that was considered to be insignificant. Management considers a forbearance period of up to three months or a delay in payment of up to 30 days to be insignificant. TDRs may be classified as accruing if the borrower has been current for a period of at least six months with respect to loan payments and management expects that the borrower will be able to continue to make payments in accordance with the terms of the restructured note. Management reviews all accruing TDRs quarterly to ensure payments continue to be made in accordance with the modified terms. Management reviews renewals/modifications of loans previously identified as TDRs to consider if it is appropriate to remove the TDR classification. If the borrower is no longer experiencing financial difficulty and the renewal/modification does not contain a concessionary interest rate or other concessionary terms and the terms of the renewal/modification are considered to be market terms based on the current risk characteristics of the borrower, management considers the potential removal of the TDR classification. If deemed appropriate, the TDR classification is removed as the borrower has complied with the terms of the loan at the date of the renewal/modification and there was a reasonable expectation that the borrower would continue to comply with the terms of the loan subsequent to the date of the renewal/modification. The majority of these TDRs were originally considered restructurings in a prior year as a result of a renewal/modification with an interest rate that was not commensurate with the risk of the underlying loan at the time of the renewal/modification. During the years ended December 31, 2017 and 2016 , Park removed the TDR classification on $0.5 million and $2.7 million , respectively, of loans that met the requirements discussed above. At December 31, 2017 and 2016 , there were $38.5 million and $46.9 million , respectively, of TDRs included in the nonaccrual loan totals. At December 31, 2017 and 2016 , $32.4 million and $38.0 million , respectively, of these nonaccrual TDRs were performing in accordance with the terms of the restructured note. As of December 31, 2017 and 2016 , loans with a recorded investment of $20.2 million and $18.2 million , respectively, were included in accruing TDR loan totals. Management will continue to review the restructured loans and may determine it appropriate to move certain nonaccrual TDRs to accrual status in the future. At December 31, 2017 and 2016 , Park had commitments to lend $1.3 million and $0.7 million , respectively, of additional funds to borrowers whose outstanding loan terms had been modified in a TDR. The specific reserve related to TDRs at December 31, 2017 and 2016 was $0.5 million and $0.2 million , respectively. Modifications made in 2016 and 2017 were largely the result of renewals and extending the maturity date of the loan, at terms consistent with the original note. These modifications were deemed to be TDRs primarily due to Park’s conclusion that the borrower would likely not have qualified for similar terms through another lender. Many of the modifications deemed to be TDRs were previously identified as impaired loans, and thus were also previously evaluated for impairment under ASC 310. Additional specific reserves of $0.3 million were recorded during the year ended December 31, 2017 , as a result of TDRs identified in the 2017 year. Additional specific reserves of $1.0 million were recorded during the year ended December 31, 2016 as a result of TDRs identified in the 2016 year. Additional specific reserves of $1.3 million were recorded during the year ended December 31, 2015 as a result of TDRs identified in the 2015 year. The terms of certain other loans were modified during the years ended December 31, 2017 and 2016 that did not meet the definition of a TDR. Substandard commercial loans modified during the years ended December 31, 2017 and 2016 which did not meet the definition of a TDR had a total recorded investment of $106,000 and $26,000 , respectively. The renewal/modification of these loans: (1) resulted in a delay in a payment that was considered to be insignificant, or (2) resulted in Park obtaining additional collateral or guarantees that improved the likelihood of the ultimate collection of the loan such that the modification was deemed to be at market terms. Consumer loans modified during 2017 which did not meet the definition of a TDR had a total recorded investment as of December 31, 2017 of $8.9 million . Consumer loans modified during 2016 which did not meet the definition of a TDR had a total recorded investment as of December 31, 2016 of $7.4 million . Many of these loans were to borrowers who were not experiencing financial difficulties but who were looking to reduce their cost of funds. The following tables detail the number of contracts modified as TDRs during the years ended December 31, 2017 , 2016 and 2015 as well as the recorded investment of these contracts at December 31, 2017 , 2016 , and 2015. The recorded investment pre- and post-modification is generally the same due to the fact that Park does not typically forgive principal. Year ended December 31, 2017 (In thousands) Number of Contracts Accruing Nonaccrual Recorded Investment Commercial, financial and agricultural 29 $ 945 $ 2,770 $ 3,715 Commercial real estate 9 1,050 313 1,363 Construction real estate: Commercial — — — — Mortgage 1 — 8 8 Installment — — — — Residential real estate: Commercial 15 144 486 630 Mortgage 33 888 1,359 2,247 HELOC 19 474 102 576 Installment 11 251 43 294 Consumer 309 171 1,121 1,292 Total loans 426 $ 3,923 $ 6,202 $ 10,125 Year ended December 31, 2016 (In thousands) Number of Contracts Accruing Nonaccrual Recorded Investment Commercial, financial and agricultural 32 $ 191 $ 8,450 $ 8,641 Commercial real estate 14 3,844 2,537 6,381 Construction real estate: Commercial 2 — 1,143 1,143 Mortgage — — — — Installment 1 — — — Residential real estate: Commercial 11 89 1,033 1,122 Mortgage 34 114 2,292 2,406 HELOC 13 104 178 282 Installment 5 102 3 105 Consumer 293 184 994 1,178 Total loans 405 $ 4,628 $ 16,630 $ 21,258 Year ended December 31, 2015 (In thousands) Number of Contracts Accruing Nonaccrual Recorded Investment Commercial, financial and agricultural 39 $ 8,948 $ 3,640 $ 12,588 Commercial real estate 14 637 3,523 4,160 Construction real estate: Commercial 2 513 — 513 Mortgage 1 19 — 19 Installment — — — — Residential real estate: Commercial 11 — 1,185 1,185 Mortgage 39 1,132 2,122 3,254 HELOC 26 315 45 360 Installment 9 — 155 155 Consumer 283 202 888 1,090 Total loans 424 $ 11,766 $ 11,558 $ 23,324 Of those loans which were modified and determined to be a TDR during the year ended December 31, 2017 , $1.8 million were on nonaccrual status as of December 31, 2016 . Of those loans which were modified and determined to be a TDR during the year ended December 31, 2016 , $9.4 million were on nonaccrual status as of December 31, 2015 . Of those loans which were modified and determined to be a TDR during the year ended December 31, 2015, $0.8 million were on nonaccrual status as of December 31, 2014. The following table presents the recorded investment in financing receivables which were modified as TDRs within the previous 12 months and for which there was a payment default during the year ended December 31, 2017 , December 31, 2016 , and December 31, 2015. For this table, a loan is considered to be in default when it becomes 30 days contractually past due under the modified terms. The additional allowance for loan loss resulting from the defaults on TDR loans was immaterial. Year ended December 31, 2017 Year ended Year ended (In thousands) Number of Contracts Recorded Investment Number of Contracts Recorded Investment Number of Contracts Recorded Investment Commercial, financial and agricultural — $ — 7 $ 419 1 $ 1 Commercial real estate 2 82 5 843 1 626 Construction real estate: Commercial — — — — — — Mortgage — — — — — — Installment — — — — — — Residential real estate: Commercial 2 117 7 848 3 1,005 Mortgage 6 467 15 1,201 12 682 HELOC 4 194 — — 1 5 Installment — — 1 3 2 101 Consumer 50 375 62 484 47 434 Leases — — — — — — Total loans 64 $ 1,235 $ 97 $ 3,798 67 $ 2,854 Of the $1.2 million in modified TDRs which defaulted during the year ended December 31, 2017 , $180,000 were accruing loans and $1.1 million were nonaccrual loans. Of the $3.8 million in modified TDRs which defaulted during the year ended December 31, 2016 , $111,000 were accruing loans and $3.7 million were nonaccrual loans. Of the $2.9 million in modified TDRs which defaulted during the year ended December 31, 2015, $44,000 were accruing loans and $2.8 million were nonaccrual loans. Certain of the Corporation’s executive officers, directors and related entities of directors are loan customers of PNB. As of December 31, 2017 and 2016 , credit exposure aggregating approximately $42.1 million and $43.4 million , respectively, was outstanding to such parties. Of this total exposure, approximately $31.1 million and $29.6 million was outstanding at December 31, 2017 and 2016 , respectively, with the remaining balance representing available credit. During 2017 , new loans and advances on existing loans were made to these executive officers, directors and related entities of directors totaling $1.6 million and $11.4 million , respectively. These extensions of credit were offset by principal payments of $11.4 million . During 2016 , new loans and advances on existing loans were $5.4 million and $3.5 million , respectively. These extensions of credit were offset by principal payments of $15.3 million .

Allowance for Loan Losses

Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2017
Allowance For Loan Losses [Abstract]
Allowance for Loan Losses	Allowance for Loan Losses The allowance for loan losses is that amount management believes is adequate to absorb probable incurred credit losses in the loan portfolio based on management’s evaluation of various factors including the overall growth in the loan portfolio, an analysis of individual loans, prior and current loss experience, and current economic conditions. A provision for loan losses is charged to operations based on management’s periodic evaluation of these and other pertinent factors as discussed within Note 1 - Summary of Significant Accounting Policies. Loss factors are reviewed quarterly and updated at least annually to reflect recent loan loss history and incorporate current risk and trends which may not be recognized in historical data. The following are factors management reviews on a quarterly or annual basis. • Historical Loss Factor: Management updated the historical loss calculation during the fourth quarter of 2017, incorporating annualized net charge-offs plus changes in specific reserves through December 31, 2017. With the addition of 2017 historical losses, management extended the historical loss period to 96 months from 84 months. The 96 month historical loss period captures all annual periods subsequent to June 2009, the end of the most recent recession, thus encompassing the full economic cycle to date. • Loss Emergence Period Factor: At least annually, management calculates the loss emergence period for each commercial loan segment. This loss emergence period is calculated based upon the average period of time it takes from the probable occurrence of a loss event to the credit being moved to nonaccrual. If the loss emergence period for any commercial loan segment is greater than one year, management applies additional general reserves to all performing loans within that segment of the commercial loan portfolio. The loss emergence period was last updated in the fourth quarter of 2017. • Loss Migration Factor: Park’s commercial loans are individually risk graded. If loan downgrades occur, the probability of default increases, and accordingly, management allocates a higher percentage reserve to those accruing commercial loans graded special mention and substandard. Annually, management calculates a loss migration factor for each commercial loan segment for special mention and substandard credits based on a review of losses over the period of time a loan takes to migrate from pass-rated to impaired. The loss migration factor was last updated in the fourth quarter of 2017. • Environmental Loss Factor: Management has identified certain macroeconomic factors that trend in accordance with losses in Park’s commercial loan portfolio. These macroeconomic factors are reviewed quarterly and the adjustments made to the environmental loss factor impacting each segment in the performing commercial loan portfolio correlate to changes in the macroeconomic environment. The environmental loss factor was reduced by 0.025% during the first quarter of 2017 due to improved consumer confidence, as measured by the Conference Board Consumer Confidence Index. The activity in the allowance for loan losses for the years ended December 31, 2017 , 2016 , and 2015 is summarized in the following tables. Year ended December 31, 2017 (In thousands) Commercial, financial and agricultural Commercial real estate Construction real estate Residential real estate Consumer Leases Total Allowance for credit losses: Beginning balance $ 13,434 $ 10,432 $ 5,247 $ 10,958 $ 10,553 $ — $ 50,624 Charge-offs 6,017 1,798 105 1,208 10,275 — 19,403 Recoveries (809 ) (810 ) (2,124 ) (1,863 ) (4,603 ) (1 ) (10,210 ) Net charge-offs (recoveries) 5,208 988 (2,019 ) (655 ) 5,672 (1 ) 9,193 Provision (Recovery) 6,796 157 (2,836 ) (2,292 ) 6,733 (1 ) 8,557 Ending balance $ 15,022 $ 9,601 $ 4,430 $ 9,321 $ 11,614 — $ 49,988 Year ended December 31, 2016 (In thousands) Commercial, financial and agricultural Commercial real estate Construction real estate Residential real estate Consumer Leases Total Allowance for credit losses: Beginning balance $ 13,694 $ 9,197 $ 8,564 $ 13,514 $ 11,524 $ 1 $ 56,494 Charge-offs 5,786 412 1,436 3,014 10,151 — 20,799 Recoveries (1,259 ) (3,671 ) (8,559 ) (2,446 ) (4,094 ) (1 ) (20,030 ) Net charge-offs (recoveries) 4,527 (3,259 ) (7,123 ) 568 6,057 (1 ) 769 Provision (Recovery) 4,267 (2,024 ) (10,440 ) (1,988 ) 5,086 (2 ) (5,101 ) Ending balance $ 13,434 $ 10,432 $ 5,247 $ 10,958 $ 10,553 $ — $ 50,624 Year ended December 31, 2015 (In thousands) Commercial, financial and agricultural Commercial real estate Construction real estate Residential real estate Consumer Leases Total Allowance for credit losses: Beginning balance $ 10,719 $ 8,808 $ 8,652 $ 14,772 $ 11,401 $ — $ 54,352 Charge-offs 2,478 348 470 2,352 8,642 — 14,290 Recoveries (1,373 ) (2,241 ) (2,092 ) (2,438 ) (3,295 ) (3 ) (11,442 ) Net charge-offs (recoveries) 1,105 (1,893 ) (1,622 ) (86 ) 5,347 (3 ) 2,848 Provision (Recovery) 4,080 (1,504 ) (1,710 ) (1,344 ) 5,470 (2 ) 4,990 Ending balance $ 13,694 $ 9,197 $ 8,564 $ 13,514 $ 11,524 $ 1 $ 56,494 Loans collectively evaluated for impairment in the following tables include all performing loans at December 31, 2017 and 2016 , as well as nonperforming loans internally classified as consumer loans. Nonperforming consumer loans are not typically individually evaluated for impairment, but receive a portion of the statistical allocation of the allowance for loan losses. Loans individually evaluated for impairment include all impaired loans internally classified as commercial loans at December 31, 2017 and 2016 , which are evaluated for impairment in accordance with GAAP (see Note 1 - Summary of Significant Accounting Policies). The composition of the allowance for loan losses at December 31, 2017 and 2016 was as follows: December 31, 2017 (In thousands) Commercial, financial, and agricultural Commercial real estate Construction real estate Residential real estate Consumer Leases Total Allowance for loan losses: Ending allowance balance attributed to loans Individually evaluated for impairment $ 681 $ 2 $ — $ 1 $ — $ — $ 684 Collectively evaluated for impairment 14,341 9,599 4,430 9,320 11,614 — 49,304 Total ending allowance balance $ 15,022 $ 9,601 $ 4,430 $ 9,321 $ 11,614 $ — $ 49,988 Loan Balance: Loans individually evaluated for impairment $ 18,034 $ 18,131 $ 1,322 $ 19,058 $ — $ — $ 56,545 Loans collectively evaluated for impairment 1,035,419 1,149,476 180,148 1,706,166 1,241,736 2,993 5,315,938 Total ending loan balance $ 1,053,453 $ 1,167,607 $ 181,470 $ 1,725,224 $ 1,241,736 $ 2,993 $ 5,372,483 Allowance for loan losses as a percentage of loan balance: Loans individually evaluated for impairment 3.78 % 0.01 % — % 0.01 % — % — % 1.21 % Loans collectively evaluated for impairment 1.39 % 0.84 % 2.46 % 0.55 % 0.94 % — % 0.93 % Total 1.43 % 0.82 % 2.44 % 0.54 % 0.94 % — % 0.93 % Recorded Investment: Loans individually evaluated for impairment $ 18,039 $ 18,142 $ 1,324 $ 19,059 $ — $ — $ 56,564 Loans collectively evaluated for impairment 1,039,827 1,153,748 180,693 1,709,737 1,245,544 3,029 5,332,578 Total ending recorded investment $ 1,057,866 $ 1,171,890 $ 182,017 $ 1,728,796 $ 1,245,544 $ 3,029 $ 5,389,142 December 31, 2016 (In thousands) Commercial, financial, and agricultural Commercial real estate Construction real estate Residential real estate Consumer Leases Total Allowance for loan losses: Ending allowance balance attributed to loans Individually evaluated for impairment $ 152 $ 309 $ — $ 87 $ — $ — $ 548 Collectively evaluated for impairment 13,282 10,123 5,247 10,871 10,553 — 50,076 Total ending allowance balance $ 13,434 $ 10,432 $ 5,247 $ 10,958 $ 10,553 $ — $ 50,624 Loan Balance: Loans individually evaluated for impairment $ 20,622 $ 24,465 $ 2,226 $ 23,102 $ — $ — $ 70,415 Loans collectively evaluated for impairment 973,997 1,131,238 186,719 1,785,395 1,120,850 3,243 5,201,442 Total ending loan balance $ 994,619 $ 1,155,703 $ 188,945 $ 1,808,497 $ 1,120,850 $ 3,243 $ 5,271,857 Allowance for loan losses as a percentage of loan balance: Loans individually evaluated for impairment 0.74 % 1.26 % — % 0.38 % — % — % 0.78 % Loans collectively evaluated for impairment 1.36 % 0.89 % 2.81 % 0.61 % 0.94 % — % 0.96 % Total 1.35 % 0.90 % 2.78 % 0.61 % 0.94 % — % 0.96 % Recorded Investment: Loans individually evaluated for impairment $ 20,624 $ 24,474 $ 2,226 $ 23,102 $ — $ — $ 70,426 Loans collectively evaluated for impairment 977,553 1,135,390 187,240 1,788,714 1,124,235 3,272 5,216,404 Total ending recorded investment $ 998,177 $ 1,159,864 $ 189,466 $ 1,811,816 $ 1,124,235 $ 3,272 $ 5,286,830

Loans Held for Sale Loans Held

Loans Held for Sale Loans Held for Sale	12 Months Ended
	Dec. 31, 2017
Loans Held for Sale [Abstract]
Loans Held for Sale [Table Text Block]	Loans Held for Sale Mortgage loans held for sale are carried at their fair value. Mortgage loans held for sale were $4.1 million and $10.4 million at December 31, 2017 and 2016 , respectively. These amounts are included in loans on the Consolidated Balance Sheets and in the residential real estate loan segments in Note 5 - Loans and Note 6 - Allowance for Loan Losses. The contractual balance was $4.1 million and $10.3 million at December 31, 2017 and 2016 , respectively. The gain expected upon sale was $55,000 and $131,000 at December 31, 2017 and 2016 , respectively. None of these loans were 90 days or more past due or on nonaccrual status as of December 31, 2017 or 2016 . During 2015, Park transferred certain commercial loans held for investment, with a book balance of $144,000 , to the loans held for sale portfolio, and subsequently completed the sale of these commercial loans held for sale, recognizing a net gain on sale of $756,000 . No commercial loans were held for sale or sold during 2017 or 2016.

Other Real Estate Owned Other R

Other Real Estate Owned Other Real Estate Owned	12 Months Ended
	Dec. 31, 2017
Schedule of Assets Repossessed or Foreclosed, or loans in process of foreclosure [Line Items]
Real Estate Owned [Text Block]	Other Real Estate Owned The carrying amount of foreclosed properties held at December 31, 2017 and December 31, 2016 are listed below, as well as the recorded investment of loans secured by residential real estate properties for which formal foreclosure proceedings were in process at those dates. (In thousands) December 31, 2017 December 31, 2016 OREO: Commercial real estate $ 7,888 $ 7,642 Construction real estate 4,852 4,624 Residential real estate 1,450 1,660 Total OREO $ 14,190 $ 13,926 Loans in process of foreclosure: Residential real estate $ 2,948 $ 3,250

Premises And Equipment

Premises And Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment The major categories of premises and equipment and accumulated depreciation are summarized as follows: December 31 (In thousands) 2017 2016 Land $ 19,603 $ 19,577 Buildings 77,711 75,472 Equipment, furniture and fixtures 55,799 52,719 Leasehold improvements 3,273 3,400 Total $ 156,386 $ 151,168 Less accumulated depreciation (100,485 ) (93,197 ) Premises and equipment, net $ 55,901 $ 57,971 Depreciation expense amounted to $8.6 million , $8.4 million and $7.3 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. The Corporation leases certain premises and equipment accounted for as operating leases. The following is a schedule of the future minimum rental payments required for the next five years under such leases with initial terms in excess of one year: (In thousands) 2018 $ 1,726 2019 1,563 2020 865 2021 502 2022 446 Thereafter 307 Total $ 5,409 Rent expense for Park was $2.0 million , $2.1 million and $1.7 million , for the years ended December 31, 2017 , 2016 and 2015 , respectively.

Investment in Qualified Afforda

Investment in Qualified Affordable Housing	12 Months Ended
	Dec. 31, 2017
Investments in Qualified Affordable Housing [Abstract]
Equity Method Investments and Joint Ventures Disclosure [Text Block]	Investment in Qualified Affordable Housing Park makes certain equity investments in various limited partnerships that sponsor affordable housing projects. The purposes of these investments are to achieve a satisfactory return on capital, help create affordable housing opportunities, and assist the Company to achieve our goals associated with the Community Reinvestment Act. As permitted by ASU 2014-01, Accounting for Investments in Qualified Affordable Housing Projects , Park has elected the proportional amortization method of accounting. Under the proportional amortization method, amortization expense and tax benefits are recognized through the provision for income taxes. The table below details the balances of Park’s affordable housing tax credit investments and related unfunded commitments as of December 31, 2017 and 2016 . (In thousands) December 31, 2017 December 31, 2016 Affordable housing tax credit investments $ 49,669 $ 52,947 Unfunded commitments 14,282 14,282 Commitments are funded when capital calls are made by the general partner. Park expects that the commitments as of December 31, 2017 will be funded between 2018 and 2027. During the years ended December 31, 2017 , 2016 and 2015 , Park recognized amortization expense of $ 10.3 million , $7.3 million and $6.7 million , respectively, which was included within the provision for income taxes. Included in the $10.3 million of amortization expense during the year ended December 31, 2017 was $3.1 million in accelerated amortization as a result of tax reform as discussed in Note 19 - Income Taxes. This reflects an overall reduction in the total projected tax benefits of the affordable housing tax credit investments as a result of the reduction in the corporate federal income tax rate to 21% . For the years ended December 31, 2017 , 2016 and 2015 , Park recognized tax credits and other benefits from its affordable housing tax credit investments of $9.4 million , $9.4 million and $8.9 million , respectively.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Deposits	Deposits At December 31, 2017 and 2016 , non-interest bearing and interest bearing deposits were as follows: December 31 (In thousands) 2017 2016 Non-interest bearing $ 1,633,941 $ 1,523,417 Interest bearing 4,183,385 3,998,539 Total $ 5,817,326 $ 5,521,956 At December 31, 2017 , the maturities of time deposits were as follows: (In thousands) 2018 $ 590,331 2019 217,286 2020 119,452 2021 51,958 2022 53,917 After 5 years 532 Total $ 1,033,476 At December 31, 2017 and 2016, respectively, Park had approximately $24.9 million and $26.5 million of deposits received from executive officers, directors and related entities of directors. Time deposits that exceed the FDIC Insurance limit of $250,000 at December 31, 2017 and 2016 were $36.3 million and $43.3 million , respectively.

Repurchase Agreement Borrowings

Repurchase Agreement Borrowings Repurchase Agreement Borrowings	12 Months Ended
	Dec. 31, 2017
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Table Text Block]	Repurchase Agreement Borrowings Securities sold under agreements to repurchase ("repurchase agreements") with customers represent funds deposited by customers, generally on an overnight basis, that are collateralized by investment securities owned by Park. Repurchase agreements with customers are included in short-term borrowings on the Consolidated Balance Sheets. Park's repurchase agreements with a third-party financial institution are classified as long-term debt on the Consolidated Balance Sheets. All repurchase agreements are subject to the terms and conditions of repurchase/security agreements between Park and the client and are accounted for as secured borrowings. Park's repurchase agreements reflected in short-term borrowings consist of customer accounts and securities which are pledged on an individual security basis. At December 31, 2017 and December 31, 2016 , Park's repurchase agreement borrowings totaled $183 million and $510 million , respectively. At December 31, 2016 , $300 million of Park's repurchase agreement borrowings were classified as long-term debt, with the remaining amount being classified as short-term borrowings on the Consolidated Balance Sheets. At December 31, 2017 , all repurchase agreements were classified as short-term borrowings. These borrowings were collateralized with U.S. government and agency securities with a fair value of $213 million and $569 million at December 31, 2017 and December 31, 2016 , respectively. Declines in the value of the collateral would require Park to pledge additional securities. As of December 31, 2017 and December 31, 2016 , Park had $975 million and $640 million , respectively, of available unpledged securities. The following table presents the carrying value of Park's repurchase agreements by remaining contractual maturity and collateral pledged at December 31, 2017 and December 31, 2016 : December 31, 2017 (In thousands) Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 days 30 - 90 days Greater than 90 days Total U.S. government and agency securities $ 182,185 $ — $ — $ 1,104 $ 183,289 December 31, 2016 (In thousands) Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 days 30 - 90 days Greater than 90 days Total U.S. government and agency securities $ 208,691 $ — $ — $ 301,104 $ 509,795 See Note 13 - Short-Term Borrowings for additional information related to repurchase agreements classified as short-term borrowings.

Short-Term Borrowings

Short-Term Borrowings	12 Months Ended
	Dec. 31, 2017
Short-term Debt [Abstract]
Short-Term Borrowings	Short-Term Borrowings Short-term borrowings were as follows: December 31 (In thousands) 2017 2016 Securities sold under agreements to repurchase $ 183,289 $ 209,795 FHLB advances 208,000 185,000 Total short-term borrowings $ 391,289 $ 394,795 The outstanding balances for all short-term borrowings as of December 31, 2017 and 2016 and the weighted-average interest rates as of and paid during each of the years then ended were as follows: (In thousands) Repurchase agreements FHLB Advances 2017 Ending balance $ 183,289 $ 208,000 Highest month-end balance 230,905 208,000 Average daily balance 205,269 23,924 Weighted-average interest rate: As of year-end 0.41 % 1.64 % Paid during the year 0.35 % 1.16 % 2016 Ending balance $ 209,795 $ 185,000 Highest month-end balance 248,277 185,000 Average daily balance 224,763 15,694 Weighted-average interest rate: As of year-end 0.17 % 0.80 % Paid during the year 0.16 % 0.63 % During 2016 and 2017 , outstanding FHLB advances were collateralized by investment securities owned by the Corporation’s bank subsidiary (PNB) and by various loans pledged under a blanket agreement by the Corporation’s bank subsidiary. At both December 31, 2017 and 2016, $25 million of investment securities were pledged as collateral for FHLB advances. At December 31, 2017 and 2016 , $1,789 million and $1,909 million , respectively, of commercial real estate and residential mortgage loans were pledged under a blanket agreement to the FHLB by Park’s bank subsidiary. See Note 12 - Repurchase Agreement Borrowings for information related to investment securities collateralizing repurchase agreements.

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Long-term debt is listed below: December 31, 2017 2016 (In thousands) Outstanding Balance Average Rate Outstanding Balance Average Rate Total Federal Home Loan Bank advances by year of maturity: 2017 $ — — % $ 50,000 1.25 % 2018 150,000 2.04 % 150,000 2.04 % 2019 100,000 1.92 % 75,000 1.96 % 2020 50,000 2.04 % 25,000 2.14 % 2021 100,000 1.96 % — — % 2022 — — % — — % Thereafter 100,000 3.40 % 100,000 3.40 % Total $ 500,000 2.27 % 400,000 2.27 % Total broker repurchase agreements by year of maturity: 2017 — — % 300,000 1.75 % Total $ — — % $ 300,000 1.75 % Total combined long-term debt by year of maturity: 2017 — — % 350,000 1.68 % 2018 150,000 2.04 % 150,000 2.04 % 2019 100,000 1.92 % 75,000 1.96 % 2020 50,000 2.04 % 25,000 2.14 % 2021 100,000 1.96 % — — % 2022 — — % — — % Thereafter 100,000 3.40 % 100,000 3.40 % Total $ 500,000 2.27 % $ 700,000 2.05 % Prepayment penalty — — (5,719 ) — Total long-term debt $ 500,000 2.27 % $ 694,281 2.07 % On November 30, 2012, Park restructured $300 million in repurchase agreements at a rate of 1.75% . As part of this restructuring, Park paid a prepayment penalty of $25 million . The penalty was amortized as an adjustment to interest expense over the remaining term of the repurchase agreements using the effective interest method, resulting in an effective interest rate of 3.55% . Of the $25 million prepayment penalty, none remained to be amortized as of December 31, 2017 . On November 21, 2014, Park restructured $50 million in FHLB advances at a rate of 1.25% . As part of this restructuring, Park paid a prepayment penalty of $3.2 million . The penalty was amortized as an adjustment to interest expense over the remaining term of the advances using the effective interest method, resulting in an effective interest rate of 3.52% . Of the $3.2 million prepayment penalty, none remained to be amortized as of December 31, 2017 . On March 30, 2015, Park prepaid $54.5 million of FHLB advances, with a weighted average rate of 1.59% , resulting in a prepayment penalty of $532,000 recognized within other expense on the Consolidated Statements of Income for the year ended December 31, 2015. On October 20, 2016, Park prepaid $50.0 million of FHLB advances, incurring a $5.6 million prepayment penalty recognized within other expense on the Consolidated Statements of Income for the year ended December 31, 2016. These advances had an interest rate of 3.15% and a maturity date of November 13, 2023. Park had $100.0 million of long-term debt at December 31, 2017 with a contractual maturity longer than five years. However, all of this debt is callable by the lender in 2018. At December 31, 2017 and 2016 , FHLB advances were collateralized by investment securities owned by the Corporation’s bank subsidiary (PNB) and by various loans pledged under a blanket agreement by PNB's banking divisions. At both December 31, 2017 and 2016 , $25 million of investment securities were pledged as collateral for FHLB advances. At December 31, 2017 and 2016 , $1,789 million and $1,909 million , respectively, of commercial real estate and residential mortgage loans were pledged under a blanket agreement to the FHLB by PNB. See Note 12 - Repurchase Agreement Borrowings for information related to investment securities collateralizing repurchase agreements.

Subordinated Notes

Subordinated Notes	12 Months Ended
	Dec. 31, 2017
Long-term Debt, Unclassified [Abstract]
Subordinated Debentures/Notes	Subordinated Notes As part of the acquisition of Vision's parent bank holding company ("Vision Parent") on March 9, 2007, Park became the successor to Vision Parent under (i) the Amended and Restated Trust Agreement of Vision Bancshares Trust I (the “Trust”), dated as of December 5, 2005, (ii) the Junior Subordinated Indenture, dated as of December 5, 2005, and (iii) the Guarantee Agreement, also dated as of December 5, 2005. On December 1, 2005, Vision Parent formed a wholly-owned Delaware statutory business trust, Vision Bancshares Trust I (“Trust I”), which issued $15.0 million of Trust I's floating rate preferred securities (the “Trust Preferred Securities”) to institutional investors. These Trust Preferred Securities qualify as Tier I capital under FRB guidelines. All of the common securities of Trust I are owned by Park. The proceeds from the issuance of the common securities and the Trust Preferred Securities were used by Trust I to purchase $15.5 million of junior subordinated notes, which carry a floating rate based on three-month LIBOR plus 148 basis points. The junior subordinated notes represent the sole asset of Trust I. The Trust Preferred Securities accrue and pay distributions at a floating rate of three-month LIBOR plus 148 basis points per annum. The Trust Preferred Securities are mandatorily redeemable upon maturity of the junior subordinated notes in December 2035, or upon earlier redemption as provided in the junior subordinated notes. Park has the right to redeem the junior subordinated notes purchased by Trust I in whole or in part, on or after December 30, 2010. As specified in the indenture, if the junior subordinated notes are redeemed prior to maturity, the redemption price will be the principal amount, plus any unpaid accrued interest. In accordance with GAAP, Trust I is not consolidated with Park’s financial statements, but rather the subordinated notes are reflected as a liability. On April 20, 2012, Park entered into a Note Purchase Agreement, dated April 20, 2012 (the “2012 Purchase Agreement”), with 56 purchasers (the "2012 Purchasers"). Under the terms of the 2012 Purchase Agreement, the 2012 Purchasers purchased from Park an aggregate principal amount of $30 million of 7% Subordinated Notes due April 20, 2022 (the "2012 Notes"). The 2012 Notes were intended to qualify as Tier 2 capital under applicable rules and regulations of the FRB. The 2012 Notes could not be prepaid in any amount prior to April 21, 2017; however, subsequent to that date, Park could prepay, without penalty, all or a portion of the principal amount outstanding. On April 24, 2017, Park prepaid in full the $30 million outstanding aggregate principal amount of the 2012 Notes, plus accrued interest on the 2012 Notes in the aggregate amount of $140,000 .

Contingent Liabilities Continge

Contingent Liabilities Contingent Liabilities	12 Months Ended
	Dec. 31, 2017
Loss Contingencies [Line Items]
Commitments and Contingencies Disclosure [Text Block]	Contingent Liabilities The Company is a defendant in lawsuits and other adversary proceedings arising in the ordinary course of business. Legal costs incurred in connection with the resolution of claims and lawsuits are generally expensed as incurred, and the Company establishes accruals for the outcome of litigation where losses are deemed probable and reasonably estimable. The Company’s assessment of the current exposure could change in the event of the discovery of additional facts with respect to legal matters pending against the Company or determinations by judges, juries, administrative agencies or other finders of fact that are not in accordance with the Company’s evaluation of claims. As of December 31, 2016, the Company had accrued charges of approximately $2.3 million for legal contingencies related to various legal and other adversary proceedings. This amount was paid out in full settlement of the related litigation during the year ended December 31, 2017. As of December 31, 2017, the Company had accrued charges of approximately $20,000 for legal contingencies related to various legal and other adversary proceedings.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Option Plan	Share-Based Compensation The Park National Corporation 2013 Long-Term Incentive Plan (the "2013 Incentive Plan") was adopted by the Board of Directors of Park on January 28, 2013 and was approved by Park's shareholders at the Annual Meeting of Shareholders on April 22, 2013. The 2013 Incentive Plan made equity-based awards and cash-based awards available for grant to participants in the form of incentive stock options, nonqualified stock options, stock appreciation rights ("SARs"), restricted common shares ("Restricted Stock"), restricted stock unit awards that may be settled in common shares, cash or a combination of the two ("Restricted Stock Units"), unrestricted common shares ("Other Stock-Based Awards") and cash-based awards. Under the 2013 Incentive Plan, 600,000 common shares were authorized to be delivered in connection with grants under the 2013 Incentive Plan. The common shares to be delivered under the 2013 Incentive Plan are to consist of either common shares currently held or common shares subsequently acquired by Park as treasury shares, including common shares purchased in the open market or in private transactions. At December 31, 2017, there were 116,716 common shares subject to performance-based restricted stock units (“PBRSUs”) issued under the 2013 Incentive Plan. The Park National Corporation 2017 Long-Term Incentive Plan for Employees (the "2017 Employees LTIP") was adopted by the Board of Directors of Park on January 23, 2017 and was approved by Park's shareholders at the Annual Meeting of Shareholders on April 24, 2017. The 2017 Employees LTIP makes equity-based awards and cash-based awards available for grant to participants in the form of incentive stock options, nonqualified stock options, SARs, Restricted Stock, Restricted Stock Units, Other Stock-Based Awards and cash-based awards. Under the 2017 Employees LTIP, 750,000 common shares are authorized to be delivered in connection with grants under the 2017 Employees LTIP. The common shares to be delivered under the 2017 Employees LTIP are to consist of either common shares currently held or common shares subsequently acquired by Park as treasury shares, including common shares purchased in the open market or in private transactions. At December 31, 2017, 750,000 common shares were available for future grants under the 2017 Employee LTIP. The Park National Corporation 2017 Long-Term Incentive Plan for Non-Employee Directors (the "2017 Non-Employee Directors LTIP") was adopted by the Board of Directors of Park on January 23, 2017 and was approved by Park's shareholders at the Annual Meeting of Shareholders on April 24, 2017. The 2017 Non-Employee Directors LTIP makes equity-based awards and cash-based awards available for grant to participants in the form of nonqualified stock options, SARs, Restricted Stock, Restricted Stock Units, Other Stock-Based Awards, and cash-based awards. Under the 2017 Non-Employee Directors LTIP, 150,000 common shares are authorized to be delivered in connection with grants under the 2017 Non-Employee Directors LTIP. The common shares to be delivered under the 2017 Non-Employee Directors LTIP are to consist of either common shares currently held or common shares subsequently acquired by Park as treasury shares, including common shares purchased in the open market or in private transactions. At December 31, 2017, 138,850 common shares were available for future grants under the 2017 Non-Employee Directors LTIP. The 2017 Employees LTIP and the 2017 Non-Employee Directors LTIP have replaced the provisions of the 2013 Incentive Plan with respect to the grant of future awards. As a result of the approval of the 2017 Employees LTIP and the 2017 Non-Employee Directors LTIP, Park will not grant any additional awards under the 2013 Incentive Plan after April 24, 2017. Awards made under the 2013 Incentive Plan prior to April 24, 2017 will remain in effect in accordance with their respective terms. During 2017, Park granted 11,150 common shares to directors of Park and to directors of Park's bank subsidiary PNB (and its divisions) under the 2017 Non-Employee Directors LTIP. During 2016 and 2015, Park granted 9,950 , and 10,150 common shares, respectively, to directors of Park and to directors of Park's bank subsidiary PNB (and its divisions) under the 2013 Incentive Plan. The common shares granted to directors were not subject to a vesting period and resulted in expense of $1.2 million , $950,000 , and $963,000 in 2017, 2016, and 2015, respectively, which is included in professional fees and services on the Consolidated Statements of Income. During 2017, 2016 and 2015, the Compensation Committee of the Board of Directors of Park granted awards of PBRSUs covering an aggregate of 45,788 , 41,550 and 23,025 , respectively, of common shares, under the 2013 Incentive Plan, to certain employees of Park and its subsidiaries. The number of PBRSUs earned or settled will depend on on the level of achievement with respect to certain performance criteria and are also subject to subsequent service-based vesting requirements. A summary of changes in the common shares subject to nonvested PBRSUs for the years ended December 31, 2017 and 2016 follows: Common shares subject to PBRSUs Nonvested at January 1, 2016 44,700 Granted 41,550 Vested — Forfeited (825 ) Nonvested at January 1, 2017 85,425 Granted 45,788 Vested (9,674 ) Forfeited (3,021 ) Adjustment for performance conditions of PBRSUs (1) (1,802 ) Nonvested at December 31, 2017 (2) 116,716 (1) The number of PBRSUs earned depends on the level of achievement with respect to certain performance criteria. Adjustment herein represents the difference between the maximum number of common shares which could be earned and the actual number earned for those PBRSUs as to which the performance period was completed. (2) Nonvested amount herein represents the maximum number of nonvested PBRSUs. As of December 31, 2017, 103,319 PBRSUs are expected to vest. On March 31, 2017, 9,674 PBRSUs granted in 2014 vested in full due to the level of achievement with respect to certain performance criteria and the satisfaction of the service-based vesting requirement. A total of 3,293 common shares were withheld to pay employee income taxes. This resulted in a net amount of 6,381 common shares being issued to employees of Park. Share-based compensation expense of $2.7 million , $1.9 million and $865,000 was recognized for the years ended December 31, 2017 , 2016 and 2015, respectively, related to PBRSU awards to employees. The following table details expected additional share-based compensation expense related to PBRSUs currently outstanding: (In thousands) 2018 $ 2,446 2019 1,818 2020 822 2021 137 Total $ 5,223

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2017
Defined Benefit Plan [Abstract]
Benefit Plans	Benefit Plans The Corporation has a noncontributory Defined Benefit Pension Plan (the “Pension Plan”) covering substantially all of the employees of the Corporation and its subsidiaries. The Pension Plan provides benefits based on an employee’s years of service and compensation. There was no pension contribution in 2016 . During 2017 , management contributed $15.0 million , of which $15.0 million was deductible on the 2017 tax return. There is no contribution expected in 2018. Using an accrual measurement date of December 31, 2017 and 2016 , plan assets and benefit obligation activity for the Pension Plan are listed below: (In thousands) 2017 2016 Change in fair value of plan assets Fair value at beginning of measurement period $ 167,047 $ 153,498 Actual return on plan assets 21,573 19,256 Employer contributions 15,000 — Benefits paid (7,885 ) (5,707 ) Fair value at end of measurement period $ 195,735 $ 167,047 Change in benefit obligation Projected benefit obligation at beginning of measurement period $ 114,455 $ 102,245 Service cost 5,270 5,055 Interest cost 5,085 4,869 Actuarial loss 21,773 7,993 Benefits paid (7,885 ) (5,707 ) Projected benefit obligation at the end of measurement period $ 138,698 $ 114,455 Funded status at end of year (fair value of plan assets less benefit obligation) $ 57,037 $ 52,592 The increase in the actuarial loss from $8.0 million as of December 31, 2016 to $21.8 million as of December 31, 2017, was the result of changes in actuarial assumptions partially offset by greater than projected returns on pension plan assets during 2017. Changes in actuarial assumptions included a change in the discount rate from 4.58% to 3.89% as well as a change in the generational mortality improvement projection scale from scale MP-2016 to scale MP-2017. The asset allocation for the Pension Plan as of each measurement date, by asset category, was as follows: Percentage of Plan Assets Asset category Target Allocation 2017 2016 Equity securities 50% - 100% 79 % 84 % Fixed income and cash equivalents remaining balance 21 % 16 % Total 100 % 100 % The investment policy, as established by the Retirement Plan Committee, is to invest assets according to the target allocation stated above. Assets will be reallocated periodically based on the investment strategy of the Retirement Plan Committee. The investment policy is reviewed periodically. The expected long-term rate of return on plan assets used to measure the benefit obligation was 7.00% at both December 31, 2017 and December 31, 2016 . This return was based on the expected return of each of the asset categories, weighted based on the median of the target allocation for each class. The accumulated benefit obligation for the Pension Plan was $116.0 million and $97.2 million at December 31, 2017 and 2016 , respectively. On November 17, 2009, the Park Pension Plan completed the purchase of 115,800 common shares of Park for $7.0 million or $60.45 per share. At December 31, 2017 and 2016 , the fair value of the 115,800 common shares held by the Pension Plan was $12.0 million , or $104.00 per share and $13.9 million , or $119.66 per share, respectively. The weighted average assumptions used to determine benefit obligations at December 31, 2017 , 2016 and 2015 were as follows: 2017 2016 2015 Discount rate 3.89 % 4.58 % 4.88 % Rate of compensation increase Under age 30 10.00 % 10.00 % 10.00 % Ages 30-39 6.00 % 6.00 % 6.00 % Ages 40-49 4.00 % 4.00 % 3.00 % Ages 50 and over 3.00 % 3.00 % 3.00 % The estimated future pension benefit payments reflecting expected future service for the next ten years are shown below (in thousands): 2018 $ 8,274 2019 8,404 2020 9,320 2021 10,526 2022 10,937 2023-2027 53,456 Total $ 100,917 The following table shows ending balances of accumulated other comprehensive loss at December 31, 2017 and 2016 . (In thousands) 2017 2016 Prior service cost $ — $ — Net actuarial loss (33,799 ) (22,677 ) Total (33,799 ) (22,677 ) Deferred taxes 7,098 7,937 Disparate tax effect (1) 3,175 — Accumulated other comprehensive loss $ (23,526 ) $ (14,740 ) (1) In accordance with U.S. GAAP, Park revalued the deferred tax asset related to net actuarial loss upon the enactment of the Tax Cuts and Jobs Act on December 22, 2017. U.S. GAAP does not allow for a similar revaluation of accumulated other comprehensive loss, resulting in a disparate tax effect. Park adopted ASU 2018-02 on January 1, 2018, which allows for the reclassification of the disparate tax effect to retained earnings. Using an actuarial measurement date of December 31 for 2017 , 2016 and 2015 , components of net periodic benefit income and other amounts recognized in other comprehensive income were as follows: (In thousands) 2017 2016 2015 Components of net periodic benefit income and other amounts recognized in other comprehensive income Service cost $ (5,270 ) $ (5,055 ) $ (5,368 ) Interest cost (5,085 ) (4,869 ) (4,695 ) Expected return on plan assets 11,455 10,950 11,420 Amortization of prior service cost — — (15 ) Recognized net actuarial loss (576 ) (773 ) (637 ) Net periodic benefit income $ 524 $ 253 $ 705 Change to net actuarial (loss) gain for the period $ (11,698 ) $ 168 $ (1,400 ) Amortization of prior service cost — — 15 Amortization of net loss 576 773 637 Total recognized in other comprehensive income (11,122 ) 941 (748 ) Total recognized in net benefit income and other comprehensive income $ (10,598 ) $ 1,194 $ (43 ) There are no estimated prior service costs for the Pension Plan to be amortized from accumulated other comprehensive loss into net periodic benefit cost over the next fiscal year. The estimated net actuarial loss expected to be recognized in the next fiscal year is $1.4 million . The weighted average assumptions used to determine net periodic benefit income for the years ended December 31, 2017 , 2016 and 2015 are listed below: 2017 2016 2015 Discount Rate 4.58 % 4.88 % 4.42 % Rate of compensation increase Under age 30 10.00 % 10.00 % 10.00 % Ages 30-39 6.00 % 6.00 % 6.00 % Ages 40-49 4.00 % 3.00 % 3.00 % Ages 50 and over 3.00 % 3.00 % 3.00 % Expected long-term return on plan assets 7.00 % 7.25 % 7.25 % The Pension Plan maintains cash in a PNB savings account. The Pension Plan cash balance was $12.2 million at December 31, 2017 . GAAP defines fair value as the price that would be received by Park for an asset or paid by Park to transfer a liability (an exit price) in an orderly transaction between market participants on the measurement date, using the most advantageous market for the asset or liability. The fair values of equity securities, consisting of mutual fund investments and common stock (U.S. large cap) held by the Pension Plan and the fixed income and cash equivalents, are determined by obtaining quoted prices on nationally recognized securities exchanges (Level 1 inputs). The fair value of Pension Plan assets at December 31, 2017 was $195.7 million . At December 31, 2017 , $169.6 million of equity investments and cash in the Pension Plan were categorized as Level 1 inputs; $26.1 million of plan investments in corporate (U.S. large cap) and U.S. Government sponsored entity bonds were categorized as Level 2 inputs, as fair value was based on quoted market prices of comparable instruments; and no investments were categorized as Level 3 inputs. The fair value of Pension Plan assets was $167.0 million at December 31, 2016 . At December 31, 2016 , $145.9 million of investments in the Pension Plan were categorized as Level 1 inputs; $21.1 million were categorized as Level 2; and no investments were categorized as Level 3. The Corporation has a voluntary salary deferral plan covering substantially all of the employees of the Corporation and its subsidiaries. Eligible employees may contribute a portion of their compensation subject to a maximum statutory limitation. The Corporation provides a matching contribution established annually by the Corporation. Contribution expense for the Corporation was $1.3 million , $1.3 million , and $1.2 million for 2017 , 2016 and 2015 , respectively. The Corporation has entered into Supplemental Executive Retirement Plan Agreements (the "SERP Agreements") with certain key officers of the Corporation and its subsidiaries which provide defined pension benefits in excess of limits imposed by federal tax law. The accrued benefit cost for the SERP Agreements totaled $9.9 million and $8.8 million for 2017 and 2016 , respectively. The expense for the Corporation was $1.7 million for 2017 , $1.5 million for 2016 and $1.1 million for 2015 .

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Deferred income taxes were recorded at a federal tax rate of 35% at December 31, 2016. On December 22, 2017, “H.R.1,” known as the “Tax Cuts and Jobs Act", was signed into law. Among other things, the Tax Cuts and Jobs Act permanently lowers the corporate federal income tax rate to 21% from the existing maximum rate of 35% , effective January 1, 2018. As a result of the reduction of the corporate federal income tax rate to 21% , U.S. generally accepted accounting principles require companies to revalue certain tax-related assets and liabilities as of the date of enactment, with the resulting tax effects accounted for in the reporting period of enactment. This revaluation impacted Park’s net deferred tax liabilities and qualified affordable housing tax credit investments. This revaluation resulted in a $1.9 million tax benefit as a result of the revaluation of Park’s net deferred tax liabilities offset by $3.1 million in tax expense as a result of the accelerated amortization of qualified affordable housing tax credit investments. The net effect of the Tax Cuts and Jobs Act was an increase to federal income tax expense at Park of $1.2 million . Also on December 22, 2017, the U.S. Securities and Exchange Commission (“SEC”) released Staff Accounting Bulletin No. 118 (“SAB 118”) to address any uncertainty or diversity of views in practice in accounting for the income tax effect of the Tax Cuts and Jobs Act in situations where a registrant does not have the necessary information available, prepared, or analyzed in reasonable detail to complete this accounting in the reporting period that includes the enactment date. SAB 118 allows for a measurement period not to extend beyond one year from the Tax Cut and Jobs Act’s enactment date to complete the necessary accounting. We recorded provisional amounts of deferred income taxes using reasonable estimates in one area where the information necessary to complete the accounting was not available, prepared, or analyzed. Our deferred tax liability for temporary differences associated with equity investments in partnerships is awaiting receipt of Schedules K-1 from outside preparers, which is necessary to determine our 2017 impact from these investments. We made no adjustments to deferred tax assets representing future deductions for accrued compensation that may be subject to new limitations under Internal Revenue Code Section 162(m) which, generally, limits the annual deduction for certain compensation paid to certain employees to $1 million. There is uncertainty in applying the newly-enacted rules to existing contracts, and Park is seeking further clarifications before completing our analysis. We will complete and record the income tax effects of these provisional items during the period the necessary information becomes available. This measurement period will not extend beyond December 22, 2018. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Corporation’s deferred tax assets and liabilities are as follows: December 31 (In thousands) 2017 2016 Deferred tax assets: Allowance for loan losses $ 10,498 $ 17,719 Accumulated other comprehensive loss – Pension plan 7,098 7,937 Accumulated other comprehensive loss – Unrealized losses on securities 946 1,618 Deferred compensation 2,744 4,140 OREO valuation adjustments 1,327 2,322 Net deferred loan fees 1,115 1,397 Deferred contract bonus 645 1,074 Nonvested equity-based compensation 1,069 1,115 Fixed assets 877 781 Accrued litigation 4 793 Other 1,226 2,525 Total deferred tax assets $ 27,549 $ 41,421 Deferred tax liabilities: Deferred investment income 6,120 10,199 Pension plan 19,076 26,344 Mortgage servicing rights 2,034 3,243 Partnership adjustments 460 549 Other 364 596 Total deferred tax liabilities $ 28,054 $ 40,931 Net deferred tax (liability) asset $ (505 ) $ 490 Park performs an analysis to determine if a valuation allowance against deferred tax assets is required in accordance with GAAP. Management has determined that it is not required to establish a valuation allowance against the December 31, 2017 or 2016 deferred tax assets in accordance with GAAP since it is more likely than not that the deferred tax assets will be fully utilized in future periods. The components of the provision for federal income taxes are shown below: December 31, (In thousands) 2017 2016 2015 Currently payable Federal $ 20,660 $ 28,879 $ 26,153 Amortization of qualified affordable housing projects 10,278 7,300 6,664 Deferred Federal 3,289 581 (250 ) Total $ 34,227 $ 36,760 $ 32,567 The following is a reconciliation of income tax expense to the amount computed at the statutory rate of 35% for the years ended December 31, 2017 , 2016 and 2015 . 2017 2016 2015 Statutory federal corporate tax rate 35.0 % 35.0 % 35.0 % Changes in rates resulting from: Tax exempt interest income, net of disallowed interest (2.8 )% (1.3 )% (0.5 )% Bank owned life insurance (1.4 )% (1.2 )% (1.8 )% Investments in qualified affordable housing projects, net of tax benefits (1.9 )% (1.7 )% (1.9 )% Other tax credits — % — % (0.9 )% KSOP dividend deduction (1.0 )% (1.0 )% (1.0 )% Impact of the Tax Cuts and Jobs Act (1) 1.0 % — % — % Other — % 0.1 % (0.2 )% Effective tax rate 28.9 % 29.9 % 28.7 % (1) As a result of the reduction of the corporate federal income tax rate to 21% , U.S. generally accepted accounting principles require companies to re-value certain tax-related assets and liabilities as of the date of enactment, with the resulting tax effects accounted for in the reporting period of enactment. This re-valuation resulted in a $1.9 million tax benefit as a result of the revaluation of Park’s net deferred tax liabilities and $3.1 million in tax expense as a result of accelerated amortization of qualified affordable housing tax credit investments. The net effect of the Tax Cuts and Jobs Act was an increase to federal income tax expense at Park of $1.2 million . Park and its subsidiaries do not pay state income tax to the state of Ohio, but pay a franchise tax based on equity. The franchise tax expense is included in "State tax expense" on Park’s Consolidated Statements of Income. Unrecognized Tax Benefits The following is a reconciliation of the beginning and ending amount of unrecognized tax benefits. (In thousands) 2017 2016 2015 January 1 Balance $ 633 $ 558 $ 532 Additions based on tax positions related to the current year 117 117 80 Additions for tax positions of prior years — 38 16 Reductions for tax positions of prior years (9 ) — — Reductions due to statute of limitations (77 ) (80 ) (70 ) December 31 Balance $ 664 $ 633 $ 558 The amount of unrecognized tax benefits that, if recognized, would favorably affect the effective income tax rate in the future periods at December 31, 2017 , 2016 and 2015 was $506,000 , $482,000 and $432,000 , respectively. Park does not expect the total amount of unrecognized tax benefits to significantly increase or decrease during the next year. The expense related to interest and penalties recorded on unrecognized tax benefits in the Consolidated Statements of Income for the years ended December 31, 2017 , 2016 , and 2015 was $3,500 , $1,500 , and $2,000 , respectively. The amount accrued for interest and penalties at December 31, 2017 , 2016 and 2015 was $74,000 , $70,500 and $69,000 , respectively. Park and its subsidiaries are subject to U.S. federal income tax and income tax in various state jurisdictions. The Corporation is subject to routine audits of tax returns by the Internal Revenue Service and states in which we conduct business. No material adjustments have been made on closed federal and state tax audits. Generally, all tax years ended prior to December 31, 2014 are closed to examination by federal and state taxing authorities.

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2017
Other Comprehensive Income (Loss) [Abstract]
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) Other comprehensive income (loss) components, net of income tax, are shown in the following table for the years ended December 31, 2017 , 2016 and 2015 . Year ended December 31, (in thousands) Changes in Pension Plan assets and benefit obligations Unrealized gains and losses on available-for-sale securities Total Beginning balance at January 1, 2017 $ (14,740 ) $ (3,005 ) $ (17,745 ) Other comprehensive (loss) gain before reclassifications (9,241 ) 1,261 (7,980 ) Amounts reclassified from accumulated other comprehensive loss 455 (1,184 ) (729 ) Net current period other comprehensive (loss) income (8,786 ) 77 (8,709 ) Ending balance at December 31, 2017 $ (23,526 ) $ (2,928 ) $ (26,454 ) Beginning balance at January 1, 2016 $ (15,351 ) $ (292 ) $ (15,643 ) Other comprehensive gain (loss) before reclassifications 109 (2,713 ) (2,604 ) Amounts reclassified from accumulated other comprehensive loss 502 — 502 Net current period other comprehensive income (loss) 611 (2,713 ) (2,102 ) Ending balance at December 31, 2016 $ (14,740 ) $ (3,005 ) $ (17,745 ) Beginning balance at January 1, 2015 $ (14,865 ) $ 1,257 $ (13,608 ) Other comprehensive loss before reclassifications (910 ) (1,549 ) (2,459 ) Amounts reclassified from accumulated other comprehensive loss 424 — 424 Net current period other comprehensive loss (486 ) (1,549 ) (2,035 ) Ending balance at December 31, 2015 $ (15,351 ) $ (292 ) $ (15,643 ) The following table provides information concerning amounts reclassified out of accumulated other comprehensive loss for the years ended December 31, 2017 , 2016 and 2015 : Amount Reclassified from Accumulated Other Comprehensive Loss Affected Line Item in the Consolidated Statement of Income (In thousands) 2017 2016 2015 Amortization of defined benefit pension items Amortization of prior service cost $ — $ — $ 15 Employee benefits Amortization of net loss 576 773 637 Employee benefits Income before income taxes 576 773 652 Income before income taxes Federal income taxes 121 271 228 Federal income taxes Net of income tax $ 455 $ 502 $ 424 Net of income tax Unrealized gains & losses on available for sale securities Gain on sale of investment securities $ (1,821 ) $ — $ — Gain on sale of investment securities Other than temporary impairment — — — Miscellaneous expense Income before income taxes (1,821 ) — — Income before income taxes Federal income taxes (637 ) — — Federal income taxes Net of income tax $ (1,184 ) $ — $ — Net of income tax

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share GAAP requires the reporting of basic and diluted earnings per common share. Basic earnings per common share excludes any dilutive effects of PBRSUs. The following table sets forth the computation of basic and diluted earnings per common share: Year ended December 31 2017 2016 2015 Numerator: Net income $ 84,242 $ 86,135 $ 81,012 Denominator: Weighted-average common shares outstanding 15,295,573 15,332,553 15,364,281 Effect of dilutive PBRSUs 94,779 72,607 40,459 Weighted-average common shares outstanding adjusted for the effect of dilutive PBRSUs 15,390,352 15,405,160 15,404,740 Earnings per common share: Basic earnings per common share $ 5.51 $ 5.62 $ 5.27 Diluted earnings per common share $ 5.47 $ 5.59 $ 5.26 Park awarded 45,788 , 41,550 and 23,025 PBRSUs to certain employees during the years ended December 31, 2017, 2016 and 2015, respectively. As of December 31, 2017, 116,716 PBRSUs were outstanding. The PBRSUs vest based on service and performance conditions. The dilutive effect of the PBRSUs was the addition of 94,779 , 72,607 and 40,459 common shares for the years ended December 31, 2017, 2016 and 2015, respectively. During the years ended December 31, 2017 and 2015, Park repurchased 70,000 and 71,700 common shares, respectively, to fund the PBRSUs and common shares awarded to directors of Park and to directors of Park's subsidiary PNB (and its divisions). No common shares were repurchased during 2016.

Dividend Restrictions

Dividend Restrictions	12 Months Ended
	Dec. 31, 2017
Disclosure of Restrictions on Dividends, Loans and Advances Disclosure [Abstract]
Dividend Restrictions	Dividend Restrictions Bank regulators limit the amount of dividends a subsidiary bank can declare in any calendar year without obtaining prior approval. At December 31, 2017 , approximately $76.1 million of the total shareholders’ equity of PNB was available for the payment of dividends to the Corporation, without approval by the applicable regulatory authorities.

Financial Instruments With Off-

Financial Instruments With Off-Balance Sheet Risk And Financial Instruments With Concentrations Of Credit Risk	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
Financial Instruments with Off-Balance Sheet Risk and Financial Instruments with Concentration of Credit Risk	Financial Instruments with Off-Balance Sheet Risk and Financial Instruments with Concentrations of Credit Risk The Corporation is party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include loan commitments and standby letters of credit. The instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the consolidated financial statements. The Corporation’s exposure to credit loss in the event of nonperformance by the other party to the financial instrument for loan commitments and standby letters of credit is represented by the contractual amount of those instruments. The Corporation uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments. Since many of the loan commitments may expire without being drawn upon, the total commitment amount does not necessarily represent future cash requirements. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan commitments to customers. The total amounts of off-balance sheet financial instruments with credit risk were as follows: December 31 (In thousands) 2017 2016 Loan commitments $ 893,205 $ 912,007 Standby letters of credit 13,421 13,746 The loan commitments are generally for variable rates of interest. The Corporation grants retail, commercial and commercial real estate loans to customers primarily located in Ohio. The Corporation evaluates each customer’s creditworthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by the Corporation upon extension of credit, is based on management’s credit evaluation of the customer. Collateral held varies but may include accounts receivable, inventory, property, plant and equipment, and income-producing commercial properties. Although the Corporation has a diversified loan portfolio, a substantial portion of the borrowers’ ability to honor their contracts is dependent upon the economic conditions in each borrower’s geographic location and industry.

Loan Servicing

Loan Servicing	12 Months Ended
	Dec. 31, 2017
Transfers and Servicing of Financial Assets [Abstract]
Loan Servicing	Loan Servicing Park serviced sold mortgage loans of $1,371 million at December 31, 2017 , compared to $1,330 million at December 31, 2016 and $1,276 million at December 31, 2015 . At December 31, 2017 , $3.0 million of the sold mortgage loans were sold with recourse compared to $4.1 million at December 31, 2016 and $5.4 million at December 31, 2015 . Management closely monitors the delinquency rates on the mortgage loans sold with recourse. As of December 31, 2017 and 2016, management had established a reserve of $270,000 and $266,000 , respectively, to account for future loan repurchases. When Park sells mortgage loans with servicing rights retained, servicing rights are initially recorded at fair value. Park selected the “amortization method” as permissible within U.S. GAAP, whereby the servicing rights capitalized are amortized in proportion to and over the period of estimated future servicing income of the underlying loan. At the end of each reporting period, the carrying value of mortgage servicing rights (“MSRs”) is assessed for impairment with a comparison to fair value. MSRs are carried at the lower of their amortized cost or fair value. The amortization of MSRs is included within other service income in the Consolidated Statements of Income. Activity for MSRs and the related valuation allowance follows: December 31 (In thousands) 2017 2016 2015 MSRs: Carrying amount, net, beginning of year $ 9,266 $ 9,008 $ 8,613 Additions 1,941 2,286 1,748 Amortization (1,624 ) (1,835 ) (1,637 ) Change in valuation allowance 105 (193 ) 284 Carrying amount, net, end of year $ 9,688 $ 9,266 $ 9,008 Valuation allowance: Beginning of year $ 735 $ 542 $ 826 Change in valuation allowance (105 ) 193 (284 ) End of year $ 630 $ 735 $ 542 The fair value of MSRs was $9.7 million and $9.3 million at December 31, 2017 and 2016, respectively. The fair value of MSRs at December 31, 2017 was established using a discount rate of 13% and constant prepayment speeds ranging from 6.54% to 17.10% . The fair value of MSRs at December 31, 2016 was established using a discount rate of 13% and constant prepayment speeds ranging from 6.24% to 16.80% . Servicing fees included in other service income were $3.5 million , $3.4 million and $3.4 million for the years ended December 31, 2017, 2016 and 2015, respectively.

Fair Values

Fair Values	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Values	Fair Value The fair value hierarchy requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The three levels of inputs that Park uses to measure fair value are as follows: • Level 1: Quoted prices (unadjusted) for identical assets or liabilities in active markets that Park has the ability to access as of the measurement date. • Level 2: Level 1 inputs for assets or liabilities that are not actively traded. Also consists of an observable market price for a similar asset or liability. This includes the use of “matrix pricing” to value debt securities absent the exclusive use of quoted prices. • Level 3: Consists of unobservable inputs that are used to measure fair value when observable market inputs are not available. This could include the use of internally developed models, financial forecasting and similar inputs. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability between market participants at the balance sheet date. When possible, the Company looks to active and observable markets to price identical assets or liabilities. When identical assets and liabilities are not traded in active markets, the Company looks to observable market data for similar assets and liabilities. However, certain assets and liabilities are not traded in observable markets and Park must use other valuation methods to develop a fair value. The fair value of impaired loans is typically based on the fair value of the underlying collateral, which is estimated through third-party appraisals or internal estimates of collateral values in accordance with Park's valuation requirements per its commercial and real estate loan policies. Assets and Liabilities Measured at Fair Value on a Recurring Basis : The following table presents assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements at December 31, 2017 using: (In thousands) Level 1 Level 2 Level 3 Balance at December 31, 2017 Assets Investment securities: Obligations of U.S. Treasury and other U.S. Government sponsored entities $ — $ 242,720 $ — $ 242,720 U.S. Government sponsored entities’ asset-backed securities — 849,161 — 849,161 Equity securities 1,518 — 417 1,935 Mortgage loans held for sale — 4,148 — 4,148 Mortgage IRLCs — 94 — 94 Liabilities Fair value swap $ — $ — $ 226 $ 226 Fair Value Measurements at December 31, 2016 using: (In thousands) Level 1 Level 2 Level 3 Balance at December 31, 2016 Assets Investment securities: Obligations of U.S. Treasury and other U.S. Government sponsored entities $ — $ 267,533 $ — $ 267,533 U.S. Government sponsored entities’ asset-backed securities — 987,172 — 987,172 Equity securities 2,644 — 790 3,434 Mortgage loans held for sale — 10,413 — 10,413 Mortgage IRLCs — 124 — 124 Liabilities Fair value swap $ — $ — $ 226 $ 226 There were no transfers between Level 1 and Level 2 during 2017 or 2016 . Management’s policy is to transfer assets or liabilities from one level to another when the methodology to obtain the fair value changes such that there are more or fewer unobservable inputs as of the end of the reporting period. The following methods and assumptions were used by the Company in determining fair value of the financial assets and liabilities discussed above: Investment securities: Fair values for investment securities are based on quoted market prices, where available. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments. For securities where quoted prices or market prices of similar securities are not available, fair values are calculated using discounted cash flows. Fair value swap: The fair value of the swap agreement entered into with the purchaser of the Visa Class B shares represents an internally developed estimate of the exposure based upon probability-weighted potential Visa litigation losses. Mortgage Interest Rate Lock Commitments (IRLCs): IRLCs are based on current secondary market pricing and are classified as Level 2. Mortgage loans held for sale: Mortgage loans held for sale are carried at their fair value. Mortgage loans held for sale are estimated using security prices for similar product types and, therefore, are classified in Level 2. The table below is a reconciliation of the beginning and ending balances of the Level 3 inputs for the years ended December 31, 2017 and 2016 , for financial instruments measured on a recurring basis and classified as Level 3: Level 3 Fair Value Measurements (In thousands) Equity Securities Fair Value Swap Balance at January 1, 2017 $ 790 $ (226 ) Total Gains (Losses) Included in other comprehensive income 6 — Transfers out of Level 3 (1) (346 ) — Purchases, sales, issuances and settlements, other, net (33 ) — Balance at December 31, 2017 $ 417 $ (226 ) Balance at January 1, 2016 $ 769 $ (226 ) Total Gains (Losses) Included in other comprehensive income 21 — Balance at December 31, 2016 $ 790 $ (226 ) (1) Transfered from Level 3 to Level 1 as the result of a quoted market price becoming available. Assets and liabilities measured at fair value on a nonrecurring basis: The following methods and assumptions were used by the Company in determining the fair value of assets and liabilities measured at fair value on a nonrecurring basis described below: Impaired Loans: At the time a loan is considered impaired, it is valued at the lower of cost or fair value. Impaired loans carried at fair value have been partially charged off or receive specific allocations of the allowance for loan losses. For collateral dependent loans, fair value is generally based on real estate appraisals. These appraisals may utilize a single valuation approach or a combination of approaches including the comparable sales approach and the income approach. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between the comparable sales and income data available. Such adjustments result in a Level 3 classification of the inputs for determining fair value. Collateral is then adjusted or discounted based on management’s historical knowledge, changes in market conditions from the time of the valuation, and management’s expertise and knowledge of the client and client’s business, also resulting in a Level 3 fair value classification. Impaired loans are evaluated on a quarterly basis for additional impairment and adjusted accordingly. Additionally, updated independent valuations are obtained annually for all impaired loans in accordance with Company policy. Other Real Estate Owned ("OREO"): Assets acquired through or in lieu of loan foreclosure are initially recorded at fair value less costs to sell when acquired. The carrying value of OREO is not re-measured to fair value on a recurring basis, but is subject to fair value adjustments when the carrying value exceeds the fair value, less estimated selling costs. Fair value is based on recent real estate appraisals and is updated at least annually. These appraisals may utilize a single valuation approach or a combination of approaches including the comparable sales approach and the income approach. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between the comparable sales and income data available. Such adjustments result in a Level 3 classification of the inputs for determining fair value. Appraisals for both collateral dependent impaired loans and OREO are performed by licensed appraisers. Appraisals are generally obtained to support the fair value of collateral. In general, there are three types of appraisals received by the Company: real estate appraisals, income approach appraisals and lot development loan appraisals. These are discussed below: • Real estate appraisals typically incorporate measures such as recent sales prices for comparable properties. Appraisers may make adjustments to the sales prices of the comparable properties as deemed appropriate based on the age, condition or general characteristics of the subject property. Management generally applies a 15% discount to real estate appraised values which management expects will cover all disposition costs (including selling costs). This 15% is based on historical discounts to appraised values on sold OREO properties. • Income approach appraisals typically incorporate the annual net operating income of the business divided by an appropriate capitalization rate, as determined by the appraiser. Management generally applies a 15% discount to income approach appraised values which management expects will cover all disposition costs (including selling costs). • Lot development loan appraisals are typically performed using a discounted cash flow analysis. Appraisers determine an anticipated absorption period and a discount rate that takes into account an investor’s required rate of return based on recent comparable sales. Management generally applies a 6% discount to lot development appraised values, which is an additional discount above the net present value calculation included in the appraisal, to account for selling costs. MSRs: MSRs are carried at the lower of cost or fair value. MSRs do not trade in active, open markets with readily observable prices. For example, sales of MSRs do occur, but precise terms and conditions typically are not readily available. As such, management, with the assistance of a third-party specialist, determines fair value based on the discounted value of the future cash flows estimated to be received. Significant inputs include the discount rate and assumed prepayment speeds utilized. The calculated fair value is then compared to market values where possible to ascertain the reasonableness of the valuation in relation to current market expectations for similar products. Accordingly, MSRs are classified as Level 2. The following tables present assets and liabilities measured at fair value on a nonrecurring basis. Collateral dependent impaired loans are carried at fair value if they have been charged down to fair value or if a specific valuation allowance has been established. A new cost basis is established at the time a property is initially recorded in OREO. OREO properties are carried at fair value if a devaluation has been taken to the property's value subsequent to the initial measurement. Fair Value Measurements at December 31, 2017 Using: (In thousands) Level 1 Level 2 Level 3 Balance at December 31, 2017 Impaired Loans: Commercial real estate $ — $ — $ 2,735 $ 2,735 Construction real estate — — 127 127 Residential real estate — — 712 712 Total impaired loans recorded at fair value $ — $ — $ 3,574 $ 3,574 MSRs $ — $ 7,316 $ — $ 7,316 OREO: Commercial real estate — — 2,295 2,295 Construction real estate — — 3,204 3,204 Residential real estate — — 1,021 1,021 Total OREO recorded at fair value $ — $ — $ 6,520 $ 6,520 Fair Value Measurements at December 31, 2016 Using: (In thousands) Level 1 Level 2 Level 3 Balance at December 31, 2016 Impaired Loans: Commercial real estate $ — $ — $ 3,057 $ 3,057 Construction real estate — — 541 541 Residential real estate — — 2,385 2,385 Total impaired loans recorded at fair value $ — $ — $ 5,983 $ 5,983 MSRs $ — $ 6,769 $ — $ 6,769 OREO: Commercial real estate — — 2,644 2,644 Construction real estate — — 3,322 3,322 Residential real estate — — 931 931 Total OREO recorded at fair value $ — $ — $ 6,897 $ 6,897 The table below provides additional detail on those impaired loans which are recorded at fair value as well as the remaining impaired loan portfolio not included above. The remaining impaired loans consist of loans which are not collateral dependent as well as loans carried at cost as the fair value of the underlying collateral or the present value of expected future cash flows on each of the loans exceeded the book value for each respective credit. December 31, 2017 (In thousands) Recorded Investment Prior Charge-Offs Specific Valuation Allowance Carrying Balance Impaired loans recorded at fair value $ 3,577 $ 2,780 $ 3 $ 3,574 Remaining impaired loans 52,987 7,260 681 52,306 Total impaired loans $ 56,564 $ 10,040 $ 684 $ 55,880 December 31, 2016 (In thousands) Recorded Investment Prior Charge-Offs Specific Valuation Allowance Carrying Balance Impaired loans recorded at fair value $ 6,379 $ 3,681 $ 396 $ 5,983 Remaining impaired loans 64,047 21,262 152 63,895 Total impaired loans $ 70,426 $ 24,943 $ 548 $ 69,878 The (expense) income from credit adjustments related to impaired loans carried at fair value for the years ended December 31, 2017 , 2016 and 2015 was $(1.6) million , $0.9 million , and $(2.1) million , respectively. MSRs totaled $9.7 million at December 31, 2017 . Of this $9.7 million MSR carrying balance, $7.3 million was recorded at fair value and included a valuation allowance of $0.6 million . The remaining $2.4 million was recorded at cost, as the fair value exceeded cost at December 31, 2017 . At December 31, 2016 , MSRs totaled $9.3 million . Of this $9.3 million MSR carrying balance, $6.8 million was recorded at fair value and included a valuation allowance of $0.7 million . T he remaining $2.5 million was recorded at cost, as the fair value exceeded cost at December 31, 2016 . The income (expense) related to MSRs carried at fair value for the years ended December 31, 2017 , 2016 and 2015 was $0.1 million , $(0.2) million and $0.3 million , respectively. Total OREO held by Park at December 31, 2017 and 2016 was $14.2 million and $13.9 million , respectively. Approximately 46% and 50% of OREO held by Park at December 31, 2017 and 2016 , respectively, was carried at fair value due to fair value adjustments made subsequent to the initial OREO measurement. At December 31, 2017 and 2016 , OREO held at fair value, less estimated selling costs, amounted to $6.5 million and $6.9 million , respectively. The net expense related to OREO fair value adjustments was $0.5 million , $0.6 million and $1.6 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. The following tables present quantitative information about Level 3 fair value measurements for financial instruments measured at fair value on a non-recurring basis at December 31, 2017 and December 31, 2016 : December 31, 2017 (In thousands) Fair Value Valuation Technique Unobservable Input(s) Range (Weighted Average) Impaired loans: Commercial real estate $ 2,735 Sales comparison approach Adj to comparables 0.0% - 90.0% (22.7%) Income approach Capitalization rate 9.0% - 11.0% (9.9%) Cost approach Accumulated depreciation 90.1% (90.1%) Construction real estate $ 127 Sales comparison approach Adj to comparables 0.0% - 4.8% (2.4%) Residential real estate $ 712 Sales comparison approach Adj to comparables 0.3% - 33.0% (12.5%) Income approach Capitalization rate 10.5% (10.5%) Other real estate owned: Commercial real estate $ 2,295 Sales comparison approach Adj to comparables 0.9% - 68.4% (34.7%) Income approach Capitalization rate 13.0% (13.0%) Construction real estate $ 3,204 Sales comparison approach Adj to comparables 0.0% - 90.0% (24.5%) Bulk sale approach Discount rate 15.0% (15.0%) Residential real estate $ 1,021 Sales comparison approach Adj to comparables 1.2% - 79.7% (31.8%) December 31, 2016 (In thousands) Fair Value Valuation Technique Unobservable Input(s) Range (Weighted Average) Impaired loans: Commercial real estate $ 3,057 Sales comparison approach Adj to comparables 0.0% - 90.0% (20.2%) Income approach Capitalization rate 9.0% - 10.6% (10.1%) Cost approach Accumulated depreciation 17.0% - 18.0% (17.8%) Construction real estate $ 541 Sales comparison approach Adj to comparables 0.0% - 11.1% (1.6%) Bulk sale approach Discount rate 10.0% (10.0%) Residential real estate $ 2,385 Sales comparison approach Adj to comparables 0.3% - 110.0% (17.0%) Income approach Capitalization rate 10.0% (10.0%) Other real estate owned: Commercial real estate $ 2,644 Sales comparison approach Adj to comparables 0.0% - 68.4% (26.5%) Income approach Capitalization rate 13.0% - 14.0% (13.1%) Construction real estate $ 3,322 Sales comparison approach Adj to comparables 0.0% - 90.0% (24.7%) Bulk sale approach Discount rate 15.0% (15.0%) Residential real estate $ 931 Sales comparison approach Adj to comparables 3.2% - 79.7% (30.6%) The following methods and assumptions were used by the Corporation in estimating its fair value disclosures for assets and liabilities not discussed above: Cash and cash equivalents: The carrying amounts reported in the Consolidated Balance Sheets for cash and short-term instruments approximate those assets’ fair values. Other investments: FHLB stock and FRB stock within other investments are carried at their respective redemption values as it is not practical to calculate their fair values. Additional investments within this category are carried at their cost basis as these investments do not have a readily determinable fair value and Park does not have the ability to influence the operating or financial decisions of the investee. Loans receivable: For variable-rate loans that reprice frequently and with no significant change in credit risk, fair values are based on carrying values. The fair values for certain mortgage loans (e.g., one-to-four family residential) are based on quoted market prices of similar loans sold in conjunction with securitization transactions, adjusted for differences in loan characteristics. The fair values for other loans are estimated using discounted cash flow analyses, based upon interest rates currently being offered for loans with similar terms to borrowers of similar credit quality. The methods utilized to estimate fair value do not necessarily represent an exit price. Off-balance sheet instruments: Fair values for the Corporation’s loan commitments and standby letters of credit are based on the fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and the counterparties’ credit standing. The carrying amount and fair value are not material. Deposit liabilities: The fair values disclosed for demand deposits (e.g., interest and non-interest checking, savings, and money market accounts) are, by definition, equal to the amount payable on demand at the reporting date (i.e., their carrying amounts). The carrying amounts for variable-rate, fixed-term certificates of deposit approximate their fair values at the reporting date. Fair values for fixed-rate certificates of deposit are estimated using a discounted cash flow calculation that applies interest rates currently being offered on certificates to a schedule of aggregated expected monthly maturities of time deposits. Short-term borrowings: The carrying amounts of federal funds purchased, borrowings under repurchase agreements and other short-term borrowings approximate their fair values. Long-term debt: Fair values for long-term debt are estimated using a discounted cash flow calculation that applies interest rates currently being offered on long-term debt to a schedule of monthly maturities. Subordinated notes: Fair values for subordinated notes are estimated using a discounted cash flow calculation that applies interest rate spreads currently being offered on similar debt structures to a schedule of monthly maturities. The fair value of financial instruments at December 31, 2017 and December 31, 2016 , was as follows: December 31, 2017 Fair Value Measurements (In thousands) Carrying value Level 1 Level 2 Level 3 Total fair value Financial assets: Cash and money market instruments $ 169,112 $ 169,112 $ — $ — $ 169,112 Investment securities (1) 1,451,013 1,518 1,455,660 417 1,457,595 Accrued interest receivable - securities 5,505 — 5,505 — 5,505 Accrued interest receivable - loans 16,659 — — 16,659 16,659 Mortgage loans held for sale 4,148 — 4,148 — 4,148 Mortgage IRLCs 94 — 94 — 94 Impaired loans carried at fair value 3,574 — — 3,574 3,574 Other loans, net 5,314,679 — — 5,247,021 5,247,021 Loans receivable, net $ 5,322,495 $ — $ 4,242 $ 5,250,595 $ 5,254,837 Financial liabilities: Noninterest bearing checking accounts $ 1,633,941 $ 1,633,941 $ — $ — $ 1,633,941 Interest bearing transaction accounts 1,260,095 1,260,095 — — 1,260,095 Savings accounts 1,888,545 1,888,545 — — 1,888,545 Time deposits 1,033,476 — 1,035,093 — 1,035,093 Other 1,269 1,269 — — 1,269 Total deposits $ 5,817,326 $ 4,783,850 $ 1,035,093 $ — $ 5,818,943 Short-term borrowings $ 391,289 $ — $ 391,289 $ — $ 391,289 Long-term debt 500,000 — 504,503 — 504,503 Subordinated notes 15,000 — 13,370 — 13,370 Accrued interest payable – deposits 1,211 77 1,134 — 1,211 Accrued interest payable – debt/borrowings 1,067 11 1,056 — 1,067 Derivative financial instruments: Fair value swap $ 226 $ — $ — $ 226 $ 226 (1) Investment securities excludes the category "Other investment securities." This category consists of FHLB and FRB stock carried at their respective redemption values as it is not practical to calculate their fair values. Additional investments within "Other investment securities" are carried at their cost basis as these investments do not have a readily determinable fair value and Park does not have the ability to influence the operating or financial decisions of the investee. December 31, 2016 Fair Value Measurements (In thousands) Carrying value Level 1 Level 2 Level 3 Total fair value Financial assets: Cash and money market instruments $ 146,466 $ 146,466 $ — $ — $ 146,466 Investment securities (1) 1,517,972 2,644 1,511,377 790 1,514,811 Accrued interest receivable - securities 3,849 — 3,849 — 3,849 Accrued interest receivable - loans 14,973 — — 14,973 14,973 Loans held for sale 10,413 — 10,413 — 10,413 Mortgage IRLCs 124 — 124 — 124 Impaired loans carried at fair value 5,983 — — 5,983 5,983 Other loans, net 5,204,713 — — 5,161,919 5,161,919 Loans receivable, net $ 5,221,233 $ — $ 10,537 $ 5,167,902 $ 5,178,439 Financial liabilities: Noninterest bearing checking accounts $ 1,523,417 $ 1,523,417 $ — — $ 1,523,417 Interest bearing transaction accounts 1,174,448 1,174,448 — — 1,174,448 Savings accounts 1,704,920 1,704,920 — — 1,704,920 Time deposits 1,117,870 — 1,122,598 — 1,122,598 Other 1,301 1,301 — — 1,301 Total deposits $ 5,521,956 $ 4,404,086 $ 1,122,598 $ — $ 5,526,684 Short-term borrowings $ 394,795 $ — $ 394,795 $ — $ 394,795 Long-term debt 694,281 — 712,958 — 712,958 Subordinated notes 45,000 — 40,903 — 40,903 Accrued interest payable – deposits 900 82 818 — 900 Accrued interest payable – debt/borrowings 1,251 1 1,250 — 1,251 Derivative financial instruments: Fair value swap $ 226 $ — $ — $ 226 $ 226 (1) Investment securities excludes the category "Other investment securities." This category consists of FHLB and FRB stock carried at their respective redemption values as it is not practical to calculate their fair values. Additional investments within "Other investment securities" are carried at their cost basis as these investments do not have a readily determinable fair value and Park does not have the ability to influence the operating or financial decisions of the investee.

Capital Ratios

Capital Ratios	12 Months Ended
	Dec. 31, 2017
Capital [Abstract]
Capital Ratios	Capital Ratios Financial institution regulators have established guidelines for minimum capital ratios for banks, thrifts and bank holding companies. During the first quarter of 2015, Park adopted the Basel III regulatory capital framework as approved by the federal banking agencies. The adoption of this framework modified the calculation of the various capital ratios, added an additional ratio, common equity tier 1, and revised the adequately and well-capitalized thresholds under the prompt corrective action regulations applicable to PNB. Additionally, under this framework, in order to avoid limitations on capital distributions, including dividend payments, Park must hold a capital conservation buffer above the adequately capitalized risk-based capital ratios. The capital conservation buffer is being phased in from 0.0% for 2015 to 2.50% by 2019. The capital conservation buffer was 1.25% for 2017 and 0.625% for 2016. The amounts shown below as the adequately capitalized ratio plus capital conservation buffer includes the fully phased-in 2.50% buffer. The Federal Reserve Board also adopted requirements Park must maintain to be deemed "well-capitalized" and to remain a financial holding company. Each of PNB and Park met each of the well-capitalized ratio guidelines applicable to it at December 31, 2017. The following table indicates the capital ratios for PNB and Park at December 31, 2017 and 2016. As of December 31, 2017 Leverage Tier 1 Risk-Based Common Equity Tier 1 Total Risk-Based The Park National Bank 7.36 % 10.35 % 10.35 % 11.60 % Park National Corporation 9.44 % 13.22 % 12.94 % 14.14 % Adequately capitalized ratio 4.00 % 6.00 % 4.50 % 8.00 % Adequately capitalized ratio plus capital conservation buffer 4.00 % 8.50 % 7.00 % 10.50 % Well-capitalized ratio - PNB 5.00 % 8.00 % 6.50 % 10.00 % Well-capitalized ratio - Park N/A 6.00 % N/A 10.00 % As of December 31, 2016 Leverage Tier 1 Risk-Based Common Equity Tier 1 Total Risk-Based The Park National Bank 7.34 % 9.87 % 9.87 % 11.24 % Park National Corporation 9.56 % 12.83 % 12.55 % 14.32 % Adequately capitalized ratio 4.00 % 6.00 % 4.50 % 8.00 % Adequately capitalized ratio plus capital conservation buffer 4.00 % 8.50 % 7.00 % 10.50 % Well-capitalized ratio - PNB 5.00 % 8.00 % 6.50 % 10.00 % Well-capitalized ratio - Park N/A 6.00 % N/A 10.00 % The following table reflects various measures of capital for Park and PNB: To Be Adequately Capitalized To Be Well-Capitalized (In thousands) Actual Amount Ratio Amount Ratio Amount Ratio At December 31, 2017 Total Risk-Based Capital PNB $ 628,440 11.60 % $ 433,406 8.00 % $ 541,757 10.00 % Park 775,867 14.14 % 438,981 8.00 % 548,726 10.00 % Tier 1 Risk-Based Capital PNB $ 560,530 10.35 % $ 325,054 6.00 % $ 433,406 8.00 % Park 725,221 13.22 % 329,235 6.00 % 329,235 6.00 % Leverage Ratio PNB $ 560,530 7.36 % $ 304,722 4.00 % $ 380,903 5.00 % Park 725,221 9.44 % 307,441 4.00 % N/A N/A Common Equity Tier 1 PNB $ 560,530 10.35 % $ 243,791 4.50 % $ 352,142 6.50 % Park 710,221 12.94 % 246,927 4.50 % N/A N/A At December 31, 2016 Total Risk-Based Capital PNB $ 607,269 11.24 % $ 432,153 8.00 % $ 540,192 10.00 % Park 784,406 14.32 % 438,231 8.00 % 547,789 10.00 % Tier 1 Risk-Based Capital PNB $ 533,215 9.87 % $ 324,115 6.00 % $ 432,153 8.00 % Park 702,651 12.83 % 328,673 6.00 % 328,673 6.00 % Leverage Ratio PNB $ 533,215 7.34 % $ 290,671 4.00 % $ 363,339 5.00 % Park 702,651 9.56 % 293,916 4.00 % N/A N/A Common Equity Tier 1 PNB 533,215 9.87 % 243,086 4.50 % 351,125 6.50 % Park 687,651 12.55 % 246,505 4.50 % N/A N/A

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Information	Segment Information The Corporation is a financial holding company headquartered in Newark, Ohio. The operating segments for the Corporation are its chartered national bank subsidiary, PNB (headquartered in Newark, Ohio), SEPH and GFSC. GAAP requires management to disclose information about the different types of business activities in which a company engages and also information on the different economic environments in which a company operates, so that the users of the financial statements can better understand a company’s performance, better understand the potential for future cash flows, and make more informed judgments about the company as a whole. Park’s current operating segments are in line with GAAP as: (i) discrete financial information is available for each operating segment and (ii) the segments are aligned with internal reporting to Park’s Chief Executive Officer and President, who is the chief operating decision-maker. Operating results for the year ended December 31, 2017 (In thousands) PNB GFSC SEPH All Other Total Net interest income $ 235,243 $ 5,839 $ 2,089 $ 588 $ 243,759 Provision for (recovery of) loan losses 9,898 1,917 (3,258 ) — 8,557 Other income 77,126 40 404 3,065 80,635 Other expense 180,275 3,036 5,252 8,805 197,368 Income (loss) before taxes 122,196 926 499 (5,152 ) 118,469 Income taxes (benefit) 34,881 666 1,375 (2,695 ) 34,227 Net income (loss) $ 87,315 $ 260 $ (876 ) $ (2,457 ) $ 84,242 Balances at December 31, 2017 Assets $ 7,467,851 $ 32,077 $ 24,902 $ 12,790 $ 7,537,620 Loans 5,339,255 33,385 10,891 (11,048 ) 5,372,483 Deposits 5,896,676 3,449 — (82,799 ) 5,817,326 Operating results for the year ended December 31, 2016 (In thousands) PNB GFSC SEPH All Other Total Net interest income (loss) $ 227,576 $ 5,874 $ 4,774 $ (138 ) $ 238,086 Provision for (recovery of) loan losses 2,611 1,887 (9,599 ) — (5,101 ) Other income (loss) 74,803 (1 ) 2,974 955 78,731 Other expense 177,562 4,457 7,273 9,731 199,023 Income (loss) before taxes 122,206 (471 ) 10,074 (8,914 ) 122,895 Income taxes (benefit) 37,755 (164 ) 3,526 (4,357 ) 36,760 Net income (loss) $ 84,451 $ (307 ) $ 6,548 $ (4,557 ) $ 86,135 Balances at December 31, 2016 Assets $ 7,389,538 $ 32,268 $ 25,342 $ 20,438 $ 7,467,586 Loans 5,234,828 32,661 12,354 (7,986 ) 5,271,857 Deposits 5,630,199 3,809 — (112,052 ) 5,521,956 Operating results for the year ended December 31, 2015 (In thousands) PNB GFSC SEPH All Other Total Net interest income (loss) $ 220,879 $ 6,588 $ (74 ) $ 239 $ 227,632 Provision for (recovery of) loan losses 7,665 1,415 (4,090 ) — 4,990 Other income 75,188 2 1,848 513 77,551 Other expense 167,476 2,984 6,182 9,972 186,614 Income (loss) before taxes 120,926 2,191 (318 ) (9,220 ) 113,579 Income taxes (benefit) 36,581 768 (111 ) (4,671 ) 32,567 Net income (loss) $ 84,345 $ 1,423 $ (207 ) $ (4,549 ) $ 81,012 Balances at December 31, 2015 Assets $ 7,229,764 $ 35,793 $ 33,541 $ 12,256 $ 7,311,354 Loans 5,029,072 35,469 15,153 (11,609 ) 5,068,085 Deposits 5,447,293 4,627 — (104,278 ) 5,347,642 The following is a reconciliation of financial information for the reportable segments to the Corporation’s consolidated totals: 2017 (In thousands) Net Interest Income Depreciation Expense Other Expense Income Taxes Assets Deposits Totals for reportable segments $ 243,171 $ 8,644 $ 179,919 $ 36,922 $ 7,524,830 $ 5,900,125 Elimination of intersegment items 1,500 — — — (14,679 ) (82,799 ) Parent Co. totals - not eliminated (912 ) — 8,805 (2,695 ) 27,469 — Totals $ 243,759 $ 8,644 $ 188,724 $ 34,227 $ 7,537,620 $ 5,817,326 2016 (In thousands) Net Interest Income Depreciation Expense Other Expense Income Taxes Assets Deposits Totals for reportable segments $ 238,224 $ 8,396 $ 180,896 $ 41,117 $ 7,447,148 $ 5,634,008 Elimination of intersegment items 2,164 — — — (9,204 ) (112,052 ) Parent Co. totals - not eliminated (2,302 ) — 9,731 (4,357 ) 29,642 — Totals $ 238,086 $ 8,396 $ 190,627 $ 36,760 $ 7,467,586 $ 5,521,956 2015 (In thousands) Net Interest Income Depreciation Expense Other Expense Income Taxes Assets Deposits Totals for reportable segments $ 227,393 $ 7,347 $ 169,295 $ 37,238 $ 7,299,098 $ 5,451,920 Elimination of intersegment items 2,561 — — — (13,557 ) (104,278 ) Parent Co. totals - not eliminated (2,322 ) — 9,972 (4,671 ) 25,813 — Totals $ 227,632 $ 7,347 $ 179,267 $ 32,567 $ 7,311,354 $ 5,347,642

Parent Company Statements

Parent Company Statements	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Parent Company Statements	Parent Company Statements The Parent Company statements should be read in conjunction with the consolidated financial statements and the information set forth below. Investments in subsidiaries are accounted for using the equity method of accounting. Cash represents non-interest bearing deposits with PNB. Net cash provided by operating activities reflects cash payments (received from subsidiaries) for income taxes of $3.3 million , $4.4 million and $4.1 million in 2017 , 2016 and 2015 , respectively. At December 31, 2017 and 2016 , shareholders’ equity reflected in the Parent Company balance sheet includes $282.6 million and $259.7 million , respectively, of undistributed earnings of the Corporation’s subsidiaries which are restricted from transfer as dividends to the Corporation. Condensed Balance Sheets December 31, 2017 and 2016 (In thousands) 2017 2016 Assets: Cash $ 79,452 $ 112,067 Investment in subsidiaries 645,287 626,569 Debentures receivable from PNB 25,000 25,000 Other investments 1,398 2,962 Other assets 26,838 26,651 Total assets $ 777,975 $ 793,249 Liabilities: Subordinated notes 15,000 45,000 Other liabilities 6,874 6,009 Total liabilities 21,874 51,009 Total shareholders’ equity 756,101 742,240 Total liabilities and shareholders’ equity $ 777,975 $ 793,249 Condensed Statements of Income for the years ended December 31, 2017, 2016 and 2015 (In thousands) 2017 2016 2015 Income: Dividends from subsidiaries $ 60,000 $ 60,000 $ 60,000 Interest and dividends 1,500 2,164 2,561 Gain on sale of investment securities 1,821 — — Other 1,405 1,081 560 Total income 64,726 63,245 63,121 Expense: Interest expense 1,073 2,429 2,369 Other, net 8,805 9,730 9,972 Total expense 9,878 12,159 12,341 Income before federal taxes and equity in undistributed income of subsidiaries 54,848 51,086 50,780 Federal income tax benefit 2,695 4,357 4,671 Income before equity in undistributed income of subsidiaries 57,543 55,443 55,451 Equity in undistributed income of subsidiaries 26,699 30,692 25,561 Net income $ 84,242 $ 86,135 $ 81,012 Other comprehensive loss (1) (8,709 ) (2,102 ) (2,035 ) Comprehensive income 75,533 84,033 78,977 (1) See Consolidated Statements of Comprehensive Income for other comprehensive loss detail. Statements of Cash Flows for the years ended December 31, 2017, 2016 and 2015 (In thousands) 2017 2016 2015 Operating activities: Net income $ 84,242 $ 86,135 $ 81,012 Adjustments to reconcile net income to net cash provided by operating activities: Undistributed income of subsidiaries (26,699 ) (30,692 ) (25,561 ) Compensation expense for issuance of treasury stock to directors 1,241 950 963 Share-based compensation expense 2,701 1,864 865 Realized net investment security gains (1,821 ) — — Decrease (increase) in other assets 205 (3,425 ) (182 ) Increase (decrease) in other liabilities 475 (2,524 ) 485 Net cash provided by operating activities 60,344 52,308 57,582 Investing activities: Proceeds from sales of securities 2,265 — — Repayment of investments in and advances to subsidiaries — 15,000 10,000 Net cash provided by investing activities 2,265 15,000 10,000 Financing activities: Cash dividends paid (57,493 ) (57,653 ) (57,776 ) Repayment of subordinated notes (30,000 ) — — Repurchase of treasury shares (7,378 ) — (6,058 ) Cash payment for fractional shares (6 ) (4 ) (3 ) Value of common shares withheld to pay employee income taxes (347 ) — — Net cash used in financing activities (95,224 ) (57,657 ) (63,837 ) (Decrease) increase in cash (32,615 ) 9,651 3,745 Cash at beginning of year 112,067 102,416 98,671 Cash at end of year $ 79,452 $ 112,067 $ 102,416

Subsequent Event Business Combi

Subsequent Event Business Combinations	12 Months Ended
	Dec. 31, 2017
Business Acquisition [Line Items]
Schedule of Business Acquisitions by Acquisition, Contingent Consideration [Table Text Block]	Subsequent Events On January 22, 2018, Park, PNB and NewDominion Bank, a North Carolina state-chartered bank ("NewDominion"), entered into an Agreement and Plan of Merger and Reorganization (the "NewDominion Merger Agreement"), pursuant to which NewDominion will merge with and into PNB (the "NewDominion Merger"). Subject to the terms and conditions of the NewDominion Merger Agreement, at the effective time of the NewDominion Merger (the "NewDominion Effective Time"), NewDominion shareholders will have the right to receive for each share of NewDominion's voting and non-voting common stock, par value $0.25 per share, at their election either (i) $1.08 in cash or (ii) 0.01023 Park Common Shares (the "NewDominion Merger Consideration"), subject to required proration in the event that cash or Common Shares are oversubscribed as provided in the NewDominion Merger Agreement. At the NewDominion Effective Time, outstanding NewDominion stock options with an exercise price of less than $1.08 per share will be canceled and converted into the right to receive the NewDominion Merger Consideration with the same election right as NewDominion shareholders, subject to proration. Each outstanding NewDominion stock option with an exercise price of $1.08 per share or more will be assumed and converted into an option to purchase Park Common Shares, on the same terms and conditions as were applicable under such NewDominion stock option. At the NewDominion Effective Time, NewDominion restricted stock awards will fully vest (with any performance-based vesting condition deemed satisfied) and will be canceled and converted automatically into the right to receive the NewDominion Merger Consideration, with the same election right as New Dominion shareholders, subject to proration as provided in the NewDominion Merger Agreement. The NewDominion Merger Agreement contains customary representations, warranties, and covenants of each party. Subject to certain terms and conditions, the NewDominion Merger Agreement provides that the board of directors of NewDominion will recommend the approval and adoption of the NewDominion Merger Agreement by the shareholders of NewDominion. NewDominion has also agreed not to solicit acquisition proposals relating to alternative business combination transactions. In addition, NewDominion has agreed not to participate in discussions or negotiations or provide information in connection with any acquisition proposals for alternative business combination transactions unless certain conditions are satisfied. Closing of the NewDominion Merger is subject to customary conditions, including, among others, approval of the NewDominion Merger Agreement by NewDominion’s shareholders, receipt of required regulatory approvals, effectiveness of the registration statement to be filed by Park, and approval for listing on NYSE AMERICAN, with respect to the Park Common Shares to be issued in the NewDominion Merger. The NewDominion Merger Agreement provides certain termination rights for each party and further provides that, in the event the NewDominion Merger Agreement is terminated under certain circumstances in connection with a competing acquisition transaction, NewDominion will be required to pay Park a termination fee equal to $4,170,000 . In connection with the NewDominion Merger Agreement, Park and Park National Bank entered into voting and support agreements with the directors and executive officers of NewDominion, in those individuals’ capacities as shareholders, and with certain substantial shareholders of NewDominion. Pursuant to the terms of the voting and support agreements, each director and each executive officer of NewDominion and those certain substantial shareholders of NewDominion have agreed to vote the shares of NewDominion common stock they own in favor of the NewDominion Merger Agreement, subject to the exceptions set forth in the voting agreements.

Summary of Significant Accoun39

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of Park National Corporation and its subsidiaries (“Park”, the “Company” or the “Corporation”). Material intercompany accounts and transactions have been eliminated.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles ("GAAP") requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates.
Reclassifications	Reclassifications Certain prior year amounts have been reclassified to conform with the current year presentation. These reclassifications had no impact on net income or shareholders' equity.
Restrictions on Cash and Due from Banks	Restrictions on Cash and Due from Banks The Corporation’s national bank subsidiary, The Park National Bank ("PNB"), is required to maintain average reserve balances with the Federal Reserve Bank of Cleveland. The average required reserve balance was approximately $64.8 million at December 31, 2017 and $51.6 million at December 31, 2016 . No other compensating balance arrangements were in existence at December 31, 2017 .
Investment Securities	Investment Securities Investment securities are classified upon acquisition into one of three categories: held-to-maturity ("HTM"), available-for-sale ("AFS"), or trading (see Note 4 - Investment Securities). HTM securities are those securities that the Corporation has the positive intent and ability to hold to maturity and are recorded at amortized cost. AFS securities are those securities that would be available to be sold in the future in response to the Corporation’s liquidity needs, changes in market interest rates, and asset-liability management strategies, among other reasons. AFS securities are reported at fair value, with unrealized holding gains and losses excluded from earnings but included in other comprehensive income (loss), net of applicable income taxes. The Corporation did not hold any trading securities during any period presented. AFS and HTM securities are evaluated quarterly for potential other-than-temporary impairment. Management considers the facts related to each security including the nature of the security, the amount and duration of the loss, the credit quality of the issuer, the expectations for that security’s performance and whether Park intends to sell, or it is more likely than not that Park will be required to sell, a security in an unrealized loss position before recovery of its amortized cost basis. Declines in the value of equity securities that are considered to be other-than-temporary are recorded as a charge to earnings in the Consolidated Statements of Income. Declines in the value of debt securities that are considered to be other-than-temporary are separated into (1) the amount of the total impairment related to credit loss and (2) the amount of the total impairment related to all other factors. The amount of the total other-than-temporary impairment related to the credit loss is recognized in earnings. The amount of the total other-than-temporary impairment related to all other factors is recognized in other comprehensive income (loss), net of income tax. Interest income from investment securities includes amortization of purchase premium or discount. Premiums and discounts on securities are amortized on the level-yield method without anticipating prepayments, except for mortgage-backed securities where prepayments are anticipated. Gains and losses realized on the sale of investment securities are recorded on the trade date and determined using the specific identification basis.
Federal Home Loan Bank (FHLB) and Federal Reserve Bank (FRB) Stock	Federal Home Loan Bank ("FHLB") and Federal Reserve Bank of Cleveland ("FRB") Stock Park’s national bank subsidiary, PNB, is a member of the FHLB. Additionally, PNB is a member of the FRB. Members are required to own a certain amount of stock based on their level of borrowings and other factors and may invest in additional amounts. FHLB stock and FRB stock are classified as restricted securities and are carried at their redemption value within other investment securities on the Consolidated Balance Sheets. Impairment is evaluated based on the ultimate recovery of par value. Both cash and stock dividends are reported as income.
Bank Owned Life Insurance	Bank Owned Life Insurance Park has purchased insurance policies on the lives of directors and certain key officers. Bank owned life insurance is recorded at its cash surrender value (or the amount that can be realized).
Mortgage Loans Held For Sale	Loans Held for Sale Park has elected the fair value option for mortgage loans held for sale, which are carried at their fair value as of each balance sheet date.
Mortgage Banking Derivatives	Mortgage Banking Derivatives Commitments to fund mortgage loans (interest rate locks) to be sold into the secondary market and forward commitments for the future delivery of these mortgage loans are accounted for as free standing derivatives. The fair value of the interest rate lock is recorded at the time the commitment to fund the mortgage loan is executed and is adjusted for the expected exercise of the commitment before the loan is funded. In order to hedge the change in interest rates resulting from its commitments to fund the loans, the Company interest into forward commitments for the future delivery of mortgage loans when interest rate locks are entered into. Fair value of these mortgage derivatives are estimated based on change in mortgage interest rates from the date the interest on the loan is locked. Changes in the fair values of these derivatives are included in other service income in the Consolidated Statements of Income.
Loans	Loans Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff, are reported at their outstanding principal balances adjusted for any charge-offs, any nonaccrual interest payments applied to principal, any deferred fees or costs on originated loans, and any unamortized premiums or discounts on purchased loans. Interest income is accrued on the unpaid principal balance. Late charges on loans are recognized as income when they are collected. Net loan origination fees and costs are deferred and recognized in interest income using the level-yield method without anticipating prepayments. Commercial loans include: (1) commercial, financial and agricultural loans; (2) commercial real estate loans; (3) those commercial loans in the real estate construction loan segment; and (4) those commercial loans in the residential real estate loan segment. Consumer loans include: (1) mortgage and installment loans included in the real estate construction segment; (2) mortgage, home equity lines of credit ("HELOCs"), and installment loans included in the residential real estate segment; and (3) all loans included in the consumer segment. Generally, commercial loans are placed on nonaccrual status at 90 days past due and consumer and residential mortgage loans are placed on nonaccrual status at 120 days past due. Commercial loans placed on nonaccrual status are considered impaired (see Note 5 - Loans). For loans which are on nonaccrual status, it is Park’s policy to reverse interest previously accrued on the loans against interest income. Interest on such loans may be recorded on a cash basis and be included in earnings only when Park expects to receive the entire recorded investment of the loan. Park’s charge-off policy for commercial loans requires management to establish a specific reserve or record a charge-off when collection is in doubt or it is probable a loss has been incurred and there is, or likely will be, a collateral shortfall related to the estimated value of the collateral securing the loan. The Company’s charge-off policy for consumer loans is dependent on the class of the loan. Residential mortgage loans, HELOCs, and consumer loans secured by residential real estate are typically charged down to the value of the collateral, less estimated selling costs, at 180 days past due. The charge-off policy for other consumer loans, primarily installment loans, requires a monthly review of delinquent loans and a complete charge-off for any account that reaches 120 days past due. The delinquency status of a loan is based on contractual terms and not on how recently payments have been received. Loans may be removed from nonaccrual status when loan payments have been received to cure the delinquency status, the borrower has demonstrated the ability to maintain current payment status in accordance with the loan agreement and the loan is deemed to be well-secured by management. A description of each segment of the loan portfolio, along with the risk characteristics of each segment, is included below: Commercial, financial and agricultural: Commercial, financial and agricultural ("C&I") loans are made for a wide variety of general corporate purposes, including financing for commercial and industrial businesses, financing for equipment, inventories and accounts receivable, acquisition financing, commercial leasing, and to consumer finance companies. The term of each commercial loan varies by its purpose. Repayment terms are structured such that commercial loans will be repaid within the economic useful life of the underlying asset. The commercial loan portfolio of Park’s current subsidiaries includes loans to a wide variety of corporations and businesses across many industrial classifications in the 29 Ohio counties where PNB and its divisions operate, with the exception of nationwide aircraft loans and nationwide asset based lending to consumer finance companies. The primary industries represented by these customers include real estate rental and leasing, finance and insurance, construction, agriculture, forestry, fishing and hunting, manufacturing, retail trade, health care and other services. Risk of loss on C&I loans largely depends upon general economic cycles, as they may adversely impact certain industries, competency of the borrower's management team, the quality of the underlying assets supporting the loans including accounts receivable, inventory, and equipment, and the accuracy of the borrower's financial reporting. Such risks are mitigated by generally requiring the borrower's owners to guaranty the loans. Commercial real estate: Commercial real estate (“CRE”) loans include mortgage loans to developers and owners of commercial real estate. The lending policy for CRE loans is designed to address the unique risk attributes of CRE lending. The collateral for these CRE loans is the underlying commercial real estate. Risk of loss on CRE loans largely depends upon the cash flow of the properties which is influenced by the amount of vacancy experienced by the underlying real estate, the credit capacity of the tenants occupying the underlying real estate, and general economic trends as they may adversely impact the value of the property. These risks are mitigated by generally requiring personal guaranties of the owners of the properties and by requiring appraisals pursuant to government regulations. Construction real estate : The Company defines construction loans as both commercial construction loans and residential construction loans where the loan proceeds are used exclusively for the improvement of real estate as to which the Company holds a mortgage. Construction loans may be in the form of a permanent loan or a short-term construction loan, depending on the needs of the individual borrower. Construction financing is generally considered to involve a higher degree of risk of loss than long-term financing on improved, occupied real estate. Risk of loss on a construction loan depends largely upon the accuracy of the initial estimate of the property’s value at completion of construction and the estimated cost (including interest) of construction. If the estimate of construction cost proves to be inaccurate, the PNB division making the loan may be required to advance funds beyond the amount originally committed to permit completion of the project. If the estimate of value proves inaccurate, the PNB division may be confronted, at or prior to the maturity of the loan, with a project having a value insufficient to assure full repayment, should the borrower default. In the event that a default on a construction loan occurs and foreclosure follows, the PNB division must take control of the project and attempt to either arrange for completion of construction or dispose of the unfinished project. Additional risk exists with respect to loans made to developers who do not have a buyer for the property, as the developer may lack funds to pay the loan if the property is not sold upon completion. PNB and its divisions attempt to reduce such risks on loans to developers by requiring personal guarantees and reviewing current personal financial statements and tax returns as well as other projects undertaken by the developer. Residential real estate: The Company defines residential real estate loans as first mortgages on individuals’ primary residences or second mortgages of individuals’ primary residences in the form of HELOCs or installment loans. Credit approval for residential real estate loans requires demonstration of sufficient income to repay the principal and interest and the real estate taxes and insurance, stability of employment, an established credit record and an appraised value of the real estate securing the loan. Residential real estate loans typically have longer terms and higher balances with lower yields as compared to consumer loans, but generally carry lower risks of default. The Dodd-Frank Wall Street Reform and Consumer Protection Act requires creditors to make a reasonable and good faith determination of a consumer's ability to repay any consumer credit transaction secured by a dwelling. Documentation and verification of income within defined time frames and not-to-exceed limits is basis for affirming ability to repay. Risk of loss largely depends upon factors affecting the borrower's ability to repay as well as the general economic trends as they may adversely impact the value of the property. These risks are mitigated by completing a comprehensive underwriting of the borrower and by requiring appraisals pursuant to government regulations. Consumer: The Company originates direct and indirect consumer loans, primarily automobile loans, to customers in its primary market areas. Credit approval for consumer loans requires income sufficient to repay principal and interest due, stability of employment, an established credit record and sufficient collateral for secured loans. Consumer loans typically have shorter terms and lower balances with higher yields as compared to real estate mortgage loans, but generally carry higher risks of default. Consumer loan collections are dependent on the borrower’s financial stability, and thus are more likely to be affected by adverse personal circumstances.
Allowance for Loan Losses	Allowance for Loan Losses ("ALLL") The allowance for loan losses is that amount believed adequate to absorb probable incurred credit losses in the loan portfolio based on management’s evaluation of various factors. The determination of the allowance requires significant estimates, including the timing and amounts of expected cash flows on impaired loans, consideration of current economic conditions, and historical loss experience pertaining to pools of homogeneous loans, all of which may be susceptible to change. The allowance is increased through a provision for loan losses that is charged to earnings based on management’s quarterly evaluation of the factors previously mentioned and is reduced by charge-offs, net of recoveries. The allowance for loan losses includes both (1) an estimate of loss based on historical loss experience within both commercial and consumer loan categories with similar characteristics (“statistical allocation”) and (2) an estimate of loss based on an impairment analysis of each commercial loan that is considered to be impaired (“specific allocation”). Included in the statistical allocation is a reserve for troubled debt restructurings ("TDRs") within the consumer loan portfolio. Management performs a periodic evaluation to ensure the reserve calculated utilizing the statistical allocation is consistent with a reserve calculated under Accounting Standards Codification ("ASC") 310-10 - Receivables . In calculating the allowance for loan losses, management believes it is appropriate to consider historical loss rates that are comparable to the current period being analyzed, giving consideration to losses experienced over a full cycle. For the historical loss factor at December 31, 2017 , the Company utilized an annual loss rate (“historical loss experience”), calculated based on an average of the net charge-offs and the annual change in specific reserves for impaired commercial loans, experienced during 2010 through 2017 within the individual segments of the commercial and consumer loan categories. The 96 month historical loss period captures all annual periods subsequent to June 2009, the end of the most recent recession, thus encompassing the full economic cycle to date. The loss factor applied to Park’s consumer loan portfolio as of December 31, 2017 was based on the historical loss experience over the preceding 96 months, plus an additional judgmental reserve, increasing the total allowance for loan loss coverage in the consumer loan portfolio to approximately 1.92 years of historical losses, compared to 1.95 years at December 31, 2016 . Historical loss experience over the preceding 96 months for the consumer loan portfolio was 0.34% for both 2017 and 2016. The loss factor applied to Park’s commercial loan portfolio as of December 31, 2017 was based on the historical loss experience over the preceding 96 months, plus additional reserves for consideration of (1) a loss emergence period factor, (2) a loss migration factor and (3) a judgmental or environmental loss factor. These additional reserves increased the total allowance for loan loss coverage in the commercial loan portfolio to approximately 3.24 years of historical losses at December 31, 2017, compared to 3.20 years at December 31, 2016 . Historical loss experience over the preceding 96 months for the commercial loan portfolio was 0.37% for 2017 and 0.39% for 2016. Park’s commercial loans are individually risk graded. If loan downgrades occur, the probability of default increases and accordingly management allocates a higher percentage reserve to those accruing commercial loans graded special mention and substandard. The judgmental increases discussed above incorporate management’s evaluation of the impact of environmental qualitative factors which pose additional risks and assign a component of the allowance for loan losses in consideration of these factors. Such environmental factors include: national and local economic trends and conditions; experience, ability and depth of lending management and staff; effects of any changes in lending policies and procedures; and levels of, and trends in, consumer bankruptcies, delinquencies, impaired loans and charge-offs and recoveries. GAAP requires a specific allocation to be established as a component of the allowance for loan losses for certain loans when it is probable that all amounts due pursuant to the contractual terms of the loans will not be collected, and the recorded investment in the loans exceeds their measure of impairment. Management considers the following related to commercial loans when determining if a loan should be considered impaired : (1) current debt service coverage levels of the borrowing entity; (2) payment history over the most recent 12-month period; (3) other signs of deterioration in the borrower’s financial situation, such as changes in credit scores; and (4) consideration of global cash flows of financially sound guarantors that have previously supported loan payments. The recorded investment is the balance of the loan, plus accrued interest receivable, both as of the end of the year. Impairment is measured using either the present value of expected future cash flows based upon the initial effective interest rate on the loan, or the fair value of the collateral. If a loan is considered to be collateral dependent, the fair value of collateral, less estimated selling costs, is used to measure impairment.
Troubled Debt Restructuring (TDRs)	Troubled Debt Restructuring Management classifies loans as TDRs when a borrower is experiencing financial difficulty and Park has granted a concession. In order to determine whether a borrower is experiencing financial difficulty, an evaluation is performed of the probability that the borrower will be in payment default on any of the borrower's debt in the foreseeable future without the modification. This evaluation is performed under the Company’s internal underwriting policy. Management’s policy is to modify loans by extending the term or by granting a temporary or permanent contractual interest rate below the market rate, not by forgiving debt. A court's discharge of a borrower's debt in a Chapter 7 bankruptcy is considered a concession when the borrower does not reaffirm the discharged debt. TDRs are measured at the present value of estimated future cash flows using the loan’s effective rate at inception, or if a TDR is considered to be a collateral dependent loan, the loan is reported, net, at the fair value of the collateral. Commercial TDRs are separately identified for impairment disclosures.
Premises and Equipment	Premises and Equipment Land is carried at cost and is not subject to depreciation. Premises and equipment are carried at cost, less accumulated depreciation and amortization. Depreciation is generally provided on the straight-line method over the estimated useful lives of the related assets. Leasehold improvements are amortized over the shorter of the remaining lease period or the estimated useful lives of the improvements. Upon the sale or other disposal of an asset, the cost and related accumulated depreciation are removed from the accounts and the resulting gain or loss is recognized. Maintenance and repairs are charged to expense as incurred while renewals and improvements that extend the useful life of an asset are capitalized. Premises and equipment are evaluated for impairment whenever events or changes in circumstances indicate that the carrying amount of a particular asset may not be recoverable. The range of depreciable lives over which premises and equipment are being depreciated are: Buildings 30 Years Equipment, furniture and fixtures 3 to 12 Years Leasehold improvements 1 to 10 Years
Other Real Estate Owned (OREO)	Other Real Estate Owned ("OREO") Management transfers a loan to OREO at the time that Park takes deed/title to the asset. OREO is initially recorded at fair value less anticipated selling costs (net realizable value), establishing a new cost basis, and consists of property acquired through foreclosure and real estate held for sale. If the net realizable value is below the carrying value of the loan at the date of transfer, the difference is charged to the allowance for loan losses. These assets are subsequently accounted for at the lower of cost or fair value less costs to sell. Subsequent changes in the value of real estate are classified as OREO valuation adjustments, are reported as adjustments to the carrying amount of OREO and are recorded within “Other income”. In certain circumstances where management believes the devaluation may not be permanent in nature, Park utilizes a valuation allowance to record OREO devaluations, which is also expensed through “Other income”. Costs relating to development and improvement of such properties are capitalized (not in excess of fair value less estimated costs to sell) and costs relating to holding the properties are charged to "Other expense".
Finance, Loan and Lease Receivables, Held for Investments, Foreclosed Assets Policy [Policy Text Block]	Foreclosed Assets Foreclosed assets include non-real estate assets where Park, as creditor, has received physical possession of a borrower’s assets, regardless of whether formal foreclosure proceedings take place. Additionally, troubled debt restructurings in which Park obtains one of more of the debtor’s non-real estate assets in place of all or part of the receivable are accounted for as foreclosed assets. Foreclosed assets are initially recorded as fair value less costs to sell when acquired, establishing a new cost basis. Operating costs after acquisition are expensed. As of December 31, 2017 and 2016, Park had $5.5 million and $0.6 million , respectively, of foreclosed assets included within “Other assets.”
Mortgage Loan Servicing Rights	Mortgage Servicing Rights ("MSR") When Park sells mortgage loans with servicing rights retained, servicing rights are recorded at fair value with the income statement effect recorded in "Other service income." Capitalized servicing rights are amortized in proportion to and over the period of the estimated future servicing income of the underlying loan and are included within “Other service income”. Mortgage servicing rights are assessed for impairment periodically, based on fair value, with any impairment recognized through a valuation allowance. The fair value of mortgage servicing rights is determined by discounting estimated future cash flows from the servicing assets, using market discount rates and expected future prepayment rates. In order to calculate fair value, the sold loan portfolio is stratified into homogeneous pools of like categories. (See Note 24 - Loan Servicing.) Fees received for servicing mortgage loans owned by investors are based on a percentage of the outstanding monthly principal balance of such loans and are included in income as loan payments are received. The cost of servicing loans is charged to expense as incurred to "Other service income".
Goodwill and Other Intangible Assets	Goodwill Goodwill represents the excess of the purchase price over net identifiable tangible and intangible assets acquired in a purchase business combination. Goodwill and indefinite-lived intangible assets are not amortized to expense, but are subject to impairment tests annually, or more frequently, if events or changes in circumstances indicate that the asset might be impaired, by assessing qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If after assessing these events or circumstances, it is concluded that it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then performing additional analysis is unnecessary. If the carrying amount of the goodwill exceeds the fair value, an impairment charge must be recorded in an amount equal to the excess, not to exceed the total goodwill allocated to the reporting unit. Management considers several factors when performing the annual impairment tests on goodwill. The factors considered include the operating results for the particular Park segment for the past year and the operating results budgeted for the current year (including multi-year projections), the deposit and loan totals of the Park segment and the economic conditions in the markets served by the Park segment. At December 31, 2017, the goodwill remaining on Park's Consolidated Balance Sheet consisted entirely of goodwill at PNB. (See Note 27 - Segment Information for operating segment results.) Park evaluates goodwill for impairment on April 1 of each year, with financial data as of March 31. Based on the analysis performed as of April 1, 2017, the Company determined that goodwill for Park’s national bank subsidiary (PNB) was not impaired. There have been no subsequent circumstances or events triggering an additional evaluation. Goodwill in the amount of $72.3 million was recorded at each of December 31, 2017, 2016, and 2015.
Consolidated Statement of Cash Flows	Consolidated Statement of Cash Flows Cash and cash equivalents include cash and cash items, amounts due from banks and money market instruments. Generally, money market instruments are purchased and sold for one-day periods.
Loss Contingencies and Guarantees	Loss Contingencies and Guarantees Loss contingencies, including claims and legal actions arising in the ordinary course of business, are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated.
Income Tax, Policy [Policy Text Block]	Income Taxes The Corporation accounts for income taxes using the asset and liability approach. Under this method, deferred tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. To the extent that Park does not consider it more likely than not that a deferred tax asset will be recovered, a valuation allowance is recorded. All positive and negative evidence is reviewed when determining how much of a valuation allowance is recognized on a quarterly basis. A valuation allowance, if needed, reduces deferred tax assets to the amount expected to be realized. An uncertain tax position is recognized as a benefit only if it is “more-likely-than-not” that the tax position would be sustained in a tax examination being presumed to occur. The benefit recognized for a tax position that meets the “more-likely-than-not” criteria is measured based on the largest benefit that is more than 50 percent likely to be realized, taking into consideration the amounts and probabilities of the outcome upon settlement. For tax positions not meeting the “more-likely-than-not” test, no tax benefit is recorded. Park recognizes any interest and penalties related to income tax matters in income tax expense.
Treasury Shares	Treasury Shares The purchase of Park’s common shares to be held in treasury is recorded at cost. At the date of retirement or subsequent reissuance, the treasury shares account is reduced by the weighted average cost of the common shares retired or reissued.
Comprehensive Income	Comprehensive Income Comprehensive income consists of net income and other comprehensive income (loss). Other comprehensive income (loss) includes unrealized gains and losses on securities available for sale, and changes in the funded status of the Company’s defined benefit pension plan, which are also recognized as separate components of equity.
Stock Based Compensation	Share-Based Compensation Compensation cost is recognized for restricted stock units and stock awards issued to employees and directors, respectively, based on the fair value of these awards at the date of grant. The market price of Park’s common shares at the date of grant is used to estimate the fair value of restricted stock units and stock awards. Compensation cost is recognized over the required service period, generally defined as the vesting period and is recorded in "Salaries" expense. (See Note 17-Share-Based Compensation.)
Loan Commitments and Related Financial Instruments	Loan Commitments and Related Financial Instruments Financial instruments include off‑balance sheet credit instruments, such as commitments to make loans and commercial letters of credit, issued to meet customer financing needs. The face amount for these items represents the exposure to loss, before considering customer collateral or ability to repay. Such financial instruments are recorded when they are funded.
Fair Value Measurement	Fair Value Measurement Fair values of financial instruments are estimated using relevant market information and other assumptions, as more fully disclosed in Note 25 - Fair Value. Fair value estimates involve uncertainties and matters of significant judgment regarding interest rates, credit risk, prepayments, and other factors, especially in the absence of broad markets for particular items. Changes in assumptions or in market conditions could significantly affect the estimates.
Transfers and Financial Assets	Transfers of Financial Assets Transfers of financial assets are accounted for as sales, when control over the assets has been relinquished. Control over transferred assets is deemed to be surrendered when the assets have been isolated from the Company, the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity.
Retirement Plans	Retirement Plans Pension expense is the net of service and interest cost, return on plan assets and amortization of gains and losses not immediately recognized. Employee KSOP plan expense is the amount of matching contributions to Park's employees stock ownership plan. Deferred compensation and supplemental retirement plan expense allocates the benefits over years of service. (See Note 18 - Benefit Plans.)
Earnings Per Common Share	Earnings Per Common Share Basic earnings per common share is net income available to common shareholders divided by the weighted average number of common shares outstanding during the period. Diluted earnings per common share includes the dilutive effect of additional potential common shares issuable under performance-based restricted stock unit awards, stock options, warrants and convertible securities. Earnings and dividends per common share are restated for any stock splits and stock dividends through the date of issuance of the consolidated financial statements. (See Note 17 - Share-Based Compensation and Note 21 - Earnings Per Common Share.)
Segment Reporting, Policy [Policy Text Block]	Operating Segments The Corporation is a financial holding company headquartered in Newark, Ohio. The operating segments for the Corporation are its chartered national bank subsidiary, PNB (headquartered in Newark, Ohio), SE Property Holdings, LLC ("SEPH"), and Guardian Financial Services Company ("GFSC").

Adoption of New Accounting Pr40

Adoption of New Accounting Pronouncements and Issued Not Yet Effective Accounting Standards Adoption of New Accounting Pronouncements (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements, Policy [Policy Text Block]	Adoption of New Accounting Pronouncements and Issued Not Yet Effective Accounting Standards The following is a summary of new accounting pronouncements, new laws impacting Park's consolidated financial statements, and issued not yet effective accounting standards: Adoption of New Accounting Pronouncements ASU 2016-09 - Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting: In March 2016, FASB issued ASU 2016-09 - Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting . This ASU provides simplification for several aspects of accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The new guidance is effective for annual reporting periods and interim reporting periods within those annual periods, beginning after December 15, 2016. Early adoption was permitted. The adoption of this guidance on January 1, 2017 did not have a material impact on Park's consolidated financial statements. ASU 2017-01 – Business Combinations (Topic 805): Clarifying the Definition of a Business: In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business . This ASU clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The new guidance is effective for annual reporting periods and interim reporting periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted. The early adoption of this guidance on October 1, 2017 did not have a material impact on Park's consolidated financial statements. Park will apply this guidance to all future transactions. ASU 2017-04 - Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment: In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. This ASU eliminates Step 2 from the goodwill impairment test. Instead, under the new guidance, an entity should perform its annual goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An impairment charge would be recognized for the amount by which the carrying amount exceeds the reporting unit's fair value. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The early adoption of this guidance with Park's April 1, 2017 annual goodwill impairment test did not have an impact on Park's consolidated financial statements. Issued Not Yet Effective Accounting Standards ASU 2014-09 - Revenue from Contracts with Customers (Topic 606): In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606). This ASU creates a new topic, Topic 606, to provide guidance on revenue recognition for entities that enter into contracts with customers to transfer goods or services or enter into contracts for the transfer of nonfinancial assets. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Additional disclosures are required to provide quantitative and qualitative information regarding the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. The adoption of this guidance on January 1, 2018 did not have a material impact on Park's consolidated financial statements. However, the adoption of this standard will result in additional disclosures beginning with the first quarter 2018 Form 10-Q. ASU 2016-01 - Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. In January 2016, the FASB issued ASU 2016-01 - Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. Changes to the current U.S. GAAP model primarily affect the accounting for equity investments, financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. In addition, this ASU clarifies guidance related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on AFS securities. The new guidance is effective for annual reporting periods and interim reporting periods within those annual periods, beginning after December 15, 2017. The adoption of this guidance on January 1, 2018 did not have a material impact on Park's consolidated financial statements, but will impact the fair value disclosures in Note 25 beginning with the first quarter 2018 Form 10-Q. ASU 2016-02 - Leases (Topic 842): In February 2016, the FASB issued ASU 2016-02 - Leases (Topic 842) . This ASU will require all organizations that lease assets to recognize on the balance sheet the assets and liabilities for the rights and obligations created by those leases. Additional qualitative and quantitative disclosures will be required so that users can understand more about the nature of an entity’s leasing activities. The new guidance is effective for annual reporting periods and interim reporting periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted. Management is currently analyzing data on leased assets. The adoption of this guidance is expected to increase both assets and liabilities, but is not expected to have a material impact on Park's consolidated statement of income. ASU 2016-13 - Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments: In June 2016, FASB issued ASU 2016-13 - Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . The new guidance replaces the incurred loss model with an expected loss model, which is referred to as the current expected credit loss ("CECL") model. The CECL model is applicable to the measurement of credit losses on financial assets measured at amortized cost, including loan receivables, HTM debt securities, and reinsurance receivables. It also applies to off-balance sheet credit exposures not accounted for as insurance (loan commitments, standby letters of credit, financial guarantees, and other similar instruments) and net investments in leases recognized by a lessor. The CECL model requires an entity to estimate credit losses over the life of an asset or off-balance sheet exposure. The new guidance is effective for annual reporting periods and interim reporting periods within those annual periods, beginning after December 15, 2019. Early adoption is permitted for annual reporting periods and interim reporting periods within those annual periods, beginning after December 15, 2018. Management is currently evaluating the impact of the adoption of this guidance on Park's consolidated financial statements. We anticipate that the adoption of the CECL model will result in a material increase to Park's allowance for loan losses. Management has established a committee to oversee the implementation of the CECL model and is currently in the process of implementing a software solution to assist in the adoption of this ASU. Management plans to run our current allowance model and a CECL model concurrently for 12 months prior to the adoption of this guidance on January 1, 2020. ASU 2016-15 - Statement of Cash Flows (Topic 203): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force): In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 203): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) . This ASU provides guidance on eight specific cash flow issues where current GAAP is either unclear or does not include specific guidance. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. As such transactions arise, management will utilize the updated guidance within Park’s consolidated statements of cash flows. ASU 2017-07 - Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost: In March 2017, the FASB issued ASU 2017-07 - Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. This ASU requires that an employer report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the income statement separately from the service cost component. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. The adoption of this guidance on January 1, 2018 did not have a material impact on Park's consolidated financial statements. ASU 2017-08 - Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities: In March 2017, the FASB issued ASU 2017-08 - Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities. This ASU amends the amortization period for certain purchased callable debt securities held at a premium. It shortens the amortization period for the premium to the earliest call date. Under current U.S. GAAP, premiums on callable debt securities generally are amortized to the maturity date. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted for interim or annual periods. The adoption of this guidance is not expected to have a material impact on Park's consolidated financial statements. ASU 2017-09 - Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting: In May 2017, the FASB issued ASU 2017-09 - Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting. This ASU amends the guidance concerning which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2017. The adoption of this guidance on January 1, 2018 did not impact Park's consolidated financial statements. ASU 2017-12 - Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities: In August 2017, the FASB issued ASU 2017-12 - Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. This ASU amends the current guidance with the objective of improving the financial reporting of hedging relationships to better portray the economic results of an entity's risk management activities in its financial statements. In addition, this ASU amends the current guidance to simplify the application of the hedge accounting guidance. The new guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted for interim or annual periods. The adoption of this guidance is not expected to have a material impact on Park's consolidated financial statements. Park is considering the early adoption of this guidance. ASU 2018-02 - Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income : In February 2018, the FASB issued ASU 2018-02 - Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. This ASU allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects, resulting from the newly - enacted federal corporate income tax rate. The amount of the reclassification is the difference between the historical federal corporate income tax rate and the newly - enacted 21% federal corporate income tax rate. The guidance is effective for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted for interim or annual periods. The early adoption of this guidance on January 1, 2018 resulted in a $3.8 million increase to Park's accumulated other comprehensive loss and a $3.8 million increase to retained earnings, which will be reflected in Park's first quarter 2018 Consolidated Balance Sheet.

Summary of Significant Accoun41

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of depreciable lives of premises and equipment	The range of depreciable lives over which premises and equipment are being depreciated are: Buildings 30 Years Equipment, furniture and fixtures 3 to 12 Years Leasehold improvements 1 to 10 Years

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of marketable securities	Investment securities at December 31, 2017 and December 31, 2016 were as follows: (In thousands) Amortized Cost Gross Unrealized/Unrecognized Holding Gains Gross Unrealized/Unrecognized Holding Losses Estimated Fair Value 2017: Securities Available-for-Sale Obligations of U.S. Treasury and other U.S. Government sponsored entities $ 245,000 $ — $ 2,280 $ 242,720 U.S. Government sponsored entities’ asset-backed securities 852,645 4,645 8,129 849,161 Other equity securities 675 1,260 — 1,935 Total $ 1,098,320 $ 5,905 $ 10,409 $ 1,093,816 2017: Securities Held-to-Maturity Obligations of states and political subdivisions $ 300,412 $ 6,575 $ 713 $ 306,274 U.S. Government sponsored entities’ asset-backed securities 56,785 758 38 57,505 Total $ 357,197 $ 7,333 $ 751 $ 363,779 (In thousands) Amortized Cost Gross Unrealized/Unrecognized Holding Gains Gross Unrealized/Unrecognized Holding Losses Estimated Fair Value 2016: Securities Available-for-Sale Obligations of U.S. Treasury and other U.S. Government sponsored entities $ 270,000 $ — $ 2,467 $ 267,533 U.S. Government sponsored entities’ asset-backed securities 991,642 5,372 9,842 987,172 Other equity securities 1,119 2,315 — 3,434 Total $ 1,262,761 $ 7,687 $ 12,309 $ 1,258,139 2016: Securities Held-to-Maturity Obligations of states and political subdivisions $ 188,622 $ 977 $ 5,148 $ 184,451 U.S. Government sponsored entities’ asset-backed securities 71,211 1,097 87 72,221 Total $ 259,833 $ 2,074 $ 5,235 $ 256,672
Schedule of unrealized loss on investments	The following table provides detail on investment securities with unrealized/unrecognized losses aggregated by investment category and length of time the individual securities had been in a continuous loss position at December 31, 2017 and December 31, 2016 : Less than 12 Months 12 Months or Longer Total (In thousands) Fair Value Unrealized/Unrecognized Losses Fair Value Unrealized/Unrecognized Losses Fair Value Unrealized/Unrecognized Losses 2017: Securities Available-for-Sale Obligations of U.S. Treasury and other U.S. Government sponsored entities $ 24,931 $ 70 $ 217,789 $ 2,210 $ 242,720 $ 2,280 U.S. Government sponsored entities' asset-backed securities 236,924 2,786 318,797 5,343 555,721 8,129 Total $ 261,855 $ 2,856 $ 536,586 $ 7,553 $ 798,441 $ 10,409 2017: Securities Held-to-Maturity Obligations of states and political subdivisions $ 26,644 $ 194 $ 45,498 $ 519 $ 72,142 $ 713 U.S. Government sponsored entities’ asset-backed securities 7,331 38 — — 7,331 38 Total $ 33,975 $ 232 $ 45,498 $ 519 $ 79,473 $ 751 Less than 12 Months 12 Months or Longer Total (In thousands) Fair Value Unrealized/Unrecognized Losses Fair Value Unrealized/Unrecognized Losses Fair Value Unrealized/Unrecognized Losses 2016: Securities Available-for-Sale Obligations of U.S. Treasury and other U.S. Government sponsored entities $ 247,695 $ 2,305 $ 19,838 $ 162 $ 267,533 $ 2,467 U.S. Government sponsored entities' asset-backed securities 612,321 9,473 27,325 369 639,646 9,842 Total $ 860,016 $ 11,778 $ 47,163 $ 531 $ 907,179 $ 12,309 2016: Securities Held-to-Maturity Obligations of states and political subdivisions $ 134,909 $ 5,148 $ — $ — $ 134,909 $ 5,148 U.S. Government sponsored entities' asset-backed securities $ — $ — $ 7,564 $ 87 $ 7,564 $ 87 Total $ 134,909 $ 5,148 $ 7,564 $ 87 $ 142,473 $ 5,235
Schedule of contractual maturity of debt securities	The amortized cost and estimated fair value of investments in debt securities at December 31, 2017 , are shown in the following table by contractual maturity, except for asset-backed securities, which are shown as a single total, due to the unpredictability of the timing in principal repayments. (In thousands) Amortized Cost Estimated Fair Value Tax Equivalent Yield (1) Securities Available-for-Sale U.S. Treasury and other U.S. Government sponsored entities’ notes: Due within one year $ 120,000 $ 119,499 1.14 % Due one through five years 125,000 123,221 1.29 % Total $ 245,000 $ 242,720 1.22 % U.S. Government sponsored entities’ asset-backed securities $ 852,645 $ 849,161 2.09 % Securities Held-to-Maturity Obligations of states and political subdivisions Due five through ten years $ 2,454 $ 2,462 3.61 % Due greater than ten years $ 297,958 $ 303,812 4.46 % Total $ 300,412 $ 306,274 4.46 % U.S. Government sponsored entities’ asset-backed securities $ 56,785 $ 57,505 3.16 %

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2017
Loans and Leases Receivable Disclosure [Abstract]
Schedule of composition of loan portfolio by class of loan	The composition of the loan portfolio, by class of loan, as of December 31, 2017 and December 31, 2016 was as follows: 12/31/2017 12/31/2016 (In thousands) Loan Balance Accrued Interest Receivable Recorded Investment Loan Balance Accrued Interest Receivable Recorded Investment Commercial, financial and agricultural * $ 1,053,453 $ 4,413 $ 1,057,866 $ 994,619 $ 3,558 $ 998,177 Commercial real estate * 1,167,607 4,283 1,171,890 1,155,703 4,161 1,159,864 Construction real estate: Commercial 125,389 401 125,790 135,343 398 135,741 Mortgage 52,203 133 52,336 48,699 106 48,805 Installment 3,878 13 3,891 4,903 17 4,920 Residential real estate: Commercial 393,094 1,029 394,123 406,687 940 407,627 Mortgage 1,110,426 1,516 1,111,942 1,169,495 1,459 1,170,954 HELOC 203,178 974 204,152 212,441 853 213,294 Installment 18,526 53 18,579 19,874 67 19,941 Consumer 1,241,736 3,808 1,245,544 1,120,850 3,385 1,124,235 Leases 2,993 36 3,029 3,243 29 3,272 Total loans $ 5,372,483 $ 16,659 $ 5,389,142 $ 5,271,857 $ 14,973 $ 5,286,830 * Included within commercial, financial and agricultural loans and commercial real estate loans is an immaterial amount of consumer loans that were not broken out by class.
Schedule of recorded investment in nonaccrual restructured and loans past due 90 days or more and accruing	The following table presents the recorded investment in nonaccrual loans, accruing troubled debt restructurings ("TDRs"), and loans past due 90 days or more and still accruing by class of loan as of December 31, 2017 and December 31, 2016 : 12/31/2017 (In thousands) Nonaccrual Loans Accruing TDRs Loans Past Due 90 Days or More and Accruing Total Nonperforming Loans Commercial, financial and agricultural $ 16,773 $ 1,291 $ — $ 18,064 Commercial real estate 12,979 5,163 — 18,142 Construction real estate: Commercial 986 338 — 1,324 Mortgage 8 92 — 100 Installment 52 — — 52 Residential real estate: Commercial 18,835 224 — 19,059 Mortgage 16,841 10,766 568 28,175 HELOC 1,593 1,025 14 2,632 Installment 586 616 7 1,209 Consumer 3,403 662 1,256 5,321 Total loans $ 72,056 $ 20,177 $ 1,845 $ 94,078 12/31/2016 (In thousands) Nonaccrual Loans Accruing TDRs Loans Past Due 90 Days or More and Accruing Total Nonperforming Loans Commercial, financial and agricultural $ 20,057 $ 600 $ 15 $ 20,672 Commercial real estate 19,169 5,305 — 24,474 Construction real estate: Commercial 1,833 393 — 2,226 Mortgage — 104 — 104 Installment 61 95 12 168 Residential real estate: Commercial 23,013 89 — 23,102 Mortgage 18,313 9,612 887 28,812 HELOC 1,783 673 25 2,481 Installment 644 609 60 1,313 Consumer 2,949 748 1,139 4,836 Total loans $ 87,822 $ 18,228 $ 2,138 $ 108,188
Schedule of loans individually evaluated for impairment and loans collectively evaluated for impairment	The following table provides additional information regarding those nonaccrual and accruing TDR loans that are individually evaluated for impairment and those collectively evaluated for impairment as of December 31, 2017 and December 31, 2016 . 12/31/2017 12/31/2016 (In thousands) Nonaccrual and accruing TDRs Loans individually evaluated for impairment Loans collectively evaluated for impairment Nonaccrual and accruing TDRs Loans individually evaluated for impairment Loans collectively evaluated for impairment Commercial, financial and agricultural $ 18,064 $ 18,039 $ 25 $ 20,657 $ 20,624 $ 33 Commercial real estate 18,142 18,142 — 24,474 24,474 — Construction real estate: Commercial 1,324 1,324 — 2,226 2,226 — Mortgage 100 — 100 104 — 104 Installment 52 — 52 156 — 156 Residential real estate: Commercial 19,059 19,059 — 23,102 23,102 — Mortgage 27,607 — 27,607 27,925 — 27,925 HELOC 2,618 — 2,618 2,456 — 2,456 Installment 1,202 — 1,202 1,253 — 1,253 Consumer 4,065 — 4,065 3,697 — 3,697 Total loans $ 92,233 $ 56,564 $ 35,669 $ 106,050 $ 70,426 $ 35,624
Schedule of loans individually evaluated for impairment by class of loan	The following table presents loans individually evaluated for impairment by class of loan as of December 31, 2017 and December 31, 2016 . 12/31/2017 12/31/2016 (In thousands) Unpaid principal balance Recorded investment Allowance for loan losses allocated Unpaid principal balance Recorded investment Allowance for loan losses allocated With no related allowance recorded Commercial, financial and agricultural $ 19,899 $ 14,704 $ — $ 41,075 $ 19,965 $ — Commercial real estate 18,974 18,060 — 23,961 23,474 — Construction real estate: Commercial 2,788 1,324 — 3,662 2,226 — Residential real estate: Commercial 19,346 19,012 — 24,409 22,687 — With an allowance recorded Commercial, financial and agricultural 5,394 3,335 681 810 659 152 Commercial real estate 137 82 2 1,014 1,000 309 Construction real estate: Commercial — — — — — — Residential real estate: Commercial 47 47 1 427 415 87 Total $ 66,585 $ 56,564 $ 684 $ 95,358 $ 70,426 $ 548
Schedule of average recorded investment and interest income recognized on loans individually evaluated for impairment	The following tables present the average recorded investment and interest income recognized during the year subsequent to impairment on loans individually evaluated for impairment as of and for the years ended December 31, 2017 , 2016 , and 2015 : Year ended December 31, 2017 (In thousands) Recorded Investment as of December 31, 2017 Average recorded investment Interest income recognized Commercial, financial and agricultural $ 18,039 $ 23,154 $ 963 Commercial real estate 18,142 21,692 903 Construction real estate: Commercial 1,324 1,729 64 Residential real estate: Commercial 19,059 20,490 778 Consumer — 5 — Total $ 56,564 $ 67,070 $ 2,708 Year ended December 31, 2016 (In thousands) Recorded Investment as of December 31, 2016 Average recorded investment Interest income recognized Commercial, financial and agricultural $ 20,624 $ 26,821 $ 885 Commercial real estate 24,474 22,828 884 Construction real estate: Commercial 2,226 5,503 66 Residential real estate: Commercial 23,102 24,341 2,942 Consumer — 3 — Total $ 70,426 $ 79,496 $ 4,777 Year ended December 31, 2015 (In thousands) Recorded Investment as of December 31, 2015 Average recorded investment Interest income recognized Commercial, financial and agricultural $ 30,595 $ 20,179 $ 340 Commercial real estate 18,025 17,883 550 Construction real estate: Commercial 6,720 7,732 47 Residential real estate: Commercial 25,324 24,968 1,026 Consumer — — — Total $ 80,664 $ 70,762 $ 1,963
Schedule of aging of the recorded investment in past due loans	The following tables present the aging of the recorded investment in past due loans as of December 31, 2017 and December 31, 2016 by class of loan. 12/31/2017 (In thousands) Accruing loans past due 30-89 days Past due, nonaccrual loans and loans past due 90 days or more and accruing (1) Total past due Total current (2) Total recorded investment Commercial, financial and agricultural $ 145 $ 1,043 $ 1,188 $ 1,056,678 $ 1,057,866 Commercial real estate 856 2,360 3,216 1,168,674 1,171,890 Construction real estate: Commercial 29 — 29 125,761 125,790 Mortgage 256 — 256 52,080 52,336 Installment 54 19 73 3,818 3,891 Residential real estate: Commercial 16 1,586 1,602 392,521 394,123 Mortgage 11,515 9,232 20,747 1,091,195 1,111,942 HELOC 616 876 1,492 202,660 204,152 Installment 239 253 492 18,087 18,579 Consumer 11,515 2,407 13,922 1,231,622 1,245,544 Leases — — — 3,029 3,029 Total loans $ 25,241 $ 17,776 $ 43,017 $ 5,346,125 $ 5,389,142 (1) Includes an aggregate of $1.8 million of loans past due 90 days or more and accruing. The remaining are past due, nonaccrual loans. (2) Includes an aggregate of $56.1 million of nonaccrual loans which are current in regards to contractual principal and interest payments. 12/31/2016 (In thousands) Accruing loans past due 30-89 days Past due, nonaccrual loans and loans past due 90 days or more and accruing (1) Total past due Total current (2) Total recorded investment Commercial, financial and agricultural $ 371 $ 4,113 $ 4,484 $ 993,693 $ 998,177 Commercial real estate 355 2,499 2,854 1,157,010 1,159,864 Construction real estate: Commercial — 541 541 135,200 135,741 Mortgage 559 — 559 48,246 48,805 Installment 223 64 287 4,633 4,920 Residential real estate: Commercial 330 3,631 3,961 403,666 407,627 Mortgage 10,854 9,769 20,623 1,150,331 1,170,954 HELOC 970 1,020 1,990 211,304 213,294 Installment 350 319 669 19,272 19,941 Consumer 12,579 2,094 14,673 1,109,562 1,124,235 Leases — — — 3,272 3,272 Total loans $ 26,591 $ 24,050 $ 50,641 $ 5,236,189 $ 5,286,830
Schedule of recorded investment by loan grade	The tables below present the recorded investment by loan grade at December 31, 2017 and December 31, 2016 for all commercial loans: 12/31/2017 (In thousands) 5 Rated 6 Rated Nonaccrual and Accruing Troubled Debt Restructurings Pass Rated Recorded Investment Commercial, financial and agricultural* $ 17,272 $ 153 $ 18,064 $ 1,022,377 $ 1,057,866 Commercial real estate* 5,322 457 18,142 1,147,969 1,171,890 Construction real estate: Commercial 278 — 1,324 124,188 125,790 Residential real estate: Commercial 216 1 19,059 374,847 394,123 Leases — — — 3,029 3,029 Total Commercial Loans $ 23,088 $ 611 $ 56,589 $ 2,672,410 $ 2,752,698 * Included within commercial, financial and agricultural loans and commercial real estate loans is an immaterial amount of consumer loans that were not broken out by class. 12/31/2016 (In thousands) 5 Rated 6 Rated Nonaccrual and Accruing Troubled Debt Restructurings Pass Rated Recorded Investment Commercial, financial and agricultural* $ 5,826 $ — $ 20,657 $ 971,694 $ 998,177 Commercial real estate* 7,548 190 24,474 1,127,652 1,159,864 Construction real estate: Commercial 287 118 2,226 133,110 135,741 Residential real estate: Commercial 1,055 124 23,102 383,346 407,627 Leases — — — 3,272 3,272 Total Commercial Loans $ 14,716 $ 432 $ 70,459 $ 2,619,074 $ 2,704,681
Schedule of troubled debt restructurings on financing receivables	The following table presents the recorded investment in financing receivables which were modified as TDRs within the previous 12 months and for which there was a payment default during the year ended December 31, 2017 , December 31, 2016 , and December 31, 2015. For this table, a loan is considered to be in default when it becomes 30 days contractually past due under the modified terms. The additional allowance for loan loss resulting from the defaults on TDR loans was immaterial. Year ended December 31, 2017 Year ended Year ended (In thousands) Number of Contracts Recorded Investment Number of Contracts Recorded Investment Number of Contracts Recorded Investment Commercial, financial and agricultural — $ — 7 $ 419 1 $ 1 Commercial real estate 2 82 5 843 1 626 Construction real estate: Commercial — — — — — — Mortgage — — — — — — Installment — — — — — — Residential real estate: Commercial 2 117 7 848 3 1,005 Mortgage 6 467 15 1,201 12 682 HELOC 4 194 — — 1 5 Installment — — 1 3 2 101 Consumer 50 375 62 484 47 434 Leases — — — — — — Total loans 64 $ 1,235 $ 97 $ 3,798 67 $ 2,854 The following tables detail the number of contracts modified as TDRs during the years ended December 31, 2017 , 2016 and 2015 as well as the recorded investment of these contracts at December 31, 2017 , 2016 , and 2015. The recorded investment pre- and post-modification is generally the same due to the fact that Park does not typically forgive principal. Year ended December 31, 2017 (In thousands) Number of Contracts Accruing Nonaccrual Recorded Investment Commercial, financial and agricultural 29 $ 945 $ 2,770 $ 3,715 Commercial real estate 9 1,050 313 1,363 Construction real estate: Commercial — — — — Mortgage 1 — 8 8 Installment — — — — Residential real estate: Commercial 15 144 486 630 Mortgage 33 888 1,359 2,247 HELOC 19 474 102 576 Installment 11 251 43 294 Consumer 309 171 1,121 1,292 Total loans 426 $ 3,923 $ 6,202 $ 10,125 Year ended December 31, 2016 (In thousands) Number of Contracts Accruing Nonaccrual Recorded Investment Commercial, financial and agricultural 32 $ 191 $ 8,450 $ 8,641 Commercial real estate 14 3,844 2,537 6,381 Construction real estate: Commercial 2 — 1,143 1,143 Mortgage — — — — Installment 1 — — — Residential real estate: Commercial 11 89 1,033 1,122 Mortgage 34 114 2,292 2,406 HELOC 13 104 178 282 Installment 5 102 3 105 Consumer 293 184 994 1,178 Total loans 405 $ 4,628 $ 16,630 $ 21,258 Year ended December 31, 2015 (In thousands) Number of Contracts Accruing Nonaccrual Recorded Investment Commercial, financial and agricultural 39 $ 8,948 $ 3,640 $ 12,588 Commercial real estate 14 637 3,523 4,160 Construction real estate: Commercial 2 513 — 513 Mortgage 1 19 — 19 Installment — — — — Residential real estate: Commercial 11 — 1,185 1,185 Mortgage 39 1,132 2,122 3,254 HELOC 26 315 45 360 Installment 9 — 155 155 Consumer 283 202 888 1,090 Total loans 424 $ 11,766 $ 11,558 $ 23,324

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Allowance For Loan Losses [Abstract]
Schedule of the activity in the allowance for loan losses	The activity in the allowance for loan losses for the years ended December 31, 2017 , 2016 , and 2015 is summarized in the following tables. Year ended December 31, 2017 (In thousands) Commercial, financial and agricultural Commercial real estate Construction real estate Residential real estate Consumer Leases Total Allowance for credit losses: Beginning balance $ 13,434 $ 10,432 $ 5,247 $ 10,958 $ 10,553 $ — $ 50,624 Charge-offs 6,017 1,798 105 1,208 10,275 — 19,403 Recoveries (809 ) (810 ) (2,124 ) (1,863 ) (4,603 ) (1 ) (10,210 ) Net charge-offs (recoveries) 5,208 988 (2,019 ) (655 ) 5,672 (1 ) 9,193 Provision (Recovery) 6,796 157 (2,836 ) (2,292 ) 6,733 (1 ) 8,557 Ending balance $ 15,022 $ 9,601 $ 4,430 $ 9,321 $ 11,614 — $ 49,988 Year ended December 31, 2016 (In thousands) Commercial, financial and agricultural Commercial real estate Construction real estate Residential real estate Consumer Leases Total Allowance for credit losses: Beginning balance $ 13,694 $ 9,197 $ 8,564 $ 13,514 $ 11,524 $ 1 $ 56,494 Charge-offs 5,786 412 1,436 3,014 10,151 — 20,799 Recoveries (1,259 ) (3,671 ) (8,559 ) (2,446 ) (4,094 ) (1 ) (20,030 ) Net charge-offs (recoveries) 4,527 (3,259 ) (7,123 ) 568 6,057 (1 ) 769 Provision (Recovery) 4,267 (2,024 ) (10,440 ) (1,988 ) 5,086 (2 ) (5,101 ) Ending balance $ 13,434 $ 10,432 $ 5,247 $ 10,958 $ 10,553 $ — $ 50,624 Year ended December 31, 2015 (In thousands) Commercial, financial and agricultural Commercial real estate Construction real estate Residential real estate Consumer Leases Total Allowance for credit losses: Beginning balance $ 10,719 $ 8,808 $ 8,652 $ 14,772 $ 11,401 $ — $ 54,352 Charge-offs 2,478 348 470 2,352 8,642 — 14,290 Recoveries (1,373 ) (2,241 ) (2,092 ) (2,438 ) (3,295 ) (3 ) (11,442 ) Net charge-offs (recoveries) 1,105 (1,893 ) (1,622 ) (86 ) 5,347 (3 ) 2,848 Provision (Recovery) 4,080 (1,504 ) (1,710 ) (1,344 ) 5,470 (2 ) 4,990 Ending balance $ 13,694 $ 9,197 $ 8,564 $ 13,514 $ 11,524 $ 1 $ 56,494
Schedule of the composition of the allowance for loan losses	The composition of the allowance for loan losses at December 31, 2017 and 2016 was as follows: December 31, 2017 (In thousands) Commercial, financial, and agricultural Commercial real estate Construction real estate Residential real estate Consumer Leases Total Allowance for loan losses: Ending allowance balance attributed to loans Individually evaluated for impairment $ 681 $ 2 $ — $ 1 $ — $ — $ 684 Collectively evaluated for impairment 14,341 9,599 4,430 9,320 11,614 — 49,304 Total ending allowance balance $ 15,022 $ 9,601 $ 4,430 $ 9,321 $ 11,614 $ — $ 49,988 Loan Balance: Loans individually evaluated for impairment $ 18,034 $ 18,131 $ 1,322 $ 19,058 $ — $ — $ 56,545 Loans collectively evaluated for impairment 1,035,419 1,149,476 180,148 1,706,166 1,241,736 2,993 5,315,938 Total ending loan balance $ 1,053,453 $ 1,167,607 $ 181,470 $ 1,725,224 $ 1,241,736 $ 2,993 $ 5,372,483 Allowance for loan losses as a percentage of loan balance: Loans individually evaluated for impairment 3.78 % 0.01 % — % 0.01 % — % — % 1.21 % Loans collectively evaluated for impairment 1.39 % 0.84 % 2.46 % 0.55 % 0.94 % — % 0.93 % Total 1.43 % 0.82 % 2.44 % 0.54 % 0.94 % — % 0.93 % Recorded Investment: Loans individually evaluated for impairment $ 18,039 $ 18,142 $ 1,324 $ 19,059 $ — $ — $ 56,564 Loans collectively evaluated for impairment 1,039,827 1,153,748 180,693 1,709,737 1,245,544 3,029 5,332,578 Total ending recorded investment $ 1,057,866 $ 1,171,890 $ 182,017 $ 1,728,796 $ 1,245,544 $ 3,029 $ 5,389,142 December 31, 2016 (In thousands) Commercial, financial, and agricultural Commercial real estate Construction real estate Residential real estate Consumer Leases Total Allowance for loan losses: Ending allowance balance attributed to loans Individually evaluated for impairment $ 152 $ 309 $ — $ 87 $ — $ — $ 548 Collectively evaluated for impairment 13,282 10,123 5,247 10,871 10,553 — 50,076 Total ending allowance balance $ 13,434 $ 10,432 $ 5,247 $ 10,958 $ 10,553 $ — $ 50,624 Loan Balance: Loans individually evaluated for impairment $ 20,622 $ 24,465 $ 2,226 $ 23,102 $ — $ — $ 70,415 Loans collectively evaluated for impairment 973,997 1,131,238 186,719 1,785,395 1,120,850 3,243 5,201,442 Total ending loan balance $ 994,619 $ 1,155,703 $ 188,945 $ 1,808,497 $ 1,120,850 $ 3,243 $ 5,271,857 Allowance for loan losses as a percentage of loan balance: Loans individually evaluated for impairment 0.74 % 1.26 % — % 0.38 % — % — % 0.78 % Loans collectively evaluated for impairment 1.36 % 0.89 % 2.81 % 0.61 % 0.94 % — % 0.96 % Total 1.35 % 0.90 % 2.78 % 0.61 % 0.94 % — % 0.96 % Recorded Investment: Loans individually evaluated for impairment $ 20,624 $ 24,474 $ 2,226 $ 23,102 $ — $ — $ 70,426 Loans collectively evaluated for impairment 977,553 1,135,390 187,240 1,788,714 1,124,235 3,272 5,216,404 Total ending recorded investment $ 998,177 $ 1,159,864 $ 189,466 $ 1,811,816 $ 1,124,235 $ 3,272 $ 5,286,830

Other Real Estate Owned Other45

Other Real Estate Owned Other Real Estate Owned (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule of Assets Repossessed or Foreclosed, or loans in process of foreclosure [Line Items]
Schedule of Assets Repossessed or Foreclosed, or loans in process of foreclosure [Table Text Block] [Text Block]	The carrying amount of foreclosed properties held at December 31, 2017 and December 31, 2016 are listed below, as well as the recorded investment of loans secured by residential real estate properties for which formal foreclosure proceedings were in process at those dates. (In thousands) December 31, 2017 December 31, 2016 OREO: Commercial real estate $ 7,888 $ 7,642 Construction real estate 4,852 4,624 Residential real estate 1,450 1,660 Total OREO $ 14,190 $ 13,926 Loans in process of foreclosure: Residential real estate $ 2,948 $ 3,250

Premises And Equipment (Tables)

Premises And Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Schedule of major categories of premises and equipment	The major categories of premises and equipment and accumulated depreciation are summarized as follows: December 31 (In thousands) 2017 2016 Land $ 19,603 $ 19,577 Buildings 77,711 75,472 Equipment, furniture and fixtures 55,799 52,719 Leasehold improvements 3,273 3,400 Total $ 156,386 $ 151,168 Less accumulated depreciation (100,485 ) (93,197 ) Premises and equipment, net $ 55,901 $ 57,971
Schedule of future minimum rental payments under operating leases	The Corporation leases certain premises and equipment accounted for as operating leases. The following is a schedule of the future minimum rental payments required for the next five years under such leases with initial terms in excess of one year: (In thousands) 2018 $ 1,726 2019 1,563 2020 865 2021 502 2022 446 Thereafter 307 Total $ 5,409

Investment in Qualified Affor47

Investment in Qualified Affordable Housing Investment in Qualified Affordable Housing (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Equity Method Investments [Table Text Block]	The table below details the balances of Park’s affordable housing tax credit investments and related unfunded commitments as of December 31, 2017 and 2016 . (In thousands) December 31, 2017 December 31, 2016 Affordable housing tax credit investments $ 49,669 $ 52,947 Unfunded commitments 14,282 14,282

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Schedule of summary of non-interest bearing and interest bearing deposits	At December 31, 2017 and 2016 , non-interest bearing and interest bearing deposits were as follows: December 31 (In thousands) 2017 2016 Non-interest bearing $ 1,633,941 $ 1,523,417 Interest bearing 4,183,385 3,998,539 Total $ 5,817,326 $ 5,521,956
Schedule of maturities of time deposits	At December 31, 2017 , the maturities of time deposits were as follows: (In thousands) 2018 $ 590,331 2019 217,286 2020 119,452 2021 51,958 2022 53,917 After 5 years 532 Total $ 1,033,476

Repurchase Agreement Borrowin49

Repurchase Agreement Borrowings Repurchase Agreement Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Transfers of Certain Financial Assets Accounted for as Secured Borrowings [Abstract]
Schedule of Assets and Associated Liabilities Accounted for as Secured Borrowings [Table Text Block]	The following table presents the carrying value of Park's repurchase agreements by remaining contractual maturity and collateral pledged at December 31, 2017 and December 31, 2016 : December 31, 2017 (In thousands) Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 days 30 - 90 days Greater than 90 days Total U.S. government and agency securities $ 182,185 $ — $ — $ 1,104 $ 183,289 December 31, 2016 (In thousands) Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 days 30 - 90 days Greater than 90 days Total U.S. government and agency securities $ 208,691 $ — $ — $ 301,104 $ 509,795

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Short-term Debt [Abstract]
Schedule of short-term debt	The outstanding balances for all short-term borrowings as of December 31, 2017 and 2016 and the weighted-average interest rates as of and paid during each of the years then ended were as follows: (In thousands) Repurchase agreements FHLB Advances 2017 Ending balance $ 183,289 $ 208,000 Highest month-end balance 230,905 208,000 Average daily balance 205,269 23,924 Weighted-average interest rate: As of year-end 0.41 % 1.64 % Paid during the year 0.35 % 1.16 % 2016 Ending balance $ 209,795 $ 185,000 Highest month-end balance 248,277 185,000 Average daily balance 224,763 15,694 Weighted-average interest rate: As of year-end 0.17 % 0.80 % Paid during the year 0.16 % 0.63 % Short-term borrowings were as follows: December 31 (In thousands) 2017 2016 Securities sold under agreements to repurchase $ 183,289 $ 209,795 FHLB advances 208,000 185,000 Total short-term borrowings $ 391,289 $ 394,795

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of maturities of long-term debt	Long-term debt is listed below: December 31, 2017 2016 (In thousands) Outstanding Balance Average Rate Outstanding Balance Average Rate Total Federal Home Loan Bank advances by year of maturity: 2017 $ — — % $ 50,000 1.25 % 2018 150,000 2.04 % 150,000 2.04 % 2019 100,000 1.92 % 75,000 1.96 % 2020 50,000 2.04 % 25,000 2.14 % 2021 100,000 1.96 % — — % 2022 — — % — — % Thereafter 100,000 3.40 % 100,000 3.40 % Total $ 500,000 2.27 % 400,000 2.27 % Total broker repurchase agreements by year of maturity: 2017 — — % 300,000 1.75 % Total $ — — % $ 300,000 1.75 % Total combined long-term debt by year of maturity: 2017 — — % 350,000 1.68 % 2018 150,000 2.04 % 150,000 2.04 % 2019 100,000 1.92 % 75,000 1.96 % 2020 50,000 2.04 % 25,000 2.14 % 2021 100,000 1.96 % — — % 2022 — — % — — % Thereafter 100,000 3.40 % 100,000 3.40 % Total $ 500,000 2.27 % $ 700,000 2.05 % Prepayment penalty — — (5,719 ) — Total long-term debt $ 500,000 2.27 % $ 694,281 2.07 %

Share-Based Compensation Change

Share-Based Compensation Changes in nonvested shares (Tables)	12 Months Ended
	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]	A summary of changes in the common shares subject to nonvested PBRSUs for the years ended December 31, 2017 and 2016 follows: Common shares subject to PBRSUs Nonvested at January 1, 2016 44,700 Granted 41,550 Vested — Forfeited (825 ) Nonvested at January 1, 2017 85,425 Granted 45,788 Vested (9,674 ) Forfeited (3,021 ) Adjustment for performance conditions of PBRSUs (1) (1,802 ) Nonvested at December 31, 2017 (2) 116,716

Share-Based Compensation Additi

Share-Based Compensation Additional share based compensation expense related to PBRSUs (Tables)	12 Months Ended
	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	The following table details expected additional share-based compensation expense related to PBRSUs currently outstanding: (In thousands) 2018 $ 2,446 2019 1,818 2020 822 2021 137 Total $ 5,223

Benefit Plans (Tables)

Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Defined Benefit Plan [Abstract]
Schedule of plan assets and benefit obligation activity	Using an accrual measurement date of December 31, 2017 and 2016 , plan assets and benefit obligation activity for the Pension Plan are listed below: (In thousands) 2017 2016 Change in fair value of plan assets Fair value at beginning of measurement period $ 167,047 $ 153,498 Actual return on plan assets 21,573 19,256 Employer contributions 15,000 — Benefits paid (7,885 ) (5,707 ) Fair value at end of measurement period $ 195,735 $ 167,047 Change in benefit obligation Projected benefit obligation at beginning of measurement period $ 114,455 $ 102,245 Service cost 5,270 5,055 Interest cost 5,085 4,869 Actuarial loss 21,773 7,993 Benefits paid (7,885 ) (5,707 ) Projected benefit obligation at the end of measurement period $ 138,698 $ 114,455 Funded status at end of year (fair value of plan assets less benefit obligation) $ 57,037 $ 52,592
Schedule of allocation of plan assets	The asset allocation for the Pension Plan as of each measurement date, by asset category, was as follows: Percentage of Plan Assets Asset category Target Allocation 2017 2016 Equity securities 50% - 100% 79 % 84 % Fixed income and cash equivalents remaining balance 21 % 16 % Total 100 % 100 %
Schedule of assumptions used to determine benefit obligations	The weighted average assumptions used to determine benefit obligations at December 31, 2017 , 2016 and 2015 were as follows: 2017 2016 2015 Discount rate 3.89 % 4.58 % 4.88 % Rate of compensation increase Under age 30 10.00 % 10.00 % 10.00 % Ages 30-39 6.00 % 6.00 % 6.00 % Ages 40-49 4.00 % 4.00 % 3.00 % Ages 50 and over 3.00 % 3.00 % 3.00 %
Schedule of estimated future pension benefit Payments	The estimated future pension benefit payments reflecting expected future service for the next ten years are shown below (in thousands): 2018 $ 8,274 2019 8,404 2020 9,320 2021 10,526 2022 10,937 2023-2027 53,456 Total $ 100,917
Schedule of balances of accumulated other comprehensive income loss	The following table shows ending balances of accumulated other comprehensive loss at December 31, 2017 and 2016 . (In thousands) 2017 2016 Prior service cost $ — $ — Net actuarial loss (33,799 ) (22,677 ) Total (33,799 ) (22,677 ) Deferred taxes 7,098 7,937 Disparate tax effect (1) 3,175 — Accumulated other comprehensive loss $ (23,526 ) $ (14,740 )
Schedule of components of net periodic benefit cost and other amounts recognized in other comprehensive income (loss)	Using an actuarial measurement date of December 31 for 2017 , 2016 and 2015 , components of net periodic benefit income and other amounts recognized in other comprehensive income were as follows: (In thousands) 2017 2016 2015 Components of net periodic benefit income and other amounts recognized in other comprehensive income Service cost $ (5,270 ) $ (5,055 ) $ (5,368 ) Interest cost (5,085 ) (4,869 ) (4,695 ) Expected return on plan assets 11,455 10,950 11,420 Amortization of prior service cost — — (15 ) Recognized net actuarial loss (576 ) (773 ) (637 ) Net periodic benefit income $ 524 $ 253 $ 705 Change to net actuarial (loss) gain for the period $ (11,698 ) $ 168 $ (1,400 ) Amortization of prior service cost — — 15 Amortization of net loss 576 773 637 Total recognized in other comprehensive income (11,122 ) 941 (748 ) Total recognized in net benefit income and other comprehensive income $ (10,598 ) $ 1,194 $ (43 )
Schedule of assumptions used to determine costs	The weighted average assumptions used to determine net periodic benefit income for the years ended December 31, 2017 , 2016 and 2015 are listed below: 2017 2016 2015 Discount Rate 4.58 % 4.88 % 4.42 % Rate of compensation increase Under age 30 10.00 % 10.00 % 10.00 % Ages 30-39 6.00 % 6.00 % 6.00 % Ages 40-49 4.00 % 3.00 % 3.00 % Ages 50 and over 3.00 % 3.00 % 3.00 % Expected long-term return on plan assets 7.00 % 7.25 % 7.25 %

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of deferred tax assets and liabilities	Significant components of the Corporation’s deferred tax assets and liabilities are as follows: December 31 (In thousands) 2017 2016 Deferred tax assets: Allowance for loan losses $ 10,498 $ 17,719 Accumulated other comprehensive loss – Pension plan 7,098 7,937 Accumulated other comprehensive loss – Unrealized losses on securities 946 1,618 Deferred compensation 2,744 4,140 OREO valuation adjustments 1,327 2,322 Net deferred loan fees 1,115 1,397 Deferred contract bonus 645 1,074 Nonvested equity-based compensation 1,069 1,115 Fixed assets 877 781 Accrued litigation 4 793 Other 1,226 2,525 Total deferred tax assets $ 27,549 $ 41,421 Deferred tax liabilities: Deferred investment income 6,120 10,199 Pension plan 19,076 26,344 Mortgage servicing rights 2,034 3,243 Partnership adjustments 460 549 Other 364 596 Total deferred tax liabilities $ 28,054 $ 40,931 Net deferred tax (liability) asset $ (505 ) $ 490
Federal and state income taxes	The components of the provision for federal income taxes are shown below: December 31, (In thousands) 2017 2016 2015 Currently payable Federal $ 20,660 $ 28,879 $ 26,153 Amortization of qualified affordable housing projects 10,278 7,300 6,664 Deferred Federal 3,289 581 (250 ) Total $ 34,227 $ 36,760 $ 32,567
Schedule of income tax rate reconciliation	The following is a reconciliation of income tax expense to the amount computed at the statutory rate of 35% for the years ended December 31, 2017 , 2016 and 2015 . 2017 2016 2015 Statutory federal corporate tax rate 35.0 % 35.0 % 35.0 % Changes in rates resulting from: Tax exempt interest income, net of disallowed interest (2.8 )% (1.3 )% (0.5 )% Bank owned life insurance (1.4 )% (1.2 )% (1.8 )% Investments in qualified affordable housing projects, net of tax benefits (1.9 )% (1.7 )% (1.9 )% Other tax credits — % — % (0.9 )% KSOP dividend deduction (1.0 )% (1.0 )% (1.0 )% Impact of the Tax Cuts and Jobs Act (1) 1.0 % — % — % Other — % 0.1 % (0.2 )% Effective tax rate 28.9 % 29.9 % 28.7 %
Reconciliation of unrecognized tax benefits	The following is a reconciliation of the beginning and ending amount of unrecognized tax benefits. (In thousands) 2017 2016 2015 January 1 Balance $ 633 $ 558 $ 532 Additions based on tax positions related to the current year 117 117 80 Additions for tax positions of prior years — 38 16 Reductions for tax positions of prior years (9 ) — — Reductions due to statute of limitations (77 ) (80 ) (70 ) December 31 Balance $ 664 $ 633 $ 558

Other Comprehensive Income (L56

Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2017
Other Comprehensive Income (Loss) [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Other comprehensive income (loss) components, net of income tax, are shown in the following table for the years ended December 31, 2017 , 2016 and 2015 . Year ended December 31, (in thousands) Changes in Pension Plan assets and benefit obligations Unrealized gains and losses on available-for-sale securities Total Beginning balance at January 1, 2017 $ (14,740 ) $ (3,005 ) $ (17,745 ) Other comprehensive (loss) gain before reclassifications (9,241 ) 1,261 (7,980 ) Amounts reclassified from accumulated other comprehensive loss 455 (1,184 ) (729 ) Net current period other comprehensive (loss) income (8,786 ) 77 (8,709 ) Ending balance at December 31, 2017 $ (23,526 ) $ (2,928 ) $ (26,454 ) Beginning balance at January 1, 2016 $ (15,351 ) $ (292 ) $ (15,643 ) Other comprehensive gain (loss) before reclassifications 109 (2,713 ) (2,604 ) Amounts reclassified from accumulated other comprehensive loss 502 — 502 Net current period other comprehensive income (loss) 611 (2,713 ) (2,102 ) Ending balance at December 31, 2016 $ (14,740 ) $ (3,005 ) $ (17,745 ) Beginning balance at January 1, 2015 $ (14,865 ) $ 1,257 $ (13,608 ) Other comprehensive loss before reclassifications (910 ) (1,549 ) (2,459 ) Amounts reclassified from accumulated other comprehensive loss 424 — 424 Net current period other comprehensive loss (486 ) (1,549 ) (2,035 ) Ending balance at December 31, 2015 $ (15,351 ) $ (292 ) $ (15,643 )
Schedule of components of other comprehensive income (loss)	The following table provides information concerning amounts reclassified out of accumulated other comprehensive loss for the years ended December 31, 2017 , 2016 and 2015 : Amount Reclassified from Accumulated Other Comprehensive Loss Affected Line Item in the Consolidated Statement of Income (In thousands) 2017 2016 2015 Amortization of defined benefit pension items Amortization of prior service cost $ — $ — $ 15 Employee benefits Amortization of net loss 576 773 637 Employee benefits Income before income taxes 576 773 652 Income before income taxes Federal income taxes 121 271 228 Federal income taxes Net of income tax $ 455 $ 502 $ 424 Net of income tax Unrealized gains & losses on available for sale securities Gain on sale of investment securities $ (1,821 ) $ — $ — Gain on sale of investment securities Other than temporary impairment — — — Miscellaneous expense Income before income taxes (1,821 ) — — Income before income taxes Federal income taxes (637 ) — — Federal income taxes Net of income tax $ (1,184 ) $ — $ — Net of income tax

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted earnings per common share	The following table sets forth the computation of basic and diluted earnings per common share: Year ended December 31 2017 2016 2015 Numerator: Net income $ 84,242 $ 86,135 $ 81,012 Denominator: Weighted-average common shares outstanding 15,295,573 15,332,553 15,364,281 Effect of dilutive PBRSUs 94,779 72,607 40,459 Weighted-average common shares outstanding adjusted for the effect of dilutive PBRSUs 15,390,352 15,405,160 15,404,740 Earnings per common share: Basic earnings per common share $ 5.51 $ 5.62 $ 5.27 Diluted earnings per common share $ 5.47 $ 5.59 $ 5.26

Financial Instruments With Of58

Financial Instruments With Off-Balance Sheet Risk And Financial Instruments With Concentrations Of Credit Risk (Tables)	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
Schedule of off-balance sheet financial instruments with credit risk	The total amounts of off-balance sheet financial instruments with credit risk were as follows: December 31 (In thousands) 2017 2016 Loan commitments $ 893,205 $ 912,007 Standby letters of credit 13,421 13,746

Loan Servicing (Tables)

Loan Servicing (Tables)	12 Months Ended
	Dec. 31, 2017
Transfers and Servicing of Financial Assets [Abstract]
Schedule of servicing assets at amortized value	Activity for MSRs and the related valuation allowance follows: December 31 (In thousands) 2017 2016 2015 MSRs: Carrying amount, net, beginning of year $ 9,266 $ 9,008 $ 8,613 Additions 1,941 2,286 1,748 Amortization (1,624 ) (1,835 ) (1,637 ) Change in valuation allowance 105 (193 ) 284 Carrying amount, net, end of year $ 9,688 $ 9,266 $ 9,008 Valuation allowance: Beginning of year $ 735 $ 542 $ 826 Change in valuation allowance (105 ) 193 (284 ) End of year $ 630 $ 735 $ 542

Fair Values (Tables)

Fair Values (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Schedule of financial assets and liabilities measured on a recurring basis	The following table presents assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements at December 31, 2017 using: (In thousands) Level 1 Level 2 Level 3 Balance at December 31, 2017 Assets Investment securities: Obligations of U.S. Treasury and other U.S. Government sponsored entities $ — $ 242,720 $ — $ 242,720 U.S. Government sponsored entities’ asset-backed securities — 849,161 — 849,161 Equity securities 1,518 — 417 1,935 Mortgage loans held for sale — 4,148 — 4,148 Mortgage IRLCs — 94 — 94 Liabilities Fair value swap $ — $ — $ 226 $ 226 Fair Value Measurements at December 31, 2016 using: (In thousands) Level 1 Level 2 Level 3 Balance at December 31, 2016 Assets Investment securities: Obligations of U.S. Treasury and other U.S. Government sponsored entities $ — $ 267,533 $ — $ 267,533 U.S. Government sponsored entities’ asset-backed securities — 987,172 — 987,172 Equity securities 2,644 — 790 3,434 Mortgage loans held for sale — 10,413 — 10,413 Mortgage IRLCs — 124 — 124 Liabilities Fair value swap $ — $ — $ 226 $ 226
Schedule of reconciliation of level 3 input for financial instruments measured on recurring basis	The table below is a reconciliation of the beginning and ending balances of the Level 3 inputs for the years ended December 31, 2017 and 2016 , for financial instruments measured on a recurring basis and classified as Level 3: Level 3 Fair Value Measurements (In thousands) Equity Securities Fair Value Swap Balance at January 1, 2017 $ 790 $ (226 ) Total Gains (Losses) Included in other comprehensive income 6 — Transfers out of Level 3 (1) (346 ) — Purchases, sales, issuances and settlements, other, net (33 ) — Balance at December 31, 2017 $ 417 $ (226 ) Balance at January 1, 2016 $ 769 $ (226 ) Total Gains (Losses) Included in other comprehensive income 21 — Balance at December 31, 2016 $ 790 $ (226 )
Schedule of assets and liabilities measured at fair value on a nonrecurring basis	Fair Value Measurements at December 31, 2017 Using: (In thousands) Level 1 Level 2 Level 3 Balance at December 31, 2017 Impaired Loans: Commercial real estate $ — $ — $ 2,735 $ 2,735 Construction real estate — — 127 127 Residential real estate — — 712 712 Total impaired loans recorded at fair value $ — $ — $ 3,574 $ 3,574 MSRs $ — $ 7,316 $ — $ 7,316 OREO: Commercial real estate — — 2,295 2,295 Construction real estate — — 3,204 3,204 Residential real estate — — 1,021 1,021 Total OREO recorded at fair value $ — $ — $ 6,520 $ 6,520 Fair Value Measurements at December 31, 2016 Using: (In thousands) Level 1 Level 2 Level 3 Balance at December 31, 2016 Impaired Loans: Commercial real estate $ — $ — $ 3,057 $ 3,057 Construction real estate — — 541 541 Residential real estate — — 2,385 2,385 Total impaired loans recorded at fair value $ — $ — $ 5,983 $ 5,983 MSRs $ — $ 6,769 $ — $ 6,769 OREO: Commercial real estate — — 2,644 2,644 Construction real estate — — 3,322 3,322 Residential real estate — — 931 931 Total OREO recorded at fair value $ — $ — $ 6,897 $ 6,897
Schedule of qualitative information about Level 3 fair value measurements for financial instruments measured at fair value on a non-recurring basis	The following tables present quantitative information about Level 3 fair value measurements for financial instruments measured at fair value on a non-recurring basis at December 31, 2017 and December 31, 2016 : December 31, 2017 (In thousands) Fair Value Valuation Technique Unobservable Input(s) Range (Weighted Average) Impaired loans: Commercial real estate $ 2,735 Sales comparison approach Adj to comparables 0.0% - 90.0% (22.7%) Income approach Capitalization rate 9.0% - 11.0% (9.9%) Cost approach Accumulated depreciation 90.1% (90.1%) Construction real estate $ 127 Sales comparison approach Adj to comparables 0.0% - 4.8% (2.4%) Residential real estate $ 712 Sales comparison approach Adj to comparables 0.3% - 33.0% (12.5%) Income approach Capitalization rate 10.5% (10.5%) Other real estate owned: Commercial real estate $ 2,295 Sales comparison approach Adj to comparables 0.9% - 68.4% (34.7%) Income approach Capitalization rate 13.0% (13.0%) Construction real estate $ 3,204 Sales comparison approach Adj to comparables 0.0% - 90.0% (24.5%) Bulk sale approach Discount rate 15.0% (15.0%) Residential real estate $ 1,021 Sales comparison approach Adj to comparables 1.2% - 79.7% (31.8%) December 31, 2016 (In thousands) Fair Value Valuation Technique Unobservable Input(s) Range (Weighted Average) Impaired loans: Commercial real estate $ 3,057 Sales comparison approach Adj to comparables 0.0% - 90.0% (20.2%) Income approach Capitalization rate 9.0% - 10.6% (10.1%) Cost approach Accumulated depreciation 17.0% - 18.0% (17.8%) Construction real estate $ 541 Sales comparison approach Adj to comparables 0.0% - 11.1% (1.6%) Bulk sale approach Discount rate 10.0% (10.0%) Residential real estate $ 2,385 Sales comparison approach Adj to comparables 0.3% - 110.0% (17.0%) Income approach Capitalization rate 10.0% (10.0%) Other real estate owned: Commercial real estate $ 2,644 Sales comparison approach Adj to comparables 0.0% - 68.4% (26.5%) Income approach Capitalization rate 13.0% - 14.0% (13.1%) Construction real estate $ 3,322 Sales comparison approach Adj to comparables 0.0% - 90.0% (24.7%) Bulk sale approach Discount rate 15.0% (15.0%) Residential real estate $ 931 Sales comparison approach Adj to comparables 3.2% - 79.7% (30.6%)
Fair value, by balance sheet grouping	The fair value of financial instruments at December 31, 2017 and December 31, 2016 , was as follows: December 31, 2017 Fair Value Measurements (In thousands) Carrying value Level 1 Level 2 Level 3 Total fair value Financial assets: Cash and money market instruments $ 169,112 $ 169,112 $ — $ — $ 169,112 Investment securities (1) 1,451,013 1,518 1,455,660 417 1,457,595 Accrued interest receivable - securities 5,505 — 5,505 — 5,505 Accrued interest receivable - loans 16,659 — — 16,659 16,659 Mortgage loans held for sale 4,148 — 4,148 — 4,148 Mortgage IRLCs 94 — 94 — 94 Impaired loans carried at fair value 3,574 — — 3,574 3,574 Other loans, net 5,314,679 — — 5,247,021 5,247,021 Loans receivable, net $ 5,322,495 $ — $ 4,242 $ 5,250,595 $ 5,254,837 Financial liabilities: Noninterest bearing checking accounts $ 1,633,941 $ 1,633,941 $ — $ — $ 1,633,941 Interest bearing transaction accounts 1,260,095 1,260,095 — — 1,260,095 Savings accounts 1,888,545 1,888,545 — — 1,888,545 Time deposits 1,033,476 — 1,035,093 — 1,035,093 Other 1,269 1,269 — — 1,269 Total deposits $ 5,817,326 $ 4,783,850 $ 1,035,093 $ — $ 5,818,943 Short-term borrowings $ 391,289 $ — $ 391,289 $ — $ 391,289 Long-term debt 500,000 — 504,503 — 504,503 Subordinated notes 15,000 — 13,370 — 13,370 Accrued interest payable – deposits 1,211 77 1,134 — 1,211 Accrued interest payable – debt/borrowings 1,067 11 1,056 — 1,067 Derivative financial instruments: Fair value swap $ 226 $ — $ — $ 226 $ 226 (1) Investment securities excludes the category "Other investment securities." This category consists of FHLB and FRB stock carried at their respective redemption values as it is not practical to calculate their fair values. Additional investments within "Other investment securities" are carried at their cost basis as these investments do not have a readily determinable fair value and Park does not have the ability to influence the operating or financial decisions of the investee. December 31, 2016 Fair Value Measurements (In thousands) Carrying value Level 1 Level 2 Level 3 Total fair value Financial assets: Cash and money market instruments $ 146,466 $ 146,466 $ — $ — $ 146,466 Investment securities (1) 1,517,972 2,644 1,511,377 790 1,514,811 Accrued interest receivable - securities 3,849 — 3,849 — 3,849 Accrued interest receivable - loans 14,973 — — 14,973 14,973 Loans held for sale 10,413 — 10,413 — 10,413 Mortgage IRLCs 124 — 124 — 124 Impaired loans carried at fair value 5,983 — — 5,983 5,983 Other loans, net 5,204,713 — — 5,161,919 5,161,919 Loans receivable, net $ 5,221,233 $ — $ 10,537 $ 5,167,902 $ 5,178,439 Financial liabilities: Noninterest bearing checking accounts $ 1,523,417 $ 1,523,417 $ — — $ 1,523,417 Interest bearing transaction accounts 1,174,448 1,174,448 — — 1,174,448 Savings accounts 1,704,920 1,704,920 — — 1,704,920 Time deposits 1,117,870 — 1,122,598 — 1,122,598 Other 1,301 1,301 — — 1,301 Total deposits $ 5,521,956 $ 4,404,086 $ 1,122,598 $ — $ 5,526,684 Short-term borrowings $ 394,795 $ — $ 394,795 $ — $ 394,795 Long-term debt 694,281 — 712,958 — 712,958 Subordinated notes 45,000 — 40,903 — 40,903 Accrued interest payable – deposits 900 82 818 — 900 Accrued interest payable – debt/borrowings 1,251 1 1,250 — 1,251 Derivative financial instruments: Fair value swap $ 226 $ — $ — $ 226 $ 226 (1) Investment securities excludes the category "Other investment securities." This category consists of FHLB and FRB stock carried at their respective redemption values as it is not practical to calculate their fair values. Additional investments within "Other investment securities" are carried at their cost basis as these investments do not have a readily determinable fair value and Park does not have the ability to influence the operating or financial decisions of the investee.
Impaired Financing Receivables [Table Text Block]	The table below provides additional detail on those impaired loans which are recorded at fair value as well as the remaining impaired loan portfolio not included above. The remaining impaired loans consist of loans which are not collateral dependent as well as loans carried at cost as the fair value of the underlying collateral or the present value of expected future cash flows on each of the loans exceeded the book value for each respective credit. December 31, 2017 (In thousands) Recorded Investment Prior Charge-Offs Specific Valuation Allowance Carrying Balance Impaired loans recorded at fair value $ 3,577 $ 2,780 $ 3 $ 3,574 Remaining impaired loans 52,987 7,260 681 52,306 Total impaired loans $ 56,564 $ 10,040 $ 684 $ 55,880 December 31, 2016 (In thousands) Recorded Investment Prior Charge-Offs Specific Valuation Allowance Carrying Balance Impaired loans recorded at fair value $ 6,379 $ 3,681 $ 396 $ 5,983 Remaining impaired loans 64,047 21,262 152 63,895 Total impaired loans $ 70,426 $ 24,943 $ 548 $ 69,878

Capital Ratios (Tables)

Capital Ratios (Tables)	12 Months Ended
	Dec. 31, 2017
Capital [Abstract]
Schedule of compliance with regulatory capital requirements under banking regulations	The following table indicates the capital ratios for PNB and Park at December 31, 2017 and 2016. As of December 31, 2017 Leverage Tier 1 Risk-Based Common Equity Tier 1 Total Risk-Based The Park National Bank 7.36 % 10.35 % 10.35 % 11.60 % Park National Corporation 9.44 % 13.22 % 12.94 % 14.14 % Adequately capitalized ratio 4.00 % 6.00 % 4.50 % 8.00 % Adequately capitalized ratio plus capital conservation buffer 4.00 % 8.50 % 7.00 % 10.50 % Well-capitalized ratio - PNB 5.00 % 8.00 % 6.50 % 10.00 % Well-capitalized ratio - Park N/A 6.00 % N/A 10.00 % As of December 31, 2016 Leverage Tier 1 Risk-Based Common Equity Tier 1 Total Risk-Based The Park National Bank 7.34 % 9.87 % 9.87 % 11.24 % Park National Corporation 9.56 % 12.83 % 12.55 % 14.32 % Adequately capitalized ratio 4.00 % 6.00 % 4.50 % 8.00 % Adequately capitalized ratio plus capital conservation buffer 4.00 % 8.50 % 7.00 % 10.50 % Well-capitalized ratio - PNB 5.00 % 8.00 % 6.50 % 10.00 % Well-capitalized ratio - Park N/A 6.00 % N/A 10.00 %
Schedule of various measures of capital ratio	The following table reflects various measures of capital for Park and PNB: To Be Adequately Capitalized To Be Well-Capitalized (In thousands) Actual Amount Ratio Amount Ratio Amount Ratio At December 31, 2017 Total Risk-Based Capital PNB $ 628,440 11.60 % $ 433,406 8.00 % $ 541,757 10.00 % Park 775,867 14.14 % 438,981 8.00 % 548,726 10.00 % Tier 1 Risk-Based Capital PNB $ 560,530 10.35 % $ 325,054 6.00 % $ 433,406 8.00 % Park 725,221 13.22 % 329,235 6.00 % 329,235 6.00 % Leverage Ratio PNB $ 560,530 7.36 % $ 304,722 4.00 % $ 380,903 5.00 % Park 725,221 9.44 % 307,441 4.00 % N/A N/A Common Equity Tier 1 PNB $ 560,530 10.35 % $ 243,791 4.50 % $ 352,142 6.50 % Park 710,221 12.94 % 246,927 4.50 % N/A N/A At December 31, 2016 Total Risk-Based Capital PNB $ 607,269 11.24 % $ 432,153 8.00 % $ 540,192 10.00 % Park 784,406 14.32 % 438,231 8.00 % 547,789 10.00 % Tier 1 Risk-Based Capital PNB $ 533,215 9.87 % $ 324,115 6.00 % $ 432,153 8.00 % Park 702,651 12.83 % 328,673 6.00 % 328,673 6.00 % Leverage Ratio PNB $ 533,215 7.34 % $ 290,671 4.00 % $ 363,339 5.00 % Park 702,651 9.56 % 293,916 4.00 % N/A N/A Common Equity Tier 1 PNB 533,215 9.87 % 243,086 4.50 % 351,125 6.50 % Park 687,651 12.55 % 246,505 4.50 % N/A N/A

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of operating results by Segment	Segment Information The Corporation is a financial holding company headquartered in Newark, Ohio. The operating segments for the Corporation are its chartered national bank subsidiary, PNB (headquartered in Newark, Ohio), SEPH and GFSC. GAAP requires management to disclose information about the different types of business activities in which a company engages and also information on the different economic environments in which a company operates, so that the users of the financial statements can better understand a company’s performance, better understand the potential for future cash flows, and make more informed judgments about the company as a whole. Park’s current operating segments are in line with GAAP as: (i) discrete financial information is available for each operating segment and (ii) the segments are aligned with internal reporting to Park’s Chief Executive Officer and President, who is the chief operating decision-maker. Operating results for the year ended December 31, 2017 (In thousands) PNB GFSC SEPH All Other Total Net interest income $ 235,243 $ 5,839 $ 2,089 $ 588 $ 243,759 Provision for (recovery of) loan losses 9,898 1,917 (3,258 ) — 8,557 Other income 77,126 40 404 3,065 80,635 Other expense 180,275 3,036 5,252 8,805 197,368 Income (loss) before taxes 122,196 926 499 (5,152 ) 118,469 Income taxes (benefit) 34,881 666 1,375 (2,695 ) 34,227 Net income (loss) $ 87,315 $ 260 $ (876 ) $ (2,457 ) $ 84,242 Balances at December 31, 2017 Assets $ 7,467,851 $ 32,077 $ 24,902 $ 12,790 $ 7,537,620 Loans 5,339,255 33,385 10,891 (11,048 ) 5,372,483 Deposits 5,896,676 3,449 — (82,799 ) 5,817,326 Operating results for the year ended December 31, 2016 (In thousands) PNB GFSC SEPH All Other Total Net interest income (loss) $ 227,576 $ 5,874 $ 4,774 $ (138 ) $ 238,086 Provision for (recovery of) loan losses 2,611 1,887 (9,599 ) — (5,101 ) Other income (loss) 74,803 (1 ) 2,974 955 78,731 Other expense 177,562 4,457 7,273 9,731 199,023 Income (loss) before taxes 122,206 (471 ) 10,074 (8,914 ) 122,895 Income taxes (benefit) 37,755 (164 ) 3,526 (4,357 ) 36,760 Net income (loss) $ 84,451 $ (307 ) $ 6,548 $ (4,557 ) $ 86,135 Balances at December 31, 2016 Assets $ 7,389,538 $ 32,268 $ 25,342 $ 20,438 $ 7,467,586 Loans 5,234,828 32,661 12,354 (7,986 ) 5,271,857 Deposits 5,630,199 3,809 — (112,052 ) 5,521,956 Operating results for the year ended December 31, 2015 (In thousands) PNB GFSC SEPH All Other Total Net interest income (loss) $ 220,879 $ 6,588 $ (74 ) $ 239 $ 227,632 Provision for (recovery of) loan losses 7,665 1,415 (4,090 ) — 4,990 Other income 75,188 2 1,848 513 77,551 Other expense 167,476 2,984 6,182 9,972 186,614 Income (loss) before taxes 120,926 2,191 (318 ) (9,220 ) 113,579 Income taxes (benefit) 36,581 768 (111 ) (4,671 ) 32,567 Net income (loss) $ 84,345 $ 1,423 $ (207 ) $ (4,549 ) $ 81,012 Balances at December 31, 2015 Assets $ 7,229,764 $ 35,793 $ 33,541 $ 12,256 $ 7,311,354 Loans 5,029,072 35,469 15,153 (11,609 ) 5,068,085 Deposits 5,447,293 4,627 — (104,278 ) 5,347,642
Schedule of reconciliation of financial information for the reportable segments to the Corporation’s consolidated totals	The following is a reconciliation of financial information for the reportable segments to the Corporation’s consolidated totals: 2017 (In thousands) Net Interest Income Depreciation Expense Other Expense Income Taxes Assets Deposits Totals for reportable segments $ 243,171 $ 8,644 $ 179,919 $ 36,922 $ 7,524,830 $ 5,900,125 Elimination of intersegment items 1,500 — — — (14,679 ) (82,799 ) Parent Co. totals - not eliminated (912 ) — 8,805 (2,695 ) 27,469 — Totals $ 243,759 $ 8,644 $ 188,724 $ 34,227 $ 7,537,620 $ 5,817,326 2016 (In thousands) Net Interest Income Depreciation Expense Other Expense Income Taxes Assets Deposits Totals for reportable segments $ 238,224 $ 8,396 $ 180,896 $ 41,117 $ 7,447,148 $ 5,634,008 Elimination of intersegment items 2,164 — — — (9,204 ) (112,052 ) Parent Co. totals - not eliminated (2,302 ) — 9,731 (4,357 ) 29,642 — Totals $ 238,086 $ 8,396 $ 190,627 $ 36,760 $ 7,467,586 $ 5,521,956 2015 (In thousands) Net Interest Income Depreciation Expense Other Expense Income Taxes Assets Deposits Totals for reportable segments $ 227,393 $ 7,347 $ 169,295 $ 37,238 $ 7,299,098 $ 5,451,920 Elimination of intersegment items 2,561 — — — (13,557 ) (104,278 ) Parent Co. totals - not eliminated (2,322 ) — 9,972 (4,671 ) 25,813 — Totals $ 227,632 $ 7,347 $ 179,267 $ 32,567 $ 7,311,354 $ 5,347,642

Parent Company Statements (Tabl

Parent Company Statements (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Balance Sheets	Condensed Balance Sheets December 31, 2017 and 2016 (In thousands) 2017 2016 Assets: Cash $ 79,452 $ 112,067 Investment in subsidiaries 645,287 626,569 Debentures receivable from PNB 25,000 25,000 Other investments 1,398 2,962 Other assets 26,838 26,651 Total assets $ 777,975 $ 793,249 Liabilities: Subordinated notes 15,000 45,000 Other liabilities 6,874 6,009 Total liabilities 21,874 51,009 Total shareholders’ equity 756,101 742,240 Total liabilities and shareholders’ equity $ 777,975 $ 793,249
Statements of Income	Condensed Statements of Income for the years ended December 31, 2017, 2016 and 2015 (In thousands) 2017 2016 2015 Income: Dividends from subsidiaries $ 60,000 $ 60,000 $ 60,000 Interest and dividends 1,500 2,164 2,561 Gain on sale of investment securities 1,821 — — Other 1,405 1,081 560 Total income 64,726 63,245 63,121 Expense: Interest expense 1,073 2,429 2,369 Other, net 8,805 9,730 9,972 Total expense 9,878 12,159 12,341 Income before federal taxes and equity in undistributed income of subsidiaries 54,848 51,086 50,780 Federal income tax benefit 2,695 4,357 4,671 Income before equity in undistributed income of subsidiaries 57,543 55,443 55,451 Equity in undistributed income of subsidiaries 26,699 30,692 25,561 Net income $ 84,242 $ 86,135 $ 81,012 Other comprehensive loss (1) (8,709 ) (2,102 ) (2,035 ) Comprehensive income 75,533 84,033 78,977
Statements of Cash Flows	Statements of Cash Flows for the years ended December 31, 2017, 2016 and 2015 (In thousands) 2017 2016 2015 Operating activities: Net income $ 84,242 $ 86,135 $ 81,012 Adjustments to reconcile net income to net cash provided by operating activities: Undistributed income of subsidiaries (26,699 ) (30,692 ) (25,561 ) Compensation expense for issuance of treasury stock to directors 1,241 950 963 Share-based compensation expense 2,701 1,864 865 Realized net investment security gains (1,821 ) — — Decrease (increase) in other assets 205 (3,425 ) (182 ) Increase (decrease) in other liabilities 475 (2,524 ) 485 Net cash provided by operating activities 60,344 52,308 57,582 Investing activities: Proceeds from sales of securities 2,265 — — Repayment of investments in and advances to subsidiaries — 15,000 10,000 Net cash provided by investing activities 2,265 15,000 10,000 Financing activities: Cash dividends paid (57,493 ) (57,653 ) (57,776 ) Repayment of subordinated notes (30,000 ) — — Repurchase of treasury shares (7,378 ) — (6,058 ) Cash payment for fractional shares (6 ) (4 ) (3 ) Value of common shares withheld to pay employee income taxes (347 ) — — Net cash used in financing activities (95,224 ) (57,657 ) (63,837 ) (Decrease) increase in cash (32,615 ) 9,651 3,745 Cash at beginning of year 112,067 102,416 98,671 Cash at end of year $ 79,452 $ 112,067 $ 102,416

Summary of Significant Accoun64

Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Line Items]
Other Repossessed Assets	$ 5,500	$ 600
Goodwill	72,334	72,334
Average required reserve balance	$ 64,800	$ 51,600
Historical loss period used in estimating loan loss reserve	96 months	84 months
Reserve coverage period in historical losses	1 year 11 months 2 days	1 year 11 months 12 days
Compensating Balance, Amount	$ 0
Commercial Loan
Accounting Policies [Line Items]
Reserve coverage period in historical losses	3 years 2 months 28 days	3 years 2 months 13 days
Consumer
Accounting Policies [Line Items]
Financing Receivable, Allowance for Credit Losses, Factors that Influenced Management's Judgment	0.0034
Commercial Portfolio Segment [Member]
Accounting Policies [Line Items]
Financing Receivable, Allowance for Credit Losses, Factors that Influenced Management's Judgment	0.0037	0.0039

Summary of Significant Accoun65

Summary of Significant Accounting Policies - Depreciable Lives of Premises and Equipment (Details)	12 Months Ended
	Dec. 31, 2017
Minimum | Buildings
Property, Plant and Equipment [Line Items]
Premises and equipment, depreciable lives	30 years
Minimum | Equipment, furniture and fixtures
Property, Plant and Equipment [Line Items]
Premises and equipment, depreciable lives	3 years
Minimum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, depreciable lives	1 year
Maximum | Buildings
Property, Plant and Equipment [Line Items]
Premises and equipment, depreciable lives	30 years
Maximum | Equipment, furniture and fixtures
Property, Plant and Equipment [Line Items]
Premises and equipment, depreciable lives	12 years
Maximum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, depreciable lives	10 years

Adoption of New Accounting Pr66

Adoption of New Accounting Pronouncements and Issued Not Yet Effective Accounting Standards (Details) $ in Thousands	Dec. 31, 2018USD ($)
Subsequent Event [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 3,800

Investment Securities - Narrat

Investment Securities - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Investments [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%	35.00%	35.00%
Tax Equivalent Interest Adjustment	$ 3,900,000
Other than Temporary Impairment Losses, Investments	0	$ 0	$ 0
Amortized cost of securities available-for-sale	1,098,320,000	1,262,761,000
Available-for-sale Securities, Gross Realized Gains	1,821,000
Securities held-to-maturity, at amortized cost (fair value of $363,779 and $256,672 at December 31, 2017 and 2016, respectively)	357,197,000	259,833,000
Federal home loan bank stock	50,100,000	50,086,000
Federal reserve bank stock	$ 8,200,000	8,226,000
Investment Securities average remaining life	4 years 4 months 17 days
Money pledged for government and trust department deposits	$ 317,000,000	343,000,000
Money pledged to secure repurchase agreements	215,000,000	569,000,000
Money Pledged as Collateral for FHLB Advance Borrowings	$ 25,000,000	25,000,000
Schedule of Repurchase Agreement Counterparties with Whom Repurchase Agreements Exceed 10 Percent of Stockholders' Equity [Table Text Block]	0
Percentage of amount greater than shareholder's equity	10.00%
Held-to-maturity Securities, Sold Security, Realized Gain (Loss)			$ 88,000
percent of held to securities sold paid down			97.80%
Equity investments	$ 3,500,000	3,500,000
Securities sold at a gain [Member]
Schedule of Investments [Line Items]
Amortized cost of securities available-for-sale	$ 444,000	0
Securities held-to-maturity, at amortized cost (fair value of $363,779 and $256,672 at December 31, 2017 and 2016, respectively)			$ 3,056,000
U.S. Government sponsored entity asset-backed securities
Schedule of Investments [Line Items]
Asset-backed securities mortgage portfolio, maturity term	15 years
Amortized cost of securities available-for-sale	$ 852,645,000	991,642,000
Securities held-to-maturity, at amortized cost (fair value of $363,779 and $256,672 at December 31, 2017 and 2016, respectively)	56,785,000	$ 71,211,000
Residential mortgage-backed securities
Schedule of Investments [Line Items]
Amortized cost of securities available-for-sale	455,300,000
Securities held-to-maturity, at amortized cost (fair value of $363,779 and $256,672 at December 31, 2017 and 2016, respectively)	0
Collateralized mortgage-backed securities
Schedule of Investments [Line Items]
Amortized cost of securities available-for-sale	397,300,000
Securities held-to-maturity, at amortized cost (fair value of $363,779 and $256,672 at December 31, 2017 and 2016, respectively)	$ 56,800,000
Minimum | U.S. Treasury and sponsored entities callable notes
Schedule of Investments [Line Items]
Available for Sale Securities, Debt Maturities, Term	3 months
Maximum | U.S. Treasury and sponsored entities callable notes
Schedule of Investments [Line Items]
Available for Sale Securities, Debt Maturities, Term	2 years 6 months

Investment Securities - Schedu

Investment Securities - Schedule of Investment Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Securities Available-for-Sale
Amortized Cost	$ 1,098,320	$ 1,262,761
Gross Unrealized/Unrecognized Holding Gains	5,905	7,687
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	10,409	12,309
Estimated Fair Value	1,093,816	1,258,139
Securities Held-to-Maturity
Securities held-to-maturity, at amortized cost (fair value of $363,779 and $256,672 at December 31, 2017 and 2016, respectively)	357,197	259,833
Gross Unrealized/Unrecognized Holding Gains	7,333	2,074
Gross Unrealized/Unrecognized Holding Losses	751	5,235
Estimated Fair Value	363,779	256,672
Obligations of U.S. Treasury and other U.S. Government sponsored entities
Securities Available-for-Sale
Amortized Cost	245,000	270,000
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	2,280	2,467
Estimated Fair Value	242,720	267,533
Obligations of States and Political Subdivisions
Securities Held-to-Maturity
Securities held-to-maturity, at amortized cost (fair value of $363,779 and $256,672 at December 31, 2017 and 2016, respectively)	300,412	188,622
Gross Unrealized/Unrecognized Holding Gains	6,575	977
Gross Unrealized/Unrecognized Holding Losses	713	5,148
Estimated Fair Value	306,274	184,451
U.S. Government sponsored entity asset-backed securities
Securities Available-for-Sale
Amortized Cost	852,645	991,642
Gross Unrealized/Unrecognized Holding Gains	4,645	5,372
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	8,129	9,842
Estimated Fair Value	849,161	987,172
Securities Held-to-Maturity
Securities held-to-maturity, at amortized cost (fair value of $363,779 and $256,672 at December 31, 2017 and 2016, respectively)	56,785	71,211
Gross Unrealized/Unrecognized Holding Gains	758	1,097
Gross Unrealized/Unrecognized Holding Losses	38	87
Estimated Fair Value	57,505	72,221
Equity securities
Securities Available-for-Sale
Amortized Cost	675	1,119
Gross Unrealized/Unrecognized Holding Gains	1,260	2,315
Estimated Fair Value	$ 1,935	$ 3,434

Investment Securities - Sche69

Investment Securities - Schedule of Unrealized Loss on Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 Months	$ 261,855	$ 860,016
12 Months or Longer	536,586	47,163
Total	798,441	907,179
Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months	2,856	11,778
12 Months or Longer	7,553	531
Total	10,409	12,309
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 Months	33,975	134,909
12 Months or Longer	45,498	7,564
Total	79,473	142,473
Held-to-maturity Securities, Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months	232	5,148
12 Months or Longer	519	87
Total	751	5,235
Obligations of U.S. Treasury and other U.S. Government sponsored entities
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 Months	24,931	247,695
12 Months or Longer	217,789	19,838
Total	242,720	267,533
Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months	70	2,305
12 Months or Longer	2,210	162
Total	2,280	2,467
U.S. Government sponsored entity asset-backed securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 Months	236,924	612,321
12 Months or Longer	318,797	27,325
Total	555,721	639,646
Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months	2,786	9,473
12 Months or Longer	5,343	369
Total	8,129	9,842
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 Months	7,331
12 Months or Longer		7,564
Total	7,331	7,564
Held-to-maturity Securities, Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months	38
12 Months or Longer		87
Total	38	87
Obligations of States and Political Subdivisions
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 Months	26,644	134,909
12 Months or Longer	45,498
Total	72,142	134,909
Held-to-maturity Securities, Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months	194	5,148
12 Months or Longer	519
Total	$ 713	$ 5,148

Investment Securities - Amorti

Investment Securities - Amortized Cost and Estimated Fair Value of Investments in Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Available-for-sale Securities, Debt Maturities, Estimated Fair Value [Abstract]
Estimated Fair Value	$ 1,093,816	$ 1,258,139
Held-to-maturity Securities, Debt Maturities, Amortized Cost [Abstract]
U.S. Government sponsored entities’ asset-backed securities	357,197	259,833
Fair value of securities held-to-maturity	363,779	256,672
Obligations of U.S. Treasury and other U.S. Government sponsored entities
Schedule of Investments [Line Items]
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	120,000
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	$ 119,499
Available for Sale Securities Debt Maturities next twelve months Weighted Avg Yield	1.14%
Available-for-sale Securities, Debt Maturities, Amortized Cost [Abstract]
Due one through five years	$ 125,000
Total	245,000
Available-for-sale Securities, Debt Maturities, Estimated Fair Value [Abstract]
Due one through five years	123,221
Estimated Fair Value	$ 242,720	267,533
Available for Sale Securities Weighted Avg Yield	1.22%
Available for Sale Securities Debt Maturities After One Through Five Years Weighted Avg Yield	1.29%
Obligations of States and Political Subdivisions
Available-for-sale Securities, Debt Maturities, Estimated Fair Value [Abstract]
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	$ 2,454
Held-to-maturity Securities, Debt Maturities, Year Six Through Ten, Fair Value	$ 2,462
held to maturity securities weighted avg yield yrs 5-10	3.61%
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount	$ 297,958
Held-to-maturity Securities, Debt Maturities, after Ten Years, Fair Value	303,812
Held-to-maturity Securities, Debt Maturities, Amortized Cost [Abstract]
U.S. Government sponsored entities’ asset-backed securities	300,412	188,622
Fair value of securities held-to-maturity	$ 306,274	184,451
Held-to-maturity Securities, Debt Maturities, Estimated Fair Value [Abstract]
Held to Maturity Securities weighted avg yield	4.46%
U.S. Government sponsored entity asset-backed securities
Available-for-sale Securities, Debt Maturities, Amortized Cost [Abstract]
Total	$ 852,645
Available-for-sale Securities, Debt Maturities, Estimated Fair Value [Abstract]
Estimated Fair Value	$ 849,161	987,172
Available for Sale Securities Weighted Avg Yield	2.09%
Held-to-maturity Securities, Debt Maturities, Amortized Cost [Abstract]
U.S. Government sponsored entities’ asset-backed securities	$ 56,785	71,211
Fair value of securities held-to-maturity	$ 57,505	$ 72,221
Held-to-maturity Securities, Debt Maturities, Estimated Fair Value [Abstract]
Held to Maturity Securities weighted avg yield	3.16%

Loans - Narrative (Details)

Loans - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	$ 1,235,000	$ 3,798,000	$ 2,854,000
Loans and Leases Receivable, Deferred Income	12,200,000	11,100,000
Deposit Liabilities Reclassified as Loans Receivable	1,900,000	2,900,000
Troubled Debt Restructuring, Classification removed	500,000	2,700,000
Partial charge-offs on impaired loans	10,040,000	24,943,000
Allowance for loans individually evaluated for impairment	684,000	548,000
Recorded investment, related to loans	3,500,000	2,100,000
Loans 90 days past due and still accruing	1,845,000	2,138,000
financing receivable non accrual current	56,100,000	65,900,000
TDRs included in nonaccrual loan totals	38,500,000	46,900,000
Nonaccrual TDRs considered current	32,400,000	38,000,000
TDRs included in accruing loan totals	20,200,000	18,200,000
Loans and Leases Receivable, Impaired, Commitment to Lend	1,300,000	700,000
Specific reserves related to troubled debt restructuring	500,000	200,000
Additional specific reserves related to troubled debt restructuring	300,000	1,000,000	1,300,000
Modified substandard commercial loans, total recorded investment	106,000	26,000
Modified substandard consumer loans total recorded investment	8,900,000	7,400,000
Nonaccrual loans not classified as TDRs at prior fiscal year end	1,800,000	9,400,000	800,000
Consumer
Financing Receivable, Recorded Investment [Line Items]
Allowance for loans individually evaluated for impairment	0	0
Loans 90 days past due and still accruing	1,256,000	1,139,000
Executive officers and directors
Financing Receivable, Recorded Investment [Line Items]
Loans due from related party	42,100,000	43,400,000
New loan made to related party	1,600,000	5,400,000
Repayment of loans due from related party	11,400,000	15,300,000
Increase (Decrease) in Customer Advances	11,400,000	3,500,000
Accruing
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	180,000	111,000	44,000
Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	1,100,000	3,700,000	$ 2,800,000
Financing Receivable With No Related Allowance Recorded [Member]
Financing Receivable, Recorded Investment [Line Items]
Partial charge-offs on impaired loans	7,900,000	24,700,000
Financing Receivable With Related Allowance Recorded [Member]
Financing Receivable, Recorded Investment [Line Items]
Partial charge-offs on impaired loans	2,100,000	200,000
Loans receivable | Executive officers and directors
Financing Receivable, Recorded Investment [Line Items]
Loans due from related party	$ 31,100,000	$ 29,600,000

Loans - Composition of Loan Po

Loans - Composition of Loan Portfolio By Class of Loan (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance		$ 66,585	$ 95,358
Impaired Financing Receivable, Recorded Investment		56,564	70,426	$ 80,664
Impaired Financing Receivable, Related Allowance		684	548
Loan Balance		5,372,483	5,271,857
Accrued Interest Receivable		16,659	14,973
Recorded Investment		5,389,142	5,286,830
Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment		18,039	20,624	30,595
Loan Balance	[1]	1,053,453	994,619
Accrued Interest Receivable	[1]	4,413	3,558
Recorded Investment	[1]	1,057,866	998,177
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment		18,142	24,474	18,025
Loan Balance	[1]	1,167,607	1,155,703
Accrued Interest Receivable	[1]	4,283	4,161
Recorded Investment	[1]	1,171,890	1,159,864
Construction real estate
Financing Receivable, Recorded Investment [Line Items]
Loan Balance		181,470	188,945
Recorded Investment		182,017	189,466
Commercial
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment		1,324	2,226	6,720
Loan Balance		125,389	135,343
Accrued Interest Receivable		401	398
Recorded Investment		125,790	135,741
Mortgage
Financing Receivable, Recorded Investment [Line Items]
Loan Balance		52,203	48,699
Accrued Interest Receivable		133	106
Recorded Investment		52,336	48,805
Installment
Financing Receivable, Recorded Investment [Line Items]
Loan Balance		3,878	4,903
Accrued Interest Receivable		13	17
Recorded Investment		3,891	4,920
Commercial
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment		19,059	23,102	$ 25,324
Loan Balance		393,094	406,687
Accrued Interest Receivable		1,029	940
Recorded Investment		394,123	407,627
Mortgage
Financing Receivable, Recorded Investment [Line Items]
Loan Balance		1,110,426	1,169,495
Accrued Interest Receivable		1,516	1,459
Recorded Investment		1,111,942	1,170,954
HELOC
Financing Receivable, Recorded Investment [Line Items]
Loan Balance		203,178	212,441
Accrued Interest Receivable		974	853
Recorded Investment		204,152	213,294
Installment
Financing Receivable, Recorded Investment [Line Items]
Loan Balance		18,526	19,874
Accrued Interest Receivable		53	67
Recorded Investment		18,579	19,941
Consumer
Financing Receivable, Recorded Investment [Line Items]
Loan Balance		1,241,736	1,120,850
Accrued Interest Receivable		3,808	3,385
Recorded Investment		1,245,544	1,124,235
Leases
Financing Receivable, Recorded Investment [Line Items]
Loan Balance		2,993	3,243
Accrued Interest Receivable		36	29
Recorded Investment		3,029	3,272
Financing Receivable With No Related Allowance Recorded [Member] | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance		19,899	41,075
Impaired Financing Receivable, Recorded Investment		14,704	19,965
Financing Receivable With No Related Allowance Recorded [Member] | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance		18,974	23,961
Impaired Financing Receivable, Recorded Investment		18,060	23,474
Financing Receivable With No Related Allowance Recorded [Member] | Commercial
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance		2,788	3,662
Impaired Financing Receivable, Recorded Investment		1,324	2,226
Financing Receivable With No Related Allowance Recorded [Member] | Commercial
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance		19,346	24,409
Impaired Financing Receivable, Recorded Investment		19,012	22,687
Financing Receivable With Related Allowance Recorded [Member] | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance		5,394	810
Impaired Financing Receivable, Recorded Investment		3,335	659
Impaired Financing Receivable, Related Allowance		681	152
Financing Receivable With Related Allowance Recorded [Member] | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance		137	1,014
Impaired Financing Receivable, Recorded Investment		82	1,000
Impaired Financing Receivable, Related Allowance		2	309
Financing Receivable With Related Allowance Recorded [Member] | Commercial
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance		47	427
Impaired Financing Receivable, Recorded Investment		47	415
Impaired Financing Receivable, Related Allowance		$ 1	$ 87
[1]	Included within commercial, financial and agricultural loans and commercial real estate loans is an immaterial amount of consumer loans that were not broken out by class.

Loans - Recorded Investment in

Loans - Recorded Investment in Nonaccrual, Restructured and Loans Past Due 90 Days or More and Accruing (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 56,564	$ 70,426	$ 80,664
Nonaccrual Loans	72,056	87,822
Accruing TDRs	20,177	18,228
Loans Past Due 90 Days or More and Accruing	1,845	2,138
Total Nonperforming Loans	94,078	108,188
Impaired Financing Receivable, Average Recorded Investment	67,070	79,496	70,762
Impaired Financing Receivable, Interest Income, Cash Basis Method	2,708	4,777	1,963
Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	18,039	20,624	30,595
Nonaccrual Loans	16,773	20,057
Accruing TDRs	1,291	600
Loans Past Due 90 Days or More and Accruing	0	15
Total Nonperforming Loans	18,064	20,672
Impaired Financing Receivable, Average Recorded Investment	23,154	26,821	20,179
Impaired Financing Receivable, Interest Income, Cash Basis Method	963	885	340
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	18,142	24,474	18,025
Nonaccrual Loans	12,979	19,169
Accruing TDRs	5,163	5,305
Loans Past Due 90 Days or More and Accruing	0	0
Total Nonperforming Loans	18,142	24,474
Impaired Financing Receivable, Average Recorded Investment	21,692	22,828	17,883
Impaired Financing Receivable, Interest Income, Cash Basis Method	903	884	550
Commercial
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	1,324	2,226	6,720
Nonaccrual Loans	986	1,833
Accruing TDRs	338	393
Loans Past Due 90 Days or More and Accruing	0	0
Total Nonperforming Loans	1,324	2,226
Impaired Financing Receivable, Average Recorded Investment	1,729	5,503	7,732
Impaired Financing Receivable, Interest Income, Cash Basis Method	64	66	47
Mortgage
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual Loans	8	0
Accruing TDRs	92	104
Loans Past Due 90 Days or More and Accruing	0	0
Total Nonperforming Loans	100	104
Installment
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual Loans	52	61
Accruing TDRs	0	95
Loans Past Due 90 Days or More and Accruing	0	12
Total Nonperforming Loans	52	168
Commercial
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Recorded Investment	19,059	23,102	25,324
Nonaccrual Loans	18,835	23,013
Accruing TDRs	224	89
Loans Past Due 90 Days or More and Accruing	0	0
Total Nonperforming Loans	19,059	23,102
Impaired Financing Receivable, Average Recorded Investment	20,490	24,341	24,968
Impaired Financing Receivable, Interest Income, Cash Basis Method	778	2,942	$ 1,026
Mortgage
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual Loans	16,841	18,313
Accruing TDRs	10,766	9,612
Loans Past Due 90 Days or More and Accruing	568	887
Total Nonperforming Loans	28,175	28,812
HELOC
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual Loans	1,593	1,783
Accruing TDRs	1,025	673
Loans Past Due 90 Days or More and Accruing	14	25
Total Nonperforming Loans	2,632	2,481
Installment
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual Loans	586	644
Accruing TDRs	616	609
Loans Past Due 90 Days or More and Accruing	7	60
Total Nonperforming Loans	1,209	1,313
Consumer
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual Loans	3,403	2,949
Accruing TDRs	662	748
Loans Past Due 90 Days or More and Accruing	1,256	1,139
Total Nonperforming Loans	5,321	4,836
Impaired Financing Receivable, Average Recorded Investment	$ 5	$ 3

Loans - Loans Individually and

Loans - Loans Individually and Collectively Evaluated for Impairment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual and accruing TDRs	$ 92,233	$ 106,050
Loans individually evaluated for impairment	56,564	70,426
Loans collectively evaluated for impairment	35,669	35,624
Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual and accruing TDRs	18,064	20,657
Loans individually evaluated for impairment	18,039	20,624
Loans collectively evaluated for impairment	25	33
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual and accruing TDRs	18,142	24,474
Loans individually evaluated for impairment	18,142	24,474
Loans collectively evaluated for impairment	0	0
Commercial
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual and accruing TDRs	1,324	2,226
Loans individually evaluated for impairment	1,324	2,226
Loans collectively evaluated for impairment	0	0
Mortgage
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual and accruing TDRs	100	104
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	100	104
Installment
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual and accruing TDRs	52	156
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	52	156
Commercial
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual and accruing TDRs	19,059	23,102
Loans individually evaluated for impairment	19,059	23,102
Loans collectively evaluated for impairment	0	0
Mortgage
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual and accruing TDRs	27,607	27,925
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	27,607	27,925
HELOC
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual and accruing TDRs	2,618	2,456
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	2,618	2,456
Installment
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual and accruing TDRs	1,202	1,253
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	1,202	1,253
Consumer
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual and accruing TDRs	4,065	3,697
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	$ 4,065	$ 3,697

Loans - Loans Individually Eva

Loans - Loans Individually Evaluated for Impairment by Class of Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	$ 66,585	$ 95,358
Recorded investment	56,564	70,426	$ 80,664
Allowance for loan losses allocated	684	548
Impaired Financing Receivable, Average Recorded Investment	67,070	79,496	70,762
Impaired Financing Receivable, Interest Income, Cash Basis Method	2,708	4,777	1,963
Commercial, financial and agricultural
Financing Receivable, Impaired [Line Items]
Recorded investment	18,039	20,624	30,595
Impaired Financing Receivable, Average Recorded Investment	23,154	26,821	20,179
Impaired Financing Receivable, Interest Income, Cash Basis Method	963	885	340
Commercial real estate
Financing Receivable, Impaired [Line Items]
Recorded investment	18,142	24,474	18,025
Impaired Financing Receivable, Average Recorded Investment	21,692	22,828	17,883
Impaired Financing Receivable, Interest Income, Cash Basis Method	903	884	550
Commercial
Financing Receivable, Impaired [Line Items]
Recorded investment	1,324	2,226	6,720
Impaired Financing Receivable, Average Recorded Investment	1,729	5,503	7,732
Impaired Financing Receivable, Interest Income, Cash Basis Method	64	66	47
Commercial
Financing Receivable, Impaired [Line Items]
Recorded investment	19,059	23,102	25,324
Impaired Financing Receivable, Average Recorded Investment	20,490	24,341	24,968
Impaired Financing Receivable, Interest Income, Cash Basis Method	778	2,942	$ 1,026
Consumer
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	5	3
With no related allowance recorded | Commercial, financial and agricultural
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	19,899	41,075
Recorded investment	14,704	19,965
With no related allowance recorded | Commercial real estate
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	18,974	23,961
Recorded investment	18,060	23,474
With no related allowance recorded | Commercial
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	2,788	3,662
Recorded investment	1,324	2,226
With no related allowance recorded | Commercial
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	19,346	24,409
Recorded investment	$ 19,012	$ 22,687

Loans - Average Recorded Inves

Loans - Average Recorded Investment and Interest Income Recognized on Loans Individually Evaluated for Impairment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Recorded investment	$ 56,564	$ 70,426	$ 80,664
Average recorded investment	67,070	79,496	70,762
Interest income recognized	2,708	4,777	1,963
Commercial, financial and agricultural
Financing Receivable, Impaired [Line Items]
Recorded investment	18,039	20,624	30,595
Average recorded investment	23,154	26,821	20,179
Interest income recognized	963	885	340
Commercial real estate
Financing Receivable, Impaired [Line Items]
Recorded investment	18,142	24,474	18,025
Average recorded investment	21,692	22,828	17,883
Interest income recognized	903	884	550
Commercial
Financing Receivable, Impaired [Line Items]
Recorded investment	1,324	2,226	6,720
Average recorded investment	1,729	5,503	7,732
Interest income recognized	64	66	47
Commercial
Financing Receivable, Impaired [Line Items]
Recorded investment	19,059	23,102	25,324
Average recorded investment	20,490	24,341	24,968
Interest income recognized	778	2,942	$ 1,026
Consumer
Financing Receivable, Impaired [Line Items]
Average recorded investment	$ 5	$ 3

Loans - Aging of Recorded Inve

Loans - Aging of Recorded Investment in Past Due Loans(Details) - USD ($) $ in Thousands		Dec. 31, 2017		Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days		$ 25,241		$ 26,591
Past due, nonaccrual loans and loans past due 90 days or more and accruing (1)		17,776	[1]	24,050	[2]
Total past due		43,017		50,641
Total current (2)		5,346,125		5,236,189
Recorded Investment		5,389,142		5,286,830
Commercial, financial and agricultural
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days		145		371
Past due, nonaccrual loans and loans past due 90 days or more and accruing (1)		1,043	[1]	4,113	[2]
Total past due		1,188		4,484
Total current (2)		1,056,678		993,693
Recorded Investment	[3]	1,057,866		998,177
Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days		856		355
Past due, nonaccrual loans and loans past due 90 days or more and accruing (1)		2,360	[1]	2,499	[2]
Total past due		3,216		2,854
Total current (2)		1,168,674		1,157,010
Recorded Investment	[3]	1,171,890		1,159,864
Construction real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment		182,017		189,466
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days		29
Past due, nonaccrual loans and loans past due 90 days or more and accruing (1)	[2]			541
Total past due		29		541
Total current (2)		125,761		135,200
Recorded Investment		125,790		135,741
Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days		256		559
Total past due		256		559
Total current (2)		52,080		48,246
Recorded Investment		52,336		48,805
Installment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days		54		223
Past due, nonaccrual loans and loans past due 90 days or more and accruing (1)		19	[1]	64	[2]
Total past due		73		287
Total current (2)		3,818		4,633
Recorded Investment		3,891		4,920
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days		16		330
Past due, nonaccrual loans and loans past due 90 days or more and accruing (1)		1,586	[1]	3,631	[2]
Total past due		1,602		3,961
Total current (2)		392,521		403,666
Recorded Investment		394,123		407,627
Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days		11,515		10,854
Past due, nonaccrual loans and loans past due 90 days or more and accruing (1)		9,232	[1]	9,769	[2]
Total past due		20,747		20,623
Total current (2)		1,091,195		1,150,331
Recorded Investment		1,111,942		1,170,954
HELOC
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days		616		970
Past due, nonaccrual loans and loans past due 90 days or more and accruing (1)		876	[1]	1,020	[2]
Total past due		1,492		1,990
Total current (2)		202,660		211,304
Recorded Investment		204,152		213,294
Installment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days		239		350
Past due, nonaccrual loans and loans past due 90 days or more and accruing (1)		253	[1]	319	[2]
Total past due		492		669
Total current (2)		18,087		19,272
Recorded Investment		18,579		19,941
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing loans past due 30-89 days		11,515		12,579
Past due, nonaccrual loans and loans past due 90 days or more and accruing (1)		2,407	[1]	2,094	[2]
Total past due		13,922		14,673
Total current (2)		1,231,622		1,109,562
Recorded Investment		1,245,544		1,124,235
Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total current (2)		3,029		3,272
Recorded Investment		$ 3,029		$ 3,272
[1]	(1) Includes an aggregate of $1.8 million of loans past due 90 days or more and accruing. The remaining are past due, nonaccrual loans.(2) Includes an aggregate of $56.1 million of nonaccrual loans which are current in regards to contractual principal and interest payments.
[2]	(1) Includes an aggregate of $2.1 million of loans past due 90 days or more and accruing. The remaining are past due, nonaccrual loans.(2) Includes an aggregate of $65.9 million of nonaccrual loans which are current in regards to contractual principal and interest payments.
[3]	Included within commercial, financial and agricultural loans and commercial real estate loans is an immaterial amount of consumer loans that were not broken out by class.

Loans - Recorded Investment by

Loans - Recorded Investment by Loan Grade (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 5,372,483	$ 5,271,857	$ 5,068,085
Five Rated [Member] | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Total loans	17,272	5,826
Five Rated [Member] | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,322	7,548
Five Rated [Member] | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans	278	287
Five Rated [Member] | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans	216	1,055
Five Rated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	23,088	14,716
Six Rated [Member] | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Total loans	153
Six Rated [Member] | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	457	190
Six Rated [Member] | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans		118
Six Rated [Member] | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans	1	124
Six Rated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	611	432
Impaired [Member] | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Total loans	18,064	20,657
Impaired [Member] | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	18,142	24,474
Impaired [Member] | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,324	2,226
Impaired [Member] | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans	19,059	23,102
Impaired [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	56,589	70,459
Pass [Member] | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,022,377	971,694
Pass [Member] | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,147,969	1,127,652
Pass [Member] | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans	124,188	133,110
Pass [Member] | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans	374,847	383,346
Pass [Member] | Leases
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,029	3,272
Pass [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,672,410	2,619,074
Recorded Investment [Member] | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,057,866	998,177
Recorded Investment [Member] | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,171,890	1,159,864
Recorded Investment [Member] | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans	125,790	135,741
Recorded Investment [Member] | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans	394,123	407,627
Recorded Investment [Member] | Leases
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,029	3,272
Recorded Investment [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 2,752,698	$ 2,704,681

Loans - TDR Number of Contract

Loans - TDR Number of Contracts Modified And Recorded Investment (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)contracts	Dec. 31, 2016USD ($)contracts	Dec. 31, 2015USD ($)contracts
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts | contracts	426	405	424
Total Recorded Investment Modified as TDRs During Period	$ 10,125	$ 21,258	$ 23,324
Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts | contracts	29	32	39
Total Recorded Investment Modified as TDRs During Period	$ 3,715	$ 8,641	$ 12,588
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts | contracts	9	14	14
Total Recorded Investment Modified as TDRs During Period	$ 1,363	$ 6,381	$ 4,160
Commercial
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts | contracts	0	2	2
Total Recorded Investment Modified as TDRs During Period		$ 1,143	$ 513
Mortgage
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts | contracts	1	0	1
Total Recorded Investment Modified as TDRs During Period	$ 8		$ 19
Installment
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts | contracts	0	1	0
Commercial
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts | contracts	15	11	11
Total Recorded Investment Modified as TDRs During Period	$ 630	$ 1,122	$ 1,185
Mortgage
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts | contracts	33	34	39
Total Recorded Investment Modified as TDRs During Period	$ 2,247	$ 2,406	$ 3,254
HELOC
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts | contracts	19	13	26
Total Recorded Investment Modified as TDRs During Period	$ 576	$ 282	$ 360
Installment
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts | contracts	11	5	9
Total Recorded Investment Modified as TDRs During Period	$ 294	$ 105	$ 155
Consumer
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts | contracts	309	293	283
Total Recorded Investment Modified as TDRs During Period	$ 1,292	$ 1,178	$ 1,090
Accruing
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	3,923	4,628	11,766
Accruing | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	945	191	8,948
Accruing | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	1,050	3,844	637
Accruing | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period			513
Accruing | Mortgage
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	0	0	19
Accruing | Installment
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	0	0	0
Accruing | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	144	89
Accruing | Mortgage
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	888	114	1,132
Accruing | HELOC
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	474	104	315
Accruing | Installment
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	251	102
Accruing | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	171	184	202
Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	6,202	16,630	11,558
Nonaccrual | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	2,770	8,450	3,640
Nonaccrual | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	313	2,537	3,523
Nonaccrual | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period		1,143
Nonaccrual | Mortgage
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	8
Nonaccrual | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	486	1,033	1,185
Nonaccrual | Mortgage
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	1,359	2,292	2,122
Nonaccrual | HELOC
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	102	178	45
Nonaccrual | Installment
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	43	3	155
Nonaccrual | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total Recorded Investment Modified as TDRs During Period	$ 1,121	$ 994	$ 888

Loans - Recorded Investment 80

Loans - Recorded Investment in Financing Receivable Modified as TDR Within 12 Month (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)contracts	Dec. 31, 2016USD ($)contracts	Dec. 31, 2015USD ($)contracts
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts	64	97	67
Recorded Investment | $	$ 1,235	$ 3,798	$ 2,854
Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts	0	7	1
Recorded Investment | $		$ 419	$ 1
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts	2	5	1
Recorded Investment | $	$ 82	$ 843	$ 626
Commercial
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts	0	0	0
Mortgage
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts	0	0	0
Recorded Investment | $	$ 0
Installment
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts	0	0	0
Recorded Investment | $	$ 0
Commercial
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts	2	7	3
Recorded Investment | $	$ 117	$ 848	$ 1,005
Mortgage
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts	6	15	12
Recorded Investment | $	$ 467	$ 1,201	$ 682
HELOC
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts	4	0	1
Recorded Investment | $	$ 194		$ 5
Installment
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts	0	1	2
Recorded Investment | $	$ 0	$ 3	$ 101
Leases
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts	50	62	47
Recorded Investment | $	$ 375	$ 484	$ 434
Leases
Financing Receivable, Recorded Investment [Line Items]
Number of Contracts	0	0	0
Recorded Investment | $	$ 0

Allowance for Loan Losses - Al

Allowance for Loan Losses - Allowance Calculation at the Segment Level and Adjusted Beginning Balance for the Allowance for Credit Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Reserve Estimate Methodology, Historical Loss Period Factor	96 months	84 months
Beginning balance	$ 50,624	$ 56,494	$ 54,352
Charge-offs	19,403	20,799	14,290
Recoveries	(10,210)	(20,030)	(11,442)
Net charge-offs (recoveries)	9,193	769	2,848
Provision (Recovery)	8,557	(5,101)	4,990
Ending balance	49,988	50,624	56,494
Commercial, financial and agricultural
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	13,434	13,694	10,719
Charge-offs	6,017	5,786	2,478
Recoveries	(809)	(1,259)	(1,373)
Net charge-offs (recoveries)	5,208	4,527	1,105
Provision (Recovery)	6,796	4,267	4,080
Ending balance	15,022	13,434	13,694
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	10,432	9,197	8,808
Charge-offs	1,798	412	348
Recoveries	(810)	(3,671)	(2,241)
Net charge-offs (recoveries)	988	(3,259)	(1,893)
Provision (Recovery)	157	(2,024)	(1,504)
Ending balance	9,601	10,432	9,197
Construction real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	5,247	8,564	8,652
Charge-offs	105	1,436	470
Recoveries	(2,124)	(8,559)	(2,092)
Net charge-offs (recoveries)	(2,019)	(7,123)	(1,622)
Provision (Recovery)	(2,836)	(10,440)	(1,710)
Ending balance	4,430	5,247	8,564
Residential real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	10,958	13,514	14,772
Charge-offs	1,208	3,014	2,352
Recoveries	(1,863)	(2,446)	(2,438)
Net charge-offs (recoveries)	(655)	568	(86)
Provision (Recovery)	(2,292)	(1,988)	(1,344)
Ending balance	9,321	10,958	13,514
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	10,553	11,524	11,401
Charge-offs	10,275	10,151	8,642
Recoveries	(4,603)	(4,094)	(3,295)
Net charge-offs (recoveries)	5,672	6,057	5,347
Provision (Recovery)	6,733	5,086	5,470
Ending balance	11,614	10,553	11,524
Leases
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	0	1	0
Charge-offs	0	0	0
Recoveries	(1)	(1)	(3)
Net charge-offs (recoveries)	(1)	(1)	(3)
Provision (Recovery)	(1)	(2)	(2)
Ending balance	$ 0	$ 0	$ 1

Allowance for Loan Losses - Co

Allowance for Loan Losses - Composition of the Allowance for Loan Losses (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Allowance		$ 49,988	$ 50,624	$ 56,494	$ 54,352
Ending allowance balance attributed to loans
Individually evaluated for impairment		684	548
Collectively evaluated for impairment		49,304	50,076
Total ending allowance balance		49,988	50,624
Loan Balance:
Loans individually evaluated for impairment		56,545	70,415
Loans collectively evaluated for impairment		5,315,938	5,201,442
Total ending loan balance		$ 5,372,483	$ 5,271,857
Allowance for loan losses as a percentage of loan balance:
Loans individually evaluated for impairment		1.21%	0.78%
Loans collectively evaluated for impairment		0.93%	0.96%
Total		0.93%	0.96%
Recorded Investment:
Loans individually evaluated for impairment		$ 56,564	$ 70,426
Loans collectively evaluated for impairment		5,332,578	5,216,404
Recorded Investment		5,389,142	5,286,830
Financing Receivable, Allowance for Credit Losses, Write-downs		19,403	20,799	14,290
Financing Receivable, Allowance for Credit Losses, Recovery		(10,210)	(20,030)	(11,442)
Financing Receivables Allowance For Credit Losses Net Charge Offs		9,193	769	2,848
Provision for Loan, Lease, and Other Losses		8,557	(5,101)	4,990
Commercial, financial and agricultural
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Allowance		15,022	13,434	13,694	10,719
Ending allowance balance attributed to loans
Individually evaluated for impairment		681	152
Collectively evaluated for impairment		14,341	13,282
Total ending allowance balance		15,022	13,434
Loan Balance:
Loans individually evaluated for impairment		18,034	20,622
Loans collectively evaluated for impairment		1,035,419	973,997
Total ending loan balance	[1]	$ 1,053,453	$ 994,619
Allowance for loan losses as a percentage of loan balance:
Loans individually evaluated for impairment		3.78%	0.74%
Loans collectively evaluated for impairment		1.39%	1.36%
Total		1.43%	1.35%
Recorded Investment:
Loans individually evaluated for impairment		$ 18,039	$ 20,624
Loans collectively evaluated for impairment		1,039,827	977,553
Recorded Investment	[1]	1,057,866	998,177
Financing Receivable, Allowance for Credit Losses, Write-downs		6,017	5,786	2,478
Financing Receivable, Allowance for Credit Losses, Recovery		(809)	(1,259)	(1,373)
Financing Receivables Allowance For Credit Losses Net Charge Offs		5,208	4,527	1,105
Provision for Loan, Lease, and Other Losses		6,796	4,267	4,080
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Allowance		9,601	10,432	9,197	8,808
Ending allowance balance attributed to loans
Individually evaluated for impairment		2	309
Collectively evaluated for impairment		9,599	10,123
Total ending allowance balance		9,601	10,432
Loan Balance:
Loans individually evaluated for impairment		18,131	24,465
Loans collectively evaluated for impairment		1,149,476	1,131,238
Total ending loan balance	[1]	$ 1,167,607	$ 1,155,703
Allowance for loan losses as a percentage of loan balance:
Loans individually evaluated for impairment		0.01%	1.26%
Loans collectively evaluated for impairment		0.84%	0.89%
Total		0.82%	0.90%
Recorded Investment:
Loans individually evaluated for impairment		$ 18,142	$ 24,474
Loans collectively evaluated for impairment		1,153,748	1,135,390
Recorded Investment	[1]	1,171,890	1,159,864
Financing Receivable, Allowance for Credit Losses, Write-downs		1,798	412	348
Financing Receivable, Allowance for Credit Losses, Recovery		(810)	(3,671)	(2,241)
Financing Receivables Allowance For Credit Losses Net Charge Offs		988	(3,259)	(1,893)
Provision for Loan, Lease, and Other Losses		157	(2,024)	(1,504)
Construction real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Allowance		4,430	5,247	8,564	8,652
Ending allowance balance attributed to loans
Individually evaluated for impairment		0	0
Collectively evaluated for impairment		4,430	5,247
Total ending allowance balance		4,430	5,247
Loan Balance:
Loans individually evaluated for impairment		1,322	2,226
Loans collectively evaluated for impairment		180,148	186,719
Total ending loan balance		$ 181,470	$ 188,945
Allowance for loan losses as a percentage of loan balance:
Loans individually evaluated for impairment		0.00%	0.00%
Loans collectively evaluated for impairment		2.46%	2.81%
Total		2.44%	2.78%
Recorded Investment:
Loans individually evaluated for impairment		$ 1,324	$ 2,226
Loans collectively evaluated for impairment		180,693	187,240
Recorded Investment		182,017	189,466
Financing Receivable, Allowance for Credit Losses, Write-downs		105	1,436	470
Financing Receivable, Allowance for Credit Losses, Recovery		(2,124)	(8,559)	(2,092)
Financing Receivables Allowance For Credit Losses Net Charge Offs		(2,019)	(7,123)	(1,622)
Provision for Loan, Lease, and Other Losses		(2,836)	(10,440)	(1,710)
Residential real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Allowance		9,321	10,958	13,514	14,772
Ending allowance balance attributed to loans
Individually evaluated for impairment		1	87
Collectively evaluated for impairment		9,320	10,871
Total ending allowance balance		9,321	10,958
Loan Balance:
Loans individually evaluated for impairment		19,058	23,102
Loans collectively evaluated for impairment		1,706,166	1,785,395
Total ending loan balance		$ 1,725,224	$ 1,808,497
Allowance for loan losses as a percentage of loan balance:
Loans individually evaluated for impairment		0.01%	0.38%
Loans collectively evaluated for impairment		0.55%	0.61%
Total		0.54%	0.61%
Recorded Investment:
Loans individually evaluated for impairment		$ 19,059	$ 23,102
Loans collectively evaluated for impairment		1,709,737	1,788,714
Recorded Investment		1,728,796	1,811,816
Financing Receivable, Allowance for Credit Losses, Write-downs		1,208	3,014	2,352
Financing Receivable, Allowance for Credit Losses, Recovery		(1,863)	(2,446)	(2,438)
Financing Receivables Allowance For Credit Losses Net Charge Offs		(655)	568	(86)
Provision for Loan, Lease, and Other Losses		(2,292)	(1,988)	(1,344)
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Allowance		11,614	10,553	11,524	11,401
Ending allowance balance attributed to loans
Individually evaluated for impairment		0	0
Collectively evaluated for impairment		11,614	10,553
Total ending allowance balance		11,614	10,553
Loan Balance:
Loans individually evaluated for impairment		0	0
Loans collectively evaluated for impairment		1,241,736	1,120,850
Total ending loan balance		$ 1,241,736	$ 1,120,850
Allowance for loan losses as a percentage of loan balance:
Loans individually evaluated for impairment		0.00%	0.00%
Loans collectively evaluated for impairment		0.94%	0.94%
Total		0.94%	0.94%
Recorded Investment:
Loans individually evaluated for impairment		$ 0	$ 0
Loans collectively evaluated for impairment		1,245,544	1,124,235
Recorded Investment		1,245,544	1,124,235
Financing Receivable, Allowance for Credit Losses, Write-downs		10,275	10,151	8,642
Financing Receivable, Allowance for Credit Losses, Recovery		(4,603)	(4,094)	(3,295)
Financing Receivables Allowance For Credit Losses Net Charge Offs		5,672	6,057	5,347
Provision for Loan, Lease, and Other Losses		6,733	5,086	5,470
Leases
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Allowance		0	0	1	$ 0
Ending allowance balance attributed to loans
Individually evaluated for impairment		0	0
Collectively evaluated for impairment		0	0
Total ending allowance balance		0	0
Loan Balance:
Loans individually evaluated for impairment		0	0
Loans collectively evaluated for impairment		2,993	3,243
Total ending loan balance		$ 2,993	$ 3,243
Allowance for loan losses as a percentage of loan balance:
Loans individually evaluated for impairment		0.00%	0.00%
Loans collectively evaluated for impairment		0.00%	0.00%
Total		0.00%	0.00%
Recorded Investment:
Loans individually evaluated for impairment		$ 0	$ 0
Loans collectively evaluated for impairment		3,029	3,272
Recorded Investment		3,029	3,272
Financing Receivable, Allowance for Credit Losses, Write-downs		0	0	0
Financing Receivable, Allowance for Credit Losses, Recovery		(1)	(1)	(3)
Financing Receivables Allowance For Credit Losses Net Charge Offs		(1)	(1)	(3)
Provision for Loan, Lease, and Other Losses		$ (1)	$ (2)	$ (2)
[1]	Included within commercial, financial and agricultural loans and commercial real estate loans is an immaterial amount of consumer loans that were not broken out by class.

Loans Held for Sale Narrative (

Loans Held for Sale Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans Held for Sale [Line Items]
Disposal Group, Including Discontinued Operation, Mortgage Loans	$ 4,148,000	$ 10,413,000
Loans Held-for-sale, Mortgages, Contractual Balance	4,100,000	10,300,000
Expected Gain (Loss) on Sale of Mortgage Loans	55,000	$ 131,000
Commercial Portfolio Segment [Member]
Loans Held for Sale [Line Items]
Loans held for sale - lower of cost or market	$ 0		$ 100,000
Gain on sale of loans in secondary market			$ 800,000

Other Real Estate Owned (Detail

Other Real Estate Owned (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Assets Repossessed or Foreclosed, or loans in process of foreclosure [Line Items]
Other Real Estate, Foreclosed Assets, and Repossessed Assets	$ 14,190	$ 13,926
Construction real estate
Schedule of Assets Repossessed or Foreclosed, or loans in process of foreclosure [Line Items]
Other Real Estate, Foreclosed Assets, and Repossessed Assets	4,852	4,624
Commercial Real Estate [Member]
Schedule of Assets Repossessed or Foreclosed, or loans in process of foreclosure [Line Items]
Other Real Estate, Foreclosed Assets, and Repossessed Assets	7,888	7,642
Residential real estate
Schedule of Assets Repossessed or Foreclosed, or loans in process of foreclosure [Line Items]
Other Real Estate, Foreclosed Assets, and Repossessed Assets	1,450	1,660
Mortgage Loans in Process of Foreclosure, Amount	$ 2,948	$ 3,250

Premises And Equipment - Narra

Premises And Equipment - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 8.6	$ 8.4	$ 7.3
Rent expense	$ 2	$ 2.1	$ 1.7

Premises And Equipment - Major

Premises And Equipment - Major Categories of Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Premises and Equipment, Gross	$ 156,386	$ 151,168
Less accumulated depreciation	(100,485)	(93,197)
Premises and equipment, net	55,901	57,971
Land
Property, Plant and Equipment [Line Items]
Premises and Equipment, Gross	19,603	19,577
Buildings
Property, Plant and Equipment [Line Items]
Premises and Equipment, Gross	77,711	75,472
Equipment, furniture and fixtures
Property, Plant and Equipment [Line Items]
Premises and Equipment, Gross	55,799	52,719
Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and Equipment, Gross	$ 3,273	$ 3,400

Premises And Equipment - Schedu

Premises And Equipment - Schedule of Future Minimum Rental Payments Under Operating Leases (Details) $ in Thousands	Dec. 31, 2017USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2,017	$ 1,726
2,018	1,563
2,019	865
2,020	502
2,021	446
Thereafter	307
Total	$ 5,409

Investment in Qualified Affor88

Investment in Qualified Affordable Housing (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity investments		$ 3,500	$ 3,500
Investment in qualified affordable housing tax credits amortization		$ 10,278	$ 7,300	$ 6,664
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%	35.00%	35.00%
Affordable Housing Tax Credits and Other Tax Benefits, Amount		$ 9,400	$ 9,400	$ 8,900
Affordable Housing Program Obligation		14,282	14,282
Qualified Affordable Housing [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity investments		49,669	$ 52,947
Change in Accounting Method Accounted for as Change in Estimate [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Investment in qualified affordable housing tax credits amortization		$ 3,100
Subsequent Event [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%

Deposits - Narrative (Details)

Deposits - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deposits [Abstract]
Deposits received from executive officers, directors, and their related interests	$ 24.9	$ 26.5
Time Deposits, $250,000 or more	$ 36.3	$ 43.3

Deposits - Summary of Noninter

Deposits - Summary of Noninterest Bearing and Interest Bearing Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deposits [Abstract]
Non-interest bearing	$ 1,633,941	$ 1,523,417
Interest bearing	4,183,385	3,998,539
Total deposits	$ 5,817,326	$ 5,521,956	$ 5,347,642

Deposits - Time Deposits (Deta

Deposits - Time Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deposits [Abstract]
Time Deposits, $250,000 or more	$ 36,300	$ 43,300
Time Deposits, Fiscal Year Maturity [Abstract]
2,017	590,331
2,018	217,286
2,019	119,452
2,020	51,958
2,021	53,917
After 5 years	532
Total	$ 1,033,476

Repurchase Agreement Borrowin92

Repurchase Agreement Borrowings (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Nov. 30, 2012
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
ERROR in label resolution.	$ 975,000	$ 640,000
Pledged Assets Separately Reported, Securities Pledged for Repurchase Agreements, at Fair Value	213,000	569,000
Transfers Accounted for as Secured Borrowings, Associated Liabilities, Carrying Amount	183,289	509,795
Maturity Greater than 90 Days [Member]
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers Accounted for as Secured Borrowings, Associated Liabilities, Carrying Amount	1,104	301,104
Maturity 30 to 90 Days [Member]
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers Accounted for as Secured Borrowings, Associated Liabilities, Carrying Amount	0	0
Maturity Less than 30 Days [Member]
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers Accounted for as Secured Borrowings, Associated Liabilities, Carrying Amount	0	0
Maturity Overnight [Member]
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers Accounted for as Secured Borrowings, Associated Liabilities, Carrying Amount	$ 182,185	$ 208,691
Long-term Debt [Member]
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers Accounted for as Secured Borrowings, Associated Liabilities, Carrying Amount			$ 300,000

Short-Term Borrowings - Narrat

Short-Term Borrowings - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Money Pledged as Collateral for FHLB Advance Borrowings	$ 25	$ 25
FHLB Advances
Short-term Debt [Line Items]
Commercial real estate and residential mortgage loans pledged under blanket agreement	$ 1,789	$ 1,909

Short-Term Borrowings - Schedu

Short-Term Borrowings - Schedule of Short-Term Borrowings (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Securities sold under agreements to repurchase	$ 183,289	$ 209,795
FHLB advances	208,000	185,000
Total short-term borrowings	391,289	394,795
FHLB Advances
Short-term Debt [Line Items]
Total short-term borrowings	208,000	185,000
Highest month-end balance	208,000	185,000
Short-term Debt, Average Outstanding Amount	$ 23,924	$ 15,694
Weighted-average interest rate:
As of year-end	1.64%	0.80%
Paid during the year	1.16%	0.63%
Securities Sold under Agreements to Repurchase [Member]
Short-term Debt [Line Items]
Total short-term borrowings	$ 183,289	$ 209,795
Highest month-end balance	230,905	248,277
Short-term Debt, Average Outstanding Amount	$ 205,269	$ 224,763
Weighted-average interest rate:
As of year-end	0.41%	0.17%
Paid during the year	0.35%	0.16%

Long-Term Debt - Narrative (De

Long-Term Debt - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Nov. 30, 2012
Debt Instrument [Line Items]
Prepayment penalty on long-term debt	$ 0	$ 5,554	$ 532
Gains (Losses) on Restructuring of Debt		5,600	500	$ 3,200
Amortization of prepayment penalty on long-term debt	5,719	6,176	6,047
Prepayment Penalty, Future Amortization Expense [Abstract]
Long-term Debt, Maturities, Repayments of Principal after Year Five	100,000
Money Pledged as Collateral for FHLB Advance Borrowings	25,000	25,000
FHLB Debt Prepaid		$ 50,000	$ 54,500
FHLB Debt Prepaid Weighted Avg Rate		3150.00%	1.59%
FHLB Debt Amount Restructured				$ 50,000
Broker Repurchase Agreements
Debt Instrument [Line Items]
Debt repurchased during period					$ 300,000
Debt repurchased during period, rate					1.75%
Prepayment penalty on long-term debt	$ 25,000
Effective interest rate percentage	3.55%
Prepayment Penalty, Future Amortization Expense [Abstract]
Payments of Debt Extinguishment Costs, Amount to be Amortized in Year Two	$ 0
Federal Home Loan Bank Certificates and Obligations (FHLB) [Member]
Debt Instrument [Line Items]
Debt repurchased during period, rate				1.25%
Effective interest rate percentage	3.52%
Prepayment Penalty, Future Amortization Expense [Abstract]
Payments of Debt Extinguishment Costs, Amount to be Amortized in Year Two	$ 0

Long-Term Debt - Schedule of l

Long-Term Debt - Schedule of long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year	$ 0
Long-term Debt, Fiscal Year Maturity [Abstract]
2,017	150,000	$ 350,000
2,018	100,000	150,000
2,019	50,000	75,000
2,020	100,000	25,000
2,021	0	0
2,021		0
Thereafter		100,000
Total long-term debt, excluding prepayment penalty	500,000	700,000
Prepayment penalty	0	(5,719)
Total long-term debt	$ 500,000	$ 694,281
Long-term Debt, Fiscal Year Maturity, Average Rate [Abstract] [Abstract]
2,017	2.04%	1.68%
2,018	1.92%	2.04%
2,019	2.04%	1.96%
2,020	1.96%	2.14%
2,021	0.00%	0.00%
2,021		0.00%
Long-term Debt, Maturities, Repayments of Principal after Year Five	$ 100,000
Thereafter		3.40%
Average rate, total, excluding prepayment penalty	2.27%	2.05%
Average rate, total	2.27%	2.07%
Long Term Debt Maturities Average Rate In After Year Five	3.40%
FHLB Advances
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year	$ 0
Long-term Debt, Fiscal Year Maturity [Abstract]
2,017	150,000	$ 50,000
2,018	100,000	150,000
2,019	50,000	75,000
2,020	100,000	25,000
2,021	0	0
2,021		0
Thereafter		100,000
Total long-term debt, excluding prepayment penalty	$ 500,000	$ 400,000
Long-term Debt, Fiscal Year Maturity, Average Rate [Abstract] [Abstract]
2,017	2.04%	1.25%
2,018	1.92%	2.04%
2,019	2.04%	1.96%
2,020	1.96%	2.14%
2,021	0.00%	0.00%
2,021		0.00%
Long-term Debt, Maturities, Repayments of Principal after Year Five	$ 100,000
Thereafter		3.40%
Average rate, total, excluding prepayment penalty	2.27%	2.27%
Long Term Debt Maturities Average Rate In After Year Five	3.40%
Broker Repurchase Agreements
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year	$ 0
Long-term Debt, Fiscal Year Maturity [Abstract]
2,017		$ 300,000
Total long-term debt, excluding prepayment penalty	$ 0	$ 300,000
Long-term Debt, Fiscal Year Maturity, Average Rate [Abstract] [Abstract]
2,017		1.75%
Average rate, total, excluding prepayment penalty	0.00%	1.75%

Subordinated Notes (Details)

Subordinated Notes (Details)	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Apr. 20, 2012USD ($)purchaser
Subordinated notes	$ 15,000,000	$ 45,000,000
Trust I
Preferred securities issued	15,000,000
Junior subordinated notes
Junior subordinated debt purchased by Trust I	$ 15,500,000
Trust preferred securities
Variable rate basis	three-month LIBOR plus 148 basis points
Basis spread on variable rate (percent)	1.48%
Subordinated debt | 7% Subordinated notes due April 20, 2022
Subordinated borrowing, number of purchasers | purchaser			56
Aggregate principal amount			$ 30,000,000
Interest rate	7.00%
Interest Expense, Debt	$ 140,000

Contingent Liabilities (Details

Contingent Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Loss Contingency Accrual	$ 0	$ 2.3

Share-Based Compensation - Nar

Share-Based Compensation - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number	103,319
Treasury Stock Reissued Shares For Director Grants	11,150	9,950	10,150
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost	$ 1,240,000	$ 950,000	$ 963,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	85,425	44,700
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	(9,674)	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(3,021)	(825)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease)	(1,802)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	116,716	85,425	44,700
Allocated Share-based Compensation Expense	$ 5,223,000
Shares Paid for Tax Withholding for Share Based Compensation	3,293
Restricted Stock, Shares Issued Net of Shares for Tax Withholdings	6,381
2013 Long Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares authorized for delivery upon the exercise of incentive stock options	600,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Period Increase (Decrease)	116,716
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	45,788	41,550	23,025
Allocated Share-based Compensation Expense	$ 2,701,000	$ 1,864,000	$ 865,000
2017 Employees Long Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	750,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	750,000
2017 Non Employee Directors LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	150,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	138,850
Common Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Treasury Stock Reissued Shares For Director Grants	11,150	9,950	10,150
Allocated Share-based Compensation Expense	$ 2,701,000	$ 1,864,000	$ 865,000
Expense to be paid next twelve months [Domain]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	2,446,000
Expense to be paid Year Two [Domain]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	1,818,000
Expense to be paid Year Three [Domain]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	822,000
Expense to be paid Year Four [Domain]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 137,000

Benefit Plans - Narrative (Det

Benefit Plans - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Nov. 17, 2009
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)		$ 21,773,000	$ 7,993,000
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate		3.89%	4.58%	4.88%
Defined Benefit Plan, Plan Assets, Contributions by Employer		$ 15,000,000	$ 0
Expected long-term rate of return on plan assets		7.00%
Accumulated benefit obligation for the pension plan		$ 116,000,000	$ 97,200,000
Common share purchased under pension plan, shares					115,800
Common share purchased under pension plan, value					$ 7,000,000
Common share purchased under pension plan, value per share					$ 60.45
Fair value, pension plan common shares held, shares		115,800	115,800
Fair value of common shares held by pension plan		$ 12,000,000	$ 13,900,000
Fair value of common shares held by pension plan, per share		$ 104	$ 119.66
Estimated net actuarial (loss) expected to be recognized in the next fiscal year		$ 1,361,000
Expected long-term return on plan assets		7.00%	7.25%	7.25%
Market value of pension plan assets		$ 195,700,000	$ 167,000,000
Equity investments		3,500,000	3,500,000
Defined Contribution Plan, Cost		1,300,000	1,300,000	$ 1,200,000
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Estimated prior service costs expected to be recognized in net periodic benefit cost during next fiscal year		0
Supplemental Executive Retirement Plan (SERP)
Defined Benefit Plan Disclosure [Line Items]
Benefit expense		1,700,000	1,500,000	$ 1,100,000
Accrued benefit cost		9,900,000	8,800,000
Level 1
Defined Benefit Plan Disclosure [Line Items]
Equity investments		169,600,000	145,900,000
Level 2
Defined Benefit Plan Disclosure [Line Items]
Equity investments		26,100,000	21,100,000
Level 3
Defined Benefit Plan Disclosure [Line Items]
Equity investments		0	$ 0
Subsequent Event [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 0
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Market value of pension plan assets		$ 12,200,000

Benefit Plans - Plan Assets an

Benefit Plans - Plan Assets and Benefit Obligation Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Change in fair value of plan assets
Fair value at beginning of measurement period	$ 167,047	$ 153,498
Actual return on plan assets	21,573	19,256
Benefits paid	(7,885)	(5,707)
Fair value at end of measurement period	195,735	167,047	$ 153,498
Change in benefit obligation
Projected benefit obligation at beginning of measurement period	114,455	102,245
Service cost	5,270	5,055	5,368
Interest cost	5,085	4,869	4,695
Actuarial loss	21,773	7,993
Benefits paid	7,885	5,707
Projected benefit obligation at the end of measurement period	138,698	114,455	$ 102,245
Funded status at end of year (fair value of plan assets less benefit obligation)	57,037	52,592
Defined Benefit Plan, Plan Assets, Contributions by Employer	15,000	0
Defined Benefit Plan, Plan Assets, Benefits Paid	$ 7,885	$ 5,707

Benefit Plans - Asset Allocati

Benefit Plans - Asset Allocation for the Pension Plan by Asset Category (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 15,000	$ 0
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual Plan Asset Allocations	100.00%	100.00%
Defined Benefit Plan, Expected Return on Plan Assets, Percentage	7.00%
Equity securities
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual Plan Asset Allocations	79.00%	84.00%
Fixed income and cash equivalents
Defined Benefit Plan, Information about Plan Assets [Abstract]
Actual Plan Asset Allocations	21.00%	16.00%

Benefit Plans - Weighted Avera

Benefit Plans - Weighted Average Assumptions Used to Determine Benefit Obligations (Details)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate	3.89%	4.58%	4.88%
Rate of compensation increase
Ages 50 and over [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Rate of compensation increase	3000.00%	3000.00%	3000.00%
Ages 40-49 [Domain]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Rate of compensation increase	4.00%	4.00%	3.00%
Ages 30-39 [Member] [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Rate of compensation increase	6.00%	6.00%	6.00%
Under age 30 [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Rate of compensation increase	10.00%	10.00%	10.00%

Benefit Plans - Estimated Futu

Benefit Plans - Estimated Future Pension Benefit Payments (Details) $ in Thousands	Dec. 31, 2017USD ($)
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2,017	$ 8,274
2,018	8,404
2,019	9,320
2,020	10,526
2,021	10,937
2022-2026	53,456
Total	$ 100,917

Benefit Plans - Balances of Ac

Benefit Plans - Balances of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Prior service cost	$ 0	$ 0
Net actuarial loss	(33,799)	(22,677)
Total	(33,799)	(22,677)
Deferred taxes	(7,098)	(7,937)
Tax Effect of Extraordinary Item, Gain (Loss)	3,175	0
Accumulated other comprehensive loss	$ (23,526)	$ (14,740)

Benefit Plans - Components of

Benefit Plans - Components of Net Periodic Benefit Cost and Other Amounts Recognized in Other Comprehensive Income (Loss) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of net periodic benefit cost
Service cost	$ (5,270,000)	$ (5,055,000)	$ (5,368,000)
Interest cost	(5,085,000)	(4,869,000)	(4,695,000)
Expected return on plan assets	11,455,000	10,950,000	11,420,000
Amortization of prior service cost	0	0	(15,000)
Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year	(576,000)	(773,000)	(637,000)
Net periodic benefit income	(524,000)	(253,000)	(705,000)
Other amounts recognized in other comprehensive (Loss)
Change to net actuarial (loss) gain for the period	(11,698,000)	168,000	(1,400,000)
Amortization of net loss	576,000	773,000	637,000
Total recognized in other comprehensive income	(11,122,000)	941,000	(748,000)
Total recognized in net benefit income and other comprehensive income	$ (10,598,000)	$ 1,194,000	$ (43,000)

Benefit Plans - Weighted Av107

Benefit Plans - Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase
Expected long-term return on plan assets	7.00%	7.25%	7.25%
Discount Rate	4.58%	4.88%	4.42%
Ages 30-39 [Member] [Member]
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	6.00%	6.00%	6.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	6.00%	6.00%	6.00%
Under age 30 [Member]
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	10.00%	10.00%	10.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	10.00%	10.00%	10.00%
Ages 40-49 [Domain]
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	4.00%	4.00%	3.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	4.00%	3.00%	3.00%
Ages 50 and over [Member]
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	3000.00%	3000.00%	3000.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	3.00%	3.00%	3.00%

Income Taxes - Components of D

Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%	35.00%	35.00%
Investment in qualified affordable housing tax credits amortization		$ 10,278	$ 7,300	$ 6,664
Current Federal Tax Expense (Benefit)		1,200
Deferred tax assets:
Allowance for loan losses		10,498	17,719
Accumulated other comprehensive loss – Pension plan		7,098	7,937
Accumulated other comprehensive loss – Unrealized losses on securities		946	1,618
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Compensation		2,744	4,140
Deferred compensation		1,327	2,322
Net deferred loan fees		1,115	1,397
Deferred contract bonus		645	1,074
Nonvested equity-based compensation		1,069	1,115
Fixed assets		877	781
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Legal Settlements		4	793
Other		1,226	2,525
Total deferred tax assets		27,549	41,421
Deferred tax liabilities:
Deferred investment income		6,120	10,199
Pension plan		19,076	26,344
Mortgage servicing rights		2,034	3,243
Partnership adjustments		460	549
Other		364	596
Total deferred tax liabilities		28,054	40,931
Net deferred tax (liability) asset		(505)
Deferred Tax Assets, Net			$ 490
Change in Accounting Method Accounted for as Change in Estimate [Member]
Investment in qualified affordable housing tax credits amortization		$ 3,100
Subsequent Event [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%

Income Taxes - Components of t

Income Taxes - Components of the Provision for Federal and State Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Currently payable
Federal	$ 20,660	$ 28,879	$ 26,153
Other Tax Expense (Benefit)	10,278	7,300	6,664
Deferred
Federal	3,289	581	(250)
Total	$ 34,227	$ 36,760	$ 32,567

Income Taxes - Reconciliation

Income Taxes - Reconciliation of Federal Income Tax Expense (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments, Owned, Federal Income Tax Note [Line Items]
Income Tax Examination, Penalties and Interest Expense	$ 3,500	$ 1,500	$ 2,000
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Statutory federal corporate tax rate	35.00%	35.00%	35.00%
Changes in rates resulting from:
Tax exempt interest income, net of disallowed interest	(2.80%)	(1.30%)	(0.50%)
Bank owned life insurance	(1.40%)	(1.20%)	(1.80%)
Effective Income Tax Rate Reconciliation, Investment in Qualified Affordable Housing, Percent	(1.90%)	(1.70%)	(1.90%)
Investments in qualified affordable housing projects, net of tax benefits	(0.00%)	(0.00%)	(0.90%)
Effective Income Tax Rate Reconciliation, Deduction, Employee Stock Ownership Plan Dividend, Percent	(1.00%)	(1.00%)	(1.00%)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	1.00%	0.00%	0.00%
Other	(0.00%)	0.10%	(0.20%)
Effective tax rate	28.90%	29.90%	28.70%
Deferred Tax Liabilities, Deferred Expense	$ 1,900,000

Income Taxes - Reconciliati111

Income Taxes - Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 506,000	$ 482,000	$ 432,000
Income Tax Examination, Penalties and Interest Expense	3,500	1,500	2,000
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
January 1 Balance	633,000	558,000	532,000
Additions based on tax positions related to the current year	117,000	117,000	80,000
Additions for tax positions of prior years	0	38,000	16,000
Reductions for tax positions of prior years	(9,000)	0	0
Reductions due to statute of limitations	(77,000)	(80,000)	(70,000)
December 31 Balance	664,000	633,000	558,000
Income Tax Examination, Penalties and Interest Accrued	$ 74,000	$ 70,500	$ 69,000

Other Comprehensive Income (112

Other Comprehensive Income (Loss) - Components of Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	$ 0	$ 0	$ 15
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	576	773	637
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax	576	773	652
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax	121	271	228
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	23,526	14,740	15,351	$ 14,865
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	(2,928)	(3,005)	(292)	1,257
Accumulated Other Comprehensive Income (Loss), Net of Tax	(26,454)	(17,745)	(15,643)	$ (13,608)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	(8,786)	611	(486)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	77	(2,713)	(1,549)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, after Tax	(9,241)	109	(910)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Reclassification Adjustments, Net of Tax	1,261	(2,713)	(1,549)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(7,980)	(2,604)	(2,459)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax	455	502	424
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(729)	502	424
Other Comprehensive Income (Loss), Net of Tax	(8,709)	(2,102)	(2,035)
Gain (Loss) on Sale of Investments	(1,821)	0	0
Other than Temporary Impairment Losses, Investments	0	0	0
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax	(1,821)	0	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	(637)	0	0
Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ (1,184)	$ 0	$ 0

Earnings Per Common Share - Su

Earnings Per Common Share - Summary of Computation of Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net Income (Loss) Available to Common Stockholders, Basic [Abstract]
Net income	$ 84,242	$ 86,135	$ 81,012
Denominator:
Weighted-average common shares outstanding	15,295,573	15,332,553	15,364,281
Effect of dilutive PBRSUs	94,779	72,607	40,459
Earnings per common share:	15,390,352	15,405,160	15,404,740
Earnings per common share:
Basic earnings per common share	$ 5.51	$ 5.62	$ 5.27
Diluted earnings per common share	$ 5.47	$ 5.59	$ 5.26

Earnings Per Common Share - Na

Earnings Per Common Share - Narrative (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class of Warrant or Right [Line Items]
Weighted Average Number Diluted Shares Outstanding Adjustment	94,779	72,607	40,459
2013 Long Term Incentive Plan [Member]
Class of Warrant or Right [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	45,788	41,550	23,025
Common Shares
Class of Warrant or Right [Line Items]
Treasury Stock, Shares, Acquired	70,000	0	71,700

Dividend Restrictions (Details)

Dividend Restrictions (Details) $ in Millions	Dec. 31, 2017USD ($)
Disclosure of Restrictions on Dividends, Loans and Advances Disclosure [Abstract]
Amount available for dividend distribution without prior approval from regulatory authority	$ 76.1

Financial Instruments With O116

Financial Instruments With Off-Balance Sheet Risk And Financial Instruments With Concentrations Of Credit Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused Commitments to Extend Credit	$ 893,205	$ 912,007
Standby letters of credit	$ 13,421	$ 13,746

Loan Servicing - Narrative (De

Loan Servicing - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Transfers and Servicing of Financial Assets [Abstract]
Serviced sold mortgage loans	$ 1,371,000	$ 1,330,000	$ 1,276,000
Serviced sold mortgage loans with recourse	3,000	4,100	5,400
Mortgage loans sold with recourse, reserve	$ 270	$ 300
Mortgage servicing rights, discount rate	13.00%	13.00%
Servicing fees included in other service income	$ 3,500	$ 3,400	$ 3,400
Minimum
Transfers and Servicing of Financial Assets [Abstract]
Mortgage servicing rights, constant prepayment speeds	6.50%	6.20%
Maximum
Transfers and Servicing of Financial Assets [Abstract]
Mortgage servicing rights, constant prepayment speeds	17.10%	16.80%
Mortgages [Member]
Servicing Assets at Fair Value [Line Items]
Servicing Asset at Amortized Cost, Fair Value	$ 9,692	$ 9,299

Loan Servicing - Activity for

Loan Servicing - Activity for MSRs And Related Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
MSRs:
Carrying amount, net, beginning of year	$ 9,266	$ 9,008	$ 8,613
Additions	1,941	2,286	1,748
Amortization	(1,624)	(1,835)	(1,637)
Change in valuation allowance	105	(193)	284
Carrying amount, net, end of year	9,688	9,266	9,008
Valuation allowance:
Beginning of year	735	542	826
Change in valuation allowance	(105)	193	(284)
End of year	$ 630	$ 735	$ 542

Fair Value - Narrative (Detail

Fair Value - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount percentage applied to real estate appraised values	15.00%
Discount percentage applied to lot development appraised values	6.00%
Partial charge-offs on impaired loans	$ 10,040	$ 24,943
Allowance for loans individually evaluated for impairment	684	548
Book Value Of Impaired Loans Carried At Fair Value	3,577	6,379
Impaired loans carried at fair value	3,574	5,983
Impaired Financing Receivable, Related Allowance	684	548
Impaired Financing Receivable, carried at fair value, related expense	(1,600)	900	$ (2,100)
MSR recorded at lower of cost or fair value	9,688	9,266	9,008	$ 8,613
Servicing Asset at Fair Value, Amount	7,300	6,800
Valuation allowance of MSR	630	735	542	$ 826
MSRs recorded at cost	2,400	2,500
Valuation allowance for impairment of recognized servicing assets, provisions (recoveries)	105	(193)	284
Other Real Estate, Foreclosed Assets, and Repossessed Assets	$ 14,190	$ 13,926
Percent of OREO held at fair value	46.00%	50.00%
Estimated fair value of other real estate owned (OREO)	$ 6,500	$ 6,900
OREO devaluations	458	601	$ 1,592
Commercial Receivables, excluding Commercial, Financial, and Agricultural [Domain]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Financing Receivable, Related Allowance	$ 3	$ 396

Fair Value - Assets and Liabil

Fair Value - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage Loans Held for Sale	$ 4,148	$ 10,413
Mortgage IRLCs	94	124
Level 1
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage IRLCs	0	0
Level 2
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage Loans Held for Sale	4,148	10,413
Mortgage IRLCs	94	124
Level 3
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage IRLCs	0	0
Fair value swap
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swaps, fair value	226	226
Fair value swap | Level 3
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swaps, fair value	226	226
Recurring basis
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage Loans Held for Sale	4,148	10,413
Mortgage IRLCs	94	124
Recurring basis | Level 2
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage Loans Held for Sale	4,148	10,413
Mortgage IRLCs	94	124
Recurring basis | Obligations of U.S. Treasury and other U.S. Government sponsored entities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment Securities	242,720	267,533
Recurring basis | Obligations of U.S. Treasury and other U.S. Government sponsored entities | Level 2
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment Securities	242,720	267,533
Recurring basis | U.S. Government Sponsored Entities’ Asset-Backed Securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment Securities	849,161	987,172
Recurring basis | U.S. Government Sponsored Entities’ Asset-Backed Securities | Level 2
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment Securities	849,161	987,172
Recurring basis | Equity securities
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment Securities	1,935	3,434
Recurring basis | Equity securities | Level 1
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment Securities	1,518	2,644
Recurring basis | Equity securities | Level 3
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment Securities	417	790
Recurring basis | Fair value swap
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swaps, fair value	226	226
Recurring basis | Fair value swap | Level 3
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swaps, fair value	$ 226	$ 226

Fair Value - Reconciliation of

Fair Value - Reconciliation of the Level 3 Inputs for Financial Instruments Measured on a Recurring Basis (Details) - Recurring basis - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	$ (346)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	790	$ 769
Total Gains (Losses)
Included in other comprehensive income	6	21
Purchases, sales, issuances and settlements, other, net	(33)
Ending balance	417	790
Fair Value Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3	0
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	(226)	(226)
Total Gains (Losses)
Purchases, sales, issuances and settlements, other, net	0
Ending Balance	$ (226)	$ (226)

Fair Value - Assets and Lia122

Fair Value - Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Impaired loans carried at fair value	$ 3,574	$ 5,983
MSRs	7,300	6,800
Other loans, net	5,247,021	5,161,919
Level 3
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Impaired loans carried at fair value	3,574	5,983
Other loans, net	5,247,021	5,161,919
Nonrecurring basis
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Impaired loans carried at fair value	3,574	5,983
MSRs	7,316	6,769
Other loans, net	6,520	6,897
Nonrecurring basis | Level 1
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Other loans, net	0	0
Nonrecurring basis | Level 2
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
MSRs	7,316	6,769
Other loans, net	0	0
Nonrecurring basis | Level 3
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Impaired loans carried at fair value	3,574	5,983
Other loans, net	6,520	6,897
Nonrecurring basis | Commercial real estate
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Impaired loans carried at fair value	2,735	3,057
Other loans, net	2,295	2,644
Nonrecurring basis | Commercial real estate | Level 1
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Other loans, net	0	0
Nonrecurring basis | Commercial real estate | Level 2
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Other loans, net	0	0
Nonrecurring basis | Commercial real estate | Level 3
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Impaired loans carried at fair value	2,735	3,057
Other loans, net	2,295	2,644
Nonrecurring basis | Construction real estate
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Other loans, net	3,204	3,322
Nonrecurring basis | Construction real estate | Level 1
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Other loans, net	0	0
Nonrecurring basis | Construction real estate | Level 2
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Other loans, net	0	0
Nonrecurring basis | Construction real estate | Level 3
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Other loans, net	3,204	3,322
Nonrecurring basis | Commercial
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Impaired loans carried at fair value	127	541
Nonrecurring basis | Commercial | Level 3
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Impaired loans carried at fair value	127	541
Nonrecurring basis | Residential real estate
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Impaired loans carried at fair value	712	2,385
Other loans, net	1,021	931
Nonrecurring basis | Residential real estate | Level 1
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Other loans, net	0	0
Nonrecurring basis | Residential real estate | Level 2
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Other loans, net	0	0
Nonrecurring basis | Residential real estate | Level 3
Fair Value, Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Impaired loans carried at fair value	712	2,385
Other loans, net	$ 1,021	$ 931

Fair Value - Qualitative Infor

Fair Value - Qualitative Information About Level 3 Fair Value Measurements for Financial Instruments Measured at Fair Value on a Non-recurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	$ 3,574	$ 5,983
Other real estate owned	5,247,021	5,161,919
Nonrecurring basis
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	3,574	5,983
Other real estate owned	6,520	6,897
Commercial real estate | Nonrecurring basis
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	2,735	3,057
Other real estate owned	2,295	2,644
Commercial real estate | Nonrecurring basis | Loans receivable
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	2,735	3,057
Construction real estate | Nonrecurring basis
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other real estate owned	3,204	3,322
Commercial | Nonrecurring basis
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	127	541
Commercial | Nonrecurring basis | Loans receivable
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	127	541
Residential real estate | Nonrecurring basis
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	712	2,385
Other real estate owned	1,021	931
Residential real estate | Nonrecurring basis | Loans receivable
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	712	2,385
Commercial real estate | Nonrecurring basis | Other real estate owned
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other real estate owned	2,295	2,644
Construction real estate | Nonrecurring basis | Other real estate owned
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other real estate owned	3,204	3,322
Residential Real Estate | Nonrecurring basis | Other real estate owned
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other real estate owned	$ 1,021	$ 931
Sales comparison approach | Commercial real estate | Low | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Adj to comparables	0.00%	0.00%
Sales comparison approach | Commercial real estate | High | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Adj to comparables	90.00%	90.00%
Sales comparison approach | Commercial real estate | Weighted Average [Member] | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Adj to comparables	22.70%	20.20%
Sales comparison approach | Commercial | Low | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Adj to comparables	0.00%	0.00%
Sales comparison approach | Commercial | High | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Adj to comparables	4.80%	11.10%
Sales comparison approach | Commercial | Weighted Average [Member] | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Adj to comparables	2.40%	1.60%
Sales comparison approach | Residential real estate | Low | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Adj to comparables	0.00%	0.30%
Sales comparison approach | Residential real estate | High | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Adj to comparables	33.00%	110.00%
Sales comparison approach | Residential real estate | Weighted Average [Member] | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Adj to comparables	12.50%	17.00%
Sales comparison approach | Commercial real estate | Low | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Adj to comparables	0.00%	0.00%
Sales comparison approach | Commercial real estate | High | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Adj to comparables	68.40%	68.40%
Sales comparison approach | Commercial real estate | Weighted Average [Member] | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Adj to comparables	34.70%	26.50%
Sales comparison approach | Construction real estate | Low | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Adj to comparables	0.00%	0.00%
Sales comparison approach | Construction real estate | High | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Adj to comparables	90.00%	90.00%
Sales comparison approach | Construction real estate | Weighted Average [Member] | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Adj to comparables	24.50%	24.70%
Sales comparison approach | Residential Real Estate | Low | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Adj to comparables	1.20%	3.20%
Sales comparison approach | Residential Real Estate | High | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Adj to comparables	79.70%	79.70%
Sales comparison approach | Residential Real Estate | Weighted Average [Member] | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Adj to comparables	31.80%	30.60%
Income approach | Commercial real estate | Low | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Capitalization rate	9.00%	9.00%
Income approach | Commercial real estate | High | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Capitalization rate	11.00%	10.60%
Income approach | Commercial real estate | Weighted Average [Member] | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Capitalization rate	9.90%	10.10%
Income approach | Residential real estate | Low | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Capitalization rate	10.50%	10.00%
Income approach | Residential real estate | High | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Capitalization rate	10.50%	10.00%
Income approach | Residential real estate | Weighted Average [Member] | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Capitalization rate	10.50%	10.00%
Income approach | Commercial real estate | Low | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Capitalization rate	13.00%	13.00%
Income approach | Commercial real estate | High | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Capitalization rate	13.00%	14.00%
Income approach | Commercial real estate | Weighted Average [Member] | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Capitalization rate	13.00%	13.10%
Cost approach | Commercial real estate | Low | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Fair Value Inputs, Accumulated Depreciation	90.10%	17.00%
Cost approach | Commercial real estate | High | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Fair Value Inputs, Accumulated Depreciation	90.10%	18.00%
Cost approach | Commercial real estate | Weighted Average [Member] | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Fair Value Inputs, Accumulated Depreciation	90.10%	17.80%
Bulk sale approach | Commercial | Low | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Discount rate		10.00%
Bulk sale approach | Commercial | High | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Discount rate		10.00%
Bulk sale approach | Commercial | Weighted Average [Member] | Nonrecurring basis | Loans receivable
Fair Value Inputs [Abstract]
Discount rate		10.00%
Bulk sale approach | Construction real estate | Low | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Discount rate	15.00%	15.00%
Bulk sale approach | Construction real estate | High | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Discount rate	15.00%	15.00%
Bulk sale approach | Construction real estate | Weighted Average [Member] | Nonrecurring basis | Other real estate owned
Fair Value Inputs [Abstract]
Discount rate	15.00%	15.00%

Fair Value - Fair Value of Fin

Fair Value - Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financial assets:
Cash and money market instruments	$ 169,112	$ 146,466
Investment securities (1)	1,457,595	1,514,811
Mortgage loans held for sale	4,148	10,413
Impaired loans carried at fair value	3,574	5,983
Derivative Asset	94	124
Other loans, net	5,247,021	5,161,919
Loans receivable, net	5,254,837	5,178,439
Financial liabilities:
Noninterest bearing checking accounts	1,633,941	1,523,417
Interest bearing transaction accounts	1,260,095	1,174,448
Savings accounts	1,888,545	1,704,920
Time Deposits, Fair Value	1,035,093	1,122,598
Other	1,269	1,301
Total deposits	5,818,943	5,526,684
Short-term borrowings	391,289	394,795
Long-term debt	504,503	712,958
Subordinated debentures/notes	13,370	40,903
Fair value swap
Derivative financial instruments:
Swaps, fair value	226	226
Level 1
Financial assets:
Cash and money market instruments	169,112	146,466
Investment securities (1)	1,518	2,644
Derivative Asset	0	0
Loans receivable, net	0	0
Financial liabilities:
Noninterest bearing checking accounts	1,633,941	1,523,417
Interest bearing transaction accounts	1,260,095	1,174,448
Savings accounts	1,888,545	1,704,920
Other	1,269	1,301
Total deposits	4,783,850	4,404,086
Level 2
Financial assets:
Investment securities (1)	1,455,660	1,511,377
Mortgage loans held for sale	4,148	10,413
Derivative Asset	94	124
Loans receivable, net	4,242	10,537
Financial liabilities:
Time Deposits, Fair Value	1,035,093	1,122,598
Total deposits	1,035,093	1,122,598
Short-term borrowings	391,289	394,795
Long-term debt	504,503	712,958
Subordinated debentures/notes	13,370	40,903
Level 3
Financial assets:
Investment securities (1)	417	790
Impaired loans carried at fair value	3,574	5,983
Derivative Asset	0	0
Other loans, net	5,247,021	5,161,919
Loans receivable, net	5,250,595	5,167,902
Financial liabilities:
Total deposits	0	0
Level 3 | Fair value swap
Derivative financial instruments:
Swaps, fair value	226	226
Available-for-sale Securities [Member]
Financial assets:
Accrued interest receivable	5,505	3,849
Available-for-sale Securities [Member] | Level 2
Financial assets:
Accrued interest receivable	5,505	3,849
Loans
Financial assets:
Accrued interest receivable	16,659	14,973
Loans | Level 3
Financial assets:
Accrued interest receivable	16,659	14,973
Deposits
Financial liabilities:
Accrued interest payable	1,211	900
Deposits | Level 1
Financial liabilities:
Accrued interest payable	77	82
Deposits | Level 2
Financial liabilities:
Accrued interest payable	1,134	818
Borrowings
Financial liabilities:
Accrued interest payable	1,067	1,251
Borrowings | Level 1
Financial liabilities:
Accrued interest payable	11	1
Borrowings | Level 2
Financial liabilities:
Accrued interest payable	1,056	1,250
Reported Value Measurement [Member]
Financial assets:
Cash and money market instruments	169,112	146,466
Investment securities (1)	1,451,013	1,517,972
Mortgage loans held for sale	4,148	10,413
Impaired loans carried at fair value	3,574	5,983
Derivative Asset	94	124
Other loans, net	5,314,679	5,204,713
Loans receivable, net	5,322,495	5,221,233
Financial liabilities:
Noninterest bearing checking accounts	1,633,941	1,523,417
Interest bearing transaction accounts	1,260,095	1,174,448
Savings accounts	1,888,545	1,704,920
Time Deposits, Fair Value	1,033,476	1,117,870
Other	1,269	1,301
Total deposits	5,817,326	5,521,956
Short-term borrowings	391,289	394,795
Long-term debt	500,000	694,281
Subordinated debentures/notes	15,000	45,000
Reported Value Measurement [Member] | Fair value swap
Derivative financial instruments:
Swaps, fair value	226	226
Reported Value Measurement [Member] | Available-for-sale Securities [Member]
Financial assets:
Accrued interest receivable	5,505	3,849
Reported Value Measurement [Member] | Loans
Financial assets:
Accrued interest receivable	16,659	14,973
Reported Value Measurement [Member] | Deposits
Financial liabilities:
Accrued interest payable	1,211	900
Reported Value Measurement [Member] | Borrowings
Financial liabilities:
Accrued interest payable	$ 1,067	$ 1,251

Fair Value Schedule of Impaired

Fair Value Schedule of Impaired Financing Receivables (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Book Value Of Impaired Loans Carried At Fair Value	$ 3,577	$ 6,379
Partial Charge-Offs On Impaired Loans carried at Fair Value	2,780	3,681
Impaired Financing Receivable, Related Allowance	684	548
Impaired loans carried at fair value	3,574	5,983
Impaired Financing Receivable, loans not held at Fair Value, Recorded Investment	52,987	64,047
Partial Charge-offs on Impaired Loans carried at Cost	7,260	21,262
impaired Financing Receivable, loans not held at Fair Value, Carrying Amount	52,306	63,895
Recorded investment	56,564	70,426	$ 80,664
Partial charge-offs on impaired loans	10,040	24,943
Individually evaluated for impairment	684	548
Impaired Financing Receivable, Carrying Value	55,880	69,878
Financing Receivable, not collateral dependent [Domain]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Related Allowance	681	152
Commercial Receivables, excluding Commercial, Financial, and Agricultural [Domain]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Related Allowance	$ 3	$ 396

Capital Ratios - Capital Ratio

Capital Ratios - Capital Ratios for Park and Each Subsidiary (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital Conservation Buffer	1.25%	0.625%
Park National Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Risk-Based Capital	10.35%	9.87%
Tier One Risk Based Capital Required for Capital Adequacy	$ 325,054	$ 324,115
Common Equity Tier 1	10.35%	9.87%
Common Equity Tier One Capital Required for Capital Adequacy	$ 243,791	$ 243,086
Total Risk-Based	11.60%	11.24%
Capital Required for Capital Adequacy	$ 433,406	$ 432,153
Leverage Capital Required For Capital Adequacy To Average Total Assets	4.00%	4.00%
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	6.00%
Tier One Risk Based Capital Required to be Well Capitalized	$ 433,406	$ 432,153
Common Equity Tier 1 Capital Required For Capital Adequacy To Average Total Assets	4.50%	4.50%
Common Equity Tier One Capital Required to be Well-Capitalized	$ 352,142	$ 351,125
Leverage	7.36%	7.34%
Tier One Leverage Capital Required for Capital Adequacy	$ 304,722	$ 290,671
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Capital Required to be Well Capitalized	$ 541,757	$ 540,192
Tier One Risk Based Capital	$ 560,530	$ 533,215
Common Equity Tier 1 Capital Required To Be Well Capitalized To Average Total Assets	6.50%	6.50%
Common Equity Tier One Capital	$ 560,530	$ 533,215
Risk Based Capital	$ 628,440	$ 607,269
Leverage Capital Required To Be Well Capitalized To Average Total Assets	5.00%	5.00%
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	8.00%	8.00%
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00%	10.00%
Tier One Leverage Capital	$ 560,530	$ 533,215
Tier One Leverage Capital Required to be Well Capitalized	$ 380,903	$ 363,339
Park
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Risk-Based Capital	13.22%	12.83%
Tier One Risk Based Capital Required for Capital Adequacy	$ 329,235	$ 328,673
Common Equity Tier 1	12.94%	12.55%
Common Equity Tier One Capital Required for Capital Adequacy	$ 246,927	$ 246,505
Total Risk-Based	14.14%	14.32%
Capital Required for Capital Adequacy	$ 438,981	$ 438,231
Leverage Capital Required For Capital Adequacy To Average Total Assets	4.00%	4.00%
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	6.00%
Tier One Risk Based Capital Required to be Well Capitalized	$ 329,235	$ 328,673
Common Equity Tier 1 Capital Required For Capital Adequacy To Average Total Assets	4.50%	4.50%
Leverage	9.44%	9.56%
Tier One Leverage Capital Required for Capital Adequacy	$ 307,441	$ 293,916
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Capital Required to be Well Capitalized	$ 548,726	$ 547,789
Leverage Capital Required For Capital Adequacy plus capital conservation buffer To Average Total Assets	4.00%	4.00%
Tier One Risk Based Capital Required For Capital Adequacy plus capital conservation buffer To Average Total Assets	8.50%	8.50%
Common Equity Tier 1 Capital Required For Capital Adequacy plus capital conservation buffer To Average Total Assets	7.00%	7.00%
Capital Required For Capital Adequacy plus capital conservation buffer To Average Total Assets	10.50%	10.50%
Tier One Risk Based Capital	$ 725,221	$ 702,651
Common Equity Tier One Capital	710,221	687,651
Risk Based Capital	$ 775,867	$ 784,406
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	6.00%	6.00%
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00%	10.00%
Tier One Leverage Capital	$ 725,221	$ 702,651
Minimum
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital Conservation Buffer	0.00%
Maximum
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital Conservation Buffer	2.50%

Segment Information - Schedule

Segment Information - Schedule of Operating Results by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net interest income (loss)	$ 243,759	$ 238,086	$ 227,632
Provision for (recovery of) loan losses	8,557	(5,101)	4,990
Other income (loss)	80,635	78,731	77,551
Gain (Loss) on Sale of Investments	1,821	0	0
Other Noninterest Expense	188,724	190,627	179,267
Depreciation, Amortization and Accretion, Net	8,644	8,396	7,347
Other expense	197,368	199,023	186,614
Income (loss) before taxes	118,469	122,895	113,579
Income taxes (benefit)	34,227	36,760	32,567
Net income	84,242	86,135	81,012
Assets	7,537,620	7,467,586	7,311,354
Loans	5,372,483	5,271,857	5,068,085
Total deposits	5,817,326	5,521,956	5,347,642
Totals For Reportable Segments [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	243,171	238,224	227,393
Other Noninterest Expense	179,919	180,896	169,295
Depreciation, Amortization and Accretion, Net	8,644	8,396	7,347
Income taxes (benefit)	36,922	41,117	37,238
Assets	7,524,830	7,447,148	7,299,098
Total deposits	5,900,125	5,634,008	5,451,920
PNB
Segment Reporting Information [Line Items]
Net interest income (loss)	235,243	227,576	220,879
Provision for (recovery of) loan losses	9,898	2,611	7,665
Other income (loss)	77,126	74,803	75,188
Other expense	180,275	177,562	167,476
Income (loss) before taxes	122,196	122,206	120,926
Income taxes (benefit)	34,881	37,755	36,581
Net income	87,315	84,451	84,345
Assets	7,467,851	7,389,538	7,229,764
Loans	5,339,255	5,234,828	5,029,072
Total deposits	5,896,676	5,630,199	5,447,293
GFSC
Segment Reporting Information [Line Items]
Net interest income (loss)	5,839	5,874	6,588
Provision for (recovery of) loan losses	1,917	1,887	1,415
Other income (loss)	40	(1)	2
Other expense	3,036	4,457	2,984
Income (loss) before taxes	926	(471)	2,191
Income taxes (benefit)	666	(164)	768
Net income	260	(307)	1,423
Assets	32,077	32,268	35,793
Loans	33,385	32,661	35,469
Total deposits	3,449	3,809	4,627
SEPH
Segment Reporting Information [Line Items]
Net interest income (loss)	2,089	4,774	(74)
Provision for (recovery of) loan losses	(3,258)	(9,599)	(4,090)
Other income (loss)	404	2,974	1,848
Other expense	5,252	7,273	6,182
Income (loss) before taxes	499	10,074	(318)
Income taxes (benefit)	1,375	3,526	(111)
Net income	(876)	6,548	(207)
Assets	24,902	25,342	33,541
Loans	10,891	12,354	15,153
Total deposits	0	0	0
All Other
Segment Reporting Information [Line Items]
Net interest income (loss)	588	(138)	239
Provision for (recovery of) loan losses	0	0	0
Other income (loss)	3,065	955	513
Other expense	8,805	9,731	9,972
Income (loss) before taxes	(5,152)	(8,914)	(9,220)
Income taxes (benefit)	(2,695)	(4,357)	(4,671)
Net income	(2,457)	(4,557)	(4,549)
Assets	12,790	20,438	12,256
Loans	(11,048)	(7,986)	(11,609)
Total deposits	(82,799)	(112,052)	(104,278)
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	1,500	2,164	2,561
Other Noninterest Expense	0	0	0
Depreciation, Amortization and Accretion, Net	0	0	0
Income taxes (benefit)	0	0	0
Assets	(14,679)	(9,204)	(13,557)
Total deposits	(82,799)	(112,052)	(104,278)
Parent Co Gfsc Totals Not Eliminated [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	(912)	(2,302)	(2,322)
Other Noninterest Expense	8,805	9,731	9,972
Depreciation, Amortization and Accretion, Net	0	0	0
Income taxes (benefit)	(2,695)	(4,357)	(4,671)
Assets	27,469	29,642	25,813
Total deposits	$ 0	$ 0	$ 0

Parent Company Statements - Na

Parent Company Statements - Narrative (Details) - Parent Company - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income taxes	$ 3,300	$ 4,400	$ 4,130
Undistributed earnings, restricted from transfer as dividends	$ 282,600	$ 259,700

Parent Company Statements - Ba

Parent Company Statements - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets:
Other assets	$ 533,189	$ 520,124
Total assets	7,537,620	7,467,586	$ 7,311,354
Liabilities:
Subordinated notes	15,000	45,000
Other liabilities	57,904	69,314
Total liabilities	6,781,519	6,725,346
Total liabilities and shareholders’ equity	7,537,620	7,467,586
Parent Company
Assets:
Cash	79,452	112,067	$ 102,416	$ 98,671
Investment in subsidiaries	645,287	626,569
Debentures receivable from PNB	25,000	25,000
Other investments	1,398	2,962
Other assets	26,838	26,651
Total assets	777,975	793,249
Liabilities:
Subordinated notes	15,000	45,000
Other liabilities	6,874	6,009
Total liabilities	21,874	51,009
Total shareholders’ equity	756,101	742,240
Total liabilities and shareholders’ equity	$ 777,975	$ 793,249

Parent Company Statements - St

Parent Company Statements - Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income:
Interest and dividends	$ 286,424	$ 276,258	$ 265,074
Gain (Loss) on Sale of Investments	1,821	0	0
Interest Expense	42,665	38,172	37,442
Expense:
Federal income tax benefit	(34,227)	(36,760)	(32,567)
Net income	84,242	86,135	81,012
Other Comprehensive Income (Loss), Net of Tax	(8,709)	(2,102)	(2,035)
Parent Company
Income:
Dividends from subsidiaries	60,000	60,000	60,000
Interest and dividends	1,500	2,164	2,561
Gain (Loss) on Sale of Investments	1,821	0	0
Other	1,405	1,081	560
Total income	64,726	63,245	63,121
Interest Expense	1,073	2,429	2,369
Expense:
Other, net	8,805	9,730	9,972
Total expense	9,878	12,159	12,341
Income before federal taxes and equity in undistributed income of subsidiaries	54,848	51,086	50,780
Federal income tax benefit	2,695	4,357	4,671
Income before equity in undistributed income of subsidiaries	57,543	55,443	55,451
Equity in undistributed income of subsidiaries	26,699	30,692	25,561
Net income	84,242	86,135	81,012
Other Comprehensive Income (Loss), Net of Tax	(8,709)	(2,102)	(2,035)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 75,533	$ 84,033	$ 78,977

Parent Company Statements -131

Parent Company Statements - Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	$ 84,242	$ 86,135	$ 81,012
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation expense	3,942	2,814	1,828
Increase (decrease) in other liabilities	(11,778)	2,006	1,173
Net cash provided by operating activities	87,991	87,887	89,234
Investing activities:
Net cash used in investing activities	(61,971)	(152,560)	(395,468)
Financing activities
Repayment of subordinated notes	(30,000)	0	0
Payments Related to Tax Withholding for Share-based Compensation	347	0	0
Net cash (used in) provided by financing activities	(3,354)	61,660	217,994
Increase (decrease) in cash and cash equivalents	22,666	(3,013)	(88,240)
Parent Company
Net income	84,242	86,135	81,012
Adjustments to reconcile net income to net cash provided by operating activities:
Undistributed income of subsidiaries	(26,699)	(30,692)	(25,561)
Decrease (increase) in other assets	205	(3,425)	(182)
Increase (decrease) in other liabilities	475	(2,524)	485
Net cash provided by operating activities	60,344	52,308	57,582
Proceeds from Sale of Available-for-sale Securities, Equity	2,265	0	0
Investing activities:
Repayment of investments in and advances to subsidiaries	0	15,000	10,000
Net cash used in investing activities	2,265	15,000	10,000
Financing activities
Cash dividends paid	(57,493)	(57,653)	(57,776)
Cash payment for fractional shares	(6)	(4)	(3)
Payments Related to Tax Withholding for Share-based Compensation	(347)	0	0
Net cash (used in) provided by financing activities	(95,224)	(57,657)	(63,837)
Increase (decrease) in cash and cash equivalents	(32,615)	9,651	3,745
Cash at beginning of year	112,067	102,416	98,671
Cash at end of year	79,452	112,067	102,416
Parent Company
Adjustments to reconcile net income to net cash provided by operating activities:
Compensation expense for issuance of treasury shares to directors	1,241	950	963
Share-based compensation expense	2,701	1,864	865
Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments	(1,821)	0	0
Treasury Stock, Common [Member]
Financing activities
Payments for Repurchase of Equity	$ 7,378	$ 0	$ 6,058

Subsequent Event (Details)

Subsequent Event (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Common Stock, Par or Stated Value Per Share		$ 0.25
Subsequent Event [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Asset, Current	$ 4,170,000
Subsequent Event [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 1.08
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	0.01023