Washington Trust Bancorp (WASH) 10-K 26 Feb 19 2018 Q4 Annual report Financial data

DOCUMENT AND ENTITY INFORMATION

DOCUMENT AND ENTITY INFORMATION - USD ($)	12 Months Ended
	Dec. 31, 2018	Jan. 31, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Washington Trust Bancorp Inc
Entity Central Index Key	737,468
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q4
Amendment Flag	false
Entity Common Stock, Shares Outstanding		17,302,047
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 868,380,894

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Assets:
Cash and due from banks		$ 89,923	$ 79,853
Short-term investments		3,552	3,070
Mortgage loans held for sale, at fair value		20,996	26,943
Securities:
Available for sale, at fair value		927,810	780,954
Held to maturity, at amortized cost (fair value $10,316 in 2018 and $12,721 in 2017)		10,415	12,541
Total securities		938,225	793,495
Federal Home Loan Bank stock, at cost		46,068	40,517
Loans:
Total loans	[1]	3,680,360	3,374,071
Less allowance for loan losses		27,072	26,488
Net loans		3,653,288	3,347,583
Premises and equipment, net		29,005	28,333
Investment in bank-owned life insurance		80,463	73,267
Goodwill		63,909	63,909
Identifiable intangible assets, net		8,162	9,140
Other assets		77,175	63,740
Total assets		5,010,766	4,529,850
Liabilities:
Noninterest-bearing deposits		603,216	578,410
Interest-bearing deposits		2,920,832	2,664,297
Total deposits		3,524,048	3,242,707
Federal Home Loan Bank advances		950,722	791,356
Junior subordinated debentures		22,681	22,681
Other liabilities		65,131	59,822
Total liabilities		4,562,582	4,116,566
Commitments and contingencies (Note 22)
Shareholders’ Equity:
Common stock of $.0625 par value; authorized 60,000,000 shares; issued and outstanding 17,302,037 shares in 2018 and 17,226,508 shares in 2017		1,081	1,077
Paid-in capital		119,888	117,961
Retained earnings		355,524	317,756
Accumulated other comprehensive loss		(28,309)	(23,510)
Total shareholders’ equity		448,184	413,284
Total liabilities and shareholders’ equity		$ 5,010,766	$ 4,529,850
[1]	Includes net unamortized loan origination costs of $4.7 million and $3.8 million, respectively, at December 31, 2018 and 2017 and net unamortized premiums on purchased loans of $703 thousand and $878 thousand, respectively, at December 31, 2018 and 2017.

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Mortgage loans held for sale, fair value	$ 20,996	$ 26,943
Securities held to maturity, fair value	$ 10,316	$ 12,721
Common stock, par value (in dollars per share)	$ 0.0625	$ 0.0625
Common stock, shares authorized (in shares)	60,000,000	60,000,000
Common stock, shares issued (in shares)	17,302,037	17,226,508
Common stock, shares outstanding (in shares)	17,302,037	17,226,508

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest income:
Interest and fees on loans	$ 149,932	$ 126,940	$ 118,198
Interest on mortgage loans held for sale	1,212	1,022	1,293
Taxable interest on securities	21,816	18,927	11,584
Nontaxable interest on securities	61	249	982
Dividends on Federal Home Loan Bank stock	2,369	1,774	1,091
Other interest income	1,017	674	322
Total interest and dividend income	176,407	149,586	133,470
Interest expense:
Deposits	24,175	15,064	12,504
Federal Home Loan Bank advances	19,073	14,377	9,992
Junior subordinated debentures	869	613	491
Other interest expense	0	1	5
Total interest expense	44,117	30,055	22,992
Net interest income	132,290	119,531	110,478
Provision for loan losses	1,550	2,600	5,650
Net interest income after provision for loan losses	130,740	116,931	104,828
Noninterest income:
Wealth management revenues	38,341	39,346	37,569
Mortgage banking revenues	10,381	11,392	13,183
Card interchange fees	3,768	3,502	3,385
Service charges on deposit accounts	3,628	3,672	3,702
Loan related derivative income	2,461	3,214	3,243
Income from bank-owned life insurance	2,196	2,161	2,659
Other income	1,339	1,522	1,388
Total noninterest income	62,114	64,809	65,129
Noninterest expense:
Salaries and employee benefits	69,277	68,891	67,795
Outsourced services	8,684	6,920	5,222
Net occupancy	7,891	7,521	7,151
Equipment	4,312	5,358	6,208
Legal, audit and professional fees	2,427	2,294	2,579
FDIC deposit insurance costs	1,612	1,647	1,878
Advertising and promotion	1,406	1,481	1,458
Amortization of intangibles	979	1,035	1,284
Debt prepayment penalties	0	0	431
Change in fair value of contingent consideration	(187)	(643)	(898)
Other expenses	9,761	9,596	7,995
Total noninterest expense	106,162	104,100	101,103
Income before income taxes	86,692	77,640	68,854
Income tax expense	18,260	31,715	22,373
Net income	68,432	45,925	46,481
Net income available to common shareholders	$ 68,288	$ 45,817	$ 46,384
Weighted average common shares outstanding - basic	17,272	17,207	17,081
Weighted average common shares outstanding - diluted	17,391	17,338	17,208
Per share information:
Basic earnings per common share (in dollars per share)	$ 3.95	$ 2.66	$ 2.72
Diluted earnings per common share (in dollars per share)	3.93	2.64	2.70
Cash dividends declared per share (in dollars per share)	$ 1.76	$ 1.54	$ 1.46

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 68,432	$ 45,925	$ 46,481
Other comprehensive (loss) income, net of tax:
Net change in fair value of securities available for sale	(9,228)	621	(7,876)
Net change in fair value of cash flow hedges	619	(52)	(257)
Net change in defined benefit pension plan obligations	3,810	(97)	(1,925)
Total other comprehensive (loss) income, net of tax	(4,799)	472	(10,058)
Total comprehensive income	$ 63,633	$ 46,397	$ 36,423

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Common stock, shares outstanding, beginning balance at Dec. 31, 2015		17,020,000
Stockholders' equity, beginning balance at Dec. 31, 2015	$ 375,388	$ 1,064	$ 110,949	$ 273,074	$ (9,699)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	46,481			46,481
Total other comprehensive income (loss), net of tax	(10,058)				(10,058)
Cash dividends declared	(25,190)			(25,190)
Share-based compensation	2,190		2,190
Exercise of stock options, issuance of other compensation-related equity awards and related tax benefit, net of awards surrendered, shares		151,000
Exercise of stock options, issuance of other compensation related equity awards and related tax benefit, net of awards surrendered	1,993	$ 9	1,984
Common stock, shares outstanding, ending balance at Dec. 31, 2016		17,171,000
Stockholders' equity, ending balance at Dec. 31, 2016	390,804	$ 1,073	115,123	294,365	(19,757)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	45,925			45,925
Total other comprehensive income (loss), net of tax	472				472
Cash dividends declared	(26,759)			(26,759)
Share-based compensation	2,577		2,577
Exercise of stock options, issuance of other compensation-related equity awards, net of awards surrendered, shares		56,000
Exercise of stock options, issuance of other compensation-related equity awards, net of awards surrendered	265	$ 4	261
Reclassification of income tax effects due to the adoption of ASU 2018-02	$ 0			4,225	(4,225)
Common stock, shares outstanding, ending balance at Dec. 31, 2017	17,226,508	17,227,000
Stockholders' equity, ending balance at Dec. 31, 2017	$ 413,284	$ 1,077	117,961	317,756	(23,510)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	68,432			68,432
Total other comprehensive income (loss), net of tax	(4,799)				(4,799)
Cash dividends declared	(30,664)			(30,664)
Share-based compensation	2,602		2,602
Exercise of stock options, issuance of other compensation-related equity awards, net of awards surrendered, shares		75,000
Exercise of stock options, issuance of other compensation-related equity awards, net of awards surrendered	$ (671)	$ 4	(675)
Common stock, shares outstanding, ending balance at Dec. 31, 2018	17,302,037	17,302,000
Stockholders' equity, ending balance at Dec. 31, 2018	$ 448,184	$ 1,081	$ 119,888	$ 355,524	$ (28,309)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 68,432	$ 45,925	$ 46,481
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	1,550	2,600	5,650
Depreciation of premises and equipment	3,282	3,454	3,651
Net amortization of premiums and discounts on securities and loans	2,865	3,426	2,779
Amortization of intangibles	979	1,035	1,284
Goodwill impairment	0	150	0
Share–based compensation	2,602	2,577	2,190
Tax benefit from stock option exercises and other equity awards	496	508	1,016
Deferred income tax (benefit) expense	(63)	5,687	868
Income from bank-owned life insurance	(2,196)	(2,161)	(2,659)
Net gains on loan sales and commissions on loans originated for others, including fair value adjustments	(9,749)	(10,991)	(13,137)
Net gain on sale of portfolio loans	0	0	(135)
Proceeds from sales of loans	391,960	472,556	551,788
Loans originated for sale	(378,896)	(461,262)	(532,950)
Change in fair value of contingent consideration liability	(187)	(643)	(898)
(Increase) decrease in other assets	(7,456)	(8,794)	984
Increase (decrease) in other liabilities	9,257	5,318	(7,163)
Net cash provided by operating activities	82,876	59,385	59,749
Cash flows from investing activities:
Purchases of mortgage-backed securities available for sale	(175,539)	(89,194)	(431,662)
Purchases of other investment securities available for sale	(76,264)	(59,940)	(121,679)
Maturities and principal payments of mortgage-backed securities available for sale	83,197	84,381	65,673
Maturities and principal payments of other investment securities available for sale	7,301	22,071	108,256
Maturities and principal payments of mortgage-backed securities held to maturity	2,029	2,950	4,193
(Purchases) remittance of Federal Home Loan Bank stock	(5,551)	2,612	(18,813)
Net increase in loans	(306,299)	(120,582)	(112,966)
Proceeds from sale of portfolio loans	0	0	510
Purchases of loans	(1,780)	(20,278)	(113,562)
Proceeds from the sale of property acquired through foreclosure or repossession	49	1,053	731
Purchases of premises and equipment	(3,974)	(2,779)	(3,112)
Purchases of bank-owned life insurance	(5,000)	0	(5,000)
Proceeds from bank-owned life insurance	0	0	2,054
Net cash used in investing activities	(481,831)	(179,706)	(625,377)
Cash flows from financing activities:
Net increase in deposits	281,341	178,955	129,497
Proceeds from Federal Home Loan Bank advances	2,040,000	1,352,501	1,428,750
Repayment of Federal Home Loan Bank advances	(1,880,634)	(1,410,075)	(958,793)
Payment of contingent consideration liability	(1,217)	0	0
Proceeds from stock option exercises and issuance of other equity awards, net of awards surrendered	(671)	366	977
Cash dividends paid	(29,312)	(26,300)	(24,637)
Net cash provided by financing activities	409,507	95,447	575,794
Net increase (decrease) in cash and cash equivalents	10,552	(24,874)	10,166
Cash and cash equivalents at beginning of year	82,923	107,797	97,631
Cash and cash equivalents at end of year	93,475	82,923	107,797
Noncash Investing and Financing Activities:
Loans charged-off	1,187	2,462	7,012
Loans transferred to property acquired through foreclosure or repossession	3,074	576	1,075
Supplemental Disclosures:
Interest payments	41,285	29,687	22,267
Income tax payments	$ 17,148	$ 25,988	$ 19,822

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation Washington Trust Bancorp, Inc. (the “Bancorp”) is a publicly-owned registered bank holding company that has elected to be a financial holding company. The Bancorp’s subsidiaries include The Washington Trust Company, of Westerly (the “Bank”), a Rhode Island chartered commercial bank founded in 1800, and Weston Securities Corporation (“WSC”). Through its subsidiaries, the Bancorp offers a complete product line of financial services including commercial, residential and consumer lending, retail and commercial deposit products, and wealth management services through its offices in Rhode Island, eastern Massachusetts and Connecticut. The consolidated financial statements include the accounts of the Bancorp and its subsidiaries (collectively, the “Corporation” or “Washington Trust”). All intercompany balances and transactions have been eliminated in consolidation. Certain previously reported amounts have been reclassified to conform to current year’s presentation. The Bancorp also owns the common stock of two capital trusts, which have issued trust preferred securities. These capital trusts are variable interest entities in which the Bancorp is not the primary beneficiary and, therefore, are not consolidated. The capital trust’s only assets are junior subordinated debentures issued by the Bancorp, which were acquired by the capital trusts using the proceeds from the issuance of the trust preferred securities and common stock. The Bancorp’s equity interest in the capital trusts, classified in other assets, and the junior subordinated debentures are included in the Consolidated Balance Sheets. Interest expense on the junior subordinated debentures is included in the Consolidated Statements of Income. The accounting and reporting policies of the Corporation conform to accounting principles generally accepted in the United States of America (“GAAP”) and to general practices of the banking industry. In preparing the financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheet and revenues and expenses for the period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to change are the determination of the allowance for loan losses, the valuation of goodwill and identifiable intangible assets, the assessment of investment securities for impairment and the accounting for defined benefit pension plans. Short-term Investments Short-term investments consist of highly liquid investments with a maturity date of three months or less when purchased and are considered to be cash equivalents. The Corporation’s short-term investments may be comprised of overnight federal funds sold, securities purchased under resale agreements, money market mutual funds and U.S. Treasury bills. Securities Management determines the appropriate classification of securities at the time of purchase. Investments in debt securities that management has the positive intent and ability to hold to maturity are classified as held to maturity and carried at amortized cost. Investments not classified as held to maturity are classified as available for sale. Securities available for sale consist of debt securities that are available for sale to respond to changes in market interest rates, liquidity needs, changes in funding sources and other similar factors. These assets are specifically identified and are carried at fair value. Changes in fair value of available for sale securities, net of applicable income taxes, are reported as a separate component of shareholders’ equity. Washington Trust does not have a trading portfolio. Premiums and discounts are amortized and accreted over the term of the securities on a method that approximates the level yield method. The amortization and accretion is included in interest income on securities. Interest income is recognized when earned. Realized gains or losses from sales of securities are recorded on the trade date and are determined using the specific identification method. The fair values of securities may be based on either quoted market prices or third party pricing services. When the fair value of an investment security is less than its amortized cost basis, the Corporation assesses whether the decline in value is other-than-temporary. The Corporation considers whether evidence indicating the cost of the investment is recoverable outweighs evidence to the contrary. Evidence considered in this assessment includes the reasons for impairment, the severity and duration of the impairment, changes in the value subsequent to the reporting date, forecasted performance of the issuer, changes in the dividend or interest payment practices of the issuer, changes in the credit rating of the issuer or the specific security, and the general market condition in the geographic area or industry in which the issuer operates. In determining whether an other-than-temporary impairment has occurred for debt securities, the Corporation compares the present value of cash flows expected to be collected from the security with the amortized cost of the security. If the present value of expected cash flows is less than the amortized cost of the security, then the entire amortized cost of the security will not be recovered; that is, a credit loss exists, and an other-than-temporary impairment shall be considered to have occurred. The credit loss component of an other-than-temporary impairment write-down for debt securities is recorded in earnings while the remaining portion of the impairment loss is recognized, net of tax, in other comprehensive income provided that the Corporation does not intend to sell the underlying debt security and it is more-likely-than-not that the Corporation would not have to sell the debt security prior to recovery of the unrealized loss, which may be to maturity. If the Corporation intended to sell any securities with an unrealized loss or it is more-likely-than-not that the Corporation would be required to sell the investment securities before recovery of their amortized cost basis, then the entire unrealized loss would be recorded in earnings. Federal Home Loan Bank Stock The Bank is a member of the FHLB. The FHLB is a cooperative that provides services, including funding in the form of advances, to its member banking institutions. As a requirement of membership, the Bank must own a minimum amount of FHLB stock, calculated periodically based primarily on its level of borrowings from the FHLB. No market exists for shares of FHLB stock and therefore, it is carried at cost. FHLB stock may be redeemed at par value five years following termination of FHLB membership, subject to limitations which may be imposed by the FHLB or its regulator, the Federal Housing Finance Board, to maintain capital adequacy of the FHLB. While the Bank currently has no intentions to terminate its FHLB membership, the ability to redeem its investment in FHLB stock would be subject to the conditions imposed by the FHLB. The Bank monitors its investment to determine if impairment exists. Based on the capital adequacy and the liquidity position of the FHLB, management believes there is no impairment related to the carrying amount of FHLB stock included in the Consolidated Balance Sheet as of December 31, 2018 . Mortgage Banking Activities Mortgage Loans Held for Sale Residential mortgage loans originated and intended for sale in the secondary market are classified as held for sale. Accounting Standards Codification (“ASC”) 825, “Financial Instruments” allows for the irrevocable option to elect fair value accounting for the initial and subsequent measurement for certain financial assets and liabilities on a contract-by-contract basis that may otherwise not be required to be measured at fair value under other accounting standards. The Corporation has elected the fair value option for mortgage loans held for sale in order to better match changes in fair values of the loans with changes in the fair value of the derivative forward sale commitment contracts used to economically hedge them. Changes in the fair value of mortgage loans held for sale accounted for under the fair value option are recorded in earnings and are partially offset by changes in fair value of forward sale commitments. These changes in fair value are included in mortgage banking revenues. Gains and losses on residential loan sales are recognized at the time of sale and included in mortgage banking revenues. Upfront fees and costs related to mortgage loans held for sale for which the fair value option was elected are recognized in mortgage banking revenues as received / incurred and are not deferred. Commissions received on mortgage loans brokered to various investors are recognized when received and included in mortgage banking revenues. Loan Servicing Rights When mortgage loans held for sale are sold with servicing retained, mortgage servicing right assets are recognized as separate assets. Mortgage servicing rights are originally recorded at fair value. Fair value is based on a valuation model that incorporates assumptions that market participants would use in estimating future net servicing income, such as the cost to service, the discount rate, ancillary income, prepayment speeds, and default rates and losses. Mortgage servicing rights are included in other assets. Mortgage servicing rights are amortized as an offset to mortgage banking revenues over the period of estimated net servicing income. They are periodically evaluated for impairment based on their fair value. Impairment is measured on an aggregated basis by stratifying the rights based on homogeneous characteristics such as note rate and loan type. The fair value is estimated based on the present value of expected cash flows, incorporating assumptions for discount rate, prepayment speed and servicing cost. Any impairment is recognized through a valuation allowance and as a reduction to mortgage banking revenues. Loans Portfolio Loans Loans are carried at the principal amount outstanding, adjusted by partial charge-offs and net of unamortized deferred loan origination fees and costs. Interest income is accrued on a level yield basis based upon principal amounts outstanding, except for loans on nonaccrual status. Deferred loan origination fees and costs are amortized as an adjustment to yield over the term of the related loans. For purchased loans, which did not show signs of credit deterioration at the time of purchase, interest income is also accrued on a level yield basis based upon principal amounts outstanding and is then further adjusted by accretion of any discount or amortization of any premium associated with the loans. Nonaccrual Loans Loans, with the exception of certain well-secured loans that are in the process of collection, are placed on nonaccrual status and interest recognition is suspended when such loans are 90 days or more overdue with respect to principal and/or interest, or sooner if considered appropriate by management. Well-secured loans are permitted to remain on accrual status provided that full collection of principal and interest is assured and the loan is in the process of collection. Loans are also placed on nonaccrual status when, in the opinion of management, full collection of principal and interest is doubtful. When loans are placed on nonaccrual status, interest previously accrued but not collected is reversed against current period income. Subsequent interest payments received on nonaccrual loans are applied to the outstanding principal balance of the loan or recognized as interest income depending on management’s assessment of the ultimate collectability of the loan. Loans are removed from nonaccrual status when they have been current as to principal and interest for a period of time, the borrower has demonstrated an ability to comply with repayment terms, and when, in management’s opinion, the loans are considered to be fully collectible. Troubled Debt Restructured Loans Loans are considered to be troubled debt restructurings when the Corporation has granted concessions to a borrower due to the borrower’s financial condition that it otherwise would not have considered. These concessions may include modifications of the terms of the debt such as deferral of payments, extension of maturity, reduction of principal balance, reduction of the stated interest rate other than normal market rate adjustments, or a combination of these concessions. Debt may be bifurcated with separate terms for each tranche of the restructured debt. Restructuring of a loan in lieu of aggressively enforcing the collection of the loan may benefit the Corporation by increasing the ultimate probability of collection. Restructured loans are classified as accruing or non-accruing based on management’s assessment of the collectability of the loan. Loans which are already on nonaccrual status at the time of the restructuring generally remain on nonaccrual status for approximately six months before management considers such loans for return to accruing status. Accruing restructured loans are placed into nonaccrual status if and when the borrower fails to comply with the restructured terms and management deems it unlikely that the borrower will return to a status of compliance in the near term. Troubled debt restructurings are reported as such for at least one year from the date of the restructuring. In years after the restructuring, troubled debt restructured loans are removed from this classification if the restructuring did not involve a below-market rate concession and the loan is not deemed to be impaired based on the terms specified in the restructuring agreement. Impaired Loans Impaired loans are evaluated on an individual basis and include nonaccrual loans and loans restructured in a troubled debt restructuring. Impairment is measured using a discounted cash flow method based upon the loan’s contractual effective interest rate, or at the loan’s observable market price, or if the loan is collateral dependent, at fair value. For collateral dependent loans for which repayment is dependent on the sale of the collateral, management adjusts the fair value for estimated costs to sell. For collateral dependent loans for which repayment is dependent on the operation of the collateral, such as accruing troubled debt restructured loans, estimated costs to sell are not incorporated into the measurement. Allowance for Loan Losses The allowance for loan losses is management’s best estimate of the risk of loss inherent in the loan portfolio as of the balance sheet date. The allowance is increased by provisions charged to earnings and by recoveries of amounts previously charged-off, and is reduced by charge-offs on loans. Loan charge-offs are recognized when management believes the collectability of the principal balance outstanding is unlikely. Full or partial charge-offs on collateral dependent impaired loans are generally recognized when the collateral is deemed to be insufficient to support the carrying value of the loan. The level of the allowance is based on management’s ongoing review of the growth and composition of the loan portfolio, historical loss experience, estimated loss emergence period (the period from the event that triggers the eventual default until the actual loss is recognized with a charge-off), current economic conditions, analysis of asset quality and credit quality levels and trends, the performance of individual loans in relation to contract terms and other pertinent factors. A methodology is used to systematically measure the amount of estimated loan loss exposure inherent in the loan portfolio for the purposes of establishing a sufficient allowance for loan losses. The methodology includes: (1) the identification of loss allocations for individual loans deemed to be impaired and (2) the application of loss allocation factors for non-impaired loans based on historical loss experience and estimated loss emergence period, with adjustments for various exposures that management believes are not adequately represented by historical loss experience. A loan is considered impaired when, based on current information and events, it is probable that the Corporation will not be able to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Loss allocations for loans deemed to be impaired are measured using a discounted cash flow method based upon the loan’s contractual effective interest rate, or at the loan’s observable market price, or, if the loan is collateral dependent, at the fair value of the collateral. For collateral dependent loans for which repayment is dependent on the sale of the collateral, management adjusts the fair value for estimated costs to sell. For collateral dependent loans for which repayment is dependent on the operation of the collateral, such as accruing troubled debt restructured loans, estimated costs to sell are not incorporated into the measurement. Management may also adjust appraised values to reflect estimated market value declines or apply other discounts to appraised values for unobservable factors resulting from its knowledge of circumstances associated with the property. For loans that are collectively evaluated, loss allocation factors are derived by analyzing historical loss experience by loan segment over an established look-back period deemed to be relevant to the inherent risk of loss in the portfolios. Loans are segmented by loan type, collateral type, delinquency status and loan risk rating, where applicable. These loss allocation factors are adjusted to reflect the loss emergence period. These amounts are supplemented by certain qualitative risk factors reflecting management’s view of how losses may vary from those represented by historical loss rates. These qualitative risk factors include: 1) changes in lending policies and procedures, including changes in underwriting standards and collection, charge-off, and recovery practices not considered elsewhere in estimating credit losses; 2) changes in international, national, regional, and local economic and business conditions and developments that affect the collectability of the portfolio, including the condition of various market segments; 3) changes in the nature and volume of the portfolio and in the terms of loans; 4) changes in the experience, ability, and depth of lending management and other relevant staff; 5) changes in the volume and severity of past due loans, the volume of nonaccrual loans, and the volume and severity of adversely classified or rated loans; 6) changes in the quality of the institution’s loan review system; 7) changes in the value of underlying collateral for collateral dependent loans; 8) the existence and effect of any concentrations of credit, and changes in the level of such concentrations; and 9) the effect of other external factors such as legal and regulatory requirements on the level of estimated credit losses in the institution’s existing portfolio. Because the methodology is based upon historical experience and trends, current economic data, as well as management’s judgment, factors may arise that result in different estimations. Adversely different conditions or assumptions could lead to increases in the allowance. In addition, various regulatory agencies periodically review the allowance for loan losses. Such agencies may require additions to the allowance based on their judgments about information available to them at the time of their examination. The allowance is an estimate, and ultimate losses may vary from management’s estimate. Changes in the estimate are recorded in the results of operations in the period in which they become known, along with provisions for estimated losses incurred during that period. Premises and Equipment Land is carried at cost. Premises and equipment are carried at cost less accumulated depreciation. Depreciation for financial reporting purposes is calculated on the straight-line method over the estimated useful lives of assets. Leasehold improvements are depreciated over the shorter of the lease terms or the estimated useful lives of the improvements. Expected terms include lease renewal options to the extent that the exercise of such renewals is reasonably assured. Expenditures for major additions and improvements are capitalized while the costs of current maintenance and repairs are charged to operating expenses. The estimated useful lives of premises and improvements range from 5 to 40 years. For furniture, fixtures and equipment, the estimated useful lives range from 3 to 20 years. Goodwill and Identifiable Intangible Assets Goodwill represents the excess of the purchase price over the net fair value of the acquired businesses. Goodwill is not amortized but is tested for impairment at the reporting unit level, defined as the segment level, at least annually in the fourth quarter or more frequently whenever events or circumstances occur that indicate that it is more-likely-than-not that an impairment loss has occurred. In assessing impairment, the Corporation has the option to perform a qualitative analysis 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 the reporting unit is less than its carrying amount. If, after assessing the totality of such events or circumstances, we determine it is not more-likely-than-not that the fair value of a reporting unit is less than its carrying amount, then we would not be required to perform an impairment test. The quantitative impairment analysis requires a comparison of each reporting unit’s fair value to its carrying value to identify potential impairment. Goodwill impairment exists when a reporting unit’s carrying value of goodwill exceeds its implied fair value. Significant judgment is applied when goodwill is assessed for impairment. This judgment includes, but may not be limited to, the selection of appropriate discount rates, the identification of relevant market comparables and the development of cash flow projections. The selection and weighting of the various fair value techniques may result in a higher or lower fair value. Judgment is applied in determining the weightings that are most representative of fair value. Intangible assets identified in acquisitions consist of advisory contracts. The value attributed to intangible assets was based on the time period over which they are expected to generate economic benefits. Intangible assets are amortized over their estimated lives using a method that approximates the amount of economic benefits that are realized by the Corporation. Intangible assets with definite lives are tested for impairment whenever events or circumstances occur that indicate that the carrying amount may not be recoverable. If applicable, the Corporation tests each of the intangibles by comparing the carrying value of the intangible asset to the sum of undiscounted cash flows expected to be generated by the asset. If the carrying amount of the asset exceeds its undiscounted cash flows, then an impairment loss would be recognized for the amount by which the carrying amount exceeds its fair value. Impairment would result in a write-down to the estimated fair value based on the anticipated discounted future cash flows. The remaining useful life of the intangible assets that are being amortized is also evaluated to determine whether events and circumstances warrant a revision to the remaining period of amortization. Impairment of Long - Lived Assets Other than Goodwill Long-lived assets, including premises and equipment, are reviewed for impairment whenever events or changes in business circumstances indicate that the the carrying amount may not be fully recoverable. If impairment is determined to exist, any related impairment loss is calculated based on fair value. Impairment losses on assets to be disposed of, if any, are based on the estimated proceeds to be received, less costs of disposal. Property Acquired through Foreclosure or Repossession Property acquired through foreclosure or repossession is carried at the lower of cost or fair value less estimated costs to sell. Fair value of such assets is determined based on independent appraisals and other relevant factors. Any write-down to fair value at the time of foreclosure or repossession is charged to the allowance for loan losses. Subsequent to foreclosure or repossession, a valuation allowance is maintained for declines in market value and for estimated selling expenses. Upon sale of foreclosed property, any excess of the carrying value over the sales proceeds is recognized as a loss on sale. Any excess of sales proceeds over the carrying value of the foreclosed property is first applied as a recovery to the valuation allowance, if any, with the remainder being recognized as a gain on sale. Changes to the valuation allowance, expenses associated with ownership of these properties, and gains and losses from their sale are included in foreclosed property costs. Loans that are substantively repossessed include only those loans for which the Corporation has obtained control of the collateral, but has not completed legal foreclosure proceedings. Bank-Owned Life Insurance The investment in BOLI represents the cash surrender value of life insurance policies on the lives of certain employees who have provided positive consent allowing the Bank to be the beneficiary of such policies. Increases in the cash value of the policies, as well as insurance proceeds received, are recorded in noninterest income and are not subject to income taxes. The financial strength of the insurance carrier is reviewed prior to the purchase of BOLI and annually thereafter. Investment in Real Estate Limited Partnerships The Bank has a 99.9% ownership interest in two real estate limited partnerships that renovate, own and operate two low-income housing complexes. The Bank neither actively participates nor has a controlling interest in these limited partnerships and accounts for its investments under the equity method of accounting. The carrying value of the investments is recorded in other assets on the Consolidated Balance Sheet. Net losses generated by the partnership are recorded as a reduction to the Bank’s investment and as a reduction of other noninterest income in the Consolidated Statements of Income. Tax credits generated by the partnership are recorded as a reduction in the income tax provision in the year they are allowed for tax reporting purposes. The results of operations of the real estate limited partnerships are periodically reviewed to determine if the partnership generates sufficient operating cash flow to fund its current obligations. In addition, the current value of the underlying properties is compared to the outstanding debt obligations. If it is determined that the investment is permanently impaired, the carrying value will be written down to the estimated realizable value. Transfers and Servicing of Assets and Extinguishments of Liabilities The accounting for transfers and servicing of financial assets and extinguishments of liabilities is based on consistent application of a financial components approach that focuses on control. This approach distinguishes transfers of financial assets that are sales from transfers that are secured borrowings. After a transfer of financial assets, the Corporation recognizes all financial and servicing assets it controls and liabilities it has incurred and derecognizes financial assets it no longer controls and liabilities that have been extinguished. This financial components approach focuses on the assets and liabilities that exist after the transfer. Many of these assets and liabilities are components of financial assets that existed prior to the transfer. If a transfer does not meet the criteria for a sale, the transfer is accounted for as a secured borrowing with a pledge of collateral. Wealth Management Assets Under Administration Assets under administration represent assets held in a fiduciary or agency capacity for wealth management clients and are not included in the Consolidated Balance Sheets, as these are not assets of the Corporation. Wealth management revenue derived from the administration, management and custody of assets under administration are referred to as asset-based revenues. Revenue from Contracts with Customers Prior to January 1, 2018, fee revenue such as wealth management revenues and service charges on deposit accounts were recognized when earned or to the extent services were completed. Effective January 1, 2018, the Corporation adopted the provisions of Accounting Standards Update No. 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”), as amended. ASU 2014-09 provides a revenue recognition framework for contracts with customers unless those contracts are within the scope of other accounting standards. Revenue from contracts with customers is measured based on the consideration specified in the contract with a customer. The Corporation recognizes revenue from contracts with customers when it satisfies its performance obligations. The performance obligations are generally satisfied as services are rendered and can either be satisfied at a point in time or over time. The Corporation recognizes revenue that is transactional in nature and such revenue is earned at a point in time. Revenue that is recognized at a point in time includes card interchange fees (fee income related to debit card transactions), ATM fees, wire transfer fees, overdraft charge fees, and stop-payment and returned check fees. Such revenue is derived from transactional information and is recognized as revenue immediately as the transactions occur or upon providing the service to complete the customer’s transaction. The Corporation recognizes revenue over a period of time, generally monthly, as services are performed and performance obligations are satisfied. Such revenue includes wealth management revenues and service charges on deposit accounts. Wealth management revenues are categorized as either asset-based revenues or transaction-based revenues. Asset-based revenues include trust and investment management fees that are earned based upon a percentage of asset values under administration. Transaction-based revenues include financial planning fees, tax preparation fees, commissions and other service fees. Fee revenue from service charges on deposit accounts represent the service charges assessed to customer who hold deposit accounts at the Bank. In certain cases, other parties are involved with providing services to our customers. If the Corporation is a principal in the transaction (providing services itself or through a third party on its behalf), revenues are reported based on the gross consideration received from the customer and any related expenses are reported gross in noninterest expense. If the Corporation is an agent in the transaction (referring customers to another party to provide services), the Corporation reports its net fee or commission retained as revenue. For certain commissions and incentives, such as those paid to employees in our wealth management services and commercial banking segments in order to obtain customer contracts, contract cost assets are established. The contract cost assets are capitalized and amortized over the estimated useful life that the asset is expected to generate benefits. The amortization of the contract cost asset is recorded within salaries and employee benefits expense in the Consolidated Statements of Income. Pension Costs Pension benefits are accounted for using the net periodic benefit cost method, which recognizes the compensation cost of an employee’s pension benefit over that employee’s approximate service period. Pension benefit costs and benefit obligations incorporate various actuarial and other assumptions, including discount rates, mortality, rates of return on plan assets and compensation increases. Management evaluates these assumptions on an annual basis and makes modifications to the assumptions based on current rates and trends when it is appropriate to so do. The effect of modifications to those assumptions is recorded in other comprehensive income (loss) and amortized to net periodic cost over future periods. Management believes that the assumptions utilized in recording its obligations under its plans are reasonable based on its experience and market conditions.

Recently Issued Accounting Pron

Recently Issued Accounting Pronouncements	12 Months Ended
	Dec. 31, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements Accounting Standards Adopted in 2018 Revenue from Contracts with Customers - Topic 606 Accounting Standards Update No. 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”), was issued in May 2014 and provides a revenue recognition framework for any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of non-financial assets unless those contracts are within the scope of other accounting standards. As issued, ASU 2014-09 was effective for annual periods beginning after December 15, 2016, including interim periods within that reporting period with early adoption not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. In August 2015, Accounting Standards Update No. 2015-14, “Deferral of the Effective Date” (“ASU 2015-14”) was issued and delayed the effective date of ASU 2014-09 to annual and interim periods in fiscal years beginning after December 15, 2017. In 2016, Accounting Standards Update No. 2016-08, “Principal versus Agent Considerations” (“ASU 2016-08”), Accounting Standards Update No. 2016-10, “Identifying Performance Obligations and Licensing” (“ASU 2016-10”) and Accounting Standards Update No. 2016-12, “Narrow-Scope Improvements and Practical Expedients” (“ASU 2016-12”) were issued. These ASUs did not change the core principle for revenue recognition in Topic 606; instead, the amendments provided more detailed guidance in a few areas and additional implementation guidance and examples to reduce the degree of judgment necessary to comply with Topic 606. The effective date and transition requirements for ASU 2016-08, ASU 2016-10 and ASU 2016-12 were the same as those provided by ASU 2015-14. Management assembled a project team to address the changes pursuant to Topic 606. The project team completed a scope assessment and contract review for in-scope revenue streams. The Corporation's largest source of revenue is net interest income on financial assets and liabilities, which was explicitly excluded from the scope of this ASU. Revenue streams that were within the scope of Topic 606 include wealth management revenues, service charges on deposit accounts and card interchange fees. The Corporation adopted Topic 606 “Revenue from Contracts with Customers” effective January 1, 2018 and has applied the guidance to all contracts within the scope of Topic 606 as of that date. As a result, the Corporation has modified its accounting policy for revenue recognition as disclosed in Note 1 . The Corporation adopted the provisions of Topic 606 using the modified retrospective method, therefore, the prior period comparative information has not been adjusted and continues to be reported under Topic 605. Additionally, Topic 606 provided certain practical expedients. The Corporation applied the practical expedient pertaining to contracts with original expected duration of one year or less and therefore, does not disclose information about remaining performance obligations on such contracts. The Corporation also applied the practical expedient pertaining to contracts for which, at contract inception, the period between when the entity transfers the services and when the customer pays for those services was one year or less, and therefore, does not adjust the consideration from customers for the effects of a significant financing component. As the result of the adoption of Topic 606 on January 1, 2018, there was no cumulative effect adjustment required and there was no material impact on the Corporation’s consolidated financial statements. Financial Instruments - Overall - Topic 825 Accounting Standards Update No. 2016-01, “Recognition and Measurement of Financial Assets and Financial Liabilities” (“ASU 2016-01”), was issued in January 2016 and provides revised guidance related to the accounting for and reporting of financial instruments. Some of the main provisions include: requiring most equity securities to be reported at fair value with unrealized gains and losses reported in the income statement; requiring separate presentation of financial assets and liabilities by measurement category and form (i.e. securities or loans); clarifying that entities must assess valuation allowances on a deferred tax asset related to available for sale debt securities in combination with their other deferred tax assets; and eliminating the requirement to disclose the method and significant assumptions used to estimate fair value for financial instruments measured at amortized cost on the balance sheet. Certain provisions under ASU 2016-01 require prospective application, while other provisions require a modified retrospective application to all periods presented in the consolidated financial statements upon adoption. ASU 2016-01 was effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2017. Management adopted the provisions of ASU 2016-01 effective January 1, 2018. The adoption did not have a material impact on the Corporation’s consolidated financial statements. Accounting Standards Update No. 2018-03, “Technical Corrections and Improvements to Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities” (“ASU 2018-03”), was issued in February 2018 to clarify certain aspects of the guidance issued in ASU 2016-01. Companies, such as Washington Trust, were not required to adopt the provisions of ASU 2018-03 until the interim period beginning after June 15, 2018. However, early adoption was permitted, as long as ASU 2016-01 provisions were adopted. Management early adopted the provisions of ASU 2018-03 effective January 1, 2018. The adoption did not have an impact on the Corporation’s consolidated financial statements. Statement of Cash Flows - Topic 230 Accounting Standards Update No. 2016-15, “Classification of Certain Cash Receipts and Cash Payments” (“ASU 2016-15”), was issued in August 2016. ASU 2016-15 provides classification guidance on certain cash receipts and cash payments, including, but not limited to, debt prepayment costs, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of bank-owned life insurance policies and distributions received from equity method investees. The adoption of ASU 2016-15 requires a retrospective transition method applied to each period presented. This ASU was effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2017. Management adopted the provisions of ASU 2016-15 effective January 1, 2018. The adoption did not have a material impact on the Corporation’s consolidated financial statements. Accounting Standards Update No. 2016-18, “Restricted Cash” (“ASU 2016-18”), was issued in November 2016. ASU 2016-18 requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash. Restricted cash should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The adoption of ASU 2016-18 requires a retrospective transition method applied to each period presented. This ASU was effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2017. Management adopted the provisions of ASU 2016-18 effective January 1, 2018. The adoption did not have a material impact on the Corporation’s consolidated financial statements. Compensation - Retirement Benefits - Topic 715 Accounting Standards Update No. 2017-07, “Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost” (“ASU 2017-07”), was issued in March 2017. ASU 2017-07 requires that employers include the service cost component of net periodic benefit cost in the same line item as other employee compensation costs and all other components of net periodic benefit cost in a separate line item(s) in the statement of income. In addition, the line item in which the components of net periodic benefit cost other than the service cost are included shall be identified as such on the statement of income or in the notes to the financial statements. ASU 2017-07 was effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2017 requiring retrospective application for all periods presented. Management adopted the provisions of ASU 2017-07 effective January 1, 2018, utilizing the practical expedient that permitted employers to use the amounts previously disclosed in notes to financial statements as an estimation basis for applying the retrospective application requirements. The adoption of ASU 2017-07 resulted in an increase in salaries and employee benefits, a decrease in other expenses and no change to net income. The adoption did not have a material impact on the Corporation’s consolidated financial statements. Compensation - Stock Compensation - Topic 718 Accounting Standards Update No. 2017-09, “Scope of Modification Accounting” (“ASU 2017-09”), was issued in May 2017 to provide clarity when applying the guidance in Topic 718 to a change to the terms or conditions of a share-based payment award. ASU 2017-09 was effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2017, with provisions applied on a prospective basis. Management adopted the provisions of ASU 2017-09 effective January 1, 2018. The adoption did not have a material impact on the Corporation’s consolidated financial statements. Accounting Standards Pending Adoption Leases - Topic 842 Accounting Standards Update No. 2016-02, “Leases” (“ASU 2016-02”), was issued in February 2016 and provides revised guidance related to the accounting and reporting of leases. ASU 2016-02 requires lessees to recognize most leases on the balance sheet. The recognition, measurement and presentation of expenses and cash flows arising from a lease by a lessee will depend on its classification as a finance or operating lease. ASU 2016-02 requires a modified retrospective transition, with a number of practical expedients that entities may elect to apply. In January 2018, Accounting Standards Update No. 2018-01, “Leases (Topic 842): Land Easement Practical Expedient for Transition to Topic 842” was issued to address concerns about the costs and complexity of complying with the transition provisions of ASU 2016-02. In July 2018, Accounting Standards Update No. 2018-10, “Codification Improvements to Topic 842, Leases” was issued to provide more detailed guidance and additional clarification for implementing ASU 2016-02. Also in July 2018, Accounting Standards Update No. 2018-11, “Targeted Improvements” was issued and allows for an optional transition method in which the provisions of Topic 842 would be applied upon the adoption date and would not have to be retroactively applied to the earliest reporting period presented in the consolidated financial statements. The Corporation intends to use this optional transition method for the adoption of Topic 842. In December 2018, Accounting Standards Update No. 2018-20, “Leases (Topic 842) Narrow-Scope Improvement for Lessors” was issued to address lessors’ concerns about sales taxes and other similar taxes collected from lessees, certain lessor costs, and recognition of variable payments for contracts with lease and non-lease components. These ASUs are effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2018. Management assembled a project team to address the changes pursuant to Topic 842. The project team identified and reviewed all lease agreements in scope of Topic 842. The Corporation rents premises used in business operations under non-cancelable operating leases, which as of December 31, 2018 are not reflected in its Consolidated Balance Sheets. Upon adoption of ASU 2016-02 on January 1, 2019, the Corporation expects to recognize $28.9 million in operating lease right-of-use-assets, $30.9 million in operating lease liabilities, a reduction in rent-related liabilities of $2.9 million , a reduction of net deferred tax assets of $222 thousand and a cumulative effect adjustment (net of taxes) that will increase beginning retained earnings by approximately $722 thousand in the Consolidated Balance Sheet. The Corporation does not expect a material change to the timing in recognition of expense associated with our leases in the Consolidated Statements of Income. Financial Instruments - Credit Losses - Topic 326 Accounting Standards Update No. 2016-13, “Financial Instruments - Credit Losses” (“ASU 2016-13”), was issued in June 2016. ASU 2016-13 requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts and requires enhanced disclosures related to the significant estimates and judgments used in estimating credit losses, as well as the credit quality and underwriting standards of an organization’s portfolio. In addition, ASU 2016-13 amends the accounting for credit losses on available-for-sale debt securities and purchased financial assets with credit deterioration. ASU 2016-13 provides for a modified retrospective transition, resulting in a cumulative-effect adjustment to equity as of the beginning of the period in which the guidance is effective, except for debt securities for which an other-than-temporary impairment has previously been recognized. For these debt securities, a prospective transition approach will be adopted in order to maintain the same amortized cost prior to and subsequent to the effective date of ASU 2016-13. This ASU is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2019, with early adoption permitted in 2019. The Corporation will adopt ASU 2016-03 on January 1, 2020 and is currently evaluating the effect that this ASU will have on the consolidated financial statements and disclosures. Management has assembled a project team that meets regularly to evaluate the provisions of this ASU, to address the additional data requirements necessary, to determine the approach for implementation and to identify new internal controls over enhanced processes that will be put into place for estimating the allowance under ASU 2016-13. This has included assessing the adequacy of existing loan and loss data, as well as developing models for default and loss estimates. The Corporation expects to continue the validation of models and the development of accounting policies and internal controls throughout 2019. Additionally, the Corporation expects to execute “trial” or “parallel” runs of its ASU 2016-13 compliant methodology in 2019. Derivatives and Hedging - Topic 815 Accounting Standards Update No. 2017-12, “Targeted Improvements to Accounting for Hedging Activities” (“ASU 2017-12”), was issued in August 2017 to better align financial reporting for hedging activities with the economic objectives of those activities. ASU 2017-12 is effective for fiscal years beginning after December 15, 2018, with early adoption, including adoption in an interim period, permitted. Upon adoption, the provisions of ASU 2017-12 will be applied using a modified retrospective transition method with the cumulative effect of the change in the opening balance of retained earnings. In addition, ASU 2017-12 also permits the reclassification of eligible securities from the held-to-maturity classification to the available-for-sale classification. The Corporation will adopt the provisions of ASU 2017-12 on January 1, 2019. As permitted by ASU 2017-12, debt securities classified as held-to-maturity with an amortized cost of $10.4 million and a fair value of $10.3 million will be reclassified to available-for-sale upon the adoption date. An unrealized loss of $99 thousand associated with these debt securities will be recognized in the accumulated other comprehensive income component of shareholders’ equity at the date of adoption. The adoption of ASU 2017-12 is not expected to have a material impact on the Corporation’s consolidated financial statements. Accounting Standards Update No. 2018-16, “Inclusion of the Secured Overnight Financing Rate (SOFR) Overnight Index Swap (OIS) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes” (“ASU 2018-16”), was issued in October 2018 to permit the use of the Overnight Index Swap rate based on the Secured Overnight Financing Rate as a U.S. benchmark interest rate for hedge accounting purposes under Topic 815 in addition to existing benchmark interest rates that are currently used for hedge accounting. ASU 2018-16 is effective for fiscal years beginning after December 15, 2018, and interim periods with those fiscal years. The provisions require prospective application for qualifying new or re-designated hedging relationships entered into on or after the date of adoption. The adoption of ASU 2018-16 is not expected to have a material impact on the Corporation’s consolidated financial statements. Fair Value Measurement - Topic 820 Accounting Standards Update No. 2018-13, “Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement” (“ASU 2018-13”), was issued in August 2018 to modify the disclosure requirements related to fair value. ASU 2018-13 is effective for fiscal years beginning after December 15, 2019, with early adoption permitted, including adoption in an interim period. Certain provisions under ASU 2018-13 require prospective application, while other provisions require retrospective application to all periods presented in the consolidated financial statements upon adoption. The adoption of ASU 2018-13 is not expected to have a material impact on the Corporation’s consolidated financial statements. Compensation - Retirement Benefits - Topic 715 Accounting Standards Update No. 2018-14, “Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans” (“ASU 2018-14”), was issued in August 2018 to modify the disclosure requirements associated with defined benefit pension plans and other postretirement plans. ASU 2018-14 is effective for fiscal years ending after December 15, 2020, with early adoption permitted. The provisions under ASU 2018-14 are required to be applied retrospectively. The adoption of ASU 2018-14 is not expected to have a material impact on the Corporation’s consolidated financial statements. Intangibles - Goodwill and Other - Internal-Use Software - Topic 350 Accounting Standards Update No. 2018-15, “Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract” (“ASU 2018-15”), was issued in August 2018 to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with those requirements that currently exist in GAAP for capitalizing implementation costs incurred to develop or obtain internal-use software. Implementation costs would either be capitalized or expensed as incurred depending on the project stage. All costs in the preliminary and post-implementation project stages are expensed as incurred, while certain costs within the application development stage are capitalized. The provisions under ASU 2018-15 can either be applied retrospectively or prospectively. ASU 2018-15 is effective for fiscal years beginning after December 15, 2019, with early adoption permitted, including adoption in an interim period. The adoption of ASU 2018-15 is not expected to have a material impact on the Corporation’s consolidated financial statements.

Cash and Due from Banks

Cash and Due from Banks	12 Months Ended
	Dec. 31, 2018
Cash and Cash Equivalents [Abstract]
Cash and Due from Banks	Cash and Due from Banks The Bank maintains certain average reserve balances to meet the requirements of the Board of Governors of the Federal Reserve System (“FRB”). Some or all of these reserve requirements may be satisfied with vault cash. Reserve balances amounted to $21.6 million and $14.1 million , respectively, at December 31, 2018 and 2017 and were included in cash and due from banks in the Consolidated Balance Sheets. As of December 31, 2018 and 2017 , cash and due from banks includes interest-bearing deposits in other banks of $33.7 million and $31.9 million , respectively.

Securities

Securities	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Securities	Securities The following tables present the amortized cost, gross unrealized holding gains, gross unrealized holding losses and fair value of securities by major security type and class of security: (Dollars in thousands) December 31, 2018 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Securities Available for Sale: Obligations of U.S. government-sponsored enterprises $246,708 $442 ($4,467 ) $242,683 Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises 675,368 1,943 (16,518 ) 660,793 Obligations of states and political subdivisions 935 2 — 937 Individual name issuer trust preferred debt securities 13,307 — (1,535 ) 11,772 Corporate bonds 13,402 — (1,777 ) 11,625 Total securities available for sale $949,720 $2,387 ($24,297 ) $927,810 Held to Maturity: Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises $10,415 $— ($99 ) $10,316 Total securities held to maturity 10,415 — (99 ) 10,316 Total securities $960,135 $2,387 ($24,396 ) $938,126 (Dollars in thousands) December 31, 2017 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Securities Available for Sale: Obligations of U.S. government-sponsored enterprises $161,479 $— ($3,875 ) $157,604 Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises 594,944 3,671 (7,733 ) 590,882 Obligations of states and political subdivisions 2,355 4 — 2,359 Individual name issuer trust preferred debt securities 18,106 — (1,122 ) 16,984 Corporate bonds 13,917 13 (805 ) 13,125 Total securities available for sale $790,801 $3,688 ($13,535 ) $780,954 Held to Maturity: Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises $12,541 $180 $— $12,721 Total securities held to maturity 12,541 180 — 12,721 Total securities $803,342 $3,868 ($13,535 ) $793,675 At December 31, 2018 and 2017 , securities with a fair value of $439.7 million and $357.8 million , respectively, were pledged as collateral for FHLB borrowings, potential borrowings with the FRB, certain public deposits and for other purposes. See Note 11 for additional discussion of FHLB borrowings. The schedule of maturities of debt securities available for sale and held to maturity is presented below. Mortgage-backed securities are included based on weighted average maturities, adjusted for anticipated prepayments. All other debt securities are included based on contractual maturities. Actual maturities may differ from amounts presented because certain issuers have the right to call or prepay obligations with or without call or prepayment penalties. (Dollars in thousands) Available for Sale Held to Maturity December 31, 2018 Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $69,070 $67,584 $1,329 $1,317 Due after one year to five years 328,420 321,760 4,396 4,354 Due after five years to ten years 337,589 329,330 3,580 3,546 Due after ten years 214,641 209,136 1,110 1,099 Total securities $949,720 $927,810 $10,415 $10,316 Included in the above table are debt securities with an amortized cost balance of $273.1 million and a fair value of $265.8 million at December 31, 2018 that are callable at the discretion of the issuers. Final maturities of the callable securities range from 5 months to 18 years, with call features ranging from 1 month to 3 years. Other-Than-Temporary Impairment Assessment Management assesses whether the decline in fair value of investment securities is other-than-temporary on a regular basis. Unrealized losses on debt securities may occur from current market conditions, increases in interest rates since the time of purchase, a structural change in an investment, volatility of earnings of a specific issuer, or deterioration in credit quality of the issuer. Management evaluates impairments in value both qualitatively and quantitatively to assess whether they are other-than-temporary. The following tables summarize temporarily impaired securities, segregated by length of time the securities have been in a continuous unrealized loss position: (Dollars in thousands) Less than 12 Months 12 Months or Longer Total December 31, 2018 # Fair Value Unrealized Losses # Fair Value Unrealized Losses # Fair Value Unrealized Losses Obligations of U.S. government-sponsored enterprises — $— $— 16 $157,032 ($4,467 ) 16 $157,032 ($4,467 ) Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises 10 47,060 (439 ) 51 438,701 (16,178 ) 61 485,761 (16,617 ) Individual name issuer trust preferred debt securities — — — 5 11,772 (1,535 ) 5 11,772 (1,535 ) Corporate bonds 3 1,198 (9 ) 5 10,427 (1,768 ) 8 11,625 (1,777 ) Total temporarily impaired securities 13 $48,258 ($448 ) 77 $617,932 ($23,948 ) 90 $666,190 ($24,396 ) (Dollars in thousands) Less than 12 Months 12 Months or Longer Total December 31, 2017 # Fair Value Unrealized Losses # Fair Value Unrealized Losses # Fair Value Unrealized Losses Obligations of U.S. government-sponsored enterprises 8 $69,681 ($798 ) 8 $87,923 ($3,077 ) 16 $157,604 ($3,875 ) Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises 20 128,965 (613 ) 22 279,693 (7,120 ) 42 408,658 (7,733 ) Individual name issuer trust preferred debt securities — — — 7 16,984 (1,122 ) 7 16,984 (1,122 ) Corporate bonds 3 921 (5 ) 3 10,980 (800 ) 6 11,901 (805 ) Total temporarily impaired securities 31 $199,567 ($1,416 ) 40 $395,580 ($12,119 ) 71 $595,147 ($13,535 ) Further deterioration in credit quality of the underlying issuers of the securities, deterioration in the condition of the financial services industry, worsening of the current economic environment, or additional declines in real estate values, among other things, may further affect the fair value of these securities and increase the potential that certain unrealized losses be designated as other-than-temporary in future periods, and the Corporation may incur write-downs. Obligations of U.S. Government Agency and U.S. Government-Sponsored Enterprise Securities, including Mortgage-Backed Securities The gross unrealized losses on U.S. government agency and U.S government-sponsored debt securities, including mortgage-backed securities, were primarily attributable to relative changes in interest rates since the time of purchase. The contractual cash flows for these securities are guaranteed by U.S. government agencies and U.S. government-sponsored enterprises. Management believes that the unrealized losses on these debt security holdings are a function of changes in investment spreads and interest rate movements and not changes in credit quality. Management expects to recover the entire amortized cost basis of these securities. Furthermore, the Corporation does not intend to sell these securities and it is not more-likely-than-not that the Corporation will be required to sell these securities before recovery of their cost basis, which may be maturity. Therefore, management does not consider these investments to be other-than-temporarily impaired at December 31, 2018 . Individual Name Issuer Trust Preferred Debt Securities Included in debt securities in an unrealized loss position at December 31, 2018 were five trust preferred securities issued by four individual companies in the banking sector. Management believes the unrealized losses on these holdings were attributable to the general widening of spreads for this category of debt securities issued by financial services companies since the time these securities were purchased. Based on the information available through the filing date of this report, all individual name issuer trust preferred debt securities held in our portfolio continue to accrue interest and make payments as expected with no payment deferrals or defaults on the part of the issuers. As of December 31, 2018 , individual name issuer trust preferred debt securities with an amortized cost of $6.1 million and unrealized losses of $744 thousand were rated below investment grade by Standard & Poors, Inc. Management reviewed the collectability of these securities taking into consideration such factors as the financial condition of the issuers, reported regulatory capital ratios of the issuers, credit ratings, including ratings in effect as of the reporting period date as well as credit rating changes between the reporting period date and the filing date of this report, and other information. We noted no additional downgrades to below investment grade between December 31, 2018 and the filing date of this report. Based on this review, management concluded that it expects to recover the entire amortized cost basis of these securities. Furthermore, the Corporation does not intend to sell these securities and it is not more-likely-than-not that the Corporation will be required to sell these securities before recovery of their cost basis, which may be maturity. Therefore, management does not consider these investments to be other-than-temporarily impaired at December 31, 2018 . Corporate Bonds At December 31, 2018 , the Corporation had eight corporate bond holdings with unrealized losses totaling $1.8 million . These investment grade corporate bonds were issued by large corporations, primarily in the financial services industry. Management believes the unrealized losses on these bonds are a function of the changes in the investment spreads and interest rate movements and not changes in the credit quality of the issuers of the debt securities. Management expects to recover the entire amortized cost basis of these securities. Furthermore, the Corporation does not intend to sell these securities and it is not more-likely-than-not that the Corporation will be required to sell these securities before recovery of their cost basis, which may be maturity. Therefore, management does not consider these investments to be other-than-temporarily impaired at December 31, 2018 .

Loans

Loans	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Loans	Loans The following is a summary of loans: (Dollars in thousands) December 31, 2018 December 31, 2017 Amount % Amount % Commercial: Commercial real estate (1) $1,392,408 38 % $1,210,495 36 % Commercial & industrial (2) 620,704 17 612,334 18 Total commercial 2,013,112 55 1,822,829 54 Residential Real Estate: Residential real estate (3) 1,360,387 37 1,227,248 36 Consumer: Home equity 280,626 8 292,467 9 Other (4) 26,235 — 31,527 1 Total consumer 306,861 8 323,994 10 Total loans (5) $3,680,360 100 % $3,374,071 100 % (1) Consists of commercial mortgages primarily secured by income-producing property, as well as construction and development loans. Construction and development loans are made to businesses for land development or the on-site construction of industrial, commercial, or residential buildings. (2) Consists of loans to businesses and individuals, a substantial portion of which are fully or partially collateralized by real estate. (3) Consists of mortgage and homeowner construction loans secured by one- to four- family residential properties. (4) Consists of loans to individuals secured by general aviation aircraft and other personal installment loans. (5) Includes net unamortized loan origination costs of $4.7 million and $3.8 million , respectively, at December 31, 2018 and 2017 and net unamortized premiums on purchased loans of $703 thousand and $878 thousand , respectively, at December 31, 2018 and 2017 . As of December 31, 2018 and 2017 , loans amounting to $2.0 billion and $1.6 billion , respectively, were pledged as collateral to the FHLB under a blanket pledge agreement and to the FRB for the discount window. See Note 11 for additional disclosure regarding borrowings. Concentrations of Credit Risk A significant portion of our loan portfolio is concentrated among borrowers in southern New England and a substantial portion of the portfolio is collateralized by real estate in this area. The ability of single family residential and consumer borrowers to honor their repayment commitments is generally dependent on the level of overall economic activity within the market area and real estate values. The ability of commercial borrowers to honor their repayment commitments is dependent on the general economy as well as the health of the real estate economic sector in the Corporation’s market area. Past Due Loans Past due status is based on the contractual payment terms of the loan. The following tables present an aging analysis of past due loans, segregated by class of loans: (Dollars in thousands) Days Past Due December 31, 2018 30-59 60-89 Over 90 Total Past Due Current Total Loans Commercial: Commercial real estate $155 $925 $— $1,080 $1,391,328 $1,392,408 Commercial & industrial — — — — 620,704 620,704 Total commercial 155 925 — 1,080 2,012,032 2,013,112 Residential Real Estate: Residential real estate 6,318 2,693 1,509 10,520 1,349,867 1,360,387 Consumer: Home equity 1,281 156 552 1,989 278,637 280,626 Other 33 — — 33 26,202 26,235 Total consumer 1,314 156 552 2,022 304,839 306,861 Total loans $7,787 $3,774 $2,061 $13,622 $3,666,738 $3,680,360 (Dollars in thousands) Days Past Due December 31, 2017 30-59 60-89 Over 90 Total Past Due Current Total Loans Commercial: Commercial real estate $6 $— $4,954 $4,960 $1,205,535 $1,210,495 Commercial & industrial 3,793 2 281 4,076 608,258 612,334 Total commercial 3,799 2 5,235 9,036 1,813,793 1,822,829 Residential Real Estate: Residential real estate 1,678 2,274 3,903 7,855 1,219,393 1,227,248 Consumer: Home equity 2,798 75 268 3,141 289,326 292,467 Other 29 — 14 43 31,484 31,527 Total consumer 2,827 75 282 3,184 320,810 323,994 Total loans $8,304 $2,351 $9,420 $20,075 $3,353,996 $3,374,071 Included in past due loans as of December 31, 2018 and 2017 , were nonaccrual loans of $8.6 million and $11.8 million , respectively. All loans 90 days or more past due at December 31, 2018 and 2017 were classified as nonaccrual. Impaired Loans Impaired loans include nonaccrual loans and loans restructured in a troubled debt restructuring. The Corporation identifies loss allocations for impaired loans on an individual loan basis. The following is a summary of impaired loans: (Dollars in thousands) Recorded Investment (1) Unpaid Principal Related Allowance December 31, 2018 2017 2018 2017 2018 2017 No Related Allowance Recorded Commercial: Commercial real estate $925 $— $926 $— $— $— Commercial & industrial 4,681 4,986 4,732 5,081 — — Total commercial 5,606 4,986 5,658 5,081 — — Residential Real Estate: Residential real estate 9,347 9,069 9,695 9,256 — — Consumer: Home equity 1,360 557 1,360 557 — — Other — 14 — 14 — — Total consumer 1,360 571 1,360 571 — — Subtotal 16,313 14,626 16,713 14,908 — — With Related Allowance Recorded Commercial: Commercial real estate $— $4,954 $— $9,910 $— $1,018 Commercial & industrial 52 191 73 212 — 1 Total commercial 52 5,145 73 10,122 — 1,019 Residential Real Estate: Residential real estate 364 715 390 741 100 104 Consumer: Home equity 85 — 85 — 24 — Other 22 133 22 132 3 6 Total consumer 107 133 107 132 27 6 Subtotal 523 5,993 570 10,995 127 1,129 Total impaired loans $16,836 $20,619 $17,283 $25,903 $127 $1,129 Total: Commercial $5,658 $10,131 $5,731 $15,203 $— $1,019 Residential real estate 9,711 9,784 10,085 9,997 100 104 Consumer 1,467 704 1,467 703 27 6 Total impaired loans $16,836 $20,619 $17,283 $25,903 $127 $1,129 (1) The recorded investment in impaired loans consists of unpaid principal balance, net of charge-offs, interest payments received applied to principal and unamortized deferred loan origination fees and costs. For accruing impaired loans (troubled debt restructurings for which management has concluded that the collectability of the loan is not in doubt), the recorded investment also includes accrued interest. The following table presents the average recorded investment balance of impaired loans and interest income recognized on impaired loans segregated by loan class: (Dollars in thousands) Average Recorded Investment Interest Income Recognized Years ended December 31, 2018 2017 2016 2018 2017 2016 Commercial: Commercial real estate $1,050 $8,425 $13,201 $— $79 $239 Commercial & industrial 5,403 6,445 3,540 259 281 99 Total commercial 6,453 14,870 16,741 259 360 338 Residential real estate: Residential real estate 9,645 14,571 12,848 393 444 322 Consumer: Home equity 1,182 685 1,587 52 31 48 Other 69 143 147 5 10 11 Total consumer 1,251 828 1,734 57 41 59 Totals $17,349 $30,269 $31,323 $709 $845 $719 Nonaccrual Loans The following is a summary of nonaccrual loans, segregated by class of loans: (Dollars in thousands) December 31, 2018 2017 Commercial: Commercial real estate $925 $4,954 Commercial & industrial — 283 Total commercial 925 5,237 Residential Real Estate: Residential real estate 9,346 9,414 Consumer: Home equity 1,436 544 Other — 16 Total consumer 1,436 560 Total nonaccrual loans $11,707 $15,211 Accruing loans 90 days or more past due $— $— As of December 31, 2018 and 2017 , loans secured by one- to four-family residential property amounting to $761 thousand and $4.4 million , respectively, were in process of foreclosure. Nonaccrual loans of $3.1 million and $3.4 million , respectively, were current as to the payment of principal and interest as of December 31, 2018 and 2017 . There were no significant commitments to lend additional funds to borrowers whose loans were on nonaccrual status at December 31, 2018 . Troubled Debt Restructurings The recorded investment in troubled debt restructurings consists of unpaid principal balance, net of charge-offs and unamortized deferred loan origination fees and costs, at the time of the restructuring. For accruing troubled debt restructured loans, the recorded investment also includes accrued interest. The recorded investment in troubled debt restructurings was $5.6 million and $11.2 million , respectively, at December 31, 2018 and 2017 . The allowance for loan losses included specific reserves for these troubled debt restructurings of $103 thousand and $1.1 million , respectively, at December 31, 2018 and 2017 . In 2018 , there was one loan modified as a troubled debt restructuring with a pre-modification and post-modification recorded investment of $608 thousand . This troubled debt restructuring included a combination of concessions pertaining to maturity and interest only payment terms. There were no loans modified as a troubled debt restructuring in 2017 . In 2018 , payment defaults on troubled debt restructured loans modified within the previous 12 months occurred on one loan with a carrying value of $608 thousand at the time of default. In 2017 , there were no payment defaults on troubled debt restructured loans modified within the previous 12 months. As of December 31, 2018 , there were no significant commitments to lend additional funds to borrowers whose loans were restructured. Credit Quality Indicators Commercial The Corporation utilizes an internal rating system to assign a risk to each of its commercial loans. Loans are rated on a scale of 1 to 10. This scale can be assigned to three broad categories including “pass” for ratings 1 through 6, “special mention” for 7-rated loans, and “classified” for loans rated 8, 9 or 10. The loan rating system takes into consideration parameters including the borrower’s financial condition, the borrower’s performance with respect to loan terms, the adequacy of collateral, the adequacy of guarantees and other credit quality characteristics. The weighted average risk rating of the Corporation’s commercial loan portfolio was 4.74 at December 31, 2018 and 4.70 at December 31, 2017 . For non-impaired loans, the Corporation takes the risk rating into consideration along with other credit attributes in the establishment of an appropriate allowance for loan losses. A description of the commercial loan categories is as follows: Pass - Loans with acceptable credit quality, defined as ranging from superior or very strong to a status of lesser stature. Superior or very strong credit quality is characterized by a high degree of cash collateralization or strong balance sheet liquidity. Lesser stature loans have an acceptable level of credit quality but exhibit some weakness in various credit metrics such as collateral adequacy, cash flow, secondary sources of repayment, or performance inconsistency or may be in an industry or of a loan type known to have a higher degree of risk. Special Mention - Loans with potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the asset or in the Bank’s position as creditor at some future date. Special Mention assets are not adversely classified and do not expose the Bank to sufficient risk to warrant adverse classification. Examples of these conditions include but are not limited to outdated or poor quality financial data, strains on liquidity and leverage, losses or negative trends in operating results, marginal cash flow, weaknesses in occupancy rates or trends in the case of commercial real estate and frequent delinquencies. Classified - Loans identified as “substandard,” “doubtful” or “loss” based on criteria consistent with guidelines provided by banking regulators. A “substandard” loan has defined weaknesses which make payment default or principal exposure likely, but not yet certain. Such loans are apt to be dependent upon collateral liquidation, a secondary source of repayment or an event outside of the normal course of business. The loans are closely watched and are either already on nonaccrual status or may be placed on nonaccrual status when management determines there is uncertainty of collectability. A “doubtful” loan is placed on nonaccrual status and has a high probability of loss, but the extent of the loss is difficult to quantify due to dependency upon collateral having a value that is difficult to determine or upon some near-term event which lacks certainty. A loan in the “loss” category is considered generally uncollectible or the timing or amount of payments cannot be determined. “Loss” is not intended to imply that the loan has no recovery value, but rather, it is not practical or desirable to continue to carry the asset. The Corporation’s procedures call for loan ratings and classifications to be revised whenever information becomes available that indicates a change is warranted. On a quarterly basis, management reviews the criticized loan portfolio, which generally consists of commercial loans that are risk-rated special mention or worse, and other selected loans. Management’s review focuses on the current status of the loans and strategies to improve the credit. An annual loan review program is conducted by a third party to provide an independent evaluation of the creditworthiness of the commercial loan portfolio, the quality of the underwriting and credit risk management practices and the appropriateness of the risk rating classifications. This review is supplemented with selected targeted internal reviews of the commercial loan portfolio. The following table presents the commercial loan portfolio, segregated by category of credit quality indicator: (Dollars in thousands) Pass Special Mention Classified December 31, 2018 2017 2018 2017 2018 2017 Commercial: Commercial real estate $1,387,666 $1,205,381 $205 $— $4,537 $5,114 Commercial & industrial 559,019 592,749 50,426 9,804 11,259 9,781 Total commercial $1,946,685 $1,798,130 $50,631 $9,804 $15,796 $14,895 Residential and Consumer Management monitors the relatively homogeneous residential real estate and consumer loan portfolios on an ongoing basis using delinquency information by loan type. For non-impaired residential real estate and consumer loans, the Corporation assigns loss allocation factors to each respective loan type. Other techniques are utilized to monitor indicators of credit deterioration in the residential real estate loans and consumer loan portfolios. Among these techniques is the periodic tracking of loans with an updated Fair Isaac Corporation (“FICO”) score and an estimated loan to value (“LTV”) ratio. LTV ratio is determined via statistical modeling analyses. The indicated LTV levels are estimated based on such factors as the location, the original LTV ratio, and the date of origination of the loan and do not reflect actual appraisal amounts. The results of these analyses and other loan review procedures are taken into consideration in the determination of loss allocation factors for residential mortgage and home equity consumer credits. The following table presents the residential and consumer loan portfolios, segregated by loan type and credit quality indicator: (Dollars in thousands) Current Past Due December 31, 2018 2017 2018 2017 Residential Real Estate: Self-originated mortgages $1,238,402 $1,091,291 $9,079 $6,413 Purchased mortgages 111,465 128,102 1,441 1,442 Total residential real estate $1,349,867 $1,219,393 $10,520 $7,855 Consumer: Home equity $278,637 $289,326 $1,989 $3,141 Other 26,202 31,484 33 43 Total consumer $304,839 $320,810 $2,022 $3,184 Loan Servicing Activities Loans sold with servicing retained result in the capitalization of loan servicing rights. The following table presents an analysis of loan servicing rights: (Dollars in thousands) Loan Servicing Rights Valuation Allowance Total Balance at December 31, 2015 $3,348 ($1 ) $3,347 Loan servicing rights capitalized 1,412 — 1,412 Amortization (1,267 ) — (1,267 ) Decrease in impairment reserve — 1 1 Balance at December 31, 2016 3,493 — 3,493 Loan servicing rights capitalized 1,104 — 1,104 Amortization (984 ) — (984 ) Balance at December 31, 2017 3,613 — 3,613 Loan servicing rights capitalized 905 — 905 Amortization (867 ) — (867 ) Balance at December 31, 2018 $3,651 $— $3,651 The following table presents estimated aggregate amortization expense related to loan servicing assets: (Dollars in thousands) Years ending December 31: 2019 $768 2020 606 2021 479 2022 378 2023 299 2024 and thereafter 1,121 Total estimated amortization expense $3,651 Loans sold to others are serviced by the Corporation on a fee basis under various agreements. Loans serviced for others are not included in the Consolidated Balance Sheets. The following table presents the balance of loans serviced for others by type of loan: (Dollars in thousands) December 31, 2018 2017 Residential mortgages $588,534 $568,311 Commercial loans 142,218 108,539 Total $730,752 $676,850

Allowance for Loan Losses

Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Allowance for Loan Losses	Allowance for Loan Losses The allowance for loan losses is management’s best estimate of incurred losses inherent in the loan portfolio as of the balance sheet date. The Corporation uses a methodology to systematically measure the amount of estimated loan loss exposure inherent in the loan portfolio for purposes of establishing a sufficient allowance for loan losses. The methodology includes: (1) the identification of loss allocations for individual loans deemed to be impaired and (2) the application of loss allocation factors for non-impaired loans based on historical loss experience and estimated loss emergence period, with adjustments for various exposures that management believes are not adequately represented by historical loss experience. The following table presents the activity in the allowance for loan losses for the year ended December 31, 2018 : (Dollars in thousands) Commercial Consumer CRE (1) C&I (2) Total Commercial Residential Real Estate Home Equity Other Total Consumer Total Beginning Balance $12,729 $5,580 $18,309 $5,427 $2,412 $340 $2,752 $26,488 Charge-offs (627 ) (10 ) (637 ) (250 ) (193 ) (107 ) (300 ) (1,187 ) Recoveries 25 119 144 21 29 27 56 221 Provision 3,254 158 3,412 (1,211 ) (645 ) (6 ) (651 ) 1,550 Ending Balance $15,381 $5,847 $21,228 $3,987 $1,603 $254 $1,857 $27,072 (1) Commercial real estate loans. (2) Commercial & industrial loans. The following table presents the activity in the allowance for loan losses for the year ended December 31, 2017 : (Dollars in thousands) Commercial Consumer CRE (1) C&I (2) Total Commercial Residential Real Estate Home Equity Other Total Consumer Total Beginning Balance $11,166 $6,992 $18,158 $5,252 $1,889 $705 $2,594 $26,004 Charge-offs (1,867 ) (336 ) (2,203 ) (74 ) (79 ) (106 ) (185 ) (2,462 ) Recoveries 82 169 251 39 33 23 56 346 Provision 3,348 (1,245 ) 2,103 210 569 (282 ) 287 2,600 Ending Balance $12,729 $5,580 $18,309 $5,427 $2,412 $340 $2,752 $26,488 (1) Commercial real estate loans. (2) Commercial & industrial loans. The following table presents the activity in the allowance for loan losses for the year ended December 31, 2016 : (Dollars in thousands) Commercial Consumer CRE (1) C&I (2) Total Commercial Residential Real Estate Home Equity Other Total Consumer Total Beginning Balance $10,898 $8,202 $19,100 $5,460 $1,915 $594 $2,509 $27,069 Charge-offs (5,816 ) (759 ) (6,575 ) (200 ) (147 ) (90 ) (237 ) (7,012 ) Recoveries 56 156 212 11 37 37 74 297 Provision 6,028 (607 ) 5,421 (19 ) 84 164 248 5,650 Ending Balance $11,166 $6,992 $18,158 $5,252 $1,889 $705 $2,594 $26,004 (1) Commercial real estate loans. (2) Commercial & industrial loans. The following table presents the Corporation’s loan portfolio and associated allowance for loan losses by portfolio segment and by impairment methodology. (Dollars in thousands) December 31, 2018 December 31, 2017 Related Allowance Related Allowance Loans Loans Loans Individually Evaluated For Impairment Commercial: Commercial real estate $925 $— $4,954 $1,018 Construction & industrial 4,714 — 5,157 1 Total commercial 5,639 — 10,111 1,019 Residential Real Estate: Residential real estate 9,710 100 9,783 104 Consumer: Home equity 1,445 24 557 — Other 22 3 147 6 Total consumer 1,467 27 704 6 Subtotal 16,816 127 20,598 1,129 Loans Collectively Evaluated For Impairment Commercial: Commercial real estate 1,391,483 15,381 1,205,541 11,711 Commercial & industrial 615,990 5,847 607,177 5,579 Total commercial 2,007,473 21,228 1,812,718 17,290 Residential Real Estate: Residential real estate 1,350,677 3,887 1,217,465 5,323 Consumer: Home equity 279,182 1,579 291,910 2,412 Other 26,212 251 31,380 334 Total consumer 305,394 1,830 323,290 2,746 Subtotal 3,663,544 26,945 3,353,473 25,359 Total $3,680,360 $27,072 $3,374,071 $26,488

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment The following presents a summary of premises and equipment: (Dollars in thousands) December 31, 2018 2017 Land $6,020 $6,020 Premises and improvements 40,210 38,793 Furniture, fixtures and equipment 24,798 26,240 Total premises and equipment 71,028 71,053 Less accumulated depreciation 42,023 42,720 Total premises and equipment, net $29,005 $28,333 Depreciation of premises and equipment amounted to $3.3 million , $3.5 million and $3.7 million , respectively, for the years ended December 31, 2018 , 2017 , and 2016 .

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangibles	Goodwill and Intangible Assets The following table presents the carrying value of goodwill at the reporting unit (or business segment) level: (Dollars in thousands) December 31, 2018 2017 Commercial Banking Segment $22,591 $22,591 Wealth Management Services Segment 41,318 41,318 Balance at December 31, 2018 $63,909 $63,909 The balance of goodwill in the Commercial Banking segment arose from the acquisition of First Financial Corp. in 2002. The balance of goodwill in the Wealth Management Services segment arose from the 2005 acquisition of Weston Financial and the 2015 acquisition of Halsey. The following table presents the components of intangible assets: (Dollars in thousands) December 31, 2018 2017 Gross carrying amount $20,803 $20,803 Accumulated amortization 12,641 11,663 Net amount $8,162 $9,140 The balance of intangible assets at December 31, 2018 includes wealth management advisory contracts resulting from the 2005 acquisition of Weston Financial and the 2015 acquisition of Halsey. The wealth management advisory contracts resulting from the Weston Financial acquisition are being amortized over a 20 -year life using a declining balance method, based on expected attrition for the current customer base derived from historical runoff data. The wealth management advisory contracts resulting from the acquisition of Halsey are being amortized on a straight-line basis over a 15 -year life. Amortization expense for the years ended December 31, 2018 , 2017 , and 2016 , amounted to $979 thousand , $1.0 million and $1.3 million , respectively. The following table presents estimated annual amortization expense for intangible assets at December 31, 2018 : (Dollars in thousands) Years ending December 31, 2019 $944 2020 914 2021 890 2022 860 2023 843 2024 and thereafter 3,711

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Tax Act was signed into law in 2017. The enactment of the Tax Act required companies to revalue deferred tax assets and liabilities in light of the new federal income tax rate As a result, in 2017 the Corporation’s net deferred tax assets were written down by $6.2 million , with a corresponding increase to income tax expense. The majority of the provisions of the Tax Act became effective on January 1, 2018. The provisions that impact the Corporation include the reduction of the corporate income tax rate from 35% to 21%, changes to the deductibility of certain meals and entertainment expenses, and changes to the deductibility of executive compensation. The Tax Act also accelerated expensing of certain depreciable property for assets placed in service after September 27, 2017 and before January 1, 2023. The following table presents the components of income tax expense: (Dollars in thousands) Years ended December 31, 2018 2017 2016 Current tax expense: Federal $15,460 $23,827 $19,444 State 2,863 2,201 2,061 Total current tax expense 18,323 26,028 21,505 Deferred tax expense (benefit): Federal 63 5,717 796 State (126 ) (30 ) 72 Total deferred tax (benefit) expense (63 ) 5,687 868 Total income tax expense $18,260 $31,715 $22,373 Total income tax expense varies from the amount determined by applying the Federal income tax rate to income before income taxes. The following table presents the reasons for the differences: (Dollars in thousands) 2018 2017 2016 Years ended December 31, Amount Rate Amount Rate Amount Rate Tax expense at Federal statutory rate $18,205 21.0 % $27,174 35.0 % $24,099 35.0 % (Decrease) increase in taxes resulting from: Tax-exempt income, net (809 ) (0.9 ) (1,313 ) (1.7 ) (1,599 ) (2.3 ) Dividends received deduction (45 ) (0.1 ) (55 ) (0.1 ) (58 ) (0.1 ) BOLI (461 ) (0.5 ) (757 ) (0.9 ) (930 ) (1.3 ) Share-based compensation (444 ) (0.5 ) (481 ) (0.6 ) — — Federal tax credits (364 ) (0.4 ) (364 ) (0.5 ) (364 ) (0.5 ) Change in fair value of contingent consideration (39 ) (0.1 ) (225 ) (0.3 ) (314 ) (0.5 ) State income tax expense, net of federal tax benefit 2,162 2.5 1,411 1.8 1,387 2.0 Adjustment to net deferred tax assets for enacted changes in federal tax law — — 6,170 7.9 — — Other 55 0.1 155 0.2 152 0.2 Total income tax expense $18,260 21.1 % $31,715 40.8 % $22,373 32.5 % The following table presents the approximate tax effects of temporary differences that give rise to deferred tax assets and deferred tax liabilities: (Dollars in thousands) December 31, 2018 2017 Deferred tax assets: Allowance for loan losses $6,362 $6,225 Defined benefit pension obligations 420 1,767 Deferred compensation 3,688 3,334 Deferred loan origination fees 1,410 1,325 Share-based compensation 1,124 1,240 Net unrealized losses on securities available for sale 5,149 2,314 Other 1,917 2,281 Deferred tax assets 20,070 18,486 Deferred tax liabilities: Amortization of intangibles (1,918 ) (2,148 ) Deferred loan origination costs (3,897 ) (3,550 ) Loan servicing rights (858 ) (849 ) Other (1,120 ) (1,200 ) Deferred tax liabilities (7,793 ) (7,747 ) Net deferred tax asset $12,277 $10,739 The Corporation’s net deferred tax asset is included in other assets in the Consolidated Balance Sheets. Management has determined that a valuation allowance is not required for any of the deferred tax assets since it is more-likely-than-not that these assets will be realized primarily through future reversals of existing taxable temporary differences or by offsetting projected future taxable income. The Corporation had no unrecognized tax benefits as of December 31, 2018 and 2017 . The Corporation files income tax returns in the U.S. federal jurisdiction and various state jurisdictions. The Corporation is no longer subject to U.S. federal and state income tax examinations by tax authorities for years before 2015 .

Deposits

Deposits	12 Months Ended
	Dec. 31, 2018
Deposits [Abstract]
Deposits	Deposits The following table presents a summary of deposits: (Dollars in thousands) December 31, 2018 2017 Noninterest-bearing demand deposits $603,216 $578,410 Interest-bearing demand deposits 178,733 82,728 NOW accounts 466,568 466,605 Money market accounts 646,878 731,345 Savings accounts 373,545 368,524 Time deposits (1) 1,255,108 1,015,095 Total deposits $3,524,048 $3,242,707 (1) Includes wholesale brokered time deposits. The following table presents scheduled maturities of time certificates of deposit: (Dollars in thousands) Scheduled Maturity Weighted Average Rate Years ending December 31: 2019 $688,862 1.78 % 2020 350,963 2.14 2021 76,248 2.04 2022 102,934 2.43 2023 35,872 1.96 2024 and thereafter 229 1.14 Balance at December 31, 2018 $1,255,108 1.95 % The following table presents the amount of time certificates of deposit in denominations of $100 thousand or more at December 31, 2018 , maturing during the periods indicated: (Dollars in thousands) January 1, 2019 to March 31, 2019 $39,014 April 1, 2019 to June 30, 2019 30,839 July 1, 2019 to December 31, 2019 45,508 January 1, 2020 and beyond 338,214 Balance at December 31, 2018 $453,575 Time certificates of deposit in denominations of $250 thousand or more totaled $129.3 million and $75.1 million , respectively, at December 31, 2018 and 2017 .

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Borrowings	Borrowings Federal Home Loan Bank Advances Advances payable to FHLB amounted to $950.7 million and $791.4 million , respectively, at December 31, 2018 and 2017 . The following table presents maturities and weighted average interest rates on FHLB advances outstanding as of December 31, 2018 : (Dollars in thousands) Scheduled Maturity Weighted Average Rate 2019 $767,258 2.49 % 2020 67,033 2.00 2021 46,222 2.65 2022 55,447 3.65 2023 9,428 4.01 2024 and thereafter 5,334 5.06 Total $950,722 2.56 % As of December 31, 2018 and 2017 , the Bank had access to a $40.0 million unused line of credit with the FHLB and also had remaining available borrowing capacity of $628.5 million and $449.9 million , respectively. The Bank pledges certain qualified investment securities and loans as collateral to the FHLB. Advances payable to FHLB include short-term advances with original maturity due dates of one year or less. The following table presents certain information concerning short-term FHLB advances: (Dollars in thousands) As of and for the years ended December 31, 2018 2017 2016 Average amount outstanding during the period $484,090 $351,692 $275,533 Amount outstanding at end of period 630,000 367,500 352,500 Highest month end balance during period 630,000 417,500 367,500 Weighted-average interest rate at end of period 2.67 % 1.57 % 0.79 % Weighted-average interest rate during the period 2.23 1.20 0.73 Junior Subordinated Debentures Junior subordinated debentures amounted to $22.7 million at December 31, 2018 and 2017 . The Bancorp sponsored the creation of WT Capital Trust I (“Trust I”) and WT Capital Trust II (“Trust II”), Delaware statutory trusts created for the sole purpose of issuing trust preferred securities and investing the proceeds in junior subordinated debentures of the Bancorp. The Bancorp is the owner of all of the common securities of the trusts. In accordance with GAAP, the trusts are treated as unconsolidated subsidiaries. On August 29, 2005, Trust I issued $8.3 million of capital securities (“Trust I Capital Securities”) in a private placement of trust preferred securities. The Trust I Capital Securities mature in September 2035, are redeemable at the Bancorp’s option and require quarterly distributions by Trust I to the holder of the Trust I Capital Securities equal to the three-month LIBOR rate plus 1.45% . The Bancorp has guaranteed the Trust I Capital Securities and, to the extent not paid by Trust I, accrued and unpaid distributions on the Trust I Capital Securities, as well as the redemption price payable to the Trust I Capital Securities holders. The proceeds of the Trust I Capital Securities, along with proceeds from the issuance of common securities by Trust I to the Bancorp, were used to purchase $8.3 million of the Bancorp’s junior subordinated deferrable interest notes (the “Trust I Debentures”) and constitute the primary asset of Trust I. Like the Trust I Capital Securities, the Trust I Debentures bear interest at a rate equal to the three-month LIBOR rate plus 1.45% . The Trust I Debentures mature on September 15, 2035, but may be redeemed at par at the Bancorp’s option, subject to the approval of the applicable banking regulator to the extent required under applicable guidelines or policies. On August 29, 2005, Trust II issued $14.4 million of capital securities (“Trust II Capital Securities”) in a private placement of trust preferred securities. The Trust II Capital Securities mature in November 2035, are redeemable at the Bancorp’s option and require quarterly distributions by Trust II to the holder of the Trust II Capital Securities, at a rate equal to the three-month LIBOR rate plus 1.45% . The Bancorp has guaranteed the Trust II Capital Securities and, to the extent not paid by Trust II, accrued and unpaid distributions on the Trust II Capital Securities, as well as the redemption price payable to the Trust II Capital Securities holders. The proceeds of the Trust II Capital Securities, along with proceeds from the issuance of common securities by Trust II to the Bancorp, were used to purchase $14.4 million of the Bancorp’s junior subordinated deferrable interest notes (the “Trust II Debentures”) and constitute the primary asset of Trust II. Like the Trust II Capital Securities, the Trust II Debentures bear interest at a rate equal to the three-month LIBOR rate plus 1.45% . The Trust II Debentures mature on November 23, 2035, but may be redeemed at par at the Bancorp’s option, subject to the approval of the applicable banking regulator to the extent required under applicable guidelines or policies.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Shareholders' Equity	Shareholders’ Equity 2006 Stock Repurchase Plan In December 2006, the Bancorp’s Board of Directors approved the 2006 Stock Repurchase Plan authorizing the repurchase of up to 400,000 shares, or approximately 3% , of the Corporation’s common stock in open market transactions. This authority may be exercised from time to time and in such amounts as market conditions warrant, and subject to regulatory considerations. When repurchased, shares would be initially classified as treasury stock and then used by the Corporation for general corporate purposes. As of December 31, 2018 , a cumulative total of 185,400 shares have been repurchased, all of which were repurchased in 2007 at a total cost of $4.8 million . Dividends The primary source of liquidity for the Bancorp is dividends received from the Bank. The Bancorp and the Bank are regulated enterprises and their abilities to pay dividends are subject to regulatory review and restriction. Certain regulatory and statutory restrictions exist regarding dividends, loans, and advances from the Bank to the Bancorp. Generally, the Bank has the ability to pay dividends to the Bancorp subject to minimum regulatory capital requirements. The FDIC and the FRB have the authority to use their enforcement powers to prohibit a bank or bank holding company, respectively, from paying dividends if, in their opinion, the payment of dividends would constitute an unsafe or unsound practice. Under the most restrictive of these requirements, the Bank could have declared aggregate additional dividends of $233.0 million as of December 31, 2018 . Reserved Shares As of December 31, 2018 , a total of 1,804,163 common stock shares were reserved for issuance under the 2003 Stock Incentive Plan and the 2013 Stock Option and Incentive Plan. Regulatory Capital Requirements The Bancorp and the Bank are subject to various regulatory capital requirements administered by the FRB and the FDIC, respectively. Regulatory authorities can initiate certain mandatory actions if Bancorp or the Bank fail to meet minimum capital requirements, which could have a direct material effect on the Corporation’s financial statements. Capital adequacy guidelines and, additionally for banks, prompt corrective action regulations involve quantitative measures of assets, liabilities, and certain off-balance sheet items calculated under regulatory accounting practices. These quantitative measures, to ensure capital adequacy, require minimum amounts and ratios. Capital levels at December 31, 2018 exceeded the regulatory minimum levels to be considered “well capitalized.” The following table presents the Corporation’s and the Bank’s actual capital amounts and ratios, as well as the corresponding minimum and well capitalized regulatory amounts and ratios that were in effect during the respective periods: (Dollars in thousands) Actual For Capital Adequacy Purposes To Be “Well Capitalized” Under Prompt Corrective Action Regulations Amount Ratio Amount Ratio Amount Ratio December 31, 2018 Total Capital (to Risk-Weighted Assets): Corporation $455,699 12.56 % $290,146 8.00 % N/A N/A Bank 453,033 12.49 290,128 8.00 $362,660 10.00 % Tier 1 Capital (to Risk-Weighted Assets): Corporation 428,338 11.81 217,609 6.00 N/A N/A Bank 425,672 11.74 217,596 6.00 290,128 8.00 Common Equity Tier 1 Capital (to Risk-Weighted Assets): Corporation 406,340 11.20 163,207 4.50 N/A N/A Bank 425,672 11.74 163,197 4.50 235,729 6.50 Tier 1 Capital (to Average Assets): (1) Corporation 428,338 8.89 192,690 4.00 N/A N/A Bank 425,672 8.84 192,652 4.00 240,815 5.00 December 31, 2017 Total Capital (to Risk-Weighted Assets): Corporation 416,038 12.45 267,365 8.00 N/A N/A Bank 413,593 12.38 267,338 8.00 334,172 10.00 Tier 1 Capital (to Risk-Weighted Assets): Corporation 389,289 11.65 200,524 6.00 N/A N/A Bank 386,844 11.58 200,503 6.00 267,338 8.00 Common Equity Tier 1 Capital (to Risk-Weighted Assets): Corporation 367,291 10.99 150,383 4.50 N/A N/A Bank 386,844 11.58 150,378 4.50 217,212 6.50 Tier 1 Capital (to Average Assets): (1) Corporation 389,289 8.79 177,089 4.00 N/A N/A Bank 386,844 8.74 177,048 4.00 221,310 5.00 (1) Leverage ratio. In addition to the minimum regulatory capital required for capital adequacy purposes included in the table above, the Corporation is required to maintain a minimum capital conservation buffer, in the form of common equity, in order to avoid restrictions on capital distributions and discretionary bonuses. The required amount of the capital conservation buffer was 1.25% on January 1, 2017 and 1.875% on January 1, 2018. The capital conservation buffer increased another 0.625% on January 1, 2019, reaching the full requirement of 2.50%. The Bancorp owns the common stock of two capital trusts, which have issued trust preferred securities. In accordance with GAAP, the capital trusts are treated as unconsolidated subsidiaries. At both December 31, 2018 and 2017, $22.0 million in trust preferred securities were included in the Tier 1 Capital of the Corporation for regulatory capital reporting purposes pursuant to the Federal Reserve’s capital adequacy guidelines.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments The Corporation’s derivative financial instruments are used to manage differences in the amount, timing and duration of the Corporation’s known or expected cash receipts and its known or expected cash payments principally to manage the Corporation’s interest rate risk. Additionally, the Corporation enters into interest rate derivatives to accommodate the business requirements of its customers. All derivatives are recognized as either assets or liabilities on the balance sheet and are measured at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative and resulting designation. Interest Rate Risk Management Agreements Interest rate risk management agreements, such as caps, swaps, and floors, are used from time to time as part of the Corporation’s interest rate risk management strategy. Interest rate swaps are agreements in which the Corporation and another party agree to exchange interest payments (e.g., fixed-rate for variable-rate payments) computed on a notional principal amount. Interest rate caps and floors represent options purchased by the Corporation to manage the interest rate paid throughout the term of the option contract. The credit risk associated with these transactions is the risk of default by the counterparty. To minimize this risk, the Corporation enters into interest rate agreements only with highly rated counterparties that management believes to be creditworthy. The notional amounts of these agreements do not represent amounts exchanged by the parties and, thus, are not a measure of the potential loss exposure. Cash Flow Hedging Instruments As of December 31, 2018 and 2017 , the Bancorp had two interest rate caps with a total notional amount of $22.7 million that were designated as cash flow hedges to hedge the interest rate risk associated with variable rate junior subordinated debentures. For both interest rate caps, the Bancorp obtained the right to receive the difference between 3-month LIBOR and a 4.5% strike. The caps mature in 2020. As of December 31, 2018 and 2017 , the Bank had two interest rate swap contracts with a total notional amount of $60.0 million that were designated as cash flow hedges to hedge the interest rate risk associated with short-term variable rate FHLB advances. The interest rate swaps mature in 2021 and 2023. As of December 31, 2018 and 2017 , the Bank had three interest rate floor contracts with a total notional amount of $300.0 million that were designated as cash flow hedges to hedge the interest rate risk associated with a pool of variable rate commercial loans. The Bank obtained the right to receive the difference between 1-month LIBOR and a 1.0% strike for each of the interest rate floors. The floors mature in 2020. The effective portion of the changes in fair value of derivatives designated as cash flow hedges is recorded in other comprehensive income and subsequently reclassified to earnings when gains or losses are realized. The ineffective portion of changes in fair value of the derivatives is recognized directly in earnings. For the years ended December 31, 2018 and 2017 , there was no ineffective portion of changes in fair value recorded in earnings. Loan Related Derivative Contracts Interest Rate Swap Contracts with Customers The Corporation has entered into interest rate swap contracts to help commercial loan borrowers manage their interest rate risk. The interest rate swap contracts with commercial loan borrowers allow them to convert variable-rate loan payments to fixed-rate loan payments. When we enter into an interest rate swap contract with a commercial loan borrower, we simultaneously enter into a “mirror” swap contract with a third party. The third party exchanges the client’s fixed-rate loan payments for variable-rate loan payments. We retain the risk that is associated with the potential failure of counterparties and the risk inherent in originating loans. As of December 31, 2018 and 2017 , Washington Trust had interest rate swap contracts with commercial loan borrowers with notional amounts of $648.0 million and $545.0 million , respectively, and equal amounts of “mirror” swap contracts with third-party financial institutions. These derivatives are not designated as hedges and therefore, changes in fair value are recognized in earnings. Risk Participation Agreements The Corporation has entered into risk participation agreements with other banks in commercial loan arrangements. Participating banks guarantee the performance on borrower-related interest rate swap contracts. These derivatives are not designated as hedges and therefore, changes in fair value are recognized in earnings. Under a risk participation-out agreement, a derivative asset, the Corporation participates out a portion of the credit risk associated with the interest rate swap position executed with the commercial borrower for a fee paid to the participating bank. Under a risk participation-in agreement, a derivative liability, the Corporation assumes, or participates in, a portion of the credit risk associated with the interest rate swap position with the commercial borrower for a fee received from the other bank. As of December 31, 2018 , the notional amounts of the risk participation-out agreements and risk participation-in agreements were $57.3 million and $46.5 million , respectively, compared to $52.4 million and $34.1 million , respectively, as of December 31, 2017 . Foreign Exchange Contracts Foreign exchange contracts represent contractual commitments to buy or sell a foreign currency on a future date at a specified price. The Corporation uses these foreign exchange contracts on a limited basis to reduce its exposure to fluctuations in currency exchange rates associated with a commercial loan that is denominated in a foreign currency. These derivatives are not designated as hedges and therefore changes in fair value are recognized in earnings. The changes in fair value on the foreign exchange contracts substantially offset the foreign currency translation gains and losses on the related commercial loan. As of December 31, 2018 and 2017 , the notional amount of foreign exchange contracts was $2.8 million and $3.0 million , respectively. Loan Commitments Interest rate lock commitments are extended to borrowers and relate to the origination of mortgage loans held for sale. To mitigate the interest rate risk and pricing risk associated with rate locks and mortgage loans held for sale, the Corporation enters into forward sale commitments. Forward sale commitments are contracts for delayed delivery or net settlement of the underlying instrument, such as a residential real estate mortgage loan, where the seller agrees to deliver on a specified future date, either a specified instrument at a specified price or yield or the net cash equivalent of an underlying instrument. Both interest rate lock commitments and forward sale commitments are derivative financial instruments, but do not meet criteria for hedge accounting and therefore, the changes in fair value of these commitments are reflected in earnings. As of December 31, 2018 , the notional amounts of interest rate lock commitments and forward sale commitments were $30.8 million and $62.0 million , respectively, compared to $45.1 million and $71.5 million , respectively, as of December 31, 2017 . The following table presents the fair values of derivative instruments in the Corporation’s Consolidated Balance Sheets: (Dollars in thousands) Asset Derivatives Liability Derivatives Fair Value Fair Value Balance Sheet Location Dec 31, Dec 31, Balance Sheet Location Dec 31, Dec 31, Derivatives Designated as Cash Flow Hedging Instruments: Interest rate risk management contracts: Interest rate caps Other assets $20 $25 Other liabilities $— $— Interest rate swaps Other assets 903 213 Other liabilities — 14 Interest rate floors Other assets 37 110 Other liabilities — — Derivatives not Designated as Hedging Instruments: Loan related derivative contracts: Interest rate swaps with customers Other assets — 268 Other liabilities 2,379 1,295 Mirror swaps with counterparties Other assets 2,200 1,152 Other liabilities — 268 Risk participation agreements Other assets — — Other liabilities — — Foreign exchange contracts Other assets — — Other liabilities 7 26 Forward loan commitments: Interest rate lock commitments Other assets 806 965 Other liabilities — 20 Forward sale commitments Other assets — 26 Other liabilities 816 1,424 Total $3,966 $2,759 $3,202 $3,047 The following tables present the effect of derivative instruments in the Corporation’s Consolidated Statements of Changes in Shareholders’ Equity and Consolidated Statements of Income: (Dollars in thousands) Gain (Loss) Recognized in Other Comprehensive Income, Net of Tax (Effective Portion) Years ended December 31, 2018 2017 2016 Derivatives Designated as Cash Flow Hedging Instruments: Interest rate risk management contracts: Interest rate caps $30 ($64 ) ($33 ) Interest rate swaps 515 358 (224 ) Interest rate floors 74 (346 ) — Total $619 ($52 ) ($257 ) (Dollars in thousands) Amount of Gain (Loss) Recognized in Income on Derivatives Years ended December 31, Statement of Income Location 2018 2017 2016 Derivatives not Designated as Hedging Instruments: Loan related derivative contracts: Interest rate swaps with customers Loan related derivative income ($290 ) $2,243 ($598 ) Mirror swaps with counterparties Loan related derivative income 2,709 1,198 3,854 Risk participation agreements Loan related derivative income (27 ) (233 ) (13 ) Foreign exchange contracts Loan related derivative income 69 6 — Forward loan commitments: Interest rate lock commitments Mortgage banking revenues (139 ) (100 ) (175 ) Forward sale commitments Mortgage banking revenues 997 (328 ) 942 Total $3,319 $2,786 $4,010

Balance Sheet Offsetting

Balance Sheet Offsetting	12 Months Ended
	Dec. 31, 2018
Balance Sheet Offsetting [Abstract]
Balance Sheet Offsetting	Balance Sheet Offsetting The interest rate risk management contracts and loan related derivative contracts with counterparties are subject to master netting agreements. The following table presents the Corporation’s derivative asset and derivative liability positions and the effect of netting arrangements on the Consolidated Balance Sheets: (Dollars in thousands) December 31, 2018 December 31, 2017 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Derivatives Designated as Cash Flow Hedging Instruments: Interest rate risk management contracts: Interest rate caps $20 $— $25 $— Interest rate swaps 903 — 213 14 Interest rate floors 37 — 110 — Derivatives not Designated as Hedging Instruments: Loan related derivative contracts: Interest rate swaps with customers 5,340 7,719 2,857 3,884 Mirror swaps with counterparties 7,592 5,392 3,801 2,917 Foreign exchange contracts — 7 — 26 Gross amounts 13,892 13,118 7,006 6,841 Less amounts offset in Consolidated Balance Sheets 10,732 10,732 5,238 5,238 Net amounts presented in Consolidated Balance Sheets 3,160 2,386 1,768 1,603 Less collateral pledged (1) — 1,460 — 1,039 Net amounts $3,160 $926 $1,768 $564 (1) Collateral pledged to derivative counterparties in the form of cash. Washington Trust may need to post additional collateral in the future in proportion to potential increases in unrealized loss positions.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Corporation uses fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. Items recorded at fair value on a recurring basis include securities available for sale, mortgage loans held for sale and derivatives. Additionally, from time to time, we may be required to record at fair value other assets on a nonrecurring basis, such as collateral dependent impaired loans, property acquired through foreclosure or repossession and mortgage servicing rights. These nonrecurring fair value adjustments typically involve the application of lower of cost or market accounting or write-downs of individual assets. Fair value is a market-based measurement, not an entity-specific measurement. Fair value measurements are determined based on the assumptions the market participants would use in pricing the asset or liability. In addition, GAAP specifies a hierarchy of valuation techniques based on whether the types of valuation information (“inputs”) are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Corporation’s market assumptions. These two types of inputs have created the following fair value hierarchy: • Level 1 – Quoted prices for identical assets or liabilities in active markets. • Level 2 – Quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in inactive markets; and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets. • Level 3 – Valuations derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable in the markets and which reflect the Corporation’s market assumptions. Fair Value Option Election GAAP allows for the irrevocable option to elect fair value accounting for the initial and subsequent measurement for certain financial assets and liabilities on a contract-by-contract basis. The Corporation has elected the fair value option for mortgage loans held for sale to better match changes in fair value of the loans with changes in the fair value of the forward sale commitment contracts used to economically hedge them. The following table presents a summary of mortgage loans held for sale accounted for under the fair value option: (Dollars in thousands) December 31, 2018 2017 Aggregate fair value $20,996 $26,943 Aggregate principal balance 20,498 26,400 Difference between fair value and principal balance $498 $543 Changes in fair value of mortgage loans held for sale accounted for under the fair value option election amounted to a decrease of $45 thousand in 2018 , compared to an increase of $503 thousand for 2017 . These amounts were partially offset in earnings by the changes in fair value of forward sale commitments used to economically hedge them. The changes in fair value are reported as a component of mortgage banking revenues in the Consolidated Statements of Income. There were no mortgage loans held for sale 90 days or more past due as of December 31, 2018 and 2017 . Valuation Techniques Securities Securities available for sale are recorded at fair value on a recurring basis. When available, the Corporation uses quoted market prices to determine the fair value of securities; such items are classified as Level 1. There were no Level 1 securities held at December 31, 2018 and 2017 . Level 2 securities include debt securities with quoted prices, which are traded less frequently than exchange-traded instruments. The fair value of these securities is determined using matrix pricing with inputs that are observable in the market or can be derived principally from or corroborated by observable market data. This category includes obligations of U.S. government-sponsored enterprises, including mortgage-backed securities, obligations of states and political subdivisions, individual name issuer trust preferred debt securities and corporate bonds. Securities not actively traded whose fair value is determined through the use of cash flows utilizing inputs that are unobservable are classified as Level 3. There were no Level 3 securities held at December 31, 2018 and 2017 . Mortgage Loans Held for Sale The fair value of mortgage loans held for sale is estimated based on current market prices for similar loans in the secondary market and therefore are classified as Level 2 assets. Collateral Dependent Impaired Loans The fair value of collateral dependent loans that are deemed to be impaired is determined based upon the fair value of the underlying collateral. Such collateral primarily consists of real estate and, to a lesser extent, other business assets. For collateral dependent loans for which repayment is dependent on the sale of the collateral, management adjusts the fair value for estimated costs to sell. For collateral dependent loans for which repayment is dependent on the operation of the collateral, such as accruing troubled debt restructured loans, estimated costs to sell are not incorporated into the measurement. Management may also adjust appraised values to reflect estimated market value declines or apply other discounts to appraised values resulting from its knowledge of the property. Internal valuations are utilized to determine the fair value of other business assets. Collateral dependent impaired loans are categorized as Level 3. Property Acquired Through Foreclosure or Repossession Property acquired through foreclosure or repossession included in other assets in the Consolidated Balance Sheets is adjusted to fair value less costs to sell upon transfer out of loans through a charge to allowance for loan losses. Subsequently, it is carried at the lower of carrying value or fair value less costs to sell. Such subsequent valuation charges are charged through earnings. Fair value is generally based upon appraised values of the collateral. Management may adjust appraised values to reflect estimated market value declines or apply other discounts to appraised values for unobservable factors resulting from its knowledge of the property, and such property is categorized as Level 3. Derivatives Interest rate cap, swap and floor contracts are traded in over-the-counter markets where quoted market prices are not readily available. Fair value measurements are determined using independent pricing models that utilize primarily market observable inputs, such as swap rates of different maturities and LIBOR rates. The Corporation also evaluates the credit risk of its counterparties as well as that of the Corporation. Accordingly, factors such as the likelihood of default by the Corporation and its counterparties, its net exposures and remaining contractual life are considered in determining if any fair value adjustments related to credit risk are required. Counterparty exposure is evaluated by netting positions that are subject to master netting agreements, as well as considering the amount of collateral securing the position, if any. Although the Corporation has determined that the majority of the inputs used to value its interest rate swap, cap and floor contracts fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with interest rate contracts and risk participation agreements utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by the Corporation and its counterparties. However, as of December 31, 2018 and 2017 , the Corporation has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivatives. As a result, the Corporation has classified its derivative valuations in their entirety as Level 2. Fair value measurements of forward loan commitments (interest rate lock commitments and forward sale commitments) are primarily based on current market prices for similar assets in the secondary market for mortgage loans and therefore are classified as Level 2 assets. The fair value of interest rate lock commitments is also dependent on the ultimate closing of the loans. Pull-through rates are based on the Corporation’s historical data and reflect the Corporation’s best estimate of the likelihood that a commitment will result in a closed loan. Although the pull-through rates are Level 3 inputs, the Corporation has assessed the significance of the impact of pull-through rates on the overall valuation of its interest rate lock commitments and has determined that they are not significant to the overall valuation. As a result, the Corporation has classified its interest rate lock commitments as Level 2. Contingent Consideration Liability A contingent consideration liability was recognized upon the completion of the Halsey acquisition on August 1, 2015 representing the estimated present value of future earn-outs to be paid based on the future revenue growth of the acquired business during the five -year period following the acquisition. The fair value measurement was based upon unobservable inputs, therefore, the contingent liability was classified within Level 3 of the fair value hierarchy. The unobservable inputs included probability estimates regarding the likelihood of achieving revenue growth targets and the discount rates utilized the discounted cash flow calculations applied to the estimated earn-outs to be paid. The contingent consideration liability was remeasured to fair value at each reporting period taking into consideration changes in those unobservable inputs. Changes in the fair value of the contingent consideration liability were included in noninterest expenses in the Consolidated Statements of Income. One of the two earn-out periods associated with this contingent consideration liability ended December 31, 2017 and a payment of $1.2 million was made by the Corporation in the first quarter of 2018. The likelihood of payout on the remaining earn-out period has been deemed remote. As a result, a change in fair value of $187 thousand was recorded as a reduction to other expenses in 2018 and the current carrying value of the contingent consideration liability was reduced to zero . Items Recorded at Fair Value on a Recurring Basis The following tables present the balances of assets and liabilities reported at fair value on a recurring basis: (Dollars in thousands) Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs (Level 3) December 31, 2018 Assets: Securities available for sale: Obligations of U.S. government-sponsored enterprises $242,683 $— $242,683 $— Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises 660,793 — 660,793 — Obligations of states and political subdivisions 937 — 937 — Individual name issuer trust preferred debt securities 11,772 — 11,772 — Corporate bonds 11,625 — 11,625 — Mortgage loans held for sale 20,996 — 20,996 — Derivative assets 3,966 — 3,966 — Total assets at fair value on a recurring basis $952,772 $— $952,772 $— Liabilities: Derivative liabilities $3,202 $— $3,202 $— Total liabilities at fair value on a recurring basis $3,202 $— $3,202 $— (Dollars in thousands) Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs (Level 3) December 31, 2017 Assets: Securities available for sale: Obligations of U.S. government-sponsored enterprises $157,604 $— $157,604 $— Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises 590,882 — 590,882 — Obligations of states and political subdivisions 2,359 — 2,359 — Individual name issuer trust preferred debt securities 16,984 — 16,984 — Corporate bonds 13,125 — 13,125 — Mortgage loans held for sale 26,943 — 26,943 — Derivative assets 2,759 — 2,759 — Total assets at fair value on a recurring basis $810,656 $— $810,656 $— Liabilities: Derivative liabilities $3,047 $— $3,047 $— Contingent consideration liability 1,404 — — 1,404 Total liabilities at fair value on a recurring basis $4,451 $— $3,047 $1,404 It is the Corporation’s policy to review and reflect transfers between Levels as of the financial statement reporting date. There were no transfers in and/or out of Level 1, 2 or 3 during the years ended December 31, 2018 and 2017 . The contingent consideration liability is a Level 3 liability remeasured at fair value on a recurring basis. The following table presents the change in the contingent consideration liability, which is included in other liabilities in the Consolidated Balance Sheets. (Dollars in thousands) Years ended December 31, 2018 2017 Beginning Balance $1,404 $2,047 Change in fair value (187 ) (643 ) Payments (1,217 ) — Ending Balance $— $1,404 Items Recorded at Fair Value on a Nonrecurring Basis The following table presents the carrying value of assets held at December 31, 2018 , which were written down to fair value during the year ended December 31, 2018 : (Dollars in thousands) Total Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Assets: Collateral dependent impaired loans $883 $— $— $883 Property acquired through foreclosure or repossession 2,142 — — 2,142 Total assets at fair value on a nonrecurring basis $3,025 $— $— $3,025 The allowance for loan losses on collateral dependent impaired loans amounted to $24 thousand at December 31, 2018 . The following table presents the carrying value of assets held at December 31, 2017 , which were written down to fair value during the year ended December 31, 2017 : (Dollars in thousands) Total Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Assets: Collateral dependent impaired loans $1,425 $— $— $1,425 Property acquired through foreclosure or repossession 131 — — 131 Total assets at fair value on a nonrecurring basis $1,556 $— $— $1,556 The allowance for loan losses on collateral dependent impaired loans amounted to $690 thousand at December 31, 2017 . The following tables present valuation techniques and unobservable inputs for assets measured at fair value on a nonrecurring basis for which the Corporation has utilized Level 3 inputs to determine fair value: (Dollars in thousands) Fair Value Valuation Technique Unobservable Input Range of Inputs Utilized (Weighted Average) December 31, 2018 Collateral dependent impaired loans $883 Appraisals of collateral Discount for costs to sell 0% - 10% (10%) Appraisal adjustments (1) 0% - 100% (2%) Property acquired through foreclosure or repossession 2,142 Appraisals of collateral Discount for costs to sell 13% Appraisal adjustments (1) 12% - 28% (20%) (1) Management may adjust appraisal values to reflect market value declines or other discounts resulting from its knowledge of the property. (Dollars in thousands) Fair Value Valuation Technique Unobservable Input Range of Inputs Utilized (Weighted Average) December 31, 2017 Collateral dependent impaired loans $1,425 Appraisals of collateral Discount for costs to sell 0% - 15% (15%) Property acquired through foreclosure or repossession 131 Appraisals of collateral Discount for costs to sell 10% Appraisal adjustments (1) 12% - 17% (15%) (1) Management may adjust appraisal values to reflect market value declines or other discounts resulting from its knowledge of the property. Valuation of Financial Instruments The estimated fair values and related carrying amounts for financial instruments for which fair value is only disclosed are presented below as of the periods indicated. The tables exclude financial instruments for which the carrying value approximates fair value such as cash and cash equivalents, FHLB stock, accrued interest receivable, bank-owned life insurance, non-maturity deposits and accrued interest payable. (Dollars in thousands) Carrying Amount Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs (Level 3) December 31, 2018 Financial Assets: Securities held to maturity $10,415 $10,316 $— $10,316 $— Loans, net of allowance for loan losses 3,653,288 3,598,025 — — 3,598,025 Financial Liabilities: Time deposits $1,255,108 $1,269,433 $— $1,269,433 $— FHLB advances 950,722 950,691 — 950,691 — Junior subordinated debentures 22,681 19,226 — 19,226 — (Dollars in thousands) Carrying Amount Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs (Level 3) December 31, 2017 Financial Assets: Securities held to maturity $12,541 $12,721 $— $12,721 $— Loans, net of allowance for loan losses 3,347,583 3,369,932 — — 3,369,932 Financial Liabilities: Time deposits $1,015,095 $1,018,396 $— $1,018,396 $— FHLB advances 791,356 792,887 — 792,887 — Junior subordinated debentures 22,681 18,559 — 18,559 —

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Revenue from Contracts with Customers The following table summarizes total revenues as presented in the Consolidated Statements of Income and the related amounts which are from contracts with customers within the scope of Topic 606. As shown below, a substantial portion of our revenues are specifically excluded from the scope of Topic 606. Years ended December 31, 2018 2017 2016 (Dollars in thousands) As reported in Consolidated Statements of Income Revenue from contracts in scope of Topic 606 As reported in Consolidated Statements of Income Revenue from contracts in scope of Topic 606 As reported in Consolidated Statements of Income Revenue from contracts in scope of Topic 606 Net interest income $132,290 $— $119,531 $— $110,478 $— Noninterest income: Asset-based wealth management revenues 37,343 37,343 38,125 38,125 36,139 36,139 Transaction-based wealth management revenues 998 998 1,221 1,221 1,430 1,430 Total wealth management revenues 38,341 38,341 39,346 39,346 37,569 37,569 Mortgage banking revenues 10,381 — 11,392 — 13,183 — Service charges on deposit accounts 3,628 3,628 3,672 3,672 3,702 3,702 Card interchange fees 3,768 3,768 3,502 3,502 3,385 3,385 Income from bank-owned life insurance 2,196 — 2,161 — 2,659 — Loan related derivative income 2,461 — 3,214 — 3,243 — Other income 1,339 1,329 1,522 1,469 1,388 1,388 Total noninterest income 62,114 47,066 64,809 47,989 65,129 46,044 Total revenues $194,404 $47,066 $184,340 $47,989 $175,607 $46,044 The following table presents revenue from contracts with customers based on the timing of revenue recognition: (Dollars in thousands) Years ended December 31, 2018 2017 2016 Revenue recognized at a point in time: Card interchange fees $3,768 $3,502 $3,385 Service charges on deposit accounts 2,802 2,899 2,914 Other income 958 1,122 1,062 Revenue recognized over time: Wealth management revenues 38,341 39,346 37,569 Service charges on deposit accounts 826 773 788 Other income 371 347 326 Total revenues from contracts in scope of Topic 606 $47,066 $47,989 $46,044 Receivables primarily consist of amounts due from customers for wealth management services performed for which the Corporation’s performance obligations have been fully satisfied. Receivables amounted to $4.8 million and $5.7 million , respectively, at December 31, 2018 and 2017 and were included in other assets in the Consolidated Balance Sheets. Deferred revenues, which are considered contract liabilities under Topic 606, represent advance consideration received from customers for which the Corporation has a remaining performance obligation to fulfill. Contract liabilities are recognized as revenue over the life of the contract as the performance obligations are satisfied. The balances of contract liabilities were insignificant at both December 31, 2018 and 2017 and were included in other liabilities in the Consolidated Balance Sheets. For commissions and incentives that are in-scope of Topic 606, such as those paid to employees in our wealth management services and commercial banking segments in order to obtain customer contracts, contract cost assets are established. The contract cost assets are capitalized and amortized over the estimated useful life that the asset is expected to generate benefits. The carrying value of contract cost assets at December 31, 2018 amounted to $458 thousand and were included in other assets in the Consolidated Balance Sheets.

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Employee Benefits	Employee Benefits Defined Benefit Pension Plans Washington Trust maintains a qualified pension plan for the benefit of certain eligible employees who were hired prior to October 1, 2007. Washington Trust also has non-qualified retirement plans to provide supplemental retirement benefits to certain employees, as defined in the plans. The defined benefit pension plans were previously amended to freeze benefit accruals after a 10 -year transition period ending in December 2023. The qualified pension plan is funded on a current basis, in compliance with the requirements of ERISA. Pension benefit costs and benefit obligations incorporate various actuarial and other assumptions, including discount rates, mortality, rates of return on plan assets and compensation increases. Washington Trust evaluates these assumptions annually. The following table presents the plans’ projected benefit obligations, fair value of plan assets and funded (unfunded) status: (Dollars in thousands) Qualified Pension Plan Non-Qualified Retirement Plans At December 31, 2018 2017 2018 2017 Change in Benefit Obligation: Benefit obligation at beginning of period $80,723 $72,951 $15,203 $13,154 Service cost 2,244 2,149 108 129 Interest cost 2,715 2,673 475 428 Actuarial (gain) loss (7,830 ) 7,017 (252 ) 2,275 Benefits paid (4,344 ) (3,936 ) (908 ) (783 ) Administrative expenses (128 ) (131 ) — — Benefit obligation at end of period 73,380 80,723 14,626 15,203 Change in Plan Assets: Fair value of plan assets at beginning of period 87,364 75,787 — — Actual return on plan assets 288 12,644 — — Employer contributions 3,000 3,000 908 783 Benefits paid (4,344 ) (3,936 ) (908 ) (783 ) Administrative expenses (128 ) (131 ) — — Fair value of plan assets at end of period 86,180 87,364 — — Funded (unfunded) status at end of period $12,800 $6,641 ($14,626 ) ($15,203 ) As of December 31, 2018 and 2017 , the funded status of the qualified defined benefit pension plan amounted to $12.8 million and $6.6 million , respectively, and was included in other assets in the Consolidated Balance Sheets. The unfunded status of the non-qualified defined benefit retirement plans was $14.6 million and $15.2 million , respectively, at December 31, 2018 and December 31, 2017 and was included in other liabilities in the Consolidated Balance Sheets. The non-qualified retirement plans provide for the designation of assets in rabbi trusts. Securities available for sale and other short-term investments designated for this purpose, with the carrying value of $14.6 million and $13.3 million are included in the Consolidated Balance Sheets at December 31, 2018 and 2017 , respectively. The following table presents components of accumulated other comprehensive income related to the qualified pension plan and non-qualified retirement plans, on a pre-tax basis: (Dollars in thousands) Qualified Pension Plan Non-Qualified Retirement Plans At December 31, 2018 2017 2018 2017 Net actuarial loss $9,453 $13,795 $5,785 $6,448 Prior service credit (16 ) (39 ) — (1 ) Total pre-tax amounts recognized in accumulated other comprehensive income $9,437 $13,756 $5,785 $6,447 The accumulated benefit obligation for the qualified pension plan was $67.4 million and $72.9 million at December 31, 2018 and 2017 , respectively. The accumulated benefit obligation for the non-qualified retirement plans amounted to $13.2 million and $14.0 million at December 31, 2018 and 2017 , respectively. The following table presents components of net periodic benefit cost and other amounts recognized in other comprehensive income (loss), on a pre-tax basis: (Dollars in thousands) Qualified Pension Plan Non-Qualified Retirement Plans Years ended December 31, 2018 2017 2016 2018 2017 2016 Net Periodic Benefit Cost: Service cost (1) $2,244 $2,149 $2,148 $108 $129 $122 Interest cost (2) 2,715 2,673 2,576 475 428 432 Expected return on plan assets (2) (5,272 ) (4,942 ) (4,633 ) — — — Amortization of prior service credit (2) (23 ) (23 ) (23 ) (1 ) (1 ) (1 ) Recognized net actuarial loss (2) 1,496 1,114 828 411 347 247 Net periodic benefit cost 1,160 971 896 993 903 800 Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (on a pre-tax basis): Net (gain) loss (4,342 ) (1,798 ) 2,904 (663 ) 1,928 127 Prior service cost 23 23 23 1 1 1 Recognized in other comprehensive (loss) income (4,319 ) (1,775 ) 2,927 (662 ) 1,929 128 Total recognized in net periodic benefit cost and other comprehensive (loss) income ($3,159 ) ($804 ) $3,823 $331 $2,832 $928 (1) Included in salaries and employee benefits expense in the Consolidated Statements of Income. (2) Included in other expenses in the Consolidated Statements of Income. For the qualified pension plan, an estimated prior service credit of $16 thousand and net losses of $792 thousand will be amortized from accumulated other comprehensive income (loss) into net periodic benefit cost during the year 2019 . For the non-qualified retirement plans, net losses of $408 thousand will be amortized from accumulated other comprehensive income (loss) into net periodic benefit cost during the year 2019 . There are no estimated prior service credits to be amortized in 2019 for the non-qualified retirement plans. Assumptions The following table presents the measurement date and weighted-average assumptions used to determine benefit obligations at December 31, 2018 and 2017 : Qualified Pension Plan Non-Qualified Retirement Plans 2018 2017 2018 2017 Measurement date Dec 31, 2018 Dec 31, 2017 Dec 31, 2018 Dec 31, 2017 Discount rate 4.38% 3.69% 4.30% 3.60% Rate of compensation increase 3.75 3.75 3.75 3.75 The following table presents the measurement date and weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31, 2018 , 2017 and 2016 : Qualified Pension Plan Non-Qualified Retirement Plans 2018 2017 2016 2018 2017 2016 Measurement date Dec 31, 2017 Dec 31, 2016 Dec 31, 2015 Dec 31, 2017 Dec 31, 2016 Dec 31, 2015 Equivalent single discount rate for benefit obligations 3.69% 4.18% 4.48% 3.58% 3.96% 4.20% Equivalent single discount rate for service cost 3.76 4.29 4.63 3.79 4.25 4.59 Equivalent single discount rate for interest cost 3.42 3.73 3.88 3.22 3.36 3.44 Expected long-term return on plan assets 6.75 6.75 6.75 N/A N/A N/A Rate of compensation increase 3.75 3.75 3.75 3.75 3.75 3.75 The expected long-term rate of return on plan assets is based on what the Corporation believes is realistically achievable based on the types of assets held by the plan and the plan’s investment practices. The assumption is updated annually, taking into account the asset allocation, historical asset return trends on the types of assets held and the current and expected economic conditions. Future decreases in the long-term rate of return assumption on plan assets would increase pension costs and, in general, may increase the requirement to make funding contributions to the plans. Future increases in the long-term rate of return on plan assets would have the opposite effect. The discount rate assumption for defined benefit pension plans is reset on the measurement date. Discount rates are selected for each plan by matching expected future benefit payments stream to a yield curve based on a selection of high- quality fixed-income debt securities. Future decreases in discount rates would increase the present value of pension obligations and increase our pension costs, while future increases in discount rates would have the opposite effect. The "spot rate approach" was utilized in the calculation of interest and service cost. The spot rate approach applies separate discount rates for each projected benefit payment in the calculation of interest and service cost. This approach provides a more precise measurement of service and interest cost by improving the correlation between projected benefit cash flows and their corresponding spot rates. Plan Assets The following tables present the fair values of the qualified pension plan’s assets: (Dollars in thousands) Fair Value Measurements Using Assets at Fair Value December 31, 2018 Level 1 Level 2 Level 3 Assets: Cash and cash equivalents $25,986 $— $— $25,986 Obligations of U.S. government-sponsored enterprises — 21,787 — 21,787 Obligations of states and political subdivisions — 2,597 — 2,597 Corporate bonds — 10,361 — 10,361 Common stocks 9,957 — — 9,957 Mutual funds 15,492 — — 15,492 Total plan assets $51,435 $34,745 $— $86,180 (Dollars in thousands) Fair Value Measurements Using Assets at Fair Value December 31, 2017 Level 1 Level 2 Level 3 Assets: Cash and cash equivalents $3,760 $— $— $3,760 Obligations of U.S. government-sponsored enterprises — 5,926 — 5,926 Obligations of states and political subdivisions — 2,971 — 2,971 Corporate bonds — 13,112 — 13,112 Common stocks 38,508 — — 38,508 Mutual funds 23,087 — — 23,087 Total plan assets $65,355 $22,009 $— $87,364 The qualified pension plan uses fair value measurements to record fair value adjustments to the securities held in its investment portfolio. When available, the qualified pension plan uses quoted market prices to determine the fair value of securities; such items are classified as Level 1. This category includes cash equivalents, common stocks and mutual funds which are exchange-traded. Level 2 securities in the qualified pension plan include debt securities with quoted prices, which are traded less frequently than exchange-traded instruments, whose values are determined using matrix pricing with inputs that are observable in the market or can be derived principally from or corroborated by observable market data. This category includes obligations of U.S. government-sponsored enterprises, obligations of states and political subdivisions and corporate bonds. In certain cases where there is limited activity or less transparency around inputs to the valuation, securities may be classified as Level 3. As of December 31, 2018 and 2017 , the qualified pension plan did not have any securities in the Level 3 category. The following table presents the asset allocations of the qualified pension plan, by asset category: December 31, 2018 2017 Asset Category: Cash and cash equivalents 30.2 % 4.3 % Fixed income securities 40.3 30.0 Equity securities 29.5 65.7 Total 100.0 % 100.0 % The assets of the qualified defined benefit pension plan trust (the “Pension Trust”) are managed to ensure that all present and future benefit obligations are met as they come due. It seeks to achieve this goal while trying to mitigate volatility in plan funded status, contributions and expense by better matching the characteristics of the plan assets to that of the plan liabilities. As benefit accruals under the qualified plan will be frozen on December 31, 2023, asset allocations have been and will continue to be refined. Cash inflow is typically comprised of investment income from portfolio holdings and Bank contributions, while cash outflow is for the purpose of paying plan benefits and certain plan expenses. As early as possible each year, the trustee is advised of the projected schedule of employer contributions and estimations of benefit payments. The investment philosophy used for the Pension Trust emphasizes consistency of results over an extended market cycle, while reducing the impact of the volatility of the security markets upon investment results. The assets of the Pension Trust should be protected by substantial diversification of investments, providing exposure to a wide range of quality investment opportunities in various asset classes, with a high degree of liquidity. Fixed income bond investments should be limited to those in the top four categories used by the major credit rating agencies. High yield bond funds may be used to provide exposure to this asset class as a diversification tool. In order to reduce the volatility of the annual rate of return of the bond portfolio, attention will be given to the maturity structure of the portfolio in the light of money market conditions and interest rate forecasts. The assets of the Pension Trust will typically have a laddered maturity structure, avoiding large concentrations in any single year. Equity holdings provide opportunities for dividend and capital appreciation returns. Holdings will be appropriately diversified by maintaining broad exposure to large-, mid- and small-cap stocks as well as international equities. Investment selection and mix of equity holdings should be influenced by forecasts of economic activity, corporate profits and allocation among different segments of the economy while ensuring efficient diversification. The fair value of equity securities of any one issuer will not be permitted to exceed 10% of the total fair value of equity holdings of the Pension Trust. Investments in publicly traded real estate investment trust securities and low-risk derivatives securities such as callable securities, variable-rate notes, mortgage-backed securities and treasury inflation protected securities, are permitted. Cash Flows Contributions The Internal Revenue Code permits flexibility in plan contributions so that normally a range of contributions is possible. The Corporation does not expect to make a contribution to the qualified pension plan in 2019 . In addition, the Corporation expects to contribute $907 thousand in benefit payments to the non-qualified retirement plans in 2019 . Estimated Future Benefit Payments The following table presents the benefit payments, which reflect expected future service, as appropriate, expected to be paid: (Dollars in thousands) Qualified Pension Plan Non-Qualified Retirement Plans 2019 $4,034 $907 2020 3,817 898 2021 3,823 886 2022 4,088 878 2023 4,091 878 Years 2024 - 2028 28,295 4,355 401(k) Plan The Corporation’s 401(k) Plan provides a match up to a maximum of 3% of employee contributions for substantially all employees. In addition, substantially all employees hired after September 30, 2007, who are ineligible for participation in the qualified defined benefit pension plan, receive a non-elective employer contribution of 4% of compensation. Total employer matching contributions under this plan amounted to $2.5 million , $2.3 million and $2.3 million in 2018 , 2017 and 2016 , respectively. Other Incentive Plans The Corporation maintains several non-qualified incentive compensation plans. Substantially all employees participate in one of the incentive compensation plans. Incentive plans provide for annual or more frequent payments based on individual, business line and/or corporate performance targets. Total incentive based compensation in 2018 , 2017 and 2016 amounted to $16.1 million , $16.9 million and $16.0 million , respectively. In general, the terms of incentive plans are subject to annual renewal and may be terminated at any time by the Compensation Committee of the Board of Directors. Deferred Compensation Plan The Amended and Restated Nonqualified Deferred Compensation Plan provides supplemental retirement and tax benefits to directors and certain officers. The plan is funded primarily through pre-tax contributions made by the participants. The assets and liabilities of the Deferred Compensation Plan are recorded at fair value in the Corporation’s Consolidated Balance Sheets. The participants in the plan bear the risk of market fluctuations of the underlying assets. The accrued liability related to this plan amounted to $15.7 million and $14.2 million , respectively, at December 31, 2018 and 2017 , and is included in other liabilities on the accompanying Consolidated Balance Sheets. The corresponding invested assets are reported in other assets in the Consolidated Balance Sheets.

Share-Based Compensation Arrang

Share-Based Compensation Arrangements	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation Arrangements	Share-Based Compensation Arrangements Washington Trust’s share-based compensation plans are described below. The 2013 Stock Option and Incentive Plan (the “2013 Plan”) was approved by shareholders on April 23, 2013. Under the 2013 Plan, the maximum number of shares of the Bancorp’s common stock to be issued is 1,748,250 . The 2013 Plan permits the granting of stock options and other equity incentives to officers, employees, directors and other key persons. The 2003 Stock Incentive Plan (the “2003 Plan”) was amended and restated and approved by shareholders in April 2009. Under the 2003 Plan, as amended and restated, the maximum number of shares of Bancorp’s common stock to be issued is 1,200,000 shares and the number of shares that can be issued in the form of awards other than stock options or stock appreciation rights is 400,000 . The 2003 Plan permits the granting of stock options and other equity incentives to officers, employees, directors and other key persons. The exercise price of each stock option may not be less than the fair market value of the Bancorp’s common stock on the date of grant, and options shall have a term of no more than ten years. Stock options are designated as either non-qualified or incentive stock options. In general, the stock option price is payable in cash, by the delivery of shares of common stock already owned by the grantee, or a combination thereof. With respect only to non-qualified stock option grants issued under the 2013 Plan, the exercise may also be accomplished by withholding the exercise price from the number of shares that would otherwise be delivered upon a cash exercise of the option. The fair value of stock options on the date of grant is estimated using the Black-Scholes Option-Pricing Model. Awards of nonvested share units and nonvested performance share units are valued at the fair market value of the Bancorp’s common stock as of the award date. Performance share awards are granted in order to provide certain officers of the Corporation the opportunity to earn shares of common stock, the number of which is determined pursuant to, and subject to the attainment of, performance goals during a specified measurement period. The number of shares earned will range from zero to 200% of the target number of shares dependent upon the Corporation’s core return on equity and core earnings per share growth ranking compared to an industry peer group. Vesting of stock options and share awards may accelerate or may be subject to proportional vesting if there is a change in control, disability, retirement or death (as defined in the 2013 Plan and the 2003 Plan). The following table presents share-based compensation expense and the related income tax benefits recognized in the Consolidated Statements of Income for stock options, nonvested share units and nonvested performance share units: (Dollars in thousands) Years ended December 31, 2018 2017 2016 Share-based compensation expense $2,602 $2,577 $2,190 Related income tax benefits (1) $1,108 $1,114 $810 (1) Includes $496 thousand and $508 thousand , respectively, of excess tax benefits recognized upon the settlement of share-based compensation awards in 2018 and 2017 . See additional disclosure under the heading “Share-Based Compensation” in Note 1 . As of December 31, 2018 , there was $4.4 million of total unrecognized compensation cost related to share-based compensation arrangements, including stock options, nonvested share units and performance share units granted under the Plans. That cost is expected to be recognized over a weighted average period of 2.03 years. Stock Options Washington Trust uses historical data to estimate stock option exercise and employee departure behavior in the option-pricing model. The expected term of options granted was derived from the output of the option valuation model and represents the period of time that options granted are expected to be outstanding. Expected volatility was based on historical volatility of Washington Trust shares. The risk-free rate for periods within the contractual life of the stock option was based on the U.S. Treasury yield curve in effect at the date of grant. The following presents the assumptions used in determining the grant date fair value of the stock option awards granted to certain key employees: 2018 2017 2016 Options granted 47,950 47,725 53,400 Cliff vesting period (years) 3 3 3 Expected term (years) 6.5 7.0 7.5 Expected dividend yield 3.39 % 3.57 % 3.89 % Weighted average expected volatility 22.73 % 27.10 % 29.99 % Weighted average risk-free interest rate 3.14 % 1.70 % 1.66 % Weighted average grant-date fair value $9.74 $10.60 $7.92 The following table presents a summary of the status of Washington Trust’s stock options outstanding as of and for the year ended December 31, 2018 : Number of Stock Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (000’s) Beginning of period 223,853 $38.68 Granted 47,950 54.74 Exercised (29,738 ) 27.57 Forfeited or expired (19,450 ) 46.71 End of period 222,615 $42.92 7.15 $1,790 At end of period: Options exercisable 87,990 $31.18 4.68 $1,439 Options expected to vest in future periods 134,625 $50.60 8.76 $351 The total intrinsic value is the amount by which the fair value of the underlying stock exceeds the exercise price of an option on the exercise date. The following table presents additional information concerning options outstanding and options exercisable at December 31, 2018 : Options Outstanding Options Exercisable Exercise Price Ranges Number of Shares Weighted Average Remaining Life (Years) Weighted Average Exercise Price Number of Shares Weighted Average Exercise Price $15.01 to $20.00 6,900 1.42 $17.52 6,900 $17.52 $20.01 to $25.00 26,040 3.07 23.06 26,040 23.06 $25.01 to $30.00 — — — — — $30.01 to $35.00 22,875 4.98 32.76 22,875 32.76 $35.01 to $40.00 36,175 6.47 39.35 32,175 39.55 $40.01 to $45.00 42,850 7.80 40.25 — — $45.01 to $50.00 — — — — — $50.01 to $55.00 47,950 9.80 54.74 — — $55.01 to $60.00 39,825 8.80 58.05 — — 222,615 7.15 $42.92 87,990 $31.18 The total intrinsic value of stock options exercised during the years ended December 31, 2018 , 2017 and 2016 was $833 thousand , $1.0 million and $3.2 million , respectively. Nonvested Share Units In 2018 , 2017 and 2016 , the Corporation granted to directors and certain key employees 13,430 , 15,900 and 22,175 nonvested share units, respectively, with 3 - to 5 -year cliff vesting. The following table presents a summary of the status of Washington Trust’s nonvested share units as of and for the year ended December 31, 2018 : Number of Shares Weighted Average Grant Date Fair Value Beginning of period 53,775 $43.13 Granted 13,430 55.71 Vested (18,805 ) 37.87 Forfeited (3,050 ) 47.75 End of period 45,350 $48.73 Nonvested Performance Share Units The Corporation granted performance share units to certain executive officers providing the opportunity to earn shares of common stock over a 3 - to 5 -year performance period. The following table presents a summary of the performance share unit awards as of December 31, 2018 : Grant Date Fair Value per Share Current Performance Assumption Expected Number of Shares Performance share units awarded in: 2018 $54.25 140% 41,454 2017 51.85 150% 24,150 2016 36.11 140% 28,000 Total 93,604 The following table presents a summary of the status of Washington Trust’s performance share units as of and for the year ended December 31, 2018 : Number of Shares Weighted Average Grant Date Fair Value Beginning of period 117,465 $41.58 Granted 41,454 54.25 Vested (36,729 ) 38.02 Forfeited (28,586 ) 42.83 End of period 93,604 $48.20

Business Segments

Business Segments	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Business Segments	Business Segments Washington Trust segregates financial information in assessing its results among its Commercial Banking and Wealth Management Services operating segments. The amounts in the Corporate unit include activity not related to the segments. Commercial Banking The Commercial Banking segment includes commercial, residential and consumer lending activities; mortgage banking activities; deposit generation; cash management activities; and direct banking activities, which include the operation of ATMs, telephone and internet banking services and customer support and sales. Wealth Management Services Wealth Management Services includes investment management; financial planning; personal trust and estate services, including services as trustee, personal representative, custodian and guardian; and settlement of decedents’ estates. Institutional trust services are also provided, including fiduciary services. Corporate Corporate includes the Treasury Unit, which is responsible for managing the wholesale investment portfolio and wholesale funding needs. It also includes income from BOLI, as well as administrative and executive expenses not allocated to the operating segments and the residual impact of methodology allocations such as FTP offsets. The following tables present the statement of operations and total assets for Washington Trust’s reportable segments: (Dollars in thousands) Year ended December 31, 2018 Commercial Banking Wealth Management Services Corporate Consolidated Total Net interest income (expense) $106,668 ($334 ) $25,956 $132,290 Provision for loan losses 1,550 — — 1,550 Net interest income (expense) after provision for loan losses 105,118 (334 ) 25,956 130,740 Noninterest income 21,509 38,341 2,264 62,114 Noninterest expenses: Depreciation and amortization expense 2,589 1,501 171 4,261 Other noninterest expenses 62,673 26,222 13,006 101,901 Total noninterest expenses 65,262 27,723 13,177 106,162 Income before income taxes 61,365 10,284 15,043 86,692 Income tax expense 13,149 2,577 2,534 18,260 Net income $48,216 $7,707 $12,509 $68,432 Total assets at period end $3,804,021 $71,254 $1,135,491 $5,010,766 Expenditures for long-lived assets 3,415 407 152 3,974 (Dollars in thousands) Year ended December 31, 2017 Commercial Banking Wealth Management Services Corporate Consolidated Total Net interest income (expense) $98,736 ($167 ) $20,962 $119,531 Provision for loan losses 2,600 — — 2,600 Net interest income (expense) after provision for loan losses 96,136 (167 ) 20,962 116,931 Noninterest income 23,244 39,346 2,219 64,809 Noninterest expenses: Depreciation and amortization expense 2,604 1,689 196 4,489 Other noninterest expenses 60,828 26,718 12,065 99,611 Total noninterest expenses 63,432 28,407 12,261 104,100 Income before income taxes 55,948 10,772 10,920 77,640 Income tax expense 23,876 3,795 4,044 31,715 Net income $32,072 $6,977 $6,876 $45,925 Total assets at period end $3,491,845 $66,083 $971,922 $4,529,850 Expenditures for long-lived assets 2,224 360 195 2,779 (Dollars in thousands) Year ended December 31, 2016 Commercial Banking Wealth Management Services Corporate Consolidated Total Net interest income $91,221 ($66 ) $19,323 $110,478 Provision for loan losses 5,650 — — 5,650 Net interest income (expense) after provision for loan losses 85,571 (66 ) 19,323 104,828 Noninterest income 24,783 37,569 2,777 65,129 Noninterest expenses: Depreciation and amortization expense 2,771 1,940 224 4,935 Other noninterest expenses 58,452 25,239 12,477 96,168 Total noninterest expenses 61,223 27,179 12,701 101,103 Income before income taxes 49,131 10,324 9,399 68,854 Income tax expense 16,790 3,692 1,891 22,373 Net income $32,341 $6,632 $7,508 $46,481 Total assets at period end $3,354,633 $64,625 $961,857 $4,381,115 Expenditures for long-lived assets 2,267 464 381 3,112

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) The following tables present the activity in other comprehensive income (loss): (Dollars in thousands) Year ended December 31, 2018 Pre-tax Amounts Income Taxes Net of Tax Securities available for sale: Changes in fair value of securities available for sale ($12,063 ) ($2,835 ) ($9,228 ) Net (gains) losses on securities reclassified into earnings — — — Net change in fair value of securities available for sale (12,063 ) (2,835 ) (9,228 ) Cash flow hedges: Changes in fair value of cash flow hedges 639 151 488 Net cash flow hedge losses reclassified into earnings (1) 170 39 131 Net change in the fair value of cash flow hedges 809 190 619 Defined benefit pension plan obligations: Defined benefit pension plan obligation adjustment 3,098 729 2,369 Amortization of net actuarial losses (2) 1,907 448 1,459 Amortization of net prior service credits (2) (24 ) (6 ) (18 ) Net change in defined benefit pension plan obligations 4,981 1,171 3,810 Total other comprehensive income ($6,273 ) ($1,474 ) ($4,799 ) (1) The pre-tax amounts are included in interest expense on FHLB advances, interest expense on junior subordinated debentures and interest and fees on loans in the Consolidated Statements of Income. (2) The pre-tax amounts are included in other expenses in the Consolidated Statements of Income. (Dollars in thousands) Year ended December 31, 2017 Pre-tax Amounts Income Taxes Net of Tax Securities available for sale: Changes in fair value of securities available for sale $986 $365 $621 Net (gains) losses on securities reclassified into earnings — — — Net change in fair value of securities available for sale 986 365 621 Cash flow hedges: Changes in fair value of cash flow hedges (774 ) (223 ) (551 ) Net cash flow hedge losses reclassified into earnings (1) 792 293 499 Net change in the fair value of cash flow hedges 18 70 (52 ) Defined benefit pension plan obligations: Defined benefit pension plan obligation adjustment (1,591 ) (594 ) (997 ) Amortization of net actuarial losses (2) 1,461 546 915 Amortization of net prior service credits (2) (24 ) (9 ) (15 ) Net change in defined benefit pension plan obligations (154 ) (57 ) (97 ) Total other comprehensive income $850 $378 $472 (1) The pre-tax amounts are included in interest expense on FHLB advances, interest expense on junior subordinated debentures and interest and fees on loans in the Consolidated Statements of Income. (2) The pre-tax amounts are included in other expenses in the Consolidated Statements of Income. (Dollars in thousands) Year ended December 31, 2016 Pre-tax Amounts Income Taxes Net of Tax Securities available for sale: Changes in fair value of securities available for sale ($12,502 ) ($4,626 ) ($7,876 ) Net (gains) losses on securities reclassified into earnings — — — Net change in fair value of securities available for sale (12,502 ) (4,626 ) (7,876 ) Cash flow hedges: Changes in fair value of cash flow hedges (403 ) (146 ) (257 ) Net cash flow hedge losses reclassified into earnings — — — Net change in the fair value of cash flow hedges (403 ) (146 ) (257 ) Defined benefit pension plan obligations: Defined benefit pension plan obligation adjustment (4,106 ) (1,518 ) (2,588 ) Amortization of net actuarial losses (1) 1,075 397 678 Amortization of net prior service credits (1) (24 ) (9 ) (15 ) Net change in defined benefit pension plan obligations (3,055 ) (1,130 ) (1,925 ) Total other comprehensive loss ($15,960 ) ($5,902 ) ($10,058 ) (1) The pre-tax amounts are included in other expense in the Consolidated Statements of Income. The following tables present the changes in accumulated other comprehensive income (loss) by component, net of tax: (Dollars in thousands) Net Unrealized Losses on Available For Sale Securities Net Unrealized (Losses) Gains on Cash Flow Hedges Defined Benefit Pension Plan Adjustment Total Balance at December 31, 2017 ($7,534 ) ($428 ) ($15,548 ) ($23,510 ) Other comprehensive (loss) income before reclassifications (9,228 ) 488 2,369 (6,371 ) Amounts reclassified from accumulated other comprehensive income — 131 1,441 1,572 Net other comprehensive (loss) income (9,228 ) 619 3,810 (4,799 ) Balance at December 31, 2018 ($16,762 ) $191 ($11,738 ) ($28,309 ) (Dollars in thousands) Net Unrealized (Losses) Gains on Available For Sale Securities Net Unrealized Losses on Cash Flow Hedges Defined Benefit Pension Plan Adjustment Total Balance at December 31, 2016 ($6,825 ) ($300 ) ($12,632 ) ($19,757 ) Other comprehensive income (loss) before reclassifications 621 (551 ) (741 ) (671 ) Amounts reclassified from accumulated other comprehensive income — 499 644 1,143 Net other comprehensive income (loss) 621 (52 ) (97 ) 472 Reclassification of income tax effects due to the adoption of ASU 2018-02 (1,330 ) (76 ) (2,819 ) (4,225 ) Balance at December 31, 2017 ($7,534 ) ($428 ) ($15,548 ) ($23,510 ) (Dollars in thousands) Net Unrealized Gains (Losses) on Available For Sale Securities Net Unrealized Losses on Cash Flow Hedges Defined Benefit Pension Plan Adjustment Total Balance at December 31, 2015 $1,051 ($43 ) ($10,707 ) ($9,699 ) Other comprehensive loss before reclassifications (7,876 ) (257 ) (2,588 ) (10,721 ) Amounts reclassified from accumulated other comprehensive income — — 663 663 Net other comprehensive loss (7,876 ) (257 ) (1,925 ) (10,058 ) Balance at December 31, 2016 ($6,825 ) ($300 ) ($12,632 ) ($19,757 )

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings per Common Share The following table presents the calculation of earnings per common share: (Dollars and shares in thousands, except per share amounts) Years ended December 31, 2018 2017 2016 Earnings per common share - basic: Net income $68,432 $45,925 $46,481 Less dividends and undistributed earnings allocated to participating securities (144 ) (108 ) (97 ) Net income available to common shareholders $68,288 $45,817 $46,384 Weighted average common shares 17,272 17,207 17,081 Earnings per common share - basic $3.95 $2.66 $2.72 Earnings per common share - diluted: Net income $68,432 $45,925 $46,481 Less dividends and undistributed earnings allocated to participating securities (144 ) (108 ) (97 ) Net income available to common shareholders $68,288 $45,817 $46,384 Weighted average common shares 17,272 17,207 17,081 Dilutive effect of common stock equivalents 119 131 127 Weighted average diluted common shares 17,391 17,338 17,208 Earnings per common share - diluted $3.93 $2.64 $2.70 Weighted average common stock equivalents, not included in common stock equivalents above because they were anti-dilutive, totaled 55,821 , 11,572 and 59,158 for the years ended December 31, 2018 , 2017 and 2016 , respectively.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Financial Instruments with Off-Balance Risk The Corporation is a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers and to manage the Corporation’s exposure to fluctuations in interest rates. These financial instruments include commitments to extend credit, standby letters of credit, forward loan commitments, loan related derivative contracts and interest rate risk management contracts. These instruments involve, to varying degrees, elements of credit risk in excess of the amount recognized in the Corporation’s Consolidated Balance Sheets. The contract or notional amounts of these instruments reflect the extent of involvement the Corporation has in particular classes of financial instruments. The Corporation’s credit policies with respect to interest rate swap agreements with commercial borrowers, commitments to extend credit and financial guarantees are similar to those used for loans. The interest rate swaps with other counterparties are generally subject to bilateral collateralization terms. The following table presents the contractual and notional amounts of financial instruments with off-balance sheet risk: (Dollars in thousands) December 31, 2018 2017 Financial instruments whose contract amounts represent credit risk: Commitments to extend credit: Commercial loans $533,884 $537,310 Home equity lines 270,462 254,855 Other loans 46,698 48,819 Standby letters of credit 7,706 6,666 Financial instruments whose notional amounts exceed the amount of credit risk: Forward loan commitments: Interest rate lock commitments 30,766 45,139 Forward sale commitments 61,993 71,539 Loan related derivative contracts: Interest rate swaps with customers 648,050 545,049 Mirror swaps with counterparties 648,050 545,049 Risk participation-in agreements 46,510 34,052 Foreign exchange contracts 2,784 3,005 Interest rate risk management contracts: Interest rate swaps 60,000 60,000 See Note 13 for additional disclosure pertaining to derivative financial instruments. Commitments to Extend Credit Commitments to extend credit are agreements to lend to a customer as long as there are no violations of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since some of the commitments are expected to expire without being drawn upon, total commitment amounts do not necessarily represent future cash requirements. Each borrower’s creditworthiness is evaluated on a case-by-case basis. The amount of collateral obtained is based on management’s credit evaluation of the borrower. Standby Letters of Credit Standby letters of credit are conditional commitments issued to guarantee the performance of a customer to a third party. These standby letters of credit are primarily issued to support the financing needs of the Bank’s commercial customers. The credit risk involved in issuing standby letters of credit is essentially the same as that involved in extending loan facilities to customers. The collateral supporting those commitments is essentially the same as for other commitments. Most standby letters of credit extend for one year. The maximum potential amount of undiscounted future payments, not reduced by amounts that may be recovered totaled $7.7 million and $6.7 million , as of December 31, 2018 and 2017 , respectively. At December 31, 2018 and 2017 , there were no liabilities to beneficiaries resulting from standby letters of credit. Fee income on standby letters of credit was insignificant for the years ended December 31, 2018 , 2017 and 2016 . At December 31, 2018 and 2017 , a substantial portion of the standby letters of credit were supported by pledged collateral. The collateral obtained is determined based on management’s credit evaluation of the customer. Should the Corporation be required to make payments to the beneficiary, repayment from the customer to the Corporation is required. Forward Loan Commitments Interest rate lock commitments are extended to borrowers and relate to the origination of mortgage loans held for sale. To mitigate the interest rate risk and pricing risk associated with these rate locks and mortgage loans held for sale, the Corporation enters into forward sale commitments. Both interest rate lock commitments and forward sale commitments are derivative financial instruments. Leases At December 31, 2018 , the Corporation was committed to rent premises used in business operations under non-cancelable operating leases. Rental expense under the operating leases amounted to $4.3 million , $4.3 million and $4.0 million for December 31, 2018 , 2017 and 2016 , respectively. The following table presents the minimum annual lease payments under the terms of these leases, exclusive of renewal provisions: (Dollars in thousands) Years ending December 31: 2019 $3,544 2020 2,980 2021 2,677 2022 2,293 2023 2,059 2024 and thereafter 22,648 Total minimum lease payments $36,201 Lease expiration dates range from 5 months to 22 years, with additional renewal options on certain leases ranging from 1 to 5 years. Other Contingencies Litigation The Corporation is involved in various claims and legal proceedings arising out of the ordinary course of business. Management is of the opinion, based on its review with counsel of the development of such matters to date, that the ultimate disposition of such matters will not materially affect the consolidated financial position or results of operations of the Corporation. Other When selling a residential real estate mortgage loan or acting as originating agent on behalf of a third party, Washington Trust generally makes various representations and warranties. The specific representations and warranties depend on the nature of the transaction and the requirements of the buyer. Contractual liability may arise when the representations and warranties are breached. In the event of a breach of these representations and warranties, Washington Trust may be required to either repurchase the residential real estate mortgage loan (generally at unpaid principal balance plus accrued interest) with the identified defects or indemnify (“make-whole”) the investor for its losses. In the case of a repurchase, the Corporation will bear any subsequent credit loss on the residential real estate mortgage loan. Washington Trust has experienced an insignificant number of repurchase demands over a period of many years. As of December 31, 2018 and 2017 , the carrying value of loans repurchased due to representation and warranty claims was $1.2 million and $1.3 million , respectively. Washington Trust has recorded a reserve for its exposure to losses for premium recapture and the obligation to repurchase previously sold residential real estate mortgage loans. The reserve balance amounted to $140 thousand and $180 thousand at December 31, 2018 and 2017 , respectively, and is included in other liabilities in the Consolidated Balance Sheets. Any change in the estimate is recorded in mortgage banking revenues in the Consolidated Statements of Income.

Parent Company Financial Statem

Parent Company Financial Statements	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Parent Company Financial Statements	Parent Company Financial Statements The following tables present parent company only financial statements of the Bancorp, reflecting the investment in the Bank on the equity basis of accounting. The Statements of Changes in Shareholders’ Equity for the parent company only are identical to the Consolidated Statements of Changes in Shareholders’ Equity and are therefore not presented. Balance Sheets (Dollars in thousands, except par value) December 31, 2018 2017 Assets: Cash on deposit with bank subsidiary $1,912 $1,664 Investment in subsidiaries at equity value: Bank 467,657 433,010 Non-bank 1,869 1,821 Dividends receivable from bank subsidiary 7,762 7,770 Other assets 190 259 Total assets $479,390 $444,524 Liabilities: Junior subordinated debentures $22,681 $22,681 Dividends payable 8,439 7,087 Contingent consideration liability — 1,404 Other liabilities 86 68 Total liabilities 31,206 31,240 Shareholders’ Equity: Common stock of $.0625 par value; authorized 60,000,000 shares; issued and outstanding 17,302,037 shares in 2018 and 17,226,508 shares in 2017 1,081 1,077 Paid-in capital 119,888 117,961 Retained earnings 355,524 317,756 Accumulated other comprehensive loss (28,309 ) (23,510 ) Total shareholders’ equity 448,184 413,284 Total liabilities and shareholders’ equity $479,390 $444,524 Statements of Income (Dollars in thousands) Years ended December 31, 2018 2017 2016 Income: Dividends from subsidiaries: Bank $32,394 $27,900 $24,442 Non-bank 24 18 114 Other income — — 1 Total income 32,418 27,918 24,557 Expenses: Interest on junior subordinated debentures 869 613 491 Legal and professional fees 187 169 98 Change in fair value of contingent consideration (187 ) (643 ) (898 ) Other 324 298 282 Total expenses 1,193 437 (27 ) Income before income taxes 31,225 27,481 24,584 Income tax benefit (expense) 284 340 (15 ) Income before equity in undistributed earnings (losses) of subsidiaries 31,509 27,821 24,569 Equity in undistributed earnings (losses) of subsidiaries: Bank 36,876 18,193 22,008 Non-bank 47 (89 ) (96 ) Net income $68,432 $45,925 $46,481 Statements of Cash Flows (Dollars in thousands) Years ended December 31, 2018 2017 2016 Cash flow from operating activities: Net income $68,432 $45,925 $46,481 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed (earnings) losses of subsidiaries: Bank (36,876 ) (18,193 ) (22,008 ) Non-bank (47 ) 89 96 Decrease (increase) in dividend receivable 8 (1,252 ) (1,436 ) Decrease in other assets 70 72 45 Increase (decrease) in accrued expenses and other liabilities 17 22 (12 ) Change in fair value of contingent consideration liability (187 ) (643 ) (898 ) Tax benefit from stock option exercises and other equity awards 496 508 1,016 Other, net (465 ) (673 ) (1,051 ) Net cash provided by operating activities 31,448 25,855 22,233 Cash flows from financing activities: Payment of contingent consideration (1,217 ) — — Proceeds from stock option exercises and issuance of other equity awards, net of awards surrendered (671 ) 366 978 Cash dividends paid (29,312 ) (26,300 ) (24,637 ) Net cash used in financing activities (31,200 ) (25,934 ) (23,659 ) Net increase (decrease) in cash 248 (79 ) (1,426 ) Cash at beginning of year 1,664 1,743 3,169 Cash at end of year $1,912 $1,664 $1,743

Selected Quarterly Consolidated

Selected Quarterly Consolidated Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Consolidated Financial Data (Unaudited)	Selected Quarterly Consolidated Financial Data (Unaudited) (Dollars and shares in thousands, except per share amounts) 2018 First Quarter Second Quarter Third Quarter Fourth Quarter Interest and dividend income $40,440 $43,286 $45,164 $47,517 Interest expense 8,588 10,175 11,715 13,639 Net interest income 31,852 33,111 33,449 33,878 Provision for loan losses — 400 350 800 Net interest income after provision for loan losses 31,852 32,711 33,099 33,078 Noninterest income 15,743 15,993 15,215 15,163 Noninterest expense 27,130 26,288 26,062 26,682 Income before income taxes 20,465 22,416 22,252 21,559 Income tax expense 4,254 4,742 4,741 4,523 Net income $16,211 $17,674 $17,511 $17,036 Net income available to common shareholders $16,173 $17,636 $17,475 $17,004 Weighted average common shares outstanding - basic 17,234 17,272 17,283 17,297 Weighted average common shares outstanding - diluted 17,345 17,387 17,382 17,385 Per share information: Basic earnings per common share $0.94 $1.02 $1.01 $0.98 Diluted earnings per common share $0.93 $1.01 $1.01 $0.98 Cash dividends declared per share $0.43 $0.43 $0.43 $0.47 (Dollars and shares in thousands, except per share amounts) 2017 First Quarter Second Quarter Third Quarter Fourth Quarter Interest and dividend income $35,664 $37,153 $37,869 $38,900 Interest expense 6,985 7,249 7,810 8,011 Net interest income 28,679 29,904 30,059 30,889 Provision for loan losses 400 700 1,300 200 Net interest income after provision for loan losses 28,279 29,204 28,759 30,689 Noninterest income 14,510 16,806 17,283 16,210 Noninterest expense 25,286 26,306 26,754 25,754 Income before income taxes 17,503 19,704 19,288 21,145 Income tax expense 5,721 6,505 6,326 13,163 Net income $11,782 $13,199 $12,962 $7,982 Net income available to common shareholders $11,755 $13,170 $12,934 $7,958 Weighted average common shares outstanding - basic 17,186 17,206 17,212 17,223 Weighted average common shares outstanding - diluted 17,293 17,316 17,318 17,349 Per share information: Basic earnings per common share $0.68 $0.77 $0.75 $0.46 Diluted earnings per common share $0.68 $0.76 $0.75 $0.46 Cash dividends declared per share $0.38 $0.38 $0.39 $0.39

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Consolidation	Washington Trust Bancorp, Inc. (the “Bancorp”) is a publicly-owned registered bank holding company that has elected to be a financial holding company. The Bancorp’s subsidiaries include The Washington Trust Company, of Westerly (the “Bank”), a Rhode Island chartered commercial bank founded in 1800, and Weston Securities Corporation (“WSC”). Through its subsidiaries, the Bancorp offers a complete product line of financial services including commercial, residential and consumer lending, retail and commercial deposit products, and wealth management services through its offices in Rhode Island, eastern Massachusetts and Connecticut. The consolidated financial statements include the accounts of the Bancorp and its subsidiaries (collectively, the “Corporation” or “Washington Trust”). All intercompany balances and transactions have been eliminated in consolidation.
Basis of Accounting	Certain previously reported amounts have been reclassified to conform to current year’s presentation. The Bancorp also owns the common stock of two capital trusts, which have issued trust preferred securities. These capital trusts are variable interest entities in which the Bancorp is not the primary beneficiary and, therefore, are not consolidated. The capital trust’s only assets are junior subordinated debentures issued by the Bancorp, which were acquired by the capital trusts using the proceeds from the issuance of the trust preferred securities and common stock. The Bancorp’s equity interest in the capital trusts, classified in other assets, and the junior subordinated debentures are included in the Consolidated Balance Sheets. Interest expense on the junior subordinated debentures is included in the Consolidated Statements of Income. The accounting and reporting policies of the Corporation conform to accounting principles generally accepted in the United States of America (“GAAP”) and to general practices of the banking industry.
Use of Estimates	In preparing the financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheet and revenues and expenses for the period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to change are the determination of the allowance for loan losses, the valuation of goodwill and identifiable intangible assets, the assessment of investment securities for impairment and the accounting for defined benefit pension plans.
Cash and Cash Equivalents	Cash Flows For purposes of reporting cash flows, cash and cash equivalents include cash on hand, amounts due from banks, and other short-term investments. Short-term Investments Short-term investments consist of highly liquid investments with a maturity date of three months or less when purchased and are considered to be cash equivalents. The Corporation’s short-term investments may be comprised of overnight federal funds sold, securities purchased under resale agreements, money market mutual funds and U.S. Treasury bills.
Securities	Securities Management determines the appropriate classification of securities at the time of purchase. Investments in debt securities that management has the positive intent and ability to hold to maturity are classified as held to maturity and carried at amortized cost. Investments not classified as held to maturity are classified as available for sale. Securities available for sale consist of debt securities that are available for sale to respond to changes in market interest rates, liquidity needs, changes in funding sources and other similar factors. These assets are specifically identified and are carried at fair value. Changes in fair value of available for sale securities, net of applicable income taxes, are reported as a separate component of shareholders’ equity. Washington Trust does not have a trading portfolio. Premiums and discounts are amortized and accreted over the term of the securities on a method that approximates the level yield method. The amortization and accretion is included in interest income on securities. Interest income is recognized when earned. Realized gains or losses from sales of securities are recorded on the trade date and are determined using the specific identification method. The fair values of securities may be based on either quoted market prices or third party pricing services. When the fair value of an investment security is less than its amortized cost basis, the Corporation assesses whether the decline in value is other-than-temporary. The Corporation considers whether evidence indicating the cost of the investment is recoverable outweighs evidence to the contrary. Evidence considered in this assessment includes the reasons for impairment, the severity and duration of the impairment, changes in the value subsequent to the reporting date, forecasted performance of the issuer, changes in the dividend or interest payment practices of the issuer, changes in the credit rating of the issuer or the specific security, and the general market condition in the geographic area or industry in which the issuer operates. In determining whether an other-than-temporary impairment has occurred for debt securities, the Corporation compares the present value of cash flows expected to be collected from the security with the amortized cost of the security. If the present value of expected cash flows is less than the amortized cost of the security, then the entire amortized cost of the security will not be recovered; that is, a credit loss exists, and an other-than-temporary impairment shall be considered to have occurred. The credit loss component of an other-than-temporary impairment write-down for debt securities is recorded in earnings while the remaining portion of the impairment loss is recognized, net of tax, in other comprehensive income provided that the Corporation does not intend to sell the underlying debt security and it is more-likely-than-not that the Corporation would not have to sell the debt security prior to recovery of the unrealized loss, which may be to maturity. If the Corporation intended to sell any securities with an unrealized loss or it is more-likely-than-not that the Corporation would be required to sell the investment securities before recovery of their amortized cost basis, then the entire unrealized loss would be recorded in earnings.
Federal Home Loan Bank Stock	Federal Home Loan Bank Stock The Bank is a member of the FHLB. The FHLB is a cooperative that provides services, including funding in the form of advances, to its member banking institutions. As a requirement of membership, the Bank must own a minimum amount of FHLB stock, calculated periodically based primarily on its level of borrowings from the FHLB. No market exists for shares of FHLB stock and therefore, it is carried at cost. FHLB stock may be redeemed at par value five years following termination of FHLB membership, subject to limitations which may be imposed by the FHLB or its regulator, the Federal Housing Finance Board, to maintain capital adequacy of the FHLB. While the Bank currently has no intentions to terminate its FHLB membership, the ability to redeem its investment in FHLB stock would be subject to the conditions imposed by the FHLB. The Bank monitors its investment to determine if impairment exists. Based on the capital adequacy and the liquidity position of the FHLB, management believes there is no impairment related to the carrying amount of FHLB stock included in the Consolidated Balance Sheet as of December 31, 2018 .
Mortgage Loans Held for Sale	Mortgage Loans Held for Sale Residential mortgage loans originated and intended for sale in the secondary market are classified as held for sale. Accounting Standards Codification (“ASC”) 825, “Financial Instruments” allows for the irrevocable option to elect fair value accounting for the initial and subsequent measurement for certain financial assets and liabilities on a contract-by-contract basis that may otherwise not be required to be measured at fair value under other accounting standards. The Corporation has elected the fair value option for mortgage loans held for sale in order to better match changes in fair values of the loans with changes in the fair value of the derivative forward sale commitment contracts used to economically hedge them. Changes in the fair value of mortgage loans held for sale accounted for under the fair value option are recorded in earnings and are partially offset by changes in fair value of forward sale commitments. These changes in fair value are included in mortgage banking revenues. Gains and losses on residential loan sales are recognized at the time of sale and included in mortgage banking revenues. Upfront fees and costs related to mortgage loans held for sale for which the fair value option was elected are recognized in mortgage banking revenues as received / incurred and are not deferred. Commissions received on mortgage loans brokered to various investors are recognized when received and included in mortgage banking revenues.
Loan Servicing Rights	Loan Servicing Rights When mortgage loans held for sale are sold with servicing retained, mortgage servicing right assets are recognized as separate assets. Mortgage servicing rights are originally recorded at fair value. Fair value is based on a valuation model that incorporates assumptions that market participants would use in estimating future net servicing income, such as the cost to service, the discount rate, ancillary income, prepayment speeds, and default rates and losses. Mortgage servicing rights are included in other assets. Mortgage servicing rights are amortized as an offset to mortgage banking revenues over the period of estimated net servicing income. They are periodically evaluated for impairment based on their fair value. Impairment is measured on an aggregated basis by stratifying the rights based on homogeneous characteristics such as note rate and loan type. The fair value is estimated based on the present value of expected cash flows, incorporating assumptions for discount rate, prepayment speed and servicing cost. Any impairment is recognized through a valuation allowance and as a reduction to mortgage banking revenues.
Loans	Loans Portfolio Loans Loans are carried at the principal amount outstanding, adjusted by partial charge-offs and net of unamortized deferred loan origination fees and costs. Interest income is accrued on a level yield basis based upon principal amounts outstanding, except for loans on nonaccrual status. Deferred loan origination fees and costs are amortized as an adjustment to yield over the term of the related loans. For purchased loans, which did not show signs of credit deterioration at the time of purchase, interest income is also accrued on a level yield basis based upon principal amounts outstanding and is then further adjusted by accretion of any discount or amortization of any premium associated with the loans. Nonaccrual Loans Loans, with the exception of certain well-secured loans that are in the process of collection, are placed on nonaccrual status and interest recognition is suspended when such loans are 90 days or more overdue with respect to principal and/or interest, or sooner if considered appropriate by management. Well-secured loans are permitted to remain on accrual status provided that full collection of principal and interest is assured and the loan is in the process of collection. Loans are also placed on nonaccrual status when, in the opinion of management, full collection of principal and interest is doubtful. When loans are placed on nonaccrual status, interest previously accrued but not collected is reversed against current period income. Subsequent interest payments received on nonaccrual loans are applied to the outstanding principal balance of the loan or recognized as interest income depending on management’s assessment of the ultimate collectability of the loan. Loans are removed from nonaccrual status when they have been current as to principal and interest for a period of time, the borrower has demonstrated an ability to comply with repayment terms, and when, in management’s opinion, the loans are considered to be fully collectible. Troubled Debt Restructured Loans Loans are considered to be troubled debt restructurings when the Corporation has granted concessions to a borrower due to the borrower’s financial condition that it otherwise would not have considered. These concessions may include modifications of the terms of the debt such as deferral of payments, extension of maturity, reduction of principal balance, reduction of the stated interest rate other than normal market rate adjustments, or a combination of these concessions. Debt may be bifurcated with separate terms for each tranche of the restructured debt. Restructuring of a loan in lieu of aggressively enforcing the collection of the loan may benefit the Corporation by increasing the ultimate probability of collection. Restructured loans are classified as accruing or non-accruing based on management’s assessment of the collectability of the loan. Loans which are already on nonaccrual status at the time of the restructuring generally remain on nonaccrual status for approximately six months before management considers such loans for return to accruing status. Accruing restructured loans are placed into nonaccrual status if and when the borrower fails to comply with the restructured terms and management deems it unlikely that the borrower will return to a status of compliance in the near term. Troubled debt restructurings are reported as such for at least one year from the date of the restructuring. In years after the restructuring, troubled debt restructured loans are removed from this classification if the restructuring did not involve a below-market rate concession and the loan is not deemed to be impaired based on the terms specified in the restructuring agreement. Impaired Loans Impaired loans are evaluated on an individual basis and include nonaccrual loans and loans restructured in a troubled debt restructuring. Impairment is measured using a discounted cash flow method based upon the loan’s contractual effective interest rate, or at the loan’s observable market price, or if the loan is collateral dependent, at fair value. For collateral dependent loans for which repayment is dependent on the sale of the collateral, management adjusts the fair value for estimated costs to sell. For collateral dependent loans for which repayment is dependent on the operation of the collateral, such as accruing troubled debt restructured loans, estimated costs to sell are not incorporated into the measurement.
Allowance for Loan Losses	Allowance for Loan Losses The allowance for loan losses is management’s best estimate of the risk of loss inherent in the loan portfolio as of the balance sheet date. The allowance is increased by provisions charged to earnings and by recoveries of amounts previously charged-off, and is reduced by charge-offs on loans. Loan charge-offs are recognized when management believes the collectability of the principal balance outstanding is unlikely. Full or partial charge-offs on collateral dependent impaired loans are generally recognized when the collateral is deemed to be insufficient to support the carrying value of the loan. The level of the allowance is based on management’s ongoing review of the growth and composition of the loan portfolio, historical loss experience, estimated loss emergence period (the period from the event that triggers the eventual default until the actual loss is recognized with a charge-off), current economic conditions, analysis of asset quality and credit quality levels and trends, the performance of individual loans in relation to contract terms and other pertinent factors. A methodology is used to systematically measure the amount of estimated loan loss exposure inherent in the loan portfolio for the purposes of establishing a sufficient allowance for loan losses. The methodology includes: (1) the identification of loss allocations for individual loans deemed to be impaired and (2) the application of loss allocation factors for non-impaired loans based on historical loss experience and estimated loss emergence period, with adjustments for various exposures that management believes are not adequately represented by historical loss experience. A loan is considered impaired when, based on current information and events, it is probable that the Corporation will not be able to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Loss allocations for loans deemed to be impaired are measured using a discounted cash flow method based upon the loan’s contractual effective interest rate, or at the loan’s observable market price, or, if the loan is collateral dependent, at the fair value of the collateral. For collateral dependent loans for which repayment is dependent on the sale of the collateral, management adjusts the fair value for estimated costs to sell. For collateral dependent loans for which repayment is dependent on the operation of the collateral, such as accruing troubled debt restructured loans, estimated costs to sell are not incorporated into the measurement. Management may also adjust appraised values to reflect estimated market value declines or apply other discounts to appraised values for unobservable factors resulting from its knowledge of circumstances associated with the property. For loans that are collectively evaluated, loss allocation factors are derived by analyzing historical loss experience by loan segment over an established look-back period deemed to be relevant to the inherent risk of loss in the portfolios. Loans are segmented by loan type, collateral type, delinquency status and loan risk rating, where applicable. These loss allocation factors are adjusted to reflect the loss emergence period. These amounts are supplemented by certain qualitative risk factors reflecting management’s view of how losses may vary from those represented by historical loss rates. These qualitative risk factors include: 1) changes in lending policies and procedures, including changes in underwriting standards and collection, charge-off, and recovery practices not considered elsewhere in estimating credit losses; 2) changes in international, national, regional, and local economic and business conditions and developments that affect the collectability of the portfolio, including the condition of various market segments; 3) changes in the nature and volume of the portfolio and in the terms of loans; 4) changes in the experience, ability, and depth of lending management and other relevant staff; 5) changes in the volume and severity of past due loans, the volume of nonaccrual loans, and the volume and severity of adversely classified or rated loans; 6) changes in the quality of the institution’s loan review system; 7) changes in the value of underlying collateral for collateral dependent loans; 8) the existence and effect of any concentrations of credit, and changes in the level of such concentrations; and 9) the effect of other external factors such as legal and regulatory requirements on the level of estimated credit losses in the institution’s existing portfolio. Because the methodology is based upon historical experience and trends, current economic data, as well as management’s judgment, factors may arise that result in different estimations. Adversely different conditions or assumptions could lead to increases in the allowance. In addition, various regulatory agencies periodically review the allowance for loan losses. Such agencies may require additions to the allowance based on their judgments about information available to them at the time of their examination. The allowance is an estimate, and ultimate losses may vary from management’s estimate. Changes in the estimate are recorded in the results of operations in the period in which they become known, along with provisions for estimated losses incurred during that period.
Premises and Equipment	Premises and Equipment Land is carried at cost. Premises and equipment are carried at cost less accumulated depreciation. Depreciation for financial reporting purposes is calculated on the straight-line method over the estimated useful lives of assets. Leasehold improvements are depreciated over the shorter of the lease terms or the estimated useful lives of the improvements. Expected terms include lease renewal options to the extent that the exercise of such renewals is reasonably assured. Expenditures for major additions and improvements are capitalized while the costs of current maintenance and repairs are charged to operating expenses. The estimated useful lives of premises and improvements range from 5 to 40 years. For furniture, fixtures and equipment, the estimated useful lives range from 3 to 20 years.
Goodwill and Identifiable Intangible Assets	Goodwill and Identifiable Intangible Assets Goodwill represents the excess of the purchase price over the net fair value of the acquired businesses. Goodwill is not amortized but is tested for impairment at the reporting unit level, defined as the segment level, at least annually in the fourth quarter or more frequently whenever events or circumstances occur that indicate that it is more-likely-than-not that an impairment loss has occurred. In assessing impairment, the Corporation has the option to perform a qualitative analysis 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 the reporting unit is less than its carrying amount. If, after assessing the totality of such events or circumstances, we determine it is not more-likely-than-not that the fair value of a reporting unit is less than its carrying amount, then we would not be required to perform an impairment test. The quantitative impairment analysis requires a comparison of each reporting unit’s fair value to its carrying value to identify potential impairment. Goodwill impairment exists when a reporting unit’s carrying value of goodwill exceeds its implied fair value. Significant judgment is applied when goodwill is assessed for impairment. This judgment includes, but may not be limited to, the selection of appropriate discount rates, the identification of relevant market comparables and the development of cash flow projections. The selection and weighting of the various fair value techniques may result in a higher or lower fair value. Judgment is applied in determining the weightings that are most representative of fair value. Intangible assets identified in acquisitions consist of advisory contracts. The value attributed to intangible assets was based on the time period over which they are expected to generate economic benefits. Intangible assets are amortized over their estimated lives using a method that approximates the amount of economic benefits that are realized by the Corporation. Intangible assets with definite lives are tested for impairment whenever events or circumstances occur that indicate that the carrying amount may not be recoverable. If applicable, the Corporation tests each of the intangibles by comparing the carrying value of the intangible asset to the sum of undiscounted cash flows expected to be generated by the asset. If the carrying amount of the asset exceeds its undiscounted cash flows, then an impairment loss would be recognized for the amount by which the carrying amount exceeds its fair value. Impairment would result in a write-down to the estimated fair value based on the anticipated discounted future cash flows. The remaining useful life of the intangible assets that are being amortized is also evaluated to determine whether events and circumstances warrant a revision to the remaining period of amortization.
Impairment of Long-Lived Assets Other than Goodwill	Impairment of Long - Lived Assets Other than Goodwill Long-lived assets, including premises and equipment, are reviewed for impairment whenever events or changes in business circumstances indicate that the the carrying amount may not be fully recoverable. If impairment is determined to exist, any related impairment loss is calculated based on fair value. Impairment losses on assets to be disposed of, if any, are based on the estimated proceeds to be received, less costs of disposal.
Property Acquired through Foreclosure or Repossession	Property Acquired through Foreclosure or Repossession Property acquired through foreclosure or repossession is carried at the lower of cost or fair value less estimated costs to sell. Fair value of such assets is determined based on independent appraisals and other relevant factors. Any write-down to fair value at the time of foreclosure or repossession is charged to the allowance for loan losses. Subsequent to foreclosure or repossession, a valuation allowance is maintained for declines in market value and for estimated selling expenses. Upon sale of foreclosed property, any excess of the carrying value over the sales proceeds is recognized as a loss on sale. Any excess of sales proceeds over the carrying value of the foreclosed property is first applied as a recovery to the valuation allowance, if any, with the remainder being recognized as a gain on sale. Changes to the valuation allowance, expenses associated with ownership of these properties, and gains and losses from their sale are included in foreclosed property costs. Loans that are substantively repossessed include only those loans for which the Corporation has obtained control of the collateral, but has not completed legal foreclosure proceedings.
Bank-Owned Life Insurance	Bank-Owned Life Insurance The investment in BOLI represents the cash surrender value of life insurance policies on the lives of certain employees who have provided positive consent allowing the Bank to be the beneficiary of such policies. Increases in the cash value of the policies, as well as insurance proceeds received, are recorded in noninterest income and are not subject to income taxes. The financial strength of the insurance carrier is reviewed prior to the purchase of BOLI and annually thereafter.
Investment in Real Estate Limited Partnership	Investment in Real Estate Limited Partnerships The Bank has a 99.9% ownership interest in two real estate limited partnerships that renovate, own and operate two low-income housing complexes. The Bank neither actively participates nor has a controlling interest in these limited partnerships and accounts for its investments under the equity method of accounting. The carrying value of the investments is recorded in other assets on the Consolidated Balance Sheet. Net losses generated by the partnership are recorded as a reduction to the Bank’s investment and as a reduction of other noninterest income in the Consolidated Statements of Income. Tax credits generated by the partnership are recorded as a reduction in the income tax provision in the year they are allowed for tax reporting purposes. The results of operations of the real estate limited partnerships are periodically reviewed to determine if the partnership generates sufficient operating cash flow to fund its current obligations. In addition, the current value of the underlying properties is compared to the outstanding debt obligations. If it is determined that the investment is permanently impaired, the carrying value will be written down to the estimated realizable value.
Transfers and Servicing of Assets and Extinguishments of Liabilities	Transfers and Servicing of Assets and Extinguishments of Liabilities The accounting for transfers and servicing of financial assets and extinguishments of liabilities is based on consistent application of a financial components approach that focuses on control. This approach distinguishes transfers of financial assets that are sales from transfers that are secured borrowings. After a transfer of financial assets, the Corporation recognizes all financial and servicing assets it controls and liabilities it has incurred and derecognizes financial assets it no longer controls and liabilities that have been extinguished. This financial components approach focuses on the assets and liabilities that exist after the transfer. Many of these assets and liabilities are components of financial assets that existed prior to the transfer. If a transfer does not meet the criteria for a sale, the transfer is accounted for as a secured borrowing with a pledge of collateral.
Wealth Management Assets Under Administration	Wealth Management Assets Under Administration Assets under administration represent assets held in a fiduciary or agency capacity for wealth management clients and are not included in the Consolidated Balance Sheets, as these are not assets of the Corporation. Wealth management revenue derived from the administration, management and custody of assets under administration are referred to as asset-based revenues.
Revenue from Contracts with Customers	Revenue from Contracts with Customers Prior to January 1, 2018, fee revenue such as wealth management revenues and service charges on deposit accounts were recognized when earned or to the extent services were completed. Effective January 1, 2018, the Corporation adopted the provisions of Accounting Standards Update No. 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”), as amended. ASU 2014-09 provides a revenue recognition framework for contracts with customers unless those contracts are within the scope of other accounting standards. Revenue from contracts with customers is measured based on the consideration specified in the contract with a customer. The Corporation recognizes revenue from contracts with customers when it satisfies its performance obligations. The performance obligations are generally satisfied as services are rendered and can either be satisfied at a point in time or over time. The Corporation recognizes revenue that is transactional in nature and such revenue is earned at a point in time. Revenue that is recognized at a point in time includes card interchange fees (fee income related to debit card transactions), ATM fees, wire transfer fees, overdraft charge fees, and stop-payment and returned check fees. Such revenue is derived from transactional information and is recognized as revenue immediately as the transactions occur or upon providing the service to complete the customer’s transaction. The Corporation recognizes revenue over a period of time, generally monthly, as services are performed and performance obligations are satisfied. Such revenue includes wealth management revenues and service charges on deposit accounts. Wealth management revenues are categorized as either asset-based revenues or transaction-based revenues. Asset-based revenues include trust and investment management fees that are earned based upon a percentage of asset values under administration. Transaction-based revenues include financial planning fees, tax preparation fees, commissions and other service fees. Fee revenue from service charges on deposit accounts represent the service charges assessed to customer who hold deposit accounts at the Bank. In certain cases, other parties are involved with providing services to our customers. If the Corporation is a principal in the transaction (providing services itself or through a third party on its behalf), revenues are reported based on the gross consideration received from the customer and any related expenses are reported gross in noninterest expense. If the Corporation is an agent in the transaction (referring customers to another party to provide services), the Corporation reports its net fee or commission retained as revenue. For certain commissions and incentives, such as those paid to employees in our wealth management services and commercial banking segments in order to obtain customer contracts, contract cost assets are established. The contract cost assets are capitalized and amortized over the estimated useful life that the asset is expected to generate benefits. The amortization of the contract cost asset is recorded within salaries and employee benefits expense in the Consolidated Statements of Income.
Pension Costs	Pension Costs Pension benefits are accounted for using the net periodic benefit cost method, which recognizes the compensation cost of an employee’s pension benefit over that employee’s approximate service period. Pension benefit costs and benefit obligations incorporate various actuarial and other assumptions, including discount rates, mortality, rates of return on plan assets and compensation increases. Management evaluates these assumptions on an annual basis and makes modifications to the assumptions based on current rates and trends when it is appropriate to so do. The effect of modifications to those assumptions is recorded in other comprehensive income (loss) and amortized to net periodic cost over future periods. Management believes that the assumptions utilized in recording its obligations under its plans are reasonable based on its experience and market conditions. The service cost component of net periodic benefit cost is recognized within salaries and employee benefits expense in the Consolidated Statements of Income. All other components of net periodic benefit cost are recognized in other noninterest expense in the Consolidated Statements of Income. The funded status of defined benefit pension plans, measured as the difference between the fair value of plan assets and the projected benefit obligation, is recognized in the Consolidated Balance Sheet. The changes in the funded status of the defined benefit plans, including actuarial gains and losses and prior service costs and credits, are recognized in comprehensive income in the year in which the changes occur.
Share-Based Compensation	Share-Based Compensation Share-based compensation plans provide for awards of stock options and other equity incentives, including nonvested share units and nonvested performance share units. Compensation expense for awards is recognized over the service period based on the fair value at the date of grant. Grant date fair value for stock options is estimated using the Black-Scholes option-pricing model. Awards of nonvested share units and nonvested performance share units are valued at the fair market value of the Bancorp’s common stock as of the award date. Nonvested performance share unit compensation expense is based on the most recent performance assumption available and is adjusted as assumptions change. Forfeitures are recognized when they occur. Effective January 1, 2017, excess tax benefits (expenses) related to stock option exercises, settlement of other equity awards and dividends paid on nonvested share awards are recorded as a decrease (increase) to income tax expense. Prior to 2017, such excess tax benefits were recognized as additional paid in capital in shareholders' equity and did not impact income tax expense. Excess tax benefits (expenses) on the settlement of share-based awards are reflected in the Consolidated Statements of Cash Flows as an operating activity.
Income Taxes	Income Taxes Income tax expense is determined based on the asset and liability method, whereby deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Additionally, a liability for unrecognized tax benefits is recorded for uncertain tax positions taken by the Corporation on its tax returns for which there is less than a 50% likelihood of being recognized upon a tax examination. The Corporation records interest related to unrecognized tax benefits in income tax expense. Penalties, if incurred, would be recognized as a component of income tax expense.
Segment Reporting	Segment Reporting The Corporation segregates financial information in assessing its results among its Commercial Banking and Wealth Management Services operating segments. The amounts in the Corporate unit include activity not related to the segments. The methodologies and organizational hierarchies that define the business segments are periodically reviewed and revised. Results may be restated, when necessary, to reflect changes in organizational structure or allocation methodology. Any changes in estimates and allocations that may affect the reported results of any business segment will not affect the consolidated financial position or results of operations of the Corporation as a whole. Management uses certain methodologies to allocate income and expenses to the business lines. A funds transfer pricing (“FTP”) methodology is used to assign interest income and interest expense to each interest-earning asset and interest-bearing liability on a matched maturity funding basis. The matched maturity funding concept considers the origination date and the earlier of the maturity date or the repricing date of a financial instrument to assign an FTP rate for loans and deposits originated. Loans are assigned a FTP rate for funds used and deposits are assigned a FTP rate for funds provided. Certain indirect expenses are allocated to segments. These include support unit expenses such as technology, operations and other support functions.
Earnings Per Share (EPS)	Earnings Per Common Share (“EPS”) EPS is calculated utilizing the two-class method. The two-class method is an earnings allocation formula that determines earnings per share of each class of stock according to dividends and participation rights in undistributed earnings. Share‑based awards that entitle holders to receive non-forfeitable dividends before vesting are considered participating securities (i.e. nonvested restricted stock units), not subject to performance-based measures. These participating securities are included in the earnings allocation for computing basic earnings per share under this method. Undistributed income is allocated to common shareholders and participating securities under the two-class method based upon the proportion of each to the total weighted average shares available. Under the two-class method, basic earnings per common share is computed by dividing net income available to common shareholders by the weighted-average number of common shares outstanding. Diluted earnings per common share is computed using the weighted-average number of shares determined for the basic earnings per common share computation plus the dilutive effect on common shares outstanding, using the treasury stock method.
Comprehensive Income	Comprehensive Income Comprehensive income is defined as all changes in equity, except for those resulting from transactions with shareholders. Net income is a component of comprehensive income. All other components are referred to in the aggregate as other comprehensive income (loss). Other comprehensive income (loss) includes the after-tax effect of net changes in the fair value of securities available for sale, net changes in fair value of cash flow hedges and net changes in defined benefit pension plan obligations.
Guarantees	Guarantees Standby letters of credit are considered a guarantee of the Corporation. Standby letters of credit are conditional commitments issued to guarantee the performance of a customer to a third party. The credit risk involved in issuing standby letters of credit is essentially the same as that involved in extending loan facilities to customers. Under the standby letters of credit, the Corporation is required to make payments to the beneficiary of the letters of credit upon request by the beneficiary contingent upon the customer’s failure to perform under the terms of the underlying contract with the beneficiary.
Derivative Insturments and Hedging Activities	Derivative Instruments and Hedging Activities Derivatives are recognized as either assets or liabilities on the balance sheet and are measured at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative and resulting designation. For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of the derivative are recorded in other comprehensive income (loss) and subsequently reclassified to earnings when gains or losses are realized. The ineffective portion of changes in the fair value is recognized directly in earnings as interest income or interest expense based on the item being hedged. For derivatives not designated as hedges, changes in fair value of the derivative instruments are recognized in earnings, in noninterest income. The accrued net settlements on derivatives that qualify for hedge accounting are recorded in interest income or interest expense based on the item being hedged. Changes in fair value of derivatives, including accrued net settlements that do not qualify for hedge accounting, are reported in noninterest income. When a cash flow hedge is discontinued, but the hedged cash flows or forecasted transaction is still expected to occur, changes in value that were accumulated in other comprehensive income (loss) are amortized or accreted into earnings over the same periods that the hedged transactions will affect earnings.
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. ASC Topic 820, “Fair Value Measurements and Disclosures”, establishes a framework for measuring fair value and expands disclosures about fair value measurements. The required disclosures about fair value measurements have been included in Note 15 .

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Summary of Investments	The following tables present the amortized cost, gross unrealized holding gains, gross unrealized holding losses and fair value of securities by major security type and class of security: (Dollars in thousands) December 31, 2018 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Securities Available for Sale: Obligations of U.S. government-sponsored enterprises $246,708 $442 ($4,467 ) $242,683 Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises 675,368 1,943 (16,518 ) 660,793 Obligations of states and political subdivisions 935 2 — 937 Individual name issuer trust preferred debt securities 13,307 — (1,535 ) 11,772 Corporate bonds 13,402 — (1,777 ) 11,625 Total securities available for sale $949,720 $2,387 ($24,297 ) $927,810 Held to Maturity: Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises $10,415 $— ($99 ) $10,316 Total securities held to maturity 10,415 — (99 ) 10,316 Total securities $960,135 $2,387 ($24,396 ) $938,126 (Dollars in thousands) December 31, 2017 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Securities Available for Sale: Obligations of U.S. government-sponsored enterprises $161,479 $— ($3,875 ) $157,604 Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises 594,944 3,671 (7,733 ) 590,882 Obligations of states and political subdivisions 2,355 4 — 2,359 Individual name issuer trust preferred debt securities 18,106 — (1,122 ) 16,984 Corporate bonds 13,917 13 (805 ) 13,125 Total securities available for sale $790,801 $3,688 ($13,535 ) $780,954 Held to Maturity: Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises $12,541 $180 $— $12,721 Total securities held to maturity 12,541 180 — 12,721 Total securities $803,342 $3,868 ($13,535 ) $793,675
Securities by Contractual Maturity	The schedule of maturities of debt securities available for sale and held to maturity is presented below. Mortgage-backed securities are included based on weighted average maturities, adjusted for anticipated prepayments. All other debt securities are included based on contractual maturities. Actual maturities may differ from amounts presented because certain issuers have the right to call or prepay obligations with or without call or prepayment penalties. (Dollars in thousands) Available for Sale Held to Maturity December 31, 2018 Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $69,070 $67,584 $1,329 $1,317 Due after one year to five years 328,420 321,760 4,396 4,354 Due after five years to ten years 337,589 329,330 3,580 3,546 Due after ten years 214,641 209,136 1,110 1,099 Total securities $949,720 $927,810 $10,415 $10,316 Included in the above table are debt securities with an amortized cost balance of $273.1 million and a fair value of $265.8 million at December 31, 2018 that are callable at the discretion of the issuers. Final maturities of the callable securities range from 5 months to 18 years, with call features ranging from 1 month to 3 years.
Securities in a Continuous Unrealized Loss Position	The following tables summarize temporarily impaired securities, segregated by length of time the securities have been in a continuous unrealized loss position: (Dollars in thousands) Less than 12 Months 12 Months or Longer Total December 31, 2018 # Fair Value Unrealized Losses # Fair Value Unrealized Losses # Fair Value Unrealized Losses Obligations of U.S. government-sponsored enterprises — $— $— 16 $157,032 ($4,467 ) 16 $157,032 ($4,467 ) Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises 10 47,060 (439 ) 51 438,701 (16,178 ) 61 485,761 (16,617 ) Individual name issuer trust preferred debt securities — — — 5 11,772 (1,535 ) 5 11,772 (1,535 ) Corporate bonds 3 1,198 (9 ) 5 10,427 (1,768 ) 8 11,625 (1,777 ) Total temporarily impaired securities 13 $48,258 ($448 ) 77 $617,932 ($23,948 ) 90 $666,190 ($24,396 ) (Dollars in thousands) Less than 12 Months 12 Months or Longer Total December 31, 2017 # Fair Value Unrealized Losses # Fair Value Unrealized Losses # Fair Value Unrealized Losses Obligations of U.S. government-sponsored enterprises 8 $69,681 ($798 ) 8 $87,923 ($3,077 ) 16 $157,604 ($3,875 ) Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises 20 128,965 (613 ) 22 279,693 (7,120 ) 42 408,658 (7,733 ) Individual name issuer trust preferred debt securities — — — 7 16,984 (1,122 ) 7 16,984 (1,122 ) Corporate bonds 3 921 (5 ) 3 10,980 (800 ) 6 11,901 (805 ) Total temporarily impaired securities 31 $199,567 ($1,416 ) 40 $395,580 ($12,119 ) 71 $595,147 ($13,535 )

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Summary of Loans	The following is a summary of loans: (Dollars in thousands) December 31, 2018 December 31, 2017 Amount % Amount % Commercial: Commercial real estate (1) $1,392,408 38 % $1,210,495 36 % Commercial & industrial (2) 620,704 17 612,334 18 Total commercial 2,013,112 55 1,822,829 54 Residential Real Estate: Residential real estate (3) 1,360,387 37 1,227,248 36 Consumer: Home equity 280,626 8 292,467 9 Other (4) 26,235 — 31,527 1 Total consumer 306,861 8 323,994 10 Total loans (5) $3,680,360 100 % $3,374,071 100 % (1) Consists of commercial mortgages primarily secured by income-producing property, as well as construction and development loans. Construction and development loans are made to businesses for land development or the on-site construction of industrial, commercial, or residential buildings. (2) Consists of loans to businesses and individuals, a substantial portion of which are fully or partially collateralized by real estate. (3) Consists of mortgage and homeowner construction loans secured by one- to four- family residential properties. (4) Consists of loans to individuals secured by general aviation aircraft and other personal installment loans. (5) Includes net unamortized loan origination costs of $4.7 million and $3.8 million , respectively, at December 31, 2018 and 2017 and net unamortized premiums on purchased loans of $703 thousand and $878 thousand , respectively, at December 31, 2018 and 2017 .
Past Due Loans	The following tables present an aging analysis of past due loans, segregated by class of loans: (Dollars in thousands) Days Past Due December 31, 2018 30-59 60-89 Over 90 Total Past Due Current Total Loans Commercial: Commercial real estate $155 $925 $— $1,080 $1,391,328 $1,392,408 Commercial & industrial — — — — 620,704 620,704 Total commercial 155 925 — 1,080 2,012,032 2,013,112 Residential Real Estate: Residential real estate 6,318 2,693 1,509 10,520 1,349,867 1,360,387 Consumer: Home equity 1,281 156 552 1,989 278,637 280,626 Other 33 — — 33 26,202 26,235 Total consumer 1,314 156 552 2,022 304,839 306,861 Total loans $7,787 $3,774 $2,061 $13,622 $3,666,738 $3,680,360 (Dollars in thousands) Days Past Due December 31, 2017 30-59 60-89 Over 90 Total Past Due Current Total Loans Commercial: Commercial real estate $6 $— $4,954 $4,960 $1,205,535 $1,210,495 Commercial & industrial 3,793 2 281 4,076 608,258 612,334 Total commercial 3,799 2 5,235 9,036 1,813,793 1,822,829 Residential Real Estate: Residential real estate 1,678 2,274 3,903 7,855 1,219,393 1,227,248 Consumer: Home equity 2,798 75 268 3,141 289,326 292,467 Other 29 — 14 43 31,484 31,527 Total consumer 2,827 75 282 3,184 320,810 323,994 Total loans $8,304 $2,351 $9,420 $20,075 $3,353,996 $3,374,071
Impaired Loans	The following is a summary of impaired loans: (Dollars in thousands) Recorded Investment (1) Unpaid Principal Related Allowance December 31, 2018 2017 2018 2017 2018 2017 No Related Allowance Recorded Commercial: Commercial real estate $925 $— $926 $— $— $— Commercial & industrial 4,681 4,986 4,732 5,081 — — Total commercial 5,606 4,986 5,658 5,081 — — Residential Real Estate: Residential real estate 9,347 9,069 9,695 9,256 — — Consumer: Home equity 1,360 557 1,360 557 — — Other — 14 — 14 — — Total consumer 1,360 571 1,360 571 — — Subtotal 16,313 14,626 16,713 14,908 — — With Related Allowance Recorded Commercial: Commercial real estate $— $4,954 $— $9,910 $— $1,018 Commercial & industrial 52 191 73 212 — 1 Total commercial 52 5,145 73 10,122 — 1,019 Residential Real Estate: Residential real estate 364 715 390 741 100 104 Consumer: Home equity 85 — 85 — 24 — Other 22 133 22 132 3 6 Total consumer 107 133 107 132 27 6 Subtotal 523 5,993 570 10,995 127 1,129 Total impaired loans $16,836 $20,619 $17,283 $25,903 $127 $1,129 Total: Commercial $5,658 $10,131 $5,731 $15,203 $— $1,019 Residential real estate 9,711 9,784 10,085 9,997 100 104 Consumer 1,467 704 1,467 703 27 6 Total impaired loans $16,836 $20,619 $17,283 $25,903 $127 $1,129 (1) The recorded investment in impaired loans consists of unpaid principal balance, net of charge-offs, interest payments received applied to principal and unamortized deferred loan origination fees and costs. For accruing impaired loans (troubled debt restructurings for which management has concluded that the collectability of the loan is not in doubt), the recorded investment also includes accrued interest. The following table presents the average recorded investment balance of impaired loans and interest income recognized on impaired loans segregated by loan class: (Dollars in thousands) Average Recorded Investment Interest Income Recognized Years ended December 31, 2018 2017 2016 2018 2017 2016 Commercial: Commercial real estate $1,050 $8,425 $13,201 $— $79 $239 Commercial & industrial 5,403 6,445 3,540 259 281 99 Total commercial 6,453 14,870 16,741 259 360 338 Residential real estate: Residential real estate 9,645 14,571 12,848 393 444 322 Consumer: Home equity 1,182 685 1,587 52 31 48 Other 69 143 147 5 10 11 Total consumer 1,251 828 1,734 57 41 59 Totals $17,349 $30,269 $31,323 $709 $845 $719
Nonaccrual Loans	The following is a summary of nonaccrual loans, segregated by class of loans: (Dollars in thousands) December 31, 2018 2017 Commercial: Commercial real estate $925 $4,954 Commercial & industrial — 283 Total commercial 925 5,237 Residential Real Estate: Residential real estate 9,346 9,414 Consumer: Home equity 1,436 544 Other — 16 Total consumer 1,436 560 Total nonaccrual loans $11,707 $15,211 Accruing loans 90 days or more past due $— $—
Credit Quality Indicators - Commercial	The following table presents the commercial loan portfolio, segregated by category of credit quality indicator: (Dollars in thousands) Pass Special Mention Classified December 31, 2018 2017 2018 2017 2018 2017 Commercial: Commercial real estate $1,387,666 $1,205,381 $205 $— $4,537 $5,114 Commercial & industrial 559,019 592,749 50,426 9,804 11,259 9,781 Total commercial $1,946,685 $1,798,130 $50,631 $9,804 $15,796 $14,895
Credit Quality Indicators - Residential & Consumer	The following table presents the residential and consumer loan portfolios, segregated by loan type and credit quality indicator: (Dollars in thousands) Current Past Due December 31, 2018 2017 2018 2017 Residential Real Estate: Self-originated mortgages $1,238,402 $1,091,291 $9,079 $6,413 Purchased mortgages 111,465 128,102 1,441 1,442 Total residential real estate $1,349,867 $1,219,393 $10,520 $7,855 Consumer: Home equity $278,637 $289,326 $1,989 $3,141 Other 26,202 31,484 33 43 Total consumer $304,839 $320,810 $2,022 $3,184
Analysis of Loan Servicing Rights	The following table presents an analysis of loan servicing rights: (Dollars in thousands) Loan Servicing Rights Valuation Allowance Total Balance at December 31, 2015 $3,348 ($1 ) $3,347 Loan servicing rights capitalized 1,412 — 1,412 Amortization (1,267 ) — (1,267 ) Decrease in impairment reserve — 1 1 Balance at December 31, 2016 3,493 — 3,493 Loan servicing rights capitalized 1,104 — 1,104 Amortization (984 ) — (984 ) Balance at December 31, 2017 3,613 — 3,613 Loan servicing rights capitalized 905 — 905 Amortization (867 ) — (867 ) Balance at December 31, 2018 $3,651 $— $3,651
Amortization Expense Related to Loan Servicing Assets	The following table presents estimated aggregate amortization expense related to loan servicing assets: (Dollars in thousands) Years ending December 31: 2019 $768 2020 606 2021 479 2022 378 2023 299 2024 and thereafter 1,121 Total estimated amortization expense $3,651
Loans Serviced for Others, by Type of Loan	The following table presents the balance of loans serviced for others by type of loan: (Dollars in thousands) December 31, 2018 2017 Residential mortgages $588,534 $568,311 Commercial loans 142,218 108,539 Total $730,752 $676,850

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Allowance for Loan Losses Rollforward Analysis	The following table presents the activity in the allowance for loan losses for the year ended December 31, 2018 : (Dollars in thousands) Commercial Consumer CRE (1) C&I (2) Total Commercial Residential Real Estate Home Equity Other Total Consumer Total Beginning Balance $12,729 $5,580 $18,309 $5,427 $2,412 $340 $2,752 $26,488 Charge-offs (627 ) (10 ) (637 ) (250 ) (193 ) (107 ) (300 ) (1,187 ) Recoveries 25 119 144 21 29 27 56 221 Provision 3,254 158 3,412 (1,211 ) (645 ) (6 ) (651 ) 1,550 Ending Balance $15,381 $5,847 $21,228 $3,987 $1,603 $254 $1,857 $27,072 (1) Commercial real estate loans. (2) Commercial & industrial loans. The following table presents the activity in the allowance for loan losses for the year ended December 31, 2017 : (Dollars in thousands) Commercial Consumer CRE (1) C&I (2) Total Commercial Residential Real Estate Home Equity Other Total Consumer Total Beginning Balance $11,166 $6,992 $18,158 $5,252 $1,889 $705 $2,594 $26,004 Charge-offs (1,867 ) (336 ) (2,203 ) (74 ) (79 ) (106 ) (185 ) (2,462 ) Recoveries 82 169 251 39 33 23 56 346 Provision 3,348 (1,245 ) 2,103 210 569 (282 ) 287 2,600 Ending Balance $12,729 $5,580 $18,309 $5,427 $2,412 $340 $2,752 $26,488 (1) Commercial real estate loans. (2) Commercial & industrial loans. The following table presents the activity in the allowance for loan losses for the year ended December 31, 2016 : (Dollars in thousands) Commercial Consumer CRE (1) C&I (2) Total Commercial Residential Real Estate Home Equity Other Total Consumer Total Beginning Balance $10,898 $8,202 $19,100 $5,460 $1,915 $594 $2,509 $27,069 Charge-offs (5,816 ) (759 ) (6,575 ) (200 ) (147 ) (90 ) (237 ) (7,012 ) Recoveries 56 156 212 11 37 37 74 297 Provision 6,028 (607 ) 5,421 (19 ) 84 164 248 5,650 Ending Balance $11,166 $6,992 $18,158 $5,252 $1,889 $705 $2,594 $26,004 (1) Commercial real estate loans. (2) Commercial & industrial loans.
Schedule of Allowance for Loan Loss by Segment & Impairment Methodology	The following table presents the Corporation’s loan portfolio and associated allowance for loan losses by portfolio segment and by impairment methodology. (Dollars in thousands) December 31, 2018 December 31, 2017 Related Allowance Related Allowance Loans Loans Loans Individually Evaluated For Impairment Commercial: Commercial real estate $925 $— $4,954 $1,018 Construction & industrial 4,714 — 5,157 1 Total commercial 5,639 — 10,111 1,019 Residential Real Estate: Residential real estate 9,710 100 9,783 104 Consumer: Home equity 1,445 24 557 — Other 22 3 147 6 Total consumer 1,467 27 704 6 Subtotal 16,816 127 20,598 1,129 Loans Collectively Evaluated For Impairment Commercial: Commercial real estate 1,391,483 15,381 1,205,541 11,711 Commercial & industrial 615,990 5,847 607,177 5,579 Total commercial 2,007,473 21,228 1,812,718 17,290 Residential Real Estate: Residential real estate 1,350,677 3,887 1,217,465 5,323 Consumer: Home equity 279,182 1,579 291,910 2,412 Other 26,212 251 31,380 334 Total consumer 305,394 1,830 323,290 2,746 Subtotal 3,663,544 26,945 3,353,473 25,359 Total $3,680,360 $27,072 $3,374,071 $26,488

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Summary of Premises and Equipment	The following presents a summary of premises and equipment: (Dollars in thousands) December 31, 2018 2017 Land $6,020 $6,020 Premises and improvements 40,210 38,793 Furniture, fixtures and equipment 24,798 26,240 Total premises and equipment 71,028 71,053 Less accumulated depreciation 42,023 42,720 Total premises and equipment, net $29,005 $28,333

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Carrying Value of Goodwill	The following table presents the carrying value of goodwill at the reporting unit (or business segment) level: (Dollars in thousands) December 31, 2018 2017 Commercial Banking Segment $22,591 $22,591 Wealth Management Services Segment 41,318 41,318 Balance at December 31, 2018 $63,909 $63,909
Schedule of Carrying Value of Other Intangible Assets	The following table presents the components of intangible assets: (Dollars in thousands) December 31, 2018 2017 Gross carrying amount $20,803 $20,803 Accumulated amortization 12,641 11,663 Net amount $8,162 $9,140
Schedule of Estimated Annual Amortization Expense	The following table presents estimated annual amortization expense for intangible assets at December 31, 2018 : (Dollars in thousands) Years ending December 31, 2019 $944 2020 914 2021 890 2022 860 2023 843 2024 and thereafter 3,711

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense	The following table presents the components of income tax expense: (Dollars in thousands) Years ended December 31, 2018 2017 2016 Current tax expense: Federal $15,460 $23,827 $19,444 State 2,863 2,201 2,061 Total current tax expense 18,323 26,028 21,505 Deferred tax expense (benefit): Federal 63 5,717 796 State (126 ) (30 ) 72 Total deferred tax (benefit) expense (63 ) 5,687 868 Total income tax expense $18,260 $31,715 $22,373
Schedule of Effective Income Tax Rate Reconciliation	Total income tax expense varies from the amount determined by applying the Federal income tax rate to income before income taxes. The following table presents the reasons for the differences: (Dollars in thousands) 2018 2017 2016 Years ended December 31, Amount Rate Amount Rate Amount Rate Tax expense at Federal statutory rate $18,205 21.0 % $27,174 35.0 % $24,099 35.0 % (Decrease) increase in taxes resulting from: Tax-exempt income, net (809 ) (0.9 ) (1,313 ) (1.7 ) (1,599 ) (2.3 ) Dividends received deduction (45 ) (0.1 ) (55 ) (0.1 ) (58 ) (0.1 ) BOLI (461 ) (0.5 ) (757 ) (0.9 ) (930 ) (1.3 ) Share-based compensation (444 ) (0.5 ) (481 ) (0.6 ) — — Federal tax credits (364 ) (0.4 ) (364 ) (0.5 ) (364 ) (0.5 ) Change in fair value of contingent consideration (39 ) (0.1 ) (225 ) (0.3 ) (314 ) (0.5 ) State income tax expense, net of federal tax benefit 2,162 2.5 1,411 1.8 1,387 2.0 Adjustment to net deferred tax assets for enacted changes in federal tax law — — 6,170 7.9 — — Other 55 0.1 155 0.2 152 0.2 Total income tax expense $18,260 21.1 % $31,715 40.8 % $22,373 32.5 %
Schedule of Deferred Tax Assets and Liabilities	The following table presents the approximate tax effects of temporary differences that give rise to deferred tax assets and deferred tax liabilities: (Dollars in thousands) December 31, 2018 2017 Deferred tax assets: Allowance for loan losses $6,362 $6,225 Defined benefit pension obligations 420 1,767 Deferred compensation 3,688 3,334 Deferred loan origination fees 1,410 1,325 Share-based compensation 1,124 1,240 Net unrealized losses on securities available for sale 5,149 2,314 Other 1,917 2,281 Deferred tax assets 20,070 18,486 Deferred tax liabilities: Amortization of intangibles (1,918 ) (2,148 ) Deferred loan origination costs (3,897 ) (3,550 ) Loan servicing rights (858 ) (849 ) Other (1,120 ) (1,200 ) Deferred tax liabilities (7,793 ) (7,747 ) Net deferred tax asset $12,277 $10,739

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2018
Deposits [Abstract]
Summary of Deposits	The following table presents a summary of deposits: (Dollars in thousands) December 31, 2018 2017 Noninterest-bearing demand deposits $603,216 $578,410 Interest-bearing demand deposits 178,733 82,728 NOW accounts 466,568 466,605 Money market accounts 646,878 731,345 Savings accounts 373,545 368,524 Time deposits (1) 1,255,108 1,015,095 Total deposits $3,524,048 $3,242,707 (1) Includes wholesale brokered time deposits.
Schedule of Time Certificates of Deposit Maturities	The following table presents scheduled maturities of time certificates of deposit: (Dollars in thousands) Scheduled Maturity Weighted Average Rate Years ending December 31: 2019 $688,862 1.78 % 2020 350,963 2.14 2021 76,248 2.04 2022 102,934 2.43 2023 35,872 1.96 2024 and thereafter 229 1.14 Balance at December 31, 2018 $1,255,108 1.95 %
Schedule of Time Certificates of Deposit $100 Thousand or More Maturities	The following table presents the amount of time certificates of deposit in denominations of $100 thousand or more at December 31, 2018 , maturing during the periods indicated: (Dollars in thousands) January 1, 2019 to March 31, 2019 $39,014 April 1, 2019 to June 30, 2019 30,839 July 1, 2019 to December 31, 2019 45,508 January 1, 2020 and beyond 338,214 Balance at December 31, 2018 $453,575

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
FHLB Advances Maturity Summary	The following table presents maturities and weighted average interest rates on FHLB advances outstanding as of December 31, 2018 : (Dollars in thousands) Scheduled Maturity Weighted Average Rate 2019 $767,258 2.49 % 2020 67,033 2.00 2021 46,222 2.65 2022 55,447 3.65 2023 9,428 4.01 2024 and thereafter 5,334 5.06 Total $950,722 2.56 %
Schedule of Short-Term FHLB Advances	The following table presents certain information concerning short-term FHLB advances: (Dollars in thousands) As of and for the years ended December 31, 2018 2017 2016 Average amount outstanding during the period $484,090 $351,692 $275,533 Amount outstanding at end of period 630,000 367,500 352,500 Highest month end balance during period 630,000 417,500 367,500 Weighted-average interest rate at end of period 2.67 % 1.57 % 0.79 % Weighted-average interest rate during the period 2.23 1.20 0.73

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Regulatory Capital Requirements	The following table presents the Corporation’s and the Bank’s actual capital amounts and ratios, as well as the corresponding minimum and well capitalized regulatory amounts and ratios that were in effect during the respective periods: (Dollars in thousands) Actual For Capital Adequacy Purposes To Be “Well Capitalized” Under Prompt Corrective Action Regulations Amount Ratio Amount Ratio Amount Ratio December 31, 2018 Total Capital (to Risk-Weighted Assets): Corporation $455,699 12.56 % $290,146 8.00 % N/A N/A Bank 453,033 12.49 290,128 8.00 $362,660 10.00 % Tier 1 Capital (to Risk-Weighted Assets): Corporation 428,338 11.81 217,609 6.00 N/A N/A Bank 425,672 11.74 217,596 6.00 290,128 8.00 Common Equity Tier 1 Capital (to Risk-Weighted Assets): Corporation 406,340 11.20 163,207 4.50 N/A N/A Bank 425,672 11.74 163,197 4.50 235,729 6.50 Tier 1 Capital (to Average Assets): (1) Corporation 428,338 8.89 192,690 4.00 N/A N/A Bank 425,672 8.84 192,652 4.00 240,815 5.00 December 31, 2017 Total Capital (to Risk-Weighted Assets): Corporation 416,038 12.45 267,365 8.00 N/A N/A Bank 413,593 12.38 267,338 8.00 334,172 10.00 Tier 1 Capital (to Risk-Weighted Assets): Corporation 389,289 11.65 200,524 6.00 N/A N/A Bank 386,844 11.58 200,503 6.00 267,338 8.00 Common Equity Tier 1 Capital (to Risk-Weighted Assets): Corporation 367,291 10.99 150,383 4.50 N/A N/A Bank 386,844 11.58 150,378 4.50 217,212 6.50 Tier 1 Capital (to Average Assets): (1) Corporation 389,289 8.79 177,089 4.00 N/A N/A Bank 386,844 8.74 177,048 4.00 221,310 5.00 (1) Leverage ratio.

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivatives by Balance Sheet Location	The following table presents the fair values of derivative instruments in the Corporation’s Consolidated Balance Sheets: (Dollars in thousands) Asset Derivatives Liability Derivatives Fair Value Fair Value Balance Sheet Location Dec 31, Dec 31, Balance Sheet Location Dec 31, Dec 31, Derivatives Designated as Cash Flow Hedging Instruments: Interest rate risk management contracts: Interest rate caps Other assets $20 $25 Other liabilities $— $— Interest rate swaps Other assets 903 213 Other liabilities — 14 Interest rate floors Other assets 37 110 Other liabilities — — Derivatives not Designated as Hedging Instruments: Loan related derivative contracts: Interest rate swaps with customers Other assets — 268 Other liabilities 2,379 1,295 Mirror swaps with counterparties Other assets 2,200 1,152 Other liabilities — 268 Risk participation agreements Other assets — — Other liabilities — — Foreign exchange contracts Other assets — — Other liabilities 7 26 Forward loan commitments: Interest rate lock commitments Other assets 806 965 Other liabilities — 20 Forward sale commitments Other assets — 26 Other liabilities 816 1,424 Total $3,966 $2,759 $3,202 $3,047
Derivative Instruments Effect in Statements of Income and Changes in Shareholders' Equity	The following tables present the effect of derivative instruments in the Corporation’s Consolidated Statements of Changes in Shareholders’ Equity and Consolidated Statements of Income: (Dollars in thousands) Gain (Loss) Recognized in Other Comprehensive Income, Net of Tax (Effective Portion) Years ended December 31, 2018 2017 2016 Derivatives Designated as Cash Flow Hedging Instruments: Interest rate risk management contracts: Interest rate caps $30 ($64 ) ($33 ) Interest rate swaps 515 358 (224 ) Interest rate floors 74 (346 ) — Total $619 ($52 ) ($257 ) (Dollars in thousands) Amount of Gain (Loss) Recognized in Income on Derivatives Years ended December 31, Statement of Income Location 2018 2017 2016 Derivatives not Designated as Hedging Instruments: Loan related derivative contracts: Interest rate swaps with customers Loan related derivative income ($290 ) $2,243 ($598 ) Mirror swaps with counterparties Loan related derivative income 2,709 1,198 3,854 Risk participation agreements Loan related derivative income (27 ) (233 ) (13 ) Foreign exchange contracts Loan related derivative income 69 6 — Forward loan commitments: Interest rate lock commitments Mortgage banking revenues (139 ) (100 ) (175 ) Forward sale commitments Mortgage banking revenues 997 (328 ) 942 Total $3,319 $2,786 $4,010

Balance Sheet Offsetting (Table

Balance Sheet Offsetting (Tables)	12 Months Ended
	Dec. 31, 2018
Balance Sheet Offsetting [Abstract]
Balance Sheet Offsetting	The following table presents the Corporation’s derivative asset and derivative liability positions and the effect of netting arrangements on the Consolidated Balance Sheets: (Dollars in thousands) December 31, 2018 December 31, 2017 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Derivatives Designated as Cash Flow Hedging Instruments: Interest rate risk management contracts: Interest rate caps $20 $— $25 $— Interest rate swaps 903 — 213 14 Interest rate floors 37 — 110 — Derivatives not Designated as Hedging Instruments: Loan related derivative contracts: Interest rate swaps with customers 5,340 7,719 2,857 3,884 Mirror swaps with counterparties 7,592 5,392 3,801 2,917 Foreign exchange contracts — 7 — 26 Gross amounts 13,892 13,118 7,006 6,841 Less amounts offset in Consolidated Balance Sheets 10,732 10,732 5,238 5,238 Net amounts presented in Consolidated Balance Sheets 3,160 2,386 1,768 1,603 Less collateral pledged (1) — 1,460 — 1,039 Net amounts $3,160 $926 $1,768 $564 (1) Collateral pledged to derivative counterparties in the form of cash. Washington Trust may need to post additional collateral in the future in proportion to potential increases in unrealized loss positions.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair value of Mortgage Loans Held for Sale	The following table presents a summary of mortgage loans held for sale accounted for under the fair value option: (Dollars in thousands) December 31, 2018 2017 Aggregate fair value $20,996 $26,943 Aggregate principal balance 20,498 26,400 Difference between fair value and principal balance $498 $543
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables present the balances of assets and liabilities reported at fair value on a recurring basis: (Dollars in thousands) Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs (Level 3) December 31, 2018 Assets: Securities available for sale: Obligations of U.S. government-sponsored enterprises $242,683 $— $242,683 $— Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises 660,793 — 660,793 — Obligations of states and political subdivisions 937 — 937 — Individual name issuer trust preferred debt securities 11,772 — 11,772 — Corporate bonds 11,625 — 11,625 — Mortgage loans held for sale 20,996 — 20,996 — Derivative assets 3,966 — 3,966 — Total assets at fair value on a recurring basis $952,772 $— $952,772 $— Liabilities: Derivative liabilities $3,202 $— $3,202 $— Total liabilities at fair value on a recurring basis $3,202 $— $3,202 $— (Dollars in thousands) Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs (Level 3) December 31, 2017 Assets: Securities available for sale: Obligations of U.S. government-sponsored enterprises $157,604 $— $157,604 $— Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises 590,882 — 590,882 — Obligations of states and political subdivisions 2,359 — 2,359 — Individual name issuer trust preferred debt securities 16,984 — 16,984 — Corporate bonds 13,125 — 13,125 — Mortgage loans held for sale 26,943 — 26,943 — Derivative assets 2,759 — 2,759 — Total assets at fair value on a recurring basis $810,656 $— $810,656 $— Liabilities: Derivative liabilities $3,047 $— $3,047 $— Contingent consideration liability 1,404 — — 1,404 Total liabilities at fair value on a recurring basis $4,451 $— $3,047 $1,404
Fair Value of Contingent Consideration Rollforward	The following table presents the change in the contingent consideration liability, which is included in other liabilities in the Consolidated Balance Sheets. (Dollars in thousands) Years ended December 31, 2018 2017 Beginning Balance $1,404 $2,047 Change in fair value (187 ) (643 ) Payments (1,217 ) — Ending Balance $— $1,404
Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis	The following table presents the carrying value of assets held at December 31, 2018 , which were written down to fair value during the year ended December 31, 2018 : (Dollars in thousands) Total Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Assets: Collateral dependent impaired loans $883 $— $— $883 Property acquired through foreclosure or repossession 2,142 — — 2,142 Total assets at fair value on a nonrecurring basis $3,025 $— $— $3,025 The allowance for loan losses on collateral dependent impaired loans amounted to $24 thousand at December 31, 2018 . The following table presents the carrying value of assets held at December 31, 2017 , which were written down to fair value during the year ended December 31, 2017 : (Dollars in thousands) Total Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Assets: Collateral dependent impaired loans $1,425 $— $— $1,425 Property acquired through foreclosure or repossession 131 — — 131 Total assets at fair value on a nonrecurring basis $1,556 $— $— $1,556 The allowance for loan losses on collateral dependent impaired loans amounted to $690 thousand at December 31, 2017 .
Qualitative Information About Level 3 Assets Measured at Fair Value on a Nonrecurring Basis	The following tables present valuation techniques and unobservable inputs for assets measured at fair value on a nonrecurring basis for which the Corporation has utilized Level 3 inputs to determine fair value: (Dollars in thousands) Fair Value Valuation Technique Unobservable Input Range of Inputs Utilized (Weighted Average) December 31, 2018 Collateral dependent impaired loans $883 Appraisals of collateral Discount for costs to sell 0% - 10% (10%) Appraisal adjustments (1) 0% - 100% (2%) Property acquired through foreclosure or repossession 2,142 Appraisals of collateral Discount for costs to sell 13% Appraisal adjustments (1) 12% - 28% (20%) (1) Management may adjust appraisal values to reflect market value declines or other discounts resulting from its knowledge of the property. (Dollars in thousands) Fair Value Valuation Technique Unobservable Input Range of Inputs Utilized (Weighted Average) December 31, 2017 Collateral dependent impaired loans $1,425 Appraisals of collateral Discount for costs to sell 0% - 15% (15%) Property acquired through foreclosure or repossession 131 Appraisals of collateral Discount for costs to sell 10% Appraisal adjustments (1) 12% - 17% (15%) (1) Management may adjust appraisal values to reflect market value declines or other discounts resulting from its knowledge of the property.
Carrying Amounts, Estimated Fair Values and Fair Value Hierarchy of Financial Instruments	The estimated fair values and related carrying amounts for financial instruments for which fair value is only disclosed are presented below as of the periods indicated. The tables exclude financial instruments for which the carrying value approximates fair value such as cash and cash equivalents, FHLB stock, accrued interest receivable, bank-owned life insurance, non-maturity deposits and accrued interest payable. (Dollars in thousands) Carrying Amount Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs (Level 3) December 31, 2018 Financial Assets: Securities held to maturity $10,415 $10,316 $— $10,316 $— Loans, net of allowance for loan losses 3,653,288 3,598,025 — — 3,598,025 Financial Liabilities: Time deposits $1,255,108 $1,269,433 $— $1,269,433 $— FHLB advances 950,722 950,691 — 950,691 — Junior subordinated debentures 22,681 19,226 — 19,226 — (Dollars in thousands) Carrying Amount Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs (Level 3) December 31, 2017 Financial Assets: Securities held to maturity $12,541 $12,721 $— $12,721 $— Loans, net of allowance for loan losses 3,347,583 3,369,932 — — 3,369,932 Financial Liabilities: Time deposits $1,015,095 $1,018,396 $— $1,018,396 $— FHLB advances 791,356 792,887 — 792,887 — Junior subordinated debentures 22,681 18,559 — 18,559 —

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Disaggregation of Revenue	The following table summarizes total revenues as presented in the Consolidated Statements of Income and the related amounts which are from contracts with customers within the scope of Topic 606. As shown below, a substantial portion of our revenues are specifically excluded from the scope of Topic 606. Years ended December 31, 2018 2017 2016 (Dollars in thousands) As reported in Consolidated Statements of Income Revenue from contracts in scope of Topic 606 As reported in Consolidated Statements of Income Revenue from contracts in scope of Topic 606 As reported in Consolidated Statements of Income Revenue from contracts in scope of Topic 606 Net interest income $132,290 $— $119,531 $— $110,478 $— Noninterest income: Asset-based wealth management revenues 37,343 37,343 38,125 38,125 36,139 36,139 Transaction-based wealth management revenues 998 998 1,221 1,221 1,430 1,430 Total wealth management revenues 38,341 38,341 39,346 39,346 37,569 37,569 Mortgage banking revenues 10,381 — 11,392 — 13,183 — Service charges on deposit accounts 3,628 3,628 3,672 3,672 3,702 3,702 Card interchange fees 3,768 3,768 3,502 3,502 3,385 3,385 Income from bank-owned life insurance 2,196 — 2,161 — 2,659 — Loan related derivative income 2,461 — 3,214 — 3,243 — Other income 1,339 1,329 1,522 1,469 1,388 1,388 Total noninterest income 62,114 47,066 64,809 47,989 65,129 46,044 Total revenues $194,404 $47,066 $184,340 $47,989 $175,607 $46,044 The following table presents revenue from contracts with customers based on the timing of revenue recognition: (Dollars in thousands) Years ended December 31, 2018 2017 2016 Revenue recognized at a point in time: Card interchange fees $3,768 $3,502 $3,385 Service charges on deposit accounts 2,802 2,899 2,914 Other income 958 1,122 1,062 Revenue recognized over time: Wealth management revenues 38,341 39,346 37,569 Service charges on deposit accounts 826 773 788 Other income 371 347 326 Total revenues from contracts in scope of Topic 606 $47,066 $47,989 $46,044

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Schedule of Projected Benefit Obligations, Fair Value of Plan Assets and Funded (Unfunded) Status	The following table presents the plans’ projected benefit obligations, fair value of plan assets and funded (unfunded) status: (Dollars in thousands) Qualified Pension Plan Non-Qualified Retirement Plans At December 31, 2018 2017 2018 2017 Change in Benefit Obligation: Benefit obligation at beginning of period $80,723 $72,951 $15,203 $13,154 Service cost 2,244 2,149 108 129 Interest cost 2,715 2,673 475 428 Actuarial (gain) loss (7,830 ) 7,017 (252 ) 2,275 Benefits paid (4,344 ) (3,936 ) (908 ) (783 ) Administrative expenses (128 ) (131 ) — — Benefit obligation at end of period 73,380 80,723 14,626 15,203 Change in Plan Assets: Fair value of plan assets at beginning of period 87,364 75,787 — — Actual return on plan assets 288 12,644 — — Employer contributions 3,000 3,000 908 783 Benefits paid (4,344 ) (3,936 ) (908 ) (783 ) Administrative expenses (128 ) (131 ) — — Fair value of plan assets at end of period 86,180 87,364 — — Funded (unfunded) status at end of period $12,800 $6,641 ($14,626 ) ($15,203 )
Schedule of Components of Accumulated Other Comprehensive Income (Loss) Related to Retirements Plans	The following table presents components of accumulated other comprehensive income related to the qualified pension plan and non-qualified retirement plans, on a pre-tax basis: (Dollars in thousands) Qualified Pension Plan Non-Qualified Retirement Plans At December 31, 2018 2017 2018 2017 Net actuarial loss $9,453 $13,795 $5,785 $6,448 Prior service credit (16 ) (39 ) — (1 ) Total pre-tax amounts recognized in accumulated other comprehensive income $9,437 $13,756 $5,785 $6,447
Schedule of Net Periodic Benefit Costs and Other Amounts Recognized in Other Comprehensive Income (Loss)	The following table presents components of net periodic benefit cost and other amounts recognized in other comprehensive income (loss), on a pre-tax basis: (Dollars in thousands) Qualified Pension Plan Non-Qualified Retirement Plans Years ended December 31, 2018 2017 2016 2018 2017 2016 Net Periodic Benefit Cost: Service cost (1) $2,244 $2,149 $2,148 $108 $129 $122 Interest cost (2) 2,715 2,673 2,576 475 428 432 Expected return on plan assets (2) (5,272 ) (4,942 ) (4,633 ) — — — Amortization of prior service credit (2) (23 ) (23 ) (23 ) (1 ) (1 ) (1 ) Recognized net actuarial loss (2) 1,496 1,114 828 411 347 247 Net periodic benefit cost 1,160 971 896 993 903 800 Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (on a pre-tax basis): Net (gain) loss (4,342 ) (1,798 ) 2,904 (663 ) 1,928 127 Prior service cost 23 23 23 1 1 1 Recognized in other comprehensive (loss) income (4,319 ) (1,775 ) 2,927 (662 ) 1,929 128 Total recognized in net periodic benefit cost and other comprehensive (loss) income ($3,159 ) ($804 ) $3,823 $331 $2,832 $928 (1) Included in salaries and employee benefits expense in the Consolidated Statements of Income. (2) Included in other expenses in the Consolidated Statements of Income.
Schedule of Assumptions Used for Net Periodic Benefit Cost	The following table presents the measurement date and weighted-average assumptions used to determine benefit obligations at December 31, 2018 and 2017 : Qualified Pension Plan Non-Qualified Retirement Plans 2018 2017 2018 2017 Measurement date Dec 31, 2018 Dec 31, 2017 Dec 31, 2018 Dec 31, 2017 Discount rate 4.38% 3.69% 4.30% 3.60% Rate of compensation increase 3.75 3.75 3.75 3.75 The following table presents the measurement date and weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31, 2018 , 2017 and 2016 : Qualified Pension Plan Non-Qualified Retirement Plans 2018 2017 2016 2018 2017 2016 Measurement date Dec 31, 2017 Dec 31, 2016 Dec 31, 2015 Dec 31, 2017 Dec 31, 2016 Dec 31, 2015 Equivalent single discount rate for benefit obligations 3.69% 4.18% 4.48% 3.58% 3.96% 4.20% Equivalent single discount rate for service cost 3.76 4.29 4.63 3.79 4.25 4.59 Equivalent single discount rate for interest cost 3.42 3.73 3.88 3.22 3.36 3.44 Expected long-term return on plan assets 6.75 6.75 6.75 N/A N/A N/A Rate of compensation increase 3.75 3.75 3.75 3.75 3.75 3.75
Schedule of Fair Value and Allocation of Plan Assets	The following tables present the fair values of the qualified pension plan’s assets: (Dollars in thousands) Fair Value Measurements Using Assets at Fair Value December 31, 2018 Level 1 Level 2 Level 3 Assets: Cash and cash equivalents $25,986 $— $— $25,986 Obligations of U.S. government-sponsored enterprises — 21,787 — 21,787 Obligations of states and political subdivisions — 2,597 — 2,597 Corporate bonds — 10,361 — 10,361 Common stocks 9,957 — — 9,957 Mutual funds 15,492 — — 15,492 Total plan assets $51,435 $34,745 $— $86,180 (Dollars in thousands) Fair Value Measurements Using Assets at Fair Value December 31, 2017 Level 1 Level 2 Level 3 Assets: Cash and cash equivalents $3,760 $— $— $3,760 Obligations of U.S. government-sponsored enterprises — 5,926 — 5,926 Obligations of states and political subdivisions — 2,971 — 2,971 Corporate bonds — 13,112 — 13,112 Common stocks 38,508 — — 38,508 Mutual funds 23,087 — — 23,087 Total plan assets $65,355 $22,009 $— $87,364 The following table presents the asset allocations of the qualified pension plan, by asset category: December 31, 2018 2017 Asset Category: Cash and cash equivalents 30.2 % 4.3 % Fixed income securities 40.3 30.0 Equity securities 29.5 65.7 Total 100.0 % 100.0 %
Schedule of Expected Future Benefit Payments	The following table presents the benefit payments, which reflect expected future service, as appropriate, expected to be paid: (Dollars in thousands) Qualified Pension Plan Non-Qualified Retirement Plans 2019 $4,034 $907 2020 3,817 898 2021 3,823 886 2022 4,088 878 2023 4,091 878 Years 2024 - 2028 28,295 4,355

Share-Based Compensation Arra_2

Share-Based Compensation Arrangements (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Compensation Cost for Share-based Compensation Arrangements	The following table presents share-based compensation expense and the related income tax benefits recognized in the Consolidated Statements of Income for stock options, nonvested share units and nonvested performance share units: (Dollars in thousands) Years ended December 31, 2018 2017 2016 Share-based compensation expense $2,602 $2,577 $2,190 Related income tax benefits (1) $1,108 $1,114 $810 (1) Includes $496 thousand and $508 thousand , respectively, of excess tax benefits recognized upon the settlement of share-based compensation awards in 2018 and 2017 . See additional disclosure under the heading “Share-Based Compensation” in Note 1 .
Stock Options Fair Value Assumptions	The following presents the assumptions used in determining the grant date fair value of the stock option awards granted to certain key employees: 2018 2017 2016 Options granted 47,950 47,725 53,400 Cliff vesting period (years) 3 3 3 Expected term (years) 6.5 7.0 7.5 Expected dividend yield 3.39 % 3.57 % 3.89 % Weighted average expected volatility 22.73 % 27.10 % 29.99 % Weighted average risk-free interest rate 3.14 % 1.70 % 1.66 % Weighted average grant-date fair value $9.74 $10.60 $7.92
Stock Options Activity	The following table presents a summary of the status of Washington Trust’s stock options outstanding as of and for the year ended December 31, 2018 : Number of Stock Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (000’s) Beginning of period 223,853 $38.68 Granted 47,950 54.74 Exercised (29,738 ) 27.57 Forfeited or expired (19,450 ) 46.71 End of period 222,615 $42.92 7.15 $1,790 At end of period: Options exercisable 87,990 $31.18 4.68 $1,439 Options expected to vest in future periods 134,625 $50.60 8.76 $351
Schedule of Stock Options Outstanding and Options Exercisable	The following table presents additional information concerning options outstanding and options exercisable at December 31, 2018 : Options Outstanding Options Exercisable Exercise Price Ranges Number of Shares Weighted Average Remaining Life (Years) Weighted Average Exercise Price Number of Shares Weighted Average Exercise Price $15.01 to $20.00 6,900 1.42 $17.52 6,900 $17.52 $20.01 to $25.00 26,040 3.07 23.06 26,040 23.06 $25.01 to $30.00 — — — — — $30.01 to $35.00 22,875 4.98 32.76 22,875 32.76 $35.01 to $40.00 36,175 6.47 39.35 32,175 39.55 $40.01 to $45.00 42,850 7.80 40.25 — — $45.01 to $50.00 — — — — — $50.01 to $55.00 47,950 9.80 54.74 — — $55.01 to $60.00 39,825 8.80 58.05 — — 222,615 7.15 $42.92 87,990 $31.18
Nonvested Shares Units Activity	The following table presents a summary of the status of Washington Trust’s nonvested share units as of and for the year ended December 31, 2018 : Number of Shares Weighted Average Grant Date Fair Value Beginning of period 53,775 $43.13 Granted 13,430 55.71 Vested (18,805 ) 37.87 Forfeited (3,050 ) 47.75 End of period 45,350 $48.73
Performance Share Units Outstanding	The following table presents a summary of the performance share unit awards as of December 31, 2018 : Grant Date Fair Value per Share Current Performance Assumption Expected Number of Shares Performance share units awarded in: 2018 $54.25 140% 41,454 2017 51.85 150% 24,150 2016 36.11 140% 28,000 Total 93,604
Performance Share Units Activity	The following table presents a summary of the status of Washington Trust’s performance share units as of and for the year ended December 31, 2018 : Number of Shares Weighted Average Grant Date Fair Value Beginning of period 117,465 $41.58 Granted 41,454 54.25 Vested (36,729 ) 38.02 Forfeited (28,586 ) 42.83 End of period 93,604 $48.20

Business Segments (Tables)

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Statement of Operations and Total Assets by Reportable Segment	The following tables present the statement of operations and total assets for Washington Trust’s reportable segments: (Dollars in thousands) Year ended December 31, 2018 Commercial Banking Wealth Management Services Corporate Consolidated Total Net interest income (expense) $106,668 ($334 ) $25,956 $132,290 Provision for loan losses 1,550 — — 1,550 Net interest income (expense) after provision for loan losses 105,118 (334 ) 25,956 130,740 Noninterest income 21,509 38,341 2,264 62,114 Noninterest expenses: Depreciation and amortization expense 2,589 1,501 171 4,261 Other noninterest expenses 62,673 26,222 13,006 101,901 Total noninterest expenses 65,262 27,723 13,177 106,162 Income before income taxes 61,365 10,284 15,043 86,692 Income tax expense 13,149 2,577 2,534 18,260 Net income $48,216 $7,707 $12,509 $68,432 Total assets at period end $3,804,021 $71,254 $1,135,491 $5,010,766 Expenditures for long-lived assets 3,415 407 152 3,974 (Dollars in thousands) Year ended December 31, 2017 Commercial Banking Wealth Management Services Corporate Consolidated Total Net interest income (expense) $98,736 ($167 ) $20,962 $119,531 Provision for loan losses 2,600 — — 2,600 Net interest income (expense) after provision for loan losses 96,136 (167 ) 20,962 116,931 Noninterest income 23,244 39,346 2,219 64,809 Noninterest expenses: Depreciation and amortization expense 2,604 1,689 196 4,489 Other noninterest expenses 60,828 26,718 12,065 99,611 Total noninterest expenses 63,432 28,407 12,261 104,100 Income before income taxes 55,948 10,772 10,920 77,640 Income tax expense 23,876 3,795 4,044 31,715 Net income $32,072 $6,977 $6,876 $45,925 Total assets at period end $3,491,845 $66,083 $971,922 $4,529,850 Expenditures for long-lived assets 2,224 360 195 2,779 (Dollars in thousands) Year ended December 31, 2016 Commercial Banking Wealth Management Services Corporate Consolidated Total Net interest income $91,221 ($66 ) $19,323 $110,478 Provision for loan losses 5,650 — — 5,650 Net interest income (expense) after provision for loan losses 85,571 (66 ) 19,323 104,828 Noninterest income 24,783 37,569 2,777 65,129 Noninterest expenses: Depreciation and amortization expense 2,771 1,940 224 4,935 Other noninterest expenses 58,452 25,239 12,477 96,168 Total noninterest expenses 61,223 27,179 12,701 101,103 Income before income taxes 49,131 10,324 9,399 68,854 Income tax expense 16,790 3,692 1,891 22,373 Net income $32,341 $6,632 $7,508 $46,481 Total assets at period end $3,354,633 $64,625 $961,857 $4,381,115 Expenditures for long-lived assets 2,267 464 381 3,112

Other Comprehensive Income (L_2

Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Activity in Other Comprehensive Income (Loss)	The following tables present the activity in other comprehensive income (loss): (Dollars in thousands) Year ended December 31, 2018 Pre-tax Amounts Income Taxes Net of Tax Securities available for sale: Changes in fair value of securities available for sale ($12,063 ) ($2,835 ) ($9,228 ) Net (gains) losses on securities reclassified into earnings — — — Net change in fair value of securities available for sale (12,063 ) (2,835 ) (9,228 ) Cash flow hedges: Changes in fair value of cash flow hedges 639 151 488 Net cash flow hedge losses reclassified into earnings (1) 170 39 131 Net change in the fair value of cash flow hedges 809 190 619 Defined benefit pension plan obligations: Defined benefit pension plan obligation adjustment 3,098 729 2,369 Amortization of net actuarial losses (2) 1,907 448 1,459 Amortization of net prior service credits (2) (24 ) (6 ) (18 ) Net change in defined benefit pension plan obligations 4,981 1,171 3,810 Total other comprehensive income ($6,273 ) ($1,474 ) ($4,799 ) (1) The pre-tax amounts are included in interest expense on FHLB advances, interest expense on junior subordinated debentures and interest and fees on loans in the Consolidated Statements of Income. (2) The pre-tax amounts are included in other expenses in the Consolidated Statements of Income. (Dollars in thousands) Year ended December 31, 2017 Pre-tax Amounts Income Taxes Net of Tax Securities available for sale: Changes in fair value of securities available for sale $986 $365 $621 Net (gains) losses on securities reclassified into earnings — — — Net change in fair value of securities available for sale 986 365 621 Cash flow hedges: Changes in fair value of cash flow hedges (774 ) (223 ) (551 ) Net cash flow hedge losses reclassified into earnings (1) 792 293 499 Net change in the fair value of cash flow hedges 18 70 (52 ) Defined benefit pension plan obligations: Defined benefit pension plan obligation adjustment (1,591 ) (594 ) (997 ) Amortization of net actuarial losses (2) 1,461 546 915 Amortization of net prior service credits (2) (24 ) (9 ) (15 ) Net change in defined benefit pension plan obligations (154 ) (57 ) (97 ) Total other comprehensive income $850 $378 $472 (1) The pre-tax amounts are included in interest expense on FHLB advances, interest expense on junior subordinated debentures and interest and fees on loans in the Consolidated Statements of Income. (2) The pre-tax amounts are included in other expenses in the Consolidated Statements of Income. (Dollars in thousands) Year ended December 31, 2016 Pre-tax Amounts Income Taxes Net of Tax Securities available for sale: Changes in fair value of securities available for sale ($12,502 ) ($4,626 ) ($7,876 ) Net (gains) losses on securities reclassified into earnings — — — Net change in fair value of securities available for sale (12,502 ) (4,626 ) (7,876 ) Cash flow hedges: Changes in fair value of cash flow hedges (403 ) (146 ) (257 ) Net cash flow hedge losses reclassified into earnings — — — Net change in the fair value of cash flow hedges (403 ) (146 ) (257 ) Defined benefit pension plan obligations: Defined benefit pension plan obligation adjustment (4,106 ) (1,518 ) (2,588 ) Amortization of net actuarial losses (1) 1,075 397 678 Amortization of net prior service credits (1) (24 ) (9 ) (15 ) Net change in defined benefit pension plan obligations (3,055 ) (1,130 ) (1,925 ) Total other comprehensive loss ($15,960 ) ($5,902 ) ($10,058 ) (1) The pre-tax amounts are included in other expense in the Consolidated Statements of Income.
Changes in Components of Accumulated Other Comprehensive Income (Loss)	The following tables present the changes in accumulated other comprehensive income (loss) by component, net of tax: (Dollars in thousands) Net Unrealized Losses on Available For Sale Securities Net Unrealized (Losses) Gains on Cash Flow Hedges Defined Benefit Pension Plan Adjustment Total Balance at December 31, 2017 ($7,534 ) ($428 ) ($15,548 ) ($23,510 ) Other comprehensive (loss) income before reclassifications (9,228 ) 488 2,369 (6,371 ) Amounts reclassified from accumulated other comprehensive income — 131 1,441 1,572 Net other comprehensive (loss) income (9,228 ) 619 3,810 (4,799 ) Balance at December 31, 2018 ($16,762 ) $191 ($11,738 ) ($28,309 ) (Dollars in thousands) Net Unrealized (Losses) Gains on Available For Sale Securities Net Unrealized Losses on Cash Flow Hedges Defined Benefit Pension Plan Adjustment Total Balance at December 31, 2016 ($6,825 ) ($300 ) ($12,632 ) ($19,757 ) Other comprehensive income (loss) before reclassifications 621 (551 ) (741 ) (671 ) Amounts reclassified from accumulated other comprehensive income — 499 644 1,143 Net other comprehensive income (loss) 621 (52 ) (97 ) 472 Reclassification of income tax effects due to the adoption of ASU 2018-02 (1,330 ) (76 ) (2,819 ) (4,225 ) Balance at December 31, 2017 ($7,534 ) ($428 ) ($15,548 ) ($23,510 ) (Dollars in thousands) Net Unrealized Gains (Losses) on Available For Sale Securities Net Unrealized Losses on Cash Flow Hedges Defined Benefit Pension Plan Adjustment Total Balance at December 31, 2015 $1,051 ($43 ) ($10,707 ) ($9,699 ) Other comprehensive loss before reclassifications (7,876 ) (257 ) (2,588 ) (10,721 ) Amounts reclassified from accumulated other comprehensive income — — 663 663 Net other comprehensive loss (7,876 ) (257 ) (1,925 ) (10,058 ) Balance at December 31, 2016 ($6,825 ) ($300 ) ($12,632 ) ($19,757 )

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Calculation of Earnings Per Common Share	The following table presents the calculation of earnings per common share: (Dollars and shares in thousands, except per share amounts) Years ended December 31, 2018 2017 2016 Earnings per common share - basic: Net income $68,432 $45,925 $46,481 Less dividends and undistributed earnings allocated to participating securities (144 ) (108 ) (97 ) Net income available to common shareholders $68,288 $45,817 $46,384 Weighted average common shares 17,272 17,207 17,081 Earnings per common share - basic $3.95 $2.66 $2.72 Earnings per common share - diluted: Net income $68,432 $45,925 $46,481 Less dividends and undistributed earnings allocated to participating securities (144 ) (108 ) (97 ) Net income available to common shareholders $68,288 $45,817 $46,384 Weighted average common shares 17,272 17,207 17,081 Dilutive effect of common stock equivalents 119 131 127 Weighted average diluted common shares 17,391 17,338 17,208 Earnings per common share - diluted $3.93 $2.64 $2.70 Weighted average common stock equivalents, not included in common stock equivalents above because they were anti-dilutive, totaled 55,821 , 11,572 and 59,158 for the years ended December 31, 2018 , 2017 and 2016 , respectively.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Financial Instruments with Off Balance Sheet Risk	The following table presents the contractual and notional amounts of financial instruments with off-balance sheet risk: (Dollars in thousands) December 31, 2018 2017 Financial instruments whose contract amounts represent credit risk: Commitments to extend credit: Commercial loans $533,884 $537,310 Home equity lines 270,462 254,855 Other loans 46,698 48,819 Standby letters of credit 7,706 6,666 Financial instruments whose notional amounts exceed the amount of credit risk: Forward loan commitments: Interest rate lock commitments 30,766 45,139 Forward sale commitments 61,993 71,539 Loan related derivative contracts: Interest rate swaps with customers 648,050 545,049 Mirror swaps with counterparties 648,050 545,049 Risk participation-in agreements 46,510 34,052 Foreign exchange contracts 2,784 3,005 Interest rate risk management contracts: Interest rate swaps 60,000 60,000
Schedule of Future Minimum Annual Lease Payments	The following table presents the minimum annual lease payments under the terms of these leases, exclusive of renewal provisions: (Dollars in thousands) Years ending December 31: 2019 $3,544 2020 2,980 2021 2,677 2022 2,293 2023 2,059 2024 and thereafter 22,648 Total minimum lease payments $36,201

Parent Company Financial Stat_2

Parent Company Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Parent Company Only Balance Sheet	The following tables present parent company only financial statements of the Bancorp, reflecting the investment in the Bank on the equity basis of accounting. The Statements of Changes in Shareholders’ Equity for the parent company only are identical to the Consolidated Statements of Changes in Shareholders’ Equity and are therefore not presented. Balance Sheets (Dollars in thousands, except par value) December 31, 2018 2017 Assets: Cash on deposit with bank subsidiary $1,912 $1,664 Investment in subsidiaries at equity value: Bank 467,657 433,010 Non-bank 1,869 1,821 Dividends receivable from bank subsidiary 7,762 7,770 Other assets 190 259 Total assets $479,390 $444,524 Liabilities: Junior subordinated debentures $22,681 $22,681 Dividends payable 8,439 7,087 Contingent consideration liability — 1,404 Other liabilities 86 68 Total liabilities 31,206 31,240 Shareholders’ Equity: Common stock of $.0625 par value; authorized 60,000,000 shares; issued and outstanding 17,302,037 shares in 2018 and 17,226,508 shares in 2017 1,081 1,077 Paid-in capital 119,888 117,961 Retained earnings 355,524 317,756 Accumulated other comprehensive loss (28,309 ) (23,510 ) Total shareholders’ equity 448,184 413,284 Total liabilities and shareholders’ equity $479,390 $444,524
Parent Company Only Income Statement	Statements of Income (Dollars in thousands) Years ended December 31, 2018 2017 2016 Income: Dividends from subsidiaries: Bank $32,394 $27,900 $24,442 Non-bank 24 18 114 Other income — — 1 Total income 32,418 27,918 24,557 Expenses: Interest on junior subordinated debentures 869 613 491 Legal and professional fees 187 169 98 Change in fair value of contingent consideration (187 ) (643 ) (898 ) Other 324 298 282 Total expenses 1,193 437 (27 ) Income before income taxes 31,225 27,481 24,584 Income tax benefit (expense) 284 340 (15 ) Income before equity in undistributed earnings (losses) of subsidiaries 31,509 27,821 24,569 Equity in undistributed earnings (losses) of subsidiaries: Bank 36,876 18,193 22,008 Non-bank 47 (89 ) (96 ) Net income $68,432 $45,925 $46,481
Parent Company Only Cash Flow Statement	Statements of Cash Flows (Dollars in thousands) Years ended December 31, 2018 2017 2016 Cash flow from operating activities: Net income $68,432 $45,925 $46,481 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed (earnings) losses of subsidiaries: Bank (36,876 ) (18,193 ) (22,008 ) Non-bank (47 ) 89 96 Decrease (increase) in dividend receivable 8 (1,252 ) (1,436 ) Decrease in other assets 70 72 45 Increase (decrease) in accrued expenses and other liabilities 17 22 (12 ) Change in fair value of contingent consideration liability (187 ) (643 ) (898 ) Tax benefit from stock option exercises and other equity awards 496 508 1,016 Other, net (465 ) (673 ) (1,051 ) Net cash provided by operating activities 31,448 25,855 22,233 Cash flows from financing activities: Payment of contingent consideration (1,217 ) — — Proceeds from stock option exercises and issuance of other equity awards, net of awards surrendered (671 ) 366 978 Cash dividends paid (29,312 ) (26,300 ) (24,637 ) Net cash used in financing activities (31,200 ) (25,934 ) (23,659 ) Net increase (decrease) in cash 248 (79 ) (1,426 ) Cash at beginning of year 1,664 1,743 3,169 Cash at end of year $1,912 $1,664 $1,743

Selected Quarterly Consolidat_2

Selected Quarterly Consolidated Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Consolidated Financial Data (Unaudited)	(Dollars and shares in thousands, except per share amounts) 2018 First Quarter Second Quarter Third Quarter Fourth Quarter Interest and dividend income $40,440 $43,286 $45,164 $47,517 Interest expense 8,588 10,175 11,715 13,639 Net interest income 31,852 33,111 33,449 33,878 Provision for loan losses — 400 350 800 Net interest income after provision for loan losses 31,852 32,711 33,099 33,078 Noninterest income 15,743 15,993 15,215 15,163 Noninterest expense 27,130 26,288 26,062 26,682 Income before income taxes 20,465 22,416 22,252 21,559 Income tax expense 4,254 4,742 4,741 4,523 Net income $16,211 $17,674 $17,511 $17,036 Net income available to common shareholders $16,173 $17,636 $17,475 $17,004 Weighted average common shares outstanding - basic 17,234 17,272 17,283 17,297 Weighted average common shares outstanding - diluted 17,345 17,387 17,382 17,385 Per share information: Basic earnings per common share $0.94 $1.02 $1.01 $0.98 Diluted earnings per common share $0.93 $1.01 $1.01 $0.98 Cash dividends declared per share $0.43 $0.43 $0.43 $0.47 (Dollars and shares in thousands, except per share amounts) 2017 First Quarter Second Quarter Third Quarter Fourth Quarter Interest and dividend income $35,664 $37,153 $37,869 $38,900 Interest expense 6,985 7,249 7,810 8,011 Net interest income 28,679 29,904 30,059 30,889 Provision for loan losses 400 700 1,300 200 Net interest income after provision for loan losses 28,279 29,204 28,759 30,689 Noninterest income 14,510 16,806 17,283 16,210 Noninterest expense 25,286 26,306 26,754 25,754 Income before income taxes 17,503 19,704 19,288 21,145 Income tax expense 5,721 6,505 6,326 13,163 Net income $11,782 $13,199 $12,962 $7,982 Net income available to common shareholders $11,755 $13,170 $12,934 $7,958 Weighted average common shares outstanding - basic 17,186 17,206 17,212 17,223 Weighted average common shares outstanding - diluted 17,293 17,316 17,318 17,349 Per share information: Basic earnings per common share $0.68 $0.77 $0.75 $0.46 Diluted earnings per common share $0.68 $0.76 $0.75 $0.46 Cash dividends declared per share $0.38 $0.38 $0.39 $0.39

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Line Items]
Federal Home Loan Bank Stock, redemption period, years after membership termination	5 years
Number of days overdue to be classified as nonaccrual	90 days
Troubled debt restructured loans, management determination of loans on nonaccrual status to return to accrual status, period	6 months
Time loan is reported as TDR from date of restructuring	1 year
Equity Method Investment, Number of Investments	2
Number of low-income housing complexes included in equity method investments	2
Equity Method Investee, One [Member]
Accounting Policies [Line Items]
Equity method investment, ownership percentage	99.90%
Equity Method Investee, Two [Member]
Accounting Policies [Line Items]
Equity method investment, ownership percentage	99.90%
Premises and Improvements [Member] | Minimum [Member]
Accounting Policies [Line Items]
Estimated useful life (in years)	5 years
Premises and Improvements [Member] | Maximum [Member]
Accounting Policies [Line Items]
Estimated useful life (in years)	40 years
Furniture, Fixtures and Equipment [Member] | Minimum [Member]
Accounting Policies [Line Items]
Estimated useful life (in years)	3 years
Furniture, Fixtures and Equipment [Member] | Maximum [Member]
Accounting Policies [Line Items]
Estimated useful life (in years)	20 years

Recently Issued Accounting Pr_2

Recently Issued Accounting Pronouncements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating lease right-of-use assets	$ 28,900
Operating lease liabilities	30,900
Rent-related liabilities	2,900
Reduction of deferred tax assets	222
Cumulative effect adjustment (net of taxes) on beginning retained earnings	722
Held to maturity securities amortized cost	10,415	$ 12,541
Held to maturity securities fair value	10,316	12,721
Held to Matruity securities unrealized losses	$ (99)	$ 0

Cash and Due from Banks (Narrat

Cash and Due from Banks (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Cash and Cash Equivalents [Abstract]
Average reserve deposited with the Board of Governors of the Federal Reserve Bank	$ 21.6	$ 14.1
Interest-bearing deposits in other banks	$ 33.7	$ 31.9

Securities (Narrative) (Details

Securities (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)security	Dec. 31, 2017USD ($)security
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Securities available for sale and held to maturity pledged as collateral, fair value	$ 439,700	$ 357,800
Amortized cost of callable debt securities	273,100
Fair value of callable debt securities	$ 265,800
Number of individual name issuer trust preferred securities in a continuous unrealized loss position total | security	90	71
Unrealized losses of securities in a continuous unrealized loss position total	$ 24,396	$ 13,535
Minimum [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Callable debt securities, maturity period	5 months
Callable debt securities, call feature period	1 month
Maximum [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Callable debt securities, maturity period	18 years
Callable debt securities, call feature period	3 years
Individual name issuer trust preferred debt securities [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Number of individual name issuer trust preferred securities in a continuous unrealized loss position total | security	5	7
Number of companies issuing securities in continuous unrealized loss position | security	4
Amortized cost of trust preferred securities of individual name issuers that are below investment grade	$ 6,100
Unrealized losses of trust preferred securities of individual name issuers that are below investment grade	744
Unrealized losses of securities in a continuous unrealized loss position total	$ 1,535	$ 1,122
Corporate bonds [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Number of individual name issuer trust preferred securities in a continuous unrealized loss position total | security	8	6
Unrealized losses of securities in a continuous unrealized loss position total	$ 1,777	$ 805

Securities (Summary of Investme

Securities (Summary of Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Available for sale securities amortized cost	$ 949,720	$ 790,801
Available for sale securities unrealized gains	2,387	3,688
Available for sale securities unrealized losses	(24,297)	(13,535)
Available for sale, at fair value	927,810	780,954
Held to maturity securities amortized cost	10,415	12,541
Held to maturity securities unrealized gains	0	180
Held to Matruity securities unrealized losses	(99)	0
Held to maturity securities fair value	10,316	12,721
Total securities amortized cost	960,135	803,342
Total securities unrealized gains	2,387	3,868
Total securities unrealized losses	(24,396)	(13,535)
Total securities fair value	938,126	793,675
Available for sale securities amortized cost	949,720
Obligations of U.S. government-sponsored enterprises [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Available for sale securities amortized cost	246,708	161,479
Available for sale securities unrealized gains	442	0
Available for sale securities unrealized losses	(4,467)	(3,875)
Available for sale, at fair value	242,683	157,604
Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Available for sale securities amortized cost	675,368	594,944
Available for sale securities unrealized gains	1,943	3,671
Available for sale securities unrealized losses	(16,518)	(7,733)
Available for sale, at fair value	660,793	590,882
Held to maturity securities amortized cost	10,415	12,541
Held to maturity securities unrealized gains	0	180
Held to Matruity securities unrealized losses	(99)	0
Held to maturity securities fair value	10,316	12,721
Obligations of states and political subdivisions [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Available for sale securities amortized cost	935	2,355
Available for sale securities unrealized gains	2	4
Available for sale securities unrealized losses	0	0
Available for sale, at fair value	937	2,359
Individual name issuer trust preferred debt securities [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Available for sale securities amortized cost	13,307	18,106
Available for sale securities unrealized gains	0	0
Available for sale securities unrealized losses	(1,535)	(1,122)
Available for sale, at fair value	11,772	16,984
Corporate bonds [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Available for sale securities amortized cost	13,402	13,917
Available for sale securities unrealized gains	0	13
Available for sale securities unrealized losses	(1,777)	(805)
Available for sale, at fair value	$ 11,625	$ 13,125

Securities (Securities by Contr

Securities (Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Available for sale debt securities maturities wIthin 1 year amortized cost	$ 69,070
Available for sale debt securities maturities 1-5 years amortized cost	328,420
Available for sale debt securities maturities 5-10 years amortized cost	337,589
Available for sale debt securities maturities after 10 years amortized cost	214,641
Available for sale securities amortized cost	949,720
Available for sale debt securities maturities within 1 year fair value	67,584
Available for sale debt securities maturities 1-5 years fair value	321,760
Available for sale debt securities maturities 5-10 years fair value	329,330
Available for sale debt securities maturities after 10 years fair value	209,136
Available for sale debt securities fair value	927,810
Held to maturity debt securities maturities within 1 year amortized cost	1,329
Held to maturity debt securities maturities 1-5 years amortized cost	4,396
Held to maturity debt securities maturities 5-10 years amortized cost	3,580
Held to maturity debt securities maturities after 10 years amortized cost	1,110
Held to maturity securities amortized cost	10,415	$ 12,541
Held to maturity debt securities maturities within 1 year fair value	1,317
Held to maturity debt securities maturities 1-5 years fair value	4,354
Held to maturity debt securities maturities 5-10 years fair value	3,546
Held to maturity debt securities maturities after 10 years fair value	1,099
Held to maturity securities fair value	10,316	12,721
Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Held to maturity securities amortized cost	10,415	12,541
Held to maturity securities fair value	$ 10,316	$ 12,721

Securities (Securities in a Con

Securities (Securities in a Continuous Unrealized Loss Position) (Details) $ in Thousands	Dec. 31, 2018USD ($)security	Dec. 31, 2017USD ($)security
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	13	31
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 48,258	$ 199,567
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ (448)	$ (1,416)
Number of securities in a continuous unrealized loss position for 12 months or longer | security	77	40
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 617,932	$ 395,580
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (23,948)	$ (12,119)
Number of individual name issuer trust preferred securities in a continuous unrealized loss position total | security	90	71
Fair value of securities in a continuous unrealized loss position total	$ 666,190	$ 595,147
Unrealized losses of securities in a continuous unrealized loss position total	$ (24,396)	$ (13,535)
Obligations of U.S. government-sponsored enterprises [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	0	8
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 0	$ 69,681
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ 0	$ (798)
Number of securities in a continuous unrealized loss position for 12 months or longer | security	16	8
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 157,032	$ 87,923
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (4,467)	$ (3,077)
Number of individual name issuer trust preferred securities in a continuous unrealized loss position total | security	16	16
Fair value of securities in a continuous unrealized loss position total	$ 157,032	$ 157,604
Unrealized losses of securities in a continuous unrealized loss position total	$ (4,467)	$ (3,875)
Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	10	20
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 47,060	$ 128,965
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ (439)	$ (613)
Number of securities in a continuous unrealized loss position for 12 months or longer | security	51	22
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 438,701	$ 279,693
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (16,178)	$ (7,120)
Number of individual name issuer trust preferred securities in a continuous unrealized loss position total | security	61	42
Fair value of securities in a continuous unrealized loss position total	$ 485,761	$ 408,658
Unrealized losses of securities in a continuous unrealized loss position total	$ (16,617)	$ (7,733)
Individual name issuer trust preferred debt securities [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	0	0
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 0	$ 0
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ 0	$ 0
Number of securities in a continuous unrealized loss position for 12 months or longer | security	5	7
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 11,772	$ 16,984
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (1,535)	$ (1,122)
Number of individual name issuer trust preferred securities in a continuous unrealized loss position total | security	5	7
Fair value of securities in a continuous unrealized loss position total	$ 11,772	$ 16,984
Unrealized losses of securities in a continuous unrealized loss position total	$ (1,535)	$ (1,122)
Corporate bonds [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	3	3
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 1,198	$ 921
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ (9)	$ (5)
Number of securities in a continuous unrealized loss position for 12 months or longer | security	5	3
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 10,427	$ 10,980
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (1,768)	$ (800)
Number of individual name issuer trust preferred securities in a continuous unrealized loss position total | security	8	6
Fair value of securities in a continuous unrealized loss position total	$ 11,625	$ 11,901
Unrealized losses of securities in a continuous unrealized loss position total	$ (1,777)	$ (805)

Loans (Narrative) (Details)

Loans (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Net unamortized loan origination costs	$ 4,700	$ 3,800
Net unamortized premiums on purchased loans	703	878
Loans pledged as collateral	2,000,000	1,600,000
Residential loans in process of foreclosure	761	4,400
Nonaccrual loans	$ 8,600	$ 11,800

Loans (Narrative - Credit Quali

Loans (Narrative - Credit Quality Indicators) (Details) - rating	Dec. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Weighted Average Risk Rating, Commercial Loans	4.74	4.70

Loans (Summary of Loans) (Detai

Loans (Summary of Loans) (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[1]	$ 3,680,360	$ 3,374,071
Percent of total loans	[1]	100.00%	100.00%
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[2]	$ 1,392,408	$ 1,210,495
Percent of total loans	[2]	38.00%	36.00%
Commercial & Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[3]	$ 620,704	$ 612,334
Percent of total loans	[3]	17.00%	18.00%
Total Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 2,013,112	$ 1,822,829
Percent of total loans		55.00%	54.00%
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[4]	$ 1,360,387	$ 1,227,248
Percent of total loans	[4]	37.00%	36.00%
Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 280,626	$ 292,467
Percent of total loans		8.00%	9.00%
Other Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[5]	$ 26,235	$ 31,527
Percent of total loans	[5]	0.00%	1.00%
Total Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 306,861	$ 323,994
Percent of total loans		8.00%	10.00%
[1]	Includes net unamortized loan origination costs of $4.7 million and $3.8 million, respectively, at December 31, 2018 and 2017 and net unamortized premiums on purchased loans of $703 thousand and $878 thousand, respectively, at December 31, 2018 and 2017.
[2]	Consists of commercial mortgages primarily secured by income-producing property, as well as construction and development loans. Construction and development loans are made to businesses for land development or the on-site construction of industrial, commercial, or residential buildings.
[3]	Consists of loans to businesses and individuals, a substantial portion of which are fully or partially collateralized by real estate.
[4]	Consists of mortgage and homeowner construction loans secured by one- to four- family residential properties.
[5]	Consists of loans to individuals secured by general aviation aircraft and other personal installment loans.

Loans (Past Due Loans) (Details

Loans (Past Due Loans) (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		$ 13,622	$ 20,075
Current loans		3,666,738	3,353,996
Total loans	[1]	3,680,360	3,374,071
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		1,080	4,960
Current loans		1,391,328	1,205,535
Total loans	[2]	1,392,408	1,210,495
Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	4,076
Current loans		620,704	608,258
Total loans	[3]	620,704	612,334
Total Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		1,080	9,036
Current loans		2,012,032	1,813,793
Total loans		2,013,112	1,822,829
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		10,520	7,855
Current loans		1,349,867	1,219,393
Total loans	[4]	1,360,387	1,227,248
Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		1,989	3,141
Current loans		278,637	289,326
Total loans		280,626	292,467
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		33	43
Current loans		26,202	31,484
Total loans	[5]	26,235	31,527
Total Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		2,022	3,184
Current loans		304,839	320,810
Total loans		306,861	323,994
30-59
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		7,787	8,304
30-59 | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		155	6
30-59 | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	3,793
30-59 | Total Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		155	3,799
30-59 | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		6,318	1,678
30-59 | Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		1,281	2,798
30-59 | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		33	29
30-59 | Total Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		1,314	2,827
60-89
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		3,774	2,351
60-89 | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		925	0
60-89 | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	2
60-89 | Total Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		925	2
60-89 | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		2,693	2,274
60-89 | Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		156	75
60-89 | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	0
60-89 | Total Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		156	75
Over 90
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		2,061	9,420
Over 90 | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	4,954
Over 90 | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	281
Over 90 | Total Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	5,235
Over 90 | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		1,509	3,903
Over 90 | Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		552	268
Over 90 | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	14
Over 90 | Total Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		$ 552	$ 282
[1]	Includes net unamortized loan origination costs of $4.7 million and $3.8 million, respectively, at December 31, 2018 and 2017 and net unamortized premiums on purchased loans of $703 thousand and $878 thousand, respectively, at December 31, 2018 and 2017.
[2]	Consists of commercial mortgages primarily secured by income-producing property, as well as construction and development loans. Construction and development loans are made to businesses for land development or the on-site construction of industrial, commercial, or residential buildings.
[3]	Consists of loans to businesses and individuals, a substantial portion of which are fully or partially collateralized by real estate.
[4]	Consists of mortgage and homeowner construction loans secured by one- to four- family residential properties.
[5]	Consists of loans to individuals secured by general aviation aircraft and other personal installment loans.

Loans (Impaired Loans) (Details

Loans (Impaired Loans) (Details) - USD ($)		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Recorded Investment of Impaired Loans with No Related Allowance	[1]	$ 16,313,000	$ 14,626,000
Collateral dependent impaired loans	[1]	523,000	5,993,000
Total Recorded Investment of Impaired Loans	[1]	16,836,000	20,619,000
Unpaid Principal of Impaired Loans with No Related Allowance		16,713,000	14,908,000
Unpaid Principal of Impaired Loans with Related Allowance		570,000	10,995,000
Total Unpaid Principal of Impaired Loans		17,283,000	25,903,000
No Related Allowance on Impaired Loans		0	0
Related Allowance on Impaired Loans		127,000	1,129,000
Average Recorded Investment of Impaired Loans		17,349,000	30,269,000	$ 31,323,000
Interest Income Recognized on Impaired Loans		709,000	845,000	719,000
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment of Impaired Loans with No Related Allowance	[1]	925,000	0
Collateral dependent impaired loans	[1]	0	4,954,000
Unpaid Principal of Impaired Loans with No Related Allowance		926,000	0
Unpaid Principal of Impaired Loans with Related Allowance		0	9,910,000
No Related Allowance on Impaired Loans		0	0
Related Allowance on Impaired Loans		0	1,018,000
Average Recorded Investment of Impaired Loans		1,050,000	8,425,000	13,201,000
Interest Income Recognized on Impaired Loans		0	79,000	239,000
Commercial & Industrial [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment of Impaired Loans with No Related Allowance	[1]	4,681,000	4,986,000
Collateral dependent impaired loans	[1]	52,000	191,000
Unpaid Principal of Impaired Loans with No Related Allowance		4,732,000	5,081,000
Unpaid Principal of Impaired Loans with Related Allowance		73,000	212,000
No Related Allowance on Impaired Loans		0	0
Related Allowance on Impaired Loans		0	1,000
Average Recorded Investment of Impaired Loans		5,403,000	6,445,000	3,540,000
Interest Income Recognized on Impaired Loans		259,000	281,000	99,000
Total Commercial [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment of Impaired Loans with No Related Allowance	[1]	5,606,000	4,986,000
Collateral dependent impaired loans	[1]	52,000	5,145,000
Total Recorded Investment of Impaired Loans	[1]	5,658,000	10,131,000
Unpaid Principal of Impaired Loans with No Related Allowance		5,658,000	5,081,000
Unpaid Principal of Impaired Loans with Related Allowance		73,000	10,122,000
Total Unpaid Principal of Impaired Loans		5,731,000	15,203,000
No Related Allowance on Impaired Loans		0	0
Related Allowance on Impaired Loans		0	1,019,000
Average Recorded Investment of Impaired Loans		6,453,000	14,870,000	16,741,000
Interest Income Recognized on Impaired Loans		259,000	360,000	338,000
Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment of Impaired Loans with No Related Allowance	[1]	9,347,000	9,069,000
Collateral dependent impaired loans	[1]	364,000	715,000
Total Recorded Investment of Impaired Loans	[1]	9,711,000	9,784,000
Unpaid Principal of Impaired Loans with No Related Allowance		9,695,000	9,256,000
Unpaid Principal of Impaired Loans with Related Allowance		390,000	741,000
Total Unpaid Principal of Impaired Loans		10,085,000	9,997,000
No Related Allowance on Impaired Loans		0	0
Related Allowance on Impaired Loans		100,000	104,000
Average Recorded Investment of Impaired Loans		9,645,000	14,571,000	12,848,000
Interest Income Recognized on Impaired Loans		393,000	444,000	322,000
Home Equity [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment of Impaired Loans with No Related Allowance	[1]	1,360,000	557,000
Collateral dependent impaired loans	[1]	85,000	0
Unpaid Principal of Impaired Loans with No Related Allowance		1,360,000	557,000
Unpaid Principal of Impaired Loans with Related Allowance		85,000	0
No Related Allowance on Impaired Loans		0	0
Related Allowance on Impaired Loans		24,000	0
Average Recorded Investment of Impaired Loans		1,182,000	685,000	1,587,000
Interest Income Recognized on Impaired Loans		52,000	31,000	48,000
Other Consumer [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment of Impaired Loans with No Related Allowance	[1]	0	14,000
Collateral dependent impaired loans	[1]	22,000	133,000
Unpaid Principal of Impaired Loans with No Related Allowance		0	14,000
Unpaid Principal of Impaired Loans with Related Allowance		22,000	132,000
No Related Allowance on Impaired Loans		0	0
Related Allowance on Impaired Loans		3,000	6,000
Average Recorded Investment of Impaired Loans		69,000	143,000	147,000
Interest Income Recognized on Impaired Loans		5,000	10,000	11,000
Total Consumer [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment of Impaired Loans with No Related Allowance	[1]	1,360,000	571,000
Collateral dependent impaired loans	[1]	107,000	133,000
Total Recorded Investment of Impaired Loans	[1]	1,467,000	704,000
Unpaid Principal of Impaired Loans with No Related Allowance		1,360,000	571,000
Unpaid Principal of Impaired Loans with Related Allowance		107,000	132,000
Total Unpaid Principal of Impaired Loans		1,467,000	703,000
No Related Allowance on Impaired Loans		0	0
Related Allowance on Impaired Loans		27,000	6,000
Average Recorded Investment of Impaired Loans		1,251,000	828,000	1,734,000
Interest Income Recognized on Impaired Loans		$ 57,000	$ 41,000	$ 59,000
[1]	The recorded investment in impaired loans consists of unpaid principal balance, net of charge-offs, interest payments received applied to principal and unamortized deferred loan origination fees and costs. For accruing impaired loans (troubled debt restructurings for which management has concluded that the collectability of the loan is not in doubt), the recorded investment also includes accrued interest.

Loans (Nonaccrual Loans) (Detai

Loans (Nonaccrual Loans) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 11,707	$ 15,211
Accruing loans 90 days or more past due	0	0
Current Payment Status [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans current on payment	3,100	3,400
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	925	4,954
Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	0	283
Total Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	925	5,237
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	9,346	9,414
Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	1,436	544
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	0	16
Total Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 1,436	$ 560

Loans (Narrative - Troubled Deb

Loans (Narrative - Troubled Debt Restructurings) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)loan	Dec. 31, 2017USD ($)loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment	$ 5,600	$ 11,200
Specific reserves on troubled debt restructurings	$ 103	$ 1,100
Number of Loans Modified as a Troubled Debt Restructuring | loan	1	0
Post-Modification Recorded Investment	$ 608	$ 0
Pre-Modification Recorded Investment	$ 608	$ 0
Payment Default [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans Modified as a Troubled Debt Restructuring | loan	1	0
Recorded Investment on Modifications with Subsequent Default	$ 608	$ 0

Loans (Credit Quality Indicator

Loans (Credit Quality Indicators - Commercial) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Pass [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	$ 1,387,666	$ 1,205,381
Pass [Member] | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	559,019	592,749
Pass [Member] | Total Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	1,946,685	1,798,130
Special Mention [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	205	0
Special Mention [Member] | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	50,426	9,804
Special Mention [Member] | Total Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	50,631	9,804
Classified [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	4,537	5,114
Classified [Member] | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	11,259	9,781
Classified [Member] | Total Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality indicator	$ 15,796	$ 14,895

Loans (Credit Quality Indicat_2

Loans (Credit Quality Indicators - Residential, Consumer) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Current loans	$ 3,666,738	$ 3,353,996
Past due loans	13,622	20,075
Self-originated Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Current loans	1,238,402	1,091,291
Past due loans	9,079	6,413
Purchased Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Current loans	111,465	128,102
Past due loans	1,441	1,442
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Current loans	1,349,867	1,219,393
Past due loans	10,520	7,855
Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Current loans	278,637	289,326
Past due loans	1,989	3,141
Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Current loans	26,202	31,484
Past due loans	33	43
Total Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Current loans	304,839	320,810
Past due loans	$ 2,022	$ 3,184

Loans (Analysis of Loan Servici

Loans (Analysis of Loan Servicing Rights) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loan Servicing Rights [Roll Forward]
Beginning balance	$ 3,613	$ 3,493	$ 3,348
Loan servicing rights capitalized	905	1,104	1,412
Amortization	(867)	(984)	(1,267)
Decrease in impairment reserve			0
Ending balance	3,651	3,613	3,493
Valuation Allowance [Roll Forward]
Beginning balance	0	0	(1)
Loan servicing rights capitalized	0	0	0
Amortization	0	0	0
Decrease in impairment reserve			1
Ending balance	0	0	0
Total Loan Servicing Rights [Roll Forward]
Beginning Balance	3,613	3,493	3,347
Loan servicing rights capitalized	905	1,104	1,412
Amortization	(867)	(984)	(1,267)
Decrease in impairment reserve			1
Ending balance	$ 3,651	$ 3,613	$ 3,493

Loans (Estimated Aggregate Amor

Loans (Estimated Aggregate Amortization Expense) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Receivables [Abstract]
Amortization Expense, Next Twelve Months	$ 768
Amortization Expense, Year Two	606
Amortization Expense, Year Three	479
Amortization Expense, Year Four	378
Amortization Expense, Year Five	299
Amortization Expense, Thereafter	1,121
Total estimated amortization expense	$ 3,651	$ 3,613	$ 3,493	$ 3,348

Loans (Loans Serviced for Other

Loans (Loans Serviced for Others, by Type of Loan) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Balance of loans being serviced	$ 730,752	$ 676,850
Residential Mortgages [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Balance of loans being serviced	588,534	568,311
Commercial Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Balance of loans being serviced	$ 142,218	$ 108,539

Allowance for Loan Losses (Allo

Allowance for Loan Losses (Allowance for Loan Losses Rollforward Analysis) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance		$ 26,488	$ 26,004	$ 27,069
Charge-offs		(1,187)	(2,462)	(7,012)
Recoveries		221	346	297
Provision		1,550	2,600	5,650
Ending Balance		27,072	26,488	26,004
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	[1]	12,729	11,166	10,898
Charge-offs	[1]	(627)	(1,867)	(5,816)
Recoveries	[1]	25	82	56
Provision	[1]	3,254	3,348	6,028
Ending Balance	[1]	15,381	12,729	11,166
Commercial & Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance	[2]	5,580	6,992	8,202
Charge-offs	[2]	(10)	(336)	(759)
Recoveries	[2]	119	169	156
Provision	[2]	158	(1,245)	(607)
Ending Balance	[2]	5,847	5,580	6,992
Total Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance		18,309	18,158	19,100
Charge-offs		(637)	(2,203)	(6,575)
Recoveries		144	251	212
Provision		3,412	2,103	5,421
Ending Balance		21,228	18,309	18,158
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance		5,427	5,252	5,460
Charge-offs		(250)	(74)	(200)
Recoveries		21	39	11
Provision		(1,211)	210	(19)
Ending Balance		3,987	5,427	5,252
Home Equity [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance		2,412	1,889	1,915
Charge-offs		(193)	(79)	(147)
Recoveries		29	33	37
Provision		(645)	569	84
Ending Balance		1,603	2,412	1,889
Other Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance		340	705	594
Charge-offs		(107)	(106)	(90)
Recoveries		27	23	37
Provision		(6)	(282)	164
Ending Balance		254	340	705
Total Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning Balance		2,752	2,594	2,509
Charge-offs		(300)	(185)	(237)
Recoveries		56	56	74
Provision		(651)	287	248
Ending Balance		$ 1,857	$ 2,752	$ 2,594
[1]	Commercial real estate loans.
[2]	Commercial & industrial loans.

Allowance for Loan Losses (Al_2

Allowance for Loan Losses (Allowance for Loan Losses by Segment & Impairment Methodology) (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for impairment		$ 16,816	$ 20,598
Loans related allowance individually evaluated for impairment		127	1,129
Loans collectively evaluated for impairment		3,663,544	3,353,473
Loans related allowance collectively evaluated for impairment		26,945	25,359
Total loans	[1]	3,680,360	3,374,071
Allowance		27,072	26,488
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for impairment		925	4,954
Loans related allowance individually evaluated for impairment		0	1,018
Loans collectively evaluated for impairment		1,391,483	1,205,541
Loans related allowance collectively evaluated for impairment		15,381	11,711
Total loans	[2]	1,392,408	1,210,495
Commercial & Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for impairment		4,714	5,157
Loans related allowance individually evaluated for impairment		0	1
Loans collectively evaluated for impairment		615,990	607,177
Loans related allowance collectively evaluated for impairment		5,847	5,579
Total loans	[3]	620,704	612,334
Total Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for impairment		5,639	10,111
Loans related allowance individually evaluated for impairment		0	1,019
Loans collectively evaluated for impairment		2,007,473	1,812,718
Loans related allowance collectively evaluated for impairment		21,228	17,290
Total loans		2,013,112	1,822,829
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for impairment		9,710	9,783
Loans related allowance individually evaluated for impairment		100	104
Loans collectively evaluated for impairment		1,350,677	1,217,465
Loans related allowance collectively evaluated for impairment		3,887	5,323
Total loans	[4]	1,360,387	1,227,248
Home Equity [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for impairment		1,445	557
Loans related allowance individually evaluated for impairment		24	0
Loans collectively evaluated for impairment		279,182	291,910
Loans related allowance collectively evaluated for impairment		1,579	2,412
Total loans		280,626	292,467
Other Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for impairment		22	147
Loans related allowance individually evaluated for impairment		3	6
Loans collectively evaluated for impairment		26,212	31,380
Loans related allowance collectively evaluated for impairment		251	334
Total loans	[5]	26,235	31,527
Total Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for impairment		1,467	704
Loans related allowance individually evaluated for impairment		27	6
Loans collectively evaluated for impairment		305,394	323,290
Loans related allowance collectively evaluated for impairment		1,830	2,746
Total loans		$ 306,861	$ 323,994
[1]	Includes net unamortized loan origination costs of $4.7 million and $3.8 million, respectively, at December 31, 2018 and 2017 and net unamortized premiums on purchased loans of $703 thousand and $878 thousand, respectively, at December 31, 2018 and 2017.
[2]	Consists of commercial mortgages primarily secured by income-producing property, as well as construction and development loans. Construction and development loans are made to businesses for land development or the on-site construction of industrial, commercial, or residential buildings.
[3]	Consists of loans to businesses and individuals, a substantial portion of which are fully or partially collateralized by real estate.
[4]	Consists of mortgage and homeowner construction loans secured by one- to four- family residential properties.
[5]	Consists of loans to individuals secured by general aviation aircraft and other personal installment loans.

Premises and Equipment (Details

Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Land	$ 6,020	$ 6,020
Premises and Improvements	40,210	38,793
Furniture fixtures and equipment	24,798	26,240
Premises and equipment, gross	71,028	71,053
Less accumulated depreciation	42,023	42,720
Total premises and equipment, net	29,005	28,333
Depreciation expense	$ 3,300	$ 3,500	$ 3,700

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	$ 979	$ 1,035	$ 1,284
Weston Financial acquisition [Member] | Advisory Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible asset useful life (in years)	20 years
Halsey acquisition [Member] | Advisory Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible asset useful life (in years)	15 years

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets (Schedule of Goodwill) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Goodwill	$ 63,909	$ 63,909
Commercial Banking [Member]
Goodwill [Line Items]
Goodwill	22,591	22,591
Wealth Management Services [Member]
Goodwill [Line Items]
Goodwill	$ 41,318	$ 41,318

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets (Schedule of Components of Intangible Assets) (Details) - Advisory Contracts [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 20,803	$ 20,803
Accumulated amortization	12,641	11,663
Net amount	$ 8,162	$ 9,140

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets (Schedule of Amortization Annual Expense) (Details) $ in Thousands	Dec. 31, 2018USD ($)
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	$ 944
Finite-Lived Intangible Assets, Amortization Expense, Year Two	914
Finite-Lived Intangible Assets, Amortization Expense, Year Three	890
Finite-Lived Intangible Assets, Amortization Expense, Year Four	860
Finite-Lived Intangible Assets, Amortization Expense, Year Five	843
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	$ 3,711

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Adjustment to net deferred tax assets for enacted changes in federal tax law	$ 0	$ 6,170	$ 0
Unrecognized tax benefits	$ 0	$ 0

Income Taxes (Schedule of Compo

Income Taxes (Schedule of Components of Income Tax Expense) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current tax expense:
Federal									$ 15,460	$ 23,827	$ 19,444
State									2,863	2,201	2,061
Total current tax expense									18,323	26,028	21,505
Deferred tax expense (benefit):
Federal									63	5,717	796
State									(126)	(30)	72
Total deferred tax (benefit) expense									(63)	5,687	868
Total income tax expense	$ 4,523	$ 4,741	$ 4,742	$ 4,254	$ 13,163	$ 6,326	$ 6,505	$ 5,721	$ 18,260	$ 31,715	$ 22,373

Income Taxes (Schedule of Incom

Income Taxes (Schedule of Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Tax expense at Federal statutory rate									$ 18,205	$ 27,174	$ 24,099
Federal statutory rate									21.00%	35.00%	35.00%
(Decrease) increase in taxes resulting from:
Tax-exempt income, net									$ (809)	$ (1,313)	$ (1,599)
Tax-exempt income, net, rate									(0.90%)	(1.70%)	(2.30%)
Dividends received deduction									$ (45)	$ (55)	$ (58)
Dividends received deduction, rate									(0.10%)	(0.10%)	(0.10%)
BOLI									$ (461)	$ (757)	$ (930)
BOLI, rate									(0.50%)	(0.90%)	(1.30%)
Share-based compensation									$ (444)	$ (481)	$ 0
Share-based compensation, rate									(0.50%)	(0.60%)	0.00%
Federal tax credits									$ (364)	$ (364)	$ (364)
Federal tax credits, rate									(0.40%)	(0.50%)	(0.50%)
Change in fair value of contingent consideration									$ (39)	$ (225)	$ (314)
Change in fair value of contingent consideration, rate									(0.10%)	(0.30%)	(0.50%)
State income tax expense, net of federal income tax benefit									$ 2,162	$ 1,411	$ 1,387
State income tax expense, net of federal income tax benefit, rate									2.50%	1.80%	2.00%
Adjustment to net deferred tax assets for enacted changes in federal tax law									$ 0	$ 6,170	$ 0
Adjustment to net deferred tax asset for enacted changes in federal tax law, rate									0.00%	7.90%	0.00%
Other									$ 55	$ 155	$ 152
Other, rate									0.10%	0.20%	0.20%
Total income tax expense	$ 4,523	$ 4,741	$ 4,742	$ 4,254	$ 13,163	$ 6,326	$ 6,505	$ 5,721	$ 18,260	$ 31,715	$ 22,373
Effective tax rate									21.10%	40.80%	32.50%

Income Taxes (Schedule of Gross

Income Taxes (Schedule of Gross Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Allowance for loan losses	$ 6,362	$ 6,225
Defined benefit pension obligations	420	1,767
Deferred compensation	3,688	3,334
Deferred loan origination fees	1,410	1,325
Share-based compensation	1,124	1,240
Net unrealized losses on available for sale securities	5,149	2,314
Other	1,917	2,281
Deferred tax assets	20,070	18,486
Deferred tax liabilities:
Amortization of intangibles	(1,918)	(2,148)
Deferred loan origination costs	(3,897)	(3,550)
Loan servicing rights	(858)	(849)
Other	(1,120)	(1,200)
Deferred tax liabilities	(7,793)	(7,747)
Net deferred tax asset	$ 12,277	$ 10,739

Deposits (Narrative) (Details)

Deposits (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Time Certificates of Deposit [Abstract]
Time deposits greater than FDIC limit	$ 129.3	$ 75.1

Deposits (Summary of Deposits)

Deposits (Summary of Deposits) (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Deposits [Abstract]
Noninterest-bearing demand deposits		$ 603,216	$ 578,410
Interest-bearing demand deposits		178,733	82,728
NOW accounts		466,568	466,605
Money market accounts		646,878	731,345
Savings accounts		373,545	368,524
Time deposits	[1]	1,255,108	1,015,095
Total deposits		$ 3,524,048	$ 3,242,707
[1]	Includes wholesale brokered time deposits.

Deposits (Schedule of Time Cert

Deposits (Schedule of Time Certifcates of Deposit Maturities) (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Schedule Maturity Abstract]
Time Deposits Scheduled Maturity, Next Twelve Months		$ 688,862
Time Deposits Scheduled Maturity, Year Two		350,963
Time Deposits Scheduled Maturity, Year Three		76,248
Time Deposits Scheduled Maturity, Year Four		102,934
Time Deposits Scheduled Maturity, Year Five		35,872
Time Deposits Scheduled Maturity, Thereafter		229
Time deposits	[1]	$ 1,255,108	$ 1,015,095
Weighted Average Rate [Abstract]
Time Deposits Weighted Average Rate, Next Twelve Months		1.78%
Time Deposits Weighted Average Rate, Year Two		2.14%
Time Deposits Weighted Average Rate, Year Three		2.04%
Time Deposits Weighted Average Rate, Year Four		2.43%
Time Deposits Weighted Average Rate, Year Five		1.96%
Time Deposits Weighted Average Rate, Thereafter		1.14%
Total Time Deposits Weighted Average Rate		1.95%
[1]	Includes wholesale brokered time deposits.

Deposits (Schedule of Time Ce_2

Deposits (Schedule of Time Certificates of Deposit $100 Thousand or More Maturities) (Details) $ in Thousands	Dec. 31, 2018USD ($)
Deposits [Abstract]
Time Deposits $100,000 or More Maturing in Three Months or Less	$ 39,014
Time Deposits $100,000 or More Maturing in Three Months Through Six Months	30,839
Time Deposits $100,000 or More Maturing in Six Months Through Twelve Months	45,508
Time Deposits $100,000 or More Maturing After 12 Months	338,214
Time Deposits $100,000 or More Balance at Year End	$ 453,575

Borrowings (Narrative - Federal

Borrowings (Narrative - Federal Home Loan Bank Advances) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 950,722	$ 791,356
Federal Home Loan Bank of Boston [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank advances	950,722	791,356
Unused line of credit with Federal Home Loan Bank	40,000	40,000
Line of Credit Facility, Remaining Borrowing Capacity	$ 628,500	$ 449,900

Borrowings (Narrative - Junior

Borrowings (Narrative - Junior Subordinated Debentures) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Aug. 29, 2005
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Junior subordinated debentures	$ 22,681	$ 22,681
Trust Preferred Securities [Member] | Trust I Capital Securities [Member] | Private Placement [Member]
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Amount of capital securities issued			$ 8,300
Description of variable rate basis	three-month LIBOR
Basis spread on variable rate	1.45%
Trust Preferred Securities [Member] | Trust I Debentures [Member]
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Junior subordinated debentures			8,300
Description of variable rate basis	three-month LIBOR
Basis spread on variable rate	1.45%
Trust Preferred Securities [Member] | Trust II Capital Securities [Member] | Private Placement [Member]
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Amount of capital securities issued			14,400
Description of variable rate basis	three-month LIBOR
Basis spread on variable rate	1.45%
Trust Preferred Securities [Member] | Trust II Debentures [Member]
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Junior subordinated debentures			$ 14,400
Description of variable rate basis	three-month LIBOR
Basis spread on variable rate	1.45%

Borrowings (Federal Home Loan B

Borrowings (Federal Home Loan Bank Advances Maturity Schedule) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Federal Home Loan Bank, Advances, Fiscal Year Maturity [Abstract]
Federal Home Loan Bank advances	$ 950,722	$ 791,356
Federal Home Loan Bank of Boston [Member]
Federal Home Loan Bank, Advances, Fiscal Year Maturity [Abstract]
Scheduled Maturity, Next 12 months	767,258
Scheduled Maturity, Year Two	67,033
Scheduled Maturity, Year Three	46,222
Scheduled Maturity, Year Four	55,447
Scheduled Maturity, Year Five	9,428
Scheduled Maturity, Thereafter	5,334
Federal Home Loan Bank advances	$ 950,722	$ 791,356
Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate of Amounts Due [Abstract]
Weighted Average Rate, Next 12 months	2.49%
Weighted Average Rate, Year Two	2.00%
Weighted Average Rate, Year Three	2.65%
Weighted Average Rate, Year Four	3.65%
Weighted Average Rate, Year Five	4.01%
Weighted Average Rate, Thereafter	5.06%
Weighted Average Rate, Total	2.56%

Borrowings (Certain Information

Borrowings (Certain Information of Federal Home Loan Bank of Boston Advances) (Details) - Federal Home Loan Bank of Boston [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Average amount outstanding during the period	$ 484,090	$ 351,692	$ 275,533
Amount outstanding at end of period	630,000	367,500	352,500
Highest month end balance during period	$ 630,000	$ 417,500	$ 367,500
Weighted-average interest rate at end of period	2.67%	1.57%	0.79%
Weighted-average interest rate during the period	2.23%	1.20%	0.73%

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2006	Dec. 31, 2018	Dec. 31, 2017
Equity Additional Information [Line Items]
Trust preferred securities included in Tier 1 Capital		$ 22,000	$ 21,998
Dividends:
Amount of additional dividends the bank could have declared		$ 233,000
Reserved Shares:
Reserved shares available for grant		1,804,163
2006 Stock Repurchase Plan [Member]
Stock Repurchase Program:
Authorized amount (in shares)	400,000
Authorized amount as a percentage of total common stock	3.00%
Cumulative amount of shares purchased		185,400
Shares repurchased, value		$ 4,800

Shareholders' Equity (Regulator

Shareholders' Equity (Regulatory Captial Requirements) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Parent Company [Member]
Total Capital (to Risk-Weighted Assets):
Total Capital	$ 455,699	$ 416,038
Total Capital to Risk-Weighted Assets	12.56%	12.45%
Total Capital for Capital Adequacy Purposes	$ 290,146	$ 267,365
Total Capital for Capital Adequacy Purposes to Risk-Weighted Assets	8.00%	8.00%
Tier 1 Capital (to Risk-Weighted Assets):
Tier 1 Capital	$ 428,338	$ 389,289
Tier 1 Capital to Risk Weighted-Assets	11.81%	11.65%
Tier 1 Capital Required For Capital Adequacy Purposes	$ 217,609	$ 200,524
Tier 1 Capital Required for Capital Adequacy Purposes to Risk Weighted-Assets	6.00%	6.00%
Common Equity Tier 1 Capital [Abstract]
Common Equity Tier 1 Capital	$ 406,340	$ 367,291
Common Equity Tier 1 Capital to Risk Weighted Assets	11.20%	10.99%
Common Equity Tier 1 Required for Capital Adequacy	$ 163,207	$ 150,383
Common Equity Tier 1 Capital for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Tier 1 Capital (to Average Assets):
Tier 1 Leverage Capital	$ 428,338	$ 389,289
Tier 1 Leverage Capital to Average Assets	8.89%	8.79%
Tier 1 Leverage Capital Required for Capital Adequacy Purposes	$ 192,690	$ 177,089
Tier 1 Leverage Capital Required for Capital Adequacy Purposes to Average Assets	4.00%	4.00%
Bank [Member]
Total Capital (to Risk-Weighted Assets):
Total Capital	$ 453,033	$ 413,593
Total Capital to Risk-Weighted Assets	12.49%	12.38%
Total Capital for Capital Adequacy Purposes	$ 290,128	$ 267,338
Total Capital for Capital Adequacy Purposes to Risk-Weighted Assets	8.00%	8.00%
Total Capital To Be Well Capitalized	$ 362,660	$ 334,172
Total Capital To Be Well Capitalized to Risk Weighted-Assets	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets):
Tier 1 Capital	$ 425,672	$ 386,844
Tier 1 Capital to Risk Weighted-Assets	11.74%	11.58%
Tier 1 Capital Required For Capital Adequacy Purposes	$ 217,596	$ 200,503
Tier 1 Capital Required for Capital Adequacy Purposes to Risk Weighted-Assets	6.00%	6.00%
Tier 1 Capital Required To Be Well Capitalized	$ 290,128	$ 267,338
Tier 1 Capital Required To Be Well Capitalized to Risk Weighted-Assets	8.00%	8.00%
Common Equity Tier 1 Capital [Abstract]
Common Equity Tier 1 Capital	$ 425,672	$ 386,844
Common Equity Tier 1 Capital to Risk Weighted Assets	11.74%	11.58%
Common Equity Tier 1 Required for Capital Adequacy	$ 163,197	$ 150,378
Common Equity Tier 1 Capital for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Common Equity Tier 1 Capital Required to be Well Capitalized	$ 235,729	$ 217,212
Common Equity Tier 1 Capital Required to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
Tier 1 Capital (to Average Assets):
Tier 1 Leverage Capital	$ 425,672	$ 386,844
Tier 1 Leverage Capital to Average Assets	8.84%	8.74%
Tier 1 Leverage Capital Required for Capital Adequacy Purposes	$ 192,652	$ 177,048
Tier 1 Leverage Capital Required for Capital Adequacy Purposes to Average Assets	4.00%	4.00%
Tier 1 Leverage Capital Required To Be Well Capitalized	$ 240,815	$ 221,310
Tier 1 Leverage Capital Required To Be Well Capitalized to Average Assets	5.00%	5.00%

Derivative Financial Instrume_3

Derivative Financial Instruments (Narrative) (Details) $ in Thousands	Dec. 31, 2018USD ($)derivative_instrument	Dec. 31, 2017USD ($)derivative_instrument
Interest rate swaps [Member]
Derivatives, Fair Value [Line Items]
Notional amount	$ 60,000	$ 60,000
Interest rate swaps with customers [Member]
Derivatives, Fair Value [Line Items]
Notional amount	648,050	545,049
Mirror swaps with counterparties [Member]
Derivatives, Fair Value [Line Items]
Notional amount	648,050	545,049
Risk participation-in agreement [Member]
Derivatives, Fair Value [Line Items]
Notional amount	46,510	34,052
Foreign exchange contracts [Member]
Derivatives, Fair Value [Line Items]
Notional amount	2,784	3,005
Interest rate lock commitments [Member]
Derivatives, Fair Value [Line Items]
Notional amount	30,766	45,139
Commitments to sell mortgage loans [Member]
Derivatives, Fair Value [Line Items]
Notional amount	$ 61,993	71,539
Designated as Hedging Instrument [Member] | Interest rate caps [Member]
Derivatives, Fair Value [Line Items]
Number of derivative instruments held | derivative_instrument	2
Notional amount	$ 22,700	$ 22,700
Interest rate cap strike	4.50%
Designated as Hedging Instrument [Member] | Interest rate swaps [Member]
Derivatives, Fair Value [Line Items]
Number of derivative instruments held | derivative_instrument	2	2
Notional amount	$ 60,000	$ 60,000
Designated as Hedging Instrument [Member] | Interest rate floors [Member]
Derivatives, Fair Value [Line Items]
Number of derivative instruments held | derivative_instrument	3	3
Notional amount	$ 300,000	$ 300,000
Interest rate floor strike	1.00%
Not Designated as Hedging Instrument [Member] | Interest rate swaps with customers [Member]
Derivatives, Fair Value [Line Items]
Notional amount	$ 648,000	545,000
Not Designated as Hedging Instrument [Member] | Risk participation-out agreement [Member]
Derivatives, Fair Value [Line Items]
Notional amount	57,300	52,400
Not Designated as Hedging Instrument [Member] | Risk participation-in agreement [Member]
Derivatives, Fair Value [Line Items]
Notional amount	46,500	34,100
Not Designated as Hedging Instrument [Member] | Foreign exchange contracts [Member]
Derivatives, Fair Value [Line Items]
Notional amount	$ 2,784	$ 3,005

Derivative Financial Instrume_4

Derivative Financial Instruments (Fair Value of Derivatives by Balance Sheet Location) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative assets	$ 3,966	$ 2,759
Derivative liabilities	3,202	3,047
Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	3,966	2,759
Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	3,202	3,047
Interest rate caps [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Interest rate cash flow hedge asset at fair value	20	25
Interest rate caps [Member] | Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Interest rate cash flow hedge liability at fair value	0	0
Interest rate swaps [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Interest rate cash flow hedge asset at fair value	903	213
Interest rate swaps [Member] | Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Interest rate cash flow hedge liability at fair value	0	14
Interest rate floors [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Interest rate cash flow hedge asset at fair value	37	110
Interest rate floors [Member] | Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Interest rate cash flow hedge liability at fair value	0	0
Interest rate swaps with customers [Member] | Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset not designated as hedging instruments	0	268
Interest rate swaps with customers [Member] | Not Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability not designated as hedging instruments	2,379	1,295
Mirror swaps with counterparties [Member] | Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset not designated as hedging instruments	2,200	1,152
Mirror swaps with counterparties [Member] | Not Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability not designated as hedging instruments	0	268
Risk participation agreements [Member] | Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset not designated as hedging instruments	0	0
Risk participation agreements [Member] | Not Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability not designated as hedging instruments	0	0
Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset not designated as hedging instruments	0	0
Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability not designated as hedging instruments	7	26
Interest rate lock commitments [Member] | Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset not designated as hedging instruments	806	965
Interest rate lock commitments [Member] | Not Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability not designated as hedging instruments	0	20
Commitments to sell mortgage loans [Member] | Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset not designated as hedging instruments	0	26
Commitments to sell mortgage loans [Member] | Not Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability not designated as hedging instruments	$ 816	$ 1,424

Derivative Financial Instrume_5

Derivative Financial Instruments (Derivatives in Cash Flow Hedging Relationships, Effect in Statements of Changes in Shareholders' Equity and Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Net change in fair value of cash flow hedges	$ 619	$ (52)	$ (257)
Other Comprehensive Income (Loss) [Member] | Interest rate caps [Member] | Cash Flow Hedge [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net change in fair value of cash flow hedges	30	(64)	(33)
Other Comprehensive Income (Loss) [Member] | Interest rate swaps [Member] | Cash Flow Hedge [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net change in fair value of cash flow hedges	515	358	(224)
Other Comprehensive Income (Loss) [Member] | Interest rate floors [Member] | Cash Flow Hedge [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net change in fair value of cash flow hedges	$ 74	$ (346)	$ 0

Derivative Financial Instrume_6

Derivative Financial Instruments (Derivatives not Designated as Hedging Instruments, Effect in Statements of Income) (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	$ 3,319	$ 2,786	$ 4,010
Interest rate swaps with customers [Member] | Loan related derivative income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	(290)	2,243	(598)
Mirror swaps with counterparties [Member] | Loan related derivative income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	2,709	1,198	3,854
Risk participation agreements [Member] | Loan related derivative income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	(27)	(233)	(13)
Foreign exchange contracts [Member] | Loan related derivative income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	69	6	0
Interest rate lock commitments [Member] | Mortgage banking revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	(139)	(100)	(175)
Commitments to sell mortgage loans [Member] | Mortgage banking revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	$ 997	$ (328)	$ 942

Balance Sheet Offsetting (Detai

Balance Sheet Offsetting (Details) - USD ($)		Dec. 31, 2018	Dec. 31, 2017
Derivative Assets [Member]
Gross derivative assets		$ 13,892,000	$ 7,006,000
Less amounts offset in Consolidated Balance Sheets, derivative assets		10,732,000	5,238,000
Net amounts presented in Consolidated Balance Sheets, derivative assets		3,160,000	1,768,000
Less collateral pledged, derivatives assets	[1]	0	0
Net amounts		3,160,000	1,768,000
Derivative Liabilities [Member]
Gross derivative liabilities		13,118,000	6,841,000
Less amounts offset in Consolidated Balance Sheets, derivative liabilities		10,732,000	5,238,000
Net amounts presented in Consolidated Balance Sheets, derivative liabilities		2,386,000	1,603,000
Less collateral pledged, derivative liabilities	[1]	1,460,000	1,039,000
Net amounts		926,000	564,000
Other assets [Member] | Interest rate caps [Member]
Gross derivative assets		20,000	25,000
Other assets [Member] | Interest rate swaps [Member]
Gross derivative assets		903,000	213,000
Other assets [Member] | Interest rate floors [Member]
Gross derivative assets		37,000	110,000
Other liabilities [Member] | Interest rate caps [Member]
Gross derivative liabilities		0	0
Other liabilities [Member] | Interest rate swaps [Member]
Gross derivative liabilities		0	14,000
Other liabilities [Member] | Interest rate floors [Member]
Gross derivative liabilities		0	0
Other liabilities [Member] | Interest rate swaps with customers [Member]
Gross derivative assets		5,340,000	2,857,000
Gross derivative liabilities		7,719,000	3,884,000
Other liabilities [Member] | Mirror swaps with counterparties [Member]
Gross derivative assets		7,592,000	3,801,000
Gross derivative liabilities		5,392,000	2,917,000
Other liabilities [Member] | Foreign exchange contracts [Member]
Gross derivative assets		0	0
Gross derivative liabilities		$ 7,000	$ 26,000
[1]	Collateral pledged to derivative counterparties in the form of cash. Washington Trust may need to post additional collateral in the future in proportion to potential increases in unrealized loss positions.

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands	Aug. 01, 2015	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payment of contingent consideration liability		$ (1,217)	$ 0
Change in fair value of contingent consideration		(187)	(643)	$ (898)
Contingent consideration liability		0	1,404	$ 2,047
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability			1,404
Contingent Consideration [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Earn-out period post acquisition	5 years
Mortgage Loans Held for Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Change in fair value of mortgage loans held for sale under fair value option		(45)	503
Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Allowance for loan loss on collateral dependent impaired loans		$ 24	$ 690

Fair Value Measurements (Mortga

Fair Value Measurements (Mortgage Loans Held For Sale, Fair Value Option) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Aggregate fair value	$ 20,996	$ 26,943
Aggregate principal balance	20,498	26,400
Difference between fair value and principal balance	$ 498	$ 543

Fair Value Measurements (Assets

Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	$ 927,810	$ 780,954
Mortgage loans held for sale, fair value	20,996	26,943
Derivative assets	3,966	2,759
Derivative liabilities	3,202	3,047
Contingent consideration liability	0	1,404	$ 2,047
Obligations of U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	242,683	157,604
Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	660,793	590,882
Obligations of states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	937	2,359
Individual name issuer trust preferred debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	11,772	16,984
Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	11,625	13,125
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Contingent consideration liability		0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	3,966	2,759
Derivative liabilities	3,202	3,047
Contingent consideration liability		0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Contingent consideration liability		1,404
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale, fair value	20,996	26,943
Total assets at fair value on a recurring basis	952,772	810,656
Total liabilities at fair value on a recurring basis	3,202	4,451
Recurring [Member] | Obligations of U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	242,683	157,604
Recurring [Member] | Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	660,793	590,882
Recurring [Member] | Obligations of states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	937	2,359
Recurring [Member] | Individual name issuer trust preferred debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	11,772	16,984
Recurring [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	11,625	13,125
Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale, fair value	0	0
Total assets at fair value on a recurring basis	0	0
Total liabilities at fair value on a recurring basis	0	0
Recurring [Member] | Level 1 [Member] | Obligations of U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring [Member] | Level 1 [Member] | Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring [Member] | Level 1 [Member] | Obligations of states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring [Member] | Level 1 [Member] | Individual name issuer trust preferred debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring [Member] | Level 1 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale, fair value	20,996	26,943
Total assets at fair value on a recurring basis	952,772	810,656
Total liabilities at fair value on a recurring basis	3,202	3,047
Recurring [Member] | Level 2 [Member] | Obligations of U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	242,683	157,604
Recurring [Member] | Level 2 [Member] | Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	660,793	590,882
Recurring [Member] | Level 2 [Member] | Obligations of states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	937	2,359
Recurring [Member] | Level 2 [Member] | Individual name issuer trust preferred debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	11,772	16,984
Recurring [Member] | Level 2 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	11,625	13,125
Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale, fair value	0	0
Total assets at fair value on a recurring basis	0	0
Total liabilities at fair value on a recurring basis	0	1,404
Recurring [Member] | Level 3 [Member] | Obligations of U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring [Member] | Level 3 [Member] | Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring [Member] | Level 3 [Member] | Obligations of states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring [Member] | Level 3 [Member] | Individual name issuer trust preferred debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	0	0
Recurring [Member] | Level 3 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	$ 0	$ 0

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Measurements (Change in contingent consideration) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 1,404	$ 2,047
Change in fair value of contingent consideration liability	(187)	(643)	$ (898)
Payments	(1,217)	0
Ending Balance	$ 0	$ 1,404	$ 2,047

Fair Value Measurements (Asse_2

Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis) (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans	[1]	$ 523	$ 5,993
Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans		883	1,425
Property acquired through foreclosure or repossession		2,142	131
Total assets at fair value on a recurring basis		3,025	1,556
Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans		0	0
Property acquired through foreclosure or repossession		0	0
Total assets at fair value on a recurring basis		0	0
Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans		0	0
Property acquired through foreclosure or repossession		0	0
Total assets at fair value on a recurring basis		0	0
Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans		883	1,425
Property acquired through foreclosure or repossession		2,142	131
Total assets at fair value on a recurring basis		$ 3,025	$ 1,556
[1]	The recorded investment in impaired loans consists of unpaid principal balance, net of charge-offs, interest payments received applied to principal and unamortized deferred loan origination fees and costs. For accruing impaired loans (troubled debt restructurings for which management has concluded that the collectability of the loan is not in doubt), the recorded investment also includes accrued interest.

Fair Value Measurements (Qualit

Fair Value Measurements (Qualitative Information About Level 3 Assets Measured at Fair Value on a Nonrecurring Basis) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Fair Value Inputs Assets Qualitative Information [Line Items]
Collateral dependent impaired loans	[1]	$ 523	$ 5,993
Nonrecurring [Member]
Fair Value Inputs Assets Qualitative Information [Line Items]
Collateral dependent impaired loans		883	1,425
Property acquired through foreclosure or repossession		2,142	131
Nonrecurring [Member] | Level 3 [Member]
Fair Value Inputs Assets Qualitative Information [Line Items]
Collateral dependent impaired loans		883	1,425
Property acquired through foreclosure or repossession		$ 2,142	$ 131
Collateral Dependent Impaired Loans [Member] | Nonrecurring [Member] | Level 3 [Member] | Appraisals Of Collateral [Member] | Minimum [Member]
Fair Value Inputs Assets Qualitative Information [Line Items]
Discount for costs to sell		0.00%	0.00%
Appraisal adjustments	[2]	0.00%
Collateral Dependent Impaired Loans [Member] | Nonrecurring [Member] | Level 3 [Member] | Appraisals Of Collateral [Member] | Maximum [Member]
Fair Value Inputs Assets Qualitative Information [Line Items]
Discount for costs to sell		10.00%	15.00%
Appraisal adjustments	[2]	100.00%
Collateral Dependent Impaired Loans [Member] | Nonrecurring [Member] | Level 3 [Member] | Appraisals Of Collateral [Member] | Weighted Average [Member]
Fair Value Inputs Assets Qualitative Information [Line Items]
Discount for costs to sell		10.00%	15.00%
Appraisal adjustments	[2]	2.00%
Property Acquired Through Foreclosure Or Repossession [Member] | Nonrecurring [Member] | Level 3 [Member] | Appraisals Of Collateral [Member] | Minimum [Member]
Fair Value Inputs Assets Qualitative Information [Line Items]
Discount for costs to sell		13.00%	10.00%
Appraisal adjustments	[2]	12.00%	12.00%
Property Acquired Through Foreclosure Or Repossession [Member] | Nonrecurring [Member] | Level 3 [Member] | Appraisals Of Collateral [Member] | Maximum [Member]
Fair Value Inputs Assets Qualitative Information [Line Items]
Discount for costs to sell		13.00%	10.00%
Appraisal adjustments	[2]	28.00%	17.00%
Property Acquired Through Foreclosure Or Repossession [Member] | Nonrecurring [Member] | Level 3 [Member] | Appraisals Of Collateral [Member] | Weighted Average [Member]
Fair Value Inputs Assets Qualitative Information [Line Items]
Discount for costs to sell		13.00%	10.00%
Appraisal adjustments	[2]	20.00%	15.00%
[1]	The recorded investment in impaired loans consists of unpaid principal balance, net of charge-offs, interest payments received applied to principal and unamortized deferred loan origination fees and costs. For accruing impaired loans (troubled debt restructurings for which management has concluded that the collectability of the loan is not in doubt), the recorded investment also includes accrued interest.
[2]	Management may adjust appraisal values to reflect market value declines or other discounts resulting from its knowledge of the property.

Fair Value Measurements (Carryi

Fair Value Measurements (Carrying Amounts and Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held to maturity securities		$ 10,415	$ 12,541
Loans, net of allowance of loan losses		3,653,288	3,347,583
Time deposits	[1]	1,255,108	1,015,095
FHLB advances		950,722	791,356
Junior subordinated debentures		22,681	22,681
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held to maturity securities		10,415	12,541
Loans, net of allowance of loan losses		3,653,288	3,347,583
Time deposits		1,255,108	1,015,095
FHLB advances		950,722	791,356
Junior subordinated debentures		22,681	22,681
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held to maturity securities		10,316	12,721
Loans, net of allowance of loan losses		3,598,025	3,369,932
Time deposits		1,269,433	1,018,396
FHLB advances		950,691	792,887
Junior subordinated debentures		19,226	18,559
Estimate of Fair Value Measurement [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held to maturity securities		0	0
Loans, net of allowance of loan losses		0	0
Time deposits		0	0
FHLB advances		0	0
Junior subordinated debentures		0	0
Estimate of Fair Value Measurement [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held to maturity securities		10,316	12,721
Loans, net of allowance of loan losses		0	0
Time deposits		1,269,433	1,018,396
FHLB advances		950,691	792,887
Junior subordinated debentures		19,226	18,559
Estimate of Fair Value Measurement [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held to maturity securities		0	0
Loans, net of allowance of loan losses		3,598,025	3,369,932
Time deposits		0	0
FHLB advances		0	0
Junior subordinated debentures		$ 0	$ 0
[1]	Includes wholesale brokered time deposits.

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Revenue from Contract with Customer [Abstract]
Receivables	$ 4,800	$ 5,700
Contract cost assets	$ 458

Revenue from Contracts with C_4

Revenue from Contracts with Customers (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net interest income	$ 33,878	$ 33,449	$ 33,111	$ 31,852	$ 30,889	$ 30,059	$ 29,904	$ 28,679	$ 132,290	$ 119,531	$ 110,478
Asset-based wealth management revenues									37,343	38,125	36,139
Transaction-based wealth management revenues									998	1,221	1,430
Total wealth management revenues									38,341	39,346	37,569
Mortgage banking revenues									10,381	11,392	13,183
Service charges on deposit accounts									3,628	3,672	3,702
Card interchange fees									3,768	3,502	3,385
Income from bank-owned life insurance									2,196	2,161	2,659
Loan related derivative income									2,461	3,214	3,243
Other income									1,339	1,522	1,388
Total noninterest income	$ 15,163	$ 15,215	$ 15,993	$ 15,743	$ 16,210	$ 17,283	$ 16,806	$ 14,510	62,114	64,809	65,129
Total revenues									194,404	184,340	175,607
Revenue from Contract with Customer [Member]
Net interest income									0	0	0
Asset-based wealth management revenues									37,343	38,125	36,139
Transaction-based wealth management revenues									998	1,221	1,430
Total wealth management revenues									38,341	39,346	37,569
Mortgage banking revenues									0	0	0
Service charges on deposit accounts									3,628	3,672	3,702
Card interchange fees									3,768	3,502	3,385
Income from bank-owned life insurance									0	0	0
Loan related derivative income									0	0	0
Other income									1,329	1,469	1,388
Total noninterest income									47,066	47,989	46,044
Total revenues									$ 47,066	$ 47,989	$ 46,044

Revenue from Contract with Cust

Revenue from Contract with Customers (Disaggregation by Timing of Revenue Recognition) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Wealth management revenues	$ 38,341	$ 39,346	$ 37,569
Card interchange fees	3,768	3,502	3,385
Service charges on deposit accounts	3,628	3,672	3,702
Other income	1,339	1,522	1,388
Total revenues from contracts in scope of Topic 606	194,404	184,340	175,607
Revenue from Contract with Customer [Member]
Wealth management revenues	38,341	39,346	37,569
Card interchange fees	3,768	3,502	3,385
Service charges on deposit accounts	3,628	3,672	3,702
Other income	1,329	1,469	1,388
Total revenues from contracts in scope of Topic 606	47,066	47,989	46,044
Revenue from Contract with Customer [Member] | Transferred at Point in Time [Member]
Card interchange fees	3,768	3,502	3,385
Service charges on deposit accounts	2,802	2,899	2,914
Other income	958	1,122	1,062
Revenue from Contract with Customer [Member] | Transferred over Time [Member]
Wealth management revenues	38,341	39,346	37,569
Service charges on deposit accounts	826	773	788
Other income	$ 371	$ 347	$ 326

Employee Benefits (Narrative) (

Employee Benefits (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended			120 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 30, 2023
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution amounts	$ 2,500	$ 2,300	$ 2,300
Other incentive-based compensation expense	16,100	16,900	$ 16,000
Deferred compensation plan, accrued liability	$ 15,700	14,200
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution	3.00%
Qualified Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded (unfunded) status at end of period	$ 12,800	6,641
Accumulated benefit obligation	67,400	72,900
Estimated amortization of prior service cost (credit) from accumulated other comprehensive loss into net period benefit cost, next year	(16)
Estimated amortization of (gain) loss from accumulated other comprehensive loss into net period benefit cost, next year	$ 792
Fair value of equity securities, maximum percentage held by a single issuer	10.00%
Non-Qualified Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded (unfunded) status at end of period	$ (14,626)	(15,203)
Available-for-sale securities and other short-term investments, rabbi trusts	14,600	13,300
Accumulated benefit obligation	13,200	$ 14,000
Estimated amortization of prior service cost (credit) from accumulated other comprehensive loss into net period benefit cost, next year	0
Estimated amortization of (gain) loss from accumulated other comprehensive loss into net period benefit cost, next year	408
Estimated future employer contributions in next fiscal year	$ 907
Non-elective Employer Contribution [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution	4.00%
Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Transition Period Pension Plan Amendment				10 years

Employee Benefits (Schedule of

Employee Benefits (Schedule of Net Funded (Unfunded) Status) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Qualified Pension Plan [Member]
Change in Benefit Obligation:
Benefit obligation at beginning of period		$ 80,723	$ 72,951
Service cost	[1]	2,244	2,149	$ 2,148
Interest cost	[2]	2,715	2,673	2,576
Actuarial (gain) loss		(7,830)	7,017
Benefits paid		(4,344)	(3,936)
Administrative expenses		(128)	(131)
Benefit obligation at end of period		73,380	80,723	72,951
Change in Plan Assets:
Fair value of plan assets at beginning of period		87,364	75,787
Actual return on plan assets		288	12,644
Employer contributions		3,000	3,000
Benefits paid		(4,344)	(3,936)
Administrative expenses		(128)	(131)
Fair value of plan assets at end of period		86,180	87,364	75,787
Funded (unfunded) status at end of period		12,800	6,641
Non-Qualified Retirement Plans [Member]
Change in Benefit Obligation:
Benefit obligation at beginning of period		15,203	13,154
Service cost	[1]	108	129	122
Interest cost	[2]	475	428	432
Actuarial (gain) loss		(252)	2,275
Benefits paid		(908)	(783)
Administrative expenses		0	0
Benefit obligation at end of period		14,626	15,203	13,154
Change in Plan Assets:
Fair value of plan assets at beginning of period		0	0
Actual return on plan assets		0	0
Employer contributions		908	783
Benefits paid		(908)	(783)
Administrative expenses		0	0
Fair value of plan assets at end of period		0	0	$ 0
Funded (unfunded) status at end of period		$ (14,626)	$ (15,203)
[1]	Included in salaries and employee benefits expense in the Consolidated Statements of Income.
[2]	Included in other expenses in the Consolidated Statements of Income.

Employee Benefits (Components o

Employee Benefits (Components of Accumulated Other Comprehensive Income(Loss)) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Qualified Pension Plan [Member]
Components of Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Net actuarial loss	$ 9,453	$ 13,795
Prior service credit	(16)	(39)
Total pre-tax amounts recognized in accumulated other comprehensive income	9,437	13,756
Non-Qualified Retirement Plans [Member]
Components of Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Net actuarial loss	5,785	6,448
Prior service credit	0	(1)
Total pre-tax amounts recognized in accumulated other comprehensive income	$ 5,785	$ 6,447

Employee Benefits (Components_2

Employee Benefits (Components of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss) (on a pre-tax basis):
Net (gain) loss		$ (3,098)	$ 1,591	$ 4,106
Prior service cost	[1]	(18)	(15)	(15)
Recognized in other comprehensive (loss) income		4,981	(154)	(3,055)
Qualified Pension Plan [Member]
Net Periodic Benefit Cost:
Service cost	[2]	2,244	2,149	2,148
Interest cost	[3]	2,715	2,673	2,576
Expected return on plan assets	[3]	(5,272)	(4,942)	(4,633)
Amortization of prior service credit	[3]	(23)	(23)	(23)
Recognized net actuarial loss	[3]	1,496	1,114	828
Net periodic benefit cost		1,160	971	896
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss) (on a pre-tax basis):
Net (gain) loss		(4,342)	(1,798)	2,904
Prior service cost		23	23	23
Recognized in other comprehensive (loss) income		(4,319)	(1,775)	2,927
Total recognized in net periodic benefit cost and other comprehensive income (loss)		(3,159)	(804)	3,823
Non-Qualified Retirement Plans [Member]
Net Periodic Benefit Cost:
Service cost	[2]	108	129	122
Interest cost	[3]	475	428	432
Expected return on plan assets	[3]	0	0	0
Amortization of prior service credit	[3]	(1)	(1)	(1)
Recognized net actuarial loss	[3]	411	347	247
Net periodic benefit cost		993	903	800
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss) (on a pre-tax basis):
Net (gain) loss		(663)	1,928	127
Prior service cost		1	1	1
Recognized in other comprehensive (loss) income		(662)	1,929	128
Total recognized in net periodic benefit cost and other comprehensive income (loss)		$ 331	$ 2,832	$ 928
[1]	The pre-tax amounts are included in other expenses in the Consolidated Statements of Income.
[2]	Included in salaries and employee benefits expense in the Consolidated Statements of Income.
[3]	Included in other expenses in the Consolidated Statements of Income.

Employee Benefits (Weighted-Ave

Employee Benefits (Weighted-Average Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Qualified Pension Plan [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate	4.38%	3.69%
Rate of compensation increase	3.75%	3.75%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Equivalent single discount rate for benefit obligations	3.69%	4.18%	4.48%
Equivalent single discount rate for service cost	3.76%	4.29%	4.63%
Equivalent single discount rate for interest cost	3.42%	3.73%	3.88%
Expected long-term return on plan assets	6.75%	6.75%	6.75%
Rate of compensation increase	3.75%	3.75%	3.75%
Non-Qualified Retirement Plans [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate	4.30%	3.60%
Rate of compensation increase	3.75%	3.75%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Equivalent single discount rate for benefit obligations	3.58%	3.96%	4.20%
Equivalent single discount rate for service cost	3.79%	4.25%	4.59%
Equivalent single discount rate for interest cost	3.22%	3.36%	3.44%
Rate of compensation increase	3.75%	3.75%	3.75%

Employee Benefits (Schedule o_2

Employee Benefits (Schedule of Fair Value of Qualified Pension Plan Assets) (Details) - Qualified Pension Plan [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 86,180	$ 87,364	$ 75,787
Asset allocations by category	100.00%	100.00%
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 51,435	$ 65,355
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	34,745	22,009
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 25,986	$ 3,760
Asset allocations by category	30.20%	4.30%
Cash and cash equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 25,986	$ 3,760
Cash and cash equivalents [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and cash equivalents [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Obligations of U.S government-sponsored enterprises [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21,787	5,926
Obligations of U.S government-sponsored enterprises [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Obligations of U.S government-sponsored enterprises [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21,787	5,926
Obligations of U.S government-sponsored enterprises [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Obligations of states and political subdivisions [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,597	2,971
Obligations of states and political subdivisions [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Obligations of states and political subdivisions [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,597	2,971
Obligations of states and political subdivisions [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Corporate bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,361	13,112
Corporate bonds [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Corporate bonds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,361	13,112
Corporate bonds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Common stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,957	38,508
Common stocks [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,957	38,508
Common stocks [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Common stocks [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Mutual funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15,492	23,087
Mutual funds [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15,492	23,087
Mutual funds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Mutual funds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0
Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations by category	40.30%	30.00%
Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations by category	29.50%	65.70%

Employee Benefits (Estimated Fu

Employee Benefits (Estimated Future Benefit Payments) (Details) $ in Thousands	Dec. 31, 2018USD ($)
Qualified Pension Plan [Member]
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
Expected Future Payments, Next Twelve Months	$ 4,034
Expected Future Payments, Year Two	3,817
Expected Future Payments, Year Three	3,823
Expected Future Payments, Year Four	4,088
Expected Future Payments, Year Five	4,091
Expected Future Payments, Thereafter	28,295
Non-Qualified Retirement Plans [Member]
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
Expected Future Payments, Next Twelve Months	907
Expected Future Payments, Year Two	898
Expected Future Payments, Year Three	886
Expected Future Payments, Year Four	878
Expected Future Payments, Year Five	878
Expected Future Payments, Thereafter	$ 4,355

Share-Based Compensation Arra_3

Share-Based Compensation Arrangements (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Apr. 23, 2013	Apr. 28, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefit from stock option exercises and other equity awards	$ 496	$ 508	$ 1,016
Total unrecognized compensation cost	$ 4,400
Weighted average recognition period (in years)	2 years 12 days
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share options exercised total intrinsic value	$ 833	$ 1,000	$ 3,200
Cliff vesting period (years)	3 years	3 years	3 years
Time Based Nonvested Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested share units	13,430	15,900	22,175
Performance Based Nonvested Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance share awards minimum shares earned to target percentage	0.00%
Performance share awards maximum shares earned to target percentage	200.00%
Nonvested share units	41,454
Cliff vesting period (years)		3 years	3 years
Performance share awards, shares vesting	93,604
Minimum [Member] | Time Based Nonvested Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cliff vesting period (years)	3 years	3 years	3 years
Minimum [Member] | Performance Based Nonvested Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cliff vesting period (years)	3 years
Maximum [Member] | Time Based Nonvested Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cliff vesting period (years)	3 years	5 years
Maximum [Member] | Performance Based Nonvested Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cliff vesting period (years)	5 years
2013 Stock Option and Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized				1,748,250
Amended and Restated 2003 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized					1,200,000
Amended and Restated 2003 Stock Incentive Plan [Member] | Stock Options and Stock Appreciation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized					400,000

Share-Based Compensation Arra_4

Share-Based Compensation Arrangements (Compensation Cost for Share-based Compensation Arrangements) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based compensation expense	$ 2,602	$ 2,577	$ 2,190
Related income tax benefit	$ 1,108	$ 1,114	$ 810

Share-Based Compensation Arra_5

Share-Based Compensation Arrangements (Share Options Fair Value Assumptions) (Details) - Stock Options [Member] - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted	47,950	47,725	53,400
Cliff vesting period (years)	3 years	3 years	3 years
Expected term (years)	6 years 6 months	7 years	7 years 6 months
Expected dividend yield	3.39%	3.57%	3.89%
Weighted average expected volatility	22.73%	27.10%	29.99%
Weighted average risk-free interest rate	3.14%	1.70%	1.66%
Weighted average grant-date fair value	$ 9.74	$ 10.60	$ 7.92

Share-Based Compensation Arra_6

Share-Based Compensation Arrangements (Share Options Activity) (Details) - Stock Options [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Share Options:
Beginning of period	223,853
Granted	47,950	47,725	53,400
Exercised	(29,738)
Forfeited or expired	(19,450)
End of period	222,615	223,853
Options exercisable	87,990
Options expected to vest in future periods	134,625
Weighted Average Exercise Price (in dollars per share):
Beginning of period	$ 38.68
Granted	54.74
Exercised	27.57
Forfeited or expired	46.71
End of period	42.92	$ 38.68
Options exercisable	31.18
Options expected to vest in future periods	$ 50.60
Outstanding Weighted Average Remaining Contractual Term	7 years 1 month 24 days
Exercisable Weighted Average Remaining Contractual Term	4 years 8 months 5 days
Expected to Vest Weighted Average Remaining Contractual Term	8 years 9 months 2 days
Outstanding Aggregate Intrinsic Value	$ 1,790
Exercisable Aggregate Intrinsic Value	1,439
Expected to Vest Aggregate Intrinsic Value	$ 351

Share-Based Compensation Arra_7

Share-Based Compensation Arrangements (Stock Options Outstanding and Options Exercisable) (Details)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Share Options | shares	222,615
Options Outstanding, Weighted Average Remaining Life (Years)	7 years 1 month 24 days
Options Outstanding, Weighted Average Exercise Price	$ 42.92
Options Exercisable, Number of Share Options | shares	87,990
Options Exercisable, Weighted Average Exercise Price	$ 31.18
$15.01 to $20.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Ranges, Lower Range Limit	15.01
Exercise Price Ranges, Upper Range Limit	$ 20
Options Outstanding, Number of Share Options | shares	6,900
Options Outstanding, Weighted Average Remaining Life (Years)	1 year 5 months 1 day
Options Outstanding, Weighted Average Exercise Price	$ 17.52
Options Exercisable, Number of Share Options | shares	6,900
Options Exercisable, Weighted Average Exercise Price	$ 17.52
$20.01 to $25.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Ranges, Lower Range Limit	20.01
Exercise Price Ranges, Upper Range Limit	$ 25
Options Outstanding, Number of Share Options | shares	26,040
Options Outstanding, Weighted Average Remaining Life (Years)	3 years 25 days
Options Outstanding, Weighted Average Exercise Price	$ 23.06
Options Exercisable, Number of Share Options | shares	26,040
Options Exercisable, Weighted Average Exercise Price	$ 23.06
$25.01 to $30.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Ranges, Lower Range Limit	25.01
Exercise Price Ranges, Upper Range Limit	$ 30
Options Outstanding, Number of Share Options | shares	0
Options Outstanding, Weighted Average Remaining Life (Years)	0 years
Options Outstanding, Weighted Average Exercise Price	$ 0
Options Exercisable, Number of Share Options | shares	0
Options Exercisable, Weighted Average Exercise Price	$ 0
$30.01 to $35.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Ranges, Lower Range Limit	30.01
Exercise Price Ranges, Upper Range Limit	$ 35
Options Outstanding, Number of Share Options | shares	22,875
Options Outstanding, Weighted Average Remaining Life (Years)	4 years 11 months 22 days
Options Outstanding, Weighted Average Exercise Price	$ 32.76
Options Exercisable, Number of Share Options | shares	22,875
Options Exercisable, Weighted Average Exercise Price	$ 32.76
$35.01 to $40.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Ranges, Lower Range Limit	35.01
Exercise Price Ranges, Upper Range Limit	$ 40
Options Outstanding, Number of Share Options | shares	36,175
Options Outstanding, Weighted Average Remaining Life (Years)	6 years 5 months 20 days
Options Outstanding, Weighted Average Exercise Price	$ 39.35
Options Exercisable, Number of Share Options | shares	32,175
Options Exercisable, Weighted Average Exercise Price	$ 39.55
$40.01 to $45.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Ranges, Lower Range Limit	40.01
Exercise Price Ranges, Upper Range Limit	$ 45
Options Outstanding, Number of Share Options | shares	42,850
Options Outstanding, Weighted Average Remaining Life (Years)	7 years 9 months 18 days
Options Outstanding, Weighted Average Exercise Price	$ 40.25
Options Exercisable, Number of Share Options | shares	0
Options Exercisable, Weighted Average Exercise Price	$ 0
$45.01 to $50.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Ranges, Lower Range Limit	45.01
Exercise Price Ranges, Upper Range Limit	$ 50
Options Outstanding, Number of Share Options | shares	0
Options Outstanding, Weighted Average Remaining Life (Years)	0 years
Options Outstanding, Weighted Average Exercise Price	$ 0
Options Exercisable, Number of Share Options | shares	0
Options Exercisable, Weighted Average Exercise Price	$ 0
$50.01 to $55.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Ranges, Lower Range Limit	50.01
Exercise Price Ranges, Upper Range Limit	$ 55
Options Outstanding, Number of Share Options | shares	47,950
Options Outstanding, Weighted Average Remaining Life (Years)	9 years 9 months 17 days
Options Outstanding, Weighted Average Exercise Price	$ 54.74
Options Exercisable, Number of Share Options | shares	0
Options Exercisable, Weighted Average Exercise Price	$ 0
$55.01 to $60.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Ranges, Lower Range Limit	55.01
Exercise Price Ranges, Upper Range Limit	$ 60
Options Outstanding, Number of Share Options | shares	39,825
Options Outstanding, Weighted Average Remaining Life (Years)	8 years 9 months 17 days
Options Outstanding, Weighted Average Exercise Price	$ 58.05
Options Exercisable, Number of Share Options | shares	0
Options Exercisable, Weighted Average Exercise Price	$ 0

Share-Based Compensation Arra_8

Share-Based Compensation Arrangements (Nonvested Share Units Activity) (Details) - Time Based Nonvested Shares [Member] - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Shares:
Beginning of period	53,775
Granted	13,430	15,900	22,175
Vested	(18,805)
Forfeited	(3,050)
End of period	45,350	53,775
Weighted Average Grant Date Fair Value (in dollars per share):
Beginning of period	$ 43.13
Granted	55.71
Vested	37.87
Forfeited	47.75
End of period	$ 48.73	$ 43.13

Share-Based Compensation Arra_9

Share-Based Compensation Arrangements (Nonvested Performance Share Unit Awards Outstanding) (Details) - Performance Based Nonvested Shares [Member]	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance share awards, shares vesting	93,604
2018 Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance share awards granted, grant date fair value | $ / shares	$ 54.25
Performance share awards, shares vesting percentages	140.00%
Performance share awards, shares vesting	41,454
2017 Grant [Domain]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance share awards granted, grant date fair value | $ / shares	$ 51.85
Performance share awards, shares vesting percentages	150.00%
Performance share awards, shares vesting	24,150
2016 Grant [Domain]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance share awards granted, grant date fair value | $ / shares	$ 36.11
Performance share awards, shares vesting percentages	140.00%
Performance share awards, shares vesting	28,000

Share-Based Compensation Arr_10

Share-Based Compensation Arrangements (Nonvested Performance Share Units Activity) (Details) - Performance Based Nonvested Shares [Member]	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Number of Shares:
Beginning of period | shares	117,465
Granted | shares	41,454
Vested | shares	(36,729)
Forfeited | shares	(28,586)
End of period | shares	93,604
Weighted Average Grant Date Fair Value (in dollars per share):
Beginning of period | $ / shares	$ 41.58
Granted | $ / shares	54.25
Vested | $ / shares	38.02
Forfeited | $ / shares	42.83
End of period | $ / shares	$ 48.20

Business Segments (Statement of

Business Segments (Statement of Operations and Total Assets by Reportable Segment) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net interest income (expense)	$ 33,878	$ 33,449	$ 33,111	$ 31,852	$ 30,889	$ 30,059	$ 29,904	$ 28,679	$ 132,290	$ 119,531	$ 110,478
Provision for loan losses	800	350	400	0	200	1,300	700	400	1,550	2,600	5,650
Net interest income (expense) after provision for loan losses	33,078	33,099	32,711	31,852	30,689	28,759	29,204	28,279	130,740	116,931	104,828
Noninterest income	15,163	15,215	15,993	15,743	16,210	17,283	16,806	14,510	62,114	64,809	65,129
Depreciation and amortization expense									4,261	4,489	4,935
Other noninterest expenses									101,901	99,611	96,168
Total noninterest expense	26,682	26,062	26,288	27,130	25,754	26,754	26,306	25,286	106,162	104,100	101,103
Income before income taxes	21,559	22,252	22,416	20,465	21,145	19,288	19,704	17,503	86,692	77,640	68,854
Income tax expense	4,523	4,741	4,742	4,254	13,163	6,326	6,505	5,721	18,260	31,715	22,373
Net income	17,036	$ 17,511	$ 17,674	$ 16,211	7,982	$ 12,962	$ 13,199	$ 11,782	68,432	45,925	46,481
Total assets at period end	5,010,766				4,529,850				5,010,766	4,529,850	4,381,115
Expenditures for long-lived assets									3,974	2,779	3,112
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)									106,668	98,736	91,221
Provision for loan losses									1,550	2,600	5,650
Net interest income (expense) after provision for loan losses									105,118	96,136	85,571
Noninterest income									21,509	23,244	24,783
Depreciation and amortization expense									2,589	2,604	2,771
Other noninterest expenses									62,673	60,828	58,452
Total noninterest expense									65,262	63,432	61,223
Income before income taxes									61,365	55,948	49,131
Income tax expense									13,149	23,876	16,790
Net income									48,216	32,072	32,341
Total assets at period end	3,804,021				3,491,845				3,804,021	3,491,845	3,354,633
Expenditures for long-lived assets									3,415	2,224	2,267
Wealth Management Services [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)									(334)	(167)	(66)
Provision for loan losses									0	0	0
Net interest income (expense) after provision for loan losses									(334)	(167)	(66)
Noninterest income									38,341	39,346	37,569
Depreciation and amortization expense									1,501	1,689	1,940
Other noninterest expenses									26,222	26,718	25,239
Total noninterest expense									27,723	28,407	27,179
Income before income taxes									10,284	10,772	10,324
Income tax expense									2,577	3,795	3,692
Net income									7,707	6,977	6,632
Total assets at period end	71,254				66,083				71,254	66,083	64,625
Expenditures for long-lived assets									407	360	464
Corporate [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)									25,956	20,962	19,323
Provision for loan losses									0	0	0
Net interest income (expense) after provision for loan losses									25,956	20,962	19,323
Noninterest income									2,264	2,219	2,777
Depreciation and amortization expense									171	196	224
Other noninterest expenses									13,006	12,065	12,477
Total noninterest expense									13,177	12,261	12,701
Income before income taxes									15,043	10,920	9,399
Income tax expense									2,534	4,044	1,891
Net income									12,509	6,876	7,508
Total assets at period end	$ 1,135,491				$ 971,922				1,135,491	971,922	961,857
Expenditures for long-lived assets									$ 152	$ 195	$ 381

Other Comprehensive Income (L_3

Other Comprehensive Income (Loss) (Activity in Other Comprehensive Income) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Change in fair value of securities available for sale, before tax		$ (12,063)		$ 986		$ (12,502)
Change in fair value of securities available for sale, tax		(2,835)		365		(4,626)
Change is fair value of securities available for sale		(9,228)		621		(7,876)
Net (gains) losses on securities classified into earnings, before tax		0		0		0
Net (gains) losses on securities classified into earnings, tax		0		0		0
Net (gains) losses on securities classified into earnings		0		0		0
Net change in fair value of securities available for sale, before tax		(12,063)		986		(12,502)
Net change in fair value of securities available for sale, tax		(2,835)		365		(4,626)
Net change in fair value of securities available for sale		(9,228)		621		(7,876)
Net change in fair value of cash flow hedges, before tax		639		(774)		(403)
Net change in fair value of cash flow hedges, tax		151		(223)		(146)
Change in fair value of cash flow hedges		488		(551)		(257)
Net cash flow hedge losses reclassified into earnings, before tax		170	[1]	792	[1]	0
Net cash flow hedge losses reclassified into earnings, tax		39	[1]	293	[1]	0
Net cash flow hedge losses reclassified into earnings		131	[1]	499	[1]	0
Change in fair value of cash flow hedges, before tax		809		18		(403)
Change in fair value of cash flow hedges, tax		190		70		(146)
Net change in fair value of cash flow hedges		619		(52)		(257)
Defined benefit plan obligation adjustment, before tax		3,098		(1,591)		(4,106)
Defined benefit plan obligation adjustment, tax		729		(594)		(1,518)
Defined benefit plan obligation adjustment		2,369		(997)		(2,588)
Amortization of net actuarial losses, before tax	[2]	1,907		1,461		1,075
Amortization of net actuarial losses, tax	[2]	448		546		397
Amortization of net actuarial losses	[2]	1,459		915		678
Amortization of net prior service credits, before tax	[2]	(24)		(24)		(24)
Amortization of net prior service credits, tax	[2]	(6)		(9)		(9)
Amortization of net prior service credits	[2]	(18)		(15)		(15)
Net change in defined benefit plan obligations, before tax		4,981		(154)		(3,055)
Net change in defined benefit plan obligations, tax		1,171		(57)		(1,130)
Net change in defined benefit plan obligations		3,810		(97)		(1,925)
Total other comprehensive income (loss), before tax		(6,273)		850		(15,960)
Total other comprehensive income (loss), tax		(1,474)		378		(5,902)
Total other comprehensive (loss) income, net of tax		(4,799)		472		(10,058)
Net Unrealized Gains (Losses) on AFS Securities [Member]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Total other comprehensive (loss) income, net of tax		$ (9,228)		$ 621		$ (7,876)
[1]	The pre-tax amounts are included in interest expense on FHLB advances, interest expense on junior subordinated debentures and interest and fees on loans in the Consolidated Statements of Income.
[2]	The pre-tax amounts are included in other expenses in the Consolidated Statements of Income.

Other Comprehensive Income (L_4

Other Comprehensive Income (Loss) (Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated other comprehensive income (loss), beginning balance	$ (23,510)
Net other comprehensive income (loss)	(4,799)	$ 472	$ (10,058)
Reclassification of income tax effects due to the adoption of ASU 2018-02		0
Accumulated other comprehensive income (loss), ending balance	(28,309)	(23,510)
Net Unrealized Gains (Losses) on AFS Securities [Member]
Accumulated other comprehensive income (loss), beginning balance	(7,534)	(6,825)	1,051
Other comprehensive income (loss) before reclassifications, net of tax	(9,228)	621	(7,876)
Amounts reclassified from accumulated other comprehensive income, net of tax	0	0	0
Net other comprehensive income (loss)	(9,228)	621	(7,876)
Reclassification of income tax effects due to the adoption of ASU 2018-02		(1,330)
Accumulated other comprehensive income (loss), ending balance	(16,762)	(7,534)	(6,825)
Net Unrealized Gains (Losses) on Cash Flow Hedges [Member]
Accumulated other comprehensive income (loss), beginning balance	(428)	(300)	(43)
Other comprehensive income (loss) before reclassifications, net of tax	488	(551)	(257)
Amounts reclassified from accumulated other comprehensive income, net of tax	131	499	0
Net other comprehensive income (loss)	619	(52)	(257)
Reclassification of income tax effects due to the adoption of ASU 2018-02		(76)
Accumulated other comprehensive income (loss), ending balance	191	(428)	(300)
Defined Benefit Pension Plan Adjustment [Member]
Accumulated other comprehensive income (loss), beginning balance	(15,548)	(12,632)	(10,707)
Other comprehensive income (loss) before reclassifications, net of tax	2,369	(741)	(2,588)
Amounts reclassified from accumulated other comprehensive income, net of tax	1,441	644	663
Net other comprehensive income (loss)	3,810	(97)	(1,925)
Reclassification of income tax effects due to the adoption of ASU 2018-02		(2,819)
Accumulated other comprehensive income (loss), ending balance	(11,738)	(15,548)	(12,632)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated other comprehensive income (loss), beginning balance	(23,510)	(19,757)	(9,699)
Other comprehensive income (loss) before reclassifications, net of tax	(6,371)	(671)	(10,721)
Amounts reclassified from accumulated other comprehensive income, net of tax	1,572	1,143	663
Net other comprehensive income (loss)	(4,799)	472	(10,058)
Reclassification of income tax effects due to the adoption of ASU 2018-02		(4,225)
Accumulated other comprehensive income (loss), ending balance	$ (28,309)	$ (23,510)	$ (19,757)

Earnings Per Common Share (Deta

Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net income	$ 17,036	$ 17,511	$ 17,674	$ 16,211	$ 7,982	$ 12,962	$ 13,199	$ 11,782	$ 68,432	$ 45,925	$ 46,481
Less dividends and undistributed earnings allocated to participating securities									(144)	(108)	(97)
Net income available to common shareholders									$ 68,288	$ 45,817	$ 46,384
Weighted average common shares outstanding - basic	17,297,000	17,283,000	17,272,000	17,234,000	17,223,000	17,212,000	17,206,000	17,186,000	17,272,000	17,207,000	17,081,000
Basic earnings per common share (in dollars per share)	$ 0.98	$ 1.01	$ 1.02	$ 0.94	$ 0.46	$ 0.75	$ 0.77	$ 0.68	$ 3.95	$ 2.66	$ 2.72
Less dividends and undistributed earnings allocated to participating securities									$ (144)	$ (108)	$ (97)
Net income available to common shareholders	$ 17,004	$ 17,475	$ 17,636	$ 16,173	$ 7,958	$ 12,934	$ 13,170	$ 11,755	$ 68,288	$ 45,817	$ 46,384
Dilutive effect of common stock equivalents (in shares)									119,000	131,000	127,000
Weighted average common shares outstanding - diluted (in shares)	17,385,000	17,382,000	17,387,000	17,345,000	17,349,000	17,318,000	17,316,000	17,293,000	17,391,000	17,338,000	17,208,000
Diluted earnings per common share (in dollars per share)	$ 0.98	$ 1.01	$ 1.01	$ 0.93	$ 0.46	$ 0.75	$ 0.76	$ 0.68	$ 3.93	$ 2.64	$ 2.70
Antidilutive common stock equivalents									55,821	11,572	59,158

Commitments and Contingencies_2

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Line Items]
Standby letters of credit extension period	1 year
Operating leases rental expense	$ 4,300	$ 4,300	$ 4,000
Unpaid principal balance of loans repurchased	1,200	1,300
Reserve for loans repurchases	$ 140	180
Minimum [Member]
Commitments and Contingencies Disclosure [Line Items]
Lease expiration period	5 months
Lease expiration period, renewal option	1 year
Maximum [Member]
Commitments and Contingencies Disclosure [Line Items]
Lease expiration period	22 years
Lease expiration period, renewal option	5 years
Commitments to extend credit on standby letters of credit [Member] | Commitments to Extend Credit [Member]
Commitments and Contingencies Disclosure [Line Items]
Contract Amount	$ 7,706	$ 6,666

Commitments and Contingencies_3

Commitments and Contingencies (Financial Instruments with Off Balance Sheet Risk) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Interest rate lock commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	$ 30,766	$ 45,139
Commitments to sell mortgage loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	61,993	71,539
Interest rate swaps with customers [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	648,050	545,049
Mirror swaps with counterparties [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	648,050	545,049
Risk participation-in agreement [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	46,510	34,052
Foreign exchange contracts [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	2,784	3,005
Interest rate swaps [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount	60,000	60,000
Commitments to Extend Credit [Member] | Commitments to extend credit on commerical loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract Amount	533,884	537,310
Commitments to Extend Credit [Member] | Commitments to extend credit on home equity lines [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract Amount	270,462	254,855
Commitments to Extend Credit [Member] | Commitments to extend credit on other loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract Amount	46,698	48,819
Commitments to Extend Credit [Member] | Commitments to extend credit on standby letters of credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract Amount	$ 7,706	$ 6,666

Commitments and Contingencies_4

Commitments and Contingencies (Schedule of Future Minimum Operating Lease Payments) (Details) $ in Thousands	Dec. 31, 2018USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Future Minimum Payments, Next Twelve Months	$ 3,544
Future Minimum Payments, Year Two	2,980
Future Minimum Payments, Year Three	2,677
Future Minimum Payments, Year Four	2,293
Future Minimum Payments, Year Five	2,059
Future Minimum Payments, Thereafter	22,648
Total minimum lease payments	$ 36,201

Parent Company Financial Stat_3

Parent Company Financial Statements (Balance Sheet) (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets:
Other assets	$ 77,175	$ 63,740
Total assets	5,010,766	4,529,850	$ 4,381,115
Liabilities:
Junior subordinated debentures	22,681	22,681
Contingent consideration liability	0	1,404	2,047
Other liabilities	65,131	59,822
Total liabilities	4,562,582	4,116,566
Shareholders’ Equity:
Common stock of $.0625 par value; authorized 60,000,000 shares; issued and outstanding 17,302,037 shares in 2018 and 17,226,508 shares in 2017	1,081	1,077
Paid-in capital	119,888	117,961
Retained earnings	355,524	317,756
Accumulated other comprehensive loss	(28,309)	(23,510)
Total shareholders’ equity	448,184	413,284	$ 390,804	$ 375,388
Total liabilities and shareholders’ equity	$ 5,010,766	$ 4,529,850
Common stock, par value (in dollars per share)	$ 0.0625	$ 0.0625
Common stock, shares authorized (in shares)	60,000,000	60,000,000
Common stock, shares issued (in shares)	17,302,037	17,226,508
Common stock, shares outstanding (in shares)	17,302,037	17,226,508
Parent Company [Member]
Assets:
Cash on deposit with bank subsidiary	$ 1,912	$ 1,664
Dividends receivable from bank subsidiary	7,762	7,770
Other assets	190	259
Total assets	479,390	444,524
Liabilities:
Junior subordinated debentures	22,681	22,681
Dividends payable	8,439	7,087
Contingent consideration liability	0	1,404
Other liabilities	86	68
Total liabilities	31,206	31,240
Shareholders’ Equity:
Common stock of $.0625 par value; authorized 60,000,000 shares; issued and outstanding 17,302,037 shares in 2018 and 17,226,508 shares in 2017	1,081	1,077
Paid-in capital	119,888	117,961
Retained earnings	355,524	317,756
Accumulated other comprehensive loss	(28,309)	(23,510)
Total shareholders’ equity	448,184	413,284
Total liabilities and shareholders’ equity	479,390	444,524
Bank [Member]
Assets:
Investment in subsidiaries at equity value:	467,657	433,010
Non-bank [Member]
Assets:
Investment in subsidiaries at equity value:	$ 1,869	$ 1,821

Parent Company Financial Stat_4

Parent Company Financial Statements (Statement of Income) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income:
Total income									$ 194,404	$ 184,340	$ 175,607
Expenses:
Interest on junior subordinated debentures									869	613	491
Legal and professional fees									2,427	2,294	2,579
Change in fair value of contingent consideration									(187)	(643)	(898)
Income before income taxes	$ 21,559	$ 22,252	$ 22,416	$ 20,465	$ 21,145	$ 19,288	$ 19,704	$ 17,503	86,692	77,640	68,854
Income tax benefit (expense)	(4,523)	(4,741)	(4,742)	(4,254)	(13,163)	(6,326)	(6,505)	(5,721)	(18,260)	(31,715)	(22,373)
Net income	$ 17,036	$ 17,511	$ 17,674	$ 16,211	$ 7,982	$ 12,962	$ 13,199	$ 11,782	68,432	45,925	46,481
Parent Company [Member]
Income:
Other income									0	0	1
Total income									32,418	27,918	24,557
Expenses:
Interest on junior subordinated debentures									869	613	491
Legal and professional fees									187	169	98
Change in fair value of contingent consideration									(187)	(643)	(898)
Other									324	298	282
Total expenses									1,193	437	(27)
Income before income taxes									31,225	27,481	24,584
Income tax benefit (expense)									284	340	(15)
Income before equity in undistributed earnings of subsidiaries									31,509	27,821	24,569
Net income									68,432	45,925	46,481
Bank [Member]
Income:
Dividends from subsidiaries									32,394	27,900	24,442
Expenses:
Equity in undistributed earnings (losses) of subsidiaries									36,876	18,193	22,008
Non-bank [Member]
Income:
Dividends from subsidiaries									24	18	114
Expenses:
Equity in undistributed earnings (losses) of subsidiaries									$ 47	$ (89)	$ (96)

Parent Company Financial Stat_5

Parent Company Financial Statements (Statements of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Payment of contingent consideration liability									$ (1,217)	$ 0	$ 0
Cash flows from operating activities:
Net income	$ 17,036	$ 17,511	$ 17,674	$ 16,211	$ 7,982	$ 12,962	$ 13,199	$ 11,782	68,432	45,925	46,481
Adjustments to reconcile net income to net cash provided by operating activities:
(Increase) decrease in other assets									(7,456)	(8,794)	984
Change in fair value of contingent consideration									(187)	(643)	(898)
Tax benefit from stock option exercises and other equity awards									496	508	1,016
Net cash provided by operating activities									82,876	59,385	59,749
Cash flows from investing activities:
Net cash used in investing activities									(481,831)	(179,706)	(625,377)
Cash flows from financing activities:
Proceeds from stock option exercises and issuance of other equity awards, net of awards surrendered									(671)	366	977
Cash dividends paid									(29,312)	(26,300)	(24,637)
Net cash provided by financing activities									409,507	95,447	575,794
Net increase (decrease) in cash and cash equivalents									10,552	(24,874)	10,166
Cash and cash equivalents at beginning of year				82,923		$ 82,923		107,797	82,923	107,797	97,631
Cash and cash equivalents at end of year	93,475				82,923		$ 82,923		93,475	82,923	107,797
Parent Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Payment of contingent consideration liability									(1,217)	0	0
Cash flows from operating activities:
Net income									68,432	45,925	46,481
Adjustments to reconcile net income to net cash provided by operating activities:
Decrease (increase) in dividend receivable									8	(1,252)	(1,436)
(Increase) decrease in other assets									70	72	45
Increase (decrease) in accrued expenses and other liabilities									17	22	(12)
Change in fair value of contingent consideration									(187)	(643)	(898)
Tax benefit from stock option exercises and other equity awards									496	508	1,016
Other, net									(465)	(673)	(1,051)
Net cash provided by operating activities									31,448	25,855	22,233
Cash flows from financing activities:
Proceeds from stock option exercises and issuance of other equity awards, net of awards surrendered									(671)	366	978
Cash dividends paid									(29,312)	(26,300)	(24,637)
Net cash provided by financing activities									(31,200)	(25,934)	(23,659)
Net increase (decrease) in cash and cash equivalents									248	(79)	(1,426)
Cash and cash equivalents at beginning of year				$ 1,664				$ 1,743	1,664	1,743	3,169
Cash and cash equivalents at end of year	$ 1,912				$ 1,664				1,912	1,664	1,743
Bank [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Bank									(36,876)	(18,193)	(22,008)
Non-bank [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Bank									$ (47)	$ 89	$ 96

Selected Quarterly Consolidat_3

Selected Quarterly Consolidated Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Interest and dividend income	$ 47,517	$ 45,164	$ 43,286	$ 40,440	$ 38,900	$ 37,869	$ 37,153	$ 35,664	$ 176,407	$ 149,586	$ 133,470
Interest expense	13,639	11,715	10,175	8,588	8,011	7,810	7,249	6,985	44,117	30,055	22,992
Net interest income	33,878	33,449	33,111	31,852	30,889	30,059	29,904	28,679	132,290	119,531	110,478
Provision for loan losses	800	350	400	0	200	1,300	700	400	1,550	2,600	5,650
Net interest income after provision for loan losses	33,078	33,099	32,711	31,852	30,689	28,759	29,204	28,279	130,740	116,931	104,828
Noninterest income	15,163	15,215	15,993	15,743	16,210	17,283	16,806	14,510	62,114	64,809	65,129
Noninterest expense	26,682	26,062	26,288	27,130	25,754	26,754	26,306	25,286	106,162	104,100	101,103
Income before income taxes	21,559	22,252	22,416	20,465	21,145	19,288	19,704	17,503	86,692	77,640	68,854
Income tax expense	4,523	4,741	4,742	4,254	13,163	6,326	6,505	5,721	18,260	31,715	22,373
Net income	17,036	17,511	17,674	16,211	7,982	12,962	13,199	11,782	68,432	45,925	46,481
Net income available to common shareholders	$ 17,004	$ 17,475	$ 17,636	$ 16,173	$ 7,958	$ 12,934	$ 13,170	$ 11,755	$ 68,288	$ 45,817	$ 46,384
Weighted average common shares outstanding - basic	17,297	17,283	17,272	17,234	17,223	17,212	17,206	17,186	17,272	17,207	17,081
Weighted average common shares outstanding - diluted	17,385	17,382	17,387	17,345	17,349	17,318	17,316	17,293	17,391	17,338	17,208
Basic earnings per common share (in dollars per share)	$ 0.98	$ 1.01	$ 1.02	$ 0.94	$ 0.46	$ 0.75	$ 0.77	$ 0.68	$ 3.95	$ 2.66	$ 2.72
Diluted earnings per common share (in dollars per share)	0.98	1.01	1.01	0.93	0.46	0.75	0.76	0.68	3.93	2.64	2.70
Cash dividends declared per share (in dollars per share)	$ 0.47	$ 0.43	$ 0.43	$ 0.43	$ 0.39	$ 0.39	$ 0.38	$ 0.38	$ 1.76	$ 1.54	$ 1.46