Independent Bank (INDB) 10-K 27 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 23, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Independent Bank Corp
Entity Central Index Key	776,901
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float	$ 1,788,617,441
Entity Common Stock, Shares Outstanding		27,505,766

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 103,485,000	$ 97,196,000
Interest-earning deposits with banks	109,631,000	191,899,000
Securities
Trading Securities	1,324,000	804,000
Securities - available for sale	447,498,000	363,644,000
Securities - held to maturity (fair value $494,194 and $485,650)	497,688,000	487,076,000
Total securities	946,510,000	851,524,000
Loans held for sale (at fair value)	4,768,000	6,139,000
Loans
Commercial and industrial	888,528,000	902,053,000
Commercial real estate	3,116,561,000	3,010,798,000
Commercial construction	401,797,000	320,391,000
Small business	132,370,000	122,726,000
Residential real estate	754,329,000	644,426,000
Loans and Leases Receivable Consumer Home Equity in First Position	612,990,000	577,006,000
Loans and Leases Receivable Consumer Home Equity in Subordinated Position	439,098,000	411,141,000
Other consumer	9,880,000	11,064,000
Total loans	6,355,553,000	5,999,605,000
Less: allowance for loan losses	(60,643,000)	(61,566,000)
Net loans	6,294,910,000	5,938,039,000
Federal Home Loan Bank stock	11,597,000	11,497,000
Bank premises and equipment, net	94,722,000	78,480,000
Goodwill	231,806,000	221,526,000
Other intangible assets	9,341,000	9,848,000
Cash surrender value of life insurance policies	151,528,000	144,503,000
Other real estate owned and other foreclosed assets	612,000	4,173,000
Other assets	123,119,000	154,551,000
Total assets	8,082,029,000	7,709,375,000
Deposits
Demand deposits	2,159,396,000	2,057,086,000
Savings and interest checking accounts	2,599,922,000	2,469,237,000
Money market	1,325,634,000	1,236,778,000
Time certificates of deposit of $100,000 and over	278,531,000	266,190,000
Other time certificates of deposits	365,770,000	382,962,000
Total deposits	6,729,253,000	6,412,253,000
Borrowings
Advances from Federal Home Loan Banks	53,264,000	50,819,000
Securities Sold under Agreements to Repurchase	162,679,000	176,913,000
Junior subordinated debentures (less unamortized debt issuance costs $125 and $136)	73,073,000	73,107,000
Subordinated debentures (less unamortized debt issuance costs of $318 and $365)	34,682,000	34,635,000
Total borrowings	323,698,000	335,474,000
Other liabilities	85,269,000	96,958,000
Total liabilities	7,138,220,000	6,844,685,000
Commitments and contingencies
Stockholders' Equity
Preferred stock, $.01 par value. authorized: 1,000,000 shares, outstanding: none	0	0
Common stock, $.01 par value. authorized: 75,000,000 shares, issued and outstanding: 27,450,190 shares at December 31, 2017 and 27,005,813 shares at December 31, 2016 (includes 177,191 and 212,698 shares of unvested participating restricted stock awards, respectively)	273,000	268,000
Value of shares held in rabbi trust at cost: 164,438 shares at December 31, 2017 and 170,036 shares at December 31, 2016	(4,590,000)	(4,277,000)
Compensation and Benefits Trust	4,590,000	4,277,000
Additional paid in capital	479,430,000	451,664,000
Retained earnings	465,937,000	414,095,000
Accumulated other comprehensive loss, net of tax	(1,831,000)	(1,337,000)
Total stockholders' equity	943,809,000	864,690,000
Liabilities and Equity	$ 8,082,029,000	$ 7,709,375,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Time certificates of deposit least amount	$ 100,000	$ 100,000
Securities held to maturity, fair value	$ 494,194,000	$ 485,650,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	27,450,190	27,005,813
Common stock, unvested restricted Stock awards	177,191	212,698
Shares held in rabbit trust at cost	164,438	170,036
Common Stock Outstanding
Common stock, shares outstanding	27,450,190	27,005,813
Junior Subordinated Debt [Member]
Unamortized Debt Issuance Expense	$ 125,000,000	$ 136,000,000
Subordinated Debt [Member]
Unamortized Debt Issuance Expense	$ 318,000,000	$ 365,000

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income
Interest and fees on loans	$ 253,131,000	$ 224,244,000	$ 214,724,000
Interest Income, Securities, Operating, Taxable	22,465,000	20,851,000	20,120,000
Nontaxable interest and dividends on securities	88,000	117,000	127,000
Interest on loans held for sale	92,000	235,000	225,000
Interest on federal funds sold and short-term investments	1,418,000	1,190,000	349,000
Total interest and dividend income	277,194,000	246,637,000	235,545,000
Interest expense
Interest on deposits	12,702,000	11,140,000	11,576,000
Interest on borrowings	5,632,000	7,653,000	9,041,000
Total interest expense	18,334,000	18,793,000	20,617,000
Net interest income	258,860,000	227,844,000	214,928,000
Provision (benefit)	2,950,000	6,075,000	1,500,000
Net interest income after provision for loan losses	255,910,000	221,769,000	213,428,000
Noninterest income
Deposit account fees	17,822,000	18,652,000	18,560,000
Interchange and ATM fees	17,291,000	16,210,000	14,728,000
Investment management	23,802,000	21,809,000	20,735,000
Fees and Commission Mortgage Banking	4,960,000	6,607,000	5,163,000
Increase in cash surrender value of life insurance policies	4,127,000	4,089,000	3,692,000
Available-For-Sale Securities - Fixed Income Gross Realized Gains	0	0	798,000
Gain (Loss) on Sale of Equity Investments	19,000	6,000	20,000
Loan level derivative income	3,836,000	6,155,000	3,830,000
Other noninterest income	11,137,000	8,900,000	8,362,000
Total noninterest income	82,994,000	82,428,000	75,888,000
Noninterest expenses
Salaries and employee benefits	116,600,000	108,636,000	105,068,000
Occupancy and equipment expenses	24,693,000	22,867,000	23,020,000
Data processing & facilities management	4,988,000	4,975,000	4,631,000
FDIC assessment	3,068,000	3,380,000	3,979,000
Advertising expense	4,989,000	5,202,000	4,645,000
Consulting expense	4,038,000	3,486,000	3,680,000
Debit Card Expense	3,430,000	2,993,000	2,456,000
Gains (Losses) on Extinguishment of Debt	0	437,000	122,000
Available-for-Sale Securities - Fixed Income Gross Realized Losses	0	0	1,124,000
Available-For-Sale Securities - Equity Gross Realized Losses	16,000	32,000	99,000
Merger and acquisition expense	3,393,000	5,455,000	10,501,000
Software Maintenance	3,636,000	3,061,000	2,759,000
Other noninterest expenses	35,508,000	31,598,000	35,054,000
Total noninterest expenses	204,359,000	192,122,000	197,138,000
Income before income taxes	134,545,000	112,075,000	92,178,000
Provision for income taxes	47,341,000	35,427,000	27,218,000
Net Income	$ 87,204,000	$ 76,648,000	$ 64,960,000
Basic earnings per share (in dollars per share)	$ 3.19	$ 2.90	$ 2.51
Diluted earnings per share (in dollars per share)	$ 3.19	$ 2.90	$ 2.50
Weighted average common shares (basic) (in shares)	27,294,028	26,404,071	25,891,382
Common share equivalents (in shares)	78,076	51,847	68,566
Weighted average common shares (diluted) (in shares)	27,372,104	26,455,918	25,959,948
Retained Earnings
Noninterest expenses
Net Income	$ 87,204,000	$ 76,648,000	$ 64,960,000
Cash dividends declared (in dollars per share)	$ 1.28	$ 1.16	$ 1.04

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income		$ 87,204	$ 76,648	$ 64,960
Other comprehensive income (loss), net of tax
Net change in fair value of securities available for sale		(677)	(1,133)	(2,083)
Net change in fair value of cash flow hedges		443	2,170	1,199
Net change in other comprehensive income for defined benefit postretirement plans	[1]	(260)	78	564
Total other comprehensive income (loss)		(494)	1,115	(320)
Total comprehensive income		$ 86,710	$ 77,763	$ 64,640
[1]	The amortization of prior service costs is included in the computation of net periodic pension costs as disclosed in Note 15 - Employee Benefit Plans.

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands		Total	Common Stock Outstanding	Common Stock	Value of Shares Held in Rabbi Trust at Cost	Deferred Compensation Obligation	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Common Stock, Dividends, Per Share, Declared								$ 1.04
Beginning balance at Dec. 31, 2014		$ 640,527		$ 237	$ (3,666)	$ 3,666	$ 311,978	$ 330,444	$ (2,132)
Beginning balance (in shares) at Dec. 31, 2014			23,998,738
Net income		64,960						64,960
Other comprehensive loss		(320)							(320)
Common dividend declared		(27,235)						(27,235)
Common stock issued for acquisition		86,415		21			86,394
Common stock issued for acquisition (in shares)			2,052,137
Proceeds from exercise of stock options, net of cash paid		1,367		1			1,366
Proceeds from exercise of stock options (in shares)			100,794
Tax benefit related to equity award activity		1,042					1,042
Stock based compensation		2,490					2,490
Restricted stock awards issued, net of awards surrendered (in shares)			23,851
Restricted stock awards issued, net of awards surrendered		(657)		1			(658)
Stock Issued During Period, Shares, Other			60,832
Stock Issued During Period, Value, Other		2,695					2,695
Increase (Decrease) in Deferred Compensation					(292)	292
Tax benefit related to deferred compensation distributions		179					179
Ending balance (in shares) at Dec. 31, 2015			26,236,352
Ending balance at Dec. 31, 2015		771,463		260	(3,958)	3,958	405,486	$ 368,169	(2,452)
Common Stock, Dividends, Per Share, Declared								$ 1.16
Net income		76,648						$ 76,648
Other comprehensive loss		1,115							1,115
Common dividend declared		(30,722)						(30,722)
Common stock issued for acquisition		40,730		7			40,723
Common stock issued for acquisition (in shares)			672,665
Proceeds from exercise of stock options, net of cash paid		201		0			201
Proceeds from exercise of stock options (in shares)			13,449
Tax benefit related to equity award activity		476					476
Stock based compensation		2,965					2,965
Restricted stock awards issued, net of awards surrendered (in shares)			33,432
Restricted stock awards issued, net of awards surrendered		(696)		1			(697)
Stock Issued During Period, Shares, Other			49,915
Stock Issued During Period, Value, Other		2,323					2,323
Increase (Decrease) in Deferred Compensation		0			(319)	319
Tax benefit related to deferred compensation distributions		187					187
Ending balance (in shares) at Dec. 31, 2016			27,005,813
Ending balance at Dec. 31, 2016		864,690		268	(4,277)	4,277	451,664	$ 414,095	(1,337)
Common Stock, Dividends, Per Share, Declared								$ 1.28
Net income		87,204						$ 87,204
Other comprehensive loss		(494)							(494)
Common dividend declared		(34,997)						(34,997)
Common stock issued for acquisition		23,468		4			23,464
Common stock issued for acquisition (in shares)			369,286
Proceeds from exercise of stock options, net of cash paid		214					214
Proceeds from exercise of stock options (in shares)			19,340
Stock based compensation		3,333					3,333
Restricted stock awards issued, net of awards surrendered (in shares)			31,665
Restricted stock awards issued, net of awards surrendered		(1,422)		1			(1,423)
Stock Issued During Period, Shares, Other			24,086
Stock Issued During Period, Value, Other		1,636					1,636
Increase (Decrease) in Deferred Compensation and Other Retirement Benefits					(313)	313
Ending balance (in shares) at Dec. 31, 2017			27,450,190
Ending balance at Dec. 31, 2017		943,809		$ 273	$ (4,590)	$ 4,590	479,430	465,937	$ (1,831)
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	[1]	$ 177					$ 542	$ (365)
[1]	Represents adjustment needed to reflect the cumulative impact on retained earnings for previously recognized stock based compensation, which included an adjustment for estimated forfeitures. Pursuant to the Company's adoption of Accounting Standards Update 2016-09, the Company has elected to recognize stock based compensation without inclusion of a forfeiture estimate, and as such has recognized this adjustment to present retained earnings consistent with this election.

Consolidated Statements of Cash

Consolidated Statements of Cash Flows	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Cash flow from operating activities
Net income	$ 87,204,000	$ 76,648,000	$ 64,960,000
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	15,681,000	14,354,000	12,307,000
Provision for loan losses	2,950,000	6,075,000	1,500,000
Deferred income tax expense (benefit)	9,211,000	(5,000)	10,220,000
Tax Expense related to a change in tax law	466,000	0	0
Loss on write-down of investments in securities available for sale	(3,000)	26,000	405,000
Net (gain) loss on bank premises and equipment	(108,000)	114,000	221,000
Loss on extinguishment of debt	0	437,000	122,000
Net loss on other real estate owned and foreclosed assets	288,000	29,000	1,152,000
Realized gain on sale leaseback transaction	(1,034,000)	(1,034,000)	(1,034,000)
Stock based compensation	3,333,000	2,965,000	2,490,000
Excess tax benefit related to equity award activity	0	(476,000)	(1,042,000)
Increase in cash surrender value of life insurance policies	(4,127,000)	(4,089,000)	(3,692,000)
Change in Fair Value on Loans Held for Sale	113,000	(87,000)	22,000
Net change in:
Trading assets	(520,000)	(448,000)	(356,000)
Loans held for sale	1,258,000	(62,000)	876,000
Other assets	20,022,000	7,627,000	3,842,000
Other liabilities	(3,825,000)	(8,738,000)	(2,450,000)
Total adjustments	43,705,000	16,688,000	24,583,000
Net cash provided by operating activities	130,909,000	93,336,000	89,543,000
Cash flows used in investing activities
Proceeds from sales of securities available for sale	1,027,000	618,000	14,199,000
Proceeds from maturities and principal repayments of securities available for sale	54,191,000	69,775,000	78,497,000
Purchases of securities available for sale	(140,885,000)	(69,671,000)	(73,064,000)
Proceeds from maturities and principal repayments of securities held to maturity	78,757,000	90,991,000	60,168,000
Purchases of securities held to maturity	(89,033,000)	(100,198,000)	(162,021,000)
Net redemption of Federal Home Loan Bank stock	386,000	5,229,000	23,054,000
Investments in low income housing projects	(7,645,000)	(7,626,000)	(15,055,000)
Purchases of life insurance policies	(164,000)	(163,000)	(162,000)
Net increase in loans	(204,702,000)	(227,838,000)	(114,550,000)
Cash Acquired in Excess of Payments to Acquire Business	6,289,000	8,668,000
Net cash acquired (used) in business combinations			(13,448,000)
Purchases of bank premises and equipment	(25,080,000)	(10,395,000)	(10,488,000)
Proceeds from the sale of bank premises and equipment	6,306,000	345,000	1,233,000
Proceeds from the sale of other real estate owned and foreclosed assets	3,784,000	1,583,000	7,667,000
Net payments relating to other real estate owned and foreclosed assets	0	(204,000)	(1,571,000)
Net cash used in investing activities	(316,769,000)	(238,886,000)	(205,541,000)
Cash flows provided by financing activities
Net decrease in time deposits	(19,509,000)	(104,803,000)	(80,726,000)
Net increase in other deposits	177,241,000	350,739,000	428,713,000
Net repayments of short-term Federal Home Loan Bank borrowings	0	(37,000,000)	(10,000,000)
Repayments of long-term Federal Home Loan Bank borrowings	0	(65,791,000)	(9,000,000)
Net increase (decrease) in customer repurchase agreements	(14,234,000)	42,955,000	(13,932,000)
Increase (Decrease) in Payables under Repurchase Agreements	0	0	(50,000,000)
Repayments of Subordinated Debt	0	0	(30,000,000)
Net proceeds from exercise of stock options	214,000	201,000	1,367,000
Restricted stock awards issued, net of awards surrendered	(1,422,000)	(696,000)	(657,000)
Excess tax benefit from stock based compensation		476,000	1,042,000
Tax benefit from deferred compensation distribution		187,000	179,000
Proceeds from shares issued under the direct stock purchase plan	1,636,000	2,323,000	2,695,000
Common dividends paid	(34,045,000)	(29,711,000)	(26,172,000)
Net cash provided by financing activities	109,881,000	158,880,000	213,509,000
Net increase (decrease) in cash and cash equivalents	(75,979,000)	13,330,000	97,511,000
Cash and cash equivalents at beginning of year	289,095,000	275,765,000	178,254,000
Cash and cash equivalents at end of period	213,116,000	289,095,000	275,765,000
Supplemental schedule of noncash investing and financing activities
Interest on deposits and borrowings	18,626,000	18,963,000	20,773,000
Income taxes	32,865,000	33,473,000	11,841,000
Transfer of loans to other real estate owned and foreclosed assets	511,000	1,322,000	1,522,000
Real Estate Owned, Transfer to Real Estate Owned			142,000
Capital commitment relating to Low Income Housing Project investments, noncash	20,000	5,180,000	1,658,000
In conjunction with the Company's acquisitions, assets were acquired and liabilities were assumed as follows
Common stock issued for acquisition	23,468,000	40,730,000	86,415,000
Fair value of assets acquired, net of cash acquired	179,252,000	266,242,000	598,376,000
Fair value of liabilities assumed	$ 162,073,000	$ 234,180,000	$ 498,513,000

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Operations Independent Bank Corp. (the “Company”) is a bank holding company whose principal subsidiary is Rockland Trust Company (“Rockland Trust” or the “Bank”). Rockland Trust is a state-chartered commercial bank, which operates eighty-four full service and two limited service retail branches, thirteen commercial banking centers, six investment management offices and one mortgage lending center, all of which are located in Eastern Massachusetts, including Cape Cod and Martha's Vineyard, with the exception of an investment management group/commercial lending office located in Providence, Rhode Island. Rockland Trust deposits are insured by the Federal Deposit Insurance Corporation, subject to regulatory limits. The Company’s primary source of income is from providing loans to individuals and small-to-medium sized businesses in its market area. Rockland Trust is a community-oriented commercial bank, and the community banking business is the Company's only reportable operating segment. Principles of Consolidation The consolidated financial statements include the accounts of the Company, the Bank and other wholly-owned subsidiaries, except subsidiaries that are not deemed necessary to be consolidated. All significant intercompany balances and transactions have been eliminated in consolidation. The Company determines whether it has a controlling financial interest in an entity by first evaluating whether the entity is a voting interest entity or a variable interest entity under GAAP. Voting interest entities are entities in which the total equity investment at risk is sufficient to enable the entity to finance itself independently and provides the equity holders with the obligation to absorb losses, the right to receive residual returns and the right to make decisions about the entity’s activities. The Company would consolidate voting interest entities in which it has all, or at least a majority of, the voting interest. As defined in applicable accounting standards, variable interest entities (“VIEs”) are entities that lack one or more of the characteristics of a voting interest entity. A controlling financial interest in a VIE is present when the Company has both the power and ability to direct the activities of the VIE that most significantly impact the VIE's economic performance and an obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The Company also owns the common stock of various trusts which have issued trust preferred securities. These trusts are VIEs in which the Company is not the primary beneficiary and, therefore, are not consolidated. The trust's only assets are junior subordinated debentures issued by the Company, which were acquired by the trust using the proceeds from the issuance of the trust preferred securities and common stock. The junior subordinated debentures are included in long-term debt and the Company’s equity interest in the trust is included in other assets in the accompanying Consolidated Balance Sheets. Interest expense on the junior subordinated debentures is reported in interest expense on long-term debt in the accompanying Consolidated Statements of Income. Reclassification Certain previously reported amounts have been reclassified to conform to the current year’s presentation. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could vary from these estimates. Material estimates that are particularly susceptible to significant changes in the near-term relate to the determination of the allowance for loan losses, income taxes, valuation and potential impairment of investment securities, other-than-temporary impairment (“OTTI”) of certain investment securities, as well as valuation of goodwill and other intangibles and their respective analyses of impairment. Significant Concentrations of Credit Risk The vast majority of the Bank’s lending activities are conducted in the Commonwealth of Massachusetts and Rhode Island. The Bank originates commercial and industrial loans, commercial and residential real estate loans, including construction loans, small business loans, home equity loans, and other consumer loans for its portfolio. The Bank considers a concentration of credit to a particular industry to exist when the aggregate credit exposure which includes direct, indirect or contingent obligations to a borrower, an affiliated group of borrowers or a nonaffiliated group of borrowers engaged in one industry, exceeds 10% of the Bank’s loan portfolio. Loans originated by the Bank to lessors of nonresidential buildings represented 15.4% of the total loan portfolio at both December 31, 2017 and 2016 , respectively. Within this concentration category, the Company believes it is well diversified among collateral property types and tenant industries. Cash and Cash Equivalents For purposes of reporting cash flows, cash and cash equivalents may include cash on hand, amounts due from banks, inclusive of interest-earning deposits held at banks, and federal funds sold. Generally, federal funds are sold for up to two week periods. Securities Investment securities are classified at the time of purchase as “available for sale,” “held to maturity,” or “trading.” Classification is constantly re-evaluated for consistency with corporate goals and objectives. Trading securities are recorded at fair value with subsequent changes in fair value recorded in earnings. Debt securities that management has the positive intent and ability to hold to maturity are classified as “held to maturity” and recorded at amortized cost. Securities not classified as held to maturity or trading, including equity securities with readily determinable fair values, are classified as “available for sale” and recorded at fair value, with changes in fair value excluded from earnings and reported in other comprehensive income, net of related tax. Purchase premiums and discounts are recognized in interest income, using the interest method, to arrive at periodic interest income at a constant effective yield, thereby reflecting the securities market yield. Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method. Declines in the fair value of held to maturity and available for sale securities below their amortized cost deemed to be OTTI are written down to fair value as determined by a cash flow analysis. To the extent the estimated cash flows do not support the amortized cost, the deficiency is considered to be due to credit loss and recognized in earnings. Unless the Company intends to sell the security, or if it is more likely than not that the Company will be required to sell the debt security before its anticipated recovery, the remainder of the OTTI charge is considered to be due to other factors, such as liquidity or interest rates, and thus is not recognized in earnings, but rather through other comprehensive income, net of related tax. The Company evaluates individual securities that have fair values below cost for six months or longer, or for a shorter period of time if considered appropriate by management, to determine if the decline in fair value is other-than-temporary. Consideration is given to the obligor of the security, whether the security is guaranteed, whether there is a projected adverse change in cash flows, the liquidity of the security, the type of security, the capital position of security issuers, and payment history of the security, amongst other factors when evaluating such securities. Loans Held for Sale The Bank primarily classifies new residential real estate mortgage loans as held for sale based on intent, which is determined when loans are underwritten. Residential real estate mortgage loans not designated as held for sale are retained based upon available liquidity, for interest rate risk management and other business purposes. The Company has elected the fair value option to account for originated closed loans intended for sale. Accordingly, changes in fair value relating to loans intended for sale are recorded in earnings and are offset by changes in fair value relating to interest rate lock commitments and forward sales commitments. Gains and losses on residential loan sales (sales proceeds minus carrying amount) are recorded in mortgage banking income. Upfront costs and fees related to items for which the fair value option is elected are recognized in earnings as incurred and are not deferred. Loans Loans are carried at the principal amounts outstanding, or amortized acquired fair value in the case of acquired loans, adjusted by partial charge-offs and net of deferred loan costs or fees. For originated loans, loan fees and certain direct origination costs are deferred and amortized into interest income over the expected term of the loan using the level-yield method. When a loan is paid off, the unamortized portion is recognized in interest income. Interest income on loans is accrued based upon the daily principal amount outstanding except for loans on nonaccrual status. For acquired loans which did not show signs of credit deterioration at acquisition, interest income is also accrued based upon the daily principal amount outstanding and is then further adjusted by the accretion of any discount or amortization of any premium associated with the loan. As a general rule, loans more than 90 days past due with respect to principal or interest are classified as nonaccrual loans, or sooner if management considers such action to be prudent. However, loans that are more than 90 days past due may be kept on an accruing status if the loan is well secured and in the process of collection. The Company may also put a junior lien mortgage on nonaccrual status as a result of delinquency with respect to the first position, which is held by the Bank or by another financial institution, while the junior lien is currently performing. Income accruals are suspended on all nonaccrual loans and all previously accrued and uncollected interest is reversed against current income. A loan remains on nonaccrual status until it becomes current with respect to principal and interest (and in certain instances remains current for up to six months), the loan is liquidated, or when the loan is determined to be uncollectible and is charged-off against the allowance for loan losses. When doubt exists as to the collectability of a loan, any payments received are applied to reduce the recorded investment in the asset to the extent necessary to eliminate such doubt. For all loan portfolios, a charge-off occurs when the Company determines that a specific loan, or portion thereof, is uncollectible. This determination is made based on management's review of specific facts and circumstances of the individual loan, including assessing the viability of the customer’s business or project as a going concern, the expected cash flows to repay the loan, the value of the collateral and the ability and willingness of any guarantors to perform. In cases where a borrower experiences financial difficulties and the Company makes certain concessionary modifications to contractual terms, the loan is classified as a troubled debt restructuring (“TDR”). Modifications may include adjustments to interest rates, extensions of maturity, consumer loans where the borrower's obligations have been effectively discharged through Chapter 7 Bankruptcy and the borrower has not reaffirmed the debt to the Bank, and other actions intended to minimize economic loss and avoid foreclosure or repossession of collateral. The recorded investment of loans classified as TDRs is adjusted to reflect the changes in value, if any, resulting from the granting of a concession. Nonaccrual loans that are restructured remain on nonaccrual for a period of six months to demonstrate that the borrower can meet the restructured terms. If the restructured loan is on accrual status prior to being modified, it is reviewed to determine if the modified loan should remain on accrual status. If the borrower’s ability to meet the revised payment schedule is not reasonably assured, the loan is classified as a nonaccrual loan. Loans classified as TDRs remain classified as such for the life of the loan, except in limited circumstances, when it is determined that the borrower is performing under the modified terms and the restructuring agreement specified an interest rate greater than or equal to an acceptable market rate for a comparable new loan at the time of the restructuring. Acquired loans All acquired loans are recorded at fair value with no carryover of the allowance for loan losses. At acquisition, loans are also reviewed to determine if the loan has evidence of deterioration in credit quality and to review if it is probable, at acquisition, that all contractually required payments will not be collected. Such loans are deemed to be purchased credit impaired ("PCI") loans. Under the accounting model for PCI loans, the excess of cash flows expected to be collected over the carrying amount of the loans, referred to as the "accretable yield", is accreted into interest income over the life of the loans using the effective yield method. Accordingly, PCI loans are not subject to classification as nonaccrual in the same manner as originated loans. Rather, acquired loans are generally considered to be accruing loans because their interest income relates to the accretable yield recognized and not to contractual interest payments at the loan level. The difference between contractually required principal and interest payments and the cash flows expected to be collected, referred to as the "nonaccretable difference", includes estimates of both the impact of prepayments and future credit losses expected to be incurred over the life of the loans. The estimate of cash flows expected to be collected is regularly re-assessed subsequent to acquisition. These re-assessments involve updates, as necessary, of the key assumptions and estimates used in the initial estimate of fair value. Generally speaking, expected cash flows are affected by: • Changes in the expected principal and interest payments over the estimated life - Changes in expected cash flows may be driven by the credit outlook and actions taken with borrowers. Changes in expected future cash flows resulting from loan modifications are included in the assessment of expected cash flows. • Change in prepayment assumptions - Prepayments affect the estimated life of the loans, which may change the amount of interest income expected to be collected. • Change in interest rate indices for variable rate loans - Expected future cash flows are based, as applicable, on the variable rates in effect at the time of the assessment of expected cash flows. A decrease in expected cash flows in subsequent periods may indicate that the loan is impaired which would likely require the recognition of a charge-off against the allowance for loan losses or an establishment of a specific reserve. An increase in expected cash flows in subsequent periods serves, first, to reduce any previously established specific reserve by the increase in the present value of cash flows expected to be collected. Any increase above the previously established specific reserve results in a recalculation of the amount of accretable yield for the loan. The adjustment of accretable yield due to an increase in expected cash flows is accounted for as a change in estimate. The additional cash flows expected to be collected are reclassified from the nonaccretable difference to the accretable yield, and the amount of periodic accretion is adjusted accordingly over the remaining life of the loans. A PCI loan may be resolved either through receipt of payment (in full or in part) from the borrower, the sale of the loan to a third party, or foreclosure of the collateral. In the event of a sale of the loan, a gain or loss on sale would be recognized and reported within noninterest income based on the difference between the sales proceeds and the carrying amount of the loan. For PCI loans accounted for on an individual loan basis and resolved directly with the borrower, any amount received from resolution in excess of the carrying amount of the loan is recognized and reported within interest income. A refinancing or modification of a PCI loan accounted for individually is assessed to determine whether the modification represents a TDR. If the loan is considered to be a TDR, it will be included in the total impaired loans reported by the Company. The loan will continue to recognize interest income based upon the excess of cash flows expected to be collected over the carrying amount of the loan. Allowance for Loan Losses The allowance for loan losses is established based upon the level of estimated probable losses in the current loan portfolio. Loan losses are charged against the allowance when management believes the collectability of a loan balance is doubtful. Subsequent recoveries, if any, are credited to the allowance. The allowance for loan losses is allocated to loan types using both a formula-based approach applied to groups of loans and an analysis of certain individual loans for impairment. The formula-based approach emphasizes loss factors derived from actual historical portfolio loss rates, which are combined with an assessment of certain qualitative factors to determine the allowance amounts allocated to the various loan categories. Allowance amounts are determined based on an estimate of the historical average annual percentage rate of loan loss for each loan category, an estimate of the incurred loss emergence and confirmation period for each loan category, and certain qualitative risk factors considered in the computation of the allowance for loan losses. The qualitative risk factors impacting the inherent risk of loss within the portfolio include the following: • National and local economic and business conditions • Level and trend of delinquencies • Level and trend of charge-offs and recoveries • Trends in volume and terms of loans • Risk selection, lending policy and underwriting standards • Experience and depth of management • Banking industry conditions and other external factors • Concentration risk The formula-based approach evaluates groups of loans with common characteristics, which consist of similar loan types with similar terms and conditions, to determine the appropriate allocation within each portfolio section. This approach incorporates qualitative adjustments based upon management’s assessment of various market and portfolio specific risk factors into its formula-based estimate. Due to the imprecise nature of the loan loss estimation process and ever changing conditions, the qualitative risk attributes may not adequately capture amounts of incurred loss in the formula-based loan loss components used to determine the Bank’s analysis of the appropriateness of the allowance for loan losses. The Bank evaluates certain loans within the commercial and industrial, commercial real estate, commercial construction and small business portfolios individually for specific impairment. A loan is considered impaired when, based on current information and events, it is probable that the Bank will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, contractual interest rates and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Loans are selected for evaluation based upon a change in internal risk rating, occurrence of delinquency, loan classification, troubled debt restructuring or nonaccrual status. A specific allowance amount is allocated to an individual loan when such loan has been deemed impaired and when the amount of the probable loss is able to be estimated. Estimates of loss may be determined by the present value of anticipated future cash flows, the loan’s observable fair market value, or the fair value of the collateral, if the loan is collateral dependent. However, for collateral dependent loans, the amount of the recorded investment in a loan that exceeds the fair value of the collateral less costs to sell is charged-off against the allowance for loan losses in lieu of an allocation of a specific allowance amount when such an amount has been identified definitively as uncollectible. Large groups of small-balance homogeneous loans such as the residential real estate, residential construction, home equity and other consumer portfolios are collectively evaluated for impairment. As such, the Bank does not typically identify individual loans within these groupings as impaired loans for impairment evaluation and disclosure. However, the Bank evaluates all TDRs for impairment on an individual loan basis regardless of loan type. In the ordinary course of business, the Bank enters into commitments to extend credit, commercial letters of credit, and standby letters of credit. Such financial instruments are recorded in the financial statements when they become payable. The credit risk associated with these commitments is evaluated in a manner similar to the allowance for loan losses. The reserve for unfunded lending commitments is included in other liabilities in the balance sheet. At December 31, 2017 and 2016 , the reserve for unfunded loan commitments was $972,000 and $954,000 , respectively. Transfers and Servicing of Financial Assets Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from the Company, (2) the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (3) the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. Loans held for sale are generally sold with servicing rights released, however if rights are retained, servicing assets are recognized as separate assets. Servicing rights are originally recorded at fair value within other assets, but subsequently are amortized in proportion to and over the period of estimated net servicing income, and are assessed for impairment at each reporting date. Fair value is based on market prices for comparable mortgage servicing contracts, when available, or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income. The valuation model incorporates assumptions that market participants would use in estimating future net servicing income, such as the cost to service, the discount rate, the custodial earnings rate, an inflation rate, ancillary income, prepayment speeds, default rates and losses. Impairment is determined by stratifying the rights based on predominant characteristics, such as interest rate, loan type and investor type. Impairment is recognized through a valuation allowance, to the extent that fair value is less than the capitalized amount. If the Company later determines that all or a portion of the impairment no longer exists, a reduction of the allowance may be recorded as an increase to income. Servicing fee income is recorded for fees earned for servicing loans for investors. The fees are based on a contractual percentage of the outstanding principal or a fixed amount per loan, and are recorded as income when earned. The amortization of mortgage servicing rights is recorded as a reduction of loan servicing fee income. Federal Home Loan Bank Stock The Company, as a member of the Federal Home Loan Bank (“FHLB”) of Boston, is required to maintain an investment in capital stock of the FHLB. Based on redemption provisions, the stock has no quoted market value and is carried at cost. The Company continually reviews its investment to determine if OTTI exists. The Company reviews recent public filings, rating agency analysis and other factors, when making its determination. Bank Premises and Equipment Land is carried at cost. Bank premises and equipment are stated at cost less accumulated depreciation. Depreciation is computed using the straight-line convention method over the estimated useful lives of the assets. Leasehold improvements are amortized over the shorter of the lease terms or the estimated useful lives of the improvements. Expected terms include lease option periods to the extent that the exercise of such options is reasonably assured, not to exceed fifteen years. Goodwill and Other Intangible Assets Goodwill represents the excess of the purchase price over the net fair value of acquired businesses. Goodwill is not amortized and is assigned to one reporting unit. Goodwill is evaluated for impairment at least annually, or more often if warranted, using a combined qualitative and quantitative impairment approach. The initial qualitative approach assesses whether the existence of events or circumstances led to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events and circumstances, the Company determines it is more likely than not that the fair value is less than carrying value, the two step quantitative impairment test is performed. Step one of the quantitative impairment test compares book value to the fair value of the reporting unit. If step one is failed, a detailed step two analysis is performed, which involves measuring the excess of the fair value of the reporting unit, as determined in step one, over the aggregate fair value of the individual assets, liabilities, and identifiable intangibles as if the reporting unit was being acquired in a business combination. Other intangible assets subject to amortization consist of core deposit intangibles, noncompete agreements, customer lists and market-based favorable or unfavorable lease positions at time of acquisition, and are amortized over the estimated lives of the intangibles using a method that approximates the amount of economic benefits that are realized by the Company. Other intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. The range of useful lives is as follows: Core deposit intangibles 10 years Noncompete agreements 1-3 years Leases 3-29 years The determination of which intangible assets have finite lives is subjective, as is the determination of the amortization period for such intangible assets. Impairment of Long-Lived Assets Other Than Goodwill The Company reviews long-lived assets, including premises and equipment, for impairment whenever events or changes in business circumstances indicate that the remaining useful life may warrant revision or that the carrying amount of the long-lived asset may not be fully recoverable. The Company performs undiscounted cash flow analysis to determine if impairment exists. 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. Cash Surrender Value of Life Insurance Policies Increases in the cash surrender value (“CSV”) of life insurance policies, as well as benefits received net of any CSV, are recorded in other noninterest income, and are not subject to income taxes. The CSV of the policies is recorded as an asset of the Bank, with liabilities recognized for any split dollar arrangements associated with the policies. The Company reviews the financial strength of the insurance carriers prior to the purchase of life insurance policies and no less than annually thereafter. Regulatory requirements limit the total amount of CSV to be held with any individual carrier to 15% of Tier 1 capital (as defined for regulatory purposes) and the total CSV of all life insurance policies is limited to 25% of Tier 1 capital. Other Real Estate Owned and Other Foreclosed Assets Real estate properties and other assets, which have served as collateral to secure loans, are held for sale and are initially recorded at fair value less estimated costs to sell at the date control is established, resulting in a new cost basis. The amount by which the recorded investment in the loan exceeds the fair value (net of estimated costs to sell) of the foreclosed asset is charged to the allowance for loan losses. Subsequent declines in the fair value of the foreclosed asset below the new cost basis are recorded through the use of a valuation allowance. Subsequent increases in the fair value are recorded as reductions in the valuation allowance, but not below zero. Upon a sale of a foreclosed asset, any excess of the carrying value over the sale proceeds is recognized as a loss on sale. Any excess of sale proceeds over the carrying value of the foreclosed asset is first applied as a recovery to the valuation allowance, if any, with the remainder being recognized as a gain on sale. Operating expenses and changes in the valuation allowance relating to foreclosed assets are included in other noninterest expense. Customer Repurchase Agreements In a security repurchase agreement transaction, the Company will generally sell a security, agreeing to repurchase either the same or substantially identical security on a specified later date, at a greater price than the original sales price. The difference between the sale price and purchase price is the cost of the proceeds, which is recorded as interest expense. The securities underlying the agreements are delivered to counterparties as security for the repurchase obligations. Since the securities are treated as collateral and the agreement does not qualify for a full transfer of effective control, the transactions do not meet the criteria to be classified as a sale, and are therefore considered a secured borrowing transaction for accounting purposes. Derivatives Derivative instruments are carried at fair value in the Company’s financial statements. The accounting for changes in the fair value of a derivative instrument is determined by whether it has been designated and qualifies as part of a hedging relationship, and further, by the type of hedging relationship. At the inception of a hedge, the Company documents certain items, including but not limited to the following: the relationship between hedging instruments and hedged items, the Company's risk management objectives, hedging strategies, and the evaluation of hedge transaction effectiveness. Documentation includes linking all derivatives designated as fair value or cash flow hedges to specific assets and liabilities on the balance sheet or to specific forecasted transactions. For those derivative instruments that are designated and qualify for special hedge accounting, the Company designates the hedging instrument, based upon the exposure being hedged, as either a fair value hedge or a cash flow hedge. For derivative instruments that are designated and qualify as a cash flow hedge (i.e., hedging the exposure to variability in expected future cash flows that is attributable to a particular risk), the effective portion of the gain or loss on the derivative instrument is reported as a component of other comprehensive income, net of related tax, and reclassified into earnings in the same period or periods during which the hedged transactions affect earnings. The remaining gain or loss on the derivative instrument in excess of the cumulative change in the present value of future cash flows of the hedged item (i.e., the ineffective portion), if any, is recognized in current earnings during the period. For derivative instruments designated and qualifying as a fair value hedge (i.e., hedging the exposure to changes in the fair value of an asset or liability or an identified portion thereof that is attribu

ACQUISITIONS

ACQUISITIONS	12 Months Ended
	Dec. 31, 2017
Business Acquisition [Line Items]
ACQUISITIONS	ACQUISITIONS Island Bancorp, Inc. On May 12, 2017, the Company completed its acquisition of Island Bancorp, Inc., the parent of The Edgartown National Bank ("Island Bancorp"). The transaction qualified as a tax-free reorganization for federal income tax purposes and Island Bancorp shareholders received, for each share of Island Bancorp common stock, the right to receive either $500 in cash per share or 9.525 shares of the Company's stock (valued at $605.31 per share, based upon the highest trading value of the Company's stock on May 12, 2017 of $63.55 ). The total deal consideration was $28.3 million and was comprised of 20% cash and 80% stock consideration. The cash consideration was $4.8 million in the aggregate, inclusive of cash paid in lieu of fractional shares. The total stock consideration was $23.5 million resulting in an increase to the Company's outstanding shares of 369,286 shares. In addition to increasing its loan and deposit base, the Company will be able to provide a deeper product set to new customers, as well as benefit from increased operating synergies, improving the long-term operating and financial results of the Company. The Company accounted for the Island Bancorp acquisition using the acquisition method pursuant to the Business Combinations Topic of the FASB ASC. Accordingly, the Company recorded merger and acquisition expenses of $3.2 million for the year ended December 31, 2017 related to the Island Bancorp acquisition. Additionally, the acquisition method requires the acquirer to recognize the assets acquired and the liabilities assumed at their fair values as of the acquisition date. The following table summarizes the estimated fair value of the assets acquired and liabilities assumed as of the date of the acquisition: Net Assets Acquired at Fair Value (Dollars in thousands) Assets Cash $ 11,137 Loans 155,551 Premises and equipment 5,828 Goodwill 10,280 Core deposit and other intangibles 2,964 Other assets 4,629 Total assets acquired 190,389 Liabilities Deposits 159,580 Borrowings 2,475 Other liabilities 18 Total liabilities assumed 162,073 Purchase price $ 28,316 Fair value adjustments to assets acquired and liabilities assumed are generally amortized using either an effective yield or straight-line basis over periods consistent with the average life, useful life and/or contractual term of the related assets and liabilities. Fair values of the major categories of assets acquired and liabilities assumed were determined as follows: Cash and Cash Equivalents The fair values of cash and cash equivalents approximate the respective carrying amounts because the instruments are payable on demand or have short-term maturities. Loans The loans acquired were recorded at fair value without a carryover of the allowance for loan losses. Fair value of the loans is determined using market participant assumptions in estimating the amount and timing of both principal and interest cash flows expected to be collected, as adjusted for an estimate of future credit losses and prepayments, and then applying a market-based discount rate to those cash flows. The overall discount on the loans acquired in this transaction was due to anticipated credit loss, as well as considerations for liquidity and market interest rates. In addition, the acquired loans were reviewed to determine if the loan had evidence of deterioration of credit quality at the purchase date and also reviewed to determine if it was probable that all contractually required payments will not be collected. Based on the review of the loan portfolio at the time of the acquisition, it was deemed that there was no evidence to show that any of the acquired loans were purchased credit impaired. Premises and Equipment The fair value of the premises, including land, buildings and improvements, was determined based upon appraisals by licensed real estate appraisers. The appraisals were based upon the best and highest use of the property with final values determined based upon an analysis of the cost, sales comparison and income capitalization approaches for each property appraised. Core Deposit Intangible The fair value of the core deposit intangible is derived by comparing the interest rate and servicing costs that the financial institution pays on the core deposit liability versus the current market rate for alternative sources of financing, while factoring in estimates over the remaining life and attrition rate of the deposit accounts. The intangible asset represents the stable and relatively low cost source of funds that the deposits and accompanying relationships provide the Company, when compared to alternative funding sources. Deposits The fair value of acquired savings and transaction deposit accounts was assumed to approximate the carrying value as these accounts have no stated maturity and are payable on demand. The fair value of time deposits were determined based on the present value of the contractual cash flows over the remaining period to maturity using a market interest rate. Borrowings The fair values of Federal Home Loan Bank ("FHLB") advances were derived based upon the present value of the principal and interest payments using a current market discount rate. Selected Pro Forma Results The following summarizes the unaudited pro forma results of operations as if the Company acquired Island Bancorp on January 1, 2017 (2016 amounts represent combined results for the Company and Island Bancorp). The selected pro forma financial information is presented for illustrative purposes only and is not necessarily indicative of the financial results of the combined companies had the acquisition actually been completed at the beginning of the periods presented, nor does it indicate future results for any other interim or full-year period. Years Ended December 31 2017 2016 (Dollars in thousands) Net interest income after provision for loan losses $ 258,017 $ 227,429 Net income 90,025 78,150 Excluded from the pro forma results of operations for the year ended December 31, 2017 are merger-related costs of $2.6 million , net of tax, recognized by both the Company and Island Bancorp in the aggregate. These costs were primarily made up of contract terminations arising due to the change in control, the acceleration of certain compensation and benefit costs, and other merger expenses. New England Bancorp, Inc. On November 10, 2016, the Company completed its acquisition of New England Bancorp, Inc. ("NEB"), the parent of Bank of Cape Cod. The transaction qualified as a tax-free reorganization for federal income tax purposes and NEB shareholders received, for each share of NEB common stock, the right to receive 0.25 shares of the Company's stock (valued at $15.14 per share, based upon the highest trading value of the Company's stock on November 10, 2016 of $60.55 ). The deal consideration was $41.7 million in the aggregate, inclusive of cash paid in lieu of fractional shares and resulted in an increase to the Company's outstanding shares of 672,665 shares. In addition to increasing its loan and deposit base, the Company will be able to provide a deeper product set to new customers, as well as benefit from increased operating synergies, improving the long-term operating and financial results of the Company. The Company accounted for the NEB acquisition using the acquisition method pursuant to the Business Combinations Topic of the FASB ASC. Accordingly, the Company recorded merger and acquisition expenses of $5.0 million , during the year ended December 31, 2016, related to the NEB transaction. Additionally, the acquisition method requires the acquirer to recognize the assets acquired and the liabilities assumed at their fair values as of the acquisition date. The following table summarizes the estimated fair value of the assets acquired and liabilities assumed as of the date of the acquisition: Net Assets Acquired at Fair Value (Dollars in thousands) Assets Cash $ 9,679 Loans 225,731 Premises and equipment 201 Goodwill 20,443 Core deposit and other intangibles 670 Other assets 19,197 Total assets acquired 275,921 Liabilities Deposits 175,686 Borrowings 51,150 Other liabilities 7,344 Total liabilities assumed 234,180 Purchase price $ 41,741 Fair value adjustments to assets acquired and liabilities assumed are generally amortized using either an effective yield or straight-line basis over periods consistent with the average life, useful life and/or contractual term of the related assets and liabilities. Fair values of the major categories of assets acquired and liabilities assumed were determined as follows: Cash and Cash Equivalents The fair values of cash and cash equivalents approximate the respective carrying amounts because the instruments are payable on demand or have short-term maturities. Loans The loans acquired were recorded at fair value without a carryover of the allowance for loan losses. Fair value of the loans is determined using market participant assumptions in estimating the amount and timing of both principal and interest cash flows expected to be collected, as adjusted for an estimate of future credit losses and prepayments, and then applying a market-based discount rate to those cash flows. The overall discount on the loans acquired in this transaction was due to estimated credit risk, as well as considerations for liquidity and market interest rates. In addition, the acquired loans were reviewed to determine if the loan had evidence of deterioration of credit quality at the purchase date and also reviewed to determine if it was probable that all contractually required payments will not be collected. Based on the review of the loan portfolio at the time of the acquisition it was deemed that there was no evidence to show that any of the acquired loans were purchased credit impaired. Core Deposit Intangible The fair value of the core deposit intangible is derived by comparing the interest rate and servicing costs that the financial institution pays on the core deposit liability versus the current market rate for alternative sources of financing, while factoring in estimates over the remaining life and attrition rate of the deposit accounts. The intangible asset represents the stable and relatively low cost source of funds that the deposits and accompanying relationships provide the Company, when compared to alternative funding sources. Deposits The fair value of acquired savings and transaction deposit accounts was assumed to approximate the carrying value as these accounts have no stated maturity and are payable on demand. The fair value of time deposits were determined based on the present value of the contractual cash flows over the remaining period to maturity using a market interest rate. Borrowings The fair values of FHLB advances were derived based upon the present value of the principal and interest payments using a current market discount rate. Subsequent to the acquisition, the Company paid off all acquired borrowings at their recognized fair value amounts, resulting in no gain or loss on extinguishment. Selected Pro Forma Results The following summarizes the unaudited pro forma results of operations as if the Company acquired NEB on January 1, 2016 (2015 amounts represent combined results for the Company and NEB). The selected pro forma financial information is presented for illustrative purposes only and is not necessarily indicative of the financial results of the combined companies had the acquisition actually been completed at the beginning of the periods presented, nor does it indicate future results for any other interim or full-year period. Years Ended December 31 2016 2015 (Dollars in thousands) Net interest income after provision for loan losses $ 228,927 $ 221,252 Net income $ 80,411 $ 65,623 Excluded from the pro forma results of operations for the year ended December 31, 2016 are merger-related costs of $6.3 million recognized by both the Company and NEB in the aggregate and the corresponding tax benefit. These costs were primarily made up of contract terminations arising due to the change in control, the acceleration of certain compensation and benefit costs, and other merger expenses.

SECURITIES

SECURITIES	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
SECURITIES	Trading Securities As of December 31, 2017 and December 31, 2016 the Company had trading securities of $1.3 million and $804,000 , respectively. These securities are held in a rabbi trust and will be used for future payments associated with the Company's non-qualified 401(k) Restoration Plan and Non-qualified Deferred Compensation Plan. Available for Sale and Held to Maturity Securities The following table presents a summary of the amortized cost, gross unrealized holding gains and losses and fair value of securities available for sale and securities held to maturity for the periods indicated: December 31, 2017 December 31, 2016 Amortized Gross Gross Unrealized Fair Amortized Gross Gross Unrealized Fair (Dollars in thousands) Available for sale securities U.S. government agency securities $ 35,475 $ 86 $ (131 ) $ 35,430 $ 24,006 $ 238 $ — $ 24,244 Agency mortgage-backed securities 214,934 1,897 (1,067 ) 215,764 173,268 2,852 (736 ) 175,384 Agency collateralized mortgage obligations 124,098 78 (2,164 ) 122,012 101,094 106 (1,332 ) 99,868 State, county, and municipal securities 2,237 37 — 2,274 3,743 50 — 3,793 Single issuer trust preferred securities issued by banks 2,012 4 — 2,016 2,311 3 (3 ) 2,311 Pooled trust preferred securities issued by banks and insurers 2,179 — (539 ) 1,640 2,200 — (616 ) 1,584 Small business administration pooled securities 47,852 44 (118 ) 47,778 37,561 — (372 ) 37,189 Equity securities 19,432 1,594 (442 ) 20,584 19,183 641 (553 ) 19,271 Total available for sale securities 448,219 3,740 (4,461 ) 447,498 363,366 3,890 (3,612 ) 363,644 Held to maturity securities U.S. treasury securities 1,006 29 — 1,035 1,007 47 — 1,054 Agency mortgage-backed securities 204,768 1,791 (736 ) 205,823 156,088 2,274 (858 ) 157,504 Agency collateralized mortgage obligations 262,998 397 (4,987 ) 258,408 297,445 1,002 (3,797 ) 294,650 Single issuer trust preferred securities issued by banks 1,500 29 — 1,529 1,500 44 — 1,544 Small business administration pooled securities 27,416 183 (200 ) 27,399 31,036 189 (327 ) 30,898 Total held to maturity securities 497,688 2,429 (5,923 ) 494,194 487,076 3,556 (4,982 ) 485,650 Total $ 945,907 $ 6,169 $ (10,384 ) $ 941,692 $ 850,442 $ 7,446 $ (8,594 ) $ 849,294 When securities are sold, the adjusted cost of the specific security sold is used to compute the gain or loss on the sale. The actual maturities of certain securities may differ from the contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. A schedule of the contractual maturities of securities available for sale and securities held to maturity as of December 31, 2017 is presented below: Available for Sale Held to Maturity Amortized Fair Amortized Fair (Dollars in thousands) Due in one year or less $ 3,213 $ 3,215 $ — $ — Due after one year to five years 49,241 49,312 15,636 15,711 Due after five to ten years 107,417 107,402 16,801 17,098 Due after ten years 268,916 266,985 465,251 461,385 Total debt securities 428,787 426,914 497,688 494,194 Equity securities 19,432 20,584 — — Total $ 448,219 $ 447,498 $ 497,688 $ 494,194 Inclusive in the table above is $9.4 million of callable securities at December 31, 2017 . The carrying value of securities pledged to secure public funds, trust deposits, repurchase agreements and for other purposes, as required or permitted by law, was $547.2 million and $482.1 million at December 31, 2017 and 2016 , respectively. At December 31, 2017 and 2016 , the Company had no investments in obligations of individual states, counties, or municipalities, which exceeded 10% of stockholders’ equity . Other-Than-Temporary Impairment The Company continually reviews investment securities for the existence of OTTI, taking into consideration current market conditions, the extent and nature of changes in fair value, issuer rating changes and trends, the credit worthiness of the obligor of the security, volatility of earnings, current analysts’ evaluations, the Company’s intent to sell the security, whether it is more likely than not that the Company will be required to sell the debt security before its anticipated recovery, as well as other qualitative factors. The term “other-than-temporary” is not intended to indicate that the decline is permanent, but indicates that the prospects for a near-term recovery of value is not necessarily favorable, or that there is a lack of evidence to support a realizable value equal to or greater than the carrying value of the investment. The following tables show the gross unrealized losses and fair value of the Company’s investments in an unrealized loss position, which the Company has not deemed to be OTTI, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position: December 31, 2017 Less than 12 months 12 months or longer Total Description of securities # of Fair Value Unrealized Fair Unrealized Fair Value Unrealized (Dollars in thousands) U.S. government agency securities 4 $ 24,343 $ (131 ) $ — $ — $ 24,343 $ (131 ) Agency mortgage-backed securities 84 $ 235,411 $ (1,493 ) $ 14,886 $ (310 ) $ 250,297 $ (1,803 ) Agency collateralized mortgage obligations 42 178,142 (1,579 ) 159,506 (5,572 ) 337,648 (7,151 ) Pooled trust preferred securities issued by banks and insurers 1 — — 1,640 (539 ) 1,640 (539 ) Small business administration pooled securities 4 34,553 (223 ) 9,647 (95 ) 44,200 (318 ) Equity securities 28 3,290 (39 ) 7,619 (403 ) 10,909 (442 ) Total temporarily impaired securities 163 $ 475,739 $ (3,465 ) $ 193,298 $ (6,919 ) $ 669,037 $ (10,384 ) December 31, 2016 Less than 12 months 12 months or longer Total Description of securities # of Fair Value Unrealized Fair Unrealized Fair Value Unrealized (Dollars in thousands) Agency mortgage-backed securities 57 $ 137,949 $ (1,594 ) $ — $ — $ 137,949 $ (1,594 ) Agency collateralized mortgage obligations 32 243,051 (3,140 ) 47,403 (1,989 ) 290,454 (5,129 ) Single issuer trust preferred securities issued by banks and insurers 1 — — 1,036 (3 ) 1,036 (3 ) Pooled trust preferred securities issued by banks and insurers 1 — — 1,583 (616 ) 1,583 (616 ) Small business administration pooled securities 5 59,846 (699 ) — — 59,846 (699 ) Equity securities 25 3,625 (77 ) 6,334 (476 ) 9,959 (553 ) Total temporarily impaired securities 121 $ 444,471 $ (5,510 ) $ 56,356 $ (3,084 ) $ 500,827 $ (8,594 ) The Company does not intend to sell these investments and has determined based upon available evidence that it is more likely than not that the Company will not be required to sell the security before the recovery of its amortized cost basis. As a result, the Company does not consider these investments to be OTTI. The Company made this determination by reviewing various qualitative and quantitative factors regarding each investment category, such as current market conditions, extent and nature of changes in fair value, issuer rating changes and trends, volatility of earnings, and current analysts’ evaluations. As a result of the Company’s review of these qualitative and quantitative factors, the causes of the impairments listed in the table above by category are as follows at December 31, 2017 : • U.S. Government Agency Securities, Agency Mortgage-Backed Securities, Agency Collateralized Mortgage Obligations and Small Business Administration Pooled Securities: These portfolios have contractual terms that generally do not permit the issuer to settle the securities at a price less than the current par value of the investment. The decline in market value of these securities is attributable to changes in interest rates and not credit quality. Additionally, these securities are implicitly guaranteed by the U.S. Government or one of its agencies. • Pooled Trust Preferred Securities: This portfolio consists of one below investment grade security which is performing. The unrealized loss on this security is attributable to the illiquid nature of the trust preferred market in the current economic and regulatory environment. Management evaluates collateral credit and instrument structure, including current and expected deferral and default rates and timing. In addition, discount rates are determined by evaluating comparable spreads observed currently in the market for similar instruments. • Equity Securities : This portfolio consists of mutual funds and other equity investments. During some periods, the mutual funds in the Company’s investment portfolio may have unrealized losses resulting from market fluctuations as well as the risk premium associated with that particular asset class. For example, emerging market equities tend to trade at a higher risk premium than U.S. government bonds and thus, will fluctuate to a greater degree on both the upside and the downside. In the context of a well-diversified portfolio, however, the correlation amongst the various asset classes represented by the funds serves to minimize downside risk. The Company evaluates each mutual fund in the portfolio regularly and measures performance on both an absolute and relative basis. A reasonable recovery period for positions with an unrealized loss is based on management’s assessment of general economic data, trends within a particular asset class, valuations, earnings forecasts and bond durations. The Company has the ability and intent to hold these equity securities until a recovery of fair value. There was no OTTI recorded for the years ended December 31, 2017 , 2016 or 2015 . Additionally, there was no cumulative credit related component of OTTI as of December 31, 2017 , 2016 and 2015 , as securities with $10.0 million of cumulative credit related OTTI were sold during 2015.

LOANS, ALLOWANCE FOR LOAN LOSSE

LOANS, ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY	12 Months Ended
	Dec. 31, 2017
Loans, Allowance for Loan Losses and Credit Quality [Abstract]
LOANS, ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY	LOANS, ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY Allowance for Loan Losses The following table summarizes changes in the allowance for loan losses by loan category and bifurcates the amount of allowance allocated to each loan category based on collective impairment analysis and loans evaluated individually for impairment: December 31, 2017 Commercial Commercial Commercial Small Residential Home Other Consumer Total (Dollars in thousands) Allowance for loan losses Beginning balance $ 16,921 $ 30,369 $ 4,522 $ 1,502 $ 2,621 $ 5,238 $ 393 $ 61,566 Charge-offs (3,891 ) (39 ) — (302 ) (207 ) (276 ) (1,494 ) (6,209 ) Recoveries 615 385 — 114 31 198 993 2,336 Provision (benefit) (389 ) 738 1,176 263 377 230 555 2,950 Ending balance $ 13,256 $ 31,453 $ 5,698 $ 1,577 $ 2,822 $ 5,390 $ 447 $ 60,643 Ending balance: collectively evaluated for impairment $ 13,246 $ 31,411 $ 5,698 $ 1,576 $ 1,815 $ 5,125 $ 430 $ 59,301 Ending balance: individually evaluated for impairment $ 10 $ 42 $ — $ 1 $ 1,007 $ 265 $ 17 $ 1,342 Financing receivables ending balance: Collectively evaluated for impairment $ 853,885 $ 3,093,945 $ 401,797 $ 131,667 $ 733,809 $ 1,045,053 $ 9,573 $ 6,269,729 Individually evaluated for impairment 34,643 16,638 — 703 13,684 6,826 307 72,801 Purchased credit impaired loans — 5,978 — — 6,836 209 — 13,023 Total loans by group $ 888,528 $ 3,116,561 $ 401,797 $ 132,370 $ 754,329 $ 1,052,088 $ 9,880 $ 6,355,553 (1) December 31, 2016 Commercial Commercial Commercial Small Residential Home Other Consumer Total (Dollars in thousands) Allowance for loan losses Beginning balance $ 13,802 $ 27,327 $ 5,366 $ 1,264 $ 2,590 $ 4,889 $ 587 $ 55,825 Charge-offs (593 ) (414 ) — (228 ) (28 ) (602 ) (1,607 ) (3,472 ) Recoveries 859 564 — 195 299 141 1,080 3,138 Provision (benefit) 2,853 2,892 (844 ) 271 (240 ) 810 333 6,075 Ending balance $ 16,921 $ 30,369 $ 4,522 $ 1,502 $ 2,621 $ 5,238 $ 393 $ 61,566 Ending balance: collectively evaluated for impairment $ 13,260 $ 30,173 $ 4,522 $ 1,494 $ 1,535 $ 4,996 $ 372 $ 56,352 Ending balance: individually evaluated for impairment $ 3,661 $ 196 $ — $ 8 $ 1,086 $ 242 $ 21 $ 5,214 Financing receivables ending balance: Collectively evaluated for impairment $ 862,875 $ 2,983,642 $ 320,391 $ 121,855 $ 622,392 $ 982,095 $ 10,666 $ 5,903,916 Individually evaluated for impairment 39,178 16,813 — 871 14,175 5,863 397 77,297 Purchased credit impaired loans — 10,343 — — 7,859 189 1 18,392 Total loans by group $ 902,053 $ 3,010,798 $ 320,391 $ 122,726 $ 644,426 $ 988,147 $ 11,064 $ 5,999,605 (1) December 31, 2015 Commercial Commercial Commercial Small Residential Other Consumer Total (Dollars in thousands) Allowance for loan losses Beginning balance $ 15,573 $ 25,873 $ 3,945 $ 1,171 $ 2,834 $ 4,956 $ 748 $ 55,100 Charge-offs (2,010 ) (330 ) — (267 ) (285 ) (710 ) (1,316 ) (4,918 ) Recoveries 1,593 1,073 — 264 133 356 724 4,143 Provision (benefit) (1,354 ) 711 1,421 96 (92 ) 287 431 1,500 Ending balance $ 13,802 $ 27,327 $ 5,366 $ 1,264 $ 2,590 $ 4,889 $ 587 $ 55,825 Ending balance: collectively evaluated for impairment $ 13,619 $ 27,123 $ 5,366 $ 1,260 $ 1,312 $ 4,651 $ 564 $ 53,895 Ending balance: individually evaluated for impairment $ 183 $ 204 $ — $ 4 $ 1,278 $ 238 $ 23 $ 1,930 Financing receivables ending balance: Collectively evaluated for impairment $ 838,129 $ 2,619,294 $ 373,064 $ 95,225 $ 614,014 $ 921,563 $ 14,427 $ 5,475,716 Individually evaluated for impairment 5,147 22,986 304 1,021 15,405 5,989 558 51,410 Purchase credit impaired loans — 11,154 — — 9,187 251 3 20,595 Total loans by group $ 843,276 $ 2,653,434 $ 373,368 $ 96,246 $ 638,606 $ 927,803 $ 14,988 $ 5,547,721 (1) (1) The amount of net deferred costs on originated loans included in the ending balance was $6.1 million , $5.1 million , and $4.3 million at December 31, 2017 , 2016 , and 2015 , respectively. Net unamortized discounts on acquired loans not deemed to be PCI included in the ending balance was $9.4 million , $8.6 million , and $6.6 million at December 31, 2017 , 2016 , and 2015 , respectively. For the purpose of estimating the allowance for loan losses, management segregates the loan portfolio into the portfolio segments detailed in the above tables. Each of these loan categories possesses unique risk characteristics that are considered when determining the appropriate level of allowance for each segment. Some of the risk characteristics unique to each loan category include: Commercial Portfolio • Commercial and Industrial : Loans in this category consist of revolving and term loan obligations extended to business and corporate enterprises for the purpose of financing working capital and/or capital investment. Collateral generally consists of pledges of business assets including, but not limited to: accounts receivable, inventory, plant and equipment, or real estate, if applicable. Repayment sources consist of primarily, operating cash flow, and secondarily, liquidation of assets. • Commercial Real Estate : Loans in this category consist of mortgage loans to finance investment in real property such as multi-family residential, commercial/retail, office, industrial, hotels, educational and healthcare facilities and other specific use properties. Loans are typically written with amortizing payment structures. Collateral values are determined based upon third party appraisals and evaluations. Loan to value ratios at origination are governed by established policy and regulatory guidelines. Repayment sources consist of, primarily, cash flow from operating leases and rents and, secondarily, liquidation of assets. • Commercial Construction : Loans in this category consist of short-term construction loans, revolving and nonrevolving credit lines and construction/permanent loans to finance the acquisition, development and construction or rehabilitation of real property. Project types include residential 1-4 family, condominium and multi-family homes, commercial/retail, office, industrial, hotels, educational and healthcare facilities and other specific use properties. Loans may be written with nonamortizing or hybrid payment structures depending upon the type of project. Collateral values are determined based upon third party appraisals and evaluations. Loan to value ratios at origination are governed by established policy and regulatory guidelines. Repayment sources vary depending upon the type of project and may consist of sale or lease of units, operating cash flows or liquidation of other assets. • Small Business: Loans in this category consist of revolving, term loan and mortgage obligations extended to sole proprietors and small businesses for purposes of financing working capital and/or capital investment. Collateral generally consists of pledges of business assets including, but not limited to, accounts receivable, inventory, plant and equipment, or real estate if applicable. Repayment sources consist primarily of operating cash flows and, secondarily, liquidation of assets. For the commercial portfolio it is the Company’s policy to obtain personal guarantees for payment from individuals holding material ownership interests of the borrowing entities. Consumer Portfolio • Residential Real Estate : Residential mortgage loans held in the Company’s portfolio are made to borrowers who demonstrate the ability to make scheduled payments with full consideration to underwriting factors such as current and expected income, employment status, current assets, other financial resources, credit history and the value of the collateral. Collateral consists of mortgage liens on 1-4 family residential properties. Residential mortgage loans also include loans to construct owner-occupied 1-4 family residential properties. • Home Equity : Home equity loans and credit lines are made to qualified individuals and are primarily secured by senior or junior mortgage liens on owner-occupied 1-4 family homes, condominiums or vacation homes. Each home equity loan has a fixed rate and is billed in equal payments comprised of principal and interest. Each home equity line of credit has a variable rate and is billed in interest-only payments during the draw period. At the end of the draw period, the home equity line of credit is billed as a percentage of the then outstanding principal balance plus all accrued interest over a predetermined repayment period, as set forth in the note. Additionally, the Company has the option of renewing each line of credit for additional draw periods. Borrower qualifications include favorable credit history combined with supportive income requirements and combined loan to value ratios within established policy guidelines. • Other Consumer: Other consumer loan products include personal lines of credit and amortizing loans made to qualified individuals for various purposes such as education, debt consolidation, personal expenses or overdraft protection. Borrower qualifications include favorable credit history combined with supportive income and collateral requirements within established policy guidelines. These loans may be secured or unsecured. Credit Quality The Company continually monitors the asset quality of the loan portfolio using all available information. Based on this information, loans demonstrating certain payment issues or other weaknesses may be categorized as adversely risk-rated, delinquent, impaired, nonperforming and/or put on nonaccrual status. Additionally, in the course of resolving such loans, the Company may choose to restructure the contractual terms of certain loans to match the borrower’s ability to repay the loan based on their current financial condition. If a restructured loan meets certain criteria, it may be categorized as a troubled debt restructuring (“TDR”). The Company reviews numerous credit quality indicators when assessing the risk in its loan portfolio. For the commercial portfolio, the Company utilizes a 10-point credit risk-rating system, which assigns a risk-grade to each loan obligation based on a number of quantitative and qualitative factors associated with a commercial or small business loan transaction. Factors considered include industry and market conditions, position within the industry, earnings trends, operating cash flow, asset/liability values, debt capacity, guarantor strength, management and controls, financial reporting, collateral, and other considerations. The risk-ratings categories are defined as follows: • 1- 6 Rating — Pass: Risk-rating grades “1” through “6” comprise those loans ranging from ‘Substantially Risk Free’ which indicates borrowers are of unquestioned credit standing and the pinnacle of credit quality, well established companies with a very strong financial condition, and loans fully secured by cash collateral, through ‘Acceptable Risk’, which indicates borrowers may exhibit declining earnings, strained cash flow, increasing or above average leverage and/or weakening market fundamentals that indicate below average asset quality, margins and market share. Collateral coverage is protective. • 7 Rating — Potential Weakness: Borrowers exhibit potential credit weaknesses or downward trends deserving management’s close attention. If not checked or corrected, these trends will weaken the Company’s asset and position. While potentially weak, currently these borrowers are marginally acceptable; no loss of principal or interest is envisioned. • 8 Rating — Definite Weakness Loss Unlikely: Borrowers exhibit well defined weaknesses that jeopardize the orderly liquidation of debt. Loan may be inadequately protected by the current net worth and paying capacity of the obligor or by the collateral pledged, if any. Normal repayment from the borrower is in jeopardy, although no loss of principal is envisioned. However, there is a distinct possibility that a partial loss of interest and/or principal will occur if the deficiencies are not corrected. Collateral coverage may be inadequate to cover the principal obligation. • 9 Rating — Partial Loss Probable: Borrowers exhibit well defined weaknesses that jeopardize the orderly liquidation of debt with the added provision that the weaknesses make collection of the debt in full, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. Serious problems exist to the point where partial loss of principal is likely. • 10 Rating — Definite Loss: Borrowers deemed incapable of repayment. Loans to such borrowers are considered uncollectible and of such little value that continuation as active assets of the Company is not warranted. The credit quality of the commercial loan portfolio is actively monitored and any changes in credit quality are reflected in risk-rating changes. Risk-ratings are assigned or reviewed for all new loans, when advancing significant additions to existing relationships (over $50,000 ), at least quarterly for all actively managed loans, and any time a significant event occurs, including at renewal of the loan. The Company utilizes a comprehensive strategy for monitoring commercial credit quality. Actively managed commercial borrowers are required to provide updated financial information at least annually which is carefully evaluated for any changes in credit quality. Larger loan relationships are subject to a full annual credit review by an experienced credit analysis group, while continuous portfolio monitoring techniques are employed to evaluate changes in credit quality for smaller loan relationships. Additionally, the Company retains an independent loan review firm to evaluate the credit quality of the commercial loan portfolio. The independent loan review process achieves significant penetration into the commercial loan portfolio and reports the results of these reviews to the Audit Committee of the Board of Directors on a quarterly basis. The following table details the amount of outstanding principal balances relative to each of the risk-rating categories for the Company’s commercial portfolio: December 31, 2017 Category Risk Commercial and Commercial Real Commercial Small Business Total (Dollars in thousands) Pass 1 - 6 $ 806,331 $ 3,007,672 $ 400,964 $ 130,265 $ 4,345,232 Potential weakness 7 16,563 69,788 — 1,471 87,822 Definite weakness - loss unlikely 8 59,415 38,637 833 631 99,516 Partial loss probable 9 6,219 464 — 3 6,686 Definite loss 10 — — — — — Total $ 888,528 $ 3,116,561 $ 401,797 $ 132,370 $ 4,539,256 December 31, 2016 Category Risk Commercial and Commercial Real Commercial Small Business Total (Dollars in thousands) Pass 1 - 6 $ 783,825 $ 2,876,570 $ 317,099 $ 120,304 $ 4,097,798 Potential weakness 7 46,176 84,641 1,363 1,859 134,039 Definite weakness - loss unlikely 8 71,991 47,164 1,929 556 121,640 Partial loss probable 9 61 2,423 — 7 2,491 Definite loss 10 — — — — — Total $ 902,053 $ 3,010,798 $ 320,391 $ 122,726 $ 4,355,968 For the Company’s consumer portfolio, the quality of the loan is best indicated by the repayment performance of an individual borrower. However, the Company does supplement performance data with current Fair Isaac Corporation (“FICO”) scores and Loan to Value (“LTV”) estimates. Current FICO data is purchased and appended to all consumer loans on a regular basis. In addition, automated valuation services and broker opinions of value are used to supplement original value data for the residential and home equity portfolios, periodically. The following table shows the weighted average FICO scores and the weighted average combined LTV ratios as of the periods indicated below: December 31 2017 2016 Residential portfolio FICO score (re-scored)(1) 745 743 LTV (re-valued)(2) 59.2 % 63.2 % Home equity portfolio FICO score (re-scored)(1) 766 767 LTV (re-valued)(2)(3) 50.1 % 55.9 % (1) The average FICO scores at December 31, 2017 are based upon rescores available from August 2017 and origination score data for loans booked between September and December 2017. The average FICO scores at December 31, 2016 are based upon rescores available from November 2016 and origination score data for loans booked in December 2016. (2) The combined LTV ratios for December 31, 2017 are based upon updated automated valuations as of August 2017, when available, and/or the most current valuation data available as of December 31, 2017. The combined LTV ratios for December 31, 2016 are based upon updated automated valuations as of March 2015, when available, and /or the most current valuation data for loans as of December 31, 2016. The updated automated valuations provides new information on loans that may be available since the previous valuation was obtained. If no new information is available, the valuation will default to the previously obtained data or most recent appraisal. (3) For home equity loans and lines in a subordinate lien, the LTV data represents a combined LTV, taking into account the senior lien data for loans and lines. Asset Quality The Bank’s philosophy toward managing its loan portfolios is predicated upon careful monitoring, which stresses early detection and response to delinquent and default situations. Delinquent loans are managed by a team of seasoned collection specialists and the Company seeks to make arrangements to resolve any delinquent or default situation over the shortest possible time frame. As a general rule, loans more than 90 days past due with respect to principal or interest are classified as nonaccrual loans. The Company also may use discretion regarding the accrual status of other loans over 90 days delinquent if the loan is well secured and in process of collection. The following table shows the carrying value of nonaccrual loans at the dates indicated: December 31 2017 2016 (Dollars in thousands) Commercial and industrial $ 32,055 $ 37,455 Commercial real estate 3,123 6,266 Small business 230 302 Residential real estate 8,129 7,782 Home equity 6,022 5,553 Other consumer 71 47 Total nonaccrual loans (1) $ 49,630 $ 57,405 (1) Included in these amounts were $6.1 million and $5.2 million of nonaccruing TDRs at December 31, 2017 and 2016 , respectively. The following table shows information regarding foreclosed residential real estate property at the date indicated: December 31, 2017 December 31, 2016 (Dollars in thousands) Foreclosed residential real estate property held by the creditor $ 612 $ 3,775 Recorded investment in mortgage loans collateralized by residential real estate property that are in the process of foreclosure $ 2,971 $ 1,715 The following table shows the age analysis of past due financing receivables as of the dates indicated: December 31, 2017 30-59 days 60-89 days 90 days or more Total Past Due Current Total Recorded Number Principal Number Principal Number Principal Number Principal (Dollars in thousands) Commercial and industrial 2 $ 195 2 $ 370 14 $ 32,007 18 $ 32,572 $ 855,956 $ 888,528 $ — Commercial real estate 7 3,060 — — 9 1,793 16 4,853 3,111,708 3,116,561 — Commercial construction — — — — — — — — 401,797 401,797 — Small business 17 339 11 144 10 57 38 540 131,830 132,370 — Residential real estate 6 870 13 2,385 22 3,471 41 6,726 747,603 754,329 — Home equity 22 1,310 6 451 20 2,025 48 3,786 1,048,302 1,052,088 — Other consumer (1) 265 197 16 27 17 45 298 269 9,611 9,880 8 Total 319 $ 5,971 48 $ 3,377 92 $ 39,398 459 $ 48,746 $ 6,306,807 $ 6,355,553 $ 8 December 31, 2016 30-59 days 60-89 days 90 days or more Total Past Due Current Total Recorded Number Principal Number Principal Number Principal Number Principal (Dollars in thousands) Commercial and industrial 8 $ 100 32 $ 253 6 $ 2,480 46 $ 2,833 $ 899,220 $ 902,053 $ — Commercial real estate 5 1,518 8 1,957 8 3,105 21 6,580 3,004,218 3,010,798 — Commercial construction — — — — — — — — 320,391 320,391 — Small business 9 323 — — 19 140 28 463 122,263 122,726 — Residential real estate 11 1,277 9 1,950 27 3,507 47 6,734 637,692 644,426 — Home equity 19 1,117 11 767 16 1,209 46 3,093 985,054 988,147 — Other consumer (1) 249 184 12 17 15 7 276 208 10,856 11,064 2 Total 301 $ 4,519 72 $ 4,944 91 $ 10,448 464 $ 19,911 $ 5,979,694 $ 5,999,605 $ 2 (1) Other consumer portfolio is inclusive of deposit account overdrafts recorded as loan balances. Troubled Debt Restructurings In the course of resolving nonperforming loans, the Bank may choose to restructure the contractual terms of certain loans. The Bank attempts to work out an alternative payment schedule with the borrower in order to avoid foreclosure actions. Any loans that are modified are reviewed by the Bank to identify if a TDR has occurred, which is when, for economic or legal reasons related to a borrower’s financial difficulties, the Bank grants a concession to the borrower that it would not otherwise consider. Terms may be modified to fit the ability of the borrower to repay in line with its current financial status and the restructuring of the loan may include the transfer of assets from the borrower to satisfy the debt, a modification of loan terms, or a combination of the two. The following table shows the Company’s total TDRs and other pertinent information as of the dates indicated: December 31 2017 2016 (Dollars in thousands) TDRs on accrual status $ 25,852 $ 27,093 TDRs on nonaccrual status 6,067 5,199 Total TDRs $ 31,919 $ 32,292 Amount of specific reserves included in the allowance for loan loss associated with TDRs: $ 1,342 $ 1,417 Additional commitments to lend to a borrower who has been a party to a TDR: $ 487 $ 1,378 The Company’s policy is to have any restructured loan which is on nonaccrual status prior to being modified remain on nonaccrual status for six months subsequent to being modified before management considers its return to accrual status. If the restructured loan is on accrual status prior to being modified, it is reviewed to determine if the modified loan should remain on accrual status. Additionally, loans classified as TDRs are adjusted to reflect the changes in value of the recorded investment in the loan, if any, resulting from the granting of a concession. For all residential loan modifications, the borrower must perform during a 90 day trial period before the modification is finalized. The following table shows the modifications which occurred during the periods indicated and the change in the recorded investment subsequent to the modifications occurring: Years Ended December 31 2017 Number Pre-Modification Post-Modification (Dollars in thousands) Troubled debt restructurings Commercial and industrial 12 $ 1,787 $ 1,787 Commercial real estate 6 2,705 2,705 Small business 9 369 369 Residential real estate 10 1,284 1,326 Home equity 17 1,985 1,988 Total 54 $ 8,130 $ 8,175 2016 Troubled debt restructurings Commercial and industrial 10 $ 1,623 $ 1,623 Commercial real estate 10 2,959 2,959 Small business 3 188 188 Residential real estate 8 1,808 1,850 Home equity 13 932 932 Other consumer 6 153 153 Total 50 $ 7,663 $ 7,705 2015 Troubled debt restructurings Commercial and industrial 13 $ 1,314 $ 1,314 Commercial real estate 6 2,941 2,941 Small business 9 293 293 Residential real estate 8 843 870 Home equity 8 694 694 Total 44 $ 6,085 $ 6,112 (1) The post-modification balances represent the legal principal balance of the loan on the date of modification. These amounts may show an increase when modifications include a capitalization of interest. The following table shows the Company’s post-modification balance of TDRs listed by type of modification as of the periods indicated: Years Ended December 31 2017 2016 2015 (Dollars in thousands) Extended maturity $ 5,881 $ 5,044 $ 2,936 Adjusted interest rate — 92 — Combination rate and maturity 568 1,035 2,199 Court ordered concession 1,726 1,534 977 Total $ 8,175 $ 7,705 $ 6,112 The Company considers a loan to have defaulted when it reaches 90 days past due. The following table shows loans that were modified during the prior twelve months and subsequently defaulted during the periods indicated: Years Ended December 31 2017 2016 2015 Number Recorded Number Recorded Number Recorded (Dollars in thousands) Troubled debt restructurings that subsequently defaulted Commercial & industrial 1 $ 122 — $ — 3 $ 339 Commercial real estate — — 1 249 1 502 Residential real estate — — — — 2 326 Home equity — — — — 1 100 Total 1 $ 122 1 $ 249 7 $ 1,267 All TDR loans are considered impaired and therefore are subject to a specific review for credit losses. The impairment analysis appropriately discounts the present value of the anticipated cash flows by the loan’s contractual rate of interest in effect prior to the loan’s modification. The amount of impairment, if any, is recorded as a specific loss allocation to each individual loan in the allowance for loan losses. Commercial loans (commercial and industrial, commercial construction, commercial real estate and small business loans), residential loans, and home equity loans that have been classified as TDRs and which subsequently default are reviewed to determine if the loan should be deemed collateral dependent. In such an instance, any shortfall between the value of the collateral and the carrying value of the loan is determined by measuring the recorded investment in the loan against the fair value of the collateral less costs to sell. The Company charges off the amount of any confirmed loan loss in the period when the loans, or portion of loans, are deemed uncollectible. Smaller balance consumer TDR loans are reviewed for performance to determine when a charge-off is appropriate. Impaired Loans A loan is considered impaired when, based on current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. The table below sets forth information regarding the Company’s impaired loans. The information for average recorded investment and interest income recognized is reflective of the full period being presented and does not take into account the date at which a loan was deemed to be impaired. See information below as of the dates indicated: As of and For the Years Ended December 31 2017 Recorded Unpaid Related Average Interest Income Recognized (Dollars in thousands) With no related allowance recorded Commercial and industrial $ 34,267 $ 38,329 $ — $ 36,631 $ 446 Commercial real estate 13,245 14,374 — 13,683 559 Small business 556 619 — 569 21 Residential real estate 4,264 4,397 — 4,332 218 Home equity 4,950 5,056 — 5,063 198 Other consumer 91 92 — 102 7 Subtotal 57,373 62,867 — 60,380 1,449 With an allowance recorded Commercial and industrial 376 376 10 391 19 Commercial real estate 3,393 3,399 42 3,447 198 Small business 147 153 1 238 14 Residential real estate 9,420 10,154 1,007 9,575 284 Home equity 1,876 2,110 265 1,916 55 Other consumer 216 217 17 233 7 Subtotal 15,428 16,409 1,342 15,800 577 Total $ 72,801 $ 79,276 $ 1,342 $ 76,180 $ 2,026 2016 Recorded Unpaid Related Average Interest (Dollars in thousands) With no related allowance recorded Commercial and industrial $ 28,776 $ 29,772 $ — $ 26,472 $ 927 Commercial real estate 11,628 12,891 — 12,744 437 Small business 494 569 — 534 20 Residential real estate 4,216 4,427 — 4,302 185 Home equity 4,485 4,572 — 4,602 184 Other consumer 146 146 — 160 11 Subtotal 49,745 52,377 — 48,814 1,764 With an allowance recorded Commercial and industrial 10,402 10,440 3,661 10,760 325 Commercial real estate 5,185 5,533 196 5,491 200 Small business 377 392 8 408 21 Residential real estate 9,959 10,530 1,086 10,065 332 Home equity 1,378 1,547 242 1,403 50 Other consumer 251 252 21 268 8 Subtotal 27,552 28,694 5,214 28,395 936 Total $ 77,297 $ 81,071 $ 5,214 $ 77,209 $ 2,700 2015 Recorded Unpaid Related Average Interest (Dollars in thousands) With no related allowance recorded Commercial and industrial $ 2,613 $ 3,002 $ — $ 3,024 $ 71 Commercial real estate 12,008 13,128 — 11,676 375 Commercial construction 304 305 — 308 — Small business 527 618 — 584 22 Residential real estate 3,874 4,033 — 3,958 157 Home equity 4,893 5,005 — 5,023 195 Other consumer 184 185 — 201 15 Subtotal 24,403 26,276 — 24,774 835 With an allowance recorded Commercial and industrial 2,534 2,648 183 2,848 48 Commercial real estate 10,978 11,047 204 10,789 592 Small business 494 523 4 535 30 Residential real estate 11,531 12,652 1,278 11,669 460 Home equity 1,096 1,287 238 655 14 Other consumer 374 389 23 408 14 Subtotal 27,007 28,546 1,930 26,904 1,158 Total $ 51,410 $ 54,822 $ 1,930 $ 51,678 $ 1,993 Purchased Credit Impaired Loans Certain loans acquired by the Company may have shown evidence of deterioration of credit quality since origination and it was deemed unlikely that the Company would be able to collect all contractually required payments. As such, these loans were deemed to be PCI loans and the carrying value and prospective income recognition are predicated upon future cash flows expected to be collected. The following table displays certain information pertaining to PCI loans at the dates indicated: December 31 2017 2016 (Dollars in thousands) Outstanding balance $ 14,485 $ 20,477 Carrying amount $ 13,023 $ 18,392 The following table summarizes activity in the accretable yield for the PCI loan portfolio: 2017 2016 (Dollars in thousands) Beginning balance $ 2,370 $ 2,827 Accretion (1,475 ) (1,540 ) Other change in expected cash flows (1) 748 953 Reclassification from nonaccretable difference for loans which have paid off (2) 148 130 Ending balance $ 1,791 $ 2,370 (1) Represents changes in cash flows expected to be collected resulting in increased interest income as a prospective yield adjustment over the remaining life of the loan(s). (2) Results in increased income during the period when a loan pays off at amount greater than originally expected.

BANK PREMISES AND EQUIPMENT

BANK PREMISES AND EQUIPMENT	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
BANK PREMISES AND EQUIPMENT	Bank premises and equipment at December 31, were as follows: 2017 2016 Estimated (Dollars in thousands) (In years) Cost Land $ 23,719 $ 20,585 n/a Bank premises 49,159 43,553 5-40 Leasehold improvements 25,184 24,387 1-27 Furniture and equipment 62,521 58,237 1-12 Leased equipment 10,644 — 7 Total cost 171,227 146,762 Accumulated depreciation (76,505 ) (68,282 ) Net bank premises and equipment $ 94,722 $ 78,480 Depreciation expense related to bank premises and equipment was $8.5 million in 2017 , $7.3 million in 2016 , and $7.0 million in 2015 , which is primarily included in occupancy and equipment expenses. Depreciation expense relating to computer software is included within other noninterest expense. During 2017, the Company purchased equipment that was subject to a master lease agreement with a third party lessee. As such, the Company assumed the role of lessor in conjunction with the purchase, which was deemed to be an operating lease for accounting purposes. The Company purchased a total of $10.6 million of equipment subject to the lease agreement in 2017. In addition, the Company recognized rental income of $1.3 million for the year ended December 31, 2017, as well as depreciation expense of $939,000 , which is included in the totals above.

GOODWILL AND IDENTIFIABLE INTAN

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS	GOODWILL AND OTHER INTANGIBLE ASSETS The following table sets forth the carrying value of goodwill and other intangible assets, net of accumulated amortization, at December 31: 2017 2016 (Dollars in thousands) Balances not subject to amortization Goodwill $ 231,806 $ 221,526 Balances subject to amortization Core deposit intangibles 8,636 8,527 Other intangible assets 705 1,321 Total other intangible assets 9,341 9,848 Total goodwill and other intangible assets $ 241,147 $ 231,374 The changes in the carrying value of goodwill for the periods indicated were as follows: 2017 2016 (Dollars in thousands) Balance at beginning of year $ 221,526 $ 201,083 Acquisitions 10,280 20,443 Balance at end of year $ 231,806 $ 221,526 The gross carrying amount and accumulated amortization of other intangible assets were as follows at the dates indicated: December 31 2017 2016 Gross Accumulated Net Gross Accumulated Net (Dollars in thousands) Core deposit intangibles $ 26,736 $ (18,100 ) $ 8,636 $ 23,917 $ (15,390 ) $ 8,527 Other intangible assets 3,165 (2,460 ) 705 3,020 (1,699 ) 1,321 Total $ 29,901 $ (20,560 ) $ 9,341 $ 26,937 $ (17,089 ) $ 9,848 Amortization of intangible assets was $3.5 million for 2017 and $2.8 million for both 2016 and 2015 . The following table sets forth the estimated annual amortization expense of intangible assets for each of the next five years: Year Amount (Dollars in thousands) 2018 $ 2,394 2019 $ 1,687 2020 $ 1,414 2021 $ 1,245 2022 $ 948 The original weighted average amortization period for intangible assets is 9.8 years .

DEPOSITS

DEPOSITS	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
DEPOSITS	DEPOSITS The following is a summary of the scheduled maturities of time deposits as of December 31: 2017 2016 (Dollars in thousands) 1 year or less $ 393,452 61.1 % $ 430,834 66.4 % Over 1 year to 2 years 119,341 18.5 % 82,627 12.7 % Over 2 years to 3 years 57,619 8.9 % 44,190 6.8 % Over 3 years to 4 years 41,183 6.4 % 49,446 7.6 % Over 4 years to 5 years 32,706 5.1 % 42,055 6.5 % Total $ 644,301 100.0 % $ 649,152 100.0 % The amount of overdraft deposits that were reclassified to the loan category were $2.3 million at both December 31, 2017 and 2016 . The Company has pledged assets as collateral covering certain deposits in the amount of $349.2 million and $299.7 million at December 31, 2017 and 2016 , respectively. The Bank's deposit accounts are insured to the maximum extent permitted by law by the Deposit Insurance Fund which is administered by the FDIC. The FDIC offers insurance coverage on deposits up to the federally insured limit of $250,000. The amount of time deposit accounts equal to or greater than $250,000 as of December 31, 2017 and 2016 is $80.0 million and $75.3 million , respectively.

BORROWINGS

BORROWINGS	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
BORROWINGS	BORROWINGS Federal Home Loan Bank Borrowings Advances payable to the Federal Home Loan Bank as of December 31 are summarized as follows: 2017 2016 Weighted Weighted Average Average Total Contractual Total Contractual Outstanding Rate Outstanding Rate (Dollars in thousands) Stated Maturity 2017 $ — — % $ 50,000 2.43 % 2018 52,475 1.58 % — — % Subtotal 52,475 1.58 % 50,000 2.43 % Amortizing advances 789 819 Total Federal Home Loan Bank Advances $ 53,264 $ 50,819 To manage the interest rate risk of these advances, the Company may enter into interest rate swap agreements which effectively fix the rate of the borrowing. Inclusive of the impact of these swap arrangements, the weighted average rate of the FHLB borrowings was 2.47% and 3.42% at December 31, 2017 and 2016 , respectively. During 2016, exclusive of the impact from the NEB acquisition, the Company repaid $49.0 million of FHLB borrowings prior to the maturity date of the borrowings. This prepayment resulted in a loss on extinguishment of debt of $437,000 . The Company also repaid $13.0 million of FHLB borrowings in 2015, resulting in a loss on extinguishment of debt of $122,000 . There were no prepayments made during 2017. The Company’s FHLB advances are collateralized by a blanket pledge agreement on the Bank’s FHLB stock, certain qualified investment securities, deposits at the FHLB, and by residential mortgages, and certain commercial real estate loans held in the Bank’s portfolio. The carrying value of the loans pledged as collateral for these borrowings totaled $1.5 billion and $1.4 billion at December 31, 2017 and 2016 , respectively. The Bank’s unused remaining available borrowing capacity at the FHLB was approximately $954.8 million and $793.1 million at December 31, 2017 and 2016 , respectively, inclusive of a $5.0 million line of credit. At December 31, 2017 and 2016 , the Company had sufficient collateral at the FHLB to support its obligations and was in compliance with the FHLB's collateral pledging program. Short-Term Debt The Company’s short-term borrowings consist of customer repurchase agreements, and amounted to $162.7 million and $176.9 million at December 31, 2017 and 2016 , respectively. The interest expense on short-term borrowings was $257,000 , $208,000 , and $210,000 for the years ended December 31, 2017 , 2016 , and 2015 , respectively. Customer Repurchase Agreements . The Company can raise additional liquidity by entering into repurchase agreements at its discretion. These repurchases are accounted for as a secured borrowing transaction for accounting purposes. Payments on such borrowings are interest only until the scheduled repurchase date. In a repurchase agreement the Company is subject to the risk that the purchaser may default at maturity and not return the securities underlying the agreements. In order to minimize this potential risk, the Company enters into repurchase agreements that stipulate that the securities underlying the agreement are not delivered to the customer and instead are held in segregated safekeeping accounts by the Company's safekeeping agents. The table below sets forth the remaining contractual maturity of the Company’s repurchase agreements allocated by source of collateral at the dates indicated: December 31 2017 2016 (Dollars in thousands) Sources of Collateral U.S. government agency securities $ 16,867 $ 20,233 Agency mortgage-backed securities 51,273 79,079 Agency collateralized mortgage obligations 94,539 77,601 Total customer repurchase agreements (1) $ 162,679 $ 176,913 (1) All customer repurchase agreements have an overnight and continuous maturity date. For further information regarding the Company's repurchase agreements see Note 12 , Balance Sheet Offsetting . Long-Term Debt The following table summarizes long-term debt, net of debt issuances costs, as of the periods indicated: December 31 2017 2016 (Dollars in thousands) Junior subordinated debentures Capital Trust V $ 51,503 $ 51,500 Slades Ferry Trust I 10,229 10,224 Central Trust I 5,258 5,302 Central Trust II 6,083 6,081 Subordinated debentures 34,682 34,635 Total long-term debt $ 107,755 $ 107,742 The interest expense on long-term debt was $4.0 million , $5.8 million , and $6.6 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively. Junior Subordinated Debentures : The junior subordinated debentures are issued to various trust subsidiaries of the Company. These trusts are considered to be variable interest entities for which the Company is not the primary beneficiary, and therefore the accounts of the trusts are not included in the Company’s consolidated financial statements. These trusts were formed for the purpose of issuing trust preferred securities, which were then sold in a private placement offering. The proceeds from the sale of the securities and the issuance of common stock by these trusts were invested in these Junior Subordinated Debentures issued by the Company. For regulatory purposes, bank holding companies are allowed to include trust preferred securities in Tier 1 capital up to a certain limit. Provisions in the Dodd-Frank Act generally exclude trust preferred securities from Tier 1 capital, however, holding companies with consolidated assets of less than $15 billion, such as the Company, are able to continue to include these instruments in Tier 1 capital, but no such securities issued in the future will count as Tier 1 capital. Information relating to these trust preferred securities are as follows: Trust Description of Capital Securities Capital Trust V $50.0 million due in 2037, interest at a variable rate of 3 month LIBOR plus 1.48% (3.07% at December 31, 2017),which, effective on January 17, 2017, has been converted to a fixed rate of 2.84% through the use of an interest rate swap. Prior to 2017, this borrowing had been converted to a fixed rate of 6.52%, through the use of an interest rate swap which expired on December 28, 2016. These securities are callable quarterly, until maturity. Slades Ferry Trust I $10.0 million due in 2034, bearing interest at a variable rate of 3 month LIBOR plus 2.79% (4.39% at December 31, 2017). These securities are callable quarterly, until maturity. Central Trust I $5.1 million due in 2034, bearing interest at a variable rate of 3 month LIBOR plus 2.44% (4.03% at December 31, 2017). These securities are callable quarterly, until maturity. Central Trust II $5.9 million due in 2037, bearing interest at a variable rate of 3 month LIBOR plus 1.65% (3.24% at December 31, 2017), beginning in March of 2017. Previously, the interest was at a fixed rate of 7.015%. These securities are callable quarterly, until maturity. All obligations under these trust preferred securities are unconditionally guaranteed by the Company. Subordinated Debentures : At December 31, 2017 and 2016 there was $35.0 million of outstanding principal amount subordinated debentures at the bank holding company. The subordinated debentures were issued to several investors via private placement on November 17, 2014. The subordinated debt matures on November 15, 2024, however with regulatory approval, the Bank may redeem the subordinated debt without penalty at any scheduled payment date on or after November 15, 2019 with 30 days notice. The interest rate is fixed at 4.75% through November 15, 2019, after which it converts to LIBOR plus 2.98% . The following table sets forth the contractual maturities of long-term debt over the next five years: 2018 2019 2020 2021 2022 Thereafter Total (Dollars in thousands) Junior subordinated debentures Capital trust V $ — $ — $ — $ — $ — $ 51,547 $ 51,547 Slades ferry trust I — — — — — 10,310 10,310 Central trust I — — — — — 5,258 5,258 Central trust II — — — — — 6,083 6,083 Subordinated debentures — — — — — 35,000 35,000 Total $ — $ — $ — $ — $ — $ 108,198 $ 108,198

EARNINGS PER SHARE

EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
EARNINGS PER SHARE	Earnings per share consisted of the following components for the years ended December 31: 2017 2016 2015 (Dollars in thousands, except per share data) Net income $ 87,204 $ 76,648 $ 64,960 Weighted Average Shares Basic shares 27,294,028 26,404,071 25,891,382 Effect of dilutive securities 78,076 51,847 68,566 Diluted shares 27,372,104 26,455,918 25,959,948 Net income per share Basic EPS $ 3.19 $ 2.90 $ 2.51 Effect of dilutive securities — — (0.01 ) Diluted EPS $ 3.19 $ 2.90 $ 2.50 For the year ended December 31, 2017 there were 103 options to purchase common stock and no shares of performance-based restricted stock that were excluded from the calculation of diluted earnings per share because they were anti-dilutive. There were no options to purchase common stock or shares of performance-based restricted stock that were considered anti-dilutive for the years ended December 31, 2016 and 2015 .

STOCK BASED COMPENSATION

STOCK BASED COMPENSATION	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK BASED COMPENSATION	The Company's stock based plans include the Second Amended and Restated 2005 Employee Stock Plan (“2005 Plan”) and the 2010 Nonemployee Director Stock Plan (“2010 Plan”) both of which have been approved by the Company’s Board of Directors and shareholders. The Company may award shares from these plans as either stock options or restricted stock from its pool of authorized but unissued shares. The following table presents the amount of cumulatively granted stock options and restricted stock awards, net of forfeitures, through December 31, 2017 : Authorized Awards Cumulative Granted, Net of Total Authorized Stock Restricted 2005 Plan 1,650,000 537,941 695,546 1,233,487 416,513 2010 Plan 314,600 42,000 93,245 135,245 179,355 The following table presents the pre-tax expense associated with stock option and restricted stock awards and the related tax benefits recognized for the years presented: Years Ended December 31 2017 2016 2015 (Dollars in thousands) Stock based compensation expense Restricted stock awards(1) $ 2,730 $ 2,590 $ 2,296 Directors’ fee expense Stock options 76 72 — Restricted stock awards 527 303 194 Total stock based award expense $ 3,333 $ 2,965 $ 2,490 Related tax benefits recognized in earnings $ 1,362 $ 1,211 $ 1,122 (1) Inclusive of compensation expense associated with time-vested and performance-based restricted stock awards. Expense related to awards issued to directors are recognized as directors’ fees within other noninterest expense. The Company has standard form agreements used for stock option and restricted stock awards. The standard form agreements used for the Chief Executive Officer and all other Executive Officers have previously been disclosed in Securities and Exchange Commission filings and generally provide that: (1) any unvested options or unvested restricted stock vest upon a Change of Control; and, that (2) any stock options which vest pursuant to a Change of Control, which is an event described in Section 280G of the Internal Revenue Code of 1986, will be cashed out at the difference between the acquisition price and the exercise price of the stock option. Stock Options The fair value of each option grant is estimated on the date of the grant using the Black-Scholes option-pricing model with the following assumptions used for grants under the identified plans: • Expected volatility is based on the standard deviation of the historical volatility of the weekly adjusted closing price of the Company’s shares for a period equivalent to the expected life of the option. • Expected life represents the period of time that the option is expected to be outstanding, taking into account the contractual term, historical exercise/forfeiture behavior, and the vesting period, if any. • Expected dividend yield is an annualized rate calculated using the most recent dividend payment at time of grant and the Company’s average trailing twelve-month daily closing stock price. • The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for a period equivalent to the expected life of the option. • Prior to January 1, 2017, the stock based compensation expense recognized in earnings was based on the amount of awards ultimately expected to vest, therefore a forfeiture assumption was estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differed from those estimates. Stock based compensation expense recognized was reduced for annualized estimated forfeitures of 4.5% in both 2016 and 2015 based on historical experience. Effective January 1, 2017, the Company adopted new accounting guidance and elected to no longer estimate forfeitures on stock compensation and instead recognize forfeitures when they occur. The election required a cumulative effect adjustment to retained earnings which did not materially impact the Company's consolidated financial position. The Company made the following awards of nonqualified options to purchase shares of common stock in 2017 and 2016 . There were no such awards made in 2015 . Years Ended December 31 2017 2016 Date of grant 11/7/2017 7/14/2016 2/20/2016 Plan 2010 2010 2010 Options granted 5,000 5,000 5,000 Vesting period (beginning on the grant date) 14 months 18 months 22 months Expiration date 11/7/2027 7/14/2026 2/20/2026 Expected volatility 20.80 % 32.28 % 32.44 % Expected life (years) 5.5 5.5 5.5 Expected dividend yield 1.87 % 2.37 % 2.28 % Risk free interest rate 2.02 % 1.14 % 1.29 % Fair value per option $ 12.43 $ 11.46 $ 10.59 Under all of the Company’s stock based plans, the option exercise price is based upon the average of the high and low trading value of the stock on the date of grant. Stock option awards granted to date under all plans expire through 2027 . The following table presents relevant information relating to the Company’s stock options for the periods indicated: Years Ended December 31 2017 2016 2015 (Dollars in thousands, except per share data) Fair value of stock options vested based on grant date fair value $ 72 $ 37 $ 14 Intrinsic value of stock options exercised $ 1,082 $ 494 $ 3,362 Cash received from stock option exercises $ 918 $ 680 $ 6,105 Tax benefit realized on stock option exercises/repurchase $ 442 $ 204 $ 1,362 Weighted average grant date fair value of options granted (per share) $ 12.43 $ 11.03 $ — A summary of stock option activity of the Company’s Stock Option Grants for the year ended December 31, 2017 is presented in the table below: Outstanding Nonvested Stock Option Weighted Weighted Aggregate Stock Weighted (Dollars in thousands, except per share data) Balance at January 1, 2017 109,650 $ 29.93 6,666 $ 11.03 Granted 5,000 70.28 5,000 12.43 Exercised (30,150 ) 30.43 — — Vested n/a n/a (6,667 ) 10.85 Forfeited — — — — Expired (500 ) 28.88 — — Balance at December 31, 2017 84,000 (2) $ 32.16 3.04 years $ 3,258 4,999 $ 12.11 Options outstanding and expected to vest at December 31, 2017 84,000 (3) $ 32.16 3.04 years $ 3,258 Options exercisable at December 31, 2017 79,001 (4) $ 30.21 2.64 years $ 3,218 Unrecognized compensation cost $ 22 Weighted average remaining recognition period (years) 1.00 (1) The aggregate intrinsic value in the preceding tables represents the total pre-tax intrinsic value, based on the average of the high price and low price at which the Company’s common stock traded on December 31, 2017 of $70.95 , which would have been received by the option holders had they all exercised their options as of that date. (2) Inclusive of 38,000 stock options outstanding to Directors. (3) Inclusive of 38,000 vested stock options and expected to vest to Directors. (4) Inclusive of 33,001 vested stock options outstanding to Directors. Restricted Stock The Company grants both time-vested restricted stock awards as well as performance-based restricted stock awards. During the years ended December 31, 2017 , 2016 , and 2015 the Company has made the following restricted stock award grants: Shares Granted Plan Fair Value (1) Vesting Period Time-vested 2017 2/13/2017 1,200 1,200 2005 $ 62.53 Ratably over 5 years from grant date 2/16/2017 34,150 34,150 2005 $ 63.10 Ratably over 5 years from grant date 3/31/2017 500 500 2005 $ 65.63 Ratably over 5 years from grant date 4/3/2017 1,500 1,500 2005 $ 64.14 Once on November 30, 2017 (2) 5/15/2017 1,000 1,000 2005 $ 64.03 Ratably over 5 years from grant date 5/23/2017 7,000 7,000 2010 $ 61.95 At the end of 5 years from grant date (3) 6/15/2017 950 950 2005 $ 66.18 Ratably over 5 years from grant date 2016 2/11/2016 51,475 2005 $ 41.96 Ratably over 5 years from grant date 3/1/2016 600 2005 $ 44.37 Ratably over 5 years from grant date 5/24/2016 8,700 2010 $ 48.34 At the end of 5 years from grant date (3) 9/19/2016 800 2005 $ 52.92 Ratably over 5 years from grant date 11/7/2016 500 2005 $ 54.28 Ratably over 5 years from grant date 11/14/2016 725 2010 $ 63.43 Once on May 24, 2021 (4) 2015 2/11/2015 31,500 2005 $ 39.42 Ratably over 5 years from grant date 2/12/2015 25,910 2005 $ 40.03 Ratably over 5 years from grant date 3/19/2015 3,800 2005 $ 43.56 Ratably over 5 years from grant date 4/27/2015 625 2005 $ 41.61 At the end of 3 years from grant date 4/27/2015 1,875 2005 $ 41.61 At the end of 5 years from grant date 5/27/2015 8,800 2010 $ 45.02 At the end of 5 years from grant date (3) 7/14/2015 800 2010 $ 47.82 Once on May 27, 2020 (5) 10/13/2015 1,000 2005 $ 46.09 Ratably over 5 years from grant date 10/20/2015 2,000 2005 $ 46.47 Ratably over 5 years from grant date Performance-based 2/16/2017 14,400 2005 $ 63.10 The earlier of: the date on which it is determined if the performance goal has been achieved; or, March 31, 2020. 2/11/2016 20,450 2005 $ 41.96 The earlier of: the date on which it is determined if the performance goal has been achieved; or, March 31, 2019. 2/12/2015 21,780 2005 $ 40.03 The earlier of: the date on which it is determined if the performance goal has been achieved; or, March 31, 2018. (1) The fair value of the restricted stock awards are based upon the average of the high and low prices at which the Company’s common stock traded on the date of grant. The holders of time-vested restricted stock awards participate fully in the rewards of stock ownership of the Company, including voting and dividend rights. The holders of performance-based restricted stock awards do not participate in the rewards of stock ownership of the Company until vested. The holders of all restricted stock awards are not required to pay any consideration to the Company for the awards. (2) This restricted stock grant fully vested upon an employee's termination, on November 30, 2017. (3) These restricted stock grants will vest at the end of a five year period, or earlier if the director ceases to be a director for any reason other than cause, such as, for example, by retirement. (4) These restricted stock grants will vest on May 24, 2021, or earlier if the director ceases to be a director for any reason other than cause, such as, for example, by retirement. (5) These restricted stock grants will vest on May 27, 2020, or earlier if the director ceases to be a director for any reason other than cause, such as, for example, by retirement. The following table presents the fair value of restricted stock awards vesting during the periods presented: Years Ended December 31 2017 2016 2015 (Dollars in thousands) Fair value of restricted stock awards upon vesting $ 5,717 $ 3,019 $ 2,610 A summary of the status of the Company’s Restricted Stock Award Grants for the year ended December 31, 2017 is presented in the table below: Outstanding Restricted Stock Weighted Average (Dollars in thousands, except per share data) Balance at January 1, 2017 264,315 $ 38.88 Granted 60,700 63.07 Vested/released (89,436 ) 36.79 Forfeited (9,614 ) 39.49 Balance at December 31, 2017 225,965 (1) $ 46.18 Unrecognized compensation cost (inclusive of directors’ fees) $ 6,355 Weighted average remaining recognition period (years) 3.00 (1) Inclusive of 38,445 restricted stock awards outstanding to Directors.

DERIVATIVES AND HEDGING ACTIVIT

DERIVATIVES AND HEDGING ACTIVITIES	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVES AND HEDGING ACTIVITIES	DERIVATIVES AND HEDGING ACTIVITIES The Company’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Company’s known or expected cash receipts and its known or expected cash payments principally to manage the Company’s interest rate risk. Additionally, the Company enters into interest rate derivatives and foreign exchange contracts to accommodate the business requirements of its customers (“customer related positions”). The Company minimizes the market and liquidity risks of customer related positions by entering into similar offsetting positions with broker-dealers. Derivative instruments are carried at fair value in the Company’s financial statements. The accounting for changes in the fair value of a derivative instrument is dependent upon whether or not it qualifies as a hedge for accounting purposes, and further, by the type of hedging relationship. The Company does not enter into proprietary trading positions for any derivatives. Interest Rate Positions The Company currently utilizes interest rate swap agreements as hedging instruments against interest rate risk associated with the Company’s borrowings. An interest rate swap is an agreement whereby one party agrees to pay a floating rate of interest on a notional principal amount in exchange for receiving a fixed rate of interest on the same notional amount, for a predetermined period of time, from a second party. The amounts relating to the notional principal amount are not actually exchanged. The maximum length of time over which the Company is currently hedging its exposure to the variability in future cash flows for forecasted transactions related to the payment of variable interest on existing financial instruments is five years. The following table reflects the Company’s derivative positions for the periods indicated below for interest rate swaps which qualify as cash flow hedges for accounting purposes: December 31, 2017 Notional Trade Effective Maturity Receive Current Pay Fixed Fair Value (Dollars in thousands) $ 25,000 9-Dec-08 10-Dec-08 10-Dec-18 3 Month LIBOR 1.54 % 2.94 % $ (264 ) 25,000 1-Apr-16 17-Jan-17 15-Dec-21 3 Month LIBOR 1.59 % 1.36 % 772 25,000 1-Apr-16 17-Jan-17 15-Dec-21 3 Month LIBOR 1.59 % 1.36 % 763 25,000 18-Jul-17 15-Aug-17 15-Aug-22 3 Month LIBOR 1.42 % 1.88 % 345 $ 100,000 $ 1,616 December 31, 2016 Notional Trade Effective Maturity Receive Current Pay Fixed Fair Value (Dollars in thousands) $ 25,000 9-Dec-08 10-Dec-08 10-Dec-18 3 Month LIBOR 0.95 % 2.94 % $ (740 ) 25,000 1-Apr-16 17-Jan-17 15-Dec-21 3 Month LIBOR N/A 1.36 % 689 25,000 1-Apr-16 17-Jan-17 15-Dec-21 3 Month LIBOR N/A 1.36 % 675 $ 75,000 $ 624 For derivative instruments that are designated and qualify as cash flow hedging instruments, the effective portion of the gains or losses is reported as a component of other comprehensive income ("OCI"), and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The Company expects approximately $202,000 (pre-tax) to be reclassified as an offset to interest expense from OCI, related to the Company’s cash flow hedges, in the next twelve months. This reclassification is due to anticipated payments that will be made and/or received on the swaps based upon the forward curve as of December 31, 2017 . The Company recognized $244,000 of net amortization income that was an offset to interest expense related to previously terminated swaps for the years ended December 31, 2017 , 2016 and 2015 . The Company had no fair value hedges during 2017 , 2016 and 2015 . Customer Related Positions Loan level derivatives, primarily interest rate swaps, offered to commercial borrowers through the Company’s loan level derivative program do not qualify as hedges for accounting purposes. The Company believes that its exposure to commercial customer derivatives is limited because these contracts are simultaneously matched at inception with an offsetting dealer transaction. The commercial customer derivative program allows the Company to retain variable-rate commercial loans while allowing the customer to synthetically fix the loan rate by entering into a variable-to-fixed interest rate swap. The amounts relating to the notional principal amount are not actually exchanged. Foreign exchange contracts offered to commercial borrowers through the Company’s derivative program do not qualify as hedges for accounting purposes. The Company acts as a seller and buyer of foreign exchange contracts to accommodate its customers. To mitigate the market and liquidity risk associated with these derivatives, the Company enters into similar offsetting positions. The amounts relating to the notional principal amount are exchanged. The following table reflects the Company’s customer related derivative positions for the periods indicated below for those derivatives not designated as hedging: Number of Notional Amount Maturing Less than 1 year Less than 2 years Less than 3 years Less than 4 years Thereafter Total Fair Value December 31, 2017 (Dollars in thousands) Loan level swaps Receive fixed, pay variable 246 $ 36,023 $ 61,500 $ 152,287 $ 111,147 $ 591,385 $ 952,342 $ 3,875 Pay fixed, receive variable 231 $ 36,023 $ 61,500 $ 152,287 $ 111,147 $ 591,385 $ 952,342 $ (3,880 ) Foreign exchange contracts Buys foreign currency, sells U.S. currency 15 $ 26,382 $ 3,780 $ — $ — $ — $ 30,162 $ 1,202 Buys U.S. currency, sells foreign currency 15 $ 26,382 $ 3,780 $ — $ — $ — $ 30,162 $ (1,188 ) December 31, 2016 (Dollars in thousands) Loan level swaps Receive fixed, pay variable 222 $ 30,245 $ 21,708 $ 63,771 $ 165,783 $ 567,897 $ 849,404 $ 12,005 Pay fixed, receive variable 207 $ 30,245 $ 21,708 $ 63,771 $ 165,783 567,897 $ 849,404 $ (12,008 ) Foreign exchange contracts Buys foreign currency, sells U.S. currency 33 $ 45,711 $ — $ — $ — $ — $ 45,711 $ (2,250 ) Buys U.S. currency, sells foreign currency 33 $ 45,711 $ — $ — $ — $ — $ 45,711 $ 2,277 (1) The Company may enter into one dealer swap agreement which offsets multiple commercial borrower swap agreements. Mortgage Derivatives Prior to closing and funding certain 1- 4 family residential mortgage loans, an interest rate lock commitment is generally extended to the borrower. During the period from commitment date to closing date, the Company is subject to the risk that market rates of interest may change. If market rates rise, investors generally will pay less to purchase such loans resulting in a reduction in the gain on sale of the loans or, possibly, a loss. In an effort to mitigate such risk, forward delivery sales commitments are executed, under which the Company agrees to deliver whole mortgage loans to various investors. These forward commitments carry a market price that has a strong inverse relationship to that of mortgage prices. Certain assumptions, including pull through rates and rate lock periods, are used in managing the existing and future economic hedges. The effectiveness of the economic hedges rely on the accuracy of these assumptions. The change in fair value on the interest rate lock commitments and forward delivery sale commitments are recorded in current period earnings as a component of mortgage banking income. In addition, the Company has elected the fair value option to carry loans held for sale at fair value. The change in fair value of loans held for sale is recorded in current period earnings as a component of mortgage banking income in accordance with the Company's fair value election. The change in fair value associated with loans held for sale was a decrease of $113,000 , an increase of $87,000 and a decrease of $22,000 for the years ended December 31 , 2017 , 2016 , and 2015 , respectively. These amounts were offset in earnings by the change in the fair value of mortgage derivatives. Additionally, the aggregate amount of net realized gains or losses on sales of such loans included within mortgage banking income amounted to $4.7 million , $6.1 million and $4.7 million for the years ended December 31 , 2017 , 2016 and 2015 , respectively. The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the balance sheet at the periods indicated: Asset Derivatives Liability Derivatives Fair Value at Fair Value at Fair Value at Fair Value at Balance Sheet December 31, 2017 December 31, 2016 Balance Sheet December 31, 2017 December 31, 2016 (Dollars in thousands) Derivatives designated as hedges Interest rate derivatives Other assets $ 1,880 $ 1,364 Other liabilities $ 264 $ 740 Derivatives not designated as hedges Customer Related Positions: Loan level derivatives Other assets 14,236 18,629 Other liabilities 14,241 18,632 Foreign exchange contracts Other assets 1,202 2,338 Other liabilities 1,188 2,311 Mortgage Derivatives Interest rate lock commitments Other assets 149 430 Other liabilities — — Forward sales agreements Other assets 9 — Other liabilities — 233 15,596 21,397 15,429 21,176 Total $ 17,476 $ 22,761 $ 15,693 $ 21,916 The table below presents the effect of the Company’s derivative financial instruments included in OCI and current earnings for the periods indicated: Years Ended December 31 2017 2016 2015 (Dollars in thousands) Derivatives designated as hedges Gain in OCI on derivatives (effective portion), net of tax $ 443 $ 2,170 $ 1,199 Loss reclassified from OCI into interest expense (effective portion) $ (441 ) $ (2,520 ) $ (2,828 ) Loss recognized in income on derivatives (ineffective portion and amount excluded from effectiveness testing) Interest expense $ — $ — $ — Other expense — — — Total $ — $ — $ — Derivatives not designated as hedges Changes in fair value of customer related positions Other income $ 6 $ 73 $ 60 Other expenses (21 ) (82 ) (53 ) Changes in fair value of mortgage derivatives Mortgage banking income (39 ) (35 ) (50 ) Total $ (54 ) $ (44 ) $ (43 ) The Company's derivative agreements with institutional counterparties contain various credit-risk related contingent provisions, such as requiring the Company to maintain a well-capitalized capital position. If the Company fails to meet these conditions, the counterparties could request the Company make immediate payment or demand that the Company provide immediate and ongoing full collateralization on derivative positions in net liability positions. The aggregate fair value of all derivative instruments with credit-risk related contingent features that were in a net liability position was $4.2 million and $12.8 million at December 31, 2017 and December 31, 2016 , respectively. Although none of the contingency provisions have applied as of December 31, 2017 and December 31, 2016 , the Company has posted collateral to offset the net liability exposure with institutional counterparties. By using derivatives, the Company is exposed to credit risk to the extent that counterparties to the derivative contracts do not perform as required. Should a counterparty fail to perform under the terms of a derivative contract, the Company’s credit exposure on interest rate swaps is limited to the net positive fair value and accrued interest of all swaps with each counterparty. The Company seeks to minimize counterparty credit risk through credit approvals, limits, monitoring procedures, and obtaining collateral, where appropriate. Institutional counterparties must have an investment grade credit rating and be approved by the Company’s Board of Directors. As such, management believes the risk of incurring credit losses on derivative contracts with those counterparties is remote. The Company's exposure relating to institutional counterparties was $7.1 million and $4.7 million at December 31, 2017 and 2016 , respectively. The Company’s exposure relating to customer counterparties was approximately $9.5 million and $16.1 million at December 31, 2017 and 2016 , respectively. Credit exposure may be reduced by the amount of collateral pledged by the counterparty.

BALANCE SHEET OFFSETTING

BALANCE SHEET OFFSETTING	12 Months Ended
	Dec. 31, 2017
Offsetting [Abstract]
Balance Sheet Offsetting Disclosure [Text Block]	BALANCE SHEET OFFSETTING The Company does not offset fair value amounts recognized for derivative instruments or repurchase agreements. The Company does net the amount recognized for the right to reclaim cash collateral against the obligation to return cash collateral arising from derivative instruments executed with the same counterparty under a master netting arrangement. Collateral legally required to be maintained at dealer banks by the Company is monitored and adjusted as necessary. The following tables present the Company's asset and liability derivative positions and the potential effect of netting arrangements on its financial position, as of the periods indicated: Gross Amounts Not Offset in the Statement of Financial Position Gross Amounts Recognized in the Statement of Financial Position Gross Amounts Offset in the Statement of Financial Position Net Amounts Presented in the Statement of Financial Position Financial Instruments (1) Collateral Pledged (Received) Net Amount December 31, 2017 (Dollars in thousands) Derivative Assets Interest rate swaps $ 1,880 $ — $ 1,880 $ 805 $ — $ 1,075 Loan level derivatives 14,236 — 14,236 4,578 — 9,658 Customer foreign exchange contracts 1,202 — 1,202 — — 1,202 $ 17,318 $ — $ 17,318 $ 5,383 $ — $ 11,935 Derivative Liabilities Interest rate swaps $ 264 $ — $ 264 $ — $ 264 $ — Loan level derivatives 14,241 — 14,241 5,383 3,675 5,183 Customer foreign exchange contracts 1,188 — 1,188 — — 1,188 $ 15,693 $ — $ 15,693 $ 5,383 $ 3,939 $ 6,371 Customer repurchase agreements $ 162,679 $ — $ 162,679 $ — $ 162,679 $ — (1) Reflects offsetting derivative positions with the same counterparty. Gross Amounts Not Offset in the Statement of Financial Position Gross Amounts Recognized in the Statement of Financial Position Gross Amounts Offset in the Statement of Financial Position Net Amounts Presented in the Statement of Financial Position Financial Instruments (1) Collateral Pledged (Received) Net Amount December 31, 2016 (Dollars in thousands) Derivative Assets Interest rate swaps $ 1,364 $ — $ 1,364 $ 961 $ — $ 403 Loan level derivatives 18,629 — 18,629 3,261 — 15,368 Customer foreign exchange contracts 2,338 — 2,338 — — 2,338 $ 22,331 $ — $ 22,331 $ 4,222 $ — $ 18,109 Derivative Liabilities Interest rate swaps $ 740 $ — $ 740 $ — $ 740 $ — Loan level derivatives 18,632 — 18,632 4,222 11,106 3,304 Customer foreign exchange contracts 2,311 — 2,311 — — 2,311 $ 21,683 $ — $ 21,683 $ 4,222 $ 11,846 $ 5,615 Customer repurchase agreements $ 176,913 $ — $ 176,913 $ — $ 176,913 $ — (1) Reflects offsetting derivative positions with the same counterparty.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES On December 22, 2017, the Tax Act was signed into law. At December 31, 2017, the Company has not completed its accounting for the tax effect of enactment of the Tax Act; however, it made a reasonable estimate of the effects on its existing deferred tax balances. One of the provisions included in the Tax Act was the reduction in the maximum federal corporate income tax rate from 35% to 21%, effective January 1, 2018. As a result of this rate reduction, the Company remeasured certain deferred tax assets and liabilities based on the rates at which they are expected to reverse in the future, which is generally 21% for Federal tax purposes. However, the Company is still analyzing certain aspects of the Tax Act and redefining its calculations, which could potentially affect the measurement of these balances or potentially give rise to new deferred tax amounts. The provisional amount recorded related to the remeasurement of deferred tax assets and liabilities was $1.9 million . The Company also recognized a provisional estimate of $466,000 to reassess the value of its low income housing projects investments ("LIHTC investments"), The impact of these provisional estimates are included in the disclosures below. The provision for income taxes is comprised of the following components: Years Ended December 31 2017 2016 2015 (Dollars in thousands) Current expense Federal $ 28,852 $ 26,549 $ 11,946 State 9,278 8,883 5,052 Total current expense 38,130 35,432 16,998 Deferred expense (benefit) Federal 7,953 153 8,466 State 1,258 (158 ) 1,754 Total deferred expense (benefit) 9,211 (5 ) 10,220 Total expense $ 47,341 $ 35,427 $ 27,218 The difference between the statutory federal income tax rate of 35% and the effective income tax rate reported for the last three years is detailed below: Years Ended December 31 2017 2016 2015 (Dollars in thousands) Computed statutory federal income tax provision $ 47,091 35.00 % $ 39,226 35.00 % $ 32,262 35.00 % State taxes, net of federal tax benefit 6,817 5.07 % 5,643 5.03 % 4,500 4.88 % Revaluation of net deferred tax assets 1,895 1.41 % — — % — — % Merger and other related costs (non-deductible) 213 0.16 % 210 0.19 % 185 0.20 % Change in valuation allowance 31 0.02 % 28 0.02 % 41 0.04 % New Markets Tax Credits (3,960 ) (2.94 )% (6,360 ) (5.67 )% (6,514 ) (7.07 )% Increase in cash surrender value of life insurance (1,445 ) (1.07 )% (1,431 ) (1.28 )% (1,292 ) (1.40 )% Stock-based compensation (1,258 ) (0.94 )% — — % — — % Low Income Housing Project Investments (1,253 ) (0.93 )% (1,641 ) (1.46 )% (1,182 ) (1.28 )% Nontaxable interest, net (987 ) (0.73 )% (996 ) (0.89 )% (973 ) (1.06 )% Other, net 197 0.15 % 748 0.67 % 191 0.22 % Total expense $ 47,341 35.20 % $ 35,427 31.61 % $ 27,218 29.53 % The tax-effected components of the net deferred tax asset at December 31 were as follows: 2017 2016 (Dollars in thousands) Deferred tax assets Accrued expenses not deducted for tax purposes $ 9,268 $ 15,401 Allowance for loan losses 16,702 24,681 Deferred gain on sale leaseback transaction 909 1,744 Employee and director equity compensation 1,559 2,095 Federal Home Loan Bank borrowings fair value adjustment 26 82 Loan basis difference fair value adjustment 3,070 4,336 Net operating loss carry-forward 127 69 Net unrealized loss on securities available for sale 106 — Other 527 1,015 Gross deferred tax assets 32,294 49,423 Valuation allowance (121 ) (69 ) Total deferred tax assets net of valuation allowance $ 32,173 $ 49,354 Deferred tax liabilities Core deposit and other intangibles $ 2,057 $ 3,040 Deferred loan fees, net 4,275 5,407 Fixed assets 5,270 6,168 Goodwill 10,265 14,737 Net unrealized gain on securities available for sale — 105 Derivatives fair value adjustment 524 454 Other 4,307 3,909 Gross deferred tax liabilities $ 26,698 $ 33,820 Total net deferred tax asset $ 5,475 $ 15,534 Deferred tax assets are to be reduced by a valuation allowance if, based on the weight of available evidence, it is more likely than not that some portion or all of the deferred tax assets will not be realized. The realization of the tax benefit depends upon the existence of sufficient taxable income within the carry-back and future periods. The Company believes that it is more likely than not that its deferred tax assets as of December 31, 2017 , excluding the deferred tax asset on certain state net operating losses, will be realized through the utilization of carry-back provisions to taxable income on prior years, future reversals of existing taxable temporary differences and by offsetting other future taxable income. The Company believes it is more likely than not that the deferred tax asset related to certain state net operating losses generated from the Company's investments in low income housing partnerships, which expire over a 20-year period, will not be realized and has recorded a valuation allowance of $121,000 at December 31, 2017 , attributable to this deferred tax asset. The Company has utilized all federal net operating loss carry forwards acquired from recent acquisitions that were subject to annual change in ownership limitations under Internal Revenue Code Section 382 as of December 31, 2017 . In addition, the Company does not have a federal net operating loss carry forward or general business credit carry forward subject to expiration as of December 31, 2017 . Uncertainty in Income Taxes The Company and its subsidiaries file income tax returns in the U.S. federal jurisdiction as well as in various states. The Company is subject to U.S. federal, state and local income tax examinations by tax authorities for the 2014 through 2016 tax years including any related income tax filings from its recent acquisitions. The Company believes that its income tax returns have been filed based upon applicable statutes, regulations and case law in effect at the time of filing, however, the Internal Revenue Service ("IRS") and /or state jurisdictions could disagree with the Company's interpretation upon examination. The Company accounts for uncertainties in income taxes by providing a tax reserve for certain positions. The following is a reconciliation of the beginning and ending amount of unrecognized tax benefits: (Dollars in thousands) Balance at December 31, 2015 $ 81 Reduction of tax positions for prior years — Increase for prior year tax position — Increase for current year tax positions 30 Balance at December 31, 2016 $ 111 Reduction of tax positions for prior years — Increase for prior year tax positions — Increase for current year tax positions 31 Balance at December 31, 2017 $ 142 Increases to the Company's unrealized tax positions occur as a result of accruing for the unrecognized tax benefit as well the accrual of interest and penalties related to prior year positions. Decreases in the Company's unrealized tax positions occur as a result of the statute of limitation lapsing on prior year positions and/or settlements relating to outstanding positions. The table above does not include the indirect federal benefit of state tax positions of approximately $21,000 . All of the Company’s unrecognized tax benefits, including the indirect federal benefit of state tax positions, are recorded as a component of income tax expense. During the years ended December 31, 2017 and 2016, the Company recognized approximately $18,000 and $11,000 in the provision for income taxes for interest and penalties related to uncertain tax positions. There were no such amounts recorded in the tax provision in 2015. As such, the Company has accrued approximately $29,000 and $11,000 for the payment of interest and penalties as of December 31, 2017 and 2016, respectively, which are not included in the table above.

LOW INCOME HOUSING PROJECT INVE

LOW INCOME HOUSING PROJECT INVESTMENTS Low Income Housing Project Investments	12 Months Ended
	Dec. 31, 2017
Low Income Housing Project Investments [Abstract]
Investments in Low Income Housing Projects [Text Block]	LOW INCOME HOUSING PROJECT INVESTMENTS The Company has invested in low income housing projects that generate Low Income Housing Tax Credits (“LIHTC”) which provide the Company with tax credits and operating loss tax benefits over a period of approximately 15 years. None of the original investment is expected to be repaid. The following table presents certain information related to the Company's investments in low income housing projects as of December 31: 2017 2016 2015 (Dollars in thousands) Original investment value $ 47,399 $ 47,379 $ 42,199 Current recorded investment $ 35,225 $ 39,606 $ 38,151 Unfunded liability obligation $ 4,536 $ 12,161 $ 14,607 Tax credits and benefits earned during the year $ 5,654 $ 5,366 $ 3,632 Amortization of investments during the year (1) $ 4,402 $ 3,725 $ 2,450 Net income tax benefit recognized during the year $ 1,253 $ 1,641 $ 1,182 (1) The 2017 amount is inclusive of $466,000 related to the revaluation of Low Income Housing tax credit investments as a result of the 2017 Tax Act.

EMPLOYEE BENEFIT PLANS

EMPLOYEE BENEFIT PLANS	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
EMPLOYEE BENEFIT PLANS	EMPLOYEE BENEFIT PLANS Pension The Company maintains a multiemployer defined benefit pension plan (the “Pension Plan”) administered by Pentegra Retirement Services (the “Fund” or “Pentegra Defined Benefit Plan for Financial Institutions”). The Fund does not segregate the assets or liabilities of all participating employers and accordingly, disclosure of plan assets, accumulated vested and nonvested benefits is not possible. Effective July 1, 2006, the Company froze the defined benefit plan by eliminating all future benefit accruals. In conjunction with the acquisition of Peoples Federal Bancshares, Inc., the parent of Peoples Federal Savings Bank ("Peoples") in 2015, the Company acquired the Peoples Federal Defined Benefit Pension Plan (“Peoples Plan”). The Peoples Plan was frozen at the date of acquisition and will be maintained in the same manner as the Pension Plan. The Peoples Plan is also administered by Pentegra Retirement Services under the same Fund as the Pension Plan. Additionally, in conjunction with the acquisition of Island Bancorp, the Company acquired the Edgartown National Bank Employee’s Retirement Plan. This pension plan was frozen at the date of acquisition and was subsequently dissolved. The Company’s participation in the Pension Plan and the Peoples Plan (the "Pension Plans") for the annual period ended December 31, 2017 , is outlined in the table below. The “EIN/Pension Plan Number” column provides the Employer Identification Number (“EIN”) and the three-digit plan number. The funding status of the Pension Plans is determined on the basis of the financial statements provided by the Fund using total plan assets and accumulated benefit obligation. The “FIP/RP Status Pending/Implemented” column indicates plans for which a financial improvement plan (“FIP”) or a rehabilitation plan (“RP”) is either pending or has been implemented. The “Expiration Date of Collective-Bargaining Agreement” column lists the expiration dates of any collective-bargaining agreement(s) to which the Pension Plans are subject. Funding Status FIP/RP Status Surcharge Expiration Minimum EIN/Pension 2017 2016 Pentegra defined benefit plan for financial institutions 13-5645888/333 At least 80 percent At least 80 percent No No N/A $ — Contributions to the Fund are based on each individual employer’s experience. The Company bears the market risk relating to the Pension Plan and will continue to fund the Pension Plan as required. The Pension Plan year is July 1 st through June 30 th . The Company’s total contributions to the Pension Plans did not represent more than 5% of the total contributions to the Pension Plan as indicated in the Pension Plan’s most recently available annual report dated June 30, 2017 . The comparability of employer contributions is impacted by asset performance, discount rates and the reduction in the number of covered employees year over year. The Company’s contributions to the Pension Plans were as follows for the periods indicated: Required Contributions - Plan Year Allocation Cash Payment Future period funding 2017-2018 2016-2017 2015-2016 (Dollars in thousands) 2017 $ 6,432 $ 5,000 $ 1,432 $ — $ — 2016 $ 6,245 $ 4,000 $ — $ 2,245 $ — 2015 $ 2,983 $ 1,215 $ — $ — $ 1,768 The Company’s total defined benefit plan expense was $1.9 million , $2.0 million , and $1.6 million , for the years ending December 31, 2017 , 2016 , and 2015 , respectively. Financial information for the Fund is made available through the public Form 5500 which is available by April 15 th of the year following the plan year end. Postretirement Benefit Plans Employees retiring from the Bank after attaining age 65 , who have rendered at least 10 years of continuous full time service with Rockland Trust are entitled to a fixed contribution toward the premium for postretirement health care benefits and a $5,000 benefit paid upon death. The health care benefits are subject to deductibles, co-payment provisions and other limitations. The Bank may amend or change these benefits periodically. Additionally, the Company has acquired small postretirement plans and/or agreements in conjunction with various acquisitions. The expense related to these plans for the years ending December 31, 2017 , 2016 , and 2015 was not material. Supplemental Executive Retirement Plans The Bank maintains frozen defined benefit supplemental executive retirement plans (“SERP”) for certain highly compensated employees designed to offset the impact of regulatory limits on benefits under qualified pension plans. The Bank also maintains defined benefit SERPs acquired from previous acquisitions. The Bank has established and funded Rabbi Trusts to accumulate funds in order to satisfy the contractual liability of these supplemental retirement plan benefits. These agreements provide for the Bank to pay all benefits from its general assets, and the establishment of these trust funds does not reduce nor otherwise affect the Bank’s continuing liability to pay benefits from such assets except that the Bank’s liability shall be offset by actual benefit payments made from the trusts. The related trust assets included in the Company's available for sale securities portfolio totaled $16.2 million and $16.0 million at December 31, 2017 and 2016 , respectively. The following table shows the defined benefit supplemental retirement expense, and the contributions paid to the plans which were used only to pay the current year benefits as of the dates indicated: 2017 2016 2015 (Dollars in thousands) Retirement expense $ 1,580 $ 1,513 $ 1,834 Contributions paid $ 367 $ 320 $ 276 Expected future benefit payments for the defined benefit supplemental executive retirement plans are presented below: Defined Benefit Supplemental Executive (Dollars in thousands) 2018 $ 408 2019 $ 481 2020 $ 467 2021 $ 461 2022 $ 454 2023-2027 $ 5,366 The measurement date used to determine the defined benefit supplemental executive retirement plans' benefits is December 31 for each of the years reported. The following table illustrates the status of the defined benefit supplemental executive retirement plans at December 31 for the years presented: Defined Benefit Supplemental Executive 2017 2016 2015 (Dollars in thousands) Change in accumulated benefit obligation Benefit obligation at beginning of year $ 14,177 $ 13,290 $ 12,537 Accumulated service cost 423 395 742 Interest cost 547 539 470 Actuarial loss/(gain) 969 273 (183 ) Benefits paid (367 ) (320 ) (276 ) Accumulated benefit obligation at end of year $ 15,749 $ 14,177 $ 13,290 Change in plan assets Fair value of plan assets at beginning of year $ — $ — $ — Employer contribution 367 320 276 Benefits paid (367 ) (320 ) (276 ) Fair value of plan assets at end of year $ — $ — $ — Funded status at end of year $ (15,749 ) $ (14,177 ) $ (13,290 ) Assets — — — Liabilities (15,749 ) (14,177 ) (13,290 ) Accrued benefit cost $ (15,749 ) $ (14,177 ) $ (13,290 ) Amounts recognized in accumulated other comprehensive income (“AOCI”) Net loss $ 3,465 $ 2,830 $ 2,859 Prior service cost 1,047 1,323 1,599 Amounts recognized in AOCI $ 4,512 $ 4,153 $ 4,458 Information for plans with an accumulated benefit obligation in excess of plan assets Projected benefit obligation $ 15,749 $ 14,177 $ 13,290 Accumulated benefit obligation $ 15,749 $ 14,177 $ 13,290 Net periodic benefit cost Service cost $ 423 $ 395 $ 742 Interest cost 547 539 470 Amortization of prior service cost 276 276 305 Recognized net actuarial loss 334 303 317 Net periodic benefit cost $ 1,580 $ 1,513 $ 1,834 Amounts in accumulated other comprehensive income expected to be recognized in net periodic benefit cost over next fiscal year Net actuarial loss $ 415 $ 338 $ 270 Net prior service cost $ 276 $ 276 $ 276 Discount rate used for benefit obligation 2.48-3.45% 2.49-3.94% 2.49-4.16% Discount rate used for net periodic benefit cost 2.49-3.94% 2.49-4.16% 2.24-3.84% Rate of compensation increase n/a n/a n/a Other Employee Benefits The Bank from time to time creates an incentive compensation plan for senior management and other officers to participate in at varying levels. In addition, the Bank may also pay a discretionary bonus to senior management, officers, and/or non-officers of the Bank. The expense for the incentive plans and the discretionary bonus amounted to $10.9 million in 2017 and $10.3 million in both 2016 and 2015 . The Bank has an Employee Savings Plan that qualifies as a deferred salary arrangement under Section 401(k) of the Internal Revenue Code. Under the Employee Savings Plan, participating employees may defer a portion of their earnings, not to exceed the Internal Revenue Service annual contribution limits. The Bank matches 25% of each employee’s contributions up to the first 6% of the employee’s earnings. The 401(k) Plan incorporates an Employee Stock Ownership Plan for contributions invested in the Company’s common stock. This Plan also provides nondiscretionary contributions in which employees, with one year and 1,000 hours of service, receive a 5% cash contribution of eligible pay up to the social security limit and a 10% cash contribution of eligible pay over the social security limit up to the maximum amount permitted by law. Benefits contributed to employees under this defined contribution plan vest immediately. The defined contribution plan expense was $5.0 million , $4.8 million and $4.5 million for the years ended December 2017 , 2016 and 2015 , respectively. The Company has a non-qualified deferred compensation plan which allows for deferrals of incentive payments until an elected distribution date in the future. This deferred compensation plan is available to certain highly compensated employees. Deferrals are invested at the election of the participant into one of the actively managed funds made available to the participant through the Company's Investment Management Group. The funds are held in a Rabbi Trust until the elected date of distribution. The Company has a non-qualified 401(k) Restoration Plan ("Restoration Plan") for certain executive officers. The Restoration Plan is intended to contribute to each participant the amount of matching and discretionary contributions which would have been made to the existing Rockland Trust 401(k) plan on the participant's behalf, but were prohibited due to Internal Revenue Code limitations. Deferrals are invested at the election of the participant into one of the actively managed funds made available to the participant through the Company's Investment Management Group or in the Company's stock. These funds are held in a Rabbi Trust until the elected date of distribution. The Company recognized expense of $267,000 , $425,000 and $232,000 related to this plan for services performed for the years ended December 31, 2017 , 2016 and 2015 , respectively. As a result of the acquisition of Peoples in 2015, the Company assumed an Employee Stock Ownership Plan and a 401(k) Plan. The Company received approval and terminated both plans during 2016, and as such, there was no expense associated with either plan during 2017 , 2016 and 2015 . Also as part of the Peoples acquisition, the Company assumed various Salary Continuation Agreements with certain current and former senior executives. The agreements require the payment of specified benefits upon retirement over periods of ten or twenty years as described in each agreement. Expense related to the Salary Continuation Agreements was $279,000 , $272,000 and $222,000 for the years ended December 31, 2017 , 2016 and 2015 , respectively. The Company also assumed a Peoples supplemental retirement plan with a former executive, whereby the amounts paid under this plan commenced upon the executive's retirement and continue for his lifetime. Expense related to the supplemental retirement plan was $11,000 , $13,000 and $11,000 for the years ended December 31, 2017 , 2016 and 2015 , respectively. Director Benefits The Company maintains a deferred compensation plan for the Company’s Board of Directors. The Board of Directors is entitled to elect to defer their director’s fees until retirement. If the Director elects to do so, their compensation is invested in the Company’s stock and maintained within the Company’s Investment Management Group. The amount of compensation deferred during 2017 , 2016 , and 2015 was $143,000 , $142,000 , and $149,000 , respectively. At December 31, 2017 and 2016 , the Company had 161,961 and 168,352 of shares provided for the plan with a related liability of $4.5 million and $4.2 million established within shareholders’ equity, respectively. As a result of the Peoples acquisition during 2015, the Company assumed several Director Retirement Agreements. The agreements require the payment of specified benefits upon retirement over periods of ten or twenty years as described in each agreement. Expense for the Director Retirement Agreements was $38,000 , $40,000 and $35,000 for the years ended December 31, 2017 , 2016 and 2015 , respectively.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Fair value is a market-based measure considered from the perspective of a market participant rather than an entity-specific measure. Therefore, even when market assumptions are not readily available, the Company’s own assumptions are set to reflect those that market participants would use in pricing the asset or liability at the measurement date. If there has been a significant decrease in the volume and level of activity for the asset or liability, regardless of the valuation technique(s) used, the objective of a fair value measurement remains the same. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction (that is, not a forced liquidation or distressed sale) between market participants at the measurement date under current market conditions. The Company uses prices and inputs that are current as of the measurement date. In periods of market dislocation, the observability of prices and inputs may be reduced for many instruments. This condition could cause an instrument to be reclassified from one level to another. The Fair Value Measurements and Disclosures Topic of the FASB ASC defines fair value and establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy under the Fair Value Measurements and Disclosures Topic of the FASB ASC are described below: Level 1 – Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 2 – Valuations based on quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3 – Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Valuation Techniques There have been no changes in the valuation techniques used during the current period. Securities: Trading and Equity Securities These equity securities are valued based on market quoted prices. These securities are categorized in Level 1 as they are actively traded and no valuation adjustments have been applied. U.S. Government Agency Securities Fair value is estimated using either multi-dimensional spread tables or benchmarks. The inputs used include benchmark yields, reported trades, and broker/dealer quotes. These securities are classified as Level 2. Agency Mortgage-Backed Securities Fair value is estimated using either a matrix or benchmarks. The inputs used include benchmark yields, reported trades, broker/dealer quotes, and issuer spreads. These securities are categorized as Level 2. Agency Collateralized Mortgage Obligations and Small Business Administration Pooled Securities The valuation model for these securities is volatility-driven and ratings based, and uses multi-dimensional spread tables. The inputs used include benchmark yields, reported trades, new issue data, broker dealer quotes, and collateral performance. If there is at least one significant model assumption or input that is not observable, these securities are categorized as Level 3 within the fair value hierarchy; otherwise, they are classified as Level 2. State, County, and Municipal Securities The fair value is estimated using a valuation matrix with inputs including bond interest rate tables, recent transaction, and yield relationships. These securities are categorized as Level 2. Single and Pooled Issuer Trust Preferred Securities The fair value of trust preferred securities, including pooled and single issuer preferred securities, is estimated using external pricing models, discounted cash flow methodologies or similar techniques. The inputs used in these valuations include benchmark yields, reported trades, new issue data, broker dealer quotes, and collateral performance. If there is at least one significant model assumption or input that is not observable, these securities are classified as Level 3 within the fair value hierarchy; otherwise, they are classified as Level 2. Loans Held for Sale The Company has elected the fair value option to account for originated closed loans intended for sale. The fair value is measured on an individual loan basis using quoted market prices and when not available, comparable market value or discounted cash flow analysis may be utilized. These assets are typically classified as Level 2. Derivative Instruments Derivatives The valuation of these instruments is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves and implied volatilities. The Company incorporates credit valuation adjustments to appropriately reflect nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Company has considered the impact of netting and any applicable credit enhancements, such as collateral postings. Additionally, in conjunction with fair value measurement guidance, the Company has made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio. Although the Company has determined that the majority of the inputs used to value its interest rate derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by the Company and its counterparties. However, as of December 31, 2017 and 2016 , the Company 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 Company has determined that its derivative valuations in their entirety are classified in Level 2. Mortgage Derivatives The fair value of mortgage derivatives is determined based on current market prices for similar assets in the secondary market and, therefore, classified as Level 2 within the fair value hierarchy. Impaired Loans Collateral dependent loans that are deemed to be impaired are valued based upon the lower of cost or fair value of the underlying collateral less costs to sell. The inputs used in the appraisals of the collateral are not always observable, and therefore the loans may be classified as Level 3 within the fair value hierarchy; otherwise, they are classified as Level 2. Other Real Estate Owned and Other Foreclosed Assets The fair values are generally estimated based upon recent appraisal values of the property less costs to sell the property, as Other Real Estate Owned ("OREO") and Other Foreclosed Assets are valued at the lower of cost or fair value of the property, less estimated costs to sell. Certain inputs used in appraisals are not always observable, and therefore OREO and Other Foreclosed Assets are classified as Level 3 within the fair value hierarchy. Goodwill and Other Intangible Assets Goodwill and identified intangible assets are subject to impairment testing. The Company conducts an annual impairment test of goodwill in the third quarter of each year, or more frequently if necessary, and other intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. To estimate the fair value of goodwill and, if necessary, other intangible assets, the Company utilizes both a comparable analysis of relevant price multiples in recent market transactions and discounted cash flow analysis. Both valuation models require a significant degree of management judgment. In the event the fair value as determined by the valuation model is less than the carrying value, the intangibles may be impaired. If the impairment testing resulted in impairment, the Company would classify the impaired goodwill and other intangible assets subjected to nonrecurring fair value adjustments as Level 3. Assets and liabilities measured at fair value on a recurring and nonrecurring basis were as follows as of the dates indicated: Fair Value Measurements at Reporting Date Using Balance Quoted Prices in Significant Other Significant December 31, 2017 (Dollars in thousands) Recurring fair value measurements Assets Trading securities $ 1,324 $ 1,324 $ — $ — Securities available for sale U.S. Government agency securities 35,430 — 35,430 — Agency mortgage-backed securities 215,764 — 215,764 — Agency collateralized mortgage obligations 122,012 — 122,012 — State, county, and municipal securities 2,274 — 2,274 — Single issuer trust preferred securities issued by banks and insurers 2,016 — 2,016 — Pooled trust preferred securities issued by banks and insurers 1,640 — — 1,640 Small business administration pooled securities 47,778 — 47,778 — Equity securities 20,584 20,584 — — Loans held for sale 4,768 — 4,768 — Derivative instruments 17,476 — 17,476 — Liabilities Derivative instruments 15,693 — 15,693 — Total recurring fair value measurements $ 455,373 $ 21,908 $ 431,825 $ 1,640 Nonrecurring fair value measurements Assets Collateral dependent impaired loans $ 33,567 $ — $ — $ 33,567 Other real estate owned and other foreclosed assets 612 — — 612 Total nonrecurring fair value measurements $ 34,179 $ — $ — $ 34,179 Fair Value Measurements at Reporting Date Using Balance Quoted Prices in Significant Other Significant December 31, 2016 (Dollars in thousands) Recurring fair value measurements Assets Trading securities $ 804 $ 804 $ — $ — Securities available for sale U.S. Government agency securities 24,244 $ — 24,244 — Agency mortgage-backed securities 175,384 — 175,384 — Agency collateralized mortgage obligations 99,868 — 99,868 — State, county, and municipal securities 3,793 — 3,793 — Single issuer trust preferred securities issued by banks and insurers 2,311 — 2,311 — Pooled trust preferred securities issued by banks and insurers 1,584 — — 1,584 Small business administration pooled securities 37,189 — 37,189 — Equity securities 19,271 19,271 — — Loans held for sale 6,139 — 6,139 — Derivative instruments 22,761 — 22,761 — Liabilities Derivative instruments 21,916 — 21,916 — Total recurring fair value measurements $ 371,432 $ 20,075 $ 349,773 $ 1,584 Nonrecurring fair value measurements: Assets Collateral dependent impaired loans $ 33,974 $ — $ — $ 33,974 Other real estate owned and other foreclosed assets 4,173 — — 4,173 Total nonrecurring fair value measurements $ 38,147 $ — $ — $ 38,147 All assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) were valued using pricing models and discounted cash flow methodologies, as of December 31, 2017 , 2016 and 2015 . This reconciliation is presented in the table below, for the periods indicated: 2017 2016 2015 (Dollars in thousands) Pooled Trust Preferred Securities Beginning balance $ 1,584 $ 1,572 $ 6,321 Gain and (losses) (realized/unrealized) Included in other comprehensive income 77 29 14 Sales — — (4,679 ) Settlements (21 ) (17 ) (84 ) Ending Balance $ 1,640 $ 1,584 $ 1,572 It is the Company’s policy to recognize the transfers between levels of the fair value hierarchy as of the end of the reporting period. There were no transfers between the levels of the fair value hierarchy for any assets or liabilities measured at fair value on a recurring basis during the years ended December 31, 2017 , 2016 and 2015 . The following table sets forth certain unobservable inputs regarding the Company's financial instruments that are classified as Level 3 as of December 31st for the years indicated: Valuation Technique Fair Value Unobservable Inputs Range Weighted Average 2017 2016 2017 2016 2017 2016 (Dollars in thousands) Discounted cash flow methodology Pooled trust preferred securities $ 1,640 $ 1,584 Cumulative prepayment 0% - 61% 0% - 62% 2.5% 2.5% Cumulative default 5% - 100% 5% - 100% 12.4% 12.8% Loss given default 85% - 100% 85% - 100% 94.3% 94.2% Cure given default 0% - 75% 0% - 75% 60.9% 60.9% Appraisals of collateral (1) Collateral dependent impaired loans $ 33,567 $ 33,974 Other real estate owned and foreclosed assets $ 612 $ 4,173 (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various Level 3 inputs which are not identifiable. Appraisals may be adjusted by management for qualitative factors such as economic factors and estimated liquidation expenses. The range of these possible adjustments may vary. For the fair value measurements in the table above, which are classified as Level 3 within the fair value hierarchy, the Company’s Treasury and Finance groups determine the valuation policies and procedures. For the pricing of the securities, the Company uses third-party pricing information, without adjustment. Depending on the type of the security, management employs various techniques to analyze the pricing it receives from third parties, such as analyzing changes in market yields and in certain instances reviewing the underlying collateral of the security. Management reviews changes in fair value from period to period and performs testing to ensure that prices received from the third parties are consistent with their expectation of the market. For the securities whose market is deemed to be inactive and which are categorized as Level 3, the fair value models are calibrated and significant inputs are back tested on a quarterly basis, to the extent possible. This testing is done by the third party service provider, who performs this testing by comparing anticipated inputs to actual results. Significant changes in fair value from period to period are closely scrutinized to ensure fair value models are not flawed. The driver(s) of the respective change in fair value and the method for forecasting the driver(s) is closely considered by management. The significant unobservable inputs used in the fair value measurement of the Company’s pooled trust preferred securities are cumulative prepayment rates, cumulative defaults, loss given defaults and cure given defaults. Significant increases (decreases) in deferrals or defaults, in isolation, would result in a significantly lower (higher) fair value measurement. Alternatively, significant increases (decreases) in cure rates, in isolation, would result in a significantly higher (lower) fair value measurement. Additionally, the Company has certain assets which are marked to fair value on a nonrecurring basis which are categorized within Level 3. These assets include collateral dependent impaired loans and OREO. The determination of the fair value amount is derived from the use of independent third party real estate appraisals and evaluations. Real estate appraisals are prepared by firms from a predetermined list of qualified and approved appraisers or evaluators. Upon receipt of a real estate appraisal or evaluation, the Company's Commercial Real Estate Appraisal Department will review the report for compliance with regulatory and Company standards, as well as reasonableness and acceptance of the value conclusions. Any issues or concerns regarding compliance or value conclusions will be addressed with the engaged firm and the report may be adjusted or revised. If a disagreement cannot be resolved, the Company will either address the key issues and modify the report for acceptance or reject the report and re-order a new report. Ultimately, the Company will confirm the collateral value as part of its review process. The estimated fair values and related carrying amounts for assets and liabilities for which fair value is only disclosed are shown below as of the periods indicated: Fair Value Measurements at Reporting Date Using Carrying Value Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) December 31, 2017 (Dollars in thousands) Financial assets Securities held to maturity(a) U.S. Treasury securities $ 1,006 $ 1,035 $ — $ 1,035 $ — Agency mortgage-backed securities 204,768 205,823 — 205,823 — Agency collateralized mortgage obligations 262,998 258,408 — 258,408 — Single issuer trust preferred securities issued by banks 1,500 1,529 — 1,529 — Small business administration pooled securities 27,416 27,399 — 27,399 — Loans, net of allowance for loan losses(b) 6,261,343 6,116,051 — — 6,116,051 Federal Home Loan Bank stock(c) 11,597 11,597 — 11,597 — Cash surrender value of life insurance policies(d) 151,528 151,528 — 151,528 — Financial liabilities Deposit liabilities, other than time deposits(e) $ 6,084,952 $ 6,084,952 $ — $ 6,084,952 $ — Time certificates of deposits(f) 644,301 639,060 — 639,060 $ — Federal Home Loan Bank borrowings(f) 53,264 52,111 — 52,111 — Customer repurchase agreements and other short-term borrowings(f) 162,679 162,679 — — 162,679 Junior subordinated debentures(g) 73,073 74,680 — 74,680 — Subordinated debentures(f) 34,682 32,707 — — 32,707 Fair Value Measurements at Reporting Date Using Carrying Value Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) December 31, 2016 Financial assets (Dollars in thousands) Securities held to maturity(a) U.S. Treasury securities $ 1,007 $ 1,054 $ — $ 1,054 $ — Agency mortgage-backed securities 156,088 157,504 — 157,504 — Agency collateralized mortgage obligations 297,445 294,650 — 294,650 — Single issuer trust preferred securities issued by banks 1,500 1,544 — 1,544 — Small business administration pooled securities 31,036 30,898 — 30,898 — Loans, net of allowance for loan losses(b) 5,904,065 5,784,778 — — 5,784,778 Federal Home Loan Bank stock(c) 11,497 11,497 — 11,497 — Cash surrender value of life insurance policies(d) 144,503 144,503 — 144,503 — Financial liabilities Deposit liabilities, other than time deposits(e) $ 5,763,101 $ 5,763,101 $ — $ 5,763,101 $ — Time certificates of deposits(f) 649,152 647,038 — 647,038 — Federal Home Loan Bank borrowings(f) 50,819 50,898 — 50,898 — Customer repurchase agreements and other short-term borrowings(f) 176,913 176,913 — — 176,913 Junior subordinated debentures(g) 73,107 72,510 — 72,510 — Subordinated debentures(f) 34,635 34,241 — — 34,241 (a) The fair values presented are based on quoted market prices, where available. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments and/or discounted cash flow analysis. (b) Fair value is estimated by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities or cash flows. Additionally, this amount excludes collateral dependent impaired loans, which are deemed to be marked to fair value on a nonrecurring basis. (c) FHLB stock has no quoted market value and is carried at cost, therefore the carrying amount approximates fair value. (d) Cash surrender value of life insurance is recorded at its cash surrender value (or the amount that can be realized upon surrender of the policy), therefore carrying amount approximates fair value. (e) Fair value of demand deposits, savings and interest checking accounts and money market deposits is the amount payable on demand at the reporting date. (f) Fair value was determined by discounting anticipated future cash payments using rates currently available for instruments with similar remaining maturities. (g) Fair value was determined based upon market prices of securities with similar terms and maturities. This summary excludes certain financial assets and liabilities for which the carrying value approximates fair value. For financial assets, these may include cash and due from banks, federal funds sold and short-term investments. For financial liabilities, these may include federal funds purchased. These instruments would all be considered to be classified as Level 1 within the fair value hierarchy. Also excluded from the summary are financial instruments measured at fair value on a recurring and nonrecurring basis, as previously described. The Company considers its financial instruments' current use to be the highest and best use of the instruments.

OTHER COMPREHENSIVE LOSS

OTHER COMPREHENSIVE LOSS	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
OTHER COMPREHENSIVE LOSS	OTHER COMPREHENSIVE INCOME (LOSS) The following table presents a reconciliation of the changes in the components of other comprehensive income (loss) for the dates indicated, including the amount of income tax (expense) benefit allocated to each component of other comprehensive income (loss): December 31, 2017 Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ (996 ) $ 321 $ (675 ) Less: net security gains reclassified into other noninterest income (expense) 3 (1 ) 2 Net change in fair value of securities available for sale (999 ) 322 (677 ) Change in fair value of cash flow hedges 307 (125 ) 182 Less: net cash flow hedge losses reclassified into interest on borrowings expense (1) (441 ) 180 (261 ) Net change in fair value of cash flow hedges 748 (305 ) 443 Net unamortized loss related to defined benefit pension and other postretirement adjustments arising during the period (995 ) 407 (588 ) Amortization of net actuarial losses 278 (113 ) 165 Amortization of net prior service cost 276 (113 ) 163 Net change in other comprehensive income for defined benefit postretirement plans (2) (441 ) 181 (260 ) Total other comprehensive loss $ (692 ) $ 198 $ (494 ) Year Ended December 31, 2016 Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ (1,858 ) $ 710 $ (1,148 ) Less: net security losses reclassified into other noninterest income (expense) (26 ) 11 (15 ) Net change in fair value of securities available for sale (1,832 ) 699 (1,133 ) Change in fair value of cash flow hedges 1,133 (453 ) 680 Less: net cash flow hedge losses reclassified into interest on borrowings expense (1) (2,520 ) 1,030 (1,490 ) Net change in fair value of cash flow hedges 3,653 (1,483 ) 2,170 Net unamortized loss related to defined benefit pension and other postretirement adjustments arising during the period (383 ) 157 (226 ) Amortization of net actuarial losses 238 (97 ) 141 Amortization of net prior service cost 276 (113 ) 163 Net change in other comprehensive income for defined benefit postretirement plans (2) 131 (53 ) 78 Total other comprehensive income $ 1,952 $ (837 ) $ 1,115 Year Ended December 31, 2015 Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ (3,757 ) $ 1,434 $ (2,323 ) Less: net security losses reclassified into other noninterest income (expense) (405 ) 165 (240 ) Net change in fair value of securities available for sale (3,352 ) 1,269 (2,083 ) Change in fair value of cash flow hedges (776 ) 299 (477 ) Less: Net cash flow hedge losses reclassified into interest on borrowings expense (1) (2,828 ) 1,152 (1,676 ) Net change in fair value of cash flow hedges 2,052 (853 ) 1,199 Net unamortized gain related to defined benefit pension and other postretirement adjustments arising during the period 438 (193 ) 245 Amortization of net actuarial losses 243 (99 ) 144 Amortization of net prior service cost 294 (119 ) 175 Net change in other comprehensive income for defined benefit postretirement plans (2) 975 (411 ) 564 Total other comprehensive loss $ (325 ) $ 5 $ (320 ) (1) Includes the amortization of the remaining balance of a realized but unrecognized gain, net of tax, from the termination of interest rate swaps in 2009. The original gain of $1.4 million , net of tax, will be recognized in earnings through December 2018 , the original maturity date of the swap. The balance of this gain had amortized to $137,000 , $281,000 , and $427,000 at December 31, 2017 , 2016 , and 2015 , respectively. (2) The amortization of prior service costs is included in the computation of net periodic pension costs as disclosed in Note 15 - Employee Benefit Plans . Information on the Company's accumulated other comprehensive loss, net of tax, is comprised of the following components as of the periods indicated: Unrealized Gain (Loss) on Securities Unrealized Gain (Loss) on Cash Flow Hedge Deferred Gain on Hedge Transactions Defined Benefit Postretirement Plans Accumulated Other Comprehensive Income (Loss) (Dollars in Thousands) Beginning balance: January 1, 2015 $ 3,389 $ (3,298 ) $ 571 $ (2,794 ) $ (2,132 ) Net change in other comprehensive income (loss) (2,083 ) 1,343 (144 ) 564 (320 ) Ending balance: December 31, 2015 $ 1,306 $ (1,955 ) $ 427 $ (2,230 ) $ (2,452 ) Net change in other comprehensive income (loss) (1,133 ) 2,316 (146 ) 78 1,115 Ending balance: December 31, 2016 $ 173 $ 361 $ 281 $ (2,152 ) $ (1,337 ) Net change in other comprehensive income (loss) (677 ) 587 (144 ) (260 ) (494 ) Ending balance: December 31, 2017 $ (504 ) $ 948 $ 137 $ (2,412 ) $ (1,831 )

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Financial Instruments with Off-Balance Sheet Risk In the normal course of business, the Company enters into various transactions to meet the financing needs of its customers, which, in accordance with GAAP, are not included in its consolidated balance sheets. These transactions include commitments to extend credit and standby letters of credit, which involve, to varying degrees, elements of credit risk and interest rate risk in excess of the amounts recognized in the consolidated balance sheets. The Company minimizes its exposure to loss under these commitments by subjecting them to credit approval and monitoring procedures. The Company enters into contractual commitments to extend credit, normally with fixed expiration dates or termination clauses, at specified rates and for specific purposes. Substantially all of these commitments to extend credit are contingent upon customers maintaining specific credit standards at the time of loan funding. Standby letters of credit are written conditional commitments issued to guarantee the performance of a customer to a third party. In the event the customer does not perform in accordance with the terms of the agreement with the third party, the Company would be required to fund the commitment. The maximum potential amount of future payments the Company could be required to make is represented by the contractual amount of the commitment. If the commitment were funded, the Company would be entitled to seek recovery from the customer. The Company’s policies generally require that standby letter of credit arrangements contain security and debt covenants similar to those contained in loan agreements. The fees collected in connection with the issuance of standby letters of credit are representative of the fair value of its obligation undertaken in issuing the guarantee. In accordance with applicable accounting standards related to guarantees, fees collected in connection with the issuance of standby letters of credit are deferred. The fees are then recognized in income proportionately over the life of the standby letter of credit agreement. The deferred standby letter of credit fees represent the fair value of the Company's potential obligations under the standby letter of credit guarantees. The following table summarizes the above financial instruments at the dates indicated: As of December 31 2017 2016 (Dollars in thousands) Commitments to extend credit $ 2,443,478 $ 2,227,955 Standby letters of credit $ 15,534 $ 18,190 Deferred standby letter of credit fees $ 102 $ 108 Lease Commitments The Company leases office space, space for ATM locations, and certain branch locations under noncancelable operating leases. The following is a schedule of minimum future lease payments under such leases as of December 31, 2017 : (Dollars in thousands) 2018 $ 9,023 2019 8,808 2020 7,771 2021 6,508 2022 4,437 Thereafter 8,214 Total future minimum lease commitments $ 44,761 Rent expense incurred under operating leases was approximately $8.6 million in 2017 , $8.5 million in 2016 , and $8.2 million in 2015 . Renewal options ranging from 4 months -10 years exist for several of these leases. Other Contingencies At December 31, 2017 , Rockland Trust was involved in pending lawsuits that arose in the ordinary course of business. Management has reviewed these pending lawsuits with legal counsel and has taken into consideration the view of counsel as to their outcome. In the opinion of management, the final disposition of pending lawsuits is not expected to have a material adverse effect on the Company’s financial position or results of operations. The Bank is required to maintain certain reserve requirements of vault cash and/or deposits with the Federal Reserve Bank of Boston. The amount of this reserve requirement was $35.8 million and $31.8 million at December 31, 2017 and 2016 , respectively.

REGULATORY CAPITAL REQUIREMENTS

REGULATORY CAPITAL REQUIREMENTS	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
REGULATORY CAPITAL REQUIREMENTS	REGULATORY MATTERS Regulatory Capital Requirements The Company and the Bank are subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company’s financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company and the Bank must meet specific capital guidelines that involve quantitative measures of the Company’s and the Bank’s assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. The capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors. At December 31, 2017 the most recent notification from the Federal Deposit Insurance Corporation indicated that the Bank's capital levels met or exceeded the minimum levels to be considered "well capitalized" for bank regulatory purposes. To be categorized as well capitalized, an institution must maintain minimum total risk-based, Tier 1 risk-based, Common equity Tier 1 risk-based and Tier 1 leverage ratios as set forth in the following tables. There are no conditions or events since the notification that management believes have changed the Bank’s category. Management believes, as of December 31, 2017 and 2016 , that the Company and the Bank met all capital adequacy requirements to which they are subject. The Company’s and the Bank’s actual capital amounts and ratios as of December 31, 2017 and 2016 are also presented in the table that follows: Actual For Capital To Be Well Capitalized Amount Ratio Amount Ratio Amount Ratio December 31, 2017 (Dollars in thousands) Independent Bank Corp. Total capital (to risk weighted assets) $ 886,807 13.82 % $ 513,398 ≥ 8.0 % N/A N/A Common equity tier 1 capital (to risk weighted assets) $ 718,995 11.20 % $ 288,787 ≥ 4.5 % N/A N/A Tier 1 capital (to risk weighted assets) $ 789,992 12.31 % $ 385,049 ≥ 6.0 % N/A N/A Tier 1 capital (to average assets) $ 789,992 10.04 % $ 314,756 ≥ 4.0 % N/A N/A Rockland Trust Company Total capital (to risk weighted assets) $ 846,147 13.19 % $ 513,175 ≥ 8.0 % $ 641,469 ≥ 10.0 % Common equity tier 1 capital (to risk weighted assets) $ 784,014 12.22 % $ 288,661 ≥ 4.5 % $ 416,955 ≥ 6.5 % Tier 1 capital (to risk weighted assets) $ 784,014 12.22 % $ 384,881 ≥ 6.0 % $ 513,175 ≥ 8.0 % Tier 1 capital (to average assets) $ 784,014 9.97 % $ 314,630 ≥ 4.0 % $ 393,288 ≥ 5.0 % December 31, 2016 (Dollars in thousands) Independent Bank Corp. Total capital (to risk weighted assets) $ 824,265 13.60 % $ 484,942 ≥ 8.0 % N/A N/A Common equity tier 1 capital (to risk weighted assets) $ 656,080 10.82 % $ 272,780 ≥ 4.5 % N/A N/A Tier 1 capital (to risk weighted assets) $ 727,070 11.99 % $ 363,706 ≥ 6.0 % N/A N/A Tier 1 capital (to average assets) $ 727,070 9.77 % $ 297,748 ≥ 4.0 % N/A N/A Rockland Trust Company Total capital (to risk weighted assets) $ 788,320 13.01 % $ 484,834 ≥ 8.0 % $ 606,042 ≥ 10.0 % Common equity tier 1 capital (to risk weighted assets) $ 725,760 11.98 % $ 272,719 ≥ 4.5 % $ 393,927 ≥ 6.5 % Tier 1 capital (to risk weighted assets) $ 725,760 11.98 % $ 363,625 ≥ 6.0 % $ 484,834 ≥ 8.0 % Tier 1 capital (to average assets) $ 725,760 9.76 % $ 297,589 ≥ 4.0 % $ 371,986 ≥ 5.0 % In addition to the minimum risk-based capital requirements outlined in the table above, the Company 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 is being phased-in, beginning at 0.625% on January 1, 2016 and ultimately increasing to 2.5% on January 1, 2019. The Company's capital levels exceeded the minimum requirement plus the fully phased-in buffer of 2.5% as of December 31, 2017 . Dividend Restrictions In the ordinary course of business, the Company is dependent upon dividends from the Bank to provide funds for the payment of dividends to shareholders and to provide for other cash requirements. Banking regulations may limit the amount of dividends that may be paid. Approval by regulatory authorities is required if the effect of dividends declared would cause the regulatory capital of the Bank to fall below specified minimum levels. Approval is also required if dividends declared exceed the net profits for that year combined with the retained net profits for the preceding two years. Under the foregoing dividend restrictions and while maintaining its "well capitalized" status, dividends paid by the Bank to the Company for the year ended December 31, 2017 and 2016 totaled $46.9 million and $44.5 million , respectively. Trust Preferred Securities In accordance with the applicable accounting standard related to variable interest entities, the common stock of trusts which have issued trust preferred securities have not been included in the consolidated financial statements. At December 31, 2017 and 2016 , $71.0 million in trust preferred securities have been included in the Tier 1 capital of the Company for regulatory reporting purposes pursuant to the Federal Reserve's capital adequacy guidelines.

PARENT COMPANY FINANCIALS ONLY

PARENT COMPANY FINANCIALS ONLY	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
PARENT COMPANY FINANCIAL STATEMENTS	PARENT COMPANY FINANCIAL STATEMENTS Condensed financial information relative to the Parent Company’s balance sheets at December 31, 2017 and 2016 and the related statements of income and cash flows for the years ended December 31, 2017 , 2016 , and 2015 are presented below. The statement of stockholders’ equity is not presented below as the parent company’s stockholders’ equity is that of the consolidated Company. BALANCE SHEETS December 31 2017 2016 (Dollars in thousands) Assets Cash(1) $ 48,131 $ 42,596 Investments in subsidiaries(2) 1,010,125 935,778 Prepaid income taxes 786 625 Deferred tax asset 96 216 Derivative instruments(1) 1,535 1,364 Total assets $ 1,060,673 $ 980,579 Liabilities and stockholders’ equity Dividends payable $ 8,786 $ 7,834 Junior subordinated debentures 73,073 73,107 Subordinated debentures 34,682 34,635 Other liabilities 323 313 Total liabilities 116,864 115,889 Stockholders’ equity 943,809 864,690 Total liabilities and stockholders’ equity $ 1,060,673 $ 980,579 (1) Entire balance eliminates in consolidation. (2) $1.0 billion and $933.6 million eliminate in consolidation at December 31, 2017 and 2016 , respectively. STATEMENTS OF INCOME Years Ended December 31 2017 2016 2015 (Dollars in thousands) Income Dividends received from subsidiaries(1) $ 47,006 $ 44,598 $ 38,153 Interest income(2) 50 98 78 Total income 47,056 44,696 38,231 Expenses Interest expense 3,995 5,901 5,769 Other expenses — — 29 Total expenses 3,995 5,901 5,798 Income before income taxes and equity in undistributed income of subsidiaries 43,061 38,795 32,433 Income tax benefit (1,523 ) (1,791 ) (2,301 ) Income of parent company 44,584 40,586 34,734 Equity in undistributed income of subsidiaries 42,620 36,062 30,226 Net income $ 87,204 $ 76,648 $ 64,960 (1) Income of $67,000 , $62,000 and $55,000 was not eliminated in consolidation for the years ended December 31, 2017 , 2016 , and 2015 , respectively. (2) Entire balance eliminated in consolidation. STATEMENTS OF CASH FLOWS Years Ended December 31 2017 2016 2015 (Dollars in thousands) Cash flows from operating activities Net income $ 87,204 $ 76,648 $ 64,960 Adjustments to reconcile net income to cash provided by operating activities Amortization (accretion) 12 (154 ) (150 ) Deferred income tax expense 51 678 3,266 Change in other assets (99 ) 423 7,488 Change in other liabilities (562 ) (5,532 ) (254 ) Equity in undistributed income of subsidiaries (42,620 ) (36,062 ) (30,226 ) Net cash provided by operating activities 43,986 36,001 45,084 Cash flows used in investing activities Cash paid for acquisitions, net of cash acquired (1) (4,834 ) (950 ) (51,680 ) Net cash used in investing activities (4,834 ) (950 ) (51,680 ) Cash flows used in financing activities Restricted stock awards issued, net of awards surrendered (1,422 ) (696 ) (657 ) Net proceeds from exercise of stock options 214 201 1,367 Proceeds from shares issued under the direct stock purchase plan 1,636 2,323 2,695 Common dividends paid (34,045 ) (29,711 ) (26,172 ) Net cash used in financing activities (33,617 ) (27,883 ) (22,767 ) Net increase (decrease) in cash and cash equivalents 5,535 7,168 (29,363 ) Cash and cash equivalents at the beginning of the year 42,596 35,428 64,791 Cash and cash equivalents at the end of the year $ 48,131 $ 42,596 $ 35,428 (1) The majority of the net assets acquired at the parent company represented each of the acquired companies' investments in their wholly owned subsidiaries, which were eliminated in consolidation at December 31, 2017 , 2016 , and 2015 , respectively.

SELECTED QUARTERLY FINANCIAL DA

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) First Quarter Second Quarter Third Quarter Fourth Quarter 2017 2016 2017 2016 2017 2016 2017 2016 (Dollars in thousands, except per share data) Interest income $ 64,407 $ 59,741 $ 68,133 $ 61,160 $ 71,778 $ 62,308 $ 72,876 $ 63,428 Interest expense 4,207 4,850 4,378 4,627 4,705 4,640 5,044 4,676 Net interest income 60,200 54,891 63,755 56,533 67,073 57,668 67,832 58,752 Provision for loan losses 600 525 1,050 600 — 950 1,300 4,000 Total noninterest income 18,912 19,155 21,398 21,095 20,770 20,416 21,914 21,762 Total noninterest expenses 48,773 46,482 52,809 47,146 51,310 46,857 51,467 51,637 Provision for income taxes 9,014 8,428 10,731 9,508 12,681 9,793 14,915 7,698 Net income $ 20,725 $ 18,611 $ 20,563 $ 20,374 $ 23,852 $ 20,484 $ 22,064 $ 17,179 Basic earnings per share $ 0.77 $ 0.71 $ 0.75 $ 0.77 $ 0.87 $ 0.78 $ 0.80 $ 0.64 Diluted earnings per share $ 0.76 $ 0.71 $ 0.75 $ 0.77 $ 0.87 $ 0.78 $ 0.80 $ 0.64 Weighted average common shares (basic) 27,029,640 26,275,323 27,257,799 26,304,129 27,436,792 26,324,316 27,445,739 26,710,029 Common stock equivalents 81,283 43,409 74,497 47,885 76,307 53,072 77,615 60,022 Weighted average common shares (diluted) 27,110,923 26,318,732 27,332,296 26,352,014 27,513,099 26,377,388 27,523,354 26,770,051 Unusual or infrequently occurring items Items within noninterest expense Loss on extinguishment of debt $ — $ 437 $ — $ — $ — $ — $ — $ — Merger and acquisition expense 484 334 2,909 206 — 151 — 4,764 Total $ 484 $ 771 $ 2,909 $ 206 $ — $ 151 $ — $ 4,764 Items within provision for income taxes 2017 Tax Act: revaluation of net deferred tax assets $ — $ — $ — $ — $ — $ — $ 1,895 $ — 2017 Tax Act: revaluation of LIHTC investments $ — $ — $ — $ — $ — $ — $ 466 $ — Total $ — $ — $ — $ — $ — $ — $ 2,361 $ —

TRANSACTIONS WITH RELATED PARTI

TRANSACTIONS WITH RELATED PARTIES (Notes)	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions Disclosure [Text Block]	TRANSACTIONS WITH RELATED PARTIES Certain directors and officers (including their affiliates, certain family members and entities in which they are principal owners) of the Company are customers of and have had, and are expected to have, transactions with the Company, within the ordinary course of business. These transactions include, but are not limited to, lending activities, deposit services, investment management, and property lease commitments. In the opinion of management, such transactions are consistent with prudent banking practices and are within applicable banking regulations. Further details relating to certain related party transactions are outlined below: Lending Activities The following information represents annual activity of loans to related parties for the periods indicated: 2017 2016 (Dollars in thousands) Principal balance of loans outstanding at beginning of year $ 22,795 $ 24,653 Loan advances (1) 36,800 1,718 Loan payments/payoffs (7,137 ) (3,576 ) Principal balance of loans outstanding at end of year $ 52,458 $ 22,795 (1) Includes $31.3 million of loans associated with a newly appointed director during the year, which represent the outstanding loan balances at the effective date of appointment. At December 31, 2017 and 2016 , there were no loans to related parties which were past due, on nonaccrual status or that had been restructured as part of a troubled debt restructuring. Deposits At December 31, 2017 and 2016 , the amount of deposit balances of related parties totaled $18.3 million and $14.7 million , respectively. Lease Commitments There were no leases with related parties during the years ended December 31, 2017 , 2016 and 2015 .

SUMMARY OF SIGNIFICANT ACCOUN30

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
PRINCIPLES OF CONSOLIDATION	The consolidated financial statements include the accounts of the Company, the Bank and other wholly-owned subsidiaries, except subsidiaries that are not deemed necessary to be consolidated. All significant intercompany balances and transactions have been eliminated in consolidation. The Company determines whether it has a controlling financial interest in an entity by first evaluating whether the entity is a voting interest entity or a variable interest entity under GAAP. Voting interest entities are entities in which the total equity investment at risk is sufficient to enable the entity to finance itself independently and provides the equity holders with the obligation to absorb losses, the right to receive residual returns and the right to make decisions about the entity’s activities. The Company would consolidate voting interest entities in which it has all, or at least a majority of, the voting interest. As defined in applicable accounting standards, variable interest entities (“VIEs”) are entities that lack one or more of the characteristics of a voting interest entity. A controlling financial interest in a VIE is present when the Company has both the power and ability to direct the activities of the VIE that most significantly impact the VIE's economic performance and an obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The Company also owns the common stock of various trusts which have issued trust preferred securities. These trusts are VIEs in which the Company is not the primary beneficiary and, therefore, are not consolidated. The trust's only assets are junior subordinated debentures issued by the Company, which were acquired by the trust using the proceeds from the issuance of the trust preferred securities and common stock. The junior subordinated debentures are included in long-term debt and the Company’s equity interest in the trust is included in other assets in the accompanying Consolidated Balance Sheets. Interest expense on the junior subordinated debentures is reported in interest expense on long-term debt in the accompanying Consolidated Statements of Income.
RECLASSIFICATION	Reclassification Certain previously reported amounts have been reclassified to conform to the current year’s presentation.
USE OF ESTIMATES	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could vary from these estimates. Material estimates that are particularly susceptible to significant changes in the near-term relate to the determination of the allowance for loan losses, income taxes, valuation and potential impairment of investment securities, other-than-temporary impairment (“OTTI”) of certain investment securities, as well as valuation of goodwill and other intangibles and their respective analyses of impairment.
SIGNIFICANT CONCENTRATIONS OF CREDIT RISK	Significant Concentrations of Credit Risk The vast majority of the Bank’s lending activities are conducted in the Commonwealth of Massachusetts and Rhode Island. The Bank originates commercial and industrial loans, commercial and residential real estate loans, including construction loans, small business loans, home equity loans, and other consumer loans for its portfolio. The Bank considers a concentration of credit to a particular industry to exist when the aggregate credit exposure which includes direct, indirect or contingent obligations to a borrower, an affiliated group of borrowers or a nonaffiliated group of borrowers engaged in one industry, exceeds 10% of the Bank’s loan portfolio. Loans originated by the Bank to lessors of nonresidential buildings represented 15.4% of the total loan portfolio at both December 31, 2017 and 2016 , respectively. Within this concentration category, the Company believes it is well diversified among collateral property types and tenant industries.
CASH AND CASH EQUIVALENTS	Cash and Cash Equivalents For purposes of reporting cash flows, cash and cash equivalents may include cash on hand, amounts due from banks, inclusive of interest-earning deposits held at banks, and federal funds sold. Generally, federal funds are sold for up to two week periods.
SECURITIES	Investment securities are classified at the time of purchase as “available for sale,” “held to maturity,” or “trading.” Classification is constantly re-evaluated for consistency with corporate goals and objectives. Trading securities are recorded at fair value with subsequent changes in fair value recorded in earnings. Debt securities that management has the positive intent and ability to hold to maturity are classified as “held to maturity” and recorded at amortized cost. Securities not classified as held to maturity or trading, including equity securities with readily determinable fair values, are classified as “available for sale” and recorded at fair value, with changes in fair value excluded from earnings and reported in other comprehensive income, net of related tax. Purchase premiums and discounts are recognized in interest income, using the interest method, to arrive at periodic interest income at a constant effective yield, thereby reflecting the securities market yield. Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method. Declines in the fair value of held to maturity and available for sale securities below their amortized cost deemed to be OTTI are written down to fair value as determined by a cash flow analysis. To the extent the estimated cash flows do not support the amortized cost, the deficiency is considered to be due to credit loss and recognized in earnings. Unless the Company intends to sell the security, or if it is more likely than not that the Company will be required to sell the debt security before its anticipated recovery, the remainder of the OTTI charge is considered to be due to other factors, such as liquidity or interest rates, and thus is not recognized in earnings, but rather through other comprehensive income, net of related tax. The Company evaluates individual securities that have fair values below cost for six months or longer, or for a shorter period of time if considered appropriate by management, to determine if the decline in fair value is other-than-temporary. Consideration is given to the obligor of the security, whether the security is guaranteed, whether there is a projected adverse change in cash flows, the liquidity of the security, the type of security, the capital position of security issuers, and payment history of the security, amongst other factors when evaluating such securities.
LOANS HELD FOR SALE	Loans Held for Sale The Bank primarily classifies new residential real estate mortgage loans as held for sale based on intent, which is determined when loans are underwritten. Residential real estate mortgage loans not designated as held for sale are retained based upon available liquidity, for interest rate risk management and other business purposes. The Company has elected the fair value option to account for originated closed loans intended for sale. Accordingly, changes in fair value relating to loans intended for sale are recorded in earnings and are offset by changes in fair value relating to interest rate lock commitments and forward sales commitments. Gains and losses on residential loan sales (sales proceeds minus carrying amount) are recorded in mortgage banking income. Upfront costs and fees related to items for which the fair value option is elected are recognized in earnings as incurred and are not deferred.
LOANS	Loans Loans are carried at the principal amounts outstanding, or amortized acquired fair value in the case of acquired loans, adjusted by partial charge-offs and net of deferred loan costs or fees. For originated loans, loan fees and certain direct origination costs are deferred and amortized into interest income over the expected term of the loan using the level-yield method. When a loan is paid off, the unamortized portion is recognized in interest income. Interest income on loans is accrued based upon the daily principal amount outstanding except for loans on nonaccrual status. For acquired loans which did not show signs of credit deterioration at acquisition, interest income is also accrued based upon the daily principal amount outstanding and is then further adjusted by the accretion of any discount or amortization of any premium associated with the loan. As a general rule, loans more than 90 days past due with respect to principal or interest are classified as nonaccrual loans, or sooner if management considers such action to be prudent. However, loans that are more than 90 days past due may be kept on an accruing status if the loan is well secured and in the process of collection. The Company may also put a junior lien mortgage on nonaccrual status as a result of delinquency with respect to the first position, which is held by the Bank or by another financial institution, while the junior lien is currently performing. Income accruals are suspended on all nonaccrual loans and all previously accrued and uncollected interest is reversed against current income. A loan remains on nonaccrual status until it becomes current with respect to principal and interest (and in certain instances remains current for up to six months), the loan is liquidated, or when the loan is determined to be uncollectible and is charged-off against the allowance for loan losses. When doubt exists as to the collectability of a loan, any payments received are applied to reduce the recorded investment in the asset to the extent necessary to eliminate such doubt. For all loan portfolios, a charge-off occurs when the Company determines that a specific loan, or portion thereof, is uncollectible. This determination is made based on management's review of specific facts and circumstances of the individual loan, including assessing the viability of the customer’s business or project as a going concern, the expected cash flows to repay the loan, the value of the collateral and the ability and willingness of any guarantors to perform. In cases where a borrower experiences financial difficulties and the Company makes certain concessionary modifications to contractual terms, the loan is classified as a troubled debt restructuring (“TDR”). Modifications may include adjustments to interest rates, extensions of maturity, consumer loans where the borrower's obligations have been effectively discharged through Chapter 7 Bankruptcy and the borrower has not reaffirmed the debt to the Bank, and other actions intended to minimize economic loss and avoid foreclosure or repossession of collateral. The recorded investment of loans classified as TDRs is adjusted to reflect the changes in value, if any, resulting from the granting of a concession. Nonaccrual loans that are restructured remain on nonaccrual for a period of six months to demonstrate that the borrower can meet the restructured terms. If the restructured loan is on accrual status prior to being modified, it is reviewed to determine if the modified loan should remain on accrual status. If the borrower’s ability to meet the revised payment schedule is not reasonably assured, the loan is classified as a nonaccrual loan. Loans classified as TDRs remain classified as such for the life of the loan, except in limited circumstances, when it is determined that the borrower is performing under the modified terms and the restructuring agreement specified an interest rate greater than or equal to an acceptable market rate for a comparable new loan at the time of the restructuring
ACQUIRED LOANS	Acquired loans All acquired loans are recorded at fair value with no carryover of the allowance for loan losses. At acquisition, loans are also reviewed to determine if the loan has evidence of deterioration in credit quality and to review if it is probable, at acquisition, that all contractually required payments will not be collected. Such loans are deemed to be purchased credit impaired ("PCI") loans. Under the accounting model for PCI loans, the excess of cash flows expected to be collected over the carrying amount of the loans, referred to as the "accretable yield", is accreted into interest income over the life of the loans using the effective yield method. Accordingly, PCI loans are not subject to classification as nonaccrual in the same manner as originated loans. Rather, acquired loans are generally considered to be accruing loans because their interest income relates to the accretable yield recognized and not to contractual interest payments at the loan level. The difference between contractually required principal and interest payments and the cash flows expected to be collected, referred to as the "nonaccretable difference", includes estimates of both the impact of prepayments and future credit losses expected to be incurred over the life of the loans. The estimate of cash flows expected to be collected is regularly re-assessed subsequent to acquisition. These re-assessments involve updates, as necessary, of the key assumptions and estimates used in the initial estimate of fair value. Generally speaking, expected cash flows are affected by: • Changes in the expected principal and interest payments over the estimated life - Changes in expected cash flows may be driven by the credit outlook and actions taken with borrowers. Changes in expected future cash flows resulting from loan modifications are included in the assessment of expected cash flows. • Change in prepayment assumptions - Prepayments affect the estimated life of the loans, which may change the amount of interest income expected to be collected. • Change in interest rate indices for variable rate loans - Expected future cash flows are based, as applicable, on the variable rates in effect at the time of the assessment of expected cash flows. A decrease in expected cash flows in subsequent periods may indicate that the loan is impaired which would likely require the recognition of a charge-off against the allowance for loan losses or an establishment of a specific reserve. An increase in expected cash flows in subsequent periods serves, first, to reduce any previously established specific reserve by the increase in the present value of cash flows expected to be collected. Any increase above the previously established specific reserve results in a recalculation of the amount of accretable yield for the loan. The adjustment of accretable yield due to an increase in expected cash flows is accounted for as a change in estimate. The additional cash flows expected to be collected are reclassified from the nonaccretable difference to the accretable yield, and the amount of periodic accretion is adjusted accordingly over the remaining life of the loans. A PCI loan may be resolved either through receipt of payment (in full or in part) from the borrower, the sale of the loan to a third party, or foreclosure of the collateral. In the event of a sale of the loan, a gain or loss on sale would be recognized and reported within noninterest income based on the difference between the sales proceeds and the carrying amount of the loan. For PCI loans accounted for on an individual loan basis and resolved directly with the borrower, any amount received from resolution in excess of the carrying amount of the loan is recognized and reported within interest income. A refinancing or modification of a PCI loan accounted for individually is assessed to determine whether the modification represents a TDR. If the loan is considered to be a TDR, it will be included in the total impaired loans reported by the Company. The loan will continue to recognize interest income based upon the excess of cash flows expected to be collected over the carrying amount of the loan.
ALLOWANCE FOR LOAN LOSSES	Allowance for Loan Losses The allowance for loan losses is established based upon the level of estimated probable losses in the current loan portfolio. Loan losses are charged against the allowance when management believes the collectability of a loan balance is doubtful. Subsequent recoveries, if any, are credited to the allowance. The allowance for loan losses is allocated to loan types using both a formula-based approach applied to groups of loans and an analysis of certain individual loans for impairment. The formula-based approach emphasizes loss factors derived from actual historical portfolio loss rates, which are combined with an assessment of certain qualitative factors to determine the allowance amounts allocated to the various loan categories. Allowance amounts are determined based on an estimate of the historical average annual percentage rate of loan loss for each loan category, an estimate of the incurred loss emergence and confirmation period for each loan category, and certain qualitative risk factors considered in the computation of the allowance for loan losses. The qualitative risk factors impacting the inherent risk of loss within the portfolio include the following: • National and local economic and business conditions • Level and trend of delinquencies • Level and trend of charge-offs and recoveries • Trends in volume and terms of loans • Risk selection, lending policy and underwriting standards • Experience and depth of management • Banking industry conditions and other external factors • Concentration risk The formula-based approach evaluates groups of loans with common characteristics, which consist of similar loan types with similar terms and conditions, to determine the appropriate allocation within each portfolio section. This approach incorporates qualitative adjustments based upon management’s assessment of various market and portfolio specific risk factors into its formula-based estimate. Due to the imprecise nature of the loan loss estimation process and ever changing conditions, the qualitative risk attributes may not adequately capture amounts of incurred loss in the formula-based loan loss components used to determine the Bank’s analysis of the appropriateness of the allowance for loan losses. The Bank evaluates certain loans within the commercial and industrial, commercial real estate, commercial construction and small business portfolios individually for specific impairment. A loan is considered impaired when, based on current information and events, it is probable that the Bank will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, contractual interest rates and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Loans are selected for evaluation based upon a change in internal risk rating, occurrence of delinquency, loan classification, troubled debt restructuring or nonaccrual status. A specific allowance amount is allocated to an individual loan when such loan has been deemed impaired and when the amount of the probable loss is able to be estimated. Estimates of loss may be determined by the present value of anticipated future cash flows, the loan’s observable fair market value, or the fair value of the collateral, if the loan is collateral dependent. However, for collateral dependent loans, the amount of the recorded investment in a loan that exceeds the fair value of the collateral less costs to sell is charged-off against the allowance for loan losses in lieu of an allocation of a specific allowance amount when such an amount has been identified definitively as uncollectible. Large groups of small-balance homogeneous loans such as the residential real estate, residential construction, home equity and other consumer portfolios are collectively evaluated for impairment. As such, the Bank does not typically identify individual loans within these groupings as impaired loans for impairment evaluation and disclosure. However, the Bank evaluates all TDRs for impairment on an individual loan basis regardless of loan type. In the ordinary course of business, the Bank enters into commitments to extend credit, commercial letters of credit, and standby letters of credit. Such financial instruments are recorded in the financial statements when they become payable. The credit risk associated with these commitments is evaluated in a manner similar to the allowance for loan losses. The reserve for unfunded lending commitments is included in other liabilities in the balance sheet. At December 31, 2017 and 2016 , the reserve for unfunded loan commitments was $972,000 and $954,000 , respectively.
Transfers and Servicing of Financial Assets, Transfers of Financial Assets, Financings, Policy [Policy Text Block]	Transfers and Servicing of Financial Assets Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from the Company, (2) the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (3) the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. Loans held for sale are generally sold with servicing rights released, however if rights are retained, servicing assets are recognized as separate assets. Servicing rights are originally recorded at fair value within other assets, but subsequently are amortized in proportion to and over the period of estimated net servicing income, and are assessed for impairment at each reporting date. Fair value is based on market prices for comparable mortgage servicing contracts, when available, or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income. The valuation model incorporates assumptions that market participants would use in estimating future net servicing income, such as the cost to service, the discount rate, the custodial earnings rate, an inflation rate, ancillary income, prepayment speeds, default rates and losses. Impairment is determined by stratifying the rights based on predominant characteristics, such as interest rate, loan type and investor type. Impairment is recognized through a valuation allowance, to the extent that fair value is less than the capitalized amount. If the Company later determines that all or a portion of the impairment no longer exists, a reduction of the allowance may be recorded as an increase to income. Servicing fee income is recorded for fees earned for servicing loans for investors. The fees are based on a contractual percentage of the outstanding principal or a fixed amount per loan, and are recorded as income when earned. The amortization of mortgage servicing rights is recorded as a reduction of loan servicing fee income.
FEDERAL HOME LOAN BANK STOCK	Federal Home Loan Bank Stock The Company, as a member of the Federal Home Loan Bank (“FHLB”) of Boston, is required to maintain an investment in capital stock of the FHLB. Based on redemption provisions, the stock has no quoted market value and is carried at cost. The Company continually reviews its investment to determine if OTTI exists. The Company reviews recent public filings, rating agency analysis and other factors, when making its determination.
BANK PREMISES AND EQUIPMENT	Bank Premises and Equipment Land is carried at cost. Bank premises and equipment are stated at cost less accumulated depreciation. Depreciation is computed using the straight-line convention method over the estimated useful lives of the assets. Leasehold improvements are amortized over the shorter of the lease terms or the estimated useful lives of the improvements. Expected terms include lease option periods to the extent that the exercise of such options is reasonably assured, not to exceed fifteen years.
GOODWILL AND IDENTIABLE INTANGIBLE ASSETS	Goodwill and Other Intangible Assets Goodwill represents the excess of the purchase price over the net fair value of acquired businesses. Goodwill is not amortized and is assigned to one reporting unit. Goodwill is evaluated for impairment at least annually, or more often if warranted, using a combined qualitative and quantitative impairment approach. The initial qualitative approach assesses whether the existence of events or circumstances led to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events and circumstances, the Company determines it is more likely than not that the fair value is less than carrying value, the two step quantitative impairment test is performed. Step one of the quantitative impairment test compares book value to the fair value of the reporting unit. If step one is failed, a detailed step two analysis is performed, which involves measuring the excess of the fair value of the reporting unit, as determined in step one, over the aggregate fair value of the individual assets, liabilities, and identifiable intangibles as if the reporting unit was being acquired in a business combination. Other intangible assets subject to amortization consist of core deposit intangibles, noncompete agreements, customer lists and market-based favorable or unfavorable lease positions at time of acquisition, and are amortized over the estimated lives of the intangibles using a method that approximates the amount of economic benefits that are realized by the Company. Other intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. The range of useful lives is as follows: Core deposit intangibles 10 years Noncompete agreements 1-3 years Leases 3-29 years The determination of which intangible assets have finite lives is subjective, as is the determination of the amortization period for such intangible assets.
IMPAIRMENT OF LONG-LIVED ASSETS OTHER THAN GOODWILL	Impairment of Long-Lived Assets Other Than Goodwill The Company reviews long-lived assets, including premises and equipment, for impairment whenever events or changes in business circumstances indicate that the remaining useful life may warrant revision or that the carrying amount of the long-lived asset may not be fully recoverable. The Company performs undiscounted cash flow analysis to determine if impairment exists. 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.
CASH SURRENDER VALUE OF LIFE INSURANCE POLICIES	Cash Surrender Value of Life Insurance Policies Increases in the cash surrender value (“CSV”) of life insurance policies, as well as benefits received net of any CSV, are recorded in other noninterest income, and are not subject to income taxes. The CSV of the policies is recorded as an asset of the Bank, with liabilities recognized for any split dollar arrangements associated with the policies. The Company reviews the financial strength of the insurance carriers prior to the purchase of life insurance policies and no less than annually thereafter. Regulatory requirements limit the total amount of CSV to be held with any individual carrier to 15% of Tier 1 capital (as defined for regulatory purposes) and the total CSV of all life insurance policies is limited to 25% of Tier 1 capital.
OTHER REAL ESTATE OWNED AND OTHER FORECLOSED ASSETS	and Other Foreclosed Assets Real estate properties and other assets, which have served as collateral to secure loans, are held for sale and are initially recorded at fair value less estimated costs to sell at the date control is established, resulting in a new cost basis. The amount by which the recorded investment in the loan exceeds the fair value (net of estimated costs to sell) of the foreclosed asset is charged to the allowance for loan losses. Subsequent declines in the fair value of the foreclosed asset below the new cost basis are recorded through the use of a valuation allowance. Subsequent increases in the fair value are recorded as reductions in the valuation allowance, but not below zero. Upon a sale of a foreclosed asset, any excess of the carrying value over the sale proceeds is recognized as a loss on sale. Any excess of sale proceeds over the carrying value of the foreclosed asset is first applied as a recovery to the valuation allowance, if any, with the remainder being recognized as a gain on sale. Operating expenses and changes in the valuation allowance relating to foreclosed assets are included in other noninterest expense.
Repurchase and Resale Agreements Policy [Policy Text Block]	Customer Repurchase Agreements In a security repurchase agreement transaction, the Company will generally sell a security, agreeing to repurchase either the same or substantially identical security on a specified later date, at a greater price than the original sales price. The difference between the sale price and purchase price is the cost of the proceeds, which is recorded as interest expense. The securities underlying the agreements are delivered to counterparties as security for the repurchase obligations. Since the securities are treated as collateral and the agreement does not qualify for a full transfer of effective control, the transactions do not meet the criteria to be classified as a sale, and are therefore considered a secured borrowing transaction for accounting purposes.
DERIVATIVES	Derivatives Derivative instruments are carried at fair value in the Company’s financial statements. The accounting for changes in the fair value of a derivative instrument is determined by whether it has been designated and qualifies as part of a hedging relationship, and further, by the type of hedging relationship. At the inception of a hedge, the Company documents certain items, including but not limited to the following: the relationship between hedging instruments and hedged items, the Company's risk management objectives, hedging strategies, and the evaluation of hedge transaction effectiveness. Documentation includes linking all derivatives designated as fair value or cash flow hedges to specific assets and liabilities on the balance sheet or to specific forecasted transactions. For those derivative instruments that are designated and qualify for special hedge accounting, the Company designates the hedging instrument, based upon the exposure being hedged, as either a fair value hedge or a cash flow hedge. For derivative instruments that are designated and qualify as a cash flow hedge (i.e., hedging the exposure to variability in expected future cash flows that is attributable to a particular risk), the effective portion of the gain or loss on the derivative instrument is reported as a component of other comprehensive income, net of related tax, and reclassified into earnings in the same period or periods during which the hedged transactions affect earnings. The remaining gain or loss on the derivative instrument in excess of the cumulative change in the present value of future cash flows of the hedged item (i.e., the ineffective portion), if any, is recognized in current earnings during the period. For derivative instruments designated and qualifying as a fair value hedge (i.e., hedging the exposure to changes in the fair value of an asset or liability or an identified portion thereof that is attributable to the hedged risk), the gain or loss on the derivative instrument, as well as the offsetting gain or loss on the hedged item attributable to the hedged risk, are recognized in current earnings during the period of the change in fair values. Hedge accounting is discontinued prospectively when (1) a derivative is no longer highly effective in offsetting changes in the fair value or cash flow of a hedged item, (2) a derivative expires or is settled, (3) it is no longer likely that a forecasted transaction associated with the hedge will occur, or (4) it is determined that designation of a derivative as a hedge is no longer appropriate. To the extent the Company enters into new or re-designates existing hedging relationships, it is the Company's policy to include the Overnight Index Swap Rate in the spectrum of available benchmark interest rates for hedge accounting. For derivative instruments not designated as hedging instruments, such as loan level derivatives, foreign exchange contracts and mortgage derivatives, changes in fair value are recognized in other noninterest income during the period of change.
RETIREMENT PLANS	Retirement Plans The Company has various retirement plans in place for current and former employees, including postretirement benefit plans, supplemental executive retirement plans, frozen multiemployer pension plans, deferred compensation plans, as well as other benefits. The postretirement benefit plans and the supplemental executive retirement plans are unfunded and therefore have no plan assets. The actuarial cost method used to compute the benefit liabilities and related expense is the projected unit credit method. The projected benefit obligation is principally determined based on the present value of the projected benefit distributions at an assumed discount rate. The discount rate which is utilized is based on the investment yield of high quality corporate bonds available in the market place with maturities approximately equal to projected cash flows of future benefit payments as of the measurement date. Periodic benefit expense (or income) includes service costs and interest costs based on the assumed discount rate, amortization of prior service costs due to plan amendments and amortization of actuarial gains and losses. The amortization of actuarial gains and losses is determined using the 10% corridor minimum amortization approach and is taken over the average remaining future working lifetime of the plan participants. The underfunded status of the plans is recorded as a liability on the balance sheet. The multiemployer pension plans' assets are determined based on fair value, generally representing observable market prices. The actuarial cost method used to compute the pension liabilities and related expense is the unit credit method. The pension expense is equal to the plan contribution requirement of the Company for the plan year. The Director Deferred Compensation and 401(k) Restoration plans allow directors and employees to invest their funds within a rabbi trust, including both Company stock and other investment alternatives offered by the plan. The plans do not permit diversification after initial election and therefore elections made to defer into Company stock result in both the investment and obligation recognized within Stockholders' Equity. Alternatively, investments not in Company stock are included in Securities-trading, with the correlating obligation classified as a liability. The Company has obligations with various individuals related to certain post-retirement benefits. The obligations are based on the individual's service through retirement, with the associated cost recognized over the requisite service period. The accrual methodology results in an accrued amount at the full eligibility date equal to the then present value of all of the future benefits expected to be paid.
STOCK-BASED COMPENSATION	Stock-Based Compensation The Company recognizes stock-based compensation based on the grant-date fair value of the award, with no adjustment for estimated forfeitures, as forfeitures are recognized when they occur. For restricted stock awards and units, the Company recognizes compensation expense ratably over the vesting period for the fair value of the award, measured at the grant date. For stock option awards, the Company values awards granted using the Black-Scholes option-pricing model. The Company recognizes compensation expense for these awards on a straight-line basis over the requisite service period for the entire award (straight-line attribution method), ensuring that the amount of compensation cost recognized at any date at least equals the portion of the grant-date fair value of the award that is vested at that time.
INCOME TAXES	Income Taxes Deferred income tax assets and liabilities are determined using the asset and liability (or balance sheet) method of accounting for income taxes. Under this method, 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. If current available information raises doubt as to the realization of the deferred tax assets, a valuation allowance is established. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in enacted tax rates is recognized in income in the period that includes the enactment date. Income taxes are allocated to each entity in the consolidated group based on its share of taxable income. Management exercises significant judgment in evaluating the amount and timing of recognition of the resulting tax liabilities and assets, including projections of future taxable income. Additionally, a liability for unrecognized tax benefits is recorded for uncertain tax positions taken by the Company on its tax returns for which there is less than a 50% likelihood of being recognized upon a tax examination. Tax credits generated from the New Markets Tax Credit program are reflected in earnings when realized for federal income tax purposes.
Low Income Housing Tax Credits Policy Text Block [Policy Text Block]	Low Income Housing Tax Credits The Company accounts for its investments in qualified affordable housing projects using the proportional amortization method. Under the proportional amortization method the Company amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received, and recognizes the net investment benefit as a component of income tax expense (benefit).
ASSETS UNDER ADMININSTRATION	Assets Under Administration Assets held in a fiduciary or agency capacity for customers are not included in the accompanying consolidated balance sheet, as such assets are not assets of the Company. Revenue from administrative and management activities associated with these assets is recorded on an accrual basis.
Extinguishment of Debt [Policy Text Block]	Extinguishment of Debt Upon extinguishment of an outstanding debt, the Company records the difference between the exit price and the net carrying amount of the debt as a gain or loss on the extinguishment. The gain or loss is recorded as a component of other noninterest income or other noninterest expense, respectively.
EARNINGS PER SHARE	Earnings Per Share Basic earnings per share is calculated using the two-class method. The two-class method is an earnings allocation formula under which earnings per share is calculated from common stock and participating securities according to dividends declared and participation rights in undistributed earnings. Under this method, all earnings distributed and undistributed, are allocated to participating securities and common shares based on their respective rights to receive dividends. Unvested share-based payment awards that contain nonforfeitable rights to dividends are considered participating securities (i.e. unvested time-vested restricted stock), not subject to performance based measures. Basic earnings per share is calculated by dividing net income by the weighted average number of common shares outstanding (inclusive of participating securities). Diluted earnings per share have been calculated in a manner similar to that of basic earnings per share except that the weighted average number of common shares outstanding is increased to include the number of additional common shares that would have been outstanding if all potentially dilutive common shares (such as those resulting from the exercise of stock options or the attainment of performance measures) were issued during the period, computed using the treasury stock method.
COMPREHENSIVE INCOME	Comprehensive Income Comprehensive income consists of net income and other comprehensive income. Other comprehensive income includes unrealized gains and losses on securities available for sale, unrealized losses related to factors other than credit on debt securities, if applicable, unrealized gains and losses on cash flow hedges, deferred gains on hedge accounting transactions, and changes in the funded status of the Company’s postretirement and supplemental retirement plans.
FAIR VALUE MEASUREMENTS	Fair Value Measurements In general, fair values of financial instruments are based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments may include amounts to reflect counterparty credit quality and the Company’s creditworthiness, among other things, as well as unobservable parameters.
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Standards Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") Topic 718 "Compensation - Stock Compensation" Update No. 2016-09. Update No. 2016-09 was issued in March 2016 and affects all entities that issue share-based awards to their employees. This update was issued as part of the FASB’s simplification initiative. The areas for simplification in this update involve several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The amendments in this update are effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. The Company adopted this standard effective January 1, 2017. Upon adoption, the Company elected to no longer estimate forfeitures on stock compensation and instead recognize forfeitures when they occur. The election required a cumulative effect adjustment to retained earnings which did not materially impact the Company's consolidated financial position. Additionally, the disclosure requirements of this standard will be applied on a prospective basis. FASB ASC Topic 230 "Statement of Cash Flows" Update No. 2016-15. Update No. 2016-15 was issued in August 2016 to reduce diversity of practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The amendments in this update provide guidance on the following eight specific cash flow issues; (1) debt prepayment or debt extinguishment costs, (2) settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, (3) contingent consideration payments made after a business combination, (4) proceeds from the settlement of insurance claims, (5) proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies, (6) distributions received from equity method investees, (7) beneficial interests in securitization transactions, and (8) separately identifiable cash flows and application of the predominance principle. The amendments in this topic will provide guidance for these eight issues, thereby reducing the current and potential future diversity in practice. The Company adopted this standard effective January 1, 2018 and the impact on the Company's consolidated financial position was immaterial. FASB ASC Topic 220 "Reporting Comprehensive Income" Update No. 2018-02. Updated No. 2018-02 was issued in February 2018 to allow a reclassification from accumulated other comprehensive income to retained earnings for amounts considered to be stranded in other comprehensive income as are result of the Tax Cuts and Jobs Act ("Tax Act"). These amendments eliminate these stranded tax effects and will improve the usefulness of information reported to financial statement users. However, because these amendments only relate to the reclassification of the income tax effects of the Tax Act, the underlying guidance that requires that the effect of a change in tax laws or rates be included in income from continuing operations is not affected. The amendments in this update also require certain disclosures about stranded tax effects. The amendments in this update are effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. The Company adopted this standard effective January 1, 2018. The adoption of this standard did not have a material impact on the Company's consolidated financial position. FASB ASC Topic 815 "Derivatives and Hedging" Update No. 2017-12. Update No. 2017-12 was issued in August 2017 to better align an entity's risk management activities and financial reporting for hedging relationships through changes to both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results. To meet that objective, the amendments expand and refine hedge accounting for both nonfinancial and financial risk components and align the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. The amendments in this update are effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. The Company adopted this standard effective January 1, 2018. The adoption of this standard did not have a material impact on the Company's existing hedging relationships. FASB ASC Topic 718 "Compensation - Stock Compensation" Update No. 2017-09 . Update No. 2017-09 was issued in May 2017 to provide clarity and reduce diversity in practice when applying guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. An entity should account for the effects of a modification unless all the following are met: (1) The fair value (or calculated value or intrinsic value, if such an alternative measurement method is used) of the modified award is the same as the fair value of the original award immediately before the original award is modified. If the modification does not affect any of the inputs to the valuation technique that the entity uses to value the award, the entity is not required to estimate the value immediately before and after the modification. (2) The vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before the original award is modified. (3) The classification of the modified award as an equity instrument or a liability instrument is the same as the classification of the original award immediately before the original award is modified. The current disclosure requirements in Topic 718 apply regardless of whether an entity is required to apply modification accounting under the amendments in this update. The amendments in this update are effective for all entities for annual periods, and interim periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted, including adoption in any interim period, for public business entities for reporting periods for which financial statements have not yet been issued and all other entities for reporting periods for which financial statements have not yet been made available for issuance. The amendments in this update should be applied prospectively to an award modified on or after the adoption date. Upon adoption of this standard on January 1, 2018, there was no material impact on the Company's consolidated financial position. FASB ASC Topic 310-20 "Receivables - Nonrefundable fees and Other Costs" Update No. 2017-08. Update No. 2017-08 was issued in March 2017 to shorten the amortization period for certain callable debt securities held at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. The amendments in this update are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted, including adoption in an interim period. The Company early adopted this standard effective January 1, 2017 and the impact on the Company's consolidated financial position was immaterial. FASB ASC Topic 715 "Compensation - Retirement Benefits" Update No. 2017-07 . Update No. 2017-07 was issued in March 2017 to improve the presentation of net periodic pension cost and net periodic postretirement benefit costs. This update requires that an employer report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. If a separate line item or items are used to present the other components of net benefit cost, that line item or items must be appropriately described. If a separate line item or items are not used, the line item or items used in the income statement to present the other components of net benefit cost must be disclosed. The amendments in this update also allow only the service cost component to be eligible for capitalization when applicable. The amendments in this update are effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods. Early adoption is permitted as of the beginning of an annual period for which the financial statements (interim or annual) have not been issued or made available for issuance. That is, early adoption should be within the first interim period if an employer issues interim financial statements. Disclosures of the nature of and reason for the change in accounting principle are required in the first interim and annual periods of adoption. Upon adoption of this standard on January 1, 2018, there was no material impact on the Company's consolidated financial position. FASB ASC Subtopic 610-20 "Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets" Update No. 2017-05. Update No. 2017-05 was issued in February 2017 to clarify that a financial asset is within the scope of Subtopic 610-20 if it meets the definition of an in substance nonfinancial asset. The amendments define the term in substance nonfinancial asset, in part, as a financial asset promised to a counterparty in a contract if substantially all of the fair value of the assets (recognized and unrecognized) that are promised to the counterparty in the contract is concentrated in nonfinancial assets. The amendments in this update also clarify that nonfinancial assets within the scope of Subtopic 610-20 may include nonfinancial assets transferred within a legal entity to a counterparty. A contract that includes the transfer of ownership interests in one or more consolidated subsidiaries is within the scope of Subtopic 610-20 if substantially all of the fair value of the assets that are promised to the counterparty in a contract is concentrated in nonfinancial assets. For purposes of that evaluation, the amendments require an entity to evaluate the underlying assets in consolidated subsidiaries to determine whether those assets are within the scope of Subtopic 610-20. The amendments are effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. The guidance may be applied earlier but only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods in that reporting period. Upon adoption of this standard on January 1, 2018, there was no material impact on the Company's consolidated financial position. FASB ASC Topic 350 "Intangibles - Goodwill and Other " Update No. 2017-04. Update No. 2017-04 was issued in January 2017 to simplify the subsequent measurement of goodwill, by eliminating Step 2 for the goodwill impairment test. The amendments in this update modify the concept of impairment from the condition that exists when the carrying amount of a reporting unit exceeds its fair value. An entity is no longer required to determine goodwill impairment by calculating the implied fair value of goodwill by assigning the fair value of a reporting unit to all of its assets and liabilities as if that reporting unit has been acquired in a business combination. An entity should apply the amendments in this update on a prospective basis. An entity is required to disclose the nature of and reason for the change in accounting principle upon transition. That disclosure should be provided in the first annual period and in the interim period within the first annual period when the entity initially adopts the amendments in this update. A public business entity that is a U.S. Securities and Exchange Commission (SEC)filer should adopt the amendments in this Update for its annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The adoption of this standard is not expected to have a material impact on the Company's consolidated financial position. FASB ASC Topic 606 "Revenue from Contracts with Customers" Update No. 2014-09. Update No. 2014-09 was issued in May 2014 to address the previous revenue recognition requirements in GAAP that differ from those in International Financial Reporting Standards (IFRS). Accordingly, the FASB and the International Accounting Standards Board (IASB) initiated a joint project to clarify the principles for recognizing revenue and to develop a common revenue standard for U.S. GAAP and IFRS. The largely converged revenue recognition standards will supersede virtually all revenue recognition guidance in GAAP and IFRS. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Since the issuance of Update 2014-09, the FASB has finalized various amendments to the standard as summarized below: FASB ASC Topic 606 "Revenue from Contracts with Customers" Update No. 2016-20 FASB ASC Topic 606 "Revenue from Contracts with Customers" Update No. 2016-12 FASB ASC Topic 606 "Revenue from Contracts with Customers" Update No. 2016-10 FASB ASC Topic 606 "Revenue from Contracts with Customers" Update No. 2016-08 . FASB ASC Topic 606 "Revenue from Contracts with Customers" Update No. 2015-14. The amendments in Update 2016-20 make minor corrections or minor improvements to the codification that are not expected to have a significant effect on current accounting practice or create a significant administrative cost to most entities. Through Updates 2016-12, 2016-10 and 2016-08, the FASB amended its new revenue guidance on licenses of intellectual property, identification of performance obligations, collectability, noncash consideration and the presentation of sales and other similar taxes. The FASB also clarified the definition of a completed contract at transition and added a practical expedient to ease transition for contracts that were modified prior to adoption. The FASB also amended the new revenue recognition guidance on determining whether an entity is a principal or an agent in an arrangement which affects whether revenue should be reported gross or net. Following the issuance of Update 2015-14, Update 2014-09, as amended, is effective for the Company for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Earlier adoption is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. A full or modified retrospective transition method is required. The Company's revenue is comprised of net interest income on financial assets and liabilities, and noninterest income. Interest income, mortgage banking income, gain on sale of equity securities, increase in cash surrender value of life insurance policies and loan level derivative income are accounted for under other U.S. GAAP standards, and are therefore out of scope of the ASC 606 revenue standard. Deposit account fees, interchange and ATM fees, investment management and certain categories of other noninterest income are within the scope of the ASC 606 revenue standard. The Company has adopted the revenue recognition standard as of January 1, 2018 and is using the modified retrospective transition method upon adoption. The Company completed its review of relevant contracts related to these revenue streams and determined that there were no material changes to be made to revenue recognition upon adoption. FASB ASC Topic 326 "Financial Instruments - Credit Losses" Update No. 2016-13. Update No. 2016-13 was issued in June 2016 to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in this update replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The amendments affect entities holding financial assets and net investment in leases that are not accounted for at fair value through net income. The amendments affect loans, debt securities, trade receivables, net investments in leases, off-balance sheet credit exposures, reinsurance receivables, and any other financial assets not excluded from the scope that have the contractual right to receive cash. The amendments in this update are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with earlier adoption permitted as of fiscal years beginning after December 15, 2018, including interim periods with those fiscal years. The Company is currently assessing the impact of the adoption of this standard on the Company's consolidated financial position. FASB ASC Topic 842 "Leases" Update No. 2016-02. Update No. 2016-02 was issued in February 2016 and affects any entity that enters into a lease (as that term is defined in this update), with some specified scope exemptions. The core principle of this update is that a lessee should recognize in the statement of financial position a liability to make lease payments and a right-of-use asset representing its right to use the underlying asset for the lease term. For leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. The recognition, measurement, and presentation of expenses and cash flows arising from a lease have not significantly changed from previous GAAP. In addition, the accounting applied by a lessor is largely unchanged from that applied under previous GAAP. For public companies, the amendments in this update are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is currently in the process of reviewing its current lease agreements to assess the impact of the adoption of this standard.

SUMMARY OF SIGNIFICANT ACCOUN31

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of Finite-Lived Intangible Asses Useful Lives	The range of useful lives is as follows: Core deposit intangibles 10 years Noncompete agreements 1-3 years Leases 3-29 years The determination of which intangible assets have finite lives is subjective, as is the determination of the amortization period for such intangible assets.

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	12 Months Ended
	Dec. 31, 2017
Business Acquisition [Line Items]
Schedule of Estimated Fair Value of Assets Acquired and Liabilities Assumed	The following table summarizes the estimated fair value of the assets acquired and liabilities assumed as of the date of the acquisition: Net Assets Acquired at Fair Value (Dollars in thousands) Assets Cash $ 9,679 Loans 225,731 Premises and equipment 201 Goodwill 20,443 Core deposit and other intangibles 670 Other assets 19,197 Total assets acquired 275,921 Liabilities Deposits 175,686 Borrowings 51,150 Other liabilities 7,344 Total liabilities assumed 234,180 Purchase price $ 41,741 Additionally, the acquisition method requires the acquirer to recognize the assets acquired and the liabilities assumed at their fair values as of the acquisition date. The following table summarizes the estimated fair value of the assets acquired and liabilities assumed as of the date of the acquisition: Net Assets Acquired at Fair Value (Dollars in thousands) Assets Cash $ 11,137 Loans 155,551 Premises and equipment 5,828 Goodwill 10,280 Core deposit and other intangibles 2,964 Other assets 4,629 Total assets acquired 190,389 Liabilities Deposits 159,580 Borrowings 2,475 Other liabilities 18 Total liabilities assumed 162,073 Purchase price $ 28,316
Business Acquisition, Pro Forma Information [Table Text Block]	The selected pro forma financial information is presented for illustrative purposes only and is not necessarily indicative of the financial results of the combined companies had the acquisition actually been completed at the beginning of the periods presented, nor does it indicate future results for any other interim or full-year period. Years Ended December 31 2017 2016 (Dollars in thousands) Net interest income after provision for loan losses $ 258,017 $ 227,429 Net income 90,025 78,150 The selected pro forma financial information is presented for illustrative purposes only and is not necessarily indicative of the financial results of the combined companies had the acquisition actually been completed at the beginning of the periods presented, nor does it indicate future results for any other interim or full-year period. Years Ended December 31 2016 2015 (Dollars in thousands) Net interest income after provision for loan losses $ 228,927 $ 221,252 Net income $ 80,411 $ 65,623

SECURITIES (Tables)

SECURITIES (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale Securities and Held-to-maturity Securities	The following table presents a summary of the amortized cost, gross unrealized holding gains and losses and fair value of securities available for sale and securities held to maturity for the periods indicated: December 31, 2017 December 31, 2016 Amortized Gross Gross Unrealized Fair Amortized Gross Gross Unrealized Fair (Dollars in thousands) Available for sale securities U.S. government agency securities $ 35,475 $ 86 $ (131 ) $ 35,430 $ 24,006 $ 238 $ — $ 24,244 Agency mortgage-backed securities 214,934 1,897 (1,067 ) 215,764 173,268 2,852 (736 ) 175,384 Agency collateralized mortgage obligations 124,098 78 (2,164 ) 122,012 101,094 106 (1,332 ) 99,868 State, county, and municipal securities 2,237 37 — 2,274 3,743 50 — 3,793 Single issuer trust preferred securities issued by banks 2,012 4 — 2,016 2,311 3 (3 ) 2,311 Pooled trust preferred securities issued by banks and insurers 2,179 — (539 ) 1,640 2,200 — (616 ) 1,584 Small business administration pooled securities 47,852 44 (118 ) 47,778 37,561 — (372 ) 37,189 Equity securities 19,432 1,594 (442 ) 20,584 19,183 641 (553 ) 19,271 Total available for sale securities 448,219 3,740 (4,461 ) 447,498 363,366 3,890 (3,612 ) 363,644 Held to maturity securities U.S. treasury securities 1,006 29 — 1,035 1,007 47 — 1,054 Agency mortgage-backed securities 204,768 1,791 (736 ) 205,823 156,088 2,274 (858 ) 157,504 Agency collateralized mortgage obligations 262,998 397 (4,987 ) 258,408 297,445 1,002 (3,797 ) 294,650 Single issuer trust preferred securities issued by banks 1,500 29 — 1,529 1,500 44 — 1,544 Small business administration pooled securities 27,416 183 (200 ) 27,399 31,036 189 (327 ) 30,898 Total held to maturity securities 497,688 2,429 (5,923 ) 494,194 487,076 3,556 (4,982 ) 485,650 Total $ 945,907 $ 6,169 $ (10,384 ) $ 941,692 $ 850,442 $ 7,446 $ (8,594 ) $ 849,294
Schedule of Contractual Maturities of Securities	A schedule of the contractual maturities of securities available for sale and securities held to maturity as of December 31, 2017 is presented below: Available for Sale Held to Maturity Amortized Fair Amortized Fair (Dollars in thousands) Due in one year or less $ 3,213 $ 3,215 $ — $ — Due after one year to five years 49,241 49,312 15,636 15,711 Due after five to ten years 107,417 107,402 16,801 17,098 Due after ten years 268,916 266,985 465,251 461,385 Total debt securities 428,787 426,914 497,688 494,194 Equity securities 19,432 20,584 — — Total $ 448,219 $ 447,498 $ 497,688 $ 494,194
Schedule of Gross Unrealized Losses and Fair Value of Investments	December 31, 2017 Less than 12 months 12 months or longer Total Description of securities # of Fair Value Unrealized Fair Unrealized Fair Value Unrealized (Dollars in thousands) U.S. government agency securities 4 $ 24,343 $ (131 ) $ — $ — $ 24,343 $ (131 ) Agency mortgage-backed securities 84 $ 235,411 $ (1,493 ) $ 14,886 $ (310 ) $ 250,297 $ (1,803 ) Agency collateralized mortgage obligations 42 178,142 (1,579 ) 159,506 (5,572 ) 337,648 (7,151 ) Pooled trust preferred securities issued by banks and insurers 1 — — 1,640 (539 ) 1,640 (539 ) Small business administration pooled securities 4 34,553 (223 ) 9,647 (95 ) 44,200 (318 ) Equity securities 28 3,290 (39 ) 7,619 (403 ) 10,909 (442 ) Total temporarily impaired securities 163 $ 475,739 $ (3,465 ) $ 193,298 $ (6,919 ) $ 669,037 $ (10,384 ) December 31, 2016 Less than 12 months 12 months or longer Total Description of securities # of Fair Value Unrealized Fair Unrealized Fair Value Unrealized (Dollars in thousands) Agency mortgage-backed securities 57 $ 137,949 $ (1,594 ) $ — $ — $ 137,949 $ (1,594 ) Agency collateralized mortgage obligations 32 243,051 (3,140 ) 47,403 (1,989 ) 290,454 (5,129 ) Single issuer trust preferred securities issued by banks and insurers 1 — — 1,036 (3 ) 1,036 (3 ) Pooled trust preferred securities issued by banks and insurers 1 — — 1,583 (616 ) 1,583 (616 ) Small business administration pooled securities 5 59,846 (699 ) — — 59,846 (699 ) Equity securities 25 3,625 (77 ) 6,334 (476 ) 9,959 (553 ) Total temporarily impaired securities 121 $ 444,471 $ (5,510 ) $ 56,356 $ (3,084 ) $ 500,827 $ (8,594 )

LOANS, ALLOWANCE FOR LOAN LOS34

LOANS, ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY (Tables)	12 Months Ended
	Dec. 31, 2017
Loans, Allowance for Loan Losses and Credit Quality [Abstract]
Schedule of Allowance for Loan Losses	The following table summarizes changes in the allowance for loan losses by loan category and bifurcates the amount of allowance allocated to each loan category based on collective impairment analysis and loans evaluated individually for impairment: December 31, 2017 Commercial Commercial Commercial Small Residential Home Other Consumer Total (Dollars in thousands) Allowance for loan losses Beginning balance $ 16,921 $ 30,369 $ 4,522 $ 1,502 $ 2,621 $ 5,238 $ 393 $ 61,566 Charge-offs (3,891 ) (39 ) — (302 ) (207 ) (276 ) (1,494 ) (6,209 ) Recoveries 615 385 — 114 31 198 993 2,336 Provision (benefit) (389 ) 738 1,176 263 377 230 555 2,950 Ending balance $ 13,256 $ 31,453 $ 5,698 $ 1,577 $ 2,822 $ 5,390 $ 447 $ 60,643 Ending balance: collectively evaluated for impairment $ 13,246 $ 31,411 $ 5,698 $ 1,576 $ 1,815 $ 5,125 $ 430 $ 59,301 Ending balance: individually evaluated for impairment $ 10 $ 42 $ — $ 1 $ 1,007 $ 265 $ 17 $ 1,342 Financing receivables ending balance: Collectively evaluated for impairment $ 853,885 $ 3,093,945 $ 401,797 $ 131,667 $ 733,809 $ 1,045,053 $ 9,573 $ 6,269,729 Individually evaluated for impairment 34,643 16,638 — 703 13,684 6,826 307 72,801 Purchased credit impaired loans — 5,978 — — 6,836 209 — 13,023 Total loans by group $ 888,528 $ 3,116,561 $ 401,797 $ 132,370 $ 754,329 $ 1,052,088 $ 9,880 $ 6,355,553 (1) December 31, 2016 Commercial Commercial Commercial Small Residential Home Other Consumer Total (Dollars in thousands) Allowance for loan losses Beginning balance $ 13,802 $ 27,327 $ 5,366 $ 1,264 $ 2,590 $ 4,889 $ 587 $ 55,825 Charge-offs (593 ) (414 ) — (228 ) (28 ) (602 ) (1,607 ) (3,472 ) Recoveries 859 564 — 195 299 141 1,080 3,138 Provision (benefit) 2,853 2,892 (844 ) 271 (240 ) 810 333 6,075 Ending balance $ 16,921 $ 30,369 $ 4,522 $ 1,502 $ 2,621 $ 5,238 $ 393 $ 61,566 Ending balance: collectively evaluated for impairment $ 13,260 $ 30,173 $ 4,522 $ 1,494 $ 1,535 $ 4,996 $ 372 $ 56,352 Ending balance: individually evaluated for impairment $ 3,661 $ 196 $ — $ 8 $ 1,086 $ 242 $ 21 $ 5,214 Financing receivables ending balance: Collectively evaluated for impairment $ 862,875 $ 2,983,642 $ 320,391 $ 121,855 $ 622,392 $ 982,095 $ 10,666 $ 5,903,916 Individually evaluated for impairment 39,178 16,813 — 871 14,175 5,863 397 77,297 Purchased credit impaired loans — 10,343 — — 7,859 189 1 18,392 Total loans by group $ 902,053 $ 3,010,798 $ 320,391 $ 122,726 $ 644,426 $ 988,147 $ 11,064 $ 5,999,605 (1) December 31, 2015 Commercial Commercial Commercial Small Residential Other Consumer Total (Dollars in thousands) Allowance for loan losses Beginning balance $ 15,573 $ 25,873 $ 3,945 $ 1,171 $ 2,834 $ 4,956 $ 748 $ 55,100 Charge-offs (2,010 ) (330 ) — (267 ) (285 ) (710 ) (1,316 ) (4,918 ) Recoveries 1,593 1,073 — 264 133 356 724 4,143 Provision (benefit) (1,354 ) 711 1,421 96 (92 ) 287 431 1,500 Ending balance $ 13,802 $ 27,327 $ 5,366 $ 1,264 $ 2,590 $ 4,889 $ 587 $ 55,825 Ending balance: collectively evaluated for impairment $ 13,619 $ 27,123 $ 5,366 $ 1,260 $ 1,312 $ 4,651 $ 564 $ 53,895 Ending balance: individually evaluated for impairment $ 183 $ 204 $ — $ 4 $ 1,278 $ 238 $ 23 $ 1,930 Financing receivables ending balance: Collectively evaluated for impairment $ 838,129 $ 2,619,294 $ 373,064 $ 95,225 $ 614,014 $ 921,563 $ 14,427 $ 5,475,716 Individually evaluated for impairment 5,147 22,986 304 1,021 15,405 5,989 558 51,410 Purchase credit impaired loans — 11,154 — — 9,187 251 3 20,595 Total loans by group $ 843,276 $ 2,653,434 $ 373,368 $ 96,246 $ 638,606 $ 927,803 $ 14,988 $ 5,547,721 (1) (1) The amount of net deferred costs on originated loans included in the ending balance was $6.1 million , $5.1 million , and $4.3 million at December 31, 2017 , 2016 , and 2015 , respectively. Net unamortized discounts on acquired loans not deemed to be PCI included in the ending balance was $9.4 million , $8.6 million , and $6.6 million at December 31, 2017 , 2016 , and 2015 , respectively.
Schedule of Internal Risk-Rating Categories for the Company's Commercial Portfolio	The following table details the amount of outstanding principal balances relative to each of the risk-rating categories for the Company’s commercial portfolio: December 31, 2017 Category Risk Commercial and Commercial Real Commercial Small Business Total (Dollars in thousands) Pass 1 - 6 $ 806,331 $ 3,007,672 $ 400,964 $ 130,265 $ 4,345,232 Potential weakness 7 16,563 69,788 — 1,471 87,822 Definite weakness - loss unlikely 8 59,415 38,637 833 631 99,516 Partial loss probable 9 6,219 464 — 3 6,686 Definite loss 10 — — — — — Total $ 888,528 $ 3,116,561 $ 401,797 $ 132,370 $ 4,539,256 December 31, 2016 Category Risk Commercial and Commercial Real Commercial Small Business Total (Dollars in thousands) Pass 1 - 6 $ 783,825 $ 2,876,570 $ 317,099 $ 120,304 $ 4,097,798 Potential weakness 7 46,176 84,641 1,363 1,859 134,039 Definite weakness - loss unlikely 8 71,991 47,164 1,929 556 121,640 Partial loss probable 9 61 2,423 — 7 2,491 Definite loss 10 — — — — — Total $ 902,053 $ 3,010,798 $ 320,391 $ 122,726 $ 4,355,968
Schedule of Weighted Average FICO Scores and Weighted Average Combined LTV Ratio	December 31 2017 2016 Residential portfolio FICO score (re-scored)(1) 745 743 LTV (re-valued)(2) 59.2 % 63.2 % Home equity portfolio FICO score (re-scored)(1) 766 767 LTV (re-valued)(2)(3) 50.1 % 55.9 % (1) The average FICO scores at December 31, 2017 are based upon rescores available from August 2017 and origination score data for loans booked between September and December 2017. The average FICO scores at December 31, 2016 are based upon rescores available from November 2016 and origination score data for loans booked in December 2016. (2) The combined LTV ratios for December 31, 2017 are based upon updated automated valuations as of August 2017, when available, and/or the most current valuation data available as of December 31, 2017. The combined LTV ratios for December 31, 2016 are based upon updated automated valuations as of March 2015, when available, and /or the most current valuation data for loans as of December 31, 2016. The updated automated valuations provides new information on loans that may be available since the previous valuation was obtained. If no new information is available, the valuation will default to the previously obtained data or most recent appraisal. (3) For home equity loans and lines in a subordinate lien, the LTV data represents a combined LTV, taking into account the senior lien data for loans and lines.
Schedule of Nonaccrual Loans	The following table shows the carrying value of nonaccrual loans at the dates indicated: December 31 2017 2016 (Dollars in thousands) Commercial and industrial $ 32,055 $ 37,455 Commercial real estate 3,123 6,266 Small business 230 302 Residential real estate 8,129 7,782 Home equity 6,022 5,553 Other consumer 71 47 Total nonaccrual loans (1) $ 49,630 $ 57,405 (1) Included in these amounts were $6.1 million and $5.2 million of nonaccruing TDRs at December 31, 2017 and 2016 , respectively
Foreclosed Residential Real Estate Property [Table Text Block]	The following table shows information regarding foreclosed residential real estate property at the date indicated: December 31, 2017 December 31, 2016 (Dollars in thousands) Foreclosed residential real estate property held by the creditor $ 612 $ 3,775 Recorded investment in mortgage loans collateralized by residential real estate property that are in the process of foreclosure $ 2,971 $ 1,715
Schedule of the Age Analysis of Past Due Financing Receivables	The following table shows the age analysis of past due financing receivables as of the dates indicated: December 31, 2017 30-59 days 60-89 days 90 days or more Total Past Due Current Total Recorded Number Principal Number Principal Number Principal Number Principal (Dollars in thousands) Commercial and industrial 2 $ 195 2 $ 370 14 $ 32,007 18 $ 32,572 $ 855,956 $ 888,528 $ — Commercial real estate 7 3,060 — — 9 1,793 16 4,853 3,111,708 3,116,561 — Commercial construction — — — — — — — — 401,797 401,797 — Small business 17 339 11 144 10 57 38 540 131,830 132,370 — Residential real estate 6 870 13 2,385 22 3,471 41 6,726 747,603 754,329 — Home equity 22 1,310 6 451 20 2,025 48 3,786 1,048,302 1,052,088 — Other consumer (1) 265 197 16 27 17 45 298 269 9,611 9,880 8 Total 319 $ 5,971 48 $ 3,377 92 $ 39,398 459 $ 48,746 $ 6,306,807 $ 6,355,553 $ 8 December 31, 2016 30-59 days 60-89 days 90 days or more Total Past Due Current Total Recorded Number Principal Number Principal Number Principal Number Principal (Dollars in thousands) Commercial and industrial 8 $ 100 32 $ 253 6 $ 2,480 46 $ 2,833 $ 899,220 $ 902,053 $ — Commercial real estate 5 1,518 8 1,957 8 3,105 21 6,580 3,004,218 3,010,798 — Commercial construction — — — — — — — — 320,391 320,391 — Small business 9 323 — — 19 140 28 463 122,263 122,726 — Residential real estate 11 1,277 9 1,950 27 3,507 47 6,734 637,692 644,426 — Home equity 19 1,117 11 767 16 1,209 46 3,093 985,054 988,147 — Other consumer (1) 249 184 12 17 15 7 276 208 10,856 11,064 2 Total 301 $ 4,519 72 $ 4,944 91 $ 10,448 464 $ 19,911 $ 5,979,694 $ 5,999,605 $ 2 (1) Other consumer portfolio is inclusive of deposit account overdrafts recorded as loan balances
Schedule of Troubled Debt Restructuring and Other Pertinent Information	The following table shows the Company’s total TDRs and other pertinent information as of the dates indicated: December 31 2017 2016 (Dollars in thousands) TDRs on accrual status $ 25,852 $ 27,093 TDRs on nonaccrual status 6,067 5,199 Total TDRs $ 31,919 $ 32,292 Amount of specific reserves included in the allowance for loan loss associated with TDRs: $ 1,342 $ 1,417 Additional commitments to lend to a borrower who has been a party to a TDR: $ 487 $ 1,378
Schedule of Troubled Debt Restructuring Modifications	The following table shows the modifications which occurred during the periods indicated and the change in the recorded investment subsequent to the modifications occurring: Years Ended December 31 2017 Number Pre-Modification Post-Modification (Dollars in thousands) Troubled debt restructurings Commercial and industrial 12 $ 1,787 $ 1,787 Commercial real estate 6 2,705 2,705 Small business 9 369 369 Residential real estate 10 1,284 1,326 Home equity 17 1,985 1,988 Total 54 $ 8,130 $ 8,175 2016 Troubled debt restructurings Commercial and industrial 10 $ 1,623 $ 1,623 Commercial real estate 10 2,959 2,959 Small business 3 188 188 Residential real estate 8 1,808 1,850 Home equity 13 932 932 Other consumer 6 153 153 Total 50 $ 7,663 $ 7,705 2015 Troubled debt restructurings Commercial and industrial 13 $ 1,314 $ 1,314 Commercial real estate 6 2,941 2,941 Small business 9 293 293 Residential real estate 8 843 870 Home equity 8 694 694 Total 44 $ 6,085 $ 6,112 (1) The post-modification balances represent the legal principal balance of the loan on the date of modification. These amounts may show an increase when modifications include a capitalization of interest
Schedule of Post-Modification Balance of Troubled Debt Restructuring by Type of Modification	The following table shows the Company’s post-modification balance of TDRs listed by type of modification as of the periods indicated: Years Ended December 31 2017 2016 2015 (Dollars in thousands) Extended maturity $ 5,881 $ 5,044 $ 2,936 Adjusted interest rate — 92 — Combination rate and maturity 568 1,035 2,199 Court ordered concession 1,726 1,534 977 Total $ 8,175 $ 7,705 $ 6,112
Schedule of Troubled Debt Restructurings Which Have Subsequently Defaulted	The Company considers a loan to have defaulted when it reaches 90 days past due. The following table shows loans that were modified during the prior twelve months and subsequently defaulted during the periods indicated: Years Ended December 31 2017 2016 2015 Number Recorded Number Recorded Number Recorded (Dollars in thousands) Troubled debt restructurings that subsequently defaulted Commercial & industrial 1 $ 122 — $ — 3 $ 339 Commercial real estate — — 1 249 1 502 Residential real estate — — — — 2 326 Home equity — — — — 1 100 Total 1 $ 122 1 $ 249 7 $ 1,267
Schedule of Impaired Loans by Loan Portfolio	The table below sets forth information regarding the Company’s impaired loans. The information for average recorded investment and interest income recognized is reflective of the full period being presented and does not take into account the date at which a loan was deemed to be impaired. See information below as of the dates indicated: As of and For the Years Ended December 31 2017 Recorded Unpaid Related Average Interest Income Recognized (Dollars in thousands) With no related allowance recorded Commercial and industrial $ 34,267 $ 38,329 $ — $ 36,631 $ 446 Commercial real estate 13,245 14,374 — 13,683 559 Small business 556 619 — 569 21 Residential real estate 4,264 4,397 — 4,332 218 Home equity 4,950 5,056 — 5,063 198 Other consumer 91 92 — 102 7 Subtotal 57,373 62,867 — 60,380 1,449 With an allowance recorded Commercial and industrial 376 376 10 391 19 Commercial real estate 3,393 3,399 42 3,447 198 Small business 147 153 1 238 14 Residential real estate 9,420 10,154 1,007 9,575 284 Home equity 1,876 2,110 265 1,916 55 Other consumer 216 217 17 233 7 Subtotal 15,428 16,409 1,342 15,800 577 Total $ 72,801 $ 79,276 $ 1,342 $ 76,180 $ 2,026 2016 Recorded Unpaid Related Average Interest (Dollars in thousands) With no related allowance recorded Commercial and industrial $ 28,776 $ 29,772 $ — $ 26,472 $ 927 Commercial real estate 11,628 12,891 — 12,744 437 Small business 494 569 — 534 20 Residential real estate 4,216 4,427 — 4,302 185 Home equity 4,485 4,572 — 4,602 184 Other consumer 146 146 — 160 11 Subtotal 49,745 52,377 — 48,814 1,764 With an allowance recorded Commercial and industrial 10,402 10,440 3,661 10,760 325 Commercial real estate 5,185 5,533 196 5,491 200 Small business 377 392 8 408 21 Residential real estate 9,959 10,530 1,086 10,065 332 Home equity 1,378 1,547 242 1,403 50 Other consumer 251 252 21 268 8 Subtotal 27,552 28,694 5,214 28,395 936 Total $ 77,297 $ 81,071 $ 5,214 $ 77,209 $ 2,700 2015 Recorded Unpaid Related Average Interest (Dollars in thousands) With no related allowance recorded Commercial and industrial $ 2,613 $ 3,002 $ — $ 3,024 $ 71 Commercial real estate 12,008 13,128 — 11,676 375 Commercial construction 304 305 — 308 — Small business 527 618 — 584 22 Residential real estate 3,874 4,033 — 3,958 157 Home equity 4,893 5,005 — 5,023 195 Other consumer 184 185 — 201 15 Subtotal 24,403 26,276 — 24,774 835 With an allowance recorded Commercial and industrial 2,534 2,648 183 2,848 48 Commercial real estate 10,978 11,047 204 10,789 592 Small business 494 523 4 535 30 Residential real estate 11,531 12,652 1,278 11,669 460 Home equity 1,096 1,287 238 655 14 Other consumer 374 389 23 408 14 Subtotal 27,007 28,546 1,930 26,904 1,158 Total $ 51,410 $ 54,822 $ 1,930 $ 51,678 $ 1,993
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Table Text Block]	The following table displays certain information pertaining to PCI loans at the dates indicated: December 31 2017 2016 (Dollars in thousands) Outstanding balance $ 14,485 $ 20,477 Carrying amount $ 13,023 $ 18,392
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Table Text Block]	The following table summarizes activity in the accretable yield for the PCI loan portfolio: 2017 2016 (Dollars in thousands) Beginning balance $ 2,370 $ 2,827 Accretion (1,475 ) (1,540 ) Other change in expected cash flows (1) 748 953 Reclassification from nonaccretable difference for loans which have paid off (2) 148 130 Ending balance $ 1,791 $ 2,370 (1) Represents changes in cash flows expected to be collected resulting in increased interest income as a prospective yield adjustment over the remaining life of the loan(s). (2) Results in increased income during the period when a loan pays off at amount greater than originally expected

BANK PREMISES AND EQUIPMENT (Ta

BANK PREMISES AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Schedule of Premises and Equipment	BANK PREMISES AND EQUIPMENT Bank premises and equipment at December 31, were as follows: 2017 2016 Estimated (Dollars in thousands) (In years) Cost Land $ 23,719 $ 20,585 n/a Bank premises 49,159 43,553 5-40 Leasehold improvements 25,184 24,387 1-27 Furniture and equipment 62,521 58,237 1-12 Leased equipment 10,644 — 7 Total cost 171,227 146,762 Accumulated depreciation (76,505 ) (68,282 ) Net bank premises and equipment $ 94,722 $ 78,480

GOODWILL AND IDENTIFIABLE INT36

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets and Goodwill	The following table sets forth the carrying value of goodwill and other intangible assets, net of accumulated amortization, at December 31: 2017 2016 (Dollars in thousands) Balances not subject to amortization Goodwill $ 231,806 $ 221,526 Balances subject to amortization Core deposit intangibles 8,636 8,527 Other intangible assets 705 1,321 Total other intangible assets 9,341 9,848 Total goodwill and other intangible assets $ 241,147 $ 231,374
Schedule of Goodwill	The changes in the carrying value of goodwill for the periods indicated were as follows: 2017 2016 (Dollars in thousands) Balance at beginning of year $ 221,526 $ 201,083 Acquisitions 10,280 20,443 Balance at end of year $ 231,806 $ 221,526
Schedule of Other Intangible Assets	The gross carrying amount and accumulated amortization of other intangible assets were as follows at the dates indicated: December 31 2017 2016 Gross Accumulated Net Gross Accumulated Net (Dollars in thousands) Core deposit intangibles $ 26,736 $ (18,100 ) $ 8,636 $ 23,917 $ (15,390 ) $ 8,527 Other intangible assets 3,165 (2,460 ) 705 3,020 (1,699 ) 1,321 Total $ 29,901 $ (20,560 ) $ 9,341 $ 26,937 $ (17,089 ) $ 9,848
Schedule of Intangible Assets Estimated Annual Amortization Expense	The following table sets forth the estimated annual amortization expense of intangible assets for each of the next five years: Year Amount (Dollars in thousands) 2018 $ 2,394 2019 $ 1,687 2020 $ 1,414 2021 $ 1,245 2022 $ 948

DEPOSITS (Tables)

DEPOSITS (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Schedule of Time Deposits Maturities	The following is a summary of the scheduled maturities of time deposits as of December 31: 2017 2016 (Dollars in thousands) 1 year or less $ 393,452 61.1 % $ 430,834 66.4 % Over 1 year to 2 years 119,341 18.5 % 82,627 12.7 % Over 2 years to 3 years 57,619 8.9 % 44,190 6.8 % Over 3 years to 4 years 41,183 6.4 % 49,446 7.6 % Over 4 years to 5 years 32,706 5.1 % 42,055 6.5 % Total $ 644,301 100.0 % $ 649,152 100.0 %

BORROWINGS (Tables)

BORROWINGS (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Federal Home Loan Bank Borrowings	Advances payable to the Federal Home Loan Bank as of December 31 are summarized as follows: 2017 2016 Weighted Weighted Average Average Total Contractual Total Contractual Outstanding Rate Outstanding Rate (Dollars in thousands) Stated Maturity 2017 $ — — % $ 50,000 2.43 % 2018 52,475 1.58 % — — % Subtotal 52,475 1.58 % 50,000 2.43 % Amortizing advances 789 819 Total Federal Home Loan Bank Advances $ 53,264 $ 50,819
Schedule of Underlying Assets of Repurchase Agreements when Amount of Repurchase Agreements Exceeds 10 Percent of Assets [Table Text Block]	The table below sets forth the remaining contractual maturity of the Company’s repurchase agreements allocated by source of collateral at the dates indicated: December 31 2017 2016 (Dollars in thousands) Sources of Collateral U.S. government agency securities $ 16,867 $ 20,233 Agency mortgage-backed securities 51,273 79,079 Agency collateralized mortgage obligations 94,539 77,601 Total customer repurchase agreements (1) $ 162,679 $ 176,913
Schedule of Long-term Borrowings	The following table summarizes long-term debt, net of debt issuances costs, as of the periods indicated: December 31 2017 2016 (Dollars in thousands) Junior subordinated debentures Capital Trust V $ 51,503 $ 51,500 Slades Ferry Trust I 10,229 10,224 Central Trust I 5,258 5,302 Central Trust II 6,083 6,081 Subordinated debentures 34,682 34,635 Total long-term debt $ 107,755 $ 107,742
Information relating to Trust Preferred Securities [Table Text Block]	Information relating to these trust preferred securities are as follows: Trust Description of Capital Securities Capital Trust V $50.0 million due in 2037, interest at a variable rate of 3 month LIBOR plus 1.48% (3.07% at December 31, 2017),which, effective on January 17, 2017, has been converted to a fixed rate of 2.84% through the use of an interest rate swap. Prior to 2017, this borrowing had been converted to a fixed rate of 6.52%, through the use of an interest rate swap which expired on December 28, 2016. These securities are callable quarterly, until maturity. Slades Ferry Trust I $10.0 million due in 2034, bearing interest at a variable rate of 3 month LIBOR plus 2.79% (4.39% at December 31, 2017). These securities are callable quarterly, until maturity. Central Trust I $5.1 million due in 2034, bearing interest at a variable rate of 3 month LIBOR plus 2.44% (4.03% at December 31, 2017). These securities are callable quarterly, until maturity. Central Trust II $5.9 million due in 2037, bearing interest at a variable rate of 3 month LIBOR plus 1.65% (3.24% at December 31, 2017), beginning in March of 2017. Previously, the interest was at a fixed rate of 7.015%. These securities are callable quarterly, until maturity.
Schedule of Maturities of Borrowings	The following table sets forth the contractual maturities of long-term debt over the next five years: 2018 2019 2020 2021 2022 Thereafter Total (Dollars in thousands) Junior subordinated debentures Capital trust V $ — $ — $ — $ — $ — $ 51,547 $ 51,547 Slades ferry trust I — — — — — 10,310 10,310 Central trust I — — — — — 5,258 5,258 Central trust II — — — — — 6,083 6,083 Subordinated debentures — — — — — 35,000 35,000 Total $ — $ — $ — $ — $ — $ 108,198 $ 108,198

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of the Components of Earnings Per Share	Earnings per share consisted of the following components for the years ended December 31: 2017 2016 2015 (Dollars in thousands, except per share data) Net income $ 87,204 $ 76,648 $ 64,960 Weighted Average Shares Basic shares 27,294,028 26,404,071 25,891,382 Effect of dilutive securities 78,076 51,847 68,566 Diluted shares 27,372,104 26,455,918 25,959,948 Net income per share Basic EPS $ 3.19 $ 2.90 $ 2.51 Effect of dilutive securities — — (0.01 ) Diluted EPS $ 3.19 $ 2.90 $ 2.50

STOCK BASED COMPENSATION (Table

STOCK BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Cumulatively Granted Stock Options and Restricted Stock Awards, Net of Forfeitures	The following table presents the amount of cumulatively granted stock options and restricted stock awards, net of forfeitures, through December 31, 2017 : Authorized Awards Cumulative Granted, Net of Total Authorized Stock Restricted 2005 Plan 1,650,000 537,941 695,546 1,233,487 416,513 2010 Plan 314,600 42,000 93,245 135,245 179,355
Schedule of Pre-tax Compensation Expense and Related Tax Benefits	The following table presents the pre-tax expense associated with stock option and restricted stock awards and the related tax benefits recognized for the years presented: Years Ended December 31 2017 2016 2015 (Dollars in thousands) Stock based compensation expense Restricted stock awards(1) $ 2,730 $ 2,590 $ 2,296 Directors’ fee expense Stock options 76 72 — Restricted stock awards 527 303 194 Total stock based award expense $ 3,333 $ 2,965 $ 2,490 Related tax benefits recognized in earnings $ 1,362 $ 1,211 $ 1,122 (1) Inclusive of compensation expense associated with time-vested and performance-based restricted stock awards.
Schedule of Stock Options Granted	The Company made the following awards of nonqualified options to purchase shares of common stock in 2017 and 2016 . There were no such awards made in 2015 . Years Ended December 31 2017 2016 Date of grant 11/7/2017 7/14/2016 2/20/2016 Plan 2010 2010 2010 Options granted 5,000 5,000 5,000 Vesting period (beginning on the grant date) 14 months 18 months 22 months Expiration date 11/7/2027 7/14/2026 2/20/2026 Expected volatility 20.80 % 32.28 % 32.44 % Expected life (years) 5.5 5.5 5.5 Expected dividend yield 1.87 % 2.37 % 2.28 % Risk free interest rate 2.02 % 1.14 % 1.29 % Fair value per option $ 12.43 $ 11.46 $ 10.59
Schedule of Relevant Information Relating to Stock Options	The following table presents relevant information relating to the Company’s stock options for the periods indicated: Years Ended December 31 2017 2016 2015 (Dollars in thousands, except per share data) Fair value of stock options vested based on grant date fair value $ 72 $ 37 $ 14 Intrinsic value of stock options exercised $ 1,082 $ 494 $ 3,362 Cash received from stock option exercises $ 918 $ 680 $ 6,105 Tax benefit realized on stock option exercises/repurchase $ 442 $ 204 $ 1,362 Weighted average grant date fair value of options granted (per share) $ 12.43 $ 11.03 $ —
Schedule of Stock Options	A summary of stock option activity of the Company’s Stock Option Grants for the year ended December 31, 2017 is presented in the table below: Outstanding Nonvested Stock Option Weighted Weighted Aggregate Stock Weighted (Dollars in thousands, except per share data) Balance at January 1, 2017 109,650 $ 29.93 6,666 $ 11.03 Granted 5,000 70.28 5,000 12.43 Exercised (30,150 ) 30.43 — — Vested n/a n/a (6,667 ) 10.85 Forfeited — — — — Expired (500 ) 28.88 — — Balance at December 31, 2017 84,000 (2) $ 32.16 3.04 years $ 3,258 4,999 $ 12.11 Options outstanding and expected to vest at December 31, 2017 84,000 (3) $ 32.16 3.04 years $ 3,258 Options exercisable at December 31, 2017 79,001 (4) $ 30.21 2.64 years $ 3,218 Unrecognized compensation cost $ 22 Weighted average remaining recognition period (years) 1.00 (1) The aggregate intrinsic value in the preceding tables represents the total pre-tax intrinsic value, based on the average of the high price and low price at which the Company’s common stock traded on December 31, 2017 of $70.95 , which would have been received by the option holders had they all exercised their options as of that date. (2) Inclusive of 38,000 stock options outstanding to Directors. (3) Inclusive of 38,000 vested stock options and expected to vest to Directors. (4) Inclusive of 33,001 vested stock options outstanding to Directors.
Schedule of Restricted Stock Granted	The Company grants both time-vested restricted stock awards as well as performance-based restricted stock awards. During the years ended December 31, 2017 , 2016 , and 2015 the Company has made the following restricted stock award grants: Shares Granted Plan Fair Value (1) Vesting Period Time-vested 2017 2/13/2017 1,200 1,200 2005 $ 62.53 Ratably over 5 years from grant date 2/16/2017 34,150 34,150 2005 $ 63.10 Ratably over 5 years from grant date 3/31/2017 500 500 2005 $ 65.63 Ratably over 5 years from grant date 4/3/2017 1,500 1,500 2005 $ 64.14 Once on November 30, 2017 (2) 5/15/2017 1,000 1,000 2005 $ 64.03 Ratably over 5 years from grant date 5/23/2017 7,000 7,000 2010 $ 61.95 At the end of 5 years from grant date (3) 6/15/2017 950 950 2005 $ 66.18 Ratably over 5 years from grant date 2016 2/11/2016 51,475 2005 $ 41.96 Ratably over 5 years from grant date 3/1/2016 600 2005 $ 44.37 Ratably over 5 years from grant date 5/24/2016 8,700 2010 $ 48.34 At the end of 5 years from grant date (3) 9/19/2016 800 2005 $ 52.92 Ratably over 5 years from grant date 11/7/2016 500 2005 $ 54.28 Ratably over 5 years from grant date 11/14/2016 725 2010 $ 63.43 Once on May 24, 2021 (4) 2015 2/11/2015 31,500 2005 $ 39.42 Ratably over 5 years from grant date 2/12/2015 25,910 2005 $ 40.03 Ratably over 5 years from grant date 3/19/2015 3,800 2005 $ 43.56 Ratably over 5 years from grant date 4/27/2015 625 2005 $ 41.61 At the end of 3 years from grant date 4/27/2015 1,875 2005 $ 41.61 At the end of 5 years from grant date 5/27/2015 8,800 2010 $ 45.02 At the end of 5 years from grant date (3) 7/14/2015 800 2010 $ 47.82 Once on May 27, 2020 (5) 10/13/2015 1,000 2005 $ 46.09 Ratably over 5 years from grant date 10/20/2015 2,000 2005 $ 46.47 Ratably over 5 years from grant date Performance-based 2/16/2017 14,400 2005 $ 63.10 The earlier of: the date on which it is determined if the performance goal has been achieved; or, March 31, 2020. 2/11/2016 20,450 2005 $ 41.96 The earlier of: the date on which it is determined if the performance goal has been achieved; or, March 31, 2019. 2/12/2015 21,780 2005 $ 40.03 The earlier of: the date on which it is determined if the performance goal has been achieved; or, March 31, 2018. (1) The fair value of the restricted stock awards are based upon the average of the high and low prices at which the Company’s common stock traded on the date of grant. The holders of time-vested restricted stock awards participate fully in the rewards of stock ownership of the Company, including voting and dividend rights. The holders of performance-based restricted stock awards do not participate in the rewards of stock ownership of the Company until vested. The holders of all restricted stock awards are not required to pay any consideration to the Company for the awards. (2) This restricted stock grant fully vested upon an employee's termination, on November 30, 2017. (3) These restricted stock grants will vest at the end of a five year period, or earlier if the director ceases to be a director for any reason other than cause, such as, for example, by retirement. (4) These restricted stock grants will vest on May 24, 2021, or earlier if the director ceases to be a director for any reason other than cause, such as, for example, by retirement. (5) These restricted stock grants will vest on May 27, 2020, or earlier if the director ceases to be a director for any reason other than cause, such as, for example, by retirement.
Schedule of Share-based Compensation, Fair Value of Restricted Stock Awards Vesting [Table Text Block]	The following table presents the fair value of restricted stock awards vesting during the periods presented: Years Ended December 31 2017 2016 2015 (Dollars in thousands) Fair value of restricted stock awards upon vesting $ 5,717 $ 3,019 $ 2,610	[1]
Schedule of Restricted Stock Awards	A summary of the status of the Company’s Restricted Stock Award Grants for the year ended December 31, 2017 is presented in the table below: Outstanding Restricted Stock Weighted Average (Dollars in thousands, except per share data) Balance at January 1, 2017 264,315 $ 38.88 Granted 60,700 63.07 Vested/released (89,436 ) 36.79 Forfeited (9,614 ) 39.49 Balance at December 31, 2017 225,965 (1) $ 46.18 Unrecognized compensation cost (inclusive of directors’ fees) $ 6,355 Weighted average remaining recognition period (years) 3.00 (1) Inclusive of 38,445 restricted stock awards outstanding to Directors.
[1]	These restricted stock grants will vest on May 27, 2020, or earlier if the director ceases to be a director for any reason other than cause, such as, for example, by retirement.

DERIVATIVES AND HEDGING ACTIV41

DERIVATIVES AND HEDGING ACTIVITIES (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes	The following table reflects the Company’s derivative positions for the periods indicated below for interest rate swaps which qualify as cash flow hedges for accounting purposes: December 31, 2017 Notional Trade Effective Maturity Receive Current Pay Fixed Fair Value (Dollars in thousands) $ 25,000 9-Dec-08 10-Dec-08 10-Dec-18 3 Month LIBOR 1.54 % 2.94 % $ (264 ) 25,000 1-Apr-16 17-Jan-17 15-Dec-21 3 Month LIBOR 1.59 % 1.36 % 772 25,000 1-Apr-16 17-Jan-17 15-Dec-21 3 Month LIBOR 1.59 % 1.36 % 763 25,000 18-Jul-17 15-Aug-17 15-Aug-22 3 Month LIBOR 1.42 % 1.88 % 345 $ 100,000 $ 1,616 December 31, 2016 Notional Trade Effective Maturity Receive Current Pay Fixed Fair Value (Dollars in thousands) $ 25,000 9-Dec-08 10-Dec-08 10-Dec-18 3 Month LIBOR 0.95 % 2.94 % $ (740 ) 25,000 1-Apr-16 17-Jan-17 15-Dec-21 3 Month LIBOR N/A 1.36 % 689 25,000 1-Apr-16 17-Jan-17 15-Dec-21 3 Month LIBOR N/A 1.36 % 675 $ 75,000 $ 624
Summary of customer related derivative positions, not designated as hedging	The following table reflects the Company’s customer related derivative positions for the periods indicated below for those derivatives not designated as hedging: Number of Notional Amount Maturing Less than 1 year Less than 2 years Less than 3 years Less than 4 years Thereafter Total Fair Value December 31, 2017 (Dollars in thousands) Loan level swaps Receive fixed, pay variable 246 $ 36,023 $ 61,500 $ 152,287 $ 111,147 $ 591,385 $ 952,342 $ 3,875 Pay fixed, receive variable 231 $ 36,023 $ 61,500 $ 152,287 $ 111,147 $ 591,385 $ 952,342 $ (3,880 ) Foreign exchange contracts Buys foreign currency, sells U.S. currency 15 $ 26,382 $ 3,780 $ — $ — $ — $ 30,162 $ 1,202 Buys U.S. currency, sells foreign currency 15 $ 26,382 $ 3,780 $ — $ — $ — $ 30,162 $ (1,188 ) December 31, 2016 (Dollars in thousands) Loan level swaps Receive fixed, pay variable 222 $ 30,245 $ 21,708 $ 63,771 $ 165,783 $ 567,897 $ 849,404 $ 12,005 Pay fixed, receive variable 207 $ 30,245 $ 21,708 $ 63,771 $ 165,783 567,897 $ 849,404 $ (12,008 ) Foreign exchange contracts Buys foreign currency, sells U.S. currency 33 $ 45,711 $ — $ — $ — $ — $ 45,711 $ (2,250 ) Buys U.S. currency, sells foreign currency 33 $ 45,711 $ — $ — $ — $ — $ 45,711 $ 2,277 (1) The Company may enter into one dealer swap agreement which offsets multiple commercial borrower swap agreements.
Fair value of derivative financial instruments as well as their classification on the balance sheet	The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the balance sheet at the periods indicated: Asset Derivatives Liability Derivatives Fair Value at Fair Value at Fair Value at Fair Value at Balance Sheet December 31, 2017 December 31, 2016 Balance Sheet December 31, 2017 December 31, 2016 (Dollars in thousands) Derivatives designated as hedges Interest rate derivatives Other assets $ 1,880 $ 1,364 Other liabilities $ 264 $ 740 Derivatives not designated as hedges Customer Related Positions: Loan level derivatives Other assets 14,236 18,629 Other liabilities 14,241 18,632 Foreign exchange contracts Other assets 1,202 2,338 Other liabilities 1,188 2,311 Mortgage Derivatives Interest rate lock commitments Other assets 149 430 Other liabilities — — Forward sales agreements Other assets 9 — Other liabilities — 233 15,596 21,397 15,429 21,176 Total $ 17,476 $ 22,761 $ 15,693 $ 21,916
Effect of derivative financial instruments included in OCI and current earnings	The table below presents the effect of the Company’s derivative financial instruments included in OCI and current earnings for the periods indicated: Years Ended December 31 2017 2016 2015 (Dollars in thousands) Derivatives designated as hedges Gain in OCI on derivatives (effective portion), net of tax $ 443 $ 2,170 $ 1,199 Loss reclassified from OCI into interest expense (effective portion) $ (441 ) $ (2,520 ) $ (2,828 ) Loss recognized in income on derivatives (ineffective portion and amount excluded from effectiveness testing) Interest expense $ — $ — $ — Other expense — — — Total $ — $ — $ — Derivatives not designated as hedges Changes in fair value of customer related positions Other income $ 6 $ 73 $ 60 Other expenses (21 ) (82 ) (53 ) Changes in fair value of mortgage derivatives Mortgage banking income (39 ) (35 ) (50 ) Total $ (54 ) $ (44 ) $ (43 )

BALANCE SHEET OFFSETTING (Table

BALANCE SHEET OFFSETTING (Tables)	12 Months Ended
	Dec. 31, 2017
Offsetting [Abstract]
Financial Instruments Derivative Assets Liabilities and resell agreements net of amount not offset [Table Text Block]	BALANCE SHEET OFFSETTING The Company does not offset fair value amounts recognized for derivative instruments or repurchase agreements. The Company does net the amount recognized for the right to reclaim cash collateral against the obligation to return cash collateral arising from derivative instruments executed with the same counterparty under a master netting arrangement. Collateral legally required to be maintained at dealer banks by the Company is monitored and adjusted as necessary. The following tables present the Company's asset and liability derivative positions and the potential effect of netting arrangements on its financial position, as of the periods indicated: Gross Amounts Not Offset in the Statement of Financial Position Gross Amounts Recognized in the Statement of Financial Position Gross Amounts Offset in the Statement of Financial Position Net Amounts Presented in the Statement of Financial Position Financial Instruments (1) Collateral Pledged (Received) Net Amount December 31, 2017 (Dollars in thousands) Derivative Assets Interest rate swaps $ 1,880 $ — $ 1,880 $ 805 $ — $ 1,075 Loan level derivatives 14,236 — 14,236 4,578 — 9,658 Customer foreign exchange contracts 1,202 — 1,202 — — 1,202 $ 17,318 $ — $ 17,318 $ 5,383 $ — $ 11,935 Derivative Liabilities Interest rate swaps $ 264 $ — $ 264 $ — $ 264 $ — Loan level derivatives 14,241 — 14,241 5,383 3,675 5,183 Customer foreign exchange contracts 1,188 — 1,188 — — 1,188 $ 15,693 $ — $ 15,693 $ 5,383 $ 3,939 $ 6,371 Customer repurchase agreements $ 162,679 $ — $ 162,679 $ — $ 162,679 $ — (1) Reflects offsetting derivative positions with the same counterparty. Gross Amounts Not Offset in the Statement of Financial Position Gross Amounts Recognized in the Statement of Financial Position Gross Amounts Offset in the Statement of Financial Position Net Amounts Presented in the Statement of Financial Position Financial Instruments (1) Collateral Pledged (Received) Net Amount December 31, 2016 (Dollars in thousands) Derivative Assets Interest rate swaps $ 1,364 $ — $ 1,364 $ 961 $ — $ 403 Loan level derivatives 18,629 — 18,629 3,261 — 15,368 Customer foreign exchange contracts 2,338 — 2,338 — — 2,338 $ 22,331 $ — $ 22,331 $ 4,222 $ — $ 18,109 Derivative Liabilities Interest rate swaps $ 740 $ — $ 740 $ — $ 740 $ — Loan level derivatives 18,632 — 18,632 4,222 11,106 3,304 Customer foreign exchange contracts 2,311 — 2,311 — — 2,311 $ 21,683 $ — $ 21,683 $ 4,222 $ 11,846 $ 5,615 Customer repurchase agreements $ 176,913 $ — $ 176,913 $ — $ 176,913 $ — (1) Reflects offsetting derivative positions with the same counterparty.

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Components of Income Taxes	The provision for income taxes is comprised of the following components: Years Ended December 31 2017 2016 2015 (Dollars in thousands) Current expense Federal $ 28,852 $ 26,549 $ 11,946 State 9,278 8,883 5,052 Total current expense 38,130 35,432 16,998 Deferred expense (benefit) Federal 7,953 153 8,466 State 1,258 (158 ) 1,754 Total deferred expense (benefit) 9,211 (5 ) 10,220 Total expense $ 47,341 $ 35,427 $ 27,218
Schedule of Income Tax Rate Reconciliation	The difference between the statutory federal income tax rate of 35% and the effective income tax rate reported for the last three years is detailed below: Years Ended December 31 2017 2016 2015 (Dollars in thousands) Computed statutory federal income tax provision $ 47,091 35.00 % $ 39,226 35.00 % $ 32,262 35.00 % State taxes, net of federal tax benefit 6,817 5.07 % 5,643 5.03 % 4,500 4.88 % Revaluation of net deferred tax assets 1,895 1.41 % — — % — — % Merger and other related costs (non-deductible) 213 0.16 % 210 0.19 % 185 0.20 % Change in valuation allowance 31 0.02 % 28 0.02 % 41 0.04 % New Markets Tax Credits (3,960 ) (2.94 )% (6,360 ) (5.67 )% (6,514 ) (7.07 )% Increase in cash surrender value of life insurance (1,445 ) (1.07 )% (1,431 ) (1.28 )% (1,292 ) (1.40 )% Stock-based compensation (1,258 ) (0.94 )% — — % — — % Low Income Housing Project Investments (1,253 ) (0.93 )% (1,641 ) (1.46 )% (1,182 ) (1.28 )% Nontaxable interest, net (987 ) (0.73 )% (996 ) (0.89 )% (973 ) (1.06 )% Other, net 197 0.15 % 748 0.67 % 191 0.22 % Total expense $ 47,341 35.20 % $ 35,427 31.61 % $ 27,218 29.53 %
Schedule of Net Deferred Tax Asset	The tax-effected components of the net deferred tax asset at December 31 were as follows: 2017 2016 (Dollars in thousands) Deferred tax assets Accrued expenses not deducted for tax purposes $ 9,268 $ 15,401 Allowance for loan losses 16,702 24,681 Deferred gain on sale leaseback transaction 909 1,744 Employee and director equity compensation 1,559 2,095 Federal Home Loan Bank borrowings fair value adjustment 26 82 Loan basis difference fair value adjustment 3,070 4,336 Net operating loss carry-forward 127 69 Net unrealized loss on securities available for sale 106 — Other 527 1,015 Gross deferred tax assets 32,294 49,423 Valuation allowance (121 ) (69 ) Total deferred tax assets net of valuation allowance $ 32,173 $ 49,354 Deferred tax liabilities Core deposit and other intangibles $ 2,057 $ 3,040 Deferred loan fees, net 4,275 5,407 Fixed assets 5,270 6,168 Goodwill 10,265 14,737 Net unrealized gain on securities available for sale — 105 Derivatives fair value adjustment 524 454 Other 4,307 3,909 Gross deferred tax liabilities $ 26,698 $ 33,820 Total net deferred tax asset $ 5,475 $ 15,534
Reconciliation of Unrecognized Tax Benefits	The Company accounts for uncertainties in income taxes by providing a tax reserve for certain positions. The following is a reconciliation of the beginning and ending amount of unrecognized tax benefits: (Dollars in thousands) Balance at December 31, 2015 $ 81 Reduction of tax positions for prior years — Increase for prior year tax position — Increase for current year tax positions 30 Balance at December 31, 2016 $ 111 Reduction of tax positions for prior years — Increase for prior year tax positions — Increase for current year tax positions 31 Balance at December 31, 2017 $ 142

LOW INCOME HOUSING PROJECT IN44

LOW INCOME HOUSING PROJECT INVESTMENTS Low Income Housing Project Investments (Tables)	12 Months Ended
	Dec. 31, 2017
Low Income Housing Project Investments [Abstract]
Investments in Low Income Housing Projects [Table Text Block]	The following table presents certain information related to the Company's investments in low income housing projects as of December 31: 2017 2016 2015 (Dollars in thousands) Original investment value $ 47,399 $ 47,379 $ 42,199 Current recorded investment $ 35,225 $ 39,606 $ 38,151 Unfunded liability obligation $ 4,536 $ 12,161 $ 14,607 Tax credits and benefits earned during the year $ 5,654 $ 5,366 $ 3,632 Amortization of investments during the year (1) $ 4,402 $ 3,725 $ 2,450 Net income tax benefit recognized during the year $ 1,253 $ 1,641 $ 1,182 (1) The 2017 amount is inclusive of $466,000 related to the revaluation of Low Income Housing tax credit investments as a result of the 2017 Tax Act.

EMPLOYEE BENEFIT PLANS (Tables)

EMPLOYEE BENEFIT PLANS (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Schedule of Multiemployer Plan	Funding Status FIP/RP Status Surcharge Expiration Minimum EIN/Pension 2017 2016 Pentegra defined benefit plan for financial institutions 13-5645888/333 At least 80 percent At least 80 percent No No N/A $ —
Schedule of Multiemployer Plan Contributions	The Company’s contributions to the Pension Plans were as follows for the periods indicated: Required Contributions - Plan Year Allocation Cash Payment Future period funding 2017-2018 2016-2017 2015-2016 (Dollars in thousands) 2017 $ 6,432 $ 5,000 $ 1,432 $ — $ — 2016 $ 6,245 $ 4,000 $ — $ 2,245 $ — 2015 $ 2,983 $ 1,215 $ — $ — $ 1,768
Schedule of Supplemental Retirement Expense and Contributions Paid	The following table shows the defined benefit supplemental retirement expense, and the contributions paid to the plans which were used only to pay the current year benefits as of the dates indicated: 2017 2016 2015 (Dollars in thousands) Retirement expense $ 1,580 $ 1,513 $ 1,834 Contributions paid $ 367 $ 320 $ 276
Schedule of Expected Benefit Payments	Expected future benefit payments for the defined benefit supplemental executive retirement plans are presented below: Defined Benefit Supplemental Executive (Dollars in thousands) 2018 $ 408 2019 $ 481 2020 $ 467 2021 $ 461 2022 $ 454 2023-2027 $ 5,366
Schedule of Supplemental Executive Retirement Plans	The following table illustrates the status of the defined benefit supplemental executive retirement plans at December 31 for the years presented: Defined Benefit Supplemental Executive 2017 2016 2015 (Dollars in thousands) Change in accumulated benefit obligation Benefit obligation at beginning of year $ 14,177 $ 13,290 $ 12,537 Accumulated service cost 423 395 742 Interest cost 547 539 470 Actuarial loss/(gain) 969 273 (183 ) Benefits paid (367 ) (320 ) (276 ) Accumulated benefit obligation at end of year $ 15,749 $ 14,177 $ 13,290 Change in plan assets Fair value of plan assets at beginning of year $ — $ — $ — Employer contribution 367 320 276 Benefits paid (367 ) (320 ) (276 ) Fair value of plan assets at end of year $ — $ — $ — Funded status at end of year $ (15,749 ) $ (14,177 ) $ (13,290 ) Assets — — — Liabilities (15,749 ) (14,177 ) (13,290 ) Accrued benefit cost $ (15,749 ) $ (14,177 ) $ (13,290 ) Amounts recognized in accumulated other comprehensive income (“AOCI”) Net loss $ 3,465 $ 2,830 $ 2,859 Prior service cost 1,047 1,323 1,599 Amounts recognized in AOCI $ 4,512 $ 4,153 $ 4,458 Information for plans with an accumulated benefit obligation in excess of plan assets Projected benefit obligation $ 15,749 $ 14,177 $ 13,290 Accumulated benefit obligation $ 15,749 $ 14,177 $ 13,290 Net periodic benefit cost Service cost $ 423 $ 395 $ 742 Interest cost 547 539 470 Amortization of prior service cost 276 276 305 Recognized net actuarial loss 334 303 317 Net periodic benefit cost $ 1,580 $ 1,513 $ 1,834 Amounts in accumulated other comprehensive income expected to be recognized in net periodic benefit cost over next fiscal year Net actuarial loss $ 415 $ 338 $ 270 Net prior service cost $ 276 $ 276 $ 276 Discount rate used for benefit obligation 2.48-3.45% 2.49-3.94% 2.49-4.16% Discount rate used for net periodic benefit cost 2.49-3.94% 2.49-4.16% 2.24-3.84% Rate of compensation increase n/a n/a n/a

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis	Assets and liabilities measured at fair value on a recurring and nonrecurring basis were as follows as of the dates indicated: Fair Value Measurements at Reporting Date Using Balance Quoted Prices in Significant Other Significant December 31, 2017 (Dollars in thousands) Recurring fair value measurements Assets Trading securities $ 1,324 $ 1,324 $ — $ — Securities available for sale U.S. Government agency securities 35,430 — 35,430 — Agency mortgage-backed securities 215,764 — 215,764 — Agency collateralized mortgage obligations 122,012 — 122,012 — State, county, and municipal securities 2,274 — 2,274 — Single issuer trust preferred securities issued by banks and insurers 2,016 — 2,016 — Pooled trust preferred securities issued by banks and insurers 1,640 — — 1,640 Small business administration pooled securities 47,778 — 47,778 — Equity securities 20,584 20,584 — — Loans held for sale 4,768 — 4,768 — Derivative instruments 17,476 — 17,476 — Liabilities Derivative instruments 15,693 — 15,693 — Total recurring fair value measurements $ 455,373 $ 21,908 $ 431,825 $ 1,640 Nonrecurring fair value measurements Assets Collateral dependent impaired loans $ 33,567 $ — $ — $ 33,567 Other real estate owned and other foreclosed assets 612 — — 612 Total nonrecurring fair value measurements $ 34,179 $ — $ — $ 34,179 Fair Value Measurements at Reporting Date Using Balance Quoted Prices in Significant Other Significant December 31, 2016 (Dollars in thousands) Recurring fair value measurements Assets Trading securities $ 804 $ 804 $ — $ — Securities available for sale U.S. Government agency securities 24,244 $ — 24,244 — Agency mortgage-backed securities 175,384 — 175,384 — Agency collateralized mortgage obligations 99,868 — 99,868 — State, county, and municipal securities 3,793 — 3,793 — Single issuer trust preferred securities issued by banks and insurers 2,311 — 2,311 — Pooled trust preferred securities issued by banks and insurers 1,584 — — 1,584 Small business administration pooled securities 37,189 — 37,189 — Equity securities 19,271 19,271 — — Loans held for sale 6,139 — 6,139 — Derivative instruments 22,761 — 22,761 — Liabilities Derivative instruments 21,916 — 21,916 — Total recurring fair value measurements $ 371,432 $ 20,075 $ 349,773 $ 1,584 Nonrecurring fair value measurements: Assets Collateral dependent impaired loans $ 33,974 $ — $ — $ 33,974 Other real estate owned and other foreclosed assets 4,173 — — 4,173 Total nonrecurring fair value measurements $ 38,147 $ — $ — $ 38,147
Reconciliation of Assets on Recurring Basis Using Significant Unobservable Inputs	All assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) were valued using pricing models and discounted cash flow methodologies, as of December 31, 2017 , 2016 and 2015 . This reconciliation is presented in the table below, for the periods indicated: 2017 2016 2015 (Dollars in thousands) Pooled Trust Preferred Securities Beginning balance $ 1,584 $ 1,572 $ 6,321 Gain and (losses) (realized/unrealized) Included in other comprehensive income 77 29 14 Sales — — (4,679 ) Settlements (21 ) (17 ) (84 ) Ending Balance $ 1,640 $ 1,584 $ 1,572
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	The following table sets forth certain unobservable inputs regarding the Company's financial instruments that are classified as Level 3 as of December 31st for the years indicated: Valuation Technique Fair Value Unobservable Inputs Range Weighted Average 2017 2016 2017 2016 2017 2016 (Dollars in thousands) Discounted cash flow methodology Pooled trust preferred securities $ 1,640 $ 1,584 Cumulative prepayment 0% - 61% 0% - 62% 2.5% 2.5% Cumulative default 5% - 100% 5% - 100% 12.4% 12.8% Loss given default 85% - 100% 85% - 100% 94.3% 94.2% Cure given default 0% - 75% 0% - 75% 60.9% 60.9% Appraisals of collateral (1) Collateral dependent impaired loans $ 33,567 $ 33,974 Other real estate owned and foreclosed assets $ 612 $ 4,173 (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various Level 3 inputs which are not identifiable. Appraisals may be adjusted by management for qualitative factors such as economic factors and estimated liquidation expenses. The range of these possible adjustments may vary.
Schedule of Fair Values and Related Carrying Amounts by Balance Sheet Grouping	The estimated fair values and related carrying amounts for assets and liabilities for which fair value is only disclosed are shown below as of the periods indicated: Fair Value Measurements at Reporting Date Using Carrying Value Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) December 31, 2017 (Dollars in thousands) Financial assets Securities held to maturity(a) U.S. Treasury securities $ 1,006 $ 1,035 $ — $ 1,035 $ — Agency mortgage-backed securities 204,768 205,823 — 205,823 — Agency collateralized mortgage obligations 262,998 258,408 — 258,408 — Single issuer trust preferred securities issued by banks 1,500 1,529 — 1,529 — Small business administration pooled securities 27,416 27,399 — 27,399 — Loans, net of allowance for loan losses(b) 6,261,343 6,116,051 — — 6,116,051 Federal Home Loan Bank stock(c) 11,597 11,597 — 11,597 — Cash surrender value of life insurance policies(d) 151,528 151,528 — 151,528 — Financial liabilities Deposit liabilities, other than time deposits(e) $ 6,084,952 $ 6,084,952 $ — $ 6,084,952 $ — Time certificates of deposits(f) 644,301 639,060 — 639,060 $ — Federal Home Loan Bank borrowings(f) 53,264 52,111 — 52,111 — Customer repurchase agreements and other short-term borrowings(f) 162,679 162,679 — — 162,679 Junior subordinated debentures(g) 73,073 74,680 — 74,680 — Subordinated debentures(f) 34,682 32,707 — — 32,707 Fair Value Measurements at Reporting Date Using Carrying Value Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) December 31, 2016 Financial assets (Dollars in thousands) Securities held to maturity(a) U.S. Treasury securities $ 1,007 $ 1,054 $ — $ 1,054 $ — Agency mortgage-backed securities 156,088 157,504 — 157,504 — Agency collateralized mortgage obligations 297,445 294,650 — 294,650 — Single issuer trust preferred securities issued by banks 1,500 1,544 — 1,544 — Small business administration pooled securities 31,036 30,898 — 30,898 — Loans, net of allowance for loan losses(b) 5,904,065 5,784,778 — — 5,784,778 Federal Home Loan Bank stock(c) 11,497 11,497 — 11,497 — Cash surrender value of life insurance policies(d) 144,503 144,503 — 144,503 — Financial liabilities Deposit liabilities, other than time deposits(e) $ 5,763,101 $ 5,763,101 $ — $ 5,763,101 $ — Time certificates of deposits(f) 649,152 647,038 — 647,038 — Federal Home Loan Bank borrowings(f) 50,819 50,898 — 50,898 — Customer repurchase agreements and other short-term borrowings(f) 176,913 176,913 — — 176,913 Junior subordinated debentures(g) 73,107 72,510 — 72,510 — Subordinated debentures(f) 34,635 34,241 — — 34,241 (a) The fair values presented are based on quoted market prices, where available. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments and/or discounted cash flow analysis. (b) Fair value is estimated by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities or cash flows. Additionally, this amount excludes collateral dependent impaired loans, which are deemed to be marked to fair value on a nonrecurring basis. (c) FHLB stock has no quoted market value and is carried at cost, therefore the carrying amount approximates fair value. (d) Cash surrender value of life insurance is recorded at its cash surrender value (or the amount that can be realized upon surrender of the policy), therefore carrying amount approximates fair value. (e) Fair value of demand deposits, savings and interest checking accounts and money market deposits is the amount payable on demand at the reporting date. (f) Fair value was determined by discounting anticipated future cash payments using rates currently available for instruments with similar remaining maturities. (g) Fair value was determined based upon market prices of securities with similar terms and maturities.

OTHER COMPREHENSIVE LOSS (Table

OTHER COMPREHENSIVE LOSS (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of Other Comprehensive Loss	The following table presents a reconciliation of the changes in the components of other comprehensive income (loss) for the dates indicated, including the amount of income tax (expense) benefit allocated to each component of other comprehensive income (loss): December 31, 2017 Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ (996 ) $ 321 $ (675 ) Less: net security gains reclassified into other noninterest income (expense) 3 (1 ) 2 Net change in fair value of securities available for sale (999 ) 322 (677 ) Change in fair value of cash flow hedges 307 (125 ) 182 Less: net cash flow hedge losses reclassified into interest on borrowings expense (1) (441 ) 180 (261 ) Net change in fair value of cash flow hedges 748 (305 ) 443 Net unamortized loss related to defined benefit pension and other postretirement adjustments arising during the period (995 ) 407 (588 ) Amortization of net actuarial losses 278 (113 ) 165 Amortization of net prior service cost 276 (113 ) 163 Net change in other comprehensive income for defined benefit postretirement plans (2) (441 ) 181 (260 ) Total other comprehensive loss $ (692 ) $ 198 $ (494 ) Year Ended December 31, 2016 Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ (1,858 ) $ 710 $ (1,148 ) Less: net security losses reclassified into other noninterest income (expense) (26 ) 11 (15 ) Net change in fair value of securities available for sale (1,832 ) 699 (1,133 ) Change in fair value of cash flow hedges 1,133 (453 ) 680 Less: net cash flow hedge losses reclassified into interest on borrowings expense (1) (2,520 ) 1,030 (1,490 ) Net change in fair value of cash flow hedges 3,653 (1,483 ) 2,170 Net unamortized loss related to defined benefit pension and other postretirement adjustments arising during the period (383 ) 157 (226 ) Amortization of net actuarial losses 238 (97 ) 141 Amortization of net prior service cost 276 (113 ) 163 Net change in other comprehensive income for defined benefit postretirement plans (2) 131 (53 ) 78 Total other comprehensive income $ 1,952 $ (837 ) $ 1,115 Year Ended December 31, 2015 Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ (3,757 ) $ 1,434 $ (2,323 ) Less: net security losses reclassified into other noninterest income (expense) (405 ) 165 (240 ) Net change in fair value of securities available for sale (3,352 ) 1,269 (2,083 ) Change in fair value of cash flow hedges (776 ) 299 (477 ) Less: Net cash flow hedge losses reclassified into interest on borrowings expense (1) (2,828 ) 1,152 (1,676 ) Net change in fair value of cash flow hedges 2,052 (853 ) 1,199 Net unamortized gain related to defined benefit pension and other postretirement adjustments arising during the period 438 (193 ) 245 Amortization of net actuarial losses 243 (99 ) 144 Amortization of net prior service cost 294 (119 ) 175 Net change in other comprehensive income for defined benefit postretirement plans (2) 975 (411 ) 564 Total other comprehensive loss $ (325 ) $ 5 $ (320 ) (1) Includes the amortization of the remaining balance of a realized but unrecognized gain, net of tax, from the termination of interest rate swaps in 2009. The original gain of $1.4 million , net of tax, will be recognized in earnings through December 2018 , the original maturity date of the swap. The balance of this gain had amortized to $137,000 , $281,000 , and $427,000 at December 31, 2017 , 2016 , and 2015 , respectively. (2) The amortization of prior service costs is included in the computation of net periodic pension costs as disclosed in Note 15 - Employee Benefit Plans .
Schedule of Accumulated Other Comprehensive Income (Loss), Net of Tax	Information on the Company's accumulated other comprehensive loss, net of tax, is comprised of the following components as of the periods indicated: Unrealized Gain (Loss) on Securities Unrealized Gain (Loss) on Cash Flow Hedge Deferred Gain on Hedge Transactions Defined Benefit Postretirement Plans Accumulated Other Comprehensive Income (Loss) (Dollars in Thousands) Beginning balance: January 1, 2015 $ 3,389 $ (3,298 ) $ 571 $ (2,794 ) $ (2,132 ) Net change in other comprehensive income (loss) (2,083 ) 1,343 (144 ) 564 (320 ) Ending balance: December 31, 2015 $ 1,306 $ (1,955 ) $ 427 $ (2,230 ) $ (2,452 ) Net change in other comprehensive income (loss) (1,133 ) 2,316 (146 ) 78 1,115 Ending balance: December 31, 2016 $ 173 $ 361 $ 281 $ (2,152 ) $ (1,337 ) Net change in other comprehensive income (loss) (677 ) 587 (144 ) (260 ) (494 ) Ending balance: December 31, 2017 $ (504 ) $ 948 $ 137 $ (2,412 ) $ (1,831 )

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Off-Balance Sheet Financial Instruments	The following table summarizes the above financial instruments at the dates indicated: As of December 31 2017 2016 (Dollars in thousands) Commitments to extend credit $ 2,443,478 $ 2,227,955 Standby letters of credit $ 15,534 $ 18,190 Deferred standby letter of credit fees $ 102 $ 108
Schedule of Minimum Future Lease Commitments	The Company leases office space, space for ATM locations, and certain branch locations under noncancelable operating leases. The following is a schedule of minimum future lease payments under such leases as of December 31, 2017 : (Dollars in thousands) 2018 $ 9,023 2019 8,808 2020 7,771 2021 6,508 2022 4,437 Thereafter 8,214 Total future minimum lease commitments $ 44,761

REGULATORY CAPITAL REQUIREMEN49

REGULATORY CAPITAL REQUIREMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	The Company’s and the Bank’s actual capital amounts and ratios as of December 31, 2017 and 2016 are also presented in the table that follows: Actual For Capital To Be Well Capitalized Amount Ratio Amount Ratio Amount Ratio December 31, 2017 (Dollars in thousands) Independent Bank Corp. Total capital (to risk weighted assets) $ 886,807 13.82 % $ 513,398 ≥ 8.0 % N/A N/A Common equity tier 1 capital (to risk weighted assets) $ 718,995 11.20 % $ 288,787 ≥ 4.5 % N/A N/A Tier 1 capital (to risk weighted assets) $ 789,992 12.31 % $ 385,049 ≥ 6.0 % N/A N/A Tier 1 capital (to average assets) $ 789,992 10.04 % $ 314,756 ≥ 4.0 % N/A N/A Rockland Trust Company Total capital (to risk weighted assets) $ 846,147 13.19 % $ 513,175 ≥ 8.0 % $ 641,469 ≥ 10.0 % Common equity tier 1 capital (to risk weighted assets) $ 784,014 12.22 % $ 288,661 ≥ 4.5 % $ 416,955 ≥ 6.5 % Tier 1 capital (to risk weighted assets) $ 784,014 12.22 % $ 384,881 ≥ 6.0 % $ 513,175 ≥ 8.0 % Tier 1 capital (to average assets) $ 784,014 9.97 % $ 314,630 ≥ 4.0 % $ 393,288 ≥ 5.0 % December 31, 2016 (Dollars in thousands) Independent Bank Corp. Total capital (to risk weighted assets) $ 824,265 13.60 % $ 484,942 ≥ 8.0 % N/A N/A Common equity tier 1 capital (to risk weighted assets) $ 656,080 10.82 % $ 272,780 ≥ 4.5 % N/A N/A Tier 1 capital (to risk weighted assets) $ 727,070 11.99 % $ 363,706 ≥ 6.0 % N/A N/A Tier 1 capital (to average assets) $ 727,070 9.77 % $ 297,748 ≥ 4.0 % N/A N/A Rockland Trust Company Total capital (to risk weighted assets) $ 788,320 13.01 % $ 484,834 ≥ 8.0 % $ 606,042 ≥ 10.0 % Common equity tier 1 capital (to risk weighted assets) $ 725,760 11.98 % $ 272,719 ≥ 4.5 % $ 393,927 ≥ 6.5 % Tier 1 capital (to risk weighted assets) $ 725,760 11.98 % $ 363,625 ≥ 6.0 % $ 484,834 ≥ 8.0 % Tier 1 capital (to average assets) $ 725,760 9.76 % $ 297,589 ≥ 4.0 % $ 371,986 ≥ 5.0 %

PARENT COMPANY FINANCIALS ONLY

PARENT COMPANY FINANCIALS ONLY (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule of Condensed Balance Sheets	BALANCE SHEETS December 31 2017 2016 (Dollars in thousands) Assets Cash(1) $ 48,131 $ 42,596 Investments in subsidiaries(2) 1,010,125 935,778 Prepaid income taxes 786 625 Deferred tax asset 96 216 Derivative instruments(1) 1,535 1,364 Total assets $ 1,060,673 $ 980,579 Liabilities and stockholders’ equity Dividends payable $ 8,786 $ 7,834 Junior subordinated debentures 73,073 73,107 Subordinated debentures 34,682 34,635 Other liabilities 323 313 Total liabilities 116,864 115,889 Stockholders’ equity 943,809 864,690 Total liabilities and stockholders’ equity $ 1,060,673 $ 980,579 (1) Entire balance eliminates in consolidation. (2) $1.0 billion and $933.6 million eliminate in consolidation at December 31, 2017 and 2016 , respectively.
Schedule of Condensed Statements of Income	STATEMENTS OF INCOME Years Ended December 31 2017 2016 2015 (Dollars in thousands) Income Dividends received from subsidiaries(1) $ 47,006 $ 44,598 $ 38,153 Interest income(2) 50 98 78 Total income 47,056 44,696 38,231 Expenses Interest expense 3,995 5,901 5,769 Other expenses — — 29 Total expenses 3,995 5,901 5,798 Income before income taxes and equity in undistributed income of subsidiaries 43,061 38,795 32,433 Income tax benefit (1,523 ) (1,791 ) (2,301 ) Income of parent company 44,584 40,586 34,734 Equity in undistributed income of subsidiaries 42,620 36,062 30,226 Net income $ 87,204 $ 76,648 $ 64,960 (1) Income of $67,000 , $62,000 and $55,000 was not eliminated in consolidation for the years ended December 31, 2017 , 2016 , and 2015 , respectively. (2) Entire balance eliminated in consolidation.
Schedule of Condensed Statements of Cash Flows	STATEMENTS OF CASH FLOWS Years Ended December 31 2017 2016 2015 (Dollars in thousands) Cash flows from operating activities Net income $ 87,204 $ 76,648 $ 64,960 Adjustments to reconcile net income to cash provided by operating activities Amortization (accretion) 12 (154 ) (150 ) Deferred income tax expense 51 678 3,266 Change in other assets (99 ) 423 7,488 Change in other liabilities (562 ) (5,532 ) (254 ) Equity in undistributed income of subsidiaries (42,620 ) (36,062 ) (30,226 ) Net cash provided by operating activities 43,986 36,001 45,084 Cash flows used in investing activities Cash paid for acquisitions, net of cash acquired (1) (4,834 ) (950 ) (51,680 ) Net cash used in investing activities (4,834 ) (950 ) (51,680 ) Cash flows used in financing activities Restricted stock awards issued, net of awards surrendered (1,422 ) (696 ) (657 ) Net proceeds from exercise of stock options 214 201 1,367 Proceeds from shares issued under the direct stock purchase plan 1,636 2,323 2,695 Common dividends paid (34,045 ) (29,711 ) (26,172 ) Net cash used in financing activities (33,617 ) (27,883 ) (22,767 ) Net increase (decrease) in cash and cash equivalents 5,535 7,168 (29,363 ) Cash and cash equivalents at the beginning of the year 42,596 35,428 64,791 Cash and cash equivalents at the end of the year $ 48,131 $ 42,596 $ 35,428 (1) The majority of the net assets acquired at the parent company represented each of the acquired companies' investments in their wholly owned subsidiaries, which were eliminated in consolidation at December 31, 2017 , 2016 , and 2015 , respectively.

SELECTED QUARTERLY FINANCIAL 51

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	First Quarter Second Quarter Third Quarter Fourth Quarter 2017 2016 2017 2016 2017 2016 2017 2016 (Dollars in thousands, except per share data) Interest income $ 64,407 $ 59,741 $ 68,133 $ 61,160 $ 71,778 $ 62,308 $ 72,876 $ 63,428 Interest expense 4,207 4,850 4,378 4,627 4,705 4,640 5,044 4,676 Net interest income 60,200 54,891 63,755 56,533 67,073 57,668 67,832 58,752 Provision for loan losses 600 525 1,050 600 — 950 1,300 4,000 Total noninterest income 18,912 19,155 21,398 21,095 20,770 20,416 21,914 21,762 Total noninterest expenses 48,773 46,482 52,809 47,146 51,310 46,857 51,467 51,637 Provision for income taxes 9,014 8,428 10,731 9,508 12,681 9,793 14,915 7,698 Net income $ 20,725 $ 18,611 $ 20,563 $ 20,374 $ 23,852 $ 20,484 $ 22,064 $ 17,179 Basic earnings per share $ 0.77 $ 0.71 $ 0.75 $ 0.77 $ 0.87 $ 0.78 $ 0.80 $ 0.64 Diluted earnings per share $ 0.76 $ 0.71 $ 0.75 $ 0.77 $ 0.87 $ 0.78 $ 0.80 $ 0.64 Weighted average common shares (basic) 27,029,640 26,275,323 27,257,799 26,304,129 27,436,792 26,324,316 27,445,739 26,710,029 Common stock equivalents 81,283 43,409 74,497 47,885 76,307 53,072 77,615 60,022 Weighted average common shares (diluted) 27,110,923 26,318,732 27,332,296 26,352,014 27,513,099 26,377,388 27,523,354 26,770,051 Unusual or infrequently occurring items Items within noninterest expense Loss on extinguishment of debt $ — $ 437 $ — $ — $ — $ — $ — $ — Merger and acquisition expense 484 334 2,909 206 — 151 — 4,764 Total $ 484 $ 771 $ 2,909 $ 206 $ — $ 151 $ — $ 4,764 Items within provision for income taxes 2017 Tax Act: revaluation of net deferred tax assets $ — $ — $ — $ — $ — $ — $ 1,895 $ — 2017 Tax Act: revaluation of LIHTC investments $ — $ — $ — $ — $ — $ — $ 466 $ — Total $ — $ — $ — $ — $ — $ — $ 2,361 $ —

TRANSACTIONS WITH RELATED PAR52

TRANSACTIONS WITH RELATED PARTIES Activity of Loans to Related Parties (Tables)	12 Months Ended
	Dec. 31, 2017
Related Party Transaction [Line Items]
Schedule of Related Party Transactions [Table Text Block]	The following information represents annual activity of loans to related parties for the periods indicated: 2017 2016 (Dollars in thousands) Principal balance of loans outstanding at beginning of year $ 22,795 $ 24,653 Loan advances (1) 36,800 1,718 Loan payments/payoffs (7,137 ) (3,576 ) Principal balance of loans outstanding at end of year $ 52,458 $ 22,795 (1) Includes $31.3 million of loans associated with a newly appointed director during the year, which represent the outstanding loan balances at the effective date of appointment.

SUMMARY OF SIGNIFICANT ACCOUN53

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Core deposit intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life	10 years
Noncompete Agreements [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life	1 year
Noncompete Agreements [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life	3 years
Customer Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life	10 years
Lease Agreements [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life	3 years
Lease Agreements [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life	29 years
Residential Building [Member] | Lender Concentration Risk [Member] | Loans Receivable [Member]
Finite-Lived Intangible Assets [Line Items]
Concentration Risk, Percentage	15.40%	15.40%

SUMMARY OF SIGNIFICANT ACCOUN54

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details Textual)	12 Months Ended
	Dec. 31, 2017USD ($)centerbranch	Dec. 31, 2016USD ($)
Accounting Policies [Line Items]
Reserve for unfunded loan commitments | $	$ 972,000	$ 954,000
Maximum [Member]
Accounting Policies [Line Items]
Lease Option Period	15 years
Loans Receivable [Member] | Lender Concentration Risk [Member] | Residential Building [Member]
Accounting Policies [Line Items]
Loans of nonresidential buildings to total loan portfolio	15.40%	15.40%
Full Service Retail Branch [Member] | Bank [Member]
Accounting Policies [Line Items]
Number of branches | branch	84
Limited Service Retail Branch [Member] | Bank [Member]
Accounting Policies [Line Items]
Number of branches | branch	2
Commercial Banking Center [Member] | Bank [Member]
Accounting Policies [Line Items]
Number of centers	13
Investment Management Office [Member] | Bank [Member]
Accounting Policies [Line Items]
Number of centers	6
Mortgage Lending Center [Member] | Bank [Member]
Accounting Policies [Line Items]
Number of centers	1

ACQUISITIONS (Details)

ACQUISITIONS (Details) - USD ($) $ in Thousands	Dec. 31, 2017	May 12, 2017	Dec. 31, 2016	Nov. 10, 2016	Dec. 31, 2015
Assets
Goodwill	$ 231,806		$ 221,526		$ 201,083
Island Bancorp, Inc. [Member]
Assets
Cash		$ 11,137
Loans		155,551
Premises and equipment		5,828
Goodwill		10,280
Core deposit intangible		2,964
Other assets		4,629
Total assets acquired		190,389
Liabilities
Deposits		159,580
Borrowings		2,475
Other liabilities		18
Total liabilities assumed		162,073
Purchase price		$ 28,316
New England Bancorp, Inc. [Member]
Assets
Cash				$ 9,679
Loans				225,731
Premises and equipment				201
Goodwill				20,443
Core deposit intangible				670
Other assets				19,197
Total assets acquired				275,921
Liabilities
Deposits				175,686
Borrowings				51,150
Other liabilities				7,344
Total liabilities assumed				234,180
Purchase price				$ 41,741

ACQUISITIONS (Details 2)

ACQUISITIONS (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Island Bancorp, Inc. [Member]
Business Acquisition [Line Items]
Net interest income after provision for loan losses	$ 258,017	$ 227,429
Net income	$ 90,025	78,150
New England Bancorp, Inc. [Member]
Business Acquisition [Line Items]
Net interest income after provision for loan losses		228,927	$ 221,252
Net income		$ 80,411	$ 65,623

ACQUISITIONS (Details Textual)

ACQUISITIONS (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	May 12, 2017	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Nov. 10, 2016
Business Acquisition [Line Items]
Acquisition Related Costs		$ 0	$ 0	$ 2,909	$ 484	$ 4,764	$ 151	$ 206	$ 334	$ 3,393	$ 5,455	$ 10,501
Island Bancorp, Inc. [Member]
Business Acquisition [Line Items]
Equity Interest Issued or Issuable Shareholders Option To Receive, Cash Per Share	$ 500
Number of shares of company stock issued for each share of Central common stock (in shares)	9.525
Value of shares of company stock issued for each share of acquiree stock (in dollars per share)	$ 605.31
Company's closing price per share (in dollars per share)	$ 63.55
Business transaction value	$ 28,300
Cost of acquired entity, percentage cash	20.00%
Business Acquisition, Cost of Acquired Entity, Percentage Stock Consideration	80.00%
Cost of acquired entity, cash paid	$ 4,800
Consideration Transferred, Equity Interests Issued and Issuable	$ 23,500
Increase in acquirer outstanding shares	369,286
Acquisition Related Costs										3,200
Loans acquired	$ 155,551
Combination of INDB and Island Bancorp, Inc. [Member]
Business Acquisition [Line Items]
Acquisition Related Costs										2,600
New England Bancorp, Inc. [Member]
Business Acquisition [Line Items]
Number of shares of company stock issued for each share of Central common stock (in shares)													0.25
Value of shares of company stock issued for each share of acquiree stock (in dollars per share)													$ 15.14
Company's closing price per share (in dollars per share)													$ 60.55
Business transaction value													$ 41,700
Increase in acquirer outstanding shares													672,665
Acquisition Related Costs										$ 5,000
Loans acquired													$ 225,731
Combination of INDB and New England Bancorp, Inc. [Member]
Business Acquisition [Line Items]
Acquisition Related Costs											$ 6,300

SECURITIES (Details 1)

SECURITIES (Details 1) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Available-for-sale Securities:
Amortized Cost	$ 448,219	$ 363,366
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax	3,740	3,890
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(4,461)	(3,612)
Fair Value	447,498	363,644
Held-to-maturity Securities:
Amortized Cost	497,688	487,076
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	2,429	3,556
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(5,923)	(4,982)
Fair Value	494,194	485,650
Available-for-sale Securities and Held-to-maturity Securities:
Amortized Cost	945,907	850,442
Gross Unrealized Gains	6,169	7,446
Gross Unrealized Losses	(10,384)	(8,594)
Fair Value	941,692	849,294
U.S. Government agency securities
Available-for-sale Securities:
Amortized Cost	35,475	24,006
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	86	238
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(131)	0
Fair Value	35,430	24,244
U.S. treasury securities [Member]
Held-to-maturity Securities:
Amortized Cost	1,006	1,007
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	29	47
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Fair Value	1,035	1,054
Agency mortgage-backed securities [Member]
Available-for-sale Securities:
Amortized Cost	214,934	173,268
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	1,897	2,852
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(1,067)	(736)
Fair Value	215,764	175,384
Held-to-maturity Securities:
Amortized Cost	204,768	156,088
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	1,791	2,274
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(736)	(858)
Fair Value	205,823	157,504
Agency collateralized mortgage obligations [Member]
Available-for-sale Securities:
Amortized Cost	124,098	101,094
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	78	106
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(2,164)	(1,332)
Fair Value	122,012	99,868
Held-to-maturity Securities:
Amortized Cost	262,998	297,445
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	397	1,002
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(4,987)	(3,797)
Fair Value	258,408	294,650
State, county, and municipal securities [Member]
Available-for-sale Securities:
Amortized Cost	2,237	3,743
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	37	50
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	0	0
Fair Value	2,274	3,793
Single issuer trust preferred securities issued by banks [Member]
Available-for-sale Securities:
Amortized Cost	2,012	2,311
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	4	3
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	0	(3)
Fair Value	2,016	2,311
Held-to-maturity Securities:
Amortized Cost	1,500	1,500
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	29	44
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Fair Value	1,529	1,544
Pooled trust preferred securities issued by banks and insurers
Available-for-sale Securities:
Amortized Cost	2,179	2,200
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	0	0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(539)	(616)
Fair Value	1,640	1,584
Small Business Administration Pooled Securities [Member]
Available-for-sale Securities:
Amortized Cost	47,852	37,561
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	44	0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(118)	(372)
Fair Value	47,778	37,189
Held-to-maturity Securities:
Amortized Cost	27,416	31,036
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	183	189
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(200)	(327)
Fair Value	27,399	30,898
Marketable securities [Member]
Available-for-sale Securities:
Amortized Cost	19,432	19,183
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	1,594	641
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(442)	(553)
Fair Value	$ 20,584	$ 19,271

SECURITIES (Details 3)

SECURITIES (Details 3) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Available for Sale, Amortized Cost
Amortized Cost	$ 448,219	$ 363,366
Available for Sale, Fair Value
Securities - available for sale	447,498	363,644
Held to Maturity, Amortized Cost
Amortized Cost	497,688	487,076
Held to Maturity, Fair Value
Fair Value	494,194	$ 485,650
Debt Securities [Member]
Available for Sale, Amortized Cost
Due in one year or less	3,213
Due after one year to five years	49,241
Due after five to ten years	107,417
Due after ten years	268,916
Amortized Cost	428,787
Available for Sale, Fair Value
Due in one year or less	3,215
Due in one year or less	49,312
Due after five to ten years	107,402
Due after ten years	266,985
Securities - available for sale	426,914
Held to Maturity, Amortized Cost
Due in one year or less	0
Due after one year to five years	15,636
Due after five to ten years	16,801
Due after ten years	465,251
Amortized Cost	497,688
Held to Maturity, Fair Value
Due in one year or less	0
Due after one year to five years	15,711
Due after five to ten years	17,098
Due after ten years	461,385
Fair Value	494,194
Marketable securities [Member]
Available for Sale, Amortized Cost
Available-for-sale Equity Securities, Amortized Cost Basis	19,432
Available for Sale, Fair Value
Assets Designated to Closed Block, Equity Securities, Available-for-sale, at Fair Value	20,584
Held to Maturity, Amortized Cost
Amortized Cost	0
Held to Maturity, Fair Value
Fair Value	$ 0

SECURITIES (Details 4)

SECURITIES (Details 4) $ in Thousands	Dec. 31, 2017USD ($)holding	Dec. 31, 2016USD ($)holding
Summary of gross unrealized losses and fair value of investments
No of holdings | holding	163	121
Fair value, less than 12 months	$ 475,739	$ 444,471
Fair value, 12 months or longer	193,298	56,356
Fair value, Total	669,037	500,827
Unrealized losses, Total	(10,384)	(8,594)
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months	(3,465)	(5,510)
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months	$ (6,919)	$ (3,084)
US Government Agencies Debt Securities [Member]
Summary of gross unrealized losses and fair value of investments
No of holdings | holding	4
Fair value, less than 12 months	$ 24,343
Fair value, 12 months or longer	0
Fair value, Total	24,343
Unrealized losses, Total	(131)
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months	$ (131)
Agency mortgage-backed securities [Member]
Summary of gross unrealized losses and fair value of investments
No of holdings | holding	84	57
Fair value, less than 12 months	$ 235,411	$ 137,949
Fair value, 12 months or longer	14,886	0
Fair value, Total	250,297	137,949
Unrealized losses, Total	(1,803)	(1,594)
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months	(1,493)	(1,594)
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months	$ (310)	$ 0
Agency collateralized mortgage obligations [Member]
Summary of gross unrealized losses and fair value of investments
No of holdings | holding	42	32
Fair value, less than 12 months	$ 178,142	$ 243,051
Fair value, 12 months or longer	159,506	47,403
Fair value, Total	337,648	290,454
Unrealized losses, Total	(7,151)	(5,129)
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months	(1,579)	(3,140)
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months	$ (5,572)	$ (1,989)
Single issuer trust preferred securities issued by banks and insurers
Summary of gross unrealized losses and fair value of investments
No of holdings | holding		1
Fair value, less than 12 months		$ 0
Fair value, 12 months or longer		1,036
Fair value, Total		1,036
Unrealized losses, Total		(3)
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months		0
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months		$ (3)
Pooled trust preferred securities issued by banks and insurers
Summary of gross unrealized losses and fair value of investments
No of holdings | holding	1	1
Fair value, less than 12 months	$ 0	$ 0
Fair value, 12 months or longer	1,640	1,583
Fair value, Total	1,640	1,583
Unrealized losses, Total	(539)	(616)
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months	0	0
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months	$ (539)	$ (616)
Small Business Administration Pooled Securities [Member]
Summary of gross unrealized losses and fair value of investments
No of holdings | holding	4	5
Fair value, less than 12 months	$ 34,553	$ 59,846
Fair value, 12 months or longer	9,647	0
Fair value, Total	44,200	59,846
Unrealized losses, Total	(318)	(699)
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months	(223)	$ (699)
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months	$ (95)
Marketable securities [Member]
Summary of gross unrealized losses and fair value of investments
No of holdings | holding	28	25
Fair value, less than 12 months	$ 3,290	$ 3,625
Fair value, 12 months or longer	7,619	6,334
Fair value, Total	10,909	9,959
Unrealized losses, Total	(442)	(553)
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months	(39)	(77)
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months	$ (403)	$ (476)

SECURITIES (Details 7)

SECURITIES (Details 7) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Net impairment losses recognized in earnings on securities	$ 0	$ 0	$ 0

SECURITIES (Details 8)

SECURITIES (Details 8) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Less
Securities sold during the period	$ 10,000
Balance at end of period	$ 0

SECURITIES (Details Textual)

SECURITIES (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Trading Securities	$ 1,324,000	$ 804,000
Callable securities in investment portfolio	9,400,000
Investment securities pledged	547,200,000	482,100,000
Investments in obligations of individual states, counties or municipalities which exceed 10% of equity		0
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	0	0	$ 0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held	$ 0	$ 0	$ 0

Allowance Allocations (Details

Allowance Allocations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				$ 61,566				$ 55,825	$ 61,566	$ 55,825	$ 55,100
Charge-offs									(6,209)	(3,472)	(4,918)
Recoveries									2,336	3,138	4,143
Provision (benefit)	$ 1,300	$ 0	$ 1,050	600	$ 4,000	$ 950	$ 600	525	2,950	6,075	1,500
Ending balance	60,643				61,566				60,643	61,566	55,825
Ending balance: individually evaluated for impairment	1,342				5,214				1,342	5,214	1,930
Ending balance: collectively evaluated for impairment	59,301				56,352				59,301	56,352	53,895
Financing receivables ending balance:
Financing Receivable, Collectively Evaluated for Impairment	6,269,729				5,903,916				6,269,729	5,903,916	5,475,716
Individually evaluated for impairment	72,801				77,297				72,801	77,297	51,410
Financing Receivable, Net	4,539,256				4,355,968				4,539,256	4,355,968
Loans Receivable, Gross, Commercial and Industrial	888,528				902,053				888,528	902,053
Loans Receivable, Gross, Commercial, Mortgage	3,116,561				3,010,798				3,116,561	3,010,798
Total loans	6,355,553				5,999,605				6,355,553	5,999,605	5,547,721	[1]
Loans and Leases Receivable, Gross, Consumer, Other	9,880				11,064				9,880	11,064
Loans Receivable, Gross, Commercial, Construction	401,797				320,391				401,797	320,391
Small Business	132,370				122,726				132,370	122,726
Loans and Leases Receivable, Gross, Consumer, Mortgage	754,329				644,426				754,329	644,426
Commercial and Industrial [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				16,921				13,802	16,921	13,802	15,573
Charge-offs									(3,891)	(593)	(2,010)
Recoveries									615	859	1,593
Provision (benefit)									(389)	2,853	(1,354)
Ending balance	13,256				16,921				13,256	16,921	13,802
Ending balance: individually evaluated for impairment	10				3,661				10	3,661	183
Ending balance: collectively evaluated for impairment	13,246				13,260				13,246	13,260	13,619
Financing receivables ending balance:
Financing Receivable, Collectively Evaluated for Impairment	853,885				862,875				853,885	862,875	838,129
Individually evaluated for impairment	34,643				39,178				34,643	39,178	5,147
Financing Receivable, Net	888,528				902,053				888,528	902,053
Total loans	888,528				902,053				888,528	902,053	843,276
Commercial Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				30,369				27,327	30,369	27,327	25,873
Charge-offs									(39)	(414)	(330)
Recoveries									385	564	1,073
Provision (benefit)									738	2,892	711
Ending balance	31,453				30,369				31,453	30,369	27,327
Ending balance: individually evaluated for impairment	42				196				42	196	204
Ending balance: collectively evaluated for impairment	31,411				30,173				31,411	30,173	27,123
Financing receivables ending balance:
Financing Receivable, Collectively Evaluated for Impairment	3,093,945				2,983,642				3,093,945	2,983,642	2,619,294
Individually evaluated for impairment	16,638				16,813				16,638	16,813	22,986
Financing Receivable, Net	3,116,561				3,010,798				3,116,561	3,010,798
Total loans	3,116,561				3,010,798				3,116,561	3,010,798	2,653,434
Construction Loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				4,522				5,366	4,522	5,366	3,945
Charge-offs									0	0	0
Recoveries									0	0
Provision (benefit)									1,176	(844)	1,421
Ending balance	5,698				4,522				5,698	4,522	5,366
Ending balance: individually evaluated for impairment	0				0				0	0	0
Ending balance: collectively evaluated for impairment	5,698				4,522				5,698	4,522	5,366
Financing receivables ending balance:
Financing Receivable, Collectively Evaluated for Impairment	401,797				320,391				401,797	320,391	373,064
Individually evaluated for impairment	0				0				0	0	304
Financing Receivable, Net	401,797				320,391				401,797	320,391
Total loans	401,797				320,391				401,797	320,391	373,368
Small Business [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				1,502				1,264	1,502	1,264	1,171
Charge-offs									(302)	(228)	(267)
Recoveries									114	195	264
Provision (benefit)									263	271	96
Ending balance	1,577				1,502				1,577	1,502	1,264
Ending balance: individually evaluated for impairment	1				8				1	8	4
Ending balance: collectively evaluated for impairment	1,576				1,494				1,576	1,494	1,260
Financing receivables ending balance:
Financing Receivable, Collectively Evaluated for Impairment	131,667				121,855				131,667	121,855	95,225
Individually evaluated for impairment	703				871				703	871	1,021
Financing Receivable, Net	132,370				122,726				132,370	122,726
Total loans	132,370				122,726				132,370	122,726	96,246
Residential Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				2,621				2,590	2,621	2,590	2,834
Charge-offs									(207)	(28)	(285)
Recoveries									31	299	133
Provision (benefit)									377	(240)	(92)
Ending balance	2,822				2,621				2,822	2,621	2,590
Ending balance: individually evaluated for impairment	1,007				1,086				1,007	1,086	1,278
Ending balance: collectively evaluated for impairment	1,815				1,535				1,815	1,535	1,312
Financing receivables ending balance:
Financing Receivable, Collectively Evaluated for Impairment	733,809				622,392				733,809	622,392	614,014
Individually evaluated for impairment	13,684				14,175				13,684	14,175	15,405
Total loans	754,329				644,426				754,329	644,426	638,606
Home Equity [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				5,238				4,889	5,238	4,889	4,956
Charge-offs									(276)	(602)	(710)
Recoveries									198	141	356
Provision (benefit)									230	810	287
Ending balance	5,390				5,238				5,390	5,238	4,889
Ending balance: individually evaluated for impairment	265				242				265	242	238
Ending balance: collectively evaluated for impairment	5,125				4,996				5,125	4,996	4,651
Financing receivables ending balance:
Financing Receivable, Collectively Evaluated for Impairment	1,045,053				982,095				1,045,053	982,095	921,563
Individually evaluated for impairment	6,826				5,863				6,826	5,863	5,989
Total loans	1,052,088				988,147				1,052,088	988,147	927,803
Consumer Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				$ 393				$ 587	393	587	748
Charge-offs									(1,494)	(1,607)	(1,316)
Recoveries									993	1,080	724
Provision (benefit)									555	333	431
Ending balance	447				393				447	393	587
Ending balance: individually evaluated for impairment	17				21				17	21	23
Ending balance: collectively evaluated for impairment	430				372				430	372	564
Financing receivables ending balance:
Financing Receivable, Collectively Evaluated for Impairment	9,573				10,666				9,573	10,666	14,427
Individually evaluated for impairment	307				397				307	397	558
Total loans	9,880				11,064				9,880	11,064	14,988
Receivables Acquired with Deteriorated Credit Quality [Member]
Financing receivables ending balance:
Financing Receivable, Net	13,023				18,392				13,023	18,392	20,595
Receivables Acquired with Deteriorated Credit Quality [Member] | Commercial and Industrial [Member]
Financing receivables ending balance:
Financing Receivable, Net	0				0				0	0	0
Receivables Acquired with Deteriorated Credit Quality [Member] | Commercial Real Estate [Member]
Financing receivables ending balance:
Financing Receivable, Net	5,978				10,343				5,978	10,343	11,154
Receivables Acquired with Deteriorated Credit Quality [Member] | Construction Loans [Member]
Financing receivables ending balance:
Financing Receivable, Net	0				0				0	0	0
Receivables Acquired with Deteriorated Credit Quality [Member] | Small Business [Member]
Financing receivables ending balance:
Financing Receivable, Net	0				0				0	0	0
Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Real Estate [Member]
Financing receivables ending balance:
Financing Receivable, Net	6,836				7,859				6,836	7,859	9,187
Receivables Acquired with Deteriorated Credit Quality [Member] | Home Equity [Member]
Financing receivables ending balance:
Financing Receivable, Net	209				189				209	189	251
Receivables Acquired with Deteriorated Credit Quality [Member] | Consumer Portfolio Segment [Member]
Financing receivables ending balance:
Financing Receivable, Net	$ 0				$ 1				$ 0	$ 1	$ 3
[1]	The amount of net deferred costs on originated loans included in the ending balance was $6.1 million, $5.1 million, and $4.3 million at December 31, 2017, 2016, and 2015, respectively. Net unamortized discounts on acquired loans not deemed to be PCI included in the ending balance was $9.4 million, $8.6 million, and $6.6 million at December 31, 2017, 2016, and 2015, respectively.

Internal Risk Rating Categories

Internal Risk Rating Categories for Commercial Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	$ 4,539,256	$ 4,355,968
Commercial and Industrial [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	888,528	902,053
Commercial Real Estate [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	3,116,561	3,010,798
Construction Loans [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	401,797	320,391
Small Business [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	132,370	122,726
Pass [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	4,345,232	4,097,798
Pass [Member] | Commercial and Industrial [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	806,331	783,825
Pass [Member] | Commercial Real Estate [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	3,007,672	2,876,570
Pass [Member] | Construction Loans [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	400,964	317,099
Pass [Member] | Small Business [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	130,265	120,304
Potential weakness [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	87,822	134,039
Potential weakness [Member] | Commercial and Industrial [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	16,563	46,176
Potential weakness [Member] | Commercial Real Estate [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	69,788	84,641
Potential weakness [Member] | Construction Loans [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	0	1,363
Potential weakness [Member] | Small Business [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	1,471	1,859
Definite weakness [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	99,516	121,640
Definite weakness [Member] | Commercial and Industrial [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	59,415	71,991
Definite weakness [Member] | Commercial Real Estate [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	38,637	47,164
Definite weakness [Member] | Construction Loans [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	833	1,929
Definite weakness [Member] | Small Business [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	631	556
Parital loss probable [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	6,686	2,491
Parital loss probable [Member] | Commercial and Industrial [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	6,219	61
Parital loss probable [Member] | Commercial Real Estate [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	464	2,423
Parital loss probable [Member] | Construction Loans [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	0	0
Parital loss probable [Member] | Small Business [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	3	7
Definite loss [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	0	0
Definite loss [Member] | Commercial and Industrial [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	0	0
Definite loss [Member] | Commercial Real Estate [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	0	0
Definite loss [Member] | Construction Loans [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	0	0
Definite loss [Member] | Small Business [Member]
Internal risk-rating categories for the Company's commercial portfolio
Financing Receivable, Net	$ 0	$ 0

Weighted Average FICO Scores &

Weighted Average FICO Scores & weighted Average Combined LTV Ratios (Details) - score		Dec. 31, 2017	Dec. 31, 2016
Residential Portfolio Segment [Member]
Weighted average FICO scores and the weighted average combined LTV Ratio
FICO score (re-scored)	[1]	745	743
Financing Receivable With Credit Quality Of Loan Based Upon the Weighted Average Loan-To-Value Ratio		59.20%	63.20%
Home Equity [Member]
Weighted average FICO scores and the weighted average combined LTV Ratio
FICO score (re-scored)		766	767
Financing Receivable With Credit Quality Of Loan Based Upon the Weighted Average Loan-To-Value Ratio		50.10%	55.90%
[1]	The average FICO scores at December 31, 2017 are based upon rescores available from August 2017 and origination score data for loans booked between September and December 2017. The average FICO scores at December 31, 2016 are based upon rescores available from November 2016 and origination score data for loans booked in December 2016.

Summary of Nonaccrual Loans (De

Summary of Nonaccrual Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable Impaired [Line Items]
TDRs on nonaccrual status	$ 6,067	$ 5,199
Financing Receivable, Recorded Investment, Nonaccrual Status	49,630	57,405
Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	32,055	37,455
Commercial Real Estate [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	3,123	6,266
Small Business [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	230	302
Residential Real Estate [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	8,129	7,782
Home Equity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	6,022	5,553
Consumer Portfolio Segment [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 71	$ 47

Age Analysis of Past Due Financ

Age Analysis of Past Due Financing receivables (Details) $ in Thousands	Dec. 31, 2017USD ($)loan	Dec. 31, 2016USD ($)loan	Dec. 31, 2015USD ($)
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	319	301
Number of Loans 60-89 Days | loan	48	72
Number of Loans 90 Days or More | loan	92	91
Number of Loans Total Past Due | loan	459	464
Principal Balance Total Past Due	$ 48,746	$ 19,911
Current	6,306,807	5,979,694
Total loans	6,355,553	5,999,605	$ 5,547,721	[1]
Recorded Investment >90 Days and Accruing	$ 8	$ 2
Commercial and Industrial [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	2	8
Number of Loans 60-89 Days | loan	2	32
Number of Loans 90 Days or More | loan	14	6
Number of Loans Total Past Due | loan	18	46
Principal Balance Total Past Due	$ 32,572	$ 2,833
Current	855,956	899,220
Total loans	888,528	902,053	843,276
Recorded Investment >90 Days and Accruing	$ 0	$ 0
Commercial Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	7	5
Number of Loans 60-89 Days | loan	0	8
Number of Loans 90 Days or More | loan	9	8
Number of Loans Total Past Due | loan	16	21
Principal Balance Total Past Due	$ 4,853	$ 6,580
Current	3,111,708	3,004,218
Total loans	3,116,561	3,010,798	2,653,434
Recorded Investment >90 Days and Accruing	$ 0	$ 0
Construction Loans [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	0	0
Number of Loans 60-89 Days | loan	0	0
Number of Loans 90 Days or More | loan	0	0
Number of Loans Total Past Due | loan	0	0
Principal Balance Total Past Due	$ 0	$ 0
Current	401,797	320,391
Total loans	401,797	320,391	373,368
Recorded Investment >90 Days and Accruing	$ 0	$ 0
Small Business [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	17	9
Number of Loans 60-89 Days | loan	11	0
Number of Loans 90 Days or More | loan	10	19
Number of Loans Total Past Due | loan	38	28
Principal Balance Total Past Due	$ 540	$ 463
Current	131,830	122,263
Total loans	132,370	122,726	96,246
Recorded Investment >90 Days and Accruing	$ 0	$ 0
Residential Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	6	11
Number of Loans 60-89 Days | loan	13	9
Number of Loans 90 Days or More | loan	22	27
Number of Loans Total Past Due | loan	41	47
Principal Balance Total Past Due	$ 6,726	$ 6,734
Current	747,603	637,692
Total loans	754,329	644,426	638,606
Recorded Investment >90 Days and Accruing	$ 0	$ 0
Home Equity [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	22	19
Number of Loans 60-89 Days | loan	6	11
Number of Loans 90 Days or More | loan	20	16
Number of Loans Total Past Due | loan	48	46
Principal Balance Total Past Due	$ 3,786	$ 3,093
Current	1,048,302	985,054
Total loans	1,052,088	988,147	927,803
Recorded Investment >90 Days and Accruing	$ 0	$ 0
Consumer Portfolio Segment [Member]
Age Analysis of Past Due Financing Receivables
Number of Loans 30-59 Days | loan	265	249
Number of Loans 60-89 Days | loan	16	12
Number of Loans 90 Days or More | loan	17	15
Number of Loans Total Past Due | loan	298	276
Principal Balance Total Past Due	$ 269	$ 208
Current	9,611	10,856
Total loans	9,880	11,064	$ 14,988
Recorded Investment >90 Days and Accruing	8	2
Financing Receivables, 30 to 59 Days Past Due [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	5,971	4,519
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial and Industrial [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	195	100
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	3,060	1,518
Financing Receivables, 30 to 59 Days Past Due [Member] | Construction Loans [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Small Business [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	339	323
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	870	1,277
Financing Receivables, 30 to 59 Days Past Due [Member] | Home Equity [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	1,310	1,117
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	197	184
Financing Receivables, 60 to 89 Days Past Due [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	3,377	4,944
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial and Industrial [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	370	253
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	0	1,957
Financing Receivables, 60 to 89 Days Past Due [Member] | Construction Loans [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Small Business [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	144	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	2,385	1,950
Financing Receivables, 60 to 89 Days Past Due [Member] | Home Equity [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	451	767
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	27	17
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	39,398	10,448
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial and Industrial [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	32,007	2,480
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	1,793	3,105
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Construction Loans [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Small Business [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	57	140
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential Real Estate [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	3,471	3,507
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Home Equity [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	2,025	1,209
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Age Analysis of Past Due Financing Receivables
Principal Balance Total Past Due	$ 45	$ 7
[1]	The amount of net deferred costs on originated loans included in the ending balance was $6.1 million, $5.1 million, and $4.3 million at December 31, 2017, 2016, and 2015, respectively. Net unamortized discounts on acquired loans not deemed to be PCI included in the ending balance was $9.4 million, $8.6 million, and $6.6 million at December 31, 2017, 2016, and 2015, respectively.

TDR's and Other Pertinent Infor

TDR's and Other Pertinent Information (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Summary of Troubled Debt Restructurings and other pertinent information
TDRs on accrual status	$ 25,852	$ 27,093
TDRs on nonaccrual status	6,067	5,199
Total TDRs	31,919	32,292
Amount of specific reserves included in the allowance for loan loss associated with TDRs:	1,342	1,417
Additional commitments to lend to a borrower who has been a party to a TDR:	$ 487	$ 1,378

Modification which Occurred Dur

Modification which Occurred During the Period & Change in Recorded Investment(Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)contract	Dec. 31, 2016USD ($)contract	Dec. 31, 2015USD ($)contract
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	54	50	44
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 8,130	$ 7,663	$ 6,085
TROUBLED DEBT RESTRUCTURINGS:
Post-Modification Outstanding Recorded Investment	$ 8,175	$ 7,705	$ 6,112
Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract		6
Financing Receivable, Modifications, Pre-Modification Recorded Investment		$ 153
TROUBLED DEBT RESTRUCTURINGS:
Post-Modification Outstanding Recorded Investment		$ 153
Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	17	13	8
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 1,985	$ 932	$ 694
TROUBLED DEBT RESTRUCTURINGS:
Post-Modification Outstanding Recorded Investment	$ 1,988	$ 932	$ 694
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	10	8	8
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 1,284	$ 1,808	$ 843
TROUBLED DEBT RESTRUCTURINGS:
Post-Modification Outstanding Recorded Investment	$ 1,326	$ 1,850	$ 870
Small Business [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	9	3	9
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 369	$ 188	$ 293
TROUBLED DEBT RESTRUCTURINGS:
Post-Modification Outstanding Recorded Investment	$ 369	$ 188	$ 293
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	6	10	6
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 2,705	$ 2,959	$ 2,941
TROUBLED DEBT RESTRUCTURINGS:
Post-Modification Outstanding Recorded Investment	$ 2,705	$ 2,959	$ 2,941
Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	12	10	13
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 1,787	$ 1,623	$ 1,314
TROUBLED DEBT RESTRUCTURINGS:
Post-Modification Outstanding Recorded Investment	$ 1,787	$ 1,623	$ 1,314

Post-modification balance of TD

Post-modification balance of TDRs Listed by type of Modification(Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans, Allowance for Loan Losses and Credit Quality [Abstract]
Extended maturity	$ 5,881	$ 5,044	$ 2,936
Adjusted interest rate	0	92
Combination rate and maturity	568	1,035	2,199
Court ordered concession	1,726	1,534	977
Total	$ 8,175	$ 7,705	$ 6,112

TDR's that have subsequent defa

TDR's that have subsequent default (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)contract	Dec. 31, 2016USD ($)contract	Dec. 31, 2015USD ($)contract
TROUBLED DEBT RESTRUCTURINGS THAT SUBSEQUENTLY DEFAULTED:
Recorded Investment | $	$ 122	$ 249	$ 1,267
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | contract	1	1	7
Commercial And Industrial [Member]
TROUBLED DEBT RESTRUCTURINGS THAT SUBSEQUENTLY DEFAULTED:
Recorded Investment | $	$ 122	$ 0	$ 339
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | contract	1	0	3
Commercial Real Estate [Member]
TROUBLED DEBT RESTRUCTURINGS THAT SUBSEQUENTLY DEFAULTED:
Recorded Investment | $	$ 0	$ 249	$ 502
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | contract	0	1	1
Residential Real Estate [Member]
TROUBLED DEBT RESTRUCTURINGS THAT SUBSEQUENTLY DEFAULTED:
Recorded Investment | $	$ 0		$ 326
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | contract	0		2
Home Equity Line of Credit [Member]
TROUBLED DEBT RESTRUCTURINGS THAT SUBSEQUENTLY DEFAULTED:
Recorded Investment | $	$ 0	$ 0	$ 100
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | contract	0	0	1

Impaired Loan Information by Po

Impaired Loan Information by Portfolio (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 1,342	$ 5,214	$ 1,930
Related Allowance	1,342	5,214	1,930
Recorded Investment	72,801	77,297	51,410
Unpaid Principal Balance	79,276	81,071	54,822
Average Recorded Investment	76,180	77,209	51,678
Interest Income Recognized	2,026	2,700	1,993
Commercial and Industrial [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	10	3,661	183
Commercial Real Estate [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	42	196	204
Construction Loans [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	0	0
Small Business [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	1	8	4
Residential Real Estate [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	1,007	1,086	1,278
Home Equity [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	265	242	238
Consumer Portfolio Segment [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	17	21	23
With No Related Allowance Recorded [Member]
Impaired loans by loan portfolio
Recorded Investment	57,373	49,745	24,403
Unpaid Principal Balance	62,867	52,377	26,276
Average Recorded Investment	60,380	48,814	24,774
Interest Income Recognized	1,449	1,764	835
Related Allowance	0	0	0
With No Related Allowance Recorded [Member] | Commercial and Industrial [Member]
Impaired loans by loan portfolio
Recorded Investment	34,267	28,776	2,613
Unpaid Principal Balance	38,329	29,772	3,002
Average Recorded Investment	36,631	26,472	3,024
Interest Income Recognized	446	927	71
Related Allowance	0	0	0
With No Related Allowance Recorded [Member] | Commercial Real Estate [Member]
Impaired loans by loan portfolio
Recorded Investment	13,245	11,628	12,008
Unpaid Principal Balance	14,374	12,891	13,128
Average Recorded Investment	13,683	12,744	11,676
Interest Income Recognized	559	437	375
Related Allowance	0	0	0
With No Related Allowance Recorded [Member] | Construction Loans [Member]
Impaired loans by loan portfolio
Recorded Investment			304
Unpaid Principal Balance			305
Average Recorded Investment			308
Related Allowance			0
With No Related Allowance Recorded [Member] | Small Business [Member]
Impaired loans by loan portfolio
Recorded Investment	556	494	527
Unpaid Principal Balance	619	569	618
Average Recorded Investment	569	534	584
Interest Income Recognized	21	20	22
Related Allowance	0	0	0
With No Related Allowance Recorded [Member] | Residential Real Estate [Member]
Impaired loans by loan portfolio
Recorded Investment	4,264	4,216	3,874
Unpaid Principal Balance	4,397	4,427	4,033
Average Recorded Investment	4,332	4,302	3,958
Interest Income Recognized	218	185	157
Related Allowance	0	0	0
With No Related Allowance Recorded [Member] | Home Equity [Member]
Impaired loans by loan portfolio
Recorded Investment	4,950	4,485	4,893
Unpaid Principal Balance	5,056	4,572	5,005
Average Recorded Investment	5,063	4,602	5,023
Interest Income Recognized	198	184	195
Related Allowance	0	0	0
With No Related Allowance Recorded [Member] | Consumer Portfolio Segment [Member]
Impaired loans by loan portfolio
Recorded Investment	91	146	184
Unpaid Principal Balance	92	146	185
Average Recorded Investment	102	160	201
Interest Income Recognized	7	11	15
Related Allowance	0	0	0
With Allowance Recorded [Member]
Impaired loans by loan portfolio
Recorded Investment	15,428	27,552	27,007
Unpaid Principal Balance	16,409	28,694	28,546
Average Recorded Investment	15,800	28,395	26,904
Interest Income Recognized	577	936	1,158
With Allowance Recorded [Member] | Commercial and Industrial [Member]
Impaired loans by loan portfolio
Recorded Investment	376	10,402	2,534
Unpaid Principal Balance	376	10,440	2,648
Average Recorded Investment	391	10,760	2,848
Interest Income Recognized	19	325	48
With Allowance Recorded [Member] | Commercial Real Estate [Member]
Impaired loans by loan portfolio
Recorded Investment	3,393	5,185	10,978
Unpaid Principal Balance	3,399	5,533	11,047
Average Recorded Investment	3,447	5,491	10,789
Interest Income Recognized	198	200	592
With Allowance Recorded [Member] | Small Business [Member]
Impaired loans by loan portfolio
Recorded Investment	147	377	494
Unpaid Principal Balance	153	392	523
Average Recorded Investment	238	408	535
Interest Income Recognized	14	21	30
With Allowance Recorded [Member] | Residential Real Estate [Member]
Impaired loans by loan portfolio
Recorded Investment	9,420	9,959	11,531
Unpaid Principal Balance	10,154	10,530	12,652
Average Recorded Investment	9,575	10,065	11,669
Interest Income Recognized	284	332	460
With Allowance Recorded [Member] | Home Equity [Member]
Impaired loans by loan portfolio
Recorded Investment	1,876	1,378	1,096
Unpaid Principal Balance	2,110	1,547	1,287
Average Recorded Investment	1,916	1,403	655
Interest Income Recognized	55	50	14
With Allowance Recorded [Member] | Consumer Portfolio Segment [Member]
Impaired loans by loan portfolio
Recorded Investment	216	251	374
Unpaid Principal Balance	217	252	389
Average Recorded Investment	233	268	408
Interest Income Recognized	$ 7	$ 8	$ 14

Purchased Credit Impaired Loans

Purchased Credit Impaired Loans - Outstanding/Carrying Balance (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	$ 14,485	$ 20,477
Financing Receivable, Net	4,539,256	4,355,968
Receivables Acquired with Deteriorated Credit Quality [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Net	$ 13,023	$ 18,392	$ 20,595

LOANS, ALLOWANCE FOR LOAN LOS75

LOANS, ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans, Allowance for Loan Losses and Credit Quality [Abstract]
Unamortized Loan Commitment and Origination fees	$ 6,100,000	$ 5,100,000	$ 4,300,000
Unamortized Discounts or Premiums	$ 9,400,000	8,600,000	$ 6,600,000
Days To Be Termed As Non Accrual Loans	90 days
Significant advanced considered for risk rating change	$ 50,000
TDRs on nonaccrual status	$ 6,067,000	$ 5,199,000

LOANS, ALLOWANCE FOR LOAN LOS76

LOANS, ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY Activity in the Accretable Yield PCI Loans(Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Beginning balance	$ 2,370	$ 2,827
Accretion	(1,475)	(1,540)
Certainloansacquiredinatransfernotaccountedforasdebtsecuritiesaccretableyieldadjustmentchangesinexpectedcashflow	748	953
Reclassification from nonaccretable difference for loans with improved cash flows	148	130
Ending balance	$ 1,791	$ 2,370

LOANS, ALLOWANCE FOR LOAN LOS77

LOANS, ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY Foreclosed Residential Real Estate Property (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Foreclosed Residential Real Estate Property [Line Items]
Foreclosed residential real estate property held by the creditor	$ 612	$ 3,775
Mortgage Loans in Process of Foreclosure, Amount	$ 2,971	$ 1,715

BANK PREMISES AND EQUIPMENT (De

BANK PREMISES AND EQUIPMENT (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Total cost	$ 171,227,000	$ 146,762,000
Accumulated depreciation	(76,505,000)	(68,282,000)
Net bank premises and equipment	94,722,000	78,480,000
Depreciation expense	8,500,000	7,300,000	$ 7,000,000
Rental Income, Nonoperating	1,300,000
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease	939,000
Land [Member]
Property, Plant and Equipment [Line Items]
Total cost	23,719,000	20,585,000
Bank Premises [Member]
Property, Plant and Equipment [Line Items]
Total cost	$ 49,159,000	43,553,000
Bank Premises [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Bank Premises [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	40 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total cost	$ 25,184,000	24,387,000
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	1 year
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	27 years
Equipment Leased to Other Party [Member]
Property, Plant and Equipment [Line Items]
Total cost	$ 10,644,000
Equipment Leased to Other Party [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	7 years
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total cost	$ 62,521,000	$ 58,237,000
Furniture and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	1 year
Furniture and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	12 years

GOODWILL AND IDENTIFIABLE INT79

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 231,806	$ 221,526	$ 201,083
Other Intangible Assets	9,341	9,848
Total goodwill and other intangible assets	241,147	231,374
Core deposit intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Other Intangible Assets	8,636	8,527
Other identifiable Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Other Intangible Assets	$ 705	$ 1,321

GOODWILL AND IDENTIFIABLE INT80

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Details 1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Balance at beginning of year	$ 221,526	$ 201,083
Acquisitions	10,280	20,443
Balance at end of year	$ 231,806	$ 221,526

GOODWILL AND IDENTIFIABLE INT81

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Details 2) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 29,901	$ 26,937
Accumulated Amortization	(20,560)	(17,089)
Net Carrying Amount	9,341	9,848
Core deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	26,736	23,917
Accumulated Amortization	(18,100)	(15,390)
Net Carrying Amount	8,636	8,527
Other intangible assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,165	3,020
Accumulated Amortization	(2,460)	(1,699)
Net Carrying Amount	$ 705	$ 1,321

GOODWILL AND IDENTIFIABLE INT82

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Details 3) $ in Thousands	Dec. 31, 2017USD ($)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2,017	$ 2,394
2,018	1,687
2,019	1,414
2,020	1,245
2,021	$ 948

GOODWILL AND IDENTIFIABLE INT83

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 3.5	$ 2.8
Weighted average amortization period for intangible assets	9 years 9 months 18 days

DEPOSITS (Details)

DEPOSITS (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Banking and Thrift [Abstract]
Deposit Liabilities Reclassified as Loans Receivable	$ 2,300	$ 2,341
Deposit Liabilities, Collateral Issued, Financial Instruments	349,200	299,700
Time Deposits, Fiscal Year Maturity [Abstract]
1 year or less	393,452	430,834
Over 1 year to 2 years	119,341	82,627
Over 2 years to 3 years	57,619	44,190
Over 3 years to 4 years	41,183	49,446
Over 4 years to 5 years	32,706	42,055
Time Deposits	$ 644,301	$ 649,152
1 year or less (as percent)	61.10%	66.40%
Over 1 years to 2 years (as percent)	18.50%	12.70%
Over 2 years to 3 years (as percent)	8.90%	6.80%
Over 3 years to 4 years (as percent)	6.40%	7.60%
Over 4 years to 5 years (as percent)	5.10%	6.50%
Time Deposits (as percent)	100.00%	100.00%
Deposits over $250,000.00	$ 80,000	$ 75,300

BORROWINGS (FHLB Advances) (Det

BORROWINGS (FHLB Advances) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Federal Home Loan Bank, Advances, Maturities Summary, Due in Next Twelve Months	$ 52,475	$ 50,000
Federal Home Loan Bank, Advances, Activity for Year, Average Interest Rate for Year	1.58%	2.43%
Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Two		$ 0
Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, One to Two Years from Balance Sheet Date		0.00%
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	$ 52,475	$ 50,000
Federal Home Loan Bank, Advances, Weighted Average Interest Rate	1.58%	2.43%
Debt Instrument, Unamortized Premium	$ 789	$ 819
Total Federal Home Loan Bank Advances	$ 53,264	$ 50,819

BORROWINGS Repurchase Agreement

BORROWINGS Repurchase Agreements (Details) - Maturity Overnight [Member] - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Assets Sold under Agreements to Repurchase [Line Items]
Financial Assets Sold under Agreements to Repurchase, Gross Including Not Subject to Master Netting Arrangement	[1]	$ 162,679	$ 176,913
U.S. Government agency securities
Assets Sold under Agreements to Repurchase [Line Items]
Financial Assets Sold under Agreements to Repurchase, Gross Including Not Subject to Master Netting Arrangement		16,867	20,233
Agency mortgage-backed securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Financial Assets Sold under Agreements to Repurchase, Gross Including Not Subject to Master Netting Arrangement		51,273	79,079
Collateralized Mortgage Backed Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Financial Assets Sold under Agreements to Repurchase, Gross Including Not Subject to Master Netting Arrangement		$ 94,539	$ 77,601
[1]	All customer repurchase agreements have an overnight and continuous maturity date.

BORROWINGS (Long-Term Debt) (De

BORROWINGS (Long-Term Debt) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Total Long-Term Borrowings	$ 107,755	$ 107,742
Subordinated Debt	34,682	34,635
Junior Subordinated Debentures [Member] | Capital Trust V Preferred Securities Due in 2037 [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	51,503	51,500
Junior Subordinated Debentures [Member] | Slades Ferry Trust I Preferred Securities Due in 2034 [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	10,229	10,224
Junior Subordinated Debentures [Member] | Central Bancorp Capital Trust I Securities Due in 2034 [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	5,258	5,302
Junior Subordinated Debentures [Member] | Central Bancorp Capital Trust II Securities Due in 2037 [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	$ 6,083	$ 6,081

BORROWINGS (Trust Preferred Sec

BORROWINGS (Trust Preferred Securities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Junior Subordinated Debentures [Member]
Debt Instrument [Line Items]
Face Amount	$ 71	$ 71
Junior Subordinated Debentures [Member] | Capital Trust V Preferred Securities Due in 2037 [Member]
Debt Instrument [Line Items]
Face Amount	$ 50
Debt Instrument, interest rate, stated rate inclusive of interest rate swap - expired	2.84%	6.52%
Fixed rate	3.07%
Debt Instrument, interest rate, stated rate inclusive of interest rate swap - forward starting	2.84%
Junior Subordinated Debentures [Member] | Capital Trust V Preferred Securities Due in 2037 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.48%
Junior Subordinated Debentures [Member] | Slades Ferry Trust I Preferred Securities Due in 2034 [Member]
Debt Instrument [Line Items]
Face Amount	$ 10
Fixed rate	4.39%
Junior Subordinated Debentures [Member] | Slades Ferry Trust I Preferred Securities Due in 2034 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.79%
Junior Subordinated Debentures [Member] | Central Bancorp Capital Trust I Securities Due in 2034 [Member]
Debt Instrument [Line Items]
Face Amount	$ 5.1
Fixed rate	4.03%
Junior Subordinated Debentures [Member] | Central Bancorp Capital Trust I Securities Due in 2034 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.44%
Junior Subordinated Debentures [Member] | Central Bancorp Capital Trust II Securities Due in 2037 [Member]
Debt Instrument [Line Items]
Face Amount	$ 5.9
Fixed rate	7.015%
Junior Subordinated Debentures [Member] | Central Bancorp Capital Trust II Securities Due in 2037 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.65%
Fixed rate	3.24%
Subordinated Debt [Member] | Subordinated Debentures Due in November 2019 [Member] [Domain]
Debt Instrument [Line Items]
Fixed rate	4.75%
Subordinated Debt [Member] | Subordinated Debentures Due in November 2019 [Member] [Domain] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.98%

BORROWINGS (Maturities of Long-

BORROWINGS (Maturities of Long-Term Debt) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Long-term Debt, Fiscal Year Maturity [Abstract]
2,015	$ 0
2,016	0
2,017	0
2,018	0
2,019	0
Thereafter	108,198
Total	108,198
Junior Subordinated Debentures [Member] | Capital Trust V Preferred Securities Due in 2037 [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
2,015	0
2,016	0
2,017	0
2,018	0
2,019	0
Thereafter	51,547
Total	51,547
Junior Subordinated Debentures [Member] | Slades Ferry Trust I Preferred Securities Due in 2034 [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
2,015	0
2,016	0
2,017	0
2,018	0
2,019	0
Thereafter	10,310
Total	10,310
Junior Subordinated Debentures [Member] | Central Bancorp Capital Trust I Securities Due in 2034 [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
2,015	0
2,016	0
2,017	0
2,018	0
2,019	0
Thereafter	5,258
Total	5,258
Junior Subordinated Debentures [Member] | Central Bancorp Capital Trust II Securities Due in 2037 [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
2,015	0
2,016	0
2,017	0
2,018	0
2,019	0
Thereafter	6,083
Total	6,083
Subordinated Debentures [Member] | Subordinated Debentures Due August 27, 2018 [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
2,015	0
2,016	0
2,017	0
2,018	0
2,019	0
Thereafter	35,000
Total	$ 35,000

BORROWINGS (Details Textual)

BORROWINGS (Details Textual) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Subordinated Debt	$ 34,682,000				$ 34,635,000				$ 34,682,000	$ 34,635,000
Interest Expense, Long-term Debt									4,000,000	5,800,000	$ 6,600,000
Gains (Losses) on Extinguishment of Debt	0	$ 0	$ 0	$ 0	0	$ 0	$ 0	$ (437,000)	0	(437,000)	(122,000)
Loans Pledged as Collateral	$ 1,500,000,000				$ 1,400,000,000				$ 1,500,000,000	$ 1,400,000,000
Federal Home Loan Bank Advances Weighted Average Interest Rate inclusive of Swaps	2.47%				3.42%				2.47%	3.42%
Repayments of Debt										$ 49,000,000	13,000,000
Securities Sold under Agreements to Repurchase	$ 162,679,000				$ 176,913,000				$ 162,679,000	176,913,000
Interest expense on short-term borrowings									257,000	208,000	$ 210,000
Total Long-Term Borrowings	107,755,000				107,742,000				107,755,000	107,742,000
Parent Company [Member]
Debt Instrument [Line Items]
Subordinated Debt	35,000,000				35,000,000				35,000,000	35,000,000
Capital Trust V Preferred Securities Due in 2037 [Member] | Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	$ 51,503,000				$ 51,500,000				$ 51,503,000	$ 51,500,000
Fixed rate	3.07%								3.07%
Debt Instrument, interest rate, stated rate inclusive of interest rate swap - expired	2.84%				6.52%				2.84%	6.52%
Debt Instrument, interest rate, stated rate inclusive of interest rate swap - forward starting	2.84%								2.84%
Capital Trust V Preferred Securities Due in 2037 [Member] | Junior Subordinated Debt [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate									1.48%
Subordinated Debentures Due in November 2019 [Member] [Domain] | Subordinated Debentures [Member]
Debt Instrument [Line Items]
Fixed rate	4.75%								4.75%
Subordinated Debentures Due in November 2019 [Member] [Domain] | Subordinated Debentures [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate									2.98%
Slades Ferry Trust I Preferred Securities Due in 2034 [Member] | Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	$ 10,229,000				$ 10,224,000				$ 10,229,000	$ 10,224,000
Fixed rate	4.39%								4.39%
Slades Ferry Trust I Preferred Securities Due in 2034 [Member] | Junior Subordinated Debt [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate									2.79%
Central Bancorp Capital Trust I Securities Due in 2034 [Member] | Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	$ 5,258,000				5,302,000				$ 5,258,000	5,302,000
Fixed rate	4.03%								4.03%
Central Bancorp Capital Trust I Securities Due in 2034 [Member] | Junior Subordinated Debt [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on variable rate									2.44%
Central Bancorp Capital Trust II Securities Due in 2037 [Member] | Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	$ 6,083,000				6,081,000				$ 6,083,000	6,081,000
Fixed rate	7.015%								7.015%
Central Bancorp Capital Trust II Securities Due in 2037 [Member] | Junior Subordinated Debt [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Fixed rate	3.24%								3.24%
Basis spread on variable rate									1.65%
Federal Home Loan Bank Advances [Member]
Debt Instrument [Line Items]
Federal home loan bank unused remaining available borrowing capacity	$ 954,800,000				$ 793,100,000				$ 954,800,000	$ 793,100,000
Line of credit maximum borrowing capacity	$ 5,000,000								$ 5,000,000

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income	$ 22,064	$ 23,852	$ 20,563	$ 20,725	$ 17,179	$ 20,484	$ 20,374	$ 18,611	$ 87,204	$ 76,648	$ 64,960
Weighted Average Shares (in shares)
Basic Shares (in shares)	27,445,739	27,436,792	27,257,799	27,029,640	26,710,029	26,324,316	26,304,129	26,275,323	27,294,028	26,404,071	25,891,382
Effect of dilutive securities (in shares)	77,615	76,307	74,497	81,283	60,022	53,072	47,885	43,409	78,076	51,847	68,566
Weighted average common shares (diluted) (in shares)	27,523,354	27,513,099	27,332,296	27,110,923	26,770,051	26,377,388	26,352,014	26,318,732	27,372,104	26,455,918	25,959,948
Net Income Available to Common Shareholders per Share (in dollars per share)
Basic EPS (in dollars per share)	$ 0.80	$ 0.87	$ 0.75	$ 0.77	$ 0.64	$ 0.78	$ 0.77	$ 0.71	$ 3.19	$ 2.90	$ 2.51
Effect of Dilutive Securities (in dollars per share)									0	0	(0.01)
Diluted EPS (in dollars per share)	$ 0.80	$ 0.87	$ 0.75	$ 0.76	$ 0.64	$ 0.78	$ 0.77	$ 0.71	$ 3.19	$ 2.90	$ 2.50

EARNINGS PER SHARE (Details 1)

EARNINGS PER SHARE (Details 1) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Performance Shares [Member]
Details of anti dilutive options to purchase common stock
Stock options	0	0	0
Stock options [Member]
Details of anti dilutive options to purchase common stock
Stock options	103	0	0

CUMULATIVELY GRANTED AWARDS (De

CUMULATIVELY GRANTED AWARDS (Details)	Dec. 31, 2017shares
2005 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized Stock Awards	1,650,000
Cumulative Granted, Net of Forfeitures	1,233,487
Authorized but Unissued	416,513
2005 Plan [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cumulative Granted, Net of Forfeitures	537,941
2005 Plan [Member] | Restricted stock awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cumulative Granted, Net of Forfeitures	695,546
2010 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized Stock Awards	314,600
Cumulative Granted, Net of Forfeitures	135,245
Authorized but Unissued	179,355
2010 Plan [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cumulative Granted, Net of Forfeitures	42,000
2010 Plan [Member] | Restricted stock awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cumulative Granted, Net of Forfeitures	93,245

PRE TAX EXPENSE (Details 1)

PRE TAX EXPENSE (Details 1) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock based award expense		$ 3,333	$ 2,965	$ 2,490
Related tax benefits recognized in earnings		1,362	1,211	1,122
Stock options [Member] | Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock based award expense		76	72	0
Restricted stock awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock based award expense	[1]	2,730	2,590	2,296
Restricted stock awards [Member] | Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock based award expense		$ 527	$ 303	$ 194
[1]	Inclusive of compensation expense associated with time-vested and performance-based restricted stock awards.

STOCK OPTION AWARDS DURING PERI

STOCK OPTION AWARDS DURING PERIOD (Details 3) - Stock options [Member] - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining recognition period (years)	1 year
Shares granted	5,000
Weighted average grant date fair value of options granted (per share)	$ 12.43	$ 11.03	$ 0
2/20/2016 | 2010 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted		5,000
Vesting period		22 months
Investment Options, Expiration Date		Feb. 20, 2026
Expected volatility		32.44%
Expected life (years)		5 years 6 months
Expected dividend yield		2.28%
Risk free interest rate		1.29%
Weighted average grant date fair value of options granted (per share)		$ 10.59
Options Granted Date Three [Member] | 2010 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	5,000
Vesting period	14 months
Investment Options, Expiration Date	Nov. 7, 2027
Expected volatility	20.80%
Expected life (years)	5 years 6 months
Expected dividend yield	1.87%
Risk free interest rate	2.02%
Weighted average grant date fair value of options granted (per share)	$ 12.43
Options Granted Date Two [Member] | 2010 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted		5,000
Vesting period		18 months
Investment Options, Expiration Date		Jul. 14, 2026
Expected volatility		32.28%
Expected life (years)		5 years 6 months
Expected dividend yield		2.37%
Risk free interest rate		1.14%
Weighted average grant date fair value of options granted (per share)		$ 11.46

RELEVANT STOCK OPTION INFORMATI

RELEVANT STOCK OPTION INFORMATION (Details 4) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash received from stock option exercises	$ 214	$ 201	$ 1,367
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of stock options vested based on grant date fair value	72	37	14
Intrinsic value of stock options exercised	1,082	494	3,362
Cash received from stock option exercises	918	680	6,105
Employee Service Share-based Compensation, Tax Benefit from Exercise of Stock Options	$ 442	$ 204	$ 1,362
Weighted average grant date fair value of options granted (per share)	$ 12.43	$ 11.03	$ 0

STOCK OPTION ROLLFORWARD (Detai

STOCK OPTION ROLLFORWARD (Details 5) - Stock options [Member] - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Stock Option Awards, Outstanding (in shares):
Balance outstanding at beginning of period		109,650
Granted		5,000
Exercised		(30,150)
Forfeited		0
Expired		(500)
Balance outstanding at end of period		84,000	[1]	109,650
Options outstanding and expected to vest at December 31, 2017	[2]	84,000
Options exercisable at December 31, 2017	[3]	79,001
Weighted Average Exercise Price, Outstanding (in usd per share):
Balance outstanding at beginning of period		$ 29.93
Granted		70.28
Exercised		30.43
Forfeited		0
Expired		28.88
Balance outstanding at end of period		32.16		$ 29.93
Options outstanding and expected to vest at December 31, 2017		32.16
Options exercisable at December 31, 2017		$ 30.21
Balance at December 31, 2016, Weighted average remaining contractual term (years)		3 years 16 days
Options outstanding and expected to vest at December 31, 2016, Weighted Average Remaining Contractual Term (years)		3 years 16 days
Options exercisable at December 31, 2016, Weighted Average Remaining Contractual Term (years)		2 years 7 months 20 days
Balance at December 31, 2016, Aggregate Intrinsic Value	[4]	$ 3,258
Options outstanding and expected to vest at December 31, 2016, Aggregate Intrinsic Value	[4]	3,258
Options exercisable at December 31, 2016, Aggregate Intrinsic Value	[4]	$ 3,218
Stock Option Awards, Nonvested (in shares)
Balance nonvested at beginning of period		6,666
Granted		5,000
Vested		(6,667)
Forfeited		0
Expired		0
Balance nonvested at end of period		4,999		6,666
Weighted Average Grant Date Fair Value, Nonvested (in dollars per share):
Balance nonvested at beginning of period		$ 11.03
Granted		12.43		$ 11.03	$ 0
Vested		10.85
Forfeited		0
Expired		0
Balance nonvested at end of period		$ 12.11		$ 11.03
Unrecognized compensation cost		$ 22
Weighted average remaining recognition period (years)		1 year
[1]	Inclusive of 38,000 stock options outstanding to Directors.
[2]	Inclusive of 38,000 vested stock options and expected to vest to Directors.
[3]	Inclusive of 33,001 vested stock options outstanding to Directors.
[4]	The aggregate intrinsic value in the preceding tables represents the total pre-tax intrinsic value, based on the average of the high price and low price at which the Company’s common stock traded on December 31, 2017 of $70.95, which would have been received by the option holders had they all exercised their options as of that date.

RSA GRANTS (Details 6)

RSA GRANTS (Details 6) - $ / shares		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted stock awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value		$ 63.07
Restricted stock awards [Member] | Employee Stock Plan [Member] | Date Sixteen [Member] | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted		1,200
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]	$ 62.53
Vesting terms		Ratably over 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | Date Seventeen [Member] | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted		34,150
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]	$ 63.10
Vesting terms		Ratably over 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | Date eighteen [Member] | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted		500
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]	$ 65.63
Vesting terms		Ratably over 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | Date nineteen [Member] | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted		1,500
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]	$ 64.14
Vesting terms	[2]	Once on November 30, 2017 (2)
Restricted stock awards [Member] | Employee Stock Plan [Member] | Date Twenty [Member] | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted		1,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]	$ 64.03
Vesting terms		Ratably over 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | Date Twenty Two [Member] | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted		950
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]	$ 66.18
Vesting terms		Ratably over 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | 2/11/2016 | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted			51,475
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]		$ 41.96
Vesting terms			Ratably over 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | 3/1/2016 | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted			600
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]		$ 44.37
Vesting terms			Ratably over 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | 9/19/2016 | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted			800
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]		$ 52.92
Vesting terms			Ratably over 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | 11/7/2016 | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted			500
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]		$ 54.28
Vesting terms			Ratably over 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | 2/11/2015 | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted				31,500
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]			$ 39.42
Vesting terms				Ratably over 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | 2/12/2015 | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted				25,910
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]			$ 40.03
Vesting terms				Ratably over 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | 3/19/2015 | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted				3,800
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]			$ 43.56
Vesting terms				Ratably over 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | 4/27/2015 | At The End of Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted				625
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]			$ 41.61
Vesting terms				At the end of 3 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | 4/27/2015 | At The End of Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted				1,875
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]			$ 41.61
Vesting terms				At the end of 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | 10/13/2015 | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted				1,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]			$ 46.09
Vesting terms				Ratably over 5 years from grant date
Restricted stock awards [Member] | Employee Stock Plan [Member] | 10/20/2015 | Ratably Over Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted				2,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]			$ 46.47
Vesting terms				Ratably over 5 years from grant date
Restricted stock awards [Member] | Non Employee Director Stock Plan Member | Date Twenty One [Member] | At The End of Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted		7,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]	$ 61.95
Vesting terms	[3]	At the end of 5 years from grant date (3)
Restricted stock awards [Member] | Non Employee Director Stock Plan Member | 5/24/2016 | At The End of Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted			8,700
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]		$ 48.34
Vesting terms	[3]		At the end of 5 years from grant date (3)
Restricted stock awards [Member] | Non Employee Director Stock Plan Member | 11/14/2016 | At The End of Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted			725
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]		$ 63.43
Vesting terms	[4]		Once on May 24, 2021 (4)
Restricted stock awards [Member] | Non Employee Director Stock Plan Member | 5/27/2015 | At The End of Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted				8,800
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]			$ 45.02
Vesting terms	[3]			At the end of 5 years from grant date (3)
Restricted stock awards [Member] | Non Employee Director Stock Plan Member | 7/14/2015 | At The End of Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted				800
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]			$ 47.82
Vesting terms	[5]			Once on May 27, 2020 (5)
Performance Shares [Member] | Employee Stock Plan [Member] | 2/11/2016 | At The End of Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted			20,450
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]		$ 41.96
Vesting terms			The earlier of: the date on which it is determined if the performance goal has been achieved; or, March 31, 2019.
Performance Shares [Member] | Employee Stock Plan [Member] | 2/12/2015 | At The End of Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted				21,780
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]			$ 40.03
Vesting terms				The earlier of: the date on which it is determined if the performance goal has been achieved; or, March 31, 2018.
Performance Shares [Member] | Employee Stock Plan [Member] | Date Twenty Three [Member] | At The End of Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted		14,400
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]	$ 63.10
Vesting terms		The earlier of: the date on which it is determined if the performance goal has been achieved; or, March 31, 2020.
[1]	The fair value of the restricted stock awards are based upon the average of the high and low prices at which the Company’s common stock traded on the date of grant. The holders of time-vested restricted stock awards participate fully in the rewards of stock ownership of the Company, including voting and dividend rights. The holders of performance-based restricted stock awards do not participate in the rewards of stock ownership of the Company until vested. The holders of all restricted stock awards are not required to pay any consideration to the Company for the awards.
[2]	This restricted stock grant fully vested upon an employee's termination, on November 30, 2017.
[3]	These restricted stock grants will vest at the end of a five year period, or earlier if the director ceases to be a director for any reason other than cause, such as, for example, by retirement.
[4]	These restricted stock grants will vest on May 24, 2021, or earlier if the director ceases to be a director for any reason other than cause, such as, for example, by retirement.
[5]	These restricted stock grants will vest on May 27, 2020, or earlier if the director ceases to be a director for any reason other than cause, such as, for example, by retirement.

FV OF RSA VESTS (Details 7)

FV OF RSA VESTS (Details 7) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted stock awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of restricted stock awards upon vesting	$ 5,717	$ 3,019	$ 2,610

RSA ROLLFORWARD (Details 8)

RSA ROLLFORWARD (Details 8) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares
Oustanding (in shares):
Beginning balance	212,698
Ending balance	177,191
Restricted stock awards [Member]
Oustanding (in shares):
Beginning balance	264,315
Granted	60,700
Vested/Released	(89,436)
Forfeited	(9,614)
Ending balance	225,965	[1]
Weighted Average Grant Price (in usd per share):
Beginning balance | $ / shares	$ 38.88
Granted | $ / shares	63.07
Vested/Released | $ / shares	36.79
Forfeited | $ / shares	39.49
Ending balance | $ / shares	$ 46.18
Unrecognized compensation cost (inclusive of directors’ fees) | $	$ 6,355
Weighted average remaining recognition period (years)	3 years
[1]	Inclusive of 38,445 restricted stock awards outstanding to Directors.

STOCK BASED COMPENSATION (Detai

STOCK BASED COMPENSATION (Details Textual) - $ / shares		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number		177,191		212,698
Share Based Compensation Arrangement By Share Based Payment Award Options Price Per Share Common Stock Average High And Low Price Intrinsic Value		$ 70.95
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number		84,000	[1]	109,650
Options outstanding and expected to vest at December 31, 2017	[2]	84,000
Annualized estimated forfeitures				4.50%	4.50%
Options exercisable at December 31, 2017	[3]	79,001
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares		4,999		6,666
Weighted average remaining recognition period (years)		1 year
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number		225,965	[4]	264,315
Weighted average remaining recognition period (years)		3 years
Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number		38,000
Options outstanding and expected to vest at December 31, 2017	[1]	38,000
Options exercisable at December 31, 2017	[1]	33,001
Director [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number		38,445
Two Thousand Five Amended and Restated Employee Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		1,650,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		416,513
Two Thousand Ten Nonemployee Director Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		314,600
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		179,355
Two Thousand Ten Nonemployee Director Stock Plan [Member] | Maximum [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		5 years
[1]	Inclusive of 38,000 stock options outstanding to Directors.
[2]	Inclusive of 38,000 vested stock options and expected to vest to Directors.
[3]	Inclusive of 33,001 vested stock options outstanding to Directors.
[4]	Inclusive of 38,445 restricted stock awards outstanding to Directors.

Derivatives and Hedging Acti102

Derivatives and Hedging Activities (Derivative Positions for Interest Rate Swaps which Qualify as Hedges) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Notional Amount	$ 100,000,000	$ 75,000,000
Fair Value	1,616,000	624,000
Amortization Of Deferred Hedge Gains Losses	244,000	244,000	$ 244,000
Notional amount of fair value hedged derivative	0	0	$ 0
Positions Seven [Member] [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Notional Amount	$ 25,000,000
Trade Date	Jul. 18, 2017
Effective Date	Aug. 15, 2017
Maturity Date	Aug. 15, 2022
Receive (Variable) Index	3 Month LIBOR
Current Rate Received	1.42%
Pay Fixed Swap Rate	1.88%
Fair Value	$ 345,000
Positions Five [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Notional Amount	$ 25,000,000
Trade Date	Apr. 1, 2016
Effective Date	Jan. 17, 2017
Maturity Date	Dec. 15, 2021
Receive (Variable) Index	3 Month LIBOR
Current Rate Received	1.59%
Pay Fixed Swap Rate	1.36%
Fair Value	$ 772,000
Positions One [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Notional Amount		$ 25,000,000
Trade Date		Dec. 9, 2008
Effective Date		Dec. 10, 2008
Maturity Date		Dec. 10, 2018
Receive (Variable) Index		3 Month LIBOR
Current Rate Received		0.95%
Pay Fixed Swap Rate		2.94%
Fair Value		$ (740,000)
Positions Six [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Notional Amount	$ 25,000,000
Trade Date	Apr. 1, 2016
Effective Date	Jan. 17, 2017
Maturity Date	Dec. 15, 2021
Receive (Variable) Index	3 Month LIBOR
Current Rate Received	1.59%
Pay Fixed Swap Rate	1.36%
Fair Value	$ 763,000
Positions Two [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Notional Amount		$ 25,000,000
Trade Date		Apr. 1, 2016
Effective Date		Jan. 17, 2017
Maturity Date		Dec. 15, 2021
Receive (Variable) Index		3 Month LIBOR
Pay Fixed Swap Rate		1.36%
Fair Value		$ 689,000
Positions Three [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Notional Amount		$ 25,000,000
Trade Date		Apr. 1, 2016
Effective Date		Jan. 17, 2017
Maturity Date		Dec. 15, 2021
Receive (Variable) Index		3 Month LIBOR
Pay Fixed Swap Rate		1.36%
Fair Value		$ 675,000
Positions Four [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Notional Amount	$ 25,000,000
Trade Date	Dec. 9, 2008
Effective Date	Dec. 10, 2008
Maturity Date	Dec. 10, 2018
Receive (Variable) Index	3 Month LIBOR
Current Rate Received	1.54%
Pay Fixed Swap Rate	2.94%
Fair Value	$ (264,000)

Derivatives and Hedging Acti103

Derivatives and Hedging Activities (Customer Related Derivative Positions - Not Designated as Hedges) (Details) $ in Thousands		Dec. 31, 2017USD ($)position	Dec. 31, 2016USD ($)position
Summary of customer related derivative positions, not designated as hedging
Total		$ 100,000	$ 75,000
Fair Value		$ 1,616	$ 624
Not Designated as Hedging Instrument [Member] | Receive fixed, pay variable | Loan level swaps
Summary of customer related derivative positions, not designated as hedging
Number of Positions (1) | position	[1]	246	222
Less than 1 year		$ 36,023	$ 30,245
Less than 2 years		61,500	21,708
Less than 3 years		152,287	63,771
Less than 4 years		111,147	165,783
Thereafter		591,385	567,897
Total		952,342	849,404
Fair Value		$ 3,875	$ 12,005
Not Designated as Hedging Instrument [Member] | Pay fixed, receive variable | Loan level swaps
Summary of customer related derivative positions, not designated as hedging
Number of Positions (1) | position	[1]	231	207
Less than 1 year		$ 36,023	$ 30,245
Less than 2 years		61,500	21,708
Less than 3 years		152,287	63,771
Less than 4 years		111,147	165,783
Thereafter		591,385	567,897
Total		952,342	849,404
Fair Value		$ (3,880)	$ (12,008)
Not Designated as Hedging Instrument [Member] | Buys foreign currency, sells U.S. currency | Foreign exchange contracts
Summary of customer related derivative positions, not designated as hedging
Number of Positions (1) | position	[1]	15	33
Less than 1 year		$ 26,382	$ 45,711
Less than 2 years		3,780
Total		30,162	45,711
Fair Value		$ 1,202	$ (2,250)
Not Designated as Hedging Instrument [Member] | Buys U.S. currency, sells foreign currency | Foreign exchange contracts
Summary of customer related derivative positions, not designated as hedging
Number of Positions (1) | position	[1]	15	33
Less than 1 year		$ 26,382	$ 45,711
Less than 2 years		3,780
Total		30,162	45,711
Fair Value		$ (1,188)	$ 2,277
[1]	The Company may enter into one dealer swap agreement which offsets multiple commercial borrower swap agreements.

Derivatives and Hedging Acti104

Derivatives and Hedging Activities (FV of Derivative Financial Instruments and Classification on Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair value of derivative financial instruments as well as their classification on the balance sheet
Total	$ 17,318	$ 22,331
Total	15,693	21,683
Other Assets [Member]
Fair value of derivative financial instruments as well as their classification on the balance sheet
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	15,596	21,397
Total	17,476	22,761
Other Liabilities [Member]
Fair value of derivative financial instruments as well as their classification on the balance sheet
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	15,429	21,176
Total	15,693	21,916
Interest rate derivatives
Fair value of derivative financial instruments as well as their classification on the balance sheet
Total		740
Interest rate derivatives | Derivatives designated as hedges: [Member] | Other Assets [Member]
Fair value of derivative financial instruments as well as their classification on the balance sheet
Interest Rate Derivative Assets, at Fair Value	1,880	1,364
Interest rate derivatives | Derivatives designated as hedges: [Member] | Other Liabilities [Member]
Fair value of derivative financial instruments as well as their classification on the balance sheet
Interest rate derivatives	264	740
Loan level swaps
Fair value of derivative financial instruments as well as their classification on the balance sheet
Total		18,629
Total		18,632
Loan level swaps | Other Assets [Member]
Fair value of derivative financial instruments as well as their classification on the balance sheet
Total	14,236	18,629
Loan level swaps | Other Liabilities [Member]
Fair value of derivative financial instruments as well as their classification on the balance sheet
Total	14,241	18,632
Foreign exchange contracts
Fair value of derivative financial instruments as well as their classification on the balance sheet
Total		2,338
Total		2,311
Foreign exchange contracts | Other Assets [Member]
Fair value of derivative financial instruments as well as their classification on the balance sheet
Total	1,202	2,338
Foreign exchange contracts | Other Liabilities [Member]
Fair value of derivative financial instruments as well as their classification on the balance sheet
Total	1,188	2,311
Mortgage Derivatives | Derivatives not designated as hedges: [Member] | Other Assets [Member]
Fair value of derivative financial instruments as well as their classification on the balance sheet
Interest rate lock commitments	149	430
Forward sales agreements	9	0
Mortgage Derivatives | Derivatives not designated as hedges: [Member] | Other Liabilities [Member]
Fair value of derivative financial instruments as well as their classification on the balance sheet
Interest rate lock commitments	0	0
Forward sales agreements	$ 0	$ 233

Derivatives and Hedging Acti105

Derivatives and Hedging Activities (Derivative Financial Instruments included in OCI and Current Earnings) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent		$ 443	$ 2,170	$ 1,199
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Borrowings Expense, before Tax	[1]	(441)	(2,520)	(2,828)
Derivatives designated as hedges: [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net			(2,520)	(2,828)
Derivatives not designated as hedges: [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other income		(54)	(44)	(43)
Other Expense [Member] | Derivatives not designated as hedges: [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other income		(21)	(82)	(53)
Other Income [Member] | Derivatives not designated as hedges: [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other income		6	73	60
Mortgage banking income | Derivatives not designated as hedges: [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Increase Decrease In Fair Value Of Unhedged Derivative Instruments Relating To Residential Loans		(39)	(35)	(50)
Derivatives designated as hedges: [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent		$ 443	$ 2,170	$ 1,199
[1]	Includes the amortization of the remaining balance of a realized but unrecognized gain, net of tax, from the termination of interest rate swaps in 2009. The original gain of $1.4 million, net of tax, will be recognized in earnings through December 2018, the original maturity date of the swap. The balance of this gain had amortized to $137,000, $281,000, and $427,000 at December 31, 2017, 2016, and 2015, respectively.

Derivatives and Hedging Acti106

Derivatives and Hedging Activities (Textual) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivative, Net Liability Position, Aggregate Fair Value	$ 4,200,000	$ 12,800,000
Total	100,000,000	75,000,000
Increase (Decrease) in Loans Held-for-sale	(113,000)	87,000	$ (22,000)
Net amortization income	244,000	244,000	244,000
Exposure to Institutional Counterparties	$ 7,100,000	4,700,000
Maximum length of time Company is currently hedging its exposure	5 years
Interest expense	$ 202,000
Customer related positions	9,500,000	16,100,000
Gain (Loss) on Sales of Loans, Net	4,700,000	6,100,000	4,700,000
Notional amount of fair value hedged derivative	0	0	$ 0
Positions Three [Member]
Derivative [Line Items]
Total		$ 25,000,000
Positions Six [Member]
Derivative [Line Items]
Total	$ 25,000,000

BALANCE SHEET OFFSETTING (Detai

BALANCE SHEET OFFSETTING (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Offsetting Liabilities [Line Items]
Total		$ 17,318	$ 22,331
Derivative Asset, Collateral, Obligation to Return Cash, Offset		0	0
Derivative Asset		17,318	22,331
Derivative, Collateral, Obligation to Return Securities	[1]	5,383	4,222
Derivative, Collateral, Obligation to Return Cash		0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral		11,935	18,109
Total		15,693	21,683
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		0	0
Derivative Liability		15,693	21,683
Derivative, Collateral, Right to Reclaim Securities	[1]	5,383	4,222
Derivative, Collateral, Right to Reclaim Cash		3,939	11,846
Derivative Liability, Fair Value, Amount Offset Against Collateral		6,371	5,615
Interest Rate Swap [Member]
Offsetting Liabilities [Line Items]
Derivative Asset, Collateral, Obligation to Return Cash, Offset		0	0
Derivative Asset		1,880	1,364
Derivative, Collateral, Obligation to Return Securities	[1]	805	961
Derivative, Collateral, Obligation to Return Cash		0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral		1,075	403
Total			740
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		0	0
Derivative Liability		264	740
Derivative, Collateral, Right to Reclaim Securities	[1]	0	0
Derivative, Collateral, Right to Reclaim Cash		264	740
Derivative Liability, Fair Value, Amount Offset Against Collateral		0	0
Loan level swaps
Offsetting Liabilities [Line Items]
Total			18,629
Derivative Asset, Collateral, Obligation to Return Cash, Offset		0	0
Derivative Asset		14,236	18,629
Derivative, Collateral, Obligation to Return Securities	[1]	4,578	3,261
Derivative, Collateral, Obligation to Return Cash		0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral		9,658	15,368
Total			18,632
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		0	0
Derivative Liability		14,241	18,632
Derivative, Collateral, Right to Reclaim Securities	[1]	5,383	4,222
Derivative, Collateral, Right to Reclaim Cash		3,675	11,106
Derivative Liability, Fair Value, Amount Offset Against Collateral		5,183	3,304
Foreign Exchange Contract [Member]
Offsetting Liabilities [Line Items]
Total			2,338
Derivative Asset, Collateral, Obligation to Return Cash, Offset		0	0
Derivative Asset		1,202	2,338
Derivative, Collateral, Obligation to Return Securities	[1]	0	0
Derivative, Collateral, Obligation to Return Cash		0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral		1,202	2,338
Total			2,311
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		0	0
Derivative Liability		1,188	2,311
Derivative, Collateral, Right to Reclaim Securities	[1]	0	0
Derivative, Collateral, Right to Reclaim Cash		0	0
Derivative Liability, Fair Value, Amount Offset Against Collateral		1,188	2,311
Other Assets [Member]
Offsetting Liabilities [Line Items]
Total		17,476	22,761
Other Assets [Member] | Loan level swaps
Offsetting Liabilities [Line Items]
Total		14,236	18,629
Other Assets [Member] | Foreign Exchange Contract [Member]
Offsetting Liabilities [Line Items]
Total		1,202	2,338
Other Assets [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Offsetting Liabilities [Line Items]
Interest Rate Derivative Assets, at Fair Value		1,880	1,364
Other Liabilities [Member]
Offsetting Liabilities [Line Items]
Total		15,693	21,916
Other Liabilities [Member] | Loan level swaps
Offsetting Liabilities [Line Items]
Total		14,241	18,632
Other Liabilities [Member] | Foreign Exchange Contract [Member]
Offsetting Liabilities [Line Items]
Total		1,188	2,311
Other Liabilities [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Offsetting Liabilities [Line Items]
Interest rate derivatives		264	740
Customer Repurchase Agreements [Member]
Offsetting Liabilities [Line Items]
Securities Sold under Agreements to Repurchase, Gross Including Not Subject to Master Netting Arrangement		162,679	176,913
Securities Sold under Agreements to Repurchase, Asset		0	0
Securities Sold under Agreements to Repurchase		162,679	176,913
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	[1]	0	0
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Cash		0	0
Securities Sold under Agreements to Repurchase, Fair Value of Collateral		$ 162,679	$ 176,913
[1]	Reflects offsetting derivative positions with the same counterparty.

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current expense
Federal									$ 28,852	$ 26,549	$ 11,946
State									9,278	8,883	5,052
Total current expense									38,130	35,432	16,998
Deferred expense (benefit)
Federal									7,953	153	8,466
State									1,258	(158)	1,754
Total deferred expense (benefit)									9,211	(5)	10,220
Total expense	$ 14,915	$ 12,681	$ 10,731	$ 9,014	$ 7,698	$ 9,793	$ 9,508	$ 8,428	$ 47,341	$ 35,427	$ 27,218

INCOME TAXES (Details 1)

INCOME TAXES (Details 1) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Computed statutory federal income tax provision									$ 47,091	$ 39,226	$ 32,262
State taxes, net of federal tax benefit									6,817	5,643	4,500
Revaluation of net deferred tax assets									1,895	0	0
Merger and other related costs (non-deductible)									213	210	185
Change in valuation allowance									31	28	41
New Markets Tax Credits									(3,960)	(6,360)	(6,514)
Increase in cash surrender value of life insurance									(1,445)	(1,431)	(1,292)
Stock-based compensation									(1,258)	0	0
Low Income Housing Project Investments									(1,253)	(1,641)	(1,182)
Nontaxable interest, net									(987)	(996)	(973)
Other, net									197	748	191
Total expense	$ 14,915	$ 12,681	$ 10,731	$ 9,014	$ 7,698	$ 9,793	$ 9,508	$ 8,428	$ 47,341	$ 35,427	$ 27,218
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Computed statutory federal income tax provision									35.00%	35.00%	35.00%
State taxes, net of federal tax benefit									5.07%	5.03%	4.88%
Revaluation of net deferred tax assets									1.41%	0.00%	0.00%
Merger and other related costs (non-deductible)									0.16%	0.19%	0.20%
Change in valuation allowance									0.02%	0.02%	0.04%
New Markets Tax Credits									(2.94%)	(5.67%)	(7.07%)
Increase in cash surrender value of life insurance									(1.07%)	(1.28%)	(1.40%)
Stock-based compensation									(0.94%)	(0.00%)	(0.00%)
Low Income Housing Project Investments									(0.93%)	(1.46%)	(1.28%)
Nontaxable interest, net									(0.73%)	(0.89%)	(1.06%)
Other, net									0.15%	0.67%	0.22%
Total expense									35.20%	31.61%	29.53%

INCOME TAXES (Details 2)

INCOME TAXES (Details 2) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets
Accrued expenses not deducted for tax purposes	$ 9,268	$ 15,401
Allowance for loan losses	16,702	24,681
Deferred gain on sale leaseback transaction	909	1,744
Employee and director equity compensation	1,559	2,095
Federal Home Loan Bank borrowings fair value adjustment	26	82
Loan basis difference fair value adjustment	3,070	4,336
Deferred Tax Assets, Operating Loss Carryforwards	127	69
Deferred Tax Assets, Unrealized Losses on Available-for-Sale Securities, Gross	106	0
Other	527	1,015
Gross deferred tax assets	32,294	49,423
Deferred Tax Assets, Valuation Allowance	(121)	(69)
Deferred Tax Assets, Net of Valuation Allowance	32,173	49,354
Deferred tax liabilities
Core deposit and other intangibles	2,057	3,040
Deferred loan fees, net	4,275	5,407
Fixed assets	5,270	6,168
Goodwill	10,265	14,737
Net unrealized gain on securities available for sale	0	105
Deferred Tax Liabilities, Derivatives	524	454
Other	4,307	3,909
Gross deferred tax liabilities	26,698	33,820
Total net deferred tax asset	$ 5,475	$ 15,534

INCOME TAXES (Details 3)

INCOME TAXES (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning Balance	$ 111	$ 81
Reduction of tax positions for prior years	0	0
Increase for prior year tax positions	0	0
Increase for current year tax positions	31	30
Ending Balance	$ 142	$ 111

INCOME TAXES (Details Textual)

INCOME TAXES (Details Textual) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Tax Expense related to a change in tax law	$ 2,361,000	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 466,000	$ 0	$ 0
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount									21,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense									18,000	11,000	$ 0
Deferred Tax Assets, Operating Loss Carryforwards	127,000				69,000				$ 127,000	$ 69,000
Computed statutory federal income tax provision									35.00%	35.00%	35.00%
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	29,000				$ 11,000				$ 29,000	$ 11,000
Net Deferred Tax Asset [Member]
Tax Expense related to a change in tax law	1,895,000								1,900,000
Investments in Low Income Housing Projects [Member]
Tax Expense related to a change in tax law	466,000								466,000
Deferred Tax Assets, Operating Loss Carryforwards	$ 121,000								$ 121,000

LOW INCOME HOUSING PROJECT I113

LOW INCOME HOUSING PROJECT INVESTMENTS Low Income Housing Project Investments (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Tax Expense related to a change in tax law	$ 2,361,000	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 466,000		$ 0	$ 0
Original Investment in Low Income Housing Projects	47,399,000				47,379,000				47,399,000		47,379,000	42,199,000
Amortization Method Qualified Affordable Housing Project Investments	35,225,000				39,606,000				35,225,000		39,606,000	38,151,000
Qualified Affordable Housing Project Investments, Commitment	4,536,000				$ 12,161,000				4,536,000		12,161,000	14,607,000
Affordable Housing Tax Credits and Other Tax Benefits, Amount									5,654,000		5,366,000	3,632,000
Amortization Method Qualified Affordable Housing Project Investments, Amortization									4,402,000	[1]	3,725,000	2,450,000
Income (Loss) from Affordable Housing Projects, Equity Method Investments									1,253,000		$ 1,641,000	$ 1,182,000
Investments in Low Income Housing Projects [Member]
Tax Expense related to a change in tax law	$ 466,000								$ 466,000
[1]	The 2017 amount is inclusive of $466,000 related to the revaluation of Low Income Housing tax credit investments as a result of the 2017 Tax Act.

EMPLOYEE BENEFIT PLANS (Details

EMPLOYEE BENEFIT PLANS (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension Plan [Member]
Multiemployer Plans [Line Items]
Multiemployer Plans, Funded Status	At least 80 percent	At least 80 percent
FIP/RP Status Pending/Implemented	No
Surcharge Imposed	No
Expiration Date of Collective-Bargaining Agreement	N/A
Minimum Contributions Required for Future Periods	$ 0
Supplemental Executive Retirement Plans [Member]
Multiemployer Plans [Line Items]
Defined Benefit Plan, Benefit Obligation	15,749,000	$ 14,177,000	$ 13,290,000	$ 12,537,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	461,000
Contributions paid	367,000	$ 320,000	$ 276,000
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	$ 454,000
Supplemental Executive Retirement Plans [Member] | Minimum [Member]
Multiemployer Plans [Line Items]
Discount rate used for benefit obligation	2.48%	2.49%	2.49%
Discount rate used for net periodic benefit cost	2.49%	2.49%	2.24%
Supplemental Executive Retirement Plans [Member] | Maximum [Member]
Multiemployer Plans [Line Items]
Discount rate used for benefit obligation	3.45%	3.94%	4.16%
Discount rate used for net periodic benefit cost	3.94%	4.16%	3.84%

EMPLOYEE BENEFIT PLANS (Deta115

EMPLOYEE BENEFIT PLANS (Details 1) - Pension Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Multiemployer Plans [Line Items]
Cash payment	$ 6,432	$ 6,245	$ 2,983
Multiemployer Plan Year Allocation Four [Member]
Multiemployer Plans [Line Items]
Cash payment	5,000	4,000	1,215
Multiemployer Plan Year Allocation One [Member]
Multiemployer Plans [Line Items]
Cash payment	$ 1,432
Multiemployer Plan Year Allocation Two [Member]
Multiemployer Plans [Line Items]
Cash payment		$ 2,245
Multiemployer Plan Year Allocation Three [Member]
Multiemployer Plans [Line Items]
Cash payment			$ 1,768

EMPLOYEE BENEFIT PLANS (Deta116

EMPLOYEE BENEFIT PLANS (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Retirement expense	$ 1,900	$ 2,000	$ 1,600
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Retirement expense	1,580	1,513	1,834
Contributions paid	$ 367	$ 320	$ 276

EMPLOYEE BENEFIT PLANS (Deta117

EMPLOYEE BENEFIT PLANS (Details 3) - Supplemental Executive Retirement Plans [Member] $ in Thousands	Dec. 31, 2017USD ($)
Defined Benefit Plan Disclosure [Line Items]
2,017	$ 408
2,018	481
2,019	467
2,020	461
2,021	454
2023-2027	$ 5,366

EMPLOYEE BENEFIT PLANS (Deta118

EMPLOYEE BENEFIT PLANS (Details 4) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Change in plan assets
Fair value of plan assets at beginning of year	$ 16,000
Fair value of plan assets at end of year	16,200	$ 16,000
Supplemental Executive Retirement Plans [Member]
Change in accumulated benefit obligation
Benefit obligation at beginning of year	14,177	13,290	$ 12,537
Accumulated service cost	423	395	742
Interest cost	547	539	470
Actuarial loss/(gain)	969	273	(183)
Accumulated benefit obligation at end of year	15,749	14,177	13,290
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(367)	(320)	(276)
Change in plan assets
Employer contribution	367	320	276
Defined Benefit Plan, Plan Assets, Benefits Paid	(367)	(320)	(276)
Funded status at end of year	(15,749)	(14,177)	(13,290)
Assets	0	0	0
Liabilities	(15,749)	(14,177)	(13,290)
Accrued benefit cost	(15,749)	(14,177)	(13,290)
Amounts recognized in accumulated other comprehensive income (“AOCI”)
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax	3,465	2,830	2,859
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax	1,047	1,323	1,599
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax	4,512	4,153	4,458
Information for plans with an accumulated benefit obligation in excess of plan assets
Projected benefit obligation	15,749	14,177	13,290
Accumulated benefit obligation	15,749	14,177	13,290
Net periodic benefit cost
Service cost	423	395	742
Interest cost	547	539	470
Amortization of prior service cost	276	276	305
Recognized net actuarial loss	334	303	317
Net periodic benefit cost	1,580	1,513	1,834
Amounts in accumulated other comprehensive income expected to be recognized in net periodic benefit cost over next fiscal year
Net actuarial loss	415	338	270
Net prior service cost	$ 276	$ 276	$ 276
Minimum [Member] | Supplemental Executive Retirement Plans [Member]
Amounts in accumulated other comprehensive income expected to be recognized in net periodic benefit cost over next fiscal year
Discount rate used for benefit obligation	2.48%	2.49%	2.49%
Discount rate used for net periodic benefit cost	2.49%	2.49%	2.24%
Maximum [Member] | Supplemental Executive Retirement Plans [Member]
Amounts in accumulated other comprehensive income expected to be recognized in net periodic benefit cost over next fiscal year
Discount rate used for benefit obligation	3.45%	3.94%	4.16%
Discount rate used for net periodic benefit cost	3.94%	4.16%	3.84%

EMPLOYEE BENEFIT PLANS (Deta119

EMPLOYEE BENEFIT PLANS (Details Textual)	12 Months Ended
	Dec. 31, 2017USD ($)ageshares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)
Defined Contribution Plan Disclosure [Line Items]
Incentive plans and discretionary bonus expense	$ 10,900,000	$ 10,300,000	$ 10,300,000
Employer matching contribution percent	25.00%
Employee contribution percent	6.00%
Nondiscretionary requisite service period	1 year
Defined Contribution Plan, Nondiscretionary Requisite service hours	1,000
Nondiscretionary employer contribution, percent up to social security limit	5.00%
Nondiscretionary employer contribution, percent over social security limit	10.00%
Supplemental Unemployment Benefit, Salary Continuation Expense	$ 11,000	13,000	11,000
Deferred Compensation Arrangement with Individual, Contributions by Employer	$ 143,000	142,000	149,000
Multiemployer Plans [Abstract]
Significance of contributions percentage	5.00%
Defined benefit plan expense	$ 1,900,000	2,000,000	1,600,000
Postretirement Benefits [Abstract]
Retirement age | age	65
Service period to be eligible for postretirement benefit	10 years
Death benefit	$ 5,000
Supplemental Executive Retirement Plans [Abstract]
Plan assets	$ 16,200,000	$ 16,000,000
Deferred Compensation Arrangements [Abstract]
Deferred compensation, shares provided for the plan (in shares) | shares	161,961	168,352
Deferred compensation, recorded liability	$ 4,500,000	$ 4,200,000
401(k) Restoration Plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan expense	267,000	425,000	232,000
Employee Savings Plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan expense	5,000,000	4,800,000	4,500,000
Executive Vice President [Member]
Defined Contribution Plan Disclosure [Line Items]
Supplemental Unemployment Benefits, Salary Continuation	279,000	272,000	222,000
Director [Member]
Defined Contribution Plan Disclosure [Line Items]
Supplemental Unemployment Benefits, Salary Continuation	$ 38,000	$ 40,000	$ 35,000

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities	$ 1,324,000	$ 804,000
Assets
Securities - available for sale	447,498,000	363,644,000
Disposal Group, Including Discontinued Operation, Mortgage Loans	4,768,000	6,139,000
Total	17,318,000	22,331,000
Fair Value, Measurements, Recurring [Member]
Liabilities
Total recurring fair value measurements	455,373,000	371,432,000
Fair Value, Measurements, Recurring [Member] | Trading securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities	1,324,000	804,000
Fair Value, Measurements, Recurring [Member] | U.S. Government agency securities
Assets
Securities - available for sale	35,430,000	24,244,000
Fair Value, Measurements, Recurring [Member] | Agency mortgage-backed securities
Assets
Securities - available for sale	215,764,000	175,384,000
Fair Value, Measurements, Recurring [Member] | Agency collateralized mortgage obligations
Assets
Securities - available for sale	122,012,000	99,868,000
Fair Value, Measurements, Recurring [Member] | State, county, and municipal securities
Assets
Securities - available for sale	2,274,000	3,793,000
Fair Value, Measurements, Recurring [Member] | Single issuer trust preferred securities issued by banks and insurers
Assets
Securities - available for sale	2,016,000	2,311,000
Fair Value, Measurements, Recurring [Member] | Pooled trust preferred securities issued by banks and insurers
Assets
Securities - available for sale	1,640,000	1,584,000
Fair Value, Measurements, Recurring [Member] | Small Business Administration Pooled Securities [Member]
Assets
Securities - available for sale	47,778,000	37,189,000
Fair Value, Measurements, Recurring [Member] | Equity securities
Assets
Securities - available for sale	20,584,000	19,271,000
Fair Value, Measurements, Recurring [Member] | Loans held for sale
Assets
Disposal Group, Including Discontinued Operation, Mortgage Loans	4,768,000	6,139,000
Fair Value, Measurements, Recurring [Member] | Derivative instruments
Assets
Total	17,476,000	22,761,000
Fair Value, Measurements, Recurring [Member] | Derivative instruments
Liabilities
Liabilities	15,693,000	21,916,000
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Liabilities
Total recurring fair value measurements	21,908,000	20,075,000
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Trading securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities	1,324,000	804,000
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | State, county, and municipal securities
Assets
Securities - available for sale		0
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Small Business Administration Pooled Securities [Member]
Assets
Securities - available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity securities
Assets
Securities - available for sale	20,584,000	19,271,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Liabilities
Total recurring fair value measurements	431,825,000	349,773,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. Government agency securities
Assets
Securities - available for sale	35,430,000	24,244,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Agency mortgage-backed securities
Assets
Securities - available for sale	215,764,000	175,384,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Agency collateralized mortgage obligations
Assets
Securities - available for sale	122,012,000	99,868,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | State, county, and municipal securities
Assets
Securities - available for sale	2,274,000	3,793,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Single issuer trust preferred securities issued by banks and insurers
Assets
Securities - available for sale	2,016,000	2,311,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Small Business Administration Pooled Securities [Member]
Assets
Securities - available for sale	47,778,000	37,189,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Loans held for sale
Assets
Securities - available for sale	4,768,000	6,139,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Derivative instruments
Assets
Total	17,476,000	22,761,000
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Derivative instruments
Liabilities
Liabilities	15,693,000	21,916,000
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Liabilities
Total recurring fair value measurements	1,640,000	1,584,000
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | U.S. Government agency securities
Assets
Securities - available for sale
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | State, county, and municipal securities
Assets
Securities - available for sale		0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Pooled trust preferred securities issued by banks and insurers
Assets
Securities - available for sale	1,640,000	1,584,000
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Small Business Administration Pooled Securities [Member]
Assets
Securities - available for sale	0	0
Fair Value, Measurements, Nonrecurring [Member]
Assets
Assets And Liabilities Fair Value Disclosure Nonrecurring	34,179,000	38,147,000
Fair Value, Measurements, Nonrecurring [Member] | Collateral dependent impaired loans
Assets
Assets nonrecurring	33,567,000	33,974,000
Fair Value, Measurements, Nonrecurring [Member] | Other real estate owned and other foreclosed assets
Assets
Assets nonrecurring	612,000	4,173,000
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets
Assets And Liabilities Fair Value Disclosure Nonrecurring	34,179,000	38,147,000
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Collateral dependent impaired loans
Assets
Assets nonrecurring	33,567,000	33,974,000
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other real estate owned and other foreclosed assets
Assets
Assets nonrecurring	$ 612,000	$ 4,173,000

FAIR VALUE MEASUREMENTS (Det121

FAIR VALUE MEASUREMENTS (Details 1) - Pooled Trust Preferred Securities [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation for all assets and liabilities measured at fair value on a recurring basis
Beginning balance	$ 1,584	$ 1,572	$ 6,321
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0	0	(4,679)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases, (Sales), Issuances, (Settlements)	(21)	(17)	(84)
Sales	77	29	14
Ending Balance	$ 1,640	$ 1,584	$ 1,572

FAIR VALUE MEASUREMENTS (Det122

FAIR VALUE MEASUREMENTS (Details 2) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets, Quantitative Information [Line Items]
Securities - available for sale		$ 447,498	$ 363,644
Weighted Average [Member] | Discounted cash flow methodology [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets, Quantitative Information [Line Items]
Cumulative Prepayment		2.50%	2.50%
Cumulative Default		12.40%	12.80%
Loss Given Default		94.30%	94.20%
Cure Given Default		60.90%	60.90%
Pooled Trust Preferred Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets, Quantitative Information [Line Items]
Securities - available for sale		$ 1,640	$ 1,584
Pooled Trust Preferred Securities [Member] | Minimum [Member] | Discounted cash flow methodology [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets, Quantitative Information [Line Items]
Cumulative Prepayment		0.00%	0.00%
Cumulative Default		5.00%	5.00%
Loss Given Default		85.00%	85.00%
Cure Given Default		0.00%	0.00%
Pooled Trust Preferred Securities [Member] | Maximum [Member] | Discounted cash flow methodology [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets, Quantitative Information [Line Items]
Cumulative Prepayment		61.00%	62.00%
Cumulative Default		100.00%	100.00%
Loss Given Default		100.00%	100.00%
Cure Given Default		75.00%	75.00%
Impaired Loans [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets, Quantitative Information [Line Items]
Assets, Fair Value Disclosure, Recurring	[1]	$ 33,567	$ 33,974
Other real estate owned and other foreclosed assets | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets, Quantitative Information [Line Items]
Assets, Fair Value Disclosure, Recurring	[1]	$ 612	$ 4,173
[1]	Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various Level 3 inputs which are not identifiable. Appraisals may be adjusted by management for qualitative factors such as economic factors and estimated liquidation expenses. The range of these possible adjustments may vary.

FAIR VALUE MEASUREMENTS (Det123

FAIR VALUE MEASUREMENTS (Details 3) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities		$ 497,688	$ 487,076
Loans and Leases Receivable, Net Amount		6,294,910	5,938,039
Securities held to maturity, fair value		494,194	485,650
Federal Home Loan Bank Stock		11,597	11,497
Bank Owned Life Insurance		151,528	144,503
Liabilities, Fair Value Disclosure [Abstract]
Advances from Federal Home Loan Banks		53,264	50,819
Junior subordinated debentures		73,073	73,107
Subordinated Debt		34,682	34,635
Deposits [Member]
Liabilities, Fair Value Disclosure [Abstract]
Financial Liabilities Book Value	[1]	6,084,952	5,763,101
Accrued Liabilities, Fair Value Disclosure	[1]	6,084,952	5,763,101
Bank Time Deposits [Member]
Liabilities, Fair Value Disclosure [Abstract]
Financial Liabilities Book Value	[2]	644,301	649,152
Accrued Liabilities, Fair Value Disclosure	[2]	639,060	647,038
Federal Home Loan Bank Advances [Member]
Liabilities, Fair Value Disclosure [Abstract]
Advances from Federal Home Loan Banks	[2]	53,264	50,819
Federal Home Loan Bank Borrowings, Fair Value Disclosure	[2]	52,111	50,898
Customer Repurchase Agreements [Member]
Liabilities, Fair Value Disclosure [Abstract]
Customer Repurchase Agreements and other short-term borrowings	[2]	162,679	176,913
Accrued Liabilities, Fair Value Disclosure	[2]	162,679	176,913
Junior Subordinated Debt [Member]
Liabilities, Fair Value Disclosure [Abstract]
Junior subordinated debentures	[3]	73,073	73,107
Accrued Liabilities, Fair Value Disclosure	[3]	74,680	72,510
Subordinated Debt [Member]
Liabilities, Fair Value Disclosure [Abstract]
Subordinated Debt	[2]	34,682	34,635
Accrued Liabilities, Fair Value Disclosure	[2]	32,707	34,241
Significant Other Observable Inputs (Level 2) [Member] | Deposits [Member]
Liabilities, Fair Value Disclosure [Abstract]
Accrued Liabilities, Fair Value Disclosure	[1]	6,084,952	5,763,101
Significant Other Observable Inputs (Level 2) [Member] | Bank Time Deposits [Member]
Liabilities, Fair Value Disclosure [Abstract]
Accrued Liabilities, Fair Value Disclosure	[2]	639,060	647,038
Significant Other Observable Inputs (Level 2) [Member] | Federal Home Loan Bank Advances [Member]
Liabilities, Fair Value Disclosure [Abstract]
Federal Home Loan Bank Borrowings, Fair Value Disclosure	[2]	52,111
Accrued Liabilities, Fair Value Disclosure	[2]		50,898
Significant Other Observable Inputs (Level 2) [Member] | Junior Subordinated Debt [Member]
Liabilities, Fair Value Disclosure [Abstract]
Accrued Liabilities, Fair Value Disclosure	[3]	74,680	72,510
Significant Unobservable Inputs (Level 3) [Member] | Customer Repurchase Agreements [Member]
Liabilities, Fair Value Disclosure [Abstract]
Accrued Liabilities, Fair Value Disclosure	[2]	162,679	176,913
Significant Unobservable Inputs (Level 3) [Member] | Subordinated Debt [Member]
Liabilities, Fair Value Disclosure [Abstract]
Accrued Liabilities, Fair Value Disclosure	[2]	32,707	34,241
US Treasury Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities	[4]	1,006	1,007
Securities held to maturity, fair value	[4]	1,035	1,054
US Treasury Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	[4]	1,035	1,054
Agency mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities	[4]	204,768	156,088
Securities held to maturity, fair value	[4]	205,823	157,504
Agency mortgage-backed securities | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	[4]	205,823	157,504
Agency collateralized mortgage obligations
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities	[4]	262,998	297,445
Securities held to maturity, fair value	[4]	258,408	294,650
Agency collateralized mortgage obligations | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	[4]	258,408	294,650
Single issuer trust preferred securities issued by banks and insurers
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities	[4]	1,500	1,500
Securities held to maturity, fair value	[4]	1,529	1,544
Single issuer trust preferred securities issued by banks and insurers | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	[4]	1,529	1,544
Small Business Administration Pooled Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities	[4]	27,416	31,036
Securities held to maturity, fair value	[4]	27,399	30,898
Small Business Administration Pooled Securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	[4]	0	0
Small Business Administration Pooled Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	[4]	27,399	30,898
Small Business Administration Pooled Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	[4]	0	0
Loans Net Of Allowance For Loan Loses [Member]
Assets, Fair Value Disclosure [Abstract]
Loans and Leases Receivable, Net Amount	[5]	6,261,343	5,904,065
Loans, net of allowance for loan losses	[5]	6,116,051	5,784,778
Loans Net Of Allowance For Loan Loses [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets, Fair Value Disclosure [Abstract]
Loans, net of allowance for loan losses	[5]	6,116,051	5,784,778
Investment in Federal Home Loan Bank Stock [Member]
Assets, Fair Value Disclosure [Abstract]
Federal Home Loan Bank Stock	[6]	11,597	11,497
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	[6]	11,597	11,497
Investment in Federal Home Loan Bank Stock [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets, Fair Value Disclosure [Abstract]
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	[6]	0	0
Investment in Federal Home Loan Bank Stock [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	[6]	11,597	11,497
Investment in Federal Home Loan Bank Stock [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets, Fair Value Disclosure [Abstract]
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	[6]	0	0
Cash Surrender Value [Member]
Assets, Fair Value Disclosure [Abstract]
Bank Owned Life Insurance	[7]	151,528	144,503
Cash Surrender Value, Fair Value Disclosure	[7]	151,528	144,503
Cash Surrender Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets, Fair Value Disclosure [Abstract]
Cash Surrender Value, Fair Value Disclosure	[7]	0	0
Cash Surrender Value [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Cash Surrender Value, Fair Value Disclosure	[7]	151,528	144,503
Cash Surrender Value [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets, Fair Value Disclosure [Abstract]
Cash Surrender Value, Fair Value Disclosure	[7]	$ 0	$ 0
[1]	Fair value of demand deposits, savings and interest checking accounts and money market deposits is the amount payable on demand at the reporting date.
[2]	Fair value was determined by discounting anticipated future cash payments using rates currently available for instruments with similar remaining maturities.
[3]	Fair value was determined based upon market prices of securities with similar terms and maturities.
[4]	The fair values presented are based on quoted market prices, where available. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments and/or discounted cash flow analysis.
[5]	Fair value is estimated by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities or cash flows. Additionally, this amount excludes collateral dependent impaired loans, which are deemed to be marked to fair value on a nonrecurring basis.
[6]	FHLB stock has no quoted market value and is carried at cost, therefore the carrying amount approximates fair value.
[7]	Cash surrender value of life insurance is recorded at its cash surrender value (or the amount that can be realized upon surrender of the policy), therefore carrying amount approximates fair value.

OTHER COMPREHENSIVE LOSS (Detai

OTHER COMPREHENSIVE LOSS (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax, Portion Attributable to Parent		$ 322	$ 699	$ 1,269
Other Comprehensive Income (Loss), before Tax [Abstract]
Change in fair value of securities available for sale, pre tax amount		996	1,858	3,757
Change in fair value of cash flow hedges, pre tax amount		307	1,133	(776)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Borrowings Expense, before Tax	[1]	(441)	(2,520)	(2,828)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax, Portion Attributable to Parent		748	3,653	2,052
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax		(995)	(383)	438
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax		278	238	243
Amortization of certain costs included in net periodic retirement costs, pre tax amount		(276)	(276)	(294)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	[2]	(441)	131	975
Total other comprehensive loss, pre tax amount		(692)	1,952	(325)
Other Comprehensive Income (Loss), Tax [Abstract]
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax		321	710	1,434
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax		(125)	(453)	299
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Borrowings Expense, Tax	[1]	180	1,030	1,152
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax, Portion Attributable to Parent		(305)	(1,483)	(853)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax		407	157	(193)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax		(113)	(97)	(99)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax		(113)	(113)	(119)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	[2]	181	(53)	(411)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent		198	(837)	5
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax		(675)	(1,148)	(2,323)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent		(677)	(1,133)	(2,083)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax		182	680	(477)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Borrowings Expense, Net of Tax	[1]	(261)	(1,490)	(1,676)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent		443	2,170	1,199
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax		(588)	(226)	245
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax		165	141	144
Amortization of certain costs included in net periodic retirement costs, after tax amount		163	163	175
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	[2]	(260)	78	564
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		(494)	1,115	(320)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax		3	(26)	(405)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax		(1)	11	165
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax		2	(15)	(240)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax, Portion Attributable to Parent		$ (999)	$ (1,832)	$ (3,352)
[1]	Includes the amortization of the remaining balance of a realized but unrecognized gain, net of tax, from the termination of interest rate swaps in 2009. The original gain of $1.4 million, net of tax, will be recognized in earnings through December 2018, the original maturity date of the swap. The balance of this gain had amortized to $137,000, $281,000, and $427,000 at December 31, 2017, 2016, and 2015, respectively.
[2]	The amortization of prior service costs is included in the computation of net periodic pension costs as disclosed in Note 15 - Employee Benefit Plans.

OTHER COMPREHENSIVE LOSS (De125

OTHER COMPREHENSIVE LOSS (Details 1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	$ (1,337)	$ (2,452)	$ (2,132)
Total other comprehensive income (loss)	(494)	1,115	(320)
Ending Balance	(1,831)	(1,337)	(2,452)
Unrealized Gain (Loss) on Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	173	1,306	3,389
Total other comprehensive income (loss)	(677)	(1,133)	(2,083)
Ending Balance	(504)	173	1,306
Unrealized Gain (Loss) on Cash Flow Hedge
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	361	(1,955)	(3,298)
Total other comprehensive income (loss)	587	2,316	1,343
Ending Balance	948	361	(1,955)
Deferred Gain on Hedge Transactions
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	281	427	571
Total other comprehensive income (loss)	(144)	(146)	(144)
Ending Balance	137	281	427
Defined Benefit Postretirement Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(2,152)	(2,230)	(2,794)
Total other comprehensive income (loss)	(260)	78	564
Ending Balance	$ (2,412)	$ (2,152)	$ (2,230)

OTHER COMPREHENSIVE LOSS (De126

OTHER COMPREHENSIVE LOSS (Details Textual) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2009
Equity [Abstract]
Gain on interest rate swaps	$ 137,000	$ 281,000	$ 427,000	$ 1,400,000

COMMITMENTS AND CONTINGENCIES F

COMMITMENTS AND CONTINGENCIES Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet financial instruments	$ 2,443,478	$ 2,227,955
Standby letters of credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet financial instruments	15,534	18,190
Deferred standby letter of credit fees [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet financial instruments	$ 102	$ 108

COMMITMENTS AND CONTINGENCIES L

COMMITMENTS AND CONTINGENCIES Lease Commitments (Details 1) $ in Thousands	Dec. 31, 2017USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2,017	$ 9,023
2,018	8,808
2,019	7,771
2,020	6,508
2,021	4,437
Thereafter	8,214
Total future minimum rentals	$ 44,761

COMMITMENTS AND CONTINGENCIE129

COMMITMENTS AND CONTINGENCIES (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Leases, Rent Expense, Net [Abstract]
Operating lease rent expense	$ 8.6	$ 8.5	$ 8.2
Reserve requirement	$ 35.8	$ 31.8
Minimum [Member]
Operating Leases, Rent Expense, Net [Abstract]
Operating lease renewal period option	4 months
Maximum [Member]
Operating Leases, Rent Expense, Net [Abstract]
Operating lease renewal period option	10 years

REGULATORY CAPITAL REQUIREME130

REGULATORY CAPITAL REQUIREMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Company (consolidated) [Member]
Total capital (to risk weighted assets):
Actual	$ 886,807	$ 824,265
Actual Ratio	13.82%	13.60%
Capital Required for Capital Adequacy	$ 513,398	$ 484,942
For Capital Adequacy Purposes Ratio	8.00%	8.00%
Common Equity Tier One Capital	$ 718,995	$ 656,080
Common Equity tier One Capital to Risk Weighted Assets	11.20%	10.82%
Common Equity Tier One Capital Required for Capital Adequacy	$ 288,787	$ 272,780
Common Equity Tier One Capital for Capitalized Adequacy to Risk Weighted Assets	4.50%	4.50%
Tier 1 capital (to risk weighted assets):
Actual	$ 789,992	$ 727,070
Actual Ratio	12.31%	11.99%
For Capital Adequacy Purposes	$ 385,049	$ 363,706
For Capital Adequacy Purposes Ratio	6.00%	6.00%
Tier 1 capital (to average assets):
Actual	$ 789,992	$ 727,070
Actual Ratio	10.04%	9.77%
For Capital Adequacy Purposes	$ 314,756	$ 297,748
For Capital Adequacy Purposes Ratio	4.00%	4.00%
Bank [Member]
Total capital (to risk weighted assets):
Actual	$ 846,147	$ 788,320
Actual Ratio	13.19%	13.01%
Capital Required for Capital Adequacy	$ 513,175	$ 484,834
For Capital Adequacy Purposes Ratio	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions	$ 641,469	$ 606,042
To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	10.00%	10.00%
Common Equity Tier One Capital	$ 784,014	$ 725,760
Common Equity tier One Capital to Risk Weighted Assets	12.22%	11.98%
Common Equity Tier One Capital Required for Capital Adequacy	$ 288,661	$ 272,719
Common Equity Tier One Capital for Capitalized Adequacy to Risk Weighted Assets	4.50%	4.50%
Common Equity Tier 1 Capital to be Well Capitalized	$ 416,955	$ 393,927
Common Equity Tier One Capital to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
Tier 1 capital (to risk weighted assets):
Actual	$ 784,014	$ 725,760
Actual Ratio	12.22%	11.98%
For Capital Adequacy Purposes	$ 384,881	$ 363,625
For Capital Adequacy Purposes Ratio	6.00%	6.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions	$ 513,175	$ 484,834
To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	8.00%	8.00%
Tier 1 capital (to average assets):
Actual	$ 784,014	$ 725,760
Actual Ratio	9.97%	9.76%
For Capital Adequacy Purposes	$ 314,630	$ 297,589
For Capital Adequacy Purposes Ratio	4.00%	4.00%
To Be Well Capitalized Under Prompt Correction Action Provisions	$ 393,288	$ 371,986
To Be Well Capitalized Under Prompt Correction Action Provisions Ratio	5.00%	5.00%

REGULATORY CAPITAL REQUIREME131

REGULATORY CAPITAL REQUIREMENTS Regulatory Capital Requirements (Details Textual) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Dividends received from subsidiaries(1)	$ (46.9)	$ (44.5)
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 71	$ 71

PARENT COMPANY FINANCIALS ON132

PARENT COMPANY FINANCIALS ONLY (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets:
Deferred tax asset		$ 32,173	$ 49,354
Derivative Asset		17,318	22,331
Total assets		8,082,029	7,709,375
Liabilities and stockholders’ equity
Junior subordinated debentures		73,073	73,107
Subordinated Debt		34,682	34,635
Other liabilities		85,269	96,958
Total liabilities		7,138,220	6,844,685
Stockholders’ equity		943,809	864,690	$ 771,463	$ 640,527
Liabilities and Equity		8,082,029	7,709,375
Consolidation, Eliminations [Member]
Assets:
Investments in subsidiaries		1,000,000	933,600
Parent Company [Member]
Assets:
Cash	[1]	48,131	42,596
Investments in subsidiaries	[2]	1,010,125	935,778
Prepaid income taxes		786	625
Deferred tax asset		96	216
Derivative Asset	[1]	1,535	1,364
Total assets		1,060,673	980,579
Liabilities and stockholders’ equity
Dividends payable		8,786	7,834
Junior subordinated debentures		73,073	73,107
Subordinated Debt		34,682	34,635
Other liabilities		323	313
Total liabilities		116,864	115,889
Stockholders’ equity		943,809	864,690
Liabilities and Equity		$ 1,060,673	$ 980,579
[1]	Entire balance eliminates in consolidation.
[2]	$1.0 billion and $933.6 million eliminate in consolidation at December 31, 2017 and 2016, respectively.

PARENT COMPANY FINANCIALS ON133

PARENT COMPANY FINANCIALS ONLY (Details 1) - USD ($)		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Derivative Asset		$ 17,318,000				$ 22,331,000				$ 17,318,000	$ 22,331,000
Income
Dividends received from subsidiaries(1)										46,900,000	44,500,000
Expenses
Interest expense		5,044,000	$ 4,705,000	$ 4,378,000	$ 4,207,000	4,676,000	$ 4,640,000	$ 4,627,000	$ 4,850,000	18,334,000	18,793,000	$ 20,617,000
Income tax benefit		14,915,000	12,681,000	10,731,000	9,014,000	7,698,000	9,793,000	9,508,000	8,428,000	47,341,000	35,427,000	27,218,000
Net Income		22,064,000	$ 23,852,000	$ 20,563,000	$ 20,725,000	17,179,000	$ 20,484,000	$ 20,374,000	$ 18,611,000	87,204,000	76,648,000	64,960,000
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Dividend Income, Operating	[1]									47,006,000	44,598,000	38,153,000
Derivative Asset	[2]	$ 1,535,000				$ 1,364,000				1,535,000	1,364,000
Income
Interest income(2)	[3]									50,000	98,000	78,000
Total income										47,056,000	44,696,000	38,231,000
Expenses
Interest expense										3,995,000	5,901,000	5,769,000
Other expenses												29,000
Total expenses										3,995,000	5,901,000	5,798,000
Income before income taxes and equity in undistributed income of subsidiaries										43,061,000	38,795,000	32,433,000
Income tax benefit										(1,523,000)	(1,791,000)	(2,301,000)
Income of parent company										44,584,000	40,586,000	34,734,000
Equity in undistributed income of subsidiaries										42,620,000	36,062,000	30,226,000
Net Income										87,204,000	76,648,000	64,960,000
Consolidation, Eliminations [Member]
Income
Dividends received from subsidiaries(1)										$ 67,000	$ 62,000	$ 55,000
[1]	Income of $67,000, $62,000 and $55,000 was not eliminated in consolidation for the years ended December 31, 2017, 2016, and 2015, respectively.
[2]	Entire balance eliminates in consolidation.
[3]	Entire balance eliminated in consolidation.

PARENT COMPANY FINANCIALS ON134

PARENT COMPANY FINANCIALS ONLY (Details 2) - USD ($)		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Dividends received from subsidiaries(1)										$ (46,900,000)	$ (44,500,000)
Net income		$ 22,064,000	$ 23,852,000	$ 20,563,000	$ 20,725,000	$ 17,179,000	$ 20,484,000	$ 20,374,000	$ 18,611,000	87,204,000	76,648,000	$ 64,960,000
Adjustments to reconcile net income to net cash provided by operating activities
Deferred income tax expense										9,211,000	(5,000)	10,220,000
Change in other assets										20,022,000	7,627,000	3,842,000
Change in other liabilities										(3,825,000)	(8,738,000)	(2,450,000)
Net cash provided by operating activities										130,909,000	93,336,000	89,543,000
Cash flows used in investing activities
Net cash used in investing activities										(316,769,000)	(238,886,000)	(205,541,000)
Cash flows provided by financing activities
Restricted stock awards issued, net of awards surrendered										(1,422,000)	(696,000)	(657,000)
Cash received from stock option exercises										214,000	201,000	1,367,000
Proceeds from shares issued under the direct stock purchase plan										1,636,000	2,323,000	2,695,000
Common dividends paid										(34,045,000)	(29,711,000)	(26,172,000)
Net cash provided by financing activities										109,881,000	158,880,000	213,509,000
Net increase (decrease) in cash and cash equivalents										(75,979,000)	13,330,000	97,511,000
Cash and cash equivalents at beginning of year					289,095,000				275,765,000	289,095,000	275,765,000	178,254,000
Cash and cash equivalents at end of period		213,116,000				289,095,000				213,116,000	289,095,000	275,765,000
Consolidation, Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Dividends received from subsidiaries(1)										(67,000)	(62,000)	(55,000)
Investments in subsidiaries		1,000,000,000				933,600,000				1,000,000,000	933,600,000
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Investments in subsidiaries	[1]	1,010,125,000				935,778,000				1,010,125,000	935,778,000
Net income										87,204,000	76,648,000	64,960,000
Adjustments to reconcile net income to net cash provided by operating activities
Amortization (accretion)										12,000	(154,000)	(150,000)
Deferred income tax expense										51,000	678,000	3,266,000
Change in other assets										(99,000)	423,000	7,488,000
Change in other liabilities										(562,000)	(5,532,000)	(254,000)
Equity in undistributed income of subsidiaries										(42,620,000)	(36,062,000)	(30,226,000)
Net cash provided by operating activities										43,986,000	36,001,000	45,084,000
Cash flows used in investing activities
Cash paid for acquisitions, net of cash acquired (1)	[2]									(4,834,000)	(950,000)	(51,680,000)
Net cash used in investing activities										(4,834,000)	(950,000)	(51,680,000)
Cash flows provided by financing activities
Restricted stock awards issued, net of awards surrendered										(1,422,000)	(696,000)	(657,000)
Cash received from stock option exercises										214,000	201,000	1,367,000
Proceeds from shares issued under the direct stock purchase plan										1,636,000	2,323,000	2,695,000
Common dividends paid										(34,045,000)	(29,711,000)	(26,172,000)
Net cash provided by financing activities										(33,617,000)	(27,883,000)	(22,767,000)
Net increase (decrease) in cash and cash equivalents										5,535,000	7,168,000	(29,363,000)
Cash and cash equivalents at beginning of year					$ 42,596,000				$ 35,428,000	42,596,000	35,428,000	64,791,000
Cash and cash equivalents at end of period		48,131,000				42,596,000				48,131,000	42,596,000	$ 35,428,000
Cash	[3]	$ 48,131,000				$ 42,596,000				$ 48,131,000	$ 42,596,000
[1]	$1.0 billion and $933.6 million eliminate in consolidation at December 31, 2017 and 2016, respectively.
[2]	The majority of the net assets acquired at the parent company represented each of the acquired companies' investments in their wholly owned subsidiaries, which were eliminated in consolidation at December 31, 2017, 2016, and 2015, respectively.
[3]	Entire balance eliminates in consolidation.

SELECTED QUARTERLY FINANCIAL135

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income	$ 72,876,000	$ 71,778,000	$ 68,133,000	$ 64,407,000	$ 63,428,000	$ 62,308,000	$ 61,160,000	$ 59,741,000	$ 277,194,000	$ 246,637,000	$ 235,545,000
Interest expense	5,044,000	4,705,000	4,378,000	4,207,000	4,676,000	4,640,000	4,627,000	4,850,000	18,334,000	18,793,000	20,617,000
Net interest income	67,832,000	67,073,000	63,755,000	60,200,000	58,752,000	57,668,000	56,533,000	54,891,000	258,860,000	227,844,000	214,928,000
Provision (benefit)	1,300,000	0	1,050,000	600,000	4,000,000	950,000	600,000	525,000	2,950,000	6,075,000	1,500,000
Total noninterest income	21,914,000	20,770,000	21,398,000	18,912,000	21,762,000	20,416,000	21,095,000	19,155,000	82,994,000	82,428,000	75,888,000
Total noninterest expenses	51,467,000	51,310,000	52,809,000	48,773,000	51,637,000	46,857,000	47,146,000	46,482,000	204,359,000	192,122,000	197,138,000
Provision for income taxes	14,915,000	12,681,000	10,731,000	9,014,000	7,698,000	9,793,000	9,508,000	8,428,000	47,341,000	35,427,000	27,218,000
Net Income	$ 22,064,000	$ 23,852,000	$ 20,563,000	$ 20,725,000	$ 17,179,000	$ 20,484,000	$ 20,374,000	$ 18,611,000	$ 87,204,000	$ 76,648,000	$ 64,960,000
Basic earnings per share (in dollars per share)	$ 0.80	$ 0.87	$ 0.75	$ 0.77	$ 0.64	$ 0.78	$ 0.77	$ 0.71	$ 3.19	$ 2.90	$ 2.51
Weighted average common shares (basic) (in shares)	27,445,739	27,436,792	27,257,799	27,029,640	26,710,029	26,324,316	26,304,129	26,275,323	27,294,028	26,404,071	25,891,382
Diluted earnings per share (in dollars per share)	$ 0.80	$ 0.87	$ 0.75	$ 0.76	$ 0.64	$ 0.78	$ 0.77	$ 0.71	$ 3.19	$ 2.90	$ 2.50
Common share equivalents (in shares)	77,615	76,307	74,497	81,283	60,022	53,072	47,885	43,409	78,076	51,847	68,566
Weighted average common shares (diluted) (in shares)	27,523,354	27,513,099	27,332,296	27,110,923	26,770,051	26,377,388	26,352,014	26,318,732	27,372,104	26,455,918	25,959,948
Gains (Losses) on Extinguishment of Debt	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 437,000	$ 0	$ 437,000	$ 122,000
Acquisition Related Costs	0	0	2,909,000	484,000	4,764,000	151,000	206,000	334,000	3,393,000	5,455,000	10,501,000
Total unusual or infrequent expense items	0	0	2,909,000	484,000	4,764,000	151,000	206,000	771,000
Tax Expense related to a change in tax law	2,361,000	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	466,000	$ 0	$ 0
Investments in Low Income Housing Projects [Member]
Tax Expense related to a change in tax law	466,000								466,000
Net Deferred Tax Asset [Member]
Tax Expense related to a change in tax law	$ 1,895,000								$ 1,900,000

TRANSACTIONS WITH RELATED PA136

TRANSACTIONS WITH RELATED PARTIES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Loans and Leases Receivable, Related Parties	$ 52,458		$ 22,795	$ 24,653
Loans and Leases Receivable, Related Parties, Additions	36,800	[1]	1,718
Loans and Leases Receivable, Related Parties, Collections	$ (7,137)		$ (3,576)
[1]	(1) Includes $31.3 million of loans associated with a newly appointed director during the year, which represent the outstanding loan balances at the effective date of appointment.

TRANSACTIONS WITH RELATED PA137

TRANSACTIONS WITH RELATED PARTIES Related Parties Textual (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction	$ 31,300,000
Operating Leases, Rent Expense	8,600,000	$ 8,500,000	$ 8,200,000
Related Party Deposit Liabilities	18,300,000	14,700,000
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Operating Leases, Rent Expense	$ 0	$ 0