Seacoast Banking Corporation of Florida (SBCF) 10-K 28 Feb 18 2017 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Jun. 30, 2017
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Entity Registrant Name	SEACOAST BANKING CORP OF FLORIDA
Entity Central Index Key	730,708
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			$ 1,005,690,952
Trading Symbol	SBCF
Entity Common Stock, Shares Outstanding		46,917,528

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest on securities
Taxable	$ 34,442	$ 26,133	$ 20,341
Nontaxable	913	1,036	585
Interest and fees on loans	153,825	119,217	94,469
Interest on federal funds sold and other investments	2,416	1,669	1,022
Total interest income	191,596	148,055	116,417
INTEREST EXPENSE
Interest on savings deposits	3,654	2,593	2,085
Interest on time certificates	4,678	2,074	1,228
Interest on federal funds purchased and other short term borrowings	781	484	340
Interest on Federal Home Loan Bank borrowings	3,744	1,256	1,643
Interest on subordinated debt	2,443	2,060	1,634
Total interest expense	15,300	8,467	6,930
NET INTEREST INCOME	176,296	139,588	109,487
Provision for loan losses	5,648	2,411	2,644
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	170,648	137,177	106,843
NONINTEREST INCOME (Note M)
Bargain purchase gain	0	0	416
Gain on sale of VISA stock	15,153	0	0
Securities gains, net (includes net gains of $1,950, and net losses of ($617) and ($325) in other comprehensive income reclassifications for 2017, 2016, and 2015 respectively)	86	368	161
Other	43,230	37,427	32,018
Total noninterest income	58,469	37,795	32,595
NONINTEREST EXPENSE (Note M)	149,916	130,881	103,770
INCOME BEFORE INCOME TAXES	79,201	44,091	35,668
Income taxes	36,336	14,889	13,527
NET INCOME	$ 42,865	$ 29,202	$ 22,141
Net income per share of common stock
Diluted (in dollars per share)	$ 0.99	$ 0.78	$ 0.66
Basic (in dollars per share)	$ 1.01	$ 0.79	$ 0.66
Average common shares outstanding
Diluted (in shares)	43,350,314	37,508,046	33,744,171
Basic (in shares)	42,613,086	36,872,007	33,495,827

CONSOLIDATED STATEMENTS OF INC3

CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reclassification adjustment for securities gains (losses) included in net losses	$ 1,950	$ (617)	$ (325)

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
NET INCOME	$ 42,865	$ 29,202	$ 22,141
Other comprehensive income (loss):
Unrealized gains (losses) on securities available for sale	5,976	(2,129)	(2,634)
Amortization of unrealized losses on securities transferred to held to maturity, net	596	488	539
Reclassification adjustment for gains included in net income	(86)	(368)	(161)
(Provision) benefit for income taxes	(2,483)	709	870
Total other comprehensive income (loss)	4,003	(1,300)	(1,386)
COMPREHENSIVE INCOME	$ 46,868	$ 27,902	$ 20,755

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and due from banks		$ 104,039	$ 82,520
Interest bearing deposits with other banks		5,465	27,124
Total cash and cash equivalents		109,504	109,644
Time deposits with other banks		12,553	0
Securities available for sale (at fair value)		955,804	950,503
Securities held to maturity (fair value $414,470 in 2017 and $369,881 in 2016 )		416,863	372,498
Total securities		1,372,667	1,323,001
Loans held for sale		24,306	15,332
Loans	[1]	3,817,377	2,879,536
Less: Allowance for loan losses		(27,122)	(23,400)
Net loans		3,790,255	2,856,136
Bank premises and equipment, net		66,883	58,684
Other real estate owned		7,640	9,949
Goodwill		147,578	64,649
Other intangible assets, net		19,099	14,572
Bank owned life insurance		123,981	84,580
Net deferred tax assets		25,417	60,818
Other assets		110,246	83,567
TOTAL ASSETS		5,810,129	4,680,932
LIABILITIES
Noninterest demand		1,400,227	1,148,309
Interest-bearing demand		1,050,755	873,727
Savings		434,346	346,662
Money market		931,458	802,697
Other time deposits		414,277	276,607
Brokered time certificates		217,385	7,342
Time certificates of more than $250,000		144,272	67,901
Total deposits		4,592,720	3,523,245
Securities sold under agreements to repurchase, maturing within 30 days		216,094	204,202
Federal Home Loan Bank borrowings		211,000	415,000
Subordinated debt		70,521	70,241
Other liabilities		30,130	32,847
TOTAL LIABILITIES		5,120,465	4,245,535
Commitments and Contingencies (Notes K and P)
SHAREHOLDERS' EQUITY
Common stock, par value $0.10 per share authorized 60,000,000 shares, issued 47,032,259 and outstanding 46,917,735 shares in 2017 and authorized 60,000,000 shares, issued 38,090,568 and outstanding 38,021,835 shares in 2016		4,693	3,802
Additional paid-in capital		661,632	454,001
Retained earnings (accumulated deficit)		29,914	(13,657)
Less: Treasury stock (114,524 shares in 2017 and 68,733 shares in 2016), at cost		(2,359)	(1,236)
Total shareholders' equity before accumulated other comprehensive income, net		693,880	442,910
Accumulated other comprehensive loss, net		(4,216)	(7,513)
TOTAL SHAREHOLDERS' EQUITY		689,664	435,397
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY		$ 5,810,129	$ 4,680,932
[1]	Net loan balances at December 31, 2017 and 2016 include deferred costs of $11.5 million and $10.6 million, respectively.

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Held for Investment, Fair Value, Total	$ 414,470	$ 369,881
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	47,032,259	38,090,568
Common stock, shares outstanding	46,917,735	38,021,835
Treasury Stock, Shares	114,524	68,733

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 42,865	$ 29,202	$ 22,141
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	5,614	5,076	3,773
Amortization of premiums and discounts on securities, net	3,977	7,559	3,920
Other amortization and accretion, net	(697)	(2,238)	(1,601)
Stock based compensation	5,267	4,154	2,859
Origination of loans designated for sale	(213,027)	(175,842)	(206,199)
Sale of loans designated for sale	211,091	190,843	199,425
Provision for loan losses	5,648	2,411	2,644
Deferred income taxes	35,827	14,206	12,888
Gains on sale of securities	(86)	(368)	(161)
Gain on sale of VISA Class B stock	(15,153)	0	0
Gains on sale of loans	(7,038)	(6,335)	(5,146)
Losses (gains) on sale and write-downs of other real estate owned	(711)	(509)	239
Losses on disposition of fixed assets	2,270	2,442	183
Changes in operating assets and liabilities, net of effects from acquired companies:
Net increase in other assets	(5,506)	(11,573)	(4,828)
Net increase (decrease) in other liabilities	(21,432)	2,979	(628)
Net cash provided by operating activities	48,909	62,007	29,509
CASH FLOWS FROM INVESTING ACTIVITIES
Maturities and repayments of securities available for sale	211,173	127,879	118,493
Maturities and repayments of securities held for investment	86,460	48,705	28,629
Proceeds from sale of securities available for sale	235,613	40,421	60,314
Purchases of securities available for sale	(371,926)	(297,719)	(159,616)
Purchases of securities held for investment	(131,439)	(218,654)	(24,366)
Maturities of time deposits with other banks	4,720	0	0
Net new loans and principal repayments	(328,868)	(396,862)	(224,391)
Proceeds from the sale of portfolio loans	106,815	71,433	525
Purchases of loans held for investment	(55,352)	(64,925)	0
Proceeds from the sale of other real estate owned	6,069	7,952	5,758
Proceeds from sale of Federal Home Loan Bank (FHLB) and Federal Reserve Bank Stock	48,295	9,350	7,427
Purchase of FHLB and Federal Reserve Bank Stock	(42,680)	(28,857)	(7,510)
Purchase of VISA Class B stock	(6,180)	0	0
Redemption of bank owned life insurance	3,609	0	0
Purchase of bank owned life insurance	(30,000)	(40,000)	0
Net cash from bank acquisitions	23,825	235,546	32,927
Additions to bank premises and equipment	(5,710)	(6,054)	(9,091)
Net cash used in investing activities	(245,576)	(511,785)	(170,901)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase in deposits	333,049	27,320	240,086
Net increase in federal funds purchased and repurchase agreements	11,892	32,196	16,707
Net increase (decrease) in FHLB borrowings	(204,000)	415,000	(80,000)
Early redemption of FHLB borrowings	0	(50,000)	0
Stock based employee benefit plans	(55)	(1,161)	127
Issuance of common stock, net of related expense	55,641	0	0
Dividends paid	0	0	0
Net cash provided by financing activities	196,527	423,355	176,920
Net increase (decrease) in cash and cash equivalents	(140)	(26,423)	35,528
Cash and cash equivalents at beginning of year	109,644	136,067	100,539
Cash and cash equivalents at end of year	109,504	109,644	136,067
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	15,125	7,855	6,636
Cash paid during the period for income taxes	400	703	575
Supplemental disclosure of non cash investing activities:
Transfer from loans to other real estate owned	1,774	3,009	4,946
Transfer from bank premises to other real estate owned	$ 1,212	$ 7,708	$ 309

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Paid-in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss), Net [Member]
BEGINNING BALANCE at Dec. 31, 2014	$ 312,651	$ 3,300	$ 379,249	$ (65,000)	$ (71)	$ (4,827)
BEGINNING BALANCE, Shares at Dec. 31, 2014		33,137
Comprehensive income	20,755	$ 0	0	22,141	0	(1,386)
Stock based compensation expense	2,859	0	2,859	0	0	0
Common stock issued for stock based employee benefit plans	15	$ 0	17	0	(2)	0
Common stock issued for stock based employee benefit plans, shares		124
Issuance of common stock, pursuant to acquisition	17,172	$ 109	17,063	0	0	0
Issuance of common stock, pursuant to acquisition, shares		1,090
Other	1	$ 26	(26)	1	0	0
Other, shares		0
ENDING BALANCE at Dec. 31, 2015	353,453	$ 3,435	399,162	(42,858)	(73)	(6,213)
ENDING BALANCE, Shares at Dec. 31, 2015		34,351
Comprehensive income	27,902	$ 0	0	29,202	0	(1,300)
Stock based compensation expense	4,154	0	4,154	0	0	0
Common stock issued for stock based employee benefit plans	(1,161)	$ 0	2	0	(1,163)	0
Common stock issued for stock based employee benefit plans, shares		87
Common stock issued for stock options	134	$ 1	133	0	0	0
Common stock issued for stock options, shares		12
Issuance of common stock, pursuant to acquisition	50,913	$ 329	50,584	0	0	0
Issuance of common stock, pursuant to acquisition, shares		3,291
Other	2	$ 37	(34)	(1)	0	0
Other, shares		281
ENDING BALANCE at Dec. 31, 2016	435,397	$ 3,802	454,001	(13,657)	(1,236)	(7,513)
ENDING BALANCE, Shares at Dec. 31, 2016		38,022
Comprehensive income	46,868	$ 0	0	42,865	0	4,003
Reclassification of disproportionate tax effects upon adoption of new accounting pronouncement	0	0	0	706	0	(706)
Stock based compensation expense	5,267	0	5,267	0	0	0
Common stock issued for stock based employee benefit plans	(1,138)	$ 0	(15)	0	(1,123)	0
Common stock issued for stock based employee benefit plans, shares		61
Common stock issued for stock options	1,082	$ 16	1,066	0	0	0
Common stock issued for stock options, shares		91
Issuance of common stock, net of related expenses	55,641	$ 270	55,371	0	0	0
Issuance of common stock, net of related expenses, shares		2,703
Issuance of common stock, pursuant to acquisition	146,547	$ 605	145,942	0	0	0
Issuance of common stock, pursuant to acquisition, shares		6,041
ENDING BALANCE at Dec. 31, 2017	$ 689,664	$ 4,693	$ 661,632	$ 29,914	$ (2,359)	$ (4,216)
ENDING BALANCE, Shares at Dec. 31, 2017		46,918

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Significant Accounting Policies	Note A - Significant Accounting Policies General: The consolidated financial statements include the accounts of Seacoast and all its majority-owned subsidiaries but exclude trusts created for the issuance of trust preferred securities. In consolidation, all significant intercompany accounts and transactions are eliminated. The accounting and reporting policies of the Company are in accordance with accounting principles generally accepted in the United States of America, and they conform to general practices within the applicable industries. Certain reclassifications have been made to prior period amounts to conform to the current period presentation. The reclassifications had no impact to net income or retained earnings. Time deposits with other banks: Realized gains and losses, including other than temporary impairments, are included in noninterest income as investment securities gains (losses). Interest and dividends on securities, including amortization of premiums and accretion of discounts, is recognized in interest income on an accrual basis using the interest method. The Company anticipates prepayments of principal in the calculation of the effective yield for collateralized mortgage obligations and mortgage backed securities by obtaining estimates of prepayments from independent third parties. The adjusted cost of each specific security sold is used to compute realized gains or losses on the sale of securities on a trade date basis. On a quarterly basis, the Company makes an assessment to determine whether there have been any events or economic circumstances to indicate that a security is impaired on an other-than-temporary basis. Management considers many factors including the length of time the security has had a fair value less than the cost basis; recent events specific to the issuer or industry; and for debt securities, external credit ratings and recent downgrades. Management also assesses whether it intends to sell, or it is more likely than not that it will be required to sell, a security in an unrealized loss position before recovery of its amortized cost basis. Securities on which there is an unrealized loss that is deemed to be other-than temporary are written down to fair value with the write-down recorded as a realized loss. In 2014, Seacoast transferred securities into held to maturity which had previously been classified as available for sale. The unrealized loss at the date of transfer was reported as a component of shareholders’ equity and is amortized over the remaining life as an adjustment of yield using the interest method. Seacoast Bank is a member of the Federal Home Loan Bank (“FHLB”) system. Members are required to own a certain amount of FHLB stock based on the level of borrowings and other factors, and may invest in additional amounts. FHLB stock is carried at cost, and periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are reported as income. · Loans held for sale · Loans originated by Seacoast and held for investment · Loans purchased by Seacoast, which are considered purchased unimpaired (“PUL), and held for investment · Loans purchased by Seacoast, which are considered purchased credit impaired (“PCI”) Loans that are held for sale are carried as held for sale based on management’s intent to sell the loans, either as part of a core business strategy or related to a risk mitigation strategy. Loans held for sale and any related unfunded lending commitments are recorded at fair value, if elected, or the lower of cost (which is the carrying amount net of deferred fees and costs and applicable allowance for loan losses and reserve for unfunded lending commitments) or fair market value less costs to sell. Adjustments to reflect unrealized gains and losses resulting from changes in fair value and realized gains and losses upon ultimate sale of the loans are classified as noninterest income in the Consolidated Statements of Income. At the time of the transfer to loans held for sale, if the fair market value is less than cost, the difference is recorded as additional provision for credit losses in the results of operations. Fair market value is determined based on quoted market prices for the same or similar loans, outstanding investor commitments or discounted cash flow analyses using market assumptions. Fair market value for substantially all the loans in loans held for sale was obtained by reference to prices for the same or similar loans from recent transactions. Fair market value changes occur due to changes in interest rates, the borrower’s credit, the secondary loan market and the market for a borrower’s debt. Individual loans or pools of loans are transferred from the loan portfolio to loans held for sale when the intent to hold the loans has changed and there is a plan to sell the loans within a reasonable period of time. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are considered held for investment. Loans originated by Seacoast and held for investment are recognized at the principal amount outstanding, net of unearned income and amounts charged off. Unearned income includes discounts, premiums and deferred loan origination fees reduced by loan origination costs. Unearned income on loans is amortized to interest income over the life of the related loan using the effective interest rate method. Interest income is recognized on an accrual basis. As a part of business acquisitions, the Company acquires loans which are recorded at fair value on the acquisition date. Accordingly, the associated allowance for credit losses related to these loans is not carried over at the acquisition date. Any losses after acquisition are recognized through the allowance for loan losses. These loans fall into two groups: purchased unimpaired loans (“PUL”) and purchased credit-impaired loans (“PCI”). PULs demonstrate no evidence of significant credit deterioration and there is an expectation that all contractual payments will be made. The Company determines fair value by estimating the amount and timing of expected future cash flows and assigning a discount or premium to each loan. The difference between the expected cash flows and the amount paid is recorded as interest income over the remaining life of the loan. PCI loans demonstrate evidence of credit deterioration since origination and the risk that all contractual payments will not be made. The Company estimates fair value by estimating the amount of loan principal and interest cash flows expected to be collected, incorporating assumptions regarding default rates, loss severities, the amounts and timing of prepayments and other factors that are reflective of current market conditions on a quarterly basis. Probable decreases in expected loan principal cash flows trigger the recognition of impairment, which is then measured as the present value of the expected principal loss plus any related foregone interest cash flows discounted at the loan’s effective interest rate. Impairments that occur after the acquisition date are recognized through the provision for loan losses. Probable and significant increases in expected principal cash flows would first reverse any previously recorded allowance for loan losses; any remaining increases are recognized prospectively as interest income. The impacts of (i) prepayments, (ii) changes in variable interest rates, and (iii) any other changes in the timing of expected cash flows are recognized prospectively as adjustments to interest income. Disposals of loans, which may include sales of loans, receipt of payments in full by the borrower, or foreclosure, result in removal of the loan from the purchased credit impaired portfolio. In contrast, PULs are evaluated using the same procedures as used for the Company’s non-purchased loan portfolio. Under certain scenarios, the Company will grant modifications to a loan when a borrower is experiencing financial difficulties. Such modifications allow the Company to minimize the risk of loss on the loan and maximize future cash flows received from the borrower. Such modifications are referred to as troubled debt restructured (TDR) loans. TDRs are considered impaired and placed in nonaccrual status. If borrowers perform pursuant to the modified loan terms for at least six months and the remaining loan balances are considered collectible, the loans are returned to accrual status. The Company reviews all loans for impairment on a periodic basis. A loan is considered to be impaired when based on current information, it is probable the Company will not receive all amounts due in accordance with the contractual terms of a loan agreement. The fair value is measured based on either the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s observable market price or the fair value of the collateral if the loan is collateral dependent. When the ultimate collectability of the principal balance of an impaired loan is in doubt, all cash receipts are applied to principal. Once the recorded principal balance has been reduced to zero, future cash receipts are applied to interest income, to the extent any interest has been forgone, and then they are recorded as recoveries of any amounts previously charged off. The accrual of interest is generally discontinued on loans, except consumer loans, that become 90 120 Loan Commitments and letters of credit: Fees received for providing loan commitments and letters of credit that may result in loans are typically deferred and amortized to interest income over the life of the related loan, beginning with the initial borrowing. Fees on commitments and letters of credit are amortized to noninterest income as banking fees and commissions on a straight-line basis over the commitment period when funding is not expected. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Depending on the nature of the asset or liability, the Company uses various valuation techniques and assumptions when estimating fair value. The Company applies the following fair value hierarchy: Level 1 – Assets or liabilities for which the identical item is traded on an active exchange, such as publicly-traded instruments or futures contracts. Level 2 – Assets and liabilities valued based on observable market data for similar instruments. Level 3 – Assets and liabilities for which significant valuation assumptions are not readily observable in the market; instruments valued based on the best available data, some of which is internally-developed, and considers risk premiums that a market participant would require. When determining the fair value measurements for assets and liabilities required or permitted to be recorded at and/or marked to fair value, the Company considers the principal market in which it would transact and considers assumptions that market participants would use when pricing the asset or liability. When possible, the Company looks to active and observable markets to price identical assets or liabilities. When identical assets and liabilities are not traded in active markets, the Company looks to market observable data for similar assets and liabilities. Nevertheless, certain assets and liabilities are not actively traded in observable markets and the Company must use alternative valuation techniques to derive a fair value measurement. OREO may also include bank premises no longer utilized in the course of our business (closed branches) that are initially recorded at the lower of carrying value or fair value, less costs to sell. If fair value of the premises is less than amortized book value, a write down is recorded through noninterest expense. Costs to operate the facility are expensed. 25 40 5 25 3 12 The Company recognizes CDIs that result from either whole bank acquisitions or branch acquisitions. They are initially measured at fair value and then amortized over periods ranging from six to eight years on a straight line basis. The Company evaluates CDIs for impairment annually in the fourth quarter, or more often if circumstances arise that may indicate risk of impairment. If impaired, the CDI is written down with a corresponding impact to noninterest expense. The allowance for loan losses and reserve for unfunded lending commitments is maintained at a level the Company believes is adequate to absorb probable losses incurred in the loan portfolio and unfunded lending commitments as of the date of the consolidated financial statements. The Company employs a variety of modeling and estimation tools in developing the appropriate allowance for loan losses and reserve for unfunded lending commitments. The allowance for loan losses and reserve for unfunded lending commitments consists of formula-based components for commercial and consumer loans, allowance for impaired commercial loans and allowance related to additional factors that are believed indicative of current trends and business cycle issues. If necessary, a specific allowance is established for individually evaluated impaired loans. The specific allowance established for these loans is based on a thorough analysis of the most probable source of repayment, including the present value of the loan’s expected future cash flows, the loan’s estimated market value, or the estimated fair value of the underlying collateral depending on the most likely source of repayment. General allowances are established for loans grouped into pools based on similar characteristics. In this process, general allowance factors are based on an analysis of historical charge-off experience, portfolio trends, regional and national economic conditions, and expected loss given default derived from the Company’s internal risk rating process. The Company monitors qualitative and quantitative trends in the loan portfolio, including changes in the levels of past due, criticized and nonperforming loans. The distribution of the allowance for loan losses and reserve for unfunded lending commitments between the various components does not diminish the fact that the entire allowance for loan losses and reserve for unfunded lending commitments is available to absorb credit losses in the loan portfolio. The principal focus is, therefore, on the adequacy of the total allowance for loan losses and reserve for unfunded lending commitments. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Company’s bank subsidiary’s allowance for loan losses and reserve for unfunded lending commitments. These agencies may require such subsidiary to recognize changes to the allowance for loan losses and reserve for unfunded lending commitments based on their judgments about information available to them at the time of their examination. On December 22, 2017, the Tax Cuts and Jobs Act (the “Tax Reform Act”) was signed into law. Some of the most significant impacts included a decrease in the highest marginal corporate tax, from 35 21 80 30 8.6 In February 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-02, which permits companies to reclassify the disproportionate tax effects in accumulated other comprehensive income (“AOCI”), caused by the Tax Reform Act, to retained earnings. The Company early adopted ASU 2018-02 in 2017, and elected to reclassify the income tax effects of the Tax Reform Act, totaling $ 0.7 Earnings per Share:

Recently Issued Accounting Stan

Recently Issued Accounting Standards, Not Adopted at December 31, 2017	12 Months Ended
	Dec. 31, 2017
Accounting Changes and Error Corrections [Abstract]
Recently Issued Accounting Standards	Note B - Recently Issued Accounting Standards, Not Adopted at December 31, 2017 The following provides a brief description of accounting standards that have been issued but are not yet adopted that could have a material effect on the Company's financial statements: ASU 2014-09, Revenue from Contracts with Customers (Topic 606) Description In May 2014, the FASB amended existing guidance related to revenue from contracts with customers. This amendment supersedes and replaces nearly all existing revenue recognition guidance, including industry specific guidance, establishes a new control based revenue recognition model, changes the basis for deciding when revenue is recognized over time or at a point in time, provides new and more detailed guidance on specific topics and expands and improves disclosures about revenue. In addition, this amendment specifies the accounting for some costs to obtain or fulfill a contract with a customer. Date of Adoption This amendment is effective for public business entities for reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Early adoption is permitted only as of annual reporting periods after December 15, 2016, including interim reporting periods within that period. Effect on the Consolidated Financial Statements The Company has applied the modified retrospective approach in adopting this guidance effective January 1, 2018. Noninterest income items in the scope of the new guidance include service charges on deposits, trust fees, brokerage commissions and fees and interchange income. Adoption had no material impact on the Company’s consolidated financial statements. ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities Description In January 2016, the FASB amended existing guidance that requires equity investments (except those accounted for under the equity method of accounting, or those that result in consolidation of the investee) to be measured at fair value with changes in the fair value recognized in net income. It requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes. It requires separate presentation of financial assets and liabilities by measurement category and form of financial asset (i.e. securities or loans and receivables). It eliminates the requirement for public business entities to disclose methods and significant assumptions used to estimate fair value that is required to be disclosed for financial instruments measured at amortized cost. Date of Adoption This amendment is effective for public business entities for reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The new guidance permits early adoption of the own credit provision. Effect on the Consolidated Financial Statements Adoption of the guidance on January 1, 2018 had no material impact on the Company’s consolidated financial statements. ASU 2016-02, Leases (Topic 842) Description In February 2016, the FASB amended existing guidance that requires lessees recognize the following for all leases (with the exception of short-term leases) at the commencement date: 1. A lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis. 2. A right-of-use specified asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. Under the new guidance, lessor accounting is largely unchanged. Certain targeted improvements were made to align lessor accounting with the lessee accounting model and Topic 606, Revenue from Contracts with Customers. Date of Adoption This amendment is effective for public business entities for reporting periods beginning after December 15, 2018, including interim periods within that reporting period. Early adoption is permitted. Effect on the Consolidated Financial Statements The Company is in the process of evaluating the impact of this pronouncement and expects to adopt it effective January 1, 2019. ASU 2016-13, Financial Instruments –Credit Losses (Topic 326) Description In June 2016, FASB issued guidance to replace the incurred loss model with an expected loss model, which is referred to as the current expected credit loss (CECL) model. The CECL model is applicable to the measurement of credit losses on financial assets measured at amortized cost, including loan receivables and held to maturity debt securities. It also applies to off-balance sheet credit exposures not accounted for as insurance (i.e. loan commitments, standby letters of credit, financial guarantees and other similar instruments). Date of Adoption This amendment is effective for public business entities for reporting periods beginning after December 15, 2019, including interim periods within that reporting period. Early adoption is permitted only as of annual reporting periods after December 15, 2018, including interim reporting periods within that period. Effect on the Consolidated Financial Statements The Company has formed a transition oversight committee which is currently in the process of evaluating both potential CECL models and the technology needs to support the models. The Company expects a one-time cumulative adjustment to the allowance for loan losses beginning in the first period of adoption. However, the size of the impact has not yet been determined. The Company will adopt effective January 1, 2020. ASU 2016-15, Statement of Cash Flows (Topic 320): Classification of Certain Cash Receipts and Cash Payments Description In August 2016, the FASB issued this ASU to address the diversity in how certain cash receipts and cash payments are presented and classified in the statement of cash flows, including debt prepayment or debt extinguishment costs, contingent consideration payments made soon after a business combination, proceeds from the settlements of insurance claims, and proceeds from the settlements of BOLI policies. Date of Adoption This amendment is effective for public business entities for reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Early adoption is permitted. Effect on the Consolidated Financial Statements Adoption of the guidance on January 1, 2018 had no material impact on the Company’s consolidated financial statements. ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash Description In November 2016, the FASB amended existing guidance to require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning of period and end of period total amounts shown on the statement of cash flows. Date of Adoption This amendment is effective for public business entities for reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Early adoption is permitted. Effect on the Consolidated Financial Statements Adoption of the guidance on January 1, 2018 had no material impact on the Company’s consolidated financial statements. ASU 2017-04, Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Description In January 2017, the FASB amended the existing guidance to simplify the goodwill impairment measurement test by eliminating Step 2. The amendment requires the Company to perform the goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount and recognizing an impairment charge for the amount by which the carrying amount exceeds the fair value. Additionally, an entity should consider the tax effects from any tax deductible goodwill on the carrying amount when measuring the impairment loss. Date of Adoption This amendment is effective for public business entities for reporting periods beginning after December 15, 2019, including interim periods within that reporting period. Early adoption is permitted on annual goodwill impairment tests performed after January 1, 2017. Effect on the Consolidated Financial Statements The impact to the consolidated financial statements from the adoption of this pronouncement is not expected to be material. ASU 2017-01, Business Combinations(Topic 805): Clarifying the Definition of a Business Description In January 2017, the FASB amended existing guidance to clarify the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions of assets or businesses. The amendments provide a screen to determine when a set of assets and activities (collectively referred to as a “set”) is not a business. The screen requires that when substantially all of the fair value of the group assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. If the screen is not met, the amendments (1) require that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create output and (2) remove the evaluation of whether a market participant could replace missing elements. Date of adoption The amendments are effective for public business entities for annual periods beginning after December 15, 2017, including interim periods with those periods. Effect on the Consolidated Financial Statements Adoption of the guidance on January 1, 2018 had no material impact on the Company’s consolidated financial statements. ASU 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased callable Debt Securities Description In March 2017, the FASB issued guidance which requires entities to amortize premiums on certain purchased callable debt securities to their earliest call date. The accounting for purchased callable debt securities held at a discount did not change. Amortizing the premium to the earliest call date generally aligns interest income recognition with the economics of instruments. This guidance requires a modified retrospective approach under which a cumulative adjustment will be made to retained earnings as of the beginning of the period in which it is adopted. Date of adoption The amendments are effective for public business entities for annual periods beginning after December 15, 2017, including interim periods with those periods. Effect on the Consolidated Financial Statements Adoption of the guidance on January 1, 2018 had no material impact on the Company’s consolidated financial statements. ASU 2017-09, Compensation-Stock Compensation (Topic 718):Scope of Modification Accounting Description In May 2017, the FASB provided clarification that changes to the terms of share-based awards, such as value, vesting condition or classification of the awards, should be accounting for as modifications. All disclosures about modifications that are currently required would need to be made, along with disclosure of any change (or no change) in compensation expense. Date of adoption The amendments are effective for public business entities for annual periods beginning after December 15, 2017, including interim periods with those periods. Effect on the Consolidated Financial Statements Adoption of the guidance on January 1, 2018 had no material impact on the Company’s consolidated financial statements. ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities Description In August 2017, the FASB provided guidance to improve the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements. The amendments also simplify the application of the hedge accounting guidance. Date of adoption The amendments are effective for public business entities for annual periods beginning after December 15, 2018, including interim periods with those periods. Effect on the Consolidated Financial Statements The impact to the consolidated financial statements from the adoption of this pronouncement is not expected to be material.

Cash, Dividend and Loan Restric

Cash, Dividend and Loan Restrictions	12 Months Ended
	Dec. 31, 2017
Cash, Dividend and Loan Restrictions [Abstract]
Cash, Dividend and Loan Restrictions	Note C - Cash, Dividend and Loan Restrictions In the normal course of business, the Company and Seacoast Bank enter into agreements, or are subject to regulatory agreements that result in cash, debt and dividend restrictions. A summary of the most restrictive items follows: Seacoast Bank may be required to maintain average reserve balances with the Federal Reserve Bank; the average amount of those reserve balances was $ 0.5 Under Federal Reserve regulation, Seacoast Bank is limited as to the amount it may loan to its affiliates, including the Company, unless such loans are collateralized by specified obligations. At December 31, 2017, the maximum amount available for transfer from Seacoast Bank to the Company in the form of loans approximated $ 69.9 The approval of the Office of the Comptroller of the Currency (“OCC”) is required if the total of all dividends declared by a national bank in any calendar year exceeds the bank's profits, as defined, for that year combined with its retained net profits for the preceding two calendar years. Under this restriction Seacoast Bank can distribute dividends of approximately $ 87.7

Securities

Securities	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Securities	Note D - Securities December 31, 2017 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) SECURITIES AVAILABLE FOR SALE U.S. Treasury securities and obligations of U.S. Government Sponsored Entities $ 9,475 $ 274 $ (5) $ 9,744 Mortgage-backed securities of U.S. Government Sponsored Entities 318,771 891 (3,306) 316,356 Collateralized mortgage obligations of U.S. Government Sponsored Entities 235,466 272 (4,694) 231,044 Commercial mortgage backed securities of U.S. Government Sponsored Entities 16,210 165 (34) 16,341 Private mortgage backed securities 18,056 384 0 18,440 Private collateralized mortgage obligations 47,045 605 (285) 47,365 Collateralized loan obligations 263,579 798 (68) 264,309 Obligations of state and political subdivisions 45,118 813 (70) 45,861 Corporate and other debt securities 6,500 0 (156) 6,344 $ 960,220 $ 4,202 $ (8,618) $ 955,804 SECURITIES HELD TO MATURITY Mortgage-backed securities of U.S. Government Sponsored Entities $ 172,261 $ 746 $ (1,392) $ 171,615 Collateralized mortgage obligations of U.S. Government Sponsored Entities 181,280 56 (2,767) 178,569 Commercial mortgage backed securities of U.S. Government Sponsored Entities 17,462 705 0 18,167 Collateralized loan obligations 40,523 303 0 40,826 Private mortgage backed securities 5,337 9 (53) 5,293 $ 416,863 $ 1,819 $ (4,212) $ 414,470 December 31, 2016 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) SECURITIES AVAILABLE FOR SALE U.S. Treasury securities and obligations of U.S. Government Sponsored Entities $ 12,073 $ 255 $ 0 $ 12,328 Mortgage-backed securities of U.S. Government Sponsored Entities 287,726 585 (4,823) 283,488 Collateralized mortgage obligations of U.S. Government Sponsored Entities 238,805 314 (5,065) 234,054 Commercial mortgage backed securities of U.S. Government Sponsored Entities 22,351 222 (28) 22,545 Private mortgage backed securities 32,780 0 (791) 31,989 Private collateralized mortgage obligations 67,542 563 (816) 67,289 Collateralized loan obligations 124,716 838 (665) 124,889 Obligations of state and political subdivisions 63,161 622 (895) 62,888 Corporate and other debt securities 74,121 257 (517) 73,861 Private commercial mortgage backed securities 37,534 111 (473) 37,172 $ 960,809 $ 3,767 $ (14,073) $ 950,503 SECURITIES HELD TO MATURITY Mortgage-backed securities of U.S. Government Sponsored Entities $ 159,941 $ 704 $ (1,243) $ 159,402 Collateralized mortgage obligations of U.S. Government Sponsored Entities 147,208 386 (2,630) 144,964 Commercial mortgage backed securities of U.S. Government Sponsored Entities 17,375 233 (74) 17,534 Collateralized loan obligations 41,547 430 (314) 41,663 Private mortgage backed securities 6,427 0 (109) 6,318 $ 372,498 $ 1,753 $ (4,370) $ 369,881 Proceeds from sales of securities during 2017 were $ 235.6 1.6 1.5 40.1 0.5 0.1 60.3 0.7 0.5 Securities at December 31, 2017 with a fair value of $ 169.0 216.1 Held to Maturity Available for Sale Amortized Fair Amortized Fair Cost Value Cost Value (In thousands) Due in less than one year $ 0 $ 0 $ 6,248 $ 6,473 Due after one year through five years 3,600 3,607 42,448 42,616 Due after five years through ten years 36,923 37,219 256,306 257,449 Due after ten years 0 0 13,170 13,376 40,523 40,826 318,172 319,914 Mortgage-backed securities of U.S. Government Sponsored Entities 172,261 171,616 318,771 316,356 Collateralized mortgage obligations of U.S. Government Sponsored Entities 181,279 178,567 235,466 231,044 Commercial mortgage backed securities of U.S. Government Sponsored Entities 17,463 18,168 16,210 16,341 Private mortgage-backed securities 0 0 18,056 18,440 Private collateralized mortgage obligations 5,337 5,293 47,045 47,365 Corporate and other debt securities 0 0 6,500 6,344 $ 416,863 $ 414,470 $ 960,220 $ 955,804 The estimated fair value of a security is determined based on market quotations when available or, if not available, by using quoted market prices for similar securities, pricing models or discounted cash flows analyses, using observable market data where available. December 31, 2017 Less than 12 months 12 months or longer Total Fair Unrealized Fair Unrealized Fair Unrealized Value Losses Value Losses Value Losses (In thousands) U.S. Treasury securities and obligations of U.S. Government Sponsored Entities $ 1,107 $ (5) $ 0 $ 0 $ 1,107 $ (5) Mortgage-backed securities of U.S. Government Sponsored Entities 123,195 (515) 213,590 (4,183) 336,785 (4,698) Collateralized mortgage obligations of U.S. Government Sponsored Entities 176,452 (1,507) 199,086 (5,955) 375,538 (7,462) Commercial mortgage backed securities of U.S. Government Sponsored Entities 5,076 (25) 1,049 (9) 6,125 (34) Private mortgage backed securities 0 0 0 0 0 0 Private collateralized mortgage obligations 0 0 20,744 (338) 20,744 (338) Collateralized loan obligations 14,933 (68) 0 0 14,933 (68) Obligations of state and political subdivisions 5,414 (14) 5,864 (56) 11,278 (70) Corporate and other debt securities 6,500 (156) 0 0 6,500 (156) Total temporarily impaired securities $ 332,677 $ (2,290) $ 440,333 $ (10,541) $ 773,010 $ (12,831) December 31, 2016 Less than 12 months 12 months or longer Total Fair Unrealized Fair Unrealized Fair Unrealized Value Losses Value Losses Value Losses (In thousands) Mortgage-backed securities of U.S. Government Sponsored Entities $ 327,759 $ (5,991) $ 5,387 $ (75) $ 333,146 $ (6,066) Collateralized mortgage obligations of U.S. Government Sponsored Entities 234,175 (5,599) 58,912 (2,096) 293,087 (7,695) Commercial mortgage backed securities of U.S. Government Sponsored Entities 7,934 (102) 0 0 7,934 (102) Private mortgage backed securities 0 0 36,848 (900) 36,848 (900) Private collateralized mortgage obligations 1,460 0 38,417 (816) 39,877 (816) Collateralized loan obligations 8,152 (41) 51,694 (938) 59,846 (979) Obligations of state and political subdivisions 39,321 (895) 0 0 39,321 (895) Corporate and other debt securities 33,008 (517) 0 0 33,008 (517) Private commercial mortgage backed securities 12,667 (306) 7,139 (167) 19,806 (473) Total temporarily impaired securities $ 664,476 $ (13,451) $ 198,397 $ (4,992) $ 862,873 $ (18,443) The two tables above include securities held to maturity that were transferred from available for sale into held to maturity. In 2014, approximately $ 158.8 3.1 1.2 22.9 22.8 0.2 0.4 15.3 0.4 At December 31, 2017, the Company had $ 12.2 718.4 At December 31, 2017, approximately $ 0.3 20.8 As of December 31, 2017 the Company does not intend to sell securities that are in an unrealized loss position and it is not more likely than not that the Company will be required to sell these securities before recovery of the amortized cost basis. Therefore, management does not consider any investment to be other-than-temporarily impaired at December 31, 2017. Included in other assets is $ 32.5 The Company acquired 200,000 6.2 15.2 The Company also holds 11,330 1.6483 18,675

Loans

Loans	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Loans	Note E - Loans Seacoast accounts for a loan depending on the strategy for the loan and on the credit impaired status of the loan upon acquisition. Loans are accounted for using the following categories: · Loans and leases held for sale · Loans and leases originated by Seacoast and held for investment · Loans and leases purchased by Seacoast, which are considered purchased unimpaired (“PUL”), and held for investment · Loans and leases purchased by Seacoast, which are considered purchased credit impaired (“PCI”) Refer to Note A for further discussion on how the categories above are defined. Loans are also categorized based on the customer and use type of the credit extended. The following outlines the categories used: · Construction and Land Development Loans · Commercial Real Estate Loans · Residential Real Estate Loans · Commercial and Financial Loans · Consumer Loans The following table outlines net loans balances by category as of: December 31, 2017 Portfolio Loans PCI Loans PULs Total (In thousands) Construction and land development $ 215,315 $ 1,121 $ 126,689 $ 343,125 Commercial real estate 1,170,618 9,776 459,598 1,639,992 Residential real estate 845,420 5,626 187,764 1,038,810 Commercial and financial (2) 512,430 894 92,690 606,014 Consumer 178,826 0 10,610 189,436 NET LOAN BALANCES (1) $ 2,922,609 $ 17,417 $ 877,351 $ 3,817,377 December 31, 2016 Portfolio Loans PCI Loans PULs Total (In thousands) Construction and land development $ 137,480 $ 114 $ 22,522 $ 160,116 Commercial real estate 1,041,915 11,257 304,420 1,357,592 Residential real estate 784,290 684 51,813 836,787 Commercial and financial (2) 308,731 941 60,917 370,589 Consumer 153,434 0 1,018 154,452 NET LOAN BALANCES (1) $ 2,425,850 $ 12,996 $ 440,690 $ 2,879,536 (1) Net loan balances at December 31, 2017 and 2016 include deferred costs of $ 11.5 10.6 (2) Commercial and financial includes equipment lease financing of $ 30.3 0 Loan accrual status is a primary qualitative credit factor monitored by the Company’s Credit Risk Management when determining the allowance for loan and lease losses. As a loan remains delinquent, the likelihood increases that a borrower is either unable or unwilling to repay. Loans are moved to nonaccrual status when they become 90 days past due, have been evaluated for impairment and have been deemed impaired. The following table presents the balances outstanding status by class of loans as of: Accruing Accruing Accruing Greater Total 30-59 Days 60-89 Days Than Financing December 31, 2017 (in thousands) Current Past Due Past Due 90 Days Nonaccrual Receivables Portfolio Loans Construction and land development $ 215,077 $ 0 $ 0 $ 0 $ 238 $ 215,315 Commercial real estate 1,165,738 2,605 585 0 1,690 1,170,618 Residential real estate 836,117 812 75 0 8,416 845,420 Commercial and financial 507,501 2,776 26 0 2,127 512,430 Consumer 178,676 52 0 0 98 178,826 Total Portfolio Loans 2,903,109 6,245 686 0 12,569 2,922,609 Purchased Unimpaired Loans Construction and land development 126,655 34 0 0 0 126,689 Commercial real estate 457,899 979 0 0 720 459,598 Residential real estate 186,549 128 87 0 1,000 187,764 Commercial and financial 92,315 54 0 0 321 92,690 Consumer 10,610 0 0 0 0 10,610 Total Purchased Unimpaired Loans 874,028 1,195 87 0 2,041 877,351 Purchased Credit Impaired Loans Construction and land development 1,121 0 0 0 0 1,121 Commercial real estate 9,352 0 0 0 424 9,776 Residential real estate 544 642 0 0 4,440 5,626 Commercial and financial 844 0 0 0 50 894 Consumer 0 0 0 0 0 0 Total Purchased Credit Impaired Loans 11,861 642 0 0 4,914 17,417 Total Loans $ 3,788,998 $ 8,082 $ 773 $ 0 $ 19,524 $ 3,817,377 Accruing Accruing Accruing Greater Total 30-59 Days 60-89 Days Than Financing December 31, 2016 (in thousands) Current Past Due Past Due 90 Days Nonaccrual Receivables Portfolio Loans Construction and land development $ 137,042 $ 0 $ 0 $ 0 $ 438 $ 137,480 Commercial real estate 1,039,882 78 171 0 1,784 1,041,915 Residential real estate 773,877 1,570 261 0 8,582 784,290 Commercial and financial 308,652 30 0 0 49 308,731 Consumer 153,176 29 59 0 170 153,434 Total Portfolio Loans 2,412,629 1,707 491 0 11,023 2,425,850 Purchased Unimpaired Loans Construction and land development 22,490 0 0 0 32 22,522 Commercial real estate 302,318 345 485 0 1,272 304,420 Residential real estate 50,398 153 0 0 1,262 51,813 Commercial and financial 60,353 39 328 0 197 60,917 Consumer 981 37 0 0 0 1,018 Total Purchased Unimpaired Loans 436,540 574 813 0 2,763 440,690 Purchased Credit Impaired Loans Construction and land development 114 0 0 0 0 114 Commercial real estate 6,972 0 0 0 4,285 11,257 Residential real estate 499 0 185 0 0 684 Commercial and financial 941 0 0 0 0 941 Consumer 0 0 0 0 0 0 Total Purchased Credit Impaired Loans 8,526 0 185 0 4,285 12,996 Total Loans $ 2,857,695 $ 2,281 $ 1,489 $ 0 $ 18,071 $ 2,879,536 The reduction in interest income associated with loans on nonaccrual status was approximately $ 0.7 0.7 0.6 The Company’s Credit Risk Management also utilizes an internal asset classification system as a means of identifying problem and potential problem loans. The following classifications are used to categorize loans under the internal classification system: · Pass: Loans that are not problems or potential problem loans are considered to be pass-rated. · Special Mention: Loans that do not currently expose the Company to sufficient risk to warrant classification in the Substandard or Doubtful categories, but possess weaknesses that deserve management’s close attention are deemed to be Special Mention. · Substandard: Loans with the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. · Doubtful: Loans that have all the weaknesses inherent in those classified Substandard with the added characteristic that the weaknesses present make collection or liquidation in full, on the basis of currently existing facts, conditions and values, highly questionable and improbable. The principal balance of loans classified as doubtful is generally charged off. Risk grades are recalculated at least annually by the loan relationship manager. December 31, 2017 Special Pass Mention Substandard Doubtful Total (In thousands) Construction and land development $ 328,127 $ 10,414 $ 4,584 $ 0 $ 343,125 Commercial real estate 1,586,932 29,273 23,787 0 1,639,992 Residential real estate 1,023,925 4,621 10,203 61 1,038,810 Commercial and financial 593,689 3,237 8,838 250 606,014 Consumer 189,354 0 82 0 189,436 Total Loans $ 3,722,027 $ 47,545 $ 47,494 $ 311 $ 3,817,377 December 31, 2016 Special Pass Mention Substandard Doubtful Total (In thousands) Construction and land development $ 148,607 $ 5,037 $ 6,472 $ 0 $ 160,116 Commercial real estate 1,324,685 17,184 15,724 0 1,357,593 Residential real estate 811,934 1,780 23,073 0 836,787 Commercial and financial 364,241 3,949 2,399 0 370,589 Consumer 153,774 67 611 0 154,452 Total loans $ 2,803,241 $ 28,017 $ 48,279 $ 0 $ 2,879,536 Loans to directors and executive officers totaled $ 1.1 2.1 At December 31, 2017 and 2016 loans pledged as collateral for borrowings totaled $ 211 415 Concentrations of Credit The Company’s lending activity primarily occurs within the State of Florida, including Orlando, Tampa and Southeast coastal counties from Brevard County in the north to Palm Beach County in the south, as well as the counties surrounding Lake Okeechobee in the center of the state. PCI Loans PCI loans are accounted for pursuant to ASC Topic 310-30. The excess of cash flows expected to be collected over the estimated fair value is referred to as the accretable yield and is recognized in interest income over the remaining life of the loan in situations where there is a reasonable expectation about the timing and amount of cash flows expected to be collected. The difference between the contractually required payments and the cash flows expected to be collected at acquisition, considering the impact of prepayments, is referred to as the nonaccretable difference. December 31, 2017 2016 2015 (In thousands) Beginning balance $ 3,807 $ 2,610 $ 1,192 Additions 763 2,052 702 Deletions (11) (15) (357) Accretion (1,647) (1,734) (601) Reclassifications from non-accretable difference 787 894 1,674 Ending Balance $ 3,699 $ 3,807 $ 2,610 See Note S for information related to loans purchased during the periods presented. Troubled Debt Restructured Loans The Company pursues troubled debt restructures (TDR) for loans in selected cases where it expects to realize better values than may be expected through traditional collection activities. The Company has worked with retail mortgage customers, when possible, to achieve lower payment structures in an effort to avoid foreclosure. TDRs have been a part of the Company’s loss mitigation activities and can include rate reductions, payment extensions and principal deferrals. Company policy requires TDRs that are classified as nonaccrual loans after restructuring remain on nonaccrual until performance can be verified, which usually requires six months of performance under the restructured loan terms. The Company’s TDR concessions granted generally do not include forgiveness of principal balances. Loan modifications are not reported in the calendar years after modification if the loans were modified at an interest rate equal to yields of originations with comparable risk and loans are performing based on the terms of the restructuring agreements. When a loan is modified as a TDR, there is not a direct, material impact on the carrying value of the loans within the consolidated balance sheet, as principal balances generally are not forgiven. Most loans prior to modification were classified as an impaired loan and the allowance for loan losses is determined in accordance with Company policy. The following table presents accruing loans that were modified within the twelve months ending: Number of Pre- Post-Modification Valuation (In thousands) December 31, 2017: Construction and Land Development 1 $ 52 $ 46 $ 6 Residential Real Estate 1 15 15 0 Total 2 $ 67 $ 61 $ 6 December 31, 2016: Construction and Land Development 1 $ 20 $ 18 $ 2 Residential Real Estate 4 1,169 1,019 150 Total 5 $ 1,189 $ 1,037 $ 152 During the years 2017, 2016 and 2015, there were no payment defaults on loans that had been modified to a TDR within the previous twelve months. The Company considers a loan to have defaulted when it becomes 90 days or more delinquent under the modified terms, has been transferred to nonaccrual status or has been transferred to other real estate owned. A defaulted TDR is generally placed on nonaccrual status and a specific allowance for loan losses assigned in accordance with the Company’s policy. Impaired Loans Loans are considered impaired if they are 90 days or more past due, in nonaccrual status, or are TDRs. At December 31, 2017 and 2016, the Company’s recorded investment in impaired loans, excluding PCI loans, and related valuation allowance was as follows: December 31, 2017 Unpaid Related Recorded Principal Valuation (In thousands) Investment Balance Allowance Impaired Loans with No Related Allowance Recorded: Construction and land development $ 223 $ 510 $ 0 Commercial real estate 3,475 4,873 0 Residential real estate 10,272 15,063 0 Commercial and financial 19 29 0 Consumer 105 180 0 Impaired Loans with an Allowance Recorded: Construction and land development 251 264 23 Commercial real estate 4,780 4,780 195 Residential real estate 8,448 8,651 1,091 Commercial and financial 2,436 883 1,050 Consumer 282 286 43 Total Impaired Loans Construction and land development 474 774 23 Commercial real estate 8,255 9,653 195 Residential real estate 18,720 23,714 1,091 Commercial and financial 2,455 912 1,050 Consumer 387 466 43 Total $ 30,291 $ 35,519 $ 2,402 December 31, 2016 Unpaid Related Recorded Principal Valuation (In thousands) Investment Balance Allowance Impaired Loans with No Related Allowance Recorded: Construction and land development $ 226 $ 321 $ 0 Commercial real estate 3,267 4,813 0 Residential real estate 9,706 14,136 0 Commercial and financial 199 206 0 Consumer 0 0 0 Impaired Loans with an Allowance Recorded: Construction and land development 51 51 0 Commercial real estate 6,937 6,949 395 Residential real estate 12,332 12,681 2,059 Commercial and financial 0 0 0 Consumer 0 0 0 Total Impaired Loans Construction and land development 277 372 0 Commercial real estate 10,204 11,762 395 Residential real estate 22,038 26,817 2,059 Commercial and financial 199 206 0 Consumer 0 0 0 Total $ 32,718 $ 39,157 $ 2,454 Impaired loans also include TDRs where concessions have been granted to borrowers who have experienced financial difficulty. At December 31, 2017 and 2016, accruing TDRs totaled $ 15.6 17.7 Average impaired loans for the years ended December 31, 2017, 2016, and 2015 were $ 30.9 31.2 38.5 Interest payments received on impaired loans are recorded as interest income unless collection of the remaining recorded investment is doubtful at which time payments received are recorded as reductions in principal. For the years ended December 31, 2017, 2016 and 2015, the Company recorded $ 1.5 1.6 0.9 For impaired loans whose impairment is measured based on the present value of future cash flows, a total of $ 0.3 0.2 0.2

Allowance for Loan Losses

Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2017
Loans and Leases Receivable Disclosure [Abstract]
Impaired Loans and Allowance for Loan Losses	Note F - Allowance for Loan Losses Beginning Provision Charge- Recoveries TDR Ending (In thousands) December 31 , 2017 Construction and land development $ 1,219 $ (471) $ 0 $ 896 $ (2) $ 1,642 Commercial real estate 9,273 (264) (407) 747 (64) 9,285 Residential real estate 7,483 125 (569) 336 (244) 7,131 Commercial and financial 3,636 5,304 (1,869) 226 0 7,297 Consumer 1,789 954 (1,257) 290 (9) 1,767 Total $ 23,400 $ 5,648 $ (4,102) $ 2,495 $ (319) $ 27,122 December 31 , 2016 Construction and land development $ 1,151 $ (150) $ 0 $ 226 $ (8) $ 1,219 Commercial real estate 6,756 2,599 (256) 306 (132) 9,273 Residential real estate 8,057 (1,069) (205) 786 (86) 7,483 Commercial and financial 2,042 224 (439) 1,809 0 3,636 Consumer 1,122 807 (244) 109 (5) 1,789 Total $ 19,128 $ 2,411 $ (1,144) $ 3,236 $ (231) $ 23,400 December 31 , 2015 Construction and land development $ 722 $ 1,296 $ (1,271) $ 404 $ 43 $ 1,151 Commercial real estate 4,528 2,010 (263) 700 (69) 6,756 Residential real estate 9,784 (2,208) (779) 1,260 (150) 8,057 Commercial and financial 1,179 1,058 (726) 531 (6) 2,042 Consumer 794 552 (341) 117 (36) 1,122 Total $ 17,007 $ 2,708 $ (3,380) $ 3,012 $ (218) $ 19,128 As discussed in Note A, "Significant Accounting Policies," the allowance for loan losses is composed of specific allowances for certain impaired loans and general allowances grouped into loan pools based on similar characteristics. Individually Evaluated for Collectively Evaluated for Total Recorded Associated Recorded Associated Recorded Associated (In thousands) December 31, 2017 Construction and land development $ 474 $ 23 $ 341,530 $ 1,619 $ 342,004 $ 1,642 Commercial real estate 8,255 195 1,621,960 9,090 1,630,215 9,285 Residential real estate 18,720 1,091 1,014,465 6,040 1,033,185 7,131 Commercial and financial 2,455 1,050 602,666 6,247 605,121 7,297 Consumer 387 43 189,049 1,724 189,436 1,767 Total $ 30,291 $ 2,402 $ 3,769,670 $ 24,720 $ 3,799,961 $ 27,122 Individually Evaluated for Collectively Evaluated for Impairment Impairment Total Recorded Associated Recorded Associated Recorded Associated (In thousands) December 31, 2016 Construction and land development $ 277 $ 0 $ 159,839 $ 1,219 $ 160,116 $ 1,219 Commercial real estate 10,204 395 1,324,276 8,878 1,334,480 9,273 Residential real estate 22,038 2,059 813,751 5,424 835,789 7,483 Commercial and financial 199 0 368,508 3,636 368,707 3,636 Consumer 0 0 154,452 1,789 154,452 1,789 Total $ 32,718 $ 2,454 $ 2,820,826 $ 20,946 $ 2,853,544 $ 23,400 Loans collectively evaluated for impairment reported at December 31, 2017 included acquired loans that are not PCI loans. At December 31, 2017, the remaining fair value adjustments for loans acquired was $ 17.5 2.00 13.7 3.11 These amounts, which represent the remaining fair value discount of each PUL, are accreted into interest income over the remaining lives of the related loans on a level yield basis. Recapture recoveries 1.0 1.2 The table below summarizes PCI loans that were individually evaluated for impairment based on expected cash flows at December 31, 2017 and 2016. December 31, 2017 December 31, 2016 PCI Loans Individually PCI Loans Individually Recorded Associated Recorded Associated (In thousands) Construction and land development $ 1,121 $ 0 $ 114 $ 0 Commercial real estate 9,776 0 11,257 0 Residential real estate 5,626 0 684 0 Commercial and financial 894 0 941 0 Consumer 0 0 0 0 Total $ 17,417 $ 0 $ 12,996 $ 0

Bank Premises and Equipment

Bank Premises and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Bank Premises and Equipment	Note G - Bank Premises and Equipment Accumulated Net Depreciation &; Carrying Cost Amortization Value (In thousands) December 31, 2017 Premises (including land of $18,269) $ 78,255 $ (24,045) $ 54,210 Furniture and equipment 34,532 (21,859) 12,673 Total $ 112,787 $ (45,904) $ 66,883 December 31, 2016 Premises (including land of $14,773) $ 71,562 $ (22,969) $ 48,593 Furniture and equipment 30,281 (20,190) 10,091 Total $ 101,843 $ (43,159) $ 58,684

Goodwill and Acquired Intangibl

Goodwill and Acquired Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Acquired Intangible Assets	Note H - Goodwill and Acquired Intangible Assets For the Year Ended December 31, 2017 2016 2015 (In thousands) Beginning of year $ 64,649 $ 25,211 $ 25,309 Changes from business combinations 82,929 39,438 0 Other 0 0 (98) Total Goodwill $ 147,578 $ 64,649 $ 25,211 In accordance with ASC 350-20-35, the Company performs an analysis of goodwill impairment on an annual basis. Based on the analysis performed in the fourth quarter, the Company has concluded goodwill was not impaired as of December 31, 2017 and 2016. Acquired intangible assets consist of core deposit intangibles ("CDI"), which are intangible assets arising from the purchase of deposits separately or from bank acquisitions. For the Year Ended December 31, 2017 2016 2015 (In thousands) Beginning of year $ 14,572 $ 8,594 $ 7,454 Acquired CDI 7,726 8,464 2,564 Amortization expense (3,361) (2,486) (1,424) End of year $ 18,937 $ 14,572 $ 8,594 (In months) Remaining Average Amortization Period for CDI 63 64 67 December 31, 2017 December 31, 2016 Gross Gross Carrying Accumulated Carrying Accumulated Amount Amortization Amount Amortization (In thousands) Deposit base $ 26,522 $ (7,585) $ 18,796 $ (4,224) The annual amortization expense for the Company's CDI determined using the straight line method for each of five years 4 4 3.9 2.7 2.2 Mortgage servicing rights ("MSRs") retained from the sale of Small Business Administration ("SBA") guarantees totaled $ 0.2

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Borrowings	Note I - Borrowings overnight to seven days For the Year Ended December 31, 2017 2016 2015 (In thousands) Maximum amount outstanding at any month end $ 216,094 $ 236,099 $ 192,786 Weighted average interest rate at end of year 0.71 % 0.31 % 0.28 % Average amount outstanding $ 171,686 $ 187,560 $ 168,188 Weighted average interest rate during the year 0.46 % 0.26 % 0.20 % Securities sold under agreements to repurchase are accounted for as secured borrowings. For securities sold under agreements to repurchase, the Company would be obligated to provide additional collateral in the event of a significant decline in fair value of collateral pledged. December 31, 2017 2016 2015 (In thousands) Fair-Value of Pledge Securities – overnight and continuous Mortgage-backed securities and collateralized mortgage obligations of U.S. Government Sponsored Entities $ 216,094 $ 204,202 $ 172,005 Seacoast Bank had secured lines of credit of $ 1.3 211 207 1.39 0.99 2.0 14.0 16.0 7.0 1.12 On April 7, 2016, Seacoast Bank incurred an early redemption cost of $ 1.8 50.0 25.0 September 15, 2007 November 27, 2007 3.64 2.70 The Company issued $ 20.6 41.2 20.0 12.4 12.0 3-month LIBOR rate plus 175 basis points 3-month LIBOR rate plus 133 basis points 3-month LIBOR rate plus 135 basis points 3.09 2.92 2.94 The trust preferred securities have original maturities of thirty years, and may be redeemed without penalty, upon approval of the Federal Reserve or upon occurrence of certain events affecting their tax or regulatory capital treatment 619 619 372 41.2 12.4 As part of the October 1, 2014 BANKshares acquisition the Company acquired three junior subordinated debentures. Correspondingly, at December 31, 2015, the Company had $ 5.2 4.1 December 26, 2032 March 17, 2034 3-month LIBOR rate plus 325 basis points 3-month LIBOR rate plus 279 basis 4.58 4.39 5.2 February 23, 2036 three month LIBOR rate plus 139 basis points 2.84 Business Combinations 3.5 As part of the July 17, 2015 Grand Bank acquisition the Company acquired one junior subordinated debenture. Correspondingly, at December 31, 2016 the Company has $ 7.2 December 30, 2034 3-month LIBOR rate plus 198 basis points 3.67 Business Combinations 2.1 The Company has the right to defer payments of interest on the notes at any time or from time to time, in the event that under certain circumstances there is an event of default under the notes or the Company has elected to defer interest on the notes, the Company may not, with certain exceptions, declare or pay any dividends or distributions on its capital stock or purchase or acquire any of its capital stock. As of December 31, 2017, 2016 and 2015, all interest payments on trust preferred securities were current. The Company has entered into agreements to guarantee the payments of distributions on the trust preferred securities and payments of redemption of the trust preferred securities. Under these agreements, the Company also agrees, on a subordinated basis, to pay expenses and liabilities of the Trusts other than those arising under the trust preferred securities. The obligations of the Company under the junior subordinated notes, the trust agreement establishing the Trusts, the guarantees and agreements as to expenses and liabilities, in aggregate, constitute a full and conditional guarantee by the Company of the Trusts' obligations under the trust preferred securities.

Employee Benefits and Stock Com

Employee Benefits and Stock Compensation	12 Months Ended
	Dec. 31, 2017
Compensation and Retirement Disclosure [Abstract]
Employee Benefits and Stock Compensation	Note J - Employee Benefits and Stock Compensation The Company’s defined contribution plan covers substantially all employees after one year of service and includes a matching benefit for employees who can elect to defer a portion of their compensation. In addition, amounts of compensation contributed by employees are matched on a percentage basis under the plan. The defined contribution plan contributions charged to operations were $ 1.9 1.7 1.5 The Company, through its Compensation and Governance Committee of the Board of Directors (the “Compensation Committee”), offers equity compensation to employees and non-employee directors of Seacoast and Seacoast Bank in the form of various share-based awards, including stock options, restricted stock awards (“RSAs”), or restricted stock units (“RSUs”). The awards may vest over time, have certain performance based criteria, or both. Stock options are granted with an exercise price at least equal to the market price of the Company’s stock at the date of grant. The fair value of options granted is estimated on the date of grant using the Black-Scholes option-pricing model. Compensation cost is amortized on a straight-line basis over the vesting period. Vesting is determined by the Compensation Committee at the time of grant, generally over five years. The options have a maximum term of ten years. The fair value of RSAs and RSUs are estimated based on the price of the Company’s common stock on the date of grant. Compensation cost is measured straight-line for RSAs and ratably for RSUs over the vesting period of the awards and reversed for awards which are forfeited due to unfulfilled service or performance criteria. To the extent the Company has treasury shares available, stock options exercised or stock grants awarded may be issued from treasury shares. If treasury shares are insufficient, the Company can issue new shares. Vesting of share-based awards is immediately accelerated on death or disability of the recipient. The Compensation Committee may, at its discretion, accelerate vesting upon retirement (including a voluntary termination of employment at age 55) for those employees with five or more years of service with the Company, or upon the event of a change-in-control. Awards are currently granted under the Seacoast 2013 Incentive Plan (“2013 Plan”), which shareholders approved on May 23, 2013 and amended on August 26, 2015 to increase the number of authorized shares for issuance thereunder to 3,000,000 591,000 For the Year Ended December 31, (In thousands) 2017 2016 2015 Share-based compensation expense $ 5,267 $ 4,154 2,859 Income tax benefit (1,966) (1,602) (963) (In thousands) Unrecognized Weighted- Restricted stock awards $ 2,383 1.7 Restricted stock units 3,403 1.7 Stock options 1,374 2.4 Total $ 7,160 1.8 Restricted Stock Awards RSAs were granted in 2017 to various employees and vest over time, generally three years. Compensation cost of RSAs is based on the market value of the Company’s common stock at the date of grant and is recognized over the required service period on a straight-line basis. The Company’s accounting policy is to recognize forfeitures as they occur. (In thousands, except share and per share data) Restricted Weighted- Non-vested at January 1, 2017 206,952 $ 14.72 Granted 114,331 24.08 Forfeited/Cancelled (8,733) 20.76 Vested (99,574) 14.13 Non-vested at December 31, 2017 212,976 19.77 (In thousands, except share and per share data) Year Ended December 31, 2017 2016 2015 Shares granted 114,331 164,599 123,806 Weighted-average grant date fair value $ 24.08 $ 16.03 $ 15.03 Fair value of awards vested (1) $ 1,407 $ 1,981 $ 836 (1) Restricted Stock Units Certain RSUs granted in 2017 allow the grantee to earn 0 200 0 175 (In thousands, except share and per share data) Restricted Weighted- Non-vested at January 1, 2017 322,692 $ 12.61 Granted 164,268 21.61 Forfeited/Cancelled (22,113) 13.79 Vested (88,880) 10.54 Non-vested at December 31, 2017 375,967 16.96 (In thousands, except share and per share data) For the Year Ended December 31, 2017 2016 2015 Shares granted 164,268 136,188 127,128 Weighted-average grant date fair value $ 23.94 $ 13.53 $ 12.63 Fair value of awards vested (1) $ 937 $ 846 $ - (1) Stock Options For the Year Ended December 31, 2017 2016 2015 Risk-free interest rates 1.85 % 1.63 % 1.65 % Expected dividend yield 0 % 0 % 0 % Expected volatility 25.4 % 21.9 % 15.5 % Expected lives (years) 5.0 5.0 5.0 Options Weighted- Weighted- Aggregate Outstanding at January 1, 2017 778,778 $ 15.86 Granted 297,576 28.21 Exercised (91,468) 11.77 Forfeited (33,537) 96.17 Outstanding at December 31, 2017 951,349 17.29 6.86 $ 8,493 Exercisable at December 31, 2017 517,100 12.09 5.85 6,787 (In thousands, except share and per share data) For the Year Ended December 31, 2017 2016 2015 Options granted 297,576 243,391 63,650 Weighted-average grant date fair value $ 4.66 $ 3.41 $ 2.21 Intrinsic value of stock options exercised 1,143 80 - Range of Exercise Prices Options Remaining Shares Weighted $10.54 to $10.78 330,000 5.8 330,000 $ 10.67 $10.97 to $15.99 323,773 5.8 163,538 13.42 $22.65 to $28.69 297,576 9.2 23,562 22.65 Total 951,349 6.9 517,100 $ 12.09 Employee Stock Purchase Plan 300,000 95 2017 2016 2015 ESPP shares purchased 12,434 10,483 9,083 Weighted-average employee purchase price $ 22.67 $ 16.02 $ 13.99

Lease Commitments

Lease Commitments	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Lease Commitments	Note K - Lease Commitments (In thousands) 2018 $ 6,303 2019 5,935 2020 5,324 2021 4,003 2022 3,275 Thereafter 15,885 $ 40,725 Rent expense charged to operations was $ 5.8 5.3 4.1

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Note L - Income Taxes For the Year Ended December 31 2017 2016 2015 (In thousands) Current Federal $ 667 $ 653 $ 578 State 2 30 61 Deferred Federal 32,791 12,163 10,818 State 2,876 2,043 2,070 $ 36,336 $ 14,889 $ 13,527 35 For the Year Ended December 31 2017 2016 2015 (In thousands) Tax rate applied to income before income taxes $ 27,720 $ 15,431 $ 12,484 Increase (decrease) resulting from the effects of: Tax law change 8,552 0 0 Nondeductible acquisition costs 657 217 441 Tax exempt interest on loans, obligations of states and political subdivisions and bank owned life insurance (1,445) (1,215) (761) State income taxes (1,007) (726) (746) Nontaxable bargain purchase gain 0 0 (146) Tax credit investments (165) (55) 0 Stock compensation (1,027) (731) 127 Other 173 (105) (3) Federal tax provision 33,458 12,816 11,396 State tax provision 2,878 2,073 2,131 Total income tax provision $ 36,336 $ 14,889 $ 13,527 December 31, 2017 2016 (In thousands) Allowance for loan losses $ 7,187 $ 9,477 Premises and equipment 1,390 2,334 Other real estate owned 207 841 Accrued stock compensation 1,569 1,561 Federal tax loss carryforward 4,755 28,089 State tax loss carryforward 5,578 6,123 Alternative minimum tax credit carryforward 2,209 4,261 Net unrealized securities losses 1,429 4,616 Deferred compensation 2,125 3,279 Accrued interest and fee income 2,411 3,267 Other 2,248 3,748 Gross deferred tax assets 31,108 67,596 Less: Valuation allowance 0 0 Deferred tax assets net of valuation allowance 31,108 67,596 Core deposit base intangible (3,964) (3,953) Other (1,727) (2,825) Gross deferred tax liabilities (5,691) (6,778) Net deferred tax assets $ 25,417 $ 60,818 Included in the table above is the effect of certain temporary differences for which no deferred tax expense or benefit was recognized. The effect of these items is instead recorded as Accumulated Other Comprehensive Income in the shareholders' equity section of the consolidated balance sheet. In 2017 and 2016 5.6 and $ 12.1 At December 31, 2017, the Company's deferred tax assets ("DTAs") of $ 25.4 15.4 10.0 Management assesses the necessity of a valuation allowance recorded against DTAs at each reporting period. The determination of whether a valuation allowance for net DTAs is appropriate is subject to considerable judgment and requires an evaluation of all positive and negative evidence. Based on an assessment of all of the evidence, including favorable trending in asset quality and certainty regarding the amount of future taxable income that the Company forecasts, management concluded that it was more likely than not that its net DTAs will be realized based upon future taxable income. Management's confidence in the realization of projected future taxable income is based upon analysis of the Company's risk profile and its trending financial performance, including credit quality. The Company believes it can confidently and reasonably predict future results of operations that result in taxable income at sufficient levels over the future period of time that the Company has available to realize its net DTA. Management expects to realize the $25.4 million in net DTAs well in advance of the statutory carryforward period. At December 31, 2017, approximately $ 4.8 2029 2032 5.6 2029 2034 2.2 A valuation allowance could be required in future periods based on the assessment of positive and negative evidence. Management's conclusion at December 31, 2017 that it is more likely than not that the net DTAs of $25.4 million will be realized is based upon estimates of future taxable income that are supported by internal projections which consider historical performance, various internal estimates and assumptions, as well as certain external data, all of which management believes to be reasonable although inherently subject to judgment. If actual results differ significantly from the current estimates of future taxable income, even if caused by adverse macro-economic conditions, a valuation allowance may need to be recorded for some or all of the Company's DTAs. The establishment of a DTA valuation allowance could have a material adverse effect on the Company's financial condition and results of operations. The Company recognizes interest and penalties, as appropriate, as part of the provisioning for income taxes. No interest or penalties were accrued at December 31, 2017. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting, Compensation – Stock Compensation 0.8 1.1 As a result of the adoption of ASU No. 2014-01, “ Investments-Equity Method and Joint Ventures: Accounting for Investments in Qualified Affordable Housing Projects 713,000 39,000 622,000 713,000 256,000 32,000 39,000 67,000 9.3 10.0 5.2 8.3 Jurisdiction Tax Year United States of America 2014 Florida 2014 On December 22, 2017 H.R. 1, also known as the Tax Cut and Jobs Act (Act), was enacted. As a result, the Company was required to revalue its existing net DTA on that date based on the future federal corporate tax rate of 21 8.6 34.0 25.4 During the period, the Company early adopted ASU 2018-02 as discussed in Note A - Significant Accounting Policies to adjust for the historical impact of the corporate tax rate change to accumulated other comprehensive income. The adjustment relates to changes in the deferred tax asset associated with mark to market adjustments on available for sale securities. The table below reflects the balances before and after the adjustment between accumulated other comprehensive income and retained earnings: Unadjusted as of December 31, 2017 Adjustment Adjusted as of December 31, 2017 Retained Earnings $ 29,208 $ 706 $ 29,914 Accumulated Other Comprehensive Income (3,510) (706) (4,216)

Noninterest Income and Expenses

Noninterest Income and Expenses	12 Months Ended
	Dec. 31, 2017
Noninterest Income and Expenses [Abstract]
NONINTEREST INCOME AND EXPENSE	Note M - Noninterest Income and Expenses Details of noninterest income and expense is as follows: For the Year Ended December 31, 2017 2016 2015 (In thousands) Noninterest income Service charges on deposit accounts $ 10,049 $ 9,669 $ 8,563 Trust fees 3,705 3,433 3,132 Mortgage banking fees 6,449 5,864 4,252 Brokerage commissions and fees 1,352 2,044 2,132 Marine finance fees 910 673 1,152 Interchange income 10,583 9,227 7,684 Other deposit based EFT fees 465 477 397 BOLI Income 3,426 2,213 1,426 Gain on participated loan 0 0 725 Other 6,291 3,827 2,555 43,230 37,427 32,018 Securities gains, net 86 368 161 Gain on sale of VISA stock 15,153 0 0 Bargain purchase gain, net 0 0 416 TOTAL $ 58,469 $ 37,795 $ 32,595 Noninterest expense Salaries and wages $ 65,692 $ 54,096 $ 41,075 Employee benefits 11,732 9,903 9,564 Outsourced data processing costs 14,116 13,516 10,150 Telephone / data lines 2,291 2,108 1,797 Occupancy 13,290 13,122 8,744 Furniture and equipment 6,067 4,720 3,434 Marketing 4,784 3,633 4,428 Legal and professional fees 11,022 9,596 8,022 FDIC assessments 2,326 2,365 2,212 Amortization of intangibles 3,361 2,486 1,424 Asset dispositions expense 411 553 472 Net (gain)/loss on other real estate owned and repossessed assets (711) (509) 239 Early redemption cost for Federal Home Loan Bank advances 0 1,777 0 Other 15,535 13,515 12,209 TOTAL $ 149,916 $ 130,881 $ 103,770

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Shareholders' Equity	Note N - Shareholders' Equity The Company has reserved 300,000 1,000,000 175,997 32,120 Holders of common stock are entitled to one vote per share on all matters presented to shareholders as provided in the Company’s Articles of Incorporation. The Company implemented a dividend reinvestment plan during 2007, issuing no shares from treasury stock during 2017 and 2016. Minimum for Capital Adequacy Minimum To Be Well Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) SEACOAST BANKING CORP (CONSOLIDATED) At December 31, 2017: Total Capital Ratio (to risk-weighted assets) $ 619,746 14.24 % $ 348,191 ≥ 8.00 % n/a n/a Tier 1 Capital Ratio (to risk-weighted assets) 592,562 13.61 261,143 ≥ 6.00 % n/a n/a Common Equity Tier 1 Capital (to risk-weighted assets) 523,832 12.04 195,858 ≥ 4.50 % n/a n/a Tier 1 Leverage Ratio (to adjusted average assets) 592,562 10.68 221,863 ≥ 4.00 % n/a n/a At December 31, 2016: Total Capital Ratio (to risk-weighted assets) $ 432,058 13.25 % $ 260,790 ≥ 8.00 % n/a n/a Tier 1 Capital Ratio (to risk-weighted assets) 408,596 12.53 195,592 ≥ 6.00 % n/a n/a Common Equity Tier 1 Capital (to risk-weighted assets) 351,769 10.79 146,694 ≥ 4.50 % n/a n/a Tier 1 Leverage Ratio (to adjusted average assets) 408,596 9.15 178,656 ≥ 4.00 % n/a n/a SEACOAST NATIONAL BANK (A WHOLLY OWNED BANK SUBSIDIARY) At December 31, 2017: Total Capital Ratio (to risk-weighted assets) $ 565,149 13.04 % $ 346,780 ≥ 8.00 % $ 433,475 ≥ 10.00 % Tier 1 Capital Ratio (to risk-weighted assets) 537,965 12.41 260,085 ≥ 6.00 % 346,780 ≥ 8.00 % Common Equity Tier 1 Capital (to risk-weighted assets) 537,965 12.41 195,022 ≥ 4.50 % 281,759 ≥ 6.50 % Tier 1 Leverage Ratio (to adjusted average assets) 537,965 9.72 221,432 ≥ 4.00 % 276,791 ≥ 5.00 % At December 31, 2016: Total Capital Ratio (to risk-weighted assets) $ 415,147 12.75 % $ 260,491 ≥ 8.00 % $ 325,987 ≥ 10.00 % Tier 1 Capital Ratio (to risk-weighted assets) 391,685 12.03 195,368 ≥ 6.00 % 260,790 ≥ 8.00 % Common Equity Tier 1 Capital (to risk-weighted assets) 391,685 12.03 146,526 ≥ 4.50 % 211,892 ≥ 6.50 % Tier 1 Leverage Ratio (to adjusted average assets) 391,685 8.78 178,501 ≥ 4.00 % 223,320 ≥ 5.00 % (1) Excludes capital conservation buffer of 1.250% the Company is subject to, which if not exceeded may constrain dividends, equity repurchases and compensation. n/a - not applicable The Company is subject to various regulatory capital requirements administered by the federal banking agencies. Under Basel III standards adopted January 1, 2015, deferred tax assets (DTAs) were substantially restricted in regulatory capital calculations, the Common Equity Tier 1 Capital calculation was created, and new minimum adequacy and well capitalized thresholds were established. 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 must meet specific capital guidelines that involve quantitative measures of the Company's assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. The Company's capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings, and other factors. At year-end 2017 and 2016, the most recent regulatory notifications categorize the Company as well capitalized under the regulatory frame work for prompt corrective action Quantitative measures established by regulation to ensure capital adequacy require the Company to maintain minimum amounts and ratios of total, Tier 1 capital and common equity Tier 1 capital (as defined in the regulations) to risk-weighted assets (as defined) and of Tier 1 capital to average assets (as defined). Management believes, as of December 31, 2017, that the Company and Seacoast Bank meets all capital adequacy requirements to which it is subject. At December 31, 2017, the capital conservation buffer requisite the Company is subject to was 1.250%. On February 21, 2017, the Company closed on its offering of 8.9 2.7 6.2 56.7 Communities decisions regarding this offering.

(Parent Company Only) Financial

(Parent Company Only) Financial Information	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Parent Company Only Financial Information	Note O - Seacoast Banking Corporation of Florida (Parent Company Only) Financial Information December 31, 2017 2016 (In thousands) ASSETS Cash $ 1,154 $ 648 Securities purchased under agreement to resell with subsidiary bank, maturing within 30 days 33,151 12,676 Investment in subsidiaries 711,973 494,809 Other assets 21,337 1,211 $ 767,615 $ 509,344 LIABILITIES AND SHAREHOLDERS' EQUITY Subordinated debt $ 70,521 $ 70,241 Other liabilities 7,430 3,706 Shareholders' equity 689,664 435,397 $ 767,615 $ 509,344 Year Ended December 31 2017 2016 2015 (In thousands) Income Interest/other $ 2,104 $ 352 $ 115 Dividends from subsidiary Bank 0 0 0 Gain on sale of VISA stock 15,153 0 0 17,257 352 115 Interest expense 2,499 2,115 1,671 Other expenses 649 462 317 Income (loss) before income taxes and equity in undistributed income of subsidiaries 14,109 (2,225) (1,873) Income tax provision (benefit) benefit 4,938 (801) (661) Income (loss) before equity in undistributed income of subsidiaries 9,171 (1,424) (1,212) Equity in undistributed income of subsidiaries 33,694 30,626 23,353 Net income $ 42,865 $ 29,202 $ 22,141 Year Ended December 31 2017 2016 2015 (In thousands) Cash flows from operating activities Adjustments to reconcile net income to net cash provided by operating activities: Net Income $ 42,865 $ 29,202 $ 22,141 Equity in undistributed income of subsidiaries (33,694) (30,626) (23,353) Gain on sale of VISA stock (15,153) 0 0 Net (increase) decrease in other assets 1,415 (12) 10 Net increase (decrease) in other liabilities 4,005 12 (48) Net cash used in operating activities (562) (1,424) (1,250) Cash flows from investing activities Net cash paid for bank acquisition (27,862) (28,905) 0 Investment in unconsolidated subsidiary 0 (200) 0 Investment in VISA stock (6,180) 0 0 Decrease (increase) in securities purchased under agreement to resell, maturing within 30 days, net (20,475) 30,647 (5,487) Net cash provided by (used in) investment activities (54,517) 1,542 (5,487) Cash flows from financing activities Issuance of common stock, net of related expense 55,641 0 0 Subordinated debt increase 0 0 6,494 Stock based employment plans (56) 166 127 Net cash provided by financing activities 55,585 166 6,621 Net change in cash 506 284 (116) Cash at beginning of year 648 364 480 Cash at end of year $ 1,154 $ 648 $ 364 Supplemental disclosure of cash flow information: Cash paid during the period for interest $ 2,205 $ 1,824 $ 1,487

Contingent Liabilities and Comm

Contingent Liabilities and Commitments with Off-Balance Sheet Risk	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Contingent Liabilities and Commitments with Off-Balance Sheet Risk	Note P - Contingent Liabilities and Commitments with Off-Balance Sheet Risk The Company and its subsidiaries, because of the nature of their business, are at all times subject to numerous legal actions, threatened or filed. Management presently believes that none of the legal proceedings to which it is a party are likely to have a materially adverse effect on the Company’s consolidated financial condition, or operating results or cash flows. The Company's subsidiary bank is party to financial instruments with off balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit, standby letters of credit, and limited partner equity commitments. The subsidiary bank’s exposure to credit loss in the event of non-performance by the other party to the financial instrument for commitments to extend credit and standby letters of credit is represented by the contract or notional amount of those instruments. The subsidiary bank uses the same credit policies in making commitments and standby letters of credit as they do for on balance sheet instruments. Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The subsidiary bank evaluates each customer's creditworthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by the bank upon extension of credit, is based on management's credit evaluation of the counterparty. Collateral held varies but may include accounts receivable, inventory, equipment, and commercial and residential real estate. Of the $ 807.7 368.7 86.5 3.00 5.50 Standby letters of credit are conditional commitments issued by the subsidiary bank to guarantee the performance of a customer to a third party. These instruments have fixed termination dates and most end without being drawn; therefore, they do not represent a significant liquidity risk. Those guarantees are primarily issued to support public and private borrowing arrangements, including commercial paper, bond financing, and similar transactions. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. The subsidiary bank holds collateral supporting these commitments for which collateral is deemed necessary. The extent of collateral held for secured standby letters of credit at December 31, 2017 and 2016 amounted to $ 26.4 46.6 10.9 December 31, 2017 2016 (In thousands) Contract or Notional Amount Financial instruments whose contract amounts represent credit risk: Commitments to extend credit $ 807,651 $ 532,082 Standby letters of credit and financial guarantees written: Secured 12,913 10,776 Unsecured 681 554 Unfunded limited partner equity commitment 10,914 10,148

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
FAIR VALUE	Note Q - Fair Value Under ASC 820, fair value measurements for items measured at fair value on a recurring and nonrecurring basis at December 31, 2017 and December 31, 2016 included: Quoted Prices in Significant Other Significant Other Active Markets for Observable Unobservable Fair Value Identical Assets Inputs Inputs (In thousands) Measurements Level 1 Level 2 Level 3 At December 31, 2017 Available for sale securities (1) $ 955,804 $ 6,600 $ 949,204 $ 0 Loans held for sale (2) 24,306 0 24,306 0 Loans (3) 4,192 0 3,454 738 Other real estate owned (4) 7,640 0 60 7,580 At December 31, 2016 Available for sale securities (1) $ 950,503 $ 100 $ 950,403 $ 0 Loans held for sale (2) 15,332 0 15,332 0 Loans (3) 4,120 0 3,170 950 Other real estate owned (4) 9,949 0 0 9,949 (1) See Note D for further detail of fair value of individual investment categories. (2) Recurring fair value basis determined using observable market data. (3) See Note E. Nonrecurring fair value adjustments to loans identified as impaired reflect full or partial write- downs that are based on the loan’s observable market price or current appraised value of the collateral in accordance with ASC 310. (4) Fair value is measured on a nonrecurring basis in accordance with ASC 360. The fair value of impaired loans which are not troubled debt restructurings is based on recent real estate appraisals less estimated costs of sale. For residential real estate impaired loans, appraised values or internal evaluation are based on the comparative sales approach. These impaired loans are considered level 2 in the fair value hierarchy. For commercial and commercial real estate impaired loans, evaluations may use either a single valuation approach or a combination of approaches, such as comparative sales, cost and/or income approach. A significant unobservable input in the income approach is the estimated capitalization rate for a given piece of collateral. At December 31, 2017 the range of capitalization rates utilized to determine fair value of the underlying collateral averaged approximately 7.8 4.2 2.4 4.1 0.4 Fair value of available for sale securities are determined using valuation techniques for individual investments as described in Note A. When appraisals are used to determine fair value and the appraisals are based on a market approach, the fair value of OREO is classified as level 2. When the fair value of OREO is based on appraisals which require significant adjustments to market-based valuation inputs or apply an income approach based on unobservable cash flows, the fair value of OREO is classified as Level 3. Transfers between levels of the fair value hierarchy are recognized on the actual date of the event or circumstances that caused the transfer, which generally coincides with the Company's monthly and/or quarter valuation process. For loans classified as level 3 additions totaled $ 0.4 0.6 0.5 Charge-offs recognized upon loan foreclosures are generally offset by general or specific allocations of the allowance for loan losses and generally do not, and did not during the reported periods, significantly impact the Company's provision for loan losses. For OREO classified as level 3 during the twelve months ended December 31, 2017, foreclosed loans added $ 1.7 1.2 5.3 5.0 Quoted Prices in Significant Other Significant Other Active Markets for Observable Unobservable Carrying Identical Assets Inputs Inputs (In thousands) Amount Level 1 Level 2 Level 3 At December 31, 2017 Financial Assets Securities held to maturity (1) $ 416,863 $ 0 $ 414,472 $ 0 Time deposits with other banks 12,553 0 0 12,493 Loans, net 3,786,063 0 0 3,760,754 Financial Liabilities Deposits 4,592,720 0 0 4,588,515 Subordinated debt 70,521 0 61,530 0 At December 31, 2016 Financial Assets Securities held to maturity (1) $ 372,498 $ 0 $ 369,881 $ 0 Loans, net 2,852,016 0 0 2,840,993 Financial Liabilities Deposits 3,523,245 0 0 3,523,322 Subordinated debt 70,241 0 54,908 0 (1) See Note D for further detail of recurring fair value basis of individual investment categories. The short maturity of Seacoast’s assets and liabilities results in having a significant number of financial instruments whose fair value equals or closely approximates carrying value. Such financial instruments are reported in the following balance sheet captions: cash and cash equivalents, interest bearing deposits with other banks, federal funds purchased, FHLB borrowings, and securities sold under agreement to repurchase, maturing within 30 days. The following methods and assumptions were used to estimate the fair value of each class of financial instrument for which it is practicable to estimate that value at December 31, 2017 and December 31, 2016: Securities The Company reviews the prices supplied by the independent pricing service, as well as their underlying pricing methodologies, for reasonableness and to ensure such prices are aligned with traditional pricing matrices. In general, the Company does not purchase investment portfolio securities that are esoteric or that have a complicated structure. The Company’s entire portfolio consists of traditional investments, the majority of which are U.S. Treasury obligations, federal agency bullet, mortgage pass-through securities, or general obligation or revenue based municipal bonds. Pricing for such instruments is fairly generic and is easily obtained. The fair value of the collateralized loan obligations is determined from broker quotes. From time to time, the Company will validate, on a sample basis, prices supplied by brokers and the independent pricing service by comparison to prices obtained from other brokers and third-party sources or derived using internal models Loans Loans held for sale December 31, (In thousands) 2017 2016 Aggregate fair value $ 24,306 $ 15,332 Contractual balance 23,627 14,904 Excess 679 428 Deposit Liabilities

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Note R - Earnings Per Share Basic earnings per common share is computed by dividing net income available to common shareholders by the weighted average number of shares of common stock outstanding during the year. 274,000 131,000 456,000 For the Year Ended December 31 (In thousands, except per share data) 2017 2016 2015 Basic earnings per share Net Income $ 42,865 $ 29,202 $ 22,141 Total weighted average common stock outstanding 42,613 36,872 33,496 Net income per share $ 1.01 $ 0.79 $ 0.66 Diluted earnings per share Net Income $ 42,865 $ 29,202 $ 22,141 Total weighted average common stock outstanding $ 42,613 $ 36,872 $ 33,496 Add: Dilutive effect of employee restricted stock and stock options (See Note J) 737 636 248 Total weighted average diluted stock outstanding 43,350 37,508 33,744 Net income per share $ 0.99 $ 0.78 $ 0.66

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Business Combinations	Note S - Business Combinations Acquisition of Floridian Financial Group, Inc. On March 11, 2016, Seacoast completed its acquisition of Floridian Financial Group, Inc. (“Floridian”). Simultaneously, upon completion of the merger, Floridian’s wholly owned subsidiary bank, Floridian Bank, was merged with and into Seacoast Bank. Floridian, headquartered in Lake Mary, Florida, operated 10 branches in Orlando and Daytona Beach, of which several were consolidated with Seacoast locations. This acquisition added $ 417 266 337 Seacoast expects to benefit from this acquisition through solidifying its market share in the Central Florida market, expanding its customer base and leveraging operating costs through economies of scale, and positively affect the Company’s operating results. 100 (In thousands, except per share data) March 11, 2016 Floridian shares exchanged for cash $ 26,699 Number of Floridian common shares outstanding 6,222 Per share exchange ratio 0.5289 Number of shares of common stock issued 3,291 Multiplied by common stock price per share on March 11, 2016 $ 15.47 Value of common stock issued 50,913 Total purchase price $ 77,612 Business Combinations 32 Measurement March 11, 2016 Period March 11, 2016 (Initially Reported) Adjustments (As Adjusted) (in thousands) Assets: Cash $ 28,243 $ 0 $ 28,243 Investment securities 66,912 95 67,007 Loans, net 268,249 (2,112) 266,137 Fixed assets 7,801 (628) 7,173 Core deposit intangibles 3,375 0 3,375 Goodwill 29,985 1,647 31,632 Other assets 12,879 998 13,877 $ 417,444 $ 0 $ 417,444 Liabilities: Deposits $ 337,341 $ 0 $ 337,341 Other liabilities 2,492 0 2,492 $ 339,833 $ 0 $ 339,833 March 11, 2016 (In thousands) Book Balance Fair Value Loans: Single family residential real estate $ 38,304 $ 37,367 Commercial real estate 172,531 167,105 Construction/development/land 20,546 18,108 Commercial loans 39,070 37,804 Consumer and other loans 3,385 3,110 Purchased credit-impaired 6,186 2,643 Total acquired loans $ 280,022 $ 266,137 For the loans acquired we first segregated all acquired loans with specifically identified credit deficiency factor(s). The factors we considered to identify loans as Purchase Credit Impaired (“PCI”) loans were all acquired loans that were nonaccrual, 60 days or more past due, designated as Trouble Debt Restructured (“TDR”), graded “special mention” or “substandard.” These loans were then evaluated to determine estimated fair values as of the acquisition date. The table below summarizes the total contractually required principal and interest cash payments, management’s estimate of expected total cash payments and fair value of the loans as of March 11, 2016 for PCI loans. March 11, 2016 (In thousands) Contractually required principal and interest $ 8,031 Non-accretable difference (4,820) Cash flows expected to be collected 3,211 Accretable yield (568) Total purchased credit impaired loans acquired $ 2,643 Loans without specifically identified credit deficiency factors are referred to as Purchased Unimpaired Loans (“PULs”) for disclosure purposes. These loans were then evaluated to determine estimated fair values as of the acquisition date. Although no specific credit deficiencies were identifiable, we believe there is an element of risk as to whether all contractual cash flows will be eventually received. Factors that were considered included the economic environment both nationally and locally as well as the real estate market particularly in Florida. The Company believes the deposits assumed from the acquisition have an intangible value. In determining the valuation amount, deposits were analyzed based on factors such as type of deposit, deposit retention, interest rates and age of deposit relationships. Acquisition of BMO Harris Central Florida Offices, Deposits and Loans On June 3, 2016, Seacoast completed its acquisition of the Orlando banking operations of BMO Harris Bank N.A. (BMO), which included fourteen branches. The acquisition added $ 314 63 314 3.0 0.5 Seacoast expects to benefit from this acquisition through solidifying its market share in the Central Florida market, expanding its customer base and leveraging operating costs through economies of scale, and positively affecting the Company’s operating results. Business Combinations 13 15 Measurement June 3, 2016 Period June 3, 2016 (Initially Reported) Adjustments (As Adjusted) (in thousands) Assets: Cash from BMO (net of payable) $ 234,094 $ 0 $ 234,094 Loans, net 62,671 0 62,671 Fixed assets 3,715 0 3,715 Core deposit intangibles 5,223 (135) 5,088 Goodwill 7,645 163 7,808 Other assets 952 (28) 924 $ 314,300 $ 0 $ 314,300 Liabilities: Deposits $ 314,248 $ 0 $ 314,248 Other liabilities 52 0 52 $ 314,300 $ 0 $ 314,300 The table below presents information with respect to the fair value of acquired loans, as well as their Book Balance at acquisition date. June 3, 2016 (In thousands) Book Balance Fair Value Loans: Commercial real estate $ 31,564 $ 31,200 Commercial loans 32,479 31,471 Purchased credit-impaired 0 0 Total acquired loans $ 64,043 $ 62,671 At June 3, 2016, no loans acquired from BMO Harris were specifically identified with a credit deficiency factor(s). The factors we consider to identify loans as PCI loans are acquired loans that were nonaccrual, 60 days or more past due, designated as TDR, graded “special mention” or “substandard.” PULs were evaluated to determine estimated fair values as of the acquisition date. Although no specific credit deficiencies were identifiable, we believe there is an element of risk as to whether all contractual cash flows will be eventually received. Factors that were considered included the economic environment both nationally and locally as well as the real estate market particularly in Florida. The Company believes the deposits assumed from the acquisition have an intangible value. In determining the valuation amount, deposits were analyzed based on factors such as type of deposit, deposit retention, interest rates and age of deposit relationships. Acquisition of GulfShore Bancshares, Inc. On April 7, 2017, the Company completed its acquisition of GulfShore, the parent company of GulfShore Bank. Simultaneously, upon completion of the merger, GulfShore’s wholly owned subsidiary bank, GulfShore Bank, was merged with and into Seacoast Bank. GulfShore, headquartered in Tampa, Florida, operated 3 branches in Tampa and St. Petersburg. This acquisition added $ 358 251 285 As a result of this acquisition the Company expects to enhance its presence in the Tampa, Florida market, expand its customer base and leverage operating cost through economies of scale, and positively affect the Company’s operating results to the extent the Company earns more from interest earning assets than it pays in interest on its interest bearing liabilities. 100 (In thousands, except per share data) April 7, 2017 Shares exchanged for cash $ 8,034 Number of GulfShore Bancshares, Inc. common shares outstanding 5,464 Per share exchange ratio 0.4807 Number of shares of common stock issued 2,627 Multiplied by common stock price per share on April 7, 2017 $ 23.94 Value of common stock issued 62,883 Total purchase price $ 70,917 Business Combinations 37.1 Measurement April 7, 2017 Period April 7, 2017 Date of acquisition (Initially Reported) Adjustments (As Adjusted) (in thousands) Assets: Cash $ 38,267 $ 0 $ 38,267 Time deposits with other banks 17,273 0 17,273 Investment securities 21 0 21 Loans, net 250,876 0 250,876 Fixed assets 1,307 0 1,307 Other real estate owned 13 0 13 Core deposit intangibles 3,927 0 3,927 Goodwill 37,098 0 37,098 Other assets 8,867 0 8,867 $ 357,649 $ 0 $ 357,649 Liabilities: Deposits $ 285,350 $ 0 $ 285,350 Other liabilities 1,382 0 1,382 $ 286,732 $ 0 $ 286,732 The table below presents information with respect to the fair value of acquired loans, as well as their unpaid principal balance (“Book Balance”) at acquisition date. April 7, 2017 (In thousands) Book Balance Fair Value Loans: Single family residential real estate $ 101,281 $ 99,598 Commercial real estate 106,729 103,905 Construction/development/land 13,175 11,653 Commercial loans 32,137 32,247 Consumer and other loans 3,554 3,473 Purchased credit-impaired 0 0 Total acquired loans $ 256,876 $ 250,876 No loans acquired were specifically identified with credit deficiency factor(s), pursuant to ASC Topic 310-30. The factors we considered to identify loans as PCI loans were all acquired loans that were nonaccrual, 60 days or more past due, designated as TDR, graded “special mention” or “substandard.” Loans without specifically identified credit deficiency factors are referred to as PULs for disclosure purposes. These loans were then evaluated to determine estimated fair values as of the acquisition date. Although no specific credit deficiencies were identifiable, we believe there is an element of risk as to whether all contractual cash flows will be eventually received. Factors that were considered included the economic environment both nationally and locally as well as the real estate market particularly in Florida. We have applied ASC Topic 310-20 accounting treatment to the PULs. The Company believes the deposits assumed from the acquisition have an intangible value. In determining the valuation amount, deposits were analyzed based on factors such as type of deposit, deposit retention, interest rates and age of deposit relationships. Acquisition of NorthStar Banking Corporation On October 20, 2017, the Company completed its acquisition of NorthStar Banking Corporation (“NSBC”). Simultaneously, upon completion of the merger, NSBC’s wholly owned subsidiary bank, NorthStar Bank, was merged with and into Seacoast Bank. NorthStar, headquartered in Tampa, Florida, operated three branches in Tampa, of which all have been retained as Seacoast locations. This acquisition added $ 216 137 182 As a result of this acquisition the Company expects to enhance its presence in the Tampa, Florida market, expand its customer base and leverage operating cost through economies of scale, and positively affect the Company’s operating results to the extent the Company earns more from interest earning assets than it pays in interest on its interest bearing liabilities. 100 Under the terms of the definitive agreement, NSBC shareholders received, for each share of NSBC common stock, the combination of $2.40 in cash and 0.5605 shares of Seacoast common stock (based on Seacoast’s closing price of $24.92 per share on October 20, 2017) (In thousands, except per share data) October 20, 2017 Shares exchanged for cash $ 4,701 Number of NorthStar Banking Corporation Common shares outstanding 1,958 Per share exchange ratio 0.5605 Number of shares of common stock issued 1,098 Multiplied by common stock price per share on October 20, 2017 $ 24.92 Value of common stock issued 27,353 Cash paid for NorthStar Banking Corporation vested stock options 801 Total purchase price $ 32,855 Business Combinations 12.4 Date of acquisition October 20, 2017 (in thousands) Assets: Cash $ 5,485 Investment securities 56,123 Loans, net 136,832 Fixed assets 2,637 Core deposit intangibles 1,275 Goodwill 12,404 Other assets 1,522 Total assets $ 216,278 Liabilities: Deposits $ 182,443 Other liabilities 980 Total liabilities $ 183,423 The table below presents information with respect to the fair value of acquired loans, as well as their unpaid principal balance (“Book Balance”) at acquisition date. October 20, 2017 (In thousands) Book Balance Fair Value Loans: Single family residential real estate $ 15,111 $ 15,096 Commercial real estate 73,139 69,554 Construction/development/land 11,706 10,390 Commercial loans 31,200 30,854 Consumer and other loans 6,761 6,645 Purchased Credit Impaired 5,527 4,293 Total acquired loans $ 143,444 $ 136,832 For the loans acquired we first segregated all acquired loans with specifically identified credit deficiency factor(s). The factors we considered to identify loans as PCI loans were all acquired loans that were nonaccrual, 60 days or more past due, designated as TDR, graded “special mention” or “substandard.” These loans were then evaluated to determine estimated fair values as of the acquisition date. As required by generally accepted accounting principles, we are accounting for these loans pursuant to ASC Topic 310-30. The table below summarizes the total contractually required principal and interest cash payments, management’s estimate of expected total cash payments and fair value of the loans as of October 20, 2017 for purchased credit impaired loans. October 20, 2017 (In thousands) Contractually required principal and interest $ 5,596 Non-accretable difference (689) Cash flows expected to be collected 4,907 Accretable yield (614) Total purchased credit-impaired loan acquired $ 4,293 Loans without specifically identified credit deficiency factors are referred to as PULs for disclosure purposes. These loans were then evaluated to determine estimated fair values as of the acquisition date. Although no specific credit deficiencies were identifiable, we believe there is an element of risk as to whether all contractual cash flows will be eventually received. Factors that were considered included the economic environment both nationally and locally as well as the real estate market particularly in Florida. We have applied ASC Topic 310-20 accounting treatment to the PULs. The Company believes the deposits assumed from the acquisition have an intangible value. In determining the valuation amount, deposits were analyzed based on factors such as type of deposit, deposit retention, interest rates and age of deposit relationships. Acquisition of Palm Beach Community Bank On November 3, 2017, the Company completed its acquisition of Palm Beach Community Bank (“PBCB”). PBCB was merged with and into Seacoast Bank. This acquisition added $ 357 272 269 As a result of this acquisition the Company expects to enhance its presence in the Palm Beach, Florida market, expand its customer base and leverage operating cost through economies of scale, and positively affect the Company’s operating results to the extent the Company earns more from interest earning assets than it pays in interest on its interest bearing liabilities. 100 Under the terms of the definitive agreement, PBCB shareholders received, for each share of PBCB common stock, the combination of $6.26 in cash and 0.9240 shares of Seacoast common stock (based on Seacoast’s closing price of $24.31 per share on November 3, 2017). (In thousands, except per share data) November 3, 2017 Shares exchanged for cash $ 15,694 Number of Palm Beach Community Bank Common shares outstanding 2,507 Per share exchange ratio 0.9240 Number of shares of common stock issued 2,316 Multiplied by common stock price per share on November 3, 2017 $ 24.31 Value of common stock issued 56,312 Total purchase price $ 72,006 Business Combinations 33.4 Date of acquisition November 3, 2017 (In thousands) Assets: Cash $ 9,301 Investment securities 22,098 Loans, net 272,090 Fixed assets 7,641 Core deposit intangibles 2,523 Goodwill 33,428 Other assets 9,909 Total assets $ 356,990 Liabilities: Deposits $ 268,633 Other liabilities 16,351 Total liabilities $ 284,984 The table below presents information with respect to the fair value of acquired loans, as well as their Book Balance at acquisition date. November 3, 2017 (In thousands) Book Balance Fair Value Loans: Single family residential real estate $ 30,153 $ 30,990 Commercial real estate 134,705 132,654 Construction/development/land 69,686 67,425 Commercial loans 36,076 37,083 Consumer and other loans 179 172 Purchased Credit Impaired 4,768 3,766 Total acquired loans $ 275,567 $ 272,090 For the loans acquired we first segregated all acquired loans with specifically identified credit deficiency factor(s). The factors we considered to identify loans as PCI loans were all acquired loans that were nonaccrual, 60 days or more past due, designated as TDR, graded “special mention” or “substandard.” These loans were then evaluated to determine estimated fair values as of the acquisition date. As required by generally accepted accounting principles, we are accounting for these loans pursuant to ASC Topic 310-30. The table below summarizes the total contractually required principal and interest cash payments, management’s estimate of expected total cash payments and fair value of the loans as of November 3, 2017 for purchased credit impaired loans. (In thousands) November 3, 2017 Contractually required principal and interest $ 4,768 Non-accretable difference (1,002) Cash flows expected to be collected 3,766 Accretable yield 0 Total purchased credit-impaired loan acquired $ 3,766 Loans without specifically identified credit deficiency factors are referred to as PULs for disclosure purposes. These loans were then evaluated to determine estimated fair values as of the acquisition date. Although no specific credit deficiencies were identifiable, we believe there is an element of risk as to whether all contractual cash flows will be eventually received. Factors that were considered included the economic environment both nationally and locally as well as the real estate market particularly in Florida. We have applied ASC Topic 310-20 accounting treatment to the PULs. The Company believes the deposits assumed from the acquisition have an intangible value. In determining the valuation amount, deposits were analyzed based on factors such as type of deposit, deposit retention, interest rates and age of deposit relationships. Pro-Forma Information Twelve Months Ended December 31, (In thousands, except per share data) 2017 2016 Net interest income $ 196,259 $ 170,363 Net income available to common shareholders 51,274 41,594 EPS - basic $ 1.11 $ 0.97 EPS - diluted $ 1.09 $ 0.96 Acquisition costs included in the Company’s income statement for the years ended December 31, 2017 and December 31, 2016 are $ 12.9 9.0

Significant Accounting Polici28

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
General	General: The consolidated financial statements include the accounts of Seacoast and all its majority-owned subsidiaries but exclude trusts created for the issuance of trust preferred securities. In consolidation, all significant intercompany accounts and transactions are eliminated. The accounting and reporting policies of the Company are in accordance with accounting principles generally accepted in the United States of America, and they conform to general practices within the applicable industries. Certain reclassifications have been made to prior period amounts to conform to the current period presentation. The reclassifications had no impact to net income or retained earnings.
Use of Estimates	Use of Estimates:
Cash and Cash Equivalents	Cash and Cash Equivalents:
Time deposits with other banks [Policy Text Block]	Time deposits with other banks:
Securities Purchased and Sold Agreements	Securities Purchased and Sold Agreements:
Securities	Securities: Realized gains and losses, including other than temporary impairments, are included in noninterest income as investment securities gains (losses). Interest and dividends on securities, including amortization of premiums and accretion of discounts, is recognized in interest income on an accrual basis using the interest method. The Company anticipates prepayments of principal in the calculation of the effective yield for collateralized mortgage obligations and mortgage backed securities by obtaining estimates of prepayments from independent third parties. The adjusted cost of each specific security sold is used to compute realized gains or losses on the sale of securities on a trade date basis. On a quarterly basis, the Company makes an assessment to determine whether there have been any events or economic circumstances to indicate that a security is impaired on an other-than-temporary basis. Management considers many factors including the length of time the security has had a fair value less than the cost basis; recent events specific to the issuer or industry; and for debt securities, external credit ratings and recent downgrades. Management also assesses whether it intends to sell, or it is more likely than not that it will be required to sell, a security in an unrealized loss position before recovery of its amortized cost basis. Securities on which there is an unrealized loss that is deemed to be other-than temporary are written down to fair value with the write-down recorded as a realized loss. In 2014, Seacoast transferred securities into held to maturity which had previously been classified as available for sale. The unrealized loss at the date of transfer was reported as a component of shareholders’ equity and is amortized over the remaining life as an adjustment of yield using the interest method. Seacoast Bank is a member of the Federal Home Loan Bank (“FHLB”) system. Members are required to own a certain amount of FHLB stock based on the level of borrowings and other factors, and may invest in additional amounts. FHLB stock is carried at cost, and periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are reported as income.
Loans	Loans: · Loans held for sale · Loans originated by Seacoast and held for investment · Loans purchased by Seacoast, which are considered purchased unimpaired (“PUL), and held for investment · Loans purchased by Seacoast, which are considered purchased credit impaired (“PCI”) Loans that are held for sale are carried as held for sale based on management’s intent to sell the loans, either as part of a core business strategy or related to a risk mitigation strategy. Loans held for sale and any related unfunded lending commitments are recorded at fair value, if elected, or the lower of cost (which is the carrying amount net of deferred fees and costs and applicable allowance for loan losses and reserve for unfunded lending commitments) or fair market value less costs to sell. Adjustments to reflect unrealized gains and losses resulting from changes in fair value and realized gains and losses upon ultimate sale of the loans are classified as noninterest income in the Consolidated Statements of Income. At the time of the transfer to loans held for sale, if the fair market value is less than cost, the difference is recorded as additional provision for credit losses in the results of operations. Fair market value is determined based on quoted market prices for the same or similar loans, outstanding investor commitments or discounted cash flow analyses using market assumptions. Fair market value for substantially all the loans in loans held for sale was obtained by reference to prices for the same or similar loans from recent transactions. Fair market value changes occur due to changes in interest rates, the borrower’s credit, the secondary loan market and the market for a borrower’s debt. Individual loans or pools of loans are transferred from the loan portfolio to loans held for sale when the intent to hold the loans has changed and there is a plan to sell the loans within a reasonable period of time. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are considered held for investment. Loans originated by Seacoast and held for investment are recognized at the principal amount outstanding, net of unearned income and amounts charged off. Unearned income includes discounts, premiums and deferred loan origination fees reduced by loan origination costs. Unearned income on loans is amortized to interest income over the life of the related loan using the effective interest rate method. Interest income is recognized on an accrual basis. As a part of business acquisitions, the Company acquires loans which are recorded at fair value on the acquisition date. Accordingly, the associated allowance for credit losses related to these loans is not carried over at the acquisition date. Any losses after acquisition are recognized through the allowance for loan losses. These loans fall into two groups: purchased unimpaired loans (“PUL”) and purchased credit-impaired loans (“PCI”). PULs demonstrate no evidence of significant credit deterioration and there is an expectation that all contractual payments will be made. The Company determines fair value by estimating the amount and timing of expected future cash flows and assigning a discount or premium to each loan. The difference between the expected cash flows and the amount paid is recorded as interest income over the remaining life of the loan. PCI loans demonstrate evidence of credit deterioration since origination and the risk that all contractual payments will not be made. The Company estimates fair value by estimating the amount of loan principal and interest cash flows expected to be collected, incorporating assumptions regarding default rates, loss severities, the amounts and timing of prepayments and other factors that are reflective of current market conditions on a quarterly basis. Probable decreases in expected loan principal cash flows trigger the recognition of impairment, which is then measured as the present value of the expected principal loss plus any related foregone interest cash flows discounted at the loan’s effective interest rate. Impairments that occur after the acquisition date are recognized through the provision for loan losses. Probable and significant increases in expected principal cash flows would first reverse any previously recorded allowance for loan losses; any remaining increases are recognized prospectively as interest income. The impacts of (i) prepayments, (ii) changes in variable interest rates, and (iii) any other changes in the timing of expected cash flows are recognized prospectively as adjustments to interest income. Disposals of loans, which may include sales of loans, receipt of payments in full by the borrower, or foreclosure, result in removal of the loan from the purchased credit impaired portfolio. In contrast, PULs are evaluated using the same procedures as used for the Company’s non-purchased loan portfolio. Under certain scenarios, the Company will grant modifications to a loan when a borrower is experiencing financial difficulties. Such modifications allow the Company to minimize the risk of loss on the loan and maximize future cash flows received from the borrower. Such modifications are referred to as troubled debt restructured (TDR) loans. TDRs are considered impaired and placed in nonaccrual status. If borrowers perform pursuant to the modified loan terms for at least six months and the remaining loan balances are considered collectible, the loans are returned to accrual status. The Company reviews all loans for impairment on a periodic basis. A loan is considered to be impaired when based on current information, it is probable the Company will not receive all amounts due in accordance with the contractual terms of a loan agreement. The fair value is measured based on either the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s observable market price or the fair value of the collateral if the loan is collateral dependent. When the ultimate collectability of the principal balance of an impaired loan is in doubt, all cash receipts are applied to principal. Once the recorded principal balance has been reduced to zero, future cash receipts are applied to interest income, to the extent any interest has been forgone, and then they are recorded as recoveries of any amounts previously charged off. The accrual of interest is generally discontinued on loans, except consumer loans, that become 90 120
Derivatives	Derivatives
Loan Commitments and letters of credit	Loan Commitments and letters of credit: Fees received for providing loan commitments and letters of credit that may result in loans are typically deferred and amortized to interest income over the life of the related loan, beginning with the initial borrowing. Fees on commitments and letters of credit are amortized to noninterest income as banking fees and commissions on a straight-line basis over the commitment period when funding is not expected.
Fair Value Measurements	Fair Value Measurements: Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Depending on the nature of the asset or liability, the Company uses various valuation techniques and assumptions when estimating fair value. The Company applies the following fair value hierarchy: Level 1 – Assets or liabilities for which the identical item is traded on an active exchange, such as publicly-traded instruments or futures contracts. Level 2 – Assets and liabilities valued based on observable market data for similar instruments. Level 3 – Assets and liabilities for which significant valuation assumptions are not readily observable in the market; instruments valued based on the best available data, some of which is internally-developed, and considers risk premiums that a market participant would require. When determining the fair value measurements for assets and liabilities required or permitted to be recorded at and/or marked to fair value, the Company considers the principal market in which it would transact and considers assumptions that market participants would use when pricing the asset or liability. When possible, the Company looks to active and observable markets to price identical assets or liabilities. When identical assets and liabilities are not traded in active markets, the Company looks to market observable data for similar assets and liabilities. Nevertheless, certain assets and liabilities are not actively traded in observable markets and the Company must use alternative valuation techniques to derive a fair value measurement.
Other Real Estate Owned	Other Real Estate Owned: OREO may also include bank premises no longer utilized in the course of our business (closed branches) that are initially recorded at the lower of carrying value or fair value, less costs to sell. If fair value of the premises is less than amortized book value, a write down is recorded through noninterest expense. Costs to operate the facility are expensed.
Bank Premises and Equipment	25 40 5 25 3 12
Intangible Assets	Intangible assets. The Company recognizes CDIs that result from either whole bank acquisitions or branch acquisitions. They are initially measured at fair value and then amortized over periods ranging from six to eight years on a straight line basis. The Company evaluates CDIs for impairment annually in the fourth quarter, or more often if circumstances arise that may indicate risk of impairment. If impaired, the CDI is written down with a corresponding impact to noninterest expense.
Bank owned life insurance (BOLI)	Bank owned life insurance (BOLI):
Revenue Recognition	Revenue Recognition:
Allowance for Loan Losses and Reserve for Unfunded Lending Commitments	Allowance for Loan Losses and Reserve for Unfunded Lending Commitments: The allowance for loan losses and reserve for unfunded lending commitments is maintained at a level the Company believes is adequate to absorb probable losses incurred in the loan portfolio and unfunded lending commitments as of the date of the consolidated financial statements. The Company employs a variety of modeling and estimation tools in developing the appropriate allowance for loan losses and reserve for unfunded lending commitments. The allowance for loan losses and reserve for unfunded lending commitments consists of formula-based components for commercial and consumer loans, allowance for impaired commercial loans and allowance related to additional factors that are believed indicative of current trends and business cycle issues. If necessary, a specific allowance is established for individually evaluated impaired loans. The specific allowance established for these loans is based on a thorough analysis of the most probable source of repayment, including the present value of the loan’s expected future cash flows, the loan’s estimated market value, or the estimated fair value of the underlying collateral depending on the most likely source of repayment. General allowances are established for loans grouped into pools based on similar characteristics. In this process, general allowance factors are based on an analysis of historical charge-off experience, portfolio trends, regional and national economic conditions, and expected loss given default derived from the Company’s internal risk rating process. The Company monitors qualitative and quantitative trends in the loan portfolio, including changes in the levels of past due, criticized and nonperforming loans. The distribution of the allowance for loan losses and reserve for unfunded lending commitments between the various components does not diminish the fact that the entire allowance for loan losses and reserve for unfunded lending commitments is available to absorb credit losses in the loan portfolio. The principal focus is, therefore, on the adequacy of the total allowance for loan losses and reserve for unfunded lending commitments. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Company’s bank subsidiary’s allowance for loan losses and reserve for unfunded lending commitments. These agencies may require such subsidiary to recognize changes to the allowance for loan losses and reserve for unfunded lending commitments based on their judgments about information available to them at the time of their examination.
Income Taxes	Income Taxes: On December 22, 2017, the Tax Cuts and Jobs Act (the “Tax Reform Act”) was signed into law. Some of the most significant impacts included a decrease in the highest marginal corporate tax, from 35 21 80 30 8.6 In February 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-02, which permits companies to reclassify the disproportionate tax effects in accumulated other comprehensive income (“AOCI”), caused by the Tax Reform Act, to retained earnings. The Company early adopted ASU 2018-02 in 2017, and elected to reclassify the income tax effects of the Tax Reform Act, totaling $ 0.7
Earnings per Share	Earnings per Share:
Stock-Based Compensation	Stock-Based Compensation:

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Amortized Cost and Fair Value of Securities Available for Sale and Held for Investment	The amortized cost and fair value of securities available for sale and held to maturity at December 31, 2017 and December 31, 2016 are summarized as follows: December 31, 2017 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) SECURITIES AVAILABLE FOR SALE U.S. Treasury securities and obligations of U.S. Government Sponsored Entities $ 9,475 $ 274 $ (5) $ 9,744 Mortgage-backed securities of U.S. Government Sponsored Entities 318,771 891 (3,306) 316,356 Collateralized mortgage obligations of U.S. Government Sponsored Entities 235,466 272 (4,694) 231,044 Commercial mortgage backed securities of U.S. Government Sponsored Entities 16,210 165 (34) 16,341 Private mortgage backed securities 18,056 384 0 18,440 Private collateralized mortgage obligations 47,045 605 (285) 47,365 Collateralized loan obligations 263,579 798 (68) 264,309 Obligations of state and political subdivisions 45,118 813 (70) 45,861 Corporate and other debt securities 6,500 0 (156) 6,344 $ 960,220 $ 4,202 $ (8,618) $ 955,804 SECURITIES HELD TO MATURITY Mortgage-backed securities of U.S. Government Sponsored Entities $ 172,261 $ 746 $ (1,392) $ 171,615 Collateralized mortgage obligations of U.S. Government Sponsored Entities 181,280 56 (2,767) 178,569 Commercial mortgage backed securities of U.S. Government Sponsored Entities 17,462 705 0 18,167 Collateralized loan obligations 40,523 303 0 40,826 Private mortgage backed securities 5,337 9 (53) 5,293 $ 416,863 $ 1,819 $ (4,212) $ 414,470 December 31, 2016 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) SECURITIES AVAILABLE FOR SALE U.S. Treasury securities and obligations of U.S. Government Sponsored Entities $ 12,073 $ 255 $ 0 $ 12,328 Mortgage-backed securities of U.S. Government Sponsored Entities 287,726 585 (4,823) 283,488 Collateralized mortgage obligations of U.S. Government Sponsored Entities 238,805 314 (5,065) 234,054 Commercial mortgage backed securities of U.S. Government Sponsored Entities 22,351 222 (28) 22,545 Private mortgage backed securities 32,780 0 (791) 31,989 Private collateralized mortgage obligations 67,542 563 (816) 67,289 Collateralized loan obligations 124,716 838 (665) 124,889 Obligations of state and political subdivisions 63,161 622 (895) 62,888 Corporate and other debt securities 74,121 257 (517) 73,861 Private commercial mortgage backed securities 37,534 111 (473) 37,172 $ 960,809 $ 3,767 $ (14,073) $ 950,503 SECURITIES HELD TO MATURITY Mortgage-backed securities of U.S. Government Sponsored Entities $ 159,941 $ 704 $ (1,243) $ 159,402 Collateralized mortgage obligations of U.S. Government Sponsored Entities 147,208 386 (2,630) 144,964 Commercial mortgage backed securities of U.S. Government Sponsored Entities 17,375 233 (74) 17,534 Collateralized loan obligations 41,547 430 (314) 41,663 Private mortgage backed securities 6,427 0 (109) 6,318 $ 372,498 $ 1,753 $ (4,370) $ 369,881
Amortized Cost and Fair Value of Securities by Contractual Maturity	The amortized cost and fair value of securities at December 31, 2017, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or repay obligations with or without call or prepayment penalties. Held to Maturity Available for Sale Amortized Fair Amortized Fair Cost Value Cost Value (In thousands) Due in less than one year $ 0 $ 0 $ 6,248 $ 6,473 Due after one year through five years 3,600 3,607 42,448 42,616 Due after five years through ten years 36,923 37,219 256,306 257,449 Due after ten years 0 0 13,170 13,376 40,523 40,826 318,172 319,914 Mortgage-backed securities of U.S. Government Sponsored Entities 172,261 171,616 318,771 316,356 Collateralized mortgage obligations of U.S. Government Sponsored Entities 181,279 178,567 235,466 231,044 Commercial mortgage backed securities of U.S. Government Sponsored Entities 17,463 18,168 16,210 16,341 Private mortgage-backed securities 0 0 18,056 18,440 Private collateralized mortgage obligations 5,337 5,293 47,045 47,365 Corporate and other debt securities 0 0 6,500 6,344 $ 416,863 $ 414,470 $ 960,220 $ 955,804
Schedule of Unrealized Loss and Fair Value on Investments	The tables below indicate the amount of securities with unrealized losses and period of time for which these losses were outstanding at December 31, 2017 and December 31, 2016, respectively. December 31, 2017 Less than 12 months 12 months or longer Total Fair Unrealized Fair Unrealized Fair Unrealized Value Losses Value Losses Value Losses (In thousands) U.S. Treasury securities and obligations of U.S. Government Sponsored Entities $ 1,107 $ (5) $ 0 $ 0 $ 1,107 $ (5) Mortgage-backed securities of U.S. Government Sponsored Entities 123,195 (515) 213,590 (4,183) 336,785 (4,698) Collateralized mortgage obligations of U.S. Government Sponsored Entities 176,452 (1,507) 199,086 (5,955) 375,538 (7,462) Commercial mortgage backed securities of U.S. Government Sponsored Entities 5,076 (25) 1,049 (9) 6,125 (34) Private mortgage backed securities 0 0 0 0 0 0 Private collateralized mortgage obligations 0 0 20,744 (338) 20,744 (338) Collateralized loan obligations 14,933 (68) 0 0 14,933 (68) Obligations of state and political subdivisions 5,414 (14) 5,864 (56) 11,278 (70) Corporate and other debt securities 6,500 (156) 0 0 6,500 (156) Total temporarily impaired securities $ 332,677 $ (2,290) $ 440,333 $ (10,541) $ 773,010 $ (12,831) December 31, 2016 Less than 12 months 12 months or longer Total Fair Unrealized Fair Unrealized Fair Unrealized Value Losses Value Losses Value Losses (In thousands) Mortgage-backed securities of U.S. Government Sponsored Entities $ 327,759 $ (5,991) $ 5,387 $ (75) $ 333,146 $ (6,066) Collateralized mortgage obligations of U.S. Government Sponsored Entities 234,175 (5,599) 58,912 (2,096) 293,087 (7,695) Commercial mortgage backed securities of U.S. Government Sponsored Entities 7,934 (102) 0 0 7,934 (102) Private mortgage backed securities 0 0 36,848 (900) 36,848 (900) Private collateralized mortgage obligations 1,460 0 38,417 (816) 39,877 (816) Collateralized loan obligations 8,152 (41) 51,694 (938) 59,846 (979) Obligations of state and political subdivisions 39,321 (895) 0 0 39,321 (895) Corporate and other debt securities 33,008 (517) 0 0 33,008 (517) Private commercial mortgage backed securities 12,667 (306) 7,139 (167) 19,806 (473) Total temporarily impaired securities $ 664,476 $ (13,451) $ 198,397 $ (4,992) $ 862,873 $ (18,443)

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	The following table outlines net loans balances by category as of: December 31, 2017 Portfolio Loans PCI Loans PULs Total (In thousands) Construction and land development $ 215,315 $ 1,121 $ 126,689 $ 343,125 Commercial real estate 1,170,618 9,776 459,598 1,639,992 Residential real estate 845,420 5,626 187,764 1,038,810 Commercial and financial (2) 512,430 894 92,690 606,014 Consumer 178,826 0 10,610 189,436 NET LOAN BALANCES (1) $ 2,922,609 $ 17,417 $ 877,351 $ 3,817,377 December 31, 2016 Portfolio Loans PCI Loans PULs Total (In thousands) Construction and land development $ 137,480 $ 114 $ 22,522 $ 160,116 Commercial real estate 1,041,915 11,257 304,420 1,357,592 Residential real estate 784,290 684 51,813 836,787 Commercial and financial (2) 308,731 941 60,917 370,589 Consumer 153,434 0 1,018 154,452 NET LOAN BALANCES (1) $ 2,425,850 $ 12,996 $ 440,690 $ 2,879,536 (1) Net loan balances at December 31, 2017 and 2016 include deferred costs of $ 11.5 10.6 (2) Commercial and financial includes equipment lease financing of $ 30.3 0
Past Due Financing Receivables	Accruing Accruing Accruing Greater Total 30-59 Days 60-89 Days Than Financing December 31, 2017 (in thousands) Current Past Due Past Due 90 Days Nonaccrual Receivables Portfolio Loans Construction and land development $ 215,077 $ 0 $ 0 $ 0 $ 238 $ 215,315 Commercial real estate 1,165,738 2,605 585 0 1,690 1,170,618 Residential real estate 836,117 812 75 0 8,416 845,420 Commercial and financial 507,501 2,776 26 0 2,127 512,430 Consumer 178,676 52 0 0 98 178,826 Total Portfolio Loans 2,903,109 6,245 686 0 12,569 2,922,609 Purchased Unimpaired Loans Construction and land development 126,655 34 0 0 0 126,689 Commercial real estate 457,899 979 0 0 720 459,598 Residential real estate 186,549 128 87 0 1,000 187,764 Commercial and financial 92,315 54 0 0 321 92,690 Consumer 10,610 0 0 0 0 10,610 Total Purchased Unimpaired Loans 874,028 1,195 87 0 2,041 877,351 Purchased Credit Impaired Loans Construction and land development 1,121 0 0 0 0 1,121 Commercial real estate 9,352 0 0 0 424 9,776 Residential real estate 544 642 0 0 4,440 5,626 Commercial and financial 844 0 0 0 50 894 Consumer 0 0 0 0 0 0 Total Purchased Credit Impaired Loans 11,861 642 0 0 4,914 17,417 Total Loans $ 3,788,998 $ 8,082 $ 773 $ 0 $ 19,524 $ 3,817,377 Accruing Accruing Accruing Greater Total 30-59 Days 60-89 Days Than Financing December 31, 2016 (in thousands) Current Past Due Past Due 90 Days Nonaccrual Receivables Portfolio Loans Construction and land development $ 137,042 $ 0 $ 0 $ 0 $ 438 $ 137,480 Commercial real estate 1,039,882 78 171 0 1,784 1,041,915 Residential real estate 773,877 1,570 261 0 8,582 784,290 Commercial and financial 308,652 30 0 0 49 308,731 Consumer 153,176 29 59 0 170 153,434 Total Portfolio Loans 2,412,629 1,707 491 0 11,023 2,425,850 Purchased Unimpaired Loans Construction and land development 22,490 0 0 0 32 22,522 Commercial real estate 302,318 345 485 0 1,272 304,420 Residential real estate 50,398 153 0 0 1,262 51,813 Commercial and financial 60,353 39 328 0 197 60,917 Consumer 981 37 0 0 0 1,018 Total Purchased Unimpaired Loans 436,540 574 813 0 2,763 440,690 Purchased Credit Impaired Loans Construction and land development 114 0 0 0 0 114 Commercial real estate 6,972 0 0 0 4,285 11,257 Residential real estate 499 0 185 0 0 684 Commercial and financial 941 0 0 0 0 941 Consumer 0 0 0 0 0 0 Total Purchased Credit Impaired Loans 8,526 0 185 0 4,285 12,996 Total Loans $ 2,857,695 $ 2,281 $ 1,489 $ 0 $ 18,071 $ 2,879,536
Financing Receivable Credit Quality Indicators	The following tables present the risk category of loans by class of loans based on the most recent analysis performed as of: December 31, 2017 Special Pass Mention Substandard Doubtful Total (In thousands) Construction and land development $ 328,127 $ 10,414 $ 4,584 $ 0 $ 343,125 Commercial real estate 1,586,932 29,273 23,787 0 1,639,992 Residential real estate 1,023,925 4,621 10,203 61 1,038,810 Commercial and financial 593,689 3,237 8,838 250 606,014 Consumer 189,354 0 82 0 189,436 Total Loans $ 3,722,027 $ 47,545 $ 47,494 $ 311 $ 3,817,377 December 31, 2016 Special Pass Mention Substandard Doubtful Total (In thousands) Construction and land development $ 148,607 $ 5,037 $ 6,472 $ 0 $ 160,116 Commercial real estate 1,324,685 17,184 15,724 0 1,357,593 Residential real estate 811,934 1,780 23,073 0 836,787 Commercial and financial 364,241 3,949 2,399 0 370,589 Consumer 153,774 67 611 0 154,452 Total loans $ 2,803,241 $ 28,017 $ 48,279 $ 0 $ 2,879,536
Contractually Required Principal And Interest Cash Payments Changes	The table below summarizes the changes in accretable yield on PCI loans for the years ended: December 31, 2017 2016 2015 (In thousands) Beginning balance $ 3,807 $ 2,610 $ 1,192 Additions 763 2,052 702 Deletions (11) (15) (357) Accretion (1,647) (1,734) (601) Reclassifications from non-accretable difference 787 894 1,674 Ending Balance $ 3,699 $ 3,807 $ 2,610
Troubled Debt Restructurings on Financing Receivables	The following table presents accruing loans that were modified within the twelve months ending: Number of Pre- Post-Modification Valuation (In thousands) December 31, 2017: Construction and Land Development 1 $ 52 $ 46 $ 6 Residential Real Estate 1 15 15 0 Total 2 $ 67 $ 61 $ 6 December 31, 2016: Construction and Land Development 1 $ 20 $ 18 $ 2 Residential Real Estate 4 1,169 1,019 150 Total 5 $ 1,189 $ 1,037 $ 152
Impaired Financing Receivables	At December 31, 2017 and 2016, the Company’s recorded investment in impaired loans, excluding PCI loans, and related valuation allowance was as follows: December 31, 2017 Unpaid Related Recorded Principal Valuation (In thousands) Investment Balance Allowance Impaired Loans with No Related Allowance Recorded: Construction and land development $ 223 $ 510 $ 0 Commercial real estate 3,475 4,873 0 Residential real estate 10,272 15,063 0 Commercial and financial 19 29 0 Consumer 105 180 0 Impaired Loans with an Allowance Recorded: Construction and land development 251 264 23 Commercial real estate 4,780 4,780 195 Residential real estate 8,448 8,651 1,091 Commercial and financial 2,436 883 1,050 Consumer 282 286 43 Total: Construction and land development 474 774 23 Commercial real estate 8,255 9,653 195 Residential real estate 18,720 23,714 1,091 Commercial and financial 2,455 912 1,050 Consumer 387 466 43 $ 30,291 $ 35,519 $ 2,402 December 31, 2016 Unpaid Related Recorded Principal Valuation (In thousands) Investment Balance Allowance Impaired Loans with No Related Allowance Recorded: Construction and land development $ 226 $ 321 $ 0 Commercial real estate 3,267 4,813 0 Residential real estate 9,706 14,136 0 Commercial and financial 199 206 0 Consumer 0 0 0 Impaired Loans with an Allowance Recorded: Construction and land development 51 51 0 Commercial real estate 6,937 6,949 395 Residential real estate 12,332 12,681 2,059 Commercial and financial 0 0 0 Consumer 0 0 0 Total: Construction and land development 277 372 0 Commercial real estate 10,204 11,762 395 Residential real estate 22,038 26,817 2,059 Commercial and financial 199 206 0 Consumer 0 0 0 $ 32,718 $ 39,157 $ 2,454

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Credit Losses on Financing Receivables	Activity in the allowance for loans losses for the three years ended December 31, 2017, 2016 and 2015 is summarized as follows: Beginning Provision Charge- Recoveries TDR Ending (In thousands) December 31 , 2017 Construction and land development $ 1,219 $ (471) $ 0 $ 896 $ (2) $ 1,642 Commercial real estate 9,273 (264) (407) 747 (64) 9,285 Residential real estate 7,483 125 (569) 336 (244) 7,131 Commercial and financial 3,636 5,304 (1,869) 226 0 7,297 Consumer 1,789 954 (1,257) 290 (9) 1,767 Total $ 23,400 $ 5,648 $ (4,102) $ 2,495 $ (319) $ 27,122 December 31 , 2016 Construction and land development $ 1,151 $ (150) $ 0 $ 226 $ (8) $ 1,219 Commercial real estate 6,756 2,599 (256) 306 (132) 9,273 Residential real estate 8,057 (1,069) (205) 786 (86) 7,483 Commercial and financial 2,042 224 (439) 1,809 0 3,636 Consumer 1,122 807 (244) 109 (5) 1,789 Total $ 19,128 $ 2,411 $ (1,144) $ 3,236 $ (231) $ 23,400 December 31 , 2015 Construction and land development $ 722 $ 1,296 $ (1,271) $ 404 $ 43 $ 1,151 Commercial real estate 4,528 2,010 (263) 700 (69) 6,756 Residential real estate 9,784 (2,208) (779) 1,260 (150) 8,057 Commercial and financial 1,179 1,058 (726) 531 (6) 2,042 Consumer 794 552 (341) 117 (36) 1,122 Total $ 17,007 $ 2,708 $ (3,380) $ 3,012 $ (218) $ 19,128
Loan Portfolio And Related Allowance	Individually Evaluated for Collectively Evaluated for Total Recorded Associated Recorded Associated Recorded Associated (In thousands) December 31, 2017 Construction and land development $ 474 $ 23 $ 341,530 $ 1,619 $ 342,004 $ 1,642 Commercial real estate 8,255 195 1,621,960 9,090 1,630,215 9,285 Residential real estate 18,720 1,091 1,014,465 6,040 1,033,185 7,131 Commercial and financial 2,455 1,050 602,666 6,247 605,121 7,297 Consumer 387 43 189,049 1,724 189,436 1,767 Total $ 30,291 $ 2,402 $ 3,769,670 $ 24,720 $ 3,799,961 $ 27,122 Individually Evaluated for Collectively Evaluated for Impairment Impairment Total Recorded Associated Recorded Associated Recorded Associated (In thousands) December 31, 2016 Construction and land development $ 277 $ 0 $ 159,839 $ 1,219 $ 160,116 $ 1,219 Commercial real estate 10,204 395 1,324,276 8,878 1,334,480 9,273 Residential real estate 22,038 2,059 813,751 5,424 835,789 7,483 Commercial and financial 199 0 368,508 3,636 368,707 3,636 Consumer 0 0 154,452 1,789 154,452 1,789 Total $ 32,718 $ 2,454 $ 2,820,826 $ 20,946 $ 2,853,544 $ 23,400
PCI Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loan Portfolio And Related Allowance	The table below summarizes PCI loans that were individually evaluated for impairment based on expected cash flows at December 31, 2017 and 2016. December 31, 2017 December 31, 2016 PCI Loans Individually PCI Loans Individually Recorded Associated Recorded Associated (In thousands) Construction and land development $ 1,121 $ 0 $ 114 $ 0 Commercial real estate 9,776 0 11,257 0 Residential real estate 5,626 0 684 0 Commercial and financial 894 0 941 0 Consumer 0 0 0 0 Total $ 17,417 $ 0 $ 12,996 $ 0

Bank Premises and Equipment (Ta

Bank Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Summary of Bank Premises and Equipment	Bank premises and equipment as of: Accumulated Net Depreciation &; Carrying Cost Amortization Value (In thousands) December 31, 2017 Premises (including land of $18,269) $ 78,255 $ (24,045) $ 54,210 Furniture and equipment 34,532 (21,859) 12,673 Total $ 112,787 $ (45,904) $ 66,883 December 31, 2016 Premises (including land of $14,773) $ 71,562 $ (22,969) $ 48,593 Furniture and equipment 30,281 (20,190) 10,091 Total $ 101,843 $ (43,159) $ 58,684

Goodwill and Acquired Intangi33

Goodwill and Acquired Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	For the Year Ended December 31, 2017 2016 2015 (In thousands) Beginning of year $ 64,649 $ 25,211 $ 25,309 Changes from business combinations 82,929 39,438 0 Other 0 0 (98) Total Goodwill $ 147,578 $ 64,649 $ 25,211
Acquired intangible assets consist of core deposit intangibles	Acquired intangible assets consist of core deposit intangibles ("CDI"), which are intangible assets arising from the purchase of deposits separately or from bank acquisitions. For the Year Ended December 31, 2017 2016 2015 (In thousands) Beginning of year $ 14,572 $ 8,594 $ 7,454 Acquired CDI 7,726 8,464 2,564 Amortization expense (3,361) (2,486) (1,424) End of year $ 18,937 $ 14,572 $ 8,594 (In months) Remaining Average Amortization Period for CDI 63 64 67
Gross Carrying Amount and Accumulated Amortization of Intangible Asset	The gross carrying amount and accumulated amortization of the Company's CDI subject to amortization as of: December 31, 2017 December 31, 2016 Gross Gross Carrying Accumulated Carrying Accumulated Amount Amortization Amount Amortization (In thousands) Deposit base $ 26,522 $ (7,585) $ 18,796 $ (4,224)

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Federal Funds Purchased and Securities Sold Under Agreements to Repurchase	A significant portion of the Company's short-term borrowings were comprised of unsecured federal funds purchased and securities sold under agreements to repurchase with maturities primarily from overnight to seven days For the Year Ended December 31, 2017 2016 2015 (In thousands) Maximum amount outstanding at any month end $ 216,094 $ 236,099 $ 192,786 Weighted average interest rate at end of year 0.71 % 0.31 % 0.28 % Average amount outstanding $ 171,686 $ 187,560 $ 168,188 Weighted average interest rate during the year 0.46 % 0.26 % 0.20 %
Collateral Securities Pledge Maturity	Company securities pledged were as follows by collateral type and maturity as of: December 31, 2017 2016 2015 (In thousands) Fair-Value of Pledge Securities – overnight and continuous Mortgage-backed securities and collateralized mortgage obligations of U.S. Government Sponsored Entities $ 216,094 $ 204,202 $ 172,005

Employee Benefits and Stock C35

Employee Benefits and Stock Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs	The impact of share-based compensation on the Company’s financial results is presented below: For the Year Ended December 31, (In thousands) 2017 2016 2015 Share-based compensation expense $ 5,267 $ 4,154 2,859 Income tax benefit (1,966) (1,602) (963)
Schedule of Unrecognized Compensation Cost, Nonvested Awards	The total unrecognized compensation cost and the weighted-average period over which unrecognized compensation cost is expected to be recognized related to non-vested share-based compensation arrangements at December 31, 2017 is presented below: (In thousands) Unrecognized Weighted- Restricted stock awards $ 2,383 1.7 Restricted stock units 3,403 1.7 Stock options 1,374 2.4 Total $ 7,160 1.8
Schedule of Nonvested Share Activity	A summary of the status of the Company’s non-vested RSUs as of December 31, 2017, and changes during the year then ended, is presented below: (In thousands, except share and per share data) Restricted Weighted- Non-vested at January 1, 2017 206,952 $ 14.72 Granted 114,331 24.08 Forfeited/Cancelled (8,733) 20.76 Vested (99,574) 14.13 Non-vested at December 31, 2017 212,976 19.77
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	(In thousands, except share and per share data) Year Ended December 31, 2017 2016 2015 Shares granted 114,331 164,599 123,806 Weighted-average grant date fair value $ 24.08 $ 16.03 $ 15.03 Fair value of awards vested (1) $ 1,407 $ 1,981 $ 836 (1)
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The Company estimated the fair value of each option grant on the date of grant using the Black-Scholes options-pricing model with the following weighted-average assumptions: For the Year Ended December 31, 2017 2016 2015 Risk-free interest rates 1.85 % 1.63 % 1.65 % Expected dividend yield 0 % 0 % 0 % Expected volatility 25.4 % 21.9 % 15.5 % Expected lives (years) 5.0 5.0 5.0
Schedule of Stock Options Roll Forward	A summary of the Company’s stock options as of December 31, 2017, and changes during the year then ended, are presented below: Options Weighted- Weighted- Aggregate Outstanding at January 1, 2017 778,778 $ 15.86 Granted 297,576 28.21 Exercised (91,468) 11.77 Forfeited (33,537) 96.17 Outstanding at December 31, 2017 951,349 17.29 6.86 $ 8,493 Exercisable at December 31, 2017 517,100 12.09 5.85 6,787
Schedule of Share-based Compensation, Stock Options, Activity	Information related to stock options during each of the following years: (In thousands, except share and per share data) For the Year Ended December 31, 2017 2016 2015 Options granted 297,576 243,391 63,650 Weighted-average grant date fair value $ 4.66 $ 3.41 $ 2.21 Intrinsic value of stock options exercised 1,143 80 -
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range	The following table summarizes information related to stock options as of December 31, 2017: Range of Exercise Prices Options Remaining Shares Weighted $10.54 to $10.78 330,000 5.8 330,000 $ 10.67 $10.97 to $15.99 323,773 5.8 163,538 13.42 $22.65 to $28.69 297,576 9.2 23,562 22.65 Total 951,349 6.9 517,100 $ 12.09
Schedule of Share-based Compensation, Employee Stock Purchase Plan, Activity	The Employee Stock Purchase Plan (“ESPP”), as amended, was approved by shareholders on April 25, 1989, and additional shares were authorized for issuance by shareholders on June 18, 2009 and May 2, 2013. Under the ESPP, the Company is authorized to issue up to 300,000 95 2017 2016 2015 ESPP shares purchased 12,434 10,483 9,083 Weighted-average employee purchase price $ 22.67 $ 16.02 $ 13.99
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Nonvested Share Activity	A summary of the status of the Company’s non-vested RSUs as of December 31, 2017, and changes during the year then ended, is presented below: (In thousands, except share and per share data) Restricted Weighted- Non-vested at January 1, 2017 322,692 $ 12.61 Granted 164,268 21.61 Forfeited/Cancelled (22,113) 13.79 Vested (88,880) 10.54 Non-vested at December 31, 2017 375,967 16.96
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	(In thousands, except share and per share data) For the Year Ended December 31, 2017 2016 2015 Shares granted 164,268 136,188 127,128 Weighted-average grant date fair value $ 23.94 $ 13.53 $ 12.63 Fair value of awards vested (1) $ 937 $ 846 $ - (1)

Lease Commitments (Tables)

Lease Commitments (Tables)	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Future Minimum Lease Payments under Operating Leases	The Company is obligated under various noncancellable operating leases for equipment, buildings, and land. Minimum rent payments under operating leases are recognized on a straight-line basis over the term of the lease. At December 31, 2017, future minimum lease payments under leases with initial or remaining terms in excess of one year are as follows: (In thousands) 2018 $ 6,303 2019 5,935 2020 5,324 2021 4,003 2022 3,275 Thereafter 15,885 $ 40,725

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The provision for income taxes is as follows: For the Year Ended December 31 2017 2016 2015 (In thousands) Current Federal $ 667 $ 653 $ 578 State 2 30 61 Deferred Federal 32,791 12,163 10,818 State 2,876 2,043 2,070 $ 36,336 $ 14,889 $ 13,527
Schedule of Effective Income Tax Rate Reconciliation	35 For the Year Ended December 31 2017 2016 2015 (In thousands) Tax rate applied to income before income taxes $ 27,720 $ 15,431 $ 12,484 Increase (decrease) resulting from the effects of: Tax law change 8,552 0 0 Nondeductible acquisition costs 657 217 441 Tax exempt interest on loans, obligations of states and political subdivisions and bank owned life insurance (1,445) (1,215) (761) State income taxes (1,007) (726) (746) Nontaxable bargain purchase gain 0 0 (146) Tax credit investments (165) (55) 0 Stock compensation (1,027) (731) 127 Other 173 (105) (3) Federal tax provision 33,458 12,816 11,396 State tax provision 2,878 2,073 2,131 Total income tax provision $ 36,336 $ 14,889 $ 13,527
Schedule of Deferred Tax Assets and Liabilities	The net deferred tax assets (liabilities) are comprised of the following as of: December 31, 2017 2016 (In thousands) Allowance for loan losses $ 7,187 $ 9,477 Premises and equipment 1,390 2,334 Other real estate owned 207 841 Accrued stock compensation 1,569 1,561 Federal tax loss carryforward 4,755 28,089 State tax loss carryforward 5,578 6,123 Alternative minimum tax credit carryforward 2,209 4,261 Net unrealized securities losses 1,429 4,616 Deferred compensation 2,125 3,279 Accrued interest and fee income 2,411 3,267 Other 2,248 3,748 Gross deferred tax assets 31,108 67,596 Less: Valuation allowance 0 0 Deferred tax assets net of valuation allowance 31,108 67,596 Core deposit base intangible (3,964) (3,953) Other (1,727) (2,825) Gross deferred tax liabilities (5,691) (6,778) Net deferred tax assets $ 25,417 $ 60,818
Summary of Income Tax Examinations	The Company has no unrecognized income tax benefits or provisions due to uncertain income tax positions. The following are the major tax jurisdictions in which the Company operates and the earliest tax year, exclusive of the impact of the net operating loss carryforwards, subject to examination: Jurisdiction Tax Year United States of America 2014 Florida 2014
Retained earnings and accumulated other comprehensive income before and after adjustment [Text Block]	Unadjusted as of December 31, 2017 Adjustment Adjusted as of December 31, 2017 Retained Earnings $ 29,208 $ 706 $ 29,914 Accumulated Other Comprehensive Income (3,510) (706) (4,216)

Noninterest Income and Expens38

Noninterest Income and Expenses (Tables)	12 Months Ended
	Dec. 31, 2017
Noninterest Income and Expenses [Abstract]
Summary of Noninterest Income and Expense	Details of noninterest income and expense is as follows: For the Year Ended December 31, 2017 2016 2015 (In thousands) Noninterest income Service charges on deposit accounts $ 10,049 $ 9,669 $ 8,563 Trust fees 3,705 3,433 3,132 Mortgage banking fees 6,449 5,864 4,252 Brokerage commissions and fees 1,352 2,044 2,132 Marine finance fees 910 673 1,152 Interchange income 10,583 9,227 7,684 Other deposit based EFT fees 465 477 397 BOLI Income 3,426 2,213 1,426 Gain on participated loan 0 0 725 Other 6,291 3,827 2,555 43,230 37,427 32,018 Securities gains, net 86 368 161 Gain on sale of VISA stock 15,153 0 0 Bargain purchase gain, net 0 0 416 TOTAL $ 58,469 $ 37,795 $ 32,595 Noninterest expense Salaries and wages $ 65,692 $ 54,096 $ 41,075 Employee benefits 11,732 9,903 9,564 Outsourced data processing costs 14,116 13,516 10,150 Telephone / data lines 2,291 2,108 1,797 Occupancy 13,290 13,122 8,744 Furniture and equipment 6,067 4,720 3,434 Marketing 4,784 3,633 4,428 Legal and professional fees 11,022 9,596 8,022 FDIC assessments 2,326 2,365 2,212 Amortization of intangibles 3,361 2,486 1,424 Asset dispositions expense 411 553 472 Net (gain)/loss on other real estate owned and repossessed assets (711) (509) 239 Early redemption cost for Federal Home Loan Bank advances 0 1,777 0 Other 15,535 13,515 12,209 TOTAL $ 149,916 $ 130,881 $ 103,770

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Summary of Required Regulatory Capital	Required Regulatory Capital Minimum for Capital Adequacy Minimum To Be Well Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) SEACOAST BANKING CORP (CONSOLIDATED) At December 31, 2017: Total Capital Ratio (to risk-weighted assets) $ 619,746 14.24 % $ 348,191 ≥ 8.00 % n/a n/a Tier 1 Capital Ratio (to risk-weighted assets) 592,562 13.61 261,143 ≥ 6.00 % n/a n/a Common Equity Tier 1 Capital (to risk-weighted assets) 523,832 12.04 195,858 ≥ 4.50 % n/a n/a Tier 1 Leverage Ratio (to adjusted average assets) 592,562 10.68 221,863 ≥ 4.00 % n/a n/a At December 31, 2016: Total Capital Ratio (to risk-weighted assets) $ 432,058 13.25 % $ 260,790 ≥ 8.00 % n/a n/a Tier 1 Capital Ratio (to risk-weighted assets) 408,596 12.53 195,592 ≥ 6.00 % n/a n/a Common Equity Tier 1 Capital (to risk-weighted assets) 351,769 10.79 146,694 ≥ 4.50 % n/a n/a Tier 1 Leverage Ratio (to adjusted average assets) 408,596 9.15 178,656 ≥ 4.00 % n/a n/a SEACOAST NATIONAL BANK (A WHOLLY OWNED BANK SUBSIDIARY) At December 31, 2017: Total Capital Ratio (to risk-weighted assets) $ 565,149 13.04 % $ 346,780 ≥ 8.00 % $ 433,475 ≥ 10.00 % Tier 1 Capital Ratio (to risk-weighted assets) 537,965 12.41 260,085 ≥ 6.00 % 346,780 ≥ 8.00 % Common Equity Tier 1 Capital (to risk-weighted assets) 537,965 12.41 195,022 ≥ 4.50 % 281,759 ≥ 6.50 % Tier 1 Leverage Ratio (to adjusted average assets) 537,965 9.72 221,432 ≥ 4.00 % 276,791 ≥ 5.00 % At December 31, 2016: Total Capital Ratio (to risk-weighted assets) $ 415,147 12.75 % $ 260,491 ≥ 8.00 % $ 325,987 ≥ 10.00 % Tier 1 Capital Ratio (to risk-weighted assets) 391,685 12.03 195,368 ≥ 6.00 % 260,790 ≥ 8.00 % Common Equity Tier 1 Capital (to risk-weighted assets) 391,685 12.03 146,526 ≥ 4.50 % 211,892 ≥ 6.50 % Tier 1 Leverage Ratio (to adjusted average assets) 391,685 8.78 178,501 ≥ 4.00 % 223,320 ≥ 5.00 % (1) Excludes capital conservation buffer of 1.250% the Company is subject to, which if not exceeded may constrain dividends, equity repurchases and compensation.

(Parent Company Only) Financi40

(Parent Company Only) Financial Information (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Summary of Balance Sheet	Balance Sheets December 31, 2017 2016 (In thousands) ASSETS Cash $ 1,154 $ 648 Securities purchased under agreement to resell with subsidiary bank, maturing within 30 days 33,151 12,676 Investment in subsidiaries 711,973 494,809 Other assets 21,337 1,211 $ 767,615 $ 509,344 LIABILITIES AND SHAREHOLDERS' EQUITY Subordinated debt $ 70,521 $ 70,241 Other liabilities 7,430 3,706 Shareholders' equity 689,664 435,397 $ 767,615 $ 509,344
Summary of Statements of Income (Loss)	Statements of Income (Loss) Year Ended December 31 2017 2016 2015 (In thousands) Income Interest/other $ 2,104 $ 352 $ 115 Dividends from subsidiary Bank 0 0 0 Gain on sale of VISA stock 15,153 0 0 17,257 352 115 Interest expense 2,499 2,115 1,671 Other expenses 649 462 317 Income (loss) before income taxes and equity in undistributed income of subsidiaries 14,109 (2,225) (1,873) Income tax provision (benefit) benefit 4,938 (801) (661) Income (loss) before equity in undistributed income of subsidiaries 9,171 (1,424) (1,212) Equity in undistributed income of subsidiaries 33,694 30,626 23,353 Net income $ 42,865 $ 29,202 $ 22,141
Summary of Statement of Cash Flows	Statements of Cash Flows Year Ended December 31 2017 2016 2015 (In thousands) Cash flows from operating activities Adjustments to reconcile net income to net cash provided by operating activities: Net Income $ 42,865 $ 29,202 $ 22,141 Equity in undistributed income of subsidiaries (33,694) (30,626) (23,353) Gain on sale of VISA stock (15,153) 0 0 Net (increase) decrease in other assets 1,415 (12) 10 Net increase (decrease) in other liabilities 4,005 12 (48) Net cash used in operating activities (562) (1,424) (1,250) Cash flows from investing activities Net cash paid for bank acquisition (27,862) (28,905) 0 Investment in unconsolidated subsidiary 0 (200) 0 Investment in VISA stock (6,180) 0 0 Decrease (increase) in securities purchased under agreement to resell, maturing within 30 days, net (20,475) 30,647 (5,487) Net cash provided by (used in) investment activities (54,517) 1,542 (5,487) Cash flows from financing activities Issuance of common stock, net of related expense 55,641 0 0 Subordinated debt increase 0 0 6,494 Stock based employment plans (56) 166 127 Net cash provided by financing activities 55,585 166 6,621 Net change in cash 506 284 (116) Cash at beginning of year 648 364 480 Cash at end of year $ 1,154 $ 648 $ 364 Supplemental disclosure of cash flow information: Cash paid during the period for interest $ 2,205 $ 1,824 $ 1,487

Contingent Liabilities and Co41

Contingent Liabilities and Commitments with Off-Balance Sheet Risk (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Summary of Financial Instruments with Off-Balance-Sheet Risk	Unfunded commitments for the Company as of: December 31, 2017 2016 (In thousands) Contract or Notional Amount Financial instruments whose contract amounts represent credit risk: Commitments to extend credit $ 807,651 $ 532,082 Standby letters of credit and financial guarantees written: Secured 12,913 10,776 Unsecured 681 554 Unfunded limited partner equity commitment 10,914 10,148

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis	Under ASC 820, fair value measurements for items measured at fair value on a recurring and nonrecurring basis at December 31, 2017 and December 31, 2016 included: Quoted Prices in Significant Other Significant Other Active Markets for Observable Unobservable Fair Value Identical Assets Inputs Inputs (In thousands) Measurements Level 1 Level 2 Level 3 At December 31, 2017 Available for sale securities (1) $ 955,804 $ 6,600 $ 949,204 $ 0 Loans held for sale (2) 24,306 0 24,306 0 Loans (3) 4,192 0 3,454 738 Other real estate owned (4) 7,640 0 60 7,580 At December 31, 2016 Available for sale securities (1) $ 950,503 $ 100 $ 950,403 $ 0 Loans held for sale (2) 15,332 0 15,332 0 Loans (3) 4,120 0 3,170 950 Other real estate owned (4) 9,949 0 0 9,949 (1) See Note D for further detail of fair value of individual investment categories. (2) Recurring fair value basis determined using observable market data. (3) See Note E. Nonrecurring fair value adjustments to loans identified as impaired reflect full or partial write- downs that are based on the loan’s observable market price or current appraised value of the collateral in accordance with ASC 310. (4) Fair value is measured on a nonrecurring basis in accordance with ASC 360.
Fair Value Measurements, Recurring and Nonrecurring	The carrying amount and fair value of the Company's other significant financial instruments that were not disclosed previously in the balance sheet and for which carrying amount is not fair value as of December 31, 2017 and December 31, 2016 is as follows: Quoted Prices in Significant Other Significant Other Active Markets for Observable Unobservable Carrying Identical Assets Inputs Inputs (In thousands) Amount Level 1 Level 2 Level 3 At December 31, 2017 Financial Assets Securities held to maturity (1) $ 416,863 $ 0 $ 414,472 $ 0 Time deposits with other banks 12,553 0 0 12,493 Loans, net 3,786,063 0 0 3,760,754 Financial Liabilities Deposits 4,592,720 0 0 4,588,515 Subordinated debt 70,521 0 61,530 0 At December 31, 2016 Financial Assets Securities held to maturity (1) $ 372,498 $ 0 $ 369,881 $ 0 Loans, net 2,852,016 0 0 2,840,993 Financial Liabilities Deposits 3,523,245 0 0 3,523,322 Subordinated debt 70,241 0 54,908 0 (1) See Note D for further detail of recurring fair value basis of individual investment categories.
Schedule of contractual balance and gains or losses aggregate fair value	Interest income is recorded based on contractual terms of the loan in accordance with Company policy on loans held for investment. None of the loans are 90 days or more past due or on nonaccrual as of: December 31, (In thousands) 2017 2016 Aggregate fair value $ 24,306 $ 15,332 Contractual balance 23,627 14,904 Excess 679 428

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	In 2017, 2016, and 2015, options and warrants to purchase 274,000 131,000 456,000 For the Year Ended December 31 (In thousands, except per share data) 2017 2016 2015 Basic earnings per share Net Income $ 42,865 $ 29,202 $ 22,141 Total weighted average common stock outstanding 42,613 36,872 33,496 Net income per share $ 1.01 $ 0.79 $ 0.66 Diluted earnings per share Net Income $ 42,865 $ 29,202 $ 22,141 Total weighted average common stock outstanding $ 42,613 $ 36,872 $ 33,496 Add: Dilutive effect of employee restricted stock and stock options (See Note J) 737 636 248 Total weighted average diluted stock outstanding 43,350 37,508 33,744 Net income per share $ 0.99 $ 0.78 $ 0.66

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2017
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Information	Twelve Months Ended December 31, (In thousands, except per share data) 2017 2016 Net interest income $ 196,259 $ 170,363 Net income available to common shareholders 51,274 41,594 EPS - basic $ 1.11 $ 0.97 EPS - diluted $ 1.09 $ 0.96
Floridian Financial Group Inc [Member]
Business Acquisition [Line Items]
Schedule of summarizing the purchase price calculation	(In thousands, except per share data) March 11, 2016 Floridian shares exchanged for cash $ 26,699 Number of Floridian common shares outstanding 6,222 Per share exchange ratio 0.5289 Number of shares of common stock issued 3,291 Multiplied by common stock price per share on March 11, 2016 $ 15.47 Value of common stock issued 50,913 Total purchase price $ 77,612
Schedule of Business Acquisitions, by Acquisition	The acquisition was accounted for under the acquisition method in accordance with ASC Topic 805, Business Combinations 32 Measurement March 11, 2016 Period March 11, 2016 (Initially Reported) Adjustments (As Adjusted) (in thousands) Assets: Cash $ 28,243 $ 0 $ 28,243 Investment securities 66,912 95 67,007 Loans, net 268,249 (2,112) 266,137 Fixed assets 7,801 (628) 7,173 Core deposit intangibles 3,375 0 3,375 Goodwill 29,985 1,647 31,632 Other assets 12,879 998 13,877 $ 417,444 $ 0 $ 417,444 Liabilities: Deposits $ 337,341 $ 0 $ 337,341 Other liabilities 2,492 0 2,492 $ 339,833 $ 0 $ 339,833
Fair Value, Assets Measured on Recurring Basis	The table below presents information with respect to the fair value of acquired loans, as well as their unpaid principal balance (“Book Balance”) at acquisition date. March 11, 2016 (In thousands) Book Balance Fair Value Loans: Single family residential real estate $ 38,304 $ 37,367 Commercial real estate 172,531 167,105 Construction/development/land 20,546 18,108 Commercial loans 39,070 37,804 Consumer and other loans 3,385 3,110 Purchased credit-impaired 6,186 2,643 Total acquired loans $ 280,022 $ 266,137
Schedule of Contractually required principal and interest payments	Contractually required principal and interest payments have been adjusted for estimated prepayments. March 11, 2016 (In thousands) Contractually required principal and interest $ 8,031 Non-accretable difference (4,820) Cash flows expected to be collected 3,211 Accretable yield (568) Total purchased credit impaired loans acquired $ 2,643
BMO Harris Bank [Member]
Business Acquisition [Line Items]
Schedule Of Business Combinations Purchase Price Allocation [Table Text Block]	The acquisition was accounted for under the acquisition method in accordance with ASC Topic 805, Business Combinations 13 15 Measurement June 3, 2016 Period June 3, 2016 (Initially Reported) Adjustments (As Adjusted) (in thousands) Assets: Cash from BMO (net of payable) $ 234,094 $ 0 $ 234,094 Loans, net 62,671 0 62,671 Fixed assets 3,715 0 3,715 Core deposit intangibles 5,223 (135) 5,088 Goodwill 7,645 163 7,808 Other assets 952 (28) 924 $ 314,300 $ 0 $ 314,300 Liabilities: Deposits $ 314,248 $ 0 $ 314,248 Other liabilities 52 0 52 $ 314,300 $ 0 $ 314,300 The table below presents information with respect to the fair value of acquired loans, as well as their Book Balance at acquisition date. June 3, 2016 (In thousands) Book Balance Fair Value Loans: Commercial real estate $ 31,564 $ 31,200 Commercial loans 32,479 31,471 Purchased credit-impaired 0 0 Total acquired loans $ 64,043 $ 62,671
Gulf Shore Banc shares Inc [Member]
Business Acquisition [Line Items]
Schedule of summarizing the purchase price calculation	The Company acquired 100 (In thousands, except per share data) April 7, 2017 Shares exchanged for cash $ 8,034 Number of GulfShore Bancshares, Inc. common shares outstanding 5,464 Per share exchange ratio 0.4807 Number of shares of common stock issued 2,627 Multiplied by common stock price per share on April 7, 2017 $ 23.94 Value of common stock issued 62,883 Total purchase price $ 70,917
Schedule of Business Acquisitions, by Acquisition	The acquisition was accounted for under the acquisition method in accordance with ASC Topic 805, Business Combinations 37.1 Measurement April 7, 2017 Period April 7, 2017 Date of acquisition (Initially Reported) Adjustments (As Adjusted) (in thousands) Assets: Cash $ 38,267 $ 0 $ 38,267 Time deposits with other banks 17,273 0 17,273 Investment securities 21 0 21 Loans, net 250,876 0 250,876 Fixed assets 1,307 0 1,307 Other real estate owned 13 0 13 Core deposit intangibles 3,927 0 3,927 Goodwill 37,098 0 37,098 Other assets 8,867 0 8,867 $ 357,649 $ 0 $ 357,649 Liabilities: Deposits $ 285,350 $ 0 $ 285,350 Other liabilities 1,382 0 1,382 $ 286,732 $ 0 $ 286,732
Fair Value, Assets Measured on Recurring Basis	The table below presents information with respect to the fair value of acquired loans, as well as their unpaid principal balance (“Book Balance”) at acquisition date. April 7, 2017 (In thousands) Book Balance Fair Value Loans: Single family residential real estate $ 101,281 $ 99,598 Commercial real estate 106,729 103,905 Construction/development/land 13,175 11,653 Commercial loans 32,137 32,247 Consumer and other loans 3,554 3,473 Purchased credit-impaired 0 0 Total acquired loans $ 256,876 $ 250,876
NorthStar Bank [Member]
Business Acquisition [Line Items]
Schedule of summarizing the purchase price calculation	The Company acquired 100 Under the terms of the definitive agreement, NSBC shareholders received, for each share of NSBC common stock, the combination of $2.40 in cash and 0.5605 shares of Seacoast common stock (based on Seacoast’s closing price of $24.92 per share on October 20, 2017) (In thousands, except per share data) October 20, 2017 Shares exchanged for cash $ 4,701 Number of NorthStar Banking Corporation Common shares outstanding 1,958 Per share exchange ratio 0.5605 Number of shares of common stock issued 1,098 Multiplied by common stock price per share on October 20, 2017 $ 24.92 Value of common stock issued 27,353 Cash paid for NorthStar Banking Corporation vested stock options 801 Total purchase price $ 32,855
Schedule of Business Acquisitions, by Acquisition	Business Combinations 12.4 Date of acquisition October 20, 2017 (in thousands) Assets: Cash $ 5,485 Investment securities 56,123 Loans, net 136,832 Fixed assets 2,637 Core deposit intangibles 1,275 Goodwill 12,404 Other assets 1,522 Total assets $ 216,278 Liabilities: Deposits $ 182,443 Other liabilities 980 Total liabilities $ 183,423
Fair Value, Assets Measured on Recurring Basis	The table below presents information with respect to the fair value of acquired loans, as well as their unpaid principal balance (“Book Balance”) at acquisition date. October 20, 2017 (In thousands) Book Balance Fair Value Loans: Single family residential real estate $ 15,111 $ 15,096 Commercial real estate 73,139 69,554 Construction/development/land 11,706 10,390 Commercial loans 31,200 30,854 Consumer and other loans 6,761 6,645 Purchased Credit Impaired 5,527 4,293 Total acquired loans $ 143,444 $ 136,832
Schedule of Contractually required principal and interest payments	Contractually required principal and interest payments have been adjusted for estimated prepayments. October 20, 2017 (In thousands) Contractually required principal and interest $ 5,596 Non-accretable difference (689) Cash flows expected to be collected 4,907 Accretable yield (614) Total purchased credit-impaired loan acquired $ 4,293
Palm Beach Community Bank [Member]
Business Acquisition [Line Items]
Schedule of summarizing the purchase price calculation	The Company acquired 100 Under the terms of the definitive agreement, PBCB shareholders received, for each share of PBCB common stock, the combination of $6.26 in cash and 0.9240 shares of Seacoast common stock (based on Seacoast’s closing price of $24.31 per share on November 3, 2017). (In thousands, except per share data) November 3, 2017 Shares exchanged for cash $ 15,694 Number of Palm Beach Community Bank Common shares outstanding 2,507 Per share exchange ratio 0.9240 Number of shares of common stock issued 2,316 Multiplied by common stock price per share on November 3, 2017 $ 24.31 Value of common stock issued 56,312 Total purchase price $ 72,006
Schedule of Business Acquisitions, by Acquisition	The acquisition was accounted for under the acquisition method in accordance with ASC Topic 805, Business Combinations 33.4 Date of acquisition November 3, 2017 (In thousands) Assets: Cash $ 9,301 Investment securities 22,098 Loans, net 272,090 Fixed assets 7,641 Core deposit intangibles 2,523 Goodwill 33,428 Other assets 9,909 Total assets $ 356,990 Liabilities: Deposits $ 268,633 Other liabilities 16,351 Total liabilities $ 284,984
Fair Value, Assets Measured on Recurring Basis	The table below presents information with respect to the fair value of acquired loans, as well as their Book Balance at acquisition date. November 3, 2017 (In thousands) Book Balance Fair Value Loans: Single family residential real estate $ 30,153 $ 30,990 Commercial real estate 134,705 132,654 Construction/development/land 69,686 67,425 Commercial loans 36,076 37,083 Consumer and other loans 179 172 Purchased Credit Impaired 4,768 3,766 Total acquired loans $ 275,567 $ 272,090
Schedule of Contractually required principal and interest payments	Contractually required principal and interest payments have been adjusted for estimated prepayments. (In thousands) November 3, 2017 Contractually required principal and interest $ 4,768 Non-accretable difference (1,002) Cash flows expected to be collected 3,766 Accretable yield 0 Total purchased credit-impaired loan acquired $ 3,766

Significant Accounting Polici45

Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 22, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Line Items]
Modified loan terms			6 months
Loan And Leases Due Period For Discontinuation Of Interest Accrual			90 days
Consumer Loans Charged Off Period			120 days
Net Operating Loss Carryforward Limit Percentage	80.00%
Effective Income Tax Rate Reconciliation, Deduction, Net Interest Expenses	30.00%
Deferred Income Tax Expense (Benefit)			$ 35,827	$ 14,206	$ 12,888
Other Comprehensive Income Loss Reclassification Adjustment Of Disappropriate Tax Effects Upon Adoption Of New Accounting Prounouncement From AOCI To Retained Earnings			$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			35.00%	35.00%	35.00%
Scenario, Plan [Member]
Accounting Policies [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%
Building [Member] | Maximum [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life			40 years
Building [Member] | Minimum [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life			25 years
Leasehold Improvements [Member] | Maximum [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life			25 years
Leasehold Improvements [Member] | Minimum [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life			5 years
Furniture and Equipment [Member] | Maximum [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life			12 years
Furniture and Equipment [Member] | Minimum [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life			3 years

Cash, Dividend and Loan Restr46

Cash, Dividend and Loan Restrictions - Additional Information (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Dividend and Loan Restrictions [Line Items]
Average Reserve Balance Maintained With Federal Reserve Bank	$ 500,000
Maximum Amount Available For Transfer Of Loans	69,900,000
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments without Regulatory Approval	87,700,000
Due from Affiliates	$ 0	$ 0	$ 0

Securities - Additional Informa

Securities - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Proceeds from Sale of Available-for-sale Securities, Debt		$ 235,613	$ 40,421	$ 60,314
Available-for-sale Securities, Gross Realized Gains		1,600	500	700
Available-for-sale Securities, Gross Realized Losses		$ 1,500	100	500
Collateral Underlying Mortgage Investments Terms		30- and 15-year fixed and 10/1 adjustable rate mortgage
Federal Home Loan Bank Stock and Federal Reserve Bank Stock		$ 32,500
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		773,010	862,873
Accumulated unrealized losses		12,831	18,443
Securities Available For Sale Transferred To Held-To-Maturity					$ 158,800
Available For Sale Securities Transferred To Held To Maturity Securities Unrealized Gain Loss					$ 3,100
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		332,677	664,476
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		2,290	13,451
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		440,333	198,397
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		$ 10,541	$ 4,992
Common Stock, Shares, Outstanding		46,917,735	38,021,835
Debt Instrument, Convertible, Conversion Price		$ 1.6483
Number of shares acquired	200,000
Payments to Acquire Marketable Securities		$ 6,180	$ 0	0
Gain (Loss) on Sale of Securities, Net		$ 15,153	0	$ 0
Common Class B [Member]
Schedule of Available-for-sale Securities [Line Items]
Common Stock, Shares, Outstanding		11,330
Common Class A [Member]
Schedule of Available-for-sale Securities [Line Items]
Stock Issued During Period, Shares, Conversion of Convertible Securities		18,675
Available-for-sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		$ 1,200
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		22,900	22,800
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		200	$ 400
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		400
Carrying Amount [Member] | Repurchase Agreement [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities pledged as collateral		216,100
Carrying Amount [Member] | United States Treasury Deposits and Other Public and Trust Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities pledged as collateral		169,000
Collateralized Loan Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		718,400
Accumulated unrealized losses		12,200
Private Collateralized Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		20,800
Accumulated unrealized losses		$ 300

Securities - Amortized Cost and

Securities - Amortized Cost and Fair Value of Securities Available for Sale and Held for Investment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	$ 960,220	$ 960,809
Gross Unrealized Gains, Available for Sale	4,202	3,767
Gross Unrealized Losses, Available for Sale	(8,618)	(14,073)
Fair Value, Available for Sale	955,804	950,503
Gross Amortized Cost, Held for Investment Securities	416,863	372,498
Gross Unrealized Gains, Held for Investment Securities	1,819	1,753
Gross Unrealized Losses, Held for Investment Securities	(4,212)	(4,370)
Fair Value, Held for Investment Securities	414,470	369,881
U.S. Treasury Securities and obligations of U.S. Government Sponsored Entities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	9,475	12,073
Gross Unrealized Gains, Available for Sale	274	255
Gross Unrealized Losses, Available for Sale	(5)	0
Fair Value, Available for Sale	9,744	12,328
Mortgage-backed securities of U.S. Government Sponsored Entities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	318,771	287,726
Gross Unrealized Gains, Available for Sale	891	585
Gross Unrealized Losses, Available for Sale	(3,306)	(4,823)
Fair Value, Available for Sale	316,356	283,488
Gross Amortized Cost, Held for Investment Securities	172,261	159,941
Gross Unrealized Gains, Held for Investment Securities	746	704
Gross Unrealized Losses, Held for Investment Securities	(1,392)	(1,243)
Fair Value, Held for Investment Securities	171,615	159,402
Collateralized Mortgage Obligations Of US Government Sponsored Entities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	235,466	238,805
Gross Unrealized Gains, Available for Sale	272	314
Gross Unrealized Losses, Available for Sale	(4,694)	(5,065)
Fair Value, Available for Sale	231,044	234,054
Gross Amortized Cost, Held for Investment Securities	181,280	147,208
Gross Unrealized Gains, Held for Investment Securities	56	386
Gross Unrealized Losses, Held for Investment Securities	(2,767)	(2,630)
Fair Value, Held for Investment Securities	178,569	144,964
Commercial mortgage backed securities of U.S. Government Sponsored Entities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	16,210	22,351
Gross Unrealized Gains, Available for Sale	165	222
Gross Unrealized Losses, Available for Sale	(34)	(28)
Fair Value, Available for Sale	16,341	22,545
Gross Amortized Cost, Held for Investment Securities	17,462	17,375
Gross Unrealized Gains, Held for Investment Securities	705	233
Gross Unrealized Losses, Held for Investment Securities	0	(74)
Fair Value, Held for Investment Securities	18,167	17,534
Private mortgage backed securities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	18,056	32,780
Gross Unrealized Gains, Available for Sale	384	0
Gross Unrealized Losses, Available for Sale	0	(791)
Fair Value, Available for Sale	18,440	31,989
Gross Amortized Cost, Held for Investment Securities		6,427
Gross Unrealized Gains, Held for Investment Securities		0
Gross Unrealized Losses, Held for Investment Securities		(109)
Fair Value, Held for Investment Securities	0	6,318
Private mortgage backed securities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	47,045	67,542
Gross Unrealized Gains, Available for Sale	605	563
Gross Unrealized Losses, Available for Sale	(285)	(816)
Fair Value, Available for Sale	47,365	67,289
Gross Amortized Cost, Held for Investment Securities	5,337
Gross Unrealized Gains, Held for Investment Securities	9
Gross Unrealized Losses, Held for Investment Securities	(53)
Fair Value, Held for Investment Securities	5,293
Collateralized loan obligations [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	263,579	124,716
Gross Unrealized Gains, Available for Sale	798	838
Gross Unrealized Losses, Available for Sale	(68)	(665)
Fair Value, Available for Sale	264,309	124,889
Gross Amortized Cost, Held for Investment Securities	40,523	41,547
Gross Unrealized Gains, Held for Investment Securities	303	430
Gross Unrealized Losses, Held for Investment Securities	0	(314)
Fair Value, Held for Investment Securities	40,826	41,663
Obligations of state and political subdivisions [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	45,118	63,161
Gross Unrealized Gains, Available for Sale	813	622
Gross Unrealized Losses, Available for Sale	(70)	(895)
Fair Value, Available for Sale	45,861	62,888
Corporate and other debt securities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	6,500	74,121
Gross Unrealized Gains, Available for Sale	0	257
Gross Unrealized Losses, Available for Sale	(156)	(517)
Fair Value, Available for Sale	6,344	73,861
Fair Value, Held for Investment Securities	$ 0
Private commercial mortgage backed securities [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale		37,534
Gross Unrealized Gains, Available for Sale		111
Gross Unrealized Losses, Available for Sale		(473)
Fair Value, Available for Sale		$ 37,172

Securities - Amortized Cost a49

Securities - Amortized Cost and Fair Value of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	$ 416,863	$ 372,498
Held to Maturity, Fair Value, Total	414,470	369,881
Available for Sale, Amortized Cost, Total	960,220
Available for Sale, Fair Value, Total	955,804	950,503
Collateralized Loan Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Due in less than one year	0
Held for Investment, Fair Value, Due in less than one year	0
Available for Sale Amortized Cost, Due in less than one year	6,248
Available for Sale, Fair Value, Due in less than one year	6,473
Held for Investment, Amortized Cost, Due after one year through five years	3,600
Held for Investment, Fair Value, Due after one year through five years	3,607
Available for Sale, Amortized Cost, Due after one year through five years	42,448
Available for Sale, Fair Value, Due after one year through five years	42,616
Held for Investment, Amortized Cost, Due after five years through ten years	36,923
Held for Investment, Fair Value, Due after five years through ten years	37,219
Available for Sale, Amortized Cost, Due after five years through ten years	256,306
Available for Sale, Fair Value, Due after five years through ten years	257,449
Held for Investment, Amortized Cost, Due after ten years	0
Held for Investment, Fair Value, Due after ten years	0
Available for Sale, Amortized Cost, Due after ten years	13,170
Available for Sale, Fair Value, Due after ten years	13,376
Held to Maturity, Amortized Cost, Total	40,523
Held to Maturity, Fair Value, Total	40,826
Available for Sale, Amortized Cost, Total	318,172
Available for Sale, Fair Value, Total	319,914
Mortgage-backed securities of U.S. Government Sponsored Entities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	172,261
Held to Maturity, Fair Value, Total	171,615	159,402
Available for Sale, Amortized Cost, Total	318,771
Available for Sale, Fair Value, Total	316,356	283,488
Collateralized Mortgage Obligations Of US Government Sponsored Entities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	181,279
Held to Maturity, Fair Value, Total	178,569	144,964
Available for Sale, Amortized Cost, Total	235,466
Available for Sale, Fair Value, Total	231,044	234,054
Commercial mortgage backed securities of U.S. Government Sponsored Entities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	17,463
Held to Maturity, Fair Value, Total	18,167	17,534
Available for Sale, Amortized Cost, Total	16,210
Available for Sale, Fair Value, Total	16,341	22,545
Private mortgage backed securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	0
Held to Maturity, Fair Value, Total	0	6,318
Available for Sale, Amortized Cost, Total	18,056
Available for Sale, Fair Value, Total	18,440	31,989
Private collateralized mortgage obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	5,337
Held to Maturity, Fair Value, Total	5,293
Available for Sale, Amortized Cost, Total	47,045
Available for Sale, Fair Value, Total	47,365	67,289
Corporate and other debt securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	0
Held to Maturity, Fair Value, Total	0
Available for Sale, Amortized Cost, Total	6,500
Available for Sale, Fair Value, Total	$ 6,344	$ 73,861

Securities - Schedule of Unreal

Securities - Schedule of Unrealized Loss and Fair Value on Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value
Less than 12 months	$ 332,677	$ 664,476
12 months or longer	440,333	198,397
Total	773,010	862,873
Unrealized Losses
Less than 12 months	(2,290)	(13,451)
12 months or longer	(10,541)	(4,992)
Total	(12,831)	(18,443)
Collateralized Loan Obligations [Member]
Fair Value
Less than 12 months	14,933	8,152
12 months or longer	0	51,694
Total	14,933	59,846
Unrealized Losses
Less than 12 months	(68)	(41)
12 months or longer	0	(938)
Total	(68)	(979)
U.S. Treasury securities and obligations of U.S. Government Sponsored Entities [Member]
Fair Value
Less than 12 months	1,107
12 months or longer	0
Total	1,107
Unrealized Losses
Less than 12 months	(5)
12 months or longer	0
Total	(5)
Mortgage-backed securities of U.S. Government Sponsored Entities [Member]
Fair Value
Less than 12 months	123,195	327,759
12 months or longer	213,590	5,387
Total	336,785	333,146
Unrealized Losses
Less than 12 months	(515)	(5,991)
12 months or longer	(4,183)	(75)
Total	(4,698)	(6,066)
Collateralized Mortgage Obligations Of US Government Sponsored Entities [Member]
Fair Value
Less than 12 months	176,452	234,175
12 months or longer	199,086	58,912
Total	375,538	293,087
Unrealized Losses
Less than 12 months	(1,507)	(5,599)
12 months or longer	(5,955)	(2,096)
Total	(7,462)	(7,695)
Commercial mortgage backed securities of U.S. Government Sponsored Entities [Member]
Fair Value
Less than 12 months	5,076	7,934
12 months or longer	1,049	0
Total	6,125	7,934
Unrealized Losses
Less than 12 months	(25)	(102)
12 months or longer	(9)	0
Total	(34)	(102)
Private mortgage backed securities [Member]
Fair Value
Less than 12 months	0	0
12 months or longer	0	36,848
Total	0	36,848
Unrealized Losses
Less than 12 months	0	0
12 months or longer	0	(900)
Total	0	(900)
Private collateralized mortgage obligations [Member]
Fair Value
Less than 12 months	0	1,460
12 months or longer	20,744	38,417
Total	20,744	39,877
Unrealized Losses
Less than 12 months	0	0
12 months or longer	(338)	(816)
Total	(338)	(816)
Obligations of state and political subdivisions [Member]
Fair Value
Less than 12 months	5,414	39,321
12 months or longer	5,864	0
Total	11,278	39,321
Unrealized Losses
Less than 12 months	(14)	(895)
12 months or longer	(56)	0
Total	(70)	(895)
Corporate and other debt securities [member]
Fair Value
Less than 12 months	6,500	33,008
12 months or longer	0	0
Total	6,500	33,008
Unrealized Losses
Less than 12 months	(156)	(517)
12 months or longer	0	0
Total	$ (156)	(517)
Private commercial mortgage backed securities [Member]
Fair Value
Less than 12 months		12,667
12 months or longer		7,139
Total		19,806
Unrealized Losses
Less than 12 months		(306)
12 months or longer		(167)
Total		$ (473)

Loans - Additional Information

Loans - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Reduction in interest income	$ 700,000	$ 700,000	$ 600,000
Loans and Leases Receivable, Related Parties	1,100,000	2,100,000
Loans and Leases Receivable, Related Parties, Additions	0
Loans Pledged as Collateral	211,000,000	415,000,000
Troubled Debt Restructuring Outstanding	15,600,000	17,700,000
Impaired Financing Receivable, Average Recorded Investment	30,900,000	31,200,000	38,500,000
Loans and Leases Receivable, Impaired, Troubled Debt, Interest Income	1,500,000	1,600,000	900,000
Loans and Leases Receivable, Impaired, Interest Income Recognized, Change in Present Value Attributable to Passage of Time	300,000	200,000	$ 200,000
Commercial and Financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Operating Lease, Liability	30,300,000	0
PCI Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Deferred Costs, Noncurrent	$ 11,500,000	$ 10,600,000

Loans - Information Relating to

Loans - Information Relating to Loans (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[1]	$ 3,817,377	$ 2,879,536
Commercial and financial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[2]	606,014	370,589
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		189,436	154,452
Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		343,125	160,116
Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		1,639,992	1,357,592
Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		1,038,810	836,787
Portfolio Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[1]	2,922,609	2,425,850
Portfolio Loans [Member] | Commercial and financial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[2]	512,430	308,731
Portfolio Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		178,826	153,434
Portfolio Loans [Member] | Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		215,315	137,480
Portfolio Loans [Member] | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		1,170,618	1,041,915
Portfolio Loans [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		845,420	784,290
PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[1]	17,417	12,996
PCI Loans [Member] | Commercial and financial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[2]	894	941
PCI Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		0	0
PCI Loans [Member] | Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		1,121	114
PCI Loans [Member] | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		9,776	11,257
PCI Loans [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		5,626	684
PULs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[1]	877,351	440,690
PULs [Member] | Commercial and financial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[2]	92,690	60,917
PULs [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		10,610	1,018
PULs [Member] | Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		126,689	22,522
PULs [Member] | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		459,598	304,420
PULs [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		$ 187,764	$ 51,813
[1]	Net loan balances at December 31, 2017 and 2016 include deferred costs of $11.5 million and $10.6 million, respectively.
[2]	Commercial and financial includes leases of $30.3 million and $0 million as of December 31, 2017 and 2016, respectively.

Loans - Contractual Aging of Re

Loans - Contractual Aging of Recorded Investment in Past Due Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 3,788,998	$ 2,857,695
Nonaccrual	19,524	18,071
Total Financing Receivables	3,817,377	2,879,536
Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	8,082	2,281
Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	773	1,489
Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Portfolio Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,903,109	2,412,629
Nonaccrual	12,569	11,023
Total Financing Receivables	2,922,609	2,425,850
Portfolio Loans [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,165,738	1,039,882
Nonaccrual	1,690	1,784
Total Financing Receivables	1,170,618	1,041,915
Portfolio Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	178,676	153,176
Nonaccrual	98	170
Total Financing Receivables	178,826	153,434
Portfolio Loans [Member] | Commerical and financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	507,501	308,652
Nonaccrual	2,127	49
Total Financing Receivables	512,430	308,731
Portfolio Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	6,245	1,707
Portfolio Loans [Member] | Accruing 30-59 Days Past Due | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	2,605	78
Portfolio Loans [Member] | Accruing 30-59 Days Past Due | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	52	29
Portfolio Loans [Member] | Accruing 30-59 Days Past Due | Commerical and financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	2,776	30
Portfolio Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	686	491
Portfolio Loans [Member] | Accruing 60-89 Days Past Due | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	585	171
Portfolio Loans [Member] | Accruing 60-89 Days Past Due | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	59
Portfolio Loans [Member] | Accruing 60-89 Days Past Due | Commerical and financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	26	0
Portfolio Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Portfolio Loans [Member] | Accruing Greater Than 90 Days | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Portfolio Loans [Member] | Accruing Greater Than 90 Days | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Portfolio Loans [Member] | Accruing Greater Than 90 Days | Commerical and financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Unimpaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	874,028	436,540
Nonaccrual	2,041	2,763
Total Financing Receivables	877,351	440,690
Purchased Unimpaired Loans [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	457,899	302,318
Nonaccrual	720	1,272
Total Financing Receivables	459,598	304,420
Purchased Unimpaired Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	10,610	981
Nonaccrual	0	0
Total Financing Receivables	10,610	1,018
Purchased Unimpaired Loans [Member] | Commerical and financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	92,315	60,353
Nonaccrual	321	197
Total Financing Receivables	92,690	60,917
Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,195	574
Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	979	345
Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	37
Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due | Commerical and financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	54	39
Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	87	813
Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	485
Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due | Commerical and financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	328
Purchased Unimpaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Unimpaired Loans [Member] | Accruing Greater Than 90 Days | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Unimpaired Loans [Member] | Accruing Greater Than 90 Days | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Unimpaired Loans [Member] | Accruing Greater Than 90 Days | Commerical and financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	11,861	8,526
Nonaccrual	4,914	4,285
Total Financing Receivables	17,417	12,996
Purchased Credit Impaired Loans [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	9,352	6,972
Nonaccrual	424	4,285
Total Financing Receivables	9,776	11,257
Purchased Credit Impaired Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	0	0
Nonaccrual	0	0
Total Financing Receivables	0	0
Purchased Credit Impaired Loans [Member] | Commerical and financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	844	941
Nonaccrual	50	0
Total Financing Receivables	894	941
Purchased Credit Impaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	642	0
Purchased Credit Impaired Loans [Member] | Accruing 30-59 Days Past Due | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Credit Impaired Loans [Member] | Accruing 30-59 Days Past Due | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Credit Impaired Loans [Member] | Accruing 30-59 Days Past Due | Commerical and financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Credit Impaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	185
Purchased Credit Impaired Loans [Member] | Accruing 60-89 Days Past Due | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Credit Impaired Loans [Member] | Accruing 60-89 Days Past Due | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Credit Impaired Loans [Member] | Accruing 60-89 Days Past Due | Commerical and financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Credit Impaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Credit Impaired Loans [Member] | Accruing Greater Than 90 Days | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Credit Impaired Loans [Member] | Accruing Greater Than 90 Days | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Credit Impaired Loans [Member] | Accruing Greater Than 90 Days | Commerical and financial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Portfolio Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	215,077	137,042
Nonaccrual	238	438
Total Financing Receivables	215,315	137,480
Construction and land development [Member] | Portfolio Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Portfolio Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Portfolio Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Purchased Unimpaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	126,655	22,490
Nonaccrual	0	32
Total Financing Receivables	126,689	22,522
Construction and land development [Member] | Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	34	0
Construction and land development [Member] | Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Purchased Unimpaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,121	114
Nonaccrual	0	0
Total Financing Receivables	1,121	114
Construction and land development [Member] | Purchased Credit Impaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Purchased Credit Impaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Purchased Credit Impaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Residential real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	1,038,810	836,787
Residential real estate [Member] | Portfolio Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	836,117	773,877
Nonaccrual	8,416	8,582
Total Financing Receivables	845,420	784,290
Residential real estate [Member] | Portfolio Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	812	1,570
Residential real estate [Member] | Portfolio Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	75	261
Residential real estate [Member] | Portfolio Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Residential real estate [Member] | Purchased Unimpaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	186,549	50,398
Nonaccrual	1,000	1,262
Total Financing Receivables	187,764	51,813
Residential real estate [Member] | Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	128	153
Residential real estate [Member] | Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	87	0
Residential real estate [Member] | Purchased Unimpaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Residential real estate [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	544	499
Nonaccrual	4,440	0
Total Financing Receivables	5,626	684
Residential real estate [Member] | Purchased Credit Impaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	642	0
Residential real estate [Member] | Purchased Credit Impaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	185
Residential real estate [Member] | Purchased Credit Impaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	$ 0	$ 0

Loans - Risk Category, Class of

Loans - Risk Category, Class of Loans and Recorded Investment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 3,817,377	$ 2,879,536
Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	343,125	160,116
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,639,992	1,357,593
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,038,810	836,787
Commercial and Financial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	606,014	370,589
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	189,436	154,452
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,722,027	2,803,241
Pass [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	328,127	148,607
Pass [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,586,932	1,324,685
Pass [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,023,925	811,934
Pass [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	593,689	364,241
Pass [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	189,354	153,774
Special mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	47,545	28,017
Special mention [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	10,414	5,037
Special mention [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	29,273	17,184
Special mention [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,621	1,780
Special mention [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,237	3,949
Special mention [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	67
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	47,494	48,279
Substandard [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,584	6,472
Substandard [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	23,787	15,724
Substandard [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	10,203	23,073
Substandard [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	8,838	2,399
Substandard [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	82	611
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	311	0
Doubtful [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	0
Doubtful [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	0
Doubtful [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	61	0
Doubtful [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	250	0
Doubtful [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 0	$ 0

Loans - Summarizes Changes in T

Loans - Summarizes Changes in Total Contractually Required Principal and Interest Cash Payments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Contractually Required Principal And Interest Cash Payments Changes [Line Items]
Beginning balance	$ 3,807	$ 2,610	$ 1,192
Additions	763	2,052	702
Deletions	(11)	(15)	(357)
Accretion	(1,647)	(1,734)	(601)
Reclassifications from non-accretable difference	787	894	1,674
Ending Balance	$ 3,699	$ 3,807	$ 2,610

Loans - Modified Loans (Details

Loans - Modified Loans (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Number	Dec. 31, 2016USD ($)Number
Financing Receivable, Modifications [Line Items]
Number of Contracts | Number	2	5
Pre-Modification Outstanding Recorded Investment	$ 67	$ 1,189
Post-Modification Outstanding Recorded Investment	61	1,037
Valuation Allowance Recorded	$ 6	$ 152
Construction and Land Development [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Number	1	1
Pre-Modification Outstanding Recorded Investment	$ 52	$ 20
Post-Modification Outstanding Recorded Investment	46	18
Valuation Allowance Recorded	$ 6	$ 2
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Number	1	4
Pre-Modification Outstanding Recorded Investment	$ 15	$ 1,169
Post-Modification Outstanding Recorded Investment	15	1,019
Valuation Allowance Recorded	$ 0	$ 150

Loans - Company's Recorded Inve

Loans - Company's Recorded Investments in Impaired Loans and the Related Valuation Allowances (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Recorded Investment
Total Impaired Loans	$ 30,291	$ 32,718
Unpaid Principal Balance
Total Impaired Loans	35,519	39,157
Related Valuation Allowance
Total Impaired Loans	2,402	2,454
Construction and Land Development [Member]
Recorded Investment
Impaired Loans with No Related Allowance Recorded	223	226
Impaired Loans with an Allowance Recorded	251	51
Total Impaired Loans	474	277
Unpaid Principal Balance
Impaired Loans with No Related Allowance Recorded	510	321
Impaired Loans with an Allowance Recorded	264	51
Total Impaired Loans	774	372
Related Valuation Allowance
Impaired Loans with No Related Allowance Recorded	0	0
Impaired Loans with an Allowance Recorded	23	0
Total Impaired Loans	23	0
Commercial Real Estate [Member]
Recorded Investment
Impaired Loans with No Related Allowance Recorded	3,475	3,267
Impaired Loans with an Allowance Recorded	4,780	6,937
Total Impaired Loans	8,255	10,204
Unpaid Principal Balance
Impaired Loans with No Related Allowance Recorded	4,873	4,813
Impaired Loans with an Allowance Recorded	4,780	6,949
Total Impaired Loans	9,653	11,762
Related Valuation Allowance
Impaired Loans with No Related Allowance Recorded	0	0
Impaired Loans with an Allowance Recorded	195	395
Total Impaired Loans	195	395
Residential Real Estate [Member]
Recorded Investment
Impaired Loans with No Related Allowance Recorded	10,272	9,706
Impaired Loans with an Allowance Recorded	8,448	12,332
Total Impaired Loans	18,720	22,038
Unpaid Principal Balance
Impaired Loans with No Related Allowance Recorded	15,063	14,136
Impaired Loans with an Allowance Recorded	8,651	12,681
Total Impaired Loans	23,714	26,817
Related Valuation Allowance
Impaired Loans with No Related Allowance Recorded	0	0
Impaired Loans with an Allowance Recorded	1,091	2,059
Total Impaired Loans	1,091	2,059
Commercial And Financial [Member]
Recorded Investment
Impaired Loans with No Related Allowance Recorded	19	199
Impaired Loans with an Allowance Recorded	2,436	0
Total Impaired Loans	2,455	199
Unpaid Principal Balance
Impaired Loans with No Related Allowance Recorded	29	206
Impaired Loans with an Allowance Recorded	883	0
Total Impaired Loans	912	206
Related Valuation Allowance
Impaired Loans with No Related Allowance Recorded	0	0
Impaired Loans with an Allowance Recorded	1,050	0
Total Impaired Loans	1,050	0
Consumer [Member]
Recorded Investment
Impaired Loans with No Related Allowance Recorded	105	0
Impaired Loans with an Allowance Recorded	282	0
Total Impaired Loans	387	0
Unpaid Principal Balance
Impaired Loans with No Related Allowance Recorded	180	0
Impaired Loans with an Allowance Recorded	286	0
Total Impaired Loans	466	0
Related Valuation Allowance
Impaired Loans with No Related Allowance Recorded	0	0
Impaired Loans with an Allowance Recorded	43	0
Total Impaired Loans	$ 43	$ 0

Allowance for Loan Losses - Add

Allowance for Loan Losses - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Modifications [Line Items]
Provision for Loan, Lease, and Other Losses	$ 5,648	$ 2,411	$ 2,644
Allowance for Loan and Lease Losses, Write-offs	4,102	1,144	3,380
Allowance for Loan and Lease Loss, Recovery of Bad Debts	2,495	3,236	3,012
Purchased Unimpaired Loans [Member]
Financing Receivable, Modifications [Line Items]
Provision for Loan, Lease, and Other Losses	(400)		(1,300)
Allowance for Loan and Lease Losses, Write-offs			$ 1,200
Allowance for Loan and Lease Loss, Recovery of Bad Debts	1,000
Loans [Member] | Bank shares, Inc [Member]
Financing Receivable, Modifications [Line Items]
Assets, Fair Value Adjustment	$ 17,500	$ 13,700
Fair value adjustment Percent	2.00%	3.11%

Allowance for Loan Losses - Act

Allowance for Loan Losses - Activity in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Loan Losses:
Beginning Balance	$ 23,400	$ 19,128	$ 17,007
Provision for Loan Losses	5,648	2,411	2,644
Charge-Offs	(4,102)	(1,144)	(3,380)
Recoveries	2,495	3,236	3,012
TDR Allowance Adjustments	(319)	(231)	(218)
Ending Balance	27,122	23,400	19,128
Construction and land developments [Member]
Allowance for Loan Losses:
Beginning Balance	1,219	1,151	722
Provision for Loan Losses	(471)	(150)	1,296
Charge-Offs	0	0	(1,271)
Recoveries	896	226	404
TDR Allowance Adjustments	(2)	(8)	43
Ending Balance	1,642	1,219	1,151
Commercial real estates [Member]
Allowance for Loan Losses:
Beginning Balance	9,273	6,756	4,528
Provision for Loan Losses	(264)	2,599	2,010
Charge-Offs	(407)	(256)	(263)
Recoveries	747	306	700
TDR Allowance Adjustments	(64)	(132)	(69)
Ending Balance	9,285	9,273	6,756
Residential real estates [Member]
Allowance for Loan Losses:
Beginning Balance	7,483	8,057	9,784
Provision for Loan Losses	125	(1,069)	(2,208)
Charge-Offs	(569)	(205)	(779)
Recoveries	336	786	1,260
TDR Allowance Adjustments	(244)	(86)	(150)
Ending Balance	7,131	7,483	8,057
Commercial and financial [Member]
Allowance for Loan Losses:
Beginning Balance	3,636	2,042	1,179
Provision for Loan Losses	5,304	224	1,058
Charge-Offs	(1,869)	(439)	(726)
Recoveries	226	1,809	531
TDR Allowance Adjustments	0	0	(6)
Ending Balance	7,297	3,636	2,042
Consumers [Member]
Allowance for Loan Losses:
Beginning Balance	1,789	1,122	794
Provision for Loan Losses	954	807	552
Charge-Offs	(1,257)	(244)	(341)
Recoveries	290	109	117
TDR Allowance Adjustments	(9)	(5)	(36)
Ending Balance	$ 1,767	$ 1,789	$ 1,122

Allowance for Loan Losses - Loa

Allowance for Loan Losses - Loan Portfolio and Related Allowance (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Recorded Investment
Individually Evaluated for Impairment	$ 30,291	$ 32,718
Collectively Evaluated for Impairment	24,720	20,946
Total	3,799,961	2,853,544
Associated Allowance
Individually Evaluated for Impairment	2,402	2,454
Collectively Evaluated for Impairment	3,769,670	2,820,826
Total	27,122	23,400
PCI Loans [Member]
Recorded Investment
Individually Evaluated for Impairment	17,417	12,996
Associated Allowance
Individually Evaluated for Impairment	0	0
Construction and Land Development [Member]
Recorded Investment
Individually Evaluated for Impairment	474	277
Collectively Evaluated for Impairment	1,619	1,219
Total	342,004	160,116
Associated Allowance
Individually Evaluated for Impairment	23	0
Collectively Evaluated for Impairment	341,530	159,839
Total	1,642	1,219
Construction and Land Development [Member] | PCI Loans [Member]
Recorded Investment
Individually Evaluated for Impairment	1,121	114
Associated Allowance
Individually Evaluated for Impairment	0	0
Commercial Real Estate [Member]
Recorded Investment
Individually Evaluated for Impairment	8,255	10,204
Collectively Evaluated for Impairment	9,090	8,878
Total	1,630,215	1,334,480
Associated Allowance
Individually Evaluated for Impairment	195	395
Collectively Evaluated for Impairment	1,621,960	1,324,276
Total	9,285	9,273
Commercial Real Estate [Member] | PCI Loans [Member]
Recorded Investment
Individually Evaluated for Impairment	9,776	11,257
Associated Allowance
Individually Evaluated for Impairment	0	0
Residential Real Estate [Member]
Recorded Investment
Individually Evaluated for Impairment	18,720	22,038
Collectively Evaluated for Impairment	6,040	5,424
Total	1,033,185	835,789
Associated Allowance
Individually Evaluated for Impairment	1,091	2,059
Collectively Evaluated for Impairment	1,014,465	813,751
Total	7,131	7,483
Residential Real Estate [Member] | PCI Loans [Member]
Recorded Investment
Individually Evaluated for Impairment	5,626	684
Associated Allowance
Individually Evaluated for Impairment	0	0
Commercial And Financial [Member]
Recorded Investment
Individually Evaluated for Impairment	2,455	199
Collectively Evaluated for Impairment	6,247	3,636
Total	605,121	368,707
Associated Allowance
Individually Evaluated for Impairment	1,050	0
Collectively Evaluated for Impairment	602,666	368,508
Total	7,297	3,636
Commercial And Financial [Member] | PCI Loans [Member]
Recorded Investment
Individually Evaluated for Impairment	894	941
Associated Allowance
Individually Evaluated for Impairment	0	0
Consumer [Member]
Recorded Investment
Individually Evaluated for Impairment	387	0
Collectively Evaluated for Impairment	1,724	1,789
Total	189,436	154,452
Associated Allowance
Individually Evaluated for Impairment	43	0
Collectively Evaluated for Impairment	189,049	154,452
Total	1,767	1,789
Consumer [Member] | PCI Loans [Member]
Recorded Investment
Individually Evaluated for Impairment	0	0
Associated Allowance
Individually Evaluated for Impairment	$ 0	$ 0

Bank Premises and Equipment - S

Bank Premises and Equipment - Summary of Bank Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Cost	$ 112,787	$ 101,843
Accumulated Depreciation & Amortization	(45,904)	(43,159)
Net Carrying Value	66,883	58,684
Premises [Member]
Property, Plant and Equipment [Line Items]
Cost	78,255	71,562
Accumulated Depreciation & Amortization	(24,045)	(22,969)
Net Carrying Value	54,210	48,593
Furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Cost	34,532	30,281
Accumulated Depreciation & Amortization	(21,859)	(20,190)
Net Carrying Value	$ 12,673	$ 10,091

Bank Premises and Equipment -62

Bank Premises and Equipment - Summary of Bank Premises and Equipment (Parenthetical) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Land	$ 18,269	$ 14,773

Goodwill and Acquired Intangi63

Goodwill and Acquired Intangible Assets - Additional Information (Details) $ in Millions	Dec. 31, 2017USD ($)
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	$ 4
Finite-Lived Intangible Assets, Amortization Expense, Year Four	2.7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill, Total	0.2
Finite-Lived Intangible Assets, Amortization Expense, Year Two	4
Finite-Lived Intangible Assets, Amortization Expense, Year Three	3.9
Finite-Lived Intangible Assets, Amortization Expense, Year Five	$ 2.2

Goodwill and Acquired Intangi64

Goodwill and Acquired Intangible Assets - Changes In Carrying Amount Of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Beginning of year	$ 64,649	$ 25,211	$ 25,309
Changes from business combinations	82,929	39,438	0
Other	0	0	(98)
Total Goodwill	$ 147,578	$ 64,649	$ 25,211

Goodwill and Acquired Intangi65

Goodwill and Acquired Intangible Assets - Gross Carrying Amount and Accumulated Amortization of Intangible Asset (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Remaining Average Amortization Period for CDI	63 months	64 months	67 months
Beginning of year	$ 14,572	$ 8,594	$ 7,454
Acquired CDI	7,726	8,464	2,564
Amortization expense	(3,361)	(2,486)	(1,424)
End of year	$ 19,099	$ 14,572	$ 8,594

Goodwill and Acquired Intangi66

Goodwill and Acquired Intangible Assets - Acquired Intangible Assets Consist of Core Deposit Intangibles (Details) - Deposit Base [Member] - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 26,522	$ 18,796
Accumulated Amortization	$ (7,585)	$ (4,224)

Borrowings - Additional Informa

Borrowings - Additional Information (Details) - USD ($) $ in Thousands

Apr. 07, 2016

Nov. 27, 2007

Sep. 15, 2007

Jun. 29, 2007

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Jan. 30, 2018

Nov. 03, 2017

Oct. 20, 2017

Dec. 16, 2005

Mar. 31, 2005

Debt Instrument [Line Items]

Securities Sold Under Agreements To Repurchase Period Description

overnight to seven days

Junior subordinated debentures private sales

$ 12,000

Trust Preferred Securities Redemption Description

The trust preferred securities have original maturities of thirty years, and may be redeemed without penalty, upon approval of the Federal Reserve or upon occurrence of certain events affecting their tax or regulatory capital treatment

Junior subordinated deferrable interest notes issued

$ 12,400

$ 12,400

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities

16,000

Advances from Federal Home Loan Banks

$ 7,000

Federal Home Loan Bank, Advances, Weighted Average Interest Rate

1.12%

Palm Beach Community Bank [Member]

Debt Instrument [Line Items]

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities

$ 284,984

Bank shares Inc [Member]

Debt Instrument [Line Items]

Secured lines of credit

$ 1,300,000

Advances from Federal Home Loan Banks

$ 207,000

Federal Home Loan Bank Borrowings [Member] | NorthStar Bank [Member]

Debt Instrument [Line Items]

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities

$ 2,000

Federal Home Loan Bank Borrowings [Member] | Palm Beach Community Bank [Member]

Debt Instrument [Line Items]

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities

$ 14,000

Debt Instrument Maturity Period One [Member]

Debt Instrument [Line Items]

Debt maturity date

Dec. 26, 2032

Long-term Debt, Gross

$ 5,200

Debt Instrument, Basis Spread on Variable Rate

4.58%

Debt Instrument, Description of Variable Rate Basis

3-month LIBOR rate plus 325 basis points

Debt Instrument Maturity Period Two [Member]

Debt Instrument [Line Items]

Debt maturity date

Mar. 17, 2034

Long-term Debt, Gross

$ 4,100

Debt Instrument, Basis Spread on Variable Rate

4.39%

Debt Instrument, Description of Variable Rate Basis

3-month LIBOR rate plus 279 basis

Debt Instrument Maturity Period Three [Member]

Debt Instrument [Line Items]

Debt maturity date

Feb. 23, 2036

Long-term Debt, Gross

$ 5,200

Debt Instrument, Interest Rate During Period

2.84%

Debt Instrument, Fair Value Disclosure

$ 3,500

Debt Instrument, Description of Variable Rate Basis

three month LIBOR rate plus 139 basis points

Debt Instrument Maturity Period Four [Member]

Debt Instrument [Line Items]

Debt maturity date

Dec. 30, 2034

Long-term Debt, Gross

$ 7,200

Debt Instrument, Interest Rate, Effective Percentage

3.67%

Debt Instrument, Fair Value Disclosure

$ 2,100

Debt Instrument, Description of Variable Rate Basis

3-month LIBOR rate plus 198 basis points

Trust I [Member]

Debt Instrument [Line Items]

Junior subordinated debentures

$ 20,000

Junior subordinated debentures private sales

20,000

Issued of common equity securities

$ 619,000

Debt Instrument, Description of Variable Rate Basis

3-month LIBOR rate plus 175 basis points

Trust II [Member]

Debt Instrument [Line Items]

Junior subordinated debentures

$ 20,000

Junior subordinated debentures private sales

$ 20,000

Issued of common equity securities

$ 619,000

Debt Instrument, Description of Variable Rate Basis

3-month LIBOR rate plus 133 basis points

Trust III [Member]

Debt Instrument [Line Items]

Issued of common equity securities

$ 372,000

Debt Instrument, Description of Variable Rate Basis

3-month LIBOR rate plus 135 basis points

Trust I & II [Member]

Debt Instrument [Line Items]

Junior subordinated debentures

$ 20,600

Aggregate subordinated debentures

$ 41,200

Junior subordinated deferrable interest notes issued

$ 41,200

Secured Lines of Credit [Member]

Debt Instrument [Line Items]

Advances from Federal Home Loan Banks

$ 211,000

Early Redemption Cost For Federal Home Loan Bank Advances

$ 1,800

Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Repayment and Penalties

$ 50,000

Federal Home Loan Bank, Advances, Activity for Year, Average Interest Rate at Period End

1.39%

Federal Home Loan Bank, Advances, Activity for Year, Average Interest Rate for Year

0.99%

Federal Home Loan Bank [Member]

Debt Instrument [Line Items]

Advances received

$ 25,000

$ 25,000

Debt maturity date

Nov. 27, 2007

Sep. 15, 2007

Fixed rates advances

2.70%

3.64%

Libor Rate [Member] | Trust I [Member]

Debt Instrument [Line Items]

Adjust basis points on variable rate, percentage

3.09%

Libor Rate [Member] | Trust II [Member]

Debt Instrument [Line Items]

Adjust basis points on variable rate, percentage

2.92%

Libor Rate [Member] | Trust III [Member]

Debt Instrument [Line Items]

Adjust basis points on variable rate, percentage

2.94%

Borrowings - Federal Funds Purc

Borrowings - Federal Funds Purchased and Securities Sold Under Agreements to Repurchase (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Short-term Debt [Line Items]
Maximum amount outstanding at any month end	$ 216,094	$ 236,099	$ 192,786
Weighted average interest rate at end of year	0.71%	0.31%	0.28%
Average amount outstanding	$ 171,686	$ 187,560	$ 168,188
Weighted average interest rate during the year	0.46%	0.26%	0.20%

Borrowings - Schedule Of Securi

Borrowings - Schedule Of Securities Financing Transactions (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Mortgage-backed securities of U.S. Government Sponsored Entities [Member]
Short-term Debt [Line Items]
Mortgage-backed securities and collateralized mortgage obligations of U.S. Government Sponsored Entities	$ 216,094	$ 204,202	$ 172,005

Employee Benefits and Stock C70

Employee Benefits and Stock Compensation - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined Contribution Plan, Cost Recognized	$ 1.9	$ 1.7	$ 1.5
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	300,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	3,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date	95.00%
2013 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 Available for Grant	591,000
Restricted Stock Units (RSUs) [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Restricted Stock Unit Percentage Of Grantee Earning	0.00%	0.00%
Restricted Stock Units (RSUs) [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Restricted Stock Unit Percentage Of Grantee Earning	200.00%	175.00%

Employee Benefits and Stock C71

Employee Benefits and Stock Compensation - Impact of shared-based compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based compensation expense	$ 5,267	$ 4,154	$ 2,859
Income tax benefit	$ (1,966)	$ (1,602)	$ (963)

Employee Benefits and Stock C72

Employee Benefits and Stock Compensation - Summary of Unrecognized Compensation Cost (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Unrecognized Compensation Cost	$ 7,160
Weighted-Average Period Remaining (Years)	1 year 9 months 18 days
Stock options [Member]
Unrecognized Compensation Cost	$ 1,374
Weighted-Average Period Remaining (Years)	2 years 4 months 24 days
Restricted Stock [Member]
Unrecognized Compensation Cost	$ 2,383
Weighted-Average Period Remaining (Years)	1 year 8 months 12 days
Restricted Stock Units (RSUs) [Member]
Unrecognized Compensation Cost	$ 3,403
Weighted-Average Period Remaining (Years)	1 year 8 months 12 days

Employee Benefits and Stock C73

Employee Benefits and Stock Compensation - Summary of Restricted Stock (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shares granted		297,576	243,391	63,650
Weighted-average grant date fair value		$ 4.66	$ 3.41	$ 2.21
Restricted Stock [Member]
Shares granted		114,331	164,599	123,806
Weighted-average grant date fair value		$ 24.08	$ 16.03	$ 15.03
Fair value of awards vested	[1]	$ 1,407	$ 1,981	$ 836
Restricted Stock Units (RSUs) [Member]
Shares granted		164,268	136,188	127,128
Weighted-average grant date fair value		$ 23.94	$ 13.53	$ 12.63
Fair value of awards vested	[1]	$ 937	$ 846	$ 0
[1]	Based on grant date fair value

Employee Benefits and Stock C74

Employee Benefits and Stock Compensation - Summary of Non-vested Restricted Stock (Details)	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Restricted Stock [Member]
Shares, Non-vested Begining | shares	206,952
Shares, Granted | shares	114,331
Shares, Forfeited/Canceled | shares	(8,733)
Shares, Vested | shares	(99,574)
Shares, Non-vested Ending | shares	212,976
Weighted Average Grant-Date Fair Value, Non-vested Begining | $ / shares	$ 14.72
Weighted Average Grant-Date Fair Value, Granted | $ / shares	24.08
Weighted Average Grant-Date Fair Value, Forfeited/Canceled | $ / shares	20.76
Weighted Average Grant-Date Fair Value, Vested | $ / shares	14.13
Weighted Average Grant-Date Fair Value, Non-vested Ending | $ / shares	$ 19.77
Restricted Stock Units (RSUs) [Member]
Shares, Non-vested Begining | shares	322,692
Shares, Granted | shares	164,268
Shares, Forfeited/Canceled | shares	(22,113)
Shares, Vested | shares	(88,880)
Shares, Non-vested Ending | shares	375,967
Weighted Average Grant-Date Fair Value, Non-vested Begining | $ / shares	$ 12.61
Weighted Average Grant-Date Fair Value, Granted | $ / shares	21.61
Weighted Average Grant-Date Fair Value, Forfeited/Canceled | $ / shares	13.79
Weighted Average Grant-Date Fair Value, Vested | $ / shares	10.54
Weighted Average Grant-Date Fair Value, Non-vested Ending | $ / shares	$ 16.96

Employee Benefits and Stock C75

Employee Benefits and Stock Compensation - Summary of the Fair Value of Each Option Grant on the Date of Grant (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Risk-free interest rates	1.85%	1.63%	1.65%
Expected dividend yield	0.00%	0.00%	0.00%
Expected volatility	25.40%	21.90%	15.50%
Expected lives (years)	5 years	5 years	5 years

Employee Benefits and Stock C76

Employee Benefits and Stock Compensation - Summary of Stock Options Outstanding and Exercisable (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shares granted	297,576	243,391	63,650
Equity Option [Member]
Options, Outstanding at January 1, 2017	778,778
Shares granted	297,576
Options, Exercised	(91,468)
Options, Forfeited	(33,537)
Options, Outstanding at December 31, 2017	951,349	778,778
Options, Exercisable at December 31, 2017	517,100
Weighted-Average Exercise Price, Outstanding at January 1, 2017	$ 15.86
Weighted-Average Exercise Price, Granted	28.21
Weighted-Average Exercise Price, Exercised	11.77
Weighted-Average Exercise Price, Forfeited	96.17
Weighted-Average Exercise Price, Outstanding at December 31, 2017	17.29	$ 15.86
Weighted-Average Exercise Price, Exercisable at December 31, 2017	$ 12.09
Weighted-Average Remaining Contractual Term, Outstanding	6 years 10 months 10 days
Weighted-Average Remaining Contractual Term, Exercisable at December 31, 2017	5 years 10 months 6 days
Aggregate Intrinsic Value, Outstanding at December 31, 2017	$ 8,493
Aggregate Intrinsic Value, Exercisable at December 31, 2017	$ 6,787

Employee Benefits and Stock C77

Employee Benefits and Stock Compensation - Summary of information related to stock options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Options granted	297,576	243,391	63,650
Weighted-average grant date fair value	$ 4.66	$ 3.41	$ 2.21
Intrinsic value of stock options exercised	$ 1,143	$ 80	$ 0

Employee Benefits and Stock C78

Employee Benefits and Stock Compensation - Summary of Information Related to Options (Details)	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Options Outstanding | shares	951,349
Remaining contractual Life (Years)	6 years 10 months 24 days
Shares Exercisable | shares	517,100
Weighted Average Exercise Price	$ 12.09
Range of Exercise Prices 10.54 to 10.78 [Member]
Options Outstanding | shares	330,000
Remaining contractual Life (Years)	5 years 9 months 18 days
Shares Exercisable | shares	330,000
Weighted Average Exercise Price	$ 10.67
Range of Exercise Prices, Lower Range Limit	10.54
Range of Exercise Prices, Upper Range Limit	$ 10.78
Range of Exercise Prices 10.97 to 15.99 [Member]
Options Outstanding | shares	323,773
Remaining contractual Life (Years)	5 years 9 months 18 days
Shares Exercisable | shares	163,538
Weighted Average Exercise Price	$ 13.42
Range of Exercise Prices, Lower Range Limit	10.97
Range of Exercise Prices, Upper Range Limit	$ 15.99
Range of Exercise Prices 22.65 to 28.69 [Member]
Options Outstanding | shares	297,576
Remaining contractual Life (Years)	9 years 2 months 12 days
Shares Exercisable | shares	23,562
Weighted Average Exercise Price	$ 22.65
Range of Exercise Prices, Lower Range Limit	22.65
Range of Exercise Prices, Upper Range Limit	$ 28.69

Employee Benefits and Stock C79

Employee Benefits and Stock Compensation - Employee Stock Purchase Plan (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
ESPP shares purchased	297,576	243,391	63,650
Employee Stock Option [Member]
ESPP shares purchased	12,434	10,483	9,083
Weighted-average employee purchase price	$ 22.67	$ 16.02	$ 13.99

Lease Commitments - Additional

Lease Commitments - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Rent expense charged to operations	$ 5.8	$ 5.3	$ 4.1

Lease Commitments - Future Mini

Lease Commitments - Future Minimum Lease Payments Under Leases (Details) $ in Thousands	Dec. 31, 2017USD ($)
2,018	$ 6,303
2,019	5,935
2,020	5,324
2,021	4,003
2,022	3,275
Thereafter	15,885
Total	$ 40,725

Income Taxes - Summary of Incom

Income Taxes - Summary of Income Tax Expense Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current
Federal	$ 667	$ 653	$ 578
State	2	30	61
Deferred
Federal	32,791	12,163	10,818
State	2,876	2,043	2,070
Total income tax provision	$ 36,336	$ 14,889	$ 13,527

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Expected Tax Benefit with Income Tax Benefit Relating to Loss before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Tax rate applied to income before income taxes	$ 27,720	$ 15,431	$ 12,484
Increase (decrease) resulting from the effects of:
Tax law change	8,552	0	0
Nondeductible acquisition costs	657	217	441
Tax exempt interest on obligations of states and political subdivisions and bank owned life insurance	(1,445)	(1,215)	(761)
State income taxes	(1,007)	(726)	(746)
Nontaxable bargain purchase gain	0	0	(146)
Tax credit investments	(165)	(55)	0
Stock compensation	(1,027)	(731)	127
Other	173	(105)	(3)
Federal tax provision	33,458	12,816	11,396
State tax provision	2,878	2,073	2,131
Total income tax provision	$ 36,336	$ 14,889	$ 13,527

Income Taxes - Summary of Net D

Income Taxes - Summary of Net Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 22, 2017	Dec. 31, 2016
Allowance for loan losses	$ 7,187		$ 9,477
Premises and equipment	1,390		2,334
Other real estate owned	207		841
Accrued stock compensation	1,569		1,561
Federal tax loss carryforward	4,755		28,089
State tax loss carryforward	5,578		6,123
Alternative minimum tax credit carryforward	2,209		4,261
Net unrealized securities losses	1,429		4,616
Deferred compensation	2,125		3,279
Accrued interest and fee income	2,411		3,267
Other	2,248		3,748
Gross deferred tax assets	31,108		67,596
Less: Valuation allowance	0		0
Deferred tax assets net of valuation allowance	31,108		67,596
Core deposit base intangible	(3,964)		(3,953)
Other	(1,727)		(2,825)
Gross deferred tax liabilities	(5,691)		(6,778)
Net deferred tax assets	$ 25,417	$ 34,000	$ 60,818

Income Taxes - Summary of balan

Income Taxes - Summary of balances before and after the adjustment between AOCI and retained earnings (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Preconfirmation, Retained Earnings (Deficit)	$ 29,208
Accumulated Other Comprehensive Income Loss, Before adjustment	(3,510)
Retained Earnings (Accumulated Deficit)	29,914	$ (13,657)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(4,216)	$ (7,513)
Retained Earnings [Member]
Adjustment for ASU 2018-02	706
Accumulated Other Comprehensive Income (Loss) [Member]
Adjustment for ASU 2018-02	$ (706)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 22, 2017	Dec. 01, 2017
Operating Loss Carryforwards [Line Items]
Net deferred tax assets		$ 25,417,000	$ 60,818,000		$ 34,000,000
Deferred Tax Assets Related to State Net Operating Losses		5,600,000
Deferred Tax Assets, Operating Loss Carryforwards, Domestic		4,755,000	28,089,000
Deferred Tax Assets, Unrealized Losses on Available-for-Sale Securities, Gross		1,429,000	4,616,000
Amortization Method Qualified Affordable Housing Project Investments, Amortization		713,000	39,000
Affordable Housing Program Obligation Unfunded		$ 10,000,000	$ 8,300,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%	35.00%	35.00%
Deferred Income Tax Assets, Net					8,600,000	$ 25,400,000
Deferred Tax Assets, Net		$ 25,417,000	$ 60,818,000		$ 34,000,000
Scenario, Plan [Member]
Operating Loss Carryforwards [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Minimum [Member]
Operating Loss Carryforwards [Line Items]
Annual income before taxes		2,200,000
U.S. Federal [Member]
Operating Loss Carryforwards [Line Items]
Net deferred tax assets		15,400,000
Deferred Tax Assets, Net		$ 15,400,000
U.S. Federal [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carry forwards Expiration Period		2,032
U.S. Federal [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carry forwards Expiration Period		2,029
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net deferred tax assets		$ 10,000,000
Deferred Tax Assets, Net		$ 10,000,000
State and Local Jurisdiction [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carry forwards Expiration Period		2,034
State and Local Jurisdiction [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carry forwards Expiration Period		2,029

Noninterest Income and Expens87

Noninterest Income and Expenses - Summary of Noninterest Income and Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Noninterest income
Service charges on deposit accounts	$ 10,049	$ 9,669	$ 8,563
Trust fees	3,705	3,433	3,132
Mortgage banking fees	6,449	5,864	4,252
Brokerage commissions and fees	1,352	2,044	2,132
Marine finance fees	910	673	1,152
Interchange income	10,583	9,227	7,684
Other deposit based EFT fees	465	477	397
BOLI income	3,426	2,213	1,426
Gain on participated income	0	0	725
Other	6,291	3,827	2,555
Noninterest Income	43,230	37,427	32,018
Securities gains, net	86	368	161
Gain on sale of VISA stock	15,153	0	0
Bargain purchase gain, net	0	0	416
TOTAL	58,469	37,795	32,595
Noninterest expense
Salaries and wages	65,692	54,096	41,075
Employee benefits	11,732	9,903	9,564
Outsourced data processing costs	14,116	13,516	10,150
Telephone/data lines	2,291	2,108	1,797
Occupancy	13,290	13,122	8,744
Furniture and equipment	6,067	4,720	3,434
Marketing	4,784	3,633	4,428
Legal and professional fees	11,022	9,596	8,022
FDIC assessments	2,326	2,365	2,212
Amortization of intangibles	3,361	2,486	1,424
Asset dispositions expense	411	553	472
Net (gain)/loss on other real estate owned and repossessed assets	(711)	(509)	239
Early redemption cost for Federal Home Loan Bank advances	0	1,777	0
Other	15,535	13,515	12,209
TOTAL	$ 149,916	$ 130,881	$ 103,770

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Details) - USD ($) $ in Thousands	Feb. 21, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common stock net issuance costs	$ 56,700	$ 55,641	$ 0	$ 0
Stock Issued During Period, Shares, New Issues	8,900,000
Capital Conservation Buffer Rate		1.25%
Parent [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Stock Issued During Period, Shares, New Issues	2,700,000
Shareholders [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Stock Issued During Period, Shares, New Issues	6,200,000
Stock Purchase Plan [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Reserved common shares for issuance		300,000
Common shares issued as a result of employee participation, aggregate		175,997
Profit Sharing Plan [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Reserved common shares for issuance		1,000,000
Common shares issued as a result of employee participation, aggregate		32,120

Shareholders' Equity - Summary

Shareholders' Equity - Summary of Required Regulatory Capital (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Parent Company [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital (to risk-weighted assets), Amount		$ 619,746	$ 432,058
Total Capital (to risk-weighted assets), Ratio		14.24%	13.25%
Total Capital (to risk-weighted assets), Minimum for Capital Adequacy Purpose, Amount	[1]	$ 348,191	$ 260,790
Total Capital (to risk-weighted assets), Minimum for Capital Adequacy Purpose, Ratio	[1]	8.00%	8.00%
Tier 1 Capital (to risk-weighted assets), Amount		$ 592,562	$ 408,596
Tier 1 Capital (to risk-weighted assets), Ratio		13.61%	12.53%
Tier 1 Capital (to risk-weighted assets), Minimum for Capital Adequacy Purpose, Amount	[1]	$ 261,143	$ 195,592
Tier 1 Capital (to risk-weighted assets), Minimum for Capital Adequacy Purpose, Ratio	[1]	6.00%	6.00%
Common Equity Tier 1 Capital (to risk-weighted assets), Amount		$ 523,832	$ 351,769
Common Equity Tier 1 Capital (to risk-weighted assets), Ratio		12.04%	10.79%
Common Equity Tier 1 Capital (to risk-weighted assets), Minimum for Capital, Adequacy Purpose, Amount	[1]	$ 195,858	$ 146,694
Common Equity Tier 1 Capital (to risk-weighted assets), Minimum for Capital, Adequacy Purpose, Ratio	[1]	4.50%	4.50%
Trust preferred securities issued		$ 592,562	$ 408,596
Tier 1 Capital (to adjusted average assets), Ratio		10.68%	9.15%
Tier 1 Capital (to adjusted average assets), Minimum for Capital Adequacy Purpose, Amount	[1]	$ 221,863	$ 178,656
Tier 1 Capital (to adjusted average assets), Minimum for Capital Adequacy Purpose, Ratio	[1]	4.00%	4.00%
Seacoast National Bank (A Wholly Owned Bank Subsidiary) [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital (to risk-weighted assets), Amount		$ 565,149	$ 415,147
Total Capital (to risk-weighted assets), Ratio		13.04%	12.75%
Total Capital (to risk-weighted assets), Minimum for Capital Adequacy Purpose, Amount	[1]	$ 346,780	$ 260,491
Total Capital (to risk-weighted assets), Minimum for Capital Adequacy Purpose, Ratio	[1]	8.00%	8.00%
Tier 1 Capital (to risk-weighted assets), Amount		$ 537,965	$ 391,685
Tier 1 Capital (to risk-weighted assets), Ratio		12.41%	12.03%
Tier 1 Capital (to risk-weighted assets), Minimum for Capital Adequacy Purpose, Amount	[1]	$ 260,085	$ 195,368
Tier 1 Capital (to risk-weighted assets), Minimum for Capital Adequacy Purpose, Ratio	[1]	6.00%	6.00%
Common Equity Tier 1 Capital (to risk-weighted assets), Amount		$ 537,965	$ 391,685
Common Equity Tier 1 Capital (to risk-weighted assets), Ratio		12.41%	12.03%
Common Equity Tier 1 Capital (to risk-weighted assets), Minimum for Capital, Adequacy Purpose, Amount	[1]	$ 195,022	$ 146,526
Common Equity Tier 1 Capital (to risk-weighted assets), Minimum for Capital, Adequacy Purpose, Ratio	[1]	4.50%	4.50%
Trust preferred securities issued		$ 537,965	$ 391,685
Tier 1 Capital (to adjusted average assets), Ratio		9.72%	8.78%
Tier 1 Capital (to adjusted average assets), Minimum for Capital Adequacy Purpose, Amount	[1]	$ 221,432	$ 178,501
Tier 1 Capital (to adjusted average assets), Minimum for Capital Adequacy Purpose, Ratio	[1]	4.00%	4.00%
Total Capital (to risk-weighted assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		$ 433,475	$ 325,987
Total Capital (to risk-weighted assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	[1]	10.00%	10.00%
Tier 1 Capital (to risk-weighted assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		$ 346,780	$ 260,790
Tier 1 Capital (to risk-weighted assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	[1]	8.00%	8.00%
Tier 1 Capital (to adjusted average assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		$ 276,791	$ 223,320
Tier 1 Capital (to adjusted average assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	[1]	5.00%	5.00%
Common Equity Tier 1 Capital (to risk-weighted assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		$ 281,759	$ 211,892
Common Equity Tier 1 Capital (to risk-weighted assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	[1]	6.50%	6.50%
[1]	Excludes capital conservation buffer of 1.250% the Company is subject to, which if not exceeded may constrain dividends, equity repurchases and compensation.

(Parent Company Only) Financi90

(Parent Company Only) Financial Information - Summary of Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Other assets	$ 110,246	$ 83,567
TOTAL ASSETS	5,810,129	4,680,932
LIABILITIES AND SHAREHOLDERS' EQUITY
Subordinated debt	70,521	70,241
Other liabilities	30,130	32,847
Shareholders' equity	689,664	435,397	$ 353,453	$ 312,651
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	5,810,129	4,680,932
Parent Company [Member]
ASSETS
Cash	1,154	648
Securities purchased under agreement to resell with subsidiary bank, maturing within 30 days	33,151	12,676
Investment in subsidiaries	711,973	494,809
Other assets	21,337	1,211
TOTAL ASSETS	767,615	509,344
LIABILITIES AND SHAREHOLDERS' EQUITY
Subordinated debt	70,521	70,241
Other liabilities	7,430	3,706
Shareholders' equity	689,664	435,397
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 767,615	$ 509,344

(Parent Company Only) Financi91

(Parent Company Only) Financial Information - Summary of Statements of Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income
Gain on sale of VISA stock	$ 15,153	$ 0	$ 0
Total interest income	191,596	148,055	116,417
Interest expense	15,300	8,467	6,930
Other expenses	15,535	13,515	12,209
Income tax provision (benefit) benefit	36,336	14,889	13,527
Net income	42,865	29,202	22,141
Parent Company [Member]
Income
Interest/other	2,104	352	115
Dividends from subsidiary Bank	0	0	0
Gain on sale of VISA stock	15,153	0	0
Total interest income	17,257	352	115
Interest expense	2,499	2,115	1,671
Other expenses	649	462	317
Income (loss) before income taxes and equity in undistributed income of subsidiaries	14,109	(2,225)	(1,873)
Income tax provision (benefit) benefit	4,938	(801)	(661)
Income (loss) before equity in undistributed income of subsidiaries	9,171	(1,424)	(1,212)
Equity in undistributed income of subsidiaries	33,694	30,626	23,353
Net income	$ 42,865	$ 29,202	$ 22,141

(Parent Company Only) Financi92

(Parent Company Only) Financial Information - Summary of Statement of Cash Flows (Details) - USD ($) $ in Thousands	Feb. 21, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Adjustments to reconcile net income to net cash provided by operating activities:
Net Income		$ 42,865	$ 29,202	$ 22,141
Gain on sale of VISA stock		(15,153)	0	0
Net (increase) decrease in other assets		5,506	11,573	4,828
Increase (Decrease) in Other Operating Liabilities		(21,432)	2,979	(628)
Net cash used in operating activities		48,909	62,007	29,509
Cash flows from investing activities
Investment in VISA stock		(6,180)	0	0
Net cash provided by (used in) investment activities		(245,576)	(511,785)	(170,901)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of common stock, net of related expense	$ 56,700	55,641	0	0
Net cash provided by financing activities		196,527	423,355	176,920
Net change in cash		(140)	(26,423)	35,528
Cash and cash equivalents at beginning of year		109,644	136,067	100,539
Cash and cash equivalents at end of year		109,504	109,644	136,067
Supplemental disclosure of cash flow information:
Cash paid during the period for interest		15,125	7,855	6,636
Parent Company [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Net Income		42,865	29,202	22,141
Equity in undistributed income of subsidiaries		(33,694)	(30,626)	(23,353)
Gain on sale of VISA stock		(15,153)	0	0
Net (increase) decrease in other assets		1,415	(12)	10
Increase (Decrease) in Other Operating Liabilities		4,005	12	(48)
Net cash used in operating activities		(562)	(1,424)	(1,250)
Cash flows from investing activities
Net cash paid for bank acquisition		(27,862)	(28,905)	0
Investment in unconsolidated subsidiary		0	(200)	0
Investment in VISA stock		(6,180)	0	0
Decrease (increase) in securities purchased under agreement to resell, maturing within 30 days, net		(20,475)	30,647	(5,487)
Net cash provided by (used in) investment activities		(54,517)	1,542	(5,487)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of common stock, net of related expense		55,641	0	0
Subordinated debt increase		0	0	6,494
Stock based employment plans		(56)	166	127
Net cash provided by financing activities		55,585	166	6,621
Net change in cash		506	284	(116)
Cash and cash equivalents at beginning of year		648	364	480
Cash and cash equivalents at end of year		1,154	648	364
Supplemental disclosure of cash flow information:
Cash paid during the period for interest		$ 2,205	$ 1,824	$ 1,487

Contingent Liabilities and Co93

Contingent Liabilities and Commitments with Off-Balance Sheet Risk - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitment to extend credit amount	$ 807,651	$ 532,082
Unfunded limited partner equity commitment	$ 10,914	10,148
Maximum [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitment to extend credit fixed interest rate	5.50%
Minimum [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitment to extend credit fixed interest rate	3.00%
Secured Credit Risk [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Secured amount of commitment to extend credit	$ 368,700
Secured [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	26,400	$ 46,600
Fixed Interest Rate Credit Risk [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit fixed interest rate	$ 86,500

Contingent Liabilities and Co94

Contingent Liabilities and Commitments with Off-Balance Sheet Risk - Summary of Financial Instruments with Off-Balance-Sheet Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Commitments to extend credit	$ 807,651	$ 532,082
Unfunded limited partner equity commitment	10,914	10,148
Secured
Standby letters of credit and financial guarantees written	12,913	10,776
Unsecured
Standby letters of credit and financial guarantees written	$ 681	$ 554

FAIR VALUE - Additional Informa

FAIR VALUE - Additional Information (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization Rates Utilized To Determine Fair Value Of Underlying Collateral Averaged Percentage	[1]	7.80%
Loans and Leases Receivable, Allowance		$ 27,122	$ 23,400	$ 19,128	$ 17,007
Loans Receivable [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		400
Other Real Estate Owned And Other Reductions		600
Other Real Estate Owned And Principal Reductions		500
Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		1,700
Other Real Estate Revenue		5,000
Other real estate owned and other reductions classified as level three transfers in		1,200
Loans Receivable, Fair Value Disclosure		4,200	4,100
Loans and Leases Receivable, Allowance		2,400	$ 400
Other Real Estate, Disposals		$ 5,300
[1]	See Note D for further detail of recurring fair value basis of individual investment categories.

FAIR VALUE - Fair Value Measure

FAIR VALUE - Fair Value Measurements for Items Measured at Fair Value (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	[1]		$ 100
Loans held for sale		$ 24,306	15,332
Other real estate owned		7,640	9,949
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	[1]	955,804	950,503
Loans held for sale	[2]	24,306	15,332
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	[1]	6,600
Loans held for sale	[2]	0	0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	[1]	949,204	950,403
Loans held for sale	[2]	24,306	15,332
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	[1]	0	0
Loans held for sale	[2]	0	0
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	[3]	4,192	4,120
Other real estate owned	[4]	7,640	9,949
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	[3]	0	0
Other real estate owned	[4]	0	0
Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	[3]	3,454	3,170
Other real estate owned	[4]	60	0
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	[3]	738	950
Other real estate owned	[4]	$ 7,580	$ 9,949
[1]	See Note D for further detail of fair value of individual investment categories.
[2]	Recurring fair value basis determined using observable market data.
[3]	See Note E. Nonrecurring fair value adjustments to loans identified as impaired reflect full or partial write- downs that are based on the loan’s observable market price or current appraised value of the collateral in accordance with ASC 310.
[4]	Fair value is measured on a nonrecurring basis in accordance with ASC 360.

FAIR VALUE - Summary of Carryin

FAIR VALUE - Summary of Carrying Value and Fair Value of Company's Financial Instruments (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity		$ 416,863	$ 372,498
Loans, net		3,790,255	2,856,136
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	[1]	0	0
Time deposits with other banks		0
Loans, net		0	0
Deposit		0	0
Subordinated debt		0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	[1]	414,472	369,881
Time deposits with other banks		0
Loans, net		0	0
Deposit		0	0
Subordinated debt		61,530	54,908
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	[1]	0	0
Time deposits with other banks		12,493
Loans, net		3,760,754	2,840,993
Deposit		4,588,515	3,523,322
Subordinated debt		0	0
Carrying Amount [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	[1]	416,863	372,498
Time deposits with other banks		12,553
Loans, net		3,786,063	2,852,016
Deposit		4,592,720	3,523,245
Subordinated debt		$ 70,521	$ 70,241
[1]	See Note D for further detail of recurring fair value basis of individual investment categories.

FAIR VALUE - fair value of cont

FAIR VALUE - fair value of contractual balance and gains or losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Aggregate fair value	$ 24,306	$ 15,332
Contractual balance	23,627	14,904
Excess	$ 679	$ 428

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shares excluded from computation of diluted EPS	274,000	131,000	456,000

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic earnings per share
Net Income	$ 42,865	$ 29,202	$ 22,141
Total weighted average common stock outstanding	42,613,086	36,872,007	33,495,827
Net income per share	$ 1.01	$ 0.79	$ 0.66
Diluted earnings per share
Net income	$ 42,865	$ 29,202	$ 22,141
Total weighted average common stock outstanding	42,613,086	36,872,007	33,495,827
Add: Dilutive effect of employee restricted stock and stock options (See Note J)	737,000	636,000	248,000
Total weighted average diluted stock outstanding	43,350,314	37,508,046	33,744,171
Net income per share	$ 0.99	$ 0.78	$ 0.66

BUSINESS COMBINATIONS - Additio

BUSINESS COMBINATIONS - Additional Information (Details) - USD ($) $ in Thousands	Nov. 03, 2017	Oct. 20, 2017	Apr. 07, 2017	Mar. 11, 2016	Dec. 31, 2017	Dec. 31, 2016	Jun. 03, 2016
Business Acquisition [Line Items]
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Deposit Premium Percentage							3.00%
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Loan Held For Sale							$ 314,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable							63,000
Business Acquisition Intangible Assets Expected Tax Deductible Amount							$ 13,000
Business Loan Premium							0.50%
Business Combination, Acquisition Related Costs					$ 12,900	$ 9,000
Floridian Financial Group [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets				$ 417,000
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Liabilities Deposits				337,000
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Noncurrent Assets Loans				266,000
Business Acquisition, Equity Interest Issued or Issuable, Description					Under the terms of the definitive agreement, Floridian shareholders received, at their election, (i) the combination of $4.29 in cash and 0.5291 shares of Seacoast common stock, (ii) $12.25 in cash, or (iii) 0.8140 shares of Seacoast common stock, subject to a customary proration mechanism so that the aggregate consideration mix equals 35% cash and 65% Seacoast shares (based on Seacoast’s closing price of $15.47 per share on March 11, 2016).
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount				$ 32,000
BMO Harris Central [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets							$ 314,000
Gulf Shore Banc shares Inc [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets			$ 358,000
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Liabilities Deposits			285,000
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Noncurrent Assets Loans			251,000
Business Acquisition, Equity Interest Issued or Issuable, Description					Under the terms of the definitive agreement, GulfShore shareholders received, for each share of GulfShore common stock, the combination of $1.47 in cash and 0.4807 shares of Seacoast common stock (based on Seacoast’s closing price of $23.94 per share on April 7, 2017).
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount			$ 37,100
Gulf Shore Banc shares Inc [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired					100.00%
Palm Beach Community Bank [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	$ 9,909
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Liabilities Deposits	269,000
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Noncurrent Assets Loans	$ 272,000
Business Acquisition, Equity Interest Issued or Issuable, Description	Under the terms of the definitive agreement, PBCB shareholders received, for each share of PBCB common stock, the combination of $6.26 in cash and 0.9240 shares of Seacoast common stock (based on Seacoasts closing price of $24.31 per share on November 3, 2017).
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Loan Held For Sale	$ 272,090
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable	268,633
Business Acquisition Intangible Assets Tax Deductible Period					15 years
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount	$ 33,400
NorthStar Bank [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets		$ 216,000
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Liabilities Deposits		182,000
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Noncurrent Assets Loans		$ 137,000
Business Acquisition, Equity Interest Issued or Issuable, Description		Under the terms of the definitive agreement, NSBC shareholders received, for each share of NSBC common stock, the combination of $2.40 in cash and 0.5605 shares of Seacoast common stock (based on Seacoasts closing price of $24.92 per share on October 20, 2017)
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount		$ 12,400

BUSINESS COMBINATIONS - Purchas

BUSINESS COMBINATIONS - Purchase Price (Details) $ / shares in Units, $ in Thousands	Nov. 03, 2017USD ($)$ / sharesshares	Oct. 20, 2017USD ($)$ / sharesshares	Apr. 07, 2017USD ($)$ / sharesshares	Mar. 11, 2016USD ($)$ / sharesshares
Floridian Financial Group [Member]
Business Acquisition [Line Items]
Shares exchanged for cash				$ 26,699
Number of Palm Beach Community Bank Common shares outstanding | shares				6,222
Per share exchange ratio				0.5289
Number of shares of common stock issued | shares				3,291
Multiplied by common stock price per share | $ / shares				$ 15.47
Value of common stock issued				$ 50,913
Total purchase price				$ 77,612
Bank shares, Inc [Member]
Business Acquisition [Line Items]
Shares exchanged for cash	$ 15,694
Number of Palm Beach Community Bank Common shares outstanding | shares	2,507
Per share exchange ratio	0.9240
Number of shares of common stock issued | shares	2,316
Multiplied by common stock price per share | $ / shares	$ 24.31
Value of common stock issued	$ 56,312
Total purchase price	$ 72,006
Gulf Shore Banc shares Inc [Member]
Business Acquisition [Line Items]
Shares exchanged for cash			$ 8,034
Number of Palm Beach Community Bank Common shares outstanding | shares			5,464
Per share exchange ratio			0.4807
Number of shares of common stock issued | shares			2,627
Multiplied by common stock price per share | $ / shares			$ 23.94
Value of common stock issued			$ 62,883
Total purchase price			$ 70,917
NorthStar Bank [Member]
Business Acquisition [Line Items]
Shares exchanged for cash		$ 4,701
Number of Palm Beach Community Bank Common shares outstanding | shares		1,958
Per share exchange ratio		0.5605
Number of shares of common stock issued | shares		1,098
Multiplied by common stock price per share | $ / shares		$ 24.92
Value of common stock issued		$ 27,353
Cash paid for NorthStar Banking vested Corporation stock options		801
Total purchase price		$ 32,855

BUSINESS COMBINATIONS - fair va

BUSINESS COMBINATIONS - fair value of the assets purchased, including goodwill, and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Nov. 03, 2017	Oct. 20, 2017	Apr. 07, 2017	Dec. 31, 2016	Jun. 03, 2016	Mar. 11, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets:
Loans, net						$ 314,000
Goodwill	$ 147,578				$ 64,649			$ 25,211	$ 25,309
Liabilities:
Deposits						63,000
Total liabilities assumed	$ 16,000
Floridian Financial Group [Member]
Assets:
Other assets							$ 417,000
Floridian Financial Group [Member] | Measurement Period Adjustments [Member]
Assets:
Cash							0
Investment securities							95
Loans, net							(2,112)
Fixed assets							(628)
Core deposit intangibles							0
Goodwill							1,647
Other assets							998
Total assets acquired							0
Liabilities:
Deposits							0
Other liabilities							0
Total liabilities assumed							0
Floridian Financial Group [Member] | Scenario, Previously Reported [Member]
Assets:
Cash							28,243
Investment securities							66,912
Loans, net							268,249
Fixed assets							7,801
Core deposit intangibles							3,375
Goodwill							29,985
Other assets							12,879
Total assets acquired							417,444
Liabilities:
Deposits							337,341
Other liabilities							2,492
Total liabilities assumed							339,833
Floridian Financial Group [Member] | Restatement Adjustment [Member]
Assets:
Cash							28,243
Investment securities							67,007
Loans, net							266,137
Fixed assets							7,173
Core deposit intangibles							3,375
Goodwill							31,632
Other assets							13,877
Total assets acquired							417,444
Liabilities:
Deposits							337,341
Other liabilities							2,492
Total liabilities assumed							$ 339,833
BMO Harris Bank [Member] | Measurement Period Adjustments [Member]
Assets:
Cash						0
Loans, net						0
Fixed assets						0
Core deposit intangibles						(135)
Goodwill						163
Other assets						(28)
Total assets acquired						0
Liabilities:
Deposits						0
Other liabilities						0
Total liabilities assumed						0
BMO Harris Bank [Member] | Scenario, Previously Reported [Member]
Assets:
Cash						234,094
Loans, net						62,671
Fixed assets						3,715
Core deposit intangibles						5,223
Goodwill						7,645
Other assets						952
Total assets acquired						314,300
Liabilities:
Deposits						314,248
Other liabilities						52
Total liabilities assumed						314,300
BMO Harris Bank [Member] | Restatement Adjustment [Member]
Assets:
Cash						234,094
Loans, net						62,671
Fixed assets						3,715
Core deposit intangibles						5,088
Goodwill						7,808
Other assets						924
Total assets acquired						314,300
Liabilities:
Deposits						314,248
Other liabilities						52
Total liabilities assumed						$ 314,300
Gulf Shore Banc shares Inc [Member]
Assets:
Other assets				$ 358,000
Gulf Shore Banc shares Inc [Member] | Measurement Period Adjustments [Member]
Assets:
Cash				0
Time deposits with other banks				0
Investment securities				0
Loans, net				0
Fixed assets				0
Other real estate owned (OREO)				0
Core deposit intangibles				0
Goodwill				0
Other assets				0
Total assets acquired				0
Liabilities:
Deposits				0
Other liabilities				0
Total liabilities assumed				0
Gulf Shore Banc shares Inc [Member] | Scenario, Previously Reported [Member]
Assets:
Cash				38,267
Time deposits with other banks				17,273
Investment securities				21
Loans, net				250,876
Fixed assets				1,307
Other real estate owned (OREO)				13
Core deposit intangibles				3,927
Goodwill				37,098
Other assets				8,867
Total assets acquired				357,649
Liabilities:
Deposits				285,350
Other liabilities				1,382
Total liabilities assumed				286,732
Gulf Shore Banc shares Inc [Member] | Restatement Adjustment [Member]
Assets:
Cash				38,267
Time deposits with other banks				17,273
Investment securities				21
Loans, net				250,876
Fixed assets				1,307
Other real estate owned (OREO)				13
Core deposit intangibles				3,927
Goodwill				37,098
Other assets				8,867
Total assets acquired				357,649
Liabilities:
Deposits				285,350
Other liabilities				1,382
Total liabilities assumed				$ 286,732
NorthStar Bank [Member]
Assets:
Other assets			$ 216,000
NorthStar Bank [Member] | Scenario, Previously Reported [Member]
Assets:
Cash			5,485
Investment securities			56,123
Loans, net			136,832
Fixed assets			2,637
Core deposit intangibles			1,275
Goodwill			12,404
Other assets			1,522
Total assets acquired			216,278
Liabilities:
Deposits			182,443
Other liabilities			980
Total liabilities assumed			$ 183,423
Palm Beach Community Bank [Member]
Assets:
Cash		$ 9,301
Investment securities		22,098
Loans, net		272,090
Fixed assets		7,641
Core deposit intangibles		2,523
Goodwill		33,428
Other assets		9,909
Total assets acquired		356,990
Liabilities:
Deposits		268,633
Other liabilities		16,351
Total liabilities assumed		$ 284,984

BUSINESS COMBINATIONS - fair104

BUSINESS COMBINATIONS - fair value of acquired loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Nov. 03, 2017	Oct. 20, 2017	Apr. 07, 2017	Dec. 31, 2016	Jun. 03, 2016	Mar. 11, 2016	Dec. 31, 2015	Dec. 31, 2014
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	$ 3,699				$ 3,807			$ 2,610	$ 1,192
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value				$ 250,876
Commercial Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net				106,729
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value				103,905
Commercial Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net				32,137
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value				32,247
Single Family Residential Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net				101,281
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value				99,598
Construction Development Land [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net				13,175
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value				11,653
Consumer And Other Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net				3,554
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value				3,473
Floridian Financial Group [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net							$ 280,022
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value							266,137
Floridian Financial Group [Member] | Commercial Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net							172,531
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value							167,105
Floridian Financial Group [Member] | Commercial Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net							39,070
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value							37,804
Floridian Financial Group [Member] | Single Family Residential Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net							38,304
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value							37,367
Floridian Financial Group [Member] | Construction Development Land [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net							20,546
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value							18,108
Floridian Financial Group [Member] | Consumer And Other Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net							3,385
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value							3,110
Floridian Financial Group [Member] | Purchased Credit Impaired [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net							6,186
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value							$ 2,643
BMO Harris Bank [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net						$ 64,043
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value						62,671
BMO Harris Bank [Member] | Commercial Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net						31,564
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value						31,200
BMO Harris Bank [Member] | Commercial Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net						32,479
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value						31,471
BMO Harris Bank [Member] | Purchased Credit Impaired [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net						0
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value						$ 0
NorthStar Bank [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net			$ 143,444
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value			136,832
NorthStar Bank [Member] | Commercial Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net			73,139
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value			69,554
NorthStar Bank [Member] | Commercial Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net			31,200
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value			30,854
NorthStar Bank [Member] | Single Family Residential Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net			15,111
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value			15,096
NorthStar Bank [Member] | Construction Development Land [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net			11,706
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value			10,390
NorthStar Bank [Member] | Consumer And Other Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net			6,761
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value			6,645
NorthStar Bank [Member] | Purchased Credit Impaired [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net			5,527
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value			$ 4,293
Palm Beach Community Bank [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net		$ 275,567
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value		272,090
Palm Beach Community Bank [Member] | Commercial Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net		134,705
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value		132,654
Palm Beach Community Bank [Member] | Commercial Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net		36,076
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value		37,083
Palm Beach Community Bank [Member] | Single Family Residential Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net		30,153
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value		30,990
Palm Beach Community Bank [Member] | Construction Development Land [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net		69,686
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value		67,425
Palm Beach Community Bank [Member] | Consumer And Other Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net		179
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value		172
Palm Beach Community Bank [Member] | Purchased Credit Impaired [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net		4,768
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value		$ 3,766
Bank shares Inc [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net				0
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value				$ 0

BUSINESS COMBINATIONS - purc105

BUSINESS COMBINATIONS - purchased credit impaired loans (Details) - USD ($) $ in Thousands	Nov. 03, 2017	Oct. 20, 2017	Apr. 07, 2017	Mar. 11, 2016
Total purchased credit-impaired loan acquired			$ 250,876
Floridian Financial Group [Member]
Total purchased credit-impaired loan acquired				$ 266,137
Floridian Financial Group [Member] | Purchased Credit Impaired [Member]
Contractually required principal and interest				8,031
Non-accretable difference				(4,820)
Cash flows expected to be collected				3,211
Accretable yield				(568)
Total purchased credit-impaired loan acquired				$ 2,643
Palm Beach Community Bank [Member]
Total purchased credit-impaired loan acquired	$ 272,090
Palm Beach Community Bank [Member] | Purchased Credit Impaired [Member]
Total purchased credit-impaired loan acquired	3,766
Palm Beach Community Bank [Member] | Purchased Impaired Loans [Member]
Contractually required principal and interest	4,768
Non-accretable difference	(1,002)
Cash flows expected to be collected	3,766
Accretable yield	0
Total purchased credit-impaired loan acquired	$ 3,766
NorthStar Bank [Member]
Total purchased credit-impaired loan acquired		$ 136,832
NorthStar Bank [Member] | Purchased Credit Impaired [Member]
Total purchased credit-impaired loan acquired		4,293
NorthStar Bank [Member] | Purchased Impaired Loans [Member]
Contractually required principal and interest		5,596
Non-accretable difference		(689)
Cash flows expected to be collected		4,907
Accretable yield		(614)
Total purchased credit-impaired loan acquired		$ 4,293

BUSINESS COMBINATIONS - Pro-for

BUSINESS COMBINATIONS - Pro-forma information (Details) - Gulf Shore Banc shares Inc [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Net interest income	$ 196,259	$ 170,363
Net income available to common shareholders	$ 51,274	$ 41,594
EPS - basic (in dollars per share)	$ 1.11	$ 0.97
EPS - diluted (in dollars per share)	$ 1.09	$ 0.96