Seacoast Banking Corporation of Florida (SBCF) 10-Q 8 May 18 2018 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information	3 Months Ended
	Mar. 31, 2018shares
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Entity Registrant Name	SEACOAST BANKING CORP OF FLORIDA
Entity Central Index Key	730,708
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Trading Symbol	SBCF
Entity Common Stock, Shares Outstanding	46,983,165

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands		Mar. 31, 2018	Dec. 31, 2017
ASSETS
Cash and due from banks		$ 129,065	$ 104,039
Interest bearing deposits with other banks		6,794	5,465
Total cash and cash equivalents		135,859	109,504
Time deposits with other banks		12,553	12,553
Debt securities:
Available for sale (at fair value)		982,958	949,460
Held to maturity (fair value: $391,867 at March 31, 2018 and $414,470 at December 31, 2017)		400,647	416,863
Total debt securities		1,383,605	1,366,323
Loans held for sale (at fair value)		20,887	24,306
Loans	[1]	3,897,125	3,817,377
Less: Allowance for loan losses		(28,118)	(27,122)
Loans, net of allowance for loan losses		3,869,007	3,790,255
Bank premises and equipment, net		64,577	66,883
Other real estate owned		10,288	7,640
Goodwill		148,555	147,578
Other intangible assets, net		18,246	19,099
Bank owned life insurance		120,654	123,981
Net deferred tax assets		24,427	25,417
Other assets		94,443	116,590
TOTAL ASSETS		5,903,101	5,810,129
LIABILITIES
Deposits		4,719,543	4,592,720
Securities sold under agreements to repurchase		173,249	216,094
Federal Home Loan Bank (FHLB) borrowings		208,000	211,000
Subordinated debt		70,591	70,521
Other liabilities		29,857	30,130
TOTAL LIABILITIES		5,201,240	5,120,465
SHAREHOLDERS' EQUITY
Common stock, par value $0.10 per share, authorized 60,000,000 shares, issued 46,994,545 and outstanding 46,983,165 shares at March 31, 2018 and issued 47,032,259 and outstanding 46,917,735 shares at December 31, 2017		4,698	4,693
Other shareholders' equity		697,163	684,971
TOTAL SHAREHOLDERS' EQUITY		701,861	689,664
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY		$ 5,903,101	$ 5,810,129
[1]	Net loan balances as of March 31, 2018 and December 31, 2017 include deferred costs of $13.9 million and $12.9 million for each period, respectively.

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Held for Investment, Fair Value, Total	$ 391,867	$ 414,470
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	46,994,545	47,032,259
Common stock, shares outstanding	46,983,165	46,917,735

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest and fees on loans	$ 45,257	$ 31,891
Interest and dividends on securities	9,604	8,374
Interest on interest bearing deposits and other investments	616	510
TOTAL INTEREST INCOME	55,477	40,775
Interest on deposits	1,538	624
Interest on time certificates	2,179	566
Noninterest expenses
Interest on borrowed money	1,998	1,420
TOTAL INTEREST EXPENSE	5,715	2,610
NET INTEREST INCOME	49,762	38,165
Provision for loan losses	1,085	1,304
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	48,677	36,861
Noninterest income
Other income	12,398	9,905
Securities losses, net	(102)	0
TOTAL NONINTEREST INCOME (Note H)	12,296	9,905
TOTAL NONINTEREST EXPENSES (Note H)	37,164	34,746
INCOME BEFORE INCOME TAXES	23,809	12,020
Provision for income taxes	5,782	4,094
NET INCOME	$ 18,027	$ 7,926
SHARE DATA
Net income diluted (in dollars per share)	$ 0.38	$ 0.2
Net income basic (in dollars per share)	0.38	0.2
Cash dividends declared (in dollars per share)	$ 0	$ 0
Average shares outstanding - diluted (in shares)	47,688,388	39,498,835
Average shares outstanding - basic (in shares)	46,951,829	38,839,284

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
NET INCOME	$ 18,027	$ 7,926
Other comprehensive income (loss):
Unrealized (losses) gains on securities available for sale	(11,023)	3,175
Amortization of unrealized losses on securities transferred to held to maturity, net	116	122
Income tax effect on other comprehensive income	2,898	(1,268)
Total other comprehensive (loss) income	(8,009)	2,029
COMPREHENSIVE INCOME	$ 10,018	$ 9,955

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 18,027	$ 7,926
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	1,568	1,341
Amortization of premiums and discounts on securities, net	742	1,056
Other amortization and accretion, net	(406)	268
Stock based compensation	1,454	1,315
Origination of loans designated for sale	(78,156)	(47,149)
Sale of loans designated for sale	83,459	46,603
Provision for loan losses	1,085	1,304
Deferred income taxes	4,707	3,860
Gains on sale of loans	(1,884)	(815)
Losses (gains) on sale and write-downs of other real estate owned	1	(346)
Losses on disposition of fixed assets	(4)	429
Changes in operating assets and liabilities, net of effects from acquired companies
Net decrease in other assets	23,567	324
Net (decrease) increase in other liabilities	(273)	647
Net cash provided by operating activities	53,887	16,763
CASH FLOWS FROM INVESTING ACTIVITIES
Maturities and repayments of debt securities available for sale	27,296	54,783
Maturities and repayments of debt securities held to maturity	16,085	25,171
Purchases of debt securities available for sale	(72,311)	(11,116)
Purchases of debt securities held to maturity	0	(31,963)
Net new loans and principal repayments	(84,063)	(94,262)
Proceeds from the sale of other real estate owned	3,300	2,417
Proceeds from sale of FHLB and Federal Reserve Bank Stock	10,540	9,053
Purchase of FHLB and Federal Reserve Stock	(13,027)	(4,935)
Purchase of VISA Class B stock	0	(6,180)
Redemption of bank owned life insurance	4,232	0
Additions to bank premises and equipment	(1,288)	(1,697)
Net cash used in investing activities	(109,236)	(58,729)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase in deposits	126,823	155,423
Net decrease in federal funds purchased and repurchase agreements	(42,845)	(21,095)
Net decrease in FHLB borrowings	(3,000)	(113,000)
Issuance of common stock, net of related expense	0	55,660
Stock based employee benefit plans	726	171
Dividends paid	0	0
Net cash provided by financing activities	81,704	77,159
Net increase in cash and cash equivalents	26,355	35,193
Cash and cash equivalents at beginning of period	109,504	109,644
Cash and cash equivalents at end of period	135,859	144,837
Supplemental disclosure of non cash investing activities:
Transfers from loans to other real estate owned	3,919	0
Transfers from bank premises to other real estate owned	$ 2,030	$ 0

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
BASIS OF PRESENTATION	Note A – Basis of Presentation Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three-month period ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018 or any other period. For further information, refer to the consolidated financial statements and footnotes thereto included in the Company’s annual report on Form 10-K for the year ended December 31, 2017. Adoption of new accounting pronouncements On January 1, 2018, we adopted Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers,” and all the related amendments (collectively, “ASC 606”) using the modified retrospective approach applied to all contracts in place at that date. Adoption had no material impact on the Company’s consolidated financial statements including no change to the amount or timing of revenue recognized for contracts within the scope of the new standard. Activity in the scope of the new standard includes: ⋅ Service Charges on Deposits ⋅ Trust Fees: ⋅ Brokerage Commissions and Fees The Company earns commissions and fees from investment brokerage services provided to its customers through an arrangement with a third-party service provider. Commissions received from the third-party service provider are recorded monthly and are based upon customer activity. Fees are earned over time and accrued monthly as services are provided. The Company acts as an agent in this arrangement and therefore presents the brokerage commissions and fees net of related costs. ⋅ Interchange Income 0.1 Use of Estimates The preparation of these condensed consolidated financial statements required the use of certain estimates by management in determining the Company’s assets, liabilities, revenues and expenses. Actual results could differ from those estimates. Specific areas, among others, requiring the application of management’s estimates include determination of the allowance for loan losses, the valuation of investment securities available for sale, fair value of impaired loans, contingent liabilities, fair value of other real estate owned, and the valuation of deferred tax assets. Actual results could differ from those estimates.

Recently Issued Accounting Stan

Recently Issued Accounting Standards, Not adopted as of January 1, 2018	3 Months Ended
	Mar. 31, 2018
Accounting Changes and Error Corrections [Abstract]
RECENTLY ISSUED ACCOUNTING STANDARDS	Note B – Recently Issued Accounting Standards, Not adopted as of January 1, 2018 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 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 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 2017-08, 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, 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. 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.

Earnings per Share

Earnings per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
BASIC AND DILUTED EARNINGS PER COMMON SHARE	Note C – Earnings per Share 274,000 84,000 Three Months Ended March 31, 2018 2017 (In thousands, except per share data) Basic earnings per share Net income $ 18,027 $ 7,926 Average common stock outstanding 46,951,829 38,839,284 Net income per share $ 0.38 $ 0.20 Diluted earnings per share Net income $ 18,027 $ 7,926 Average common stock outstanding 46,951,829 38,839,284 Add: Dilutive effect of employee restricted stock and stock options 736,559 659,551 Average diluted stock outstanding 47,688,388 39,498,835 Net income per share $ 0.38 $ 0.20 The dilutive impact of restricted stock and stock options is calculated under the treasury method. On February 21, 2017, the Company completed a public offering of 2,702,500 55.7 6,210,000

Securities

Securities	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Securities	Note D -Securities March 31, 2018 Gross Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) Debt securities available for sale U.S. Treasury securities and obligations of U.S. Government Entities $ 8,697 $ 214 $ (14) $ 8,897 Mortgage-backed securities of U.S. Government Sponsored Entities 328,521 225 (8,861) 319,885 Collateralized mortgage obligations of U.S. Government Sponsored Entities 281,335 70 (8,127) 273,278 Commercial mortgage backed securities of U.S. Government Sponsored Entities 16,183 8 (150) 16,041 Private mortgage backed securities 18,070 379 0 18,449 Private collateralized mortgage obligations 44,374 608 (266) 44,716 Collateralized loan obligations 256,058 731 (3) 256,786 Obligations of state and political subdivisions 45,003 384 (481) 44,906 Totals $ 998,241 $ 2,619 $ (17,902) $ 982,958 Debt securities held to maturity Mortgage-backed securities of U.S. Government Sponsored Entities $ 168,462 $ 0 $ (3,524) $ 164,938 Collateralized mortgage obligations of U.S. Government Sponsored Entities 174,080 0 (5,841) 168,239 Commercial mortgage backed securities of U.S. Government Sponsored Entities 17,487 412 0 17,899 Collateralized loan obligations 35,600 211 0 35,811 Private collateralized mortgage obligations 5,018 9 (47) 4,980 Totals $ 400,647 $ 632 $ (9,412) $ 391,867 December 31, 2017 Gross Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) Debt securities available for sale U.S. Treasury securities and obligations of U.S. Government 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 Totals $ 953,720 $ 4,202 $ (8,462) $ 949,460 Debt 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 collateralized mortgage obligations 5,337 9 (53) 5,293 Totals $ 416,863 $ 1,819 $ (4,212) $ 414,470 There were no sales of securities during the three month periods ended March 31, 2018 and March 31, 2017, respectively. Included in “Securities losses, net” for the three month period ended March 31, 2018, is a $ 0.1 At March 31, 2018, debt securities with a fair value of $ 178.8 173.2 Held to Maturity Available for Sale Amortized Fair Amortized Fair Cost Value Cost Value (In thousands) Due in less than one year $ 0 $ 0 $ 7,635 $ 7,849 Due after one year through five years 3,600 3,602 34,651 34,673 Due after five years through ten years 32,000 32,209 254,328 255,151 Due after ten years 0 0 13,144 12,916 35,600 35,811 309,758 310,589 Mortgage-backed securities of U.S. Government Sponsored Entities 168,462 164,938 328,521 319,885 Collateralized mortgage obligations of U.S. Government Sponsored Entities 174,080 168,239 281,335 273,278 Commercial mortgage backed securities of U.S. Government Sponsored Entities 17,487 17,899 16,183 16,041 Private mortgage-backed securities 0 0 18,070 18,449 Private collateralized mortgage obligations 5,018 4,980 44,374 44,716 $ 400,647 $ 391,867 $ 998,241 $ 982,958 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. March 31, 2018 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 Entities $ 895 $ (14) $ 0 $ 0 $ 895 $ (14) Mortgage-backed securities of U.S. Government Sponsored Entities 257,394 (4,629) 214,042 (7,756) 471,436 (12,385) Collateralized mortgage obligations of U.S. Government Sponsored Entities 242,193 (5,403) 188,936 (8,565) 431,129 (13,968) Commercial mortgage backed securities of U.S. Government Sponsored Entities 7,925 (78) 3,032 (72) 10,957 (150) Private collateralized mortgage obligations 762 (1) 19,586 (312) 20,348 (313) Collateralized loan obligations 12,747 (3) 0 0 12,747 (3) Obligations of state and political subdivisions 18,722 (227) 12,488 (254) 31,210 (481) Total temporarily impaired securities $ 540,638 $ (10,355) $ 438,084 $ (16,959) $ 978,722 $ (27,314) 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 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 (5,954) 375,538 (7,461) Commercial mortgage backed securities of U.S. Government Sponsored Entities 5,076 (25) 1,049 (9) 6,125 (34) 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) Total temporarily impaired securities $ 326,177 $ (2,134) $ 440,333 $ (10,540) $ 766,510 $ (12,674) The two tables above include debt securities held to maturity that were transferred from available for sale into held to maturity during 2014. Those securities had unrealized losses of $ 3.0 1.1 63.3 22.9 0.8 0.2 14.1 15.3 0.6 0.4 At March 31, 2018, the Company had $ 26.5 913.5 At March 31, 2018, $ 0.3 30- and 15-year fixed and 10/1 adjustable rate mortgage At March 31, 2018, obligations of state and political subdivisions with a fair value of $ 31.2 0.5 As of March 31, 2018, the Company does not intend to sell debt 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 March 31, 2018. Included in other assets is $ 35.0 6.2 The Company holds 11,330 1.6483 18,675

Loans

Loans	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
LOANS	Note E - Loans March 31, 2018 Portfolio Loans PCI Loans PULs Total (In thousands) Construction and land development $ 253,416 $ 1,150 $ 119,678 $ 374,244 Commercial real estate 1,197,152 9,855 438,232 1,645,239 Residential real estate 888,534 1,869 174,749 1,065,152 Commercial and financial 536,321 819 79,562 616,702 Consumer 188,195 0 7,593 195,788 NET LOAN BALANCES 1 $ 3,063,618 $ 13,693 $ 819,814 $ 3,897,125 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 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 (1) Net loan balances as of March 31, 2018 and December 31, 2017 include deferred costs of $ 13.9 12.9 March 31, 2018 Accruing Accruing Accruing Greater Total 30-59 Days 60-89 Days Than Financing Current Past Due Past Due 90 Days Nonaccrual Receivables (In thousands) Portfolio Loans Construction and land development $ 253,189 $ 0 $ 0 $ 0 $ 227 $ 253,416 Commercial real estate 1,194,839 1,296 0 0 1,017 1,197,152 Residential real estate 877,943 1,179 82 0 9,330 888,534 Commerical and financial 530,801 3,149 173 229 1,969 536,321 Consumer 187,818 218 74 0 85 188,195 Total 3,044,590 5,842 329 229 12,628 3,063,618 Purchased Unimpaired Loans Construction and land development 119,539 139 0 0 0 119,678 Commercial real estate 436,589 609 326 0 708 438,232 Residential real estate 170,128 527 0 0 4,094 174,749 Commerical and financial 79,400 2 0 0 160 79,562 Consumer 7,588 0 5 0 0 7,593 Total 813,244 1,277 331 0 4,962 819,814 Purchased Credit Impaired Loans Construction and land development 1,150 0 0 0 0 1,150 Commercial real estate 9,427 0 0 0 428 9,855 Residential real estate 548 0 0 0 1,321 1,869 Commerical and financial 819 0 0 0 0 819 Consumer 0 0 0 0 0 0 Total 11,944 0 0 0 1,749 13,693 Total Loans $ 3,869,778 $ 7,119 $ 660 $ 229 $ 19,339 $ 3,897,125 December 31, 2017 Accruing Accruing Accruing Greater Total 30-59 Days 60-89 Days Than Financing Current Past Due Past Due 90 Days Nonaccrual Receivables (In thousands) 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 Commerical and financial 507,501 2,776 26 0 2,127 512,430 Consumer 178,676 52 0 0 98 178,826 Total 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 Commerical and financial 92,315 54 0 0 321 92,690 Consumer 10,610 0 0 0 0 10,610 Total 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 Commerical and financial 844 0 0 0 50 894 Consumer 0 0 0 0 0 0 Total 11,861 642 0 0 4,914 17,417 Total Loans $ 3,788,998 $ 8,082 $ 773 $ 0 $ 19,524 $ 3,817,377 The Company utilizes an internal asset classification system as a means of reporting problem and potential problem loans. Under the Company’s risk rating system, the Company classifies problem and potential problem loans as “Special Mention,” “Substandard,” and “Doubtful” and these loans are monitored on an ongoing basis. 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 include those characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. Loans classified as Substandard may require a specific allowance. Loans classified as Doubtful 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 on loans classified as Doubtful is generally charged off. Risk ratings are updated any time the situation warrants. Loans that are not problem or potential problem loans are considered to be pass-rated loans and risk grades are recalculated at least annually by the loan relationship manager. March 31, 2018 Special Pass Mention Substandard Doubtful Total (In thousands) Construction and land development $ 363,778 $ 8,471 $ 1,995 $ 0 $ 374,244 Commercial real estate 1,596,893 29,421 18,925 0 1,645,239 Residential real estate 1,036,786 2,456 25,910 0 1,065,152 Commerical and financial 608,025 3,056 4,067 1,554 616,702 Consumer 193,867 1,333 588 0 195,788 Total $ 3,799,349 $ 44,737 $ 51,485 $ 1,554 $ 3,897,125 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 Commerical and financial 593,689 3,237 8,838 250 606,014 Consumer 189,354 0 82 0 189,436 Total $ 3,722,027 $ 47,545 $ 47,494 $ 311 $ 3,817,377 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 non-accretable difference. March 31, (In thousands) 2018 2017 Beginning balance $ 3,699 $ 3,807 Additions 0 0 Deletions (43) 0 Accretion (443) (365) Reclassification from non-accretable difference 339 68 Ending balance $ 3,552 $ 3,510 Troubled Debt Restructured Loans The Company’s Troubled Debt Restructuring (“TDR”) concessions granted generally do not include forgiveness of principal balances, but may include interest rate reductions, an extension of the amortization period and/or converting the loan to interest only for a limited period of time. Loan modifications are not reported in calendar years after modification if the loans were modified at an interest rate equal to the yields of new loan originations with comparable risk and the loans are performing based on the terms of the restructuring agreements. Most loans prior to modification were classified as an impaired loan and the allowance for loan losses is determined in accordance with Company policy. Pre- Post- Modification Modification Number Outstanding Outstanding Specific Valuation of Recorded Recorded Reserve Allowance Contracts Investment Investment Recorded Recorded (In thousands) March 31, 2018 Total loans 0 $ 0 $ 0 $ 0 $ 0 March 31, 2017 Construction and land development 1 $ 52 $ 46 $ 0 $ 6 Total loans 1 $ 52 $ 46 $ 0 $ 6 During the three months end March 31, 2018 and March 31, 2017, 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 and specific allowance for loan loss is 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. March 31, 2018 Unpaid Related Recorded Principal Valuation Investment Balance Allowance (In thousands) Impaired Loans with No Related Allowance Recorded: Construction and land development $ 213 $ 497 $ 0 Commercial real estate 2,777 4,196 0 Residential real estate 14,156 19,042 0 Commercial and financial 166 177 0 Consumer 93 134 0 Impaired Loans with an Allowance Recorded: Construction and land development 238 251 26 Commercial real estate 4,749 4,749 178 Residential real estate 7,744 7,932 1,094 Commercial and financial 2,197 878 1,406 Consumer 275 279 41 Total Impaired Loans Construction and land development 451 748 26 Commercial real estate 7,526 8,945 178 Residential real estate 21,900 26,974 1,094 Commercial and financial 2,363 1,055 1,406 Consumer 368 413 41 Total $ 32,608 $ 38,135 $ 2,745 December 31, 2017 Unpaid Related Recorded Principal Valuation Investment Balance Allowance (In thousands) 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 Impaired loans also include TDRs where concessions have been granted to borrowers who have experienced financial difficulty. At March 31, 2018 and at December 31, 2017, accruing TDRs totaled $ 14.8 15.6 Average impaired loans for the three months ended March 31, 2018 and 2017 were $ 31.1 30.4 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 three month periods ended March 31, 2018, and 2017, the Company recorded $ 0.4 For impaired loans whose impairment is measured based on the present value of expected future cash flows, a total of $ 88,000 61,000

Allowance for Loan Losses

Allowance for Loan Losses	3 Months Ended
	Mar. 31, 2018
Loans and Leases Receivable Disclosure [Abstract]
Impaired Loans and Allowance for Loan Losses	Note F — Allowance for Loan Losses March 31, 2018 Provision TDR Beginning for Loan Charge- Allowance Ending Balance Losses Offs Recoveries Adjustments Balance (In thousands) Construction &; land development $ 1,642 $ 411 $ 0 $ 5 $ 0 $ 2,058 Commercial real estate 9,285 (575) 0 147 (15) 8,842 Residential real estate 7,131 788 0 200 (72) 8,047 Commercial and financial 7,297 270 (198) 24 0 7,393 Consumer 1,767 191 (307) 128 (1) 1,778 Totals $ 27,122 $ 1,085 $ (505) $ 504 $ (88) $ 28,118 March 31, 2017 Provision TDR Beginning for Loan Charge- Allowance Ending Balance Losses Offs Recoveries Adjustments Balance (In thousands) Construction &; land development $ 1,219 $ 66 $ 0 $ 69 $ (2) $ 1,352 Commercial real estate 9,273 495 0 107 (14) 9,861 Residential real estate 7,483 (393) (122) 128 (32) 7,064 Commercial and financial 3,636 1,073 (121) 47 0 4,635 Consumer 1,789 63 (259) 58 (1) 1,650 Totals $ 23,400 $ 1,304 $ (502) $ 409 $ (49) $ 24,562 March 31, 2018 Individually Evaluated for Collectively Evaluated for Impairment Impairment Total Recorded Associated Recorded Associated Recorded Associated Investment Allowance Investment Allowance Investment Allowance (In thousands) Construction &; land development $ 451 $ 26 $ 372,643 $ 2,032 $ 373,094 $ 2,058 Commercial real estate 7,526 178 1,627,858 8,664 1,635,384 8,842 Residential real estate 21,900 1,094 1,041,383 6,953 1,063,283 8,047 Commercial and financial 2,363 1,406 613,520 5,987 615,883 7,393 Consumer 368 41 195,420 1,737 195,788 1,778 Totals $ 32,608 $ 2,745 $ 3,850,824 $ 25,373 $ 3,883,432 $ 28,118 At December 31, 2017 Individually Evaluated for Collectively Evaluated for Impairment Impairment Total Recorded Associated Recorded Associated Recorded Associated Investment Allowance Investment Allowance Investment Allowance (In thousands) Construction &; 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 Totals $ 30,291 $ 2,402 $ 3,769,670 $ 24,720 $ 3,799,961 $ 27,122 Loans collectively evaluated for impairment reported at March 31, 2018 included acquired loans that are not PCI loans. At March 31, 2018, the remaining fair value adjustments for loans acquired was approximately $ 17.4 2.1 19.4 2.2 March 31, 2018 December 31, 2017 PCI Loans Individually Evaluated for Impairment Recorded Associated Recorded Associated (Dollars in thousands) Investment Allowance Investment Allowance Construction &; land development $ 1,150 $ 0 $ 1,121 $ 0 Commercial real estate 9,855 0 9,776 0 Residential real estate 1,869 0 5,626 0 Commercial and financial 819 0 894 0 Consumer 0 0 0 0 $ 13,693 $ 0 $ 17,417 $ 0

Securities Sold Under Agreement

Securities Sold Under Agreements to Repurchase	3 Months Ended
	Mar. 31, 2018
Brokers and Dealers [Abstract]
SECURITIES SOLD UNDER AGREEMENTS TO REPURCHASE	Note G – Securities Sold Under Agreements to Repurchase Securities sold under agreements to repurchase are accounted for as secured borrowings. For securities sold under agreements to repurchase, the Company is obligated to provide additional collateral in the event of a significant decline in fair value of collateral pledged. March 31, December 31, 2018 2017 (In thousands) Fair-Value of Pledged Securities - overnight and continuous Mortgage backed securities and collateralized mortgage obligations of U.S. Government Sponsored Entities $ 173,249 $ 216,094

Noninterest Income and Expense

Noninterest Income and Expense	3 Months Ended
	Mar. 31, 2018
Noninterest Income and Expenses [Abstract]
NONINTEREST INCOME AND EXPENSE	Note H – Noninterest Income and Expense Detail of noninterest income and expenses follows: March 31, 2018 2017 (In thousands) Noninterest income Service charges on deposit accounts $ 2,672 $ 2,422 Trust fees 1,021 880 Mortgage banking fees 1,402 1,552 Brokerage commissions and fees 359 377 Marine finance fees 573 134 Interchange income 2,942 2,494 BOLI income 1,056 733 Other income 2,373 1,313 12,398 9,905 Securities losses, net (102) 0 TOTAL $ 12,296 $ 9,905 Noninterest expense Salaries and wages $ 15,381 $ 15,369 Employee benefits 3,081 3,068 Outsourced data processing costs 3,679 3,269 Telephone/data lines 612 532 Occupancy 3,117 3,157 Furniture and equipment 1,457 1,391 Marketing 1,252 922 Legal and professional fees 1,973 2,132 FDIC assessments 598 570 Amortization of intangibles 989 719 Net losses (gains) and disposition expense on other real estate owned 192 (293) Other 4,833 3,910 TOTAL $ 37,164 $ 34,746

Equity Capital

Equity Capital	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
EQUITY CAPITAL	Note I – Equity Capital The Company is well capitalized and at March 31, 2018, the Company and the Company’s principal banking subsidiary, Seacoast National Bank, or “Seacoast Bank”, met the common equity Tier 1 capital ratio (CET1) regulatory threshold of 6.5

Contingencies

Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
CONTINGENCIES	Note J - Contingencies The Company and its subsidiaries, because of the nature of their businesses, are at all times subject to 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 material adverse effect on the Company’s consolidated financial condition, operating results or cash flows, although no assurance can be given with respect to the ultimate outcome of any such claim or litigation.

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
FAIR VALUE	Note K – Fair Value Under ASC 820, fair value measurements for items measured at fair value on a recurring and nonrecurring basis at March 31, 2018 and December 31, 2017 included: Quoted Prices in Active Significant Markets for Other Significant Identical Observable Unobservable Fair Value Assets Inputs Inputs Measurements (Level 1) (Level 2) (Level 3) (In thousands) March 31, 2018: Available for sale debt securities (1) $ 982,958 $ 100 $ 982,858 $ 0 Loans held for sale (2) 20,887 0 20,887 0 Loans (3) 7,139 0 6,607 532 Other real estate owned (4) 10,288 0 3,826 6,462 Equity securities (5) 6,242 6,242 0 0 December 31, 2017: Available for sale debt securities (1)(5) $ 949,460 $ 100 $ 949,360 $ 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 Equity securities (5) 6,344 6,344 0 0 (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 F. 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 (5) Prior to adoption of ASU 2016-01 on January 1, 2018, an investment in shares of a mutual fund that invests primarily in CRA-qualified debt securities was classified as an available for sale security. Beginning in 2018, this security is reported at fair value in Other Assets. Fair value is determined based on market quotations. Loans held for sale : Fair values are based upon estimated values received from independent third party purchasers. These loans are intended for sale and the Company believes that the fair value is the best indicator of the resolution of these loans. Interest income is recorded based on the contractual terms of the loan and in accordance with the Company’s policy on loans held for investment. None of the loans are 90 days or more past due or on nonaccrual as of March 31, 2018 and December 31, 2017. The aggregate fair value and contractual balance of loans for sale as of March 31, 2018 and December 31, 2017 is as follows: March 31, December 31, (In thousands) 2018 2017 Aggregate fair value $ 20,887 $ 24,306 Contractual balance 20,303 23,627 Excess 584 679 Loans : Level 2 loans consist of impaired real estate loans which are collateral dependent 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. Level 3 loans consist commercial and commercial real estate impaired loans. For these 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 March 31, 2018, the range of capitalization rates utilized to determine fair value of the underlying collateral averaged approximately 7.6%. Adjustments to comparable sales may be made by an appraiser to reflect local market conditions or other economic factors and may result in changes in the fair value of an asset over time. As such, the fair value of these impaired loans is considered level 3 in the fair value hierarchy. Impaired loans measured at fair value total $7.1 million with a specific reserve of $2.7 million at March 31, 2018, compared to $4.2 million with a specific reserve of $2.4 million at December 31, 2017. Other real estate owned : When appraisals are used to determine fair value and the appraisals are based on a market approach, the fair value of other real estate owned (“OREO”) is classified as a level 2 input. 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-end valuation process. There were no such transfers during the three months ended March 31, 2018 and 2017. For loans classified as level 3, reductions totaled $0.2 million for the first three months of 2018, primarily a transfer to OREO and lesser amounts for principal payments. For OREO classified as level 3 during the first three months of 2018, no foreclosed loans were added, migrated branches taken out of service added $2.0 million and reductions consisting of sales totaled $3.1 million. The carrying amount and fair value of the Company’s other significant financial instruments that are not measured at fair value on a recurring basis in the balance sheet as of March 31, 2018 and December 31, 2017 is as follows: Quoted Prices in Active Significant Markets for Other Significant Identical Observable Unobservable Carrying Assets Inputs Inputs Amount (Level 1) (Level 2) (Level 3) ( In thousands) March 31, 2018: Financial Assets Debt securities held to maturity (1) $ 400,647 $ 0 $ 391,867 $ 0 Time deposits with other banks 12,553 0 0 12,475 Loans, net 3,861,868 0 0 3,852,712 Financial Liabilities Deposit liabilities 4,719,543 0 0 4,713,262 Subordinated debt 70,591 0 61,591 0 December 31, 2017: Financial Assets Debt 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 Deposit liabilities 4,592,720 0 0 4,588,515 Subordinated debt 70,521 0 61,530 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 due from banks, interest bearing deposits with other banks, federal funds purchased, debt securities sold under agreements to repurchase, maturing within 30 days, and FHLB borrowings. 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 March 31, 2018 and December 31, 2017: Debt securities : U.S. Treasury debt securities are reported at fair value utilizing Level 1 inputs. Other debt securities are reported at fair value utilizing Level 2 inputs. 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 flow analyses, using observable market data where available. The Company reviews the prices supplied by independent pricing services, as well as their underlying pricing methodologies, for reasonableness and to ensure such prices are aligned with traditional pricing matrices. The fair value of collateralized loan obligations is determined from broker quotes. From time to time, the Company will validate, on a sample basis, prices supplied by the independent pricing service by comparison to prices obtained from other brokers and third-party sources or derived using internal models. Loans Deposit Liabilities : The fair value of demand deposits, savings accounts and money market deposits is the amount payable at the reporting date. The fair value of fixed maturity certificates of deposit is estimated using the rates currently offered for funding of similar remaining maturities.

Business Combinations

Business Combinations	3 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
Business Combinations	Note L - Business Combinations Acquisition of GulfShore Bancshares, Inc. On April 7, 2017, the Company completed its acquisition of GulfShore Bancshares Inc., the parent company of GulfShore Bank. Simultaneously, upon completion of the merger, GulfShore’s wholly owned subsidiary bank, GulfShore Bank (“GulfShore”), was merged with and into Seacoast Bank. GulfShore, headquartered in Tampa, Florida, operated 3 branches in Tampa and St. Petersburg, all of which have been retained as Seacoast locations. 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 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). (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 Initially Reported Period As Adjusted April 7, 2017 Adjustments April 7, 2017 (In thousands) Assets: Cash $ 55,540 $ 0 $ 55,540 Investment securities 316 0 316 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 8,572 0 8,572 $ 357,649 $ 0 $ 357,649 Liabilities: Deposits $ 285,350 $ 0 $ 285,350 Other liabilities 1,382 0 1,382 $ 286,732 $ 0 $ 286,732 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 factors, 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 (“NorthStar”), 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 12.3 Measurement Initially Reported Period As Adjusted October 20 2017 Adjustments October 20, 2017 (In thousands) Assets: Cash $ 5,485 $ 0 $ 5,485 Investment securities 56,123 0 56,123 Loans, net 136,832 0 136,832 Fixed assets 2,637 0 2,637 Core deposit intangibles 1,275 0 1,275 Goodwill 12,404 (99) 12,305 Other assets 1,522 99 1,621 $ 216,278 $ 0 $ 216,278 Liabilities: Deposits $ 182,443 $ 0 $ 182,443 Other liabilities 980 0 980 $ 183,423 $ 0 $ 183,423 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 factors. 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. (In thousands) October 20, 2017 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 $ 357 270 269 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 34.8 Measurement Initially Reported Period As Adjusted November 3, 2017 Adjustments November 3, 2017 (In thousands) Assets: Cash $ 9,301 $ 0 $ 9,301 Investment securities 22,098 0 22,098 Loans, net 272,090 (1,772) 270,318 Fixed assets 7,641 0 7,641 Core deposit intangibles 2,523 0 2,523 Goodwill 33,428 1,323 34,751 Other assets 9,909 449 10,358 $ 356,990 $ 0 $ 356,990 Liabilities: Deposits $ 268,633 $ 0 $ 268,633 Other liabilities 16,351 0 16,351 $ 284,984 $ 0 $ 284,984 As Adjusted (In thousands) Book Balance Fair Value Loans: Single family residential real estate $ 30,153 $ 30,990 Commercial real estate 134,705 132,089 Construction/development/land 69,686 67,425 Commercial loans 36,076 35,876 Consumer and other loans 179 172 Purchased Credit Impaired 4,768 3,766 Total acquired loans $ 275,567 $ 270,318 For the loans acquired we first segregated all acquired loans with specifically identified credit deficiency factors. 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 Three Months (In thousands, except per share amounts) 2017 Net interest income $ 45,987 Net income 11,285 EPS - basic 0.25 EPS - diluted 0.25

Basis of Presentation (Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three-month period ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018 or any other period. For further information, refer to the consolidated financial statements and footnotes thereto included in the Company’s annual report on Form 10-K for the year ended December 31, 2017.
Recently adopted Accounting Standard	Adoption of new accounting pronouncements On January 1, 2018, we adopted Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers,” and all the related amendments (collectively, “ASC 606”) using the modified retrospective approach applied to all contracts in place at that date. Adoption had no material impact on the Company’s consolidated financial statements including no change to the amount or timing of revenue recognized for contracts within the scope of the new standard. Activity in the scope of the new standard includes: ⋅ Service Charges on Deposits ⋅ Trust Fees: ⋅ Brokerage Commissions and Fees The Company earns commissions and fees from investment brokerage services provided to its customers through an arrangement with a third-party service provider. Commissions received from the third-party service provider are recorded monthly and are based upon customer activity. Fees are earned over time and accrued monthly as services are provided. The Company acts as an agent in this arrangement and therefore presents the brokerage commissions and fees net of related costs. ⋅ Interchange Income 0.1
Use of Estimates	Use of Estimates The preparation of these condensed consolidated financial statements required the use of certain estimates by management in determining the Company’s assets, liabilities, revenues and expenses. Actual results could differ from those estimates. Specific areas, among others, requiring the application of management’s estimates include determination of the allowance for loan losses, the valuation of investment securities available for sale, fair value of impaired loans, contingent liabilities, fair value of other real estate owned, and the valuation of deferred tax assets. Actual results could differ from those estimates.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	For the three month periods ended March 31, 2018 and 2017, options to purchase 274,000 84,000 Three Months Ended March 31, 2018 2017 (In thousands, except per share data) Basic earnings per share Net income $ 18,027 $ 7,926 Average common stock outstanding 46,951,829 38,839,284 Net income per share $ 0.38 $ 0.20 Diluted earnings per share Net income $ 18,027 $ 7,926 Average common stock outstanding 46,951,829 38,839,284 Add: Dilutive effect of employee restricted stock and stock options 736,559 659,551 Average diluted stock outstanding 47,688,388 39,498,835 Net income per share $ 0.38 $ 0.20

Securities (Tables)

Securities (Tables)	3 Months Ended
	Mar. 31, 2018
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 March 31, 2018 and December 31, 2017 are summarized as follows: March 31, 2018 Gross Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) Debt securities available for sale U.S. Treasury securities and obligations of U.S. Government Entities $ 8,697 $ 214 $ (14) $ 8,897 Mortgage-backed securities of U.S. Government Sponsored Entities 328,521 225 (8,861) 319,885 Collateralized mortgage obligations of U.S. Government Sponsored Entities 281,335 70 (8,127) 273,278 Commercial mortgage backed securities of U.S. Government Sponsored Entities 16,183 8 (150) 16,041 Private mortgage backed securities 18,070 379 0 18,449 Private collateralized mortgage obligations 44,374 608 (266) 44,716 Collateralized loan obligations 256,058 731 (3) 256,786 Obligations of state and political subdivisions 45,003 384 (481) 44,906 Totals $ 998,241 $ 2,619 $ (17,902) $ 982,958 Debt securities held to maturity Mortgage-backed securities of U.S. Government Sponsored Entities $ 168,462 $ 0 $ (3,524) $ 164,938 Collateralized mortgage obligations of U.S. Government Sponsored Entities 174,080 0 (5,841) 168,239 Commercial mortgage backed securities of U.S. Government Sponsored Entities 17,487 412 0 17,899 Collateralized loan obligations 35,600 211 0 35,811 Private collateralized mortgage obligations 5,018 9 (47) 4,980 Totals $ 400,647 $ 632 $ (9,412) $ 391,867 December 31, 2017 Gross Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) Debt securities available for sale U.S. Treasury securities and obligations of U.S. Government 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 Totals $ 953,720 $ 4,202 $ (8,462) $ 949,460 Debt 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 collateralized mortgage obligations 5,337 9 (53) 5,293 Totals $ 416,863 $ 1,819 $ (4,212) $ 414,470
Amortized Cost and Fair Value of Securities by Contractual Maturity	The amortized cost and fair value of debt securities at March 31, 2018, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because prepayments of the underlying collateral for these securities may occur, due to the right to call or repay obligations with or without call or prepayment penalties. Securities not due at a single maturity date are shown separately. Held to Maturity Available for Sale Amortized Fair Amortized Fair Cost Value Cost Value (In thousands) Due in less than one year $ 0 $ 0 $ 7,635 $ 7,849 Due after one year through five years 3,600 3,602 34,651 34,673 Due after five years through ten years 32,000 32,209 254,328 255,151 Due after ten years 0 0 13,144 12,916 35,600 35,811 309,758 310,589 Mortgage-backed securities of U.S. Government Sponsored Entities 168,462 164,938 328,521 319,885 Collateralized mortgage obligations of U.S. Government Sponsored Entities 174,080 168,239 281,335 273,278 Commercial mortgage backed securities of U.S. Government Sponsored Entities 17,487 17,899 16,183 16,041 Private mortgage-backed securities 0 0 18,070 18,449 Private collateralized mortgage obligations 5,018 4,980 44,374 44,716 $ 400,647 $ 391,867 $ 998,241 $ 982,958
Schedule of Unrealized Loss and Fair Value on Investments	The tables below indicate the amount of debt securities with unrealized losses and the period of time for which these losses were outstanding at March 31, 2018 and December 31, 2017, respectively. March 31, 2018 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 Entities $ 895 $ (14) $ 0 $ 0 $ 895 $ (14) Mortgage-backed securities of U.S. Government Sponsored Entities 257,394 (4,629) 214,042 (7,756) 471,436 (12,385) Collateralized mortgage obligations of U.S. Government Sponsored Entities 242,193 (5,403) 188,936 (8,565) 431,129 (13,968) Commercial mortgage backed securities of U.S. Government Sponsored Entities 7,925 (78) 3,032 (72) 10,957 (150) Private collateralized mortgage obligations 762 (1) 19,586 (312) 20,348 (313) Collateralized loan obligations 12,747 (3) 0 0 12,747 (3) Obligations of state and political subdivisions 18,722 (227) 12,488 (254) 31,210 (481) Total temporarily impaired securities $ 540,638 $ (10,355) $ 438,084 $ (16,959) $ 978,722 $ (27,314) 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 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 (5,954) 375,538 (7,461) Commercial mortgage backed securities of U.S. Government Sponsored Entities 5,076 (25) 1,049 (9) 6,125 (34) 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) Total temporarily impaired securities $ 326,177 $ (2,134) $ 440,333 $ (10,540) $ 766,510 $ (12,674)

Loans (Tables)

Loans (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	March 31, 2018 Portfolio Loans PCI Loans PULs Total (In thousands) Construction and land development $ 253,416 $ 1,150 $ 119,678 $ 374,244 Commercial real estate 1,197,152 9,855 438,232 1,645,239 Residential real estate 888,534 1,869 174,749 1,065,152 Commercial and financial 536,321 819 79,562 616,702 Consumer 188,195 0 7,593 195,788 NET LOAN BALANCES 1 $ 3,063,618 $ 13,693 $ 819,814 $ 3,897,125 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 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 (1) Net loan balances as of March 31, 2018 and December 31, 2017 include deferred costs of $ 13.9 12.9
Past Due Financing Receivables	March 31, 2018 Accruing Accruing Accruing Greater Total 30-59 Days 60-89 Days Than Financing Current Past Due Past Due 90 Days Nonaccrual Receivables (In thousands) Portfolio Loans Construction and land development $ 253,189 $ 0 $ 0 $ 0 $ 227 $ 253,416 Commercial real estate 1,194,839 1,296 0 0 1,017 1,197,152 Residential real estate 877,943 1,179 82 0 9,330 888,534 Commerical and financial 530,801 3,149 173 229 1,969 536,321 Consumer 187,818 218 74 0 85 188,195 Total 3,044,590 5,842 329 229 12,628 3,063,618 Purchased Unimpaired Loans Construction and land development 119,539 139 0 0 0 119,678 Commercial real estate 436,589 609 326 0 708 438,232 Residential real estate 170,128 527 0 0 4,094 174,749 Commerical and financial 79,400 2 0 0 160 79,562 Consumer 7,588 0 5 0 0 7,593 Total 813,244 1,277 331 0 4,962 819,814 Purchased Credit Impaired Loans Construction and land development 1,150 0 0 0 0 1,150 Commercial real estate 9,427 0 0 0 428 9,855 Residential real estate 548 0 0 0 1,321 1,869 Commerical and financial 819 0 0 0 0 819 Consumer 0 0 0 0 0 0 Total 11,944 0 0 0 1,749 13,693 Total Loans $ 3,869,778 $ 7,119 $ 660 $ 229 $ 19,339 $ 3,897,125 December 31, 2017 Accruing Accruing Accruing Greater Total 30-59 Days 60-89 Days Than Financing Current Past Due Past Due 90 Days Nonaccrual Receivables (In thousands) 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 Commerical and financial 507,501 2,776 26 0 2,127 512,430 Consumer 178,676 52 0 0 98 178,826 Total 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 Commerical and financial 92,315 54 0 0 321 92,690 Consumer 10,610 0 0 0 0 10,610 Total 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 Commerical and financial 844 0 0 0 50 894 Consumer 0 0 0 0 0 0 Total 11,861 642 0 0 4,914 17,417 Total Loans $ 3,788,998 $ 8,082 $ 773 $ 0 $ 19,524 $ 3,817,377
Financing Receivable Credit Quality Indicators	March 31, 2018 Special Pass Mention Substandard Doubtful Total (In thousands) Construction and land development $ 363,778 $ 8,471 $ 1,995 $ 0 $ 374,244 Commercial real estate 1,596,893 29,421 18,925 0 1,645,239 Residential real estate 1,036,786 2,456 25,910 0 1,065,152 Commerical and financial 608,025 3,056 4,067 1,554 616,702 Consumer 193,867 1,333 588 0 195,788 Total $ 3,799,349 $ 44,737 $ 51,485 $ 1,554 $ 3,897,125 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 Commerical and financial 593,689 3,237 8,838 250 606,014 Consumer 189,354 0 82 0 189,436 Total $ 3,722,027 $ 47,545 $ 47,494 $ 311 $ 3,817,377
Contractually Required Principal And Interest Cash Payments Changes	March 31, (In thousands) 2018 2017 Beginning balance $ 3,699 $ 3,807 Additions 0 0 Deletions (43) 0 Accretion (443) (365) Reclassification from non-accretable difference 339 68 Ending balance $ 3,552 $ 3,510
Troubled Debt Restructurings on Financing Receivables	Pre- Post- Modification Modification Number Outstanding Outstanding Specific Valuation of Recorded Recorded Reserve Allowance Contracts Investment Investment Recorded Recorded (In thousands) March 31, 2018 Total loans 0 $ 0 $ 0 $ 0 $ 0 March 31, 2017 Construction and land development 1 $ 52 $ 46 $ 0 $ 6 Total loans 1 $ 52 $ 46 $ 0 $ 6
Impaired Financing Receivables	March 31, 2018 Unpaid Related Recorded Principal Valuation Investment Balance Allowance (In thousands) Impaired Loans with No Related Allowance Recorded: Construction and land development $ 213 $ 497 $ 0 Commercial real estate 2,777 4,196 0 Residential real estate 14,156 19,042 0 Commercial and financial 166 177 0 Consumer 93 134 0 Impaired Loans with an Allowance Recorded: Construction and land development 238 251 26 Commercial real estate 4,749 4,749 178 Residential real estate 7,744 7,932 1,094 Commercial and financial 2,197 878 1,406 Consumer 275 279 41 Total Impaired Loans Construction and land development 451 748 26 Commercial real estate 7,526 8,945 178 Residential real estate 21,900 26,974 1,094 Commercial and financial 2,363 1,055 1,406 Consumer 368 413 41 Total $ 32,608 $ 38,135 $ 2,745 December 31, 2017 Unpaid Related Recorded Principal Valuation Investment Balance Allowance (In thousands) 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

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	3 Months Ended
	Mar. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Credit Losses on Financing Receivables	Activity in the allowance for loan losses for the three-month period ended March 31, 2018 and 2017 is summarized as follows: March 31, 2018 Provision TDR Beginning for Loan Charge- Allowance Ending Balance Losses Offs Recoveries Adjustments Balance (In thousands) Construction &; land development $ 1,642 $ 411 $ 0 $ 5 $ 0 $ 2,058 Commercial real estate 9,285 (575) 0 147 (15) 8,842 Residential real estate 7,131 788 0 200 (72) 8,047 Commercial and financial 7,297 270 (198) 24 0 7,393 Consumer 1,767 191 (307) 128 (1) 1,778 Totals $ 27,122 $ 1,085 $ (505) $ 504 $ (88) $ 28,118 March 31, 2017 Provision TDR Beginning for Loan Charge- Allowance Ending Balance Losses Offs Recoveries Adjustments Balance (In thousands) Construction &; land development $ 1,219 $ 66 $ 0 $ 69 $ (2) $ 1,352 Commercial real estate 9,273 495 0 107 (14) 9,861 Residential real estate 7,483 (393) (122) 128 (32) 7,064 Commercial and financial 3,636 1,073 (121) 47 0 4,635 Consumer 1,789 63 (259) 58 (1) 1,650 Totals $ 23,400 $ 1,304 $ (502) $ 409 $ (49) $ 24,562
Loan Portfolio And Related Allowance	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. The Company’s loan portfolio, excluding PCI loans, and related allowance at March 31, 2018 and December 31, 2017 is shown in the following tables: March 31, 2018 Individually Evaluated for Collectively Evaluated for Impairment Impairment Total Recorded Associated Recorded Associated Recorded Associated Investment Allowance Investment Allowance Investment Allowance (In thousands) Construction &; land development $ 451 $ 26 $ 372,643 $ 2,032 $ 373,094 $ 2,058 Commercial real estate 7,526 178 1,627,858 8,664 1,635,384 8,842 Residential real estate 21,900 1,094 1,041,383 6,953 1,063,283 8,047 Commercial and financial 2,363 1,406 613,520 5,987 615,883 7,393 Consumer 368 41 195,420 1,737 195,788 1,778 Totals $ 32,608 $ 2,745 $ 3,850,824 $ 25,373 $ 3,883,432 $ 28,118 At December 31, 2017 Individually Evaluated for Collectively Evaluated for Impairment Impairment Total Recorded Associated Recorded Associated Recorded Associated Investment Allowance Investment Allowance Investment Allowance (In thousands) Construction &; 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 Totals $ 30,291 $ 2,402 $ 3,769,670 $ 24,720 $ 3,799,961 $ 27,122
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 March 31, 2018 and December 31, 2017: March 31, 2018 December 31, 2017 PCI Loans Individually Evaluated for Impairment Recorded Associated Recorded Associated (Dollars in thousands) Investment Allowance Investment Allowance Construction &; land development $ 1,150 $ 0 $ 1,121 $ 0 Commercial real estate 9,855 0 9,776 0 Residential real estate 1,869 0 5,626 0 Commercial and financial 819 0 894 0 Consumer 0 0 0 0 $ 13,693 $ 0 $ 17,417 $ 0

Securities Sold Under Agreeme24

Securities Sold Under Agreements to Repurchase (Tables)	3 Months Ended
	Mar. 31, 2018
Brokers and Dealers [Abstract]
Schedule of Securities Financing Transactions	Company securities sold under agreements to repurchase and securities pledged were as follows by collateral type and maturity as of: March 31, December 31, 2018 2017 (In thousands) Fair-Value of Pledged Securities - overnight and continuous Mortgage backed securities and collateralized mortgage obligations of U.S. Government Sponsored Entities $ 173,249 $ 216,094

Noninterest Income and Expense

Noninterest Income and Expense (Tables)	3 Months Ended
	Mar. 31, 2018
Noninterest Income and Expenses [Abstract]
Summary of Noninterest Income and Expense	Detail of noninterest income and expenses follows: March 31, 2018 2017 (In thousands) Noninterest income Service charges on deposit accounts $ 2,672 $ 2,422 Trust fees 1,021 880 Mortgage banking fees 1,402 1,552 Brokerage commissions and fees 359 377 Marine finance fees 573 134 Interchange income 2,942 2,494 BOLI income 1,056 733 Other income 2,373 1,313 12,398 9,905 Securities losses, net (102) 0 TOTAL $ 12,296 $ 9,905 Noninterest expense Salaries and wages $ 15,381 $ 15,369 Employee benefits 3,081 3,068 Outsourced data processing costs 3,679 3,269 Telephone/data lines 612 532 Occupancy 3,117 3,157 Furniture and equipment 1,457 1,391 Marketing 1,252 922 Legal and professional fees 1,973 2,132 FDIC assessments 598 570 Amortization of intangibles 989 719 Net losses (gains) and disposition expense on other real estate owned 192 (293) Other 4,833 3,910 TOTAL $ 37,164 $ 34,746

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2018
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 March 31, 2018 and December 31, 2017 included: Quoted Prices in Active Significant Markets for Other Significant Identical Observable Unobservable Fair Value Assets Inputs Inputs Measurements (Level 1) (Level 2) (Level 3) (In thousands) March 31, 2018: Available for sale debt securities (1) $ 982,958 $ 100 $ 982,858 $ 0 Loans held for sale (2) 20,887 0 20,887 0 Loans (3) 7,139 0 6,607 532 Other real estate owned (4) 10,288 0 3,826 6,462 Equity securities (5) 6,242 6,242 0 0 December 31, 2017: Available for sale debt securities (1)(5) $ 949,460 $ 100 $ 949,360 $ 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 Equity securities (5) 6,344 6,344 0 0 (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 F. 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 (5) Prior to adoption of ASU 2016-01 on January 1, 2018, an investment in shares of a mutual fund that invests primarily in CRA-qualified debt securities was classified as an available for sale security. Beginning in 2018, this security is reported at fair value in Other Assets. Fair value is determined based on market quotations.
Schedule of contractual balance and gains or losses aggregate fair value	The aggregate fair value and contractual balance of loans for sale as of March 31, 2018 and December 31, 2017 is as follows: March 31, December 31, (In thousands) 2018 2017 Aggregate fair value $ 20,887 $ 24,306 Contractual balance 20,303 23,627 Excess 584 679
Fair Value Measurements, Recurring and Nonrecurring	The carrying amount and fair value of the Company’s other significant financial instruments that are not measured at fair value on a recurring basis in the balance sheet as of March 31, 2018 and December 31, 2017 is as follows: Quoted Prices in Active Significant Markets for Other Significant Identical Observable Unobservable Carrying Assets Inputs Inputs Amount (Level 1) (Level 2) (Level 3) ( In thousands) March 31, 2018: Financial Assets Debt securities held to maturity (1) $ 400,647 $ 0 $ 391,867 $ 0 Time deposits with other banks 12,553 0 0 12,475 Loans, net 3,861,868 0 0 3,852,712 Financial Liabilities Deposit liabilities 4,719,543 0 0 4,713,262 Subordinated debt 70,591 0 61,591 0 December 31, 2017: Financial Assets Debt 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 Deposit liabilities 4,592,720 0 0 4,588,515 Subordinated debt 70,521 0 61,530 0 (1) See Note D for further detail of recurring fair value basis of individual investment categories.

Business Combinations (Tables)

Business Combinations (Tables)	3 Months Ended
	Mar. 31, 2018
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Information	Pro-forma data as of March 31, 2017 as if the acquisitions of Gulfshore, NSBC and PBCB occurred at the beginning of 2017 is as follows: Three Months (In thousands, except per share amounts) 2017 Net interest income $ 45,987 Net income 11,285 EPS - basic 0.25 EPS - diluted 0.25
Gulf Shore Banc shares Inc [Member]
Business Acquisition [Line Items]
Schedule of summarizing the purchase price calculation	The Company acquired 100 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). (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 Initially Reported Period As Adjusted April 7, 2017 Adjustments April 7, 2017 (In thousands) Assets: Cash $ 55,540 $ 0 $ 55,540 Investment securities 316 0 316 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 8,572 0 8,572 $ 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	The acquisition was accounted for under the acquisition method in accordance with ASC Topic 805, Business Combinations 12.3 Measurement Initially Reported Period As Adjusted October 20 2017 Adjustments October 20, 2017 (In thousands) Assets: Cash $ 5,485 $ 0 $ 5,485 Investment securities 56,123 0 56,123 Loans, net 136,832 0 136,832 Fixed assets 2,637 0 2,637 Core deposit intangibles 1,275 0 1,275 Goodwill 12,404 (99) 12,305 Other assets 1,522 99 1,621 $ 216,278 $ 0 $ 216,278 Liabilities: Deposits $ 182,443 $ 0 $ 182,443 Other liabilities 980 0 980 $ 183,423 $ 0 $ 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. (In thousands) October 20, 2017 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 34.8 Measurement Initially Reported Period As Adjusted November 3, 2017 Adjustments November 3, 2017 (In thousands) Assets: Cash $ 9,301 $ 0 $ 9,301 Investment securities 22,098 0 22,098 Loans, net 272,090 (1,772) 270,318 Fixed assets 7,641 0 7,641 Core deposit intangibles 2,523 0 2,523 Goodwill 33,428 1,323 34,751 Other assets 9,909 449 10,358 $ 356,990 $ 0 $ 356,990 Liabilities: Deposits $ 268,633 $ 0 $ 268,633 Other liabilities 16,351 0 16,351 $ 284,984 $ 0 $ 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 unpaid principal balance (“Book Balance”) at acquisition date. As Adjusted (In thousands) Book Balance Fair Value Loans: Single family residential real estate $ 30,153 $ 30,990 Commercial real estate 134,705 132,089 Construction/development/land 69,686 67,425 Commercial loans 36,076 35,876 Consumer and other loans 179 172 Purchased Credit Impaired 4,768 3,766 Total acquired loans $ 275,567 $ 270,318
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

Basis of Presentation - Additio

Basis of Presentation - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Reclassification of accumulated unrealized loss	$ 0.1

Earnings per Share - Additional

Earnings per Share - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 21, 2017	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		274,000	84,000
Stock Issued During Period, Shares, New Issues	2,702,500
Proceeds from Issuance of Common Stock	$ 55,700	$ 0	$ 55,660
CapGen Capital Group III LP [Member]
Stock Issued During Period, Shares, New Issues	6,210,000

Earnings per Share - Schedule o

Earnings per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Basic earnings per share
Net income	$ 18,027	$ 7,926
Average common stock outstanding	46,951,829	38,839,284
Net income per share	$ 0.38	$ 0.2
Diluted earnings per share
Net income	$ 18,027	$ 7,926
Average common stock outstanding	46,951,829	38,839,284
Add: Dilutive effect of employee restricted stock and stock options	736,559	659,551
Average diluted stock outstanding	47,688,388	39,498,835
Net income per share	$ 0.38	$ 0.2

Securities - Additional Informa

Securities - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
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	$ 35,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	978,722		$ 766,510
Accumulated unrealized losses	27,314		12,674
Available For Sale Securities Transferred To Held To Maturity Securities Unrealized Gain Loss	3,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	540,638		326,177
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	10,355		2,134
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	438,084		440,333
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 16,959		$ 10,540
Common Stock, Shares, Outstanding	46,983,165		46,917,735
Marketable Securities, Gain (Loss)	$ 100
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	978,722		$ 766,510
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	27,314		12,674
Mutual Fund [Member]
Schedule of Available-for-sale Securities [Line Items]
Other Assets	6,200
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	31,200
Accumulated unrealized losses	500
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	31,200
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	500
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]
Debt Instrument, Convertible, Conversion Price		$ 1.6483
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	1,100
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	63,300		22,900
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	800		200
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	14,100		15,300
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	600		$ 400
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,100
Carrying Amount [Member] | Repurchase Agreement [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities pledged as collateral	173,200
Collateralized Loan Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Accumulated unrealized losses	26,500
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	26,500
Private Collateralized Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	913,500
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	913,500
Seasoned Residential Collateral Of Us Government Sponsored Entities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	20,300
Accumulated unrealized losses	300
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	20,300
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	300
Public and Trust Deposits [Member] | Carrying Amount [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities pledged as collateral	$ 178,800

Securities - Amortized Cost and

Securities - Amortized Cost and Fair Value of Securities Available for Sale and Held for Investment (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	$ 998,241	$ 953,720
Gross Unrealized Gains, Available for Sale	2,619	4,202
Gross Unrealized Losses, Available for Sale	(17,902)	(8,462)
Fair Value, Available for Sale	982,958	949,460
Gross Amortized Cost, Held for Investment Securities	400,647	416,863
Gross Unrealized Gains, Held for Investment Securities	632	1,819
Gross Unrealized Losses, Held for Investment Securities	(9,412)	(4,212)
Fair Value, Held for Investment Securities	391,867	414,470
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	8,697	9,475
Gross Unrealized Gains, Available for Sale	214	274
Gross Unrealized Losses, Available for Sale	(14)	(5)
Fair Value, Available for Sale	8,897	9,744
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	328,521	318,771
Gross Unrealized Gains, Available for Sale	225	891
Gross Unrealized Losses, Available for Sale	(8,861)	(3,306)
Fair Value, Available for Sale	319,885	316,356
Gross Amortized Cost, Held for Investment Securities	168,462	172,261
Gross Unrealized Gains, Held for Investment Securities	0	746
Gross Unrealized Losses, Held for Investment Securities	(3,524)	(1,392)
Fair Value, Held for Investment Securities	164,938	171,615
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	281,335	235,466
Gross Unrealized Gains, Available for Sale	70	272
Gross Unrealized Losses, Available for Sale	(8,127)	(4,694)
Fair Value, Available for Sale	273,278	231,044
Gross Amortized Cost, Held for Investment Securities	174,080	181,280
Gross Unrealized Gains, Held for Investment Securities	0	56
Gross Unrealized Losses, Held for Investment Securities	(5,841)	(2,767)
Fair Value, Held for Investment Securities	168,239	178,569
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	16,183	16,210
Gross Unrealized Gains, Available for Sale	8	165
Gross Unrealized Losses, Available for Sale	(150)	(34)
Fair Value, Available for Sale	16,041	16,341
Gross Amortized Cost, Held for Investment Securities	17,487	17,462
Gross Unrealized Gains, Held for Investment Securities	412	705
Gross Unrealized Losses, Held for Investment Securities	0	0
Fair Value, Held for Investment Securities	17,899	18,167
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	18,070	18,056
Gross Unrealized Gains, Available for Sale	379	384
Gross Unrealized Losses, Available for Sale	0	0
Fair Value, Available for Sale	18,449	18,440
Fair Value, Held for Investment Securities	0
Private collateralized mortgage obligations [Member]
Amortized cost and fair value of securities available for sale and held for investment
Gross Amortized Cost, Available for Sale	44,374	47,045
Gross Unrealized Gains, Available for Sale	608	605
Gross Unrealized Losses, Available for Sale	(266)	(285)
Fair Value, Available for Sale	44,716	47,365
Gross Amortized Cost, Held for Investment Securities	5,018	5,337
Gross Unrealized Gains, Held for Investment Securities	9	9
Gross Unrealized Losses, Held for Investment Securities	(47)	(53)
Fair Value, Held for Investment Securities	4,980	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	256,058	263,579
Gross Unrealized Gains, Available for Sale	731	798
Gross Unrealized Losses, Available for Sale	(3)	(68)
Fair Value, Available for Sale	256,786	264,309
Gross Amortized Cost, Held for Investment Securities	35,600	40,523
Gross Unrealized Gains, Held for Investment Securities	211	303
Gross Unrealized Losses, Held for Investment Securities	0	0
Fair Value, Held for Investment Securities	35,811	40,826
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	45,003	45,118
Gross Unrealized Gains, Available for Sale	384	813
Gross Unrealized Losses, Available for Sale	(481)	(70)
Fair Value, Available for Sale	$ 44,906	$ 45,861

Securities - Amortized Cost a33

Securities - Amortized Cost and Fair Value of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Total	$ 400,647	$ 416,863
Held for Investment, Fair Value, Total	391,867	414,470
Available for Sale, Amortized Cost, Total	998,241
Available for Sale, Fair Value, Total	982,958	949,460
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	7,635
Available for Sale, Fair Value, Due in less than one year	7,849
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	3,602
Available for Sale, Amortized Cost, Due after one year through five years	34,651
Available for Sale, Fair Value, Due after one year through five years	34,673
Held for Investment, Amortized Cost, Due after five years through ten years	32,000
Held for Investment, Fair Value, Due after five years through ten years	32,209
Available for Sale, Amortized Cost, Due after five years through ten years	254,328
Available for Sale, Fair Value, Due after five years through ten years	255,151
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	13,144
Available for Sale, Fair Value, Due after ten years	12,916
Held for Investment, Amortized Cost, Total	35,600
Held for Investment, Fair Value, Total	35,811
Available for Sale, Amortized Cost, Total	309,758
Available for Sale, Fair Value, Total	310,589
Mortgage-backed securities of U.S. Government Sponsored Entities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Total	168,462
Held for Investment, Fair Value, Total	164,938	171,615
Available for Sale, Amortized Cost, Total	328,521
Available for Sale, Fair Value, Total	319,885	316,356
Collateralized Mortgage Obligations Of US Government Sponsored Entities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Total	174,080
Held for Investment, Fair Value, Total	168,239	178,569
Available for Sale, Amortized Cost, Total	281,335
Available for Sale, Fair Value, Total	273,278	231,044
Commercial mortgage backed securities of U.S. Government Sponsored Entities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Total	17,487
Held for Investment, Fair Value, Total	17,899	18,167
Available for Sale, Amortized Cost, Total	16,183
Available for Sale, Fair Value, Total	16,041	16,341
Private mortgage backed securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Total	0
Held for Investment, Fair Value, Total	0
Available for Sale, Amortized Cost, Total	18,070
Available for Sale, Fair Value, Total	18,449	18,440
Private collateralized mortgage obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held for Investment, Amortized Cost, Total	5,018
Held for Investment, Fair Value, Total	4,980	5,293
Available for Sale, Amortized Cost, Total	44,374
Available for Sale, Fair Value, Total	$ 44,716	$ 47,365

Securities - Schedule of Unreal

Securities - Schedule of Unrealized Loss and Fair Value on Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value
Less than 12 months	$ 540,638	$ 326,177
12 months or longer	438,084	440,333
Total	978,722	766,510
Unrealized Losses
Less than 12 months	(10,355)	(2,134)
12 months or longer	(16,959)	(10,540)
Total	(27,314)	(12,674)
Collateralized Loan Obligations [Member]
Fair Value
Less than 12 months	12,747	14,933
12 months or longer	0	0
Total	12,747	14,933
Unrealized Losses
Less than 12 months	(3)	(68)
12 months or longer	0	0
Total	(3)	(68)
U.S. Treasury securities and obligations of U.S. Government Sponsored Entities [Member]
Fair Value
Less than 12 months	895	1,107
12 months or longer	0	0
Total	895	1,107
Unrealized Losses
Less than 12 months	(14)	(5)
12 months or longer	0	0
Total	(14)	(5)
Mortgage-backed securities of U.S. Government Sponsored Entities [Member]
Fair Value
Less than 12 months	257,394	123,195
12 months or longer	214,042	213,590
Total	471,436	336,785
Unrealized Losses
Less than 12 months	(4,629)	(515)
12 months or longer	(7,756)	(4,183)
Total	(12,385)	(4,698)
Collateralized Mortgage Obligations Of US Government Sponsored Entities [Member]
Fair Value
Less than 12 months	242,193	176,452
12 months or longer	188,936	199,086
Total	431,129	375,538
Unrealized Losses
Less than 12 months	(5,403)	(1,507)
12 months or longer	(8,565)	(5,954)
Total	(13,968)	(7,461)
Commercial mortgage backed securities of U.S. Government Sponsored Entities [Member]
Fair Value
Less than 12 months	7,925	5,076
12 months or longer	3,032	1,049
Total	10,957	6,125
Unrealized Losses
Less than 12 months	(78)	(25)
12 months or longer	(72)	(9)
Total	(150)	(34)
Private collateralized mortgage obligations [Member]
Fair Value
Less than 12 months	762	0
12 months or longer	19,586	20,744
Total	20,348	20,744
Unrealized Losses
Less than 12 months	(1)	0
12 months or longer	(312)	(338)
Total	(313)	(338)
Obligations of state and political subdivisions [Member]
Fair Value
Less than 12 months	18,722	5,414
12 months or longer	12,488	5,864
Total	31,210	11,278
Unrealized Losses
Less than 12 months	(227)	(14)
12 months or longer	(254)	(56)
Total	$ (481)	$ (70)

Loans - Additional Information

Loans - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Troubled Debt Restructuring Outstanding	$ 14,800,000		$ 15,600,000
Loans and Leases Receivable, Impaired, Troubled Debt, Interest Income	400,000	$ 400,000
Loans and Leases Receivable, Impaired, Interest Income Recognized, Change in Present Value Attributable to Passage of Time	88,000	61,000
Impaired Financing Receivable, Average Recorded Investment	31,100,000	$ 30,400,000
PCI Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Deferred Costs, Noncurrent	$ 13,900,000		$ 12,900,000

Loans - Information Relating to

Loans - Information Relating to Loans (Details) - USD ($) $ in Thousands		Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[1]	$ 3,897,125	$ 3,817,377
Commercial and financial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		616,702	606,014
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		195,788	189,436
Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		374,244	343,125
Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		1,645,239	1,639,992
Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		1,065,152	1,038,810
Portfolio Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[1]	3,063,618	2,922,609
Portfolio Loans [Member] | Commercial and financial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		536,321	512,430
Portfolio Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		188,195	178,826
Portfolio Loans [Member] | Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		253,416	215,315
Portfolio Loans [Member] | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		1,197,152	1,170,618
Portfolio Loans [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		888,534	845,420
PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[1]	13,693	17,417
PCI Loans [Member] | Commercial and financial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		819	894
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		1,150	1,121
PCI Loans [Member] | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		9,855	9,776
PCI Loans [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		1,869	5,626
PULs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[1]	819,814	877,351
PULs [Member] | Commercial and financial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		79,562	92,690
PULs [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		7,593	10,610
PULs [Member] | Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		119,678	126,689
PULs [Member] | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		438,232	459,598
PULs [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		$ 174,749	$ 187,764
[1]	Net loan balances as of March 31, 2018 and December 31, 2017 include deferred costs of $13.9 million and $12.9 million for each period, respectively.

Loans - Contractual Aging of Re

Loans - Contractual Aging of Recorded Investment in Past Due Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 3,869,778	$ 3,788,998
Nonaccrual	19,339	19,524
Total Financing Receivables	3,897,125	3,817,377
Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	7,119	8,082
Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	660	773
Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	229	0
Portfolio Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	3,044,590	2,903,109
Nonaccrual	12,628	12,569
Total Financing Receivables	3,063,618	2,922,609
Portfolio Loans [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,194,839	1,165,738
Nonaccrual	1,017	1,690
Total Financing Receivables	1,197,152	1,170,618
Portfolio Loans [Member] | Commercial And Financials [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	530,801	507,501
Nonaccrual	1,969	2,127
Total Financing Receivables	536,321	512,430
Portfolio Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	187,818	178,676
Nonaccrual	85	98
Total Financing Receivables	188,195	178,826
Portfolio Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	5,842	6,245
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	1,296	2,605
Portfolio Loans [Member] | Accruing 30-59 Days Past Due | Commercial And Financials [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	3,149	2,776
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	218	52
Portfolio Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	329	686
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	0	585
Portfolio Loans [Member] | Accruing 60-89 Days Past Due | Commercial And Financials [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	173	26
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	74	0
Portfolio Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	229	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 | Commercial And Financials [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	229	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
Purchased Unimpaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	813,244	874,028
Nonaccrual	4,962	2,041
Total Financing Receivables	819,814	877,351
Purchased Unimpaired Loans [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	436,589	457,899
Nonaccrual	708	720
Total Financing Receivables	438,232	459,598
Purchased Unimpaired Loans [Member] | Commercial And Financials [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	79,400	92,315
Financing Receivable, Recorded Investment, Past Due	2
Nonaccrual	160	321
Total Financing Receivables	79,562	92,690
Purchased Unimpaired Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	7,588	10,610
Nonaccrual	0	0
Total Financing Receivables	7,593	10,610
Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,277	1,195
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	609	979
Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due | Commercial And Financials [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due		54
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	0
Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	331	87
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	326	0
Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due | Commercial And Financials [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 | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	5	0
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 | Commercial And Financials [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 Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	11,944	11,861
Nonaccrual	1,749	4,914
Total Financing Receivables	13,693	17,417
Purchased Credit Impaired Loans [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	9,427	9,352
Nonaccrual	428	424
Total Financing Receivables	9,855	9,776
Purchased Credit Impaired Loans [Member] | Commercial And Financials [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	819	844
Financing Receivable, Recorded Investment, Past Due	0
Nonaccrual	0	50
Total Financing Receivables	819	894
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] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	642
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 | Commercial And Financials [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due		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 60-89 Days Past Due
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 | 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 | Commercial And Financials [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 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 | Commercial And Financials [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
Construction and land development [Member] | Portfolio Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	253,189	215,077
Nonaccrual	227	238
Total Financing Receivables	253,416	215,315
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	119,539	126,655
Nonaccrual	0	0
Total Financing Receivables	119,678	126,689
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	139	34
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	1,150	1,121
Nonaccrual	0	0
Total Financing Receivables	1,150	1,121
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	1,065,152	1,038,810
Residential real estate [Member] | Portfolio Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	877,943	836,117
Nonaccrual	9,330	8,416
Total Financing Receivables	888,534	845,420
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	1,179	812
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	82	75
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	170,128	186,549
Nonaccrual	4,094	1,000
Total Financing Receivables	174,749	187,764
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	527	128
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	0	87
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	548	544
Nonaccrual	1,321	4,440
Total Financing Receivables	1,869	5,626
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	0	642
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	0
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	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 3,897,125	$ 3,817,377
Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	374,244	343,125
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,645,239	1,639,992
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,065,152	1,038,810
Commercial and Financial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	616,702	606,014
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	195,788	189,436
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,799,349	3,722,027
Pass [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	363,778	328,127
Pass [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,596,893	1,586,932
Pass [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,036,786	1,023,925
Pass [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	608,025	593,689
Pass [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	193,867	189,354
Special mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	44,737	47,545
Special mention [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	8,471	10,414
Special mention [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	29,421	29,273
Special mention [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,456	4,621
Special mention [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,056	3,237
Special mention [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,333	0
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	51,485	47,494
Substandard [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,995	4,584
Substandard [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	18,925	23,787
Substandard [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	25,910	10,203
Substandard [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,067	8,838
Substandard [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	588	82
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,554	311
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	0	61
Doubtful [Member] | Commercial and Financial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,554	250
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 (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Beginning balance	$ 3,699	$ 3,807
Additions	0	0
Deletions	(43)	0
Accretion	(443)	(365)
Reclassification from non-accretable difference	339	68
Ending balance	$ 3,552	$ 3,510

Loans - Modified Loans (Details

Loans - Modified Loans (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)Number	Mar. 31, 2017USD ($)Number
Number of Contracts | Number	0	1
Pre-Modification Outstanding Recorded Investment	$ 0	$ 52
Post-Modification Outstanding Recorded Investment	0	46
Specific Reserve Recorded	0	0
Valuation Allowance Recorded	$ 0	$ 6
Construction and land development [Member]
Number of Contracts | Number		1
Pre-Modification Outstanding Recorded Investment		$ 52
Post-Modification Outstanding Recorded Investment		46
Specific Reserve Recorded		0
Valuation Allowance Recorded		$ 6

Loans - Company's Recorded Inve

Loans - Company's Recorded Investments in Impaired Loans and the Related Valuation Allowances (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Recorded Investment
Total	$ 32,608	$ 30,291
Unpaid Principal Balance
Total	38,135	35,519
Related Valuation Allowance
Total	2,745	2,402
Construction and Land Development [Member]
Recorded Investment
Impaired Loans with No Related Allowance Recorded	213	223
Impaired Loans with an Allowance Recorded	238	251
Total	451	474
Unpaid Principal Balance
Impaired Loans with No Related Allowance Recorded	497	510
Impaired Loans with an Allowance Recorded	251	264
Total	748	774
Related Valuation Allowance
Impaired Loans with No Related Allowance Recorded	0	0
Impaired Loans with an Allowance Recorded	26	23
Total	26	23
Commercial Real Estate [Member]
Recorded Investment
Impaired Loans with No Related Allowance Recorded	2,777	3,475
Impaired Loans with an Allowance Recorded	4,749	4,780
Total	7,526	8,255
Unpaid Principal Balance
Impaired Loans with No Related Allowance Recorded	4,196	4,873
Impaired Loans with an Allowance Recorded	4,749	4,780
Total	8,945	9,653
Related Valuation Allowance
Impaired Loans with No Related Allowance Recorded	0	0
Impaired Loans with an Allowance Recorded	178	195
Total	178	195
Residential Real Estate [Member]
Recorded Investment
Impaired Loans with No Related Allowance Recorded	14,156	10,272
Impaired Loans with an Allowance Recorded	7,744	8,448
Total	21,900	18,720
Unpaid Principal Balance
Impaired Loans with No Related Allowance Recorded	19,042	15,063
Impaired Loans with an Allowance Recorded	7,932	8,651
Total	26,974	23,714
Related Valuation Allowance
Impaired Loans with No Related Allowance Recorded	0	0
Impaired Loans with an Allowance Recorded	1,094	1,091
Total	1,094	1,091
Commercial And Financial [Member]
Recorded Investment
Impaired Loans with No Related Allowance Recorded	166	19
Impaired Loans with an Allowance Recorded	2,197	2,436
Total	2,363	2,455
Unpaid Principal Balance
Impaired Loans with No Related Allowance Recorded	177	29
Impaired Loans with an Allowance Recorded	878	883
Total	1,055	912
Related Valuation Allowance
Impaired Loans with No Related Allowance Recorded	0	0
Impaired Loans with an Allowance Recorded	1,406	1,050
Total	1,406	1,050
Consumer [Member]
Recorded Investment
Impaired Loans with No Related Allowance Recorded	93	105
Impaired Loans with an Allowance Recorded	275	282
Total	368	387
Unpaid Principal Balance
Impaired Loans with No Related Allowance Recorded	134	180
Impaired Loans with an Allowance Recorded	279	286
Total	413	466
Related Valuation Allowance
Impaired Loans with No Related Allowance Recorded	0	0
Impaired Loans with an Allowance Recorded	41	43
Total	$ 41	$ 43

Allowance for Loan Losses - Add

Allowance for Loan Losses - Additional Information (Details) - Loans [Member] - Bank shares, Inc [Member] - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Modifications [Line Items]
Assets, Fair Value Adjustment	$ 17.4	$ 19.4
Fair value adjustment Percent	2.10%	2.20%

Allowance for Loan Losses - Act

Allowance for Loan Losses - Activity in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Allowance for Loan Losses:
Beginning Balance	$ 27,122	$ 23,400
Provision for Loan Losses	1,085	1,304
Charge-Offs	(505)	(502)
Recoveries	504	409
TDR Valuation Adjustments	(88)	(49)
Ending Balance	28,118	24,562
Construction and Land Development [Member]
Allowance for Loan Losses:
Beginning Balance	1,642	1,219
Provision for Loan Losses	411	66
Charge-Offs	0	0
Recoveries	5	69
TDR Valuation Adjustments	0	(2)
Ending Balance	2,058	1,352
Commercial Real Estate [Member]
Allowance for Loan Losses:
Beginning Balance	9,285	9,273
Provision for Loan Losses	(575)	495
Charge-Offs	0	0
Recoveries	147	107
TDR Valuation Adjustments	(15)	(14)
Ending Balance	8,842	9,861
Residential Real Estate [Member]
Allowance for Loan Losses:
Beginning Balance	7,131	7,483
Provision for Loan Losses	788	(393)
Charge-Offs	0	(122)
Recoveries	200	128
TDR Valuation Adjustments	(72)	(32)
Ending Balance	8,047	7,064
Commercial And Financial [Member]
Allowance for Loan Losses:
Beginning Balance	7,297	3,636
Provision for Loan Losses	270	1,073
Charge-Offs	(198)	(121)
Recoveries	24	47
TDR Valuation Adjustments	0	0
Ending Balance	7,393	4,635
Consumer [Member]
Allowance for Loan Losses:
Beginning Balance	1,767	1,789
Provision for Loan Losses	191	63
Charge-Offs	(307)	(259)
Recoveries	128	58
TDR Valuation Adjustments	(1)	(1)
Ending Balance	$ 1,778	$ 1,650

Allowance for Loan Losses - Loa

Allowance for Loan Losses - Loan Portfolio and Related Allowance (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Recorded Investment
Individually Evaluated for Impairment	$ 32,608	$ 30,291
Collectively Evaluated for Impairment	3,850,824	3,769,670
Total	3,883,432	3,799,961
Associated Allowance
Individually Evaluated for Impairment	2,745	2,402
Collectively Evaluated for Impairment	25,373	24,720
Total	28,118	27,122
PCI Loans [Member]
Recorded Investment
Individually Evaluated for Impairment	13,693
Collectively Evaluated for Impairment		0
Associated Allowance
Individually Evaluated for Impairment		17,417
Collectively Evaluated for Impairment	0
Construction and Land Development [Member]
Recorded Investment
Individually Evaluated for Impairment	451	474
Collectively Evaluated for Impairment	372,643	341,530
Total	373,094	342,004
Associated Allowance
Individually Evaluated for Impairment	26	23
Collectively Evaluated for Impairment	2,032	1,619
Total	2,058	1,642
Construction and Land Development [Member] | PCI Loans [Member]
Recorded Investment
Individually Evaluated for Impairment	1,150		$ 1,121
Associated Allowance
Individually Evaluated for Impairment	0		0
Commercial Real Estate [Member]
Recorded Investment
Individually Evaluated for Impairment	7,526	8,255
Collectively Evaluated for Impairment	1,627,858	1,621,960
Total	1,635,384	1,630,215
Associated Allowance
Individually Evaluated for Impairment	178	195
Collectively Evaluated for Impairment	8,664	9,090
Total	8,842	9,285
Commercial Real Estate [Member] | PCI Loans [Member]
Recorded Investment
Individually Evaluated for Impairment	9,855		9,776
Associated Allowance
Individually Evaluated for Impairment	0		0
Residential Real Estate [Member]
Recorded Investment
Individually Evaluated for Impairment	21,900	18,720
Collectively Evaluated for Impairment	1,041,383	1,014,465
Total	1,063,283	1,033,185
Associated Allowance
Individually Evaluated for Impairment	1,094	1,091
Collectively Evaluated for Impairment	6,953	6,040
Total	8,047	7,131
Residential Real Estate [Member] | PCI Loans [Member]
Recorded Investment
Individually Evaluated for Impairment	1,869		5,626
Associated Allowance
Individually Evaluated for Impairment	0		0
Commercial And Financial [Member]
Recorded Investment
Individually Evaluated for Impairment	2,363	2,455
Collectively Evaluated for Impairment	613,520	602,666
Total	615,883	605,121
Associated Allowance
Individually Evaluated for Impairment	1,406	1,050
Collectively Evaluated for Impairment	5,987	6,247
Total	7,393	7,297
Commercial And Financial [Member] | PCI Loans [Member]
Recorded Investment
Individually Evaluated for Impairment	819		894
Associated Allowance
Individually Evaluated for Impairment	0		0
Consumer [Member]
Recorded Investment
Individually Evaluated for Impairment	368	387
Collectively Evaluated for Impairment	195,420	189,049
Total	195,788	189,436
Associated Allowance
Individually Evaluated for Impairment	41	43
Collectively Evaluated for Impairment	1,737	1,724
Total	1,778	$ 1,767
Consumer [Member] | PCI Loans [Member]
Recorded Investment
Individually Evaluated for Impairment	0		0
Associated Allowance
Individually Evaluated for Impairment	$ 0		$ 0

Securities Sold Under Agreeme45

Securities Sold Under Agreements to Repurchase - Schedule Of Securities Financing Transactions (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Mortgage-backed securities of U.S. Government Sponsored Entities [Member]
Securities Financing Transaction [Line Items]
Securities Sold under Agreements to Repurchase, Fair Value of Collateral	$ 173,249	$ 216,094

Noninterest Income and Expens46

Noninterest Income and Expense - Summary of Noninterest Income and Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Noninterest income
Service charges on deposit accounts	$ 2,672	$ 2,422
Trust fees	1,021	880
Mortgage banking fees	1,402	1,552
Brokerage commissions and fees	359	377
Marine finance fees	573	134
Interchange income	2,942	2,494
BOLI income	1,056	733
Other income	2,373	1,313
Noninterest Income	12,398	9,905
Securities losses, net	(102)	0
TOTAL	12,296	9,905
Noninterest expense
Salaries and wages	15,381	15,369
Employee benefits	3,081	3,068
Outsourced data processing costs	3,679	3,269
Telephone/data lines	612	532
Occupancy	3,117	3,157
Furniture and equipment	1,457	1,391
Marketing	1,252	922
Legal and professional fees	1,973	2,132
FDIC assessments	598	570
Amortization of intangibles	989	719
Net losses (gains) and disposition expense on other real estate owned	192	(293)
Other	4,833	3,910
TOTAL	$ 37,164	$ 34,746

Equity Capital - Additional Inf

Equity Capital - Additional Information (Details)	Mar. 31, 2018
Class of Stock [Line Items]
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	6.50%

Fair Value - Additional Informa

Fair Value - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
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	7.60%
Loans and Leases Receivable, Allowance	$ 28,118	$ 27,122	$ 24,562	$ 23,400
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	200
Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure	7,100	4,200
Loans and Leases Receivable, Allowance	2,700	$ 2,400
Other Real Estate, Disposals	3,100
Other Real Estate, Improvements	$ 2,000

Fair Value - Fair Value Measure

Fair Value - Fair Value Measurements for Items Measured at Fair Value (Details) - USD ($) $ in Thousands		Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		$ 982,958	$ 949,460
Loans held for sale		20,887	24,306
Other real estate owned		10,288	7,640
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities		982,958	949,460	[1]
Loans held for sale	[2]	20,887	24,306
Equity securities	[3]	6,242	6,344
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 debt securities		100	100	[1]
Loans held for sale	[2]	0	0
Equity securities	[3]	6,242	6,344
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 debt securities		982,858	949,360	[1]
Loans held for sale	[2]	20,887	24,306
Equity securities	[3]	0	0
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 debt securities		0	0	[1]
Loans held for sale	[2]	0	0
Equity securities	[3]	0	0
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	[4]	7,139	4,192
Other real estate owned	[5]	10,288	7,640
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	[4]	0	0
Other real estate owned	[5]	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	[4]	6,607	3,454
Other real estate owned	[5]	3,826	60
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	[4]	532	738
Other real estate owned	[5]	$ 6,462	$ 7,580
[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]	Prior to adoption of ASU 2016-01 on January 1, 2018, an investment in shares of a mutual fund that invests primarily in CRA-qualified debt securities was classified as an available for sale security. Beginning in 2018, this security is reported at fair value in Other Assets. Fair value is determined based on market quotations.
[4]	See Note F. 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.
[5]	Fair value is measured on a nonrecurring basis in accordance with ASC 360.

Fair Value - fair value of cont

Fair Value - fair value of contractual balance and gains or losses (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Aggregate fair value	$ 20,887	$ 24,306
Contractual balance	20,303	23,627
Excess	$ 584	$ 679

Fair Value - Summary of Carryin

Fair Value - Summary of Carrying Value and Fair Value of Company's Financial Instruments (Details) - USD ($) $ in Thousands		Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities held to maturity (1)		$ 400,647	$ 416,863
Loans, net		3,869,007	3,790,255
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities held to maturity (1)	[1]	0	0
Time deposits with other banks		0	0
Loans, net		0	0
Deposit liabilities		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]
Debt securities held to maturity (1)	[1]	391,867	414,472
Time deposits with other banks		0	0
Loans, net		0	0
Deposit liabilities		0	0
Subordinated debt		61,591	61,530
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities held to maturity (1)	[1]	0	0
Time deposits with other banks		12,475	12,493
Loans, net		3,852,712	3,760,754
Deposit liabilities		4,713,262	4,588,515
Subordinated debt		0	0
Carrying Amount [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities held to maturity (1)	[1]	400,647	416,863
Time deposits with other banks		12,553	12,553
Loans, net		3,861,868	3,786,063
Deposit liabilities		4,719,543	4,592,720
Subordinated debt		$ 70,591	$ 70,521
[1]	See Note D for further detail of recurring fair value basis of individual investment categories.

Business Combinations - Additio

Business Combinations - Additional Information (Details) - USD ($) $ in Millions	Nov. 03, 2017	Apr. 07, 2017	Oct. 20, 2017	Mar. 31, 2018
Gulf Shore Banc shares Inc [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets		$ 358
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Liabilities Deposits		285
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Noncurrent Assets Loans		$ 251
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 Seacoasts closing price of $23.94 per share on April 7, 2017).
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount		$ 37.1
Palm Beach Community Bank [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	$ 357
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Liabilities Deposits	269
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Noncurrent Assets Loans	$ 270
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%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount	$ 34.8
NorthStar Bank [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets			$ 216
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Liabilities Deposits			182
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Noncurrent Assets Loans			$ 137
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			$ 12.3

Business Combinations - Purchas

Business Combinations - Purchase Price (Details) $ / shares in Units, $ in Thousands	Nov. 03, 2017USD ($)$ / sharesshares	Apr. 07, 2017USD ($)$ / sharesshares	Oct. 20, 2017USD ($)$ / sharesshares	Mar. 31, 2018shares	Dec. 31, 2017shares
Business Acquisition [Line Items]
Number of NorthStar Banking Corporation common shares outstanding | shares				46,983,165	46,917,735
Gulf Shore Banc shares Inc [Member]
Business Acquisition [Line Items]
Shares exchanged for cash		$ 8,034
Number of GulfShore Bancshares, Inc. common shares outstanding | shares		5,464
Total purchase price		$ 70,917
Per share exchange ratio		0.4807
Number of shares of Seacoast common stock issued | shares		2,627
Multiplied by common stock price per share | $ / shares		$ 23.94
Value of common stock issued		$ 62,883
Number of Palm Beach Community Bank Common shares outstanding | shares		5,464
NorthStar Bank [Member]
Business Acquisition [Line Items]
Shares exchanged for cash			$ 4,701
Number of NorthStar Banking Corporation common shares outstanding | shares			1,958
Total purchase price			$ 32,855
Cash paid for NorthStar Banking vested Corporation stock options			$ 801
Per share exchange ratio			0.5605
Number of shares of Seacoast common stock issued | shares			1,098
Multiplied by common stock price per share | $ / shares			$ 24.92
Value of common stock issued			$ 27,353
Palm Beach Community Bank [Member]
Business Acquisition [Line Items]
Shares exchanged for cash	$ 15,694
Number of GulfShore Bancshares, Inc. common shares outstanding | shares	2,507
Total purchase price	$ 72,006
Per share exchange ratio	0.9240
Number of shares of Seacoast common stock issued | shares	2,316
Multiplied by common stock price per share | $ / shares	$ 24.31
Value of common stock issued	$ 56,312
Number of Palm Beach Community Bank Common shares outstanding | shares	2,507

Business Combinations - fair va

Business Combinations - fair value of the assets purchased, including goodwill, and liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Nov. 03, 2017	Oct. 20, 2017	Apr. 07, 2017
Assets:
Goodwill	$ 148,555	$ 147,578
Bank shares, Inc [Member] | Measurement Period Adjustments [Member]
Assets:
Cash				$ 0
Investment securities				0
Loans, net				0
Fixed assets				0
Core deposit intangibles				0
Goodwill				(99)
Other assets				99
Total assets acquired				0
Liabilities:
Deposits				0
Other liabilities				0
Total liabilities assumed				0
Bank shares, Inc [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
Bank shares, Inc [Member] | Restatement Adjustment [Member]
Assets:
Cash				5,485
Investment securities				56,123
Loans, net				136,832
Fixed assets				2,637
Core deposit intangibles				1,275
Goodwill				12,305
Other assets				1,621
Total assets acquired				216,278
Liabilities:
Deposits				182,443
Other liabilities				980
Total liabilities assumed				$ 183,423
Gulf Shore Banc shares Inc [Member]
Assets:
Other assets					$ 358,000
Gulf Shore Banc shares Inc [Member] | Measurement Period Adjustments [Member]
Assets:
Cash					0
Investment securities					0
Loans, net					0
Fixed assets					0
Other real estate owned					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					55,540
Investment securities					316
Loans, net					250,876
Fixed assets					1,307
Other real estate owned					13
Core deposit intangibles					3,927
Goodwill					37,098
Other assets					8,572
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					55,540
Investment securities					316
Loans, net					250,876
Fixed assets					1,307
Other real estate owned					13
Core deposit intangibles					3,927
Goodwill					37,098
Other assets					8,572
Total assets acquired					357,649
Liabilities:
Deposits					285,350
Other liabilities					1,382
Total liabilities assumed					$ 286,732
Palm Beach Community Bank [Member]
Assets:
Other assets			$ 357,000
Palm Beach Community Bank [Member] | Measurement Period Adjustments [Member]
Assets:
Cash			0
Investment securities			0
Loans, net			(1,772)
Fixed assets			0
Core deposit intangibles			0
Goodwill			1,323
Other assets			449
Total assets acquired			0
Liabilities:
Deposits			0
Other liabilities			0
Total liabilities assumed			0
Palm Beach Community Bank [Member] | Scenario, Previously Reported [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
Palm Beach Community Bank [Member] | Restatement Adjustment [Member]
Assets:
Cash			9,301
Investment securities			22,098
Loans, net			270,318
Fixed assets			7,641
Core deposit intangibles			2,523
Goodwill			34,751
Other assets			10,358
Total assets acquired			356,990
Liabilities:
Deposits			268,633
Other liabilities			16,351
Total liabilities assumed			$ 284,984

Business Combinations - fair 55

Business Combinations - fair value of acquired loans (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Nov. 03, 2017	Oct. 20, 2017	Apr. 07, 2017	Mar. 31, 2017	Dec. 31, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	$ 3,552	$ 3,699				$ 3,510	$ 3,807
Gulf Shore Banc shares Inc [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net					$ 256,876
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value					250,876
Gulf Shore Banc shares Inc [Member] | 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
Gulf Shore Banc shares Inc [Member] | 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
Gulf Shore Banc shares Inc [Member] | 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
Gulf Shore Banc shares Inc [Member] | 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
Gulf Shore Banc shares Inc [Member] | 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
Gulf Shore Banc shares Inc [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			270,318
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			132,089
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			35,876
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

Business Combinations - purch56

Business Combinations - purchased credit impaired loans (Details) - USD ($) $ in Thousands	Nov. 03, 2017	Oct. 20, 2017
Palm Beach Community Bank [Member]
Total purchased credit-impaired loan acquired	$ 270,318
Palm Beach Community Bank [Member] | Purchased Credit Impaired [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]
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) - Palm Beach Community Bank [Member] $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)$ / shares
Business Acquisition [Line Items]
Net interest income | $	$ 45,987
Net income | $	$ 11,285
EPS - basic | $ / shares	$ 0.25
EPS - diluted | $ / shares	$ 0.25