Atlantic Capital Bancshares (ACBI) 10-Q 8 Nov 18 2018 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 31, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	ATLANTIC CAPITAL BANCSHARES, INC.
Entity Central Index Key	1,461,755
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		26,107,896

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
ASSETS
Cash and due from banks	$ 28,007	$ 38,086
Interest-bearing deposits in banks	140,682	281,247
Other short-term investments	20,898	10,681
Cash and cash equivalents	189,587	330,014
Securities available-for-sale	465,756	449,117
Other investments	33,021	32,174
Loans held for sale	1,886	1,487
Loans held for investment	2,038,434	1,933,839
Less: Allowance for loan losses	(20,443)	(19,344)
Loans held for investment, net	2,017,991	1,914,495
Premises and equipment, net	17,371	12,054
Bank owned life insurance	64,769	63,667
Goodwill and intangible assets, net	26,557	27,633
Other real estate owned	968	1,215
Other assets	64,815	59,565
Total assets	2,882,721	2,891,421
Deposits:
Noninterest-bearing demand	653,816	732,442
Interest-bearing checking	486,456	306,331
Savings	27,192	26,573
Money market	977,552	1,117,891
Time	155,689	138,612
Brokered deposits	79,119	128,816
Total deposits	2,379,824	2,450,665
Federal funds purchased and securities sold under agreements to repurchase	8,904	0
Federal Home Loan Bank borrowings	83,000	45,000
Long-term debt	49,662	49,535
Other liabilities	41,094	37,796
Total liabilities	2,562,484	2,582,996
SHAREHOLDERS’ EQUITY
Preferred Stock, no par value – 10,000,000 shares authorized; no shares issued and outstanding as of September 30, 2018 and December 31, 2017	0	0
Common stock, no par value – 100,000,000 shares authorized; 26,103,666 and 25,712,909 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively	305,300	299,474
Retained earnings	33,357	12,810
Accumulated other comprehensive (loss) income	(18,420)	(3,859)
Total shareholders’ equity	320,237	308,425
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 2,882,721	$ 2,891,421

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - shares	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Common stock authorized (in shares)	100,000,000	100,000,000
Common stock issued (in shares)	26,103,666	25,712,909
Common stock outstanding (in shares)	26,103,666	25,712,909
Preferred stock authorized (in shares)	10,000,000	10,000,000
Preferred stock issued (in shares)	0	0
Preferred stock outstanding (in shares)	0	0

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
INTEREST INCOME
Loans, including fees	$ 24,619	$ 21,491	$ 71,073	$ 62,846
Investment securities available-for-sale	2,789	2,298	8,068	6,671
Interest and dividends on other interest-earning assets	1,111	562	2,706	1,617
Total interest income	28,519	24,351	81,847	71,134
INTEREST EXPENSE
Interest on deposits	4,403	2,693	11,098	7,221
Interest on Federal Home Loan Bank advances	637	459	1,912	1,213
Interest on federal funds purchased and securities sold under agreements to repurchase	92	84	267	196
Interest on long-term debt	824	824	2,476	2,471
Total interest expense	5,956	4,060	15,753	11,101
NET INTEREST INCOME BEFORE PROVISION FOR LOAN LOSSES	22,563	20,291	66,094	60,033
Provision for loan losses	845	322	1,444	2,936
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	21,718	19,969	64,650	57,097
NONINTEREST INCOME
Service charges	1,278	1,247	3,778	3,870
(Loss) gain on sales of securities available-for-sale	0	(80)	(2)	(80)
Gain (loss) on sales of other assets	58	44	(154)	788
Mortgage income	315	320	982	965
Trust income	0	437	1,025	1,332
Derivatives income	20	(3)	154	62
Bank owned life insurance	379	384	1,126	1,146
SBA lending activities	882	888	3,181	3,286
Gains on sale of branches	0	0	0	302
Gain on sale of trust business	0	0	1,681	0
Other noninterest income	134	240	609	950
Total noninterest income	3,066	3,477	12,380	12,621
NONINTEREST EXPENSE
Salaries and employee benefits	10,152	10,409	33,150	32,077
Occupancy	1,288	1,129	3,854	3,433
Equipment and software	964	776	2,655	2,577
Professional services	803	1,595	2,595	3,472
Postage, printing and supplies	75	63	194	226
Communications and data processing	947	982	2,993	3,038
Marketing and business development	281	272	662	721
FDIC premiums	208	308	552	754
Merger and conversion costs	0	0	0	304
Amortization of intangibles	296	391	958	1,286
Foreclosed property/problem asset expense	12	7	296	117
Other noninterest expense	1,569	1,572	4,439	4,866
Total noninterest expense	16,595	17,504	52,348	52,871
INCOME BEFORE PROVISION FOR INCOME TAXES	8,189	5,942	24,682	16,847
Provision for income taxes	1,676	1,890	4,980	5,236
NET INCOME	$ 6,513	$ 4,052	$ 19,702	$ 11,611
NET INCOME PER SHARE:
Net income per share – basic (in dollars per share)	$ 0.25	$ 0.16	$ 0.76	$ 0.45
Net income per share – diluted (in dollars per share)	$ 0.25	$ 0.16	$ 0.75	$ 0.45

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 6,513	$ 4,052	$ 19,702	$ 11,611
Unrealized gains (losses) on available-for-sale securities:
Unrealized holding gains (losses) arising during the period, net of tax of ($1,041), $272, ($3,775), and $2,450, respectively	(3,119)	434	(11,322)	3,916
Reclassification adjustment for losses (gains) included in net income net of tax of $0, $31, $1, and $31, respectively	0	49	1	49
Unrealized gains (losses) on available-for-sale securities, net of tax	(3,119)	483	(11,321)	3,965
Cash flow hedges:
Net unrealized derivative gains (losses) on cash flow hedges, net of tax of ($145), ($46), ($799), and ($125), respectively	(434)	(75)	(2,396)	(202)
Changes from cash flow hedges	(434)	(75)	(2,396)	(202)
Other comprehensive income (loss), net of tax	(3,553)	408	(13,717)	3,763
Comprehensive income	$ 2,960	$ 4,460	$ 5,985	$ 15,374

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Tax portion of unrealized holding gains arising during the period	$ (597)	$ 1,951	$ (2,734)	$ 2,178
Tax portion of reclassification adjustments for losses (gains) included in net income	1	0	1	0
Tax portion of net unrealized derivative (losses) gains on cash flow hedges	$ (184)	$ 12	$ (654)	$ (79)

Consolidated Statements of Shar

Consolidated Statements of Shareholders’ Equity - USD ($)	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2016		25,093,135
Accumulated other comprehensive income (loss) beginning of period at Dec. 31, 2016	$ 303,658,000	$ 292,747,000	$ 16,536,000	$ (5,625,000)
Comprehensive income:
Net income	11,611,000		11,611,000
Change in unrealized gains (losses) on investment securities available-for-sale, net	3,965,000			3,965,000
Change in unrealized gains (losses) on cash flow hedges	(202,000)			(202,000)
Comprehensive income	15,374,000
Net forfeitures of restricted stock (in shares)		101,791
Issuance of common stock for option exercises (in shares)		459,693
Issuance of common stock for option exercises	3,172,000	$ 3,172,000
Issuance of common stock for long-term incentive plan (in shares)		61,799
Issuance of common stock for long-term incentive plan	1,209,000	$ 1,209,000
Restricted stock activity	869,000	869,000
Stock option compensation	472,000	$ 472,000
Ending balance (in shares) at Sep. 30, 2017		25,716,418
Accumulated other comprehensive income (loss) end of period at Sep. 30, 2017	324,754,000	$ 298,469,000	28,147,000	(1,862,000)
Accumulated other comprehensive income (loss) beginning of period at Jun. 30, 2017				(2,270,000)
Comprehensive income:
Net income	4,052,000
Change in unrealized gains (losses) on investment securities available-for-sale, net	483,000
Change in unrealized gains (losses) on cash flow hedges	(75,000)
Comprehensive income	4,460,000
Ending balance (in shares) at Sep. 30, 2017		25,716,418
Accumulated other comprehensive income (loss) end of period at Sep. 30, 2017	$ 324,754,000	$ 298,469,000	28,147,000	(1,862,000)
Beginning balance (in shares) at Dec. 31, 2017	25,712,909	25,712,909
Accumulated other comprehensive income (loss) beginning of period at Dec. 31, 2017	$ 308,425,000	$ 299,474,000	12,810,000	(3,859,000)
Comprehensive income:
Reclassification of tax effects from AOCI	$ 0
Beginning balance (in shares) at Dec. 31, 2017	25,712,909	25,712,909
Accumulated other comprehensive income (loss) beginning of period at Dec. 31, 2017	$ 308,425,000	$ 299,474,000	12,810,000	(3,859,000)
Comprehensive income:
Net income	19,702,000		19,702,000
Reclassification of tax effects from AOCI	0		844,000	(844,000)
Change in unrealized gains (losses) on investment securities available-for-sale, net	(11,321,000)			(11,321,000)
Change in unrealized gains (losses) on cash flow hedges	(2,396,000)			(2,396,000)
Comprehensive income	$ 5,985,000
Net forfeitures of restricted stock (in shares)	0	66,686
Issuance of common stock for option exercises (in shares)	300,616	285,230
Issuance of common stock for option exercises	$ 4,003,000	$ 4,003,000
Issuance of common stock for long-term incentive plan (in shares)		38,841
Issuance of common stock for long-term incentive plan	687,000	$ 687,000
Restricted stock activity	832,000	832,000
Stock option compensation	168,000	168,000
Performance share compensation	$ 136,000	$ 136,000
Ending balance (in shares) at Sep. 30, 2018	26,103,666	26,103,666
Accumulated other comprehensive income (loss) end of period at Sep. 30, 2018	$ 320,237,000	$ 305,300,000	33,357,000	(18,420,000)
Comprehensive income:
Change in accounting principle - Revenue Recognition | Accounting Standards Update 2014-09	1,000		1,000
Accumulated other comprehensive income (loss) beginning of period at Jun. 30, 2018				(14,867,000)
Comprehensive income:
Net income	6,513,000
Reclassification of tax effects from AOCI				0
Change in unrealized gains (losses) on investment securities available-for-sale, net	(3,119,000)
Change in unrealized gains (losses) on cash flow hedges	(434,000)
Comprehensive income	$ 2,960,000
Ending balance (in shares) at Sep. 30, 2018	26,103,666	26,103,666
Accumulated other comprehensive income (loss) end of period at Sep. 30, 2018	$ 320,237,000	$ 305,300,000	$ 33,357,000	$ (18,420,000)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
OPERATING ACTIVITIES
Net income	$ 19,702	$ 11,611
Adjustments to reconcile net income to net cash provided by operating activities
Provision for loan losses	1,444	2,936
Depreciation, amortization, and accretion	3,508	4,088
Amortization of restricted stock and performance share compensation	968	869
Stock option compensation	168	472
Loss (gain) on sales of available-for-sale securities	2	80
Loss on disposition of premises and equipment, net	214	347
Net write downs and losses (gains) on sales of other real estate owned	222	(267)
Small Business Investment Company (SBIC) impairment	228	0
Gain on sale of tax credit	0	(426)
Net increase in cash value of bank owned life insurance	(1,102)	(1,124)
Net gains on sale of branches	0	(302)
Net gain on sale of trust business	(1,681)	0
Origination of servicing assets	(739)	(749)
Proceeds from sales of SBA loans	46,924	34,448
Net gains on sale of SBA loans	(2,578)	(2,367)
Changes in operating assets and liabilities -
Net change in loans held for sale	(399)	7,587
Net (increase) decrease in other assets	581	(4,115)
Net decrease in accrued expenses and other liabilities	3,893	9,454
Net cash provided by operating activities	71,355	62,542
Activity in securities available-for-sale:
Prepayments	37,854	35,271
Maturities and calls	215	5,190
Sales	24	1,813
Purchases	(71,942)	(139,465)
Net change in loans held for investment	(149,347)	38,720
(Purchases) proceeds of Federal Home Loan Bank stock, net	(1,762)	(721)
(Purchases) proceeds of Federal Reserve Bank stock, net	(50)	(91)
Proceeds from sales of other real estate	402	1,081
Net cash received (paid) for branch divestiture	0	5,379
(Purchases) of premises and equipment, net	(7,242)	(1,353)
Net cash (used in) investing activities	(191,848)	(54,176)
FINANCING ACTIVITIES
Net change in deposits	(70,841)	(111,371)
Net change in short-term borrowings	8,904	0
Proceeds from Federal Home Loan Bank advances	1,203,100	1,404,000
Repayments of Federal Home Loan Bank advances	(1,165,100)	(1,389,000)
Proceeds from exercise of stock options	4,003	3,531
Net cash (used in) financing activities	(19,934)	(92,840)
NET CHANGE IN CASH AND CASH EQUIVALENTS	(140,427)	(84,474)
CASH AND CASH EQUIVALENTS – beginning of period	330,014	165,725
CASH AND CASH EQUIVALENTS – end of period	189,587	81,251
SUPPLEMENTAL SCHEDULE OF CASH FLOWS
Interest paid	14,817	12,270
Income taxes paid	$ 155	$ 840

Accounting Policies and Basis o

Accounting Policies and Basis of Presentation	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Accounting Policies and Basis of Presentation	ACCOUNTING POLICIES AND BASIS OF PRESENTATION Basis of Presentation The accounting and financial reporting policies of Atlantic Capital Bancshares, Inc. (“Atlantic Capital” or the “Company”) and its subsidiary, Atlantic Capital Bank, N.A. (the “Bank”), conform to accounting principles generally accepted in the United States of America (“GAAP”) and general banking industry practices. The accompanying interim consolidated financial statements have not been audited. All material intercompany balances and transactions have been eliminated. In management’s opinion, all accounting adjustments necessary to accurately reflect the financial position and results of operations on the accompanying financial statements have been made. These adjustments are normal and recurring accruals considered necessary for a fair and accurate presentation. The accompanying consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in Atlantic Capital’s filing on Form 10-K. The results for interim periods are not necessarily indicative of results for the full year or any other interim periods. Certain prior period amounts have been reclassified to conform to the current year presentation.

Accounting Standards Updates an

Accounting Standards Updates and Recently Adopted Standards	9 Months Ended
	Sep. 30, 2018
Accounting Changes and Error Corrections [Abstract]
Accounting Standards Updates and Recently Adopted Standards	ACCOUNTING STANDARDS UPDATES AND RECENTLY ADOPTED STANDARDS Recently Adopted Accounting Pronouncements In February 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-02, “Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” The guidance gives entities the option to reclassify into retained earnings tax effects related to items in accumulated other comprehensive income (“OCI”) that were stranded in accumulated OCI as a result of tax reform. It is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption in any period is permitted and Atlantic Capital adopted ASU 2018-02 as of January 1, 2018. The adoption of this update resulted in a reclassification of approximately $844,000 between accumulated OCI and retained earnings, and a net impact of zero to total shareholders’ equity. In August 2017, the FASB issued ASU 2017-12, “Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities.” The purpose of this updated guidance is to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. ASU 2017-12 is effective for public business entities for fiscal years beginning after December 15, 2018, with early adoption, including adoption in an interim period, permitted. Atlantic Capital adopted ASU 2017-12 as of January 1, 2018. The guidance requires a modified retrospective transition method resulting in the cumulative effect of the change on the opening balance of each affected component of equity in the statement of financial position as of the date of adoption. Adoption did not have a material impact on Atlantic Capital’s consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, “Compensation - Stock Compensation (Topic 718): Scope and Modification Accounting.” The amendments in this ASU provide guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in accordance with Topic 718. The amendments were effective for interim and annual reporting periods beginning after December 15, 2017. This ASU did not have a material impact on Atlantic Capital’s consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” to address diversity in how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The amendments provide guidance on the following eight specific cash flow issues: 1) debt prepayment or debt extinguishment costs; 2) settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; 3) contingent consideration payments made after a business combination; 4) proceeds from the settlement of insurance claims; 5) proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies; 6) distributions received from equity method investees; 7) beneficial interests in securitization transactions; and 8) separately identifiable cash flows and application of the predominance principle. The amendments were effective for public companies for fiscal years beginning after December 31, 2017, and interim periods within those fiscal years. This ASU did not have a material impact on the Company’s consolidated financial statements. In January 2016, the FASB issued ASU 2016-1, “Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Liabilities.” The guidance in this update requires that equity investments (except those accounted for under the equity method of accounting) be measured at fair value with changes in fair value recognized in net income. However, an entity may choose to measure equity investments that do not have readily determinable fair values at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. The guidance also simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment. In addition, the guidance requires that public business entities base their fair value disclosures for financial instruments that are not measured at fair value in the financial statements on the exit price notion. For public entities, this update was effective for fiscal years beginning after December 15, 2017. The adoption of this update did not have a material impact on Atlantic Capital’s consolidated financial statements, however Atlantic Capital changed the disclosure of financial instruments not measured at fair value to reflect the exit price notion. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers.” The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. For public companies, this guidance was effective for annual and interim periods beginning after December 15, 2017. Atlantic Capital completed its review of the impact of ASU 2014-09 on components of non-interest income and did not find any significant changes to its methodology of recognizing revenue. Revenue streams impacted by the ASU included service charges, trust income, sales of financed other real estate, and check printing revenue. The Company recorded a cumulative effect adjustment to first quarter 2018 opening retained earnings in an amount less than $2,000 , and included newly applicable revenue disclosures. Recently Issued Accounting Pronouncements Not Yet Adopted In August 2018, the FASB issued ASU No. 2018-13, “ Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement.” The amendments in this update modify the disclosure requirements for fair value measurements by removing, modifying, or adding certain disclosures. The update is effective for interim and annual periods in fiscal years beginning after December 31, 2019, with early adoption permitted for the removed disclosures and delayed adoption until fiscal year 2020 permitted for new disclosures. The removed and modified disclosures will be adopted on a retrospective basis and the new disclosures will be adopted on a prospective basis. The adoption will not have a material effect on the Company’s consolidated financial statements. In March 2017, the FASB issued ASU 2017-08, “Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities.” This guidance shortens the premium amortization period for certain callable debt securities by requiring amortization to the earliest call date. The standard is effective for public companies for annual and interim periods beginning after December 15, 2020. The adoption of this update is not expected to have a material impact on Atlantic Capital’s consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment,” which intends to simplify goodwill impairment testing by eliminating the second step of the analysis under which the implied fair value of goodwill is determined as if the reporting unit were being acquired in a business combination. The update instead requires entities to compare the fair value of a reporting unit with its carrying amount and recognize an impairment charge for any amount by which the carrying amount exceeds the reporting unit’s fair value, to the extent that the loss recognized does not exceed the amount of goodwill allocated to that reporting unit. ASU 2017-04 must be applied prospectively and is effective for the Company on January 1, 2020. Early adoption is permitted. Atlantic Capital does not expect the new guidance to have a material impact on its financial condition or results of operations. In June 2016, the FASB issued ASU 2016-13, “Financial Instruments - Credit Losses (Topic 326) Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires an entity to utilize a new impairment model known as the current expected credit loss (“CECL”) model to estimate its lifetime “expected credit loss” and record an allowance that, when deducted from the amortized cost basis of the financial asset, presents the net amount expected to be collected on the financial asset. The CECL model is expected to result in more timely recognition of credit losses. ASU 2016-13 also requires new disclosures for financial assets measured at amortized cost, loans and available-for-sale debt securities. ASU 2016-13 is effective for public companies for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. Entities will apply the standard’s provisions as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The Company has established a CECL working group with the expertise needed to implement the guidance. Members of the working group have developed a project task plan and timeline and are also attending conferences and meetings with audit firms, bank regulators and other banks to keep current on evolving interpretations of the guidance. The Company is implementing a software package supported by a third-party vendor to automate the calculation of the allowance for loan losses under the new methodology. Atlantic Capital is in the process of evaluating the impact of the adoption of ASU 2016-13 on the Company’s consolidated financial statements and disclosures. In February 2016, the FASB issued ASU 2016-2, “Leases.” Under the new guidance, leases classified as operating leases under previous GAAP must be recorded on the balance sheet. A lessee should recognize in the statement of financial position a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The standard is effective for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted. The new standard must be adopted using a modified retrospective transition, and provides for certain practical expedients. Upon adoption, Atlantic Capital expects to report higher assets and liabilities as a result of including leases on the consolidated balance sheet. The Company does not expect the new guidance to have a material impact on the consolidated statement of income or the consolidated statement of shareholders’ equity.

Acquisitions and Divestitures

Acquisitions and Divestitures	9 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Acquisitions and Divestitures	ACQUISITIONS AND DIVESTITURES Sale of Southeastern Trust Company (“SETCO”) On December 14, 2017, the Bank entered into an agreement with The Banc Group, LLC to sell its trust business, a division of the Bank known as Southeastern Trust Company (“SETCO”), for approximately $1.7 million . The Banc Group, LLC, which subsequently changed its name to Southeastern Trust Company, LLC, is controlled by a former director and Chief Operating Officer of the Company. The sale of SETCO closed on June 1, 2018 and Atlantic Capital recorded a gain of $1.7 million during the second quarter, which was net of goodwill impairment in the amount of $69,000 .

Balance Sheet Offsetting

Balance Sheet Offsetting	9 Months Ended
	Sep. 30, 2018
Offsetting [Abstract]
Balance Sheet Offsetting	BALANCE SHEET OFFSETTING Atlantic Capital enters into reverse repurchase agreements in order to invest short-term funds. Atlantic Capital enters into repurchase agreements for short-term financing needs. The following table presents a summary of amounts outstanding under reverse repurchase agreements, repurchase agreements, and derivative financial instruments including those entered into in connection with the same counterparty under master netting agreements as of September 30, 2018 and December 31, 2017 . While these agreements are typically over-collateralized, U.S. GAAP requires disclosures in this table to limit the amount of such collateral to the amount of the related recognized asset or liability for each counterparty. (in thousands) Gross Amounts not Offset in the Balance Sheet September 30, 2018 Gross Amounts of Recognized Assets Gross Amounts Offset on the Balance Sheet Net Asset Balance Financial Instruments Cash Collateral Received Net Amount Reverse repurchase agreements $ 20,898 $ — $ 20,898 $ (20,898 ) $ — $ — Derivatives 4,572 — 4,572 — — 4,572 Total $ 25,470 $ — $ 25,470 $ (20,898 ) $ — $ 4,572 Gross Amounts not Offset in the Balance Sheet Gross Amounts of Recognized Liabilities Gross Amounts Offset on the Balance Sheet Net Liability Balance Financial Instruments Cash Collateral Pledged Net Amount Repurchase agreements $ 8,904 $ — $ 8,904 $ (10,828 ) $ — $ — Derivatives 8,552 — 8,552 (7,226 ) (1,326 ) — Total $ 17,456 $ — $ 17,456 $ (18,054 ) $ (1,326 ) $ — Gross Amounts not Offset in the Balance Sheet December 31, 2017 Gross Amounts of Recognized Assets Gross Amounts Offset on the Balance Sheet Net Asset Balance Financial Instruments Cash Collateral Received Net Amount Reverse repurchase agreements $ 10,681 $ — $ 10,681 $ (10,681 ) $ — $ — Derivatives 3,018 — 3,018 — — 3,018 Total $ 13,699 $ — $ 13,699 $ (10,681 ) $ — $ 3,018 Gross Amounts not Offset in the Balance Sheet Gross Amounts of Recognized Liabilities Gross Amounts Offset on the Balance Sheet Net Liability Balance Financial Instruments Cash Collateral Pledged Net Amount Repurchase agreements $ — $ — $ — $ — $ — $ — Derivatives 4,023 — 4,023 (2,705 ) (1,318 ) — Total $ 4,023 $ — $ 4,023 $ (2,705 ) $ (1,318 ) $ —

Securities

Securities	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Securities	SECURITIES The following table presents the amortized cost, unrealized gains and losses, and fair value of securities available-for-sale at September 30, 2018 and December 31, 2017 . Available-For-Sale Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) September 30, 2018 Debt securities— U.S. Government agencies $ 36,708 $ — $ (1,263 ) $ 35,445 U.S. states and political divisions 91,656 2 (8,993 ) 82,665 Trust preferred securities 4,774 — (149 ) 4,625 Corporate debt securities 12,879 — (510 ) 12,369 Residential mortgage-backed securities 340,417 2,427 (12,192 ) 330,652 Total $ 486,434 $ 2,429 $ (23,107 ) $ 465,756 December 31, 2017 Debt securities— U.S. Government agencies $ 34,699 $ 11 $ (599 ) $ 34,111 U.S. states and political divisions 92,169 237 (2,405 ) 90,001 Trust preferred securities 4,754 — (104 ) 4,650 Corporate debt securities 12,948 60 (386 ) 12,622 Residential mortgage-backed securities 310,129 2,423 (4,819 ) 307,733 Total $ 454,699 $ 2,731 $ (8,313 ) $ 449,117 The following table presents the amortized cost and fair value of debt securities by contractual maturity at September 30, 2018 . Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Available-For-Sale Amortized Cost Fair Value (in thousands) Within 1 year $ 246 $ 245 Over 1 year through 5 years 30,299 29,151 5 years to 10 years 47,062 45,326 Over 10 years 68,410 60,382 146,017 135,104 Residential mortgage-backed securities 340,417 330,652 Total $ 486,434 $ 465,756 The following table summarizes available-for-sale securities in an unrealized loss position as of September 30, 2018 and December 31, 2017 . Less than 12 months 12 months or greater Totals Available-For-Sale Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands) September 30, 2018 U.S. Government agencies $ 11,983 $ (310 ) $ 23,462 $ (952 ) $ 35,445 $ (1,262 ) U.S. states and political divisions 22,182 (1,301 ) 59,978 (7,693 ) 82,160 (8,994 ) Trust preferred securities 4,625 (149 ) — — 4,625 (149 ) Corporate debt securities 7,446 (141 ) 4,922 (369 ) 12,368 (510 ) Residential mortgage-backed securities 133,239 (3,224 ) 184,247 (8,968 ) 317,486 (12,192 ) Totals $ 179,475 $ (5,125 ) $ 272,609 $ (17,982 ) $ 452,084 $ (23,107 ) December 31, 2017 U.S. Government agencies $ 22,148 $ (348 ) $ 9,145 $ (251 ) $ 31,293 $ (599 ) U.S. states and political divisions 14,009 (183 ) 58,744 (2,222 ) 72,753 (2,405 ) Trust preferred securities — — 4,650 (104 ) 4,650 (104 ) Corporate debt securities 2,989 (27 ) 2,970 (359 ) 5,959 (386 ) Residential mortgage-backed securities 155,637 (1,344 ) 126,580 (3,475 ) 282,217 (4,819 ) Totals $ 194,783 $ (1,902 ) $ 202,089 $ (6,411 ) $ 396,872 $ (8,313 ) At September 30, 2018 , there were 337 available-for-sale securities that were in an unrealized loss position. Atlantic Capital does not intend to sell and does not believe it will be required to sell securities in an unrealized loss position prior to the recovery of their amortized cost basis. Unrealized losses at September 30, 2018 and December 31, 2017 were attributable to changes in interest rates. Management evaluates securities for other-than-temporary impairment on a quarterly basis. Consideration is given to the length of time and the extent to which the fair value has been less than cost, the financial condition and near-term prospects of the issuer, among other factors. In analyzing an issuer’s financial condition, management considers whether the securities are issued by the federal government or its agencies, whether downgrades by bond rating agencies have occurred, and internal and external analyst reviews. No impairment charges on securities available-for-sale were recognized during the three or nine months ended September 30, 2018 or 2017 . Realized gains and losses are derived using the specific identification method for determining the cost of securities sold. The following table summarizes securities sales activity for the three and nine months ended September 30, 2018 and 2017 . Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) Proceeds from sales $ — $ 1,813 $ 24 $ 1,813 Gross realized gains — — — — Gross realized losses — (80 ) (2 ) (80 ) Net losses on sales of securities $ — $ (80 ) $ (2 ) $ (80 ) Investment securities with a carrying value of $70.6 million and $93.9 million were pledged to secure public funds and other borrowings at September 30, 2018 and December 31, 2017 , respectively. As of September 30, 2018, Atlantic Capital had investments with a carrying value of $4.1 million in Small Business Investment Companies (“SBICs”) where Atlantic Capital is the limited partner. During the second quarter of 2018, and cumulatively for the nine months ended September 30, 2018, the Company recorded impairment in the amount of $228,000 on these SBICs. The impairment resulted from deterioration in the credit quality of one of the SBICs and their inability to pay distributions until their financial position improves. There have been no upward adjustments, cumulatively or year-to-date, on these investments.

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2018
Loans and Leases Receivable Disclosure [Abstract]
Loans and Allowance for Loan Losses	LOANS AND ALLOWANCE FOR LOAN LOSSES The composition of the loan portfolio as of September 30, 2018 and December 31, 2017 , is summarized below. September 30, December 31, (in thousands) Loans held for sale Other loans held for sale $ 1,886 $ 1,487 Total loans held for sale $ 1,886 $ 1,487 Loans held for investment Commercial loans: Commercial and industrial $ 648,349 $ 615,359 Commercial real estate 974,054 940,415 Construction and land 159,781 115,495 Mortgage warehouse participations 27,838 39,981 Total commercial loans 1,810,022 1,711,250 Residential: Residential mortgages 109,522 104,484 Home equity 66,847 76,244 Total residential loans 176,369 180,728 Consumer 33,540 29,393 Other 21,399 16,278 Total loans 2,041,330 1,937,649 Less net deferred fees and other unearned income (2,896 ) (3,810 ) Less allowance for loan losses (20,443 ) (19,344 ) Loans held for investment, net $ 2,017,991 $ 1,914,495 At September 30, 2018 and December 31, 2017 , loans with a carrying value of $720.5 million and $667.2 million , respectively, were pledged as collateral to secure Federal Home Loan Bank of Atlanta (“FHLB”) advances and the Federal Reserve discount window. At September 30, 2018 , the carrying value and outstanding balance of Purchased Credit Impaired (“PCI”) loans accounted for under ASC 310-30 was $6.3 million and $8.3 million , respectively. At December 31, 2017 , the carrying value and outstanding balance of PCI loans accounted for under ASC 310-30 was $11.8 million and $14.1 million , respectively. The following table presents changes in the value of the accretable yield for acquired loans accounted for under ASC 310-30. For the Three Months Ended For the Nine Months Ended September 30, 2018 September 30, 2017 September 30, 2018 September 30, 2017 (in thousands) Balance at beginning of period $ 2,456 $ 3,130 $ 2,316 $ 3,467 Accretion (299 ) (427 ) (898 ) (1,206 ) Reclassification of nonaccretable discount due to change in expected cash flows 180 (202 ) 473 142 Other changes, net 96 281 542 379 Balance at end of period $ 2,433 $ 2,782 $ 2,433 $ 2,782 In addition to the accretable yield on PCI loans, the fair value adjustments on purchased loans outside the scope of ASC 310-30 are also accreted to interest income over the life of the loans. At September 30, 2018 , the remaining accretable fair value discount on loans acquired through a business combination and not accounted for under ASC 310-30 was $2.2 million compared to $2.8 million at December 31, 2017 . The allowance for loan losses represents management’s estimate of probable incurred losses in the loan portfolio as of the end of the period. It is comprised of specific reserves for impaired loans and a general allowance for pools of loans with similar characteristics not individually evaluated. The allowance is regularly evaluated for loan losses to maintain an adequate level to absorb probable current inherent losses in the loan portfolio. Factors contributing to the determination of the allowance include the credit worthiness of the borrower, changes in the value of pledged collateral, and general economic conditions. Most loan commitments rated substandard or worse are specifically reviewed for loss potential. For loans deemed to be impaired, a specific allocation is assigned based on the losses expected to be realized from those loans. The following table presents the balance and activity in the allowance for credit losses by portfolio segment for the three and nine months ended September 30, 2018 and 2017 . 2018 2017 Three Months Ended September 30, Commercial Residential Consumer Total Commercial Residential Consumer Total (in thousands) Allowance for loan losses: Beginning balance $ 18,491 $ 811 $ 281 $ 19,583 $ 20,692 $ 860 $ 318 $ 21,870 Provision for loan losses 761 109 (25 ) 845 273 55 (6 ) 322 Loans charged-off — — — — (3,308 ) (31 ) (7 ) (3,346 ) Recoveries — — 15 15 16 — 8 24 Total ending allowance balance $ 19,252 $ 920 $ 271 $ 20,443 $ 17,673 $ 884 $ 313 $ 18,870 2018 2017 Nine Months Ended September 30, Commercial Residential Consumer Total Commercial Residential Consumer Total (in thousands) Allowance for loan losses: Beginning balance $ 18,267 $ 802 $ 275 $ 19,344 $ 18,717 $ 1,418 $ 460 $ 20,595 Provision for loan losses 1,115 348 (19 ) 1,444 3,152 (451 ) 235 2,936 Loans charged-off (176 ) (230 ) (13 ) (419 ) (4,221 ) (85 ) (396 ) (4,702 ) Recoveries 46 — 28 74 25 2 14 41 Total ending allowance balance $ 19,252 $ 920 $ 271 $ 20,443 $ 17,673 $ 884 $ 313 $ 18,870 The general component of the allowance for loan losses is based on the incurred losses inherent in the portfolio. The loss factors are determined through the generation of probabilities of default (“PDs”) and losses given default (“LGDs”) for groups of similar loans with similar credit grades where Loss Rate = PD x LGD. The PDs and LGDs for the loan portfolio are calculated based on Atlantic Capital’s loss history as well as available market-based data. The loss factor for each pool of loans is adjusted based on qualitative and environmental factors to account for conditions in the current environment which management believes are likely to cause a difference between the calculated loss based on historical performance and the incurred loss in the existing portfolio. These factors include: changes in policies and procedures, changes in the economy, changes in nature or volume of the portfolio and in the terms of loans, changes in lending management, changes in past dues and credit migration, changes in the loan review system, changes in the value of collateral and concentration risk and changes in external factors, such as competition, legal and regulatory. Quarterly, management evaluates these factors to determine an adjustment unique to Atlantic Capital and its market. Charge-offs are recognized when the amount of the loss is quantifiable and timing is known. Collateral based loan charge-offs are measured based on the difference between the loan’s carrying value, including deferred fees, and the estimated net realizable value of the loan. When assessing property value for the purpose of determining a charge-off, a third-party appraisal or an independently derived internal evaluation is generally employed. A loan is considered to be impaired when, based on current information and events, it is probable that all amounts due according to the contractual terms of the loan agreement will not be collected. Loans for which the terms have been modified or granted an economic concession, and for which the borrower is experiencing financial difficulties, are considered troubled debt restructurings (“TDRs”) and classified as impaired. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. A specific allowance is established for individually evaluated impaired loans as needed. Reserves on impaired loans are measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate or the observable market price, or the fair value of the underlying collateral of the loan if the loan is collateral dependent. Atlantic Capital’s policy is to place loans on nonaccrual status, when, in the opinion of management, the principal and interest on a loan is not likely to be repaid in accordance with the loan terms or when the loan becomes 90 days past due and is not both well secured and in the process of collection. When a loan is classified on nonaccrual status, interest previously accrued but not collected is reversed against current interest revenue. Principal and interest payments received on a nonaccrual loan are applied to reduce outstanding principal. PCI loans are considered past due or delinquent when the contractual principal or interest due in accordance with the terms of the loan agreement remains unpaid after the due date of the scheduled payment. Loans accounted for under ASC 310-30 were not classified as nonaccrual at September 30, 2018 or December 31, 2017 , as the carrying value of the respective loan or pool of loans’ cash flows were considered estimable and collection was probable. Therefore, interest revenue, through accretion of the difference between the carrying value of the loans and the expected cash flows (accretable yield), is being recognized on all acquired loans accounted for under ASC 310-30. The balance in the allowance for loan losses and the recorded investment in loans by portfolio segment and based on impairment method is presented in the following table as of September 30, 2018 and December 31, 2017 . September 30, 2018 Commercial Residential Consumer Total (in thousands) Allowance for loan losses: Ending allowance balance attributable to loans Individually evaluated for impairment $ 257 $ — $ — $ 257 Collectively evaluated for impairment 18,995 827 271 20,093 PCI — 93 — 93 Total ending allowance balance $ 19,252 $ 920 $ 271 $ 20,443 Loans: Loans individually evaluated for impairment $ 10,633 $ 192 $ — $ 10,825 Loans collectively evaluated for impairment 1,795,176 174,093 54,929 2,024,198 PCI 4,213 2,084 10 6,307 Total ending loans balance $ 1,810,022 $ 176,369 $ 54,939 $ 2,041,330 December 31, 2017 Commercial Residential Consumer Total (in thousands) Allowance for loan losses: Ending allowance balance attributable to loans Individually evaluated for impairment $ 306 $ — $ — $ 306 Collectively evaluated for impairment 17,918 800 275 18,993 PCI 43 2 — 45 Total ending allowance balance $ 18,267 $ 802 $ 275 $ 19,344 Loans: Loans individually evaluated for impairment $ 6,886 $ 186 $ — $ 7,072 Loans collectively evaluated for impairment 1,694,948 178,204 45,671 1,918,823 PCI 9,416 2,338 — 11,754 Total ending loans balance $ 1,711,250 $ 180,728 $ 45,671 $ 1,937,649 The following table presents information on Atlantic Capital’s impaired loans for the three and nine months ended September 30, 2018 and 2017 : For the Three Months Ended September 30, 2018 2017 Unpaid Principal Balance Recorded Investment Related Allowance Average Balance of Recorded Investment While Impaired Interest Income Recognized During Impairment Unpaid Principal Balance Recorded Investment Related Allowance Average Balance of Recorded Investment While Impaired Interest Income Recognized During Impairment (in thousands) Impaired loans with no related allowance recorded: Commercial and industrial $ 4,455 $ 4,455 $ — $ 4,488 $ 57 $ 2,424 $ 2,361 $ — $ 2,287 $ 14 Commercial real estate 1,725 1,562 — 1,569 — 1,946 1,783 — 1,889 — Construction and land — — — — — — — — — — Residential mortgages 237 192 — 201 1 236 190 — 191 — Home equity — — — — — 529 529 — 531 — Mortgage warehouse — — — — — — — — — — Consumer — — — — — — — — — — Total $ 6,417 $ 6,209 $ — $ 6,258 $ 58 $ 5,135 $ 4,863 $ — $ 4,898 $ 14 Impaired loans with an allowance recorded: Commercial and industrial $ — $ — $ — $ — $ — $ 4,333 $ 4,333 $ 356 $ 4,375 $ 49 Commercial real estate 4,616 4,616 257 4,616 — 572 572 134 576 6 Construction and land — — — — — — — — — — Residential mortgages — — — — — — — — — — Home equity — — — — — — — — — — Mortgage warehouse — — — — — — — — — — Consumer — — — — — — — — — — Total $ 4,616 $ 4,616 $ 257 $ 4,616 $ — $ 4,905 $ 4,905 $ 490 $ 4,951 $ 55 Total impaired loans $ 11,033 $ 10,825 $ 257 $ 10,874 $ 58 $ 10,040 $ 9,768 $ 490 $ 9,849 $ 69 For the Nine Months Ended September 30, 2018 2017 Unpaid Principal Balance Recorded Investment Related Allowance Average Balance of Recorded Investment While Impaired Interest Income Recognized During Impairment Unpaid Principal Balance Recorded Investment Related Allowance Average Balance of Recorded Investment While Impaired Interest Income Recognized During Impairment (in thousands) Impaired loans with no related allowance recorded: Commercial and industrial $ 4,455 $ 4,455 $ — $ 4,584 $ 173 $ 2,424 $ 2,361 $ — $ 2,717 $ 42 Commercial real estate 1,725 1,562 — 1,577 — 1,946 1,783 — 1,925 1 Construction and land — — — — — — — — — — Residential mortgages 237 192 — 203 2 236 190 — 221 — Home equity — — — — — 529 529 — 264 — Mortgage warehouse — — — — — — — — — — Consumer — — — — — — — — — — Total $ 6,417 $ 6,209 $ — $ 6,364 $ 175 $ 5,135 $ 4,863 $ — $ 5,127 $ 43 Impaired loans with an allowance recorded: Commercial and industrial $ — $ — $ — $ — $ — $ 4,333 $ 4,333 $ 356 $ 4,454 $ 149 Commercial real estate 4,616 4,616 257 4,616 — 572 572 134 581 19 Construction and land — — — — — — — — — — Residential mortgages — — — — — — — — — — Home equity — — — — — — — — — — Mortgage warehouse — — — — — — — — — — Consumer — — — — — — — — — — Total $ 4,616 $ 4,616 $ 257 $ 4,616 $ — $ 4,905 $ 4,905 $ 490 $ 5,035 $ 168 Total impaired loans $ 11,033 $ 10,825 $ 257 $ 10,980 $ 175 $ 10,040 $ 9,768 $ 490 $ 10,162 $ 211 Atlantic Capital evaluates loans in accordance with ASC 310-40, Troubled Debt Restructurings by Creditors . TDRs are loans in which Atlantic Capital has modified the terms or granted an economic concession to a borrower who is experiencing financial difficulties. These modifications may include interest rate reductions, term extensions and other concessions intended to minimize losses. As of September 30, 2018 and December 31, 2017 , the Company had a recorded investment in TDRs of $9.1 million and $5.3 million , respectively. The Company had commitments to lend additional funds of $18,000 and $26,000 on loans modified as TDRs, as of September 30, 2018 and December 31, 2017 , respectively. During the three months ended September 30, 2018, the Company extended the interest-only repayment period on a large commercial and industrial loan, resulting in its reclassification to a TDR. During the three months ended September 30, 2017, a large commercial and industrial borrower was sold. As a part of the deficiency agreement, part of the credit relationship was restructured. The restructure included a charge off and the reclassification of the remaining balance to a TDR of $980,000 . Additionally, during the nine months ended September 30, 2017, the modification of terms for one home equity loan included a short term extension of the maturity date. There were no subsequent defaults on prior TDRs during the three and nine month periods ended September 30, 2018 and 2017. Atlantic Capital individually rates loans based on internal credit risk ratings using numerous factors, including thorough analysis of historical and expected cash flows, consumer credit risk scores (FICO scores), rating agency information, LTV ratios, collateral, collection experience, and other internal metrics. Atlantic Capital uses a dual rating system. The likelihood of default of a credit transaction is graded in the Obligor Rating. The risk of loss given default is graded in the Facility Rating. The Obligor Rating is determined through credit analysis. Facility Ratings are used to describe the value to the Company that the collateral represents. Facility Ratings are based on the collateral package or market expectations regarding the value and liquidity of the collateral. Ratings are generally reviewed at least annually or more frequently if there is a material change in creditworthiness. Exceptions to this policy may include well collateralized term loans and loans to individuals with limited exposure or complexity. Atlantic Capital uses the following definitions for risk ratings: Pass: Loans that are analyzed individually as part of the above described process and that do not meet the criteria of special mention, substandard or doubtful. Special Mention: Loans classified as special mention have a potential weakness that requires management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the loan or of the institution’s credit position at some future date. Substandard: Loans classified as substandard are inadequately protected by the current net worth and paying capacity of the obligor or of the collateral pledged, if any. Loans so classified have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that the institution will sustain some loss if the deficiencies are not corrected. Doubtful: Loans classified as doubtful have all the weaknesses inherent in those classified as substandard, with the added characteristic that the weaknesses make collection or liquidation in full, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. As of September 30, 2018 and December 31, 2017 , and based on the most recent analysis performed, the risk category of loans by class of loans is as follows. Pass Special Mention Substandard Accruing Substandard Nonaccruing Doubtful Total (in thousands) September 30, 2018 Commercial and industrial $ 622,599 $ 3,157 $ 21,221 $ 318 $ — $ 647,295 Commercial real estate 952,182 2,079 15,327 — 1,562 971,150 Construction and land 159,505 21 — — — 159,526 Residential mortgages 105,232 1,178 859 315 289 107,873 Home equity 66,002 — 353 57 — 66,412 Mortgage warehouse 27,838 — — — — 27,838 Consumer/Other 54,677 19 58 175 — 54,929 Total loans, excluding PCI loans $ 1,988,035 $ 6,454 $ 37,818 $ 865 $ 1,851 $ 2,035,023 Commercial and industrial $ — $ — $ 1,054 $ — $ — $ 1,054 Commercial real estate 2,370 427 — — 107 2,904 Construction and land 243 5 7 — — 255 Residential mortgages 631 325 693 — — 1,649 Home equity 195 74 166 — — 435 Mortgage warehouse — — — — — — Consumer/Other — — 10 — — 10 Total PCI loans $ 3,439 $ 831 $ 1,930 $ — $ 107 $ 6,307 Pass Special Mention Substandard Accruing Substandard Nonaccruing Doubtful Total (in thousands) December 31, 2017 Commercial and industrial $ 572,942 $ 15,643 $ 21,332 $ 16 $ 2 $ 609,935 Commercial real estate 919,939 6,227 8,906 — 1,592 936,664 Construction and land 115,255 — — — — 115,255 Residential mortgages 100,342 1,075 753 398 321 102,889 Home equity 74,841 64 310 285 — 75,500 Mortgage warehouse 39,981 — — — — 39,981 Consumer/Other 45,422 57 192 — — 45,671 Total loans, excluding PCI loans $ 1,868,722 $ 23,066 $ 31,493 $ 699 $ 1,915 $ 1,925,895 Commercial and industrial $ — $ 3,881 $ 1,543 $ — $ — $ 5,424 Commercial real estate 3,151 212 276 — 112 3,751 Construction and land 222 7 11 — — 240 Residential mortgages 428 493 674 — — 1,595 Home equity 34 354 356 — — 744 Mortgage warehouse — — — — — — Consumer/Other — — — — — — Total PCI loans $ 3,835 $ 4,947 $ 2,860 $ — $ 112 $ 11,754 Atlantic Capital monitors loans by past due status. The following table presents the aging of the recorded investment in past due loans as of September 30, 2018 and December 31, 2017 by class of loans. As of September 30, 2018 Accruing Current Accruing 30-89 Days Past Due Accruing 90+ Days Past Due Nonaccruing PCI Loans Total (in thousands) Loans by Classification Commercial and industrial $ 646,461 $ 516 $ — $ 318 $ 1,054 $ 648,349 Commercial real estate 969,116 472 — 1,562 2,904 974,054 Construction and land 159,518 8 — — 255 159,781 Residential mortgages 106,343 926 — 604 1,649 109,522 Home equity 66,131 224 — 57 435 66,847 Mortgage warehouse 27,838 — — — — 27,838 Consumer 54,747 7 — 175 10 54,939 Total Loans $ 2,030,154 $ 2,153 $ — $ 2,716 $ 6,307 $ 2,041,330 As of December 31, 2017 Accruing Current Accruing 30-89 Days Past Due Accruing 90+ Days Past Due Nonaccruing PCI Loans Total (in thousands) Loans by Classification Commercial and industrial $ 606,677 $ 3,239 $ — $ 19 $ 5,424 $ 615,359 Commercial real estate 932,916 2,156 — 1,592 3,751 940,415 Construction and land 114,988 267 — — 240 115,495 Residential mortgages 100,402 1,470 298 719 1,595 104,484 Home equity 75,081 135 — 284 744 76,244 Mortgage warehouse 39,981 — — — — 39,981 Consumer 45,599 72 — — — 45,671 Total Loans $ 1,915,644 $ 7,339 $ 298 $ 2,614 $ 11,754 $ 1,937,649

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	GOODWILL AND INTANGIBLE ASSETS The carrying amount of goodwill and other intangible assets as of September 30, 2018 and December 31, 2017 is summarized below: September 30, December 31, 2018 2017 (in thousands) Core deposit intangible $ 9,544 $ 9,544 Less: accumulated amortization (5,582 ) (4,624 ) Less: impairment related to divested branches (2,286 ) (2,286 ) Core deposit intangible, net 1,676 2,634 Servicing assets, net 3,191 3,240 Total other intangibles, net 4,867 5,874 Goodwill 21,690 21,759 Total goodwill and other intangible assets, net $ 26,557 $ 27,633 Goodwill impairment in the amount of $69,000 related to the sale of the trust business was recorded during the second quarter of 2018. There were no goodwill impairment charges recorded in the three months ended September 30, 2018 or the three and nine months ended September 30, 2017 . The following table presents activity for goodwill and other intangible assets: For the Three Months Ended September 30, For the Nine Months Ended September 30, Goodwill Core Deposit Intangible Total Goodwill Core Deposit Intangible Total (in thousands) 2018 Balance, beginning of period $ 21,690 $ 1,972 $ 23,662 $ 21,759 $ 2,634 $ 24,393 Amortization — (296 ) (296 ) — (958 ) (958 ) Impairment, due to trust business sale — — — (69 ) — (69 ) Balance, end of period $ 21,690 $ 1,676 $ 23,366 $ 21,690 $ 1,676 $ 23,366 2017 Balance, beginning of period $ 21,759 $ 3,392 $ 25,151 $ 21,759 $ 4,624 $ 26,383 Amortization — (391 ) (391 ) — (1,286 ) (1,286 ) Impairment, due to branch divestiture — — — — (337 ) (337 ) Balance, end of period $ 21,759 $ 3,001 $ 24,760 $ 21,759 $ 3,001 $ 24,760

Servicing Assets

Servicing Assets	9 Months Ended
	Sep. 30, 2018
Transfers and Servicing [Abstract]
Servicing Assets	SERVICING ASSETS SBA Servicing Assets SBA servicing assets are initially recorded at fair value. Subsequently, Atlantic Capital accounts for SBA servicing assets using the amortization method and they are included in other assets. As of September 30, 2018 and December 31, 2017 , the balance of SBA loans sold and serviced by Atlantic Capital totaled $152.2 million and $135.8 million , respectively. Changes in the balance of servicing assets for the three and nine months ended September 30, 2018 and 2017 are presented in the following table . Three months ended September 30, Nine months ended September 30, SBA Loan Servicing Assets 2018 2017 2018 2017 (in thousands) Beginning carrying value, net $ 2,827 $ 2,564 $ 2,635 $ 2,359 Additions 120 157 739 750 Amortization (239 ) (221 ) (666 ) (609 ) Impairment — — — — Ending carrying value $ 2,708 $ 2,500 $ 2,708 $ 2,500 At September 30, 2018 and December 31, 2017 , the sensitivity of the fair value of the SBA loan servicing assets to immediate changes in key economic assumptions are presented in the table below . Sensitivity of the SBA Servicing Assets September 30, 2018 December 31, 2017 (dollars in thousands) Fair value of retained servicing assets $ 2,731 $ 2,865 Weighted average life 5.10 years 6.22 years Prepayment speed: 11.06 % 8.64 % Decline in fair value due to a 10% adverse change $ (123 ) $ (103 ) Decline in fair value due to a 20% adverse change $ (214 ) $ (181 ) Weighted average discount rate 15.72 % 13.01 % Decline in fair value due to a 100 bps adverse change $ (99 ) $ (103 ) Decline in fair value due to a 200 bps adverse change $ (167 ) $ (180 ) The above sensitivities are hypothetical and should be used with caution. As the amounts indicate, changes in fair value based on valuation assumptions generally cannot be extrapolated because the relationship of the change in assumption to the change in fair value may not be linear. Also, the effect of a variation in a particular assumption on the fair value of the retained interest is calculated without changing any other assumption. In reality, changes in one factor may result in changes in another, which might magnify or counteract the sensitivities. TriNet Servicing Assets Changes in the balance of TriNet servicing assets for the three and nine months ended September 30, 2018 and 2017 are presented in the following table. Three months ended September 30, Nine months ended September 30, TriNet Servicing Assets 2018 2017 2018 2017 (in thousands) Beginning carrying value, net $ 523 $ 731 $ 605 $ 825 Additions — — — — Amortization (40 ) (46 ) (122 ) (140 ) Impairment — — — — Ending carrying value $ 483 $ 685 $ 483 $ 685 At September 30, 2018 and December 31, 2017 , the sensitivity of the fair value of the TriNet servicing assets to immediate changes in key economic assumptions are presented in the table below . Sensitivity of the TriNet Servicing Assets September 30, 2018 December 31, 2017 (dollars in thousands) Fair value of retained servicing assets $ 565 $ 697 Weighted average life 7.34 years 7.37 years Prepayment speed: 5.00 % 5.00 % Decline in fair value due to a 10% adverse change $ (8 ) $ (10 ) Decline in fair value due to a 20% adverse change $ (15 ) $ (20 ) Weighted average discount rate 8.00 % 8.00 % Decline in fair value due to a 100 bps adverse change $ (14 ) $ (19 ) Decline in fair value due to a 200 bps adverse change $ (27 ) $ (37 ) The above sensitivities are hypothetical and should be used with caution. As the amounts indicate, changes in fair value based on valuation assumptions generally cannot be extrapolated because the relationship of the change in assumption to the change in fair value may not be linear. Also, the effect of a variation in a particular assumption on the fair value of the retained interest is calculated without changing any other assumption. In reality, changes in one factor may result in changes in another, which might magnify or counteract the sensitivities.

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Other Comprehensive Income (Loss)	OTHER COMPREHENSIVE INCOME (LOSS) Other comprehensive income (loss) for Atlantic Capital consists of changes in net unrealized gains and losses on investment securities available-for-sale and derivatives. The following tables present a summary of the changes in accumulated other comprehensive income (loss) balances for the applicable periods. For the Three Months Ended For the Nine Months Ended September 30, 2018 September 30, 2018 Pre-Tax Amount Income Tax (Expense) Benefit After-Tax Amount Pre-Tax Amount Income Tax (Expense) Benefit After-Tax Amount (in thousands) Accumulated other comprehensive income (loss) beginning of period $ (19,825 ) $ 4,958 $ (14,867 ) $ (6,274 ) $ 2,415 $ (3,859 ) Reclassification of tax effects from AOCI — — — — (844 ) (844 ) Unrealized net gains (losses) on investment securities available-for-sale (4,160 ) 1,041 (3,119 ) (15,097 ) 3,775 (11,322 ) Reclassification adjustment for net realized losses on investment securities available-for-sale — — — 2 (1 ) 1 Unrealized net gains (losses) on derivatives (579 ) 145 (434 ) (3,195 ) 799 (2,396 ) Accumulated other comprehensive income (loss) end of period $ (24,564 ) $ 6,144 $ (18,420 ) $ (24,564 ) $ 6,144 $ (18,420 ) For the Three Months Ended For the Nine Months Ended September 30, 2017 September 30, 2017 Pre-Tax Amount Income Tax (Expense) Benefit After-Tax Amount Pre-Tax Amount Income Tax (Expense) Benefit After-Tax Amount (in thousands) Accumulated other comprehensive income (loss) beginning of period $ (3,690 ) $ 1,420 $ (2,270 ) $ (9,144 ) $ 3,519 $ (5,625 ) Unrealized net gains (losses) on investment securities available-for-sale 706 (272 ) 434 6,366 (2,450 ) 3,916 Reclassification adjustment for net realized losses on investment securities available-for-sale 80 (31 ) 49 80 (31 ) 49 Unrealized net gains (losses) on derivatives (121 ) 46 (75 ) (327 ) 125 (202 ) Accumulated other comprehensive income (loss) end of period $ (3,025 ) $ 1,163 $ (1,862 ) $ (3,025 ) $ 1,163 $ (1,862 )

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Earnings Per Common Share	EARNINGS PER COMMON SHARE Basic earnings per share amounts are computed by dividing net income by the weighted average number of shares of common stock outstanding. Diluted earnings per share amounts are computed by dividing net income by the weighted average number of shares of common stock outstanding and the dilutive effects of the shares awarded under the stock option plan, based on the treasury stock method using an average fair market value of the stock during the respective periods. The following table represents the earnings per share calculations for the three and nine months ended September 30, 2018 and 2017 . Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 (in thousands, except share and per share amounts) Net income available to common shareholders $ 6,513 $ 4,052 $ 19,702 $ 11,611 Weighted average shares outstanding Basic (1) 26,103,397 25,699,179 25,956,336 25,548,646 Effect of dilutive securities: Stock options, warrants and performance share awards 151,375 191,600 178,319 251,205 Diluted 26,254,772 25,890,779 26,134,655 25,799,851 Income per common share: Basic $ 0.25 $ 0.16 $ 0.76 $ 0.45 Diluted $ 0.25 $ 0.16 $ 0.75 $ 0.45 (1) Unvested restricted shares are participating securities and included in basic share calculations. Stock options outstanding of 244 at September 30, 2018 and 550 at September 30, 2017 have not been included in diluted earnings per share because to do so would have been anti-dilutive for the periods presented. These awards were considered anti-dilutive because the exercise price of the award was higher than the market value of the shares. The Amended and Restated Articles of Incorporation of Atlantic Capital authorize Atlantic Capital to issue 110,000,000 shares of capital stock, of which 10,000,000 shares are designated as preferred stock, no par value per share, and 100,000,000 shares are designated as common stock, no par value per share. At September 30, 2018 , 26,103,666 shares of common stock were issued and outstanding. At December 31, 2017 , 25,712,909 shares of common stock were issued and outstanding. The primary source of funds available to Atlantic Capital is payments of dividends from the Bank. The Bank has not paid any dividends to Atlantic Capital in 2018 or 2017. Banking laws and other regulations limit the amount of dividends a bank subsidiary may pay without prior regulatory approval. Additionally, Atlantic Capital’s ability to pay dividends to its shareholders will depend on the ability of the Bank to pay dividends to Atlantic Capital. The Bank is subject to regulatory restrictions on the payment of cash dividends, which generally may be paid only from current earnings.

Derivatives and Hedging

Derivatives and Hedging	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging	DERIVATIVES AND HEDGING Risk Management Atlantic Capital’s objectives in using interest rate derivatives are to add stability to net interest revenue and to manage its exposure to interest rate movements. To accomplish these objectives, Atlantic Capital primarily uses interest rate swaps as part of its interest rate risk management strategy. Cash Flow Hedges At September 30, 2018 , Atlantic Capital’s interest rate swaps designated as cash flow hedges involve the payment of floating-rate amounts to a counterparty in exchange for receiving fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. At September 30, 2018 and December 31, 2017 , Atlantic Capital had interest rate swaps designated as cash flow hedges with aggregate notional amounts of $100.0 million , respectively. No hedge ineffectiveness gains or losses were recognized on active cash flow hedges for the three and nine months ended September 30, 2018 and 2017 . The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. Atlantic Capital expects that approximately $461,000 will be reclassified as a decrease to loan interest income over the next twelve months related to these cash flow hedges. Customer Swaps Atlantic Capital also enters into derivative contracts, which consist of interest rate swaps, to facilitate the needs of customers desiring to manage interest rate risk. These swaps are not designated as accounting hedges under ASC 815, Derivatives and Hedging . To economically hedge the interest rate risk associated with offering this product, Atlantic Capital simultaneously enters into derivative contracts with third parties to offset the customer contracts, such that Atlantic Capital minimizes its net risk exposure resulting from such transactions. The derivative contracts are structured such that the notional amounts reduce over time to generally match the expected amortization of the underlying loans. These derivatives are not speculative and arise from a service provided to clients. Atlantic Capital’s derivative instruments are recorded at fair value in other assets and accrued interest receivable and other liabilities and accrued interest payable in the Consolidated Balance Sheets. The changes in the fair value of the derivative instruments are recognized in other noninterest income in the Consolidated Statements of Income. At September 30, 2018 and December 31, 2017 , Atlantic Capital had interest rate swaps related to this program with an aggregate notional amount of $111.0 million and $142.3 million , respectively. Atlantic Capital acquired a loan level hedging program, which First Security Group, Inc. (“First Security”) utilized to accommodate clients preferring a fixed rate loan. The loan documents include an addendum with a zero premium collar. The zero premium collar is a cap and a floor at the same interest rate, resulting in a fixed rate to the borrower. To hedge this embedded option, First Security entered into a dealer facing trade exactly mirroring the terms in the loan addendum. Counterparty Credit Risk As a result of its derivative contracts, Atlantic Capital is exposed to credit risk. Specifically approved counterparties and exposure limits are defined. Quarterly, the customer derivative contracts and related counterparties are evaluated for credit risk and an adjustment is made to the contract’s fair value. This adjustment is recognized in the Consolidated Statements of Income. Most derivative contracts with clients are secured by collateral. Additionally, in accordance with the interest rate agreements with derivatives dealers, Atlantic Capital may be required to post margin to these counterparties. At September 30, 2018 and December 31, 2017 , Atlantic Capital had minimum collateral posting thresholds with certain of its derivative counterparties and posted collateral of $9.1 million and $8.8 million , respectively, against its obligations under these agreements. Cash collateral related to derivative contracts is recorded in other assets in the Consolidated Balance Sheets. Atlantic Capital has master netting agreements with the derivatives dealers with which it does business, but reflects gross assets and liabilities on the Consolidated Balance Sheets. In conjunction with the FASB’s fair value measurement guidance, management made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting arrangements on a net basis. To accommodate clients, Atlantic Capital occasionally enters into credit risk participation agreements with counterparty banks to accept a portion of the credit risk related to interest rate swaps. This allows clients to execute an interest rate swap with one bank while allowing for distribution of the credit risk among participating members. Credit risk participation agreements arise when Atlantic Capital contracts with other financial institutions, as a guarantor, to share credit risk associated with certain interest rate swaps. These agreements provide for reimbursement of losses resulting from a third party default on the underlying swap. At September 30, 2018 and December 31, 2017 , Atlantic Capital had credit risk participation agreements with a notional amount of $10.0 million and $14.8 million , respectively. The following table reflects the estimated fair value positions of derivative contracts and credit risk participation agreements as of September 30, 2018 and December 31, 2017 : Derivatives designated as hedging instruments under ASC 815 (in thousands) September 30, 2018 December 31, 2017 Interest Rate Products Balance Sheet Location Notional Amount Fair Value Notional Amount Fair Value Cash flow hedge of LIBOR based loans Other liabilities $ 100,000 $ 3,998 $ 100,000 $ 887 Derivatives not designated as hedging instruments under ASC 815 (in thousands) September 30, 2018 December 31, 2017 Interest Rate Products Balance Sheet Location Notional Amount Fair Value Notional Amount Fair Value Customer swap positions Other assets $ 55,483 $ 1,650 $ 71,160 $ 946 Zero premium collar Other assets 91,534 2,922 94,953 2,072 $ 147,017 $ 4,572 $ 166,113 $ 3,018 Dealer offsets to customer swap positions Other liabilities $ 55,483 $ 1,631 $ 71,160 $ 975 Credit risk participation Other liabilities 10,001 1 14,807 4 Dealer offset to zero premium collar Other liabilities 91,534 2,922 94,953 2,157 $ 157,018 $ 4,554 $ 180,920 $ 3,136 The following table presents the effect of the Company’s derivative financial instruments that are not designated as hedging instruments on the Consolidated Statements of Income for the three and nine months ended September 30, 2018 and 2017 . Derivatives not designated as hedging instruments under ASC 815 (in thousands) Location of Gain or (Loss) Recognized in Income on Derivative Amount of Gain or (Loss) Recognized in Income on Derivative Amount of Gain or (Loss) Recognized in Income on Derivative Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Interest rate products Other income / (expense) $ 10 $ (3 ) $ 132 $ (121 ) Other contracts Other income / (expense) — — 4 (6 ) Total $ 10 $ (3 ) $ 136 $ (127 ) Fee income Other income / (expense) $ 10 $ — $ 18 $ 189 The following table reflects the impact to the Consolidated Statements of Income related to derivative contracts for the three and nine months ended September 30, 2018 and 2017 : Derivatives in Cash Flow Hedging Relationships Three Months Ended September 30, Nine Months Ended September 30, (in thousands) Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion) Gain or (Loss) Reclassified from Accumulated OCI in Income (Effective Portion) Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion) Gain or (Loss) Reclassified from Accumulated OCI in Income (Effective Portion) 2018 2017 Location 2018 2017 2018 2017 Location 2018 2017 Interest rate swaps $ (598 ) $ (75 ) Interest income $ (18 ) $ 84 $ (3,093 ) $ (202 ) Interest income $ 103 $ 331

Other Borrowings and Long Term

Other Borrowings and Long Term Debt	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Other Borrowings and Long Term Debt	OTHER BORROWINGS AND LONG TERM DEBT Federal Home Loan Bank borrowings as of September 30, 2018 and December 31, 2017 are as follows: September 30, 2018 December 31, 2017 Balance Interest Rate Balance Interest Rate (in thousands) (in thousands) FHLB short-term borrowings: FHLB short-term borrowings: Fixed rate advance maturing October 1, 2018 $ 30,000 2.09 % Fixed rate advance maturing January 16, 2018 $ 45,000 1.40 % Fixed rate advance maturing October 2, 2018 53,000 2.09 % Total $ 83,000 Total $ 45,000 On September 28, 2015, Atlantic Capital issued subordinated notes (the “Notes”) totaling $50.0 million in aggregate principal amount. The Notes are due September 30, 2025 and bear a fixed rate of interest of 6.25% per year until September 29, 2020. From September 30, 2020 to the maturity date, the interest rate will be a floating rate equal to the three-month LIBOR plus 468 basis points. The Notes were priced at 100% of their par value. The Notes qualify as Tier 2 regulatory capital. Subordinated debt is summarized as follows: September 30, 2018 December 31, 2017 (in thousands) Floating rate 10 year capital securities, with interest paid semi-annually at an annual fixed rate of 6.25% until September 30, 2020 $ 50,000 $ 50,000 Principal amount of subordinated debt $ 50,000 $ 50,000 Less debt issuance costs 338 465 Subordinated debt, net $ 49,662 $ 49,535 All subordinated debt outstanding at September 30, 2018 matures after more than five years.

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	SHARE-BASED COMPENSATION Atlantic Capital sponsors a stock incentive plan for the benefit of directors and employees. Under the Company’s 2015 Stock Incentive Plan (as amended and restated effective May 16, 2018), there were approximately 4,525,000 shares reserved for issuance to directors and employees. The Compensation Committee has the authority to grant the following: an incentive or nonqualified option; a restricted stock award (including a restricted stock award or a restricted unit award); a performance award (including a performance share award or a performance unit award); a phantom stock award; a dividend equivalent award; or any other award granted under the plan. As of September 30, 2018 , approximately 3,515,000 additional awards were available to be granted under the plan. Stock options are granted at a price which is no less than the fair market value of a share of Atlantic Capital common stock on the grant date. Stock options generally vest over three years and expire after ten years. As of September 30, 2018 and December 31, 2017 , no warrants were outstanding for the purchase of common stock. The Company estimates the fair value of its options awards using the Black-Scholes option pricing model. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. The table below summarizes the assumptions used to calculate the fair value of options granted/modified during the nine months ended September 30, 2018 and 2017: For the nine months ended September 30, 2018 2017 Risk‑free interest rate 1.66 % 1.00-1.99% Expected term in years 0.25 0.25-8 Expected stock price volatility 24.2 % 23.2-25.3% Dividend yield — % — % The following table represents stock option activity for the nine months ended September 30, 2018 : Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Outstanding, December 31, 2017 757,711 $ 12.66 Granted/modified (1) 15,000 14.64 Exercised (300,616 ) 13.32 Forfeited (1) (19,935 ) 14.08 Expired (306 ) 105.97 Outstanding, September 30, 2018 451,854 $ 11.97 4.25 $ 2,185 Exercisable, September 30, 2018 371,974 $ 11.39 3.63 $ 2,022 (1) During the nine months ended September 30, 2018, the Company modified options for 15,000 shares. The modifications are included as shares granted/modified and as shares forfeited in this table. Atlantic Capital recognized compensation expense relating to stock options of $70,000 and $167,000 for the three and nine months ended September 30, 2018 , respectively, and $191,000 and $472,000 for the three and nine months ended September 30, 2017 , respectively. Using the Black-Scholes pricing model, the amount of compensation expense was determined based on the fair value of the options at the time of grant, multiplied by the number of options granted that were expected to vest, which was then amortized over the vesting period. In April 2018, the Company granted performance share awards to members of executive management under Atlantic Capital’s Long Term Incentive Plan (“LTIP”). The Company also granted restricted stock awards to certain employees in 2018 under the 2015 Stock Incentive Plan. The following table represents restricted stock and performance share award activity for the nine months ended September 30, 2018 : Shares Weighted Average Grant-Date Fair Value Outstanding, December 31, 2017 239,468 $ 15.69 Granted/modified (1) 135,757 19.89 Exercised (59,300 ) 15.16 Forfeited (1) (30,888 ) 15.97 Outstanding, September 30, 2018 285,037 $ 17.78 (1) During the nine months ended September 30, 2018, the Company modified 6,869 restricted stock awards. The modifications are included as shares granted/modified and as shares forfeited in this table. Compensation expense for restricted stock is based on the fair value of restricted stock awards at the time of grant, which is equal to the value of Atlantic Capital’s common stock on the date of grant. Compensation expense for performance share awards are based on the fair value of certain market conditions and the achievement of performance conditions. The value of restricted stock and performance share grants that are expected to vest is amortized into expense over the vesting period. For the three months ended September 30, 2018 and 2017, compensation expense of $444,000 and $396,000 , respectively, was recognized related to restricted stock and performance share awards. For the nine months ended September 30, 2018 and 2017, compensation expense of $1.3 million and $869,000 , respectively, was recognized related to restricted stock and performance share awards. As of September 30, 2018 , there was $ 2.9 million of unrecognized compensation cost related to restricted stock awards granted under the plan. That cost is expected to be recognized over a weighted-average period of 2.53 years. During the nine months ended September 30, 2018, the Company modified options for 15,000 shares and 6,869 restricted stock awards to two individuals. The modifications allowed for the immediate vesting of the awards upon termination of service. The total incremental cost resulting from the modifications was $111,000 for the nine months ended September 30, 2018.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS Atlantic Capital follows the guidance pursuant to ASC 820-10, Fair Value Measurements and Disclosures . This guidance defines fair value, establishes a framework for measuring fair value and expands disclosures about fair value measurements. This issuance applies to reported balances that are required or permitted to be measured at fair value under existing accounting pronouncements; accordingly, the standard does not require any new fair value measurements of reported balances. Atlantic Capital measures its investment securities and interest rate derivative assets and liabilities at fair value on a recurring basis. Fair value is used on a nonrecurring basis either when assets are evaluated for impairment or for disclosure purposes. Atlantic Capital measures its servicing assets, goodwill, intangible assets, SBIC investments, loans held for sale, impaired loans and other real estate owned at fair value on a nonrecurring basis if necessary. The guidance emphasizes that fair value is a market-based measurement, not an entity-specific measurement and defines fair value as the price that could be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, this guidance establishes a fair value hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity (observable inputs that are classified within Levels 1 and 2 of the hierarchy) and the reporting entity’s own assumptions about market participant assumptions (unobservable inputs classified within Level 3 of the hierarchy). Atlantic Capital applied the following fair value hierarchy: Level 1 – Assets or liabilities for which the identical item is traded on an active exchange, such as publicly-traded instruments or futures contracts. Level 2 – Assets or liabilities valued based on observable market data for similar instruments. Level 3 – Assets or liabilities for which significant valuation assumptions are not readily observable in the market, instruments valued based on the best available data, some of which is internally-developed, and risk premiums that a market participant would require. In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement. There were no transfers between Level 1 and Level 2 or Level 2 and Level 3 during the nine months ended September 30, 2018 and 2017. Atlantic Capital records investment securities available-for-sale at fair value on a recurring basis. Investment securities classified as available-for-sale are reported at fair value utilizing Level 2 inputs. For these securities, Atlantic Capital obtains fair value measurements from an independent pricing service. In estimating the fair values for investment securities, Atlantic Capital believes that independent third-party market prices are the best evidence of an exit price. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the Treasury Department yield curve, trade execution data, market consensus prepayment speeds, credit information and the securities’ terms and conditions, among other things. Derivative instruments are primarily transacted as over-the-counter trades and priced with observable market assumptions. Ongoing measurements include observable market assumptions with appropriate valuation adjustments for liquidity and for credit risk of counterparties and Atlantic Capital’s own credit. For these instruments, Atlantic Capital obtains fair value measurements from an independent pricing service. The fair value measurements consider factors such as the current level of interest rates, the likelihood of default by Atlantic Capital and its counterparties, total exposure and remaining maturities in determining the appropriate fair value adjustments to record. Generally, the expected loss of each client counterparty is estimated using Atlantic Capital’s internal risk rating system. For financial institution counterparties that are rated by national rating agencies, those ratings are used in determining the credit risk. This approach used to estimate exposures to counterparties is also used by Atlantic Capital to estimate its own credit risk on derivative liability positions. Assets and Liabilities Measured at Fair Value on a Recurring Basis The following table presents the assets that were measured at fair value on a recurring basis by level within the fair value hierarchy as reported in the Consolidated Balance Sheets at September 30, 2018 and December 31, 2017 . Fair Value Measurements at September 30, 2018 Using: Quoted Prices in Active Markets for Identical Securities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total (in thousands) Securities available-for-sale— U.S. government agencies $ — $ 35,445 $ — $ 35,445 U.S. states and political subdivisions — 82,665 — 82,665 Trust preferred securities — 4,625 — 4,625 Corporate debt securities — 12,369 — 12,369 Mortgage-backed securities — 330,652 — 330,652 Total securities available-for-sale $ — $ 465,756 $ — $ 465,756 Interest rate derivative assets $ — $ 4,572 $ — $ 4,572 Interest rate derivative liabilities $ — $ 8,552 $ — $ 8,552 Fair Value Measurements at December 31, 2017 Using: Quoted Prices in Active Markets for Identical Securities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total (in thousands) Securities available-for-sale— U.S. government agencies $ — $ 34,111 $ — $ 34,111 U.S. states and political subdivisions — 90,001 — 90,001 Trust preferred securities — 4,650 — 4,650 Corporate debt securities — 12,622 — 12,622 Mortgage-backed securities — 307,733 — 307,733 Total securities available-for-sale $ — $ 449,117 $ — $ 449,117 Interest rate derivative assets $ — $ 3,018 $ — $ 3,018 Interest rate derivative liabilities $ — $ 4,023 $ — $ 4,023 For the nine months ended September 30, 2018 and 2017 , there was not a change in the methods and significant assumptions used to estimate fair value. Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis The following table presents the assets that were measured at fair value on a nonrecurring basis by level within the fair value hierarchy as reported in the Consolidated Balance Sheets at September 30, 2018 and December 31, 2017 . September 30, 2018 Level 1 Fair Value Measurement Level 2 Fair Value Measurement Level 3 Fair Value Measurement Total (in thousands) Impaired Loans $ — $ — $ 1,588 $ 1,588 December 31, 2017 Level 1 Fair Value Measurement Level 2 Fair Value Measurement Level 3 Fair Value Measurement Total (in thousands) Impaired Loans $ — $ — $ 2,199 $ 2,199 Level 3 loans consist of impaired loans which have been partially charged-off or have specific valuation allowances. The fair value of Level 3 assets is estimated based on the underlying collateral value. For loans which the cash proceeds from the sale of the underlying collateral is the expected source of repayment, the fair value of these loans was derived from internal estimates of the underlying collateral incorporating market data, including third party appraisals or evaluations, when available. Appraised values may be discounted based on management’s assessment of the level of inactivity in the real estate market and other markets for the underlying collateral, changes in market conditions from the time of the valuation, and other information that in management’s judgment may affect the value. Impaired loans are evaluated on at least a quarterly basis and adjusted accordingly. Assets and Liabilities Not Measured at Fair Value For financial instruments that have quoted market prices, those quotes are used to determine fair value. Financial instruments that have no defined maturity, have a remaining maturity of 180 days or less, or reprice frequently to a market rate, are assumed to have a fair value that approximates the reported book value, after taking into consideration any applicable credit risk. If no market quotes are available, financial instruments are valued by discounting the expected cash flows using an estimated current market interest rate for the financial instrument. For loans held for investment, fair value is measured using the exit price notion. For off-balance sheet derivative instruments, fair value is estimated as the amount that Atlantic Capital would receive or pay to terminate the contracts at the reporting date, taking into account the current unrealized gains or losses on open contracts. The short maturity of Atlantic Capital’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 in other banks, other short-term investments, and FHLB stock. The fair value of securities available-for-sale equals the balance sheet value. Due to the short-term settlement of accrued interest receivable and payable, the carrying amount closely approximates fair value. Fair value estimates are made at a specific point in time, based on relevant market information and information about the financial instrument. These estimates do not reflect the premium or discount on any particular financial instrument that could result from the sale of Atlantic Capital’s entire holdings. Because no ready market exists for a significant portion of Atlantic Capital’s financial instruments, fair value estimates are based on many judgments. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. Changes in assumptions could significantly affect the estimates. Off-balance sheet financial instruments (commitments to extend credit and standby letters of credit) are generally short-term and at variable rates. Therefore, both the carrying amount and the estimated fair value associated with these instruments are immaterial. The following table presents the estimated fair values of Atlantic Capital’s financial instruments at September 30, 2018 and December 31, 2017 . Fair Value Measurements at September 30, 2018 Using: Carrying Value Quoted Prices in Active markets for Identical Securities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) Financial assets Cash and due from banks $ 28,007 $ 28,007 $ — $ — Interest bearing deposits in banks 140,682 140,682 — — Other short-term investments 20,898 20,898 — — Total securities available-for-sale 465,756 — 465,756 — FHLB stock 6,150 — — 6,150 Federal Reserve Bank stock 9,842 — — 9,842 Loans held for investment, net 2,017,991 — — 1,963,794 Loans held for sale 1,886 — 1,886 — Derivative assets 4,572 — 4,572 — Financial liabilities Deposits $ 2,379,824 $ — $ 2,208,910 $ — Federal funds purchased and securities sold under agreements to repurchase 8,904 8,904 — — Subordinated debt 49,662 — 48,995 — FHLB advances 83,000 — 83,011 — Derivative financial instruments 8,552 — 8,552 — Fair Value Measurements at December 31, 2017 Using: Carrying Value Quoted Prices in Active markets for Identical Securities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) Financial assets Cash and due from banks $ 38,086 $ 38,086 $ — $ — Interest-bearing deposits in other banks 281,247 281,247 — — Other short-term investments 10,681 10,681 — — Total securities available-for-sale 449,117 — 449,117 — FHLB stock 4,388 — — 4,388 Federal Reserve Bank stock 9,792 — — 9,792 Loans held for investment, net 1,914,495 — — 1,955,705 Loans held for sale 1,487 — 1,487 — Derivative assets 3,018 — 3,018 — Financial liabilities Deposits $ 2,450,665 $ — $ 2,411,810 $ — Subordinated debt 49,535 — 49,888 — FHLB advances 45,000 — 45,057 — Derivative financial instruments 4,023 — 4,023 —

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Atlantic Capital is a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and letters of credit, most of which are standby letters of credit. These instruments involve, to varying degrees, elements of credit risk in excess of the amounts recognized in the Consolidated Balance Sheets. The contract amounts of these instruments reflect the extent of involvement Atlantic Capital has in particular classes of financial instruments. Standby letters of credit are written conditional commitments issued by Atlantic Capital to guarantee the performance of a customer to a third party. Those guarantees are primarily issued to support public and private borrowing arrangements. Most letters of credit expire in less than one year. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. Atlantic Capital’s exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit and standby letters of credit is represented by the contractual amount of those instruments. Atlantic Capital uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments. Atlantic Capital’s maximum exposure to credit risk for unfunded loan commitments and standby letters of credit at September 30, 2018 and December 31, 2017 was as follows: September 30, December 31, (in thousands) Financial Instruments whose contract amount represents credit risk: Commitments to extend credit $ 717,847 $ 689,753 Standby letters of credit 13,006 10,958 $ 730,853 $ 700,711 Atlantic Capital, in the normal course of business, is subject to various pending and threatened lawsuits in which claims for monetary damages are asserted. Although it is not possible to predict the outcome of these lawsuits, or the range of any possible loss, management, after consultation with legal counsel, does not anticipate that the ultimate aggregate liability, if any, arising from these lawsuits will have a material adverse effect on Atlantic Capital’s financial position or results of operations.

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue Recognition	REVENUE RECOGNITION On January 1, 2018, the Company adopted ASU No. 2014-09 “Revenue from Contracts with Customers” (Topic 606) and all subsequent ASUs that modified Topic 606. As stated in Note 2, Accounting Standards Updates and Recently Adopted Standards , the implementation of the new standard did not result in any significant changes to the Company’s methodology of recognizing revenue; as such, the Company recorded a cumulative effect adjustment to first quarter 2018 opening retained earnings in an amount less than $2,000 . Results for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts were not adjusted and continue to be reported in accordance with the Company’s historic accounting under Topic 605. Topic 606 does not apply to revenue associated with financial instruments, including revenue from loans and securities. In addition, certain noninterest income streams such as fees associated with financial guarantees and derivatives are also not in scope of the new guidance. Topic 606 is applicable to noninterest revenue streams such as service charges on deposit accounts and trust and asset management income. However, the recognition of these revenue streams did not change significantly upon adoption of Topic 606. Substantially all of the Company’s revenue is generated from contracts with customers. Noninterest revenue streams within the scope of Topic 606 are discussed below. Service Charges on Deposit Accounts Service charges represent general service fees for monthly account maintenance and activity, or transaction-based fees and consist of transaction-based revenue, time-based revenue (service period), item-based revenue or some other individual attribute-based revenue. Revenue is recognized when the performance obligation is completed which is generally monthly for account maintenance services or when a transaction has been completed, such as a wire transfer or ATM withdrawal. Payment for such performance obligations are generally received at the time the performance obligations are satisfied. The following table presents service charges by type of service provided for the three and nine months ended September 30, 2018 and 2017: For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) Deposit account analysis fees and charges $ 654 $ 551 $ 1,860 $ 1,567 ATM fees 276 370 863 1,182 NSF fees 177 176 541 625 Wire fees 110 88 302 266 Foreign Exchange Fees 54 50 186 186 Other 7 12 26 44 $ 1,278 $ 1,247 $ 3,778 $ 3,870 Trust and Asset Management Trust and asset management income is primarily comprised of fees earned from the management and administration of trusts and other customer assets. The Company’s performance obligation is generally satisfied over time and the resulting fees are recognized monthly, based upon the month-end market value of the assets under management and the applicable fee rate. Payment is generally received a few days after month end through a direct charge to customers’ accounts. The Company’s performance obligation for these transactional-based services is generally satisfied, and related revenue recognized, at a point in time (i.e., as incurred). Payment is received shortly after services are rendered. During the second quarter of 2018, Atlantic Capital sold its trust business, Southeastern Trust Company. The following table presents trust income by type of service provided for the three and nine months ended September 30, 2018 and 2017: For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) Personal trust and agency accounts $ — $ 259 $ 616 $ 728 Employee benefit and retirement-related trust and agency accounts — 58 120 166 Investment management and investment advisory agency accounts — 89 217 263 Custody and safekeeping accounts — 12 26 43 Other — 19 46 132 $ — $ 437 $ 1,025 $ 1,332 Other Other noninterest income consists of other recurring revenue streams such as check printing income, safety deposit box rental fees, and other miscellaneous revenue streams. Check printing income is recognized ratably over the contract period as the Company satisfies its performance obligation to sell a specific number of check packages. Safe deposit box rental fees are charged to the customer annually and recognized upon receipt of payment. The Company determined that since rentals and renewals occur fairly consistently over time, revenue is recognized on a basis consistent with the duration of the performance obligation. Contract Balances A contract asset balance occurs when an entity performs a service for a customer before the customer pays consideration (resulting in a contract receivable) or before payment is due (resulting in a contract asset). A contract liability balance is an entity’s obligation to transfer a service to a customer for which the entity has already received payment (or payment is due) from the customer. The Company’s noninterest revenue streams are largely based on transactional activity, or standard month-end revenue accruals such as asset management fees based on month-end market values. Consideration is often received immediately or shortly after the Company satisfies its performance obligation and revenue is recognized. The Company does not typically enter into long-term revenue contracts with customers, and therefore, does not experience significant contract balances. As of September 30, 2018 and December 31, 2017 , the Company did not have any significant contract balances.

Accounting Policies and Basis_2

Accounting Policies and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accounting and financial reporting policies of Atlantic Capital Bancshares, Inc. (“Atlantic Capital” or the “Company”) and its subsidiary, Atlantic Capital Bank, N.A. (the “Bank”), conform to accounting principles generally accepted in the United States of America (“GAAP”) and general banking industry practices. The accompanying interim consolidated financial statements have not been audited. All material intercompany balances and transactions have been eliminated. In management’s opinion, all accounting adjustments necessary to accurately reflect the financial position and results of operations on the accompanying financial statements have been made. These adjustments are normal and recurring accruals considered necessary for a fair and accurate presentation. The accompanying consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in Atlantic Capital’s filing on Form 10-K. The results for interim periods are not necessarily indicative of results for the full year or any other interim periods. Certain prior period amounts have been reclassified to conform to the current year presentation.
Accounting Standards Updates and Recently Adopted Standards	Recently Adopted Accounting Pronouncements In February 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-02, “Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” The guidance gives entities the option to reclassify into retained earnings tax effects related to items in accumulated other comprehensive income (“OCI”) that were stranded in accumulated OCI as a result of tax reform. It is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption in any period is permitted and Atlantic Capital adopted ASU 2018-02 as of January 1, 2018. The adoption of this update resulted in a reclassification of approximately $844,000 between accumulated OCI and retained earnings, and a net impact of zero to total shareholders’ equity. In August 2017, the FASB issued ASU 2017-12, “Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities.” The purpose of this updated guidance is to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. ASU 2017-12 is effective for public business entities for fiscal years beginning after December 15, 2018, with early adoption, including adoption in an interim period, permitted. Atlantic Capital adopted ASU 2017-12 as of January 1, 2018. The guidance requires a modified retrospective transition method resulting in the cumulative effect of the change on the opening balance of each affected component of equity in the statement of financial position as of the date of adoption. Adoption did not have a material impact on Atlantic Capital’s consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, “Compensation - Stock Compensation (Topic 718): Scope and Modification Accounting.” The amendments in this ASU provide guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in accordance with Topic 718. The amendments were effective for interim and annual reporting periods beginning after December 15, 2017. This ASU did not have a material impact on Atlantic Capital’s consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” to address diversity in how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The amendments provide guidance on the following eight specific cash flow issues: 1) debt prepayment or debt extinguishment costs; 2) settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; 3) contingent consideration payments made after a business combination; 4) proceeds from the settlement of insurance claims; 5) proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies; 6) distributions received from equity method investees; 7) beneficial interests in securitization transactions; and 8) separately identifiable cash flows and application of the predominance principle. The amendments were effective for public companies for fiscal years beginning after December 31, 2017, and interim periods within those fiscal years. This ASU did not have a material impact on the Company’s consolidated financial statements. In January 2016, the FASB issued ASU 2016-1, “Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Liabilities.” The guidance in this update requires that equity investments (except those accounted for under the equity method of accounting) be measured at fair value with changes in fair value recognized in net income. However, an entity may choose to measure equity investments that do not have readily determinable fair values at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. The guidance also simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment. In addition, the guidance requires that public business entities base their fair value disclosures for financial instruments that are not measured at fair value in the financial statements on the exit price notion. For public entities, this update was effective for fiscal years beginning after December 15, 2017. The adoption of this update did not have a material impact on Atlantic Capital’s consolidated financial statements, however Atlantic Capital changed the disclosure of financial instruments not measured at fair value to reflect the exit price notion. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers.” The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. For public companies, this guidance was effective for annual and interim periods beginning after December 15, 2017. Atlantic Capital completed its review of the impact of ASU 2014-09 on components of non-interest income and did not find any significant changes to its methodology of recognizing revenue. Revenue streams impacted by the ASU included service charges, trust income, sales of financed other real estate, and check printing revenue. The Company recorded a cumulative effect adjustment to first quarter 2018 opening retained earnings in an amount less than $2,000 , and included newly applicable revenue disclosures. Recently Issued Accounting Pronouncements Not Yet Adopted In August 2018, the FASB issued ASU No. 2018-13, “ Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement.” The amendments in this update modify the disclosure requirements for fair value measurements by removing, modifying, or adding certain disclosures. The update is effective for interim and annual periods in fiscal years beginning after December 31, 2019, with early adoption permitted for the removed disclosures and delayed adoption until fiscal year 2020 permitted for new disclosures. The removed and modified disclosures will be adopted on a retrospective basis and the new disclosures will be adopted on a prospective basis. The adoption will not have a material effect on the Company’s consolidated financial statements. In March 2017, the FASB issued ASU 2017-08, “Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities.” This guidance shortens the premium amortization period for certain callable debt securities by requiring amortization to the earliest call date. The standard is effective for public companies for annual and interim periods beginning after December 15, 2020. The adoption of this update is not expected to have a material impact on Atlantic Capital’s consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment,” which intends to simplify goodwill impairment testing by eliminating the second step of the analysis under which the implied fair value of goodwill is determined as if the reporting unit were being acquired in a business combination. The update instead requires entities to compare the fair value of a reporting unit with its carrying amount and recognize an impairment charge for any amount by which the carrying amount exceeds the reporting unit’s fair value, to the extent that the loss recognized does not exceed the amount of goodwill allocated to that reporting unit. ASU 2017-04 must be applied prospectively and is effective for the Company on January 1, 2020. Early adoption is permitted. Atlantic Capital does not expect the new guidance to have a material impact on its financial condition or results of operations. In June 2016, the FASB issued ASU 2016-13, “Financial Instruments - Credit Losses (Topic 326) Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires an entity to utilize a new impairment model known as the current expected credit loss (“CECL”) model to estimate its lifetime “expected credit loss” and record an allowance that, when deducted from the amortized cost basis of the financial asset, presents the net amount expected to be collected on the financial asset. The CECL model is expected to result in more timely recognition of credit losses. ASU 2016-13 also requires new disclosures for financial assets measured at amortized cost, loans and available-for-sale debt securities. ASU 2016-13 is effective for public companies for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. Entities will apply the standard’s provisions as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The Company has established a CECL working group with the expertise needed to implement the guidance. Members of the working group have developed a project task plan and timeline and are also attending conferences and meetings with audit firms, bank regulators and other banks to keep current on evolving interpretations of the guidance. The Company is implementing a software package supported by a third-party vendor to automate the calculation of the allowance for loan losses under the new methodology. Atlantic Capital is in the process of evaluating the impact of the adoption of ASU 2016-13 on the Company’s consolidated financial statements and disclosures. In February 2016, the FASB issued ASU 2016-2, “Leases.” Under the new guidance, leases classified as operating leases under previous GAAP must be recorded on the balance sheet. A lessee should recognize in the statement of financial position a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The standard is effective for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted. The new standard must be adopted using a modified retrospective transition, and provides for certain practical expedients. Upon adoption, Atlantic Capital expects to report higher assets and liabilities as a result of including leases on the consolidated balance sheet. The Company does not expect the new guidance to have a material impact on the consolidated statement of income or the consolidated statement of shareholders’ equity.

Balance Sheet Offsetting (Table

Balance Sheet Offsetting (Tables)	9 Months Ended
	Sep. 30, 2018
Offsetting [Abstract]
Offsetting Assets	The following table presents a summary of amounts outstanding under reverse repurchase agreements, repurchase agreements, and derivative financial instruments including those entered into in connection with the same counterparty under master netting agreements as of September 30, 2018 and December 31, 2017 . While these agreements are typically over-collateralized, U.S. GAAP requires disclosures in this table to limit the amount of such collateral to the amount of the related recognized asset or liability for each counterparty. (in thousands) Gross Amounts not Offset in the Balance Sheet September 30, 2018 Gross Amounts of Recognized Assets Gross Amounts Offset on the Balance Sheet Net Asset Balance Financial Instruments Cash Collateral Received Net Amount Reverse repurchase agreements $ 20,898 $ — $ 20,898 $ (20,898 ) $ — $ — Derivatives 4,572 — 4,572 — — 4,572 Total $ 25,470 $ — $ 25,470 $ (20,898 ) $ — $ 4,572 Gross Amounts not Offset in the Balance Sheet Gross Amounts of Recognized Liabilities Gross Amounts Offset on the Balance Sheet Net Liability Balance Financial Instruments Cash Collateral Pledged Net Amount Repurchase agreements $ 8,904 $ — $ 8,904 $ (10,828 ) $ — $ — Derivatives 8,552 — 8,552 (7,226 ) (1,326 ) — Total $ 17,456 $ — $ 17,456 $ (18,054 ) $ (1,326 ) $ — Gross Amounts not Offset in the Balance Sheet December 31, 2017 Gross Amounts of Recognized Assets Gross Amounts Offset on the Balance Sheet Net Asset Balance Financial Instruments Cash Collateral Received Net Amount Reverse repurchase agreements $ 10,681 $ — $ 10,681 $ (10,681 ) $ — $ — Derivatives 3,018 — 3,018 — — 3,018 Total $ 13,699 $ — $ 13,699 $ (10,681 ) $ — $ 3,018 Gross Amounts not Offset in the Balance Sheet Gross Amounts of Recognized Liabilities Gross Amounts Offset on the Balance Sheet Net Liability Balance Financial Instruments Cash Collateral Pledged Net Amount Repurchase agreements $ — $ — $ — $ — $ — $ — Derivatives 4,023 — 4,023 (2,705 ) (1,318 ) — Total $ 4,023 $ — $ 4,023 $ (2,705 ) $ (1,318 ) $ —
Offsetting Liabilities	The following table presents a summary of amounts outstanding under reverse repurchase agreements, repurchase agreements, and derivative financial instruments including those entered into in connection with the same counterparty under master netting agreements as of September 30, 2018 and December 31, 2017 . While these agreements are typically over-collateralized, U.S. GAAP requires disclosures in this table to limit the amount of such collateral to the amount of the related recognized asset or liability for each counterparty. (in thousands) Gross Amounts not Offset in the Balance Sheet September 30, 2018 Gross Amounts of Recognized Assets Gross Amounts Offset on the Balance Sheet Net Asset Balance Financial Instruments Cash Collateral Received Net Amount Reverse repurchase agreements $ 20,898 $ — $ 20,898 $ (20,898 ) $ — $ — Derivatives 4,572 — 4,572 — — 4,572 Total $ 25,470 $ — $ 25,470 $ (20,898 ) $ — $ 4,572 Gross Amounts not Offset in the Balance Sheet Gross Amounts of Recognized Liabilities Gross Amounts Offset on the Balance Sheet Net Liability Balance Financial Instruments Cash Collateral Pledged Net Amount Repurchase agreements $ 8,904 $ — $ 8,904 $ (10,828 ) $ — $ — Derivatives 8,552 — 8,552 (7,226 ) (1,326 ) — Total $ 17,456 $ — $ 17,456 $ (18,054 ) $ (1,326 ) $ — Gross Amounts not Offset in the Balance Sheet December 31, 2017 Gross Amounts of Recognized Assets Gross Amounts Offset on the Balance Sheet Net Asset Balance Financial Instruments Cash Collateral Received Net Amount Reverse repurchase agreements $ 10,681 $ — $ 10,681 $ (10,681 ) $ — $ — Derivatives 3,018 — 3,018 — — 3,018 Total $ 13,699 $ — $ 13,699 $ (10,681 ) $ — $ 3,018 Gross Amounts not Offset in the Balance Sheet Gross Amounts of Recognized Liabilities Gross Amounts Offset on the Balance Sheet Net Liability Balance Financial Instruments Cash Collateral Pledged Net Amount Repurchase agreements $ — $ — $ — $ — $ — $ — Derivatives 4,023 — 4,023 (2,705 ) (1,318 ) — Total $ 4,023 $ — $ 4,023 $ (2,705 ) $ (1,318 ) $ —

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale Securities Reconciliation	The following table presents the amortized cost, unrealized gains and losses, and fair value of securities available-for-sale at September 30, 2018 and December 31, 2017 . Available-For-Sale Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) September 30, 2018 Debt securities— U.S. Government agencies $ 36,708 $ — $ (1,263 ) $ 35,445 U.S. states and political divisions 91,656 2 (8,993 ) 82,665 Trust preferred securities 4,774 — (149 ) 4,625 Corporate debt securities 12,879 — (510 ) 12,369 Residential mortgage-backed securities 340,417 2,427 (12,192 ) 330,652 Total $ 486,434 $ 2,429 $ (23,107 ) $ 465,756 December 31, 2017 Debt securities— U.S. Government agencies $ 34,699 $ 11 $ (599 ) $ 34,111 U.S. states and political divisions 92,169 237 (2,405 ) 90,001 Trust preferred securities 4,754 — (104 ) 4,650 Corporate debt securities 12,948 60 (386 ) 12,622 Residential mortgage-backed securities 310,129 2,423 (4,819 ) 307,733 Total $ 454,699 $ 2,731 $ (8,313 ) $ 449,117
Investments Classified by Contractual Maturity Date	The following table presents the amortized cost and fair value of debt securities by contractual maturity at September 30, 2018 . Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Available-For-Sale Amortized Cost Fair Value (in thousands) Within 1 year $ 246 $ 245 Over 1 year through 5 years 30,299 29,151 5 years to 10 years 47,062 45,326 Over 10 years 68,410 60,382 146,017 135,104 Residential mortgage-backed securities 340,417 330,652 Total $ 486,434 $ 465,756
Continuous Unrealized Loss Position, Fair Value	The following table summarizes available-for-sale securities in an unrealized loss position as of September 30, 2018 and December 31, 2017 . Less than 12 months 12 months or greater Totals Available-For-Sale Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands) September 30, 2018 U.S. Government agencies $ 11,983 $ (310 ) $ 23,462 $ (952 ) $ 35,445 $ (1,262 ) U.S. states and political divisions 22,182 (1,301 ) 59,978 (7,693 ) 82,160 (8,994 ) Trust preferred securities 4,625 (149 ) — — 4,625 (149 ) Corporate debt securities 7,446 (141 ) 4,922 (369 ) 12,368 (510 ) Residential mortgage-backed securities 133,239 (3,224 ) 184,247 (8,968 ) 317,486 (12,192 ) Totals $ 179,475 $ (5,125 ) $ 272,609 $ (17,982 ) $ 452,084 $ (23,107 ) December 31, 2017 U.S. Government agencies $ 22,148 $ (348 ) $ 9,145 $ (251 ) $ 31,293 $ (599 ) U.S. states and political divisions 14,009 (183 ) 58,744 (2,222 ) 72,753 (2,405 ) Trust preferred securities — — 4,650 (104 ) 4,650 (104 ) Corporate debt securities 2,989 (27 ) 2,970 (359 ) 5,959 (386 ) Residential mortgage-backed securities 155,637 (1,344 ) 126,580 (3,475 ) 282,217 (4,819 ) Totals $ 194,783 $ (1,902 ) $ 202,089 $ (6,411 ) $ 396,872 $ (8,313 )
Schedule of Realized Gain (Loss) on Securities	Realized gains and losses are derived using the specific identification method for determining the cost of securities sold. The following table summarizes securities sales activity for the three and nine months ended September 30, 2018 and 2017 . Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) Proceeds from sales $ — $ 1,813 $ 24 $ 1,813 Gross realized gains — — — — Gross realized losses — (80 ) (2 ) (80 ) Net losses on sales of securities $ — $ (80 ) $ (2 ) $ (80 )

Loans and Allowance for Loan _2

Loans and Allowance for Loan Losses (Tables)	9 Months Ended
	Sep. 30, 2018
Loans and Leases Receivable Disclosure [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	The composition of the loan portfolio as of September 30, 2018 and December 31, 2017 , is summarized below. September 30, December 31, (in thousands) Loans held for sale Other loans held for sale $ 1,886 $ 1,487 Total loans held for sale $ 1,886 $ 1,487 Loans held for investment Commercial loans: Commercial and industrial $ 648,349 $ 615,359 Commercial real estate 974,054 940,415 Construction and land 159,781 115,495 Mortgage warehouse participations 27,838 39,981 Total commercial loans 1,810,022 1,711,250 Residential: Residential mortgages 109,522 104,484 Home equity 66,847 76,244 Total residential loans 176,369 180,728 Consumer 33,540 29,393 Other 21,399 16,278 Total loans 2,041,330 1,937,649 Less net deferred fees and other unearned income (2,896 ) (3,810 ) Less allowance for loan losses (20,443 ) (19,344 ) Loans held for investment, net $ 2,017,991 $ 1,914,495
Schedule of Accretable Yield	The following table presents changes in the value of the accretable yield for acquired loans accounted for under ASC 310-30. For the Three Months Ended For the Nine Months Ended September 30, 2018 September 30, 2017 September 30, 2018 September 30, 2017 (in thousands) Balance at beginning of period $ 2,456 $ 3,130 $ 2,316 $ 3,467 Accretion (299 ) (427 ) (898 ) (1,206 ) Reclassification of nonaccretable discount due to change in expected cash flows 180 (202 ) 473 142 Other changes, net 96 281 542 379 Balance at end of period $ 2,433 $ 2,782 $ 2,433 $ 2,782
Schedule of Credit Losses Related to Financing Receivables, Current and Noncurrent	The following table presents the balance and activity in the allowance for credit losses by portfolio segment for the three and nine months ended September 30, 2018 and 2017 . 2018 2017 Three Months Ended September 30, Commercial Residential Consumer Total Commercial Residential Consumer Total (in thousands) Allowance for loan losses: Beginning balance $ 18,491 $ 811 $ 281 $ 19,583 $ 20,692 $ 860 $ 318 $ 21,870 Provision for loan losses 761 109 (25 ) 845 273 55 (6 ) 322 Loans charged-off — — — — (3,308 ) (31 ) (7 ) (3,346 ) Recoveries — — 15 15 16 — 8 24 Total ending allowance balance $ 19,252 $ 920 $ 271 $ 20,443 $ 17,673 $ 884 $ 313 $ 18,870 2018 2017 Nine Months Ended September 30, Commercial Residential Consumer Total Commercial Residential Consumer Total (in thousands) Allowance for loan losses: Beginning balance $ 18,267 $ 802 $ 275 $ 19,344 $ 18,717 $ 1,418 $ 460 $ 20,595 Provision for loan losses 1,115 348 (19 ) 1,444 3,152 (451 ) 235 2,936 Loans charged-off (176 ) (230 ) (13 ) (419 ) (4,221 ) (85 ) (396 ) (4,702 ) Recoveries 46 — 28 74 25 2 14 41 Total ending allowance balance $ 19,252 $ 920 $ 271 $ 20,443 $ 17,673 $ 884 $ 313 $ 18,870
Allowance for Credit Losses on Financing Receivables	The balance in the allowance for loan losses and the recorded investment in loans by portfolio segment and based on impairment method is presented in the following table as of September 30, 2018 and December 31, 2017 . September 30, 2018 Commercial Residential Consumer Total (in thousands) Allowance for loan losses: Ending allowance balance attributable to loans Individually evaluated for impairment $ 257 $ — $ — $ 257 Collectively evaluated for impairment 18,995 827 271 20,093 PCI — 93 — 93 Total ending allowance balance $ 19,252 $ 920 $ 271 $ 20,443 Loans: Loans individually evaluated for impairment $ 10,633 $ 192 $ — $ 10,825 Loans collectively evaluated for impairment 1,795,176 174,093 54,929 2,024,198 PCI 4,213 2,084 10 6,307 Total ending loans balance $ 1,810,022 $ 176,369 $ 54,939 $ 2,041,330 December 31, 2017 Commercial Residential Consumer Total (in thousands) Allowance for loan losses: Ending allowance balance attributable to loans Individually evaluated for impairment $ 306 $ — $ — $ 306 Collectively evaluated for impairment 17,918 800 275 18,993 PCI 43 2 — 45 Total ending allowance balance $ 18,267 $ 802 $ 275 $ 19,344 Loans: Loans individually evaluated for impairment $ 6,886 $ 186 $ — $ 7,072 Loans collectively evaluated for impairment 1,694,948 178,204 45,671 1,918,823 PCI 9,416 2,338 — 11,754 Total ending loans balance $ 1,711,250 $ 180,728 $ 45,671 $ 1,937,649
Impaired Financing Receivables	The following table presents information on Atlantic Capital’s impaired loans for the three and nine months ended September 30, 2018 and 2017 : For the Three Months Ended September 30, 2018 2017 Unpaid Principal Balance Recorded Investment Related Allowance Average Balance of Recorded Investment While Impaired Interest Income Recognized During Impairment Unpaid Principal Balance Recorded Investment Related Allowance Average Balance of Recorded Investment While Impaired Interest Income Recognized During Impairment (in thousands) Impaired loans with no related allowance recorded: Commercial and industrial $ 4,455 $ 4,455 $ — $ 4,488 $ 57 $ 2,424 $ 2,361 $ — $ 2,287 $ 14 Commercial real estate 1,725 1,562 — 1,569 — 1,946 1,783 — 1,889 — Construction and land — — — — — — — — — — Residential mortgages 237 192 — 201 1 236 190 — 191 — Home equity — — — — — 529 529 — 531 — Mortgage warehouse — — — — — — — — — — Consumer — — — — — — — — — — Total $ 6,417 $ 6,209 $ — $ 6,258 $ 58 $ 5,135 $ 4,863 $ — $ 4,898 $ 14 Impaired loans with an allowance recorded: Commercial and industrial $ — $ — $ — $ — $ — $ 4,333 $ 4,333 $ 356 $ 4,375 $ 49 Commercial real estate 4,616 4,616 257 4,616 — 572 572 134 576 6 Construction and land — — — — — — — — — — Residential mortgages — — — — — — — — — — Home equity — — — — — — — — — — Mortgage warehouse — — — — — — — — — — Consumer — — — — — — — — — — Total $ 4,616 $ 4,616 $ 257 $ 4,616 $ — $ 4,905 $ 4,905 $ 490 $ 4,951 $ 55 Total impaired loans $ 11,033 $ 10,825 $ 257 $ 10,874 $ 58 $ 10,040 $ 9,768 $ 490 $ 9,849 $ 69 For the Nine Months Ended September 30, 2018 2017 Unpaid Principal Balance Recorded Investment Related Allowance Average Balance of Recorded Investment While Impaired Interest Income Recognized During Impairment Unpaid Principal Balance Recorded Investment Related Allowance Average Balance of Recorded Investment While Impaired Interest Income Recognized During Impairment (in thousands) Impaired loans with no related allowance recorded: Commercial and industrial $ 4,455 $ 4,455 $ — $ 4,584 $ 173 $ 2,424 $ 2,361 $ — $ 2,717 $ 42 Commercial real estate 1,725 1,562 — 1,577 — 1,946 1,783 — 1,925 1 Construction and land — — — — — — — — — — Residential mortgages 237 192 — 203 2 236 190 — 221 — Home equity — — — — — 529 529 — 264 — Mortgage warehouse — — — — — — — — — — Consumer — — — — — — — — — — Total $ 6,417 $ 6,209 $ — $ 6,364 $ 175 $ 5,135 $ 4,863 $ — $ 5,127 $ 43 Impaired loans with an allowance recorded: Commercial and industrial $ — $ — $ — $ — $ — $ 4,333 $ 4,333 $ 356 $ 4,454 $ 149 Commercial real estate 4,616 4,616 257 4,616 — 572 572 134 581 19 Construction and land — — — — — — — — — — Residential mortgages — — — — — — — — — — Home equity — — — — — — — — — — Mortgage warehouse — — — — — — — — — — Consumer — — — — — — — — — — Total $ 4,616 $ 4,616 $ 257 $ 4,616 $ — $ 4,905 $ 4,905 $ 490 $ 5,035 $ 168 Total impaired loans $ 11,033 $ 10,825 $ 257 $ 10,980 $ 175 $ 10,040 $ 9,768 $ 490 $ 10,162 $ 211
Troubled Debt Restructurings on Financing Receivables	As of September 30, 2018 and December 31, 2017 , and based on the most recent analysis performed, the risk category of loans by class of loans is as follows. Pass Special Mention Substandard Accruing Substandard Nonaccruing Doubtful Total (in thousands) September 30, 2018 Commercial and industrial $ 622,599 $ 3,157 $ 21,221 $ 318 $ — $ 647,295 Commercial real estate 952,182 2,079 15,327 — 1,562 971,150 Construction and land 159,505 21 — — — 159,526 Residential mortgages 105,232 1,178 859 315 289 107,873 Home equity 66,002 — 353 57 — 66,412 Mortgage warehouse 27,838 — — — — 27,838 Consumer/Other 54,677 19 58 175 — 54,929 Total loans, excluding PCI loans $ 1,988,035 $ 6,454 $ 37,818 $ 865 $ 1,851 $ 2,035,023 Commercial and industrial $ — $ — $ 1,054 $ — $ — $ 1,054 Commercial real estate 2,370 427 — — 107 2,904 Construction and land 243 5 7 — — 255 Residential mortgages 631 325 693 — — 1,649 Home equity 195 74 166 — — 435 Mortgage warehouse — — — — — — Consumer/Other — — 10 — — 10 Total PCI loans $ 3,439 $ 831 $ 1,930 $ — $ 107 $ 6,307 Pass Special Mention Substandard Accruing Substandard Nonaccruing Doubtful Total (in thousands) December 31, 2017 Commercial and industrial $ 572,942 $ 15,643 $ 21,332 $ 16 $ 2 $ 609,935 Commercial real estate 919,939 6,227 8,906 — 1,592 936,664 Construction and land 115,255 — — — — 115,255 Residential mortgages 100,342 1,075 753 398 321 102,889 Home equity 74,841 64 310 285 — 75,500 Mortgage warehouse 39,981 — — — — 39,981 Consumer/Other 45,422 57 192 — — 45,671 Total loans, excluding PCI loans $ 1,868,722 $ 23,066 $ 31,493 $ 699 $ 1,915 $ 1,925,895 Commercial and industrial $ — $ 3,881 $ 1,543 $ — $ — $ 5,424 Commercial real estate 3,151 212 276 — 112 3,751 Construction and land 222 7 11 — — 240 Residential mortgages 428 493 674 — — 1,595 Home equity 34 354 356 — — 744 Mortgage warehouse — — — — — — Consumer/Other — — — — — — Total PCI loans $ 3,835 $ 4,947 $ 2,860 $ — $ 112 $ 11,754
Past Due Financing Receivables	The following table presents the aging of the recorded investment in past due loans as of September 30, 2018 and December 31, 2017 by class of loans. As of September 30, 2018 Accruing Current Accruing 30-89 Days Past Due Accruing 90+ Days Past Due Nonaccruing PCI Loans Total (in thousands) Loans by Classification Commercial and industrial $ 646,461 $ 516 $ — $ 318 $ 1,054 $ 648,349 Commercial real estate 969,116 472 — 1,562 2,904 974,054 Construction and land 159,518 8 — — 255 159,781 Residential mortgages 106,343 926 — 604 1,649 109,522 Home equity 66,131 224 — 57 435 66,847 Mortgage warehouse 27,838 — — — — 27,838 Consumer 54,747 7 — 175 10 54,939 Total Loans $ 2,030,154 $ 2,153 $ — $ 2,716 $ 6,307 $ 2,041,330 As of December 31, 2017 Accruing Current Accruing 30-89 Days Past Due Accruing 90+ Days Past Due Nonaccruing PCI Loans Total (in thousands) Loans by Classification Commercial and industrial $ 606,677 $ 3,239 $ — $ 19 $ 5,424 $ 615,359 Commercial real estate 932,916 2,156 — 1,592 3,751 940,415 Construction and land 114,988 267 — — 240 115,495 Residential mortgages 100,402 1,470 298 719 1,595 104,484 Home equity 75,081 135 — 284 744 76,244 Mortgage warehouse 39,981 — — — — 39,981 Consumer 45,599 72 — — — 45,671 Total Loans $ 1,915,644 $ 7,339 $ 298 $ 2,614 $ 11,754 $ 1,937,649

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets and Goodwill	The carrying amount of goodwill and other intangible assets as of September 30, 2018 and December 31, 2017 is summarized below: September 30, December 31, 2018 2017 (in thousands) Core deposit intangible $ 9,544 $ 9,544 Less: accumulated amortization (5,582 ) (4,624 ) Less: impairment related to divested branches (2,286 ) (2,286 ) Core deposit intangible, net 1,676 2,634 Servicing assets, net 3,191 3,240 Total other intangibles, net 4,867 5,874 Goodwill 21,690 21,759 Total goodwill and other intangible assets, net $ 26,557 $ 27,633 The following table presents activity for goodwill and other intangible assets: For the Three Months Ended September 30, For the Nine Months Ended September 30, Goodwill Core Deposit Intangible Total Goodwill Core Deposit Intangible Total (in thousands) 2018 Balance, beginning of period $ 21,690 $ 1,972 $ 23,662 $ 21,759 $ 2,634 $ 24,393 Amortization — (296 ) (296 ) — (958 ) (958 ) Impairment, due to trust business sale — — — (69 ) — (69 ) Balance, end of period $ 21,690 $ 1,676 $ 23,366 $ 21,690 $ 1,676 $ 23,366 2017 Balance, beginning of period $ 21,759 $ 3,392 $ 25,151 $ 21,759 $ 4,624 $ 26,383 Amortization — (391 ) (391 ) — (1,286 ) (1,286 ) Impairment, due to branch divestiture — — — — (337 ) (337 ) Balance, end of period $ 21,759 $ 3,001 $ 24,760 $ 21,759 $ 3,001 $ 24,760

Servicing Assets (Tables)

Servicing Assets (Tables)	9 Months Ended
	Sep. 30, 2018
Transfers and Servicing [Abstract]
Changes in the Balance of Servicing Assets	Changes in the balance of servicing assets for the three and nine months ended September 30, 2018 and 2017 are presented in the following table . Three months ended September 30, Nine months ended September 30, SBA Loan Servicing Assets 2018 2017 2018 2017 (in thousands) Beginning carrying value, net $ 2,827 $ 2,564 $ 2,635 $ 2,359 Additions 120 157 739 750 Amortization (239 ) (221 ) (666 ) (609 ) Impairment — — — — Ending carrying value $ 2,708 $ 2,500 $ 2,708 $ 2,500 Changes in the balance of TriNet servicing assets for the three and nine months ended September 30, 2018 and 2017 are presented in the following table. Three months ended September 30, Nine months ended September 30, TriNet Servicing Assets 2018 2017 2018 2017 (in thousands) Beginning carrying value, net $ 523 $ 731 $ 605 $ 825 Additions — — — — Amortization (40 ) (46 ) (122 ) (140 ) Impairment — — — — Ending carrying value $ 483 $ 685 $ 483 $ 685
Schedule of Sensitivity to Immediate Changes in Key Economic Assumptions	At September 30, 2018 and December 31, 2017 , the sensitivity of the fair value of the SBA loan servicing assets to immediate changes in key economic assumptions are presented in the table below . Sensitivity of the SBA Servicing Assets September 30, 2018 December 31, 2017 (dollars in thousands) Fair value of retained servicing assets $ 2,731 $ 2,865 Weighted average life 5.10 years 6.22 years Prepayment speed: 11.06 % 8.64 % Decline in fair value due to a 10% adverse change $ (123 ) $ (103 ) Decline in fair value due to a 20% adverse change $ (214 ) $ (181 ) Weighted average discount rate 15.72 % 13.01 % Decline in fair value due to a 100 bps adverse change $ (99 ) $ (103 ) Decline in fair value due to a 200 bps adverse change $ (167 ) $ (180 ) At September 30, 2018 and December 31, 2017 , the sensitivity of the fair value of the TriNet servicing assets to immediate changes in key economic assumptions are presented in the table below . Sensitivity of the TriNet Servicing Assets September 30, 2018 December 31, 2017 (dollars in thousands) Fair value of retained servicing assets $ 565 $ 697 Weighted average life 7.34 years 7.37 years Prepayment speed: 5.00 % 5.00 % Decline in fair value due to a 10% adverse change $ (8 ) $ (10 ) Decline in fair value due to a 20% adverse change $ (15 ) $ (20 ) Weighted average discount rate 8.00 % 8.00 % Decline in fair value due to a 100 bps adverse change $ (14 ) $ (19 ) Decline in fair value due to a 200 bps adverse change $ (27 ) $ (37 )

Other Comprehensive Income (L_2

Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following tables present a summary of the changes in accumulated other comprehensive income (loss) balances for the applicable periods. For the Three Months Ended For the Nine Months Ended September 30, 2018 September 30, 2018 Pre-Tax Amount Income Tax (Expense) Benefit After-Tax Amount Pre-Tax Amount Income Tax (Expense) Benefit After-Tax Amount (in thousands) Accumulated other comprehensive income (loss) beginning of period $ (19,825 ) $ 4,958 $ (14,867 ) $ (6,274 ) $ 2,415 $ (3,859 ) Reclassification of tax effects from AOCI — — — — (844 ) (844 ) Unrealized net gains (losses) on investment securities available-for-sale (4,160 ) 1,041 (3,119 ) (15,097 ) 3,775 (11,322 ) Reclassification adjustment for net realized losses on investment securities available-for-sale — — — 2 (1 ) 1 Unrealized net gains (losses) on derivatives (579 ) 145 (434 ) (3,195 ) 799 (2,396 ) Accumulated other comprehensive income (loss) end of period $ (24,564 ) $ 6,144 $ (18,420 ) $ (24,564 ) $ 6,144 $ (18,420 ) For the Three Months Ended For the Nine Months Ended September 30, 2017 September 30, 2017 Pre-Tax Amount Income Tax (Expense) Benefit After-Tax Amount Pre-Tax Amount Income Tax (Expense) Benefit After-Tax Amount (in thousands) Accumulated other comprehensive income (loss) beginning of period $ (3,690 ) $ 1,420 $ (2,270 ) $ (9,144 ) $ 3,519 $ (5,625 ) Unrealized net gains (losses) on investment securities available-for-sale 706 (272 ) 434 6,366 (2,450 ) 3,916 Reclassification adjustment for net realized losses on investment securities available-for-sale 80 (31 ) 49 80 (31 ) 49 Unrealized net gains (losses) on derivatives (121 ) 46 (75 ) (327 ) 125 (202 ) Accumulated other comprehensive income (loss) end of period $ (3,025 ) $ 1,163 $ (1,862 ) $ (3,025 ) $ 1,163 $ (1,862 )

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Schedule of Calculation of Numerator and Denominator in Earnings Per Share	The following table represents the earnings per share calculations for the three and nine months ended September 30, 2018 and 2017 . Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 (in thousands, except share and per share amounts) Net income available to common shareholders $ 6,513 $ 4,052 $ 19,702 $ 11,611 Weighted average shares outstanding Basic (1) 26,103,397 25,699,179 25,956,336 25,548,646 Effect of dilutive securities: Stock options, warrants and performance share awards 151,375 191,600 178,319 251,205 Diluted 26,254,772 25,890,779 26,134,655 25,799,851 Income per common share: Basic $ 0.25 $ 0.16 $ 0.76 $ 0.45 Diluted $ 0.25 $ 0.16 $ 0.75 $ 0.45 (1) Unvested restricted shares are participating securities and included in basic share calculations.

Derivatives and Hedging (Tables

Derivatives and Hedging (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	The following table reflects the estimated fair value positions of derivative contracts and credit risk participation agreements as of September 30, 2018 and December 31, 2017 : Derivatives designated as hedging instruments under ASC 815 (in thousands) September 30, 2018 December 31, 2017 Interest Rate Products Balance Sheet Location Notional Amount Fair Value Notional Amount Fair Value Cash flow hedge of LIBOR based loans Other liabilities $ 100,000 $ 3,998 $ 100,000 $ 887 Derivatives not designated as hedging instruments under ASC 815 (in thousands) September 30, 2018 December 31, 2017 Interest Rate Products Balance Sheet Location Notional Amount Fair Value Notional Amount Fair Value Customer swap positions Other assets $ 55,483 $ 1,650 $ 71,160 $ 946 Zero premium collar Other assets 91,534 2,922 94,953 2,072 $ 147,017 $ 4,572 $ 166,113 $ 3,018 Dealer offsets to customer swap positions Other liabilities $ 55,483 $ 1,631 $ 71,160 $ 975 Credit risk participation Other liabilities 10,001 1 14,807 4 Dealer offset to zero premium collar Other liabilities 91,534 2,922 94,953 2,157 $ 157,018 $ 4,554 $ 180,920 $ 3,136 The following table presents the effect of the Company’s derivative financial instruments that are not designated as hedging instruments on the Consolidated Statements of Income for the three and nine months ended September 30, 2018 and 2017 . Derivatives not designated as hedging instruments under ASC 815 (in thousands) Location of Gain or (Loss) Recognized in Income on Derivative Amount of Gain or (Loss) Recognized in Income on Derivative Amount of Gain or (Loss) Recognized in Income on Derivative Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Interest rate products Other income / (expense) $ 10 $ (3 ) $ 132 $ (121 ) Other contracts Other income / (expense) — — 4 (6 ) Total $ 10 $ (3 ) $ 136 $ (127 ) Fee income Other income / (expense) $ 10 $ — $ 18 $ 189 The following table reflects the impact to the Consolidated Statements of Income related to derivative contracts for the three and nine months ended September 30, 2018 and 2017 : Derivatives in Cash Flow Hedging Relationships Three Months Ended September 30, Nine Months Ended September 30, (in thousands) Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion) Gain or (Loss) Reclassified from Accumulated OCI in Income (Effective Portion) Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion) Gain or (Loss) Reclassified from Accumulated OCI in Income (Effective Portion) 2018 2017 Location 2018 2017 2018 2017 Location 2018 2017 Interest rate swaps $ (598 ) $ (75 ) Interest income $ (18 ) $ 84 $ (3,093 ) $ (202 ) Interest income $ 103 $ 331

Other Borrowings and Long Ter_2

Other Borrowings and Long Term Debt (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments and Borrowings	Subordinated debt is summarized as follows: September 30, 2018 December 31, 2017 (in thousands) Floating rate 10 year capital securities, with interest paid semi-annually at an annual fixed rate of 6.25% until September 30, 2020 $ 50,000 $ 50,000 Principal amount of subordinated debt $ 50,000 $ 50,000 Less debt issuance costs 338 465 Subordinated debt, net $ 49,662 $ 49,535 Federal Home Loan Bank borrowings as of September 30, 2018 and December 31, 2017 are as follows: September 30, 2018 December 31, 2017 Balance Interest Rate Balance Interest Rate (in thousands) (in thousands) FHLB short-term borrowings: FHLB short-term borrowings: Fixed rate advance maturing October 1, 2018 $ 30,000 2.09 % Fixed rate advance maturing January 16, 2018 $ 45,000 1.40 % Fixed rate advance maturing October 2, 2018 53,000 2.09 % Total $ 83,000 Total $ 45,000

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation, Fair Value of Options Assumptions	The table below summarizes the assumptions used to calculate the fair value of options granted/modified during the nine months ended September 30, 2018 and 2017: For the nine months ended September 30, 2018 2017 Risk‑free interest rate 1.66 % 1.00-1.99% Expected term in years 0.25 0.25-8 Expected stock price volatility 24.2 % 23.2-25.3% Dividend yield — % — %
Schedule of Share-based Compensation, Stock Options and Warrants Activity	The following table represents stock option activity for the nine months ended September 30, 2018 : Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Outstanding, December 31, 2017 757,711 $ 12.66 Granted/modified (1) 15,000 14.64 Exercised (300,616 ) 13.32 Forfeited (1) (19,935 ) 14.08 Expired (306 ) 105.97 Outstanding, September 30, 2018 451,854 $ 11.97 4.25 $ 2,185 Exercisable, September 30, 2018 371,974 $ 11.39 3.63 $ 2,022 (1) During the nine months ended September 30, 2018, the Company modified options for 15,000 shares. The modifications are included as shares granted/modified and as shares forfeited in this table.
Schedule of Share-based Compensation, Restricted Stock Award Activity	The following table represents restricted stock and performance share award activity for the nine months ended September 30, 2018 : Shares Weighted Average Grant-Date Fair Value Outstanding, December 31, 2017 239,468 $ 15.69 Granted/modified (1) 135,757 19.89 Exercised (59,300 ) 15.16 Forfeited (1) (30,888 ) 15.97 Outstanding, September 30, 2018 285,037 $ 17.78 (1) During the nine months ended September 30, 2018, the Company modified 6,869 restricted stock awards. The modifications are included as shares granted/modified and as shares forfeited in this table.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities, Measured on Recurring Basis	The following table presents the assets that were measured at fair value on a recurring basis by level within the fair value hierarchy as reported in the Consolidated Balance Sheets at September 30, 2018 and December 31, 2017 . Fair Value Measurements at September 30, 2018 Using: Quoted Prices in Active Markets for Identical Securities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total (in thousands) Securities available-for-sale— U.S. government agencies $ — $ 35,445 $ — $ 35,445 U.S. states and political subdivisions — 82,665 — 82,665 Trust preferred securities — 4,625 — 4,625 Corporate debt securities — 12,369 — 12,369 Mortgage-backed securities — 330,652 — 330,652 Total securities available-for-sale $ — $ 465,756 $ — $ 465,756 Interest rate derivative assets $ — $ 4,572 $ — $ 4,572 Interest rate derivative liabilities $ — $ 8,552 $ — $ 8,552 Fair Value Measurements at December 31, 2017 Using: Quoted Prices in Active Markets for Identical Securities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total (in thousands) Securities available-for-sale— U.S. government agencies $ — $ 34,111 $ — $ 34,111 U.S. states and political subdivisions — 90,001 — 90,001 Trust preferred securities — 4,650 — 4,650 Corporate debt securities — 12,622 — 12,622 Mortgage-backed securities — 307,733 — 307,733 Total securities available-for-sale $ — $ 449,117 $ — $ 449,117 Interest rate derivative assets $ — $ 3,018 $ — $ 3,018 Interest rate derivative liabilities $ — $ 4,023 $ — $ 4,023
Fair Value Measurements, Nonrecurring	The following table presents the assets that were measured at fair value on a nonrecurring basis by level within the fair value hierarchy as reported in the Consolidated Balance Sheets at September 30, 2018 and December 31, 2017 . September 30, 2018 Level 1 Fair Value Measurement Level 2 Fair Value Measurement Level 3 Fair Value Measurement Total (in thousands) Impaired Loans $ — $ — $ 1,588 $ 1,588 December 31, 2017 Level 1 Fair Value Measurement Level 2 Fair Value Measurement Level 3 Fair Value Measurement Total (in thousands) Impaired Loans $ — $ — $ 2,199 $ 2,199
Fair Value Measurements, Recurring and Nonrecurring	The following table presents the estimated fair values of Atlantic Capital’s financial instruments at September 30, 2018 and December 31, 2017 . Fair Value Measurements at September 30, 2018 Using: Carrying Value Quoted Prices in Active markets for Identical Securities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) Financial assets Cash and due from banks $ 28,007 $ 28,007 $ — $ — Interest bearing deposits in banks 140,682 140,682 — — Other short-term investments 20,898 20,898 — — Total securities available-for-sale 465,756 — 465,756 — FHLB stock 6,150 — — 6,150 Federal Reserve Bank stock 9,842 — — 9,842 Loans held for investment, net 2,017,991 — — 1,963,794 Loans held for sale 1,886 — 1,886 — Derivative assets 4,572 — 4,572 — Financial liabilities Deposits $ 2,379,824 $ — $ 2,208,910 $ — Federal funds purchased and securities sold under agreements to repurchase 8,904 8,904 — — Subordinated debt 49,662 — 48,995 — FHLB advances 83,000 — 83,011 — Derivative financial instruments 8,552 — 8,552 — Fair Value Measurements at December 31, 2017 Using: Carrying Value Quoted Prices in Active markets for Identical Securities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) Financial assets Cash and due from banks $ 38,086 $ 38,086 $ — $ — Interest-bearing deposits in other banks 281,247 281,247 — — Other short-term investments 10,681 10,681 — — Total securities available-for-sale 449,117 — 449,117 — FHLB stock 4,388 — — 4,388 Federal Reserve Bank stock 9,792 — — 9,792 Loans held for investment, net 1,914,495 — — 1,955,705 Loans held for sale 1,487 — 1,487 — Derivative assets 3,018 — 3,018 — Financial liabilities Deposits $ 2,450,665 $ — $ 2,411,810 $ — Subordinated debt 49,535 — 49,888 — FHLB advances 45,000 — 45,057 — Derivative financial instruments 4,023 — 4,023 —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Exposure to Credit Risk By Commitment	Atlantic Capital’s maximum exposure to credit risk for unfunded loan commitments and standby letters of credit at September 30, 2018 and December 31, 2017 was as follows: September 30, December 31, (in thousands) Financial Instruments whose contract amount represents credit risk: Commitments to extend credit $ 717,847 $ 689,753 Standby letters of credit 13,006 10,958 $ 730,853 $ 700,711

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents service charges by type of service provided for the three and nine months ended September 30, 2018 and 2017: For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) Deposit account analysis fees and charges $ 654 $ 551 $ 1,860 $ 1,567 ATM fees 276 370 863 1,182 NSF fees 177 176 541 625 Wire fees 110 88 302 266 Foreign Exchange Fees 54 50 186 186 Other 7 12 26 44 $ 1,278 $ 1,247 $ 3,778 $ 3,870 The following table presents trust income by type of service provided for the three and nine months ended September 30, 2018 and 2017: For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 (in thousands) Personal trust and agency accounts $ — $ 259 $ 616 $ 728 Employee benefit and retirement-related trust and agency accounts — 58 120 166 Investment management and investment advisory agency accounts — 89 217 263 Custody and safekeeping accounts — 12 26 43 Other — 19 46 132 $ — $ 437 $ 1,025 $ 1,332

Accounting Standards Updates _2

Accounting Standards Updates and Recently Adopted Standards - Narrative (Details) - USD ($)	Jan. 01, 2018	Sep. 30, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of tax effects from AOCI	$ 0	$ 0
Retained earnings		33,357,000	$ 12,810,000
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of tax effects from AOCI		844,000
Accounting Standards Update 2018-02 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of tax effects from AOCI		$ 844,000
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	$ 2,000

Acquisitions and Divestitures (

Acquisitions and Divestitures (Details) - USD ($)	Dec. 14, 2017	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Business Combinations [Abstract]
Proceeds from divestiture of business	$ 1,700,000
Gain on sale of trust business		$ 0	$ 1,700,000	$ 0	$ 1,681,000	$ 0
Goodwill impairment		$ 0	$ 69,000	$ 0	$ 69,000	$ 0

Balance Sheet Offsetting (Detai

Balance Sheet Offsetting (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Offsetting Securities Purchased under Agreements to Resell [Abstract]
Reverse repurchase agreements, Gross amounts of recognized assets	$ 20,898	$ 10,681
Reverse repurchase agreements, Gross amounts offset on the Balance Sheet	0	0
Reversed repurchase agreements, Net asset balance	20,898	10,681
Reverse repurchase agreements, Financial instruments	(20,898)	(10,681)
Reverse repurchase agreements, Cash collateral received	0	0
Reverse repurchase agreements, Net amount	0	0
Offsetting Derivative Assets [Abstract]
Derivatives, Gross amounts of recognized assets	4,572	3,018
Derivatives, Gross amounts offset on the Balance Sheet	0	0
Derivatives, Net asset balance	4,572	3,018
Derivatives, Financial instruments	0	0
Derivatives, Cash collateral received	0	0
Derivatives, Net amount	4,572	3,018
Offsetting Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed [Abstract]
Total, Gross amounts of recognized assets	25,470	13,699
Total, Gross amounts offset on the Balance Sheet	0	0
Total, Net asset balance	25,470	13,699
Total, Financial instruments	(20,898)	(10,681)
Total, Cash Cash collateral received	0	0
Total, Net amount	4,572	3,018
Offsetting Securities Sold under Agreements to Repurchase [Abstract]
Repurchase agreements, Gross amounts of recognized liability	8,904	0
Repurchase agreements, Gross amounts offset on the Balance Sheet	0	0
Repurchase agreements, Net liability balance	8,904	0
Repurchase agreements, Financial instruments	(10,828)	0
Repurchase agreements, Cash collateral pledged	0	0
Repurchase agreements, Net amount	0	0
Offsetting Derivative Liabilities [Abstract]
Derivative, Gross amounts of recognized liability	8,552	4,023
Derivatives, Gross amounts offset on the Balance Sheet	0	0
Derivative, Net liability balance	8,552	4,023
Derivatives, Financial instruments	(7,226)	(2,705)
Derivatives, Cash collateral pledged	(1,326)	(1,318)
Derivatives, Net amount	0	0
Offsetting Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned [Abstract]
Total, Gross amounts of recognized liability	17,456	4,023
Total, Gross amounts offset on the Balance Sheet	0	0
Total, Net liability balance	17,456	4,023
Total, Financial instruments	(18,054)	(2,705)
Total, Cash collateral pledged	(1,326)	(1,318)
Total, Net amount	$ 0	$ 0

Securities (Securities Availabl

Securities (Securities Available-For-Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	$ 486,434	$ 454,699
Gross Unrealized Gains	2,429	2,731
Gross Unrealized Losses	(23,107)	(8,313)
Securities available-for-sale	465,756	449,117
U.S. Government agencies
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	36,708	34,699
Gross Unrealized Gains	0	11
Gross Unrealized Losses	(1,263)	(599)
Securities available-for-sale	35,445	34,111
U.S. states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	91,656	92,169
Gross Unrealized Gains	2	237
Gross Unrealized Losses	(8,993)	(2,405)
Securities available-for-sale	82,665	90,001
Trust preferred securities
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	4,774	4,754
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(149)	(104)
Securities available-for-sale	4,625	4,650
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	12,879	12,948
Gross Unrealized Gains	0	60
Gross Unrealized Losses	(510)	(386)
Securities available-for-sale	12,369	12,622
Residential mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Total amortized cost	340,417	310,129
Gross Unrealized Gains	2,427	2,423
Gross Unrealized Losses	(12,192)	(4,819)
Securities available-for-sale	$ 330,652	$ 307,733

Securities (Maturities) (Detail

Securities (Maturities) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Amortized Cost
Within 1 year	$ 246
Over 1 year through 5 years	30,299
5 years to 10 years	47,062
Over 10 years	68,410
Total with Single Maturity Date	146,017
Residential mortgage-backed securities	340,417
Total amortized cost	486,434	$ 454,699
Fair Value
Within 1 year	245
Over 1 year through 5 years	29,151
5 years to 10 years	45,326
Over 10 years	60,382
Total with Single Maturity Date	135,104
Residential mortgage-backed securities	330,652
Total fair value	$ 465,756	$ 449,117

Securities (Unrealized Losses -

Securities (Unrealized Losses - Available-For-Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 179,475	$ 194,783
12 months or greater, fair value	272,609	202,089
Total fair value	452,084	396,872
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months, unrealized losses	(5,125)	(1,902)
12 months or greater, unrealized losses	(17,982)	(6,411)
Total unrealized losses	(23,107)	(8,313)
U.S. Government agencies
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	11,983	22,148
12 months or greater, fair value	23,462	9,145
Total fair value	35,445	31,293
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months, unrealized losses	(310)	(348)
12 months or greater, unrealized losses	(952)	(251)
Total unrealized losses	(1,262)	(599)
U.S. states and political divisions
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	22,182	14,009
12 months or greater, fair value	59,978	58,744
Total fair value	82,160	72,753
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months, unrealized losses	(1,301)	(183)
12 months or greater, unrealized losses	(7,693)	(2,222)
Total unrealized losses	(8,994)	(2,405)
Trust preferred securities
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	4,625	0
12 months or greater, fair value	0	4,650
Total fair value	4,625	4,650
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months, unrealized losses	(149)	0
12 months or greater, unrealized losses	0	(104)
Total unrealized losses	(149)	(104)
Corporate debt securities
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	7,446	2,989
12 months or greater, fair value	4,922	2,970
Total fair value	12,368	5,959
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months, unrealized losses	(141)	(27)
12 months or greater, unrealized losses	(369)	(359)
Total unrealized losses	(510)	(386)
Residential mortgage-backed securities
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	133,239	155,637
12 months or greater, fair value	184,247	126,580
Total fair value	317,486	282,217
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months, unrealized losses	(3,224)	(1,344)
12 months or greater, unrealized losses	(8,968)	(3,475)
Total unrealized losses	$ (12,192)	$ (4,819)

Securities (Narrative) (Details

Securities (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)security	Jun. 30, 2018USD ($)	Sep. 30, 2018USD ($)security	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities in unrealized loss positions (security) | security	337		337
Impairment changes on securities available-for-sale	$ 0		$ 0	$ 0
Investment securities pledged to secure borrowings	70,600,000		70,600,000		$ 93,900,000
Securities available-for-sale	465,756,000		465,756,000		$ 449,117,000
Impairment loss on SBICs			228,000	$ 0
SBIC Investments
Debt Securities, Available-for-sale [Line Items]
Securities available-for-sale	$ 4,100,000		4,100,000
Impairment loss on SBICs		$ 228,000	$ 228,000

Securities (Realized Gains (Los

Securities (Realized Gains (Losses) - Available-For-Sale) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales	$ 0	$ 1,813	$ 24	$ 1,813
Gross realized gains	0	0	0	0
Gross realized losses	0	(80)	(2)	(80)
Net losses on sales of securities	$ 0	$ (80)	$ (2)	$ (80)

Loans and Allowance for Loan _3

Loans and Allowance for Loan Losses (Summary of Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other loans held for sale	$ 1,886		$ 1,487
Total loans held for sale	1,886		1,487
Loans	2,041,330		1,937,649
Less net deferred fees and other unearned income	(2,896)		(3,810)
Less allowance for loan losses	(20,443)	$ (19,583)	(19,344)	$ (18,870)	$ (21,870)	$ (20,595)
Loans held for investment, net	2,017,991		1,914,495
Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	109,522		104,484
Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	66,847		76,244
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	21,399		16,278
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,810,022		1,711,250
Less allowance for loan losses	(19,252)	(18,491)	(18,267)	(17,673)	(20,692)	(18,717)
Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	648,349		615,359
Commercial | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	974,054		940,415
Commercial | Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	159,781		115,495
Commercial | Mortgage warehouse participations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	27,838		39,981
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	176,369		180,728
Less allowance for loan losses	(920)	(811)	(802)	(884)	(860)	(1,418)
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	33,540		29,393
Less allowance for loan losses	$ (271)	$ (281)	$ (275)	$ (313)	$ (318)	$ (460)

Loans and Allowance for Loan _4

Loans and Allowance for Loan Losses (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans pledged as collateral	$ 720,500	$ 667,200
Carrying value of loans	2,041,330	1,937,649
Accretable yield	2,200	2,800
Troubled debt restructurings	9,100	5,300
PCI Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of loans	6,307	11,754
Loans receivable	8,300	14,100
Commercial and industrial | PCI Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of loans	1,054	5,424
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of loans	1,810,022	1,711,250
Commercial | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Additional loan amounts	18	26
Charge off and reclassification of remaining TDR balance	980
Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of loans	648,349	615,359
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of loans	176,369	180,728
Residential | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of loans	66,847	76,244
Residential | Home equity | PCI Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of loans	$ 435	$ 744

Loans and Allowance for Loan _5

Loans and Allowance for Loan Losses (Accretable Yield Movement) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 2,456	$ 3,130	$ 2,316	$ 3,467
Accretion	(299)	(427)	(898)	(1,206)
Reclassification of nonaccretable discount due to change in expected cash flows	180	(202)	473	142
Other changes, net	96	281	542	379
Balance at end of period	$ 2,433	$ 2,782	$ 2,433	$ 2,782

Loans and Allowance for Loan _6

Loans and Allowance for Loan Losses (Allowance Rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 19,583	$ 21,870	$ 19,344	$ 20,595
Provision for loan losses	845	322	1,444	2,936
Loans charged-off	0	(3,346)	(419)	(4,702)
Recoveries	15	24	74	41
Total ending allowance balance	20,443	18,870	20,443	18,870
Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	18,491	20,692	18,267	18,717
Provision for loan losses	761	273	1,115	3,152
Loans charged-off	0	(3,308)	(176)	(4,221)
Recoveries	0	16	46	25
Total ending allowance balance	19,252	17,673	19,252	17,673
Residential
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	811	860	802	1,418
Provision for loan losses	109	55	348	(451)
Loans charged-off	0	(31)	(230)	(85)
Recoveries	0	0	0	2
Total ending allowance balance	920	884	920	884
Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	281	318	275	460
Provision for loan losses	(25)	(6)	(19)	235
Loans charged-off	0	(7)	(13)	(396)
Recoveries	15	8	28	14
Total ending allowance balance	$ 271	$ 313	$ 271	$ 313

Loans and Allowance for Loan _7

Loans and Allowance for Loan Losses (Allowance Additional Information) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Individually evaluated for impairment	$ 257	$ 306
Allowance for loan losses, Collectively evaluated for impairment	20,093	18,993
Allowance for loan losses, PCI	93	45
Allowance for loan losses, Total ending allowance balance	20,443	19,344
Loans, Individually evaluated for impairment	10,825	7,072
Loans, Collectively evaluated for impairment	2,024,198	1,918,823
Loans, PCI	6,307	11,754
Loans, Total ending allowance balance	2,041,330	1,937,649
Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Individually evaluated for impairment	257	306
Allowance for loan losses, Collectively evaluated for impairment	18,995	17,918
Allowance for loan losses, PCI	0	43
Allowance for loan losses, Total ending allowance balance	19,252	18,267
Loans, Individually evaluated for impairment	10,633	6,886
Loans, Collectively evaluated for impairment	1,795,176	1,694,948
Loans, PCI	4,213	9,416
Loans, Total ending allowance balance	1,810,022	1,711,250
Residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Individually evaluated for impairment	0	0
Allowance for loan losses, Collectively evaluated for impairment	827	800
Allowance for loan losses, PCI	93	2
Allowance for loan losses, Total ending allowance balance	920	802
Loans, Individually evaluated for impairment	192	186
Loans, Collectively evaluated for impairment	174,093	178,204
Loans, PCI	2,084	2,338
Loans, Total ending allowance balance	176,369	180,728
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Individually evaluated for impairment	0	0
Allowance for loan losses, Collectively evaluated for impairment	271	275
Allowance for loan losses, PCI	0	0
Allowance for loan losses, Total ending allowance balance	271	275
Loans, Individually evaluated for impairment	0	0
Loans, Collectively evaluated for impairment	54,929	45,671
Loans, PCI	10	0
Loans, Total ending allowance balance	$ 54,939	$ 45,671

Loans and Allowance for Loan _8

Loans and Allowance for Loan Losses (Impaired Loans) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with no related allowance recorded, Unpaid principal balance	$ 6,417	$ 5,135	$ 6,417	$ 5,135
Impaired loans with an allowance recorded, Unpaid principal balance	4,616	4,905	4,616	4,905
Total impaired loans, Unpaid principal balance	11,033	10,040	11,033	10,040
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Recorded investment	6,209	4,863	6,209	4,863
Impaired loans with an allowance recorded, Recorded investment	4,616	4,905	4,616	4,905
Total impaired loans, Recorded investment	10,825	9,768	10,825	9,768
Impaired loans with an allowance recorded, Related allowance	257	490	257	490
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Average balance of recorded investment while impaired	6,258	4,898	6,364	5,127
Impaired loans with an allowance recorded, Average balance of recorded investment while impaired	4,616	4,951	4,616	5,035
Total impaired loans, Average balance of recorded investment while impaired	10,874	9,849	10,980	10,162
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with no related allowance recorded, Interest income recognized during impairment	58	14	175	43
Impaired loans with an allowance recorded, Interest income recognized during impairment	0	55	0	168
Total impaired loans, Interest income recognized during impairment	58	69	175	211
Commercial | Commercial and industrial
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with no related allowance recorded, Unpaid principal balance	4,455	2,424	4,455	2,424
Impaired loans with an allowance recorded, Unpaid principal balance	0	4,333	0	4,333
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Recorded investment	4,455	2,361	4,455	2,361
Impaired loans with an allowance recorded, Recorded investment	0	4,333	0	4,333
Impaired loans with an allowance recorded, Related allowance	0	356	0	356
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Average balance of recorded investment while impaired	4,488	2,287	4,584	2,717
Impaired loans with an allowance recorded, Average balance of recorded investment while impaired	0	4,375	0	4,454
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with no related allowance recorded, Interest income recognized during impairment	57	14	173	42
Impaired loans with an allowance recorded, Interest income recognized during impairment	0	49	0	149
Commercial | Commercial real estate
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with no related allowance recorded, Unpaid principal balance	1,725	1,946	1,725	1,946
Impaired loans with an allowance recorded, Unpaid principal balance	4,616	572	4,616	572
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Recorded investment	1,562	1,783	1,562	1,783
Impaired loans with an allowance recorded, Recorded investment	4,616	572	4,616	572
Impaired loans with an allowance recorded, Related allowance	257	134	257	134
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Average balance of recorded investment while impaired	1,569	1,889	1,577	1,925
Impaired loans with an allowance recorded, Average balance of recorded investment while impaired	4,616	576	4,616	581
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with no related allowance recorded, Interest income recognized during impairment	0	0	0	1
Impaired loans with an allowance recorded, Interest income recognized during impairment	0	6	0	19
Commercial | Construction and land
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with no related allowance recorded, Unpaid principal balance	0	0	0	0
Impaired loans with an allowance recorded, Unpaid principal balance	0	0	0	0
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Recorded investment	0	0	0	0
Impaired loans with an allowance recorded, Recorded investment	0	0	0	0
Impaired loans with an allowance recorded, Related allowance	0	0	0	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Average balance of recorded investment while impaired	0	0	0	0
Impaired loans with an allowance recorded, Average balance of recorded investment while impaired	0	0	0	0
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with no related allowance recorded, Interest income recognized during impairment	0	0	0	0
Impaired loans with an allowance recorded, Interest income recognized during impairment	0	0	0	0
Commercial | Mortgage warehouse participations
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with no related allowance recorded, Unpaid principal balance	0	0	0	0
Impaired loans with an allowance recorded, Unpaid principal balance	0	0	0	0
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Recorded investment	0	0	0	0
Impaired loans with an allowance recorded, Recorded investment	0	0	0	0
Impaired loans with an allowance recorded, Related allowance	0	0	0	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Average balance of recorded investment while impaired	0	0	0	0
Impaired loans with an allowance recorded, Average balance of recorded investment while impaired	0	0	0	0
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with no related allowance recorded, Interest income recognized during impairment	0	0	0	0
Impaired loans with an allowance recorded, Interest income recognized during impairment	0	0	0	0
Residential | Residential mortgages
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with no related allowance recorded, Unpaid principal balance	237	236	237	236
Impaired loans with an allowance recorded, Unpaid principal balance	0	0	0	0
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Recorded investment	192	190	192	190
Impaired loans with an allowance recorded, Recorded investment	0	0	0	0
Impaired loans with an allowance recorded, Related allowance	0	0	0	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Average balance of recorded investment while impaired	201	191	203	221
Impaired loans with an allowance recorded, Average balance of recorded investment while impaired	0	0	0	0
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with no related allowance recorded, Interest income recognized during impairment	1	0	2	0
Impaired loans with an allowance recorded, Interest income recognized during impairment	0	0	0	0
Residential | Home equity
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with no related allowance recorded, Unpaid principal balance	0	529	0	529
Impaired loans with an allowance recorded, Unpaid principal balance	0	0	0	0
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Recorded investment	0	529	0	529
Impaired loans with an allowance recorded, Recorded investment	0	0	0	0
Impaired loans with an allowance recorded, Related allowance	0	0	0	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Average balance of recorded investment while impaired	0	531	0	264
Impaired loans with an allowance recorded, Average balance of recorded investment while impaired	0	0	0	0
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with no related allowance recorded, Interest income recognized during impairment	0	0	0	0
Impaired loans with an allowance recorded, Interest income recognized during impairment	0	0	0	0
Consumer
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with no related allowance recorded, Unpaid principal balance	0	0	0	0
Impaired loans with an allowance recorded, Unpaid principal balance	0	0	0	0
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Recorded investment	0	0	0	0
Impaired loans with an allowance recorded, Recorded investment	0	0	0	0
Impaired loans with an allowance recorded, Related allowance	0	0	0	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with no related allowance recorded, Average balance of recorded investment while impaired	0	0	0	0
Impaired loans with an allowance recorded, Average balance of recorded investment while impaired	0	0	0	0
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with no related allowance recorded, Interest income recognized during impairment	0	0	0	0
Impaired loans with an allowance recorded, Interest income recognized during impairment	$ 0	$ 0	$ 0	$ 0

Loans and Allowance for Loan _9

Loans and Allowance for Loan Losses (Risk Category of Loan by Class of Loan) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	$ 2,041,330	$ 1,937,649
Non-PCI Loans
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	2,035,023	1,925,895
Non-PCI Loans | Pass
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	1,988,035	1,868,722
Non-PCI Loans | Special Mention
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	6,454	23,066
Non-PCI Loans | Substandard | Accruing Loans
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	37,818	31,493
Non-PCI Loans | Substandard | Nonaccruing Loans
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	865	699
Non-PCI Loans | Doubtful | Nonaccruing Loans
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	1,851	1,915
PCI Loans
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	6,307	11,754
PCI Loans | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	1,054	5,424
PCI Loans | Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	2,904	3,751
PCI Loans | Construction and land
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	255	240
PCI Loans | Pass
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	3,439	3,835
PCI Loans | Pass | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
PCI Loans | Pass | Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	2,370	3,151
PCI Loans | Pass | Construction and land
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	243	222
PCI Loans | Special Mention
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	831	4,947
PCI Loans | Special Mention | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	3,881
PCI Loans | Special Mention | Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	427	212
PCI Loans | Special Mention | Construction and land
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	5	7
PCI Loans | Substandard | Accruing Loans
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	1,930	2,860
PCI Loans | Substandard | Accruing Loans | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	1,054	1,543
PCI Loans | Substandard | Accruing Loans | Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	276
PCI Loans | Substandard | Accruing Loans | Construction and land
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	7	11
PCI Loans | Substandard | Nonaccruing Loans
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
PCI Loans | Substandard | Nonaccruing Loans | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
PCI Loans | Substandard | Nonaccruing Loans | Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
PCI Loans | Substandard | Nonaccruing Loans | Construction and land
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
PCI Loans | Doubtful | Nonaccruing Loans
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	107	112
PCI Loans | Doubtful | Nonaccruing Loans | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
PCI Loans | Doubtful | Nonaccruing Loans | Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	107	112
PCI Loans | Doubtful | Nonaccruing Loans | Construction and land
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	1,810,022	1,711,250
Commercial | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	648,349	615,359
Commercial | Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	974,054	940,415
Commercial | Construction and land
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	159,781	115,495
Commercial | Mortgage warehouse participations
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	27,838	39,981
Commercial | Non-PCI Loans | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	647,295	609,935
Commercial | Non-PCI Loans | Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	971,150	936,664
Commercial | Non-PCI Loans | Construction and land
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	159,526	115,255
Commercial | Non-PCI Loans | Mortgage warehouse participations
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	27,838	39,981
Commercial | Non-PCI Loans | Pass | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	622,599	572,942
Commercial | Non-PCI Loans | Pass | Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	952,182	919,939
Commercial | Non-PCI Loans | Pass | Construction and land
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	159,505	115,255
Commercial | Non-PCI Loans | Pass | Mortgage warehouse participations
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	27,838	39,981
Commercial | Non-PCI Loans | Special Mention | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	3,157	15,643
Commercial | Non-PCI Loans | Special Mention | Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	2,079	6,227
Commercial | Non-PCI Loans | Special Mention | Construction and land
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	21	0
Commercial | Non-PCI Loans | Special Mention | Mortgage warehouse participations
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial | Non-PCI Loans | Substandard | Accruing Loans | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	21,221	21,332
Commercial | Non-PCI Loans | Substandard | Accruing Loans | Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	15,327	8,906
Commercial | Non-PCI Loans | Substandard | Accruing Loans | Construction and land
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial | Non-PCI Loans | Substandard | Accruing Loans | Mortgage warehouse participations
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial | Non-PCI Loans | Substandard | Nonaccruing Loans | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	318	16
Commercial | Non-PCI Loans | Substandard | Nonaccruing Loans | Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial | Non-PCI Loans | Substandard | Nonaccruing Loans | Construction and land
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial | Non-PCI Loans | Substandard | Nonaccruing Loans | Mortgage warehouse participations
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial | Non-PCI Loans | Doubtful | Nonaccruing Loans | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	2
Commercial | Non-PCI Loans | Doubtful | Nonaccruing Loans | Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	1,562	1,592
Commercial | Non-PCI Loans | Doubtful | Nonaccruing Loans | Construction and land
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial | Non-PCI Loans | Doubtful | Nonaccruing Loans | Mortgage warehouse participations
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial | PCI Loans | Mortgage warehouse participations
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial | PCI Loans | Pass | Mortgage warehouse participations
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial | PCI Loans | Special Mention | Mortgage warehouse participations
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial | PCI Loans | Substandard | Accruing Loans | Mortgage warehouse participations
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial | PCI Loans | Substandard | Nonaccruing Loans | Mortgage warehouse participations
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Commercial | PCI Loans | Doubtful | Nonaccruing Loans | Mortgage warehouse participations
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Residential
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	176,369	180,728
Residential | Residential mortgages
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	109,522	104,484
Residential | Home equity
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	66,847	76,244
Residential | Non-PCI Loans | Residential mortgages
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	107,873	102,889
Residential | Non-PCI Loans | Home equity
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	66,412	75,500
Residential | Non-PCI Loans | Pass | Residential mortgages
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	105,232	100,342
Residential | Non-PCI Loans | Pass | Home equity
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	66,002	74,841
Residential | Non-PCI Loans | Special Mention | Residential mortgages
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	1,178	1,075
Residential | Non-PCI Loans | Special Mention | Home equity
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	64
Residential | Non-PCI Loans | Substandard | Accruing Loans | Residential mortgages
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	859	753
Residential | Non-PCI Loans | Substandard | Accruing Loans | Home equity
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	353	310
Residential | Non-PCI Loans | Substandard | Nonaccruing Loans | Residential mortgages
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	315	398
Residential | Non-PCI Loans | Substandard | Nonaccruing Loans | Home equity
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	57	285
Residential | Non-PCI Loans | Doubtful | Nonaccruing Loans | Residential mortgages
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	289	321
Residential | Non-PCI Loans | Doubtful | Nonaccruing Loans | Home equity
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Residential | PCI Loans | Residential mortgages
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	1,649	1,595
Residential | PCI Loans | Home equity
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	435	744
Residential | PCI Loans | Pass | Residential mortgages
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	631	428
Residential | PCI Loans | Pass | Home equity
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	195	34
Residential | PCI Loans | Special Mention | Residential mortgages
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	325	493
Residential | PCI Loans | Special Mention | Home equity
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	74	354
Residential | PCI Loans | Substandard | Accruing Loans | Residential mortgages
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	693	674
Residential | PCI Loans | Substandard | Accruing Loans | Home equity
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	166	356
Residential | PCI Loans | Substandard | Nonaccruing Loans | Residential mortgages
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Residential | PCI Loans | Substandard | Nonaccruing Loans | Home equity
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Residential | PCI Loans | Doubtful | Nonaccruing Loans | Residential mortgages
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Residential | PCI Loans | Doubtful | Nonaccruing Loans | Home equity
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Consumer
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	54,939	45,671
Consumer | Other
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	54,939	45,671
Consumer | Non-PCI Loans | Other
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	54,929	45,671
Consumer | Non-PCI Loans | Pass | Other
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	54,677	45,422
Consumer | Non-PCI Loans | Special Mention | Other
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	19	57
Consumer | Non-PCI Loans | Substandard | Accruing Loans | Other
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	58	192
Consumer | Non-PCI Loans | Substandard | Nonaccruing Loans | Other
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	175	0
Consumer | Non-PCI Loans | Doubtful | Nonaccruing Loans | Other
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Consumer | PCI Loans | Other
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	10	0
Consumer | PCI Loans | Pass | Other
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Consumer | PCI Loans | Special Mention | Other
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Consumer | PCI Loans | Substandard | Accruing Loans | Other
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	10	0
Consumer | PCI Loans | Substandard | Nonaccruing Loans | Other
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	0	0
Consumer | PCI Loans | Doubtful | Nonaccruing Loans | Other
Financing Receivable, Impaired [Line Items]
Financing receivable, gross	$ 0	$ 0

Loans and Allowance for Loan_10

Loans and Allowance for Loan Losses (Financing Receivables Past Due) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	$ 2,030,154	$ 1,915,644
Nonaccruing	2,716	2,614
Loans, Total ending allowance balance	2,041,330	1,937,649
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total ending allowance balance	1,810,022	1,711,250
Commercial | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	646,461	606,677
Nonaccruing	318	19
Loans, Total ending allowance balance	648,349	615,359
Commercial | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	969,116	932,916
Nonaccruing	1,562	1,592
Loans, Total ending allowance balance	974,054	940,415
Commercial | Construction and land
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	159,518	114,988
Nonaccruing	0	0
Loans, Total ending allowance balance	159,781	115,495
Commercial | Mortgage warehouse participations
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	27,838	39,981
Nonaccruing	0	0
Loans, Total ending allowance balance	27,838	39,981
Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total ending allowance balance	176,369	180,728
Residential | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	106,343	100,402
Nonaccruing	604	719
Loans, Total ending allowance balance	109,522	104,484
Residential | Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	66,131	75,081
Nonaccruing	57	284
Loans, Total ending allowance balance	66,847	76,244
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total ending allowance balance	54,939	45,671
Consumer | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	54,747	45,599
Nonaccruing	175	0
Loans, Total ending allowance balance	54,939	45,671
Accruing 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	2,153	7,339
Accruing 30-89 Days Past Due | Commercial | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	516	3,239
Accruing 30-89 Days Past Due | Commercial | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	472	2,156
Accruing 30-89 Days Past Due | Commercial | Construction and land
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	8	267
Accruing 30-89 Days Past Due | Commercial | Mortgage warehouse participations
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	0	0
Accruing 30-89 Days Past Due | Residential | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	926	1,470
Accruing 30-89 Days Past Due | Residential | Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	224	135
Accruing 30-89 Days Past Due | Consumer | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	7	72
Accruing 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	0	298
Accruing 90 Days Past Due | Commercial | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	0	0
Accruing 90 Days Past Due | Commercial | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	0	0
Accruing 90 Days Past Due | Commercial | Construction and land
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	0	0
Accruing 90 Days Past Due | Commercial | Mortgage warehouse participations
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	0	0
Accruing 90 Days Past Due | Residential | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	0	298
Accruing 90 Days Past Due | Residential | Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	0	0
Accruing 90 Days Past Due | Consumer | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing past due	0	0
PCI Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	6,307	11,754
Loans, Total ending allowance balance	6,307	11,754
PCI Loans | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total ending allowance balance	1,054	5,424
PCI Loans | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total ending allowance balance	2,904	3,751
PCI Loans | Construction and land
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total ending allowance balance	255	240
PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	1,054	5,424
PCI Loans | Commercial | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	2,904	3,751
PCI Loans | Commercial | Construction and land
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	255	240
PCI Loans | Commercial | Mortgage warehouse participations
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	0	0
Loans, Total ending allowance balance	0	0
PCI Loans | Residential | Residential mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	1,649	1,595
Loans, Total ending allowance balance	1,649	1,595
PCI Loans | Residential | Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	435	744
Loans, Total ending allowance balance	435	744
PCI Loans | Consumer | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Current	10	0
Loans, Total ending allowance balance	$ 10	$ 0

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Total other intangibles, net	$ 4,867,000			$ 4,867,000		$ 5,874,000
Goodwill	21,690,000	$ 21,690,000	$ 21,759,000	21,690,000	$ 21,759,000	21,759,000	$ 21,759,000	$ 21,759,000
Total goodwill and other intangible assets, net	26,557,000			26,557,000		27,633,000
Goodwill impairment	0	69,000	0	69,000	0
Core Deposits
Finite-Lived Intangible Assets [Line Items]
Core deposit intangible	9,544,000			9,544,000		9,544,000
Less: accumulated amortization	(5,582,000)			(5,582,000)		(4,624,000)
Less: impairment related to divested branches	(2,286,000)			(2,286,000)		(2,286,000)
Core deposit intangible, net	1,676,000	$ 1,972,000	$ 3,001,000	1,676,000	$ 3,001,000	2,634,000	$ 3,392,000	$ 4,624,000
Servicing assets, net	9,544,000			9,544,000		9,544,000
Servicing Assets
Finite-Lived Intangible Assets [Line Items]
Core deposit intangible	3,191,000			3,191,000		3,240,000
Servicing assets, net	$ 3,191,000			$ 3,191,000		$ 3,240,000

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets (Goodwill and Other Intangible Assets Activity) (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Goodwill
Balance, beginning of period	$ 21,690,000		$ 21,759,000	$ 21,759,000	$ 21,759,000
Goodwill impairment	0	$ (69,000)	0	(69,000)	0
Balance, end of period	21,690,000	21,690,000	21,759,000	21,690,000	21,759,000
Core Deposit Intangible
Amortization	(296,000)		(391,000)	(958,000)	(1,286,000)
Impairment	0		0	(69,000)	(337,000)
Total
Balance, beginning of period	23,662,000		25,151,000	24,393,000	26,383,000
Amortization	(296,000)		(391,000)	(958,000)	(1,286,000)
Balance, end of period	23,366,000	23,662,000	24,760,000	23,366,000	24,760,000
Core Deposits
Core Deposit Intangible
Balance, beginning of period	1,972,000		3,392,000	2,634,000	4,624,000
Amortization	(296,000)		(391,000)	(958,000)	(1,286,000)
Impairment			0		(337,000)
Balance, end of period	1,676,000	$ 1,972,000	3,001,000	1,676,000	3,001,000
Total
Amortization	$ (296,000)		$ (391,000)	$ (958,000)	$ (1,286,000)

Servicing Assets (Narrative) (D

Servicing Assets (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Transfers and Servicing [Abstract]
Loans sold and serviced	$ 152.2	$ 135.8

Servicing Assets (SBA) (Details

Servicing Assets (SBA) (Details) - SBA Loan Servicing Assets - Commercial Loan - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
SBA Loan Servicing Rights
Beginning carrying value, net	$ 2,827	$ 2,564	$ 2,635	$ 2,359
Additions	120	157	739	750
Amortization	(239)	(221)	(666)	(609)
Impairment	0	0	0	0
Ending carrying value	$ 2,708	$ 2,500	$ 2,708	$ 2,500

Servicing Assets (Sensitivity o

Servicing Assets (Sensitivity of the Fair Value to Immediate Changes in Key Economic Assumptions) (Details) - Commercial - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
SBA Loan Servicing Assets
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]
Fair value of retained servicing assets	$ 2,731	$ 2,865
Weighted average life	5 years 1 month 5 days	6 years 2 months 19 days
Prepayment speed:	11.06%	8.64%
Decline in fair value due to a 10% adverse change	$ (123)	$ (103)
Decline in fair value due to a 20% adverse change	$ (214)	$ (181)
Weighted average discount rate	15.72%	13.01%
Decline in fair value due to a 100 bps adverse change	$ (99)	$ (103)
Decline in fair value due to a 200 bps adverse change	(167)	(180)
TriNet Servicing Assets
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]
Fair value of retained servicing assets	$ 565	$ 697
Weighted average life	7 years 4 months 4 days	7 years 4 months 15 days
Prepayment speed:	5.00%	5.00%
Decline in fair value due to a 10% adverse change	$ (8)	$ (10)
Decline in fair value due to a 20% adverse change	$ (15)	$ (20)
Weighted average discount rate	8.00%	8.00%
Decline in fair value due to a 100 bps adverse change	$ (14)	$ (19)
Decline in fair value due to a 200 bps adverse change	$ (27)	$ (37)

Servicing Assets (TriNet) (Deta

Servicing Assets (TriNet) (Details) - TriNet Servicing Assets - Commercial Loan - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Servicing Rights
Beginning carrying value, net	$ 523	$ 731	$ 605	$ 825
Additions	0	0	0	0
Amortization	(40)	(46)	(122)	(140)
Impairment	0	0	0	0
Ending carrying value	$ 483	$ 685	$ 483	$ 685

Other Comprehensive Income (L_3

Other Comprehensive Income (Loss) (Summary of Changes) (Details) - USD ($)	Jan. 01, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax (Expense) Benefit
Reclassification of tax effects from AOCI	$ 0			$ 0
After-Tax Amount
Accumulated other comprehensive income (loss) beginning of period	308,425,000			308,425,000	$ 303,658,000
Other comprehensive income (loss), net of tax		$ (3,553,000)	$ 408,000	(13,717,000)	3,763,000
Accumulated other comprehensive income (loss) end of period		320,237,000	324,754,000	320,237,000	324,754,000
Unrealized net gains (losses) on investment securities available-for-sale
Pre-Tax Amount
Unrealized net gains (losses) on investment securities available-for-sale		(4,160,000)	706,000	(15,097,000)	6,366,000
Reclassification adjustment for net realized losses on investment securities available-for-sale		0	80,000	2,000	80,000
Income Tax (Expense) Benefit
Unrealized net gains (losses) on investment securities available-for-sale		1,041,000	(272,000)	3,775,000	(2,450,000)
Reclassification adjustment for net realized losses on investment securities available-for-sale		0	(31,000)	(1,000)	(31,000)
After-Tax Amount
Unrealized net gains (losses) on investment securities available-for-sale		(3,119,000)	434,000	(11,322,000)	3,916,000
Reclassification adjustment for net realized losses on investment securities available-for-sale		0	49,000	1,000	49,000
Unrealized net gains (losses) on derivatives
Pre-Tax Amount
Unrealized net gains (losses) on derivatives		(579,000)	(121,000)	(3,195,000)	(327,000)
Income Tax (Expense) Benefit
Unrealized net gains (losses) on derivatives		145,000	46,000	799,000	125,000
After-Tax Amount
Other comprehensive income (loss), net of tax		(434,000)	(75,000)	(2,396,000)	(202,000)
Accumulated Other Comprehensive Income (Loss)
Pre-Tax Amount
Accumulated other comprehensive income (loss) beginning of period	(6,274,000)	(19,825,000)	(3,690,000)	(6,274,000)	(9,144,000)
Reclassification of tax effects from AOCI		0		0
Accumulated other comprehensive income (loss) end of period		(24,564,000)	(3,025,000)	(24,564,000)	(3,025,000)
Income Tax (Expense) Benefit
Accumulated other comprehensive income (loss) beginning of period	2,415,000	4,958,000	1,420,000	2,415,000	3,519,000
Reclassification of tax effects from AOCI		0		(844,000)
Accumulated other comprehensive income (loss) end of period		6,144,000	1,163,000	6,144,000	1,163,000
After-Tax Amount
Accumulated other comprehensive income (loss) beginning of period	$ (3,859,000)	(14,867,000)	(2,270,000)	(3,859,000)	(5,625,000)
Reclassification of tax effects from AOCI		0		(844,000)
Accumulated other comprehensive income (loss) end of period		$ (18,420,000)	$ (1,862,000)	$ (18,420,000)	$ (1,862,000)

Earnings Per Common Share (Comp

Earnings Per Common Share (Computation of Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Net income available to common shareholders	$ 6,513	$ 4,052	$ 19,702	$ 11,611
Weighted average shares outstanding
Basic (in shares)	26,103,397	25,699,179	25,956,336	25,548,646
Effect of dilutive securities:
Stock options, warrants and performance share awards	151,375	191,600	178,319	251,205
Diluted (in shares)	26,254,772	25,890,779	26,134,655	25,799,851
Income per common share:
Basic (in dollars per share)	$ 0.25	$ 0.16	$ 0.76	$ 0.45
Diluted (in dollars per share)	$ 0.25	$ 0.16	$ 0.75	$ 0.45

Earnings Per Common Share (Narr

Earnings Per Common Share (Narrative) (Details) - shares	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Mar. 24, 2015
Earnings Per Share [Abstract]
Antidilutive securities excluded (in shares)	244	550
Capital shares, authorized (in shares)				110,000,000
Preferred stock authorized (in shares)	10,000,000		10,000,000	10,000,000
Common stock authorized (in shares)	100,000,000		100,000,000	100,000,000
Common stock issued (in shares)	26,103,666		25,712,909
Common stock outstanding (in shares)	26,103,666		25,712,909

Derivatives and Hedging (Narrat

Derivatives and Hedging (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Derivative [Line Items]
Notional Amount	$ 10,000,000		$ 10,000,000		$ 14,800,000
Expected reclassification from AOCI in the next twelve months	461,000		461,000
Collateral posted	9,100,000		9,100,000		8,800,000
Not designated as hedging instrument | Other assets
Derivative [Line Items]
Notional Amount	147,017,000		147,017,000		166,113,000
Swap | Not designated as hedging instrument
Derivative [Line Items]
Notional Amount	111,000,000		111,000,000		142,300,000
Swap | Not designated as hedging instrument | Other assets
Derivative [Line Items]
Notional Amount	55,483,000		55,483,000		71,160,000
Cash Flow Hedging
Derivative [Line Items]
Hedge ineffectiveness gain (loss) recognized	0	$ 0	0	$ 0
Cash Flow Hedging | Designated as hedging instrument | LIBOR
Derivative [Line Items]
Notional Amount	$ 100,000,000		$ 100,000,000		$ 100,000,000

Derivatives and Hedging (Deriva

Derivatives and Hedging (Derivative Contracts and Credit Risk Participation Agreements) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Derivative [Line Items]
Notional Amount	$ 10,000	$ 14,800
Designated as hedging instrument | Cash Flow Hedging | LIBOR
Derivative [Line Items]
Notional Amount	100,000	100,000
Not designated as hedging instrument | Swap
Derivative [Line Items]
Notional Amount	111,000	142,300
Other assets | Not designated as hedging instrument
Derivative [Line Items]
Notional Amount	147,017	166,113
Fair Value	4,572	3,018
Other assets | Not designated as hedging instrument | Swap
Derivative [Line Items]
Notional Amount	55,483	71,160
Fair Value	1,650	946
Other assets | Not designated as hedging instrument | Zero premium collar
Derivative [Line Items]
Notional Amount	91,534	94,953
Fair Value	2,922	2,072
Other liabilities | Designated as hedging instrument | Cash Flow Hedging | LIBOR
Derivative [Line Items]
Notional Amount	100,000	100,000
Fair Value	3,998	887
Other liabilities | Not designated as hedging instrument
Derivative [Line Items]
Notional Amount	157,018	180,920
Fair Value	4,554	3,136
Other liabilities | Not designated as hedging instrument | Swap
Derivative [Line Items]
Notional Amount	55,483	71,160
Fair Value	1,631	975
Other liabilities | Not designated as hedging instrument | Credit risk participation
Derivative [Line Items]
Notional Amount	10,001	14,807
Fair Value	1	4
Other liabilities | Not designated as hedging instrument | Dealer offset to zero premium collar
Derivative [Line Items]
Notional Amount	91,534	94,953
Fair Value	$ 2,922	$ 2,157

Derivatives and Hedging (Impact

Derivatives and Hedging (Impact to Consolidated Statements of Income Related to Derivative Contracts) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Cash Flow Hedging | Interest rate swaps
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)	$ (598)	$ (75)	$ (3,093)	$ (202)
Gain or (Loss) Reclassified from Accumulated OCI in Income (Effective Portion)	(18)	84	103	331
Not designated as hedging instrument
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Income on Derivative	10	(3)	136	(127)
Not designated as hedging instrument | Other income / (expense) | Interest rate products
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Income on Derivative	10	(3)	132	(121)
Not designated as hedging instrument | Other income / (expense) | Other contracts
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Income on Derivative	0	0	4	(6)
Not designated as hedging instrument | Other income / (expense) | Fee income
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Income on Derivative	$ 10	$ 0	$ 18	$ 189

Other Borrowings and Long Ter_3

Other Borrowings and Long Term Debt (Schedule of Borrowings) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Federal Home Loan Bank borrowings	$ 83,000	$ 45,000
FHLB short-term borrowings
Debt Instrument [Line Items]
Federal Home Loan Bank borrowings	83,000	45,000
FHLB short-term borrowings | Fixed rate advance maturing October 1, 2018
Debt Instrument [Line Items]
Federal Home Loan Bank borrowings	$ 30,000
Interest Rate	2.09%
FHLB short-term borrowings | Fixed rate advance maturing October 2, 2018
Debt Instrument [Line Items]
Federal Home Loan Bank borrowings	$ 53,000
Interest Rate	2.088%
FHLB short-term borrowings | Fixed rate advance maturing January 16, 2018
Debt Instrument [Line Items]
Federal Home Loan Bank borrowings		$ 45,000
Interest Rate		1.40%

Other Borrowings and Long Ter_4

Other Borrowings and Long Term Debt (Narrative) (Details) - Subordinated Debt - USD ($)	Sep. 28, 2015	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Aggregate principal amount		$ 50,000,000	$ 50,000,000
Maturity, more than		5 years
6.25% Subordinated Note, Due September 2020
Debt Instrument [Line Items]
Aggregate principal amount	$ 50,000,000	$ 50,000,000	$ 50,000,000
Stated interest rate	6.25%	6.25%
Debt instrument redemption price	100.00%
Maturity, more than		10 years
Subordinated Note After September 30, 2020 Due September 2025
Debt Instrument [Line Items]
Basis spread on variable rate		4.68%

Other Borrowings and Long Ter_5

Other Borrowings and Long Term Debt (Schedule of Subordinated Debt) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Sep. 28, 2015
Debt Instrument [Line Items]
Subordinated debt, net	$ 49,662,000	$ 49,535,000
Subordinated Debt
Debt Instrument [Line Items]
Aggregate principal amount	50,000,000	50,000,000
Less debt issuance costs	338,000	465,000
Subordinated debt, net	$ 49,662,000	49,535,000
Debt instrument term	5 years
Subordinated Debt | 6.25% Subordinated Note, Due September 2020
Debt Instrument [Line Items]
Aggregate principal amount	$ 50,000,000	$ 50,000,000	$ 50,000,000
Debt instrument term	10 years
Stated interest rate	6.25%		6.25%

Share-Based Compensation (Narra

Share-Based Compensation (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)shares	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)individualshares	Sep. 30, 2017USD ($)shares	Dec. 31, 2017shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)			15,000
Share based compensation expense | $	$ 70	$ 191	$ 167	$ 472
Number of employees affected | individual			2
Total incremental cost resulting from modifications | $			$ 111
Warrant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding (shares)	0		0		0
Warrants granted (in shares)				0
2015 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (shares)	4,525,000		4,525,000
Number of additional shares authorized (shares)			3,515,000
Award vesting period			3 years
Term of award			10 years
Restricted Stock And Performance Share Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation expense | $	$ 444	$ 396	$ 1,300	$ 869
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized | $	$ 2,900		$ 2,900
Compensation cost not yet recognized, period for recognition			2 years 6 months 10 days
Number of awards modified (in shares)			6,869
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards modified (in shares)			15,000

Share-Based Compensation (Fair

Share-Based Compensation (Fair Value of Options Assumptions) (Details) - Employee Stock Option	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk‑free interest rate	1.66%
Risk-free interest rate, minimum		1.00%
Risk-free interest rate, maximum		1.99%
Expected term in years	3 months
Expected stock price volatility	24.20%
Expected stock price volatility, minimum		23.20%
Expected stock price volatility, maximum		25.30%
Dividend yield	0.00%	0.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term in years		3 months
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term in years		8 years

Share-Based Compensation (Stock

Share-Based Compensation (Stock Option and Warrant Activity) (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)$ / sharesshares
Shares
Outstanding, Beginning of period (in shares)	757,711
Granted/modified, in shares	15,000
Exercised (in shares)	(300,616)
Forfeited (in shares)	(19,935)
Expired (in shares)	(306)
Outstanding, End of period (in shares)	451,854
Exercisable, End of period (in shares)	371,974
Modified (in shares)	15,000
Weighted Average Exercise Price
Outstanding, Weighted average exercise price, Beginning of period (dollars per share) | $ / shares	$ 12.66
Granted/modified, Weighted average exercise price (dollars per share) | $ / shares	14.64
Exercised, Weighted average exercise price (dollars per share) | $ / shares	13.32
Forfeited, Weighted average exercise price (dollars per share) | $ / shares	14.08
Expired, Weighted average exercise price (dollars per share) | $ / shares	105.97
Outstanding, Weighted average exercise price, End of period (dollars per share) | $ / shares	11.97
Exercisable, Weighted average exercise price, End of period (dollars per share) | $ / shares	$ 11.39
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding, Weighted average remaining contractual term, End of period (in years)	4 years 3 months
Exercisable, Weighted average remaining contractual term, End of period (in years)	3 years 7 months 17 days
Outstanding, Aggregate intrinsic value, End of period | $	$ 2,185
Exercisable, Aggregate intrinsic value, End of period | $	$ 2,022

Share-Based Compensation (Restr

Share-Based Compensation (Restricted Stock Activity) (Details) - Restricted Stock	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning of period (in shares)	239,468
Granted/modified (in shares)	135,757
Vested (in shares)	(59,300)
Forfeited (in shares)	(30,888)
End of period (in shares)	285,037
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted average grant date fair value, Nonvested, Beginning of period (dollars per share) | $ / shares	$ 15.69
Weighted average grant date fair value, Granted/modified(dollars per share) | $ / shares	19.89
Weighted average grant date fair value, Vested (dollars per share) | $ / shares	15.16
Weighted average grant date fair value, Forfeited (dollars per share) | $ / shares	15.97
Weighted average grant date fair value, Nonvested, End of period (dollars per share) | $ / shares	$ 17.78
Modified (in shares)	6,869

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Measurements Recurring) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	$ 465,756	$ 449,117
Interest rate derivative assets	4,572	3,018
Interest rate derivative liabilities	8,552	4,023
Fair Value | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	465,756	449,117
Interest rate derivative assets	4,572	3,018
Interest rate derivative liabilities	8,552	4,023
Fair Value | Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Securities (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	0	0
Interest rate derivative assets	0	0
Interest rate derivative liabilities	0	0
Fair Value | Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	465,756	449,117
Interest rate derivative assets	4,572	3,018
Interest rate derivative liabilities	8,552	4,023
Fair Value | Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	0	0
Interest rate derivative assets	0	0
Interest rate derivative liabilities	0	0
Fair Value | U.S. government agencies | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	35,445	34,111
Fair Value | U.S. government agencies | Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Securities (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	0	0
Fair Value | U.S. government agencies | Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	35,445	34,111
Fair Value | U.S. government agencies | Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	0	0
Fair Value | U.S. states and political subdivisions | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	82,665	90,001
Fair Value | U.S. states and political subdivisions | Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Securities (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	0	0
Fair Value | U.S. states and political subdivisions | Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	82,665	90,001
Fair Value | U.S. states and political subdivisions | Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	0	0
Fair Value | Trust preferred securities | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	4,625	4,650
Fair Value | Trust preferred securities | Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Securities (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	0	0
Fair Value | Trust preferred securities | Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	4,625	4,650
Fair Value | Trust preferred securities | Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	0	0
Fair Value | Corporate debt securities | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	12,369	12,622
Fair Value | Corporate debt securities | Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Securities (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	0	0
Fair Value | Corporate debt securities | Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	12,369	12,622
Fair Value | Corporate debt securities | Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	0	0
Fair Value | Mortgage-backed securities | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	330,652	307,733
Fair Value | Mortgage-backed securities | Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Securities (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	0	0
Fair Value | Mortgage-backed securities | Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	330,652	$ 307,733
Fair Value | Mortgage-backed securities | Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	$ 0

Fair Value Measurements (Fair_2

Fair Value Measurements (Fair Value Measurements Nonrecurring) (Details) - Impaired Loans - Fair Value - Fair value, measurements, nonrecurring - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 1,588	$ 2,199
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 1,588	$ 2,199

Fair Value Measurements (Estima

Fair Value Measurements (Estimated Fair Value and Carrying Value Summary) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and due from banks	$ 28,007	$ 38,086
Interest-bearing deposits in banks	140,682	281,247
Other short-term investments	20,898	10,681
Total securities available-for-sale	465,756	449,117
Loans held for investment, net	2,017,991	1,914,495
Derivative assets	4,572	3,018
Subordinated debt	49,662	49,535
FHLB advances	83,000	45,000
Derivative financial instruments	8,552	4,023
Fair value, measurements, recurring | Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and due from banks	28,007	38,086
Interest-bearing deposits in banks	140,682	281,247
Other short-term investments	20,898	10,681
Total securities available-for-sale	465,756	449,117
FHLB stock	6,150	4,388
Federal Reserve Bank stock	9,842	9,792
Loans held for investment, net	2,017,991	1,914,495
Loans held for sale	1,886	1,487
Derivative assets	4,572	3,018
Deposits	2,379,824	2,450,665
Federal funds purchased and securities sold under agreements to repurchase	8,904
Subordinated debt	49,662	49,535
FHLB advances	83,000	45,000
Derivative financial instruments	8,552	4,023
Fair value, measurements, recurring | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available-for-sale	465,756	449,117
Derivative assets	4,572	3,018
Derivative financial instruments	8,552	4,023
Fair value, measurements, recurring | Fair Value | Quoted Prices in Active Markets for Identical Securities (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and due from banks	28,007	38,086
Interest-bearing deposits in banks	140,682	281,247
Other short-term investments	20,898	10,681
Total securities available-for-sale	0	0
FHLB stock	0	0
Federal Reserve Bank stock	0	0
Loans held for investment, net	0	0
Loans held for sale	0	0
Derivative assets	0	0
Deposits	0	0
Federal funds purchased and securities sold under agreements to repurchase	8,904
Subordinated debt	0	0
FHLB advances	0	0
Derivative financial instruments	0	0
Fair value, measurements, recurring | Fair Value | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and due from banks	0	0
Interest-bearing deposits in banks	0	0
Other short-term investments	0	0
Total securities available-for-sale	465,756	449,117
FHLB stock	0	0
Federal Reserve Bank stock	0	0
Loans held for investment, net	0	0
Loans held for sale	1,886	1,487
Derivative assets	4,572	3,018
Deposits	2,208,910	2,411,810
Federal funds purchased and securities sold under agreements to repurchase	0
Subordinated debt	48,995	49,888
FHLB advances	83,011	45,057
Derivative financial instruments	8,552	4,023
Fair value, measurements, recurring | Fair Value | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and due from banks	0	0
Interest-bearing deposits in banks	0	0
Other short-term investments	0	0
Total securities available-for-sale	0	0
FHLB stock	6,150	4,388
Federal Reserve Bank stock	9,842	9,792
Loans held for investment, net	1,963,794	1,955,705
Loans held for sale	0	0
Derivative assets	0	0
Deposits	0	0
Federal funds purchased and securities sold under agreements to repurchase	0
Subordinated debt	0	0
FHLB advances	0	0
Derivative financial instruments	$ 0	$ 0

Commitments and Contingencies_2

Commitments and Contingencies (Exposure to Credit Risk) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Loss Contingencies [Line Items]
Maximum credit risk exposure	$ 730,853	$ 700,711
Commitments to extend credit
Loss Contingencies [Line Items]
Maximum credit risk exposure	717,847	689,753
Standby letters of credit
Loss Contingencies [Line Items]
Maximum credit risk exposure	$ 13,006	$ 10,958

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Retained earnings	$ 33,357		$ 33,357			$ 12,810
Deposit account analysis fees and charges
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	654	$ 551	1,860	$ 1,567
ATM fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	276	370	863	1,182
NSF fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	177	176	541	625
Wire fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	110	88	302	266
Foreign Exchange Fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	54	50	186	186
Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	7	12	26	44
Total service charges
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,278	1,247	3,778	3,870
Personal trust and agency accounts
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	259	616	728
Employee benefit and retirement-related trust and agency accounts
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	58	120	166
Investment management and investment advisory agency accounts
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	89	217	263
Custody and safekeeping accounts
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	12	26	43
Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	19	46	132
Total trust Income
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 0	$ 437	$ 1,025	$ 1,332
Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
Disaggregation of Revenue [Line Items]
Retained earnings					$ 2