Enterprise Financial Services (EFSC) 10-Q 27 Oct 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 25, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	ENTERPRISE FINANCIAL SERVICES CORP
Entity Central Index Key	1,025,835
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		23,064,850

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 76,777	$ 54,288
Federal funds sold	1,155	446
Interest-bearing deposits (including $2,949 and $675 pledged as collateral)	105,176	144,068
Total cash and cash equivalents	183,108	198,802
Interest-bearing deposits greater than 90 days	2,645	980
Securities available for sale	603,121	460,797
Securities held to maturity	76,168	80,463
Loans held for sale	6,411	9,562
Loans	4,030,658	3,158,161
Less: Allowance for loan losses	43,191	43,409
Total loans, net	3,987,467	3,114,752
Other real estate	491	980
Other investments, at cost	29,436	14,840
Fixed assets, net	32,803	14,910
Accrued interest receivable	14,213	11,117
State tax credits held for sale (including $1,274 and $3,585 carried at fair value)	35,291	38,071
Goodwill	117,345	30,334
Intangible assets, net	11,745	2,151
Other assets	131,244	103,569
Total assets	5,231,488	4,081,328
Liabilities and Shareholders' Equity
Demand deposits	1,047,910	866,756
Interest-bearing transaction accounts	814,338	731,539
Money market accounts	1,375,844	1,050,472
Savings	203,923	111,435
Certificates of deposit:
Brokered	170,701	117,145
Other	446,495	356,014
Total deposits	4,059,211	3,233,361
Subordinated debentures and notes (net of debt issuance cost of $1,169 and $1,267)	118,093	105,540
Federal Home Loan Bank advances	248,868	0
Other borrowings	209,104	276,980
Notes payable	10,000	0
Accrued interest payable	2,007	1,105
Other liabilities	37,869	77,244
Total liabilities	4,685,152	3,694,230
Shareholders' equity:
Preferred stock, $0.01 par value; 5,000,000 shares authorized; 0 shares issued and outstanding	0	0
Common stock, $0.01 par value; 30,000,000 shares authorized; 23,754,814 and 20,306,353 shares issued	237	203
Treasury stock, at cost; 691,673 and 261,718 shares, respectively	(23,268)	(6,632)
Additional paid in capital	349,485	213,078
Retained earnings	220,371	182,190
Accumulated other comprehensive loss	(489)	(1,741)
Total shareholders' equity	546,336	387,098
Total liabilities and shareholders' equity	$ 5,231,488	$ 4,081,328

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Assets
Collateral pledged	$ 2,949	$ 675
State tax credits held for sale	1,274	3,585
Payments of Debt Issuance Costs	$ 1,169	$ 1,267
Shareholders' equity:
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	23,754,814	20,306,353
Treasury stock, shares	691,673	261,718

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Interest income:
Interest and fees on loans	$ 48,020	$ 34,442	$ 135,253	$ 101,233
Interest on debt securities:
Taxable	3,855	2,410	10,670	7,194
Nontaxable	294	322	984	982
Interest on interest-bearing deposits	173	67	537	186
Dividends on equity securities	126	52	306	191
Total interest income	52,468	37,293	147,750	109,786
Interest expense:
Interest-bearing transaction accounts	523	332	1,721	967
Money market accounts	2,410	1,143	5,841	3,162
Savings accounts	125	68	332	191
Certificates of deposit	1,493	1,319	4,081	3,521
Subordinated debentures and notes	1,316	369	3,768	1,078
Federal Home Loan Bank advances	832	126	1,684	499
Notes payable and other borrowings	144	106	423	327
Total interest expense	6,843	3,463	17,850	9,745
Net interest income	45,625	33,830	129,900	100,041
Provision for portfolio loan losses	2,422	3,038	7,578	4,587
Provision reversal for purchased credit impaired loan losses	0	(1,194)	(355)	(1,603)
Net interest income after provision for loan losses	43,203	31,986	122,677	97,057
Noninterest income:
Service charges on deposit accounts	2,820	2,200	8,146	6,431
Wealth management revenue	2,062	1,694	5,949	5,000
Fees and Commissions, Credit and Debit Cards	1,459	804	3,888	2,236
Gain on state tax credits, net	77	228	332	899
Gain (loss) on sale of other real estate	0	(226)	17	602
Gain on sale of investment securities	22	86	22	86
Miscellaneous income	1,932	2,190	4,928	4,776
Total noninterest income	8,372	6,976	23,282	20,030
Noninterest expense:
Employee compensation and benefits	15,090	12,091	46,096	37,398
Occupancy	2,434	1,705	6,628	4,997
Data processing	1,389	1,150	4,828	3,441
Professional fees	922	757	2,838	2,160
FDIC and other insurance	882	780	2,356	2,241
Loan legal and other real estate expense	586	416	1,544	1,126
Merger related expenses	315	302	6,462	302
Other	5,786	3,613	16,039	11,264
Total noninterest expense	27,404	20,814	86,791	62,929
Income before income tax expense	24,171	18,148	59,168	54,158
Income tax expense	7,856	6,316	18,507	18,949
Net income	$ 16,315	$ 11,832	$ 40,661	$ 35,209
Earnings per common share
Basic (usd per share)	$ 0.70	$ 0.59	$ 1.77	$ 1.76
Diluted (usd per share)	$ 0.69	$ 0.59	$ 1.75	$ 1.74

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 16,315	$ 11,832	$ 40,661	$ 35,209
Other comprehensive income (loss), net of tax:
Unrealized gains (losses) on investment securities arising during the period, net of income tax expense (benefit) for three months of $(493) and $(494), and for nine months of $775 and $2,795, respectively	(805)	(796)	1,265	4,503
Less: Reclassification adjustment for realized gains on sale of securities available for sale included in net income, net of income tax expense for three months of $8 and $33, and for nine months of $8 and $33, respectively	(13)	(53)	(13)	(53)
Total other comprehensive income (loss)	(818)	(849)	1,252	4,450
Total comprehensive income	$ 15,497	$ 10,983	$ 41,913	$ 39,659

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2017	Sep. 30, 2016
Other comprehensive income, tax:
Unrealized (loss)/gain on investment securities available for sale arising during the period, tax	$ (493)			$ (494)			$ 775	$ 2,795
Reclassification adjustment for realized gains on sale of securities available for sale included in net income, tax		$ 8	$ 8		$ 33	$ 33

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Treasury Stock	Additional paid in capital	Retained earnings	Accumulated other comprehensive income (loss)
Balance at Dec. 31, 2015	$ 350,829	$ 0	$ 201	$ (1,743)	$ 210,589	$ 141,564	$ 218
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	35,209	0	0	0	0	35,209	0
Other comprehensive income	4,450	0	0	0	0	0	4,450
Total comprehensive income	39,659
Payments of Ordinary Dividends, Common Stock	(6,005)	0	0	0	0	(6,005)	0
Adjustments To Additional Paid In Capital, Repurchase Of Common Stock Warrants	(4,889)	0	0	(4,889)	0	0	0
Issuance under equity compensation plans, net	(1,650)	0	(2)	0	1,652	0	0
Share-based Compensation	2,410	0	0	0	2,410	0	0
Excess tax benefit related to equity compensation plans	744	0	0	0	744	0	0
Balance at Sep. 30, 2016	381,098	0	203	(6,632)	212,091	170,768	4,668
Balance at Dec. 31, 2016	387,098	0	203	(6,632)	213,078	182,190	(1,741)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	40,661	0	0	0	0	40,661	0
Other comprehensive income	1,252	0	0	0	0	0	1,252
Total comprehensive income	41,913	0	0	0	0	40,661	1,252
Payments of Ordinary Dividends, Common Stock	(7,709)	0	0	0	0	(7,709)	0
Adjustments To Additional Paid In Capital, Repurchase Of Common Stock Warrants	(16,636)	0	0	(16,636)	0	0	0
Issuance under equity compensation plans, net	(2,573)	0	(1)	0	2,574	0	0
Share-based Compensation	2,514	0	0	0	2,514	0	0
Shares issued in connection with acquisition	141,729	0	33	0	141,696	0	0
Reclassification for the adoption of ASU 2016-09	0	0	0	0	(5,229)	5,229	0
Balance at Sep. 30, 2017	$ 546,336	$ 0	$ 237	$ (23,268)	$ 349,485	$ 220,371	$ (489)

Condensed Consolidated Stateme8

Condensed Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash dividends paid on common shares, per share	$ 0.33	$ 0.30
Issuance under equity compensation plans, shares	148,597	156,592

Condensed Consolidated Stateme9

Condensed Consolidated Statements of Cash Flows $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)
Cash flows from operating activities:
Net income	$ 40,661	$ 35,209
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation	2,426	1,628
Provision for loan losses	7,223	2,984
Deferred income taxes	1,239	3,881
Net amortization of debt securities	2,064	2,350
Amortization of intangible assets	1,920	718
Gain on sale of investment securities	(22)	(86)
Mortgage loans originated for sale	(115,365)	(117,975)
Proceeds from mortgage loans sold	118,798	117,639
Gain on sale of other real estate	(17)	(602)
Gain on state tax credits, net	(332)	(899)
Excess tax benefit of share-based compensation	0	(744)
Share-based Compensation	2,514	2,410
Net accretion of loan discount	(3,796)	(8,165)
Changes in:
Accrued interest receivable	(302)	(127)
Accrued interest payable	249	19
Other assets	755	(2,100)
Other liabilities	(44,398)	(8,057)
Net cash provided by operating activities	13,617	28,083
Cash flows from investing activities:
Proceeds from Previous Acquisition	4,456	0
Net increase in loans	(201,715)	(256,706)
Proceeds from the sale of securities, available for sale	144,076	2,493
Proceeds from the paydown or maturity of securities, available for sale	126,073	46,017
Proceeds from the paydown or maturity of securities, held to maturity	4,145	2,592
Proceeds from the redemption of other investments	29,159	44,968
Proceeds from the sale of state tax credits held for sale	4,391	4,918
Proceeds from the sale of other real estate	2,513	8,072
Payments for the purchase/origination of:
Available for sale debt and equity securities	(263,453)	(71,309)
Other investments	(45,224)	(48,283)
State tax credits held for sale	(145)	(2,349)
Fixed assets	(1,864)	(1,284)
Net cash used in investing activities	(197,588)	(270,871)
Cash flows from financing activities:
Net increase in noninterest-bearing deposit accounts	20,684	44,695
Net increase in interest-bearing deposit accounts	39,998	295,539
Proceeds from Federal Home Loan Bank advances	1,394,181	1,309,000
Repayments of Federal Home Loan Bank advances	(1,145,681)	(1,290,000)
Proceeds from Issuance of Long-term Debt	10,000	0
Net decrease in other borrowings	(123,987)	(80,304)
Cash dividends paid on common stock	(7,709)	(6,005)
Excess tax benefit of share-based compensation	0	744
Payments for Repurchase of Common Stock	16,636	4,889
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	(2,573)	(1,650)
Net cash provided by financing activities	168,277	267,130
Net increase (decrease) in cash and cash equivalents	(15,694)	24,342
Cash and cash equivalents, beginning of period	198,802	94,157
Cash and cash equivalents, end of period	183,108	118,499
Supplemental Cash Flow Information [Abstract]
Cash paid during the period for interest	16,948	9,726
Cash paid during the period for income taxes	9,382	19,868
Noncash transactions:
Transfer to other real estate owned in settlement of loans	289	2,683
Sales of other real estate financed	$ 0	$ 140
Common shares issued related to acquisition	141,729	0

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The significant accounting policies used by Enterprise Financial Services Corp (the "Company" or "Enterprise") in the preparation of the condensed consolidated financial statements are summarized below: Business and Consolidation Enterprise is a financial holding company that provides a full range of banking and wealth management services to individuals and corporate customers located in the St. Louis, Kansas City, and Phoenix metropolitan markets through its banking subsidiary, Enterprise Bank & Trust (the "Bank"). Operating results for the three and nine months ended September 30, 2017 are not necessarily indicative of the results that may be expected for any other interim period or for the year ending December 31, 2017 . For further information, refer to the consolidated financial statements and footnotes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2016 . Basis of Financial Statement Presentation The condensed consolidated financial statements of the Company and its subsidiaries have been prepared in accordance with the accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. The condensed consolidated financial statements include the accounts of the Company and its subsidiaries, all of which are wholly owned. All intercompany accounts and transactions have been eliminated. In 2017, the Company changed its presentation of loans on the face of the Condensed Consolidated Balance Sheets to combine originated loans with purchased loans. See Note 5 - Loans for more information. The Company also changed its presentation of the Noninterest Income section on the face of the Condensed Consolidated Statements of Operations to separate card services revenue out of miscellaneous income. The Company adopted Accounting Standards Update (ASU) 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting during the first quarter of 2017. Among other elements, the ASU requires an entity to recognize all excess tax benefits and deficiencies related to stock-based compensation expense as income tax expense or benefit in the statements of operations. The ASU requires adjustments be reflected as of the beginning of the fiscal year of adoption and as a result, $5.2 million of previously recognized excess tax benefits were reclassified from Additional paid in capital to Retained earnings during the first quarter of 2017. The adoption resulted in a decrease to income tax expense of $1.8 million for the nine months ended September 30, 2017 . Excess tax benefits related to stock compensation are presented as a cash inflow from operating activities for the nine months ended September 30, 2017 due to the prospective adoption of employee share-based payment guidance in 2017. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Acquisitions Acquisitions and business combinations are accounted for using the acquisition method of accounting. The assets and liabilities of the acquired entities have been recorded at their estimated fair values at the date of acquisition. Goodwill represents the excess of the purchase price over the fair value of net assets acquired, including the amount assigned to identifiable intangible assets. The purchase price allocation process requires an estimation of the fair values of the assets acquired and the liabilities assumed. When a business combination agreement provides for an adjustment to the cost of the combination contingent on future events, the Company includes an estimate of the acquisition-date fair value as part of the cost of the combination. To determine the fair values, the Company relies on third party valuations, such as appraisals, or internal valuations based on discounted cash flow analyses or other valuation techniques. The results of operations of the acquired business are included in the Company's consolidated financial statements from the date of acquisition. Merger-related costs are costs the Company incurs to effect a business combination. In 2017, the Company changed its presentation of Merger related expenses as a separate component of Noninterest expenses on the Condensed Consolidated Statements of Operations. Merger related expenses include costs directly related to merger or acquisition activity and include legal and professional fees, system consolidation and conversion costs, and compensation costs such as severance and retention incentives for employees impacted by acquisition activity. The Company accounts for merger-related costs as expenses in the periods in which the costs are incurred and the services are received. Purchased Credit Impaired ("PCI") Loans Purchased credit impaired ("PCI") loans were acquired in a business combination or transaction that have evidence of deterioration of credit quality since origination and for which it is probable, at acquisition, that the Company will be unable to collect all contractually required payments receivable. PCI loans were initially recorded at fair value (as determined by the present value of expected future cash flows) with no valuation allowance. The difference between the undiscounted cash flows expected at acquisition and the investment in the loans, or the “accretable yield,” is recognized as interest income on a level-yield method over the life of the loans. Contractually required payments for interest and principal that exceed the undiscounted cash flows expected at acquisition, or the “nonaccretable difference,” are not recognized as a yield adjustment or as a loss accrual or a valuation allowance. The Company aggregates individual loans with common risk characteristics into pools of loans. Increases in expected cash flows subsequent to the initial investment are recognized prospectively through adjustment of the yield on the loans over their remaining lives. Decreases in expected cash flows due to an inability to collect contractual cash flows are recognized as impairment through the provision for loan losses account. Any allowance for loan loss on these pools reflect only losses incurred after the acquisition. Disposals of loans, including sales of loans, paydowns, payments in full or foreclosures result in the removal or reduction of the loan from the loan pool. PCI loans are generally considered accruing and performing, as the loans accrete income over the estimated life of the loan, in circumstances where cash flows are reasonably estimable by management. Accordingly, PCI loans that could be contractually past due could be considered to be accruing and performing. If the timing and amount of future cash flows is not reasonably estimable or is less than the carrying value, the loans may be classified as nonaccrual loans and the purchase price discount on those loans is not recorded as interest income until the timing and amount of future cash flows can be reasonably estimable. Allowance for Loan Losses on PCI Loans The Company updates its cash flow projections for purchased credit-impaired loans on a periodic basis. Assumptions utilized in this process include projections related to probability of default, loss severity, prepayment, extensions and recovery lag. Projections related to probability of default and prepayment are calculated utilizing a loan migration analysis and management’s assessment of loss exposure including the fair value of underlying collateral. The loan migration analysis is a matrix that specifies the probability of a loan pool transitioning into a particular delinquency or liquidation state given its current performance at the measurement date. Loss severity factors are based upon industry data and historical experience. Any decreases in expected cash flows after the acquisition date and subsequent measurement periods are recognized by recording an impairment in allowance for loan losses through a provision for loan losses.

Acquisitions & Divestitures

Acquisitions & Divestitures	9 Months Ended
	Sep. 30, 2017
Business Acquisition [Line Items]
Mergers, Acquisitions and Dispositions Disclosures [Text Block]	ACQUISITIONS Acquisition of Jefferson County Bancshares, Inc. On February 10, 2017 , the Company closed its acquisition of 100% of Jefferson County Bancshares, Inc. ("JCB") and its wholly-owned subsidiary, Eagle Bank and Trust Company of Missouri. JCB operated 13 full service retail and commercial banking offices in the metropolitan St. Louis area and one in Perry County, Missouri. JCB shareholders received, based on their election, cash consideration in an amount of $85.39 per share of JCB common stock or 2.75 shares of EFSC common stock per share of JCB common stock, subject to allocation and proration procedures. Aggregate consideration at closing was 3.3 million shares of EFSC common stock and $29.3 million cash paid to JCB shareholders and holders of JCB stock options. Based on EFSC’s closing stock price of $42.95 on February 10, 2017 , the overall transaction had a value of $171.0 million , including JCB’s common stock and stock options. The Company also recognized $6.5 million and $1.4 million of merger related costs that were recorded in noninterest expense in the statement of operations for the nine months ended September 30, 2017 , and year ended December 31, 2016 , respectively. The acquisition of JCB has been accounted for as a business combination using the acquisition method of accounting which requires assets acquired and liabilities assumed to be recognized at fair value as of the acquisition date. Goodwill of $87.0 million arising from the acquisition consists largely of the synergies and economies of scale expected from combining the operations of JCB into Enterprise. The goodwill is assigned as part of the Company's Banking reporting unit. None of the goodwill recognized is expected to be deductible for income tax purposes. The following table presents the assets acquired and liabilities assumed of JCB as of February 10, 2017 , and their preliminary estimated fair values: (in thousands) As Recorded by JCB Adjustments As Recorded by EFSC Assets acquired: Cash and cash equivalents $ 33,739 $ — $ 33,739 Interest-bearing deposits 1,715 — 1,715 Securities 148,670 — 148,670 Portfolio loans, net 685,905 (11,094 ) (a) 674,811 Other real estate owned 6,762 (5,082 ) (b) 1,680 Other investments 2,695 — 2,695 Fixed assets, net 21,780 (3,325 ) (c) 18,455 Accrued interest receivable 2,794 — 2,794 Goodwill 7,806 (7,806 ) (d) — Other intangible assets 25 11,489 (e) 11,514 Deferred tax assets 4,634 3,991 (f) 8,625 Other assets 19,107 (296 ) (g) 18,811 Total assets acquired $ 935,632 $ (12,123 ) $ 923,509 Liabilities assumed: Deposits $ 764,539 $ 629 (h) $ 765,168 Other borrowings 55,430 681 (i) 56,111 Trust preferred securities 12,887 (382 ) (j) 12,505 Accrued interest payable 653 — 653 Other liabilities 5,006 65 (k) 5,071 Total liabilities assumed $ 838,515 $ 993 $ 839,508 Net assets acquired $ 97,117 $ (13,116 ) $ 84,001 Consideration paid: Cash $ 29,283 Common stock 141,729 Total consideration paid $ 171,012 Goodwill $ 87,011 (a) Fair value adjustments based on the Company’s evaluation of the acquired loan portfolio, write-off of net deferred loan costs, reclassification from other real estate owned, and elimination of the allowance for loan losses recorded by JCB. The fair value discount recorded to the loan portfolio is $24.7 million . (b) Fair value adjustment based on the Company’s evaluation of the acquired other real estate portfolio, and reclassification to portfolio loans. (c) Fair value adjustments based on the Company’s evaluation of the acquired premises and equipment. A decrease of $1.1 million was recorded during the third quarter of 2017 due to continued refinement of the purchase accounting calculations. (d) Eliminate JCB’s recorded goodwill. (e) Record the core deposit intangible asset on the acquired core deposit accounts. Amount to be amortized using a sum of years digits method over a 10 year useful life. (f) Adjustment for deferred taxes at the acquisition date. The adjustment decreased by $0.2 million during the current quarter due to continued refinement of the purchase accounting calculations. (g) Fair value adjustment based on evaluation of other assets. (h) Fair value adjustment to time deposits based on current interest rates. (i) Fair value adjustment to the FHLB advances based on current interest rates. (j) Fair value adjustment based on the Company's evaluation of the trust preferred securities. (k) A decrease of $0.1 million was recorded during the current quarter due to further refinement of the purchase accounting calculations. The following table provides the unaudited pro forma information for the results of operations for the nine months ended September 30, 2017 and 2016 , as if the acquisition had occurred on January 1, 2016. The pro forma results combine the historical results of JCB with the Company’s Consolidated Statements of Income, adjusted for the impact of the application of the acquisition method of accounting including loan discount accretion, intangible assets amortization, and deposit and trust preferred securities premium accretion, net of taxes. The pro forma results have been prepared for comparative purposes only and are not necessarily indicative of the results that would have been obtained had the acquisition actually occurred on January 1, 2016. No assumptions have been applied to the pro forma results of operations regarding possible revenue enhancements, expense efficiencies or asset dispositions. Only the acquisition related expenses that have been incurred as of September 30, 2017 are included in net income in the table below. Pro Forma Nine months ended September 30, (in thousands, except per share data) 2017 2016 Total revenues (net interest income plus noninterest income) $ 155,907 $ 146,623 Net income 40,151 42,298 Diluted earnings per common share 1.70 1.80

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE Basic earnings per common share data is calculated by dividing net income by the weighted average number of common shares outstanding during the period. Common shares outstanding include common stock and restricted stock awards where recipients have satisfied the vesting terms. Diluted earnings per common share gives effect to all dilutive potential common shares outstanding during the period using the treasury stock method. The following table presents a summary of per common share data and amounts for the periods indicated. Three months ended September 30, Nine months ended September 30, (in thousands, except per share data) 2017 2016 2017 2016 Net income as reported $ 16,315 $ 11,832 $ 40,661 $ 35,209 Weighted average common shares outstanding 23,324 19,997 22,914 20,002 Additional dilutive common stock equivalents 250 227 295 229 Weighted average diluted common shares outstanding 23,574 20,224 23,209 20,231 Basic earnings per common share: $ 0.70 $ 0.59 $ 1.77 $ 1.76 Diluted earnings per common share: $ 0.69 $ 0.59 $ 1.75 $ 1.74 For the three and nine months ended September 30, 2017 and 2016 , there were no common stock equivalents excluded from the earnings per share calculations because their effect would have been anti-dilutive.

Investments

Investments	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Investments	INVESTMENTS The following table presents the amortized cost, gross unrealized gains and losses and fair value of securities available for sale and held to maturity: September 30, 2017 (in thousands) Amortized Cost Gross Gross Fair Value Available for sale securities: Obligations of U.S. Government-sponsored enterprises $ 99,866 $ 271 $ (14 ) $ 100,123 Obligations of states and political subdivisions 32,684 887 (229 ) 33,342 Agency mortgage-backed securities 470,941 1,760 (3,045 ) 469,656 Total securities available for sale $ 603,491 $ 2,918 $ (3,288 ) $ 603,121 Held to maturity securities: Obligations of states and political subdivisions $ 14,704 $ 159 $ (15 ) $ 14,848 Agency mortgage-backed securities 61,464 93 (145 ) 61,412 Total securities held to maturity $ 76,168 $ 252 $ (160 ) $ 76,260 December 31, 2016 (in thousands) Amortized Cost Gross Gross Fair Value Available for sale securities: Obligations of U.S. Government-sponsored enterprises $ 107,312 $ 348 $ — $ 107,660 Obligations of states and political subdivisions 36,486 630 (485 ) 36,631 Agency mortgage-backed securities 319,345 1,101 (3,940 ) 316,506 Total securities available for sale $ 463,143 $ 2,079 $ (4,425 ) $ 460,797 Held to maturity securities: Obligations of states and political subdivisions $ 14,759 $ 11 $ (242 ) $ 14,528 Agency mortgage-backed securities 65,704 45 (638 ) 65,111 Total securities held to maturity $ 80,463 $ 56 $ (880 ) $ 79,639 At September 30, 2017 , and December 31, 2016 , there were no holdings of securities of any one issuer in an amount greater than 10% of shareholders’ equity, other than U.S. Government agencies and sponsored enterprises. The agency mortgage-backed securities are all issued by U.S. Government-sponsored enterprises. Available for sale securities having a fair value of $449.8 million and $407.3 million at September 30, 2017 , and December 31, 2016 , respectively, were pledged as collateral to secure deposits of public institutions and for other purposes as required by law or contract provisions. The amortized cost and estimated fair value of debt securities at September 30, 2017 , by contractual maturity, are shown below. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. The weighted average life of the mortgage-backed securities is approximately 4 years. Available for sale Held to maturity (in thousands) Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Due in one year or less $ 2,940 $ 2,960 $ — $ — Due after one year through five years 110,538 111,122 184 194 Due after five years through ten years 15,710 16,241 12,996 13,126 Due after ten years 3,362 3,142 1,524 1,528 Agency mortgage-backed securities 470,941 469,656 61,464 61,412 $ 603,491 $ 603,121 $ 76,168 $ 76,260 The following table represents a summary of investment securities that had an unrealized loss: September 30, 2017 Less than 12 months 12 months or more Total (in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Obligations of U.S. Government-sponsored enterprises $ 10,127 $ 14 $ — $ — $ 10,127 $ 14 Obligations of states and political subdivisions 4,907 244 — — 4,907 244 Agency mortgage-backed securities 332,037 2,721 11,307 469 343,344 3,190 $ 347,071 $ 2,979 $ 11,307 $ 469 $ 358,378 $ 3,448 December 31, 2016 Less than 12 months 12 months or more Total (in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Obligations of states and political subdivisions $ 21,361 $ 408 $ 3,553 $ 320 $ 24,914 $ 728 Agency mortgage-backed securities 267,734 4,084 12,883 493 280,617 4,577 $ 289,095 $ 4,492 $ 16,436 $ 813 $ 305,531 $ 5,305 The unrealized losses at both September 30, 2017 , and December 31, 2016 , were primarily attributable to changes in market interest rates since the securities were purchased. Management systematically evaluates investment securities for other-than-temporary declines in fair value on a quarterly basis. This analysis requires management to consider various factors, which include among other considerations (1) the present value of the cash flows expected to be collected compared to the amortized cost of the security, (2) duration and magnitude of the decline in value, (3) the financial condition of the issuer or issuers, (4) structure of the security, and (5) the intent to sell the security or whether it is more likely than not the Company would be required to sell the security before its anticipated recovery in market value. At September 30, 2017 , management performed its quarterly analysis of all securities with an unrealized loss and concluded no individual securities were other-than-temporarily impaired.

Loans

Loans	9 Months Ended
	Sep. 30, 2017
Receivables [Abstract]
Portfolio Loans	LOANS The loan portfolio is comprised of loans originated by the Company and loans that were acquired in connection with the Company’s acquisitions. These loans are accounted for using the guidance in the Accounting Standards Codification (ASC) section 310-30 and 310-20. Loans accounted for using ASC 310-30 are sometimes referred to as purchased credit impaired, or PCI, loans. The table below shows the loan portfolio composition including carrying value by segment of loans accounted for under ASC 310-30 (PCI loans) and loans not accounted for under this guidance, which includes our originated loans. (in thousands) September 30, 2017 December 31, 2016 Loans not accounted for as ASC 310-30 $ 3,948,676 $ 3,118,392 Loans accounted for as ASC 310-30 81,982 39,769 Total loans $ 4,030,658 $ 3,158,161 The following tables refer to loans not accounted for as ASC 310-30 loans. Below is a summary of loans by category at September 30, 2017 and December 31, 2016 : (in thousands) September 30, 2017 December 31, 2016 Commercial and industrial $ 1,861,285 $ 1,632,714 Real estate: Commercial - investor owned 737,986 544,808 Commercial - owner occupied 553,512 350,148 Construction and land development 302,182 194,542 Residential 339,377 240,760 Total real estate loans 1,933,057 1,330,258 Consumer and other 155,514 156,182 Loans, before unearned loan fees 3,949,856 3,119,154 Unearned loan fees, net (1,180 ) (762 ) Loans, including unearned loan fees $ 3,948,676 $ 3,118,392 A summary of the activity in the allowance for loan losses and the recorded investment in loans by class and category based on impairment methodology through September 30, 2017 , and at December 31, 2016 , is as follows: (in thousands) Commercial and industrial CRE - investor owned CRE - owner occupied Construction and land development Residential real estate Consumer and other Total Allowance for loan losses: Balance at December 31, 2016 $ 26,996 $ 3,420 $ 2,890 $ 1,304 $ 2,023 $ 932 $ 37,565 Provision (provision reversal) for loan losses 1,835 (105 ) (249 ) (11 ) (3 ) 66 1,533 Losses charged off (133 ) — — — (9 ) (29 ) (171 ) Recoveries 80 9 89 9 25 9 221 Balance at March 31, 2017 $ 28,778 $ 3,324 $ 2,730 $ 1,302 $ 2,036 $ 978 $ 39,148 Provision (provision reversal) for loan losses 2,955 (39 ) 354 (51 ) 451 (47 ) 3,623 Losses charged off (6,035 ) — (45 ) (5 ) (265 ) (39 ) (6,389 ) Recoveries 57 102 1 49 62 20 291 Balance at June 30, 2017 $ 25,755 $ 3,387 $ 3,040 $ 1,295 $ 2,284 $ 912 $ 36,673 Provision (provision reversal) for loan losses 1,126 376 245 305 299 71 2,422 Losses charged off (613 ) — (45 ) — (503 ) (75 ) (1,236 ) Recoveries 205 12 6 25 172 13 433 Balance at September 30, 2017 $ 26,473 $ 3,775 $ 3,246 $ 1,625 $ 2,252 $ 921 $ 38,292 (in thousands) Commercial and industrial CRE - investor owned CRE - owner occupied Construction and land development Residential real estate Consumer and other Total Balance September 30, 2017 Allowance for loan losses - Ending balance: Individually evaluated for impairment $ 2,063 $ 120 $ — $ 186 $ 48 $ — $ 2,417 Collectively evaluated for impairment 24,410 3,655 3,246 1,439 2,204 921 35,875 Total $ 26,473 $ 3,775 $ 3,246 $ 1,625 $ 2,252 $ 921 $ 38,292 Loans - Ending balance: Individually evaluated for impairment $ 7,646 $ 544 $ 1,513 $ 323 $ 667 $ — $ 10,693 Collectively evaluated for impairment 1,853,639 737,442 551,999 301,859 338,710 154,334 3,937,983 Total $ 1,861,285 $ 737,986 $ 553,512 $ 302,182 $ 339,377 $ 154,334 $ 3,948,676 Balance December 31, 2016 Allowance for loan losses - Ending balance: Individually evaluated for impairment $ 2,909 $ — $ — $ 155 $ — $ — $ 3,064 Collectively evaluated for impairment 24,087 3,420 2,890 1,149 2,023 932 34,501 Total $ 26,996 $ 3,420 $ 2,890 $ 1,304 $ 2,023 $ 932 $ 37,565 Loans - Ending balance: Individually evaluated for impairment $ 12,523 $ 430 $ 1,854 $ 1,903 $ 62 $ — $ 16,772 Collectively evaluated for impairment 1,620,191 544,378 348,294 192,639 240,698 155,420 3,101,620 Total $ 1,632,714 $ 544,808 $ 350,148 $ 194,542 $ 240,760 $ 155,420 $ 3,118,392 A summary of nonperforming loans individually evaluated for impairment by category at September 30, 2017 and December 31, 2016 , and the income recognized on impaired loans is as follows: September 30, 2017 (in thousands) Unpaid Recorded Recorded Allowance Total Related Allowance Average Commercial and industrial $ 13,981 $ 6,407 $ 1,044 $ 7,451 $ 2,020 $ 11,735 Real estate: Commercial - investor owned 562 259 285 544 120 542 Commercial - owner occupied — — — — — — Construction and land development 444 322 — 322 186 337 Residential 673 668 — 668 48 676 Consumer and other — — — — — — Total $ 15,660 $ 7,656 $ 1,329 $ 8,985 $ 2,374 $ 13,290 December 31, 2016 (in thousands) Unpaid Recorded Recorded Allowance Total Related Allowance Average Commercial and industrial $ 12,341 $ 566 $ 11,791 $ 12,357 $ 2,909 $ 4,489 Real estate: Commercial - investor owned 525 435 — 435 — 668 Commercial - owner occupied 225 231 — 231 — 227 Construction and land development 1,904 1,947 359 2,306 155 1,918 Residential 62 62 — 62 — 64 Consumer and other — — — — — — Total $ 15,057 $ 3,241 $ 12,150 $ 15,391 $ 3,064 $ 7,366 Three months ended September 30, Nine months ended September 30, (in thousands) 2017 2016 2017 2016 Total interest income that would have been recognized under original terms $ 306 $ 226 $ 961 $ 703 Total cash received and recognized as interest income on non-accrual loans 117 203 156 253 Total interest income recognized on accruing, impaired loans 8 32 55 63 There were no loans over 90 days past due and still accruing interest at September 30, 2017 or December 31, 2016 . The recorded investment in nonperforming loans by category at September 30, 2017 and December 31, 2016 , is as follows: September 30, 2017 (in thousands) Non-accrual Restructured, not on non-accrual Total Commercial and industrial $ 6,730 $ 721 $ 7,451 Real estate: Commercial - investor owned 544 — 544 Commercial - owner occupied — — — Construction and land development 322 — 322 Residential 668 — 668 Consumer and other — — — Total $ 8,264 $ 721 $ 8,985 December 31, 2016 (in thousands) Non-accrual Restructured, not on non-accrual Total Commercial and industrial $ 10,046 $ 2,311 $ 12,357 Real estate: Commercial - investor owned 435 — 435 Commercial - owner occupied 231 — 231 Construction and land development 2,286 20 2,306 Residential 62 — 62 Consumer and other — — — Total $ 13,060 $ 2,331 $ 15,391 There were no portfolio loans restructured during the three months ended September 30, 2017 and 2016. The recorded investment by category for the portfolio loans that have been restructured during the nine months ended September 30, 2017 and 2016 , is as follows: Nine months ended September 30, 2017 Nine months ended September 30, 2016 (in thousands, except for number of loans) Number of loans Pre-Modification Outstanding Recorded Balance Post-Modification Outstanding Recorded Balance Number of loans Pre-Modification Outstanding Recorded Balance Post-Modification Outstanding Recorded Balance Commercial and industrial 1 $ 676 $ 676 2 $ 2,341 $ 2,341 Real estate: Commercial - investor owned — — — 1 248 248 Commercial - owner occupied — — — — — — Construction and land development — — — 1 20 20 Residential — — — — — — Consumer and other — — — — — — Total 1 $ 676 $ 676 4 $ 2,609 $ 2,609 As of September 30, 2017 , the Company had $2.2 million in specific reserves allocated to $9.5 million of loans that have been restructured. During the three and nine months ended September 30, 2016 , there were no portfolio loans that subsequently defaulted. There were no portfolio loans restructured that subsequently defaulted during the three months ended September 30, 2017 . Portfolio loans restructured that subsequently defaulted during the nine months ended September 30, 2017 , are as follows: Nine months ended September 30, 2017 (in thousands, except for number of loans) Number of loans Recorded Balance Commercial and industrial 2 $ 343 Real estate: Commercial - investor owned — — Commercial - owner occupied — — Construction and land development — — Residential 1 5 Consumer and other — — Total 3 $ 348 The aging of the recorded investment in past due loans by portfolio class and category at September 30, 2017 and December 31, 2016 is shown below. September 30, 2017 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ 9,147 $ 283 $ 9,430 $ 1,851,855 $ 1,861,285 Real estate: Commercial - investor owned 986 — 986 737,000 737,986 Commercial - owner occupied 266 — 266 553,246 553,512 Construction and land development — 323 323 301,859 302,182 Residential 485 668 1,153 338,224 339,377 Consumer and other 1,542 — 1,542 152,792 154,334 Total $ 12,426 $ 1,274 $ 13,700 $ 3,934,976 $ 3,948,676 December 31, 2016 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ 334 $ 171 $ 505 $ 1,632,209 $ 1,632,714 Real estate: Commercial - investor owned — 175 175 544,633 544,808 Commercial - owner occupied 212 225 437 349,711 350,148 Construction and land development 355 1,528 1,883 192,659 194,542 Residential 91 — 91 240,669 240,760 Consumer and other 7 — 7 155,413 155,420 Total $ 999 $ 2,099 $ 3,098 $ 3,115,294 $ 3,118,392 The Company categorizes loans into risk categories based on relevant information about the ability of borrowers to service their debt, such as current financial information, payment experience, credit documentation, and current economic factors among other factors. This analysis is performed on a quarterly basis. The Company uses the following definitions for risk ratings: • Grades 1 , 2 , and 3 – Includes loans to borrowers with a continuous record of strong earnings, sound balance sheet condition and capitalization, ample liquidity with solid cash flow, and whose management team has experience and depth within their industry. • Grade 4 – Includes loans to borrowers with positive trends in profitability, satisfactory capitalization and balance sheet condition, and sufficient liquidity and cash flow. • Grade 5 – Includes loans to borrowers that may display fluctuating trends in sales, profitability, capitalization, liquidity, and cash flow. • Grade 6 – Includes loans to borrowers where an adverse change or perceived weakness has occurred, but may be correctable in the near future. Alternatively, this rating category may also include circumstances where the borrower is starting to reverse a negative trend or condition, or has recently been upgraded from a 7 , 8 , or 9 rating. • Grade 7 – Watch credits are borrowers that have experienced financial setback of a nature that is not determined to be severe or influence ‘ongoing concern’ expectations. Although possible, no loss is anticipated, due to strong collateral and/or guarantor support. • Grade 8 – Substandard credits will include those borrowers characterized by significant losses and sustained downward trends in balance sheet condition, liquidity, and cash flow. Repayment reliance may have shifted to secondary sources. Collateral exposure may exist and additional reserves may be warranted. • Grade 9 – Doubtful credits include borrowers that may show deteriorating trends that are unlikely to be corrected. Collateral values may appear insufficient for full recovery, therefore requiring a partial charge-off, or debt renegotiation with the borrower. The borrower may have declared bankruptcy or bankruptcy is likely in the near term. All doubtful rated credits will be on non-accrual. The recorded investment by risk category of the loans by portfolio class and category at September 30, 2017 , which is based upon the most recent analysis performed, and December 31, 2016 is as follows: September 30, 2017 (in thousands) Pass (1-6) Watch (7) Substandard (8) Doubtful (9) Total Commercial and industrial $ 1,708,153 $ 90,885 $ 62,247 $ — $ 1,861,285 Real estate: Commercial - investor owned 720,912 12,592 4,482 — 737,986 Commercial - owner occupied 513,939 33,249 6,324 — 553,512 Construction and land development 298,613 2,558 1,011 — 302,182 Residential 328,434 3,989 6,954 — 339,377 Consumer and other 153,113 375 846 — 154,334 Total $ 3,723,164 $ 143,648 $ 81,864 $ — $ 3,948,676 December 31, 2016 (in thousands) Pass (1-6) Watch (7) Substandard (8) Doubtful (9) Total Commercial and industrial $ 1,499,114 $ 57,416 $ 76,184 $ — $ 1,632,714 Real estate: Commercial - investor owned 530,494 10,449 3,865 — 544,808 Commercial - owner occupied 306,658 39,249 4,241 — 350,148 Construction and land development 185,505 6,575 2,462 — 194,542 Residential 233,479 2,997 4,284 — 240,760 Consumer and other 153,984 — 1,436 — 155,420 Total $ 2,909,234 $ 116,686 $ 92,472 $ — $ 3,118,392

Purchased Credit Impaired ("PCI

Purchased Credit Impaired ("PCI") Loans	9 Months Ended
	Sep. 30, 2017
Receivables [Abstract]
Purchase Credit Impaired (PCI) Loans	Below is a summary of PCI loans by category at September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 (in thousands) Weighted- Average Risk Rating 1 Recorded Investment PCI Loans Weighted- Average Risk Rating 1 Recorded Investment PCI Loans Commercial and industrial 6.26 $ 3,676 5.87 $ 3,523 Real estate: Commercial - investor owned 7.29 45,865 6.95 8,162 Commercial - owner occupied 6.50 11,786 6.39 11,863 Construction and land development 5.93 7,927 5.80 4,365 Residential 6.05 12,661 5.64 11,792 Total real estate loans 78,239 36,182 Consumer and other 2.99 67 1.64 64 Purchased credit impaired loans $ 81,982 $ 39,769 1 Risk ratings are based on the borrower's contractual obligation, which is not reflective of the purchase discount. The aging of the recorded investment in past due PCI loans by portfolio class and category at September 30, 2017 and December 31, 2016 is shown below: September 30, 2017 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ — $ — $ — $ 3,676 $ 3,676 Real estate: Commercial - investor owned 429 396 825 45,040 45,865 Commercial - owner occupied 46 909 955 10,831 11,786 Construction and land development — 478 478 7,449 7,927 Residential 748 992 1,740 10,921 12,661 Consumer and other — — — 67 67 Total $ 1,223 $ 2,775 $ 3,998 $ 77,984 $ 81,982 December 31, 2016 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ — $ — $ — $ 3,523 $ 3,523 Real estate: Commercial - investor owned — — — 8,162 8,162 Commercial - owner occupied — — — 11,863 11,863 Construction and land development — — — 4,365 4,365 Residential 169 51 220 11,572 11,792 Consumer and other — — — 64 64 Total $ 169 $ 51 $ 220 $ 39,549 $ 39,769 The following table is a rollforward of PCI loans, net of the allowance for loan losses, for the nine months ended September 30, 2017 and 2016 . (in thousands) Contractual Cashflows Non-accretable Difference Accretable Yield Carrying Amount Balance December 31, 2016 $ 66,003 $ 18,902 $ 13,176 $ 33,925 Acquisitions 68,763 14,296 5,312 49,155 Principal reductions and interest payments (16,319 ) — — (16,319 ) Accretion of loan discount — — (5,473 ) 5,473 Changes in contractual and expected cash flows due to remeasurement 11,110 (702 ) 3,776 8,036 Reductions due to disposals (6,393 ) (1,612 ) (1,595 ) (3,186 ) Balance September 30, 2017 $ 123,164 $ 30,884 $ 15,196 $ 77,084 Balance December 31, 2015 $ 116,689 $ 26,765 $ 25,341 $ 64,583 Principal reductions and interest payments (20,417 ) — — (20,417 ) Accretion of loan discount — — (4,984 ) 4,984 Changes in contractual and expected cash flows due to remeasurement 9,194 975 (1,043 ) 9,262 Reductions due to disposals (27,888 ) (6,779 ) (3,713 ) (17,396 ) Balance September 30, 2016 $ 77,578 $ 20,961 $ 15,601 $ 41,016 The accretable yield is recognized in interest income over the estimated life of the acquired loans using the effective yield method. Outstanding customer balances on PCI loans were $107.8 million and $54.6 million as of September 30, 2017 , and December 31, 2016 , respectively.

Commitments

Commitments	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments	COMMITMENTS AND CONTINGENCIES The Company issues financial instruments with off balance sheet risk in the normal course of the business of meeting the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit. These instruments may involve, to varying degrees, elements of credit and interest rate risk in excess of the amounts recognized in the consolidated balance sheets. The Company’s extent of involvement and maximum potential 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 these instruments. The Company uses the same credit policies in making commitments and conditional obligations as it does for financial instruments included on its consolidated balance sheets. At September 30, 2017 , the amount of unadvanced commitments on impaired loans was insignificant. The contractual amounts of off-balance-sheet financial instruments as of September 30, 2017 , and December 31, 2016 , are as follows: (in thousands) September 30, 2017 December 31, 2016 Commitments to extend credit $ 1,263,809 $ 1,075,170 Letters of credit 74,007 78,954 Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments usually have fixed expiration dates or other termination clauses, may have significant usage restrictions, and may require payment of a fee. Of the total commitments to extend credit at September 30, 2017 , and December 31, 2016 , approximately $113 million and $90 million , respectively, represent fixed rate loan commitments. Since certain of the commitments may expire without being drawn upon or may be revoked, the total commitment amounts do not necessarily represent future cash requirements. The Company evaluates each customer’s credit worthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by the Company upon extension of credit, is based on management’s credit evaluation of the borrower. Collateral held varies, but may include accounts receivable, inventory, premises and equipment, and real estate. Other liabilities includes $0.4 million for estimated losses attributable to the unadvanced commitments at September 30, 2017 , and December 31, 2016 . Standby letters of credit are conditional commitments issued by the Company to guarantee the performance or payment of a customer to a third party. These standby letters of credit are issued to support contractual obligations of the Company’s customers. The credit risk involved in issuing letters of credit is essentially the same as the risk involved in extending loans to customers. As of September 30, 2017 , the approximate remaining term of standby letters of credit range from 1 month to 4 years . Contingencies The Company and its subsidiaries are, from time to time, parties to various legal proceedings arising out of their businesses. Management believes there are no such proceedings pending or threatened against the Company or its subsidiaries which, if determined adversely, would have a material adverse effect on the business, consolidated financial condition, results of operations or cash flows of the Company or any of its subsidiaries.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	DERIVATIVE FINANCIAL INSTRUMENTS The Company is a party to various derivative financial instruments that are used in the normal course of business to meet the needs of its clients and as part of its risk management activities. These instruments include interest rate swaps and option contracts and foreign exchange forward contracts. The Company does not enter into derivative financial instruments for trading purposes. Risk Management Instruments. At September 30, 2017 , the company has no derivative contracts used to manage risk. Client-Related Derivative Instruments. The Company enters into interest rate swaps to allow customers to hedge changes in fair value of certain loans while maintaining a variable rate loan on its own books. The Company also enters into foreign exchange forward contracts with clients, and enters into offsetting foreign exchange forward contracts with established financial institution counterparties. The table below summarizes the notional amounts and fair values of the client-related derivative instruments: Asset Derivatives (Other Assets) Liability Derivatives (Other Liabilities) Notional Amount Fair Value Fair Value (in thousands) September 30, December 31, September 30, December 31, September 30, December 31, Non-designated hedging instruments Interest rate swap contracts $ 270,542 $ 124,322 $ 1,902 $ 982 $ 1,902 $ 982 Foreign exchange forward contracts 1,376 3,034 1,376 3,034 1,376 3,034 Changes in the fair value of client-related derivative instruments are recognized currently in operations. For the three and nine months ended September 30, 2017 and 2016 , the gains and losses offset each other due to the Company's hedging of the client swaps and foreign exchange contracts with other bank counterparties.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS Below is a description of certain assets and liabilities measured at fair value. The following table summarizes financial instruments measured at fair value on a recurring basis as of September 30, 2017 and December 31, 2016 , segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: September 30, 2017 (in thousands) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Fair Value Assets Securities available for sale Obligations of U.S. Government-sponsored enterprises $ — $ 100,123 $ — $ 100,123 Obligations of states and political subdivisions — 33,341 — 33,341 Residential mortgage-backed securities — 469,657 — 469,657 Total securities available for sale $ — $ 603,121 $ — $ 603,121 State tax credits held for sale — — 1,274 1,274 Derivative financial instruments — 3,278 — 3,278 Total assets $ — $ 606,399 $ 1,274 $ 607,673 Liabilities Derivative financial instruments $ — $ 3,278 $ — $ 3,278 Total liabilities $ — $ 3,278 $ — $ 3,278 December 31, 2016 (in thousands) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Fair Value Assets Securities available for sale Obligations of U.S. Government-sponsored enterprises $ — $ 107,660 $ — $ 107,660 Obligations of states and political subdivisions — 33,542 3,089 36,631 Residential mortgage-backed securities — 316,506 — 316,506 Total securities available for sale $ — $ 457,708 $ 3,089 $ 460,797 State tax credits held for sale — — 3,585 3,585 Derivative financial instruments — 4,016 — 4,016 Total assets $ — $ 461,724 $ 6,674 $ 468,398 Liabilities Derivative financial instruments $ — $ 4,016 $ — $ 4,016 Total liabilities $ — $ 4,016 $ — $ 4,016 • Securities available for sale . Securities classified as available for sale are reported at fair value utilizing Level 2 and Level 3 inputs. Fair values for Level 2 securities are based upon dealer quotes, market spreads, the U.S. Treasury yield curve, trade execution data, market consensus prepayment speeds, credit information and the bond's terms and conditions at the security level. At September 30, 2017 , there were no Level 3 Auction Rate Securities. Auction Rate Securities at September 30, 2017 were valued using a Level 2 pricing source similar to our other securities available for sale. • State tax credits held for sale. At September 30, 2017 , of the $35.3 million of state tax credits held for sale on the condensed consolidated balance sheet, approximately $1.3 million were carried at fair value. The remaining $34.0 million of state tax credits were accounted for at cost. The Company is not aware of an active market that exists for the 10 -year streams of state tax credit financial instruments. However, the Company’s principal market for these tax credits consists of Missouri state residents who buy these credits and local and regional accounting firms who broker them. As such, the Company employed a discounted cash flow analysis (income approach) to determine the fair value. The fair value measurement is calculated using an internal valuation model with market data including discounted cash flows based upon the terms and conditions of the tax credits. If the underlying project remains in compliance with the various federal and state rules governing the tax credit program, each project will generate about 10 years of tax credits. The inputs to the discounted cash flow calculation include: the amount of tax credits generated each year, the anticipated sale price of the tax credit, the timing of the sale and a discount rate. The discount rate is estimated using the LIBOR swap curve at a point equal to the remaining life in years of credits plus a 205 basis point spread. With the exception of the discount rate, the other inputs to the fair value calculation are observable and readily available. The discount rate is considered a Level 3 input because it is an “unobservable input” and is based on the Company’s assumptions. An increase in the discount rate utilized would generally result in a lower estimated fair value of the tax credits. Alternatively, a decrease in the discount rate utilized would generally result in a higher estimated fair value of the tax credits. The remaining state tax credits carried at fair value are expected to be sold within the next several quarters. The state tax credit assets are reported as Level 3 assets. • Derivatives . Derivatives are reported at fair value utilizing Level 2 inputs. The Company obtains counterparty quotations to value its interest rate swaps. In addition, the Company validates the counterparty quotations with third party valuation sources. Derivatives with negative fair values are included in Other liabilities in the consolidated balance sheets. Derivatives with positive fair value are included in Other assets in the consolidated balance sheets. Level 3 financial instruments The following table presents the changes in Level 3 financial instruments measured at fair value on a recurring basis as of September 30, 2017 and 2016 . • Purchases, sales, issuances and settlements . There were no Level 3 purchases during the quarters ended September 30, 2017 or 2016 . • Transfers in and/or out of Level 3 . There were no Level 3 transfers during the quarters ended September 30, 2017 and 2016 . Securities available for sale, at fair value Three months ended September 30, Nine months ended September 30, (in thousands) 2017 2016 2017 2016 Beginning balance $ — $ 3,093 $ 3,089 $ 3,077 Total gains: Included in other comprehensive income — 1 4 17 Purchases, sales, issuances and settlements: Purchases — — — — Transfer in and/or out of Level 3 — — (3,093 ) — Ending balance $ — $ 3,094 $ — $ 3,094 Change in unrealized gains relating to assets still held at the reporting date $ — $ 1 $ — $ 17 State tax credits held for sale Three months ended September 30, Nine months ended September 30, (in thousands) 2017 2016 2017 2016 Beginning balance $ 1,274 $ 4,774 $ 3,585 $ 5,941 Total gains: Included in earnings — 27 49 144 Purchases, sales, issuances and settlements: Sales — — (2,360 ) (1,284 ) Ending balance $ 1,274 $ 4,801 $ 1,274 $ 4,801 Change in unrealized gains (losses) relating to assets still held at the reporting date $ — $ 27 $ (655 ) $ (237 ) From time to time, the Company measures certain assets at fair value on a nonrecurring basis. These include assets that are measured at the lower of cost or fair value that were recognized at fair value below cost at the end of the period. The following table presents financial instruments and non-financial assets measured at fair value on a non-recurring basis as of September 30, 2017 . (1) (1) (1) (1) (in thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant (Level 3) Total losses for the three Total losses for the nine Impaired loans $ 2,743 $ — $ — $ 2,743 $ 613 $ 5,876 Other real estate 26 — — 26 38 38 Total $ 2,769 $ — $ — $ 2,769 $ 651 $ 5,914 (1) The amounts represent only balances measured at fair value during the period and still held as of the reporting date. Impaired loans are reported at the fair value of the underlying collateral for collateral dependent loans. Fair values for impaired loans are obtained from current appraisals by qualified licensed appraisers or independent valuation specialists. At September 30, 2017, impaired loans measured on a non-recurring basis had a principal balance of $3.9 million , with a valuation allowance of $1.2 million . Other real estate owned is adjusted to fair value upon foreclosure of the underlying loan. Subsequently, foreclosed assets are carried at the lower of carrying value or fair value less costs to sell. Fair value of other real estate is based upon the current appraised values of the properties as determined by qualified licensed appraisers and the Company’s judgment of other relevant market conditions. Certain state tax credits are reported at cost. Following is a summary of the carrying amounts and fair values of the Company’s financial instruments on the consolidated balance sheets at September 30, 2017 and December 31, 2016 . September 30, 2017 December 31, 2016 (in thousands) Carrying Amount Estimated fair value Carrying Amount Estimated fair value Balance sheet assets Cash and due from banks $ 76,777 $ 76,777 $ 54,288 $ 54,288 Federal funds sold 1,155 1,155 446 446 Interest-bearing deposits 107,821 107,821 145,048 145,048 Securities available for sale 603,121 603,121 460,797 460,797 Securities held to maturity 76,168 76,260 80,463 79,639 Other investments, at cost 29,436 29,436 14,840 14,840 Loans held for sale 6,411 6,411 9,562 9,562 Derivative financial instruments 3,278 3,278 4,016 4,016 Loans, net 3,987,467 4,009,071 3,114,752 3,125,701 State tax credits, held for sale 35,291 37,781 38,071 41,264 Accrued interest receivable 14,213 14,213 11,117 11,117 Balance sheet liabilities Deposits 4,059,211 4,057,561 3,233,361 3,232,414 Subordinated debentures and notes 118,093 100,062 105,540 86,052 Federal Home Loan Bank advances 248,868 249,168 — — Other borrowings 219,104 219,012 276,980 276,905 Derivative financial instruments 3,278 3,278 4,016 4,016 Accrued interest payable 2,007 2,007 1,105 1,105 For information regarding the methods and assumptions used to estimate the fair value of each class of financial instruments for which it is practical to estimate such value, refer to Note 19 – Fair Value Measurements in the Company's Annual Report on Form 10 -K for the year ended December 31, 2016 . The following table presents the level in the fair value hierarchy for the estimated fair values of only the Company’s financial instruments that are not already presented on the condensed consolidated balance sheets at fair value at September 30, 2017 , and December 31, 2016 . Estimated Fair Value Measurement at Reporting Date Using Balance at (in thousands) Level 1 Level 2 Level 3 Financial Assets: Securities held to maturity $ — $ 76,260 $ — $ 76,260 Portfolio loans, net — — 4,009,071 4,009,071 State tax credits, held for sale — — 36,508 36,508 Financial Liabilities: Deposits 3,442,015 — 615,546 4,057,561 Subordinated debentures and notes — 100,062 — 100,062 Federal Home Loan Bank advances — 249,168 — 249,168 Other borrowings — 219,012 — 219,012 Estimated Fair Value Measurement at Reporting Date Using Balance at December 31, 2016 (in thousands) Level 1 Level 2 Level 3 Financial Assets: Securities held to maturity $ — $ 79,639 $ — $ 79,639 Portfolio loans, net — — 3,125,701 3,125,701 State tax credits, held for sale — — 37,679 37,679 Financial Liabilities: Deposits 2,760,202 — 472,212 3,232,414 Subordinated debentures and notes — 86,052 — 86,052 Other borrowings — 276,905 — 276,905

New Authoritative Accounting Gu

New Authoritative Accounting Guidance	9 Months Ended
	Sep. 30, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Authoritative Accounting Guidance	NEW AUTHORITATIVE ACCOUNTING GUIDANCE Financial Accounting Standards Board (the "FASB") Accounting Standards Update ( the "ASU") 2017-12 "Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities" In August 2017, the FASB issued ASU 2017-12, "Targeted Improvement to Accounting for Hedging Activities". The objective of ASU 2017-12 is to improve the financial reporting of hedging relationships by better aligning an entity's risk management activity with the economic objectives in undertaking those activities. In addition, the amendments in this update simplify the application of hedge accounting for preparers of financial statements, as well as improve the understandability of an entity's risk management activities being conveyed to financial statement users. The new guidance becomes effective for periods beginning after December 15, 2018. Early adoption is permitted. The Company is currently evaluating the new guidance and timing of adoption to determine the impact this standard may have on its financial statements. FASB ASU 2017-09 "Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting" In May 2017, the FASB issued ASU 2017-09, "Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting" which amends the scope of modification accounting for share-based payment awards. The amendments provide guidance on the types of changes to the terms or conditions of share-based payment awards to which an entity would be required to apply modification accounting with an intent to simplify the accounting under ASC 718. The amendments are effective for public business entities for annual periods beginning after December 15, 2017, including interim periods within those annual periods, with early adoption being permitted. The Company has evaluated the new guidance and does not expect it to have a material impact on the Company's consolidated financial statements. FASB ASU 2017-08 "Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities" In March 2017, the FASB issued ASU 2017-08, "Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20)" which shortens the amortization period of certain callable debt securities held at a premium to the earliest call date. The amendments are effective for public business entities for annual periods beginning after December 15, 2018, including interim periods within those annual periods, with early adoption being permitted. The Company is currently evaluating the new guidance and has not determined the impact this standard may have on its financial statements. FASB ASU 2017-04 "Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment" In January 2017, the FASB issued ASU 2017-04 "Simplifying the Test for Goodwill Impairment" which simplifies the measurement of goodwill impairment by removing step two of the goodwill impairment test. The new guidance requires goodwill impairment to be measured as the amount by which a reporting unit's carrying value exceeds its fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The amendments should be applied on a prospective basis. The guidance becomes effective for testing periods beginning after January 1, 2017. The new guidance will be applied in the Company's 2017 annual impairment testing and is expected to not have an impact on the Company's consolidated financial statements. FASB ASU 2016-15 "Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments" In August 2016, the FASB issued ASU 2016-15, "Statement of Cash Flows (Topic 230)" which addresses changes to reduce the presentation diversity of certain cash receipts and cash payments in the statement of cash flows, including debt prepayment or extinguishment costs, settlement of certain debt instruments, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, and distributions received from equity method investees. The guidance becomes effective for fiscal years beginning afte r December 15, 2017, in cluding interim periods within those fiscal years, with early adoption permitted. An entity that elects early adoption must adopt all of the amendments in the same period. The new standard will be applied retrospectively, but may be applied prospectively if retrospective application would be impracticable. The Company is currently evaluating the new guidance and has not determined the impact this standard may have on its consolidated statement of cash flows. FASB ASU 2016-13 "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments" In June 2016, the FASB issued ASU 2016-13, "Financial Instruments (Topic 326)" which changes the methodology for evaluating impairment of most financial instruments. The ASU replaces the currently used incurred loss model with a forward-looking expected loss model, which will generally result in a more timely recognition of losses. The guidance becomes effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is currently evaluating the new guidance and has not determined the impact this standard may have on its financial statements. FASB ASU 2016-02 "Leases (Topic 842)" In February 2016, the FASB issued ASU 2016-02, "Leases (Topic 842)" which requires organizations that lease assets ("lessees") to recognize the assets and liabilities for the rights and obligations created by leases with terms of more than 12 months. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee remains dependent on its classification as a finance or operating lease. The criteria for determining whether a lease is a finance or operating lease has not been significantly changed by this ASU. The ASU also requires additional disclosure of the amount, timing, and uncertainty of cash flows arising from leases, including qualitative and quantitative requirements. The guidance becomes effective for periods beginning after December 15, 2018, including interim periods therein. Early adoption will be permitted. The Company is currently evaluating the new guidance and has not determined the impact this standard may have on its consolidated balance sheets. FASB ASU 2016-01 "Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities" In January 2016, the FASB issued ASU 2016-01, "Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities." ASU 2016-01 requires equity investments to be measured at fair value through earnings, and eliminates the available-for-sale classification for equity securities with readily determinable fair values. For financial liabilities where the fair value option has been elected, changes in fair value due to instrument-specific credit risk must be recognized in other comprehensive income. When measuring the fair value of financial instruments at amortized cost, the exit price must be used for disclosure purposes. The ASU also requires that financial assets and liabilities be presented separately in the notes to the financial statements. This ASU becomes effective for fiscal years beginning after December 15, 2017, including interim periods therein. Early adoption is permitted with some exceptions. The Company has evaluated its applicable equity investments and determined that they qualify for the measurement exception which allows those investments to be measured at their cost minus impairment. Any valuation adjustments will be recorded prospectively through net income, and the related disclosure will be included in the Notes to the Consolidated Financial Statements. FASB ASU 2014-09, "Revenue from Contracts with Customers (Topic 606)" In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers”. The objective of ASU 2014-09 is to establish a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and will supersede most of the existing revenue recognition guidance, including industry-specific guidance. The core principle of ASU 2014-09 is that an entity recognizes 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. In applying the new guidance, an entity will (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the contract’s performance obligations; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. ASU 2014-09 applies to all contracts with customers except those that are within the scope of other topics in the FASB Accounting Standards Codification. The new guidance was originally effective for annual reporting periods (including interim periods within those periods) beginning after December 15, 2016 for public companies. In August 2015, the FASB issued ASU 2015-14, which defers the effective date of this guidance to annual reporting periods beginning after December 15, 2017 for public companies, and permits early adoption on a limited basis. The Company has conducted its initial assessment and is currently evaluating contracts to assess and quantify accounting methodology changes resulting from the adoption of ASU 2014-09. The majority of the Company’s revenues are derived from loans which are excluded from the new standard; therefore, the new guidance is not expected to have a material impact on the Company's consolidated financial position, results of operations or cash flows. The Company has decided upon the modified retrospective adoption method.

Summary of Significant Accoun20

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Business and Consolidation	Basis of Financial Statement Presentation The condensed consolidated financial statements of the Company and its subsidiaries have been prepared in accordance with the accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. The condensed consolidated financial statements include the accounts of the Company and its subsidiaries, all of which are wholly owned. All intercompany accounts and transactions have been eliminated. In 2017, the Company changed its presentation of loans on the face of the Condensed Consolidated Balance Sheets to combine originated loans with purchased loans. See Note 5 - Loans for more information. The Company also changed its presentation of the Noninterest Income section on the face of the Condensed Consolidated Statements of Operations to separate card services revenue out of miscellaneous income. The Company adopted Accounting Standards Update (ASU) 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting during the first quarter of 2017. Among other elements, the ASU requires an entity to recognize all excess tax benefits and deficiencies related to stock-based compensation expense as income tax expense or benefit in the statements of operations. The ASU requires adjustments be reflected as of the beginning of the fiscal year of adoption and as a result, $5.2 million of previously recognized excess tax benefits were reclassified from Additional paid in capital to Retained earnings during the first quarter of 2017. The adoption resulted in a decrease to income tax expense of $1.8 million for the nine months ended September 30, 2017 . Excess tax benefits related to stock compensation are presented as a cash inflow from operating activities for the nine months ended September 30, 2017 due to the prospective adoption of employee share-based payment guidance in 2017. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Acquisitions Acquisitions and business combinations are accounted for using the acquisition method of accounting. The assets and liabilities of the acquired entities have been recorded at their estimated fair values at the date of acquisition. Goodwill represents the excess of the purchase price over the fair value of net assets acquired, including the amount assigned to identifiable intangible assets. The purchase price allocation process requires an estimation of the fair values of the assets acquired and the liabilities assumed. When a business combination agreement provides for an adjustment to the cost of the combination contingent on future events, the Company includes an estimate of the acquisition-date fair value as part of the cost of the combination. To determine the fair values, the Company relies on third party valuations, such as appraisals, or internal valuations based on discounted cash flow analyses or other valuation techniques. The results of operations of the acquired business are included in the Company's consolidated financial statements from the date of acquisition. Merger-related costs are costs the Company incurs to effect a business combination. In 2017, the Company changed its presentation of Merger related expenses as a separate component of Noninterest expenses on the Condensed Consolidated Statements of Operations. Merger related expenses include costs directly related to merger or acquisition activity and include legal and professional fees, system consolidation and conversion costs, and compensation costs such as severance and retention incentives for employees impacted by acquisition activity. The Company accounts for merger-related costs as expenses in the periods in which the costs are incurred and the services are received. Purchased Credit Impaired ("PCI") Loans Purchased credit impaired ("PCI") loans were acquired in a business combination or transaction that have evidence of deterioration of credit quality since origination and for which it is probable, at acquisition, that the Company will be unable to collect all contractually required payments receivable. PCI loans were initially recorded at fair value (as determined by the present value of expected future cash flows) with no valuation allowance. The difference between the undiscounted cash flows expected at acquisition and the investment in the loans, or the “accretable yield,” is recognized as interest income on a level-yield method over the life of the loans. Contractually required payments for interest and principal that exceed the undiscounted cash flows expected at acquisition, or the “nonaccretable difference,” are not recognized as a yield adjustment or as a loss accrual or a valuation allowance. The Company aggregates individual loans with common risk characteristics into pools of loans. Increases in expected cash flows subsequent to the initial investment are recognized prospectively through adjustment of the yield on the loans over their remaining lives. Decreases in expected cash flows due to an inability to collect contractual cash flows are recognized as impairment through the provision for loan losses account. Any allowance for loan loss on these pools reflect only losses incurred after the acquisition. Disposals of loans, including sales of loans, paydowns, payments in full or foreclosures result in the removal or reduction of the loan from the loan pool. PCI loans are generally considered accruing and performing, as the loans accrete income over the estimated life of the loan, in circumstances where cash flows are reasonably estimable by management. Accordingly, PCI loans that could be contractually past due could be considered to be accruing and performing. If the timing and amount of future cash flows is not reasonably estimable or is less than the carrying value, the loans may be classified as nonaccrual loans and the purchase price discount on those loans is not recorded as interest income until the timing and amount of future cash flows can be reasonably estimable. Allowance for Loan Losses on PCI Loans The Company updates its cash flow projections for purchased credit-impaired loans on a periodic basis. Assumptions utilized in this process include projections related to probability of default, loss severity, prepayment, extensions and recovery lag. Projections related to probability of default and prepayment are calculated utilizing a loan migration analysis and management’s assessment of loss exposure including the fair value of underlying collateral. The loan migration analysis is a matrix that specifies the probability of a loan pool transitioning into a particular delinquency or liquidation state given its current performance at the measurement date. Loss severity factors are based upon industry data and historical experience. Any decreases in expected cash flows after the acquisition date and subsequent measurement periods are recognized by recording an impairment in allowance for loan losses through a provision for loan losses.
Available-for-sale Securities	Management systematically evaluates investment securities for other-than-temporary declines in fair value on a quarterly basis. This analysis requires management to consider various factors, which include among other considerations (1) the present value of the cash flows expected to be collected compared to the amortized cost of the security, (2) duration and magnitude of the decline in value, (3) the financial condition of the issuer or issuers, (4) structure of the security, and (5) the intent to sell the security or whether it is more likely than not the Company would be required to sell the security before its anticipated recovery in market value. At September 30, 2017 , management performed its quarterly analysis of all securities with an unrealized loss and concluded no individual securities were other-than-temporarily impaired.

Acquisitions & Divestitures (Ta

Acquisitions & Divestitures (Tables)	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	The following table presents the assets acquired and liabilities assumed of JCB as of February 10, 2017 , and their preliminary estimated fair values: (in thousands) As Recorded by JCB Adjustments As Recorded by EFSC Assets acquired: Cash and cash equivalents $ 33,739 $ — $ 33,739 Interest-bearing deposits 1,715 — 1,715 Securities 148,670 — 148,670 Portfolio loans, net 685,905 (11,094 ) (a) 674,811 Other real estate owned 6,762 (5,082 ) (b) 1,680 Other investments 2,695 — 2,695 Fixed assets, net 21,780 (3,325 ) (c) 18,455 Accrued interest receivable 2,794 — 2,794 Goodwill 7,806 (7,806 ) (d) — Other intangible assets 25 11,489 (e) 11,514 Deferred tax assets 4,634 3,991 (f) 8,625 Other assets 19,107 (296 ) (g) 18,811 Total assets acquired $ 935,632 $ (12,123 ) $ 923,509 Liabilities assumed: Deposits $ 764,539 $ 629 (h) $ 765,168 Other borrowings 55,430 681 (i) 56,111 Trust preferred securities 12,887 (382 ) (j) 12,505 Accrued interest payable 653 — 653 Other liabilities 5,006 65 (k) 5,071 Total liabilities assumed $ 838,515 $ 993 $ 839,508 Net assets acquired $ 97,117 $ (13,116 ) $ 84,001 Consideration paid: Cash $ 29,283 Common stock 141,729 Total consideration paid $ 171,012 Goodwill $ 87,011 (a) Fair value adjustments based on the Company’s evaluation of the acquired loan portfolio, write-off of net deferred loan costs, reclassification from other real estate owned, and elimination of the allowance for loan losses recorded by JCB. The fair value discount recorded to the loan portfolio is $24.7 million . (b) Fair value adjustment based on the Company’s evaluation of the acquired other real estate portfolio, and reclassification to portfolio loans. (c) Fair value adjustments based on the Company’s evaluation of the acquired premises and equipment. A decrease of $1.1 million was recorded during the third quarter of 2017 due to continued refinement of the purchase accounting calculations. (d) Eliminate JCB’s recorded goodwill. (e) Record the core deposit intangible asset on the acquired core deposit accounts. Amount to be amortized using a sum of years digits method over a 10 year useful life. (f) Adjustment for deferred taxes at the acquisition date. The adjustment decreased by $0.2 million during the current quarter due to continued refinement of the purchase accounting calculations. (g) Fair value adjustment based on evaluation of other assets. (h) Fair value adjustment to time deposits based on current interest rates. (i) Fair value adjustment to the FHLB advances based on current interest rates. (j) Fair value adjustment based on the Company's evaluation of the trust preferred securities. (k) A decrease of $0.1 million was recorded during the current quarter due to further refinement of the purchase accounting calculations.
Business Acquisition, Pro Forma Information [Table Text Block]	The following table provides the unaudited pro forma information for the results of operations for the nine months ended September 30, 2017 and 2016 , as if the acquisition had occurred on January 1, 2016. The pro forma results combine the historical results of JCB with the Company’s Consolidated Statements of Income, adjusted for the impact of the application of the acquisition method of accounting including loan discount accretion, intangible assets amortization, and deposit and trust preferred securities premium accretion, net of taxes. The pro forma results have been prepared for comparative purposes only and are not necessarily indicative of the results that would have been obtained had the acquisition actually occurred on January 1, 2016. No assumptions have been applied to the pro forma results of operations regarding possible revenue enhancements, expense efficiencies or asset dispositions. Only the acquisition related expenses that have been incurred as of September 30, 2017 are included in net income in the table below. Pro Forma Nine months ended September 30, (in thousands, except per share data) 2017 2016 Total revenues (net interest income plus noninterest income) $ 155,907 $ 146,623 Net income 40,151 42,298 Diluted earnings per common share 1.70 1.80

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Summary of Per Common Share Data and Amounts	The following table presents a summary of per common share data and amounts for the periods indicated. Three months ended September 30, Nine months ended September 30, (in thousands, except per share data) 2017 2016 2017 2016 Net income as reported $ 16,315 $ 11,832 $ 40,661 $ 35,209 Weighted average common shares outstanding 23,324 19,997 22,914 20,002 Additional dilutive common stock equivalents 250 227 295 229 Weighted average diluted common shares outstanding 23,574 20,224 23,209 20,231 Basic earnings per common share: $ 0.70 $ 0.59 $ 1.77 $ 1.76 Diluted earnings per common share: $ 0.69 $ 0.59 $ 1.75 $ 1.74

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale and Held-to-Maturity Securities Reconciliation	The following table presents the amortized cost, gross unrealized gains and losses and fair value of securities available for sale and held to maturity: September 30, 2017 (in thousands) Amortized Cost Gross Gross Fair Value Available for sale securities: Obligations of U.S. Government-sponsored enterprises $ 99,866 $ 271 $ (14 ) $ 100,123 Obligations of states and political subdivisions 32,684 887 (229 ) 33,342 Agency mortgage-backed securities 470,941 1,760 (3,045 ) 469,656 Total securities available for sale $ 603,491 $ 2,918 $ (3,288 ) $ 603,121 Held to maturity securities: Obligations of states and political subdivisions $ 14,704 $ 159 $ (15 ) $ 14,848 Agency mortgage-backed securities 61,464 93 (145 ) 61,412 Total securities held to maturity $ 76,168 $ 252 $ (160 ) $ 76,260 December 31, 2016 (in thousands) Amortized Cost Gross Gross Fair Value Available for sale securities: Obligations of U.S. Government-sponsored enterprises $ 107,312 $ 348 $ — $ 107,660 Obligations of states and political subdivisions 36,486 630 (485 ) 36,631 Agency mortgage-backed securities 319,345 1,101 (3,940 ) 316,506 Total securities available for sale $ 463,143 $ 2,079 $ (4,425 ) $ 460,797 Held to maturity securities: Obligations of states and political subdivisions $ 14,759 $ 11 $ (242 ) $ 14,528 Agency mortgage-backed securities 65,704 45 (638 ) 65,111 Total securities held to maturity $ 80,463 $ 56 $ (880 ) $ 79,639
Schedule of Available-for-sale and Held-to-Maturity Securities Reconciliation	The following table presents the amortized cost, gross unrealized gains and losses and fair value of securities available for sale and held to maturity: September 30, 2017 (in thousands) Amortized Cost Gross Gross Fair Value Available for sale securities: Obligations of U.S. Government-sponsored enterprises $ 99,866 $ 271 $ (14 ) $ 100,123 Obligations of states and political subdivisions 32,684 887 (229 ) 33,342 Agency mortgage-backed securities 470,941 1,760 (3,045 ) 469,656 Total securities available for sale $ 603,491 $ 2,918 $ (3,288 ) $ 603,121 Held to maturity securities: Obligations of states and political subdivisions $ 14,704 $ 159 $ (15 ) $ 14,848 Agency mortgage-backed securities 61,464 93 (145 ) 61,412 Total securities held to maturity $ 76,168 $ 252 $ (160 ) $ 76,260 December 31, 2016 (in thousands) Amortized Cost Gross Gross Fair Value Available for sale securities: Obligations of U.S. Government-sponsored enterprises $ 107,312 $ 348 $ — $ 107,660 Obligations of states and political subdivisions 36,486 630 (485 ) 36,631 Agency mortgage-backed securities 319,345 1,101 (3,940 ) 316,506 Total securities available for sale $ 463,143 $ 2,079 $ (4,425 ) $ 460,797 Held to maturity securities: Obligations of states and political subdivisions $ 14,759 $ 11 $ (242 ) $ 14,528 Agency mortgage-backed securities 65,704 45 (638 ) 65,111 Total securities held to maturity $ 80,463 $ 56 $ (880 ) $ 79,639
Investments Classified by Contractual Maturity Date	The amortized cost and estimated fair value of debt securities at September 30, 2017 , by contractual maturity, are shown below. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. The weighted average life of the mortgage-backed securities is approximately 4 years. Available for sale Held to maturity (in thousands) Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Due in one year or less $ 2,940 $ 2,960 $ — $ — Due after one year through five years 110,538 111,122 184 194 Due after five years through ten years 15,710 16,241 12,996 13,126 Due after ten years 3,362 3,142 1,524 1,528 Agency mortgage-backed securities 470,941 469,656 61,464 61,412 $ 603,491 $ 603,121 $ 76,168 $ 76,260
Schedule of Unrealized Loss on Investments	The following table represents a summary of investment securities that had an unrealized loss: September 30, 2017 Less than 12 months 12 months or more Total (in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Obligations of U.S. Government-sponsored enterprises $ 10,127 $ 14 $ — $ — $ 10,127 $ 14 Obligations of states and political subdivisions 4,907 244 — — 4,907 244 Agency mortgage-backed securities 332,037 2,721 11,307 469 343,344 3,190 $ 347,071 $ 2,979 $ 11,307 $ 469 $ 358,378 $ 3,448 December 31, 2016 Less than 12 months 12 months or more Total (in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Obligations of states and political subdivisions $ 21,361 $ 408 $ 3,553 $ 320 $ 24,914 $ 728 Agency mortgage-backed securities 267,734 4,084 12,883 493 280,617 4,577 $ 289,095 $ 4,492 $ 16,436 $ 813 $ 305,531 $ 5,305

Loans (Tables)

Loans (Tables) - Portfolio loans, net	9 Months Ended
	Sep. 30, 2017
Non-covered Loans [Line Items]
Summary of Portfolio Loans by Category	The table below shows the loan portfolio composition including carrying value by segment of loans accounted for under ASC 310-30 (PCI loans) and loans not accounted for under this guidance, which includes our originated loans. (in thousands) September 30, 2017 December 31, 2016 Loans not accounted for as ASC 310-30 $ 3,948,676 $ 3,118,392 Loans accounted for as ASC 310-30 81,982 39,769 Total loans $ 4,030,658 $ 3,158,161 The following tables refer to loans not accounted for as ASC 310-30 loans. Below is a summary of loans by category at September 30, 2017 and December 31, 2016 : (in thousands) September 30, 2017 December 31, 2016 Commercial and industrial $ 1,861,285 $ 1,632,714 Real estate: Commercial - investor owned 737,986 544,808 Commercial - owner occupied 553,512 350,148 Construction and land development 302,182 194,542 Residential 339,377 240,760 Total real estate loans 1,933,057 1,330,258 Consumer and other 155,514 156,182 Loans, before unearned loan fees 3,949,856 3,119,154 Unearned loan fees, net (1,180 ) (762 ) Loans, including unearned loan fees $ 3,948,676 $ 3,118,392
Summary of Allowance for Loan Losses and the Recorded Investment in Portfolio Loans by Class and Category Based on Impairment Method	A summary of the activity in the allowance for loan losses and the recorded investment in loans by class and category based on impairment methodology through September 30, 2017 , and at December 31, 2016 , is as follows: (in thousands) Commercial and industrial CRE - investor owned CRE - owner occupied Construction and land development Residential real estate Consumer and other Total Allowance for loan losses: Balance at December 31, 2016 $ 26,996 $ 3,420 $ 2,890 $ 1,304 $ 2,023 $ 932 $ 37,565 Provision (provision reversal) for loan losses 1,835 (105 ) (249 ) (11 ) (3 ) 66 1,533 Losses charged off (133 ) — — — (9 ) (29 ) (171 ) Recoveries 80 9 89 9 25 9 221 Balance at March 31, 2017 $ 28,778 $ 3,324 $ 2,730 $ 1,302 $ 2,036 $ 978 $ 39,148 Provision (provision reversal) for loan losses 2,955 (39 ) 354 (51 ) 451 (47 ) 3,623 Losses charged off (6,035 ) — (45 ) (5 ) (265 ) (39 ) (6,389 ) Recoveries 57 102 1 49 62 20 291 Balance at June 30, 2017 $ 25,755 $ 3,387 $ 3,040 $ 1,295 $ 2,284 $ 912 $ 36,673 Provision (provision reversal) for loan losses 1,126 376 245 305 299 71 2,422 Losses charged off (613 ) — (45 ) — (503 ) (75 ) (1,236 ) Recoveries 205 12 6 25 172 13 433 Balance at September 30, 2017 $ 26,473 $ 3,775 $ 3,246 $ 1,625 $ 2,252 $ 921 $ 38,292 (in thousands) Commercial and industrial CRE - investor owned CRE - owner occupied Construction and land development Residential real estate Consumer and other Total Balance September 30, 2017 Allowance for loan losses - Ending balance: Individually evaluated for impairment $ 2,063 $ 120 $ — $ 186 $ 48 $ — $ 2,417 Collectively evaluated for impairment 24,410 3,655 3,246 1,439 2,204 921 35,875 Total $ 26,473 $ 3,775 $ 3,246 $ 1,625 $ 2,252 $ 921 $ 38,292 Loans - Ending balance: Individually evaluated for impairment $ 7,646 $ 544 $ 1,513 $ 323 $ 667 $ — $ 10,693 Collectively evaluated for impairment 1,853,639 737,442 551,999 301,859 338,710 154,334 3,937,983 Total $ 1,861,285 $ 737,986 $ 553,512 $ 302,182 $ 339,377 $ 154,334 $ 3,948,676 Balance December 31, 2016 Allowance for loan losses - Ending balance: Individually evaluated for impairment $ 2,909 $ — $ — $ 155 $ — $ — $ 3,064 Collectively evaluated for impairment 24,087 3,420 2,890 1,149 2,023 932 34,501 Total $ 26,996 $ 3,420 $ 2,890 $ 1,304 $ 2,023 $ 932 $ 37,565 Loans - Ending balance: Individually evaluated for impairment $ 12,523 $ 430 $ 1,854 $ 1,903 $ 62 $ — $ 16,772 Collectively evaluated for impairment 1,620,191 544,378 348,294 192,639 240,698 155,420 3,101,620 Total $ 1,632,714 $ 544,808 $ 350,148 $ 194,542 $ 240,760 $ 155,420 $ 3,118,392
Summary of Portfolio Loans Individually Evaluated for Impairment and Recorded Investment in Impaired Non-Covered Loans by Category	A summary of nonperforming loans individually evaluated for impairment by category at September 30, 2017 and December 31, 2016 , and the income recognized on impaired loans is as follows: September 30, 2017 (in thousands) Unpaid Recorded Recorded Allowance Total Related Allowance Average Commercial and industrial $ 13,981 $ 6,407 $ 1,044 $ 7,451 $ 2,020 $ 11,735 Real estate: Commercial - investor owned 562 259 285 544 120 542 Commercial - owner occupied — — — — — — Construction and land development 444 322 — 322 186 337 Residential 673 668 — 668 48 676 Consumer and other — — — — — — Total $ 15,660 $ 7,656 $ 1,329 $ 8,985 $ 2,374 $ 13,290 December 31, 2016 (in thousands) Unpaid Recorded Recorded Allowance Total Related Allowance Average Commercial and industrial $ 12,341 $ 566 $ 11,791 $ 12,357 $ 2,909 $ 4,489 Real estate: Commercial - investor owned 525 435 — 435 — 668 Commercial - owner occupied 225 231 — 231 — 227 Construction and land development 1,904 1,947 359 2,306 155 1,918 Residential 62 62 — 62 — 64 Consumer and other — — — — — — Total $ 15,057 $ 3,241 $ 12,150 $ 15,391 $ 3,064 $ 7,366 Three months ended September 30, Nine months ended September 30, (in thousands) 2017 2016 2017 2016 Total interest income that would have been recognized under original terms $ 306 $ 226 $ 961 $ 703 Total cash received and recognized as interest income on non-accrual loans 117 203 156 253 Total interest income recognized on accruing, impaired loans 8 32 55 63 There were no loans over 90 days past due and still accruing interest at September 30, 2017 or December 31, 2016 . The recorded investment in nonperforming loans by category at September 30, 2017 and December 31, 2016 , is as follows: September 30, 2017 (in thousands) Non-accrual Restructured, not on non-accrual Total Commercial and industrial $ 6,730 $ 721 $ 7,451 Real estate: Commercial - investor owned 544 — 544 Commercial - owner occupied — — — Construction and land development 322 — 322 Residential 668 — 668 Consumer and other — — — Total $ 8,264 $ 721 $ 8,985 December 31, 2016 (in thousands) Non-accrual Restructured, not on non-accrual Total Commercial and industrial $ 10,046 $ 2,311 $ 12,357 Real estate: Commercial - investor owned 435 — 435 Commercial - owner occupied 231 — 231 Construction and land development 2,286 20 2,306 Residential 62 — 62 Consumer and other — — — Total $ 13,060 $ 2,331 $ 15,391
Summary of Recorded Investment by Category for Portfolio Loans Restructured	The recorded investment by category for the portfolio loans that have been restructured during the nine months ended September 30, 2017 and 2016 , is as follows: Nine months ended September 30, 2017 Nine months ended September 30, 2016 (in thousands, except for number of loans) Number of loans Pre-Modification Outstanding Recorded Balance Post-Modification Outstanding Recorded Balance Number of loans Pre-Modification Outstanding Recorded Balance Post-Modification Outstanding Recorded Balance Commercial and industrial 1 $ 676 $ 676 2 $ 2,341 $ 2,341 Real estate: Commercial - investor owned — — — 1 248 248 Commercial - owner occupied — — — — — — Construction and land development — — — 1 20 20 Residential — — — — — — Consumer and other — — — — — — Total 1 $ 676 $ 676 4 $ 2,609 $ 2,609
Summary of Recorded Investment by Category for Portfolio Loans Restructured and Subsequently Defaulted	As of September 30, 2017 , the Company had $2.2 million in specific reserves allocated to $9.5 million of loans that have been restructured. During the three and nine months ended September 30, 2016 , there were no portfolio loans that subsequently defaulted. There were no portfolio loans restructured that subsequently defaulted during the three months ended September 30, 2017 . Portfolio loans restructured that subsequently defaulted during the nine months ended September 30, 2017 , are as follows: Nine months ended September 30, 2017 (in thousands, except for number of loans) Number of loans Recorded Balance Commercial and industrial 2 $ 343 Real estate: Commercial - investor owned — — Commercial - owner occupied — — Construction and land development — — Residential 1 5 Consumer and other — — Total 3 $ 348
Summary of Aging of Recorded Investment in Past Due Portfolio Loans by Portfolio Class and Category	The aging of the recorded investment in past due loans by portfolio class and category at September 30, 2017 and December 31, 2016 is shown below. September 30, 2017 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ 9,147 $ 283 $ 9,430 $ 1,851,855 $ 1,861,285 Real estate: Commercial - investor owned 986 — 986 737,000 737,986 Commercial - owner occupied 266 — 266 553,246 553,512 Construction and land development — 323 323 301,859 302,182 Residential 485 668 1,153 338,224 339,377 Consumer and other 1,542 — 1,542 152,792 154,334 Total $ 12,426 $ 1,274 $ 13,700 $ 3,934,976 $ 3,948,676 December 31, 2016 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ 334 $ 171 $ 505 $ 1,632,209 $ 1,632,714 Real estate: Commercial - investor owned — 175 175 544,633 544,808 Commercial - owner occupied 212 225 437 349,711 350,148 Construction and land development 355 1,528 1,883 192,659 194,542 Residential 91 — 91 240,669 240,760 Consumer and other 7 — 7 155,413 155,420 Total $ 999 $ 2,099 $ 3,098 $ 3,115,294 $ 3,118,392
Summary of Recorded Investment by Risk Category of Portfolio Loans by Portfolio Class and Category	The recorded investment by risk category of the loans by portfolio class and category at September 30, 2017 , which is based upon the most recent analysis performed, and December 31, 2016 is as follows: September 30, 2017 (in thousands) Pass (1-6) Watch (7) Substandard (8) Doubtful (9) Total Commercial and industrial $ 1,708,153 $ 90,885 $ 62,247 $ — $ 1,861,285 Real estate: Commercial - investor owned 720,912 12,592 4,482 — 737,986 Commercial - owner occupied 513,939 33,249 6,324 — 553,512 Construction and land development 298,613 2,558 1,011 — 302,182 Residential 328,434 3,989 6,954 — 339,377 Consumer and other 153,113 375 846 — 154,334 Total $ 3,723,164 $ 143,648 $ 81,864 $ — $ 3,948,676 December 31, 2016 (in thousands) Pass (1-6) Watch (7) Substandard (8) Doubtful (9) Total Commercial and industrial $ 1,499,114 $ 57,416 $ 76,184 $ — $ 1,632,714 Real estate: Commercial - investor owned 530,494 10,449 3,865 — 544,808 Commercial - owner occupied 306,658 39,249 4,241 — 350,148 Construction and land development 185,505 6,575 2,462 — 194,542 Residential 233,479 2,997 4,284 — 240,760 Consumer and other 153,984 — 1,436 — 155,420 Total $ 2,909,234 $ 116,686 $ 92,472 $ — $ 3,118,392

Purchased Credit Impaired ("P25

Purchased Credit Impaired ("PCI") Loans (Tables)	9 Months Ended
	Sep. 30, 2017
Covered Loans [Line Items]
Rollforward of PCI Loans, Net of Allowance for Loan Losses	The following table is a rollforward of PCI loans, net of the allowance for loan losses, for the nine months ended September 30, 2017 and 2016 . (in thousands) Contractual Cashflows Non-accretable Difference Accretable Yield Carrying Amount Balance December 31, 2016 $ 66,003 $ 18,902 $ 13,176 $ 33,925 Acquisitions 68,763 14,296 5,312 49,155 Principal reductions and interest payments (16,319 ) — — (16,319 ) Accretion of loan discount — — (5,473 ) 5,473 Changes in contractual and expected cash flows due to remeasurement 11,110 (702 ) 3,776 8,036 Reductions due to disposals (6,393 ) (1,612 ) (1,595 ) (3,186 ) Balance September 30, 2017 $ 123,164 $ 30,884 $ 15,196 $ 77,084 Balance December 31, 2015 $ 116,689 $ 26,765 $ 25,341 $ 64,583 Principal reductions and interest payments (20,417 ) — — (20,417 ) Accretion of loan discount — — (4,984 ) 4,984 Changes in contractual and expected cash flows due to remeasurement 9,194 975 (1,043 ) 9,262 Reductions due to disposals (27,888 ) (6,779 ) (3,713 ) (17,396 ) Balance September 30, 2016 $ 77,578 $ 20,961 $ 15,601 $ 41,016
Covered Loans
Covered Loans [Line Items]
Summary of PCI Loans by Category	Below is a summary of PCI loans by category at September 30, 2017 and December 31, 2016 : September 30, 2017 December 31, 2016 (in thousands) Weighted- Average Risk Rating 1 Recorded Investment PCI Loans Weighted- Average Risk Rating 1 Recorded Investment PCI Loans Commercial and industrial 6.26 $ 3,676 5.87 $ 3,523 Real estate: Commercial - investor owned 7.29 45,865 6.95 8,162 Commercial - owner occupied 6.50 11,786 6.39 11,863 Construction and land development 5.93 7,927 5.80 4,365 Residential 6.05 12,661 5.64 11,792 Total real estate loans 78,239 36,182 Consumer and other 2.99 67 1.64 64 Purchased credit impaired loans $ 81,982 $ 39,769 1 Risk ratings are based on the borrower's contractual obligation, which is not reflective of the purchase discount.
Summary of Aging of Recorded Investment in Past Due PCI Loans by Portfolio Class and Category	The aging of the recorded investment in past due PCI loans by portfolio class and category at September 30, 2017 and December 31, 2016 is shown below: September 30, 2017 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ — $ — $ — $ 3,676 $ 3,676 Real estate: Commercial - investor owned 429 396 825 45,040 45,865 Commercial - owner occupied 46 909 955 10,831 11,786 Construction and land development — 478 478 7,449 7,927 Residential 748 992 1,740 10,921 12,661 Consumer and other — — — 67 67 Total $ 1,223 $ 2,775 $ 3,998 $ 77,984 $ 81,982 December 31, 2016 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ — $ — $ — $ 3,523 $ 3,523 Real estate: Commercial - investor owned — — — 8,162 8,162 Commercial - owner occupied — — — 11,863 11,863 Construction and land development — — — 4,365 4,365 Residential 169 51 220 11,572 11,792 Consumer and other — — — 64 64 Total $ 169 $ 51 $ 220 $ 39,549 $ 39,769
Summary of FDIC Loss Share Receivable	Outstanding customer balances on PCI loans were $107.8 million and $54.6 million as of September 30, 2017 , and December 31, 2016 , respectively.

Commitments (Tables)

Commitments (Tables)	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Commitments	The contractual amounts of off-balance-sheet financial instruments as of September 30, 2017 , and December 31, 2016 , are as follows: (in thousands) September 30, 2017 December 31, 2016 Commitments to extend credit $ 1,263,809 $ 1,075,170 Letters of credit 74,007 78,954

Derivative Financial Instrume27

Derivative Financial Instruments (Tables) - Client-Related	9 Months Ended
	Sep. 30, 2017
Derivative [Line Items]
Schedule of Notional Amounts and Fair Values of Derivative Instruments and Client-Related Derivative Instruments	The table below summarizes the notional amounts and fair values of the client-related derivative instruments: Asset Derivatives (Other Assets) Liability Derivatives (Other Liabilities) Notional Amount Fair Value Fair Value (in thousands) September 30, December 31, September 30, December 31, September 30, December 31, Non-designated hedging instruments Interest rate swap contracts $ 270,542 $ 124,322 $ 1,902 $ 982 $ 1,902 $ 982 Foreign exchange forward contracts 1,376 3,034 1,376 3,034 1,376 3,034
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	For the three and nine months ended September 30, 2017 and 2016 , the gains and losses offset each other due to the Company's hedging of the client swaps and foreign exchange contracts with other bank counterparties.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Summary of Financial Instruments Measured at Fair Value on a Recurring Basis	The following table summarizes financial instruments measured at fair value on a recurring basis as of September 30, 2017 and December 31, 2016 , segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: September 30, 2017 (in thousands) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Fair Value Assets Securities available for sale Obligations of U.S. Government-sponsored enterprises $ — $ 100,123 $ — $ 100,123 Obligations of states and political subdivisions — 33,341 — 33,341 Residential mortgage-backed securities — 469,657 — 469,657 Total securities available for sale $ — $ 603,121 $ — $ 603,121 State tax credits held for sale — — 1,274 1,274 Derivative financial instruments — 3,278 — 3,278 Total assets $ — $ 606,399 $ 1,274 $ 607,673 Liabilities Derivative financial instruments $ — $ 3,278 $ — $ 3,278 Total liabilities $ — $ 3,278 $ — $ 3,278 December 31, 2016 (in thousands) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Fair Value Assets Securities available for sale Obligations of U.S. Government-sponsored enterprises $ — $ 107,660 $ — $ 107,660 Obligations of states and political subdivisions — 33,542 3,089 36,631 Residential mortgage-backed securities — 316,506 — 316,506 Total securities available for sale $ — $ 457,708 $ 3,089 $ 460,797 State tax credits held for sale — — 3,585 3,585 Derivative financial instruments — 4,016 — 4,016 Total assets $ — $ 461,724 $ 6,674 $ 468,398 Liabilities Derivative financial instruments $ — $ 4,016 $ — $ 4,016 Total liabilities $ — $ 4,016 $ — $ 4,016
Schedule of Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis	The following table presents the changes in Level 3 financial instruments measured at fair value on a recurring basis as of September 30, 2017 and 2016 . • Purchases, sales, issuances and settlements . There were no Level 3 purchases during the quarters ended September 30, 2017 or 2016 . • Transfers in and/or out of Level 3 . There were no Level 3 transfers during the quarters ended September 30, 2017 and 2016 . Securities available for sale, at fair value Three months ended September 30, Nine months ended September 30, (in thousands) 2017 2016 2017 2016 Beginning balance $ — $ 3,093 $ 3,089 $ 3,077 Total gains: Included in other comprehensive income — 1 4 17 Purchases, sales, issuances and settlements: Purchases — — — — Transfer in and/or out of Level 3 — — (3,093 ) — Ending balance $ — $ 3,094 $ — $ 3,094 Change in unrealized gains relating to assets still held at the reporting date $ — $ 1 $ — $ 17 State tax credits held for sale Three months ended September 30, Nine months ended September 30, (in thousands) 2017 2016 2017 2016 Beginning balance $ 1,274 $ 4,774 $ 3,585 $ 5,941 Total gains: Included in earnings — 27 49 144 Purchases, sales, issuances and settlements: Sales — — (2,360 ) (1,284 ) Ending balance $ 1,274 $ 4,801 $ 1,274 $ 4,801 Change in unrealized gains (losses) relating to assets still held at the reporting date $ — $ 27 $ (655 ) $ (237 )
Summary of Financial Instruments and Non-Financial Assets Measured at Fair Value on a Non-Recurring Basis	The following table presents financial instruments and non-financial assets measured at fair value on a non-recurring basis as of September 30, 2017 . (1) (1) (1) (1) (in thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant (Level 3) Total losses for the three Total losses for the nine Impaired loans $ 2,743 $ — $ — $ 2,743 $ 613 $ 5,876 Other real estate 26 — — 26 38 38 Total $ 2,769 $ — $ — $ 2,769 $ 651 $ 5,914 (1) The amounts represent only balances measured at fair value during the period and still held as of the reporting date.
Summary of Carrying Amount and Fair Values of Financial Instruments Reported on the Balance Sheets	Following is a summary of the carrying amounts and fair values of the Company’s financial instruments on the consolidated balance sheets at September 30, 2017 and December 31, 2016 . September 30, 2017 December 31, 2016 (in thousands) Carrying Amount Estimated fair value Carrying Amount Estimated fair value Balance sheet assets Cash and due from banks $ 76,777 $ 76,777 $ 54,288 $ 54,288 Federal funds sold 1,155 1,155 446 446 Interest-bearing deposits 107,821 107,821 145,048 145,048 Securities available for sale 603,121 603,121 460,797 460,797 Securities held to maturity 76,168 76,260 80,463 79,639 Other investments, at cost 29,436 29,436 14,840 14,840 Loans held for sale 6,411 6,411 9,562 9,562 Derivative financial instruments 3,278 3,278 4,016 4,016 Loans, net 3,987,467 4,009,071 3,114,752 3,125,701 State tax credits, held for sale 35,291 37,781 38,071 41,264 Accrued interest receivable 14,213 14,213 11,117 11,117 Balance sheet liabilities Deposits 4,059,211 4,057,561 3,233,361 3,232,414 Subordinated debentures and notes 118,093 100,062 105,540 86,052 Federal Home Loan Bank advances 248,868 249,168 — — Other borrowings 219,104 219,012 276,980 276,905 Derivative financial instruments 3,278 3,278 4,016 4,016 Accrued interest payable 2,007 2,007 1,105 1,105
Schedule of Estimated Fair Values of Financial Instruments Not Recorded at Fair Value on Balance Sheet	The following table presents the level in the fair value hierarchy for the estimated fair values of only the Company’s financial instruments that are not already presented on the condensed consolidated balance sheets at fair value at September 30, 2017 , and December 31, 2016 . Estimated Fair Value Measurement at Reporting Date Using Balance at (in thousands) Level 1 Level 2 Level 3 Financial Assets: Securities held to maturity $ — $ 76,260 $ — $ 76,260 Portfolio loans, net — — 4,009,071 4,009,071 State tax credits, held for sale — — 36,508 36,508 Financial Liabilities: Deposits 3,442,015 — 615,546 4,057,561 Subordinated debentures and notes — 100,062 — 100,062 Federal Home Loan Bank advances — 249,168 — 249,168 Other borrowings — 219,012 — 219,012 Estimated Fair Value Measurement at Reporting Date Using Balance at December 31, 2016 (in thousands) Level 1 Level 2 Level 3 Financial Assets: Securities held to maturity $ — $ 79,639 $ — $ 79,639 Portfolio loans, net — — 3,125,701 3,125,701 State tax credits, held for sale — — 37,679 37,679 Financial Liabilities: Deposits 2,760,202 — 472,212 3,232,414 Subordinated debentures and notes — 86,052 — 86,052 Other borrowings — 276,905 — 276,905

Summary of Significant Accoun29

Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2017	Sep. 30, 2017
Property, Plant and Equipment [Line Items]
Reclassification for the adoption of ASU 2016-09	$ 5.2
Decrease in Income Taxes		$ 1.8

Acquisitions & Divestitures - N

Acquisitions & Divestitures - Narrative (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)	Feb. 10, 2017USD ($)$ / shares
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of operating JCB branches			13
Total cash paid to JCB shareholders and holders of JCB stock options			$ 29,300,000
Cash consideration per share to JCB shareholders | $ / shares			$ 85.39
Business Acquisition, Goodwill, Expected Tax Deductible Amount			$ 87,000,000
Common stock offered per share			2.75
Total shares awarded to JCB shareholders			3,300,000
EFSC Closing Stock Price			$ 42.95
Transaction value including JCB's common stock and stock options			$ 171,000,000
Business Combination, Acquisition Related Costs	$ 6,500,000	$ 1,400,000
Fair Value Discount Recorded to Portfolio Loans	24,700,000
Fair Value Discount Recorded to Fixed Assets	1,100,000
Assets	$ 200,000

Acquisitions & Divestitures - S

Acquisitions & Divestitures - Summary of Balance Sheet Amounts Relative to Branches Sold (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)$ / shares	Sep. 30, 2016USD ($)$ / shares	Feb. 10, 2017USD ($)	Dec. 31, 2016USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income as reported	$ 16,315,000	$ 11,832,000	$ 40,661,000	$ 35,209,000
Cash and cash equivalents	183,108,000		183,108,000			$ 198,802,000
Property, Plant and Equipment, Net	32,803,000		32,803,000			14,910,000
Interest Receivable	14,213,000		14,213,000			11,117,000
Goodwill	117,345,000		117,345,000			30,334,000
Other Intangible Assets	11,745,000		11,745,000			2,151,000
Deposits	4,059,211,000		4,059,211,000			3,233,361,000
Other Borrowings	209,104,000		209,104,000			276,980,000
Interest Payable	2,007,000		2,007,000			1,105,000
Other Liabilities	$ 37,869,000		$ 37,869,000			$ 77,244,000
Total cash paid to JCB shareholders and holders of JCB stock options					$ 29,300,000
Common shares issued related to acquisition	141,729,000	0	141,729,000	0
Transaction value including JCB's common stock and stock options					171,000,000
Business Acquisition, Goodwill, Expected Tax Deductible Amount					87,000,000
Pro Forma [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues			$ 155,907,000	$ 146,623,000
Net income as reported			$ 40,151,000	$ 42,298,000
Diluted Earnings Per Share Pro Forma | $ / shares			$ 1.70	$ 1.80
As Recorded by JCB [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents					33,739,000
Interest-bearing Deposit Liabilities					1,715,000
Securities					148,670,000
Portfolio loans, net					685,905,000
Other real estate owned					6,762,000
Other Investments					2,695,000
Property, Plant and Equipment, Net					21,780,000
Interest Receivable					2,794,000
Goodwill					7,806,000
Other Intangible Assets					25,000
Deferred Tax Assets					4,634,000
Other Assets					19,107,000
Total assets acquired					935,632,000
Deposits					764,539,000
Other Borrowings					55,430,000
Trust preferred securities					12,887,000
Interest Payable					653,000
Other Liabilities					5,006,000
Total Liabilities Assumed					838,515,000
Net assets acquired					97,117,000
Adjustments associated with acquisition [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents					0
Interest-bearing Deposit Liabilities					0
Securities					0
Portfolio loans, net					(11,094,000)
Other real estate owned					(5,082,000)
Other Investments					0
Property, Plant and Equipment, Net					(3,325,000)
Interest Receivable					0
Goodwill					(7,806,000)
Other Intangible Assets					11,489,000
Deferred Tax Assets					3,991,000
Other Assets					(296,000)
Total assets acquired					(12,123,000)
Deposits					629,000
Other Borrowings					681,000
Trust preferred securities					(382,000)
Interest Payable					0
Other Liabilities					65,000
Total Liabilities Assumed					993,000
Net assets acquired					(13,116,000)
As Recorded by EFSC [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents					33,739,000
Interest-bearing Deposit Liabilities					1,715,000
Securities					148,670,000
Portfolio loans, net					674,811,000
Other real estate owned					1,680,000
Other Investments					2,695,000
Property, Plant and Equipment, Net					18,455,000
Interest Receivable					2,794,000
Goodwill					0
Other Intangible Assets					11,514,000
Deferred Tax Assets					8,625,000
Other Assets					18,811,000
Total assets acquired					923,509,000
Deposits					765,168,000
Other Borrowings					56,111,000
Trust preferred securities					12,505,000
Interest Payable					653,000
Other Liabilities					5,071,000
Total Liabilities Assumed					839,508,000
Net assets acquired					84,001,000
Total cash paid to JCB shareholders and holders of JCB stock options					$ 29,283,000
Common shares issued related to acquisition					141,729,000
Transaction value including JCB's common stock and stock options					$ 171,000,000
Business Acquisition, Goodwill, Expected Tax Deductible Amount					$ 87,011,000

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share
Net income as reported	$ 16,315	$ 11,832	$ 40,661	$ 35,209
Impact of assumed conversions
Weighted average common shares outstanding (in shares)	23,324,000	19,997,000	22,914,000	20,002,000
Additional dilutive common stock equivalents (in shares)	250,000	227,000	295,000	229,000
Weighted average diluted common shares outstanding (in shares)	23,574,000	20,224,000	23,209,000	20,231,000
Basic earnings per common share (in dollars per share)	$ 0.70	$ 0.59	$ 1.77	$ 1.76
Diluted earnings per common share (in dollars per share)	$ 0.69	$ 0.59	$ 1.75	$ 1.74
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Common stock equivalents excluded from earnings per share calculations due to anti-dilutive effect (in shares)			0	0
Convertible Debt Securities
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Convertible trust preferred securities, interest rate, stated percentage	9.00%	9.00%	9.00%	9.00%

Investments - Schedule of Avail

Investments - Schedule of Available-for-sale and Held-to-Maturity Securities Reconciliation (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 76,168	$ 80,463
Gross Unrealized Gains	252	56
Gross Unrealized Losses	(160)	(880)
Fair Value	76,260	79,639
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	603,491	463,143
Gross Unrealized Gains	2,918	2,079
Gross Unrealized Losses	(3,288)	(4,425)
Fair Value	603,121	460,797
Obligations of U.S. Government-sponsored enterprises
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	99,866	107,312
Gross Unrealized Gains	271	348
Gross Unrealized Losses	(14)	0
Fair Value	100,123	107,660
Obligations of states and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	32,684	36,486
Gross Unrealized Gains	887	630
Gross Unrealized Losses	(229)	(485)
Fair Value	33,342	36,631
Agency mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	470,941	319,345
Gross Unrealized Gains	1,760	1,101
Gross Unrealized Losses	(3,045)	(3,940)
Fair Value	469,656	316,506
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	14,704	14,759
Gross Unrealized Gains	159	11
Gross Unrealized Losses	(15)	(242)
Fair Value	14,848	14,528
Agency mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	61,464	65,704
Gross Unrealized Gains	93	45
Gross Unrealized Losses	(145)	(638)
Fair Value	$ 61,412	$ 65,111

Investments - Investments Class

Investments - Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Available for sale, Amortized Cost
Due in one year or less	$ 2,940
Due after one year through five years	110,538
Due after five years through ten years	15,710
Due after ten years	3,362
Agency mortgage-backed securities	470,941
Amortized Cost	603,491	$ 463,143
Available for sale, Estimated Fair Value
Due in one year or less	2,960
Due after one year through five years	111,122
Due after five years through ten years	16,241
Due after ten years	3,142
Agency mortgage-backed securities	469,656
Available for sale, fair value	603,121	460,797
Held to maturity, Amortized Cost
Due in one year or less	0
Due after one year through five years	184
Due after five years through ten years	12,996
Due after ten years	1,524
Agency mortgage-backed securities	61,464
Amortized Cost	76,168	80,463
Held to maturity, Estimated Fair Value
Due in one year or less	0
Due after one year through five years	194
Due after five years through ten years	13,126
Due after ten years	1,528
Agency mortgage-backed securities	61,412
Held to maturity, fair value	$ 76,260	$ 79,639

Investments - Schedule of Unrea

Investments - Schedule of Unrealized Loss on Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 347,071	$ 289,095
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2,979	4,492
12 months or more, fair value	11,307	16,436
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	469	813
Total, fair value	358,378	305,531
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	3,448	5,305
Obligations of U.S. Government-sponsored enterprises
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	10,127
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	14
12 months or more, fair value	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Total, fair value	10,127
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	14
Obligations of states and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	4,907	21,361
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	244	408
12 months or more, fair value	0	3,553
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	320
Total, fair value	4,907	24,914
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	244	728
Agency mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	332,037	267,734
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2,721	4,084
12 months or more, fair value	11,307	12,883
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	469	493
Total, fair value	343,344	280,617
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 3,190	$ 4,577

Investments - Narrative (Detail

Investments - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Other investments, at cost	$ 29,436	$ 14,840
Maximum percentage of shareholders' equity security holdings held of one issuer	10.00%	10.00%
Available-for-sale securities pledged as collateral, fair value	$ 449,800	$ 407,300
Mortgage-backed securities, weighted average life	4 years

Loans - Summary of Portfolio Lo

Loans - Summary of Portfolio Loans by Category (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, including unearned loan fees	$ 4,030,658	$ 3,158,161
Portfolio loans, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	3,949,856	3,119,154
Unearned loan fees, net	(1,180)	(762)
Loans, including unearned loan fees	3,948,676	3,118,392
Portfolio loans, net | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	1,861,285	1,632,714
Portfolio loans, net | Commercial - investor owned
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	737,986	544,808
Portfolio loans, net | Commercial - owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	553,512	350,148
Portfolio loans, net | Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	302,182	194,542
Portfolio loans, net | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	339,377	240,760
Portfolio loans, net | Total real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	1,933,057	1,330,258
Portfolio loans, net | Consumer and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, before unearned loan fees	155,514	156,182
Loans, including unearned loan fees	154,334	155,420
Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	81,982	39,769
Loans, before unearned loan fees	81,982	39,769
Covered Loans [Member] | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	3,676	3,523
Loans, before unearned loan fees	3,676	3,523
Covered Loans [Member] | Commercial - investor owned
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	45,865	8,162
Loans, before unearned loan fees	45,865	8,162
Covered Loans [Member] | Commercial - owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	11,786	11,863
Loans, before unearned loan fees	11,786	11,863
Covered Loans [Member] | Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	7,927	4,365
Loans, before unearned loan fees	7,927	4,365
Covered Loans [Member] | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	12,661	11,792
Loans, before unearned loan fees	12,661	11,792
Covered Loans [Member] | Total real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	78,239	36,182
Covered Loans [Member] | Consumer and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	67	64
Loans, before unearned loan fees	$ 67	$ 64

Loans - Summary of Allowance fo

Loans - Summary of Allowance for Loan Losses by Portfolio Class and Category (Details) - Portfolio loans, net - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2016	$ 39,148	$ 37,565
Provision (provision reversal) for loan losses	3,623	1,533	$ 2,422
Losses charged off	(6,389)	(171)	(1,236)
Recoveries	291	221	433
Balance at March 31, 2017	36,673	39,148	38,292
Commercial and industrial
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2016	28,778	26,996
Provision (provision reversal) for loan losses	2,955	1,835	1,126
Losses charged off	(6,035)	(133)	(613)
Recoveries	57	80	205
Balance at March 31, 2017	25,755	28,778	26,473
CRE - owner occupied
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2016	2,730	2,890
Provision (provision reversal) for loan losses	(354)	(249)	245
Losses charged off	(45)	0	(45)
Recoveries	1	89	6
Balance at March 31, 2017	3,040	2,730	3,246
Commercial Real Estate Investor Owned
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2016	3,324	3,420
Provision (provision reversal) for loan losses	39	(105)	376
Losses charged off	0	0	0
Recoveries	102	9	12
Balance at March 31, 2017	3,387	3,324	3,775
Construction and land development
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2016	1,302	1,304
Provision (provision reversal) for loan losses	51	(11)	305
Losses charged off	(5)	0	0
Recoveries	49	9	25
Balance at March 31, 2017	1,295	1,302	1,625
Residential real estate
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2016	2,036	2,023
Provision (provision reversal) for loan losses	451	(3)	299
Losses charged off	(265)	(9)	(503)
Recoveries	62	25	172
Balance at March 31, 2017	2,284	2,036	2,252
Consumer and other
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2016	978	932
Provision (provision reversal) for loan losses	(47)	66	71
Losses charged off	(39)	(29)	(75)
Recoveries	20	9	13
Balance at March 31, 2017	$ 912	$ 978	$ 921

Loans - Summary of Recorded Inv

Loans - Summary of Recorded Investment in Portfolio Loans by Class and Category Based on Impairment Method (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)loan	Sep. 30, 2016USD ($)loan	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Loans - Ending balance:
Loans and Leases Receivable, Gross	$ 4,030,658				$ 3,158,161
Portfolio loans, net
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Financing Receivable, Modifications, Number of Contracts | loan	1	4
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 676	$ 2,609
Financing Receivable, Modifications, Pre-Modification Recorded Investment	676	2,609
Individually evaluated for impairment	2,417				3,064
Collectively evaluated for impairment	35,875				34,501
Total	38,292	$ 38,292	$ 36,673	$ 39,148	37,565
Loans - Ending balance:
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums	(1,180)				(762)
Individually evaluated for impairment	10,693				16,772
Collectively evaluated for impairment	3,937,983				3,101,620
Total	3,949,856				3,119,154
Loans and Leases Receivable, Gross	$ 3,948,676				3,118,392
Portfolio loans, net | Commercial and industrial
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Financing Receivable, Modifications, Number of Contracts | loan	1	2
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 676	$ 2,341
Financing Receivable, Modifications, Pre-Modification Recorded Investment	676	2,341
Individually evaluated for impairment	2,063				2,909
Collectively evaluated for impairment	24,410				24,087
Total	26,473	$ 26,473	25,755	28,778	26,996
Loans - Ending balance:
Individually evaluated for impairment	7,646				12,523
Collectively evaluated for impairment	1,853,639				1,620,191
Total	$ 1,861,285				1,632,714
Portfolio loans, net | Commercial Real Estate Investor Owned
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Financing Receivable, Modifications, Number of Contracts | loan	0	1
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 248
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0	248
Individually evaluated for impairment	120				0
Collectively evaluated for impairment	3,655				3,420
Total	3,775	$ 3,775	3,387	3,324	3,420
Loans - Ending balance:
Individually evaluated for impairment	544				430
Collectively evaluated for impairment	737,442				544,378
Total	$ 737,986				544,808
Portfolio loans, net | CRE - owner occupied
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Financing Receivable, Modifications, Number of Contracts | loan	0	0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 0
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0	0
Individually evaluated for impairment	0				0
Collectively evaluated for impairment	3,246				2,890
Total	3,246	$ 3,246	3,040	2,730	2,890
Loans - Ending balance:
Individually evaluated for impairment	1,513				1,854
Collectively evaluated for impairment	551,999				348,294
Total	$ 553,512				350,148
Portfolio loans, net | Construction and land development
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Financing Receivable, Modifications, Number of Contracts | loan	0	1
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 20
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0	20
Individually evaluated for impairment	186				155
Collectively evaluated for impairment	1,439				1,149
Total	1,625	1,625	1,295	1,302	1,304
Loans - Ending balance:
Individually evaluated for impairment	323				1,903
Collectively evaluated for impairment	301,859				192,639
Total	302,182				194,542
Portfolio loans, net | Residential real estate
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Individually evaluated for impairment	48				0
Collectively evaluated for impairment	2,204				2,023
Total	2,252	$ 2,252	2,284	2,036	2,023
Loans - Ending balance:
Individually evaluated for impairment	667				62
Collectively evaluated for impairment	338,710				240,698
Total	$ 339,377				240,760
Portfolio loans, net | Consumer and other
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Financing Receivable, Modifications, Number of Contracts | loan	0	0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 0
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0	0
Individually evaluated for impairment	0				0
Collectively evaluated for impairment	921				932
Total	921	$ 921	$ 912	$ 978	932
Loans - Ending balance:
Individually evaluated for impairment	0				0
Collectively evaluated for impairment	154,334				155,420
Total	155,514				156,182
Loans and Leases Receivable, Gross	$ 154,334				$ 155,420
Portfolio loans, net | Residential Portfolio Segment [Member]
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Financing Receivable, Modifications, Number of Contracts | loan	0	0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 0
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 0	$ 0

Loans - Summary of Portfolio 40

Loans - Summary of Portfolio Loans Individually Evaluated for Impairment by Category (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended	12 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Related Allowance				$ 1,200
Portfolio loans, net
Financing Receivable, Impaired [Line Items]
Provision for Loan, Lease, and Other Losses	$ 3,623	$ 1,533	$ 2,422
Unpaid Contractual Principal Balance				15,660	$ 15,057
Recorded Investment With No Allowance				7,656	3,241
Recorded Investment With Allowance				1,329	12,150
Total Recorded Investment				8,985	15,391
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment				2,417	3,064
Impaired Financing Receivable, Related Allowance				2,374	3,064
Average Recorded Investment				13,290	7,366
Financing Receivable, Allowance for Credit Losses, Write-downs	(6,389)	(171)	(1,236)
Financing Receivable, Allowance for Credit Losses, Recovery	291	221	433
Financing Receivable, Allowance for Credit Losses	36,673	39,148	38,292	38,292	37,565
Portfolio loans, net | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Provision for Loan, Lease, and Other Losses	2,955	1,835	1,126
Unpaid Contractual Principal Balance				13,981	12,341
Recorded Investment With No Allowance				6,407	566
Recorded Investment With Allowance				1,044	11,791
Total Recorded Investment				7,451	12,357
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment				2,063	2,909
Impaired Financing Receivable, Related Allowance				2,020	2,909
Average Recorded Investment				11,735	4,489
Financing Receivable, Allowance for Credit Losses, Write-downs	(6,035)	(133)	(613)
Financing Receivable, Allowance for Credit Losses, Recovery	57	80	205
Financing Receivable, Allowance for Credit Losses	25,755	28,778	26,473	26,473	26,996
Portfolio loans, net | Commercial - owner occupied
Financing Receivable, Impaired [Line Items]
Provision for Loan, Lease, and Other Losses	(354)	(249)	245
Unpaid Contractual Principal Balance				0	225
Recorded Investment With No Allowance				0	231
Recorded Investment With Allowance				0	0
Total Recorded Investment				0	231
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment				0	0
Impaired Financing Receivable, Related Allowance				0	0
Average Recorded Investment				0	227
Financing Receivable, Allowance for Credit Losses, Write-downs	(45)	0	(45)
Financing Receivable, Allowance for Credit Losses, Recovery	1	89	6
Financing Receivable, Allowance for Credit Losses	3,040	2,730	3,246	3,246	2,890
Portfolio loans, net | Commercial - investor owned
Financing Receivable, Impaired [Line Items]
Provision for Loan, Lease, and Other Losses	39	(105)	376
Unpaid Contractual Principal Balance				562	525
Recorded Investment With No Allowance				259	435
Recorded Investment With Allowance				285	0
Total Recorded Investment				544	435
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment				120	0
Impaired Financing Receivable, Related Allowance				120	0
Average Recorded Investment				542	668
Financing Receivable, Allowance for Credit Losses, Write-downs	0	0	0
Financing Receivable, Allowance for Credit Losses, Recovery	102	9	12
Financing Receivable, Allowance for Credit Losses	3,387	3,324	3,775	3,775	3,420
Portfolio loans, net | Construction and land development
Financing Receivable, Impaired [Line Items]
Provision for Loan, Lease, and Other Losses	51	(11)	305
Unpaid Contractual Principal Balance				444	1,904
Recorded Investment With No Allowance				322	1,947
Recorded Investment With Allowance				0	359
Total Recorded Investment				322	2,306
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment				186	155
Impaired Financing Receivable, Related Allowance				186	155
Average Recorded Investment				337	1,918
Financing Receivable, Allowance for Credit Losses, Write-downs	(5)	0	0
Financing Receivable, Allowance for Credit Losses, Recovery	49	9	25
Financing Receivable, Allowance for Credit Losses	1,295	1,302	1,625	1,625	1,304
Portfolio loans, net | Residential real estate
Financing Receivable, Impaired [Line Items]
Provision for Loan, Lease, and Other Losses	451	(3)	299
Unpaid Contractual Principal Balance				673	62
Recorded Investment With No Allowance				668	62
Recorded Investment With Allowance				0	0
Total Recorded Investment				668	62
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment				48	0
Impaired Financing Receivable, Related Allowance				48	0
Average Recorded Investment				676	64
Financing Receivable, Allowance for Credit Losses, Write-downs	(265)	(9)	(503)
Financing Receivable, Allowance for Credit Losses, Recovery	62	25	172
Financing Receivable, Allowance for Credit Losses	2,284	2,036	2,252	2,252	2,023
Portfolio loans, net | Consumer and other
Financing Receivable, Impaired [Line Items]
Provision for Loan, Lease, and Other Losses	(47)	66	71
Unpaid Contractual Principal Balance				0	0
Recorded Investment With No Allowance				0	0
Recorded Investment With Allowance				0	0
Total Recorded Investment				0	0
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment				0	0
Impaired Financing Receivable, Related Allowance				0	0
Average Recorded Investment				0	0
Financing Receivable, Allowance for Credit Losses, Write-downs	(39)	(29)	(75)
Financing Receivable, Allowance for Credit Losses, Recovery	20	9	13
Financing Receivable, Allowance for Credit Losses	$ 912	$ 978	$ 921	$ 921	$ 932

Loans - Summary of Past Due and

Loans - Summary of Past Due and Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Receivables [Abstract]
Total interest income that would have been recognized under original terms	$ 306	$ 226	$ 961	$ 703
Total cash received and recognized as interest income on non-accrual loans	117	203	156	253
Total interest income recognized on accruing, impaired loans	$ 8	$ 32	$ 55	$ 63

Loans - Narrative (Details)

Loans - Narrative (Details)	9 Months Ended
	Sep. 30, 2017USD ($)loan	Sep. 30, 2016USD ($)loan	Dec. 31, 2016USD ($)loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans over 90 days past due and still accruing interest | loan	0		0
Unadvanced commitments on impaired loans			$ 0
Specific reserves on restructured loans	$ 2,200,000
Restructuring Reserve	9,500,000
Unadvanced Commitment on Impaired Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Estimated losses attributable to unadvanced commitments on impaired loans	400,000		300,000
Non-Covered Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Post-Modification Outstanding Recorded Balance	$ 676,000	$ 2,609,000
Financing Receivable, Modifications, Number of Contracts | loan	1	4
Restructuring Reserve	$ 721,000		2,331,000
Financing Receivable, Gross	$ 3,949,856,000		3,119,154,000
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loan	3
Non-Covered Loans | Consumer and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Post-Modification Outstanding Recorded Balance	$ 0	$ 0
Financing Receivable, Modifications, Number of Contracts | loan	0	0
Restructuring Reserve	$ 0		0
Financing Receivable, Gross	$ 155,514,000		$ 156,182,000
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loan	0

Loans - Summary of Recorded I43

Loans - Summary of Recorded Investment in Impaired Portfolio Loans by Category (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)loan	Sep. 30, 2016loan	Dec. 31, 2016USD ($)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Restructured, not on non-accrual	$ 9,500
Impaired Financing Receivable, Related Allowance	1,200
Non-Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 8,985		$ 15,391
Financing Receivable, Modifications, Number of Contracts | loan	1	4
Non-accrual	$ 8,264		13,060
Restructured, not on non-accrual	721		2,331
Impaired Financing Receivable, Related Allowance	2,374		3,064
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	2,417		3,064
Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 7,451		12,357
Financing Receivable, Modifications, Number of Contracts | loan	1	2
Non-accrual	$ 6,730		10,046
Restructured, not on non-accrual	721		2,311
Impaired Financing Receivable, Related Allowance	2,020		2,909
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	2,063		2,909
Non-Covered Loans | Commercial - investor owned
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 544		435
Financing Receivable, Modifications, Number of Contracts | loan	0	1
Non-accrual	$ 544		435
Restructured, not on non-accrual	0		0
Impaired Financing Receivable, Related Allowance	120		0
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	120		0
Non-Covered Loans | Commercial - owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 0		231
Financing Receivable, Modifications, Number of Contracts | loan	0	0
Non-accrual	$ 0		231
Restructured, not on non-accrual	0		0
Impaired Financing Receivable, Related Allowance	0		0
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0		0
Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 322		2,306
Financing Receivable, Modifications, Number of Contracts | loan	0	1
Non-accrual	$ 322		2,286
Restructured, not on non-accrual	0		20
Impaired Financing Receivable, Related Allowance	186		155
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	186		155
Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Financing Receivable, Recorded Investment	668		62
Non-accrual	668		62
Restructured, not on non-accrual	0		0
Impaired Financing Receivable, Related Allowance	48		0
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	48		0
Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 0		0
Financing Receivable, Modifications, Number of Contracts | loan	0	0
Non-accrual	$ 0		0
Restructured, not on non-accrual	0		0
Impaired Financing Receivable, Related Allowance	0		0
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 0		$ 0

Loans - Summary of Recorded I44

Loans - Summary of Recorded Investment by Category for Portfolio Loans Restructured (Details) - Non-Covered Loans $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)loan	Sep. 30, 2016USD ($)loan
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	1	4
Pre-Modification Outstanding Recorded Balance	$ 676	$ 2,609
Post-Modification Outstanding Recorded Balance	$ 676	$ 2,609
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	1	2
Pre-Modification Outstanding Recorded Balance	$ 676	$ 2,341
Post-Modification Outstanding Recorded Balance	$ 676	$ 2,341
CRE - owner occupied
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	0
Pre-Modification Outstanding Recorded Balance	$ 0	$ 0
Post-Modification Outstanding Recorded Balance	$ 0	$ 0
Commercial Real Estate Investor Owned
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	1
Pre-Modification Outstanding Recorded Balance	$ 0	$ 248
Post-Modification Outstanding Recorded Balance	$ 0	$ 248
Construction and land development
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	1
Pre-Modification Outstanding Recorded Balance	$ 0	$ 20
Post-Modification Outstanding Recorded Balance	$ 0	$ 20
Residential Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	0
Pre-Modification Outstanding Recorded Balance	$ 0	$ 0
Post-Modification Outstanding Recorded Balance	$ 0	$ 0
Consumer and other
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	0
Pre-Modification Outstanding Recorded Balance	$ 0	$ 0
Post-Modification Outstanding Recorded Balance	$ 0	$ 0

Loans - Summary of Recorded I45

Loans - Summary of Recorded Investment by Category for Portfolio Loans Restructured and Subsequently Defaulted (Details) - Non-Covered Loans $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)loan
Schedule of Financing Receivables, Troubled Debt Restructurings - Suibsequent Defaults [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loan	3
Financing Receivable, Modifications, Pre-Modification Recorded Investment | $	$ 348
Commercial and industrial
Schedule of Financing Receivables, Troubled Debt Restructurings - Suibsequent Defaults [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loan	2
Financing Receivable, Modifications, Pre-Modification Recorded Investment | $	$ 343
CRE - owner occupied
Schedule of Financing Receivables, Troubled Debt Restructurings - Suibsequent Defaults [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loan	0
Financing Receivable, Modifications, Pre-Modification Recorded Investment | $	$ 0
Commercial Real Estate Investor Owned
Schedule of Financing Receivables, Troubled Debt Restructurings - Suibsequent Defaults [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loan	0
Financing Receivable, Modifications, Pre-Modification Recorded Investment | $	$ 0
Construction and land development
Schedule of Financing Receivables, Troubled Debt Restructurings - Suibsequent Defaults [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loan	0
Financing Receivable, Modifications, Pre-Modification Recorded Investment | $	$ 0
Residential Portfolio Segment [Member]
Schedule of Financing Receivables, Troubled Debt Restructurings - Suibsequent Defaults [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loan	1
Financing Receivable, Modifications, Pre-Modification Recorded Investment | $	$ 5
Consumer and other
Schedule of Financing Receivables, Troubled Debt Restructurings - Suibsequent Defaults [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loan	0
Financing Receivable, Modifications, Pre-Modification Recorded Investment | $	$ 0

Loans - Summary of Aging of Rec

Loans - Summary of Aging of Recorded Investment in Past Due Portfolio Loans by Portfolio Class and Category (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	$ 4,030,658	$ 3,158,161
Non-Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	12,426	999
90 or More Days Past Due	1,274	2,099
Total Past Due	13,700	3,098
Current	3,934,976	3,115,294
Loans and Leases Receivable, Gross	3,948,676	3,118,392
Total	3,949,856	3,119,154
Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	9,147	334
90 or More Days Past Due	283	171
Total Past Due	9,430	505
Current	1,851,855	1,632,209
Total	1,861,285	1,632,714
Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	266	212
90 or More Days Past Due	0	225
Total Past Due	266	437
Current	553,246	349,711
Total	553,512	350,148
Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	986	0
90 or More Days Past Due	0	175
Total Past Due	986	175
Current	737,000	544,633
Total	737,986	544,808
Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	355
90 or More Days Past Due	323	1,528
Total Past Due	323	1,883
Current	301,859	192,659
Total	302,182	194,542
Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	485	91
90 or More Days Past Due	668	0
Total Past Due	1,153	91
Current	338,224	240,669
Total	339,377	240,760
Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	1,542	7
90 or More Days Past Due	0	0
Total Past Due	1,542	7
Current	152,792	155,413
Loans and Leases Receivable, Gross	154,334	155,420
Total	$ 155,514	$ 156,182

Loans - Summary of Recorded I47

Loans - Summary of Recorded Investment by Risk Category of Portfolio Loans by Portfolio Class and Category (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	$ 4,030,658	$ 3,158,161
Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	3,949,856	3,119,154
Loans and Leases Receivable, Gross	3,948,676	3,118,392
Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	1,861,285	1,632,714
Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	553,512	350,148
Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	737,986	544,808
Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	302,182	194,542
Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	339,377	240,760
Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	155,514	156,182
Loans and Leases Receivable, Gross	154,334	155,420
Pass (1-6) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	3,723,164	2,909,234
Pass (1-6) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	1,708,153	1,499,114
Pass (1-6) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	513,939	306,658
Pass (1-6) | Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	720,912	530,494
Pass (1-6) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	298,613	185,505
Pass (1-6) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	328,434	233,479
Pass (1-6) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	153,113	153,984
Watch (7) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	143,648	116,686
Watch (7) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	90,885	57,416
Watch (7) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	33,249	39,249
Watch (7) | Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	12,592	10,449
Watch (7) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	2,558	6,575
Watch (7) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	3,989	2,997
Watch (7) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	375	0
Substandard (8) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	81,864	92,472
Substandard (8) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	62,247	76,184
Substandard (8) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	6,324	4,241
Substandard (8) | Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	4,482	3,865
Substandard (8) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	1,011	2,462
Substandard (8) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	6,954	4,284
Substandard (8) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	846	1,436
Doubtful (9) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	0	0
Doubtful (9) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	0	0
Doubtful (9) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	0	0
Doubtful (9) | Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	0	0
Doubtful (9) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	0	0
Doubtful (9) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	0	0
Doubtful (9) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Loans, before unearned loan fees	$ 0	$ 0

Purchased Credit Impaired ("P48

Purchased Credit Impaired ("PCI") Loans - Summary of PCI Loans by Category (Details) - Covered Loans $ in Thousands	Sep. 30, 2017USD ($)rating	Dec. 31, 2016USD ($)rating
Covered Loans [Line Items]
Recorded Investment PCI Loans	$ 81,982	$ 39,769
Construction and land development
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	5.93	5.80
Recorded Investment PCI Loans	$ 7,927	$ 4,365
Commercial Real Estate Investor Owned
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	7.29	6.95
Recorded Investment PCI Loans	$ 45,865	$ 8,162
CRE - owner occupied
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	6.50	6.39
Recorded Investment PCI Loans	$ 11,786	$ 11,863
Residential real estate
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	6.05	5.64
Recorded Investment PCI Loans	$ 12,661	$ 11,792
Total real estate loans
Covered Loans [Line Items]
Recorded Investment PCI Loans	$ 78,239	$ 36,182
Commercial and industrial
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	6.26	5.87
Recorded Investment PCI Loans	$ 3,676	$ 3,523
Consumer and other
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	2.99	1.64
Recorded Investment PCI Loans	$ 67	$ 64

Purchased Credit Impaired ("P49

Purchased Credit Impaired ("PCI") Loans - Summary of Aging of Recorded Investment in Past Due PCI Loans by Portfolio Class and Category (Details) - Covered Loans - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	$ 1,223	$ 169
90 or More Days Past Due	2,775	51
Total Past Due	3,998	220
Current	77,984	39,549
Total	81,982	39,769
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	0
90 or More Days Past Due	0	0
Total Past Due	0	0
Current	3,676	3,523
Total	3,676	3,523
CRE - owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	46	0
90 or More Days Past Due	909	0
Total Past Due	955	0
Current	10,831	11,863
Total	11,786	11,863
Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	429	0
90 or More Days Past Due	396	0
Total Past Due	825	0
Current	45,040	8,162
Total	45,865	8,162
Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	0
90 or More Days Past Due	478	0
Total Past Due	478	0
Current	7,449	4,365
Total	7,927	4,365
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	748	169
90 or More Days Past Due	992	51
Total Past Due	1,740	220
Current	10,921	11,572
Total	12,661	11,792
Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	0
90 or More Days Past Due	0	0
Total Past Due	0	0
Current	67	64
Total	$ 67	$ 64

Purchased Credit Impaired ("P50

Purchased Credit Impaired ("PCI") Loans - Rollforward of PCI Loans, Net of Allowance for Loan Losses (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 33,925	$ 64,583
Acquisitions	49,155
Principal reductions and interest payments	(16,319)	(20,417)
Accretion of loan discount	5,473	4,984
Changes in contractual and expected cash flows due to remeasurement	8,036	9,262
Reductions due to disposals	(3,186)	(17,396)
Balance at end of period	77,084	41,016
Contractual Cashflows
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	66,003	116,689
Acquisitions	68,763
Principal reductions and interest payments	(16,319)	(20,417)
Accretion of loan discount	0	0
Changes in contractual and expected cash flows due to remeasurement	11,110	9,194
Reductions due to disposals	(6,393)	(27,888)
Balance at end of period	123,164	77,578
Non-accretable Difference
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	18,902	26,765
Acquisitions	14,296
Principal reductions and interest payments	0	0
Accretion of loan discount	0	0
Changes in contractual and expected cash flows due to remeasurement	(702)	975
Reductions due to disposals	(1,612)	(6,779)
Balance at end of period	30,884	20,961
Accretable Yield
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	13,176	25,341
Acquisitions	5,312
Principal reductions and interest payments	0	0
Accretion of loan discount	5,473	4,984
Changes in contractual and expected cash flows due to remeasurement	3,776	(1,043)
Reductions due to disposals	(1,595)	(3,713)
Balance at end of period	$ 15,196	$ 15,601

Purchased Credit Impaired ("P51

Purchased Credit Impaired ("PCI") Loans - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Receivables [Abstract]
PCI loans outstanding	$ 107.8	$ 54.6

Commitments (Details)

Commitments (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Schedule of Commitments [Line Items]
Unadvanced commitments on impaired loans		$ 0
Commitments to extend credit
Schedule of Commitments [Line Items]
Off-balance sheet financial instruments, contractual amounts	$ 1,263,809	1,075,170
Letters of credit
Schedule of Commitments [Line Items]
Off-balance sheet financial instruments, contractual amounts	$ 74,007	78,954
Letters of credit | Maximum
Schedule of Commitments [Line Items]
Remaining term	4 years
Letters of credit | Minimum
Schedule of Commitments [Line Items]
Remaining term	1 month
Unadvanced Commitment on Impaired Loan
Schedule of Commitments [Line Items]
Estimated losses attributable to unadvanced commitments on impaired loans	$ 400	300
Fixed Rate Loan Commitment | Commitments to extend credit
Schedule of Commitments [Line Items]
Off-balance sheet financial instruments, contractual amounts	$ 113,100	$ 89,700

Derivative Financial Instrume53

Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Risk Management [Member]
Summary of Derivative Instruments [Abstract]
Notional Amount	$ 0	$ 3,500
Derivative, Fair Value, Net	0	0
Non-designated hedging instruments | Client-Related | Interest rate swap contracts
Summary of Derivative Instruments [Abstract]
Notional Amount	270,542	124,322
Non-designated hedging instruments | Client-Related | Foreign Exchange Forward [Member]
Summary of Derivative Instruments [Abstract]
Notional Amount	1,376	3,034
Non-designated hedging instruments | Client-Related | Other Assets | Interest rate swap contracts
Summary of Derivative Instruments [Abstract]
Asset derivatives (other assets), fair value	1,902	982
Non-designated hedging instruments | Client-Related | Other Assets | Foreign Exchange Forward [Member]
Summary of Derivative Instruments [Abstract]
Asset derivatives (other assets), fair value	1,376	3,034
Non-designated hedging instruments | Client-Related | Other Liabilities | Interest rate swap contracts
Summary of Derivative Instruments [Abstract]
Liability derivatives (other liabilities), fair value	1,902	982
Non-designated hedging instruments | Client-Related | Other Liabilities | Foreign Exchange Forward [Member]
Summary of Derivative Instruments [Abstract]
Liability derivatives (other liabilities), fair value	$ 1,376	$ 3,034

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets
Securities available for sale	$ 603,121	$ 460,797
State tax credits held for sale	1,274	3,585
Portion at Other than Fair Value, Fair Value Disclosure
Assets
State tax credits held for sale	34,000
Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	603,121	460,797
State tax credits held for sale	37,781	41,264
Derivative financial instruments	3,278	4,016
Liabilities
Derivative financial instruments	3,278	4,016
Obligations of U.S. Government-sponsored enterprises
Assets
Securities available for sale	100,123	107,660
Obligations of states and political subdivisions
Assets
Securities available for sale	33,342	36,631
Residential mortgage-backed securities
Assets
Securities available for sale	469,656	316,506
Recurring basis | Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	603,121	460,797
State tax credits held for sale	1,274	3,585
Derivative financial instruments	3,278	4,016
Total assets	607,673	468,398
Liabilities
Derivative financial instruments		4,016
Total liabilities	3,278	4,016
Recurring basis | Obligations of U.S. Government-sponsored enterprises | Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	100,123	107,660
Recurring basis | Obligations of states and political subdivisions | Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	33,341	36,631
Recurring basis | Residential mortgage-backed securities | Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	469,657	316,506
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	0	0
State tax credits held for sale	0	0
Derivative financial instruments	0	0
Total assets	0	0
Liabilities
Derivative financial instruments	0	0
Total liabilities	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Obligations of U.S. Government-sponsored enterprises
Assets
Securities available for sale	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Obligations of states and political subdivisions
Assets
Securities available for sale	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Residential mortgage-backed securities
Assets
Securities available for sale	0	0
Recurring basis | Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	603,121	457,708
State tax credits held for sale	0	0
Derivative financial instruments	3,278	4,016
Total assets	606,399	461,724
Liabilities
Derivative financial instruments	3,278	4,016
Total liabilities	3,278	4,016
Recurring basis | Significant Other Observable Inputs (Level 2) | Obligations of U.S. Government-sponsored enterprises
Assets
Securities available for sale	100,123	107,660
Recurring basis | Significant Other Observable Inputs (Level 2) | Obligations of states and political subdivisions
Assets
Securities available for sale	33,341	33,542
Recurring basis | Significant Other Observable Inputs (Level 2) | Residential mortgage-backed securities
Assets
Securities available for sale	469,657	316,506
Recurring basis | Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	0	3,089
State tax credits held for sale	1,274	3,585
Derivative financial instruments	0	0
Total assets	1,274	6,674
Liabilities
Derivative financial instruments	0	0
Total liabilities	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Obligations of U.S. Government-sponsored enterprises
Assets
Securities available for sale	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Obligations of states and political subdivisions
Assets
Securities available for sale	0	3,089
Recurring basis | Significant Unobservable Inputs (Level 3) | Residential mortgage-backed securities
Assets
Securities available for sale	$ 0	$ 0

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)security	Dec. 31, 2016USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
State tax credits, held for sale	$ 35,291	$ 38,071
State Tax Credits Held For Sale, Fair Value Disclosure	$ 1,274	3,585
State Tax Credit Term	10 years
Years of Tax Credits Generated	10 years
Receivables, Fair Value Disclosure	$ 3,900
Impaired Financing Receivable, Related Allowance	1,200
Recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
State tax credits, held for sale	35,300
Recurring basis | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
State Tax Credits Held For Sale, Fair Value Disclosure	$ 1,274	3,585
Auction Rate Securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of available-for-sale securities | security	0
Portion at Other than Fair Value, Fair Value Disclosure
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
State Tax Credits Held For Sale, Fair Value Disclosure	$ 34,000
Estimated fair value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
State Tax Credits Held For Sale, Fair Value Disclosure	37,781	41,264
Estimated fair value | Recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
State Tax Credits Held For Sale, Fair Value Disclosure	$ 1,274	$ 3,585
LIBOR | LIBOR Swap Curve [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate basis spread on variable rate	205.00%
LIBOR Swap Curve [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate basis point spread	205

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - Level 3 - Recurring basis - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Securities available for sale, at fair value
Level 3 Financial Instruments Measured at Fair Value
Beginning balance	$ 0	$ 3,093	$ 3,089	$ 3,077
Total gains:
Included in other comprehensive income	0	1	4	17
Purchases, sales, issuances and settlements:
Purchases	0	0	0	0
Transfer in and/or out of Level 3	0	0	(3,093)	0
Ending balance	0	3,094	0	3,094
Change in unrealized gains relating to assets still held at the reporting date	0	1	0	17
State tax credits held for sale, at fair value
Level 3 Financial Instruments Measured at Fair Value
Beginning balance	1,274	4,774	3,585	5,941
Total gains:
Total gains:	0	27	49	144
Purchases, sales, issuances and settlements:
Sales	0	0	(2,360)	(1,284)
Ending balance	1,274	4,801	1,274	4,801
Change in unrealized gains relating to assets still held at the reporting date	$ 0	$ 27	$ (655)	$ (237)

Fair Value Measurements - Sum57

Fair Value Measurements - Summary of Financial Instruments and Non-Financial Assets Measured at Fair Value on a Non-Recurring Basis (Details) - Fair Value, Measurements, Nonrecurring $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017USD ($)	Sep. 30, 2017USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total (losses) gains for the year	$ 651	$ 5,914
Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total (losses) gains for the year	613	5,876
Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total (losses) gains for the year	38	38
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Significant Other Observable Inputs (Level 2) | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Significant Other Observable Inputs (Level 2) | Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	2,769	2,769
Significant Unobservable Inputs (Level 3) | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	2,743	2,743
Significant Unobservable Inputs (Level 3) | Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	26	26
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	2,769	2,769
Estimate of Fair Value Measurement [Member] | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	2,743	2,743
Estimate of Fair Value Measurement [Member] | Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	$ 26	$ 26

Fair Value Measurements - Sum58

Fair Value Measurements - Summary of Carrying Amount and Fair Values of Financial Instruments Reported on the Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Balance sheet assets
Securities available for sale	$ 603,121	$ 460,797
Securities held to maturity	76,168	80,463
State tax credits held for sale	1,274	3,585
Carrying Amount
Balance sheet assets
Cash and due from banks	76,777	54,288
Federal funds sold	1,155	446
Interest-bearing deposits	107,821	145,048
Securities available for sale	603,121	460,797
Securities held to maturity	76,168	80,463
Other investments, at cost	29,436	14,840
Loans held for sale	6,411	9,562
Derivative financial instruments	3,278	4,016
Loans, net	3,987,467	3,114,752
State tax credits held for sale	35,291	38,071
Accrued interest receivable	14,213	11,117
Balance sheet liabilities
Deposits	4,059,211	3,233,361
Subordinated debentures and notes	118,093	105,540
Federal Home Loan Bank advances	248,868	0
Other borrowings	219,104	276,980
Derivative financial instruments	3,278	4,016
Accrued interest payable	2,007	1,105
Estimated fair value
Balance sheet assets
Cash and due from banks	76,777	54,288
Federal funds sold	1,155	446
Interest-bearing deposits	107,821	145,048
Securities available for sale	603,121	460,797
Securities held to maturity	76,260	79,639
Other investments, at cost	29,436	14,840
Loans held for sale	6,411	9,562
Derivative financial instruments	3,278	4,016
Loans, net	4,009,071	3,125,701
State tax credits held for sale	37,781	41,264
Accrued interest receivable	14,213	11,117
Balance sheet liabilities
Deposits	4,057,561	3,232,414
Subordinated debentures and notes	100,062	86,052
Federal Home Loan Bank advances	249,168	0
Other borrowings	219,012	276,905
Derivative financial instruments	3,278	4,016
Accrued interest payable	$ 2,007	$ 1,105

Fair Value Measurements - Sch59

Fair Value Measurements - Schedule of Estimated Fair Values of Financial Instruments Not Recorded at Fair Value on Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Estimated fair value | Securities held to maturity
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial assets not on condensed consolidated balance sheets at fair value	$ 76,260	$ 79,639
Estimated fair value | Portfolio loans, net
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial assets not on condensed consolidated balance sheets at fair value	4,009,071	3,125,701
Estimated fair value | State tax credits, held for sale
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial assets not on condensed consolidated balance sheets at fair value	36,508	37,679
Estimated fair value | Deposits
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	4,057,561	3,232,414
Estimated fair value | Subordinated debentures and notes
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	100,062	86,052
Estimated fair value | Federal Home Loan Bank advances
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	249,168
Estimated fair value | Other Borrowings
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	219,012	276,905
Level 1 | Securities held to maturity
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial assets not on condensed consolidated balance sheets at fair value	0	0
Level 1 | Portfolio loans, net
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial assets not on condensed consolidated balance sheets at fair value	0	0
Level 1 | State tax credits, held for sale
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial assets not on condensed consolidated balance sheets at fair value	0	0
Level 1 | Deposits
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	3,442,015	2,760,202
Level 1 | Subordinated debentures and notes
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	0	0
Level 1 | Federal Home Loan Bank advances
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	0
Level 1 | Other Borrowings
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	0	0
Level 2 | Securities held to maturity
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial assets not on condensed consolidated balance sheets at fair value	76,260	79,639
Level 2 | Portfolio loans, net
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial assets not on condensed consolidated balance sheets at fair value	0	0
Level 2 | State tax credits, held for sale
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial assets not on condensed consolidated balance sheets at fair value	0	0
Level 2 | Deposits
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	0	0
Level 2 | Subordinated debentures and notes
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	100,062	86,052
Level 2 | Federal Home Loan Bank advances
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	249,168
Level 2 | Other Borrowings
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	219,012	276,905
Level 3 | Securities held to maturity
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial assets not on condensed consolidated balance sheets at fair value	0	0
Level 3 | Portfolio loans, net
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial assets not on condensed consolidated balance sheets at fair value	4,009,071	3,125,701
Level 3 | State tax credits, held for sale
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial assets not on condensed consolidated balance sheets at fair value	36,508	37,679
Level 3 | Deposits
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	615,546	472,212
Level 3 | Subordinated debentures and notes
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	0	0
Level 3 | Federal Home Loan Bank advances
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	0
Level 3 | Other Borrowings
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	$ 0	$ 0