Enterprise Financial Services (EFSC) 10-Q 28 Apr 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 26, 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	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		23,481,668

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 73,387	$ 54,288
Federal funds sold	1,112	446
Interest-bearing deposits (including $2,011 and $675 pledged as collateral)	134,502	144,068
Total cash and cash equivalents	209,001	198,802
Interest-bearing deposits greater than 90 days	2,695	980
Securities available for sale	593,685	460,797
Securities held to maturity	79,236	80,463
Loans held for sale	5,380	9,562
Loans	3,891,064	3,158,161
Less: Allowance for loan losses	44,625	43,409
Total loans, net	3,846,439	3,114,752
Other real estate	2,925	980
Other investments, at cost	24,222	14,840
Fixed assets, net	34,291	14,910
Accrued interest receivable	12,229	11,117
State tax credits held for sale (including $1,458 and $3,585 carried at fair value)	35,431	38,071
Goodwill	113,886	30,334
Intangible assets, net	11,758	2,151
Other assets	135,048	103,569
Total assets	5,106,226	4,081,328
Liabilities and Shareholders' Equity
Demand deposits	1,037,001	866,756
Interest-bearing transaction accounts	844,775	731,539
Money market accounts	1,354,434	1,050,472
Savings	189,303	111,435
Certificates of deposit:
Brokered	145,436	117,145
Other	460,671	356,014
Total deposits	4,031,620	3,233,361
Subordinated debentures and notes (net of debt issuance cost of $1,234 and $1,267)	118,067	105,540
Federal Home Loan Bank advances	151,115	0
Other borrowings	235,052	276,980
Accrued interest payable	1,914	1,105
Other liabilities	30,537	77,244
Total liabilities	4,568,305	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; 23,699,453 and 20,306,353 shares issued	237	203
Treasury stock, at cost; 261,718 shares	(6,632)	(6,632)
Additional paid in capital	348,259	213,078
Retained earnings	197,231	182,190
Accumulated other comprehensive income	(1,174)	(1,741)
Total shareholders' equity	537,921	387,098
Total liabilities and shareholders' equity	$ 5,106,226	$ 4,081,328

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Assets
Collateral pledged	$ 2,011	$ 675
Allowance for loan losses on Portfolio loans, covered under FDIC loss share	5,477	5,844
State tax credits held for sale	1,458	3,585
Debt Issuance Cost	$ 1,234	$ 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	23,699,453	20,306,353
Treasury stock, shares	261,718	261,718

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Interest income:
Interest and fees on loans	$ 39,926	$ 32,608
Interest on debt securities:
Taxable	3,230	2,387
Nontaxable	386	332
Interest on interest-bearing deposits	130	61
Dividends on equity securities	68	72
Total interest income	43,740	35,460
Interest expense:
Interest-bearing transaction accounts	675	306
Money market accounts	1,493	1,006
Savings accounts	82	60
Certificates of deposit	1,215	1,019
Subordinated debentures and notes	1,164	348
Federal Home Loan Bank advances	330	182
Notes payable and other borrowings	139	111
Total interest expense	5,098	3,032
Net interest income	38,642	32,428
Provision for portfolio loan losses	1,533	833
Provision reversal for purchased credit impaired loan losses	(148)	(73)
Net interest income after provision for loan losses	37,257	31,668
Noninterest income:
Service charges on deposit accounts	2,510	2,043
Wealth management revenue	1,833	1,662
Other service charges and fee income	1,280	868
Gain on state tax credits, net	246	518
Gain on sale of other real estate	0	122
Miscellaneous income	1,107	792
Total noninterest income	6,976	6,005
Noninterest expense:
Employee compensation and benefits	15,208	12,647
Occupancy	1,929	1,683
Data processing	1,633	1,104
Professional fees	837	684
FDIC and other insurance	824	723
Loan legal and other real estate expense	345	357
Merger related expenses	1,667	0
Other	4,293	3,564
Total noninterest expense	26,736	20,762
Income before income tax expense	17,497	16,911
Income tax expense	5,106	5,886
Net income	$ 12,391	$ 11,025
Earnings per common share
Basic (usd per share)	$ 0.57	$ 0.55
Diluted (usd per share)	$ 0.56	$ 0.54

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 12,391	$ 11,025
Other comprehensive income, net of tax:
Unrealized gains on investment securities arising during the period, net of income tax expense for three months of $348 and $2,304, respectively	567	3,711
Total other comprehensive income	567	3,711
Total comprehensive income	$ 12,958	$ 14,736

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Other comprehensive income, tax:
Unrealized (loss)/gain on investment securities available for sale arising during the period, tax	$ 348	$ 2,304
Reclassification adjustment for realized gains on sale of securities available for sale included in net income, tax	$ 0	$ 0

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	11,025	0	0	0	0	11,025	0
Other comprehensive income	3,711	0	0	0	0	0	3,711
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	14,736
Cash dividends paid on common shares	1,802	0	0	0	0	(1,802)	0
Adjustments To Additional Paid In Capital, Repurchase Of Common Stock Warrants	(4,211)	0	0	(4,211)	0	0	0
Issuance under equity compensation plans, net	(1,745)	0	(1)	0	1,746	0	0
Share-based Compensation	794	0	0	0	794	0	0
Excess tax benefit related to equity compensation plans	783	0	0	0	783	0	0
Balance at Mar. 31, 2016	359,384	0	202	(5,954)	210,420	150,787	3,929
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	12,391	0	0	0	0	12,391	0
Other comprehensive income	567	0	0	0	0	0	567
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	12,958	0	0	0	0	(12,391)	(567)
Cash dividends paid on common shares	2,579	0	0	0	0	(2,579)	0
Issuance under equity compensation plans, net	(2,151)	0	(1)	0	2,152	0	0
Share-based Compensation	866	0	0	0	866	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 Mar. 31, 2017	$ 537,921	$ 0	$ 237	$ (6,632)	$ 348,259	$ 197,231	$ (1,174)

Condensed Consolidated Stateme8

Condensed Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash dividends paid on common shares, per share	$ 0.11	$ 0.09
Issuance under equity compensation plans, shares	93,236	136,010
Stock Issued During Period, Shares, Conversion of Convertible Securities	0	0

Condensed Consolidated Stateme9

Condensed Consolidated Statements of Cash Flows $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)	Mar. 31, 2016USD ($)
Cash flows from operating activities:
Net income	$ 12,391	$ 11,025
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation	387	535
Provision for loan losses	1,385	760
Deferred income taxes	962	1,343
Net amortization of debt securities	1,310	721
Amortization of intangible assets	446	243
Mortgage loans originated for sale	(38,602)	(29,287)
Proceeds from mortgage loans sold	42,710	29,606
Gain on sale of other real estate	0	(122)
Gain on state tax credits, net	(246)	(518)
Excess tax benefit of share-based compensation	0	(783)
Share-based Compensation	866	794
Valuation adjustment on other real estate	18	1
Net accretion of loan discount and indemnification asset	(1,014)	(2,249)
Changes in:
Accrued interest receivable	1,682	(398)
Accrued interest payable	156	(87)
Other assets	(1,746)	(9,303)
Other liabilities	(51,693)	1,837
Net cash (used in) provided by operating activities	(30,988)	4,118
Cash flows from investing activities:
Proceeds from Previous Acquisition	6,171	0
Net increase in loans	(57,054)	(71,324)
Proceeds from the sale of securities, available for sale	143,554	0
Proceeds from the paydown or maturity of securities, available for sale	42,223	12,894
Proceeds from the paydown or maturity of securities, held to maturity	1,180	431
Proceeds from the redemption of other investments	12,033	17,653
Proceeds from the sale of state tax credits held for sale	4,093	3,412
Proceeds from the sale of other real estate	0	671
Payments for the purchase/origination of:
Available for sale debt and equity securities	(169,842)	(17,637)
Other investments	(20,318)	(19,430)
State tax credits held for sale	(1,298)	(2,349)
Fixed assets	(247)	(505)
Net cash used in investing activities	(39,505)	(76,184)
Cash flows from financing activities:
Net increase in noninterest-bearing deposit accounts	9,646	2,192
Net increase in interest-bearing deposit accounts	23,316	144,963
Proceeds from Federal Home Loan Bank advances	681,181	509,000
Repayments of Federal Home Loan Bank advances	(530,681)	(488,500)
Net decrease in other borrowings	(98,040)	(76,538)
Dividends, Common Stock, Cash	(2,579)	(1,802)
Excess tax benefit of share-based compensation	0	783
Payments for Repurchase of Common Stock	0	4,211
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	(2,151)	(1,745)
Net cash provided by financing activities	80,692	84,142
Net increase in cash and cash equivalents	10,199	12,076
Cash and cash equivalents, beginning of period	198,802	94,157
Cash and cash equivalents, end of period	209,001	106,233
Supplemental Cash Flow Information [Abstract]
Cash paid during the period for interest	4,289	3,119
Cash paid during the period for income taxes	28	14,084
Noncash transactions:
Transfer to other real estate owned in settlement of loans	0	2,683
Sales of other real estate financed	$ 0	$ 140
Common shares issued related to acquisition	141,729

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 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 months ended March 31, 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 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 $1.3 million for the three months ended March 31, 2017. Excess tax benefits related to stock compensation are presented as a cash inflow from operating activities for the three months ended March 31, 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 indentifiable 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.

Acquisitions & Divestitures

Acquisitions & Divestitures	3 Months Ended
	Mar. 31, 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 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 $1.7 million and $1.4 million of merger related costs that were recorded in noninterest expense in the statement of operations for the three months ended March 31, 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. The estimates of fair value are preliminary and subject to refinement as the Company completes its evaluation of the acquired assets and liabilities. Goodwill of $83.6 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, except shares data) As Recorded by JCB Adjustments As Recorded by EFSC Assets acquired: Cash and cash equivalents $ 35,454 $ — $ 35,454 Securities 148,670 — 148,670 Portfolio loans, net 685,905 (10,619 ) (a) 675,286 Other real estate owned 6,762 (5,082 ) (b) 1,680 Other investments 2,695 — 2,695 Fixed assets, net 21,780 (2,259 ) (c) 19,521 Accrued interest receivable 2,794 — 2,794 Goodwill 7,806 (7,806 ) (d) — Other intangible assets 25 10,028 (e) 10,053 Deferred tax assets 4,634 7,086 (f) 11,720 Other assets 19,159 — 19,159 Total assets acquired $ 935,684 $ (8,652 ) $ 927,032 Liabilities assumed: Deposits $ 764,668 $ 629 (g) $ 765,297 Other borrowings 55,430 681 (h) 56,111 Trust preferred securities 12,887 (382 ) (i) 12,505 Accrued interest payable 653 — 653 Other liabilities 5,006 — 5,006 Total liabilities assumed $ 838,644 $ 928 $ 839,572 Net assets acquired $ 97,040 $ (9,580 ) $ 87,460 Consideration paid: Cash $ 29,283 Common stock 141,729 Total consideration paid $ 171,012 Goodwill $ 83,552 (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 $24.2 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. (d) Eliminate JCB’s recorded goodwill. (e) Recording of 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. (g) Fair value adjustment to time deposits based on current interest rates. (h) Fair value adjustment to the FHLB advances based on current interest rates. (i) Fair value adjustment based on the Company's evaluation of the trust preferred securities. The following table provides the unaudited pro forma information for the results of operations for the three months ended March 31, 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 March 31, 2017 are included in net income in the table below. Pro Forma Three months ended March 31, (in thousands, except per share data) 2017 2016 Total revenues (net interest income plus noninterest income) $ 49,598 $ 47,275 Net income 13,054 12,961 Diluted earnings per common share 0.55 0.55

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 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 March 31, (in thousands, except per share data) 2017 2016 Net income as reported $ 12,391 $ 11,025 Weighted average common shares outstanding 21,928 20,004 Additional dilutive common stock equivalents 381 229 Weighted average diluted common shares outstanding 22,309 20,233 Basic earnings per common share: $ 0.57 $ 0.55 Diluted earnings per common share: $ 0.56 $ 0.54 For the three months ended March 31, 2017 and 2016 , there were no common stock equivalents excluded from the earnings per share calculations because their effect was anti-dilutive.

Investments

Investments	3 Months Ended
	Mar. 31, 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: March 31, 2017 (in thousands) Amortized Cost Gross Gross Fair Value Available for sale securities: Obligations of U.S. Government-sponsored enterprises $ 104,979 $ 262 $ (66 ) $ 105,175 Obligations of states and political subdivisions 34,113 762 (365 ) 34,510 Agency mortgage-backed securities 431,030 1,508 (3,537 ) 429,001 U.S Treasury bills 24,998 1 — 24,999 Total securities available for sale $ 595,120 $ 2,533 $ (3,968 ) $ 593,685 Held to maturity securities: Obligations of states and political subdivisions $ 14,741 $ 33 $ (99 ) $ 14,675 Agency mortgage-backed securities 64,495 76 (629 ) 63,942 Total securities held to maturity $ 79,236 $ 109 $ (728 ) $ 78,617 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 March 31, 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 $466.1 million and $407.3 million at March 31, 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 March 31, 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 5 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 $ 27,529 $ 27,563 $ 657 $ 656 Due after one year through five years 94,131 94,743 7,056 7,043 Due after five years through ten years 14,532 14,759 6,523 6,479 Due after ten years 2,900 2,620 505 497 Agency mortgage-backed securities 431,030 429,001 64,495 63,942 U.S Treasury bills 24,998 24,999 — — $ 595,120 $ 593,685 $ 79,236 $ 78,617 The following table represents a summary of investment securities that had an unrealized loss: March 31, 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 $ 20,110 $ 66 $ — $ — $ 20,110 $ 66 Obligations of states and political subdivisions $ 14,371 $ 152 $ 3,559 $ 312 $ 17,930 $ 464 Agency mortgage-backed securities 298,238 3,686 13,311 480 311,549 4,166 $ 332,719 $ 3,904 $ 16,870 $ 792 $ 349,589 $ 4,696 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 March 31, 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 March 31, 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	3 Months Ended
	Mar. 31, 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. March 31, 2017 December 31, 2016 Loans not accounted for as ASC 310-30 $ 3,802,681 $ 3,118,392 Loans accounted for as ASC 310-30 88,383 39,769 Total loans $ 3,891,064 $ 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 March 31, 2017 and December 31, 2016 : (in thousands) March 31, 2017 December 31, 2016 Commercial and industrial $ 1,773,105 $ 1,632,714 Real estate: Commercial - investor owned 726,413 544,808 Commercial - owner occupied 480,281 350,148 Construction and land development 288,342 194,542 Residential 356,415 240,760 Total real estate loans 1,851,451 1,330,258 Consumer and other 179,100 156,182 Loans, before unearned loan fees 3,803,656 3,119,154 Unearned loan fees, net (975 ) (762 ) Loans, including unearned loan fees $ 3,802,681 $ 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 method through March 31, 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 (in thousands) Commercial and industrial CRE - investor owned CRE - owner occupied Construction and land development Residential real estate Consumer and other Total Balance March 31, 2017 Allowance for loan losses - Ending balance: Individually evaluated for impairment $ 5,047 $ — $ — $ 140 $ — $ — $ 5,187 Collectively evaluated for impairment 23,731 3,324 2,730 1,162 2,036 978 33,961 Total $ 28,778 $ 3,324 $ 2,730 $ 1,302 $ 2,036 $ 978 $ 39,148 Loans - Ending balance: Individually evaluated for impairment $ 12,152 $ 281 $ 1,591 $ 1,575 $ 61 $ — $ 15,660 Collectively evaluated for impairment 1,760,953 726,132 478,690 286,767 356,354 178,125 3,787,021 Total $ 1,773,105 $ 726,413 $ 480,281 $ 288,342 $ 356,415 $ 178,125 $ 3,802,681 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 loans individually evaluated for impairment by category at March 31, 2017 and December 31, 2016 , is as follows: March 31, 2017 (in thousands) Unpaid Recorded Recorded Allowance Total Related Allowance Average Commercial and industrial $ 11,930 $ 40 $ 11,963 $ 12,003 $ 5,047 $ 12,017 Real estate: Commercial - investor owned 281 282 — 282 — 272 Commercial - owner occupied — — — — — — Construction and land development 1,575 1,658 341 1,999 140 1,813 Residential 62 62 — 62 — 62 Consumer and other — — — — — — Total $ 13,848 $ 2,042 $ 12,304 $ 14,346 $ 5,187 $ 14,164 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 The following table presents details for past due and impaired loans: Three months ended March 31, (in thousands) 2017 2016 Total interest income that would have been recognized under original terms $ 315 $ 148 Total cash received and recognized as interest income on non-accrual loans 23 6 Total interest income recognized on impaired loans 33 6 There were no loans over 90 days past due and still accruing interest at March 31, 2017 or December 31, 2016 . The recorded investment in impaired loans by category at March 31, 2017 and December 31, 2016 , is as follows: March 31, 2017 (in thousands) Non-accrual Restructured Loans over 90 days past due and still accruing interest Total Commercial and industrial $ 9,692 $ 2,311 $ — $ 12,003 Real estate: Commercial - investor owned 282 — — 282 Commercial - owner occupied — — — — Construction and land development 1,979 20 — 1,999 Residential 62 — — 62 Consumer and other — — — — Total $ 12,015 $ 2,331 $ — $ 14,346 December 31, 2016 (in thousands) Non-accrual Restructured Loans over 90 days past due and still accruing interest 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 restructured loans during the three months ended March 31, 2017 and 2016 . As of March 31, 2017 , the Company had $0.7 million specific reserves allocated to loans that have been restructured. There were no loans restructured that subsequently defaulted during the three months ended March 31, 2017 or 2016 . The aging of the recorded investment in past due loans by portfolio class and category at March 31, 2017 and December 31, 2016 is shown below. March 31, 2017 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ 10,624 $ — $ 10,624 $ 1,762,481 $ 1,773,105 Real estate: Commercial - investor owned 708 — 708 725,705 726,413 Commercial - owner occupied 529 — 529 479,752 480,281 Construction and land development — 1,214 1,214 287,128 288,342 Residential 285 — 285 356,130 356,415 Consumer and other 2 — 2 178,123 178,125 Total $ 12,148 $ 1,214 $ 13,362 $ 3,789,319 $ 3,802,681 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 March 31, 2017 , which is based upon the most recent analysis performed, and December 31, 2016 is as follows: March 31, 2017 (in thousands) Pass (1-6) Watch (7) Substandard (8) Doubtful (9) Total Commercial and industrial $ 1,629,105 $ 75,946 $ 68,054 $ — $ 1,773,105 Real estate: Commercial - investor owned 706,958 15,777 3,678 — 726,413 Commercial - owner occupied 440,319 35,505 4,457 — 480,281 Construction and land development 283,410 2,841 2,091 — 288,342 Residential 347,118 5,051 4,246 — 356,415 Consumer and other 176,340 375 1,410 — 178,125 Total $ 3,583,250 $ 135,495 $ 83,936 $ — $ 3,802,681 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	3 Months Ended
	Mar. 31, 2017
Receivables [Abstract]
Purchase Credit Impaired (PCI) Loans	The following tables refer to loans accounted for using ASC 310-30 (purchased credit impaired loans): Below is a summary of PCI loans by category at March 31, 2017 and December 31, 2016 : March 31, 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 5.84 $ 4,335 5.87 $ 3,523 Real estate: Commercial - investor owned 7.00 42,532 6.95 8,162 Commercial - owner occupied 6.47 13,580 6.39 11,863 Construction and land development 6.18 12,914 5.80 4,365 Residential 6.06 14,943 5.64 11,792 Total real estate loans 83,969 36,182 Consumer and other 3.50 79 1.64 64 Purchased credit impaired loans $ 88,383 $ 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 March 31, 2017 and December 31, 2016 is shown below: March 31, 2017 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ — $ 21 $ 21 $ 4,314 $ 4,335 Real estate: Commercial - investor owned — — — 42,532 42,532 Commercial - owner occupied — — — 13,580 13,580 Construction and land development — — — 12,914 12,914 Residential 403 29 432 14,511 14,943 Consumer and other — — — 79 79 Total $ 403 $ 50 $ 453 $ 87,930 $ 88,383 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 three months ended March 31, 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 70,435 11,669 8,550 50,216 Principal reductions and interest payments (4,310 ) — — (4,310 ) Accretion of loan discount — — (1,389 ) 1,389 Changes in contractual and expected cash flows due to remeasurement 3,166 (307 ) 1,165 2,308 Reductions due to disposals (1,341 ) (345 ) (264 ) (732 ) Balance March 31, 2017 $ 133,953 $ 29,919 $ 21,238 $ 82,796 Balance December 31, 2015 $ 116,689 $ 26,765 $ 25,341 $ 64,583 Principal reductions and interest payments (5,965 ) — — (5,965 ) Accretion of loan discount — — (1,845 ) 1,845 Changes in contractual and expected cash flows due to remeasurement 4,012 2,375 (1,032 ) 2,669 Reductions due to disposals (12,869 ) (2,127 ) (1,518 ) (9,224 ) Balance March 31, 2016 $ 101,867 $ 27,013 $ 20,946 $ 53,908 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 $119.1 million and $54.6 million as of March 31, 2017 , and December 31, 2016 , respectively.

Derivative Financial Instrument

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 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 March 31, 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) March 31, December 31, March 31, December 31, March 31, December 31, Non-designated hedging instruments Interest rate swap contracts $ 153,069 $ 124,322 $ 1,449 $ 982 $ 1,449 $ 982 Foreign exchange forward contracts 3,954 3,034 3,954 3,034 3,954 3,034 Changes in the fair value of client-related derivative instruments are recognized currently in operations. For the three months ended March 31, 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.

Commitments

Commitments	3 Months Ended
	Mar. 31, 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 March 31, 2017 , there were no unadvanced commitments on impaired loans. The contractual amounts of off-balance-sheet financial instruments as of March 31, 2017 , and December 31, 2016 , are as follows: (in thousands) March 31, 2017 December 31, 2016 Commitments to extend credit $ 1,193,968 $ 1,075,170 Letters of credit 79,719 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 March 31, 2017 , and December 31, 2016 , approximately $115 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 include $0.3 million for estimated losses attributable to the unadvanced commitments at March 31, 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 March 31, 2017, the approximate remaining term of standby letters of credit range from 1 month to 4 years and 6 months . 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.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 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 March 31, 2017 and December 31, 2016 , segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: March 31, 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 $ — $ 105,175 $ — $ 105,175 Obligations of states and political subdivisions — 31,417 3,093 34,510 Residential mortgage-backed securities — 429,001 — 429,001 U.S. Treasury Bills 24,999 — — 24,999 Total securities available for sale $ 24,999 $ 565,593 $ 3,093 $ 593,685 State tax credits held for sale — — 1,458 1,458 Derivative financial instruments — 5,403 — 5,403 Total assets $ 24,999 $ 570,996 $ 4,551 $ 600,546 Liabilities Derivative financial instruments $ — $ 5,403 $ — $ 5,403 Total liabilities $ — $ 5,403 $ — $ 5,403 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. U.S. Treasury Bills at March 31, 2017 were valued using Level 1 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 March 31, 2017 , Level 3 securities available for sale consist primarily of three Auction Rate Securities that are valued based on the securities' estimated cash flows, yields of comparable securities, and live trading levels. • State tax credits held for sale. At March 31, 2017 , of the $35.4 million of state tax credits held for sale on the condensed consolidated balance sheet, approximately $1.5 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. Given the significance of this input to the fair value calculation, 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 March 31, 2017 and 2016 . • Purchases, sales, issuances and settlements . There were no Level 3 purchases during the quarters ended March 31, 2017 or 2016 . • Transfers in and/or out of Level 3 . There were no Level 3 transfers during the quarters ended March 31, 2017 and 2016 . Securities available for sale, at fair value Three months ended March 31, (in thousands) 2017 2016 Beginning balance $ 3,089 $ 3,077 Total gains: Included in other comprehensive income 4 8 Purchases, sales, issuances and settlements: Purchases — — Ending balance $ 3,093 $ 3,085 Change in unrealized gains relating to assets still held at the reporting date $ 4 $ 8 State tax credits held for sale Three months ended March 31, (in thousands) 2017 2016 Beginning balance $ 3,585 $ 5,941 Total gains: Included in earnings 40 76 Purchases, sales, issuances and settlements: Sales (2,167 ) (1,284 ) Ending balance $ 1,458 $ 4,733 Change in unrealized gains (losses) relating to assets still held at the reporting date $ (606 ) $ (305 ) 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 March 31, 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 Impaired loans $ — $ — $ — $ — $ 157 Other real estate 177 — — 177 18 Total $ 177 $ — $ — $ 177 $ 175 (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. 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 March 31, 2017 and December 31, 2016 . March 31, 2017 December 31, 2016 (in thousands) Carrying Amount Estimated fair value Carrying Amount Estimated fair value Balance sheet assets Cash and due from banks $ 73,387 $ 73,387 $ 54,288 $ 54,288 Federal funds sold 1,112 1,112 446 446 Interest-bearing deposits 137,197 137,197 145,048 145,048 Securities available for sale 593,685 593,685 460,797 460,797 Securities held to maturity 79,236 78,617 80,463 79,639 Other investments, at cost 24,222 24,222 14,840 14,840 Loans held for sale 5,380 5,380 9,562 9,562 Derivative financial instruments 5,403 5,403 4,016 4,016 Loans, net 3,846,439 3,852,858 3,114,752 3,125,701 State tax credits, held for sale 35,431 37,041 38,071 41,264 Accrued interest receivable 12,229 12,229 11,117 11,117 Balance sheet liabilities Deposits 4,031,620 4,029,423 3,233,361 3,232,414 Subordinated debentures and notes 118,067 99,517 105,540 86,052 Federal Home Loan Bank advances 151,115 151,020 — — Other borrowings 235,052 234,964 276,980 276,905 Derivative financial instruments 5,403 5,403 4,016 4,016 Accrued interest payable 1,914 1,914 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 March 31, 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 $ — $ 78,617 $ — $ 78,617 Portfolio loans, net — — 3,852,858 3,852,858 State tax credits, held for sale — — — — Financial Liabilities: Deposits 3,425,513 — 603,910 4,029,423 Subordinated debentures and notes — 99,517 — 99,517 Federal Home Loan Bank advances — 151,020 — 151,020 Other borrowings — 234,964 — 234,964 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	3 Months Ended
	Mar. 31, 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") 2017-08 "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 is currently evaluating the new guidance and has not determined the impact this standard may have on its financial statements. FASB ASU 2014-09, "Revenue from Contracts with Customers" 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 is currently evaluating the new guidance and has not determined the impact this standard may have on its financial statements, nor decided upon the method of adoption. Entities have the option of using either a full retrospective or modified approach of adoption.

Summary of Significant Accoun20

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 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 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 $1.3 million for the three months ended March 31, 2017. Excess tax benefits related to stock compensation are presented as a cash inflow from operating activities for the three months ended March 31, 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 indentifiable 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.
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 March 31, 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)	3 Months Ended
	Mar. 31, 2017
Business Combinations [Abstract]
Business Acquisition, Pro Forma Information [Table Text Block]	The following table provides the unaudited pro forma information for the results of operations for the three months ended March 31, 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 March 31, 2017 are included in net income in the table below. Pro Forma Three months ended March 31, (in thousands, except per share data) 2017 2016 Total revenues (net interest income plus noninterest income) $ 49,598 $ 47,275 Net income 13,054 12,961 Diluted earnings per common share 0.55 0.55
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, except shares data) As Recorded by JCB Adjustments As Recorded by EFSC Assets acquired: Cash and cash equivalents $ 35,454 $ — $ 35,454 Securities 148,670 — 148,670 Portfolio loans, net 685,905 (10,619 ) (a) 675,286 Other real estate owned 6,762 (5,082 ) (b) 1,680 Other investments 2,695 — 2,695 Fixed assets, net 21,780 (2,259 ) (c) 19,521 Accrued interest receivable 2,794 — 2,794 Goodwill 7,806 (7,806 ) (d) — Other intangible assets 25 10,028 (e) 10,053 Deferred tax assets 4,634 7,086 (f) 11,720 Other assets 19,159 — 19,159 Total assets acquired $ 935,684 $ (8,652 ) $ 927,032 Liabilities assumed: Deposits $ 764,668 $ 629 (g) $ 765,297 Other borrowings 55,430 681 (h) 56,111 Trust preferred securities 12,887 (382 ) (i) 12,505 Accrued interest payable 653 — 653 Other liabilities 5,006 — 5,006 Total liabilities assumed $ 838,644 $ 928 $ 839,572 Net assets acquired $ 97,040 $ (9,580 ) $ 87,460 Consideration paid: Cash $ 29,283 Common stock 141,729 Total consideration paid $ 171,012 Goodwill $ 83,552 (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 $24.2 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. (d) Eliminate JCB’s recorded goodwill. (e) Recording of 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. (g) Fair value adjustment to time deposits based on current interest rates. (h) Fair value adjustment to the FHLB advances based on current interest rates. (i) Fair value adjustment based on the Company's evaluation of the trust preferred securities.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 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 March 31, (in thousands, except per share data) 2017 2016 Net income as reported $ 12,391 $ 11,025 Weighted average common shares outstanding 21,928 20,004 Additional dilutive common stock equivalents 381 229 Weighted average diluted common shares outstanding 22,309 20,233 Basic earnings per common share: $ 0.57 $ 0.55 Diluted earnings per common share: $ 0.56 $ 0.54

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 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: March 31, 2017 (in thousands) Amortized Cost Gross Gross Fair Value Available for sale securities: Obligations of U.S. Government-sponsored enterprises $ 104,979 $ 262 $ (66 ) $ 105,175 Obligations of states and political subdivisions 34,113 762 (365 ) 34,510 Agency mortgage-backed securities 431,030 1,508 (3,537 ) 429,001 U.S Treasury bills 24,998 1 — 24,999 Total securities available for sale $ 595,120 $ 2,533 $ (3,968 ) $ 593,685 Held to maturity securities: Obligations of states and political subdivisions $ 14,741 $ 33 $ (99 ) $ 14,675 Agency mortgage-backed securities 64,495 76 (629 ) 63,942 Total securities held to maturity $ 79,236 $ 109 $ (728 ) $ 78,617 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: March 31, 2017 (in thousands) Amortized Cost Gross Gross Fair Value Available for sale securities: Obligations of U.S. Government-sponsored enterprises $ 104,979 $ 262 $ (66 ) $ 105,175 Obligations of states and political subdivisions 34,113 762 (365 ) 34,510 Agency mortgage-backed securities 431,030 1,508 (3,537 ) 429,001 U.S Treasury bills 24,998 1 — 24,999 Total securities available for sale $ 595,120 $ 2,533 $ (3,968 ) $ 593,685 Held to maturity securities: Obligations of states and political subdivisions $ 14,741 $ 33 $ (99 ) $ 14,675 Agency mortgage-backed securities 64,495 76 (629 ) 63,942 Total securities held to maturity $ 79,236 $ 109 $ (728 ) $ 78,617 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 March 31, 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 5 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 $ 27,529 $ 27,563 $ 657 $ 656 Due after one year through five years 94,131 94,743 7,056 7,043 Due after five years through ten years 14,532 14,759 6,523 6,479 Due after ten years 2,900 2,620 505 497 Agency mortgage-backed securities 431,030 429,001 64,495 63,942 U.S Treasury bills 24,998 24,999 — — $ 595,120 $ 593,685 $ 79,236 $ 78,617
Schedule of Unrealized Loss on Investments	The following table represents a summary of investment securities that had an unrealized loss: March 31, 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 $ 20,110 $ 66 $ — $ — $ 20,110 $ 66 Obligations of states and political subdivisions $ 14,371 $ 152 $ 3,559 $ 312 $ 17,930 $ 464 Agency mortgage-backed securities 298,238 3,686 13,311 480 311,549 4,166 $ 332,719 $ 3,904 $ 16,870 $ 792 $ 349,589 $ 4,696 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
Schedule of Realized Gain (Loss)

Loans (Tables)

Loans (Tables) - Portfolio loans, net	3 Months Ended
	Mar. 31, 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. March 31, 2017 December 31, 2016 Loans not accounted for as ASC 310-30 $ 3,802,681 $ 3,118,392 Loans accounted for as ASC 310-30 88,383 39,769 Total loans $ 3,891,064 $ 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 March 31, 2017 and December 31, 2016 : (in thousands) March 31, 2017 December 31, 2016 Commercial and industrial $ 1,773,105 $ 1,632,714 Real estate: Commercial - investor owned 726,413 544,808 Commercial - owner occupied 480,281 350,148 Construction and land development 288,342 194,542 Residential 356,415 240,760 Total real estate loans 1,851,451 1,330,258 Consumer and other 179,100 156,182 Loans, before unearned loan fees 3,803,656 3,119,154 Unearned loan fees, net (975 ) (762 ) Loans, including unearned loan fees $ 3,802,681 $ 3,118,392
Summary of Allowance for Loan Losses and the Recorded Investment in Portfolio Loans by Class and Category Based on Impairment Method	(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 (in thousands) Commercial and industrial CRE - investor owned CRE - owner occupied Construction and land development Residential real estate Consumer and other Total Balance March 31, 2017 Allowance for loan losses - Ending balance: Individually evaluated for impairment $ 5,047 $ — $ — $ 140 $ — $ — $ 5,187 Collectively evaluated for impairment 23,731 3,324 2,730 1,162 2,036 978 33,961 Total $ 28,778 $ 3,324 $ 2,730 $ 1,302 $ 2,036 $ 978 $ 39,148 Loans - Ending balance: Individually evaluated for impairment $ 12,152 $ 281 $ 1,591 $ 1,575 $ 61 $ — $ 15,660 Collectively evaluated for impairment 1,760,953 726,132 478,690 286,767 356,354 178,125 3,787,021 Total $ 1,773,105 $ 726,413 $ 480,281 $ 288,342 $ 356,415 $ 178,125 $ 3,802,681 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	March 31, 2017 (in thousands) Unpaid Recorded Recorded Allowance Total Related Allowance Average Commercial and industrial $ 11,930 $ 40 $ 11,963 $ 12,003 $ 5,047 $ 12,017 Real estate: Commercial - investor owned 281 282 — 282 — 272 Commercial - owner occupied — — — — — — Construction and land development 1,575 1,658 341 1,999 140 1,813 Residential 62 62 — 62 — 62 Consumer and other — — — — — — Total $ 13,848 $ 2,042 $ 12,304 $ 14,346 $ 5,187 $ 14,164 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 The following table presents details for past due and impaired loans: Three months ended March 31, (in thousands) 2017 2016 Total interest income that would have been recognized under original terms $ 315 $ 148 Total cash received and recognized as interest income on non-accrual loans 23 6 Total interest income recognized on impaired loans 33 6 March 31, 2017 (in thousands) Non-accrual Restructured Loans over 90 days past due and still accruing interest Total Commercial and industrial $ 9,692 $ 2,311 $ — $ 12,003 Real estate: Commercial - investor owned 282 — — 282 Commercial - owner occupied — — — — Construction and land development 1,979 20 — 1,999 Residential 62 — — 62 Consumer and other — — — — Total $ 12,015 $ 2,331 $ — $ 14,346 December 31, 2016 (in thousands) Non-accrual Restructured Loans over 90 days past due and still accruing interest 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 for Portfolio Loans Restructured	There were no restructured loans during the three months ended March 31, 2017 and 2016 .
Summary of Recorded Investment by Category for Portfolio Loans Restructured and Subsequently Defaulted	As of March 31, 2017 , the Company had $0.7 million specific reserves allocated to loans that have been restructured. There were no loans restructured that subsequently defaulted during the three months ended March 31, 2017 or 2016 .
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 March 31, 2017 and December 31, 2016 is shown below. March 31, 2017 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ 10,624 $ — $ 10,624 $ 1,762,481 $ 1,773,105 Real estate: Commercial - investor owned 708 — 708 725,705 726,413 Commercial - owner occupied 529 — 529 479,752 480,281 Construction and land development — 1,214 1,214 287,128 288,342 Residential 285 — 285 356,130 356,415 Consumer and other 2 — 2 178,123 178,125 Total $ 12,148 $ 1,214 $ 13,362 $ 3,789,319 $ 3,802,681 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 March 31, 2017 , which is based upon the most recent analysis performed, and December 31, 2016 is as follows: March 31, 2017 (in thousands) Pass (1-6) Watch (7) Substandard (8) Doubtful (9) Total Commercial and industrial $ 1,629,105 $ 75,946 $ 68,054 $ — $ 1,773,105 Real estate: Commercial - investor owned 706,958 15,777 3,678 — 726,413 Commercial - owner occupied 440,319 35,505 4,457 — 480,281 Construction and land development 283,410 2,841 2,091 — 288,342 Residential 347,118 5,051 4,246 — 356,415 Consumer and other 176,340 375 1,410 — 178,125 Total $ 3,583,250 $ 135,495 $ 83,936 $ — $ 3,802,681 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)	3 Months Ended
	Mar. 31, 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 three months ended March 31, 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 70,435 11,669 8,550 50,216 Principal reductions and interest payments (4,310 ) — — (4,310 ) Accretion of loan discount — — (1,389 ) 1,389 Changes in contractual and expected cash flows due to remeasurement 3,166 (307 ) 1,165 2,308 Reductions due to disposals (1,341 ) (345 ) (264 ) (732 ) Balance March 31, 2017 $ 133,953 $ 29,919 $ 21,238 $ 82,796 Balance December 31, 2015 $ 116,689 $ 26,765 $ 25,341 $ 64,583 Principal reductions and interest payments (5,965 ) — — (5,965 ) Accretion of loan discount — — (1,845 ) 1,845 Changes in contractual and expected cash flows due to remeasurement 4,012 2,375 (1,032 ) 2,669 Reductions due to disposals (12,869 ) (2,127 ) (1,518 ) (9,224 ) Balance March 31, 2016 $ 101,867 $ 27,013 $ 20,946 $ 53,908
Covered Loans
Covered Loans [Line Items]
Summary of PCI Loans by Category	Below is a summary of PCI loans by category at March 31, 2017 and December 31, 2016 : March 31, 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 5.84 $ 4,335 5.87 $ 3,523 Real estate: Commercial - investor owned 7.00 42,532 6.95 8,162 Commercial - owner occupied 6.47 13,580 6.39 11,863 Construction and land development 6.18 12,914 5.80 4,365 Residential 6.06 14,943 5.64 11,792 Total real estate loans 83,969 36,182 Consumer and other 3.50 79 1.64 64 Purchased credit impaired loans $ 88,383 $ 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 March 31, 2017 and December 31, 2016 is shown below: March 31, 2017 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ — $ 21 $ 21 $ 4,314 $ 4,335 Real estate: Commercial - investor owned — — — 42,532 42,532 Commercial - owner occupied — — — 13,580 13,580 Construction and land development — — — 12,914 12,914 Residential 403 29 432 14,511 14,943 Consumer and other — — — 79 79 Total $ 403 $ 50 $ 453 $ 87,930 $ 88,383 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	.

Derivative Financial Instrume26

Derivative Financial Instruments (Tables) - Client-Related	3 Months Ended
	Mar. 31, 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) March 31, December 31, March 31, December 31, March 31, December 31, Non-designated hedging instruments Interest rate swap contracts $ 153,069 $ 124,322 $ 1,449 $ 982 $ 1,449 $ 982 Foreign exchange forward contracts 3,954 3,034 3,954 3,034 3,954 3,034
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	For the three months ended March 31, 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.

Commitments (Tables)

Commitments (Tables)	3 Months Ended
	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Commitments	The contractual amounts of off-balance-sheet financial instruments as of March 31, 2017 , and December 31, 2016 , are as follows: (in thousands) March 31, 2017 December 31, 2016 Commitments to extend credit $ 1,193,968 $ 1,075,170 Letters of credit 79,719 78,954

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2017 and December 31, 2016 , segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: March 31, 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 $ — $ 105,175 $ — $ 105,175 Obligations of states and political subdivisions — 31,417 3,093 34,510 Residential mortgage-backed securities — 429,001 — 429,001 U.S. Treasury Bills 24,999 — — 24,999 Total securities available for sale $ 24,999 $ 565,593 $ 3,093 $ 593,685 State tax credits held for sale — — 1,458 1,458 Derivative financial instruments — 5,403 — 5,403 Total assets $ 24,999 $ 570,996 $ 4,551 $ 600,546 Liabilities Derivative financial instruments $ — $ 5,403 $ — $ 5,403 Total liabilities $ — $ 5,403 $ — $ 5,403 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 March 31, 2017 and 2016 . • Purchases, sales, issuances and settlements . There were no Level 3 purchases during the quarters ended March 31, 2017 or 2016 . • Transfers in and/or out of Level 3 . There were no Level 3 transfers during the quarters ended March 31, 2017 and 2016 . Securities available for sale, at fair value Three months ended March 31, (in thousands) 2017 2016 Beginning balance $ 3,089 $ 3,077 Total gains: Included in other comprehensive income 4 8 Purchases, sales, issuances and settlements: Purchases — — Ending balance $ 3,093 $ 3,085 Change in unrealized gains relating to assets still held at the reporting date $ 4 $ 8 State tax credits held for sale Three months ended March 31, (in thousands) 2017 2016 Beginning balance $ 3,585 $ 5,941 Total gains: Included in earnings 40 76 Purchases, sales, issuances and settlements: Sales (2,167 ) (1,284 ) Ending balance $ 1,458 $ 4,733 Change in unrealized gains (losses) relating to assets still held at the reporting date $ (606 ) $ (305 )
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 March 31, 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 Impaired loans $ — $ — $ — $ — $ 157 Other real estate 177 — — 177 18 Total $ 177 $ — $ — $ 177 $ 175 (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 March 31, 2017 and December 31, 2016 . March 31, 2017 December 31, 2016 (in thousands) Carrying Amount Estimated fair value Carrying Amount Estimated fair value Balance sheet assets Cash and due from banks $ 73,387 $ 73,387 $ 54,288 $ 54,288 Federal funds sold 1,112 1,112 446 446 Interest-bearing deposits 137,197 137,197 145,048 145,048 Securities available for sale 593,685 593,685 460,797 460,797 Securities held to maturity 79,236 78,617 80,463 79,639 Other investments, at cost 24,222 24,222 14,840 14,840 Loans held for sale 5,380 5,380 9,562 9,562 Derivative financial instruments 5,403 5,403 4,016 4,016 Loans, net 3,846,439 3,852,858 3,114,752 3,125,701 State tax credits, held for sale 35,431 37,041 38,071 41,264 Accrued interest receivable 12,229 12,229 11,117 11,117 Balance sheet liabilities Deposits 4,031,620 4,029,423 3,233,361 3,232,414 Subordinated debentures and notes 118,067 99,517 105,540 86,052 Federal Home Loan Bank advances 151,115 151,020 — — Other borrowings 235,052 234,964 276,980 276,905 Derivative financial instruments 5,403 5,403 4,016 4,016 Accrued interest payable 1,914 1,914 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 March 31, 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 $ — $ 78,617 $ — $ 78,617 Portfolio loans, net — — 3,852,858 3,852,858 State tax credits, held for sale — — — — Financial Liabilities: Deposits 3,425,513 — 603,910 4,029,423 Subordinated debentures and notes — 99,517 — 99,517 Federal Home Loan Bank advances — 151,020 — 151,020 Other borrowings — 234,964 — 234,964 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) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Property, Plant and Equipment [Line Items]
Reclassification for the adoption of ASU 2016-09	$ 5.2
Decrease in Income Taxes	$ 1.3

Acquisitions & Divestitures - N

Acquisitions & Divestitures - Narrative (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Feb. 10, 2017USD ($)
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			85.39
Business Acquisition, Goodwill, Expected Tax Deductible Amount			$ 83,600,000
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	$ 1,700,000	$ 1,400,000
Fair Value Discount Recorded to Portfolio Loans	$ 24,200,000

Acquisitions & Divestitures - S

Acquisitions & Divestitures - Summary of Balance Sheet Amounts Relative to Branches Sold (Details)	3 Months Ended
	Mar. 31, 2017USD ($)$ / shares	Mar. 31, 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	$ 12,391,000	$ 11,025,000
Cash and cash equivalents	209,001,000			$ 198,802,000
Property, Plant and Equipment, Net	34,291,000			14,910,000
Interest Receivable	12,229,000			11,117,000
Goodwill	113,886,000			30,334,000
Other Intangible Assets	11,758,000			2,151,000
Deposits	4,031,620,000			3,233,361,000
Other Borrowings	235,052,000			276,980,000
Interest Payable	1,914,000			1,105,000
Other Liabilities	$ 30,537,000			$ 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
Transaction value including JCB's common stock and stock options			171,000,000
Business Acquisition, Goodwill, Expected Tax Deductible Amount			83,600,000
Pro Forma [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues	$ 49,598,000	47,275,000
Net income as reported	$ 13,054,000	$ 12,961,000
Diluted Earnings Per Share Pro Forma | $ / shares	$ 0.55	$ 0.55
As Recorded by JCB [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents			35,454,000
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			19,159,000
Total assets acquired			935,684,000
Deposits			764,668,000
Other Borrowings			55,430,000
Trust preferred securities			12,887,000
Interest Payable			653,000
Other Liabilities			5,006,000
Total Liabilities Assumed			838,644,000
Net assets acquired			97,040,000
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
Securities			0
Portfolio loans, net			(10,619,000)
Other real estate owned			(5,082,000)
Other Investments			0
Property, Plant and Equipment, Net			(2,259,000)
Interest Receivable			0
Goodwill			(7,806,000)
Other Intangible Assets			10,028,000
Deferred Tax Assets			7,086,000
Other Assets			0
Total assets acquired			(8,652,000)
Deposits			629,000
Other Borrowings			681,000
Trust preferred securities			(382,000)
Interest Payable			0
Other Liabilities			0
Total Liabilities Assumed			928,000
Net assets acquired			(9,580,000)
As Recorded by EFSC [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents			35,454,000
Securities			148,670,000
Portfolio loans, net			675,286,000
Other real estate owned			1,680,000
Other Investments			2,695,000
Property, Plant and Equipment, Net			19,521,000
Interest Receivable			2,794,000
Goodwill			0
Other Intangible Assets			10,053,000
Deferred Tax Assets			11,720,000
Other Assets			19,159,000
Total assets acquired			927,032,000
Deposits			765,297,000
Other Borrowings			56,111,000
Trust preferred securities			12,505,000
Interest Payable			653,000
Other Liabilities			5,006,000
Total Liabilities Assumed			839,572,000
Net assets acquired			87,460,000
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			$ 83,552,000

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share
Net income as reported	$ 12,391	$ 11,025
Impact of assumed conversions
Weighted average common shares outstanding (in shares)	21,928,000	20,004,000
Additional dilutive common stock equivalents (in shares)	381,000	229,000
Weighted average diluted common shares outstanding (in shares)	22,309,000	20,233,000
Basic earnings per common share (in dollars per share)	$ 0.57	$ 0.55
Diluted earnings per common share (in dollars per share)	$ 0.56	$ 0.54
Common stock equivalents excluded from earnings per share calculations due to anti-dilutive effect (in shares)	2,900	88,040
Convertible Debt Securities
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Convertible trust preferred securities, interest rate, stated percentage	9.00%	9.00%

Investments - Schedule of Avail

Investments - Schedule of Available-for-sale and Held-to-Maturity Securities Reconciliation (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 79,236	$ 80,463
Gross Unrealized Gains	109	56
Gross Unrealized Losses	(728)	(880)
Fair Value	78,617	79,639
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	595,120	463,143
Gross Unrealized Gains	2,533	2,079
Gross Unrealized Losses	(3,968)	(4,425)
Fair Value	593,685	460,797
Obligations of U.S. Government-sponsored enterprises
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	104,979	107,312
Gross Unrealized Gains	262	348
Gross Unrealized Losses	(66)	0
Fair Value	105,175	107,660
Obligations of states and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	34,113	36,486
Gross Unrealized Gains	762	630
Gross Unrealized Losses	(365)	(485)
Fair Value	34,510	36,631
Agency mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	431,030	319,345
Gross Unrealized Gains	1,508	1,101
Gross Unrealized Losses	(3,537)	(3,940)
Fair Value	429,001	316,506
US Treasury Bill Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	24,998
Gross Unrealized Gains	1
Gross Unrealized Losses	0
Fair Value	24,999
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	14,741	14,759
Gross Unrealized Gains	33	11
Gross Unrealized Losses	(99)	(242)
Fair Value	14,675	14,528
Agency mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	64,495	65,704
Gross Unrealized Gains	76	45
Gross Unrealized Losses	(629)	(638)
Fair Value	$ 63,942	$ 65,111

Investments - Investments Class

Investments - Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Available for sale, Amortized Cost
Due in one year or less	$ 27,529
Due after one year through five years	94,131
Due after five years through ten years	14,532
Due after ten years	2,900
Agency mortgage-backed securities	431,030
Available-for-sale Securities, Amortized Cost Basis	24,998
Amortized Cost	595,120	$ 463,143
Available for sale, Estimated Fair Value
Due in one year or less	27,563
Due after one year through five years	94,743
Due after five years through ten years	14,759
Due after ten years	2,620
Agency mortgage-backed securities	429,001
Available-for-sale, US Treasury Bills, Fair Value	24,999
Available for sale, fair value	593,685	460,797
Held to maturity, Amortized Cost
Due in one year or less	657
Due after one year through five years	7,056
Due after five years through ten years	6,523
Due after ten years	505
Agency mortgage-backed securities	64,495
Held-to-maturity, US Treasury Bills, Amortized Cost	0
Amortized Cost	79,236	80,463
Held to maturity, Estimated Fair Value
Due in one year or less	656
Due after one year through five years	7,043
Due after five years through ten years	6,479
Due after ten years	497
Agency mortgage-backed securities	63,942
Held-to-maturity, US Treasury Bills, Fair Value	0
Held to maturity, fair value	$ 78,617	$ 79,639

Investments - Schedule of Unrea

Investments - Schedule of Unrealized Loss on Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 332,719	$ 289,095
Less than 12 months, unrealized losses	3,904	4,492
12 months or more, fair value	16,870	16,436
12 months or more, unrealized losses	792	813
Total, fair value	349,589	305,531
Total, unrealized losses	4,696	5,305
Obligations of U.S. Government-sponsored enterprises
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	20,110
Less than 12 months, unrealized losses	66
12 months or more, fair value	0
12 months or more, unrealized losses	0
Total, fair value	20,110
Total, unrealized losses	66
Obligations of states and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	14,371	21,361
Less than 12 months, unrealized losses	152	408
12 months or more, fair value	3,559	3,553
12 months or more, unrealized losses	312	320
Total, fair value	17,930	24,914
Total, unrealized losses	464	728
Agency mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	298,238	267,734
Less than 12 months, unrealized losses	3,686	4,084
12 months or more, fair value	13,311	12,883
12 months or more, unrealized losses	480	493
Total, fair value	311,549	280,617
Total, unrealized losses	$ 4,166	$ 4,577

Investments - Narrative (Detail

Investments - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Other investments, at cost	$ 24,222	$ 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	$ 466,100	$ 407,300
Mortgage-backed securities, weighted average life	5 years

Loans - Summary of Portfolio Lo

Loans - Summary of Portfolio Loans by Category (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans, including unearned loan fees	$ 3,891,064	$ 3,158,161
Portfolio loans, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	3,803,656	3,119,154
Unearned loan fees, net	(975)	(762)
Portfolio loans, including unearned loan fees	3,802,681	3,118,392
Portfolio loans, net | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	1,773,105	1,632,714
Portfolio loans, net | Commercial - investor owned
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	726,413	544,808
Portfolio loans, net | Commercial - owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	480,281	350,148
Portfolio loans, net | Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	288,342	194,542
Portfolio loans, net | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	356,415	240,760
Portfolio loans, net | Total real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	1,851,451	1,330,258
Portfolio loans, net | Consumer and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	179,100	156,182
Portfolio loans, including unearned loan fees	178,125	155,420
Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	88,383	39,769
Portfolio loans	88,383	39,769
Covered Loans [Member] | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	4,335	3,523
Portfolio loans	4,335	3,523
Covered Loans [Member] | Commercial - investor owned
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	42,532	8,162
Portfolio loans	42,532	8,162
Covered Loans [Member] | Commercial - owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	13,580	11,863
Portfolio loans	13,580	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	12,914	4,365
Portfolio loans	12,914	4,365
Covered Loans [Member] | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	14,943	11,792
Portfolio loans	14,943	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	83,969	36,182
Covered Loans [Member] | Consumer and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	79	64
Portfolio loans	$ 79	$ 64

Loans - Summary of Allowance fo

Loans - Summary of Allowance for Loan Losses by Portfolio Class and Category (Details) - Portfolio loans, net $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2015	$ 37,565
Provision (provision reversal) charged to expense	1,533
Losses charged off	(171)
Recoveries	221
Balance at March 31, 2016	39,148
Commercial and industrial
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2015	26,996
Provision (provision reversal) charged to expense	1,835
Losses charged off	(133)
Recoveries	80
Balance at March 31, 2016	28,778
CRE - owner occupied
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2015	2,890
Provision (provision reversal) charged to expense	(249)
Losses charged off	0
Recoveries	89
Balance at March 31, 2016	2,730
Commercial Real Estate Investor Owned
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2015	3,420
Provision (provision reversal) charged to expense	(105)
Losses charged off	0
Recoveries	9
Balance at March 31, 2016	3,324
Construction and land development
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2015	1,304
Provision (provision reversal) charged to expense	(11)
Losses charged off	0
Recoveries	9
Balance at March 31, 2016	1,302
Residential real estate
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2015	2,023
Provision (provision reversal) charged to expense	(3)
Losses charged off	(9)
Recoveries	25
Balance at March 31, 2016	2,036
Consumer and other
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2015	932
Provision (provision reversal) charged to expense	66
Losses charged off	(29)
Recoveries	9
Balance at March 31, 2016	$ 978

Loans - Summary of Recorded Inv

Loans - Summary of Recorded Investment in Portfolio Loans by Class and Category Based on Impairment Method (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Loans - Ending balance:
Loans and Leases Receivable, Gross	$ 3,891,064	$ 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]
Individually evaluated for impairment	5,187	3,064
Collectively evaluated for impairment	33,961	34,501
Total	39,148	37,565
Loans - Ending balance:
Individually evaluated for impairment	15,660	16,772
Collectively evaluated for impairment	3,787,021	3,101,620
Total	3,803,656	3,119,154
Loans and Leases Receivable, Gross	3,802,681	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]
Individually evaluated for impairment	5,047	2,909
Collectively evaluated for impairment	23,731	24,087
Total	28,778	26,996
Loans - Ending balance:
Individually evaluated for impairment	12,152	12,523
Collectively evaluated for impairment	1,760,953	1,620,191
Total	1,773,105	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]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	3,324	3,420
Total	3,324	3,420
Loans - Ending balance:
Individually evaluated for impairment	281	430
Collectively evaluated for impairment	726,132	544,378
Total	726,413	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]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	2,730	2,890
Total	2,730	2,890
Loans - Ending balance:
Individually evaluated for impairment	1,591	1,854
Collectively evaluated for impairment	478,690	348,294
Total	480,281	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]
Individually evaluated for impairment	140	155
Collectively evaluated for impairment	1,162	1,149
Total	1,302	1,304
Loans - Ending balance:
Individually evaluated for impairment	1,575	1,903
Collectively evaluated for impairment	286,767	192,639
Total	288,342	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	0	0
Collectively evaluated for impairment	2,036	2,023
Total	2,036	2,023
Loans - Ending balance:
Individually evaluated for impairment	61	62
Collectively evaluated for impairment	356,354	240,698
Total	356,415	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]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	978	932
Total	978	932
Loans - Ending balance:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	178,125	155,420
Total	179,100	156,182
Loans and Leases Receivable, Gross	$ 178,125	$ 155,420

Loans - Summary of Portfolio 40

Loans - Summary of Portfolio Loans Individually Evaluated for Impairment by Category (Details) - Portfolio loans, net - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	$ 13,848	$ 15,057
Recorded Investment With No Allowance	2,042	3,241
Recorded Investment With Allowance	12,304	12,150
Total Recorded Investment	14,346	15,391
Related Allowance	5,187	3,064
Average Recorded Investment	14,164	7,366
Commercial and industrial
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	11,930	12,341
Recorded Investment With No Allowance	40	566
Recorded Investment With Allowance	11,963	11,791
Total Recorded Investment	12,003	12,357
Related Allowance	5,047	2,909
Average Recorded Investment	12,017	4,489
Commercial - owner occupied
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	0	225
Recorded Investment With No Allowance	0	231
Recorded Investment With Allowance	0	0
Total Recorded Investment	0	231
Related Allowance	0	0
Average Recorded Investment	0	227
Commercial - investor owned
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	281	525
Recorded Investment With No Allowance	282	435
Recorded Investment With Allowance	0	0
Total Recorded Investment	282	435
Related Allowance	0	0
Average Recorded Investment	272	668
Construction and land development
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	1,575	1,904
Recorded Investment With No Allowance	1,658	1,947
Recorded Investment With Allowance	341	359
Total Recorded Investment	1,999	2,306
Related Allowance	140	155
Average Recorded Investment	1,813	1,918
Residential real estate
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	62	62
Recorded Investment With No Allowance	62	62
Recorded Investment With Allowance	0	0
Total Recorded Investment	62	62
Related Allowance	0	0
Average Recorded Investment	62	64
Consumer and other
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	0	0
Recorded Investment With No Allowance	0	0
Recorded Investment With Allowance	0	0
Total Recorded Investment	0	0
Related Allowance	0	0
Average Recorded Investment	$ 0	$ 0

Loans - Summary of Past Due and

Loans - Summary of Past Due and Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Receivables [Abstract]
Total interest income that would have been recognized under original terms	$ 315	$ 148
Total cash received and recognized as interest income on non-accrual loans	23	6
Total interest income recognized on impaired loans	$ 33	$ 6

Loans - Narrative (Details)

Loans - Narrative (Details)	3 Months Ended
	Mar. 31, 2017USD ($)loan	Mar. 31, 2016loan	Dec. 31, 2017loan	Dec. 31, 2016USD ($)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	$ 733,899
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loan	0	0
Unadvanced Commitment on Impaired Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Estimated losses attributable to unadvanced commitments on impaired loans	$ 300,000			300,000
Non-Covered Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Modifications, Number of Contracts | loan	0
Financing Receivable, Gross	$ 3,803,656,000			3,119,154,000
Non-Covered Loans | Consumer and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	$ 179,100,000			$ 156,182,000

Loans - Summary of Recorded I43

Loans - Summary of Recorded Investment in Impaired Portfolio Loans by Category (Details) - Non-Covered Loans	3 Months Ended
	Mar. 31, 2017USD ($)loan	Dec. 31, 2016USD ($)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Modifications, Number of Contracts | loan	0
Non-accrual	$ 12,015,000	$ 13,060,000
Restructured	2,331,000	2,331,000
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0
Total Recorded Investment	14,346,000	15,391,000
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	9,692,000	10,046,000
Restructured	2,311,000	2,311,000
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0
Total Recorded Investment	12,003,000	12,357,000
Commercial - investor owned
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	282,000	435,000
Restructured	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0
Total Recorded Investment	282,000	435,000
Commercial - owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	231,000
Restructured	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0
Total Recorded Investment	0	231,000
Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	1,979,000	2,286,000
Restructured	20,000	20,000
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0
Total Recorded Investment	1,999,000	2,306,000
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	62,000	62,000
Restructured	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0
Total Recorded Investment	62,000	62,000
Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	0
Restructured	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0
Total Recorded Investment	$ 0	$ 0

Loans - Summary of Recorded I44

Loans - Summary of Recorded Investment by Category for Portfolio Loans Restructured (Details)	3 Months Ended
	Mar. 31, 2017loan
Non-Covered Loans
Financing Receivable, Modifications [Line Items]
Number of Loans	0

Loans - Summary of Recorded I45

Loans - Summary of Recorded Investment by Category for Portfolio Loans Restructured and Subsequently Defaulted (Details)	3 Months Ended
	Mar. 31, 2017loan
Non-Covered Loans
Schedule of Financing Receivables, Troubled Debt Restructurings - Suibsequent Defaults [Line Items]
Financing Receivable, Modifications, Number of Contracts	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	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	$ 3,891,064	$ 3,158,161
Non-Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	12,148	999
90 or More Days Past Due	1,214	2,099
Total Past Due	13,362	3,098
Current	3,789,319	3,115,294
Loans and Leases Receivable, Gross	3,802,681	3,118,392
Total	3,803,656	3,119,154
Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	10,624	334
90 or More Days Past Due	0	171
Total Past Due	10,624	505
Current	1,762,481	1,632,209
Total	1,773,105	1,632,714
Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	529	212
90 or More Days Past Due	0	225
Total Past Due	529	437
Current	479,752	349,711
Total	480,281	350,148
Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	708	0
90 or More Days Past Due	0	175
Total Past Due	708	175
Current	725,705	544,633
Total	726,413	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	1,214	1,528
Total Past Due	1,214	1,883
Current	287,128	192,659
Total	288,342	194,542
Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	285	91
90 or More Days Past Due	0	0
Total Past Due	285	91
Current	356,130	240,669
Total	356,415	240,760
Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	2	7
90 or More Days Past Due	0	0
Total Past Due	2	7
Current	178,123	155,413
Loans and Leases Receivable, Gross	178,125	155,420
Total	$ 179,100	$ 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	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	$ 3,891,064	$ 3,158,161
Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	3,803,656	3,119,154
Loans and Leases Receivable, Gross	3,802,681	3,118,392
Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	1,773,105	1,632,714
Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	480,281	350,148
Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	726,413	544,808
Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	288,342	194,542
Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	356,415	240,760
Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	179,100	156,182
Loans and Leases Receivable, Gross	178,125	155,420
Pass (1-6) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	3,583,250	2,909,234
Pass (1-6) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	1,629,105	1,499,114
Pass (1-6) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	440,319	306,658
Pass (1-6) | Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	706,958	530,494
Pass (1-6) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	283,410	185,505
Pass (1-6) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	347,118	233,479
Pass (1-6) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	176,340	153,984
Watch (7) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	135,495	116,686
Watch (7) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	75,946	57,416
Watch (7) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	35,505	39,249
Watch (7) | Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	15,777	10,449
Watch (7) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	2,841	6,575
Watch (7) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	5,051	2,997
Watch (7) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	375	0
Substandard (8) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	83,936	92,472
Substandard (8) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	68,054	76,184
Substandard (8) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	4,457	4,241
Substandard (8) | Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	3,678	3,865
Substandard (8) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	2,091	2,462
Substandard (8) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	4,246	4,284
Substandard (8) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	1,410	1,436
Doubtful (9) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	0	0
Doubtful (9) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	0	0
Doubtful (9) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	0	0
Doubtful (9) | Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	0	0
Doubtful (9) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	0	0
Doubtful (9) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	0	0
Doubtful (9) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	$ 0	$ 0

Purchased Credit Impaired ("P48

Purchased Credit Impaired ("PCI") Loans - Summary of PCI Loans by Category (Details) - Covered Loans $ in Thousands	Mar. 31, 2017USD ($)rating	Dec. 31, 2016USD ($)rating
Covered Loans [Line Items]
Recorded Investment PCI Loans	$ 88,383	$ 39,769
Construction and land development
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	6.18	5.80
Recorded Investment PCI Loans	$ 12,914	$ 4,365
Commercial Real Estate Investor Owned
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	7	6.95
Recorded Investment PCI Loans	$ 42,532	$ 8,162
CRE - owner occupied
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	6.47	6.39
Recorded Investment PCI Loans	$ 13,580	$ 11,863
Residential real estate
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	6.06	5.64
Recorded Investment PCI Loans	$ 14,943	$ 11,792
Total real estate loans
Covered Loans [Line Items]
Recorded Investment PCI Loans	$ 83,969	$ 36,182
Commercial and industrial
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	5.84	5.87
Recorded Investment PCI Loans	$ 4,335	$ 3,523
Consumer and other
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	3.50	1.64
Recorded Investment PCI Loans	$ 79	$ 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	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	$ 403	$ 169
90 or More Days Past Due	50	51
Total Past Due	453	220
Current	87,930	39,549
Total	88,383	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	21	0
Total Past Due	21	0
Current	4,314	3,523
Total	4,335	3,523
CRE - owner occupied
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	13,580	11,863
Total	13,580	11,863
Commercial Real Estate Investor Owned
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	42,532	8,162
Total	42,532	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	0	0
Total Past Due	0	0
Current	12,914	4,365
Total	12,914	4,365
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	403	169
90 or More Days Past Due	29	51
Total Past Due	432	220
Current	14,511	11,572
Total	14,943	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	79	64
Total	$ 79	$ 64

Purchased Credit Impaired ("P50

Purchased Credit Impaired ("PCI") Loans - Rollforward of PCI Loans, Net of Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 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	50,216
Principal reductions and interest payments	(4,310)	(5,965)
Accretion of loan discount	1,389	1,845
Changes in contractual and expected cash flows due to remeasurement	(2,308)	(2,669)
Reductions due to disposals	(732)	(9,224)
Balance at end of period	82,796	53,908
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	70,435
Principal reductions and interest payments	(4,310)	(5,965)
Accretion of loan discount	0	0
Changes in contractual and expected cash flows due to remeasurement	(3,166)	4,012
Reductions due to disposals	(1,341)	(12,869)
Balance at end of period	133,953	101,867
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	11,669
Principal reductions and interest payments	0	0
Accretion of loan discount	0	0
Changes in contractual and expected cash flows due to remeasurement	307	2,375
Reductions due to disposals	(345)	(2,127)
Balance at end of period	29,919	27,013
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	8,550
Principal reductions and interest payments	0	0
Accretion of loan discount	1,389	1,845
Changes in contractual and expected cash flows due to remeasurement	1,165	1,032
Reductions due to disposals	(264)	(1,518)
Balance at end of period	$ 21,238	$ 20,946

Purchased Credit Impaired ("P51

Purchased Credit Impaired ("PCI") Loans - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Receivables [Abstract]
PCI loans outstanding	$ 119.1	$ 54.6

Derivative Financial Instrume52

Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 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	153,069	124,322
Non-designated hedging instruments | Client-Related | Foreign Exchange Forward [Member]
Summary of Derivative Instruments [Abstract]
Notional Amount	3,954	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	1,449	982
Non-designated hedging instruments | Client-Related | Other Assets | Foreign Exchange Forward [Member]
Summary of Derivative Instruments [Abstract]
Asset derivatives (other assets), fair value	3,954	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	1,449	982
Non-designated hedging instruments | Client-Related | Other Liabilities | Foreign Exchange Forward [Member]
Summary of Derivative Instruments [Abstract]
Liability derivatives (other liabilities), fair value	$ 3,954	$ 3,034

Commitments (Details)

Commitments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 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	$ 1,193,968	1,075,170
Standby letters of credit
Schedule of Commitments [Line Items]
Off-balance sheet financial instruments, contractual amounts	$ 79,719	78,954
Standby letters of credit | Maximum
Schedule of Commitments [Line Items]
Remaining term	5 years
Standby 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	$ 300	300
Fixed Rate Loan Commitment | Commitments to extend credit
Schedule of Commitments [Line Items]
Off-balance sheet financial instruments, contractual amounts	$ 114,900	$ 89,700

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Assets
Securities available for sale	$ 593,685	$ 460,797
State tax credits held for sale	1,458	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	593,685	460,797
State tax credits held for sale	37,041	41,264
Derivative financial instruments	5,403	4,016
Liabilities
Derivative financial instruments	5,403	4,016
Obligations of U.S. Government-sponsored enterprises
Assets
Securities available for sale	105,175	107,660
Obligations of states and political subdivisions
Assets
Securities available for sale	34,510	36,631
Residential mortgage-backed securities
Assets
Securities available for sale	429,001	316,506
US Treasury Bill Securities [Member]
Assets
Securities available for sale	24,999
Recurring basis | Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	593,685	460,797
State tax credits held for sale	1,458	3,585
Derivative financial instruments	5,403	4,016
Total assets	600,546	468,398
Liabilities
Derivative financial instruments		4,016
Total liabilities	5,403	4,016
Recurring basis | Obligations of U.S. Government-sponsored enterprises | Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	105,175	107,660
Recurring basis | Obligations of states and political subdivisions | Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	34,510	36,631
Recurring basis | Residential mortgage-backed securities | Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	429,001	316,506
Recurring basis | US Treasury Bill Securities [Member] | Estimate of Fair Value Measurement [Member]
Assets
Securities available for sale	24,999
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	24,999	0
State tax credits held for sale	0	0
Derivative financial instruments	0	0
Total assets	24,999	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 | Quoted Prices in Active Markets for Identical Assets (Level 1) | US Treasury Bill Securities [Member]
Assets
Securities available for sale	24,999
Recurring basis | Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	565,593	457,708
State tax credits held for sale	0	0
Derivative financial instruments	5,403	4,016
Total assets	570,996	461,724
Liabilities
Derivative financial instruments	5,403	4,016
Total liabilities	5,403	4,016
Recurring basis | Significant Other Observable Inputs (Level 2) | Obligations of U.S. Government-sponsored enterprises
Assets
Securities available for sale	105,175	107,660
Recurring basis | Significant Other Observable Inputs (Level 2) | Obligations of states and political subdivisions
Assets
Securities available for sale	31,417	33,542
Recurring basis | Significant Other Observable Inputs (Level 2) | Residential mortgage-backed securities
Assets
Securities available for sale	429,001	316,506
Recurring basis | Significant Other Observable Inputs (Level 2) | US Treasury Bill Securities [Member]
Assets
Securities available for sale	0
Recurring basis | Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	3,093	3,089
State tax credits held for sale	1,458	3,585
Derivative financial instruments	0	0
Total assets	4,551	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	3,093	3,089
Recurring basis | Significant Unobservable Inputs (Level 3) | Residential mortgage-backed securities
Assets
Securities available for sale	0	$ 0
Recurring basis | Significant Unobservable Inputs (Level 3) | US Treasury Bill Securities [Member]
Assets
Securities available for sale	$ 0

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)security	Dec. 31, 2016USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
State tax credits, held for sale	$ 35,431	$ 38,071
State Tax Credits Held For Sale, Fair Value Disclosure	$ 1,458	3,585
State Tax Credit Term	10 years
Years of Tax Credits Generated	10 years
Recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
State tax credits, held for sale	$ 35,400
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	$ 1,458	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	3
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	37,041	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	$ 1,458	$ 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
	Mar. 31, 2017	Mar. 31, 2016
Securities available for sale, at fair value
Level 3 Financial Instruments Measured at Fair Value
Beginning balance	$ 3,089	$ 3,077
Total gains:
Included in other comprehensive income	4	8
Purchases, sales, issuances and settlements:
Purchases	0	0
Ending balance	3,093	3,085
Change in unrealized gains (losses) relating to assets still held at the reporting date	4	8
State tax credits held for sale, at fair value
Level 3 Financial Instruments Measured at Fair Value
Beginning balance	3,585	5,941
Total gains:
Total gains:	40	76
Purchases, sales, issuances and settlements:
Sales	(2,167)	(1,284)
Ending balance	1,458	4,733
Change in unrealized gains (losses) relating to assets still held at the reporting date	$ (606)	$ (305)

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
	Mar. 31, 2017USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total (losses) gains for the year	$ 175
Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total (losses) gains for the year	157
Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total (losses) gains for the year	18
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
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
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
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	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
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
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	177
Significant Unobservable Inputs (Level 3) | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0
Significant Unobservable Inputs (Level 3) | Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	177
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	177
Estimate of Fair Value Measurement [Member] | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0
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	$ 177

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	Mar. 31, 2017	Dec. 31, 2016
Balance sheet assets
Securities available for sale	$ 593,685	$ 460,797
Securities held to maturity	79,236	80,463
State tax credits held for sale	1,458	3,585
Carrying Amount
Balance sheet assets
Cash and due from banks	73,387	54,288
Federal funds sold	1,112	446
Interest-bearing deposits	137,197	145,048
Securities available for sale	593,685	460,797
Securities held to maturity	79,236	80,463
Other investments, at cost	24,222	14,840
Loans held for sale	5,380	9,562
Derivative financial instruments	5,403	4,016
Portfolio loans, net	3,846,439	3,114,752
State tax credits held for sale	35,431	38,071
Accrued interest receivable	12,229	11,117
Balance sheet liabilities
Deposits	4,031,620	3,233,361
Subordinated debentures	118,067	105,540
Federal Home Loan Bank advances	151,115	0
Other borrowings	235,052	276,980
Derivative financial instruments	5,403	4,016
Accrued interest payable	1,914	1,105
Estimated fair value
Balance sheet assets
Cash and due from banks	73,387	54,288
Federal funds sold	1,112	446
Interest-bearing deposits	137,197	145,048
Securities available for sale	593,685	460,797
Securities held to maturity	78,617	79,639
Other investments, at cost	24,222	14,840
Loans held for sale	5,380	9,562
Derivative financial instruments	5,403	4,016
Portfolio loans, net	3,852,858	3,125,701
State tax credits held for sale	37,041	41,264
Accrued interest receivable	12,229	11,117
Balance sheet liabilities
Deposits	4,029,423	3,232,414
Subordinated debentures	99,517	86,052
Federal Home Loan Bank advances	151,020	0
Other borrowings	234,964	276,905
Derivative financial instruments	5,403	4,016
Accrued interest payable	$ 1,914	$ 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	Mar. 31, 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	$ 78,617	$ 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	3,852,858	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	0	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	4,029,423	3,232,414
Estimated fair value | Subordinated debentures
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	99,517	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	151,020
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	234,964	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	3,425,513	2,760,202
Level 1 | Subordinated debentures
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	78,617	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
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	99,517	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	151,020
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	234,964	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	3,852,858	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	0	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	603,910	472,212
Level 3 | Subordinated debentures
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