Enterprise Financial Services (EFSC) 10-K 24 Feb 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2016	Feb. 21, 2017	Jun. 30, 2016
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-K
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		23,435,163
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 533,965,736

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Assets
Cash and due from banks	$ 54,288	$ 47,935
Federal funds sold	446	91
Interest-bearing deposits (including $675 and $1,320 pledged as collateral, respectively)	144,068	46,131
Total cash and cash equivalents	198,802	94,157
Interest-bearing deposits greater than 90 days	980	1,000
Securities available for sale	460,797	451,770
Securities held to maturity	80,463	43,714
Loans held for sale	9,562	6,598
Portfolio loans	3,118,392	2,750,737
Less: Allowance for loan losses	37,565	33,441
Portfolio loans, net	3,080,827	2,717,296
Purchased credit impaired loans, net of allowance for loan losses ($5,844 and $10,175, respectively)	33,925	64,583
Total loans, net	3,114,752	2,781,879
Other real estate	980	8,366
Other investments, at cost	14,840	17,455
Fixed assets, net	14,910	14,842
Accrued interest receivable	11,117	8,399
State tax credits, held for sale, including $3,585 and $5,941 carried at fair value, respectively	38,071	45,850
Goodwill	30,334	30,334
Intangible assets, net	2,151	3,075
Other assets	103,569	101,044
Total assets	4,081,328	3,608,483
Liabilities and Shareholders' equity
Demand deposits	866,756	717,460
Interest-bearing transaction accounts	731,539	564,420
Money market accounts	1,050,472	1,053,662
Savings	111,435	92,861
Certificates of deposit:
Brokered	117,145	39,573
Other	356,014	316,615
Total deposits	3,233,361	2,784,591
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	105,540	56,807
Federal Home Loan Bank advances	0	110,000
Other borrowings	276,980	270,326
Accrued interest payable	1,105	629
Other liabilities	77,244	35,301
Total liabilities	3,694,230	3,257,654
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; 20,306,353 and 20,093,119 shares issued, respectively	203	201
Treasury stock, at cost; 261,718 and 76,000 shares, respectively	(6,632)	(1,743)
Additional paid in capital	213,078	210,589
Retained earnings	182,190	141,564
Accumulated other comprehensive income	(1,741)	218
Total shareholders' equity	387,098	350,829
Total liabilities and shareholders' equity	$ 4,081,328	$ 3,608,483

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Assets
Collateral pledged	$ 675	$ 1,320
Allowance for loan losses on Portfolio loans, covered under FDIC loss share	5,844	10,175
State Tax Credits Held For Sale, Fair Value Disclosure	3,585	5,941
Debt Issuance Cost	$ 1,267	$ 0
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	20,306,353	20,093,119
Treasury stock, shares	261,718	76,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest income:
Interest and fees on loans	$ 137,738	$ 122,370	$ 121,395
Interest on debt securities:
Taxable	9,590	8,842	8,711
Nontaxable	1,300	1,215	1,188
Interest on interest-bearing deposits	370	211	187
Dividends on equity securities	226	141	273
Total interest income	149,224	132,779	131,754
Interest expense:
Interest-bearing transaction accounts	1,370	1,149	653
Money market accounts	4,439	2,993	2,716
Savings accounts	262	219	201
Certificates of Deposit	4,770	6,051	6,917
Subordinated debentures	1,894	1,248	1,322
Federal Home Loan Bank advances	555	127	1,799
Notes payable and other borrowings	439	582	778
Total interest expense	13,729	12,369	14,386
Net interest income	135,495	120,410	117,368
Provision for portfolio loan losses	5,551	4,872	4,409
Provision (provision reversal) for purchased credit impaired loan losses	(1,946)	(4,414)	1,083
Net interest income after provision for loan losses	131,890	119,952	111,876
Noninterest income:
Service charges on deposit accounts	8,615	7,923	7,181
Wealth management revenue	6,729	7,007	6,942
Other service charges and fee income	3,958	3,241	2,953
Gain on state tax credits, net	2,647	2,720	2,252
Gain on sale of other real estate	1,837	142	1,531
Gain on sale of investment securities	86	23	0
Change in FDIC loss share receivable	0	(5,030)	(9,307)
Miscellaneous income	5,187	4,649	5,079
Total noninterest income	29,059	20,675	16,631
Noninterest expense:
Employee compensation and benefits	49,846	46,095	47,232
Occupancy	6,889	6,573	6,527
Data processing	4,723	4,339	4,481
Professional fees	3,825	3,465	3,825
FDIC and other insurance	3,018	2,790	2,884
Loan legal and other real estate expense	1,635	1,812	3,936
FDIC Loss Share Termination	0	2,436	0
FHLB prepayment penalty	0	0	2,936
FDIC clawback	0	760	1,201
Other	16,174	13,956	14,441
Total noninterest expense	86,110	82,226	87,463
Income before income tax expense	74,839	58,401	41,044
Income tax expense	26,002	19,951	13,871
Net income	$ 48,837	$ 38,450	$ 27,173
Earnings per common share
Basic (usd per share)	$ 2.44	$ 1.92	$ 1.38
Diluted (usd per share)	$ 2.41	$ 1.89	$ 1.35

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net income	$ 48,837	$ 38,450	$ 27,173
Other comprehensive (loss) income, net of tax:
Unrealized (losses) gains on investment securities arising during the period, net of income tax (benefit) expense of ($1,168), ($899), and $3,762, respectively	(1,906)	(1,449)	6,061
Less: Reclassification adjustment for realized gains on sale of securities available for sale included in net income, net of income tax expense of $33, $9, and $0, respectively	(53)	(14)	0
Total other comprehensive (loss) income	(1,959)	(1,463)	6,061
Total comprehensive income	$ 46,878	$ 36,987	$ 33,234

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other comprehensive income, tax:
Unrealized (loss)/gain on investment securities available for sale arising during the period, tax	$ (1,168)	$ (899)	$ 3,762
Reclassification adjustment for realized gains on sale of securities available for sale included in net income, tax	$ 33	$ 9	$ 0

Consolidated Statements of Shar

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, 2013	$ 279,705	$ 0	$ 194	$ (1,743)	$ 200,258	$ 85,376	$ (4,380)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	27,173	0	0	0	0	27,173	0
Other comprehensive income (loss)	6,061	0	0	0	0	0	6,061
Cash dividends paid on common shares	4,176	0	0	0	0	(4,176)	0
Issuance under equity compensation plans, net	(679)	0	2	0	(681)	0	0
Trust preferred securities conversion	5,002	0	3	0	4,999	0	0
Share-based compensation	2,950	0	0	0	2,950	0	0
Excess tax benefit related to equity compensation plans	205	0	0	0	205	0	0
Balance at Dec. 31, 2014	316,241	0	199	(1,743)	207,731	108,373	1,681
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	38,450	0	0	0	0	38,450	0
Other comprehensive income (loss)	(1,463)	0	0	0	0	0	(1,463)
Cash dividends paid on common shares	5,259	0	0	0	0	5,259	0
Issuance under equity compensation plans, net	(1,190)	0	2	0	(1,192)	0	0
Share-based compensation	3,601	0	0	0	3,601	0	0
Excess tax benefit related to equity compensation plans	449	0	0	0	449	0	0
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	48,837	0	0	0	0	48,837	0
Other comprehensive income (loss)	(1,959)	0	0	0	0	0	(1,959)
Cash dividends paid on common shares	8,211	0	0	0	0	(8,211)	0
Adjustments To Additional Paid In Capital, Repurchase Of Common Stock Warrants	(4,889)	0	0	4,889	0	0	0
Issuance under equity compensation plans, net	(2,203)	0	2	0	(2,205)	0	0
Share-based compensation	3,367	0	0	0	3,367	0	0
Excess tax benefit related to equity compensation plans	1,327	0	0	0	1,327	0	0
Balance at Dec. 31, 2016	$ 387,098	$ 0	$ 203	$ (6,632)	$ 213,078	$ 182,190	$ (1,741)

Consolidated Statements of Sha8

Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash dividends paid on common shares, per share	$ 0.41	$ 0.2625	$ 0.21
Issuance under equity compensation plans, shares	213,234	179,600	225,958
Stock Issued During Period, Shares, Conversion of Convertible Securities	0	0	287,852

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income	$ 48,837	$ 38,450	$ 27,173
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation	2,428	2,022	2,238
Provision for loan losses	3,605	458	5,492
Deferred income taxes	(7,263)	5,763	(4,277)
Net amortization of debt securities	3,225	3,256	3,810
Amortization of intangible assets	924	1,089	1,254
Gain on sale of investment securities	(86)	(23)	0
Mortgage loans originated for sale	(157,129)	(135,721)	(74,135)
Proceeds from mortgage loans sold	154,993	133,552	72,529
Gain on sale of other real estate	(1,837)	(142)	(1,531)
Gain on state tax credits, net	(2,647)	(2,720)	(2,252)
Excess tax benefit of share-based compensation	(1,327)	(449)	(205)
Share-based compensation	3,367	3,601	2,950
Valuation adjustment on other real estate	1	82	696
Net accretion of loan discount and indemnification asset	(11,057)	(7,805)	(9,879)
Changes in:
Accrued interest receivable	(2,718)	(443)	(653)
Accrued interest payable	476	(214)	(114)
Other assets	(7,740)	10,375	(205)
Other liabilities	41,943	7,582	49
Net cash provided by operating activities	82,521	47,187	31,494
Cash flows from investing activities:
Net increase in loans	(328,023)	(290,326)	(240,640)
Net cash proceeds received from FDIC loss share receivable	0	2,275	9,605
Proceeds from the termination of FDIC loss share agreements	0	1,253	0
Proceeds from the sale of debt securities, available for sale	2,493	41,069	0
Proceeds from the paydown or maturity of debt securities, available for sale	63,502	53,733	47,678
Proceeds from the paydown or maturity of debt securities, held to maturity	3,655	2,284	455
Proceeds from the redemption of other investments	52,279	39,929	29,045
Proceeds from the sale of state tax credits held for sale	18,757	16,337	12,814
Proceeds from the sale of other real estate	11,346	7,378	17,259
Payments for the purchase of:
Available for sale debt securities	(81,195)	(152,044)	(53,664)
Held to maturity debt securities	(40,529)	0	0
Other investments	(49,645)	(36,046)	(33,477)
State tax credits held for sale	(8,201)	(20,981)	0
Fixed assets	(2,496)	(2,111)	(1,901)
Net cash used in investing activities	(358,057)	(337,250)	(212,826)
Cash flows from financing activities:
Net increase (decrease) in noninterest-bearing deposit accounts	149,296	74,530	(10,756)
Net increase (decrease) in interest-bearing deposit accounts	299,474	218,551	(32,686)
Proceeds from the issuance of subordinated debentures	48,733	0	0
Proceeds from Federal Home Loan Bank advances	1,357,000	945,900	1,227,500
Repayments of Federal Home Loan Bank advances	(1,467,000)	(979,900)	(1,133,500)
Repayments of notes payable	0	(5,700)	(4,800)
Net increase in other borrowings	6,654	36,143	30,352
Cash dividends paid on common stock	(8,211)	(5,259)	(4,177)
Excess tax benefit of share-based compensation	1,327	449	205
Payments for the repurchase of common stock	(4,889)	0	0
Issuance of common stock	2	2	2
Proceeds from the issuance of equity instruments, net	(2,205)	(1,192)	(681)
Net cash provided by financing activities	380,181	283,524	71,459
Net increase (decrease) in cash and cash equivalents	104,645	(6,539)	(109,873)
Cash and cash equivalents, beginning of period	94,157	100,696	210,569
Cash and cash equivalents, end of period	198,802	94,157	100,696
Supplemental disclosures of cash flow information:
Cash paid during the period for interest	13,253	12,583	14,500
Cash paid during the period for income taxes	26,039	15,763	8,993
Noncash transactions:
Transfer to other real estate owned in settlement of loans	2,743	8,248	9,869
Sales of other real estate financed	140	0	8,083
Issuance of common stock from Trust Preferred Securities conversion	0	0	5,002
Transfer of securities from available for sale to held to maturity	$ 0	$ 0	$ 46,574

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The significant accounting policies used by the Company in the preparation of the consolidated financial statements are summarized below. Business and Consolidation Enterprise Financial Services Corp and subsidiaries (the “Company” or “Enterprise”) is a financial holding company that provides a full range of banking and wealth management services to individuals and corporate customers primarily located in the St. Louis, Kansas City, and Phoenix metropolitan markets through its banking subsidiary, Enterprise Bank & Trust (the “Bank”). The 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. The Company is subject to competition from other financial and nonfinancial institutions providing financial services in the markets served by the Company's subsidiary. Additionally, the Company and its banking subsidiary are subject to the regulations of certain federal and state agencies and undergo periodic examinations by those regulatory agencies. The Company has one operating segment. Use of Estimates The consolidated financial statements of the Company have been prepared in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”.) In preparing the consolidated financial statements, management is required to make estimates and assumptions, which significantly affect the reported amounts in the consolidated financial statements. Such estimates include the valuation of loans, goodwill, intangible assets, indemnification assets, and other long-lived assets, along with assumptions used in the calculation of income taxes, among others. These estimates and assumptions are based on management's best estimates and judgment. Management evaluates its estimates and assumptions on an ongoing basis using experience and other factors, including the current economic environment, which management believes to be reasonable under the circumstances. Management adjusts such estimates and assumptions when facts and circumstances dictate. Decreased real estate values, volatile credit markets, and unemployment have combined to increase the uncertainty inherent in such estimates and assumptions. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Changes in those estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods. Cash Flow Information For purposes of reporting cash flows, the Company considers cash and due from banks, interest-bearing deposits and federal funds sold that mature within 90 days to be cash and cash equivalents. At December 31, 2016 and 2015 , approximately $18.2 million , and $13.8 million , respectively, of cash and due from banks represented required reserves on deposits maintained by the Company in accordance with Federal Reserve Bank requirements. Investments The Company has classified all investments in debt securities as available for sale or held to maturity. Securities classified as available for sale are carried at fair value. Unrealized holding gains and losses for available for sale securities are excluded from earnings and reported as a net amount in a separate component of shareholders' equity until realized. All previous fair value adjustments included in the separate component of shareholders' equity are reversed upon sale. Securities classified as held to maturity are carried at historical cost and adjusted for amortization of premiums and accretion of discounts. Declines in the fair value of securities below their cost deemed to be other-than-temporary are reflected in operations as realized losses. In estimating other-than-temporary impairment losses, 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 (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's more likely than not the Company would be required to sell the security before its anticipated recovery in market value. Premiums and discounts are amortized or accreted over the expected lives of the respective securities as an adjustment to yield using the interest method. Dividend and interest income is recognized when earned. Realized gains and losses are included in earnings and are derived using the specific identification method for determining the cost of securities sold. Loans Held for Sale The Company provides long-term financing of one-to-four-family residential real estate by originating fixed and variable rate loans. Long-term fixed and variable rate loans are sold into the secondary market with limited recourse. Upon receipt of an application for a real estate loan, the Company determines whether the loan will be sold into the secondary market or retained in the Company's loan portfolio. The interest rates on the loans sold are locked with the buyer and the Company bears no interest rate risk related to these loans. Mortgage loans held for sale are carried at the lower of cost or fair value, which is determined on a specific identification method. The Company does not retain servicing on any loans sold, nor did the Company have any capitalized mortgage servicing rights at December 31, 2016 or 2015 . Gains on the sale of loans held for sale are reported net of direct origination fees and costs in the Company's consolidated statements of operations. Portfolio Loans Loans are reported at the principal balance outstanding, net of unearned fees, costs, and premiums or discounts on acquired loans. Loan origination fees, direct origination costs, and premiums or discounts resulting from acquired loans are deferred and recognized over the lives of the related loans as a yield adjustment using the interest method. Interest income on loans is accrued to income based on the principal amount outstanding. The recognition of interest income is discontinued when a loan becomes 90 days past due or a significant deterioration in the borrower's credit has occurred which, in management's judgment, negatively impacts the collectibility of the loan. Unpaid interest on such loans is reversed at the time the loan becomes uncollectible and subsequent interest payments received are applied to principal if any doubt exists as to the collectibility of such principal; otherwise, such receipts are recorded as interest income. Loans that have not been restructured are returned to accrual status when management believes full collectibility of principal and interest is expected. Non-accrual loans that have been restructured will remain in a non-accrual status until the borrower has made at least six months of consecutive contractual payments. Purchased Credit Impaired ("PCI") Loans Loans acquired through the completion of a transfer, including loans acquired in a business combination, that have evidence of deterioration of credit quality since origination and for which it is probable, at acquisition, that the Company will be unable to collect all contractually required payments receivable, are initially recorded at fair value (as determined by the present value of expected future cash flows) with no valuation allowance. The difference between the undiscounted cash flows expected at acquisition and the investment in the loans, or the “accretable yield,” is recognized as interest income on a level-yield method over the life of the loans. Contractually required payments for interest and principal that exceed the undiscounted cash flows expected at acquisition, or the “nonaccretable difference,” are not recognized as a yield adjustment or as a loss accrual or a valuation allowance. The Company aggregates individual loans with common risk characteristics into pools of loans. Increases in expected cash flows subsequent to the initial investment are recognized prospectively through adjustment of the yield on the loans over their remaining lives. Decreases in expected cash flows due to an inability to collect contractual cash flows are recognized as impairment through the provision for loan losses account. Any allowance for loan loss on these pools reflect only losses incurred after the acquisition (meaning the present value of all cash flows expected at acquisition that ultimately are not to be received). Any disposals of loans, including sales of loans, payments in full or foreclosures result in the removal of the loan from the loan pool at the carrying amount with differences in actual results reflected in interest income. Impaired Loans Loans are considered “impaired” when it becomes probable that the Company will be unable to collect all amounts due according to the loan's contractual terms. Non-accrual loans, loans past due greater than 90 days and still accruing, unless adequately secured and in the process of collection, and restructured loans qualify as “impaired loans.” Restructured loans involve the granting of a concession to a borrower experiencing financial difficulty involving the modification of terms of the loan, such as changes in payment schedule or interest rate. When measuring impairment, the expected future cash flows of an impaired loan are discounted at the loan's effective interest rate at origination. Alternatively, impairment can be measured by reference to an observable market price, if one exists, or the fair value of the collateral for a collateral-dependent loan. Interest income on impaired loans is not accrued but is recorded when cash is received and only if principal is considered to be fully collectible. Loans and leases, which are deemed uncollectible, are charged off to the allowance for loan losses, while recoveries of amounts previously charged off are credited to the allowance for loan losses. Impaired loans exclude PCI loans, which are accounted for on a pool basis and are generally considered accruing and performing loans, as the loans accrete interest income over the estimated life of the loan when cash flows are reasonably estimable. Accordingly, PCI loans that are contractually past due may still be considered to be accruing and performing loans. If the timing and amount of future cash flows is not reasonably estimable, the loans may be classified as nonaccrual loans and the purchase price discount on those loans is not recorded as interest income until the timing and amount of future cash flows can be reasonably estimated. See Note 6 – Purchased Credit Impaired Loans for more information on these loans. Loans are generally placed on non-accrual status when contractually past due 90 days or more as to interest or principal payments. Additionally, whenever management becomes aware of facts or circumstances that may adversely impact the collectability of principal or interest on loans, it is management's practice to place such loans on non-accrual status immediately, rather than delaying such action until the loans become 90 days past due. Previously accrued and uncollected interest on such loans is reversed. Income is recorded only to the extent that a determination has been made that the principal balance of the loan is collectable and the interest payments are subsequently received in cash, or for a restructured loan, the borrower has made six consecutive contractual payments. If collectability of the principal is in doubt, payments received are applied to loan principal. Loans past due 90 days or more but still accruing interest are also generally included in nonperforming loans. Loans past due 90 days or more but still accruing are classified as such where the underlying loans are both well secured (the collateral value is sufficient to cover principal and accrued interest) and are in the process of collection. At December 31, 2016 , we did not have any loans past due greater than 90 days and not included in nonperforming loans. Loan Charge-Offs Loans are charged-off when the primary and secondary sources of repayment (cash flow, collateral, guarantors, etc.) are less than their carrying value. Allowance For Loan Losses The allowance for loan losses is increased by provision charged to expense and is available to absorb charge-offs, net of recoveries. Management utilizes a systematic, documented approach in determining the appropriate level of the allowance for loan losses. The level of the allowance reflects management's continuing evaluation of industry concentrations; specific credit risks; loan loss experience; current loan portfolio quality; present economic, political and regulatory conditions; and probable losses inherent in the current loan portfolio. The determination of the appropriate level of the allowance for loan losses inherently involves a degree of subjectivity and requires that the Company make significant estimates of current credit risks and future trends, all of which may undergo material changes. Changes in economic conditions affecting borrowers, new information regarding existing loans, identification of additional problem loans and other factors, both within and outside of our control, may require an increase in the allowance for loan losses. Management believes the allowance for loan losses is adequate to absorb inherent losses in the loan portfolio. While management uses available information to recognize losses on loans, future additions to the allowance may be necessary based on changes in economic conditions and other factors. In addition, various regulatory agencies, as an integral part of the examination process, periodically review the Bank's loan portfolio. Such agencies may require additions to the allowance for loan losses based on their judgments and interpretations of information available to them at the time of their examinations. Allowance for Loan Losses on PCI Loans The Company updates its cash flow projections for PCI loans on a periodic basis. Assumptions utilized in this process include projections related to probability of default, loss severity, prepayment, extensions and recovery lag. Projections related to probability of default and prepayment are calculated utilizing a loan migration analysis. The loan migration analysis is a matrix of probability that specifies the probability of a loan pool transitioning into a particular delinquency or liquidation state given its current state at the re-measurement date. Loss severity factors are based upon industry data and experience. Any decreases in expected cash flows after the acquisition date and subsequent measurement periods are recognized by recording an impairment in the provision for loan losses. See Purchased Credit Impaired Loans above for further discussion. Any increase in expected future cash flows due to a decrease in expected credit losses will reverse previously recorded impairment, if any, and add to the accretable yield on the loan pool, prospectively. Other Real Estate Other real estate represents property acquired through foreclosure or deeded to the Company in lieu of foreclosure on loans on which the borrowers have defaulted on the payment of principal or interest. Other real estate is recorded on an individual asset basis at the lower of cost or fair value less estimated costs to sell. The fair value of other real estate is based upon estimates of future cash flows, market value of similar assets, if available, or independent appraisals. These estimates involve significant uncertainties and judgments. As a result, fair value estimates may not be realizable in a current sale or settlement of the other real estate. Subsequent reductions in fair value are expensed within noninterest expense. Gains and losses resulting from the sale of other real estate are credited or charged to current period earnings. Costs of maintaining and operating other real estate are expensed as incurred, and expenditures to complete or improve other real estate properties are capitalized if the expenditures are expected to be recovered upon ultimate sale of the property. FDIC Loss Share Receivable and Clawback Liability As part of several FDIC-assisted transactions, the Bank entered into loss sharing agreements with the FDIC from 2009-2011. In 2015, the Bank entered into an agreement with the FDIC to terminate all existing loss sharing agreements. This termination resulted in the removal of the remaining clawback liability of $3.5 million and FDIC receivable of $7.2 million . The following policy discussion refers to transactions prior to December 7, 2015. The FDIC reimbursed the Bank for a percentage of realized losses on loans and foreclosed real estate covered under the agreement (“covered assets”). In addition, the Bank was reimbursed for certain expenses related to the covered assets. At the acquisition date, the fair value of the amount due from the FDIC (“FDIC Loss Share Receivable") was estimated based on expected losses and cash flows on the covered assets. The FDIC Loss Share Receivable was measured separately from the related covered assets and recorded separately on the balance sheet, because it is not contractually embedded in the covered assets and was not transferable. Although these assets are contractual receivables from the FDIC, there are no contractual interest rates. Subsequent to initial recognition, but prior to early termination in the fourth quarter of 2015, the FDIC Loss Share Receivable was reviewed quarterly and adjusted for any changes in expected cash flows. These adjustments were measured on the same basis as the related covered assets. Any decrease in expected cash flows due to an increase in expected credit losses increased the FDIC Loss Share Receivable which partially offset the impairment recorded on the PCI loans. The amount of the increase was recorded in noninterest income and was determined based on the specific loss share agreement, but was generally 80% of the losses. Any increase in expected future cash flows due to a decrease in expected credit losses decreased the accretion of the FDIC Loss Share Receivable prospectively over its remaining life. Increases and decreases to the FDIC Loss Share Receivable were recorded as adjustments to noninterest income. As stipulated in some of its agreements with the FDIC, the Company may have been required to reimburse the FDIC if certain levels of cash flows were met over the duration of a loss share agreement. This reimbursement, or clawback liability, was measured quarterly. Fixed Assets Buildings, leasehold improvements, furniture, fixtures, equipment, and capitalized software are stated at cost less accumulated depreciation. All categories are computed using the straight-line method over their respective estimated useful lives. Furniture, fixtures and equipment is depreciated over three to ten years, buildings and leasehold improvements over ten to forty years, and capitalized software over three years based upon estimated lives or lease obligation periods. State Tax Credits Held for Sale The Company has purchased the rights to receive 10 -year streams of state tax credits at agreed upon discount rates and sells such tax credits to its clients and others. All state tax credits purchased prior to 2009 are accounted for at fair value. All state tax credits purchased since 2009 are accounted for at cost. The Company elected not to account for the state tax credits purchased since 2009 at fair value in order to limit the volatility of the fair value changes in the Company's consolidated statements of operations. Cash Surrender Value of Life Insurance The Company has purchased bank-owned life insurance policies on certain bank officers. Bank-owned life insurance is recorded at its cash surrender value. Changes in the cash surrender values are included in noninterest income. Federal Home Loan Bank Stock The Bank, as a member of the Federal Home Loan Bank of Des Moines (“FHLB”), is required to maintain an investment in the capital stock of the FHLB. The stock is redeemable at par by the FHLB, and is, therefore, carried at cost and periodically evaluated for impairment. The Company records FHLB dividends in interest income. Goodwill and Other Intangible Assets The Company tests goodwill for impairment on an annual basis and whenever events or changes in circumstances indicate that the Company may not be able to recover the respective asset's carrying amount. The Company's annual test for impairment was performed in the fourth quarter of December 31, 2016 . Such tests involve the use of estimates and assumptions. Core deposit intangibles are amortized using an accelerated method over an estimated useful life of approximately 10 years. The Company identifies potential goodwill impairments by first performing a qualitative assessment and then by comparing the fair value of a reporting unit to its carrying amount, including goodwill. Goodwill impairment is not indicated as long as it is more likely than not that impairment has not occurred based on the qualitative assessment or based on the quantitative assessment the fair value of the reporting unit is greater than its carrying value. The second step of the impairment test is only required if a goodwill impairment is identified in step one. The second step of the test compares the implied fair value of goodwill to its carrying amount. If the carrying amount of goodwill exceeds its implied fair value, an impairment loss is recognized. That loss is equal to the carrying amount of goodwill that is in excess of its implied fair market value. Impairment of Long-Lived Assets Long-lived assets, such as fixed assets and purchased intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized in the amount by which the carrying amount of the asset exceeds the fair value of the asset. Assets to be disposed of are separately presented in the balance sheet and reported at the lower of the carrying amount or fair value less costs to sell, and are no longer depreciated. The assets and liabilities of a disposal group classified as held for sale are presented separately in the appropriate asset and liability sections of the balance sheet. Derivative Financial Instruments and Hedging Activities The Company uses derivative financial instruments to assist in the management of interest rate sensitivity and to modify the repricing, maturity and option characteristics of certain assets and liabilities. In addition, the Company also offers an interest rate hedge program that includes interest rate swaps to assist its customers in managing their interest rate risk profile. In order to eliminate the interest rate risk associated with offering these products, the Company enters into derivative contracts with third parties to offset the customer contracts. Derivative instruments are required to be measured at fair value and recognized as either assets or liabilities in the consolidated financial statements. Fair value represents the payment the Company would receive or pay if the item were sold or bought in a current transaction. The accounting for changes in fair value (gains or losses) of a hedged item is dependent on whether the related derivative is designated and qualifies for “hedge accounting.” The Company assigns derivatives to one of these categories at the purchase date: cash flow hedge, fair value hedge, or non-designated derivatives. An assessment of the expected and ongoing hedge effectiveness of any derivative designated a fair value hedge or cash flow hedge is performed as required by the accounting standards. Derivatives are included in other assets and other liabilities in the consolidated balance sheets. Generally, the only derivative instruments used by the Company have been interest rate swaps and interest rate caps. The Company does not currently have derivative instruments designated as fair value or cash flow hedges. Certain derivative financial instruments are not designated as cash flow or as fair value hedges for accounting purposes. These non-designated derivatives are intended to provide interest rate protection on net interest income or noninterest income but do not meet hedge accounting treatment. Customer accommodation interest rate swap contracts are not designated as hedging instruments. Changes in the fair value of these instruments are recorded in interest income or noninterest income in the consolidated statements of income depending on the underlying hedged item. Income Taxes The Company and its subsidiaries file a consolidated federal income tax return. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled. We evaluated the need for deferred tax asset valuation allowances based on a more-likely-than-not standard. The ability to realize deferred tax assets depends on the ability to generate sufficient positive taxable income within the carryback or carryforward periods provided for in the laws for each applicable taxing jurisdiction. We consider the following possible sources of taxable income: future reversal patterns of existing taxable temporary differences, future taxable income exclusive of reversing temporary differences, taxable income in prior carryback years and the availability of qualified tax planning strategies. The assessment regarding whether a valuation allowance is required or should be adjusted depends on all available positive and negative factors including, but not limited to, nature, frequency, and severity of recent losses, duration of available carryforward periods, experience with tax attributes expiring unused and near and medium term financial outlook. Because of the complexity of tax laws and regulations, interpretation can be difficult and subject to legal judgment given specific facts and circumstances. It is possible that others, given the same information, may at any point in time reach different reasonable conclusions regarding the estimated amounts of accrued taxes. Stock-Based Compensation Stock-based compensation is recognized as an expense for stock options, restricted stock awards, and restricted stock units granted to employees in return for employee service. Equity classified awards are measured at the grant date fair value using either an observable market value or a valuation methodology, and recognized over the requisite service period on a straight-line basis, reduced for estimated forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. A description of the Company's stock-based employee compensation plan is described in Note 16 - Compensation Plans. Acquisitions and Divestitures 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, including the amount assigned to identifiable intangible assets. The purchase price allocation process requires an estimation of the fair values of the assets acquired and the liabilities assumed. When a business combination agreement provides for an adjustment to the cost of the combination contingent on future events, the Company includes an estimate of the acquisition-date fair value as part of the cost of the combination. The results of operations of the acquired business are included in the Company's consolidated financial statements from the respective date of acquisition. As a general rule, goodwill established in connection with a stock purchase is non-deductible for tax purposes. For divestitures, the Company measures an asset (disposal group) classified as held for sale at the lower of its carrying value at the date the asset is initially classified as held for sale or its fair value less costs to sell. The Company reports the results of operations of an entity or group of components that either has been disposed of or held for sale as discontinued operations only if the disposal of that component represents a strategic shift that has or will have a major effect on an entity's operations and financial results. Any incremental direct costs incurred to transact the sale are allocated against the gain or loss on the sale. These costs would include items like legal fees, title transfer fees, broker fees, etc. Any goodwill and intangible assets associated with the portion of the reporting unit to be disposed of is included in the carrying amount of the business in determining the gain or loss on the sale. The Company has acquired a portfolio of PCI assets through FDIC assisted transactions. The PCI loans acquired were recorded at estimated fair value. As such, there was no allowance for credit losses established related to the acquired loans at the various acquisition dates and no carryover of the related allowance from the failed banks. The loans are accounted for in accordance with guidance for certain loans acquired in a transfer, when the loans have evidence of credit deterioration and it is probable at the date of acquisition that the acquirer will not collect all contractually required principal and interest payments. The difference between contractually required payments and the cash flows expected to be collected at acquisition is referred to as the non-accretable difference. Subsequent decreases to the expected cash flows will generally result in a provision for loan losses. Subsequent increases in cash flows result in a reversal of the provision for loan losses to the extent of prior charges and an adjustment in accretable yield, which will have a positive impact on interest income, prospectively. Basic and Diluted Earnings Per Common Share Basic earnings per common share data is calculated by dividing net income available to common shareholders 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 and the if-converted method for convertible securities related to the issuance of trust preferred securities. Consolidated Statement of Comprehensive Income The Consolidated Statement of Comprehensive Income includes the amount and the related tax impact that have been reclassified from accumulated other comprehensive income to net income. The classification adjustment for unrealized loss/gain on sale of securities included in net income has been recorded through the gain on sale of investment securities line item, within noninterest income, in the Company's Consolidated Statements of Operations.

Acquisitions & Divestitures

Acquisitions & Divestitures	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Acquisitions and Divestitures	ACQUISITIONS & DIVESTITURES Acquisition of Jefferson County Bancshares, Inc. On October 10, 2016 , the Company entered into a definitive merger agreement to acquire 100% of Jefferson County Bancshares, Inc. (“JCB”). JCB and its wholly-owned subsidiary, Eagle Bank and Trust Company of Missouri, have $937 million in assets, $699 million in loans, and $767 million in deposits as of December 31, 2016 . JCB operates 13 full service retail and commercial banking offices in metropolitan St. Louis and Perry Counties. At the closing of the acquisition on February 10, 2017 , 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 approximately $29.3 million in 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 approximately $171.0 million , including JCB’s common stock and stock options. The Company also recognized $1.4 million of acquisition related costs that were recorded in noninterest expense in the statement of operations for the year ended December 31, 2016 . The acquisition of JCB will be 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 valuation of assets acquired and liabilities assumed has not yet been finalized and as a result certain disclosures are not available. Due to the timing of the acquisition date, the Company has performed limited valuation procedures, and the valuation of nearly all assets acquired and liabilities assumed is incomplete.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE The following table presents a summary of per common share data and amounts for the periods indicated. Years ended December 31, (in thousands, except share and per share data) 2016 2015 2014 Net income as reported $ 48,837 $ 38,450 $ 27,173 Impact of assumed conversions Interest on 9% convertible trust preferred securities, net of income tax — — 66 Net income available to common shareholders after assumed conversions $ 48,837 $ 38,450 $ 27,239 Weighted average common shares outstanding 20,003 19,984 19,761 Incremental shares from assumed conversions of convertible trust preferred securities — — 57 Additional dilutive common stock equivalents 287 333 292 Weighted average diluted common shares outstanding 20,290 20,317 20,110 Basic earnings per common share: $ 2.44 $ 1.92 $ 1.38 Diluted earnings per common share: $ 2.41 $ 1.89 $ 1.35 There were zero , 0.1 million , and 0.3 million common stock equivalents for fiscal years 2016 , 2015 , and 2014 , respectively, which were excluded from the earnings per share calculation because their effect was anti-dilutive.

Investments

Investments	12 Months Ended
	Dec. 31, 2016
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: 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 December 31, 2015 (in thousands) Amortized Cost Gross Gross Fair Value Available for sale securities: Obligations of U.S. Government-sponsored enterprises $ 98,699 $ 309 $ — $ 99,008 Obligations of states and political subdivisions 40,700 1,343 (342 ) 41,701 Agency mortgage-backed securities 311,516 2,046 (2,501 ) 311,061 Total securities available for sale $ 450,915 $ 3,698 $ (2,843 ) $ 451,770 Held to maturity securities: Obligations of states and political subdivisions $ 14,831 $ 63 $ (50 ) $ 14,844 Agency mortgage-backed securities 28,883 — (286 ) 28,597 Total securities held to maturity $ 43,714 $ 63 $ (336 ) $ 43,441 At December 31, 2016 , and 2015 , there were no holdings of securities of any one issuer in an amount greater than 10% of shareholders’ equity, other than the 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 $407.3 million and $334.4 million at December 31, 2016 , and December 31, 2015 , 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 December 31, 2016 , by contractual maturity, are shown below. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. The weighted average life of the mortgage-backed securities is approximately 4 years. Available for sale Held to maturity (in thousands) Amortized Cost Estimated Fair Value Amortized Cost Estimated Due in one year or less $ 52,457 $ 52,574 $ 658 $ 655 Due after one year through five years 76,529 77,254 5,609 5,559 Due after five years through ten years 11,912 11,842 7,380 7,241 Due after ten years 2,900 2,620 1,112 1,073 Mortgage-backed securities 319,345 316,507 65,704 65,111 $ 463,143 $ 460,797 $ 80,463 $ 79,639 The following table represents a summary of investment securities that had an unrealized loss: 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 December 31, 2015 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 2,199 12 9,395 380 11,594 392 Agency mortgage-backed securities 189,229 2,050 21,020 737 210,249 2,787 $ 191,428 $ 2,062 $ 30,415 $ 1,117 $ 221,843 $ 3,179 The unrealized losses at both December 31, 2016 , and 2015 , 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 that the Company would be required to sell the security before its anticipated recovery in market value. At December 31, 2016 and 2015 , management performed its quarterly analysis of all securities with an unrealized loss and concluded no individual securities were other-than-temporarily impaired. The gross gains and losses realized from sales of available for sale investment securities were as follows: December 31, (in thousands) 2016 2015 2014 Gross gains realized $ 86 $ 63 $ — Gross losses realized — (40 ) — Proceeds from sales 2,493 41,069 — Other Investments, At Cost As a member of the FHLB system administered by the Federal Housing Finance Agency, the Bank is required to maintain a minimum investment in capital stock with the FHLB Des Moines consisting of membership stock and activity-based stock. The FHLB capital stock of $4.4 million is recorded at cost, which represents redemption value, and is included in other investments in the consolidated balance sheets. The remaining amounts in other investments include the Company's investment in unconsolidated trusts used to issue preferred securities to third parties (see Note 11 – Subordinated Debentures) and various private equity investments.

Portfolio Loans

Portfolio Loans	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Portfolio Loans	PORTFOLIO LOANS Below is a summary of portfolio loans by category at December 31, 2016 and 2015 : (in thousands) December 31, 2016 December 31, 2015 Commercial and industrial $ 1,632,714 $ 1,484,327 Real estate loans: Commercial - investor owned 544,808 428,064 Commercial - owner occupied 350,148 342,959 Construction and land development 194,542 161,061 Residential 240,760 196,498 Total real estate loans 1,330,258 1,128,582 Consumer and other 156,182 137,537 Portfolio loans, before unearned loan (fees) costs 3,119,154 2,750,446 Unearned loan (fees) costs, net (762 ) 291 Portfolio loans $ 3,118,392 $ 2,750,737 Following is a summary of activity for the years ended December 31, 2016 , 2015 , and 2014 of loans to executive officers and directors, or to entities in which such individuals had beneficial interests as a shareholder, officer, or director. Such loans were made in the normal course of business on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with other customers and did not involve more than the normal risk of collectibility. (in thousands) December 31, 2016 December 31, 2015 December 31, 2014 Balance at beginning of year $ 4,394 $ 13,513 $ 11,752 New loans and advances 11,539 641 11,796 Payments and other reductions (527 ) (9,760 ) (10,035 ) Balance at end of year $ 15,406 $ 4,394 $ 13,513 A summary of activity in the allowance for portfolio loan losses and the recorded investment in portfolio loans by class and category based on impairment method for the years ended indicated below 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 Balance at December 31, 2016 Allowance for loan losses: Balance, beginning of year $ 22,056 $ 3,484 $ 2,969 $ 1,704 $ 1,796 $ 1,432 $ 33,441 Provision (provision reversal) 6,569 (11 ) (1,202 ) (1,334 ) 129 1,400 5,551 Losses charged off (2,303 ) (95 ) — — (25 ) (1,912 ) (4,335 ) Recoveries 674 42 1,123 934 123 12 2,908 Balance, end of year $ 26,996 $ 3,420 $ 2,890 $ 1,304 $ 2,023 $ 932 $ 37,565 Balance at December 31, 2015 Allowance for loan losses: Balance, beginning of year $ 16,983 $ 4,382 $ 3,135 $ 1,715 $ 2,830 $ 1,140 $ 30,185 Provision (provision reversal) 6,976 (303 ) (1,626 ) (335 ) (58 ) 218 4,872 Losses charged off (3,699 ) (664 ) (38 ) (350 ) (1,313 ) (27 ) (6,091 ) Recoveries 1,796 69 1,498 674 337 101 4,475 Balance, end of year $ 22,056 $ 3,484 $ 2,969 $ 1,704 $ 1,796 $ 1,432 $ 33,441 Balance at December 31, 2014 Allowance for loan losses: Balance, beginning of year $ 12,246 $ 6,600 $ 4,096 $ 2,136 $ 2,019 $ 192 $ 27,289 Provision (provision reversal) 6,707 (2,063 ) (1,517 ) (322 ) 525 1,079 4,409 Losses charged off (3,738 ) (250 ) (450 ) (905 ) (48 ) (165 ) (5,556 ) Recoveries 1,768 95 1,006 806 334 34 4,043 Balance, end of year $ 16,983 $ 4,382 $ 3,135 $ 1,715 $ 2,830 $ 1,140 $ 30,185 (in thousands) Commercial and industrial CRE - investor owned CRE - owner occupied Construction and land development Residential real estate Consumer and other Total 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 Balance December 31, 2015 Allowance for loan losses - Ending balance: Individually evaluated for impairment $ 1,953 $ — $ 6 $ 369 $ 7 $ — $ 2,335 Collectively evaluated for impairment 20,103 3,484 2,963 1,335 1,789 1,432 31,106 Total $ 22,056 $ 3,484 $ 2,969 $ 1,704 $ 1,796 $ 1,432 $ 33,441 Loans - Ending balance: Individually evaluated for impairment $ 4,514 $ 921 $ 1,962 $ 2,800 $ 681 $ — $ 10,878 Collectively evaluated for impairment 1,479,813 427,143 340,997 158,261 195,817 137,828 2,739,859 Total $ 1,484,327 $ 428,064 $ 342,959 $ 161,061 $ 196,498 $ 137,828 $ 2,750,737 A summary of portfolio loans individually evaluated for impairment by category at December 31, 2016 and 2015 , is as follows: 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 December 31, 2015 (in thousands) Unpaid Recorded Recorded Allowance Total Related Allowance Average Commercial and industrial $ 5,554 $ 509 $ 4,204 $ 4,713 $ 1,953 $ 6,970 Real estate: Commercial - investor owned 927 927 — 927 — 970 Commercial - owner occupied 329 85 113 198 6 301 Construction and land development 4,349 2,914 530 3,444 369 3,001 Residential 705 637 68 705 7 682 Consumer and other — — — — — — Total $ 11,864 $ 5,072 $ 4,915 $ 9,987 $ 2,335 $ 11,924 The following table presents details for past due and impaired loans: December 31, (in thousands) 2016 2015 2014 Total interest income that would have been recognized under original terms on impaired loans $ 1,079 $ 1,038 $ 1,013 Total cash received and recognized as interest income on impaired loans 251 226 118 Total interest income recognized on impaired loans still accruing 155 36 39 There were no loans over 90 days past due and still accruing interest at December 31, 2016 or 2015 . The recorded investment in impaired portfolio loans by category at December 31, 2016 and 2015 , is as follows: December 31, 2016 (in thousands) Non-accrual Restructured 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 December 31, 2015 (in thousands) Non-accrual Restructured Total Commercial and industrial $ 4,406 $ 307 $ 4,713 Real estate: Commercial - investor owned 927 — 927 Commercial - owner occupied 198 — 198 Construction and land development 3,444 — 3,444 Residential 705 — 705 Consumer and other — — — Total $ 9,680 $ 307 $ 9,987 The recorded investment by category for the portfolio loans that have been restructured during the years ended December 31, 2016 and 2015 , is as follows: Year ended December 31, 2016 Year ended December 31, 2015 (in thousands, except for number of loans) Number of Loans Pre-Modification Outstanding Recorded Balance Post-Modification Outstanding Recorded Balance Number of Loans Pre-Modification Outstanding Recorded Balance Post-Modification Outstanding Recorded Balance Commercial and industrial 4 $ 12,114 $ 12,114 1 $ 303 $ 303 Real estate: Commercial - investor owned 1 248 248 — — — Commercial - owner occupied 1 13 13 — — — Construction and land development 1 20 20 — — — Residential — — — — — — Consumer and other — — — — — — Total 7 $ 12,395 $ 12,395 1 $ 303 $ 303 The restructured portfolio loans primarily resulted from interest rate concessions and changing the terms of the loans. As of December 31, 2016 , the Company allocated $0.7 million of specific reserves to loans that have been restructured. No loans that were previously restructured subsequently defaulted during the years ended December 31, 2016 and 2015 . The aging of the recorded investment in past due portfolio loans by portfolio class and category at December 31, 2016 and 2015 is shown below: 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 December 31, 2015 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ 505 $ 888 $ 1,393 $ 1,482,934 $ 1,484,327 Real estate: Commercial - investor owned 464 — 464 427,600 428,064 Commercial - owner occupied 94 184 278 342,681 342,959 Construction and land development 384 2,273 2,657 158,404 161,061 Residential 70 681 751 195,747 196,498 Consumer and other 20 — 20 137,808 137,828 Total $ 1,537 $ 4,026 $ 5,563 $ 2,745,174 $ 2,750,737 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, historical 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 portfolio loans by portfolio class and category at December 31, 2016 and December 31, 2015 is as follows: December 31, 2016 (in thousands) Pass (1-6) Watch (7) Substandard (8) 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 December 31, 2015 (in thousands) Pass (1-6) Watch (7) Substandard (8) Total Commercial and industrial $ 1,356,864 $ 90,370 $ 37,093 $ 1,484,327 Real estate: Commercial - investor owned 403,820 18,868 5,376 428,064 Commercial - owner occupied 314,791 24,727 3,441 342,959 Construction and land development 146,601 10,114 4,346 161,061 Residential 188,269 5,138 3,091 196,498 Consumer and other 131,060 721 6,047 137,828 Total $ 2,541,405 $ 149,938 $ 59,394 $ 2,750,737

Purchased Credit Impaired ("PCI

Purchased Credit Impaired ("PCI") Loans	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Purchased Credit Impaired (PCI) Loans	PURCHASED CREDIT IMPAIRED ("PCI") LOANS Below is a summary of PCI loans by category at December 31, 2016 and 2015 : December 31, 2016 December 31, 2015 ($ in thousands) Weighted- Average Risk Rating 1 Recorded Investment PCI Loans Weighted- Average Risk Rating 1 Recorded Investment PCI Loans Commercial and industrial 5.87 $ 3,523 6.70 $ 3,863 Real estate loans: Commercial - investor owned 6.95 8,162 6.98 25,272 Commercial - owner occupied 6.39 11,863 6.30 19,414 Construction and land development 5.80 4,365 6.28 6,838 Residential 5.64 11,792 5.44 19,287 Total real estate loans 36,182 70,811 Consumer and other 1.64 64 1.89 84 Purchased credit impaired loans $ 39,769 $ 74,758 (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 December 31, 2016 and 2015 is shown below: 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 December 31, 2015 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ — $ — $ — $ 3,863 $ 3,863 Real estate: Commercial - investor owned 2,342 3,661 6,003 19,269 25,272 Commercial - owner occupied 731 — 731 18,683 19,414 Construction and land development — — — 6,838 6,838 Residential 1,594 130 1,724 17,563 19,287 Consumer and other 4 — 4 80 84 Total $ 4,671 $ 3,791 $ 8,462 $ 66,296 $ 74,758 The following table is a rollforward of PCI loans, net of the allowance for loan losses, for the years ended December 31, 2016 and 2015 . (in thousands) Contractual Cashflows Non-accretable Difference Accretable Yield Carrying Amount Balance January 1, 2016 $ 116,689 $ 26,765 $ 25,341 $ 64,583 Principal reductions and interest payments (25,669 ) — — (25,669 ) Accretion of loan discount — — (6,155 ) 6,155 Changes in contractual and expected cash flows due to remeasurement 11,718 766 (1,500 ) 12,452 Reductions due to disposals (36,735 ) (8,629 ) (4,510 ) (23,596 ) Balance December 31, 2016 $ 66,003 $ 18,902 $ 13,176 $ 33,925 Balance January 1, 2015 $ 178,145 $ 65,719 $ 28,733 $ 83,693 Principal reductions and interest payments (24,441 ) — — (24,441 ) Accretion of loan discount — — (10,775 ) 10,775 Changes in contractual and expected cash flows due to remeasurement (3,574 ) (30,413 ) 12,132 14,707 Reductions due to disposals (33,441 ) (8,541 ) (4,749 ) (20,151 ) Balance December 31, 2015 $ 116,689 $ 26,765 $ 25,341 $ 64,583 The accretable yield is accreted into interest income over the estimated life of the acquired loans using the effective yield method. A summary of activity in the FDIC loss share receivable for the year ended December 31, 2015 is as follows: (in thousands) December 31, 2015 Balance at beginning of period $ 15,866 Adjustments not reflected in income: Cash received from the FDIC for covered assets (3,528 ) FDIC reimbursable recoveries (1,386 ) Reductions for loss share termination (5,922 ) Adjustments reflected in income: Amortization, net (2,293 ) Loan impairment reversal (1,113 ) Reductions for payments on covered assets in excess of expected cash flows (1,624 ) Balance at end of period $ — Outstanding customer balances on PCI loans were $54.6 million and $98.6 million as of December 31, 2016 , and December 31, 2015 , respectively. On December 7, 2015, the Company entered into an agreement to terminate all existing loss share agreements with the FDIC. Under the terms of the agreement, the FDIC made a net payment to the bank of $1.3 million . The agreement eliminated the FDIC clawback liability of $3.5 million and the FDIC loss share receivable of $7.2 million . Accordingly, a one-time pretax charge of $2.4 million was recorded in 2015 as a separate component of noninterest expense, which was entirely earned back in the first quarter of 2016. See FDIC Loss Share Receivable and Clawback Liability in Note 1 – Summary of Significant Accounting Policies for information on the Company's accounting in prior years.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2016
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. Using derivative instruments can involve assuming counterparty credit risk to varying degrees. Counterparty credit risk relates to the loss the Company could incur if a counterparty were to default on a derivative contract. Notional amounts of derivative financial instruments do not represent credit risk, and are not recorded in the consolidated balance sheet. The overall credit risk and exposure to individual counterparties is monitored. The Company does not anticipate nonperformance by any counterparties. The amount of counterparty credit exposure is the unrealized gains in excess of collateral pledged, if any, on such derivative contracts along with the value of foreign exchange forward contracts. At December 31, 2016 , the Company had $1.0 million of counterparty credit exposure on derivatives. This counterparty risk is considered as part of underwriting and on-going monitoring policies. At December 31, 2016 and 2015 , the Company had pledged cash of $0.7 million and $1.3 million , respectively, as collateral in connection with interest rate swap agreements. Risk Management Instruments . The Company enters into interest rate caps in order to economically hedge changes in fair value of state tax credits held for sale. See Note 19 – Fair Value Measurements for further discussion of the fair value of the state tax credits. The notional amount of the derivative instruments used to manage risk was $3.5 million at December 31, 2016 and 2015 . 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 balance sheet. 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) December 31, December 31, December 31, December 31, December 31, December 31, Non-designated hedging instruments Interest rate swap contracts $ 124,322 $ 153,630 $ 982 $ 1,155 $ 982 $ 1,155 Foreign exchange forward contracts 3,034 — 3,034 — 3,034 — Changes in the fair value of client-related derivative instruments are recognized currently in operations. For the years ended December 31, 2016 and 2015 , the gains and losses offset each other due to the Company's hedging of the client swaps with other bank counterparties.

Fixed Assets

Fixed Assets	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Fixed Assets	FIXED ASSETS A summary of fixed assets at December 31, 2016 and 2015 , is as follows: December 31, (in thousands) 2016 2015 Land $ 3,103 $ 3,103 Buildings and leasehold improvements 18,054 17,837 Furniture, fixtures and equipment 6,136 4,892 Capitalized software 1,305 1,030 28,598 26,862 Less accumulated depreciation and amortization 13,688 12,020 Total fixed assets $ 14,910 $ 14,842 Depreciation and amortization of fixed assets included in noninterest expense amounted to $2.4 million , $2.0 million , and $2.2 million in 2016 , 2015 , and 2014 , respectively. The Company has facilities leased under agreements that expire in various years through 2028 . The Company's rent expense totaled $3.1 million , $3.1 million , and $2.9 million in 2016 , 2015 , and 2014 , respectively. Sublease rental income was $0.1 million , $0.1 million , and $0.2 million for 2016 , 2015 , and 2014 , respectively. For leases which renew or are subject to periodic rental adjustments, the monthly rental payments will be adjusted based on current market conditions and rates of inflation. The future aggregate minimum rental commitments (in thousands) required under the leases are shown below: Year Amount 2017 $ 2,797 2018 2,684 2019 2,676 2020 2,637 2021 2,642 Thereafter 6,667 Total $ 20,103 The Company has recorded a liability and corresponding expense for the difference between the net present value of future lease payments and its estimated sublease income on certain vacant branches. As of December 31, 2016 , this liability was $1.1 million . The Company recorded expense for the estimated net lease liability of $0.5 million , $0.1 million , and $0.4 million in 2016 , 2015 , and 2014 , respectively. The expense is recorded within other noninterest expense.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	GOODWILL AND INTANGIBLE ASSETS Goodwill has remained at $30.3 million as of December 31, 2016 , 2015 , and 2014 . The annual goodwill impairment evaluations in 2016 , 2015 , and 2014 did not identify any impairment. The table below presents a summary of intangible assets: (in thousands) Years ended December 31, 2016 2015 Gross core deposit intangible balance, beginning of year $ 9,060 $ 9,060 Accumulated amortization (6,909 ) (5,985 ) Core deposit intangible, net, end of year $ 2,151 $ 3,075 Amortization expense on the core deposit intangibles was $0.9 million , $1.1 million , and $1.3 million for the years ended December 31, 2016 , 2015 , and 2014 , respectively. The core deposit intangibles are being amortized over a 10 year period. The following table reflects the expected amortization schedule for the core deposit intangible (in thousands) at December 31, 2016 . Year Core Deposit Intangible 2017 $ 760 2018 595 2019 430 2020 265 After 2020 101 $ 2,151

Maturity of Certificates of Dep

Maturity of Certificates of Deposit	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Maturity of Certificates of Deposit	MATURITY OF CERTIFICATES OF DEPOSIT Following is a summary of certificates of deposit maturities at December 31, 2016 : (in thousands) Brokered Other Total Less than 1 year $ 117,145 $ 197,262 $ 314,407 Greater than 1 year and less than 2 years — 67,909 67,909 Greater than 2 years and less than 3 years — 28,806 28,806 Greater than 3 years and less than 4 years — 45,341 45,341 Greater than 4 years and less than 5 years — 16,696 16,696 $ 117,145 $ 356,014 $ 473,159 In 2016, the Company changed its presentation of certificates of deposit on the Consolidated Balance Sheets to separate brokered deposit sources from other sources. The corresponding prior period balances were reclassified to conform to the current year presentation. Certificates of deposit balances over the FDIC insurance limit of $250,000 were $124.8 million as of December 31, 2016 .

Subordinated Debentures

Subordinated Debentures	12 Months Ended
	Dec. 31, 2016
Brokers and Dealers [Abstract]
Subordinated Debentures	SUBORDINATED DEBENTURES The amounts and terms of each issuance of the Company's subordinated debentures at December 31, 2016 and 2015 were as follows: Amount Maturity Date Call Date Interest Rate (in thousands) 2016 2015 EFSC Clayco Statutory Trust I $ 3,196 $ 3,196 December 17, 2033 December 17, 2008 Floats 3MO LIBOR + 2.85% EFSC Capital Trust II 5,155 5,155 June 17, 2034 June 17, 2009 Floats 3MO LIBOR + 2.65% EFSC Statutory Trust III 11,341 11,341 December 15, 2034 December 15, 2009 Floats 3MO LIBOR + 1.97% EFSC Clayco Statutory Trust II 4,124 4,124 September 15, 2035 September 15, 2010 Floats 3MO LIBOR + 1.83% EFSC Statutory Trust IV 10,310 10,310 December 15, 2035 December 15, 2010 Floats 3MO LIBOR + 1.44% EFSC Statutory Trust V 4,124 4,124 September 15, 2036 September 15, 2011 Floats 3MO LIBOR + 1.60% EFSC Capital Trust VI 14,433 14,433 March 30, 2037 March 30, 2012 Floats 3MO LIBOR + 1.60% EFSC Capital Trust VII 4,124 4,124 December 15, 2037 December 15, 2012 Floats 3MO LIBOR + 2.25% Total trust preferred securities 56,807 56,807 Fixed-to-floating rate subordinated notes 50,000 — November 1, 2026 November 1, 2021 Fixed 4.75% until Less: Debt issuance costs (1,267 ) — Total fixed-to-floating rate subordinated notes 48,733 — Total subordinated debentures and notes $ 105,540 $ 56,807 The Company currently has eight unconsolidated statutory business trusts. These trusts issued preferred securities that were sold to third parties. The sole purpose of the trusts was to invest the proceeds in junior subordinated debentures of the Company that have terms identical to the trust preferred securities. The subordinated debentures, which are the sole assets of the trusts, are subordinate and junior in right of payment to all present and future senior and subordinated indebtedness and certain other financial conditions of the Company. The Company fully and unconditionally guarantees each trust's securities obligations. Under current regulations, the trust preferred securities are included in tier 1 capital for regulatory capital purposes, subject to certain limitations. The trust preferred securities are redeemable in whole or in part on or after their respective call dates. Mandatory redemption dates may be shortened if certain conditions are met. The securities are classified as subordinated debentures in the Company's consolidated balance sheets. Interest on the subordinated debentures held by the trusts is recorded as interest expense in the Company's consolidated statements of operations. The Company's investment of $1.7 million at December 31, 2016 , in these trusts is included in other investments in the consolidated balance sheets. On November 1, 2016 , the Company issued $50 million of fixed-to-floating rate subordinated notes. The notes initially bear a fixed annual interest rate of 4.75%, with interest payable semiannually in arrears on May 1 and November 1 of each year, commencing May 1, 2017. Commencing November 1, 2021 , the interest rate on the notes resets quarterly to the three-month LIBOR rate plus a spread of 338.7 basis points, payable quarterly in arrears. On or after November 1, 2021, the Company will have the option to redeem the notes, in whole or in part, at a redemption price equal to 100% of the principal amount of the subordinated notes to be redeemed plus accrued interest, subject to applicable regulatory approval. The Company’s obligation to make payments of principal and interest on the notes is subordinate and junior in right of payment to all of its senior debt. Current regulatory guidance allows for this subordinated debt to be treated as tier 2 regulatory capital for the first five years of its term, subject to certain limitations, and then phased out of tier 2 capital pro rata over the next five years.

Federal Home Loan Bank Advances

Federal Home Loan Bank Advances	12 Months Ended
	Dec. 31, 2016
Investments in and Advances to Affiliates, Schedule of Investments [Abstract]
Federal Home Loan Bank Advances	FEDERAL HOME LOAN BANK ADVANCES FHLB advances are collateralized by 1-4 family residential real estate loans, business loans and certain commercial real estate loans. At December 31, 2016 and 2015 , the carrying value of the loans pledged to the FHLB of Des Moines was $773.5 million and $633.5 million , respectively. The secured line of credit had availability of approximately $439.7 million at December 31, 2016 . The Company also has an $4.4 million investment in the capital stock of the FHLB of Des Moines at December 31, 2016 . The following table summarizes the type, maturity, and rate of the Company's FHLB advances at December 31: 2016 2015 ($ in thousands) Term Outstanding Balance Weighted Rate Outstanding Balance Weighted Rate Non-amortizing fixed advance Less than 1 year $ — — % $ 110,000 0.45 % Non-amortizing fixed advance Greater than 1 year — — % — — % Total Federal Home Loan Bank Advances $ — — % $ 110,000 0.45 % In December 2014, the Company prepaid $50 million of FHLB advances with a weighted average interest rate of 3.17% , and a maturity of 3 years, and incurred a prepayment penalty of $2.9 million for asset/liability management purposes. At December 31, 2016 , the Company used $26.7 million of collateral value to secure confirming letters of credit for public unit deposits and industrial development bonds.

Other Borrowings and Notes Paya

Other Borrowings and Notes Payable	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Other Borrowings and Notes Payable	OTHER BORROWINGS AND NOTES PAYABLE A summary of other borrowings is as follows: December 31, ($ in thousands) 2016 2015 Securities sold under repurchase agreements $ 276,980 $ 270,326 Average balance during the year $ 206,643 $ 195,328 Maximum balance outstanding at any month-end 276,980 270,326 Average interest rate during the year 0.19 % 0.22 % Average interest rate at December 31 0.18 % 0.16 % Federal Reserve Line The Bank also has a line with the Federal Reserve Bank of St. Louis which provides additional liquidity to the Company. As of December 31, 2016 , $933.9 million was available under this line. This line is secured by a pledge of certain eligible loans aggregating $1.1 billion . There were no amounts drawn on the Federal Reserve line of credit as of December 31, 2016 . Term Loan On November 6, 2012, the Company entered into a $12.0 million unsecured term loan agreement ("Term Loan") with another bank with the proceeds being used to redeem the Company's preferred stock held by the U.S. Treasury. The Term Loan was paid off on November 6, 2015, the maturity date of the loan. A summary of the Term Loan is as follows: ($ in thousands) December 31, 2015 Term Loan $ — Average balance during the year $ 4,509 Maximum balance outstanding at any month-end 5,700 Weighted average interest rate during the year 3.01 % Average interest rate at December 31 — % Revolving Credit In February 2016 , the Company entered into a senior unsecured revolving credit agreement ("Revolving Agreement") with another bank allowing for borrowings up to $20 million . The proceeds can be used for general corporate purposes. The Revolving Agreement is subject to ongoing compliance with a number of customary affirmative and negative covenants as well as specified financial covenants. There were no amounts drawn on the Revolving Agreement during 2016 .

Litigation and Other Contingenc

Litigation and Other Contingencies	12 Months Ended
	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Litigation and Other Contingencies	LITIGATION AND OTHER CONTINGENCIES The Company and its subsidiaries are, from time to time, parties to various legal proceedings arising out of their businesses. Management believes that 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.

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2016
Regulated Operations [Abstract]
Regulatory Matters	REGULATORY MATTERS Quantitative measures established by regulation to ensure capital adequacy require the Bank to maintain minimum amounts and ratios (set forth in the following table) of total, tier 1, and common equity tier 1 capital to risk-weighted assets, and of tier 1 capital to average assets. Management believes, as of December 31, 2016 and 2015 , that the Company met all capital adequacy requirements to which it is subject. As of December 31, 2016 and 2015 , the Bank was categorized as “well capitalized” under the regulatory framework for prompt corrective action. To be categorized as “well capitalized” the Bank must maintain minimum total risk-based capital, tier 1 risk-based capital, common equity tier 1 risk-based capital, and tier 1 leverage ratios as set forth in the table. The actual capital amounts and ratios are presented in the table below: Actual For Capital Adequacy Purposes To Be Well Capitalized Under Applicable Action Provisions ($ in thousands) Amount Ratio Amount Ratio Amount Ratio As of December 31, 2016: Total Capital (to Risk Weighted Assets) Enterprise Financial Services Corp $ 506,349 13.48 % $ 300,573 8.00 % $ — — % Enterprise Bank & Trust 430,981 11.53 298,982 8.00 373,728 10.00 Tier 1 Capital (to Risk Weighted Assets) Enterprise Financial Services Corp 412,865 10.99 225,430 6.00 — — Enterprise Bank & Trust 387,497 10.37 224,237 6.00 298,982 8.00 Common Equity Tier 1 Capital (to Risk Weighted Assets) 1 Enterprise Financial Services Corp 357,729 9.52 169,072 4.50 — — Enterprise Bank & Trust 387,461 10.37 168,178 4.50 242,923 6.50 Leverage Ratio (Tier 1 Capital to Average Assets) Enterprise Financial Services Corp 412,865 10.42 158,480 4.00 — — Enterprise Bank & Trust 387,497 9.81 157,933 4.00 197,417 5.00 As of December 31, 2015: Total Capital (to Risk Weighted Assets) Enterprise Financial Services Corp $ 418,367 11.85 % $ 282,442 8.00 % $ — — % Enterprise Bank & Trust 386,531 10.98 281,632 8.00 352,040 10.00 Tier 1 Capital (to Risk Weighted Assets) Enterprise Financial Services Corp 374,676 10.61 211,831 6.00 — — Enterprise Bank & Trust 342,840 9.74 211,224 6.00 281,632 8.00 Common Equity Tier 1 Capital (to Risk Weighted Assets) 1 Enterprise Financial Services Corp 319,553 9.05 158,873 4.50 — — Enterprise Bank & Trust 342,816 9.74 158,418 4.50 228,826 6.50 Leverage Ratio (Tier 1 Capital to Average Assets) Enterprise Financial Services Corp 374,676 10.71 139,893 4.00 — — Enterprise Bank & Trust 342,840 9.84 139,311 4.00 174,138 5.00 1 Not an applicable regulatory ratio until implementation of Basel III in 2015

Compensation Plans

Compensation Plans	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Compensation Plans	COMPENSATION PLANS The Company has adopted share-based compensation plans to reward and provide long-term incentive for directors and key employees of the Company. These plans provide for the granting of stock, stock options, stock-settled stock appreciation rights ("SSARs"), and restricted stock units (“RSUs”), as designated by the Company's Board of Directors upon the recommendation of the Compensation Committee of the Board. The Company uses authorized and unissued shares to satisfy share award exercises. At December 31, 2016 , there were 218,173 shares available for grant under the various share-based compensation plans. Total share-based compensation expense that was charged against income was $3.4 million , $3.6 million , and $2.9 million for the years ended December 31, 2016 , 2015 , and 2014 respectively. The total income tax benefit recognized in additional paid in capital for share-based compensation arrangements was $1.3 million , $0.4 million , and $0.2 million for the years ended December 31, 2016 , 2015 , and 2014 , respectively. Employee Stock Options and Stock-settled Stock Appreciation Rights In determining compensation cost for stock options and SSARs, the Black-Scholes option-pricing model is used to estimate the fair value on date of grant. There were no grants of employee stock options or SSARs during the years ended December 31, 2016 , 2015 , or 2014 . Stock options have been granted to key employees with exercise prices equal to the market price of the Company's common stock at the date of grant and 10 -year contractual terms. Stock options have a vesting schedule of three to five years. The SSARs are subject to continued employment, have a 10 -year contractual term and vest ratably over five years. Neither stock options nor SSARs carry voting or dividend rights until exercised. At December 31, 2016 , there was no remaining unrecognized compensation expense related to stock options and SSARs and all outstanding awards are vested. Various information related to the stock options and SSARs is shown below. (in thousands) 2016 2015 2014 Compensation expense $ — $ 50 $ 103 Intrinsic value of option exercises on date of exercise 1,156 74 226 Cash received from the exercise of stock options 87 126 149 Following is a summary of the employee stock option and SSAR activity for 2016 . (in thousands, except share and per share data) Shares Weighted Weighted Aggregate Outstanding at December 31, 2015 388,103 $ 19.15 Granted — — Exercised (117,857 ) 19.85 Forfeited — — Outstanding at December 31, 2016 270,246 $ 18.85 1.9 years $ 6,527 Exercisable at December 31, 2016 270,246 $ 18.85 1.9 years $ 6,527 Restricted Stock Units The Company awards nonvested stock, in the form of RSUs to employees and directors. RSUs generally are subject to continued employment and vest ratably over two to five years. Vesting is accelerated upon a change in control or the employee meeting certain retirement criteria. RSUs do not carry voting or dividend rights until vested. Sales of the units are restricted prior to vesting. Various information related to the RSUs is shown below. ($ in thousands) 2016 2015 2014 Compensation expense $ 850 $ 725 $ 945 Total fair value at vesting date 2,275 809 913 Total unrecognized compensation cost for nonvested stock units 1,084 942 1,462 Expected years to recognize unearned compensation 1.6 years 1.7 years 2.7 years A summary of the status of the Company's RSU awards as of December 31, 2016 and changes during the year then ended is presented below. Shares Weighted Average Grant Date Fair Value Outstanding at December 31, 2015 86,354 $ 14.31 Granted 32,913 29.71 Vested (56,089 ) 14.25 Forfeited (4,480 ) 13.51 Outstanding at December 31, 2016 58,698 $ 23.06 Stock Plan for Non-Management Directors The Company has adopted a Stock Plan for Non-Management Directors, which provides for issuing up to 200,000 shares of common stock to non-management directors as compensation in lieu of cash. At December 31, 2016 , there were 29,694 shares of stock available for issuance under the Stock Plan for Non-Management Directors. Various information related to the Director Plan is shown below. (in thousands, except share and per share data) 2016 2015 2014 Shares issued 12,528 16,283 23,135 Weighted average fair value $ 31.25 $ 24.43 $ 19.20 Compensation expense 407 373 329 Employee Stock Issuance Restricted stock was issued to certain key employees as part of their compensation. The restricted stock may be in the form of a one-time award or paid in pro rata installments. The stock is restricted for at least 2 years and upon issuance may be fully vested or vest over 5 years . The Company recognized zero , $0.2 million , and $0.1 million of stock-based compensation expense for the shares issued to the employees in 2016 , 2015 , and 2014 , respectively. The Company issued zero , 14,110 , and 34,034 shares in 2016 , 2015 , and 2014 , respectively. Long-term incentives The Company has entered into long-term incentive agreements with certain key employees. These awards are conditioned on certain performance criteria and market criteria measured against a group of peer banks over a 3 year period for each grant. The awards contain minimum (threshold), target, and maximum (exceptional) performance levels. In the event of a change in control, as defined in the plan, the awards will vest at a minimum of the target level. The amount of the awards are determined at the end of the 3 year vesting and performance period. In February 2017, the Company awarded 118,519 shares to employees upon completion of the 2014-2016 performance cycle. In January 2016, the Company awarded 159,094 shares to employees upon completion of the 2013-2015 performance cycle. In February 2015, the Company awarded 122,470 shares to employees upon completion of the 2012-2014 performance cycle. Information related to the outstanding grants at December 31, 2016 is shown below: (in thousands, except share and per share data) 2015 - 2017 Cycle 2016 - 2018 Cycle Shares issuable at target 113,903 95,694 Maximum shares issuable 142,292 117,681 Unrecognized compensation cost $ 1,140 $ 1,929 Weighted average grant date fair value 19.21 25.26 The Company recorded $2.5 million , $2.7 million and $1.8 million of stock-based compensation expense for these awards during 2016 , 2015 and 2014 , respectively. In 2016, this expense included an additional $0.2 million related to modifications made for retiring executives. The modification allows for portions of outstanding performance awards to continue to vest as though employment had not terminated and will be paid based on actual performance as determined by the compensation committee following completion of the applicable performance period. 401(k) plans The Company has a 401(k) savings plan which covers substantially all full-time employees over the age of 21 . The amount charged to expense for the Company's contributions to the plan was $1.7 million , $1.6 million and $1.4 million for 2016 , 2015 , and 2014 , respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The components of income tax expense for the years ended December 31 are as follows: Years ended December 31, (in thousands) 2016 2015 2014 Current: Federal $ 17,005 $ 22,916 $ 9,399 State and local 1,734 2,798 195 Total current 18,739 25,714 9,594 Deferred: Federal 5,959 (5,266 ) 3,908 State and local 1,304 (497 ) 369 Total deferred 7,263 (5,763 ) 4,277 Total income tax expense $ 26,002 $ 19,951 $ 13,871 A reconciliation of expected income tax expense, computed by applying the statutory federal income tax rate of 35% in 2016 , 2015 , and 2014 to income before income taxes and the amounts reflected in the consolidated statements of operations is as follows: Years ended December 31, (in thousands) 2016 2015 2014 Income tax expense at statutory rate $ 26,194 $ 20,440 $ 14,365 Increase (reduction) in income tax resulting from: Tax-exempt income, net (945 ) (931 ) (857 ) State and local income taxes, net 1,673 1,414 741 Bank-owned life insurance, net (544 ) (462 ) (535 ) Non-deductible expenses 263 259 290 Change in estimated rate for deferred taxes 302 — — Tax benefits of LIHTC investments, net (181 ) (179 ) (158 ) Other, net (760 ) (590 ) 25 Total income tax expense $ 26,002 $ 19,951 $ 13,871 The amount of tax credits and other tax benefits from low-income housing tax credit ("LIHTC") investments recognized during the year were $1.1 million during each of the years ended December 31, 2016 , 2015 , and 2014 . The amount recognized as a component of income tax expense per the table above was $0.3 million for the years ended December 31, 2016 and 2015 , and $0.2 million for the year ended December 31, 2014 . As of December 31, 2016 and 2015 , the carrying value of the investments related to low-income housing tax credits was $1.4 million and $2.3 million , respectively. No impairment losses have been recognized from forfeiture or ineligibility of tax credits or other circumstances during the life of any of the investments. As of December 31, 2016 , the Company has future capital commitments of $0.1 million related to low-income housing tax credit investments. The capital commitments are expected to be called between the years 2017 - 2024. A net deferred income tax asset of $33.8 million and $38.5 million is included in other assets in the consolidated balance sheets at December 31, 2016 and 2015 , respectively. The tax effect of temporary differences that gave rise to significant portions of the deferred tax assets and deferred tax liabilities is as follows: Years ended December 31, (in thousands) 2016 2015 Deferred tax assets: Allowance for loan losses $ 16,496 $ 16,705 Basis difference on PCI assets, net 5,551 8,806 Basis difference on Other real estate 317 328 Deferred compensation 4,217 4,509 Goodwill and other intangible assets 5,520 6,973 Accrued compensation 899 2,222 Unrealized losses on securities available for sale 1,019 — Other, net 925 907 Total deferred tax assets 34,944 40,450 Deferred tax liabilities: Unrealized gains on securities available for sale — 183 State tax credits held for sale, net of economic hedge 376 594 Core deposit intangibles 817 1,178 Total deferred tax liabilities 1,193 1,955 Net deferred tax asset $ 33,751 $ 38,495 A valuation allowance is provided on deferred tax assets when it is more likely than not that some portion of the assets will not be realized. The Company did not have any valuation allowances for federal or state income taxes as of December 31, 2016 or 2015 . The Company and its subsidiaries file income tax returns in the federal jurisdiction and in nine states. The Company is no longer subject to federal, state or local income tax audits by tax authorities for years before 2013, with the exception of 2012 being an open year by one state taxing authority. The Company is not currently under audit by any taxing jurisdiction. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense and classifies such interest and penalties in the liability for unrecognized tax benefits. The amounts accrued for interest and penalties as of December 31, 2016 , 2015 , and 2014 were not significant. As of December 31, 2016 , the gross amount of unrecognized tax benefits was $1.2 million and the total amount of net unrecognized tax benefits that would impact the effective tax rate, if recognized, was $0.8 million . As of December 31, 2015 and 2014 , the total amount of the net unrecognized tax benefits that would impact the effective tax rate, if recognized, was $0.9 million and $1.3 million , respectively. The Company believes it is reasonably possible that the gross amount of unrecognized benefits will be reduced by approximately $0.3 million as a result of a lapse of statute of limitations in the next 12 months. The activity in the gross liability for unrecognized tax benefits was as follows: (in thousands) 2016 2015 2014 Balance at beginning of year $ 1,359 $ 1,884 $ 1,257 Additions based on tax positions related to the current year 239 230 401 Additions for tax positions of prior years 39 46 523 Reductions for tax positions of prior years — (437 ) — Settlements or lapse of statute of limitations (457 ) (364 ) (297 ) Balance at end of year $ 1,180 $ 1,359 $ 1,884

Commitments

Commitments	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments	COMMITMENTS The Company issues financial instruments 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 not more than 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. The contractual amounts of off-balance-sheet financial instruments as of December 31, 2016 , and December 31, 2015 , are as follows: (in thousands) December 31, 2016 December 31, 2015 Commitments to extend credit $ 1,075,170 $ 1,140,028 Letters of credit 78,954 54,648 There was an insignificant amount of unadvanced commitments on impaired loans at December 31, 2016 and December 31, 2015 . Other liabilities include approximately $0.3 million for estimated losses attributable to the unadvanced commitments. 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 December 31, 2016 , and December 31, 2015 , $89.7 million and $93.9 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 obligations. 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. Letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. These 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. The approximate remaining term of letters of credit range from 1 month to 4 years and 9 months at December 31, 2016 .

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The fair value of an asset or liability is the price that would be received to sell that asset or paid to transfer that liability in an orderly transaction occurring in the principal market (or most advantageous market in the absence of a principal market) for such asset or liability. In estimating fair value, the Company utilizes valuation techniques that are consistent with the market approach, the income approach and/or the cost approach. Such valuation techniques are consistently applied. Inputs to valuation techniques include the assumptions that market participants would use in pricing an asset or liability. ASC Topic 820, Fair Value Measurements and Disclosures, establishes a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The fair value hierarchy is as follows: • Level 1 Inputs - Unadjusted quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. • Level 2 Inputs - Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These might include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, volatilities, prepayment speeds, credit risks, etc.) or inputs that are derived principally from or corroborated by market data by correlation or other means. • Level 3 Inputs - Unobservable inputs for determining the fair values of assets or liabilities that reflect an entity's own assumptions about the assumptions that market participants would use in pricing the assets or liabilities. Fair value on a recurring basis The following table summarizes financial instruments measured at fair value on a recurring basis as of December 31, 2016 and 2015 , segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value. 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 December 31, 2015 (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 $ — $ 99,008 $ — $ 99,008 Obligations of states and political subdivisions — 38,624 3,077 41,701 Residential mortgage-backed securities — 311,061 — 311,061 Total securities available for sale — 448,693 3,077 451,770 State tax credits held for sale — — 5,941 5,941 Derivative financial instruments — 1,155 — 1,155 Total assets $ — $ 449,848 $ 9,018 $ 458,866 Liabilities Derivative financial instruments $ — $ 1,155 $ — $ 1,155 Total liabilities $ — $ 1,155 $ — $ 1,155 • Securities available for sale . Securities classified as available for sale are reported at fair value utilizing Level 2 and Level 3 inputs. Fair values for Level 2 securities are based upon dealer quotes, market spreads, the U.S. Treasury yield curve, trade execution data, market consensus prepayment speeds, credit information and the bond's terms and conditions at the security level. At December 31, 2016 , 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 December 31, 2016 , of the $38.1 million of state tax credits held for sale on the consolidated balance sheet, approximately $3.6 million were carried at fair value. The remaining $34.5 million of state tax credits were accounted for at cost. The Company elected not to account for the state tax credits purchased since 2010 at fair value in order to limit the volatility of the fair value changes in our consolidated statements of operations. 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. Economically, the Company equates the state tax credits to a fixed rate loan. After considering various risks, such as credit risk, compliance risk, and recapture risk, management concluded the state tax credits are equivalent to a fixed rate loan priced at Prime minus 75 basis points. When pricing a fixed rate loan, most banks utilize the Prime-based swap curve, which is based on the LIBOR swap curve plus a prime equivalent spread of 265 to 285 basis points depending on market pricing and the maturity of the underlying loan. The Prime-based swap curve is available daily on Bloomberg or other national pricing services. As a result, at December 31, 2016 and 2015 , management concluded the spread of 205 basis points to the LIBOR curve should be utilized in the fair value calculation. At December 31, 2016 , the discount rates utilized in our state tax credits fair value calculation ranged from 3.05% to 3.50% . Resulting changes in the fair value of the state tax credits held for sale decreased Gain on state tax credits, net in the consolidated statement of operations by $0.6 million for the year ended December 31, 2016 . • Derivatives . Derivatives are reported at fair value utilizing Level 2 inputs. The Company obtains counterparty quotations to value its interest rate swaps and caps. 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 December 31, 2016 and 2015 . • Purchases, sales, issuances and settlements . There were no Level 3 purchases during the year ended December 31, 2016 . • Transfers in and/or out of Level 3 . There were no transfers in and/or out of Level 3 for the years ending December 31, 2016 and 2015 . Securities available for sale, at fair value Years ended December 31, (in thousands) 2016 2015 Beginning balance $ 3,077 $ 3,059 Total gains: Included in other comprehensive income 12 18 Purchases, sales, issuances and settlements — — Ending balance $ 3,089 $ 3,077 Change in unrealized gains relating to assets still held at the reporting date $ 12 $ 18 State tax credits held for sale, at fair value Years ended December 31, (in thousands) 2016 2015 Beginning balance $ 5,941 $ 11,689 Total gains: Included in earnings 177 406 Purchases, sales, issuances and settlements: Sales (2,533 ) (6,154 ) Ending balance $ 3,585 $ 5,941 Change in unrealized losses relating to assets still held at the reporting date $ (575 ) $ (1,212 ) Fair value on a non-recurring basis Certain financial assets and financial liabilities are measured at fair value on a non-recurring basis; that is, the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment). • Impaired loans . Impaired loans are included as Portfolio loans on the Company's consolidated balance sheets with amounts specifically reserved for credit impairment in the Allowance for loan losses. On a quarterly basis, fair value adjustments are recorded on impaired loans to account for (1) partial write-downs that are based on the current appraised or market-quoted value of the underlying collateral or (2) the full charge-off of the loan carrying value. In some cases, the properties for which market quotes or appraised values have been obtained are located in areas where comparable sales data is limited, outdated, or unavailable. In addition, the Company may adjust the valuations based on other relevant market conditions or information. Accordingly, fair value estimates, including those obtained from real estate brokers or other third-party consultants, for collateral-dependent impaired loans are classified in Level 3 of the valuation hierarchy. • Other Real Estate. These assets are reported at the lower of the loan carrying amount at foreclosure or fair value. Fair value is based on third party appraisals of each property and the Company's judgment of other relevant market conditions. These are considered Level 3 inputs. The following table presents financial instruments and non-financial assets measured at fair value on a non-recurring basis as of December 31, 2016 and 2015 . December 31, 2016 (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 year ended Impaired loans $ 175 $ — $ — $ 175 $ 4,335 Other real estate — — — — 1 Total $ 175 $ — $ — $ 175 $ 4,336 December 31, 2015 (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 year ended Impaired loans $ 2,561 $ — $ — $ 2,561 $ 6,091 Other real estate 753 — — 753 83 Total $ 3,314 $ — $ — $ 3,314 $ 6,174 (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. 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. Carrying amount and fair value at December 31, 2016 and 2015 Following is a summary of the carrying amounts and fair values of the Company’s financial instruments on the consolidated balance sheets at December 31, 2016 and 2015 . December 31, 2016 December 31, 2015 (in thousands) Carrying Amount Estimated fair value Carrying Amount Estimated fair value Balance sheet assets Cash and due from banks $ 54,288 $ 54,288 $ 47,935 $ 47,935 Federal funds sold 446 446 91 91 Interest-bearing deposits 145,048 145,048 47,131 47,131 Securities available for sale 460,797 460,797 451,770 451,770 Securities held to maturity 80,463 79,639 43,714 43,441 Other investments, at cost 14,840 14,840 17,455 17,455 Loans held for sale 9,562 9,562 6,598 6,598 Derivative financial instruments 4,016 4,016 1,155 1,155 Portfolio loans, net 3,114,752 3,125,701 2,781,879 2,782,704 State tax credits, held for sale 38,071 41,264 45,850 49,588 Accrued interest receivable 11,117 11,117 8,399 8,399 Balance sheet liabilities Deposits 3,233,361 3,232,414 2,784,591 2,784,654 Subordinated debentures and notes 105,540 86,052 56,807 35,432 Federal Home Loan Bank advances — — 110,000 109,994 Other borrowings 276,980 276,905 270,326 270,286 Derivative financial instruments 4,016 4,016 1,155 1,155 Accrued interest payable 1,105 1,105 629 629 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 on the consolidated balance sheets at fair value at December 31, 2016 , and December 31, 2015 . Estimated Fair Value Measurement at Reporting Date Using Balance at (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 Estimated Fair Value Measurement at Reporting Date Using Balance at (in thousands) Level 1 Level 2 Level 3 Financial Assets: Securities held to maturity $ — $ 43,441 $ — $ 43,441 Portfolio loans, net — — 2,782,704 2,782,704 State tax credits, held for sale — — 43,647 43,647 Financial Liabilities: Deposits 2,428,403 — 356,251 2,784,654 Subordinated debentures and notes — 35,432 — 35,432 Federal Home Loan Bank advances — 109,994 — 109,994 Other borrowings — 270,286 — 270,286 The following methods and assumptions were used to estimate the fair value of each class of financial instruments for which it is practical to estimate such value: Cash, Federal funds sold, and other short-term instruments For cash and due from banks, federal funds purchased, interest-bearing deposits, and accrued interest receivable (payable), the carrying amount is a reasonable estimate of fair value, as such instruments reprice in a short time period (Level 1). Securities available for sale and held to maturity The Company obtains fair value measurements for debt instruments from an independent pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond's terms and conditions (Level 2). Other investments Other investments, which primarily consists of membership stock in the FHLB, is reported at cost, which approximates fair value (Level 2). Loans held for sale These loans consist of mortgages that are sold on the secondary market generally within three months of origination. They are reported at cost, which approximates fair value (Level 2). Portfolio loans, net The fair value of adjustable-rate loans approximates cost. The fair value of fixed-rate loans is estimated by discounting the future cash flows using the current rates at which similar loans would be made to borrowers for the same remaining maturities. The fair value of the acquired loans are based on the present value of expected future cash flows (Level 3). The method of estimating fair value does not incorporate the exit-price concept of fair value prescribed by ASC Topic 820. State tax credits held for sale The fair value of state tax credits held for sale is calculated using an internal valuation model with unobservable market data as discussed in further detail above (Level 3). Derivative financial instruments The fair value of derivative financial instruments is based on quoted market prices by the counterparty and verified by the Company using public pricing information (Level 2). Deposits The fair value of demand deposits, interest-bearing transaction accounts, money market accounts and savings deposits is the amount payable on demand at the reporting date (Level 1). The fair value of fixed-maturity certificates of deposit is estimated by discounting the future cash flows using the rates currently offered for deposits of similar remaining maturities (Level 3). Subordinated debentures and notes Fair value of subordinated debentures and notes is based on discounting the future cash flows using rates currently offered for financial instruments of similar remaining maturities (Level 2). Federal Home Loan Bank advances The fair value of the FHLB advances is based on the discounted value of contractual cash flows. The discount rate is estimated using current rates on borrowed money with similar remaining maturities (Level 2). Other borrowed funds Other borrowed funds include customer repurchase agreements, federal funds purchased, notes payable, and secured borrowings related to loan participations. The fair value of federal funds purchased, customer repurchase agreements and notes payable are assumed to be equal to their carrying amount since they have an adjustable interest rate (Level 2). Commitments to extend credit and letters of credit The fair value of commitments to extend credit and letters of credit are estimated using the fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements, the likelihood of the counterparties drawing on such financial instruments, and the present creditworthiness of such counterparties (Level 2). The Company believes such commitments have been made on terms which are competitive in the markets in which it operates; however, no premium or discount is offered thereon and accordingly, the Company has not assigned a value to such instruments for purposes of this disclosure. Limitations Fair value estimates are made at a specific point in time, based on relevant market information and information about the financial instrument. These estimates are subjective in nature and involve uncertainties and matters of significant judgment, and therefore, cannot be determined with precision. Such estimates include the valuation of loans, goodwill, intangible assets, and other long-lived assets, along with assumptions used in the calculation of income taxes, among others. These estimates and assumptions are based on management's best estimates and judgment. Management evaluates its estimates and assumptions on an ongoing basis using experience and other factors, including the current economic environment, which management believes to be reasonable under the circumstances. We adjust such estimates and assumptions when facts and circumstances dictate. Decreasing real estate values, illiquid credit markets, volatile equity markets, and declines in consumer spending have combined to increase the uncertainty inherent in such estimates and assumptions. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Changes in estimates resulting from continuing changes in the economic environment will be reflected in the financial statement in future periods. In addition, these estimates do not reflect any premium or discount that could result from offering for sale at one time the Company's entire holdings of a particular financial instrument. Fair value estimates are based on existing on-balance and off-balance-sheet financial instruments without attempting to estimate the value of anticipated future business and the value of assets and liabilities that are not considered financial instruments. In addition, the tax ramifications related to the realization of the unrealized gains and losses can have a significant effect on fair value estimates and have not been considered in many of the estimates.

Parent Company Only Condensed F

Parent Company Only Condensed Financial Statements	12 Months Ended
	Dec. 31, 2016
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Parent Company Only Condensed Financial Statements	PARENT COMPANY ONLY CONDENSED FINANCIAL STATEMENTS Condensed Balance Sheets December 31, (in thousands) 2016 2015 Assets Cash $ 52,245 $ 12,032 Investment in Enterprise Bank & Trust 416,831 374,092 Investment in nonbank subsidiaries 2,798 1,510 Other assets 22,111 20,357 Total assets $ 493,985 $ 407,991 Liabilities and Shareholders' Equity Subordinated debentures and notes $ 105,540 $ 56,807 Accounts payable and other liabilities 1,347 355 Shareholders' equity 387,098 350,829 Total liabilities and shareholders' equity $ 493,985 $ 407,991 Condensed Statements of Operations Years ended December 31, (in thousands) 2016 2015 2014 Income: Dividends from subsidiaries $ 7,500 $ 10,000 $ 10,000 Other 491 249 225 Total income 7,991 10,249 10,225 Expenses: Interest expense-subordinated debentures and notes 1,893 1,248 1,322 Interest expense-notes payable 53 144 193 Other expenses 5,526 3,823 4,402 Total expenses 7,472 5,215 5,917 Income before taxes and equity in undistributed earnings of subsidiaries 519 5,034 4,308 Income tax benefit 2,583 2,118 2,305 Net income before equity in undistributed earnings of subsidiaries 3,102 7,152 6,613 Equity in undistributed earnings of subsidiaries 45,735 31,298 20,560 Net income and comprehensive income $ 48,837 $ 38,450 $ 27,173 Condensed Statements of Cash Flows Years Ended December 31, (in thousands) 2016 2015 2014 Cash flows from operating activities: Net income $ 48,837 $ 38,450 $ 27,173 Adjustments to reconcile net income to net cash provided by (used in) operating activities: Share-based compensation 3,367 3,601 2,950 Net income of subsidiaries (53,235 ) (41,298 ) (30,560 ) Dividends from subsidiaries 7,500 10,000 10,000 Excess tax expense of share-based compensation (1,327 ) (449 ) (205 ) Other, net 1,848 848 704 Net cash provided by operating activities 6,990 11,152 10,062 Cash flows from investing activities: Cash contributions to subsidiaries (250 ) — — Purchases of other investments (2,435 ) (2,832 ) (2,224 ) Proceeds from distributions on other investments 1,151 880 176 Net cash used by investing activities (1,534 ) (1,952 ) (2,048 ) Cash flows from financing activities: Proceeds from issuance of subordinated notes 48,733 — — Repayments of notes payable — (5,700 ) (4,800 ) Cash dividends paid (8,211 ) (5,259 ) (4,177 ) Excess tax benefit of share-based compensation 1,327 449 205 Payments for the repurchase of common stock (4,889 ) — — Issuance of common stock 2 2 2 Proceeds from the issuance of equity instruments, net (2,205 ) (1,192 ) (681 ) Net cash provided (used) by financing activities 34,757 (11,700 ) (9,451 ) Net increase (decrease) in cash and cash equivalents 40,213 (2,500 ) (1,437 ) Cash and cash equivalents, beginning of year 12,032 14,532 15,969 Cash and cash equivalents, end of year $ 52,245 $ 12,032 $ 14,532

Quarterly Condensed Financial I

Quarterly Condensed Financial Information	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Quarterly Condensed Financial Information	QUARTERLY CONDENSED FINANCIAL INFORMATION (Unaudited) The following table presents unaudited quarterly financial information for the periods indicated: 2016 (in thousands, except per share data) 4th Quarter 3rd Quarter 2nd Quarter 1st Quarter Interest income $ 39,438 $ 37,293 $ 37,033 $ 35,460 Interest expense 3,984 3,463 3,250 3,032 Net interest income 35,454 33,830 33,783 32,428 Provision for portfolio loan losses 964 3,038 716 833 Provision reversal for PCI loan losses (343 ) (1,194 ) (336 ) (73 ) Net interest income after provision for loan losses 34,833 31,986 33,403 31,668 Noninterest income 9,029 6,976 7,049 6,005 Noninterest expense 23,181 20,814 21,353 20,762 Income before income tax expense 20,681 18,148 19,099 16,911 Income tax expense 7,053 6,316 6,747 5,886 Net income $ 13,628 $ 11,832 $ 12,352 $ 11,025 Earnings per common share: Basic $ 0.68 $ 0.59 $ 0.62 $ 0.55 Diluted 0.67 0.59 0.61 0.54 2015 (in thousands, except per share data) 4th Quarter 3rd Quarter 2nd Quarter 1st Quarter Interest income $ 35,096 $ 33,180 $ 32,352 $ 32,151 Interest expense 3,017 3,174 3,072 3,106 Net interest income 32,079 30,006 29,280 29,045 Provision for portfolio loan losses 543 599 2,150 1,580 Provision reversal for PCI loan losses (917 ) (227 ) — (3,270 ) Net interest income after provision for loan losses 32,453 29,634 27,130 30,735 Noninterest income 6,557 4,729 5,806 3,583 Noninterest expense 22,886 19,932 19,458 19,950 Income before income tax expense 16,124 14,431 13,478 14,368 Income tax expense 5,445 4,722 4,762 5,022 Net income $ 10,679 $ 9,709 $ 8,716 $ 9,346 Earnings per common share: Basic $ 0.53 $ 0.49 $ 0.44 $ 0.47 Diluted 0.52 0.48 0.43 0.46

New Authoritative Accounting Gu

New Authoritative Accounting Guidance	12 Months Ended
	Dec. 31, 2016
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") 2017-04 "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 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 2016-09 "Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting" In March 2016, the FASB issued ASU 2016-09, "Compensation-Stock Compensation (Topic 718)" which impacts accounting for share-based payment transactions, including income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 requires all excess tax benefits and tax deficiencies to be recognized in the statement of operations as income tax expense (or benefit.) The tax effects of exercised or vested awards must be treated as discrete items in the reporting period in which they occur, regardless of whether the benefit reduces taxes payable in the current period. Excess tax benefits will be classified with other income tax cash flows as an operating activity, and cash paid by an employer when withholding shares for tax liabilities should be classified as a financing activity. The guidance became effective in the first quarter of 2017. The Company expects to reclassify approximately $5 million from additional paid in capital to retained earnings upon adoption. Also, excess tax benefits of share-based compensation will no longer be reclassified from operating activities to financing activities on the consolidated statement of cash flows. The Company has not completed its evaluation of the impact this standard will have on its statement of operations. 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.

Subsequent Events (Notes)

Subsequent Events (Notes)	12 Months Ended
	Dec. 31, 2016
Subsequent Event [Line Items]
Subsequent Events [Text Block]	SUBSEQUENT EVENTS On February 10, 2017 , the Company closed on its previously announced acquisition of Jefferson County Bancshares, Inc. (“JCB”) and JCB's wholly-owned subsidiary, Eagle Bank and Trust Company of Missouri. See Note 2 –Acquisitions for more information regarding the transaction.

Summary of Significant Accoun33

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Business and Consolidation	Enterprise Financial Services Corp and subsidiaries (the “Company” or “Enterprise”) is a financial holding company that provides a full range of banking and wealth management services to individuals and corporate customers primarily located in the St. Louis, Kansas City, and Phoenix metropolitan markets through its banking subsidiary, Enterprise Bank & Trust (the “Bank”). The 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. The Company is subject to competition from other financial and nonfinancial institutions providing financial services in the markets served by the Company's subsidiary. Additionally, the Company and its banking subsidiary are subject to the regulations of certain federal and state agencies and undergo periodic examinations by those regulatory agencies. The Company has one operating segment.
Use of Estimates	The consolidated financial statements of the Company have been prepared in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”.) In preparing the consolidated financial statements, management is required to make estimates and assumptions, which significantly affect the reported amounts in the consolidated financial statements. Such estimates include the valuation of loans, goodwill, intangible assets, indemnification assets, and other long-lived assets, along with assumptions used in the calculation of income taxes, among others. These estimates and assumptions are based on management's best estimates and judgment. Management evaluates its estimates and assumptions on an ongoing basis using experience and other factors, including the current economic environment, which management believes to be reasonable under the circumstances. Management adjusts such estimates and assumptions when facts and circumstances dictate. Decreased real estate values, volatile credit markets, and unemployment have combined to increase the uncertainty inherent in such estimates and assumptions. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Changes in those estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods.
Cash Flow Information	For purposes of reporting cash flows, the Company considers cash and due from banks, interest-bearing deposits and federal funds sold that mature within 90 days to be cash and cash equivalents.
Investments	The Company has classified all investments in debt securities as available for sale or held to maturity. Securities classified as available for sale are carried at fair value. Unrealized holding gains and losses for available for sale securities are excluded from earnings and reported as a net amount in a separate component of shareholders' equity until realized. All previous fair value adjustments included in the separate component of shareholders' equity are reversed upon sale. Securities classified as held to maturity are carried at historical cost and adjusted for amortization of premiums and accretion of discounts. Declines in the fair value of securities below their cost deemed to be other-than-temporary are reflected in operations as realized losses. In estimating other-than-temporary impairment losses, 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 (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's more likely than not the Company would be required to sell the security before its anticipated recovery in market value. Premiums and discounts are amortized or accreted over the expected lives of the respective securities as an adjustment to yield using the interest method. Dividend and interest income is recognized when earned. Realized gains and losses are included in earnings and are derived using the specific identification method for determining the cost of securities sold.
Loans Receivable	The Company provides long-term financing of one-to-four-family residential real estate by originating fixed and variable rate loans. Long-term fixed and variable rate loans are sold into the secondary market with limited recourse. Upon receipt of an application for a real estate loan, the Company determines whether the loan will be sold into the secondary market or retained in the Company's loan portfolio. The interest rates on the loans sold are locked with the buyer and the Company bears no interest rate risk related to these loans. Mortgage loans held for sale are carried at the lower of cost or fair value, which is determined on a specific identification method. The Company does not retain servicing on any loans sold, nor did the Company have any capitalized mortgage servicing rights at December 31, 2016 or 2015 . Gains on the sale of loans held for sale are reported net of direct origination fees and costs in the Company's consolidated statements of operations. Portfolio Loans Loans are reported at the principal balance outstanding, net of unearned fees, costs, and premiums or discounts on acquired loans. Loan origination fees, direct origination costs, and premiums or discounts resulting from acquired loans are deferred and recognized over the lives of the related loans as a yield adjustment using the interest method. Interest income on loans is accrued to income based on the principal amount outstanding. The recognition of interest income is discontinued when a loan becomes 90 days past due or a significant deterioration in the borrower's credit has occurred which, in management's judgment, negatively impacts the collectibility of the loan. Unpaid interest on such loans is reversed at the time the loan becomes uncollectible and subsequent interest payments received are applied to principal if any doubt exists as to the collectibility of such principal; otherwise, such receipts are recorded as interest income. Loans that have not been restructured are returned to accrual status when management believes full collectibility of principal and interest is expected. Non-accrual loans that have been restructured will remain in a non-accrual status until the borrower has made at least six months of consecutive contractual payments. Purchased Credit Impaired ("PCI") Loans Loans acquired through the completion of a transfer, including loans acquired in a business combination, that have evidence of deterioration of credit quality since origination and for which it is probable, at acquisition, that the Company will be unable to collect all contractually required payments receivable, are initially recorded at fair value (as determined by the present value of expected future cash flows) with no valuation allowance. The difference between the undiscounted cash flows expected at acquisition and the investment in the loans, or the “accretable yield,” is recognized as interest income on a level-yield method over the life of the loans. Contractually required payments for interest and principal that exceed the undiscounted cash flows expected at acquisition, or the “nonaccretable difference,” are not recognized as a yield adjustment or as a loss accrual or a valuation allowance. The Company aggregates individual loans with common risk characteristics into pools of loans. Increases in expected cash flows subsequent to the initial investment are recognized prospectively through adjustment of the yield on the loans over their remaining lives. Decreases in expected cash flows due to an inability to collect contractual cash flows are recognized as impairment through the provision for loan losses account. Any allowance for loan loss on these pools reflect only losses incurred after the acquisition (meaning the present value of all cash flows expected at acquisition that ultimately are not to be received). Any disposals of loans, including sales of loans, payments in full or foreclosures result in the removal of the loan from the loan pool at the carrying amount with differences in actual results reflected in interest income. Impaired Loans Loans are considered “impaired” when it becomes probable that the Company will be unable to collect all amounts due according to the loan's contractual terms. Non-accrual loans, loans past due greater than 90 days and still accruing, unless adequately secured and in the process of collection, and restructured loans qualify as “impaired loans.” Restructured loans involve the granting of a concession to a borrower experiencing financial difficulty involving the modification of terms of the loan, such as changes in payment schedule or interest rate. When measuring impairment, the expected future cash flows of an impaired loan are discounted at the loan's effective interest rate at origination. Alternatively, impairment can be measured by reference to an observable market price, if one exists, or the fair value of the collateral for a collateral-dependent loan. Interest income on impaired loans is not accrued but is recorded when cash is received and only if principal is considered to be fully collectible. Loans and leases, which are deemed uncollectible, are charged off to the allowance for loan losses, while recoveries of amounts previously charged off are credited to the allowance for loan losses. Impaired loans exclude PCI loans, which are accounted for on a pool basis and are generally considered accruing and performing loans, as the loans accrete interest income over the estimated life of the loan when cash flows are reasonably estimable. Accordingly, PCI loans that are contractually past due may still be considered to be accruing and performing loans. If the timing and amount of future cash flows is not reasonably estimable, the loans may be classified as nonaccrual loans and the purchase price discount on those loans is not recorded as interest income until the timing and amount of future cash flows can be reasonably estimated. See Note 6 – Purchased Credit Impaired Loans for more information on these loans. Loans are generally placed on non-accrual status when contractually past due 90 days or more as to interest or principal payments. Additionally, whenever management becomes aware of facts or circumstances that may adversely impact the collectability of principal or interest on loans, it is management's practice to place such loans on non-accrual status immediately, rather than delaying such action until the loans become 90 days past due. Previously accrued and uncollected interest on such loans is reversed. Income is recorded only to the extent that a determination has been made that the principal balance of the loan is collectable and the interest payments are subsequently received in cash, or for a restructured loan, the borrower has made six consecutive contractual payments. If collectability of the principal is in doubt, payments received are applied to loan principal. Loans past due 90 days or more but still accruing interest are also generally included in nonperforming loans. Loans past due 90 days or more but still accruing are classified as such where the underlying loans are both well secured (the collateral value is sufficient to cover principal and accrued interest) and are in the process of collection. At December 31, 2016 , we did not have any loans past due greater than 90 days and not included in nonperforming loans. Loan Charge-Offs Loans are charged-off when the primary and secondary sources of repayment (cash flow, collateral, guarantors, etc.) are less than their carrying value.
Allowance for Loan Losses	Allowance For Loan Losses The allowance for loan losses is increased by provision charged to expense and is available to absorb charge-offs, net of recoveries. Management utilizes a systematic, documented approach in determining the appropriate level of the allowance for loan losses. The level of the allowance reflects management's continuing evaluation of industry concentrations; specific credit risks; loan loss experience; current loan portfolio quality; present economic, political and regulatory conditions; and probable losses inherent in the current loan portfolio. The determination of the appropriate level of the allowance for loan losses inherently involves a degree of subjectivity and requires that the Company make significant estimates of current credit risks and future trends, all of which may undergo material changes. Changes in economic conditions affecting borrowers, new information regarding existing loans, identification of additional problem loans and other factors, both within and outside of our control, may require an increase in the allowance for loan losses. Management believes the allowance for loan losses is adequate to absorb inherent losses in the loan portfolio. While management uses available information to recognize losses on loans, future additions to the allowance may be necessary based on changes in economic conditions and other factors. In addition, various regulatory agencies, as an integral part of the examination process, periodically review the Bank's loan portfolio. Such agencies may require additions to the allowance for loan losses based on their judgments and interpretations of information available to them at the time of their examinations. Allowance for Loan Losses on PCI Loans The Company updates its cash flow projections for PCI loans on a periodic basis. Assumptions utilized in this process include projections related to probability of default, loss severity, prepayment, extensions and recovery lag. Projections related to probability of default and prepayment are calculated utilizing a loan migration analysis. The loan migration analysis is a matrix of probability that specifies the probability of a loan pool transitioning into a particular delinquency or liquidation state given its current state at the re-measurement date. Loss severity factors are based upon industry data and experience. Any decreases in expected cash flows after the acquisition date and subsequent measurement periods are recognized by recording an impairment in the provision for loan losses. See Purchased Credit Impaired Loans above for further discussion. Any increase in expected future cash flows due to a decrease in expected credit losses will reverse previously recorded impairment, if any, and add to the accretable yield on the loan pool, prospectively.
Other Real Estate	Other real estate represents property acquired through foreclosure or deeded to the Company in lieu of foreclosure on loans on which the borrowers have defaulted on the payment of principal or interest. Other real estate is recorded on an individual asset basis at the lower of cost or fair value less estimated costs to sell. The fair value of other real estate is based upon estimates of future cash flows, market value of similar assets, if available, or independent appraisals. These estimates involve significant uncertainties and judgments. As a result, fair value estimates may not be realizable in a current sale or settlement of the other real estate. Subsequent reductions in fair value are expensed within noninterest expense. Gains and losses resulting from the sale of other real estate are credited or charged to current period earnings. Costs of maintaining and operating other real estate are expensed as incurred, and expenditures to complete or improve other real estate properties are capitalized if the expenditures are expected to be recovered upon ultimate sale of the property.
FDIC Loss Share Receivable and Clawback Liability	As part of several FDIC-assisted transactions, the Bank entered into loss sharing agreements with the FDIC from 2009-2011. In 2015, the Bank entered into an agreement with the FDIC to terminate all existing loss sharing agreements. This termination resulted in the removal of the remaining clawback liability of $3.5 million and FDIC receivable of $7.2 million . The following policy discussion refers to transactions prior to December 7, 2015. The FDIC reimbursed the Bank for a percentage of realized losses on loans and foreclosed real estate covered under the agreement (“covered assets”). In addition, the Bank was reimbursed for certain expenses related to the covered assets. At the acquisition date, the fair value of the amount due from the FDIC (“FDIC Loss Share Receivable") was estimated based on expected losses and cash flows on the covered assets. The FDIC Loss Share Receivable was measured separately from the related covered assets and recorded separately on the balance sheet, because it is not contractually embedded in the covered assets and was not transferable. Although these assets are contractual receivables from the FDIC, there are no contractual interest rates. Subsequent to initial recognition, but prior to early termination in the fourth quarter of 2015, the FDIC Loss Share Receivable was reviewed quarterly and adjusted for any changes in expected cash flows. These adjustments were measured on the same basis as the related covered assets. Any decrease in expected cash flows due to an increase in expected credit losses increased the FDIC Loss Share Receivable which partially offset the impairment recorded on the PCI loans. The amount of the increase was recorded in noninterest income and was determined based on the specific loss share agreement, but was generally 80% of the losses. Any increase in expected future cash flows due to a decrease in expected credit losses decreased the accretion of the FDIC Loss Share Receivable prospectively over its remaining life. Increases and decreases to the FDIC Loss Share Receivable were recorded as adjustments to noninterest income. As stipulated in some of its agreements with the FDIC, the Company may have been required to reimburse the FDIC if certain levels of cash flows were met over the duration of a loss share agreement. This reimbursement, or clawback liability, was measured quarterly.
Fixed Assets	Buildings, leasehold improvements, furniture, fixtures, equipment, and capitalized software are stated at cost less accumulated depreciation. All categories are computed using the straight-line method over their respective estimated useful lives. Furniture, fixtures and equipment is depreciated over three to ten years, buildings and leasehold improvements over ten to forty years, and capitalized software over three years based upon estimated lives or lease obligation periods.
State Tax Credits Held for Sale	The Company has purchased the rights to receive 10 -year streams of state tax credits at agreed upon discount rates and sells such tax credits to its clients and others. All state tax credits purchased prior to 2009 are accounted for at fair value. All state tax credits purchased since 2009 are accounted for at cost. The Company elected not to account for the state tax credits purchased since 2009 at fair value in order to limit the volatility of the fair value changes in the Company's consolidated statements of operations.
Cash Surrender Value of Life Insurance	The Company has purchased bank-owned life insurance policies on certain bank officers. Bank-owned life insurance is recorded at its cash surrender value. Changes in the cash surrender values are included in noninterest income.
Federal Home Loan Bank Stock	The Bank, as a member of the Federal Home Loan Bank of Des Moines (“FHLB”), is required to maintain an investment in the capital stock of the FHLB. The stock is redeemable at par by the FHLB, and is, therefore, carried at cost and periodically evaluated for impairment. The Company records FHLB dividends in interest income.
Goodwill and Other Intangible Assets	The Company tests goodwill for impairment on an annual basis and whenever events or changes in circumstances indicate that the Company may not be able to recover the respective asset's carrying amount. The Company's annual test for impairment was performed in the fourth quarter of December 31, 2016 . Such tests involve the use of estimates and assumptions. Core deposit intangibles are amortized using an accelerated method over an estimated useful life of approximately 10 years. The Company identifies potential goodwill impairments by first performing a qualitative assessment and then by comparing the fair value of a reporting unit to its carrying amount, including goodwill. Goodwill impairment is not indicated as long as it is more likely than not that impairment has not occurred based on the qualitative assessment or based on the quantitative assessment the fair value of the reporting unit is greater than its carrying value. The second step of the impairment test is only required if a goodwill impairment is identified in step one. The second step of the test compares the implied fair value of goodwill to its carrying amount. If the carrying amount of goodwill exceeds its implied fair value, an impairment loss is recognized. That loss is equal to the carrying amount of goodwill that is in excess of its implied fair market value.
Impairment of Long-Lived Assets	Long-lived assets, such as fixed assets and purchased intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized in the amount by which the carrying amount of the asset exceeds the fair value of the asset. Assets to be disposed of are separately presented in the balance sheet and reported at the lower of the carrying amount or fair value less costs to sell, and are no longer depreciated. The assets and liabilities of a disposal group classified as held for sale are presented separately in the appropriate asset and liability sections of the balance sheet.
Derivative Financial Instruments and Hedging Activities	The Company uses derivative financial instruments to assist in the management of interest rate sensitivity and to modify the repricing, maturity and option characteristics of certain assets and liabilities. In addition, the Company also offers an interest rate hedge program that includes interest rate swaps to assist its customers in managing their interest rate risk profile. In order to eliminate the interest rate risk associated with offering these products, the Company enters into derivative contracts with third parties to offset the customer contracts. Derivative instruments are required to be measured at fair value and recognized as either assets or liabilities in the consolidated financial statements. Fair value represents the payment the Company would receive or pay if the item were sold or bought in a current transaction. The accounting for changes in fair value (gains or losses) of a hedged item is dependent on whether the related derivative is designated and qualifies for “hedge accounting.” The Company assigns derivatives to one of these categories at the purchase date: cash flow hedge, fair value hedge, or non-designated derivatives. An assessment of the expected and ongoing hedge effectiveness of any derivative designated a fair value hedge or cash flow hedge is performed as required by the accounting standards. Derivatives are included in other assets and other liabilities in the consolidated balance sheets. Generally, the only derivative instruments used by the Company have been interest rate swaps and interest rate caps. The Company does not currently have derivative instruments designated as fair value or cash flow hedges. Certain derivative financial instruments are not designated as cash flow or as fair value hedges for accounting purposes. These non-designated derivatives are intended to provide interest rate protection on net interest income or noninterest income but do not meet hedge accounting treatment. Customer accommodation interest rate swap contracts are not designated as hedging instruments. Changes in the fair value of these instruments are recorded in interest income or noninterest income in the consolidated statements of income depending on the underlying hedged item.
Income Taxes	The Company and its subsidiaries file a consolidated federal income tax return. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled. We evaluated the need for deferred tax asset valuation allowances based on a more-likely-than-not standard. The ability to realize deferred tax assets depends on the ability to generate sufficient positive taxable income within the carryback or carryforward periods provided for in the laws for each applicable taxing jurisdiction. We consider the following possible sources of taxable income: future reversal patterns of existing taxable temporary differences, future taxable income exclusive of reversing temporary differences, taxable income in prior carryback years and the availability of qualified tax planning strategies. The assessment regarding whether a valuation allowance is required or should be adjusted depends on all available positive and negative factors including, but not limited to, nature, frequency, and severity of recent losses, duration of available carryforward periods, experience with tax attributes expiring unused and near and medium term financial outlook. Because of the complexity of tax laws and regulations, interpretation can be difficult and subject to legal judgment given specific facts and circumstances. It is possible that others, given the same information, may at any point in time reach different reasonable conclusions regarding the estimated amounts of accrued taxes.
Stock-Based Compensation	tock-based compensation is recognized as an expense for stock options, restricted stock awards, and restricted stock units granted to employees in return for employee service. Equity classified awards are measured at the grant date fair value using either an observable market value or a valuation methodology, and recognized over the requisite service period on a straight-line basis, reduced for estimated forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. A description of the Company's stock-based employee compensation plan is described in Note 16 - Compensation Plans.
Acquisitions and Divestitures	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, including the amount assigned to identifiable intangible assets. The purchase price allocation process requires an estimation of the fair values of the assets acquired and the liabilities assumed. When a business combination agreement provides for an adjustment to the cost of the combination contingent on future events, the Company includes an estimate of the acquisition-date fair value as part of the cost of the combination. The results of operations of the acquired business are included in the Company's consolidated financial statements from the respective date of acquisition. As a general rule, goodwill established in connection with a stock purchase is non-deductible for tax purposes. For divestitures, the Company measures an asset (disposal group) classified as held for sale at the lower of its carrying value at the date the asset is initially classified as held for sale or its fair value less costs to sell. The Company reports the results of operations of an entity or group of components that either has been disposed of or held for sale as discontinued operations only if the disposal of that component represents a strategic shift that has or will have a major effect on an entity's operations and financial results. Any incremental direct costs incurred to transact the sale are allocated against the gain or loss on the sale. These costs would include items like legal fees, title transfer fees, broker fees, etc. Any goodwill and intangible assets associated with the portion of the reporting unit to be disposed of is included in the carrying amount of the business in determining the gain or loss on the sale. The Company has acquired a portfolio of PCI assets through FDIC assisted transactions. The PCI loans acquired were recorded at estimated fair value. As such, there was no allowance for credit losses established related to the acquired loans at the various acquisition dates and no carryover of the related allowance from the failed banks. The loans are accounted for in accordance with guidance for certain loans acquired in a transfer, when the loans have evidence of credit deterioration and it is probable at the date of acquisition that the acquirer will not collect all contractually required principal and interest payments. The difference between contractually required payments and the cash flows expected to be collected at acquisition is referred to as the non-accretable difference. Subsequent decreases to the expected cash flows will generally result in a provision for loan losses. Subsequent increases in cash flows result in a reversal of the provision for loan losses to the extent of prior charges and an adjustment in accretable yield, which will have a positive impact on interest income, prospectively.
Basic and Diluted Earnings Per Common Share	Basic earnings per common share data is calculated by dividing net income available to common shareholders 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 and the if-converted method for convertible securities related to the issuance of trust preferred securities.
Consolidated Statement of Comprehensive Income	The Consolidated Statement of Comprehensive Income includes the amount and the related tax impact that have been reclassified from accumulated other comprehensive income to net income. The classification adjustment for unrealized loss/gain on sale of securities included in net income has been recorded through the gain on sale of investment securities line item, within noninterest income, in the Company's Consolidated Statements of Operations.
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 that the Company would be required to sell the security before its anticipated recovery in market value. At December 31, 2016 and 2015 , management performed its quarterly analysis of all securities with an unrealized loss and concluded no individual securities were other-than-temporarily impaired.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
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. Years ended December 31, (in thousands, except share and per share data) 2016 2015 2014 Net income as reported $ 48,837 $ 38,450 $ 27,173 Impact of assumed conversions Interest on 9% convertible trust preferred securities, net of income tax — — 66 Net income available to common shareholders after assumed conversions $ 48,837 $ 38,450 $ 27,239 Weighted average common shares outstanding 20,003 19,984 19,761 Incremental shares from assumed conversions of convertible trust preferred securities — — 57 Additional dilutive common stock equivalents 287 333 292 Weighted average diluted common shares outstanding 20,290 20,317 20,110 Basic earnings per common share: $ 2.44 $ 1.92 $ 1.38 Diluted earnings per common share: $ 2.41 $ 1.89 $ 1.35

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2016
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: 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 December 31, 2015 (in thousands) Amortized Cost Gross Gross Fair Value Available for sale securities: Obligations of U.S. Government-sponsored enterprises $ 98,699 $ 309 $ — $ 99,008 Obligations of states and political subdivisions 40,700 1,343 (342 ) 41,701 Agency mortgage-backed securities 311,516 2,046 (2,501 ) 311,061 Total securities available for sale $ 450,915 $ 3,698 $ (2,843 ) $ 451,770 Held to maturity securities: Obligations of states and political subdivisions $ 14,831 $ 63 $ (50 ) $ 14,844 Agency mortgage-backed securities 28,883 — (286 ) 28,597 Total securities held to maturity $ 43,714 $ 63 $ (336 ) $ 43,441
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: 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 December 31, 2015 (in thousands) Amortized Cost Gross Gross Fair Value Available for sale securities: Obligations of U.S. Government-sponsored enterprises $ 98,699 $ 309 $ — $ 99,008 Obligations of states and political subdivisions 40,700 1,343 (342 ) 41,701 Agency mortgage-backed securities 311,516 2,046 (2,501 ) 311,061 Total securities available for sale $ 450,915 $ 3,698 $ (2,843 ) $ 451,770 Held to maturity securities: Obligations of states and political subdivisions $ 14,831 $ 63 $ (50 ) $ 14,844 Agency mortgage-backed securities 28,883 — (286 ) 28,597 Total securities held to maturity $ 43,714 $ 63 $ (336 ) $ 43,441
Investments Classified by Contractual Maturity Date	The amortized cost and estimated fair value of debt securities at December 31, 2016 , by contractual maturity, are shown below. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. The weighted average life of the mortgage-backed securities is approximately 4 years. Available for sale Held to maturity (in thousands) Amortized Cost Estimated Fair Value Amortized Cost Estimated Due in one year or less $ 52,457 $ 52,574 $ 658 $ 655 Due after one year through five years 76,529 77,254 5,609 5,559 Due after five years through ten years 11,912 11,842 7,380 7,241 Due after ten years 2,900 2,620 1,112 1,073 Mortgage-backed securities 319,345 316,507 65,704 65,111 $ 463,143 $ 460,797 $ 80,463 $ 79,639
Schedule of Unrealized Loss on Investments	The following table represents a summary of investment securities that had an unrealized loss: 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 December 31, 2015 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 2,199 12 9,395 380 11,594 392 Agency mortgage-backed securities 189,229 2,050 21,020 737 210,249 2,787 $ 191,428 $ 2,062 $ 30,415 $ 1,117 $ 221,843 $ 3,179
Schedule of Realized Gain (Loss)	The gross gains and losses realized from sales of available for sale investment securities were as follows: December 31, (in thousands) 2016 2015 2014 Gross gains realized $ 86 $ 63 $ — Gross losses realized — (40 ) — Proceeds from sales 2,493 41,069 —

Portfolio Loans (Tables)

Portfolio Loans (Tables)	12 Months Ended
	Dec. 31, 2016
Non-covered Loans [Line Items]
Summary of Loans to Executive Officers and Directors	Following is a summary of activity for the years ended December 31, 2016 , 2015 , and 2014 of loans to executive officers and directors, or to entities in which such individuals had beneficial interests as a shareholder, officer, or director. Such loans were made in the normal course of business on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with other customers and did not involve more than the normal risk of collectibility. (in thousands) December 31, 2016 December 31, 2015 December 31, 2014 Balance at beginning of year $ 4,394 $ 13,513 $ 11,752 New loans and advances 11,539 641 11,796 Payments and other reductions (527 ) (9,760 ) (10,035 ) Balance at end of year $ 15,406 $ 4,394 $ 13,513
Summary of Past Due and Impaired Loans	The following table presents details for past due and impaired loans: December 31, (in thousands) 2016 2015 2014 Total interest income that would have been recognized under original terms on impaired loans $ 1,079 $ 1,038 $ 1,013 Total cash received and recognized as interest income on impaired loans 251 226 118 Total interest income recognized on impaired loans still accruing 155 36 39
Non-Covered Loans
Non-covered Loans [Line Items]
Summary of Portfolio Loans by Category	Below is a summary of portfolio loans by category at December 31, 2016 and 2015 : (in thousands) December 31, 2016 December 31, 2015 Commercial and industrial $ 1,632,714 $ 1,484,327 Real estate loans: Commercial - investor owned 544,808 428,064 Commercial - owner occupied 350,148 342,959 Construction and land development 194,542 161,061 Residential 240,760 196,498 Total real estate loans 1,330,258 1,128,582 Consumer and other 156,182 137,537 Portfolio loans, before unearned loan (fees) costs 3,119,154 2,750,446 Unearned loan (fees) costs, net (762 ) 291 Portfolio loans $ 3,118,392 $ 2,750,737
Summary of Allowance for Loan Losses and the Recorded Investment in Portfolio Loans by Class and Category Based on Impairment Method	A summary of activity in the allowance for portfolio loan losses and the recorded investment in portfolio loans by class and category based on impairment method for the years ended indicated below 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 Balance at December 31, 2016 Allowance for loan losses: Balance, beginning of year $ 22,056 $ 3,484 $ 2,969 $ 1,704 $ 1,796 $ 1,432 $ 33,441 Provision (provision reversal) 6,569 (11 ) (1,202 ) (1,334 ) 129 1,400 5,551 Losses charged off (2,303 ) (95 ) — — (25 ) (1,912 ) (4,335 ) Recoveries 674 42 1,123 934 123 12 2,908 Balance, end of year $ 26,996 $ 3,420 $ 2,890 $ 1,304 $ 2,023 $ 932 $ 37,565 Balance at December 31, 2015 Allowance for loan losses: Balance, beginning of year $ 16,983 $ 4,382 $ 3,135 $ 1,715 $ 2,830 $ 1,140 $ 30,185 Provision (provision reversal) 6,976 (303 ) (1,626 ) (335 ) (58 ) 218 4,872 Losses charged off (3,699 ) (664 ) (38 ) (350 ) (1,313 ) (27 ) (6,091 ) Recoveries 1,796 69 1,498 674 337 101 4,475 Balance, end of year $ 22,056 $ 3,484 $ 2,969 $ 1,704 $ 1,796 $ 1,432 $ 33,441 Balance at December 31, 2014 Allowance for loan losses: Balance, beginning of year $ 12,246 $ 6,600 $ 4,096 $ 2,136 $ 2,019 $ 192 $ 27,289 Provision (provision reversal) 6,707 (2,063 ) (1,517 ) (322 ) 525 1,079 4,409 Losses charged off (3,738 ) (250 ) (450 ) (905 ) (48 ) (165 ) (5,556 ) Recoveries 1,768 95 1,006 806 334 34 4,043 Balance, end of year $ 16,983 $ 4,382 $ 3,135 $ 1,715 $ 2,830 $ 1,140 $ 30,185 (in thousands) Commercial and industrial CRE - investor owned CRE - owner occupied Construction and land development Residential real estate Consumer and other Total 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 Balance December 31, 2015 Allowance for loan losses - Ending balance: Individually evaluated for impairment $ 1,953 $ — $ 6 $ 369 $ 7 $ — $ 2,335 Collectively evaluated for impairment 20,103 3,484 2,963 1,335 1,789 1,432 31,106 Total $ 22,056 $ 3,484 $ 2,969 $ 1,704 $ 1,796 $ 1,432 $ 33,441 Loans - Ending balance: Individually evaluated for impairment $ 4,514 $ 921 $ 1,962 $ 2,800 $ 681 $ — $ 10,878 Collectively evaluated for impairment 1,479,813 427,143 340,997 158,261 195,817 137,828 2,739,859 Total $ 1,484,327 $ 428,064 $ 342,959 $ 161,061 $ 196,498 $ 137,828 $ 2,750,737
Summary of Portfolio Loans Individually Evaluated for Impairment and Recorded Investment in Impaired Non-Covered Loans by Category	A summary of portfolio loans individually evaluated for impairment by category at December 31, 2016 and 2015 , is as follows: 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 December 31, 2015 (in thousands) Unpaid Recorded Recorded Allowance Total Related Allowance Average Commercial and industrial $ 5,554 $ 509 $ 4,204 $ 4,713 $ 1,953 $ 6,970 Real estate: Commercial - investor owned 927 927 — 927 — 970 Commercial - owner occupied 329 85 113 198 6 301 Construction and land development 4,349 2,914 530 3,444 369 3,001 Residential 705 637 68 705 7 682 Consumer and other — — — — — — Total $ 11,864 $ 5,072 $ 4,915 $ 9,987 $ 2,335 $ 11,924
Schedule of Recorded Investment in Impaired Portfolio Loans by Category	The recorded investment in impaired portfolio loans by category at December 31, 2016 and 2015 , is as follows: December 31, 2016 (in thousands) Non-accrual Restructured 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 December 31, 2015 (in thousands) Non-accrual Restructured Total Commercial and industrial $ 4,406 $ 307 $ 4,713 Real estate: Commercial - investor owned 927 — 927 Commercial - owner occupied 198 — 198 Construction and land development 3,444 — 3,444 Residential 705 — 705 Consumer and other — — — Total $ 9,680 $ 307 $ 9,987
Summary of Recorded Investment by for Portfolio Loans Restructured	The recorded investment by category for the portfolio loans that have been restructured during the years ended December 31, 2016 and 2015 , is as follows: Year ended December 31, 2016 Year ended December 31, 2015 (in thousands, except for number of loans) Number of Loans Pre-Modification Outstanding Recorded Balance Post-Modification Outstanding Recorded Balance Number of Loans Pre-Modification Outstanding Recorded Balance Post-Modification Outstanding Recorded Balance Commercial and industrial 4 $ 12,114 $ 12,114 1 $ 303 $ 303 Real estate: Commercial - investor owned 1 248 248 — — — Commercial - owner occupied 1 13 13 — — — Construction and land development 1 20 20 — — — Residential — — — — — — Consumer and other — — — — — — Total 7 $ 12,395 $ 12,395 1 $ 303 $ 303
Summary of Recorded Investment by Category for Portfolio Loans Restructured and Subsequently Defaulted	uring the years ended December 31, 2016 and 2015
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 portfolio loans by portfolio class and category at December 31, 2016 and 2015 is shown below: 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 December 31, 2015 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ 505 $ 888 $ 1,393 $ 1,482,934 $ 1,484,327 Real estate: Commercial - investor owned 464 — 464 427,600 428,064 Commercial - owner occupied 94 184 278 342,681 342,959 Construction and land development 384 2,273 2,657 158,404 161,061 Residential 70 681 751 195,747 196,498 Consumer and other 20 — 20 137,808 137,828 Total $ 1,537 $ 4,026 $ 5,563 $ 2,745,174 $ 2,750,737
Summary of Recorded Investment by Risk Category of Portfolio Loans by Portfolio Class and Category	The recorded investment by risk category of the portfolio loans by portfolio class and category at December 31, 2016 and December 31, 2015 is as follows: December 31, 2016 (in thousands) Pass (1-6) Watch (7) Substandard (8) 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 December 31, 2015 (in thousands) Pass (1-6) Watch (7) Substandard (8) Total Commercial and industrial $ 1,356,864 $ 90,370 $ 37,093 $ 1,484,327 Real estate: Commercial - investor owned 403,820 18,868 5,376 428,064 Commercial - owner occupied 314,791 24,727 3,441 342,959 Construction and land development 146,601 10,114 4,346 161,061 Residential 188,269 5,138 3,091 196,498 Consumer and other 131,060 721 6,047 137,828 Total $ 2,541,405 $ 149,938 $ 59,394 $ 2,750,737

Purchased Credit Impaired ("P37

Purchased Credit Impaired ("PCI") Loans (Tables)	12 Months Ended
	Dec. 31, 2016
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 years ended December 31, 2016 and 2015 . (in thousands) Contractual Cashflows Non-accretable Difference Accretable Yield Carrying Amount Balance January 1, 2016 $ 116,689 $ 26,765 $ 25,341 $ 64,583 Principal reductions and interest payments (25,669 ) — — (25,669 ) Accretion of loan discount — — (6,155 ) 6,155 Changes in contractual and expected cash flows due to remeasurement 11,718 766 (1,500 ) 12,452 Reductions due to disposals (36,735 ) (8,629 ) (4,510 ) (23,596 ) Balance December 31, 2016 $ 66,003 $ 18,902 $ 13,176 $ 33,925 Balance January 1, 2015 $ 178,145 $ 65,719 $ 28,733 $ 83,693 Principal reductions and interest payments (24,441 ) — — (24,441 ) Accretion of loan discount — — (10,775 ) 10,775 Changes in contractual and expected cash flows due to remeasurement (3,574 ) (30,413 ) 12,132 14,707 Reductions due to disposals (33,441 ) (8,541 ) (4,749 ) (20,151 ) Balance December 31, 2015 $ 116,689 $ 26,765 $ 25,341 $ 64,583
Covered Loans
Covered Loans [Line Items]
Summary of PCI Loans by Category	Below is a summary of PCI loans by category at December 31, 2016 and 2015 : December 31, 2016 December 31, 2015 ($ in thousands) Weighted- Average Risk Rating 1 Recorded Investment PCI Loans Weighted- Average Risk Rating 1 Recorded Investment PCI Loans Commercial and industrial 5.87 $ 3,523 6.70 $ 3,863 Real estate loans: Commercial - investor owned 6.95 8,162 6.98 25,272 Commercial - owner occupied 6.39 11,863 6.30 19,414 Construction and land development 5.80 4,365 6.28 6,838 Residential 5.64 11,792 5.44 19,287 Total real estate loans 36,182 70,811 Consumer and other 1.64 64 1.89 84 Purchased credit impaired loans $ 39,769 $ 74,758 (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 December 31, 2016 and 2015 is shown below: 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 December 31, 2015 (in thousands) 30-89 Days Past Due 90 or More Past Due Total Past Due Current Total Commercial and industrial $ — $ — $ — $ 3,863 $ 3,863 Real estate: Commercial - investor owned 2,342 3,661 6,003 19,269 25,272 Commercial - owner occupied 731 — 731 18,683 19,414 Construction and land development — — — 6,838 6,838 Residential 1,594 130 1,724 17,563 19,287 Consumer and other 4 — 4 80 84 Total $ 4,671 $ 3,791 $ 8,462 $ 66,296 $ 74,758
Summary of FDIC Loss Share Receivable	A summary of activity in the FDIC loss share receivable for the year ended December 31, 2015 is as follows: (in thousands) December 31, 2015 Balance at beginning of period $ 15,866 Adjustments not reflected in income: Cash received from the FDIC for covered assets (3,528 ) FDIC reimbursable recoveries (1,386 ) Reductions for loss share termination (5,922 ) Adjustments reflected in income: Amortization, net (2,293 ) Loan impairment reversal (1,113 ) Reductions for payments on covered assets in excess of expected cash flows (1,624 ) Balance at end of period $ —

Derivative Financial Instrume38

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2016
Risk Management
Derivative [Line Items]
Schedule of Notional Amounts and Fair Values of Derivative Instruments and Client-Related Derivative Instruments	The notional amount of the derivative instruments used to manage risk was $3.5 million at December 31, 2016 and 2015 .
Client-Related
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) December 31, December 31, December 31, December 31, December 31, December 31, Non-designated hedging instruments Interest rate swap contracts $ 124,322 $ 153,630 $ 982 $ 1,155 $ 982 $ 1,155 Foreign exchange forward contracts 3,034 — 3,034 — 3,034 —
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	Changes in the fair value of client-related derivative instruments are recognized currently in operations. For the years ended December 31, 2016 and 2015 , the gains and losses offset each other due to the Company's hedging of the client swaps with other bank counterparties.

Fixed Assets (Tables)

Fixed Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Summary of Fixed Assets	A summary of fixed assets at December 31, 2016 and 2015 , is as follows: December 31, (in thousands) 2016 2015 Land $ 3,103 $ 3,103 Buildings and leasehold improvements 18,054 17,837 Furniture, fixtures and equipment 6,136 4,892 Capitalized software 1,305 1,030 28,598 26,862 Less accumulated depreciation and amortization 13,688 12,020 Total fixed assets $ 14,910 $ 14,842
Future Aggregate Minimum Rental Commitments	The future aggregate minimum rental commitments (in thousands) required under the leases are shown below: Year Amount 2017 $ 2,797 2018 2,684 2019 2,676 2020 2,637 2021 2,642 Thereafter 6,667 Total $ 20,103

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets	The table below presents a summary of intangible assets: (in thousands) Years ended December 31, 2016 2015 Gross core deposit intangible balance, beginning of year $ 9,060 $ 9,060 Accumulated amortization (6,909 ) (5,985 ) Core deposit intangible, net, end of year $ 2,151 $ 3,075
Expected Amortization Schedule for the Core Deposit Intangible	The following table reflects the expected amortization schedule for the core deposit intangible (in thousands) at December 31, 2016 . Year Core Deposit Intangible 2017 $ 760 2018 595 2019 430 2020 265 After 2020 101 $ 2,151

Maturity of Certificates of D41

Maturity of Certificates of Deposit (Tables)	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Summary of Certificates of Deposit Maturities	Following is a summary of certificates of deposit maturities at December 31, 2016 : (in thousands) Brokered Other Total Less than 1 year $ 117,145 $ 197,262 $ 314,407 Greater than 1 year and less than 2 years — 67,909 67,909 Greater than 2 years and less than 3 years — 28,806 28,806 Greater than 3 years and less than 4 years — 45,341 45,341 Greater than 4 years and less than 5 years — 16,696 16,696 $ 117,145 $ 356,014 $ 473,159

Subordinated Debentures (Tables

Subordinated Debentures (Tables)	12 Months Ended
	Dec. 31, 2016
Brokers and Dealers [Abstract]
Schedule of Subordinated Debentures	The amounts and terms of each issuance of the Company's subordinated debentures at December 31, 2016 and 2015 were as follows: Amount Maturity Date Call Date Interest Rate (in thousands) 2016 2015 EFSC Clayco Statutory Trust I $ 3,196 $ 3,196 December 17, 2033 December 17, 2008 Floats 3MO LIBOR + 2.85% EFSC Capital Trust II 5,155 5,155 June 17, 2034 June 17, 2009 Floats 3MO LIBOR + 2.65% EFSC Statutory Trust III 11,341 11,341 December 15, 2034 December 15, 2009 Floats 3MO LIBOR + 1.97% EFSC Clayco Statutory Trust II 4,124 4,124 September 15, 2035 September 15, 2010 Floats 3MO LIBOR + 1.83% EFSC Statutory Trust IV 10,310 10,310 December 15, 2035 December 15, 2010 Floats 3MO LIBOR + 1.44% EFSC Statutory Trust V 4,124 4,124 September 15, 2036 September 15, 2011 Floats 3MO LIBOR + 1.60% EFSC Capital Trust VI 14,433 14,433 March 30, 2037 March 30, 2012 Floats 3MO LIBOR + 1.60% EFSC Capital Trust VII 4,124 4,124 December 15, 2037 December 15, 2012 Floats 3MO LIBOR + 2.25% Total trust preferred securities 56,807 56,807 Fixed-to-floating rate subordinated notes 50,000 — November 1, 2026 November 1, 2021 Fixed 4.75% until Less: Debt issuance costs (1,267 ) — Total fixed-to-floating rate subordinated notes 48,733 — Total subordinated debentures and notes $ 105,540 $ 56,807

Federal Home Loan Bank Advanc43

Federal Home Loan Bank Advances (Tables)	12 Months Ended
	Dec. 31, 2016
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank, Advances [Table Text Block]	2016 2015 ($ in thousands) Term Outstanding Balance Weighted Rate Outstanding Balance Weighted Rate Non-amortizing fixed advance Less than 1 year $ — — % $ 110,000 0.45 % Non-amortizing fixed advance Greater than 1 year — — % — — % Total Federal Home Loan Bank Advances $ — — % $ 110,000 0.45 %

Other Borrowings and Notes Pa44

Other Borrowings and Notes Payable (Tables)	12 Months Ended
	Dec. 31, 2016
Other Borrowings
Debt Instrument [Line Items]
Summary of Other Borrowings	A summary of other borrowings is as follows: December 31, ($ in thousands) 2016 2015 Securities sold under repurchase agreements $ 276,980 $ 270,326 Average balance during the year $ 206,643 $ 195,328 Maximum balance outstanding at any month-end 276,980 270,326 Average interest rate during the year 0.19 % 0.22 % Average interest rate at December 31 0.18 % 0.16 %
Unsecured Term Loan
Debt Instrument [Line Items]
Summary of Other Borrowings	A summary of the Term Loan is as follows: ($ in thousands) December 31, 2015 Term Loan $ — Average balance during the year $ 4,509 Maximum balance outstanding at any month-end 5,700 Weighted average interest rate during the year 3.01 % Average interest rate at December 31 — %

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2016
Regulated Operations [Abstract]
Schedule of Actual Capital Amounts and Ratios	The actual capital amounts and ratios are presented in the table below: Actual For Capital Adequacy Purposes To Be Well Capitalized Under Applicable Action Provisions ($ in thousands) Amount Ratio Amount Ratio Amount Ratio As of December 31, 2016: Total Capital (to Risk Weighted Assets) Enterprise Financial Services Corp $ 506,349 13.48 % $ 300,573 8.00 % $ — — % Enterprise Bank & Trust 430,981 11.53 298,982 8.00 373,728 10.00 Tier 1 Capital (to Risk Weighted Assets) Enterprise Financial Services Corp 412,865 10.99 225,430 6.00 — — Enterprise Bank & Trust 387,497 10.37 224,237 6.00 298,982 8.00 Common Equity Tier 1 Capital (to Risk Weighted Assets) 1 Enterprise Financial Services Corp 357,729 9.52 169,072 4.50 — — Enterprise Bank & Trust 387,461 10.37 168,178 4.50 242,923 6.50 Leverage Ratio (Tier 1 Capital to Average Assets) Enterprise Financial Services Corp 412,865 10.42 158,480 4.00 — — Enterprise Bank & Trust 387,497 9.81 157,933 4.00 197,417 5.00 As of December 31, 2015: Total Capital (to Risk Weighted Assets) Enterprise Financial Services Corp $ 418,367 11.85 % $ 282,442 8.00 % $ — — % Enterprise Bank & Trust 386,531 10.98 281,632 8.00 352,040 10.00 Tier 1 Capital (to Risk Weighted Assets) Enterprise Financial Services Corp 374,676 10.61 211,831 6.00 — — Enterprise Bank & Trust 342,840 9.74 211,224 6.00 281,632 8.00 Common Equity Tier 1 Capital (to Risk Weighted Assets) 1 Enterprise Financial Services Corp 319,553 9.05 158,873 4.50 — — Enterprise Bank & Trust 342,816 9.74 158,418 4.50 228,826 6.50 Leverage Ratio (Tier 1 Capital to Average Assets) Enterprise Financial Services Corp 374,676 10.71 139,893 4.00 — — Enterprise Bank & Trust 342,840 9.84 139,311 4.00 174,138 5.00 1 Not an applicable regulatory ratio until implementation of Basel III in 2015

Compensation Plans (Tables)

Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding Long Term Incentive Awards [Table Text Block]	(in thousands, except share and per share data) 2015 - 2017 Cycle 2016 - 2018 Cycle Shares issuable at target 113,903 95,694 Maximum shares issuable 142,292 117,681 Unrecognized compensation cost $ 1,140 $ 1,929 Weighted average grant date fair value 19.21 25.26
Summary of Employee Stock Option and SSARs Activity	Following is a summary of the employee stock option and SSAR activity for 2016 . (in thousands, except share and per share data) Shares Weighted Weighted Aggregate Outstanding at December 31, 2015 388,103 $ 19.15 Granted — — Exercised (117,857 ) 19.85 Forfeited — — Outstanding at December 31, 2016 270,246 $ 18.85 1.9 years $ 6,527 Exercisable at December 31, 2016 270,246 $ 18.85 1.9 years $ 6,527
Summary of Restricted Stock Units Activity	A summary of the status of the Company's RSU awards as of December 31, 2016 and changes during the year then ended is presented below. Shares Weighted Average Grant Date Fair Value Outstanding at December 31, 2015 86,354 $ 14.31 Granted 32,913 29.71 Vested (56,089 ) 14.25 Forfeited (4,480 ) 13.51 Outstanding at December 31, 2016 58,698 $ 23.06
Stock Options and SSARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Various Information	Various information related to the stock options and SSARs is shown below. (in thousands) 2016 2015 2014 Compensation expense $ — $ 50 $ 103 Intrinsic value of option exercises on date of exercise 1,156 74 226 Cash received from the exercise of stock options 87 126 149
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Various Information	Various information related to the RSUs is shown below. ($ in thousands) 2016 2015 2014 Compensation expense $ 850 $ 725 $ 945 Total fair value at vesting date 2,275 809 913 Total unrecognized compensation cost for nonvested stock units 1,084 942 1,462 Expected years to recognize unearned compensation 1.6 years 1.7 years 2.7 years
Stock Plan for Non-Management Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Various Information	Various information related to the Director Plan is shown below. (in thousands, except share and per share data) 2016 2015 2014 Shares issued 12,528 16,283 23,135 Weighted average fair value $ 31.25 $ 24.43 $ 19.20 Compensation expense 407 373 329

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The components of income tax expense for the years ended December 31 are as follows: Years ended December 31, (in thousands) 2016 2015 2014 Current: Federal $ 17,005 $ 22,916 $ 9,399 State and local 1,734 2,798 195 Total current 18,739 25,714 9,594 Deferred: Federal 5,959 (5,266 ) 3,908 State and local 1,304 (497 ) 369 Total deferred 7,263 (5,763 ) 4,277 Total income tax expense $ 26,002 $ 19,951 $ 13,871
Schedule of Income Tax Rate Reconciliation	A reconciliation of expected income tax expense, computed by applying the statutory federal income tax rate of 35% in 2016 , 2015 , and 2014 to income before income taxes and the amounts reflected in the consolidated statements of operations is as follows: Years ended December 31, (in thousands) 2016 2015 2014 Income tax expense at statutory rate $ 26,194 $ 20,440 $ 14,365 Increase (reduction) in income tax resulting from: Tax-exempt income, net (945 ) (931 ) (857 ) State and local income taxes, net 1,673 1,414 741 Bank-owned life insurance, net (544 ) (462 ) (535 ) Non-deductible expenses 263 259 290 Change in estimated rate for deferred taxes 302 — — Tax benefits of LIHTC investments, net (181 ) (179 ) (158 ) Other, net (760 ) (590 ) 25 Total income tax expense $ 26,002 $ 19,951 $ 13,871
Schedule of Deferred Tax Assets and Deferred Tax Liabilities	The tax effect of temporary differences that gave rise to significant portions of the deferred tax assets and deferred tax liabilities is as follows: Years ended December 31, (in thousands) 2016 2015 Deferred tax assets: Allowance for loan losses $ 16,496 $ 16,705 Basis difference on PCI assets, net 5,551 8,806 Basis difference on Other real estate 317 328 Deferred compensation 4,217 4,509 Goodwill and other intangible assets 5,520 6,973 Accrued compensation 899 2,222 Unrealized losses on securities available for sale 1,019 — Other, net 925 907 Total deferred tax assets 34,944 40,450 Deferred tax liabilities: Unrealized gains on securities available for sale — 183 State tax credits held for sale, net of economic hedge 376 594 Core deposit intangibles 817 1,178 Total deferred tax liabilities 1,193 1,955 Net deferred tax asset $ 33,751 $ 38,495
Schedule of Unrecognized Tax Benefits	The activity in the gross liability for unrecognized tax benefits was as follows: (in thousands) 2016 2015 2014 Balance at beginning of year $ 1,359 $ 1,884 $ 1,257 Additions based on tax positions related to the current year 239 230 401 Additions for tax positions of prior years 39 46 523 Reductions for tax positions of prior years — (437 ) — Settlements or lapse of statute of limitations (457 ) (364 ) (297 ) Balance at end of year $ 1,180 $ 1,359 $ 1,884

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Schedule of Commitments	The contractual amounts of off-balance-sheet financial instruments as of December 31, 2016 , and December 31, 2015 , are as follows: (in thousands) December 31, 2016 December 31, 2015 Commitments to extend credit $ 1,075,170 $ 1,140,028 Letters of credit 78,954 54,648

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
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 December 31, 2016 and 2015 , segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value. 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 December 31, 2015 (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 $ — $ 99,008 $ — $ 99,008 Obligations of states and political subdivisions — 38,624 3,077 41,701 Residential mortgage-backed securities — 311,061 — 311,061 Total securities available for sale — 448,693 3,077 451,770 State tax credits held for sale — — 5,941 5,941 Derivative financial instruments — 1,155 — 1,155 Total assets $ — $ 449,848 $ 9,018 $ 458,866 Liabilities Derivative financial instruments $ — $ 1,155 $ — $ 1,155 Total liabilities $ — $ 1,155 $ — $ 1,155
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 December 31, 2016 and 2015 . • Purchases, sales, issuances and settlements . There were no Level 3 purchases during the year ended December 31, 2016 . • Transfers in and/or out of Level 3 . There were no transfers in and/or out of Level 3 for the years ending December 31, 2016 and 2015 . Securities available for sale, at fair value Years ended December 31, (in thousands) 2016 2015 Beginning balance $ 3,077 $ 3,059 Total gains: Included in other comprehensive income 12 18 Purchases, sales, issuances and settlements — — Ending balance $ 3,089 $ 3,077 Change in unrealized gains relating to assets still held at the reporting date $ 12 $ 18 State tax credits held for sale, at fair value Years ended December 31, (in thousands) 2016 2015 Beginning balance $ 5,941 $ 11,689 Total gains: Included in earnings 177 406 Purchases, sales, issuances and settlements: Sales (2,533 ) (6,154 ) Ending balance $ 3,585 $ 5,941 Change in unrealized losses relating to assets still held at the reporting date $ (575 ) $ (1,212 )
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 December 31, 2016 and 2015 . December 31, 2016 (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 year ended Impaired loans $ 175 $ — $ — $ 175 $ 4,335 Other real estate — — — — 1 Total $ 175 $ — $ — $ 175 $ 4,336 December 31, 2015 (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 year ended Impaired loans $ 2,561 $ — $ — $ 2,561 $ 6,091 Other real estate 753 — — 753 83 Total $ 3,314 $ — $ — $ 3,314 $ 6,174 (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 December 31, 2016 and 2015 . December 31, 2016 December 31, 2015 (in thousands) Carrying Amount Estimated fair value Carrying Amount Estimated fair value Balance sheet assets Cash and due from banks $ 54,288 $ 54,288 $ 47,935 $ 47,935 Federal funds sold 446 446 91 91 Interest-bearing deposits 145,048 145,048 47,131 47,131 Securities available for sale 460,797 460,797 451,770 451,770 Securities held to maturity 80,463 79,639 43,714 43,441 Other investments, at cost 14,840 14,840 17,455 17,455 Loans held for sale 9,562 9,562 6,598 6,598 Derivative financial instruments 4,016 4,016 1,155 1,155 Portfolio loans, net 3,114,752 3,125,701 2,781,879 2,782,704 State tax credits, held for sale 38,071 41,264 45,850 49,588 Accrued interest receivable 11,117 11,117 8,399 8,399 Balance sheet liabilities Deposits 3,233,361 3,232,414 2,784,591 2,784,654 Subordinated debentures and notes 105,540 86,052 56,807 35,432 Federal Home Loan Bank advances — — 110,000 109,994 Other borrowings 276,980 276,905 270,326 270,286 Derivative financial instruments 4,016 4,016 1,155 1,155 Accrued interest payable 1,105 1,105 629 629
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 on the consolidated balance sheets at fair value at December 31, 2016 , and December 31, 2015 . Estimated Fair Value Measurement at Reporting Date Using Balance at (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 Estimated Fair Value Measurement at Reporting Date Using Balance at (in thousands) Level 1 Level 2 Level 3 Financial Assets: Securities held to maturity $ — $ 43,441 $ — $ 43,441 Portfolio loans, net — — 2,782,704 2,782,704 State tax credits, held for sale — — 43,647 43,647 Financial Liabilities: Deposits 2,428,403 — 356,251 2,784,654 Subordinated debentures and notes — 35,432 — 35,432 Federal Home Loan Bank advances — 109,994 — 109,994 Other borrowings — 270,286 — 270,286

Parent Company Only Condensed50

Parent Company Only Condensed Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2016
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Balance Sheets	Condensed Balance Sheets December 31, (in thousands) 2016 2015 Assets Cash $ 52,245 $ 12,032 Investment in Enterprise Bank & Trust 416,831 374,092 Investment in nonbank subsidiaries 2,798 1,510 Other assets 22,111 20,357 Total assets $ 493,985 $ 407,991 Liabilities and Shareholders' Equity Subordinated debentures and notes $ 105,540 $ 56,807 Accounts payable and other liabilities 1,347 355 Shareholders' equity 387,098 350,829 Total liabilities and shareholders' equity $ 493,985 $ 407,991
Condensed Statements of Operations	Condensed Statements of Operations Years ended December 31, (in thousands) 2016 2015 2014 Income: Dividends from subsidiaries $ 7,500 $ 10,000 $ 10,000 Other 491 249 225 Total income 7,991 10,249 10,225 Expenses: Interest expense-subordinated debentures and notes 1,893 1,248 1,322 Interest expense-notes payable 53 144 193 Other expenses 5,526 3,823 4,402 Total expenses 7,472 5,215 5,917 Income before taxes and equity in undistributed earnings of subsidiaries 519 5,034 4,308 Income tax benefit 2,583 2,118 2,305 Net income before equity in undistributed earnings of subsidiaries 3,102 7,152 6,613 Equity in undistributed earnings of subsidiaries 45,735 31,298 20,560 Net income and comprehensive income $ 48,837 $ 38,450 $ 27,173
Condensed Statements of Cash Flow	Condensed Statements of Cash Flows Years Ended December 31, (in thousands) 2016 2015 2014 Cash flows from operating activities: Net income $ 48,837 $ 38,450 $ 27,173 Adjustments to reconcile net income to net cash provided by (used in) operating activities: Share-based compensation 3,367 3,601 2,950 Net income of subsidiaries (53,235 ) (41,298 ) (30,560 ) Dividends from subsidiaries 7,500 10,000 10,000 Excess tax expense of share-based compensation (1,327 ) (449 ) (205 ) Other, net 1,848 848 704 Net cash provided by operating activities 6,990 11,152 10,062 Cash flows from investing activities: Cash contributions to subsidiaries (250 ) — — Purchases of other investments (2,435 ) (2,832 ) (2,224 ) Proceeds from distributions on other investments 1,151 880 176 Net cash used by investing activities (1,534 ) (1,952 ) (2,048 ) Cash flows from financing activities: Proceeds from issuance of subordinated notes 48,733 — — Repayments of notes payable — (5,700 ) (4,800 ) Cash dividends paid (8,211 ) (5,259 ) (4,177 ) Excess tax benefit of share-based compensation 1,327 449 205 Payments for the repurchase of common stock (4,889 ) — — Issuance of common stock 2 2 2 Proceeds from the issuance of equity instruments, net (2,205 ) (1,192 ) (681 ) Net cash provided (used) by financing activities 34,757 (11,700 ) (9,451 ) Net increase (decrease) in cash and cash equivalents 40,213 (2,500 ) (1,437 ) Cash and cash equivalents, beginning of year 12,032 14,532 15,969 Cash and cash equivalents, end of year $ 52,245 $ 12,032 $ 14,532

Quarterly Condensed Financial51

Quarterly Condensed Financial Information (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following table presents unaudited quarterly financial information for the periods indicated: 2016 (in thousands, except per share data) 4th Quarter 3rd Quarter 2nd Quarter 1st Quarter Interest income $ 39,438 $ 37,293 $ 37,033 $ 35,460 Interest expense 3,984 3,463 3,250 3,032 Net interest income 35,454 33,830 33,783 32,428 Provision for portfolio loan losses 964 3,038 716 833 Provision reversal for PCI loan losses (343 ) (1,194 ) (336 ) (73 ) Net interest income after provision for loan losses 34,833 31,986 33,403 31,668 Noninterest income 9,029 6,976 7,049 6,005 Noninterest expense 23,181 20,814 21,353 20,762 Income before income tax expense 20,681 18,148 19,099 16,911 Income tax expense 7,053 6,316 6,747 5,886 Net income $ 13,628 $ 11,832 $ 12,352 $ 11,025 Earnings per common share: Basic $ 0.68 $ 0.59 $ 0.62 $ 0.55 Diluted 0.67 0.59 0.61 0.54 2015 (in thousands, except per share data) 4th Quarter 3rd Quarter 2nd Quarter 1st Quarter Interest income $ 35,096 $ 33,180 $ 32,352 $ 32,151 Interest expense 3,017 3,174 3,072 3,106 Net interest income 32,079 30,006 29,280 29,045 Provision for portfolio loan losses 543 599 2,150 1,580 Provision reversal for PCI loan losses (917 ) (227 ) — (3,270 ) Net interest income after provision for loan losses 32,453 29,634 27,130 30,735 Noninterest income 6,557 4,729 5,806 3,583 Noninterest expense 22,886 19,932 19,458 19,950 Income before income tax expense 16,124 14,431 13,478 14,368 Income tax expense 5,445 4,722 4,762 5,022 Net income $ 10,679 $ 9,709 $ 8,716 $ 9,346 Earnings per common share: Basic $ 0.53 $ 0.49 $ 0.44 $ 0.47 Diluted 0.52 0.48 0.43 0.46

Summary of Significant Accoun52

Summary of Significant Accounting Policies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)segment	Dec. 31, 2015USD ($)
Property, Plant and Equipment [Line Items]
Number of reportable segments | segment	1
Required reserves on deposits maintained	$ 18.2	$ 13.8
Minimum period of consecutive contractual payments to no longer be considered in nonaccrual status	6 years
Removal of remaining clawback liability, FDIC loss share termination		3.5
Removal of remaining FDIC receivable, FDIC loss share termination		$ 7.2
Percentage of losses from loss share agreements in noninterest income		80.00%
Finite-lived intangible assets useful life	10 years	10 years
Furniture, Fixtures and Equipment [Member] | Minimum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	3 years
Furniture, Fixtures and Equipment [Member] | Maximum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	10 years
Building and Leasehold Improvements [Member] | Minimum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	10 years
Building and Leasehold Improvements [Member] | Maximum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	40 years
Software [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	3 years
Core Deposits [Member]
Property, Plant and Equipment [Line Items]
Finite-lived intangible assets useful life	10 years
State and Local Jurisdiction [Member]
Property, Plant and Equipment [Line Items]
Right to receive state tax credit at agreed upon rates	10 years

Acquisitions & Divestitures - N

Acquisitions & Divestitures - Narrative (Details)	12 Months Ended
	Dec. 31, 2016USD ($)	Feb. 10, 2017USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets - JCB	$ 937,000,000
Loans - JCB	699,000,000
Deposits - JCB	$ 767,000,000
Number of operating JCB branches	13
Sale of Stock, Consideration Received Per Transaction		$ 85.39
EFSC common stock offered per share of JCB common stock		2.75
Total shares awarded to JCB shareholders		3,300,000
Total cash paid to JCB shareholders and holders of JCB stock options		$ 29,300,000
EFSC Closing Stock Price		42.95
Transaction value including JCB's common stock and stock options		$ 171,000,000
Business Combination, Acquisition Related Costs	$ 1,400,000

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share
Net income as reported	$ 13,628	$ 11,832	$ 12,352	$ 11,025	$ 10,679	$ 9,709	$ 8,716	$ 9,346	$ 48,837	$ 38,450	$ 27,173
Impact of assumed conversions
Interest on 9% convertible trust preferred securities, net of income tax									0	0	66
Net income available to common shareholders after assumed conversions									$ 48,837	$ 38,450	$ 27,239
Weighted average common shares outstanding (in shares)									20,003,000	19,984,000	19,761,000
Incremental shares from assumed conversions of convertible trust preferred securities (in shares)									0	0	57,000
Additional dilutive common stock equivalents (in shares)									287,000	333,000	292,000
Weighted average diluted common shares outstanding (in shares)									20,290,000	20,317,000	20,110,000
Basic earnings per common share (in dollars per share)	$ 0.68	$ 0.59	$ 0.62	$ 0.55	$ 0.53	$ 0.49	$ 0.44	$ 0.47	$ 2.44	$ 1.92	$ 1.38
Diluted earnings per common share (in dollars per share)	$ 0.67	$ 0.59	$ 0.61	$ 0.54	$ 0.52	$ 0.48	$ 0.43	$ 0.46	$ 2.41	$ 1.89	$ 1.35
Common stock equivalents excluded from earnings per share calculations due to anti-dilutive effect (in shares)									0	79,670	287,546
Convertible Debt Securities
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Convertible trust preferred securities, interest rate, stated percentage	9.00%				9.00%				9.00%	9.00%	9.00%

Investments - Schedule of Avail

Investments - Schedule of Available-for-sale and Held-to-Maturity Securities Reconciliation (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 80,463	$ 43,714
Gross Unrealized Gains	56	63
Gross Unrealized Losses	(880)	(336)
Fair Value	79,639	43,441
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	463,143	450,915
Gross Unrealized Gains	2,079	3,698
Gross Unrealized Losses	(4,425)	(2,843)
Fair Value	460,797	451,770
Obligations of U.S. Government-sponsored enterprises
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	107,312	98,699
Gross Unrealized Gains	348	309
Gross Unrealized Losses	0	0
Fair Value	107,660	99,008
Obligations of states and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	36,486	40,700
Gross Unrealized Gains	630	1,343
Gross Unrealized Losses	(485)	(342)
Fair Value	36,631	41,701
Residential mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	319,345	311,516
Gross Unrealized Gains	1,101	2,046
Gross Unrealized Losses	(3,940)	(2,501)
Fair Value	316,506	311,061
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	14,759	14,831
Gross Unrealized Gains	11	63
Gross Unrealized Losses	(242)	(50)
Fair Value	14,528	14,844
Residential mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	65,704	28,883
Gross Unrealized Gains	45	0
Gross Unrealized Losses	(638)	(286)
Fair Value	$ 65,111	$ 28,597

Investments - Investments Class

Investments - Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Available for sale, Amortized Cost
Due in one year or less	$ 52,457
Due after one year through five years	76,529
Due after five years through ten years	11,912
Due after ten years	2,900
Mortgage-backed securities	319,345
Amortized Cost	463,143	$ 450,915
Available for sale, Estimated Fair Value
Due in one year or less	52,574
Due after one year through five years	77,254
Due after five years through ten years	11,842
Due after ten years	2,620
Mortgage-backed securities	316,507
Securities available for sale	460,797	451,770
Held to maturity, Amortized Cost
Due in one year or less	658
Due after one year through five years	5,609
Due after five years through ten years	7,380
Due after ten years	1,112
Mortgage-backed securities	65,704
Amortized Cost	80,463	43,714
Held to maturity, Estimated Fair Value
Due in one year or less	655
Due after one year through five years	5,559
Due after five years through ten years	7,241
Due after ten years	1,073
Mortgage-backed securities	65,111
Held to maturity, fair value	$ 79,639	$ 43,441

Investments - Schedule of Unrea

Investments - Schedule of Unrealized Loss on Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 289,095	$ 191,428
Less than 12 months, unrealized losses	(4,492)	(2,062)
12 months or more, fair value	16,436	30,415
12 months or more, unrealized losses	(813)	(1,117)
Total, fair value	305,531	221,843
Total, unrealized losses	(5,305)	(3,179)
Obligations of states and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	21,361	2,199
Less than 12 months, unrealized losses	408	12
12 months or more, fair value	3,553	9,395
12 months or more, unrealized losses	320	380
Total, fair value	24,914	11,594
Total, unrealized losses	728	392
Agency mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	267,734	189,229
Less than 12 months, unrealized losses	4,084	2,050
12 months or more, fair value	12,883	21,020
12 months or more, unrealized losses	493	737
Total, fair value	280,617	210,249
Total, unrealized losses	$ 4,577	$ 2,787

Investments - Schedule of Reali

Investments - Schedule of Realized Gain (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Gross gains realized	$ 86	$ 63	$ 0
Gross losses realized	0	(40)	0
Proceeds from sales	$ 2,493	$ 41,069	$ 0

Investments - Narrative (Detail

Investments - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Other investments, at cost	$ 14,840	$ 17,455
Maximum percentage of shareholders' equity security holdings held of one issuer	10.00%	10.00%
Available-for-sale securities pledged as collateral, fair value	$ 407,300	$ 334,400
Mortgage-backed securities, weighted average life	4 years
Des Moines
Schedule of Available-for-sale Securities [Line Items]
Other investments, at cost	$ 4,400

Portfolio Loans - Summary of Po

Portfolio Loans - Summary of Portfolio Loans by Category (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	$ 3,118,392	$ 2,750,737
Non-Covered Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans, before unearned loan (fees) costs	3,119,154	2,750,446
Unearned loan (fees) costs, net	(762)	291
Portfolio loans	3,118,392	2,750,737
Non-Covered Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans, before unearned loan (fees) costs	1,632,714	1,484,327
Non-Covered Loans | CRE - investor owned
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans, before unearned loan (fees) costs	544,808	428,064
Non-Covered Loans | CRE - owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans, before unearned loan (fees) costs	350,148	342,959
Non-Covered Loans | Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans, before unearned loan (fees) costs	194,542	161,061
Non-Covered Loans | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans, before unearned loan (fees) costs	240,760	196,498
Non-Covered Loans | Total real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans, before unearned loan (fees) costs	1,330,258	1,128,582
Non-Covered Loans | Consumer and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans, before unearned loan (fees) costs	156,182	137,537
Portfolio loans	$ 155,420	$ 137,828

Portfolio Loans - Summary of Lo

Portfolio Loans - Summary of Loans to Executive Officers and Directors (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Loans and Leases Receivable, Related Parties [Roll Forward]
Balance at beginning of year	$ 4,394	$ 13,513	$ 11,752
New loans and advances	11,539	641	11,796
Payments and other reductions	(527)	(9,760)	(10,035)
Balance at end of year	$ 15,406	$ 4,394	$ 13,513

Portfolio Loans - Summary of Al

Portfolio Loans - Summary of Allowance for Loan Losses by Portfolio Class and Category (Details) - Non-Covered Loans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Loan Losses [Roll Forward]
Balance, beginning of year	$ 33,441	$ 30,185	$ 27,289
Provision (provision reversal)	5,551	4,872	4,409
Losses charged off	4,335	6,091	5,556
Recoveries	2,908	4,475	4,043
Balance, end of year	37,565	33,441	30,185
Commercial and industrial
Allowance for Loan Losses [Roll Forward]
Balance, beginning of year	22,056	16,983	12,246
Provision (provision reversal)	6,569	6,976	6,707
Losses charged off	(2,303)	(3,699)	(3,738)
Recoveries	674	1,796	1,768
Balance, end of year	26,996	22,056	16,983
CRE - investor owned
Allowance for Loan Losses [Roll Forward]
Balance, beginning of year	3,484	4,382	6,600
Provision (provision reversal)	(11)	(303)	(2,063)
Losses charged off	(95)	(664)	(250)
Recoveries	42	69	95
Balance, end of year	3,420	3,484	4,382
CRE - owner occupied
Allowance for Loan Losses [Roll Forward]
Balance, beginning of year	2,969	3,135	4,096
Provision (provision reversal)	(1,202)	(1,626)	(1,517)
Losses charged off	0	(38)	(450)
Recoveries	1,123	1,498	1,006
Balance, end of year	2,890	2,969	3,135
Construction and land development
Allowance for Loan Losses [Roll Forward]
Balance, beginning of year	1,704	1,715	2,136
Provision (provision reversal)	(1,334)	(335)	(322)
Losses charged off	0	(350)	(905)
Recoveries	934	674	806
Balance, end of year	1,304	1,704	1,715
Residential real estate
Allowance for Loan Losses [Roll Forward]
Balance, beginning of year	1,796	2,830	2,019
Provision (provision reversal)	129	(58)	525
Losses charged off	(25)	(1,313)	(48)
Recoveries	123	337	334
Balance, end of year	2,023	1,796	2,830
Consumer and other
Allowance for Loan Losses [Roll Forward]
Balance, beginning of year	1,432	1,140	192
Provision (provision reversal)	1,400	218	1,079
Losses charged off	(1,912)	(27)	(165)
Recoveries	12	101	34
Balance, end of year	$ 932	$ 1,432	$ 1,140

Portfolio Loans - Summary of Re

Portfolio Loans - Summary of Recorded Investment in Portfolio Loans by Class and Category Based on Impairment Method (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Loans - Ending balance:
Portfolio loans	$ 3,118,392	$ 2,750,737
Non-Covered Loans
Balance December 31, 2016
Individually evaluated for impairment	3,064	2,335
Collectively evaluated for impairment	34,501	31,106
Total	37,565	33,441	$ 30,185	$ 27,289
Loans - Ending balance:
Individually evaluated for impairment	16,772	10,878
Collectively evaluated for impairment	3,101,620	2,739,859
Portfolio loans	3,118,392	2,750,737
Total	3,119,154	2,750,446
Non-Covered Loans | Commercial and industrial
Balance December 31, 2016
Individually evaluated for impairment	2,909	1,953
Collectively evaluated for impairment	24,087	20,103
Total	26,996	22,056	16,983	12,246
Loans - Ending balance:
Individually evaluated for impairment	12,523	4,514
Collectively evaluated for impairment	1,620,191	1,479,813
Total	1,632,714	1,484,327
Non-Covered Loans | CRE - investor owned
Balance December 31, 2016
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	3,420	3,484
Total	3,420	3,484	4,382	6,600
Loans - Ending balance:
Individually evaluated for impairment	430	921
Collectively evaluated for impairment	544,378	427,143
Total	544,808	428,064
Non-Covered Loans | CRE - owner occupied
Balance December 31, 2016
Individually evaluated for impairment	0	6
Collectively evaluated for impairment	2,890	2,963
Total	2,890	2,969	3,135	4,096
Loans - Ending balance:
Individually evaluated for impairment	1,854	1,962
Collectively evaluated for impairment	348,294	340,997
Total	350,148	342,959
Non-Covered Loans | Construction and land development
Balance December 31, 2016
Individually evaluated for impairment	155	369
Collectively evaluated for impairment	1,149	1,335
Total	1,304	1,704	1,715	2,136
Loans - Ending balance:
Individually evaluated for impairment	1,903	2,800
Collectively evaluated for impairment	192,639	158,261
Total	194,542	161,061
Non-Covered Loans | Residential real estate
Balance December 31, 2016
Individually evaluated for impairment	0	7
Collectively evaluated for impairment	2,023	1,789
Total	2,023	1,796	2,830	2,019
Loans - Ending balance:
Individually evaluated for impairment	62	681
Collectively evaluated for impairment	240,698	195,817
Total	240,760	196,498
Non-Covered Loans | Consumer and other
Balance December 31, 2016
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	932	1,432
Total	932	1,432	$ 1,140	$ 192
Loans - Ending balance:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	155,420	137,828
Portfolio loans	155,420	137,828
Total	$ 156,182	$ 137,537

Portfolio Loans - Summary of 64

Portfolio Loans - Summary of Portfolio Loans Individually Evaluated for Impairment by Category (Details) - Non-Covered Loans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	$ 15,057	$ 11,864
Recorded Investment With No Allowance	3,241	5,072
Recorded Investment With Allowance	12,150	4,915
Total Recorded Investment	15,391	9,987
Related Allowance	3,064	2,335
Average Recorded Investment	7,366	11,924
Commercial and industrial
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	12,341	5,554
Recorded Investment With No Allowance	566	509
Recorded Investment With Allowance	11,791	4,204
Total Recorded Investment	12,357	4,713
Related Allowance	2,909	1,953
Average Recorded Investment	4,489	6,970
CRE - investor owned
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	525	927
Recorded Investment With No Allowance	435	927
Recorded Investment With Allowance	0	0
Total Recorded Investment	435	927
Related Allowance	0	0
Average Recorded Investment	668	970
CRE - owner occupied
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	225	329
Recorded Investment With No Allowance	231	85
Recorded Investment With Allowance	0	113
Total Recorded Investment	231	198
Related Allowance	0	6
Average Recorded Investment	227	301
Construction and land development
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	1,904	4,349
Recorded Investment With No Allowance	1,947	2,914
Recorded Investment With Allowance	359	530
Total Recorded Investment	2,306	3,444
Related Allowance	155	369
Average Recorded Investment	1,918	3,001
Residential real estate
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	62	705
Recorded Investment With No Allowance	62	637
Recorded Investment With Allowance	0	68
Total Recorded Investment	62	705
Related Allowance	0	7
Average Recorded Investment	64	682
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

Portfolio Loans - Summary of Pa

Portfolio Loans - Summary of Past Due and Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Receivables [Abstract]
Total interest income that would have been recognized under original terms on impaired loans	$ 1,079	$ 1,038	$ 1,013
Total cash received and recognized as interest income on impaired loans	251	226	118
Total interest income recognized on impaired loans still accruing	$ 155	$ 36	$ 39

Portfolio Loans - Narrative (De

Portfolio Loans - Narrative (Details) $ in Millions	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
Specific reserves on restructured loans	$ 0.7
Unadvanced Commitment on Impaired Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Estimated losses attributable to unadvanced commitments on impaired loans	$ 0.3

Portfolio Loans - Summary of 67

Portfolio Loans - Summary of Recorded Investment in Impaired Portfolio Loans by Category (Details) - Non-Covered Loans - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	$ 13,060	$ 9,680
Restructured	2,331	307
Total Recorded Investment	15,391	9,987
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	10,046	4,406
Restructured	2,311	307
Total Recorded Investment	12,357	4,713
CRE - investor owned
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	435	927
Restructured	0	0
Total Recorded Investment	435	927
CRE - owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	231	198
Restructured	0	0
Total Recorded Investment	231	198
Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	2,286	3,444
Restructured	20	0
Total Recorded Investment	2,306	3,444
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	62	705
Restructured	0	0
Total Recorded Investment	62	705
Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	0
Restructured	0	0
Total Recorded Investment	$ 0	$ 0

Portfolio Loans - Summary of 68

Portfolio Loans - Summary of Recorded Investment by Category for Portfolio Loans Restructured (Details) - Non-Covered Loans $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)loan	Dec. 31, 2015USD ($)loan
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	7	1
Pre-Modification Outstanding Recorded Balance	$ 12,395	$ 303
Post-Modification Outstanding Recorded Balance	$ 12,395	$ 303
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	4	1
Pre-Modification Outstanding Recorded Balance	$ 12,114	$ 303
Post-Modification Outstanding Recorded Balance	$ 12,114	$ 303
CRE - investor owned
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	1	0
Pre-Modification Outstanding Recorded Balance	$ 248	$ 0
Post-Modification Outstanding Recorded Balance	$ 248	$ 0
CRE - owner occupied
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	1	0
Pre-Modification Outstanding Recorded Balance	$ 13	$ 0
Post-Modification Outstanding Recorded Balance	$ 13	$ 0
Construction and land development
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	1	0
Pre-Modification Outstanding Recorded Balance	$ 20	$ 0
Post-Modification Outstanding Recorded Balance	$ 20	$ 0
Residential real estate
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	0
Pre-Modification Outstanding Recorded Balance	$ 0	$ 0
Post-Modification Outstanding Recorded Balance	$ 0	$ 0
Consumer and other
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	0
Pre-Modification Outstanding Recorded Balance	$ 0	$ 0
Post-Modification Outstanding Recorded Balance	$ 0	$ 0

Portfolio Loans - Summary of Ag

Portfolio Loans - Summary of Aging of Recorded Investment in Past Due Portfolio Loans by Portfolio Class and Category (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Portfolio loans	$ 3,118,392	$ 2,750,737
Non-Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	999	1,537
Financing Receivable, Recorded Investment, 90 Days Past Due	2,099	4,026
Total Past Due	3,098	5,563
Current	3,115,294	2,745,174
Total	3,119,154	2,750,446
Portfolio loans	3,118,392	2,750,737
Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	334	505
Financing Receivable, Recorded Investment, 90 Days Past Due	171	888
Total Past Due	505	1,393
Current	1,632,209	1,482,934
Total	1,632,714	1,484,327
Non-Covered Loans | CRE - investor owned
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	464
Financing Receivable, Recorded Investment, 90 Days Past Due	175	0
Total Past Due	175	464
Current	544,633	427,600
Total	544,808	428,064
Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	212	94
Financing Receivable, Recorded Investment, 90 Days Past Due	225	184
Total Past Due	437	278
Current	349,711	342,681
Total	350,148	342,959
Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	355	384
Financing Receivable, Recorded Investment, 90 Days Past Due	1,528	2,273
Total Past Due	1,883	2,657
Current	192,659	158,404
Total	194,542	161,061
Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	91	70
Financing Receivable, Recorded Investment, 90 Days Past Due	0	681
Total Past Due	91	751
Current	240,669	195,747
Total	240,760	196,498
Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	7	20
Financing Receivable, Recorded Investment, 90 Days Past Due	0	0
Total Past Due	7	20
Current	155,413	137,808
Total	156,182	137,537
Portfolio loans	$ 155,420	$ 137,828

Portfolio Loans - Summary of 70

Portfolio Loans - Summary of Recorded Investment by Risk Category of Portfolio Loans by Portfolio Class and Category (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	$ 3,118,392	$ 2,750,737
Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Total	3,119,154	2,750,446
Portfolio loans	3,118,392	2,750,737
Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	1,632,714	1,484,327
Non-Covered Loans | CRE - investor owned
Financing Receivable, Recorded Investment [Line Items]
Total	544,808	428,064
Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Total	350,148	342,959
Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total	194,542	161,061
Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Total	240,760	196,498
Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Total	156,182	137,537
Portfolio loans	155,420	137,828
Pass (1-6) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	2,909,234	2,541,405
Pass (1-6) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	1,499,114	1,356,864
Pass (1-6) | Non-Covered Loans | CRE - investor owned
Financing Receivable, Recorded Investment [Line Items]
Total	306,658	314,791
Pass (1-6) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Total	530,494	403,820
Pass (1-6) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total	185,505	146,601
Pass (1-6) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Total	233,479	188,269
Pass (1-6) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	153,984	131,060
Watch (7) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	116,686	149,938
Watch (7) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	57,416	90,370
Watch (7) | Non-Covered Loans | CRE - investor owned
Financing Receivable, Recorded Investment [Line Items]
Total	39,249	24,727
Watch (7) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Total	10,449	18,868
Watch (7) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total	6,575	10,114
Watch (7) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Total	2,997	5,138
Watch (7) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	0	721
Substandard (8) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	92,472	59,394
Substandard (8) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total	76,184	37,093
Substandard (8) | Non-Covered Loans | CRE - investor owned
Financing Receivable, Recorded Investment [Line Items]
Total	4,241	3,441
Substandard (8) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Total	3,865	5,376
Substandard (8) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total	2,462	4,346
Substandard (8) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Total	4,284	3,091
Substandard (8) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	$ 1,436	$ 6,047

Purchased Credit Impaired ("P71

Purchased Credit Impaired ("PCI") Loans - Summary of PCI Loans by Category (Details) - Covered Loans $ in Thousands	Dec. 31, 2016USD ($)rating	Dec. 31, 2015USD ($)rating
Covered Loans [Line Items]
Recorded Investment PCI Loans	$ 39,769	$ 74,758
Commercial and industrial
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	5.87	6.70
Recorded Investment PCI Loans	$ 3,523	$ 3,863
CRE - investor owned
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	6.95	6.98
Recorded Investment PCI Loans	$ 8,162	$ 25,272
CRE - owner occupied
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	6.39	6.30
Recorded Investment PCI Loans	$ 11,863	$ 19,414
Construction and land development
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	5.80	6.28
Recorded Investment PCI Loans	$ 4,365	$ 6,838
Residential real estate
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	5.64	5.44
Recorded Investment PCI Loans	$ 11,792	$ 19,287
Total real estate loans
Covered Loans [Line Items]
Recorded Investment PCI Loans	$ 36,182	$ 70,811
Consumer and other
Covered Loans [Line Items]
Weighted- Average Risk Rating1 | rating	1.64	1.89
Recorded Investment PCI Loans	$ 64	$ 84

Purchased Credit Impaired ("P72

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	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	$ 169	$ 4,671
90 or More Days Past Due	51	3,791
Total Past Due	220	8,462
Current	39,549	66,296
Total	39,769	74,758
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	0
90 or More Days Past Due	0	0
Total Past Due	0	0
Current	3,523	3,863
Total	3,523	3,863
CRE - investor owned
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	2,342
90 or More Days Past Due	0	3,661
Total Past Due	0	6,003
Current	8,162	19,269
Total	8,162	25,272
CRE - owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	731
90 or More Days Past Due	0	0
Total Past Due	0	731
Current	11,863	18,683
Total	11,863	19,414
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	4,365	6,838
Total	4,365	6,838
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	169	1,594
90 or More Days Past Due	51	130
Total Past Due	220	1,724
Current	11,572	17,563
Total	11,792	19,287
Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	4
90 or More Days Past Due	0	0
Total Past Due	0	4
Current	64	80
Total	$ 64	$ 84

Purchased Credit Impaired ("P73

Purchased Credit Impaired ("PCI") Loans - Rollforward of PCI Loans, Net of Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 64,583	$ 83,693
Principal reductions and interest payments	(25,669)	(24,441)
Accretion of loan discount	6,155	10,775
Changes in contractual and expected cash flows due to remeasurement	12,452	14,707
Reductions due to disposals	(23,596)	(20,151)
Balance at end of period	33,925	64,583
Contractual Cashflows
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	116,689	178,145
Principal reductions and interest payments	(25,669)	(24,441)
Accretion of loan discount	0	0
Changes in contractual and expected cash flows due to remeasurement	11,718	(3,574)
Reductions due to disposals	(36,735)	(33,441)
Balance at end of period	66,003	116,689
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	26,765	65,719
Principal reductions and interest payments	0	0
Accretion of loan discount	0	0
Changes in contractual and expected cash flows due to remeasurement	766	(30,413)
Reductions due to disposals	(8,629)	(8,541)
Balance at end of period	18,902	26,765
Accretable Yield
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	25,341	28,733
Principal reductions and interest payments	0	0
Accretion of loan discount	6,155	10,775
Changes in contractual and expected cash flows due to remeasurement	(1,500)	12,132
Reductions due to disposals	(4,510)	(4,749)
Balance at end of period	$ 13,176	$ 25,341

Purchased Credit Impaired ("P74

Purchased Credit Impaired ("PCI") Loans - Summary of FDIC Loss Share Receivable (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Financing Receivable, Impaired [Line Items]
Total Cash received from FDIC for covered assets	$ 3,528
Reductions for loss share termination	(5,922)
FDIC Indemnification Asset [Roll Forward]
Balance at beginning of period	15,866
FDIC reimbursable recoveries	(1,386)
Amortization, net	(2,293)
Loan impairment reversal	(1,113)
Reductions for payments on covered assets in excess of expected cash flows	(1,624)
Balance at end of period	$ 0

Purchased Credit Impaired ("P75

Purchased Credit Impaired ("PCI") Loans - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
FDIC proceeds from loss share termination [Line Items]
Removal of remaining clawback liability, FDIC loss share termination		$ 3,500
Removal of remaining FDIC receivable, FDIC loss share termination		7,200
One-time pretax charge		2,400
PCI loans outstanding	$ 54,600	98,600
Net payment received from FDIC for loss share termination		1,300
Expense recorded related to Clawback Liability	$ 0	$ 760	$ 1,201

Derivative Financial Instrume76

Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivative Liability, Notional Amount	$ 3,500	$ 3,500
Pledged cash as collateral in connection with interest rate swap agreements	700	1,300
Non-designated hedging instruments | Client-Related | Interest rate swap contracts
Summary of Derivative Instruments [Abstract]
Notional Amount	124,322	153,630
Non-designated hedging instruments | Client-Related | Foreign Exchange Forward [Member]
Summary of Derivative Instruments [Abstract]
Notional Amount	3,034	0
Non-designated hedging instruments | Client-Related | Other Assets | Interest rate swap contracts
Derivative [Line Items]
Unrealized Gain Derivative Instruments	982
Summary of Derivative Instruments [Abstract]
Derivative Asset, Fair Value, Gross Asset	982	1,155
Non-designated hedging instruments | Client-Related | Other Assets | Foreign Exchange Forward [Member]
Summary of Derivative Instruments [Abstract]
Derivative Asset, Fair Value, Gross Asset	3,034	0
Non-designated hedging instruments | Client-Related | Other Liabilities | Interest rate swap contracts
Summary of Derivative Instruments [Abstract]
Liability derivatives (other liabilities), fair value	982	1,155
Non-designated hedging instruments | Client-Related | Other Liabilities | Foreign Exchange Forward [Member]
Summary of Derivative Instruments [Abstract]
Liability derivatives (other liabilities), fair value	$ 3,034	$ 0

Fixed Assets - Summary of Fixed

Fixed Assets - Summary of Fixed Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Land	$ 3,103	$ 3,103
Buildings and leasehold improvements	18,054	17,837
Furniture, fixtures and equipment	6,136	4,892
Capitalized software	1,305	1,030
Fixed assets, gross	28,598	26,862
Less accumulated depreciation and amortization	13,688	12,020
Fixed assets, net	$ 14,910	$ 14,842

Fixed Assets - Narrative (Detai

Fixed Assets - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Lease Abandonment Expense	$ 0.5	$ 0.1	$ 0.4
Depreciation and amortization	2.4	2	2.2
Rent expense	3.1	3.1	2.9
Sublease rental income	0.1	$ 0.1	$ 0.2
Discontinued Operations, Disposed of by Means Other than Sale, Abandonment [Member]
Lease Abandonment Liability	$ 1.1

Fixed Assets - Future Aggregate

Fixed Assets - Future Aggregate Minimum Rental Commitments (Details) $ in Thousands	Dec. 31, 2016USD ($)
Future Aggregate Minimum Rental Commitments
2,017	$ 2,797
2,018	2,684
2,019	2,676
2,020	2,637
2,021	2,642
Thereafter	6,667
Total	$ 20,103

Goodwill and Intangible Asset80

Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 30,334	$ 30,334
Finite-lived intangible assets useful life	10 years	10 years
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 924	$ 1,089	$ 1,254
Core deposit intangible, net, end of year	$ 2,151
Core Deposits [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Finite-lived intangible assets useful life	10 years
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 924	1,089	$ 1,254
Gross core deposit intangible balance, beginning of year	9,060	9,060
Accumulated amortization	(6,909)	(5,985)
Core deposit intangible, net, end of year	$ 2,151	$ 3,075

Goodwill and Intangible Asset81

Goodwill and Intangible Assets - Expected Amortization Schedule for the Core Deposit Intangible (Details) $ in Thousands	Dec. 31, 2016USD ($)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2,015	$ 760
2,016	595
2,017	430
2,018	265
After 2,021	101
Core deposit intangible, net, end of year	$ 2,151

Maturity of Certificates of D82

Maturity of Certificates of Deposit (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Brokered
Less than 1 year	$ 117,145
Greater than 1 year and less than 2 years	0
Greater than 2 years and less than 3 years	0
Greater than 3 years and less than 4 years	0
Greater than 4 years and less than 5 years	0
Brokered	117,145	$ 39,573
Other
Less than 1 year	197,262
Greater than 1 year and less than 2 years	67,909
Greater than 2 years and less than 3 years	28,806
Greater than 3 years and less than 4 years	45,341
Greater than 4 years and less than 5 years	16,696
Other	356,014	$ 316,615
Total
Less than 1 year	314,407
Greater than 1 year and less than 2 years	67,909
Greater than 2 years and less than 3 years	28,806
Greater than 3 years and less than 4 years	45,341
Greater than 4 years and less than 5 years	16,696
Total Time Deposits	473,159
Time Deposits, $250,000 or More	$ 124,800

Subordinated Debentures (Detail

Subordinated Debentures (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)shares	Dec. 31, 2014shares	Nov. 01, 2021	Nov. 01, 2016USD ($)
Subordinated Borrowing [Line Items]
Investments trust preferred securities	$ 1,700
Number of Unconsolidated Statutory Business Trusts	8
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	$ 105,540	$ 56,807
Debt Issuance Cost	$ (1,267)	$ 0
Conversion of subordinated debt into common stock (in shares) | shares	0	0	287,852
Senior Subordinated Notes [Member]
Subordinated Borrowing [Line Items]
Junior Subordinated Notes					$ 50,000
Subordinated Notes, Redemption Price				100.00%
Trust preferred securities [Member]
Subordinated Borrowing [Line Items]
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	$ 56,807	$ 56,807
Trust preferred securities [Member] | EFSC Clayco Statutory Trust I
Subordinated Borrowing [Line Items]
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	$ 3,196	3,196
Maturity Date	Dec. 17, 2033
Call Date	Dec. 17, 2008
Description of variable rate	3 Month LIBOR
Floating interest rate	2.85%
Trust preferred securities [Member] | EFSC Capital Trust II
Subordinated Borrowing [Line Items]
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	$ 5,155	5,155
Maturity Date	Jun. 17, 2034
Call Date	Jun. 17, 2009
Description of variable rate	3 Month LIBOR
Floating interest rate	2.65%
Trust preferred securities [Member] | EFSC Statutory Trust III
Subordinated Borrowing [Line Items]
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	$ 11,341	11,341
Maturity Date	Dec. 15, 2034
Call Date	Dec. 15, 2009
Description of variable rate	3 Month LIBOR
Floating interest rate	1.97%
Trust preferred securities [Member] | EFSC Clayco Statutory Trust II
Subordinated Borrowing [Line Items]
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	$ 4,124	4,124
Maturity Date	Sep. 15, 2035
Call Date	Sep. 15, 2010
Description of variable rate	3 Month LIBOR
Floating interest rate	1.83%
Trust preferred securities [Member] | EFSC Statutory Trust IV
Subordinated Borrowing [Line Items]
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	$ 10,310	10,310
Maturity Date	Dec. 15, 2035
Call Date	Dec. 15, 2010
Description of variable rate	3 Month LIBOR
Floating interest rate	1.44%
Trust preferred securities [Member] | EFSC Statutory Trust V
Subordinated Borrowing [Line Items]
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	$ 4,124	4,124
Maturity Date	Sep. 15, 2036
Call Date	Sep. 15, 2011
Description of variable rate	3 Month LIBOR
Floating interest rate	1.60%
Trust preferred securities [Member] | EFSC Capital Trust VI
Subordinated Borrowing [Line Items]
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	$ 14,433	14,433
Maturity Date	Mar. 30, 2037
Call Date	Mar. 30, 2012
Description of variable rate	3 Month LIBOR
Floating interest rate	1.60%
Trust preferred securities [Member] | EFSC Capital Trust VII
Subordinated Borrowing [Line Items]
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	$ 4,124	4,124
Maturity Date	Dec. 15, 2037
Call Date	Dec. 15, 2012
Description of variable rate	3 Month LIBOR
Floating interest rate	2.25%
Trust preferred securities [Member] | EFSC Capital Trust VIII
Subordinated Borrowing [Line Items]
Fixed interest rate	9.00%
Senior Subordinated Notes [Member]
Subordinated Borrowing [Line Items]
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	$ 50,000	0
Debt Issuance Cost	(1,267)	0
Subordinated notes, net of issuance costs	$ 48,733	$ 0
Maturity Date	Nov. 1, 2026
Call Date	Nov. 1, 2021
Floating interest rate	3.387%
Fixed interest rate	4.75%

Federal Home Loan Bank Advanc84

Federal Home Loan Bank Advances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016
Federal Home Loan Bank, Advances, Branch of FHLB [Line Items]
Carrying value of the loans pledged	$ 110,000		$ 0
Prepayment of FHLB advances		$ 50,000
Weighted average interest rate		3.17%
Maturity (in years)		3 years
Prepayment penalty	2,900
Short term advances outstanding	$ 110,000		$ 0
Weighted average interest rate on short term advances	0.00%		0.00%
Collateral used to secure confirming letters of credit			$ 26,700
Weighted Rate
Federal Home Loan Bank, Advances, Maturities Summary, One to Five Years	$ 0		$ 0
Federal Home Loan Bank Advances, Maturities Summary, Average Interest Rate of Amounts Due in One to Five Years of Balance Sheet Date	0.00%		0.00%
Federal Home Loan Bank, Advances, Maturities Summary, Average Interst Rate of Amounts	0.00%		0.00%
Des Moines
Federal Home Loan Bank, Advances, Branch of FHLB [Line Items]
Carrying value of the loans pledged	$ 633,500		$ 773,500
Availability under the secured line of credit			439,700
Investment in capital stock			$ 4,400

Other Borrowings and Notes Pa85

Other Borrowings and Notes Payable (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Feb. 23, 2016	Nov. 06, 2012
Debt Instrument [Line Items]
Securities sold under repurchase agreements	$ 276,980,000	$ 270,326,000
Total	276,980,000	270,326,000
Unsecured Lines of Credit			$ 20,000,000
Line of Credit
Debt Instrument [Line Items]
Remaining borrowing capacity	933,900,000
Aggregate of pledge secured by certain eligible loans	1,147,200,000
Amount withdrawn	0
Other Borrowings
Debt Instrument [Line Items]
Average balance during the year	206,643,000	195,328,000
Maximum balance outstanding at any month-end	$ 276,980,000	$ 270,326,000
Average interest rate during the year	0.19%	0.22%
Average interest rate at December 31	0.18%	0.16%
Unsecured Term Loan
Debt Instrument [Line Items]
Average balance during the year		$ 4,509,000
Maximum balance outstanding at any month-end		$ 5,700,000
Average interest rate during the year		3.01%
Average interest rate at December 31		0.00%
Unsecured term loan, face amount				$ 12,000,000
Term Loan		$ 0

Regulatory Matters (Details)

Regulatory Matters (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Enterprise Financial Services Corp [Member]
Total Capital (to Risk Weighted Assets) [Abstract]
Actual, Amount	$ 506,349	$ 418,367
Actual, Ratio	13.48%	11.85%
For Capital Adequacy Purposes, Amount	$ 300,573	$ 282,442
For Capital Adequacy Purposes, Ratio	8.00%	8.00%
To Be Well Capitalized Under Applicable Action Provisions, Amount	$ 0	$ 0
To Be Well Capitalized Under Applicable Action Provisions, Ratio	0.00%	0.00%
Tier 1 Capital (to Risk Weighted Assets) [Abstract]
Actual, Amount	$ 412,865	$ 374,676
Actual, Ratio	10.99%	10.61%
For Capital Adequacy Purposes, Amount	$ 225,430	$ 211,831
For Capital Adequacy Purposes, Ratio	6.00%	6.00%
To Be Well Capitalized Under Applicable Action Provisions, Amount	$ 0	$ 0
To Be Well Capitalized Under Applicable Action Provisions, Ratio	0.00%	0.00%
Tier One Common Equity Capital	$ 357,729	$ 319,553
Tier One Common Equity Capital to Risk Weighted Assets	9.52%	9.05%
Tier One Common Equity Capital Required for Capital Adequacy	$ 169,072	$ 158,873
Tier One Common Equity Capital Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Tier One Common Equity Capital Required to be Well Capitalized	$ 0	$ 0
Tier One Common Equity Capital Required to be Well Capitalized to Risk Weighted Assets	0.00%	0.00%
Tier 1 Capital (to Average Assets) [Abstract]
Actual, Amount	$ 412,865	$ 374,676
Actual, Ratio	10.42%	10.71%
For Capital Adequacy Purposes, Amount	$ 158,480	$ 139,893
For Capital Adequacy Purposes, Ratio	4.00%	4.00%
To Be Well Capitalized Under Applicable Action Provisions, Amount	$ 0	$ 0
To Be Well Capitalized Under Applicable Action Provisions, Ratio	0.00%	0.00%
Enterprise Bank and Trust [Member]
Total Capital (to Risk Weighted Assets) [Abstract]
Actual, Amount	$ 430,981	$ 386,531
Actual, Ratio	11.53%	10.98%
For Capital Adequacy Purposes, Amount	$ 298,982	$ 281,632
For Capital Adequacy Purposes, Ratio	8.00%	8.00%
To Be Well Capitalized Under Applicable Action Provisions, Amount	$ 373,728	$ 352,040
To Be Well Capitalized Under Applicable Action Provisions, Ratio	10.00%	10.00%
Tier 1 Capital (to Risk Weighted Assets) [Abstract]
Actual, Amount	$ 387,497	$ 342,840
Actual, Ratio	10.37%	9.74%
For Capital Adequacy Purposes, Amount	$ 224,237	$ 211,224
For Capital Adequacy Purposes, Ratio	6.00%	6.00%
To Be Well Capitalized Under Applicable Action Provisions, Amount	$ 298,982	$ 281,632
To Be Well Capitalized Under Applicable Action Provisions, Ratio	8.00%	8.00%
Tier One Common Equity Capital	$ 387,461	$ 342,816
Tier One Common Equity Capital to Risk Weighted Assets	10.37%	9.74%
Tier One Common Equity Capital Required for Capital Adequacy	$ 168,178	$ 158,418
Tier One Common Equity Capital Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Tier One Common Equity Capital Required to be Well Capitalized	$ 242,923	$ 228,826
Tier One Common Equity Capital Required to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
Tier 1 Capital (to Average Assets) [Abstract]
Actual, Amount	$ 387,497	$ 342,840
Actual, Ratio	9.81%	9.84%
For Capital Adequacy Purposes, Amount	$ 157,933	$ 139,311
For Capital Adequacy Purposes, Ratio	4.00%	4.00%
To Be Well Capitalized Under Applicable Action Provisions, Amount	$ 197,417	$ 174,138
To Be Well Capitalized Under Applicable Action Provisions, Ratio	5.00%	5.00%

Compensation Plans - Narrative

Compensation Plans - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended			12 Months Ended
	Feb. 28, 2017	Jan. 31, 2016	Feb. 28, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant				218,173
Share-based compensation expense				$ 3,400	$ 3,600	$ 2,900
Tax benefit from compensation expense				$ 1,300	400	$ 200
Award vesting period						3 years
Number of shares issued upon completion of performance cycle		159,094	122,470
Employee minimum age to participate in plan				21 years
Company contributions, amount charged to expense				$ 1,700	1,600	$ 1,400
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term				10 years
Stock Appreciation Rights (SSARs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				5 years
Contractual term				10 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense				$ 850	725	945
Total unrecognized compensation cost (less than)				$ 1,084	942	1,462
Number of shares issued				32,913
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense				$ 0	$ 200	$ 100
Number of shares issued				0	14,110	34,034
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense				$ 2,500	$ 2,700	$ 1,800
Share-based compensation expense, retiring executive				$ 200
Award vesting period						3 years
Minimum | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				3 years
Minimum | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				2 years
Minimum | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				2 years
Maximum | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				5 years
Maximum | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				5 years
Maximum | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				5 years
Stock Plan for Non-Management Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant				29,694
Share-based compensation expense				$ 407	$ 373	$ 329
Number of shares authorized				200,000
Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued upon completion of performance cycle	118,519

Compensation Plans - Schedule o

Compensation Plans - Schedule of Various Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 3,400	$ 3,600	$ 2,900
Weighted average fair value (usd per share)	$ 25,260	$ 19,210
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 850	$ 725	945
Total fair value at vesting date	2,275	809	913
Total unrecognized compensation cost for nonvested stock units	$ 1,084	$ 942	$ 1,462
Expected years to recognize unearned compensation	1 year 7 months	1 year 8 months	2 years 8 months 12 days
Stock Options and SSARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 0	$ 50	$ 103
Intrinsic value of option exercises on date of exercise	1,156	74	226
Cash received from the exercise of stock options	87	126	149
Stock Plan for Non-Management Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 407	$ 373	$ 329
Number of shares issued	12,528,000	16,283,000	23,135,000
Weighted average fair value (usd per share)	$ 31.25	$ 24.43	$ 19.20

Compensation Plans - Schedule89

Compensation Plans - Schedule of Employee Stock Options and SSARs Activity (Details) - Stock Options and SSARs	12 Months Ended
	Dec. 31, 2016USD ($)$ / sharesshares
Shares
Outstanding at beginning of period (in shares) | shares	388,103
Granted (in shares) | shares	0
Exercised (in shares) | shares	(117,857)
Forfeited (in shares) | shares	0
Outstanding at end of period (in shares) | shares	270,246
Exercisable (in shares) | shares	270,246
Weighted Average Exercise Price
Outstanding at beginning of period (usd per share) | $ / shares	$ 19.15
Granted (usd per share) | $ / shares	0
Exercised (usd per share) | $ / shares	19.85
Forfeited (usd per share) | $ / shares	0
Outstanding at end of period (usd per share) | $ / shares	18.85
Exercisable (usd per share) | $ / shares	$ 18.85
Additional Disclosures
Outstanding, weighted average remaining contractual term	1 year 11 months
Exercisable, weighted average remaining contractual term	1 year 11 months
Outstanding, aggregate intrinsic value | $	$ 6,527
Exercisable, aggregate intrinsic value | $	$ 6,527

Compensation Plans - Summary of

Compensation Plans - Summary of Restricted Stock Units Activity (Details) - Restricted Stock Units (RSUs)	12 Months Ended
	Dec. 31, 2016$ / sharesshares
Shares
Outstanding, beginning of period (in shares) | shares	86,354
Granted (in shares) | shares	32,913
Vested (in shares) | shares	(56,089)
Forfeited (in shares) | shares	(4,480)
Outstanding, end of period (in shares) | shares	58,698
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (usd per share) | $ / shares	$ 14.31
Granted (usd per share) | $ / shares	29.71
Vested (usd per share) | $ / shares	14.25
Forfeited (usd per share) | $ / shares	13.51
Outstanding, end of period (usd per share) | $ / shares	$ 23.06

Compensation Plans Outstanding

Compensation Plans Outstanding Longer Term Incentive Awards (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Outstanding Long Term Incentive Awards [Line Items]
Target Shares Issuable as Long Term Incentive Awards	$ 95,694	$ 113,903
Maximum Shares Issuable as Long Term Incentive Awards	117,681	142,292
Unrecognized Compensation Cost - Long Term Incentives	$ 1,928,804	$ 1,139,778
Share-based Compensation Arrangement By Share-based Payment Award, Grants In Period, Weighted Average Grant Date Fair Value	$ 25,260	$ 19,210

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Examination [Line Items]
Federal									$ 17,005	$ 22,916	$ 9,399
State and local									1,734	2,798	195
Current Federal, State and Local, Tax Expense (Benefit)									18,739	25,714	9,594
Deferred:									7,263	(5,763)	4,277
Deferred Federal Income Tax Expense (Benefit)									5,959	(5,266)	3,908
Deferred State and Local Income Tax Expense (Benefit)									1,304	(497)	369
Deferred Federal, State and Local, Tax Expense (Benefit)									7,263	(5,763)	4,277
Total income tax expense	$ 7,053	$ 6,316	$ 6,747	$ 5,886	$ 5,445	$ 4,722	$ 4,762	$ 5,022	$ 26,002	$ 19,951	$ 13,871

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Increase (reduction) in income tax resulting from:
Income tax expense at statutory rate									$ 26,194	$ 20,440	$ 14,365
Tax-exempt income, net									(945)	(931)	(857)
State and local income taxes, net									1,673	1,414	741
Bank-owned life insurance, net									(544)	(462)	(535)
Non-deductible expenses									263	259	290
Change in estimated rate for deferred taxes									302	0	0
Tax benefits of LIHTC investments, net									(181)	(179)	(158)
Other, net									(760)	(590)	25
Total income tax expense	$ 7,053	$ 6,316	$ 6,747	$ 5,886	$ 5,445	$ 4,722	$ 4,762	$ 5,022	$ 26,002	$ 19,951	$ 13,871

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Allowance for loan losses	$ 16,496	$ 16,705
Basis difference on PCI assets, net	5,551	8,806
Basis difference on Other real estate	317	328
Deferred compensation	4,217	4,509
Goodwill and other intangible assets	5,520	6,973
Accrued compensation	899	2,222
Unrealized losses on securities available for sale	1,019	0
Other, net	925	907
Total deferred tax assets	34,944	40,450
Deferred tax liabilities:
Unrealized gains on securities available for sale	0	183
State tax credits held for sale, net of economic hedge	376	594
Core deposit intangibles	817	1,178
Total deferred tax liabilities	1,193	1,955
Deferred Tax Assets, Net	33,751	38,495
Other Assets
Deferred tax liabilities:
Deferred Tax Assets, Net	$ 33,800	$ 38,500

Income Taxes - Schedule of Unre

Income Taxes - Schedule of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Balance at beginning of year	$ 1,359	$ 1,884	$ 1,257
Additions based on tax positions related to the current year	239	230	401
Additions for tax positions of prior years	39	46	523
Reductions for tax positions of prior years	0	(437)	0
Settlements or lapse of statute of limitations	(457)	(364)	(297)
Balance at end of year	$ 1,180	$ 1,359	$ 1,884

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details)	12 Months Ended
	Dec. 31, 2016USD ($)state	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Income Tax Disclosure [Abstract]
Statutory federal income tax rate	35.00%	35.00%	35.00%
Income Tax Examination [Line Items]
Tax credits and other tax benefits from low-income housing tax credit	$ 1,100,000	$ 1,100,000	$ 1,100,000
Amount recognized as a component of income tax expense related low-income housing tax credit	300,000	300,000	200,000
Investments related to low-income housing tax credits	1,400,000	2,300,000
Impairment losses recognized from forfeiture or ineligibility	0	0	0
Future capital commitments related to low-income housing tax credit investments	100,000
Deferred Tax Assets, Net	$ 33,751,000	38,495,000
Number of states the company files income tax returns in | state	9
Unrecognized tax benefits	$ 1,180,000	1,359,000	1,884,000	$ 1,257,000
Unrecognized tax benefits that would impact effective tax rate	800,000	900,000	$ 1,300,000
Reduction in unrecognized tax benefit that is reasonably possible due to a lapse of statute of limitations	$ 300,000
Duration of unrecognized tax benefits	12 months
State and Local Jurisdiction [Member]
Income Tax Examination [Line Items]
State valuation allowance		0
Other Assets
Income Tax Examination [Line Items]
Deferred Tax Assets, Net	$ 33,800,000	$ 38,500,000

Commitments (Details)

Commitments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Commitments to extend credit
Schedule of Commitments [Line Items]
Off-balance sheet financial instruments, contractual amounts	$ 1,075,170	$ 1,140,028
Letters of credit
Schedule of Commitments [Line Items]
Off-balance sheet financial instruments, contractual amounts	$ 78,954	54,648
Letters of credit | Minimum
Schedule of Commitments [Line Items]
Remaining term	1 month
Letters of credit | Maximum
Schedule of Commitments [Line Items]
Remaining term	4 years 9 months
Unadvanced Commitment on Impaired Loan
Schedule of Commitments [Line Items]
Estimated losses attributable to unadvanced commitments on impaired loans	$ 300
Fixed Rate Loan Commitment | Commitments to extend credit
Schedule of Commitments [Line Items]
Off-balance sheet financial instruments, contractual amounts	$ 89,700	$ 93,900

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Assets
Securities available for sale	$ 460,797	$ 451,770
State tax credits held for sale	3,585	5,941
Portion at Other than Fair Value, Fair Value Disclosure
Assets
State tax credits held for sale	34,500
Total Fair Value
Assets
Securities available for sale	460,797	451,770
State tax credits held for sale	41,264	49,588
Derivative financial instruments	4,016	1,155
Liabilities
Derivative financial instruments	4,016	1,155
Obligations of U.S. Government-sponsored enterprises
Assets
Securities available for sale	107,660	99,008
Obligations of states and political subdivisions
Assets
Securities available for sale	36,631	41,701
Residential mortgage-backed securities
Assets
Securities available for sale	316,506	311,061
Recurring basis | Total Fair Value
Assets
Securities available for sale	460,797	451,770
State tax credits held for sale	3,585	5,941
Derivative financial instruments	4,016	1,155
Assets, Fair Value Disclosure	468,398	458,866
Liabilities
Derivative financial instruments	4,016	1,155
Total liabilities	4,016	1,155
Recurring basis | Obligations of U.S. Government-sponsored enterprises | Total Fair Value
Assets
Securities available for sale	107,660	99,008
Recurring basis | Obligations of states and political subdivisions | Total Fair Value
Assets
Securities available for sale	36,631	41,701
Recurring basis | Residential mortgage-backed securities | Total Fair Value
Assets
Securities available for sale	316,506	311,061
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	0	0
State tax credits held for sale	0	0
Derivative financial instruments	0	0
Assets, Fair Value Disclosure	0	0
Liabilities
Derivative financial instruments	0	0
Total liabilities	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Obligations of U.S. Government-sponsored enterprises
Assets
Securities available for sale	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Obligations of states and political subdivisions
Assets
Securities available for sale	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Residential mortgage-backed securities
Assets
Securities available for sale	0	0
Recurring basis | Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	457,708	448,693
State tax credits held for sale	0	0
Derivative financial instruments	4,016	1,155
Assets, Fair Value Disclosure	461,724	449,848
Liabilities
Derivative financial instruments	4,016	1,155
Total liabilities	4,016	1,155
Recurring basis | Significant Other Observable Inputs (Level 2) | Obligations of U.S. Government-sponsored enterprises
Assets
Securities available for sale	107,660	99,008
Recurring basis | Significant Other Observable Inputs (Level 2) | Obligations of states and political subdivisions
Assets
Securities available for sale	33,542	38,624
Recurring basis | Significant Other Observable Inputs (Level 2) | Residential mortgage-backed securities
Assets
Securities available for sale	316,506	311,061
Recurring basis | Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	3,089	3,077
State tax credits held for sale	3,585	5,941
Derivative financial instruments	0	0
Assets, Fair Value Disclosure	6,674	9,018
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	3,089	3,077
Recurring basis | Significant Unobservable Inputs (Level 3) | Residential mortgage-backed securities
Assets
Securities available for sale	$ 0	$ 0

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)security	Dec. 31, 2015USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
State tax credits, held for sale, including $3,585 and $5,941 carried at fair value, respectively	$ 38,071	$ 45,850
State Tax Credits Held For Sale, Fair Value Disclosure	$ 3,585	5,941
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, including $3,585 and $5,941 carried at fair value, respectively	$ 38,100
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	$ 3,585	5,941
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	$ 34,500
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	41,264	49,588
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	3,585	5,941
State tax credits held for sale, at fair value | Recurring basis | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Change in unrealized (losses) gains relating to assets still held at the reporting date	$ (575)	$ 1,212
Minimum | State tax credits held for sale, at fair value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	2.30%
Maximum | State tax credits held for sale, at fair value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	4.82%
LIBOR | LIBOR Swap Curve
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate basis point spread	2.05
Discount rate basis spread on variable rate	205.00%	205.00%
Lower range of basis spread on variable rate	265.00%
Higher range of basis spread on variable rate	285.00%
Prime Rate | State tax credits held for sale, at fair value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate basis spread on variable rate	75.00%

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	$ 460,797	$ 451,770
Held-to-maturity Securities, Fair Value	79,639	43,441
Level 3 | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	3,089	3,077
Level 3 | Securities available for sale, at fair value | Recurring basis
Level 3 Financial Instruments Measured at Fair Value
Beginning balance	3,077	3,059
Total gains:
Included in other comprehensive income	12	18
Purchases, sales, issuances and settlements
Purchases, sales, issuances and settlements	0	0
Ending balance	3,089	3,077
Change in unrealized gains relating to assets still held at the reporting date	12	18
Level 3 | State tax credits held for sale, at fair value | Recurring basis
Level 3 Financial Instruments Measured at Fair Value
Beginning balance	5,941	11,689
Total gains:
Total gains:	177	406
Purchases, sales, issuances and settlements
Sales	(2,533)	(6,154)
Ending balance	3,585	5,941
Change in unrealized gains relating to assets still held at the reporting date	575	(1,212)
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0	0
Significant Other Observable Inputs (Level 2) | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	457,708	448,693
Total Fair Value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	460,797	451,770
Total Fair Value | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	460,797	451,770
Obligations of U.S. Government-sponsored enterprises
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	107,660	99,008
Obligations of U.S. Government-sponsored enterprises | Level 3 | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0	0
Obligations of U.S. Government-sponsored enterprises | Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0	0
Obligations of U.S. Government-sponsored enterprises | Significant Other Observable Inputs (Level 2) | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	107,660	99,008
Obligations of U.S. Government-sponsored enterprises | Total Fair Value | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	107,660	99,008
Obligations of states and political subdivisions
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	36,631	41,701
Obligations of states and political subdivisions | Level 3 | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	3,089	3,077
Obligations of states and political subdivisions | Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0	0
Obligations of states and political subdivisions | Significant Other Observable Inputs (Level 2) | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	33,542	38,624
Obligations of states and political subdivisions | Total Fair Value | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	36,631	41,701
Residential mortgage-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	316,506	311,061
Residential mortgage-backed securities | Level 3 | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0	0
Residential mortgage-backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0	0
Residential mortgage-backed securities | Significant Other Observable Inputs (Level 2) | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	316,506	311,061
Residential mortgage-backed securities | Total Fair Value | Recurring basis
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	$ 316,506	$ 311,061

Fair Value Measurements - Su101

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 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total (losses) gains for the year	$ 4,336	$ 6,174
Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total (losses) gains for the year	4,335	6,091
Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total (losses) gains for the year	1	83
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Significant Other Observable Inputs (Level 2) | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Significant Other Observable Inputs (Level 2) | Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	175	3,314
Significant Unobservable Inputs (Level 3) | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	175	2,561
Significant Unobservable Inputs (Level 3) | Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	0	753
Total Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	175	3,314
Total Fair Value | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	175	2,561
Total Fair Value | Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	$ 0	$ 753

Fair Value Measurements - Su102

Fair Value Measurements - Summary of Carrying Amount and Fair Values of Financial Instruments Reported on the Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Balance sheet assets
Securities available for sale	$ 460,797	$ 451,770
Securities held to maturity	80,463	43,714
State tax credits held for sale	3,585	5,941
Carrying Amount
Balance sheet assets
Cash and due from banks	54,288	47,935
Federal funds sold	446	91
Interest-bearing deposits	145,048	47,131
Securities available for sale	460,797	451,770
Securities held to maturity	80,463	43,714
Other investments, at cost	14,840	17,455
Loans held for sale	9,562	6,598
Derivative financial instruments	4,016	1,155
Portfolio loans, net	3,114,752	2,781,879
State tax credits held for sale	38,071	45,850
Accrued interest receivable	11,117	8,399
Balance sheet liabilities
Deposits	3,233,361	2,784,591
Subordinated debentures	105,540	56,807
Federal Home Loan Bank advances	0	110,000
Other borrowings	276,980	270,326
Derivative financial instruments	4,016	1,155
Accrued interest payable	1,105	629
Estimated fair value
Balance sheet assets
Cash and due from banks	54,288	47,935
Federal funds sold	446	91
Interest-bearing deposits	145,048	47,131
Securities available for sale	460,797	451,770
Securities held to maturity	79,639	43,441
Other investments, at cost	14,840	17,455
Loans held for sale	9,562	6,598
Derivative financial instruments	4,016	1,155
Portfolio loans, net	3,125,701	2,782,704
State tax credits held for sale	41,264	49,588
Accrued interest receivable	11,117	8,399
Balance sheet liabilities
Deposits	3,232,414	2,784,654
Subordinated debentures	86,052	35,432
Federal Home Loan Bank advances	0	109,994
Other borrowings	276,905	270,286
Derivative financial instruments	4,016	1,155
Accrued interest payable	$ 1,105	$ 629

Fair Value Measurements - Sc103

Fair Value Measurements - Schedule of Estimated Fair Values of Financial Instruments Not Recorded at Fair Value on Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
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	$ 79,639	$ 43,441
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	3,125,701	2,782,704
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	37,679	43,647
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	3,232,414	2,784,654
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	86,052	35,432
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		109,994
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	276,905	270,286
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	2,760,202	2,428,403
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	79,639	43,441
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	86,052	35,432
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		109,994
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	276,905	270,286
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	3,125,701	2,782,704
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	37,679	43,647
Level 3 | Deposits
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial liabilities not on condensed consolidated balance sheets at fair value	472,212	356,251
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

Parent Company Only Condense104

Parent Company Only Condensed Financial Statements - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Cash	$ 198,802	$ 94,157	$ 100,696	$ 210,569
Total assets	4,081,328	3,608,483
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	105,540	56,807
Shareholders' equity	387,098	350,829	316,241	279,705
Total liabilities and shareholders' equity	4,081,328	3,608,483
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Cash	52,245	12,032	$ 14,532	$ 15,969
Other assets	22,111	20,357
Total assets	493,985	407,991
Subordinated debentures (net of debt issuance cost of $1,267 and $0, respectively)	105,540	56,807
Accounts payable and other liabilities	1,347	355
Shareholders' equity	387,098	350,829
Total liabilities and shareholders' equity	493,985	407,991
Enterprise Bank and Trust [Member] | Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Investments	416,831	374,092
Nonbank Subsidiaries [Member] | Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Investments	$ 2,798	$ 1,510

Parent Company Only Condense105

Parent Company Only Condensed Financial Statements - Condensed Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Income [Abstract]
Dividends from subsidiaries									$ 226	$ 141	$ 273
Operating Expenses [Abstract]
Interest expense-subordinated debentures and notes									1,894	1,248	1,322
Interest expense-notes payable	$ 3,984	$ 3,463	$ 3,250	$ 3,032	$ 3,017	$ 3,174	$ 3,072	$ 3,106	13,729	12,369	14,386
Income tax benefit	(7,053)	(6,316)	(6,747)	(5,886)	(5,445)	(4,722)	(4,762)	(5,022)	(26,002)	(19,951)	(13,871)
Net income	$ 13,628	$ 11,832	$ 12,352	$ 11,025	$ 10,679	$ 9,709	$ 8,716	$ 9,346	48,837	38,450	27,173
Total comprehensive income									46,878	36,987	33,234
Parent [Member]
Operating Income [Abstract]
Dividends from subsidiaries									7,500	10,000	10,000
Other									491	249	225
Total income									7,991	10,249	10,225
Operating Expenses [Abstract]
Interest expense-subordinated debentures and notes									1,893	1,248	1,322
Interest expense-notes payable									53	144	193
Other expenses									5,526	3,823	4,402
Total expenses									7,472	5,215	5,917
Income before taxes and equity in undistributed earnings of subsidiaries									519	5,034	4,308
Income tax benefit									2,583	2,118	2,305
Net income									3,102	7,152	6,613
Equity in undistributed earnings of subsidiaries									45,735	31,298	20,560
Total comprehensive income									$ 48,837	$ 38,450	$ 27,173

Parent Company Only Condense106

Parent Company Only Condensed Financial Statements - Consolidated Statements of Cash Flow (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Adjustments to reconcile net income to net cash provided by operating activities
Share-based compensation	$ 3,367	$ 3,601	$ 2,950
Excess tax benefit of share-based compensation	(1,327)	(449)	(205)
Net cash provided by operating activities	82,521	47,187	31,494
Cash flows from investing activities:
Net cash used in investing activities	(358,057)	(337,250)	(212,826)
Cash flows from financing activities:
Repayments of notes payable	0	(5,700)	(4,800)
Cash dividends paid	(8,211)	(5,259)	(4,177)
Excess tax benefit of share-based compensation	1,327	449	205
Issuance of common stock	2	2	2
Common stock repurchased	(4,889)	0	0
Proceeds from the issuance of equity instruments, net	(2,205)	(1,192)	(681)
Net cash provided by financing activities	380,181	283,524	71,459
Net increase (decrease) in cash and cash equivalents	104,645	(6,539)	(109,873)
Cash and cash equivalents, beginning of period	94,157	100,696	210,569
Cash and cash equivalents, end of period	198,802	94,157	100,696
Parent [Member]
Cash flows from operating activities:
Net income available to common shareholders	48,837	38,450	27,173
Adjustments to reconcile net income to net cash provided by operating activities
Share-based compensation	3,367	3,601	2,950
Net income of subsidiaries	(53,235)	(41,298)	(30,560)
Dividends from subsidiaries	7,500	10,000	10,000
Excess tax benefit of share-based compensation	(1,327)	(449)	(205)
Other, net	1,848	848	704
Net cash provided by operating activities	6,990	11,152	10,062
Cash flows from investing activities:
Cash contributions to subsidiaries	(250)	0	0
Purchases of other investments	(2,435)	(2,832)	(2,224)
Proceeds from distributions on other investments	1,151	880	176
Net cash used in investing activities	(1,534)	(1,952)	(2,048)
Cash flows from financing activities:
Proceeds from notes payable	48,733	0	0
Repayments of notes payable	0	(5,700)	(4,800)
Cash dividends paid	(8,211)	(5,259)	(4,177)
Excess tax benefit of share-based compensation	1,327	449	205
Payments for the repurchase of preferred stock	(4,889)	0	0
Issuance of common stock	2	2	2
Proceeds from the issuance of equity instruments, net	(2,205)	(1,192)	(681)
Net cash provided by financing activities	34,757	(11,700)	(9,451)
Net increase (decrease) in cash and cash equivalents	40,213	(2,500)	(1,437)
Cash and cash equivalents, beginning of period	12,032	14,532	15,969
Cash and cash equivalents, end of period	$ 52,245	$ 12,032	$ 14,532

Quarterly Condensed Financia107

Quarterly Condensed Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Interest income	$ 39,438	$ 37,293	$ 37,033	$ 35,460	$ 35,096	$ 33,180	$ 32,352	$ 32,151	$ 149,224	$ 132,779	$ 131,754
Interest expense	3,984	3,463	3,250	3,032	3,017	3,174	3,072	3,106	13,729	12,369	14,386
Net interest income	35,454	33,830	33,783	32,428	32,079	30,006	29,280	29,045	135,495	120,410	117,368
Provision for portfolio loan losses	964	3,038	716	833	543	599	2,150	1,580	5,551	4,872	4,409
Provision reversal for PCI loan losses	(343)	(1,194)	(336)	(73)	(917)	(227)	0	(3,270)	(1,946)	(4,414)	1,083
Net interest income after provision for loan losses	34,833	31,986	33,403	31,668	32,453	29,634	27,130	30,735	131,890	119,952	111,876
Noninterest income	9,029	6,976	7,049	6,005	6,557	4,729	5,806	3,583	29,059	20,675	16,631
Noninterest expense	23,181	20,814	21,353	20,762	22,886	19,932	19,458	19,950	86,110	82,226	87,463
Income before income tax expense	20,681	18,148	19,099	16,911	16,124	14,431	13,478	14,368	74,839	58,401	41,044
Income tax expense	7,053	6,316	6,747	5,886	5,445	4,722	4,762	5,022	26,002	19,951	13,871
Net income	$ 13,628	$ 11,832	$ 12,352	$ 11,025	$ 10,679	$ 9,709	$ 8,716	$ 9,346	$ 48,837	$ 38,450	$ 27,173
Earnings per common share:
Basic (usd per share)	$ 0.68	$ 0.59	$ 0.62	$ 0.55	$ 0.53	$ 0.49	$ 0.44	$ 0.47	$ 2.44	$ 1.92	$ 1.38
Diluted (usd per share)	$ 0.67	$ 0.59	$ 0.61	$ 0.54	$ 0.52	$ 0.48	$ 0.43	$ 0.46	$ 2.41	$ 1.89	$ 1.35

New Authoritative Accounting108

New Authoritative Accounting Guidance - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
New Accounting Pronouncement, Early Adoption [Line Items]
Reclassification of additional paid in capital to retained earnings	$ 5