Cadence Bancorporation 10-K 19 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Mar. 19, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	CADE
Entity Registrant Name	CADENCE BANCORPORATION
Entity Central Index Key	1,614,184
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		83,625,000
Entity Public Float			$ 188.7

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and due from banks	$ 238,707	$ 48,017
Interest-bearing deposits with banks	482,568	199,747
Federal funds sold	9,536	1,161
Total cash and cash equivalents	730,811	248,925
Securities available-for-sale	1,262,948	1,139,347
Securities held-to-maturity	290	425
Other securities - FRB and FHLB stock	50,009	41,493
Loans held for sale	61,359	17,822
Loans	8,253,427	7,432,711
Less: allowance for credit losses	(87,576)	(82,268)
Net loans	8,165,851	7,350,443
Interest receivable	47,793	39,889
Premises and equipment, net	63,432	66,676
Other real estate owned	7,605	18,875
Cash surrender value of life insurance	108,148	105,834
Net deferred tax asset	30,774	83,662
Goodwill	317,817	317,817
Other intangible assets, net	10,223	14,874
Other assets	91,866	84,806
Total Assets	10,948,926	9,530,888
Liabilities:
Noninterest-bearing deposits	2,242,765	1,840,955
Interest-bearing deposits	6,768,750	6,175,794
Total deposits	9,011,515	8,016,749
Securities sold under agreements to repurchase	1,026	3,494
Federal Home Loan Bank advances	150,000	0
Senior debt	184,629	193,788
Subordinated debt	98,687	98,441
Junior subordinated debentures	36,472	35,989
Other liabilities	107,541	101,929
Total liabilities	9,589,870	8,450,390
Shareholders' Equity:
Common Stock	836	750
Additional paid-in capital	1,037,040	879,665
Retained earnings	340,213	232,614
Accumulated other comprehensive loss ("OCI")	(19,033)	(32,531)
Total shareholders' equity	1,359,056	1,080,498
Total Liabilities and Shareholders' Equity	$ 10,948,926	$ 9,530,888

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Estimated fair value of held-to-maturity securities	$ 311	$ 463
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	83,625,000	75,000,000
Common Stock, Shares, Outstanding	83,625,000	75,000,000

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
INTEREST INCOME
Interest and fees on loans	$ 359,308	$ 305,553	$ 272,434
Interest and dividends on securities:
Taxable	18,089	15,838	14,329
Tax-exempt	13,360	8,752	2,433
Other interest income	6,110	5,107	3,871
Total interest income	396,867	335,250	293,067
INTEREST EXPENSE
Interest on time deposits	22,213	17,191	12,768
Interest on other deposits	27,486	18,255	13,053
Interest on borrowed funds	20,952	20,365	19,468
Total interest expense	70,651	55,811	45,289
Net interest income	326,216	279,439	247,778
Provision for credit losses	9,735	49,348	35,984
Net interest income after provision for credit losses	316,481	230,091	211,794
NONINTEREST INCOME
Service charges on deposit accounts	15,272	13,793	12,464
Other service fees	4,414	2,884	2,293
Credit related fees	12,166	10,729	12,495
Trust services revenue	19,264	16,109	15,800
Mortgage banking income	3,731	4,663	4,384
Investment advisory revenue	20,517	18,811	17,681
Securities (losses) gains, net	(146)	3,736	1,171
Accretion of FDIC indemnification asset			(1,402)
Other income	24,656	17,678	15,017
Total noninterest income	99,874	88,403	79,903
NONINTEREST EXPENSE
Salaries and employee benefits	139,118	125,068	128,267
Premises and equipment	28,921	27,982	29,781
Intangible asset amortization	4,652	6,532	8,428
Other expense	60,665	60,598	65,856
Total noninterest expense	233,356	220,180	232,332
Income before income taxes	182,999	98,314	59,365
Income tax expense	80,646	32,540	20,109
Net income	$ 102,353	$ 65,774	$ 39,256
Weighted average common shares outstanding (Basic)	81,072,945	75,000,000	75,000,000
Weighted average common shares outstanding (Diluted)	81,605,015	75,294,600	75,116,100
Earnings per common share (Basic)	$ 1.26	$ 0.88	$ 0.52
Earnings per common share (Diluted)	$ 1.25	$ 0.87	$ 0.52

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 102,353	$ 65,774	$ 39,256
Net unrealized gains (losses) on securities available-for-sale:
Unrealized gains (losses) arising during the period	21,513	(25,361)	(2,024)
Reclassification adjustments for losses (gains) realized in net income	92	(2,359)	(739)
Net unrealized gains (losses) on securities available-for-sale	21,605	(27,720)	(2,763)
Net unrealized (losses) gains on derivative instruments designated as cash flow hedges:
Unrealized (losses) gains arising during the period	(643)	(4,732)	4,705
Reclassification adjustments for gains realized in net income	(2,339)	(7,106)	(3,079)
Net change in unrealized (losses) gains on derivative instruments	(2,982)	(11,838)	1,626
Change in pension liability:
Actuarial gains (losses) arising during the period	37	(145)	15
Reclassification adjustments for losses realized in net income	84	132	97
Net unrealized gains (losses) on pension liability	121	(13)	112
Other comprehensive income (loss), net of tax	18,744	(39,571)	(1,025)
Comprehensive income	$ 121,097	$ 26,203	$ 38,231

CONSOLIDATED STATEMENTS OF COM6

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Unrealized gains (losses)arising during the period, tax effect	$ (10,558)	$ 14,691	$ 1,249
Reclassification adjustments for losses (gains) realized in net income, tax effect	(54)	1,377	432
Unrealized (losses) gains arising during the period, tax effect	783	2,712	(2,748)
Reclassification adjustments for gains realized in net income, tax effect	1,366	4,149	1,798
Actuarial gains (losses) arising during the period, tax effect	(11)	81	(11)
Reclassification adjustments for losses realized in net income, tax effect	$ (26)	$ (77)	$ (58)

STATEMENTS OF CHANGES IN SHAREH

STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated OCI
Balance at Dec. 31, 2014	$ 1,014,337	$ 750	$ 877,938	$ 127,584	$ 8,065
Equity-based compensation cost	1,640		1,640
Net income	39,256			39,256
Other comprehensive income (loss)	(1,025)				(1,025)
Balance at Dec. 31, 2015	1,054,208	750	879,578	166,840	7,040
Equity-based compensation cost	87		87
Net income	65,774			65,774
Other comprehensive income (loss)	(39,571)				(39,571)
Balance at Dec. 31, 2016	1,080,498	750	879,665	232,614	(32,531)
Equity-based compensation cost	1,880		1,880
Net income	102,353			102,353
Other comprehensive income (loss)	18,744				18,744
Reclassification of amounts within AOCI to retained earnings due to tax reform				5,246	(5,246)
Issuance of 8,625,000 common shares,net of issuance costs	155,581	86	155,495
Balance at Dec. 31, 2017	$ 1,359,056	$ 836	$ 1,037,040	$ 340,213	$ (19,033)

STATEMENTS OF CHANGES IN SHARE8

STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Parenthetical)	12 Months Ended
	Dec. 31, 2017shares
Statement Of Stockholders Equity [Abstract]
Issuance of common shares	8,625,000

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 102,353	$ 65,774	$ 39,256
Adjustments to reconcile net income to net cash provided by operations:
Depreciation and amortization	13,635	13,250	18,262
Deferred income taxes	44,388	5,980	(2,928)
Provision for credit losses	9,735	49,348	35,984
Loss (gain) on sale of securities, net	146	(3,736)	(1,171)
Gain on sale of loans, net	(2,670)	(2,904)	(2,444)
Loss on foreclosed property, net	1,073	2,114	2,489
(Increase) decrease in interest receivable	(7,904)	(4,155)	6,712
Proceeds from sale of loans held for sale	195,130	137,351	148,147
Origination of loans held for sale	(237,404)	(136,774)	(142,762)
Decrease (increase) in other assets	4,079	(11,685)	1,785
Increase in interest payable	1,361	725	1,086
Increase in other liabilities	16,717	286	3,736
Other, net	4,059	2,439	2,055
Net cash provided by operating activities	144,698	118,013	110,207
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of securities available-for-sale	(369,786)	(1,120,250)	(478,323)
Proceeds from sales of securities available-for-sale	161,401	538,960	188,755
Proceeds from maturities, calls and paydowns of securities available-for-sale	96,728	134,501	114,064
Proceeds from sale of commercial loans held for sale	17,613	328,381
Net cash paid in branch sales			(208,439)
Increase in loans, net	(847,428)	(913,069)	(805,141)
Purchase of premises and equipment	(6,428)	(5,356)	(11,125)
Proceeds from disposition of foreclosed property	17,220	28,489	30,904
Other, net	(20,423)	14,986	(18,920)
Net cash used in investing activities	(951,103)	(993,358)	(1,188,225)
CASH FLOWS FROM FINANCING ACTIVITIES
Increase in deposits, net	994,778	1,029,487	661,947
Net change in securities sold under agreements to repurchase	(2,468)	(2,346)	(6,204)
Net change in short-term FHLB advances	150,000	(370,000)	370,000
Purchase of senior debt	(9,600)	(78)
Issuance of subordinated debt, net of debt issuance costs			39,253
Issuance of senior debt, net of debt issuance costs			9,813
Proceeds from issuance of common stock	155,581
Net cash provided by financing activities	1,288,291	657,063	1,074,809
Net increase (decrease) in cash and cash equivalents	481,886	(218,282)	(3,209)
Cash and cash equivalents at beginning of period	248,925	467,207	470,416
Cash and cash equivalents at end of period	$ 730,811	$ 248,925	$ 467,207

Summary of Accounting Policies

Summary of Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Accounting Policies	Note 1—Summary of Accounting Policies Basis of Presentation and Consolidation The Company and its subsidiaries follow accounting principles generally accepted in the United States of America, including, where applicable, general practices within the banking industry. The consolidated financial statements include the accounts of the Company and its subsidiaries. Significant intercompany accounts and transactions have been eliminated in consolidation. The assessment of whether or not the Company has a controlling interest (i.e., the primary beneficiary) in a variable-interest entity (“VIE”) is performed on an on-going basis. All equity investments in non-consolidated VIEs are included in “other assets” in the Company’s consolidated balance sheets (Note 19). Certain amounts reported in prior years have been reclassified to conform to the 2017 presentation. These reclassifications did not materially impact the Company’s consolidated balance sheets or consolidated statements of income. In accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 855, “Subsequent Events,” the Company’s Management has evaluated subsequent events for potential recognition or disclosure in the consolidated financial statements through the date of the issuance of these consolidated financial statements. No subsequent events were identified that would have required a change to the consolidated financial statements or disclosure in the notes to the consolidated financial statements, other than as disclosed in Note 25, Subsequent Events. Stock Split On March 30, 2017, the Board of Directors approved a 75-for-one stock split of the Company’s common stock. The stock split occurred on April 7, 2017. The effect of the stock split on outstanding shares and earnings per share has been retroactively applied to all periods presented. Nature of Operations The Company’s subsidiaries include: • Town & Country Insurance Agency, Inc., dba Cadence Insurance—full service insurance agency; and • The Bank. The Bank operates under a national bank charter and is subject to regulation by the Office of the Comptroller of the Currency (OCC). The Bank provides lending services in Georgia and full banking services in five southern states: Alabama, Florida, Mississippi, Tennessee, and Texas. The Bank’s subsidiaries include: • Linscomb & Williams Inc. —financial advisory firm; and • Cadence Investment Services, Inc.—provides investment and insurance products. The Company and the Bank also have certain other non-operating and immaterial subsidiaries. Branch Sales In March and October, 2015, the Company sold the assets and transferred the liabilities of eight branches in Florida (6) and Georgia (2) and recognized a loss of $1.5 million. The following table summarizes the allocation of the sale price to assets sold and liabilities transferred: (In thousands) 2015 Cash on hand $ 1,254 Loans 42,477 Premises and equipment 3,095 Other assets 113 Total assets sold 46,939 Deposits 253,823 Other liabilities 301 Total liabilities transferred 254,124 Cash paid $ 207,185 Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are susceptible to significant change in the near term are the allowance for credit losses, valuation of and accounting for acquired credit impaired loans, valuation of goodwill, intangible assets and deferred income taxes. Securities Securities are accounted for as follows: Securities Available-for-Sale Securities classified as available-for-sale are those securities that are intended to be held for an indefinite period of time, but not necessarily to maturity. Any decision to sell a security classified as available-for-sale would be based on various factors, including movements in interest rates, liquidity needs, security risk assessments, changes in the mix of assets and liabilities and other similar factors. These securities are carried at their estimated fair value, and the net unrealized gain or loss is reported as accumulated other comprehensive income, net of tax, until realized. Premiums and discounts are recognized in interest income using the effective interest method. Realized gains and losses on the sale of securities available-for-sale are determined by specific identification using the adjusted cost on a trade date basis and are included in securities gains (losses), net. Securities Held-to-Maturity Securities classified as held-to-maturity are those securities for which there is a positive intent and ability to hold to maturity. These securities are carried at cost, adjusted for amortization of premium and accretion of discount, computed by the interest method. Trading Account Securities Trading account securities are securities that are held for the purpose of selling them at a profit. The Company had no trading account securities as of December 31, 2017 or 2016. FHLB and FRB Stock The Company has ownership in Federal Home Loan Bank “FHLB” and Federal Reserve Bank “FRB” stock which do not have a readily determinable fair value and no quoted market values, as ownership is restricted to member institutions, and all transactions take place at par value with the FHLB or FRB as the only purchaser. Therefore, the Company accounts for these investments as long-term assets and carries them at cost. Management’s determination as to whether these investments are impaired is based on management’s assessment of the ultimate recoverability of the par value (cost) rather than recognizing temporary declines in fair value. In order to become a member of the Federal Reserve System, regulations require that the Company hold a certain amount of FRB capital stock. Additionally, investment in FHLB stock is required for membership in the FHLB system and in relation to the level of FHLB outstanding borrowings. Derivative Financial Instruments and Hedging Activities Derivative instruments are accounted for under the requirements of ASC Topic 815, “Derivatives and Hedging.” ASC Topic 815 requires companies to recognize all of their derivative instruments as either assets or liabilities in the consolidated balance sheets at fair value. The fair value of derivative positions outstanding is included in other assets and other liabilities in the accompanying consolidated balance sheets and in the net change in each of these financial statement line items in the accompanying consolidated statements of cash flows. The Company does not speculate using derivative instruments. Interest Rate Lock Commitments In the ordinary course of business, the Company enters into certain commitments with customers in connection with residential mortgage loan applications. Such commitments are considered derivatives under current accounting guidance and are required to be recorded at fair value. The change in fair value of these instruments is reflected currently in the mortgage banking revenue of the consolidated statements of income. Forward Sales Commitments The Company enters into forward sales commitments of mortgage-backed securities (“MBS”) with investors to mitigate the effect of the interest rate risk inherent in providing interest rate lock commitments to customers. During the period from commitment date to closing date, the Company is subject to the risk that market rates of interest may change. In an effort to mitigate such risk, forward delivery sales commitments, under which the Company agrees to deliver certain MBS, are established. These commitments are non-hedging derivatives in accordance with current accounting guidance and recorded at fair value, with changes in fair value reflected currently in the mortgage banking revenue of the consolidated statements of income. Interest Rate Swap, Floor and Cap Agreements Not Designated as Hedging Derivatives The Company enters into interest rate swap, floor and cap agreements on commercial loans with customers to meet the financing needs and interest rate risk management needs of its customers. At the same time, the Company enters into an offsetting interest rate swap, floor or cap agreement with a financial institution in order to minimize the Company’s interest rate risk. These interest rate swap and cap agreements are non-hedging derivatives and are recorded at fair value with changes in fair value reflected in noninterest income. The fair value of these derivatives is recorded on the consolidated balance sheets in other assets and other liabilities. Interest Rate Swap Agreements Designated as Cash Flow Hedges Cash flow hedge relationships mitigate exposure to the variability of future cash flows or other forecasted transactions. The Company uses interest rate swaps to manage overall cash flow changes related to interest rate risk exposure on benchmark interest rate loans. The effective portion of the gain or loss related to the derivative instrument is recognized as a component of other comprehensive income and subsequently reclassified into interest income when the forecasted transaction affects income. The ineffective portion of the gain or loss is recognized immediately as noninterest income. The Company assesses the effectiveness of the hedging derivative by comparing the change in fair value of the respective derivative instrument and the change in fair value of an effective hypothetical derivative instrument. Foreign Currency Contracts The Company enters into certain foreign currency exchange contracts on behalf of its clients to facilitate their risk management strategies, while at the same time entering into offsetting foreign currency exchange contracts in order to minimize the Company’s foreign currency exchange risk. The contracts are short term in nature, and any gain or loss incurred at settlement is recorded as other noninterest income or other noninterest expense. The fair value of these contracts is reported in other assets and other liabilities. The Company does not apply hedge accounting to these contracts. Counterparty Credit Risk Derivative contracts involve the risk of dealing with both bank customers and institutional derivative counterparties and their ability to meet contractual terms. Under Company policy, institutional counterparties must be approved by the Company’s Asset/Liability Management Committee. The Company’s credit exposure on derivatives is limited to the net fair value for each counterparty. Refer to Note 6 for further discussion and details of derivative financial instruments and hedging activities. Transfers of Financial Assets Transfers of financials assets are accounted for as sales when control over the transferred assets is surrendered. Control is generally considered to have been surrendered when 1) the transferred assets are legally isolated from the Company or its consolidated affiliates, even in bankruptcy or other receivership, 2) the transferee has the right to pledge or exchange the assets with no conditions that constrain the transferee and provide more than a trivial benefit to the Company, and 3) the Company does not maintain the obligation or unilateral ability to reclaim or repurchase the assets. If these sale criteria are met, the transferred assets are removed from the Company’s balance sheet and a gain or loss on sale is recognized. If not met, the transfer is recorded as a secured borrowing, and the assets remain on the Company’s balance sheet, the proceeds from the transaction are recognized as a liability, and gain or loss on sale is deferred until the sale criterion are achieved. All transfers of financial assets in the reported periods have qualified and been recorded as sales. Loans Held for Sale Mortgage Loans Held for Sale Mortgage loans originated and intended for sale in the secondary market are carried at the lower of cost or estimated fair value in the aggregate. Generally, loans in this category are sold within thirty days. These loans are primarily sold with the mortgage servicing rights released. Fees on mortgage loans sold individually in the secondary market, including origination fees, service release premiums, processing and administrative fees, and application fees, are recognized as mortgage banking revenue in the period in which the loans are sold. These loans are underwritten to the standards of upstream correspondents and are held on the Company’s consolidated balance sheets until the loans are sold. Buyers generally have recourse to return a purchased loan to the Company under limited circumstances. Recourse conditions may include early payment default, breach of representations or warranties, and documentation deficiencies. During 2017, 2016 and 2015, an insignificant number of loans were returned to the Company. Commercial Loans Held for Sale The Company originates certain commercial loans for which a portion is intended for sale. The Company also transfers certain commercial loans to held for sale when management has the intent to sell the loan or a portion of the loan in the near term. These held for sale loans are recorded at the lower of cost or estimated fair value. At the time of transfer, write-downs on the loans are recorded as charge-offs and a new cost basis is established. Any subsequent lower of cost or market adjustment is determined on an individual loan basis and is recognized as a valuation allowance with any charges included in other noninterest expense. Gains and losses on the sale of these loans are included in other noninterest income when realized. A summary of the loans held for sale at December 31, 2017 and 2016 is as follows: As of December 31, (In thousands) 2017 2016 Mortgage loans held for sale $ 5,834 $ 8,369 Commercial loans held for sale 55,525 9,453 Loans held for sale $ 61,359 $ 17,822 Loans (Excluding Acquired Credit Impaired Loans) Loans include loans that are originated by the Company and acquired loans that are not considered impaired at acquisition. Loans originated by the Company are carried at the principal amount outstanding adjusted for the allowance for credit losses, net of deferred origination fees, and unamortized discounts and premiums. Interest income is recognized based on the principal balance outstanding and the stated rate of the loan. Loan origination fees and certain direct origination costs are capitalized and recognized as an adjustment of the yield on the related loan. Loans acquired through acquisition are initially recorded at fair value. Discounts created when the loans were recorded at their estimated fair values at acquisition are accreted over the remaining term of the loan as an adjustment to the related loan’s yield. Commercial loans, including small business loans, are generally placed on nonaccrual status when principal or interest is past due ninety days or more unless the loan is well secured and in the process of collection, or when the loan is specifically determined to be impaired. Consumer loans, including residential first and second lien loans secured by real estate, are generally placed on nonaccrual status when they are 120 or more days past due. The accrual of interest, as well as the amortization/accretion of any remaining unamortized net deferred fees or costs and discount or premium, is generally discontinued at the time the loan is placed on nonaccrual status. All accrued but uncollected interest for loans that are placed on nonaccrual status is reversed through interest income. Cash receipts received on nonaccrual loans are generally applied against principal until the loan has been collected in full, after which time any additional cash receipts are recognized as interest income (i.e., cost recovery method). However, interest may be accounted for under the cash-basis method as long as the remaining recorded investment in the loan is deemed fully collectible. Non-impaired loans are evaluated for potential charge-off in accordance with the parameters discussed below or when the loan is placed on non-accrual status, whichever is earlier. Loans within the commercial portfolio are generally evaluated for charge-off at 90 days past due, unless both well-secured and in the process of collection. Closed and open-end residential mortgage and consumer loans are evaluated for charge-off no later than 120 days past due. Any outstanding loan balance in excess of the fair value of the collateral less costs to sell is charged-off no later than 180 days past due for loans secured by real estate. For non-real estate secured loans, in lieu of charging off the entire loan balance, loans may be written down to the fair value of the collateral less costs to sell if repossession of collateral is assured and in process. A loan is considered to be impaired when it appears probable that the entire amount contractually due will not be collected. Factors considered in determining impairment include payment status, collateral values, and the probability of collecting scheduled payments of principal and interest when due. The measurement of impaired loans is based on the present value of expected future cash flows discounted at the loan’s effective interest rate or the loan’s observable market price, or based on the fair value of the collateral if the loan is collateral dependent. Included in impaired loans are loans considered troubled debt restructurings (“TDRs”). The Company attempts to work with borrowers when necessary to extend or modify loan terms to better align with the borrower’s ability to repay. Extensions and modifications to loans are made in accordance with internal policies and guidelines which conform to regulatory guidance. A modification is classified as a TDR if the borrower is experiencing financial difficulty and it is determined that the Company has granted a concession to the borrower. The Company may determine that a borrower is experiencing financial difficulty if the borrower is currently in default on any of its debt, or if it is probable that a borrower may default in the foreseeable future without the modification. Concessions could include reductions of interest rates, extension of the maturity date at a rate lower than current market rate for a new loan with similar risk, reduction of accrued interest, principal forgiveness, forbearance, or other concessions. The assessments of whether a borrower is experiencing or will likely experience financial difficulty and whether a concession has been granted is highly subjective in nature, and management’s judgment is required when determining whether a modification is classified as a TDR. Current amendments to the accounting guidance preclude a creditor from using the effective interest rate test in the debtor’s guidance on restructuring of payables (paragraph 470-60-55-10) when evaluating whether a restructuring constitutes a TDR. Allowance for Credit Losses The allowance for credit losses (“ACL”) is established through charges to income in the form of a provision for credit losses. The ACL is maintained at a level that management believes is adequate to absorb all probable losses on loans inherent in the loan portfolio as of the reporting date. Events that are not within the Company’s control, such as changes in economic factors, could change subsequent to the reporting date and could cause the ACL to be overstated or understated. The amount of the ACL is affected by loan charge-offs, which decrease the ACL; recoveries on loans previously charged off, which increase the ACL; and the provision for credit losses charged to income, which increases the ACL. In determining the provision for credit losses, management monitors fluctuations in the ACL resulting from actual charge-offs and recoveries and reviews the size and composition of the loan portfolio in light of current and anticipated economic conditions. The ACL is comprised of the following four components: • Specific reserves are recorded on loans reviewed individually for impairment. Generally, all loans that are individually identified as impaired are reviewed on a quarterly basis in order to determine whether a specific reserve is required. A loan is considered impaired when, based on current information, it is probable that we will not receive all amounts due in accordance with the contractual terms of the loan agreement. Once a loan has been identified as impaired, management measures impairment in accordance with ASC Topic 310, “Receivables.” The measurement of impaired loans is based on the present value of expected future cash flows discounted at the loan’s effective interest rate or the loan’s observable market price, or based on the fair value of the collateral if the loan is collateral dependent. When management’s measured value of the impaired loan is less than the recorded investment in the loan, the amount of the impairment is recorded as a specific reserve. These specific reserves are determined on an individual loan basis based on management’s current evaluation of the loss exposure for each credit, given the payment status, the financial condition of the borrower and any guarantors and the value of any underlying collateral. Loans that are individually identified as impaired are excluded from the general reserve calculation described below. Changes in specific reserves from period to period are the result of changes in the circumstances of individual loans such as charge-offs, payments received, changes in collateral values or other factors. • For loans not considered to be impaired, a general reserve is maintained for each loan segment in the loan portfolio. Due to the growth of the credit portfolio into new geographic areas and into new commercial segmentations and the lack of seasoning of the portfolio, the Company recognizes there is limited historical loss information to adequately estimate loss rate bands based primarily on historical loss data. Therefore, external loss data was acquired from the research arm of a nationally recognized risk rating agency to act as a proxy for loss rates within the ACL model until sufficient loss history can be accumulated from the Company’s loss experience in these segments. These loss rate bands were developed specifically for the Company’s customer risk profile and portfolio mix. The Company monitors actual loss experience for each loan segment for adjustments required to the loss rates utilized. • In assessing the overall risk of the credit portfolio, the ACL Committee also considers the following qualitative factors that may indicate additional credit losses within the current credit portfolio. Management discretion dictates how these factors should affect certain segments (or the entire portfolio) according to a number of basis points to be added to (or subtracted from) loan loss rates. By their nature, qualitative adjustments attempt to quantify and standardize factors that serve as “leading indicators” of credit deterioration or improvement. These primary adjustment factors include, but are not limited to the following: • Lending policies, procedures, practices or philosophy, including underwriting standards and collection, charge-off and recovery practices • Changes in national and service market economic and business conditions that could affect the level of default rates or the level of losses once a default has occurred within the Bank’s existing loan portfolio • Changes in the nature or size of the portfolio • Changes in portfolio collateral values • Changes in the experience, ability, and depth of lending management and other relevant staff • Volume and/or severity of past due and classified credits or trends in the volume of losses, non-accrual credits, impaired credits and other credit modifications • Quality of the institution’s credit review system and processes and the degree of oversight by bank management and the board of directors • Concentrations of credit such as industry and lines of business • Competition and legal and regulatory requirements or other external factors. • In connection with acquisitions (see Accounting for Acquired Loans and FDIC Loss Share Receivable Management presents the quarterly review of the ACL to the Bank’s Board of Directors, indicating any recommendations as to adjustments in the ACL. This evaluation is inherently subjective as it requires estimates that are susceptible to significant revision as more information becomes available or as events change. The reserve for unfunded commitments is determined by assessing three distinct pieces: unfunded commitment volatility in the portfolio (excluding commitments related to letters of credit and commitment letters), adverse letters of credit, and adverse lines of credit. Unfunded commitment volatility is calculated on a trailing eight quarter basis; the resulting expected funding amount is then reserved for based on the current combined reserve rate of the originated and ANCI loans. Adverse lines and letters of credit are assessed individually based on funding and loss expectations as of the period end. The reserve for unfunded commitments is recorded in other liabilities and other noninterest expense separate from the allowance and provision for credit losses. As of December 31, 2017 and 2016 the reserve for unfunded commitments totaled $0.8 million and $1.6 million, respectively. Accounting for Acquired Loans and FDIC Loss Share Receivable Acquired Loans The Company accounts for its acquisitions under ASC Topic 805, which requires the use of the acquisition method of accounting. All identifiable assets acquired, including loans, are recorded at fair value. No ACL related to the acquired loans is recorded on the acquisition date as the fair value of the loans acquired incorporates assumptions regarding credit risk. Loans acquired are recorded at fair value in accordance with the fair value methodology prescribed in ASC Topic 820, exclusive of the shared-loss agreements with the Federal Deposit Insurance Corporation (“FDIC”) (see “FDIC Indemnification Asset” below). The fair value estimates associated with the loans include estimates related to the amount and timing of undiscounted expected principal, interest and other cash flows, as well as the appropriate discount rate. At the time of acquisition, the Company estimated the fair value of the total acquired loan portfolio by segregating the portfolio into loan pools with similar characteristics and certain specifically-reviewed non-homogeneous loans. The similar characteristics used to establish the pools included: • Risk rating, • The loan type based on regulatory reporting guidelines; namely whether the loan was a residential, construction, consumer, or commercial loan, and • The nature of collateral. From these pools, the Company used certain loan information, including outstanding principal balance, estimated probability of default and loss given default, weighted average maturity, weighted average term to re-price (if a variable rate loan), estimated prepayment rates, and weighted average interest rate to estimate the expected cash flow for each loan pool. For the specifically-reviewed loans expected cash flows were determined for each loan based on current performance and collateral values, if the loan is collateral dependent. The Company accounts for and evaluates acquired credit impaired (“ACI”) loans in accordance with the provisions of ASC Topic 310-30. When ACI loans exhibit evidence of credit deterioration since origination and it is probable at the date of acquisition that the Company will not collect all principal and interest payments in accordance with the terms of the loan agreement, the expected shortfall in future cash flows, as compared to the contractual amount due, is recognized as a non-accretable discount. Any excess of expected cash flows over the acquisition date fair value is known as the accretable discount, and is recognized as accretion income over the life of each pool or individual loan. ACI loans that meet the criteria for non-accrual of interest at the time of acquisition may be considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if the timing and expected cash flows on such loans can be reasonably estimated and if collection of the new carrying value of such loans is expected. However, if the timing or amount of the expected cash flows cannot be reasonably estimated an ACI loan may be placed in nonaccruing status. Expected cash flows over the acquisition date fair value are periodically re-estimated utilizing the same cash flow methodology used at the time of acquisition and subsequent decreases to the expected cash flows will generally result in a provision for loan losses charge to the Company’s consolidated statements of income. Conversely, subsequent increases in expected cash flows result in a transfer from the non-accretable discount to the accretable discount, which would have a positive impact on accretion income prospectively. These cash flow evaluations are inherently subjective as they require material estimates, all of which may be susceptible to significant change. FDIC Indemnification Asset An FDIC indemnification asset results from the loss sharing agreement in an FDIC-assisted transaction and is measured separately from the related covered assets as they are not contractually embedded in those assets and are not transferable should the Company choose to dispose of the covered assets. The FDIC indemnification asset represents the estimated fair value of expected reimbursements from the FDIC for losses on covered loans and other real estate owned (“OREO”). As indemnified assets are resolved and the Company is reimbursed by the FDIC for the value of the resolved portion of the FDIC indemnification asset, the Company reduces the carrying value of the FDIC indemnification asset. As of December 31, 2012, the Company had submitted claims in excess of the first threshold of $347 million established at acquisition and was reimbursed the 80% of the covered losses by the FDIC up to this initial threshold. Subsequent claims between $347 million and $504 million are not reimbursable under the loss share agreement. The Company’s claims did not exceed the second threshold of $504 million, over which losses are reimbursed at 80%. On January 5, 2016, a settlement agreement was finalized with the FDIC to terminate the loss share agreement at a nominal cost and the Company had no FDIC indemnification asset recorded as of December 31, 2017 and 2016. Premises and Equipment Premises and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization are determined using the straight-line method at rates calculated to depreciate or amortize the cost of assets over their estimated useful lives. Maintenance and repairs of property and equipment are charged to expense, and major improvements that extend the useful life of the asset are capitalized. Upon retirement, sale, or other disposition of property and equipment, the cost and accumulated depreciation are eliminated from the accounts, and any gains or losses are included in income. The Company leases various premises and equipment under operating leases. The leases have varying terms, with most containing renewal or first-right-of-refusal options for multi-year periods and annual increases in base rates. Leasehold improvements are depreciated over the lesser of the estimated useful life or the lease term. Other Real Estate OREO consists of properties acquired through foreclosure and unutilized bank-owned properties. These properties, as held for sale properties, are recorded at fair value, less estimated costs to sell, on the date of foreclosure establishing a new cost basis for the property. Subsequent to the foreclosure date the OREO is maintained at the lower of cost or fair value. Any write-down to fair value required at the time of foreclosure is charged to the ACL. Subsequent gains or losses on other real estate resulting from the sale of the property or additional valuation allowances required due to further declines in fair value are reported in other noninterest expense. The amount of loans in the process of foreclosure or physical possession for single-family residential properties was $4.4 million and $0.6 million as of December 31, 2017 and 2016, respectively. The amount of residential real estate properties held in OREO was $2.7 million and $5.1 million as of Dece

Securities

Securities	12 Months Ended
	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Securities	Note 2—Securities A summary of amortized cost and estimated fair value of securities available-for-sale and securities held-to-maturity at December 31, 2017 and 2016 is as follows: Gross Gross Amortized Unrealized Unrealized Estimated (In thousands) Cost Gains Losses Fair Value December 31, 2017 Securities available-for-sale: U.S. Treasury securities $ 100,575 $ — $ 3,731 $ 96,844 Obligations of U.S. government agencies 80,552 738 66 81,224 Mortgage-backed securities issued or guaranteed by U.S. agencies (MBS) Residential pass-through: Guaranteed by GNMA 106,461 676 1,110 106,027 Issued by FNMA and FHLMC 431,409 1,284 2,271 430,422 Other residential mortgage-backed securities 47,379 97 1,084 46,392 Commercial mortgage-backed securities 76,201 63 4,069 72,195 Total MBS 661,450 2,120 8,534 655,036 Obligations of states and municipal subdivisions 420,111 7,539 3,691 423,959 Other securities 5,762 286 163 5,885 Total securities available-for-sale $ 1,268,450 $ 10,683 $ 16,185 $ 1,262,948 Securities held-to-maturity: Obligations of states and municipal subdivisions $ 290 $ 21 $ — $ 311 (In thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value December 31, 2016 Securities available-for-sale: U.S. Treasury securities $ 100,736 $ — $ 3,951 $ 96,785 Obligations of U.S. government agencies 97,340 508 320 97,528 Mortgage-backed securities issued or guaranteed by U.S. agencies (MBS) Residential pass-through: Guaranteed by GNMA 152,918 1,401 1,166 153,153 Issued by FNMA and FHLMC 267,035 1,499 3,206 265,328 Other residential mortgage-backed securities 48,076 375 890 47,561 Commercial mortgage-backed securities 66,720 — 4,107 62,613 Total MBS 534,749 3,275 9,369 528,655 Obligations of states and municipal subdivisions 438,655 870 28,713 410,812 Other securities 5,580 149 162 5,567 Total securities available-for-sale $ 1,177,060 $ 4,802 $ 42,515 $ 1,139,347 Securities held-to-maturity: Obligations of states and municipal subdivisions $ 425 $ 38 $ — $ 463 The scheduled contractual maturities of securities available-for-sale and securities held-to-maturity at December 31, 2017 were as follows: Available-for-Sale Held-to-Maturity Amortized Estimated Amortized Estimated (In thousands) Cost Fair Value Cost Fair Value Due in one year or less $ — $ — $ — $ — Due after one year through five years 108,378 104,719 290 311 Due after five years through ten years 19,397 19,653 — — Due after ten years 473,463 477,655 — — Mortgage-backed securities and other securities 667,212 660,921 — — Total $ 1,268,450 $ 1,262,948 $ 290 $ 311 Proceeds from sales, gross gains, and gross losses on sales of securities available for sale for the years ended December 31, 2017, 2016 and 2015 are presented below. There were no other-than-temporary impairment charges included in gross realized losses for the years ended December 31, 2017, 2016 and 2015. The specific identification method is used to reclassify gains and losses out of other comprehensive income at the time of sale. For the Years Ended December 31, (In thousands) 2017 2016 2015 Gross realized gains $ 167 $ 4,172 $ 1,444 Gross realized losses (313 ) (436 ) (273 ) Realized gains (losses) on sale of securities available for sale, net $ (146 ) $ 3,736 $ 1,171 Securities with a carrying value of $507.3 million and $380.4 million at December 31, 2017 and 2016, respectively, were pledged to secure public and trust deposits, FHLB borrowings, repurchase agreements and for other purposes as required or permitted by law. The detail concerning securities classified as available-for-sale with unrealized losses as of December 31, 2017 and 2016 was as follows: Unrealized loss analysis Losses < 12 Months Losses > 12 Months Gross Gross Estimated Unrealized Estimated Unrealized (In thousands) Fair Value Losses Fair Value Losses December 31, 2017 U.S. Treasury securities $ — $ — $ 96,844 $ 3,731 Obligations of U.S. government agencies 1,577 9 14,323 57 MBS 306,274 1,490 172,324 7,044 Obligations of states and municipal subdivisions 2,601 22 134,870 3,669 Other securities — — 4,308 163 Total $ 310,452 $ 1,521 $ 422,669 $ 14,664 Unrealized loss analysis Losses < 12 Months Losses > 12 Months Gross Gross Estimated Unrealized Estimated Unrealized (In thousands) Fair Value Losses Fair Value Losses December 31, 2016 U.S. Treasury securities $ 96,785 $ 3,951 $ — $ — Obligations of U.S. government agencies 51,463 277 12,150 43 MBS 328,374 8,482 17,979 887 Obligations of states and municipal subdivisions 344,708 28,713 — — Other securities — — 4,216 162 Total $ 821,330 $ 41,423 $ 34,345 $ 1,092 There were no securities classified as held-to-maturity with unrealized losses as of December 31, 2017 and 2016. As of December 31, 2017 and 2016, approximately 58% and 75%, respectively, of the fair value of securities in the investment portfolio reflected an unrealized loss. As of December 31, 2017, there were 90 securities that had been in a loss position for more than twelve months, and 39 securities that had been in a loss position for less than 12 months. None of the unrealized losses relate to the marketability of the securities or the issuer’s ability to honor redemption of the obligations. The Company has adequate liquidity and, therefore, does not plan to sell and, more likely than not, will not be required to sell these securities before recovery of the indicated impairment. Accordingly, the unrealized losses on these securities have been determined to be temporary.

Loans and Allowance for Credit

Loans and Allowance for Credit Losses	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Loans and Allowance for Credit Losses	Note 3—Loans and Allowance for Credit Losses The following table presents total loans outstanding by portfolio segment and class of financing receivable as of December 31, 2017 and 2016, respectively. Outstanding balances include Acquired Noncredit Impaired (“ANCI”) loans, originated loans and Acquired Credit Impaired (“ACI”) loans. Information about ACI loans is presented separately in the “Acquired Credit-Impaired Loans” section of this Note. As of December 31, (In thousands) 2017 2016 Commercial and Industrial General C&I $ 2,746,454 $ 2,416,665 Energy sector 935,371 939,369 Restaurant industry 1,035,538 864,085 Healthcare 416,423 445,103 Total commercial and industrial 5,133,786 4,665,222 Commercial Real Estate Income producing 1,082,929 1,001,703 Land and development 75,472 71,004 Total commercial real estate 1,158,401 1,072,707 Consumer Residential real estate 1,690,814 1,457,170 Other 74,922 68,689 Total consumer 1,765,736 1,525,859 Small Business Lending 221,855 193,641 Total (Gross of unearned discount and fees) 8,279,778 7,457,429 Unearned discount and fees (26,351 ) (24,718 ) Total (Net of unearned discount and fees) $ 8,253,427 $ 7,432,711 Allowance for Credit Losses (“ACL”) The ACL is management’s estimate of credit losses inherent in the loan portfolio at the balance sheet date. The Company has an established process to determine the adequacy of the ACL that assesses the losses inherent in our portfolio. While management attributes portions of the ACL to specific portfolio segments, the entire ACL is available to absorb credit losses inherent in the total loan portfolio. The ACL process involves procedures that appropriately consider the unique risk characteristics of the loan portfolio segments based on management’s assessment of the underlying risks and cash flows. For each portfolio segment, losses are estimated collectively for groups of loans with similar characteristics, individually for impaired loans or, for ACI loans, based on the changes in cash flows expected to be collected on a pool or individual basis. The level of the ACL is influenced by loan volumes, risk rating migration, historic loss experience influencing loss factors, and other conditions influencing loss expectations, such as economic conditions. The primary indicator of credit quality for the portfolio segments is its internal risk ratings. The assignment of loan risk ratings is the primary responsibility of the lending officer concurrent with approval from the credit officer reviewing and recommending approval of the credit. Additionally, there is independent review by internal credit review, which also performs ongoing, independent review of the risk management process. The risk management process includes underwriting, documentation and collateral control. Credit review is centralized and independent of the lending function. The credit review results are reported to senior management and the Board of Directors. The following is a summary description of the risk ratings. Tables summarizing the amount of loans by criticized or classified risk rating in each loan portfolio segment is included in the sections “Credit Exposure in the Originated and ANCI Loan Portfolios” and “Credit Exposure in the ACI Portfolio.” • Pass . Loans within this risk rating are further categorized as follows: • Virtually Risk Free —Well-collateralized by cash equivalent instruments held by the Bank or supported by an abundance of repayment sources including liquidity currently sufficient to retire the loan. • Exceptional —Exceptional credits possess very low risk of loss. These loans are generally cash secured or are supported by larger corporate borrowers (with sufficient financial resources to qualify for an upper level investment rating from S&P or Moody’s). • Superior— Superior credits possess a low risk of loss. Superior borrowers possess liquid financial statements supported by superior financial strength and stability, including superior cash flow generation ability and significant levels of liquid assets combined with low to moderate levels of leverage. • Strong— Strong credits possess excellent credit quality supported by excellent, diverse sources of repayment including strong (full cycle) cash flow, persistently excellent liquidity and other assets comprising a strong net worth position that can be converted into liquid assets within the next twelve months. • Above Average— Above average credits are desirable because of their above average credit quality, and are supported by comfortable (full cycle) cash flow coverage, meaningful (currently existing) financial liquidity and moderate financial leverage maintained by financially sound borrowers. • Good —Good credits possess a minor weakness that causes them to possess slightly lower than average credit quality even though they also possess attributes (one or more strengths that can be built on) that make them preferable to satisfactory loans. • Satisfactory —Satisfactory credits generally meet the minimum requirements for an acceptable loan in a broad sense but their overall risk profile causes their credit quality to fall within the bottom quartile of all newly approved loans. • Pass Watch —A “watch” credit is a pass loan for which an additional policy exception may have arisen subsequent to its booking or has been previously extended to a borrower and now shows signs of weakness in the overall base of financial resources available to repay the loan. However, demonstrated mitigating factors exist that contribute to the reduction of the risk of delinquency or loss. • Special Mention— A “special mention” loan has identified potential weaknesses that are of sufficient materiality to require management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the loan or in the Bank’s credit position at some future date. Special mention assets contain greater than acceptable risk to warrant increases in credit exposure and are thus considered non-pass rated credits. • Substandard High— A “substandard high” loan is inadequately protected by the current sound net worth and paying capacity of the obligor or the collateral pledged, if any. Loans classified as substandard high possess well-defined weaknesses that are expected to jeopardize their liquidation but the weaknesses have not progressed to a point where payments on the loan have become consistently late or where repayment is not expected to be protracted relative to contractual terms. Loans in this category are generally in accrual status. • Substandard Low— A “substandard low” loan is inadequately protected by the current sound net worth and paying capacity of the obligor or the collateral pledged, if any. Loans classified as substandard low possess well-defined weaknesses that are expected to jeopardize their liquidation and have progressed to a point where payments on the loan have become consistently late or possess other significant delays for orderly repayment. Loans in this category generally are in nonaccrual status. • Doubtful— Loans classified as “doubtful” possess all of the weaknesses inherent in loans classified as substandard with the added characteristic that the weaknesses make collection or liquidation in full highly questionable or improbable based on currently existing facts, conditions and values. Loans rated as doubtful are not rated as loss because certain events may occur that could salvage the debt. Loans in this category are required to be on nonaccrual. • Loss —Loans classified “loss” are considered uncollectable and of such little value that their continuance as bankable assets is not warranted. This classification does not mean that the asset has absolutely no recovery or salvage value, but rather that it is not practical or desirable to defer writing off this worthless loan even though partial recovery may be affected in the future. Loans may reside in this classification for administrative purposes for a period not to exceed the earlier of thirty (30) days or calendar quarter-end. A summary of the activity in the ACL for each of the three years in the period ended December 31, 2017 is as follows: For the Year Ended December 31, 2017 (In thousands) Commercial and Industrial Commercial Real Estate Consumer Small Business Total As of December 31, 2016 $ 54,688 $ 10,103 $ 13,265 $ 4,212 $ 82,268 Provision for loan losses 5,883 1,737 1,746 369 9,735 Charge-offs (5,645 ) (93 ) (929 ) (204 ) (6,871 ) Recoveries 993 243 901 307 2,444 As of December 31, 2017 $ 55,919 $ 11,990 $ 14,983 $ 4,684 $ 87,576 Allocation of ending ACL ACI loans collectively evaluated for impairment $ 5 $ 2,006 $ 6,289 $ — $ 8,300 ACI loans individually evaluated for impairment — 4 220 — 224 ANCI loans collectively evaluated for impairment 864 130 49 295 1,338 ANCI loans individually evaluated for impairment — — 36 22 58 Originated loans collectively evaluated for impairment 46,591 9,850 8,389 4,362 69,192 Originated loans individually evaluated for impairment 8,459 — — 5 8,464 ACL as of December 31, 2017 $ 55,919 $ 11,990 $ 14,983 $ 4,684 $ 87,576 Loans ACI loans collectively evaluated for impairment $ 19,486 $ 71,675 $ 150,798 $ — $ 241,959 ACI loans individually evaluated for impairment 10,091 8,186 324 — 18,601 ANCI loans collectively evaluated for impairment 58,775 15,926 113,357 11,331 199,389 ANCI loans individually evaluated for impairment — — 1,582 310 1,892 Originated loans collectively evaluated for impairment 4,974,973 1,062,614 1,499,260 209,627 7,746,474 Originated loans individually evaluated for impairment 70,461 — 415 587 71,463 Loans as of December 31, 2017 $ 5,133,786 $ 1,158,401 $ 1,765,736 $ 221,855 $ 8,279,778 For the Year Ended December 31, 2016 (In thousands) Commercial and Industrial Commercial Real Estate Consumer Small Business Total As of December 31, 2015 $ 55,824 $ 8,136 $ 13,450 $ 2,373 $ 79,783 Provision for loan losses 43,782 1,389 1,506 2,671 49,348 Charge-offs (46,367 ) — (2,094 ) (841 ) (49,302 ) Recoveries 1,449 578 403 9 2,439 As of December 31, 2016 $ 54,688 $ 10,103 $ 13,265 $ 4,212 $ 82,268 Allocation of ending ACL ACI loans collectively evaluated for impairment $ 176 $ 2,652 $ 7,215 $ — $ 10,043 ACI loans individually evaluated for impairment — 3 232 — 235 ANCI loans collectively evaluated for impairment 299 243 94 272 908 ANCI loans individually evaluated for impairment — — 37 33 70 Originated loans collectively evaluated for impairment 52,615 7,205 5,687 3,900 69,407 Originated loans individually evaluated for impairment 1,598 — — 7 1,605 ACL as of December 31, 2016 $ 54,688 $ 10,103 $ 13,265 $ 4,212 $ 82,268 Loans ACI loans collectively evaluated for impairment $ 26,276 $ 87,825 $ 187,668 $ — $ 301,769 ACI loans individually evaluated for impairment 11,772 10,345 396 — 22,513 ANCI loans collectively evaluated for impairment 51,694 20,306 151,759 8,769 232,528 ANCI loans individually evaluated for impairment — — 1,168 389 1,557 Originated loans collectively evaluated for impairment 4,424,822 954,231 1,184,442 183,933 6,747,428 Originated loans individually evaluated for impairment 150,658 — 426 550 151,634 Loans as of December 31, 2016 $ 4,665,222 $ 1,072,707 $ 1,525,859 $ 193,641 $ 7,457,429 For the Year Ended December 31, 2015 (In thousands) Commercial and Industrial Commercial Real Estate Consumer Small Business Total As of December 31, 2014 $ 28,930 $ 7,050 $ 15,552 $ 1,988 $ 53,520 Provision for loan losses 35,355 1,018 (1,412 ) 1,023 35,984 Charge-offs (8,525 ) (271 ) (1,291 ) (647 ) (10,734 ) Recoveries 64 339 601 9 1,013 As of December 31, 2015 $ 55,824 $ 8,136 $ 13,450 $ 2,373 $ 79,783 Allocation of ending ACL ACI loans collectively evaluated for impairment $ 2,062 $ 3,084 $ 8,688 $ — $ 13,834 ACI loans individually evaluated for impairment 168 — 332 — 500 ANCI loans collectively evaluated for impairment 425 227 65 285 1,002 ANCI loans individually evaluated for impairment — — 40 21 61 Originated loans collectively evaluated for impairment 48,666 4,825 4,325 2,067 59,883 Originated loans individually evaluated for impairment 4,503 — — — 4,503 ACL as of December 31, 2015 $ 55,824 $ 8,136 $ 13,450 $ 2,373 $ 79,783 Impaired Originated and ANCI Loans Including TDRs The following includes certain key information about individually impaired loans as of December 31, 2017 and 2016. Originated and ANCI Loans Identified as Impaired As of December 31, 2017 (In thousands) Recorded Investment in Impaired Loans (1) Unpaid Principal Balance Related Specific Allowance Nonaccrual Loans Included in Impaired Loans Undisbursed Commitments With no related allowance for credit losses Commercial and Industrial General C&I $ 5,010 $ 4,994 $ — $ 192 $ — Energy sector 14,822 23,307 — 14,822 387 Total commercial and industrial 19,832 28,301 — 15,014 387 Consumer Residential real estate 1,093 1,097 — 35 — Other 416 415 — — — Total consumer 1,509 1,512 — 35 — Small Business Lending 249 695 — 249 — Total $ 21,590 $ 30,508 $ — $ 15,298 $ 387 With allowance for credit losses recorded Commercial and Industrial Energy sector $ 39,857 $ 43,416 $ 8,353 $ 28,000 $ 402 Restaurant industry 11,017 10,969 106 — 2,500 Total commercial and industrial 50,874 54,385 8,459 28,000 2,902 Consumer Residential real estate 496 494 36 — — Small Business Lending 650 921 27 60 — Total $ 52,020 $ 55,800 $ 8,522 $ 28,060 $ 2,902 As of December 31, 2016 (In thousands) Recorded Investment in Impaired Loans (1) Unpaid Principal Balance Related Specific Allowance Nonaccrual Loans Included in Impaired Loans Undisbursed Commitments With no related allowance for credit losses Commercial and Industrial General C&I $ 12,334 $ 13,426 $ — $ 6,838 $ 1,363 Energy sector 99,200 103,322 — 85,149 8,465 Total commercial and industrial 111,534 116,748 — 91,987 9,828 Consumer Residential real estate 437 435 — — — Other 429 427 — — 1 Total consumer 866 862 — — 1 Small Business Lending 299 703 — 299 — Total $ 112,699 $ 118,313 $ — $ 92,286 $ 9,829 With allowance for credit losses recorded Commercial and Industrial Energy sector $ 39,319 $ 45,243 $ 1,598 $ 28,228 $ 4,788 Consumer Residential real estate 736 741 37 39 — Small Business Lending 641 897 40 90 — Total $ 40,696 $ 46,881 $ 1,675 $ 28,357 $ 4,788 (1) The recorded investment of a loan also includes any interest receivable, net unearned discount or fees, and unamortized premium or discount. The related amount of interest income recognized for impaired loans was $1.6 million for the year ended December 31, 2017, compared to $1.4 million and $0.8 million for the same periods in 2016 and 2015, respectively. Generally, cash receipts on nonperforming loans are used to reduce principal rather than recorded as interest income. Past due status is determined based upon contractual terms. A nonaccrual loan may be returned to accrual status when repayment is reasonably assured and there has been demonstrated performance under the terms of the loan or, if applicable, under the terms of the restructured loan. Approximately $1.5 million of contractual interest paid was recognized on the cash basis for the year ended December 31, 2017, compared to $1.1 million and zero for same periods in 2016 and 2015, respectively. Average Recorded Investment in Impaired Originated and ANCI Loans Year Ended December 31, (In thousands) 2017 2016 2015 Commercial and Industrial General C&I $ 8,586 $ 11,291 $ 6,347 Energy sector 108,751 158,192 20,105 Restaurant industry 2,203 — — Total commercial and industrial 119,540 169,483 26,452 Consumer Residential real estate 1,426 1,206 1,567 Other 386 398 273 Total consumer 1,812 1,604 1,840 Small Business Lending 945 547 723 Total $ 122,297 $ 171,634 $ 29,015 Included in impaired loans are loans considered to be TDRs. The Company attempts to work with borrowers when necessary to extend or modify loan terms to better align with the borrower’s ability to repay. Extensions and modifications to loans are made in accordance with internal policies and guidelines which conform to regulatory guidance. Each occurrence is unique to the borrower and is evaluated separately. The Bank considers regulatory guidelines when restructuring loans to ensure that prudent lending practices are followed. Qualifying criteria and payment terms are structured by the borrower’s current and prospective ability to comply with the modified terms of the loan. A modification is classified as a TDR if the borrower is experiencing financial difficulty and it is determined that the Company has granted a concession to the borrower. The Company may determine that a borrower is experiencing financial difficulty if the borrower is currently in default on any of its debt, or if it is probable that a borrower may default in the foreseeable future without the modification. Concessions could include reductions of interest rates at a rate lower than current market rate for a new loan with similar risk, All TDRs are reported as impaired. Impaired classification may be removed if the borrower demonstrates compliance with the modified terms and the restructuring agreement specifies an interest rate equal to that which would be provided to a borrower with similar credit at the time of restructuring. The majority of TDRs are classified as impaired loans for the remaining life of the loan. Nonperforming loans and impaired loans are defined differently. Some loans may be included in both categories, whereas other loans may only be included in one category. Originated and ANCI Loans that were modified into TDRs For the Year Ended December 31, 2017 2016 2015 (In thousands) Number of TDRs Recorded Investment Number of TDRs Recorded Investment Number of TDRs Recorded Investment Commercial and Industrial 3 $ 16,027 6 $ 43,609 5 $ 26,459 Consumer 2 739 2 534 6 579 Small Business Lending 1 138 1 552 — — Total 6 $ 16,904 9 $ 44,695 11 $ 27,038 There were no TDRs experiencing payment default during the years ended December 31, 2017 and 2016. For the year ended December 31, 2015 there were two small business lending loans with a combined recorded investment of $459 thousand which experienced payment default. Default is defined as the earlier of the troubled debt restructuring being placed on non-accrual status or obtaining 90 day past due status with respect to principal and/or interest payments. For the Year Ended December 31, 2017 2016 2015 Number of Loans Modified by: Rate Concession Modified Terms and/ or Other Concessions Forbearance Agreement Rate Concession Modified Terms and/ or Other Concessions Rate Concession Modified Terms and/ or Other Concessions Commercial and Industrial 2 1 2 1 3 — 5 Consumer — 2 — — 2 5 1 Small Business Lending 1 — — 1 — — — Total 3 3 2 2 5 5 6 Residential Mortgage Loans in Process of Foreclosure Included in loans are $4.4 million and $2.1 million of consumer loans secured by single family residential real estate that are in process of foreclosure at December 31, 2017 and 2016, respectively. Loans in process of foreclosure include those for which formal foreclosure proceedings are in process according to local requirements of the applicable jurisdiction. In addition to the single family residential real estate loans in process of foreclosure, the Company also held $2.7 million and $5.1 million of foreclosed single family residential properties in other real estate owned as of December 31, 2017 and 2016. Credit Exposure in the Originated and ANCI Loan Portfolios The following provides information regarding the credit exposure by portfolio segment and class of receivable as of December 31, 2017 and 2016: As of December 31, 2017 (Recorded Investment in thousands) Special Mention Substandard Doubtful Total Criticized / Classified Commercial and Industrial General C&I $ 80,550 $ 47,324 $ — $ 127,874 Energy sector — 99,979 7,634 107,613 Restaurant industry 4,536 12,506 — 17,042 Healthcare — 71 — 71 Total commercial and industrial 85,086 159,880 7,634 252,600 Commercial Real Estate Income producing — 26 — 26 Land and development 20 — — 20 Total commercial real estate 20 26 — 46 Consumer Residential real estate 7,610 12,416 — 20,026 Other 673 356 4 1,033 Total consumer 8,283 12,772 4 21,059 Small Business Lending 3,480 1,375 27 4,882 Total $ 96,869 $ 174,053 $ 7,665 $ 278,587 As of December 31, 2016 (Recorded Investment in thousands) Special Mention Substandard Doubtful Total Criticized / Classified Commercial and Industrial General C&I $ 36,419 $ 27,489 $ — $ 63,908 Energy sector 30,433 239,457 789 270,679 Restaurant industry 16,169 — — 16,169 Healthcare 9,479 — — 9,479 Total commercial and industrial 92,500 266,946 789 360,235 Commercial Real Estate Income producing — — — — Land and development 23 341 — 364 Total commercial real estate 23 341 — 364 Consumer Residential real estate 2,578 3,871 — 6,449 Other 508 419 — 927 Total consumer 3,086 4,290 — 7,376 Small Business Lending 1,818 1,880 — 3,698 Total $ 97,427 $ 273,457 $ 789 $ 371,673 The following provides an aging of past due loans by portfolio segment and class of receivable as of December 31, 2017 and 2016: Aging of Past Due Originated and ANCI Loans As of December 31, 2017 Accruing Loans Non-Accruing Loans (Recorded Investment in thousands) 30-59 DPD 60-89 DPD 90+DPD 0-29 DPD 30-59 DPD 60-89 DPD 90+DPD Commercial and Industrial General C&I $ 59 $ — $ 476 $ — $ 192 $ — $ — Energy sector — — — 32,315 — — 10,507 Healthcare — — — — 71 — - Total commercial and industrial 59 — 476 32,315 263 — 10,507 Commercial Real Estate Income producing — — 26 — — — — Land and development 55 — — — — — — Total commercial real estate 55 — 26 — — — — Consumer Residential real estate 3,191 1,030 325 1,070 173 293 2,205 Other 532 3 — — — — — Total consumer 3,723 1,033 325 1,070 173 293 2,205 Small Business Lending 931 328 — 110 38 — 494 Total $ 4,768 $ 1,361 $ 827 $ 33,495 $ 474 $ 293 $ 13,206 As of December 31, 2016 Accruing Loans Non-Accruing Loans (Recorded Investment in thousands) 30-59 DPD 60-89 DPD 90+DPD 0-29 DPD 30-59 DPD 60-89 DPD 90+DPD Commercial and Industrial General C&I $ 3,930 $ — $ — $ 125 $ 6,839 $ — $ 250 Energy sector — — — 112,937 — — 447 Total commercial and industrial 3,930 — — 113,062 6,839 — 697 Commercial Real Estate Income producing 4 — — — — — — Land and development 259 — — — — 341 — Total commercial and industrial 263 — — — — 341 — Consumer Residential real estate 2,910 1,078 496 1,427 30 — 2,073 Other 552 — 3 — — — — Total consumer 3,462 1,078 499 1,427 30 — 2,073 Small Business Lending 2,003 563 87 560 78 36 131 Total $ 9,658 $ 1,641 $ 586 $ 115,049 $ 6,947 $ 377 $ 2,901 Acquired Credit Impaired (“ACI”) Loans The following table presents total ACI loans outstanding by portfolio segment and class of financing receivable as of December 31, 2017 and 2016. As of December 31, (In thousands) 2017 2016 Commercial and Industrial General C&I $ 23,428 $ 31,709 Healthcare 6,149 6,338 Total commercial and industrial 29,577 38,047 Commercial Real Estate Income producing 79,861 96,673 Land and development — 1,497 Total commercial real estate 79,861 98,170 Consumer Residential real estate 149,942 186,375 Other 1,180 1,690 Total consumer 151,122 188,065 Total $ 260,560 $ 324,282 The excess of cash flows expected to be collected over the carrying value of ACI loans is referred to as the accretable yield and is recognized in interest income using an effective yield method over the remaining life of the loan, or pools of loans. The accretable yield is affected by: • Changes in interest rate indices for variable rate ACI loans—Expected future cash flows are based on the variable rates in effect at the time of the regular evaluations of cash flows expected to be collected; • Changes in prepayment assumptions—Prepayments affect the estimated life of ACI loans which may change the amount of interest income, and possibly principal, expected to be collected; and • Changes in the expected principal and interest payments over the estimated life—Updates to expected cash flows are driven by the credit outlook and actions taken with borrowers. Changes in the amount of accretable discount for ACI loans for each of the years in the period ended December 31, 2017: Changes in Accretable Yield on ACI Loans For the Year Ended December 31, (In thousands) 2017 2016 2015 Balance at beginning of period $ 98,728 $ 122,791 $ 163,631 Maturities/payoff (9,888 ) (11,563 ) (24,196 ) Charge-offs (129 ) (286 ) (183 ) Foreclosure (1,061 ) (1,041 ) (1,290 ) Accretion (23,303 ) (30,870 ) (46,042 ) Reclass from nonaccretable difference due to increases in expected cash flow 14,075 19,697 30,871 Balance at end of period $ 78,422 $ 98,728 $ 122,791 Impaired ACI Loans and Pools Including TDRs The following includes certain key information about individually impaired ACI loans and pooled ACI loans as of and for the years ended December 31, 2017 and 2016. ACI Loans / Pools Identified as Impaired As of December 31, 2017 ACI Loans / Pools Identified as Impaired (In thousands) Recorded Investment in Impaired Loans (1) Unpaid Principal Balance Related Specific Allowance Nonaccrual Loans Included in Impaired Loans Undisbursed Commitments Commercial and Industrial $ 13,541 $ 17,630 $ 5 $ — $ — Commercial Real Estate 82,856 112,330 2,010 225 — Consumer 18,603 22,064 6,509 — — Total $ 115,000 $ 152,024 $ 8,524 $ 225 $ — As of December 31, 2016 ACI Loans / Pools Identified as Impaired (In thousands) Recorded Investment in Impaired Loans (1) Unpaid Principal Balance Related Specific Allowance Nonaccrual Loans Included in Impaired Loans Undisbursed Commitments Commercial and Industrial $ 15,552 $ 28,256 $ 176 $ 1,818 $ — Commercial Real Estate 53,428 82,946 2,654 1,845 1,213 Consumer 44,295 50,175 7,447 — 15 Total $ 113,275 $ 161,377 $ 10,277 $ 3,663 $ 1,228 (1) The recorded investment of a loan also includes any interest receivable, net unearned discount or fees, and unamortized premium or discount. ACI Loans that Were Modified into TDRs There were no ACI loans modified into a TDR for the year ended December 31, 2017. In the year ended December 31, 2016, there was one ACI loan modified into a TDR with a recorded investment of $954 thousand. There were no ACI TDRs experiencing payment default during the three years in the period ended December 31, 2017. Default is defined as the earlier of the troubled debt restructuring being placed on non-accrual status or obtaining 90 day past due status with respect to principal and interest payments. Credit Exposure in the ACI Portfolio The following provides information regarding the credit exposure by portfolio segment and class of receivable as of December 31, 2017 and December 31, 2016: ACI Loans by Risk Rating As of December 31, 2017 2016 (Recorded Investment in thousands) Special Mention Substandard Doubtful Special Mention Substandard Doubtful Commercial and Industrial General C&I $ 737 $ 1,173 $ 37 $ 939 $ 5,484 $ 33 Healthcare — 6,148 — — — — Total commercial and industrial 737 7,321 37 939 5,484 33 Commercial Real Estate Income producing 1,446 4,425 — 5,813 13,591 — Land and development 733 2,090 — 933 3,240 — Total commercial real estate 2,179 6,515 — 6,746 16,831 — Consumer Residential real estate 3,900 22,635 — 3,655 27,586 — Other 114 417 — 14 287 — Total consumer 4,014 23,052 — 3,669 27,873 — Total $ 6,930 $ 36,888 $ 37 $ 11,354 $ 50,188 $ 33 ACI Consumer credit exposure, based on past due status: As of December 31, 2017 2016 (Recorded Investment in thousands) Residential Real Estate Other Residential Real Estate Other 0 – 29 Days Past Due $ 139,662 $ 1,356 $ 171,457 $ 1,871 30 – 59 Days Past Due 2,299 120 4,070 134 60 – 89 Days Past Due 2,496 62 1,939 25 90 – 119 Days Past Due 399 — 622 36 120 + Days Past Due 7,480 45 10,915 56 Total $ 152,336 $ 1,583 $ 189,003 $ 2,122

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Premises and Equipment	Note 4—Premises and Equipment Premises and equipment are stated at cost, less accumulated depreciation and amortization, as follows: December 31, (In thousands) Estimated Useful Life in Years 2017 2016 Premises: Land — $ 16,875 $ 16,875 Buildings, construction and improvements (1) 2-40 53,620 52,263 Total premises 70,495 69,138 Equipment 3-10 34,123 31,984 Total premises and equipment 104,618 101,122 Less: Accumulated depreciation and amortization (41,186 ) (34,446 ) Total premises and equipment, net $ 63,432 $ 66,676 (1) Leasehold improvements are depreciated over the lesser of the estimated useful life or the lease term. The amount charged to operating expenses for depreciation was approximately $7.1 million, $6.7 million and $7.2 million for 2017, 2016 and 2015, respectively. Included in other assets is net software cost totaling $4.0 million and $3.4 million as of December 31, 2017 and 2016, respectively. The amount charged to operating expenses for software amortization was $1.9 million, $1.7 million and $1.8 million for the years ended December 31, 2017, 2016 and 2015, respectively. The Company leases various premises and equipment under operating leases. The leases have varying terms, with most containing renewal or first-right-of-refusal options for multi-year periods and annual increases in base rates. The following is a schedule by year of future minimum lease payments under operating leases, as of December 31, 2017: Year Property Equipment Total (In thousands) 2018 $ 9,724 $ 342 $ 10,066 2019 9,542 187 9,729 2020 8,544 44 8,588 2021 7,794 — 7,794 2022 5,575 — 5,575 Thereafter 8,949 — 8,949 Total minimum lease payments $ 50,128 $ 573 $ 50,701 Rental expense for premises and equipment, net of rental income, for the years ended December 31, 2017, 2016 and 2015, was approximately $11.2 million, $11.1 million and $13.4 million, respectively. The major portion of equipment rental expense is related to office equipment and is paid on a month-to-month basis.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Note 5—Goodwill and Other Intangible Assets The following table summarizes the Company’s goodwill and other intangible assets at December 31, 2017 and 2016: December 31, (In thousands) 2017 2016 Goodwill $ 317,817 $ 317,817 Core deposit intangible, net of accumulated amortization of $38,091 and $35,495, respectively 1,595 4,191 Customer lists, net of accumulated amortization of $18,097 and $16,041, respectively 8,604 10,659 Trademarks 24 24 Total goodwill and intangible assets $ 328,040 $ 332,691

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivatives	Note 6—Derivatives The Company primarily uses derivatives to manage exposure to market risk, including interest rate risk, credit risk and foreign currency risk, and to assist customers with their risk management objectives. Management will designate certain derivatives as hedging instruments in a qualifying hedge accounting relationship. The Company’s remaining derivatives consist of economic hedges that do not qualify for hedge accounting and derivatives held for customer accommodation, or other purposes. The fair value of derivative positions outstanding is included in other assets and other liabilities in the accompanying consolidated balance sheets and in the net change in each of these financial statement line items in the accompanying consolidated statements of cash flows. For derivatives not designated as hedging instruments, gains and losses due to changes in fair value are included in noninterest income and the operating section of the consolidated statement of cash flows. For derivatives designated as hedging instruments, the effective portion of the gain or loss related to the derivative instrument is recognized as a component of other comprehensive income and subsequently reclassified as interest income when the forecasted transaction affects income. The ineffective portion of the gain or loss is recognized immediately as noninterest income. The notional amounts and estimated fair values as of December 31, 2017 and 2016 were as follows: December 31, 2017 December 31, 2016 Fair Value Fair Value (In thousands) Notional Amount Other Assets Other Liabilities Notional Amount Other Assets Other Liabilities Derivatives designated as hedging instruments (cash flow hedges): Commercial loan interest rate swaps $ 1,032,000 $ — $ 21,394 $ 1,332,000 $ 1,184 $ 17,225 Derivatives not designated as hedging instruments: Commercial loan interest rate swaps 737,533 2,056 2,056 474,923 2,877 2,877 Commercial loan interest rate caps 186,290 153 153 286,959 94 94 Commercial loan interest rate floors 330,764 1,054 1,054 51,878 118 118 Mortgage loan held for sale interest rate lock commitments 6,119 50 — 3,788 88 — Mortgage loan forward sale commitments 4,565 10 — 7,724 — 46 Mortgage loan held for sale floating commitments 11,800 — — 5,895 — — Foreign exchange contracts 41,688 635 623 — — — Total derivatives not designated as hedging instruments 1,318,759 3,958 3,886 831,167 3,177 3,135 Total derivatives $ 2,350,759 $ 3,958 $ 25,280 $ 2,163,167 $ 4,361 $ 20,360 The Company is party to collateral support agreements with certain derivative counterparties. Such agreements require that the Company maintain collateral based on the fair values of derivative transactions. In the event of default by the Company, the counterparty would be entitled to the collateral. At December 31, 2017 and 2016, the Company was required to post $20.1 million and $20.3 Gain (loss) included in the consolidated statements of income related to derivative instruments for each of the three years ended December 31, 2017: For the Year Ended December 31, 2017 2016 2015 (In thousands) OCI Reclassified from AOCI to interest income Noninterest income OCI Reclassified from AOCI to interest income Noninterest income OCI Reclassified from AOCI to interest income Noninterest income Derivatives designated as hedging instruments (cash flow hedges): Commercial loan interest rate swaps $ (1,426 ) $ 3,705 $ — $ (7,444 ) $ 11,255 $ 166 $ 7,454 $ 4,877 $ (329 ) Derivatives not designated as hedging instruments: Mortgage loan held for sale interest rate lock commitments $ — $ — $ (39 ) $ — $ — $ 24 $ — $ — $ (66 ) Foreign exchange contracts — — 2,271 — — 1,264 — — 965 Interest Rate Swap, Floor and Cap Agreements not designated as hedging derivatives The Company enters into certain interest rate swap, floor and cap agreements on commercial loans that are not designated as hedging instruments. These derivative contracts relate to transactions in which the Company enters into an interest rate swap, floor or cap with a loan customer while at the same time entering into an offsetting interest rate swap or cap with another financial institution. In connection with each swap transaction, the Company agrees to pay interest to the customer on a notional amount at a variable interest rate and receive interest from the customer on a similar notional amount at a fixed interest rate. At the same time, the Company agrees to pay another financial institution the same fixed interest rate on the same notional amount and receive the same variable interest rate on the same notional amount. The interest rate swap transaction allows the Company’s customer to effectively convert a variable rate loan to a fixed rate. The interest rate cap transaction allows the Company’s customer to minimize interest rate risk exposure to rising interest rates. Because the Company acts as an intermediary for its customer, changes in the fair value of the underlying derivative contracts for the most part offset each other and do not significantly impact the Company’s consolidated statements of income. The Company is exposed to credit loss in the event of nonperformance by the parties to the interest rate swap and cap agreements. However, the Company does not anticipate nonperformance by the counterparties. The estimated fair value has been recorded as an asset and a corresponding liability in the accompanying consolidated balance sheets as of December 31, 2017 and 2016. Cash Flow Hedges Cash flow hedge relationships mitigate exposure to the variability of future cash flows or other forecasted transactions. The Company uses interest rate swaps to manage overall cash flow changes related to interest rate risk exposure on benchmark interest rate loans. In June 2015 and March 2016, the Company entered into the following interest rate swap agreements to manage overall cash flow changes related to interest rate risk exposure on benchmark interest rate loans. On December 29, 2017, an interest rate swap agreement matured with a notional amount of $300 million. Effective Date Maturity Date Notional Amount (In Thousands) Fixed Rate Variable Rate June 15, 2015 December 17, 2018 $ 382,000 1.3250 % 1 Month LIBOR June 30, 2015 December 31, 2019 300,000 1.5120 1 Month LIBOR March 8, 2016 February 27, 2026 175,000 1.5995 1 Month LIBOR March 8, 2016 February 27, 2026 175,000 1.5890 1 Month LIBOR Based on our current interest rate forecast, $6.4 million of deferred net loss on derivatives in OCI at December 31, 2017 is estimated to be reclassified into net interest income during the next twelve months due to the receipt of interest payments. Future changes to interest rates may significantly change actual amounts reclassified to income. There were no reclassifications into income during 2017, 2016 or 2015 as a result of any discontinuance of cash flow hedges because the forecasted transaction was no longer probable. The maximum length of time over which the Company is hedging a portion of its exposure to the variability in future cash flows for forecasted transactions is approximately eight years as of December 31, 2017.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Banking And Thrift [Abstract]
Deposits	Note 7—Deposits Domestic time deposits $250,000 and over were $382.4 million and $318.8 million at December 31, 2017 and 2016, respectively. There were no foreign time deposits at either December 31, 2017 or 2016. At December 31, 2017, the scheduled maturities of time deposits included in interest-bearing deposits were as follows. (In thousands) December 31, 2017 2018 $ 1,284,285 2019 515,511 2020 89,364 2021 16,678 2022 10,455 Thereafter 44 Total $ 1,916,337

Borrowed Funds

Borrowed Funds	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Borrowed Funds	Note 8—Borrowed Funds Repurchase Agreements Securities sold under agreements to repurchase generally mature within one to seven days from the transaction date. Securities underlying the repurchase agreements remain under the control of the Company. Information concerning the Company’s securities sold under agreements to repurchase as of December 31, 2017 and 2016 is summarized as follows: December 31, (In thousands) 2017 2016 Balance at period end $ 1,026 $ 3,494 Average balance during the period 3,371 5,948 Average interest rate during the period 0.25 % 0.19 % Maximum month-end balance during the period $ 6,286 $ 8,031 Repurchase agreements are treated as collateralized financing obligations and are reflected as a liability in the consolidated balance sheets. Senior and Subordinated Debt In June 2014, the Company and the Bank completed an unregistered $245 million multi-tranche debt transaction and in March 2015, the Company completed an unregistered $50 million debt transaction. These transactions enhanced our liquidity and the Bank’s capital levels to support balance sheet growth. Details of the debt transactions are as follows: December 31, (In thousands) 2017 2016 Cadence Bancorporation: 4.875% senior notes, due June 28, 2019 $ 145,000 $ 145,000 5.375% senior notes, due June 28, 2021 50,000 50,000 7.250% subordinated notes, due June 28, 2029, callable in 2024 35,000 35,000 6.500% subordinated notes, due March 2025, callable in 2020 40,000 40,000 Total long-term debt—Cadence Bancorporation 270,000 270,000 Cadence Bank: 6.250% subordinated notes, due June 28, 2029, callable in 2024 25,000 25,000 Debt issuance cost and unamortized premium (1,606 ) (2,693 ) Purchased 4.875% senior notes, due June 28, 2019 (10,078 ) (78 ) Total long-term debt $ 283,316 $ 292,229 The senior transactions were structured with 4 and 7 year maturities to provide holding company liquidity and to stagger the Company’s debt maturity profile. The $35 million and $25 million subordinated debt transactions were structured with a 15 year maturity, 10 year call options, and fixed-to-floating interest rates in order to maximize regulatory capital treatment. These subordinated debt structures were designed to achieve full Tier 2 capital treatment for 10 years. The $40 million subordinated debt transaction has a 5 year call option. The Company’s senior notes are unsecured, unsubordinated obligations and are equal in right of payment to all of the Company’s other unsecured debt. The Company’s subordinated notes are unsecured obligations and will be subordinated in right of payment to all of the Company’s senior indebtedness and general creditors and to depositors at the Bank. The Company’s senior notes and subordinated notes are not guaranteed by any subsidiary of the Company, including the Bank. The Bank’s subordinated notes are unsecured obligations and are subordinated in right of payment to all of the Bank’s senior indebtedness and general creditors and to depositors of the Bank. The Bank’s subordinated notes are not guaranteed by the Company or any subsidiary of the Bank. Payment of principal on the Company’s and Bank’s subordinated notes may be accelerated by holders of such subordinated notes only in the case of certain insolvency events. There is no right of acceleration under the subordinated notes in the case of default. The Company and/or the Bank may be required to obtain the prior written approval of the Federal Reserve, and, in the case of the Bank, the OCC, before it may repay the subordinated notes issued thereby upon acceleration or otherwise. Junior Subordinated Debentures In conjunction with the Company’s acquisition of Cadence Financial Corporation and Encore Bank, N.A., the junior subordinated debentures were marked to their fair value as of their respective acquisition dates. The related mark is being amortized over the remaining term of the junior subordinated debentures. The following is a list of junior subordinated debt: December 31, (In thousands) 2017 2016 Junior subordinated debentures, 3 month LIBOR plus 2.85%, due 2033 $ 30,000 $ 30,000 Junior subordinated debentures, 3 month LIBOR plus 2.95%, due 2033 5,155 5,155 Junior subordinated debentures, 3 month LIBOR plus 1.75%, due 2037 15,464 15,464 Total par value $ 50,619 $ 50,619 Purchase accounting adjustment, net of amortization (14,147 ) (14,630 ) Total junior subordinated debentures $ 36,472 $ 35,989 Advances from FHLB and Borrowings from FRB FHLB advances are collateralized by deposits with the FHLB, FHLB stock and loans. FHLB advances were $150 million as of December 31, 2017. These advances matured in January 2018. There were no outstanding FHLB advances as of December 31, 2016. Any advances are collateralized by $1.4 billion of commercial and residential real estate loans pledged under a blanket lien arrangement as of December 31, 2017. As of December 31, 2017 and 2016, the FHLB has issued for the benefit of the Bank irrevocable letters of credit totaling $386.5 million. The Bank has a $35 million irrevocable letter of credit in favor of the State of Alabama SAFE Program to secure certain deposits of the State of Alabama. This letter of credit expires September 27, 2018 upon 45 days’ prior notice of non-renewal; otherwise it automatically extends for a successive one-year term. The Bank also has a $350 million irrevocable letter of credit to secure a large treasury management deposit. This letter of credit expires May 26, 2018 upon 45 days’ prior notice of non-renewal; otherwise it automatically extends for a successive one-year term. There were no borrowings from the FRB discount window as of December 31, 2017 and 2016. Any borrowings from the FRB will be collateralized by $738.4 million in commercial loans pledged under a borrower-in-custody arrangement.

Other Noninterest Income and Ot

Other Noninterest Income and Other Noninterest Expense	12 Months Ended
	Dec. 31, 2017
Other Nonoperating Income Expense [Abstract]
Other Noninterest Income and Other Noninterest Expense	Note 9—Other Noninterest Income and Other Noninterest Expense The detail of the other noninterest income and other noninterest expense captions presented in the consolidated statements of income is as follows: For the Year Ended December 31, (In thousands) 2017 2016 2015 Other noninterest income Insurance revenue $ 7,378 $ 7,717 $ 7,107 Bankcard fees 7,310 7,270 7,213 Income from bank owned life insurance policies 3,313 2,954 2,994 Other 6,655 (263 ) (2,297 ) Total other noninterest income $ 24,656 $ 17,678 $ 15,017 For the Year Ended December 31, (In thousands) 2017 2016 2015 Other noninterest expense Net cost of operation of other real estate owned $ 2,251 $ 3,033 $ 5,238 Data processing expense 7,590 6,280 6,092 Special asset expenses 1,156 1,788 3,000 Consulting and professional fees 9,090 6,728 5,671 Loan related expenses 2,379 3,114 3,745 FDIC insurance 4,275 7,228 5,027 Communications 2,837 2,656 3,249 Advertising and public relations 2,048 1,369 2,295 Legal expenses 4,178 2,721 3,159 Branch closure expenses 198 238 2,074 Other 24,663 25,443 26,306 Total other noninterest expense $ 60,665 $ 60,598 $ 65,856

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Note 10—Income Taxes The Tax Cut and Jobs Act (“Tax Reform”) enacted on December 22, 2017 reduced the U.S. federal statutory income tax rate from 35% to 21% effective January 1, 2018. As a result of the new law, the Company recorded a $19.0 million write-off of the Company’s net deferred tax asset, which was recorded as additional income tax expense in the fourth quarter of 2017. The components of the consolidated income tax expense are as follows: For the Year Ended December 31, (In thousands) 2017 2016 2015 Current: Federal $ 33,799 $ 24,394 $ 22,024 State 2,458 2,166 1,013 Total current expense 36,257 26,560 23,037 Deferred: Federal 44,009 5,439 (3,266 ) State 380 541 338 Total deferred (benefit) expense 44,389 5,980 (2,928 ) Total income tax expense $ 80,646 $ 32,540 $ 20,109 A reconciliation of total income tax expense for each of the years in the period ended December 31 2017 to amounts determined by applying the statutory Federal income tax rate of 35% to income before taxes is as follows: For the Year Ended December 31, (In thousands) 2017 2016 2015 Computed income tax expense at statutory rate $ 64,050 $ 34,410 $ 20,778 Effects of tax reform 19,022 — — Tax exempt interest, net (3,988 ) (2,744 ) (842 ) BOLI income (1,148 ) (1,023 ) (1,037 ) State tax expense 2,279 1,760 878 Tax credits (384 ) (266 ) (243 ) Management compensation 116 210 353 Other, net 699 193 222 Total income tax expense $ 80,646 $ 32,540 $ 20,109 As a result of Tax Reform enacted on December 22, 2017, deferred taxes are based on the newly enacted U.S. federal statutory income tax rate of 21%. Deferred taxes as of December 31, 2016 are based on the previously enacted U.S. statutory federal income tax rate of 35%. The provisional amount recorded related to the remeasurement of the Company’s deferred tax asset was $19.0 million, which was recorded as income tax expense. Based on the information available and our current interpretation of Tax Reform, the Company has made reasonable estimates of the impact from the reduction in the U.S. federal statutory rate on the remeasurement of the deferred tax asset. However, the Company’s deferred tax asset will continue to be evaluated in the context of Tax Reform, and may change as a result of evolving management interpretations, elections, and assumptions, as well as new guidance that may be issued by the Internal Revenue Service. Accordingly, the income tax expense of $19.0 million relating to the effects from Tax Reform is considered provisional, as defined by SAB 118. Management expects to complete its analysis within the measurement period in accordance with SAB 118. The significant components of the Company’s deferred tax assets and liabilities as of December 31, 2017 and 2016 are as follows: As of December 31, (In thousands) 2017 2016 Deferred income tax assets: Allowance for credit losses $ 18,464 $ 30,710 Nonaccrual interest — 7,410 Deferred compensation 3,440 3,681 Accrued compensation 2,506 7,962 Net operating loss carryforwards 9,859 16,154 Alternative minimum tax credit carryover 978 978 Unrealized loss on securities, net 1,271 13,829 Unrealized loss on derivative instruments 4,912 5,911 Other 5,344 9,320 Excess of tax basis in assets acquired: Loans 841 8,673 Other real estate owned 13 1,342 Other — 4 Total deferred income tax assets 47,628 105,974 Deferred income tax liabilities: Difference in book and tax basis of intangibles 1,927 4,268 Other 4,213 4,564 Excess of book basis in assets acquired and tax liabilities assumed over book carrying value: Intangibles 7,122 7,798 Other 3,592 5,682 Total deferred income tax liabilities 16,854 22,312 Net deferred income tax asset $ 30,774 $ 83,662 A SC Topic 740, “Income Taxes,” requires that deferred tax assets be reduced if it is more likely than not that some portion or all of the deferred tax asset will not be realized. Management’s determination of the realizability of deferred tax assets is based on its evaluation of all available evidence both positive and negative, and its expectation regarding various future events, including the reversal of deferred tax liabilities, projected future taxable income and tax planning strategies. Positive evidence supporting the realization of the Company’s deferred tax assets at December 31, 2017, includes generation of taxable income since 2012, the Company’s strong capital position, as well as sufficient amounts of projected future taxable income, of the appropriate character, to support the realization of the $30.8 million at December 31, 2017. In order to fully realize the deferred tax asset, the Company will need to general future taxable income of $169.9 million before the end of the statutory net operating loss carryforward period. Based on the assessment of all positive and negative evidence at December 31, 2017 and 2016, management has concluded that it is more likely than not that the results of future operations will generate sufficient taxable income realize the deferred tax assets. Management’s estimate of future taxable income is based on internal projections, various internal assumptions, as well as certain external data all of which management believes to be reasonable although inherently subject to significant judgment. Projected future taxable income is primarily expected to be generated through loan growth at the bank, investment strategies and revenue from successful cross initiatives and the control of expenses through operating effectiveness, all in the context of a macro-economic environment that continues to trend favorably. If actual results differ significantly from the current estimates of future taxable income, a valuation allowance may need to be recorded for some portion or all of the net deferred tax asset. Such an increase to the deferred tax asset valuation allowance could have a material adverse effect on the Company’s consolidated balance sheets and consolidated statements of income. The acquisitions of Cadence Financial Corporation and Encore resulted in an "ownership change" as defined for U.S. federal income tax purposes under Section 382 of the Internal Revenue Code. As a result of the operation of Section 382, the Company is not able to fully utilize a portion of our U.S. federal and state tax net operating losses and certain built-in losses that have not been recognized for tax purposes. An ownership change under Section 382 generally occurs when a change in the aggregate percentage ownership of the stock of the corporation held by five percent stockholders increases by more than fifty percentage points over a rolling three-year period. A corporation experiencing an ownership change generally is subject to an annual limitation on its utilization of pre-change losses and certain post-change recognized built-in losses equal to the value of the stock of the corporation immediately before the ownership change, multiplied by the long-term tax-exempt rate (subject to certain adjustments). The annual limitation is increased each year to the extent that there is an unused limitation in a prior year. Since U.S. federal net operating losses generally may be carried forward for up to 20 years, the annual limitation also effectively provides a cap on the cumulative amount of pre-change losses and certain post-change recognized built-in losses that may be utilized. Pre-change losses and certain post-change recognized built-in losses in excess of the cap are effectively unable to be used to reduce future taxable income. The Company has estimated the amount of pre-change losses and certain post-change losses that are not expected to be utilized and has reduced the deferred tax asset at the acquisition date to reflect this limitation. The acquisition of Superior Bank was an asset acquisition and is not subject to the limitations of Section 382. As of December 31, 2017, the Company has federal net operating loss carryforwards of $41.1 million which will begin to expire in 2031. The Company has state net operating loss carryforwards of $27.9 million which will begin to expire in 2022. In addition, the Company has an AMT credit carryforward of $978,000 as of December 31, 2017, which has no expiration. The Company and its subsidiaries are subject to U.S. federal income tax as well as various state and local income taxes. The Company has concluded all U.S. federal income tax matters for years before 2014. With certain limited exceptions, the Company has concluded all state income tax matters for years before 2013. The Company applies the guidance in ASC 740-10, “Accounting for Uncertainty in Income Taxes.” ASC 740-10 provides guidance for how uncertain tax positions should be recognized, measured, presented, and disclosed in the financial statements. ASC 740-10 requires the evaluation of tax positions taken or expected to be taken in the course of preparing the Company’s tax returns to determine whether the tax positions are “more likely than not” to be sustained by the applicable tax authority based on technical merits of the position. Tax benefits from tax positions not deemed to meet the “more likely than not” threshold should not be recognized in the year of determination. A reconciliation of the beginning and ending amount of unrecognized income tax benefits is as follows (unrecognized state income tax benefits are not adjusted for the federal income tax impact): For the Year Ended December 31, (In thousands) 2017 2016 2015 Unrecognized income tax benefits, January 1 $ 944 $ — $ — Increases for tax positions related to: Prior years 9 422 — Current year 394 522 — Decreases for tax positions related to: Prior years (453 ) — — Current year — — — Settlement with taxing authorities — — — Expiration of applicable statutes of limitations — — — Unrecognized income tax benefits, December 31 $ 894 $ 944 $ — As of December 31, 2017 and 2016, the balance of unrecognized tax benefits, if recognized, that would reduce the effective tax rate is $581,100 and $614,000, respectively. The Company does not anticipate a significant change to the total amount of unrecognized tax benefits with the next 12 months. The Company classifies interest and penalties on uncertain tax positions as a component of noninterest expense. During the years ended December 31, 2017 and 2016, the Company recognized approximately ($4,000) and $90,000 in interest and penalties. The Company’s accrued interest and penalties on unrecognized tax benefits was $88,000 and $90,000 as of December 31, 2017 and 2016, respectively. Accrued interest and penalties are included in other liabilities.

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Common Share	Note 11—Earnings Per Common Share The following table displays a reconciliation of the information used in calculating basic and diluted net income per common share for each of the years in the period ended December 31, 2017. For the Years Ended December 31, (In thousands, except per share data) 2017 2016 2015 Net income $ 102,353 $ 65,774 $ 39,256 Weighted average common shares outstanding (Basic) 81,072,945 75,000,000 75,000,000 Weighted average restricted stock units 532,070 294,600 116,100 Weighted average common shares outstanding (Diluted) 81,605,015 75,294,600 75,116,100 Earnings per common share (Basic) $ 1.26 $ 0.88 $ 0.52 Earnings per common share (Diluted) $ 1.25 $ 0.87 $ 0.52 In March 2017, the Board of Directors approved a 75-for-one stock split of the Company’s common stock. The stock split occurred on April 7, 2017. The effect of the stock split on outstanding shares and earnings per share has been retroactively applied to all periods presented.

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2017
Compensation And Retirement Disclosure [Abstract]
Employee Benefits	Note 12—Employee Benefits Defined Benefit Pension Plan The Company accounts for its defined benefit pension plan in accordance with ASC Topic 715. This guidance requires companies to recognize the funded status of a defined benefit plan (measured as the difference between the fair value of plan assets and the projected benefit obligation) on the balance sheets and to recognize in other comprehensive income any gains or losses and prior service costs or benefits not included as components of periodic benefit cost. In accordance with purchase accounting rules, the plan’s prior unrecognized service cost and prior unrecognized loss were eliminated as of the acquisition date; thus, there are no prior service cost or loss amortization amounts reflected in the consolidated statements of income. Participation in the defined benefit pension plan was frozen effective April 30, 2011. The following table sets forth the defined benefit pension plan’s funded status as of December 31, 2017 and 2016 and amounts recognized in the Company’s consolidated financial statements for each of the years in the period ended December 31, 2017: (In thousands) 2017 2016 Change in benefit obligation: Benefit obligation at beginning of period $ 5,785 $ 6,176 Service cost 100 100 Interest cost 192 221 Actuarial loss 224 233 Administrative expenses paid (40 ) (59 ) Benefits paid (77 ) (79 ) Settlements (275 ) (807 ) Benefit obligation at end of year 5,909 5,785 Change in plan assets: Fair value of plan assets at beginning of period 4,689 4,464 Return on plan assets 533 240 Employer contributions 1,300 930 Administrative expenses paid (40 ) (59 ) Benefits paid (77 ) (79 ) Settlements (275 ) (807 ) Fair value of plan assets at end of year 6,130 4,689 Funded status $ 221 $ (1,096 ) (In thousands) 2017 2016 2015 Components of net periodic benefit cost: Service cost $ 100 $ 100 $ 100 Interest cost 192 221 232 Expected return on plan assets (261 ) (234 ) (278 ) Net loss amortization 65 53 61 Cost of settlements 45 156 155 Net periodic benefit cost $ 141 $ 296 $ 270 Amount recognized in accumulated other comprehensive income: Amortization of net actuarial loss $ 65 $ 53 $ 61 Net actuarial loss 48 (226 ) (35 ) Adjustment for settlement 45 156 155 Gains (losses) on pension liability 158 (17 ) 181 Tax effect (37 ) 4 (69 ) Net unrealized (losses) gains on pension liability $ 121 $ (13 ) $ 112 2017 2016 2015 Weighted average assumptions used to determine benefit obligations and net periodic pension cost at December 31: Discount rate 3.21 % 3.52 % 3.76 % Compensation increase rate N/A N/A N/A Census date 1/1/2018 1/1/2017 1/1/2016 Expected return on plan assets 5.50 % 5.50 % 5.50 % Of the above amount recognized in accumulated other comprehensive income, $44 thousand is expected to be recognized as a component of net periodic benefit cost in 2018. Retiree benefit payments, which reflect expected future service, are anticipated to be paid as follows: Amount Year (In thousands) 2018 $ 823 2019 514 2020 734 2021 1,019 2022 370 2023-2027 1,830 Total $ 5,290 In determining the expected return on plan assets, the Company considers the relative weighting of plan assets, the historical performance of total plan assets, individual asset classes, and economic and other indicators of future performance. In addition, the Company may consult with and consider the opinions of financial and other professionals in developing appropriate return benchmarks. The Company’s defined benefit pension plan fair values and weighted-average asset allocations at December 31, 2017 and 2016, by asset category, were as follows: 2017 2016 (In thousands) Fair Value of Plan Assets Asset Allocations Fair Value of Plan Assets Asset Allocations Asset Category: Equity securities $ 2,382 39 % $ 1,912 41 % Fixed income securities 3,342 55 2,594 55 Other securities — — 183 4 Cash and cash equivalents 406 6 — — Total $ 6,130 100 % $ 4,689 100 % The primary investment objective of the Company’s defined benefit pension plan is to maximize total return while accepting and managing a moderate to average degree of risk. The assets are invested based upon a moderate growth asset allocation model, which seeks to provide long-term growth of capital with a moderate level of current income and a somewhat higher level of principal volatility. For 2017, the assets were allocated in a target mix of 55% fixed income, 39% equity, and 6% other. The fixed income class is divided between a short-term government bond fund, a core fixed income bond fund and a high-yield bond fund. The equity class is diversified among large, mid and small cap growth and value stock funds with an emphasis being placed on large cap. There is also an exposure in the international equity market. This diversification among all of the equity sectors is an effort to reduce risk and attempt to generate higher returns. As a result of market conditions, the target percentages may not be achieved at any one point in time. The investments are managed by the Trust Division of the Company within the established guidelines. It is the intent of management to give the investment managers flexibility within the overall parameters designated in the investment model selected by the Bank’s Trust Company Investment Committee for the plan. The fair values of all plan assets as of December 31, 2017 and 2016, were measured using quoted prices in active markets for identical assets and liabilities (Level 1 inputs, as defined by ASC Topic 820, “Fair Value Measurements and Disclosures”). The Company does not have a minimum cash contribution for 2018. The Company contributed $1.3 million and $0.9 million for the years ended December 31, 2017 and 2016, respectively. The Company did not make a contribution in 2015. Other Plans Contributions to the 401(k) plan totaled $3.5 million and $3.4 million in 2017 and 2016, respectively. The accrued liability for the supplemental retirement plan that originated from an acquired bank, accounted for under ASC Topic 715, approximates the projected benefit obligation. The accrued liability for this plan was $1.9 million at December 31, 2017 and 2016 and the amount recognized in compensation expense for the years ended December 31, 2017, 2016 and 2015 was $706 thousand, $322 thousand and $104 thousand, respectively. The accrued liabilities for the unqualified supplemental retirement and voluntary deferred compensation plans were $3.2 million at December 31, 2017 and 2016. The amounts recognized in compensation expense for the years ended December 31, 2017, 2016, and 2015 were $47 thousand, $186 thousand and $102 thousand, respectively. Compensation expense for the voluntary deferred compensation plan is impacted by the changes in market values of plan assets. Projected benefit payments under these plans are anticipated to be paid as follows: Year Amount (In thousands) 2018 $ 171 2019 375 2020 376 2021 384 2022 451 2023-2027 2,299 Total $ 4,056

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Note 13—Related Party Transactions In the normal course of business, loans are made to directors and executive officers and to companies in which they have a significant ownership interest. In the opinion of management, these loans are made on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with other parties, are consistent with sound banking practices, and are within applicable regulatory and lending limitations. The aggregate balances of related party loans and deposits as of December 31, 2017 and 2016 were insignificant.

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2017
Banking And Thrift [Abstract]
Regulatory Matters	Note 14—Regulatory Matters The Bank is subject to the capital adequacy requirements of the OCC. The Company, as a bank holding company, is subject to the capital adequacy requirements of the Federal Reserve. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company’s consolidated financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company and the Bank must meet specific capital guidelines that involve quantitative measures of assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. Capital amounts and classifications are also subject to qualitative judgment by regulators about components, risk weightings, and other related factors. The risk-based capital requirements of the Federal Reserve and the OCC define capital and establish minimum capital requirements in relation to assets and off-balance sheet exposure, adjusted for credit risk. The risk-based capital standards currently in effect are designed to make regulatory capital requirements sensitive to differences in risk profiles among bank holding companies and banks, to account for off-balance sheet exposure and to minimize disincentives for holding liquid assets. Assets and off-balance sheet items are assigned to broad risk categories, each with appropriate relative risk weights. The resulting capital ratios represent capital as a percentage of total risk-weighted assets and off-balance sheet items. The Federal Reserve, the FDIC and the OCC have issued guidelines governing the levels of capital that banks must maintain. The bank guidelines for the period as of December 31, 2017 specify capital tiers, which include the following classifications: Capital Tiers Tier 1 Capital to Average Assets (Leverage) Common Risk - Weighted Assets (CET1) Tier 1 Capital to Risk – Weighted Assets Total Capital to Risk – Weighted Assets Well capitalized 5% or above 6.5% or above 8% or above 10% or above Adequately capitalized 4% or above 4.5% or above 6% or above 8% or above Undercapitalized Less than 4% Less than 4.5% Less than 6% Less than 8% Significantly undercapitalized Less than 3% Less than 3% Less than 4% Less than 6% Critically undercapitalized Tangible Equity / Total Assets less than 2% The most recent notification from the OCC categorized the Bank as well-capitalized under the regulatory framework. The actual capital amounts and ratios for the Company and the bank as of December 31, 2017 and 2016 are presented in the following table and as shown, are above the thresholds necessary to be considered “well-capitalized”. Management believes there are no conditions or events that would change that classification in the foreseeable future. Consolidated Company Bank (In thousands) Amount Ratio Amount Ratio December 31, 2017 Tier 1 leverage $ 1,096,438 10.7 % $ 1,198,234 11.7 % Common equity tier 1 capital (transitional) 1,058,888 10.6 1,149,181 11.5 Tier 1 risk-based capital 1,096,438 10.9 1,198,234 12.0 Total risk-based capital 1,283,561 12.8 1,311,376 13.1 The minimum amounts of capital and ratios established by banking regulators are as follows: Tier 1 leverage $ 410,770 4.0 % $ 410,743 4.0 % Common equity tier 1 capital (transitional) 450,951 4.5 450,874 4.5 Tier 1 risk-based capital 601,269 6.0 601,165 6.0 Total risk-based capital 801,691 8.0 801,553 8.0 Well capitalized requirement: Tier 1 leverage N/A N/A $ 513,429 5.0 % Common equity tier 1 capital (transitional) N/A N/A 651,262 6.5 Tier 1 risk-based capital N/A N/A 801,553 8.0 Total risk-based capital N/A N/A 1,001,941 10.0 Consolidated Company Bank (In thousands) Amount Amount Amount Ratio December 31, 2016 Tier 1 leverage $ 824,676 8.9 % $ 1,035,972 11.2 % Common equity tier 1 (CET1) 793,268 8.8 989,990 11.0 Tier 1 risk-based capital 824,676 9.2 1,035,972 11.5 Total risk-based capital 1,007,011 11.2 1,144,519 12.8 The minimum amounts of capital and ratios established by banking regulators are as follows: Tier 1 leverage $ 371,052 4.0 % $ 370,836 4.0 % Common equity tier 1 (CET1) 403,718 4.5 403,578 4.5 Tier 1 risk-based capital 538,290 6.0 538,105 6.0 Total risk-based capital 717,720 8.0 717,473 8.0 Well capitalized requirement: Tier 1 leverage N/A N/A $ 463,546 5.0 % Common equity tier 1 (CET1) N/A N/A 583,248 6.5 Tier 1 risk-based capital N/A N/A 717,844 8.0 Total risk-based capital N/A N/A 897,305 10.0 Under regulations controlling national banks, the payment of any dividends by a bank without prior approval of the OCC is limited to the current year’s net profits (as defined by the OCC) and retained net profits of the two preceding years. The Federal Reserve, as primary regulator for bank holding companies, has also stated that all common stock dividends should be paid out of current income. As the Company does not generate income on a stand-alone basis, it does not have the capability to pay common stock dividends without receiving dividends from the Bank. The Bank is required to maintain average reserve balances in the form of cash or deposits with the Federal Reserve Bank. The reserve balance varies depending upon the types and amounts of deposits. At December 31, 2017 and 2016, the required reserve balance with the Federal Reserve Bank was approximately $70.9 million and $38.3 million, respectively.

Commitments and Contingent Liab

Commitments and Contingent Liabilities	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	Note 15—Commitments and Contingent Liabilities The consolidated financial statements do not reflect various commitments and contingent liabilities which arise in the normal course of banking business and which involve elements of credit risk, interest rate risk, and liquidity risk. The commitments and contingent liabilities are commitments to extend credit, home equity lines, overdraft protection lines, and standby letters of credit. Such financial instruments are recorded when they are funded. A summary of commitments and contingent liabilities at December 31, 2017 is as follows: As of December 31, (In thousands) 2017 2016 Commitments to extend credit $ 3,270,097 $ 2,643,501 Standby letters of credit 101,718 120,532 Performance letters of credit 17,638 29,270 Commercial letters of credit 11,790 — Commitments to extend credit and letters of credit include some exposure to credit loss in the event of nonperformance of the customer. 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. In addition, the Company has entered certain contingent commitments to grant loans totaling $523.0 million as of December 31, 2017. Standby letters of credit are conditional commitments issued to guarantee the performance of a customer to a third party. The credit policies and procedures for such commitments are the same as those used for lending activities. Because these instruments have fixed maturity dates and because a number expire without being drawn upon, they generally do not present any significant liquidity risk. No significant losses on commitments were incurred during the years ended December 31, 2017 and 2016. The Company makes investments in limited partnerships, including certain low income housing partnerships for which tax credits are received. As of December 31, 2017 and 2016, unfunded capital commitments totaled $20.3 million and $15.1 million, respectively. The Company and the Bank are defendants in various pending and threatened legal actions arising in the normal course of business. In the opinion of management, based upon the advice of legal counsel, the ultimate disposition of all pending and threatened legal action will not have a material effect on the Company’s consolidated financial statements.

Concentrations of Credit

Concentrations of Credit	12 Months Ended
	Dec. 31, 2017
Risks And Uncertainties [Abstract]
Concentrations of Credit	Note 16—Concentrations of Credit Most of the loans, commitments and letters of credit involve customers or sponsors in the Company’s market areas. Investments in state and municipal securities also involve governmental entities within the Company’s market areas. General concentrations of credit by type of loan are set forth in Note 3 of these consolidated financial statements. The distribution of commitments to extend credit approximates the distribution of loans outstanding. Letters of credit were granted primarily to commercial borrowers.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2017
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Note 17—Supplemental Cash Flow Information For the Years Ended December 31, (In thousands) 2017 2016 2015 Cash paid during the year for: Interest $ 69,289 $ 55,086 $ 44,333 Income taxes, net of refunds 33,268 23,025 22,139 Non-cash investing activities (at fair value): Transfers of loans to other real estate $ 7,023 $ 13,494 $ 11,800 Transfers of commercial loans to loans held for sale 16,206 318,868 19,400 Transfers of loans to other assets (net profits interest) — 19,104 —

Disclosure About Fair Values of

Disclosure About Fair Values of Financial Instruments	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Disclosure About Fair Values of Financial Instruments	Note 18—Disclosure About Fair Values of Financial Instruments The Company groups its assets and liabilities measured at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. This hierarchy requires the Company to maximize the use of observable market data, when available, and to minimize the use of unobservable inputs when determining fair value. Each fair value measurement is placed into the proper level based on the lowest level of significant input. These levels are: • Level 1 —Valuation is based upon quoted prices for identical instruments traded in active markets. • Level 2 —Valuation is based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market. • Level 3 —Valuation is generated from model-based techniques that use significant assumptions not observable in the market. These unobservable assumptions reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. Valuation techniques include use of option pricing models, discounted cash flow models, and similar techniques. Transfers between fair value levels are recognized at the end of the fiscal quarter in which the associated change in inputs occurs. Assets and Liabilities Recorded at Fair Value on a Recurring Basis The table below presents the Company’s assets and liabilities measured at fair value on a recurring basis categorized by the level of inputs used in the valuation of each asset at December 31, 2017 and 2016: (In thousands) Carrying Value (Level 1) (Level 2) (Level 3) December 31, 2017 Investment securities available-for-sale: U.S. Treasury securities $ 96,844 $ — $ 96,844 $ — Obligations of U.S. government agencies 81,224 — 81,224 — Mortgage-backed securities issued or guaranteed by U.S. agencies (MBS) Residential pass-through: Guaranteed by GNMA 106,027 — 106,027 — Issued by FNMA and FHLMC 430,422 — 430,422 — Other residential mortgage-backed securities 46,392 — 46,392 — Commercial mortgage-backed securities 72,195 — 72,195 — Total MBS 655,036 — 655,036 — Obligations of states and municipal subdivisions 423,959 — 423,959 Other securities 5,885 5,885 — — Total investment securities available-for-sale 1,262,948 5,885 1,257,063 — Derivative assets 3,985 — 3,985 — Other assets (Net profits interests) 15,833 — — 15,833 Total recurring basis measured assets $ 1,282,766 $ 5,885 $ 1,261,048 $ 15,833 Derivative liabilities $ 25,307 $ — $ 25,307 $ — Total recurring basis measured liabilities $ 25,307 $ — $ 25,307 $ — (In thousands) Carrying Value (Level 1) (Level 2) (Level 3) December 31, 2016 Investment securities available-for-sale: U.S. Treasury securities $ 96,785 $ — $ 96,785 $ — Obligations of U.S. government agencies 97,528 — 97,528 — Mortgage-backed securities issued or guaranteed by U.S. agencies (MBS) Residential pass-through: Guaranteed by GNMA 153,153 — 153,153 — Issued by FNMA and FHLMC 265,328 — 265,328 — Other residential mortgage-backed securities 47,561 — 47,561 — Commercial mortgage-backed securities 62,613 — 62,613 — Total MBS 528,655 — 528,655 — Obligations of states and municipal subdivisions 410,812 — 410,812 — Other securities 5,567 5,567 — — Total investment securities available-for-sale 1,139,347 5,567 1,133,780 — Derivative assets 4,361 — 4,361 — Other assets (Net profits interest) 19,425 — — 19,425 Total recurring basis measured assets $ 1,163,133 $ 5,567 $ 1,138,141 $ 19,425 Derivative liabilities $ 20,360 $ — $ 20,360 $ — Total recurring basis measured liabilities $ 20,360 $ — $ 20,360 $ — There were no transfers between the Level 1 and Level 2 fair value categories during each the three years in the period ended December 31, 2017. Changes in Level 3 Fair Value Measurements The table below includes a roll-forward of the consolidated balance sheet amounts for each of the years in the period ended December 31, 2017 Level 3 Assets Measured at Fair Value on a Recurring Basis Other Assets - Net Profits Interests For the Years Ended December 31, (In thousands) 2017 2016 2015 Beginning Balance $ 19,425 $ — $ — Addition of net profits interest to other assets — 19,104 — Total net gains (losses) included in earnings (2,442 ) 407 — Distributions received (1,150 ) (86 ) — Balance at December 31 $ 15,833 $ 19,425 $ — Net unrealized (losses) gains included in earnings relating to assets held at the end of the period $ (2,442 ) $ 407 $ — The fair value of the net profit interests in oil and gas reserves was estimated using discounted cash flow analyses applied to the expected cash flows from producing developed wells. Expected cash flows are derived from reports prepared by consulting engineers under established professional standards for the industry. These expected cash flow projections contain significant unobservable inputs regarding the net recoverable oil and gas reserves and forward-looking commodity prices discounted at a rate of 10%. Therefore, the fair value is subject to change based on these commodity markets. An increase of 5% in the discount rate will not produce a material change in the fair value of the net profits interest. Assets Recorded at Fair Value on a Nonrecurring Basis From time to time, the Company may be required to measure certain other financial assets at fair value on a nonrecurring basis in accordance with GAAP. These adjustments to fair value usually result from the application of lower of cost or fair value accounting or write-downs of individual assets. For assets measured at fair value on a nonrecurring basis which were still held on the balance sheets at December 31, 2017 and 2016, the following tables provide the level of valuation assumptions used to determine each adjustment and the related carrying value: (In thousands) Carrying Value (Level 1) (Level 2) (Level 3) December 31, 2017 Loans held for sale $ 61,359 $ — $ 61,359 $ — Impaired loans, net of specific allowance 65,087 — — 65,087 Other real estate 7,605 — — 7,605 Total assets measured on a nonrecurring basis $ 134,051 $ — $ 61,359 $ 72,692 (In thousands) Carrying Value (Level 1) (Level 2) (Level 3) December 31, 2016 Loans held for sale $ 17,822 $ — $ 17,822 $ — Impaired loans, net of specific allowance 151,720 — — 151,720 Other real estate 18,875 — — 18,875 Total assets measured on a nonrecurring basis $ 188,417 $ — $ 17,822 $ 170,595 The fair value of collateral-dependent impaired loans and OREO and the related fair value adjustments are generally based on unadjusted third-party appraisals. Appraisals that are not based on observable inputs or that require significant adjustments or fair value measurements that are not based on third-party appraisals are considered to be based on significant unobservable inputs. Nonrecurring fair value measurements of collateral dependent loans secured by oil and gas reserves and mineral rights are generally based on borrower provided or third-party reserve reports (which are reviewed by the Company’s engineering team) that utilize projected cash flows under current market conditions and include significant unobservable inputs. Projected cash flows are discounted according to risk characteristics of the underlying oil and gas properties. Assets are evaluated to demonstrate with reasonable certainty that crude oil, natural gas and natural gas liquids can be recovered from known oil and gas reservoirs under existing economic and operating conditions at current prices with existing conventional equipment, operating methods and costs. The significant unobservable inputs used in these valuations have been developed through our contacts with oil and gas industry participants, asset management and workout professionals and approved by senior management. Significant unobservable inputs used in Level 3 fair value measurements for financial assets measured at fair value on a nonrecurring basis at December 31, 2017 and 2016 are summarized below: Quantitative Information about Level 3 Fair Value Measurements (In thousands) Carrying Value Valuation Methods Unobservable Inputs Range December 31, 2017 Impaired loans, net of specific allowance $ 65,087 Appraised value, as adjusted Discount to fair value 0% - 50% Discounted cash flow Net recoverable oil and gas reserves and forward-looking commodity prices. Discount rate - 9% 0% - 29% (1) Discounted cash flow Discount rates - 3.6% to 8.0% 0% - 1% (1) Estimated closing costs 10% Other real estate 7,605 Appraised value, as adjusted Discount to fair value 0% - 20% Estimated closing costs 10% (1) - Represents fair value as a percent of the unpaid principal balance. Quantitative Information about Level 3 Fair Value Measurements (In thousands) Carrying Value Valuation Methods Unobservable Inputs Range December 31, 2016 Impaired loans, net of specific allowance $ 151,720 Appraised value, as adjusted Discount to fair value 0%-50% Discounted cash flow Net recoverable oil and gas reserves and forward-looking commodity prices. Discount rate - 9% 0% - 4% (1) Discounted cash flow Discount rates - 3.8% to 12.5% 0% - 1% (1) Estimated closing costs 10% Other real estate 18,875 Third-Party Appraisals Discount of fair value 0%-20% Estimated closing costs 10% (1) - Represents fair value as a percent of the unpaid principal balance. Determination of Fair Values In accordance with ASC 820-10-35, fair values are based on the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The following describes the assumptions and methodologies used to estimate the fair value of financial instruments recorded at fair value in the consolidated balance sheets and for estimating the fair value of financial instruments for which fair value is disclosed under ASC 825-10-50. Investment Securities . When quoted prices are available in an active market, securities are classified as Level 1. For securities reported at fair value utilizing Level 2 inputs, the Company obtains fair value measurements from an independent pricing service. These fair value measurements consider observable market data that may include benchmark yield curves, reported trades, broker/dealer quotes, issuer spreads and credit information, among other inputs. Loans Held for Sale . Loans held for sale are recorded at the lower of aggregate cost or fair value. Fair value is generally based on quoted market prices of similar loans and is considered to be Level 2. Net Loans . Fair values of loans are estimated using discounted cash flow analyses using various discount spreads to Treasury yields that approximate interest rates currently being offered for loans with similar terms to borrowers of similar credit quality. Derivative Financial Instruments . Derivative financial instruments are measured at fair value based on modeling that utilizes observable market inputs for various interest rates published by leading third-party financial news and data providers. This is observable data that represents the rates used by market participants for instruments entered into at that date; however, they are not based on actual transactions so they are classified as Level 2. Other Assets - Net profits interests. The fair value of the net profit interests in oil and gas reserves was estimated using discounted cash flow analyses applied to the expected cash flows from producing developed wells. Expected cash flows are derived from reports prepared by consulting engineers under established professional standards for the industry. Deposits . The fair values disclosed for demand deposits are, by definition, equal to the amount payable on demand at the reporting date (that is, their carrying amounts). Fair values for CDs are estimated using a discounted cash flow calculation that applies interest rate spreads to current Treasury yields. FHLB . The fair value of the FHLB advance approximates its book value considering their short-term maturities. Security Sold Under Agreements to Repurchase . The carrying amount of security repurchase agreements approximates their fair values. Senior Debt . The fair value of senior debt was estimated by obtaining broker indications that compared the Company’s senior debt to other comparable financial institutions. Subordinated Debt. The fair value of subordinated debentures was estimated by obtaining broker indications that compared the Company’s subordinated debentures to other comparable financial institutions. Junior Subordinated Debentures. The fair value of junior subordinated debentures was estimated by obtaining broker indications that compared the Company’s junior subordinated debentures to other comparable financial institutions. Limitations . The following fair value estimates are determined as of a specific point in time utilizing various assumptions and estimates. The use of assumptions and various valuation techniques, as well as the absence of secondary markets for certain financial instruments, will likely reduce the comparability of fair value disclosures between financial institutions. The fair values for loans involve the use of significant internally-developed pricing assumptions due to market-illiquidity for loans net of unearned income and loans held for sale as of December 31, 2017 and 2016. These assumptions are considered to reflect inputs that market participants would use in transactions involving these instruments as of the measurement date. This table only includes financial instruments of the Company, and, accordingly, the total of the fair value amounts does not represent, and should not be construed to represent, the underlying value of the Company. The estimated fair values of the Company’s financial instruments are as follows: As of December 31, 2017 Carrying (In thousands) Amount Fair Value Level 1 Level 2 Level 3 Financial Assets: Cash and due from banks $ 238,707 $ 238,707 $ 238,707 $ — $ — Interest-bearing deposits in other banks 482,568 482,568 482,568 — — Federal funds sold 9,536 9,536 9,536 — — Securities available-for-sale 1,262,948 1,262,948 5,885 1,257,063 — Securities held-to-maturity 290 311 — 311 — Loans held for sale 61,359 61,359 — 61,359 — Net loans 8,165,851 8,134,903 — — 8,134,903 Derivative assets 3,985 3,985 — 3,985 — Other assets-net profits interests 15,833 15,833 — — 15,833 Financial Liabilities: Deposits 9,011,515 9,006,890 — 9,006,890 — Advances from FHLB 150,000 150,000 — 150,000 — Securities sold under agreements to repurchase 1,026 1,026 — 1,026 — Senior debt 184,629 194,484 — 194,484 — Subordinated debt 98,687 94,724 — 94,724 — Junior subordinated debentures 36,472 49,161 — 49,161 — Derivative liabilities 25,307 25,307 — 25,307 — As of December 31, 2016 (In thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial Assets: Cash and due from banks $ 48,017 $ 48,017 $ 48,017 $ — $ — Interest-bearing deposits in other banks 199,747 199,747 199,747 — — Federal funds sold 1,161 1,161 1,161 — — Securities available-for-sale 1,139,347 1,139,347 5,567 1,133,780 — Securities held-to-maturity 425 463 — 463 — Loans held for sale 17,822 17,822 — 17,822 — Net loans 7,350,443 7,395,003 — — 7,395,003 Derivative assets 4,361 4,361 — 4,361 — Other assets-net profits interests 19,425 19,818 — — 19,818 Financial Liabilities: Deposits 8,016,749 7,904,926 — 7,904,926 — Securities sold under agreements to repurchase 3,494 3,494 — 3,494 — Senior debt 193,788 191,076 — 191,076 — Subordinated debt 98,441 97,938 — 97,938 — Junior subordinated debentures 35,989 47,409 — 47,409 — Derivative liabilities 20,360 20,360 — 20,360 —

Variable Interest Entities and

Variable Interest Entities and Other Investments	12 Months Ended
	Dec. 31, 2017
Variable Interest Entities And Other Investments [Abstract]
Variable Interest Entities and Other Investments	Note 19—Variable Interest Entities and Other Investments Under ASC 810-10-65, the Company is deemed to be the primary beneficiary and required to consolidate a variable interest entity (“VIE”) if it has a variable interest in the VIE that provides it with a controlling financial interest. For such purposes, the determination of whether a controlling financial interest exists is based on whether a single party has both the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and the obligation to absorb the losses of the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. ASC 810-10-65, as amended, requires continual reconsideration of conclusions reached regarding which interest holder is a VIE’s primary beneficiary. The Bank has invested in several affordable housing projects as a limited partner. The partnerships have qualified to receive annual affordable housing federal tax credits that are recognized as a reduction of current tax expense. The Company has determined that these structures meet the definition of VIE’s under Topic ASC 810 but that consolidation is not required, as the Bank is not the primary beneficiary. At December 31, 2017 and 2016, the Bank’s maximum exposure to loss associated with these limited partnerships was limited to the Bank’s investment. The Company accounts for these investments and the related tax credits using either the effective yield method or the proportional amortization method, depending upon the date of the investment. Under the effective yield method, the Bank recognizes the tax credits as they are allocated and amortizes the initial costs of the investments to provide a constant effective yield over the period that the tax credits are allocated. Under the proportional amortization method, the Bank amortizes the cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as a component of income tax expense. At December 31, 2017 and 2016, the Company had recorded investments in other assets on its consolidated balance sheets of approximately $7.9 million and $4.2 million, respectively related to these investments. Additionally, the Company invests in other certain limited partnerships accounted for under the cost method totaling $14.0 million and $6.1 million as of December 31, 2017 and 2016, respectively and the equity method totaling $8.8 million and $3.9 million as of December 31, 2017 and 2016, respectively. During 2016, the Bank received net profits interests in oil and gas reserves, in connection with the reorganization under bankruptcy of two loan customers. The Company has determined that these contracts meet the definition of VIE’s under Topic ASC 810, but that consolidation is not required as the Bank is not the primary beneficiary. The net profits interests are financial instruments and recorded at estimated fair value, which was $15.8 million and $19.4 million at December 31, 2017 and 2016, respectively, representing the maximum exposure to loss as of that date. The Company has established a rabbi trust related to the deferred compensation plan offered to certain of its employees. The Company contributes employee cash compensation deferrals to the trust. The assets of the trust are available to creditors of the Company only in the event the Company becomes insolvent. This trust is considered a VIE because either there is no equity at risk in the trust or because the Company provided the equity interest to its employees in exchange for services rendered. The Company is considered the primary beneficiary of the rabbi trust as it has the ability to select the underlying investments made by the trust, the activities that most significantly impact the economic performance of the rabbi trust. The Company includes the assets of the rabbi trust as a component of other assets and a corresponding liability for the associated benefit obligation in other liabilities in its consolidated balance sheets. At December 31, 2017 and 2016, the amount of rabbi trust assets and benefit obligation was $3.6 million and $3.0 million, respectively.

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Reporting	Note 20—Segment Reporting The Company determines reportable segments based on the services offered, the significance of the services offered, the significance of those services to the Company’s financial condition and operating results and management’s regular review of the operating results of those services. The Company operates through three operating segments: Banking, Financial Services and Corporate. The Banking Segment includes the Commercial Banking, Retail Banking and Private Banking lines of business. The Commercial Banking line of business includes a general business services component primarily focusing on commercial & industrial (C&I), community banking, business banking and commercial real estate lending to clients in the geographic footprint in Texas and the southeast United States. In addition, the Commercial Banking line of business includes within C&I a separate component that focuses on select industries (which is referred to as the “specialized industries”) in which the Company believes it has specialized experience and service capabilities, including energy, healthcare, restaurant industry, and technology. The Company serve clients in these specialized industries both within the geographic footprint and throughout the United States as a result of the national orientation of many of these businesses. The Retail Banking line of business offers a broad range of retail banking services including mortgage services through the branch network to serve the needs of consumer and small businesses in the geographic footprint. The Private Banking line of business offers banking services and loan products tailored to the needs of the high-net worth clients in the geographic footprint. The Financial Services Segment includes the Trust, Retail Brokerage, Investment Services and Insurance businesses. These businesses offer products independently to their own customers as well as to Banking Segment clients. Investment Services operates through the “Linscomb & Williams” name and Insurance operates though the “Cadence Insurance” name. The products offered by the businesses in the Financial Services Segment primarily generate non-banking service fee income. The Corporate Segment reflects parent-only activities and intercompany eliminations. Business segment results are determined based upon the management reporting system, which assigns balance sheet and income statement items to each of the business segments. The process is designed around the organizational and management structure and, accordingly, the results derived are not necessarily comparable with similar information published by other financial institutions or in accordance with generally accepted accounting principles. The Company evaluates performance and allocates resources based on profit or loss from operations. There are no material inter-segment sales or transfers. The accounting policies used by each reportable segment are the same as those discussed in Note 1. All costs, except corporate administration and income taxes, have been allocated to the reportable segments. Therefore, combined amounts agree to the consolidated totals. The following tables present the operating results of the segments as of and for the years ended December 31, 2017, 2016 and 2015: For the Year Ended December 31, 2017 (In thousands) Banking Financial Services Corporate Consolidated Net interest income $ 344,987 $ (1,347 ) $ (17,424 ) $ 326,216 Provision for credit losses 9,735 — — 9,735 Noninterest income 51,286 47,956 632 99,874 Noninterest expense 194,212 36,178 2,966 233,356 Income tax expense (benefit) 88,417 2,000 (9,771 ) 80,646 Net income (loss) $ 103,909 $ 8,431 $ (9,987 ) $ 102,353 Total assets $ 10,854,206 $ 90,639 $ 4,081 $ 10,948,926 For the Year Ended December 31, 2016 (In thousands) Banking Financial Services Corporate Consolidated Net interest income $ 297,701 $ (201 ) $ (18,061 ) $ 279,439 Provision for credit losses 49,348 — — 49,348 Noninterest income 45,499 42,727 177 88,403 Noninterest expense 186,874 32,334 972 220,180 Income tax expense (benefit) 37,442 3,567 (8,469 ) 32,540 Net income (loss) $ 69,536 $ 6,625 $ (10,387 ) $ 65,774 Total assets $ 9,439,504 $ 84,003 $ 7,381 $ 9,530,888 For the Year Ended December 31, 2015 (In thousands) Banking Financial Services Corporate Consolidated Net interest income $ 265,450 $ (36 ) $ (17,636 ) $ 247,778 Provision for credit losses 35,984 — — 35,984 Noninterest income 38,697 40,964 242 79,903 Noninterest expense 200,544 31,393 395 232,332 Income tax expense (benefit) 23,673 3,337 (6,901 ) 20,109 Net income (loss) $ 43,946 $ 6,198 $ (10,888 ) $ 39,256

Equity-based Compensation

Equity-based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity-based Compensation	Note 21—Equity-based Compensation The Company administers a long-term incentive compensation plan that permits the granting of incentive awards in the form of stock options, restricted stock, restricted stock units, performance units, stock appreciation rights, or other stock-based awards. The terms of all awards issued under these plans are determined by the Compensation Committee of the Board of Directors The Amended and Restated 2015 Omnibus Incentive Plan (the “Plan”), permits the Company to grant to employees and directors various forms of incentive compensation. The principal purposes of this plan are to focus directors, officers and other employees and consultants on business performance that creates shareholder value, to encourage innovative approaches to the business of the Company, and to encourage ownership of the Company’s stock. The Plan authorizes 7,500,000 common share equivalents available for grant, where grants of full value awards (e.g., shares of restricted stock, restricted stock units and performance stock units) count as one share equivalent. The number of remaining share equivalents available for future issuance under the Plan was 6,827,250 at December 31, 2017. On July 21, 2015, the Company granted 258,375 restricted stock units to select executives. These grants contained performance conditions which, for accounting purposes, were deemed improbable of being achieved during the fourth quarter of 2016. On November 30, 2016, these grants were cancelled and replaced with 395,250 restricted stock units with a market condition. Also granted at the time of the modification were 277,500 restricted stock units to new grantees. The grantees do not have rights as stockholders, including the right to dividends, until the restricted stock units are vested. The fair value of these restricted stock units was estimated based upon the possible future value of the Company’s common stock using a Monte-Carlo simulation, which included the following assumptions as of the grant date: Fair value of common stock (non-marketable, per share) $ 14.83 Time to settlement date 2.08 years Volatility 30.0 % Risk-free rate 1.1 % While the grant specifies a stated target number of units, the determination of the actual settlement in shares will be based on the achievement of a market condition related to the Company’s share value as of December 31, 2018. The actual units vested can be in the range of zero to 1.75 times the units granted based on a share value ranging from $21.76 to $27.55. The Company recorded $1.7 million equity-based compensation expense for the outstanding restricted stock units for the year ended December 31, 2017, compared to $117 thousand and $631 thousand for the same periods in 2016 and 2015, respectively. The remaining expense related to unvested restricted stock units is $1.8 million as of December 31, 2017 and will be recognized over the next 14 months. There were 672,750 outstanding non-vested restricted stock units with a grant date fair value of $5.14. There were no grants or forfeitures for the year ended December 31, 2017. The following table summarizes the activity related to restricted stock unit awards for the years ended December 31, 2017, 2016 and 2015: For the Year Ended December 31, 2017 2016 2015 Number of Shares Fair Value per Unit at Award Date Number of Shares Fair Value per Unit at Award Date Number of Shares Fair Value per Unit at Award Date Non-vested at beginning of period 672,750 $ 5.14 258,375 $ 13.43 — $ — Units deemed improbable to vest — — (258,375 ) 13.43 — — Amended grants — — 395,250 5.14 — — New units — — 277,500 5.14 258,375 13.43 Non-vested at end of period 672,750 $ 5.14 672,750 $ 5.14 258,375 $ 13.43

Condensed Financial Information

Condensed Financial Information of Cadence Bancorporation (Parent Only)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Condensed Financial Information of Cadence Bancorporation (Parent Only)	Note 22—Condensed Financial Information of Cadence Bancorporation (Parent Only) Condensed Balance Sheets December 31, 2017 and 2016 (In thousands) 2017 2016 ASSETS Cash and due from banks $ 494 $ — Interest-bearing deposits with banks 150,587 50,330 Investment in consolidated bank subsidiary 1,488,223 1,315,336 Investment in consolidated nonbank subsidiaries 16,008 14,881 Other assets 3,587 7,381 Total Assets $ 1,658,899 $ 1,387,928 LIABILITIES AND SHAREHOLDER’S EQUITY Liabilities: Interest payable $ 813 $ 810 Senior debt 184,629 193,788 Subordinated debt 73,982 73,788 Junior subordinated debentures 36,472 35,989 Other liabilities 3,947 3,055 Total liabilities 299,843 307,430 Shareholder’s Equity: Common Stock 836 750 Additional Paid-in Capital 1,037,040 879,665 Retained earnings 340,213 232,614 Accumulated other comprehensive loss (“OCI”) (19,033 ) (32,531 ) Total Shareholder’s Equity 1,359,056 1,080,498 Total Liabilities and Shareholder’s Equity $ 1,658,899 $ 1,387,928 Condensed Statements of Income For the Years Ended December 31, 2017, 2016 and 2015 (In thousands) 2017 2016 2015 INCOME Dividends from bank subsidiary $ 11,000 $ 13,500 $ 8,500 Dividends from nonbank subsidiary — — 500 Interest income 65 25 21 Other income 632 176 22 Total income 11,697 13,701 9,043 EXPENSES Interest expense 17,424 18,060 17,635 Other expenses 3,305 2,092 271 Total expenses 20,729 20,152 17,906 Loss before income taxes and equity in undistributed income of subsidiaries (9,032 ) (6,451 ) (8,863 ) Equity in undistributed income of subsidiaries 103,390 64,424 41,132 Net income before income taxes 94,358 57,973 32,269 Income tax benefit (7,995 ) (7,801 ) (6,987 ) Net income $ 102,353 $ 65,774 $ 39,256 Condensed Statements of Cash Flows For the Years Ended December 31, 2017, 2016 and 2015 (In thousands) 2017 2016 2015 CASH FLOWS FROM OPERATING ACTIVITIES Net income $ 102,353 $ 65,774 $ 39,256 Adjustments to reconcile net income to net cash provided (used) in operations: Deferred income taxes 1,084 (1,598 ) (531 ) Equity in undistributed income of subsidiaries (103,390 ) (64,424 ) (41,132 ) Decrease in other assets 3,892 3,043 2,539 Increase (decrease) in interest payable 3 (102 ) 804 Increase (decrease) in other liabilities 891 (504 ) (747 ) Net cash provided by operating activities 4,833 2,189 189 CASH FLOWS FROM INVESTING ACTIVITIES Capital contributions to Bank subsidiary (50,000 ) — (20,000 ) (Increase) decrease in limited partnership investments (63 ) 463 (157 ) Net cash (used in) provided by investing activities (50,063 ) 463 (20,157 ) CASH FLOWS FROM FINANCING ACTIVITIES Issuance of subordinated debt, net of debt issuance costs — — 39,253 Issuance of senior debt, net of debt issuance costs — — 9,813 Purchase of senior debt (9,600 ) (78 ) — Proceeds from issuance of common stock 155,581 — — Net cash provided by (used in) financing activities 145,981 (78 ) 49,066 Net increase in cash and cash equivalents 100,751 2,574 29,098 Cash and cash equivalents at beginning of year 50,330 47,756 18,658 Cash and cash equivalents at end of year $ 151,081 $ 50,330 $ 47,756

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Note 23—Accumulated Other Comprehensive Income (Loss) Activity within the balances in accumulated other comprehensive income (loss) is shown in the following tables for each of the years in the period ended December 31, 2017. (In thousands) Unrealized gains (losses) on securities available for sale Unrealized gains (losses) on defined benefit pension plans Unrealized gains (losses) on derivative instruments designated as cash flow hedges Accumulated other comprehensive gain (loss) Balance, December 31, 2014 $ 8,664 $ (599 ) $ — $ 8,065 Net change (2,763 ) 112 1,626 (1,025 ) Balance, December 31, 2015 5,901 (487 ) 1,626 7,040 Net change (27,720 ) (13 ) (11,838 ) (39,571 ) Balance, December 31, 2016 (21,819 ) (500 ) (10,212 ) (32,531 ) Period change 21,605 121 (2,982 ) 18,744 Reclassification of amounts within AOCI to retained earnings due to tax reform (See Notes 1 and 10) (1,946 ) (152 ) (3,148 ) (5,246 ) Balance, December 31, 2017 $ (2,160 ) $ (531 ) $ (16,342 ) $ (19,033 )

Quarterly Results of Operations

Quarterly Results of Operations (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations (Unaudited)	Note 24—Quarterly Results of Operations (Unaudited) The following is a summary of the quarterly results of operations, for the years ended December 31, 2017 and 2016: Three Months Ended, (In thousands) December 31, 2017 September 30, 2017 June 30, 2017 March 31, 2017 Interest income $ 108,370 $ 99,503 $ 99,375 $ 89,619 Interest expense 20,459 18,340 16,991 14,861 Net interest income 87,911 81,163 82,384 74,758 Provision for credit losses (4,475 ) 1,723 6,701 5,786 Noninterest income (1) 25,656 27,124 22,989 24,105 Noninterest expense 66,371 56,530 56,134 54,321 Income before income taxes 51,671 50,034 42,538 38,756 Provision for income taxes 36,980 17,457 13,570 12,639 Net income $ 14,691 $ 32,577 $ 28,968 $ 26,117 Earnings per common share (Basic) $ 0.18 $ 0.39 $ 0.35 $ 0.35 Earnings per common share (Diluted) 0.17 0.39 0.35 0.35 Three Months Ended, (In thousands) December 31, 2016 September 30, 2016 June 30, 2016 March 31, 2016 Interest income $ 87,068 $ 84,654 $ 82,921 $ 80,607 Interest expense 14,570 14,228 13,672 13,341 Net interest income 72,498 70,426 69,249 67,266 Provision for credit losses (5,222 ) 29,627 14,471 10,472 Noninterest income (2) 22,361 22,791 23,105 20,146 Noninterest expense 55,394 54,876 55,868 54,042 Income before income taxes 44,687 8,714 22,015 22,898 Provision for income taxes 15,701 2,107 7,175 7,557 Net income $ 28,986 $ 6,607 $ 14,840 $ 15,341 Earnings per common share (Basic) $ 0.39 $ 0.09 $ 0.20 $ 0.20 Earnings per common share (Diluted) 0.38 0.09 0.20 0.20 (1 ) (2) Includes net securities gains of $1.3 million, $1.4 million, $1.0 million and $64 thousand during the fourth, third, second and first quarters of 2016, respectively.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Note 25—Subsequent Events On February 8, 2018, the Company priced its previously announced secondary public offering of 8,000,000 shares of the Company’s Class A common stock, par value $0.01 per share (the “Class A Common Stock”), by Cadence Bancorp, LLC, the controlling stockholder of the Company (the “Selling Stockholder”). The Selling Stockholder completed the secondary offering on February 13, 2018. In addition, the underwriters exercised in full their 30-day option to purchase an additional 1,200,000 shares of the Class A Common Stock from the Selling Stockholder on February 13, 2018. The Company itself did not sell any shares of Class A Common Stock and did not receive any proceeds from the offering, and the offering did not change the number of shares of the Company’s Class A Common Stock that are currently outstanding. On January 24, 2018, the Board of Directors of Cadence declared a quarterly cash dividend in the amount of $0.125 per share of common stock, representing an annualized dividend of $0.50 per share. The dividend will be paid on March 20, 2018 to holders of record of the Class A common stock on March 1, 2018.

Summary of Accounting Policies

Summary of Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The Company and its subsidiaries follow accounting principles generally accepted in the United States of America, including, where applicable, general practices within the banking industry. The consolidated financial statements include the accounts of the Company and its subsidiaries. Significant intercompany accounts and transactions have been eliminated in consolidation. The assessment of whether or not the Company has a controlling interest (i.e., the primary beneficiary) in a variable-interest entity (“VIE”) is performed on an on-going basis. All equity investments in non-consolidated VIEs are included in “other assets” in the Company’s consolidated balance sheets (Note 19). Certain amounts reported in prior years have been reclassified to conform to the 2017 presentation. These reclassifications did not materially impact the Company’s consolidated balance sheets or consolidated statements of income. In accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 855, “Subsequent Events,” the Company’s Management has evaluated subsequent events for potential recognition or disclosure in the consolidated financial statements through the date of the issuance of these consolidated financial statements. No subsequent events were identified that would have required a change to the consolidated financial statements or disclosure in the notes to the consolidated financial statements, other than as disclosed in Note 25, Subsequent Events.
Stock Split	Stock Split On March 30, 2017, the Board of Directors approved a 75-for-one stock split of the Company’s common stock. The stock split occurred on April 7, 2017. The effect of the stock split on outstanding shares and earnings per share has been retroactively applied to all periods presented.
Nature of Operations	Nature of Operations The Company’s subsidiaries include: • Town & Country Insurance Agency, Inc., dba Cadence Insurance—full service insurance agency; and • The Bank. The Bank operates under a national bank charter and is subject to regulation by the Office of the Comptroller of the Currency (OCC). The Bank provides lending services in Georgia and full banking services in five southern states: Alabama, Florida, Mississippi, Tennessee, and Texas. The Bank’s subsidiaries include: • Linscomb & Williams Inc. —financial advisory firm; and • Cadence Investment Services, Inc.—provides investment and insurance products. The Company and the Bank also have certain other non-operating and immaterial subsidiaries.
Branch Sales	Branch Sales In March and October, 2015, the Company sold the assets and transferred the liabilities of eight branches in Florida (6) and Georgia (2) and recognized a loss of $1.5 million. The following table summarizes the allocation of the sale price to assets sold and liabilities transferred: (In thousands) 2015 Cash on hand $ 1,254 Loans 42,477 Premises and equipment 3,095 Other assets 113 Total assets sold 46,939 Deposits 253,823 Other liabilities 301 Total liabilities transferred 254,124 Cash paid $ 207,185
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are susceptible to significant change in the near term are the allowance for credit losses, valuation of and accounting for acquired credit impaired loans, valuation of goodwill, intangible assets and deferred income taxes.
Securities	Securities Securities are accounted for as follows: Securities Available-for-Sale Securities classified as available-for-sale are those securities that are intended to be held for an indefinite period of time, but not necessarily to maturity. Any decision to sell a security classified as available-for-sale would be based on various factors, including movements in interest rates, liquidity needs, security risk assessments, changes in the mix of assets and liabilities and other similar factors. These securities are carried at their estimated fair value, and the net unrealized gain or loss is reported as accumulated other comprehensive income, net of tax, until realized. Premiums and discounts are recognized in interest income using the effective interest method. Realized gains and losses on the sale of securities available-for-sale are determined by specific identification using the adjusted cost on a trade date basis and are included in securities gains (losses), net. Securities Held-to-Maturity Securities classified as held-to-maturity are those securities for which there is a positive intent and ability to hold to maturity. These securities are carried at cost, adjusted for amortization of premium and accretion of discount, computed by the interest method. Trading Account Securities Trading account securities are securities that are held for the purpose of selling them at a profit. The Company had no trading account securities as of December 31, 2017 or 2016. FHLB and FRB Stock The Company has ownership in Federal Home Loan Bank “FHLB” and Federal Reserve Bank “FRB” stock which do not have a readily determinable fair value and no quoted market values, as ownership is restricted to member institutions, and all transactions take place at par value with the FHLB or FRB as the only purchaser. Therefore, the Company accounts for these investments as long-term assets and carries them at cost. Management’s determination as to whether these investments are impaired is based on management’s assessment of the ultimate recoverability of the par value (cost) rather than recognizing temporary declines in fair value. In order to become a member of the Federal Reserve System, regulations require that the Company hold a certain amount of FRB capital stock. Additionally, investment in FHLB stock is required for membership in the FHLB system and in relation to the level of FHLB outstanding borrowings.
Derivative Financial Instruments and Hedging Activities	Derivative Financial Instruments and Hedging Activities Derivative instruments are accounted for under the requirements of ASC Topic 815, “Derivatives and Hedging.” ASC Topic 815 requires companies to recognize all of their derivative instruments as either assets or liabilities in the consolidated balance sheets at fair value. The fair value of derivative positions outstanding is included in other assets and other liabilities in the accompanying consolidated balance sheets and in the net change in each of these financial statement line items in the accompanying consolidated statements of cash flows. The Company does not speculate using derivative instruments. Interest Rate Lock Commitments In the ordinary course of business, the Company enters into certain commitments with customers in connection with residential mortgage loan applications. Such commitments are considered derivatives under current accounting guidance and are required to be recorded at fair value. The change in fair value of these instruments is reflected currently in the mortgage banking revenue of the consolidated statements of income. Forward Sales Commitments The Company enters into forward sales commitments of mortgage-backed securities (“MBS”) with investors to mitigate the effect of the interest rate risk inherent in providing interest rate lock commitments to customers. During the period from commitment date to closing date, the Company is subject to the risk that market rates of interest may change. In an effort to mitigate such risk, forward delivery sales commitments, under which the Company agrees to deliver certain MBS, are established. These commitments are non-hedging derivatives in accordance with current accounting guidance and recorded at fair value, with changes in fair value reflected currently in the mortgage banking revenue of the consolidated statements of income. Interest Rate Swap, Floor and Cap Agreements Not Designated as Hedging Derivatives The Company enters into interest rate swap, floor and cap agreements on commercial loans with customers to meet the financing needs and interest rate risk management needs of its customers. At the same time, the Company enters into an offsetting interest rate swap, floor or cap agreement with a financial institution in order to minimize the Company’s interest rate risk. These interest rate swap and cap agreements are non-hedging derivatives and are recorded at fair value with changes in fair value reflected in noninterest income. The fair value of these derivatives is recorded on the consolidated balance sheets in other assets and other liabilities. Interest Rate Swap Agreements Designated as Cash Flow Hedges Cash flow hedge relationships mitigate exposure to the variability of future cash flows or other forecasted transactions. The Company uses interest rate swaps to manage overall cash flow changes related to interest rate risk exposure on benchmark interest rate loans. The effective portion of the gain or loss related to the derivative instrument is recognized as a component of other comprehensive income and subsequently reclassified into interest income when the forecasted transaction affects income. The ineffective portion of the gain or loss is recognized immediately as noninterest income. The Company assesses the effectiveness of the hedging derivative by comparing the change in fair value of the respective derivative instrument and the change in fair value of an effective hypothetical derivative instrument. Foreign Currency Contracts The Company enters into certain foreign currency exchange contracts on behalf of its clients to facilitate their risk management strategies, while at the same time entering into offsetting foreign currency exchange contracts in order to minimize the Company’s foreign currency exchange risk. The contracts are short term in nature, and any gain or loss incurred at settlement is recorded as other noninterest income or other noninterest expense. The fair value of these contracts is reported in other assets and other liabilities. The Company does not apply hedge accounting to these contracts. Counterparty Credit Risk Derivative contracts involve the risk of dealing with both bank customers and institutional derivative counterparties and their ability to meet contractual terms. Under Company policy, institutional counterparties must be approved by the Company’s Asset/Liability Management Committee. The Company’s credit exposure on derivatives is limited to the net fair value for each counterparty. Refer to Note 6 for further discussion and details of derivative financial instruments and hedging activities.
Transfers of Financial Assets	Transfers of Financial Assets Transfers of financials assets are accounted for as sales when control over the transferred assets is surrendered. Control is generally considered to have been surrendered when 1) the transferred assets are legally isolated from the Company or its consolidated affiliates, even in bankruptcy or other receivership, 2) the transferee has the right to pledge or exchange the assets with no conditions that constrain the transferee and provide more than a trivial benefit to the Company, and 3) the Company does not maintain the obligation or unilateral ability to reclaim or repurchase the assets. If these sale criteria are met, the transferred assets are removed from the Company’s balance sheet and a gain or loss on sale is recognized. If not met, the transfer is recorded as a secured borrowing, and the assets remain on the Company’s balance sheet, the proceeds from the transaction are recognized as a liability, and gain or loss on sale is deferred until the sale criterion are achieved. All transfers of financial assets in the reported periods have qualified and been recorded as sales.
Loans Held for Sale	Loans Held for Sale Mortgage Loans Held for Sale Mortgage loans originated and intended for sale in the secondary market are carried at the lower of cost or estimated fair value in the aggregate. Generally, loans in this category are sold within thirty days. These loans are primarily sold with the mortgage servicing rights released. Fees on mortgage loans sold individually in the secondary market, including origination fees, service release premiums, processing and administrative fees, and application fees, are recognized as mortgage banking revenue in the period in which the loans are sold. These loans are underwritten to the standards of upstream correspondents and are held on the Company’s consolidated balance sheets until the loans are sold. Buyers generally have recourse to return a purchased loan to the Company under limited circumstances. Recourse conditions may include early payment default, breach of representations or warranties, and documentation deficiencies. During 2017, 2016 and 2015, an insignificant number of loans were returned to the Company. Commercial Loans Held for Sale The Company originates certain commercial loans for which a portion is intended for sale. The Company also transfers certain commercial loans to held for sale when management has the intent to sell the loan or a portion of the loan in the near term. These held for sale loans are recorded at the lower of cost or estimated fair value. At the time of transfer, write-downs on the loans are recorded as charge-offs and a new cost basis is established. Any subsequent lower of cost or market adjustment is determined on an individual loan basis and is recognized as a valuation allowance with any charges included in other noninterest expense. Gains and losses on the sale of these loans are included in other noninterest income when realized. A summary of the loans held for sale at December 31, 2017 and 2016 is as follows: As of December 31, (In thousands) 2017 2016 Mortgage loans held for sale $ 5,834 $ 8,369 Commercial loans held for sale 55,525 9,453 Loans held for sale $ 61,359 $ 17,822
Loans (Excluding Acquired Credit Impaired Loans)	Loans (Excluding Acquired Credit Impaired Loans) Loans include loans that are originated by the Company and acquired loans that are not considered impaired at acquisition. Loans originated by the Company are carried at the principal amount outstanding adjusted for the allowance for credit losses, net of deferred origination fees, and unamortized discounts and premiums. Interest income is recognized based on the principal balance outstanding and the stated rate of the loan. Loan origination fees and certain direct origination costs are capitalized and recognized as an adjustment of the yield on the related loan. Loans acquired through acquisition are initially recorded at fair value. Discounts created when the loans were recorded at their estimated fair values at acquisition are accreted over the remaining term of the loan as an adjustment to the related loan’s yield. Commercial loans, including small business loans, are generally placed on nonaccrual status when principal or interest is past due ninety days or more unless the loan is well secured and in the process of collection, or when the loan is specifically determined to be impaired. Consumer loans, including residential first and second lien loans secured by real estate, are generally placed on nonaccrual status when they are 120 or more days past due. The accrual of interest, as well as the amortization/accretion of any remaining unamortized net deferred fees or costs and discount or premium, is generally discontinued at the time the loan is placed on nonaccrual status. All accrued but uncollected interest for loans that are placed on nonaccrual status is reversed through interest income. Cash receipts received on nonaccrual loans are generally applied against principal until the loan has been collected in full, after which time any additional cash receipts are recognized as interest income (i.e., cost recovery method). However, interest may be accounted for under the cash-basis method as long as the remaining recorded investment in the loan is deemed fully collectible. Non-impaired loans are evaluated for potential charge-off in accordance with the parameters discussed below or when the loan is placed on non-accrual status, whichever is earlier. Loans within the commercial portfolio are generally evaluated for charge-off at 90 days past due, unless both well-secured and in the process of collection. Closed and open-end residential mortgage and consumer loans are evaluated for charge-off no later than 120 days past due. Any outstanding loan balance in excess of the fair value of the collateral less costs to sell is charged-off no later than 180 days past due for loans secured by real estate. For non-real estate secured loans, in lieu of charging off the entire loan balance, loans may be written down to the fair value of the collateral less costs to sell if repossession of collateral is assured and in process. A loan is considered to be impaired when it appears probable that the entire amount contractually due will not be collected. Factors considered in determining impairment include payment status, collateral values, and the probability of collecting scheduled payments of principal and interest when due. The measurement of impaired loans is based on the present value of expected future cash flows discounted at the loan’s effective interest rate or the loan’s observable market price, or based on the fair value of the collateral if the loan is collateral dependent. Included in impaired loans are loans considered troubled debt restructurings (“TDRs”). The Company attempts to work with borrowers when necessary to extend or modify loan terms to better align with the borrower’s ability to repay. Extensions and modifications to loans are made in accordance with internal policies and guidelines which conform to regulatory guidance. A modification is classified as a TDR if the borrower is experiencing financial difficulty and it is determined that the Company has granted a concession to the borrower. The Company may determine that a borrower is experiencing financial difficulty if the borrower is currently in default on any of its debt, or if it is probable that a borrower may default in the foreseeable future without the modification. Concessions could include reductions of interest rates, extension of the maturity date at a rate lower than current market rate for a new loan with similar risk, reduction of accrued interest, principal forgiveness, forbearance, or other concessions. The assessments of whether a borrower is experiencing or will likely experience financial difficulty and whether a concession has been granted is highly subjective in nature, and management’s judgment is required when determining whether a modification is classified as a TDR. Current amendments to the accounting guidance preclude a creditor from using the effective interest rate test in the debtor’s guidance on restructuring of payables (paragraph 470-60-55-10) when evaluating whether a restructuring constitutes a TDR.
Allowance for Credit Losses	Allowance for Credit Losses The allowance for credit losses (“ACL”) is established through charges to income in the form of a provision for credit losses. The ACL is maintained at a level that management believes is adequate to absorb all probable losses on loans inherent in the loan portfolio as of the reporting date. Events that are not within the Company’s control, such as changes in economic factors, could change subsequent to the reporting date and could cause the ACL to be overstated or understated. The amount of the ACL is affected by loan charge-offs, which decrease the ACL; recoveries on loans previously charged off, which increase the ACL; and the provision for credit losses charged to income, which increases the ACL. In determining the provision for credit losses, management monitors fluctuations in the ACL resulting from actual charge-offs and recoveries and reviews the size and composition of the loan portfolio in light of current and anticipated economic conditions. The ACL is comprised of the following four components: • Specific reserves are recorded on loans reviewed individually for impairment. Generally, all loans that are individually identified as impaired are reviewed on a quarterly basis in order to determine whether a specific reserve is required. A loan is considered impaired when, based on current information, it is probable that we will not receive all amounts due in accordance with the contractual terms of the loan agreement. Once a loan has been identified as impaired, management measures impairment in accordance with ASC Topic 310, “Receivables.” The measurement of impaired loans is based on the present value of expected future cash flows discounted at the loan’s effective interest rate or the loan’s observable market price, or based on the fair value of the collateral if the loan is collateral dependent. When management’s measured value of the impaired loan is less than the recorded investment in the loan, the amount of the impairment is recorded as a specific reserve. These specific reserves are determined on an individual loan basis based on management’s current evaluation of the loss exposure for each credit, given the payment status, the financial condition of the borrower and any guarantors and the value of any underlying collateral. Loans that are individually identified as impaired are excluded from the general reserve calculation described below. Changes in specific reserves from period to period are the result of changes in the circumstances of individual loans such as charge-offs, payments received, changes in collateral values or other factors. • For loans not considered to be impaired, a general reserve is maintained for each loan segment in the loan portfolio. Due to the growth of the credit portfolio into new geographic areas and into new commercial segmentations and the lack of seasoning of the portfolio, the Company recognizes there is limited historical loss information to adequately estimate loss rate bands based primarily on historical loss data. Therefore, external loss data was acquired from the research arm of a nationally recognized risk rating agency to act as a proxy for loss rates within the ACL model until sufficient loss history can be accumulated from the Company’s loss experience in these segments. These loss rate bands were developed specifically for the Company’s customer risk profile and portfolio mix. The Company monitors actual loss experience for each loan segment for adjustments required to the loss rates utilized. • In assessing the overall risk of the credit portfolio, the ACL Committee also considers the following qualitative factors that may indicate additional credit losses within the current credit portfolio. Management discretion dictates how these factors should affect certain segments (or the entire portfolio) according to a number of basis points to be added to (or subtracted from) loan loss rates. By their nature, qualitative adjustments attempt to quantify and standardize factors that serve as “leading indicators” of credit deterioration or improvement. These primary adjustment factors include, but are not limited to the following: • Lending policies, procedures, practices or philosophy, including underwriting standards and collection, charge-off and recovery practices • Changes in national and service market economic and business conditions that could affect the level of default rates or the level of losses once a default has occurred within the Bank’s existing loan portfolio • Changes in the nature or size of the portfolio • Changes in portfolio collateral values • Changes in the experience, ability, and depth of lending management and other relevant staff • Volume and/or severity of past due and classified credits or trends in the volume of losses, non-accrual credits, impaired credits and other credit modifications • Quality of the institution’s credit review system and processes and the degree of oversight by bank management and the board of directors • Concentrations of credit such as industry and lines of business • Competition and legal and regulatory requirements or other external factors. • In connection with acquisitions (see Accounting for Acquired Loans and FDIC Loss Share Receivable Management presents the quarterly review of the ACL to the Bank’s Board of Directors, indicating any recommendations as to adjustments in the ACL. This evaluation is inherently subjective as it requires estimates that are susceptible to significant revision as more information becomes available or as events change. The reserve for unfunded commitments is determined by assessing three distinct pieces: unfunded commitment volatility in the portfolio (excluding commitments related to letters of credit and commitment letters), adverse letters of credit, and adverse lines of credit. Unfunded commitment volatility is calculated on a trailing eight quarter basis; the resulting expected funding amount is then reserved for based on the current combined reserve rate of the originated and ANCI loans. Adverse lines and letters of credit are assessed individually based on funding and loss expectations as of the period end. The reserve for unfunded commitments is recorded in other liabilities and other noninterest expense separate from the allowance and provision for credit losses. As of December 31, 2017 and 2016 the reserve for unfunded commitments totaled $0.8 million and $1.6 million, respectively.
Accounting for Acquired Loans and FDIC Loss Share Receivable	Accounting for Acquired Loans and FDIC Loss Share Receivable Acquired Loans The Company accounts for its acquisitions under ASC Topic 805, which requires the use of the acquisition method of accounting. All identifiable assets acquired, including loans, are recorded at fair value. No ACL related to the acquired loans is recorded on the acquisition date as the fair value of the loans acquired incorporates assumptions regarding credit risk. Loans acquired are recorded at fair value in accordance with the fair value methodology prescribed in ASC Topic 820, exclusive of the shared-loss agreements with the Federal Deposit Insurance Corporation (“FDIC”) (see “FDIC Indemnification Asset” below). The fair value estimates associated with the loans include estimates related to the amount and timing of undiscounted expected principal, interest and other cash flows, as well as the appropriate discount rate. At the time of acquisition, the Company estimated the fair value of the total acquired loan portfolio by segregating the portfolio into loan pools with similar characteristics and certain specifically-reviewed non-homogeneous loans. The similar characteristics used to establish the pools included: • Risk rating, • The loan type based on regulatory reporting guidelines; namely whether the loan was a residential, construction, consumer, or commercial loan, and • The nature of collateral. From these pools, the Company used certain loan information, including outstanding principal balance, estimated probability of default and loss given default, weighted average maturity, weighted average term to re-price (if a variable rate loan), estimated prepayment rates, and weighted average interest rate to estimate the expected cash flow for each loan pool. For the specifically-reviewed loans expected cash flows were determined for each loan based on current performance and collateral values, if the loan is collateral dependent. The Company accounts for and evaluates acquired credit impaired (“ACI”) loans in accordance with the provisions of ASC Topic 310-30. When ACI loans exhibit evidence of credit deterioration since origination and it is probable at the date of acquisition that the Company will not collect all principal and interest payments in accordance with the terms of the loan agreement, the expected shortfall in future cash flows, as compared to the contractual amount due, is recognized as a non-accretable discount. Any excess of expected cash flows over the acquisition date fair value is known as the accretable discount, and is recognized as accretion income over the life of each pool or individual loan. ACI loans that meet the criteria for non-accrual of interest at the time of acquisition may be considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if the timing and expected cash flows on such loans can be reasonably estimated and if collection of the new carrying value of such loans is expected. However, if the timing or amount of the expected cash flows cannot be reasonably estimated an ACI loan may be placed in nonaccruing status. Expected cash flows over the acquisition date fair value are periodically re-estimated utilizing the same cash flow methodology used at the time of acquisition and subsequent decreases to the expected cash flows will generally result in a provision for loan losses charge to the Company’s consolidated statements of income. Conversely, subsequent increases in expected cash flows result in a transfer from the non-accretable discount to the accretable discount, which would have a positive impact on accretion income prospectively. These cash flow evaluations are inherently subjective as they require material estimates, all of which may be susceptible to significant change. FDIC Indemnification Asset An FDIC indemnification asset results from the loss sharing agreement in an FDIC-assisted transaction and is measured separately from the related covered assets as they are not contractually embedded in those assets and are not transferable should the Company choose to dispose of the covered assets. The FDIC indemnification asset represents the estimated fair value of expected reimbursements from the FDIC for losses on covered loans and other real estate owned (“OREO”). As indemnified assets are resolved and the Company is reimbursed by the FDIC for the value of the resolved portion of the FDIC indemnification asset, the Company reduces the carrying value of the FDIC indemnification asset. As of December 31, 2012, the Company had submitted claims in excess of the first threshold of $347 million established at acquisition and was reimbursed the 80% of the covered losses by the FDIC up to this initial threshold. Subsequent claims between $347 million and $504 million are not reimbursable under the loss share agreement. The Company’s claims did not exceed the second threshold of $504 million, over which losses are reimbursed at 80%. On January 5, 2016, a settlement agreement was finalized with the FDIC to terminate the loss share agreement at a nominal cost and the Company had no FDIC indemnification asset recorded as of December 31, 2017 and 2016.
Premises and Equipment	Premises and Equipment Premises and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization are determined using the straight-line method at rates calculated to depreciate or amortize the cost of assets over their estimated useful lives. Maintenance and repairs of property and equipment are charged to expense, and major improvements that extend the useful life of the asset are capitalized. Upon retirement, sale, or other disposition of property and equipment, the cost and accumulated depreciation are eliminated from the accounts, and any gains or losses are included in income. The Company leases various premises and equipment under operating leases. The leases have varying terms, with most containing renewal or first-right-of-refusal options for multi-year periods and annual increases in base rates. Leasehold improvements are depreciated over the lesser of the estimated useful life or the lease term.
Other Real Estate	Other Real Estate OREO consists of properties acquired through foreclosure and unutilized bank-owned properties. These properties, as held for sale properties, are recorded at fair value, less estimated costs to sell, on the date of foreclosure establishing a new cost basis for the property. Subsequent to the foreclosure date the OREO is maintained at the lower of cost or fair value. Any write-down to fair value required at the time of foreclosure is charged to the ACL. Subsequent gains or losses on other real estate resulting from the sale of the property or additional valuation allowances required due to further declines in fair value are reported in other noninterest expense. The amount of loans in the process of foreclosure or physical possession for single-family residential properties was $4.4 million and $0.6 million as of December 31, 2017 and 2016, respectively. The amount of residential real estate properties held in OREO was $2.7 million and $5.1 million as of December 31, 2017 and 2016, respectively.
Net Profits Interests	Net Profits Interests The Bank owns net profits interests in oil and gas reserves received in connection with the reorganization under bankruptcy of two loan customers. These interests are considered financial interests and are recorded at estimated fair value using discounted cash flow analyses applied to the expected cash flows from the producing developed wells. Because the expected cash flows are based on the current and projected prices for oil and gas, the fair value is subject to change based on these commodity markets. Any adjustments to the fair value will be recorded in other noninterest income. The amount in other assets was $15.8 million and $19.4 million as of December 31, 2017 and 2016, respectively. There were no net profits interests prior to 2016. See Note 18, Disclosure About Fair Value of Financial Instruments, for more information.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill is accounted for in accordance with ASC Topic 350, and accordingly is not amortized but is evaluated for impairment at least annually in the fourth quarter or more frequently if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount. As part of its testing, the Company may elect to first assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the results of the qualitative assessment indicate that more likely than not a reporting unit’s fair value is less than its carrying amount, the Company determines the fair value of the respective reporting unit (through the application of various quantitative valuation methodologies) relative to its carrying amount to determine whether quantitative indicators of potential impairment are present (i.e., Step 1). The Company may also elect to bypass the qualitative assessment and begin with Step 1. If the results of Step 1 indicate that the fair value of the reporting unit may be below its carrying amount, the Company determines the fair value of the reporting unit’s assets and liabilities, considering deferred taxes, and then measures impairment loss by comparing the implied fair value of goodwill with the carrying amount of that goodwill (i.e., Step 2). A reporting unit is defined as an operating segment or a component of that operating segment, as defined in ASC 280. Reporting units may vary, depending on the level at which performance of the segment is reviewed. No impairment was identified in any reporting unit in 2017, 2016 or 2015. Other identifiable intangible assets consist primarily of the core deposit premiums and customer relationships arising from acquisitions. These intangibles were established using the discounted cash flow approach and are being amortized using an accelerated method over the estimated remaining life of each intangible recorded at acquisition. These finite-lived intangible assets are reviewed for impairment when events or changes in circumstances indicate that the asset’s carrying amount may not be recoverable from undiscounted future cash flows or that it may exceed its fair value.
Income Taxes	Income Taxes The Company and its significant subsidiaries are subject to income taxes in federal, state and local jurisdictions, and such corporations account for income taxes under the asset and liability method in accordance with ASC Topic 740. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and net operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The recognition of a net deferred tax asset is dependent upon a “more likely than not” expectation of realization of the net deferred tax asset, based upon the analysis of available evidence. The net deferred tax asset recoverability is calculated using a consistent approach, which considers the relative impact of negative and positive evidence, including review of historical financial performance, and all sources of future taxable income, such as projections of future taxable income exclusive of future reversals of temporary differences and carryforwards, tax planning strategies, and any carryback availability. A valuation allowance is required to sufficiently reduce the net deferred tax asset to the amount that is expected to be realized on a “more likely than not” basis. Changes in the valuation allowance are generally recorded through income.
Cash Surrender Value of Life Insurance Policies	Cash Surrender Value of Life Insurance The Company invests in bank-owned life insurance (“BOLI”), which involves the purchasing of life insurance on selected employees. The Company is the owner of the policies and, accordingly, the cash surrender value of the policies is included in total assets, and increases in cash surrender values are reported as income in the consolidated statements of income. The cash value accumulation on BOLI is permanently tax deferred if the policy is held to the insured person’s death and certain other conditions are met.
Revenue Recognition	Revenue Recognition Service Charges on Deposit Accounts Service charges on deposit accounts consist of non-sufficient funds fees, account analysis fees, and other service charges on deposits which consist primarily of monthly account fees. Non-sufficient funds fees are recognized at the time the account overdraft occurs in accordance with regulatory guidelines. Account analysis fees consist of fees charged to certain commercial demand deposit accounts based upon account activity (and reduced by a credit which is based upon cash levels in the account). Insurance Commissions and Fees Commission revenue is recognized as of the effective date of the insurance policy, the date the customer is billed, or the date the commission is received, whichever is later. The Company also receives contingent commissions from insurance companies as additional incentive for achieving specified premium volume goals and/or the loss experience of the insurance placed. The Company recognizes contingent commissions from insurance companies when determinable, which is generally when such commissions are received or when data is received from the insurance companies that allow the reasonable estimation of these amounts. Commission adjustments are recorded, including policy cancellations and override commissions, when the adjustments become reasonably estimable, which is generally in the period in which they occur. Assets Under Administration and Asset Management Fees The Company does not include assets held in fiduciary or agency capacities in the consolidated balance sheets, as such items are not assets of the Company. Fees from asset management activities are recorded on an accrual basis, over the period in which the service is provided. Fees are a function of the market value of assets administered and managed, the volume of transactions, and fees for other services rendered, as set forth in the underlying client agreement. This revenue recognition involves the use of estimates and assumptions, including components that are calculated based on estimated asset valuations and transaction volumes. Credit Related Fees Credit related fees primarily include fees assessed on the unused portion of commercial lines of credit (“unused commitment fees”) and syndication agent fees. Unused commitment fees are recognized when earned. Syndication agent fees are generally recognized when the transaction is complete. Bankcard Fees Bankcard fees include primarily bankcard interchange revenue, which is recorded as revenue when earned.
Per Share Amounts	Per Share Amounts Basic earnings per common share represents income available to common shareholders divided by the weighted average number of common shares outstanding during the period. Diluted earnings per common share is calculated by dividing net income available to common shareholders by the weighted-average number of common shares outstanding during the period, plus the effect of outstanding equity-based compensation awards if dilutive.
Comprehensive Income	Comprehensive Income Accounting principles generally require that recognized revenue, expenses, gains, and losses be included in net income. Although certain changes in assets and liabilities, such as unrealized gains and losses on available for sale securities, pension liability and cash flow hedges, are reported as a separate component of the shareholder’s equity section of the consolidated balance sheets, such items, along with net income, are components of comprehensive income.
Employee Benefits	Employee Benefits The Company offers a 401(k) defined contribution benefit plan to its employees. The plan provides for a 100% match of employee contributions up to three percent of employee compensation and a 50% match of employee contributions on the next two percent of employee compensation. All contributions and related earnings are 100% vested. Employees of the legacy Cadence Bank hired prior to January 1, 2001 participate in a noncontributory defined benefit pension plan. The plan calls for benefits to be paid to eligible employees at retirement based primarily upon years of service and compensation. Contributions to the plan reflect benefits attributed to employees’ services to date, as well as services expected to be provided in the future. The annual pension cost charged to expense is actuarially determined in accordance with the provisions of ASC Topic 715, “Compensation-Retirement Benefits.” The plan was amended effective January 1, 2001, to close participation in the plan, and employees hired subsequent to December 31, 2000, are not eligible to participate. The Company has a supplemental retirement plan that originated from an acquired bank for certain directors and officers of that acquired bank. The annual cost charged to expense and the estimated present values of the projected payments are actuarially determined in accordance with the provisions of ASC Topic 715. Prior to its acquisition by Cadence Bancorp, LLC (“LLC”), the Company entered into agreements with certain senior officers to establish an unqualified supplemental retirement plan. The plan allows for fixed payment amounts to begin on a monthly basis at age 65. The annual cost charged to expense and the estimated present value of the projected payments was determined in accordance with the provisions of ASC Topic 715. The present value of projected payments is recorded as a liability, in accordance with ASC Subtopic 710-30 in the Company’s consolidated balance sheets. The Company provides a voluntary deferred compensation plan for certain of its executive and senior officers. Under this plan, the participants may defer up to 25% of their base compensation and 100% of certain incentive compensation. The Company may, but is not obligated to, contribute to the plan. Amounts contributed to this plan are credited to a separate account for each participant and are subject to a risk of loss in the event of the Company’s insolvency. The Company made no contributions to this plan in 2017, 2016 or 2015.
Equity-Based Compensation and Equity Incentive Plan	Equity-Based Compensation and Equity Incentive Plan The Company maintains an equity incentive plan that provides for the granting of various forms of incentive equity-based compensation. The Company values these units at the grant date fair value and recognizes expense over the requisite service period. The Company’s equity–based compensation costs are recorded as a component of salaries and employee benefits in the consolidated statements of income. Compensation costs are recognized for restricted stock units (“RSU”s) issued to employees based on the fair value of these awards at the date of grant. A Monte-Carlo simulation was used to value the RSUs by generating the possible future value of the Company’s common stock price at the settlement date and the number of shares earned. The fair value of the RSUs is then estimated by averaging the value for all paths and discounting the results using a risk-free rate.
Long Term Incentive Plan	Long Term Incentive Plan The Company offers a long-term incentive plan to certain employees that provides for cash compensation, half of which are based on the value of the shares of LLC, or the quoted market price of the Company’s common stock, as determined on at least a quarterly basis. The awards are generally subject to a 36 month vesting period and the attainment of certain three-year profitability levels. The Company adjusts the accrual related to this plan on at least a quarterly basis, based on the phantom shares awarded, and the fair value of LLC’s or Company’s stock. Expense under this plan was $7.3 million, $4.4 million and $1.6 million as of December 31, 2017, 2016 and 2015, respectively.
Cash Flows	Cash Flows For purposes of reporting cash flows, cash and cash equivalents include cash on hand and amounts due from banks, interest-bearing deposits with banks, and federal funds sold. Generally, federal funds are sold for one to seven day periods. Cash flows from loans, either originated or acquired, are classified at the time according to management’s intent to either sell or hold the loan for the foreseeable future. When management’s intent is to hold the loan for the foreseeable future, the cash flows of that loan are presented as investing cash flows.
Off-Balance Sheet Financial Instruments	Off-Balance Sheet Financial Instruments In the ordinary course of business, the Company enters into off-balance sheet financial instruments consisting of commitments to extend credit, credit card lines, standby letters of credit and commitments to purchase securities. Such financial instruments are recorded in the consolidated financial statements when they are exercised.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value estimates are made at a specific point in time, based on relevant market information and other information about the financial instrument. These estimates do not reflect any premium or discount that could result from offering for sale, at one time, the entire holdings of a particular financial instrument. Because no market exists for a portion of the financial instruments, fair value estimates are also based on judgments regarding estimated cash flows, current economic conditions, risk characteristics of various financial instruments, and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and, therefore, cannot be determined with precision. Changes in assumptions could significantly affect the estimates. Management employs independent third-party pricing services to provide fair value estimates for the Company’s investment securities available for sale and held to maturity. Fair values for investment securities and certain derivative financial instruments are typically the prices supplied by a third-party pricing service or an unrelated counterparty, which utilize quoted market prices, broker/dealer quotations for identical or similar securities, and/or inputs that are observable in the market, either directly or indirectly, for substantially similar securities. Level 1 securities are typically exchange quoted prices. Level 2 securities are typically matrix priced by a third-party pricing service to calculate the fair value. Such fair value measurements consider observable data, such as relevant broker/dealer quotes, market spreads, cash flows, yield curves, live trading levels, trade execution data, market consensus prepayments speeds, credit information, and the respective terms and conditions for debt instruments. Level 3 instruments’ value is determined using pricing models, discounted cash flow models and similar techniques, and may also include the use of market prices of assets or liabilities that are not directly comparable to the subject asset or liability. These methods of valuation may result in a significant portion of the fair value being derived from unobservable assumptions that reflect the Company’s own estimates for assumptions that market participants would use in pricing the asset or liability. Management uses various validation procedures to validate the prices received from pricing services and quotations received from dealers are reasonable for each relevant financial instrument, including reference to relevant broker/dealer quotes or other market quotes and a review of valuations and trade activity of comparable securities. Consideration is given to the nature of the quotes (e.g., indicative or firm) and the relationship of recently evidenced market activity to the prices provided by the third-party pricing service. Understanding the third-party pricing service’s valuation methods, assumptions and inputs used by the firm is an important part of the process of determining that reasonable and reliable fair values are being obtained. Management evaluates quantitative and qualitative information provided by the third-party pricing services to assess whether they continue to exhibit the high level of expertise and internal controls that management relies upon. Fair value estimates are based on existing financial instruments on the consolidated balance sheets, without attempting to estimate the value of anticipated future business and the value of assets and liabilities that are not considered financial instruments. Significant assets and liabilities that are not considered financial instruments include deferred income taxes, premises and equipment, goodwill and other intangible assets. In addition, the income tax ramifications related to the realization of the unrealized gains and losses on available for sale investment securities can have a significant effect on fair value estimates and have not been considered in any of the estimates. For further information about fair value measurements refer to Note 18.
Recently Adopted and Pending Accounting Pronouncements	Recently Adopted Accounting Pronouncements In March, 2016, the FASB issued Accounting Standards Update (“ASU”) 2016-07, “Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting.” The ASU amends Topic 323 and eliminates the requirement for an investor to retrospectively apply the equity method to investments when its ownership interest (or degree of influence in an investee) increases to a level that triggers the equity method of accounting. The adoption at January 1, 2017 of ASU 2016-07 did not have a significant impact on our financial position, results of operations or cash flows. In March 2016, the FASB issued ASU 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” Under ASU 2016-09, all excess tax benefits and tax deficiencies related to share-based payment awards should be recognized as income tax expense or benefit in the income statement during the period in which they occur. Previously, such amounts were recorded in the pool of excess tax benefits included in additional paid-in capital, if such pool was available. Because excess tax benefits are no longer recognized in additional paid-in capital, the assumed proceeds from applying the treasury stock method when computing earnings per share should exclude the amount of excess tax benefits that would have previously been recognized in additional paid-in capital. Additionally, excess tax benefits should be classified along with other income tax cash flows as an operating activity rather than a financing activity, as was previously the case. ASU 2016-09 also provides that an entity can make an entity-wide accounting policy election to either estimate the number of awards that are expected to vest (current GAAP) or account for forfeitures when they occur. ASU 2016-09 changes the threshold to qualify for equity classification (rather than as a liability) to permit withholding up to the maximum statutory tax rates (rather than the minimum as was previously the case) in the applicable jurisdictions. The adoption at January 1, 2017 of ASU 2016-09 did not have a significant impact on our financial position, results of operations or cash flows. In February 2018, the FASB issued ASU No. 2018-02, “Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income (Topic 220)”, which allows an entity to elect a reclassification from accumulated other comprehensive income (AOCI) to retained earnings for the stranded tax effects resulting from the Tax Cuts and Jobs Act (“Tax Reform”). The amount of that reclassification should include the effect of changes of tax rate on the deferred tax amount, any related valuation allowance and other income tax effects on the items in AOCI. The standard requires an entity to state if an election to reclassify the tax effect to retained earnings is made along with the description of other income tax effects that are reclassified from AOCI. Effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years with early adoption permitted. The Company has elected to reclassify $5.2 million from AOCI to retained earnings in the current period. See Note 23, Accumulated Other Comprehensive Income (Loss) for more information. Pending Accounting Pronouncements In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” (ASU 2014-09), which is intended to improve and converge the financial reporting requirements for revenue contracts with customers. Previous accounting guidance comprised broad revenue recognition concepts along with numerous industry-specific requirements. The new guidance establishes a five-step model which entities must follow to recognize revenue and removes inconsistencies and weaknesses in existing guidance. The banking industry does not expect significant changes because major sources of revenue are from financial instruments that have been excluded from the scope of the new standard (including loans, derivatives, debt and equity securities, etc.). ASU 2014-09 is effective for annual and interim periods beginning after December 15, 2017, and must be retrospectively applied. Entities will have the option of presenting prior periods as impacted by the new guidance or presenting the cumulative effect of initial application along with supplementary disclosures. ASU 2014-09 requires us to change how we recognize certain recurring revenue streams within insurance commissions and fees and other categories of noninterest income; however, we do not expect these changes to have a significant impact on our consolidated financial statements. We adopted the standard in the first quarter of 2018 with an immaterial cumulative effect adjustment. 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 2016-1, among other things, (i) requires equity investments, with certain exceptions, to be measured at fair value with changes in fair value recognized in net income, (ii) simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment, (iii) eliminates the requirement for public business entities to disclose the methods and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheets, (iv) requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes, (v) requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments, (vi) requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheets or the accompanying notes to the financial statements and (viii) clarifies that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale. The Company does not expect this guidance will have a material effect on the Company’s consolidated balance sheets and consolidated statements of income. We adopted the standard in the first quarter of 2018 with an immaterial cumulative effect adjustment. In February 2016, the FASB issued ASU 2016-02, “Leases” . In June 2016, he FASB has issued ASU No. 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments”. The guidance is intended to improve financial reporting by requiring timelier recording of credit losses on loans and other financial instruments. The guidance will replace the current incurred loss accounting model with an expected loss approach and requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. The guidance requires enhanced disclosures to help investors and other financial statement users better understand significant estimates and judgments used in estimating credit losses, as well as the credit quality and underwriting standards of an organization’s portfolio. The ASU is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The Company is evaluating the effect of adopting this new accounting guidance. In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments”, in order to reduce current diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows. ASU 2016-15 will be effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The amendments should be applied using a retrospective transition method to each period presented. The Company does not expect this guidance will have a material effect on the Company’s consolidated statement of cash flows. In January 2017, the FASB issued ASU No. 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business”, which introduces amendments that are intended to clarify the definition of a business to assist companies and other reporting organizations with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The amendments are intended to narrow the current interpretation of a business. ASU No. 2017-01 will be effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within those periods. The amendments will be applied prospectively on or after the effective date. Early application of the amendments in this ASU is allowed for transactions, including when a subsidiary or group of assets is deconsolidated/derecognized, in which the acquisition date occurs before the issuance date or effective date of the amendments, only when the transaction has not been reported in financial statements that have been issued or made available for issuance. The Company does not expect this guidance will have a material effect on the Company’s consolidated balance sheets and consolidated statements of income. In January 2017, the FASB issued ASU No. 2017-04, “Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment”, which simplifies how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Therefore, any carrying amount which exceeds the reporting unit’s fair value (up to the amount of goodwill recorded) will be recognized as an impairment loss. ASU No. 2017-04 will be effective for annual reporting periods beginning after December 15, 2019, including interim reporting periods within those periods. The amendments will be applied prospectively on or after the effective date. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. Based on recent goodwill impairments tests, which did not require the application of Step 2, the Company does not expect the adoption of this ASU to have an immediate impact. In March 2017, the FASB issued ASU No. 2017-08, “Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities”, which will shorten the amortization period for callable debt securities held at a premium to the earliest call date instead of the maturity date. The amendments do not require an accounting change for securities held at a discount, which will continue to be amortized to the maturity date. ASU No. 2017-08 will be effective for annual reporting periods beginning after December 15, 2018, including interim reporting periods within those periods. The amendments should be applied using a modified-retrospective transition method as of the beginning of the period of adoption. Early adoption is permitted, including adoption in an interim period. The Company is currently assessing this pronouncement and it is not expected to have a material impact on the Company’s financial condition or results of operations. In May, 2017, the FASB issued ASU 2017-09, “Stock Compensation (Topic 718): Scope of Modification Accounting”, which clarifies when modification accounting should be applied to changes in terms or conditions of share-based payment awards. The amendments narrow the scope of modification accounting by clarifying that modification accounting should be applied to awards if the change affects the fair value, vesting conditions, or classification of the award. The amendments do not impact current disclosure requirements for modifications, regardless of whether modification accounting is required under the new guidance. ASU No. 2017-08 will be effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within those periods. The Company does not expect this guidance will have a material effect on the Company’s consolidated balance sheets and consolidated statements of income. In August 2017, the FASB issued ASU 2017-12, “Derivatives and Hedging (Topic 815) - Targeted Improvements to Accounting for Hedging Activities” which amends the hedge accounting recognition and presentation requirements in ASC 815 to improve the transparency and understandability of information conveyed to financial statement users about an entity’s risk management activities to better align the entity’s financial reporting for hedging relationships with those risk management activities and to reduce the complexity of and simplify the application of hedge accounting. The Company adopted ASU 2017-12 on January 1, 2018 and it did not have a material impact on the Company’s financial condition or results of operations.

Summary of Accounting Policie36

Summary of Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Allocation of Sale Price to Assets Sold and Liabilities Transferred	The following table summarizes the allocation of the sale price to assets sold and liabilities transferred: (In thousands) 2015 Cash on hand $ 1,254 Loans 42,477 Premises and equipment 3,095 Other assets 113 Total assets sold 46,939 Deposits 253,823 Other liabilities 301 Total liabilities transferred 254,124 Cash paid $ 207,185
Summary of Loans Held for Sale	A summary of the loans held for sale at December 31, 2017 and 2016 is as follows: As of December 31, (In thousands) 2017 2016 Mortgage loans held for sale $ 5,834 $ 8,369 Commercial loans held for sale 55,525 9,453 Loans held for sale $ 61,359 $ 17,822

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Summary of Amortized Cost and Estimated Fair Value of Securities Available-for-Sale and Securities Held-to-Maturity	A summary of amortized cost and estimated fair value of securities available-for-sale and securities held-to-maturity at December 31, 2017 and 2016 is as follows: Gross Gross Amortized Unrealized Unrealized Estimated (In thousands) Cost Gains Losses Fair Value December 31, 2017 Securities available-for-sale: U.S. Treasury securities $ 100,575 $ — $ 3,731 $ 96,844 Obligations of U.S. government agencies 80,552 738 66 81,224 Mortgage-backed securities issued or guaranteed by U.S. agencies (MBS) Residential pass-through: Guaranteed by GNMA 106,461 676 1,110 106,027 Issued by FNMA and FHLMC 431,409 1,284 2,271 430,422 Other residential mortgage-backed securities 47,379 97 1,084 46,392 Commercial mortgage-backed securities 76,201 63 4,069 72,195 Total MBS 661,450 2,120 8,534 655,036 Obligations of states and municipal subdivisions 420,111 7,539 3,691 423,959 Other securities 5,762 286 163 5,885 Total securities available-for-sale $ 1,268,450 $ 10,683 $ 16,185 $ 1,262,948 Securities held-to-maturity: Obligations of states and municipal subdivisions $ 290 $ 21 $ — $ 311 (In thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value December 31, 2016 Securities available-for-sale: U.S. Treasury securities $ 100,736 $ — $ 3,951 $ 96,785 Obligations of U.S. government agencies 97,340 508 320 97,528 Mortgage-backed securities issued or guaranteed by U.S. agencies (MBS) Residential pass-through: Guaranteed by GNMA 152,918 1,401 1,166 153,153 Issued by FNMA and FHLMC 267,035 1,499 3,206 265,328 Other residential mortgage-backed securities 48,076 375 890 47,561 Commercial mortgage-backed securities 66,720 — 4,107 62,613 Total MBS 534,749 3,275 9,369 528,655 Obligations of states and municipal subdivisions 438,655 870 28,713 410,812 Other securities 5,580 149 162 5,567 Total securities available-for-sale $ 1,177,060 $ 4,802 $ 42,515 $ 1,139,347 Securities held-to-maturity: Obligations of states and municipal subdivisions $ 425 $ 38 $ — $ 463
Schedule of Contractual Maturities of Securities Available-for-Sale and Securities Held-to-Maturity	The scheduled contractual maturities of securities available-for-sale and securities held-to-maturity at December 31, 2017 were as follows: Available-for-Sale Held-to-Maturity Amortized Estimated Amortized Estimated (In thousands) Cost Fair Value Cost Fair Value Due in one year or less $ — $ — $ — $ — Due after one year through five years 108,378 104,719 290 311 Due after five years through ten years 19,397 19,653 — — Due after ten years 473,463 477,655 — — Mortgage-backed securities and other securities 667,212 660,921 — — Total $ 1,268,450 $ 1,262,948 $ 290 $ 311
Summary of Proceeds from Sales, Gross Gains, and Gross Losses on Sales of Securities Available for Sale	Proceeds from sales, gross gains, and gross losses on sales of securities available for sale for the years ended December 31, 2017, 2016 and 2015 are presented below. For the Years Ended December 31, (In thousands) 2017 2016 2015 Gross realized gains $ 167 $ 4,172 $ 1,444 Gross realized losses (313 ) (436 ) (273 ) Realized gains (losses) on sale of securities available for sale, net $ (146 ) $ 3,736 $ 1,171
Schedule of Securities Classified as Available-for-Sale with Unrealized Losses	The detail concerning securities classified as available-for-sale with unrealized losses as of December 31, 2017 and 2016 was as follows: Unrealized loss analysis Losses < 12 Months Losses > 12 Months Gross Gross Estimated Unrealized Estimated Unrealized (In thousands) Fair Value Losses Fair Value Losses December 31, 2017 U.S. Treasury securities $ — $ — $ 96,844 $ 3,731 Obligations of U.S. government agencies 1,577 9 14,323 57 MBS 306,274 1,490 172,324 7,044 Obligations of states and municipal subdivisions 2,601 22 134,870 3,669 Other securities — — 4,308 163 Total $ 310,452 $ 1,521 $ 422,669 $ 14,664 Unrealized loss analysis Losses < 12 Months Losses > 12 Months Gross Gross Estimated Unrealized Estimated Unrealized (In thousands) Fair Value Losses Fair Value Losses December 31, 2016 U.S. Treasury securities $ 96,785 $ 3,951 $ — $ — Obligations of U.S. government agencies 51,463 277 12,150 43 MBS 328,374 8,482 17,979 887 Obligations of states and municipal subdivisions 344,708 28,713 — — Other securities — — 4,216 162 Total $ 821,330 $ 41,423 $ 34,345 $ 1,092

Loans and Allowance for Credi38

Loans and Allowance for Credit Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Accounts Notes And Loans Receivable [Line Items]
Summary of Total Loans Outstanding by Portfolio Segment and Class of Financing Receivable	The following table presents total loans outstanding by portfolio segment and class of financing receivable as of December 31, 2017 and 2016, respectively. Outstanding balances include Acquired Noncredit Impaired (“ANCI”) loans, originated loans and Acquired Credit Impaired (“ACI”) loans. Information about ACI loans is presented separately in the “Acquired Credit-Impaired Loans” section of this Note. As of December 31, (In thousands) 2017 2016 Commercial and Industrial General C&I $ 2,746,454 $ 2,416,665 Energy sector 935,371 939,369 Restaurant industry 1,035,538 864,085 Healthcare 416,423 445,103 Total commercial and industrial 5,133,786 4,665,222 Commercial Real Estate Income producing 1,082,929 1,001,703 Land and development 75,472 71,004 Total commercial real estate 1,158,401 1,072,707 Consumer Residential real estate 1,690,814 1,457,170 Other 74,922 68,689 Total consumer 1,765,736 1,525,859 Small Business Lending 221,855 193,641 Total (Gross of unearned discount and fees) 8,279,778 7,457,429 Unearned discount and fees (26,351 ) (24,718 ) Total (Net of unearned discount and fees) $ 8,253,427 $ 7,432,711
Summary of Allowance for Credit Losses	A summary of the activity in the ACL for each of the three years in the period ended December 31, 2017 is as follows: For the Year Ended December 31, 2017 (In thousands) Commercial and Industrial Commercial Real Estate Consumer Small Business Total As of December 31, 2016 $ 54,688 $ 10,103 $ 13,265 $ 4,212 $ 82,268 Provision for loan losses 5,883 1,737 1,746 369 9,735 Charge-offs (5,645 ) (93 ) (929 ) (204 ) (6,871 ) Recoveries 993 243 901 307 2,444 As of December 31, 2017 $ 55,919 $ 11,990 $ 14,983 $ 4,684 $ 87,576 Allocation of ending ACL ACI loans collectively evaluated for impairment $ 5 $ 2,006 $ 6,289 $ — $ 8,300 ACI loans individually evaluated for impairment — 4 220 — 224 ANCI loans collectively evaluated for impairment 864 130 49 295 1,338 ANCI loans individually evaluated for impairment — — 36 22 58 Originated loans collectively evaluated for impairment 46,591 9,850 8,389 4,362 69,192 Originated loans individually evaluated for impairment 8,459 — — 5 8,464 ACL as of December 31, 2017 $ 55,919 $ 11,990 $ 14,983 $ 4,684 $ 87,576 Loans ACI loans collectively evaluated for impairment $ 19,486 $ 71,675 $ 150,798 $ — $ 241,959 ACI loans individually evaluated for impairment 10,091 8,186 324 — 18,601 ANCI loans collectively evaluated for impairment 58,775 15,926 113,357 11,331 199,389 ANCI loans individually evaluated for impairment — — 1,582 310 1,892 Originated loans collectively evaluated for impairment 4,974,973 1,062,614 1,499,260 209,627 7,746,474 Originated loans individually evaluated for impairment 70,461 — 415 587 71,463 Loans as of December 31, 2017 $ 5,133,786 $ 1,158,401 $ 1,765,736 $ 221,855 $ 8,279,778 For the Year Ended December 31, 2016 (In thousands) Commercial and Industrial Commercial Real Estate Consumer Small Business Total As of December 31, 2015 $ 55,824 $ 8,136 $ 13,450 $ 2,373 $ 79,783 Provision for loan losses 43,782 1,389 1,506 2,671 49,348 Charge-offs (46,367 ) — (2,094 ) (841 ) (49,302 ) Recoveries 1,449 578 403 9 2,439 As of December 31, 2016 $ 54,688 $ 10,103 $ 13,265 $ 4,212 $ 82,268 Allocation of ending ACL ACI loans collectively evaluated for impairment $ 176 $ 2,652 $ 7,215 $ — $ 10,043 ACI loans individually evaluated for impairment — 3 232 — 235 ANCI loans collectively evaluated for impairment 299 243 94 272 908 ANCI loans individually evaluated for impairment — — 37 33 70 Originated loans collectively evaluated for impairment 52,615 7,205 5,687 3,900 69,407 Originated loans individually evaluated for impairment 1,598 — — 7 1,605 ACL as of December 31, 2016 $ 54,688 $ 10,103 $ 13,265 $ 4,212 $ 82,268 Loans ACI loans collectively evaluated for impairment $ 26,276 $ 87,825 $ 187,668 $ — $ 301,769 ACI loans individually evaluated for impairment 11,772 10,345 396 — 22,513 ANCI loans collectively evaluated for impairment 51,694 20,306 151,759 8,769 232,528 ANCI loans individually evaluated for impairment — — 1,168 389 1,557 Originated loans collectively evaluated for impairment 4,424,822 954,231 1,184,442 183,933 6,747,428 Originated loans individually evaluated for impairment 150,658 — 426 550 151,634 Loans as of December 31, 2016 $ 4,665,222 $ 1,072,707 $ 1,525,859 $ 193,641 $ 7,457,429 For the Year Ended December 31, 2015 (In thousands) Commercial and Industrial Commercial Real Estate Consumer Small Business Total As of December 31, 2014 $ 28,930 $ 7,050 $ 15,552 $ 1,988 $ 53,520 Provision for loan losses 35,355 1,018 (1,412 ) 1,023 35,984 Charge-offs (8,525 ) (271 ) (1,291 ) (647 ) (10,734 ) Recoveries 64 339 601 9 1,013 As of December 31, 2015 $ 55,824 $ 8,136 $ 13,450 $ 2,373 $ 79,783 Allocation of ending ACL ACI loans collectively evaluated for impairment $ 2,062 $ 3,084 $ 8,688 $ — $ 13,834 ACI loans individually evaluated for impairment 168 — 332 — 500 ANCI loans collectively evaluated for impairment 425 227 65 285 1,002 ANCI loans individually evaluated for impairment — — 40 21 61 Originated loans collectively evaluated for impairment 48,666 4,825 4,325 2,067 59,883 Originated loans individually evaluated for impairment 4,503 — — — 4,503 ACL as of December 31, 2015 $ 55,824 $ 8,136 $ 13,450 $ 2,373 $ 79,783
Originated and Acquired Non Credit Impaired Loans
Accounts Notes And Loans Receivable [Line Items]
Summary of Impaired Loans	The following includes certain key information about individually impaired loans as of December 31, 2017 and 2016. Originated and ANCI Loans Identified as Impaired As of December 31, 2017 (In thousands) Recorded Investment in Impaired Loans (1) Unpaid Principal Balance Related Specific Allowance Nonaccrual Loans Included in Impaired Loans Undisbursed Commitments With no related allowance for credit losses Commercial and Industrial General C&I $ 5,010 $ 4,994 $ — $ 192 $ — Energy sector 14,822 23,307 — 14,822 387 Total commercial and industrial 19,832 28,301 — 15,014 387 Consumer Residential real estate 1,093 1,097 — 35 — Other 416 415 — — — Total consumer 1,509 1,512 — 35 — Small Business Lending 249 695 — 249 — Total $ 21,590 $ 30,508 $ — $ 15,298 $ 387 With allowance for credit losses recorded Commercial and Industrial Energy sector $ 39,857 $ 43,416 $ 8,353 $ 28,000 $ 402 Restaurant industry 11,017 10,969 106 — 2,500 Total commercial and industrial 50,874 54,385 8,459 28,000 2,902 Consumer Residential real estate 496 494 36 — — Small Business Lending 650 921 27 60 — Total $ 52,020 $ 55,800 $ 8,522 $ 28,060 $ 2,902 As of December 31, 2016 (In thousands) Recorded Investment in Impaired Loans (1) Unpaid Principal Balance Related Specific Allowance Nonaccrual Loans Included in Impaired Loans Undisbursed Commitments With no related allowance for credit losses Commercial and Industrial General C&I $ 12,334 $ 13,426 $ — $ 6,838 $ 1,363 Energy sector 99,200 103,322 — 85,149 8,465 Total commercial and industrial 111,534 116,748 — 91,987 9,828 Consumer Residential real estate 437 435 — — — Other 429 427 — — 1 Total consumer 866 862 — — 1 Small Business Lending 299 703 — 299 — Total $ 112,699 $ 118,313 $ — $ 92,286 $ 9,829 With allowance for credit losses recorded Commercial and Industrial Energy sector $ 39,319 $ 45,243 $ 1,598 $ 28,228 $ 4,788 Consumer Residential real estate 736 741 37 39 — Small Business Lending 641 897 40 90 — Total $ 40,696 $ 46,881 $ 1,675 $ 28,357 $ 4,788 (1) The recorded investment of a loan also includes any interest receivable, net unearned discount or fees, and unamortized premium or discount. The related amount of interest income recognized for impaired loans was $1.6 million for the year ended December 31, 2017, compared to $1.4 million and $0.8 million for the same periods in 2016 and 2015, respectively. Generally, cash receipts on nonperforming loans are used to reduce principal rather than recorded as interest income. Past due status is determined based upon contractual terms. A nonaccrual loan may be returned to accrual status when repayment is reasonably assured and there has been demonstrated performance under the terms of the loan or, if applicable, under the terms of the restructured loan. Approximately $1.5 million of contractual interest paid was recognized on the cash basis for the year ended December 31, 2017, compared to $1.1 million and zero for same periods in 2016 and 2015, respectively.
Summary of Average Recorded Investment in Impaired Originated and ANCI Loans	Average Recorded Investment in Impaired Originated and ANCI Loans Year Ended December 31, (In thousands) 2017 2016 2015 Commercial and Industrial General C&I $ 8,586 $ 11,291 $ 6,347 Energy sector 108,751 158,192 20,105 Restaurant industry 2,203 — — Total commercial and industrial 119,540 169,483 26,452 Consumer Residential real estate 1,426 1,206 1,567 Other 386 398 273 Total consumer 1,812 1,604 1,840 Small Business Lending 945 547 723 Total $ 122,297 $ 171,634 $ 29,015
Summary of Originated and ANCI Loans that were modified into TDRs	Originated and ANCI Loans that were modified into TDRs For the Year Ended December 31, 2017 2016 2015 (In thousands) Number of TDRs Recorded Investment Number of TDRs Recorded Investment Number of TDRs Recorded Investment Commercial and Industrial 3 $ 16,027 6 $ 43,609 5 $ 26,459 Consumer 2 739 2 534 6 579 Small Business Lending 1 138 1 552 — — Total 6 $ 16,904 9 $ 44,695 11 $ 27,038 For the Year Ended December 31, 2017 2016 2015 Number of Loans Modified by: Rate Concession Modified Terms and/ or Other Concessions Forbearance Agreement Rate Concession Modified Terms and/ or Other Concessions Rate Concession Modified Terms and/ or Other Concessions Commercial and Industrial 2 1 2 1 3 — 5 Consumer — 2 — — 2 5 1 Small Business Lending 1 — — 1 — — — Total 3 3 2 2 5 5 6
Summary of Credit Exposure by Portfolio Segment and Class of Receivable	The following provides information regarding the credit exposure by portfolio segment and class of receivable as of December 31, 2017 and 2016: As of December 31, 2017 (Recorded Investment in thousands) Special Mention Substandard Doubtful Total Criticized / Classified Commercial and Industrial General C&I $ 80,550 $ 47,324 $ — $ 127,874 Energy sector — 99,979 7,634 107,613 Restaurant industry 4,536 12,506 — 17,042 Healthcare — 71 — 71 Total commercial and industrial 85,086 159,880 7,634 252,600 Commercial Real Estate Income producing — 26 — 26 Land and development 20 — — 20 Total commercial real estate 20 26 — 46 Consumer Residential real estate 7,610 12,416 — 20,026 Other 673 356 4 1,033 Total consumer 8,283 12,772 4 21,059 Small Business Lending 3,480 1,375 27 4,882 Total $ 96,869 $ 174,053 $ 7,665 $ 278,587 As of December 31, 2016 (Recorded Investment in thousands) Special Mention Substandard Doubtful Total Criticized / Classified Commercial and Industrial General C&I $ 36,419 $ 27,489 $ — $ 63,908 Energy sector 30,433 239,457 789 270,679 Restaurant industry 16,169 — — 16,169 Healthcare 9,479 — — 9,479 Total commercial and industrial 92,500 266,946 789 360,235 Commercial Real Estate Income producing — — — — Land and development 23 341 — 364 Total commercial real estate 23 341 — 364 Consumer Residential real estate 2,578 3,871 — 6,449 Other 508 419 — 927 Total consumer 3,086 4,290 — 7,376 Small Business Lending 1,818 1,880 — 3,698 Total $ 97,427 $ 273,457 $ 789 $ 371,673
Past Due Financing Receivables	The following provides an aging of past due loans by portfolio segment and class of receivable as of December 31, 2017 and 2016: Aging of Past Due Originated and ANCI Loans As of December 31, 2017 Accruing Loans Non-Accruing Loans (Recorded Investment in thousands) 30-59 DPD 60-89 DPD 90+DPD 0-29 DPD 30-59 DPD 60-89 DPD 90+DPD Commercial and Industrial General C&I $ 59 $ — $ 476 $ — $ 192 $ — $ — Energy sector — — — 32,315 — — 10,507 Healthcare — — — — 71 — - Total commercial and industrial 59 — 476 32,315 263 — 10,507 Commercial Real Estate Income producing — — 26 — — — — Land and development 55 — — — — — — Total commercial real estate 55 — 26 — — — — Consumer Residential real estate 3,191 1,030 325 1,070 173 293 2,205 Other 532 3 — — — — — Total consumer 3,723 1,033 325 1,070 173 293 2,205 Small Business Lending 931 328 — 110 38 — 494 Total $ 4,768 $ 1,361 $ 827 $ 33,495 $ 474 $ 293 $ 13,206 As of December 31, 2016 Accruing Loans Non-Accruing Loans (Recorded Investment in thousands) 30-59 DPD 60-89 DPD 90+DPD 0-29 DPD 30-59 DPD 60-89 DPD 90+DPD Commercial and Industrial General C&I $ 3,930 $ — $ — $ 125 $ 6,839 $ — $ 250 Energy sector — — — 112,937 — — 447 Total commercial and industrial 3,930 — — 113,062 6,839 — 697 Commercial Real Estate Income producing 4 — — — — — — Land and development 259 — — — — 341 — Total commercial and industrial 263 — — — — 341 — Consumer Residential real estate 2,910 1,078 496 1,427 30 — 2,073 Other 552 — 3 — — — — Total consumer 3,462 1,078 499 1,427 30 — 2,073 Small Business Lending 2,003 563 87 560 78 36 131 Total $ 9,658 $ 1,641 $ 586 $ 115,049 $ 6,947 $ 377 $ 2,901
ACI Loans
Accounts Notes And Loans Receivable [Line Items]
Summary of Total Loans Outstanding by Portfolio Segment and Class of Financing Receivable	The following table presents total ACI loans outstanding by portfolio segment and class of financing receivable as of December 31, 2017 and 2016. As of December 31, (In thousands) 2017 2016 Commercial and Industrial General C&I $ 23,428 $ 31,709 Healthcare 6,149 6,338 Total commercial and industrial 29,577 38,047 Commercial Real Estate Income producing 79,861 96,673 Land and development — 1,497 Total commercial real estate 79,861 98,170 Consumer Residential real estate 149,942 186,375 Other 1,180 1,690 Total consumer 151,122 188,065 Total $ 260,560 $ 324,282
Summary of Credit Exposure by Portfolio Segment and Class of Receivable	The following provides information regarding the credit exposure by portfolio segment and class of receivable as of December 31, 2017 and December 31, 2016: ACI Loans by Risk Rating As of December 31, 2017 2016 (Recorded Investment in thousands) Special Mention Substandard Doubtful Special Mention Substandard Doubtful Commercial and Industrial General C&I $ 737 $ 1,173 $ 37 $ 939 $ 5,484 $ 33 Healthcare — 6,148 — — — — Total commercial and industrial 737 7,321 37 939 5,484 33 Commercial Real Estate Income producing 1,446 4,425 — 5,813 13,591 — Land and development 733 2,090 — 933 3,240 — Total commercial real estate 2,179 6,515 — 6,746 16,831 — Consumer Residential real estate 3,900 22,635 — 3,655 27,586 — Other 114 417 — 14 287 — Total consumer 4,014 23,052 — 3,669 27,873 — Total $ 6,930 $ 36,888 $ 37 $ 11,354 $ 50,188 $ 33
Past Due Financing Receivables	ACI Consumer credit exposure, based on past due status: As of December 31, 2017 2016 (Recorded Investment in thousands) Residential Real Estate Other Residential Real Estate Other 0 – 29 Days Past Due $ 139,662 $ 1,356 $ 171,457 $ 1,871 30 – 59 Days Past Due 2,299 120 4,070 134 60 – 89 Days Past Due 2,496 62 1,939 25 90 – 119 Days Past Due 399 — 622 36 120 + Days Past Due 7,480 45 10,915 56 Total $ 152,336 $ 1,583 $ 189,003 $ 2,122
Summary of Changes in Accretable Discount for ACI Loans	Changes in the amount of accretable discount for ACI loans for each of the years in the period ended December 31, 2017: Changes in Accretable Yield on ACI Loans For the Year Ended December 31, (In thousands) 2017 2016 2015 Balance at beginning of period $ 98,728 $ 122,791 $ 163,631 Maturities/payoff (9,888 ) (11,563 ) (24,196 ) Charge-offs (129 ) (286 ) (183 ) Foreclosure (1,061 ) (1,041 ) (1,290 ) Accretion (23,303 ) (30,870 ) (46,042 ) Reclass from nonaccretable difference due to increases in expected cash flow 14,075 19,697 30,871 Balance at end of period $ 78,422 $ 98,728 $ 122,791
Summary of Individually Impaired ACI Loans and Pooled ACI Loans	The following includes certain key information about individually impaired ACI loans and pooled ACI loans as of and for the years ended December 31, 2017 and 2016. ACI Loans / Pools Identified as Impaired As of December 31, 2017 ACI Loans / Pools Identified as Impaired (In thousands) Recorded Investment in Impaired Loans (1) Unpaid Principal Balance Related Specific Allowance Nonaccrual Loans Included in Impaired Loans Undisbursed Commitments Commercial and Industrial $ 13,541 $ 17,630 $ 5 $ — $ — Commercial Real Estate 82,856 112,330 2,010 225 — Consumer 18,603 22,064 6,509 — — Total $ 115,000 $ 152,024 $ 8,524 $ 225 $ — As of December 31, 2016 ACI Loans / Pools Identified as Impaired (In thousands) Recorded Investment in Impaired Loans (1) Unpaid Principal Balance Related Specific Allowance Nonaccrual Loans Included in Impaired Loans Undisbursed Commitments Commercial and Industrial $ 15,552 $ 28,256 $ 176 $ 1,818 $ — Commercial Real Estate 53,428 82,946 2,654 1,845 1,213 Consumer 44,295 50,175 7,447 — 15 Total $ 113,275 $ 161,377 $ 10,277 $ 3,663 $ 1,228 (1) The recorded investment of a loan also includes any interest receivable, net unearned discount or fees, and unamortized premium or discount.

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Components of Premises and Equipment	Premises and equipment are stated at cost, less accumulated depreciation and amortization, as follows: December 31, (In thousands) Estimated Useful Life in Years 2017 2016 Premises: Land — $ 16,875 $ 16,875 Buildings, construction and improvements (1) 2-40 53,620 52,263 Total premises 70,495 69,138 Equipment 3-10 34,123 31,984 Total premises and equipment 104,618 101,122 Less: Accumulated depreciation and amortization (41,186 ) (34,446 ) Total premises and equipment, net $ 63,432 $ 66,676 (1) Leasehold improvements are depreciated over the lesser of the estimated useful life or the lease term.
Future Minimum Lease Payments under Operating Leases	The following is a schedule by year of future minimum lease payments under operating leases, as of December 31, 2017: Year Property Equipment Total (In thousands) 2018 $ 9,724 $ 342 $ 10,066 2019 9,542 187 9,729 2020 8,544 44 8,588 2021 7,794 — 7,794 2022 5,575 — 5,575 Thereafter 8,949 — 8,949 Total minimum lease payments $ 50,128 $ 573 $ 50,701

Goodwill and Other Intangible40

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Goodwill and Other Intangible Assets	The following table summarizes the Company’s goodwill and other intangible assets at December 31, 2017 and 2016: December 31, (In thousands) 2017 2016 Goodwill $ 317,817 $ 317,817 Core deposit intangible, net of accumulated amortization of $38,091 and $35,495, respectively 1,595 4,191 Customer lists, net of accumulated amortization of $18,097 and $16,041, respectively 8,604 10,659 Trademarks 24 24 Total goodwill and intangible assets $ 328,040 $ 332,691

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts and Estimated Fair Values	The notional amounts and estimated fair values as of December 31, 2017 and 2016 were as follows: December 31, 2017 December 31, 2016 Fair Value Fair Value (In thousands) Notional Amount Other Assets Other Liabilities Notional Amount Other Assets Other Liabilities Derivatives designated as hedging instruments (cash flow hedges): Commercial loan interest rate swaps $ 1,032,000 $ — $ 21,394 $ 1,332,000 $ 1,184 $ 17,225 Derivatives not designated as hedging instruments: Commercial loan interest rate swaps 737,533 2,056 2,056 474,923 2,877 2,877 Commercial loan interest rate caps 186,290 153 153 286,959 94 94 Commercial loan interest rate floors 330,764 1,054 1,054 51,878 118 118 Mortgage loan held for sale interest rate lock commitments 6,119 50 — 3,788 88 — Mortgage loan forward sale commitments 4,565 10 — 7,724 — 46 Mortgage loan held for sale floating commitments 11,800 — — 5,895 — — Foreign exchange contracts 41,688 635 623 — — — Total derivatives not designated as hedging instruments 1,318,759 3,958 3,886 831,167 3,177 3,135 Total derivatives $ 2,350,759 $ 3,958 $ 25,280 $ 2,163,167 $ 4,361 $ 20,360
Schedule of Gain (Loss) in Consolidated Statements of Income Related to Derivative Instruments	Gain (loss) included in the consolidated statements of income related to derivative instruments for each of the three years ended December 31, 2017: For the Year Ended December 31, 2017 2016 2015 (In thousands) OCI Reclassified from AOCI to interest income Noninterest income OCI Reclassified from AOCI to interest income Noninterest income OCI Reclassified from AOCI to interest income Noninterest income Derivatives designated as hedging instruments (cash flow hedges): Commercial loan interest rate swaps $ (1,426 ) $ 3,705 $ — $ (7,444 ) $ 11,255 $ 166 $ 7,454 $ 4,877 $ (329 ) Derivatives not designated as hedging instruments: Mortgage loan held for sale interest rate lock commitments $ — $ — $ (39 ) $ — $ — $ 24 $ — $ — $ (66 ) Foreign exchange contracts — — 2,271 — — 1,264 — — 965
Schedule of Interest Rate Swap Agreements	In June 2015 and March 2016, the Company entered into the following interest rate swap agreements to manage overall cash flow changes related to interest rate risk exposure on benchmark interest rate loans. On December 29, 2017, an interest rate swap agreement matured with a notional amount of $300 million. Effective Date Maturity Date Notional Amount (In Thousands) Fixed Rate Variable Rate June 15, 2015 December 17, 2018 $ 382,000 1.3250 % 1 Month LIBOR June 30, 2015 December 31, 2019 300,000 1.5120 1 Month LIBOR March 8, 2016 February 27, 2026 175,000 1.5995 1 Month LIBOR March 8, 2016 February 27, 2026 175,000 1.5890 1 Month LIBOR

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Banking And Thrift [Abstract]
Scheduled Maturities of Time Deposits Included in Interest-Bearing Deposits	At December 31, 2017, the scheduled maturities of time deposits included in interest-bearing deposits were as follows. (In thousands) December 31, 2017 2018 $ 1,284,285 2019 515,511 2020 89,364 2021 16,678 2022 10,455 Thereafter 44 Total $ 1,916,337

Borrowed Funds (Tables)

Borrowed Funds (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Summary of Securities Sold Under Agreements to Repurchase	Information concerning the Company’s securities sold under agreements to repurchase as of December 31, 2017 and 2016 is summarized as follows: December 31, (In thousands) 2017 2016 Balance at period end $ 1,026 $ 3,494 Average balance during the period 3,371 5,948 Average interest rate during the period 0.25 % 0.19 % Maximum month-end balance during the period $ 6,286 $ 8,031
Summary of Debt	Details of the debt transactions are as follows: December 31, (In thousands) 2017 2016 Cadence Bancorporation: 4.875% senior notes, due June 28, 2019 $ 145,000 $ 145,000 5.375% senior notes, due June 28, 2021 50,000 50,000 7.250% subordinated notes, due June 28, 2029, callable in 2024 35,000 35,000 6.500% subordinated notes, due March 2025, callable in 2020 40,000 40,000 Total long-term debt—Cadence Bancorporation 270,000 270,000 Cadence Bank: 6.250% subordinated notes, due June 28, 2029, callable in 2024 25,000 25,000 Debt issuance cost and unamortized premium (1,606 ) (2,693 ) Purchased 4.875% senior notes, due June 28, 2019 (10,078 ) (78 ) Total long-term debt $ 283,316 $ 292,229
Summary of Junior Subordinated Debt	The following is a list of junior subordinated debt: December 31, (In thousands) 2017 2016 Junior subordinated debentures, 3 month LIBOR plus 2.85%, due 2033 $ 30,000 $ 30,000 Junior subordinated debentures, 3 month LIBOR plus 2.95%, due 2033 5,155 5,155 Junior subordinated debentures, 3 month LIBOR plus 1.75%, due 2037 15,464 15,464 Total par value $ 50,619 $ 50,619 Purchase accounting adjustment, net of amortization (14,147 ) (14,630 ) Total junior subordinated debentures $ 36,472 $ 35,989

Other Noninterest Income and 44

Other Noninterest Income and Other Noninterest Expense (Tables)	12 Months Ended
	Dec. 31, 2017
Other Nonoperating Income Expense [Abstract]
Summary of Other Noninterest Income and Other Noninterest Expense	The detail of the other noninterest income and other noninterest expense captions presented in the consolidated statements of income is as follows: For the Year Ended December 31, (In thousands) 2017 2016 2015 Other noninterest income Insurance revenue $ 7,378 $ 7,717 $ 7,107 Bankcard fees 7,310 7,270 7,213 Income from bank owned life insurance policies 3,313 2,954 2,994 Other 6,655 (263 ) (2,297 ) Total other noninterest income $ 24,656 $ 17,678 $ 15,017 For the Year Ended December 31, (In thousands) 2017 2016 2015 Other noninterest expense Net cost of operation of other real estate owned $ 2,251 $ 3,033 $ 5,238 Data processing expense 7,590 6,280 6,092 Special asset expenses 1,156 1,788 3,000 Consulting and professional fees 9,090 6,728 5,671 Loan related expenses 2,379 3,114 3,745 FDIC insurance 4,275 7,228 5,027 Communications 2,837 2,656 3,249 Advertising and public relations 2,048 1,369 2,295 Legal expenses 4,178 2,721 3,159 Branch closure expenses 198 238 2,074 Other 24,663 25,443 26,306 Total other noninterest expense $ 60,665 $ 60,598 $ 65,856

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Components of the Consolidated Income Tax Expense	The components of the consolidated income tax expense are as follows: For the Year Ended December 31, (In thousands) 2017 2016 2015 Current: Federal $ 33,799 $ 24,394 $ 22,024 State 2,458 2,166 1,013 Total current expense 36,257 26,560 23,037 Deferred: Federal 44,009 5,439 (3,266 ) State 380 541 338 Total deferred (benefit) expense 44,389 5,980 (2,928 ) Total income tax expense $ 80,646 $ 32,540 $ 20,109
Reconciliation of Total Income Tax Expense	A reconciliation of total income tax expense for each of the years in the period ended December 31 2017 to amounts determined by applying the statutory Federal income tax rate of 35% to income before taxes is as follows: For the Year Ended December 31, (In thousands) 2017 2016 2015 Computed income tax expense at statutory rate $ 64,050 $ 34,410 $ 20,778 Effects of tax reform 19,022 — — Tax exempt interest, net (3,988 ) (2,744 ) (842 ) BOLI income (1,148 ) (1,023 ) (1,037 ) State tax expense 2,279 1,760 878 Tax credits (384 ) (266 ) (243 ) Management compensation 116 210 353 Other, net 699 193 222 Total income tax expense $ 80,646 $ 32,540 $ 20,109
Significant Components of the Company's Deferred Tax Assets and Liabilities	The significant components of the Company’s deferred tax assets and liabilities as of December 31, 2017 and 2016 are as follows: As of December 31, (In thousands) 2017 2016 Deferred income tax assets: Allowance for credit losses $ 18,464 $ 30,710 Nonaccrual interest — 7,410 Deferred compensation 3,440 3,681 Accrued compensation 2,506 7,962 Net operating loss carryforwards 9,859 16,154 Alternative minimum tax credit carryover 978 978 Unrealized loss on securities, net 1,271 13,829 Unrealized loss on derivative instruments 4,912 5,911 Other 5,344 9,320 Excess of tax basis in assets acquired: Loans 841 8,673 Other real estate owned 13 1,342 Other — 4 Total deferred income tax assets 47,628 105,974 Deferred income tax liabilities: Difference in book and tax basis of intangibles 1,927 4,268 Other 4,213 4,564 Excess of book basis in assets acquired and tax liabilities assumed over book carrying value: Intangibles 7,122 7,798 Other 3,592 5,682 Total deferred income tax liabilities 16,854 22,312 Net deferred income tax asset $ 30,774 $ 83,662
Reconciliation of the Beginning and Ending Amount of Unrecognized Income Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized income tax benefits is as follows (unrecognized state income tax benefits are not adjusted for the federal income tax impact): For the Year Ended December 31, (In thousands) 2017 2016 2015 Unrecognized income tax benefits, January 1 $ 944 $ — $ — Increases for tax positions related to: Prior years 9 422 — Current year 394 522 — Decreases for tax positions related to: Prior years (453 ) — — Current year — — — Settlement with taxing authorities — — — Expiration of applicable statutes of limitations — — — Unrecognized income tax benefits, December 31 $ 894 $ 944 $ —

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Reconciliation of Basic and Diluted Net Income Per Common Share	The following table displays a reconciliation of the information used in calculating basic and diluted net income per common share for each of the years in the period ended December 31, 2017. For the Years Ended December 31, (In thousands, except per share data) 2017 2016 2015 Net income $ 102,353 $ 65,774 $ 39,256 Weighted average common shares outstanding (Basic) 81,072,945 75,000,000 75,000,000 Weighted average restricted stock units 532,070 294,600 116,100 Weighted average common shares outstanding (Diluted) 81,605,015 75,294,600 75,116,100 Earnings per common share (Basic) $ 1.26 $ 0.88 $ 0.52 Earnings per common share (Diluted) $ 1.25 $ 0.87 $ 0.52

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined benefit pension plan funded	The following table sets forth the defined benefit pension plan’s funded status as of December 31, 2017 and 2016 and amounts recognized in the Company’s consolidated financial statements for each of the years in the period ended December 31, 2017: (In thousands) 2017 2016 Change in benefit obligation: Benefit obligation at beginning of period $ 5,785 $ 6,176 Service cost 100 100 Interest cost 192 221 Actuarial loss 224 233 Administrative expenses paid (40 ) (59 ) Benefits paid (77 ) (79 ) Settlements (275 ) (807 ) Benefit obligation at end of year 5,909 5,785 Change in plan assets: Fair value of plan assets at beginning of period 4,689 4,464 Return on plan assets 533 240 Employer contributions 1,300 930 Administrative expenses paid (40 ) (59 ) Benefits paid (77 ) (79 ) Settlements (275 ) (807 ) Fair value of plan assets at end of year 6,130 4,689 Funded status $ 221 $ (1,096 ) (In thousands) 2017 2016 2015 Components of net periodic benefit cost: Service cost $ 100 $ 100 $ 100 Interest cost 192 221 232 Expected return on plan assets (261 ) (234 ) (278 ) Net loss amortization 65 53 61 Cost of settlements 45 156 155 Net periodic benefit cost $ 141 $ 296 $ 270 Amount recognized in accumulated other comprehensive income: Amortization of net actuarial loss $ 65 $ 53 $ 61 Net actuarial loss 48 (226 ) (35 ) Adjustment for settlement 45 156 155 Gains (losses) on pension liability 158 (17 ) 181 Tax effect (37 ) 4 (69 ) Net unrealized (losses) gains on pension liability $ 121 $ (13 ) $ 112
Assumptions Used to Determine Benefit Obligations and Net Periodic Pension Cost	2017 2016 2015 Weighted average assumptions used to determine benefit obligations and net periodic pension cost at December 31: Discount rate 3.21 % 3.52 % 3.76 % Compensation increase rate N/A N/A N/A Census date 1/1/2018 1/1/2017 1/1/2016 Expected return on plan assets 5.50 % 5.50 % 5.50 %
Schedule of Defined Benefit Pension Plan Fair Values and Weighted-Average Asset Allocations by Asset Category	The Company’s defined benefit pension plan fair values and weighted-average asset allocations at December 31, 2017 and 2016, by asset category, were as follows: 2017 2016 (In thousands) Fair Value of Plan Assets Asset Allocations Fair Value of Plan Assets Asset Allocations Asset Category: Equity securities $ 2,382 39 % $ 1,912 41 % Fixed income securities 3,342 55 2,594 55 Other securities — — 183 4 Cash and cash equivalents 406 6 — — Total $ 6,130 100 % $ 4,689 100 %
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Expected Benefit Payments	Retiree benefit payments, which reflect expected future service, are anticipated to be paid as follows: Amount Year (In thousands) 2018 $ 823 2019 514 2020 734 2021 1,019 2022 370 2023-2027 1,830 Total $ 5,290
Other Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Expected Benefit Payments	Projected benefit payments under these plans are anticipated to be paid as follows: Year Amount (In thousands) 2018 $ 171 2019 375 2020 376 2021 384 2022 451 2023-2027 2,299 Total $ 4,056

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2017
Banking And Thrift [Abstract]
Schedule of Actual Capital Amounts and Ratios	The actual capital amounts and ratios for the Company and the bank as of December 31, 2017 and 2016 are presented in the following table and as shown, are above the thresholds necessary to be considered “well-capitalized”. Management believes there are no conditions or events that would change that classification in the foreseeable future. Consolidated Company Bank (In thousands) Amount Ratio Amount Ratio December 31, 2017 Tier 1 leverage $ 1,096,438 10.7 % $ 1,198,234 11.7 % Common equity tier 1 capital (transitional) 1,058,888 10.6 1,149,181 11.5 Tier 1 risk-based capital 1,096,438 10.9 1,198,234 12.0 Total risk-based capital 1,283,561 12.8 1,311,376 13.1 The minimum amounts of capital and ratios established by banking regulators are as follows: Tier 1 leverage $ 410,770 4.0 % $ 410,743 4.0 % Common equity tier 1 capital (transitional) 450,951 4.5 450,874 4.5 Tier 1 risk-based capital 601,269 6.0 601,165 6.0 Total risk-based capital 801,691 8.0 801,553 8.0 Well capitalized requirement: Tier 1 leverage N/A N/A $ 513,429 5.0 % Common equity tier 1 capital (transitional) N/A N/A 651,262 6.5 Tier 1 risk-based capital N/A N/A 801,553 8.0 Total risk-based capital N/A N/A 1,001,941 10.0 Consolidated Company Bank (In thousands) Amount Amount Amount Ratio December 31, 2016 Tier 1 leverage $ 824,676 8.9 % $ 1,035,972 11.2 % Common equity tier 1 (CET1) 793,268 8.8 989,990 11.0 Tier 1 risk-based capital 824,676 9.2 1,035,972 11.5 Total risk-based capital 1,007,011 11.2 1,144,519 12.8 The minimum amounts of capital and ratios established by banking regulators are as follows: Tier 1 leverage $ 371,052 4.0 % $ 370,836 4.0 % Common equity tier 1 (CET1) 403,718 4.5 403,578 4.5 Tier 1 risk-based capital 538,290 6.0 538,105 6.0 Total risk-based capital 717,720 8.0 717,473 8.0 Well capitalized requirement: Tier 1 leverage N/A N/A $ 463,546 5.0 % Common equity tier 1 (CET1) N/A N/A 583,248 6.5 Tier 1 risk-based capital N/A N/A 717,844 8.0 Total risk-based capital N/A N/A 897,305 10.0

Commitments and Contingent Li49

Commitments and Contingent Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Summary of Commitments and Contingent Liabilities	A summary of commitments and contingent liabilities at December 31, 2017 is as follows: As of December 31, (In thousands) 2017 2016 Commitments to extend credit $ 3,270,097 $ 2,643,501 Standby letters of credit 101,718 120,532 Performance letters of credit 17,638 29,270 Commercial letters of credit 11,790 —

Supplemental Cash Flow Inform50

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2017
Supplemental Cash Flow Elements [Abstract]
Summary of Supplemental Cash Flow Information	For the Years Ended December 31, (In thousands) 2017 2016 2015 Cash paid during the year for: Interest $ 69,289 $ 55,086 $ 44,333 Income taxes, net of refunds 33,268 23,025 22,139 Non-cash investing activities (at fair value): Transfers of loans to other real estate $ 7,023 $ 13,494 $ 11,800 Transfers of commercial loans to loans held for sale 16,206 318,868 19,400 Transfers of loans to other assets (net profits interest) — 19,104 —

Disclosure About Fair Values 51

Disclosure About Fair Values of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis	The table below presents the Company’s assets and liabilities measured at fair value on a recurring basis categorized by the level of inputs used in the valuation of each asset at December 31, 2017 and 2016: (In thousands) Carrying Value (Level 1) (Level 2) (Level 3) December 31, 2017 Investment securities available-for-sale: U.S. Treasury securities $ 96,844 $ — $ 96,844 $ — Obligations of U.S. government agencies 81,224 — 81,224 — Mortgage-backed securities issued or guaranteed by U.S. agencies (MBS) Residential pass-through: Guaranteed by GNMA 106,027 — 106,027 — Issued by FNMA and FHLMC 430,422 — 430,422 — Other residential mortgage-backed securities 46,392 — 46,392 — Commercial mortgage-backed securities 72,195 — 72,195 — Total MBS 655,036 — 655,036 — Obligations of states and municipal subdivisions 423,959 — 423,959 Other securities 5,885 5,885 — — Total investment securities available-for-sale 1,262,948 5,885 1,257,063 — Derivative assets 3,985 — 3,985 — Other assets (Net profits interests) 15,833 — — 15,833 Total recurring basis measured assets $ 1,282,766 $ 5,885 $ 1,261,048 $ 15,833 Derivative liabilities $ 25,307 $ — $ 25,307 $ — Total recurring basis measured liabilities $ 25,307 $ — $ 25,307 $ — (In thousands) Carrying Value (Level 1) (Level 2) (Level 3) December 31, 2016 Investment securities available-for-sale: U.S. Treasury securities $ 96,785 $ — $ 96,785 $ — Obligations of U.S. government agencies 97,528 — 97,528 — Mortgage-backed securities issued or guaranteed by U.S. agencies (MBS) Residential pass-through: Guaranteed by GNMA 153,153 — 153,153 — Issued by FNMA and FHLMC 265,328 — 265,328 — Other residential mortgage-backed securities 47,561 — 47,561 — Commercial mortgage-backed securities 62,613 — 62,613 — Total MBS 528,655 — 528,655 — Obligations of states and municipal subdivisions 410,812 — 410,812 — Other securities 5,567 5,567 — — Total investment securities available-for-sale 1,139,347 5,567 1,133,780 — Derivative assets 4,361 — 4,361 — Other assets (Net profits interest) 19,425 — — 19,425 Total recurring basis measured assets $ 1,163,133 $ 5,567 $ 1,138,141 $ 19,425 Derivative liabilities $ 20,360 $ — $ 20,360 $ — Total recurring basis measured liabilities $ 20,360 $ — $ 20,360 $ —
Summary of Changes in Level 3 Assets Measured at Fair Value on a Recurring Basis	The table below includes a roll-forward of the consolidated balance sheet amounts for each of the years in the period ended December 31, 2017 Level 3 Assets Measured at Fair Value on a Recurring Basis Other Assets - Net Profits Interests For the Years Ended December 31, (In thousands) 2017 2016 2015 Beginning Balance $ 19,425 $ — $ — Addition of net profits interest to other assets — 19,104 — Total net gains (losses) included in earnings (2,442 ) 407 — Distributions received (1,150 ) (86 ) — Balance at December 31 $ 15,833 $ 19,425 $ — Net unrealized (losses) gains included in earnings relating to assets held at the end of the period $ (2,442 ) $ 407 $ —
Summary of Assets Recorded at Fair Value on a Nonrecurring Basis	From time to time, the Company may be required to measure certain other financial assets at fair value on a nonrecurring basis in accordance with GAAP. These adjustments to fair value usually result from the application of lower of cost or fair value accounting or write-downs of individual assets. For assets measured at fair value on a nonrecurring basis which were still held on the balance sheets at December 31, 2017 and 2016, the following tables provide the level of valuation assumptions used to determine each adjustment and the related carrying value: (In thousands) Carrying Value (Level 1) (Level 2) (Level 3) December 31, 2017 Loans held for sale $ 61,359 $ — $ 61,359 $ — Impaired loans, net of specific allowance 65,087 — — 65,087 Other real estate 7,605 — — 7,605 Total assets measured on a nonrecurring basis $ 134,051 $ — $ 61,359 $ 72,692 (In thousands) Carrying Value (Level 1) (Level 2) (Level 3) December 31, 2016 Loans held for sale $ 17,822 $ — $ 17,822 $ — Impaired loans, net of specific allowance 151,720 — — 151,720 Other real estate 18,875 — — 18,875 Total assets measured on a nonrecurring basis $ 188,417 $ — $ 17,822 $ 170,595
Summary of Significant Unobservable Inputs Used in Level 3 Fair Value Measurements for Financial Assets Measured at Fair Value on a Nonrecurring Basis	Significant unobservable inputs used in Level 3 fair value measurements for financial assets measured at fair value on a nonrecurring basis at December 31, 2017 and 2016 are summarized below: Quantitative Information about Level 3 Fair Value Measurements (In thousands) Carrying Value Valuation Methods Unobservable Inputs Range December 31, 2017 Impaired loans, net of specific allowance $ 65,087 Appraised value, as adjusted Discount to fair value 0% - 50% Discounted cash flow Net recoverable oil and gas reserves and forward-looking commodity prices. Discount rate - 9% 0% - 29% (1) Discounted cash flow Discount rates - 3.6% to 8.0% 0% - 1% (1) Estimated closing costs 10% Other real estate 7,605 Appraised value, as adjusted Discount to fair value 0% - 20% Estimated closing costs 10% (1) - Represents fair value as a percent of the unpaid principal balance. Quantitative Information about Level 3 Fair Value Measurements (In thousands) Carrying Value Valuation Methods Unobservable Inputs Range December 31, 2016 Impaired loans, net of specific allowance $ 151,720 Appraised value, as adjusted Discount to fair value 0%-50% Discounted cash flow Net recoverable oil and gas reserves and forward-looking commodity prices. Discount rate - 9% 0% - 4% (1) Discounted cash flow Discount rates - 3.8% to 12.5% 0% - 1% (1) Estimated closing costs 10% Other real estate 18,875 Third-Party Appraisals Discount of fair value 0%-20% Estimated closing costs 10% (1) - Represents fair value as a percent of the unpaid principal balance.
Summary of Estimated Fair Values of Financial Instruments	The estimated fair values of the Company’s financial instruments are as follows: As of December 31, 2017 Carrying (In thousands) Amount Fair Value Level 1 Level 2 Level 3 Financial Assets: Cash and due from banks $ 238,707 $ 238,707 $ 238,707 $ — $ — Interest-bearing deposits in other banks 482,568 482,568 482,568 — — Federal funds sold 9,536 9,536 9,536 — — Securities available-for-sale 1,262,948 1,262,948 5,885 1,257,063 — Securities held-to-maturity 290 311 — 311 — Loans held for sale 61,359 61,359 — 61,359 — Net loans 8,165,851 8,134,903 — — 8,134,903 Derivative assets 3,985 3,985 — 3,985 — Other assets-net profits interests 15,833 15,833 — — 15,833 Financial Liabilities: Deposits 9,011,515 9,006,890 — 9,006,890 — Advances from FHLB 150,000 150,000 — 150,000 — Securities sold under agreements to repurchase 1,026 1,026 — 1,026 — Senior debt 184,629 194,484 — 194,484 — Subordinated debt 98,687 94,724 — 94,724 — Junior subordinated debentures 36,472 49,161 — 49,161 — Derivative liabilities 25,307 25,307 — 25,307 — As of December 31, 2016 (In thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial Assets: Cash and due from banks $ 48,017 $ 48,017 $ 48,017 $ — $ — Interest-bearing deposits in other banks 199,747 199,747 199,747 — — Federal funds sold 1,161 1,161 1,161 — — Securities available-for-sale 1,139,347 1,139,347 5,567 1,133,780 — Securities held-to-maturity 425 463 — 463 — Loans held for sale 17,822 17,822 — 17,822 — Net loans 7,350,443 7,395,003 — — 7,395,003 Derivative assets 4,361 4,361 — 4,361 — Other assets-net profits interests 19,425 19,818 — — 19,818 Financial Liabilities: Deposits 8,016,749 7,904,926 — 7,904,926 — Securities sold under agreements to repurchase 3,494 3,494 — 3,494 — Senior debt 193,788 191,076 — 191,076 — Subordinated debt 98,441 97,938 — 97,938 — Junior subordinated debentures 35,989 47,409 — 47,409 — Derivative liabilities 20,360 20,360 — 20,360 —

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Summary of Operating Results of Segments	The following tables present the operating results of the segments as of and for the years ended December 31, 2017, 2016 and 2015: For the Year Ended December 31, 2017 (In thousands) Banking Financial Services Corporate Consolidated Net interest income $ 344,987 $ (1,347 ) $ (17,424 ) $ 326,216 Provision for credit losses 9,735 — — 9,735 Noninterest income 51,286 47,956 632 99,874 Noninterest expense 194,212 36,178 2,966 233,356 Income tax expense (benefit) 88,417 2,000 (9,771 ) 80,646 Net income (loss) $ 103,909 $ 8,431 $ (9,987 ) $ 102,353 Total assets $ 10,854,206 $ 90,639 $ 4,081 $ 10,948,926 For the Year Ended December 31, 2016 (In thousands) Banking Financial Services Corporate Consolidated Net interest income $ 297,701 $ (201 ) $ (18,061 ) $ 279,439 Provision for credit losses 49,348 — — 49,348 Noninterest income 45,499 42,727 177 88,403 Noninterest expense 186,874 32,334 972 220,180 Income tax expense (benefit) 37,442 3,567 (8,469 ) 32,540 Net income (loss) $ 69,536 $ 6,625 $ (10,387 ) $ 65,774 Total assets $ 9,439,504 $ 84,003 $ 7,381 $ 9,530,888 For the Year Ended December 31, 2015 (In thousands) Banking Financial Services Corporate Consolidated Net interest income $ 265,450 $ (36 ) $ (17,636 ) $ 247,778 Provision for credit losses 35,984 — — 35,984 Noninterest income 38,697 40,964 242 79,903 Noninterest expense 200,544 31,393 395 232,332 Income tax expense (benefit) 23,673 3,337 (6,901 ) 20,109 Net income (loss) $ 43,946 $ 6,198 $ (10,888 ) $ 39,256

Equity-based Compensation (Tabl

Equity-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Fair Value Restricted Stock Units	. The fair value of these restricted stock units was estimated based upon the possible future value of the Company’s common stock using a Monte-Carlo simulation, which included the following assumptions as of the grant date: Fair value of common stock (non-marketable, per share) $ 14.83 Time to settlement date 2.08 years Volatility 30.0 % Risk-free rate 1.1 %
Summary of activity related to restricted stock unit awards	The following table summarizes the activity related to restricted stock unit awards for the years ended December 31, 2017, 2016 and 2015: For the Year Ended December 31, 2017 2016 2015 Number of Shares Fair Value per Unit at Award Date Number of Shares Fair Value per Unit at Award Date Number of Shares Fair Value per Unit at Award Date Non-vested at beginning of period 672,750 $ 5.14 258,375 $ 13.43 — $ — Units deemed improbable to vest — — (258,375 ) 13.43 — — Amended grants — — 395,250 5.14 — — New units — — 277,500 5.14 258,375 13.43 Non-vested at end of period 672,750 $ 5.14 672,750 $ 5.14 258,375 $ 13.43

Condensed Financial Informati54

Condensed Financial Information of Cadence Bancorporation (Parent Only) (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Schedule Of Condensed Financial Statements	Condensed Balance Sheets December 31, 2017 and 2016 (In thousands) 2017 2016 ASSETS Cash and due from banks $ 494 $ — Interest-bearing deposits with banks 150,587 50,330 Investment in consolidated bank subsidiary 1,488,223 1,315,336 Investment in consolidated nonbank subsidiaries 16,008 14,881 Other assets 3,587 7,381 Total Assets $ 1,658,899 $ 1,387,928 LIABILITIES AND SHAREHOLDER’S EQUITY Liabilities: Interest payable $ 813 $ 810 Senior debt 184,629 193,788 Subordinated debt 73,982 73,788 Junior subordinated debentures 36,472 35,989 Other liabilities 3,947 3,055 Total liabilities 299,843 307,430 Shareholder’s Equity: Common Stock 836 750 Additional Paid-in Capital 1,037,040 879,665 Retained earnings 340,213 232,614 Accumulated other comprehensive loss (“OCI”) (19,033 ) (32,531 ) Total Shareholder’s Equity 1,359,056 1,080,498 Total Liabilities and Shareholder’s Equity $ 1,658,899 $ 1,387,928 Condensed Statements of Income For the Years Ended December 31, 2017, 2016 and 2015 (In thousands) 2017 2016 2015 INCOME Dividends from bank subsidiary $ 11,000 $ 13,500 $ 8,500 Dividends from nonbank subsidiary — — 500 Interest income 65 25 21 Other income 632 176 22 Total income 11,697 13,701 9,043 EXPENSES Interest expense 17,424 18,060 17,635 Other expenses 3,305 2,092 271 Total expenses 20,729 20,152 17,906 Loss before income taxes and equity in undistributed income of subsidiaries (9,032 ) (6,451 ) (8,863 ) Equity in undistributed income of subsidiaries 103,390 64,424 41,132 Net income before income taxes 94,358 57,973 32,269 Income tax benefit (7,995 ) (7,801 ) (6,987 ) Net income $ 102,353 $ 65,774 $ 39,256 Condensed Statements of Cash Flows For the Years Ended December 31, 2017, 2016 and 2015 (In thousands) 2017 2016 2015 CASH FLOWS FROM OPERATING ACTIVITIES Net income $ 102,353 $ 65,774 $ 39,256 Adjustments to reconcile net income to net cash provided (used) in operations: Deferred income taxes 1,084 (1,598 ) (531 ) Equity in undistributed income of subsidiaries (103,390 ) (64,424 ) (41,132 ) Decrease in other assets 3,892 3,043 2,539 Increase (decrease) in interest payable 3 (102 ) 804 Increase (decrease) in other liabilities 891 (504 ) (747 ) Net cash provided by operating activities 4,833 2,189 189 CASH FLOWS FROM INVESTING ACTIVITIES Capital contributions to Bank subsidiary (50,000 ) — (20,000 ) (Increase) decrease in limited partnership investments (63 ) 463 (157 ) Net cash (used in) provided by investing activities (50,063 ) 463 (20,157 ) CASH FLOWS FROM FINANCING ACTIVITIES Issuance of subordinated debt, net of debt issuance costs — — 39,253 Issuance of senior debt, net of debt issuance costs — — 9,813 Purchase of senior debt (9,600 ) (78 ) — Proceeds from issuance of common stock 155,581 — — Net cash provided by (used in) financing activities 145,981 (78 ) 49,066 Net increase in cash and cash equivalents 100,751 2,574 29,098 Cash and cash equivalents at beginning of year 50,330 47,756 18,658 Cash and cash equivalents at end of year $ 151,081 $ 50,330 $ 47,756

Accumulated Other Comprehensi55

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	Activity within the balances in accumulated other comprehensive income (loss) is shown in the following tables for each of the years in the period ended December 31, 2017. (In thousands) Unrealized gains (losses) on securities available for sale Unrealized gains (losses) on defined benefit pension plans Unrealized gains (losses) on derivative instruments designated as cash flow hedges Accumulated other comprehensive gain (loss) Balance, December 31, 2014 $ 8,664 $ (599 ) $ — $ 8,065 Net change (2,763 ) 112 1,626 (1,025 ) Balance, December 31, 2015 5,901 (487 ) 1,626 7,040 Net change (27,720 ) (13 ) (11,838 ) (39,571 ) Balance, December 31, 2016 (21,819 ) (500 ) (10,212 ) (32,531 ) Period change 21,605 121 (2,982 ) 18,744 Reclassification of amounts within AOCI to retained earnings due to tax reform (See Notes 1 and 10) (1,946 ) (152 ) (3,148 ) (5,246 ) Balance, December 31, 2017 $ (2,160 ) $ (531 ) $ (16,342 ) $ (19,033 )

Quarterly Results of Operatio56

Quarterly Results of Operations (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Results of Operations	The following is a summary of the quarterly results of operations, for the years ended December 31, 2017 and 2016: Three Months Ended, (In thousands) December 31, 2017 September 30, 2017 June 30, 2017 March 31, 2017 Interest income $ 108,370 $ 99,503 $ 99,375 $ 89,619 Interest expense 20,459 18,340 16,991 14,861 Net interest income 87,911 81,163 82,384 74,758 Provision for credit losses (4,475 ) 1,723 6,701 5,786 Noninterest income (1) 25,656 27,124 22,989 24,105 Noninterest expense 66,371 56,530 56,134 54,321 Income before income taxes 51,671 50,034 42,538 38,756 Provision for income taxes 36,980 17,457 13,570 12,639 Net income $ 14,691 $ 32,577 $ 28,968 $ 26,117 Earnings per common share (Basic) $ 0.18 $ 0.39 $ 0.35 $ 0.35 Earnings per common share (Diluted) 0.17 0.39 0.35 0.35 Three Months Ended, (In thousands) December 31, 2016 September 30, 2016 June 30, 2016 March 31, 2016 Interest income $ 87,068 $ 84,654 $ 82,921 $ 80,607 Interest expense 14,570 14,228 13,672 13,341 Net interest income 72,498 70,426 69,249 67,266 Provision for credit losses (5,222 ) 29,627 14,471 10,472 Noninterest income (2) 22,361 22,791 23,105 20,146 Noninterest expense 55,394 54,876 55,868 54,042 Income before income taxes 44,687 8,714 22,015 22,898 Provision for income taxes 15,701 2,107 7,175 7,557 Net income $ 28,986 $ 6,607 $ 14,840 $ 15,341 Earnings per common share (Basic) $ 0.39 $ 0.09 $ 0.20 $ 0.20 Earnings per common share (Diluted) 0.38 0.09 0.20 0.20 (1 ) (2) Includes net securities gains of $1.3 million, $1.4 million, $1.0 million and $64 thousand during the fourth, third, second and first quarters of 2016, respectively.

Summary of Accounting Policie57

Summary of Accounting Policies - Additional Information (Details)	Apr. 07, 2017	Oct. 31, 2015USD ($)Branch	Dec. 31, 2017USD ($)Customer	Dec. 31, 2016USD ($)Customer	Dec. 31, 2015USD ($)	Dec. 31, 2012USD ($)	Mar. 31, 2015Branch
Significant Of Accounting Policies [Line Items]
Common stock, stock split conversion ratio	75
Stock split ratio			75-for-one
Loss from branch disposed of		$ (1,500,000)
Trading Securities			$ 0	$ 0
Reserve for unfunded commitments, Amount			800,000	1,600,000
FDIC claim in excess of first threshold						$ 347,000,000
Percentage of loss covered reimbursed by FDIC						80.00%
FDIC claim second threshold						$ 504,000,000
FDIC indemnification asset			0	0
Loan in process of foreclosure			4,400,000	600,000
Residential real estate properties held			7,605,000	18,875,000
Goodwill impairment			0	0	$ 0
Expense under long term incentive plan			7,300,000	4,400,000	1,600,000
ASU No. 2018-02
Significant Of Accounting Policies [Line Items]
Reclassification from AOCI to retained earnings			$ 5,200,000
Executives And Senior Officers
Significant Of Accounting Policies [Line Items]
Percentage of base deferred compensation			25.00%
Percentage of incentive compensation			100.00%
Employee Contribution			$ 0	$ 0	$ 0
Maximum
Significant Of Accounting Policies [Line Items]
Federal funds sold periods			7 days
Minimum
Significant Of Accounting Policies [Line Items]
Federal funds sold periods			1 day
401 K Plan
Significant Of Accounting Policies [Line Items]
Retained earning contribution			100.00%
Employer match 100% up to 3% Of Employee Compensation | 401 K Plan
Significant Of Accounting Policies [Line Items]
Defined contribution plan percentage			100.00%
Employer match 100% up to 3% Of Employee Compensation | 401 K Plan | Maximum
Significant Of Accounting Policies [Line Items]
Employee contribution percentage			3.00%
Employer match 50% Between 3% to 5% Of Employee Compensation | 401 K Plan
Significant Of Accounting Policies [Line Items]
Defined contribution plan percentage			50.00%
Employee contribution percentage			2.00%
Variable Interest Entity, Not Primary Beneficiary
Significant Of Accounting Policies [Line Items]
Number of loan customers | Customer			2	2
Net Profits interest			$ 15,800,000	$ 19,400,000
OREO
Significant Of Accounting Policies [Line Items]
Residential real estate properties held			$ 2,700,000	$ 5,100,000
Florida
Significant Of Accounting Policies [Line Items]
Number of branches disposed | Branch							6
Georgia
Significant Of Accounting Policies [Line Items]
Number of branches disposed | Branch		2

Summary of Accounting Policie58

Summary of Accounting Policies - Summary of Allocation of Sale Price to Assets Sold and Liabilities Transferred (Details) $ in Thousands	Dec. 31, 2015USD ($)
Disposal Group Including Discontinued Operation Unclassified Balance Sheet Disclosures [Abstract]
Cash on hand	$ 1,254
Loans	42,477
Premises and equipment	3,095
Other assets	113
Total assets sold	46,939
Deposits	253,823
Other liabilities	301
Total liabilities transferred	254,124
Cash paid	$ 207,185

Summary of Accounting Policie59

Summary of Accounting Policies - Summary of Loans Held for Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Accounting Policies [Line Items]
Loans held for sale	$ 61,359	$ 17,822
Residential Mortgage
Schedule Of Accounting Policies [Line Items]
Loans held for sale	5,834	8,369
Commercial Loans
Schedule Of Accounting Policies [Line Items]
Loans held for sale	$ 55,525	$ 9,453

Securities - Summary of Amortiz

Securities - Summary of Amortized Cost and Estimated Fair Value of Securities Available-for-Sale and Securities Held-to-Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Securities available-for-sale, Amortized Cost	$ 1,268,450	$ 1,177,060
Securities available-for-sale, Gross Unrealized Gains	10,683	4,802
Securities available-for-sale, Gross Unrealized Losses	16,185	42,515
Securities available-for-sale, Estimated Fair Value	1,262,948	1,139,347
Securities held-to-maturity, Amortized Cost	290	425
Securities held-to-maturity, Estimated Fair Value	311	463
U.S. Treasury Securities
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Securities available-for-sale, Amortized Cost	100,575	100,736
Securities available-for-sale, Gross Unrealized Losses	3,731	3,951
Securities available-for-sale, Estimated Fair Value	96,844	96,785
Obligations of U.S. Government Agencies
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Securities available-for-sale, Amortized Cost	80,552	97,340
Securities available-for-sale, Gross Unrealized Gains	738	508
Securities available-for-sale, Gross Unrealized Losses	66	320
Securities available-for-sale, Estimated Fair Value	81,224	97,528
Residential Pass-through | Guaranteed by GNMA
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Securities available-for-sale, Amortized Cost	106,461	152,918
Securities available-for-sale, Gross Unrealized Gains	676	1,401
Securities available-for-sale, Gross Unrealized Losses	1,110	1,166
Securities available-for-sale, Estimated Fair Value	106,027	153,153
Residential Pass-through | Issued by FNMA and FHLMC
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Securities available-for-sale, Amortized Cost	431,409	267,035
Securities available-for-sale, Gross Unrealized Gains	1,284	1,499
Securities available-for-sale, Gross Unrealized Losses	2,271	3,206
Securities available-for-sale, Estimated Fair Value	430,422	265,328
Other Residential Mortgage-Backed Securities
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Securities available-for-sale, Amortized Cost	47,379	48,076
Securities available-for-sale, Gross Unrealized Gains	97	375
Securities available-for-sale, Gross Unrealized Losses	1,084	890
Securities available-for-sale, Estimated Fair Value	46,392	47,561
Commercial Mortgage-Backed Securities
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Securities available-for-sale, Amortized Cost	76,201	66,720
Securities available-for-sale, Gross Unrealized Gains	63
Securities available-for-sale, Gross Unrealized Losses	4,069	4,107
Securities available-for-sale, Estimated Fair Value	72,195	62,613
Total MBS
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Securities available-for-sale, Amortized Cost	661,450	534,749
Securities available-for-sale, Gross Unrealized Gains	2,120	3,275
Securities available-for-sale, Gross Unrealized Losses	8,534	9,369
Securities available-for-sale, Estimated Fair Value	655,036	528,655
Obligations of States and Municipal Subdivisions
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Securities available-for-sale, Amortized Cost	420,111	438,655
Securities available-for-sale, Gross Unrealized Gains	7,539	870
Securities available-for-sale, Gross Unrealized Losses	3,691	28,713
Securities available-for-sale, Estimated Fair Value	423,959	410,812
Securities held-to-maturity, Amortized Cost	290	425
Securities held-to-maturity, Gross Unrealized Gains	21	38
Securities held-to-maturity, Estimated Fair Value	311	463
Other Securities
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Securities available-for-sale, Amortized Cost	5,762	5,580
Securities available-for-sale, Gross Unrealized Gains	286	149
Securities available-for-sale, Gross Unrealized Losses	163	162
Securities available-for-sale, Estimated Fair Value	$ 5,885	$ 5,567

Securities - Schedule of Contra

Securities - Schedule of Contractual Maturities of Securities Available-for-Sale and Securities Held-to-Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Investments Debt And Equity Securities [Abstract]
Available-for-Sale, Due after one year through five years, Amortized Cost	$ 108,378
Available-for-Sale, Due after five years through ten years, Amortized Cost	19,397
Available-for-Sale, Due after ten years, Amortized Cost	473,463
Available-for-Sale, Mortgage-backed securities and other securities, Amortized Cost	667,212
Available-for-Sale, Total, Amortized Cost	1,268,450
Available-for-Sale, Due after one year through five years, Estimated Fair Value	104,719
Available-for-Sale, Due after five years through ten years, Estimated Fair Value	19,653
Available-for-Sale, Due after ten years, Estimated Fair Value	477,655
Available-for-Sale, Mortgage-backed securities and other securities, Estimated Fair Value	660,921
Available-for-Sale, Total, Estimated Fair Value	1,262,948
Held-to-Maturity, Due after one year through five years, Amortized Cost	290
Securities held-to-maturity, Amortized Cost	290	$ 425
Held-to-Maturity, Due after one year through five years, Estimated Fair Value	311
Held-to-Maturity, Total, Estimated Fair Value	$ 311	$ 463

Securities - Additional Informa

Securities - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017USD ($)Security	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Investments Debt And Equity Securities [Abstract]
Other-than-temporary impairment charges	$ 0	$ 0	$ 0
Carrying value of securities pledged	507,300,000	380,400,000
Securities, held-to-maturity with unrealized losses	$ 0	$ 0
Percentage of fair value of securities in investment portfolio reflect unrealized loss	58.00%	75.00%
Number of securities in a loss position for more than twelve months | Security	90
Number of securities in a loss position for less than twelve months | Security	39

Securities - Summary of Proceed

Securities - Summary of Proceeds from Sales, Gross Gains, and Gross Losses on Sales of Securities Available for Sale (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments Debt And Equity Securities [Abstract]
Gross realized gains									$ 167	$ 4,172	$ 1,444
Gross realized losses									(313)	(436)	(273)
Realized gains (losses) on sale of securities available for sale, net	$ 16	$ 1	$ (244)	$ 81	$ 1,300	$ 1,400	$ 1,000	$ 64,000	$ (146)	$ 3,736	$ 1,171

Securities - Schedule of Securi

Securities - Schedule of Securities Classified as Available-for-Sale with Unrealized Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Losses less than 12 Months, Estimated Fair Value	$ 310,452	$ 821,330
Losses less than 12 Months, Gross Unrealized Losses	1,521	41,423
Losses more than 12 Months, Estimated Fair Value	422,669	34,345
Losses more than 12 Months, Gross Unrealized Losses	14,664	1,092
U.S. Treasury Securities
Schedule Of Available For Sale Securities [Line Items]
Losses less than 12 Months, Estimated Fair Value		96,785
Losses less than 12 Months, Gross Unrealized Losses		3,951
Losses more than 12 Months, Estimated Fair Value	96,844
Losses more than 12 Months, Gross Unrealized Losses	3,731
Obligations of U.S. Government Agencies
Schedule Of Available For Sale Securities [Line Items]
Losses less than 12 Months, Estimated Fair Value	1,577	51,463
Losses less than 12 Months, Gross Unrealized Losses	9	277
Losses more than 12 Months, Estimated Fair Value	14,323	12,150
Losses more than 12 Months, Gross Unrealized Losses	57	43
MBS
Schedule Of Available For Sale Securities [Line Items]
Losses less than 12 Months, Estimated Fair Value	306,274	328,374
Losses less than 12 Months, Gross Unrealized Losses	1,490	8,482
Losses more than 12 Months, Estimated Fair Value	172,324	17,979
Losses more than 12 Months, Gross Unrealized Losses	7,044	887
Obligations of States and Municipal Subdivisions
Schedule Of Available For Sale Securities [Line Items]
Losses less than 12 Months, Estimated Fair Value	2,601	344,708
Losses less than 12 Months, Gross Unrealized Losses	22	28,713
Losses more than 12 Months, Estimated Fair Value	134,870
Losses more than 12 Months, Gross Unrealized Losses	3,669
Other Securities
Schedule Of Available For Sale Securities [Line Items]
Losses more than 12 Months, Estimated Fair Value	4,308	4,216
Losses more than 12 Months, Gross Unrealized Losses	$ 163	$ 162

Loans and Allowance for Credi65

Loans and Allowance for Credit Losses - Total Loans Outstanding by Portfolio Segment and Class of Financing Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	$ 8,279,778	$ 7,457,429
Unearned discount and fees	(26,351)	(24,718)
Total (Net of unearned discount and fees)	8,253,427	7,432,711
ACI
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	260,560	324,282
Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	5,133,786	4,665,222
Commercial and Industrial | ACI
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	29,577	38,047
Commercial and Industrial | General C&I
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	2,746,454	2,416,665
Commercial and Industrial | General C&I | ACI
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	23,428	31,709
Commercial and Industrial | Energy Sector
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	935,371	939,369
Commercial and Industrial | Restaurant Industry
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	1,035,538	864,085
Commercial and Industrial | Healthcare
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	416,423	445,103
Commercial and Industrial | Healthcare | ACI
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	6,149	6,338
Commercial Real Estate
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	1,158,401	1,072,707
Commercial Real Estate | ACI
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	79,861	98,170
Commercial Real Estate | Income Producing
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	1,082,929	1,001,703
Commercial Real Estate | Income Producing | ACI
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	79,861	96,673
Commercial Real Estate | Land and Development
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	75,472	71,004
Commercial Real Estate | Land and Development | ACI
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable		1,497
Consumer
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	1,765,736	1,525,859
Consumer | ACI
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	151,122	188,065
Consumer | Residential Real Estate
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	1,690,814	1,457,170
Consumer | Residential Real Estate | ACI
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	149,942	186,375
Consumer | Other
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	74,922	68,689
Consumer | Other | ACI
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	1,180	1,690
Small Business Lending
Accounts Notes And Loans Receivable [Line Items]
Total loan outstanding and financing receivable	$ 221,855	$ 193,641

Loans and Allowance for Credi66

Loans and Allowance for Credit Losses - Summary of Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Balance at beginning of period				$ 82,268				$ 79,783	$ 82,268	$ 79,783	$ 53,520
Provision for credit losses	$ (4,475)	$ 1,723	$ 6,701	5,786	$ (5,222)	$ 29,627	$ 14,471	10,472	9,735	49,348	35,984
Charge-offs									(6,871)	(49,302)	(10,734)
Recoveries									2,444	2,439	1,013
Balance at end of period	87,576				82,268				87,576	82,268	79,783
Loans ending balance	8,279,778				7,457,429				8,279,778	7,457,429
Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Balance at beginning of period				54,688				55,824	54,688	55,824	28,930
Provision for credit losses									5,883	43,782	35,355
Charge-offs									(5,645)	(46,367)	(8,525)
Recoveries									993	1,449	64
Balance at end of period	55,919				54,688				55,919	54,688	55,824
Loans ending balance	5,133,786				4,665,222				5,133,786	4,665,222
Commercial Real Estate
Accounts Notes And Loans Receivable [Line Items]
Balance at beginning of period				10,103				8,136	10,103	8,136	7,050
Provision for credit losses									1,737	1,389	1,018
Charge-offs									(93)		(271)
Recoveries									243	578	339
Balance at end of period	11,990				10,103				11,990	10,103	8,136
Loans ending balance	1,158,401				1,072,707				1,158,401	1,072,707
Consumer
Accounts Notes And Loans Receivable [Line Items]
Balance at beginning of period				13,265				13,450	13,265	13,450	15,552
Provision for credit losses									1,746	1,506	(1,412)
Charge-offs									(929)	(2,094)	(1,291)
Recoveries									901	403	601
Balance at end of period	14,983				13,265				14,983	13,265	13,450
Loans ending balance	1,765,736				1,525,859				1,765,736	1,525,859
Small Business Lending
Accounts Notes And Loans Receivable [Line Items]
Balance at beginning of period				$ 4,212				$ 2,373	4,212	2,373	1,988
Provision for credit losses									369	2,671	1,023
Charge-offs									(204)	(841)	(647)
Recoveries									307	9	9
Balance at end of period	4,684				4,212				4,684	4,212	2,373
Loans ending balance	221,855				193,641				221,855	193,641
ACI Loans
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	8,300				10,043				8,300	10,043	13,834
Allowance for credit losses, individually evaluated for impairment	224				235				224	235	500
Loans collectively evaluated for impairment	241,959				301,769				241,959	301,769
Loans individually evaluated for impairment	18,601				22,513				18,601	22,513
Loans ending balance	260,560				324,282				260,560	324,282
ACI Loans | Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	5				176				5	176	2,062
Allowance for credit losses, individually evaluated for impairment											168
Loans collectively evaluated for impairment	19,486				26,276				19,486	26,276
Loans individually evaluated for impairment	10,091				11,772				10,091	11,772
Loans ending balance	29,577				38,047				29,577	38,047
ACI Loans | Commercial Real Estate
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	2,006				2,652				2,006	2,652	3,084
Allowance for credit losses, individually evaluated for impairment	4				3				4	3
Loans collectively evaluated for impairment	71,675				87,825				71,675	87,825
Loans individually evaluated for impairment	8,186				10,345				8,186	10,345
Loans ending balance	79,861				98,170				79,861	98,170
ACI Loans | Consumer
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	6,289				7,215				6,289	7,215	8,688
Allowance for credit losses, individually evaluated for impairment	220				232				220	232	332
Loans collectively evaluated for impairment	150,798				187,668				150,798	187,668
Loans individually evaluated for impairment	324				396				324	396
Loans ending balance	151,122				188,065				151,122	188,065
ANCI Loans
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	1,338				908				1,338	908	1,002
Allowance for credit losses, individually evaluated for impairment	58				70				58	70	61
Loans collectively evaluated for impairment	199,389				232,528				199,389	232,528
Loans individually evaluated for impairment	1,892				1,557				1,892	1,557
ANCI Loans | Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	864				299				864	299	425
Loans collectively evaluated for impairment	58,775				51,694				58,775	51,694
ANCI Loans | Commercial Real Estate
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	130				243				130	243	227
Loans collectively evaluated for impairment	15,926				20,306				15,926	20,306
ANCI Loans | Consumer
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	49				94				49	94	65
Allowance for credit losses, individually evaluated for impairment	36				37				36	37	40
Loans collectively evaluated for impairment	113,357				151,759				113,357	151,759
Loans individually evaluated for impairment	1,582				1,168				1,582	1,168
ANCI Loans | Small Business Lending
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	295				272				295	272	285
Allowance for credit losses, individually evaluated for impairment	22				33				22	33	21
Loans collectively evaluated for impairment	11,331				8,769				11,331	8,769
Loans individually evaluated for impairment	310				389				310	389
Originated Loans
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	69,192				69,407				69,192	69,407	59,883
Allowance for credit losses, individually evaluated for impairment	8,464				1,605				8,464	1,605	4,503
Loans collectively evaluated for impairment	7,746,474				6,747,428				7,746,474	6,747,428
Loans individually evaluated for impairment	71,463				151,634				71,463	151,634
Originated Loans | Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	46,591				52,615				46,591	52,615	48,666
Allowance for credit losses, individually evaluated for impairment	8,459				1,598				8,459	1,598	4,503
Loans collectively evaluated for impairment	4,974,973				4,424,822				4,974,973	4,424,822
Loans individually evaluated for impairment	70,461				150,658				70,461	150,658
Originated Loans | Commercial Real Estate
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	9,850				7,205				9,850	7,205	4,825
Loans collectively evaluated for impairment	1,062,614				954,231				1,062,614	954,231
Originated Loans | Consumer
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	8,389				5,687				8,389	5,687	4,325
Loans collectively evaluated for impairment	1,499,260				1,184,442				1,499,260	1,184,442
Loans individually evaluated for impairment	415				426				415	426
Originated Loans | Small Business Lending
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses, collectively evaluated for impairment	4,362				3,900				4,362	3,900	$ 2,067
Allowance for credit losses, individually evaluated for impairment	5				7				5	7
Loans collectively evaluated for impairment	209,627				183,933				209,627	183,933
Loans individually evaluated for impairment	$ 587				$ 550				$ 587	$ 550

Loans and Allowance for Credi67

Loans and Allowance for Credit Losses - Summary of Impaired Loans (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Accounts Notes And Loans Receivable [Line Items]
Recorded Investment in Impaired Loans, With no related allowance for credit losses	[1]	$ 21,590	$ 112,699
Unpaid Principal Balance, With no related allowance for credit losses		30,508	118,313
Nonaccrual Loans Included in Impaired Loans, with no related allowance for credit losses		15,298	92,286
Undisbursed Commitments, With no related allowance for credit losses		387	9,829
Recorded Investment in Impaired Loans, With allowance for credit losses recorded	[1]	52,020	40,696
Unpaid Principal Balance, With allowance for credit losses recorded		55,800	46,881
Related Specific Allowance, With allowance for credit losses recorded		8,522	1,675
Nonaccrual Loans Included in Impaired Loans, With allowance for credit losses recorded		28,060	28,357
Undisbursed Commitments, With allowance for credit losses recorded		2,902	4,788
Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Recorded Investment in Impaired Loans, With no related allowance for credit losses	[1]	19,832	111,534
Unpaid Principal Balance, With no related allowance for credit losses		28,301	116,748
Nonaccrual Loans Included in Impaired Loans, with no related allowance for credit losses		15,014	91,987
Undisbursed Commitments, With no related allowance for credit losses		387	9,828
Recorded Investment in Impaired Loans, With allowance for credit losses recorded	[1]	50,874
Unpaid Principal Balance, With allowance for credit losses recorded		54,385
Related Specific Allowance, With allowance for credit losses recorded		8,459
Nonaccrual Loans Included in Impaired Loans, With allowance for credit losses recorded		28,000
Undisbursed Commitments, With allowance for credit losses recorded		2,902
Commercial and Industrial | General C&I
Accounts Notes And Loans Receivable [Line Items]
Recorded Investment in Impaired Loans, With no related allowance for credit losses	[1]	5,010	12,334
Unpaid Principal Balance, With no related allowance for credit losses		4,994	13,426
Nonaccrual Loans Included in Impaired Loans, with no related allowance for credit losses		192	6,838
Undisbursed Commitments, With no related allowance for credit losses			1,363
Commercial and Industrial | Energy Sector
Accounts Notes And Loans Receivable [Line Items]
Recorded Investment in Impaired Loans, With no related allowance for credit losses	[1]	14,822	99,200
Unpaid Principal Balance, With no related allowance for credit losses		23,307	103,322
Nonaccrual Loans Included in Impaired Loans, with no related allowance for credit losses		14,822	85,149
Undisbursed Commitments, With no related allowance for credit losses		387	8,465
Recorded Investment in Impaired Loans, With allowance for credit losses recorded	[1]	39,857	39,319
Unpaid Principal Balance, With allowance for credit losses recorded		43,416	45,243
Related Specific Allowance, With allowance for credit losses recorded		8,353	1,598
Nonaccrual Loans Included in Impaired Loans, With allowance for credit losses recorded		28,000	28,228
Undisbursed Commitments, With allowance for credit losses recorded		402	4,788
Commercial and Industrial | Restaurant Industry
Accounts Notes And Loans Receivable [Line Items]
Recorded Investment in Impaired Loans, With allowance for credit losses recorded	[1]	11,017
Unpaid Principal Balance, With allowance for credit losses recorded		10,969
Related Specific Allowance, With allowance for credit losses recorded		106
Undisbursed Commitments, With allowance for credit losses recorded		2,500
Consumer
Accounts Notes And Loans Receivable [Line Items]
Recorded Investment in Impaired Loans, With no related allowance for credit losses	[1]	1,509	866
Unpaid Principal Balance, With no related allowance for credit losses		1,512	862
Nonaccrual Loans Included in Impaired Loans, with no related allowance for credit losses		35
Undisbursed Commitments, With no related allowance for credit losses			1
Consumer | Residential Real Estate
Accounts Notes And Loans Receivable [Line Items]
Recorded Investment in Impaired Loans, With no related allowance for credit losses	[1]	1,093	437
Unpaid Principal Balance, With no related allowance for credit losses		1,097	435
Nonaccrual Loans Included in Impaired Loans, with no related allowance for credit losses		35
Recorded Investment in Impaired Loans, With allowance for credit losses recorded	[1]	496	736
Unpaid Principal Balance, With allowance for credit losses recorded		494	741
Related Specific Allowance, With allowance for credit losses recorded		36	37
Nonaccrual Loans Included in Impaired Loans, With allowance for credit losses recorded			39
Consumer | Other
Accounts Notes And Loans Receivable [Line Items]
Recorded Investment in Impaired Loans, With no related allowance for credit losses	[1]	416	429
Unpaid Principal Balance, With no related allowance for credit losses		415	427
Undisbursed Commitments, With no related allowance for credit losses			1
Small Business Lending
Accounts Notes And Loans Receivable [Line Items]
Recorded Investment in Impaired Loans, With no related allowance for credit losses	[1]	249	299
Unpaid Principal Balance, With no related allowance for credit losses		695	703
Nonaccrual Loans Included in Impaired Loans, with no related allowance for credit losses		249	299
Recorded Investment in Impaired Loans, With allowance for credit losses recorded	[1]	650	641
Unpaid Principal Balance, With allowance for credit losses recorded		921	897
Related Specific Allowance, With allowance for credit losses recorded		27	40
Nonaccrual Loans Included in Impaired Loans, With allowance for credit losses recorded		$ 60	$ 90
[1]	The recorded investment of a loan also includes any interest receivable, net unearned discount or fees, and unamortized premium or discount.

Loans and Allowance for Credi68

Loans and Allowance for Credit Losses - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017USD ($)TDR	Dec. 31, 2016USD ($)TDR	Dec. 31, 2015USD ($)TDR
Accounts Notes And Loans Receivable [Line Items]
Interest income recognized for impaired loans | $	$ 1,600,000	$ 1,400,000	$ 800,000
Contractual interest recognized on cash basis | $	$ 1,500,000	$ 1,100,000	$ 0
Number of TDRs experiencing payment default | TDR	0	0
Number of TDRs | TDR	6	9	11
ACI Loans
Accounts Notes And Loans Receivable [Line Items]
Number of TDRs experiencing payment default | TDR	0	0	0
Number of TDRs | TDR	0	1
Recorded Investment | $		$ 954,000
Residential Real Estate
Accounts Notes And Loans Receivable [Line Items]
Foreclosed residential properties | $	$ 2,700,000	5,100,000
Consumer Loans | Residential Real Estate
Accounts Notes And Loans Receivable [Line Items]
Residential mortgage loans in process of foreclosure | $	$ 4,400,000	$ 2,100,000
Small Business Lending
Accounts Notes And Loans Receivable [Line Items]
Number of TDRs experiencing payment default | TDR			2
Recorded Investment experienced payment default | $			$ 459,000
Number of TDRs | TDR	1	1

Loans and Allowance for Credi69

Loans and Allowance for Credit Losses - Summary of Average Recorded Investment in Impaired Originated and ANCI Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Average recorded investment	$ 122,297	$ 171,634	$ 29,015
Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Average recorded investment	119,540	169,483	26,452
Commercial and Industrial | General C&I
Accounts Notes And Loans Receivable [Line Items]
Average recorded investment	8,586	11,291	6,347
Commercial and Industrial | Energy Sector
Accounts Notes And Loans Receivable [Line Items]
Average recorded investment	108,751	158,192	20,105
Commercial and Industrial | Restaurant Industry
Accounts Notes And Loans Receivable [Line Items]
Average recorded investment	2,203
Consumer
Accounts Notes And Loans Receivable [Line Items]
Average recorded investment	1,812	1,604	1,840
Consumer | Residential Real Estate
Accounts Notes And Loans Receivable [Line Items]
Average recorded investment	1,426	1,206	1,567
Consumer | Other
Accounts Notes And Loans Receivable [Line Items]
Average recorded investment	386	398	273
Small Business Lending
Accounts Notes And Loans Receivable [Line Items]
Average recorded investment	$ 945	$ 547	$ 723

Loans and Allowance for Credi70

Loans and Allowance for Credit Losses - Summary of Originated and ANCI Loans that Were Modified Into TDRs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)TDR	Dec. 31, 2016USD ($)TDR	Dec. 31, 2015USD ($)TDR
Financing Receivable Modifications [Line Items]
Number of TDRs | TDR	6	9	11
Recorded Investment | $	$ 16,904	$ 44,695	$ 27,038
Commercial and Industrial
Financing Receivable Modifications [Line Items]
Number of TDRs | TDR	3	6	5
Recorded Investment | $	$ 16,027	$ 43,609	$ 26,459
Consumer
Financing Receivable Modifications [Line Items]
Number of TDRs | TDR	2	2	6
Recorded Investment | $	$ 739	$ 534	$ 579
Small Business Lending
Financing Receivable Modifications [Line Items]
Number of TDRs | TDR	1	1
Recorded Investment | $	$ 138	$ 552

Loans and Allowance for Credi71

Loans and Allowance for Credit Losses - Schedule of Number of Loans Modified (Details) - TDR	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Number of Loans Modified	6	9	11
Rate Concession
Accounts Notes And Loans Receivable [Line Items]
Number of Loans Modified	3	2	5
Modified Terms and/or Other Concessions
Accounts Notes And Loans Receivable [Line Items]
Number of Loans Modified	3	5	6
Forbearance Agreement
Accounts Notes And Loans Receivable [Line Items]
Number of Loans Modified		2
Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Number of Loans Modified	3	6	5
Commercial and Industrial | Rate Concession
Accounts Notes And Loans Receivable [Line Items]
Number of Loans Modified	2	1
Commercial and Industrial | Modified Terms and/or Other Concessions
Accounts Notes And Loans Receivable [Line Items]
Number of Loans Modified	1	3	5
Commercial and Industrial | Forbearance Agreement
Accounts Notes And Loans Receivable [Line Items]
Number of Loans Modified		2
Consumer
Accounts Notes And Loans Receivable [Line Items]
Number of Loans Modified	2	2	6
Consumer | Rate Concession
Accounts Notes And Loans Receivable [Line Items]
Number of Loans Modified			5
Consumer | Modified Terms and/or Other Concessions
Accounts Notes And Loans Receivable [Line Items]
Number of Loans Modified	2	2	1
Small Business Lending
Accounts Notes And Loans Receivable [Line Items]
Number of Loans Modified	1	1
Small Business Lending | Rate Concession
Accounts Notes And Loans Receivable [Line Items]
Number of Loans Modified	1	1

Loans and Allowance for Credi72

Loans and Allowance for Credit Losses - Summary of Credit Exposure by Portfolio Segment and Class of Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable Recorded Investment [Line Items]
Recorded investment	$ 278,587	$ 371,673
Special Mention
Financing Receivable Recorded Investment [Line Items]
Recorded investment	96,869	97,427
Special Mention | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	6,930	11,354
Substandard
Financing Receivable Recorded Investment [Line Items]
Recorded investment	174,053	273,457
Substandard | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	36,888	50,188
Doubtful
Financing Receivable Recorded Investment [Line Items]
Recorded investment	7,665	789
Doubtful | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	37	33
Commercial and Industrial
Financing Receivable Recorded Investment [Line Items]
Recorded investment	252,600	360,235
Commercial and Industrial | General C&I
Financing Receivable Recorded Investment [Line Items]
Recorded investment	127,874	63,908
Commercial and Industrial | Energy Sector
Financing Receivable Recorded Investment [Line Items]
Recorded investment	107,613	270,679
Commercial and Industrial | Restaurant Industry
Financing Receivable Recorded Investment [Line Items]
Recorded investment	17,042	16,169
Commercial and Industrial | Healthcare
Financing Receivable Recorded Investment [Line Items]
Recorded investment	71	9,479
Commercial and Industrial | Special Mention
Financing Receivable Recorded Investment [Line Items]
Recorded investment	85,086	92,500
Commercial and Industrial | Special Mention | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	737	939
Commercial and Industrial | Special Mention | General C&I
Financing Receivable Recorded Investment [Line Items]
Recorded investment	80,550	36,419
Commercial and Industrial | Special Mention | General C&I | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	737	939
Commercial and Industrial | Special Mention | Energy Sector
Financing Receivable Recorded Investment [Line Items]
Recorded investment		30,433
Commercial and Industrial | Special Mention | Restaurant Industry
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4,536	16,169
Commercial and Industrial | Special Mention | Healthcare
Financing Receivable Recorded Investment [Line Items]
Recorded investment		9,479
Commercial and Industrial | Substandard
Financing Receivable Recorded Investment [Line Items]
Recorded investment	159,880	266,946
Commercial and Industrial | Substandard | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	7,321	5,484
Commercial and Industrial | Substandard | General C&I
Financing Receivable Recorded Investment [Line Items]
Recorded investment	47,324	27,489
Commercial and Industrial | Substandard | General C&I | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	1,173	5,484
Commercial and Industrial | Substandard | Energy Sector
Financing Receivable Recorded Investment [Line Items]
Recorded investment	99,979	239,457
Commercial and Industrial | Substandard | Restaurant Industry
Financing Receivable Recorded Investment [Line Items]
Recorded investment	12,506
Commercial and Industrial | Substandard | Healthcare
Financing Receivable Recorded Investment [Line Items]
Recorded investment	71
Commercial and Industrial | Substandard | Healthcare | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	6,148
Commercial and Industrial | Doubtful
Financing Receivable Recorded Investment [Line Items]
Recorded investment	7,634	789
Commercial and Industrial | Doubtful | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	37	33
Commercial and Industrial | Doubtful | General C&I | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	37	33
Commercial and Industrial | Doubtful | Energy Sector
Financing Receivable Recorded Investment [Line Items]
Recorded investment	7,634	789
Commercial Real Estate
Financing Receivable Recorded Investment [Line Items]
Recorded investment	46	364
Commercial Real Estate | Income Producing
Financing Receivable Recorded Investment [Line Items]
Recorded investment	26
Commercial Real Estate | Land and Development
Financing Receivable Recorded Investment [Line Items]
Recorded investment	20	364
Commercial Real Estate | Special Mention
Financing Receivable Recorded Investment [Line Items]
Recorded investment	20	23
Commercial Real Estate | Special Mention | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	2,179	6,746
Commercial Real Estate | Special Mention | Income Producing | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	1,446	5,813
Commercial Real Estate | Special Mention | Land and Development
Financing Receivable Recorded Investment [Line Items]
Recorded investment	20	23
Commercial Real Estate | Special Mention | Land and Development | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	733	933
Commercial Real Estate | Substandard
Financing Receivable Recorded Investment [Line Items]
Recorded investment	26	341
Commercial Real Estate | Substandard | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	6,515	16,831
Commercial Real Estate | Substandard | Income Producing
Financing Receivable Recorded Investment [Line Items]
Recorded investment	26
Commercial Real Estate | Substandard | Income Producing | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4,425	13,591
Commercial Real Estate | Substandard | Land and Development
Financing Receivable Recorded Investment [Line Items]
Recorded investment		341
Commercial Real Estate | Substandard | Land and Development | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	2,090	3,240
Consumer
Financing Receivable Recorded Investment [Line Items]
Recorded investment	21,059	7,376
Consumer | Residential Real Estate
Financing Receivable Recorded Investment [Line Items]
Recorded investment	20,026	6,449
Consumer | Other
Financing Receivable Recorded Investment [Line Items]
Recorded investment	1,033	927
Consumer | Special Mention
Financing Receivable Recorded Investment [Line Items]
Recorded investment	8,283	3,086
Consumer | Special Mention | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4,014	3,669
Consumer | Special Mention | Residential Real Estate
Financing Receivable Recorded Investment [Line Items]
Recorded investment	7,610	2,578
Consumer | Special Mention | Residential Real Estate | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	3,900	3,655
Consumer | Special Mention | Other
Financing Receivable Recorded Investment [Line Items]
Recorded investment	673	508
Consumer | Special Mention | Other | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	114	14
Consumer | Substandard
Financing Receivable Recorded Investment [Line Items]
Recorded investment	12,772	4,290
Consumer | Substandard | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	23,052	27,873
Consumer | Substandard | Residential Real Estate
Financing Receivable Recorded Investment [Line Items]
Recorded investment	12,416	3,871
Consumer | Substandard | Residential Real Estate | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	22,635	27,586
Consumer | Substandard | Other
Financing Receivable Recorded Investment [Line Items]
Recorded investment	356	419
Consumer | Substandard | Other | ACI Loans
Financing Receivable Recorded Investment [Line Items]
Recorded investment	417	287
Consumer | Doubtful
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4
Consumer | Doubtful | Other
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4
Small Business Lending
Financing Receivable Recorded Investment [Line Items]
Recorded investment	4,882	3,698
Small Business Lending | Special Mention
Financing Receivable Recorded Investment [Line Items]
Recorded investment	3,480	1,818
Small Business Lending | Substandard
Financing Receivable Recorded Investment [Line Items]
Recorded investment	1,375	$ 1,880
Small Business Lending | Doubtful
Financing Receivable Recorded Investment [Line Items]
Recorded investment	$ 27

Loans and Allowance for Credi73

Loans and Allowance for Credit Losses - Summary of Aging of Past Due Originated and ANCI Loans by Portfolio Segment and Class of Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	$ 4,768	$ 9,658
Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	1,361	1,641
Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	827	586
Non-Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	474	6,947
Non-Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	293	377
Non-Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	13,206	2,901
Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	33,495	115,049
Commercial and Industrial | Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	59	3,930
Commercial and Industrial | Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	476
Commercial and Industrial | Non-Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	263	6,839
Commercial and Industrial | Non-Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	10,507	697
Commercial and Industrial | Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	32,315	113,062
Commercial and Industrial | General C&I | Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	59	3,930
Commercial and Industrial | General C&I | Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	476
Commercial and Industrial | General C&I | Non-Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	192	6,839
Commercial and Industrial | General C&I | Non-Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		250
Commercial and Industrial | General C&I | Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		125
Commercial and Industrial | Energy Sector | Non-Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	10,507	447
Commercial and Industrial | Energy Sector | Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	32,315	112,937
Commercial and Industrial | Healthcare | Non-Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	71
Commercial Real Estate | Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	55	263
Commercial Real Estate | Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	26
Commercial Real Estate | Accruing Loans | Income Producing | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		4
Commercial Real Estate | Accruing Loans | Income Producing | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	26
Commercial Real Estate | Accruing Loans | Land and Development | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	55	259
Commercial Real Estate | Non-Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		341
Commercial Real Estate | Non-Accruing Loans | Land and Development | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		341
Consumer | Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	3,723	3,462
Consumer | Accruing Loans | 30-59 DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	3,191	2,910
Consumer | Accruing Loans | 30-59 DPD | Other
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	532	552
Consumer | Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	1,033	1,078
Consumer | Accruing Loans | 60-89 DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	1,030	1,078
Consumer | Accruing Loans | 60-89 DPD | Other
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	3
Consumer | Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	325	499
Consumer | Accruing Loans | 90+DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	325	496
Consumer | Accruing Loans | 90+DPD | Other
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		3
Consumer | Non-Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	173	30
Consumer | Non-Accruing Loans | 30-59 DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	173	30
Consumer | Non-Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	293
Consumer | Non-Accruing Loans | 60-89 DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	293
Consumer | Non-Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	2,205	2,073
Consumer | Non-Accruing Loans | 90+DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	2,205	2,073
Consumer | Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	1,070	1,427
Consumer | Non-Accruing Loans | 0-29 DPD | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	1,070	1,427
Small Business Lending | Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	931	2,003
Small Business Lending | Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	328	563
Small Business Lending | Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		87
Small Business Lending | Non-Accruing Loans | 30-59 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	38	78
Small Business Lending | Non-Accruing Loans | 60-89 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due		36
Small Business Lending | Non-Accruing Loans | 90+DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	494	131
Small Business Lending | Non-Accruing Loans | 0-29 DPD
Financing Receivable Recorded Investment Past Due [Line Items]
Loans Past Due	$ 110	$ 560

Loans and Allowance for Credi74

Loans and Allowance for Credit Losses - Summary of Changes in Accretable Discount for ACI Loans (Details) - ACI Loans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Recorded Investment [Line Items]
Balance at beginning of period	$ 98,728	$ 122,791	$ 163,631
Maturities/payoff	(9,888)	(11,563)	(24,196)
Charge-offs	(129)	(286)	(183)
Foreclosure	(1,061)	(1,041)	(1,290)
Accretion	(23,303)	(30,870)	(46,042)
Reclass from nonaccretable difference due to increases in expected cash flow	14,075	19,697	30,871
Balance at end of period	$ 78,422	$ 98,728	$ 122,791

Loans and Allowance for Credi75

Loans and Allowance for Credit Losses - Summary of Individually Impaired ACI Loans and Pooled ACI Loans (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Financing Receivable Impaired [Line Items]
Recorded Investment in Impaired Loans		$ 278,587	$ 371,673
Commercial and Industrial
Financing Receivable Impaired [Line Items]
Recorded Investment in Impaired Loans		252,600	360,235
Commercial Real Estate
Financing Receivable Impaired [Line Items]
Recorded Investment in Impaired Loans		46	364
Consumer
Financing Receivable Impaired [Line Items]
Recorded Investment in Impaired Loans		21,059	7,376
ACI Loans and Pooled ACI Loans
Financing Receivable Impaired [Line Items]
Recorded Investment in Impaired Loans	[1]	115,000	113,275
Unpaid Principal Balance		152,024	161,377
Related Specific Allowance		8,524	10,277
Nonaccrual Loans Included in Impaired Loans		225	3,663
Undisbursed Commitments			1,228
ACI Loans and Pooled ACI Loans | Commercial and Industrial
Financing Receivable Impaired [Line Items]
Recorded Investment in Impaired Loans	[1]	13,541	15,552
Unpaid Principal Balance		17,630	28,256
Related Specific Allowance		5	176
Nonaccrual Loans Included in Impaired Loans			1,818
ACI Loans and Pooled ACI Loans | Commercial Real Estate
Financing Receivable Impaired [Line Items]
Recorded Investment in Impaired Loans	[1]	82,856	53,428
Unpaid Principal Balance		112,330	82,946
Related Specific Allowance		2,010	2,654
Nonaccrual Loans Included in Impaired Loans		225	1,845
Undisbursed Commitments			1,213
ACI Loans and Pooled ACI Loans | Consumer
Financing Receivable Impaired [Line Items]
Recorded Investment in Impaired Loans	[1]	18,603	44,295
Unpaid Principal Balance		22,064	50,175
Related Specific Allowance		$ 6,509	7,447
Undisbursed Commitments			$ 15
[1]	The recorded investment of a loan also includes any interest receivable, net unearned discount or fees, and unamortized premium or discount.

Loans and Allowance for Credi76

Loans and Allowance for Credit Losses - Summary of Consumer Credit Exposure on ACI loans, Based on Past Due Status (Details) - ACI Loans - Consumer - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Residential Real Estate
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due	$ 152,336	$ 189,003
Residential Real Estate | 0-29 DPD
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due	139,662	171,457
Residential Real Estate | 30-59 DPD
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due	2,299	4,070
Residential Real Estate | 60-89 DPD
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due	2,496	1,939
Residential Real Estate | Financing Receivables 90 to 119 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due	399	622
Residential Real Estate | Financing Receivables 120 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due	7,480	10,915
Other
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due	1,583	2,122
Other | 0-29 DPD
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due	1,356	1,871
Other | 30-59 DPD
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due	120	134
Other | 60-89 DPD
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due	62	25
Other | Financing Receivables 90 to 119 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due		36
Other | Financing Receivables 120 Days Past Due
Accounts Notes And Loans Receivable [Line Items]
Loans Past Due	$ 45	$ 56

Premises and Equipment - Compon

Premises and Equipment - Components of Premises and Equipment (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Gross premises and equipment		$ 104,618	$ 101,122
Less: Accumulated depreciation and amortization		(41,186)	(34,446)
Total premises and equipment, net		63,432	66,676
Land
Property, Plant and Equipment [Line Items]
Gross premises and equipment		16,875	16,875
Buildings, construction and improvements
Property, Plant and Equipment [Line Items]
Gross premises and equipment	[1]	$ 53,620	52,263
Buildings, construction and improvements | Minimum
Property, Plant and Equipment [Line Items]
Premises and equipment, Estimated Useful Life in Years	[1]	2 years
Buildings, construction and improvements | Maximum
Property, Plant and Equipment [Line Items]
Premises and equipment, Estimated Useful Life in Years	[1]	40 years
Land, Buildings and Improvements
Property, Plant and Equipment [Line Items]
Gross premises and equipment		$ 70,495	69,138
Equipment
Property, Plant and Equipment [Line Items]
Gross premises and equipment		$ 34,123	$ 31,984
Equipment | Minimum
Property, Plant and Equipment [Line Items]
Premises and equipment, Estimated Useful Life in Years		3 years
Equipment | Maximum
Property, Plant and Equipment [Line Items]
Premises and equipment, Estimated Useful Life in Years		10 years
[1]	Leasehold improvements are depreciated over the lesser of the estimated useful life or the lease term.

Premises and Equipment - Additi

Premises and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Amount charged to operating expenses for depreciation	$ 7,100	$ 6,700	$ 7,200
Amount charged to operating expenses for software amortization	4,652	6,532	8,428
Software Costs
Net Software cost included in other asset	4,000	3,400
Premises And Equipment
Rental expenses for premises and equipment	11,200	11,100	13,400
Software Amortization
Amount charged to operating expenses for software amortization	$ 1,900	$ 1,700	$ 1,800

Premises and Equipment - Future

Premises and Equipment - Future Minimum Lease Payments under Operating Leases (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Operating Leased Assets [Line Items]
2,018	$ 10,066
2,019	9,729
2,020	8,588
2,021	7,794
2,022	5,575
Thereafter	8,949
Total minimum lease payments	50,701
Property
Operating Leased Assets [Line Items]
2,018	9,724
2,019	9,542
2,020	8,544
2,021	7,794
2,022	5,575
Thereafter	8,949
Total minimum lease payments	50,128
Equipment
Operating Leased Assets [Line Items]
2,018	342
2,019	187
2,020	44
Total minimum lease payments	$ 573

Goodwill and Other Intangible80

Goodwill and Other Intangible Assets - Summary of Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Goodwill And Other Intangible Assets [Line Items]
Goodwill	$ 317,817	$ 317,817
Other intangible assets, net	10,223	14,874
Total goodwill and intangible assets	328,040	332,691
Core Deposit
Goodwill And Other Intangible Assets [Line Items]
Other intangible assets, net	1,595	4,191
Customer Lists
Goodwill And Other Intangible Assets [Line Items]
Other intangible assets, net	8,604	10,659
Trademarks
Goodwill And Other Intangible Assets [Line Items]
Other intangible assets, net	$ 24	$ 24

Goodwill and Other Intangible81

Goodwill and Other Intangible Assets - Summary of Goodwill and Other Intangible Assets (Parenthetical) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Core Deposit
Goodwill And Other Intangible Assets [Line Items]
Accumulated amortization of intangible assets	$ 38,091	$ 35,495
Customer Lists
Goodwill And Other Intangible Assets [Line Items]
Accumulated amortization of intangible assets	$ 18,097	$ 16,041

Derivatives - Schedule of Notio

Derivatives - Schedule of Notional Amounts and Estimated Fair Values (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 29, 2017	Dec. 31, 2016
Derivatives Fair Value [Line Items]
Notional Amount	$ 2,350,759		$ 2,163,167
Fair Value, Other Assets	3,958		4,361
Fair Value, Other Liabilities	25,280		20,360
Interest Rate Swaps
Derivatives Fair Value [Line Items]
Notional Amount		$ 300,000
Derivatives Designated as Hedging Instruments | Cash Flow Hedges | Commercial Loans | Interest Rate Swaps
Derivatives Fair Value [Line Items]
Notional Amount	1,032,000		1,332,000
Fair Value, Other Assets			1,184
Fair Value, Other Liabilities	21,394		17,225
Derivatives Not Designated as Hedging Instruments
Derivatives Fair Value [Line Items]
Notional Amount	1,318,759		831,167
Fair Value, Other Assets	3,958		3,177
Fair Value, Other Liabilities	3,886		3,135
Derivatives Not Designated as Hedging Instruments | Mortgage Loan Held for Sale Interest Rate Lock Commitments
Derivatives Fair Value [Line Items]
Notional Amount	6,119		3,788
Fair Value, Other Assets	50		88
Derivatives Not Designated as Hedging Instruments | Mortgage Loan Held for Sale Floating Commitments
Derivatives Fair Value [Line Items]
Notional Amount	11,800		5,895
Derivatives Not Designated as Hedging Instruments | Foreign Exchange Contracts
Derivatives Fair Value [Line Items]
Notional Amount	41,688
Fair Value, Other Assets	635
Fair Value, Other Liabilities	623
Derivatives Not Designated as Hedging Instruments | Commercial Loans | Interest Rate Swaps
Derivatives Fair Value [Line Items]
Notional Amount	737,533		474,923
Fair Value, Other Assets	2,056		2,877
Fair Value, Other Liabilities	2,056		2,877
Derivatives Not Designated as Hedging Instruments | Commercial Loans | Interest Rate Caps
Derivatives Fair Value [Line Items]
Notional Amount	186,290		286,959
Fair Value, Other Assets	153		94
Fair Value, Other Liabilities	153		94
Derivatives Not Designated as Hedging Instruments | Commercial Loans | Interest Rate Floors
Derivatives Fair Value [Line Items]
Notional Amount	330,764		51,878
Fair Value, Other Assets	1,054		118
Fair Value, Other Liabilities	1,054		118
Derivatives Not Designated as Hedging Instruments | Forward Contracts | Mortgage Loan Forward Sale Commitments
Derivatives Fair Value [Line Items]
Notional Amount	4,565		7,724
Fair Value, Other Assets	$ 10
Fair Value, Other Liabilities			$ 46

Derivatives - Additional Inform

Derivatives - Additional Information (Details) - USD ($) $ in Thousands	Dec. 29, 2017	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Derivative notional amount		$ 2,350,759	$ 2,163,167
Deferred net gains (loss) on derivatives		$ (6,400)
Cash Flow Hedges
Derivative [Line Items]
Maximum period for hedging transactions		8 years
Interest Rate Swaps
Derivative [Line Items]
Derivative, maturity date	Dec. 29, 2017
Derivative notional amount	$ 300,000
Interest-bearing Deposits in Banks
Derivative [Line Items]
Cash or securities pledged as collateral		$ 20,100	$ 20,300

Derivatives - Schedule of Gain

Derivatives - Schedule of Gain (Loss) in Consolidated Statements of Income Related to Derivative Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments Gain Loss [Line Items]
Noninterest income	$ 6,400
Derivatives Designated as Hedging Instruments | Cash Flow Hedges | Commercial Loans | Interest Rate Swaps
Derivative Instruments Gain Loss [Line Items]
OCI	(1,426)	$ (7,444)	$ 7,454
Reclassified from AOCI to interest income	3,705	11,255	4,877
Noninterest income		166	(329)
Derivatives Not Designated as Hedging Instruments | Mortgage Loan Held for Sale Interest Rate Lock Commitments
Derivative Instruments Gain Loss [Line Items]
Noninterest income	(39)	24	(66)
Derivatives Not Designated as Hedging Instruments | Foreign Exchange Contracts
Derivative Instruments Gain Loss [Line Items]
Noninterest income	$ 2,271	$ 1,264	$ 965

Derivative - Schedule of Intere

Derivative - Schedule of Interest Rate Swap Agreements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Notional Amount	$ 2,350,759	$ 2,163,167
1.3250% Interest Rate Swap
Derivative [Line Items]
Effective Date	Jun. 15, 2015
Maturity Date	Dec. 17, 2018
Notional Amount	$ 382,000
Fixed Rate	1.325%
Variable Rate	1 Month LIBOR
1.5120% Interest Rate Swap
Derivative [Line Items]
Effective Date	Jun. 30, 2015
Maturity Date	Dec. 31, 2019
Notional Amount	$ 300,000
Fixed Rate	1.512%
Variable Rate	1 Month LIBOR
1.5995% Interest Rate Swap
Derivative [Line Items]
Effective Date	Mar. 8, 2016
Maturity Date	Feb. 27, 2026
Notional Amount	$ 175,000
Fixed Rate	1.5995%
Variable Rate	1 Month LIBOR
1.5890% Interest Rate Swap
Derivative [Line Items]
Effective Date	Mar. 8, 2016
Maturity Date	Feb. 27, 2026
Notional Amount	$ 175,000
Fixed Rate	1.589%
Variable Rate	1 Month LIBOR

Deposits - Additional Informati

Deposits - Additional Information (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Deposits Disclosure [Line Items]
Time Deposits	$ 1,916,337,000
Domestic
Deposits Disclosure [Line Items]
Time deposits $250,000 and over	382,400,000	$ 318,800,000
Foreign
Deposits Disclosure [Line Items]
Time Deposits	$ 0	$ 0

Deposits - Scheduled Maturities

Deposits - Scheduled Maturities Of Time Deposits Included In Interest-Bearing Deposits (Details) $ in Thousands	Dec. 31, 2017USD ($)
Deposits [Abstract]
2,018	$ 1,284,285
2,019	515,511
2,020	89,364
2,021	16,678
2,022	10,455
Thereafter	44
Total	$ 1,916,337

Borrowed Funds - Additional Inf

Borrowed Funds - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Mar. 31, 2015	Jun. 30, 2014	Dec. 31, 2017	Dec. 31, 2016
Borrowed Funds [Line Items]
Unregistered multi tranche debt Transactions		$ 245,000
Unregistered debt transactions	$ 50,000
Subordinated debt			$ 98,687	$ 98,441
Subordinate debt capital treatment achievement period			10 years
FHLB advances			$ 150,000	0
FHLB advances maturity period			2018-01
Irrevocable letter of credit			$ 386,500	386,500
FRB
Borrowed Funds [Line Items]
Borrowings from FRB			0	$ 0
SAFE Program Deposits
Borrowed Funds [Line Items]
Irrevocable letter of credit			$ 35,000
Letter of credit expiration date			Sep. 27, 2018
Letter of credit expiration period			45 days
Letter of credit extended expiration term			1 year
Treasury Management Deposit
Borrowed Funds [Line Items]
Irrevocable letter of credit			$ 350,000
Letter of credit expiration date			May 26, 2018
Letter of credit expiration period			45 days
Letter of credit extended expiration term			1 year
Commercial Loans | FRB
Borrowed Funds [Line Items]
Collateralized borrowings from FRB			$ 738,400
Commercial and Residential Real Estate Loan
Borrowed Funds [Line Items]
FHLB advances collateral amount			$ 1,400,000
4.875% Senior Notes, Due June 28, 2019
Borrowed Funds [Line Items]
Subordinated debt maturity period			4 years
5.375% Senior Notes, Due June 28, 2021
Borrowed Funds [Line Items]
Subordinated debt maturity period			7 years
7.250% Subordinated Notes, Due June 28, 2029, Callable in 2024
Borrowed Funds [Line Items]
Subordinated debt maturity period			15 years
Subordinated debt			$ 35,000
Call option period			10 years
6.250% Subordinated Notes, Due June 28, 2029, Callable in 2024
Borrowed Funds [Line Items]
Subordinated debt maturity period			15 years
Subordinated debt			$ 25,000
Call option period			10 years
6.500% Subordinated Notes, Due March 2025, Callable in 2020
Borrowed Funds [Line Items]
Subordinated debt			$ 40,000
Call option period			5 years
Minimum
Borrowed Funds [Line Items]
Repurchase agreement maturity period			P1D
Maximum
Borrowed Funds [Line Items]
Repurchase agreement maturity period			seven days

Borrowed Funds - Summary of Sec

Borrowed Funds - Summary of Securities Sold Under Agreements to Repurchase (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Balance at period end	$ 1,026,000	$ 3,494,000
Average balance during the period	$ 3,371,000	$ 5,948,000
Average interest rate during the period	0.25%	0.19%
Maximum month-end balance during the period	$ 6,286,000	$ 8,031,000

Borrowed Funds - Summary of Deb

Borrowed Funds - Summary of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Debt issuance cost and unamortized premium	$ (1,606)	$ (2,693)
Total long-term debt	283,316	292,229
4.875% Senior Notes, Due June 28, 2019
Debt Instrument [Line Items]
Purchased senior notes	(10,078)	(78)
Cadence Bancorporation
Debt Instrument [Line Items]
Long-term debt, gross	270,000	270,000
Cadence Bancorporation | 4.875% Senior Notes, Due June 28, 2019
Debt Instrument [Line Items]
Long-term debt, gross	145,000	145,000
Cadence Bancorporation | 5.375% Senior Notes, Due June 28, 2021
Debt Instrument [Line Items]
Long-term debt, gross	50,000	50,000
Cadence Bancorporation | 7.250% Subordinated Notes, Due June 28, 2029, Callable in 2024
Debt Instrument [Line Items]
Long-term debt, gross	35,000	35,000
Cadence Bancorporation | 6.500% Subordinated Notes, Due March 2025, Callable in 2020
Debt Instrument [Line Items]
Long-term debt, gross	40,000	40,000
Cadence Bank | 6.250% Subordinated Notes, Due June 28, 2029, Callable in 2024
Debt Instrument [Line Items]
Long-term debt, gross	$ 25,000	$ 25,000

Borrowed Funds - Summary of D91

Borrowed Funds - Summary of Debt (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
4.875% Senior Notes, Due June 28, 2019
Debt Instrument [Line Items]
Debt instrument, interest rate	4.875%	4.875%
Debt instrument, maturity date	Jun. 28, 2019	Jun. 28, 2019
5.375% Senior Notes, Due June 28, 2021
Debt Instrument [Line Items]
Debt instrument, interest rate	5.375%	5.375%
Debt instrument, maturity date	Jun. 28, 2021	Jun. 28, 2021
7.250% Subordinated Notes, Due June 28, 2029, Callable in 2024
Debt Instrument [Line Items]
Debt instrument, interest rate	7.25%	7.25%
Debt instrument, maturity date	Jun. 28, 2029	Jun. 28, 2029
6.500% Subordinated Notes, Due March 2025, Callable in 2020
Debt Instrument [Line Items]
Debt instrument, interest rate	6.50%	6.50%
Debt instrument, maturity date	Mar. 31, 2025	Mar. 31, 2025
6.250% Subordinated Notes, Due June 28, 2029, Callable in 2024
Debt Instrument [Line Items]
Debt instrument, interest rate	6.25%	6.25%
Debt instrument, maturity date	Jun. 28, 2029	Jun. 28, 2029

Borrowed Funds - Summary of Jun

Borrowed Funds - Summary of Junior Subordinated Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Junior subordinated debentures, gross	$ 50,619	$ 50,619
Purchase accounting adjustment, net of amortization	(14,147)	(14,630)
Total junior subordinated debentures	36,472	35,989
3 month LIBOR plus 2.85%, due 2033
Debt Instrument [Line Items]
Junior subordinated debentures, gross	30,000	30,000
3 month LIBOR plus 2.95%, due 2033
Debt Instrument [Line Items]
Junior subordinated debentures, gross	5,155	5,155
3 month LIBOR plus 1.75%, due 2037
Debt Instrument [Line Items]
Junior subordinated debentures, gross	$ 15,464	$ 15,464

Borrowed Funds - Summary of J93

Borrowed Funds - Summary of Junior Subordinated Debt (Parenthetical) (Details) - Junior subordinated debt	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
3 month LIBOR plus 2.85%, due 2033
Debt Instrument [Line Items]
Debt instrument, interest rate	2.85%	2.85%
Debt instrument maturity year	2,033	2,033
3 month LIBOR plus 2.95%, due 2033
Debt Instrument [Line Items]
Debt instrument, interest rate	2.95%	2.95%
Debt instrument maturity year	2,033	2,033
3 month LIBOR plus 1.75%, due 2037
Debt Instrument [Line Items]
Debt instrument, interest rate	1.75%	1.75%
Debt instrument maturity year	2,037	2,037

Other Noninterest Income and 94

Other Noninterest Income and Other Noninterest Expense - Summary of Other Noninterest Income and Other Noninterest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other noninterest income
Insurance revenue	$ 7,378	$ 7,717	$ 7,107
Bankcard fees	7,310	7,270	7,213
Income from bank owned life insurance policies	3,313	2,954	2,994
Other	6,655	(263)	(2,297)
Total other noninterest income	24,656	17,678	15,017
Other noninterest expense
Net cost of operation of other real estate owned	2,251	3,033	5,238
Data processing expense	7,590	6,280	6,092
Special asset expenses	1,156	1,788	3,000
Consulting and professional fees	9,090	6,728	5,671
Loan related expenses	2,379	3,114	3,745
FDIC insurance	4,275	7,228	5,027
Communications	2,837	2,656	3,249
Advertising and public relations	2,048	1,369	2,295
Legal expenses	4,178	2,721	3,159
Branch closure expenses	198	238	2,074
Other	24,663	25,443	26,306
Total other noninterest expense	$ 60,665	$ 60,598	$ 65,856

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Statutory Federal income tax rate		35.00%	35.00%
Write-off of net deferred tax asset		$ 19,000,000
Provisional income tax expense relating to from Tax Reform		19,000,000
Realization of deferred tax asset		30,774,000	$ 83,662,000
Future taxable income		169,900,000
Unrecognized tax benefits that would impact effective tax rate		581,100	614,000
Interest and penalties recognized		(4,000)	90,000
Accrued interest and penalties on unrecognized tax benefits		88,000	$ 90,000
U.S. Federal
Income Tax Disclosure [Abstract]
Net operating loss carryforwards		$ 41,100,000
Federal net operating loss carry forward expiration year		2,031
State and Local Jurisdiction [Member]
Income Tax Disclosure [Abstract]
Net operating loss carryforwards		$ 27,900,000
Federal net operating loss carry forward expiration year		2,022
ATM
Income Tax Disclosure [Abstract]
AMT credit carryforward		$ 978,000
Scenario Plan
Income Tax Disclosure [Abstract]
Statutory Federal income tax rate	21.00%

Income Taxes - Components of th

Income Taxes - Components of the Consolidated Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal									$ 33,799	$ 24,394	$ 22,024
State									2,458	2,166	1,013
Total current expense									36,257	26,560	23,037
Deferred:
Federal									44,009	5,439	(3,266)
State									380	541	338
Total deferred (benefit) expense									44,389	5,980	(2,928)
Total income tax expense	$ 36,980	$ 17,457	$ 13,570	$ 12,639	$ 15,701	$ 2,107	$ 7,175	$ 7,557	$ 80,646	$ 32,540	$ 20,109

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Total Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Computed income tax expense at statutory rate									$ 64,050	$ 34,410	$ 20,778
Effects of tax reform									19,022
Tax exempt interest, net									(3,988)	(2,744)	(842)
BOLI income									(1,148)	(1,023)	(1,037)
State tax expense									2,279	1,760	878
Tax credits									(384)	(266)	(243)
Management compensation									116	210	353
Other, net									699	193	222
Total income tax expense	$ 36,980	$ 17,457	$ 13,570	$ 12,639	$ 15,701	$ 2,107	$ 7,175	$ 7,557	$ 80,646	$ 32,540	$ 20,109

Income Taxes - Significant Comp

Income Taxes - Significant Components of the Company's Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred income tax assets:
Allowance for credit losses	$ 18,464	$ 30,710
Nonaccrual interest		7,410
Deferred compensation	3,440	3,681
Accrued compensation	2,506	7,962
Net operating loss carryforwards	9,859	16,154
Alternative minimum tax credit carryover	978	978
Unrealized loss on securities, net	1,271	13,829
Unrealized loss on derivative instruments	4,912	5,911
Other	5,344	9,320
Excess of tax basis in assets acquired:
Loans	841	8,673
Other real estate owned	13	1,342
Other		4
Total deferred income tax assets	47,628	105,974
Deferred income tax liabilities:
Difference in book and tax basis of intangibles	1,927	4,268
Other	4,213	4,564
Excess of book basis in assets acquired and tax liabilities assumed over book carrying value:
Intangibles	7,122	7,798
Other	3,592	5,682
Total deferred income tax liabilities	16,854	22,312
Net deferred income tax asset	$ 30,774	$ 83,662

Income Taxes - Reconciliation99

Income Taxes - Reconciliation of the Beginning and Ending Amount of Unrecognized Income Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Unrecognized income tax benefits, January 1	$ 944
Increases for tax positions related to prior years	9	$ 422	$ 0
Increases for tax positions related to current year	394	522	0
Decreases for tax positions related to prior years	(453)	0	0
Decreases for tax positions related to current year	0	0	0
Settlement with taxing authorities	0	0	0
Expiration of applicable statutes of limitations	0	0	$ 0
Unrecognized income tax benefits, December 31	$ 894	$ 944

Earnings Per Common Share - Rec

Earnings Per Common Share - Reconciliation of Basic and Diluted Net Income Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income	$ 14,691	$ 32,577	$ 28,968	$ 26,117	$ 28,986	$ 6,607	$ 14,840	$ 15,341	$ 102,353	$ 65,774	$ 39,256
Weighted average common shares outstanding (Basic)									81,072,945	75,000,000	75,000,000
Weighted average restricted stock units									532,070	294,600	116,100
Weighted average common shares outstanding (Diluted)									81,605,015	75,294,600	75,116,100
Earnings per common share (Basic)	$ 0.18	$ 0.39	$ 0.35	$ 0.35	$ 0.39	$ 0.09	$ 0.20	$ 0.20	$ 1.26	$ 0.88	$ 0.52
Earnings per common share (Diluted)	$ 0.17	$ 0.39	$ 0.35	$ 0.35	$ 0.38	$ 0.09	$ 0.20	$ 0.20	$ 1.25	$ 0.87	$ 0.52

Earnings Per Common Share - Add

Earnings Per Common Share - Additional Information (Details)	Apr. 07, 2017	Dec. 31, 2017
Earnings Per Share [Abstract]
Stock split ratio		75-for-one
Stock split, shares	75

Employee Benefits - Additional

Employee Benefits - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Prior service cost or loss amortization	$ 0
Amount recognized in accumulated other comprehensive income, expected to be recognized as a component of net periodic benefit cost in 2018	$ 44,000
Asset Allocations	100.00%	100.00%
Minimum cash contribution	$ 1,300,000	$ 900,000	$ 0
Amount recognized in compensation expense	139,118,000	125,068,000	128,267,000
Plan 401 K [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan contributions	3,500,000	3,400,000
Plan 401 K [Member] | Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued liability	1,900,000	1,900,000
Amount recognized in compensation expense	706,000	322,000	104,000
Plan 401 K [Member] | Unqualified Supplemental Retirement and Voluntary Deferred Compensation Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued liability	3,200,000
Amount recognized in compensation expense	47,000	$ 186,000	$ 102,000
Deferred compensation	$ 3,200,000
Scenario, Forecast [Member] | Minimum
Defined Benefit Plan Disclosure [Line Items]
Minimum cash contribution				$ 0
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset Allocations	55.00%	55.00%
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset Allocations	39.00%	41.00%
Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset Allocations	6.00%	4.00%

Employee Benefits - Defined Ben

Employee Benefits - Defined Benefit Pension Plan's Funded (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 100,000	$ 100,000	$ 100,000
Interest cost	192,000	221,000	232,000
Fair value of plan assets at beginning of period	4,689,000
Employer contributions	1,300,000	900,000	0
Fair value of plan assets at end of year	6,130,000	4,689,000
Expected return on plan assets	(261,000)	(234,000)	(278,000)
Net loss amortization	65,000	53,000	61,000
Cost of settlements	45,000	156,000	155,000
Net periodic benefit cost	141,000	296,000	270,000
Amortization of net actuarial loss	65,000	53,000	61,000
Net actuarial loss	48,000	(226,000)	(35,000)
Adjustment for settlement	45,000	156,000	155,000
Gains (losses) on pension liability	158,000	(17,000)	181,000
Tax effect	(37,000)	4,000	(69,000)
Net unrealized (losses) gains on pension liability	121,000	(13,000)	112,000
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of period	5,785,000	6,176,000
Service cost	100,000	100,000
Interest cost	192,000	221,000
Actuarial loss	224,000	233,000
Administrative expenses paid	(40,000)	(59,000)
Benefits paid	(77,000)	(79,000)
Settlements	(275,000)	(807,000)
Benefit obligation at end of year	5,909,000	5,785,000	6,176,000
Fair value of plan assets at beginning of period	4,689,000	4,464,000
Return on plan assets	533,000	240,000
Employer contributions	1,300,000	930,000
Administrative expenses paid	(40,000)	(59,000)
Benefits paid	(77,000)	(79,000)
Settlements	(275,000)	(807,000)
Fair value of plan assets at end of year	6,130,000	4,689,000	$ 4,464,000
Funded status	$ 221,000	$ (1,096,000)

Employee Benefits - Determine B

Employee Benefits - Determine Benefit Obligations and Net Periodic Pension Cost (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Postemployment Benefits [Abstract]
Discount rate	3.21%	3.52%	3.76%
Compensation increase rate	0.00%	0.00%	0.00%
Census date	Jan. 1, 2018	Jan. 1, 2017	Jan. 1, 2016
Expected return on plan assets	5.50%	5.50%	5.50%

Employee Benefits - Schedule of

Employee Benefits - Schedule of Expected Benefit Payments (Details) - Pension Plan [Member] $ in Thousands	Dec. 31, 2017USD ($)
Defined Benefit Plan Disclosure [Line Items]
2,018	$ 823
2,019	514
2,020	734
2,021	1,019
2,022	370
2023-2027	1,830
Total	$ 5,290

Employee Benefits - Schedule106

Employee Benefits - Schedule of Defined Benefit Pension Plan Fair Values and Weighted-Average Asset Allocations by Asset Category (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 6,130	$ 4,689
Asset Allocations	100.00%	100.00%
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 2,382	$ 1,912
Asset Allocations	39.00%	41.00%
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 3,342	$ 2,594
Asset Allocations	55.00%	55.00%
Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		$ 183
Asset Allocations	6.00%	4.00%
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 406
Asset Allocations	6.00%

Employee Benefits - Schedule107

Employee Benefits - Schedule of Projected Benefit Payments (Details) - Plan 401 K [Member] $ in Thousands	Dec. 31, 2017USD ($)
Defined Benefit Plan Disclosure [Line Items]
2,018	$ 171
2,019	375
2,020	376
2,021	384
2,022	451
2023-2027	2,299
Total	$ 4,056

Regulatory Matters - Schedule o

Regulatory Matters - Schedule of Actual Capital Amounts and Ratios (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 leverage	$ 1,096,438	$ 824,676
Common equity tier 1 capital (transitional)	1,058,888	793,268
Tier 1 risk-based capital	1,096,438	824,676
Total risk-based capital	1,283,561	1,007,011
Tier 1 leverage	410,770	371,052
Common equity tier 1 capital (transitional)	450,951	403,718
Tier 1 risk-based capital	601,269	538,290
Total risk-based capital	$ 801,691	$ 717,720
Tier 1 leverage	10.70%	8.90%
Common equity tier 1 capital (transitional)	10.60%	8.80%
Tier 1 risk-based capital	10.90%	9.20%
Total risk-based capital	12.80%	11.20%
Tier 1 leverage	4.00%	4.00%
Common equity tier 1 capital (transitional)	4.50%	4.50%
Tier 1 risk-based capital	6.00%	6.00%
Total risk-based capital	8.00%	8.00%
Cadence Bank
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 leverage	$ 1,198,234	$ 1,035,972
Common equity tier 1 capital (transitional)	1,149,181	989,990
Tier 1 risk-based capital	1,198,234	1,035,972
Total risk-based capital	1,311,376	1,144,519
Tier 1 leverage	410,743	370,836
Common equity tier 1 capital (transitional)	450,874	403,578
Tier 1 risk-based capital	601,165	538,105
Total risk-based capital	801,553	717,473
Tier 1 leverage	513,429	463,546
Common equity tier 1 capital (transitional)	651,262	583,248
Tier 1 risk-based capital	801,553	717,844
Total risk-based capital	$ 1,001,941	$ 897,305
Tier 1 leverage	11.70%	11.20%
Common equity tier 1 capital (transitional)	11.50%	11.00%
Tier 1 risk-based capital	12.00%	11.50%
Total risk-based capital	13.10%	12.80%
Tier 1 leverage	4.00%	4.00%
Common equity tier 1 capital (transitional)	4.50%	4.50%
Tier 1 risk-based capital	6.00%	6.00%
Total risk-based capital	8.00%	8.00%
Tier 1 leverage	5.00%	5.00%
Common equity tier 1 capital (transitional)	6.50%	6.50%
Tier 1 risk-based capital	8.00%	8.00%
Total risk-based capital	10.00%	10.00%

Regulatory Matters - Additional

Regulatory Matters - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Banking And Thrift [Abstract]
Reserve requirement with FRB	$ 70.9	$ 38.3

Commitments and Contingent L110

Commitments and Contingent Liabilities - Summary of Commitments and Contingent Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Standby Letters of Credit
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Letters of credit	$ 101,718	$ 120,532
Performance Letters of Credit
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Performance letters of credit	17,638	29,270
Commercial Letters of Credit
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Letters of credit	11,790
Commitments to Extend Credit
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Commitments to extend credit	$ 3,270,097	$ 2,643,501

Commitments and Contingent L111

Commitments and Contingent Liabilities - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Contingent commitments to grant loans	$ 523
Unfunded commitments - LLC Investments	$ 20.3	$ 15.1

Supplemental Cash Flow Infor112

Supplemental Cash Flow Information - Summary of Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash paid during the year for:
Interest	$ 69,289	$ 55,086	$ 44,333
Income taxes, net of refunds	33,268	23,025	22,139
Non-cash investing activities (at fair value):
Transfers of loans to other real estate	7,023	13,494	11,800
Transfers of commercial loans to loans held for sale	$ 16,206	318,868	$ 19,400
Transfers of loans to other assets (net profits interest)		$ 19,104

Disclosure About Fair Values113

Disclosure About Fair Values of Financial Instruments - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	$ 1,262,948	$ 1,139,347
Derivative assets	3,958	4,361
Derivative liabilities	25,280	20,360
Carrying Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	1,262,948	1,139,347
Derivative assets	3,985	4,361
Other assets (Net profits interests)	15,833	19,425
Derivative liabilities	25,307	20,360
U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	96,844	96,785
Obligations of U.S. Government Agencies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	81,224	97,528
Other Residential Mortgage-Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	46,392	47,561
Commercial Mortgage-Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	72,195	62,613
Total MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	655,036	528,655
Obligations of States and Municipal Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	423,959	410,812
Other Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	5,885	5,567
Fair Value, Measurements, Recurring | Carrying Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	1,262,948	1,139,347
Derivative assets	3,985	4,361
Other assets (Net profits interests)	15,833	19,425
Total recurring basis measured assets	1,282,766	1,163,133
Derivative liabilities	25,307	20,360
Total recurring basis measured liabilities	25,307	20,360
Fair Value, Measurements, Recurring | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	5,885	5,567
Total recurring basis measured assets	5,885	5,567
Fair Value, Measurements, Recurring | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	1,257,063	1,133,780
Derivative assets	3,985	4,361
Total recurring basis measured assets	1,261,048	1,138,141
Derivative liabilities	25,307	20,360
Total recurring basis measured liabilities	25,307	20,360
Fair Value, Measurements, Recurring | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets (Net profits interests)	15,833	19,425
Total recurring basis measured assets	15,833	19,425
Fair Value, Measurements, Recurring | U.S. Treasury Securities | Carrying Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	96,844	96,785
Fair Value, Measurements, Recurring | U.S. Treasury Securities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	96,844	96,785
Fair Value, Measurements, Recurring | Obligations of U.S. Government Agencies | Carrying Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	81,224	97,528
Fair Value, Measurements, Recurring | Obligations of U.S. Government Agencies | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	81,224	97,528
Fair Value, Measurements, Recurring | Residential Pass-through | Guaranteed by GNMA | Carrying Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	106,027	153,153
Fair Value, Measurements, Recurring | Residential Pass-through | Issued by FNMA and FHLMC | Carrying Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	430,422	265,328
Fair Value, Measurements, Recurring | Residential Pass-through | Level 2 | Guaranteed by GNMA
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	106,027	153,153
Fair Value, Measurements, Recurring | Residential Pass-through | Level 2 | Issued by FNMA and FHLMC
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	430,422	265,328
Fair Value, Measurements, Recurring | Other Residential Mortgage-Backed Securities | Carrying Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	46,392	47,561
Fair Value, Measurements, Recurring | Other Residential Mortgage-Backed Securities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	46,392	47,561
Fair Value, Measurements, Recurring | Commercial Mortgage-Backed Securities | Carrying Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	72,195	62,613
Fair Value, Measurements, Recurring | Commercial Mortgage-Backed Securities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	72,195	62,613
Fair Value, Measurements, Recurring | Total MBS | Carrying Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	655,036	528,655
Fair Value, Measurements, Recurring | Total MBS | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	655,036	528,655
Fair Value, Measurements, Recurring | Obligations of States and Municipal Subdivisions | Carrying Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	423,959	410,812
Fair Value, Measurements, Recurring | Obligations of States and Municipal Subdivisions | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	423,959	410,812
Fair Value, Measurements, Recurring | Other Securities | Carrying Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	5,885	5,567
Fair Value, Measurements, Recurring | Other Securities | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investment securities available-for-sale	$ 5,885	$ 5,567

Disclosure About Fair Values114

Disclosure About Fair Values of Financial Instruments - Summary of Changes in Level 3 Assets Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Other Assets - Net Profits Interests, beginning balance	$ 19,425
Other Assets - Net Profits Interests, addition of net profits interest to other assets		$ 19,104
Other Assets - Net Profits Interests, total net gains (losses) included in earnings	(2,442)	407
Other Assets - Net Profits Interests, distributions received	(1,150)	(86)
Other Assets - Net Profits Interests, ending balance	15,833	19,425
Other Assets - Net Profits Interests, net unrealized (losses) gains included in earnings relating to assets held at the end of the period	$ (2,442)	$ 407

Disclosure About Fair Values115

Disclosure About Fair Values of Financial Instruments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017
Fair value inputs, increase (decrease) in discount rate	5.00%
Discounted Cash Flow | Net Recoverable Oil and Gas Reserves and Forward Looking Commodity Prices
Fair value inputs, discount rate	10.00%

Disclosure About Fair Values116

Disclosure About Fair Values of Financial Instruments - Summary of Assets Recorded at Fair Value on a Nonrecurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans, net of specific allowance	$ 278,587	$ 371,673
Other real estate	7,605	18,875
Fair Value, Nonrecurring
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Loans held for sale	61,359	17,822
Impaired loans, net of specific allowance	65,087	151,720
Other real estate	7,605	18,875
Total assets measured on a nonrecurring basis	134,051	188,417
Fair Value, Nonrecurring | Level 2
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Loans held for sale	61,359	17,822
Total assets measured on a nonrecurring basis	61,359	17,822
Fair Value, Nonrecurring | Level 3
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans, net of specific allowance	65,087	151,720
Other real estate	7,605	18,875
Total assets measured on a nonrecurring basis	$ 72,692	$ 170,595

Disclosure About Fair Values117

Disclosure About Fair Values of Financial Instruments - Summary of Significant Unobservable Inputs Used in Level 3 Fair Value Measurements for Financial Assets Measured at Fair Value On a Nonrecurring Basis (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Discounted Cash Flow | Net Recoverable Oil and Gas Reserves and Forward Looking Commodity Prices
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value inputs, discount rate		10.00%
Level 3 | Discount of Fair Value | Impaired Loans Net Of Specific Allowance
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value		$ 65,087	$ 151,720
Valuation Methods		Appraised value, as adjusted	Appraised value, as adjusted
Unobservable Inputs		Discount to fair value	Discount to fair value
Level 3 | Discount of Fair Value | Impaired Loans Net Of Specific Allowance | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range		0.00%	50.00%
Level 3 | Discount of Fair Value | Impaired Loans Net Of Specific Allowance | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range		50.00%	75.00%
Level 3 | Discount of Fair Value | Other
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value		$ 7,605	$ 18,875
Valuation Methods		Appraised value, as adjusted	Third-Party Appraisals
Unobservable Inputs		Discount to fair value	Discount of fair value
Level 3 | Discount of Fair Value | Other | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range		0.00%	0.00%
Level 3 | Discount of Fair Value | Other | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range		20.00%	20.00%
Level 3 | Discounted Cash Flow
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Valuation Methods		Discounted cash flow	Discounted cash flow
Unobservable Inputs		Discount rates - 3.6% to 8.0%	Discount rates - 3.8% to 12.5%
Level 3 | Discounted Cash Flow | Net Recoverable Oil and Gas Reserves and Forward Looking Commodity Prices
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Valuation Methods		Discounted cash flow	Discounted cash flow
Unobservable Inputs		Net recoverable oil and gas reserves and forward-looking commodity prices. Discount rate - 9%	Net recoverable oil and gas reserves and forward-looking commodity prices. Discount rate - 9%
Fair value inputs, discount rate		9.00%	9.00%
Level 3 | Discounted Cash Flow | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range	[1]	0.00%	0.00%
Fair value inputs, discount rate		3.60%	3.80%
Level 3 | Discounted Cash Flow | Minimum | Net Recoverable Oil and Gas Reserves and Forward Looking Commodity Prices
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range	[1]	0.00%	0.00%
Level 3 | Discounted Cash Flow | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range	[1]	1.00%	1.00%
Fair value inputs, discount rate		8.00%	12.50%
Level 3 | Discounted Cash Flow | Maximum | Net Recoverable Oil and Gas Reserves and Forward Looking Commodity Prices
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Range	[1]	29.00%	4.00%
Level 3 | Estimated Closing Costs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unobservable Inputs		Estimated closing costs	Estimated closing costs
Range		10.00%	10.00%
[1]	Represents fair value as a percent of the unpaid principal balance.

Disclosure About Fair Values118

Disclosure About Fair Values of Financial Instruments - Summary of Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financial Assets:
Interest-bearing deposits with banks	$ 482,568	$ 199,747
Federal funds sold	9,536	1,161
Securities available-for-sale	1,262,948	1,139,347
Estimated fair value of held-to-maturity securities	311	463
Derivative assets	3,958	4,361
Financial Liabilities:
FHLB advances	150,000	0
Securities sold under agreements to repurchase	1,026	3,494
Senior debt	184,629	193,788
Subordinated debt	98,687	98,441
Junior subordinated debentures	36,472	35,989
Derivative liabilities	25,280	20,360
Carrying Value
Financial Assets:
Cash and due from banks	238,707	48,017
Interest-bearing deposits with banks	482,568	199,747
Federal funds sold	9,536	1,161
Securities available-for-sale	1,262,948	1,139,347
Estimated fair value of held-to-maturity securities	290	425
Loans held for sale	61,359	17,822
Net loans	8,165,851	7,350,443
Derivative assets	3,985	4,361
Other assets-net profits interests	15,833	19,425
Financial Liabilities:
Deposits	9,011,515	8,016,749
FHLB advances	150,000
Securities sold under agreements to repurchase	1,026	3,494
Senior debt	184,629	193,788
Subordinated debt	98,687	98,441
Junior subordinated debentures	36,472	35,989
Derivative liabilities	25,307	20,360
Fair Value
Financial Assets:
Cash and due from banks	238,707	48,017
Interest-bearing deposits with banks	482,568	199,747
Federal funds sold	9,536	1,161
Securities available-for-sale	1,262,948	1,139,347
Estimated fair value of held-to-maturity securities	311	463
Loans held for sale	61,359	17,822
Net loans	8,134,903	7,395,003
Derivative assets	3,985	4,361
Other assets-net profits interests	15,833	19,818
Financial Liabilities:
Deposits	9,006,890	7,904,926
FHLB advances	150,000
Securities sold under agreements to repurchase	1,026	3,494
Senior debt	194,484	191,076
Subordinated debt	94,724	97,938
Junior subordinated debentures	49,161	47,409
Derivative liabilities	25,307	20,360
Fair Value | Level 1
Financial Assets:
Cash and due from banks	238,707	48,017
Interest-bearing deposits with banks	482,568	199,747
Federal funds sold	9,536	1,161
Securities available-for-sale	5,885	5,567
Fair Value | Level 2
Financial Assets:
Securities available-for-sale	1,257,063	1,133,780
Estimated fair value of held-to-maturity securities	311	463
Loans held for sale	61,359	17,822
Derivative assets	3,985	4,361
Financial Liabilities:
Deposits	9,006,890	7,904,926
FHLB advances	150,000
Securities sold under agreements to repurchase	1,026	3,494
Senior debt	194,484	191,076
Subordinated debt	94,724	97,938
Junior subordinated debentures	49,161	47,409
Derivative liabilities	25,307	20,360
Fair Value | Level 3
Financial Assets:
Net loans	8,134,903	7,395,003
Other assets-net profits interests	$ 15,833	$ 19,818

Variable Interest Entities a119

Variable Interest Entities and Other Investments - Additional Information (Details) - Variable Interest Entity, Not Primary Beneficiary	Dec. 31, 2017USD ($)Customer	Dec. 31, 2016USD ($)Customer
Variable Interest Entities and Other Investments [Line Items]
Cost method investments	$ 14,000,000	$ 6,100,000
Equity method investments	$ 8,800,000	$ 3,900,000
Number of loan customers | Customer	2	2
Net Profits interest	$ 15,800,000	$ 19,400,000
Rabbi Trust
Variable Interest Entities and Other Investments [Line Items]
Defined rabbi trust assets and benefit obligation	3,600,000	3,000,000
Other Assets
Variable Interest Entities and Other Investments [Line Items]
Investments in affordable Housing Project	$ 7,900,000	$ 4,200,000

Segment Reporting - Additional

Segment Reporting - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017Segment
Segment Reporting [Abstract]
Number of operating segments	3

Segment Reporting - Summary of

Segment Reporting - Summary of Operating Results of Segments (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2016		Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net interest income	$ 87,911		$ 81,163		$ 82,384		$ 74,758		$ 72,498		$ 70,426		$ 69,249		$ 67,266		$ 326,216	$ 279,439	$ 247,778
Provision for credit losses	(4,475)		1,723		6,701		5,786		(5,222)		29,627		14,471		10,472		9,735	49,348	35,984
Noninterest income	25,656	[1]	27,124	[1]	22,989	[1]	24,105	[1]	22,361	[2]	22,791	[2]	23,105	[2]	20,146	[2]	99,874	88,403	79,903
Noninterest expense	66,371		56,530		56,134		54,321		55,394		54,876		55,868		54,042		233,356	220,180	232,332
Income tax expense (benefit)	36,980		17,457		13,570		12,639		15,701		2,107		7,175		7,557		80,646	32,540	20,109
Net income	14,691		$ 32,577		$ 28,968		$ 26,117		28,986		$ 6,607		$ 14,840		$ 15,341		102,353	65,774	39,256
Total assets	10,948,926								9,530,888								10,948,926	9,530,888
Banking
Segment Reporting Information [Line Items]
Net interest income																	344,987	297,701	265,450
Provision for credit losses																	9,735	49,348	35,984
Noninterest income																	51,286	45,499	38,697
Noninterest expense																	194,212	186,874	200,544
Income tax expense (benefit)																	88,417	37,442	23,673
Net income																	103,909	69,536	43,946
Total assets	10,854,206								9,439,504								10,854,206	9,439,504
Financial Services
Segment Reporting Information [Line Items]
Net interest income																	(1,347)	(201)	(36)
Noninterest income																	47,956	42,727	40,964
Noninterest expense																	36,178	32,334	31,393
Income tax expense (benefit)																	2,000	3,567	3,337
Net income																	8,431	6,625	6,198
Total assets	90,639								84,003								90,639	84,003
Corporate
Segment Reporting Information [Line Items]
Net interest income																	(17,424)	(18,061)	(17,636)
Noninterest income																	632	177	242
Noninterest expense																	2,966	972	395
Income tax expense (benefit)																	(9,771)	(8,469)	(6,901)
Net income																	(9,987)	(10,387)	$ (10,888)
Total assets	$ 4,081								$ 7,381								$ 4,081	$ 7,381
[1]	Includes net securities gains (losses) of $16 thousand, $1 thousand, $(244) thousand and $81 thousand during the fourth, third, second and first quarters of 2017, respectively.
[2]	Includes net securities gains of $1.3 million, $1.4 million, $1.0 million and $64 thousand during the fourth, third, second and first quarters of 2016, respectively

Equity-based Compensation - Add

Equity-based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 21, 2015	Nov. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock granted	258,375	395,250	0	395,250
Restricted stock cancelled		258,375
Stock units granted, new grantees		277,500		277,500	258,375
Equity-based compensation expense			$ 1,700	$ 117	$ 631
Remaining expense related to unvested restricted stock units			$ 1,800
Expense recognition period			14 months
Number of shares outstanding, non-vested			672,750	672,750	258,375
Fair value per unit at grant date, non-vested			$ 5.14	$ 5.14	$ 13.43
Stock units forfeited			0
Restricted Stock Units | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights, percentage			0.00%
Vested in period, weighted average grant date fair value			$ 21.76
Restricted Stock Units | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights, percentage			1.75%
Vested in period, weighted average grant date fair value			$ 27.55
Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares available for grant			7,500,000
Shares of common stock remain available for future grants			6,827,250

Equity-based compensation - Sch

Equity-based compensation - Schedule of Fair Value Restricted Stock Units (Details) - Restricted Stock Units	12 Months Ended
	Dec. 31, 2017$ / shares
Fair value of common stock (non-marketable, per share)	$ 14.83
Time to settlement date	2 years 29 days
Volatility	30.00%
Risk-free rate	1.10%

Equity-based compensation - Sum

Equity-based compensation - Summary of activity related to restricted stock unit awards (Details) - Restricted Stock Units - $ / shares	Jul. 21, 2015	Nov. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Number of shares, Non-vested at beginning of period			672,750	258,375
Number of shares, Units deemed improbable to vest				(258,375)
Number of shares, Amended grants	258,375	395,250	0	395,250
Number of shares, New units		277,500		277,500	258,375
Number of shares, Non-vested at end of period			672,750	672,750	258,375
Fair value per unit at award date, Non-vested at beginning of period			$ 5.14	$ 13.43
Fair value per unit at award date, Units deemed improbable to vest				13.43
Fair value per unit at award date, Amended grants				5.14
Fair value per unit at award date, New units				5.14	$ 13.43
Fair value per unit at award date, Non-vested at end of period			$ 5.14	$ 5.14	$ 13.43

Condensed Financial Informat125

Condensed Financial Information of Cadence Bancorporation (Parent Only) - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Cash and due from banks	$ 238,707	$ 48,017
Interest-bearing deposits with banks	482,568	199,747
Other assets	91,866	84,806
Total Assets	10,948,926	9,530,888
Liabilities:
Senior debt	184,629	193,788
Subordinated debt	98,687	98,441
Junior subordinated debentures	36,472	35,989
Other liabilities	107,541	101,929
Total liabilities	9,589,870	8,450,390
Shareholder’s Equity:
Common Stock	836	750
Additional paid-in capital	1,037,040	879,665
Retained earnings	340,213	232,614
Accumulated other comprehensive loss ("OCI")	(19,033)	(32,531)
Total shareholders' equity	1,359,056	1,080,498	$ 1,054,208	$ 1,014,337
Total Liabilities and Shareholders' Equity	10,948,926	9,530,888
Cadence Bancorporation
ASSETS
Cash and due from banks	494
Interest-bearing deposits with banks	150,587	50,330
Investment in consolidated bank subsidiary	1,488,223	1,315,336
Investment in consolidated nonbank subsidiaries	16,008	14,881
Other assets	3,587	7,381
Total Assets	1,658,899	1,387,928
Liabilities:
Interest payable	813	810
Senior debt	184,629	193,788
Subordinated debt	73,982	73,788
Junior subordinated debentures	36,472	35,989
Other liabilities	3,947	3,055
Total liabilities	299,843	307,430
Shareholder’s Equity:
Common Stock	836	750
Additional paid-in capital	1,037,040	879,665
Retained earnings	340,213	232,614
Accumulated other comprehensive loss ("OCI")	(19,033)	(32,531)
Total shareholders' equity	1,359,056	1,080,498
Total Liabilities and Shareholders' Equity	$ 1,658,899	$ 1,387,928

Condensed Financial Informat126

Condensed Financial Information of Cadence Bancorporation (Parent Only) - Condensed Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
INCOME
Interest income	$ 108,370	$ 99,503	$ 99,375	$ 89,619	$ 87,068	$ 84,654	$ 82,921	$ 80,607	$ 396,867	$ 335,250	$ 293,067
Other income									24,656	17,678	15,017
EXPENSES
Interest expense	20,459	18,340	16,991	14,861	14,570	14,228	13,672	13,341	70,651	55,811	45,289
Other expense									60,665	60,598	65,856
Income before income taxes	51,671	50,034	42,538	38,756	44,687	8,714	22,015	22,898	182,999	98,314	59,365
Income tax expense (benefit)	36,980	17,457	13,570	12,639	15,701	2,107	7,175	7,557	80,646	32,540	20,109
Net income	$ 14,691	$ 32,577	$ 28,968	$ 26,117	$ 28,986	$ 6,607	$ 14,840	$ 15,341	102,353	65,774	39,256
Cadence Bancorporation
INCOME
Dividends from bank subsidiary									11,000	13,500	8,500
Dividends from nonbank subsidiary											500
Interest income									65	25	21
Other income									632	176	22
Total income									11,697	13,701	9,043
EXPENSES
Interest expense									17,424	18,060	17,635
Other expense									3,305	2,092	271
Total expenses									20,729	20,152	17,906
Loss before income taxes and equity in undistributed income of subsidiaries									(9,032)	(6,451)	(8,863)
Equity in undistributed income of subsidiaries									103,390	64,424	41,132
Income before income taxes									94,358	57,973	32,269
Income tax expense (benefit)									(7,995)	(7,801)	(6,987)
Net income									$ 102,353	$ 65,774	$ 39,256

Condensed Financial Informat127

Condensed Financial Information of Cadence Bancorporation (Parent Only) - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 14,691	$ 32,577	$ 28,968	$ 26,117	$ 28,986	$ 6,607	$ 14,840	$ 15,341	$ 102,353	$ 65,774	$ 39,256
Adjustments to reconcile net income to net cash provided (used) in operations:
Deferred income taxes									44,388	5,980	(2,928)
Decrease in other assets									4,079	(11,685)	1,785
Increase (decrease) in interest payable									1,361	725	1,086
Increase (decrease) in other liabilities									16,717	286	3,736
Net cash provided by operating activities									144,698	118,013	110,207
CASH FLOWS FROM INVESTING ACTIVITIES
Net cash used in investing activities									(951,103)	(993,358)	(1,188,225)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of subordinated debt, net of debt issuance costs											39,253
Issuance of senior debt, net of debt issuance costs											9,813
Purchase of senior debt									(9,600)	(78)
Proceeds from issuance of common stock									155,581
Net cash provided by financing activities									1,288,291	657,063	1,074,809
Net increase (decrease) in cash and cash equivalents									481,886	(218,282)	(3,209)
Cash and cash equivalents at beginning of period				248,925				467,207	248,925	467,207	470,416
Cash and cash equivalents at end of period	730,811				248,925				730,811	248,925	467,207
Cadence Bancorporation
CASH FLOWS FROM OPERATING ACTIVITIES
Net income									102,353	65,774	39,256
Adjustments to reconcile net income to net cash provided (used) in operations:
Deferred income taxes									1,084	(1,598)	(531)
Equity in undistributed income of subsidiaries									(103,390)	(64,424)	(41,132)
Decrease in other assets									3,892	3,043	2,539
Increase (decrease) in interest payable									3	(102)	804
Increase (decrease) in other liabilities									891	(504)	(747)
Net cash provided by operating activities									4,833	2,189	189
CASH FLOWS FROM INVESTING ACTIVITIES
Capital contributions to Bank subsidiary									(50,000)		(20,000)
(Increase) decrease in limited partnership investments									(63)	463	(157)
Net cash used in investing activities									(50,063)	463	(20,157)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of subordinated debt, net of debt issuance costs											39,253
Issuance of senior debt, net of debt issuance costs											9,813
Purchase of senior debt									(9,600)	(78)
Proceeds from issuance of common stock									155,581
Net cash provided by financing activities									145,981	(78)	49,066
Net increase (decrease) in cash and cash equivalents									100,751	2,574	29,098
Cash and cash equivalents at beginning of period				$ 50,330				$ 47,756	50,330	47,756	18,658
Cash and cash equivalents at end of period	$ 151,081				$ 50,330				$ 151,081	$ 50,330	$ 47,756

Accumulated Other Comprehens128

Accumulated Other Comprehensive Income (Loss) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	$ 1,080,498	$ 1,054,208	$ 1,014,337
Period change	18,744	(39,571)	(1,025)
Balance	1,359,056	1,080,498	1,054,208
Unrealized Gains (Losses) on Securities Available for Sale
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(21,819)	5,901	8,664
Period change	21,605	(27,720)	(2,763)
Reclassification of amounts within AOCI to retained earnings due to tax reform	(1,946)
Balance	(2,160)	(21,819)	5,901
Unrealized Gains (Losses) on Defined Benefit Pension Plans
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(500)	(487)	(599)
Period change	121	(13)	112
Reclassification of amounts within AOCI to retained earnings due to tax reform	(152)
Balance	(531)	(500)	(487)
Unrealized Gains (Losses) on Derivative Instruments Designated as Cash Flow Hedges
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(10,212)	1,626
Period change	(2,982)	(11,838)	1,626
Reclassification of amounts within AOCI to retained earnings due to tax reform	(3,148)
Balance	(16,342)	(10,212)	1,626
Accumulated OCI
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(32,531)	7,040	8,065
Period change	18,744	(39,571)	(1,025)
Reclassification of amounts within AOCI to retained earnings due to tax reform	(5,246)
Balance	$ (19,033)	$ (32,531)	$ 7,040

Quarterly Results of Operati129

Quarterly Results of Operations (Unaudited) - Summary of Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2016		Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Interest income	$ 108,370		$ 99,503		$ 99,375		$ 89,619		$ 87,068		$ 84,654		$ 82,921		$ 80,607		$ 396,867	$ 335,250	$ 293,067
Interest expense	20,459		18,340		16,991		14,861		14,570		14,228		13,672		13,341		70,651	55,811	45,289
Net interest income	87,911		81,163		82,384		74,758		72,498		70,426		69,249		67,266		326,216	279,439	247,778
Provision for credit losses	(4,475)		1,723		6,701		5,786		(5,222)		29,627		14,471		10,472		9,735	49,348	35,984
Noninterest income	25,656	[1]	27,124	[1]	22,989	[1]	24,105	[1]	22,361	[2]	22,791	[2]	23,105	[2]	20,146	[2]	99,874	88,403	79,903
Noninterest expense	66,371		56,530		56,134		54,321		55,394		54,876		55,868		54,042		233,356	220,180	232,332
Income before income taxes	51,671		50,034		42,538		38,756		44,687		8,714		22,015		22,898		182,999	98,314	59,365
Provision for income taxes	36,980		17,457		13,570		12,639		15,701		2,107		7,175		7,557		80,646	32,540	20,109
Net income	$ 14,691		$ 32,577		$ 28,968		$ 26,117		$ 28,986		$ 6,607		$ 14,840		$ 15,341		$ 102,353	$ 65,774	$ 39,256
Earnings per common share (Basic)	$ 0.18		$ 0.39		$ 0.35		$ 0.35		$ 0.39		$ 0.09		$ 0.20		$ 0.20		$ 1.26	$ 0.88	$ 0.52
Earnings per common share (Diluted)	$ 0.17		$ 0.39		$ 0.35		$ 0.35		$ 0.38		$ 0.09		$ 0.20		$ 0.20		$ 1.25	$ 0.87	$ 0.52
[1]	Includes net securities gains (losses) of $16 thousand, $1 thousand, $(244) thousand and $81 thousand during the fourth, third, second and first quarters of 2017, respectively.
[2]	Includes net securities gains of $1.3 million, $1.4 million, $1.0 million and $64 thousand during the fourth, third, second and first quarters of 2016, respectively

Quarterly Results of Operati130

Quarterly Results of Operations (Unaudited) - Summary of Quarterly Results of Operations (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Securities (losses) gains, net	$ 16	$ 1	$ (244)	$ 81	$ 1,300	$ 1,400	$ 1,000	$ 64,000	$ (146)	$ 3,736	$ 1,171

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($)	Feb. 13, 2018	Feb. 08, 2018	Jan. 24, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Common stock, par value					$ 0.01	$ 0.01
Class A Common Stock | Scenario Plan
Subsequent Event [Line Items]
Cash dividend per share				$ 0.50
Subsequent Event | Class A Common Stock
Subsequent Event [Line Items]
Number of shares sold	0
Proceeds from offering	$ 0
Change in number of shares due to offering	0
Dividend declared date			Jan. 24, 2018
Cash dividend per share			$ 0.125
Dividend paid date			Mar. 20, 2018
Dividend record date			Mar. 1, 2018
Subsequent Event | Class A Common Stock | Secondary Public Offering
Subsequent Event [Line Items]
Issuance of common stock		8,000,000
Common stock, par value		$ 0.01
Subsequent Event | Class A Common Stock | Underwriters
Subsequent Event [Line Items]
Issuance of common stock	1,200,000
Period of option to purchase stock	30 days