LegacyTexas Financial 10-K 8 Feb 18 2017 FY Annual report Financial data

DOCUMENT AND ENTITY INFORMATION

DOCUMENT AND ENTITY INFORMATION - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Feb. 06, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	LegacyTexas Financial Group, Inc.
Entity Central Index Key	1,487,052
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		48,199,611
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 1,785.9

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and due from financial institutions	$ 61,713	$ 59,823
Short-term interest-bearing deposits in other financial institutions	231,743	229,389
Total cash and cash equivalents	293,456	289,212
Securities available for sale, at fair value	419,717	354,515
Securities held to maturity, (fair value: December 31, 2017 — $174,926, December 31, 2016 — $212,981)	173,509	210,387
Loans held for sale, at fair value	16,707	21,279
Loans held for investment:
Loans held for investment (net of allowance for loan losses of $71,301 at December 31, 2017 and $64,576 at December 31, 2016)	6,584,529	5,998,596
Loans held for investment - Warehouse Purchase Program	1,154,588	1,055,341
Total loans held for investment	7,739,117	7,053,937
Federal Home Loan Bank (FHLB) stock and other restricted securities, at cost	64,790	43,266
Bank-owned life insurance	57,684	56,477
Premises and equipment, net	69,693	74,226
Goodwill	178,559	178,559
Other assets	72,964	80,397
Total assets	9,086,196	8,362,255
Deposits
Non-interest-bearing demand	1,635,622	1,383,951
Interest-bearing demand	1,029,375	903,314
Savings and money market	2,735,296	2,710,307
Time	1,367,390	1,367,904
Total deposits	6,767,683	6,365,476
FHLB advances	1,043,163	833,682
Repurchase agreements	84,676	86,691
Subordinated debt	134,522	134,032
Accrued expenses and other liabilities	96,278	57,009
Total liabilities	8,126,322	7,476,890
Commitments and contingent liabilities (See Note 17)
Shareholders’ equity
Preferred stock, $.01 par value; 10,000,000 shares authorized; 0 shares issued — December 31, 2017 and December 31, 2016	0	0
Common stock, $.01 par value; 90,000,000 shares authorized; 48,117,390 shares issued — December 31, 2017 and 47,876,198 shares issued — December 31, 2016	481	479
Additional paid-in capital	603,884	589,408
Retained earnings	370,858	310,641
Accumulated other comprehensive income (loss), net	(3,429)	(2,713)
Unearned Employee Stock Ownership Plan (ESOP) shares; 1,192,093 shares at December 31, 2017 and 1,245,046 shares at December 31, 2016	(11,920)	(12,450)
Total shareholders’ equity	959,874	885,365
Total liabilities and shareholders’ equity	$ 9,086,196	$ 8,362,255

CONSOLIDATED BALANCE SHEETS (PA

CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Fair value of securities held-to-maturity	$ 174,926	$ 212,981
Allowance for loan losses on loans held for investment	$ 71,301	$ 64,576
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	90,000,000	90,000,000
Common stock, shares issued (in shares)	48,117,390	47,876,198
Unearned Employee Stock Ownership Plan (ESOP) shares (in shares)	1,192,093	1,245,046

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest and dividend income
Loans, including fees	$ 347,438	$ 301,542	$ 248,665
Taxable securities	10,800	9,254	9,307
Nontaxable securities	2,907	3,052	2,995
Interest-bearing deposits in other financial institutions	4,009	1,878	631
FHLB and FRB stock and other	1,703	1,626	1,094
Total interest and dividend income	366,857	317,352	262,692
Interest expense
Deposits	36,694	21,034	13,127
FHLB advances	9,650	7,167	6,552
Repurchase agreements and other borrowings	9,082	6,882	1,936
Total interest expense	55,426	35,083	21,615
Net interest income	311,431	282,269	241,077
Provision for credit losses	39,456	26,900	25,465
Net interest income after provision for credit losses	271,975	255,369	215,612
Non-interest income
Service charges and other fees	35,742	36,690	30,936
Net gain on sale of mortgage loans held for sale	7,322	8,225	8,036
Bank-owned life insurance income	1,727	1,744	1,699
Net gain (loss) on securities transactions	(39)	56	203
Gain (loss) on sale and disposition of assets	(1,572)	3,356	873
Other	402	1,860	3,068
Total non-interest income	43,582	51,931	44,815
Non-interest expense
Salaries and employee benefits	95,136	92,568	92,527
Merger and acquisition costs	0	0	1,553
Advertising	4,378	3,861	3,773
Occupancy and equipment	14,385	15,007	14,860
Outside professional services	4,889	3,872	3,332
Regulatory assessments	4,479	4,948	4,260
Data processing	16,796	14,974	11,278
Office operations	9,238	9,901	10,697
Other	11,043	11,246	9,275
Total non-interest expense	160,344	156,377	151,555
Income before income tax expense	155,213	150,923	108,872
Income tax expense	65,719	53,102	37,956
Net income	$ 89,494	$ 97,821	$ 70,916
Earnings per share:
Basic (in dollars per share)	$ 1.91	$ 2.11	$ 1.54
Diluted (in dollars per share)	1.89	2.09	1.53
Dividends declared (in dollars per share)	$ 0.61	$ 0.58	$ 0.54

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 Comprehensive Income [Abstract]
Net income	$ 89,494	$ 97,821	$ 70,916
Change in unrealized gains (losses) on securities available for sale	(1,144)	(3,917)	(1,434)
Reclassification of amount realized through securities transactions	39	(56)	(203)
Tax effect	389	1,393	574
Other comprehensive income (loss), net of tax	(716)	(2,580)	(1,063)
Comprehensive income	$ 88,778	$ 95,241	$ 69,853

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss), Net	Unearned ESOP Shares
Balance at Dec. 31, 2014	$ 568,223	$ 400	$ 386,549	$ 195,327	$ 930	$ (14,983)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	70,916			70,916
Other comprehensive income (loss), net of tax	(1,063)				(1,063)
Dividends declared ($0.54 per share, $0.58 per share and $0.61 per share as of December 31, 2015, 2016 & 2017 respectively)	(25,747)			(25,747)
ESOP shares earned, (184,194 shares, 120,411 shares and 52,953 shares as of December 31 2015, 2016 & 2017 respectively)	5,751		4,284			1,467
Share-based compensation expense	5,477		5,477
Activity in employee stock plans (138,855 shares, 230,372 shares and 241,192 shares as of December 31, 2015, 2016 & 2017 respectively)	1,284	1	1,283
Share repurchase, (357,950 shares)	(7,989)	(4)	(7,985)
Acquisition of LegacyTexas Group, Inc., (7,850,070 shares)	187,224	79	187,145
Balance at Dec. 31, 2015	804,076	476	576,753	240,496	(133)	(13,516)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	97,821			97,821
Other comprehensive income (loss), net of tax	(2,580)				(2,580)
Dividends declared ($0.54 per share, $0.58 per share and $0.61 per share as of December 31, 2015, 2016 & 2017 respectively)	(27,676)			(27,676)
ESOP shares earned, (184,194 shares, 120,411 shares and 52,953 shares as of December 31 2015, 2016 & 2017 respectively)	3,955		2,889			1,066
Share-based compensation expense	6,014		6,014
Activity in employee stock plans (138,855 shares, 230,372 shares and 241,192 shares as of December 31, 2015, 2016 & 2017 respectively)	3,755	3	3,752
Balance at Dec. 31, 2016	885,365	479	589,408	310,641	(2,713)	(12,450)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	89,494			89,494
Other comprehensive income (loss), net of tax	(716)				(716)
Dividends declared ($0.54 per share, $0.58 per share and $0.61 per share as of December 31, 2015, 2016 & 2017 respectively)	(29,277)			(29,277)
ESOP shares earned, (184,194 shares, 120,411 shares and 52,953 shares as of December 31 2015, 2016 & 2017 respectively)	2,834		2,304			530
Share-based compensation expense	7,462		7,462
Activity in employee stock plans (138,855 shares, 230,372 shares and 241,192 shares as of December 31, 2015, 2016 & 2017 respectively)	4,712	2	4,710
Balance at Dec. 31, 2017	$ 959,874	$ 481	$ 603,884	$ 370,858	$ (3,429)	$ (11,920)

CONSOLIDATED STATEMENTS OF CHA7

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (PARENTHETICAL) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Dividends declared (in dollars per share)	$ 0.61	$ 0.58	$ 0.54
ESOP shares earned (in shares)	52,953	120,411	184,194
Activity in employee stock plans (in shares)	241,192	230,372	138,855
Number of shares repurchased (in shares)			357,950
Stock issued for acquisition (in shares)			7,850,070

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	$ 89,494	$ 97,821	$ 70,916
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	39,456	26,900	25,465
Depreciation and amortization	7,142	7,081	7,196
Deferred tax expense (benefit)	(4,115)	(6,798)	(692)
Impact of Tax Cuts and Jobs Act on deferred taxes	13,493	0	0
Premium amortization and accretion of securities, net	4,337	4,359	4,267
Accretion related to acquired loans	(3,097)	(4,613)	(10,241)
Net (gain) loss on securities transactions	39	(56)	(203)
ESOP compensation expense	2,834	3,955	5,751
Share-based compensation expense	7,462	6,014	5,477
Excess tax benefit on vesting of stock awards	1,578	0	0
Net gain on loans held for sale	(7,322)	(8,225)	(8,036)
Loans originated or purchased for sale	(195,161)	(218,288)	(222,195)
Proceeds from sale of loans held for sale	207,055	227,769	225,335
FHLB stock dividends	(548)	(539)	(152)
Bank-owned life insurance income	(1,727)	(1,744)	(1,699)
(Gain) loss on sale and disposition of repossessed assets, premises and equipment	2,099	(3,524)	(293)
Disposition of insurance subsidiary goodwill upon sale of subsidiary operations	0	2,217	0
Net change in deferred loan fees/costs	(8,631)	391	(1,067)
Net change in accrued interest receivable	(4,249)	(3,238)	(2,821)
Net change in other assets	(1,299)	(2,947)	8,444
Net change in other liabilities	40,176	5,913	(16,250)
Net cash provided by operating activities	189,016	132,448	89,202
Available for sale securities:
Maturities, prepayments and calls	2,028,905	2,276,913	2,114,641
Purchases	(2,098,681)	(2,334,558)	(2,148,080)
Proceeds from sale of AFS securities	0	7,700	36,984
Held to maturity securities:
Maturities, prepayments and calls	35,973	41,384	49,730
Purchases	0	(12,477)	(15,933)
Originations of Warehouse Purchase Program loans	(21,917,085)	(19,966,527)	(15,511,029)
Proceeds from pay-offs of Warehouse Purchase Program loans	21,817,838	19,954,905	15,253,726
Net change in loans held for investment, excluding Warehouse Purchase Program	(620,066)	(1,014,500)	(1,030,016)
Redemption (purchase) of FHLB and FRB stock and other	(20,976)	20,348	(14,527)
Cash received in excess of cash paid for acquisition of LegacyTexas Group, Inc.	0	0	128,598
Purchases of premises and equipment	(3,602)	(8,420)	(5,660)
Proceeds from sale of assets	7,814	15,803	10,121
Net cash (used in) investing activities	(769,880)	(1,019,429)	(1,131,445)
Cash flows from financing activities
Net change in deposits	402,207	1,138,765	940,862
Proceeds from FHLB advances	825,000	200,000	1,350,000
Repayments on FHLB advances	(615,519)	(806,222)	(773,003)
Share repurchase	0	0	(7,989)
Proceeds from borrowings	0	76,861	73,407
Repayments of borrowings	(2,015)	(24,929)	(32,953)
Payment of dividends	(29,277)	(27,676)	(25,747)
Activity in employee stock plans	4,712	3,755	1,284
Net cash provided by financing activities	585,108	560,554	1,525,861
Net change in cash and cash equivalents	4,244	(326,427)	483,618
Beginning cash and cash equivalents	289,212	615,639	132,021
Ending cash and cash equivalents	293,456	289,212	615,639
Supplemental cash flow information:
Interest paid	54,808	34,625	20,861
Income taxes paid	57,482	60,854	36,835
Supplemental noncash disclosures:
Transfers from loans to other real estate owned	4,553	10,780	3,287
Common stock issued in consideration of LegacyTexas Group, Inc. acquisition	$ 0	$ 0	$ 187,224

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Nature of Operations and Principles of Consolidation : The consolidated financial statements include LegacyTexas Financial Group, Inc. (the "Company"), whose business at December 31, 2017 primarily consisted of the operations of its wholly-owned subsidiary, LegacyTexas Bank (the "Bank"). In addition, the Company also offers title services through LegacyTexas Title Co., which is a wholly-owned subsidiary of the Bank. Intercompany transactions and balances are eliminated in consolidation. At December 31, 2017 , the Company provided financial services through 44 banking offices in the Dallas/Fort Worth Metroplex and surrounding counties. Its primary deposit products are demand, savings and certificate of deposit accounts, and its primary lending products are commercial real estate, commercial and industrial and consumer lending, including one- to four-family real estate loans. Most loans are secured by specific items of collateral, including business assets, commercial and residential real estate and consumer assets. Commercial loans are expected to be repaid from cash flow from operations of businesses. Use of Estimates : To prepare financial statements in conformity with U.S. generally accepted accounting principles ("US GAAP"), management makes estimates and assumptions based on available information. These estimates and assumptions affect the amounts reported in the financial statements and the disclosures provided, and actual results could differ. The allowance for loan losses, valuation of other real estate owned, other-than-temporary impairment of securities, realization of deferred tax assets, and fair values of financial instruments are subject to change. Cash Flows : Cash and cash equivalents include cash, deposits with other financial institutions with maturities less than 90 days, and federal funds sold. Net cash flows are reported for customer loan and deposit transactions, interest-bearing deposits in other financial institutions, federal funds purchased, Federal Home Loan Bank advances and repurchase agreements. Restrictions on Cash : The Company maintains deposits with other financial institutions in amounts that exceed federal deposit insurance coverage. Management regularly evaluates the credit risk associated with the counterparties to these transactions and believes that the Company is not exposed to any significant credit risks on cash and cash equivalents. Cash balances equaling or exceeding escrow amounts are maintained at correspondent banks. Securities : Securities that the Company has both the positive intent and ability to hold to maturity are classified as held to maturity and are carried at amortized cost. Securities that the Company intends to hold for an indefinite period of time, but not necessarily to maturity, are classified as available for sale and are carried at fair value. Unrealized gains and losses on securities classified as available for sale have been accounted for as accumulated other comprehensive income (loss), net of taxes. Gains and losses on the sale of securities classified as available for sale are recorded on the trade date using the specific-identification method. Amortization of premiums and discounts are recognized in interest income over the period to maturity. Premiums and discounts on securities are amortized using the level-yield method without anticipating prepayment, except for mortgage-backed securities where prepayments are anticipated. The Company evaluates securities for other-than-temporary impairment on at least a quarterly basis and more frequently when economic, market, or security specific concerns warrant such evaluation. Consideration is given to the length of time and the extent to which the fair value has been less than amortized cost, the financial condition and near-term prospects of the issuer, whether the market decline was affected by macroeconomic conditions and whether the Company has the intent and ability to retain its investment in the issuer for a period of time sufficient to allow for any anticipated recovery in fair value. In analyzing an issuer’s financial condition, the Company may consider whether the securities are issued by the federal government or its agencies, whether downgrades by bond rating agencies have occurred, and the results of reviews of the issuers’ financial condition. The Company conducts regular reviews of the bond agency ratings of securities and considers whether the securities were issued by or have principal and interest payments guaranteed by the federal government or its agencies. These reviews focus on the underlying rating of the issuer and also include the insurance rating of securities that have an insurance component or guarantee. The ratings and financial condition of the issuers are monitored, as well as the financial condition and ratings of the insurers and guarantors. For periods in which other-than-temporary impairment of a debt security is recognized, the credit portion of the amount is determined by subtracting the present value of the stream of estimated cash flows as calculated in a discounted cash flow model and discounted at book yield from the prior period’s ending carrying value. The non-credit portion of the amount is determined by subtracting the credit portion of the impairment from the difference between the book value and fair value of the security. The credit related portion of the impairment is charged against income and the non-credit related portion is charged to equity as a component of accumulated other comprehensive income. The Company did not recognize any other-than-temporary impairment on its securities portfolio for the years ended December 31, 2017 and 2016 . Mortgage Loans Held for Sale : The Company elects the fair value option for recording residential mortgage loans held for sale in accordance with Accounting Standards Codification ("ASC") 825, "Financial Instruments." This election allows for a more effective offset of the changes in fair values of the loans and the derivative instruments used to economically hedge them without the burden of complying with the requirements for hedge accounting under ASC 815, “Derivatives and Hedging.” Warehouse Purchase Program Loans : The Warehouse Purchase Program allows unaffiliated mortgage originators to close one- to four-family real estate loans in their own name and manage their cash flow needs until the loans are sold to investors. The mortgage banking company customer closes mortgage loans consistent with underwriting standards established by the Bank and approved investors and, once all pertinent documents are received, the participation interest is delivered by the Bank to the investor selected by the originator and approved by us. Although not bound by any legally binding commitment, when a purchase decision is made, we purchase a 100% participation interest in the mortgage loans originated by our mortgage banking company customers. All Warehouse Purchase Program loans are collectively evaluated for impairment and are purchased under several contractual requirements, providing safeguards to the Company. These safeguards include the requirement that our mortgage company customers have a takeout commitment or similar arrangement for each loan. To date, the Company has not experienced a loss on these loans and no allowance for loan losses has been allocated to them. Loans : Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at the principal balance outstanding, net of unearned interest, purchase premiums and discounts, deferred loan fees and costs, and an allowance for loan losses. Interest income is accrued on the unpaid principal balance. Loan origination fees, net of certain direct origination costs, are deferred and recognized in interest income using the level-yield method without anticipating prepayments. Past due status is based on the contractual terms of the loan. Loans that are past due 30 days are considered delinquent. Interest income on loans is discontinued at the time the loan is 90 days delinquent unless the loan is well-secured and in process of collection. Non-mortgage consumer loans are typically charged off no later than 120 days past due. In all cases, loans are placed on nonaccrual status or charged-off at an earlier date if collection of principal or interest is considered doubtful. Nonaccrual loans include both smaller balance homogeneous loans that are collectively evaluated for impairment and larger individually classified impaired loans. All interest accrued but not received for loans placed on nonaccrual status is reversed against interest income. Subsequent receipts on non-accrual loans are recorded as a reduction of principal, and interest income is recorded only after principal recovery is reasonably assured. Loans are returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured. For loans collateralized by real property and commercial and industrial loans, credit exposure is monitored by internally assigned grades used for classification of loans. A loan is considered “special mention” when management has determined that there is a potential weakness that deserves management's close attention. Loans rated as "special mention" are not adversely classified according to regulatory classifications and do not expose the Company to sufficient risk to warrant adverse classification. A loan is considered “substandard” if it is inadequately protected by the current net worth and paying capacity of the obligor or the collateral pledged, if any. “Substandard” loans include those characterized by the “distinct possibility” that the insured institution will sustain “some loss” if the deficiencies are not corrected, and the loan may or may not meet the criteria for impairment. Loans classified as “doubtful” have all of the weaknesses of those classified as “substandard” with the added characteristic that the weaknesses present makes “collection or liquidation in full,” on the basis of currently existing facts, conditions and values, “highly questionable and improbable.” All other loans that do not fall into the above mentioned categories are considered “pass” loans. Updates to internally assigned grades are made monthly and/or upon significant developments. For other consumer loans (non-real estate), credit exposure is monitored by payment history of the loans. Non-performing other consumer loans are on nonaccrual status and are generally greater than 90 days past due. Acquired Loans : Loans acquired through the completion of a transfer, including loans acquired in a business combination, that have evidence of deterioration of credit quality since origination and for which it is probable, at acquisition, that the Company will be unable to collect all contractually required payments receivable are initially recorded at fair value (as determined by the present value of expected future cash flows) with no valuation allowance. The difference between the undiscounted cash flows expected at acquisition and the investment in the loan, or the “accretable yield,” is recognized as interest income on a level-yield method over the life of the loan. Contractually required payments for interest and principal that exceed the undiscounted cash flows expected at acquisition, or the “nonaccretable difference,” are not recognized on the balance sheet and do not result in any yield adjustments, loss accruals or valuation allowances. Increases in expected cash flows, including prepayments, subsequent to the initial investment are recognized prospectively through adjustment of the yield on the loan over its remaining life. Decreases in expected cash flows are recognized as impairment. Valuation allowances on these impaired loans reflect only losses incurred after the acquisition (meaning the present value of all cash flows expected at acquisition that ultimately are not to be received). Revolving loans, including lines of credit, are excluded from acquired credit impaired loan accounting. For acquired loans not deemed credit-impaired at acquisition, the differences between the initial fair value and the unpaid principal balance are recognized as interest income on a level-yield basis over the lives of the related loans. Subsequent to the acquisition date, methods utilized to estimate the required allowance for loan losses for these loans is similar to originated loans; however, a provision for credit losses will be recorded only to the extent the required allowance exceeds any remaining credit discounts. Concentration of Credit Risk : Most of the Company’s business activity is with customers located within the North Texas region and a large portion of loans are secured by real estate in this area. Therefore, the Company’s exposure to credit risk is significantly affected by changes in the economy of the North Texas area. Allowance for Loan Losses : The allowance for loan losses and related provision expense are susceptible to change if the credit quality of our loan portfolio changes, which is evidenced by many factors, including but not limited to charge-offs and non-performing loan trends. Generally, consumer real estate lending has a lower credit risk profile compared to other consumer lending (such as automobile loans). Commercial real estate and commercial and industrial lending, however, can have higher risk profiles than consumer loans due to these loans being larger in amount and non-homogeneous in structure and term. Changes in economic conditions, the mix and size of the loan portfolio, and individual borrower conditions can dramatically impact our level of allowance for loan losses in relatively short periods of time. The allowance for loan losses is maintained to cover incurred losses that are estimated in accordance with US GAAP. It is our estimate of credit losses inherent in our loan portfolio at each balance sheet date. Our methodology for analyzing the allowance for loan losses consists of general and specific components. For the general component, we stratify the loan portfolio into homogeneous groups of loans that possess similar loss potential characteristics and apply a loss ratio to these groups of loans to estimate the credit losses in the loan portfolio. We use both historical loss ratios and qualitative loss factors assigned to major loan collateral types to establish general component loss allocations, inclusive of estimated loss emergence periods. Qualitative loss factors are based on management's judgment of company, market, industry or business specific data and external economic indicators, which are not yet reflected in the historical loss ratios, and that could impact the Company's specific loan portfolios. The Allowance for Loan Loss Committee sets and adjusts qualitative loss factors by regularly reviewing changes in underlying loan composition and the seasonality of specific portfolios. The Allowance for Loan Loss Committee also considers credit quality and trends relating to delinquency, non-performing and adversely rated loans within the Company's loan portfolio when evaluating qualitative loss factors. Additionally, the Allowance for Loan Loss Committee adjusts qualitative factors to account for the potential impact of external economic factors, including the unemployment rate, vacancy and capitalization rates and other pertinent economic data specific to our primary market area and lending portfolios. For the specific component, the allowance for loan losses includes loans where management has concerns about the borrower's ability to repay and on individually analyzed loans found to be impaired. Management evaluates current information and events regarding a borrower's ability to repay its obligations and considers a loan to be impaired when the ultimate collectability of amounts due, according to the contractual terms of the loan agreement, is in doubt. If an impaired loan is collateral-dependent, the fair value of the collateral, less the estimated cost to sell, is used to determine the amount of impairment. If an impaired loan is not collateral-dependent, estimated discounted cash flows are used to determine the amount of impairment, if any. For impaired loans, the amount of the impairment can be adjusted, based on current data, until such time as the actual basis is established by acquisition of the collateral or until the basis is collected. Impairment losses are reflected in the allowance for loan losses through a charge to the provision for credit losses. Subsequent recoveries are credited to the allowance for loan losses. Cash receipts for accruing loans are applied to principal and interest under the contractual terms of the loan agreement. Cash receipts on impaired loans for which the accrual of interest has been discontinued are applied first to principal. Large groups of smaller-balance homogeneous loans are collectively evaluated for impairment. As a result, the Company does not separately identify consumer real estate loans less than $417 or individual consumer non-real estate secured loans for impairment disclosures. The Company considers these loans to be homogeneous in nature due to the smaller dollar amount and the similar underwriting criteria. A loan that has been modified is considered a troubled debt restructuring (“TDR”) when two conditions are met: 1) the borrower is experiencing financial difficulty and 2) concessions are made for the borrower's benefit that would not otherwise be considered for a borrower or transaction with similar credit risk characteristics. Modifications to loan terms may include a modification of the contractual interest rate to a below-market rate (even if the modified rate is higher than the original rate), forgiveness of accrued interest, forgiveness of a portion of principal, an extended repayment period or a deed in lieu of foreclosure or other transfer of assets other than cash to fully or partially satisfy a debt. The Company's policy is to place all TDRs on nonaccrual for a minimum period of six months . Loans qualify for return to accrual status once they have demonstrated performance with the restructured terms of the loan agreement for a minimum of six months and the collection of principal and interest under the revised terms is deemed probable. All TDRs are considered to be impaired loans. FHLB stock and other restricted securities: FHLB, FRB and other restricted stock is carried at cost, classified as restricted securities and periodically evaluated for impairment based on the ultimate recoverability of the par value. Both cash and stock dividends are reported as interest income. Bank-Owned Life Insurance : The Company has purchased life insurance policies on certain key employees. The purchase of these life insurance policies allows the Company to use tax-advantaged rates of return. Bank-owned life insurance is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value adjusted for other charges or other amounts due that are probable at settlement. Premises and Equipment : Land is carried at cost. Premises and equipment are stated at cost less accumulated depreciation. Buildings and related components are generally depreciated using the straight-line method with useful lives ranging from 10 to 30 years. Furniture, fixtures and equipment are generally depreciated using the straight-line method with useful lives ranging from 3 to 7 years. The cost of leasehold improvements is amortized over the shorter of the lease term or useful life using the straight-line method. Goodwill : Goodwill represents the excess of the cost of businesses acquired over the fair value of the net assets acquired. According to ASC 350-20, "Intangibles- Goodwill and Other," goodwill shall be tested for impairment between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value below its carrying amount. Deterioration in economic market conditions, changes in key personnel, increased estimates of the effects of recent regulatory or legislative changes, or additional regulatory or legislative changes may result in declines in projected business performance beyond management's current expectations. Such declines in business performance could cause the estimated fair value of goodwill to decline, which could result in an impairment charge to earnings in a future period related to goodwill. The Company evaluates goodwill for impairment on an annual basis or on an interim basis if an event occurs or circumstances change that would more likely than not reduce the fair value below its carrying amount, in accordance with ASC 350-20. During 2016, the Company changed its annual goodwill impairment testing date from December 31 to October 1. The Company believes that this new date is preferable as it provides additional time prior to the Company’s year-end to complete the annual goodwill impairment test, especially in the event of future acquisitions and growth. This change does not accelerate, delay, avoid or cause an impairment charge, nor does this change result in adjustments to previously issued financial statements. The Company first assesses 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 as a basis for determining the need to perform the two-step test for goodwill impairment (the qualitative method). If the qualitative method cannot be used or if it determines, based on the qualified method, that the fair value is more likely than not less than the carrying amount, the Company uses the two-step test. Under the two-step test, the Company compares the estimated fair value of a reporting unit with its carrying amount, including goodwill. If the estimated fair value of a reporting unit exceeds its carrying amount, goodwill of the reporting unit is considered not impaired. If the carrying amount of a reporting unit exceeds its estimated fair value, the second step of the goodwill impairment test is performed to measure the amount of impairment loss, if any. Step two of the goodwill impairment test compares the implied estimated fair value of reporting unit goodwill with the carrying amount of that goodwill. If the carrying amount of goodwill for that reporting unit exceeds the implied fair value of that unit's goodwill, an impairment loss is recognized in an amount equal to that excess. Additional information regarding goodwill and impairment testing can be found in Note 9 - Goodwill and Core Deposit Intangibles. Identifiable Intangibles : Intangible assets are acquired assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights or because the asset is capable of being sold or exchanged either on its own or in combination with a related contract, asset, or liability. The Company's intangible assets relate to core deposits and customer relationships. Intangible assets with definite useful lives are amortized on an accelerated basis over their estimated life. Intangible assets, premises and equipment and other long-lived assets are tested for impairment whenever events or changes in circumstances indicate the carrying amount of the assets may not be recoverable from future undiscounted cash flows. If impaired, the assets are recorded at fair value. Foreclosed Assets : Assets acquired through loan foreclosure are initially recorded at the lower of the recorded investment in the loan at the time of foreclosure or the fair value less costs to sell, establishing a new cost basis. Any write-down in the carrying value of a property at the time of acquisition is charged-off to the allowance for loan losses. If fair value declines subsequent to foreclosure, a valuation allowance is recorded through expense. Operating costs after acquisition are expensed. Derivative Financial Instruments : The Company enters into the following derivative financial instruments: interest rate lock commitments, forward mortgage-backed securities trades and interest rate swaps and caps. These financial instruments are not designated as hedging instruments and are used for asset and liability management and commercial customers' financing needs. All derivatives are carried at fair value in either other assets or other liabilities. For additional information on derivative financial instruments, see Note 7 — Derivative Financial Instruments . Fair Value of Financial Instruments : In general, fair values of financial instruments are based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon internally developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments may include amounts to reflect counterparty credit quality and the Company’s creditworthiness, among other things, as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. Fair value measurements and disclosures guidance establishes a three-level fair value hierarchy based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. For additional information on fair value measurements see Note 6 - Fair Value . Repurchase/Resell Agreements: The Company sells certain securities under agreements to repurchase. The securities sold under these agreements are treated as collateralized borrowings and are recorded at amounts equal to the cash received. The contractual terms of the agreements to repurchase may require the Company to provide additional collateral if the fair value of the securities underlying the borrowings declines during the term of the agreement. Advertising Expense : The Company expenses all advertising costs as they are incurred. Advertising expenses were $4,378 , $3,861 , and $3,773 in 2017 , 2016 and 2015 , respectively. Share-Based Compensation : The Company has shareholder approved share-based compensation plans that are accounted for under ASC 718, Compensation - Stock Compensation , which requires companies to record compensation cost for share-based payment transactions with employees in return for employment service. Compensation cost is recognized for stock options and restricted stock awards based on the fair value of these awards at the date of grant. A Black-Scholes model is utilized to estimate the fair value of stock options, while the market price of the Company’s common stock at the date of grant is used for restricted stock awards. Compensation cost is recognized over the required service period, generally defined as the vesting period. For awards with time-based vesting, compensation cost is recognized on a straight-line basis over the requisite service period for the entire award. For awards with performance-based vesting conditions, compensation cost is recognized when the achievement of the performance condition is considered probable of achievement. If a performance condition is subsequently determined to be improbable of achievement, compensation cost is reversed. Retirement Plans: Employee 401(k) and profit sharing plan expense is the amount of matching contributions as determined by formula. Deferred compensation and supplemental retirement plan expense allocates the benefits over years of service. Income Taxes : Income tax expense is the total of the current year income tax due or refundable and the change in deferred tax assets and liabilities. Deferred tax assets and liabilities are the expected future tax amounts for the temporary differences between carrying amounts and tax bases of assets and liabilities, computed using enacted tax rates. A valuation allowance, if needed, reduces deferred tax assets to the amount expected to be realized. A tax position is recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded. The Company did not have any material uncertain tax positions which would require accrual at December 31, 2017 or 2016 . The Company recognizes interest and/or penalties related to income tax matters in income tax expense and did not have any amounts accrued for interest and penalties for the years ended December 31, 2017 or 2016 . The Company files a consolidated income tax return with its subsidiaries. Federal income tax expense or benefit has been allocated to subsidiaries on a separate return basis. Earnings per common share : The Company calculated earnings per common share in accordance with ASC 260, “Earnings Per Share,” which provides that unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are participating securities and shall be included in the computation of earnings per share pursuant to the two-class method. The Company has determined that its outstanding non-vested stock awards are participating securities. Accordingly, earnings per common share is computed using the two-class method prescribed under ASC 260. Under the two-class method, basic earnings per common share is computed by dividing net earnings allocated to common stock by the weighted-average number of common shares outstanding during the applicable period, excluding outstanding participating securities. Diluted earnings per common share is computed using the weighted-average number of shares determined for the basic earnings per common share computation plus the dilutive effect of stock compensation using the treasury stock method. A reconciliation of the weighted-average shares used in calculating basic earnings per common share and the weighted average common shares used in calculating diluted earnings per common share for the reported periods is provided in Note 3 — Earnings Per Common Share. Comprehensive Income (Loss) : Comprehensive income (loss) consists of net income and other comprehensive income (loss). Other comprehensive income (loss) includes unrealized gains and losses on securities available for sale, net of taxes, which are also recognized as a separate component of equity. Employee stock ownership plan (ESOP) : The Company accounts for its ESOP in accordance with ASC 718-40, "Employee Stock Ownership Plans." Accordingly, since the Company sponsors the ESOP with an employer loan, neither the ESOP’s loan payable nor the Company’s loan receivable are reported in the Company’s consolidated balance sheet. Likewise, the Company does not recognize interest income or interest cost on the loan. Unallocated shares held by the ESOP are recorded as unearned ESOP shares in the consolidated statement of changes in shareholders’ equity. As shares are committed to be released for allocation, the Company recognizes compensation expense equal to the average market price of the shares for the period. Dividends on allocated ESOP shares reduce retained earnings; dividends on unearned ESOP shares reduce principal and accrued interest payable on the ESOP loan. Dividend Restriction : Banking regulations require maintaining certain capital levels and may limit the dividends paid by the Bank to the Company or by the Company to shareholders. Loss Contingencies : Loss contingencies, including claims and legal actions arising in the ordinary course of business, are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated. Management does not believe there now are such matters that will have a material effect on the financial statements. Transfers of Financial Assets : Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (i) the assets have been isolated from the Company, (ii) the transferee has the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (iii) the Company does not maintain effective control over the transferred assets through either (a) an agreement that entitles and obliga

Share Transactions

Share Transactions	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
Share Transactions	Share Transactions In August 2012, the Company's Board of Directors announced its intention to repurchase up to 5% of its total common shares outstanding, or approximately 1,978,871 shares. No shares of Company stock were repurchased under this program in 2017 or in 2016. During 2015, 357,950 shares were repurchased and retired at an average price of $22.32 . At December 31, 2017 , 1,537,121 shares remain available for future repurchases under the program.

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share Basic earnings per common share is computed by dividing net income (which has been adjusted for distributed and undistributed earnings to participating securities) by the weighted-average number of common shares outstanding for the period, reduced for average unallocated ESOP shares and average unvested restricted stock awards. Unvested restricted stock awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are participating securities and shall be included in the computation of earnings per share pursuant to the two-class method described in ASC 260-10-45-60B. Diluted earnings per common share reflects the potential dilution that could occur if securities or other contracts to issue common stock (such as stock awards and options) were exercised or converted to common stock, or resulted in the issuance of common stock that then shared in the Company’s earnings. Diluted earnings per common share is computed by dividing net income by the weighted-average number of common shares outstanding for the period increased for the dilutive effect of unexercised stock options and unvested restricted stock awards. The dilutive effect of the unexercised stock options and unvested restricted stock awards is calculated under the treasury stock method utilizing the average market value of the Company’s stock for the period. A reconciliation of the numerator and denominator of the basic and diluted earnings per common share computation for the years ended December 31, 2017 , 2016 and 2015 is as follows: Years Ended December 31, 2017 2016 2015 Basic earnings per share: Numerator: Net income $ 89,494 $ 97,821 $ 70,916 Distributed and undistributed earnings to participating securities (318 ) (497 ) (534 ) Income available to common shareholders $ 89,176 $ 97,324 $ 70,382 Denominator: Weighted average common shares outstanding 47,998,439 47,721,179 47,659,389 Less: Average unallocated ESOP shares (1,220,516 ) (1,301,356 ) (1,464,324 ) Average unvested restricted stock awards (166,143 ) (235,749 ) (347,781 ) Average shares for basic earnings per share 46,611,780 46,184,074 45,847,284 Basic earnings per common share $ 1.91 $ 2.11 $ 1.54 Diluted earnings per share: Numerator: Income available to common shareholders $ 89,176 $ 97,324 $ 70,382 Denominator: Average shares for basic earnings per share 46,611,780 46,184,074 45,847,284 Dilutive effect of share-based compensation plan 526,738 300,893 278,163 Average shares for diluted earnings per share 47,138,518 46,484,967 46,125,447 Diluted earnings per common share $ 1.89 $ 2.09 $ 1.53 Share awards excluded in the computation of diluted earnings per share because the exercise price was greater than the common stock average market price and were therefore anti-dilutive 623,666 1,384,784 1,012,771

Securities

Securities	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Securities	Securities The amortized cost, related gross unrealized gains and losses recognized in accumulated other comprehensive income (loss), and the fair value of securities available for sale ("AFS") were as follows: December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Agency residential mortgage-backed securities 1 $ 191,216 $ 419 $ 2,169 $ 189,466 Agency commercial mortgage-backed securities 1 9,360 — 125 9,235 Agency residential collateralized mortgage obligations 1 187,637 4 3,425 184,216 US government and agency securities 1,590 81 — 1,671 Municipal bonds 35,196 241 308 35,129 Total securities $ 424,999 $ 745 $ 6,027 $ 419,717 December 31, 2016 Agency residential mortgage-backed securities 1 $ 220,744 $ 635 $ 2,828 $ 218,551 Agency commercial mortgage-backed securities 1 9,422 — 75 9,347 Agency residential collateralized mortgage obligations 1 87,959 22 1,452 86,529 US government and agency securities 2,150 101 — 2,251 Municipal bonds 38,417 47 627 37,837 Total securities $ 358,692 $ 805 $ 4,982 $ 354,515 1 Mortgage-backed securities and collateralized mortgage obligations are issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises. The amortized cost (carrying amount), unrealized gains and losses, and fair value of securities held to maturity ("HTM") were as follows: December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Agency residential mortgage-backed securities 1 $ 57,334 $ 616 $ 646 $ 57,304 Agency commercial mortgage-backed securities 1 27,435 589 98 27,926 Agency residential collateralized mortgage obligations 1 27,112 265 99 27,278 Municipal bonds 61,628 1,079 289 62,418 Total securities $ 173,509 $ 2,549 $ 1,132 $ 174,926 December 31, 2016 Agency residential mortgage-backed securities 1 $ 74,881 $ 1,147 $ 817 $ 75,211 Agency commercial mortgage-backed securities 1 28,023 836 166 28,693 Agency residential collateralized mortgage obligations 1 40,707 697 33 41,371 Municipal bonds 66,776 1,635 705 67,706 Total securities $ 210,387 $ 4,315 $ 1,721 $ 212,981 1 Mortgage-backed securities and collateralized mortgage obligations are issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises. The amortized cost (carrying amount) and fair value of held to maturity debt securities and the fair value of available for sale debt securities at December 31, 2017 by contractual maturity are set forth below in the table below. Securities with contractual payments not due at a single maturity date, including mortgage backed securities and collateralized mortgage obligations, are shown separately. HTM AFS Amortized Cost Fair Value Fair Value Due in one year or less $ 1,365 $ 1,373 $ 1,526 Due after one to five years 10,699 10,959 12,726 Due after five to ten years 44,059 44,628 16,731 Due after ten years 5,505 5,458 5,817 Agency residential mortgage-backed securities 57,334 57,304 189,466 Agency commercial mortgage-backed securities 27,435 27,926 9,235 Agency residential collateralized mortgage obligations 27,112 27,278 184,216 Total $ 173,509 $ 174,926 $ 419,717 Securities with a carrying value of $256,451 and $224,674 at December 31, 2017 and 2016 , respectively, were pledged to secure public deposits, repurchase agreements and for other purposes required or permitted by law. At December 31, 2017 and 2016 , there were no holdings of securities of any one issuer, other than the U.S. Government and its agencies or U.S. Government Sponsored Enterprises, in an amount greater than 10% of shareholders’ equity. Sales activity of securities for the years ended December 31, 2017 , 2016 and 2015 was as follows. All securities sold were classified as available for sale. December 31, 2017 2016 2015 Proceeds $ — $ 7,700 $ 36,984 Gross gains — 72 278 Gross losses — 7 50 Tax expense of securities gains/losses reclassified from accumulated other comprehensive income — 23 80 Securities with unrealized losses at December 31, 2017 and 2016 , aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, were as follows: AFS Less than 12 Months 12 Months or More Total December 31, 2017 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Agency residential mortgage-backed securities 1 $ 59,545 $ 412 $ 100,214 $ 1,757 $ 159,759 $ 2,169 Agency commercial mortgage-backed securities 1 9,235 125 — — 9,235 125 Agency residential collateralized mortgage obligations 1 128,869 1,860 49,171 1,565 178,040 3,425 Municipal bonds 10,114 72 6,583 236 16,697 308 Total temporarily impaired $ 207,763 $ 2,469 $ 155,968 $ 3,558 $ 363,731 $ 6,027 December 31, 2016 Agency residential mortgage-backed securities 1 $ 167,503 $ 2,770 $ 7,516 $ 58 $ 175,019 $ 2,828 Agency commercial mortgage-backed securities 1 9,347 75 — — 9,347 75 Agency residential collateralized mortgage obligations 1 72,822 1,420 2,649 32 75,471 1,452 Municipal bonds 26,911 512 3,412 115 30,323 627 Total temporarily impaired $ 276,583 $ 4,777 $ 13,577 $ 205 $ 290,160 $ 4,982 HTM Less than 12 Months 12 Months or More Total December 31, 2017 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Agency residential mortgage-backed securities 1 $ 20,397 $ 206 $ 16,909 $ 440 $ 37,306 $ 646 Agency commercial mortgage-backed securities 1 3,685 26 3,484 72 7,169 98 Agency residential collateralized mortgage obligations 1 8,008 64 2,267 35 10,275 99 Municipal bonds 9,313 80 10,486 209 19,799 289 Total temporarily impaired $ 41,403 $ 376 $ 33,146 $ 756 $ 74,549 $ 1,132 December 31, 2016 Agency residential mortgage-backed securities 1 $ 41,375 $ 817 $ — $ — $ 41,375 $ 817 Agency commercial mortgage-backed securities 1 7,273 166 — — 7,273 166 Agency residential collateralized mortgage obligations 1 6,322 11 1,451 22 7,773 33 Municipal bonds 19,362 658 1,045 47 20,407 705 Total temporarily impaired $ 74,332 $ 1,652 $ 2,496 $ 69 $ 76,828 $ 1,721 1 Mortgage-backed securities and collateralized mortgage obligations are issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises. As of December 31, 2017 , 259 securities had unrealized losses, 122 of which had been in an unrealized loss position for over 12 months at December 31, 2017 . The Company does not believe these unrealized losses are other-than-temporary and expects full collection of the carrying amount of these securities. At December 31, 2017 , the Company does not intend to sell the securities in an unrealized loss position, and it is not more-likely-than-not that the Company will be required to sell the securities prior to recovery of amortized cost. All principal and interest payments are being received on time and in full.

Loans

Loans	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Loans	Loans Loans consist of the following: December 31, 2017 December 31, 2016 Loans held for sale, at fair value $ 16,707 $ 21,279 Loans held for investment: Commercial real estate $ 3,019,339 $ 2,670,455 Commercial and industrial 2,093,307 1,971,160 Construction and land 277,864 294,894 Consumer real estate 1,213,434 1,074,923 Other consumer 45,506 53,991 Gross loans held for investment, excluding Warehouse Purchase Program 6,649,450 6,065,423 Net of: Deferred costs (fees) and discounts, net 6,380 (2,251 ) Allowance for loan losses (71,301 ) (64,576 ) Net loans held for investment, excluding Warehouse Purchase Program 6,584,529 5,998,596 Warehouse Purchase Program 1,154,588 1,055,341 Total loans held for investment $ 7,739,117 $ 7,053,937 Activity in the allowance for loan losses for the years ended December 31, 2017 , 2016 and 2015 , segregated by portfolio segment and evaluation for impairment, is set forth below. The below activity does not include Warehouse Purchase Program loans, which are collectively evaluated for impairment and are purchased under several contractual requirements, providing safeguards to the Company. To date, the Company has not experienced a loss on its Warehouse Purchase Program loans and no allowance for loan losses has been allocated to them. At December 31, 2017 , 2016 and 2015 , the allowance for loan impairment related to purchased credit impaired ("PCI") loans totaled $269 , $180 , and $150 , respectively. For the year ended December 31, 2017 Commercial Real Estate Commercial and Industrial Construction and Land Consumer Real Estate Other Consumer Total Allowance for loan losses: Beginning balance $ 18,303 $ 35,464 $ 5,075 $ 4,484 $ 1,250 $ 64,576 Charge-offs (16 ) (32,846 ) (418 ) (96 ) (1,366 ) (34,742 ) Recoveries 205 405 75 42 640 1,367 Provision expense (benefit) 3,095 35,982 (88 ) 408 703 40,100 Ending balance $ 21,587 $ 39,005 $ 4,644 $ 4,838 $ 1,227 $ 71,301 Allowance ending balance: Individually evaluated for impairment $ — $ 10,527 $ — $ 230 $ 34 $ 10,791 Collectively evaluated for impairment 21,587 28,478 4,644 4,608 1,193 60,510 Loans: Individually evaluated for impairment 4,134 84,005 — 2,992 35 91,166 Collectively evaluated for impairment 3,012,892 2,009,126 277,864 1,209,550 45,288 6,554,720 PCI loans 2,313 176 — 892 183 3,564 Ending balance $ 3,019,339 $ 2,093,307 $ 277,864 $ 1,213,434 $ 45,506 $ 6,649,450 For the year ended December 31, 2016 Commercial Real Estate Commercial and Industrial Construction and Land Consumer Real Estate Other Consumer Total Allowance for loan losses: Beginning balance $ 14,123 $ 24,975 $ 3,013 $ 3,992 $ 990 $ 47,093 Charge-offs (79 ) (7,746 ) — (107 ) (927 ) (8,859 ) Recoveries 21 472 — 109 340 942 Provision expense 4,238 17,763 2,062 490 847 25,400 Ending balance $ 18,303 $ 35,464 $ 5,075 $ 4,484 $ 1,250 $ 64,576 Allowance ending balance: Individually evaluated for impairment $ 300 $ 4,521 $ — $ 138 $ 52 $ 5,011 Collectively evaluated for impairment 18,003 30,943 5,075 4,346 1,198 59,565 Loans: Individually evaluated for impairment 5,195 86,664 11,385 3,300 75 106,619 Collectively evaluated for impairment 2,659,644 1,884,263 283,509 1,070,732 53,683 5,951,831 PCI loans 5,616 233 — 891 233 6,973 Ending balance $ 2,670,455 $ 1,971,160 $ 294,894 $ 1,074,923 $ 53,991 $ 6,065,423 For the year ended December 31, 2015 Commercial Real Estate Commercial and Industrial Construction and Land Consumer Real Estate Other Consumer Total Allowance for loan losses: Beginning balance $ 11,830 $ 9,068 $ 174 $ 4,069 $ 408 $ 25,549 Charge-offs (167 ) (3,129 ) — (321 ) (1,090 ) (4,707 ) Recoveries 29 246 — 85 426 786 Provision expense 2,431 18,790 2,839 159 1,246 25,465 Ending balance $ 14,123 $ 24,975 $ 3,013 $ 3,992 $ 990 $ 47,093 Allowance ending balance: Individually evaluated for impairment $ 366 $ 1,470 $ — $ 81 $ 61 $ 1,978 Collectively evaluated for impairment 13,757 23,505 3,013 3,911 929 45,115 Loans: Individually evaluated for impairment 11,580 16,906 33 4,767 120 33,406 Collectively evaluated for impairment 2,155,351 1,595,548 269,675 931,140 69,433 5,021,147 PCI loans 10,612 215 — 850 277 11,954 Ending balance $ 2,177,543 $ 1,612,669 $ 269,708 $ 936,757 $ 69,830 $ 5,066,507 Changes in the allowance for off-balance sheet credit losses on lending-related commitments and guarantees on credit card debt, included in "accrued expenses and other liabilities" on the consolidated balance sheets, are summarized in the following table. Please see Note 17 - Commitments and Contingent Liabilities for more information. Years Ended December 31, 2017 2016 Balance at beginning of period $ 1,573 $ 73 Charge-offs on lending-related commitments — — Provision (recovery) for credit losses on lending-related commitments (644 ) 1,500 Balance at end of period $ 929 $ 1,573 Impaired loans at December 31, 2017 and 2016 , were as follows 1 : December 31, 2017 Unpaid Contractual Principal Balance Recorded Investment With No Allowance Recorded Investment With Allowance Total Recorded Investment Related Allowance Commercial real estate $ 4,411 $ 4,134 $ — $ 4,134 $ — Commercial and industrial 89,713 48,463 35,542 84,005 10,502 Consumer real estate 3,545 2,985 7 2,992 7 Other consumer 71 16 19 35 13 Total $ 97,740 $ 55,598 $ 35,568 $ 91,166 $ 10,522 December 31, 2016 Commercial real estate $ 5,388 $ 4,429 $ 766 $ 5,195 $ 272 Commercial and industrial 87,756 73,377 13,287 86,664 4,519 Construction and land 11,384 11,385 — 11,385 — Consumer real estate 3,766 3,290 10 3,300 10 Other consumer 107 33 42 75 30 Total $ 108,401 $ 92,514 $ 14,105 $ 106,619 $ 4,831 1 No Warehouse Purchase Program loans were impaired at December 31, 2017 or 2016 . Loans reported do not include PCI loans. Income on impaired loans at December 31, 2017 , 2016 and 2015 , was as follows 1 December 31, 2017 December 31, 2016 December 31, 2015 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial real estate $ 4,421 $ 8 $ 5,240 $ 9 $ 8,178 $ 24 Commercial and industrial 83,508 — 28,634 1 19,595 8 Construction and land 2,273 — 901 — 84 — Consumer real estate 2,786 14 4,831 14 5,269 7 Other consumer 264 4 95 4 202 2 Total $ 93,252 $ 26 $ 39,701 $ 28 $ 33,328 $ 41 1 Loans reported do not include PCI loans. No loans past due over 90 days were still accruing interest at December 31, 2017 . At December 31, 2016 , loans past due over 90 days still accruing interest totaled $141 , which consisted entirely of PCI loans. At December 31, 2017 , no PCI loans were considered non-performing loans. No Warehouse Purchase Program loans were non-performing at December 31, 2017 or 2016 . Non-performing loans were as follows: December 31, 2017 2016 Commercial real estate $ 4,134 $ 5,195 Commercial and industrial 84,003 86,664 Construction and land — 11,385 Consumer real estate 6,190 7,987 Other consumer 76 158 Total $ 94,403 $ 111,389 For the years ended December 31, 2017 , 2016 and 2015 , gross interest income which would have been recorded had the non-accruing loans been current in accordance with their original terms amounted to $4,229 , $1,746 and $1,594 , respectively. No interest income was recorded on these loans for the years ended December 31, 2017 , 2016 and 2015 . The outstanding balances of TDRs are shown below: December 31, 2017 2016 Nonaccrual TDRs (1) $ 17,294 $ 11,701 Performing TDRs (2) 768 454 Total $ 18,062 $ 12,155 Outstanding commitments to lend additional funds to borrowers with TDR loans — — 1 Nonaccrual TDR loans are included in the nonaccrual loan totals. 2 Performing TDR loans are loans that have been performing under the restructured terms for at least six months and the Company is accruing interest on these loans. The following table provides the recorded balances of loans modified as a TDR during the years ended December 31, 2017 , 2016 and 2015 . December 31, 2017 Principal Deferrals Combination of Rate Reduction & Principal Deferral Other Total Commercial and industrial $ 38 $ 131 $ 14,063 (1) $ 14,232 Total $ 38 $ 131 $ 14,063 $ 14,232 December 31, 2016 Commercial and industrial $ 685 $ — $ 7,090 (1) $ 7,775 Consumer real estate — 79 — 79 Other consumer 1 — — 1 Total $ 686 $ 79 $ 7,090 $ 7,855 December 31, 2015 Commercial real estate $ 100 $ — $ — $ 100 Commercial and industrial — — 191 191 Consumer real estate 209 (2) 60 36 305 Other consumer 1 — 3 4 Total $ 310 $ 60 $ 230 $ 600 1 Reserve-based energy relationships where the primary modification consisted of suspension of required borrowing base payments. 2 Principal deferrals include Chapter 7 bankruptcy loans for which the court has discharged the borrower's obligation and the borrower has not reaffirmed the debt. Such loans are placed on non-accrual status. Loans modified as a TDR during the years ended December 31, 2017 , 2016 and 2015 , which experienced a subsequent payment default during the periods, are shown below. A payment default is defined as a loan that was 90 days or more past due. Years Ended December 31, 2017 2016 2015 Consumer real estate $ — $ 31 $ 178 Loans acquired with evidence of credit quality deterioration at acquisition, for which it was probable that the Company would not be able to collect all contractual amounts due, were accounted for as PCI loans. The carrying amount of PCI loans included in the consolidated balance sheets and the related outstanding balances at December 31, 2017 and 2016 are set forth in the table below. The outstanding balance represents the total amount owed, including accrued but unpaid interest, and any amounts previously charged off. December 31, 2017 2016 Carrying amount 1 $ 3,295 $ 6,793 Outstanding balance 3,992 7,597 1 The carrying amounts are reported net of allowance for loan losses of $269 and $180 as of December 31, 2017 and 2016 . Changes in the accretable yield for PCI loans for the years ended December 31, 2017 and 2016 , are as follows: December 31, 2017 2016 Balance at beginning of period $ 2,515 $ 3,356 Reclassifications from nonaccretable 602 429 Disposals (187 ) (359 ) Accretion (651 ) (911 ) Balance at end of period $ 2,279 $ 2,515 Below is an analysis of the age of recorded investment in loans that were past due at December 31, 2017 and 2016 . No Warehouse Purchase Program loans were delinquent at December 31, 2017 or 2016 and therefore are not included in the following table. December 31, 2017 30-59 Days Past Due 60-89 Days Past Due 90 Days and Greater Past Due Total Loans Past Due Current Loans 1 Total Loans Commercial real estate $ 9,414 $ — $ 250 $ 9,664 $ 3,009,675 $ 3,019,339 Commercial and industrial 918 284 7,350 8,552 2,084,755 2,093,307 Construction and land 9,354 — — 9,354 268,510 277,864 Consumer real estate 16,436 2,928 1,367 20,731 1,192,703 1,213,434 Other consumer 891 34 2 927 44,579 45,506 Total $ 37,013 $ 3,246 $ 8,969 $ 49,228 $ 6,600,222 $ 6,649,450 December 31, 2016 Commercial real estate $ 1,829 $ 72 $ 766 $ 2,667 $ 2,667,788 $ 2,670,455 Commercial and industrial 20,910 495 46 21,451 1,949,709 1,971,160 Construction and land 19,517 283 — 19,800 275,094 294,894 Consumer real estate 10,487 1,916 1,199 13,602 1,061,321 1,074,923 Other consumer 1,523 31 6 1,560 52,431 53,991 Total $ 54,266 $ 2,797 $ 2,017 $ 59,080 $ 6,006,343 $ 6,065,423 1 Includes acquired PCI loans with a total carrying value of $3,338 and $6,729 at December 31, 2017 and 2016 , respectively. The recorded investment in loans by credit quality indicators at December 31, 2017 and 2016 , was as follows. Real Estate and Commercial and Industrial Credit Exposure Credit Risk Profile by Internally Assigned Grade December 31, 2017 Commercial Real Estate Commercial and Industrial Construction and Land Consumer Real Estate Grade: 1 Pass $ 2,980,656 $ 1,953,496 $ 277,864 $ 1,203,236 Special Mention 30,656 43,161 — 1,408 Substandard 8,027 96,546 — 7,762 Doubtful — 104 — 1,028 Total $ 3,019,339 $ 2,093,307 $ 277,864 $ 1,213,434 December 31, 2016 Grade: 1 Pass $ 2,648,842 $ 1,712,171 $ 283,423 $ 1,062,549 Special Mention 7,972 155,110 — 2,083 Substandard 12,875 103,815 11,471 8,252 Doubtful 766 64 — 2,039 Total $ 2,670,455 $ 1,971,160 $ 294,894 $ 1,074,923 1 PCI loans are included in the substandard or doubtful categories for December 31, 2017 and 2016 , respectively. These categories are generally consistent with the "substandard" and "doubtful" categories as defined by regulatory authorities. Warehouse Purchase Program Credit Exposure All Warehouse Purchase Program loans were graded pass as of December 31, 2017 and 2016 . Consumer Other Credit Exposure Credit Risk Profile Based on Payment Activity December 31, 2017 December 31, 2016 Performing $ 45,430 $ 53,833 Non-performing 76 158 Total $ 45,506 $ 53,991

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value	Fair Value ASC 820, “Fair Value Measurements and Disclosures,” establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard describes three levels of inputs that may be used to measure fair value: Level 1: Quoted prices (unadjusted) for identical assets or liabilities in active markets that the entity has the ability to access as of the measurement date. Level 2: Significant other observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data. Level 3: Prices or valuation techniques that require inputs that are both significant and unobservable in the market. These instruments are valued using the best information available, some of which is internally developed, and reflects a reporting entity’s own assumptions about the risk premiums that market participants would generally require and the assumptions they would use. Assets and Liabilities Measured on a Recurring Basis Assets and liabilities measured at fair value on a recurring basis are summarized below. Fair Value Measurements Using Level 2 December 31, 2017 December 31, 2016 Assets: Agency residential mortgage-backed securities $ 189,466 $ 218,551 Agency commercial mortgage-backed securities 9,235 9,347 Agency residential collateralized mortgage obligations 184,216 86,529 US government and agency securities 1,671 2,251 Municipal bonds 35,129 37,837 Total securities available for sale $ 419,717 $ 354,515 Loans held for sale 1 $ 16,707 $ 21,279 Derivative financial instruments: Interest rate lock commitments 358 379 Forward mortgage-backed securities trades 7 36 Loan customer counterparty — — Financial institution counterparty 1,735 1,369 Liabilities: Derivative financial instruments: Interest rate lock commitments — — Forward mortgage-backed securities trades 18 80 Loan customer counterparty 1,735 1,369 Financial institution counterparty — — 1 At December 31, 2017 , loans held for sale had an aggregate outstanding principal balance of $16,242 . There were no mortgage loans held for sale that were 90 days or greater past due or on non-accrual at December 31, 2017 . The following methodologies were used to measure the fair value of financial assets and liabilities valued on a recurring basis: Securities available for sale - The fair values of securities available for sale are determined by matrix pricing, which is a mathematical technique widely used in the industry to value debt securities without relying exclusively on quoted prices for the specific securities but rather by relying on the securities' relationship to other benchmark quoted securities (Level 2 inputs). Residential mortgage loans held for sale - Mortgage loans held for sale, which are sold on a servicing released basis, are valued using a market approach by utilizing either: (i) the fair value of securities backed by similar mortgage loans, adjusted for certain factors to approximate the fair value of a whole mortgage loan, including the value attributable to mortgage servicing and credit risk, (ii) current commitments to purchase loans or (iii) recent observable market trades for similar loans, adjusted to credit risk and other individual loan characteristics. As these prices are derived from market observable inputs, the Company classifies these valuations as Level 2 in the fair value disclosures. Interest income on mortgage loans held for sale is recognized based on the contractual rates and reflected in interest income on loans held for sale in the consolidated income statement. The Company has no continuing involvement in any residential mortgage loans sold. Derivative instruments: Interest rate lock commitments ("IRLCs") - The estimated fair values of IRLCs utilize current secondary market prices for underlying loans and estimated servicing value with similar coupons, maturity and credit quality, subject to the anticipated loan funding probability (Pull-through rate). The fair value of IRLCs is subject to change primarily due to changes in interest rates and the estimated Pull-through rate. These commitments are classified as Level 2 in the fair value disclosures, as the valuations are based on observable market inputs. Forward mortgage-backed securities trades - These forward mortgage-backed securities trades are exchange-traded or traded within highly active dealer markets. In order to determine the fair value of these instruments, the Company utilized the exchange price or dealer market price for the particular derivative contract; therefore these contracts are classified as Level 2. The estimated fair values are subject to change primarily due to changes in interest rates. Loan customer counterparty and financial institution counterparty - The Company also enters into certain interest rate derivative positions that are not designated as hedging instruments. The estimated fair value of these commercial loan interest rate swaps are obtained from a pricing service that provides the swaps' unwind value (Level 2 inputs). Please see Note 6 — Derivative Financial Instruments for more information. Assets and Liabilities Measured on a Non-Recurring Basis Assets measured at fair value on a non-recurring basis are summarized below. There were no liabilities measured at fair value on a non-recurring basis as of December 31, 2017 or 2016 . Fair Value Measurements Using Level 3 December 31, 2017 December 31, 2016 Assets: Impaired loans $ 25,046 $ 9,274 Foreclosed assets: Commercial real estate 6,694 10,638 Construction and land 859 194 Consumer real estate 192 — Other 687 6 Methodologies used to measure the fair value of financial assets and liabilities valued on a non-recurring basis are shown below: Impaired loans - Impaired loans that are collateral dependent are measured for impairment using the fair value of the collateral adjusted by additional Level 3 inputs, such as discounts of market value, estimated marketing costs and estimated legal expenses. Impaired loans secured by real estate, receivables or inventory had discounts determined by management on an individual loan basis. Impaired loans that are not collateral dependent are measured for impairment by a discounted cash flow analysis using a net present value calculation that utilizes data from the loan file before and after the modification. Foreclosed assets - These assets are measured at the lower of book or fair value less costs to sell using third party appraisals, listing agreements or sale contracts, which may be adjusted by additional Level 3 inputs, such as discounts of market value, estimated marketing costs and estimated legal expenses. Management may also consider additional adjustments on specific properties due to the age of the appraisal, expected holding period, lack of comparable sales, or if the other real estate owned is a special use property. At December 31, 2017 , the Company had $400 in residential mortgage loans in the process of foreclosure. The Credit Risk Management department evaluates the valuations on impaired loans and foreclosed assets at least quarterly. The valuations on impaired loans are reviewed at least quarterly by the Allowance for Loan Loss Committee and are considered in the calculation of the allowance for loan losses. Unobservable inputs, such as discounts to collateral, are monitored and adjusted if market conditions change. Fair Value of Financial Instruments Not Recorded at Fair Value The carrying amount and fair value information of financial instruments not recorded at fair value in their entirety on a recurring basis on the Company's consolidated balance sheets at December 31, 2017 and 2016 , were as follows: Fair Value December 31, 2017 Carrying Amount Level 1 Level 2 Level 3 Financial assets Cash and cash equivalents $ 293,456 $ 293,456 $ — $ — Securities held to maturity 173,509 — 174,926 — Loans held for investment, net 6,584,529 — — 6,651,207 Loans held for investment - Warehouse Purchase Program 1,154,588 — — 1,171,354 FHLB and other restricted securities, at cost 64,790 — 64,790 — Accrued interest receivable 24,596 24,596 — — Financial liabilities Deposits $ 6,767,683 $ — $ — $ 6,326,572 FHLB advances 1,043,163 — — 1,043,416 Repurchase agreements 84,676 — — 81,041 Subordinated debt 134,522 — — 141,972 Accrued interest payable 2,729 2,729 — — December 31, 2016 Financial assets Cash and cash equivalents $ 289,212 $ 289,212 $ — $ — Securities held to maturity 210,387 — 212,981 — Loans held for investment, net 5,998,596 — — 6,080,165 Loans held for investment - Warehouse Purchase Program 1,055,341 — — 1,055,219 FHLB and other restricted securities, at cost 43,266 — 43,266 — Accrued interest receivable 20,347 20,347 — — Financial liabilities Deposits $ 6,365,476 $ — $ — $ 5,989,933 FHLB advances 833,682 — — 830,930 Repurchase agreement 86,691 — — 84,265 Subordinated debt 134,032 — — 121,743 Accrued interest payable 2,111 2,111 — — The following methods and assumptions were used to estimate the fair values of each class of financial instrument presented: Cash and cash equivalents - Due to their short term nature, the carrying amount approximates the estimated fair value. Securities held to maturity - The fair values of these securities is determined by matrix pricing, which is a mathematical technique widely used in the industry to value debt securities without relying exclusively on quoted prices for the specific securities but rather by relying on the securities' relationship to other benchmark quoted securities (Level 2 inputs). Loans held for investment (including Warehouse Purchase Program loans) - Fair value is based on discounted cash flows using current market offering rates and estimated life. FHLB stock and other restricted securities - The fair value on these securities is their cost basis due to restrictions on transferability. Accrued interest receivable - Due to their short term nature, the carrying amount approximates the estimated fair value. Deposits - Fair value is calculated using the FHLB advance curve to discount cash flows based on the estimated life of the deposits. FHLB advances - Fair value is calculated using the FHLB advance curve to discount cash flows based on the contractual repayment schedule. Repurchase agreement - The fair value is based on discounting the estimated cash flows using the current rate at which similar borrowings would be made with similar terms and remaining maturities. Subordinated debt - The estimated fair value is based on current market rates on similar debt in the market. Accrued interest payable - Due to their short term nature, the carrying amount approximates the estimated fair value. The fair value of off-balance sheet items is based on the current fees or costs that would be charged to enter into or terminate such arrangements and are not considered significant to this presentation.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments The following table provides the outstanding notional balances and fair values of outstanding derivative positions at December 31, 2017 and 2016 . December 31, 2017 December 31, 2016 Outstanding Notional Balance Asset Derivative Fair Value Liability Derivative Fair Value Outstanding Notional Balance Asset Derivative Fair Value Liability Derivative Fair Value IRLCs $ 10,337 $ 358 $ — $ 10,952 $ 379 $ — Forward mortgage-backed securities trades 19,788 7 18 18,613 36 80 Commercial loan interest rate swaps and caps: Loan customer counterparty 114,594 — 1,735 112,294 — 1,369 Financial institution counterparty 114,594 1,735 — 112,294 1,369 — IRLCs - In the normal course of business, the Company enters into IRLCs with consumers to originate mortgage loans at a specified interest rate. These commitments, which contain fixed expiration dates, offer the borrower an interest rate guarantee provided the loan meets underwriting guidelines and closes within the timeframe established by the Company. Forward mortgage-backed securities trades - The Company manages the changes in fair value associated with changes in interest rates related to IRLCs by using forward sold commitments known as forward mortgage-backed securities trades. These instruments are typically entered into at the time the IRLC is made. Interest rate swaps and caps - These derivative positions relate to transactions in which we enter into an interest rate swap or cap with a customer, while at the same time entering into an offsetting interest rate swap or cap with another financial institution. An interest rate swap transaction allows our customer to effectively convert a variable rate loan to a fixed rate. In connection with each swap, we agree 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, we agree 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. In connection with each interest rate cap, we sell a cap to the customer and agree to pay interest if the underlying index exceeds the strike price defined in the cap agreement. Simultaneously we purchase a cap with matching terms from another financial institution which agrees to pay us if the underlying index exceeds the strike price. The commercial loan customer counterparty weighted average received and paid interest rates for interest rate swaps outstanding at December 31, 2017 and 2016 are presented in the following table. Weighted-Average Interest Rate December 31, 2017 December 31, 2016 Received Paid Received Paid Loan customer counterparty 2.52 % 2.54 % 3.12 % 2.36 % Our credit exposure on interest rate swaps is limited to the net favorable value of all swaps by each counterparty, which was approximately $32 at December 31, 2017 . This credit exposure is partly mitigated as transactions with customers are generally secured by the collateral, if any, securing the underlying transaction being hedged. Our credit exposure, net of collateral pledged, relating to interest rate swaps with upstream financial institution counter-parties was approximately $1,752 at December 31, 2017 . A credit support annex is in place and allows the bank to call collateral from upstream financial institution counter-parties. Collateral levels are monitored and adjusted on a regular basis for changes in interest rate swap values. Our cash collateral pledged for interest rate swaps and included in our interest-bearing deposits, which totaled $1,950 and $1,950 at December 31, 2017 and 2016 respectively, is in excess of our credit exposure. The initial and subsequent changes in the fair value of IRLCs and the forward sales of mortgage-back securities are recorded in net gain on sale of mortgage loans. These gains and losses were not attributable to instrument-specific credit risk. For interest rate swaps and caps, because we act as an intermediary for our customer, changes in the fair value of the underlying derivative contracts substantially offset each other and do not have a material impact on our results of operations. Income (loss) for the years ended December 31, 2017 , 2016 and 2015 was as follows: Derivatives not designated as hedging instruments Years Ended December 31, 2017 2016 2015 IRLC's $ (21 ) $ (43 ) $ 8 Forward mortgage-backed securities trades (479 ) 13 (195 )

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment Premises and equipment were as follows: December 31, 2017 2016 Land $ 22,140 $ 23,636 Buildings 57,079 59,298 Furniture, fixtures and equipment 20,218 19,561 Leasehold improvements 10,055 7,674 109,492 110,169 Less: accumulated depreciation (39,799 ) (35,943 ) Total $ 69,693 $ 74,226 Depreciation expense was $6,389 , $6,186 and $6,550 for 2017 , 2016 and 2015 , respectively. Operating Leases : The Company leases certain bank or loan production office properties and equipment under operating leases. Certain leases contain renewal options that may be exercised. Rent expense was $7,322 , $7,928 and $6,895 for 2017 , 2016 and 2015 , respectively. Rent commitments, before considering applicable renewal options, as of December 31, 2017 , were as follows: Balance 2018 $ 5,725 2019 5,069 2020 4,696 2021 4,443 2022 3,735 Thereafter 16,303 Total $ 39,971 The Company leases office space in certain locations to other unaffiliated tenants. Rental income of $1,102 was recognized during 2017 . This rental income is recorded in the consolidated statement of income as an offset to occupancy expense. Aggregate future minimum rental payments to be received under non-cancelable subleases at December 31, 2017 , were $105 . At December 31, 2017 , the Company had no commitments for future locations and held one parcel of land for future development. The Company sold a parcel of land in January 2017, resulting in a gain of $1,304 .

Goodwill and Core Deposit Intan

Goodwill and Core Deposit Intangibles	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Core Deposit Intangibles	Goodwill and Core Deposit Intangibles Changes in the carrying amount of the Company's goodwill and core deposit intangibles (“CDI”) for years ended December 31, 2017 and 2016 , were as follows: Goodwill Core Deposit Intangibles Balance as of December 31, 2015 $ 180,776 $ 1,030 Disposition of insurance subsidiary goodwill upon the sale of subsidiary operations (2,217 ) — Amortization of core deposit intangible — (365 ) Balance as of December 31, 2016 178,559 665 Amortization of core deposit intangible — (263 ) Balance as of December 31, 2017 $ 178,559 $ 402 CDI are amortized on an accelerated basis over their estimated lives with a weighted average amortization period of 8 years . The CDI amortization expense is reported in other non-interest expense on the Company's consolidated statements of income. The estimated aggregate future amortization expense for CDI remaining as of December 31, 2017 is as follows: Balance 2018 $ 156 2019 101 2020 73 2021 48 2022 24 Thereafter —

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Deposits	Deposits Time deposits of $250 or more totaled $1,009,855 and $951,688 at December 31, 2017 and 2016 , respectively. The $ 250 FDIC insurance coverage limit applies per depositor, per insured depository institution, for each account ownership category. At December 31, 2017 and 2016 , the Company had $400,716 and $355,455 in reciprocal deposits, respectively. These consisted entirely of certificates of deposit made under the Company's participation in the Certificate of Deposit Account Registry Service® (CDARS®) and Insured Cash Sweep (ICS) money market product. Through CDARS®, the Company can provide a depositor the ability to place up to $50,000 on deposit with the Company while receiving FDIC insurance on the entire deposit by placing customer funds in excess of the FDIC deposit limits with other financial institutions in the CDARS® network. In return, these financial institutions place customer funds with the Company on a reciprocal basis. Similarly, customer funds in our ICS money market product are swept from a transaction account at the Company into money market accounts at multiple banks to allow access to FDIC insurance coverage through multiple accounts, up to $75,000 . Regulators consider reciprocal deposits to be brokered deposits. At December 31, 2017 , scheduled maturities of time deposits for the next five years with the weighted average rate at the end of the period were as follows: Balance Weighted Average Rate 2018 $ 860,102 1.16 % 2019 383,687 1.57 2020 41,093 1.47 2021 59,074 1.59 2022 and thereafter 23,434 1.57 Total $ 1,367,390 1.31 % At December 31, 2017 and 2016 , the Company's deposits included public funds totaling $972,226 and $1,001,820 , respectively. At December 31, 2017 and 2016 , overdrawn deposits of $473 and $340 were reclassified as unsecured consumer loans. Interest expense on deposits is summarized as follows: Years Ended December 31, 2017 2016 2015 Interest-bearing demand $ 5,475 $ 3,974 $ 3,297 Savings and money market 16,845 7,288 3,644 Time 14,374 9,772 6,186 Total $ 36,694 $ 21,034 $ 13,127

Borrowed Funds

Borrowed Funds	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Borrowed Funds	Borrowed Funds Borrowed funds are summarized as follows: December 31, 2017 2016 Amount Rate 1 Amount Rate 1 Federal Home Loan Bank advances $ 1,043,163 1.51 % $ 833,682 0.71 % Repurchase Agreements Credit Suisse structured repurchase agreement 25,000 3.02 25,000 3.02 Overnight repurchase agreements with depositors 59,676 1.18 61,691 0.15 Subordinated Debt Fixed to floating rate note maturing on December 1, 2025 125,000 5.50 125,000 5.58 Junior subordinated debentures 15,464 3.29 15,464 2.66 1 Rate at period-end, with the exception of the fixed to floating rate subordinated debt note, which is a weighted average rate calculated using period-end rates. Federal Home Loan Bank ("FHLB") Advances At December 31, 2017 , advances from the FHLB had interest rates ranging from 1.30% to 6.00% . At December 31, 2016 , advances from the FHLB had interest rates ranging from 0.46% to 6.00% . At December 31, 2017 , the Company had $200,000 in variable rate FHLB advances. In 2010, certain FHLB fixed-rate advances were modified. The early repayment of the debt resulted in a prepayment penalty, which is being amortized to interest expense as an adjustment to the cost of the new FHLB advances. The prepayment penalty, net of accumulated amortization, was $0 and $27 at December 31, 2017 and 2016 . The amortization expense resulting from the prepayment penalty was fully amortized in September 2017. The FHLB advances were collateralized by mortgage and commercial loans with collateral values of $2,106,571 and $1,877,506 under a blanket lien arrangement at December 31, 2017 and 2016 , respectively. Additionally, securities safekept at FHLB and FHLB stock are used as collateral for advances. Based on this collateral, the Company was eligible to borrow an additional $2,084,944 and $1,821,693 at December 31, 2017 and 2016 , respectively. The current agreement provided for a maximum borrowing amount of approximately $4,072,477 and $3,601,739 at December 31, 2017 and 2016 , respectively. Repurchase Agreements Repurchase agreements ("repos") which are classified as securities transactions, are not insured by the FDIC, are not guaranteed, and may lose value. A repo is an agreement between two parties whereby one party (a bank as counterparty) sells the other (as customer) a security at a specified price with a commitment to buy the security back at a fixed time and price. Repos are accounted for as collateralized borrowings and are recorded at amounts equal to cash received. Inherent in repurchase agreements is a risk that the fair value of the collateral pledged on the agreements could decline below the amount obligated under the agreements. To mitigate this risk to the customer, the Company, as the bank counterparty, marks securities sold under repos to fair value on a daily basis and provides 115% market value protection on overnight repos and 112% market value protection on its structured repo. In April 2008, the Company entered into a 10 -year term structured repurchase callable agreement for $25,000 to leverage the balance sheet and increase liquidity. The interest rate adjusts quarterly to 6.25% less the 90 day LIBOR, subject to a lifetime cap of 3.02% . At December 31, 2017 , the Company also had $59,676 in overnight repurchase agreements with depositors. Subordinated Debt In November 2015, the Company issued $75,000 of Fixed-to-Floating Rate Subordinated Notes (the “Notes”) that mature on December 1, 2025 (the “Maturity Date”). In September 2016, the Company issued an additional $50,000 of Notes that mature on the Maturity Date. The Notes, which qualify as Tier 2 capital for regulatory purposes, have an interest rate of 5.50% and 5.69% , respectively, per annum, payable semi-annually on each December 1 and June 1 through December 1, 2020. From and including December 1, 2020 through maturity or earlier redemption, the interest rate will reset quarterly to an interest rate per annum equal to the then current three-month LIBOR rate plus 3.99% , payable on March 1, June 1, September 1, and December 1 of each year through the maturity date or earlier redemption. The Company may, at its option, beginning on December 1, 2020 and on any scheduled interest payment date thereafter, redeem the Notes, in whole or in part, at a redemption price equal to 100% of the principal amount of the Notes to be redeemed plus accrued and unpaid interest to, but excluding, the date of redemption. Any partial redemption will be made pro rata among all of the holders. The Notes were sold at an underwriting discount and the discount, as well as debt issuance costs, are netted against the subordinated debt liability on the balance sheet in accordance with ASU 2015-03. The unamortized underwriting discount and debt issuance costs totaled $2,405 at December 31, 2017 . The Notes are subordinated in right of payment to all of the Company's senior indebtedness and effectively subordinated to all existing and future debt and all other liabilities of the Company's subsidiaries. Upon the acquisition of LegacyTexas Group, Inc., the Company acquired $15,000 ( 15,000 shares with a liquidation amount of $1 per security) of Floating Rate Cumulative Trust Preferred Securities ("TruPS") and $464 of common stock through an unconsolidated subsidiary, Legacy Capital Trust III ("Trust III"). Trust III invested the total proceeds from the sale of TruPS and common stock (totaling $15,464 ) in floating rate Junior Subordinated Debentures (the "Trust III Debentures") issued by the Company. The terms of the Trust III Debentures are such that they qualify as Tier I capital for regulatory purposes. Interest on the Trust III Debentures is payable quarterly on March 15, June 15, September 15 and December 15 of each year, at a rate equal to the three month LIBOR rate plus 1.70% ( 3.29% at December 31, 2017 ). Principal is due at maturity on December 15, 2036. The TruPS are guaranteed by the Company and are subject to redemption. The Company may redeem the Trust III Debentures, in whole or in part, on any March 15, June 15, September 15 and December 15 at an amount equal to the principal amount being redeemed plus accrued and unpaid interest to the redemption date. At December 31, 2017 and 2016 , the Trust III Debentures were reduced by a purchase accounting fair value discount of $3,537 and $3,723 , respectively. Also upon the acquisition of LegacyTexas Group, Inc., the Company acquired $15,000 of TruPS and $464 of common stock through an unconsolidated subsidiary. The subsidiary invested the total proceeds from the sale of the TruPS and common stock in floating rate Junior Subordinated Debentures issued by LegacyTexas Group, Inc. On April 7, 2015, the Company paid this debt in full. Other Borrowing Information At December 31, 2017 , borrowed funds, reported gross of purchase accounting fair value discounts, prepayment penalties and debt issuance costs, were structured to contractually pay down as follows: FHLB Advances Repurchase Agreements Subordinated Debt Total 2018 $ 1,037,754 $ 84,676 $ — $ 1,122,430 2019 2,313 — — 2,313 2020 932 — — 932 2021 856 — — 856 2022 695 — — 695 Thereafter 613 — 140,464 141,077 $ 1,043,163 $ 84,676 $ 140,464 $ 1,268,303 Upon the acquisition of LegacyTexas Group, Inc., the Company assumed long-term notes totaling $8,900 . These notes were paid off during the first quarter of 2015. At December 31, 2017 and 2016 , the Company had borrowing availability representing the collateral value assigned to the securities pledged to the discount window through the FRB of $78,616 and $46,725 , respectively. Additionally, uncommitted, unsecured Fed Fund lines of credit totaling $250,000 and $255,000 were available at December 31, 2017 and 2016 , respectively, from multiple correspondent banks.

Benefits

Benefits	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Benefits	Benefits Employee Stock Ownership (“ESOP”) and 401(k) Plan : The Company offers a KSOP plan composed of an ESOP and 401(k) plan. Employees may participate under the 401(k) portion of the KSOP as of the date they first complete an hour of service with the Bank. Employees are eligible to receive a matching contribution of 100% of employee contributions up to a maximum of 5% of the employee's qualifying compensation. Matching expense for 2017 , 2016 and 2015 was $2,571 , $2,479 and $2,130 , respectively. The ESOP portion of the KSOP was established in connection with the Company's 2006 minority stock offering. In 2006 the ESOP purchased shares of common stock financed by a term loan from the Company. This note was fully repaid in September 2016, and all shares have been allocated to participant accounts. In 2010, in connection with our second step conversion to a full stock company, the ESOP purchased 1,588,587 shares of common stock with proceeds from a 30 year note in the amount of $15,886 from the Company. At December 31, 2017 , the ESOP held 2,298,076 shares, of which 1,105,983 shares were allocated to participants and 1,192,093 were unallocated. The fair value of unallocated shares at December 31, 2017 was $50,318 . The Company's Board of Directors determines the amount of contribution to the ESOP annually but is required to make contributions sufficient to service the ESOP's debt. Dividends on unallocated shares held by the ESOP are applied to the ESOP note payable. Shares are released for allocation to eligible employees as the ESOP debt is repaid. Eligible employees receive an allocation of released shares at the end of the calendar year on a relative compensation basis. Employees are eligible if they meet the minimum service and eligibility requirements. The dividends paid on allocated shares are paid to employee accounts. Contributions to the ESOP were $842 , $1,468 , and $2,060 during 2017 , 2016 and 2015 , and expense was $2,074 , $3,174 and $4,914 for December 31, 2017 , 2016 and 2015 , respectively. Deferred Compensation Plan : The Company has entered into certain non-qualified deferred compensation agreements with members of the executive management team, directors and certain employees. These agreements, which are subject to the rules of section 409(a) of the Internal Revenue Code, relate to the voluntary deferral of compensation received and do not have an employer contribution. The accrued liability as of December 31, 2017 and 2016 was $3,393 and $3,344 , respectively. Included in other assets is a universal life insurance policy, as well as variable and fixed annuity contracts, totaling $3,588 and $3,534 at December 31, 2017 and 2016 , respectively. The Company is the owner and beneficiary of the policy, which pays interest on the funds invested. The life insurance policy is recorded at the net cash surrender value, or the amount that can be realized. Bank-Owned Life Insurance : The Company is the sole owner of life insurance policies pertaining to certain employees and directors. The selected insured employees and directors agreed to a share of the death benefit while they remain actively employed with the Company or serve on its board. In the event of death while actively employed with the Company, the employee's or director's designated beneficiary will receive an income tax free death benefit paid. The Company also is the sole owner of other life insurance policies that do not share the death benefit with the employees. The total balance of the bank-owned life insurance policies, reported as an asset, at December 31, 2017 and 2016 totaled $57,684 and $56,477 .

Share-based Compensation

Share-based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based Compensation	Share-based Compensation The 2017 Omnibus Incentive Plan (the "2017 Plan") was approved at the Company's 2017 annual meeting of shareholders, held on May 22, 2017. Prior to approval of the 2017 Plan by shareholders, the Company had in effect the 2012 and 2007 Equity Incentive Plans (the “Prior Plans” and together with the 2017 Plan, the “Plans”). No further awards will be made under the Prior Plans and shares reserved to make new awards under the Prior Plans have been released; however, shares reserved to fund issued and outstanding awards under the Prior Plans continue to be reserved to provide for those awards. All awards outstanding under the Prior Plans remain outstanding in accordance with their terms. Each outstanding award under the Prior Plans continue to be governed solely by the terms of the documents evidencing such award, and no provision of the 2017 Plan is deemed to affect or otherwise modify the rights or obligations of the holders of such awards with respect to their acquisition of Company shares. The 2017 Plan permits the granting of non-qualified stock options, incentive stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance units and cash awards to participants. Eligible participants under the 2017 Plan include employees and directors (including advisory and emeritus directors) of the Company and its subsidiaries. There are 3,250,000 total shares authorized under the 2017 Plan, with a fungible share rate of 2.5 -for-1 for full-value awards (stock-based awards other than stock options and stock appreciation rights). As of December 31, 2017 , 10,500 shares had been issued under the 2017 Plan. Compensation cost charged to income for share-based compensation, which is reported in non-interest expense as salaries and employee benefits expense, is presented below: Years ended December 31, 2017 2016 2015 Restricted stock $ 3,581 $ 3,477 $ 3,459 Stock options 3,881 2,537 2,018 Income tax benefit 2,612 2,105 1,917 A summary of activity in the restricted stock portion of the Company's Plans for 2017 , 2016 and 2015 is presented below: Time-Vested Shares Performance-Based Shares Shares Weighted- Average Grant Date Fair Value per Share 1 Shares Weighted- Average Grant Date Fair Value per Share 2 Non-vested at January 1, 2015 297,603 $ 20.45 82,400 $ 23.89 Granted 80,000 21.23 — — Vested (131,142 ) 19.98 (20,600 ) 23.89 Non-vested at December 31, 2015 246,461 20.98 61,800 25.02 Granted 55,180 29.29 40,200 29.29 Vested (101,465 ) 20.70 (20,600 ) 25.02 Non-vested at December 31, 2016 200,176 23.79 81,400 43.06 Granted 19,208 38.92 12,208 39.90 Vested (90,796 ) 21.67 (20,600 ) 41.32 Non-vested at December 31, 2017 128,588 $ 27.27 73,008 $ 42.21 1 For restricted stock awards with time-based vesting conditions, the grant date fair value is based upon the closing stock price as quoted on the Nasdaq Stock Market on the grant date. 2 For restricted stock awards with performance-based vesting conditions, the value of the award is based upon the closing stock price as quoted on the Nasdaq Stock Market on the date of vesting. Until the final value is determined on the vesting date, the Company estimates the fair value based upon the closing stock price as quoted on the Nasdaq Stock Market near the last business day of each month. As of December 31, 2017 , there was $2,887 of total unrecognized compensation expense related to non-vested restricted shares awarded under the Company's Plans. That expense is expected to be recognized over a weighted-average period of 1.1 years . The total fair value of shares vested during the years ended December 31, 2017 and 2016 , was $2,819 and $2,615 , respectively. Under the terms of the 2017 Plan, stock options may not be granted with an exercise price less than the fair market value of the Company’s common stock on the date the option is granted and may not be exercised later than ten years after the grant date. The fair market value is the closing stock price as quoted on the Nasdaq Stock Market on the date of grant. The fair value of each option award is estimated on the date of grant using a closed form option valuation (Black-Scholes) model that uses the assumptions noted in the table below. The risk-free interest rate is the implied yield available on U.S. Treasury zero-coupon issues with a remaining term equal to the expected term of the stock option in effect at the time of the grant. The expected term of stock options is based on employees' actual vesting behavior and expected volatilities are based on historical volatilities of the Company’s common stock. Expected dividends are the estimated dividend rate over the expected term of the stock options. The weighted average fair value of stock options granted during 2017 , 2016 and 2015 was $10.76 , $7.77 and $6.82 , respectively. The fair value of options granted was determined using the following weighted-average assumptions as of grant date: 2017 2016 2015 Risk-free interest rate 2.18 % 1.37 % 1.80 % Expected term of stock options (years) 6.2 6.3 6.2 Expected stock price volatility 31.85 % 32.07 % 31.14 % Expected dividends 1.61 % 1.93 % 1.95 % A summary of activity in the stock option portion of the Company's Plans as of the years ended December 31, 2017 , 2016 and 2015 is presented below: Options Shares Weighted- Average Exercise Price per Share Weighted- Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at January 1, 2015 1,370,873 $ 20.27 8.0 $ 5,679 Granted 633,000 25.66 Exercised (58,855 ) 16.12 Forfeited (79,268 ) 20.89 Outstanding at December 31, 2015 1,865,750 22.21 7.9 6,401 Granted 392,838 29.15 Exercised (175,192 ) 19.08 Forfeited (75,316 ) 25.57 Outstanding at December 31, 2016 2,008,080 23.71 9.5 38,850 Granted 513,375 37.15 Exercised (221,984 ) 21.23 Forfeited (92,228 ) 28.80 Outstanding at December 31, 2017 2,207,243 $ 26.88 10.1 $ 33,848 Fully vested and expected to vest 2,191,740 $ 26.82 10.1 $ 33,725 Exercisable at December 31, 2017 966,527 $ 22.11 7.5 $ 19,425 As of December 31, 2017 , there was $8,013 of total unrecognized compensation expense related to non-vested stock options. That expense is expected to be recognized over a weighted-average period of 1.9 years . At December 31, 2017 , the Company applied an estimated forfeiture rate of 5% based on historical activity. The intrinsic value for stock options is calculated based on the difference between the exercise price of the underlying awards and the market price of our common stock as of the reporting date. The total intrinsic value of stock options exercised was $4,084 , $2,251 and $644 for years ended December 31, 2017 , 2016 and 2015 , respectively. Effective January 1, 2017, the Company changed the accounting for income taxes upon the vesting of stock options and restricted stock to be in accordance with ASC 718, as modified by ASU 2016-09, Improvements to Employee Share-Based Payment Accounting . Prior to the implementation of ASU 2016-09, the tax effects of income tax deductions in excess of compensation cost (windfalls) were recorded in additional paid-in capital, and the tax effects of compensation cost in excess of income tax deductions (shortfalls) were recorded in additional paid-in capital to the extent of previously recognized windfalls, with the remainder recorded in income tax expense. Under ASU 2016-09, all tax effects of windfalls and shortfalls related to share-based payments are recorded through the income statement. Prior period balances were not adjusted. For the year ended December 31, 2017 , we recognized income tax deductions in excess of compensation cost of $4,510 for share-based payment awards, which resulted in a tax benefit of $1,578 recorded as a reduction of income tax expense. The classification of excess tax benefits on the statement of cash flows will be shown as an operating activity.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Tax Cuts and Jobs Act (the "Act",) which was enacted on December 22, 2017, made key changes to the U.S. tax law, including the reduction of the U.S. federal corporate tax rate from 35% to 21%. As ASC 740, Income Taxes , requires the effects of changes in tax rates and laws on deferred tax balances to be recognized in the period in which the legislation is enacted, the Company remeasured its deferred tax assets and liabilities based on the rates at which they are expected to reverse in the future, which is 21%. The Company is still analyzing certain aspects of the Act, and refining its calculations, which could potentially affect the measurement of these balances or give rise to new deferred tax amounts. The provisional amount recorded related to the remeasurement of our deferred tax asset was $13,493 . Additionally, related to the deferred tax effects on the unrealized holding gains and losses for available for sale securities, the effect of the Act was recorded as a component of tax expense related to continuing operations during 2017, which is consistent with ASC 740's general prohibition on backward tracing. The Company's pre-tax income is subject to federal income tax and state margin tax at a combined rate of 36% for 2017 , 2016 and 2015 . Income tax expense for 2017 , 2016 and 2015 , was as follows: 2017 2016 2015 Current expense $ 56,341 $ 59,900 $ 38,648 Deferred expense (4,115 ) (6,798 ) (692 ) Impact of Tax Cuts and Jobs Act - net future deductions 12,752 — — Impact of Tax Cuts and Jobs Act - unrealized loss on AFS securities 741 — — Total income tax expense $ 65,719 $ 53,102 $ 37,956 At December 31, 2017 and 2016 , deferred tax assets and liabilities were due to the following: December 31, 2017 2016 Deferred tax assets: Allowance for loan losses $ 15,168 $ 22,602 Deferred compensation arrangements 762 1,261 Self-funded health insurance 251 241 Non-accrual interest 503 966 Restricted stock and stock options 2,577 3,132 Accrued expenses 623 1,255 Fair value mark on purchased loans 965 2,348 Net unrealized loss on securities available for sale 1,111 1,465 Other 1,909 2,121 23,869 35,391 Deferred tax liabilities: Depreciation (270 ) (336 ) Partnerships — CRA-purposed private equity funds (941 ) (1,697 ) Fair value mark on subordinated debt (743 ) (1,303 ) Other (1,675 ) (2,824 ) (3,629 ) (6,160 ) Net deferred tax asset $ 20,240 $ 29,231 The net deferred tax asset is recorded on the consolidated balance sheets under “other assets.” Management performed an analysis related to the Company's deferred tax asset for each of the years ended December 31, 2017 and 2016 and, based upon these analyses, no valuation allowance was deemed necessary as of December 31, 2017 or 2016 . Effective tax rates differ from the federal statutory rate of 35% in 2017 , 2016 and 2015 , applied to income before income taxes due to the following: At and for the Year Ended December 31, 2017 2016 2015 Federal statutory rate times financial statement income $ 54,325 $ 52,823 $ 38,105 Effect of: State taxes, net of federal benefit 239 267 37 Bank-owned life insurance income (423 ) (436 ) (419 ) Municipal interest income (978 ) (1,041 ) (1,025 ) ESOP shares released 541 757 1,207 Restricted stock and stock options (1,578 ) — — Sale of LegacyTexas Insurance Services, Inc. — 640 — DTA write-down due to the Tax Cuts and Jobs Act 13,493 — — Other 100 92 51 Total income tax expense $ 65,719 $ 53,102 $ 37,956 Effective Tax Rate before deferred tax write-down 33.65 % 35.18 % 34.86 % Effective Tax Rate 42.34 % 35.18 % 34.86 % The Company files income tax returns in the U.S. federal jurisdiction and several U.S. state jurisdictions. The Company is generally no longer subject to U.S. federal income tax examinations for tax years prior to 2014 .

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Loans to executive officers, directors, and their affiliates during 2017 were as follows: Balance Beginning balance $ 15,337 New loans — Effect of changes in composition of related parties — Repayments (933 ) Ending balance $ 14,404 None of the above loans were considered non-performing or potential problem loans. These loans are made in the ordinary course of business and on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with other unaffiliated persons and do not involve more than normal risk of collectability. Deposits from executive officers, directors, and their affiliates at December 31, 2017 and 2016 were $39,615 and $48,761 , respectively.

Regulatory Capital Matters

Regulatory Capital Matters	12 Months Ended
	Dec. 31, 2017
Regulatory Capital Requirements [Abstract]
Regulatory Capital Matters	Regulatory Capital Matters Banks and bank holding companies are subject to regulatory capital requirements administered by federal banking agencies. Capital adequacy guidelines and, additionally for banks, prompt corrective action regulations, involve quantitative measures of assets, liabilities, and certain off‑balance sheet items calculated under regulatory accounting practices. Capital amounts and classifications are also subject to qualitative judgments by regulators. Failure to meet capital requirements can initiate regulatory action. The Bank and the Company are regulated by the Texas Department of Banking ("TDOB") and the Board of Governors of the Federal Reserve System ("FRB"). The ability of a subsidiary bank to pay dividends depends on its earnings and capital levels and may be limited by their regulator's directives or orders. A bank generally must obtain regulatory approval of a dividend if the total dividends declared during the current year, including the proposed dividend, exceed net income for the current year and retained net income for the prior two years. Prompt corrective action regulations provide five classifications: well-capitalized, adequately capitalized, undercapitalized, significantly undercapitalized and critically undercapitalized, although these terms are not used to represent overall financial condition. If an institution is adequately capitalized, regulatory approval is required to accept brokered deposits. If an institution is undercapitalized, capital distributions are limited, as is asset growth and expansion, and capital restoration plans are required. At December 31, 2017 and 2016 , the most recent regulatory notification categorized the Bank and the Company as well-capitalized under the regulatory framework for prompt corrective action. There are no conditions or events since that notification that management believes have changed the institution's category. Management believes that, at December 31, 2017 , the Bank and the Company met all capital adequacy requirements to which they were subject. Actual Required for Capital Adequacy Purposes To Be Well-Capitalized Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017 Total risk-based capital Company $ 991,713 11.87 % $ 668,142 8.00 % $ 835,178 10.00 % Bank 939,655 11.25 668,096 8.00 835,120 10.00 Tier 1 risk-based capital Company 796,887 9.54 501,107 6.00 501,107 6.00 Bank 867,424 10.39 501,072 6.00 668,096 8.00 Common equity tier 1 risk-based capital Company 784,960 9.40 375,830 4.50 n/a 1 n/a 1 Bank 867,424 10.39 375,804 4.50 542,828 6.50 Tier 1 leverage Company 796,887 9.17 347,731 4.00 n/a 1 n/a 1 the Bank 867,424 9.98 347,808 4.00 434,759 5.00 As of December 31, 2016 Total risk-based capital Company $ 910,040 11.71 % $ 621,870 8.00 % $ 777,338 10.00 % Bank 869,523 11.19 621,840 8.00 777,300 10.00 Tier 1 risk-based capital Company 721,600 9.28 466,403 6.00 466,403 6.00 Bank 803,374 10.34 466,380 6.00 621,840 8.00 Common equity tier 1 risk-based capital Company 709,858 9.13 349,802 4.50 n/a 1 n/a 1 Bank 803,374 10.34 349,785 4.50 505,245 6.50 Tier 1 leverage Company 721,600 8.73 330,782 4.00 n/a 1 n/a 1 Bank 803,374 9.71 330,873 4.00 413,591 5.00 1 Not applicable

Commitments and Contingent Liab

Commitments and Contingent Liabilities	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	Commitments and Contingent Liabilities In the normal course of business, the Company enters into various transactions which, in accordance with US GAAP, are not included in its consolidated balance sheets. The Company enters into these transactions to meet the financing needs of its customers. These transactions include commitments to extend credit and standby letters of credit which involve, to varying degrees, elements of credit and interest rate risk. Credit losses up to the face amount of these instruments could occur, although material losses are not anticipated. The Company's credit policies applied to loan originations are also applied to these commitment requests, including obtaining collateral at the exercise of the commitment. The contractual amounts of financial instruments with off‑balance sheet risk at December 31, 2017 and 2016 , are summarized below. Please see Part II-Item 7- "Off-Balance Sheet Arrangements, Contractual Obligation and Commitments" of this Form 10-K for information related to commitment maturities. December 31, 2017 2016 Unused commitments to extend credit $ 1,600,794 $ 1,642,528 Unused capacity on Warehouse Purchase Program loans 738,412 892,659 Standby letters of credit 34,091 29,198 Total unused commitments/capacity $ 2,373,297 $ 2,564,385 Unused commitments to extend credit - The Company enters into contractual commitments to extend credit, normally with fixed expiration dates or termination clauses, at specified rates and for specific purposes. Since many commitments expire without being drawn upon, the total contractual amount of commitments does not necessarily represent future cash requirements of the Company. Substantially all of the Company's commitments to extend credit are contingent upon customers maintaining specific credit standards at the time of future loan funding. Unused capacity on Warehouse Purchase Program loans - In regard to unused capacity on Warehouse Purchase Program loans, the Company has established maximum purchase facility amounts, but reserves the right, at any time, to refuse to buy any mortgage loans offered for sale by each customer, for any reason in the Company's sole and absolute discretion. Standby letters of credit - Standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. In addition to the commitments above, the Company guarantees the credit card debt of certain customers to the merchant bank that issues the credit cards. These guarantees are in place for as long as the guaranteed credit card is open. At December 31, 2017 and 2016 , these credit card guarantees totaled $5,257 and $3,335 , respectively. This amount represents the maximum potential amount of future payments under the guarantee, which the Company is responsible for in the event of customer non-payment. The Company funds an allowance for credit losses on off-balance sheet lending-related commitments and guarantees on credit card debt through a charge to provision for credit losses on the Company's consolidated statement of income. At December 31, 2017 and 2016 , this allowance for credit losses on off-balance sheet lending-related commitments and guarantees on credit card debt, included in "other liabilities" on the Company's consolidated balance sheets, totaled $929 and $1,573 respectively. In addition to the commitments above, the Company had overdraft protection available in the amounts of $84,727 and $85,709 at December 31, 2017 and 2016 , respectively. The Company, at December 31, 2017 , had FHLB letters of credit of $944,370 pledged to secure public deposits, repurchase agreements, and for other purposes required or permitted by law. At December 31, 2017 , the Company had $1,680 of unfunded commitments recorded in other liabilities in its consolidated balance sheet related to investments in community development-oriented private equity funds used for Community Reinvestment Act purposes. The total investment in these equity funds was $11,223 , with an average ownership of 6.2% . Liability for Mortgage Loan Repurchase Losses Residential mortgage loans are sold in the secondary market with standard representations and warranties regarding certain characteristics such as the quality of the loan, the absence of fraud, the eligibility of the loan for sale and the future servicing associated with the loan. The Company may be required to repurchase these loans at par, or make-whole or indemnify the purchasers for losses incurred when representations and warranties are breached. The Company maintains a repurchase liability related to residential mortgage loans sold with representations and warranty provisions. This repurchase liability, reported in other liabilities on the consolidated balance sheets, reflects management’s estimate of losses based on historical repurchase and loss trends, as well as other factors that may result in anticipated losses different from historical loss trends. Adjustments to this reserve are recorded in other non-interest expense on the consolidated statements of income. The liability was $131 and $143 at December 31, 2017 and 2016 , respectively.

Parent Company Only Condensed F

Parent Company Only Condensed Financial Information	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Parent Company Only Condensed Financial Information	Parent Company Only Condensed Financial Information Condensed financial information of the Company is as follows: CONDENSED BALANCE SHEETS December 31, 2017 2016 ASSETS Cash on deposit at subsidiary $ 26,692 $ 16,962 Investment in banking subsidiary 1,042,338 978,880 Receivable from banking subsidiary 12,278 10,317 ESOP note receivable and other assets 13,814 13,999 Total assets $ 1,095,122 $ 1,020,158 LIABILITIES AND SHAREHOLDERS’ EQUITY Borrowings $ 134,522 $ 134,032 Other liabilities 726 761 Shareholders’ equity 959,874 885,365 Total liabilities and shareholders’ equity $ 1,095,122 $ 1,020,158 CONDENSED STATEMENTS OF INCOME December 31, 2017 2016 2015 Cash dividends from subsidiary $ 35,000 $ — $ 24,500 Excess of earnings over dividend from subsidiary 61,341 103,572 48,677 Interest income on ESOP loan 449 487 565 Interest income on subordinated debt 13 11 17 Other income — — 5 96,803 104,070 73,764 Interest expense 7,819 6,040 1,046 Operating expenses 3,754 3,236 3,009 Earnings before income tax benefit 85,230 94,794 69,709 Income tax benefit 4,264 3,027 1,207 Net income $ 89,494 $ 97,821 $ 70,916 CONDENSED STATEMENTS OF CASH FLOWS December 31, 2017 2016 2015 Cash flows from operating activities Net income $ 89,494 $ 97,821 $ 70,916 Adjustments to reconcile net income to net cash from operating activities: Excess of earnings over dividend from subsidiary (61,341 ) (103,572 ) (48,677 ) Amortization 490 530 171 Activity in share-based compensation plans 5,501 3,152 3,068 Net change in other assets (207 ) (481 ) 6,931 Net change in other liabilities (35 ) (38 ) (14,544 ) Net cash provided by (used in) operating activities 33,902 (2,588 ) 17,865 Cash flows from investing activities Capital contribution (to) from subsidiary — (49,000 ) (40,000 ) Cash and cash equivalents acquired from LegacyTexas Group, Inc. — — 201 Payments received on ESOP notes receivable 393 981 1,495 Net cash provided by (used in) investing activities 393 (48,019 ) (38,304 ) Cash flows from financing activities Proceeds from borrowings — 73,439 73,407 Repayments of borrowings — (24,929 ) (24,364 ) Share repurchase — — (7,989 ) Net issuance of common stock under employee stock plans 4,712 3,755 1,284 Payment of dividends (29,277 ) (27,676 ) (25,747 ) Net cash provided by (used in) financing activities (24,565 ) 24,589 16,591 Net change in cash and cash equivalents 9,730 (26,018 ) (3,848 ) Beginning cash and cash equivalents 16,962 42,980 46,828 Ending cash and cash equivalents $ 26,692 $ 16,962 $ 42,980

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	Quarterly Financial Data (Unaudited) Interest Income Interest Expense Net Interest Income Provision Securities Gains and (Losses) Net Income Earnings per Share Basic Diluted 2017 First quarter $ 87,536 $ 10,988 $ 76,548 $ 22,301 1 $ (19 ) $ 18,190 0.39 0.38 Second quarter 88,747 13,027 75,720 6,255 — 27,935 0.60 0.59 Third quarter 94,463 15,499 78,964 7,157 (20 ) 28,709 0.61 0.61 Fourth quarter 96,111 15,912 80,199 3,743 — 14,660 2 0.31 0.31 2016 First quarter $ 72,608 $ 7,257 $ 65,351 $ 8,800 $ — $ 22,082 0.48 0.48 Second quarter 77,336 7,982 69,354 6,800 65 23,217 0.50 0.50 Third quarter 82,911 9,431 73,480 3,467 (3 ) 27,217 0.59 0.58 Fourth quarter 84,497 10,413 74,084 7,833 (6 ) 25,305 0.54 0.54 1 Includes the impact of a charge-off totaling $16,360 on a corporate healthcare finance relationship, which was reported in the Company's commercial and industrial loan portfolio. 2 Includes the impact of a $13,493 income tax adjustment to the Company's deferred tax asset related to the December 22, 2017 enactment of the Tax Cuts and Jobs Act.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company evaluated events from the date of the consolidated financial statements on December 31, 2017 through the issuance of those consolidated financial statements included in this Annual Report on Form 10-K dated February 8, 2018 .

Summary of Significant Accoun29

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation : The consolidated financial statements include LegacyTexas Financial Group, Inc. (the "Company"), whose business at December 31, 2017 primarily consisted of the operations of its wholly-owned subsidiary, LegacyTexas Bank (the "Bank"). In addition, the Company also offers title services through LegacyTexas Title Co., which is a wholly-owned subsidiary of the Bank. Intercompany transactions and balances are eliminated in consolidation.
Use of Estimates	Use of Estimates : To prepare financial statements in conformity with U.S. generally accepted accounting principles ("US GAAP"), management makes estimates and assumptions based on available information. These estimates and assumptions affect the amounts reported in the financial statements and the disclosures provided, and actual results could differ. The allowance for loan losses, valuation of other real estate owned, other-than-temporary impairment of securities, realization of deferred tax assets, and fair values of financial instruments are subject to change.
Cash Flows	Cash Flows : Cash and cash equivalents include cash, deposits with other financial institutions with maturities less than 90 days, and federal funds sold. Net cash flows are reported for customer loan and deposit transactions, interest-bearing deposits in other financial institutions, federal funds purchased, Federal Home Loan Bank advances and repurchase agreements.
Restrictions on Cash	Restrictions on Cash : The Company maintains deposits with other financial institutions in amounts that exceed federal deposit insurance coverage. Management regularly evaluates the credit risk associated with the counterparties to these transactions and believes that the Company is not exposed to any significant credit risks on cash and cash equivalents. Cash balances equaling or exceeding escrow amounts are maintained at correspondent banks.
Securities	Securities : Securities that the Company has both the positive intent and ability to hold to maturity are classified as held to maturity and are carried at amortized cost. Securities that the Company intends to hold for an indefinite period of time, but not necessarily to maturity, are classified as available for sale and are carried at fair value. Unrealized gains and losses on securities classified as available for sale have been accounted for as accumulated other comprehensive income (loss), net of taxes. Gains and losses on the sale of securities classified as available for sale are recorded on the trade date using the specific-identification method. Amortization of premiums and discounts are recognized in interest income over the period to maturity. Premiums and discounts on securities are amortized using the level-yield method without anticipating prepayment, except for mortgage-backed securities where prepayments are anticipated.
Other-than-Temporary Impairment	The Company evaluates securities for other-than-temporary impairment on at least a quarterly basis and more frequently when economic, market, or security specific concerns warrant such evaluation. Consideration is given to the length of time and the extent to which the fair value has been less than amortized cost, the financial condition and near-term prospects of the issuer, whether the market decline was affected by macroeconomic conditions and whether the Company has the intent and ability to retain its investment in the issuer for a period of time sufficient to allow for any anticipated recovery in fair value. In analyzing an issuer’s financial condition, the Company may consider whether the securities are issued by the federal government or its agencies, whether downgrades by bond rating agencies have occurred, and the results of reviews of the issuers’ financial condition. The Company conducts regular reviews of the bond agency ratings of securities and considers whether the securities were issued by or have principal and interest payments guaranteed by the federal government or its agencies. These reviews focus on the underlying rating of the issuer and also include the insurance rating of securities that have an insurance component or guarantee. The ratings and financial condition of the issuers are monitored, as well as the financial condition and ratings of the insurers and guarantors. For periods in which other-than-temporary impairment of a debt security is recognized, the credit portion of the amount is determined by subtracting the present value of the stream of estimated cash flows as calculated in a discounted cash flow model and discounted at book yield from the prior period’s ending carrying value. The non-credit portion of the amount is determined by subtracting the credit portion of the impairment from the difference between the book value and fair value of the security. The credit related portion of the impairment is charged against income and the non-credit related portion is charged to equity as a component of accumulated other comprehensive income.
Mortgage Loans Held for Sale	Mortgage Loans Held for Sale : The Company elects the fair value option for recording residential mortgage loans held for sale in accordance with Accounting Standards Codification ("ASC") 825, "Financial Instruments." This election allows for a more effective offset of the changes in fair values of the loans and the derivative instruments used to economically hedge them without the burden of complying with the requirements for hedge accounting under ASC 815, “Derivatives and Hedging.”
Warehouse Purchase Program Loans and Loans	Warehouse Purchase Program Loans : The Warehouse Purchase Program allows unaffiliated mortgage originators to close one- to four-family real estate loans in their own name and manage their cash flow needs until the loans are sold to investors. The mortgage banking company customer closes mortgage loans consistent with underwriting standards established by the Bank and approved investors and, once all pertinent documents are received, the participation interest is delivered by the Bank to the investor selected by the originator and approved by us. Although not bound by any legally binding commitment, when a purchase decision is made, we purchase a 100% participation interest in the mortgage loans originated by our mortgage banking company customers. All Warehouse Purchase Program loans are collectively evaluated for impairment and are purchased under several contractual requirements, providing safeguards to the Company. These safeguards include the requirement that our mortgage company customers have a takeout commitment or similar arrangement for each loan. To date, the Company has not experienced a loss on these loans and no allowance for loan losses has been allocated to them. Loans : Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at the principal balance outstanding, net of unearned interest, purchase premiums and discounts, deferred loan fees and costs, and an allowance for loan losses. Interest income is accrued on the unpaid principal balance. Loan origination fees, net of certain direct origination costs, are deferred and recognized in interest income using the level-yield method without anticipating prepayments. Past due status is based on the contractual terms of the loan. Loans that are past due 30 days are considered delinquent. Interest income on loans is discontinued at the time the loan is 90 days delinquent unless the loan is well-secured and in process of collection. Non-mortgage consumer loans are typically charged off no later than 120 days past due. In all cases, loans are placed on nonaccrual status or charged-off at an earlier date if collection of principal or interest is considered doubtful. Nonaccrual loans include both smaller balance homogeneous loans that are collectively evaluated for impairment and larger individually classified impaired loans. All interest accrued but not received for loans placed on nonaccrual status is reversed against interest income. Subsequent receipts on non-accrual loans are recorded as a reduction of principal, and interest income is recorded only after principal recovery is reasonably assured. Loans are returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured. For loans collateralized by real property and commercial and industrial loans, credit exposure is monitored by internally assigned grades used for classification of loans. A loan is considered “special mention” when management has determined that there is a potential weakness that deserves management's close attention. Loans rated as "special mention" are not adversely classified according to regulatory classifications and do not expose the Company to sufficient risk to warrant adverse classification. A loan is considered “substandard” if it is inadequately protected by the current net worth and paying capacity of the obligor or the collateral pledged, if any. “Substandard” loans include those characterized by the “distinct possibility” that the insured institution will sustain “some loss” if the deficiencies are not corrected, and the loan may or may not meet the criteria for impairment. Loans classified as “doubtful” have all of the weaknesses of those classified as “substandard” with the added characteristic that the weaknesses present makes “collection or liquidation in full,” on the basis of currently existing facts, conditions and values, “highly questionable and improbable.” All other loans that do not fall into the above mentioned categories are considered “pass” loans. Updates to internally assigned grades are made monthly and/or upon significant developments. For other consumer loans (non-real estate), credit exposure is monitored by payment history of the loans. Non-performing other consumer loans are on nonaccrual status and are generally greater than 90 days past due.
Acquired Loans	Acquired Loans : Loans acquired through the completion of a transfer, including loans acquired in a business combination, that have evidence of deterioration of credit quality since origination and for which it is probable, at acquisition, that the Company will be unable to collect all contractually required payments receivable are initially recorded at fair value (as determined by the present value of expected future cash flows) with no valuation allowance. The difference between the undiscounted cash flows expected at acquisition and the investment in the loan, or the “accretable yield,” is recognized as interest income on a level-yield method over the life of the loan. Contractually required payments for interest and principal that exceed the undiscounted cash flows expected at acquisition, or the “nonaccretable difference,” are not recognized on the balance sheet and do not result in any yield adjustments, loss accruals or valuation allowances. Increases in expected cash flows, including prepayments, subsequent to the initial investment are recognized prospectively through adjustment of the yield on the loan over its remaining life. Decreases in expected cash flows are recognized as impairment. Valuation allowances on these impaired loans reflect only losses incurred after the acquisition (meaning the present value of all cash flows expected at acquisition that ultimately are not to be received). Revolving loans, including lines of credit, are excluded from acquired credit impaired loan accounting. For acquired loans not deemed credit-impaired at acquisition, the differences between the initial fair value and the unpaid principal balance are recognized as interest income on a level-yield basis over the lives of the related loans. Subsequent to the acquisition date, methods utilized to estimate the required allowance for loan losses for these loans is similar to originated loans; however, a provision for credit losses will be recorded only to the extent the required allowance exceeds any remaining credit discounts.
Concentration of Credit Risk	Concentration of Credit Risk : Most of the Company’s business activity is with customers located within the North Texas region and a large portion of loans are secured by real estate in this area. Therefore, the Company’s exposure to credit risk is significantly affected by changes in the economy of the North Texas area.
Allowance for Loan Losses	Allowance for Loan Losses : The allowance for loan losses and related provision expense are susceptible to change if the credit quality of our loan portfolio changes, which is evidenced by many factors, including but not limited to charge-offs and non-performing loan trends. Generally, consumer real estate lending has a lower credit risk profile compared to other consumer lending (such as automobile loans). Commercial real estate and commercial and industrial lending, however, can have higher risk profiles than consumer loans due to these loans being larger in amount and non-homogeneous in structure and term. Changes in economic conditions, the mix and size of the loan portfolio, and individual borrower conditions can dramatically impact our level of allowance for loan losses in relatively short periods of time. The allowance for loan losses is maintained to cover incurred losses that are estimated in accordance with US GAAP. It is our estimate of credit losses inherent in our loan portfolio at each balance sheet date. Our methodology for analyzing the allowance for loan losses consists of general and specific components. For the general component, we stratify the loan portfolio into homogeneous groups of loans that possess similar loss potential characteristics and apply a loss ratio to these groups of loans to estimate the credit losses in the loan portfolio. We use both historical loss ratios and qualitative loss factors assigned to major loan collateral types to establish general component loss allocations, inclusive of estimated loss emergence periods. Qualitative loss factors are based on management's judgment of company, market, industry or business specific data and external economic indicators, which are not yet reflected in the historical loss ratios, and that could impact the Company's specific loan portfolios. The Allowance for Loan Loss Committee sets and adjusts qualitative loss factors by regularly reviewing changes in underlying loan composition and the seasonality of specific portfolios. The Allowance for Loan Loss Committee also considers credit quality and trends relating to delinquency, non-performing and adversely rated loans within the Company's loan portfolio when evaluating qualitative loss factors. Additionally, the Allowance for Loan Loss Committee adjusts qualitative factors to account for the potential impact of external economic factors, including the unemployment rate, vacancy and capitalization rates and other pertinent economic data specific to our primary market area and lending portfolios. For the specific component, the allowance for loan losses includes loans where management has concerns about the borrower's ability to repay and on individually analyzed loans found to be impaired. Management evaluates current information and events regarding a borrower's ability to repay its obligations and considers a loan to be impaired when the ultimate collectability of amounts due, according to the contractual terms of the loan agreement, is in doubt. If an impaired loan is collateral-dependent, the fair value of the collateral, less the estimated cost to sell, is used to determine the amount of impairment. If an impaired loan is not collateral-dependent, estimated discounted cash flows are used to determine the amount of impairment, if any. For impaired loans, the amount of the impairment can be adjusted, based on current data, until such time as the actual basis is established by acquisition of the collateral or until the basis is collected. Impairment losses are reflected in the allowance for loan losses through a charge to the provision for credit losses. Subsequent recoveries are credited to the allowance for loan losses. Cash receipts for accruing loans are applied to principal and interest under the contractual terms of the loan agreement. Cash receipts on impaired loans for which the accrual of interest has been discontinued are applied first to principal. Large groups of smaller-balance homogeneous loans are collectively evaluated for impairment. As a result, the Company does not separately identify consumer real estate loans less than $417 or individual consumer non-real estate secured loans for impairment disclosures. The Company considers these loans to be homogeneous in nature due to the smaller dollar amount and the similar underwriting criteria. A loan that has been modified is considered a troubled debt restructuring (“TDR”) when two conditions are met: 1) the borrower is experiencing financial difficulty and 2) concessions are made for the borrower's benefit that would not otherwise be considered for a borrower or transaction with similar credit risk characteristics. Modifications to loan terms may include a modification of the contractual interest rate to a below-market rate (even if the modified rate is higher than the original rate), forgiveness of accrued interest, forgiveness of a portion of principal, an extended repayment period or a deed in lieu of foreclosure or other transfer of assets other than cash to fully or partially satisfy a debt. The Company's policy is to place all TDRs on nonaccrual for a minimum period of six months . Loans qualify for return to accrual status once they have demonstrated performance with the restructured terms of the loan agreement for a minimum of six months and the collection of principal and interest under the revised terms is deemed probable. All TDRs are considered to be impaired loans.
FHLB stock and other restricted securities	FHLB stock and other restricted securities: FHLB, FRB and other restricted stock is carried at cost, classified as restricted securities and periodically evaluated for impairment based on the ultimate recoverability of the par value. Both cash and stock dividends are reported as interest income.
Bank-Owned Life Insurance	Bank-Owned Life Insurance : The Company has purchased life insurance policies on certain key employees. The purchase of these life insurance policies allows the Company to use tax-advantaged rates of return. Bank-owned life insurance is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value adjusted for other charges or other amounts due that are probable at settlement.
Premises and Equipment	Premises and Equipment : Land is carried at cost. Premises and equipment are stated at cost less accumulated depreciation. Buildings and related components are generally depreciated using the straight-line method with useful lives ranging from 10 to 30 years. Furniture, fixtures and equipment are generally depreciated using the straight-line method with useful lives ranging from 3 to 7 years. The cost of leasehold improvements is amortized over the shorter of the lease term or useful life using the straight-line method.
Goodwill	Goodwill : Goodwill represents the excess of the cost of businesses acquired over the fair value of the net assets acquired. According to ASC 350-20, "Intangibles- Goodwill and Other," goodwill shall be tested for impairment between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value below its carrying amount. Deterioration in economic market conditions, changes in key personnel, increased estimates of the effects of recent regulatory or legislative changes, or additional regulatory or legislative changes may result in declines in projected business performance beyond management's current expectations. Such declines in business performance could cause the estimated fair value of goodwill to decline, which could result in an impairment charge to earnings in a future period related to goodwill. The Company evaluates goodwill for impairment on an annual basis or on an interim basis if an event occurs or circumstances change that would more likely than not reduce the fair value below its carrying amount, in accordance with ASC 350-20. During 2016, the Company changed its annual goodwill impairment testing date from December 31 to October 1. The Company believes that this new date is preferable as it provides additional time prior to the Company’s year-end to complete the annual goodwill impairment test, especially in the event of future acquisitions and growth. This change does not accelerate, delay, avoid or cause an impairment charge, nor does this change result in adjustments to previously issued financial statements. The Company first assesses 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 as a basis for determining the need to perform the two-step test for goodwill impairment (the qualitative method). If the qualitative method cannot be used or if it determines, based on the qualified method, that the fair value is more likely than not less than the carrying amount, the Company uses the two-step test. Under the two-step test, the Company compares the estimated fair value of a reporting unit with its carrying amount, including goodwill. If the estimated fair value of a reporting unit exceeds its carrying amount, goodwill of the reporting unit is considered not impaired. If the carrying amount of a reporting unit exceeds its estimated fair value, the second step of the goodwill impairment test is performed to measure the amount of impairment loss, if any. Step two of the goodwill impairment test compares the implied estimated fair value of reporting unit goodwill with the carrying amount of that goodwill. If the carrying amount of goodwill for that reporting unit exceeds the implied fair value of that unit's goodwill, an impairment loss is recognized in an amount equal to that excess.
Identifiable Intangibles	Identifiable Intangibles : Intangible assets are acquired assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights or because the asset is capable of being sold or exchanged either on its own or in combination with a related contract, asset, or liability. The Company's intangible assets relate to core deposits and customer relationships. Intangible assets with definite useful lives are amortized on an accelerated basis over their estimated life. Intangible assets, premises and equipment and other long-lived assets are tested for impairment whenever events or changes in circumstances indicate the carrying amount of the assets may not be recoverable from future undiscounted cash flows. If impaired, the assets are recorded at fair value.
Foreclosed Assets	Foreclosed Assets : Assets acquired through loan foreclosure are initially recorded at the lower of the recorded investment in the loan at the time of foreclosure or the fair value less costs to sell, establishing a new cost basis. Any write-down in the carrying value of a property at the time of acquisition is charged-off to the allowance for loan losses. If fair value declines subsequent to foreclosure, a valuation allowance is recorded through expense. Operating costs after acquisition are expensed.
Derivative Financial Instruments	Derivative Financial Instruments : The Company enters into the following derivative financial instruments: interest rate lock commitments, forward mortgage-backed securities trades and interest rate swaps and caps. These financial instruments are not designated as hedging instruments and are used for asset and liability management and commercial customers' financing needs. All derivatives are carried at fair value in either other assets or other liabilities.
Fair Value of Financial Instruments	Fair Value of Financial Instruments : In general, fair values of financial instruments are based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon internally developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments may include amounts to reflect counterparty credit quality and the Company’s creditworthiness, among other things, as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. Fair value measurements and disclosures guidance establishes a three-level fair value hierarchy based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value.
Repurchase/Resell Agreements	Repurchase/Resell Agreements: The Company sells certain securities under agreements to repurchase. The securities sold under these agreements are treated as collateralized borrowings and are recorded at amounts equal to the cash received. The contractual terms of the agreements to repurchase may require the Company to provide additional collateral if the fair value of the securities underlying the borrowings declines during the term of the agreement.
Advertising Expense	Advertising Expense : The Company expenses all advertising costs as they are incurred.
Share-Based Compensation	Share-Based Compensation : The Company has shareholder approved share-based compensation plans that are accounted for under ASC 718, Compensation - Stock Compensation , which requires companies to record compensation cost for share-based payment transactions with employees in return for employment service. Compensation cost is recognized for stock options and restricted stock awards based on the fair value of these awards at the date of grant. A Black-Scholes model is utilized to estimate the fair value of stock options, while the market price of the Company’s common stock at the date of grant is used for restricted stock awards. Compensation cost is recognized over the required service period, generally defined as the vesting period. For awards with time-based vesting, compensation cost is recognized on a straight-line basis over the requisite service period for the entire award. For awards with performance-based vesting conditions, compensation cost is recognized when the achievement of the performance condition is considered probable of achievement. If a performance condition is subsequently determined to be improbable of achievement, compensation cost is reversed.
Retirement Plans	Retirement Plans: Employee 401(k) and profit sharing plan expense is the amount of matching contributions as determined by formula. Deferred compensation and supplemental retirement plan expense allocates the benefits over years of service.
Income Taxes	Income Taxes : Income tax expense is the total of the current year income tax due or refundable and the change in deferred tax assets and liabilities. Deferred tax assets and liabilities are the expected future tax amounts for the temporary differences between carrying amounts and tax bases of assets and liabilities, computed using enacted tax rates. A valuation allowance, if needed, reduces deferred tax assets to the amount expected to be realized. A tax position is recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded. The Company did not have any material uncertain tax positions which would require accrual at December 31, 2017 or 2016 . The Company recognizes interest and/or penalties related to income tax matters in income tax expense and did not have any amounts accrued for interest and penalties for the years ended December 31, 2017 or 2016 . The Company files a consolidated income tax return with its subsidiaries. Federal income tax expense or benefit has been allocated to subsidiaries on a separate return basis.
Earnings per common share	Earnings per common share : The Company calculated earnings per common share in accordance with ASC 260, “Earnings Per Share,” which provides that unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are participating securities and shall be included in the computation of earnings per share pursuant to the two-class method. The Company has determined that its outstanding non-vested stock awards are participating securities. Accordingly, earnings per common share is computed using the two-class method prescribed under ASC 260. Under the two-class method, basic earnings per common share is computed by dividing net earnings allocated to common stock by the weighted-average number of common shares outstanding during the applicable period, excluding outstanding participating securities. Diluted earnings per common share is computed using the weighted-average number of shares determined for the basic earnings per common share computation plus the dilutive effect of stock compensation using the treasury stock method. A reconciliation of the weighted-average shares used in calculating basic earnings per common share and the weighted average common shares used in calculating diluted earnings per common share for the reported periods is provided in Note 3 — Earnings Per Common Share.
Comprehensive Income (Loss)	Comprehensive Income (Loss) : Comprehensive income (loss) consists of net income and other comprehensive income (loss). Other comprehensive income (loss) includes unrealized gains and losses on securities available for sale, net of taxes, which are also recognized as a separate component of equity.
Employee stock ownership plan (ESOP)	Employee stock ownership plan (ESOP) : The Company accounts for its ESOP in accordance with ASC 718-40, "Employee Stock Ownership Plans." Accordingly, since the Company sponsors the ESOP with an employer loan, neither the ESOP’s loan payable nor the Company’s loan receivable are reported in the Company’s consolidated balance sheet. Likewise, the Company does not recognize interest income or interest cost on the loan. Unallocated shares held by the ESOP are recorded as unearned ESOP shares in the consolidated statement of changes in shareholders’ equity. As shares are committed to be released for allocation, the Company recognizes compensation expense equal to the average market price of the shares for the period. Dividends on allocated ESOP shares reduce retained earnings; dividends on unearned ESOP shares reduce principal and accrued interest payable on the ESOP loan.
Dividend Restriction	Dividend Restriction : Banking regulations require maintaining certain capital levels and may limit the dividends paid by the Bank to the Company or by the Company to shareholders.
Loss Contingencies	Loss Contingencies : Loss contingencies, including claims and legal actions arising in the ordinary course of business, are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated. Management does not believe there now are such matters that will have a material effect on the financial statements.
Transfers of Financial Assets	Transfers of Financial Assets : Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (i) the assets have been isolated from the Company, (ii) the transferee has the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (iii) the Company does not maintain effective control over the transferred assets through either (a) an agreement that entitles and obligates the Company to repurchase or redeem them before their maturity or (b) the ability to unilaterally cause the holder to return specific assets.
Operating Segments	Operating Segments: The Company has determined that all of its banking operations comprise one segment under ASC 280, Segment Reporting , since all offer similar products and services, operate with similar processes, and have similar customers. Additionally, the Company has determined that the Bank's title subsidiary does not meet the materiality threshold to require segment disclosure under ASC 280.
Loan Commitments And Related Financial Instruments	Loan Commitments and Related Financial Instruments : Financial instruments include off-balance sheet credit instruments, such as commitments to make loans and commercial letters of credit, issued to meet customer financing needs. The face amount for these items represents the exposure to loss, before considering customer collateral or ability to repay. Such financial instruments are recorded when they are funded.
Reclassifications	Reclassifications : Some items in the prior year financial statements were reclassified to conform to the current presentation.
Adoption of New Accounting Standards	Adoption of New Accounting Standards : In March 2016, the Financial Accounting Standards Board (the "FASB") issued Accounting Standards Update ("ASU") 2016-06, Contingent Put and Call Options in Debt Instruments . This ASU clarifies the requirements for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. An entity performing the assessment under this ASU is required to assess the embedded call (put) options solely in accordance with the four-step decision sequence. The amendments apply to all entities that are issuers of or investors in debt instruments (or hybrid financial instruments that are determined to have a debt host) with embedded call (put) options. For public business entities, this ASU was effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods therein. The adoption of this ASU did not have an impact on the Company's financial statements and disclosures. In March 2016, the FASB issued ASU 2016-07, Simplifying the Transition to the Equity Method of Accounting . This ASU eliminates the requirement for an investor to retrospectively apply the equity method when an investment that it had accounted for by another method qualifies for use of the equity method. This ASU was effective for fiscal years beginning after December 15, 2016, and interim periods therein. The adoption of this ASU did not impact the Company's financial statements. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting . This ASU simplifies several aspects of the accounting for employee share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. For public business entities, this ASU was effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods therein. See Note 13 - Share-based Compensation for information regarding the impact of this ASU on the Company's financial statements. Effect of Newly Issued But Not Yet Effective Accounting Standards In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers . This ASU states that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This ASU affects entities that enter into contracts with customers to transfer goods or services or enter into contracts for the transfer of nonfinancial assets, unless those contracts are within the scope of other standards. In August 2015, the FASB issued ASU 2015-14, "Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date," which deferred the effective date of ASU 2014-09 for public entities to annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Our revenue is comprised of net interest income on financial assets and financial liabilities, which is explicitly excluded from the scope of ASU 2014-09, and non-interest income. We have completed our evaluation of the impact of ASU 2014-09 on components of our non-interest income and have not found any significant changes to our methodology of recognizing revenue. As required by ASU 2014-09, we will adopt the standard in the first quarter of 2018 and, at the time of this filing, we do not anticipate recording a cumulative effect adjustment to opening retained earnings because the adjustment was determined to be insignificant. We will include newly applicable revenue disclosures in our Form 10-Q for the quarter ended March 31, 2018. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurements of Financial Assets and Financial Liabilities . This ASU requires that all equity investments be measured at fair value with changes in the fair value recognized through net income (other than those accounted for under the equity method of accounting or those that result in consolidation of the investee). This ASU also requires that an entity 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. Additionally, this ASU requires that public business entities base their fair value disclosures for financial instruments that are not measured at fair value in the financial statements on the exit price notion. Currently, the Company values these financial instruments using an entry price notion consistent with the current guidance, and will be changing to the exit price notion in the first quarter of 2018 in compliance with this ASU. For public business entities, this ASU is effective for annual periods beginning after December 15, 2017, and interim periods therein. The adoption of this ASU will not have a significant impact on the Company's financial statements and disclosures. In February 2016, the FASB issued ASU 2016-02, Leases . This ASU requires lessees to put most leases on their balance sheets but recognize expenses in the income statement in a manner similar to current accounting treatment. This ASU changes the guidance on sale-leaseback transactions, initial direct costs and lease execution costs, and, for lessors, modifies the classification criteria and the accounting for sales-type and direct financing leases. For public business entities, this ASU is effective for annual periods beginning after December 15, 2018, and interim periods therein. Entities are required to use a modified retrospective approach for leases that exist or are entered into after the beginning of the earliest comparative period in the financial statements. The Company is evaluating the impact of this ASU on its financial statements and disclosures. In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments. This ASU removes the thresholds that companies apply to measure credit losses on financial instruments measured at amortized cost, such as loans, receivables, and held to maturity debt securities. Under current US GAAP, companies generally recognize credit losses when it is probable that the loss has been incurred. This revised guidance will remove all recognition thresholds and will require companies to recognize an allowance for lifetime expected credit losses. Credit losses will be immediately recognized through net income; the amount recognized will be based on the current estimate of contractual cash flows not expected to be collected over the financial asset’s contractual term. ASU 2016-13 also amends the credit loss measurement guidance for available for sale debt securities. For public business entities, this ASU is effective for financial statements issued for fiscal years and for interim periods within those fiscal years beginning after December 15, 2019. The Company is evaluating the impact of this ASU on its financial statements and disclosures. In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments . This ASU is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows, including debt prepayment or debt extinguishment costs, settlement of zero-coupon debt instruments, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, and distributions received from equity method investments. For public business entities, this ASU is effective for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods therein. The adoption of this ASU will not have a significant impact on the Company's financial statements. In October 2016, the FASB issued ASU 2016-16, Intra-Entity Transfers of Assets other than Inventory . This ASU eliminates the exception for all intra-entity sales of assets other than inventory. As a result, a reporting entity would recognize the tax expense from the sale of the asset in the seller’s tax jurisdiction when the transfer occurs, even though the pre-tax effects of that transaction are eliminated in consolidation. Any deferred tax asset that arises in the buyer’s jurisdiction would also be recognized at the time of the transfer. For public business entities, this ASU is effective for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods therein. The adoption of this ASU is not expected to have a significant impact on the Company's financial statements. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment . This ASU simplifies the accounting for goodwill impairment for all entities by requiring impairment charges to be based on the first step in today's two-step impairment test. Under the new guidance, if a reporting unit’s carrying amount exceeds its fair value, an entity will record an impairment charge based on that difference. The impairment charge will be limited to the amount of goodwill allocated to that reporting unit. The standard eliminates today’s requirement to calculate a goodwill impairment charge using Step 2, which requires an entity to calculate any impairment charge by comparing the implied fair value of goodwill with its carrying amount. For public business entities, this ASU is effective for annual periods beginning after December 15, 2019, and interim periods therein. The adoption of this ASU is not expected to have a significant impact on the Company's financial statements and disclosures. In March 2017, the FASB issued ASU 2017-08, Premium Amortization on Purchased Callable Debt Securities . This ASU requires certain premiums on callable debt securities to be amortized to the earliest call date. The amortization period for callable debt securities purchased at a discount will not be impacted. Under current GAAP, premiums on callable debt securities are generally amortized over the contractual life of the security. For public business entities, this ASU is effective for fiscal years beginning after December 15, 2018, and interim periods therein. The adoption of this ASU is not expected to have a significant impact on the Company's financial statements and disclosures. In August 2017, the FASB issued ASU 2017-12, Targeted Improvements to Accounting for Hedging Activities. This ASU amends the hedge accounting model to enable entities to better portray their risk management activities in their financial statements, by expanding an entity's ability to hedge nonfinancial and financial risk components and reduce complexity in fair value hedges of interest rate risk. This ASU eliminates the requirement to separately measure and report hedge ineffectiveness and generally requires the entire change in the fair value of a hedging instrument to be presented in the same income statement line as the hedged item. Additionally, this ASU also eases certain documentation and assessment requirements and modifies the accounting for components excluded from the assessment of hedge effectiveness. For public business entities, this ASU is effective for financial statements issued for fiscal years and for interim periods within those fiscal years beginning after December 15, 2018. The Company is evaluating the impact of this ASU on its financial statements and disclosures.

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Reconciliation of Numerator and Denominator of Basic and Diluted Earnings per Common Share	A reconciliation of the numerator and denominator of the basic and diluted earnings per common share computation for the years ended December 31, 2017 , 2016 and 2015 is as follows: Years Ended December 31, 2017 2016 2015 Basic earnings per share: Numerator: Net income $ 89,494 $ 97,821 $ 70,916 Distributed and undistributed earnings to participating securities (318 ) (497 ) (534 ) Income available to common shareholders $ 89,176 $ 97,324 $ 70,382 Denominator: Weighted average common shares outstanding 47,998,439 47,721,179 47,659,389 Less: Average unallocated ESOP shares (1,220,516 ) (1,301,356 ) (1,464,324 ) Average unvested restricted stock awards (166,143 ) (235,749 ) (347,781 ) Average shares for basic earnings per share 46,611,780 46,184,074 45,847,284 Basic earnings per common share $ 1.91 $ 2.11 $ 1.54 Diluted earnings per share: Numerator: Income available to common shareholders $ 89,176 $ 97,324 $ 70,382 Denominator: Average shares for basic earnings per share 46,611,780 46,184,074 45,847,284 Dilutive effect of share-based compensation plan 526,738 300,893 278,163 Average shares for diluted earnings per share 47,138,518 46,484,967 46,125,447 Diluted earnings per common share $ 1.89 $ 2.09 $ 1.53 Share awards excluded in the computation of diluted earnings per share because the exercise price was greater than the common stock average market price and were therefore anti-dilutive 623,666 1,384,784 1,012,771

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Fair Value of Available-for-Sale Securities and Related Gross Unrealized Gains and Losses	The amortized cost, related gross unrealized gains and losses recognized in accumulated other comprehensive income (loss), and the fair value of securities available for sale ("AFS") were as follows: December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Agency residential mortgage-backed securities 1 $ 191,216 $ 419 $ 2,169 $ 189,466 Agency commercial mortgage-backed securities 1 9,360 — 125 9,235 Agency residential collateralized mortgage obligations 1 187,637 4 3,425 184,216 US government and agency securities 1,590 81 — 1,671 Municipal bonds 35,196 241 308 35,129 Total securities $ 424,999 $ 745 $ 6,027 $ 419,717 December 31, 2016 Agency residential mortgage-backed securities 1 $ 220,744 $ 635 $ 2,828 $ 218,551 Agency commercial mortgage-backed securities 1 9,422 — 75 9,347 Agency residential collateralized mortgage obligations 1 87,959 22 1,452 86,529 US government and agency securities 2,150 101 — 2,251 Municipal bonds 38,417 47 627 37,837 Total securities $ 358,692 $ 805 $ 4,982 $ 354,515 1 Mortgage-backed securities and collateralized mortgage obligations are issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises.
Carrying Amount, Unrecognized Gains and Losses, and Fair Value of Securities Held to Maturity	The amortized cost (carrying amount), unrealized gains and losses, and fair value of securities held to maturity ("HTM") were as follows: December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Agency residential mortgage-backed securities 1 $ 57,334 $ 616 $ 646 $ 57,304 Agency commercial mortgage-backed securities 1 27,435 589 98 27,926 Agency residential collateralized mortgage obligations 1 27,112 265 99 27,278 Municipal bonds 61,628 1,079 289 62,418 Total securities $ 173,509 $ 2,549 $ 1,132 $ 174,926 December 31, 2016 Agency residential mortgage-backed securities 1 $ 74,881 $ 1,147 $ 817 $ 75,211 Agency commercial mortgage-backed securities 1 28,023 836 166 28,693 Agency residential collateralized mortgage obligations 1 40,707 697 33 41,371 Municipal bonds 66,776 1,635 705 67,706 Total securities $ 210,387 $ 4,315 $ 1,721 $ 212,981 1 Mortgage-backed securities and collateralized mortgage obligations are issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises.
Carrying Amount and Fair Value of Held to Maturity Debt Securities and Fair Value of Available-for-Sale Debt Securities	The amortized cost (carrying amount) and fair value of held to maturity debt securities and the fair value of available for sale debt securities at December 31, 2017 by contractual maturity are set forth below in the table below. Securities with contractual payments not due at a single maturity date, including mortgage backed securities and collateralized mortgage obligations, are shown separately. HTM AFS Amortized Cost Fair Value Fair Value Due in one year or less $ 1,365 $ 1,373 $ 1,526 Due after one to five years 10,699 10,959 12,726 Due after five to ten years 44,059 44,628 16,731 Due after ten years 5,505 5,458 5,817 Agency residential mortgage-backed securities 57,334 57,304 189,466 Agency commercial mortgage-backed securities 27,435 27,926 9,235 Agency residential collateralized mortgage obligations 27,112 27,278 184,216 Total $ 173,509 $ 174,926 $ 419,717
Summarized Sales Activity	Sales activity of securities for the years ended December 31, 2017 , 2016 and 2015 was as follows. All securities sold were classified as available for sale. December 31, 2017 2016 2015 Proceeds $ — $ 7,700 $ 36,984 Gross gains — 72 278 Gross losses — 7 50 Tax expense of securities gains/losses reclassified from accumulated other comprehensive income — 23 80
Securities with Unrealized Losses Aggregated by Investment and Length of Time that Individual Securities have been in Continuous Unrealized Loss Position Category	Securities with unrealized losses at December 31, 2017 and 2016 , aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, were as follows: AFS Less than 12 Months 12 Months or More Total December 31, 2017 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Agency residential mortgage-backed securities 1 $ 59,545 $ 412 $ 100,214 $ 1,757 $ 159,759 $ 2,169 Agency commercial mortgage-backed securities 1 9,235 125 — — 9,235 125 Agency residential collateralized mortgage obligations 1 128,869 1,860 49,171 1,565 178,040 3,425 Municipal bonds 10,114 72 6,583 236 16,697 308 Total temporarily impaired $ 207,763 $ 2,469 $ 155,968 $ 3,558 $ 363,731 $ 6,027 December 31, 2016 Agency residential mortgage-backed securities 1 $ 167,503 $ 2,770 $ 7,516 $ 58 $ 175,019 $ 2,828 Agency commercial mortgage-backed securities 1 9,347 75 — — 9,347 75 Agency residential collateralized mortgage obligations 1 72,822 1,420 2,649 32 75,471 1,452 Municipal bonds 26,911 512 3,412 115 30,323 627 Total temporarily impaired $ 276,583 $ 4,777 $ 13,577 $ 205 $ 290,160 $ 4,982 HTM Less than 12 Months 12 Months or More Total December 31, 2017 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Agency residential mortgage-backed securities 1 $ 20,397 $ 206 $ 16,909 $ 440 $ 37,306 $ 646 Agency commercial mortgage-backed securities 1 3,685 26 3,484 72 7,169 98 Agency residential collateralized mortgage obligations 1 8,008 64 2,267 35 10,275 99 Municipal bonds 9,313 80 10,486 209 19,799 289 Total temporarily impaired $ 41,403 $ 376 $ 33,146 $ 756 $ 74,549 $ 1,132 December 31, 2016 Agency residential mortgage-backed securities 1 $ 41,375 $ 817 $ — $ — $ 41,375 $ 817 Agency commercial mortgage-backed securities 1 7,273 166 — — 7,273 166 Agency residential collateralized mortgage obligations 1 6,322 11 1,451 22 7,773 33 Municipal bonds 19,362 658 1,045 47 20,407 705 Total temporarily impaired $ 74,332 $ 1,652 $ 2,496 $ 69 $ 76,828 $ 1,721 1 Mortgage-backed securities and collateralized mortgage obligations are issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises.

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Loans	Loans consist of the following: December 31, 2017 December 31, 2016 Loans held for sale, at fair value $ 16,707 $ 21,279 Loans held for investment: Commercial real estate $ 3,019,339 $ 2,670,455 Commercial and industrial 2,093,307 1,971,160 Construction and land 277,864 294,894 Consumer real estate 1,213,434 1,074,923 Other consumer 45,506 53,991 Gross loans held for investment, excluding Warehouse Purchase Program 6,649,450 6,065,423 Net of: Deferred costs (fees) and discounts, net 6,380 (2,251 ) Allowance for loan losses (71,301 ) (64,576 ) Net loans held for investment, excluding Warehouse Purchase Program 6,584,529 5,998,596 Warehouse Purchase Program 1,154,588 1,055,341 Total loans held for investment $ 7,739,117 $ 7,053,937
Allowances for Loan Losses and Off-Balance Sheet Credit Losses	Activity in the allowance for loan losses for the years ended December 31, 2017 , 2016 and 2015 , segregated by portfolio segment and evaluation for impairment, is set forth below. The below activity does not include Warehouse Purchase Program loans, which are collectively evaluated for impairment and are purchased under several contractual requirements, providing safeguards to the Company. To date, the Company has not experienced a loss on its Warehouse Purchase Program loans and no allowance for loan losses has been allocated to them. At December 31, 2017 , 2016 and 2015 , the allowance for loan impairment related to purchased credit impaired ("PCI") loans totaled $269 , $180 , and $150 , respectively. For the year ended December 31, 2017 Commercial Real Estate Commercial and Industrial Construction and Land Consumer Real Estate Other Consumer Total Allowance for loan losses: Beginning balance $ 18,303 $ 35,464 $ 5,075 $ 4,484 $ 1,250 $ 64,576 Charge-offs (16 ) (32,846 ) (418 ) (96 ) (1,366 ) (34,742 ) Recoveries 205 405 75 42 640 1,367 Provision expense (benefit) 3,095 35,982 (88 ) 408 703 40,100 Ending balance $ 21,587 $ 39,005 $ 4,644 $ 4,838 $ 1,227 $ 71,301 Allowance ending balance: Individually evaluated for impairment $ — $ 10,527 $ — $ 230 $ 34 $ 10,791 Collectively evaluated for impairment 21,587 28,478 4,644 4,608 1,193 60,510 Loans: Individually evaluated for impairment 4,134 84,005 — 2,992 35 91,166 Collectively evaluated for impairment 3,012,892 2,009,126 277,864 1,209,550 45,288 6,554,720 PCI loans 2,313 176 — 892 183 3,564 Ending balance $ 3,019,339 $ 2,093,307 $ 277,864 $ 1,213,434 $ 45,506 $ 6,649,450 For the year ended December 31, 2016 Commercial Real Estate Commercial and Industrial Construction and Land Consumer Real Estate Other Consumer Total Allowance for loan losses: Beginning balance $ 14,123 $ 24,975 $ 3,013 $ 3,992 $ 990 $ 47,093 Charge-offs (79 ) (7,746 ) — (107 ) (927 ) (8,859 ) Recoveries 21 472 — 109 340 942 Provision expense 4,238 17,763 2,062 490 847 25,400 Ending balance $ 18,303 $ 35,464 $ 5,075 $ 4,484 $ 1,250 $ 64,576 Allowance ending balance: Individually evaluated for impairment $ 300 $ 4,521 $ — $ 138 $ 52 $ 5,011 Collectively evaluated for impairment 18,003 30,943 5,075 4,346 1,198 59,565 Loans: Individually evaluated for impairment 5,195 86,664 11,385 3,300 75 106,619 Collectively evaluated for impairment 2,659,644 1,884,263 283,509 1,070,732 53,683 5,951,831 PCI loans 5,616 233 — 891 233 6,973 Ending balance $ 2,670,455 $ 1,971,160 $ 294,894 $ 1,074,923 $ 53,991 $ 6,065,423 For the year ended December 31, 2015 Commercial Real Estate Commercial and Industrial Construction and Land Consumer Real Estate Other Consumer Total Allowance for loan losses: Beginning balance $ 11,830 $ 9,068 $ 174 $ 4,069 $ 408 $ 25,549 Charge-offs (167 ) (3,129 ) — (321 ) (1,090 ) (4,707 ) Recoveries 29 246 — 85 426 786 Provision expense 2,431 18,790 2,839 159 1,246 25,465 Ending balance $ 14,123 $ 24,975 $ 3,013 $ 3,992 $ 990 $ 47,093 Allowance ending balance: Individually evaluated for impairment $ 366 $ 1,470 $ — $ 81 $ 61 $ 1,978 Collectively evaluated for impairment 13,757 23,505 3,013 3,911 929 45,115 Loans: Individually evaluated for impairment 11,580 16,906 33 4,767 120 33,406 Collectively evaluated for impairment 2,155,351 1,595,548 269,675 931,140 69,433 5,021,147 PCI loans 10,612 215 — 850 277 11,954 Ending balance $ 2,177,543 $ 1,612,669 $ 269,708 $ 936,757 $ 69,830 $ 5,066,507 Changes in the allowance for off-balance sheet credit losses on lending-related commitments and guarantees on credit card debt, included in "accrued expenses and other liabilities" on the consolidated balance sheets, are summarized in the following table. Please see Note 17 - Commitments and Contingent Liabilities for more information. Years Ended December 31, 2017 2016 Balance at beginning of period $ 1,573 $ 73 Charge-offs on lending-related commitments — — Provision (recovery) for credit losses on lending-related commitments (644 ) 1,500 Balance at end of period $ 929 $ 1,573
Impaired Loans	Impaired loans at December 31, 2017 and 2016 , were as follows 1 : December 31, 2017 Unpaid Contractual Principal Balance Recorded Investment With No Allowance Recorded Investment With Allowance Total Recorded Investment Related Allowance Commercial real estate $ 4,411 $ 4,134 $ — $ 4,134 $ — Commercial and industrial 89,713 48,463 35,542 84,005 10,502 Consumer real estate 3,545 2,985 7 2,992 7 Other consumer 71 16 19 35 13 Total $ 97,740 $ 55,598 $ 35,568 $ 91,166 $ 10,522 December 31, 2016 Commercial real estate $ 5,388 $ 4,429 $ 766 $ 5,195 $ 272 Commercial and industrial 87,756 73,377 13,287 86,664 4,519 Construction and land 11,384 11,385 — 11,385 — Consumer real estate 3,766 3,290 10 3,300 10 Other consumer 107 33 42 75 30 Total $ 108,401 $ 92,514 $ 14,105 $ 106,619 $ 4,831 1 No Warehouse Purchase Program loans were impaired at December 31, 2017 or 2016 . Loans reported do not include PCI loans. Income on impaired loans at December 31, 2017 , 2016 and 2015 , was as follows 1 December 31, 2017 December 31, 2016 December 31, 2015 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial real estate $ 4,421 $ 8 $ 5,240 $ 9 $ 8,178 $ 24 Commercial and industrial 83,508 — 28,634 1 19,595 8 Construction and land 2,273 — 901 — 84 — Consumer real estate 2,786 14 4,831 14 5,269 7 Other consumer 264 4 95 4 202 2 Total $ 93,252 $ 26 $ 39,701 $ 28 $ 33,328 $ 41 1 Loans reported do not include PCI loans The carrying amount of PCI loans included in the consolidated balance sheets and the related outstanding balances at December 31, 2017 and 2016 are set forth in the table below. The outstanding balance represents the total amount owed, including accrued but unpaid interest, and any amounts previously charged off. December 31, 2017 2016 Carrying amount 1 $ 3,295 $ 6,793 Outstanding balance 3,992 7,597 1 The carrying amounts are reported net of allowance for loan losses of $269 and $180 as of December 31, 2017 and 2016 . Changes in the accretable yield for PCI loans for the years ended December 31, 2017 and 2016 , are as follows: December 31, 2017 2016 Balance at beginning of period $ 2,515 $ 3,356 Reclassifications from nonaccretable 602 429 Disposals (187 ) (359 ) Accretion (651 ) (911 ) Balance at end of period $ 2,279 $ 2,515
Non-Performing (Nonaccrual) Loans	Non-performing loans were as follows: December 31, 2017 2016 Commercial real estate $ 4,134 $ 5,195 Commercial and industrial 84,003 86,664 Construction and land — 11,385 Consumer real estate 6,190 7,987 Other consumer 76 158 Total $ 94,403 $ 111,389
Outstanding and Recorded Balances of Loans Modified as TDRs	The outstanding balances of TDRs are shown below: December 31, 2017 2016 Nonaccrual TDRs (1) $ 17,294 $ 11,701 Performing TDRs (2) 768 454 Total $ 18,062 $ 12,155 Outstanding commitments to lend additional funds to borrowers with TDR loans — — 1 Nonaccrual TDR loans are included in the nonaccrual loan totals. 2 Performing TDR loans are loans that have been performing under the restructured terms for at least six months and the Company is accruing interest on these loans. The following table provides the recorded balances of loans modified as a TDR during the years ended December 31, 2017 , 2016 and 2015 . December 31, 2017 Principal Deferrals Combination of Rate Reduction & Principal Deferral Other Total Commercial and industrial $ 38 $ 131 $ 14,063 (1) $ 14,232 Total $ 38 $ 131 $ 14,063 $ 14,232 December 31, 2016 Commercial and industrial $ 685 $ — $ 7,090 (1) $ 7,775 Consumer real estate — 79 — 79 Other consumer 1 — — 1 Total $ 686 $ 79 $ 7,090 $ 7,855 December 31, 2015 Commercial real estate $ 100 $ — $ — $ 100 Commercial and industrial — — 191 191 Consumer real estate 209 (2) 60 36 305 Other consumer 1 — 3 4 Total $ 310 $ 60 $ 230 $ 600 1 Reserve-based energy relationships where the primary modification consisted of suspension of required borrowing base payments. 2 Principal deferrals include Chapter 7 bankruptcy loans for which the court has discharged the borrower's obligation and the borrower has not reaffirmed the debt. Such loans are placed on non-accrual status. Loans modified as a TDR during the years ended December 31, 2017 , 2016 and 2015 , which experienced a subsequent payment default during the periods, are shown below. A payment default is defined as a loan that was 90 days or more past due. Years Ended December 31, 2017 2016 2015 Consumer real estate $ — $ 31 $ 178
Analysis of Age of Recorded Investment in Loans	Below is an analysis of the age of recorded investment in loans that were past due at December 31, 2017 and 2016 . No Warehouse Purchase Program loans were delinquent at December 31, 2017 or 2016 and therefore are not included in the following table. December 31, 2017 30-59 Days Past Due 60-89 Days Past Due 90 Days and Greater Past Due Total Loans Past Due Current Loans 1 Total Loans Commercial real estate $ 9,414 $ — $ 250 $ 9,664 $ 3,009,675 $ 3,019,339 Commercial and industrial 918 284 7,350 8,552 2,084,755 2,093,307 Construction and land 9,354 — — 9,354 268,510 277,864 Consumer real estate 16,436 2,928 1,367 20,731 1,192,703 1,213,434 Other consumer 891 34 2 927 44,579 45,506 Total $ 37,013 $ 3,246 $ 8,969 $ 49,228 $ 6,600,222 $ 6,649,450 December 31, 2016 Commercial real estate $ 1,829 $ 72 $ 766 $ 2,667 $ 2,667,788 $ 2,670,455 Commercial and industrial 20,910 495 46 21,451 1,949,709 1,971,160 Construction and land 19,517 283 — 19,800 275,094 294,894 Consumer real estate 10,487 1,916 1,199 13,602 1,061,321 1,074,923 Other consumer 1,523 31 6 1,560 52,431 53,991 Total $ 54,266 $ 2,797 $ 2,017 $ 59,080 $ 6,006,343 $ 6,065,423 1 Includes acquired PCI loans with a total carrying value of $3,338 and $6,729 at December 31, 2017 and 2016 , respectively.
Real Estate and Commercial and Industrial Credit Risk Profile by Internally Assigned Grade	The recorded investment in loans by credit quality indicators at December 31, 2017 and 2016 , was as follows. Real Estate and Commercial and Industrial Credit Exposure Credit Risk Profile by Internally Assigned Grade December 31, 2017 Commercial Real Estate Commercial and Industrial Construction and Land Consumer Real Estate Grade: 1 Pass $ 2,980,656 $ 1,953,496 $ 277,864 $ 1,203,236 Special Mention 30,656 43,161 — 1,408 Substandard 8,027 96,546 — 7,762 Doubtful — 104 — 1,028 Total $ 3,019,339 $ 2,093,307 $ 277,864 $ 1,213,434 December 31, 2016 Grade: 1 Pass $ 2,648,842 $ 1,712,171 $ 283,423 $ 1,062,549 Special Mention 7,972 155,110 — 2,083 Substandard 12,875 103,815 11,471 8,252 Doubtful 766 64 — 2,039 Total $ 2,670,455 $ 1,971,160 $ 294,894 $ 1,074,923 1 PCI loans are included in the substandard or doubtful categories for December 31, 2017 and 2016 , respectively. These categories are generally consistent with the "substandard" and "doubtful" categories as defined by regulatory authorities.
Consumer Credit Exposure Credit Risk Profile Based on Payment Activity	Credit Risk Profile Based on Payment Activity December 31, 2017 December 31, 2016 Performing $ 45,430 $ 53,833 Non-performing 76 158 Total $ 45,506 $ 53,991

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis	Assets and liabilities measured at fair value on a recurring basis are summarized below. Fair Value Measurements Using Level 2 December 31, 2017 December 31, 2016 Assets: Agency residential mortgage-backed securities $ 189,466 $ 218,551 Agency commercial mortgage-backed securities 9,235 9,347 Agency residential collateralized mortgage obligations 184,216 86,529 US government and agency securities 1,671 2,251 Municipal bonds 35,129 37,837 Total securities available for sale $ 419,717 $ 354,515 Loans held for sale 1 $ 16,707 $ 21,279 Derivative financial instruments: Interest rate lock commitments 358 379 Forward mortgage-backed securities trades 7 36 Loan customer counterparty — — Financial institution counterparty 1,735 1,369 Liabilities: Derivative financial instruments: Interest rate lock commitments — — Forward mortgage-backed securities trades 18 80 Loan customer counterparty 1,735 1,369 Financial institution counterparty — — 1 At December 31, 2017 , loans held for sale had an aggregate outstanding principal balance of $16,242 . There were no mortgage loans held for sale that were 90 days or greater past due or on non-accrual at December 31, 2017 .
Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis	Assets measured at fair value on a non-recurring basis are summarized below. There were no liabilities measured at fair value on a non-recurring basis as of December 31, 2017 or 2016 . Fair Value Measurements Using Level 3 December 31, 2017 December 31, 2016 Assets: Impaired loans $ 25,046 $ 9,274 Foreclosed assets: Commercial real estate 6,694 10,638 Construction and land 859 194 Consumer real estate 192 — Other 687 6
Fair Value of Financial Instruments Not Recorded at Fair Value	The carrying amount and fair value information of financial instruments not recorded at fair value in their entirety on a recurring basis on the Company's consolidated balance sheets at December 31, 2017 and 2016 , were as follows: Fair Value December 31, 2017 Carrying Amount Level 1 Level 2 Level 3 Financial assets Cash and cash equivalents $ 293,456 $ 293,456 $ — $ — Securities held to maturity 173,509 — 174,926 — Loans held for investment, net 6,584,529 — — 6,651,207 Loans held for investment - Warehouse Purchase Program 1,154,588 — — 1,171,354 FHLB and other restricted securities, at cost 64,790 — 64,790 — Accrued interest receivable 24,596 24,596 — — Financial liabilities Deposits $ 6,767,683 $ — $ — $ 6,326,572 FHLB advances 1,043,163 — — 1,043,416 Repurchase agreements 84,676 — — 81,041 Subordinated debt 134,522 — — 141,972 Accrued interest payable 2,729 2,729 — — December 31, 2016 Financial assets Cash and cash equivalents $ 289,212 $ 289,212 $ — $ — Securities held to maturity 210,387 — 212,981 — Loans held for investment, net 5,998,596 — — 6,080,165 Loans held for investment - Warehouse Purchase Program 1,055,341 — — 1,055,219 FHLB and other restricted securities, at cost 43,266 — 43,266 — Accrued interest receivable 20,347 20,347 — — Financial liabilities Deposits $ 6,365,476 $ — $ — $ 5,989,933 FHLB advances 833,682 — — 830,930 Repurchase agreement 86,691 — — 84,265 Subordinated debt 134,032 — — 121,743 Accrued interest payable 2,111 2,111 — —

Derivative Financial Instrume34

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts of Outstanding Derivative Positions	The commercial loan customer counterparty weighted average received and paid interest rates for interest rate swaps outstanding at December 31, 2017 and 2016 are presented in the following table. Weighted-Average Interest Rate December 31, 2017 December 31, 2016 Received Paid Received Paid Loan customer counterparty 2.52 % 2.54 % 3.12 % 2.36 % Income (loss) for the years ended December 31, 2017 , 2016 and 2015 was as follows: Derivatives not designated as hedging instruments Years Ended December 31, 2017 2016 2015 IRLC's $ (21 ) $ (43 ) $ 8 Forward mortgage-backed securities trades (479 ) 13 (195 ) The following table provides the outstanding notional balances and fair values of outstanding derivative positions at December 31, 2017 and 2016 . December 31, 2017 December 31, 2016 Outstanding Notional Balance Asset Derivative Fair Value Liability Derivative Fair Value Outstanding Notional Balance Asset Derivative Fair Value Liability Derivative Fair Value IRLCs $ 10,337 $ 358 $ — $ 10,952 $ 379 $ — Forward mortgage-backed securities trades 19,788 7 18 18,613 36 80 Commercial loan interest rate swaps and caps: Loan customer counterparty 114,594 — 1,735 112,294 — 1,369 Financial institution counterparty 114,594 1,735 — 112,294 1,369 —

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and equipment were as follows: December 31, 2017 2016 Land $ 22,140 $ 23,636 Buildings 57,079 59,298 Furniture, fixtures and equipment 20,218 19,561 Leasehold improvements 10,055 7,674 109,492 110,169 Less: accumulated depreciation (39,799 ) (35,943 ) Total $ 69,693 $ 74,226
Rent Commitments	Rent commitments, before considering applicable renewal options, as of December 31, 2017 , were as follows: Balance 2018 $ 5,725 2019 5,069 2020 4,696 2021 4,443 2022 3,735 Thereafter 16,303 Total $ 39,971

Goodwill and Core Deposit Int36

Goodwill and Core Deposit Intangibles (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Changes In Carrying Amount of Company's Goodwill and Core Deposit Intangibles (Cdi)	Changes in the carrying amount of the Company's goodwill and core deposit intangibles (“CDI”) for years ended December 31, 2017 and 2016 , were as follows: Goodwill Core Deposit Intangibles Balance as of December 31, 2015 $ 180,776 $ 1,030 Disposition of insurance subsidiary goodwill upon the sale of subsidiary operations (2,217 ) — Amortization of core deposit intangible — (365 ) Balance as of December 31, 2016 178,559 665 Amortization of core deposit intangible — (263 ) Balance as of December 31, 2017 $ 178,559 $ 402
Estimated Aggregate Future Amortization Expense for Intangible Assets Remaining	The estimated aggregate future amortization expense for CDI remaining as of December 31, 2017 is as follows: Balance 2018 $ 156 2019 101 2020 73 2021 48 2022 24 Thereafter —

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Scheduled Maturity of Time Deposits	At December 31, 2017 , scheduled maturities of time deposits for the next five years with the weighted average rate at the end of the period were as follows: Balance Weighted Average Rate 2018 $ 860,102 1.16 % 2019 383,687 1.57 2020 41,093 1.47 2021 59,074 1.59 2022 and thereafter 23,434 1.57 Total $ 1,367,390 1.31 %
Interest Expense on Deposits	Interest expense on deposits is summarized as follows: Years Ended December 31, 2017 2016 2015 Interest-bearing demand $ 5,475 $ 3,974 $ 3,297 Savings and money market 16,845 7,288 3,644 Time 14,374 9,772 6,186 Total $ 36,694 $ 21,034 $ 13,127

Borrowed Funds (Tables)

Borrowed Funds (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Summary of Borrowed Funds	Borrowed funds are summarized as follows: December 31, 2017 2016 Amount Rate 1 Amount Rate 1 Federal Home Loan Bank advances $ 1,043,163 1.51 % $ 833,682 0.71 % Repurchase Agreements Credit Suisse structured repurchase agreement 25,000 3.02 25,000 3.02 Overnight repurchase agreements with depositors 59,676 1.18 61,691 0.15 Subordinated Debt Fixed to floating rate note maturing on December 1, 2025 125,000 5.50 125,000 5.58 Junior subordinated debentures 15,464 3.29 15,464 2.66 1 Rate at period-end, with the exception of the fixed to floating rate subordinated debt note, which is a weighted average rate calculated using period-end rates.
Debt Pay Down Schedule	At December 31, 2017 , borrowed funds, reported gross of purchase accounting fair value discounts, prepayment penalties and debt issuance costs, were structured to contractually pay down as follows: FHLB Advances Repurchase Agreements Subordinated Debt Total 2018 $ 1,037,754 $ 84,676 $ — $ 1,122,430 2019 2,313 — — 2,313 2020 932 — — 932 2021 856 — — 856 2022 695 — — 695 Thereafter 613 — 140,464 141,077 $ 1,043,163 $ 84,676 $ 140,464 $ 1,268,303

Share-based Compensation (Table

Share-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs	Compensation cost charged to income for share-based compensation, which is reported in non-interest expense as salaries and employee benefits expense, is presented below: Years ended December 31, 2017 2016 2015 Restricted stock $ 3,581 $ 3,477 $ 3,459 Stock options 3,881 2,537 2,018 Income tax benefit 2,612 2,105 1,917
Nonvested Shares for the Company's Stock Plans	A summary of activity in the restricted stock portion of the Company's Plans for 2017 , 2016 and 2015 is presented below: Time-Vested Shares Performance-Based Shares Shares Weighted- Average Grant Date Fair Value per Share 1 Shares Weighted- Average Grant Date Fair Value per Share 2 Non-vested at January 1, 2015 297,603 $ 20.45 82,400 $ 23.89 Granted 80,000 21.23 — — Vested (131,142 ) 19.98 (20,600 ) 23.89 Non-vested at December 31, 2015 246,461 20.98 61,800 25.02 Granted 55,180 29.29 40,200 29.29 Vested (101,465 ) 20.70 (20,600 ) 25.02 Non-vested at December 31, 2016 200,176 23.79 81,400 43.06 Granted 19,208 38.92 12,208 39.90 Vested (90,796 ) 21.67 (20,600 ) 41.32 Non-vested at December 31, 2017 128,588 $ 27.27 73,008 $ 42.21 1 For restricted stock awards with time-based vesting conditions, the grant date fair value is based upon the closing stock price as quoted on the Nasdaq Stock Market on the grant date. 2 For restricted stock awards with performance-based vesting conditions, the value of the award is based upon the closing stock price as quoted on the Nasdaq Stock Market on the date of vesting. Until the final value is determined on the vesting date, the Company estimates the fair value based upon the closing stock price as quoted on the Nasdaq Stock Market near the last business day of each month.
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The fair value of options granted was determined using the following weighted-average assumptions as of grant date: 2017 2016 2015 Risk-free interest rate 2.18 % 1.37 % 1.80 % Expected term of stock options (years) 6.2 6.3 6.2 Expected stock price volatility 31.85 % 32.07 % 31.14 % Expected dividends 1.61 % 1.93 % 1.95 %
Summary of Activity under Stock Option Portion of Equity Incentive Plan	A summary of activity in the stock option portion of the Company's Plans as of the years ended December 31, 2017 , 2016 and 2015 is presented below: Options Shares Weighted- Average Exercise Price per Share Weighted- Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at January 1, 2015 1,370,873 $ 20.27 8.0 $ 5,679 Granted 633,000 25.66 Exercised (58,855 ) 16.12 Forfeited (79,268 ) 20.89 Outstanding at December 31, 2015 1,865,750 22.21 7.9 6,401 Granted 392,838 29.15 Exercised (175,192 ) 19.08 Forfeited (75,316 ) 25.57 Outstanding at December 31, 2016 2,008,080 23.71 9.5 38,850 Granted 513,375 37.15 Exercised (221,984 ) 21.23 Forfeited (92,228 ) 28.80 Outstanding at December 31, 2017 2,207,243 $ 26.88 10.1 $ 33,848 Fully vested and expected to vest 2,191,740 $ 26.82 10.1 $ 33,725 Exercisable at December 31, 2017 966,527 $ 22.11 7.5 $ 19,425

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Tax Expense	Income tax expense for 2017 , 2016 and 2015 , was as follows: 2017 2016 2015 Current expense $ 56,341 $ 59,900 $ 38,648 Deferred expense (4,115 ) (6,798 ) (692 ) Impact of Tax Cuts and Jobs Act - net future deductions 12,752 — — Impact of Tax Cuts and Jobs Act - unrealized loss on AFS securities 741 — — Total income tax expense $ 65,719 $ 53,102 $ 37,956
Deferred Tax Assets and Liabilities	At December 31, 2017 and 2016 , deferred tax assets and liabilities were due to the following: December 31, 2017 2016 Deferred tax assets: Allowance for loan losses $ 15,168 $ 22,602 Deferred compensation arrangements 762 1,261 Self-funded health insurance 251 241 Non-accrual interest 503 966 Restricted stock and stock options 2,577 3,132 Accrued expenses 623 1,255 Fair value mark on purchased loans 965 2,348 Net unrealized loss on securities available for sale 1,111 1,465 Other 1,909 2,121 23,869 35,391 Deferred tax liabilities: Depreciation (270 ) (336 ) Partnerships — CRA-purposed private equity funds (941 ) (1,697 ) Fair value mark on subordinated debt (743 ) (1,303 ) Other (1,675 ) (2,824 ) (3,629 ) (6,160 ) Net deferred tax asset $ 20,240 $ 29,231
Reconciliation of Effective Income Tax Rate	Effective tax rates differ from the federal statutory rate of 35% in 2017 , 2016 and 2015 , applied to income before income taxes due to the following: At and for the Year Ended December 31, 2017 2016 2015 Federal statutory rate times financial statement income $ 54,325 $ 52,823 $ 38,105 Effect of: State taxes, net of federal benefit 239 267 37 Bank-owned life insurance income (423 ) (436 ) (419 ) Municipal interest income (978 ) (1,041 ) (1,025 ) ESOP shares released 541 757 1,207 Restricted stock and stock options (1,578 ) — — Sale of LegacyTexas Insurance Services, Inc. — 640 — DTA write-down due to the Tax Cuts and Jobs Act 13,493 — — Other 100 92 51 Total income tax expense $ 65,719 $ 53,102 $ 37,956 Effective Tax Rate before deferred tax write-down 33.65 % 35.18 % 34.86 % Effective Tax Rate 42.34 % 35.18 % 34.86 %

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	Loans to executive officers, directors, and their affiliates during 2017 were as follows: Balance Beginning balance $ 15,337 New loans — Effect of changes in composition of related parties — Repayments (933 ) Ending balance $ 14,404

Regulatory Capital Matters (Tab

Regulatory Capital Matters (Tables)	12 Months Ended
	Dec. 31, 2017
Regulatory Capital Requirements [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	Actual Required for Capital Adequacy Purposes To Be Well-Capitalized Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017 Total risk-based capital Company $ 991,713 11.87 % $ 668,142 8.00 % $ 835,178 10.00 % Bank 939,655 11.25 668,096 8.00 835,120 10.00 Tier 1 risk-based capital Company 796,887 9.54 501,107 6.00 501,107 6.00 Bank 867,424 10.39 501,072 6.00 668,096 8.00 Common equity tier 1 risk-based capital Company 784,960 9.40 375,830 4.50 n/a 1 n/a 1 Bank 867,424 10.39 375,804 4.50 542,828 6.50 Tier 1 leverage Company 796,887 9.17 347,731 4.00 n/a 1 n/a 1 the Bank 867,424 9.98 347,808 4.00 434,759 5.00 As of December 31, 2016 Total risk-based capital Company $ 910,040 11.71 % $ 621,870 8.00 % $ 777,338 10.00 % Bank 869,523 11.19 621,840 8.00 777,300 10.00 Tier 1 risk-based capital Company 721,600 9.28 466,403 6.00 466,403 6.00 Bank 803,374 10.34 466,380 6.00 621,840 8.00 Common equity tier 1 risk-based capital Company 709,858 9.13 349,802 4.50 n/a 1 n/a 1 Bank 803,374 10.34 349,785 4.50 505,245 6.50 Tier 1 leverage Company 721,600 8.73 330,782 4.00 n/a 1 n/a 1 Bank 803,374 9.71 330,873 4.00 413,591 5.00 1 Not applicable

Commitments and Contingent Li43

Commitments and Contingent Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Fair Value, Off-balance Sheet Risks	The contractual amounts of financial instruments with off‑balance sheet risk at December 31, 2017 and 2016 , are summarized below. Please see Part II-Item 7- "Off-Balance Sheet Arrangements, Contractual Obligation and Commitments" of this Form 10-K for information related to commitment maturities. December 31, 2017 2016 Unused commitments to extend credit $ 1,600,794 $ 1,642,528 Unused capacity on Warehouse Purchase Program loans 738,412 892,659 Standby letters of credit 34,091 29,198 Total unused commitments/capacity $ 2,373,297 $ 2,564,385

Parent Company Only Condensed44

Parent Company Only Condensed Financial Information (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule of Condensed Balance Sheet	CONDENSED BALANCE SHEETS December 31, 2017 2016 ASSETS Cash on deposit at subsidiary $ 26,692 $ 16,962 Investment in banking subsidiary 1,042,338 978,880 Receivable from banking subsidiary 12,278 10,317 ESOP note receivable and other assets 13,814 13,999 Total assets $ 1,095,122 $ 1,020,158 LIABILITIES AND SHAREHOLDERS’ EQUITY Borrowings $ 134,522 $ 134,032 Other liabilities 726 761 Shareholders’ equity 959,874 885,365 Total liabilities and shareholders’ equity $ 1,095,122 $ 1,020,158
Schedule of Condensed Income Statement	CONDENSED STATEMENTS OF INCOME December 31, 2017 2016 2015 Cash dividends from subsidiary $ 35,000 $ — $ 24,500 Excess of earnings over dividend from subsidiary 61,341 103,572 48,677 Interest income on ESOP loan 449 487 565 Interest income on subordinated debt 13 11 17 Other income — — 5 96,803 104,070 73,764 Interest expense 7,819 6,040 1,046 Operating expenses 3,754 3,236 3,009 Earnings before income tax benefit 85,230 94,794 69,709 Income tax benefit 4,264 3,027 1,207 Net income $ 89,494 $ 97,821 $ 70,916
Schedule of Condensed Cash Flow Statement	CONDENSED STATEMENTS OF CASH FLOWS December 31, 2017 2016 2015 Cash flows from operating activities Net income $ 89,494 $ 97,821 $ 70,916 Adjustments to reconcile net income to net cash from operating activities: Excess of earnings over dividend from subsidiary (61,341 ) (103,572 ) (48,677 ) Amortization 490 530 171 Activity in share-based compensation plans 5,501 3,152 3,068 Net change in other assets (207 ) (481 ) 6,931 Net change in other liabilities (35 ) (38 ) (14,544 ) Net cash provided by (used in) operating activities 33,902 (2,588 ) 17,865 Cash flows from investing activities Capital contribution (to) from subsidiary — (49,000 ) (40,000 ) Cash and cash equivalents acquired from LegacyTexas Group, Inc. — — 201 Payments received on ESOP notes receivable 393 981 1,495 Net cash provided by (used in) investing activities 393 (48,019 ) (38,304 ) Cash flows from financing activities Proceeds from borrowings — 73,439 73,407 Repayments of borrowings — (24,929 ) (24,364 ) Share repurchase — — (7,989 ) Net issuance of common stock under employee stock plans 4,712 3,755 1,284 Payment of dividends (29,277 ) (27,676 ) (25,747 ) Net cash provided by (used in) financing activities (24,565 ) 24,589 16,591 Net change in cash and cash equivalents 9,730 (26,018 ) (3,848 ) Beginning cash and cash equivalents 16,962 42,980 46,828 Ending cash and cash equivalents $ 26,692 $ 16,962 $ 42,980

Quarterly Financial Data (Una45

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	Interest Income Interest Expense Net Interest Income Provision Securities Gains and (Losses) Net Income Earnings per Share Basic Diluted 2017 First quarter $ 87,536 $ 10,988 $ 76,548 $ 22,301 1 $ (19 ) $ 18,190 0.39 0.38 Second quarter 88,747 13,027 75,720 6,255 — 27,935 0.60 0.59 Third quarter 94,463 15,499 78,964 7,157 (20 ) 28,709 0.61 0.61 Fourth quarter 96,111 15,912 80,199 3,743 — 14,660 2 0.31 0.31 2016 First quarter $ 72,608 $ 7,257 $ 65,351 $ 8,800 $ — $ 22,082 0.48 0.48 Second quarter 77,336 7,982 69,354 6,800 65 23,217 0.50 0.50 Third quarter 82,911 9,431 73,480 3,467 (3 ) 27,217 0.59 0.58 Fourth quarter 84,497 10,413 74,084 7,833 (6 ) 25,305 0.54 0.54 1 Includes the impact of a charge-off totaling $16,360 on a corporate healthcare finance relationship, which was reported in the Company's commercial and industrial loan portfolio. 2 Includes the impact of a $13,493 income tax adjustment to the Company's deferred tax asset related to the December 22, 2017 enactment of the Tax Cuts and Jobs Act.

Summary of Significant Accoun46

Summary of Significant Accounting Policies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)segmentloan_production_office	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Property, Plant and Equipment [Line Items]
Number of full-service branches | loan_production_office	44
Days past due to be considered delinquent	30 days
Days delinquent for interest on loan to be discontinued	90 days
Days delinquent for a consumer loan to be typically charged off	120 days
Consumer loans, nonperforming, period Before placed into nonaccrual status	90 days
Threshold for not being measured on an individual basis, unpaid principal for impaired financing receivable	$ 417
Troubled debt restructuring non accrual period	6 months
Performance period for troubled debt restructuring loans to return to accrual status	6 months
Advertising expense	$ 4,378	$ 3,861	$ 3,773
Number of segments | segment	1
Buildings | Minimum
Property, Plant and Equipment [Line Items]
Useful lives	10 years
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Useful lives	30 years
Furniture, fixtures and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful lives	3 years
Furniture, fixtures and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful lives	7 years

Share Transactions (Details)

Share Transactions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Aug. 31, 2012
Stockholders' Equity Note [Abstract]
Percentage of shares authorized to be repurchased				5.00%
Repurchase authorized (in shares)				1,978,871
Stock repurchased and retired during period (in shares)	0	0	357,950
Average price of stock retired (in dollars per share)			$ 22.32
Remaining available for purchase (in shares)	1,537,121

Earnings Per Common Share (Deta

Earnings 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
Numerator:
Net income									$ 89,494	$ 97,821	$ 70,916
Distributed and undistributed earnings to participating securities									(318)	(497)	(534)
Income available to common shareholders									$ 89,176	$ 97,324	$ 70,382
Denominator:
Weighted average common shares outstanding (in shares)									47,998,439	47,721,179	47,659,389
Less: Average unallocated ESOP shares (in shares)									(1,220,516)	(1,301,356)	(1,464,324)
Average unvested restricted stock awards (in shares)									(166,143)	(235,749)	(347,781)
Average shares for basic earnings per share (in shares)									46,611,780	46,184,074	45,847,284
Basic earnings per common share (in dollars per share)	$ 0.31	$ 0.61	$ 0.60	$ 0.39	$ 0.54	$ 0.59	$ 0.50	$ 0.48	$ 1.91	$ 2.11	$ 1.54
Numerator:
Income available to common shareholders									$ 89,176	$ 97,324	$ 70,382
Denominator:
Average shares for basic earnings per share (in shares)									46,611,780	46,184,074	45,847,284
Dilutive effect of share-based compensation plan (in shares)									526,738	300,893	278,163
Average shares for diluted earnings per share (in shares)									47,138,518	46,484,967	46,125,447
Diluted earnings per common share (in dollars per share)	$ 0.31	$ 0.61	$ 0.59	$ 0.38	$ 0.54	$ 0.58	$ 0.50	$ 0.48	$ 1.89	$ 2.09	$ 1.53
Share awards excluded in the computation of diluted earnings per share because the exercise price was greater than the common stock average market price and were therefore anti-dilutive (in shares)									623,666	1,384,784	1,012,771

Securities - Fair Value of Avai

Securities - Fair Value of Available-for-Sale Securities and Related Gross Unrealized Gains and Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 424,999	$ 358,692
Gross Unrealized Gains	745	805
Gross Unrealized Losses	6,027	4,982
Fair Value	419,717	354,515
Agency residential mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	191,216	220,744
Gross Unrealized Gains	419	635
Gross Unrealized Losses	2,169	2,828
Fair Value	189,466	218,551
Agency commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	9,360	9,422
Gross Unrealized Gains	0	0
Gross Unrealized Losses	125	75
Fair Value	9,235	9,347
Agency residential collateralized mortgage obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	187,637	87,959
Gross Unrealized Gains	4	22
Gross Unrealized Losses	3,425	1,452
Fair Value	184,216	86,529
US government and agency securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,590	2,150
Gross Unrealized Gains	81	101
Gross Unrealized Losses	0	0
Fair Value	1,671	2,251
Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	35,196	38,417
Gross Unrealized Gains	241	47
Gross Unrealized Losses	308	627
Fair Value	$ 35,129	$ 37,837

Securities - Carrying Amount, U

Securities - Carrying Amount, Unrecognized Gains and Losses, and Fair Value of Securities Held to Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 173,509	$ 210,387
Gross Unrealized Gains	2,549	4,315
Gross Unrealized Losses	1,132	1,721
Fair Value	174,926	212,981
Agency residential mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	57,334	74,881
Gross Unrealized Gains	616	1,147
Gross Unrealized Losses	646	817
Fair Value	57,304	75,211
Agency commercial mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	27,435	28,023
Gross Unrealized Gains	589	836
Gross Unrealized Losses	98	166
Fair Value	27,926	28,693
Agency residential collateralized mortgage obligations
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	27,112	40,707
Gross Unrealized Gains	265	697
Gross Unrealized Losses	99	33
Fair Value	27,278	41,371
Municipal bonds
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	61,628	66,776
Gross Unrealized Gains	1,079	1,635
Gross Unrealized Losses	289	705
Fair Value	$ 62,418	$ 67,706

Securities - Carrying Amount an

Securities - Carrying Amount and Fair Value of Held to Maturity Debt Securities and Fair Value of Available-for-Sale Debt Securities (Details) $ in Thousands	Dec. 31, 2017USD ($)
HTM - Amortized Cost
Due in one year or less	$ 1,365
Due after one to five years	10,699
Due after five to ten years	44,059
Due after ten years	5,505
Held to maturity, Amortized Cost	173,509
HTM - Fair Value
Due in one year or less	1,373
Due after one to five years	10,959
Due after five to ten years	44,628
Due after ten years	5,458
Fair value of securities held to maturity	174,926
AFS - Fair Value
Due in one year or less	1,526
Due after one to five years	12,726
Due after five to ten years	16,731
Due after ten years	5,817
Securities available for sale, at fair value	419,717
Agency residential mortgage-backed securities
AFS - Fair Value
Securities available for sale, at fair value	189,466
Agency commercial mortgage-backed securities
AFS - Fair Value
Securities available for sale, at fair value	9,235
Agency residential collateralized mortgage obligations
AFS - Fair Value
Securities available for sale, at fair value	184,216
Agency residential mortgage-backed securities
HTM - Amortized Cost
Held to maturity, Amortized Cost	57,334
HTM - Fair Value
Fair value of securities held to maturity	57,304
Agency commercial mortgage-backed securities
HTM - Amortized Cost
Held to maturity, Amortized Cost	27,435
HTM - Fair Value
Fair value of securities held to maturity	27,926
Agency residential collateralized mortgage obligations
HTM - Amortized Cost
Held to maturity, Amortized Cost	27,112
HTM - Fair Value
Fair value of securities held to maturity	$ 27,278

Securities - Summarized Sales A

Securities - Summarized Sales Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Proceeds	$ 0	$ 7,700	$ 36,984
Gross gains	0	72	278
Gross losses	0	7	50
Tax expense of securities gains/losses reclassified from accumulated other comprehensive income	$ 0	$ 23	$ 80

Securities - Securities with Un

Securities - Securities with Unrealized Losses Aggregated by Investment and Length of Time that Individual Securities Have Been in Continuous Unrealized Loss Position Category (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
AFS - Fair Value
Less than 12 Months	$ 207,763	$ 276,583
12 Months or More	155,968	13,577
Fair Value, Total	363,731	290,160
AFS - Unrealized Loss
Less than 12 Months	2,469	4,777
12 Months or More	3,558	205
Total	6,027	4,982
HTM - Fair Value
Less than 12 Months	41,403	74,332
12 Months or More	33,146	2,496
Fair Value, Total	74,549	76,828
HTM - Unrealized Loss
Less than 12 Months	376	1,652
12 Months or More	756	69
Total	1,132	1,721
Agency residential mortgage-backed securities
HTM - Fair Value
Less than 12 Months	20,397	41,375
12 Months or More	16,909	0
Fair Value, Total	37,306	41,375
HTM - Unrealized Loss
Less than 12 Months	206	817
12 Months or More	440	0
Total	646	817
Agency commercial mortgage-backed securities
HTM - Fair Value
Less than 12 Months	3,685	7,273
12 Months or More	3,484	0
Fair Value, Total	7,169	7,273
HTM - Unrealized Loss
Less than 12 Months	26	166
12 Months or More	72	0
Total	98	166
Agency residential collateralized mortgage obligations
HTM - Fair Value
Less than 12 Months	8,008	6,322
12 Months or More	2,267	1,451
Fair Value, Total	10,275	7,773
HTM - Unrealized Loss
Less than 12 Months	64	11
12 Months or More	35	22
Total	99	33
Municipal Bonds
HTM - Fair Value
Less than 12 Months	9,313	19,362
12 Months or More	10,486	1,045
Fair Value, Total	19,799	20,407
HTM - Unrealized Loss
Less than 12 Months	80	658
12 Months or More	209	47
Total	289	705
Agency residential mortgage-backed securities
AFS - Fair Value
Less than 12 Months	59,545	167,503
12 Months or More	100,214	7,516
Fair Value, Total	159,759	175,019
AFS - Unrealized Loss
Less than 12 Months	412	2,770
12 Months or More	1,757	58
Total	2,169	2,828
Agency commercial mortgage-backed securities
AFS - Fair Value
Less than 12 Months	9,235	9,347
12 Months or More	0	0
Fair Value, Total	9,235	9,347
AFS - Unrealized Loss
Less than 12 Months	125	75
12 Months or More	0	0
Total	125	75
Agency residential collateralized mortgage obligations
AFS - Fair Value
Less than 12 Months	128,869	72,822
12 Months or More	49,171	2,649
Fair Value, Total	178,040	75,471
AFS - Unrealized Loss
Less than 12 Months	1,860	1,420
12 Months or More	1,565	32
Total	3,425	1,452
Municipal Bonds
AFS - Fair Value
Less than 12 Months	10,114	26,911
12 Months or More	6,583	3,412
Fair Value, Total	16,697	30,323
AFS - Unrealized Loss
Less than 12 Months	72	512
12 Months or More	236	115
Total	$ 308	$ 627

Securities - Narrative (Details

Securities - Narrative (Details) $ in Thousands	Dec. 31, 2017USD ($)security	Dec. 31, 2016USD ($)
Investments, Debt and Equity Securities [Abstract]
Held-to-maturity securities pledged as collateral | $	$ 256,451	$ 224,674
Number of securities in unrealized loss position	259
Number of securities in unrealized loss position for more than one year	122

Loans - Loans (Details)

Loans - Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale, at fair value	$ 16,707	$ 21,279
Gross loans held for investment, excluding Warehouse Purchase Program	6,649,450	6,065,423	$ 5,066,507
Deferred costs (fees) and discounts, net	6,380	(2,251)
Allowance for loan losses	(71,301)	(64,576)
Net loans held for investment, excluding Warehouse Purchase Program	6,584,529	5,998,596
Warehouse Purchase Program	1,154,588	1,055,341
Total loans held for investment	7,739,117	7,053,937
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans held for investment, excluding Warehouse Purchase Program	3,019,339	2,670,455	2,177,543
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans held for investment, excluding Warehouse Purchase Program	2,093,307	1,971,160	1,612,669
Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans held for investment, excluding Warehouse Purchase Program	277,864	294,894	269,708
Consumer real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans held for investment, excluding Warehouse Purchase Program	1,213,434	1,074,923	936,757
Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans held for investment, excluding Warehouse Purchase Program	$ 45,506	$ 53,991	$ 69,830

Loans - Narrative (Details)

Loans - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Receivables [Abstract]
Carrying amount, net of allowance	$ 269,000	$ 180,000	$ 150,000
Loans past due over 90 days and still accruing	0	141,000
PCI loans that are considered non-performing	0
Interest that would have been recognized on non-accrual loans if performing	$ 4,229,000	$ 1,746,000	$ 1,594,000
Troubled debt restructuring, default payment	90 days

Loans - Allowance for Loan Loss

Loans - Allowance for Loan 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
Allowance for loan losses:
Balance at beginning of period				$ 64,576				$ 47,093	$ 64,576	$ 47,093	$ 25,549
Charge-offs									(34,742)	(8,859)	(4,707)
Recoveries									1,367	942	786
Provision expense (benefit)	$ 3,743	$ 7,157	$ 6,255	22,301	$ 7,833	$ 3,467	$ 6,800	8,800	40,100	25,400	25,465
Balance at end of period	71,301				64,576				71,301	64,576	47,093
Allowance ending balance:
Individually evaluated for impairment	10,791				5,011				10,791	5,011	1,978
Collectively evaluated for impairment	60,510				59,565				60,510	59,565	45,115
Loans:
Individually evaluated for impairment	91,166				106,619				91,166	106,619	33,406
Collectively evaluated for impairment	6,554,720				5,951,831				6,554,720	5,951,831	5,021,147
PCI loans	3,564				6,973				3,564	6,973	11,954
Total	6,649,450				6,065,423				6,649,450	6,065,423	5,066,507
Commercial real estate
Allowance for loan losses:
Balance at beginning of period				18,303				14,123	18,303	14,123	11,830
Charge-offs									(16)	(79)	(167)
Recoveries									205	21	29
Provision expense (benefit)									3,095	4,238	2,431
Balance at end of period	21,587				18,303				21,587	18,303	14,123
Allowance ending balance:
Individually evaluated for impairment	0				300				0	300	366
Collectively evaluated for impairment	21,587				18,003				21,587	18,003	13,757
Loans:
Individually evaluated for impairment	4,134				5,195				4,134	5,195	11,580
Collectively evaluated for impairment	3,012,892				2,659,644				3,012,892	2,659,644	2,155,351
PCI loans	2,313				5,616				2,313	5,616	10,612
Total	3,019,339				2,670,455				3,019,339	2,670,455	2,177,543
Commercial and industrial
Allowance for loan losses:
Balance at beginning of period				35,464				24,975	35,464	24,975	9,068
Charge-offs									(32,846)	(7,746)	(3,129)
Recoveries									405	472	246
Provision expense (benefit)									35,982	17,763	18,790
Balance at end of period	39,005				35,464				39,005	35,464	24,975
Allowance ending balance:
Individually evaluated for impairment	10,527				4,521				10,527	4,521	1,470
Collectively evaluated for impairment	28,478				30,943				28,478	30,943	23,505
Loans:
Individually evaluated for impairment	84,005				86,664				84,005	86,664	16,906
Collectively evaluated for impairment	2,009,126				1,884,263				2,009,126	1,884,263	1,595,548
PCI loans	176				233				176	233	215
Total	2,093,307				1,971,160				2,093,307	1,971,160	1,612,669
Construction and land
Allowance for loan losses:
Balance at beginning of period				5,075				3,013	5,075	3,013	174
Charge-offs									(418)	0	0
Recoveries									75	0	0
Provision expense (benefit)									(88)	2,062	2,839
Balance at end of period	4,644				5,075				4,644	5,075	3,013
Allowance ending balance:
Individually evaluated for impairment	0				0				0	0	0
Collectively evaluated for impairment	4,644				5,075				4,644	5,075	3,013
Loans:
Individually evaluated for impairment	0				11,385				0	11,385	33
Collectively evaluated for impairment	277,864				283,509				277,864	283,509	269,675
PCI loans	0				0				0	0	0
Total	277,864				294,894				277,864	294,894	269,708
Consumer real estate
Allowance for loan losses:
Balance at beginning of period				4,484				3,992	4,484	3,992	4,069
Charge-offs									(96)	(107)	(321)
Recoveries									42	109	85
Provision expense (benefit)									408	490	159
Balance at end of period	4,838				4,484				4,838	4,484	3,992
Allowance ending balance:
Individually evaluated for impairment	230				138				230	138	81
Collectively evaluated for impairment	4,608				4,346				4,608	4,346	3,911
Loans:
Individually evaluated for impairment	2,992				3,300				2,992	3,300	4,767
Collectively evaluated for impairment	1,209,550				1,070,732				1,209,550	1,070,732	931,140
PCI loans	892				891				892	891	850
Total	1,213,434				1,074,923				1,213,434	1,074,923	936,757
Other consumer
Allowance for loan losses:
Balance at beginning of period				$ 1,250				$ 990	1,250	990	408
Charge-offs									(1,366)	(927)	(1,090)
Recoveries									640	340	426
Provision expense (benefit)									703	847	1,246
Balance at end of period	1,227				1,250				1,227	1,250	990
Allowance ending balance:
Individually evaluated for impairment	34				52				34	52	61
Collectively evaluated for impairment	1,193				1,198				1,193	1,198	929
Loans:
Individually evaluated for impairment	35				75				35	75	120
Collectively evaluated for impairment	45,288				53,683				45,288	53,683	69,433
PCI loans	183				233				183	233	277
Total	$ 45,506				$ 53,991				$ 45,506	$ 53,991	$ 69,830

Loans - Allowance for Off-Balan

Loans - Allowance for Off-Balance Sheet Credit Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for loan losses:
Balance at beginning of period	$ 64,576	$ 47,093	$ 25,549
Charge-offs on lending-related commitments	(34,742)	(8,859)	(4,707)
Balance at end of period	71,301	64,576	47,093
Other liabilities
Allowance for loan losses:
Balance at beginning of period	1,573	73
Charge-offs on lending-related commitments	0	0
Provision (recovery) for credit losses on lending-related commitments	(644)	1,500
Balance at end of period	$ 929	$ 1,573	$ 73

Loans - Impaired Loans (Details

Loans - Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	$ 97,740	$ 108,401
Recorded Investment With No Allowance	55,598	92,514
Recorded Investment With Allowance	35,568	14,105
Total Recorded Investment	91,166	106,619
Related Allowance	10,522	4,831
Average Recorded Investment	93,252	39,701	$ 33,328
Interest Income Recognized	26	28	41
Commercial real estate
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	4,411	5,388
Recorded Investment With No Allowance	4,134	4,429
Recorded Investment With Allowance	0	766
Total Recorded Investment	4,134	5,195
Related Allowance	0	272
Average Recorded Investment	4,421	5,240	8,178
Interest Income Recognized	8	9	24
Commercial and industrial
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	89,713	87,756
Recorded Investment With No Allowance	48,463	73,377
Recorded Investment With Allowance	35,542	13,287
Total Recorded Investment	84,005	86,664
Related Allowance	10,502	4,519
Average Recorded Investment	83,508	28,634	19,595
Interest Income Recognized	0	1	8
Construction and land
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance		11,384
Recorded Investment With No Allowance		11,385
Recorded Investment With Allowance		0
Total Recorded Investment		11,385
Related Allowance		0
Average Recorded Investment	2,273	901	84
Interest Income Recognized	0	0	0
Consumer real estate
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	3,545	3,766
Recorded Investment With No Allowance	2,985	3,290
Recorded Investment With Allowance	7	10
Total Recorded Investment	2,992	3,300
Related Allowance	7	10
Average Recorded Investment	2,786	4,831	5,269
Interest Income Recognized	14	14	7
Other consumer
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	71	107
Recorded Investment With No Allowance	16	33
Recorded Investment With Allowance	19	42
Total Recorded Investment	35	75
Related Allowance	13	30
Average Recorded Investment	264	95	202
Interest Income Recognized	$ 4	$ 4	$ 2

Loans - Non-Performing (Nonaccr

Loans - Non-Performing (Nonaccrual) Loans (Details) - Non-performing - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-performing loans	$ 94,403	$ 111,389
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-performing loans	4,134	5,195
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-performing loans	84,003	86,664
Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-performing loans	0	11,385
Consumer real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-performing loans	6,190	7,987
Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-performing loans	$ 76	$ 158

Loans - Outstanding Balances of

Loans - Outstanding Balances of TDRs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
TDRs	$ 18,062	$ 12,155
Outstanding commitments to lend additional funds to borrowers with TDR loans	$ 0	0
Troubled debt restructuring non accrual period	6 months
Nonaccrual TDRs
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
TDRs	$ 17,294	11,701
Performing TDRs
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
TDRs	$ 768	$ 454

Loans - Recorded Balances of Lo

Loans - Recorded Balances of Loans Modified as TDRs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR	$ 14,232	$ 7,855	$ 600
Principal Deferrals
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR	38	686	310
Combination of Rate Reduction & Principal Deferral
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR	131	79	60
Other
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR	14,063	7,090	230
Commercial real estate
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR			100
Commercial real estate | Principal Deferrals
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR			100
Commercial real estate | Combination of Rate Reduction & Principal Deferral
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR			0
Commercial real estate | Other
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR			0
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR	14,232	7,775	191
Commercial and industrial | Principal Deferrals
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR	38	685	0
Commercial and industrial | Combination of Rate Reduction & Principal Deferral
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR	131	0	0
Commercial and industrial | Other
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR	14,063	7,090	191
Consumer real estate
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR		79	305
Loan modified as a TDR which experienced subsequent payment default	$ 0	31	178
Consumer real estate | Principal Deferrals
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR		0	209
Consumer real estate | Combination of Rate Reduction & Principal Deferral
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR		79	60
Consumer real estate | Other
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR		0	36
Other consumer
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR		1	4
Other consumer | Principal Deferrals
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR		1	1
Other consumer | Combination of Rate Reduction & Principal Deferral
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR		0	0
Other consumer | Other
Financing Receivable, Modifications [Line Items]
Loans modified as a TDR		$ 0	$ 3

Loans - Carrying Amount of Acqu

Loans - Carrying Amount of Acquired PCI Loans Included in the Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Receivables [Abstract]
Carrying amount	$ 3,295	$ 6,793
Outstanding balance	3,992	7,597
Carrying amount, net of allowance	$ 269	$ 180	$ 150

Loans - Changes in the Accretab

Loans - Changes in the Accretable Yield for Acquired PCI Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 2,515	$ 3,356
Reclassifications from nonaccretable	602	429
Disposals	(187)	(359)
Accretion	(651)	(911)
Balance at end of period	$ 2,279	$ 2,515

Loans - Analysis of Age of Reco

Loans - Analysis of Age of Recorded Investment in Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	$ 49,228	$ 59,080
Current Loans	6,600,222	6,006,343
Total Loans	6,649,450	6,065,423
Carrying value of PCI loans acquired	3,338	6,729
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	37,013	54,266
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	3,246	2,797
90 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	8,969	2,017
Commercial real estate
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	9,664	2,667
Current Loans	3,009,675	2,667,788
Total Loans	3,019,339	2,670,455
Commercial real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	9,414	1,829
Commercial real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	0	72
Commercial real estate | 90 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	250	766
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	8,552	21,451
Current Loans	2,084,755	1,949,709
Total Loans	2,093,307	1,971,160
Commercial and industrial | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	918	20,910
Commercial and industrial | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	284	495
Commercial and industrial | 90 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	7,350	46
Construction and land
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	9,354	19,800
Current Loans	268,510	275,094
Total Loans	277,864	294,894
Construction and land | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	9,354	19,517
Construction and land | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	0	283
Construction and land | 90 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	0	0
Consumer real estate
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	20,731	13,602
Current Loans	1,192,703	1,061,321
Total Loans	1,213,434	1,074,923
Consumer real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	16,436	10,487
Consumer real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	2,928	1,916
Consumer real estate | 90 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	1,367	1,199
Other consumer
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	927	1,560
Current Loans	44,579	52,431
Total Loans	45,506	53,991
Other consumer | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	891	1,523
Other consumer | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	34	31
Other consumer | 90 Days and Greater Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	$ 2	$ 6

Loans - Real Estate and Commerc

Loans - Real Estate and Commercial and Industrial Credit Risk Profile by Internally Assigned Grade (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 6,649,450	$ 6,065,423
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	3,019,339	2,670,455
Commercial real estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,980,656	2,648,842
Commercial real estate | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	30,656	7,972
Commercial real estate | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	8,027	12,875
Commercial real estate | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	766
Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,093,307	1,971,160
Commercial and industrial | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,953,496	1,712,171
Commercial and industrial | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	43,161	155,110
Commercial and industrial | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	96,546	103,815
Commercial and industrial | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	104	64
Construction and land
Financing Receivable, Recorded Investment [Line Items]
Total Loans	277,864	294,894
Construction and land | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	277,864	283,423
Construction and land | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Construction and land | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	11,471
Construction and land | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Consumer real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,213,434	1,074,923
Consumer real estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,203,236	1,062,549
Consumer real estate | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,408	2,083
Consumer real estate | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	7,762	8,252
Consumer real estate | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 1,028	$ 2,039

Loans - Consumer Credit Exposur

Loans - Consumer Credit Exposure Credit Risk Profile Based on Payment Activity (Details) - Other consumer - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total	$ 45,506	$ 53,991
Performing
Financing Receivable, Recorded Investment [Line Items]
Total	45,430	53,833
Non-performing
Financing Receivable, Recorded Investment [Line Items]
Total	$ 76	$ 158

Fair Value - Assets and Liabili

Fair Value - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	$ 419,717,000	$ 354,515,000
Outstanding principal	16,242,000
Interest rate lock commitments | Derivatives not designated as hedging instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	358,000	379,000
Derivative liability	0	0
Forward mortgage-backed securities trades | Derivatives not designated as hedging instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	7,000	36,000
Derivative liability	18,000	80,000
Agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	189,466,000	218,551,000
Agency commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	9,235,000	9,347,000
Agency residential collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	184,216,000	86,529,000
US government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	1,671,000	2,251,000
Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	35,129,000	37,837,000
Level 2 | Recurring | Derivatives not designated as hedging instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	419,717,000	354,515,000
Loans held for sale	16,707,000	21,279,000
Level 2 | Recurring | Interest rate lock commitments | Derivatives not designated as hedging instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	358,000	379,000
Derivative liability	0	0
Level 2 | Recurring | Forward mortgage-backed securities trades | Derivatives not designated as hedging instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	7,000	36,000
Derivative liability	18,000	80,000
Level 2 | Recurring | Commercial loan interest rate swaps and caps: | Loan customer counterparty | Derivatives not designated as hedging instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	1,735,000	1,369,000
Level 2 | Recurring | Commercial loan interest rate swaps and caps: | Financial institution counterparty | Derivatives not designated as hedging instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	1,735,000	1,369,000
Derivative liability	0	0
Level 2 | Recurring | Agency residential mortgage-backed securities | Derivatives not designated as hedging instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	189,466,000	218,551,000
Level 2 | Recurring | Agency commercial mortgage-backed securities | Derivatives not designated as hedging instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	9,235,000	9,347,000
Level 2 | Recurring | Agency residential collateralized mortgage obligations | Derivatives not designated as hedging instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	184,216,000	86,529,000
Level 2 | Recurring | US government and agency securities | Derivatives not designated as hedging instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	1,671,000	2,251,000
Level 2 | Recurring | Municipal bonds | Derivatives not designated as hedging instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	$ 35,129,000	$ 37,837,000

Fair Value - Narrative (Details

Fair Value - Narrative (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value	$ 0	$ 0
Mortgage loans on real estate, pending foreclosures	$ 400,000

Fair Value - Assets and Liabi70

Fair Value - Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis (Details) - Level 3 - Non-recurring - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ 25,046	$ 9,274
Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets	6,694	10,638
Construction and land
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets	859	194
Consumer real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets	192	0
Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets	$ 687	$ 6

Fair Value - Fair Value of Fina

Fair Value - Fair Value of Financial Instruments Not Recorded at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financial assets
Cash and cash equivalents	$ 293,456	$ 289,212	$ 615,639	$ 132,021
Securities held to maturity	173,509	210,387
Securities held to maturity	174,926	212,981
Loans held for investment, net	6,584,529	5,998,596
Loans held for investment - Warehouse Purchase Program	1,154,588	1,055,341
FHLB and other restricted securities, at cost	64,790	43,266
Accrued interest receivable	24,596	20,347
Financial liabilities
Deposits	6,767,683	6,365,476
FHLB advances	1,043,163	833,682
Repurchase agreements	84,676	86,691
Subordinated debt	134,522	134,032
Accrued interest payable	2,729	2,111
Level 1
Financial assets
Cash and cash equivalents	293,456	289,212
Securities held to maturity	0	0
Loans held for investment, net	0	0
Loans held for investment - Warehouse Purchase Program	0	0
FHLB and other restricted securities, at cost	0	0
Accrued interest receivable	24,596	20,347
Financial liabilities
Deposits	0	0
FHLB advances	0	0
Repurchase agreements	0	0
Subordinated debt	0	0
Accrued interest payable	2,729	2,111
Level 2
Financial assets
Cash and cash equivalents	0	0
Securities held to maturity	174,926	212,981
Loans held for investment, net	0	0
Loans held for investment - Warehouse Purchase Program	0	0
FHLB and other restricted securities, at cost	64,790	43,266
Accrued interest receivable	0	0
Financial liabilities
Deposits	0	0
FHLB advances	0	0
Repurchase agreements	0	0
Subordinated debt	0	0
Accrued interest payable	0	0
Level 3
Financial assets
Cash and cash equivalents	0	0
Securities held to maturity	0	0
Loans held for investment, net	6,651,207	6,080,165
Loans held for investment - Warehouse Purchase Program	1,171,354	1,055,219
FHLB and other restricted securities, at cost	0	0
Accrued interest receivable	0	0
Financial liabilities
Deposits	6,326,572	5,989,933
FHLB advances	1,043,416	830,930
Repurchase agreements	81,041	84,265
Subordinated debt	141,972	121,743
Accrued interest payable	$ 0	$ 0

Derivative Financial Instrume72

Derivative Financial Instruments - Schedule of Outstanding Notional Balances and Fair Values of Outstanding Positions (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
IRLC's
Derivative Asset
Outstanding Notional Balance	$ 10,337	$ 10,952
Asset Derivative Fair Value	358	379
Derivative Liability
Liability Derivative Fair Value	0	0
Forward mortgage-backed securities trades
Derivative Asset
Outstanding Notional Balance	19,788	18,613
Asset Derivative Fair Value	7	36
Derivative Liability
Liability Derivative Fair Value	18	80
Commercial loan interest rate swaps and caps: | Commercial loan | Loan customer counterparty
Derivative Asset
Asset Derivative Fair Value	0	0
Derivative Liability
Outstanding Notional Balance	114,594	112,294
Liability Derivative Fair Value	1,735	1,369
Commercial loan interest rate swaps and caps: | Commercial loan | Financial institution counterparty
Derivative Asset
Outstanding Notional Balance	114,594	112,294
Asset Derivative Fair Value	1,735	1,369
Derivative Liability
Liability Derivative Fair Value	$ 0	$ 0

Derivative Financial Instrume73

Derivative Financial Instruments - Schedule of Notional Amounts of Outstanding Derivative Positions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, collateral pledged	$ 1,950	$ 1,950
Commercial loan interest rate swaps and caps:
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Credit exposure	32
IRLC's
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Income/loss	(21)	(43)	$ 8
Forward mortgage-backed securities trades
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Income/loss	(479)	$ 13	$ (195)
Financial institution counterparty | Commercial loan interest rate swaps and caps:
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Credit exposure	$ 1,752
Loan customer counterparty | Commercial loan | Derivatives not designated as hedging instruments | Commercial loan interest rate swaps and caps:
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Received	2.52%	3.12%
Paid	2.54%	2.36%

Premises and Equipment (Details

Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 109,492	$ 110,169
Less: accumulated depreciation	(39,799)	(35,943)
Total	69,693	74,226
Land
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	22,140	23,636
Buildings
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	57,079	59,298
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	20,218	19,561
Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 10,055	$ 7,674

Premises and Equipment - Narrat

Premises and Equipment - Narrative (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2017USD ($)	Dec. 31, 2017USD ($)Parcel_of_land	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Property, Plant and Equipment [Abstract]
Depreciation		$ 6,389	$ 6,186	$ 6,550
Rent expense		7,322	$ 7,928	$ 6,895
Rental income		1,102
Rent payments receivable in the future		$ 105
Number of parcels of land for future development | Parcel_of_land		1
Gain on sale of land	$ 1,304

Premises and Equipment - Rent C

Premises and Equipment - Rent Commitments (Details) $ in Thousands	Dec. 31, 2017USD ($)
Property, Plant and Equipment [Abstract]
2,018	$ 5,725
2,019	5,069
2,020	4,696
2,021	4,443
2,022	3,735
Thereafter	16,303
Total	$ 39,971

Goodwill and Core Deposit Int77

Goodwill and Core Deposit Intangibles - Changes In Carrying Amount of Company's Goodwill and Core Deposit Intangibles (Cdi) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill
Balance	$ 178,559	$ 180,776
Disposition of insurance subsidiary goodwill upon the sale of subsidiary operations		(2,217)
Balance	178,559	178,559
Core Deposit Intangibles
Balance	665	1,030
Amortization of core deposit intangible	(263)	(365)
Balance	$ 402	$ 665

Goodwill and Core Deposit Int78

Goodwill and Core Deposit Intangibles - Estimated Aggregate Future Amortization Expense for Intangible Assets Remaining (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Finite-Lived Intangible Assets [Line Items]
2,018	$ 156
2,019	101
2,020	73
2,021	48
2,022	24
Thereafter	$ 0
Core deposits
Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period	8 years

Deposits - Narrative (Details)

Deposits - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Banking and Thrift [Abstract]
FDIC uninsured amount	$ 1,009,855	$ 951,688
Reciprocal deposits	400,716	355,455
Deposits of public funds	972,226	1,001,820
Unsecured customer loans	$ 473	$ 340

Deposits - Scheduled Maturity o

Deposits - Scheduled Maturity of Time Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Balance
2,018	$ 860,102
2,019	383,687
2,020	41,093
2,021	59,074
2022 and thereafter	23,434
Total	$ 1,367,390	$ 1,367,904
Weighted Average Rate
2,018	1.16%
2,019	1.57%
2,020	1.47%
2,021	1.59%
2022 and thereafter	1.57%
Total	1.31%

Deposits - Interest Expense on

Deposits - Interest Expense on Deposits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Banking and Thrift [Abstract]
Interest-bearing demand	$ 5,475	$ 3,974	$ 3,297
Savings and money market	16,845	7,288	3,644
Time	14,374	9,772	6,186
Total	$ 36,694	$ 21,034	$ 13,127

Borrowed Funds - Summary of Bor

Borrowed Funds - Summary of Borrowed Funds (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Nov. 30, 2015
Debt Instrument [Line Items]
Federal Home Loan Bank advances	$ 1,043,163,000	$ 833,682,000
Repurchase Agreements	84,676,000	86,691,000
FHLB Advances
Debt Instrument [Line Items]
Federal Home Loan Bank advances	$ 1,043,163,000	$ 833,682,000
Federal Home Loan Bank advances, rate	1.51%	0.71%
FHLB Advances | Maximum
Debt Instrument [Line Items]
Federal Home Loan Bank advances, rate	6.00%	6.00%
Subordinated Debt
Debt Instrument [Line Items]
Subordinated debt	$ 125,000,000	$ 125,000,000	$ 50,000,000	$ 75,000,000
Debt, rate	5.50%	5.58%	5.69%	5.50%
Repurchase Agreements | Credit Suisse
Debt Instrument [Line Items]
Repurchase Agreements	$ 25,000,000	$ 25,000,000
Debt, rate	3.02%	3.02%
Repurchase Agreements | Overnight Maturity
Debt Instrument [Line Items]
Repurchase Agreements	$ 59,676,000	$ 61,691,000
Debt, rate	1.18%	0.15%
Trust III Debentures | Junior Subordinated Debt | Legacy Capital Trust III
Debt Instrument [Line Items]
Fixed to floating rate note maturing on December 1, 2025	$ 15,464,000	$ 15,464,000
LIBOR | Trust III Debentures | Junior Subordinated Debt
Debt Instrument [Line Items]
Junior subordinated debentures, rate	3.29%	2.66%

Borrowed Funds - FHLB Advances

Borrowed Funds - FHLB Advances (Details) - FHLB Advances - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal home loan bank, interest rate	1.51%	0.71%
Variable rate federal home loan bank advances outstanding	$ 200,000
Restructuring prepayment penalty	0	$ 27
Credit available based on collateralized values	2,084,944	1,821,693
Maximum borrowing capacity	4,072,477	3,601,739
Mortgage and Commercial Loans With Federal Home Loan Bank
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal home loan bank, collateral pledges	$ 2,106,571	$ 1,877,506
Minimum
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal home loan bank, interest rate	1.30%	0.46%
Maximum
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal home loan bank, interest rate	6.00%	6.00%

Borrowed Funds - Repurchase Agr

Borrowed Funds - Repurchase Agreement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Investment Holdings [Line Items]
Repurchase agreements	$ 84,676	$ 86,691
Repurchase Agreements
Investment Holdings [Line Items]
Term of repurchase agreement	10 years
Variable rate on repurchase agreement	6.25%
Overnight Maturity
Investment Holdings [Line Items]
Assets sold under agreements to repurchase, market value protection percentage	115.00%
Overnight Maturity | Repurchase Agreements
Investment Holdings [Line Items]
Repurchase agreements	$ 59,676	$ 61,691
Interest rate maximum on repurchase agreement	1.18%	0.15%
Credit Suisse
Investment Holdings [Line Items]
Assets sold under agreements to repurchase, market value protection percentage	112.00%
Credit Suisse | Repurchase Agreements
Investment Holdings [Line Items]
Repurchase agreements	$ 25,000	$ 25,000
Interest rate maximum on repurchase agreement	3.02%	3.02%

Borrowed Funds - Subordinated D

Borrowed Funds - Subordinated Debt and Other Borrowings (Details) - USD ($)	Jan. 01, 2015	Nov. 30, 2015	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2016
Debt Instrument [Line Items]
Trust preferred securities, purchase accounting adjustments			$ 3,537,000	$ 3,723,000
Subordinated Debt
Debt Instrument [Line Items]
Debt face amount		$ 75,000,000	$ 125,000,000	$ 125,000,000	$ 50,000,000
Debt, rate		5.50%	5.50%	5.58%	5.69%
Redemption price		100.00%
Unamortized discount and debt issuance costs			$ 2,405,000
LIBOR | Subordinated Debt
Debt Instrument [Line Items]
Basis spread on variable rate		3.99%
Trust III Debentures | LIBOR | Junior Subordinated Debt
Debt Instrument [Line Items]
Basis spread on variable rate	1.70%
Long-term debt, percentage bearing variable interest, percentage rate			3.29%	2.66%
Legacy Capital Trust III
Debt Instrument [Line Items]
Trust preferred securities, value	$ 15,000,000
Trust preferred securities purchased (in shares)	15,000
Trust preferred securities, liquidation amount (in dollars per share)	$ 1,000
Common stock, value	$ 464,000
Legacy Capital Trust III | Trust III Debentures | Junior Subordinated Debt
Debt Instrument [Line Items]
Fixed to floating rate note maturing on December 1, 2025			$ 15,464,000	$ 15,464,000
Legacy Capital Trust II
Debt Instrument [Line Items]
Trust preferred securities, value	15,000,000
Common stock, value	$ 464,000

Borrowed Funds - Other Borrowin

Borrowed Funds - Other Borrowing Information (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2015
Long-term Debt [Line Items]
2,018	$ 1,122,430
2,019	2,313
2,020	932
2,021	856
2,022	695
Thereafter	141,077
Total, Balance	1,268,303
Borrowing capacity	250,000	$ 255,000
Federal Reserve Bank
Long-term Debt [Line Items]
Borrowing capacity	78,616	$ 46,725
FHLB Advances
Long-term Debt [Line Items]
2,018	1,037,754
2,019	2,313
2,020	932
2,021	856
2,022	695
Thereafter	613
Total, Balance	1,043,163
Repurchase Agreements
Long-term Debt [Line Items]
2,018	84,676
2,019	0
2,020	0
2,021	0
2,022	0
Thereafter	0
Total, Balance	84,676
Subordinated Debt
Long-term Debt [Line Items]
2,018	0
2,019	0
2,020	0
2,021	0
2,022	0
Thereafter	140,464
Total, Balance	$ 140,464
Notes Payable, Other Payables
Long-term Debt [Line Items]
Total, Balance			$ 8,900

Benefits - Employee Stock Owner

Benefits - Employee Stock Ownership and 401(k) Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2010
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Matching contributions	100.00%
Employees qualifying compensation, maximum	5.00%
Matching expense	$ 2,571	$ 2,479	$ 2,130
Recourse provision minimum	30 years
Net proceeds from long-term debt				$ 15,886
Shares held in ESOP (in shares)	2,298,076
Allocated ESOP shares (in shares)	1,105,983
Unearned ESOP shares (in shares)	1,192,093	1,245,046
Fair value of unearned ESOP shares	$ 50,318
Employee stock ownership plan (ESOP), cash contributions	842	$ 1,468	2,060
Employee stock ownership plan (ESOP), allocated compensation expense	$ 2,074	$ 3,174	$ 4,914
Common Stock
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Contributed to ESOP (in shares)				1,588,587

Benefits - Deferred Compensatio

Benefits - Deferred Compensation Plan and Bank-Owned Life Insurance (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Deferred compensation accrued liability	$ 3,393	$ 3,344
Other assets	72,964	80,397
Bank-owned life insurance	57,684	56,477
Non qualified
Defined Benefit Plan Disclosure [Line Items]
Other assets	$ 3,588	$ 3,534

Share-based Compensation - Narr

Share-based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, grants in period, weighted average grant date fair value (in dollars per share)	$ 10.76	$ 7.77	$ 6.82
Estimated forfeiture rate	5.00%
Total intrinsic value of stock options exercised	$ 4,084	$ 2,251	$ 644
Income tax deductions in excess of compensation cost	4,510
Tax benefit	$ 1,578	0	$ 0
2017 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (in shares)	3,250,000
Fungible share rate	2.5
Shares issued (in shares)	10,500
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense related to non-vested shares	$ 2,887
Weighted-average period	1 year 1 month 2 days
Vested, weighted-average grant date fair value	$ 2,819	$ 2,615
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense related to non-vested shares	$ 8,013
Weighted-average period	1 year 11 months 9 days
Contractual term	10 years

Share-based Compensation - Comp

Share-based Compensation - Compensation Cost Charged to Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Compensation cost charged to income for:
Income tax benefit	$ 2,612	$ 2,105	$ 1,917
Restricted stock
Compensation cost charged to income for:
Compensation cost	3,581	3,477	3,459
Stock options
Compensation cost charged to income for:
Compensation cost	$ 3,881	$ 2,537	$ 2,018

Share-based Compensation - Chan

Share-based Compensation - Changes in the Nonvested Shares for the Company's Stock Plans (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Time-Vested Shares
Shares
Beginning non-vested shares (in shares)	200,176	246,461	297,603
Granted (in shares)	19,208	55,180	80,000
Vested (in shares)	(90,796)	(101,465)	(131,142)
Ending non-vested shares (in shares)	128,588	200,176	246,461
Weighted-average grant date fair value per share
Beginning non-vested shares (in dollars per share)	$ 23.79	$ 20.98	$ 20.45
Granted (in dollars per share)	38.92	29.29	21.23
Vested (in dollars per share)	21.67	20.70	19.98
Ending non-vested shares (in dollars per share)	$ 27.27	$ 23.79	$ 20.98
Performance-Based Shares
Shares
Beginning non-vested shares (in shares)	81,400	61,800	82,400
Granted (in shares)	12,208	40,200	0
Vested (in shares)	(20,600)	(20,600)	(20,600)
Ending non-vested shares (in shares)	73,008	81,400	61,800
Weighted-average grant date fair value per share
Beginning non-vested shares (in dollars per share)	$ 43.06	$ 25.02	$ 23.89
Granted (in dollars per share)	39.90	29.29	0
Vested (in dollars per share)	41.32	25.02	23.89
Ending non-vested shares (in dollars per share)	$ 42.21	$ 43.06	$ 25.02

Share-based Compensation - Unde

Share-based Compensation - Underlying Assumptions for Fair Value Calculations (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk-free interest rate	2.18%	1.37%	1.80%
Expected term of stock options (years)	6 years 2 months 12 days	6 years 3 months 16 days	6 years 2 months 28 days
Expected stock price volatility	31.85%	32.07%	31.14%
Expected dividends	1.61%	1.93%	1.95%

Share-based Compensation - Summ

Share-based Compensation - Summary of Activity in the Stock Option Portion of the Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Shares
Beginning (in shares)	2,008,080	1,865,750	1,370,873
Granted (in shares)	513,375	392,838	633,000
Exercised (in shares)	(221,984)	(175,192)	(58,855)
Forfeited (in shares)	(92,228)	(75,316)	(79,268)
Ending (in shares)	2,207,243	2,008,080	1,865,750	1,370,873
Fully vested and expected to vest (in shares)	2,191,740
Exercisable (in shares)	966,527
Weighted- Average Exercise Price per Share
Beginning (in dollars per share)	$ 23.71	$ 22.21	$ 20.27
Granted (in dollars per share)	37.15	29.15	25.66
Exercised (in dollars per share)	21.23	19.08	16.12
Forfeited (in dollars per share)	28.80	25.57	20.89
Beginning (in dollars per share)	26.88	$ 23.71	$ 22.21	$ 20.27
Fully vested and expected to vest (in dollars per share)	26.82
Exercisable (in dollars per share)	$ 22.11
Weighted- Average Remaining Contractual Term
Outstanding	10 years 1 month 6 days	9 years 6 months 5 days	7 years 10 months 8 days	8 years 8 days
Fully vested and expected to vest	10 years 1 month 6 days
Exercisable	7 years 6 months
Aggregate Intrinsic Value
Outstanding	$ 33,848	$ 38,850	$ 6,401	$ 5,679
Fully vested and expected to vest	33,725
Exercisable	$ 19,425

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Provisional amount recorded related to remeasurement of deferred tax assets	$ 13,493
Combined federal income tax rate and state margin tax rate	36.00%	36.00%	36.00%
Federal statutory rate	35.00%	35.00%	35.00%

Income Taxes - Income Tax Expen

Income Taxes - Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Current expense	$ 56,341	$ 59,900	$ 38,648
Deferred expense	(4,115)	(6,798)	(692)
Impact of Tax Cuts and Jobs Act - net future deductions	12,752	0	0
Impact of Tax Cuts and Jobs Act - unrealized loss on AFS securities	741	0	0
Total income tax expense	$ 65,719	$ 53,102	$ 37,956

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Allowance for loan losses	$ 15,168	$ 22,602
Deferred compensation arrangements	762	1,261
Self-funded health insurance	251	241
Non-accrual interest	503	966
Restricted stock and stock options	2,577	3,132
Accrued expenses	623	1,255
Fair value mark on purchased loans	965	2,348
Net unrealized loss on securities available for sale	1,111	1,465
Other	1,909	2,121
Deferred tax assets, gross	23,869	35,391
Deferred tax liabilities:
Depreciation	(270)	(336)
Partnerships — CRA-purposed private equity funds	(941)	(1,697)
Fair value mark on subordinated debt	(743)	(1,303)
Other	(1,675)	(2,824)
Deferred tax liabilities, gross	(3,629)	(6,160)
Net deferred tax asset	$ 20,240	$ 29,231

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Effective Income Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Federal statutory rate times financial statement income	$ 54,325	$ 52,823	$ 38,105
Effect of:
State taxes, net of federal benefit	239	267	37
Bank-owned life insurance income	(423)	(436)	(419)
Municipal interest income	(978)	(1,041)	(1,025)
ESOP shares released	541	757	1,207
Restricted stock and stock options	(1,578)	0	0
Sale of LegacyTexas Insurance Services, Inc.	0	640	0
DTA write-down due to the Tax Cuts and Jobs Act	13,493	0	0
Other	100	92	51
Total income tax expense	$ 65,719	$ 53,102	$ 37,956
Effective Tax Rate before deferred tax write-down	33.65%	35.18%	34.86%
Effective Tax Rate	42.34%	35.18%	34.86%

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Loans, Related Parties
Beginning balance	$ 15,337
New loans	0
Effect of changes in composition of related parties	0
Repayments	(933)
Ending balance	14,404
Related party deposits	$ 39,615	$ 48,761

Regulatory Capital Matters (Det

Regulatory Capital Matters (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Company
Total risk-based capital
Actual, Amount	$ 991,713	$ 910,040
Actual, Ratio	11.87%	11.71%
Required for Capital Adequacy Purposes, Amount	$ 668,142	$ 621,870
Required for Capital Adequacy Purposes, Ratio	8.00%	8.00%
To Be Well-Capitalized, Amount	$ 835,178	$ 777,338
To Be Well-Capitalized, Ratio	10.00%	10.00%
Tier 1 risk-based capital
Actual, Amount	$ 796,887	$ 721,600
Actual, Ratio	9.54%	9.28%
Required for Capital Adequacy Purposes, Amount	$ 501,107	$ 466,403
Required for Capital Adequacy Purposes, Ratio	6.00%	6.00%
To Be Well-Capitalized, Amount	$ 501,107	$ 466,403
To Be Well-Capitalized, Ratio	6.00%	6.00%
Common equity tier 1 risk-based capital
Actual, Amount	$ 784,960	$ 709,858
Actual, Ratio	9.40%	9.13%
Required for Capital Adequacy Purposes, Amount	$ 375,830	$ 349,802
Required for Capital Adequacy Purposes, Ratio	4.50%	4.50%
Tier 1 leverage
Actual, Amount	$ 796,887	$ 721,600
Actual, Ratio	9.17%	8.73%
Required for Capital Adequacy Purposes, Amount	$ 347,731	$ 330,782
Required for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Bank
Total risk-based capital
Actual, Amount	$ 939,655	$ 869,523
Actual, Ratio	11.25%	11.19%
Required for Capital Adequacy Purposes, Amount	$ 668,096	$ 621,840
Required for Capital Adequacy Purposes, Ratio	8.00%	8.00%
To Be Well-Capitalized, Amount	$ 835,120	$ 777,300
To Be Well-Capitalized, Ratio	10.00%	10.00%
Tier 1 risk-based capital
Actual, Amount	$ 867,424	$ 803,374
Actual, Ratio	10.39%	10.34%
Required for Capital Adequacy Purposes, Amount	$ 501,072	$ 466,380
Required for Capital Adequacy Purposes, Ratio	6.00%	6.00%
To Be Well-Capitalized, Amount	$ 668,096	$ 621,840
To Be Well-Capitalized, Ratio	8.00%	8.00%
Common equity tier 1 risk-based capital
Actual, Amount	$ 867,424	$ 803,374
Actual, Ratio	10.39%	10.34%
Required for Capital Adequacy Purposes, Amount	$ 375,804	$ 349,785
Required for Capital Adequacy Purposes, Ratio	4.50%	4.50%
To Be Well-Capitalized, Amount	$ 542,828	$ 505,245
To Be Well-Capitalized, Ratio	6.50%	6.50%
Tier 1 leverage
Actual, Amount	$ 867,424	$ 803,374
Actual, Ratio	9.98%	9.71%
Required for Capital Adequacy Purposes, Amount	$ 347,808	$ 330,873
Required for Capital Adequacy Purposes, Ratio	4.00%	4.00%
To Be Well-Capitalized, Amount	$ 434,759	$ 413,591
To Be Well-Capitalized, Ratio	5.00%	5.00%

Commitments and Contingent L100

Commitments and Contingent Liabilities - Off-Balance Sheet Agreements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Commitments [Line Items]
Total unused commitments/capacity	$ 2,373,297	$ 2,564,385
Unused capacity on Warehouse Purchase Program loans
Other Commitments [Line Items]
Total unused commitments/capacity	738,412	892,659
Unused commitments to extend credit
Other Commitments [Line Items]
Total unused commitments/capacity	1,600,794	1,642,528
Unused lines of credit | Standby letters of credit
Other Commitments [Line Items]
Total unused commitments/capacity	$ 34,091	$ 29,198

Commitments and Contingent L101

Commitments and Contingent Liabilities - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Commitments [Line Items]
Overdraft protection	$ 84,727	$ 85,709
Unfunded commitments	1,680
Investment in Community Reinvestment Act private equity funds	$ 11,223
Investment in Community Reinvestment Act private equity funds, ownership	6.20%
Other liabilities
Other Commitments [Line Items]
Mortgage repurchase liability	$ 131	143
Reserve for off-balance sheet activities | Other liabilities
Other Commitments [Line Items]
Valuation reserves	929	1,573
Financial guarantee
Other Commitments [Line Items]
Credit card guarantees	5,257	$ 3,335
FHLB letters of credit
Other Commitments [Line Items]
Loans pledged as collateral	$ 944,370

Parent Company Only Condense102

Parent Company Only Condensed Financial Information - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Cash on deposit at subsidiary	$ 61,713	$ 59,823
Total assets	9,086,196	8,362,255
LIABILITIES AND SHAREHOLDERS’ EQUITY
Subordinated debt	134,522	134,032
Other liabilities	96,278	57,009
Stockholders' Equity Attributable to Parent	959,874	885,365	$ 804,076	$ 568,223
Total liabilities and shareholders’ equity	9,086,196	8,362,255
Parent Company
ASSETS
Cash on deposit at subsidiary	26,692	16,962
Investment in banking subsidiary	1,042,338	978,880
Receivable from banking subsidiary	12,278	10,317
ESOP note receivable and other assets	13,814	13,999
Total assets	1,095,122	1,020,158
LIABILITIES AND SHAREHOLDERS’ EQUITY
Subordinated debt	134,522	134,032
Other liabilities	726	761
Total liabilities and shareholders’ equity	$ 1,095,122	$ 1,020,158

Parent Company Only Condense103

Parent Company Only Condensed Financial Information - 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
Condensed Financial Statements, Captions [Line Items]
Interest expense	$ 15,912	$ 15,499	$ 13,027	$ 10,988	$ 10,413	$ 9,431	$ 7,982	$ 7,257	$ 55,426	$ 35,083	$ 21,615
Income before income tax expense									155,213	150,923	108,872
Income tax benefit									(65,719)	(53,102)	(37,956)
Net income									89,494	97,821	70,916
Parent Company
Condensed Financial Statements, Captions [Line Items]
Cash dividends from subsidiary									35,000	0	24,500
Excess of earnings over dividend from subsidiary									61,341	103,572	48,677
Interest income on ESOP loan									449	487	565
Interest income on subordinated debt									13	11	17
Other income									0	0	5
Gross income before expenses									96,803	104,070	73,764
Interest expense									7,819	6,040	1,046
Operating expenses									3,754	3,236	3,009
Income before income tax expense									85,230	94,794	69,709
Income tax benefit									4,264	3,027	1,207
Net income									$ 89,494	$ 97,821	$ 70,916

Parent Company Only Condense104

Parent Company Only Condensed Financial Information - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities
Net income	$ 89,494	$ 97,821	$ 70,916
Adjustments to reconcile net income to net cash from operating activities:
Net change in other assets	(1,299)	(2,947)	8,444
Net change in other liabilities	40,176	5,913	(16,250)
Net cash provided by operating activities	189,016	132,448	89,202
Cash flows from investing activities
Cash received in excess of cash paid for acquisition of LegacyTexas Group, Inc.	0	0	128,598
Net cash (used in) investing activities	(769,880)	(1,019,429)	(1,131,445)
Cash flows from financing activities
Repayments of borrowings	(2,015)	(24,929)	(32,953)
Share repurchase	0	0	(7,989)
Payment of dividends	(29,277)	(27,676)	(25,747)
Net cash provided by financing activities	585,108	560,554	1,525,861
Net change in cash and cash equivalents	4,244	(326,427)	483,618
Beginning cash and cash equivalents	289,212	615,639	132,021
Ending cash and cash equivalents	293,456	289,212	615,639
Parent Company
Cash flows from operating activities
Net income	89,494	97,821	70,916
Adjustments to reconcile net income to net cash from operating activities:
Excess of earnings over dividend from subsidiary	(61,341)	(103,572)	(48,677)
Amortization	490	530	171
Activity in share-based compensation plans	5,501	3,152	3,068
Net change in other assets	(207)	(481)	6,931
Net change in other liabilities	(35)	(38)	(14,544)
Net cash provided by operating activities	33,902	(2,588)	17,865
Cash flows from investing activities
Capital contribution (to) from subsidiary	0	(49,000)	(40,000)
Cash received in excess of cash paid for acquisition of LegacyTexas Group, Inc.	0	0	201
Payments received on ESOP notes receivable	393	981	1,495
Net cash (used in) investing activities	393	(48,019)	(38,304)
Cash flows from financing activities
Proceeds from borrowings	0	73,439	73,407
Repayments of borrowings	0	(24,929)	(24,364)
Share repurchase	0	0	(7,989)
Net issuance of common stock under employee stock plans	4,712	3,755	1,284
Payment of dividends	(29,277)	(27,676)	(25,747)
Net cash provided by financing activities	(24,565)	24,589	16,591
Net change in cash and cash equivalents	9,730	(26,018)	(3,848)
Beginning cash and cash equivalents	16,962	42,980	46,828
Ending cash and cash equivalents	$ 26,692	$ 16,962	$ 42,980

Quarterly Financial Data (Un105

Quarterly Financial Data (Unaudited) (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
Loans and Leases Receivable Disclosure [Line Items]
Interest Income	$ 96,111	$ 94,463	$ 88,747	$ 87,536	$ 84,497	$ 82,911	$ 77,336	$ 72,608	$ 366,857	$ 317,352	$ 262,692
Interest Expense	15,912	15,499	13,027	10,988	10,413	9,431	7,982	7,257	55,426	35,083	21,615
Net interest income	80,199	78,964	75,720	76,548	74,084	73,480	69,354	65,351	311,431	282,269	241,077
Provision for Credit Losses	3,743	7,157	6,255	22,301	7,833	3,467	6,800	8,800	$ 40,100	$ 25,400	$ 25,465
Securities Gains and (Losses)	0	(20)	0	(19)	(6)	(3)	65	0
Net Income	$ 14,660	$ 28,709	$ 27,935	$ 18,190	$ 25,305	$ 27,217	$ 23,217	$ 22,082
Basic earnings per common share (in dollars per share)	$ 0.31	$ 0.61	$ 0.60	$ 0.39	$ 0.54	$ 0.59	$ 0.50	$ 0.48	$ 1.91	$ 2.11	$ 1.54
Diluted earnings per common share (in dollars per share)	$ 0.31	$ 0.61	$ 0.59	$ 0.38	$ 0.54	$ 0.58	$ 0.50	$ 0.48	$ 1.89	$ 2.09	$ 1.53
Charge-off									$ 34,742	$ 8,859	$ 4,707
Income tax adjustment to deferred tax asset related to the Tax Cuts and Jobs Act									13,493	0	0
Commercial and industrial
Loans and Leases Receivable Disclosure [Line Items]
Provision for Credit Losses									35,982	17,763	18,790
Charge-off									32,846	$ 7,746	$ 3,129
Commercial and industrial | Healthcare Finance Relationship
Loans and Leases Receivable Disclosure [Line Items]
Charge-off									$ 16,360