FCB Financial 10-K 23 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. 01, 2018	Jun. 30, 2017
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	FCB
Entity Registrant Name	FCB FINANCIAL HOLDINGS, INC.
Entity Central Index Key	1,476,651
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 2,000
Class A common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		44,723,757
Class B common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		0

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Cash and due from banks	$ 60,787	$ 52,903
Interest-earning deposits in other banks	55,134	30,973
Investment securities:
Available for sale securities, at fair value	2,120,803	1,876,434
Federal Home Loan Bank and other bank stock, at cost	56,881	51,656
Total investment securities	2,177,684	1,928,090
Loans held for sale	12,736	20,220
Loans:
Loans	7,977,784	6,634,894
Allowance for loan losses	(47,145)	(37,897)
Loans, net	7,930,639	6,596,997
Premises and equipment, net	36,144	36,652
Other real estate owned	14,906	19,228
Goodwill	81,204	81,204
Core deposit intangible	3,668	4,691
Deferred tax assets, net	27,043	61,391
Bank-owned life insurance	201,069	198,438
Other assets	76,065	59,347
Total assets	10,677,079	9,090,134
Transaction accounts:
Noninterest-bearing	1,236,685	905,905
Interest-bearing	4,830,525	4,183,972
Total transaction accounts	6,067,210	5,089,877
Time deposits	2,606,717	2,215,794
Total deposits	8,673,927	7,305,671
Borrowings (including FHLB advances of $670,000 and $592,250, respectively)	749,113	751,103
Other liabilities	74,867	50,919
Total liabilities	9,497,907	8,107,693
Commitments and contingencies (Note 17)
Stockholders’ Equity:
Additional paid-in capital	933,960	875,314
Retained earnings	313,645	188,451
Accumulated other comprehensive income (loss)	8,893	(3,995)
Treasury stock, at cost; 2,694,489, 2,694,489 Class A and 192,132, 192,132 Class B common shares	(77,373)	(77,373)
Total stockholders’ equity	1,179,172	982,441
Total liabilities and stockholders’ equity	10,677,079	9,090,134
Class A common stock
Stockholders’ Equity:
Common stock	47	44
Class B common stock
Stockholders’ Equity:
Common stock	0	0
Acquired loans portfolio segment
Loans:
Loans	316,399	375,488
Allowance for loan losses	(1,131)	(1,410)
New loans portfolio segment
Loans:
Loans	7,661,385	6,259,406
Allowance for loan losses	$ (42,625)	$ (33,543)

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
FHLB advances	$ 670,000	$ 592,250
Treasury stock, shares (in shares)		2,886,621
Class A common stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	47,065,593	43,663,586
Common stock, shares outstanding (in shares)	44,371,104	40,969,097
Treasury stock, shares (in shares)	2,694,489	2,694,489
Class B common stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	192,132	380,606
Common stock, shares outstanding (in shares)	0	197,950
Treasury stock, shares (in shares)	192,132	192,132

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income:
Interest and fees on loans	$ 295,400	$ 258,261	$ 196,123
Interest and dividends on investment securities	78,176	60,706	52,741
Other interest income	525	349	176
Total interest income	374,101	319,316	249,040
Interest expense:
Interest on deposits	66,066	44,329	26,141
Interest on borrowings	12,583	7,271	5,103
Total interest expense	78,649	51,600	31,244
Net interest income	295,452	267,716	217,796
Provision for loan losses	9,415	7,655	6,823
Net interest income after provision for loan losses	286,037	260,061	210,973
Noninterest income:
Service charges and fees	3,736	3,467	3,184
Loan and other fees	11,415	8,895	8,611
Bank-owned life insurance income	5,647	5,192	4,610
FDIC loss share indemnification loss	0	0	(65,529)
Income from resolution of acquired assets	1,973	3,345	9,605
Gain (loss) on sales of other real estate owned	(176)	3,126	8,107
Gain on investment securities	1,933	1,819	1,906
Other noninterest income	10,488	3,873	4,184
Total noninterest income (loss)	35,016	29,717	(25,322)
Noninterest expense:
Salaries and employee benefits	84,830	76,231	69,021
Occupancy and equipment expenses	13,463	13,591	14,397
Loan and other real estate related expenses	3,623	7,356	7,740
Professional services	5,940	5,207	5,412
Data processing and network	12,565	11,461	10,671
Regulatory assessments and insurance	8,971	7,872	8,196
Amortization of intangibles	1,023	1,189	1,631
Marketing and promotions	4,587	3,851	3,612
Other operating expenses	6,692	7,199	5,924
Total noninterest expense	141,694	133,957	126,604
Income before income tax expense	179,359	155,821	59,047
Income tax expense	54,165	55,905	5,656
Net income	$ 125,194	$ 99,916	$ 53,391
Earnings per share:
Basic earnings per share (in dollars per shares)	$ 2.92	$ 2.45	$ 1.29
Diluted earnings per share (in dollars per shares)	$ 2.71	$ 2.31	$ 1.23
Weighted average shares outstanding:
Weighted average number of common shares—basic	42,887,142	40,716,588	41,300,979
Weighted average number of common shares—diluted	46,120,930	43,225,164	43,293,607

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - 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
Statement of Comprehensive Income [Abstract]
Net income	$ 18,964	$ 32,160	$ 35,081	$ 38,989	$ 27,896	$ 26,064	$ 23,504	$ 22,452	$ 125,194	$ 99,916	$ 53,391
Other comprehensive income (loss):
Unrealized net holding gains (losses) on investment securities available for sale, net of taxes of $(9,244), $(4,467), and $5,399, respectively									14,868	7,115	(8,598)
Reclassification adjustment for realized (gains) losses on investment securities available for sale included in net income, net of taxes of $1,226, $1,048, and $956, respectively									(1,980)	(1,667)	(1,524)
Total other comprehensive income (loss)									12,888	5,448	(10,122)
Total comprehensive income									$ 138,082	$ 105,364	$ 43,269

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Additional Paid in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (loss)	Class A common stock	Class A common stockCommon Stock	Class B common stock	Class B common stockCommon Stock
Beginning balance at Dec. 31, 2014	$ 851,653	$ 834,538	$ 35,144	$ (18,751)	$ 679		$ 36		$ 7
Beginning balance (in shares) at Dec. 31, 2014							34,469,650		6,940,048
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	53,391		53,391
Exchange of B shares to A shares							$ 3		$ (3)
Exchange of B shares to A shares (in shares)							3,206,166		(3,206,166)
Stock-based compensation and warrant expense	5,290	5,290
Excess tax benefit of stock-based compensation	2,048	2,048
Treasury stock purchases	(34,884)			(34,884)
Treasury stock purchases (in shares)							(1,050,062)
Stock issued in connection with equity awards and warrants	8,793	8,793
Stock issued in connection with equity awards and warrants (in shares)							500,817
Other	(60)	(60)
Other comprehensive income (loss)	(10,122)				(10,122)
Ending balance at Dec. 31, 2015	876,109	850,609	88,535	(53,635)	(9,443)		$ 39		$ 4
Ending balance (in shares) at Dec. 31, 2015							37,126,571		3,733,882
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 99,916		99,916
Exchange of B shares to A shares							$ 4		$ (4)
Exchange of B shares to A shares (in shares)	3,545,408						3,545,408	3,545,408	(3,545,408)
Stock-based compensation and warrant expense	$ 5,613	5,613
Excess tax benefit of stock-based compensation	2,110	2,110
Treasury stock purchases	(23,738)			(23,738)		$ (23,700)
Treasury stock purchases (in shares)						(717,115)	(717,115)
Stock issued in connection with equity awards and warrants	17,042	17,041					$ 1
Stock issued in connection with equity awards and warrants (in shares)							1,014,233
Other	(59)	(59)
Other comprehensive income (loss)	5,448				5,448
Ending balance at Dec. 31, 2016	982,441	875,314	188,451	(77,373)	(3,995)		$ 44		$ 0
Ending balance (in shares) at Dec. 31, 2016						40,969,097	40,969,097	197,950	188,474
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 125,194		125,194
Exchange of B shares to A shares (in shares)	188,474						188,474	(188,474)	(188,474)
Stock-based compensation and warrant expense	$ 8,038	8,038
Treasury stock purchases (in shares)						0
Stock issued in connection with equity awards and warrants	50,670	50,667					$ 3
Stock issued in connection with equity awards and warrants (in shares)							3,213,533
Other	(59)	(59)
Other comprehensive income (loss)	12,888				12,888
Ending balance at Dec. 31, 2017	$ 1,179,172	$ 933,960	$ 313,645	$ (77,373)	$ 8,893		$ 47		$ 0
Ending balance (in shares) at Dec. 31, 2017						44,371,104	44,371,104	0	0

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	$ 125,194	$ 99,916	$ 53,391
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provision for loan losses	9,415	7,655	6,823
Amortization of intangible assets	1,023	1,189	1,631
Depreciation and amortization of premises and equipment	3,618	3,583	3,792
Amortization of discount on loans	(1,265)	(930)	(2,657)
Net amortization (accretion) of premium (discount) on investment securities	2,166	1,586	1,883
Net amortization (accretion) of premium (discount) on time deposits	0	(50)	(336)
Net amortization (accretion) of premium (discount) on FHLB advances and other borrowings	(846)	(2,635)	(2,609)
Impairment of other real estate owned	670	1,751	728
Impairment of fixed assets HFS	0	48	0
FDIC Loss share indemnification loss	0	0	65,529
(Gain) loss on investment securities	(1,933)	(1,819)	(1,906)
(Gain) loss on sale of loans	(4,860)	(1,635)	(1,717)
(Gain) loss on sale of other real estate owned	176	(3,126)	(8,107)
(Gain) loss on sale of premises and equipment	(34)	48	174
Deferred tax expense	26,329	10,364	(21,395)
Stock-based compensation	8,038	5,613	5,290
Increase in cash surrender value of BOLI	(5,647)	(5,192)	(4,610)
Net change in operating assets and liabilities:
Net change in loans held for sale	9,535	(16,071)	(379)
Settlement of FDIC loss share agreement	0	0	(14,815)
Net change in other assets	(14,112)	8,499	49
Net change in other liabilities	6,679	(10,717)	(12,539)
Net cash provided by (used in) operating activities	164,146	98,077	68,220
Cash Flows From Investing Activities:
Purchase of investment securities available for sale	(884,732)	(750,482)	(676,708)
Sales of investment securities available for sale	223,726	342,137	354,733
Paydown and maturities of investment securities available for sale	451,974	89,421	139,996
Purchase of FHLB and other bank stock	(178,578)	(113,362)	(81,207)
Sales of FHLB and other bank stock	173,353	121,183	88,621
Net change in loans	(1,601,014)	(1,357,875)	(939,514)
Purchase of loans	(11,867)	(200,480)	(395,649)
Proceeds from sale of loans	271,854	106,450	52,362
Purchase of bank-owned life insurance	0	(25,000)	(25,000)
Proceeds from sale of other real estate owned	5,520	34,274	64,139
Purchase of premises and equipment	(3,163)	(4,925)	(1,958)
Proceeds from the sale of premises and equipment	87	1,548	0
Capitalized expenditures on foreclosed real estate	0	(543)	0
Proceeds from life insurance	3,016	0	1,193
Net cash provided by (used in) investing activities	(1,549,824)	(1,757,654)	(1,418,992)
Cash Flows From Financing Activities:
Net change in deposits	1,368,256	1,875,083	1,452,439
Net change in FHLB advances and other borrowings	77,750	(214,250)	(177,186)
Net change in repurchase agreements	(78,894)	(15,195)	94,997
Repurchase of stock	0	(23,738)	(34,884)
Exercise of stock options	50,670	17,042	8,793
Excess tax benefit from share based payments	0	2,110	2,048
Other financing costs	(59)	(59)	(60)
Net cash provided by (used in) financing activities	1,417,723	1,640,993	1,346,147
Net Change in Cash and Cash Equivalents	32,045	(18,584)	(4,625)
Cash and Cash Equivalents at Beginning of Period	83,876	102,460	107,085
Cash and Cash Equivalents at End of Period	115,921	83,876	102,460
Supplemental Disclosures of Cash Flow Information:
Interest paid	77,859	50,631	30,788
Income taxes paid	19,719	60,192	36,304
Supplemental disclosure of noncash investing and financing activities:
Transfer of loans to other real estate owned	$ 2,044	$ 12,244	$ 21,573

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 FCB Financial Holdings, Inc. (the “Company”) is a national bank holding company with one wholly-owned national bank subsidiary, Florida Community Bank, N.A. (“Florida Community Bank” or the “Bank”), headquartered in Weston, Florida, offering a comprehensive range of traditional banking products and services to individual and corporate customers through 46 banking centers located in Florida at December 31, 2017 . Principles of Consolidation The consolidated financial statements include the accounts of the Company, its wholly-owned subsidiary, the Bank, and the Bank’s subsidiaries, which consist of a group of real estate holding companies. Intercompany transactions and balances have been eliminated in consolidation. Use of Estimates The Company’s financial reporting and accounting policies conform to U.S. GAAP. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates subject to significant change include the allowance for loan losses, valuation of and accounting for acquired loans, the carrying value of OREO, the fair value of financial instruments, the valuation of goodwill and other intangible assets, acquisition-related fair value computations, stock-based compensation and deferred taxes. Business combinations The Company accounts for transactions that meet the definition of a purchase business combination by recording the assets acquired and liabilities assumed at their fair value upon acquisition. The operations of the acquisitions are included in the consolidated financial statements from the date of acquisition. Intangible assets, indemnification contracts and contingent consideration are identified and recognized individually. If the fair value of the assets acquired exceeds the purchase price plus the fair value of the liabilities assumed, a bargain purchase gain is recognized. Conversely, if the purchase price plus the fair value of the liabilities assumed exceeds the fair value of the assets acquired, goodwill is recognized. The Company’s assumptions utilized to determine the fair value of assets acquired and liabilities assumed conform to market conditions at the date of acquisition. The provisional amounts recorded are updated if better information is obtained about the initial assumptions used to determine fair value or if new information is obtained regarding the facts and circumstances that existed at the date of acquisition. The provisional amounts may be adjusted through the completion of the measurement period, which does not exceed one year from the date of acquisition. Fair Value Measurement The Company uses estimates of fair value in applying various accounting standards for its consolidated financial statements on either a recurring or non-recurring basis. Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between willing and able market participants. The Company groups its assets and liabilities measured at fair value in three hierarchy levels, based on the observability and transparency of the inputs. These levels are as follows: Level 1—Unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets or liabilities; Level 2—Observable inputs other than level 1 inputs, including quoted prices for similar assets and liabilities, quoted prices for identical assets and liabilities in less active markets and other inputs that can be corroborated by observable market data; Level 3—Unobservable inputs supported by limited or no market activity or data and inputs requiring significant management judgment or estimation; valuation techniques utilizing level 3 inputs include option pricing models, discounted cash flow models and similar techniques. It is the Company’s policy to maximize the use of observable inputs and minimize the use of unobservable inputs in estimating fair value. Unobservable inputs are utilized in determining fair value estimates only to the extent that observable inputs are not available. The need to use unobservable inputs generally results from a lack of market liquidity and trading volume. Transfers between levels of fair value hierarchy are recorded at the end of the reporting period. Accounting Standards Codification (“ASC”) Topic 825, Financial Instruments, allows the Company an irrevocable option for measurement of eligible financial assets or financial liabilities at fair value on an instrument by instrument basis (the fair value option). An election may be made at the time an eligible financial asset, financial liability or firm commitment is recognized or when certain specified reconsideration events occur. The Company has not elected the fair value option for any eligible financial instrument as of December 31, 2017 or 2016 . Transfers of Financial Assets Transfers of financial assets are accounted for as sales, when control over the assets has been surrendered. A gain or loss is recognized in earnings upon completion of the sale based on the difference between the sales proceeds and the carrying value of the assets. Control over the transferred assets is deemed to have been surrendered when the assets have been isolated from the Company, the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets and the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. Cash and Cash Equivalents Cash and cash equivalents include cash and due from banks, interest-bearing deposits with banks, Federal funds sold and securities purchased under resale agreements or similar arrangements. Cash and cash equivalents have original maturities of three months or less . Accordingly, the carrying amount of such instruments is considered a reasonable estimate of fair value. Restrictions on Cash The Bank is required to maintain reserve balances with the FRB. Such reserve requirements are based on a percentage of deposit liabilities and may be satisfied by cash on hand or on deposit. Because the amount of cash on hand exceeded the requirement, there was no reserve with the FRB as of December 31, 2017 or 2016 . Investment Securities Securities transactions are recorded on the trade date basis. The Company determines the classification of investment securities at the time of purchase. If the Company has the intent and the ability at the time of purchase to hold debt securities until maturity, they are classified as held-to-maturity. Investment securities held-to-maturity are stated at amortized cost. Debt securities the Company does not intend to hold to maturity are classified as available for sale and carried at estimated fair value with unrealized gains or losses reported as a separate component of stockholders’ equity in accumulated other comprehensive income, net of applicable income taxes. Available for sale securities are a part of the Company’s asset/liability management strategy and may be sold in response to changes in interest rates, prepayment risk or other market factors. Interest income and dividends on securities are recognized in interest income on an accrual basis. Premiums and discounts on debt securities are amortized as an adjustment to interest income over the period to maturity of the related security using the effective interest method. Realized gains or losses on the sale of securities are determined using the specific identification method. The Company reviews investment securities for impairment on a quarterly basis or more frequently if events and circumstances warrant. In order to determine if a decline in fair value below amortized cost represents other-than-temporary impairment ("OTTI"), management considers several factors, including but not limited to, the length of time and extent to which the fair value has been less than the amortized cost basis, the financial condition and near-term prospects of the issuer (considering factors such as adverse conditions specific to the issuer and the security and ratings agency actions) and the Company’s intent and ability to retain the investment in order to allow for an anticipated recovery in fair value. The Company recognizes OTTI of a debt security for which there has been a decline in fair value below amortized cost if (i) management intends to sell the security, (ii) it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis, or (iii) the Company does not expect to recover the entire amortized cost basis of the security. The amount by which amortized cost exceeds the fair value of a debt security that is considered to have OTTI is separated into a component representing the credit loss, which is recognized in earnings, and a component related to all other factors, which is recognized in other comprehensive income. The measurement of the credit loss component is equal to the difference between the debt security’s amortized cost basis and the present value of its expected future cash flows discounted at the security’s effective yield. If the Company intends to sell the security, or if it is more likely than not it will be required to sell the security before recovery, an OTTI write-down is recognized in earnings equal to the entire difference between the amortized cost basis and fair value of the security. The Bank, as a member of the FHLB is required to maintain an investment in the stock of the FHLB. No market exists for this stock, and the Bank’s investment can be liquidated only through redemption by the FHLB, at the discretion of and subject to conditions imposed by the FHLB. Historically, FHLB stock redemptions have been at cost (par value), which equals the Company’s carrying value. The Company monitors its investment in FHLB stock for impairment through review of recent financial results of the FHLB including capital adequacy and liquidity position, dividend payment history, redemption history and information from credit agencies. The Company has not identified any indicators of impairment of FHLB stock. Loans The Company’s accounting methods for loans differ depending on whether the loans are new (“New” loans) or acquired (“Acquired” loans), and for acquired loans, whether the loans were acquired at a discount as a result of credit deterioration since the date of origination. New Loans The Company accounts for originated loans and purchased loans not acquired through business acquisitions as New loans. New loans that management has the intent and ability to hold for the foreseeable future are reported at their outstanding principal balances net of any allowance for loan losses, unamortized deferred fees and costs and unamortized premiums or discounts. The net amount of nonrefundable loan origination fees and certain direct costs associated with the lending process are deferred and amortized into interest income over the contractual lives of the New loans using methods which approximate the effective yield method. Discounts and premiums are amortized or accreted into interest income over the estimated term of the New loans using methods that approximate the effective yield method. Interest income on New loans is accrued based on the unpaid principal balance outstanding and the contractual terms of the loan agreements. Acquired Loans Acquired loans are accounted for under ASC 310-30 unless the loan type is excluded from the scope of ASC 310-30 (i.e. loans where borrowers have revolving privileges at acquisition date, or “Non-ASC 310-30” loans). The Company has elected to account for loans acquired with deteriorated credit quality since origination under ASC 310-30 (“ASC 310-30” loans or pools) due to the following: • There is evidence of credit quality deterioration since origination resulting in a “Day 1” discount attributable, at least in part, to credit quality; • The loans were acquired in a business combination or asset purchase; and • The loans are not to be subsequently accounted for at fair value. The Company has elected this policy for loans acquired through business combinations exhibiting credit deterioration since origination, except those loan types which have been scoped out of ASC 310-30. Substantially all loans acquired through the FDIC-assisted acquisitions had a fair value discount at acquisition date due at least in part to deterioration in credit quality since origination. However, there was a separate grouping of loans individually identified with substantial credit impairment that would be explicitly scoped into ASC 310-30 from those that were classified by analogy. The Company determined that a loan would be explicitly scoped into ASC 310-30 if there was evidence of credit deterioration at Day 1 and that it was probable that the Company would be unable to collect all contractual cash flows receivable. The loans that were classified by analogy were determined to have evidence of credit deterioration at Day 1 and that it was possible, not probable, that the Company would be unable to collect all contractual cash flows receivable. For each acquisition, ASC 310-30 loans are aggregated into pools based on common risk characteristics, which includes similar credit risk of the loans based on whether loans were analogized or were explicitly scoped into ASC 310-30, internal risk ratings for commercial real estate, land and development and commercial loans; and performing status for consumer and single family residential loans. Pools of loans are further aggregated by collateral type (e.g. commercial real estate, single family residential, etc.). The Company did not elect to aggregate loans into pools that were acquired from separate acquisitions completed in the same fiscal quarter. Acquired loans are recorded at their fair value at the acquisition date. Fair value for acquired loans is based on a discounted cash flow methodology that considers factors including the type of loan and related collateral type, delinquency and credit classification status, fixed or variable interest rate, term of loan, whether or not the loan was amortizing, and current discount rates. Additional assumptions used include default rates, loss severity, loss curves and prepayment speeds. Discounts due to credit quality are included in the determination of fair value; therefore an allowance for loan losses is not recorded at the acquisition date. The discount rates used for the cash flow methodology are based on market rates for new originations of comparable loans at the time of acquisition and include adjustments for liquidity concerns. The fair value is determined from the discounted cash flows for each individual loan, and for ASC 310-30 loans are then aggregated at the unit of account, or pool level. For acquired loans with deteriorated credit quality, the Company makes an estimate of the total cash flows it expects to collect from the loans in each pool, which includes undiscounted expected principal and interest as well as cash received through other forms of satisfaction (e.g. foreclosure). The excess of contractual amounts over the total cash flows expected to be collected from the loans is referred to as non-accretable difference, which is not accreted into income. The excess of the expected undiscounted cash flows over the carrying value of the loans is referred to as accretable discount. Accretable discount is recognized as interest income on a level-yield basis over the expected term of the loans in each pool. The Company continues to estimate cash flows expected to be collected over the expected term of the ASC 310-30 loans on a quarterly basis. Subsequent increases in total cash flows expected to be collected are recognized as an adjustment to the accretable discount with the amount of periodic accretion adjusted over the remaining expected term of the loans. Subsequent decreases in cash flows expected to be collected over the expected term of the loans are recognized as impairment in the current period through a provision for loan losses. Each pool is accounted for as a single asset with a single composite interest rate and an aggregate expectation of cash flows. Resolutions of loans may include sales to third parties, receipt of payments in settlement with the borrower, or foreclosure of the collateral. Upon these resolutions, the Company’s policy is to remove an individual ASC 310-30 loan from a pool based on comparing the amount received from its resolution with its contractual amount. Any difference between these amounts is absorbed by the nonaccretable difference. This removal method assumes that the amount received from these resolutions approximates the pool performance expectations of cash flows. The accretable yield percentage is unaffected by the resolution. Any changes in the effective yield for the remaining loans in the pool are addressed by the quarterly cash flow evaluation process for each pool. For loans that are resolved by payment in full, there is no release of the nonaccretable difference for the pool because there is no difference between the amount received at resolution and the contractual amount of the loan. Payments received in excess of expected cash flows may result in an ASC 310-30 pool becoming fully amortized and its carrying value reduced to zero even though outstanding contractual balances remain related to loans in the pool. Once the carrying value of an ASC 310-30 pool is reduced to zero, any future proceeds from the borrower or from the sale of loans are recognized as interest income upon receipt. There were six ASC 310-30 pools whose carrying value had been reduced to zero as of December 31, 2017 . These pools had an aggregate Unpaid Principal Balance (“UPB” or “UPBs”) of $399 thousand as of December 31, 2017 . For the year ended December 31, 2017 , the Company sold approximately $11.7 million of loans accounted for under ASC 310-30. These sales resulted in proceeds that exceeded the carrying value of the accounting pool in which the loans resided of $3.3 million which was recognized as interest income. There were six ASC 310-30 pools whose carrying value had been reduced to zero as of December 31, 2016 . These pools had an aggregate UPB of $456 thousand as of December 31, 2016 . For the year ended December 31, 2016 , the Company sold approximately $75.3 million of loans accounted for under ASC 310-30. These sales resulted in proceeds that exceeded the carrying value of the accounting pool in which the loans resided of $27.2 million which was recognized as interest income. Non-ASC 310-30 loans are recorded at their estimated fair value as of the acquisition date and subsequently accounted for under ASC Topic 310-20, Receivables—Nonrefundable Fees and Other Costs (“ASC 310-20”). The fair value discount is accreted using methods which approximate the level-yield method over the remaining term of the loans and is recognized as a component of interest income. Loans Held for Sale Certain residential fixed rate and adjustable rate mortgage loans originated by the Company with the intent to sell in the secondary market are carried at the lower of cost or fair value, as determined by outstanding commitments from investors or prevailing market prices. These loans are generally sold on a non-recourse basis with servicing released. Gains and losses on the sale of loans recognized in earnings are measured based on the difference between proceeds received and the carrying amount of the loans, inclusive of deferred origination fees and costs, if any. Nonaccrual Loans For New and Non-ASC 310-30 loans, the Company classifies loans as past due when the payment of principal or interest is greater than 30 days delinquent based on the contractual next payment due date. The Company’s policies related to when loans are placed on nonaccrual status conform to guidelines prescribed by regulatory authorities. Loans are placed on nonaccrual status when it is probable that principal or interest is not fully collectible, or generally when principal or interest becomes 90 days past due, whichever occurs first. Loans secured by 1-4 single family residential properties may remain in accruing status until they are 180 days past due if management determines that it does not have concern over the collectability of principal and interest because the loan is adequately collateralized and in the process of collection. When loans are placed on nonaccrual status, interest receivable is reversed against interest income in the current period and amortization of any discount ceases. Interest payments received thereafter are applied as a reduction to the remaining principal balance unless management believes that the ultimate collection of the principal is likely, in which case payments are recognized in earnings on a cash basis. Loans are removed from nonaccrual status when they become current as to both principal and interest and the collectability of principal and interest is no longer doubtful. Generally, a nonaccrual loan that is restructured remains on nonaccrual for a period of six months to demonstrate the borrower can meet the restructured terms. However, performance prior to the restructuring, or significant events that coincide with the restructuring, are considered in assessing whether the borrower can meet the new terms and may result in the loan being returned to accrual status after a shorter performance period. If the borrower’s ability to meet the revised payment schedule is not reasonably assured, the loan remains classified as a nonaccrual loan. Contractually delinquent ASC 310-30 loans are not classified as nonaccrual as long as the discount continues to be accreted on the corresponding ASC 310-30 pool. Troubled Debt Restructurings In certain situations, due to economic or legal reasons related to a borrower’s financial difficulties, the Company may grant a concession to the borrower for other than an insignificant period of time that it would not otherwise consider. At that time, except for ASC 310-30 loans, which are accounted for as pools, the related loan is classified as a troubled debt restructuring (“TDR”) and considered impaired. Modified ASC 310-30 loans accounted for in pools are not accounted for as TDRs, are not separated from the pools and are not classified as impaired loans. The concessions granted may include rate reductions, principal forgiveness, payment forbearance, extensions of maturity at rates of interest below those commensurate with the risk profile of the borrower, and other actions intended to minimize economic loss. A troubled debt restructured loan is generally placed on nonaccrual status at the time of the modification unless the borrower has no history of missed payments for six months prior to the restructuring. If the borrower performs pursuant to the modified loan terms for at least six months and the remaining loan balance is considered collectible, the loan is returned to accrual status. Impaired Loans An ASC 310-30 pool is considered to be impaired when it is probable that the Company will be unable to collect all the cash flows expected at acquisition, plus additional cash flows expected to be collected arising from changes in estimates after acquisition. All ASC 310-30 pools are evaluated individually for impairment based their expected total cash flows. The discount continues to be accreted on ASC 310-30 pools as long as there are expected future cash flows in excess of the current carrying amount of the pool. Non-ASC 310-30 and New loans are considered impaired when, based on current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due, according to the contractual terms of the loan agreements. All Non-ASC 310-30 and New loans of $250,000 or greater with an internal risk rating of substandard or below and on nonaccrual, as well as loans classified as TDRs are reviewed individually for impairment on a quarterly basis. Allowance for Loan Losses ("ALL") The Company’s ALL is established for both performing and nonperforming loans. The Company’s ALL is the amount considered adequate to absorb probable losses within the portfolio based on management’s evaluation of the size and current risk characteristics of the loan portfolio. Such evaluation considers numerous factors including, but not limited to, internal risk ratings, loss forecasts, collateral values, geographic location, borrower FICO scores, delinquency rates, nonperforming and restructured loans, origination channels, product mix, underwriting practices, industry conditions, economic trends and net charge-off trends. The ALL relates to New loans, estimated additional losses arising on Non-ASC 310-30 loans subsequent to the acquisitions and additional impairment recognized as a result of decreases in expected cash flows on ASC 310-30 pools due to further credit deterioration or other factors since the acquisitions. The ALL consists of both specific and general components. For ASC 310-30 pools, a specific valuation allowance is established when it is probable that the Company will be unable to collect all of the cash flows expected at acquisition, plus the additional cash flows expected to be collected arising from changes in estimates after acquisition. Expected cash flows are estimated on an individual loan basis and then aggregated at the ASC 310-30 pool level. The analysis of expected pool cash flows incorporates updated pool level expected prepayment rate, default rate, delinquency level and loss severity given default assumptions. These analyses incorporate information about loan performance, collateral values, the financial condition of the borrower, internal risk ratings, the Company’s own and industry historical delinquency and default severity data. The carrying value for ASC 310-30 pools is reduced by the amount of the calculated impairment, which is also the basis in which future accretion income is calculated. A charge-off is taken for an individual ASC 310-30 loan when it is deemed probable that the loan will be resolved for an amount less than its carrying value. The charge-off is taken to the specific allowance or mark as applicable. Alternatively, an improvement in the expected cash flows related to ASC 310-30 pools results in a reduction or recoupment of any previously established specific allowance with a corresponding credit to the provision for loan losses. Any recoupment recorded is limited to the amount of the remaining specific allowance for that pool, with any excess of expected cash flow resulting in a reclassification from non-accretable to accretable yield and an increase in the prospective yield of the pool. The New and Non-ASC 310-30 loan portfolios have limited delinquency and credit loss history and have not yet exhibited an observable loss trend. The credit quality of loans in these loan portfolios are impacted by delinquency status and debt service coverage generated by the borrowers’ businesses and fluctuations in the value of real estate collateral. Management considers delinquency status to be the most meaningful indicator of the credit quality of one-to-four single family residential, home equity loans and lines of credit and other consumer loans. Delinquency statistics are updated at least monthly. Internal risk ratings are considered the most meaningful indicator of credit quality for Non-ASC 310-30 and new commercial, construction, land and development, and commercial real estate loans. Internal risk ratings are a key factor in identifying loans that are individually evaluated for impairment and impact management’s estimates of loss factors used in determining the amount of the ALL. Internal risk ratings are updated on a continuous basis. Relationships with balances in excess of $250,000 are re-evaluated at least annually and more frequently if circumstances indicate that a change in risk rating may be warranted. New and Non-ASC 310-30 loans of $250,000 or greater with an internal risk rating of substandard or below and on nonaccrual, as well as loans classified as TDR are reviewed individually for impairment on a quarterly basis. The specific allowance established for these loans is based on a thorough analysis of the most probable source of repayment, including the present value of the loan’s expected future cash flows, the loan’s estimated market value or the estimated fair value of the underlying collateral less costs of disposition. General allowances are established for new and Non-ASC 310-30 loans that are not evaluated individually for impairment, which are evaluated by loan category based on common risk characteristics. In this process, general loan loss factors are established based on the following: industry historical losses segmented by portfolio and asset categories; trends in delinquencies and nonaccruals by loan portfolio segment and asset categories within those segments; portfolio segment and asset category production trends, including average risk ratings and loan-to value (“LTV”) ratios; current industry conditions, including real estate market trends; general economic conditions; credit concentrations by portfolio and asset categories; and portfolio quality, which encompasses an assessment of the quality and relevance of borrowers’ financial information and collateral valuations and average risk rating and migration trends within portfolios and asset categories. Other adjustments for qualitative factors may be made to the allowance after an assessment of internal and external influences on credit quality and loss severity that are not fully reflected in the historical loss or risk rating data. For these measurements, the Company uses assumptions and methodologies that are relevant to estimating the level of impairment and probable losses in the loan portfolio. To the extent that the data supporting such assumptions has limitations, management’s judgment and experience play a key role in recording the allowance estimates. Qualitative adjustments are considered for: portfolio credit quality trends, including levels of delinquency, charge-offs, nonaccrual, restructuring and other factors; policy and credit standards, including quality and experience of lending and credit management; and general economic factors, including national, regional and local conditions and trends. Additions to the ALL are made by provisions charged to earnings. The allowance is decreased by charge-offs of balances no longer deemed collectible. Charge-offs on new and Non-ASC 310-30 loans are recognized as follows: commercial loans are written-off when management determines them to be uncollectible; for unsecured consumer loans at 90 days past due; and for residential real estate loans and secured consumer loans when they become 120 to 180 days past due, depending on the collateral type. The Company reports recoveries on a cash basis at the time received. Recoveries on ASC 310-30 loans that were charged-off and Non-ASC 310-30 loans that were charged-off prior to the Acquisitions are recognized in earnings as income from resolution of acquired assets and do not affect the allowance for loan losses. All other recoveries are credited to the ALL. Loss Share Indemnification Asset and Clawback Liability On March 4, 2015, the Bank entered into an agreement with the FDIC to terminate all loss sharing agreements which were entered into in 2010 and 2011 in conjunction with the Bank’s acquisition of substantially all of the assets (“Covered Assets”) and assumption of substantially all of the liabilities of six failed banks in FDIC-assisted acquisitions. Under the early termination, all rights and obligations of the Bank and the FDIC under the loss share agreements, including the clawback provisions, have been eliminated. The amounts previously covered by the loss sharing agreements were the pre-acquisition book value of the underlying assets, the contractual balance of unfunded commitments that were acquired, and certain future net direct costs applicable to the Covered Assets. As required by the respective loss sharing agreements, the Company submitted a loss share certificate to the FDIC on a quarterly basis requesting reimbursement for losses on covered

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investment Securities	INVESTMENT SECURITIES The amortized cost, gross unrealized gains and losses and approximate fair values of securities available for sale are as follows: Amortized Cost Unrealized Fair Value December 31, 2017 Gains Losses (Dollars in thousands) Available for sale: U.S. Government agencies and sponsored enterprises obligations $ 43,471 $ 38 $ 671 $ 42,838 U.S. Government agencies and sponsored enterprises mortgage-backed securities 600,310 1,716 6,789 595,237 State and municipal obligations 26,766 125 719 26,172 Asset-backed securities 608,340 2,306 100 610,546 Corporate bonds and other debt securities 738,994 18,222 1,313 755,903 Preferred stock and other equity securities 88,520 2,279 692 90,107 Total available for sale $ 2,106,401 $ 24,686 $ 10,284 $ 2,120,803 Amortized Cost Unrealized Fair Value December 31, 2016 Gains Losses (Dollars in thousands) Available for sale: U.S. Government agencies and sponsored enterprises obligations $ 16,512 $ 76 $ 274 $ 16,314 U.S. Government agencies and sponsored enterprises mortgage-backed securities 566,377 1,760 9,691 558,446 State and municipal obligations 28,109 148 578 27,679 Asset-backed securities 574,521 3,852 550 577,823 Corporate bonds and other debt securities 560,191 4,490 5,387 559,294 Preferred stock and other equity securities 137,228 814 1,164 136,878 Total available for sale $ 1,882,938 $ 11,140 $ 17,644 $ 1,876,434 As part of the Company’s liquidity management strategy, the Company pledges loans and securities to secure borrowings from the FHLB and the FRB. The Company also pledges securities to collateralize repurchase agreements and interest rate swaps. Additionally, the Company has a Letter of Credit with the FHLB to collateralize public funds. The carrying value of all pledged securities totaled $834.9 million and $594.0 million at December 31, 2017 and 2016 , respectively. The amortized cost and estimated fair value of securities available for sale, by contractual maturity, are as follows: Amortized Cost Fair Value December 31, 2017 (Dollars in thousands) Available for sale: Due in one year or less $ 58,061 $ 58,605 Due after one year through five years 225,134 228,557 Due after five years through ten years 177,272 177,697 Due after ten years 305,293 317,216 U.S. Government agencies and sponsored enterprises obligations, mortgage-backed securities and tax-exempt mortgage securities, and asset-backed securities 1,252,121 1,248,621 Preferred stock and other equity securities 88,520 90,107 Total available for sale $ 2,106,401 $ 2,120,803 For purposes of the maturity table, U.S. Government agencies and sponsored enterprises obligations, agency mortgage-backed securities and asset-backed securities, the principal of which are repaid periodically, are presented as a single amount. The expected lives of these securities will differ from contractual maturities because borrowers may have the right to prepay the underlying loans with or without prepayment penalties. The following tables present the estimated fair values and gross unrealized losses on investment securities available for sale, aggregated by investment category and length of time individual securities have been in a continuous unrealized loss position as of the periods presented: Less than 12 Months 12 Months or More Total December 31, 2017 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss (Dollars in thousands) Available for sale: U.S. Government agencies and sponsored enterprises obligations $ 31,518 $ 268 $ 7,157 $ 403 $ 38,675 $ 671 U.S. Government agencies and sponsored enterprises mortgage-backed securities 207,735 1,836 175,810 4,953 383,545 6,789 State and municipal obligations 192 2 23,813 717 24,005 719 Asset-backed securities 36,542 100 — — 36,542 100 Corporate bonds and other debt securities 186,052 1,240 10,842 73 196,894 1,313 Preferred stock and other equity securities 6,041 26 20,337 666 26,378 692 Total available for sale $ 468,080 $ 3,472 $ 237,959 $ 6,812 $ 706,039 $ 10,284 Less than 12 Months 12 Months or More Total December 31, 2016 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss (Dollars in thousands) Available for sale: U.S. Government agencies and sponsored enterprises obligations $ 11,577 $ 274 $ — $ — $ 11,577 $ 274 U.S. Government agencies and sponsored enterprises mortgage-backed securities 372,145 9,261 11,781 430 383,926 9,691 State and municipal obligations 25,490 578 — — 25,490 578 Asset-backed securities 11,309 21 34,855 529 46,164 550 Corporate bonds and other debt securities 179,925 3,042 77,934 2,345 257,859 5,387 Preferred stock and other equity securities 49,996 1,144 5,123 20 55,119 1,164 Total available for sale $ 650,442 $ 14,320 $ 129,693 $ 3,324 $ 780,135 $ 17,644 At December 31, 2017 , the Company’s security portfolio consisted of 352 securities, of which 143 securities were in an unrealized loss position. A total of 85 were in an unrealized loss position for less than 12 months. The unrealized losses for these securities resulted primarily from changes in interest rates and spreads. The Company monitors its investment securities for OTTI. Impairment is evaluated on an individual security basis considering numerous factors, and their relative significance. The Company has evaluated the nature of unrealized losses in the investment securities portfolio to determine if OTTI exists. The unrealized losses relate to changes in market interest rates and market conditions that do not represent credit-related impairments. Furthermore, the Company does not intend to sell nor is it more likely than not that it will be required to sell these investments before the recovery of their amortized cost basis. Management has completed an assessment of each security in an unrealized loss position for credit impairment and has determined that no individual security was other-than-temporarily impaired at December 31, 2017 or 2016 . The following describes the basis under which the Company has evaluated OTTI: U.S. Government Agencies and Sponsored Enterprises Obligations and Agency Mortgage-Backed Securities (“MBS”): The unrealized losses associated with U.S. Government agencies and sponsored enterprises obligations and agency MBS are primarily driven by changes in interest rates. These securities have either an explicit or implicit U.S. government guarantee. Asset-Backed Securities and Corporate Bonds & Other Debt Securities: Securities were generally underwritten in accordance with the Company’s investment standards prior to the decision to purchase, without relying on a bond issuer’s guarantee in making the investment decision. These investments are investment grade and will continue to be monitored as part of the Company’s ongoing impairment analysis, but are expected to perform in accordance with their terms. Preferred Stock and Other Equity Securities: The unrealized losses associated with preferred stock and other equity securities in large U.S. financial institutions are primarily driven by changes in interest rates and spreads. These securities were generally underwritten in accordance with the Company’s investment standards prior to the decision to purchase. Gross realized gains and losses on the sale of securities available for sale are shown below. The cost of securities sold is based on the specific identification method. Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Gross realized gains $ 4,364 $ 3,645 $ 2,065 Gross realized losses (5,252 ) (2,066 ) (1,047 ) Net realized gains (losses) $ (888 ) $ 1,579 $ 1,018

Loans, Net

Loans, Net	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Loans, Net	LOANS, NET The Company’s loan portfolio consists of New and Acquired loans. The Company classifies originated loans and purchased loans not acquired through business combinations as New loans. The Company classifies loans acquired through business combinations as Acquired loans. All acquired loans not specifically excluded under ASC 310-30 are accounted for under ASC 310-30. The remaining portfolio of acquired loans excluded under ASC 310-30 are accounted for under ASC 310-20 and are classified as Non-ASC 310-30 loans. The following tables summarize the Company’s loans by portfolio and segment as of the periods presented, net of deferred fees, costs, premiums and discounts: December 31, 2017 ASC 310-30 Loans Non-ASC 310-30 Loans New Loans (1) Total (Dollars in thousands) Real estate loans: Commercial real estate $ 104,335 $ 37,736 $ 2,103,788 $ 2,245,859 Owner-occupied commercial real estate — 16,100 987,781 1,003,881 1-4 single family residential 27,513 57,695 2,185,362 2,270,570 Construction, land and development 13,167 5,889 684,462 703,518 Home equity loans and lines of credit — 34,589 59,636 94,225 Total real estate loans $ 145,015 $ 152,009 $ 6,021,029 $ 6,318,053 Other loans: Commercial and industrial $ 12,631 $ 5,062 $ 1,634,372 $ 1,652,065 Consumer 1,423 259 5,984 7,666 Total other loans 14,054 5,321 1,640,356 1,659,731 Total loans held in portfolio $ 159,069 $ 157,330 $ 7,661,385 $ 7,977,784 Allowance for loan losses (47,145 ) Loans held in portfolio, net $ 7,930,639 December 31, 2016 ASC 310-30 Loans Non-ASC 310-30 Loans New Loans (1) Total (Dollars in thousands) Real estate loans: Commercial real estate $ 130,628 $ 38,786 $ 1,438,427 $ 1,607,841 Owner-occupied commercial real estate — 18,477 769,814 788,291 1-4 single family residential 31,476 66,854 2,012,856 2,111,186 Construction, land and development 17,657 6,338 651,253 675,248 Home equity loans and lines of credit — 42,295 49,819 92,114 Total real estate loans $ 179,761 $ 172,750 $ 4,922,169 $ 5,274,680 Other loans: Commercial and industrial $ 15,147 $ 5,815 $ 1,332,869 $ 1,353,831 Consumer 1,681 334 4,368 6,383 Total other loans 16,828 6,149 1,337,237 1,360,214 Total loans held in portfolio $ 196,589 $ 178,899 $ 6,259,406 $ 6,634,894 Allowance for loan losses (37,897 ) Loans held in portfolio, net $ 6,596,997 (1) Balance includes $(6.6) million and $3.2 million of net deferred fees, costs, and premium and discount as of December 31, 2017 and 2016 , respectively. At December 31, 2017 and 2016 , the UPB of ASC 310-30 loans were $183.9 million and $231.5 million , respectively. At December 31, 2017 and 2016 , the Company had pledged loans as collateral for FHLB advances of $3.36 billion and $3.20 billion , respectively. The recorded investments of consumer mortgage loans secured by 1-4 family residential real estate properties for which formal foreclosure proceedings are in process as of December 31, 2017 totaled $3.2 million . The balance of real estate owned includes $1.2 million and $1.7 million of residential real estate properties as of December 31, 2017 and 2016 , respectively. The Company held $289.1 million and $433.0 million of syndicated national loans as of December 31, 2017 and 2016 , respectively. During the years ended December 31, 2017 , 2016 and 2015 the Company purchased approximately $22.9 million , $199.0 million and $379.3 million in primarily 1-4 single family residential loans from third parties. During the years ended December 31, 2017 , 2016 and 2015 , the Company sold approximately $383.6 million , $128.7 million and $91.8 million , respectively, in loans to third parties. The accretable discount on ASC 310-30 loans represents the amount by which the undiscounted expected cash flows on such loans exceed their carrying value. The change in expected cash flow for certain ASC 310-30 loan pools resulted in the reclassification of $(2.3) million , $(28.7) million and $43.0 million between non-accretable and accretable discount during the years ended December 31, 2017 , 2016 and 2015 , respectively. Changes in accretable discount for ASC 310-30 loans were as follows: Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Balance at January 1, $ 60,990 $ 144,152 $ 156,197 Accretion (17,523 ) (54,427 ) (55,019 ) Reclassifications from non-accretable difference (2,305 ) (28,735 ) 42,974 Balance at December 31, $ 41,162 $ 60,990 $ 144,152

Allowance for Loan Losses

Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Allowance for Loan Losses	ALLOWANCE FOR LOAN LOSSES The Company’s accounting method for loans and the corresponding ALL differs depending on whether the loans are New or Acquired. The Company assesses and monitors credit risk and portfolio performance using distinct methodologies for Acquired loans, both ASC 310-30 loans and Non-ASC 310-30 Loans, and New Loans. Within each of these portfolios, the Company further disaggregates the portfolios into the following segments: Commercial real estate, Owner-occupied commercial real estate, 1-4 single family residential, Construction, land and development, Home equity loans and lines of credit, Commercial and industrial and Consumer. The ALL reflects management’s estimate of probable credit losses inherent in each of the segments. During the third quarter of 2017, in response to Hurricane Irma, the Company recorded an unallocated provision expense of $1.5 million to reflect management's estimate of probable credit losses inherent in the loan portfolio related specifically to the storm. Changes in the ALL by loan portfolio and segment for the years ended December 31, 2017 , 2016 , and 2015 are as follows: Commercial Real Estate Owner- Occupied Commercial Real Estate 1- 4 Single Family Residential Construction, Land and Development Home Equity Loans and Lines of Credit Commercial and Industrial Consumer Total (Dollars in thousands) Balance at January 1, 2017 $ 10,123 $ 2,597 $ 7,379 $ 4,677 $ 648 $ 12,245 $ 228 $ 37,897 Provision (credit) for ASC 310-30 loans (839 ) — 31 (51 ) — (192 ) (99 ) (1,150 ) Provision (credit) for non-ASC 310-30 loans (8 ) (6 ) (146 ) (11 ) (37 ) (64 ) (29 ) (301 ) Provision (credit) for New loans 4,723 774 720 (227 ) 73 3,260 43 9,366 Provision (credit) for Unallocated — — — — — — — 1,500 Total provision 3,876 768 605 (289 ) 36 3,004 (85 ) 9,415 Charge-offs for ASC 310-30 loans (9 ) — (35 ) (43 ) — (29 ) — (116 ) Charge-offs for non-ASC 310-30 loans (30 ) — (69 ) — (7 ) (3 ) — (109 ) Charge-offs for New loans (131 ) — — — (3 ) (150 ) — (284 ) Total charge-offs (170 ) — (104 ) (43 ) (10 ) (182 ) — (509 ) Recoveries for ASC 310-30 loans 41 — — — — 70 100 211 Recoveries for non-ASC 310-30 loans — — 98 — — 4 29 131 Recoveries for New loans — — — — — — — — Total recoveries 41 — 98 — — 74 129 342 Ending ALL balance ASC 310-30 loans 1,448 — 25 145 — 126 145 1,889 Non-ASC 310-30 loans 338 55 184 36 199 313 6 1,131 New loans 12,084 3,310 7,769 4,164 475 14,702 121 42,625 Unallocated — — — — — — — 1,500 Balance at December 31, 2017 $ 13,870 $ 3,365 $ 7,978 $ 4,345 $ 674 $ 15,141 $ 272 $ 47,145 Commercial Real Estate Owner- Occupied Commercial Real Estate 1- 4 Single Family Residential Construction, Land and Development Home Equity Loans and Lines of Credit Commercial and Industrial Consumer Total (Dollars in thousands) Balance at January 1, 2016 $ 8,450 $ 2,243 $ 6,425 $ 3,404 $ 483 $ 7,665 $ 456 $ 29,126 Provision (credit) for ASC 310-30 loans (124 ) — 3 (128 ) — (108 ) (156 ) (513 ) Provision (credit) for non-ASC 310-30 loans (1,512 ) (401 ) (31 ) 11 (21 ) 316 8 (1,630 ) Provision (credit) for New loans 2,024 756 982 1,351 213 4,440 32 9,798 Total provision 388 355 954 1,234 192 4,648 (116 ) 7,655 Charge-offs for ASC 310-30 loans (429 ) — (31 ) (33 ) — (79 ) (106 ) (678 ) Charge-offs for non-ASC 310-30 loans — (1 ) — — (35 ) — (6 ) (42 ) Charge-offs for New loans — — — — — — — — Total charge-offs (429 ) (1 ) (31 ) (33 ) (35 ) (79 ) (112 ) (720 ) Recoveries for ASC 310-30 loans 910 — 31 72 — 11 — 1,024 Recoveries for non-ASC 310-30 loans 804 — — — 8 — — 812 Recoveries for New loans — — — — — — — — Total recoveries 1,714 — 31 72 8 11 — 1,836 Ending ALL balance ASC 310-30 loans 2,255 — 29 239 — 277 144 2,944 Non-ASC 310-30 loans 376 61 301 47 243 376 6 1,410 New loans 7,492 2,536 7,049 4,391 405 11,592 78 33,543 Balance at December 31, 2016 $ 10,123 $ 2,597 $ 7,379 $ 4,677 $ 648 $ 12,245 $ 228 $ 37,897 Commercial Real Estate Owner- Occupied Commercial Real Estate 1- 4 Single Family Residential Construction, Land and Development Home Equity Loans and Lines of Credit Commercial and Industrial Consumer Total (Dollars in thousands) Balance at January 1, 2015 $ 8,206 $ 1,020 $ 4,740 $ 2,456 $ 355 $ 5,745 $ 358 $ 22,880 Provision (credit) for ASC 310-30 loans (1,487 ) — (37 ) (681 ) — (39 ) 175 (2,069 ) Provision (credit) for non-ASC 310-30 loans 589 405 46 (39 ) 138 11 6 1,156 Provision (credit) for New loans 1,012 818 2,066 1,317 122 2,417 (16 ) 7,736 Total provision 114 1,223 2,075 597 260 2,389 165 6,823 Charge-offs for ASC 310-30 loans (270 ) — (436 ) (56 ) — (643 ) (60 ) (1,465 ) Charge-offs for non-ASC 310-30 loans — — (128 ) — (132 ) — (8 ) (268 ) Charge-offs for New loans — — — — — (15 ) — (15 ) Total charge-offs (270 ) — (564 ) (56 ) (132 ) (658 ) (68 ) (1,748 ) Recoveries for ASC 310-30 loans 400 — 174 407 — 177 1 1,159 Recoveries for non-ASC 310-30 loans — — — — — — — — Recoveries for New loans — — — — — 12 — 12 Total recoveries 400 — 174 407 — 189 1 1,171 Ending ALL balance ASC 310-30 loans 1,898 — 26 328 — 453 406 3,111 Non-ASC 310-30 loans 1,084 463 332 36 291 60 4 2,270 New loans 5,468 1,780 6,067 3,040 192 7,152 46 23,745 Balance at December 31, 2015 $ 8,450 $ 2,243 $ 6,425 $ 3,404 $ 483 $ 7,665 $ 456 $ 29,126 Credit Quality Indicators In evaluating credit risk, the Company looks at multiple factors; however, management considers delinquency status to be the most meaningful indicator of the credit quality of 1-4 single family residential, home equity loans and lines of credit and consumer loans. Delinquency statistics are updated at least monthly. Internal risk ratings are considered the most meaningful indicator of credit quality for Non-ASC 310-30 and New commercial, construction, land and development and commercial real estate loans. Internal risk ratings are updated on a continuous basis. The following tables present an aging analysis of the recorded investment for delinquent loans by portfolio and segment (excluding loans accounted for under ASC 310-30): Accruing December 31, 2017 30 to 59 Days Past Due 60 to 89 Days Past Due 90 Days or More Past Due Non- Accrual Total (Dollars in thousands) New loans: Real estate loans: Commercial real estate $ 324 $ — $ — $ — $ 324 Owner-occupied commercial real estate 843 150 — — 993 1-4 single family residential 1,179 1,310 — 3,167 5,656 Construction, land and development — — — — — Home equity loans and lines of credit — — — 126 126 Total real estate loans $ 2,346 $ 1,460 $ — $ 3,293 $ 7,099 Other loans: Commercial and industrial $ 4,980 $ 2,167 $ — $ — $ 7,147 Consumer — — — — — Total other loans 4,980 2,167 — — 7,147 Total New loans $ 7,326 $ 3,627 $ — $ 3,293 $ 14,246 Acquired loans: Real estate loans: Commercial real estate $ 360 $ — $ — $ 3,893 $ 4,253 Owner-occupied commercial real estate 290 — — 494 784 1-4 single family residential 892 44 — 1,331 2,267 Construction, land and development — — — — — Home equity loans and lines of credit 1,128 — — 1,720 2,848 Total real estate loans $ 2,670 $ 44 $ — $ 7,438 $ 10,152 Other loans: Commercial and industrial $ 101 $ — $ — $ 394 $ 495 Consumer — — — — — Total other loans 101 — — 394 495 Total acquired loans $ 2,771 $ 44 $ — $ 7,832 $ 10,647 Accruing December 31, 2016 30 to 59 Days Past Due 60 to 89 Days Past Due 90 Days or More Past Due Non- Accrual Total (Dollars in thousands) New loans: Real estate loans: Commercial real estate $ — $ — $ — $ 581 $ 581 Owner-occupied commercial real estate — — — — — 1-4 single family residential 1,593 — — 1,821 3,414 Construction, land and development 449 — — — 449 Home equity loans and lines of credit 255 — — 243 498 Total real estate loans $ 2,297 $ — $ — $ 2,645 $ 4,942 Other loans: Commercial and industrial $ — $ — $ — $ — $ — Consumer — — — — — Total other loans — — — — — Total New loans $ 2,297 $ — $ — $ 2,645 $ 4,942 Acquired Loans: Real estate loans: Commercial real estate $ — $ — $ — $ 4,720 $ 4,720 Owner-occupied commercial real estate 93 — — 2,502 2,595 1-4 single family residential 207 — — 2,728 2,935 Construction, land and development — — — — — Home equity loans and lines of credit 520 42 — 2,557 3,119 Total real estate loans $ 820 $ 42 $ — $ 12,507 $ 13,369 Other loans: Commercial and industrial $ — $ 128 $ — $ 325 $ 453 Consumer — — — — — Total other loans — 128 — 325 453 Total acquired loans $ 820 $ 170 $ — $ 12,832 $ 13,822 Loans exhibiting potential credit weaknesses that deserve management's close attention and that, if left uncorrected, may result in deterioration of the repayment capacity of the borrower, are categorized as special mention. Loans with well-defined credit weaknesses including payment defaults, declining collateral values, frequent overdrafts, operating losses, increasing balance sheet leverage, inadequate cash flow, project cost overruns, unreasonable construction delays, past due real estate taxes or exhausted interest reserves, are assigned an internal risk rating of substandard. A loan with a weakness so severe that collection in full is highly questionable or improbable will be assigned an internal risk rating of doubtful. The following tables summarize the Company’s commercial Non-ASC 310-30 and New loans by key indicators of credit quality. Loans accounted for under ASC 310-30 are excluded from the following analysis because their related allowance is determined by loan pool performance: December 31, 2017 Pass Special Mention Substandard Doubtful (Dollars in thousands) New loans: Commercial real estate $ 2,095,560 $ 6,066 $ 2,162 $ — Owner-occupied commercial real estate 987,781 — — — Construction, land and development 684,462 — — — Commercial and industrial 1,617,462 16,910 — — Total New loans $ 5,385,265 $ 22,976 $ 2,162 $ — Acquired loans: Commercial real estate $ 33,496 $ — $ 4,240 $ — Owner-occupied commercial real estate 15,607 — 493 — Construction, land and development 5,889 — — — Commercial and industrial 4,324 — 738 — Total acquired loans $ 59,316 $ — $ 5,471 $ — December 31, 2016 Pass Special Substandard Doubtful (Dollars in thousands) New loans: Commercial real estate $ 1,435,633 $ — $ 2,794 $ — Owner-occupied commercial real estate 769,640 174 — — Construction, land and development 651,253 — — — Commercial and industrial 1,332,869 — — — Total New loans $ 4,189,395 $ 174 $ 2,794 $ — Acquired loans: Commercial real estate $ 33,705 $ — $ 5,081 $ — Owner-occupied commercial real estate 18,388 — 89 — Construction, land and development 6,338 — — — Commercial and industrial 5,134 — 681 — Total acquired loans $ 63,565 $ — $ 5,851 $ — Internal risk ratings are a key factor in identifying loans to be individually evaluated for impairment and impact management’s estimates of loss factors used in determining the amount of the ALL. The following tables show the Company’s investment in loans disaggregated based on the method of evaluating impairment: Loans - Recorded Investment Allowance for Credit Loss December 31, 2017 Individually Evaluated for Impairment Collectively Evaluated for Impairment ASC 310- 30 Loans Individually Evaluated for Impairment Collectively Evaluated for Impairment ASC 310- 30 Loans (Dollars in thousands) New loans: Real estate loans: Commercial real estate $ — $ 2,103,788 $ — $ — $ 12,084 $ — Owner-occupied commercial real estate — 987,781 — — 3,310 — 1-4 single family residential 1,096 2,184,266 — — 7,769 — Construction, land and development — 684,462 — — 4,164 — Home equity loans and lines of credit 130 59,506 — 66 409 — Total real estate loans $ 1,226 $ 6,019,803 $ — $ 66 $ 27,736 $ — Other loans Commercial and industrial $ — $ 1,634,372 $ — $ — $ 14,702 $ — Consumer — 5,984 — — 121 — Total other loans $ — $ 1,640,356 $ — $ — $ 14,823 $ — Acquired loans: Real estate loans: Commercial real estate $ 3,893 $ 33,843 $ 104,335 $ 129 $ 209 $ 1,448 Owner-occupied commercial real estate — 16,100 — — 55 — 1-4 single family residential 267 57,428 27,513 — 184 25 Construction, land and development — 5,889 13,167 — 36 145 Home equity loans and lines of credit 495 34,094 — — 199 — Total real estate loans $ 4,655 $ 147,354 $ 145,015 $ 129 $ 683 $ 1,618 Other loans Commercial and industrial 272 4,790 12,631 272 41 126 Consumer — 259 1,423 — 6 145 Total other loans $ 272 $ 5,049 $ 14,054 $ 272 $ 47 $ 271 Total Loans: Unallocated $ — $ 7,977,784 $ — $ — $ 1,500 $ — Loans - Recorded Investment Allowance for Credit Loss December 31, 2016 Individually Evaluated for Impairment Collectively Evaluated for Impairment ASC 310- 30 Loans Individually Evaluated for Impairment Collectively Evaluated for Impairment ASC 310- 30 Loans (Dollars in thousands) New loans: Real estate loans: Commercial real estate $ 581 $ 1,437,846 $ — $ 221 $ 7,271 $ — Owner-occupied commercial real estate — 769,814 — — 2,536 — 1-4 single family residential 524 2,012,332 — — 7,049 — Construction, land and development — 651,253 — — 4,391 — Home equity loans and lines of credit 66 49,753 — 66 339 — Total real estate loans $ 1,171 $ 4,920,998 $ — $ 287 $ 21,586 $ — Other loans Commercial and industrial — 1,332,869 — — 11,592 — Consumer — 4,368 — — 78 — Total other loans $ — $ 1,337,237 $ — $ — $ 11,670 $ — Acquired Loans: Real estate loans: Commercial real estate $ 4,720 $ 34,066 $ 130,628 $ 175 $ 201 $ 2,255 Owner-occupied commercial real estate — 18,477 — — 61 — 1-4 single family residential 1,612 65,242 31,476 88 213 29 Construction, land and development — 6,338 17,657 — 47 239 Home equity loans and lines of credit 1,050 41,245 — — 243 — Total real estate loans $ 7,382 $ 165,368 $ 179,761 $ 263 $ 765 $ 2,523 Other loans Commercial and industrial 325 5,490 15,147 325 51 277 Consumer — 334 1,681 — 6 144 Total other loans $ 325 $ 5,824 $ 16,828 $ 325 $ 57 $ 421 The following tables set forth certain information regarding the Company’s impaired loans (excluding loans accounted for under ASC 310-30) that were evaluated for specific reserves: Impaired Loans - With Allowance Impaired Loans - With no Allowance December 31, 2017 Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance (Dollars in thousands) New loans: Real estate loans: Commercial real estate $ — $ — $ — $ — $ — Owner-occupied commercial real estate — — — — — 1-4 single family residential — — — 1,096 1,096 Construction, land and development — — — — — Home equity loans and lines of credit 66 66 66 63 63 Total real estate loans $ 66 $ 66 $ 66 $ 1,159 $ 1,159 Other loans Commercial and industrial — — — — — Consumer — — — — — Total other loans $ — $ — $ — $ — $ — Acquired loans: Real estate loans: Commercial real estate $ 336 $ 347 $ 129 $ 3,557 $ 4,991 Owner-occupied commercial real estate — — — — — 1-4 single family residential — — — 267 267 Construction, land and development — — — — — Home equity loans and lines of credit — — — 495 495 Total real estate loans $ 336 $ 347 $ 129 $ 4,319 $ 5,753 Other loans Commercial and industrial 272 272 272 — — Consumer — — — — — Total other loans $ 272 $ 272 $ 272 $ — $ — Impaired Loans - With Allowance Impaired Loans - With no Allowance December 31, 2016 Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance (Dollars in thousands) New loans: Real estate loans: Commercial real estate $ 581 $ 581 $ 221 $ — $ — Owner-occupied commercial real estate — — — — — 1-4 single family residential — — — 524 524 Construction, land and development — — — — — Home equity loans and lines of credit 66 66 66 — — Total real estate loans $ 647 $ 647 $ 287 $ 524 $ 524 Other loans Commercial and industrial — — — — — Consumer — — — — — Total other loans $ — $ — $ — $ — $ — Acquired loans: Real estate loans: Commercial real estate $ 630 $ 650 $ 175 $ 4,090 $ 5,397 Owner-occupied commercial real estate — — — — — 1-4 single family residential 565 512 88 1,047 1,047 Construction, land and development — — — — — Home equity loans and lines of credit — — — 1,050 1,415 Total real estate loans $ 1,195 $ 1,162 $ 263 $ 6,187 $ 7,859 Other loans Commercial and industrial 325 325 325 — — Consumer — — — — — Total other loans $ 325 $ 325 $ 325 $ — $ — The following table presents the average recorded investment and interest income recognized during the period subsequent to impairment on loans individually evaluated for impairment: Years Ended December 31, 2017 2016 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized (Dollars in thousands) Impaired loans with no related allowance: Real estate loans: Commercial real estate $ 3,653 $ — $ 4,245 $ — Owner-occupied commercial real estate — — — — 1-4 single family residential 1,363 — 816 — Construction, land and development — — — — Home equity loans and lines of credit 670 — 1,272 — Total real estate loans $ 5,686 $ — $ 6,333 $ — Other loans: Commercial and industrial — — — — Consumer — — — — Total other loans $ — $ — $ — $ — Impaired loans with an allowance: Real estate loans: Commercial real estate $ 480 $ — $ 959 $ — Owner-occupied commercial real estate — — — — 1-4 single family residential — — 424 — Construction, land and development — — — — Home equity loans and lines of credit 66 — 44 — Total real estate loans $ 546 $ — $ 1,427 $ — Other loans: Commercial and industrial 317 — 170 — Consumer — — — — Total other loans $ 317 $ — $ 170 $ —

Covered Assets and Loss Sharing

Covered Assets and Loss Sharing Agreements	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Covered Assets and Loss Sharing Agreements	COVERED ASSETS AND LOSS SHARING AGREEMENTS On March 4, 2015, the Bank entered into an agreement with the FDIC to terminate all loss sharing agreements which were entered into in 2010 and 2011 in conjunction with the Bank’s acquisition of substantially all of the assets and assumption of substantially all of the liabilities of six failed banks in FDIC-assisted acquisitions. Under the early termination agreements, all rights and obligations of the Bank and the FDIC under the loss share agreements, including the clawback provisions, have been eliminated. The Bank paid the FDIC $14.8 million as consideration for the early termination to settle its obligation under the FDIC Clawback Liability. The early termination was recorded in the Bank’s financial statements by removing the FDIC Indemnification Asset receivable, the FDIC Clawback liability and recording a one-time, pre-tax loss on termination of $65.5 million . Changes in the loss share indemnification asset for the periods presented were as follows: Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Balance at beginning of period $ — $ — $ 63,168 Termination of FDIC loss sharing agreements — — (63,168 ) Balance at end of period $ — $ — $ — The following table summarizes the changes in the clawback liability for the periods presented: Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Balance at beginning of period $ — $ — $ 13,846 Termination of FDIC loss sharing agreements — — (13,846 ) Balance at end of period $ — $ — $ —

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Premises and Equipment	NOTE 6. PREMISES AND EQUIPMENT The major components of premises and equipment are as follows: December 31, 2017 2016 (Dollars in thousands) Land $ 7,624 $ 7,624 Building and improvements 24,653 24,653 Furniture, fixtures and equipment 14,956 13,197 Leasehold improvements 5,164 4,454 Construction in Process 663 525 Software 3,354 3,021 Total 56,414 53,474 Less: Accumulated depreciation (20,270 ) (16,822 ) Total premises and equipment, net $ 36,144 $ 36,652 Total depreciation expense for the years ended December 31, 2017 , 2016 and 2015 totaled $3.6 million , $3.6 million and $3.8 million , respectively. Operating Leases The Company has entered into various operating leases for premises and equipment used in its operation. Total rental expense for the years ended December 31, 2017 , 2016 and 2015 totaled $7.6 million , $7.6 million , and $7.5 million , respectively. As of December 31, 2017 , future minimum lease payments under non-cancellable operating leases were as follows (in thousands): Years Ended December 31, 2018 2019 2020 2021 2022 Thereafter Total Future minimum lease payments $ 5,205 $ 4,707 $ 4,438 $ 3,145 $ 2,398 $ 12,431 $ 32,324

Goodwill and Intangibles

Goodwill and Intangibles	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangibles	GOODWILL AND INTANGIBLES Goodwill and other intangible assets are summarized as follows: December 31, 2017 2016 (Dollars in thousands) Goodwill $ 81,204 $ 81,204 Core deposit intangible 14,370 14,370 Less: Accumulated amortization (10,702 ) (9,679 ) Net core deposit intangible $ 3,668 $ 4,691 Amortization expense for core deposit intangibles for the years ended December 31, 2017 , 2016 , and 2015 totaled $1.0 million , $1.2 million and $1.6 million , respectively. The estimated amount of amortization expense for core deposit intangible assets to be recognized over the next five fiscal years is as follows: 2018 2019 2020 2021 2022 (Dollars in thousands) Core deposit intangible $ 1,023 $ 1,023 $ 510 $ 360 $ 360

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	DERIVATIVES No derivative positions held by the Company as of December 31, 2017 were designated as hedging instruments under ASC Topic 815-10. The Company is a party to interest rate derivatives that are not designated as hedging instruments. The Company uses interest rate derivative contracts, such as swaps and caps, in the normal course of business to meet the financial needs of customers. The interest rate swaps that the Company enters into with customers allow the customers to convert variable rate loans to fixed rates. At the same time the interest rate swap is entered into with the customer, an offsetting interest rate swap is entered into with another financial institution. The changes in the fair value of the swaps offset each other, except for any differences in the credit risk of the counterparties, which is determined by considering the risk rating, probability of default and loss given default of each counterparty. The Company recorded $6.8 million , $4.4 million and $5.2 million of derivative contract fees in noninterest income in the accompanying consolidated statements of income for the years ended December 31, 2017 , 2016 , and 2015 , respectively. In addition, the Company has entered into two risk participation agreements. The notional amount of the risk participation agreements sold was $32.5 million as of December 31, 2017. Assuming all underlying third party customers referenced in the swap agreements defaulted at December 31, 2017, there would be an immaterial amount of exposure to the Company. These risk participation agreements mature in 2021. No credit changes in counterparty credit were identified. There was no change in the fair value of derivative assets and derivative liabilities attributable to credit risk included in noninterest expense in the consolidated statements of income for the years ended December 31, 2017 , 2016 , and 2015 . The following tables summarize the Company’s derivatives outstanding included in other assets and other liabilities in the accompanying consolidated balance sheets: Derivative Assets Derivative Liabilities December 31, 2017 Notional Fair Value Notional Fair Value (Dollars in thousands) Derivatives not designated as hedging instruments under ASC Topic 815-10 Interest rate swaps—pay floating, receive fixed $ 757,887 $ 11,678 $ 380,233 $ 4,180 Interest rate swaps—pay fixed, receive floating 380,233 — 757,887 7,498 Interest rate caps—purchased 94,884 155 — — Interest rate caps—sold — — 94,884 155 Total derivatives $ 1,233,004 $ 11,833 $ 1,233,004 $ 11,833 Derivative Assets Derivative Liabilities December 31, 2016 Notional Fair Value Notional Fair Value (Dollars in thousands) Derivatives not designated as hedging instruments under ASC Topic 815-10 Interest rate swaps—pay floating, receive fixed $ 708,426 $ 15,268 $ 182,848 $ 2,908 Interest rate swaps—pay fixed, receive floating 182,848 — 708,426 12,360 Total derivatives $ 891,274 $ 15,268 $ 891,274 $ 15,268 The derivative transactions entered into with a financial institution are subject to an enforceable master netting arrangement. The following table summarizes the gross and net fair values of the Company’s derivatives outstanding with this counterparty included in other liabilities in the accompanying consolidated balance sheets: December 31, 2017 Gross amounts of recognized liabilities Gross amounts offset in the consolidated balance sheets Net amounts in the consolidated balance sheets (Dollars in thousands) Offsetting derivative liabilities Counterparty A—Interest rate contracts $ 11,833 $ (4,491 ) $ 7,342 Total $ 11,833 $ (4,491 ) $ 7,342 December 31, 2016 Gross amounts of recognized liabilities Gross amounts offset in the consolidated balance sheets Net amounts in the consolidated balance sheets (Dollars in thousands) Offsetting derivative liabilities Counterparty A—Interest rate contracts $ 15,268 $ (2,908 ) $ 12,360 Total $ 15,268 $ (2,908 ) $ 12,360 At December 31, 2017 , the Company has pledged investment securities available for sale with a carrying amount of $25.7 million as collateral for the interest rate swaps in a liability position. The amount of collateral required to be posted by the Company varies based on the settlement value of outstanding swaps. As of December 31, 2017 and 2016 , substantially all of the floating rate terms within the interest rate contracts held by the Company were indexed to 1-month LIBOR . The fair value of the derivative assets and liabilities are included in a table in Note 19 “Fair Value Measurements,” in the line items “Derivative assets” and “Derivative liabilities.”

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Deposits	DEPOSITS The following table sets forth the Company’s deposits by category: December 31, 2017 2016 (Dollars in thousands) Noninterest-bearing demand deposits $ 1,236,685 $ 905,905 Interest-bearing demand deposits 1,454,097 1,004,452 Interest-bearing NOW accounts 363,191 398,823 Savings and money market accounts 3,013,237 2,780,697 Time deposits 2,606,717 2,215,794 Total deposits $ 8,673,927 $ 7,305,671 Time deposits $100,000 and greater $ 1,983,445 $ 1,675,162 Time deposits greater than $250,000 1,078,702 843,683 The aggregate amount of overdraft demand deposits reclassified to loans was $1.1 million at December 31, 2017 . The aggregate amount of maturities for time deposits for each of the five years following the latest balance sheet date totaled $1.59 billion , $983.0 million , $21.7 million , $7.3 million and $6.6 million , respectively. The Company holds brokered deposits through an insured deposit sweep program of $656.4 million and $693.9 million at December 31, 2017 and 2016 , respectively. The Company holds brokered certificates of deposit of $85.2 million and $1.2 million at December 31, 2017 and 2016 , respectively.

FHLB and Other Borrowings

FHLB and Other Borrowings	12 Months Ended
	Dec. 31, 2017
Federal Home Loan Banks [Abstract]
FHLB and Other Borrowings	FHLB AND OTHER BORROWINGS Advances from the FHLB and other borrowings outstanding for the periods presented are as follows: December 31, 2017 Range of Contractual Interest Rates (Dollars in thousands) Repayable during the years ending December 31, 2018 $ 270,000 1.41% - 1.59% 2019 — — % 2020 and beyond 400,000 1.34% - 2.28% Total FHLB advances 670,000 Securities sold under repurchase agreements 50,336 1.87% - 2.41% Retail repurchase agreements 28,777 0.25 % Total contractual outstanding 749,113 Fair value adjustment — Total Borrowings $ 749,113 December 31, 2016 Range of Contractual Interest Rates Repayable during the years ending December 31, 2017 $ 342,250 0.62% - 0.80% 2018 50,000 1.53 % 2019 and beyond 200,000 1.34% - 1.61% Total FHLB advances 592,250 Securities sold under repurchase agreements 131,621 1.40% - 4.35% Retail repurchase agreements 26,386 0.25 % Total contractual outstanding 750,257 Fair value adjustment 846 Total Borrowings $ 751,103 For the years ended December 31, 2017 and 2016 , the Company maintained advances with the FHLB averaging $798.4 million and $612.1 million , respectively, with an average cost of approximately 1.45% and 0.94% , respectively. Substantially all FHLB advances outstanding at December 31, 2017 and 2016 had fixed interest rates. Interest expense on FHLB advances was $11.6 million , $5.8 million and $4.0 million for the years ended December 31, 2017 , 2016 and 2015 . The fair value adjustment on repurchase agreements was amortized as a reduction to interest expense over the remaining term of the advances using the effective yield method. The Company pledges loans and securities as collateral for FHLB advances and FRB Discount Window borrowings. See Notes 2 and 3 to these consolidated financial statements for further information. At December 31, 2017 , the Company had additional capacity to borrow from the FHLB of $1.40 billion . Also, at December 31, 2017 , the Company has unused credit lines with financial institutions of $540.0 million .

Regulatory Capital

Regulatory Capital	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Regulatory Capital	REGULATORY CAPITAL The Company and the Bank are subject to regulatory capital adequacy requirements promulgated by federal regulatory agencies. The Board of Governors of the Federal Reserve System establishes capital requirements, including well capitalized standards, for the Company, and the OCC has similar requirements for the Bank. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company’s financial statements. The capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors. Banking regulations identify five capital categories for insured depository institutions: well capitalized, adequately capitalized, undercapitalized, significantly undercapitalized and critically undercapitalized. As of December 31, 2017 and 2016 , all capital ratios of the Company and the Bank exceeded the well capitalized levels under the applicable regulatory capital adequacy guidelines. The ability of the Company and the Bank to pay dividends is subject to statutory and regulatory restrictions on the payment of cash dividends. Quantitative measures established by regulation to ensure capital adequacy require the Company and Bank to maintain minimum amounts and ratios (set forth in the following table) of total and Tier I capital (as defined) to average assets (as defined). Management believes, at December 31, 2017 and 2016 , that the Company and Bank met all capital adequacy requirements to which they are subject. The Bank’s and Company’s regulatory capital levels are as follows: Actual Minimum Capital Requirement Minimum To Be Well Capitalized Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) December 31, 2017 Tier 1 leverage ratio Company $ 1,079,851 10.5 % $ 411,177 4.0 % $ 513,972 5.0 % Bank 927,426 9.2 % 403,527 4.0 % 504,409 5.0 % Common equity tier 1 capital ratio Company 1,079,851 11.9 % 409,482 4.5 % 591,475 6.5 % Bank 927,426 10.4 % 400,187 4.5 % 578,047 6.5 % Tier 1 risk-based capital ratio Company 1,079,851 11.9 % 545,977 6.0 % 727,969 8.0 % Bank 927,426 10.4 % 533,582 6.0 % 711,443 8.0 % Total risk-based capital ratio Company 1,128,889 12.4 % 727,969 8.0 % 909,961 10.0 % Bank 975,663 11.0 % 711,443 8.0 % 889,304 10.0 % Actual Minimum Capital Requirement Minimum To Be Well Capitalized Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) December 31, 2016 Tier 1 leverage ratio Company $ 891,584 10.3 % $ 346,518 4.0 % $ 433,148 5.0 % Bank 795,207 9.3 % 340,856 4.0 % 426,070 5.0 % Common equity tier 1 capital ratio Company 891,584 11.9 % 336,328 4.5 % 485,807 6.5 % Bank 795,207 10.9 % 329,194 4.5 % 475,503 6.5 % Tier 1 risk-based capital ratio Company 891,584 11.9 % 448,437 6.0 % 597,916 8.0 % Bank 795,207 10.9 % 438,926 6.0 % 585,234 8.0 % Total risk-based capital ratio Company 930,821 12.5 % 597,916 8.0 % 747,395 10.0 % Bank 834,679 11.4 % 585,234 8.0 % 731,543 10.0 % The FDIC Order that the Bank entered into upon the acquisition of Premier American Bank requires the institution to maintain a ratio of Tier 1 common equity to total assets of at least 10% for a period of three years following its first FDIC-assisted transaction, and thereafter maintain a capital level sufficient to be well capitalized under regulatory standards during the remaining period of ownership of the investors subject to the FDIC Order. The Bank is currently subject to the well capitalized requirement but is no longer subject to the 10% Tier 1 common equity ratio requirement. The Bank is subject to regulations of certain federal and state agencies and can be periodically examined by those authorities. As a consequence, the Bank’s business is susceptible to the impacts of federal legislation and regulations issued by, but not limited to, the Board of Governors of the Federal Reserve System, OCC and FDIC.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Accumulated Other Comprehensive Income	ACCUMULATED OTHER COMPREHENSIVE INCOME Changes in AOCI for the periods indicated are summarized as follows: Year Ended December 31, 2017 Before Tax Tax Effect Net of Tax (Dollars in thousands) Balance at beginning of period $ (6,504 ) $ 2,509 $ (3,995 ) Unrealized gain (loss) on investment securities available for sale: Net unrealized holdings gain (loss) arising during the period 24,112 (9,244 ) 14,868 Amounts reclassified to (gain) loss on investment securities (3,206 ) 1,226 (1,980 ) Balance at end of period $ 14,402 $ (5,509 ) $ 8,893 Year Ended December 31, 2016 Before Tax Tax Effect Net of Tax (Dollars in thousands) Balance at beginning of period $ (15,371 ) $ 5,928 $ (9,443 ) Unrealized gain (loss) on investment securities available for sale: Net unrealized holdings gain (loss) arising during the period 11,582 (4,467 ) 7,115 Amounts reclassified to (gain) loss on investment securities (2,715 ) 1,048 (1,667 ) Balance at end of period $ (6,504 ) $ 2,509 $ (3,995 ) Year Ended December 31, 2015 Before Tax Tax Effect Net of Tax (Dollars in thousands) Balance at beginning of period $ 1,106 $ (427 ) $ 679 Unrealized gain (loss) on investment securities available for sale: Net unrealized holdings gain (loss) arising during the period (13,997 ) 5,399 (8,598 ) Amounts reclassified to (gain) loss on investment securities (2,480 ) 956 (1,524 ) Balance at end of period $ (15,371 ) $ 5,928 $ (9,443 )

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholders' Equity	STOCKHOLDERS’ EQUITY Class A and Class B Common Stock The shares of common stock of the Company are divided into two classes: Class A common stock and Class B common stock. The Class A common stock possesses all of the voting power for all matters requiring action by holders of the Company’s common stock, with certain limited exceptions. Each share of Class B common stock is convertible into one share of Class A common stock, subject to certain restrictions. The Class A common stock is not convertible. Other than with respect to voting rights and the restrictions on transfer and conversion relating to the Class B common stock, the Class A common stock and the Class B common stock are treated equally and identically, including with respect to distributions. In 2017 and 2016 , the Company converted 188,474 and 3,545,408 , respectively, Class B common shares to Class A common shares in a voluntary exchange with certain shareholders. This exchange was made on 1 :1 ratio and no consideration was paid or received by the Company. Total Class B common shares issued and outstanding decreased by 188,474 and 3,545,408 while Class A common shares issued and outstanding increased by 188,474 and 3,545,408 for the years ended December 31, 2017 and 2016 , respectively. This is recorded as “Exchange of B shares to A shares” in the consolidated statements of changes in stockholders’ equity. Preferred Stock There are 10 million preferred shares authorized and none issued and outstanding at December 31, 2017 or 2016 . Preferred stock has a par value of $.001 . Treasury Stock During the year ended December 31, 2017 , the Company made no purchases of shares of Class A common stock. During the year ended December 31, 2016 the Company repurchased 717,115 shares of Class A common stock at a weighted average price of $33.08 per share for an aggregate amount of $23.7 million from shareholders. The Company accounted for these transactions under the cost method and held 2,886,621 common shares with a cost of $77.4 million in Treasury Stock as of December 31, 2016 .These transactions are recorded as “Treasury stock purchases” in the accompanying consolidated statements of changes in stockholders’ equity. Warrants The following table presents the activity during the year ended December 31, 2017 related to the Amended 2009 Warrants: Amended 2009 Warrants Warrants Weighted Average Exercise Price Aggregate Intrinsic Value Weighted Average Remaining Contractual Life (Years) (Dollars in thousands, except per share data) Outstanding at January 1, 2017 2,685,927 $ 26.48 Granted — — Exercised (1,411,905 ) 26.24 $ 31,895 Forfeited — — Expired — — Outstanding at December 31, 2017 1,274,022 26.75 30,640 1.87 Exercisable at December 31, 2017 1,274,022 26.75 30,640 1.87 Vested at December 31, 2017 1,274,022 26.75 30,640 1.87 Vested and expected to vest at December 31, 2017 1,274,022 26.75 30,640 1.87 As of December 31, 2017 , there were 1,274,022 outstanding Amended 2009 Warrants with an expiration date of November 12, 2019. There is no remaining expense to be recognized from the Amended 2009 Warrants.

Stock-Based Compensation and Ot

Stock-Based Compensation and Other Benefit Plans	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation and Other Benefit Plans	STOCK-BASED COMPENSATION AND OTHER BENEFIT PLANS 2009 Equity Incentive Plan In 2009, the Company approved the 2009 Equity Incentive Plan (the “2009 Option Plan”) covering its directors, employees and affiliates. The 2009 Option Plan provided for the grant of options to acquire shares of common stock up to an aggregate of the lesser of 10% of issued common stock or 4.375 million shares of common stock. When the options are exercised, the shares issued upon such exercise will be newly issued shares. In November 2014, the 2009 Option Plan expired on the fifth anniversary of plan’s adoption date. The following tables present the activity during the year ended December 31, 2017 related to the 2009 Option Plan: 2009 Option Plan Options Weighted Average Exercise Price Aggregate Intrinsic Value Weighted Average Remaining Contractual Life (Years) (Dollars in thousands, except per share data) Outstanding at January 1, 2017 3,107,235 $ 20.62 Granted — — Exercised (1,768,652 ) 20.58 $ 47,180 Forfeited (21,322 ) 22.72 Expired (2,337 ) 22.97 Outstanding at December 31, 2017 1,314,924 20.65 39,651 4.49 Exercisable at December 31, 2017 1,314,924 20.65 39,651 4.49 Vested at December 31, 2017 1,314,924 20.65 39,651 4.49 Vested and expected to vest at December 31, 2017 1,314,924 20.65 39,651 4.49 A summary of selected data related to stock-based compensation expense follows: 2009 Option Plan Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Stock-based compensation expense $ 760 $ 1,707 $ 2,239 Tax benefit realized from stock awards exercised 19,070 3,622 1,618 Fair value of stock-based awards that vested during the year 1,075 1,882 2,724 Amount of cash received from exercise of awards 36,392 11,427 8,163 Total intrinsic value of awards exercised during the year 47,180 9,547 4,940 2009 Option Plan December 31, 2017 2016 2015 (Dollars in thousands) Unrecognized compensation expense related to stock-based compensation $ — $ 569 $ 2,561 Weighted-average life over which expense is expected to be recognized (years) 0.00 0.78 1.72 2013 Stock Incentive Plan In 2013, the Company approved the 2013 Stock Incentive Plan (the “2013 Incentive Plan”) covering its executive management, directors, individual consultants and employees. The 2013 Incentive Plan provides that awards may be granted under the plan with respect to an aggregate of 3,000,000 shares of common stock of the Company. Awards may be made under the 2013 Incentive Plan in the form of (a) incentive stock options, (b) options that do not qualify as incentive stock options, (c) stock appreciation rights, (d) restricted stock, (e) restricted stock units and (f) unrestricted stock; provided, that the number of shares of restricted stock, restricted stock units, and shares of unrestricted stock awarded under the Plan shall not exceed 500,000 , in the aggregate. When the options are exercised, the shares issued upon such exercise will be newly issued shares. 2013 Incentive Plan – Stock Options On two different dates during the year ended December 31, 2015, the Company granted an aggregate of 120,500 options with a Three Year Vesting Period from the 2013 Option Plan to employees with a weighted average exercise price of $27.36 , the estimated fair value of the Company’s stock on the date of grant, and an aggregate fair value of $960 thousand . The options granted to employees expire 10 years from grant date. Also in 2015, the Company granted 129,000 options from the 2013 Option Plan to directors that vest at a rate of 25% per calendar quarter in 2015. The options have an exercise price of $23.97 , the estimated fair value of the Company’s stock on the date of grant and an aggregate fair value of $881 thousand . The options granted to directors expire 10 years from grant date. The following tables present the activity during the year ended December 31, 2017 related to the 2013 Plan Options: 2013 Plan Options Options Weighted Average Exercise Price Aggregate Intrinsic Value Weighted Average Remaining Contractual Life (Years) (Dollars in thousands, except per share data) Outstanding at January 1, 2017 2,164,258 $ 20.63 Granted — — Exercised (725,970 ) 20.18 $ 20,633 Forfeited (13,335 ) 27.23 Expired — — Outstanding at December 31, 2017 1,424,953 20.79 42,764 6.21 Exercisable at December 31, 2017 1,408,115 20.71 42,372 6.20 Vested at December 31, 2017 1,408,115 20.71 42,372 6.20 Vested and expected to vest at December 31, 2017 1,424,953 20.79 42,764 6.21 The fair value of the 2013 Plan Options granted for the years ended December 31, 2016 and 2015 were determined utilizing the Black-Scholes pricing model methodology. A summary of assumptions used to calculate the fair values of the 2013 Plan Options awards is presented below: 2013 Plan Options Years Ended December 31, 2017 2016 2015 Expected volatility — % 24.7 % 31.1 % Expected dividend yield — % 1.25 % 1.25 % Expected term (years) 0.0 6.0 6.2 Risk-free interest rate — % 1.37 % 1.63 % Weighted average grant date fair value $ — $ 6.57 $ 7.38 The expected volatility is based on the volatility of comparable peer banks. The expected term represents the period of time that the 2013 Plan Option awards are expected to be outstanding from the date of grant. The risk-free interest rate is based on the US Treasury yields for the expected term of the instrument. A summary of selected data related to stock-based compensation expense follows: 2013 Plan Options Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Stock-based compensation expense $ 226 $ 1,655 $ 2,002 Tax benefit realized from stock awards exercised 8,019 1,380 158 Grant date fair value of stock-based awards that vested during the year 3,732 4,313 1,181 Amount of cash received from exercise of option awards 14,652 5,186 714 Total intrinsic value of awards exercised during the year 20,633 3,888 465 2013 Plan Options December 31, 2017 2016 2015 (Dollars in thousands) Unrecognized compensation expense related to stock-based compensation $ 41 $ 333 $ 1,633 Weighted-average life over which expense is expected to be recognized (years) 0.28 1.24 1.53 2016 Stock Incentive Plan In 2016, the Company approved the FCB Financial Holdings, Inc. 2016 Stock Incentive Plan (the “2016 Incentive Plan”) covering its executive management, directors, individual consultants and employees. The 2016 Incentive Plan provides that awards may be granted under the plan with respect to an aggregate of 2,000,000 shares of Class A Common Stock of the Company. Awards may be made under the Plan in the form of (a) incentive stock options, (b) options that do not qualify as incentive stock options, (c) stock appreciation rights, (d) restricted stock, (e) restricted stock units and (f) unrestricted stock. Awards under the Plan may also be made in the form of performance awards by making the awards subject to the achievement of performance criteria described in the Plan or other performance criteria. An incentive stock option may be granted only to a person who is an employee of the Company or a parent or subsidiary of the Company on the date of grant. Shares issued pursuant to the Plan may be authorized but unissued Common Stock, authorized and issued Common Stock held in the Company’s treasury or Common Stock acquired by the Company for the purposes of the Plan. 2016 Incentive Plan - Stock Options In August 2016, the Company granted 827,500 options that vest in-full (i.e. cliff vesting) on the 5 -year anniversary of the grant date from the 2016 Incentive Plan to employees with an exercise price of $36.11 , the estimated fair value of the Company's stock on the date of grant and an aggregate fair value of $7.1 million . The options granted to employees expire 10 years from the grant date. On four different dates during the year ended December 31, 2017, the Company granted 37,500 options that vest in-full (i.e. cliff vesting) on the 5 -year anniversary of the grant date from the 2016 Incentive Plan to employees with a weighted average exercise price of $46.89 , the estimated fair value of the Company's stock on the date of grant and an aggregate fair value of $440 thousand . The options granted to employees expire 10 years from the grant date. The following tables present the activity during the year ended December 31, 2017 related to the 2016 Plan Options: 2016 Plan Options Options Weighted Average Exercise Price Aggregate Intrinsic Value Weighted Average Remaining Contractual Life (Years) (Dollars in thousands, except per share data) Outstanding at January 1, 2017 827,500 $ 36.11 Granted 37,500 46.89 Exercised — — $ — Forfeited (102,500 ) 36.11 Expired — — Outstanding at December 31, 2017 762,500 36.64 10,797 8.64 Exercisable at December 31, 2017 — — — — Vested at December 31, 2017 — — — — Vested and expected to vest at December 31, 2017 762,500 36.64 10,797 8.64 The fair value of the 2016 Plan Options granted for the year ended December 31, 2017 were determined utilizing the Black-Scholes pricing model methodology. A summary of assumptions used to calculate the fair values of the 2016 Plan Options awards is presented below: 2016 Plan Options December 31, 2017 2016 Expected volatility 22.6% - 23.4% 24.0 % Expected dividend yield 1.25 % 1.25 % Expected term (years) 7.5 7.5 Risk-free interest rate 2.04% - 2.17% 1.42 % Weighted average grant date fair value $ 11.73 $ 8.62 The expected volatility is based on the volatility of comparable peer banks. The expected term represents the period of time that the 2016 Plan Option awards are expected to be outstanding from the date of grant. The risk-free interest rate is based on the US Treasury yields for the expected term of the instrument. A summary of selected data related to stock-based compensation expense for the year ended December 31, 2017 are as follows: 2016 Plan Options December 31, 2017 2016 (Dollars in thousands) Stock-based compensation expense $ 1,431 $ 570 Unrecognized compensation expense related to stock-based compensation 4,882 6,563 Weighted-average life over which expense is expected to be recognized (years) 3.66 4.61 2016 Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards On March 29, 2016, the Compensation Committee granted 121,212 restricted shares (the "Award") of Class A Common Stock to certain Executives. Shareholder's approved the Plan at the 2016 Annual Meeting of Stockholders on May 16, 2016 which was determined to be the grand date of the Award. The fair value of the Awards on the grant date was $4.2 million and will be recognized as compensation expense over the requisite vesting period ending December 31, 2018. The Company recognized $1.4 million of compensation expense during the year ended December 31, 2016. On February 7, 2017, the Compensation Committee granted certain non-employee Directors of the Company a portion of their Directors' compensation for fiscal year 2017 in the form of restricted stock units (the "Directors' RSU Award"). Each RSU constitutes the right to receive from the Company on the date the RSU is settled, one share of Class A Common Stock of the Company. A total of 24,800 Directors' RSUs were granted with a grant date fair value of $1.1 million . Twenty-five percent ( 25% ) of the RSUs vested on each of March 30, 2017, June 30, 2017, September 30, 2017 and December 31, 2017. Compensation expense was recognized on a straight-line basis over the requisite vesting period ending December 31, 2017. On March 28, 2017, the Compensation Committee granted 83,593 restricted shares (the "Executive RSU Award") of Class A Common Stock to certain Executives. The fair value of the Executive RSU Awards on the grant date was $4.0 million and will be recognized as compensation expense over the requisite vesting period ending December 31, 2019. On March 28, 2017, the Compensation Committee granted a target of 73,144 and a maximum of 91,430 restricted stock units (the "Performance RSU Award") of Class A Common Stock to a certain Executive. The total target grant date fair value of the Performance RSU Award was $3.5 million , up to a maximum of $4.4 million , and will be recognized on a straight-line basis as compensation expense over the requisite vesting period ending December 31, 2019. On five different dates during the year ended December 31, 2017, the Company granted 81,815 restricted shares (the "Employee RSU Award") to employees that vest in-full (i.e. cliff vesting) on the 5 -year anniversary of the grant date from the 2016 Incentive Plan. The fair value of the Awards on the grant date was $4.1 million and will be recognized as compensation expense over the requisite vesting period ending on the respective 5 -year anniversary of the Employee RSU Award's grant date. The following tables present the activity during the year ended December 31, 2017 related to restricted stock from the 2016 Plan: 2016 Stock Incentive Plan Restricted Stock Awards Restricted Stock Unit Awards Performance Restricted Stock Unit Awards Shares Weighted Average Grant Date Fair Value Shares Weighted Average Grant Date Fair Value Shares Weighted Average Grant Date Fair Value (Dollars in thousands, except per share data) Outstanding at January 1, 2017 80,808 $ 34.47 — $ — — $ — Granted 83,593 47.85 106,615 49.49 73,144 47.85 Vested (68,268 ) 39.93 (18,600 ) 45.45 — — Canceled or forfeited — — — — — — Outstanding at December 31, 2017 96,133 42.23 88,015 50.34 73,144 47.85 The actual number of Performance Restricted Stock Units issued at the vesting date could range from 0% to 125% of the initial grant, depending on actual performance achieved. A summary of selected data related to stock-based compensation expense for the year ended December 31, 2017 are as follows: Restricted Stock Awards Restricted Stock Unit Awards Performance Restricted Stock Unit Awards December 31, December 31, December 31, 2017 2016 2017 2016 2017 2016 (Dollars in thousands) Stock-based compensation expense $ 3,672 $ 1,393 $ 1,225 $ — $ 968 $ — Unrecognized compensation expense related to stock-based compensation $ 3,113 $ 2,785 $ 4,051 $ — $ 2,532 $ — Weighted-average life over which expense is expected to be recognized (years) 1.31 2.00 4.88 0.00 2.00 0.00 Florida Community Bank, N.A. 401(k) Plan The Company sponsors the Florida Community Bank, N.A. 401(k) Plan, a tax-qualified, deferred compensation plan (the “401(k) Plan”). Under the terms of the 401(k) Plan eligible employees may contribute a portion of compensation not exceeding the limits set by law. Employees are eligible to participate in the plan after the first month following 90 days of service. The 401(k) Plan allows a matching employer contribution equal to 100% of elective deferrals that do not exceed 3% of compensation. Matching contributions are fully vested after three years of service. Total 401(k) matching employer contribution expense totaled $1.1 million , $978 thousand and $868 thousand for the years ended December 31, 2017 , 2016 and 2015 respectively. Executive Incentive Plan During the year ended December 31, 2015, the Compensation Committee of the Board of Directors of the Company approved the adoption of the FCB Financial Holdings, Inc. Executive Incentive Plan (the “EIP”). The EIP provides for Annual Incentive Awards and Long-Term Incentive Awards, both of which are subject to achievement of specified performance goals. Annual Incentive Awards- The Compensation Committee approved Annual Awards under the EIP in respect to the Company’s Core Pre-Tax Profits for fiscal years 2017 , 2016 and 2015 . The Company recognized $6.0 million , $6.0 million , and $5.1 million of compensation expense for the years ended December 31, 2017 , 2016 and 2015 , respectively. Long-Term Incentive Awards- The Compensation Committee granted a Long-Term Award of cash phantom units (“CPUs”) under the Long-Term Incentive component of the EIP which covers a three -year period ending December 31, 2017 (the “Performance Period”). The value of the award is determined by the Company’s common share price at the end of the performance period. Based on the estimated value of the award, the Company recognized $105 thousand , $377 thousand and $1.1 million of compensation expense for the years ended December 31, 2017 , 2016 and 2015 respectively. On January 2, 2018, upon conclusion of the Performance Period, it was determined by the Compensation Committee that the total award to be settled under this Long-Term Award plan be 103,456 shares of Class A Common Stock of the Company. Management Long-Term Incentive Plan During the year ended December 31, 2015, the Compensation Committee of the Board of Directors of the Company approved the FCB Financial Holdings, Inc. Management Long-Term Incentive Plan (“MLTIP”) for certain employees of the Company. The MLTIP provides participants the opportunity to receive a cash award that may be adjusted for the Company’s performance over a three year period ending on December 31, 2018. The estimated award amount will be recognized over the three year service period beginning on January 1, 2016. The Company recognized $792 thousand and $1.1 million in compensation expense related to this plan for the years ended December 31, 2017 and 2016 , respectively.

Basic and Diluted Earnings Per

Basic and Diluted Earnings Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Basic and Diluted Earnings Per Share	BASIC AND DILUTED EARNINGS PER SHARE Basic EPS is calculated by dividing net income available to common stockholders by the weighted average number of common shares outstanding during the period. Diluted EPS reflects the effect of common stock equivalents, including stock options, warrants and unvested shares, calculated using the treasury stock method. Common stock equivalents are excluded from the computation of diluted EPS in periods in which the effect is anti-dilutive. The following table presents the computation of basic and diluted EPS: Years Ended December 31, 2017 2016 2015 (Dollars in thousands, except share and per share data) Net income available to common stockholders $ 125,194 $ 99,916 $ 53,391 Weighted average number of common shares—basic 42,887,142 40,716,588 41,300,979 Effect of dilutive securities: Employee stock-based compensation awards and warrants 3,233,788 2,508,576 1,992,628 Weighted average number of common shares—diluted 46,120,930 43,225,164 43,293,607 Basic earnings per share $ 2.92 $ 2.45 $ 1.29 Diluted earnings per share $ 2.71 $ 2.31 $ 1.23 Weighted average number of anti-dilutive equity awards 29,114 330,095 91,923

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (the "TCJA") resulted in significant changes to the U.S. tax code, including a reduction in the maximum federal corporate income tax rate from 35% to 21%, effective January 1, 2018. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income at the time of enactment of such change in tax rates. Accordingly, the Company was required to revalue its deferred tax assets and deferred tax liabilities to account for the future impact of lower corporate tax rates on these deferred amounts. The Company performed a preliminary analysis as of December 31, 2017 and recorded an estimated $14.3 million impact for this one-time non-cash charge to the statement of income. The ultimate impact may differ from this estimate due to, among other things, additional analysis, changes in interpretations and assumptions the Company has made, additional regulatory guidance that may be issued, and actions the Company may take as a result of the TCJA. The components of the expense and benefit for income taxes for the periods presented are as follows: Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Current income tax expense: Federal $ 24,036 $ 39,528 $ 23,610 State 3,800 6,013 3,441 Total current income tax expense 27,836 45,541 27,051 Deferred income tax expense (benefit): Federal 24,795 9,161 (19,157 ) State 1,534 1,203 (2,238 ) Total deferred income tax expense (benefit) 26,329 10,364 (21,395 ) Total income tax expense (benefit) $ 54,165 $ 55,905 $ 5,656 A reconciliation of the expected income tax expense or benefit at the statutory federal income tax rate of 35% to the Company’s actual income tax expense or benefit and effective tax rate for the periods presented is as follows: Years Ended December 31, 2017 2016 2015 Amount % Amount % Amount % (Dollars in thousands) Tax expense (benefit) at federal income tax rate $ 62,776 35.00 % $ 54,537 35.00 % $ 20,667 35.00 % Increase (decrease) resulting from: Bank-owned life insurance (3,186 ) (1.78 )% (1,817 ) (1.17 )% (1,614 ) (2.73 )% Stock compensation and excess tax benefit (20,098 ) (11.21 )% 234 0.15 % 729 1.23 % Dividends received deduction (1,631 ) (0.91 )% (1,919 ) (1.23 )% (2,104 ) (3.56 )% GFB NUBIL Revaluation — — % — — % (4,954 ) (8.39 )% NOL Valuation Allowance — — % — — % (9,061 ) (15.35 )% State tax, net of federal benefit 3,528 1.97 % 4,777 3.07 % 1,619 2.74 % Federal tax rate change 14,301 7.97 % — — % — — % Other (1,525 ) (0.85 )% 93 0.06 % 374 0.62 % Total $ 54,165 30.19 % $ 55,905 35.88 % $ 5,656 9.56 % Deferred income tax assets and liabilities reflect the tax effect of estimated temporary differences between the carrying amount of assets and liabilities for financial reporting purposes and the amounts used for the same items for income tax reporting purposes. The significant components of the net deferred tax assets and liabilities for the periods presented are as follows: December 31, 2017 2016 (Dollars in thousands) Deferred tax assets: Excess tax basis over carrying value of assets: Other real estate owned $ 1,456 $ 12,991 Total 1,456 12,991 Excess carrying value over tax basis of liabilities: Repo Loans — 324 Total — 324 Net operating loss carry forward: Federal 5,755 9,287 State 534 921 Total 6,289 10,208 Amortization 11,717 21,555 Depreciation — 660 Unrealized losses on securities available for sale — 2,509 Allowance for loan losses 11,087 12,807 Non-qualified stock options and restricted stock 3,869 7,695 Other 469 2,696 Gross deferred tax assets 34,887 71,445 Valuation allowance — — Gross deferred tax assets, net of valuation allowance 34,887 71,445 Deferred tax liabilities: Loans (947 ) (7,542 ) Depreciation (239 ) — Restricted securities (1,475 ) (2,260 ) Unrealized gains on securities available for sale (3,594 ) — Other (1,589 ) (252 ) Gross deferred tax liabilities (7,844 ) (10,054 ) Deferred tax assets (liabilities), net $ 27,043 $ 61,391 At December 31, 2017 , the Company had deferred tax assets for federal and state net operating losses of $5.8 million and $534 thousand , respectively. The federal and state net operating loss carryforwards are attributable to the acquisition of Great Florida Bank and are subject to an annual limitation. These deferred tax assets for net operating losses will expire in years 2028 through 2034 . The Company records a valuation allowance to reduce its deferred tax assets if, based on the weight of available evidence, both positive and negative, for each respective tax jurisdiction, it is more likely than not that some portion or all of such deferred tax assets will not be realized. Management believes the Company will realize the benefits from certain federal and state net operating loss carryforwards and as such, in 2015, reversed the valuation allowance of $9.1 million previously provided on the deferred tax assets for federal and state net operating loss carryforwards. The reversal of the valuation allowance on the deferred tax assets was recognized as a reduction of income tax expense. The Company is subject to U.S. federal income tax as well as state income tax for Florida and New York. The Company had no uncertain tax positions at December 31, 2017, 2016 or 2015. The Company’s policy is to classify interest and penalties associated with income taxes within other expenses. The Company did not incur interest or penalties associated with income taxes at December 31, 2017, 2016 or 2015.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES The Company issues off-balance sheet financial instruments in connection with its lending activities and to meet the financing needs of its customers. These financial instruments include commitments to fund loans and lines of credit as well as commercial and standby letters of credit. These commitments expose the Company to varying degrees of credit and market risk which are essentially the same as those involved in extending loans to customers. The Company follows the same credit policies in making commitments as it does for instruments recorded on the Company’s consolidated balance sheet. Collateral is obtained based on management’s assessment of the customer’s credit risk. The Company’s exposure to credit loss is represented by the contractual amount of these commitments. The Company’s reserve for unfunded commitments totaled $1.1 million as of December 31, 2017 and $1.6 million as of December 31, 2016 . Fees collected on off-balance sheet financial instruments represent the fair value of those commitments and are deferred and amortized over their term. Financial Instruments Commitments Unfunded commitments are as follows: December 31, 2017 2016 (Dollars in thousands) Commitments to fund loans $ 926,405 $ 724,380 Unused lines of credit 571,587 410,068 Commercial and standby letters of credit 46,520 26,200 Total $ 1,544,512 $ 1,160,648 Commitments to fund loans: Commitments to fund loans are agreements to lend funds to customers as long as there is no violation of any condition established in the contract. To accommodate the financial needs of customers, the Company makes commitments under various terms to lend funds to consumers and businesses. Commitments to fund loans generally have fixed expiration dates or other termination clauses and may require payment of a fee. Many of these commitments are expected to expire without being funded and, therefore, the total commitment amounts do not necessarily represent future liquidity requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. The amount of collateral required in connection with a commitment to fund is based on management’s credit evaluation of the counterparty. Unused lines of credit: Unfunded commitments under lines of credit include commercial, commercial real estate, home equity and consumer lines of credit to existing customers. Some of these commitments may mature without being fully funded. Commercial and standby letters of credit: Letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. Letters of credit are primarily issued to support trade transactions or guarantee arrangements. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. The Company generally holds collateral supporting those commitments if deemed necessary. Other Commitments and Contingencies Legal Proceedings The Company, from time to time, is involved as plaintiff or defendant in various legal actions arising in the normal course of business. While the ultimate outcome of any such proceedings cannot be predicted with certainty, it is the opinion of management, based upon advice of legal counsel, that no proceedings exist, either individually or in the aggregate, which, if determined adversely to the Company, would have a material effect on the Company’s consolidated balance sheet, results of operations or cash flows.

Parent Company Financial Statem

Parent Company Financial Statements	12 Months Ended
	Dec. 31, 2017
Parent company
Parent Company Financial Statements	PARENT COMPANY FINANCIAL STATEMENTS Condensed Balance Sheets of FCB Financial Holdings, Inc. (Parent company only) for the periods presented are as follows: PARENT COMPANY CONDENSED BALANCE SHEETS December 31, 2017 2016 (Dollars in thousands) Assets: Cash and due from banks $ 10,271 $ 18,126 Available for sale securities 179,815 129,970 Investment in bank subsidiary 1,025,677 885,296 Other assets 13,894 9,874 Total assets $ 1,229,657 $ 1,043,266 Liabilities and stockholders’ equity: Total liabilities 50,783 61,182 Stockholders’ equity 1,178,874 982,084 Total liabilities and stockholders’ equity $ 1,229,657 $ 1,043,266 Condensed Statements of Income of FCB Financial Holdings, Inc. (Parent company only) for the periods presented are as follows: PARENT COMPANY CONDENSED STATEMENTS OF INCOME Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Income: Interest and dividends on investment securities $ 8,079 $ 7,831 $ 8,602 Gain (loss) on investment securities 2,032 (586 ) 688 Total income 10,111 7,245 9,290 Expense: Interest on borrowings 770 884 551 Stock-based compensation expense 1,126 577 829 Professional services 922 707 950 Directors fees 401 800 598 Insurance expense 768 1,034 1,505 Other noninterest expense 8,372 7,261 6,500 Total expense 12,359 11,263 10,933 Income (loss) before income taxes and equity in undistributed income of subsidiaries (2,248 ) (4,018 ) (1,643 ) Income tax expense (benefit) (5,494 ) (3,671 ) (2,901 ) Income (loss) before equity in undistributed income of subsidiaries 3,246 (347 ) 1,258 Equity in income of subsidiary 121,948 100,263 52,133 Net income $ 125,194 $ 99,916 $ 53,391 Condensed Statements of Comprehensive Income of FCB Financial Holdings, Inc. (Parent company only) for periods presented are as follows: PARENT COMPANY CONDENSED STATEMENTS OF COMPREHENSIVE INCOME Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Net income $ 125,194 $ 99,916 $ 53,391 Other comprehensive income (loss): Unrealized net holding gains (losses) on investment securities available for sale, net of taxes of $(1,644), $(620), and $(227), respectively 2,685 988 362 Reclassification adjustment for (gains) losses on investment securities available for sale included in net income, net of taxes of $1,050, $63, and $384, respectively (1,696 ) (100 ) (612 ) Total other comprehensive income (loss) 989 888 (250 ) Total comprehensive income $ 126,183 $ 100,804 $ 53,141 Condensed Statements of Cash Flows of FCB Financial Holdings, Inc. (Parent company only) for periods presented are as follows: PARENT COMPANY CONDENSED STATEMENTS OF CASH FLOWS Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Cash flows from operating activities: Net income $ 125,194 $ 99,916 $ 53,391 Adjustments to reconcile net income to net cash used in operating activities: Equity in earnings of subsidiaries (121,948 ) (100,263 ) (52,133 ) Amortization (accretion) of premium (discount) on investment securities (13 ) — — (Gain) loss on investment securities (2,032 ) 586 (688 ) Stock-based compensation and warrant expense 1,124 577 829 Depreciation of premises and equipment — — 1 Deferred tax expense 3,126 (735 ) 1,272 Net change in operating assets and liabilities: (Increase)/decrease in due from subsidiaries (472 ) 4,478 8,476 Increase/(decrease) in due to subsidiaries (1,745 ) 1,745 (1,979 ) Net change in other assets 1,332 1,382 1,052 Net change in other liabilities (8,109 ) (4,365 ) (2,806 ) Net cash provided by (used in) operating activities (3,543 ) 3,321 7,415 Cash flows from investing activities: Purchases of investment securities available for sale (102,988 ) (67,934 ) (169,728 ) Sales of investment securities available for sale 56,791 106,347 110,649 Payments and maturities of investment securities — — 2,005 Capital contribution — — (35,000 ) Net cash provided by (used in) investing activities (46,197 ) 38,413 (92,074 ) Cash flows from financing activities: Repurchase common stock — (23,738 ) (34,884 ) Exercise of stock options 50,670 17,042 8,793 Excess tax benefit from share-based payments — 2,110 2,048 Net change in repurchase agreements (8,785 ) (28,134 ) 87,254 Net cash provided by (used in) financing activities 41,885 (32,720 ) 63,211 Net Change in Cash (7,855 ) 9,014 (21,448 ) Cash at Beginning of Period 18,126 9,112 30,560 Cash at End of Period $ 10,271 $ 18,126 $ 9,112

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS When determining the fair value measurements for assets and liabilities and the related fair value hierarchy, the Company considers the principal or most advantageous market in which it would transact and the assumptions that market participants would use when pricing the asset or liability. When possible, the Company looks to active and observable markets to price identical assets or liabilities. When identical assets and liabilities are not traded in active markets, the Company looks to market observable data for similar assets and liabilities. It is the Company’s policy to maximize the use of observable inputs, minimize the use of unobservable inputs and use unobservable inputs to measure fair value to the extent that observable inputs are not available. The need to use unobservable inputs generally results from the lack of market liquidity, resulting in diminished observability of both actual trades and assumptions that would otherwise be available to value instruments, or the value of underlying collateral is not market observable. Although third party price indications may be available for an asset or liability, limited trading activity would make it difficult to support the observability of these quotations. Financial Instruments Carried at Fair Value on a Recurring Basis The following is a description of the valuation methodologies used for financial instruments measured at fair value on a recurring basis, as well as the general classification of each instrument under the valuation hierarchy. Investment Securities—Investment securities available for sale are carried at fair value on a recurring basis. When available, fair value is based on quoted prices for the identical security in an active market and as such, would be classified as Level 1. If quoted market prices are not available, fair values are estimated using quoted prices of securities with similar characteristics, discounted cash flows or matrix pricing models. Investment securities available for sale for which Level 1 valuations are not available are classified as Level 2 if the valuation incorporates primarily observable inputs. Level 2 securities include U.S. Government agencies and sponsored enterprises obligations and agency mortgage-backed securities; state and municipal obligations; asset-backed securities; and corporate debt and other securities. Pricing of these securities is generally spread driven. Observable inputs that may impact the valuation of these securities include benchmark yield curves, credit spreads, reported trades, dealer quotes, bids, issuer spreads, current rating, historical constant prepayment rates, historical voluntary prepayment rates, structural and waterfall features of individual securities, published collateral data, and for certain securities, historical constant default rates and default severities. Interest Rate Derivatives—Interest rate derivatives are reported at estimated fair value utilizing Level 2 inputs and are included in other assets and other liabilities and consist of interest rate swaps and caps where there is no significant deterioration in the counterparties (loan customers) credit risk since origination of the interest rate swap or cap. The Company values its interest rate swap and cap positions using market prices provided by a third party which uses primarily observable market inputs. Interest rate derivatives are further described in Note 8 “Derivatives.” For purposes of potential valuation adjustments to our derivative positions, the Company evaluates the credit risk of its counterparties as well as its own credit risk. Accordingly, the Company has considered factors such as the likelihood of default, expected loss given default, net exposures and remaining contractual life, among other things, in determining if any estimated fair value adjustments related to credit risk are required. The Company reviews counterparty exposure quarterly, and when necessary, appropriate adjustments are made to reflect the exposure. For the years ended December 31, 2017 , 2016 or 2015 , the Company has not realized any losses due to a counterparty’s inability to pay any net uncollateralized position. As of December 31, 2017 , there were no interest rate derivatives classified as Level 3. Clawback liability—The fair value of the FDIC clawback liability was estimated using a discounted cash flow technique based on projected cash flows related to the resolution of Covered Assets and a discount rate using a risk free rate, plus a premium that took into account the Company’s credit risk, resulting in Level 3 classification. On March 4, 2015, the Bank entered into an agreement with the FDIC to terminate all loss sharing agreements which were entered into in 2010 and 2011 in conjunction with the Bank’s acquisition of substantially all of the assets and assumption of substantially all of the liabilities of six failed banks in FDIC-assisted acquisitions. Under the early termination, all rights and obligations of the Bank and the FDIC under the loss share agreements, including the clawback liability, have been eliminated. The following table presents the assets and liabilities measured at fair value on a recurring basis: December 31, 2017 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: U.S. Government agencies and sponsored enterprises obligations $ — $ 42,838 $ — $ 42,838 U.S. Government agencies and sponsored enterprises mortgage-backed securities — 595,237 — 595,237 State and municipal obligations — 26,172 — 26,172 Asset-backed securities — 610,546 — 610,546 Corporate bonds and other debt securities 55,970 699,933 — 755,903 Preferred stocks and other equity securities 12,954 77,153 — 90,107 Derivative assets—Interest rate contracts 11,833 — 11,833 Total $ 68,924 $ 2,063,712 $ — $ 2,132,636 Liabilities: Derivative liabilities—Interest rate contracts $ — $ 11,833 $ — $ 11,833 Total $ — $ 11,833 $ — $ 11,833 December 31, 2016 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: U.S. Government agencies and sponsored enterprises obligations $ — $ 16,314 $ — $ 16,314 U.S. Government agencies and sponsored enterprises mortgage-backed securities — 558,446 — 558,446 State and municipal obligations — 27,679 — 27,679 Asset-backed securities — 577,823 — 577,823 Corporate bonds and other debt securities 53,517 505,777 — 559,294 Preferred stocks and other equity securities 6,908 129,970 — 136,878 Derivative assets—Interest rate contracts — 15,268 — 15,268 Total $ 60,425 $ 1,831,277 $ — $ 1,891,702 Liabilities: Derivative liabilities—Interest rate contracts $ — $ 15,268 $ — $ 15,268 Total $ — $ 15,268 $ — $ 15,268 The Company's policy is to recognize transfers into or out of a level of the fair value hierarchy as of the end of the reporting period. There were no financial assets transferred from level 2 to level 1 of the fair value hierarchy during the year ended December 31, 2017 . There were $53.5 million of transfers of financial assets between levels of the fair value hierarchy during the year ended December 31, 2016 . The following table reconciles changes in the fair value of liabilities measured at fair value on a recurring basis and classified in level 3 of the fair value hierarchy for the periods presented: Years Ended December 31, 2017 2016 2015 Clawback Liability Clawback Liability Clawback Liability (Dollars in thousands) Balance at beginning of period $ — $ — $ 13,846 Termination of FDIC loss sharing agreements — — (13,846 ) Balance at end of period $ — $ — $ — For the years ended December 31, 2017 and 2016 , there was not a change in the methods or significant assumptions used to estimate fair value. Financial Instruments Measured at Fair Value on a Non-Recurring Basis The following is a description of the methodologies used to estimate the fair values of assets and liabilities measured at fair value on a non-recurring basis, and the level within the fair value hierarchy in which those measurements are typically classified. Impaired loans and OREO—The carrying amount of collateral dependent impaired loans is typically based on the fair value of the underlying collateral, which may be real estate or other business assets, less estimated costs to sell. The carrying value of OREO is initially measured based on the fair value, less estimated cost to sell, of the real estate acquired in foreclosure and subsequently adjusted to the lower of cost or estimated fair value, less estimated cost to sell. Fair values of real estate collateral are typically based on real estate appraisals which utilize market and income valuation techniques incorporating both observable and unobservable inputs. When current appraisals are not available, the Company may use brokers’ price opinions, home price indices, or other available information about changes in real estate market conditions to adjust the latest appraised value available. These adjustments to appraised values may be subjective and involve significant management judgment. The fair value of collateral consisting of other business assets is generally based on appraisals that use market approaches to valuation, incorporating primarily unobservable inputs. Fair value measurements related to collateral dependent impaired loans and OREO are classified within level 3 of the fair value hierarchy. The following table shows significant unobservable inputs used in the non-recurring fair value measurement of level 3 assets and liabilities: Level 3 Assets: December 31, 2017 December 31, 2016 Valuation Technique Unobservable Inputs Range (Weighted Average) (Dollars in thousands) Impaired loans $ 6,153 $ 8,878 Third party appraisals and discounted cash flows Collateral discounts and discount rates 0% - 100% (7.6%) Other real estate owned 14,906 19,228 Third party appraisals Collateral discounts and estimated cost to sell 10 % The following table provides information about certain assets measured at fair value on a non-recurring basis: Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Negative valuation adjustments: Impaired loans $ — $ 700 $ 1,071 Foreclosed real estate 670 1,219 674 Impairment charges resulting from the non-recurring changes in fair value of underlying collateral of impaired loans are included in the provision for loan losses in the consolidated statement of income. Impairment charges resulting from the non-recurring changes in fair value of OREO are included in other real estate and acquired assets resolution expenses in the consolidated statement of income. The carrying amounts and estimated fair values, as well as the level within the fair value hierarchy, of the Company’s financial instruments are as follows: December 31, 2017 Carrying Value Fair Value Level 1 Level 2 Level 3 (Dollars in thousands) Financial Assets: Cash and cash equivalents $ 115,921 $ 115,921 $ 115,921 $ — $ — Available for sale securities 2,120,803 2,120,803 68,924 2,051,879 — FHLB and other bank stock 56,881 56,881 — 56,881 — Loans, net 7,930,639 7,877,094 — — 7,877,094 Loans held for sale 12,736 12,736 — 12,736 — Bank-owned life insurance 201,069 201,069 — 201,069 — Derivative assets—Interest rate contracts 11,833 11,833 — 11,833 — Financial Liabilities: Deposits $ 8,673,927 $ 8,664,125 $ — $ 8,664,125 $ — Advances from the FHLB and other borrowings 749,113 740,941 — 740,941 — Derivative liabilities—Interest rate contracts 11,833 11,833 — 11,833 — December 31, 2016 Carrying Value Fair Value Level 1 Level 2 Level 3 (Dollars in thousands) Financial Assets: Cash and cash equivalents $ 83,876 $ 83,876 $ 83,876 $ — $ — Available for sale securities 1,876,434 1,876,434 60,425 1,816,009 — FHLB and other bank stock 51,656 51,656 — 51,656 — Loans, net 6,596,997 6,556,914 — — 6,556,914 Loans held for sale 20,220 20,220 — 20,220 — Bank-owned life insurance 198,438 198,438 — 198,438 — Derivative assets—Interest rate contracts 15,268 15,268 — 15,268 — Financial Liabilities: Deposits $ 7,305,671 $ 7,306,148 $ — $ 7,306,148 $ — Advances from the FHLB and other borrowings 751,103 745,855 — 745,855 — Derivative liabilities—Interest rate contracts 15,268 15,268 — 15,268 — Certain financial instruments are carried at amounts that approximate fair value due to their short-term nature and generally negligible credit risk. Financial instruments for which fair value approximates the carrying amount at December 31, 2017 and 2016 , include cash and cash equivalents. The following methods and assumptions were used to estimate the fair value of each class of financial instruments. Estimates may differ from actual exit value as defined by ASC Topic 820. FHLB and Other Bank Stock: FHLB and other bank stock can be liquidated only by redemption by the issuer, as there is no market for these securities. These securities are carried at par, which has historically represented the redemption price and is therefore considered to approximate fair value. Loans: Fair values for loans are based on a discounted cash flow methodology that considers various factors, including the type of loan and related collateral, classification status, fixed or variable interest rate, term of loan, whether or not the loan was amortizing and current discount rates. Loans are grouped together according to similar characteristics and are treated in the aggregate when applying various valuation techniques. The discount rates used for loans are based on current market rates for new originations of comparable credit risk and include adjustments for liquidity concerns. The ALL is considered a reasonable estimate of the required adjustment to fair value to reflect the impact of credit risk. Loans Held for Sale: Fair values of mortgage loans held for sale are based on commitments on hand from investors or prevailing market prices. Bank-owned Life Insurance: The Company holds life insurance policies on certain officers. The carrying value of these policies approximates fair value as it is based on the cash surrender value adjusted for other charges or amounts due that are probable at settlement. Deposits: The fair value of demand deposits, savings accounts and money market deposits is the amount payable on demand at the reporting date. The fair value of fixed-maturity certificates of deposit is estimated using discounted cash flow analysis and using the rates currently offered for deposits of similar remaining maturities. Advances from the FHLB and Other Borrowings: The fair value of advances from the FHLB and other borrowings are estimated by discounting the future cash flows using the current rate at which similar borrowings with similar remaining maturities could be obtained.

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) The summary quarterly financial information set forth below for each of the last eight quarters has been derived from the Company’s unaudited interim consolidated financial statements and other financial information. The summary historical quarterly financial information includes all adjustments consisting of normal recurring accruals that the Company considers necessary for a fair presentation of the financial position and the results of operations for these periods. The information below is only a summary and should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and the consolidated historical financial statements and the related notes thereto included in this Form 10-K filing. Quarters Ended December 31, 2017 Q4 Q3 Q2 Q1 (Dollars in thousands, except per share data) Selected Income Statement data: Interest income $ 101,490 $ 96,816 $ 90,573 $ 85,222 Interest expense 23,376 21,035 18,686 15,552 Net interest income 78,114 75,781 71,887 69,670 Provision for loan losses 2,786 2,871 2,115 1,643 Net interest income after provision for loan losses 75,328 72,910 69,772 68,027 Noninterest income 7,731 8,425 8,873 9,987 Noninterest expense 36,119 35,239 35,252 35,084 Income before income tax expense 46,940 46,096 43,393 42,930 Income tax expense 27,976 13,936 8,312 3,941 Net income $ 18,964 $ 32,160 $ 35,081 $ 38,989 Earnings per share: Basic $ 0.43 $ 0.74 $ 0.82 $ 0.93 Diluted $ 0.41 $ 0.70 $ 0.76 $ 0.86 Quarters Ended December 31, 2016 Q4 Q3 Q2 Q1 (Dollars in thousands, except per share data) Selected Income Statement data: Interest income $ 85,580 $ 80,800 $ 77,208 $ 75,728 Interest expense 14,514 13,522 12,278 11,286 Net interest income 71,066 67,278 64,930 64,442 Provision for loan losses 2,249 1,990 1,976 1,440 Net interest income after provision for loan losses 68,817 65,288 62,954 63,002 Noninterest income 7,919 8,142 8,222 5,434 Noninterest expense 33,646 33,036 33,975 33,300 Income before income tax expense 43,090 40,394 37,201 35,136 Income tax expense 15,194 14,330 13,697 12,684 Net income $ 27,896 $ 26,064 $ 23,504 $ 22,452 Earnings per share: Basic $ 0.68 $ 0.64 $ 0.58 $ 0.55 Diluted $ 0.64 $ 0.60 $ 0.55 $ 0.52

Subsequent Events Subsequent Ev

Subsequent Events Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS Acquisitions Floridian Community Bank On November 27, 2017, the Company announced the signing of a definitive agreement for FCB Financial Holdings, Inc. to acquire Floridian Community Holdings, Inc., the parent company of Floridian Community Bank (“Floridian”). On February 5, 2018, the Company announced it had received approval from both the Federal Reserve Bank of Atlanta and the Office of the Comptroller of the Currency of its applications for the acquisition of Floridian. On February 20, 2018, Floridian shareholders approved the merger. Floridian, founded in 2003, is a state-chartered bank with 5 full-service branches located in South Florida. Under the terms of the merger agreement, which has been unanimously approved by the Board of each company, the transaction is expected to close in March of 2018, subject to certain customary closing conditions.

Summary of Significant Accoun29

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations FCB Financial Holdings, Inc. (the “Company”) is a national bank holding company with one wholly-owned national bank subsidiary, Florida Community Bank, N.A. (“Florida Community Bank” or the “Bank”), headquartered in Weston, Florida, offering a comprehensive range of traditional banking products and services to individual and corporate customers through 46 banking centers located in Florida at December 31, 2017 .
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company, its wholly-owned subsidiary, the Bank, and the Bank’s subsidiaries, which consist of a group of real estate holding companies. Intercompany transactions and balances have been eliminated in consolidation.
Use of Estimates	Use of Estimates The Company’s financial reporting and accounting policies conform to U.S. GAAP. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates subject to significant change include the allowance for loan losses, valuation of and accounting for acquired loans, the carrying value of OREO, the fair value of financial instruments, the valuation of goodwill and other intangible assets, acquisition-related fair value computations, stock-based compensation and deferred taxes.
Business Combinations	Business combinations The Company accounts for transactions that meet the definition of a purchase business combination by recording the assets acquired and liabilities assumed at their fair value upon acquisition. The operations of the acquisitions are included in the consolidated financial statements from the date of acquisition. Intangible assets, indemnification contracts and contingent consideration are identified and recognized individually. If the fair value of the assets acquired exceeds the purchase price plus the fair value of the liabilities assumed, a bargain purchase gain is recognized. Conversely, if the purchase price plus the fair value of the liabilities assumed exceeds the fair value of the assets acquired, goodwill is recognized. The Company’s assumptions utilized to determine the fair value of assets acquired and liabilities assumed conform to market conditions at the date of acquisition. The provisional amounts recorded are updated if better information is obtained about the initial assumptions used to determine fair value or if new information is obtained regarding the facts and circumstances that existed at the date of acquisition. The provisional amounts may be adjusted through the completion of the measurement period, which does not exceed one year from the date of acquisition.
Fair Value Measurement	Fair Value Measurement The Company uses estimates of fair value in applying various accounting standards for its consolidated financial statements on either a recurring or non-recurring basis. Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between willing and able market participants. The Company groups its assets and liabilities measured at fair value in three hierarchy levels, based on the observability and transparency of the inputs. These levels are as follows: Level 1—Unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets or liabilities; Level 2—Observable inputs other than level 1 inputs, including quoted prices for similar assets and liabilities, quoted prices for identical assets and liabilities in less active markets and other inputs that can be corroborated by observable market data; Level 3—Unobservable inputs supported by limited or no market activity or data and inputs requiring significant management judgment or estimation; valuation techniques utilizing level 3 inputs include option pricing models, discounted cash flow models and similar techniques. It is the Company’s policy to maximize the use of observable inputs and minimize the use of unobservable inputs in estimating fair value. Unobservable inputs are utilized in determining fair value estimates only to the extent that observable inputs are not available. The need to use unobservable inputs generally results from a lack of market liquidity and trading volume. Transfers between levels of fair value hierarchy are recorded at the end of the reporting period. Accounting Standards Codification (“ASC”) Topic 825, Financial Instruments, allows the Company an irrevocable option for measurement of eligible financial assets or financial liabilities at fair value on an instrument by instrument basis (the fair value option). An election may be made at the time an eligible financial asset, financial liability or firm commitment is recognized or when certain specified reconsideration events occur. The Company has not elected the fair value option for any eligible financial instrument as of December 31, 2017 or 2016 .
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. A gain or loss is recognized in earnings upon completion of the sale based on the difference between the sales proceeds and the carrying value of the assets. Control over the transferred assets is deemed to have been surrendered when the assets have been isolated from the Company, the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets and the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity.
Cash and Cash Equivalents/ Restrictions on Cash	Cash and Cash Equivalents Cash and cash equivalents include cash and due from banks, interest-bearing deposits with banks, Federal funds sold and securities purchased under resale agreements or similar arrangements. Cash and cash equivalents have original maturities of three months or less . Accordingly, the carrying amount of such instruments is considered a reasonable estimate of fair value. Restrictions on Cash The Bank is required to maintain reserve balances with the FRB. Such reserve requirements are based on a percentage of deposit liabilities and may be satisfied by cash on hand or on deposit. Because the amount of cash on hand exceeded the requirement, there was no reserve with the FRB as of December 31, 2017 or 2016 .
Investment Securities	Investment Securities Securities transactions are recorded on the trade date basis. The Company determines the classification of investment securities at the time of purchase. If the Company has the intent and the ability at the time of purchase to hold debt securities until maturity, they are classified as held-to-maturity. Investment securities held-to-maturity are stated at amortized cost. Debt securities the Company does not intend to hold to maturity are classified as available for sale and carried at estimated fair value with unrealized gains or losses reported as a separate component of stockholders’ equity in accumulated other comprehensive income, net of applicable income taxes. Available for sale securities are a part of the Company’s asset/liability management strategy and may be sold in response to changes in interest rates, prepayment risk or other market factors. Interest income and dividends on securities are recognized in interest income on an accrual basis. Premiums and discounts on debt securities are amortized as an adjustment to interest income over the period to maturity of the related security using the effective interest method. Realized gains or losses on the sale of securities are determined using the specific identification method. The Company reviews investment securities for impairment on a quarterly basis or more frequently if events and circumstances warrant. In order to determine if a decline in fair value below amortized cost represents other-than-temporary impairment ("OTTI"), management considers several factors, including but not limited to, the length of time and extent to which the fair value has been less than the amortized cost basis, the financial condition and near-term prospects of the issuer (considering factors such as adverse conditions specific to the issuer and the security and ratings agency actions) and the Company’s intent and ability to retain the investment in order to allow for an anticipated recovery in fair value. The Company recognizes OTTI of a debt security for which there has been a decline in fair value below amortized cost if (i) management intends to sell the security, (ii) it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis, or (iii) the Company does not expect to recover the entire amortized cost basis of the security. The amount by which amortized cost exceeds the fair value of a debt security that is considered to have OTTI is separated into a component representing the credit loss, which is recognized in earnings, and a component related to all other factors, which is recognized in other comprehensive income. The measurement of the credit loss component is equal to the difference between the debt security’s amortized cost basis and the present value of its expected future cash flows discounted at the security’s effective yield. If the Company intends to sell the security, or if it is more likely than not it will be required to sell the security before recovery, an OTTI write-down is recognized in earnings equal to the entire difference between the amortized cost basis and fair value of the security. The Bank, as a member of the FHLB is required to maintain an investment in the stock of the FHLB. No market exists for this stock, and the Bank’s investment can be liquidated only through redemption by the FHLB, at the discretion of and subject to conditions imposed by the FHLB. Historically, FHLB stock redemptions have been at cost (par value), which equals the Company’s carrying value. The Company monitors its investment in FHLB stock for impairment through review of recent financial results of the FHLB including capital adequacy and liquidity position, dividend payment history, redemption history and information from credit agencies. The Company has not identified any indicators of impairment of FHLB stock.
Loans	Loans The Company’s accounting methods for loans differ depending on whether the loans are new (“New” loans) or acquired (“Acquired” loans), and for acquired loans, whether the loans were acquired at a discount as a result of credit deterioration since the date of origination.
New Loans	New Loans The Company accounts for originated loans and purchased loans not acquired through business acquisitions as New loans. New loans that management has the intent and ability to hold for the foreseeable future are reported at their outstanding principal balances net of any allowance for loan losses, unamortized deferred fees and costs and unamortized premiums or discounts. The net amount of nonrefundable loan origination fees and certain direct costs associated with the lending process are deferred and amortized into interest income over the contractual lives of the New loans using methods which approximate the effective yield method. Discounts and premiums are amortized or accreted into interest income over the estimated term of the New loans using methods that approximate the effective yield method. Interest income on New loans is accrued based on the unpaid principal balance outstanding and the contractual terms of the loan agreements.
Acquired Loans	Acquired Loans Acquired loans are accounted for under ASC 310-30 unless the loan type is excluded from the scope of ASC 310-30 (i.e. loans where borrowers have revolving privileges at acquisition date, or “Non-ASC 310-30” loans). The Company has elected to account for loans acquired with deteriorated credit quality since origination under ASC 310-30 (“ASC 310-30” loans or pools) due to the following: • There is evidence of credit quality deterioration since origination resulting in a “Day 1” discount attributable, at least in part, to credit quality; • The loans were acquired in a business combination or asset purchase; and • The loans are not to be subsequently accounted for at fair value. The Company has elected this policy for loans acquired through business combinations exhibiting credit deterioration since origination, except those loan types which have been scoped out of ASC 310-30. Substantially all loans acquired through the FDIC-assisted acquisitions had a fair value discount at acquisition date due at least in part to deterioration in credit quality since origination. However, there was a separate grouping of loans individually identified with substantial credit impairment that would be explicitly scoped into ASC 310-30 from those that were classified by analogy. The Company determined that a loan would be explicitly scoped into ASC 310-30 if there was evidence of credit deterioration at Day 1 and that it was probable that the Company would be unable to collect all contractual cash flows receivable. The loans that were classified by analogy were determined to have evidence of credit deterioration at Day 1 and that it was possible, not probable, that the Company would be unable to collect all contractual cash flows receivable. For each acquisition, ASC 310-30 loans are aggregated into pools based on common risk characteristics, which includes similar credit risk of the loans based on whether loans were analogized or were explicitly scoped into ASC 310-30, internal risk ratings for commercial real estate, land and development and commercial loans; and performing status for consumer and single family residential loans. Pools of loans are further aggregated by collateral type (e.g. commercial real estate, single family residential, etc.). The Company did not elect to aggregate loans into pools that were acquired from separate acquisitions completed in the same fiscal quarter. Acquired loans are recorded at their fair value at the acquisition date. Fair value for acquired loans is based on a discounted cash flow methodology that considers factors including the type of loan and related collateral type, delinquency and credit classification status, fixed or variable interest rate, term of loan, whether or not the loan was amortizing, and current discount rates. Additional assumptions used include default rates, loss severity, loss curves and prepayment speeds. Discounts due to credit quality are included in the determination of fair value; therefore an allowance for loan losses is not recorded at the acquisition date. The discount rates used for the cash flow methodology are based on market rates for new originations of comparable loans at the time of acquisition and include adjustments for liquidity concerns. The fair value is determined from the discounted cash flows for each individual loan, and for ASC 310-30 loans are then aggregated at the unit of account, or pool level. For acquired loans with deteriorated credit quality, the Company makes an estimate of the total cash flows it expects to collect from the loans in each pool, which includes undiscounted expected principal and interest as well as cash received through other forms of satisfaction (e.g. foreclosure). The excess of contractual amounts over the total cash flows expected to be collected from the loans is referred to as non-accretable difference, which is not accreted into income. The excess of the expected undiscounted cash flows over the carrying value of the loans is referred to as accretable discount. Accretable discount is recognized as interest income on a level-yield basis over the expected term of the loans in each pool. The Company continues to estimate cash flows expected to be collected over the expected term of the ASC 310-30 loans on a quarterly basis. Subsequent increases in total cash flows expected to be collected are recognized as an adjustment to the accretable discount with the amount of periodic accretion adjusted over the remaining expected term of the loans. Subsequent decreases in cash flows expected to be collected over the expected term of the loans are recognized as impairment in the current period through a provision for loan losses. Each pool is accounted for as a single asset with a single composite interest rate and an aggregate expectation of cash flows. Resolutions of loans may include sales to third parties, receipt of payments in settlement with the borrower, or foreclosure of the collateral. Upon these resolutions, the Company’s policy is to remove an individual ASC 310-30 loan from a pool based on comparing the amount received from its resolution with its contractual amount. Any difference between these amounts is absorbed by the nonaccretable difference. This removal method assumes that the amount received from these resolutions approximates the pool performance expectations of cash flows. The accretable yield percentage is unaffected by the resolution. Any changes in the effective yield for the remaining loans in the pool are addressed by the quarterly cash flow evaluation process for each pool. For loans that are resolved by payment in full, there is no release of the nonaccretable difference for the pool because there is no difference between the amount received at resolution and the contractual amount of the loan. Payments received in excess of expected cash flows may result in an ASC 310-30 pool becoming fully amortized and its carrying value reduced to zero even though outstanding contractual balances remain related to loans in the pool. Once the carrying value of an ASC 310-30 pool is reduced to zero, any future proceeds from the borrower or from the sale of loans are recognized as interest income upon receipt. There were six ASC 310-30 pools whose carrying value had been reduced to zero as of December 31, 2017 . These pools had an aggregate Unpaid Principal Balance (“UPB” or “UPBs”) of $399 thousand as of December 31, 2017 . For the year ended December 31, 2017 , the Company sold approximately $11.7 million of loans accounted for under ASC 310-30. These sales resulted in proceeds that exceeded the carrying value of the accounting pool in which the loans resided of $3.3 million which was recognized as interest income. There were six ASC 310-30 pools whose carrying value had been reduced to zero as of December 31, 2016 . These pools had an aggregate UPB of $456 thousand as of December 31, 2016 . For the year ended December 31, 2016 , the Company sold approximately $75.3 million of loans accounted for under ASC 310-30. These sales resulted in proceeds that exceeded the carrying value of the accounting pool in which the loans resided of $27.2 million which was recognized as interest income. Non-ASC 310-30 loans are recorded at their estimated fair value as of the acquisition date and subsequently accounted for under ASC Topic 310-20, Receivables—Nonrefundable Fees and Other Costs (“ASC 310-20”). The fair value discount is accreted using methods which approximate the level-yield method over the remaining term of the loans and is recognized as a component of interest income.
Loans Held for Sale	Loans Held for Sale Certain residential fixed rate and adjustable rate mortgage loans originated by the Company with the intent to sell in the secondary market are carried at the lower of cost or fair value, as determined by outstanding commitments from investors or prevailing market prices. These loans are generally sold on a non-recourse basis with servicing released. Gains and losses on the sale of loans recognized in earnings are measured based on the difference between proceeds received and the carrying amount of the loans, inclusive of deferred origination fees and costs, if any.
Nonaccrual Loans	Nonaccrual Loans For New and Non-ASC 310-30 loans, the Company classifies loans as past due when the payment of principal or interest is greater than 30 days delinquent based on the contractual next payment due date. The Company’s policies related to when loans are placed on nonaccrual status conform to guidelines prescribed by regulatory authorities. Loans are placed on nonaccrual status when it is probable that principal or interest is not fully collectible, or generally when principal or interest becomes 90 days past due, whichever occurs first. Loans secured by 1-4 single family residential properties may remain in accruing status until they are 180 days past due if management determines that it does not have concern over the collectability of principal and interest because the loan is adequately collateralized and in the process of collection. When loans are placed on nonaccrual status, interest receivable is reversed against interest income in the current period and amortization of any discount ceases. Interest payments received thereafter are applied as a reduction to the remaining principal balance unless management believes that the ultimate collection of the principal is likely, in which case payments are recognized in earnings on a cash basis. Loans are removed from nonaccrual status when they become current as to both principal and interest and the collectability of principal and interest is no longer doubtful. Generally, a nonaccrual loan that is restructured remains on nonaccrual for a period of six months to demonstrate the borrower can meet the restructured terms. However, performance prior to the restructuring, or significant events that coincide with the restructuring, are considered in assessing whether the borrower can meet the new terms and may result in the loan being returned to accrual status after a shorter performance period. If the borrower’s ability to meet the revised payment schedule is not reasonably assured, the loan remains classified as a nonaccrual loan. Contractually delinquent ASC 310-30 loans are not classified as nonaccrual as long as the discount continues to be accreted on the corresponding ASC 310-30 pool.
Troubled Debt Restructurings	Troubled Debt Restructurings In certain situations, due to economic or legal reasons related to a borrower’s financial difficulties, the Company may grant a concession to the borrower for other than an insignificant period of time that it would not otherwise consider. At that time, except for ASC 310-30 loans, which are accounted for as pools, the related loan is classified as a troubled debt restructuring (“TDR”) and considered impaired. Modified ASC 310-30 loans accounted for in pools are not accounted for as TDRs, are not separated from the pools and are not classified as impaired loans. The concessions granted may include rate reductions, principal forgiveness, payment forbearance, extensions of maturity at rates of interest below those commensurate with the risk profile of the borrower, and other actions intended to minimize economic loss. A troubled debt restructured loan is generally placed on nonaccrual status at the time of the modification unless the borrower has no history of missed payments for six months prior to the restructuring. If the borrower performs pursuant to the modified loan terms for at least six months and the remaining loan balance is considered collectible, the loan is returned to accrual status.
Impaired Loans	Impaired Loans An ASC 310-30 pool is considered to be impaired when it is probable that the Company will be unable to collect all the cash flows expected at acquisition, plus additional cash flows expected to be collected arising from changes in estimates after acquisition. All ASC 310-30 pools are evaluated individually for impairment based their expected total cash flows. The discount continues to be accreted on ASC 310-30 pools as long as there are expected future cash flows in excess of the current carrying amount of the pool. Non-ASC 310-30 and New loans are considered impaired when, based on current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due, according to the contractual terms of the loan agreements. All Non-ASC 310-30 and New loans of $250,000 or greater with an internal risk rating of substandard or below and on nonaccrual, as well as loans classified as TDRs are reviewed individually for impairment on a quarterly basis.
Allowance for Loan Losses	Allowance for Loan Losses ("ALL") The Company’s ALL is established for both performing and nonperforming loans. The Company’s ALL is the amount considered adequate to absorb probable losses within the portfolio based on management’s evaluation of the size and current risk characteristics of the loan portfolio. Such evaluation considers numerous factors including, but not limited to, internal risk ratings, loss forecasts, collateral values, geographic location, borrower FICO scores, delinquency rates, nonperforming and restructured loans, origination channels, product mix, underwriting practices, industry conditions, economic trends and net charge-off trends. The ALL relates to New loans, estimated additional losses arising on Non-ASC 310-30 loans subsequent to the acquisitions and additional impairment recognized as a result of decreases in expected cash flows on ASC 310-30 pools due to further credit deterioration or other factors since the acquisitions. The ALL consists of both specific and general components. For ASC 310-30 pools, a specific valuation allowance is established when it is probable that the Company will be unable to collect all of the cash flows expected at acquisition, plus the additional cash flows expected to be collected arising from changes in estimates after acquisition. Expected cash flows are estimated on an individual loan basis and then aggregated at the ASC 310-30 pool level. The analysis of expected pool cash flows incorporates updated pool level expected prepayment rate, default rate, delinquency level and loss severity given default assumptions. These analyses incorporate information about loan performance, collateral values, the financial condition of the borrower, internal risk ratings, the Company’s own and industry historical delinquency and default severity data. The carrying value for ASC 310-30 pools is reduced by the amount of the calculated impairment, which is also the basis in which future accretion income is calculated. A charge-off is taken for an individual ASC 310-30 loan when it is deemed probable that the loan will be resolved for an amount less than its carrying value. The charge-off is taken to the specific allowance or mark as applicable. Alternatively, an improvement in the expected cash flows related to ASC 310-30 pools results in a reduction or recoupment of any previously established specific allowance with a corresponding credit to the provision for loan losses. Any recoupment recorded is limited to the amount of the remaining specific allowance for that pool, with any excess of expected cash flow resulting in a reclassification from non-accretable to accretable yield and an increase in the prospective yield of the pool. The New and Non-ASC 310-30 loan portfolios have limited delinquency and credit loss history and have not yet exhibited an observable loss trend. The credit quality of loans in these loan portfolios are impacted by delinquency status and debt service coverage generated by the borrowers’ businesses and fluctuations in the value of real estate collateral. Management considers delinquency status to be the most meaningful indicator of the credit quality of one-to-four single family residential, home equity loans and lines of credit and other consumer loans. Delinquency statistics are updated at least monthly. Internal risk ratings are considered the most meaningful indicator of credit quality for Non-ASC 310-30 and new commercial, construction, land and development, and commercial real estate loans. Internal risk ratings are a key factor in identifying loans that are individually evaluated for impairment and impact management’s estimates of loss factors used in determining the amount of the ALL. Internal risk ratings are updated on a continuous basis. Relationships with balances in excess of $250,000 are re-evaluated at least annually and more frequently if circumstances indicate that a change in risk rating may be warranted. New and Non-ASC 310-30 loans of $250,000 or greater with an internal risk rating of substandard or below and on nonaccrual, as well as loans classified as TDR are reviewed individually for impairment on a quarterly basis. The specific allowance established for these loans is based on a thorough analysis of the most probable source of repayment, including the present value of the loan’s expected future cash flows, the loan’s estimated market value or the estimated fair value of the underlying collateral less costs of disposition. General allowances are established for new and Non-ASC 310-30 loans that are not evaluated individually for impairment, which are evaluated by loan category based on common risk characteristics. In this process, general loan loss factors are established based on the following: industry historical losses segmented by portfolio and asset categories; trends in delinquencies and nonaccruals by loan portfolio segment and asset categories within those segments; portfolio segment and asset category production trends, including average risk ratings and loan-to value (“LTV”) ratios; current industry conditions, including real estate market trends; general economic conditions; credit concentrations by portfolio and asset categories; and portfolio quality, which encompasses an assessment of the quality and relevance of borrowers’ financial information and collateral valuations and average risk rating and migration trends within portfolios and asset categories. Other adjustments for qualitative factors may be made to the allowance after an assessment of internal and external influences on credit quality and loss severity that are not fully reflected in the historical loss or risk rating data. For these measurements, the Company uses assumptions and methodologies that are relevant to estimating the level of impairment and probable losses in the loan portfolio. To the extent that the data supporting such assumptions has limitations, management’s judgment and experience play a key role in recording the allowance estimates. Qualitative adjustments are considered for: portfolio credit quality trends, including levels of delinquency, charge-offs, nonaccrual, restructuring and other factors; policy and credit standards, including quality and experience of lending and credit management; and general economic factors, including national, regional and local conditions and trends. Additions to the ALL are made by provisions charged to earnings. The allowance is decreased by charge-offs of balances no longer deemed collectible. Charge-offs on new and Non-ASC 310-30 loans are recognized as follows: commercial loans are written-off when management determines them to be uncollectible; for unsecured consumer loans at 90 days past due; and for residential real estate loans and secured consumer loans when they become 120 to 180 days past due, depending on the collateral type. The Company reports recoveries on a cash basis at the time received. Recoveries on ASC 310-30 loans that were charged-off and Non-ASC 310-30 loans that were charged-off prior to the Acquisitions are recognized in earnings as income from resolution of acquired assets and do not affect the allowance for loan losses. All other recoveries are credited to the ALL.
Loss Share Indemnification Asset and Clawback Liability	Loss Share Indemnification Asset and Clawback Liability On March 4, 2015, the Bank entered into an agreement with the FDIC to terminate all loss sharing agreements which were entered into in 2010 and 2011 in conjunction with the Bank’s acquisition of substantially all of the assets (“Covered Assets”) and assumption of substantially all of the liabilities of six failed banks in FDIC-assisted acquisitions. Under the early termination, all rights and obligations of the Bank and the FDIC under the loss share agreements, including the clawback provisions, have been eliminated. The amounts previously covered by the loss sharing agreements were the pre-acquisition book value of the underlying assets, the contractual balance of unfunded commitments that were acquired, and certain future net direct costs applicable to the Covered Assets. As required by the respective loss sharing agreements, the Company submitted a loss share certificate to the FDIC on a quarterly basis requesting reimbursement for losses on covered assets and covered expenses. Covered expenses were recorded in non-interest expense when incurred with an offsetting increase to the loss share indemnification asset and non-interest income for the amount expected to be reimbursed by the FDIC. Certain covered expenses were claimed upon resolution of the Covered Asset, resulting in the expense and the related reimbursements from the FDIC occurring in different periods. The Company reviewed and updated the cash flows expected to be collected on Covered Assets and the FDIC loss share indemnification asset on a quarterly basis as loss and recovery estimates related to Covered Assets change. Decreases in the amount of cash flows expected to be collected on Covered Loans after acquisition resulted in a provision for loan loss, an increase in the ALL, and a proportional increase to the FDIC loss share indemnification asset and income for the estimated amount to be reimbursed. Increases in the amount of cash flows expected to be collected on Covered Loans after acquisition resulted in the reversal of any previously-recorded provision for loan losses and related ALL and a decrease to the FDIC loss share indemnification asset, or prospective adjustment to the accretable discount if no provision for loan losses had been previously recorded. If no provision for loan losses had been previously recorded, improvements in the expected cash flows from the Covered Loans, which was reflected as an adjustment to yield and accreted into income over the remaining expected term of the loans, decreases the expected cash flows to be collected from the loss sharing agreement, with such decreases reducing the yield to be accreted on a prospective basis if the total expected cash flows from the loss sharing agreement exceeded its carrying amount; and, if the carrying amount of the FDIC loss share indemnification asset exceeded the total expected cash flows, the excess was amortized as a reduction of income over the shorter of (1) the remaining expected term of the respective loans or (2) the remaining term of the loss sharing agreement. As a result, the value of the FDIC loss share indemnification asset fluctuated over time based upon the performance of the Covered Assets and as the Company received payments from the FDIC under the loss sharing agreements. The loss sharing agreements between the Company and the FDIC for certain of the Acquisitions included clawback provisions that obligated the Company to pay the FDIC a certain amount in the event that losses incurred by the Company did not reach a specified threshold upon expiration of the loss sharing agreement. The fair value of the clawback liability was initially estimated using the same discounted cash flow model used to determine the loss share indemnification asset, using a discount rate that took into account the Company’s credit risk. The clawback liability was re-measured quarterly based on the terms of the applicable loss sharing agreement, changes in projected losses on Covered Assets and the cumulative servicing amount, if applicable. The clawback liability was included in other liabilities and the amortization and loss on re-measurement was included in loss share indemnification loss within noninterest income in the accompanying Consolidated Statements of Income.
Premises and Equipment	Premises and Equipment Premises and equipment are stated at cost less accumulated depreciation or amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the related assets, except for land which is stated at cost. The useful lives of premises and equipment are: 39 years for bank premises; 3 to 5 years for computer equipment and software; and 5 years for furniture and equipment. Leasehold improvements are amortized on a straight-line basis over the lesser of the lease terms, including certain renewals that were deemed probable at lease inception, or the estimated useful lives of the improvements. Purchased software and external direct costs of computer software developed for internal use are capitalized provided certain criteria are met and amortized over the useful lives of the software. Rent expense and rental income on operating leases are recorded using the straight-line method over the appropriate lease terms.
Other Real Estate Owned (OREO)	Other Real Estate Owned ("OREO") Real estate properties acquired through, or in lieu of, foreclosure or in connection with the Acquisitions, are held for sale and are initially recorded at their fair value less disposition costs. When such assets are acquired, any shortfall between the loan carrying value and the estimated fair value of the underlying collateral less disposition costs is recorded as an adjustment to the allowance for loan losses while any excess is recognized in income. The Company periodically performs a valuation of the property held; any excess of carrying value over fair value less disposition costs is charged to earnings as impairment. Routine maintenance and real estate taxes are expensed as incurred.
Bank-Owned Life Insurance (BOLI)	BOLI") The Bank owns life insurance policies on certain directors and current and former employees. These policies are 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, if applicable. Increases in the cash surrender value of these policies are included in noninterest income in the Consolidated Statements of Income. The Company’s BOLI policies are invested in general account and hybrid account products that have been underwritten by highly-rated third party insurance carriers.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill represents the excess of consideration transferred in business combinations over the fair value of net tangible and identifiable intangible assets acquired. Goodwill is not amortized, but is tested for impairment annually or more frequently if events or circumstances indicate that impairment may have occurred. The Company performs its annual goodwill impairment test in the fourth fiscal quarter. The Company has a single reporting unit. The impairment test compares the estimated fair value of the reporting unit to its carrying amount. If the fair value of the reporting unit exceeds its carrying amount, no impairment is indicated. If the fair value of the reporting unit is less than its carrying amount, impairment of goodwill is measured as the excess of the carrying amount of goodwill over its implied fair value. The Company uses the fair value of the Company’s publicly traded stock to estimate the fair value of the reporting unit. The estimated fair value of the reporting unit at the last impairment testing date exceeded its carrying amount; therefore, no impairment of goodwill was indicated. Core deposit intangible (“CDI”) is a measure of the value of checking and savings deposit relationships acquired in a business combination. The fair value of the CDI stemming from any given business combination is based on the present value of the expected cost savings attributable to the core deposit funding relative to an alternative source of funding. CDI is amortized over the estimated useful lives of the existing deposit relationships acquired, but does not exceed 10 years. The Company evaluates such identifiable intangibles for impairment when events and circumstances indicate that its carrying amount may not be recoverable. If an impairment loss is determined to exist, the loss is reflected as an impairment charge in the Consolidated Statements of Income for the period in which such impairment is identified. No impairment charges were required to be recorded for the years ended December 31, 2017 , 2016 or 2015 .
Income Taxes	Income Taxes Income tax expense (benefit) is determined using the asset and liability method and consists of income taxes that are currently payable and deferred income taxes. Deferred income tax expense is determined by recognizing deferred tax assets and liabilities for future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates that are expected to apply to taxable income in years in which those temporary differences are expected to be recovered or settled. Changes in tax rates on deferred tax assets and liabilities are recognized in income in the period that includes the enactment date. A valuation allowance is established for deferred tax assets when management determines that it is more likely than not that some portion or all of a deferred tax asset will not be realized. In making such determinations, the Company considers all available positive and negative evidence that may impact the realization of deferred tax assets. These considerations include the amount of taxable income generated in statutory carryback periods, future reversals of existing taxable temporary differences, projected future taxable income and available tax planning strategies. The Company files a consolidated federal income tax return including the results of its wholly owned subsidiary, the Bank. The Company estimates income taxes payable based on the amount it expects to owe the various tax authorities (i.e., federal and state). Income taxes represent the net estimated amount due to, or to be received from, such tax authorities. In estimating income taxes, management assesses the relative merits and risks of the appropriate tax treatment of transactions, taking into account statutory, judicial, and regulatory guidance in the context of the Company’s tax position. Although the Company uses the best available information to record income taxes, underlying estimates and assumptions can change over time as a result of unanticipated events or circumstances such as changes in tax laws and judicial guidance influencing its overall tax position. An uncertain tax position is recognized only if it is more-likely-than-not to be sustained upon examination, including resolution of any related appeals or litigation process, based on the technical merits of the position. The amount of tax benefit recognized in the financial statements is the largest amount of benefit that is more than fifty percent likely to be sustained upon ultimate settlement of the uncertain tax position. If the initial assessment fails to result in recognition of a tax benefit, the Company subsequently recognizes a tax benefit if there are changes in tax law or case law that raise the likelihood of prevailing on the technical merits of the position to more-likely-than-not, the statute of limitations expires, or there is a completion of an examination resulting in a settlement of that tax year or position with the appropriate agency. The Company recognizes interest related to unrecognized tax benefits in income tax expense (benefit) and penalties, if any, in other operating expenses.
Derivatives	Derivatives The Company accounts for derivative instruments in accordance with ASC Topic 815, “Derivatives and Hedging.” All derivatives are evaluated at inception as to whether or not they are hedging or non-hedging activities, and appropriate documentation is maintained to support the final determination. The Company recognizes all derivatives as either assets or liabilities on the Consolidated Balance Sheets and measures those instruments at fair value. Certain derivative transactions with a particular counterparty, another financial institution, are subject to an enforceable master netting arrangement. The gross liabilities and gross assets to this counterparty are reported on a net basis. Management periodically reviews contracts from various functional areas of the Company to identify potential derivatives embedded within selected contracts. As of December 31, 2017, the Company had interest rate derivative contracts that are not designated as hedging instruments. See Note 8 “Derivatives” for a description of these instruments.
Off-Balance Sheet Arrangements	Off-Balance Sheet Arrangements The Company enters into contractual loan commitments to extend credit, normally with fixed expiration dates or termination clauses, at specified rates and for specific purposes. Since a portion of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. Substantially all of the commitments to extend credit are contingent upon customers maintaining specific credit standards until the time of loan funding. The Company decreases its exposure to loss under these commitments by subjecting them to credit approval and monitoring procedures. Standby letters of credit are written conditional commitments issued by the Company to guarantee the performance of a customer to a third party. In the event the customer does not perform in accordance with the terms of the agreement with the third party, the Company would be required to fund the commitment. The maximum potential amount of future payments the Company could be required to make is represented by the contractual amount of the commitment. If the commitment is funded, the Company would be entitled to seek recovery from the customer. The Company’s policies generally require that standby letter of credit arrangements contain security and debt covenants similar to those contained in loan agreements. The Company assesses the credit risk associated with certain commitments to extend credit and establish a liability for probable credit losses. The Company’s exposure to credit loss is represented by the contractual amount of these commitments. The Company records a reserve in the amount considered adequate to absorb estimated losses. Since the Company has limited credit loss history, management performs an analysis of reserve rates for a peer group comprised of banks of similar size, loan portfolio composition and geographic footprint to which FCB, its board of directors, and analysts benchmark the Banks' performance. This analysis involves calculating an average reserve rate for unfunded commitments using a rolling twelve quarter basis of the most recent data available. Based on this peer group analysis, FCB records a reserve for unfunded commitments calculated using a rate in line with peer banks.
Stock-based Compensation	Stock-based Compensation The Company sponsors an incentive stock option plan established in 2009 (the “2009 Option Plan”) under which options may be granted periodically to key employees and directors of the Company or its affiliates at a specific exercise price to acquire shares of the Company’s Class A common stock. Compensation cost is measured based on the estimated fair value of the award at the grant date and is recognized in earnings on a straight-line basis over the requisite service period. The fair value of stock options is estimated at the date of grant using the Black-Scholes option pricing model. This model requires assumptions as to the expected stock volatility, dividends, terms and risk-free rates. The expected volatility is based on the volatility of comparable peer banks. The expected term represents the period of time that options are expected to be outstanding from the grant date. The risk-free interest rate is based on the US Treasury yield curve in effect at the time of grant for the appropriate life of each option. The expected dividend yield was determined by management based on the expected dividends to be declared over the expected term of the options. In the fourth quarter of 2013, the Company established the 2013 Stock Incentive Plan (the “2013 Incentive Plan”) covering its executive management, directors, individual consultants and employees to receive stock awards for the Company’s common stock. The 2013 Incentive Plan provided that the awards were not exercisable until certain performance conditions were met, which included the completion of an IPO raising at least $100 million (a “Qualified IPO”) or a “Special Transaction”, generally defined as the consummation of a transaction representing a change of control of the Company. On August 6, 2014, the Company completed the initial public offering of 7,520,000 shares of Class A common stock for $22.00 per share. This public offering constituted a “Qualified IPO” with respect to the Company’s Option awards and 2013 Incentive Plan. In 2016, the Company approved the FCB Financial Holdings, Inc. 2016 Stock Incentive Plan (the “2016 Incentive Plan”) covering its executive management, directors, individual consultants and employees. The 2016 Incentive Plan provides that awards may be granted under the plan with respect to an aggregate of 2,000,000 shares of Class A Common Stock of the Company. Shares issued pursuant to the Plan may be authorized but unissued Common Stock, authorized and issued Common Stock held in the Company’s treasury or Common Stock acquired by the Company for the purposes of the Plan. See Note 14 “Stock-based Compensation and Other Benefit Plans” for further information regarding the 2009 Option Plan and the 2013 and 2016 Incentive Plans.
Earnings per Share	Earnings per Share Basic earnings per common share is calculated by dividing net income available to common stockholders by the weighted average number of common shares outstanding during the period. Diluted earnings per common share reflect the effect of common stock equivalents, including stock options and unvested shares, calculated using the treasury stock method. Common stock equivalents are excluded from the computation of diluted earnings per common share in periods in which the effect is anti-dilutive.
Segment Reporting	Segment Reporting The Company operates in one reportable segment of business, Community Banking, which includes the Bank, the Company’s sole banking subsidiary. Through the Bank, the Company provides a broad range of retail and commercial banking services. Management makes operating decisions and assesses performance based on an ongoing review of these banking operations, which constitute the Company’s only operating segment.
Recent Adopted and Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements In March 2016, the FASB issued ASU No. 2016-09, “Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting” which simplifies several aspects of the accounting for employee share-based payment transactions including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. This ASU eliminates equity treatment for tax benefits or deficiencies that result from differences between the compensation cost recognized for GAAP purposes and the related tax deduction at settlement or expiration with such changes recognized in income tax expense and excludes excess tax benefits and tax deficiencies from the calculation of assumed proceeds for earnings per share purposes since such amounts are recognized in the income statement. In addition, this ASU simplifies the statements of cash flows by eliminating the bifurcation of excess tax benefits from operating activities to financing activities. The Company recognized approximately $22.0 million of tax benefit in the consolidated statement of income during the year ended December 31, 2017 as a result of the adoption of this guidance that previously would have been recorded in additional paid in capital. The requirement to recognize excess tax benefits and tax deficiencies in the income statement was applied prospectively. This ASU became effective for the first quarter ended March 31, 2017. In March 2016, the FASB issued ASU No. 2016-06, “Derivatives and Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments” which 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 the amendments in this ASU is required to assess the embedded call (put) options solely in accordance with the four-stop decision sequence. This ASU became effective for the first quarter ended March 31, 2017. The adoption of this guidance did not have a material impact on the consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-07, “Investments-Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting” which eliminate the requirement that when an investment qualifies for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investment, results of operations, and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods that the investment had been held. The amendments require that the equity method investor add the cost of acquiring the additional interest in the investee to the current basis of the investor’s previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. Therefore, upon qualifying for the equity method of accounting, no retroactive adjustment of the investment is required. The amendments in this ASU require that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in accumulated other comprehensive income at the date the investment becomes qualified for use of the equity method. This ASU became effective for the first quarter ended March 31, 2017. The adoption of this guidance did not have a material impact on the consolidated financial statements. In August 2014, the FASB issued ASU No. 2014-15, “Presentation of Financial Statements – Going Concern (Subtopic 205-40)”. This update requires management to evaluate whether there are conditions and events that raise substantial doubt about an entity’s ability to continue as a going concern. The guidance is intended to incorporate into GAAP a requirement that management perform a going concern evaluation similar to the auditor’s evaluation required by standards issued by the Public Company Accounting Oversight Board (“PCAOB”) and American Institute of Certified Public Accountants (“AICPA”). This ASU became effective for the first quarter ended March 31, 2017. The adoption of this guidance did not have a material impact on the consolidated financial statements. Recent Issued Accounting Pronouncements In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)”, which will supersede the revenue recognition requirements in Topic 605, Revenue Recognition, and most industry-specific revenue recognition guidance throughout the Accounting Standards Codification. Under ASU No. 2014-09, revenue should be recognized to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In applying the guidance, an entity should 1) identify the contract(s) with a customer, 2) identify the performance obligations in the contract, 3) determine the transaction price, 4) allocate the transaction price to the performance obligations in the contract, and 5) recognize revenue when the entity satisfies a performance obligation. For public entities, the amendments in this update are effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. In August 2015, the FASB issued ASU No. 2015-14 delaying the effective date of ASU No. 2014-09. Public business entities, certain not-for-profit entities, and certain employee benefit plans should apply the guidance in ASU No. 2014-09 to annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. This guidance should be applied to all contracts with customers except those that are within the scope of other standards. Since the Company's revenue is comprised primarily of net interest income from financial instruments that are within the scope of other standards, including loans and securities, the new guidance is not expected to have material impact upon adoption. The Company conducted an analysis to determine the impact this guidance would have on the components of noninterest income and did not identify any material changes on to the method of revenue recognition. Accordingly, the Company does not expect the adoption of this guidance to have a material impact on the Company's consolidated financial position, results of operations or cash flows. The Company has elected to adopt the new guidance under the modified retrospective approach. In January 2016, the FASB issued ASU No. 2016-01, “Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities” which: • Requires equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income. • Simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment. When a qualitative assessment indicates that impairment exists, an entity is required to measure the investment at fair value. • Eliminates the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet. • Requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes. • Requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. • Requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset (that is, securities or loans and receivables) on the balance sheet or the accompanying notes to the financial statements. • Clarifies that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity’s other deferred tax assets. For public business entities, the amendments in this ASU are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early application by public business entities to financial statements of fiscal years or interim periods that have not yet been issued or, by all other entities, that have not yet been made available for issuance of the following amendments in this ASU are permitted as of the beginning of the fiscal year of adoption: 1. An entity should 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 if the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. 2. Entities that are not public business entities are not required to apply the fair value of financial instruments disclosure guidance in the General Subsection of Section 825-10-50. Except for the early application guidance discussed above, early adoption of the amendments in this ASU is not permitted. An entity should apply the amendments by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. The amendments related to equity securities without readily determinable fair values (including disclosure requirements) should be applied prospectively to equity investments that exist as of the date of adoption of the ASU. As of December 31, 2017, the Company has equity securities in a net unrealized gain position of $1.6 million that will be reclassified from other comprehensive income to retained earnings upon adoption. In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842)” which created Topic 842, Leases, and supersedes the leases requirements in Topic 840, Leases. Topic 842 specifies the accounting for leases. The core principal of Topic 842 is that a lessee should recognize the assets and liabilities that arise from leases. A lessee should recognize in the statement of financial position a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. For leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and liabilities. For public entities, the amendments in this ASU are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early application of the amendments in this ASU is permitted. The Company does not believe the adoption of this guidance will have a material impact on its consolidated financial position, results of operations or cash flows. In May 2016, the FASB issued ASU No. 2016-10, “Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing.” The amendments in this ASU do not change the core principle of the guidance in Topic 606. Rather, the amendments in this ASU clarify the following two aspects of Topic 606: identifying performance obligations and the licensing implementation guidance, while retaining the related principles for those areas. The amendments in this ASU affect the guidance in ASU 2014-09, “Revenue from Contracts with Customers (Topic 606)”, which is not yet effective. The effective date and transition requirements for the amendments in this ASU are the same as the effective date and transition requirements in Topic 606 (and any other Topic amended by ASU 2014-09). ASU 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date”, deferred the effective date of ASU 2014-09 by one year. Public business entities, certain not-for-profit entities, and certain employee benefit plans should apply the guidance in ASU 2014-09 to annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Management does not expect the adoption of this guidance to have a material impact on the Company's consolidated financial position, results of operations or cash flows. In May 2016, the FASB issued ASU No. 2016-12, “Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients.” The amendments in this ASU do not change the core principle of the guidance in Topic 606. Rather, the amendments in this ASU clarify the guidance on assessing collectability, presentation of sales taxes, noncash consideration, and completed contracts and contract modifications at transition. The amendments in this ASU affect the guidance in ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), which is not yet effective. The effective date and transition requirements for the amendments in this ASU are the same as the effective date and transition requirements in Topic 606 (and any other Topic amended by ASU 2014-09). ASU 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date”, deferred the effective date of ASU 2014-09 by one year. Public business entities, certain not-for-profit entities, and certain employee benefit plans should apply the guidance in ASU 2014-09 to annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Management does not expect the adoption of this guidance to have a material impact on the Company's consolidated financial position, results of operations or cash flows. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments - Credit losses (Topic 326): Measurement of credit losses on financial instruments.” Topic 326 amends guidance on reporting credit losses for assets held at amortized cost basis and available for sale debt securities. For assets held at amortized cost basis, Topic 326 eliminates the probable initial recognition threshold in current GAAP and, instead, requires an entity to reflect its current estimate of all expected credit losses. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial assets to present the net amount expected to be collected. For available for sale debt securities, credit losses should be measured in a manner similar to current GAAP, however Topic 326 will require that credit losses be presented as an allowance rather than as a write-down. This ASU affects entities holding financial assets and net investment in leases that are not accounted for at fair value through net income. The amendments affect loans, debt securities, trade receivables, net investments in leases, off balance sheet credit exposures, reinsurance receivables, and any other financial assets not excluded from the scope that have the contractual right to receive cash. For public business entities that are SEC filers, the amendments in this ASU are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. For all other public business entities, the amendments in this ASU are effective for fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. All entities may adopt the amendments in this ASU earlier as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. An entity will apply the amendments in this ASU through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective (that is, a modified-retrospective approach). A prospective transition approach is required for debt securities for which an other-than-temporary impairment had been recognized before the effective date. The effect of a prospective transition approach is to maintain the same amortized cost basis before and after the effective date of this ASU. Amounts previously recognized in accumulated other comprehensive income as of the date of adoption that relate to improvements in cash flows expected to be collected should continue to be accreted into income over the remaining life of the asset. Recoveries of amounts previously written off relating to improvements in cash flows after the date of adoption should be recorded in earnings when received. The Company is currently evaluating this guidance to determine the impact on its consolidated financial position, results of operations or cash flows. In August 2016, the FASB issued ASU No. 2016-15, "Statement of cash flows (Topic 230): Classification of certain cash receipts and cash payments." The objective of this guidance is to reduce the diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows under Topic 230, Statement of Cash Flows, and other Topics. This ASU addresses the following eight specific cash flow issues: Debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies (COLIs) (including bank-owned life insurance policies (BOLIs)); distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. The amendments in this Update are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The amendments in this ASU should be applied using a retrospective transition method to each period presented. The Company does not expect the adoption of this guidance to have a material impact on the Company's consolidated cash flow statement. In October 2016, the FASB issued ASU No. 2016-16, "Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory." The objective of issuing this ASU is to improve the accounting for the income tax consequences of intra-entity transfers of assets other than inventory. Current GAAP prohibits the recognition of current and deferred income taxes for an intra-entity asset transfer until the asset has been sold to an outside party. This prohibition on recognition is an exception to the principle of comprehensive recognition of current and deferred income taxes in GAAP. As such, the Board decided that an entity should recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. Consequently, the amendments in this guidance eliminate the exception for an intra-entity transfer of an asset other than inventory. For public business entities, the amendments in this guidance are effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within those annual reporting periods. Early adoption is permitted for all entities as of the beginning of an annual reporting period for which financial statements (interim or annual) have not been issued or made available for issuance. That is, earlier adoption should be in the first interim period if an entity issues interim financial statements. The Company does not expect the adoption of this guidance to have a material impact on the Company's consolidated financial position, results of operations or cash flows. In November 2016, the FASB issued ASU No. 2016-18, "Statement of Cash Flows (Topic 230): Restricted Cash (a consensus of the FASB Emerging Issues Task Force)." The amendments in this ASU require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The amendments in this ASU do not provide a definition of restricted cash or restricted cash equivalents. The amendments in this ASU are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. The amendments in this ASU should be applied using a retrospective transition method to each period presented. The Company does not expect the adoption of this guidance to have a material impact on the Company's consolidated cash flow statement. In January 2017, the FASB issued ASU No. 2017-04, "Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment." The amendments in this ASU modify the concept of impairment from the condition that exists when the carrying amount of goodwill exceeds its implied fair value to the condition that exists when the carrying amount of a reporting unit exceeds its fair value. An entity no longer will determine goodwill impairment by calculating the implied fair value of goodwill by assigning the fair value of a reporting unit to all of its assets and liabilities as if that reporting unit had been acquired in a business combination. The amendments in this ASU are effective for public business entities for fiscal years beginning after December 15, 2019 including any interim periods within that reporting period where goodwill impairment tests are performed. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company is currently evaluating this guidance to determine the impact on its consolidated financial position, results of operations or cash flows. In February 2017, the FASB issued ASU No. 2017-05, "Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets." The FASB is issuing this ASU to clarify the scope of Subtopic 610-20, Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets, and to add guidance for partial sales of nonfinancial assets. The amendments in this ASU will require all entities to account for the derecognition of a business or nonprofit activity in accordance with Topic 810. The amendments also eliminate several accounting differences between transactions involving assets and transactions involving businesses. The amendments in this ASU are effective for public business entities for fiscal years beginning after December 15, 2017. Public entities may apply the guidance earlier but only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. The Company does not expect the adoption of this guidance to have a material impact on the Company's consolidated financial position, results of operations or cash flows. In March 2017, the FASB issued ASU No. 2017-08, "Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities." This ASU shortens the amortization period for certain purchased callable debt securities held at a premium. The amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. For public business entities, the amendments in this ASU are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted, including adoption in an interim period. The Company is currently evaluating this guidance to determine the impact on its consolidated financial position, results of operations or cash flows. In May 2017, the FASB issued ASU No. 2017-09, "Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting." This ASU provides clarity when applying the guidance in Topic 718, specifically relating to a modification of a share-based payment award. Entities should treat changes as modifications unless the fair value, vesting conditions, and classification of the modified awards are unchanged from the conditions immediately before the change. The amendments in this ASU are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017. Early adoption is permitted, including adoption in an interim period. The Company does not expect the adoption of this guidance to have a material impact on the Company's consolidated financial position, results of operations or cash flows. In August 2017, the FASB issued ASU No. 2017-12, "Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities." This ASU improves the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements and makes certain targeted improvements to simplify the application of the hedge accounting guidance in current GAAP. The amendments in this update better align an entity's risk management activities and financial reporting for hedging relationships through changes to both the designation and measurement guidance for qualifying hedging relationships and presentation of hedge results. For public business entities, the amendments in this ASU are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted, including adoption in an interim period. The Company is currently evaluating this guidance to determine the impact on its consolidated financial position, results of operations or cash flows. In February 2018, the FASB issued ASU 2018-02, “Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” This ASU seeks to help entities reclassify certain stranded income tax effects in accumulated other comprehensive income resulting from the Tax Cuts and Jobs Act of 2017 (Tax Reform Act), enacted on December 22, 2017. ASU 2018-02 was issued in response to concerns regarding current guidance in GAAP that requires deferred tax liabilities and assets to be adjusted for the effect of a change in tax laws or rates with the effect included in income from continuing operations in the reporting period that includes the enactment date, even in situations in which the related income tax effects of items in accumulated other comprehensive income were originally recognized in other comprehensive income, rather than net income, and as a result the stranded tax effects would not reflect the appropriate tax rate. The amendments of ASU 2018-02 allow an entity to make a reclassification from accumulated other comprehensive income to retained earnings for the stranded tax effects, which is the difference between the historical corporate income tax rate of 35.0% and the newly enacted corporate income tax rate of 21.0%. The amendments in this ASU are effective for fiscal years, and interim periods within those years, beginning after December 31, 2018; however, public business entities are allowed to early adopt the amendments of ASU 2018-02 in any interim period for which the financial statements have not yet been issued. The amendments of ASU 2018-02 may be applied either at the beginning of the period (annual or interim) of adoption or retrospectively to each of the period(s) in which the effect of the change in the U.S. federal corporate tax rate in the Tax Reform Act is recognized. As a result of the re-measurement of the Company's deferred tax assets following the enactment of the Tax Reform Act, accumulated other comprehensive income included $1.9 million of stranded tax effects at December 31, 2017. The Company intends to early adopt the amendments of ASU 2018-02 during the first quarter of 2018 and plans to make an election to reclassify the stranded tax effects from accumulated other comprehensive income to retained earnings at the beginning of the period of adoption. Disclosures required by the amendments of ASU 2018-02 will be presented in the Quarterly Report on Form 10-Q for the period ending March 31, 2018. Adoption of ASU 2018-02 is not expected to have a material impact on the Company's consolidated financial statements.

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Summary of Amortized Cost, Gross Unrealized Gains and Losses and Approximate Fair Values of Securities Available for Sale	The amortized cost, gross unrealized gains and losses and approximate fair values of securities available for sale are as follows: Amortized Cost Unrealized Fair Value December 31, 2017 Gains Losses (Dollars in thousands) Available for sale: U.S. Government agencies and sponsored enterprises obligations $ 43,471 $ 38 $ 671 $ 42,838 U.S. Government agencies and sponsored enterprises mortgage-backed securities 600,310 1,716 6,789 595,237 State and municipal obligations 26,766 125 719 26,172 Asset-backed securities 608,340 2,306 100 610,546 Corporate bonds and other debt securities 738,994 18,222 1,313 755,903 Preferred stock and other equity securities 88,520 2,279 692 90,107 Total available for sale $ 2,106,401 $ 24,686 $ 10,284 $ 2,120,803 Amortized Cost Unrealized Fair Value December 31, 2016 Gains Losses (Dollars in thousands) Available for sale: U.S. Government agencies and sponsored enterprises obligations $ 16,512 $ 76 $ 274 $ 16,314 U.S. Government agencies and sponsored enterprises mortgage-backed securities 566,377 1,760 9,691 558,446 State and municipal obligations 28,109 148 578 27,679 Asset-backed securities 574,521 3,852 550 577,823 Corporate bonds and other debt securities 560,191 4,490 5,387 559,294 Preferred stock and other equity securities 137,228 814 1,164 136,878 Total available for sale $ 1,882,938 $ 11,140 $ 17,644 $ 1,876,434
Schedule of Amortized Cost and Estimated Fair Value of Securities Available for Sale	The amortized cost and estimated fair value of securities available for sale, by contractual maturity, are as follows: Amortized Cost Fair Value December 31, 2017 (Dollars in thousands) Available for sale: Due in one year or less $ 58,061 $ 58,605 Due after one year through five years 225,134 228,557 Due after five years through ten years 177,272 177,697 Due after ten years 305,293 317,216 U.S. Government agencies and sponsored enterprises obligations, mortgage-backed securities and tax-exempt mortgage securities, and asset-backed securities 1,252,121 1,248,621 Preferred stock and other equity securities 88,520 90,107 Total available for sale $ 2,106,401 $ 2,120,803
Summary of Estimated Fair Values and Gross Unrealized Losses on Investment Securities Available for Sale	The following tables present the estimated fair values and gross unrealized losses on investment securities available for sale, aggregated by investment category and length of time individual securities have been in a continuous unrealized loss position as of the periods presented: Less than 12 Months 12 Months or More Total December 31, 2017 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss (Dollars in thousands) Available for sale: U.S. Government agencies and sponsored enterprises obligations $ 31,518 $ 268 $ 7,157 $ 403 $ 38,675 $ 671 U.S. Government agencies and sponsored enterprises mortgage-backed securities 207,735 1,836 175,810 4,953 383,545 6,789 State and municipal obligations 192 2 23,813 717 24,005 719 Asset-backed securities 36,542 100 — — 36,542 100 Corporate bonds and other debt securities 186,052 1,240 10,842 73 196,894 1,313 Preferred stock and other equity securities 6,041 26 20,337 666 26,378 692 Total available for sale $ 468,080 $ 3,472 $ 237,959 $ 6,812 $ 706,039 $ 10,284 Less than 12 Months 12 Months or More Total December 31, 2016 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss (Dollars in thousands) Available for sale: U.S. Government agencies and sponsored enterprises obligations $ 11,577 $ 274 $ — $ — $ 11,577 $ 274 U.S. Government agencies and sponsored enterprises mortgage-backed securities 372,145 9,261 11,781 430 383,926 9,691 State and municipal obligations 25,490 578 — — 25,490 578 Asset-backed securities 11,309 21 34,855 529 46,164 550 Corporate bonds and other debt securities 179,925 3,042 77,934 2,345 257,859 5,387 Preferred stock and other equity securities 49,996 1,144 5,123 20 55,119 1,164 Total available for sale $ 650,442 $ 14,320 $ 129,693 $ 3,324 $ 780,135 $ 17,644
Summary of Gross Realized Gains and Losses on Sale of Securities Available for Sale	Gross realized gains and losses on the sale of securities available for sale are shown below. The cost of securities sold is based on the specific identification method. Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Gross realized gains $ 4,364 $ 3,645 $ 2,065 Gross realized losses (5,252 ) (2,066 ) (1,047 ) Net realized gains (losses) $ (888 ) $ 1,579 $ 1,018

Loans, Net (Tables)

Loans, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Schedule of Loans by Portfolio and Segment	The following tables summarize the Company’s loans by portfolio and segment as of the periods presented, net of deferred fees, costs, premiums and discounts: December 31, 2017 ASC 310-30 Loans Non-ASC 310-30 Loans New Loans (1) Total (Dollars in thousands) Real estate loans: Commercial real estate $ 104,335 $ 37,736 $ 2,103,788 $ 2,245,859 Owner-occupied commercial real estate — 16,100 987,781 1,003,881 1-4 single family residential 27,513 57,695 2,185,362 2,270,570 Construction, land and development 13,167 5,889 684,462 703,518 Home equity loans and lines of credit — 34,589 59,636 94,225 Total real estate loans $ 145,015 $ 152,009 $ 6,021,029 $ 6,318,053 Other loans: Commercial and industrial $ 12,631 $ 5,062 $ 1,634,372 $ 1,652,065 Consumer 1,423 259 5,984 7,666 Total other loans 14,054 5,321 1,640,356 1,659,731 Total loans held in portfolio $ 159,069 $ 157,330 $ 7,661,385 $ 7,977,784 Allowance for loan losses (47,145 ) Loans held in portfolio, net $ 7,930,639 December 31, 2016 ASC 310-30 Loans Non-ASC 310-30 Loans New Loans (1) Total (Dollars in thousands) Real estate loans: Commercial real estate $ 130,628 $ 38,786 $ 1,438,427 $ 1,607,841 Owner-occupied commercial real estate — 18,477 769,814 788,291 1-4 single family residential 31,476 66,854 2,012,856 2,111,186 Construction, land and development 17,657 6,338 651,253 675,248 Home equity loans and lines of credit — 42,295 49,819 92,114 Total real estate loans $ 179,761 $ 172,750 $ 4,922,169 $ 5,274,680 Other loans: Commercial and industrial $ 15,147 $ 5,815 $ 1,332,869 $ 1,353,831 Consumer 1,681 334 4,368 6,383 Total other loans 16,828 6,149 1,337,237 1,360,214 Total loans held in portfolio $ 196,589 $ 178,899 $ 6,259,406 $ 6,634,894 Allowance for loan losses (37,897 ) Loans held in portfolio, net $ 6,596,997 (1) Balance includes $(6.6) million and $3.2 million of net deferred fees, costs, and premium and discount as of December 31, 2017 and 2016 , respectively.
Summary of Changes in Accretable Discount for ASC 310-30 Loans	Changes in accretable discount for ASC 310-30 loans were as follows: Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Balance at January 1, $ 60,990 $ 144,152 $ 156,197 Accretion (17,523 ) (54,427 ) (55,019 ) Reclassifications from non-accretable difference (2,305 ) (28,735 ) 42,974 Balance at December 31, $ 41,162 $ 60,990 $ 144,152

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Summary of Changes in Allowance for Loan Losses by Loan Class and Portfolio Segment	Changes in the ALL by loan portfolio and segment for the years ended December 31, 2017 , 2016 , and 2015 are as follows: Commercial Real Estate Owner- Occupied Commercial Real Estate 1- 4 Single Family Residential Construction, Land and Development Home Equity Loans and Lines of Credit Commercial and Industrial Consumer Total (Dollars in thousands) Balance at January 1, 2017 $ 10,123 $ 2,597 $ 7,379 $ 4,677 $ 648 $ 12,245 $ 228 $ 37,897 Provision (credit) for ASC 310-30 loans (839 ) — 31 (51 ) — (192 ) (99 ) (1,150 ) Provision (credit) for non-ASC 310-30 loans (8 ) (6 ) (146 ) (11 ) (37 ) (64 ) (29 ) (301 ) Provision (credit) for New loans 4,723 774 720 (227 ) 73 3,260 43 9,366 Provision (credit) for Unallocated — — — — — — — 1,500 Total provision 3,876 768 605 (289 ) 36 3,004 (85 ) 9,415 Charge-offs for ASC 310-30 loans (9 ) — (35 ) (43 ) — (29 ) — (116 ) Charge-offs for non-ASC 310-30 loans (30 ) — (69 ) — (7 ) (3 ) — (109 ) Charge-offs for New loans (131 ) — — — (3 ) (150 ) — (284 ) Total charge-offs (170 ) — (104 ) (43 ) (10 ) (182 ) — (509 ) Recoveries for ASC 310-30 loans 41 — — — — 70 100 211 Recoveries for non-ASC 310-30 loans — — 98 — — 4 29 131 Recoveries for New loans — — — — — — — — Total recoveries 41 — 98 — — 74 129 342 Ending ALL balance ASC 310-30 loans 1,448 — 25 145 — 126 145 1,889 Non-ASC 310-30 loans 338 55 184 36 199 313 6 1,131 New loans 12,084 3,310 7,769 4,164 475 14,702 121 42,625 Unallocated — — — — — — — 1,500 Balance at December 31, 2017 $ 13,870 $ 3,365 $ 7,978 $ 4,345 $ 674 $ 15,141 $ 272 $ 47,145 Commercial Real Estate Owner- Occupied Commercial Real Estate 1- 4 Single Family Residential Construction, Land and Development Home Equity Loans and Lines of Credit Commercial and Industrial Consumer Total (Dollars in thousands) Balance at January 1, 2016 $ 8,450 $ 2,243 $ 6,425 $ 3,404 $ 483 $ 7,665 $ 456 $ 29,126 Provision (credit) for ASC 310-30 loans (124 ) — 3 (128 ) — (108 ) (156 ) (513 ) Provision (credit) for non-ASC 310-30 loans (1,512 ) (401 ) (31 ) 11 (21 ) 316 8 (1,630 ) Provision (credit) for New loans 2,024 756 982 1,351 213 4,440 32 9,798 Total provision 388 355 954 1,234 192 4,648 (116 ) 7,655 Charge-offs for ASC 310-30 loans (429 ) — (31 ) (33 ) — (79 ) (106 ) (678 ) Charge-offs for non-ASC 310-30 loans — (1 ) — — (35 ) — (6 ) (42 ) Charge-offs for New loans — — — — — — — — Total charge-offs (429 ) (1 ) (31 ) (33 ) (35 ) (79 ) (112 ) (720 ) Recoveries for ASC 310-30 loans 910 — 31 72 — 11 — 1,024 Recoveries for non-ASC 310-30 loans 804 — — — 8 — — 812 Recoveries for New loans — — — — — — — — Total recoveries 1,714 — 31 72 8 11 — 1,836 Ending ALL balance ASC 310-30 loans 2,255 — 29 239 — 277 144 2,944 Non-ASC 310-30 loans 376 61 301 47 243 376 6 1,410 New loans 7,492 2,536 7,049 4,391 405 11,592 78 33,543 Balance at December 31, 2016 $ 10,123 $ 2,597 $ 7,379 $ 4,677 $ 648 $ 12,245 $ 228 $ 37,897 Commercial Real Estate Owner- Occupied Commercial Real Estate 1- 4 Single Family Residential Construction, Land and Development Home Equity Loans and Lines of Credit Commercial and Industrial Consumer Total (Dollars in thousands) Balance at January 1, 2015 $ 8,206 $ 1,020 $ 4,740 $ 2,456 $ 355 $ 5,745 $ 358 $ 22,880 Provision (credit) for ASC 310-30 loans (1,487 ) — (37 ) (681 ) — (39 ) 175 (2,069 ) Provision (credit) for non-ASC 310-30 loans 589 405 46 (39 ) 138 11 6 1,156 Provision (credit) for New loans 1,012 818 2,066 1,317 122 2,417 (16 ) 7,736 Total provision 114 1,223 2,075 597 260 2,389 165 6,823 Charge-offs for ASC 310-30 loans (270 ) — (436 ) (56 ) — (643 ) (60 ) (1,465 ) Charge-offs for non-ASC 310-30 loans — — (128 ) — (132 ) — (8 ) (268 ) Charge-offs for New loans — — — — — (15 ) — (15 ) Total charge-offs (270 ) — (564 ) (56 ) (132 ) (658 ) (68 ) (1,748 ) Recoveries for ASC 310-30 loans 400 — 174 407 — 177 1 1,159 Recoveries for non-ASC 310-30 loans — — — — — — — — Recoveries for New loans — — — — — 12 — 12 Total recoveries 400 — 174 407 — 189 1 1,171 Ending ALL balance ASC 310-30 loans 1,898 — 26 328 — 453 406 3,111 Non-ASC 310-30 loans 1,084 463 332 36 291 60 4 2,270 New loans 5,468 1,780 6,067 3,040 192 7,152 46 23,745 Balance at December 31, 2015 $ 8,450 $ 2,243 $ 6,425 $ 3,404 $ 483 $ 7,665 $ 456 $ 29,126
Summary of Aging Analysis of Recorded Investment for Loans by Portfolio and Segment	The following tables present an aging analysis of the recorded investment for delinquent loans by portfolio and segment (excluding loans accounted for under ASC 310-30): Accruing December 31, 2017 30 to 59 Days Past Due 60 to 89 Days Past Due 90 Days or More Past Due Non- Accrual Total (Dollars in thousands) New loans: Real estate loans: Commercial real estate $ 324 $ — $ — $ — $ 324 Owner-occupied commercial real estate 843 150 — — 993 1-4 single family residential 1,179 1,310 — 3,167 5,656 Construction, land and development — — — — — Home equity loans and lines of credit — — — 126 126 Total real estate loans $ 2,346 $ 1,460 $ — $ 3,293 $ 7,099 Other loans: Commercial and industrial $ 4,980 $ 2,167 $ — $ — $ 7,147 Consumer — — — — — Total other loans 4,980 2,167 — — 7,147 Total New loans $ 7,326 $ 3,627 $ — $ 3,293 $ 14,246 Acquired loans: Real estate loans: Commercial real estate $ 360 $ — $ — $ 3,893 $ 4,253 Owner-occupied commercial real estate 290 — — 494 784 1-4 single family residential 892 44 — 1,331 2,267 Construction, land and development — — — — — Home equity loans and lines of credit 1,128 — — 1,720 2,848 Total real estate loans $ 2,670 $ 44 $ — $ 7,438 $ 10,152 Other loans: Commercial and industrial $ 101 $ — $ — $ 394 $ 495 Consumer — — — — — Total other loans 101 — — 394 495 Total acquired loans $ 2,771 $ 44 $ — $ 7,832 $ 10,647 Accruing December 31, 2016 30 to 59 Days Past Due 60 to 89 Days Past Due 90 Days or More Past Due Non- Accrual Total (Dollars in thousands) New loans: Real estate loans: Commercial real estate $ — $ — $ — $ 581 $ 581 Owner-occupied commercial real estate — — — — — 1-4 single family residential 1,593 — — 1,821 3,414 Construction, land and development 449 — — — 449 Home equity loans and lines of credit 255 — — 243 498 Total real estate loans $ 2,297 $ — $ — $ 2,645 $ 4,942 Other loans: Commercial and industrial $ — $ — $ — $ — $ — Consumer — — — — — Total other loans — — — — — Total New loans $ 2,297 $ — $ — $ 2,645 $ 4,942 Acquired Loans: Real estate loans: Commercial real estate $ — $ — $ — $ 4,720 $ 4,720 Owner-occupied commercial real estate 93 — — 2,502 2,595 1-4 single family residential 207 — — 2,728 2,935 Construction, land and development — — — — — Home equity loans and lines of credit 520 42 — 2,557 3,119 Total real estate loans $ 820 $ 42 $ — $ 12,507 $ 13,369 Other loans: Commercial and industrial $ — $ 128 $ — $ 325 $ 453 Consumer — — — — — Total other loans — 128 — 325 453 Total acquired loans $ 820 $ 170 $ — $ 12,832 $ 13,822
Summary of Commercial Non-ASC 310-30 and New Loans by Key Indicators of Credit Quality	The following tables summarize the Company’s commercial Non-ASC 310-30 and New loans by key indicators of credit quality. Loans accounted for under ASC 310-30 are excluded from the following analysis because their related allowance is determined by loan pool performance: December 31, 2017 Pass Special Mention Substandard Doubtful (Dollars in thousands) New loans: Commercial real estate $ 2,095,560 $ 6,066 $ 2,162 $ — Owner-occupied commercial real estate 987,781 — — — Construction, land and development 684,462 — — — Commercial and industrial 1,617,462 16,910 — — Total New loans $ 5,385,265 $ 22,976 $ 2,162 $ — Acquired loans: Commercial real estate $ 33,496 $ — $ 4,240 $ — Owner-occupied commercial real estate 15,607 — 493 — Construction, land and development 5,889 — — — Commercial and industrial 4,324 — 738 — Total acquired loans $ 59,316 $ — $ 5,471 $ — December 31, 2016 Pass Special Substandard Doubtful (Dollars in thousands) New loans: Commercial real estate $ 1,435,633 $ — $ 2,794 $ — Owner-occupied commercial real estate 769,640 174 — — Construction, land and development 651,253 — — — Commercial and industrial 1,332,869 — — — Total New loans $ 4,189,395 $ 174 $ 2,794 $ — Acquired loans: Commercial real estate $ 33,705 $ — $ 5,081 $ — Owner-occupied commercial real estate 18,388 — 89 — Construction, land and development 6,338 — — — Commercial and industrial 5,134 — 681 — Total acquired loans $ 63,565 $ — $ 5,851 $ —
Summary of Loans Based on Method for Determining Allowance	The following tables show the Company’s investment in loans disaggregated based on the method of evaluating impairment: Loans - Recorded Investment Allowance for Credit Loss December 31, 2017 Individually Evaluated for Impairment Collectively Evaluated for Impairment ASC 310- 30 Loans Individually Evaluated for Impairment Collectively Evaluated for Impairment ASC 310- 30 Loans (Dollars in thousands) New loans: Real estate loans: Commercial real estate $ — $ 2,103,788 $ — $ — $ 12,084 $ — Owner-occupied commercial real estate — 987,781 — — 3,310 — 1-4 single family residential 1,096 2,184,266 — — 7,769 — Construction, land and development — 684,462 — — 4,164 — Home equity loans and lines of credit 130 59,506 — 66 409 — Total real estate loans $ 1,226 $ 6,019,803 $ — $ 66 $ 27,736 $ — Other loans Commercial and industrial $ — $ 1,634,372 $ — $ — $ 14,702 $ — Consumer — 5,984 — — 121 — Total other loans $ — $ 1,640,356 $ — $ — $ 14,823 $ — Acquired loans: Real estate loans: Commercial real estate $ 3,893 $ 33,843 $ 104,335 $ 129 $ 209 $ 1,448 Owner-occupied commercial real estate — 16,100 — — 55 — 1-4 single family residential 267 57,428 27,513 — 184 25 Construction, land and development — 5,889 13,167 — 36 145 Home equity loans and lines of credit 495 34,094 — — 199 — Total real estate loans $ 4,655 $ 147,354 $ 145,015 $ 129 $ 683 $ 1,618 Other loans Commercial and industrial 272 4,790 12,631 272 41 126 Consumer — 259 1,423 — 6 145 Total other loans $ 272 $ 5,049 $ 14,054 $ 272 $ 47 $ 271 Total Loans: Unallocated $ — $ 7,977,784 $ — $ — $ 1,500 $ — Loans - Recorded Investment Allowance for Credit Loss December 31, 2016 Individually Evaluated for Impairment Collectively Evaluated for Impairment ASC 310- 30 Loans Individually Evaluated for Impairment Collectively Evaluated for Impairment ASC 310- 30 Loans (Dollars in thousands) New loans: Real estate loans: Commercial real estate $ 581 $ 1,437,846 $ — $ 221 $ 7,271 $ — Owner-occupied commercial real estate — 769,814 — — 2,536 — 1-4 single family residential 524 2,012,332 — — 7,049 — Construction, land and development — 651,253 — — 4,391 — Home equity loans and lines of credit 66 49,753 — 66 339 — Total real estate loans $ 1,171 $ 4,920,998 $ — $ 287 $ 21,586 $ — Other loans Commercial and industrial — 1,332,869 — — 11,592 — Consumer — 4,368 — — 78 — Total other loans $ — $ 1,337,237 $ — $ — $ 11,670 $ — Acquired Loans: Real estate loans: Commercial real estate $ 4,720 $ 34,066 $ 130,628 $ 175 $ 201 $ 2,255 Owner-occupied commercial real estate — 18,477 — — 61 — 1-4 single family residential 1,612 65,242 31,476 88 213 29 Construction, land and development — 6,338 17,657 — 47 239 Home equity loans and lines of credit 1,050 41,245 — — 243 — Total real estate loans $ 7,382 $ 165,368 $ 179,761 $ 263 $ 765 $ 2,523 Other loans Commercial and industrial 325 5,490 15,147 325 51 277 Consumer — 334 1,681 — 6 144 Total other loans $ 325 $ 5,824 $ 16,828 $ 325 $ 57 $ 421
Summary of Company's Impaired Loans Evaluated for Specific Reserves	The following tables set forth certain information regarding the Company’s impaired loans (excluding loans accounted for under ASC 310-30) that were evaluated for specific reserves: Impaired Loans - With Allowance Impaired Loans - With no Allowance December 31, 2017 Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance (Dollars in thousands) New loans: Real estate loans: Commercial real estate $ — $ — $ — $ — $ — Owner-occupied commercial real estate — — — — — 1-4 single family residential — — — 1,096 1,096 Construction, land and development — — — — — Home equity loans and lines of credit 66 66 66 63 63 Total real estate loans $ 66 $ 66 $ 66 $ 1,159 $ 1,159 Other loans Commercial and industrial — — — — — Consumer — — — — — Total other loans $ — $ — $ — $ — $ — Acquired loans: Real estate loans: Commercial real estate $ 336 $ 347 $ 129 $ 3,557 $ 4,991 Owner-occupied commercial real estate — — — — — 1-4 single family residential — — — 267 267 Construction, land and development — — — — — Home equity loans and lines of credit — — — 495 495 Total real estate loans $ 336 $ 347 $ 129 $ 4,319 $ 5,753 Other loans Commercial and industrial 272 272 272 — — Consumer — — — — — Total other loans $ 272 $ 272 $ 272 $ — $ — Impaired Loans - With Allowance Impaired Loans - With no Allowance December 31, 2016 Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance (Dollars in thousands) New loans: Real estate loans: Commercial real estate $ 581 $ 581 $ 221 $ — $ — Owner-occupied commercial real estate — — — — — 1-4 single family residential — — — 524 524 Construction, land and development — — — — — Home equity loans and lines of credit 66 66 66 — — Total real estate loans $ 647 $ 647 $ 287 $ 524 $ 524 Other loans Commercial and industrial — — — — — Consumer — — — — — Total other loans $ — $ — $ — $ — $ — Acquired loans: Real estate loans: Commercial real estate $ 630 $ 650 $ 175 $ 4,090 $ 5,397 Owner-occupied commercial real estate — — — — — 1-4 single family residential 565 512 88 1,047 1,047 Construction, land and development — — — — — Home equity loans and lines of credit — — — 1,050 1,415 Total real estate loans $ 1,195 $ 1,162 $ 263 $ 6,187 $ 7,859 Other loans Commercial and industrial 325 325 325 — — Consumer — — — — — Total other loans $ 325 $ 325 $ 325 $ — $ —
Summary of Impaired Loans Average Recorded Investment and Interest Income Recognized	Years Ended December 31, 2017 2016 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized (Dollars in thousands) Impaired loans with no related allowance: Real estate loans: Commercial real estate $ 3,653 $ — $ 4,245 $ — Owner-occupied commercial real estate — — — — 1-4 single family residential 1,363 — 816 — Construction, land and development — — — — Home equity loans and lines of credit 670 — 1,272 — Total real estate loans $ 5,686 $ — $ 6,333 $ — Other loans: Commercial and industrial — — — — Consumer — — — — Total other loans $ — $ — $ — $ — Impaired loans with an allowance: Real estate loans: Commercial real estate $ 480 $ — $ 959 $ — Owner-occupied commercial real estate — — — — 1-4 single family residential — — 424 — Construction, land and development — — — — Home equity loans and lines of credit 66 — 44 — Total real estate loans $ 546 $ — $ 1,427 $ — Other loans: Commercial and industrial 317 — 170 — Consumer — — — — Total other loans $ 317 $ — $ 170 $ —

Covered Assets and Loss Shari33

Covered Assets and Loss Sharing Agreements (Tables)	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Summary of Changes in Loss Share Indemnification Asset	Changes in the loss share indemnification asset for the periods presented were as follows: Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Balance at beginning of period $ — $ — $ 63,168 Termination of FDIC loss sharing agreements — — (63,168 ) Balance at end of period $ — $ — $ —
Summary of Changes in Clawback Liability Included Other Liabilities	The following table summarizes the changes in the clawback liability for the periods presented: Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Balance at beginning of period $ — $ — $ 13,846 Termination of FDIC loss sharing agreements — — (13,846 ) Balance at end of period $ — $ — $ —

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Components of Premises and Equipment	The major components of premises and equipment are as follows: December 31, 2017 2016 (Dollars in thousands) Land $ 7,624 $ 7,624 Building and improvements 24,653 24,653 Furniture, fixtures and equipment 14,956 13,197 Leasehold improvements 5,164 4,454 Construction in Process 663 525 Software 3,354 3,021 Total 56,414 53,474 Less: Accumulated depreciation (20,270 ) (16,822 ) Total premises and equipment, net $ 36,144 $ 36,652
Schedule of Future Minimum Rental Payments Under Non-Cancellable Operating Leases	As of December 31, 2017 , future minimum lease payments under non-cancellable operating leases were as follows (in thousands): Years Ended December 31, 2018 2019 2020 2021 2022 Thereafter Total Future minimum lease payments $ 5,205 $ 4,707 $ 4,438 $ 3,145 $ 2,398 $ 12,431 $ 32,324

Goodwill and Intangibles (Table

Goodwill and Intangibles (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Goodwill and Other Intangible Assets	Goodwill and other intangible assets are summarized as follows: December 31, 2017 2016 (Dollars in thousands) Goodwill $ 81,204 $ 81,204 Core deposit intangible 14,370 14,370 Less: Accumulated amortization (10,702 ) (9,679 ) Net core deposit intangible $ 3,668 $ 4,691
Estimated Amortization Expense for Core Deposit Intangible Assets to be Recognized	The estimated amount of amortization expense for core deposit intangible assets to be recognized over the next five fiscal years is as follows: 2018 2019 2020 2021 2022 (Dollars in thousands) Core deposit intangible $ 1,023 $ 1,023 $ 510 $ 360 $ 360

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Derivatives Outstanding Included in Other Assets and Liabilities	The following tables summarize the Company’s derivatives outstanding included in other assets and other liabilities in the accompanying consolidated balance sheets: Derivative Assets Derivative Liabilities December 31, 2017 Notional Fair Value Notional Fair Value (Dollars in thousands) Derivatives not designated as hedging instruments under ASC Topic 815-10 Interest rate swaps—pay floating, receive fixed $ 757,887 $ 11,678 $ 380,233 $ 4,180 Interest rate swaps—pay fixed, receive floating 380,233 — 757,887 7,498 Interest rate caps—purchased 94,884 155 — — Interest rate caps—sold — — 94,884 155 Total derivatives $ 1,233,004 $ 11,833 $ 1,233,004 $ 11,833 Derivative Assets Derivative Liabilities December 31, 2016 Notional Fair Value Notional Fair Value (Dollars in thousands) Derivatives not designated as hedging instruments under ASC Topic 815-10 Interest rate swaps—pay floating, receive fixed $ 708,426 $ 15,268 $ 182,848 $ 2,908 Interest rate swaps—pay fixed, receive floating 182,848 — 708,426 12,360 Total derivatives $ 891,274 $ 15,268 $ 891,274 $ 15,268
Summary of Gross and Net Fair Values of Derivatives Outstanding Included in Other Liabilities	The following table summarizes the gross and net fair values of the Company’s derivatives outstanding with this counterparty included in other liabilities in the accompanying consolidated balance sheets: December 31, 2017 Gross amounts of recognized liabilities Gross amounts offset in the consolidated balance sheets Net amounts in the consolidated balance sheets (Dollars in thousands) Offsetting derivative liabilities Counterparty A—Interest rate contracts $ 11,833 $ (4,491 ) $ 7,342 Total $ 11,833 $ (4,491 ) $ 7,342 December 31, 2016 Gross amounts of recognized liabilities Gross amounts offset in the consolidated balance sheets Net amounts in the consolidated balance sheets (Dollars in thousands) Offsetting derivative liabilities Counterparty A—Interest rate contracts $ 15,268 $ (2,908 ) $ 12,360 Total $ 15,268 $ (2,908 ) $ 12,360

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Summary of Company's Deposits by Category	The following table sets forth the Company’s deposits by category: December 31, 2017 2016 (Dollars in thousands) Noninterest-bearing demand deposits $ 1,236,685 $ 905,905 Interest-bearing demand deposits 1,454,097 1,004,452 Interest-bearing NOW accounts 363,191 398,823 Savings and money market accounts 3,013,237 2,780,697 Time deposits 2,606,717 2,215,794 Total deposits $ 8,673,927 $ 7,305,671 Time deposits $100,000 and greater $ 1,983,445 $ 1,675,162 Time deposits greater than $250,000 1,078,702 843,683

FHLB and Other Borrowings (Tabl

FHLB and Other Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Federal Home Loan Banks [Abstract]
FHLB Advances and Other Borrowings Outstanding	Advances from the FHLB and other borrowings outstanding for the periods presented are as follows: December 31, 2017 Range of Contractual Interest Rates (Dollars in thousands) Repayable during the years ending December 31, 2018 $ 270,000 1.41% - 1.59% 2019 — — % 2020 and beyond 400,000 1.34% - 2.28% Total FHLB advances 670,000 Securities sold under repurchase agreements 50,336 1.87% - 2.41% Retail repurchase agreements 28,777 0.25 % Total contractual outstanding 749,113 Fair value adjustment — Total Borrowings $ 749,113 December 31, 2016 Range of Contractual Interest Rates Repayable during the years ending December 31, 2017 $ 342,250 0.62% - 0.80% 2018 50,000 1.53 % 2019 and beyond 200,000 1.34% - 1.61% Total FHLB advances 592,250 Securities sold under repurchase agreements 131,621 1.40% - 4.35% Retail repurchase agreements 26,386 0.25 % Total contractual outstanding 750,257 Fair value adjustment 846 Total Borrowings $ 751,103

Regulatory Capital (Tables)

Regulatory Capital (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Regulatory Capital Levels	The Bank’s and Company’s regulatory capital levels are as follows: Actual Minimum Capital Requirement Minimum To Be Well Capitalized Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) December 31, 2017 Tier 1 leverage ratio Company $ 1,079,851 10.5 % $ 411,177 4.0 % $ 513,972 5.0 % Bank 927,426 9.2 % 403,527 4.0 % 504,409 5.0 % Common equity tier 1 capital ratio Company 1,079,851 11.9 % 409,482 4.5 % 591,475 6.5 % Bank 927,426 10.4 % 400,187 4.5 % 578,047 6.5 % Tier 1 risk-based capital ratio Company 1,079,851 11.9 % 545,977 6.0 % 727,969 8.0 % Bank 927,426 10.4 % 533,582 6.0 % 711,443 8.0 % Total risk-based capital ratio Company 1,128,889 12.4 % 727,969 8.0 % 909,961 10.0 % Bank 975,663 11.0 % 711,443 8.0 % 889,304 10.0 % Actual Minimum Capital Requirement Minimum To Be Well Capitalized Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) December 31, 2016 Tier 1 leverage ratio Company $ 891,584 10.3 % $ 346,518 4.0 % $ 433,148 5.0 % Bank 795,207 9.3 % 340,856 4.0 % 426,070 5.0 % Common equity tier 1 capital ratio Company 891,584 11.9 % 336,328 4.5 % 485,807 6.5 % Bank 795,207 10.9 % 329,194 4.5 % 475,503 6.5 % Tier 1 risk-based capital ratio Company 891,584 11.9 % 448,437 6.0 % 597,916 8.0 % Bank 795,207 10.9 % 438,926 6.0 % 585,234 8.0 % Total risk-based capital ratio Company 930,821 12.5 % 597,916 8.0 % 747,395 10.0 % Bank 834,679 11.4 % 585,234 8.0 % 731,543 10.0 %

Accumulated Other Comprehensi40

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of Changes in Accumulated Other Comprehensive Income	Changes in AOCI for the periods indicated are summarized as follows: Year Ended December 31, 2017 Before Tax Tax Effect Net of Tax (Dollars in thousands) Balance at beginning of period $ (6,504 ) $ 2,509 $ (3,995 ) Unrealized gain (loss) on investment securities available for sale: Net unrealized holdings gain (loss) arising during the period 24,112 (9,244 ) 14,868 Amounts reclassified to (gain) loss on investment securities (3,206 ) 1,226 (1,980 ) Balance at end of period $ 14,402 $ (5,509 ) $ 8,893 Year Ended December 31, 2016 Before Tax Tax Effect Net of Tax (Dollars in thousands) Balance at beginning of period $ (15,371 ) $ 5,928 $ (9,443 ) Unrealized gain (loss) on investment securities available for sale: Net unrealized holdings gain (loss) arising during the period 11,582 (4,467 ) 7,115 Amounts reclassified to (gain) loss on investment securities (2,715 ) 1,048 (1,667 ) Balance at end of period $ (6,504 ) $ 2,509 $ (3,995 ) Year Ended December 31, 2015 Before Tax Tax Effect Net of Tax (Dollars in thousands) Balance at beginning of period $ 1,106 $ (427 ) $ 679 Unrealized gain (loss) on investment securities available for sale: Net unrealized holdings gain (loss) arising during the period (13,997 ) 5,399 (8,598 ) Amounts reclassified to (gain) loss on investment securities (2,480 ) 956 (1,524 ) Balance at end of period $ (15,371 ) $ 5,928 $ (9,443 )

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of Activity of Warrants	The following table presents the activity during the year ended December 31, 2017 related to the Amended 2009 Warrants: Amended 2009 Warrants Warrants Weighted Average Exercise Price Aggregate Intrinsic Value Weighted Average Remaining Contractual Life (Years) (Dollars in thousands, except per share data) Outstanding at January 1, 2017 2,685,927 $ 26.48 Granted — — Exercised (1,411,905 ) 26.24 $ 31,895 Forfeited — — Expired — — Outstanding at December 31, 2017 1,274,022 26.75 30,640 1.87 Exercisable at December 31, 2017 1,274,022 26.75 30,640 1.87 Vested at December 31, 2017 1,274,022 26.75 30,640 1.87 Vested and expected to vest at December 31, 2017 1,274,022 26.75 30,640 1.87

Stock-Based Compensation and 42

Stock-Based Compensation and Other Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2017
2009 Equity Incentive Plan
Schedule of Option Activity	The following tables present the activity during the year ended December 31, 2017 related to the 2009 Option Plan: 2009 Option Plan Options Weighted Average Exercise Price Aggregate Intrinsic Value Weighted Average Remaining Contractual Life (Years) (Dollars in thousands, except per share data) Outstanding at January 1, 2017 3,107,235 $ 20.62 Granted — — Exercised (1,768,652 ) 20.58 $ 47,180 Forfeited (21,322 ) 22.72 Expired (2,337 ) 22.97 Outstanding at December 31, 2017 1,314,924 20.65 39,651 4.49 Exercisable at December 31, 2017 1,314,924 20.65 39,651 4.49 Vested at December 31, 2017 1,314,924 20.65 39,651 4.49 Vested and expected to vest at December 31, 2017 1,314,924 20.65 39,651 4.49
Summary of Stock-Based Compensation Expense	A summary of selected data related to stock-based compensation expense follows: 2009 Option Plan Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Stock-based compensation expense $ 760 $ 1,707 $ 2,239 Tax benefit realized from stock awards exercised 19,070 3,622 1,618 Fair value of stock-based awards that vested during the year 1,075 1,882 2,724 Amount of cash received from exercise of awards 36,392 11,427 8,163 Total intrinsic value of awards exercised during the year 47,180 9,547 4,940 2009 Option Plan December 31, 2017 2016 2015 (Dollars in thousands) Unrecognized compensation expense related to stock-based compensation $ — $ 569 $ 2,561 Weighted-average life over which expense is expected to be recognized (years) 0.00 0.78 1.72
2013 Stock Incentive Plan
Schedule of Option Activity	The following tables present the activity during the year ended December 31, 2017 related to the 2013 Plan Options: 2013 Plan Options Options Weighted Average Exercise Price Aggregate Intrinsic Value Weighted Average Remaining Contractual Life (Years) (Dollars in thousands, except per share data) Outstanding at January 1, 2017 2,164,258 $ 20.63 Granted — — Exercised (725,970 ) 20.18 $ 20,633 Forfeited (13,335 ) 27.23 Expired — — Outstanding at December 31, 2017 1,424,953 20.79 42,764 6.21 Exercisable at December 31, 2017 1,408,115 20.71 42,372 6.20 Vested at December 31, 2017 1,408,115 20.71 42,372 6.20 Vested and expected to vest at December 31, 2017 1,424,953 20.79 42,764 6.21
Summary of Stock-Based Compensation Expense	A summary of selected data related to stock-based compensation expense follows: 2013 Plan Options Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Stock-based compensation expense $ 226 $ 1,655 $ 2,002 Tax benefit realized from stock awards exercised 8,019 1,380 158 Grant date fair value of stock-based awards that vested during the year 3,732 4,313 1,181 Amount of cash received from exercise of option awards 14,652 5,186 714 Total intrinsic value of awards exercised during the year 20,633 3,888 465 2013 Plan Options December 31, 2017 2016 2015 (Dollars in thousands) Unrecognized compensation expense related to stock-based compensation $ 41 $ 333 $ 1,633 Weighted-average life over which expense is expected to be recognized (years) 0.28 1.24 1.53
Summary of Assumptions used to Calculate Fair Values	A summary of assumptions used to calculate the fair values of the 2013 Plan Options awards is presented below: 2013 Plan Options Years Ended December 31, 2017 2016 2015 Expected volatility — % 24.7 % 31.1 % Expected dividend yield — % 1.25 % 1.25 % Expected term (years) 0.0 6.0 6.2 Risk-free interest rate — % 1.37 % 1.63 % Weighted average grant date fair value $ — $ 6.57 $ 7.38
2016 Stock Incentive Plan - Stock Options
Schedule of Option Activity	The following tables present the activity during the year ended December 31, 2017 related to the 2016 Plan Options: 2016 Plan Options Options Weighted Average Exercise Price Aggregate Intrinsic Value Weighted Average Remaining Contractual Life (Years) (Dollars in thousands, except per share data) Outstanding at January 1, 2017 827,500 $ 36.11 Granted 37,500 46.89 Exercised — — $ — Forfeited (102,500 ) 36.11 Expired — — Outstanding at December 31, 2017 762,500 36.64 10,797 8.64 Exercisable at December 31, 2017 — — — — Vested at December 31, 2017 — — — — Vested and expected to vest at December 31, 2017 762,500 36.64 10,797 8.64
Summary of Stock-Based Compensation Expense	A summary of selected data related to stock-based compensation expense for the year ended December 31, 2017 are as follows: 2016 Plan Options December 31, 2017 2016 (Dollars in thousands) Stock-based compensation expense $ 1,431 $ 570 Unrecognized compensation expense related to stock-based compensation 4,882 6,563 Weighted-average life over which expense is expected to be recognized (years) 3.66 4.61
Summary of Assumptions used to Calculate Fair Values	A summary of assumptions used to calculate the fair values of the 2016 Plan Options awards is presented below: 2016 Plan Options December 31, 2017 2016 Expected volatility 22.6% - 23.4% 24.0 % Expected dividend yield 1.25 % 1.25 % Expected term (years) 7.5 7.5 Risk-free interest rate 2.04% - 2.17% 1.42 % Weighted average grant date fair value $ 11.73 $ 8.62
2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards
Summary of Stock-Based Compensation Expense	A summary of selected data related to stock-based compensation expense for the year ended December 31, 2017 are as follows: Restricted Stock Awards Restricted Stock Unit Awards Performance Restricted Stock Unit Awards December 31, December 31, December 31, 2017 2016 2017 2016 2017 2016 (Dollars in thousands) Stock-based compensation expense $ 3,672 $ 1,393 $ 1,225 $ — $ 968 $ — Unrecognized compensation expense related to stock-based compensation $ 3,113 $ 2,785 $ 4,051 $ — $ 2,532 $ — Weighted-average life over which expense is expected to be recognized (years) 1.31 2.00 4.88 0.00 2.00 0.00
Schedule of Equity Option Activity	The following tables present the activity during the year ended December 31, 2017 related to restricted stock from the 2016 Plan: 2016 Stock Incentive Plan Restricted Stock Awards Restricted Stock Unit Awards Performance Restricted Stock Unit Awards Shares Weighted Average Grant Date Fair Value Shares Weighted Average Grant Date Fair Value Shares Weighted Average Grant Date Fair Value (Dollars in thousands, except per share data) Outstanding at January 1, 2017 80,808 $ 34.47 — $ — — $ — Granted 83,593 47.85 106,615 49.49 73,144 47.85 Vested (68,268 ) 39.93 (18,600 ) 45.45 — — Canceled or forfeited — — — — — — Outstanding at December 31, 2017 96,133 42.23 88,015 50.34 73,144 47.85

Basic and Diluted Earnings Pe43

Basic and Diluted Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Share	The following table presents the computation of basic and diluted EPS: Years Ended December 31, 2017 2016 2015 (Dollars in thousands, except share and per share data) Net income available to common stockholders $ 125,194 $ 99,916 $ 53,391 Weighted average number of common shares—basic 42,887,142 40,716,588 41,300,979 Effect of dilutive securities: Employee stock-based compensation awards and warrants 3,233,788 2,508,576 1,992,628 Weighted average number of common shares—diluted 46,120,930 43,225,164 43,293,607 Basic earnings per share $ 2.92 $ 2.45 $ 1.29 Diluted earnings per share $ 2.71 $ 2.31 $ 1.23 Weighted average number of anti-dilutive equity awards 29,114 330,095 91,923

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Components of Expense and Benefit for Income Taxes	The components of the expense and benefit for income taxes for the periods presented are as follows: Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Current income tax expense: Federal $ 24,036 $ 39,528 $ 23,610 State 3,800 6,013 3,441 Total current income tax expense 27,836 45,541 27,051 Deferred income tax expense (benefit): Federal 24,795 9,161 (19,157 ) State 1,534 1,203 (2,238 ) Total deferred income tax expense (benefit) 26,329 10,364 (21,395 ) Total income tax expense (benefit) $ 54,165 $ 55,905 $ 5,656
Reconciliation of Expected Income Tax Expense or Benefit at Statutory Federal Income Tax Rate to Actual Income Tax Expense or Benefit and Effective Tax Rate	A reconciliation of the expected income tax expense or benefit at the statutory federal income tax rate of 35% to the Company’s actual income tax expense or benefit and effective tax rate for the periods presented is as follows: Years Ended December 31, 2017 2016 2015 Amount % Amount % Amount % (Dollars in thousands) Tax expense (benefit) at federal income tax rate $ 62,776 35.00 % $ 54,537 35.00 % $ 20,667 35.00 % Increase (decrease) resulting from: Bank-owned life insurance (3,186 ) (1.78 )% (1,817 ) (1.17 )% (1,614 ) (2.73 )% Stock compensation and excess tax benefit (20,098 ) (11.21 )% 234 0.15 % 729 1.23 % Dividends received deduction (1,631 ) (0.91 )% (1,919 ) (1.23 )% (2,104 ) (3.56 )% GFB NUBIL Revaluation — — % — — % (4,954 ) (8.39 )% NOL Valuation Allowance — — % — — % (9,061 ) (15.35 )% State tax, net of federal benefit 3,528 1.97 % 4,777 3.07 % 1,619 2.74 % Federal tax rate change 14,301 7.97 % — — % — — % Other (1,525 ) (0.85 )% 93 0.06 % 374 0.62 % Total $ 54,165 30.19 % $ 55,905 35.88 % $ 5,656 9.56 %
Significant Components of Net Deferred Tax Assets and Liabilities	The significant components of the net deferred tax assets and liabilities for the periods presented are as follows: December 31, 2017 2016 (Dollars in thousands) Deferred tax assets: Excess tax basis over carrying value of assets: Other real estate owned $ 1,456 $ 12,991 Total 1,456 12,991 Excess carrying value over tax basis of liabilities: Repo Loans — 324 Total — 324 Net operating loss carry forward: Federal 5,755 9,287 State 534 921 Total 6,289 10,208 Amortization 11,717 21,555 Depreciation — 660 Unrealized losses on securities available for sale — 2,509 Allowance for loan losses 11,087 12,807 Non-qualified stock options and restricted stock 3,869 7,695 Other 469 2,696 Gross deferred tax assets 34,887 71,445 Valuation allowance — — Gross deferred tax assets, net of valuation allowance 34,887 71,445 Deferred tax liabilities: Loans (947 ) (7,542 ) Depreciation (239 ) — Restricted securities (1,475 ) (2,260 ) Unrealized gains on securities available for sale (3,594 ) — Other (1,589 ) (252 ) Gross deferred tax liabilities (7,844 ) (10,054 ) Deferred tax assets (liabilities), net $ 27,043 $ 61,391

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Summary of Unfunded Commitments	Unfunded commitments are as follows: December 31, 2017 2016 (Dollars in thousands) Commitments to fund loans $ 926,405 $ 724,380 Unused lines of credit 571,587 410,068 Commercial and standby letters of credit 46,520 26,200 Total $ 1,544,512 $ 1,160,648

Parent Company Financial Stat46

Parent Company Financial Statements (Tables) - Parent company	12 Months Ended
	Dec. 31, 2017
Condensed Balance Sheets	Condensed Balance Sheets of FCB Financial Holdings, Inc. (Parent company only) for the periods presented are as follows: PARENT COMPANY CONDENSED BALANCE SHEETS December 31, 2017 2016 (Dollars in thousands) Assets: Cash and due from banks $ 10,271 $ 18,126 Available for sale securities 179,815 129,970 Investment in bank subsidiary 1,025,677 885,296 Other assets 13,894 9,874 Total assets $ 1,229,657 $ 1,043,266 Liabilities and stockholders’ equity: Total liabilities 50,783 61,182 Stockholders’ equity 1,178,874 982,084 Total liabilities and stockholders’ equity $ 1,229,657 $ 1,043,266
Condensed Statements of Income	Condensed Statements of Income of FCB Financial Holdings, Inc. (Parent company only) for the periods presented are as follows: PARENT COMPANY CONDENSED STATEMENTS OF INCOME Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Income: Interest and dividends on investment securities $ 8,079 $ 7,831 $ 8,602 Gain (loss) on investment securities 2,032 (586 ) 688 Total income 10,111 7,245 9,290 Expense: Interest on borrowings 770 884 551 Stock-based compensation expense 1,126 577 829 Professional services 922 707 950 Directors fees 401 800 598 Insurance expense 768 1,034 1,505 Other noninterest expense 8,372 7,261 6,500 Total expense 12,359 11,263 10,933 Income (loss) before income taxes and equity in undistributed income of subsidiaries (2,248 ) (4,018 ) (1,643 ) Income tax expense (benefit) (5,494 ) (3,671 ) (2,901 ) Income (loss) before equity in undistributed income of subsidiaries 3,246 (347 ) 1,258 Equity in income of subsidiary 121,948 100,263 52,133 Net income $ 125,194 $ 99,916 $ 53,391
Condensed Statements of Comprehensive Income	Condensed Statements of Comprehensive Income of FCB Financial Holdings, Inc. (Parent company only) for periods presented are as follows: PARENT COMPANY CONDENSED STATEMENTS OF COMPREHENSIVE INCOME Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Net income $ 125,194 $ 99,916 $ 53,391 Other comprehensive income (loss): Unrealized net holding gains (losses) on investment securities available for sale, net of taxes of $(1,644), $(620), and $(227), respectively 2,685 988 362 Reclassification adjustment for (gains) losses on investment securities available for sale included in net income, net of taxes of $1,050, $63, and $384, respectively (1,696 ) (100 ) (612 ) Total other comprehensive income (loss) 989 888 (250 ) Total comprehensive income $ 126,183 $ 100,804 $ 53,141
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows of FCB Financial Holdings, Inc. (Parent company only) for periods presented are as follows: PARENT COMPANY CONDENSED STATEMENTS OF CASH FLOWS Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Cash flows from operating activities: Net income $ 125,194 $ 99,916 $ 53,391 Adjustments to reconcile net income to net cash used in operating activities: Equity in earnings of subsidiaries (121,948 ) (100,263 ) (52,133 ) Amortization (accretion) of premium (discount) on investment securities (13 ) — — (Gain) loss on investment securities (2,032 ) 586 (688 ) Stock-based compensation and warrant expense 1,124 577 829 Depreciation of premises and equipment — — 1 Deferred tax expense 3,126 (735 ) 1,272 Net change in operating assets and liabilities: (Increase)/decrease in due from subsidiaries (472 ) 4,478 8,476 Increase/(decrease) in due to subsidiaries (1,745 ) 1,745 (1,979 ) Net change in other assets 1,332 1,382 1,052 Net change in other liabilities (8,109 ) (4,365 ) (2,806 ) Net cash provided by (used in) operating activities (3,543 ) 3,321 7,415 Cash flows from investing activities: Purchases of investment securities available for sale (102,988 ) (67,934 ) (169,728 ) Sales of investment securities available for sale 56,791 106,347 110,649 Payments and maturities of investment securities — — 2,005 Capital contribution — — (35,000 ) Net cash provided by (used in) investing activities (46,197 ) 38,413 (92,074 ) Cash flows from financing activities: Repurchase common stock — (23,738 ) (34,884 ) Exercise of stock options 50,670 17,042 8,793 Excess tax benefit from share-based payments — 2,110 2,048 Net change in repurchase agreements (8,785 ) (28,134 ) 87,254 Net cash provided by (used in) financing activities 41,885 (32,720 ) 63,211 Net Change in Cash (7,855 ) 9,014 (21,448 ) Cash at Beginning of Period 18,126 9,112 30,560 Cash at End of Period $ 10,271 $ 18,126 $ 9,112

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following table presents the assets and liabilities measured at fair value on a recurring basis: December 31, 2017 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: U.S. Government agencies and sponsored enterprises obligations $ — $ 42,838 $ — $ 42,838 U.S. Government agencies and sponsored enterprises mortgage-backed securities — 595,237 — 595,237 State and municipal obligations — 26,172 — 26,172 Asset-backed securities — 610,546 — 610,546 Corporate bonds and other debt securities 55,970 699,933 — 755,903 Preferred stocks and other equity securities 12,954 77,153 — 90,107 Derivative assets—Interest rate contracts 11,833 — 11,833 Total $ 68,924 $ 2,063,712 $ — $ 2,132,636 Liabilities: Derivative liabilities—Interest rate contracts $ — $ 11,833 $ — $ 11,833 Total $ — $ 11,833 $ — $ 11,833 December 31, 2016 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: U.S. Government agencies and sponsored enterprises obligations $ — $ 16,314 $ — $ 16,314 U.S. Government agencies and sponsored enterprises mortgage-backed securities — 558,446 — 558,446 State and municipal obligations — 27,679 — 27,679 Asset-backed securities — 577,823 — 577,823 Corporate bonds and other debt securities 53,517 505,777 — 559,294 Preferred stocks and other equity securities 6,908 129,970 — 136,878 Derivative assets—Interest rate contracts — 15,268 — 15,268 Total $ 60,425 $ 1,831,277 $ — $ 1,891,702 Liabilities: Derivative liabilities—Interest rate contracts $ — $ 15,268 $ — $ 15,268 Total $ — $ 15,268 $ — $ 15,268
Schedule of Changes in Fair Value of Liabilities Measured at Fair Value on Recurring Basis and Classified in Level 3 of Fair Value Hierarchy for Periods Presented	The following table reconciles changes in the fair value of liabilities measured at fair value on a recurring basis and classified in level 3 of the fair value hierarchy for the periods presented: Years Ended December 31, 2017 2016 2015 Clawback Liability Clawback Liability Clawback Liability (Dollars in thousands) Balance at beginning of period $ — $ — $ 13,846 Termination of FDIC loss sharing agreements — — (13,846 ) Balance at end of period $ — $ — $ —
Significant Unobservable Inputs in Fair Value Measurement Level 3 Assets and Liabilities	The following table shows significant unobservable inputs used in the non-recurring fair value measurement of level 3 assets and liabilities: Level 3 Assets: December 31, 2017 December 31, 2016 Valuation Technique Unobservable Inputs Range (Weighted Average) (Dollars in thousands) Impaired loans $ 6,153 $ 8,878 Third party appraisals and discounted cash flows Collateral discounts and discount rates 0% - 100% (7.6%) Other real estate owned 14,906 19,228 Third party appraisals Collateral discounts and estimated cost to sell 10 %
Summary of Fair Value Measurements Related to Collateral Dependent Impaired Loans and OREO are Classified within Level 3 of the Fair Value Hierarchy	The following table provides information about certain assets measured at fair value on a non-recurring basis: Years Ended December 31, 2017 2016 2015 (Dollars in thousands) Negative valuation adjustments: Impaired loans $ — $ 700 $ 1,071 Foreclosed real estate 670 1,219 674
Schedule of Carrying Amounts and Estimated Fair Values, as well as the Level within the Fair Value Hierarchy	The carrying amounts and estimated fair values, as well as the level within the fair value hierarchy, of the Company’s financial instruments are as follows: December 31, 2017 Carrying Value Fair Value Level 1 Level 2 Level 3 (Dollars in thousands) Financial Assets: Cash and cash equivalents $ 115,921 $ 115,921 $ 115,921 $ — $ — Available for sale securities 2,120,803 2,120,803 68,924 2,051,879 — FHLB and other bank stock 56,881 56,881 — 56,881 — Loans, net 7,930,639 7,877,094 — — 7,877,094 Loans held for sale 12,736 12,736 — 12,736 — Bank-owned life insurance 201,069 201,069 — 201,069 — Derivative assets—Interest rate contracts 11,833 11,833 — 11,833 — Financial Liabilities: Deposits $ 8,673,927 $ 8,664,125 $ — $ 8,664,125 $ — Advances from the FHLB and other borrowings 749,113 740,941 — 740,941 — Derivative liabilities—Interest rate contracts 11,833 11,833 — 11,833 — December 31, 2016 Carrying Value Fair Value Level 1 Level 2 Level 3 (Dollars in thousands) Financial Assets: Cash and cash equivalents $ 83,876 $ 83,876 $ 83,876 $ — $ — Available for sale securities 1,876,434 1,876,434 60,425 1,816,009 — FHLB and other bank stock 51,656 51,656 — 51,656 — Loans, net 6,596,997 6,556,914 — — 6,556,914 Loans held for sale 20,220 20,220 — 20,220 — Bank-owned life insurance 198,438 198,438 — 198,438 — Derivative assets—Interest rate contracts 15,268 15,268 — 15,268 — Financial Liabilities: Deposits $ 7,305,671 $ 7,306,148 $ — $ 7,306,148 $ — Advances from the FHLB and other borrowings 751,103 745,855 — 745,855 — Derivative liabilities—Interest rate contracts 15,268 15,268 — 15,268 —

Quarterly Financial Data (Una48

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Financial Data	The information below is only a summary and should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and the consolidated historical financial statements and the related notes thereto included in this Form 10-K filing. Quarters Ended December 31, 2017 Q4 Q3 Q2 Q1 (Dollars in thousands, except per share data) Selected Income Statement data: Interest income $ 101,490 $ 96,816 $ 90,573 $ 85,222 Interest expense 23,376 21,035 18,686 15,552 Net interest income 78,114 75,781 71,887 69,670 Provision for loan losses 2,786 2,871 2,115 1,643 Net interest income after provision for loan losses 75,328 72,910 69,772 68,027 Noninterest income 7,731 8,425 8,873 9,987 Noninterest expense 36,119 35,239 35,252 35,084 Income before income tax expense 46,940 46,096 43,393 42,930 Income tax expense 27,976 13,936 8,312 3,941 Net income $ 18,964 $ 32,160 $ 35,081 $ 38,989 Earnings per share: Basic $ 0.43 $ 0.74 $ 0.82 $ 0.93 Diluted $ 0.41 $ 0.70 $ 0.76 $ 0.86 Quarters Ended December 31, 2016 Q4 Q3 Q2 Q1 (Dollars in thousands, except per share data) Selected Income Statement data: Interest income $ 85,580 $ 80,800 $ 77,208 $ 75,728 Interest expense 14,514 13,522 12,278 11,286 Net interest income 71,066 67,278 64,930 64,442 Provision for loan losses 2,249 1,990 1,976 1,440 Net interest income after provision for loan losses 68,817 65,288 62,954 63,002 Noninterest income 7,919 8,142 8,222 5,434 Noninterest expense 33,646 33,036 33,975 33,300 Income before income tax expense 43,090 40,394 37,201 35,136 Income tax expense 15,194 14,330 13,697 12,684 Net income $ 27,896 $ 26,064 $ 23,504 $ 22,452 Earnings per share: Basic $ 0.68 $ 0.64 $ 0.58 $ 0.55 Diluted $ 0.64 $ 0.60 $ 0.55 $ 0.52

Summary of Significant Accoun49

Summary of Significant Accounting Policies - Additional Information (Detail)	Aug. 06, 2014$ / sharesshares	Dec. 31, 2017USD ($)SegmentsSubsidiaryBankingCentersLoan_Gradeshares	Dec. 31, 2016USD ($)Loan_Grade	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Schedule Of Significant Accounting Policies [Line Items]
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount		$ 22,000,000
Number of wholly owned subsidiary | Subsidiary		1
Number of banking centers | BankingCenters		46
Aggregate unpaid principal balance		$ 399,000	$ 456,000
Proceeds from sale of loan		11,700,000	75,300,000
Sale of loans, Interest income		3,300,000	27,200,000
Loans, threshold for individual impairment testing		250,000
Impairment of goodwill		$ 0
Number of reportable segment | Segments		1
Stockholders’ equity		$ 1,179,172,000	$ 982,441,000	$ 876,109,000	$ 851,653,000
Tax Cuts and Jobs Act of 2017 stranded tax effect		$ 1,900,000
2016 Stock Incentive Plan - Stock Options | Class A common stock
Schedule Of Significant Accounting Policies [Line Items]
Common stock, capital shares reserved for future issuance (in shares) | shares		2,000,000
Bank premises
Schedule Of Significant Accounting Policies [Line Items]
Premises and equipment, useful life		39 years
Furniture and equipment
Schedule Of Significant Accounting Policies [Line Items]
Premises and equipment, useful life		5 years
IPO | Class A common stock
Schedule Of Significant Accounting Policies [Line Items]
Common stock, shares issued (in shares) | shares	7,520,000
Common stock, shares issued (in dollars per share) | $ / shares	$ 22
Unpaid principal balance
Schedule Of Significant Accounting Policies [Line Items]
Number of pools carrying values previously reduced to zero (in pools) | Loan_Grade		6	6
Core deposit intangible
Schedule Of Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets		10 years
Asset impairment charges		$ 0	$ 0	0
Minimum | Computer equipment and software
Schedule Of Significant Accounting Policies [Line Items]
Premises and equipment, useful life		3 years
Minimum | IPO | 2013 Stock Incentive Plan | 2013 Stock Options
Schedule Of Significant Accounting Policies [Line Items]
Initial public offering		$ 100,000,000
Maximum | Computer equipment and software
Schedule Of Significant Accounting Policies [Line Items]
Premises and equipment, useful life		5 years
Retained Earnings
Schedule Of Significant Accounting Policies [Line Items]
Stockholders’ equity		$ 313,645,000	$ 188,451,000	$ 88,535,000	$ 35,144,000
Accounting Standards Update 2016-01 | Retained Earnings
Schedule Of Significant Accounting Policies [Line Items]
Stockholders’ equity		1,600,000
Accounting Standards Update 2016-01 | Accumulated Net Investment Gain (Loss) Attributable to Parent
Schedule Of Significant Accounting Policies [Line Items]
Stockholders’ equity		$ 1,600,000

Investment Securities - Summary

Investment Securities - Summary of Amortized Cost, Gross Unrealized Gains and Losses and Approximate Fair Values of Securities Available for Sale (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities, amortized cost	$ 2,106,401	$ 1,882,938
Available for sale securities, unrealized gains	24,686	11,140
Available for sale securities, unrealized losses	10,284	17,644
Available for sale securities, at fair value	2,120,803	1,876,434
U.S. Government agencies and sponsored enterprises obligations
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities, amortized cost	43,471	16,512
Available for sale securities, unrealized gains	38	76
Available for sale securities, unrealized losses	671	274
Available for sale securities, at fair value	42,838	16,314
U.S. Government agencies and sponsored enterprises mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities, amortized cost	600,310	566,377
Available for sale securities, unrealized gains	1,716	1,760
Available for sale securities, unrealized losses	6,789	9,691
Available for sale securities, at fair value	595,237	558,446
State and municipal obligations
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities, amortized cost	26,766	28,109
Available for sale securities, unrealized gains	125	148
Available for sale securities, unrealized losses	719	578
Available for sale securities, at fair value	26,172	27,679
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities, amortized cost	608,340	574,521
Available for sale securities, unrealized gains	2,306	3,852
Available for sale securities, unrealized losses	100	550
Available for sale securities, at fair value	610,546	577,823
Corporate bonds and other debt securities
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities, amortized cost	738,994	560,191
Available for sale securities, unrealized gains	18,222	4,490
Available for sale securities, unrealized losses	1,313	5,387
Available for sale securities, at fair value	755,903	559,294
Preferred stocks and other equity securities
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities, amortized cost	88,520	137,228
Available for sale securities, unrealized gains	2,279	814
Available for sale securities, unrealized losses	692	1,164
Available for sale securities, at fair value	$ 90,107	$ 136,878

Investment Securities - Additio

Investment Securities - Additional Information (Detail) $ in Millions	Dec. 31, 2017USD ($)Securities	Dec. 31, 2016USD ($)
Investments, Debt and Equity Securities [Abstract]
Carrying value of pledged securities | $	$ 834.9	$ 594
Security portfolio consisted	352
Securities were in an unrealized loss position	143
Unrealized loss position for less than 12 months	85

Investment Securities - Schedul

Investment Securities - Schedule of Amortized Cost and Estimated Fair Value of Securities Available for Sale (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Available for sale, due in one year or less at amortized cost	$ 58,061
Available for sale, due after one year through five years at amortized cost	225,134
Available for sale, due after five years through ten years at amortized cost	177,272
Available for sale, due after ten years at amortized cost	305,293
U.S. Government agencies and sponsored enterprises obligations, mortgage-backed securities and tax-exempt mortgage securities, and asset-backed securities at amortized cost	1,252,121
Preferred stock and other equity securities, amortized cost	88,520
Available for sale securities, amortized cost	2,106,401	$ 1,882,938
Available for sale securities, due in one year or less at fair value	58,605
Available for sale securities, due after one year through five years at fair value	228,557
Available for sale securities, due after 5 years through 10 years at fair value	177,697
Available for sale securities, due after 10 years at fair value	317,216
U.S. Government agencies and sponsored enterprises obligations, mortgage-backed securities and tax-exempt mortgage securities, and asset-backed securities at fair value	1,248,621
Preferred stock and other equity securities, fair value	90,107
Available for sale securities, at fair value	$ 2,120,803	$ 1,876,434

Investment Securities - Summa53

Investment Securities - Summary of Estimated Fair Values and Gross Unrealized Losses on Investment Securities Available for Sale (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities at fair value, less than 12 months	$ 468,080	$ 650,442
Available for sale securities unrealized loss, less than 12 months	3,472	14,320
Available for sale securities at fair value, 12 months or more	237,959	129,693
Available for sale securities unrealized loss, 12 months or more	6,812	3,324
Available for sale securities, total fair value	706,039	780,135
Available for sale securities, total unrealized loss	10,284	17,644
U.S. Government agencies and sponsored enterprises obligations
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities at fair value, less than 12 months	31,518	11,577
Available for sale securities unrealized loss, less than 12 months	268	274
Available for sale securities at fair value, 12 months or more	7,157	0
Available for sale securities unrealized loss, 12 months or more	403	0
Available for sale securities, total fair value	38,675	11,577
Available for sale securities, total unrealized loss	671	274
U.S. Government agencies and sponsored enterprises mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities at fair value, less than 12 months	207,735	372,145
Available for sale securities unrealized loss, less than 12 months	1,836	9,261
Available for sale securities at fair value, 12 months or more	175,810	11,781
Available for sale securities unrealized loss, 12 months or more	4,953	430
Available for sale securities, total fair value	383,545	383,926
Available for sale securities, total unrealized loss	6,789	9,691
State and municipal obligations
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities at fair value, less than 12 months	192	25,490
Available for sale securities unrealized loss, less than 12 months	2	578
Available for sale securities at fair value, 12 months or more	23,813	0
Available for sale securities unrealized loss, 12 months or more	717	0
Available for sale securities, total fair value	24,005	25,490
Available for sale securities, total unrealized loss	719	578
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities at fair value, less than 12 months	36,542	11,309
Available for sale securities unrealized loss, less than 12 months	100	21
Available for sale securities at fair value, 12 months or more	0	34,855
Available for sale securities unrealized loss, 12 months or more	0	529
Available for sale securities, total fair value	36,542	46,164
Available for sale securities, total unrealized loss	100	550
Corporate bonds and other debt securities
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities at fair value, less than 12 months	186,052	179,925
Available for sale securities unrealized loss, less than 12 months	1,240	3,042
Available for sale securities at fair value, 12 months or more	10,842	77,934
Available for sale securities unrealized loss, 12 months or more	73	2,345
Available for sale securities, total fair value	196,894	257,859
Available for sale securities, total unrealized loss	1,313	5,387
Preferred stocks and other equity securities
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities at fair value, less than 12 months	6,041	49,996
Available for sale securities unrealized loss, less than 12 months	26	1,144
Available for sale securities at fair value, 12 months or more	20,337	5,123
Available for sale securities unrealized loss, 12 months or more	666	20
Available for sale securities, total fair value	26,378	55,119
Available for sale securities, total unrealized loss	$ 692	$ 1,164

Investment Securities - Summa54

Investment Securities - Summary of Gross Realized Gains and Losses on Sale of Securities Available for Sale (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Gross realized gains	$ 4,364	$ 3,645	$ 2,065
Gross realized losses	(5,252)	(2,066)	(1,047)
Net realized gains (losses)	$ (888)	$ 1,579	$ 1,018

Loans, Net - Schedule of Loans

Loans, Net - Schedule of Loans by Portfolio and Segment (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	$ 7,977,784	$ 6,634,894
Allowance for loan losses	(47,145)	(37,897)	$ (29,126)	$ (22,880)
Loans, net	7,930,639	6,596,997
Total real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	6,318,053	5,274,680
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	2,245,859	1,607,841
Allowance for loan losses	(13,870)	(10,123)	(8,450)	(8,206)
Owner-occupied commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	1,003,881	788,291
Allowance for loan losses	(3,365)	(2,597)	(2,243)	(1,020)
1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	2,270,570	2,111,186
Allowance for loan losses	(7,978)	(7,379)	(6,425)	(4,740)
Construction, land and development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	703,518	675,248
Allowance for loan losses	(4,345)	(4,677)	(3,404)	(2,456)
Home equity loans and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	94,225	92,114
Allowance for loan losses	(674)	(648)	(483)	(355)
Total other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	1,659,731	1,360,214
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	1,652,065	1,353,831
Allowance for loan losses	(15,141)	(12,245)	(7,665)	(5,745)
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	7,666	6,383
Allowance for loan losses	(272)	(228)	(456)	$ (358)
Acquired loans portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	316,399	375,488
Allowance for loan losses	(1,131)	(1,410)	(2,270)
Acquired loans portfolio segment | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	159,069	196,589
Allowance for loan losses	(1,889)	(2,944)	(3,111)
Acquired loans portfolio segment | Non-ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	157,330	178,899
Acquired loans portfolio segment | Total real estate loans | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	145,015	179,761
Allowance for loan losses	(1,618)	(2,523)
Acquired loans portfolio segment | Total real estate loans | Non-ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	152,009	172,750
Acquired loans portfolio segment | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	(338)	(376)	(1,084)
Acquired loans portfolio segment | Commercial real estate | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	104,335	130,628
Allowance for loan losses	(1,448)	(2,255)	(1,898)
Acquired loans portfolio segment | Commercial real estate | Non-ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	37,736	38,786
Acquired loans portfolio segment | Owner-occupied commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	(55)	(61)	(463)
Acquired loans portfolio segment | Owner-occupied commercial real estate | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	0	0
Allowance for loan losses	0	0	0
Acquired loans portfolio segment | Owner-occupied commercial real estate | Non-ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	16,100	18,477
Acquired loans portfolio segment | 1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	(184)	(301)	(332)
Acquired loans portfolio segment | 1-4 single family residential | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	27,513	31,476
Allowance for loan losses	(25)	(29)	(26)
Acquired loans portfolio segment | 1-4 single family residential | Non-ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	57,695	66,854
Acquired loans portfolio segment | Construction, land and development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	(36)	(47)	(36)
Acquired loans portfolio segment | Construction, land and development | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	13,167	17,657
Allowance for loan losses	(145)	(239)	(328)
Acquired loans portfolio segment | Construction, land and development | Non-ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	5,889	6,338
Acquired loans portfolio segment | Home equity loans and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	(199)	(243)	(291)
Acquired loans portfolio segment | Home equity loans and lines of credit | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	0	0
Allowance for loan losses	0	0	0
Acquired loans portfolio segment | Home equity loans and lines of credit | Non-ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	34,589	42,295
Acquired loans portfolio segment | Total other loans | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	14,054	16,828
Allowance for loan losses	(271)	(421)
Acquired loans portfolio segment | Total other loans | Non-ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	5,321	6,149
Acquired loans portfolio segment | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	(313)	(376)	(60)
Acquired loans portfolio segment | Commercial and industrial | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	12,631	15,147
Allowance for loan losses	(126)	(277)	(453)
Acquired loans portfolio segment | Commercial and industrial | Non-ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	5,062	5,815
Acquired loans portfolio segment | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	(6)	(6)	(4)
Acquired loans portfolio segment | Consumer | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	1,423	1,681
Allowance for loan losses	(145)	(144)	(406)
Acquired loans portfolio segment | Consumer | Non-ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	259	334
New loans portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	7,661,385	6,259,406
Allowance for loan losses	(42,625)	(33,543)	(23,745)
New loans portfolio segment | Total real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	6,021,029	4,922,169
New loans portfolio segment | Total real estate loans | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	0	0
Allowance for loan losses	0	0
New loans portfolio segment | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	2,103,788	1,438,427
Allowance for loan losses	(12,084)	(7,492)	(5,468)
New loans portfolio segment | Commercial real estate | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	0	0
Allowance for loan losses	0	0
New loans portfolio segment | Owner-occupied commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	987,781	769,814
Allowance for loan losses	(3,310)	(2,536)	(1,780)
New loans portfolio segment | Owner-occupied commercial real estate | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	0	0
Allowance for loan losses	0	0
New loans portfolio segment | 1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	2,185,362	2,012,856
Allowance for loan losses	(7,769)	(7,049)	(6,067)
New loans portfolio segment | 1-4 single family residential | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	0	0
Allowance for loan losses	0	0
New loans portfolio segment | Construction, land and development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	684,462	651,253
Allowance for loan losses	(4,164)	(4,391)	(3,040)
New loans portfolio segment | Construction, land and development | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	0	0
Allowance for loan losses	0	0
New loans portfolio segment | Home equity loans and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	59,636	49,819
Allowance for loan losses	(475)	(405)	(192)
New loans portfolio segment | Home equity loans and lines of credit | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	0	0
Allowance for loan losses	0	0
New loans portfolio segment | Total other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	1,640,356	1,337,237
New loans portfolio segment | Total other loans | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	0	0
Allowance for loan losses	0	0
New loans portfolio segment | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	1,634,372	1,332,869
Allowance for loan losses	(14,702)	(11,592)	(7,152)
New loans portfolio segment | Commercial and industrial | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	0	0
Allowance for loan losses	0	0
New loans portfolio segment | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	5,984	4,368
Allowance for loan losses	(121)	(78)	$ (46)
New loans portfolio segment | Consumer | ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	0	0
Allowance for loan losses	$ 0	$ 0

Loans, Net - Schedule of Loan56

Loans, Net - Schedule of Loans by Portfolio and Segment (Footnote) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
New loans portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net deferred fees, costs, and premium and discount	$ (6.6)	$ 3.2

Loans, Net - Additional Informa

Loans, Net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Pledged loans as collateral for FHLB advances with a carrying amount	$ 3,360,000	$ 3,200,000
Loan amount	7,977,784	6,634,894
Purchase of residential mortgage loans from third parties	22,900	199,000	$ 379,300
Sale of loans to third parties	383,600	128,700	91,800
Change in expected cash flow for certain ASC 310-30 loan pools resulted in the reclassification	(2,300)	(28,700)	$ 43,000
ASC 310-30 Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
UPB of ASC 310-30 loans	183,900	231,500
1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investments of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process	3,200
Other real estate	1,200	1,700
Loan amount	2,270,570	2,111,186
Syndicated national loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount	$ 289,100	$ 433,000

Loans, Net - Summary of Changes

Loans, Net - Summary of Changes in Accretable Discount for ASC 310-30 Loans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at January 1,	$ 60,990	$ 144,152	$ 156,197
Accretion	(17,523)	(54,427)	(55,019)
Reclassifications from non-accretable difference	(2,305)	(28,735)	42,974
Balance at December 31,	$ 41,162	$ 60,990	$ 144,152

Allowance for Loan Losses - Sum

Allowance for Loan Losses - Summary of Changes in Allowance for Loan Losses by Loan Class and Portfolio Segment (Detail) - 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
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				$ 37,897				$ 29,126	$ 37,897	$ 29,126	$ 22,880
Total provision	$ 2,786	$ 2,871	$ 2,115	1,643	$ 2,249	$ 1,990	$ 1,976	1,440	9,415	7,655	6,823
Total charge-offs									(509)	(720)	(1,748)
Total recoveries									342	1,836	1,171
Ending balance	47,145				37,897				47,145	37,897	29,126
Acquired loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				1,410				2,270	1,410	2,270
Total provision									(301)	(1,630)	1,156
Total charge-offs									(109)	(42)	(268)
Total recoveries									131	812	0
Ending balance	1,131				1,410				1,131	1,410	2,270
Acquired loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				2,944				3,111	2,944	3,111
Total provision									(1,150)	(513)	(2,069)
Total charge-offs									(116)	(678)	(1,465)
Total recoveries									211	1,024	1,159
Ending balance	1,889				2,944				1,889	2,944	3,111
New loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				33,543				23,745	33,543	23,745
Total provision									9,366	9,798	7,736
Total charge-offs									(284)	0	(15)
Total recoveries									0	0	12
Ending balance	42,625				33,543				42,625	33,543	23,745
Unallocated financing receivables
Financing Receivable, Allowance for Credit Losses [Line Items]
Total provision		$ 1,500							1,500
Ending balance	1,500								1,500
Unallocated financing receivables | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending balance	0								0
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				10,123				8,450	10,123	8,450	8,206
Total provision									3,876	388	114
Total charge-offs									(170)	(429)	(270)
Total recoveries									41	1,714	400
Ending balance	13,870				10,123				13,870	10,123	8,450
Commercial real estate | Acquired loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				376				1,084	376	1,084
Total provision									(8)	(1,512)	589
Total charge-offs									(30)	0	0
Total recoveries									0	804	0
Ending balance	338				376				338	376	1,084
Commercial real estate | Acquired loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				2,255				1,898	2,255	1,898
Total provision									(839)	(124)	(1,487)
Total charge-offs									(9)	(429)	(270)
Total recoveries									41	910	400
Ending balance	1,448				2,255				1,448	2,255	1,898
Commercial real estate | New loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				7,492				5,468	7,492	5,468
Total provision									4,723	2,024	1,012
Total charge-offs									(131)	0	0
Total recoveries									0	0	0
Ending balance	12,084				7,492				12,084	7,492	5,468
Commercial real estate | New loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				0					0
Ending balance	0				0				0	0
Commercial real estate | Unallocated financing receivables
Financing Receivable, Allowance for Credit Losses [Line Items]
Total provision									0
Ending balance	0								0
Owner-occupied commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				2,597				2,243	2,597	2,243	1,020
Total provision									768	355	1,223
Total charge-offs									0	(1)	0
Total recoveries									0	0	0
Ending balance	3,365				2,597				3,365	2,597	2,243
Owner-occupied commercial real estate | Acquired loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				61				463	61	463
Total provision									(6)	(401)	405
Total charge-offs									0	(1)	0
Total recoveries									0	0	0
Ending balance	55				61				55	61	463
Owner-occupied commercial real estate | Acquired loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				0				0	0	0
Total provision									0	0	0
Total charge-offs									0	0	0
Total recoveries									0	0	0
Ending balance	0				0				0	0	0
Owner-occupied commercial real estate | New loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				2,536				1,780	2,536	1,780
Total provision									774	756	818
Total charge-offs									0	0	0
Total recoveries									0	0	0
Ending balance	3,310				2,536				3,310	2,536	1,780
Owner-occupied commercial real estate | New loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				0					0
Ending balance	0				0				0	0
Owner-occupied commercial real estate | Unallocated financing receivables
Financing Receivable, Allowance for Credit Losses [Line Items]
Total provision									0
Ending balance	0								0
1-4 single family residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				7,379				6,425	7,379	6,425	4,740
Total provision									605	954	2,075
Total charge-offs									(104)	(31)	(564)
Total recoveries									98	31	174
Ending balance	7,978				7,379				7,978	7,379	6,425
1-4 single family residential | Acquired loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				301				332	301	332
Total provision									(146)	(31)	46
Total charge-offs									(69)	0	(128)
Total recoveries									98	0	0
Ending balance	184				301				184	301	332
1-4 single family residential | Acquired loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				29				26	29	26
Total provision									31	3	(37)
Total charge-offs									(35)	(31)	(436)
Total recoveries									0	31	174
Ending balance	25				29				25	29	26
1-4 single family residential | New loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				7,049				6,067	7,049	6,067
Total provision									720	982	2,066
Total charge-offs									0	0	0
Total recoveries									0	0	0
Ending balance	7,769				7,049				7,769	7,049	6,067
1-4 single family residential | New loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				0					0
Ending balance	0				0				0	0
1-4 single family residential | Unallocated financing receivables
Financing Receivable, Allowance for Credit Losses [Line Items]
Total provision									0
Ending balance	0								0
Construction, land and development
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				4,677				3,404	4,677	3,404	2,456
Total provision									(289)	1,234	597
Total charge-offs									(43)	(33)	(56)
Total recoveries									0	72	407
Ending balance	4,345				4,677				4,345	4,677	3,404
Construction, land and development | Acquired loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				47				36	47	36
Total provision									(11)	11	(39)
Total charge-offs									0	0	0
Total recoveries									0	0	0
Ending balance	36				47				36	47	36
Construction, land and development | Acquired loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				239				328	239	328
Total provision									(51)	(128)	(681)
Total charge-offs									(43)	(33)	(56)
Total recoveries									0	72	407
Ending balance	145				239				145	239	328
Construction, land and development | New loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				4,391				3,040	4,391	3,040
Total provision									(227)	1,351	1,317
Total charge-offs									0	0	0
Total recoveries									0	0	0
Ending balance	4,164				4,391				4,164	4,391	3,040
Construction, land and development | New loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				0					0
Ending balance	0				0				0	0
Construction, land and development | Unallocated financing receivables
Financing Receivable, Allowance for Credit Losses [Line Items]
Total provision									0
Ending balance	0								0
Home equity loans and lines of credit
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				648				483	648	483	355
Total provision									36	192	260
Total charge-offs									(10)	(35)	(132)
Total recoveries									0	8	0
Ending balance	674				648				674	648	483
Home equity loans and lines of credit | Acquired loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				243				291	243	291
Total provision									(37)	(21)	138
Total charge-offs									(7)	(35)	(132)
Total recoveries									0	8	0
Ending balance	199				243				199	243	291
Home equity loans and lines of credit | Acquired loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				0				0	0	0
Total provision									0	0	0
Total charge-offs									0	0	0
Total recoveries									0	0	0
Ending balance	0				0				0	0	0
Home equity loans and lines of credit | New loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				405				192	405	192
Total provision									73	213	122
Total charge-offs									(3)	0	0
Total recoveries									0	0	0
Ending balance	475				405				475	405	192
Home equity loans and lines of credit | New loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				0					0
Ending balance	0				0				0	0
Home equity loans and lines of credit | Unallocated financing receivables
Financing Receivable, Allowance for Credit Losses [Line Items]
Total provision									0
Ending balance	0								0
Commercial and industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				12,245				7,665	12,245	7,665	5,745
Total provision									3,004	4,648	2,389
Total charge-offs									(182)	(79)	(658)
Total recoveries									74	11	189
Ending balance	15,141				12,245				15,141	12,245	7,665
Commercial and industrial | Acquired loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				376				60	376	60
Total provision									(64)	316	11
Total charge-offs									(3)	0	0
Total recoveries									4	0	0
Ending balance	313				376				313	376	60
Commercial and industrial | Acquired loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				277				453	277	453
Total provision									(192)	(108)	(39)
Total charge-offs									(29)	(79)	(643)
Total recoveries									70	11	177
Ending balance	126				277				126	277	453
Commercial and industrial | New loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				11,592				7,152	11,592	7,152
Total provision									3,260	4,440	2,417
Total charge-offs									(150)	0	(15)
Total recoveries									0	0	12
Ending balance	14,702				11,592				14,702	11,592	7,152
Commercial and industrial | New loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				0					0
Ending balance	0				0				0	0
Commercial and industrial | Unallocated financing receivables
Financing Receivable, Allowance for Credit Losses [Line Items]
Total provision									0
Ending balance	0								0
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				228				456	228	456	358
Total provision									(85)	(116)	165
Total charge-offs									0	(112)	(68)
Total recoveries									129	0	1
Ending balance	272				228				272	228	456
Consumer | Acquired loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				6				4	6	4
Total provision									(29)	8	6
Total charge-offs									0	(6)	(8)
Total recoveries									29	0	0
Ending balance	6				6				6	6	4
Consumer | Acquired loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				144				406	144	406
Total provision									(99)	(156)	175
Total charge-offs									0	(106)	(60)
Total recoveries									100	0	1
Ending balance	145				144				145	144	406
Consumer | New loans portfolio segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				78				$ 46	78	46
Total provision									43	32	(16)
Total charge-offs									0	0	0
Total recoveries									0	0	0
Ending balance	121				78				121	78	$ 46
Consumer | New loans portfolio segment | ASC 310-30 Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				$ 0					0
Ending balance	0				$ 0				0	$ 0
Consumer | Unallocated financing receivables
Financing Receivable, Allowance for Credit Losses [Line Items]
Total provision									0
Ending balance	$ 0								$ 0

Allowance for Loan Losses - Agi

Allowance for Loan Losses - Aging Analysis of Recorded Investment for Loans by Portfolio and Segment (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	$ 3,293	$ 2,645
Financing receivable, recorded investment, past due	14,246	4,942
New loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	7,326	2,297
New loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	3,627	0
New loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	7,832	12,832
Financing receivable, recorded investment, past due	10,647	13,822
Acquired loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	2,771	820
Acquired loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	44	170
Acquired loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Total real estate loans | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	3,293	2,645
Financing receivable, recorded investment, past due	7,099	4,942
Total real estate loans | New loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	2,346	2,297
Total real estate loans | New loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	1,460	0
Total real estate loans | New loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Total real estate loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	7,438	12,507
Financing receivable, recorded investment, past due	10,152	13,369
Total real estate loans | Acquired loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	2,670	820
Total real estate loans | Acquired loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	44	42
Total real estate loans | Acquired loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Commercial real estate | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	0	581
Financing receivable, recorded investment, past due	324	581
Commercial real estate | New loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	324	0
Commercial real estate | New loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Commercial real estate | New loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Commercial real estate | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	3,893	4,720
Financing receivable, recorded investment, past due	4,253	4,720
Commercial real estate | Acquired loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	360	0
Commercial real estate | Acquired loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Commercial real estate | Acquired loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Owner-occupied commercial real estate | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	0	0
Financing receivable, recorded investment, past due	993	0
Owner-occupied commercial real estate | New loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	843	0
Owner-occupied commercial real estate | New loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	150	0
Owner-occupied commercial real estate | New loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Owner-occupied commercial real estate | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	494	2,502
Financing receivable, recorded investment, past due	784	2,595
Owner-occupied commercial real estate | Acquired loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	290	93
Owner-occupied commercial real estate | Acquired loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Owner-occupied commercial real estate | Acquired loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
1-4 single family residential | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	3,167	1,821
Financing receivable, recorded investment, past due	5,656	3,414
1-4 single family residential | New loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	1,179	1,593
1-4 single family residential | New loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	1,310	0
1-4 single family residential | New loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
1-4 single family residential | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	1,331	2,728
Financing receivable, recorded investment, past due	2,267	2,935
1-4 single family residential | Acquired loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	892	207
1-4 single family residential | Acquired loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	44	0
1-4 single family residential | Acquired loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Construction, land and development | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	0	0
Financing receivable, recorded investment, past due	0	449
Construction, land and development | New loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	449
Construction, land and development | New loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Construction, land and development | New loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Construction, land and development | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	0	0
Financing receivable, recorded investment, past due	0	0
Construction, land and development | Acquired loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Construction, land and development | Acquired loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Construction, land and development | Acquired loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Home equity loans and lines of credit | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	126	243
Financing receivable, recorded investment, past due	126	498
Home equity loans and lines of credit | New loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	255
Home equity loans and lines of credit | New loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Home equity loans and lines of credit | New loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Home equity loans and lines of credit | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	1,720	2,557
Financing receivable, recorded investment, past due	2,848	3,119
Home equity loans and lines of credit | Acquired loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	1,128	520
Home equity loans and lines of credit | Acquired loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	42
Home equity loans and lines of credit | Acquired loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Total other loans | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	0	0
Financing receivable, recorded investment, past due	7,147	0
Total other loans | New loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	4,980	0
Total other loans | New loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	2,167	0
Total other loans | New loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Total other loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	394	325
Financing receivable, recorded investment, past due	495	453
Total other loans | Acquired loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	101	0
Total other loans | Acquired loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	128
Total other loans | Acquired loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Commercial and industrial | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	0	0
Financing receivable, recorded investment, past due	7,147	0
Commercial and industrial | New loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	4,980	0
Commercial and industrial | New loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	2,167	0
Commercial and industrial | New loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Commercial and industrial | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	394	325
Financing receivable, recorded investment, past due	495	453
Commercial and industrial | Acquired loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	101	0
Commercial and industrial | Acquired loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	128
Commercial and industrial | Acquired loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Consumer | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	0	0
Financing receivable, recorded investment, past due	0	0
Consumer | New loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Consumer | New loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Consumer | New loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Consumer | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	0	0
Financing receivable, recorded investment, past due	0	0
Consumer | Acquired loans portfolio segment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Consumer | Acquired loans portfolio segment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Consumer | Acquired loans portfolio segment | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, recorded investment, past due	$ 0	$ 0

Allowance for Loan Losses - S61

Allowance for Loan Losses - Summary of Commercial Non-ASC 310-30 and New Loans by Key Indicators of Credit Quality (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loan amount	$ 7,977,784	$ 6,634,894
New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	7,661,385	6,259,406
Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	316,399	375,488
Pass | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	5,385,265	4,189,395
Pass | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	59,316	63,565
Special Mention | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	22,976	174
Special Mention | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Substandard | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	2,162	2,794
Substandard | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	5,471	5,851
Doubtful | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Doubtful | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loan amount	2,245,859	1,607,841
Commercial real estate | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	2,103,788	1,438,427
Commercial real estate | Pass | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	2,095,560	1,435,633
Commercial real estate | Pass | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	33,496	33,705
Commercial real estate | Special Mention | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	6,066	0
Commercial real estate | Special Mention | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Commercial real estate | Substandard | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	2,162	2,794
Commercial real estate | Substandard | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	4,240	5,081
Commercial real estate | Doubtful | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Commercial real estate | Doubtful | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Owner-occupied commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loan amount	1,003,881	788,291
Owner-occupied commercial real estate | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	987,781	769,814
Owner-occupied commercial real estate | Pass | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	987,781	769,640
Owner-occupied commercial real estate | Pass | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	15,607	18,388
Owner-occupied commercial real estate | Special Mention | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	174
Owner-occupied commercial real estate | Special Mention | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Owner-occupied commercial real estate | Substandard | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Owner-occupied commercial real estate | Substandard | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	493	89
Owner-occupied commercial real estate | Doubtful | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Owner-occupied commercial real estate | Doubtful | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Construction, land and development
Financing Receivable, Recorded Investment [Line Items]
Loan amount	703,518	675,248
Construction, land and development | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	684,462	651,253
Construction, land and development | Pass | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	684,462	651,253
Construction, land and development | Pass | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	5,889	6,338
Construction, land and development | Special Mention | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Construction, land and development | Special Mention | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Construction, land and development | Substandard | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Construction, land and development | Substandard | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Construction, land and development | Doubtful | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Construction, land and development | Doubtful | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Loan amount	1,652,065	1,353,831
Commercial and industrial | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	1,634,372	1,332,869
Commercial and industrial | Pass | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	1,617,462	1,332,869
Commercial and industrial | Pass | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	4,324	5,134
Commercial and industrial | Special Mention | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	16,910	0
Commercial and industrial | Special Mention | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Commercial and industrial | Substandard | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Commercial and industrial | Substandard | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	738	681
Commercial and industrial | Doubtful | New loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	0	0
Commercial and industrial | Doubtful | Acquired loans portfolio segment
Financing Receivable, Recorded Investment [Line Items]
Loan amount	$ 0	$ 0

Allowance for Loan Losses - S62

Allowance for Loan Losses - Summary of Loans Based on Method for Determining Allowance (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	$ 7,977,784	$ 6,634,894
Allowance for credit loss, ASC 310-30 loans	47,145	37,897	$ 29,126	$ 22,880
New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	7,661,385	6,259,406
Allowance for credit loss, ASC 310-30 loans	42,625	33,543	23,745
Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	316,399	375,488
Allowance for credit loss, ASC 310-30 loans	1,131	1,410	2,270
Unallocated financing receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	0
Loans - recorded investment, Collectively evaluated for impairment	7,977,784
Allowance for credit loss, Individually evaluated for impairment	0
Allowance for credit loss, Collectively evaluated for impairment	1,500
Allowance for credit loss, ASC 310-30 loans	1,500
ASC 310-30 Loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	159,069	196,589
Allowance for credit loss, ASC 310-30 loans	1,889	2,944	3,111
ASC 310-30 Loans | Unallocated financing receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	0
Allowance for credit loss, ASC 310-30 loans	0
Total real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	6,318,053	5,274,680
Total real estate loans | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	1,226	1,171
Loans - recorded investment, Collectively evaluated for impairment	6,019,803	4,920,998
Loan amount	6,021,029	4,922,169
Allowance for credit loss, Individually evaluated for impairment	66	287
Allowance for credit loss, Collectively evaluated for impairment	27,736	21,586
Total real estate loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	4,655	7,382
Loans - recorded investment, Collectively evaluated for impairment	147,354	165,368
Allowance for credit loss, Individually evaluated for impairment	129	263
Allowance for credit loss, Collectively evaluated for impairment	683	765
Total real estate loans | ASC 310-30 Loans | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	0	0
Allowance for credit loss, ASC 310-30 loans	0	0
Total real estate loans | ASC 310-30 Loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	145,015	179,761
Allowance for credit loss, ASC 310-30 loans	1,618	2,523
Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	2,245,859	1,607,841
Allowance for credit loss, ASC 310-30 loans	13,870	10,123	8,450	8,206
Commercial real estate | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	0	581
Loans - recorded investment, Collectively evaluated for impairment	2,103,788	1,437,846
Loan amount	2,103,788	1,438,427
Allowance for credit loss, Individually evaluated for impairment	0	221
Allowance for credit loss, Collectively evaluated for impairment	12,084	7,271
Allowance for credit loss, ASC 310-30 loans	12,084	7,492	5,468
Commercial real estate | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	3,893	4,720
Loans - recorded investment, Collectively evaluated for impairment	33,843	34,066
Allowance for credit loss, Individually evaluated for impairment	129	175
Allowance for credit loss, Collectively evaluated for impairment	209	201
Allowance for credit loss, ASC 310-30 loans	338	376	1,084
Commercial real estate | Unallocated financing receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Allowance for credit loss, ASC 310-30 loans	0
Commercial real estate | ASC 310-30 Loans | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	0	0
Allowance for credit loss, ASC 310-30 loans	0	0
Commercial real estate | ASC 310-30 Loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	104,335	130,628
Allowance for credit loss, ASC 310-30 loans	1,448	2,255	1,898
Owner-occupied commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	1,003,881	788,291
Allowance for credit loss, ASC 310-30 loans	3,365	2,597	2,243	1,020
Owner-occupied commercial real estate | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	0	0
Loans - recorded investment, Collectively evaluated for impairment	987,781	769,814
Loan amount	987,781	769,814
Allowance for credit loss, Individually evaluated for impairment	0	0
Allowance for credit loss, Collectively evaluated for impairment	3,310	2,536
Allowance for credit loss, ASC 310-30 loans	3,310	2,536	1,780
Owner-occupied commercial real estate | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	0	0
Loans - recorded investment, Collectively evaluated for impairment	16,100	18,477
Allowance for credit loss, Individually evaluated for impairment	0	0
Allowance for credit loss, Collectively evaluated for impairment	55	61
Allowance for credit loss, ASC 310-30 loans	55	61	463
Owner-occupied commercial real estate | Unallocated financing receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Allowance for credit loss, ASC 310-30 loans	0
Owner-occupied commercial real estate | ASC 310-30 Loans | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	0	0
Allowance for credit loss, ASC 310-30 loans	0	0
Owner-occupied commercial real estate | ASC 310-30 Loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	0	0
Allowance for credit loss, ASC 310-30 loans	0	0	0
1-4 single family residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	2,270,570	2,111,186
Allowance for credit loss, ASC 310-30 loans	7,978	7,379	6,425	4,740
1-4 single family residential | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	1,096	524
Loans - recorded investment, Collectively evaluated for impairment	2,184,266	2,012,332
Loan amount	2,185,362	2,012,856
Allowance for credit loss, Individually evaluated for impairment	0	0
Allowance for credit loss, Collectively evaluated for impairment	7,769	7,049
Allowance for credit loss, ASC 310-30 loans	7,769	7,049	6,067
1-4 single family residential | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	267	1,612
Loans - recorded investment, Collectively evaluated for impairment	57,428	65,242
Allowance for credit loss, Individually evaluated for impairment	0	88
Allowance for credit loss, Collectively evaluated for impairment	184	213
Allowance for credit loss, ASC 310-30 loans	184	301	332
1-4 single family residential | Unallocated financing receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Allowance for credit loss, ASC 310-30 loans	0
1-4 single family residential | ASC 310-30 Loans | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	0	0
Allowance for credit loss, ASC 310-30 loans	0	0
1-4 single family residential | ASC 310-30 Loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	27,513	31,476
Allowance for credit loss, ASC 310-30 loans	25	29	26
Construction, land and development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	703,518	675,248
Allowance for credit loss, ASC 310-30 loans	4,345	4,677	3,404	2,456
Construction, land and development | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	0	0
Loans - recorded investment, Collectively evaluated for impairment	684,462	651,253
Loan amount	684,462	651,253
Allowance for credit loss, Individually evaluated for impairment	0	0
Allowance for credit loss, Collectively evaluated for impairment	4,164	4,391
Allowance for credit loss, ASC 310-30 loans	4,164	4,391	3,040
Construction, land and development | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	0	0
Loans - recorded investment, Collectively evaluated for impairment	5,889	6,338
Allowance for credit loss, Individually evaluated for impairment	0	0
Allowance for credit loss, Collectively evaluated for impairment	36	47
Allowance for credit loss, ASC 310-30 loans	36	47	36
Construction, land and development | Unallocated financing receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Allowance for credit loss, ASC 310-30 loans	0
Construction, land and development | ASC 310-30 Loans | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	0	0
Allowance for credit loss, ASC 310-30 loans	0	0
Construction, land and development | ASC 310-30 Loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	13,167	17,657
Allowance for credit loss, ASC 310-30 loans	145	239	328
Home equity loans and lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	94,225	92,114
Allowance for credit loss, ASC 310-30 loans	674	648	483	355
Home equity loans and lines of credit | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	130	66
Loans - recorded investment, Collectively evaluated for impairment	59,506	49,753
Loan amount	59,636	49,819
Allowance for credit loss, Individually evaluated for impairment	66	66
Allowance for credit loss, Collectively evaluated for impairment	409	339
Allowance for credit loss, ASC 310-30 loans	475	405	192
Home equity loans and lines of credit | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	495	1,050
Loans - recorded investment, Collectively evaluated for impairment	34,094	41,245
Allowance for credit loss, Individually evaluated for impairment	0	0
Allowance for credit loss, Collectively evaluated for impairment	199	243
Allowance for credit loss, ASC 310-30 loans	199	243	291
Home equity loans and lines of credit | Unallocated financing receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Allowance for credit loss, ASC 310-30 loans	0
Home equity loans and lines of credit | ASC 310-30 Loans | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	0	0
Allowance for credit loss, ASC 310-30 loans	0	0
Home equity loans and lines of credit | ASC 310-30 Loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	0	0
Allowance for credit loss, ASC 310-30 loans	0	0	0
Total other loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	1,659,731	1,360,214
Total other loans | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	0	0
Loans - recorded investment, Collectively evaluated for impairment	1,640,356	1,337,237
Loan amount	1,640,356	1,337,237
Allowance for credit loss, Individually evaluated for impairment	0	0
Allowance for credit loss, Collectively evaluated for impairment	14,823	11,670
Total other loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	272	325
Loans - recorded investment, Collectively evaluated for impairment	5,049	5,824
Allowance for credit loss, Individually evaluated for impairment	272	325
Allowance for credit loss, Collectively evaluated for impairment	47	57
Total other loans | ASC 310-30 Loans | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	0	0
Allowance for credit loss, ASC 310-30 loans	0	0
Total other loans | ASC 310-30 Loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	14,054	16,828
Allowance for credit loss, ASC 310-30 loans	271	421
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	1,652,065	1,353,831
Allowance for credit loss, ASC 310-30 loans	15,141	12,245	7,665	5,745
Commercial and industrial | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	0	0
Loans - recorded investment, Collectively evaluated for impairment	1,634,372	1,332,869
Loan amount	1,634,372	1,332,869
Allowance for credit loss, Individually evaluated for impairment	0	0
Allowance for credit loss, Collectively evaluated for impairment	14,702	11,592
Allowance for credit loss, ASC 310-30 loans	14,702	11,592	7,152
Commercial and industrial | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	272	325
Loans - recorded investment, Collectively evaluated for impairment	4,790	5,490
Allowance for credit loss, Individually evaluated for impairment	272	325
Allowance for credit loss, Collectively evaluated for impairment	41	51
Allowance for credit loss, ASC 310-30 loans	313	376	60
Commercial and industrial | Unallocated financing receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Allowance for credit loss, ASC 310-30 loans	0
Commercial and industrial | ASC 310-30 Loans | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	0	0
Allowance for credit loss, ASC 310-30 loans	0	0
Commercial and industrial | ASC 310-30 Loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	12,631	15,147
Allowance for credit loss, ASC 310-30 loans	126	277	453
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	7,666	6,383
Allowance for credit loss, ASC 310-30 loans	272	228	456	$ 358
Consumer | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	0	0
Loans - recorded investment, Collectively evaluated for impairment	5,984	4,368
Loan amount	5,984	4,368
Allowance for credit loss, Individually evaluated for impairment	0	0
Allowance for credit loss, Collectively evaluated for impairment	121	78
Allowance for credit loss, ASC 310-30 loans	121	78	46
Consumer | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans - recorded investment, Individually evaluated for impairment	0	0
Loans - recorded investment, Collectively evaluated for impairment	259	334
Allowance for credit loss, Individually evaluated for impairment	0	0
Allowance for credit loss, Collectively evaluated for impairment	6	6
Allowance for credit loss, ASC 310-30 loans	6	6	4
Consumer | Unallocated financing receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Allowance for credit loss, ASC 310-30 loans	0
Consumer | ASC 310-30 Loans | New loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	0	0
Allowance for credit loss, ASC 310-30 loans	0	0
Consumer | ASC 310-30 Loans | Acquired loans portfolio segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan amount	1,423	1,681
Allowance for credit loss, ASC 310-30 loans	$ 145	$ 144	$ 406

Allowance for Loan Losses - S63

Allowance for Loan Losses - Summary of Impaired Loans Evaluated for Specific Reserves (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Total real estate loans | New loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	$ 66	$ 647
Impaired loans - with allowance, Unpaid principal balance	66	647
Impaired loans - with allowance, Related allowance	66	287
Impaired loans - with no allowance, Recorded investment	1,159	524
Impaired loans - with no allowance, Unpaid principal balance	1,159	524
Total real estate loans | Acquired loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	336	1,195
Impaired loans - with allowance, Unpaid principal balance	347	1,162
Impaired loans - with allowance, Related allowance	129	263
Impaired loans - with no allowance, Recorded investment	4,319	6,187
Impaired loans - with no allowance, Unpaid principal balance	5,753	7,859
Commercial real estate | New loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	0	581
Impaired loans - with allowance, Unpaid principal balance	0	581
Impaired loans - with allowance, Related allowance	0	221
Impaired loans - with no allowance, Recorded investment	0	0
Impaired loans - with no allowance, Unpaid principal balance	0	0
Commercial real estate | Acquired loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	336	630
Impaired loans - with allowance, Unpaid principal balance	347	650
Impaired loans - with allowance, Related allowance	129	175
Impaired loans - with no allowance, Recorded investment	3,557	4,090
Impaired loans - with no allowance, Unpaid principal balance	4,991	5,397
Owner-occupied commercial real estate | New loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	0	0
Impaired loans - with allowance, Unpaid principal balance	0	0
Impaired loans - with allowance, Related allowance	0	0
Impaired loans - with no allowance, Recorded investment	0	0
Impaired loans - with no allowance, Unpaid principal balance	0	0
Owner-occupied commercial real estate | Acquired loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	0	0
Impaired loans - with allowance, Unpaid principal balance	0	0
Impaired loans - with allowance, Related allowance	0	0
Impaired loans - with no allowance, Recorded investment	0	0
Impaired loans - with no allowance, Unpaid principal balance	0	0
1-4 single family residential | New loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	0	0
Impaired loans - with allowance, Unpaid principal balance	0	0
Impaired loans - with allowance, Related allowance	0	0
Impaired loans - with no allowance, Recorded investment	1,096	524
Impaired loans - with no allowance, Unpaid principal balance	1,096	524
1-4 single family residential | Acquired loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	0	565
Impaired loans - with allowance, Unpaid principal balance	0	512
Impaired loans - with allowance, Related allowance	0	88
Impaired loans - with no allowance, Recorded investment	267	1,047
Impaired loans - with no allowance, Unpaid principal balance	267	1,047
Construction, land and development | New loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	0	0
Impaired loans - with allowance, Unpaid principal balance	0	0
Impaired loans - with allowance, Related allowance	0	0
Impaired loans - with no allowance, Recorded investment	0	0
Impaired loans - with no allowance, Unpaid principal balance	0	0
Construction, land and development | Acquired loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	0	0
Impaired loans - with allowance, Unpaid principal balance	0	0
Impaired loans - with allowance, Related allowance	0	0
Impaired loans - with no allowance, Recorded investment	0	0
Impaired loans - with no allowance, Unpaid principal balance	0	0
Home equity loans and lines of credit | New loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	66	66
Impaired loans - with allowance, Unpaid principal balance	66	66
Impaired loans - with allowance, Related allowance	66	66
Impaired loans - with no allowance, Recorded investment	63	0
Impaired loans - with no allowance, Unpaid principal balance	63	0
Home equity loans and lines of credit | Acquired loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	0	0
Impaired loans - with allowance, Unpaid principal balance	0	0
Impaired loans - with allowance, Related allowance	0	0
Impaired loans - with no allowance, Recorded investment	495	1,050
Impaired loans - with no allowance, Unpaid principal balance	495	1,415
Total other loans | New loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	0	0
Impaired loans - with allowance, Unpaid principal balance	0	0
Impaired loans - with allowance, Related allowance	0	0
Impaired loans - with no allowance, Recorded investment	0	0
Impaired loans - with no allowance, Unpaid principal balance	0	0
Total other loans | Acquired loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	272	325
Impaired loans - with allowance, Unpaid principal balance	272	325
Impaired loans - with allowance, Related allowance	272	325
Impaired loans - with no allowance, Recorded investment	0	0
Impaired loans - with no allowance, Unpaid principal balance	0	0
Commercial and industrial | New loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	0	0
Impaired loans - with allowance, Unpaid principal balance	0	0
Impaired loans - with allowance, Related allowance	0	0
Impaired loans - with no allowance, Recorded investment	0	0
Impaired loans - with no allowance, Unpaid principal balance	0	0
Commercial and industrial | Acquired loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	272	325
Impaired loans - with allowance, Unpaid principal balance	272	325
Impaired loans - with allowance, Related allowance	272	325
Impaired loans - with no allowance, Recorded investment	0	0
Impaired loans - with no allowance, Unpaid principal balance	0	0
Consumer | New loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	0	0
Impaired loans - with allowance, Unpaid principal balance	0	0
Impaired loans - with allowance, Related allowance	0	0
Impaired loans - with no allowance, Recorded investment	0	0
Impaired loans - with no allowance, Unpaid principal balance	0	0
Consumer | Acquired loans portfolio segment
Financing Receivable, Impaired [Line Items]
Impaired loans - with allowance, Recorded investment	0	0
Impaired loans - with allowance, Unpaid principal balance	0	0
Impaired loans - with allowance, Related allowance	0	0
Impaired loans - with no allowance, Recorded investment	0	0
Impaired loans - with no allowance, Unpaid principal balance	$ 0	$ 0

Allowance for Loan Losses - S64

Allowance for Loan Losses - Summary of Impaired Loans Average Recorded Investment and Interest Income Recognized (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Total real estate loans
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance - Average recorded investment	$ 5,686	$ 6,333
Impaired loans with no related allowance - Interest income recognized	0	0
Impaired loans with an allowance - Average recorded investment	546	1,427
Impaired loans with an allowance - Interest income recognized	0	0
Commercial real estate
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance - Average recorded investment	3,653	4,245
Impaired loans with no related allowance - Interest income recognized	0	0
Impaired loans with an allowance - Average recorded investment	480	959
Impaired loans with an allowance - Interest income recognized	0	0
Owner-occupied commercial real estate
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance - Average recorded investment	0	0
Impaired loans with no related allowance - Interest income recognized	0	0
Impaired loans with an allowance - Average recorded investment	0	0
Impaired loans with an allowance - Interest income recognized	0	0
1-4 single family residential
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance - Average recorded investment	1,363	816
Impaired loans with no related allowance - Interest income recognized	0	0
Impaired loans with an allowance - Average recorded investment	0	424
Impaired loans with an allowance - Interest income recognized	0	0
Construction, land and development
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance - Average recorded investment	0	0
Impaired loans with no related allowance - Interest income recognized	0	0
Impaired loans with an allowance - Average recorded investment	0	0
Impaired loans with an allowance - Interest income recognized	0	0
Home equity loans and lines of credit
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance - Average recorded investment	670	1,272
Impaired loans with no related allowance - Interest income recognized	0	0
Impaired loans with an allowance - Average recorded investment	66	44
Impaired loans with an allowance - Interest income recognized	0	0
Total other loans
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance - Average recorded investment	0	0
Impaired loans with no related allowance - Interest income recognized	0	0
Impaired loans with an allowance - Average recorded investment	317	170
Impaired loans with an allowance - Interest income recognized	0	0
Commercial and industrial
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance - Average recorded investment	0	0
Impaired loans with no related allowance - Interest income recognized	0	0
Impaired loans with an allowance - Average recorded investment	317	170
Impaired loans with an allowance - Interest income recognized	0	0
Consumer
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance - Average recorded investment	0	0
Impaired loans with no related allowance - Interest income recognized	0	0
Impaired loans with an allowance - Average recorded investment	0	0
Impaired loans with an allowance - Interest income recognized	$ 0	$ 0

Covered Assets and Loss Shari65

Covered Assets and Loss Sharing Agreements - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 04, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Banking and Thrift [Abstract]
Consideration paid	$ 14,800	$ 0	$ 0	$ 14,815
Loss on termination of agreement with FDIC	$ 65,500

Covered Assets and Loss Shari66

Covered Assets and Loss Sharing Agreements - Summary of Changes in Loss Share Indemnification Asset (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
FDIC Indemnification Asset [Roll Forward]
Balance at beginning of period	$ 0	$ 0	$ 63,168
Termination of FDIC loss sharing agreements	0	0	(63,168)
Balance at end of period	$ 0	$ 0	$ 0

Covered Assets and Loss Shari67

Covered Assets and Loss Sharing Agreements - Summary of Changes in Clawback Liability included Other Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Liabilities Disclosure [Abstract]
Balance at beginning of period	$ 0	$ 0	$ 13,846
Termination of FDIC loss sharing agreements	0	0	(13,846)
Balance at end of period	$ 0	$ 0	$ 0

Premises and Equipment - Compon

Premises and Equipment - Components of Premises and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment, Net [Abstract]
Land	$ 7,624	$ 7,624
Building and improvements	24,653	24,653
Furniture, fixtures and equipment	14,956	13,197
Leasehold improvements	5,164	4,454
Construction in Process	663	525
Software	3,354	3,021
Total	56,414	53,474
Less: Accumulated depreciation	(20,270)	(16,822)
Total premises and equipment, net	$ 36,144	$ 36,652

Premises and Equipment - Additi

Premises and Equipment - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment, Net [Abstract]
Depreciation expense	$ 3.6	$ 3.6	$ 3.8
Rental expense	$ 7.6	$ 7.6	$ 7.5

Premises and Equipment - Schedu

Premises and Equipment - Schedule of Future Minimum Rental Payments Under Non-Cancellable Operating Leases (Details) $ in Thousands	Dec. 31, 2017USD ($)
Property, Plant and Equipment [Abstract]
2,018	$ 5,205
2,019	4,707
2,020	4,438
2,021	3,145
2,022	2,398
Thereafter	12,431
Total	$ 32,324

Goodwill and Intangibles - Summ

Goodwill and Intangibles - Summary of Goodwill and Other Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 81,204	$ 81,204
Core deposit intangible	14,370	14,370
Less: Accumulated amortization	(10,702)	(9,679)
Net core deposit intangible	$ 3,668	$ 4,691

Goodwill and Intangibles - Addi

Goodwill and Intangibles - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 1,023	$ 1,189	$ 1,631

Goodwill and Intangibles - Esti

Goodwill and Intangibles - Estimated Amortization Expense for Core Deposit Intangible Assets to be Recognized (Detail) - Core deposit intangible $ in Thousands	Dec. 31, 2017USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Expected amortization expense in 2018	$ 1,023
Expected amortization expense in 2019	1,023
Expected amortization expense in 2020	510
Expected amortization expense in 2021	360
Expected amortization expense in 2022	$ 360

Derivatives - Additional Inform

Derivatives - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Instruments	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Derivative [Line Items]
Number of derivative instruments held | Instruments	2
Carrying value of pledged securities	$ 834,900	$ 594,000
Swap
Derivative [Line Items]
Customer swap fees in non-interest income in the accompanying consolidated statements of operations	6,800	4,400	$ 5,200
Interest rate swap
Derivative [Line Items]
Carrying value of pledged securities	25,700
Not designated as hedging instrument
Derivative [Line Items]
Derivative assets, notional	1,233,004	$ 891,274
Not designated as hedging instrument | Risk Participation Agreement
Derivative [Line Items]
Derivative assets, notional	$ 32,500

Derivatives - Summary of Deriva

Derivatives - Summary of Derivatives Outstanding Included in Other Assets and Liabilities (Detail) - Not designated as hedging instrument - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative assets, notional	$ 1,233,004	$ 891,274
Derivative assets, fair value	11,833	15,268
Derivative liabilities, notional	1,233,004	891,274
Derivative liabilities, fair value	11,833	15,268
Interest rate swaps—pay floating, receive fixed
Derivatives, Fair Value [Line Items]
Derivative assets, notional	757,887	708,426
Derivative assets, fair value	11,678	15,268
Derivative liabilities, notional	380,233	182,848
Derivative liabilities, fair value	4,180	2,908
Interest rate swaps—pay fixed, receive floating
Derivatives, Fair Value [Line Items]
Derivative assets, notional	380,233	182,848
Derivative assets, fair value	0	0
Derivative liabilities, notional	757,887	708,426
Derivative liabilities, fair value	7,498	$ 12,360
Interest rate caps—purchased
Derivatives, Fair Value [Line Items]
Derivative assets, notional	94,884
Derivative assets, fair value	155
Derivative liabilities, notional	0
Derivative liabilities, fair value	0
Interest rate caps—sold
Derivatives, Fair Value [Line Items]
Derivative assets, notional	0
Derivative assets, fair value	0
Derivative liabilities, notional	94,884
Derivative liabilities, fair value	$ 155

Derivatives - Summary of Gross

Derivatives - Summary of Gross and Net Fair Values of Derivatives Outstanding Included in Other Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	$ 11,833	$ 15,268
Gross amounts offset in the consolidated balance sheets	(4,491)	(2,908)
Net amounts in the consolidated balance sheets	7,342	12,360
Interest rate swap | Counterparty A—Interest rate contracts
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	11,833	15,268
Gross amounts offset in the consolidated balance sheets	(4,491)	(2,908)
Net amounts in the consolidated balance sheets	$ 7,342	$ 12,360

Deposits - Summary of Company's

Deposits - Summary of Company's Deposits by Category (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Banking and Thrift [Abstract]
Noninterest-bearing demand deposits	$ 1,236,685	$ 905,905
Interest-bearing demand deposits	1,454,097	1,004,452
Interest-bearing NOW accounts	363,191	398,823
Savings and money market accounts	3,013,237	2,780,697
Time deposits	2,606,717	2,215,794
Total deposits	8,673,927	7,305,671
Time deposits $100,000 and greater	1,983,445	1,675,162
Time deposits greater than $250,000	$ 1,078,702	$ 843,683

Deposits - Additional Informati

Deposits - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Banking and Thrift [Abstract]
Aggregate amount of overdraft demand deposits reclassified to loans	$ 1.1
Aggregate amount of time deposits, Year one	1,590
Aggregate amount of time deposits, Year two	983
Aggregate amount of time deposits, Year three	21.7
Aggregate amount of time deposits, Year four	7.3
Aggregate amount of time deposits, Year five	6.6
Brokered deposits through an insured deposits sweep program	656.4	$ 693.9
Brokered certificates of deposit	$ 85.2	$ 1.2

FHLB and Other Borrowings - FHL

FHLB and Other Borrowings - FHLB Advances and Other Borrowings Outstanding (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal home loan bank, advances, maturities summary, due in next 12 months	$ 270,000	$ 342,250
Federal home loan bank, advances, maturities summary, due in year 2	0	50,000
Federal home loan bank, advances, maturities summary, due in year 3	400,000	200,000
Total FHLB advances	670,000	592,250
Securities sold under repurchase agreements	50,336	131,621
Retail repurchase agreements	28,777	26,386
Total contractual outstanding	749,113	750,257
Fair value adjustment	0	846
Total Borrowings	$ 749,113	$ 751,103
2,019
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Range of contractual interest rate at period end	0.00%	1.53%
Maximum | 2018
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Range of contractual interest rate at period end	1.59%	0.80%
Maximum | 2020 and beyond
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Range of contractual interest rate at period end	2.28%	1.61%
Minimum | 2018
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Range of contractual interest rate at period end	1.41%	0.62%
Minimum | 2020 and beyond
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Range of contractual interest rate at period end	1.34%	1.34%
Securities agreements | Maximum
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Range of contractual interest rate at period end	2.41%	4.35%
Securities agreements | Minimum
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Range of contractual interest rate at period end	1.87%	1.40%
Retail agreements
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Range of contractual interest rate at period end	0.25%	0.25%

FHLB and Other Borrowings - Add

FHLB and Other Borrowings - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Additional capacity to borrow from FHLB	$ 1,400,000,000
Unused credit lines with financial institutions	540,000,000
Federal home loan bank advances
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Interest expense on FHLB advances	11,600,000	$ 5,800,000	$ 4,000,000
Weighted average
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Advances with FHLB	$ 798,400,000	$ 612,100,000
Weighted-average interest rates on FHLB	1.45%	0.94%

Regulatory Capital - Regulatory

Regulatory Capital - Regulatory Capital Levels (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Company
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage ratio, actual amount	$ 1,079,851	$ 891,584
Tier 1 leverage ratio, actual ratio	10.50%	10.30%
Tier 1 leverage ratio, minimum capital requirement, amount	$ 411,177	$ 346,518
Tier 1 leverage ratio, minimum capital requirement, ratio	4.00%	4.00%
Tier 1 leverage ratio, minimum to be well capitalized, amount	$ 513,972	$ 433,148
Tier 1 leverage ratio, minimum to be well capitalized, ratio	5.00%	5.00%
Common equity tier 1 capital ratio, actual amount	$ 1,079,851	$ 891,584
Common equity tier 1 capital ratio, actual ratio	11.90%	11.90%
Common equity tier 1 capital ratio, minimum capital requirement amount	$ 409,482	$ 336,328
Common equity tier 1 capital ratio, minimum capital requirement ratio	4.50%	4.50%
Common equity tier 1 capital ratio, minimum to be well capitalized amount	$ 591,475	$ 485,807
Common equity tier 1 capital ratio, minimum to be well capitalized ratio	6.50%	6.50%
Tier 1 risk-based capital ratio, actual amount	$ 1,079,851	$ 891,584
Tier 1 risk-based capital ratio, actual ratio	11.90%	11.90%
Tier 1 risk-based capital ratio, minimum capital requirement, amount	$ 545,977	$ 448,437
Tier 1 risk-based capital ratio, minimum capital requirement, ratio	6.00%	6.00%
Tier 1 risk-based capital ratio, minimum to be well capitalized, amount	$ 727,969	$ 597,916
Tier 1 risk-based capital ratio, minimum to be well capitalized, ratio	8.00%	8.00%
Total risk-based capital ratio, actual amount	$ 1,128,889	$ 930,821
Total risk-based capital ratio, actual ratio	12.40%	12.50%
Total risk-based capital ratio, minimum capital requirement, amount	$ 727,969	$ 597,916
Total risk-based capital ratio, minimum capital requirement, ratio	8.00%	8.00%
Total risk-based capital ratio, minimum to be Well capitalized, amount	$ 909,961	$ 747,395
Total risk-based capital ratio, minimum to be well capitalized, ratio	10.00%	10.00%
Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage ratio, actual amount	$ 927,426	$ 795,207
Tier 1 leverage ratio, actual ratio	9.20%	9.30%
Tier 1 leverage ratio, minimum capital requirement, amount	$ 403,527	$ 340,856
Tier 1 leverage ratio, minimum capital requirement, ratio	4.00%	4.00%
Tier 1 leverage ratio, minimum to be well capitalized, amount	$ 504,409	$ 426,070
Tier 1 leverage ratio, minimum to be well capitalized, ratio	5.00%	5.00%
Common equity tier 1 capital ratio, actual amount	$ 927,426	$ 795,207
Common equity tier 1 capital ratio, actual ratio	10.40%	10.90%
Common equity tier 1 capital ratio, minimum capital requirement amount	$ 400,187	$ 329,194
Common equity tier 1 capital ratio, minimum capital requirement ratio	4.50%	4.50%
Common equity tier 1 capital ratio, minimum to be well capitalized amount	$ 578,047	$ 475,503
Common equity tier 1 capital ratio, minimum to be well capitalized ratio	6.50%	6.50%
Tier 1 risk-based capital ratio, actual amount	$ 927,426	$ 795,207
Tier 1 risk-based capital ratio, actual ratio	10.40%	10.90%
Tier 1 risk-based capital ratio, minimum capital requirement, amount	$ 533,582	$ 438,926
Tier 1 risk-based capital ratio, minimum capital requirement, ratio	6.00%	6.00%
Tier 1 risk-based capital ratio, minimum to be well capitalized, amount	$ 711,443	$ 585,234
Tier 1 risk-based capital ratio, minimum to be well capitalized, ratio	8.00%	8.00%
Total risk-based capital ratio, actual amount	$ 975,663	$ 834,679
Total risk-based capital ratio, actual ratio	11.00%	11.40%
Total risk-based capital ratio, minimum capital requirement, amount	$ 711,443	$ 585,234
Total risk-based capital ratio, minimum capital requirement, ratio	8.00%	8.00%
Total risk-based capital ratio, minimum to be Well capitalized, amount	$ 889,304	$ 731,543
Total risk-based capital ratio, minimum to be well capitalized, ratio	10.00%	10.00%

Regulatory Capital - Additional

Regulatory Capital - Additional Information (Detail) - FDIC order	12 Months Ended
	Dec. 31, 2017
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Ratio of Tier 1 common equity to total assets	10.00%
Minimum period required to maintain Tier 1 common equity to total assets ratio	3 years

Accumulated Other Comprehensi83

Accumulated Other Comprehensive Income - Schedule of Changes in Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Changes In Accumulated Other Comprehensive Income [Abstract]
Balance at beginning of period	$ (6,504)	$ (15,371)	$ 1,106
Balance at beginning of period, tax effect	2,509	5,928	(427)
Balance at beginning of period, net of tax	(3,995)	(9,443)	679
Balance at end of period	14,402	(6,504)	(15,371)
Balance at end of period, tax effect	(5,509)	2,509	5,928
Balance at end of period, net of tax	8,893	(3,995)	(9,443)
Unrealized Gain (Loss) on Investment Securities Available for Sale
Changes In Accumulated Other Comprehensive Income [Abstract]
Net unrealized holdings gain (loss) arising during the period	24,112	11,582	(13,997)
Net unrealized holdings gain (loss) arising during the period, tax effect	(9,244)	(4,467)	5,399
Net unrealized holdings gain (loss) arising during the period, net of tax	14,868	7,115	(8,598)
Amounts reclassified to (gain) loss on investment securities	(3,206)	(2,715)	(2,480)
Amounts reclassified to (gain) loss on investment securities, tax effect	1,226	1,048	956
Amounts reclassified to (gain) loss on investment securities, net of tax	$ (1,980)	$ (1,667)	$ (1,524)

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)Class_of_Stock$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)
Capital Unit [Line Items]
Number of classes of common stock | Class_of_Stock	2
Increase (decrease) in shares issued and outstanding due to conversion	188,474	3,545,408
Common stock exchange ratio	100.00%
Consideration paid or received on conversion of stock | $	$ 0
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Preferred stock, par value (in dollars per share) | $ / shares	$ 0.001	$ 0.001
Treasury stock, value acquired, cost | $		$ 23,738,000	$ 34,884,000
Treasury stock, shares (in shares)		2,886,621
Treasury stock, value | $	$ 77,373,000	$ 77,373,000
2009 Warrants
Capital Unit [Line Items]
Warrants outstanding (in shares)	1,274,022
Stock-based compensation expense | $	$ 0
Class A common stock
Capital Unit [Line Items]
Treasury stock, shares repurchased (in shares)	0	(717,115)
Treasury stock, per share (in dollars per share) | $ / shares		$ 33.08
Treasury stock, value acquired, cost | $		$ 23,700,000
Treasury stock, shares (in shares)	2,694,489	2,694,489
Class B common stock
Capital Unit [Line Items]
Increase (decrease) in shares issued and outstanding due to conversion	(188,474)	3,545,408
Treasury stock, shares (in shares)	192,132	192,132

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Activity of Warrants (Detail) - 2009 Warrants $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, beginning balance (in shares) | shares	2,685,927
Warrants, granted (in shares) | shares	0
Warrants, exercised (in shares) | shares	(1,411,905)
Warrants, forfeited (in shares) | shares	0
Warrants, expired (in shares) | shares	0
Options outstanding, ending balance (in shares) | shares	1,274,022
Warrants, exercisable (in shares) | shares	1,274,022
Warrants, vested (in shares) | shares	1,274,022
Warrants, vested and expected to vest | shares	1,274,022
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Options outstanding, beginning balance, weighted average exercise price (in dollars per share) | $ / shares	$ 26.48
Weighted average exercise price, granted (in dollars per share) | $ / shares	0
Weighted average exercise price, exercised (in dollars per share) | $ / shares	26.24
Weighted average exercise price, forfeited (in dollars per share) | $ / shares	0
Weighted average exercise price, expired (in dollars per share) | $ / shares	0
Options outstanding, ending balance, weighted average exercise price (in dollars per share) | $ / shares	26.75
Weighted average exercise price, exercisable (in dollars per share) | $ / shares	26.75
Weighted average exercise price, vested | $ / shares	26.75
Weighted average exercise price, vested and expected to vest | $ / shares	$ 26.75
Aggregate intrinsic value, exercised | $	$ 31,895
Aggregate intrinsic value, outstanding | $	30,640
Aggregate intrinsic value, exercisable | $	30,640
Aggregate intrinsic value, vested | $	30,640
Aggregate intrinsic value, vested and expected to vest | $	$ 30,640
Weighted average remaining contractual life (years), outstanding	1 year 10 months 14 days
Weighted average remaining contractual life (years), exercisable	1 year 10 months 14 days
Weighted average remaining contractual life (years), vested	1 year 10 months 14 days
Weighted average remaining contractual life (years), vested and expected to vest	1 year 10 months 14 days

Stock-Based Compensation and 86

Stock-Based Compensation and Other Benefit Plans - 2009 Equity Incentive Plan - Additional Information (Detail) - Stock Options - 2009 Equity Incentive Plan	12 Months Ended
	Dec. 31, 2009shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate percent of common stock that may be granted under the plan	10.00%
Aggregate shares of common stock that may be granted under the plan	4,375,000

Stock-Based Compensation and 87

Stock-Based Compensation and Other Benefit Plans - Schedule of Option Activity (Detail) - Stock Options - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
2009 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, beginning balance (in shares)		3,107,235
Granted, options (in shares)		0
Exercised, options (in shares)		(1,768,652)
Forfeited, options (in shares)		(21,322)
Expired, options (in shares)		(2,337)
Options outstanding, ending balance (in shares)		1,314,924	3,107,235
Exercisable, options (in shares)		1,314,924
Vested, options (in shares)		1,314,924
Vested and expected to vest, options (in shares)		1,314,924
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price [Abstract]
Options outstanding, beginning balance, weighted average exercise price (in dollars per share)		$ 20.62
Options granted, weighted average exercise price (in dollars per share)		0
Options exercised, weighted average exercise price (in dollars per share)		20.58
Options forfeited, weighted average exercise price (in dollars per share)		22.72
Options expired, weighted average exercise price (in dollars per share)		22.97
Options outstanding, ending balance, weighted average exercise price (in dollars per share)		20.65	$ 20.62
Exercisable, weighted average exercise price (in dollars per share)		20.65
Vested, weighted average exercise price (in dollars per share)		20.65
Vested and expected to vest, weighted average exercise price (in dollars per share)		$ 20.65
Exercised, aggregate intrinsic value		$ 47,180	$ 9,547	$ 4,940
Options outstanding, aggregate intrinsic value		39,651
Exercisable, aggregate intrinsic value		39,651
Vested, aggregate intrinsic value		39,651
Vested and expected to vest, aggregate intrinsic value		$ 39,651
Options outstanding, weighted average remaining contractual term		4 years 5 months 27 days
Exercisable, weighted average remaining contractual term		4 years 5 months 27 days
Vested, weighted average remaining contractual term		4 years 5 months 27 days
Vested and expected to vest, weighted average remaining contractual term		4 years 5 months 27 days
2013 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, beginning balance (in shares)		2,164,258
Granted, options (in shares)		0
Exercised, options (in shares)		(725,970)
Forfeited, options (in shares)		(13,335)
Expired, options (in shares)		0
Options outstanding, ending balance (in shares)		1,424,953	2,164,258
Exercisable, options (in shares)		1,408,115
Vested, options (in shares)		1,408,115
Vested and expected to vest, options (in shares)		1,424,953
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price [Abstract]
Options outstanding, beginning balance, weighted average exercise price (in dollars per share)		$ 20.63
Options granted, weighted average exercise price (in dollars per share)		0
Options exercised, weighted average exercise price (in dollars per share)		20.18
Options forfeited, weighted average exercise price (in dollars per share)		27.23
Options expired, weighted average exercise price (in dollars per share)		0
Options outstanding, ending balance, weighted average exercise price (in dollars per share)		20.79	$ 20.63
Exercisable, weighted average exercise price (in dollars per share)		20.71
Vested, weighted average exercise price (in dollars per share)		20.71
Vested and expected to vest, weighted average exercise price (in dollars per share)		$ 20.79
Exercised, aggregate intrinsic value		$ 20,633	$ 3,888	$ 465
Options outstanding, aggregate intrinsic value		42,764
Exercisable, aggregate intrinsic value		42,372
Vested, aggregate intrinsic value		42,372
Vested and expected to vest, aggregate intrinsic value		$ 42,764
Options outstanding, weighted average remaining contractual term		6 years 2 months 16 days
Exercisable, weighted average remaining contractual term		6 years 2 months 13 days
Vested, weighted average remaining contractual term		6 years 2 months 13 days
Vested and expected to vest, weighted average remaining contractual term		6 years 2 months 16 days
2016 Stock Incentive Plan - Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, beginning balance (in shares)		827,500
Granted, options (in shares)	827,500	37,500
Exercised, options (in shares)		0
Forfeited, options (in shares)		(102,500)
Expired, options (in shares)		0
Options outstanding, ending balance (in shares)		762,500	827,500
Exercisable, options (in shares)		0
Vested, options (in shares)		0
Vested and expected to vest, options (in shares)		762,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price [Abstract]
Options outstanding, beginning balance, weighted average exercise price (in dollars per share)		$ 36.11
Options granted, weighted average exercise price (in dollars per share)	$ 36.11	46.89
Options exercised, weighted average exercise price (in dollars per share)		0
Options forfeited, weighted average exercise price (in dollars per share)		36.11
Options expired, weighted average exercise price (in dollars per share)		0
Options outstanding, ending balance, weighted average exercise price (in dollars per share)		36.64	$ 36.11
Exercisable, weighted average exercise price (in dollars per share)		0
Vested, weighted average exercise price (in dollars per share)		0
Vested and expected to vest, weighted average exercise price (in dollars per share)		$ 36.64
Exercised, aggregate intrinsic value		$ 0
Options outstanding, aggregate intrinsic value		10,797
Exercisable, aggregate intrinsic value		0
Vested, aggregate intrinsic value		0
Vested and expected to vest, aggregate intrinsic value		$ 10,797
Options outstanding, weighted average remaining contractual term		8 years 7 months 21 days
Vested and expected to vest, weighted average remaining contractual term		8 years 7 months 21 days

Stock-Based Compensation and 88

Stock-Based Compensation and Other Benefit Plans - Summary of Stock-based Compensation Expense (Detail) - USD ($) $ 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]
Amount of cash received from exercise of awards	$ 50,670	$ 17,042	$ 8,793
2009 Equity Incentive Plan | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	760	1,707	2,239
Tax benefit realized from stock awards exercised	19,070	3,622	1,618
Fair value of stock-based awards that vested during the year	1,075	1,882	2,724
Amount of cash received from exercise of awards	36,392	11,427	8,163
Total intrinsic value of awards exercised during the year	47,180	9,547	4,940
Unrecognized compensation expense related to stock-based compensation	$ 0	$ 569	$ 2,561
Weighted-average life over which expense is expected to be recognized (years)	0 years	9 months 10 days	1 year 8 months 19 days
2013 Stock Incentive Plan | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 226	$ 1,655	$ 2,002
Tax benefit realized from stock awards exercised	8,019	1,380	158
Fair value of stock-based awards that vested during the year	3,732	4,313	1,181
Amount of cash received from exercise of awards	14,652	5,186	714
Total intrinsic value of awards exercised during the year	20,633	3,888	465
Unrecognized compensation expense related to stock-based compensation	$ 41	$ 333	$ 1,633
Weighted-average life over which expense is expected to be recognized (years)	3 months 11 days	1 year 2 months 26 days	1 year 6 months 11 days
2016 Stock Incentive Plan - Stock Options | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,431	$ 570
Total intrinsic value of awards exercised during the year	0
Unrecognized compensation expense related to stock-based compensation	$ 4,882	$ 6,563
Weighted-average life over which expense is expected to be recognized (years)	3 years 7 months 28 days	4 years 7 months 9 days
2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards | Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 3,672	$ 1,393
Unrecognized compensation expense related to stock-based compensation	$ 3,113	$ 2,785
Weighted-average life over which expense is expected to be recognized (years)	1 year 3 months 22 days	2 years
2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards | Restricted Stock Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,225	$ 0
Unrecognized compensation expense related to stock-based compensation	$ 4,051	$ 0
Weighted-average life over which expense is expected to be recognized (years)	4 years 10 months 17 days	0 years
2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards | Performance Restricted Stock Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 968	$ 0
Unrecognized compensation expense related to stock-based compensation	$ 2,532	$ 0
Weighted-average life over which expense is expected to be recognized (years)	2 years	0 years

Stock-Based Compensation and 89

Stock-Based Compensation and Other Benefit Plans - 2013 Stock Incentive Plan - Additional Information (Detail) - 2013 Stock Incentive Plan - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate shares of common stock that may be granted under the plan (in shares)			3,000,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)	0
Options granted, weighted average exercise price (in dollars per share)	$ 0
Stock Options | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)		120,500
Options vesting period		3 years
Options granted, weighted average exercise price (in dollars per share)		$ 27.36
Stock based compensation awards, aggregate fair value on grant date		$ 960
Stock based compensation awards, expiration period		10 years
Stock Options | Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)		129,000
Options granted, weighted average exercise price (in dollars per share)		$ 23.97
Stock based compensation awards, expiration period		10 years
Stock based compensation awards, shares vesting percentage		25.00%
Stock based compensation awards, aggregate fair value on grant date		$ 881
Maximum | Restricted stock, restricted stock units, and unrestricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate shares of common stock that may be granted under the plan (in shares)			500,000

Stock-Based Compensation and 90

Stock-Based Compensation and Other Benefit Plans - Schedule of Assumptions used for Estimating Fair Values of Option Plan Awards (Detail) - Stock Options - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
2013 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	0.00%	24.70%	31.10%
Expected dividend yield	0.00%	1.25%	1.25%
Expected term (years)	0 years	6 years	6 years 2 months 12 days
Risk-free interest rate	0.00%	1.37%	1.63%
Weighted average grant date fair value	$ 0	$ 6.57	$ 7.38
2016 Stock Incentive Plan - Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility		24.00%
Expected dividend yield	1.25%	1.25%
Expected term (years)	7 years 6 months	7 years 6 months
Risk-free interest rate		1.42%
Weighted average grant date fair value	$ 11.73	$ 8.62
2016 Stock Incentive Plan - Stock Options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	22.60%
Risk-free interest rate	2.04%
2016 Stock Incentive Plan - Stock Options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	23.40%
Risk-free interest rate	2.17%

Stock-Based Compensation and 91

Stock-Based Compensation and Other Benefit Plans Stock-Based Compensation and Other Benefit Plans - 2016 Stock Incentive Plan - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Mar. 28, 2017	Feb. 07, 2017	Mar. 29, 2016	Aug. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
2016 Stock Incentive Plan - Stock Options | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, options (in shares)				827,500	37,500
Options vesting period				5 years	5 years
Options granted, weighted average exercise price (in dollars per share)				$ 36.11	$ 46.89
Stock based compensation awards, aggregate fair value on grant date				$ 7,100	$ 440
Stock based compensation awards, expiration period				10 years	10 years
Stock-based compensation expense					$ 1,431	$ 570
2016 Stock Incentive Plan - Stock Options | Stock Options | Class A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)					2,000,000
2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards | Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation grant date fair value			$ 4,200
Stock-based compensation expense					$ 3,672	1,393
2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards | Restricted Stock Awards | Class A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)			121,000
2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards | Restricted Stock Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense					1,225	0
2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards | Performance Restricted Stock Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense					$ 968	$ 0
Executive Officer | 2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards | Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	84,000
Share-based compensation grant date fair value	$ 4,000
Director | 2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards | Restricted Stock Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)		25,000
Share-based compensation grant date fair value		$ 1,100
Stock based compensation awards, shares vesting percentage		25.00%
Employees | 2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards | Restricted Stock Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options vesting period					5 years
Stock based compensation awards, aggregate fair value on grant date					$ 4,100
Shares granted (in shares)					82,000
Minimum | 2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards | Performance Restricted Stock Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	73,000
Share-based compensation grant date fair value	$ 3,500
Percent issued at vesting date					0.00%
Maximum | 2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards | Performance Restricted Stock Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	91,000
Share-based compensation grant date fair value	$ 4,400
Percent issued at vesting date					125.00%

Stock-Based Compensation and 92

Stock-Based Compensation and Other Benefit Plans - Schedule of Other Than Equity Activity (Detail) - 2016 Stock Incentive Plan - Restricted Stock Awards and Restricted Stock Unit Awards	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Restricted Stock Awards
Shares
Outstanding at January 1, 2017 | shares	81,000
Granted | shares	84,000
Vested | shares	(68,000)
Canceled or forfeited | shares	0
Outstanding at December 31, 2017 | shares	96,000
Weighted Average Grant Date Fair Value
Outstanding at January 1, 2017 | $ / shares	$ 34.47
Granted | $ / shares	47.85
Vested | $ / shares	39.93
Canceled or forfeited | $ / shares	0
Outstanding at December 31, 2017 | $ / shares	$ 42.23
Restricted Stock Unit Awards
Shares
Outstanding at January 1, 2017 | shares	0
Granted | shares	106,615
Vested | shares	(19,000)
Canceled or forfeited | shares	0
Outstanding at December 31, 2017 | shares	88,015
Weighted Average Grant Date Fair Value
Outstanding at January 1, 2017 | $ / shares	$ 0
Granted | $ / shares	49.49
Vested | $ / shares	45.45
Canceled or forfeited | $ / shares	0
Outstanding at December 31, 2017 | $ / shares	$ 50.34
Performance Restricted Stock Unit Awards
Shares
Outstanding at January 1, 2017 | shares	0
Granted | shares	73,144
Vested | shares	0
Canceled or forfeited | shares	0
Outstanding at December 31, 2017 | shares	73,144
Weighted Average Grant Date Fair Value
Outstanding at January 1, 2017 | $ / shares	$ 0
Granted | $ / shares	47.85
Vested | $ / shares	0
Canceled or forfeited | $ / shares	0
Outstanding at December 31, 2017 | $ / shares	$ 47.85

Stock-Based Compensation and 93

Stock-Based Compensation and Other Benefit Plans - Florida Community Bank, N.A. 401(k) Plan - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
401 (k) Plan, matching employer contribution percentage	100.00%
401 (k) Plan, percentage of compensation matched	3.00%
Years of service after which matching contributions are fully vested	3 years
Total 401(k) matching employer contribution expense	$ 1,100	$ 978	$ 868

Stock-Based Compensation and 94

Stock-Based Compensation and Other Benefit Plans - Executive Incentive Plan - Additional Information (Detail) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Annual Incentive Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 6,000	$ 6,000	$ 5,100
Executive Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average life over which expense is expected to be recognized (years)	3 years
Cash Phantom Units (CPUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 105	$ 377	$ 1,100
Shares settled under award plan	103

Stock-Based Compensation and 95

Stock-Based Compensation and Other Benefit Plans - Management Long Term Incentive Plan - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Management long-term incentive plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 792	$ 1,100

Basic and Diluted Earnings Pe96

Basic and Diluted Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income available to common stockholders	$ 18,964	$ 32,160	$ 35,081	$ 38,989	$ 27,896	$ 26,064	$ 23,504	$ 22,452	$ 125,194	$ 99,916	$ 53,391
Weighted average number of common shares—basic									42,887,142	40,716,588	41,300,979
Effect of dilutive securities:
Employee stock-based compensation awards and warrants									3,233,788	2,508,576	1,992,628
Weighted average number of common shares—diluted									46,120,930	43,225,164	43,293,607
Basic earnings per share	$ 0.43	$ 0.74	$ 0.82	$ 0.93	$ 0.68	$ 0.64	$ 0.58	$ 0.55	$ 2.92	$ 2.45	$ 1.29
Diluted earnings per share	$ 0.41	$ 0.70	$ 0.76	$ 0.86	$ 0.64	$ 0.60	$ 0.55	$ 0.52	$ 2.71	$ 2.31	$ 1.23
Weighted average number of anti-dilutive equity awards									29,114	330,095	91,923

Income Taxes - Components of Ex

Income Taxes - Components of Expense and Benefit for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current income tax expense:
Federal									$ 24,036	$ 39,528	$ 23,610
State									3,800	6,013	3,441
Total current income tax expense									27,836	45,541	27,051
Deferred income tax expense (benefit):
Federal									24,795	9,161	(19,157)
State									1,534	1,203	(2,238)
Total deferred income tax expense (benefit)									26,329	10,364	(21,395)
Total income tax expense (benefit)	$ 27,976	$ 13,936	$ 8,312	$ 3,941	$ 15,194	$ 14,330	$ 13,697	$ 12,684	$ 54,165	$ 55,905	$ 5,656

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Provisional income tax expense (benefit)		$ 14,300,000
Tax expense (benefit) at federal income tax rate		35.00%	35.00%	35.00%
Deferred tax assets for federal net operating losses		$ 5,755,000	$ 9,287,000
Deferred tax assets for state net operating losses		534,000	921,000
Reversal of valuation allowance	$ 9,100,000
Uncertain tax positions		0	0	$ 0
Interest and penalties associated with income taxes		$ 0	$ 0	$ 0
Minimum
Income Taxes [Line Items]
Operating loss carryforwards expiration year		2,028
Maximum
Income Taxes [Line Items]
Operating loss carryforwards expiration year		2,034

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Expected Income Tax Expense or Benefit at Statutory Federal Income Tax Rate to Actual Income Tax Expense or Benefit and Effective Tax Rate (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Deferred Tax Liabilities, Financing Arrangements	$ 947				$ 7,542				$ 947	$ 7,542
Income tax expense or benefit
Tax expense (benefit) at federal income tax rate									62,776	54,537	$ 20,667
Bank-owned life insurance									(3,186)	(1,817)	(1,614)
Stock compensation and excess tax benefit									(20,098)	234	729
Dividends received deduction									(1,631)	(1,919)	(2,104)
GFB NUBIL Revaluation									0	0	(4,954)
NOL Valuation Allowance									0	0	(9,061)
State tax, net of federal benefit									3,528	4,777	1,619
Federal tax rate change									14,301	0	0
Other									(1,525)	93	374
Total income tax expense (benefit)	$ 27,976	$ 13,936	$ 8,312	$ 3,941	$ 15,194	$ 14,330	$ 13,697	$ 12,684	$ 54,165	$ 55,905	$ 5,656
Effective tax rates
Tax expense (benefit) at federal income tax rate									35.00%	35.00%	35.00%
Bank-owned life insurance									(1.78%)	(1.17%)	(2.73%)
Stock compensation and excess tax benefit									(11.21%)	0.15%	1.23%
Dividends received deduction									(0.91%)	(1.23%)	(3.56%)
GFB NUBIL Revaluation									0.00%	0.00%	(8.39%)
NOL Valuation Allowance									0.00%	0.00%	(15.35%)
State tax, net of federal benefit									1.97%	3.07%	2.74%
Federal tax rate change									7.97%	0.00%	0.00%
Other									(0.85%)	0.06%	0.62%
Total									30.19%	35.88%	9.56%

Income Taxes - Significant Comp

Income Taxes - Significant Components of Net Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Excess tax basis over carrying value of assets	$ 1,456	$ 12,991
Excess carrying value over tax basis of liabilities	0	324
Net operating loss carry forward:
Federal	5,755	9,287
State	534	921
Total	6,289	10,208
Amortization	11,717	21,555
Depreciation	0	660
Unrealized losses on securities available for sale	0	2,509
Allowance for loan losses	11,087	12,807
Non-qualified stock options and restricted stock	3,869	7,695
Other	469	2,696
Gross deferred tax assets	34,887	71,445
Valuation allowance	0	0
Gross deferred tax assets, net of valuation allowance	34,887	71,445
Deferred tax liabilities:
Loans	(947)	(7,542)
Depreciation	(239)	0
Restricted securities	(1,475)	(2,260)
Unrealized gains on securities available for sale	3,594	0
Other	(1,589)	(252)
Gross deferred tax liabilities	(7,844)	(10,054)
Deferred tax assets (liabilities), net	27,043	61,391
Other Real Estate Owned
Deferred tax assets:
Excess tax basis over carrying value of assets	1,456	12,991
Repo Loans
Deferred tax assets:
Excess carrying value over tax basis of liabilities	$ 0	$ 324

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Reserve for unfunded commitments	$ 1.1	$ 1.6

Commitments and Contingencie102

Commitments and Contingencies - Summary of Unfunded Commitments (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Unfunded credit extension commitments	$ 1,544,512	$ 1,160,648
Commitments to fund loans
Line of Credit Facility [Line Items]
Unfunded credit extension commitments	926,405	724,380
Unused lines of credit
Line of Credit Facility [Line Items]
Unfunded credit extension commitments	571,587	410,068
Commercial and standby letters of credit
Line of Credit Facility [Line Items]
Unfunded credit extension commitments	$ 46,520	$ 26,200

Parent Company Financial Sta103

Parent Company Financial Statements - Condensed Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets:
Cash and due from banks	$ 60,787	$ 52,903
Available for sale securities	2,120,803	1,876,434
Other assets	76,065	59,347
Total assets	10,677,079	9,090,134
Liabilities and stockholders' equity:
Total liabilities	9,497,907	8,107,693
Stockholders’ equity	1,179,172	982,441	$ 876,109	$ 851,653
Total liabilities and stockholders’ equity	10,677,079	9,090,134
Parent company
Assets:
Cash and due from banks	10,271	18,126
Available for sale securities	179,815	129,970
Investment in bank subsidiary	1,025,677	885,296
Other assets	13,894	9,874
Total assets	1,229,657	1,043,266
Liabilities and stockholders' equity:
Total liabilities	50,783	61,182
Stockholders’ equity	1,178,874	982,084
Total liabilities and stockholders’ equity	$ 1,229,657	$ 1,043,266

Parent Company Financial Sta104

Parent Company Financial Statements - Condensed Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income:
Interest and dividends on investment securities									$ 78,176	$ 60,706	$ 52,741
Gain on investment securities									1,933	1,819	1,906
Expense:
Interest on borrowings									12,583	7,271	5,103
Stock-based compensation expense									8,038	5,613	5,290
Professional services									5,940	5,207	5,412
Other noninterest expense									6,692	7,199	5,924
Total noninterest expense	$ 36,119	$ 35,239	$ 35,252	$ 35,084	$ 33,646	$ 33,036	$ 33,975	$ 33,300	141,694	133,957	126,604
Income before income tax expense	46,940	46,096	43,393	42,930	43,090	40,394	37,201	35,136
Income tax expense	27,976	13,936	8,312	3,941	15,194	14,330	13,697	12,684	54,165	55,905	5,656
Net income	$ 18,964	$ 32,160	$ 35,081	$ 38,989	$ 27,896	$ 26,064	$ 23,504	$ 22,452	125,194	99,916	53,391
Parent company
Income:
Interest and dividends on investment securities									8,079	7,831	8,602
Gain on investment securities									2,032	(586)	688
Total income									10,111	7,245	9,290
Expense:
Interest on borrowings									770	884	551
Stock-based compensation expense									1,126	577	829
Professional services									922	707	950
Directors fees									401	800	598
Insurance expense									768	1,034	1,505
Other noninterest expense									8,372	7,261	6,500
Total noninterest expense									12,359	11,263	10,933
Income before income tax expense									(2,248)	(4,018)	(1,643)
Income tax expense									(5,494)	(3,671)	(2,901)
Income (loss) before equity in undistributed income of subsidiaries									3,246	(347)	1,258
Equity in income of subsidiary									121,948	100,263	52,133
Net income									$ 125,194	$ 99,916	$ 53,391

Parent Company Financial Sta105

Parent Company Financial Statements - Condensed Statements of Comprehensive Income (Loss) (Detail) - 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 Statement of Income Captions [Line Items]
Net income	$ 18,964	$ 32,160	$ 35,081	$ 38,989	$ 27,896	$ 26,064	$ 23,504	$ 22,452	$ 125,194	$ 99,916	$ 53,391
Other comprehensive income (loss):
Unrealized net holding gains (losses) on investment securities available for sale, net of taxes of $(1,644), $(620), and $(227), respectively									14,868	7,115	(8,598)
Reclassification adjustment for (gains) losses on investment securities available for sale included in net income, net of taxes of $1,050, $63, and $384, respectively									(1,980)	(1,667)	(1,524)
Total other comprehensive income (loss)									12,888	5,448	(10,122)
Total comprehensive income									138,082	105,364	43,269
Parent company
Condensed Statement of Income Captions [Line Items]
Net income									125,194	99,916	53,391
Other comprehensive income (loss):
Unrealized net holding gains (losses) on investment securities available for sale, net of taxes of $(1,644), $(620), and $(227), respectively									2,685	988	362
Reclassification adjustment for (gains) losses on investment securities available for sale included in net income, net of taxes of $1,050, $63, and $384, respectively									(1,696)	(100)	(612)
Total other comprehensive income (loss)									989	888	(250)
Total comprehensive income									$ 126,183	$ 100,804	$ 53,141

Parent Company Financial Sta106

Parent Company Financial Statements - Condensed Statements of Comprehensive Income - Additional Information (Loss) (Detail) - Parent company - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Statement of Income Captions [Line Items]
Unrealized net holding gains (losses) on investment securities available for sale, taxes	$ (1,644)	$ (620)	$ (227)
Reclassification adjustment for (gains) losses on investment securities available for sale included in net income (loss), Taxes	$ 1,050	$ 63	$ 384

Parent Company Financial Sta107

Parent Company Financial Statements - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows From Operating Activities:
Net income	$ 18,964	$ 32,160	$ 35,081	$ 38,989	$ 27,896	$ 26,064	$ 23,504	$ 22,452	$ 125,194	$ 99,916	$ 53,391
Adjustments to reconcile net income to net cash used in operating activities:
Amortization (accretion) of premium (discount) on investment securities									2,166	1,586	1,883
(Gain) loss on investment securities									(1,933)	(1,819)	(1,906)
Depreciation of premises and equipment									3,600	3,600	3,800
Deferred tax expense									26,329	10,364	(21,395)
Net change in operating assets and liabilities:
Net change in other assets									(14,112)	8,499	49
Net change in other liabilities									6,679	(10,717)	(12,539)
Net cash provided by (used in) operating activities									164,146	98,077	68,220
Cash Flows From Investing Activities:
Purchases of investment securities available for sale									(884,732)	(750,482)	(676,708)
Sales of investment securities available for sale									223,726	342,137	354,733
Payments and maturities of investment securities									451,974	89,421	139,996
Net cash provided by (used in) investing activities									(1,549,824)	(1,757,654)	(1,418,992)
Cash Flows From Financing Activities:
Repurchase common stock									0	(23,738)	(34,884)
Exercise of stock options									50,670	17,042	8,793
Excess tax benefit from share based payments									0	2,110	2,048
Net change in repurchase agreements									(78,894)	(15,195)	94,997
Net cash provided by (used in) financing activities									1,417,723	1,640,993	1,346,147
Net Change in Cash and Cash Equivalents									32,045	(18,584)	(4,625)
Cash and Cash Equivalents at Beginning of Period				83,876				102,460	83,876	102,460	107,085
Cash and Cash Equivalents at End of Period	115,921				83,876				115,921	83,876	102,460
Parent company
Cash Flows From Operating Activities:
Net income									125,194	99,916	53,391
Adjustments to reconcile net income to net cash used in operating activities:
Equity in earnings of subsidiaries									(121,948)	(100,263)	(52,133)
Amortization (accretion) of premium (discount) on investment securities									(13)	0	0
(Gain) loss on investment securities									(2,032)	586	(688)
Stock-based compensation and warrant expense									1,124	577	829
Depreciation of premises and equipment									0	0	1
Deferred tax expense									3,126	(735)	1,272
Net change in operating assets and liabilities:
(Increase)/decrease in due from subsidiaries									(472)	4,478	8,476
Increase/(decrease) in due to subsidiaries									(1,745)	1,745	(1,979)
Net change in other assets									1,332	1,382	1,052
Net change in other liabilities									(8,109)	(4,365)	(2,806)
Net cash provided by (used in) operating activities									(3,543)	3,321	7,415
Cash Flows From Investing Activities:
Purchases of investment securities available for sale									(102,988)	(67,934)	(169,728)
Sales of investment securities available for sale									56,791	106,347	110,649
Payments and maturities of investment securities									0	0	2,005
Capital contribution									0	0	(35,000)
Net cash provided by (used in) investing activities									(46,197)	38,413	(92,074)
Cash Flows From Financing Activities:
Repurchase common stock									0	(23,738)	(34,884)
Exercise of stock options									50,670	17,042	8,793
Excess tax benefit from share based payments									0	2,110	2,048
Net change in repurchase agreements									(8,785)	(28,134)	87,254
Net cash provided by (used in) financing activities									41,885	(32,720)	63,211
Net Change in Cash and Cash Equivalents									(7,855)	9,014	(21,448)
Cash and Cash Equivalents at Beginning of Period				$ 18,126				$ 9,112	18,126	9,112	30,560
Cash and Cash Equivalents at End of Period	$ 10,271				$ 18,126				$ 10,271	$ 18,126	$ 9,112

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - Fair value, measurements, recurring - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Assets, fair value	$ 2,132,636	$ 1,891,702
Liabilities:
Liabilities, fair value	11,833	15,268
Derivative liabilities—Interest rate contracts | Interest rate contracts
Liabilities:
Liabilities, fair value	11,833	15,268
Level 1
Assets:
Assets, fair value	68,924	60,425
Liabilities:
Liabilities, fair value	0	0
Level 1 | Derivative liabilities—Interest rate contracts | Interest rate contracts
Liabilities:
Liabilities, fair value	0	0
Level 2
Assets:
Assets, fair value	2,063,712	1,831,277
Liabilities:
Liabilities, fair value	11,833	15,268
Level 2 | Derivative liabilities—Interest rate contracts | Interest rate contracts
Liabilities:
Liabilities, fair value	11,833	15,268
Level 3
Assets:
Assets, fair value	0	0
Liabilities:
Liabilities, fair value	0	0
Level 3 | Derivative liabilities—Interest rate contracts | Interest rate contracts
Liabilities:
Liabilities, fair value	0	0
U.S. Government agencies and sponsored enterprises obligations
Assets:
Assets, fair value	42,838	16,314
U.S. Government agencies and sponsored enterprises obligations | Level 1
Assets:
Assets, fair value	0	0
U.S. Government agencies and sponsored enterprises obligations | Level 2
Assets:
Assets, fair value	42,838	16,314
U.S. Government agencies and sponsored enterprises obligations | Level 3
Assets:
Assets, fair value	0	0
U.S. Government agencies and sponsored enterprises mortgage-backed securities
Assets:
Assets, fair value	595,237	558,446
U.S. Government agencies and sponsored enterprises mortgage-backed securities | Level 1
Assets:
Assets, fair value	0	0
U.S. Government agencies and sponsored enterprises mortgage-backed securities | Level 2
Assets:
Assets, fair value	595,237	558,446
U.S. Government agencies and sponsored enterprises mortgage-backed securities | Level 3
Assets:
Assets, fair value	0	0
State and municipal obligations
Assets:
Assets, fair value	26,172	27,679
State and municipal obligations | Level 1
Assets:
Assets, fair value	0	0
State and municipal obligations | Level 2
Assets:
Assets, fair value	26,172	27,679
State and municipal obligations | Level 3
Assets:
Assets, fair value	0	0
Asset-backed securities
Assets:
Assets, fair value	610,546	577,823
Asset-backed securities | Level 1
Assets:
Assets, fair value	0	0
Asset-backed securities | Level 2
Assets:
Assets, fair value	610,546	577,823
Asset-backed securities | Level 3
Assets:
Assets, fair value	0	0
Corporate bonds and other debt securities
Assets:
Assets, fair value	755,903	559,294
Corporate bonds and other debt securities | Level 1
Assets:
Assets, fair value	55,970	53,517
Corporate bonds and other debt securities | Level 2
Assets:
Assets, fair value	699,933	505,777
Corporate bonds and other debt securities | Level 3
Assets:
Assets, fair value	0	0
Preferred stocks and other equity securities
Assets:
Assets, fair value	90,107	136,878
Preferred stocks and other equity securities | Level 1
Assets:
Assets, fair value	12,954	6,908
Preferred stocks and other equity securities | Level 2
Assets:
Assets, fair value	77,153	129,970
Preferred stocks and other equity securities | Level 3
Assets:
Assets, fair value	0	0
Derivative assets—Interest rate contracts | Interest rate contracts
Assets:
Assets, fair value	11,833	15,268
Derivative assets—Interest rate contracts | Level 1 | Interest rate contracts
Assets:
Assets, fair value		0
Derivative assets—Interest rate contracts | Level 2 | Interest rate contracts
Assets:
Assets, fair value	11,833	15,268
Derivative assets—Interest rate contracts | Level 3 | Interest rate contracts
Assets:
Assets, fair value	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Transfers of financial assets between levels of the fair value hierarchy	$ 0	$ 53.5

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Changes in Fair Value of Liabilities Measured at Fair Value on Recurring Basis and Classified in Level 3 of Fair Value Hierarchy for Periods Presented (Detail) - Clawback Liability - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 0	$ 0	$ 13,846
Termination of FDIC loss sharing agreements	0	0	(13,846)
Balance at end of period	$ 0	$ 0	$ 0

Fair Value Measurements - Signi

Fair Value Measurements - Significant Unobservable Inputs in Fair Value Measurement Level 3 Assets and Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Other real estate owned	$ 14,906	$ 19,228
Level 3
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair value, loans	7,877,094	6,556,914
Level 3 | Fair value, measurements, nonrecurring | Impaired loans
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair value, loans	6,153	8,878
Level 3 | Fair value, measurements, nonrecurring | Other Real Estate Owned
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Other real estate owned	$ 14,906	$ 19,228
Discount rate	10.00%
Minimum | Level 3 | Fair value, measurements, nonrecurring | Impaired loans
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Discount rate	0.00%
Maximum | Level 3 | Fair value, measurements, nonrecurring | Impaired loans
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Discount rate	100.00%
Weighted average | Level 3 | Fair value, measurements, nonrecurring | Impaired loans
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Discount rate	7.60%

Fair Value Measurements - Su112

Fair Value Measurements - Summary of Fair Value Measurements Related to Collateral Dependent Impaired Loans and OREO are Classified Within Level 3 of the Fair Value Hierarchy (Detail) - Fair value, measurements, nonrecurring - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Impaired loans
Negative valuation adjustments:
Negative fair valuation adjustments	$ 0	$ 700	$ 1,071
Foreclosed real estate
Negative valuation adjustments:
Negative fair valuation adjustments	$ 670	$ 1,219	$ 674

Fair Value Measurements - Sc113

Fair Value Measurements - Schedule of Carrying Amounts and Estimated Fair Values, as well as the Level Within the Fair Value Hierarchy (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financial Assets:
Cash and cash equivalents	$ 115,921	$ 83,876	$ 102,460	$ 107,085
Available for sale securities	2,120,803	1,876,434
FHLB and other bank stock	56,881	51,656
Loans held for sale	12,736	20,220
Bank-owned life insurance	201,069	198,438
Financial Liabilities:
Deposits	8,673,927	7,305,671
Advances from the FHLB and other borrowings	749,113	751,103
Carrying Value
Financial Assets:
Cash and cash equivalents	115,921	83,876
Available for sale securities	2,120,803	1,876,434
FHLB and other bank stock	56,881	51,656
Loans, net	7,930,639	6,596,997
Loans held for sale	12,736	20,220
Bank-owned life insurance	201,069	198,438
Derivative assets—Interest rate contracts	11,833	15,268
Financial Liabilities:
Deposits	8,673,927	7,305,671
Advances from the FHLB and other borrowings	749,113	751,103
Derivative liabilities—Interest rate contracts	11,833	15,268
Fair Value
Financial Assets:
Cash and cash equivalents	115,921	83,876
Available for sale securities	2,120,803	1,876,434
FHLB and other bank stock	56,881	51,656
Loans, net	7,877,094	6,556,914
Loans held for sale	12,736	20,220
Bank-owned life insurance	201,069	198,438
Derivative assets—Interest rate contracts	11,833	15,268
Financial Liabilities:
Deposits	8,664,125	7,306,148
Advances from the FHLB and other borrowings	740,941	745,855
Derivative liabilities—Interest rate contracts	11,833	15,268
Level 1
Financial Assets:
Cash and cash equivalents	115,921	83,876
Available for sale securities	68,924	60,425
FHLB and other bank stock	0	0
Loans, net	0	0
Loans held for sale	0	0
Bank-owned life insurance	0	0
Derivative assets—Interest rate contracts	0	0
Financial Liabilities:
Deposits	0	0
Advances from the FHLB and other borrowings	0	0
Derivative liabilities—Interest rate contracts	0	0
Level 2
Financial Assets:
Cash and cash equivalents	0	0
Available for sale securities	2,051,879	1,816,009
FHLB and other bank stock	56,881	51,656
Loans, net	0	0
Loans held for sale	12,736	20,220
Bank-owned life insurance	201,069	198,438
Derivative assets—Interest rate contracts	11,833	15,268
Financial Liabilities:
Deposits	8,664,125	7,306,148
Advances from the FHLB and other borrowings	740,941	745,855
Derivative liabilities—Interest rate contracts	11,833	15,268
Level 3
Financial Assets:
Cash and cash equivalents	0	0
Available for sale securities	0	0
FHLB and other bank stock	0	0
Loans, net	7,877,094	6,556,914
Loans held for sale	0	0
Bank-owned life insurance	0	0
Derivative assets—Interest rate contracts	0	0
Financial Liabilities:
Deposits	0	0
Advances from the FHLB and other borrowings	0	0
Derivative liabilities—Interest rate contracts	$ 0	$ 0

Quarterly Financial Data (Un114

Quarterly Financial Data (Unaudited) - Summary of Quarterly Financial Data (Detail) - 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
Selected Income Statement data:
Interest income	$ 101,490	$ 96,816	$ 90,573	$ 85,222	$ 85,580	$ 80,800	$ 77,208	$ 75,728	$ 374,101	$ 319,316	$ 249,040
Interest expense	23,376	21,035	18,686	15,552	14,514	13,522	12,278	11,286	78,649	51,600	31,244
Net interest income	78,114	75,781	71,887	69,670	71,066	67,278	64,930	64,442	295,452	267,716	217,796
Provision for loan losses	2,786	2,871	2,115	1,643	2,249	1,990	1,976	1,440	9,415	7,655	6,823
Net interest income after provision for loan losses	75,328	72,910	69,772	68,027	68,817	65,288	62,954	63,002	286,037	260,061	210,973
Noninterest income	7,731	8,425	8,873	9,987	7,919	8,142	8,222	5,434	35,016	29,717	(25,322)
Noninterest expense	36,119	35,239	35,252	35,084	33,646	33,036	33,975	33,300	141,694	133,957	126,604
Income before income tax expense	46,940	46,096	43,393	42,930	43,090	40,394	37,201	35,136
Income tax expense	27,976	13,936	8,312	3,941	15,194	14,330	13,697	12,684	54,165	55,905	5,656
Net income	$ 18,964	$ 32,160	$ 35,081	$ 38,989	$ 27,896	$ 26,064	$ 23,504	$ 22,452	$ 125,194	$ 99,916	$ 53,391
Earnings per share:
Basic earnings per share	$ 0.43	$ 0.74	$ 0.82	$ 0.93	$ 0.68	$ 0.64	$ 0.58	$ 0.55	$ 2.92	$ 2.45	$ 1.29
Diluted earnings per share	$ 0.41	$ 0.70	$ 0.76	$ 0.86	$ 0.64	$ 0.60	$ 0.55	$ 0.52	$ 2.71	$ 2.31	$ 1.23