First NBC Bank Holding (FNBCQ) 10-K 31 Mar 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2013	Mar. 24, 2014	Jun. 30, 2013
Document And Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Trading Symbol	'NBCB	'	'
Entity Registrant Name	'First NBC Bank Holding Co	'	'
Entity Central Index Key	'0001496631	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Well-known Seasoned Issuer	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Filer Category	'Non-accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	18,521,831	'
Entity Public Float	'	'	$378,097,056

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets	'	'
Cash and due from banks	$28,140	$26,471
Short-term investments	3,502	9,541
Investment in short-term receivables	246,817	81,044
Investment securities available for sale, at fair value	277,719	405,355
Investment securities held to maturity	94,904	'
Mortgage loans held for sale	6,577	25,860
Loans, net of allowance for loan losses of $32,143 and $26,977, respectively	2,325,634	1,895,240
Bank premises and equipment, net	51,174	47,067
Accrued interest receivable	10,994	8,728
Goodwill and other intangible assets	8,433	8,682
Investment in real estate properties	10,147	6,935
Investment in tax credit entities	117,684	67,393
Cash surrender value of bank-owned life insurance	26,187	25,506
Other real estate	3,733	8,632
Deferred tax asset	51,191	16,589
Receivables from sales of investments	'	16,909
Other assets	23,781	20,915
Total assets	3,286,617	2,670,867
Deposits:	'	'
Noninterest-bearing	291,080	239,538
Interest-bearing	2,439,727	2,028,990
Total deposits	2,730,807	2,268,528
Short-term borrowings	8,425	21,800
Repurchase agreements	75,957	36,287
Long-term borrowings	55,110	75,220
Accrued interest payable	6,682	5,557
Other liabilities	27,777	15,373
Total liabilities	2,904,758	2,422,765
Shareholders' equity:	'	'
Common stock- par value $1 per share; 100,000,000 shares authorized; 18,514,271 shares issued and outstanding at December 31, 2013 and 13,052,583 shares issued and outstanding at December 31, 2012	18,514	13,052
Additional paid-in capital	237,063	128,984
Accumulated earnings	100,389	59,825
Accumulated other comprehensive loss, net	-16,515	-2,926
Total shareholders' equity	381,857	248,101
Noncontrolling interest	2	1
Total equity	381,859	248,102
Total liabilities and equity	3,286,617	2,670,867
Convertible Preferred Stock Series C [Member]	'	'
Shareholders' equity:	'	'
Preferred stock	4,471	11,231
Series D Preferred Stock [Member]	'	'
Shareholders' equity:	'	'
Preferred stock	$37,935	$37,935

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Allowance for loan losses	$32,143	$26,977
Common stock, par value per share	$1	$1
Common stock, shares authorized	100,000,000,000	100,000,000,000
Common stock, shares issued	18,514,271,000	13,052,583,000
Common stock, shares outstanding	18,514,271,000	13,052,583,000
Convertible Preferred Stock Series C [Member]	'	'
Preferred stock, par value	$0	$0
Preferred stock, share authorized	1,680,219,000	1,680,219,000
Preferred stock, share issued	364,983,000	916,841,000
Preferred stock, share outstanding	364,983,000	916,841,000
Series D Preferred Stock [Member]	'	'
Preferred stock, par value	$0	$0
Preferred stock, share authorized	37,935,000	37,935,000
Preferred stock, share issued	37,935,000	37,935,000
Preferred stock, share outstanding	37,935,000	37,935,000

CONSOLIDATED_STATEMENTS_OF_INC

CONSOLIDATED STATEMENTS OF INCOME (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Interest income:	'	'	'
Loans, including fees	$111,260	$97,754	$74,770
Investment securities	8,170	6,499	3,938
Investment in short-term receivables	4,449	2,060	138
Short-term investments	145	144	168
Total interest income	124,024	106,457	79,014
Interest expense:	'	'	'
Deposits	36,239	29,597	24,885
Borrowings and securities sold under repurchase agreements	2,909	2,069	1,482
Total interest expense	39,148	31,666	26,367
Net interest income	84,876	74,791	52,647
Provision for loan losses	9,800	11,035	8,010
Net interest income after provision for loan losses	75,076	63,756	44,637
Noninterest income:	'	'	'
Service charges on deposit accounts	2,027	2,486	1,577
Investment securities gain, net	316	4,324	485
Gain (loss) on assets sold, net	1,071	500	-147
Gain on sale of loans, net	835	603	779
Cash surrender value income on bank-owned life insurance	681	750	621
Income from sales of state tax credits	2,785	578	951
Community Development Entity fees	2,875	1,136	670
ATM fee income	1,859	1,686	500
Other	967	1,073	515
Total non-interest income	13,416	13,136	5,951
Noninterest expense:	'	'	'
Salaries and employee benefits	23,812	20,307	11,996
Occupancy and equipment expenses	10,204	9,755	6,428
Professional fees	6,929	3,269	3,969
Taxes, licenses and FDIC assessments	4,245	3,258	2,661
Tax credit investment amortization	8,639	4,808	2,868
Write-down of other real estate	225	295	1,212
Data processing	4,219	4,485	2,308
Advertising and marketing	2,427	1,904	1,292
Other	6,632	6,926	3,513
Total non-interest expense	67,332	55,007	36,247
Income before income taxes	21,160	21,885	14,341
Income tax benefit	-19,751	-7,565	-5,407
Net income	40,911	29,450	19,748
Less net income attributable to noncontrolling interests	'	-510	-308
Net income attributable to Company	40,911	28,940	19,440
Less preferred stock dividends	-347	-510	-792
Less accretion of discount on preferred stock	'	'	-580
Income available to common shareholders	$40,564	$28,430	$18,068
Earnings per common share - basic	$2.38	$2.04	$1.55
Earnings per common share - diluted	$2.32	$2.02	$1.54

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net income	$40,911	$29,450	$19,748
Fair value of derivative instruments designated as cash flow hedges:	'	'	'
Change in fair value of derivative instruments designated as cash flow hedges during the period, before tax	3,694	-6,854	'
Unrealized (losses) gains on investment securities:	'	'	'
Unrealized (losses) gains on investment securities arising during the period	-18,576	3,956	4,814
Less: reclassification adjustment for gains included in net income	-316	-4,324	-485
Transfer of unrealized loss on securities from available for sale to held to maturity during the period	-5,708	'	'
Unrealized (losses) gains on investment securities, before tax	-24,600	-368	4,329
Other comprehensive (losses) income, before taxes	-20,906	-7,222	4,329
Income tax (benefit) expense related to items of other comprehensive (loss) income	-7,317	-2,501	1,472
Other comprehensive (loss) income, net of tax	-13,589	-4,721	2,857
Comprehensive income	27,322	24,729	22,605
Comprehensive income attributable to noncontrolling interests	'	-510	-308
Preferred Shareholders [Member]	'	'	'
Unrealized (losses) gains on investment securities:	'	'	'
Comprehensive income	-347	-510	-1,372
Common Shareholders [Member]	'	'	'
Unrealized (losses) gains on investment securities:	'	'	'
Comprehensive income	$26,975	$23,709	$20,925

CONSOLIDATED_STATEMENTS_OF_SHA

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $)	Total	Series A Preferred Stock [Member]	Series B Preferred Stock [Member]	Series C Preferred Stock [Member]	Series D Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total Shareholders' Equity [Member]	Noncontrolling Interest [Member]
In Thousands
Beginning Balance at Dec. 31, 2010	$131,033	'	'	'	'	$9,570	$89,446	$13,327	($1,062)	$129,386	$1,647
Beginning Balance at Dec. 31, 2010	'	17,244	861	'	'	'	'	'	'	'	'
Net income	19,440	'	'	'	'	'	'	19,440	'	19,440	'
Other comprehensive income	2,857	'	'	'	'	'	'	'	2,857	2,857	'
Restricted stock and share-based compensation	919	'	'	'	'	64	855	'	'	919	'
Issuance of common stock	30,226	'	'	'	'	2,519	27,707	'	'	30,226	'
Issuance (redemption) of preferred stock	39,832	-17,796	-889	20,582	37,935	'	'	'	'	39,832	'
Conversion of preferred stock to common stock	'	'	'	'	'	'	'	'	'	'	'
Issuance of common stock	30,226	'	'	'	'	2,519	27,707	'	'	30,226	'
Preferred stock dividends and discount accretion	-792	552	28	'	'	'	'	-1,372	'	-792	'
Equity contribution for noncontrolling interest	1	'	'	'	'	'	2	'	'	2	-1
Ending Balance at Dec. 31, 2011	223,516	'	'	'	'	12,153	118,010	31,395	1,795	221,870	1,646
Ending Balance at Dec. 31, 2011	'	'	'	20,582	37,935	'	'	'	'	'	'
Net income	28,940	'	'	'	'	'	'	28,940	'	28,940	'
Other comprehensive income	-4,721	'	'	'	'	'	'	'	-4,721	-4,721	'
Share-based compensation	1,102	'	'	'	'	20	1,082	'	'	1,102	'
Issuance of common stock	1,420	'	'	'	'	116	1,304	'	'	1,420	'
Conversion of preferred stock to common stock	-1,644	'	'	-9,351	'	763	8,588	'	'	'	-1,644
Issuance of common stock	1,420	'	'	'	'	116	1,304	'	'	1,420	'
Preferred stock dividends and discount accretion	-510	'	'	'	'	'	'	-510	'	-510	'
Distribution to noncontrolling interest	-1	'	'	'	'	'	'	'	'	'	-1
Ending Balance at Dec. 31, 2012	248,102	'	'	'	'	13,052	128,984	59,825	-2,926	248,101	1
Ending Balance at Dec. 31, 2012	'	'	'	11,231	37,935	'	'	'	'	'	'
Net income	40,911	'	'	'	'	'	'	40,911	'	40,911	'
Other comprehensive income	-13,589	'	'	'	'	'	'	'	-13,589	-13,589	'
Share-based compensation	1,202	'	'	'	'	'	1,202	'	'	1,202	'
Issuance of common stock	104,163	'	'	'	'	4,792	99,371	'	'	104,163	'
Conversion of preferred stock to common stock	'	'	'	-6,760	'	552	6,208	'	'	'	'
Stock option and director plans	965	'	'	'	'	87	878	'	'	965	'
Issuance of common stock	104,163	'	'	'	'	4,792	99,371	'	'	104,163	'
Warrants	125	'	'	'	'	31	94	'	'	125	'
Net tax benefit related to stock option plans	326	'	'	'	'	'	326	'	'	326	'
Preferred stock dividends and discount accretion	-347	'	'	'	'	'	'	-347	'	-347	'
Equity contribution for noncontrolling interest	1	'	'	'	'	'	'	'	'	'	1
Ending Balance at Dec. 31, 2013	381,859	'	'	'	'	18,514	237,063	100,389	-16,515	381,857	2
Ending Balance at Dec. 31, 2013	'	'	'	$4,471	$37,935	'	'	'	'	'	'

CONSOLIDATED_STATEMENTS_OF_SHA1

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013
Statement Of Stockholders Equity [Abstract]	'
Issuance direct cost	$10,837

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities	'	'	'
Net income	$40,911	$28,940	$19,440
Adjustments to reconcile net income to net cash provided by operating activities:	'	'	'
Noncontrolling interest	'	-510	-308
Deferred tax benefit	-19,937	-7,565	-5,407
Amortization of tax credit investments	8,639	4,808	2,868
Net discount accretion or premium amortization	2,633	4,245	2,463
Gain on sale of investment securities	-316	-4,324	-485
Gain on sale of other assets	-1,055	-531	'
Write-down of other real estate owned	225	295	1,212
(Gain) loss on sale of fixed assets	-16	4	147
Proceeds from sale of mortgage loans held for sale	96,677	62,014	46,150
Mortgage loans originated and held for sale	-77,394	-82,067	-46,273
Gain on sale of loans	-835	-603	-779
Provision for loan losses	9,800	11,035	8,010
Depreciation and amortization	2,963	3,351	1,932
Share-based and other compensation expense	2,124	1,102	715
Increase in cash surrender value of bank-owned life insurance	-681	-750	-621
Decrease (increase) in receivables from sales of investments	16,909	-16,909	'
Changes in operating assets and liabilities:	'	'	'
Change in other assets	-5,168	1,540	-6,854
Change in accrued interest receivable	-2,266	-1,346	-1,072
Change in accrued interest payable	1,125	725	8
Change in other liabilities	15,125	-2,758	7,224
Net cash provided by (used in) operating activities	89,463	1,198	28,678
Investing activities	'	'	'
Purchases of available for sale investment securities	-132,123	-344,093	-445,816
Proceeds from sales of available for sale investment securities	45,791	125,401	156,778
Proceeds from maturities, prepayments, and calls of available for sale investment securities	91,328	129,910	159,434
Proceeds from maturities, prepayments, and calls of held to maturity securities	1,013	'	'
Net change in investment in short-term receivables	-165,773	-70,864	26,888
Purchase of real estate properties	'	'	-228
Reimbursement of investment in tax credit entities	'	15,607	'
Purchases of investments in tax credit entities	-58,930	-20,606	-40,597
Loans originated, net of repayments	-444,592	-275,177	-324,618
Proceeds from sale of bank premises and equipment	324	16	500
Purchases of bank premises and equipment	-7,129	-18,189	-4,141
Purchases of bank-owned life insurance	'	'	-10,000
Proceeds from the sales of acquired assets	'	'	28,972
Proceeds from disposition of real estate owned	5,015	3,840	'
Reimbursement from FDIC related to acquisition	'	'	59,687
Net cash received from business combinations	'	'	49,582
Net cash used in investing activities	-665,076	-454,155	-343,559
Financing activities	'	'	'
Net change repurchase agreements	39,670	18,311	6,904
Proceeds from borrowings	8,425	41,800	40,000
Repayment of borrowings	-41,910	-1,625	-21,220
Net increase in deposits	461,073	363,846	257,814
Proceeds from sale or distributions to noncontrolling interest in subsidiary	'	'	-1
Proceeds from sale of preferred stock, net of offering costs	'	'	58,518
Proceeds from issuance of common stock, net of offering costs	104,332	1,420	30,430
Repayment of preferred stock	'	-1,644	-18,685
Dividends paid	-347	-510	-792
Net cash provided by financing activities	571,243	421,598	352,968
Net change in cash, due from banks, and short-term investments	-4,370	-31,359	38,087
Cash, due from banks, and short-term investments at beginning of period	36,012	67,371	29,284
Cash, due from banks, and short-term investments at end of period	31,642	36,012	67,371
Supplemental cash flows information	'	'	'
Cash paid for interest	$38,023	$32,392	$24,812

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	1. Summary of Significant Accounting Policies
	Nature of Operations
	First NBC Bank Holding Company (“Company”) is a bank holding company that offers a broad range of financial services through First NBC Bank, a Louisiana state non-member bank, to businesses, institutions, and individuals in southeastern Louisiana and the Mississippi Gulf Coast. The accounting and reporting policies of the Company conform to accounting principles generally accepted in the United States and to prevailing practices within the banking industry.
	Principles of Consolidation
	The accompanying consolidated financial statements include the accounts of the Company and First NBC Bank, and First NBC Bank’s wholly owned subsidiaries, which include First NBC Community Development, LLC (FNBC CDC), First NBC Community Development Fund, LLC (FNBC CDE) (collectively referred to as the Bank) and any variable interest entities (VIE) of which the Company is the primary beneficiary. Substantially all of the VIEs that the Company is primary beneficiary relate to tax credit investments. FNBC CDC is a Community Development Corporation formed to construct, purchase, and renovate affordable residential real estate properties in the New Orleans area. FNBC CDE is a Community Development Entity (CDE) formed to apply for and receive allocations of Federal New Markets Tax Credits (NMTC).
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are susceptible to a significant change in the near term are the allowance for loan losses, income tax provision, fair value adjustments and share-based compensation.
	Concentration of Credit Risk
	The Company’s loan portfolio consists of the various types of loans described in Note 6. Real estate or other assets secure most loans. The majority of these loans have been made to individuals and businesses in the Company’s market area of southeastern Louisiana and southern Mississippi, which are dependent on the area economy for their livelihoods and servicing of their loan obligations. The Company does not have any significant concentrations to any one industry or customer.
	The Company maintains deposits in other financial institutions that may, from time to time, exceed the federally insured deposit limits.
	Cash and Cash Equivalents
	For purposes of reporting cash flows, cash and cash equivalents include the amount in the accompanying consolidated balance sheet caption, cash and due from banks, which represents cash on hand and balances due from other financial institutions, as well as the amount in the accompanying consolidated balance sheet caption, short-term investments, which primarily represents federal funds sold with original maturities less than three months.
	Investment Securities
	Investment securities are classified either as held to maturity or available for sale. Management determines the classification of securities when they are purchased.
	Investment securities that the Company has the ability and positive intent to hold to maturity are classified as securities held to maturity and are stated at amortized cost. The amortized cost of debt securities classified as held to maturity or available for sale is adjusted for amortization of premiums and accretion of discounts over the contractual life of the security using the effective interest method or, in the case of mortgage-backed securities, over the estimated life of the security using the effective yield method. Such amortization or accretion is included in interest income on securities.
	Securities that may be sold in response to changes in interest rates, liquidity needs, or asset liability management strategies, are classified as securities available for sale. These securities are carried at fair value, with net unrealized gains or losses excluded from earnings and shown as a separate component of shareholders’ equity in accumulated other comprehensive (loss) income, net of income taxes. Any expected credit loss due to the inability to collect all amounts due accordingly to the security’s contractual terms is recognized as a charge against earnings. Any remaining unrealized loss related to other factors would be recognized in other comprehensive income, net of taxes.
	Realized gains and losses on both held to maturity securities and available for sale securities are computed based on the specific-identification method. Realized gains and losses and declines in value judged to be other than temporary are included in net securities gains and losses.
	Unrealized losses on securities are evaluated to determine if the losses are temporary, based on various factors, including the cause of the loss, prospects for recovery, projected cash flows, collateral values, credit enhancements and other relevant factors, and management’s intent and ability not to sell the security until the fair value exceeds amortized cost. A charge is recognized against earnings for all or a portion of the impairment if the loss is determined to be other than temporary.
	Investment in Short-Term Receivables
	The Company invests in short-term receivables which are purchased on an exchange. These short-term receivables have repayment terms of less than a year. The investments are recorded on the consolidated balance sheets at cost plus accreted discount.
	Mortgage Loans Held for Sale
	Mortgage loans originated and intended for sale in the secondary market are carried at the lower of cost or estimated fair value, in the aggregate. Net unrealized losses, if any, are recognized through a valuation allowance that is recorded as a charge to income. Loans held for sale have primarily been fixed-rate, single-family residential mortgage loans under contract to be sold in the secondary market. In most cases, loans in this category are sold within 120 days. These loans are sold with the mortgage servicing rights released. Buyers generally have recourse to return a purchased loan to the Company under limited circumstances which may include early payment default, breach of representations or warranties, and documentation deficiencies. During 2013 and 2012, an insignificant number of loans were returned to the Company.
	Loans
	Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are stated at the principal amount outstanding, net of unamortized fees and costs on originated loans and allowances for loan losses. Loan origination fees and certain direct loan origination costs are deferred and amortized over the lives of the respective loans as a yield adjustment using the effective interest method.
	Interest income on loans is accrued as earned using the interest method over the life of the loan. Interest on loans deemed uncollectible is excluded from income. The accrual of interest is discontinued and reversed against current income once loans become more than 90 days past due or earlier if conditions warrant. The past due status of loans is determined based on the contractual terms. If the decision is made to continue accruing interest on the loan, periodic reviews are made to confirm the accruing status of the loan. When a loan is placed on nonaccrual status, interest accrued and unpaid during prior periods is reversed. Generally any payments on nonaccrual loans are applied first to outstanding loan principal amounts and then to the recovery of the charged-off loan amounts. Any excess is treated as recovery of lost interest and fees. Loans are returned to accrual status after a minimum of six consecutive monthly payments have been made in a timely manner.
	The Company considers a loan to be impaired when, based upon current information and events, it believes it is probable that the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement. The Company’s impaired loans include troubled debt restructurings (TDRs) and performing and nonperforming loans for which full payment of principal or interest is not expected. The Company calculates a reserve required for impaired loans based on the present value of expected future cash flows discounted using the loan’s effective interest rate or the fair value of the collateral securing the loan.
	Third-party property valuations are obtained at the time of origination for real estate-secured loans. The Company obtains updated appraisals on all impaired loans at least annually. In addition, if an intervening event occurs that, in management’s opinion, would suggest further deterioration in value, the Company obtains an updated appraisal. These policies do not vary based on loan type. Any exposure arising from the deterioration in value of collateral evidenced by the appraisal is recorded as an adjustment to the loan loss reserve in the case of an impaired loan or as an adjustment to income in the case of foreclosed property.
	Troubled Debt Restructurings
	The Company periodically grants concessions to its customers in an attempt to protect as much of its investment as possible and minimize the risk of loss. These concessions may include restructuring the terms of a customer loan, thereby adjusting the customer’s payment requirements. In order to be considered a TDR, the Company must conclude that the restructuring constitutes a concession and the customer is experiencing financial difficulties. The Company defines a concession to a customer as a modification of existing loan terms for economic or legal reasons that it would otherwise not consider. Concessions are typically granted through an agreement with the customer or are imposed by a court of law. Concessions include modifying original loan terms to reduce or defer cash payments required as part of the loan agreement, including but not limited to:
		•		A reduction of the stated interest rate for the remaining original life of the debt
		•		Extension of the maturity date or dates at a stated interest rate lower than the current market rate for new debt with similar risk characteristics
		•		Reduction of the face amount or maturity amount of the debt as stated in the agreement
		•		Reduction of accrued interest receivable on the debt
	In its determination of whether the customer is experiencing financial difficulties, the Company considers numerous indicators, including but not limited to:
		•		Whether the customer is currently in default on its existing loan, or is in an economic position where it is probable the customer will be in default on its loan in the foreseeable future without a modification
		•		Whether the customer has declared or is in the process of declaring bankruptcy
		•		Whether there is substantial doubt about the customer’s ability to continue as a going concern
		•		Whether, based on its projections of the customer’s current capabilities, the Company believes the customer’s future cash flows will be insufficient to service the debt, including interest, in accordance with the contractual terms of the existing agreement for the foreseeable future
		•		Whether, without modification, the customer cannot obtain sufficient funds from other sources at an effective interest rate equal to the current market rate for similar debt for a nontroubled debtor
	If the Company concludes that both a concession has been granted and the concession was granted to a customer experiencing financial difficulties, the Company identifies the loan as a TDR. For purposes of the determination of an allowance for loan losses on these TDRs, the loan is reviewed for specific impairment in accordance with the Company’s allowance for loan loss methodology. If it is determined that losses are probable on such TDRs, either because of delinquency or other credit quality indicators, the Company establishes specific reserves for these loans.
	Acquisition Accounting for Loans
	The Company accounts for business acquisitions in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 805, Business Combinations, which requires the use of the acquisition method of accounting. All identifiable assets acquired, including loans, are recorded at fair value. The fair value of loans that do not have deteriorated credit quality are accounted for in accordance with ASC 310-20, Nonrefundable Fees and Other Costs, and is represented by the expected cash flows from the portfolio discounted at current market rates. In estimating the cash flows, the Company makes assumptions about the amount and timing of principal and interest payments, estimated prepayments, estimated default rates, estimated loss severities in the event of defaults, and current market rates. The fair value adjustment is amortized over the life of the loan using the effective interest method. The Company accounts for certain acquired loans with deteriorated credit quality under ASC 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality. In accordance with ASC 310-30 and in estimating the fair value of loans with deteriorated credit quality as of the acquisition date, the Company: (a) calculates the contractual amount and timing of undiscounted principal and interest payments (the undiscounted contractual cash flows), and (b) estimates the amount and timing of undiscounted expected principal and interest payments (the undiscounted expected cash flows). The difference between the undiscounted contractual cash flows and the undiscounted expected cash flows is the nonaccretable difference. On the acquisition date, the amount by which the undiscounted expected cash flows exceed the estimated fair value of the loans with deteriorated credit quality is the accretable yield. The accretable yield is recorded into interest income over the estimated lives of the loans using the effective yield method. The accretable yield changes over time as actual and expected cash flows vary from the estimated cash flows at acquisition. Decreases in expected cash flows subsequent to acquisition result in recognition of a provision for loan loss. The accretable yield is measured at each financial reporting date and represents the difference between the remaining undiscounted expected cash flows and the current carrying value of the loans. The remaining undiscounted expected cash flows are calculated at each financial reporting date, based on information currently available. Increases in expected cash flows over those originally estimated increase the accretable yield and are recognized prospectively as interest income. Increases in expected cash flows may also lead to the reduction of any allowance for loan losses recorded after the acquisition. Decreases in expected cash flows compared to those originally estimated decrease the accretable yield and are recognized by recording an allowance for loan losses. As the accretable yield increases or decreases from changes in cash flow expectations, the offset is an increase or decrease to the nonaccretable difference. There is no carryover of allowance for loan losses, as the loans acquired are initially recorded at fair value as of the date of acquisition.
	Allowance for Loan Losses
	The allowance for loan losses represents an estimate that management believes will be adequate to absorb probable inherent losses on existing loans in its portfolio at the balance sheet date. The allowance is based on an evaluation of the collectability of loans and prior loss experience, including both industry and Company specific considerations. While management uses available information to make loan loss allowance evaluations, adjustments to the allowance may be necessary based on changes in economic and other conditions or changes in accounting guidance. See Note 6 for an analysis of the Company’s allowance for loan losses by portfolio and portfolio segment, and credit quality information by class.
	Management has an established methodology to determine the adequacy of the allowance for loan losses that assesses the risks and losses inherent in its portfolio and portfolio segments. The Company utilizes an internally developed model that requires significant judgment to determine the estimation method that fits the credit risk characteristics of the loans in its portfolio and portfolio segments. The allowance for loan losses is established through a provision for loan losses charged to expense. The adequacy of the allowance for loan losses is determined in accordance with generally accepted accounting principles.
	The Company’s loan portfolio is disaggregated into portfolio segments for purposes of determining the allowance for loan losses. The Company’s portfolio segments include commercial real estate, consumer real estate, commercial and industrial, and consumer loans. The Company further disaggregates the commercial and consumer real estate portfolio segments into classes for purposes of monitoring and assessing credit quality based on certain risk characteristics. Classes within each commercial real estate portfolio segment include commercial real estate construction and commercial real estate mortgage. Classes within each consumer real estate portfolio segment include consumer real estate construction and consumer real estate mortgage.
	Loans are charged off against the allowance for loan losses when management believes that the collectability of the principal is unlikely. The allowance for loan losses consists of specific and general reserves. The Company determines specific reserves based on the provisions of ASC 310, Receivables. The Company’s allowance for loan losses includes a measure of impairment for those loans specifically identified for evaluation under the topic. This measurement is based on a comparison of the recorded investment in the loan with either the expected cash flows discounted using the loan’s original contractual effective interest rate or the fair value of the collateral underlying certain collateral-dependent loans. Collectability of principal and interest is evaluated in assessing the need for a loss accrual. Loans identified as impaired are individually evaluated periodically for impairment.
	General reserves are based on management’s evaluation of many factors and reflect an estimated measurement of losses related to loans not individually evaluated for impairment. These loans are grouped into portfolio segments. The loss rates are derived from historical loss factors of the Company or the industry sustained on loans according to their risk grade, as well as qualitative and economic factors, and may be adjusted for Company-specific factors. Loss rates are reviewed quarterly and adjusted as management deems necessary based on changing borrower and/or collateral conditions and actual collections and charge-off experience.
	Based on observations made through a qualitative review, management may apply qualitative adjustments to the quantitatively determined loss estimates at a group and/or portfolio segment level as deemed appropriate. Primary qualitative and environmental factors that may not be directly reflected in quantitative estimates include:
		•		Asset quality trends
		•		Changes in lending policies
		•		Trends in the nature and volume of the loan portfolio, including the existence and effect of any portfolio concentrations
		•		Changes in experience and depth of lending staff
		•		National and regional economic trends
	Changes in these factors are considered in determining the directional consistency of changes in the allowance for loan losses. The impact of these factors on the Company’s qualitative assessment of the allowance for loan losses can change from period to period based on management’s assessment to the extent to which these factors are already reflected in historic loss rates. The uncertainty inherent in the estimation process is also considered in evaluating the allowance for loan losses.
	Off-Balance-Sheet
	Credit-Related Financial Instruments
	The Company accounts for its guarantees in accordance with the provisions of ASC 460, Guarantees. In the ordinary course of business, the Company has entered into commitments to extend credit, including commitments under credit card agreements, and standby letters of credit. Such financial instruments are recorded when they are funded.
	Derivative Financial Instruments
	ASC 815, Derivatives and Hedging, requires that all derivatives be recognized as assets or liabilities in the balance sheet at fair value. The Company may enter into derivative contracts to manage exposure to interest rate risk or meet the financing and/or investing needs of its customers.
	In the course of its business operations, the Company is exposed to certain risks, including interest rate, liquidity, and credit risk. The Company manages its risks through the use of derivative financial instruments, primarily through management of exposure due to the receipt or payment of future cash amounts based on interest rates. The Company’s derivative financial instruments manage the differences in the timing, amount, and duration of expected cash receipts and payments.
	Derivatives which are designated and qualify as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. The effective portion of the derivative’s gain or loss is initially reported as a component of other comprehensive income and subsequently reclassified into earnings when the forecasted transaction affects earnings or when the hedge is terminated. The ineffective portion of the gain or loss is reported in earnings immediately.
	In applying hedge accounting for derivatives, the Company establishes a method for assessing the effectiveness of the hedging derivative and a measurement approach for determining the ineffective aspect of the hedge upon the inception of the hedge. These methods are consistent with the Company’s approach to managing risk. The Company reports these net in the accompanying consolidated balance sheets when the Company has a master netting arrangement. As of December 31, 2013 there were no net amounts reported. Note 18 describes the derivative instruments currently used by the Company and discloses how these derivatives impact the Company’s financial position and results of operations.
Premises and Equipment
Land is carried at cost. Buildings, furniture, fixtures, and equipment are carried at cost, less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated life of each respective type of asset as follows:
Buildings		40 years
Furniture, fixtures, and equipment		5–15 years
Leasehold improvements are amortized using the straight-line method over the periods of the leases, including options expected to be exercised, or the estimated useful lives, whichever is shorter. Gains and losses on disposition and maintenance and repairs are included in current operations. Rental expense on leased property is recognized on a straight-line basis over the original lease term plus options that management expects to exercise. Fixed rental increases that are determinable are expensed over the lease period, including any option periods which are expected to be exercised, using a straight-line lease expense method.
Other Real Estate
Assets acquired through, or in lieu of, loan foreclosure are held for sale and are recorded at a new cost basis determined at the date of foreclosure as the lower of cost or fair value less estimated cost to sell. Cost is defined as the recorded investment in the loan. Subsequent to foreclosure, valuation allowances are established for any changes in the estimate of the asset’s fair value or selling costs, but not in excess of its new cost basis. Revenues and expenses from operations and changes in the valuation allowance are included in current earnings.
Goodwill and Other Intangible Assets
Goodwill is accounted for in accordance with ASC 350, Intangibles—Goodwill and Other, and, accordingly, is not amortized but is evaluated at least annually for impairment. As part of its annual impairment testing, the Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the Company determines the fair value of a reporting unit is less than its carrying amount using these qualitative factors, the Company compares the fair value of goodwill with its carrying amount, and then measures impairment loss by comparing the implied fair value of goodwill with the carrying amount of that goodwill.
Definite-lived intangible assets, which consist of core deposit intangibles, are amortized on a straight-line basis over their useful lives and evaluated at least annually for impairment.
Income Taxes
The Company accounts for income taxes under the liability method. Deferred tax assets and liabilities are established for the temporary differences between the financial reporting basis and the tax basis of the Company’s assets and liabilities using enacted tax rates expected to be in effect during the year in which the basis differences reverse.
The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires the Company to report information regarding its exposure to various tax positions taken by the Company. The Company has determined whether any tax positions have met the recognition threshold and has measured the Company’s exposure to those tax positions. Management believes that the Company has adequately addressed all relevant tax positions and that there are no unrecorded tax liabilities. Any interest or penalties assessed to the Company are recorded in operating expenses. No interest or penalties from any taxing authorities were recorded in the accompanying consolidated financial statements. Federal, state, and local taxing authorities generally have the right to examine and audit the previous three years of tax returns filed.
The Company is also required to reduce its tax basis of the investment in certain of the projects that generated the Federal NMTC or Federal Historic Rehabilitation tax credits by the amount of the credit generated in that year based on the taxable entity structure of the investee.
Noncontrolling Interests
During 2012, the $1.6 million of noncumulative, perpetual preferred stock held by unrelated parties of the Bank was redeemed and noncontrolling interests were reduced by that amount. The stock had been assumed by the Bank in a prior acquisition.
Noncontrolling interests also include $2,000, $1,000, and $2,000 at December 31, 2013, 2012, and 2011, respectively, of common stock held by unrelated parties in various tax credit-related subsidiaries, which have activities solely related to generating the tax credits.
Investments in Real Estate Properties
FNBC CDC invests in real estate properties, which are carried at cost. Costs of construction are capitalized during the construction period and do not include interest. The Company periodically obtains as-is appraisals to determine the recoverability of its investments for which it intends to sell. For properties the Company intends to hold, the Company assesses recoverability based on the cash flows of the underlying properties.
Investments in Tax Credit Entities
As part of its Community Reinvestment Act responsibilities and due to their favorable economics, the Company invests in tax credit-motivated projects primarily in the markets it serves. These projects are directed at tax credits issued under Low-Income Housing, Federal Historic Rehabilitation (Historic), and Federal New Markets Tax Credits. The Company generates its returns on tax credit motivated projects through the receipt of federal, and if applicable, state tax credits. The federal tax credits are recorded as an offset to the income tax provision in the year that they are earned under federal income tax law – over 10 to 15 years, beginning in the year in which rental activity commences for Low-Income Housing credits, or 10 years beginning in the year of the issuance of the certificate of occupancy for Historic credits, and over 7 years for Federal NMTC upon the investment of funds into the qualifying project. These credits, if not used in the tax return for the year of origination, can be carried forward for 20 years.
For Low-Income Housing and Historic credits, the Company invests in a tax credit entity, usually a limited liability company, which owns the real estate. The Company receives a 99.9% nonvoting interest in the entity that must be retained during the compliance period for the credits (15 years forLow-Income Housing credits and 5 years for Historic credits). In most cases, the Company’s interest in the entity is generally reduced from a 99.9% interest to a 10% to 25% interest at the end of the compliance period. Control of the tax credit entity rests in the 0.1% interest general partner, who has the power and authority to make decisions that impact economic performance of the project and is required to oversee and manage the project. Due to the lack of any voting, economic, or managerial control, and due to the contractual reduction in its investment, the Company accounts for its investment by amortizing its investment, beginning at the issuance of the certificate of occupancy of the project, over the compliance period, as management believes any potential residual value in the real estate will have limited value.
For Federal NMTC, a different structure is required by federal tax law. In order to distribute Federal NMTC, the federal government allocates such credits to CDEs. The Company invests in both CDEs formed by unaffiliated parties and in CDEs formed by the Company. Projects can be commercial or real estate operations and are qualified by their location in low- to moderate-income areas or by their employment of, or service to, low- to moderate-income citizens. A CDE, in most cases, creates a special-purpose subsidiary for the project through which the credits are allocated and through which the proceeds from the tax credit investor and a leverage lender, if applicable, flow through to the project, which in turn generate the credit. The credits are calculated at 39% of the total project cost at the rate of 5% for the first three years and 6% for the next four years. Federal tax law requires special terms benefitting the qualified project, which can include complete or partial debt forgiveness at the end of the seven-year term or below-market interest rates. The Company expenses the cost of any benefits provided to the project over the seven-year compliance period. When the Company also has a loan, commonly called a leveraged loan, to the project, it is carried in loans, as the Company has normal credit exposure to the project and is repaid at the end of the compliance period (in general, the debt has no principal payments during the compliance period but the Company, in most cases, requires the project to fund a sinking fund over the compliance period to achieve the same risk reduction effect as if principal is being amortized).
When the Company is the tax credit investor in a CDE formed by an unaffiliated party, it has no control of the applicable CDE, the CDE’s special-purpose subsidiary, or the qualified project entity. When a project is funded through FNBC CDE, the Company consolidates its CDE and the specifically formed special-purpose entities since it maintains control over these entities. As part of the activities of FNBC CDE, the Company makes investments in the CDE for purposes of providing equity to the projects sponsored by the FNBC CDE.
The Company has the risk of credit recapture if the project fails during the compliance period for Low-Income Housing and Historic transactions. For Federal NMTC transactions, the risk of credit recapture exists if investment requirements are not maintained during the compliance period. Such events, although rare, are accounted for when they occur, and no such events have occurred to date.
Variable Interest Entities
VIEs are entities that, in general, either do not have equity investors with voting rights or that have equity investors that do not provide sufficient financial resources for the entity to support its activities. The Company uses VIEs in various legal forms to conduct normal business activities. The Company reviews the structure and activities of VIEs for possible consolidation.
A controlling financial interest in a VIE is present when an enterprise has both the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits of the VIE that could potentially be significant to the VIE. A VIE often holds financial assets, including loans or receivables, real estate, or other property. The company with a controlling financial interest, known as the primary beneficiary, is required to consolidate the VIE. Noncontrolling variable interests in certain limited partnerships for which it does not absorb a majority of expected losses or receive a majority of expected residual returns that are not included in the accompanying consolidated financial statements. Refer to Notes 12 and 13 for further detail.
Stock-Based Compensation Plans
At December 31, 2013 and 2012, the Company had a stock-based employee compensation plan, which provides for the issuance of stock options and restricted stock. The Company accounts for stock-based employee compensation in accordance with the fair value recognition provisions of ASC 718, Compensation—Stock Compensation. Compensation cost is recognized as expense over the service period, which is generally the vesting period of the options and restricted stock. The expense is reduced for estimated forfeitures over the vesting period and adjusted for actual forfeitures as they occur. As a result, compensation cost for all share-based payments is reflected in net income as part of salaries and employee benefits in the accompanying consolidated statements of income. See Note 24 for additional information on the Company’s stock-based compensation plans.
Earnings Per Share
Basic earnings per common share is computed based upon net income attributable to common shareholders divided by the weighted-average number of common shares outstanding during each period. Diluted earnings per common share is computed based upon net income, adjusted for dilutive participating securities, divided by the weighted-average number of common shares outstanding during each period, and adjusted for the effect of dilutive potential common shares calculated using the treasury stock method and the assumed conversion for any dilutive convertible securities. In determining net income attributable to common shareholders, the net income attributable to participating securities is excluded. During 2011, the Company issued Series C preferred stock, which is considered a participating security because it shares in any dividends paid to common shareholders. The assumed conversion of the Series C preferred stock is excluded from the calculation of diluted earnings per share due to the fact that the shares are contingently issuable and the contingency still existed at the end of the year.
Comprehensive Income
Accounting principles generally require that recognized revenue, expenses, gains, and losses be included in net income. Although certain changes in assets and liabilities, such as unrealized gains and losses on available for sale securities and cash flow hedges, are reported as a separate component of the equity section of the balance sheet; such items, along with net income, are components of comprehensive income.
Segments
All of the Company’s banking operations are considered by management to be aggregated in one reportable operating segment. Because the overall banking operations comprise substantially all of the consolidated operations and none of the Company’s other subsidiaries, either individually or in the aggregate, meet quantitative materiality thresholds, no separate segment disclosures are presented in the accompanying consolidated financial statements.
Reclassifications
Certain reclassifications have been made to prior period balances to conform to the current period presentation. Investment in short-term receivables was previously reported within investment securities available for sale in prior period consolidated balance sheets, and the related income was previously reported in interest income from investment securities in prior period consolidated statements of income.
Recent Accounting Pronouncements
ASU No. 2011-11 and ASU No. 2013-01
In December 2011, the FASB issued ASU No. 2011-11, Balance Sheet (Topic 210): Disclosures about Offsetting Assets and Liabilities. ASU 2011-11 provides new accounting guidance that eliminates offsetting of financial instruments disclosure differences between GAAP and IFRS. ASU 2013-01, Balance Sheet (Topic 210): Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities, clarifies the scope of ASU No. 2011-11. New disclosures will be required for recognized financial instruments, such as derivatives, repurchase agreements, and reverse repurchase agreements, that are either: (a) offset on the balance sheet in accordance with the FASB’s offsetting guidance, or (b) subject to an enforceable master netting arrangement or similar agreement, regardless of whether they are offset in accordance with the FASB’s offsetting guidance. The objective of the new disclosure requirements is to enable users of the financial statements to evaluate the effect or potential effect of netting arrangements on an entity’s financial position, including the effect or potential effect of rights of setoff associated with certain financial instruments and derivative instruments. This amended guidance will be applied retrospectively and is effective for fiscal years, and interim periods within those years, beginning on or after January 1, 2013. The adoption of this guidance, which involves disclosure only, did not impact the Company’s results of operations or financial position. The Company currently does net its financial instruments on its consolidated balance sheets.
ASU No. 2012-06
In October 2012, the FASB issued ASU No. 2012-06, Business Combinations (Topic 805): Subsequent Accounting for an Indemnification Asset Recognized at the Acquisition Date as a Result of a Government-Assisted Acquisition of a Financial Institution, which clarifies the applicable guidance for subsequently measuring an indemnification asset recognized in a government-assisted acquisition of a financial institution that includes a loss-sharing agreement. The ASU addresses the diversity in practice in the interpretation of the terms “on the same basis” and “contractual limitations” used in accounting guidance. Accounting principles require that an indemnification asset recognized at the acquisition date as a result of a government-assisted acquisition of a financial institution involving an indemnification agreement shall be subsequently measured on the same basis as the indemnified item. The provisions of this ASU clarify that, upon subsequent remeasurement of an indemnification asset, the effect of the change in expected cash flows of the indemnification agreement shall be amortized. Any amortization of changes in value is limited to the lesser of the contractual term of the indemnification agreement and the remaining life of the indemnified assets. The ASU does not affect the guidance relating to the recognition or initial measurement of an indemnification asset. The amendments in this ASU are effective for fiscal years after December 15, 2012, with early adoption permitted. The Company does not have an indemnification asset recorded and therefore, the adoption of this ASU did not have a material impact on the Company’s results of operations, financial position, or disclosures.
ASU No. 2013-02
In February 2013, the FASB issued ASU No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income, which requires the Company to report the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in net income in the Company’s consolidated statement of comprehensive income if the amount being reclassified is required under U.S. GAAP to be reclassified in its entirety to net income. The ASU does not change the current requirements for reporting net income or other comprehensive income in the consolidated financial statements of the Company, but does require the Company to provide information about the amounts reclassified out of accumulated other comprehensive income by component. The provisions of the ASU are effective prospectively beginning after December 15, 2013, with early adoption permitted. The adoption of this ASU is reflected in the accompanying consolidated statements of comprehensive income.
ASU No. 2014-01
In January 2014, the FASB issued ASU No. 2014-01, Investments-Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Qualified Affordable Housing Projects, which permits reporting entities to make an accounting policy election to account for their investments in qualified affordable housing projects using the proportional amortization method if certain conditions are met. Under the proportional amortization method, an entity amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as a component of income tax expense (benefit). This ASU applies to all reporting entities that invest in qualified affordable housing projects through limited liability entities that are flow-through entities for tax purposes. The provisions of this ASU should be applied retrospectively to all periods presented for periods beginning after December 15, 2014, with early adoption permitted. The Company is evaluating the adoption of this ASU and has not determined the impact on the Company’s financial condition or results of operations.
ASU No. 2014-04
In January 2014, the FASB issued ASU No. 2014-04, Receivables-Troubled Debt Restructurings by Creditors (Subtopic 310-40): Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure, which clarifies when an insubstance repossession or foreclosure occurs, that is, when a creditor should be considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan such that the loan receivable should be derecognized and the real estate property recognized. The ASU requires a creditor to reclassify a collateralized consumer mortgage loan to real estate property upon obtaining legal title to the residential real estate property, or the borrower conveying all interest in the residential real estate property through completion of a deed in lieu of foreclosure or similar legal agreement. The provisions of this ASU are effective for all periods beginning after December 15, 2014.The adoption of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations.

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	2. Earnings Per Share
	The following sets forth the computation of basic net income per common share and diluted net income per common share:
		Year Ended December 31,
	(In thousands, except per share data)	2013		2012		2011
	Basic: Income available to common shareholders	$	40,564	$	28,430	$	18,068
	Less: Income attributable to participating securities (Series C preferred stock)		1,980		1,999		1,304
	Income attributable to common shareholders	$	38,584	$	26,431	$	16,764
	Weighted-average common shares outstanding		16,203,919		12,952,751		10,794,639
	Basic earnings per share	$	2.38	$	2.04	$	1.55
	Diluted: Income attributable to common shareholders	$	38,584	$	26,431	$	16,764
	Weighted-average common shares outstanding		16,203,919		12,952,751		10,794,639
	Effect of dilutive securities:
	Stock options outstanding		337,371		108,537		37,754
	Warrants		82,824		51,503		28,535
	Weighted-average common shares outstanding – assuming dilution		16,624,114		13,112,791		10,860,928
	Diluted earnings per share	$	2.32	$	2.02	$	1.54
	For the years ended December 31, 2012 and 2011, the calculations of diluted earnings per share outstanding exclude the effect from the assumed exercise of 87,059 shares of warrants outstanding, respectively. This amount would have had an antidilutive effect on earnings per share. For the year ended December 31, 2012, the calculation of diluted earnings per share outstanding also exclude the effect from the assumed exercise of 264,000 shares of stock options outstanding. These amounts would have had an antidilutive effect on earnings per share.

Cash_and_Due_From_Banks

Cash and Due From Banks	12 Months Ended
	Dec. 31, 2013
Cash And Cash Equivalents [Abstract]	'
Cash and Due From Banks	'
	3. Cash and Due From Banks
	The Company is required to maintain reserve requirements with the Federal Reserve Bank. The requirement is dependent upon the Bank’s cash on hand and transaction deposit account balances. The reserve requirements at December 31, 2013 and 2012, were $10.1 million and $8.2 million, respectively.

Investment_in_ShortTerm_Receiv

Investment in Short-Term Receivables	12 Months Ended
	Dec. 31, 2013
Receivables [Abstract]	'
Investment in Short-Term Receivables	'
	4. Investment in Short-Term Receivables
	The Company invests in short-term trade receivables purchased on an exchange, which are covered by a repurchase agreement from the seller of the receivables, if not paid within a specified period. Since the receivables are traded on an exchange, the Company has the ability to resell the receivables on the exchange. As of December 31, 2013 and 2012, the Company had $246.8 million and $81.0 million, respectively in purchased receivables.

Investment_Securities

Investment Securities	12 Months Ended
	Dec. 31, 2013
Investments Debt And Equity Securities [Abstract]	'
Investment Securities	'
	5. Investment Securities
	The amortized cost and market values of investment securities, with gross unrealized gains and losses, as of December 31, 2013 and December 31, 2012, were as follows (in thousands):
		Amortized			Gross		Gross Unrealized Losses						Estimated
		Cost			Unrealized								Market Value
					Gains		Less Than			Greater Than
							One Year			One Year
	December 31, 2013
	Available for sale:
	U.S. government agency securities	$	163,964		$	81	$	(10,991	)	$	(1,731	)	$	151,323
	U.S. Treasury securities		13,022			—		(873	)		—			12,149
	Municipal securities		23,240			140		(213	)		—			23,167
	Mortgage-backed securities		57,010			447		(1,897	)		(16	)		55,544
	Corporate bonds		37,023			395		(1,677	)		(205	)		35,536
		$	294,259		$	1,063	$	(15,651	)	$	(1,952	)	$	277,719
	Held to maturity:
	Municipal securities	$	44,294		$	94	$	(398	)	$	—		$	43,990
	Mortgage-backed securities		50,610			12		(3,646	)		—			46,976
		$	94,904		$	106	$	(4,044	)	$	—		$	90,966
	December 31, 2012
	Available for sale:
	U.S. government agency securities	$	128,665		$	83	$	(1	)	$	—		$	128,747
	U.S. Treasury securities		10,040			5		—			—			10,045
	Municipal securities		61,907			884		(44	)		—			62,747
	Mortgage-backed securities		152,481			1,615		(254	)		—			153,842
	Corporate bonds		49,912			410		(348	)		—			49,974
		$	403,005		$	2,997	$	(647	)	$	—		$	405,355
	During 2013, the Company transferred securities with a fair value of $95.4 million from available-for-sale to held to maturity. Management determined that it has both the positive intent and ability to hold these securities until maturity. The reclassified securities consisted of municipal and mortgage-backed securities and were transferred due to movements in interest rates. The securities were reclassified at fair value at the time of the transfer and represented a non-cash transaction. Accumulated other comprehensive income included pre-tax unrealized losses of $5.9 million on these securities at the date of the transfer. These unrealized losses and offsetting other comprehensive income components are being amortized into net interest income over the remaining life of the related securities as a yield adjustment, resulting in no impact on future net income.
	At December 31, 2013, the Company’s exposure to three investment security issuers individually exceeded 10% of shareholders’ equity (in thousands):
		Amortized			Estimated
		Cost			Market Value
	FHLB	$	83,052		$	78,729
	Federal National Mortgage Association (Fannie Mae)		81,693			75,421
	Federal Home Loan Mortgage Corporation (Freddie Mac)		62,281			57,860
		$	227,026		$	212,010
	As of December 31, 2013, the Company had 88 securities that were in a loss position. The unrealized losses for each of the 88 securities relate to market interest rate changes. The Company has considered the current market for the securities in a loss position, as well as the severity and duration of the impairments, and expects that the value will recover. As of December 31, 2013, management does not intend to sell these investments until the fair value exceeds amortized cost and it is more likely than not that the Company will not be required to sell debt securities before the anticipated recovery of the amortized cost basis of the security; thus, the impairment is determined not to be other-than-temporary.
	As of December 31, 2012, the Company had 39 securities that were in a loss position. The unrealized losses for each of the 39 securities relate to market interest rate changes. The Company has considered the current market for the securities in a loss position, as well as the severity and duration of the impairments, and expects that the value will recover. As of December 31, 2012, management had both the intent and ability to hold these investments until the fair value exceeds amortized cost; thus, the impairment is determined not to be other-than-temporary. In addition, management does not believe the Company will be required to sell debt securities before the anticipated recovery of the amortized cost basis of the security.
	The amortized cost and estimated market values by contractual maturity of investment securities as of December 31, 2013 and December 31, 2012 are shown in the following table (in thousands). Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.
		December 31, 2013								December 31, 2012
		Weighted			Amortized		Estimated			Weighted			Amortized		Estimated
		Average			Cost		Market Value			Average			Cost		Market Value
		Yield								Yield
	Available for sale:
	Due in one year or less		1.39	%	$	12,340	$	12,368			1.04	%	$	119,657	$	119,753
	Due after one year through five years		2.58			64,790		65,038			1.96			106,676		108,349
	Due after five years through ten years		2.12			180,362		168,243			2.36			130,396		130,958
	Due after ten years		3.17			36,767		32,070			2.6			46,276		46,295
	Total securities		2.3	%	$	294,259	$	277,719			1.67	%	$	403,005	$	405,355
	Held to maturity:
	Due in one year or less		1.76	%	$	1,007	$	1,007			—	%	$	—	$	—
	Due after one year through five years		2.6			18,101		17,539			—			—		—
	Due after five years through ten years		3.7			37,591		37,137			—			—		—
	Due after ten years		3.41			38,205		35,283			—			—		—
	Total securities		3.35	%	$	94,904	$	90,966			—	%	$	—	$	—
	Securities with estimated market values of $204.3 million and $121.4 million at December 31, 2013 and December 31, 2012, respectively, were pledged to secure public deposits, securities sold under agreements to repurchase, and long-term borrowings.
	Proceeds from sales of securities for the years ended December 31, 2013, 2012 and 2011 were $45.8 million, $125.4 million and $156.8 million, respectively. Gross gains of $0.5 million, $4.3 million, and $1.1 million were realized on these sales for the years ended December 31, 2013, 2012, and 2011, respectively. There were gross losses of $0.2 million for the year ended December 31, 2013, there were no gross losses for the year ended December 31, 2012, and gross losses of $0.6 million were realized for the year ended December 31, 2011.
	Other Equity Securities
	At December 31, 2013 and 2012, the Company included the following securities in other assets, at cost, in the accompanying consolidated balance sheets (in thousands):
		2013			2012
	FHLB stock	$	1,099		$	2,938
	First National Bankers Bankshares, Inc. (FNBB) stock		600			600
	Other investments		4,853			3,200
	Total equity securities	$	6,552		$	6,738

Loans

Loans	12 Months Ended
	Dec. 31, 2013
Receivables [Abstract]	'
Loans	'
	6. Loans
	Major classifications of loans at December 31, 2013 and December 31, 2012 were as follows (in thousands):
			December 31,			December 31,
			2013			2012
	Commercial real estate loans:
	Construction		$	203,369		$	159,999
	Mortgage(1)			1,118,048			983,164
				1,321,417			1,143,163
	Consumer real estate loans:
	Construction			8,986			7,738
	Mortgage			115,307			102,699
				124,293			110,437
	Commercial and industrial loans			868,469			622,105
	Loans to individuals, excluding real estate			16,345			14,000
	Nonaccrual loans			16,396			21,083
	Other loans			10,857			11,429
				2,357,777			1,922,217
	Less allowance for loan losses			(32,143	)		(26,977	)
	Loans, net		$	2,325,634		$	1,895,240
	(1)	Included in commercial real estate loans, mortgage, are owner-occupied real estate loans, of $364.9 million at December 31, 2013 and $345.4 million at December 31, 2012.
	A summary of changes in the allowance for loan losses during the years ended December 31, 2013, 2012, and 2011 is as follows (in thousands):
			2013			2012			2011
	Balance, beginning of period		$	26,977		$	18,122		$	12,508
	Provision charged to operations			9,800			11,035			8,010
	Charge-offs			(4,769	)		(2,561	)		(2,462	)
	Recoveries			135			381			66
	Balance, end of period		$	32,143		$	26,977		$	18,122
	Deferred costs less deferred fees, net of amortization, related to loan origination were $10.6 million and $9.0 million as of December 31, 2013 and 2012, respectively. These amounts are included in the loan balances above.
	In addition to loans issued in the normal course of business, the Company considers overdrafts on customer deposit accounts to be loans and reclassifies these overdrafts to loans in the accompanying consolidated balance sheets. At December 31, 2013 and 2012, overdrafts of $0.8 million had been reclassified to loans receivable.
	Loans were pledged to secure other borrowings at December 31, 2013 with carrying values of $655.1 million on a blanket lien and $29.4 million which were held in custody. At December 31, 2012, loans with carrying values of $481.8 million on a blanket lien and $49.9 million which were held in custody were pledged to secure other borrowings.
	The allowance for loan losses and recorded investment in loans, including loans acquired with deteriorated credit quality as of the dates indicated are as follows (in thousands):
			December 31, 2013
			Construction			Commercial			Consumer			Commercial			Other			Total
						Real Estate			Real Estate			and			Consumer
												Industrial
	Allowance for loan losses:
	Beginning balance		$	2,004		$	10,716		$	2,450		$	11,675		$	132		$	26,977
	Charge-offs			(46	)		(292	)		—			(4,229	)		(202	)		(4,769	)
	Recoveries			—			19			30			68			18			135
	Provision			832			3,337			176			5,163			292			9,800
	Ending balance		$	2,790		$	13,780		$	2,656		$	12,677		$	240		$	32,143
	Ending balances:
	Individually evaluated for impairment		$	42		$	1,639		$	183		$	2,091		$	—		$	3,955
	Collectively evaluated for impairment		$	2,748		$	12,141		$	2,473		$	10,586		$	240		$	28,188
	Loans receivable:
	Ending balance-total		$	212,430		$	1,128,181		$	117,653		$	883,111		$	16,402		$	2,357,777
	Ending balances:
	Individually evaluated for impairment		$	309		$	9,811		$	2,990		$	4,005		$	—		$	17,115
	Collectively evaluated for impairment		$	212,121		$	1,118,370		$	114,663		$	879,106		$	16,402		$	2,340,662
			December 31, 2012
			Construction			Commercial			Consumer			Commercial			Other			Total
						Real Estate			Real Estate			and			Consumer
												Industrial
	Allowance for loan losses:
	Beginning balance		$	722		$	9,871		$	1,519		$	5,928		$	82		$	18,122
	Charge-offs			—			(1,262	)		(59	)		(1,068	)		(172	)		(2,561	)
	Recoveries			16			132			22			153			58			381
	Provision			1,266			1,975			968			6,662			164			11,035
	Ending balance		$	2,004		$	10,716		$	2,450		$	11,675		$	132		$	26,977
	Ending balances:
	Individually evaluated for impairment		$	176		$	951		$	362		$	5,453		$	—		$	6,942
	Collectively evaluated for impairment		$	1,828		$	9,765		$	2,088		$	6,222		$	132		$	20,035
	Loans receivable:
Ending balance-total		$	168,544		$	988,994		$	103,516		$	647,090		$	14,073		$	1,922,217
Ending balances:
Individually evaluated for impairment		$	799		$	5,203		$	1,178		$	14,133		$	—		$	21,313
Collectively evaluated for impairment		$	167,745		$	983,791		$	102,338		$	632,957		$	14,073		$	1,900,904
Credit quality indicators on the Company’s loan portfolio, including loans acquired with deteriorated credit quality, as of the dates indicated were as follows (in thousands):
		December 31, 2013
		Pass and			Special			Substandard			Doubtful			Total
		Pass/Watch			Mention
Construction		$	197,951		$	4		$	14,475		$	—		$	212,430
Commercial real estate			1,073,339			1,720			53,122			—			1,128,181
Consumer real estate			113,037			185			4,431			—			117,653
Commercial and industrial			873,547			17			9,547			—			883,111
Other consumer			16,251			9			142			—			16,402
Total loans		$	2,274,125		$	1,935		$	81,717		$	—		$	2,357,777
		31-Dec-12
		Pass and			Special			Substandard			Doubtful			Total
		Pass/Watch			Mention
Construction		$	146,748		$	3,258		$	18,538		$	—		$	168,544
Commercial real estate			962,694			1,698			24,602			—			988,994
Consumer real estate			101,334			751			1,431			—			103,516
Commercial and industrial			620,851			18			14,984			11,237			647,090
Other consumer			13,859			13			201			—			14,073
Total loans		$	1,845,486		$	5,738		$	59,756		$	11,237		$	1,922,217
The table above as of December 31, 2013 includes $7.4 million of substandard loans and $1.6 million of special mention loans which are loans acquired with deteriorated credit quality. As of December 31, 2012, included in the above table was $8.9 million of substandard loans and $1.6 million of special mention loans which are loans acquired with deteriorated credit quality.
The above classifications follow regulatory guidelines and can generally be described as follows:
	•		Pass and pass/watch loans are of satisfactory quality.
	•		Special mention loans have an existing weakness that could cause future impairment, including the deterioration of financial ratios, past due status, questionable management capabilities, and possible reduction in the collateral values.
	•		Substandard loans have an existing specific and well-defined weakness that may include poor liquidity and deterioration of financial ratios. The loan may be past due and related deposit accounts may be experiencing overdrafts. Immediate corrective action is necessary.
	•		Doubtful loans have specific weaknesses that are severe enough to make collection or liquidation in full highly questionable and improbable.
Age analysis of past due loans, including loans acquired with deteriorated credit quality, as of the dates indicated were as follows (in thousands):
		December 31, 2013
		Greater Than			90 Days and			Total Past			Current Loans			Total Loans
		30 and Fewer			Greater			Due
		Than 90 Days			Past Due
		Past Due
Real estate loans:
Construction		$	15		$	75		$	90		$	212,340		$	212,430
Commercial real estate			2,935			7,642			10,577			1,117,604			1,128,181
Consumer real estate			1,260			2,166			3,426			114,227			117,653
Total real estate loans			4,210			9,883			14,093			1,444,171			1,458,264
Other loans:
Commercial and industrial			3,076			1,281			4,357			878,754			883,111
Other consumer			488			207			695			15,707			16,402
Total other loans			3,564			1,488			5,052			894,461			899,513
Total loans		$	7,774		$	11,371		$	19,145		$	2,338,632		$	2,357,777
		31-Dec-12
		Greater Than			90 Days and			Total Past			Current Loans			Total Loans
		30 and Fewer			Greater			Due
		Than 90 Days			Past Due
		Past Due
Real estate loans:
Construction		$	—		$	751		$	751		$	167,793		$	168,544
Commercial real estate			960			5,914			6,874			982,120			988,994
Consumer real estate			483			651			1,134			102,382			103,516
Total real estate loans			1,443			7,316			8,759			1,252,295			1,261,054
Other loans:
Commercial and industrial			671			2,197			2,868			644,222			647,090
Other consumer			25			54			79			13,994			14,073
Total other loans			696			2,251			2,947			658,216			661,163
Total loans		$	2,139		$	9,567		$	11,706		$	1,910,511		$	1,922,217
The table above includes $0.4 million of other consumer loans past due greater than 30 and fewer than 90 days, and $0.2 million of other consumer loans 90 days and greater past due, as of December 31, 2013. These loans are cash secured and the Company has rights of offset against the guarantors’ deposit accounts when the loans are 120 days past due.
The following is a summary of information pertaining to impaired loans, which consist primarily of nonaccrual loans. This table excludes loans acquired with deteriorated credit quality. Acquired impaired loans are generally not subject to individual evaluation for impairment and are not reported with impaired loans or troubled debt restructurings, even if they would otherwise qualify for such treatment. Impaired loans as of the periods indicated were as follows (in thousands):
		December 31, 2013
		Recorded			Contractual			Related			Average			Interest
		Investment			Balance			Allowance			Recorded			Income
											Investment			Recognized
With no related allowance recorded:
Construction		$	—		$	—		$	—		$	24		$	—
Commercial real estate			4,261			4,469			—			3,063			110
Consumer real estate			1,973			1,999			—			1,254			—
Commercial and industrial			1,099			1,116			—			977			40
Total		$	7,333		$	7,584		$	—		$	5,318		$	150
With an allowance recorded:
Construction		$	309		$	309		$	42		$	530		$	23
Commercial real estate			5,550			7,428			1,639			4,445			59
Consumer real estate			1,017			1,046			183			831			21
Commercial and industrial			2,906			2,941			2,091			8,093			10
Total		$	9,782		$	11,724		$	3,955		$	13,899		$	113
Total impaired loans:
Construction		$	309		$	309		$	42		$	554		$	23
Commercial real estate			9,811			11,897			1,639			7,508			169
Consumer real estate			2,990			3,045			183			2,085			21
Commercial and industrial			4,005			4,057			2,091			9,070			50
Total		$	17,115		$	19,308		$	3,955		$	19,217		$	263
		December 31, 2012
		Recorded			Contractual			Related			Average			Interest
		Investment			Balance			Allowance			Recorded			Income
											Investment			Recognized
With no related allowance recorded:
Construction		$	48		$	48		$	—		$	1,146		$	3
Commercial real estate			1,864			1,984			—			2,478			30
Consumer real estate			534			534			—			639			2
Commercial and industrial			854			874			—			1,030			54
Total		$	3,300		$	3,440		$	—		$	5,293		$	89
With an allowance recorded:
Construction		$	751		$	751		$	176		$	376		$	14
Commercial real estate			3,339			3,367			548			1,855			47
Consumer real estate			644			644			765			819			9
Commercial and industrial			13,279			13,280			5,453			6,781			389
Total		$	18,013		$	18,042		$	6,942		$	9,831		$	459
Total impaired loans:
Construction		$	799		$	799		$	176		$	1,522		$	17
Commercial real estate			5,203			5,351			548			4,333			77
Consumer real estate			1,178			1,178			765			1,458			11
Commercial and industrial			14,133			14,154			5,453			7,811			443
Total		$	21,313		$	21,482		$	6,942		$	15,124		$	548
Also presented in the above table is the average recorded investment of the impaired loans and the related amount of interest recognized during the time within the period that the impaired loans were impaired. When the ultimate collectability of the total principal of an impaired loan is in doubt and the loan is on nonaccrual status, all payments are applied to principal under the cost recovery method. When the ultimate collectability of the total principal of an impaired loan is not in doubt and the loan is in nonaccrual status, contractual interest is credited to interest income when received under the cash basis method. In the table above, all interest recognized represents cash collected. The average balances are calculated based on the month-end balances of the financing receivables of the period reported.
As of December 31, 2013, there were $0.2 million in cash secured tuition loans which were past due 90 days or more that were still accruing interest and there were no loans past due 90 days or more that were still accruing interest as of December 31, 2012.
A summary of information pertaining to nonaccrual loans as of the periods indicated is as follows (in thousands):
		2013			2012
Nonaccrual loans:
Construction		$	75		$	806
Commercial real estate			10,133			5,831
Consumer real estate			2,347			818
Commercial and industrial			3,784			13,556
Other consumer			57			72
		$	16,396		$	21,083
As of December 31, 2013 and December 31, 2012, the average recorded investment in nonaccrual loans was $17.9 million and $8.2 million, respectively. The amount of interest income that would have been recognized on nonaccrual loans based on contractual terms was $1.0 million and $0.4 million at December 31, 2013 and December 31, 2012, respectively. As of December 31, 2013, the Company was not committed to lend additional funds to any customer whose loan was classified as impaired.
ASC 310-30 Loans
The Company acquired certain loans from the Federal Deposit Insurance Corporation, as receiver for Central Progressive Bank, that are subject to ASC 310-30. ASC 310-30 provides recognition, measurement, and disclosure requirements for acquired loans that have evidence of deterioration of credit quality since origination for which it is probable, at acquisition, that the Company will be unable to collect all contractual amounts owed. The Company’s allowance for loan losses for all acquired loans subject to ASC 310-30 would reflect only those losses incurred after acquisition.
The following is a summary of changes in the accretable yields of acquired loans as of the years ended December 31, 2013 and 2012 (in thousands):
		2013			2012
Balance, beginning of period		$	628		$	1,374
Acquisition			—			—
Net transfers from nonaccretable difference to accretable yield			45			361
Accretion			(503	)		(1,107	)
Balance, end of period		$	170		$	628
Information about the Company’s TDRs as of December 31, 2013 and December 31, 2012, is presented in the following tables (in thousands):
Year Ended December 31, 2013		Current			Greater			Nonaccrual			Total Loans
					Than 30			TDRs
					Days Past
					Due
Real estate loans:
Construction		$	309		$	—		$	—		$	309
Commercial real estate			357			—			102			459
Consumer real estate			625			—			136			761
Total real estate loans			1,291			—			238			1,529
Other loans:
Commercial and industrial			337			—			—			337
Total loans		$	1,628		$	—		$	238		$	1,866
Year Ended December 31, 2012
Real estate loans:
Construction		$	47		$	—		$	—		$	47
Commercial real estate			268			—			982			1,250
Consumer real estate			655			—			—			655
Total real estate loans			970			—			982			1,952
Other loans:
Commercial and industrial			384			—			—			384
Total loans		$	1,354		$	—		$	982		$	2,336
The following table provides information on how the TDRs were modified during the years ended December 31, 2013 and 2012 (in thousands):
		2013			2012
Maturity and interest rate adjustment		$	925		$	609
Movement to or extension of interest rate-only payments			597			1,333
Other concession(s)(1)			344			394
Total		$	1,866		$	2,336
-1	Other concessions include concessions or a combination of concessions, other than maturity extensions and interest rate adjustments.
A summary of information pertaining to modified terms of loans, as of the dates indicated, is as follows (in thousands):
		December 31, 2013
		Number of			Pre-			Post-
		Contracts			Modification			Modification
					Outstanding			Outstanding
					Recorded			Recorded
					Investment			Investment
Troubled debt restructuring:
Construction			2		$	309		$	309
Commercial real estate			3			459			459
Consumer real estate			3			761			761
Commercial and industrial			1			337			337
			9		$	1,866		$	1,866
		31-Dec-12
		Number of			Pre-Modification			Post-
		Contracts			Outstanding			Modification
					Recorded			Outstanding
					Investment			Recorded
								Investment
Troubled debt restructuring:
Construction			1		$	47		$	47
Commercial real estate			2			1,250			1,250
Consumer real estate			3			655			655
Commercial and industrial			1			384			384
			7		$	2,336		$	2,336
None of the performing TDRs defaulted subsequent to the restructuring through the date the financial statements were available to be issued.
As of December 31, 2013 and 2012, the Company was not committed to lend additional funds to any customer whose loan was classified as impaired or as a TDR.

Transfers_and_Servicing_of_Fin

Transfers and Servicing of Financial Assets	12 Months Ended
	Dec. 31, 2013
Transfers And Servicing [Abstract]	'
Transfers and Servicing of Financial Assets	'
	7. Transfers and Servicing of Financial Assets
	Loans serviced for others, consisting primarily of commercial loan participations sold, are not included in the accompanying consolidated balance sheets. The unpaid principal balances of loans serviced for others were $28.0 million and $40.6 million at December 31, 2013 and 2012, respectively.

Premises_and_Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2013
Property Plant And Equipment [Abstract]	'
Premises and Equipment	'
	8. Premises and Equipment
	Premises and equipment consisted of the following at December 31 (in thousands):
		2013		2012
	Buildings and leasehold improvements	$	35,765	$	30,716
	Land		10,399		8,940
	Furniture, fixtures, and equipment		13,773		11,536
	Construction in progress		1,542		3,475
	Total premises and equipment		61,479		54,667
	Less accumulated depreciation and amortization		10,305		7,600
	Total premises and equipment, net	$	51,174	$	47,067
	The Company recorded depreciation of $2.7 million for each of the years ended December 31, 2013 and 2012, and $1.7 million for the year ended December 31, 2011.

Other_Real_Estate_Owned

Other Real Estate Owned	12 Months Ended
	Dec. 31, 2013
Banking And Thrift [Abstract]	'
Other Real Estate Owned	'
	9. Other Real Estate Owned
	At December 31, 2013 and 2012, the Company had other real estate owned of $3.7 million and $8.6 million, respectively, from real estate acquired by foreclosure.

Goodwill_and_Other_Acquired_In

Goodwill and Other Acquired Intangible Assets	12 Months Ended
	Dec. 31, 2013
Goodwill And Intangible Assets Disclosure [Abstract]	'
Goodwill and Other Acquired Intangible Assets	'
	10. Goodwill and Other Acquired Intangible Assets
	Changes to the carrying amount of goodwill for the years ended December 31, 2013 and 2012 are provided in the following table (in thousands):
	Balance at December 31, 2011	$	4,808
	Goodwill acquired during the year		—
	Balance at December 31, 2012		4,808
	Goodwill acquired during the year		—
	Balance at December 31, 2013	$	4,808
	The Company performs an annual impairment test of goodwill as of October 1, or more often if indicators or conditions are present which require an assessment. The results of this test did not indicate impairment of the Company’s recorded goodwill.
	At December 31, 2013 and 2012, the Company reported core deposit intangibles totaling $3.5 million and $3.8 million, net of accumulated amortization of $0.9 million and $0.6 million, respectively. The Company’s core deposit intangibles are being amortized over the estimated useful life of 12 years. The Company’s annual amortization expense totaled $0.2 million for each of the years ended December 31, 2013 and 2012. There was $0.4 million of amortization expense for the year ended December 31, 2011.
	The estimated amortization expense for the core deposit intangible asset is as follows as of December 31, 2013 (in thousands):
	2014-2018	$	376
	2019 and thereafter		2,272

Investments_in_Real_Estate_Pro

Investments in Real Estate Properties	12 Months Ended
	Dec. 31, 2013
Real Estate [Abstract]	'
Investments in Real Estate Properties	'
	11. Investments in Real Estate Properties
	During 2013 and 2012, the FNBC CDC purchased various affordable residential real estate properties in the New Orleans area for the purpose of making improvements to these properties and selling the properties. The Company’s cost basis (including the cost of improvements) in these residential real estate properties totaled $10.1 million and $6.9 million at December 31, 2013 and 2012, respectively. During the years ended December 31, 2013, 2012, and 2011, the Company capitalized costs of $5.0 million, $0.9 million, and $1.0 million, respectively.

Investments_in_Tax_Credit_Enti

Investments in Tax Credit Entities	12 Months Ended
	Dec. 31, 2013
Schedule Of Investments [Abstract]	'
Investments in Tax Credit Entities	'
	12. Investments in Tax Credit Entities
	Federal NMTC
	Investment in Bank Owned CDE
	During 2013, FNBC CDE received an allocation of Federal NMTC, totaling $50 million, which will generate $19.5 million in tax credits. During 2012 and 2011, FNBC CDE received allocations of $40 million and $28 million, respectively, which are expected to generate $15.6 million and $10.9 million, respectively in tax credits. First NBC has received $118 million in cummulative awards. The Federal NMTC program is administered by the Community Development Financial Institutions Fund of the U.S. Treasury and is aimed at stimulating economic and community development and job creation in low-income communities. The program provides federal tax credits to investors who make qualified equity investments (QEIs) in a CDE. The CDE is required to invest the proceeds of each QEI in projects located in or benefitting low-income communities, which are generally defined as those census tracts with poverty rates greater than 20% and/or median family incomes that are less than or equal to 80% of the area’s median family income.
	The credit provided to the investor totals 39% of each QEI in a CDE and is claimed over a seven-year credit allowance period. In each of the first three years, the investor receives a credit equal to 5% of the total QEI amount invested in the project. For each of the remaining four years, the investor receives a credit equal to 6% of the total QEI amount invested in the project. The Company will be eligible to receive up to $46 million in tax credits over the seven-year credit allowance period, based on the period in which the QEI was made, for its QEI of $118 million. Through December 31, 2013, FNBC CDE has invested in allocations of $118 million, of which $32.6 million of the 2013 award and $22.5 million of the 2012 and 2011 awards was invested by the Company and $62.9 million was invested by other investors and leverage lenders, which include the Company. These investments generated total Federal NMTC of approximately $46.0 million, of which $10.4 million has been recognized by the Company through December 31, 2013 and $35.6 million remains available to be earned over six years beginning in 2014, subject to continuing compliance with applicable regulations. The Federal NMTCs claimed by the Company, with respect to each QEI, remain subject to recapture over each QEI’s credit allowance period upon the occurrence of any of the following:
		•	FNBC CDE does not invest substantially all (generally defined as 85%) of the QEI proceeds in qualified low income community investments;
		•	FNBC CDE ceases to be a CDE; or
		•	FNBC CDE redeems its QEI investment prior to the end of the current credit allowance period.
	At December 31, 2013 and December 31, 2012, none of the above recapture events had occurred, nor, in the opinion of management, are such events anticipated to occur in the foreseeable future. As of December 31, 2013, FNBC CDE had total assets of $68.7 million, consisting of cash of $27.9 million, loans of $40.7 million and other assets of $0.1 million, with liabilities of $0.1 million and capital of $68.6 million.
	Investments through Non-Bank Owned CDEs
	The Company is also a limited partner in several tax-advantaged limited partnerships whose purpose is to invest in approved Federal NMTC and state projects that are CDEs and that are not associated with FNBC CDE. During 2013, several of these partnerships that the company was a limited partner in converted to a C corporation. The Company’s ownership in the CDEs did not change based on the conversion. These investments are accounted for using the cost method of accounting and are included in investment in tax credit entities in the accompanying consolidated balance sheets. The limited partnerships and C corporations are considered VIEs. The VIEs have not been consolidated because the Company is not considered the primary beneficiary. All of the Company’s investments in Federal NMTC structures are privately held, and their market values are not readily determinable. At December 31, 2013, the Company had $61.2 million invested in state and federal partnerships and C corporations. These investments generated Federal NMTC of approximately $60.6 million, of which $27.2 million had been recognized by the Company through December 31, 2013 and $33.4 million is expected to be recognized in periods after 2013. Based on the structure of these transactions, the Company expects to recover its investment totaling $61.2 million solely through use of the tax credits that were generated by the investments. As such, these amounts will be amortized on a straight-line basis over the period over which the Company holds its investment (approximately seven years). The Company also made loans unrelated to the generation and use of tax credits related to these real estate projects totaling $81.8 million and $64.1 million at December 31, 2013 and December 31, 2012, respectively. These loans are subject to the Company’s normal underwriting criteria and all loans were performing according to their contractual term at December 31, 2013.
	Low-Income Housing Tax Credits
	The Company is a limited partner in several tax-advantaged limited partnerships whose purpose is to invest in approved Low-Income Housing Tax Credit projects. These investments are accounted for using the cost method of accounting and are included in investments in tax credit entities in the accompanying consolidated balance sheets. The limited partnerships are considered to be VIEs. The VIEs have not been consolidated because the Company is not considered the primary beneficiary. All of the Company’s investments in low-income housing partnerships are evaluated for impairment at the end of each reporting period. At December 31, 2013 and December 31, 2012, the Company had $40.0 million and $25.3 million, respectively, invested in these partnerships which generated Low-Income Housing Tax Credits of approximately $57.0 million. Of that amount, $9.5 million had been recognized through December 31, 2013 and $47.4 million is expected to be recognized in periods beginning in 2014. Based on the structure of these transactions, the Company expects to recover its remaining investments of $40.0 million at December 31, 2013, solely through use of the tax credits that were generated by the investments. As such, this amount will be amortized on a straight-line basis over the period for which the Company maintains its 99.9% interest in the property (approximately 15 years). The Company also made loans unrelated to the generation and use of tax credits related to these real estate projects totaling $42.0 million at December 31, 2013 and December 31, 2012. These loans are subject to the Company’s normal underwriting criteria and all loans were performing according to their contractual terms at December 31, 2013.
	Federal Historic Rehabilitation Tax Credits
	The Company is a limited partner in several tax-advantaged limited partnerships whose purpose is to invest in approved Historic Tax Credit projects. These investments are accounted for using the cost method of accounting and are included in investments in tax credit entities in the accompanying consolidated balance sheets. The limited partnerships are considered to be VIEs. The VIEs have not been consolidated because the Company is not considered the primary beneficiary. All of the Company’s investments in limited partnerships are evaluated for impairment at the end of each reporting period. At December 31, 2013 and December 31, 2012, the Company had $16.5 million and $7.1 million, respectively, invested in these partnerships. These investments generated Historic Tax Credits of $25.7 million. Of that amount, $17.8 million had been recognized through December 31, 2013 and $7.5 million is expected to be recognized in 2014. The Company did not make any loans related to these real estate projects. Based on the structure of these transactions, the Company expects to recover its investments totaling $16.5 million at December 31, 2013 solely through use of the tax credits that were generated by the investments. As such, these amounts will be amortized on a straight-line basis over the period during which the Company retains its 99.9% interest in the property (approximately 10 years).

Variable_Interest_Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2013
Text Block [Abstract]	'
Variable Interest Entities	'
	13. Variable Interest Entities
	During 2013, the Company entered into a loan workout arrangement with a borrower. Due to this workout arrangement, this is considered to be a VIE, whereby the Company is considered the primary beneficiary and must consolidate the VIE. The initial recognition of this VIE relationship was accounted for using acquisition accounting. Under acquisition accounting, the assets and liabilities acquired are accounted for at market and intercompany balances are eliminated. The asset acquired from the debtor, which consisted of a net operating loss, is included in the accompanying consolidated balance sheets.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2013
Banking And Thrift [Abstract]	'
Deposits	'
	14. Deposits
	Interest-bearing deposits at December 31, 2013 and 2012 consisted of the following (in thousands):
		2013		2012
	Savings	$	53,779	$	45,295
	Money market accounts		655,173		410,928
	Negotiable order of withdrawal (NOW) accounts		511,620		437,542
	Certificates of deposit over $100,000		820,374		698,007
	Certificates of deposit under $100,000		398,781		437,218
		$	2,439,727	$	2,028,990
	The certificates of deposit mature as follows as of December 31, 2013 (in thousands):
	2014	$	550,700
	2015		282,427
	2016		194,253
	2017		74,821
	2018		115,839
	Thereafter		1,115
		$	1,219,155

ShortTerm_Borrowings

Short-Term Borrowings	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Short-Term Borrowings	'
	15. Short-Term Borrowings
	The following is a summary of short-term borrowings at December 31 (in thousands):
		2013		2012
	FNBB	$	8,425	$	21,800
	Total short-term borrowings	$	8,425	$	21,800
	The short-term borrowings at December 31, 2013 and 2012, consisted of federal funds purchased with a maturity of one day and an interest rate of 0.95%, respectively. These borrowings were repaid in January 2014 and 2013, respectively.
	The following is a summary of unused lines of credit at December 31 (in thousands):
		2013		2012
	FNBB	$	30,000	$	30,000
	JPMorgan Chase		30,000		30,000
	FHLB		432,181		338,032
	PNC Bank		15,000		15,000
	Comerica		20,000		—
	Total unused lines of credit	$	527,181	$	413,032
	The FHLB line of credit at December 31, 2013 is subject to a blanket pledge of $655.1 million of real estate loans and a custody pledge of $29.4 million of real estate loans. The FHLB line of credit at December 31, 2012 was subject to a blanket pledge of $481.8 million of real estate loans and a custody pledge of $49.9 million of real estate loans.

LongTerm_Borrowings

Long-Term Borrowings	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Long-Term Borrowings	'
	16. Long-Term Borrowings
	The following is a summary of long-term borrowings at December 31 (in thousands):
		2013		2012
	FNBB	$	110	$	220
	Credit Suisse Securities (USA) LLC		55,000		55,000
	Comerica		—		20,000
	Total long-term borrowings	$	55,110	$	75,220
	Long-term borrowings from FNBB consist of borrowings by the Employee Stock Ownership Trust in order to purchase 50,000 shares of Company stock for $550,000 on December 31, 2009. These borrowings are required to be recorded on the Company’s balance sheet, with an offsetting entry to additional paid-in capital. These borrowings mature on December 22, 2014, and bear interest at a floating rate equal to the Wall Street Journal Prime rate, which was 3.25% at December 31, 2013 and 2012. These borrowings are subject to a pledge of 10,000 and 20,000 shares of the Company stock, owned by the Trust, at December 31, 2013 and 2012, respectively.
	Long-term borrowings from Credit Suisse consist of two borrowings by the Company, which are in the legal form of a long-term repurchase agreement. A $15 million borrowing matures on October 19, 2014, and bears interest at a floating rate equal to 2.03% minus the greater of 3-month USD LIBOR less 1.50% or 0%, and was 2.03% at December 31, 2013 and 2012. A $40 million borrowing matures on June 21, 2015, and bears interest at a floating rate equal to 2.83% minus the greater of three-month USD LIBOR less 2.00% or 0%, and was 2.83% at December 31, 2013. These borrowings are subject to a pledge of mortgage-backed securities with a market value of $67.0 million and $73.8 million at December 31, 2013 and 2012, respectively.
	During 2013, the long-term borrowings from Comerica were paid.
	Principal payments by year on these borrowings are as follows (in thousands):
	2014	$	15,110
	2015		40,000
	Total long-term borrowings	$	55,110

Repurchase_Agreements

Repurchase Agreements	12 Months Ended
	Dec. 31, 2013
Text Block [Abstract]	'
Repurchase Agreements	'
	17. Repurchase Agreements
	Securities sold under agreements to repurchase, which are classified as secured borrowings, generally mature one day after the transaction date. Securities sold under agreements to repurchase are reflected at the amount of cash received in connection with the transaction. The Company may be required to provide additional collateral based on the fair value of the underlying securities. The carrying value of the securities pledged as collateral for the repurchase agreements was $92.7 million and $32.7 million at December 31, 2013 and 2012, respectively.

Derivative_Interest_Rate_Swap_

Derivative - Interest Rate Swap Agreements	12 Months Ended
	Dec. 31, 2013
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'
Derivative - Interest Rate Swap Agreements	'
	18. Derivative - Interest Rate Swap Agreements
	During 2013, the Company entered into a delayed interest rate swap to manage exposure against the variability in the expected future cash flows attributed to changes in the benchmark interest rate on a portion of its variable-rate debt. The Company entered this interest rate swap agreement to convert a portion of its variable- rate debt to a fixed rate, which is a cash flow hedge of a forecasted transaction. The total notional amount of the derivative contract is $150 million. The Company will receive payments from the counterparty at three-month LIBOR and make payments to the counterparty at a fixed rate of 4.165% on the notional amount. The cash flow payments on the derivative begin December 2016 and terminate September 2023.
	Also, in 2013, the Company entered into four interest rate swaps to manage exposure against the variability in the expected future cash flows on the designated Prime, Prime plus 1%, Prime plus 1% floored at 5% and Prime plus 1% floored at 5.5% pools of its floating rate loan portfolio. The Company entered into the interest rate swap agreements to hedge the cash flows from these pools of its floating rate loan portfolio, which is expected to offset the variability in the expected future cash flows attributable to the fluctuations in the daily weighted average Wall Street Journal Prime index, which is a cash flow hedge of a forecasted transaction. The notional amount of the contracts are Prime tranche of $30 million, Prime plus 1% tranche of $40 million, Prime plus 1% floored at 5% of $100 million, and Prime plus 1% floored at 5.5% tranche of $80 million for a total notional of $250 million. The Company will receive payments from the counterparty at a fixed rate of interest and pay the counterparty at the Prime rate associated with each tranche on its notional amount. The Prime tranche will receive payments at a fixed rate of 4.70% and pay the counterparty at Prime on the notional amount. The Prime plus 1% tranche will receive payments at a fixed rate of 5.70% and pay the counterparty at Prime plus 1% on the notional amount. The Prime plus 1% floored at 5% tranche will receive payments at a fixed rate of 6.01% and pay the counterparty at Prime plus 1%, floored at 5% on the notional amount. The Prime plus 1% floored at 5.5% tranche will receive payments at a fixed rate of 6.26% and pay the counterparty at Prime plus 1% floored at 5.5% on the notional amount. The cash flow payments on the derivatives began September 2013 and terminate September 2019.
	For the year ended December 31, 2013 a loss of $2.8 million (net of income taxes) has been recognized on the prime hedges and delayed interest rate swaps in other comprehensive income. The fair value of the derivative liabilities were $2.0 million for the delayed interest rate swap and $2.3 million for the prime swaps as of December 31, 2013 and have been recognized in other liabilities in the accompanying consolidated balance sheets. No amounts of gains or losses have been reclassified from accumulated comprehensive income nor have any amounts of gains or losses been recognized due to ineffectiveness of a portion of the derivative.
	Pursuant to the interest rate swap agreement, described above, the Company pledged collateral to the counterparties in the form of investment securities totaling $9.6 million (with a fair value at December 31, 2013 of $9.6 million), which has been presented gross in the Company’s consolidated balance sheet.
	During 2012, as part of its activities to manage interest rate risk due to interest rate movements, the Company entered into a delayed interest rate swap to manage exposure to future interest rate risk through modification of the Company’s net interest sensitivity to levels deemed to be appropriate. The Company entered this interest rate swap agreement to convert a portion of its forecasted variable-rate debt to a fixed rate, which is a cash flow hedge of a forecasted transaction. The notional amount in the derivative contract is $115 million. The Company will receive payments from the counterparty at three-month LIBOR and make payments to the counterparty at a fixed rate on 2.88% on the notional amount. The cash flow payments on the derivative begin January 2015 and terminate January 2022.
	Because the swap agreement used to manage interest rate risk has been designated as hedging exposure to variable cash flows of a forecasted transaction, the effective portion of the derivative’s gain or loss is initially reported as a component of other comprehensive income and subsequently reclassified into earnings when the forecasted transaction affects earnings or when the hedge is terminated. The ineffective portion of the gain or loss is reported in earnings immediately.
	In applying hedge accounting for derivatives the Company establishes a method for assessing the effectiveness of the hedging derivative by utilizing the dollar offset approach and a measurement approach for determining the ineffective aspect of the hedge through the variable cash flows methods upon the inception of the hedge. These methods are consistent with Company’s approach to managing risk.
	For interest rate swap agreements that are not designated as hedging instruments, changes in the fair value of the derivatives are recognized in earnings immediately.
	For the years ended December 31, 2013 and 2012, respectively, the Company has not reclassified into earnings any gain or loss as a result of the discontinuance of cash flow hedges because it was probable the original forecasted transaction would not occur by the end of the originally specified term.
	At December 31, 2013, no amount of the derivative will mature within the next 12 months. The Company does not expect to reclassify any amount from accumulated other comprehensive income into interest income over the next 12 months for derivatives that will be settled.
	For the year ended December 31, 2013 a gain of $5.2 million (net of income taxes) has been recognized in other comprehensive income and for the year ended December 31, 2012 a loss of $4.5 million (net of income taxes) has been recognized in other comprehensive income. The fair value of the derivative asset of $1.2 million as of December 31, 2013 has been recognized in other assets in the accompanying consolidated balance sheets. The fair value of the derivative liability of $6.9 million as of December 31, 2012 has been recognized in other liabilities in the accompanying consolidated balance sheets. No amounts of gains or losses have been reclassified from accumulated comprehensive income nor have any amounts of gains or losses been recognized due to ineffectiveness of a portion of the derivative.
	Pursuant to the interest rate swap agreement, entered into in 2012, the Company pledged collateral to the counterparties in the form of investment securities totaling $12.7 million (with a fair value at December 31, 2013 of $12.1 million), which has been presented gross in the Company’s balance sheet. There was no collateral posted from the counterparties to the Company as of December 31, 2013.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	19. Income Taxes
	The income tax benefit on the income from operations for the years ended December 31, 2013, 2012, and 2011 was as follows (in thousands):
		2013			2012			2011
	Current tax expense	$	186		$	—		$	—
	Deferred tax benefit		(19,937	)		(7,565	)		(5,407	)
	Total tax benefit	$	(19,751	)	$	(7,565	)	$	(5,407	)
	The amount of taxes in the accompanying consolidated statements of income is different from the expected amount using statutory federal income tax rates primarily due to the effect of various tax credits.
		Year Ended December 31,
		2013			2012			2011
	Federal tax expense at statutory rates	$	7,406		$	7,481		$	5,019
	Tax credits		(28,421	)		(17,100	)		(13,142	)
	Tax credit-basis reduction		2,019			2,767			3,112
	Tax-exempt income		(832	)		(655	)		(509	)
	Change in deferred rate		—			—			293
	Disallowed interest expense		117			99			101
	Other		(40	)		(157	)		(281	)
	Income tax benefit	$	(19,751	)	$	(7,565	)	$	(5,407	)
	As discussed in Note 12, the Company earns Federal NMTC, Historic, and Low-Income Housing tax credits, which reduce the Company’s federal income tax liability or creates a carryforward as applicable.
	The components of the Company’s deferred tax assets and liabilities as of December 31 are presented below (in thousands):
		Year Ended December 31,
		2013			2012
	Deferred tax assets:
	Loan loss reserve	$	11,250		$	9,397
	Tax credit carryforwards		65,216			37,353
	NOL carryforward		7,317			4,030
	Stock-based compensation		684			436
	Deferred compensation		91			91
	Securities available for sale		8,880			1,563
	Other real estate		250			269
	Basis difference in assumed liabilities		338			1,701
	Other		373			355
	Total deferred tax assets		94,399			55,195
	Deferred tax liabilities:
	Fixed assets		6,546			5,867
	Deferred loan costs		5,157			4,414
	Amortizable costs		1,477			1,697
	State tax credits		1,155			669
	Investments in tax credit entities		28,097			25,789
	Other		776			170
	Total deferred tax liabilities		43,208			38,606
	Net deferred tax assets	$	51,191		$	16,589
	In the opinion of management, no valuation allowance was required for the net deferred tax assets at December 31, 2013 as the amounts will more likely than not be realized as reductions of future taxable income.
	As of December 31, 2013, the Company’s net operating loss (NOL) carryforwards were $20.9 million with an expiration date of December 2035.
	As of December 31, 2013, the Company’s tax credit carryforwards were $65.2 million with expiration dates beginning December 2029 through December 2033.
	The Company recognized $14.2 million, $11.4 million, and $7.9 million in Federal NMTC in its consolidated income tax provision for the years ended December 31, 2013, 2012, and 2011, respectively. The Company recognized $3.7 million, $2.5 million, and $2.8 million in Low-Income Housing Tax Credits in its consolidated income tax provision for the years ended December 31, 2013, 2012, and 2011, respectively. The Company recognized $10.5 million, $3.2 million and $2.2 million in Historic Tax Credits in its consolidated income tax provision for the years ended December 31, 2013, 2012, and 2011, respectively.

Shareholders_Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Shareholders' Equity	'
	20. Shareholders’ Equity
	Senior Preferred Stock
	During 2013 and 2012, the holder of the Company’s convertible perpetual preferred stock Series C converted 551,858 shares and 763,378 shares, respectively, into shares of the Company’s $1 par common stock. In 2011, the Company sold approximately $20.6 million of convertible perpetual preferred stock Series C. At December 31, 2013, the Series C preferred stock had an aggregate liquidation preference of approximately $20.6 million and qualified as Tier 1 regulatory capital. Each share of Series C preferred stock is convertible at the option of the holder, except in certain circumstances when regulatory approval is necessary, into one share of common stock. The Series C preferred stock ranks pari passu with the common stock with respect to the payment of dividends. The contingency on the Series C preferred stock was in effect at December 31, 2013 and 2012, respectively.
	During 2011, the Company sold approximately $37.9 million of senior noncumulative perpetual preferred stock, Series D to the Treasury, pursuant to the Small Business Lending Fund program. At December 31, 2013, the Series D preferred stock had an aggregate liquidation preference of approximately $37.9 million and qualified as Tier 1 regulatory capital.
	The terms of the Series D preferred stock provide for payment of noncumulative dividends on a quarterly basis beginning October 3, 2011. The dividend rate, as a percentage of the liquidation amount, fluctuates, while the Series D preferred stock is outstanding based upon changes in the level of qualified small business lending (QSBL) by the Company from its average level of QSBL at each of the four quarter-ends leading up to June 30, 2010 (Baseline), as follows:
	Dividend Period		Annualized
	Beginning	Ending	Dividend Rate
	August 4, 2011	September 30, 2011	1.54%
	October 1, 2011	December 31, 2011	1.00%
	January 1, 2012	March 31, 2012	1.00%
	April 1, 2012	June 30, 2012	1.00%
	July 1, 2012	December 31, 2013	1.000% to 5.000%
	January 1, 2014	February 3, 2016	1.000% to 7.000%
	February 4, 2016	Redemption	9.00%
	As long as shares of Series D preferred stock remain outstanding, the Company may not pay dividends to common shareholders (nor may the Company repurchase or redeem any shares of common stock) during any quarter in which the Company fails to declare and pay dividends on the Series D preferred stock and for the next three quarters following such failure. In addition, under the terms of the Series D preferred stock, the Company may only declare and pay dividends on common stock (or repurchase shares of common stock) if, after payment of such dividend, the dollar amount of Tier 1 capital would be at least 90% of Tier 1 capital as of August 4, 2011, excluding charge-offs and redemptions of the Series D preferred stock (Tier 1 dividend threshold). Beginning January 1, 2014, the Tier 1 dividend threshold is subject to reduction based upon the extent by which, if at all, the QSBL at September 30, 2013, has increased over the Baseline. During 2013, the Company was notified that its dividend rate would be 1% from January 1, 2014 until February 3, 2016 because the Company satisfied the lending baseline at September 30, 2013.
	The Company may redeem the Series D preferred stock at any time at the Company’s option, at a redemption price of 100% of the liquidation amount plus accrued but unpaid dividends, subject to the approval of the Company’s primary federal regulatory agency.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Accumulated Other Comprehensive Income	'
	21. Accumulated Other Comprehensive Income
	The components of accumulated other comprehensive income and changes in those components are presented in the following table (in thousands):
		Cash Flow			Transfers of			Available for			Total
		Hedge			Available for			Sale
					Sale			Securities
					Securities to
					Held to
					Maturity
	Balance at January 1, 2013	$	(4,455	)	$	—		$	1,529		$	(2,926	)
	Other comprehensive income before income taxes:
	Net change in unrealized gain (loss)		3,694			—			(18,576	)		(14,882	)
	Transfer of net unrealized loss from available for sale to held to maturity, net of cumulative tax effect		—			(5,919	)		—			(5,919	)
	Reclassification of net gains realized and included in earnings		—			—			(316	)		(316	)
	Amortization of unrealized net loss on securities		—			211			—			211
	Income tax expense (benefit)		1,293			(1,998	)		(6,612	)		(7,317	)
	Balance at December 31, 2013	$	(2,054	)	$	(3,710	)	$	(10,751	)	$	(16,515	)
	Balance at January 1, 2012	$	—		$	—		$	1,795		$	1,795
	Other comprehensive income before income taxes:
	Net change in unrealized (loss) gain		(6,854	)		—			3,956			(2,898	)
	Reclassification of net gains realized and included in earnings		—			—			(4,324	)		(4,324	)
	Income tax (benefit)		(2,399	)		—			(102	)		(2,501	)
	Balance at December 31, 2012	$	(4,455	)	$	—		$	1,529		$	(2,926	)
	Balance at January 1, 2011	$	—		$	—		$	(1,062	)	$	(1,062	)
	Other comprehensive income before income taxes:
	Net change in unrealized gain		—			—			4,814			4,814
	Reclassification of net gains realized and included in earnings		—			—			(485	)		(485	)
	Income tax expense		—			—			1,472			1,472
	Balance at December 31, 2011	$	—		$	—		$	1,795		$	1,795

Capital_Requirements_and_Other

Capital Requirements and Other Regulatory Matters	12 Months Ended
	Dec. 31, 2013
Text Block [Abstract]	'
Capital Requirements and Other Regulatory Matters	'
	22. Capital Requirements and Other Regulatory Matters
	Regulatory Capital Requirements
	The Company and the Bank are subject to various regulatory capital requirements administered by the federal and state banking agencies. 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 accompanying consolidated financial statements of the Company and the Bank. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company and the Bank must meet specific capital guidelines that involve quantitative measures of their assets, liabilities, and certain off-balance-sheet items. The capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings, and other factors. Prompt corrective action provisions are not applicable to bank holding companies.
	Quantitative measures established by regulation to ensure capital adequacy require the Company and the Bank to maintain minimum amounts and ratios of total and Tier 1 capital to risk-weighted assets and to maintain minimum amounts and ratios of Tier 1 capital to average assets. Management believes, as of December 31, 2013 and 2012, that the Company and the Bank met all capital adequacy requirements to which they are subject.
	As of December 31, 2013, the most recent notification from the Federal Deposit Insurance Corporation categorized the Bank as “well capitalized” under the regulatory framework for prompt corrective action. To be categorized as well capitalized, an institution must maintain minimum total risk-based, Tier 1 risk-based, and Tier 1 leverage ratios as set forth in the following table. At December 31, 2013 and 2012, management believes the Bank has met the ratios for being considered well-capitalized. The Company and the Bank’s actual capital amounts and ratios as of December 31 were as follows (in thousands):
		Actual					For Capital Adequacy					To Be Well Capitalized
							Purposes					Under Prompt Corrective
												Action Provisions
		Amount		Ratio			Amount		Ratio			Amount		Ratio
	December 31, 2013
	Tier 1 leverage capital:
	First NBC Bank Holding Company	$	375,355		11.76	%	$	127,625		4	%		NA		NA
	First NBC Bank		349,104		10.96	%		127,435		4	%	$	159,294		5	%
	Tier 1 risk-based capital:
	First NBC Bank Holding Company		375,355		13.26	%		113,254		4	%		NA		NA
	First NBC Bank		349,104		12.34	%		113,170		4	%	$	169,755		6	%
	Total risk-based capital:
	First NBC Bank Holding Company		407,648		14.4	%		226,508		8	%		NA		NA
	First NBC Bank		381,396		13.48	%		226,340		8	%	$	282,924		10	%
		Actual					For Capital Adequacy					To Be Well Capitalized
							Purposes					Under Prompt Corrective
												Action Provisions
		Amount		Ratio			Amount		Ratio			Amount		Ratio
	December 31, 2012
	Tier 1 leverage capital:
	First NBC Bank Holding Company	$	243,791		9.04	%	$	107,814		4	%		NA		NA
	First NBC Bank		256,848		9.91	%		103,704		4	%	$	129,630		5	%
	Tier 1 risk-based capital:
	First NBC Bank Holding Company		243,791		11.26	%		86,592		4	%		NA		NA
	First NBC Bank		256,848		11.88	%		86,457		4	%	$	129,686		6	%
	Total risk-based capital:
	First NBC Bank Holding Company		270,810		12.51	%		173,184		8	%		NA		NA
	First NBC Bank		283,867		13.13	%		172,914		8	%	$	216,143		10	%

Warrants

Warrants	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Warrants	'
	23. Warrants
	In connection with their financing of the start-up activities of the Company, the organizing shareholders of the Company received warrants for 162,500 shares of common stock with an exercise price of $10 per share. The warrants are exercisable immediately and have an expiration date of 10 years. No charge was made to income in connection with the warrants. During 2013, 37,500 shares of the organizing shareholders of the Company’s warrants were exercised. As of December 31, 2013, a total of 125,000 organizer warrants remained outstanding. In connection with the acquisition of Dryades Bancorp, Inc. in 2010, the Company issued 87,509 warrants at $19.50 per share, 9,633 shares of these warrants were exercised during 2013, and 77,426 remained outstanding as of December 31, 2013.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Stock-Based Compensation	'
	24. Stock-Based Compensation
	The Company has various types of stock-based compensation plans. These plans are administered by the Compensation and Human Resources Committee of the Board of Directors, which selects persons eligible to receive awards and approves the number of shares and/or options subject to each award, the terms, conditions, and other provisions of the awards.
	Restricted Stock
	The Company issues restricted stock under the 2006 Plan for certain officers and directors. The 2006 Plan authorized the issuance of restricted stock. The plan allows for the issuance of restricted stock awards that may not be sold or otherwise transferred until certain restrictions have lapsed. The fair value of the restricted stock shares awarded under the plan is recorded as unearned share-based compensation, a contra-equity account. The unearned compensation related to these awards is amortized over the vesting period (generally 5 years). The total share-based compensation expense related to the awards is determined based upon an independent valuation of the restricted stock as of the grant date applied to the total number of shares granted and is amortized over the vesting period. There were 25,667 shares of restricted stock vested as of December 31, 2013. There was no unearned share-based compensation associated with these awards as of December 31, 2013. There were no restricted shares issued during 2013 and 2012, respectively.
	There was no compensation expense that was included in salaries and benefits expense in the accompanying consolidated statements of income for the years ended December 31, 2013 and 2012, respectively. There was $0.3 million in compensation expense that was included in salaries and benefits expense in the accompanying consolidated statements of income for the year ended December 31, 2011.
	Stock Options
	The Company issues stock options to directors, officers, and other key employees. The option exercise price cannot be less than the fair value of the underlying common stock as of the date of the option grant and the maximum option term cannot exceed ten years. The stock options granted were issued with vesting periods ranging from three to four years. At December 31, 2013, there were 0.3 million shares available for future issuance of option or restricted stock awards under approved compensation plans.
	For the years ended December 31, 2013, 2012 and 2011, total stock option compensation expense that is included in salaries and employee benefits expense was $0.7 million, $0.5 million and $0.3 million, respectively. The related income tax benefit in the accompanying consolidated statements of income was $0.2 million, $0.2 million and $0.1 million, respectively.
	The Company uses the Black-Scholes option pricing model to estimate the fair value of the stock options awards. The following weighted-average assumptions were used for option awards granted during the years ended December 31 of the periods indicated:
		2013			2012			2011
	Expected dividend yield		0	%		0	%		0	%
	Weighted-average expected volatility		36.68	%		35.33	%		31.5	%
	Weighted-average risk-free interest rate		1.73	%		1.25	%		2.87	%
	Expected option term (in years)		6			6.3			6
	Contractual term (in years)		10			10			10
	Weighted-average grant date fair value	$	5.22		$	5.49		$	4.33
	The assumptions above were based on multiple factors, primarily the historical stock option patterns of a group of publicly traded peer banks based in the southeastern United States.
	At December 31, 2013, there was $1.8 million in unrecognized compensation cost related to stock options which is expected to be recognized over a weighted-average period of 2 years.
	The following table represents the activity related to stock options during the periods indicated.
		Number			Weighted-			Weighted-
		of Shares			Average			Average
					Exercise			Remaining
					Price			Contractual
								Term (Years)
	Options outstanding, December 31, 2010		215,000		$	10.04
	Granted		229,657			12.25
	Exercised		—			—
	Forfeited or expired		(999	)		12.23
	Options outstanding, December 31, 2011		443,658			11.11
	Granted		378,692			14.69
	Exercised		—			—
	Forfeited or expired		(13,333	)		14.43
	Options outstanding, December 31, 2012		809,017			11.81
	Granted		139,650			16.16
	Exercised		(76,966	)		10.39
	Forfeited or expired		(16,600	)		15.16
	Options outstanding, December 31, 2013		855,101		$	13.48			7
	Options exercisable, December 31, 2011		270,599		$	10.53
	Options exercisable, December 31, 2012		289,444		$	10.6
	Options exercisable, December 31, 2013		374,535		$	11.94			6
	The following table presents weighted-average remaining life as of December 31, 2013 for options outstanding within the stated exercise prices:
		Options Outstanding									Options Exercisable
	Exercise Price Range	Number			Weighted-			Weighted-			Number		Weighted-
	Per Share	of Shares			Average			Average			of Shares		Average
					Exercise			Remaining					Exercise
					Price			Life					Price
								(Years)
	$10.00-$12.70		368,181		$	11.35			5			292,074	$	11.11
	$14.20-$14.88		351,870			14.68			8			82,461		14.88
	$15.88-$23.68		135,050			16.17			9			—		—
	Total Options		855,101		$	13.48			7			374,535	$	11.94
	At December 31, 2013, the aggregate intrinsic value of shares underlying outstanding stock options and underlying exercisable stock options was $16.1 million and $7.6 million. Total intrinsic value of options exercised was $1.2 million for the year ended December 31, 2013. There were no options exercised during the years ended December 31, 2012 and 2011, respectively.

Financial_Instruments_With_Off

Financial Instruments With Off-Balance-Sheet Risk	12 Months Ended
	Dec. 31, 2013
Investments All Other Investments [Abstract]	'
Financial Instruments With Off-Balance-Sheet Risk	'
	25. Financial Instruments With Off-Balance-Sheet Risk
	The Company is a party to various financial instruments with off-balance-sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit, which are recorded when they are funded. Such commitments involve, to varying degrees, elements of credit risk in excess of the amounts recognized in the accompanying consolidated financial statements.
	At December 31, 2013 and 2012, the Company had made various commitments to extend credit of $375.2 million and $348.6 million, respectively. The Company’s management does not anticipate any material loss as a result of these transactions.
	Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being fully drawn upon, the total commitment amounts disclosed above do not necessarily represent future cash requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. The amount of collateral obtained, if considered necessary upon extension of credit, is based on management’s credit evaluation of the counterparty.
	Standby letters of credit represent commitments by the Company to meet the obligations of certain customers, if called upon. These financial instruments are considered guarantees in accordance with ASC 460. Outstanding standby letters of credit as of December 31, 2013, were $106.5 million and expire between 2014 and 2040. Outstanding standby letters of credit as of December 31, 2012, were $92.2 million and expire between 2013 and 2040. Net unamortized fees related to letters of credit origination were $0.2 million and $54,000 in 2013 and 2012, respectively. Net unamortized costs related to letters of credit origination were $0.3 million and $0.4 million in 2013 and 2012, respectively.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	26. Commitments and Contingencies
	The Company leases certain branch offices through noncancelable operating leases with terms that range from one to 30 years, with renewal options thereafter. Certain leases have escalation clauses and renewal options ranging from one to 59 years. Rent expense was approximately $3.4 million for the years ended December 31, 2013 and 2012, respectively, and $2.7 million for the year ended December 31, 2011.
	At December 31, 2013, the minimum annual rental payments to be made under the noncancelable leases are as follows (in thousands):
	Year ending December 31:
	2014	$	3,119
	2015		2,993
	2016		3,011
	2017		3,018
	2018		2,697
	Thereafter		41,259
		$	56,097
	Off-Balance-Sheet Arrangements
	The Company is a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These transactions include commitments to extend credit in the ordinary course of business to approved customers. Generally, loan commitments have been granted on a temporary basis for working capital or commercial real estate financing requirements or may be reflective of loans in various stages of funding. These commitments are recorded on the Company’s financial statements as they are funded. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Loan commitments include unused commitments for open-end lines secured by one to four family residential properties and commercial properties, commitments to fund loans secured by commercial real estate, construction loans, business lines of credit, and other unused commitments. 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 minimizes its exposure to loss under loan commitments and standby letters of credit by subjecting them to credit approval and monitoring procedures. The effect on the Company’s revenues, expenses, cash flows, and liquidity of the unused portions of these commitments cannot be reasonably predicted because there is no guarantee that the lines of credit will be used.
	The following is a summary of the total notional amount of loan commitments and standby letters of credit outstanding at December 31, 2013 and 2012 (in thousands):
		2013		2012
	Standby letters of credit	$	106,467	$	92,274
	Unused loan commitments		268,760		256,294
		$	375,227	$	348,568

RelatedParty_Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2013
Related Party Transactions [Abstract]	'
Related-Party Transactions	'
	27. Related-Party Transactions
	In the ordinary course of business, the Company makes loans to and holds deposits for directors and executive officers of the Company and their associates.
	The amounts of such related-party loans were $47.8 million and $66.6 million at December 31, 2013 and 2012, respectively. During 2013, $36.4 million in related-party loans were funded and $55.2 million were repaid. None of the related-party loans were classified as nonaccrual, past due, restructured, or potential problem loans at December 31, 2013 or 2012. The amounts of such related-party deposits were $17.9 million and $16.1 million at December 31, 2013 and 2012, respectively.
	The Company leases a building from a partnership that is owned by two directors of the Company. The Company paid approximately $0.2 million in rent expense related to this lease for the years ended December 31, 2013, 2012, and 2011. The lease also includes options for multiple five-year term extensions beyond the original lease expiration of October 2004, provided there were no defaults of material lease provisions by the lessee. The Company exercised an option to extend the lease for an additional five years in October 2009.

Employee_Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2013
Compensation And Retirement Disclosure [Abstract]	'
Employee Benefits	'
	28. Employee Benefits
	401(k) Profit-Sharing Plan
	The Company participates in a contributory retirement and savings plan (the Plan), which covers substantially all employees and meets the requirements of Section 401(k) of the Internal Revenue Code. Employer contributions to the Plan are based on the participants’ contributions, with an additional discretionary contribution as determined by the Board of Directors. Company contributions under the Plan were approximately $1.0 million, $0.9 million, and $0.4 million for the years ended December 31, 2013, 2012, and 2011, respectively. The Company pays all expenses associated with the Plan.
	Employee Stock Ownership Plan
	The Company Sponsors an employee stock ownership plan (ESOP), which holds 50,000 shares of Company stock, subject to indebtedness utilized to purchase the shares in 2009. The leveraged ESOP allocates shares annually to eligible employee participants pro rata based on compensation. All participants vest in the annual allocations at 20% per year. The Company recognized compensation expense with respect to the ESOP of $0.2 million for the years ended December 31, 2013 and 2012, respectively, and $0.1 million for the year ended December 31, 2011. The Company pays all expenses associated with the ESOP.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	29. Fair Value of Financial Instruments
	ASC 820, Fair Value Measurements and Disclosures, clarifies the principle that fair value should be based on the assumptions that market participants would use when pricing the asset or liability and establishes a fair value hierarchy that prioritizes the inputs used to develop those assumptions and measure fair value. The hierarchy requires companies to maximize the use of observable inputs and minimize the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows:
	Level 1 – Quoted prices in active markets for identical assets or liabilities.
	Level 2 – Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data.
	Level 3 – Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. This includes certain pricing models, discounted cash flow methodologies, and similar techniques that use significant unobservable inputs.
	A description of the valuation methodologies used for instruments measured at fair value follows, as well as the classification of such instruments within the valuation hierarchy.
	Securities are classified within Level 1 when quoted market prices are available in an active market. Inputs include securities that have quoted prices in active markets for identical assets. If quoted market prices are unavailable, fair value is estimated using pricing models or quoted prices of securities with similar characteristics, at which point the securities would be classified within Level 2 of the hierarchy. Examples include certain available for sale securities. The Company’s investment portfolio did not include Level 3 securities as of December 31, 2013 and December 31, 2012.
	The Company has segregated all financial assets and liabilities that are measured at fair value on a recurring basis into the most appropriate level within the fair value hierarchy, based on the inputs used to determine the fair value at the measurement date in the tables below (in thousands):
				December 31, 2013
				Fair Value Measurement Using
		Total		Quoted Prices		Significant		Significant
				in Active		Other		Unobservable
				Markets for		Observable		Inputs
				Identical Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Assets
	Available for sale securities	$	277,719	$	—	$	277,719	$	—
	Derivative instruments		1,157		—		1,157	$	—
	Total	$	278,876	$	—	$	278,876	$	—
	Liabilities
	Derivative instruments	$	4,317	$	—	$	4,317	$	—
				31-Dec-12
				Fair Value Measurement Using
		Total		Quoted Prices		Significant		Significant
				in Active		Other		Unobservable
				Markets for		Observable		Inputs
				Identical Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Assets
	Available for sale securities	$	405,355	$	—	$	405,355	$	—
	Liabilities
	Derivative instruments	$	6,854	$	—	$	6,854	$	—
	The Company has segregated all financial assets and liabilities that are measured at fair value on a nonrecurring basis into the most appropriate level within the fair value hierarchy based on the inputs used to determine the fair value at the measurement date in the tables below (in thousands):
				December 31, 2013
				Fair Value Measurement Using
		Total		Quoted Prices		Significant		Significant
				in Active		Other		Unobservable
				Markets for		Observable		Inputs
				Identical Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Assets
	Loans	$	9,782	$	—	$	—	$	9,782
	OREO		2,390		—		—		2,390
		$	12,172	$	—	$	—	$	12,172
				31-Dec-12
				Fair Value Measurement Using
		Total		Quoted Prices		Significant		Significant
				in Active		Other		Unobservable
				Markets for		Observable		Inputs
				Identical Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Assets
	Loans	$	21,313	$	—	$	—	$	21,313
	OREO		5,434		—		—		5,434
		$	26,747	$	—	$	—	$	26,747
	In accordance with ASC Topic 310, the Company records loans and other real estate considered impaired at the lower of cost or fair value. Impaired loans, recorded at fair value, are Level 3 assets measured using appraisals from external parties of the collateral, less any prior liens primarily using the market or income approach.
	The Company did not record any liabilities at fair value for which measurement of the fair value was made on a nonrecurring basis during the years ended December 31, 2013 and December 31, 2012.
	ASC 820 requires the disclosure of the fair value for each class of financial instruments for which it is practicable to estimate. The fair value of a financial instrument is the current amount that would be exchanged between willing parties, other than in a forced liquidation. Fair value is best determined based upon quoted market prices. However, in many instances, there are no quoted market prices for the Company’s various financial instruments. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Accordingly, the fair value estimates may not be realized in an immediate settlement of the instrument. ASC 820 excludes certain financial instruments and all nonfinancial instruments from its disclosure requirements. Accordingly, the aggregate fair value amounts presented may not necessarily represent the underlying fair value of the Company.
	The following methods and assumptions were used to estimate the fair value of each class of financial instrument for which it is practicable to estimate that value.
	Cash and Cash Equivalents and Short-Term Investments
	The carrying amounts of these short-term instruments approximate their fair values.
	Investment in Short-Term Receivables
	The carrying amounts of these short-term receivables approximate their fair values.
Investment Securities
Securities are classified within Level 1 where quoted market prices are available in the active market. If quoted market prices are unavailable, fair value is estimated using pricing models or quoted prices of securities with similar characteristics, at which point the securities would be classified within Level 2 of the hierarchy. Inputs include securities that have quoted prices in active markets for identical assets.
Loans
For variable-rate loans that reprice frequently and have no significant change in credit risk, fair values are based on carrying values. Fair values for fixed-rate commercial real estate, commercial loans, and consumer loans are estimated using discounted cash flow analyses using interest rates currently being offered for loans with similar terms and borrowers of similar credit quality. Fair value of mortgage loans held for sale is based on commitments on hand from investors or prevailing market rates. The fair value associated with the loans includes estimates related to expected prepayments and the amount and timing of undiscounted expected principal, interest and other cash flows, which would be classified as Level 3 of the hierarchy.
Bank-Owned Life Insurance
The carrying amounts of the bank-owned life insurance policies are recorded at cash surrender value, which approximate their fair values.
Deposits
The fair values disclosed for demand deposits are, by definition, equal to the amount payable on demand at the reporting date (that is, their carrying amounts). The carrying amounts of variable-rate, fixed-term money market accounts approximate their fair values at the reporting date. Fair values for fixed-rate certificates of deposit are estimated using a discounted cash flow calculation that applies interest rates currently being offered on certificates to a schedule of aggregated expected monthly maturities on time deposits. The fair value of the Company’s deposits would, therefore, be categorized within Level 3 of the fair value hierarchy.
Short-Term Borrowings and Repurchase Agreements
The carrying amounts of these short-term instruments approximate their fair values.
Long-Term Borrowings
The fair values of long-term borrowings are estimated using discounted cash flows analyses based on the Company’s current incremental borrowing rates for similar types of borrowing arrangements. The fair value of the Company’s long-term debt would, therefore, be categorized within Level 3 of the fair value hierarchy.
Derivative Instruments
Fair values for interest rate swap agreements are based upon the amounts required to settle the contracts. The derivative instruments are classified within Level 2 of the fair value hierarchy.
The estimated fair values of the Company’s financial instruments were as follows as of the dates indicated (in thousands):
	Fair Value Measurements at December 31, 2013
	Carrying		Total		Level 1		Level 2		Level 3
	Amount
Financial Assets:
Cash and due from banks	$	28,140	$	28,140	$	28,140	$	—	$	—
Short-term investments		3,502		3,502		3,502		—		—
Investment in short-term receivables		246,817		246,817		246,817
Investment securities available for sale		277,719		277,719		—		277,719		—
Investment securities held to maturity		94,904		90,966				90,966
Loans and loans held for sale		2,364,354		2,344,475		—		—		2,344,475
Cash surrender value of bank-owned life insurance		26,187		26,187		—		26,187		—
Derivative instruments		1,157		1,157		—		1,157		—
Financial Liabilities:
Deposits, noninterest-bearing		291,080		291,080		—		291,080		—
Deposits, interest-bearing		2,439,727		2,380,985		—		—		2,380,985
Short-term borrowings and repurchase agreements		84,382		84,382		—		84,382		—
Long-term borrowings		55,110		55,616		—		—		55,616
Derivative instruments		4,317		4,317		—		4,317		—
	Fair Value Measurements at December 31, 2012
	Carrying		Total		Level 1		Level 2		Level 3
	Amount
Financial Assets:
Cash and due from banks	$	26,471	$	26,471	$	26,471	$	—	$	—
Short-term investments		9,541		9,541		9,541		—		—
Investment in short-term receivables		81,044		81,044		81,044
Investment securities available for sale		405,355		405,355		—		405,355		—
Loans and loans held for sale		1,948,077		1,939,622		—		—		1,939,622
Cash surrender value of bank-owned life insurance		25,506		25,506		—		25,506		—
Financial Liabilities:
Deposits, noninterest-bearing		239,538		239,538		—		239,538		—
Deposits, interest-bearing		2,028,990		2,035,696		—		—		2,035,696
Short-term borrowings and repurchase agreements		58,087		58,087		—		58,087		—
Long-term borrowings		75,220		77,870		—		—		77,870
Derivative instruments		6,854		6,854		—		6,854		—

Parent_Company_Only_Financial_

Parent Company Only Financial Statements	12 Months Ended
	Dec. 31, 2013
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]	'
Parent Company Only Financial Statements	'
	30. Parent Company Only Financial Statements
	Financial statements of First NBC Bank Holding Company (parent company only) are shown below. The parent company has no significant operating activities.
	Balance Sheets
		December 31,
	(in thousands)	2013			2012
	Assets
	Cash and due from banks	$	23,990		$	3,709
	Goodwill		841			841
	Investments in subsidiaries		355,068			260,618
	Other assets		2,123			3,157
	Total assets	$	382,022		$	268,325
	Liabilities and shareholders’ equity
	Long-term borrowings	$	110		$	20,220
	Other liabilities		53			4
	Total liabilities		163			20,224
	Total shareholders’ equity		381,859			248,101
	Total liabilities and shareholders’ equity	$	382,022		$	268,325
	Statements of Income
		Year Ended December 31,
	(in thousands)	2013			2012			2011
	Operating income
	Interest income	$	—		$	—		$	—
	Dividend from bank subsidary		2,000			—			—
	Total operating income		2,000			—			—
	Operating expense
	Interest expense		424			11			14
	Other expense		856			431			188
	Total operating expense		1,280			442			202
	Income (loss) before income tax benefit and increase in equity in undistributed earnings of subsidiaries		720			(442	)		(202	)
	Income tax benefit		(448	)		(155	)		(71	)
	Income (loss) before equity in undistributed earnings of subsidiaries		1,168			(287	)		(131	)
	Equity in undistributed earnings of subsidiaries		39,743			29,227			19,571
	Net income		40,911			28,940			19,440
	Preferred stock dividends and discount accretion		(347	)		(510	)		(1,372	)
	Income available to common shareholders	$	40,564		$	28,430		$	18,068
	Statements of Cash Flows
		Year Ended December 31,
	(in thousands)	2013			2012			2011
	Operating activities
	Net income	$	40,911		$	28,940		$	19,440
	Adjustments to reconcile net income to net cash (used in) provided by operating activities:
	Net income of subsidiaries		(39,743	)		(29,227	)		(19,571	)
	Deferred tax benefit		(448	)		(155	)		(71	)
	Stock compensation		1,155			97			715
	Changes in operating assets and liabilities:
	Change in other assets		1,481			(1,989	)		(762	)
	Change in other liabilities		50			—			3
	Net cash provided by (used in) operating activities		3,406			(2,334	)		(246	)
	Investing activities
	Capital contributed to subsidiary, net		(67,000	)		(16,600	)		(67,508	)
	Net cash used in investing activities		(67,000	)		(16,600	)		(67,508	)
	Financing activities
	Proceeds from long-term borrowings		—			20,000			—
	Repayment of borrowings		(20,110	)		(110	)		(110	)
	Repayment of preferred stock		—			—			(18,685	)
	Proceeds from sale of preferred stock, net of offering costs		—			—			58,518
	Proceeds from sale of common stock, net of offering costs		104,332			1,420			30,430
	Dividends paid		(347	)		(510	)		(792	)
	Net cash provided by financing activities		83,875			20,800			69,361
	Net change in cash, due from banks, and short-term investments		20,281			1,866			1,607
	Cash, due from banks, and short-term investments at beginning of period		3,709			1,843			236
	Cash, due from banks, and short-term investments at end of period	$	23,990		$	3,709		$	1,843

Consolidated_Quarterly_Results

Consolidated Quarterly Results of Operations	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Consolidated Quarterly Results of Operations	'
	31. Consolidated Quarterly Results of Operations (Unaudited)
	(dollars in thousands, except per share data)		First Quarter			Second			Third			Fourth
						Quarter			Quarter			Quarter
	Year Ended December 31, 2013
	Total interest income		$	28,580		$	29,034		$	31,973		$	34,437
	Total interest expense			8,893			9,779			10,150			10,326
	Net interest income			19,687			19,255			21,823			24,111
	Provision for loan losses			2,600			2,400			2,400			2,400
	Net interest income after provision for loan losses			17,087			16,855			19,423			21,711
	Noninterest income			2,817			2,738			2,461			5,400
	Noninterest expense			15,633			15,185			17,092			19,422
	Income before income taxes			4,271			4,408			4,792			7,689
	Income tax benefit			(4,013	)		(4,198	)		(5,673	)		(5,867	)
	Net income			8,284			8,606			10,465			13,556
	Less net income attributable to noncontrolling interest			—			—			—			—
	Net income attributable to Company			8,284			8,606			10,465			13,556
	Less preferred stock dividends			(95	)		(95	)		(62	)		(95	)
	Income available to common shareholders		$	8,189		$	8,511		$	10,403		$	13,461
	Earnings per common share-basic		$	0.59		$	0.51		$	0.55		$	0.71
	Earnings per common share-diluted		$	0.58		$	0.49		$	0.54		$	0.69
	(dollars in thousands, except per share data)		First Quarter			Second			Third			Fourth
						Quarter			Quarter			Quarter
	Year Ended December 31, 2012
	Total interest income		$	25,355		$	25,781		$	26,927		$	28,394
	Total interest expense			7,338			7,742			7,935			8,651
	Net interest income			18,017			18,039			18,992			19,743
	Provision for loan losses			2,635			1,800			1,800			4,800
	Net interest income after provision for loan losses			15,382			16,239			17,192			14,943
	Noninterest income			2,853			3,968			1,558			4,757
	Noninterest expense			13,738			13,863			13,586			13,820
	Income before income taxes			4,497			6,344			5,164			5,880
	Income tax (benefit) expense(1)			(1,926	)		(2,952	)		(3,130	)		443
	Net income			6,423			9,296			8,294			5,437
	Less net income attributable to noncontrolling interest			(118	)		—			(17	)		(375	)
	Net income attributable to Company			6,305			9,296			8,277			5,062
	Less preferred stock dividends			(95	)		(94	)		(226	)		(95	)
	Income available to common shareholders		$	6,210		$	9,202		$	8,051		$	4,967
	Earnings per common share-basic		$	0.45		$	0.66		$	0.58		$	0.36
	Earnings per common share-diluted		$	0.44		$	0.65		$	0.57		$	0.35
	-1	For the fourth quarter of 2012, the income tax expense was due to an adjustment for actual income tax expense (benefit) for the year ended 2012 due to a reduction in the number of tax credit projects that actually were funded and closed compared to the previous estimate.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Nature of Operations	'
	Nature of Operations
	First NBC Bank Holding Company (“Company”) is a bank holding company that offers a broad range of financial services through First NBC Bank, a Louisiana state non-member bank, to businesses, institutions, and individuals in southeastern Louisiana and the Mississippi Gulf Coast. The accounting and reporting policies of the Company conform to accounting principles generally accepted in the United States and to prevailing practices within the banking industry.
Principles of Consolidation	'
	Principles of Consolidation
	The accompanying consolidated financial statements include the accounts of the Company and First NBC Bank, and First NBC Bank’s wholly owned subsidiaries, which include First NBC Community Development, LLC (FNBC CDC), First NBC Community Development Fund, LLC (FNBC CDE) (collectively referred to as the Bank) and any variable interest entities (VIE) of which the Company is the primary beneficiary. Substantially all of the VIEs that the Company is primary beneficiary relate to tax credit investments. FNBC CDC is a Community Development Corporation formed to construct, purchase, and renovate affordable residential real estate properties in the New Orleans area. FNBC CDE is a Community Development Entity (CDE) formed to apply for and receive allocations of Federal New Markets Tax Credits (NMTC).
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are susceptible to a significant change in the near term are the allowance for loan losses, income tax provision, fair value adjustments and share-based compensation.
Concentration of Credit Risk	'
	Concentration of Credit Risk
	The Company’s loan portfolio consists of the various types of loans described in Note 6. Real estate or other assets secure most loans. The majority of these loans have been made to individuals and businesses in the Company’s market area of southeastern Louisiana and southern Mississippi, which are dependent on the area economy for their livelihoods and servicing of their loan obligations. The Company does not have any significant concentrations to any one industry or customer.
	The Company maintains deposits in other financial institutions that may, from time to time, exceed the federally insured deposit limits.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	For purposes of reporting cash flows, cash and cash equivalents include the amount in the accompanying consolidated balance sheet caption, cash and due from banks, which represents cash on hand and balances due from other financial institutions, as well as the amount in the accompanying consolidated balance sheet caption, short-term investments, which primarily represents federal funds sold with original maturities less than three months.
Investment Securities	'
	Investment Securities
	Investment securities are classified either as held to maturity or available for sale. Management determines the classification of securities when they are purchased.
	Investment securities that the Company has the ability and positive intent to hold to maturity are classified as securities held to maturity and are stated at amortized cost. The amortized cost of debt securities classified as held to maturity or available for sale is adjusted for amortization of premiums and accretion of discounts over the contractual life of the security using the effective interest method or, in the case of mortgage-backed securities, over the estimated life of the security using the effective yield method. Such amortization or accretion is included in interest income on securities.
	Securities that may be sold in response to changes in interest rates, liquidity needs, or asset liability management strategies, are classified as securities available for sale. These securities are carried at fair value, with net unrealized gains or losses excluded from earnings and shown as a separate component of shareholders’ equity in accumulated other comprehensive (loss) income, net of income taxes. Any expected credit loss due to the inability to collect all amounts due accordingly to the security’s contractual terms is recognized as a charge against earnings. Any remaining unrealized loss related to other factors would be recognized in other comprehensive income, net of taxes.
	Realized gains and losses on both held to maturity securities and available for sale securities are computed based on the specific-identification method. Realized gains and losses and declines in value judged to be other than temporary are included in net securities gains and losses.
	Unrealized losses on securities are evaluated to determine if the losses are temporary, based on various factors, including the cause of the loss, prospects for recovery, projected cash flows, collateral values, credit enhancements and other relevant factors, and management’s intent and ability not to sell the security until the fair value exceeds amortized cost. A charge is recognized against earnings for all or a portion of the impairment if the loss is determined to be other than temporary.
Investment in Short-Term Receivables	'
	Investment in Short-Term Receivables
	The Company invests in short-term receivables which are purchased on an exchange. These short-term receivables have repayment terms of less than a year. The investments are recorded on the consolidated balance sheets at cost plus accreted discount.
Mortgage Loans Held for Sale	'
	Mortgage Loans Held for Sale
	Mortgage loans originated and intended for sale in the secondary market are carried at the lower of cost or estimated fair value, in the aggregate. Net unrealized losses, if any, are recognized through a valuation allowance that is recorded as a charge to income. Loans held for sale have primarily been fixed-rate, single-family residential mortgage loans under contract to be sold in the secondary market. In most cases, loans in this category are sold within 120 days. These loans are sold with the mortgage servicing rights released. Buyers generally have recourse to return a purchased loan to the Company under limited circumstances which may include early payment default, breach of representations or warranties, and documentation deficiencies. During 2013 and 2012, an insignificant number of loans were returned to the Company.
Loans	'
	Loans
	Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are stated at the principal amount outstanding, net of unamortized fees and costs on originated loans and allowances for loan losses. Loan origination fees and certain direct loan origination costs are deferred and amortized over the lives of the respective loans as a yield adjustment using the effective interest method.
	Interest income on loans is accrued as earned using the interest method over the life of the loan. Interest on loans deemed uncollectible is excluded from income. The accrual of interest is discontinued and reversed against current income once loans become more than 90 days past due or earlier if conditions warrant. The past due status of loans is determined based on the contractual terms. If the decision is made to continue accruing interest on the loan, periodic reviews are made to confirm the accruing status of the loan. When a loan is placed on nonaccrual status, interest accrued and unpaid during prior periods is reversed. Generally any payments on nonaccrual loans are applied first to outstanding loan principal amounts and then to the recovery of the charged-off loan amounts. Any excess is treated as recovery of lost interest and fees. Loans are returned to accrual status after a minimum of six consecutive monthly payments have been made in a timely manner.
	The Company considers a loan to be impaired when, based upon current information and events, it believes it is probable that the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement. The Company’s impaired loans include troubled debt restructurings (TDRs) and performing and nonperforming loans for which full payment of principal or interest is not expected. The Company calculates a reserve required for impaired loans based on the present value of expected future cash flows discounted using the loan’s effective interest rate or the fair value of the collateral securing the loan.
	Third-party property valuations are obtained at the time of origination for real estate-secured loans. The Company obtains updated appraisals on all impaired loans at least annually. In addition, if an intervening event occurs that, in management’s opinion, would suggest further deterioration in value, the Company obtains an updated appraisal. These policies do not vary based on loan type. Any exposure arising from the deterioration in value of collateral evidenced by the appraisal is recorded as an adjustment to the loan loss reserve in the case of an impaired loan or as an adjustment to income in the case of foreclosed property.
Troubled Debt Restructurings	'
	Troubled Debt Restructurings
	The Company periodically grants concessions to its customers in an attempt to protect as much of its investment as possible and minimize the risk of loss. These concessions may include restructuring the terms of a customer loan, thereby adjusting the customer’s payment requirements. In order to be considered a TDR, the Company must conclude that the restructuring constitutes a concession and the customer is experiencing financial difficulties. The Company defines a concession to a customer as a modification of existing loan terms for economic or legal reasons that it would otherwise not consider. Concessions are typically granted through an agreement with the customer or are imposed by a court of law. Concessions include modifying original loan terms to reduce or defer cash payments required as part of the loan agreement, including but not limited to:
		•		A reduction of the stated interest rate for the remaining original life of the debt
		•		Extension of the maturity date or dates at a stated interest rate lower than the current market rate for new debt with similar risk characteristics
		•		Reduction of the face amount or maturity amount of the debt as stated in the agreement
		•		Reduction of accrued interest receivable on the debt
	In its determination of whether the customer is experiencing financial difficulties, the Company considers numerous indicators, including but not limited to:
		•		Whether the customer is currently in default on its existing loan, or is in an economic position where it is probable the customer will be in default on its loan in the foreseeable future without a modification
		•		Whether the customer has declared or is in the process of declaring bankruptcy
		•		Whether there is substantial doubt about the customer’s ability to continue as a going concern
		•		Whether, based on its projections of the customer’s current capabilities, the Company believes the customer’s future cash flows will be insufficient to service the debt, including interest, in accordance with the contractual terms of the existing agreement for the foreseeable future
		•		Whether, without modification, the customer cannot obtain sufficient funds from other sources at an effective interest rate equal to the current market rate for similar debt for a nontroubled debtor
	If the Company concludes that both a concession has been granted and the concession was granted to a customer experiencing financial difficulties, the Company identifies the loan as a TDR. For purposes of the determination of an allowance for loan losses on these TDRs, the loan is reviewed for specific impairment in accordance with the Company’s allowance for loan loss methodology. If it is determined that losses are probable on such TDRs, either because of delinquency or other credit quality indicators, the Company establishes specific reserves for these loans.
Acquisition Accounting for Loans	'
	Acquisition Accounting for Loans
	The Company accounts for business acquisitions in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 805, Business Combinations, which requires the use of the acquisition method of accounting. All identifiable assets acquired, including loans, are recorded at fair value. The fair value of loans that do not have deteriorated credit quality are accounted for in accordance with ASC 310-20, Nonrefundable Fees and Other Costs, and is represented by the expected cash flows from the portfolio discounted at current market rates. In estimating the cash flows, the Company makes assumptions about the amount and timing of principal and interest payments, estimated prepayments, estimated default rates, estimated loss severities in the event of defaults, and current market rates. The fair value adjustment is amortized over the life of the loan using the effective interest method. The Company accounts for certain acquired loans with deteriorated credit quality under ASC 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality. In accordance with ASC 310-30 and in estimating the fair value of loans with deteriorated credit quality as of the acquisition date, the Company: (a) calculates the contractual amount and timing of undiscounted principal and interest payments (the undiscounted contractual cash flows), and (b) estimates the amount and timing of undiscounted expected principal and interest payments (the undiscounted expected cash flows). The difference between the undiscounted contractual cash flows and the undiscounted expected cash flows is the nonaccretable difference. On the acquisition date, the amount by which the undiscounted expected cash flows exceed the estimated fair value of the loans with deteriorated credit quality is the accretable yield. The accretable yield is recorded into interest income over the estimated lives of the loans using the effective yield method. The accretable yield changes over time as actual and expected cash flows vary from the estimated cash flows at acquisition. Decreases in expected cash flows subsequent to acquisition result in recognition of a provision for loan loss. The accretable yield is measured at each financial reporting date and represents the difference between the remaining undiscounted expected cash flows and the current carrying value of the loans. The remaining undiscounted expected cash flows are calculated at each financial reporting date, based on information currently available. Increases in expected cash flows over those originally estimated increase the accretable yield and are recognized prospectively as interest income. Increases in expected cash flows may also lead to the reduction of any allowance for loan losses recorded after the acquisition. Decreases in expected cash flows compared to those originally estimated decrease the accretable yield and are recognized by recording an allowance for loan losses. As the accretable yield increases or decreases from changes in cash flow expectations, the offset is an increase or decrease to the nonaccretable difference. There is no carryover of allowance for loan losses, as the loans acquired are initially recorded at fair value as of the date of acquisition.
Allowance for Loan Losses	'
	Allowance for Loan Losses
	The allowance for loan losses represents an estimate that management believes will be adequate to absorb probable inherent losses on existing loans in its portfolio at the balance sheet date. The allowance is based on an evaluation of the collectability of loans and prior loss experience, including both industry and Company specific considerations. While management uses available information to make loan loss allowance evaluations, adjustments to the allowance may be necessary based on changes in economic and other conditions or changes in accounting guidance. See Note 6 for an analysis of the Company’s allowance for loan losses by portfolio and portfolio segment, and credit quality information by class.
	Management has an established methodology to determine the adequacy of the allowance for loan losses that assesses the risks and losses inherent in its portfolio and portfolio segments. The Company utilizes an internally developed model that requires significant judgment to determine the estimation method that fits the credit risk characteristics of the loans in its portfolio and portfolio segments. The allowance for loan losses is established through a provision for loan losses charged to expense. The adequacy of the allowance for loan losses is determined in accordance with generally accepted accounting principles.
	The Company’s loan portfolio is disaggregated into portfolio segments for purposes of determining the allowance for loan losses. The Company’s portfolio segments include commercial real estate, consumer real estate, commercial and industrial, and consumer loans. The Company further disaggregates the commercial and consumer real estate portfolio segments into classes for purposes of monitoring and assessing credit quality based on certain risk characteristics. Classes within each commercial real estate portfolio segment include commercial real estate construction and commercial real estate mortgage. Classes within each consumer real estate portfolio segment include consumer real estate construction and consumer real estate mortgage.
	Loans are charged off against the allowance for loan losses when management believes that the collectability of the principal is unlikely. The allowance for loan losses consists of specific and general reserves. The Company determines specific reserves based on the provisions of ASC 310, Receivables. The Company’s allowance for loan losses includes a measure of impairment for those loans specifically identified for evaluation under the topic. This measurement is based on a comparison of the recorded investment in the loan with either the expected cash flows discounted using the loan’s original contractual effective interest rate or the fair value of the collateral underlying certain collateral-dependent loans. Collectability of principal and interest is evaluated in assessing the need for a loss accrual. Loans identified as impaired are individually evaluated periodically for impairment.
	General reserves are based on management’s evaluation of many factors and reflect an estimated measurement of losses related to loans not individually evaluated for impairment. These loans are grouped into portfolio segments. The loss rates are derived from historical loss factors of the Company or the industry sustained on loans according to their risk grade, as well as qualitative and economic factors, and may be adjusted for Company-specific factors. Loss rates are reviewed quarterly and adjusted as management deems necessary based on changing borrower and/or collateral conditions and actual collections and charge-off experience.
	Based on observations made through a qualitative review, management may apply qualitative adjustments to the quantitatively determined loss estimates at a group and/or portfolio segment level as deemed appropriate. Primary qualitative and environmental factors that may not be directly reflected in quantitative estimates include:
		•		Asset quality trends
		•		Changes in lending policies
		•		Trends in the nature and volume of the loan portfolio, including the existence and effect of any portfolio concentrations
		•		Changes in experience and depth of lending staff
		•		National and regional economic trends
	Changes in these factors are considered in determining the directional consistency of changes in the allowance for loan losses. The impact of these factors on the Company’s qualitative assessment of the allowance for loan losses can change from period to period based on management’s assessment to the extent to which these factors are already reflected in historic loss rates. The uncertainty inherent in the estimation process is also considered in evaluating the allowance for loan losses.
Off-Balance-Sheet	'
	Off-Balance-Sheet
Credit-Related Financial Instruments	'
	Credit-Related Financial Instruments
	The Company accounts for its guarantees in accordance with the provisions of ASC 460, Guarantees. In the ordinary course of business, the Company has entered into commitments to extend credit, including commitments under credit card agreements, and standby letters of credit. Such financial instruments are recorded when they are funded.
Derivative Financial Instruments	'
	Derivative Financial Instruments
	ASC 815, Derivatives and Hedging, requires that all derivatives be recognized as assets or liabilities in the balance sheet at fair value. The Company may enter into derivative contracts to manage exposure to interest rate risk or meet the financing and/or investing needs of its customers.
	In the course of its business operations, the Company is exposed to certain risks, including interest rate, liquidity, and credit risk. The Company manages its risks through the use of derivative financial instruments, primarily through management of exposure due to the receipt or payment of future cash amounts based on interest rates. The Company’s derivative financial instruments manage the differences in the timing, amount, and duration of expected cash receipts and payments.
	Derivatives which are designated and qualify as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. The effective portion of the derivative’s gain or loss is initially reported as a component of other comprehensive income and subsequently reclassified into earnings when the forecasted transaction affects earnings or when the hedge is terminated. The ineffective portion of the gain or loss is reported in earnings immediately.
	In applying hedge accounting for derivatives, the Company establishes a method for assessing the effectiveness of the hedging derivative and a measurement approach for determining the ineffective aspect of the hedge upon the inception of the hedge. These methods are consistent with the Company’s approach to managing risk. The Company reports these net in the accompanying consolidated balance sheets when the Company has a master netting arrangement. As of December 31, 2013 there were no net amounts reported. Note 18 describes the derivative instruments currently used by the Company and discloses how these derivatives impact the Company’s financial position and results of operations.
Premises and Equipment	'
	Premises and Equipment
	Land is carried at cost. Buildings, furniture, fixtures, and equipment are carried at cost, less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated life of each respective type of asset as follows:
	Buildings		40 years
	Furniture, fixtures, and equipment		5–15 years
	Leasehold improvements are amortized using the straight-line method over the periods of the leases, including options expected to be exercised, or the estimated useful lives, whichever is shorter. Gains and losses on disposition and maintenance and repairs are included in current operations. Rental expense on leased property is recognized on a straight-line basis over the original lease term plus options that management expects to exercise. Fixed rental increases that are determinable are expensed over the lease period, including any option periods which are expected to be exercised, using a straight-line lease expense method.
Other Real Estate	'
	Other Real Estate
	Assets acquired through, or in lieu of, loan foreclosure are held for sale and are recorded at a new cost basis determined at the date of foreclosure as the lower of cost or fair value less estimated cost to sell. Cost is defined as the recorded investment in the loan. Subsequent to foreclosure, valuation allowances are established for any changes in the estimate of the asset’s fair value or selling costs, but not in excess of its new cost basis. Revenues and expenses from operations and changes in the valuation allowance are included in current earnings.
Goodwill and Other Intangible Assets	'
	Goodwill and Other Intangible Assets
	Goodwill is accounted for in accordance with ASC 350, Intangibles—Goodwill and Other, and, accordingly, is not amortized but is evaluated at least annually for impairment. As part of its annual impairment testing, the Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the Company determines the fair value of a reporting unit is less than its carrying amount using these qualitative factors, the Company compares the fair value of goodwill with its carrying amount, and then measures impairment loss by comparing the implied fair value of goodwill with the carrying amount of that goodwill.
	Definite-lived intangible assets, which consist of core deposit intangibles, are amortized on a straight-line basis over their useful lives and evaluated at least annually for impairment.
Income Taxes	'
	Income Taxes
	The Company accounts for income taxes under the liability method. Deferred tax assets and liabilities are established for the temporary differences between the financial reporting basis and the tax basis of the Company’s assets and liabilities using enacted tax rates expected to be in effect during the year in which the basis differences reverse.
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires the Company to report information regarding its exposure to various tax positions taken by the Company. The Company has determined whether any tax positions have met the recognition threshold and has measured the Company’s exposure to those tax positions. Management believes that the Company has adequately addressed all relevant tax positions and that there are no unrecorded tax liabilities. Any interest or penalties assessed to the Company are recorded in operating expenses. No interest or penalties from any taxing authorities were recorded in the accompanying consolidated financial statements. Federal, state, and local taxing authorities generally have the right to examine and audit the previous three years of tax returns filed.
	The Company is also required to reduce its tax basis of the investment in certain of the projects that generated the Federal NMTC or Federal Historic Rehabilitation tax credits by the amount of the credit generated in that year based on the taxable entity structure of the investee.
Noncontrolling Interests	'
	Noncontrolling Interests
	During 2012, the $1.6 million of noncumulative, perpetual preferred stock held by unrelated parties of the Bank was redeemed and noncontrolling interests were reduced by that amount. The stock had been assumed by the Bank in a prior acquisition.
	Noncontrolling interests also include $2,000, $1,000, and $2,000 at December 31, 2013, 2012, and 2011, respectively, of common stock held by unrelated parties in various tax credit-related subsidiaries, which have activities solely related to generating the tax credits.
Investments in Real Estate Properties	'
	Investments in Real Estate Properties
	FNBC CDC invests in real estate properties, which are carried at cost. Costs of construction are capitalized during the construction period and do not include interest. The Company periodically obtains as-is appraisals to determine the recoverability of its investments for which it intends to sell. For properties the Company intends to hold, the Company assesses recoverability based on the cash flows of the underlying properties.
Investments in Tax Credit Entities	'
	Investments in Tax Credit Entities
	As part of its Community Reinvestment Act responsibilities and due to their favorable economics, the Company invests in tax credit-motivated projects primarily in the markets it serves. These projects are directed at tax credits issued under Low-Income Housing, Federal Historic Rehabilitation (Historic), and Federal New Markets Tax Credits. The Company generates its returns on tax credit motivated projects through the receipt of federal, and if applicable, state tax credits. The federal tax credits are recorded as an offset to the income tax provision in the year that they are earned under federal income tax law – over 10 to 15 years, beginning in the year in which rental activity commences for Low-Income Housing credits, or 10 years beginning in the year of the issuance of the certificate of occupancy for Historic credits, and over 7 years for Federal NMTC upon the investment of funds into the qualifying project. These credits, if not used in the tax return for the year of origination, can be carried forward for 20 years.
	For Low-Income Housing and Historic credits, the Company invests in a tax credit entity, usually a limited liability company, which owns the real estate. The Company receives a 99.9% nonvoting interest in the entity that must be retained during the compliance period for the credits (15 years forLow-Income Housing credits and 5 years for Historic credits). In most cases, the Company’s interest in the entity is generally reduced from a 99.9% interest to a 10% to 25% interest at the end of the compliance period. Control of the tax credit entity rests in the 0.1% interest general partner, who has the power and authority to make decisions that impact economic performance of the project and is required to oversee and manage the project. Due to the lack of any voting, economic, or managerial control, and due to the contractual reduction in its investment, the Company accounts for its investment by amortizing its investment, beginning at the issuance of the certificate of occupancy of the project, over the compliance period, as management believes any potential residual value in the real estate will have limited value.
	For Federal NMTC, a different structure is required by federal tax law. In order to distribute Federal NMTC, the federal government allocates such credits to CDEs. The Company invests in both CDEs formed by unaffiliated parties and in CDEs formed by the Company. Projects can be commercial or real estate operations and are qualified by their location in low- to moderate-income areas or by their employment of, or service to, low- to moderate-income citizens. A CDE, in most cases, creates a special-purpose subsidiary for the project through which the credits are allocated and through which the proceeds from the tax credit investor and a leverage lender, if applicable, flow through to the project, which in turn generate the credit. The credits are calculated at 39% of the total project cost at the rate of 5% for the first three years and 6% for the next four years. Federal tax law requires special terms benefitting the qualified project, which can include complete or partial debt forgiveness at the end of the seven-year term or below-market interest rates. The Company expenses the cost of any benefits provided to the project over the seven-year compliance period. When the Company also has a loan, commonly called a leveraged loan, to the project, it is carried in loans, as the Company has normal credit exposure to the project and is repaid at the end of the compliance period (in general, the debt has no principal payments during the compliance period but the Company, in most cases, requires the project to fund a sinking fund over the compliance period to achieve the same risk reduction effect as if principal is being amortized).
	When the Company is the tax credit investor in a CDE formed by an unaffiliated party, it has no control of the applicable CDE, the CDE’s special-purpose subsidiary, or the qualified project entity. When a project is funded through FNBC CDE, the Company consolidates its CDE and the specifically formed special-purpose entities since it maintains control over these entities. As part of the activities of FNBC CDE, the Company makes investments in the CDE for purposes of providing equity to the projects sponsored by the FNBC CDE.
	The Company has the risk of credit recapture if the project fails during the compliance period for Low-Income Housing and Historic transactions. For Federal NMTC transactions, the risk of credit recapture exists if investment requirements are not maintained during the compliance period. Such events, although rare, are accounted for when they occur, and no such events have occurred to date.
Variable Interest Entities	'
	Variable Interest Entities
	VIEs are entities that, in general, either do not have equity investors with voting rights or that have equity investors that do not provide sufficient financial resources for the entity to support its activities. The Company uses VIEs in various legal forms to conduct normal business activities. The Company reviews the structure and activities of VIEs for possible consolidation.
	A controlling financial interest in a VIE is present when an enterprise has both the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits of the VIE that could potentially be significant to the VIE. A VIE often holds financial assets, including loans or receivables, real estate, or other property. The company with a controlling financial interest, known as the primary beneficiary, is required to consolidate the VIE. Noncontrolling variable interests in certain limited partnerships for which it does not absorb a majority of expected losses or receive a majority of expected residual returns that are not included in the accompanying consolidated financial statements. Refer to Notes 12 and 13 for further detail.
Stock-Based Compensation Plans	'
	Stock-Based Compensation Plans
	At December 31, 2013 and 2012, the Company had a stock-based employee compensation plan, which provides for the issuance of stock options and restricted stock. The Company accounts for stock-based employee compensation in accordance with the fair value recognition provisions of ASC 718, Compensation—Stock Compensation. Compensation cost is recognized as expense over the service period, which is generally the vesting period of the options and restricted stock. The expense is reduced for estimated forfeitures over the vesting period and adjusted for actual forfeitures as they occur. As a result, compensation cost for all share-based payments is reflected in net income as part of salaries and employee benefits in the accompanying consolidated statements of income. See Note 24 for additional information on the Company’s stock-based compensation plans.
Earnings Per Share	'
	Earnings Per Share
	Basic earnings per common share is computed based upon net income attributable to common shareholders divided by the weighted-average number of common shares outstanding during each period. Diluted earnings per common share is computed based upon net income, adjusted for dilutive participating securities, divided by the weighted-average number of common shares outstanding during each period, and adjusted for the effect of dilutive potential common shares calculated using the treasury stock method and the assumed conversion for any dilutive convertible securities. In determining net income attributable to common shareholders, the net income attributable to participating securities is excluded. During 2011, the Company issued Series C preferred stock, which is considered a participating security because it shares in any dividends paid to common shareholders. The assumed conversion of the Series C preferred stock is excluded from the calculation of diluted earnings per share due to the fact that the shares are contingently issuable and the contingency still existed at the end of the year.
Comprehensive Income	'
	Comprehensive Income
	Accounting principles generally require that recognized revenue, expenses, gains, and losses be included in net income. Although certain changes in assets and liabilities, such as unrealized gains and losses on available-for-sale securities and cash flow hedges, are reported as a separate component of the equity section of the balance sheet; such items, along with net income, are components of comprehensive income.
Segments	'
	Segments
	All of the Company’s banking operations are considered by management to be aggregated in one reportable operating segment. Because the overall banking operations comprise substantially all of the consolidated operations and none of the Company’s other subsidiaries, either individually or in the aggregate, meet quantitative materiality thresholds, no separate segment disclosures are presented in the accompanying consolidated financial statements.
Reclassifications	'
	Reclassifications
	Certain reclassifications have been made to prior period balances to conform to the current period presentation. Investment in short-term receivables was previously reported within investment securities available for sale in prior period consolidated balance sheets, and the related income was previously reported in interest income from investment securities in prior period consolidated statements of income.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	ASU No. 2011-11 and ASU No. 2013-01
	In December 2011, the FASB issued ASU No. 2011-11, Balance Sheet (Topic 210): Disclosures about Offsetting Assets and Liabilities. ASU 2011-11 provides new accounting guidance that eliminates offsetting of financial instruments disclosure differences between GAAP and IFRS. ASU 2013-01, Balance Sheet (Topic 210): Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities, clarifies the scope of ASU No. 2011-11. New disclosures will be required for recognized financial instruments, such as derivatives, repurchase agreements, and reverse repurchase agreements, that are either: (a) offset on the balance sheet in accordance with the FASB’s offsetting guidance, or (b) subject to an enforceable master netting arrangement or similar agreement, regardless of whether they are offset in accordance with the FASB’s offsetting guidance. The objective of the new disclosure requirements is to enable users of the financial statements to evaluate the effect or potential effect of netting arrangements on an entity’s financial position, including the effect or potential effect of rights of setoff associated with certain financial instruments and derivative instruments. This amended guidance will be applied retrospectively and is effective for fiscal years, and interim periods within those years, beginning on or after January 1, 2013. The adoption of this guidance, which involves disclosure only, did not impact the Company’s results of operations or financial position. The Company currently does net its financial instruments on its consolidated balance sheets.
	ASU No. 2012-06
	In October 2012, the FASB issued ASU No. 2012-06, Business Combinations (Topic 805): Subsequent Accounting for an Indemnification Asset Recognized at the Acquisition Date as a Result of a Government-Assisted Acquisition of a Financial Institution, which clarifies the applicable guidance for subsequently measuring an indemnification asset recognized in a government-assisted acquisition of a financial institution that includes a loss-sharing agreement. The ASU addresses the diversity in practice in the interpretation of the terms “on the same basis” and “contractual limitations” used in accounting guidance. Accounting principles require that an indemnification asset recognized at the acquisition date as a result of a government-assisted acquisition of a financial institution involving an indemnification agreement shall be subsequently measured on the same basis as the indemnified item. The provisions of this ASU clarify that, upon subsequent remeasurement of an indemnification asset, the effect of the change in expected cash flows of the indemnification agreement shall be amortized. Any amortization of changes in value is limited to the lesser of the contractual term of the indemnification agreement and the remaining life of the indemnified assets. The ASU does not affect the guidance relating to the recognition or initial measurement of an indemnification asset. The amendments in this ASU are effective for fiscal years after December 15, 2012, with early adoption permitted. The Company does not have an indemnification asset recorded and therefore, the adoption of this ASU did not have a material impact on the Company’s results of operations, financial position, or disclosures.
	ASU No. 2013-02
	In February 2013, the FASB issued ASU No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income, which requires the Company to report the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in net income in the Company’s consolidated statement of comprehensive income if the amount being reclassified is required under U.S. GAAP to be reclassified in its entirety to net income. The ASU does not change the current requirements for reporting net income or other comprehensive income in the consolidated financial statements of the Company, but does require the Company to provide information about the amounts reclassified out of accumulated other comprehensive income by component. The provisions of the ASU are effective prospectively beginning after December 15, 2013, with early adoption permitted. The adoption of this ASU is reflected in the accompanying consolidated statements of comprehensive income.
	ASU No. 2014-01
	In January 2014, the FASB issued ASU No. 2014-01, Investments-Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Qualified Affordable Housing Projects, which permits reporting entities to make an accounting policy election to account for their investments in qualified affordable housing projects using the proportional amortization method if certain conditions are met. Under the proportional amortization method, an entity amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as a component of income tax expense (benefit). This ASU applies to all reporting entities that invest in qualified affordable housing projects through limited liability entities that are flow-through entities for tax purposes. The provisions of this ASU should be applied retrospectively to all periods presented for periods beginning after December 15, 2014, with early adoption permitted. The Company is evaluating the adoption of this ASU and has not determined the impact on the Company’s financial condition or results of operations.
	ASU No. 2014-04
	In January 2014, the FASB issued ASU No. 2014-04, Receivables-Troubled Debt Restructurings by Creditors (Subtopic 310-40): Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure, which clarifies when an insubstance repossession or foreclosure occurs, that is, when a creditor should be considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan such that the loan receivable should be derecognized and the real estate property recognized. The ASU requires a creditor to reclassify a collateralized consumer mortgage loan to real estate property upon obtaining legal title to the residential real estate property, or the borrower conveying all interest in the residential real estate property through completion of a deed in lieu of foreclosure or similar legal agreement. The provisions of this ASU are effective for all periods beginning after December 15, 2014.The adoption of this guidance is not expected to have a material impact on the Company’s financial condition or results of operations.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Estimated Useful Life of Assets	'
	Depreciation is computed using the straight-line method over the estimated life of each respective type of asset as follows:
	Buildings	40 years
	Furniture, fixtures, and equipment	5–15 years

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Schedule of Computation of Basic and Diluted Net Income Per Common Share	'
	The following sets forth the computation of basic net income per common share and diluted net income per common share:
		Year Ended December 31,
	(In thousands, except per share data)	2013		2012		2011
	Basic: Income available to common shareholders	$	40,564	$	28,430	$	18,068
	Less: Income attributable to participating securities (Series C preferred stock)		1,980		1,999		1,304
	Income attributable to common shareholders	$	38,584	$	26,431	$	16,764
	Weighted-average common shares outstanding		16,203,919		12,952,751		10,794,639
	Basic earnings per share	$	2.38	$	2.04	$	1.55
	Diluted: Income attributable to common shareholders	$	38,584	$	26,431	$	16,764
	Weighted-average common shares outstanding		16,203,919		12,952,751		10,794,639
	Effect of dilutive securities:
	Stock options outstanding		337,371		108,537		37,754
	Warrants		82,824		51,503		28,535
	Weighted-average common shares outstanding – assuming dilution		16,624,114		13,112,791		10,860,928
	Diluted earnings per share	$	2.32	$	2.02	$	1.54

Investment_Securities_Tables

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2013
Investments Debt And Equity Securities [Abstract]	'
Summary of Amortized Cost and Market Values of Investment Securities with Gross Unrealized Gains and Losses	'
	The amortized cost and market values of investment securities, with gross unrealized gains and losses, as of December 31, 2013 and December 31, 2012, were as follows (in thousands):
		Amortized			Gross		Gross Unrealized Losses						Estimated
		Cost			Unrealized								Market Value
					Gains		Less Than			Greater Than
							One Year			One Year
	December 31, 2013
	Available for sale:
	U.S. government agency securities	$	163,964		$	81	$	(10,991	)	$	(1,731	)	$	151,323
	U.S. Treasury securities		13,022			—		(873	)		—			12,149
	Municipal securities		23,240			140		(213	)		—			23,167
	Mortgage-backed securities		57,010			447		(1,897	)		(16	)		55,544
	Corporate bonds		37,023			395		(1,677	)		(205	)		35,536
		$	294,259		$	1,063	$	(15,651	)	$	(1,952	)	$	277,719
	Held to maturity:
	Municipal securities	$	44,294		$	94	$	(398	)	$	—		$	43,990
	Mortgage-backed securities		50,610			12		(3,646	)		—			46,976
		$	94,904		$	106	$	(4,044	)	$	—		$	90,966
	December 31, 2012
	Available for sale:
	U.S. government agency securities	$	128,665		$	83	$	(1	)	$	—		$	128,747
	U.S. Treasury securities		10,040			5		—			—			10,045
	Municipal securities		61,907			884		(44	)		—			62,747
	Mortgage-backed securities		152,481			1,615		(254	)		—			153,842
	Corporate bonds		49,912			410		(348	)		—			49,974
		$	403,005		$	2,997	$	(647	)	$	—		$	405,355
Summary of Investment Security Issuers	'
	At December 31, 2013, the Company’s exposure to three investment security issuers individually exceeded 10% of shareholders’ equity (in thousands):
		Amortized			Estimated
		Cost			Market Value
	FHLB	$	83,052		$	78,729
	Federal National Mortgage Association (Fannie Mae)		81,693			75,421
	Federal Home Loan Mortgage Corporation (Freddie Mac)		62,281			57,860
		$	227,026		$	212,010
Summary of Amortized Cost and Estimated Market Values by Contractual Maturity of Investment Securities	'
	The amortized cost and estimated market values by contractual maturity of investment securities as of December 31, 2013 and December 31, 2012 are shown in the following table (in thousands). Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.
		December 31, 2013								December 31, 2012
		Weighted			Amortized		Estimated			Weighted			Amortized		Estimated
		Average			Cost		Market Value			Average			Cost		Market Value
		Yield								Yield
	Available for sale:
	Due in one year or less		1.39	%	$	12,340	$	12,368			1.04	%	$	119,657	$	119,753
	Due after one year through five years		2.58			64,790		65,038			1.96			106,676		108,349
	Due after five years through ten years		2.12			180,362		168,243			2.36			130,396		130,958
	Due after ten years		3.17			36,767		32,070			2.6			46,276		46,295
	Total securities		2.3	%	$	294,259	$	277,719			1.67	%	$	403,005	$	405,355
	Held to maturity:
	Due in one year or less		1.76	%	$	1,007	$	1,007			—	%	$	—	$	—
	Due after one year through five years		2.6			18,101		17,539			—			—		—
	Due after five years through ten years		3.7			37,591		37,137			—			—		—
	Due after ten years		3.41			38,205		35,283			—			—		—
	Total securities		3.35	%	$	94,904	$	90,966			—	%	$	—	$	—
Summary of Securities in Other Assets, at Cost	'
	At December 31, 2013 and 2012, the Company included the following securities in other assets, at cost, in the accompanying consolidated balance sheets (in thousands):
		2013			2012
	FHLB stock	$	1,099		$	2,938
	First National Bankers Bankshares, Inc. (FNBB) stock		600			600
	Other investments		4,853			3,200
	Total equity securities	$	6,552		$	6,738

Loans_Tables

Loans (Tables)	12 Months Ended
	Dec. 31, 2013
Receivables [Abstract]	'
Summary of Major Classifications of Loans	'
	Major classifications of loans at December 31, 2013 and December 31, 2012 were as follows (in thousands):
			December 31,			December 31,
			2013			2012
	Commercial real estate loans:
	Construction		$	203,369		$	159,999
	Mortgage(1)			1,118,048			983,164
				1,321,417			1,143,163
	Consumer real estate loans:
	Construction			8,986			7,738
	Mortgage			115,307			102,699
				124,293			110,437
	Commercial and industrial loans			868,469			622,105
	Loans to individuals, excluding real estate			16,345			14,000
	Nonaccrual loans			16,396			21,083
	Other loans			10,857			11,429
				2,357,777			1,922,217
	Less allowance for loan losses			(32,143	)		(26,977	)
	Loans, net		$	2,325,634		$	1,895,240
	(1)	Included in commercial real estate loans, mortgage, are owner-occupied real estate loans, of $364.9 million at December 31, 2013 and $345.4 million at December 31, 2012.
Summary of Changes in Allowance for Loan Losses	'
	A summary of changes in the allowance for loan losses during the years ended December 31, 2013, 2012, and 2011 is as follows (in thousands):
			2013			2012			2011
	Balance, beginning of period		$	26,977		$	18,122		$	12,508
	Provision charged to operations			9,800			11,035			8,010
	Charge-offs			(4,769	)		(2,561	)		(2,462	)
	Recoveries			135			381			66
	Balance, end of period		$	32,143		$	26,977		$	18,122
Summary of Allowance for Loan Losses and Recorded Investment in Loans	'
	The allowance for loan losses and recorded investment in loans, including loans acquired with deteriorated credit quality as of the dates indicated are as follows (in thousands):
			December 31, 2013
			Construction			Commercial			Consumer			Commercial			Other			Total
						Real Estate			Real Estate			and			Consumer
												Industrial
	Allowance for loan losses:
	Beginning balance		$	2,004		$	10,716		$	2,450		$	11,675		$	132		$	26,977
	Charge-offs			(46	)		(292	)		—			(4,229	)		(202	)		(4,769	)
	Recoveries			—			19			30			68			18			135
	Provision			832			3,337			176			5,163			292			9,800
	Ending balance		$	2,790		$	13,780		$	2,656		$	12,677		$	240		$	32,143
	Ending balances:
	Individually evaluated for impairment		$	42		$	1,639		$	183		$	2,091		$	—		$	3,955
	Collectively evaluated for impairment		$	2,748		$	12,141		$	2,473		$	10,586		$	240		$	28,188
	Loans receivable:
	Ending balance-total		$	212,430		$	1,128,181		$	117,653		$	883,111		$	16,402		$	2,357,777
	Ending balances:
	Individually evaluated for impairment		$	309		$	9,811		$	2,990		$	4,005		$	—		$	17,115
	Collectively evaluated for impairment		$	212,121		$	1,118,370		$	114,663		$	879,106		$	16,402		$	2,340,662
			December 31, 2012
			Construction			Commercial			Consumer			Commercial			Other			Total
						Real Estate			Real Estate			and			Consumer
												Industrial
	Allowance for loan losses:
	Beginning balance		$	722		$	9,871		$	1,519		$	5,928		$	82		$	18,122
	Charge-offs			—			(1,262	)		(59	)		(1,068	)		(172	)		(2,561	)
	Recoveries			16			132			22			153			58			381
	Provision			1,266			1,975			968			6,662			164			11,035
	Ending balance		$	2,004		$	10,716		$	2,450		$	11,675		$	132		$	26,977
	Ending balances:
	Individually evaluated for impairment		$	176		$	951		$	362		$	5,453		$	—		$	6,942
	Collectively evaluated for impairment		$	1,828		$	9,765		$	2,088		$	6,222		$	132		$	20,035
	Loans receivable:
	Ending balance-total		$	168,544		$	988,994		$	103,516		$	647,090		$	14,073		$	1,922,217
	Ending balances:
	Individually evaluated for impairment		$	799		$	5,203		$	1,178		$	14,133		$	—		$	21,313
	Collectively evaluated for impairment		$	167,745		$	983,791		$	102,338		$	632,957		$	14,073		$	1,900,904
Summary of Credit Quality Indicators on Company's Loan Portfolio	'
	Credit quality indicators on the Company’s loan portfolio, including loans acquired with deteriorated credit quality, as of the dates indicated were as follows (in thousands):
			31-Dec-13
			Pass and			Special			Substandard			Doubtful			Total
			Pass/Watch			Mention
	Construction		$	197,951		$	4		$	14,475		$	—		$	212,430
	Commercial real estate			1,073,339			1,720			53,122			—			1,128,181
	Consumer real estate			113,037			185			4,431			—			117,653
	Commercial and industrial			873,547			17			9,547			—			883,111
	Other consumer			16,251			9			142			—			16,402
	Total loans		$	2,274,125		$	1,935		$	81,717		$	—		$	2,357,777
			31-Dec-12
			Pass and			Special			Substandard			Doubtful			Total
			Pass/Watch			Mention
	Construction		$	146,748		$	3,258		$	18,538		$	—		$	168,544
	Commercial real estate			962,694			1,698			24,602			—			988,994
	Consumer real estate			101,334			751			1,431			—			103,516
	Commercial and industrial			620,851			18			14,984			11,237			647,090
	Other consumer			13,859			13			201			—			14,073
	Total loans		$	1,845,486		$	5,738		$	59,756		$	11,237		$	1,922,217
Age Analysis of Past Due Loans Including Loans Acquired with Deteriorated Credit Quality	'
	Age analysis of past due loans, including loans acquired with deteriorated credit quality, as of the dates indicated were as follows (in thousands):
			December 31, 2013
			Greater Than			90 Days and			Total Past			Current Loans			Total Loans
			30 and Fewer			Greater			Due
			Than 90 Days			Past Due
			Past Due
	Real estate loans:
	Construction		$	15		$	75		$	90		$	212,340		$	212,430
	Commercial real estate			2,935			7,642			10,577			1,117,604			1,128,181
	Consumer real estate			1,260			2,166			3,426			114,227			117,653
	Total real estate loans			4,210			9,883			14,093			1,444,171			1,458,264
	Other loans:
	Commercial and industrial			3,076			1,281			4,357			878,754			883,111
	Other consumer			488			207			695			15,707			16,402
	Total other loans			3,564			1,488			5,052			894,461			899,513
	Total loans		$	7,774		$	11,371		$	19,145		$	2,338,632		$	2,357,777
			31-Dec-12
			Greater Than			90 Days and			Total Past			Current Loans			Total Loans
			30 and Fewer			Greater			Due
			Than 90 Days			Past Due
			Past Due
	Real estate loans:
	Construction		$	—		$	751		$	751		$	167,793		$	168,544
	Commercial real estate			960			5,914			6,874			982,120			988,994
	Consumer real estate			483			651			1,134			102,382			103,516
	Total real estate loans			1,443			7,316			8,759			1,252,295			1,261,054
	Other loans:
	Commercial and industrial			671			2,197			2,868			644,222			647,090
	Other consumer			25			54			79			13,994			14,073
	Total other loans			696			2,251			2,947			658,216			661,163
	Total loans		$	2,139		$	9,567		$	11,706		$	1,910,511		$	1,922,217
Summary of Information Pertaining to Impaired Loans	'
	The following is a summary of information pertaining to impaired loans, which consist primarily of nonaccrual loans. This table excludes loans acquired with deteriorated credit quality. Acquired impaired loans are generally not subject to individual evaluation for impairment and are not reported with impaired loans or troubled debt restructurings, even if they would otherwise qualify for such treatment. Impaired loans as of the periods indicated were as follows (in thousands):
			December 31, 2013
			Recorded			Contractual			Related			Average			Interest
			Investment			Balance			Allowance			Recorded			Income
												Investment			Recognized
	With no related allowance recorded:
	Construction		$	—		$	—		$	—		$	24		$	—
	Commercial real estate			4,261			4,469			—			3,063			110
	Consumer real estate			1,973			1,999			—			1,254			—
	Commercial and industrial			1,099			1,116			—			977			40
	Total		$	7,333		$	7,584		$	—		$	5,318		$	150
	With an allowance recorded:
	Construction		$	309		$	309		$	42		$	530		$	23
	Commercial real estate			5,550			7,428			1,639			4,445			59
	Consumer real estate			1,017			1,046			183			831			21
	Commercial and industrial			2,906			2,941			2,091			8,093			10
	Total		$	9,782		$	11,724		$	3,955		$	13,899		$	113
	Total impaired loans:
	Construction		$	309		$	309		$	42		$	554		$	23
	Commercial real estate			9,811			11,897			1,639			7,508			169
	Consumer real estate			2,990			3,045			183			2,085			21
	Commercial and industrial			4,005			4,057			2,091			9,070			50
	Total		$	17,115		$	19,308		$	3,955		$	19,217		$	263
			December 31, 2012
			Recorded			Contractual			Related			Average			Interest
			Investment			Balance			Allowance			Recorded			Income
												Investment			Recognized
	With no related allowance recorded:
	Construction		$	48		$	48		$	—		$	1,146		$	3
	Commercial real estate			1,864			1,984			—			2,478			30
	Consumer real estate			534			534			—			639			2
	Commercial and industrial			854			874			—			1,030			54
	Total		$	3,300		$	3,440		$	—		$	5,293		$	89
	With an allowance recorded:
	Construction		$	751		$	751		$	176		$	376		$	14
	Commercial real estate			3,339			3,367			548			1,855			47
	Consumer real estate			644			644			765			819			9
	Commercial and industrial			13,279			13,280			5,453			6,781			389
	Total		$	18,013		$	18,042		$	6,942		$	9,831		$	459
	Total impaired loans:
	Construction		$	799		$	799		$	176		$	1,522		$	17
	Commercial real estate			5,203			5,351			548			4,333			77
	Consumer real estate			1,178			1,178			765			1,458			11
	Commercial and industrial			14,133			14,154			5,453			7,811			443
	Total		$	21,313		$	21,482		$	6,942		$	15,124		$	548
Summary of Nonaccrual Loans	'
	A summary of information pertaining to nonaccrual loans as of the periods indicated is as follows (in thousands):
			2013			2012
	Nonaccrual loans:
	Construction		$	75		$	806
	Commercial real estate			10,133			5,831
	Consumer real estate			2,347			818
	Commercial and industrial			3,784			13,556
	Other consumer			57			72
			$	16,396		$	21,083
Changes in Carrying Amount of Accretable Yield for Purchased Credit Impaired Loans Acquired	'
	The following is a summary of changes in the accretable yields of acquired loans as of the years ended December 31, 2013 and 2012 (in thousands):
			2013			2012
	Balance, beginning of period		$	628		$	1,374
	Acquisition			—			—
	Net transfers from nonaccretable difference to accretable yield			45			361
	Accretion			(503	)		(1,107	)
	Balance, end of period		$	170		$	628
Summary of Company's TDRs	'
	Information about the Company’s TDRs as of December 31, 2013 and December 31, 2012, is presented in the following tables (in thousands):
	Year Ended December 31, 2013		Current			Greater			Nonaccrual			Total Loans
						Than 30			TDRs
						Days Past
						Due
	Real estate loans:
	Construction		$	309		$	—		$	—		$	309
	Commercial real estate			357			—			102			459
	Consumer real estate			625			—			136			761
	Total real estate loans			1,291			—			238			1,529
	Other loans:
	Commercial and industrial			337			—			—			337
	Total loans		$	1,628		$	—		$	238		$	1,866
	Year Ended December 31, 2012
	Real estate loans:
	Construction		$	47		$	—		$	—		$	47
	Commercial real estate			268			—			982			1,250
	Consumer real estate			655			—			—			655
	Total real estate loans			970			—			982			1,952
	Other loans:
	Commercial and industrial			384			—			—			384
	Total loans		$	1,354		$	—		$	982		$	2,336
Summary of Information on TDRs Modification	'
	The following table provides information on how the TDRs were modified during the years ended December 31, 2013 and 2012 (in thousands):
			2013			2012
	Maturity and interest rate adjustment		$	925		$	609
	Movement to or extension of interest rate-only payments			597			1,333
	Other concession(s)(1)			344			394
	Total		$	1,866		$	2,336
	-1	Other concessions include concessions or a combination of concessions, other than maturity extensions and interest rate adjustments.
Summary of Information Pertaining to Modified Terms of Loans	'
	A summary of information pertaining to modified terms of loans, as of the dates indicated, is as follows (in thousands):
			December 31, 2013
			Number of			Pre-			Post-
			Contracts			Modification			Modification
						Outstanding			Outstanding
						Recorded			Recorded
						Investment			Investment
	Troubled debt restructuring:
	Construction			2		$	309		$	309
	Commercial real estate			3			459			459
	Consumer real estate			3			761			761
	Commercial and industrial			1			337			337
				9		$	1,866		$	1,866
			31-Dec-12
			Number of			Pre-Modification			Post-
			Contracts			Outstanding			Modification
						Recorded			Outstanding
						Investment			Recorded
									Investment
	Troubled debt restructuring:
	Construction			1		$	47		$	47
	Commercial real estate			2			1,250			1,250
	Consumer real estate			3			655			655
	Commercial and industrial			1			384			384
				7		$	2,336		$	2,336

Premises_and_Equipment_Tables

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2013
Property Plant And Equipment [Abstract]	'
Schedule of Premises and Equipment	'
	Premises and equipment consisted of the following at December 31 (in thousands):
		2013		2012
	Buildings and leasehold improvements	$	35,765	$	30,716
	Land		10,399		8,940
	Furniture, fixtures, and equipment		13,773		11,536
	Construction in progress		1,542		3,475
	Total premises and equipment		61,479		54,667
	Less accumulated depreciation and amortization		10,305		7,600
	Total premises and equipment, net	$	51,174	$	47,067

Goodwill_and_Other_Acquired_In1

Goodwill and Other Acquired Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Goodwill And Intangible Assets Disclosure [Abstract]	'
Changes to Carrying Amount of Goodwill	'
	Changes to the carrying amount of goodwill for the years ended December 31, 2013 and 2012 are provided in the following table (in thousands):
	Balance at December 31, 2011	$	4,808
	Goodwill acquired during the year		—
	Balance at December 31, 2012		4,808
	Goodwill acquired during the year		—
	Balance at December 31, 2013	$	4,808
Schedule of Finite Lived Intangible Assets Future Amortization Expense	'
	The estimated amortization expense for the core deposit intangible asset is as follows as of December 31, 2013 (in thousands):
	2014-2018	$	376
	2019 and thereafter		2,272

Deposits_Tables

Deposits (Tables)	12 Months Ended
	Dec. 31, 2013
Banking And Thrift [Abstract]	'
Summary of Scheduled Interest Bearing Deposits	'
	Interest-bearing deposits at December 31, 2013 and 2012 consisted of the following (in thousands):
		2013		2012
	Savings	$	53,779	$	45,295
	Money market accounts		655,173		410,928
	Negotiable order of withdrawal (NOW) accounts		511,620		437,542
	Certificates of deposit over $100,000		820,374		698,007
	Certificates of deposit under $100,000		398,781		437,218
		$	2,439,727	$	2,028,990
Summary of Scheduled Maturities of Time Deposits	'
	The certificates of deposit mature as follows as of December 31, 2013 (in thousands):
	2014	$	550,700
	2015		282,427
	2016		194,253
	2017		74,821
	2018		115,839
	Thereafter		1,115
		$	1,219,155

ShortTerm_Borrowings_Tables

Short-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Summary of Short-Term Borrowings	'
	The following is a summary of short-term borrowings at December 31 (in thousands):
		2013		2012
	FNBB	$	8,425	$	21,800
	Total short-term borrowings	$	8,425	$	21,800
Summary of Unused Lines of Credit	'
	The following is a summary of unused lines of credit at December 31 (in thousands):
		2013		2012
	FNBB	$	30,000	$	30,000
	JPMorgan Chase		30,000		30,000
	FHLB		432,181		338,032
	PNC Bank		15,000		15,000
	Comerica		20,000		—
	Total unused lines of credit	$	527,181	$	413,032

LongTerm_Borrowings_Tables

Long-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Summary of Long-Term Borrowings	'
	The following is a summary of long-term borrowings at December 31 (in thousands):
		2013		2012
	FNBB	$	110	$	220
	Credit Suisse Securities (USA) LLC		55,000		55,000
	Comerica		—		20,000
	Total long-term borrowings	$	55,110	$	75,220
Summary of Principal Payments	'
	Principal payments by year on these borrowings are as follows (in thousands):
	2014	$	15,110
	2015		40,000
	Total long-term borrowings	$	55,110

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Summary of Income Tax Benefit on Income from Operations	'
	The income tax benefit on the income from operations for the years ended December 31, 2013, 2012, and 2011 was as follows (in thousands):
		2013			2012			2011
	Current tax expense	$	186		$	—		$	—
	Deferred tax benefit		(19,937	)		(7,565	)		(5,407	)
	Total tax benefit	$	(19,751	)	$	(7,565	)	$	(5,407	)
Schedule of Income Taxes Reconciliation with Federal Statutory Rates	'
	The amount of taxes in the accompanying consolidated statements of income is different from the expected amount using statutory federal income tax rates primarily due to the effect of various tax credits.
		Year Ended December 31,
		2013			2012			2011
	Federal tax expense at statutory rates	$	7,406		$	7,481		$	5,019
	Tax credits		(28,421	)		(17,100	)		(13,142	)
	Tax credit-basis reduction		2,019			2,767			3,112
	Tax-exempt income		(832	)		(655	)		(509	)
	Change in deferred rate		—			—			293
	Disallowed interest expense		117			99			101
	Other		(40	)		(157	)		(281	)
	Income tax benefit	$	(19,751	)	$	(7,565	)	$	(5,407	)
Summary of Significant Components of Deferred Tax Assets and Liabilities	'
	The components of the Company’s deferred tax assets and liabilities as of December 31 are presented below (in thousands):
		Year Ended December 31,
		2013			2012
	Deferred tax assets:
	Loan loss reserve	$	11,250		$	9,397
	Tax credit carryforwards		65,216			37,353
	NOL carryforward		7,317			4,030
	Stock-based compensation		684			436
	Deferred compensation		91			91
	Securities available for sale		8,880			1,563
	Other real estate		250			269
	Basis difference in assumed liabilities		338			1,701
	Other		373			355
	Total deferred tax assets		94,399			55,195
	Deferred tax liabilities:
	Fixed assets		6,546			5,867
	Deferred loan costs		5,157			4,414
	Amortizable costs		1,477			1,697
	State tax credits		1,155			669
	Investments in tax credit entities		28,097			25,789
	Other		776			170
	Total deferred tax liabilities		43,208			38,606
	Net deferred tax assets	$	51,191		$	16,589

Shareholders_Equity_Tables

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Schedule of Annualized Dividend Rate	'
	The dividend rate, as a percentage of the liquidation amount, fluctuates, while the Series D preferred stock is outstanding based upon changes in the level of qualified small business lending (QSBL) by the Company from its average level of QSBL at each of the four quarter-ends leading up to June 30, 2010 (Baseline), as follows:
	Dividend Period		Annualized
	Beginning	Ending	Dividend Rate
	August 4, 2011	September 30, 2011	1.54%
	October 1, 2011	December 31, 2011	1.00%
	January 1, 2012	March 31, 2012	1.00%
	April 1, 2012	June 30, 2012	1.00%
	July 1, 2012	December 31, 2013	1.000% to 5.000%
	January 1, 2014	February 3, 2016	1.000% to 7.000%
	February 4, 2016	Redemption	9.00%

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Summary of Changes in Accumulated Other Comprehensive Income (Loss)	'
	The components of accumulated other comprehensive income and changes in those components are presented in the following table (in thousands):
		Cash Flow			Transfers of			Available for			Total
		Hedge			Available for			Sale
					Sale			Securities
					Securities to
					Held to
					Maturity
	Balance at January 1, 2013	$	(4,455	)	$	—		$	1,529		$	(2,926	)
	Other comprehensive income before income taxes:
	Net change in unrealized gain (loss)		3,694			—			(18,576	)		(14,882	)
	Transfer of net unrealized loss from available for sale to held to maturity, net of cumulative tax effect		—			(5,919	)		—			(5,919	)
	Reclassification of net gains realized and included in earnings		—			—			(316	)		(316	)
	Amortization of unrealized net loss on securities		—			211			—			211
	Income tax expense (benefit)		1,293			(1,998	)		(6,612	)		(7,317	)
	Balance at December 31, 2013	$	(2,054	)	$	(3,710	)	$	(10,751	)	$	(16,515	)
	Balance at January 1, 2012	$	—		$	—		$	1,795		$	1,795
	Other comprehensive income before income taxes:
	Net change in unrealized (loss) gain		(6,854	)		—			3,956			(2,898	)
	Reclassification of net gains realized and included in earnings		—			—			(4,324	)		(4,324	)
	Income tax (benefit)		(2,399	)		—			(102	)		(2,501	)
	Balance at December 31, 2012	$	(4,455	)	$	—		$	1,529		$	(2,926	)
	Balance at January 1, 2011	$	—		$	—		$	(1,062	)	$	(1,062	)
	Other comprehensive income before income taxes:
	Net change in unrealized gain		—			—			4,814			4,814
	Reclassification of net gains realized and included in earnings		—			—			(485	)		(485	)
	Income tax expense		—			—			1,472			1,472
	Balance at December 31, 2011	$	—		$	—		$	1,795		$	1,795

Capital_Requirements_and_Other1

Capital Requirements and Other Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2013
Text Block [Abstract]	'
Summary of Capital Amounts and Ratios	'
	The Company and the Bank’s actual capital amounts and ratios as of December 31 were as follows (in thousands):
		Actual					For Capital Adequacy					To Be Well Capitalized
							Purposes					Under Prompt Corrective
												Action Provisions
		Amount		Ratio			Amount		Ratio			Amount		Ratio
	December 31, 2013
	Tier 1 leverage capital:
	First NBC Bank Holding Company	$	375,355		11.76	%	$	127,625		4	%		NA		NA
	First NBC Bank		349,104		10.96	%		127,435		4	%	$	159,294		5	%
	Tier 1 risk-based capital:
	First NBC Bank Holding Company		375,355		13.26	%		113,254		4	%		NA		NA
	First NBC Bank		349,104		12.34	%		113,170		4	%	$	169,755		6	%
	Total risk-based capital:
	First NBC Bank Holding Company		407,648		14.4	%		226,508		8	%		NA		NA
	First NBC Bank		381,396		13.48	%		226,340		8	%	$	282,924		10	%
		Actual					For Capital Adequacy					To Be Well Capitalized
							Purposes					Under Prompt Corrective
												Action Provisions
		Amount		Ratio			Amount		Ratio			Amount		Ratio
	December 31, 2012
	Tier 1 leverage capital:
	First NBC Bank Holding Company	$	243,791		9.04	%	$	107,814		4	%		NA		NA
	First NBC Bank		256,848		9.91	%		103,704		4	%	$	129,630		5	%
	Tier 1 risk-based capital:
	First NBC Bank Holding Company		243,791		11.26	%		86,592		4	%		NA		NA
	First NBC Bank		256,848		11.88	%		86,457		4	%	$	129,686		6	%
	Total risk-based capital:
	First NBC Bank Holding Company		270,810		12.51	%		173,184		8	%		NA		NA
	First NBC Bank		283,867		13.13	%		172,914		8	%	$	216,143		10	%

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Summary of Weighted-Average Assumptions Used for Option Awards Granted	'
	The Company uses the Black-Scholes option pricing model to estimate the fair value of the stock options awards. The following weighted-average assumptions were used for option awards granted during the years ended December 31 of the periods indicated:
		2013			2012			2011
	Expected dividend yield		0	%		0	%		0	%
	Weighted-average expected volatility		36.68	%		35.33	%		31.5	%
	Weighted-average risk-free interest rate		1.73	%		1.25	%		2.87	%
	Expected option term (in years)		6			6.3			6
	Contractual term (in years)		10			10			10
	Weighted-average grant date fair value	$	5.22		$	5.49		$	4.33
Summary of Stock Option Activity	'
	The following table represents the activity related to stock options during the periods indicated.
		Number			Weighted-			Weighted-
		of Shares			Average			Average
					Exercise			Remaining
					Price			Contractual
								Term (Years)
	Options outstanding, December 31, 2010		215,000		$	10.04
	Granted		229,657			12.25
	Exercised		—			—
	Forfeited or expired		(999	)		12.23
	Options outstanding, December 31, 2011		443,658			11.11
	Granted		378,692			14.69
	Exercised		—			—
	Forfeited or expired		(13,333	)		14.43
	Options outstanding, December 31, 2012		809,017			11.81
	Granted		139,650			16.16
	Exercised		(76,966	)		10.39
	Forfeited or expired		(16,600	)		15.16
	Options outstanding, December 31, 2013		855,101		$	13.48			7
	Options exercisable, December 31, 2011		270,599		$	10.53
	Options exercisable, December 31, 2012		289,444		$	10.6
	Options exercisable, December 31, 2013		374,535		$	11.94			6
Summarized Information About Stock Options Outstanding by Range of Exercise Prices	'
	The following table presents weighted-average remaining life as of December 31, 2013 for options outstanding within the stated exercise prices:
		Options Outstanding									Options Exercisable
	Exercise Price Range	Number			Weighted-			Weighted-			Number		Weighted-
	Per Share	of Shares			Average			Average			of Shares		Average
					Exercise			Remaining					Exercise
					Price			Life					Price
								(Years)
	$10.00-$12.70		368,181		$	11.35			5			292,074	$	11.11
	$14.20-$14.88		351,870			14.68			8			82,461		14.88
	$15.88-$23.68		135,050			16.17			9			—		—
	Total Options		855,101		$	13.48			7			374,535	$	11.94

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Summary of Annual Rental Payments	'
	At December 31, 2013, the minimum annual rental payments to be made under the noncancelable leases are as follows (in thousands):
	Year ending December 31:
	2014	$	3,119
	2015		2,993
	2016		3,011
	2017		3,018
	2018		2,697
	Thereafter		41,259
		$	56,097
Summary of Total Notional Amount of Loan Commitments and Standby Letters of Credit	'
	The following is a summary of the total notional amount of loan commitments and standby letters of credit outstanding at December 31, 2013 and 2012 (in thousands):
		2013		2012
	Standby letters of credit	$	106,467	$	92,274
	Unused loan commitments		268,760		256,294
		$	375,227	$	348,568

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Carrying Value and Fair Value Measurements of Financial Assets and Liabilities on Recurring Basis	'
	The Company has segregated all financial assets and liabilities that are measured at fair value on a recurring basis into the most appropriate level within the fair value hierarchy, based on the inputs used to determine the fair value at the measurement date in the tables below (in thousands):
				December 31, 2013
				Fair Value Measurement Using
		Total		Quoted Prices		Significant		Significant
				in Active		Other		Unobservable
				Markets for		Observable		Inputs
				Identical Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Assets
	Available for sale securities	$	277,719	$	—	$	277,719	$	—
	Derivative instruments		1,157		—		1,157	$	—
	Total	$	278,876	$	—	$	278,876	$	—
	Liabilities
	Derivative instruments	$	4,317	$	—	$	4,317	$	—
				31-Dec-12
				Fair Value Measurement Using
		Total		Quoted Prices		Significant		Significant
				in Active		Other		Unobservable
				Markets for		Observable		Inputs
				Identical Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Assets
	Available for sale securities	$	405,355	$	—	$	405,355	$	—
	Liabilities
	Derivative instruments	$	6,854	$	—	$	6,854	$	—
Carrying Value and Fair Value Measurements of Financial Assets and Liabilities on Non Recurring Basis	'
	The Company has segregated all financial assets and liabilities that are measured at fair value on a nonrecurring basis into the most appropriate level within the fair value hierarchy based on the inputs used to determine the fair value at the measurement date in the tables below (in thousands):
				December 31, 2013
				Fair Value Measurement Using
		Total		Quoted Prices		Significant		Significant
				in Active		Other		Unobservable
				Markets for		Observable		Inputs
				Identical Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Assets
	Loans	$	9,782	$	—	$	—	$	9,782
	OREO		2,390		—		—		2,390
		$	12,172	$	—	$	—	$	12,172
				31-Dec-12
				Fair Value Measurement Using
		Total		Quoted Prices		Significant		Significant
				in Active		Other		Unobservable
				Markets for		Observable		Inputs
				Identical Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Assets
	Loans	$	21,313	$	—	$	—	$	21,313
	OREO		5,434		—		—		5,434
		$	26,747	$	—	$	—	$	26,747
Carrying Value and Fair Value Measurements of Financial Instruments	'
	The estimated fair values of the Company’s financial instruments were as follows as of the dates indicated (in thousands):
		Fair Value Measurements at December 31, 2013
		Carrying		Total		Level 1		Level 2		Level 3
		Amount
	Financial Assets:
	Cash and due from banks	$	28,140	$	28,140	$	28,140	$	—	$	—
	Short-term investments		3,502		3,502		3,502		—		—
	Investment in short-term receivables		246,817		246,817		246,817
	Investment securities available for sale		277,719		277,719		—		277,719		—
	Investment securities held to maturity		94,904		90,966				90,966
	Loans and loans held for sale		2,364,354		2,344,475		—		—		2,344,475
	Cash surrender value of bank-owned life insurance		26,187		26,187		—		26,187		—
	Derivative instruments		1,157		1,157		—		1,157		—
	Financial Liabilities:
	Deposits, noninterest-bearing		291,080		291,080		—		291,080		—
	Deposits, interest-bearing		2,439,727		2,380,985		—		—		2,380,985
	Short-term borrowings and repurchase agreements		84,382		84,382		—		84,382		—
	Long-term borrowings		55,110		55,616		—		—		55,616
	Derivative instruments		4,317		4,317		—		4,317		—
		Fair Value Measurements at December 31, 2012
		Carrying		Total		Level 1		Level 2		Level 3
		Amount
	Financial Assets:
	Cash and due from banks	$	26,471	$	26,471	$	26,471	$	—	$	—
	Short-term investments		9,541		9,541		9,541		—		—
	Investment in short-term receivables		81,044		81,044		81,044
	Investment securities available for sale		405,355		405,355		—		405,355		—
	Loans and loans held for sale		1,948,077		1,939,622		—		—		1,939,622
	Cash surrender value of bank-owned life insurance		25,506		25,506		—		25,506		—
	Financial Liabilities:
	Deposits, noninterest-bearing		239,538		239,538		—		239,538		—
	Deposits, interest-bearing		2,028,990		2,035,696		—		—		2,035,696
	Short-term borrowings and repurchase agreements		58,087		58,087		—		58,087		—
	Long-term borrowings		75,220		77,870		—		—		77,870
	Derivative instruments		6,854		6,854		—		6,854		—

Parent_Company_Only_Financial_1

Parent Company Only Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2013
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]	'
Schedule Of Balance Sheet	'
	Balance Sheets
		December 31,
	(in thousands)	2013			2012
	Assets
	Cash and due from banks	$	23,990		$	3,709
	Goodwill		841			841
	Investments in subsidiaries		355,068			260,618
	Other assets		2,123			3,157
	Total assets	$	382,022		$	268,325
	Liabilities and shareholders’ equity
	Long-term borrowings	$	110		$	20,220
	Other liabilities		53			4
	Total liabilities		163			20,224
	Total shareholders’ equity		381,859			248,101
	Total liabilities and shareholders’ equity	$	382,022		$	268,325
Schedule Of Statement of Income	'
	Statements of Income
		Year Ended December 31,
	(in thousands)	2013			2012			2011
	Operating income
	Interest income	$	—		$	—		$	—
	Dividend from bank subsidary		2,000			—			—
	Total operating income		2,000			—			—
	Operating expense
	Interest expense		424			11			14
	Other expense		856			431			188
	Total operating expense		1,280			442			202
	Income (loss) before income tax benefit and increase in equity in undistributed earnings of subsidiaries		720			(442	)		(202	)
	Income tax benefit		(448	)		(155	)		(71	)
	Income (loss) before equity in undistributed earnings of subsidiaries		1,168			(287	)		(131	)
	Equity in undistributed earnings of subsidiaries		39,743			29,227			19,571
	Net income		40,911			28,940			19,440
	Preferred stock dividends and discount accretion		(347	)		(510	)		(1,372	)
	Income available to common shareholders	$	40,564		$	28,430		$	18,068
Schedule Of Statement of Cash Flow	'
	Statements of Cash Flows
		Year Ended December 31,
	(in thousands)	2013			2012			2011
	Operating activities
	Net income	$	40,911		$	28,940		$	19,440
	Adjustments to reconcile net income to net cash (used in) provided by operating activities:
	Net income of subsidiaries		(39,743	)		(29,227	)		(19,571	)
	Deferred tax benefit		(448	)		(155	)		(71	)
	Stock compensation		1,155			97			715
	Changes in operating assets and liabilities:
	Change in other assets		1,481			(1,989	)		(762	)
	Change in other liabilities		50			—			3
	Net cash provided by (used in) operating activities		3,406			(2,334	)		(246	)
	Investing activities
	Capital contributed to subsidiary, net		(67,000	)		(16,600	)		(67,508	)
	Net cash used in investing activities		(67,000	)		(16,600	)		(67,508	)
	Financing activities
	Proceeds from long-term borrowings		—			20,000			—
	Repayment of borrowings		(20,110	)		(110	)		(110	)
	Repayment of preferred stock		—			—			(18,685	)
	Proceeds from sale of preferred stock, net of offering costs		—			—			58,518
	Proceeds from sale of common stock, net of offering costs		104,332			1,420			30,430
	Dividends paid		(347	)		(510	)		(792	)
	Net cash provided by financing activities		83,875			20,800			69,361
	Net change in cash, due from banks, and short-term investments		20,281			1,866			1,607
	Cash, due from banks, and short-term investments at beginning of period		3,709			1,843			236
	Cash, due from banks, and short-term investments at end of period	$	23,990		$	3,709		$	1,843

Consolidated_Quarterly_Results1

Consolidated Quarterly Results of Operations (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Summary of Quarterly Financial Data	'
	(dollars in thousands, except per share data)		First Quarter			Second			Third			Fourth
						Quarter			Quarter			Quarter
	Year Ended December 31, 2013
	Total interest income		$	28,580		$	29,034		$	31,973		$	34,437
	Total interest expense			8,893			9,779			10,150			10,326
	Net interest income			19,687			19,255			21,823			24,111
	Provision for loan losses			2,600			2,400			2,400			2,400
	Net interest income after provision for loan losses			17,087			16,855			19,423			21,711
	Noninterest income			2,817			2,738			2,461			5,400
	Noninterest expense			15,633			15,185			17,092			19,422
	Income before income taxes			4,271			4,408			4,792			7,689
	Income tax benefit			(4,013	)		(4,198	)		(5,673	)		(5,867	)
	Net income			8,284			8,606			10,465			13,556
	Less net income attributable to noncontrolling interest			—			—			—			—
	Net income attributable to Company			8,284			8,606			10,465			13,556
	Less preferred stock dividends			(95	)		(95	)		(62	)		(95	)
	Income available to common shareholders		$	8,189		$	8,511		$	10,403		$	13,461
	Earnings per common share-basic		$	0.59		$	0.51		$	0.55		$	0.71
	Earnings per common share-diluted		$	0.58		$	0.49		$	0.54		$	0.69
	(dollars in thousands, except per share data)		First Quarter			Second			Third			Fourth
						Quarter			Quarter			Quarter
	Year Ended December 31, 2012
	Total interest income		$	25,355		$	25,781		$	26,927		$	28,394
	Total interest expense			7,338			7,742			7,935			8,651
	Net interest income			18,017			18,039			18,992			19,743
	Provision for loan losses			2,635			1,800			1,800			4,800
	Net interest income after provision for loan losses			15,382			16,239			17,192			14,943
	Noninterest income			2,853			3,968			1,558			4,757
	Noninterest expense			13,738			13,863			13,586			13,820
	Income before income taxes			4,497			6,344			5,164			5,880
	Income tax (benefit) expense(1)			(1,926	)		(2,952	)		(3,130	)		443
	Net income			6,423			9,296			8,294			5,437
	Less net income attributable to noncontrolling interest			(118	)		—			(17	)		(375	)
	Net income attributable to Company			6,305			9,296			8,277			5,062
	Less preferred stock dividends			(95	)		(94	)		(226	)		(95	)
	Income available to common shareholders		$	6,210		$	9,202		$	8,051		$	4,967
	Earnings per common share-basic		$	0.45		$	0.66		$	0.58		$	0.36
	Earnings per common share-diluted		$	0.44		$	0.65		$	0.57		$	0.35
	-1	For the fourth quarter of 2012, the income tax expense was due to an adjustment for actual income tax expense (benefit) for the year ended 2012 due to a reduction in the number of tax credit projects that actually were funded and closed compared to the previous estimate.

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	Segment
Organization And Significant Accounting Policies [Line Items]	'	'	'
Derivatives at fair value, net	$0	'	'
Redemption of on cumulative perpetual preferred stock held by non-controlling interest	'	1,600,000	'
Non-controlling interest	$2,000	$1,000	$2,000
Tax credit Carry forward period	'20 years	'	'
Non voting interest	99.90%	'	'
Interest percentage for general partners	0.10%	'	'
Tax credit as Percentage of project cost	39.00%	'	'
Number of Reportable Segments	1	'	'
Minimum [Member]	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'
Interest at the end of compliance period	10.00%	'	'
Maximum [Member]	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'
Interest at the end of compliance period	25.00%	'	'
Low- Income Housing credits [Member]	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'
Compliance Period	'15 years	'	'
Low- Income Housing credits [Member] | Minimum [Member]	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'
Federal Tax Credit, Adjustment Period	'10 years	'	'
Low- Income Housing credits [Member] | Maximum [Member]	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'
Federal Tax Credit, Adjustment Period	'15 years	'	'
Historic credits [Member]	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'
Federal Tax Credit, Adjustment Period	'10 years	'	'
Compliance Period	'5 years	'	'
Federal NMTC [Member]	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'
Federal Tax Credit, Adjustment Period	'7 years	'	'
First Three Years [Member]	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'
Tax credit as Percentage of project cost	5.00%	'	'
Next Four Years [Member]	'	'	'
Organization And Significant Accounting Policies [Line Items]	'	'	'
Tax credit as Percentage of project cost	6.00%	'	'

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Estimated Useful Life Asset (Detail)	12 Months Ended
	Dec. 31, 2013
Minimum [Member] | Building [Member]	'
Property, Plant and Equipment [Line Items]	'
Property, plant and equipment, useful life (in years)	'40 years
Minimum [Member] | Furniture, Fixtures and Equipment [Member]	'
Property, Plant and Equipment [Line Items]	'
Property, plant and equipment, useful life (in years)	'5 years
Maximum [Member] | Furniture, Fixtures and Equipment [Member]	'
Property, Plant and Equipment [Line Items]	'
Property, plant and equipment, useful life (in years)	'15 years

Earnings_Per_Share_Schedule_of

Earnings Per Share - Schedule of Computation of Basic and Diluted Net Income Per Common Share (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Share [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Basic: Income available to common shareholders	$13,461	$10,403	$8,511	$8,189	$4,967	$8,051	$9,202	$6,210	$40,564	$28,430	$18,068
Less: Income attributable to participating securities (Series C preferred stock)	'	'	'	'	'	'	'	'	1,980	1,999	1,304
Income attributable to common shareholders	'	'	'	'	'	'	'	'	38,584	26,431	16,764
Weighted-average common shares outstanding	'	'	'	'	'	'	'	'	16,203,919	12,952,751	10,794,639
Basic earnings per share	$0.71	$0.55	$0.51	$0.59	$0.36	$0.58	$0.66	$0.45	$2.38	$2.04	$1.55
Diluted: Income attributable to common shareholders	'	'	'	'	'	'	'	'	$38,584	$26,431	$16,764
Weighted-average common shares outstanding	'	'	'	'	'	'	'	'	16,203,919	12,952,751	10,794,639
Stock options outstanding	'	'	'	'	'	'	'	'	337,371	108,537	37,754
Warrants	'	'	'	'	'	'	'	'	82,824	51,503	28,535
Weighted-average common shares outstanding - assuming dilution	'	'	'	'	'	'	'	'	16,624,114	13,112,791	10,860,928
Diluted earnings per share	$0.69	$0.54	$0.49	$0.58	$0.35	$0.57	$0.65	$0.44	$2.32	$2.02	$1.54

Earnings_Per_Share_Additional_

Earnings Per Share - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2011
Earnings Per Share [Abstract]	'	'	'
Warrants outstanding	87,059	125,000	87,059
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	264,000	'	'

Cash_and_Due_From_Banks_Additi

Cash and Due From Banks - Additional Information (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Cash And Cash Equivalents [Abstract]	'	'
Reserve Requirements	$10.10	$8.20

Investment_in_ShortTerm_Receiv1

Investment in Short-Term Receivables - Additional Information (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Receivables [Abstract]	'	'
Purchase receivable	$246,817	$81,044

Investment_Securities_Summary_

Investment Securities - Summary of Amortized Cost and Market Values of Investment Securities with Gross Unrealized Gains and Losses (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	$294,259	$403,005
Gross Unrealized Gains	1,063	2,997
Gross Unrealized Losses Less Than One Year	-15,651	-647
Gross Unrealized Losses Greater Than One Year	-1,952	'
Estimated Market Value	277,719	405,355
Amortized Cost	94,904	'
Gross Unrealized Gains	106	'
Gross Unrealized Losses Less Than One Year	-4,044	'
Gross Unrealized Losses Greater Than One Year	'	'
Estimated Market Value	94,904	'
Municipal securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	23,240	61,907
Gross Unrealized Gains	140	884
Gross Unrealized Losses Less Than One Year	-213	-44
Estimated Market Value	23,167	62,747
Amortized Cost	44,294	'
Gross Unrealized Gains	94	'
Gross Unrealized Losses Less Than One Year	-398	'
Gross Unrealized Losses Greater Than One Year	'	'
Estimated Market Value	43,990	'
Mortgage-backed securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	57,010	152,481
Gross Unrealized Gains	447	1,615
Gross Unrealized Losses Less Than One Year	-1,897	-254
Gross Unrealized Losses Greater Than One Year	-16	'
Estimated Market Value	55,544	153,842
Amortized Cost	50,610	'
Gross Unrealized Gains	12	'
Gross Unrealized Losses Less Than One Year	-3,646	'
Gross Unrealized Losses Greater Than One Year	'	'
Estimated Market Value	46,976	'
U.S. government agency securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	163,964	128,665
Gross Unrealized Gains	81	83
Gross Unrealized Losses Less Than One Year	-10,991	-1
Gross Unrealized Losses Greater Than One Year	-1,731	'
Estimated Market Value	151,323	128,747
U.S. Treasury securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	13,022	10,040
Gross Unrealized Gains	'	5
Gross Unrealized Losses Less Than One Year	-873	'
Estimated Market Value	12,149	10,045
Corporate bonds [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	37,023	49,912
Gross Unrealized Gains	395	410
Gross Unrealized Losses Less Than One Year	-1,677	-348
Gross Unrealized Losses Greater Than One Year	-205	'
Estimated Market Value	$35,536	$49,974

Investment_Securities_Addition

Investment Securities - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	Security	Security
Investments Debt And Equity Securities [Abstract]	'	'	'
Transfer of securities with fair value	$95.40	'	'
Accumulated other comprehensive income included net pre-tax unrealized losses	5.9	'	'
Number of securities in loss position	88	39	'
Securities with estimated market values	204.3	121.4	'
Proceeds from sales of securities	45.8	125.4	156.8
Gross gains realized	0.5	4.3	1.1
Gross losses realized	$0.20	$0	$0.60

Investment_Securities_Summary_1

Investment Securities - Summary of Investment Security Issuers (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Investments [Line Items]	'	'
Amortized Cost	$294,259	$403,005
Estimated Market Value	277,719	405,355
FHLB [Member]	'	'
Schedule of Investments [Line Items]	'	'
Amortized Cost	83,052	'
Estimated Market Value	78,729	'
Federal National Mortgage Association (Fannie Mae) [Member]	'	'
Schedule of Investments [Line Items]	'	'
Amortized Cost	81,693	'
Estimated Market Value	75,421	'
Federal Home Loan Mortgage Corporation (Freddie Mac) [Member]	'	'
Schedule of Investments [Line Items]	'	'
Amortized Cost	62,281	'
Estimated Market Value	$57,860	'

Investment_Securities_Summary_2

Investment Securities - Summary of Amortized Cost and Estimated Market Values by Contractual Maturity of Investment Securities (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Amortized Cost And Fair Value Debt Securities [Abstract]	'	'
Weighted average yield, Due in one year or less	1.39%	1.04%
Weighted average yield, Due after one year through five years	2.58%	1.96%
Weighted average yield, Due after five years through ten years	2.12%	2.36%
Weighted average yield, Due after ten years	3.17%	2.60%
Weighted average yield, Total securities	2.30%	1.67%
Weighted average yield, Due in one year or less	1.76%	'
Weighted average yield, Due after one year through five years	2.60%	'
Weighted average yield, Due after five years through ten years	3.70%	'
Weighted average yield, Due after ten years	3.41%	'
Weighted average yield, Total securities	3.35%	'
Amortized Cost, Due in one year or less	$12,340	$119,657
Amortized Cost, Due after one year through five years	64,790	106,676
Amortized Cost, Due after five years through ten years	180,362	130,396
Amortized Cost, Due after ten years	36,767	46,276
Amortized Cost, Total securities	294,259	403,005
Amortized Cost, Due in one year or less	1,007	'
Amortized Cost, Due after one year through five years	18,101	'
Amortized Cost, Due after five years through ten years	37,591	'
Amortized Cost, Due after ten years	38,205	'
Amortized Cost, Total securities	94,904	'
Estimated Market Value, Due in one year or less	12,368	119,753
Estimated Market Value, Due after one year through five years	65,038	108,349
Estimated Market Value, Due after five years through ten years	168,243	130,958
Estimated Market Value, Due after ten years	32,070	46,295
Estimated Market Value	277,719	405,355
Estimated Market Value, Due in one year or less	1,007	'
Estimated Market Value, Due after one year through five years	17,539	'
Estimated Market Value, Due after five years through ten years	37,137	'
Estimated Market Value, Due after ten years	35,283	'
Estimated Market Value, Total securities	$94,904	'

Investment_Securities_Summary_3

Investment Securities - Summary of Securities in Other Assets, at Cost (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Investments [Line Items]	'	'
Total equity securities	$6,552	$6,738
FHLB stock [Member]	'	'
Schedule of Investments [Line Items]	'	'
Total equity securities	1,099	2,938
First National Bankers Bankshares, Inc. (FNBB) stock [Member]	'	'
Schedule of Investments [Line Items]	'	'
Total equity securities	600	600
Other investments [Member]	'	'
Schedule of Investments [Line Items]	'	'
Total equity securities	$4,853	$3,200

Loans_Summary_of_Major_Classif

Loans - Summary of Major Classifications of Loans (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Thousands, unless otherwise specified
Commercial real estate loans:	'	'	'	'
Construction	$203,369	$159,999	'	'
Mortgage	1,118,048	983,164	'	'
Total commercial real estate loans	1,321,417	1,143,163	'	'
Consumer real estate loans:	'	'	'	'
Construction	8,986	7,738	'	'
Mortgage	115,307	102,699	'	'
Total consumer real estate loans	124,293	110,437	'	'
Commercial and industrial loans	868,469	622,105	'	'
Loans to individuals, excluding real estate	16,345	14,000	'	'
Nonaccrual loans	16,396	21,083	'	'
Other loans	10,857	11,429	'	'
Loans, gross	2,357,777	1,922,217	'	'
Less allowance for loan losses	-32,143	-26,977	-18,122	-12,508
Loans, net	$2,325,634	$1,895,240	'	'

Loans_Summary_of_Major_Classif1

Loans - Summary of Major Classifications of Loans (Parenthetical) (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Federal Home Loan Banks [Abstract]	'	'
Commercial real estate loans	$364.90	$345.40

Loans_Summary_of_Changes_in_Al

Loans - Summary of Changes in Allowance for Loan Losses (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance For Loan And Lease Losses [Roll Forward]	'	'	'	'	'	'	'	'	'	'	'
Balance, beginning of period	'	'	'	$26,977	'	'	'	$18,122	$26,977	$18,122	$12,508
Provision charged to operations	2,400	2,400	2,400	2,600	4,800	1,800	1,800	2,635	9,800	11,035	8,010
Charge-offs	'	'	'	'	'	'	'	'	-4,769	-2,561	-2,462
Recoveries	'	'	'	'	'	'	'	'	135	381	66
Balance, end of period	$32,143	'	'	'	$26,977	'	'	'	$32,143	$26,977	$18,122

Loans_Additional_Information_D

Loans - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Receivables [Abstract]	'	'
Net of amortization	$10,600,000	$9,000,000
Overdraft	800,000	800,000
Financing Receivable, Recorded Investment, 30 to 90 Days Past Due	7,774,000	2,139,000
Financing Receivable, Equal to Greater than 90 Days Past Due	11,371,000	9,567,000
Average recorded investment in nonaccrual loan	17,900,000	8,200,000
Amount of interest income	1,000,000	400,000
Substandard Loans [Member]	'	'
Receivables [Abstract]	'	'
Loans acquired with deteriorated credit quality	7,400,000	8,900,000
Special Mention Loans [Member]	'	'
Receivables [Abstract]	'	'
Loans acquired with deteriorated credit quality	1,600,000	1,600,000
Blanket Lien [Member]	'	'
Receivables [Abstract]	'	'
Loans with carrying value pledged to secure other borrowings	655,100,000	481,800,000
Custody Pledge [Member]	'	'
Receivables [Abstract]	'	'
Loans with carrying value pledged to secure other borrowings	29,400,000	49,900,000
Other Consumer Loan [Member]	'	'
Receivables [Abstract]	'	'
Financing Receivable, Recorded Investment, 30 to 90 Days Past Due	400,000	'
Financing Receivable, Equal to Greater than 90 Days Past Due	200,000	'
Secured Tuition Loans [Member]	'	'
Receivables [Abstract]	'	'
Financing Receivable, Equal to Greater than 90 Days Past Due	$200,000	'

Loans_Summary_of_Allowance_for

Loans - Summary of Allowance for Loan Losses and Recorded Investment in Loans (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Allowance For Loan Losses [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Balance, beginning of period	'	'	'	$26,977	'	'	'	$18,122	$26,977	$18,122	$12,508
Charge-offs	'	'	'	'	'	'	'	'	-4,769	-2,561	-2,462
Recoveries	'	'	'	'	'	'	'	'	135	381	66
Provision	2,400	2,400	2,400	2,600	4,800	1,800	1,800	2,635	9,800	11,035	8,010
Balance, end of period	32,143	'	'	'	26,977	'	'	'	32,143	26,977	18,122
Individually evaluated for impairment	3,955	'	'	'	6,942	'	'	'	3,955	6,942	'
Collectively evaluated for impairment	28,188	'	'	'	20,035	'	'	'	28,188	20,035	'
Ending balance-total	2,357,777	'	'	'	1,922,217	'	'	'	2,357,777	1,922,217	'
Loans receivable [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Allowance For Loan Losses [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Ending balance-total	2,357,777	'	'	'	1,922,217	'	'	'	2,357,777	1,922,217	'
Individually evaluated for impairment	17,115	'	'	'	21,313	'	'	'	17,115	21,313	'
Collectively evaluated for impairment	2,340,662	'	'	'	1,900,904	'	'	'	2,340,662	1,900,904	'
Construction [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Allowance For Loan Losses [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Balance, beginning of period	'	'	'	2,004	'	'	'	722	2,004	722	'
Charge-offs	'	'	'	'	'	'	'	'	-46	'	'
Recoveries	'	'	'	'	'	'	'	'	'	16	'
Provision	'	'	'	'	'	'	'	'	832	1,266	'
Balance, end of period	2,790	'	'	'	2,004	'	'	'	2,790	2,004	'
Individually evaluated for impairment	42	'	'	'	176	'	'	'	42	176	'
Collectively evaluated for impairment	2,748	'	'	'	1,828	'	'	'	2,748	1,828	'
Ending balance-total	212,430	'	'	'	168,544	'	'	'	212,430	168,544	'
Construction [Member] | Loans receivable [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Allowance For Loan Losses [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Ending balance-total	212,430	'	'	'	168,544	'	'	'	212,430	168,544	'
Individually evaluated for impairment	309	'	'	'	799	'	'	'	309	799	'
Collectively evaluated for impairment	212,121	'	'	'	167,745	'	'	'	212,121	167,745	'
Commercial real estate [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Allowance For Loan Losses [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Balance, beginning of period	'	'	'	10,716	'	'	'	9,871	10,716	9,871	'
Charge-offs	'	'	'	'	'	'	'	'	-292	-1,262	'
Recoveries	'	'	'	'	'	'	'	'	19	132	'
Provision	'	'	'	'	'	'	'	'	3,337	1,975	'
Balance, end of period	13,780	'	'	'	10,716	'	'	'	13,780	10,716	'
Individually evaluated for impairment	1,639	'	'	'	951	'	'	'	1,639	951	'
Collectively evaluated for impairment	12,141	'	'	'	9,765	'	'	'	12,141	9,765	'
Ending balance-total	1,128,181	'	'	'	988,994	'	'	'	1,128,181	988,994	'
Commercial real estate [Member] | Loans receivable [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Allowance For Loan Losses [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Ending balance-total	1,128,181	'	'	'	988,994	'	'	'	1,128,181	988,994	'
Individually evaluated for impairment	9,811	'	'	'	5,203	'	'	'	9,811	5,203	'
Collectively evaluated for impairment	1,118,370	'	'	'	983,791	'	'	'	1,118,370	983,791	'
Consumer real estate [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Allowance For Loan Losses [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Balance, beginning of period	'	'	'	2,450	'	'	'	1,519	2,450	1,519	'
Charge-offs	'	'	'	'	'	'	'	'	'	-59	'
Recoveries	'	'	'	'	'	'	'	'	30	22	'
Provision	'	'	'	'	'	'	'	'	176	968	'
Balance, end of period	2,656	'	'	'	2,450	'	'	'	2,656	2,450	'
Individually evaluated for impairment	183	'	'	'	362	'	'	'	183	362	'
Collectively evaluated for impairment	2,473	'	'	'	2,088	'	'	'	2,473	2,088	'
Ending balance-total	117,653	'	'	'	103,516	'	'	'	117,653	103,516	'
Consumer real estate [Member] | Loans receivable [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Allowance For Loan Losses [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Ending balance-total	117,653	'	'	'	103,516	'	'	'	117,653	103,516	'
Individually evaluated for impairment	2,990	'	'	'	1,178	'	'	'	2,990	1,178	'
Collectively evaluated for impairment	114,663	'	'	'	102,338	'	'	'	114,663	102,338	'
Commercial and industrial [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Allowance For Loan Losses [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Balance, beginning of period	'	'	'	11,675	'	'	'	5,928	11,675	5,928	'
Charge-offs	'	'	'	'	'	'	'	'	-4,229	-1,068	'
Recoveries	'	'	'	'	'	'	'	'	68	153	'
Provision	'	'	'	'	'	'	'	'	5,163	6,662	'
Balance, end of period	12,677	'	'	'	11,675	'	'	'	12,677	11,675	'
Individually evaluated for impairment	2,091	'	'	'	5,453	'	'	'	2,091	5,453	'
Collectively evaluated for impairment	10,586	'	'	'	6,222	'	'	'	10,586	6,222	'
Ending balance-total	883,111	'	'	'	647,090	'	'	'	883,111	647,090	'
Commercial and industrial [Member] | Loans receivable [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Allowance For Loan Losses [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Ending balance-total	883,111	'	'	'	647,090	'	'	'	883,111	647,090	'
Individually evaluated for impairment	4,005	'	'	'	14,133	'	'	'	4,005	14,133	'
Collectively evaluated for impairment	879,106	'	'	'	632,957	'	'	'	879,106	632,957	'
Other consumer [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Allowance For Loan Losses [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Balance, beginning of period	'	'	'	132	'	'	'	82	132	82	'
Charge-offs	'	'	'	'	'	'	'	'	-202	-172	'
Recoveries	'	'	'	'	'	'	'	'	18	58	'
Provision	'	'	'	'	'	'	'	'	292	164	'
Balance, end of period	240	'	'	'	132	'	'	'	240	132	'
Individually evaluated for impairment	'	'	'	'	'	'	'	'	'	'	'
Collectively evaluated for impairment	240	'	'	'	132	'	'	'	240	132	'
Ending balance-total	16,402	'	'	'	14,073	'	'	'	16,402	14,073	'
Other consumer [Member] | Loans receivable [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Allowance For Loan Losses [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Ending balance-total	16,402	'	'	'	14,073	'	'	'	16,402	14,073	'
Individually evaluated for impairment	'	'	'	'	'	'	'	'	'	'	'
Collectively evaluated for impairment	$16,402	'	'	'	$14,073	'	'	'	$16,402	$14,073	'

Loans_Summary_of_Credit_Qualit

Loans - Summary of Credit Quality Indicators on Company's Loan Portfolio (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	$2,357,777	$1,922,217
Construction [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	212,430	168,544
Commercial real estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	1,128,181	988,994
Consumer real estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	117,653	103,516
Commercial and industrial [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	883,111	647,090
Other consumer [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	16,402	14,073
Pass and Pass/Watch [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	2,274,125	1,845,486
Pass and Pass/Watch [Member] | Construction [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	197,951	146,748
Pass and Pass/Watch [Member] | Commercial real estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	1,073,339	962,694
Pass and Pass/Watch [Member] | Consumer real estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	113,037	101,334
Pass and Pass/Watch [Member] | Commercial and industrial [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	873,547	620,851
Pass and Pass/Watch [Member] | Other consumer [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	16,251	13,859
Special Mention Loans [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	1,935	5,738
Special Mention Loans [Member] | Construction [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	4	3,258
Special Mention Loans [Member] | Commercial real estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	1,720	1,698
Special Mention Loans [Member] | Consumer real estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	185	751
Special Mention Loans [Member] | Commercial and industrial [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	17	18
Special Mention Loans [Member] | Other consumer [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	9	13
Substandard Loans [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	81,717	59,756
Substandard Loans [Member] | Construction [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	14,475	18,538
Substandard Loans [Member] | Commercial real estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	53,122	24,602
Substandard Loans [Member] | Consumer real estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	4,431	1,431
Substandard Loans [Member] | Commercial and industrial [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	9,547	14,984
Substandard Loans [Member] | Other consumer [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	142	201
Doubtful [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	0	11,237
Doubtful [Member] | Construction [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	0	0
Doubtful [Member] | Commercial real estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	0	0
Doubtful [Member] | Consumer real estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	0	0
Doubtful [Member] | Commercial and industrial [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	0	11,237
Doubtful [Member] | Other consumer [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	$0	$0

Loans_Age_Analysis_of_Past_Due

Loans - Age Analysis of Past Due Loans Including Loans Acquired with Deteriorated Credit Quality (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Financing Receivable, Recorded Investment [Line Items]	'	'
Greater Than 30 and Fewer Than 90 Days Past Due	$7,774	$2,139
90 Days and Greater Past Due	11,371	9,567
Total Past Due	19,145	11,706
Current Loans	2,338,632	1,910,511
Loans, gross	2,357,777	1,922,217
Total real estate loans [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Greater Than 30 and Fewer Than 90 Days Past Due	4,210	1,443
90 Days and Greater Past Due	9,883	7,316
Total Past Due	14,093	8,759
Current Loans	1,444,171	1,252,295
Loans, gross	1,458,264	1,261,054
Other Loans [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Greater Than 30 and Fewer Than 90 Days Past Due	3,564	696
90 Days and Greater Past Due	1,488	2,251
Total Past Due	5,052	2,947
Current Loans	894,461	658,216
Loans, gross	899,513	661,163
Construction [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Greater Than 30 and Fewer Than 90 Days Past Due	15	'
90 Days and Greater Past Due	75	751
Total Past Due	90	751
Current Loans	212,340	167,793
Loans, gross	212,430	168,544
Commercial real estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Greater Than 30 and Fewer Than 90 Days Past Due	2,935	960
90 Days and Greater Past Due	7,642	5,914
Total Past Due	10,577	6,874
Current Loans	1,117,604	982,120
Loans, gross	1,128,181	988,994
Consumer real estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Greater Than 30 and Fewer Than 90 Days Past Due	1,260	483
90 Days and Greater Past Due	2,166	651
Total Past Due	3,426	1,134
Current Loans	114,227	102,382
Loans, gross	117,653	103,516
Commercial and industrial [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Greater Than 30 and Fewer Than 90 Days Past Due	3,076	671
90 Days and Greater Past Due	1,281	2,197
Total Past Due	4,357	2,868
Current Loans	878,754	644,222
Loans, gross	883,111	647,090
Other consumer [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Greater Than 30 and Fewer Than 90 Days Past Due	488	25
90 Days and Greater Past Due	207	54
Total Past Due	695	79
Current Loans	15,707	13,994
Loans, gross	$16,402	$14,073

Loans_Summary_of_Information_P

Loans - Summary of Information Pertaining to Impaired Loans (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Impaired [Line Items]	'	'
With no related allowance recorded, Recorded Investment	$7,333	$3,300
With no related allowance recorded, Contractual Balance	7,584	3,440
With no related allowance recorded, Related Allowance	'	'
With no related allowance recorded, Average Recorded Investment	5,318	5,293
With no related allowance recorded, Interest Income Recognized	150	89
With an allowance recorded, Recorded Investment	9,782	18,013
With an allowance recorded, Contractual Balance	11,724	18,042
With an allowance recorded, Related Allowance	3,955	6,942
With an allowance recorded, Average Recorded Investment	13,899	9,831
With an allowance recorded, Interest Income Recognized	113	459
Total impaired loans, Recorded Investment	17,115	21,313
Total impaired loans, Contractual Balance	19,308	21,482
Total impaired loans, Related Allowance	3,955	6,942
Total impaired loans, Average Recorded Investment	19,217	15,124
Total impaired loans, Interest Income Recognized	263	548
Construction [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
With no related allowance recorded, Recorded Investment	'	48
With no related allowance recorded, Contractual Balance	'	48
With no related allowance recorded, Related Allowance	'	'
With no related allowance recorded, Average Recorded Investment	24	1,146
With no related allowance recorded, Interest Income Recognized	'	3
With an allowance recorded, Recorded Investment	309	751
With an allowance recorded, Contractual Balance	309	751
With an allowance recorded, Related Allowance	42	176
With an allowance recorded, Average Recorded Investment	530	376
With an allowance recorded, Interest Income Recognized	23	14
Total impaired loans, Recorded Investment	309	799
Total impaired loans, Contractual Balance	309	799
Total impaired loans, Related Allowance	42	176
Total impaired loans, Average Recorded Investment	554	1,522
Total impaired loans, Interest Income Recognized	23	17
Commercial real estate [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
With no related allowance recorded, Recorded Investment	4,261	1,864
With no related allowance recorded, Contractual Balance	4,469	1,984
With no related allowance recorded, Related Allowance	'	'
With no related allowance recorded, Average Recorded Investment	3,063	2,478
With no related allowance recorded, Interest Income Recognized	110	30
With an allowance recorded, Recorded Investment	5,550	3,339
With an allowance recorded, Contractual Balance	7,428	3,367
With an allowance recorded, Related Allowance	1,639	548
With an allowance recorded, Average Recorded Investment	4,445	1,855
With an allowance recorded, Interest Income Recognized	59	47
Total impaired loans, Recorded Investment	9,811	5,203
Total impaired loans, Contractual Balance	11,897	5,351
Total impaired loans, Related Allowance	1,639	548
Total impaired loans, Average Recorded Investment	7,508	4,333
Total impaired loans, Interest Income Recognized	169	77
Consumer real estate [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
With no related allowance recorded, Recorded Investment	1,973	534
With no related allowance recorded, Contractual Balance	1,999	534
With no related allowance recorded, Related Allowance	'	'
With no related allowance recorded, Average Recorded Investment	1,254	639
With no related allowance recorded, Interest Income Recognized	'	2
With an allowance recorded, Recorded Investment	1,017	644
With an allowance recorded, Contractual Balance	1,046	644
With an allowance recorded, Related Allowance	183	765
With an allowance recorded, Average Recorded Investment	831	819
With an allowance recorded, Interest Income Recognized	21	9
Total impaired loans, Recorded Investment	2,990	1,178
Total impaired loans, Contractual Balance	3,045	1,178
Total impaired loans, Related Allowance	183	765
Total impaired loans, Average Recorded Investment	2,085	1,458
Total impaired loans, Interest Income Recognized	21	11
Commercial and industrial [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
With no related allowance recorded, Recorded Investment	1,099	854
With no related allowance recorded, Contractual Balance	1,116	874
With no related allowance recorded, Related Allowance	'	'
With no related allowance recorded, Average Recorded Investment	977	1,030
With no related allowance recorded, Interest Income Recognized	40	54
With an allowance recorded, Recorded Investment	2,906	13,279
With an allowance recorded, Contractual Balance	2,941	13,280
With an allowance recorded, Related Allowance	2,091	5,453
With an allowance recorded, Average Recorded Investment	8,093	6,781
With an allowance recorded, Interest Income Recognized	10	389
Total impaired loans, Recorded Investment	4,005	14,133
Total impaired loans, Contractual Balance	4,057	14,154
Total impaired loans, Related Allowance	2,091	5,453
Total impaired loans, Average Recorded Investment	9,070	7,811
Total impaired loans, Interest Income Recognized	$50	$443

Loans_Summary_of_Nonaccrual_Lo

Loans - Summary of Nonaccrual Loans (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Loans Receivable [Line Items]	'	'
Nonaccrual loans	$16,396	$21,083
Nonaccrual Loans [Member] | Construction [Member]	'	'
Loans Receivable [Line Items]	'	'
Nonaccrual loans	75	806
Nonaccrual Loans [Member] | Commercial real estate [Member]	'	'
Loans Receivable [Line Items]	'	'
Nonaccrual loans	10,133	5,831
Nonaccrual Loans [Member] | Consumer real estate [Member]	'	'
Loans Receivable [Line Items]	'	'
Nonaccrual loans	2,347	818
Nonaccrual Loans [Member] | Commercial and industrial [Member]	'	'
Loans Receivable [Line Items]	'	'
Nonaccrual loans	3,784	13,556
Nonaccrual Loans [Member] | Other consumer [Member]	'	'
Loans Receivable [Line Items]	'	'
Nonaccrual loans	$57	$72

Loans_Summary_of_Changes_in_Ac

Loans - Summary of Changes in Accretable Yields of Acquired Loans (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Receivables [Abstract]	'	'
Balance, beginning of period	$628	$1,374
Acquisition	'	'
Net transfers from nonaccretable difference to accretable yield	45	361
Accretion	-503	-1,107
Balance, end of period	$170	$628

Loans_Summary_of_Companys_TDRs

Loans - Summary of Company's TDRs (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Financing Receivable, Modifications [Line Items]	'	'
Current	$1,628	$1,354
Greater than 30 Days Past Due	'	'
Nonaccrual TDRs	238	982
Total Loans	1,866	2,336
Total real estate loans [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Current	1,291	970
Greater than 30 Days Past Due	'	'
Nonaccrual TDRs	238	982
Total Loans	1,529	1,952
Total real estate loans [Member] | Construction [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Current	309	47
Greater than 30 Days Past Due	'	'
Nonaccrual TDRs	'	'
Total Loans	309	47
Total real estate loans [Member] | Commercial real estate [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Current	357	268
Greater than 30 Days Past Due	'	'
Nonaccrual TDRs	102	982
Total Loans	459	1,250
Total real estate loans [Member] | Consumer real estate [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Current	625	655
Greater than 30 Days Past Due	'	'
Nonaccrual TDRs	136	'
Total Loans	761	655
Other Loans [Member] | Commercial and industrial [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Current	337	384
Greater than 30 Days Past Due	'	'
Nonaccrual TDRs	'	'
Total Loans	$337	$384

Loans_Summary_of_Information_o

Loans - Summary of Information on TDRs Modification (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Receivables [Abstract]	'	'
Maturity and interest rate adjustment	$925	$609
Movement to or extension of interest rate-only payments	597	1,333
Other concession(s)	344	394
Total	$1,866	$2,336

Loans_Summary_of_Information_P1

Loans - Summary of Information Pertaining to Modified Terms of Loans (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
	Contract	Contract
Financing Receivable, Modifications [Line Items]	'	'
Number of Contracts	9	7
Pre- Modification Outstanding Recorded Investment	$1,866	$2,336
Post- Modification Outstanding Recorded Investment	1,866	2,336
Troubled debt restructuring [Member] | Construction [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Contracts	2	1
Pre- Modification Outstanding Recorded Investment	309	47
Post- Modification Outstanding Recorded Investment	309	47
Troubled debt restructuring [Member] | Commercial real estate [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Contracts	3	2
Pre- Modification Outstanding Recorded Investment	459	1,250
Post- Modification Outstanding Recorded Investment	459	1,250
Troubled debt restructuring [Member] | Consumer real estate [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Contracts	3	3
Pre- Modification Outstanding Recorded Investment	761	655
Post- Modification Outstanding Recorded Investment	761	655
Troubled debt restructuring [Member] | Commercial and industrial [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Contracts	1	1
Pre- Modification Outstanding Recorded Investment	337	384
Post- Modification Outstanding Recorded Investment	$337	$384

Transfers_and_Servicing_of_Fin1

Transfers and Servicing of Financial Assets - Additional Information (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Servicing Asset At Amortized Value Additional Disclosures [Abstract]	'	'
Unpaid principal balances of loans	$28	$40.60

Premises_and_Equipment_Schedul

Premises and Equipment - Schedule of Premises and Equipment (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Premises and equipment, Gross	$61,479	$54,667
Less accumulated depreciation and amortization	10,305	7,600
Total premises and equipment, net	51,174	47,067
Buildings and leasehold improvements [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Premises and equipment, Gross	35,765	30,716
Land [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Premises and equipment, Gross	10,399	8,940
Furniture, fixtures, and equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Premises and equipment, Gross	13,773	11,536
Construction in progress [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Premises and equipment, Gross	$1,542	$3,475

Premises_and_Equipment_Additio

Premises and Equipment - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property Plant And Equipment [Abstract]	'	'	'
Depreciation Expense	$2.70	$2.70	$1.70

Other_Real_Estate_Owned_Additi

Other Real Estate Owned - Additional Information (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Real Estate [Abstract]	'	'
Companies other real estate own or acquired by foreclosure	$3.70	$8.60

Goodwill_and_Other_Acquired_In2

Goodwill and Other Acquired Intangible Assets - Changes to Carrying Amount of Goodwill (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Goodwill And Intangible Assets Disclosure [Abstract]	'	'
Beginning Balance	$4,808	$4,808
Goodwill acquired during the year	'	'
Ending Balance	$4,808	$4,808

Goodwill_and_Other_Acquired_In3

Goodwill and Other Acquired Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Goodwill And Intangible Assets Disclosure [Abstract]	'	'	'
Core deposit intangibles	$3.50	$3.80	'
Accumulated amortization	0.9	0.6	'
Intangible assets, estimated useful life (in years)	'12 years	'	'
Amortization expense, Total	$0.20	$0.20	$0.40

Goodwill_and_Other_Acquired_In4

Goodwill and Other Acquired Intangible Assets - Schedule of Finite Lived Intangible Assets Future Amortization Expense (Detail) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Goodwill And Intangible Assets Disclosure [Abstract]	'
2014-2018	$376
2019 and thereafter	$2,272

Investments_in_Real_Estate_Pro1

Investments in Real Estate Properties - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Investments Schedule [Abstract]	'	'	'
Real estate properties at cost	$10.10	$6.90	'
Capitalized cost	$5	$0.90	$1

Investments_in_Tax_Credit_Enti1

Investments in Tax Credit Entities - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net Investment Income [Line Items]	'	'	'
Generated Tax credits	$8,639,000	$4,808,000	$2,868,000
Tax credit as Percentage of project cost	39.00%	'	'
Credit allowance period	'7 years	'	'
Qualified Equity Investments	118,000,000	'	'
CDE gross amount	118,000,000	'	'
Total assets	3,286,617,000	2,670,867,000	'
Cash	28,140,000	26,471,000	'
Loans	2,325,634,000	1,895,240,000	'
Other assets	23,781,000	20,915,000	'
Liabilities	2,904,758,000	2,422,765,000	'
Due Between One Year And Three Years [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Investor receives a credit equal to the total amount invested in the project	5.00%	'	'
Due Between Year Four And Year Seven [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Investor receives a credit equal to the total amount invested in the project	6.00%	'	'
Maximum [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Received allocation amount	46,000,000	'	'
Federal NMTC [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Received allocation amount	50,000,000	40,000,000	28,000,000
Generated Tax credits	19,500,000	15,600,000	10,900,000
Investments in QEI projects	'The CDE is required to invest the proceeds of each QEI in projects located in or benefitting low-income communities, which are generally defined as those census tracts with poverty rates greater than 20% and/or median family incomes that are less than or equal to 80% of the area median family income.	'	'
CDE investments in QEI projects located in low-income communities with poverty rates	20.00%	'	'
CDE investments in QEI projects located in low-income communities with median family income	80.00%	'	'
Amount received as cumulative awards	118,000,000	'	'
Credit allowance period	'6 years	'	'
Investments generated recognized	46,000,000	'	'
Investments generated recognized	10,400,000	'	'
Accrued Tax Credit	35,600,000	'	'
First National Banking Company [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
CDE gross amount	22,500,000	'	'
Lender [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
CDE gross amount	62,900,000	'	'
State [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
CDE gross amount	32,600,000	'	'
Certified Development Entities [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Generated Tax credits	61,200,000	'	'
Total assets	68,700,000	'	'
Cash	27,900,000	'	'
Loans	40,700,000	'	'
Other assets	100,000	'	'
Liabilities	100,000	'	'
Capital	68,600,000	'	'
Investments	61,200,000	'	'
Loans related to real estate	81,800,000	64,100,000	'
Certified Development Entities [Member] | Investment In Limited Partnership [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Generated Tax credits	60,600,000	'	'
Accrued Tax Credit	33,400,000	'	'
Tax credits recognized	27,200,000	'	'
Low-Income Housing tax credits [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Accrued Tax Credit	47,400,000	'	'
Investments	40,000,000	25,300,000	'
Tax credits recognized	9,500,000	'	'
Investment in partnership expected to generate Low-Income Housing tax credit	57,000,000	'	'
Interest in property	99.90%	'	'
Property investment term	'15 years	'	'
Loans related to real estate projects	42,000,000	42,000,000	'
Federal Historic tax credits [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Generated Tax credits	25,700,000	'	'
Investments	16,500,000	7,100,000	'
Tax credits recognized	17,800,000	'	'
Interest in property	99.90%	'	'
Property investment term	'10 years	'	'
Tax credits expected to be recognized during the year	$7,500,000	'	'
Community Development Fund [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Qualified Equity Investment low Income community investment percentage	85.00%	'	'

Deposit_Summary_of_Scheduled_I

Deposit - Summary of Scheduled Interest Bearing Deposits (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Investments Schedule [Abstract]	'	'
Savings	$53,779	$45,295
Money market accounts	655,173	410,928
Negotiable order of withdrawal (NOW) accounts	511,620	437,542
Certificates of deposit over $100,000	820,374	698,007
Certificates of deposit under $100,000	398,781	437,218
Total	$2,439,727	$2,028,990

Deposit_Summary_of_Scheduled_M

Deposit - Summary of Scheduled Maturities of Time Deposits (Detail) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Investments Schedule [Abstract]	'
2014	$550,700
2015	282,427
2016	194,253
2017	74,821
2018	115,839
Thereafter	1,115
Total	$1,219,155

ShortTerm_Borrowings_Summary_o

Short-Term Borrowings - Summary of Short-Term Borrowings (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Line of Credit Facility [Line Items]	'	'
Total short-term borrowings	$8,425	$21,800
FNBB [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Total short-term borrowings	$8,425	$21,800

ShortTerm_Borrowings_Additiona

Short-Term Borrowings - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Short-term Debt [Line Items]	'	'
Federal funds interest rate	0.95%	0.95%
Federal Funds Purchased [Member]	'	'
Short-term Debt [Line Items]	'	'
Federal funds maturity date	'	'1 day
Blanket Pledge [Member] | FHLB [Member]	'	'
Short-term Debt [Line Items]	'	'
FHLB line of credit	655.1	481.8
Custody Pledge [Member] | FHLB [Member]	'	'
Short-term Debt [Line Items]	'	'
FHLB line of credit	29.4	49.9

ShortTerm_Borrowings_Summary_o1

Short-Term Borrowings - Summary of Unused Lines of Credit (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Line of Credit Facility [Line Items]	'	'
Total unused lines of credit	$527,181	$413,032
FNBB [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Total unused lines of credit	30,000	30,000
JPMorgan Chase [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Total unused lines of credit	30,000	30,000
FHLB [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Total unused lines of credit	432,181	338,032
PNC Bank [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Total unused lines of credit	15,000	15,000
Comerica [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Total unused lines of credit	$20,000	'

LongTerm_Borrowings_Summary_of

Long-Term Borrowings - Summary of Long -Term Borrowings (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Line of Credit Facility [Line Items]	'	'
Long-term borrowings	$55,110	$75,220
FNBB [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Long-term borrowings	110	220
Credit Suisse Securities (USA) LLC [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Long-term borrowings	55,000	55,000
Comerica [Member]	'	'
Line of Credit Facility [Line Items]	'	'
Long-term borrowings	'	$20,000

LongTerm_Borrowings_Additional

Long-Term Borrowings - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2009
Line of Credit Facility [Line Items]	'	'	'
Long term borrowings	$55,110,000	$75,220,000	'
Credit Suisse [Member]	'	'	'
Line of Credit Facility [Line Items]	'	'	'
Market value of mortgaged securities	67,000,000	73,800,000	'
Credit Suisse [Member] | $15 million borrowing [Member]	'	'	'
Line of Credit Facility [Line Items]	'	'	'
Debt instrument maturity date	19-Oct-14	'	'
Debt instrument interest rate	2.03%	2.03%	'
Long term borrowings	15,000,000	'	'
Debt instrument interest rate description	'Interest at a floating rate equal to 2.03% minus the greater of 3-month USD LIBOR less 1.50% or 0%, and was 2.03% at December 31, 2013 and 2012.	'	'
Credit Suisse [Member] | $40 million borrowing [Member]	'	'	'
Line of Credit Facility [Line Items]	'	'	'
Debt instrument maturity date	21-Jun-15	'	'
Debt instrument interest rate	2.83%	'	'
Long term borrowings	40,000,000	'	'
Debt instrument interest rate description	'Interest at a floating rate equal to 2.83% minus the greater of three-month USD LIBOR less 2.00% or 0%, and was 2.83% at December 31, 2013.	'	'
FNBB [Member]	'	'	'
Line of Credit Facility [Line Items]	'	'	'
Purchase of shares	'	'	50,000
Long term borrowings	'	'	550,000
Debt instrument maturity date	22-Dec-14	'	'
Shares pledged as collateral	10,000	20,000	'
Long term borrowings	$110,000	$220,000	'
FNBB [Member] | Wall Street Journal Prime Rate [Member]	'	'	'
Line of Credit Facility [Line Items]	'	'	'
Debt instrument interest rate	3.25%	3.25%	'

LongTerm_Borrowings_Summary_of1

Long-Term Borrowings - Summary of Principal Payments (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]	'	'
2014	$15,110	'
2015	40,000	'
Total long-term borrowings	$55,110	$75,220

Repurchase_Agreements_Addition

Repurchase Agreements - Additional Information (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Equity [Abstract]	'	'
Carrying value of securities pledged	$92.70	$32.70

Derivative_Interest_Rate_Swap_1

Derivative - Interest Rate Swap Agreement - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Interest Rate Derivatives Outstanding [Line Items]	'	'
Notional amount of derivative contract	$150,000,000	'
Interest rate swap fixed percentage	4.17%	'
Derivative instruments, gain (Loss) Reclassified from Accumulated OCI	0	'
Derivative, Ineffectiveness Gain (Loss)	0	'
Financial Instruments Owned and Pledged as Collateral	9,600,000	'
Financial Instruments, Owned and Pledged as Collateral, at Fair Value	9,600,000	'
Amount of derivative will mature within next 12 months	0	'
Gain loss after income tax recognized in other comprehensive income	5,200,000	4,500,000
The fair value of the derivative liability	'	6,900,000
Fair value of derivative assets	1,200,000	'
Investment securities principal amount	12,700,000	'
Fair value of investment securities	12,100,000	'
Interest Rate Swap [Member]	'	'
Interest Rate Derivatives Outstanding [Line Items]	'	'
Notional amount of derivative contract	250,000,000	115,000,000
Interest rate swap fixed percentage	'	2.88%
Number of interest rate swaps	4	'
Other comprehensive income (Loss), Derivatives net of tax	2,800,000	'
Derivative Liability, Fair Value	2,000,000	'
Prime Swaps [Member]	'	'
Interest Rate Derivatives Outstanding [Line Items]	'	'
Derivative Liability, Fair Value	2,300,000	'
Prime Rate [Member] | Interest Rate Swap [Member]	'	'
Interest Rate Derivatives Outstanding [Line Items]	'	'
Notional amount of derivative contract	30,000,000	'
Interest rate swap fixed percentage	4.70%	'
Debt instrument description of variable rate basis	'Prime	'
Debt instrument basis spread on variable rate	1.00%	'
Prime plus 1% [Member] | Interest Rate Swap [Member]	'	'
Interest Rate Derivatives Outstanding [Line Items]	'	'
Notional amount of derivative contract	40,000,000	'
Interest rate swap fixed percentage	5.70%	'
Debt instrument description of variable rate basis	'Prime plus 1%	'
Debt instrument basis spread on variable rate	1.00%	'
Prime plus 1% floored at 5% [Member] | Interest Rate Swap [Member]	'	'
Interest Rate Derivatives Outstanding [Line Items]	'	'
Notional amount of derivative contract	100,000,000	'
Interest rate swap fixed percentage	6.01%	'
Debt instrument description of variable rate basis	'Prime plus 1% floored at 5%	'
Debt instrument basis spread on variable rate	1.00%	'
Debt instrument interest floored rate	5.00%	'
Prime plus 1% floored at 5.5% [Member] | Interest Rate Swap [Member]	'	'
Interest Rate Derivatives Outstanding [Line Items]	'	'
Notional amount of derivative contract	$80,000,000	'
Interest rate swap fixed percentage	6.26%	'
Debt instrument description of variable rate basis	'Prime plus 1% floored at 5.5%	'
Debt instrument basis spread on variable rate	1.00%	'
Debt instrument interest floored rate	5.50%	'

Income_Taxes_Summary_of_Income

Income Taxes - Summary of Income Tax Benefit on Income from Operations (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Current tax expense	'	'	'	'	'	'	'	'	$186	'	'
Deferred tax benefit	'	'	'	'	'	'	'	'	-19,937	-7,565	-5,407
Income tax benefit	($5,867)	($5,673)	($4,198)	($4,013)	$443	($3,130)	($2,952)	($1,926)	($19,751)	($7,565)	($5,407)

Income_Taxes_Schedule_of_Incom

Income Taxes - Schedule of Income Taxes Reconciliation with Federal Statutory Rates (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Federal tax expense at statutory rates	'	'	'	'	'	'	'	'	$7,406	$7,481	$5,019
Tax credits	'	'	'	'	'	'	'	'	-28,421	-17,100	-13,142
Tax credit-basis reduction	'	'	'	'	'	'	'	'	2,019	2,767	3,112
Tax-exempt income	'	'	'	'	'	'	'	'	-832	-655	-509
Change in deferred rate	'	'	'	'	'	'	'	'	'	'	293
Disallowed interest expense	'	'	'	'	'	'	'	'	117	99	101
Other	'	'	'	'	'	'	'	'	-40	-157	-281
Income tax benefit	($5,867)	($5,673)	($4,198)	($4,013)	$443	($3,130)	($2,952)	($1,926)	($19,751)	($7,565)	($5,407)

Income_Taxes_Summary_of_Signif

Income Taxes - Summary of Significant Components of Deferred Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Deferred tax assets:	'	'
Loan loss reserve	$11,250	$9,397
Tax credit carryforwards	65,216	37,353
NOL carryforward	7,317	4,030
Stock-based compensation	684	436
Deferred compensation	91	91
Securities available for sale	8,880	1,563
Other real estate	250	269
Basis difference in assumed liabilities	338	1,701
Other	373	355
Total deferred tax assets	94,399	55,195
Deferred tax liabilities:	'	'
Fixed assets	6,546	5,867
Deferred loan costs	5,157	4,414
Amortizable costs	1,477	1,697
State tax credits	1,155	669
Investments in tax credit entities	28,097	25,789
Other	776	170
Total deferred tax liabilities	43,208	38,606
Net deferred tax assets	$51,191	$16,589

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Tax Credit Carryforward [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net operating loss carryforwards, expiration date	'	'	'	'	'	'	'	'	31-Dec-35	'	'
Income tax provision	($5,867,000)	($5,673,000)	($4,198,000)	($4,013,000)	$443,000	($3,130,000)	($2,952,000)	($1,926,000)	($19,751,000)	($7,565,000)	($5,407,000)
Generated Tax credits	'	'	'	'	'	'	'	'	28,421,000	17,100,000	13,142,000
Federal NMTC [Member]	'	'	'	'	'	'	'	'	'	'	'
Tax Credit Carryforward [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Income tax provision	'	'	'	'	'	'	'	'	14,200,000	11,400,000	7,900,000
Low-Income Housing tax credits [Member]	'	'	'	'	'	'	'	'	'	'	'
Tax Credit Carryforward [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Investment in partnership expected to generate Low-Income Housing tax credit	'	'	'	'	'	'	'	'	3,700,000	2,500,000	2,800,000
Federal Historic tax credits [Member]	'	'	'	'	'	'	'	'	'	'	'
Tax Credit Carryforward [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Generated Tax credits	'	'	'	'	'	'	'	'	10,500,000	3,200,000	2,200,000
December 2026 Through December 2032 [Member]	'	'	'	'	'	'	'	'	'	'	'
Tax Credit Carryforward [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Tax credit carryforwards	65,200,000	'	'	'	'	'	'	'	65,200,000	'	'
December 2034 [Member]	'	'	'	'	'	'	'	'	'	'	'
Tax Credit Carryforward [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net operating loss carryforwards	$20,900,000	'	'	'	'	'	'	'	$20,900,000	'	'
Minimum [Member]	'	'	'	'	'	'	'	'	'	'	'
Tax Credit Carryforward [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Tax credit carryforwards, expiration date	'	'	'	'	'	'	'	'	31-Dec-29	'	'
Maximum [Member]	'	'	'	'	'	'	'	'	'	'	'
Tax Credit Carryforward [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Tax credit carryforwards, expiration date	'	'	'	'	'	'	'	'	31-Dec-33	'	'

Shareholders_Equity_Additional

Shareholders' Equity - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Auction Market Preferred Securities, Stock Series [Line Items]	'	'	'
Common stock par value	$1	1	$1
Dividend description	'The Company may only declare and pay dividends on common stock (or repurchase shares of common stock) if, after payment of such dividend, the dollar amount of Tier 1 capital would be at least 90% of Tier 1 capital as of August 4, 2011, excluding charge-offs and redemptions of the Series D preferred stock (Tier 1 dividend threshold)	'	'
Minimum rate required to declare dividend	90.00%	'	'
Expected dividend rate	1.00%	'	'
Percentage of redemption price	100.00%	'	'
Series C Preferred Stock [Member]	'	'	'
Auction Market Preferred Securities, Stock Series [Line Items]	'	'	'
Convertible preferred stock shares converted	551,858	763,378	'
Convertible perpetual preferred stock	'	'	$20.60
Preferred stock aggregate liquidation	20.6	'	'
Series D Preferred Stock [Member]	'	'	'
Auction Market Preferred Securities, Stock Series [Line Items]	'	'	'
Convertible perpetual preferred stock	'	'	37.9
Preferred stock aggregate liquidation	$37.90	'	'

Shareholders_Equity_Schedule_o

Shareholders' Equity - Schedule of Annualized Dividend Rate (Detail)	12 Months Ended
	Dec. 31, 2013
Preferred Units [Line Items]	'
Annualized dividend rate	90.00%
August 4, 2011 - September 30, 2011 [Member]	'
Preferred Units [Line Items]	'
Annualized dividend rate	1.54%
October 1, 2011 - December 31, 2011 [Member]	'
Preferred Units [Line Items]	'
Annualized dividend rate	1.00%
January 1, 2012 - March 31, 2012 [Member]	'
Preferred Units [Line Items]	'
Annualized dividend rate	1.00%
April 1, 2012 - June 30, 2012 [Member]	'
Preferred Units [Line Items]	'
Annualized dividend rate	1.00%
July 1, 2012 - December 31, 2013 [Member] | Minimum [Member]	'
Preferred Units [Line Items]	'
Annualized dividend rate	1.00%
July 1, 2012 - December 31, 2013 [Member] | Maximum [Member]	'
Preferred Units [Line Items]	'
Annualized dividend rate	5.00%
January 1, 2014 - February 3, 2016 [Member] | Minimum [Member]	'
Preferred Units [Line Items]	'
Annualized dividend rate	1.00%
January 1, 2014 - February 3, 2016 [Member] | Maximum [Member]	'
Preferred Units [Line Items]	'
Annualized dividend rate	7.00%
February 4, 2016 - Redemption [Member]	'
Preferred Units [Line Items]	'
Annualized dividend rate	9.00%

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income - Summary of Changes in Accumulated Other Comprehensive Income (Loss) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'
Beginning balance	($2,926)	$1,795	($1,062)
Net change in unrealized gain (loss)	-14,882	-2,898	4,814
Transfer of net unrealized loss from available for sale to held to maturity, net of cumulative tax effect	-5,919	'	'
Reclassification of net gains realized and included in earnings	-316	-4,324	-485
Amortization of unrealized net loss on securities	211	'	'
Income tax expense (benefit)	-7,317	-2,501	1,472
Ending balance	-16,515	-2,926	1,795
Cash Flow Hedge [Member]	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'
Beginning balance	-4,455	'	'
Net change in unrealized gain (loss)	3,694	-6,854	'
Transfer of net unrealized loss from available for sale to held to maturity, net of cumulative tax effect	'	'	'
Reclassification of net gains realized and included in earnings	'	'	'
Amortization of unrealized net loss on securities	'	'	'
Income tax expense (benefit)	1,293	-2,399	'
Ending balance	-2,054	-4,455	'
Transfers of Available for Sale Securities to Held to Maturity [Member]	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'
Beginning balance	'	'	'
Net change in unrealized gain (loss)	'	'	'
Transfer of net unrealized loss from available for sale to held to maturity, net of cumulative tax effect	-5,919	'	'
Reclassification of net gains realized and included in earnings	'	'	'
Amortization of unrealized net loss on securities	211	'	'
Income tax expense (benefit)	-1,998	'	'
Ending balance	-3,710	'	'
Available-for-sale securities [Member]	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'
Beginning balance	1,529	1,795	-1,062
Net change in unrealized gain (loss)	-18,576	3,956	4,814
Transfer of net unrealized loss from available for sale to held to maturity, net of cumulative tax effect	'	'	'
Reclassification of net gains realized and included in earnings	-316	-4,324	-485
Amortization of unrealized net loss on securities	'	'	'
Income tax expense (benefit)	-6,612	-102	1,472
Ending balance	($10,751)	$1,529	$1,795

Capital_Requirements_and_Other2

Capital Requirements and Other Regulatory Matters - Summary of Capital Amounts and Ratios (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
First NBC Bank Holding Company [Member]	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Tier one leverage capital, Actual Amount	$375,355	$243,791
Tier one risk based capital, Actual Amount	375,355	243,791
Total risk based capital, Actual Amount	407,648	270,810
Tier one leverage capital, Actual Ratio	11.76%	9.04%
Tier one risk based capital, Actual Ratio	13.26%	11.26%
Total risk based capital, Actual Ratio	14.40%	12.51%
Tier one leverage capital, Capital Adequacy Purposes	127,625	107,814
Tier one risk based capital, Capital Adequacy Purposes	113,254	86,592
Total risk based capital, Capital Adequacy Purposes	226,508	173,184
Tier one leverage capital, Capital Adequacy Purposes Ratio	4.00%	4.00%
Tier one risk based capital, Capital Adequacy Purposes Ratio	4.00%	4.00%
Total risk based capital, Capital Adequacy Purposes Ratio	8.00%	8.00%
Tier one leverage capital to be Well Capitalized under Prompt Corrective Action Provisions, Amount	'	'
Tier one risk based capital to be Well Capitalized under Prompt Corrective Action Provisions, Amount	'	'
Total risk based capital to be Well Capitalized under Prompt Corrective Action Provisions, Amount	'	'
Tier one leverage capital to be Well Capitalized under Prompt Corrective Action Provisions, Ratio	'	'
Tier one risk based capital to be Well Capitalized under Prompt Corrective Action Provisions, Ratio	'	'
Total risk based capital to be Well Capitalized under Prompt Corrective Action Provisions, Ratio	'	'
First NBC Bank [Member]	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Tier one leverage capital, Actual Amount	349,104	256,848
Tier one risk based capital, Actual Amount	349,104	256,848
Total risk based capital, Actual Amount	381,396	283,867
Tier one leverage capital, Actual Ratio	10.96%	9.91%
Tier one risk based capital, Actual Ratio	12.34%	11.88%
Total risk based capital, Actual Ratio	13.48%	13.13%
Tier one leverage capital, Capital Adequacy Purposes	127,435	103,704
Tier one risk based capital, Capital Adequacy Purposes	113,170	86,457
Total risk based capital, Capital Adequacy Purposes	226,340	172,914
Tier one leverage capital, Capital Adequacy Purposes Ratio	4.00%	4.00%
Tier one risk based capital, Capital Adequacy Purposes Ratio	4.00%	4.00%
Total risk based capital, Capital Adequacy Purposes Ratio	8.00%	8.00%
Tier one leverage capital to be Well Capitalized under Prompt Corrective Action Provisions, Amount	159,294	129,630
Tier one risk based capital to be Well Capitalized under Prompt Corrective Action Provisions, Amount	169,755	129,686
Total risk based capital to be Well Capitalized under Prompt Corrective Action Provisions, Amount	$282,924	$216,143
Tier one leverage capital to be Well Capitalized under Prompt Corrective Action Provisions, Ratio	5.00%	5.00%
Tier one risk based capital to be Well Capitalized under Prompt Corrective Action Provisions, Ratio	6.00%	6.00%
Total risk based capital to be Well Capitalized under Prompt Corrective Action Provisions, Ratio	10.00%	10.00%

Warrants_Additional_Informatio

Warrants - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Common Stock Warrant [Line Items]	'	'	'
Warrants exercised	37,500	'	'
Common stock warrants issued	162,500	'	'
Common stock warrant exercised	$10	'	'
Warrant expiration period	'10 years	'	'
Warrants issued	87,509	'	'
Warrants issued price per share	$19.50	'	'
Number of warrants outstanding	125,000	87,059	87,059
Dryades Bancorp, Inc [Member]	'	'	'
Common Stock Warrant [Line Items]	'	'	'
Warrants exercised	9,633	'	'
Number of warrants outstanding	77,426	'	'

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share based compensation expense	$1,202,000	$1,102,000	'
Income tax benefit	186,000	'	'
Share-based compensation arrangement by share-based payment award, options, outstanding, intrinsic value	16,100,000	'	'
Share-based compensation arrangement by share-based payment award, options, exercisable, intrinsic value	7,600,000	'	'
Share-based compensation arrangement by share-based payment award, options, exercises in period	-76,966	0	0
Stock Options [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share based compensation expense	700,000	500,000	300,000
Stock options term	'10 years	'	'
Shares available for restricted stock awards under approved compensation plans	300,000	'	'
Income tax benefit	200,000	200,000	100,000
Unrecognized compensation cost	1,800,000	'	'
Weighted-average period for compensation cost	'2 years	'	'
Minimum [Member] | Stock Options [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock vesting period	'3 years	'	'
Maximum [Member] | Stock Options [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock vesting period	'4 years	'	'
Restricted Stock [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock vesting period	'5 years	'	'
Shares vested	25,667	'	'
Unearned share-based compensation	0	'	'
Restricted shares issued	0	0	'
Share based compensation expense	$0	$0	$300,000

StockBased_Compensation_Summar

Stock-Based Compensation - Summary of Weighted-Average Assumptions Used for Option Awards Granted (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract]	'	'	'
Expected dividend yield	0.00%	0.00%	0.00%
Weighted-average expected volatility	36.68%	35.33%	31.50%
Weighted-average risk-free interest rate	1.73%	1.25%	2.87%
Expected option term (in years)	'6 years	'6 years 3 months 18 days	'6 years
Contractual term (in years)	'10 years	'10 years	'10 years
Weighted-average grant date fair value	$5.22	$5.49	$4.33

StockBased_Compensation_Summar1

Stock-Based Compensation - Summary of Stock Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'	'	'
Shares Outstanding, Beginning balance	809,017	443,658	215,000
Shares, Granted	139,650	378,692	229,657
Shares, Exercised	-76,966	0	0
Shares, Forfeited or expired	-16,600	-13,333	-999
Shares Outstanding, Ending balance	855,101	809,017	443,658
Weighted- Average Exercise Price, Beginning balance	$11.81	$11.11	$10.04
Options exercisable	374,535	289,444	270,599
Weighted- Average Exercise Price, Granted	$16.16	$14.69	$12.25
Weighted- Average Exercise Price, Exercised	$10.39	'	'
Weighted- Average Exercise Price, Forfeited or expired	$15.16	$14.43	$12.23
Weighted- Average Exercise Price, Ending balance	$13.48	$11.81	$11.11
Weighted- Average Exercise Price, Options exercisable	$11.94	$10.60	$10.53
Weighted average remaining contractual term (Years) Options outstanding	'7 years	'	'
Weighted average remaining contractual term (Years) Options exercisable	'6 years	'	'

StockBased_Compensation_Summar2

Stock-Based Compensation - Summarized Information about Stock Options Outstanding by Range of Exercise Prices (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule Of Stock Options [Line Items]	'	'	'	'
Number Outstanding	855,101	809,017	443,658	215,000
Weighted Average Exercise Price, Options Outstanding	$13.48	'	'	'
Weighted Average Remaining Contractual Life, Options Outstanding	'7 years	'	'	'
Number Exercisable	374,535	'	'	'
Weighted Average Exercise Price, Options Exercisable	$11.94	$10.60	$10.53	'
August 4, 2011 - September 30, 2011 [Member]	'	'	'	'
Schedule Of Stock Options [Line Items]	'	'	'	'
Range of Exercise Prices, Lower range	$10	'	'	'
Range of Exercise Prices, Upper range	$12.70	'	'	'
Number Outstanding	368,181	'	'	'
Weighted Average Exercise Price, Options Outstanding	$11.35	'	'	'
Weighted Average Remaining Contractual Life, Options Outstanding	'5 years	'	'	'
Number Exercisable	292,074	'	'	'
Weighted Average Exercise Price, Options Exercisable	$11.11	'	'	'
October 1, 2011 - December 31, 2011 [Member]	'	'	'	'
Schedule Of Stock Options [Line Items]	'	'	'	'
Range of Exercise Prices, Lower range	$14.20	'	'	'
Range of Exercise Prices, Upper range	$14.88	'	'	'
Number Outstanding	351,870	'	'	'
Weighted Average Exercise Price, Options Outstanding	$14.68	'	'	'
Weighted Average Remaining Contractual Life, Options Outstanding	'8 years	'	'	'
Number Exercisable	82,461	'	'	'
Weighted Average Exercise Price, Options Exercisable	$14.88	'	'	'
January 1, 2012 - March 31, 2012 [Member]	'	'	'	'
Schedule Of Stock Options [Line Items]	'	'	'	'
Range of Exercise Prices, Lower range	$15.88	'	'	'
Range of Exercise Prices, Upper range	$23.68	'	'	'
Number Outstanding	135,050	'	'	'
Weighted Average Exercise Price, Options Outstanding	$16.17	'	'	'
Weighted Average Remaining Contractual Life, Options Outstanding	'9 years	'	'	'
Number Exercisable	'	'	'	'
Weighted Average Exercise Price, Options Exercisable	'	'	'	'

Financial_Instruments_With_Off1

Financial Instruments With Off-Balance-Sheet Risk - Additional Information (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013
			Standby Letters of Credit [Member]	Standby Letters of Credit [Member]	Minimum [Member]	Maximum [Member]
					Standby Letters of Credit [Member]	Standby Letters of Credit [Member]
Financial Instruments [Line Items]	'	'	'	'	'	'
Line of credit facility, amount outstanding	$375,200,000	$348,600,000	'	'	'	'
Line of credit facility outstanding	'	'	106,500,000	92,200,000	'	'
Line of credit, expiration year	'	'	'	'	'2014	'2040
Net unamortized fees	'	'	200,000	54,000	'	'
Net unamortized cost	'	'	$300,000	$400,000	'	'

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Leased Assets [Line Items]	'	'	'
Operating lease, rent expense	$3.40	$3.40	$2.70
Minimum [Member]	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Operating lease period	'1 year	'	'
Renewal option period	'1 year	'	'
Maximum [Member]	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Operating lease period	'30 years	'	'
Renewal option period	'59 years	'	'

Commitments_and_Contingencies_2

Commitments and Contingencies - Summary of Annual Rental Payments (Detail) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Commitments And Contingencies Disclosure [Abstract]	'
2014	$3,119
2015	2,993
2016	3,011
2017	3,018
2018	2,697
Thereafter	41,259
Total annual rental payments under noncancelable leases	$56,097

Commitments_and_Contingencies_3

Commitments and Contingencies - Summary of Total Notional Amount of Loan Commitments and Standby Letters of Credit (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Commitments And Contingencies Disclosure [Abstract]	'	'
Standby letters of credit	$106,467	$92,274
Unused loan commitments	268,760	256,294
Total	$375,227	$348,568

RelatedParty_Transactions_Addi

Related-Party Transactions - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Related Party Transaction [Line Items]	'	'	'
Related party loans	$47.80	$66.60	'
Related party loans funded	36.4	'	'
Related Party loans repaid	55.2	'	'
Related party deposit	17.9	16.1	'
Building [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Rent incurred for lease	$0.20	$0.20	$0.20
Lease terms	'The lease also includes options for multiple five-year term extensions beyond the original lease expiration of October 2004	'	'
Lease expiration date	31-Oct-04	'	'
Building [Member] | Director [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Number of building leased	1	'	'

Employee_Benefits_Additional_I

Employee Benefits - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Compensation Related Costs [Abstract]	'	'	'
Defined benefit plan, Employer contributions	$1	$0.90	$0.40
Shares purchased under ESOP	50,000	'	'
ESOP plan description	'The leveraged ESOP allocates shares annually to eligible employee participants pro rata based on compensation.	'	'
Annual allocation percentage	'20% per year	'	'
ESOP compensation expense	$0.20	$0.20	$0.10

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Carrying Value and Fair Value Measurements of Financial Assets and Liabilities on Recurring Basis (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets	'	'
Available for sale securities	$277,719	$405,355
Derivative instruments	1,200	'
Liabilities	'	'
Derivative instruments	'	6,900
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	'	'
Assets	'	'
Available for sale securities	0	'
Liabilities	'	'
Derivative instruments	0	'
Significant Other Observable Inputs (Level 2) [Member]	'	'
Assets	'	'
Available for sale securities	277,719	405,355
Liabilities	'	'
Derivative instruments	4,317	6,854
Significant Unobservable Inputs (Level 3) [Member]	'	'
Assets	'	'
Available for sale securities	0	'
Total	12,172	26,747
Liabilities	'	'
Derivative instruments	0	'
Fair Value, Measurements, Recurring [Member]	'	'
Assets	'	'
Available for sale securities	277,719	405,355
Derivative instruments	1,157	'
Total	278,876	'
Liabilities	'	'
Derivative instruments	4,317	6,854
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	'	'
Assets	'	'
Available for sale securities	0	'
Derivative instruments	0	'
Total	0	'
Liabilities	'	'
Derivative instruments	0	'
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]	'	'
Assets	'	'
Available for sale securities	277,719	405,355
Derivative instruments	1,157	'
Total	278,876	'
Liabilities	'	'
Derivative instruments	4,317	6,854
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Assets	'	'
Available for sale securities	0	'
Derivative instruments	0	'
Total	0	'
Liabilities	'	'
Derivative instruments	$0	'

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments - Carrying Value and Fair Value Measurements of Financial Assets and Liabilities on Non Recurring Basis (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Measurements, Nonrecurring [Member]	'	'
Assets	'	'
Loans	$9,782	$21,313
OREO	2,390	5,434
Total	12,172	26,747
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Nonrecurring [Member]	'	'
Assets	'	'
Loans	0	'
OREO	0	'
Total	0	'
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Nonrecurring [Member]	'	'
Assets	'	'
Loans	0	'
OREO	0	'
Total	0	'
Significant Unobservable Inputs (Level 3) [Member]	'	'
Assets	'	'
Loans	9,782	21,313
OREO	2,390	5,434
Total	$12,172	$26,747

Fair_Value_of_Financial_Instru4

Fair Value of Financial Instruments - Carrying Value and Fair Value Measurements of Financial Instruments (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Short-term investments	$3,502	$9,541
Investment in short-term receivables	246,817	81,044
Investment securities available for sale	277,719	405,355
Investment securities held to maturity	94,904	'
Loans and loans held for sale	6,577	25,860
Cash surrender value of bank-owned life insurance	26,187	25,506
Derivative instruments	1,200	'
Deposits, noninterest-bearing	291,080	239,538
Deposits, interest-bearing	2,439,727	2,028,990
Short-term borrowings and repurchase agreements	75,957	36,287
Derivative instruments	'	6,900
Total Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Cash and due from banks	28,140	26,471
Short-term investments	3,502	9,541
Investment in short-term receivables	246,817	81,044
Investment securities available for sale	277,719	405,355
Investment securities held to maturity	90,966	'
Loans and loans held for sale	2,344,475	1,939,622
Cash surrender value of bank-owned life insurance	26,187	25,506
Deposits, noninterest-bearing	291,080	239,538
Deposits, interest-bearing	2,380,985	2,035,696
Short-term borrowings and repurchase agreements	84,382	58,087
Long-term borrowings	55,616	77,870
Derivative instruments	4,317	6,854
Carrying Amount [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Cash and due from banks	28,140	26,471
Short-term investments	3,502	9,541
Investment in short-term receivables	246,817	81,044
Investment securities available for sale	277,719	405,355
Investment securities held to maturity	94,904	'
Loans and loans held for sale	2,364,354	1,948,077
Cash surrender value of bank-owned life insurance	26,187	25,506
Derivative instruments	1,157	'
Deposits, noninterest-bearing	291,080	239,538
Deposits, interest-bearing	2,439,727	2,028,990
Short-term borrowings and repurchase agreements	84,382	58,087
Long-term borrowings	55,110	75,220
Derivative instruments	4,317	6,854
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Cash and due from banks	28,140	26,471
Short-term investments	3,502	9,541
Investment in short-term receivables	246,817	81,044
Investment securities available for sale	0	'
Investment securities held to maturity	0	'
Loans and loans held for sale	0	'
Cash surrender value of bank-owned life insurance	0	'
Deposits, noninterest-bearing	0	'
Deposits, interest-bearing	0	'
Short-term borrowings and repurchase agreements	0	'
Long-term borrowings	0	'
Derivative instruments	0	'
Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Cash and due from banks	0	'
Short-term investments	0	'
Investment securities available for sale	277,719	405,355
Investment securities held to maturity	90,966	'
Loans and loans held for sale	0	'
Cash surrender value of bank-owned life insurance	26,187	25,506
Deposits, noninterest-bearing	291,080	239,538
Deposits, interest-bearing	0	'
Short-term borrowings and repurchase agreements	84,382	58,087
Long-term borrowings	0	'
Derivative instruments	4,317	6,854
Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Cash and due from banks	0	'
Short-term investments	0	'
Investment securities available for sale	0	'
Loans and loans held for sale	2,344,475	1,939,622
Cash surrender value of bank-owned life insurance	0	'
Deposits, noninterest-bearing	0	'
Deposits, interest-bearing	2,380,985	2,035,696
Short-term borrowings and repurchase agreements	0	'
Long-term borrowings	55,616	77,870
Derivative instruments	$0	'

Parent_Company_Only_Financial_2

Parent Company Only Financial Statements - Schedule Of Balance Sheet (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Thousands, unless otherwise specified
Assets	'	'	'	'
Cash and due from banks	$28,140	$26,471	'	'
Goodwill	4,808	4,808	4,808	'
Other assets	23,781	20,915	'	'
Total assets	3,286,617	2,670,867	'	'
Liabilities and shareholders' equity	'	'	'	'
Long-term borrowings	55,110	75,220	'	'
Other liabilities	27,777	15,373	'	'
Total liabilities	2,904,758	2,422,765	'	'
Total shareholders' equity	381,859	248,102	223,516	131,033
Total liabilities and shareholders' equity	3,286,617	2,670,867	'	'
First NBC Bank Holding Company [Member]	'	'	'	'
Assets	'	'	'	'
Cash and due from banks	23,990	3,709	'	'
Goodwill	841	841	'	'
Investments in subsidiaries	355,068	260,618	'	'
Other assets	2,123	3,157	'	'
Total assets	382,022	268,325	'	'
Liabilities and shareholders' equity	'	'	'	'
Long-term borrowings	110	20,220	'	'
Other liabilities	53	4	'	'
Total liabilities	163	20,224	'	'
Total shareholders' equity	381,859	248,101	'	'
Total liabilities and shareholders' equity	$382,022	$268,325	'	'

Parent_Company_Only_Financial_3

Parent Company Only Financial Statements - Schedule Of Statement of Income (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating income	'	'	'	'	'	'	'	'	'	'	'
Total interest income	$34,437	$31,973	$29,034	$28,580	$28,394	$26,927	$25,781	$25,355	$124,024	$106,457	$79,014
Operating expense	'	'	'	'	'	'	'	'	'	'	'
Total interest expense	10,326	10,150	9,779	8,893	8,651	7,935	7,742	7,338	39,148	31,666	26,367
Income (loss) before income tax benefit and increase in equity in undistributed earnings of subsidiaries	7,689	4,792	4,408	4,271	5,880	5,164	6,344	4,497	21,160	21,885	14,341
Income tax benefit	5,867	5,673	4,198	4,013	-443	3,130	2,952	1,926	19,751	7,565	5,407
Net income	13,556	10,465	8,606	8,284	5,437	8,294	9,296	6,423	40,911	29,450	19,748
Preferred stock dividends and discount accretion	'	'	'	'	'	'	'	'	'	'	-580
Income available to common shareholders	13,461	10,403	8,511	8,189	4,967	8,051	9,202	6,210	40,564	28,430	18,068
First NBC Bank Holding Company [Member]	'	'	'	'	'	'	'	'	'	'	'
Operating income	'	'	'	'	'	'	'	'	'	'	'
Interest income	'	'	'	'	'	'	'	'	'	'	'
Dividend from bank subsidary	'	'	'	'	'	'	'	'	2,000	'	'
Total interest income	'	'	'	'	'	'	'	'	2,000	'	'
Operating expense	'	'	'	'	'	'	'	'	'	'	'
Interest expense	'	'	'	'	'	'	'	'	424	11	14
Other expense	'	'	'	'	'	'	'	'	856	431	188
Total interest expense	'	'	'	'	'	'	'	'	1,280	442	202
Income (loss) before income tax benefit and increase in equity in undistributed earnings of subsidiaries	'	'	'	'	'	'	'	'	720	-442	-202
Income tax benefit	'	'	'	'	'	'	'	'	-448	-155	-71
Income (loss) before equity in undistributed earnings of subsidiaries	'	'	'	'	'	'	'	'	1,168	-287	-131
Equity in undistributed earnings of subsidiaries	'	'	'	'	'	'	'	'	39,743	29,227	19,571
Net income	'	'	'	'	'	'	'	'	40,911	28,940	19,440
Preferred stock dividends and discount accretion	'	'	'	'	'	'	'	'	-347	-510	-1,372
Income available to common shareholders	'	'	'	'	'	'	'	'	$40,564	$28,430	$18,068

Parent_Company_Only_Financial_4

Parent Company Only Financial Statements - Schedule Of Statement of Cash Flow (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities	'	'	'
Net income	$40,911	$28,940	$19,440
Adjustments to reconcile net income to net cash (used in) provided by operating activities:	'	'	'
Deferred tax benefit	-19,937	-7,565	-5,407
Stock compensation	2,124	1,102	715
Changes in operating assets and liabilities:	'	'	'
Change in other assets	-5,168	1,540	-6,854
Change in other liabilities	15,125	-2,758	7,224
Net cash provided by (used in) operating activities	89,463	1,198	28,678
Investing activities	'	'	'
Net cash used in investing activities	-665,076	-454,155	-343,559
Financing activities	'	'	'
Repayment of borrowings	-41,910	-1,625	-21,220
Repayment of preferred stock	'	-1,644	-18,685
Proceeds from sale of preferred stock, net of offering costs	'	'	58,518
Proceeds from sale of common stock, net of offering costs	104,332	1,420	30,430
Dividends paid	-347	-510	-792
Net cash provided by financing activities	571,243	421,598	352,968
Net change in cash, due from banks, and short-term investments	-4,370	-31,359	38,087
Cash, due from banks, and short-term investments at beginning of period	36,012	67,371	29,284
Cash, due from banks, and short-term investments at end of period	31,642	36,012	67,371
First NBC Bank Holding Company [Member]	'	'	'
Operating activities	'	'	'
Net income	40,911	28,940	19,440
Adjustments to reconcile net income to net cash (used in) provided by operating activities:	'	'	'
Net income of subsidiaries	-39,743	-29,227	-19,571
Deferred tax benefit	-448	-155	-71
Stock compensation	1,155	97	715
Changes in operating assets and liabilities:	'	'	'
Change in other assets	1,481	-1,989	-762
Change in other liabilities	50	'	3
Net cash provided by (used in) operating activities	3,406	-2,334	-246
Investing activities	'	'	'
Capital contributed to subsidiary, net	-67,000	-16,600	-67,508
Net cash used in investing activities	-67,000	-16,600	-67,508
Financing activities	'	'	'
Proceeds from long-term borrowings	'	20,000	'
Repayment of borrowings	-20,110	-110	-110
Repayment of preferred stock	'	'	-18,685
Proceeds from sale of preferred stock, net of offering costs	'	'	58,518
Proceeds from sale of common stock, net of offering costs	104,332	1,420	30,430
Dividends paid	-347	-510	-792
Net cash provided by financing activities	83,875	20,800	69,361
Net change in cash, due from banks, and short-term investments	20,281	1,866	1,607
Cash, due from banks, and short-term investments at beginning of period	3,709	1,843	236
Cash, due from banks, and short-term investments at end of period	$23,990	$3,709	$1,843

Consolidated_Quarterly_Results2

Consolidated Quarterly Results of Operations - Summary of Quarterly Financial Data (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Total interest income	$34,437	$31,973	$29,034	$28,580	$28,394	$26,927	$25,781	$25,355	$124,024	$106,457	$79,014
Total interest expense	10,326	10,150	9,779	8,893	8,651	7,935	7,742	7,338	39,148	31,666	26,367
Net interest income	24,111	21,823	19,255	19,687	19,743	18,992	18,039	18,017	84,876	74,791	52,647
Provision for loan losses	2,400	2,400	2,400	2,600	4,800	1,800	1,800	2,635	9,800	11,035	8,010
Net interest income after provision for loan losses	21,711	19,423	16,855	17,087	14,943	17,192	16,239	15,382	75,076	63,756	44,637
Noninterest income	5,400	2,461	2,738	2,817	4,757	1,558	3,968	2,853	967	1,073	515
Noninterest expense	19,422	17,092	15,185	15,633	13,820	13,586	13,863	13,738	67,332	55,007	36,247
Income before income taxes	7,689	4,792	4,408	4,271	5,880	5,164	6,344	4,497	21,160	21,885	14,341
Income tax (benefit) expense	-5,867	-5,673	-4,198	-4,013	443	-3,130	-2,952	-1,926	-19,751	-7,565	-5,407
Net income	13,556	10,465	8,606	8,284	5,437	8,294	9,296	6,423	40,911	29,450	19,748
Less net income attributable to noncontrolling interest	-62	-62	-95	-95	-375	-17	'	-118	'	510	308
Net income attributable to Company	13,556	10,465	8,606	8,284	5,062	8,277	9,296	6,305	40,911	28,940	19,440
Less preferred stock dividends	-95	-62	-95	-95	-95	-226	-94	-95	-347	-510	-792
Income available to common shareholders	$13,461	$10,403	$8,511	$8,189	$4,967	$8,051	$9,202	$6,210	$40,564	$28,430	$18,068
Earnings per common share-basic	$0.71	$0.55	$0.51	$0.59	$0.36	$0.58	$0.66	$0.45	$2.38	$2.04	$1.55
Earnings per common share-diluted	$0.69	$0.54	$0.49	$0.58	$0.35	$0.57	$0.65	$0.44	$2.32	$2.02	$1.54