Intervest Bancshares (IBCA) 10-Q 5 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 31, 2013
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Entity Registrant Name	'INTERVEST BANCSHARES CORP	'
Entity Central Index Key	'0000927807	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Non-accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	21,917,823

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
ASSETS	'	'
Cash and due from banks	$25,292	$57,641
Federal funds sold and other short-term investments	4,961	2,754
Total cash and cash equivalents	30,253	60,395
Time deposits with banks	5,370	5,170
Securities available for sale (estimated fair value of $1,016 and $1,000, respectively)	1,016	1,000
Securities held to maturity (estimated fair value of $410,304 and $442,166, respectively)	416,321	443,777
Federal Reserve Bank and Federal Home Loan Bank stock, at cost	8,237	8,151
Loans receivable (net of allowance for loan losses of $26,777 and $28,103, respectively)	1,073,500	1,079,363
Accrued interest receivable	4,735	5,191
Loan fees receivable	2,511	3,108
Premises and equipment, net	4,129	3,878
Foreclosed real estate (net of valuation allowance of $2,123 and $5,339, respectively)	12,019	15,923
Deferred income tax asset	21,774	29,234
Other assets	4,374	10,602
Total assets	1,584,239	1,665,792
Deposits:	'	'
Noninterest-bearing demand deposit accounts	5,138	5,130
Interest-bearing deposit accounts:	'	'
Checking (NOW) accounts	15,816	15,185
Savings accounts	9,670	9,601
Money market accounts	370,367	395,825
Certificate of deposit accounts	897,412	936,878
Total deposit accounts	1,298,403	1,362,619
Long-term debt - subordinated debentures (capital securities)	56,702	56,702
Accrued interest payable on long term debt	463	6,228
Accrued interest payable on deposits	1,398	2,379
Mortgage escrow funds payable	27,003	17,743
Official checks outstanding	5,224	7,003
Other liabilities	2,758	2,171
Total liabilities	1,391,951	1,454,845
STOCKHOLDERS' EQUITY	'	'
Preferred stock ($1.00 par value; 300,000 shares authorized; 25,000 shares issued and outstanding at December 31, 2012)	'	25
Additional paid-in-capital, preferred	'	24,975
Preferred stock discount	'	-376
Common stock ($1.00 par value; 62,000,000 shares authorized; 21,916,623 and 21,589,589 shares issued and outstanding, respectively)	21,917	21,590
Additional paid-in-capital, common	87,066	85,726
Unearned compensation on restricted common stock awards	-1,447	-715
Retained earnings	84,752	79,722
Total stockholders' equity	192,288	210,947
Total liabilities and stockholders' equity	$1,584,239	$1,665,792

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Statement Of Financial Position [Abstract]	'	'
Securities available for sale estimated fair value	$1,016	$1,000
Securities held to maturity, estimated fair value	410,304	442,166
Loans receivable, allowance for loan losses	26,777	28,103
Foreclosed real estate, valuation allowance	$2,123	$5,339
Preferred stock, par value	$1	$1
Preferred stock, shares authorized	300,000	300,000
Preferred stock, issued	25,000	25,000
Preferred stock, outstanding	'	25,000
Common stock, par value	$1	$1
Common stock, shares authorized	62,000,000	62,000,000
Common stock, shares issued	21,916,623	21,589,589
Common stock, shares outstanding	21,916,623	21,589,589

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Earnings (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
INTEREST AND DIVIDEND INCOME	'	'	'	'
Loans receivable	$14,486,000	$17,351,000	$44,230,000	$53,202,000
Securities	1,121,000	1,719,000	3,213,000	6,255,000
Other interest-earning assets	17,000	12,000	53,000	29,000
Total interest and dividend income	15,624,000	19,082,000	47,496,000	59,486,000
INTEREST EXPENSE	'	'	'	'
Deposits	6,392,000	8,654,000	19,810,000	28,214,000
Subordinated debentures - capital securities	402,000	466,000	1,277,000	1,392,000
FHLB advances and all other borrowed funds	'	103,000	'	358,000
Total interest expense	6,794,000	9,223,000	21,087,000	29,964,000
Net interest and dividend income	8,830,000	9,859,000	26,409,000	29,522,000
Provision (credit) for loan losses	250,000	'	-1,500,000	'
Net interest and dividend income after provision (credit) for loan losses	8,580,000	9,859,000	27,909,000	29,522,000
NONINTEREST INCOME	'	'	'	'
Income from the early repayment of mortgage loans	619,000	765,000	1,909,000	2,730,000
Income from mortgage lending activities	455,000	332,000	1,112,000	793,000
Customer service fees	100,000	90,000	289,000	352,000
Impairment writedowns on investment securities	-273,000	'	-964,000	-157,000
Total noninterest income	901,000	1,187,000	2,346,000	3,718,000
NONINTEREST EXPENSES	'	'	'	'
Salaries and employee benefits	2,081,000	2,122,000	6,394,000	6,271,000
Occupancy and equipment, net	554,000	523,000	1,632,000	1,566,000
Data processing	97,000	83,000	271,000	284,000
Professional fees and services	327,000	370,000	1,095,000	1,129,000
Stationery, printing, supplies, postage and delivery	61,000	78,000	207,000	200,000
FDIC insurance	318,000	581,000	1,129,000	1,816,000
General insurance	153,000	143,000	455,000	433,000
Director and committee fees	85,000	103,000	272,000	317,000
Advertising and promotion	7,000	5,000	17,000	12,000
Real estate activities expense (income), net	212,000	883,000	-1,120,000	1,822,000
Provision for real estate losses	250,000	1,025,000	955,000	2,933,000
All other	179,000	152,000	482,000	445,000
Total noninterest expenses	4,324,000	6,068,000	11,789,000	17,228,000
Earnings before provision for income taxes	5,157,000	4,978,000	18,466,000	16,012,000
Provision for income taxes	2,300,000	2,300,000	8,179,000	7,320,000
Net earnings	2,857,000	2,678,000	10,287,000	8,692,000
Preferred stock dividend requirements and discount amortization	-269,000	-453,000	-1,057,000	-1,345,000
Net earnings available to common stockholders	$2,588,000	$2,225,000	$9,230,000	$7,347,000
Basic earnings per common share	$0.12	$0.10	$0.42	$0.34
Diluted earnings per common share	$0.12	$0.10	$0.42	$0.34
Cash dividends per common share	'	'	'	'

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Changes in Stockholders' Equity (USD $)	Total	Preferred Stock [Member]	Additional Paid-In-Capital, Preferred [Member]	Preferred Stock Discount [Member]	Common Stock [Member]	Additional Paid-In-Capital, Common [Member]	Unearned Compensation - Restricted Stock [Member]	Retained Earnings [Member]
Balance at beginning of period at Dec. 31, 2011	'	$25,000	$24,975,000	($762,000)	$21,125,000	$84,765,000	($483,000)	$67,886,000
Balance at beginning of period (in shares) at Dec. 31, 2011	'	25,000	'	'	21,125,289	'	'	'
Preferred stockholder's equity	24,528,000	'	'	'	'	'	'	'
Preferred stockholder's equity, shares	25,000	'	'	'	'	'	'	'
Net earnings	8,692,000	'	'	'	'	'	'	8,692,000
Amortization of preferred stock discount	'	'	'	290,000	'	'	'	'
Issuance of 330,700 and 465,400 shares of restricted stock	'	'	'	'	466,000	884,000	-1,350,000	'
Redemption of preferred stock	'	'	0	'	'	'	'	'
Common stockholders' equity	182,580,000	'	'	'	'	'	'	'
Issuance of 330,700 and 465,400 shares of restricted stock, shares	'	'	'	'	465,400	465,400	465,400	'
Amortization of unearned compensation to compensation expense	'	'	'	'	'	'	827,000	'
Redemption of preferred stock, Shares	'	0	'	'	'	'	'	'
Common stockholders' equity, shares	21,589,589	'	'	'	'	'	'	'
Preferred stock discount amortization	-1,345,000	'	'	'	'	'	'	-290,000
Issuance of 14,967 and 100 shares upon exercise of stock options (In Shares)	'	'	'	'	100	100	'	'
Forfeiture of 18,633 and 1,200 shares of restricted stock	'	'	'	'	-1,000	-2,000	'	'
Forfeiture of 18,633 and 1,200 shares of restricted stock, shares	'	'	'	'	-1,200	1,200	'	'
Excess income tax benefit from vesting of restricted stock	0	'	'	'	'	'	'	'
Compensation expense related to grants of stock options	'	'	'	'	'	61,000	'	'
Total stockholders' equity at end of period at Sep. 30, 2012	207,108,000	25,000	24,975,000	-472,000	21,590,000	85,708,000	-1,006,000	76,288,000
Balance at end of period (in shares) at Sep. 30, 2012	21,614,589	25,000	'	'	21,589,589	'	'	'
Balance at beginning of period at Dec. 31, 2012	210,947,000	25,000	24,975,000	-376,000	21,590,000	85,726,000	-715,000	79,722,000
Balance at beginning of period (in shares) at Dec. 31, 2012	'	25,000	'	'	21,589,589	'	'	'
Preferred stockholder's equity, shares	25,000	'	'	'	'	'	'	'
Net earnings	10,287,000	'	'	'	'	'	'	10,287,000
Amortization of preferred stock discount	'	'	'	376,000	'	'	'	'
Issuance of 330,700 and 465,400 shares of restricted stock	'	'	'	'	331,000	1,157,000	-1,488,000	'
Redemption of preferred stock	'	-25,000	-24,975,000	'	'	'	'	'
Common stockholders' equity	192,288,000	'	'	'	'	'	'	'
Cash dividend declared and paid on preferred stock	'	'	'	'	'	'	'	-5,068,000
Issuance of 330,700 and 465,400 shares of restricted stock, shares	'	'	'	'	330,700	330,700	330,700	'
Amortization of unearned compensation to compensation expense	'	'	'	'	'	'	756,000	'
Redemption of preferred stock, Shares	'	-25,000	'	'	'	'	'	'
Common stockholders' equity, shares	21,916,623	'	'	'	'	'	'	'
Discount from redemption of preferred stock	'	'	'	'	'	'	'	187,000
Issuance of 14,967 and 100 shares upon exercise of stock options	'	'	'	'	15,000	39,000	'	'
Preferred stock discount amortization	-1,057,000	'	'	'	'	'	'	-376,000
Issuance of 14,967 and 100 shares upon exercise of stock options (In Shares)	14,967	'	'	'	14,967	14,967	'	'
Forfeiture of 18,633 and 1,200 shares of restricted stock	'	'	'	'	-19,000	-40,000	'	'
Forfeiture of 18,633 and 1,200 shares of restricted stock, shares	'	'	'	'	-18,633	18,633	'	'
Excess income tax benefit from vesting of restricted stock	150,000	'	'	'	'	150,000	'	'
Compensation expense related to grants of stock options	'	'	'	'	'	34,000	'	'
Total stockholders' equity at end of period at Sep. 30, 2013	$192,288,000	$0	'	'	$21,917,000	$87,066,000	($1,447,000)	$84,752,000
Balance at end of period (in shares) at Sep. 30, 2013	21,916,623	'	'	'	21,916,623	'	'	'

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Changes in Stockholders' Equity (Parenthetical)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Issuance of common stock option	14,967	'
Common Stock [Member]	'	'
Issuance of shares of restricted stock issued, shares	330,700	465,400
Issuance of common stock option	14,967	100
Forfeiture of 18,633 and 1,200 shares of restricted stock	-18,633	-1,200
Additional Paid-In-Capital, Common [Member]	'	'
Issuance of shares of restricted stock issued, shares	330,700	465,400
Issuance of common stock option	14,967	100
Forfeiture of 18,633 and 1,200 shares of restricted stock	18,633	1,200
Unearned Compensation - Restricted Stock [Member]	'	'
Issuance of shares of restricted stock issued, shares	330,700	465,400

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
OPERATING ACTIVITIES	'	'
Net earnings	$10,287	$8,692
Adjustments to reconcile net earnings to net cash provided by operating activities:	'	'
Depreciation and amortization	258	260
(Credit) provisions for loan and real estate losses, net	-545	2,933
Deferred income tax expense	7,460	6,844
Compensation expense related to grants of common stock and options	731	885
Amortization of deferred debenture offering costs	28	28
Amortization of premiums (accretion) of discounts and deferred loan fees, net	610	299
Net gain on sales of foreclosed real estate	-820	'
Impairment writedowns on investment securities	964	157
Net (decrease) increase in accrued interest payable on debentures	-5,765	1,406
Net (decrease) increase in official checks outstanding	-1,779	5,385
Net decrease in loan fees receivable	597	755
Net change in all other assets and liabilities	7,716	1,842
Net cash provided by operating activities	19,742	29,486
INVESTING ACTIVITIES	'	'
Maturities and calls of securities held to maturity	99,705	501,870
Purchases of securities held to maturity	-75,051	-243,486
Purchases of securities available for sale	-16	'
Purchases of interest-earning time deposits with banks	-200	-2,200
(Purchases) redemptions of FRB and FHLB stock, net	-86	792
Repayments of loans receivable, net of originations	7,337	6,543
Proceeds from sales of foreclosed real estate	3,569	3,544
Purchases of premises and equipment, net	-509	-75
Net cash provided by investing activities	34,749	266,988
FINANCING ACTIVITIES	'	'
Net decrease in deposits	-64,216	-229,815
Net increase in mortgage escrow funds payable	9,260	8,246
Net decrease in FHLB advances - original terms of more than 3 months	'	-10,500
Redemption of preferred stock	-24,813	'
Cash dividends paid to preferred stockholders	-5,068	'
Proceeds from issuance of common stock upon exercise of options	54	'
Excess tax benefit from exercise of options and vesting of restricted stock	150	'
Net cash used in financing activities	-84,633	-232,069
Net (decrease) increase in cash and cash equivalents	-30,142	64,405
Cash and cash equivalents at beginning of period	60,395	29,863
Cash and cash equivalents at end of period	30,253	94,268
SUPPLEMENTAL DISCLOSURES	'	'
Cash paid for interest	27,805	30,264
Cash paid for income taxes	900	733
Loans transferred to foreclosed real estate	3,040	1,457
Loans originated to finance sales of foreclosed real estate	3,240	1,400
Preferred stock dividend requirements and amortization of related discount	$1,057	$1,345

Summary_of_Significant_Account

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	Note 1 - Summary of Significant Accounting Policies
	General
	Intervest Bancshares Corporation (“IBC”) is the parent company of Intervest National Bank (“INB”). References in this report to “we,” “us” and “our” refer to these entities on a consolidated basis, unless otherwise specified. For a description of our business, see note 1 to the financial statements in our 2012 Annual Report on Form 10-K (“2012 10-K”). Our accounting and reporting policies conform to U.S. generally accepted accounting principles (GAAP) and general practices within the banking industry and are described in note 1 to the financial statements in our 2012 10-K, as updated by the information in this Form 10-Q.
	Principles of Consolidation and Basis of Presentation
	The condensed consolidated financial statements (“financial statements”) in this report have not been audited except for information derived from our audited 2012 consolidated financial statements and notes thereto and should be read in conjunction with our 2012 10-K. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted in this report pursuant to the rules and regulations of the Securities and Exchange Commission.
	Use of Estimates
	In preparing our financial statements, we are required to make estimates and assumptions that affect the reported amounts of assets, liabilities and disclosure of contingent liabilities as of the date of the financial statements, and revenues and expenses during the reporting periods. Actual results could differ from those estimates. Estimates that are particularly susceptible to significant change currently relate to the determination of our allowance for loan losses, valuation allowance for real estate losses, other than temporary impairment assessments of our security investments and the need for and amount of a valuation allowance for our deferred tax asset. These estimates involve a higher degree of complexity and subjectivity and may require assumptions about highly uncertain matters. Current market conditions increase the risk and complexity of the judgments in these estimates. In our opinion, all material adjustments necessary for a fair presentation of our financial condition and results of operations for the interim periods presented in this report have been made. These adjustments are of a normal recurring nature. All significant intercompany balances and transactions have been eliminated in consolidation. Our results of operations for the interim periods are not necessarily indicative of results that may be expected for the entire year or any other interim period.
	Recent Accounting Standards Update
	In July 2012, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (ASU) 2012-02, “Testing Indefinite-Lived Intangible Assets for Impairment,” which, among other things, gives an entity the option to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that an indefinite-lived intangible asset is impaired. We adopted this ASU on January 1, 2013, and since we do not have intangible assets, it had no impact on our financial statements.
	In January 2013, the FASB issued ASU No. 2013-01, “Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities,” which limits the scope of the new balance sheet offsetting disclosures in ASU 2011-11 to derivatives, repurchase agreements, and securities lending transactions to the extent that they are (1) offset in the financial statements or (2) subject to an enforceable master netting arrangement or similar agreement. We adopted this ASU on February 1, 2013 and it had no impact on our financial statements.
	In February 2013, the FASB Issued ASU No. 2013-02, “Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income,” which requires entities to present information about reclassification adjustments from accumulated other comprehensive income in their annual financial statements in a single note or on the face of the financial statements. We adopted this ASU on March 1, 2013 and it had no impact on our financial statements.
	In February 2013, the FASB Issued ASU No. 2013-04, “Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation Is Fixed at the Reporting Date”. ASU 2013-04 provides guidance for the recognition, measurement, and disclosure of obligations resulting from joint and several liability arrangements for obligations within the scope of this ASU, which is effective January 1, 2014. Upon adoption, we do not expect this ASU to impact our financial statements.
	In July 2013, the FASB issued ASU 2013-11, “Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists,” which among other things, require an unrecognized tax benefit, or a portion of an unrecognized tax benefit, to be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, except as denoted within the ASU. The amendments in this ASU are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. We are currently evaluating the impact of ASU 2013-11 on our financial statements.
	In July 2013, the FASB issued ASU No. 2013-10, “Inclusion of the Fed Funds Effective Swap Rate (or Overnight Index Swap Rate) as a Benchmark Interest Rate for Hedge Accounting Purposes”. ASU No. 2013-10 permits the use of the Fed Funds Effective Swap Rate (OIS) to be used as a U.S. benchmark interest rate for hedge account purposes. The amendment is effective prospectively for qualifying new or redesiginated hedging relationships entered into on or after July 17, 2013. The adoption of ASU No. 2013-10 did have an impact on our financial statements.
	Recent Regulatory Developments
	Basel III Legislation
	On July 2, 2013, the FRB approved the final rules implementing the Basel Committee on Banking Supervision’s capital guidelines for U.S. banks. Under the final rules, minimum requirements will increase for both the quantity and quality of capital held by INB. The rules include a new common equity Tier 1 capital to risk-weighted assets ratio of 4.5% and a common equity Tier 1 capital conservation buffer of 2.5% of risk-weighted assets. The final rules also raise the minimum ratio of Tier 1 capital to risk-weighted assets from 4.0% to 6.0% and require a minimum leverage ratio of 4.0%. The final rules also implement strict eligibility criteria for regulatory capital instruments. On July 9, 2013, the FDIC also approved, as an interim final rule, the regulatory capital requirements for U.S. banks, following the actions of the FRB. The FDIC’s rule is identical in substance to the final rules issued by the FRB.
	The phase-in period for the final rules will begin for INB on January 1, 2015, with full compliance with all of the final rule’s requirements phased in over a multi-year schedule. We are currently evaluating the provisions of the final rules and their expected impact on us.

Securities_Held_to_Maturity_an

Securities Held to Maturity and Available for Sale	9 Months Ended
	Sep. 30, 2013
Investments Debt And Equity Securities [Abstract]	'
Securities Held to Maturity and Available for Sale	'
	Note 2- Securities Held to Maturity and Available for Sale
	The carrying value (amortized cost) and estimated fair value of securities held to maturity are as follows:
	($ in thousands)		Number of				Amortized				Gross				Gross				Estimated				Wtd-Avg				Wtd-Avg				Wtd-Avg
			Securities				Cost				Unrealized				Unrealized				Fair				Yield				Expected				Remaining
											Gains				Losses				Value								Life				Maturity
	At September 30, 2013
	U.S. government agencies (1)			176				$333,124			$	490			$	4,163			$	329,451				0.93%				2.9 Yrs				4.1 Yrs
	Residential mortgage-backed (2)			56				80,061				225				640				79,646				1.97%				4.6 Yrs				15.0 Yrs
	State and municipal			1				532				-				3				529				1.25%				3.5 Yrs				3.5 Yrs
	Corporate (3)			8				2,604				-				1,926				678				2.00%				19.5 Yrs				20.2 Yrs
				241				$416,321			$	715			$	6,732			$	410,304				1.14%				3.3Yrs				6.3 Yrs
	At December 31, 2012
	U.S. government agencies (1)			165				$355,244			$	1,109			$	233			$	356,120				0.87%				1.6 Yrs				4.6 Yrs
	Residential mortgage-backed (2)			48				84,279				651				72				84,858				1.76%				3.3 Yrs				17.3 Yrs
	State and municipal			1				533				-				3				530				1.25%				4.2 Yrs				4.3 Yrs
	Corporate (3)			8				3,721				-				3,063				658				2.11%				20.3 Yrs				20.9 Yrs
				222				$443,777			$	1,760			$	3,371			$	442,166				1.05%				2.0 Yrs				7.1 Yrs
	-1	Consist of debt obligations of U.S. government sponsored agencies (GSEs) - Federal Home Loan Bank (FHLB), Federal Farm Credit Bank (FFCB), Federal National Mortgage Association (FNMA) and Federal Home Loan Mortgage Corporation (FHLMC), which are federally chartered corporations privately owned by shareholders. GSE securities carry no explicit U.S. government guarantee of creditworthiness. Neither principal nor interest payments are guaranteed by the U.S. government nor do they not constitute a debt or obligation of the U.S. government or any of its agencies or instrumentalities other than the applicable GSE. In September 2008, FNMA and FHLMC were placed under U.S. government conservatorship.
	-2	At September 30, 2013, consisted of $14.5 million of Government National Mortgage Association (GNMA) pass-through certificates, $46.3 million of FNMA participation certificates and $19.3 million of FHLMC participation certificates. At December 31, 2012, consisted of $18.7 million of GNMA pass-through certificates, $40.0 million of FNMA participation certificates and $25.6 million of FHLMC participation certificates. The GNMA pass-through certificates are guaranteed as to the payment of principal and interest by the full faith and credit of the U.S. government while the FNMA and FHLMC certificates have an implied guarantee by such agency as to principal and interest payments.
	-3	Consist of variable-rate pooled trust preferred securities backed by obligations of companies in the banking industry. Amortized cost at September 30, 2013 and December 31, 2012 is reported net of other than temporary impairment charges of $5.2 million and $4.2 million, respectively.
	The estimated fair values of securities held to maturity with gross unrealized losses segregated between securities that have been in a continuous unrealized loss position for less than twelve months at the respective dates and those that have been in a continuous unrealized loss position for twelve months or longer are summarized as follows:
							Less Than Twelve Months								Twelve Months or Longer								Total
	($ in thousands)		Number of				Estimated				Gross				Estimated				Gross				Estimated				Gross
			Securities				Fair				Unrealized				Fair				Unrealized				Fair				Unrealized
							Value				Losses				Value				Losses				Value				Losses
	At September 30, 2013
	U.S. government agencies			137				$257,171				$4,163				$        -				$        -				$257,171				$4,163
	Residential mortgage-backed			38				49,827				623				917				17				50,744				640
	State and municipal			1				529				3				-				-				529				3
	Corporate			8				-				-				678				1,926				678				1,926
				184				$307,527				$4,789				$1,595				$1,943				$309,122				$6,732
	At December 31, 2012
	U.S. government agencies			53				$129,365				$   233				$        -				$        -				$129,365				$   233
	Residential mortgage-backed			14				24,481				72				-				-				24,481				72
	State and municipal			1				530				3				-				-				530				3
	Corporate			8				-				-				658				3,063				658				3,063
				76				$154,376				$   308				$   658				$3,063				$155,034				$3,371
	Nearly all of the securities we own are investment grade and have either fixed interest rates or have predetermined scheduled interest rate increases and nearly all have call or prepayment features that allow the issuer to repay all or a portion of the security at par before its stated maturity without penalty. In general, as interest rates rise, the estimated fair value of fixed-rate securities will decrease; as interest rates fall, their value will increase. We generally view changes in fair value caused by changes in interest rates as temporary, which is consistent with our experience.
	INB, which holds the portfolio, has the ability and intent to hold all of these investments for a period of time sufficient for the estimated fair value of the securities with unrealized losses to recover, which may be at the time of maturity. Historically, INB has always recovered the cost of its investments in securities upon maturity. We view all the gross unrealized losses related to the agency, mortgaged-backed and state and municipal securities to be temporary for the reasons noted above. The estimated fair values disclosed in the preceding table for U.S. government agency, mortgage-backed and state and municipal securities are obtained from third-party brokers who provide quoted prices derived from active markets for identical or similar securities.
	INB also owns trust preferred securities that are classified as held to maturity. The investments in these debt securities represent beneficial interests in securitized financial assets that have contractual cash flows. They consist of mezzanine-class, variable-rate (indexed to 3 month libor) pooled trust preferred securities backed by debt obligations of companies in the banking industry. At the time of purchase, these securities were investment grade rated. The current estimated fair values of these securities are depressed due to various reasons, including the weak economy, the financial condition of a large number of the issuing banks, a number of issuing banks that are no longer in business and restrictions that have been or can be placed on the payment of interest by regulatory agencies, all of which have severely reduced the demand for these securities and rendered their trading market inactive. There has been an adverse change in the estimated future cash flows from these securities due to the reasons cited above such that all of these securities have been other than temporarily impaired (OTTI) to varying degrees as denoted in the table that follows.
	The following table provides various information regarding trust preferred securities.
	($ in thousands)		Credit		Cost				Write				Adj.				Estimated				Unrealized				% of Collateral								# of	Discount (4)				PV of
									Downs				Cost				Fair																Banks					Expected
	Cusip # (1)		Rating (1)		Basis				-2				Basis				Value (3)				Loss				Defaulted				Deferred				in Pool	Margin		Rate		Cash Flows
	At September 30, 2013
	74041PAEO		C			$  998				$   (918)				$     80				$  29				$    (51)				43.20%				14.80%			39		1.92%		5.22%		$   338
	74040XAD6		CC			995				-485				510				176				(334)				17.20%				9.80%			54		1.64%		5.17%		978
	74040XAE4		CC			973				-462				511				176				(335)				17.20%				9.80%			54		1.85%		5.39%		953
	74040XAE4		CC			973				-462				511				176				(335)				17.20%				9.80%			54		1.85%		5.39%		953
	74040YAF9		CC-			900				-767				133				33				(100)				29.00%				5.90%			58		1.88%		5.32%		769
	74040YAE2		CC-			919				-787				132				33				(99)				29.00%				5.90%			58		1.70%		5.14%		785
	74041UAE9		C+			1,021				-658				363				27				(336)				8.00%				29.00%			64		1.36%		4.78%		725
	74041UAE9		C+			1,022				-658				364				28				(336)				8.00%				29.00%			64		1.39%		4.81%		724
						$7,801				($5,197)				$2,604				$678				$(1,926)																	$6,225
	At December 31, 2012
	74041PAEO		C			$  999				$   (797)				$   202				$  31				$    (171)				39.23%				13.76%			39		1.92%		4.04%		$   348
	74040XAD6		C+			1,010				-316				694				180				(514)				16.31%				9.19%			54		1.64%		3.97%		989
	74040XAE4		C+			988				-294				694				180				(514)				16.31%				9.19%			54		1.85%		4.18%		959
	74040XAE4		C+			988				-294				694				180				(514)				16.31%				9.19%			54		1.85%		4.18%		959
	74040YAF9		C			952				-718				234				32				(202)				27.24%				13.28%			58		1.88%		4.04%		642
	74040YAE2		C			972				-737				235				32				(203)				27.24%				13.28%			58		1.70%		3.86%		655
	74041UAE9		C+			1,022				-539				483				11				(472)				7.80%				31.17%			64		1.36%		3.61%		638
	74041UAE9		C+			1,023				-538				485				12				(473)				7.80%				31.17%			64		1.39%		3.64%		636
					$7,954				($4,233)				$3,721				$658				$(3,063)																	$5,826
(1) All of these securities were on cash basis accounting because INB is currently not receiving all scheduled contractual interest payments on these securities. A large portion of the contractual cash flows for the interest payments on these securities are being redirected to a more senior class of bondholders to pay down the principal balance on the more senior class faster. This occurs when deferral and default activity reduces the security’s underlying performing collateral to a level where a predetermined coverage test fails and requires cash flows from interest payments to be redirected to a senior class of security holders. If no additional deferrals or defaults occur, such test will eventually be met again through the redirection of the cash flow and cash interest payments would resume on INB’s bonds, although no assurance can be given as to the amount and timing of the resumption, if any. In the first nine months of 2013, INB received payments on cusips# 74040XAD6, 74040XAE4, 74040YAF9 and 74040YAE2 totaling approximately $153,000. The credit rating represents a composite rating derived from third party credit rating agencies (Moody’s and Fitch).
(2) Writedowns are derived based on analysis of various factors and consider the difference between the book value of the security and the projected present value of the security’s cash flows as indicated per an analysis performed using guidance prescribed by GAAP.
Notes to the preceding table continued:
(3) Obtained from Moody’s pricing service, which uses a complex valuation model that factors in numerous assumptions and data, including anticipated discounts related to illiquid trading markets, credit and interest rate risk, which under GAAP would be considered Level 3 inputs. INB believes that the actual values that would be realized in an orderly market under normal credit conditions between a willing buyer and seller would approximate the projected present value (PV) of the securities’ cash flows and therefore, these estimated fair values are used for disclosure purposes only and are not used for calculating and recording impairment. INB also has the intent and the ability to retain these trust preferred securities until maturity and currently has no intention of selling them. We view the gross unrealized losses related to these securities to be temporary.
(4) In determining whether there is OTTI, INB relies on a cash flow analysis as prescribed under GAAP (ASC 320-10-35) and prepared by a third party specialist to determine whether conditions are such that the projected cash flows are insufficient to recover INB’s principal investment. The basic methodology under GAAP is to compare the present value of the cash flows that are derived from assumptions made with respect to deferrals, defaults and prepayments from quarter to quarter. A decline in the present value versus that for the previous quarter is considered to be an adverse change. The discount margin in the table above represents the incremental credit spread used to derive the discount rate for present value computations. Consistent with GAAP, we analyze the specific credit characteristics of the collateral underlying each individual security to develop the deferral/default assumptions for estimated cash flows. This analysis consists of examining available data regarding trends in earnings and capital and problem asset ratios of each bank in the collateral pool in order to estimate their capacity to continue principal and interest payments on the investments we own. In order to estimate the expected cash flows, we focused on each bank’s Texas ratio, which is defined as nonperforming assets plus 90 day past due loans divided by tangible equity plus loan loss reserves. We concluded that banks with Texas ratios of 75% or more may experience greater difficulties in making payments. Based on our judgment, we determined and used the following assumptions in projecting cash flows: for those banks that were in default, we assumed no cash flows, for those banks that had deferred payments, we assumed a 15% recovery after a 2 year lag, and for banks that were paying we assumed prepayments of 1% annually and 100% at maturity and annual defaults of 75 basis points. It should be noted that the results of any discounted cash flow analysis are significantly affected by variables such as the estimate of the probability of default, discount rates, prepayment rates and the creditworthiness of the underlying issuers. Therefore, changes in any of these assumptions could cause the results of our cash flow models and OTTI assessments to deviate and result in different conclusions.
The table below provides a cumulative roll forward of credit losses recognized on securities held to maturity for the periods indicated.
		Quarter Ended September 30,								Nine-Months Ended September 30,
($ in thousands)		2013				2012				2013				2012
Balance at beginning of period			$4,924				$3,808				$4,233				$3,651
Additional credit losses on debt securities for which OTTI was previously recognized			273				-				964				157
Balance at end of period			$5,197				$3,808				$5,197				$3,808
The following table is a summary of the carrying value (amortized cost) and fair value of securities held to maturity as of September 30, 2013, by remaining period to contractual maturity (ignoring earlier call dates, if any). Actual maturities may differ from contractual maturities because certain security issuers have the right to call or prepay their obligations. The amounts reported in the table below do not consider the effects of possible prepayments or unscheduled repayments of the securities held to maturity portfolio.
($ in thousands)		Amortized				Estimated				Wtd-Avg
		Cost				Fair Value				Yield
Due in one year or less			$  17,094				$    17,196				1.24%
Due after one year through five years			243,465				241,627				0.85
Due after five years through ten years			98,322				96,382				1.27
Due after ten years			57,440				55,099				2.09
			$416,321				$410,304				1.14%
At September 30, 2013 and December 31, 2012, the carrying value of securities available for sale amounted to approximately $1.0 million, which also approximated estimated fair value. The investment represented approximately 91,210 and 90,000 shares owned at September 30, 2013 and December 31, 2012, respectively, in an intermediate bond fund that holds securities that are deemed to be qualified under the Community Reinvestment Act.

Loans_Receivable

Loans Receivable	9 Months Ended
	Sep. 30, 2013
Receivables [Abstract]	'
Loans Receivable	'
	Note 3 - Loans Receivable
	Major classifications of loans receivable are summarized as follows:
			At September 30, 2013								At December 31, 2012
	($ in thousands)		# of Loans				Amount				# of Loans		Amount
	Loans Secured By Real Estate:
	Commercial loans			383				$  817,572				376		$   852,213
	Multifamily loans			139				210,508				142		208,699
	One to four family loans			19				68,662				13		41,676
	Land loans			4				5,881				7		7,167
				545				1,102,623				538		1,109,755
	All Other Loans:
	Business loans			19				1,130				18		949
	Consumer loans			14				347				12		359
				33				1,477				30		1,308
	Loans receivable, gross			578				1,104,100				568		1,111,063
	Deferred loan fees							(3,823)						(3,597)
	Loans receivable, net of deferred fees							1,100,277						1,107,466
	Allowance for loan losses							(26,777)						(28,103)
	Loans receivable, net							$1,073,500						$1,079,363
	At September 30, 2013 and December 31, 2012, there were $39.5 million and $45.9 million of loans, respectively, on nonaccrual status, and $11.4 million and $20.1 million of loans, respectively, classified as accruing TDRs. These loans represented all of our impaired loans as of those dates.
	At September 30, 2013, there were seven loans totaling $18.4 million, compared to two loans totaling $4.4 million at December 31, 2012, that were 90 days past due and still accruing interest. This category normally consists of loans that have matured and were in the process of being extended, and the borrowers were making monthly payments.
	The recorded investment, corresponding specific impairment valuation allowance and unpaid principal balance of our impaired loans at the dates indicated are summarized follows:
			-1																				-2		-3		# of
			Recorded Investment by State																				Specific		Total		Loans
																							Valuation		Unpaid
																							Allowance		Principal
	($ in thousands)		NY				FL				NJ		GA		CT		OH		SD		Total
	At September 30, 2013
	Commercial real estate:
	Retail		$	8,779			$	9,005			$	-	$	-	$	2,735	$	1,000	$	-	$	21,519		$1,661		$28,446		7
	Office Building			-				15,242				-		8,695		-		-		-		23,937		1,977		24,451		3
	Mixed Use			-				-				500		-		-		-		-		500		25		500		1
	Multifamily			-				3,140				-		-		-		-		-		3,140		596		3,140		2
	Land			-				-				-		-		-		-		1,802		1,802		498		1,802		1
	Totals		$	8,779			$	27,387			$	500	$	8,695	$	2,735	$	1,000	$	1,802	$	50,898		$4,757		$58,339		14
	At December 31, 2012
	Commercial Real Estate
	Retail		$	11,837			$	9,005			$	-	$	-	$	-	$	1,000	$	-	$	21,842		$1,966		$27,596		6
	Office Building			-				17,988				883		-		-		-		-		18,871		583		19,621		3
	Warehouse			950				-				-		-		-		-		-		950		28		950		1
	Mixed Use			8,632				-				500		-		-		-		-		9,132		1,248		9,421		4
	Multifamily			-				12,577				-		-		-		-		-		12,577		1,542		14,225		6
	Land			515				-				-		-		-		-		2,086		2,601		521		2,601		3
	Totals		$	21,934			$	39,570			$	1,383	$	-	$	-	$	1,000	$	2,086	$	65,973		$5,888		$74,414		23
	-1	Represents contractual unpaid principal less any partial principal chargeoffs and interest received and applied as a reduction of principal.
	-2	Represents a specific valuation allowance against the recorded investment included as part of the overall allowance for loan losses. All impaired loans at the dates indicated in the table had a specific valuation allowance.
	-3	Represents contractual unpaid principal balance (shown for informational purposes only). The borrowers are obligated to pay such amounts, however the ultimate collection by us of such amounts in this column cannot be assured.
	Other information related to our impaired loans is summarized as follows:
			Quarter Ended								Nine-Months Ended
			September 30,								September 30,
	($ in thousands)		2013				2012				2013		2012
	Average recorded investment in nonaccrual loans		$	39,159			$	49,788			$	41,039	$	53,809
	Total cash basis interest income recognized on nonaccrual loans			521				633				1,729		2,055
	Average recorded investment in accruing TDR loans			11,423				14,380				14,482		10,341
	Total interest income recognized on accruing TDR loans under modified terms			152				233				581		493
	Age analysis of our loan portfolio by segment at September 30, 2013 is summarized as follows:
	($ in thousands)		Total				Current				Past Due		Past Due		Past Due		Total		Total
			Portfolio								31-59		60-89		90 or more		Past Due		Classified
											Days		Days		Days				Nonaccrual
	Accruing Loans:
	Commercial real estate			$   780,338				$   758,670				$        -		$  3,265		$  18,403		$21,668		$          -
	Multifamily			208,225				208,225				-		-		-		-		-
	One to four family			68,662				68,662				-		-		-		-		-
Land			5,881				5,881				-		-		-		-		-
All other			1,477				1,477				-		-		-		-		-
Total accruing loans			1,064,583				1,042,915				-		3,265		18,403		21,668		-
Nonaccrual Loans (1):
Commercial real estate			37,234				36,720				-		-		514		514		37,234
Multifamily			2,283				2,283				-		-		-		-		2,283
Total nonaccrual loans			39,517				39,003				-		-		514		514		39,517
Total loans			$1,104,100				$1,081,918				$        -		$3,265		$18,917		$22,182		$39,517
Age analysis of our loan portfolio by segment at December 31, 2012 is summarized as follows:
($ in thousands)		Total				Current				Past Due		Past Due		Past Due		Total		Total
		Portfolio								31-59		60-89		90 or more		Past Due		Classified
										Days		Days		Days				Nonaccrual
Accruing Loans:
Commercial real estate			$   816,357				$   799,130				$12,836		$        -		$ 4,391		$17,227		$          -
Multifamily			198,942				198,942				-		-		-		-		-
One to four family			41,676				41,676				-		-		-		-		-
Land			6,882				4,221				2,661		-		-		2,661		-
All other			1,308				1,308				-		-		-		-		-
Total accruing loans			1,065,165				1,045,277				15,497		-		4,391		19,888		-
Nonaccrual Loans (1):
Commercial real estate			35,856				32,701				-		-		3,155		3,155		35,856
Multifamily			9,757				7,261				-		-		2,496		2,496		9,757
Land			285				285				-		-		-		-		285
Total nonaccrual loans			45,898				40,247				-		-		5,651		5,651		45,898
Total loans			$1,111,063				$1,085,524				$15,497		$        -		$10,042		$25,539		$45,898
-1	The amount of nonaccrual loans in the current column included $35.8 million of TDRs at September 30, 2013 and $36.3 million of TDRs at December 31, 2012 for which payments are being made in accordance with their restructured terms, but the loans were maintained on nonaccrual status in accordance with regulatory guidance. The remaining portion at both dates was comprised of certain paying loans classified nonaccrual due to concerns regarding the borrowers’ ability to continue making payments. Interest income from loan payments on all loans in nonaccrual status is recognized on a cash basis, provided the remaining principal balance is deemed collectible.
Information regarding the credit quality of the loan portfolio based on internally assigned grades follows:
($ in thousands)		Pass				Special Mention				Substandard (1)		Total
At September 30, 2013
Commercial real estate			$   743,233				$15,183				$59,156		$   817,572
Multifamily			204,994				2,374				3,140		210,508
One to four family			68,662				-				-		68,662
Land			4,079				-				1,802		5,881
All other			1,477				-				-		1,477
Total loans			$1,022,445				$17,557				$64,098		$1,104,100
Allocation of allowance for loan losses			$     20,626				$     410				$  5,741		$     26,777
At December 31, 2012
Commercial real estate			$   775,136				$17,041				$60,036		$   852,213
Multifamily			193,738				2,384				12,577		208,699
One to four family			41,676				-				-		41,676
Land			4,566				-				2,601		7,167
All other			1,308				-				-		1,308
Total loans			$1,016,424				$19,425				$75,214		$1,111,063
Allocation of allowance for loan losses			$     20,037				$     443				$  7,623		$     28,103
-1	Substandard loans consist of $39.5 million of nonaccrual loans, $6.0 million of accruing TDRs and $18.6 million of other performing loans at September 30, 2013, compared to $45.9 million of nonaccrual loans, $20.1 million of accruing TDRs and $9.2 million of other performing loans at December 31, 2012. At September 30, 2013, we also had one accruing TDR for $5.4 million which was rated pass.
The geographic distribution of the loan portfolio by state follows:
($ in thousands)		At September 30, 2013								At December 31, 2012
		Amount				% of Total				Amount		% of Total
New York			$   667,265				60.0%			$	717,141		64.5%
Florida			314,274				29.0				286,619		25.8
New Jersey			18,125				1.6				26,425		2.4
North Carolina			17,746				1.6				14,256		1.3
Pennsylvania			17,022				1.5				10,270		0.9
Georgia			16,246				1.5				11,752		1.1
Virginia			11,560				1.0				11,758		1.1
Kentucky			10,619				1.0				7,512		0.7
South Carolina			9,272				0.8				5,853		0.5
Connecticut			8,482				0.8				11,216		1.0
Tennessee			5,626				0.5				770		0.0
Ohio			2,236				0.2				2,260		0.2
South Dakota			1,802				0.2				2,086		0.2
All other states			3,825				0.3				3,145		0.3
			$1,104,100				100.0%			$	1,111,063		100.0%
Information regarding loans restructured during the nine-months ended September 30, 2013 follows:
		Number		Recorded Investment
($ in thousands)		of Loans		Pre-Modification				Post-Modification
Commercial real estate – interest rate reduced		2			$9,159				$9,159
Information regarding loans restructured during the nine-months ended September 30, 2012 is as follows:
		Number		Recorded Investment
		of Loans
($ in thousands)				Pre-Modification				Post-Modification
Land – extended maturity date		2			$520				$520
During the nine-months ended September 30, 2013, there was one TDR (which loan was modified within the previous 12 months) in the amount of $3.0 million that defaulted in March 2013. This loan subsequently was paid off in June 2013. During the nine-months ended September 30, 2013, one TDR in the amount of $1.9 million matured. This loan was re-financed by INB and transferred to a performing non-TDR category since the borrower was no longer experiencing financial difficulties. For the nine-months ended September 30, 2012, there were no TDRs that defaulted or TDRs transferred to a non-TDR loan category.
The distribution of TDRs by accruing versus non-accruing, by loan type and by geographic distribution follows:
($ in thousands)		At September 30, 2013				At December 31, 2012
Performing - nonaccrual status			$35,768				$36,291
Performing - accrual status			11,381				20,076
			$47,149				$56,367
Commercial real estate			$42,207				$43,685
Multifamily			3,140				10,081
Land			1,802				2,601
			$47,149				$56,367
New York			$  8,265				$18,478
Florida			27,387				33,920
New Jersey			-				883
Georgia			8,695				-
Ohio			1,000				1,000
South Dakota			1,802				2,086
			$47,149				$56,367

Allowance_for_Loan_Losses

Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Allowance for Loan Losses	'
	Note 4 - Allowance for Loan Losses
	Activity in the allowance for loan losses by loan type for the periods indicated is as follows:
	($ in thousands)		Commercial			Multifamily			One to Four		Land			All Other			Total
			Real Estate						Family
	Quarter Ended September 30, 2013
	Balance at beginning of period			$17,596			$5,098			$2,795		$   956			$10			$26,455
	Loan chargeoffs			-			-			-		-			-			-
	Loan recoveries (1)			67			5			-		-			-			72
	Provision (credit) for loan losses			(175	)		212			229		(15	)		(1	)		250
	Balance at end of period			$17,488			$5,315			$3,024		$   941			$  9			$26,777
	Quarter Ended September 30, 2012
	Balance at beginning of period			$18,343			$8,480			$   502		$1,509			$10			$28,844
	Loan chargeoffs			(548	)		-			-		-			-			(548)
	Loan recoveries			63			23			-		-			-			86
	Provision (credit) for loan losses			468			(381	)		250		(337	)		-			-
	Balance at end of period			$18,326			$8,122			$ 752		$1,172			$10			$28,382
	Activity in the allowance for loan losses by loan type for the periods indicated is as follows:
	($ in thousands)		Commercial			Multifamily			One to Four		Land			All Other			Total
			Real Estate						Family
	Nine-Months Ended September 30, 2013
	Balance at beginning of period			$19,051			$6,881			$1,120		$1,043			$  8			$28,103
	Loan chargeoffs			(1,932	)		(6	)		-		-			-			(1,938)
	Loan recoveries (1)			947			682			-		483			-			2,112
	Provision (credit) for loan losses			(578	)		(2,242	)		1,904		(585	)		1			(1,500)
	Balance at end of period			$17,488			$5,315			$3,024		$   941			$  9			$26,777
	Nine-Months Ended September 30, 2012
	Balance at beginning of period			$19,156			$8,848			$332		$2,069			$10			$30,415
	Loan chargeoffs			(2,215	)		(261	)		-		-			-			(2,476)
	Loan recoveries			383			60			-		-			-			443
	Provision for loan losses			1,002			(525	)		420		(897	)		-			-
	Balance at end of period			$18,326			$8,122			$752		$1,172			$10			$28,382
	-1	See note 14 to financial statements in this report for a discussion on recoveries.
	The following tables set forth the balances of our loans receivable by segment and impairment evaluation and the allowance for loan losses associated with such loans at the dates indicated.
	($ in thousands)		Commercial			Multifamily			One to Four		Land			All Other			Total
			Real Estate						Family
	At September 30, 2013
	Loans:
	Individually evaluated for impairment			$  45,955			$    3,141			$           -		$1,802			$         -			$     50,898
	Collectively evaluated for impairment			771,617			207,367			68,662		4,079			1,477			1,053,202
	Total loans			$817,572			$210,508			$68,662		$5,881			$1,477			$1,104,100
	Allowance for loan losses:
	Individually evaluated for impairment (1)			$    3,663			$       596			$           -		$   498			$        -			$       4,757
	Collectively evaluated for impairment			13,825			4,719			3,024		443			9			22,020
	Total allowance for loan losses			$  17,488			$   5,315			$3,024		$   941			$        9			$     26,777
	At December 31, 2012
	Loans:
	Individually evaluated for impairment			$  50,795			$  12,577			$           -		$2,601			$          -			$     65,973
	Collectively evaluated for impairment			801,418			196,122			41,676		4,566			1,308			1,045,090
	Total loans			$852,213			$208,699			$41,676		$7,167			$1,308			$1,111,063
	Allowance for loan losses:
	Individually evaluated for impairment (1)			$    3,825			$    1,542			$           -		$   521			$        -			$       5,888
	Collectively evaluated for impairment			15,226			5,339			1,120		522			8			22,215
	Total allowance for loan losses			$  19,051			$    6,881			$  1,120		$1,043			$       8			$     28,103
	(1) See note 3 to financial statements in this report.

Foreclosed_Real_Estate_and_Val

Foreclosed Real Estate and Valuation Allowance for Real Estate Losses	9 Months Ended
	Sep. 30, 2013
Banking And Thrift [Abstract]	'
Foreclosed Real Estate and Valuation Allowance for Real Estate Losses	'
	Note 5 - Foreclosed Real Estate and Valuation Allowance for Real Estate Losses
	Real estate acquired through foreclosure by property type is summarized as follows:
		At September 30, 2013						At December 31, 2012
	($ in thousands)	# of Properties			Amount (1)			# of Properties			Amount (1)
	Commercial real estate		3			$  5,334			2			$2,790
	Multifamily		1			6,685			3			12,000
	Land		-			-			1			1,133
	Real estate acquired through foreclosure		4			$12,019			6			$15,923
	(1) Reported net of any associated valuation allowance.
	Activity in the valuation allowance for real estate losses is summarized as follows:
		Quarter Ended						Nine-Months Ended
		September 30,						September 30,
	($ in thousands)	2013			2012			2013			2012
	Valuation allowance at beginning of period		$6,044			$7,945			$5,339			$6,037
	Provision for real estate losses		250			1,025			955			2,933
	Real estate chargeoffs		(4,171	)		(3,642	)		(4,171	)		(3,642)
	Valuation allowance at end of period		$2,123			$5,328			$2,123			$5,328

Deposits

Deposits	9 Months Ended
	Sep. 30, 2013
Banking And Thrift [Abstract]	'
Deposits	'
	Note 6 - Deposits
	Scheduled maturities of certificates of deposit accounts (CDs) are as follows:
		At September 30, 2013			At December 31, 2012
	($ in thousands)	Amount		Wtd-Avg	Amount		Wtd-Avg
				Stated Rate			Stated Rate
	Within one year		$434,055	2.91%		$519,236	2.92%
	Over one to two years		175,921	2.02		181,698	2.79
	Over two to three years		108,008	2.25		89,049	2.74
	Over three to four years		105,813	2.60		60,119	3.02
	Over four years		73,615	2.02		86,776	2.93
			$897,412	2.54%		$936,878	2.89%
	CDs of $100,000 or more totaled $467 million at September 30, 2013 and $463 million at December 31, 2012 and included brokered CDs of $85 million and $78 million, respectively.
	At September 30, 2013, all CDs of $100,000 or more (inclusive of brokered CDs) by remaining maturity were as follows: $220 million due within one year; $77 million due over one to two years; $60 million due over two to three years; $64 million due over three to four years; and $46 million due thereafter. At September 30, 2013, brokered CDs had a weighted average rate of 3.48% and their remaining maturities were as follows: $32 million due within one year; $5 million due over one to two years; $8 million due over two to three years; $24 million due over three to four years and $16 million due over four years.

Lines_of_Credit

Lines of Credit	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Lines of Credit	'
	Note 7 - Lines of Credit
	At September 30, 2013, INB had $24 million of unsecured credit lines that were cancelable by the lender at any time. As a member of the Federal Home Loan Bank of New York (FHLB) and the Federal Reserve Bank of New York (FRB), INB can borrow from these institutions on a secured basis. At September 30, 2013, INB had available collateral consisting of investment securities and certain loans that could be pledged to support additional total borrowings of approximately $441 million from the FHLB and FRB, if needed. There were no borrowings during 2013.
	The following is a summary of certain information regarding FHLB advances in the aggregate.
		At or For the Quarter Ended				At or For the Nine-Months Ended
		September 30,				September 30,
	($ in thousands)	2013		2012		2013		2012
	Balance at period end		-		$  7,000		-		$  7,000
	Maximum amount outstanding at any month end for the period		-		$10,500		-		$13,500
	Average outstanding balance for the period		-		$  9,511		-		$11,215
	Weighted-average interest rate paid for the period		-		4.31%		-		4.26%
	Weighted-average interest rate at period end		-		4.22%		-		4.22%

Subordinated_Debentures_Capita

Subordinated Debentures - Capital Securities	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Subordinated Debentures - Capital Securities	'
	Note 8 - Subordinated Debentures - Capital Securities
	Capital Securities (commonly referred to as trust preferred securities) outstanding are summarized as follows:
			At September 30, 2013					At December 31, 2012
	($ in thousands)		Principal		Accrued		Interest	Principal		Accrued		Interest
					Interest		Rate			Interest		Rate
					Payable					Payable
	Capital Securities II - debentures due September 17, 2033			$15,464		$147	3.20%		$15,464		$1,661	3.26%
	Capital Securities III - debentures due March 17, 2034			15,464		139	3.04%		15,464		1,577	3.10%
	Capital Securities IV - debentures due September 20, 2034			15,464		119	2.65%		15,464		1,370	2.71%
	Capital Securities V - debentures due December 15, 2036			10,310		58	1.90%		10,310		1,620	1.96%
				$56,702		$463			$56,702		$6,228
	The securities are obligations of IBC’s wholly owned statutory business trusts, Intervest Statutory Trust II, III, IV and V, respectively. Each Trust was formed with a capital contribution from IBC and for the sole purpose of issuing and administering the Capital Securities. The proceeds from the issuance of the Capital Securities together with the capital contribution for each Trust were used to acquire IBC’s Junior Subordinated Debentures (the “Debentures”) that are due concurrently with the Capital Securities. The Capital Securities, net of IBC’s capital contributions of $1.7 million, total $55 million and qualify as regulatory Tier 1 capital up to certain limits. IBC has guaranteed the payment of distributions on, payments on any redemptions of, and any liquidation distribution with respect to the Capital Securities. Issuance costs associated with Capital Securities II, III and IV were capitalized and are being amortized over the contractual life of the securities using the straight-line method. The unamortized balance totaled approximately $0.7 million at September 30, 2013. There were no issuance costs for Capital Securities V.
	Interest payments on the Debentures (and the corresponding distributions on the Capital Securities) are payable in arrears as follows:
		—		Capital Securities II - quarterly at the rate of 2.95% over 3 month libor;
		—		Capital Securities III - quarterly at the rate of 2.79% over 3 month libor;
		—		Capital Securities IV- quarterly at the rate of 2.40% over 3 month libor; and
		—		Capital Securities V - quarterly at the rate of 1.65% over 3 month libor.
	Interest payments may be deferred at any time and from time to time during the term of the Debentures at IBC’s election for up to 20 consecutive quarterly periods, or 5 years, with no limitations on the number of deferral periods IBC may elect, provided, however, no deferral period may extend beyond the maturity date of the Debentures. During an interest deferral period, interest will continue to accrue on the Debentures and interest on such accrued interest will accrue at an annual rate equal to the interest rate in effect for such deferral period, compounded quarterly from the date such interest would have been payable were it not deferred. At the end of the deferral period, IBC will be obligated to pay all interest then accrued and unpaid. During the deferral period, among other restrictions, IBC and any affiliate cannot, subject to certain exceptions: (i) declare or pay any dividends or distributions on, or redeem, purchase or acquire any capital stock of IBC or its affiliates (other than payment of dividends to IBC); or (ii) make any payment of principal or interest or premium on, or repay, repurchase or redeem any debt securities of IBC or its affiliates that rank pari passu with or junior to the Debentures. In February 2010, as required by its primary regulator, IBC exercised its right to defer interest payments as described above. In June 2013, IBC, with approval from its regulator, repaid all accrued interest payments in arrears as of that date on the Debentures. In September 2013, IBC again exercised its right to defer interest payments on the Debentures due to the restrictions of its written agreement with its regulator.
	The Capital Securities are subject to mandatory redemption as follows: (i) in whole, but not in part, upon repayment of the Debentures at stated maturity or earlier, at the option of IBC, within 90 days following the occurrence and continuation of certain changes in the tax or capital treatment of the Capital Securities, or a change in law such that the statutory trust would be considered an investment company, contemporaneously with the redemption by IBC of the Debentures; and (ii) in whole or in part at any time contemporaneously with the optional redemption by IBC of the Debentures in whole or in part. Any redemption would be subject to the receipt of regulatory approvals.

Stockholders_Equity_and_Redemp

Stockholders' Equity and Redemption of Preferred Stock	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Stockholders' Equity and Redemption of Preferred Stock	'
	Note 9 - Stockholders’ Equity and Redemption of Preferred Stock
	IBC is authorized to issue up to 62.3 million shares of its capital stock, consisting of 62 million shares of common stock and 300,000 shares of preferred stock. IBC’s board of directors determines the powers, preferences and rights, and the qualifications, limitations, and restrictions thereof on any series of preferred stock issued.
	From December 23, 2008 through June 24, 2013 a total of 25,000 shares of preferred stock were designated as Series A (the “Preferred Stock”) and were owned by the U.S. Department of the Treasury (the “Treasury”). The Preferred Stock was issued to the Treasury by IBC in connection with IBC’s participation in the Capital Purchase Program (the “CPP”) under the Treasury’s Troubled Asset Relief Program (“TARP”), together with a ten-year warrant (the “Warrant”) to purchase 691,882 shares of IBC’s common stock at an exercise price of $5.42 per share. As described in greater detail in note 10 to the financial statements in our 2012 10-K, in February 2010, IBC ceased the declaration and payment of dividends on the Preferred Stock as required by IBC’s primary regulator.
	On June 6, 2013, the Treasury announced its intent to sell its investment in IBC’s Preferred Stock, along with similar investments the Treasury had made in five other financial institutions, primarily to qualified institutional buyers and certain institutional accredited investors. IBC sought and obtained regulatory approvals allowing it to participate in the auction. Using a modified Dutch auction methodology that established a market price by allowing investors to submit bids at specified increments during the period from June 10 through June 13, 2013, the Treasury auctioned all of IBC’s 25,000 shares of Preferred Stock. IBC was the winning bidder on 6,250 shares of the Preferred Stock and the remaining 18,750 shares were purchased by unrelated third parties. The closing price of the auctioned shares was $970.00 per share. On June 24, 2013, IBC completed the repurchase of 6,250 shares of the Preferred Stock from the Treasury and those shares were retired. The shares were repurchased for $6.1 million, plus an additional $1.2 million in accrued and unpaid dividends through June 24, 2013, for a total of $7.3 million.
	On August 15, 2013, IBC redeemed the remaining 18,750 shares of the Preferred Stock held by the unrelated third parties for a purchase price equaling the stated liquidation value of $1,000 per share, plus accumulated and unpaid dividends earned through August 15, 2013. The total cost of redeeming these shares was $22.6 million, which included $3.9 million of preferred dividends. IBC received all necessary regulatory approvals to complete the redemption. The Treasury continues to hold the Warrant as of September 30, 2013.

Common_Stock_Warrant_Options_a

Common Stock Warrant, Options and Restricted Common Stock	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Common Stock Warrant, Options and Restricted Common Stock	'
	Note 10 - Common Stock Warrant, Options and Restricted Common Stock
	IBC has shareholder-approved plans, the 2006 Long Term Incentive Plan and the 2013 Equity Incentive Plan (together referred to as the “Plans”) under which stock options, restricted stock and other forms of incentive compensation may be awarded from time to time to officers, employees and directors of IBC and its subsidiaries. The maximum number of shares of common stock that may be awarded under the Plans is 2,250,000. At September 30, 2013, 777,993 shares of common stock were available for award under the Plans. There were no awards of stock options in the first nine months of 2013 or 2012.
	A summary of activity in outstanding common stock options and related information follows:
			Exercise Price Per Warrant/Option																			Wtd-Avg.
																						Exercise
			$5.42 (1)			$17.10			$7.50			$4.02			$3.00			$2.55		Total		Price
	($ in thousands, except per share amounts)
	Outstanding at December 31, 2012			691,882			116,640			120,190			68,910			38,200			42,300		1,078,122		$6.63
	Forfeited/expired (2)			-			(1,200	)		(1,200	)		(1,100	)		(1,900	)		(3,300)		(8,700)		$5.52
	Options exercised			-			-			-			(9,600	)		(3,200	)		(2,167)		(14,967)		$3.59
	Outstanding at September 30, 2013			691,882			115,440			118,990			58,210			33,100			36,833		1,054,455		$6.68
	Expiration date			12/23/18			12/13/17			12/11/18			12/10/19			12/9/20			12/08/21
	Vested and exercisable (3)			100%			100%			100%			100%			67%			33%		96%
	Wtd-avg contractual remaining term (in years)			5.2			4.2			5.2			6.2			7.2			8.2		5.4
	Intrinsic value at September 30, 2013 (4)			$1,737			-			$51			$228			$163			$198		$2,377
	-1	This is the warrant held by the U.S. Treasury as described in note 9 to the financial statements in this report.
	-2	Represent options forfeited or expired unexercised.
	-3	The $3.00 options further vest and become 100% exercisable on December 9, 2013. The $2.55 options further vest and become exercisable at the rate of 33.33% on December 8, 2013 and 2014. Full vesting may occur earlier upon the occurrence of certain events as defined in the option agreement.
	-4	Intrinsic value was calculated using the closing price of IBC’s common stock on September 30, 2013 of $7.93.
	A summary of selected information regarding restricted common stock awards made under the Plans during the nine months ended September 30, 2013 and 2012 follows:
	($ in thousands, except per share amounts)		Stock Grant			Stock Grant
	Grant date of award			1/24/13			1/19/12
	Total restricted shares of stock awarded (1)			330,700			465,400
	Estimated fair value per share awarded (2)			$4.50			$2.90
	Total estimated fair value of award			$1,488			$1,350
	Awards scheduled to vest as follows:
	Jan-13			-			256,800
	Jan-14			49,566			133,455
	Jan-15			170,888			75,145
	Jan-16			110,246			-
				330,700			465,400
	-1	For the 2012 period, awards were as follows: a total of 175,000 shares to five executive officers (vesting in two installments, with two thirds vesting on the second anniversary of the grant and the remaining one third on the third anniversary of the grant); a total of 240,000 shares to six non-employee directors (vesting 100% on the first anniversary of the grant); and a total of 50,400 shares to other officers and employees (vesting in three equal installments, with one third on each of the next three anniversary dates of the grant).
	For the 2013 period, awards were as follows: a total of 182,000 shares to five executive officers (vesting in two installments, with two thirds vesting on the second anniversary of the grant and the remaining one third on the third anniversary of the grant); a total of 80,000 shares to eight non-employee directors and 68,700 shares to other officers and employees (vesting in three equal installments, with one third on each of the next three anniversary dates of the grant).
	-2	Fair value of each award was estimated as of the grant date based on the closing market price of the common stock on the grant date.
	A summary of activity in outstanding restricted common stock and related information follows:
			Price Per Share
			$2.35			$2.90			$4.50			Total
	Outstanding at December 31, 2012			317,500			464,800			-			782,300
	Shares vested and no longer restricted			-			(256,600	)		-			(256,600)
	Shares granted			-			-			330,700			330,700
	Shares forfeited			(7,100	)		(6,133	)		(5,400)			(18,633)
	Outstanding at September 30, 2013 (1) (2)			310,400			202,067			325,300			837,767
	Notes to the preceding table follow:
	-1	All outstanding shares of restricted common stock were unvested at September 30, 2013 and subject to forfeiture. Shares issued at a price of $2.35 on December 9, 2010 will vest 100% on December 9, 2013. Shares issued at a price of $2.90 on January 19, 2012 will vest as follows: 130,200 on January 19, 2014 and 71,867 on January 19, 2015. Shares issued at a price of $4.50 on January 24, 2013 will vest as follows: 47,767 on January 24, 2014, 169,100 on January 24, 2015 and 108,433 on January 24, 2016.
	-2	Vesting is subject to the grantee’s continued employment with us or, in the case of non-employee directors, the grantee’s continued service as our director on the vesting dates. All of the awards are subject to accelerated vesting upon the death or disability of the grantee or upon a change in control of IBC, as defined in the restricted stock agreements. The record holder of IBC’s restricted shares of common stock possesses all the rights of a holder of our common stock, including the right to receive dividends on and to vote the restricted shares. The restricted shares may not be sold, transferred, pledged, assigned, encumbered, or otherwise alienated or hypothecated until they become fully vested and transferable in accordance with the agreements. Prior to June 24, 2013, shares held by certain of our executive officers had further restrictions on transferability due to IBC’s participation in the TARP program.
	Stock-based compensation expense is recognized on a straight-line basis and is recorded in “Salaries and Employee Benefits” with a corresponding increase to stockholders’ equity as paid in capital over the vesting period of each award and is as follows: for the quarter ended September 30, 2013 and 2012, $231,000 and $309,000, respectively, and for the nine-months ended September 30, 2013 and 2012, $731,000 and $885,000, respectively. At September 30, 2013, pre-tax compensation expense related to all nonvested awards of options and restricted stock not yet recognized totaled $1.5 million and such amount is expected to be recognized in the future over a weighted average period of approximately 2.0 years.
	Our income taxes payable in the first nine months of 2013 was reduced by the excess income tax benefit associated with the vesting of restricted common stock awards and the exercise of stock option awards (calculated as the difference between the fair market value of the stock at the vesting date versus the grant date in the case of stock awards and the difference between the fair market value of the stock at the exercise date versus the exercise price per share in the case of options, multiplied by our effective income tax rate). The net tax benefit amounted to $150,000 and is required to be recorded as an increase to our paid-in capital. There was no such tax benefit for the same 2012 period.

Deferred_Tax_Asset

Deferred Tax Asset	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Deferred Tax Asset	'
	Note 11 - Deferred Tax Asset
	At September 30, 2013 and December 31, 2012, we had a deferred tax asset totaling $21.8 million and $29.2 million, respectively. The tax asset relates to the unrealized benefit for net temporary differences between the financial statement carrying amounts of our existing assets and liabilities and their respective tax bases that will result in future income tax deductions as well as an unused net operating loss carryforward (NOL) and Federal AMT credit carryforward, all of which can be applied against and reduce our future taxable income and tax liabilities.
	At September 30, 2013, the gross NOL amounted to approximately $2 million for Federal purposes and $34 million for state and local purposes and the Federal AMT credit carryforward amounted to $1.8 million. The NOL carryforwards expire in 2030. The AMT credit carryforward has no expiration date. We have determined that a valuation allowance for our deferred tax asset was not required at any time during the reporting periods in this report because we believe that it is more likely than not that our deferred tax asset will be fully realized. This conclusion is based on prior taxable earning history as well as our ability to generate sufficient future taxable earnings to recognize our deferred tax asset, as discussed in this report and in note 14 to the financial statements in our 2012 10-K.

Earnings_Per_Common_Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings Per Common Share	'
	Note 12 - Earnings Per Common Share
	Net earnings applicable to common stockholders and the weighted-average number of shares used for basic and diluted earnings per common share computations are summarized in the table that follows:
			Quarter Ended				Nine-Months Ended
			September 30,				September 30,
			2013		2012		2013		2012
	Basic Earnings Per Common Share:
	Net earnings available to common stockholders			$2,588,000		$2,225,000		$9,230,000		$7,347,000
	Weighted-Average number of common shares outstanding			21,915,596		21,589,744		21,891,886		21,558,092
	Basic Earnings Per Common Share			$0.12		$0.10		$0.42		$0.34
	Diluted Earnings Per Common Share:
	Net earnings available to common stockholders			$2,588,000		$2,225,000		$9,230,000		$7,347,000
	Weighted-Average number of common shares outstanding:
	Common shares outstanding			21,915,596		21,589,744		21,891,886		21,558,092
	Potential dilutive shares resulting from exercise of warrants /options (1)			135,866		978		81,064		276
	Total average number of common shares outstanding used for dilution			22,051,462		21,590,722		21,972,950		21,558,368
	Diluted Earnings Per Common Share			$0.12		$0.10		$0.42		$0.34
	-1	All outstanding options/warrants to purchase shares of our common stock were considered for the Diluted EPS computations and only those that were dilutive (as determined by using the treasury stock method prescribed by GAAP) were included in the diluted earnings per share computations above. For both the quarter and nine-month periods of 2013 and 2012 calculations, 234,430 and 1,041,122, respectively, of options/warrants to purchase shares of common stock were not dilutive because the exercise price per share of each option/warrant was above the average market price of our common stock during these periods.

OffBalance_Sheet_Financial_Ins

Off-Balance Sheet Financial Instruments	9 Months Ended
	Sep. 30, 2013
Investments All Other Investments [Abstract]	'
Off-Balance Sheet Financial Instruments	'
	Note 13 - Off-Balance Sheet Financial Instruments
	INB is party to financial instruments with off-balance sheet risk in the normal course of its business to meet the financing needs of its customers. These instruments can be in the form of commitments to extend credit, unused lines of credit and standby letters of credit, and may involve, to varying degrees, elements of credit and interest rate risk in excess of the amounts recognized in our financial statements. Our maximum exposure to credit risk is represented by the contractual amount of those instruments. Commitments to extend credit are agreements to lend funds to a customer as long as there is no violation of any condition established in the contract. Such commitments generally have fixed expiration dates or other termination clauses and normally require payment of fees to INB. Since some of the commitments are expected to expire without being drawn upon, the total commitment amount does not necessarily represent future cash requirements. We evaluate each customer’s creditworthiness on a case-by-case basis. Standby letters of credit are conditional commitments issued by INB to guarantee the performance of its customer to a third party. The credit risk involved in the underwriting of letters of credit is essentially the same as that involved in originating loans. INB had no standby letters of credit outstanding at September 30, 2013 or December 31, 2012.
	The contractual amounts of off-balance sheet financial instruments are as follows:
	($ in thousands)	At September 30, 2013		At December 31, 2012
	Commitments to extend credit		$30,672		$19,154
	Unused lines of credit		677		854
			$31,349		$20,008

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Contingencies	'
	Note 14 - Contingencies
	We are periodically a party to or otherwise involved in legal proceedings arising in the normal course of business, such as foreclosure proceedings. Based on review and consultation with our legal counsel, we do not believe that there is any pending or threatened proceeding against us, which, if determined adversely, would have a material effect on our business, results of operations, financial position or liquidity.
	In the first and second quarters of 2013, INB entered into settlement agreements with respect to certain litigation INB had pursued in connection with foreclosure actions it had commenced in 2010 on several of its loans. INB commenced the actions to collect, in one case, insurance proceeds, which it contended had been improperly paid to various third parties, and in another case, damages due to alleged legal malpractice when the loan was originated. As a result of these settlements, INB received net proceeds totaling $2.7 million and $0.1 million in the first and second quarter of 2013, respectively, which was recorded as $1.1 million of recoveries of prior loan charge offs and $1.6 million of recoveries of prior real estate expenses associated with two loans and underlying collateral property.

Regulatory_Matters_and_Regulat

Regulatory Matters and Regulatory Capital	9 Months Ended
	Sep. 30, 2013
Banking And Thrift [Abstract]	'
Regulatory Matters and Regulatory Capital	'
	Note 15 - Regulatory Matters and Regulatory Capital
	Since January 2011, IBC has been operating under a written agreement with its primary regulator, the Federal Reserve Bank of New York (the “FRB”). From December 2010 through March 20, 2013, INB was also operating under a formal agreement with its primary regulator, the Office of the Comptroller of the Currency (the “OCC”). Both of these agreements, including various restrictions arising therefrom, have affected our business. For a discussion of the agreements and related restrictions, see note 19 to the financial statements in our 2012 10-K.
	On March 21, 2013, INB received notification from the OCC that actions taken by INB since December 2010 satisfied the OCC’s regulatory directives and the Formal Agreement dated December 9, 2010 between INB and the OCC was terminated. As a result, INB is no longer subject to any regulatory agreement or to the related restrictions described in our 2012 10-K. Additionally, effective March 21, 2013, the OCC terminated its heightened regulatory capital requirements that had been imposed on INB since February 2010. As of the filing date of this report, IBC remained subject to its written agreement with the FRB and the restrictions contained therein. IBC has been informed by the FRB that it is reviewing the need for such agreement and IBC has advised the FRB that in IBC’s view it has complied with all of the requirements of the written agreement.
	At September 30, 2013 and December 31, 2012, we believe that IBC and INB met all regulatory capital adequacy requirements to which they were subject. As of the date of filing of this report, we are not aware of any conditions or events that would have changed the status of such compliance with those requirements at September 30, 2013.
	Information regarding our regulatory capital and related ratios is summarized as follows:
			INB				IBC Consolidated
			At September 30,		At December 31,		At September 30,		At December 31,
	($ in thousands)		2013		2012		2013		2012
	Tier 1 capital (1)			$234,166		$244,081		$238,955		$249,465
	Tier 2 capital			15,377		15,566		15,416		15,620
	Total risk-based capital			$249,543		$259,647		$254,371		$265,085
	Net risk-weighted assets for regulatory purposes			$1,218,718		$1,232,670		$1,221,807		$1,238,024
	Average assets for regulatory purposes			$1,563,834		$1,690,329		$1,568,881		$1,696,410
	Total capital to risk-weighted assets			20.48%		21.06%		20.82%		21.41%
	Tier 1 capital to risk-weighted assets			19.21%		19.80%		19.56%		20.15%
	Tier 1 capital to average assets			14.97%		14.44%		15.23%		14.71%
	-1	IBC’s consolidated Tier 1 capital for both dates included $55 million of IBC’s outstanding qualifying trust preferred securities, which are discussed in further detail in note 8 to the financial statements in this report .
	The table that follows presents information regarding our actual capital and minimum capital requirements.
			Actual Capital				Minimum				Minimum				Minimum
							Under Prompt				To Be “Well Capitalized”				Under Agreement
							Corrective				Under Prompt Corrective				With OCC
							Action Provisions				Action Provisions
	($ in thousands)		Amount		Ratio		Amount		Ratio		Amount		Ratio		Amount		Ratio
	IBC Consolidated at September 30, 2013:
	Total capital to risk-weighted assets (1)			$254,371		20.82%		$97,745		8.00%		NA		NA		NA		NA
	Tier 1 capital to risk-weighted assets (1)			$238,955		19.56%		$48,872		4.00%		NA		NA		NA		NA
	Tier 1 capital to average assets (1)			$238,955		15.23%		$62,755		4.00%		NA		NA		NA		NA
	IBC Consolidated at December 31, 2012:
	Total capital to risk-weighted assets			$265,085		21.41%		$99,042		8.00%		NA		NA		NA		NA
	Tier 1 capital to risk-weighted assets			$249,465		20.15%		$49,521		4.00%		NA		NA		NA		NA
	Tier 1 capital to average assets			$249,465		14.71%		$67,856		4.00%		NA		NA		NA		NA
	INB at September 30, 2013:
	Total capital to risk-weighted assets			$249,543		20.48%		$97,497		8.00%		$121,872		10.00%		NA		NA
	Tier 1 capital to risk-weighted assets			$234,166		19.21%		$48,749		4.00%		$  73,123		6.00%		NA		NA
	Tier 1 capital to average assets			$234,166		14.97%		$62,553		4.00%		$  78,192		5.00%		NA		NA
	INB at December 31, 2012:
	Total capital to risk-weighted assets			$259,647		21.06%		$98,614		8.00%		$123,267		10.00%		$147,920		12.00%
	Tier 1 capital to risk-weighted assets			$244,081		19.80%		$49,307		4.00%		$  73,960		6.00%		$123,267		10.00%
	Tier 1 capital to average assets			$244,081		14.44%		$67,613		4.00%		$  84,516		5.00%		$152,130		9.00%
	-1	Assuming IBC had excluded all of its eligible outstanding trust preferred securities (which totaled $55 million) from its Tier 1 capital and included the entire amount in its Tier 2 capital, consolidated proforma capital ratios at September 30, 2013 would have been 20.82%, 15.06% and 11.73%, respectively.
	The table that follows presents additional information regarding our capital adequacy at September 30, 2013.
			INB Regulatory Capital						Consolidated Regulatory Capital
	($ in thousands)		Actual		Required (1)		Excess		Actual		Required		Excess
	Total capital to risk-weighted assets			$249,543		$121,872		$127,671		$254,371		$97,745		$156,626
	Tier 1 capital to risk-weighted assets			$234,166		$  73,123		$161,043		$238,955		$48,872		$190,083
	Tier 1 capital to average assets			$234,166		$  78,192		$155,974		$238,955		$62,755		$176,200
	(1) Minimum amount required to be considered “Well-Capitalized.”

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Note 16 - Fair Value Measurements
	We use fair value measurements to record fair value adjustments to certain of our assets and liabilities and to determine our fair value disclosures. In accordance with GAAP, we group our assets and liabilities at fair value into three levels (Level 1, 2 and 3), based on the markets in which they are traded and the reliability of the assumptions that are used to determine their fair value. Level 1 has the highest level of reliability because fair value is based on actively traded markets. See our 2012 10-K, note 20 to the financial statements, for a further discussion of all the valuation levels.
	At September 30, 2013 and December 31, 2012, we only had approximately $1.0 million of assets (comprised of securities available for sale using Level 1 inputs) and no liabilities that were recorded at fair value on a recurring basis.
	From time to time, we may be required to record at fair value other assets on a non-recurring basis, such as our impaired loans, impaired investment securities and real estate we own through foreclosure. These non-recurring fair value adjustments involve the application of lower-of-cost-or-market accounting or writedowns of individual assets. All of our assets measured at fair value on a nonrecurring basis use Level 3 inputs. We have no liabilities that are recorded at fair value on a nonrecurring basis.
	For Level 3, fair value estimates are generally generated from model-based techniques that use significant assumptions that are not observable in the marketplace. These assumptions reflect our estimates of assumptions that market participants would use in pricing the asset or liability. Valuation techniques for Level 3 include the use of discounted cash flow models. The fair value results obtained from Level 3 valuation techniques cannot be determined with precision and may not be realized in an actual sale or immediate settlement of the asset or liability.
	The following tables provide information regarding our assets measured at fair value on a nonrecurring basis.
					Outstanding Carrying Value
			At September 30, 2013						At December 31, 2012
	($ in thousands)				Level 3				Level 3
	Impaired loans (1):
	Commercial real estate					$45,956				$50,795
	Multifamily					3,140				12,577
	Land					1,802				2,601
	Total impaired loans					50,898				65,973
	Impaired securities (2)					2,604				3,721
	Real estate acquired through foreclosure					12,019				15,923
			Accumulated Losses on								Total Losses (Gains) (3)
			Outstanding Balance as of:								Quarter Ended						Nine-Months Ended
			September 30,				December 31,				September 30,						September 30,
	($ in thousands)		2013				2012				2013			2012			2013			2012
	Impaired loans:
	Commercial real estate			$10,294				$  9,979				$    -			$  (254	)		$  823			$  (241)
	Multifamily			598				3,092				(7	)		(170	)		(964	)		(100)
	Land			500				521				(2	)		-			(23	)		(493)
	Total impaired loans			11,392				13,592				(9	)		(424	)		(164	)		(834)
	Impaired securities			5,197				4,233				273			-			964			157
	Foreclosed real estate			2,123				5,339				149			1,025			135			2,933
	Totals			$18,712				$23,164				$413			$     601			$935			$2,256
	-1	Comprised of all nonaccrual loans and accruing TDRs. Outstanding carrying value excludes a specific valuation allowance included in the overall allowance for loan losses. See note 4 to the financial statements in this report.
	-2	Comprised of certain held-to maturity investments in trust preferred securities considered other than temporarily impaired. See note 2 to the financial statements in this report.
	-3	Represents total losses or (gains) recognized on all assets measured at fair value on a nonrecurring basis during the period indicated. The losses or (gains) for impaired loans represent the change (before net chargeoffs) during the period in the corresponding specific valuation allowance, while the losses (gains) for foreclosed real estate represent writedowns in carrying values subsequent to foreclosure (recorded as provisions for real estate losses) adjusted for any recoveries of prior writedowns and gains or losses from the transfer/sale of the properties during the period. The losses on investment securities represent other than temporary impairment “OTTI” writedowns recorded as a component of noninterest income (as described in note 2 to the financial statements in this report).
	The following table presents information regarding the change in assets measured at fair value on a nonrecurring basis for the periods indicated
	($ in thousands)		Impaired				Impaired				Foreclosed
			Securities				Loans				Real Estate
	Quarter Ended September 30, 2013
	Balance at beginning of period			$2,923				$50,533				$14,869
	Net new impaired loans			-				514				-
	Other than temporary impairment write downs			(273	)			-				-
	Principal repayments/sales			(46	)			(149	)			-2,701
	Writedowns of carrying value subsequent to foreclosure			-				-				-250
	Gains from sales			-				-				101
	Balance at end of period			$2,604				$50,898				$12,019
	Nine-Months Ended September 30, 2013
	Balance at beginning of period			$3,721				$65,973				$15,923
	Net new impaired loans			-				8,761				-
	Impaired loans transferred to foreclosed real estate			-				(3,040	)			3,040
	Other than temporary impairment write downs			(964	)			-				-
	Principal repayments/sales			(153	)			(18,858	)			-6,809
	Chargeoffs of impaired loans			-				(1,938	)			-
	Writedowns of carrying value subsequent to foreclosure			-				-				-1,029
	Recoveries of prior writedowns			-				-				74
	Gains from sales			-				-				820
	Balance at end of period			$2,604				$50,898				$12,019
	The following table presents information regarding the change in assets measured at fair value on a nonrecurring basis for the periods indicated.
	($ in thousands)		Impaired				Impaired				Foreclosed
			Securities				Loans				Real Estate
	Quarter Ended September 30, 2012
	Balance at beginning of period			$4,221				$65,240				$26,370
	Net new impaired loans			-				872				-
	Impaired loans transferred to foreclosed real estate			-				(1,457	)			1,457
	Principal repayments/sales			-				(1,983	)			(4,944)
	Chargeoffs of impaired loans			-				(548	)			-
	Writedowns of carrying value subsequent to foreclosure			-				-				(1,025)
Balance at end of period			$4,221				$62,124				$21,858
Nine-Months Ended September 30, 2012
Balance at beginning of period			$4,378				$66,269				$28,278
Net new impaired loans			-				8,254				-
Impaired loans transferred to foreclosed real estate			-				(1,457	)			1,457
Other than temporary impairment write downs			(157	)			-				-
Principal repayments/sales			-				(8,466	)			(4,944)
Chargeoffs of impaired loans			-				(2,476	)			-
Writedowns of carrying value subsequent to foreclosure			-				-				(2,933)
Balance at end of period			$4,221				$62,124				$21,858
We are also required by GAAP to disclose the estimated fair value of each class of our financial instruments for which it is practicable to estimate. The fair value of a financial instrument is the current estimated 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 our 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. Additionally, the estimated fair value of our non-financial instruments is excluded from these disclosure requirements. Accordingly, the aggregate fair value amounts presented in the table that follows may not necessarily represent the underlying fair value of our Company.
The fair value estimates shown in the table that follows are made at a specific point in time based on available information. A significant portion of our financial instruments, such as our mortgage loans, do not have an active marketplace in which they can be readily sold or purchased to determine fair value. Consequently, fair value estimates for such instruments are based on assumptions made by us that include the instrument’s credit risk characteristics and future estimated cash flows and prevailing interest rates. As a result, these fair value estimates are subjective in nature, involve uncertainties and matters of significant judgment and therefore, cannot be determined with precision.
Accordingly, changes in any of our assumptions could cause the fair value estimates to deviate substantially. Fair value estimates included herein are based on existing on- and off-balance-sheet financial instruments without attempting to estimate the value of anticipated future business and the fair value of assets and liabilities that are not required to be recorded or disclosed at fair value like premises and equipment. In addition, the tax ramifications related to the realization of the unrealized gains and losses can have a significant effect on fair value estimates and have not been considered in the estimates. A discussion regarding the assumptions used to compute the estimated fair values disclosed in the table that follows can be found in note 20 to the financial statements in our 2012 10-K.
The carrying and estimated fair values of our financial instruments are as follows:
		At September 30, 2013								At December 31, 2012
($ in thousands)		Carrying				Fair				Carrying			Fair
		Value				Value				Value			Value
Financial Assets:
Cash and cash equivalents (1)		$	30,253			$	30,253			$	60,395		$	60,395
Time deposits with banks (1)			5,370				5,370				5,170			5,170
Securities available for sale, net (1)			1,016				1,016				1,000			1,000
Securities held to maturity, net (2)			416,321				410,304				443,777			442,166
FRB and FHLB stock (3)			8,237				8,237				8,151			8,151
Loans receivable, net (3)			1,073,500				1,072,203				1,079,363			1,102,333
Loan fees receivable (3)			2,511				1,973				3,108			2,547
Accrued interest receivable (3)			4,735				4,735				5,191			5,191
Total Financial Assets		$	1,541,943			$	1,534,091			$	1,606,155		$	1,626,953
Financial Liabilities:
Deposits (3)		$	1,298,403				1,312,522			$	1,362,619		$	1,389,629
Accrued interest payable on deposits (3)			1,398				1,398				2,379			2,379
Borrowed funds plus accrued interest payable (3)			57,165				56,924				62,930			62,448
Off-Balance Sheet Financial Instruments:
Commitments to lend (3)			536				536				386			386
Total Financial Liabilities		$	1,357,502			$	1,371,380			$	1,428,314		$	1,454,842
Net Financial Assets		$	184,441			$	162,711			$	177,841		$	172,111
	(1)	We consider these fair value measurements to be Level 1.
	(2)	We consider these fair value measurements (except for those related to our corporate security investments, which are considered Level 3) to be Level 1.
	(3)	We consider these fair value measurements to be Level 3.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
General	'
	General
	Intervest Bancshares Corporation (“IBC”) is the parent company of Intervest National Bank (“INB”). References in this report to “we,” “us” and “our” refer to these entities on a consolidated basis, unless otherwise specified. For a description of our business, see note 1 to the financial statements in our 2012 Annual Report on Form 10-K (“2012 10-K”). Our accounting and reporting policies conform to U.S. generally accepted accounting principles (GAAP) and general practices within the banking industry and are described in note 1 to the financial statements in our 2012 10-K, as updated by the information in this Form 10-Q.
Principles of Consolidation and Basis of Presentation	'
	Principles of Consolidation and Basis of Presentation
	The condensed consolidated financial statements (“financial statements”) in this report have not been audited except for information derived from our audited 2012 consolidated financial statements and notes thereto and should be read in conjunction with our 2012 10-K. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted in this report pursuant to the rules and regulations of the Securities and Exchange Commission.
Use of Estimates	'
	Use of Estimates
	In preparing our financial statements, we are required to make estimates and assumptions that affect the reported amounts of assets, liabilities and disclosure of contingent liabilities as of the date of the financial statements, and revenues and expenses during the reporting periods. Actual results could differ from those estimates. Estimates that are particularly susceptible to significant change currently relate to the determination of our allowance for loan losses, valuation allowance for real estate losses, other than temporary impairment assessments of our security investments and the need for and amount of a valuation allowance for our deferred tax asset. These estimates involve a higher degree of complexity and subjectivity and may require assumptions about highly uncertain matters. Current market conditions increase the risk and complexity of the judgments in these estimates. In our opinion, all material adjustments necessary for a fair presentation of our financial condition and results of operations for the interim periods presented in this report have been made. These adjustments are of a normal recurring nature. All significant intercompany balances and transactions have been eliminated in consolidation. Our results of operations for the interim periods are not necessarily indicative of results that may be expected for the entire year or any other interim period.
Recent Accounting Standards Update	'
	Recent Accounting Standards Update
	In July 2012, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (ASU) 2012-02, “Testing Indefinite-Lived Intangible Assets for Impairment,” which, among other things, gives an entity the option to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that an indefinite-lived intangible asset is impaired. We adopted this ASU on January 1, 2013, and since we do not have intangible assets, it had no impact on our financial statements.
	In January 2013, the FASB issued ASU No. 2013-01, “Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities,” which limits the scope of the new balance sheet offsetting disclosures in ASU 2011-11 to derivatives, repurchase agreements, and securities lending transactions to the extent that they are (1) offset in the financial statements or (2) subject to an enforceable master netting arrangement or similar agreement. We adopted this ASU on February 1, 2013 and it had no impact on our financial statements.
	In February 2013, the FASB Issued ASU No. 2013-02, “Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income,” which requires entities to present information about reclassification adjustments from accumulated other comprehensive income in their annual financial statements in a single note or on the face of the financial statements. We adopted this ASU on March 1, 2013 and it had no impact on our financial statements.
	In February 2013, the FASB Issued ASU No. 2013-04, “Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation Is Fixed at the Reporting Date”. ASU 2013-04 provides guidance for the recognition, measurement, and disclosure of obligations resulting from joint and several liability arrangements for obligations within the scope of this ASU, which is effective January 1, 2014. Upon adoption, we do not expect this ASU to impact our financial statements.
	In July 2013, the FASB issued ASU 2013-11, “Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists,” which among other things, require an unrecognized tax benefit, or a portion of an unrecognized tax benefit, to be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, except as denoted within the ASU. The amendments in this ASU are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. We are currently evaluating the impact of ASU 2013-11 on our financial statements.
	In July 2013, the FASB issued ASU No. 2013-10, “Inclusion of the Fed Funds Effective Swap Rate (or Overnight Index Swap Rate) as a Benchmark Interest Rate for Hedge Accounting Purposes”. ASU No. 2013-10 permits the use of the Fed Funds Effective Swap Rate (OIS) to be used as a U.S. benchmark interest rate for hedge account purposes. The amendment is effective prospectively for qualifying new or redesiginated hedging relationships entered into on or after July 17, 2013. The adoption of ASU No. 2013-10 did have an impact on our financial statements.

Securities_Held_to_Maturity_an1

Securities Held to Maturity and Available for Sale (Tables)	9 Months Ended
	Sep. 30, 2013
Investments Debt And Equity Securities [Abstract]	'
Carrying Value (Amortized Cost) and Estimated Fair Value of Securities Held to Maturity	'
	The carrying value (amortized cost) and estimated fair value of securities held to maturity are as follows:
	($ in thousands)		Number of				Amortized				Gross				Gross				Estimated				Wtd-Avg				Wtd-Avg				Wtd-Avg
			Securities				Cost				Unrealized				Unrealized				Fair				Yield				Expected				Remaining
											Gains				Losses				Value								Life				Maturity
	At September 30, 2013
	U.S. government agencies (1)			176				$333,124			$	490			$	4,163			$	329,451				0.93%				2.9 Yrs				4.1 Yrs
	Residential mortgage-backed (2)			56				80,061				225				640				79,646				1.97%				4.6 Yrs				15.0 Yrs
	State and municipal			1				532				-				3				529				1.25%				3.5 Yrs				3.5 Yrs
	Corporate (3)			8				2,604				-				1,926				678				2.00%				19.5 Yrs				20.2 Yrs
				241				$416,321			$	715			$	6,732			$	410,304				1.14%				3.3Yrs				6.3 Yrs
	At December 31, 2012
	U.S. government agencies (1)			165				$355,244			$	1,109			$	233			$	356,120				0.87%				1.6 Yrs				4.6 Yrs
	Residential mortgage-backed (2)			48				84,279				651				72				84,858				1.76%				3.3 Yrs				17.3 Yrs
	State and municipal			1				533				-				3				530				1.25%				4.2 Yrs				4.3 Yrs
	Corporate (3)			8				3,721				-				3,063				658				2.11%				20.3 Yrs				20.9 Yrs
				222				$443,777			$	1,760			$	3,371			$	442,166				1.05%				2.0 Yrs				7.1 Yrs
	-1	Consist of debt obligations of U.S. government sponsored agencies (GSEs) - Federal Home Loan Bank (FHLB), Federal Farm Credit Bank (FFCB), Federal National Mortgage Association (FNMA) and Federal Home Loan Mortgage Corporation (FHLMC), which are federally chartered corporations privately owned by shareholders. GSE securities carry no explicit U.S. government guarantee of creditworthiness. Neither principal nor interest payments are guaranteed by the U.S. government nor do they not constitute a debt or obligation of the U.S. government or any of its agencies or instrumentalities other than the applicable GSE. In September 2008, FNMA and FHLMC were placed under U.S. government conservatorship.
	-2	At September 30, 2013, consisted of $14.5 million of Government National Mortgage Association (GNMA) pass-through certificates, $46.3 million of FNMA participation certificates and $19.3 million of FHLMC participation certificates. At December 31, 2012, consisted of $18.7 million of GNMA pass-through certificates, $40.0 million of FNMA participation certificates and $25.6 million of FHLMC participation certificates. The GNMA pass-through certificates are guaranteed as to the payment of principal and interest by the full faith and credit of the U.S. government while the FNMA and FHLMC certificates have an implied guarantee by such agency as to principal and interest payments.
	-3	Consist of variable-rate pooled trust preferred securities backed by obligations of companies in the banking industry. Amortized cost at September 30, 2013 and December 31, 2012 is reported net of other than temporary impairment charges of $5.2 million and $4.2 million, respectively.
Continuous Unrealized Loss Position	'
	The estimated fair values of securities held to maturity with gross unrealized losses segregated between securities that have been in a continuous unrealized loss position for less than twelve months at the respective dates and those that have been in a continuous unrealized loss position for twelve months or longer are summarized as follows:
							Less Than Twelve Months								Twelve Months or Longer								Total
	($ in thousands)		Number of				Estimated				Gross				Estimated				Gross				Estimated				Gross
			Securities				Fair				Unrealized				Fair				Unrealized				Fair				Unrealized
							Value				Losses				Value				Losses				Value				Losses
	At September 30, 2013
	U.S. government agencies			137				$257,171				$4,163				$        -				$        -				$257,171				$4,163
	Residential mortgage-backed			38				49,827				623				917				17				50,744				640
	State and municipal			1				529				3				-				-				529				3
	Corporate			8				-				-				678				1,926				678				1,926
				184				$307,527				$4,789				$1,595				$1,943				$309,122				$6,732
	At December 31, 2012
	U.S. government agencies			53				$129,365				$   233				$        -				$        -				$129,365				$   233
	Residential mortgage-backed			14				24,481				72				-				-				24,481				72
	State and municipal			1				530				3				-				-				530				3
	Corporate			8				-				-				658				3,063				658				3,063
				76				$154,376				$   308				$   658				$3,063				$155,034				$3,371
Other Information Related to Impaired Loans	'
	The following table provides various information regarding trust preferred securities.
	($ in thousands)		Credit		Cost				Write				Adj.				Estimated				Unrealized				% of Collateral								# of	Discount (4)				PV of
									Downs				Cost				Fair																Banks					Expected
	Cusip # (1)		Rating (1)		Basis				-2				Basis				Value (3)				Loss				Defaulted				Deferred				in Pool	Margin		Rate		Cash Flows
	At September 30, 2013
	74041PAEO		C			$  998				$   (918)				$     80				$  29				$    (51)				43.20%				14.80%			39		1.92%		5.22%		$   338
	74040XAD6		CC			995				-485				510				176				(334)				17.20%				9.80%			54		1.64%		5.17%		978
	74040XAE4		CC			973				-462				511				176				(335)				17.20%				9.80%			54		1.85%		5.39%		953
	74040XAE4		CC			973				-462				511				176				(335)				17.20%				9.80%			54		1.85%		5.39%		953
	74040YAF9		CC-			900				-767				133				33				(100)				29.00%				5.90%			58		1.88%		5.32%		769
	74040YAE2		CC-			919				-787				132				33				(99)				29.00%				5.90%			58		1.70%		5.14%		785
	74041UAE9		C+			1,021				-658				363				27				(336)				8.00%				29.00%			64		1.36%		4.78%		725
	74041UAE9		C+			1,022				-658				364				28				(336)				8.00%				29.00%			64		1.39%		4.81%		724
						$7,801				($5,197)				$2,604				$678				$(1,926)																	$6,225
	At December 31, 2012
	74041PAEO		C			$  999				$   (797)				$   202				$  31				$    (171)				39.23%				13.76%			39		1.92%		4.04%		$   348
	74040XAD6		C+			1,010				-316				694				180				(514)				16.31%				9.19%			54		1.64%		3.97%		989
	74040XAE4		C+			988				-294				694				180				(514)				16.31%				9.19%			54		1.85%		4.18%		959
	74040XAE4		C+			988				-294				694				180				(514)				16.31%				9.19%			54		1.85%		4.18%		959
	74040YAF9		C			952				-718				234				32				(202)				27.24%				13.28%			58		1.88%		4.04%		642
	74040YAE2		C			972				-737				235				32				(203)				27.24%				13.28%			58		1.70%		3.86%		655
	74041UAE9		C+			1,022				-539				483				11				(472)				7.80%				31.17%			64		1.36%		3.61%		638
	74041UAE9		C+			1,023				-538				485				12				(473)				7.80%				31.17%			64		1.39%		3.64%		636
						$7,954				($4,233)				$3,721				$658				$(3,063)																	$5,826
	(1) All of these securities were on cash basis accounting because INB is currently not receiving all scheduled contractual interest payments on these securities. A large portion of the contractual cash flows for the interest payments on these securities are being redirected to a more senior class of bondholders to pay down the principal balance on the more senior class faster. This occurs when deferral and default activity reduces the security’s underlying performing collateral to a level where a predetermined coverage test fails and requires cash flows from interest payments to be redirected to a senior class of security holders. If no additional deferrals or defaults occur, such test will eventually be met again through the redirection of the cash flow and cash interest payments would resume on INB’s bonds, although no assurance can be given as to the amount and timing of the resumption, if any. In the first nine months of 2013, INB received payments on cusips# 74040XAD6, 74040XAE4, 74040YAF9 and 74040YAE2 totaling approximately $153,000. The credit rating represents a composite rating derived from third party credit rating agencies (Moody’s and Fitch).
	(2) Writedowns are derived based on analysis of various factors and consider the difference between the book value of the security and the projected present value of the security’s cash flows as indicated per an analysis performed using guidance prescribed by GAAP.
	Notes to the preceding table continued:
	(3) Obtained from Moody’s pricing service, which uses a complex valuation model that factors in numerous assumptions and data, including anticipated discounts related to illiquid trading markets, credit and interest rate risk, which under GAAP would be considered Level 3 inputs. INB believes that the actual values that would be realized in an orderly market under normal credit conditions between a willing buyer and seller would approximate the projected present value (PV) of the securities’ cash flows and therefore, these estimated fair values are used for disclosure purposes only and are not used for calculating and recording impairment. INB also has the intent and the ability to retain these trust preferred securities until maturity and currently has no intention of selling them. We view the gross unrealized losses related to these securities to be temporary.
	(4) In determining whether there is OTTI, INB relies on a cash flow analysis as prescribed under GAAP (ASC 320-10-35) and prepared by a third party specialist to determine whether conditions are such that the projected cash flows are insufficient to recover INB’s principal investment. The basic methodology under GAAP is to compare the present value of the cash flows that are derived from assumptions made with respect to deferrals, defaults and prepayments from quarter to quarter. A decline in the present value versus that for the previous quarter is considered to be an adverse change. The discount margin in the table above represents the incremental credit spread used to derive the discount rate for present value computations. Consistent with GAAP, we analyze the specific credit characteristics of the collateral underlying each individual security to develop the deferral/default assumptions for estimated cash flows. This analysis consists of examining available data regarding trends in earnings and capital and problem asset ratios of each bank in the collateral pool in order to estimate their capacity to continue principal and interest payments on the investments we own. In order to estimate the expected cash flows, we focused on each bank’s Texas ratio, which is defined as nonperforming assets plus 90 day past due loans divided by tangible equity plus loan loss reserves. We concluded that banks with Texas ratios of 75% or more may experience greater difficulties in making payments. Based on our judgment, we determined and used the following assumptions in projecting cash flows: for those banks that were in default, we assumed no cash flows, for those banks that had deferred payments, we assumed a 15% recovery after a 2 year lag, and for banks that were paying we assumed prepayments of 1% annually and 100% at maturity and annual defaults of 75 basis points. It should be noted that the results of any discounted cash flow analysis are significantly affected by variables such as the estimate of the probability of default, discount rates, prepayment rates and the creditworthiness of the underlying issuers. Therefore, changes in any of these assumptions could cause the results of our cash flow models and OTTI assessments to deviate and result in different conclusions.
Credit Losses Recognized on Securities	'
	The table below provides a cumulative roll forward of credit losses recognized on securities held to maturity for the periods indicated.
			Quarter Ended September 30,								Nine-Months Ended September 30,
	($ in thousands)		2013				2012				2013				2012
	Balance at beginning of period			$4,924				$3,808				$4,233				$3,651
	Additional credit losses on debt securities for which OTTI was previously recognized			273				-				964				157
	Balance at end of period			$5,197				$3,808				$5,197				$3,808
Summary of the Carrying Value (Amortized Cost) and Fair Value of Securities Held to Maturity	'
	The following table is a summary of the carrying value (amortized cost) and fair value of securities held to maturity as of September 30, 2013, by remaining period to contractual maturity (ignoring earlier call dates, if any). Actual maturities may differ from contractual maturities because certain security issuers have the right to call or prepay their obligations. The amounts reported in the table below do not consider the effects of possible prepayments or unscheduled repayments of the securities held to maturity portfolio.
	($ in thousands)		Amortized				Estimated				Wtd-Avg
			Cost				Fair Value				Yield
	Due in one year or less			$  17,094				$    17,196				1.24%
	Due after one year through five years			243,465				241,627				0.85
	Due after five years through ten years			98,322				96,382				1.27
	Due after ten years			57,440				55,099				2.09
				$416,321				$410,304				1.14%

Loans_Receivable_Tables

Loans Receivable (Tables)	9 Months Ended
	Sep. 30, 2013
Receivables [Abstract]	'
Major Classifications of Loans Receivable	'
	Major classifications of loans receivable are summarized as follows:
			At September 30, 2013					At December 31, 2012
	($ in thousands)		# of Loans		Amount			# of Loans		Amount
	Loans Secured By Real Estate:
	Commercial loans			383		$  817,572			376		$   852,213
	Multifamily loans			139		210,508			142		208,699
	One to four family loans			19		68,662			13		41,676
	Land loans			4		5,881			7		7,167
				545		1,102,623			538		1,109,755
	All Other Loans:
	Business loans			19		1,130			18		949
	Consumer loans			14		347			12		359
				33		1,477			30		1,308
	Loans receivable, gross			578		1,104,100			568		1,111,063
	Deferred loan fees					(3,823)					(3,597)
	Loans receivable, net of deferred fees					1,100,277					1,107,466
	Allowance for loan losses					(26,777)					(28,103)
	Loans receivable, net					$1,073,500					$1,079,363
Summary of Impaired Loans	'
	The recorded investment, corresponding specific impairment valuation allowance and unpaid principal balance of our impaired loans at the dates indicated are summarized follows:
			-1																		-2		-3		# of
			Recorded Investment by State																		Specific		Total		Loans
																					Valuation		Unpaid
																					Allowance		Principal
	($ in thousands)		NY		FL			NJ		GA			CT		OH		SD		Total
	At September 30, 2013
	Commercial real estate:
	Retail		$	8,779	$	9,005		$	-	$	-		$	2,735	$	1,000	$	-	$	21,519		$1,661		$28,446		7
	Office Building			-		15,242			-		8,695			-		-		-		23,937		1,977		24,451		3
	Mixed Use			-		-			500		-			-		-		-		500		25		500		1
	Multifamily			-		3,140			-		-			-		-		-		3,140		596		3,140		2
	Land			-		-			-		-			-		-		1,802		1,802		498		1,802		1
	Totals		$	8,779	$	27,387		$	500	$	8,695		$	2,735	$	1,000	$	1,802	$	50,898		$4,757		$58,339		14
	At December 31, 2012
	Commercial Real Estate
	Retail		$	11,837	$	9,005		$	-	$	-		$	-	$	1,000	$	-	$	21,842		$1,966		$27,596		6
	Office Building			-		17,988			883		-			-		-		-		18,871		583		19,621		3
	Warehouse			950		-			-		-			-		-		-		950		28		950		1
	Mixed Use			8,632		-			500		-			-		-		-		9,132		1,248		9,421		4
	Multifamily			-		12,577			-		-			-		-		-		12,577		1,542		14,225		6
	Land			515		-			-		-			-		-		2,086		2,601		521		2,601		3
	Totals		$	21,934	$	39,570		$	1,383	$	-		$	-	$	1,000	$	2,086	$	65,973		$5,888		$74,414		23
	-1	Represents contractual unpaid principal less any partial principal chargeoffs and interest received and applied as a reduction of principal.
	-2	Represents a specific valuation allowance against the recorded investment included as part of the overall allowance for loan losses. All impaired loans at the dates indicated in the table had a specific valuation allowance.
	-3	Represents contractual unpaid principal balance (shown for informational purposes only). The borrowers are obligated to pay such amounts, however the ultimate collection by us of such amounts in this column cannot be assured
Other Information Related to Impaired Loans	'
	Other information related to our impaired loans is summarized as follows:
			Quarter Ended					Nine-Months Ended
			September 30,					September 30,
	($ in thousands)		2013		2012			2013		2012
	Average recorded investment in nonaccrual loans		$	39,159	$	49,788		$	41,039	$	53,809
	Total cash basis interest income recognized on nonaccrual loans			521		633			1,729		2,055
	Average recorded investment in accruing TDR loans			11,423		14,380			14,482		10,341
	Total interest income recognized on accruing TDR loans under modified terms			152		233			581		493
Age Analysis of Loan Portfolio by Segment	'
	Age analysis of our loan portfolio by segment at September 30, 2013 is summarized as follows:
	($ in thousands)		Total		Current			Past Due		Past Due			Past Due		Total		Total
			Portfolio					31-59		60-89			90 or more		Past Due		Classified
								Days		Days			Days				Nonaccrual
	Accruing Loans:
	Commercial real estate			$   780,338		$   758,670			$        -		$  3,265			$  18,403		$21,668		$          -
	Multifamily			208,225		208,225			-		-			-		-		-
	One to four family			68,662		68,662			-		-			-		-		-
	Land			5,881		5,881			-		-			-		-		-
	All other			1,477		1,477			-		-			-		-		-
	Total accruing loans			1,064,583		1,042,915			-		3,265			18,403		21,668		-
	Nonaccrual Loans (1):
	Commercial real estate			37,234		36,720			-		-			514		514		37,234
	Multifamily			2,283		2,283			-		-			-		-		2,283
	Total nonaccrual loans			39,517		39,003			-		-			514		514		39,517
	Total loans			$1,104,100		$1,081,918			$        -		$3,265			$18,917		$22,182		$39,517
	Age analysis of our loan portfolio by segment at December 31, 2012 is summarized as follows:
	($ in thousands)		Total		Current			Past Due		Past Due			Past Due		Total		Total
			Portfolio					31-59		60-89			90 or more		Past Due		Classified
								Days		Days			Days				Nonaccrual
	Accruing Loans:
	Commercial real estate			$   816,357		$   799,130			$12,836		$        -			$ 4,391		$17,227		$          -
	Multifamily			198,942		198,942			-		-			-		-		-
	One to four family			41,676		41,676			-		-			-		-		-
	Land			6,882		4,221			2,661		-			-		2,661		-
	All other			1,308		1,308			-		-			-		-		-
	Total accruing loans			1,065,165		1,045,277			15,497		-			4,391		19,888		-
	Nonaccrual Loans (1):
	Commercial real estate			35,856		32,701			-		-			3,155		3,155		35,856
	Multifamily			9,757		7,261			-		-			2,496		2,496		9,757
	Land			285		285			-		-			-		-		285
	Total nonaccrual loans			45,898		40,247			-		-			5,651		5,651		45,898
	Total loans			$1,111,063		$1,085,524			$15,497		$        -			$10,042		$25,539		$45,898
	-1	The amount of nonaccrual loans in the current column included $35.8 million of TDRs at September 30, 2013 and $36.3 million of TDRs at December 31, 2012 for which payments are being made in accordance with their restructured terms, but the loans were maintained on nonaccrual status in accordance with regulatory guidance. The remaining portion at both dates was comprised of certain paying loans classified nonaccrual due to concerns regarding the borrowers’ ability to continue making payments. Interest income from loan payments on all loans in nonaccrual status is recognized on a cash basis, provided the remaining principal balance is deemed collectible.
Information Regarding Credit Quality of Loan Portfolio	'
	Information regarding the credit quality of the loan portfolio based on internally assigned grades follows:
	($ in thousands)		Pass		Special Mention			Substandard (1)		Total
	At September 30, 2013
	Commercial real estate			$   743,233		$15,183			$59,156		$   817,572
	Multifamily			204,994		2,374			3,140		210,508
	One to four family			68,662		-			-		68,662
	Land			4,079		-			1,802		5,881
	All other			1,477		-			-		1,477
	Total loans			$1,022,445		$17,557			$64,098		$1,104,100
	Allocation of allowance for loan losses			$     20,626		$     410			$  5,741		$     26,777
	At December 31, 2012
	Commercial real estate			$   775,136		$17,041			$60,036		$   852,213
	Multifamily			193,738		2,384			12,577		208,699
	One to four family			41,676		-			-		41,676
	Land			4,566		-			2,601		7,167
	All other			1,308		-			-		1,308
	Total loans			$1,016,424		$19,425			$75,214		$1,111,063
	Allocation of allowance for loan losses			$     20,037		$     443			$  7,623		$     28,103
	-1	Substandard loans consist of $39.5 million of nonaccrual loans, $6.0 million of accruing TDRs and $18.6 million of other performing loans at September 30, 2013, compared to $45.9 million of nonaccrual loans, $20.1 million of accruing TDRs and $9.2 million of other performing loans at December 31, 2012. At September 30, 2013, we also had one accruing TDR for $5.4 million which was rated pass.
Geographic Distribution of Loan Portfolio	'
	The geographic distribution of the loan portfolio by state follows:
	($ in thousands)		At September 30, 2013					At December 31, 2012
			Amount		% of Total			Amount		% of Total
	New York		$	667,265		60	%	$	717,141		64.5	%
	Florida			314,274		29			286,619		25.8
	New Jersey			18,125		1.6			26,425		2.4
	North Carolina			17,746		1.6			14,256		1.3
	Pennsylvania			17,022		1.5			10,270		0.9
	Georgia			16,246		1.5			11,752		1.1
	Virginia			11,560		1			11,758		1.1
	Kentucky			10,619		1			7,512		0.7
	South Carolina			9,272		0.8			5,853		0.5
	Connecticut			8,482		0.8			11,216		1
	Tennessee			5,626		0.5			770		0
	Ohio			2,236		0.2			2,260		0.2
	South Dakota			1,802		0.2			2,086		0.2
	All other states			3,825		0.3			3,145		0.3
			$	1,104,100		100	%	$	1,111,063		100	%
Information Regarding Loans Restructured	'
	Information regarding loans restructured during the nine-months ended September 30, 2013 follows:
			Number		Recorded Investment
	($ in thousands)		of Loans		Pre-Modification			Post-Modification
	Commercial real estate - interest rate reduced			2	$	9,159		$	9,159
	Information regarding loans restructured during the nine-months ended September 30, 2012 is as follows:
			Number		Recorded Investment
	($ in thousands)		of Loans		Pre-Modification			Post-Modification
	Land - extended maturity date			2	$	520		$	520
Distribution of TDRs by Accruing Versus Non-Accruing, by Segment and by Geographic	'
	The distribution of TDRs by accruing versus non-accruing, by loan type and by geographic distribution follows:
	($ in thousands)		At September 30, 2013		At December 31, 2012
	Performing - nonaccrual status			$35,768		$36,291
	Performing - accrual status			11,381		20,076
				$47,149		$56,367
	Commercial real estate			$42,207		$43,685
	Multifamily			3,140		10,081
	Land			1,802		2,601
				$47,149		$56,367
	New York			$  8,265		$18,478
	Florida			27,387		33,920
	New Jersey			-		883
	Georgia			8,695		-
	Ohio			1,000		1,000
	South Dakota			1,802		2,086
				$47,149		$56,367

Allowance_for_Loan_Losses_Tabl

Allowance for Loan Losses (Tables)	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Allowance for Loan Losses by Loan Type	'
	Activity in the allowance for loan losses by loan type for the periods indicated is as follows:
	($ in thousands)		Commercial			Multifamily			One to Four		Land			All Other			Total
			Real Estate						Family
	Quarter Ended September 30, 2013
	Balance at beginning of period			$17,596			$5,098			$2,795		$   956			$10			$26,455
	Loan chargeoffs			-			-			-		-			-			-
	Loan recoveries (1)			67			5			-		-			-			72
	Provision (credit) for loan losses			(175	)		212			229		(15	)		(1	)		250
	Balance at end of period			$17,488			$5,315			$3,024		$   941			$  9			$26,777
	Quarter Ended September 30, 2012
	Balance at beginning of period			$18,343			$8,480			$   502		$1,509			$10			$28,844
	Loan chargeoffs			(548	)		-			-		-			-			(548)
	Loan recoveries			63			23			-		-			-			86
	Provision (credit) for loan losses			468			(381	)		250		(337	)		-			-
	Balance at end of period			$18,326			$8,122			$ 752		$1,172			$10			$28,382
	Activity in the allowance for loan losses by loan type for the periods indicated is as follows:
	($ in thousands)		Commercial			Multifamily			One to Four		Land			All Other			Total
			Real Estate						Family
	Nine-Months Ended September 30, 2013
	Balance at beginning of period			$19,051			$6,881			$1,120		$1,043			$  8			$28,103
	Loan chargeoffs			(1,932	)		(6	)		-		-			-			(1,938)
	Loan recoveries (1)			947			682			-		483			-			2,112
	Provision (credit) for loan losses			(578	)		(2,242	)		1,904		(585	)		1			(1,500)
	Balance at end of period			$17,488			$5,315			$3,024		$   941			$  9			$26,777
	Nine-Months Ended September 30, 2012
	Balance at beginning of period			$19,156			$8,848			$332		$2,069			$10			$30,415
	Loan chargeoffs			(2,215	)		(261	)		-		-			-			(2,476)
	Loan recoveries			383			60			-		-			-			443
	Provision for loan losses			1,002			(525	)		420		(897	)		-			-
	Balance at end of period			$18,326			$8,122			$752		$1,172			$10			$28,382
	-1	See note 14 to financial statements in this report for a discussion on recoveries.
Loans Receivable by Segment and Impairment Evaluation and Allowance for Loan Losses	'
	The following tables set forth the balances of our loans receivable by segment and impairment evaluation and the allowance for loan losses associated with such loans at the dates indicated.
	($ in thousands)		Commercial			Multifamily			One to Four		Land			All Other			Total
			Real Estate						Family
	At September 30, 2013
	Loans:
	Individually evaluated for impairment			$  45,955			$    3,141			$           -		$1,802			$         -			$     50,898
	Collectively evaluated for impairment			771,617			207,367			68,662		4,079			1,477			1,053,202
	Total loans			$817,572			$210,508			$68,662		$5,881			$1,477			$1,104,100
	Allowance for loan losses:
	Individually evaluated for impairment (1)			$    3,663			$       596			$           -		$   498			$        -			$       4,757
	Collectively evaluated for impairment			13,825			4,719			3,024		443			9			22,020
	Total allowance for loan losses			$  17,488			$   5,315			$3,024		$   941			$        9			$     26,777
	At December 31, 2012
	Loans:
	Individually evaluated for impairment			$  50,795			$  12,577			$           -		$2,601			$          -			$     65,973
	Collectively evaluated for impairment			801,418			196,122			41,676		4,566			1,308			1,045,090
	Total loans			$852,213			$208,699			$41,676		$7,167			$1,308			$1,111,063
	Allowance for loan losses:
	Individually evaluated for impairment (1)			$    3,825			$    1,542			$           -		$   521			$        -			$       5,888
	Collectively evaluated for impairment			15,226			5,339			1,120		522			8			22,215
	Total allowance for loan losses			$  19,051			$    6,881			$  1,120		$1,043			$       8			$     28,103
	(1) See note 3 to financial statements in this report.

Foreclosed_Real_Estate_and_Val1

Foreclosed Real Estate and Valuation Allowance for Real Estate Losses (Tables)	9 Months Ended
	Sep. 30, 2013
Banking And Thrift [Abstract]	'
Summary of Real Estate Acquired through Foreclosure by Property Type	'
	Real estate acquired through foreclosure by property type is summarized as follows:
		At September 30, 2013						At December 31, 2012
	($ in thousands)	# of Properties			Amount (1)			# of Properties			Amount (1)
	Commercial real estate		3			$  5,334			2			$2,790
	Multifamily		1			6,685			3			12,000
	Land		-			-			1			1,133
	Real estate acquired through foreclosure		4			$12,019			6			$15,923
	(1) Reported net of any associated valuation allowance.
Summary of Activity in the Valuation Allowance for Real Estate Losses	'
	Activity in the valuation allowance for real estate losses is summarized as follows:
		Quarter Ended						Nine-Months Ended
		September 30,						September 30,
	($ in thousands)	2013			2012			2013			2012
	Valuation allowance at beginning of period		$6,044			$7,945			$5,339			$6,037
	Provision for real estate losses		250			1,025			955			2,933
	Real estate chargeoffs		(4,171	)		(3,642	)		(4,171	)		(3,642)
	Valuation allowance at end of period		$2,123			$5,328			$2,123			$5,328

Deposits_Tables

Deposits (Tables)	9 Months Ended
	Sep. 30, 2013
Banking And Thrift [Abstract]	'
Scheduled Maturities of Certificates of Deposits	'
	Scheduled maturities of certificates of deposit accounts (CDs) are as follows:
		At September 30, 2013			At December 31, 2012
	($ in thousands)	Amount		Wtd-Avg	Amount		Wtd-Avg
				Stated Rate			Stated Rate
	Within one year		$434,055	2.91%		$519,236	2.92%
	Over one to two years		175,921	2.02		181,698	2.79
	Over two to three years		108,008	2.25		89,049	2.74
	Over three to four years		105,813	2.60		60,119	3.02
	Over four years		73,615	2.02		86,776	2.93
			$897,412	2.54%		$936,878	2.89%

Lines_of_Credit_Tables

Lines of Credit (Tables)	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Summary of Certain Information Regarding FHLB Advances	'
	The following is a summary of certain information regarding FHLB advances in the aggregate.
		At or For the Quarter Ended				At or For the Nine-Months Ended
		September 30,				September 30,
	($ in thousands)	2013		2012		2013		2012
	Balance at period end		-		$  7,000		-		$  7,000
	Maximum amount outstanding at any month end for the period		-		$10,500		-		$13,500
	Average outstanding balance for the period		-		$  9,511		-		$11,215
	Weighted-average interest rate paid for the period		-		4.31%		-		4.26%
	Weighted-average interest rate at period end		-		4.22%		-		4.22%

Subordinated_Debentures_Capita1

Subordinated Debentures - Capital Securities (Tables)	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Summary of Capital Securities Outstanding	'
	Capital Securities (commonly referred to as trust preferred securities) outstanding are summarized as follows:
		At September 30, 2013					At December 31, 2012
	($ in thousands)	Principal		Accrued		Interest	Principal		Accrued		Interest
				Interest		Rate			Interest		Rate
				Payable					Payable
	Capital Securities II - debentures due September 17, 2033		$15,464		$147	3.20%		$15,464		$1,661	3.26%
	Capital Securities III - debentures due March 17, 2034		15,464		139	3.04%		15,464		1,577	3.10%
	Capital Securities IV - debentures due September 20, 2034		15,464		119	2.65%		15,464		1,370	2.71%
	Capital Securities V - debentures due December 15, 2036		10,310		58	1.90%		10,310		1,620	1.96%
			$56,702		$463			$56,702		$6,228

Common_Stock_Warrant_Options_a1

Common Stock Warrant, Options and Restricted Common Stock (Tables)	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Summary of Selected Information Regarding Restricted Common Stock Awards made Under Plan	'
	A summary of activity in outstanding common stock options and related information follows:
			Exercise Price Per Warrant/Option																			Wtd-Avg.
																						Exercise
			$5.42 (1)			$17.10			$7.50			$4.02			$3.00			$2.55		Total		Price
	($ in thousands, except per share amounts)
	Outstanding at December 31, 2012			691,882			116,640			120,190			68,910			38,200			42,300		1,078,122		$6.63
	Forfeited/expired (2)			-			(1,200	)		(1,200	)		(1,100	)		(1,900	)		(3,300)		(8,700)		$5.52
	Options exercised			-			-			-			(9,600	)		(3,200	)		(2,167)		(14,967)		$3.59
	Outstanding at September 30, 2013			691,882			115,440			118,990			58,210			33,100			36,833		1,054,455		$6.68
	Expiration date			12/23/18			12/13/17			12/11/18			12/10/19			12/9/20			12/08/21
	Vested and exercisable (3)			100%			100%			100%			100%			67%			33%		96%
	Wtd-avg contractual remaining term (in years)			5.2			4.2			5.2			6.2			7.2			8.2		5.4
	Intrinsic value at September 30, 2013 (4)			$1,737			-			$51			$228			$163			$198		$2,377
	-1	This is the warrant held by the U.S. Treasury as described in note 9 to the financial statements in this report.
	-2	Represent options forfeited or expired unexercised.
	-3	The $3.00 options further vest and become 100% exercisable on December 9, 2013. The $2.55 options further vest and become exercisable at the rate of 33.33% on December 8, 2013 and 2014. Full vesting may occur earlier upon the occurrence of certain events as defined in the option agreement.
	-4	Intrinsic value was calculated using the closing price of IBC’s common stock on September 30, 2013 of $7.93.
Summary of Outstanding Common Stock Warrant and Options	'
	A summary of selected information regarding restricted common stock awards made under the Plans during the nine months ended September 30, 2013 and 2012 follows:
	($ in thousands, except per share amounts)		Stock Grant			Stock Grant
	Grant date of award			1/24/13			1/19/12
	Total restricted shares of stock awarded (1)			330,700			465,400
	Estimated fair value per share awarded (2)			$4.50			$2.90
	Total estimated fair value of award			$1,488			$1,350
	Awards scheduled to vest as follows:
	Jan-13			-			256,800
	Jan-14			49,566			133,455
	Jan-15			170,888			75,145
	Jan-16			110,246			-
				330,700			465,400
	-1	For the 2012 period, awards were as follows: a total of 175,000 shares to five executive officers (vesting in two installments, with two thirds vesting on the second anniversary of the grant and the remaining one third on the third anniversary of the grant); a total of 240,000 shares to six non-employee directors (vesting 100% on the first anniversary of the grant); and a total of 50,400 shares to other officers and employees (vesting in three equal installments, with one third on each of the next three anniversary dates of the grant).
	For the 2013 period, awards were as follows: a total of 182,000 shares to five executive officers (vesting in two installments, with two thirds vesting on the second anniversary of the grant and the remaining one third on the third anniversary of the grant); a total of 80,000 shares to eight non-employee directors and 68,700 shares to other officers and employees (vesting in three equal installments, with one third on each of the next three anniversary dates of the grant).
	-2	Fair value of each award was estimated as of the grant date based on the closing market price of the common stock on the grant date.
Summary of Activity in IBCs Restricted Class A Common Stock	'
	A summary of activity in outstanding restricted common stock and related information follows:
			Price Per Share
			$2.35			$2.90			$4.50			Total
	Outstanding at December 31, 2012			317,500			464,800			-			782,300
	Shares vested and no longer restricted			-			(256,600	)		-			(256,600)
	Shares granted			-			-			330,700			330,700
	Shares forfeited			(7,100	)		(6,133	)		(5,400)			(18,633)
	Outstanding at September 30, 2013 (1) (2)			310,400			202,067			325,300			837,767
	Notes to the preceding table follow:
	-1	All outstanding shares of restricted common stock were unvested at September 30, 2013 and subject to forfeiture. Shares issued at a price of $2.35 on December 9, 2010 will vest 100% on December 9, 2013. Shares issued at a price of $2.90 on January 19, 2012 will vest as follows: 130,200 on January 19, 2014 and 71,867 on January 19, 2015. Shares issued at a price of $4.50 on January 24, 2013 will vest as follows: 47,767 on January 24, 2014, 169,100 on January 24, 2015 and 108,433 on January 24, 2016.
	-2	Vesting is subject to the grantee’s continued employment with us or, in the case of non-employee directors, the grantee’s continued service as our director on the vesting dates. All of the awards are subject to accelerated vesting upon the death or disability of the grantee or upon a change in control of IBC, as defined in the restricted stock agreements. The record holder of IBC’s restricted shares of common stock possesses all the rights of a holder of our common stock, including the right to receive dividends on and to vote the restricted shares. The restricted shares may not be sold, transferred, pledged, assigned, encumbered, or otherwise alienated or hypothecated until they become fully vested and transferable in accordance with the agreements. Prior to June 24, 2013, shares held by certain of our executive officers had further restrictions on transferability due to IBC’s participation in the TARP program.

Earnings_Per_Common_Share_Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Summary of Basic and Diluted Earnings Per Common Share	'
	Net earnings applicable to common stockholders and the weighted-average number of shares used for basic and diluted earnings per common share computations are summarized in the table that follows:
			Quarter Ended				Nine-Months Ended
			September 30,				September 30,
			2013		2012		2013		2012
	Basic Earnings Per Common Share:
	Net earnings available to common stockholders			$2,588,000		$2,225,000		$9,230,000		$7,347,000
	Weighted-Average number of common shares outstanding			21,915,596		21,589,744		21,891,886		21,558,092
	Basic Earnings Per Common Share			$0.12		$0.10		$0.42		$0.34
	Diluted Earnings Per Common Share:
	Net earnings available to common stockholders			$2,588,000		$2,225,000		$9,230,000		$7,347,000
	Weighted-Average number of common shares outstanding:
	Common shares outstanding			21,915,596		21,589,744		21,891,886		21,558,092
	Potential dilutive shares resulting from exercise of warrants /options (1)			135,866		978		81,064		276
	Total average number of common shares outstanding used for dilution			22,051,462		21,590,722		21,972,950		21,558,368
	Diluted Earnings Per Common Share			$0.12		$0.10		$0.42		$0.34
	-1	All outstanding options/warrants to purchase shares of our common stock were considered for the Diluted EPS computations and only those that were dilutive (as determined by using the treasury stock method prescribed by GAAP) were included in the diluted earnings per share computations above. For both the quarter and nine-month periods of 2013 and 2012 calculations, 234,430 and 1,041,122, respectively, of options/warrants to purchase shares of common stock were not dilutive because the exercise price per share of each option/warrant was above the average market price of our common stock during these periods.

OffBalance_Sheet_Financial_Ins1

Off-Balance Sheet Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2013
Investments All Other Investments [Abstract]	'
Summary of Contractual Amounts of Off-Balance Sheet Financial Instruments	'
	The contractual amounts of off-balance sheet financial instruments are as follows:
	($ in thousands)	At September 30, 2013		At December 31, 2012
	Commitments to extend credit		$30,672		$19,154
	Unused lines of credit		677		854
			$31,349		$20,008

Regulatory_Matters_and_Regulat1

Regulatory Matters and Regulatory Capital (Tables)	9 Months Ended
	Sep. 30, 2013
Banking And Thrift [Abstract]	'
Summary of Regulatory Capital and Related Ratios	'
	Information regarding our regulatory capital and related ratios is summarized as follows:
			INB				IBC Consolidated
			At September 30,		At December 31,		At September 30,		At December 31,
	($ in thousands)		2013		2012		2013		2012
	Tier 1 capital (1)			$234,166		$244,081		$238,955		$249,465
	Tier 2 capital			15,377		15,566		15,416		15,620
	Total risk-based capital			$249,543		$259,647		$254,371		$265,085
	Net risk-weighted assets for regulatory purposes			$1,218,718		$1,232,670		$1,221,807		$1,238,024
	Average assets for regulatory purposes			$1,563,834		$1,690,329		$1,568,881		$1,696,410
	Total capital to risk-weighted assets			20.48%		21.06%		20.82%		21.41%
	Tier 1 capital to risk-weighted assets			19.21%		19.80%		19.56%		20.15%
	Tier 1 capital to average assets			14.97%		14.44%		15.23%		14.71%
	-1	IBC’s consolidated Tier 1 capital for both dates included $55 million of IBC’s outstanding qualifying trust preferred securities, which are discussed in further detail in note 8 to the financial statements in this report .
Capital Adequacy	'
	The table that follows presents information regarding our actual capital and minimum capital requirements.
			Actual Capital				Minimum				Minimum				Minimum
							Under Prompt				To Be “Well Capitalized”				Under Agreement
							Corrective				Under Prompt Corrective				With OCC
							Action Provisions				Action Provisions
	($ in thousands)		Amount		Ratio		Amount		Ratio		Amount		Ratio		Amount		Ratio
	IBC Consolidated at September 30, 2013:
	Total capital to risk-weighted assets (1)			$254,371		20.82%		$97,745		8.00%		NA		NA		NA		NA
	Tier 1 capital to risk-weighted assets (1)			$238,955		19.56%		$48,872		4.00%		NA		NA		NA		NA
	Tier 1 capital to average assets (1)			$238,955		15.23%		$62,755		4.00%		NA		NA		NA		NA
	IBC Consolidated at December 31, 2012:
	Total capital to risk-weighted assets			$265,085		21.41%		$99,042		8.00%		NA		NA		NA		NA
	Tier 1 capital to risk-weighted assets			$249,465		20.15%		$49,521		4.00%		NA		NA		NA		NA
	Tier 1 capital to average assets			$249,465		14.71%		$67,856		4.00%		NA		NA		NA		NA
	INB at September 30, 2013:
	Total capital to risk-weighted assets			$249,543		20.48%		$97,497		8.00%		$121,872		10.00%		NA		NA
	Tier 1 capital to risk-weighted assets			$234,166		19.21%		$48,749		4.00%		$  73,123		6.00%		NA		NA
	Tier 1 capital to average assets			$234,166		14.97%		$62,553		4.00%		$  78,192		5.00%		NA		NA
	INB at December 31, 2012:
	Total capital to risk-weighted assets			$259,647		21.06%		$98,614		8.00%		$123,267		10.00%		$147,920		12.00%
	Tier 1 capital to risk-weighted assets			$244,081		19.80%		$49,307		4.00%		$  73,960		6.00%		$123,267		10.00%
	Tier 1 capital to average assets			$244,081		14.44%		$67,613		4.00%		$  84,516		5.00%		$152,130		9.00%
	-1	Assuming IBC had excluded all of its eligible outstanding trust preferred securities (which totaled $55 million) from its Tier 1 capital and included the entire amount in its Tier 2 capital, consolidated proforma capital ratios at September 30, 2013 would have been 20.82%, 15.06% and 11.73%, respectively.
Additional Information Regarding Capital Adequacy	'
	The table that follows presents additional information regarding our capital adequacy at September 30, 2013.
			INB Regulatory Capital						Consolidated Regulatory Capital
	($ in thousands)		Actual		Required (1)		Excess		Actual		Required		Excess
	Total capital to risk-weighted assets			$249,543		$121,872		$127,671		$254,371		$97,745		$156,626
	Tier 1 capital to risk-weighted assets			$234,166		$  73,123		$161,043		$238,955		$48,872		$190,083
	Tier 1 capital to average assets			$234,166		$  78,192		$155,974		$238,955		$62,755		$176,200
	(1) Minimum amount required to be considered “Well-Capitalized.”

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Assets Measured at Fair Value on a Nonrecurring Basis	'
	The following tables provide information regarding our assets measured at fair value on a nonrecurring basis.
					Outstanding Carrying Value
			At September 30, 2013						At December 31, 2012
	($ in thousands)				Level 3				Level 3
	Impaired loans (1):
	Commercial real estate					$45,956				$50,795
	Multifamily					3,140				12,577
	Land					1,802				2,601
	Total impaired loans					50,898				65,973
	Impaired securities (2)					2,604				3,721
	Real estate acquired through foreclosure					12,019				15,923
			Accumulated Losses on								Total Losses (Gains) (3)
			Outstanding Balance as of:								Quarter Ended						Nine-Months Ended
			September 30,				December 31,				September 30,						September 30,
	($ in thousands)		2013				2012				2013			2012			2013			2012
	Impaired loans:
	Commercial real estate			$10,294				$  9,979				$    -			$  (254	)		$  823			$  (241)
	Multifamily			598				3,092				(7	)		(170	)		(964	)		(100)
	Land			500				521				(2	)		-			(23	)		(493)
	Total impaired loans			11,392				13,592				(9	)		(424	)		(164	)		(834)
	Impaired securities			5,197				4,233				273			-			964			157
	Foreclosed real estate			2,123				5,339				149			1,025			135			2,933
	Totals			$18,712				$23,164				$413			$     601			$935			$2,256
	-1	Comprised of all nonaccrual loans and accruing TDRs. Outstanding carrying value excludes a specific valuation allowance included in the overall allowance for loan losses. See note 4 to the financial statements in this report.
	-2	Comprised of certain held-to maturity investments in trust preferred securities considered other than temporarily impaired. See note 2 to the financial statements in this report.
	-3	Represents total losses or (gains) recognized on all assets measured at fair value on a nonrecurring basis during the period indicated. The losses or (gains) for impaired loans represent the change (before net chargeoffs) during the period in the corresponding specific valuation allowance, while the losses (gains) for foreclosed real estate represent writedowns in carrying values subsequent to foreclosure (recorded as provisions for real estate losses) adjusted for any recoveries of prior writedowns and gains or losses from the transfer/sale of the properties during the period. The losses on investment securities represent other than temporary impairment “OTTI” writedowns recorded as a component of noninterest income (as described in note 2 to the financial statements in this report).
Change in Assets Measured at Fair Value on a Nonrecurring Basis	'
	The following table presents information regarding the change in assets measured at fair value on a nonrecurring basis for the periods indicated
	($ in thousands)		Impaired				Impaired				Foreclosed
			Securities				Loans				Real Estate
	Quarter Ended September 30, 2013
	Balance at beginning of period			$2,923				$50,533				$14,869
	Net new impaired loans			-				514				-
	Other than temporary impairment write downs			(273	)			-				-
	Principal repayments/sales			(46	)			(149	)			-2,701
	Writedowns of carrying value subsequent to foreclosure			-				-				-250
	Gains from sales			-				-				101
	Balance at end of period			$2,604				$50,898				$12,019
	Nine-Months Ended September 30, 2013
	Balance at beginning of period			$3,721				$65,973				$15,923
	Net new impaired loans			-				8,761				-
	Impaired loans transferred to foreclosed real estate			-				(3,040	)			3,040
	Other than temporary impairment write downs			(964	)			-				-
	Principal repayments/sales			(153	)			(18,858	)			-6,809
	Chargeoffs of impaired loans			-				(1,938	)			-
	Writedowns of carrying value subsequent to foreclosure			-				-				-1,029
	Recoveries of prior writedowns			-				-				74
	Gains from sales			-				-				820
	Balance at end of period			$2,604				$50,898				$12,019
	The following table presents information regarding the change in assets measured at fair value on a nonrecurring basis for the periods indicated.
	($ in thousands)		Impaired				Impaired				Foreclosed
			Securities				Loans				Real Estate
	Quarter Ended September 30, 2012
	Balance at beginning of period			$4,221				$65,240				$26,370
	Net new impaired loans			-				872				-
	Impaired loans transferred to foreclosed real estate			-				(1,457	)			1,457
	Principal repayments/sales			-				(1,983	)			(4,944)
	Chargeoffs of impaired loans			-				(548	)			-
	Writedowns of carrying value subsequent to foreclosure			-				-				(1,025)
	Balance at end of period			$4,221				$62,124				$21,858
	Nine-Months Ended September 30, 2012
	Balance at beginning of period			$4,378				$66,269				$28,278
	Net new impaired loans			-				8,254				-
	Impaired loans transferred to foreclosed real estate			-				(1,457	)			1,457
	Other than temporary impairment write downs			(157	)			-				-
	Principal repayments/sales			-				(8,466	)			(4,944)
	Chargeoffs of impaired loans			-				(2,476	)			-
	Writedowns of carrying value subsequent to foreclosure			-				-				(2,933)
	Balance at end of period			$4,221				$62,124				$21,858
Carrying and Estimated Fair Values of Financial Instruments	'
	The carrying and estimated fair values of our financial instruments are as follows:
			At September 30, 2013								At December 31, 2012
	($ in thousands)		Carrying				Fair				Carrying			Fair
			Value				Value				Value			Value
	Financial Assets:
	Cash and cash equivalents (1)		$	30,253			$	30,253			$	60,395		$	60,395
	Time deposits with banks (1)			5,370				5,370				5,170			5,170
	Securities available for sale, net (1)			1,016				1,016				1,000			1,000
	Securities held to maturity, net (2)			416,321				410,304				443,777			442,166
	FRB and FHLB stock (3)			8,237				8,237				8,151			8,151
	Loans receivable, net (3)			1,073,500				1,072,203				1,079,363			1,102,333
	Loan fees receivable (3)			2,511				1,973				3,108			2,547
	Accrued interest receivable (3)			4,735				4,735				5,191			5,191
	Total Financial Assets		$	1,541,943			$	1,534,091			$	1,606,155		$	1,626,953
	Financial Liabilities:
	Deposits (3)		$	1,298,403				1,312,522			$	1,362,619		$	1,389,629
	Accrued interest payable on deposits (3)			1,398				1,398				2,379			2,379
	Borrowed funds plus accrued interest payable (3)			57,165				56,924				62,930			62,448
	Off-Balance Sheet Financial Instruments:
	Commitments to lend (3)			536				536				386			386
	Total Financial Liabilities		$	1,357,502			$	1,371,380			$	1,428,314		$	1,454,842
	Net Financial Assets		$	184,441			$	162,711			$	177,841		$	172,111
		(1)	We consider these fair value measurements to be Level 1.
		(2)	We consider these fair value measurements (except for those related to our corporate security investments, which are considered Level 3) to be Level 1.
		(3)	We consider these fair value measurements to be Level 3.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - Additional Information (Detail)	Sep. 30, 2013	Dec. 31, 2012
Significant Accounting Policies [Line Items]	'	'
Capital to risk-weighted assets ratio	19.56%	20.15%
Capital conservation buffer	2.50%	'
Ratio of Tier 1 capital to risk-weighted assets	4.00%	4.00%
Minimum leverage ratio	4.00%	'
Minimum [Member]	'	'
Significant Accounting Policies [Line Items]	'	'
Ratio of Tier 1 capital to risk-weighted assets	4.00%	'
Maximum [Member]	'	'
Significant Accounting Policies [Line Items]	'	'
Ratio of Tier 1 capital to risk-weighted assets	6.00%	'

Securities_Held_to_Maturity_an2

Securities Held to Maturity and Available for Sale - Carrying Value (Amortized Cost) and Estimated Fair Value of Securities Held to Maturity (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Security	Security
Schedule of Held-to-maturity Securities [Line Items]	'	'
Number of Securities	241	222
Amortized Cost	$416,321	$443,777
Gross Unrealized Gains	715	1,760
Gross Unrealized Losses	6,732	3,371
Estimated Fair Value	410,304	442,166
Wtd-Avg Yield	1.14%	1.05%
Wtd-Avg Expected Life	'3 years 3 months 18 days	'2 years
Wtd-Avg Remaining Maturity	'6 years 3 months 18 days	'7 years 1 month 6 days
U.S. Government Agencies [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Number of Securities	176	165
Amortized Cost	333,124	355,244
Gross Unrealized Gains	490	1,109
Gross Unrealized Losses	4,163	233
Estimated Fair Value	329,451	356,120
Wtd-Avg Yield	0.93%	0.87%
Wtd-Avg Expected Life	'2 years 10 months 24 days	'1 year 7 months 6 days
Wtd-Avg Remaining Maturity	'4 years 1 month 6 days	'4 years 7 months 6 days
Residential Mortgage-backed [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Number of Securities	56	48
Amortized Cost	80,061	84,279
Gross Unrealized Gains	225	651
Gross Unrealized Losses	640	72
Estimated Fair Value	79,646	84,858
Wtd-Avg Yield	1.97%	1.76%
Wtd-Avg Expected Life	'4 years 7 months 6 days	'3 years 3 months 18 days
Wtd-Avg Remaining Maturity	'15 years	'17 years 3 months 18 days
State and Municipal [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Number of Securities	1	1
Amortized Cost	532	533
Gross Unrealized Losses	3	3
Estimated Fair Value	529	530
Wtd-Avg Yield	1.25%	1.25%
Wtd-Avg Expected Life	'3 years 6 months	'4 years 2 months 12 days
Wtd-Avg Remaining Maturity	'3 years 6 months	'4 years 3 months 18 days
Corporate [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Number of Securities	8	8
Amortized Cost	2,604	3,721
Gross Unrealized Losses	1,926	3,063
Estimated Fair Value	$678	$658
Wtd-Avg Yield	2.00%	2.11%
Wtd-Avg Expected Life	'19 years 6 months	'20 years 3 months 18 days
Wtd-Avg Remaining Maturity	'20 years 2 months 12 days	'20 years 10 months 24 days

Securities_Held_to_Maturity_an3

Securities Held to Maturity and Available for Sale - Carrying Value (Amortized Cost) and Estimated Fair Value of Securities Held to Maturity (Parenthetical) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	$416,321,000	$443,777,000
Other than temporary impairment charges	5,200,000	4,200,000
Government National Mortgage Association [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	14,500,000	18,700,000
Federal National Mortgage Association [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	46,300,000	40,000,000
Federal Home Loan Mortgage Corporation Participation Certificates [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	$19,300,000	$25,600,000

Securities_Held_to_Maturity_an4

Securities Held to Maturity and Available for Sale - Continuous Unrealized Loss Position (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Security	Security
Long Term Debt Maturity [Line Items]	'	'
Number of Securities	184	76
Less Than Twelve Months, Estimated Fair Value	$307,527	$154,376
Less Than Twelve Months, Gross Unrealized Losses	4,789	308
Twelve Months or Longer, Estimated Fair Value	1,595	658
Twelve Months or Longer, Gross Unrealized Losses	1,943	3,063
Total Estimated Fair Value	309,122	155,034
Total Gross Unrealized Losses	6,732	3,371
U.S. Government Agencies [Member]	'	'
Long Term Debt Maturity [Line Items]	'	'
Number of Securities	137	53
Less Than Twelve Months, Estimated Fair Value	257,171	129,365
Less Than Twelve Months, Gross Unrealized Losses	4,163	233
Total Estimated Fair Value	257,171	129,365
Total Gross Unrealized Losses	4,163	233
Residential Mortgage-backed [Member]	'	'
Long Term Debt Maturity [Line Items]	'	'
Number of Securities	38	14
Less Than Twelve Months, Estimated Fair Value	49,827	24,481
Less Than Twelve Months, Gross Unrealized Losses	623	72
Twelve Months or Longer, Estimated Fair Value	917	'
Twelve Months or Longer, Gross Unrealized Losses	17	'
Total Estimated Fair Value	50,744	24,481
Total Gross Unrealized Losses	640	72
State and Municipal [Member]	'	'
Long Term Debt Maturity [Line Items]	'	'
Number of Securities	1	1
Less Than Twelve Months, Estimated Fair Value	529	530
Less Than Twelve Months, Gross Unrealized Losses	3	3
Total Estimated Fair Value	529	530
Total Gross Unrealized Losses	3	3
Corporate [Member]	'	'
Long Term Debt Maturity [Line Items]	'	'
Number of Securities	8	8
Twelve Months or Longer, Estimated Fair Value	678	658
Twelve Months or Longer, Gross Unrealized Losses	1,926	3,063
Total Estimated Fair Value	678	658
Total Gross Unrealized Losses	$1,926	$3,063

Securities_Held_to_Maturity_an5

Securities Held to Maturity and Available for Sale - Other Information Related to Impaired Loans (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Long Term Debt Maturity [Line Items]	'	'
Estimated Fair Value	$410,304	$442,166
Unrealized Loss	-6,732	-3,371
Trust Preferred Securities [Member]	'	'
Long Term Debt Maturity [Line Items]	'	'
Cost Basis	7,801	7,954
Write Downs	-5,197	-4,233
Adj. Cost Basis	2,604	3,721
Estimated Fair Value	678	658
Unrealized Loss	-1,926	-3,063
PV of Expected Cash Flows	6,225	5,826
Trust Preferred Securities [Member] | 74041PAEO [Member]	'	'
Long Term Debt Maturity [Line Items]	'	'
Credit Rating	'C	'C
Cost Basis	998	999
Write Downs	-918	-797
Adj. Cost Basis	80	202
Estimated Fair Value	29	31
Unrealized Loss	-51	-171
% of Collateral Defaulted	43.20%	39.23%
% of Collateral Deferred	14.80%	13.76%
# of Banks in Pool	39	39
Discount Margin	1.92%	1.92%
Discount rate	5.22%	4.04%
PV of Expected Cash Flows	338	348
Trust Preferred Securities [Member] | 74040XAD6 [Member]	'	'
Long Term Debt Maturity [Line Items]	'	'
Credit Rating	'CC	'C+
Cost Basis	995	1,010
Write Downs	-485	-316
Adj. Cost Basis	510	694
Estimated Fair Value	176	180
Unrealized Loss	-334	-514
% of Collateral Defaulted	17.20%	16.31%
% of Collateral Deferred	9.80%	9.19%
# of Banks in Pool	54	54
Discount Margin	1.64%	1.64%
Discount rate	5.17%	3.97%
PV of Expected Cash Flows	978	989
Trust Preferred Securities [Member] | 74040XAE4 [Member]	'	'
Long Term Debt Maturity [Line Items]	'	'
Credit Rating	'CC	'C+
Cost Basis	973	988
Write Downs	-462	-294
Adj. Cost Basis	511	694
Estimated Fair Value	176	180
Unrealized Loss	-335	-514
% of Collateral Defaulted	17.20%	16.31%
% of Collateral Deferred	9.80%	9.19%
# of Banks in Pool	54	54
Discount Margin	1.85%	1.85%
Discount rate	5.39%	4.18%
PV of Expected Cash Flows	953	959
Trust Preferred Securities [Member] | 74040XAE4 [Member]	'	'
Long Term Debt Maturity [Line Items]	'	'
Credit Rating	'CC	'C+
Cost Basis	973	988
Write Downs	-462	-294
Adj. Cost Basis	511	694
Estimated Fair Value	176	180
Unrealized Loss	-335	-514
% of Collateral Defaulted	17.20%	16.31%
% of Collateral Deferred	9.80%	9.19%
# of Banks in Pool	54	54
Discount Margin	1.85%	1.85%
Discount rate	5.39%	4.18%
PV of Expected Cash Flows	953	959
Trust Preferred Securities [Member] | 74040YAF9 [Member]	'	'
Long Term Debt Maturity [Line Items]	'	'
Credit Rating	'CC-	'C
Cost Basis	900	952
Write Downs	-767	-718
Adj. Cost Basis	133	234
Estimated Fair Value	33	32
Unrealized Loss	-100	-202
% of Collateral Defaulted	29.00%	27.24%
% of Collateral Deferred	5.90%	13.28%
# of Banks in Pool	58	58
Discount Margin	1.88%	1.88%
Discount rate	5.32%	4.04%
PV of Expected Cash Flows	769	642
Trust Preferred Securities [Member] | 74040YAE2 [Member]	'	'
Long Term Debt Maturity [Line Items]	'	'
Credit Rating	'CC-	'C
Cost Basis	919	972
Write Downs	-787	-737
Adj. Cost Basis	132	235
Estimated Fair Value	33	32
Unrealized Loss	-99	-203
% of Collateral Defaulted	29.00%	27.24%
% of Collateral Deferred	5.90%	13.28%
# of Banks in Pool	58	58
Discount Margin	1.70%	1.70%
Discount rate	5.14%	3.86%
PV of Expected Cash Flows	785	655
Trust Preferred Securities [Member] | 74041UAE9 [Member]	'	'
Long Term Debt Maturity [Line Items]	'	'
Credit Rating	'C+	'C+
Cost Basis	1,021	1,022
Write Downs	-658	-539
Adj. Cost Basis	363	483
Estimated Fair Value	27	11
Unrealized Loss	-336	-472
% of Collateral Defaulted	8.00%	7.80%
% of Collateral Deferred	29.00%	31.17%
# of Banks in Pool	64	64
Discount Margin	1.36%	1.36%
Discount rate	4.78%	3.61%
PV of Expected Cash Flows	725	638
Trust Preferred Securities [Member] | 74041UAE9 [Member]	'	'
Long Term Debt Maturity [Line Items]	'	'
Credit Rating	'C+	'C+
Cost Basis	1,022	1,023
Write Downs	-658	-538
Adj. Cost Basis	364	485
Estimated Fair Value	28	12
Unrealized Loss	-336	-473
% of Collateral Defaulted	8.00%	7.80%
% of Collateral Deferred	29.00%	31.17%
# of Banks in Pool	64	64
Discount Margin	1.39%	1.39%
Discount rate	4.81%	3.64%
PV of Expected Cash Flows	$724	$636

Securities_Held_to_Maturity_an6

Securities Held to Maturity and Available for Sale - Other Information Related to Impaired Loans (Parenthetical) (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013
Long Term Debt Maturity [Line Items]	'
Interest payment received on cusips# 74040XAD6, 74040XAE4, 74040YAF9 and 74040YAE2	$153,000
OTTI assumptions, annual default recovery rate	15.00%
OTTI assumptions, default recovery lag period	'2 years
OTTI assumptions, annual prepayment percentage	1.00%
OTTI assumptions, prepayment percentage at maturity	100.00%
OTTI assumptions, annual default rate	0.75%
Other assumptions utilized	'We assumed a 15% recovery after a 2 year lag, and for banks that were paying we assumed prepayments of 1% annually and 100% at maturity and annual defaults of 75 basis points.
Minimum [Member]	'
Long Term Debt Maturity [Line Items]	'
Texas ratio	0.75

Securities_Held_to_Maturity_an7

Securities Held to Maturity and Available for Sale - Credit Losses Recognized on Securities (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Investments Debt And Equity Securities [Abstract]	'	'	'	'
Balance at beginning of period	$4,924	$3,808	$4,233	$3,651
Additional credit losses on debt securities for which OTTI was previously recognized	273	'	964	157
Balance at end of period	$5,197	$3,808	$5,197	$3,808

Securities_Held_to_Maturity_an8

Securities Held to Maturity and Available for Sale - Summary of Carrying Value (Amortized Cost) and Fair Value of Securities Held to Maturity (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Investments Debt And Equity Securities [Abstract]	'	'
Due in one year or less, Amortized Cost	$17,094	'
Due in one year or less, Estimated Fair Value	17,196	'
Due in one year or less, Wtd-Avg Yield	1.24%	'
Due after one year through five years, Amortized Cost	243,465	'
Due after one year through five years, Estimated Fair Value	241,627	'
Due after one year through five years, Wtd-Avg Yield	0.85%	'
Due after five years through ten years, Amortized Cost	98,322	'
Due after five years through ten years, Estimated Fair Value	96,382	'
Due after five years through ten years, Wtd-Avg Yield	1.27%	'
Due after ten years, Amortized Cost	57,440	'
Due after ten years, Estimated Fair Value	55,099	'
Due after ten years, Wtd-Avg Yield	2.09%	'
Securities held to maturity, Total Amortized Cost	416,321	'
Estimated Fair Value	$410,304	$442,166
Securities held to maturity, Wtd-Avg Yield	1.14%	1.05%

Securities_Held_to_Maturity_an9

Securities Held to Maturity and Available for Sale - Additional Information (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Investments Debt And Equity Securities [Abstract]	'	'
Securities available for sale, net	$1,016	$1,000
Shares owned in an intermediate bond fund	91,210	90,000

Loans_Receivable_Major_Classif

Loans Receivable - Major Classification of Loans Receivable (Detail) (USD $)	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified	Loans		Loans
Financing Receivable, Recorded Investment [Line Items]	'	'	'	'	'	'
Loans receivable, gross, # of Loans	578	'	568	'	'	'
Loans receivable, gross, Amount	$1,104,100	'	$1,111,063	'	'	'
Deferred loan fees	-3,823	'	-3,597	'	'	'
Loans receivable, net of deferred fees	1,100,277	'	1,107,466	'	'	'
Allowance for loan losses	-26,777	-26,455	-28,103	-28,382	-28,844	-30,415
Loans receivable, net	1,073,500	'	1,079,363	'	'	'
Loans Secured by Real Estate [Member]	'	'	'	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'	'	'	'
Loans receivable, gross, # of Loans	545	'	538	'	'	'
Loans receivable, gross, Amount	1,102,623	'	1,109,755	'	'	'
All Other Loans [Member]	'	'	'	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'	'	'	'
Loans receivable, gross, # of Loans	33	'	30	'	'	'
Loans receivable, gross, Amount	1,477	'	1,308	'	'	'
Commercial Real Estate [Member] | Loans Secured by Real Estate [Member]	'	'	'	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'	'	'	'
Loans receivable, gross, # of Loans	383	'	376	'	'	'
Loans receivable, gross, Amount	817,572	'	852,213	'	'	'
Multifamily [Member] | Loans Secured by Real Estate [Member]	'	'	'	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'	'	'	'
Loans receivable, gross, # of Loans	139	'	142	'	'	'
Loans receivable, gross, Amount	210,508	'	208,699	'	'	'
One to Four Family [Member] | Loans Secured by Real Estate [Member]	'	'	'	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'	'	'	'
Loans receivable, gross, # of Loans	19	'	13	'	'	'
Loans receivable, gross, Amount	68,662	'	41,676	'	'	'
Land Loans [Member] | Loans Secured by Real Estate [Member]	'	'	'	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'	'	'	'
Loans receivable, gross, # of Loans	4	'	7	'	'	'
Loans receivable, gross, Amount	5,881	'	7,167	'	'	'
Business Loans [Member] | All Other Loans [Member]	'	'	'	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'	'	'	'
Loans receivable, gross, # of Loans	19	'	18	'	'	'
Loans receivable, gross, Amount	1,130	'	949	'	'	'
Consumer Loans [Member] | All Other Loans [Member]	'	'	'	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'	'	'	'
Loans receivable, gross, # of Loans	14	'	12	'	'	'
Loans receivable, gross, Amount	$347	'	$359	'	'	'

Loans_Receivable_Additional_In

Loans Receivable - Additional Information (Detail) (USD $)	9 Months Ended					9 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012
	Debt	Loans		Nonaccrual Loans [Member]	Nonaccrual Loans [Member]	Accruing Loans [Member]	Accruing Loans [Member]
		Debt				Loans	Loans
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'	'	'	'	'	'
Total loans	'	'	'	$39,500,000	$45,900,000	'	'
Troubled debt restructured loans	'	'	'	'	'	11,400,000	20,100,000
90 days past due and still accruing interest loan	18,917,000	'	10,042,000	'	'	18,400,000	4,400,000
Number of loans, 90 days past due and still accruing	'	'	'	'	'	7	2
Restructured loans	'	0	'	'	'	'	'
TDR defaulted	1	0	'	'	'	'	'
Amount of TDR defaulted	3,000,000	'	'	'	'	'	'
TDR matured	$1,900,000	'	'	'	'	'	'

Loans_Receivable_Summary_of_Im

Loans Receivable - Summary of Impaired Loans (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Loans	Loans
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	$50,898	$65,973
Specific Valuation Allowance	4,757	5,888
Total Unpaid Principal	58,339	74,414
# of Loans	14	23
NY [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	8,779	21,934
FL [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	27,387	39,570
NJ [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	500	1,383
GA [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	8,695	'
CT [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	2,735	'
OH [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	1,000	1,000
SD [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	1,802	2,086
Retail [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	21,519	21,842
Specific Valuation Allowance	1,661	1,966
Total Unpaid Principal	28,446	27,596
# of Loans	7	6
Retail [Member] | NY [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	8,779	11,837
Retail [Member] | FL [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	9,005	9,005
Retail [Member] | NJ [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Retail [Member] | GA [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Retail [Member] | CT [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	2,735	'
Retail [Member] | OH [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	1,000	1,000
Retail [Member] | SD [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Office Building [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	23,937	18,871
Specific Valuation Allowance	1,977	583
Total Unpaid Principal	24,451	19,621
# of Loans	3	3
Office Building [Member] | NY [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Office Building [Member] | FL [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	15,242	17,988
Office Building [Member] | NJ [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	883
Office Building [Member] | GA [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	8,695	'
Office Building [Member] | CT [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Office Building [Member] | OH [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Office Building [Member] | SD [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Mixed Use [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	500	9,132
Specific Valuation Allowance	25	1,248
Total Unpaid Principal	500	9,421
# of Loans	1	4
Mixed Use [Member] | NY [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	8,632
Mixed Use [Member] | FL [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Mixed Use [Member] | NJ [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	500	500
Mixed Use [Member] | GA [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Mixed Use [Member] | CT [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Mixed Use [Member] | OH [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Mixed Use [Member] | SD [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Warehouse [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	950
Specific Valuation Allowance	'	28
Total Unpaid Principal	'	950
# of Loans	'	1
Warehouse [Member] | NY [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	950
Warehouse [Member] | FL [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Warehouse [Member] | NJ [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Warehouse [Member] | GA [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Warehouse [Member] | CT [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Warehouse [Member] | OH [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Warehouse [Member] | SD [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Multi Family [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	3,140	12,577
Specific Valuation Allowance	596	1,542
Total Unpaid Principal	3,140	14,225
# of Loans	2	6
Multi Family [Member] | NY [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Multi Family [Member] | FL [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	3,140	12,577
Multi Family [Member] | NJ [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Multi Family [Member] | GA [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Multi Family [Member] | CT [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Multi Family [Member] | OH [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Multi Family [Member] | SD [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Land [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	1,802	2,601
Specific Valuation Allowance	498	521
Total Unpaid Principal	1,802	2,601
# of Loans	1	3
Land [Member] | NY [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	515
Land [Member] | FL [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Land [Member] | NJ [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Land [Member] | GA [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Land [Member] | CT [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Land [Member] | OH [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	'	'
Land [Member] | SD [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Recorded Investment by State	$1,802	$2,086

Loans_Receivable_Other_Informa

Loans Receivable - Other Information Related to Impaired Loans (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Nonaccrual Loans [Member]	'	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'	'
Average recorded investment in loans	$39,159	$49,788	$41,039	$53,809
Total cash basis interest income recognized on nonaccrual loans	521	633	1,729	2,055
TDR Loans [Member]	'	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'	'
Average recorded investment in loans	11,423	14,380	14,482	10,341
Total interest income recognized on accruing TDR loans under modified terms	$152	$233	$581	$493

Loans_Receivable_Age_Analysis_

Loans Receivable - Age Analysis of Loan Portfolio By Segment (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	$1,104,100	$1,111,063
Current	1,081,918	1,085,524
Past Due 31-59 Days	'	15,497
Past Due 60-89 Days	3,265	'
Past Due 90 or more Days	18,917	10,042
Total Past Due	22,182	25,539
Total Classified Nonaccrual	39,517	45,898
Accruing Loans [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	1,064,583	1,065,165
Current	1,042,915	1,045,277
Past Due 31-59 Days	'	15,497
Past Due 60-89 Days	3,265	'
Past Due 90 or more Days	18,403	4,391
Total Past Due	21,668	19,888
Total Classified Nonaccrual	'	'
Nonaccrual Loans [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	39,517	45,898
Current	39,003	40,247
Past Due 31-59 Days	'	'
Past Due 60-89 Days	'	'
Past Due 90 or more Days	514	5,651
Total Past Due	514	5,651
Total Classified Nonaccrual	39,517	45,898
Commercial Real Estate [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	817,572	852,213
Commercial Real Estate [Member] | Accruing Loans [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	780,338	816,357
Current	758,670	799,130
Past Due 31-59 Days	'	12,836
Past Due 60-89 Days	3,265	'
Past Due 90 or more Days	18,403	4,391
Total Past Due	21,668	17,227
Total Classified Nonaccrual	'	'
Commercial Real Estate [Member] | Nonaccrual Loans [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	37,234	35,856
Current	36,720	32,701
Past Due 31-59 Days	'	'
Past Due 60-89 Days	'	'
Past Due 90 or more Days	514	3,155
Total Past Due	514	3,155
Total Classified Nonaccrual	37,234	35,856
Multi Family [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	210,508	208,699
Multi Family [Member] | Accruing Loans [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	208,225	198,942
Current	208,225	198,942
Past Due 31-59 Days	'	'
Past Due 60-89 Days	'	'
Past Due 90 or more Days	'	'
Total Past Due	'	'
Total Classified Nonaccrual	'	'
Multi Family [Member] | Nonaccrual Loans [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	2,283	9,757
Current	2,283	7,261
Past Due 31-59 Days	'	'
Past Due 60-89 Days	'	'
Past Due 90 or more Days	'	2,496
Total Past Due	'	2,496
Total Classified Nonaccrual	2,283	9,757
One to Four Family [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	68,662	41,676
One to Four Family [Member] | Accruing Loans [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	68,662	41,676
Current	68,662	41,676
Past Due 31-59 Days	'	'
Past Due 60-89 Days	'	'
Past Due 90 or more Days	'	'
Total Past Due	'	'
Total Classified Nonaccrual	'	'
Land [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	5,881	7,167
Land [Member] | Accruing Loans [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	5,881	6,882
Current	5,881	4,221
Past Due 31-59 Days	'	2,661
Past Due 60-89 Days	'	'
Past Due 90 or more Days	'	'
Total Past Due	'	2,661
Total Classified Nonaccrual	'	'
Land [Member] | Nonaccrual Loans [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	'	285
Current	'	285
Past Due 31-59 Days	'	'
Past Due 60-89 Days	'	'
Past Due 90 or more Days	'	'
Total Past Due	'	'
Total Classified Nonaccrual	'	285
All Other [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	1,477	1,308
All Other [Member] | Accruing Loans [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Total portfolio	1,477	1,308
Current	1,477	1,308
Past Due 31-59 Days	'	'
Past Due 60-89 Days	'	'
Past Due 90 or more Days	'	'
Total Past Due	'	'
Total Classified Nonaccrual	'	'

Loans_Receivable_Age_Analysis_1

Loans Receivable - Age Analysis of Loan Portfolio By Segment (Parenthetical) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Mortgage Loans on Real Estate [Line Items]	'	'
Current	$1,081,918	$1,085,524
Nonaccrual Loans [Member]	'	'
Mortgage Loans on Real Estate [Line Items]	'	'
Current	$35,800	$36,300

Loans_Receivable_Information_R

Loans Receivable - Information Regarding Credit Quality of Loan Portfolio (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	$1,104,100	$1,111,063
Allocation of allowance for loan losses	26,777	28,103
Commercial Real Estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	817,572	852,213
Multi Family [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	210,508	208,699
One to Four Family [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	68,662	41,676
Land [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	5,881	7,167
All Other [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	1,477	1,308
Pass [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	1,022,445	1,016,424
Allocation of allowance for loan losses	20,626	20,037
Pass [Member] | Commercial Real Estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	743,233	775,136
Pass [Member] | Multi Family [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	204,994	193,738
Pass [Member] | One to Four Family [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	68,662	41,676
Pass [Member] | Land [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	4,079	4,566
Pass [Member] | All Other [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	1,477	1,308
Special Mention [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	17,557	19,425
Allocation of allowance for loan losses	410	443
Special Mention [Member] | Commercial Real Estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	15,183	17,041
Special Mention [Member] | Multi Family [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	2,374	2,384
Substandard [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	64,098	75,214
Allocation of allowance for loan losses	5,741	7,623
Substandard [Member] | Commercial Real Estate [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	59,156	60,036
Substandard [Member] | Multi Family [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	3,140	12,577
Substandard [Member] | Land [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total loans	$1,802	$2,601

Loans_Receivable_Information_R1

Loans Receivable - Information Regarding Credit Quality of Loan Portfolio (Parenthetical) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
	SecurityLoan
Financing Receivable, Recorded Investment [Line Items]	'	'
Total Financing Receivable by TDRs	$47,149	$56,367
Number of rated pass accruing TDR	1	'
Nonaccrual Loans [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total Financing Receivable by TDRs	39,500	45,900
Accruing Loans [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total Financing Receivable by TDRs	6,000	20,100
All Other [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total Financing Receivable by TDRs	18,600	9,200
Pass [Member] | Accruing Loans One [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Total Financing Receivable by TDRs	$5,400	'

Loans_Receivable_Geographic_Di

Loans Receivable - Geographic Distribution of Loan Portfolio (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	$1,104,100	$1,111,063
Total Loan Receivable, % of Total	100.00%	100.00%
NY [Member]	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	667,265	717,141
Total Loan Receivable, % of Total	60.00%	64.50%
FL [Member]	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	314,274	286,619
Total Loan Receivable, % of Total	29.00%	25.80%
NJ [Member]	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	18,125	26,425
Total Loan Receivable, % of Total	1.60%	2.40%
NORTH CAROLINA	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	17,746	14,256
Total Loan Receivable, % of Total	1.60%	1.30%
PENNSYLVANIA	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	17,022	10,270
Total Loan Receivable, % of Total	1.50%	0.90%
GA [Member]	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	16,246	11,752
Total Loan Receivable, % of Total	1.50%	1.10%
VIRGINIA	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	11,560	11,758
Total Loan Receivable, % of Total	1.00%	1.10%
KENTUCKY	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	10,619	7,512
Total Loan Receivable, % of Total	1.00%	0.70%
SOUTH CAROLINA	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	9,272	5,853
Total Loan Receivable, % of Total	0.80%	0.50%
CT [Member]	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	8,482	11,216
Total Loan Receivable, % of Total	0.80%	1.00%
TN [Member]	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	5,626	770
Total Loan Receivable, % of Total	0.50%	0.00%
OH [Member]	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	2,236	2,260
Total Loan Receivable, % of Total	0.20%	0.20%
SD [Member]	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	1,802	2,086
Total Loan Receivable, % of Total	0.20%	0.20%
All Other States [Member]	'	'
Noncancelable Obligations Future Minimum Payments Due [Line Items]	'	'
Total loans	$3,825	$3,145
Total Loan Receivable, % of Total	0.30%	0.30%

Loans_Receivable_Information_R2

Loans Receivable - Information Regarding Loans Restructured (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012
	SecurityLoan	Commercial Real Estate [Member]	Land [Member]
		SecurityLoan	SecurityLoan
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'	'
Loans restructured, Number of Loans	1	2	2
Loans restructured, Pre-Modification Recorded Investment	'	$9,159	$520
Loans restructured, Post-Modification Recorded Investment	'	$9,159	$520

Loans_Receivable_Distribution_

Loans Receivable - Distribution of TDRs by Accruing Versus Non-Accruing, by Segment and by Geographic (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'
Total Financing Receivable by TDRs	$47,149	$56,367
NY [Member]	'	'
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'
Total Financing Receivable by TDRs	8,265	18,478
FL [Member]	'	'
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'
Total Financing Receivable by TDRs	27,387	33,920
NJ [Member]	'	'
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'
Total Financing Receivable by TDRs	'	883
GA [Member]	'	'
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'
Total Financing Receivable by TDRs	8,695	'
OH [Member]	'	'
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'
Total Financing Receivable by TDRs	1,000	1,000
SD [Member]	'	'
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'
Total Financing Receivable by TDRs	1,802	2,086
Commercial Real Estate [Member]	'	'
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'
Total Financing Receivable by TDRs	42,207	43,685
Multi Family [Member]	'	'
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'
Total Financing Receivable by TDRs	3,140	10,081
Land [Member]	'	'
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'
Total Financing Receivable by TDRs	1,802	2,601
Non-accruing [Member] | Performing [Member]	'	'
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'
Total Financing Receivable by TDRs	35,768	36,291
Accruing [Member] | Performing [Member]	'	'
Financing Receivable Modifications Number Of Contracts [Line Items]	'	'
Total Financing Receivable by TDRs	$11,381	$20,076

Allowance_for_Loan_Losses_Allo

Allowance for Loan Losses - Allowance for Loan Losses by Loan Type (Detail) (USD $)	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011
					Commercial Real Estate [Member]	Commercial Real Estate [Member]	Commercial Real Estate [Member]	Commercial Real Estate [Member]	Multifamily [Member]	Multifamily [Member]	Multifamily [Member]	Multifamily [Member]	One to Four Family [Member]	One to Four Family [Member]	One to Four Family [Member]	One to Four Family [Member]	Land [Member]	Land [Member]	Land [Member]	Land [Member]	All Other [Member]	All Other [Member]	All Other [Member]	All Other [Member]	All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'
Balance at beginning of period	$26,455	$28,844	$28,103	$30,415	$17,596	$18,343	$19,051	$19,156	$5,098	$8,480	$6,881	$8,848	$2,795	$502	$1,120	$332	$956	$1,509	$1,043	$2,069	$10	$8	$10	$10	$10
Loan chargeoffs	'	-548	-1,938	-2,476	'	-548	-1,932	-2,215	'	'	-6	-261	'	'	'	'	'	'	'	'	'	'	'	'	'
Loan recoveries	72	86	2,112	443	67	63	947	383	5	23	682	60	'	'	'	'	'	'	483	'	'	'	'	'	'
Provision (credit) for loan losses	250	'	-1,500	'	-175	468	-578	1,002	212	-381	-2,242	-525	229	250	1,904	420	-15	-337	-585	-897	-1	1	'	'	'
Balance at end of period	$26,777	$28,382	$26,777	$28,382	$17,488	$18,326	$17,488	$18,326	$5,315	$8,122	$5,315	$8,122	$3,024	$752	$3,024	$752	$941	$1,172	$941	$1,172	$9	$9	$10	$10	$10

Allowance_for_Loan_Losses_Loan

Allowance for Loan Losses - Loans Receivable by Segment and Impairment Evaluation and Allowance for Loan Losses (Detail) (USD $)	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Loans:	'	'	'	'	'	'
Individually evaluated for impairment	$50,898	'	$65,973	'	'	'
Collectively evaluated for impairment	1,053,202	'	1,045,090	'	'	'
Total loans	1,104,100	'	1,111,063	'	'	'
Allowance for loan losses:	'	'	'	'	'	'
Individually evaluated for impairment	4,757	'	5,888	'	'	'
Collectively evaluated for impairment	22,020	'	22,215	'	'	'
Total allowance for loan losses	26,777	26,455	28,103	28,382	28,844	30,415
Commercial Real Estate [Member]	'	'	'	'	'	'
Loans:	'	'	'	'	'	'
Individually evaluated for impairment	45,955	'	50,795	'	'	'
Collectively evaluated for impairment	771,617	'	801,418	'	'	'
Total loans	817,572	'	852,213	'	'	'
Allowance for loan losses:	'	'	'	'	'	'
Individually evaluated for impairment	3,663	'	3,825	'	'	'
Collectively evaluated for impairment	13,825	'	15,226	'	'	'
Total allowance for loan losses	17,488	'	19,051	'	'	'
Multifamily [Member]	'	'	'	'	'	'
Loans:	'	'	'	'	'	'
Individually evaluated for impairment	3,141	'	12,577	'	'	'
Collectively evaluated for impairment	207,367	'	196,122	'	'	'
Total loans	210,508	'	208,699	'	'	'
Allowance for loan losses:	'	'	'	'	'	'
Individually evaluated for impairment	596	'	1,542	'	'	'
Collectively evaluated for impairment	4,719	'	5,339	'	'	'
Total allowance for loan losses	5,315	'	6,881	'	'	'
One to Four Family [Member]	'	'	'	'	'	'
Loans:	'	'	'	'	'	'
Collectively evaluated for impairment	68,662	'	41,676	'	'	'
Total loans	68,662	'	41,676	'	'	'
Allowance for loan losses:	'	'	'	'	'	'
Collectively evaluated for impairment	3,024	'	1,120	'	'	'
Total allowance for loan losses	3,024	'	1,120	'	'	'
Land [Member]	'	'	'	'	'	'
Loans:	'	'	'	'	'	'
Individually evaluated for impairment	1,802	'	2,601	'	'	'
Collectively evaluated for impairment	4,079	'	4,566	'	'	'
Total loans	5,881	'	7,167	'	'	'
Allowance for loan losses:	'	'	'	'	'	'
Individually evaluated for impairment	498	'	521	'	'	'
Collectively evaluated for impairment	443	'	522	'	'	'
Total allowance for loan losses	941	'	1,043	'	'	'
All Other [Member]	'	'	'	'	'	'
Loans:	'	'	'	'	'	'
Collectively evaluated for impairment	1,477	'	1,308	'	'	'
Total loans	1,477	'	1,308	'	'	'
Allowance for loan losses:	'	'	'	'	'	'
Collectively evaluated for impairment	9	'	8	'	'	'
Total allowance for loan losses	$9	'	$8	'	'	'

Foreclosed_Real_Estate_and_Val2

Foreclosed Real Estate and Valuation Allowance for Real Estate Losses - Summary of Real Estate Acquired through Foreclosure by Property Type (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Property	Property
Real Estate Properties [Line Items]	'	'
# of Properties	4	6
Amount	$12,019	$15,923
Commercial Real Estate [Member]	'	'
Real Estate Properties [Line Items]	'	'
# of Properties	3	2
Amount	5,334	2,790
Multifamily [Member]	'	'
Real Estate Properties [Line Items]	'	'
# of Properties	1	3
Amount	6,685	12,000
Land [Member]	'	'
Real Estate Properties [Line Items]	'	'
# of Properties	'	1
Amount	'	$1,133

Foreclosed_Real_Estate_and_Val3

Foreclosed Real Estate and Valuation Allowance for Real Estate Losses - Summary of Activity in Valuation Allowance for Real Estate Losses (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Real Estate [Abstract]	'	'	'	'
Valuation allowance at beginning of period	$6,044	$7,945	$5,339	$6,037
Provision for real estate losses	250	1,025	955	2,933
Real estate chargeoffs	-4,171	-3,642	-4,171	-3,642
Valuation allowance at end of period	$2,123	$5,328	$2,123	$5,328

Deposits_Scheduled_Maturities_

Deposits - Scheduled Maturities of Certificates of Deposits (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Time Deposits By Maturity [Abstract]	'	'
Within one year, Amount	$434,055	$519,236
Over one to two years, Amount	175,921	181,698
Over two to three years, Amount	108,008	89,049
Over three to four years, Amount	105,813	60,119
Over four years, Amount	73,615	86,776
Total certificates of deposit, Amount	$897,412	$936,878
Within one year, Wtd-Avg Stated Rate	2.91%	2.92%
Over one to two years, Wtd-Avg Stated Rate	2.02%	2.79%
Over two to three years, Wtd-Avg Stated Rate	2.25%	2.74%
Over three to four years, Wtd-Avg Stated Rate	2.60%	3.02%
Over four years, Wtd-Avg Stated Rate	2.02%	2.93%
Total certificates of deposit, Wtd-Avg Stated Rate	2.54%	2.89%

Deposits_Additional_Informatio

Deposits - Additional Information (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Assets Sold under Agreements to Repurchase [Line Items]	'	'
CDs of $100,000 or more	$467,000,000	$463,000,000
Brokered certificate deposits amount	85,000,000	78,000,000
Due within one year	434,055,000	519,236,000
Due over one to two years	175,921,000	181,698,000
Due over two to three years	108,008,000	89,049,000
Due over three to four years	105,813,000	60,119,000
Due thereafter	73,615,000	86,776,000
CDs of $100,000 or more [Member]	'	'
Assets Sold under Agreements to Repurchase [Line Items]	'	'
Due within one year	220,000,000	'
Due over one to two years	77,000,000	'
Due over two to three years	60,000,000	'
Due over three to four years	64,000,000	'
Due thereafter	46,000,000	'
Brokered CDs [Member]	'	'
Assets Sold under Agreements to Repurchase [Line Items]	'	'
Due within one year	32,000,000	'
Due over one to two years	5,000,000	'
Due over two to three years	8,000,000	'
Due over three to four years	24,000,000	'
Due thereafter	$16,000,000	'
Brokered certificates deposits weighted average rate	3.48%	'

Lines_of_Credit_Additional_Inf

Lines of Credit - Additional Information (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]	'	'
Borrowings	'	$7,000,000
Federal Home Loan Bank of New York and Federal Reserve Bank of New York [Member]	'	'
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]	'	'
Unsecured credit lines	24,000,000	'
Additional total borrowings from FHLB and FRB	441,000,000	'
Borrowings	$0	'

Lines_of_Credit_Summary_of_Cer

Lines of Credit - Summary of Certain Information Regarding FHLB Advances (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Debt Disclosure [Abstract]	'	'	'	'
Balance at period end	'	$7,000	'	$7,000
Maximum amount outstanding at any month end for the period	'	10,500	'	13,500
Average outstanding balance for the period	'	$9,511	'	$11,215
Weighted-average interest rate paid for the period	'	4.31%	'	4.26%
Weighted-average interest rate at period end	'	4.22%	'	4.22%

Subordinated_Debentures_Capita2

Subordinated Debentures - Capital Securities - Summary of Capital Securities Outstanding (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Accrued Interest Payable	$463	$6,228
Capital Securities II [Member]	'	'
Debt Instrument [Line Items]	'	'
Principal	15,464	15,464
Accrued Interest Payable	147	1,661
Interest Rate	3.20%	3.26%
Capital Securities III [Member]	'	'
Debt Instrument [Line Items]	'	'
Principal	15,464	15,464
Accrued Interest Payable	139	1,577
Interest Rate	3.04%	3.10%
Capital Securities IV [Member]	'	'
Debt Instrument [Line Items]	'	'
Principal	15,464	15,464
Accrued Interest Payable	119	1,370
Interest Rate	2.65%	2.71%
Capital Securities V [Member]	'	'
Debt Instrument [Line Items]	'	'
Principal	10,310	10,310
Accrued Interest Payable	58	1,620
Interest Rate	1.90%	1.96%
Capital Securities [Member]	'	'
Debt Instrument [Line Items]	'	'
Principal	56,702	56,702
Accrued Interest Payable	$463	$6,228

Subordinated_Debentures_Capita3

Subordinated Debentures - Capital Securities - Additional Information (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Debt Instrument [Line Items]	'
Capital Securities, net of IBC's capital contributions	$1.70
IBC's capital contributions	55
Unamortized balance of issuance costs	0.7
Capital Securities V [Member]	'
Debt Instrument [Line Items]	'
Capital Securities issuance costs	$0
Frequency of periodic interest payment	'Quarterly
Debt instrument interest rate	1.65%
Debt instrument, interest rate terms	'1.65% over 3 month libor
Capital Securities II [Member]	'
Debt Instrument [Line Items]	'
Frequency of periodic interest payment	'Quarterly
Debt instrument interest rate	2.95%
Debt instrument, interest rate terms	'2.95% over 3 month libor
Capital Securities III [Member]	'
Debt Instrument [Line Items]	'
Frequency of periodic interest payment	'Quarterly
Debt instrument interest rate	2.79%
Debt instrument, interest rate terms	'2.79% over 3 month libor
Capital Securities IV [Member]	'
Debt Instrument [Line Items]	'
Frequency of periodic interest payment	'Quarterly
Debt instrument interest rate	2.40%
Debt instrument, interest rate terms	'2.40% over 3 month libor
Junior Subordinated Debentures [Member]	'
Debt Instrument [Line Items]	'
Debt instrument, limit on extension periods	20
Debt instrument, interest payment, maximum extension period	'5 years
Capital Securities, mandatory maturity period	'90 days

Stockholders_Equity_and_Redemp1

Stockholders' Equity and Redemption of Preferred Stock - Additional Information (Detail) (USD $)	1 Months Ended			9 Months Ended
In Millions, except Share data, unless otherwise specified	Aug. 15, 2013	Jun. 24, 2013	Jun. 06, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
Equity [Abstract]	'	'	'	'	'	'
Capital stock, shares authorized to issue	'	'	'	62,300,000	'	'
Common stock, shares authorized	'	'	'	62,000,000	62,000,000	'
Preferred stock, shares authorized	'	'	'	300,000	300,000	'
Preferred stock issued	'	'	'	25,000	25,000	25,000
Duration of Warrant	'	'	'	'10 years	'	'
Number of shares to be exercised upon warrants	'	'	'	691,882	'	'
Conversion price for warrants	'	'	'	5.42	'	'
Treasury auctioned Shares	'	'	25,000	'	'	'
Number of Preferred stock	'	'	6,250	'	'	'
Purchase of Preferred stock shares by third parties	'	'	18,750	'	'	'
Closing price of the auctioned shares	'	'	$970	'	'	'
Number of Preferred stock repurchased	'	6,250	'	'	'	'
Rate of Repurchase of shares	'	$6.10	'	'	'	'
Additional accrued and unpaid dividends	'	1.2	'	'	'	'
Total shares repurchase	'	7.3	'	'	'	'
Preferred Stock outstanding redeemed	18,750	'	'	'	'	'
Effective date of the planned redemption	15-Aug-13	'	'	'	'	'
Purchase price of shares	$1,000	'	'	'	'	'
Total expected cost to redeem shares	22.6	'	'	'	'	'
Preferred dividends	$3.90	'	'	'	'	'

Common_Stock_Warrant_Options_a2

Common Stock Warrant, Options and Restricted Common Stock - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	$231,000	$309,000	$731,000	$885,000
Pre-tax, stock-based compensation cost related to all nonvested awards of options and restricted stock not yet recognized	1,500,000	'	1,500,000	'
Options and restricted stock not yet recognized and will be recognized over a weighted-average period	'	'	'2 years	'
Net tax benefit	'	'	$150,000	$0
Long Term Incentive Plan [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Maximum number of shares of common stock that may be awarded	2,250,000	'	2,250,000	'
Common stock were available for award	777,993	'	777,993	'
Issuance of common stock option	'	'	0	0

Common_Stock_Warrant_Options_a3

Common Stock Warrant, Options and Restricted Common Stock - Summary of Selected Information Regarding Restricted Common Stock Awards made under Plan (Detail) (USD $)	9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Beginning Outstanding	1,078,122
Forfeited/expired	-8,700
Options exercised	-14,967
Ending Outstanding	1,054,455
Vested and exercisable	96.00%
Wtd-avg contractual remaining term (in years)	'5 years 4 months 24 days
Intrinsic value at September 30, 2013	$2,377
Wtd-Avg Exercise Price, Beginning Outstanding	$6.63
Wtd-Avg Exercise Price, Forfeited/expired	$5.52
Wtd-Avg Exercise Price, Options exercised	$3.59
Wtd-Avg Exercise Price, Ending Outstanding	$6.68
Exercise Price Per Warrant/Option $5.42 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$5.42
Beginning Outstanding	691,882
Ending Outstanding	691,882
Expiration date	23-Dec-18
Vested and exercisable	100.00%
Wtd-avg contractual remaining term (in years)	'5 years 2 months 12 days
Intrinsic value at September 30, 2013	1,737
Exercise Price Per Warrant/Option $17.10 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$17.10
Beginning Outstanding	116,640
Forfeited/expired	-1,200
Ending Outstanding	115,440
Expiration date	13-Dec-17
Vested and exercisable	100.00%
Wtd-avg contractual remaining term (in years)	'4 years 2 months 12 days
Exercise Price Per Warrant/Option $7.50 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$7.50
Beginning Outstanding	120,190
Forfeited/expired	-1,200
Ending Outstanding	118,990
Expiration date	11-Dec-18
Vested and exercisable	100.00%
Wtd-avg contractual remaining term (in years)	'5 years 2 months 12 days
Intrinsic value at September 30, 2013	51
Exercise Price Per Warrant/Option $4.02 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$4.02
Beginning Outstanding	68,910
Forfeited/expired	-1,100
Options exercised	-9,600
Ending Outstanding	58,210
Expiration date	10-Dec-19
Vested and exercisable	100.00%
Wtd-avg contractual remaining term (in years)	'6 years 2 months 12 days
Intrinsic value at September 30, 2013	228
Exercise Price Per Warrant/Option $3.00 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$3
Beginning Outstanding	38,200
Forfeited/expired	-1,900
Options exercised	-3,200
Ending Outstanding	33,100
Expiration date	9-Dec-20
Vested and exercisable	67.00%
Wtd-avg contractual remaining term (in years)	'7 years 2 months 12 days
Intrinsic value at September 30, 2013	163
Exercise Price Per Warrant/Option $2.55 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$2.55
Beginning Outstanding	42,300
Forfeited/expired	-3,300
Options exercised	-2,167
Ending Outstanding	36,833
Expiration date	8-Dec-21
Vested and exercisable	33.00%
Wtd-avg contractual remaining term (in years)	'8 years 2 months 12 days
Intrinsic value at September 30, 2013	$198

Common_Stock_Warrant_Options_a4

Common Stock Warrant, Options and Restricted Common Stock - Summary of Selected Information Regarding Restricted Common Stock Awards made under Plan (Parenthetical) (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Vested and exercisable	96.00%
Calculated intrinsic value	$7.93
Exercise Price Per Warrant/Option $3.00 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$3
Vested and exercisable	67.00%
Exercise Price Per Warrant/Option $3.00 [Member] | Vest and Become Exercisable on December 9, 2013 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$3
Vested and exercisable	100.00%
Exercise Price Per Warrant/Option $2.55 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$2.55
Vested and exercisable	33.00%
Exercise Price Per Warrant/Option $2.55 [Member] | Vest and Become Exercisable on December 8, 2013 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$2.55
Vested and exercisable	33.33%
Exercise Price Per Warrant/Option $2.55 [Member] | Vest and Become Exercisable on December 8, 2014 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$2.55
Vested and exercisable	33.33%

Common_Stock_Warrant_Options_a5

Common Stock Warrant, Options and Restricted Common Stock - Summary of Outstanding Common Stock Warrant and Options (Detail) (USD $)	9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Grant date of award, Stock Grant	24-Jan-13	19-Jan-12
Total restricted shares of stock awarded	330,700	465,400
Estimated fair value per share awarded	$4.50	$2.90
Total estimated fair value of award	$1,488	$1,350
Awards scheduled to vest, Stock Grant	330,700	465,400
January 2013 [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Awards scheduled to vest, Stock Grant	'	256,800
January 2014 [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Awards scheduled to vest, Stock Grant	49,566	133,455
January 2015 [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Awards scheduled to vest, Stock Grant	170,888	75,145
January 2016 [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Awards scheduled to vest, Stock Grant	110,246	'

Common_Stock_Warrant_Options_a6

Common Stock Warrant, Options and Restricted Common Stock - Summary of Outstanding Common Stock Warrant and Options (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
	Installment	Installment
	Executives	Executives
Restricted Common Stock [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Shares Awarded	330,700	'
Executive Officers [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Number of participants	5	5
Number of installments	2	2
Restricted stock awards vesting in second anniversary of the grant	66.67%	66.67%
Restricted stock awards vesting in third anniversary of the grant	33.33%	33.33%
Executive Officers [Member] | Restricted Common Stock [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Shares Awarded	182,000	175,000
Non-employee Directors [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Number of participants	8	6
Restricted stock awards vesting in second anniversary of the grant	33.33%	'
Restricted stock awards vesting in third anniversary of the grant	33.33%	'
Restricted stock awards vesting in first anniversary of the grant	33.33%	100.00%
Non-employee Directors [Member] | Restricted Common Stock [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Shares Awarded	80,000	240,000
Other Officers and Employees [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Number of installments	3	3
Restricted stock awards vesting in second anniversary of the grant	33.33%	33.33%
Restricted stock awards vesting in third anniversary of the grant	33.33%	33.33%
Restricted stock awards vesting in first anniversary of the grant	33.33%	33.33%
Other Officers and Employees [Member] | Restricted Common Stock [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Shares Awarded	68,700	50,400

Common_Stock_Warrant_Options_a7

Common Stock Warrant, Options and Restricted Common Stock - Summary of Activity in IBCs Restricted Class A Common Stock (Detail) (Restricted Common Stock [Member], USD $)	9 Months Ended
	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Beginning Outstanding	782,300
Shares vested and no longer restricted	-256,600
Shares granted	330,700
Shares forfeited	-18,633
Ending Outstanding	837,767
Price Per Share $2.35 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Price Per Share	2.35
Beginning Outstanding	317,500
Shares forfeited	-7,100
Ending Outstanding	310,400
Price Per Share $2.90 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Price Per Share	2.9
Beginning Outstanding	464,800
Shares vested and no longer restricted	-256,600
Shares forfeited	-6,133
Ending Outstanding	202,067
Price Per Share $4.50 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Price Per Share	4.5
Shares granted	330,700
Shares forfeited	-5,400
Ending Outstanding	325,300

Common_Stock_Warrant_Options_a8

Common Stock Warrant, Options and Restricted Common Stock - Summary of Activity in IBCs Restricted Class A Common Stock (Parenthetical) (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Vested and exercisable	96.00%
Price Per Share $2.35 [Member] | Vest and Become Exercisable on December 9, 2013 [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$2.35
Vested and exercisable	100.00%
Price Per Share $2.35 [Member] | Restricted Common Stock [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$2.35
Price Per Share $2.90 [Member] | Restricted Common Stock [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$2.90
Restricted common stock will vest on date 1	130,200
Restricted common stock will vest on date 2	71,867
Price Per Share $4.50 [Member] | Restricted Common Stock [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Per Warrant/Option	$4.50
Restricted common stock will vest on date 1	47,767
Restricted common stock will vest on date 2	169,100
Restricted common stock will vest on date 3	108,433

Deferred_Tax_Asset_Additional_

Deferred Tax Asset - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Operating Loss Carryforwards [Line Items]	'	'
Total deferred tax asset	$21,774,000	$29,234,000
NOL carryforwards expiration year	'2030	'
Federal [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Unused net operating loss carryforward	2,000,000	'
State and Local [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Unused net operating loss carryforward	34,000,000	'
AMT Credit [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Unused net operating loss carryforward	$1,800,000	'

Earning_Per_Common_Share_Summa

Earning Per Common Share - Summary of Basic and Diluted Earnings Per Common Share (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Basic Earnings Per Common Share:	'	'	'	'
Net earnings available to common stockholders	$2,588,000	$2,225,000	$9,230,000	$7,347,000
Weighted-Average number of common shares outstanding	21,915,596	21,589,744	21,891,886	21,558,092
Basic earnings per common share	$0.12	$0.10	$0.42	$0.34
Diluted Earnings Per Common Share:	'	'	'	'
Net earnings available to common stockholders	$2,588,000	$2,225,000	$9,230,000	$7,347,000
Weighted-Average number of common shares outstanding:	'	'	'	'
Common shares outstanding	21,915,596	21,589,744	21,891,886	21,558,092
Potential dilutive shares resulting from exercise of warrants /options	135,866	978	81,064	276
Total average number of common shares outstanding used for dilution	22,051,462	21,590,722	21,972,950	21,558,368
Diluted earnings per common share	$0.12	$0.10	$0.42	$0.34

Earning_Per_Common_Share_Summa1

Earning Per Common Share - Summary of Basic and Diluted Earnings Per Common Share (Parenthetical) (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]	'	'	'	'
Outstanding options/warrants to purchase, shares	234,430	1,041,122	234,430	1,041,122

OffBalance_Sheet_Financial_Ins2

Off-Balance Sheet Financial Instruments - Additional Information (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Off Balance Sheet Financial Instruments [Abstract]	'	'
Standby letters of credit	$0	$0

OffBalance_Sheet_Financial_Ins3

Off-Balance Sheet Financial Instruments - Summary of Contractual Amounts of Off-Balance Sheet Financial Instruments (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]	'	'
Standby letters of credit	$31,349	$20,008
Commitments to Extend Credit [Member]	'	'
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]	'	'
Standby letters of credit	30,672	19,154
Unused Lines of Credit [Member]	'	'
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]	'	'
Standby letters of credit	$677	$854

Contingencies_Additional_Infor

Contingencies - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2013
			SecurityLoan
Loss Contingencies [Line Items]	'	'	'
Number of loans associated with recoveries of prior real estate expenses	'	'	1
INB [Member]	'	'	'
Loss Contingencies [Line Items]	'	'	'
Net Proceeds of loans	$0.10	$2.70	'
Recovery of prior loan charge offs	'	'	1.1
Recovery of prior real estate expenses	'	'	$1.60
Number of loans associated with recoveries of prior real estate expenses	'	'	2

Regulatory_Matters_and_Regulat2

Regulatory Matters and Regulatory Capital - Summary of Regulatory Capital and Related Ratios (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Tier 1 capital	$238,955	$249,465
Tier 2 capital	15,416	15,620
Total risk-based capital	254,371	265,085
Net risk-weighted assets for regulatory purposes	1,221,807	1,238,024
Average assets for regulatory purposes	1,568,881	1,696,410
Total capital to risk-weighted assets	20.82%	21.41%
Tier 1 capital to risk-weighted assets	19.56%	20.15%
Tier 1 capital to average assets	15.23%	14.71%
INB [Member]	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Tier 1 capital	234,166	244,081
Tier 2 capital	15,377	15,566
Total risk-based capital	249,543	259,647
Net risk-weighted assets for regulatory purposes	1,218,718	1,232,670
Average assets for regulatory purposes	$1,563,834	$1,690,329
Total capital to risk-weighted assets	20.48%	21.06%
Tier 1 capital to risk-weighted assets	19.21%	19.80%
Tier 1 capital to average assets	14.97%	14.44%

Regulatory_Matters_and_Regulat3

Regulatory Matters and Regulatory Capital - Summary of Regulatory Capital and Related Ratios (Parenthetical) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Banking And Thrift [Abstract]	'	'
Outstanding qualifying trust preferred securities	$55	$55

Regulatory_Matters_and_Regulat4

Regulatory Matters and Regulatory Capital - Capital Adequacy (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Total capital to risk-weighted assets, Actual Capital, Amount	$254,371	$265,085
Tier 1 capital to risk-weighted assets, Actual Capital, Amount	238,955	249,465
Tier 1 capital to average assets, Actual Capital, Amount	238,955	249,465
Total capital to risk-weighted assets, Actual Capital, Ratio	20.82%	21.41%
Tier 1 capital to risk-weighted assets, Actual Capital, Ratio	19.56%	20.15%
Tier 1 capital to average assets, Actual Capital, Ratio	15.23%	14.71%
Total capital to risk-weighted assets, Capital Requirements, Minimum Under Prompt Corrective Action Provisions, Amount	97,745	99,042
Tier 1 capital to risk-weighted assets, Capital Requirements, Minimum Under Prompt Corrective Action Provisions, Amount	48,872	49,521
Tier 1 capital to average assets, Capital Requirements, Minimum Under Prompt Corrective Action Provisions, Amount	62,755	67,856
Total capital to risk-weighted assets, Capital Requirements, Minimum Under Prompt Corrective Action Provisions, Ratio	8.00%	8.00%
Tier 1 capital to risk-weighted assets, Capital Requirements, Minimum Under Prompt Corrective Action Provisions, Ratio	4.00%	4.00%
Tier 1 capital to average assets, Capital Requirements, Minimum Under Prompt Corrective Action Provisions, Ratio	4.00%	4.00%
INB [Member]	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Total capital to risk-weighted assets, Actual Capital, Amount	249,543	259,647
Tier 1 capital to risk-weighted assets, Actual Capital, Amount	234,166	244,081
Tier 1 capital to average assets, Actual Capital, Amount	234,166	244,081
Total capital to risk-weighted assets, Actual Capital, Ratio	20.48%	21.06%
Tier 1 capital to risk-weighted assets, Actual Capital, Ratio	19.21%	19.80%
Tier 1 capital to average assets, Actual Capital, Ratio	14.97%	14.44%
Total capital to risk-weighted assets, Capital Requirements, Minimum Under Prompt Corrective Action Provisions, Amount	97,497	98,614
Tier 1 capital to risk-weighted assets, Capital Requirements, Minimum Under Prompt Corrective Action Provisions, Amount	48,749	49,307
Tier 1 capital to average assets, Capital Requirements, Minimum Under Prompt Corrective Action Provisions, Amount	62,553	67,613
Total capital to risk-weighted assets, Capital Requirements, Minimum Under Prompt Corrective Action Provisions, Ratio	8.00%	8.00%
Tier 1 capital to risk-weighted assets, Capital Requirements, Minimum Under Prompt Corrective Action Provisions, Ratio	4.00%	4.00%
Tier 1 capital to average assets, Capital Requirements, Minimum Under Prompt Corrective Action Provisions, Ratio	4.00%	4.00%
Total capital to risk-weighted assets, Capital Requirements, Minimum To Be "Well Capitalized" Under Prompt Corrective Action Provisions, Amount	121,872	123,267
Tier 1 capital to risk-weighted assets, Capital Requirements, Minimum To Be "Well Capitalized" Under Prompt Corrective Action Provisions, Amount	73,123	73,960
Tier 1 capital to average assets, Capital Requirements, Minimum To Be "Well Capitalized" Under Prompt Corrective Action Provisions, Amount	78,192	84,516
Total capital to risk-weighted assets, Capital Requirements, Minimum To Be "Well Capitalized" Under Prompt Corrective Action Provisions, Ratio	10.00%	10.00%
Tier 1 capital to risk-weighted assets, Capital Requirements, Minimum To Be "Well Capitalized" Under Prompt Corrective Action Provisions, Ratio	6.00%	6.00%
Tier 1 capital to average assets, Capital Requirements, Minimum To Be "Well Capitalized" Under Prompt Corrective Action Provisions, Ratio	5.00%	5.00%
Total capital to risk-weighted assets, Capital Requirements, Minimum Under Agreement With OCC, Amount	'	147,920
Tier 1 capital to risk-weighted assets, Capital Requirements, Minimum Under Agreement With OCC, Amount	'	123,267
Tier 1 capital to average assets, Capital Requirements, Minimum Under Agreement With OCC, Amount	'	$152,130
Total capital to risk-weighted assets, Capital Requirements, Minimum Under Agreement With OCC, Ratio	'	12.00%
Tier 1 capital to risk-weighted assets, Capital Requirements, Minimum Under Agreement With OCC, Ratio	'	10.00%
Tier 1 capital to average assets, Capital Requirements, Minimum Under Agreement With OCC, Ratio	'	9.00%

Regulatory_Matters_and_Regulat5

Regulatory Matters and Regulatory Capital - Capital Adequacy (Parenthetical) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Banking And Thrift [Abstract]	'	'
Outstanding qualifying trust preferred securities	$55	$55
Tier 1 proforma capital ratio	20.82%	'
Tier two proforma capital ratio	15.06%	'
Consolidated proforma capital ratio	11.73%	'

Regulatory_Matters_and_Regulat6

Regulatory Matters and Regulatory - Additional Information Regarding Capital Adequacy (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Total capital to risk-weighted assets, Actual Capital, Amount	$254,371	$265,085
Tier 1 capital to risk-weighted assets, Actual Capital, Amount	238,955	249,465
Tier 1 capital to average assets, Actual	238,955	'
Total capital to risk-weighted assets, Required	97,745	99,042
Tier 1 capital to risk-weighted assets, Required	48,872	49,521
Tier 1 capital to average assets, Required	62,755	67,856
Total capital to risk-weighted assets, Excess	156,626	'
Tier 1 capital to risk-weighted assets, Excess	190,083	'
Tier 1 capital to average assets, Excess	176,200	'
INB [Member]	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Total capital to risk-weighted assets, Actual Capital, Amount	249,543	259,647
Tier 1 capital to risk-weighted assets, Actual Capital, Amount	234,166	244,081
Tier 1 capital to average assets, Actual	234,166	'
Total capital to risk-weighted assets, Required	121,872	123,267
Tier 1 capital to risk-weighted assets, Required	73,123	73,960
Tier 1 capital to average assets, Required	78,192	84,516
Total capital to risk-weighted assets, Required	97,497	98,614
Tier 1 capital to risk-weighted assets, Required	48,749	49,307
Tier 1 capital to average assets, Required	62,553	67,613
Total capital to risk-weighted assets, Excess	127,671	'
Tier 1 capital to risk-weighted assets, Excess	161,043	'
Tier 1 capital to average assets, Excess	$155,974	'

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Securities available for sale, net	$1,016	$1,000
Fair Value, Inputs, Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Securities available for sale, net	1,000	1,000
Liabilities that were recorded at fair value	$0	$0

Fair_Value_Measurements_Assets

Fair Value Measurements - Assets Measured at Fair Value on a Nonrecurring Basis (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Accumulated Losses on Outstanding Balance	$18,712	'	$18,712	'	$23,164
Total Losses (Gains)	413	601	935	2,256	'
Impaired Securities [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Accumulated Losses on Outstanding Balance	5,197	'	5,197	'	4,233
Total Losses (Gains)	273	'	964	157	'
Foreclosure Real Estate [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Accumulated Losses on Outstanding Balance	2,123	'	2,123	'	5,339
Total Losses (Gains)	149	1,025	135	2,933	'
Impaired Loans [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Accumulated Losses on Outstanding Balance	11,392	'	11,392	'	13,592
Total Losses (Gains)	-9	-424	-164	-834	'
Impaired Loans [Member] | Commercial Real Estate [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Accumulated Losses on Outstanding Balance	10,294	'	10,294	'	9,979
Total Losses (Gains)	'	-254	823	-241	'
Impaired Loans [Member] | Multi Family [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Accumulated Losses on Outstanding Balance	598	'	598	'	3,092
Total Losses (Gains)	-7	-170	-964	-100	'
Impaired Loans [Member] | Land [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Accumulated Losses on Outstanding Balance	500	'	500	'	521
Total Losses (Gains)	-2	'	-23	-493	'
Level 3 [Member] | Impaired Securities [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Outstanding Carrying Value	2,604	'	2,604	'	3,721
Level 3 [Member] | Foreclosure Real Estate [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Outstanding Carrying Value	12,019	'	12,019	'	15,923
Level 3 [Member] | Impaired Loans [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Outstanding Carrying Value	50,898	'	50,898	'	65,973
Level 3 [Member] | Impaired Loans [Member] | Commercial Real Estate [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Outstanding Carrying Value	45,956	'	45,956	'	50,795
Level 3 [Member] | Impaired Loans [Member] | Multi Family [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Outstanding Carrying Value	3,140	'	3,140	'	12,577
Level 3 [Member] | Impaired Loans [Member] | Land [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Outstanding Carrying Value	$1,802	'	$1,802	'	$2,601

Fair_Value_Measurements_Change

Fair Value Measurements - Change in Assets Measured at Fair Value on a Nonrecurring Basis (Detail) (Assets Measured at Fair Value on a Nonrecurring Basis [Member], USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

In Thousands, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Jun. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Impaired Securities [Member]

Impaired Securities [Member]

Impaired Securities [Member]

Impaired Securities [Member]

Impaired Loans [Member]

Impaired Loans [Member]

Impaired Loans [Member]

Impaired Loans [Member]

Foreclosure Real Estate [Member]

Foreclosure Real Estate [Member]

Foreclosure Real Estate [Member]

Foreclosure Real Estate [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Beginning balance

$2,923

$3,721

$4,378

$4,221

$50,533

$65,240

$65,973

$66,269

$14,869

$26,370

$15,923

$28,278

Net new impaired loans

'

'

'

'

514

872

8,761

8,254

'

'

'

'

Impaired loans transferred to foreclosed real estate

'

'

'

'

'

-1,457

-3,040

-1,457

'

1,457

3,040

1,457

Other than temporary impairment write downs

-273

-964

-157

'

'

'

'

'

'

'

'

'

Principal repayments/sales

-46

-153

'

'

-149

-1,983

-18,858

-8,466

-2,701

-4,944

-6,809

-4,944

Chargeoffs of impaired loans

'

'

'

'

'

-548

-1,938

-2,476

'

'

'

'

Writedowns of carrying value subsequent to foreclosure

'

'

'

'

'

'

'

'

-250

-1,025

-1,029

-2,933

Recoveries of prior writedowns

'

'

'

'

'

'

'

'

'

'

74

'

Gains from sales

'

'

'

'

'

'

'

'

101

'

820

'

Ending balance

$2,604

$2,604

$4,221

$4,221

$50,898

$62,124

$50,898

$62,124

$12,019

$21,858

$12,019

$21,858

Fair_Value_Measurements_Carryi

Fair Value Measurements - Carrying and Estimated Fair Values of Financial Instruments (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Financial Assets:	'	'
Securities available for sale, net	$1,016	$1,000
Securities held to maturity, net	410,304	442,166
Estimated Fair Value [Member]	'	'
Financial Assets:	'	'
Cash and cash equivalents	30,253	60,395
Time deposits with banks	5,370	5,170
Securities available for sale, net	1,016	1,000
Securities held to maturity, net	410,304	442,166
FRB and FHLB stock	8,237	8,151
Loans receivable, net	1,072,203	1,102,333
Loan fees receivable	1,973	2,547
Accrued interest receivable	4,735	5,191
Total Financial Assets	1,534,091	1,626,953
Financial Liabilities:	'	'
Deposits	1,312,522	1,389,629
Accrued interest payable on deposits	1,398	2,379
Borrowed funds plus accrued interest payable	56,924	62,448
Commitments to lend	536	386
Total Financial Liabilities	1,371,380	1,454,842
Net Financial Assets	162,711	172,111
Carrying Value [Member]	'	'
Financial Assets:	'	'
Cash and cash equivalents	30,253	60,395
Time deposits with banks	5,370	5,170
Securities available for sale, net	1,016	1,000
Securities held to maturity, net	416,321	443,777
FRB and FHLB stock	8,237	8,151
Loans receivable, net	1,073,500	1,079,363
Loan fees receivable	2,511	3,108
Accrued interest receivable	4,735	5,191
Total Financial Assets	1,541,943	1,606,155
Financial Liabilities:	'	'
Deposits	1,298,403	1,362,619
Accrued interest payable on deposits	1,398	2,379
Borrowed funds plus accrued interest payable	57,165	62,930
Commitments to lend	536	386
Total Financial Liabilities	1,357,502	1,428,314
Net Financial Assets	$184,441	$177,841