National Bank (NBHC) 10-Q 12 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Nov. 07, 2013	Nov. 07, 2013
		Common Class A [Member]	Common Class B [Member]
Entity Information [Line Items]	'	'	'
Document Type	'10-Q	'	'
Amendment Flag	'false	'	'
Document Period End Date	30-Sep-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'Q3	'	'
Trading Symbol	'NBHC	'	'
Entity Registrant Name	'National Bank Holdings Corp	'	'
Entity Central Index Key	'0001475841	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Non-accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	42,325,987	3,127,774

Consolidated_Statements_of_Fin

Consolidated Statements of Financial Condition (Unaudited) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
ASSETS	'	'
Cash and due from banks	$69,185	$90,505
Due from Federal Reserve Bank of Kansas City	254,456	579,267
Interest bearing bank deposits	25,603	99,408
Cash and cash equivalents	349,244	769,180
Securities purchased under agreements to resell	75,000	0
Investment securities available-for-sale (at fair value)	1,889,962	1,718,028
Investment securities held-to-maturity (fair value of $664,578 and $584,551 at September 30, 2013 and December 31, 2012, respectively)	664,717	577,486
Non-marketable securities	31,725	32,996
Loans (including covered loans of $366,346 and $608,222 at September 30, 2013 and December 31, 2012, respectively)	1,742,813	1,832,702
Allowance for loan losses	-11,419	-15,380
Loans, net	1,731,394	1,817,322
Loans held for sale	5,265	5,368
Federal Deposit Insurance Corporation (bFDICb) indemnification asset, net	58,086	86,923
Other real estate owned	70,753	94,808
Premises and equipment, net	117,285	121,436
Goodwill	59,630	59,630
Intangible assets, net	23,566	27,575
Other assets	85,342	100,023
Total assets	5,161,969	5,410,775
Liabilities:	'	'
Non-interest bearing demand deposits	689,405	677,985
Interest bearing demand deposits	430,123	529,996
Savings and money market	1,297,585	1,240,020
Time deposits	1,534,390	1,752,718
Total deposits	3,951,503	4,200,719
Securities sold under agreements to repurchase	116,471	53,685
Due to FDIC	31,964	31,271
Other liabilities	30,781	34,541
Total liabilities	4,130,719	4,320,216
Stockholdersb equity:	'	'
Common stock, par value $0.01 per share: 400,000,000 shares authorized; 52,300,198 and 53,279,579 shares issued; 51,213,044 and 52,327,672 shares outstanding at September 30, 2013 and December 31, 2012, respectively	512	523
Additional paid in capital	989,614	1,006,194
Retained earnings	41,266	43,273
Treasury stock of 240 shares at December 31, 2012, at cost	0	-4
Accumulated other comprehensive income (loss), net of tax	-142	40,573
Total stockholdersb equity	1,031,250	1,090,559
Total liabilities and stockholdersb equity	$5,161,969	$5,410,775

Consolidated_Statements_of_Fin1

Consolidated Statements of Financial Condition (Unaudited) (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Investment securities held-to-maturity, fair value	$664,578	$584,551
Loans receivable, net - covered	$366,346	$608,222
Common Stock, par value (in dollars per share)	$0.01	$0.01
Common Stock, shares authorized	400,000,000	400,000,000
Common Stock, shares issued	52,300,198	53,279,579
Common Stock, shares outstanding	51,213,044	52,327,672
Treasury stock, shares	'	240

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Interest and dividend income:	'	'	'	'
Interest and fees on loans	$35,328	$40,105	$105,783	$129,290
Interest and dividends on investment securities	13,539	15,190	40,383	46,750
Dividends on non-marketable securities	388	377	1,170	1,142
Interest on interest-bearing bank deposits	267	370	762	1,595
Total interest and dividend income	49,522	56,042	148,098	178,777
Interest expense:	'	'	'	'
Interest on deposits	3,965	6,519	12,647	24,022
Interest on borrowings	42	27	80	88
Total interest expense	4,007	6,546	12,727	24,110
Net interest income before provision for loan losses	45,515	49,496	135,371	154,667
Provision for loan losses	437	5,263	3,524	25,325
Net interest income after provision for loan losses	45,078	44,233	131,847	129,342
Non-interest income:	'	'	'	'
FDIC indemnification asset negative accretion	-4,208	-2,832	-11,843	-9,165
FDIC loss sharing income	-1,191	1,503	3,278	9,278
Service charges	4,334	4,466	11,944	13,170
Bank card fees	2,482	2,484	7,509	7,168
Gain on sales of mortgages, net	345	283	1,125	886
Gain on sale of securities, net	0	0	0	674
Gain on previously charged-off acquired loans	224	837	1,118	2,627
Other non-interest income	1,352	1,322	4,682	3,744
Total non-interest income	3,338	8,063	17,813	28,382
Non-interest expense:	'	'	'	'
Salaries and employee benefits	22,639	27,182	69,363	72,226
Occupancy and equipment	6,556	5,570	18,391	14,845
Professional fees	791	2,669	3,045	8,612
Telecommunications and data processing	3,050	4,475	9,805	11,694
Marketing and business development	1,408	1,760	3,519	4,290
Supplies and printing	326	1,288	1,180	2,495
Other real estate owned expenses	459	3,468	7,675	12,152
Problem loan expenses	1,134	2,267	4,361	6,704
Intangible asset amortization	1,336	1,353	4,009	4,020
FDIC deposit insurance	1,021	1,152	3,074	3,664
ATM/debit card expenses	1,179	1,102	3,291	3,100
Banking center closure related expenses	3,389	0	3,389	0
Initial public offering related expenses	0	7,566	0	7,974
Acquisition related costs	0	0	0	870
Loss (gain) from the change in fair value of warrant liability	441	-1,154	138	-1,017
Other non-interest expense	2,884	1,259	8,487	6,602
Total non-interest expense	46,613	59,957	139,727	158,231
Income (loss) before income taxes	1,803	-7,661	9,933	-507
Income tax expense	856	230	4,006	3,039
Net income (loss)	$947	($7,891)	$5,927	($3,546)
Income per sharebbasic (in dollars per share)	$0.02	($0.15)	$0.11	($0.07)
Income per sharebdiluted (in dollars per share)	$0.02	($0.15)	$0.11	($0.07)
Weighted average number of common shares outstanding:	'	'	'	'
Basic (Shares)	51,454,200	52,191,239	51,940,245	52,186,465
Diluted (Shares)	51,501,980	52,191,239	51,973,161	52,186,465

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net income	$947	($7,891)	$5,927	($3,546)
Other comprehensive income (loss), net of tax:	'	'	'	'
Net unrealized gains (losses) arising during the period, net of tax benefit (expense) of $5,141 and ($1,498) for the three months ended September 30, 2013 and 2012, respectively; and net of tax benefit (expense) of $22,852 and ($2,624) for the nine months ended September 30, 2013 and 2012, respectively	-8,214	2,357	-36,015	4,074
Reclassification adjustment for net securities gains included in net income, net of tax expense of $263 for the nine months ended September 30, 2012	0	0	0	-411
Reclassification adjustment for net unrealized holding gains on securities transferred between available-for-sale and held-to-maturity, net of tax expense of $15,159 for the nine months ended September 30, 2012	0	0	0	-23,711
Securities available for sale, net	-8,214	2,357	-36,015	-20,048
Net unrealized holding gains on securities transferred between available-for-sale to held-to-maturity:	'	'	'	'
Net unrealized holding gains on securities transferred, net of tax expense of $15,159 for the nine months ended September 30, 2012	0	0	0	23,711
Less: amortization of net unrealized holding gains to income, net of tax benefit of $738 and $1,302 for the three months ended September 30, 2013 and 2012, respectively; and net of tax benefit of $2,943 and $2,215 for the nine months ended September 30, 2013 and 2012, respectively	-1,178	-2,036	-4,700	-3,933
Other comprehensive income, net	-1,178	-2,036	-4,700	19,778
Other comprehensive income (loss)	-9,392	321	-40,715	-270
Comprehensive loss	($8,445)	($7,570)	($34,788)	($3,816)

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]	'	'	'	'
Tax benefit (expense) on net unrealized gains (losses) arising during the period	$5,141	($1,498)	$22,852	($2,624)
Tax effect on reclassification adjustment for net securities gains included in net income	'	'	'	263
Reclassification adjustment for net unrealized holding gains on securities transferred between available-for-sale and held-to-maturity, net of tax	'	'	'	15,159
Tax effect of unrealized holding gains on securities transferred	'	'	'	-15,159
Tax benefit of amortization of net unrealized holding gains to income	$738	$1,302	$2,943	$2,515

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Stockholders' Equity (USD $)	Total	Common stock [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Treasury stock [Member]	Accumulated other comprehensive income, net [Member]
In Thousands, unless otherwise specified
Balance in the beginning at Dec. 31, 2011	$1,088,729	$522	$994,705	$46,480	$0	$47,022
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'
Net income	-3,546	0	0	-3,546	0	0
Stock-based compensation	10,922	0	10,922	0	0	0
Other comprehensive loss	-270	0	0	0	0	-270
Balance in the ending at Sep. 30, 2012	1,095,835	522	1,005,627	42,934	0	46,752
Balance in the beginning at Dec. 31, 2012	1,090,559	523	1,006,194	43,273	-4	40,573
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'
Net income	5,927	0	0	5,927	0	0
Stock-based compensation	4,003	0	4,003	0	0	0
(Repurchase) /retirement of shares	-20,590	-11	-20,583	0	4	0
Dividends paid ($0.15 per share)	-7,934	0	0	-7,934	0	0
Other comprehensive loss	-40,715	0	0	0	0	-40,715
Balance in the ending at Sep. 30, 2013	$1,031,250	$512	$989,614	$41,266	$0	($142)

Consolidated_Statements_of_Cha1

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) (USD $)	9 Months Ended
	Sep. 30, 2013
Statement of Stockholders' Equity [Abstract]	'
Dividends paid per share	$0.15

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:	'	'
Net income	$5,927	($3,546)
Adjustments to reconcile net income to net cash used in operating activities:	'	'
Provision for loan losses	3,524	25,325
Depreciation and amortization	11,698	8,946
Gain on sale of securities, net	0	-674
Current income tax receivable	-11,249	-15,765
Deferred income tax receivable	-10,848	-10,421
Discount accretion, net of premium amortization	6,692	13,110
Loan accretion	-66,906	-93,497
Net gain on sale of mortgage loans	-1,125	-886
Origination of loans held for sale	-47,754	-42,678
Proceeds from sales of loans held for sale	47,832	39,844
Amortization of indemnification asset	11,843	9,165
Gain on the sale of other real estate owned, net	-7,384	-6,792
Impairment on other real estate owned	9,142	8,638
Impairment on fixed assets related to banking center closures	2,531	0
Stock-based compensation	4,003	10,922
Increase (decrease) in due to FDIC, net	693	-35,470
Decrease (increase) in other assets	1,739	-378
Increase (decrease) in other liabilities	1,338	-15,805
Net cash used in operating activities	-38,304	-109,962
Cash flows from investing activities:	'	'
Purchase of FHLB of Des Moines stock	0	-4,018
Sale of FHLB stock	1,271	89
Sales of investment securities available-for-sale	0	20,794
Maturities of investment securities held-to-maturity	149,991	113,590
Maturities of investment securities available-for-sale	456,122	352,137
Purchase of investment securities held-to-maturity	-244,502	-2,234
Purchase of investment securities available-for-sale	-693,977	-1,003,593
Increase in securities purchased under agreements to resell	-75,000	0
Net decrease in loans	118,052	363,479
Purchase of premises and equipment	-6,069	-35,994
Proceeds from sales of other real estate owned	54,705	57,186
Decrease in FDIC indemnification asset	72,634	67,822
Net cash used in investing activities	-166,773	-70,742
Cash flows from financing activities:	'	'
Net decrease in deposits	-249,216	-781,329
Increase (decrease) in repurchase agreements	62,786	-1,405
Payment of dividends	-7,839	0
Repurchase of shares	-20,590	0
Net cash used in financing activities	-214,859	-782,734
Decrease in cash and cash equivalents	-419,936	-963,438
Cash and cash equivalents at beginning of the year	769,180	1,628,137
Cash and cash equivalents at end of period	349,244	664,699
Supplemental disclosure of cash flow information:	'	'
Cash paid during the period for interest	13,741	30,428
Cash paid during the period for taxes	26,271	29,228
Supplemental schedule of non-cash investing activities:	'	'
Loans transferred to other real estate owned at fair value	32,408	67,741
FDIC indemnification asset claims transferred to other assets	24,460	109,142
Available-for-sale investment securities transferred to investment securities held-to-maturity	$0	$754,063

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	National Bank Holdings Corporation (the “Company”) is a bank holding company that was incorporated in the State of Delaware in June 2009 with the intent to acquire and operate community banking franchises and other complementary businesses in targeted markets. The accompanying unaudited consolidated interim financial statements include the accounts of the Company and its wholly owned subsidiary, NBH Bank, N.A. NBH Bank, N.A. is the resulting entity from the Company's acquisitions to date and it offers consumer and commercial banking through banking centers that are predominately located in the greater Kansas City area and Colorado.
	These interim financial statements serve to update the National Bank Holdings Corporation Annual Report on Form 10-K for the year ended December 31, 2012. The accompanying unaudited financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and where applicable, with general practices in the banking industry or guidelines prescribed by bank regulatory agencies. However, they may not include all information and notes necessary to constitute a complete set of financial statements under GAAP applicable to annual periods and accordingly should be read in conjunction with the financial information contained in the Form 10-K. The unaudited consolidated interim financial statements reflect all adjustments which are, in the opinion of management, necessary for a fair statement of the results presented. All such adjustments are of a normal recurring nature. All significant intercompany balances and transactions have been eliminated in consolidation. Certain reclassifications of prior years' amounts are made whenever necessary to conform to current period presentation. The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period.
	The Company's significant accounting policies followed in the preparation of the unaudited consolidated interim financial statements are disclosed in Note 2 of the audited financial statements and notes for the year ended December 31, 2012 are contained in the Company's Annual Report on Form 10-K, referenced above. During the nine months ended September 30, 2013, the Company began entering into agreements with certain financial institutions whereby the Company purchases securities under agreements to resell as of a specified future date at a specified price plus accrued interest. The securities purchased under agreements to resell are carried at the contractual amounts at which the securities will subsequently be resold, including accrued interest. The securities purchased under agreement to resell are subject to a master netting arrangement; however, the Company has not offset any of the amounts shown in the unaudited consolidated interim financial statements. The securities are pledged as collateral by the counterparties and are held by a third party custodian. The collateral is valued daily and additional collateral may be obtained or refunded as necessary to maintain full collateralization of these transactions. There have been no other significant changes to the application of significant accounting policies since December 31, 2012.
	GAAP requires management to make estimates that affect the reported amounts of assets, liabilities, revenues and expenses, and disclosures of contingent assets and liabilities. By their nature, estimates are based on judgment and available information. Management has made significant estimates in certain areas, such as the amount and timing of expected cash flows from assets, the valuation of the FDIC indemnification asset and clawback liability, the valuation of other real estate owned (“OREO”), the fair value adjustments on assets acquired and liabilities assumed, the valuation of core deposit intangible assets, the evaluation of investment securities for other-than-temporary impairment (“OTTI”), the fair values of financial instruments, the allowance for loan losses (“ALL”), and contingent liabilities. Because of the inherent uncertainties associated with any estimation process and future changes in market and economic conditions, it is possible that actual results could differ significantly from those estimates.

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income—In February 2013, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2013-02, Comprehensive Income-Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. This guidance requires entities to provide information about the amounts reclassified out of accumulated other comprehensive income by component. Entities are also required to present significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income, but only if the amount reclassified is required to be reclassified to net income in its entirety in the same accounting period. Other amounts that are not required to be reclassified to net income are to be cross-referenced to other disclosures that provide additional detail about those amounts. The Company was required to adopt this update in 2013 with retrospective application. Adoption of this update affects the presentation of the components of comprehensive income in the Company’s financial statements, but did not have an impact on the Company’s consolidated statements of financial condition, results of operations or liquidity.

Investment_Securities

Investment Securities	9 Months Ended
	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'
Investment Securities	'
	Investment Securities
	The Company’s investment securities portfolio is comprised of available-for-sale and held-to-maturity investment securities. These investment securities totaled $2.6 billion at September 30, 2013, an increase from $2.3 billion at December 31, 2012. Included in the aforementioned $2.6 billion was $1.9 billion of available-for-sale securities and $0.7 billion of held-to-maturity securities.
	Available-for-sale
	Available-for-sale investment securities are summarized as follows as of the dates indicated (in thousands):
		September 30, 2013
		Amortized		Gross			Gross			Fair Value
		Cost		Unrealized			Unrealized
				Gains			Losses
	Asset backed securities	$	20,091	$	7		$	—		$	20,098
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	514,584		9,525			(926		)	523,183
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	1,376,453		11,211			(41,402		)	1,346,262
	Other securities	419		—			—			419
	Total	$	1,911,547	$	20,743		$	(42,328	)	$	1,889,962
		December 31, 2012
		Amortized		Gross			Gross			Fair Value
		Cost		Unrealized			Unrealized
				Gains			Losses
	U.S. Treasury securities	$	300	$	—		$	—		$	300
	Asset backed securities	89,881		122			—			90,003
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	658,169		19,849			(1		)	678,017
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	931,979		17,630			(320		)	949,289
	Other securities	419		—			—			419
	Total	$	1,680,748	$	37,601		$	(321	)	$	1,718,028
	At September 30, 2013 and December 31, 2012, mortgage-backed securities represented 98.9% and 94.7%, respectively, of the Company’s available-for-sale investment portfolio and all mortgage-backed securities were backed by government sponsored enterprises (“GSE”) collateral such as Federal Home Loan Mortgage Corporation (“FHLMC”) and Federal National Mortgage Association (“FNMA”), and the government sponsored agency Government National Mortgage Association (“GNMA”).
	The table below summarizes the unrealized losses as of the dates shown, along with the length of the impairment period (in thousands):
		September 30, 2013
		Less than 12 months					12 months or more						Total
		Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Losses			Value			Losses			Value		Losses
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	212,138	$	(925	)	$	14		$	(1	)	$	212,152	$	(926	)
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	922,778		(40,928		)	17,302			(474		)	940,080		(41,402		)
	Total	$	1,134,916	$	(41,853	)	$	17,316		$	(475	)	$	1,152,232	$	(42,328	)
		December 31, 2012
		Less than 12 months					12 months or more						Total
		Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Losses			Value			Losses			Value		Losses
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	17	$	—		$	8		$	(1	)	$	25	$	(1	)
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	130,686		(320		)	—			—			130,686		(320		)
	Total	$	130,703	$	(320	)	$	8		$	(1	)	$	130,711	$	(321	)
	Management evaluated all of the securities in an unrealized loss position and concluded that no other-than-temporary-impairment existed at September 30, 2013 or December 31, 2012. The Company had no intention to sell these securities before recovery of their amortized cost and believes it will not be required to sell the securities before the recovery of their amortized cost.
	The Company pledges certain securities as collateral for public deposits, securities sold under agreements to repurchase and to secure borrowing capacity at the Federal Reserve Bank, if needed. The fair value of available-for-sale investment securities pledged as collateral totaled $188.6 million at September 30, 2013 and $89.2 million December 31, 2012. The increase of pledged available-for-sale investment securities was primarily attributable to the increase in securities sold under agreements to repurchase during the nine months ended September 30, 2013. Certain investment securities may also be pledged as collateral should the Company utilize its line of credit at the FHLB of Des Moines; however, no investment securities were pledged for this purpose at September 30, 2013 or December 31, 2012.
	The table below summarizes the contractual maturities, as of the last scheduled repayment date, of the available-for-sale investment portfolio as of September 30, 2013 (in thousands):
		Amortized		Fair Value
		Cost
	Due in one year or less	$	—	$	—
	Due after one year through five years	20,101		20,107
	Due after five years through ten years	206,538		206,575
	Due after ten years	1,684,489		1,662,861
	Other securities	419		419
	Total investment securities available-for-sale	$	1,911,547	$	1,889,962
	Actual maturities of mortgage-backed securities may differ from contractual maturities depending on the repayment characteristics and experience of the underlying financial instruments. The estimated weighted average life of the available-for-sale mortgage-backed securities portfolio was 4.4 years as of September 30, 2013 and 3.4 years as of December 31, 2012. This estimate is based on assumptions and actual results may differ. Other securities of $0.4 million have no stated contractual maturity date as of September 30, 2013.
	Held-to-maturity
	At September 30, 2013 and December 31, 2012 the Company held $664.7 million and $577.5 million of held-to-maturity investment securities, respectively. During the first quarter of 2012 the Company transferred securities with a fair value of $754.1 million from an available-for-sale classification to the held-to-maturity classification. During the nine months ended September 30, 2013, the Company purchased $244.5 million of held-to-maturity investment securities. Held-to-maturity investment securities are summarized as follows as of the dates indicated (in thousands):
		September 30, 2013
		Amortized		Gross			Gross			Fair Value
		Cost		Unrealized			Unrealized
				Gains			Losses
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	530,406	$	3,613		$	(555	)	$	533,464
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	134,311		142			(3,339		)	131,114
Total investment securities held-to-maturity	$	664,717	$	3,755		$	(3,894	)	$	664,578
	December 31, 2012
	Amortized		Gross			Gross			Fair
	Cost		Unrealized			Unrealized			Value
			Gains			Losses
Mortgage-backed securities (“MBS”):
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	577,486	$	7,065		$	—		$	584,551
Total investment securities held-to-maturity	$	577,486	$	7,065		$	—		$	584,551
The table below summarizes the contractual maturities, as of the last scheduled repayment date, of the held-to-maturity investment portfolio at September 30, 2013 (in thousands):
	Amortized		Fair Value
	Cost
Due in one year or less	$	—	$	—
Due after one year through five years	—		—
Due after five years through ten years	19,012		19,235
Due after ten years	645,705		645,343
Other securities	—		—
Total investment securities held-to-maturity	$	664,717	$	664,578
The carrying value of held-to-maturity investment securities pledged as collateral totaled $54.4 million and $127.9 million at September 30, 2013 and December 31, 2012, respectively. Actual maturities of mortgage-backed securities may differ from scheduled maturities depending on the repayment characteristics and experience of the underlying financial instruments. The estimated weighted average expected life of the held-to-maturity mortgage-backed securities portfolio as of September 30, 2013 and December 31, 2012 was 4.3 and 3.8 years, respectively. This estimate is based on assumptions and actual results may differ.

Loans

Loans	9 Months Ended
	Sep. 30, 2013
Receivables [Abstract]	'
Loans	'
	Loans
	The loan portfolio is comprised of new loans originated by the Company and loans that were acquired in connection with the Company’s acquisitions of Bank of Choice and Community Banks of Colorado in 2011, and Hillcrest Bank and Bank Midwest in 2010. The majority of the loans acquired in the Hillcrest Bank and Community Banks of Colorado transactions are covered by loss sharing agreements with the FDIC, and covered loans are presented separately from non-covered loans due to the FDIC loss sharing agreements associated with these loans. Covered loans comprised 21.0% of the total loan portfolio at September 30, 2013, compared to 33.2% of the total loan portfolio at December 31, 2012.
	The table below shows the loan portfolio composition including carrying value by segment of loans accounted for under ASC Topic 310-30 Receivables—Loans and Debt Securities Acquired with Deteriorated Credit Quality and loans not accounted for under this guidance, which includes our originated loans. The table also shows the amounts covered by the FDIC loss sharing agreements as of September 30, 2013 and December 31, 2012. The carrying value of loans are net of discounts on loans excluded from Accounting Standards Codification (“ASC”) Topic 310-30 , and fees and costs of $15.0 million and $20.4 million as of September 30, 2013 and December 31, 2012, respectively (in thousands):
		September 30, 2013
		ASC 310-30			Non 310-30			Total Loans		% of
		Loans			Loans					Total
	Commercial	$	68,250		$	272,114		$	340,364	19.5	%
	Commercial real estate	325,701			288,752			614,453		35.3	%
	Agriculture	37,882			117,464			155,346		8.9	%
	Residential real estate	72,409			523,160			595,569		34.2	%
	Consumer	8,768			28,313			37,081		2.1	%
	Total	$	513,010		$	1,229,803		$	1,742,813	100	%
	Covered	$	309,380		$	56,966		$	366,346	21	%
	Non-covered	203,630			1,172,837			1,376,467		79	%
	Total	$	513,010		$	1,229,803		$	1,742,813	100	%
		December 31, 2012
		ASC 310-30			Non 310-30			Total Loans		% of
		Loans			Loans					Total
	Commercial	$	83,169		$	187,419		$	270,588	14.8	%
	Commercial real estate	566,035			238,964			804,999		43.9	%
	Agriculture	47,733			125,674			173,407		9.5	%
	Residential real estate	106,100			427,277			533,377		29.1	%
	Consumer	18,984			31,347			50,331		2.7	%
	Total	$	822,021		$	1,010,681		$	1,832,702	100	%
	Covered	$	527,948		$	80,274		$	608,222	33.2	%
	Non-covered	294,073			930,407			1,224,480		66.8	%
	Total	$	822,021		$	1,010,681		$	1,832,702	100	%
	Loans are considered past due or delinquent when the contractual principal or interest due in accordance with the terms of the loan agreement remains unpaid after the due date of the scheduled payment. All loans accounted for under ASC 310-30 were classified as performing assets at December 31, 2012, regardless of past due status, as the carrying value of all of the respective pools’ cash flows were considered estimable. During the nine months ended September 30, 2013, the Company determined that the cash flows of one covered commercial and industrial loan pool, with a balance of $16.9 million at September 30, 2013, were no longer reasonably estimable, and in accordance with the guidance in ASC 310-30, this pool was put on non-accrual status. Interest income was recognized on all accruing loans accounted for under ASC 310-30 through accretion of the difference between the carrying value of the loans and the expected cash flows.
	Pooled loans accounted for under ASC 310-30 that are 90 days or more past due and still accreting are generally considered to be performing and are included in loans 90 days or more past due and still accruing. At September 30, 2013 and December 31, 2012, $14.0 million and $23.1 million, respectively, of loans excluded from the scope of ASC 310-30 were on non-accrual and $16.9 million of loans accounted for under ASC 310-30 were on non-accrual status at September 30, 2013. Loan delinquency for all loans is shown in the following tables at September 30, 2013 and December 31, 2012, respectively (in thousands):
		Total Loans September 30, 2013
		30-59			60-89			Greater		Total  past		Current		Total		Loans > 90		Non-
		days  past			days			than 90		due				loans		days past		accrual
		due			past			days past								due and
					due			due								still
																accruing
	Loans excluded from ASC 310-30
	Commercial	$	410		$	57		$	448	$	915	$	271,199	$	272,114	$	—	$	1,288
	Commercial real estate
	Construction	—			—			—		—		1,652		1,652		—		—
	Acquisition/development	46			—			148		194		7,900		8,094		148		1
	Multifamily	952			—			—		952		7,384		8,336		—		1,129
	Owner-occupied	154			17			—		171		88,846		89,017		—		728
	Non owner-occupied	116			—			4,643		4,759		176,894		181,653		—		4,643
	Total commercial real estate	1,268			17			4,791		6,076		282,676		288,752		148		6,501
	Agriculture	84			—			—		84		117,380		117,464		—		203
	Residential real estate
	Senior lien	1,043			132			1,230		2,405		468,089		470,494		—		5,160
	Junior lien	262			24			132		418		52,248		52,666		—		591
	Total residential real estate	1,305			156			1,362		2,823		520,337		523,160		—		5,751
	Consumer	427			8			24		459		27,854		28,313		21		251
	Total loans excluded from ASC 310-30	3,494			238			6,625		10,357		1,219,446		1,229,803		169		13,994
	Covered loans excluded from ASC 310-30	186			53			425		664		56,302		56,966		—		2,403
	Non-covered loans excluded from ASC 310-30	3,308			185			6,200		9,693		1,163,144		1,172,837		169		11,591
	Total loans excluded from ASC 310-30	3,494			238			6,625		10,357		1,219,446		1,229,803		169		13,994
	Loans accounted for under ASC 310-30
	Commercial	325			564			5,000		5,889		62,361		68,250		4,964		16,857
	Commercial real estate	12,943			8,731			52,773		74,447		251,254		325,701		52,773		—
	Agriculture	3,289			—			2,669		5,958		31,924		37,882		2,669		—
	Residential real estate	1,349			271			1,907		3,527		68,882		72,409		1,907		—
	Consumer	585			6			11		602		8,166		8,768		11		—
	Total loans accounted for under ASC 310-30	18,491			9,572			62,360		90,423		422,587		513,010		62,324		16,857
	Covered loans accounted for under ASC 310-30	11,433			9,199			51,115		71,747		237,633		309,380		51,079		16,857
	Non-covered loans accounted for under ASC 310-30	7,058			373			11,245		18,676		184,954		203,630		11,245		—
Total loans accounted for under ASC 310-30	18,491			9,572			62,360		90,423		422,587		513,010		62,324		16,857
Total loans	$	21,985		$	9,810		$	68,985	$	100,780	$	1,642,033	$	1,742,813	$	62,493	$	30,851
Covered loans	$	11,619		$	9,252		$	51,540	$	72,411	$	293,935	$	366,346	$	51,079	$	19,260
Non-covered loans	10,366			558			17,445		28,369		1,348,098		1,376,467		11,414		11,591
Total loans	$	21,985		$	9,810		$	68,985	$	100,780	$	1,642,033	$	1,742,813	$	62,493	$	30,851
	Total Loans December 31, 2012
	30-59			60-89			Greater		Total  past		Current		Total		Loans > 90		Non-
	days  past			days			than 90		due				loans		days past		accrual
	due			past			days past								due and
				due			due								still
															accruing
Loans excluded from ASC 310-30
Commercial	$	846		$	148		$	1,122	$	2,116	$	185,303	$	187,419	$	—	$	4,500
Commercial real estate
Construction	—			—			—		—		3,915		3,915		—		—
Acquisition/development	1,948			—			—		1,948		8,485		10,433		—		75
Multifamily	—			—			34		34		13,387		13,421		—		237
Owner-occupied	97			106			1,074		1,277		56,490		57,767		—		3,365
Non owner-occupied	—			122			5,123		5,245		148,183		153,428		—		7,992
Total commercial real estate	2,045			228			6,231		8,504		230,460		238,964		—		11,669
Agriculture	33			40			11		84		125,590		125,674		—		251
Residential real estate
Senior lien	1,261			119			1,825		3,205		373,243		376,448		22		5,815
Junior lien	181			—			110		291		50,538		50,829		—		593
Total residential real estate	1,442			119			1,935		3,496		423,781		427,277		22		6,408
Consumer	447			48			3		498		30,849		31,347		3		291
Total loans excluded from ASC 310-30	4,813			583			9,302		14,698		995,983		1,010,681		25		23,119
Covered loans excluded from ASC 310-30	75			51			2,062		2,188		78,086		80,274		—		6,045
Non-covered loans excluded from ASC 310-30	4,738			532			7,240		12,510		917,897		930,407		25		17,074
Total loans excluded from ASC 310-30	4,813			583			9,302		14,698		995,983		1,010,681		25		23,119
Loans accounted for under ASC 310-30
Commercial	521			563			5,621		6,705		76,464		83,169		5,621		—
Commercial real estate	10,060			3,928			129,656		143,644		422,391		566,035		129,656		—
Agriculture	1,247			16			2,768		4,031		43,702		47,733		2,768		—
Residential real estate	1,247			207			5,463		6,917		99,183		106,100		5,463		—
Consumer	297			327			3,253		3,877		15,107		18,984		3,253		—
Total loans accounted for under ASC 310-30	13,372			5,041			146,761		165,174		656,847		822,021		146,761		—
Covered loans accounted for under ASC 310-30	9,855			3,613			116,883		130,351		397,597		527,948		116,883		—
Non-covered loans accounted for under ASC 310-30	3,517			1,428			29,878		34,823		259,250		294,073		29,878		—
Total loans accounted for under ASC 310-30	13,372			5,041			146,761		165,174		656,847		822,021		146,761		—
Total loans	$	18,185		$	5,624		$	156,063	$	179,872	$	1,652,830	$	1,832,702	$	146,786	$	23,119
Covered loans	$	9,930		$	3,664		$	118,945	$	132,539	$	475,683	$	608,222	$	116,883	$	6,045
Non-covered loans	8,255			1,960			37,118		47,333		1,177,147		1,224,480		29,903		17,074
Total loans	$	18,185		$	5,624		$	156,063	$	179,872	$	1,652,830	$	1,832,702	$	146,786	$	23,119
Credit exposure for all loans as determined by the Company’s internal risk rating system was as follows as of September 30, 2013 and December 31, 2012, respectively (in thousands):
	Total Loans September 30, 2013
	Pass			Special			Substandard		Doubtful		Total
				Mention
Loans excluded from ASC 310-30
Commercial	$	225,067		$	8,353		$	38,612	$	82	$	272,114
Commercial real estate
Construction	1,652			—			—		—		1,652
Acquisition/development	1,593			2,646			3,855		—		8,094
Multifamily	7,207			—			1,097		32		8,336
Owner-occupied	83,532			1,998			3,487		—		89,017
Non owner-occupied	140,405			32,143			9,105		—		181,653
Total commercial real estate	234,389			36,787			17,544		32		288,752
Agriculture	115,618			1,084			762		—		117,464
Residential real estate
Senior lien	461,003			1,547			7,467		477		470,494
Junior lien	50,113			203			2,350		—		52,666
Total residential real estate	511,116			1,750			9,817		477		523,160
Consumer	28,057			—			250		6		28,313
Total loans excluded from ASC 310-30	1,114,247			47,974			66,985		597		1,229,803
Covered loans excluded from ASC 310-30	27,826			3,557			25,133		450		56,966
Non-covered loans excluded from ASC 310-30	1,086,421			44,417			41,852		147		1,172,837
Total loans excluded from ASC 310-30	1,114,247			47,974			66,985		597		1,229,803
Loans accounted for under ASC 310-30
Commercial	25,073			2,865			39,520		792		68,250
Commercial real estate	134,979			11,757			170,988		7,977		325,701
Agriculture	26,883			1,724			9,275		—		37,882
Residential real estate	49,444			1,610			21,355		—		72,409
Consumer	7,515			504			749		—		8,768
Total loans accounted for under ASC 310-30	243,894			18,460			241,887		8,769		513,010
Covered loans accounted for under ASC 310-30	128,530			8,146			166,859		5,845		309,380
Non-covered loans accounted for under ASC 310-30	115,364			10,314			75,028		2,924		203,630
Total loans accounted for under ASC 310-30	243,894			18,460			241,887		8,769		513,010
Total loans	$	1,358,141		$	66,434		$	308,872	$	9,366	$	1,742,813
Total covered	$	156,356		$	11,703		$	191,992	$	6,295	$	366,346
Total non-covered	1,201,785			54,731			116,880		3,071		1,376,467
Total loans	$	1,358,141		$	66,434		$	308,872	$	9,366	$	1,742,813
	Total Loans December 31, 2012
	Pass			Special			Substandard		Doubtful		Total
				Mention
Loans excluded from ASC 310-30
Commercial	$	137,537		$	9,776		$	38,696	$	1,410	$	187,419
Commercial real estate
Construction	3,915			—			—		—		3,915
Acquisition/development	6,727			—			3,706		—		10,433
Multifamily	8,409			3,798			1,201		13		13,421
Owner-occupied	44,129			4,006			9,632		—		57,767
Non owner-occupied	104,307			29,394			19,411		316		153,428
Total commercial real estate	167,487			37,198			33,950		329		238,964
Agriculture	120,471			1,359			3,844		—		125,674
Residential real estate
Senior lien	365,571			2,240			8,106		531		376,448
Junior lien	48,359			251			2,214		5		50,829
Total residential real estate	413,930			2,491			10,320		536		427,277
Consumer	31,050			—			276		21		31,347
Total loans excluded from ASC 310-30	870,475			50,824			87,086		2,296		1,010,681
Covered loans excluded from ASC 310-30	32,117			9,974			36,427		1,756		80,274
Non-covered loans excluded from ASC 310-30	838,358			40,850			50,659		540		930,407
Total loans excluded from ASC 310-30	870,475			50,824			87,086		2,296		1,010,681
Loans accounted for under ASC 310-30
Commercial	29,719			3,628			42,101		7,721		83,169
Commercial real estate	162,122			60,787			329,869		13,257		566,035
Agriculture	34,599			1,242			11,892		—		47,733
Residential real estate	57,697			6,614			41,789		—		106,100
Consumer	14,489			723			3,772		—		18,984
Total loans accounted for under ASC 310-30	298,626			72,994			429,423		20,978		822,021
Covered loans accounted for under ASC 310-30	159,430			57,056			292,174		19,288		527,948
Non-covered loans accounted for under ASC 310-30	139,196			15,938			137,249		1,690		294,073
Total loans accounted for under ASC 310-30	298,626			72,994			429,423		20,978		822,021
Total loans	$	1,169,101		$	123,818		$	516,509	$	23,274	$	1,832,702
Total covered	$	191,547		$	67,030		$	328,601	$	21,044	$	608,222
Total non-covered	977,554			56,788			187,908		2,230		1,224,480
Total loans	$	1,169,101		$	123,818		$	516,509	$	23,274	$	1,832,702
Impaired Loans
Loans are considered to be impaired when it is probable that the Company will not be able to collect all amounts due in accordance with the contractual terms of the loan agreement. Included in impaired loans are loans excluded from ASC 310-30 on non-accrual status and troubled debt restructurings (“TDRs”) described below. If a specific allowance is warranted based on the borrower’s overall financial condition, the specific allowance is calculated based on discounted cash flows using the loan’s initial contractual effective interest rate or the fair value of the collateral less selling costs for collateral dependent loans. At September 30, 2013, the Company measured $14.8 million of impaired loans using discounted cash flows and the loan’s initial contractual effective interest rate and $4.7 million of impaired loans based on the fair value of the collateral less selling costs. $9.5 million of impaired loans that individually are less than $250 thousand each, are measured through our general ALL reserves due to their relatively small size.
At September 30, 2013, the Company’s recorded investment in impaired loans was $29.1 million, $8.4 million of which was covered by loss sharing agreements. Impaired loans had a collective related allowance for loan losses allocated to them of $0.7 million at September 30, 2013. Additional information regarding impaired loans at September 30, 2013 is set forth in the table below (in thousands):
	Impaired Loans September 30, 2013
	Unpaid			Recorded			Allowance		Average		Interest
	principal			investment			for loan		recorded		income
	balance						losses		investment		recognized
							allocated
With no related allowance recorded:
Commercial	$	5,114		$	5,100		$	—	$	6,169	$	276
Commercial real estate
Construction	—			—			—		—		—
Acquisition/development	—			—			—		—		—
Multifamily	997			952			—		958		—
Owner-occupied	4,208			3,921			—		4,031		226
Non-owner occupied	6,262			4,941			—		5,188		8
Total commercial real estate	11,467			9,814			—		10,177		234
Agriculture	—			—			—		—		—
Residential real estate
Senior lien	762			751			—		752		6
Junior lien	—			—			—		—		—
Total residential real estate	762			751			—		752		6
Consumer	—			—			—		—		—
Total impaired loans with no related allowance recorded	17,343			15,665			—		17,098		516
With a related allowance recorded:
Commercial	2,712			2,570			92		2,744		53
Commercial real estate
Construction	—			—			—		—		—
Acquisition/development	—			1			—		1		—
Multifamily	184			177			32		187		—
Owner-occupied	843			634			4		668		11
Non-owner occupied	644			632			4		636		14
Total commercial real estate	1,671			1,444			40		1,492		25
Agriculture	244			223			1		224		—
Residential real estate
Senior lien	7,959			7,166			516		7,310		71
Junior lien	1,924			1,712			17		1,736		40
Total residential real estate	9,883			8,878			533		9,046		111
Consumer	319			295			7		313		3
Total impaired loans with a related allowance recorded	14,829			13,410			673		13,819		192
Total impaired loans	$	32,172		$	29,075		$	673	$	30,917	$	708
At September 30, 2012, the Company’s recorded investment in impaired loans was $37.6 million, $7.5 million of which was covered by loss sharing agreements. The impaired loans had a collective related allowance for loan losses allocated to them of $2.0 million at September 30, 2012. The table below shows additional information regarding impaired loans at September 30, 2012 (in thousands):
	Impaired Loans September 30, 2012
	Unpaid			Recorded			Allowance		Average		Interest
	principal			investment			for loan		recorded		income
	balance						losses		investment		recognized
							allocated
With no related allowance recorded:
Commercial	$	19,544		$	9,521		$	—	$	13,038	$	179
Commercial real estate
Construction	—			—			—		—		—
Acquisition/development	6,904			799			—		830		27
Multifamily	198			191			—		191		—
Owner-occupied	5,814			5,450			—		5,455		118
Non owner-occupied	7,050			6,504			—		5,823		64
Total commercial real estate	19,966			12,944			—		12,299		209
Agriculture	185			178			—		181		1
Residential real estate
Senior lien	6,616			6,169			—		6,241		94
Junior lien	996			671			—		675		4
Total residential real estate	7,612			6,840			—		6,916		98
Consumer	206			193			—		195		1
Total impaired loans with no related allowance recorded	47,513			29,676			—		32,629		488
With a related allowance recorded:
Commercial	2,066			2,065			1,091		2,185		8
Commercial real estate
Construction	—			—			—		—		—
Acquisition/development	—			—			—		—		—
Multifamily	—			—			—		—		—
Owner-occupied	—			—			—		—		—
Non owner-occupied	5,688			5,123			517		5,284		—
Total commercial real estate	5,688			5,123			517		5,284		—
Agriculture	—			—			—		—		—
Residential real estate
Senior lien	445			421			421		440		—
Junior lien	271			271			3		271		—
Total residential real estate	716			692			424		711		—
Consumer	—			—			—		—		—
Total impaired loans with a related allowance recorded	8,470			7,880			2,032		8,180		8
Total impaired loans	$	55,983		$	37,556		$	2,032	$	40,809	$	496
Troubled debt restructurings
It is the Company’s policy to review each prospective credit in order to determine the appropriateness and the adequacy of security or collateral prior to making a loan. In the event of borrower default, the Company seeks recovery in compliance with state lending laws, the respective loan agreements, and credit monitoring and remediation procedures that may include restructuring a loan to provide a concession by the Company to the borrower from their original terms due to borrower financial difficulties in order to facilitate repayment. Additionally, if a borrower’s repayment obligation has been discharged by a court, and that debt has not been reaffirmed by the borrower, regardless of past due status, the loan is considered to be a troubled debt restructuring (“TDR”). At September 30, 2013 and December 31, 2012, the Company had $14.3 million and $17.7 million, respectively, of accruing TDR’s that had been restructured from the original terms in order to facilitate repayment. Of these, $6.0 million and $5.0 million, respectively, were covered by FDIC loss sharing agreements.
Non-accruing TDR’s at September 30, 2013 and December 31, 2012 totaled $7.6 million and $12.9 million, respectively. Of these, $1.7 million were covered by the FDIC loss sharing agreements as of September 30, 2013 and $3.6 million were covered by the FDIC loss sharing agreements as of December 31, 2012.
During the nine months ended September 30, 2013, the Company restructured forty-three loans with a recorded investment of $5.5 million to facilitate repayment. Substantially all of the loan modifications were an extension of term and rate modifications. Loan modifications to loans accounted for under ASC 310-30 are not considered troubled debt restructurings. The table below provides additional information related to accruing TDR’s at September 30, 2013 and December 31, 2012 (in thousands):
	Accruing TDR’s
	30-Sep-13
	Recorded			Average			Unpaid		Unfunded
	investment			year-to-			principal		commitments
				date			balance		to fund
				recorded					TDR’s
				investment
Commercial	$	10,210		$	11,385		$	10,475	$	4,039
Commercial real estate	930			954			1,009		879
Agriculture	21			20			20		—
Residential real estate	3,085			3,131			3,096		20
Consumer	44			47			44		—
Total	$	14,290		$	15,537		$	14,644	$	4,938
	Accruing TDR’s
	December 31, 2012
	Recorded			Average			Unpaid		Unfunded
	investment			year-to-			principal		commitments
				date			balance		to fund
				recorded					TDR’s
				investment
Commercial	$	11,474		$	13,171		$	11,794	$	6,908
Commercial real estate	3,597			3,708			3,734		—
Agriculture	—			—			—		—
Residential real estate	2,458			2,469			2,460		35
Consumer	191			195			191		—
Total	$	17,720		$	19,543		$	18,179	$	6,943
The following table summarizes the Company’s carrying value of non-accrual TDR’s as of September 30, 2013 and December 31, 2012 (in thousands):
	Non - Accruing TDR’s
	September 30, 2013						December 31, 2012
	Covered			Non-covered			Covered		Non-covered
Commercial	$	89		$	655		$	1,736	$	1,215
Commercial real estate	178			4,439			313		6,823
Agriculture	—			—			—		21
Residential real estate	1,407			605			1,514		958
Consumer	—			248			—		291
Total	$	1,674		$	5,947		$	3,563	$	9,308
Accrual of interest is resumed on loans that were on non-accrual at the time of restructuring, only after the loan has performed sufficiently. The Company had two TDRs that had been modified within the past 12 months that defaulted on their restructured terms during the nine months ended September 30, 2013. For purposes of this disclosure, the Company considers “default” to mean 90 days or more past due on principal or interest. The defaulted TDRs were a commercial loan and a consumer loan totaling $328 thousand.
Loans accounted for under ASC Topic 310-30
Loan pools accounted for under ASC Topic 310-30 are periodically remeasured to determine expected future cash flows. In determining the expected cash flows, the timing of cash flows and prepayment assumptions for smaller homogeneous loans are based on statistical models that take into account factors such as the loan interest rate, credit profile of the borrowers, the years in which the loans were originated, and whether the loans are fixed or variable rate loans. Prepayments may be assumed on large loans if circumstances specific to that loan warrant a prepayment assumption. No prepayments were presumed for small homogeneous commercial loans; however, prepayment assumptions are made that consider similar prepayment factors listed above for smaller homogeneous loans. The re-measurement of loans accounted for under ASC 310-30 resulted in the following changes in the carrying amount of accretable yield during the nine months ended September 30, 2013 and 2012 (in thousands):
	September 30,			September 30,
	2013			2012
Accretable yield beginning balance	$	133,585		$	186,494
Reclassification from non-accretable difference	55,351			46,974
Reclassification to non-accretable difference	(5,234		)	(8,348		)
Accretion	(59,616		)	(76,252		)
Accretable yield ending balance	$	124,086		$	148,868
The accretable yield of $124.1 million at September 30, 2013 includes $1.4 million of accretable yield related to the loan pool that was put on non-accrual status during the nine months ended September 30, 2013. This accretable yield is not being accreted to income and its recognition will be deferred until full recovery of the carrying value of this pool is realized.
Below is the composition of the net book value for loans accounted for under ASC 310-30 at September 30, 2013 and December 31, 2012 (in thousands):
	September 30,			December 31,
	2013			2012
Contractual cash flows	$	1,075,652		$	1,444,279
Non-accretable difference	(426,101		)	(488,673		)
Non-accretable difference on retired pools	(12,455		)	—
Accretable yield	(124,086		)	(133,585		)
Loans accounted for under ASC 310-30	$	513,010		$	822,021

Allowance_for_Loan_Losses

Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Allowance for Loan Losses	'
	Allowance for Loan Losses
	The tables below detail the Company’s allowance for loan losses (“ALL”) and recorded investment in loans as of and for the three and nine months ended September 30, 2013 and 2012 (in thousands):
		Three months ended September 30, 2013
		Commercial			Commercial			Agriculture			Residential			Consumer			Total
					real estate						real estate
	Beginning balance	$	2,286		$	2,419		$	764		$	5,907		$	471		$	11,847
	Non 310-30 beginning balance	2,240			2,113			495			4,333			471			9,652
	Charge-offs	(401		)	—			—			(117		)	(276		)	(794		)
	Recoveries	92			17			—			23			75			207
	Provision	715			(205		)	27			27			186			750
	Non 310-30 ending balance	2,646			1,925			522			4,266			456			9,815
	ASC 310-30 beginning balance	46			306			269			1,574			—			2,195
	Charge-offs	—			—			(221		)	(57		)	—			(278		)
	Recoveries	—			—			—			—			—			—
	Provision	43			(8		)	537			(885		)	—			(313		)
	ASC 310-30 ending balance	89			298			585			632			—			1,604
	Ending balance	$	2,735		$	2,223		$	1,107		$	4,898		$	456		$	11,419
		Nine months ended September 30, 2013
		Commercial			Commercial			Agriculture			Residential			Consumer			Total
					real estate						real estate
	Beginning balance	$	2,798		$	7,396		$	592		$	4,011		$	583		$	15,380
	Non 310-30 beginning balance	2,798			3,056			323			4,011			540			10,728
	Charge-offs	(1,654		)	(943		)	—			(741		)	(717		)	(4,055		)
	Recoveries	187			129			13			64			224			617
	Provision	1,315			(317		)	186			932			409			2,525
	Non 310-30 ending balance	2,646			1,925			522			4,266			456			9,815
	ASC 310-30 beginning balance	—			4,340			269			—			43			4,652
	Charge-offs	(407		)	(2,796		)	(221		)	(623		)	—			(4,047		)
	Recoveries	—			—			—			—			—			—
	Provision	496			(1,246		)	537			1,255			(43		)	999
	ASC 310-30 ending balance	89			298			585			632			—			1,604
	Ending balance	$	2,735		$	2,223		$	1,107		$	4,898		$	456		$	11,419
	Ending allowance balance attributable to:
	Non 310-30 loans individually evaluated for impairment	$	92		$	40		$	1		$	533		$	7		$	673
	Non 310-30 loans collectively evaluated for impairment	2,554			1,885			521			3,733			449			9,142
	ASC 310-30 loans	89			298			585			632			—			1,604
	Total ending allowance balance	$	2,735		$	2,223		$	1,107		$	4,898		$	456		$	11,419
	Loans:
	Non 310-30 individually evaluated for impairment	$	7,670		$	11,258		$	223		$	9,629		$	295		$	29,075
	Non 310-30 collectively evaluated for impairment	264,444			277,494			117,241			513,531			28,018			1,200,728
	ASC 310-30 loans	68,250			325,701			37,882			72,409			8,768			513,010
	Total loans	$	340,364		$	614,453		$	155,346		$	595,569		$	37,081		$	1,742,813
		Three months ended September 30, 2012
		Commercial			Commercial			Agriculture			Residential			Consumer			Total
					real estate						real estate
	Beginning balance	$	3,318		$	7,797		$	660		$	4,872		$	647		$	17,294
	Non 310-30 beginning balance	1,725			3,578			284			3,813			635			10,035
	Charge-offs	(297		)	(35		)	—			(351		)	(566		)	(1,249		)
	Recoveries	279			(195		)	4			(47		)	(41		)	—
	Provision	842			(15		)	(22		)	274			521			1,600
	Non 310-30 ending balance	2,549			3,333			266			3,689			549			10,386
	ASC 310-30 beginning balance	1,593			4,219			376			1,059			12			7,259
	Charge-offs	(1		)	(3,500		)	(144		)	(169		)	—			(3,814		)
	Recoveries	—			2			—			—			—			2
	Provision	(1,592		)	6,012			—			(747		)	(10		)	3,663
	ASC 310-30 ending balance	—			6,733			232			143			2			7,110
	Ending balance	$	2,549		$	10,066		$	498		$	3,832		$	551		$	17,496
		Nine months ended September 30, 2012
		Commercial			Commercial			Agriculture			Residential			Consumer			Total
					real estate						real estate
	Beginning balance	$	2,959		$	3,389		$	282		$	4,121		$	776		$	11,527
	Non 310-30 beginning balance	1,597			3,389			154			3,423			776			9,339
	Charge-offs	(3,056		)	(2,448		)	(8		)	(815		)	(1,161		)	(7,488		)
Recoveries	279			24			4			49			252			608
Provision	3,729			2,368			116			1,032			682			7,927
Non 310-30 ending balance	2,549			3,333			266			3,689			549			10,386
ASC 310-30 beginning balance	1,362			—			128			698			—			2,188
Charge-offs	(216		)	(11,643		)	(144		)	(729		)	(19		)	(12,751		)
Recoveries	—			275			—			—			—			275
Provision	(1,146		)	18,101			248			174			21			17,398
ASC 310-30 ending balance	—			6,733			232			143			2			7,110
Ending balance	$	2,549		$	10,066		$	498		$	3,832		$	551		$	17,496
Ending allowance balance attributable to:
Non 310-30 loans individually evaluated for impairment	$	1,091		$	517		$	—		$	424		$	—		$	2,032
Non 310-30 loans collectively evaluated for impairment	1,458			2,816			266			3,265			549			8,354
ASC 310-30 loans	—			6,733			232			143			2			7,110
Total ending allowance balance	$	2,549		$	10,066		$	498		$	3,832		$	551		$	17,496
Loans:
Non 310-30 individually evaluated for impairment	$	11,586		$	18,067		$	178		$	7,532		$	193		$	37,556
Non 310-30 collectively evaluated for impairment	156,977			229,786			105,134			398,888			30,149			920,934
ASC 310-30 loans	97,664			664,771			55,944			126,294			26,363			971,036
Total loans	$	266,227		$	912,624		$	161,256		$	532,714		$	56,705		$	1,929,526
In evaluating the loan portfolio for an appropriate ALL level, non-impaired loans that were not accounted for under ASC 310-30 were grouped into segments based on broad characteristics such as primary use and underlying collateral. Within the segments, the portfolio was further disaggregated into classes of loans with similar attributes and risk characteristics for purposes of applying loss ratios and determining applicable subjective adjustments to the ALL. The application of subjective adjustments was based upon qualitative risk factors, including economic trends and conditions, industry conditions, asset quality, loss trends, lending management, portfolio growth and loan review/internal audit results.
The Company charged-off $0.6 million and $3.4 million, net of recoveries, of non 310-30 loans during the three and nine months ended September 30, 2013, respectively. The Company had previously provided specific reserves for $0.4 million and $1.7 million of the net charge-offs realized during the three and nine months ended September 30, 2013. Improvements in credit quality trends of the non 310-30 loan portfolio were seen in both past due and non-performing loans during the three and nine months ended September 30, 2013, and, through management's evaluation discussed above, resulted in a provision for loan losses on the non 310-30 loans of $0.8 million and $2.5 million, respectively.
During the nine months ended September 30, 2013, the Company re-estimated the expected cash flows of the loan pools accounted for under ASC 310-30 utilizing the same cash flow methodology used at the time of acquisition. The re-measurement resulted in a net reversal of impairment of $0.3 million and a net impairment of $1.0 million for the three and nine months ended September 30, 2013, respectively. During the three months ended September 30, 2013, the re-measurements resulted in a reversal of $0.9 million of impairment expense in the residential real estate segment and net impairments of $0.5 million in the agriculture segment. During the nine months ended September 30, 2013, the re-measurements resulted in a reversal of previous valuation allowances of $1.2 million in the commercial real estate segment and net impairments of $1.3 million, $0.5 million and $0.5 million in the residential real estate, agriculture, and commercial segments, respectively.
During the three and nine months ended September 30, 2012, the Company's re-measurement of expected future cash flows of ASC 310-30 loans resulted in impairments of $3.7 million and $17.4 million, respectively. The commercial real estate pool was the primary contributor to the total impairment with impairments of $6.0 million and $18.1 million for the three and nine months ended September 30, 2012, respectively. As a result of gross cash flow improvements during the three and nine months ended September 30, 2012, the re-measurements resulted in a reversal of $1.6 million and $1.1 million, respectively, of impairment expense in the commercial segment.
During the three and nine months ended September 30, 2012, the Company recorded $1.6 million and $7.9 million, respectively, of provision for loan losses for loans not accounted for under ASC 310-30 primarily to provide for changes in credit risk inherent in new loan originations and provide for charge-offs. The Company charged off $6.9 million, net of recoveries, of non 310-30 loans during the nine months ended September 30, 2012, $2.4 million of which was the result of a large commercial and industrial loan that was not considered indicative of future charge-offs in the commercial and industrial loan category. The Company also charged off $2.4 million of commercial real estate loans, primarily the result of three commercial real estate loans outside of the core market areas totaling $2.1 million.

FDIC_Indemnification_Asset

FDIC Indemnification Asset	9 Months Ended
	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'
FDIC Indemnification Asset	'
	FDIC Indemnification Asset
	Under the terms of the purchase and assumption agreement with the FDIC with regard to the Hillcrest Bank and Community Banks of Colorado acquisitions, the Company is reimbursed for a portion of the losses incurred on covered assets. As covered assets are resolved, whether it be through repayment, short sale of the underlying collateral, the foreclosure on and sale of collateral, or the sale or charge-off of loans or OREO, any differences between the carrying value of the covered assets versus the payments received during the resolution process, that are reimbursable by the FDIC, are recognized in the consolidated statements of operations as FDIC loss sharing income. Any gains or losses realized from the resolution of covered assets reduce or increase, respectively, the amount recoverable from the FDIC.
	Below is a summary of the activity related to the FDIC indemnification asset during the nine months ended September 30, 2013 and 2012 (in thousands):
		For the nine months ended
		September 30,			September 30,
		2013			2012
	Balance at beginning of period	$	86,923		$	223,402
	Accretion	(11,843		)	(9,165		)
	FDIC portion of charge-offs exceeding fair value marks	7,466			8,100
	Reduction for claims filed	(24,460		)	(109,142		)
	Balance at end of period	$	58,086		$	113,195
	During the nine months ended September 30, 2013, the Company recognized $11.8 million of negative accretion on the FDIC indemnification asset, and reduced the carrying value of the FDIC indemnification asset by $24.5 million as a result of claims filed with the FDIC. The negative accretion resulted from an overall increase in actual and expected cash flows on the underlying covered assets, resulting in lower expected reimbursements from the FDIC. The increase in overall expected cash flows from these underlying assets is reflected in increased accretion rates on covered loans and is being recognized over the expected remaining lives of the underlying covered loans as an adjustment to yield. The loss claims filed are subject to review and approval, including extensive audits, by the FDIC or its assigned agents for compliance with the terms in the loss sharing agreements. During the nine months ended September 30, 2013, the Company received $77.0 million in payments from the FDIC.
	During the nine months ended September 30, 2012, the Company recognized $9.2 million of negative accretion on the FDIC indemnification asset, and reduced the carrying value of the FDIC indemnification asset by $109.1 million as a result of claims filed with the FDIC.

Other_Real_Estate_Owned

Other Real Estate Owned	9 Months Ended
	Sep. 30, 2013
Banking and Thrift [Abstract]	'
Other Real Estate Owned	'
	Other Real Estate Owned
	A summary of the activity in the OREO balances during the nine months ended September 30, 2013 and 2012 is as follows (in thousands):
		For the nine months ended September 30,
		2013			2012
	Beginning balance	$	94,808		$	120,636
	Transfers from loan portfolio, at fair value	32,408			67,741
	Impairments	(9,142		)	(8,638		)
	Sales	(54,705		)	(57,186		)
	Gain on sale of OREO, net	7,384			6,792
	Ending balance	$	70,753		$	129,345
	The OREO balances include the interests of several outside participating banks totaling $3.8 million at September 30, 2013 and $5.3 million at December 31, 2012, for which an offsetting liability is recorded in other liabilities. It excludes $10.6 million, for both of the respective periods, of the Company’s minority interests in OREO which are held by outside banks where the Company was not the lead bank and does not have a controlling interest, for which the Company maintains a receivable in other assets.
	Of the $70.8 million of OREO at September 30, 2013, $44.1 million, or 62.3%, was covered by loss sharing agreements with the FDIC. Any losses on these assets are substantially offset by a corresponding change in the FDIC indemnification asset. During the nine months ended September 30, 2013, the Company sold $54.7 million of OREO and realized net gains on these sales of $7.4 million.
	Of the $129.3 million of OREO at September 30, 2012, $64.5 million, or 49.9%, was covered by the loss sharing agreements with the FDIC. During the nine months ended September 30, 2012, the Company sold $57.2 million of OREO and realized net gains on these sales of $6.8 million.

Deposits

Deposits	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Deposits	'
	Deposits
	As of September 30, 2013 and December 31, 2012, deposits totaled $4.0 billion and $4.2 billion, respectively. Time deposits decreased from $1.8 billion at December 31, 2012 to $1.5 billion at September 30, 2013. The following table summarizes the Company’s time deposits, based upon contractual maturity, at September 30, 2013 and December 31, 2012, by remaining maturity (in thousands):
		September 30, 2013				December 31, 2012
		Balance		Weighted		Balance			Weighted
				Average					Average
				Rate					Rate
	Three months or less	$	341,794	0.58	%	$	356,446		0.78	%
	Over 3 months through 6 months	343,463		0.58	%	259,097			0.68	%
	Over 6 months through 12 months	438,725		0.57	%	583,209			0.67	%
	Over 12 months through 24 months	289,159		0.95	%	373,283			0.88	%
	Over 24 months through 36 months	72,360		1.66	%	111,599			1.77	%
	Over 36 months through 48 months	27,653		1.51	%	43,967			1.83	%
	Over 48 months through 60 months	16,275		1.33	%	19,278			1.44	%
	Thereafter	4,961		1.69	%	5,839			2.32	%
	Total time deposits	$	1,534,390	0.72	%	$	1,752,718		0.85	%
	In connection with the Company’s FDIC-assisted transactions, the FDIC provided Hillcrest Bank, Bank of Choice and Community Banks of Colorado depositors with the right to redeem their time deposits at any time during the life of the time deposit, without penalty, unless the depositor accepts new terms. At September 30, 2013 and December 31, 2012, the Company had approximately $82.6 million and $164.3 million, respectively, of time deposits that were subject to penalty-free withdrawals.
	The Company incurred interest expense on deposits as follows during the periods indicated (in thousands):
		For the three months ended					For the nine months ended
		September 30, 2013		September 30, 2012			September 30, 2013			September 30, 2012
	Interest bearing demand deposits	$	157	$	271		$	536		$	1,007
	Money market accounts	872		1,005			2,534			3,076
	Savings accounts	56		65			170			226
	Time deposits	2,880		5,178			9,407			19,713
	Total	$	3,965	$	6,519		$	12,647		$	24,022

Regulatory_Capital

Regulatory Capital	9 Months Ended
	Sep. 30, 2013
Banking and Thrift [Abstract]	'
Regulatory Capital	'
	Regulatory Capital
	At September 30, 2013 and December 31, 2012, as applicable, NBH Bank, N.A. and the consolidated holding company exceeded all capital ratio requirements under prompt corrective action or other regulatory requirements, as is detailed in the table below (in thousands):
		September 30, 2013
		Actual				Required to be				Required to be
						considered well				considered
						capitalized (1)				adequately
										capitalized
		Ratio		Amount		Ratio		Amount		Ratio		Amount
	Tier 1 leverage ratio
	Consolidated	18.5	%	$	948,196	N/A		N/A		4	%	$	205,349
	NBH Bank, N.A.	17.1	%	865,682		10	%	$	507,279	4	%	202,912
	Tier 1 risk-based capital ratio (2)
	Consolidated	48	%	$	948,196	6	%	$	118,619	4	%	$	79,079
	NBH Bank, N.A.	44.3	%	865,682		11	%	214,800		4	%	78,109
	Total risk-based capital ratio (2)
	Consolidated	48.6	%	$	960,415	10	%	$	197,698	8	%	$	158,158
	NBH Bank, N.A.	45	%	877,901		12	%	234,328		8	%	156,218
		December 31, 2012
		Actual				Required to be				Required to be
						considered well				considered
						capitalized (1)				adequately
										capitalized
		Ratio		Amount		Ratio		Amount		Ratio		Amount
	Tier 1 leverage ratio
	Consolidated	18.2	%	$	962,779	N/A		N/A		4	%	$	211,439
	NBH Bank, N.A.	16.4	%	851,365		10	%	$	518,244	4	%	207,298
	Tier 1 risk-based capital ratio (2)
	Consolidated	51.9	%	$	962,779	6	%	$	111,396	4	%	$	74,264
	NBH Bank, N.A.	46.6	%	851,365		11	%	201,147		4	%	73,144
	Total risk-based capital ratio (2)
	Consolidated	52.7	%	$	978,535	10	%	$	185,659	8	%	$	148,527
	NBH Bank, N.A.	47.4	%	867,121		12	%	219,433		8	%	146,289
	-1	These ratio requirements are reflective of the agreements the Company has made with its various regulators in connection with the approval of the de novo charter for NBH Bank, N.A., as described above.
	-2	Due to the conditional guarantee represented by the loss sharing agreements, the FDIC indemnification asset and covered assets are risk-weighted at 20% for purposes of risk-based capital computations.

FDIC_Loss_Sharing_Income

FDIC Loss Sharing Income	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
FDIC Loss Sharing Income	'
	FDIC Loss Sharing Income (Expense)
	In connection with the loss sharing agreements that the Company has with the FDIC with regard to the Hillcrest Bank and Community Banks of Colorado transactions, the Company recognizes the actual reimbursement of costs of resolution of covered assets from the FDIC through the statements of operations. The table below provides additional details of the Company’s FDIC loss sharing income (expense) during the three and nine months ended September 30, 2013 and 2012 (in thousands):
		For the three months ended						For the nine months ended
		September 30, 2013			September 30, 2012			September 30, 2013			September 30, 2012
	Clawback liability amortization	$	(314	)	$	(355	)	$	(937	)	$	(1,066	)
	Clawback liability remeasurement	(405		)	(820		)	244			247
	Reimbursement to FDIC for gain on sale of and income from covered OREO	(2,514		)	(1,842		)	(4,615		)	(1,408		)
	Reimbursement to FDIC for recoveries	—			(2		)	(22		)	(3		)
	FDIC reimbursement of costs of resolution of covered assets	2,042			4,522			8,608			11,508
	Total	$	(1,191	)	$	1,503		$	3,278		$	9,278

Stockbased_Compensation_and_Em

Stock-based Compensation and Employee Benefits	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Stock-based Compensation and Employee Benefits	'
	Stock-based Compensation and Employee Benefits
	The Company issued stock options in accordance with the NBH Holdings Corp. 2009 Equity Incentive Plan (the “Plan”) during the nine months ended September 30, 2013. These option awards vest on a graded basis over 1-4 years of continuous service and have 10-year contractual terms. The expense associated with the awarded stock options was measured at fair value using a Black-Scholes option-pricing model using the following weighted average assumptions:
		Black-Scholes
	Risk-free interest rate	1.15	%
	Expected volatility	32.07	%
	Expected term (years)	6.7
	Dividend yield	1.09	%
	Expected volatility was calculated using a time-based weighted migration of the Company’s own stock price volatility coupled with those of a peer group of 9 comparable publicly traded companies for a period commensurate with the expected term of the options. The risk-free rate for the expected term of the options was based on the U.S. Treasury yield curve at the date of grant and based on the expected term. The expected term was estimated to be the average of the contractual vesting term and time to expiration. The dividend yield was assumed to be $0.05 per share per quarter. Options granted during the nine months ended September 30, 2013 had weighted average grant date fair values of $5.54 per share.
	The following table summarizes option activity for the nine months ended September 30, 2013:
		Options		Weighted		Weighted	Aggregate
				Average		Average	Intrinsic
				Exercise		Remaining	Value
				Price		Contractual
						Term in
						Years
	Outstanding at December 31, 2012	3,471,665		$	19.98	6.94	$	22,800
	Granted during the nine months ended September 30, 2013	174,750		18.62
	Forfeited	(47,570	)	19.35
	Expired	(60,833	)	20
	Exercised	—		—
	Outstanding at September 30, 2013	3,538,012		$	19.92	6.37	$	2,238,176
	Options fully vested and exercisable at September 30, 2013	2,602,082		$	20	6.19	$	—
	Options expected to vest	933,800		$	19.74	6.43	$	2,111,363
	Stock option expense is included in salaries and employee benefits in the accompanying consolidated statements of operations and totaled $0.5 million and $3.9 million for the three months ended September 30, 2013 and 2012, respectively, and $1.8 million and $5.9 million for the nine months ended September 30, 2013 and 2012, respectively. At September 30, 2013, there was $1.8 million of total unrecognized compensation cost related to non-vested stock options granted under the Plan. The cost is expected to be recognized over a weighted average period of 0.9 years.
	Expense related to non-vested restricted stock totaled $0.8 million and $2.7 million during the three months ended September 30, 2013 and 2012, respectively, and $2.2 million and $5.0 million during the nine months ended September 30, 2013 and 2012, respectively, and is included in salaries and employee benefits in the Company’s consolidated statements of operations. As of September 30, 2013, there was $2.3 million of total unrecognized compensation cost related to non-vested restricted shares granted under the Plan, which is expected to be recognized over a weighted average period of 1.1 years. The following table summarizes restricted stock activity for the nine months ended September 30, 2013:
		Total Restricted Shares		Weighted Average Grant-Date Fair Value
	Unvested at December 31, 2012	951,668		14.79
	Granted	146,218		18.25
	Forfeited	(10,732	)	18.09
	Unvested at September 30, 2013	1,087,154		15.22

Common_Stock

Common Stock	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Common Stock	'
	Common Stock
	The Company had 45,245,425 shares of Class A common stock and 5,967,619 shares of Class B common stock outstanding as of September 30, 2013 and 46,368,483 shares of Class A common stock and 5,959,189 shares of Class B common stock outstanding as of December 31, 2012. Additionally, as of September 30, 2013 and December 31, 2012, the Company had 1,087,154 and 951,668 shares, respectively, of restricted Class A common stock issued but not yet vested under the NBH Holdings Corp. 2009 Equity Incentive Plan. Class A common stock possesses all of the voting power for all matters requiring action by holders of common stock, with certain limited exceptions. The Company’s certificate of incorporation provides that, except with respect to voting rights and conversion rights, the Class A common stock and Class B non-voting common stock are treated equally and identically.

Income_Per_Share

Income Per Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Income Per Share	'
	Income Per Share
	The Company calculates income per share under the two-class method, as certain non-vested share awards contain nonforfeitable rights to dividends. As such, these awards are considered securities that participate in the earnings of the Company. Non-vested shares are discussed further in note 11.
	The Company had 51,213,044 and 52,191,239 shares outstanding (inclusive of Class A and B) as of September 30, 2013 and 2012, respectively. Additional information regarding share activity subsequent to September 30, 2013 can be found in note 18. Certain stock options and non-vested restricted shares are potentially dilutive securities, but are not included in the calculation of diluted earnings per share because to do so would have been anti-dilutive for three and nine months ended September 30, 2013 and 2012, respectively.
	The following table illustrates the computation of basic and diluted income per share for the three and nine months ended September 30, 2013 and 2012 (in thousands, except share and earnings per share information):
		For the three months ended						For the nine months ended
		September 30,						September 30,
		2013			2012			2013			2012
	Distributed earnings	$	2,622		$	—		$	7,934		$	—
	Undistributed earnings (distributions in excess of earnings)	(1,675		)	(7,891		)	(2,007		)	(3,546		)
	Net income (loss)	$	947		$	(7,891	)	$	5,927		$	(3,546	)
	Less: earnings allocated to participating securities	(5		)	—			(12		)	—
	Earnings allocated to common stockholders	$	942		$	(7,891	)	$	5,915		$	(3,546	)
	Weighted average shares outstanding for basic earnings per common share	51,454,200			52,191,239			51,940,245			52,186,465
	Dilutive effect of equity awards	45,301			—			32,916			—
	Dilutive effect of warrants	2,479			—			—			—
	Weighted average shares outstanding for diluted earnings per common share	51,501,980			52,191,239			51,973,161			52,186,465
	Basic earnings (loss) per share	$	0.02		$	(0.15	)	$	0.11		$	(0.07	)
	Diluted earnings (loss) per share	$	0.02		$	(0.15	)	$	0.11		$	(0.07	)
	The Company had 3,538,012 and 3,443,332 outstanding stock options to purchase common stock at weighted average exercise prices of $19.92 and $20.00 per share at September 30, 2013 and 2012, respectively, which have time-vesting criteria, and as such, any dilution is derived only for the time frame in which the vesting criteria had been met and where the inclusion of those stock options is dilutive. Additionally, the Company had 830,750 outstanding warrants to purchase the Company’s common stock as of September 30, 2013 and 2012. The warrants have an exercise price of $20.00, which was out-of-the-money for purposes of dilution calculations during both the nine months ended September 30, 2013 and the three and nine months ended September 30, 2012. The Company had 1,087,154 and 1,169,792 unvested restricted shares outstanding as of September 30, 2013 and 2012, respectively, which have performance, market and time-vesting criteria, and as such, any dilution is derived only for the time frame in which the vesting criteria had been met and where the inclusion of those restricted shares is dilutive

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivatives	'
	Derivatives
	The Company manages economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of its assets and liabilities. During the nine months ended September 30, 2013, the Company began entering into interest rate swaps. The Company’s existing interest rate derivatives result from a service provided to certain qualifying clients in the extension of credit and, therefore, are not used to manage interest rate risk in the Company’s assets or liabilities. The Company manages a matched book with respect to its derivative instruments whereby it enters into offsetting swaps in order to minimize its net risk exposure resulting from such transactions. The Company’s swap derivatives are not designated as hedging relationships, and do not meet the strict hedge accounting requirements. Accordingly, changes in the fair value of both the client swaps and the offsetting swaps are recognized directly in earnings. At September 30, 2013, the Company had entered into one matched interest rate swap transaction with a notional amount of $2.1 million and a fair value of $83.0 thousand. Under this arrangement, the client pays the Company a fixed rate of 5.75%, while the Company pays the client a LIBOR rate plus 275 basis points.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	The Company uses fair value measurements to record fair value adjustments to certain assets and liabilities and to disclose the fair value of its financial instruments. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. For disclosure purposes, the Company groups its financial and non-financial assets and liabilities into three different levels based on the nature of the instrument and the availability and reliability of the information that is used to determine fair value. The three levels are defined as follows:
	•	Level 1—Includes assets or liabilities in which the inputs to the valuation methodologies are based on unadjusted quoted prices in active markets for identical assets or liabilities.
	•	Level 2—Includes assets or liabilities in which the inputs to the valuation methodologies are based on similar assets or liabilities in inactive markets, quoted prices for identical or similar assets or liabilities in inactive markets, and inputs other than quoted prices that are observable, such as interest rates, yield curves, volatilities, prepayment speeds, and other inputs obtained from observable market input.
	•	Level 3—Includes assets or liabilities in which the inputs to the valuation methodology are based on at least one significant assumption that is not observable in the marketplace. These valuations may rely on management’s judgment and may include internally-developed model-based valuation techniques.
	Level 1 inputs are considered to be the most transparent and reliable and level 3 inputs are considered to be the least transparent and reliable. The Company assumes the use of the principal market to conduct a transaction of each particular asset or liability being measured and then considers the assumptions that market participants would use when pricing the asset or liability. Whenever possible, the Company first looks for quoted prices for identical assets or liabilities in active markets (level 1 inputs) to value each asset or liability. However, when inputs from identical assets or liabilities on active markets are not available, the Company utilizes market observable data for similar assets and liabilities. The Company maximizes the use of observable inputs and limits the use of unobservable inputs to occasions when observable inputs are not available. The need to use unobservable inputs generally results from the lack of market liquidity of the actual financial instrument or of the underlying collateral. Although, in some instances, third party price indications may be available, limited trading activity can challenge the observability of these quotations.
	Changes in the valuation inputs used for measuring the fair value of financial instruments may occur due to changes in current market conditions or other factors. Such changes may necessitate a transfer of the financial instruments to another level in the hierarchy based on the new inputs used. The Company recognizes these transfers at the end of the reporting period that the transfer occurs. During the nine months ended September 30, 2013 and 2012, there were no transfers of financial instruments between the hierarchy levels.
	The following is a description of the valuation methodologies used for assets and liabilities measured at fair value, as well as the general classification of each instrument under the valuation hierarchy:
	Fair Value of Financial Instruments Measured on a Recurring Basis
	Investment securities available-for-sale—Investment securities available-for-sale are carried at fair value on a recurring basis. To the extent possible, observable quoted prices in an active market are used to determine fair value and, as such, these securities are classified as level 1. At December 31, 2012 the Company classified its U.S. Treasury securities as level 1 in the fair value hierarchy. At September 30, 2013 the Company did not hold U.S. Treasury securities. When quoted market prices in active markets for identical assets or liabilities are not available, quoted prices of securities with similar characteristics, discounted cash flows or other pricing characteristics are used to estimate fair values and the securities are then classified as level 2. At September 30, 2013 and December 31, 2012, the Company’s level 2 securities included asset backed securities, mortgage-backed securities comprised of residential mortgage pass-through securities, and other residential mortgage-backed securities. All other investment securities are classified as level 3. There were no transfers between levels 1, 2 or 3 during the nine months ended September 30, 2013 or 2012.
	Warrant liability—The Company measures the fair value of the warrant liability on a recurring basis using a Black-Scholes option pricing model. The Company’s shares became publicly traded on September 20, 2012 and prior to that, had limited private trading; therefore, expected volatility was estimated based on the median historical volatility, for a period commensurate with the expected term of the warrants, of 9 comparable companies with publicly traded shares, and is deemed a significant unobservable input to the valuation model.
	Clawback liability—The Company periodically measures the net present value of expected future cash payments to be made by the Company to the FDIC that must be made within 45 days of the conclusion of the loss sharing. The expected cash flows are calculated in accordance with the loss sharing agreements and are based primarily on the expected losses on the covered assets, which involve significant inputs that are not market observable.
	The tables below present the financial instruments measured at fair value on a recurring basis as of September 30, 2013 and December 31, 2012 on the consolidated statements of financial condition utilizing the hierarchy structure described above (in thousands):
		September 30, 2013
		Level 1		Level 2			Level 3		Total
	Assets:
	Investment securities available-for-sale:
	Asset backed securities	$	—	$	20,098		$	—	$	20,098
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	—		523,183			—		523,183
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	—		1,346,262			—		1,346,262
	Other securities	—		—			419		419
	Total assets at fair value	$	—	$	1,889,543		$	419	$	1,889,962
	Liabilities:
	Warrant liability	$	—	$	—		$	5,599	$	5,599
	Clawback liability	—		—			31,964		31,964
	Total liabilities at fair value	$	—	$	—		$	37,563	$	37,563
		December 31, 2012
		Level 1		Level 2			Level 3		Total
	Assets:
	Investment securities available-for-sale:
	U.S. Treasury securities	$	300	$	—		$	—	$	300
	Asset backed securities	—		90,003			—		90,003
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	—		678,017			—		678,017
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	—		949,289			—		949,289
	Other securities	—		—			419		419
	Total assets at fair value	$	300	$	1,717,309		$	419	$	1,718,028
	Liabilities:
	Warrant liability	$	—	$	—		$	5,461	$	5,461
	Clawback liability	—		—			31,271		31,271
	Total liabilities at fair value	$	—	$	—		$	36,732	$	36,732
	The table below details the changes in level 3 financial instruments during the nine months ended September 30, 2013 (in thousands):
		Warrant		Clawback
		liability		liability
	Balance at December 31, 2012	$	5,461	$	31,271
	Change in value	138		(244		)
	Accretion	—		937
	Settlement	—		—
	Net change in Level 3	138		693
	Balance at September 30, 2013	$	5,599	$	31,964
	Fair Value of Financial Instruments Measured on a Non-recurring Basis
	Certain assets may be recorded at fair value on a non-recurring basis as conditions warrant. These non-recurring fair value measurements typically result from the application of lower of cost or fair value accounting or a write-down occurring during the period.
	The Company records collateral dependent loans that are considered to be impaired at their estimated fair value. A loan is considered impaired when it is probable that the Company will be unable to collect all contractual amounts due in accordance with the terms of the loan agreement. Collateral dependent impaired loans are measured based on the fair value of the collateral. The Company relies on third-party appraisals and internal assessments in determining the estimated fair values of these loans. The inputs used to determine the fair values of loans are considered level 3 inputs in the fair value hierarchy. During the nine months ended September 30, 2013, the Company measured 28 loans not accounted for under ASC 310-30 at fair value on a non-recurring basis. These loans carried specific reserves totaling $0.6 million at September 30, 2013. During the nine months ended September 30, 2013, the Company added specific reserves of $0.6 million for eleven loans with carrying balances of $10.0 million at September 30, 2013. The Company also eliminated specific reserves of $1.9 million for twenty-seven loans during the nine months ended September 30, 2013, primarily due to paydowns on these loans.
	The Company may be required to record fair value adjustments on loans held-for-sale on a non-recurring basis. The non-recurring fair value adjustments could involve lower of cost or fair value accounting and may include write-downs.
	OREO is recorded at the lower of the loan balance or the fair value of the collateral less estimated selling costs. The estimated fair values of OREO are updated periodically and further write-downs may be taken to reflect a new basis. The Company recognized $9.0 million of OREO impairments in its consolidated statements of financial condition during the nine months ended September 30, 2013, of which $6.6 million, or 73.2% , were on OREO that was covered by loss sharing agreements with the FDIC. The fair values of OREO are derived from third party price opinions or appraisals that generally use an income approach or a market value approach. If reasonable comparable appraisals are not available, then the Company may use internally developed models to determine fair values. The inputs used to determine the fair values of OREO are considered level 3 inputs in the fair value hierarchy.
	The table below provides information regarding the assets recorded at fair value on a non-recurring basis during the nine months ended September 30, 2013 (in thousands):
		September 30, 2013
		Level 1		Level 2			Level 3		Total		Losses
											From
											Fair
											Value
											Changes
Other real estate owned	$	—	$	—		$	70,753	$	70,753	$	9,049
Impaired loans	$	—	$	—		$	29,075	$	29,075	$	1,305
The Company did not record any liabilities for which the fair value was made on a non-recurring basis during the nine months ended September 30, 2013.
The following table provides information about the valuation techniques and unobservable inputs used in the valuation of financial instruments falling within level 3 of the fair value hierarchy as of September 30, 2013. The table below excludes non-recurring fair value measurements of collateral value used for impairment measures for OREO. These valuations utilize third party appraisal or broker price opinions, and are classified as level 3 due to the significant judgment involved (in thousands):
	Fair Value at		Valuation Technique		Unobservable Input	Quantitative
	September 30,					Measures
	2013
Other securities	$	419	Cash investment in private equity fund		Cash investment
Impaired loans	29,075		Appraised value		Appraised values
					Discount rate	0-25%
Clawback liability	31,964		Contractually defined discounted cash flows		Intrinsic loss estimates	$323.3 million -
						$405 million
					Expected credit losses	—
						$98 million-$182.7 million
					Asset purchase premium
					Discount rate	4%
					Discount period	73-85 months
Warrant liability	5,599		Black-Scholes		Volatility	16%-49%

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	Fair Value of Financial Instruments
	The fair value of a financial instrument is the amount that would be exchanged between willing parties, other than in a forced liquidation. Fair value is determined based upon quoted market prices to the extent possible; however, in many instances, there are no quoted market prices for the Company’s various financial instruments. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques that may be significantly impacted by the assumptions used, including the discount rate and estimates of future cash flows. Changes in any of these assumptions could significantly affect the fair value estimates. The fair value of the financial instruments listed below does not reflect a premium or discount that could result from offering all of the Company’s holdings of financial instruments at one time, nor does it reflect the underlying value of the Company, as ASC Topic 825 excludes certain financial instruments and all non-financial instruments from its disclosure requirements. In connection with the Hillcrest Bank, Bank Midwest, Bank of Choice and Community Banks of Colorado acquisitions, the Company recorded all of the acquired assets and assumed liabilities at fair value at the respective dates of acquisition. The fair value of financial instruments at September 30, 2013 and December 31, 2012, including methods and assumptions utilized for determining fair value of financial instruments, are set forth below (in thousands):
			30-Sep-13				31-Dec-12
		Level in Fair	Carrying		Estimated		Carrying		Estimated
		Value	Amount		Fair Value		Amount		Fair Value
		Measurement
		Hierarchy
	ASSETS:
	Cash and cash equivalents	Level 1	$	349,244	$	349,244	$	769,180	$	769,180
	Securities purchased under agreements to resell	Level 2	75,000		75,016		—		—
	U.S. Treasury securities available-for-sale	Level 1	—		—		300		300
	Asset backed securities available-for-sale	Level 2	20,098		20,098		90,003		90,003
	Mortgage-backed securities—residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises available-for-sale	Level 2	523,183		523,183		678,017		678,017
	Mortgage-backed securities—other residential mortgage-backed securities issued or guaranteed by U.S. Government agencies or sponsored enterprises available-for-sale	Level 2	1,346,262		1,346,262		949,289		949,289
	Other securities	Level 3	419		419		419		419
	Mortgage-backed securities—residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	Level 2	530,406		533,464		577,486		584,551
	Mortgage-backed securities—other residential mortgage-backed securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	Level 2	134,311		131,114		—		—
	Capital stock of FHLB	Level 2	6,705		6,705		7,976		7,976
	Capital stock of FRB	Level 2	25,020		25,020		25,020		25,020
	Loans receivable, net	Level 3	1,731,394		1,742,595		1,817,322		1,829,987
	Loans held-for-sale	Level 2	5,265		5,265		5,368		5,368
	Accrued interest receivable	Level 2	11,670		11,670		12,673		12,673
	LIABILITIES:
	Deposit transaction accounts	Level 2	2,417,113		2,417,113		2,448,001		2,448,001
	Time deposits	Level 2	1,534,390		1,538,608		1,752,718		1,759,886
	Securities sold under agreements to repurchase	Level 2	116,471		116,471		53,685		53,685
	Due to FDIC	Level 3	31,964		31,964		31,271		31,271
	Warrant liability	Level 3	5,599		5,599		5,461		5,461
	Accrued interest payable	Level 2	3,225		3,225		4,239		4,239
	Cash and cash equivalents
	Cash and cash equivalents have a short-term nature and the estimated fair value is equal to the carrying value.
	Securities purchased under agreements to resell
	The fair value of securities purchased under agreements to resell is estimated by discounting contractual maturities utilizing current market rates for similar instruments.
	Investment securities
	The estimated fair value of investment securities is based on quoted market prices or bid quotations received from securities dealers. Other investment securities, including securities that are held for regulatory purposes are carried at cost, less any other than temporary impairment.
	Loans receivable
	The estimated fair value of the loan portfolio is estimated using a discounted cash flow analysis using a discount rate based on interest rates offered at the respective measurement dates for loans with similar terms to borrowers of similar credit quality. The allowance for loan losses is considered a reasonable estimate of any required adjustment to fair value to reflect the impact of credit risk. The estimates of fair value do not incorporate the exit-price concept prescribed by ASC Topic 820 Fair Value Measurements and Disclosures.
	Loans held-for-sale
	Loans held-for-sale are carried at the lower of aggregate cost or estimated fair value. The portfolio consists primarily of fixed rate residential mortgage loans that are sold within 45 days. The estimated fair value is based on quoted market prices for similar loans in the secondary market and are classified as level 2.
	Accrued interest receivable
	Accrued interest receivable has a short-term nature and the estimated fair value is equal to the carrying value.
	Deposits
	The estimated fair value of deposits with no stated maturity, such as non-interest bearing demand deposits, savings, NOW accounts, and money market accounts, is equal to the amount payable on demand. The fair value of interest-bearing time deposits is based on the discounted value of contractual cash flows of such deposits, taking into account the option for early withdrawal. The discount rate is estimated using the rates offered by the Company, at the respective measurement dates, for deposits of similar remaining maturities.
	Securities sold under agreements to repurchase
	The vast majority of the Company’s repurchase agreements are overnight transactions that mature the day after the transaction, and as a result of this short-term nature, the estimated fair value is equal to the carrying value.
	Due to FDIC
	The amount due to FDIC is specified in the purchase agreements and, as it relates to the clawback liability, is discounted to reflect the uncertainty in the timing and payment of the amount due by the Company.
	Warrant liability
	The warrant liability is estimated using a Black-Scholes model, the assumptions of which are detailed in note 19 of our audited consolidated financial statements.
	Accrued interest payable
	Accrued interest payable has a short-term nature and the estimated fair value is equal to the carrying value.

Banking_Center_Closures

Banking Center Closures	9 Months Ended
	Sep. 30, 2013
Restructuring and Related Activities [Abstract]	'
Banking Center Closures	'
	Banking Center Closures
	On September 30, 2013, the Company announced plans to integrate 32 limited-service retirement center locations (acquired in its 2010 purchase of Hillcrest Bank) and exit four banking centers in Northern California (acquired in its 2011 purchase of Community Banks of Colorado). The affected centers are expected to close by December 31, 2013. Included in the three and nine months ended September 30, 2013 operating results are $3.4 million of expenses incurred in connection with the closures, including $3.3 million related to facilities expense, which are included in the Banking center closure related expenses line on the consolidated statement of operations in the accompanying financial statements. Valuation adjustments to banking center properties and fixed assets were based on prices for similar assets and account for $2.5 million of the facilities expense and $0.8 million of the facilities expense relates to lease costs. No additional material charges or future cash expenditures are expected at this time.
	As of September 30, 2013, the impacted centers had $0.2 million loans outstanding, the limited-service retirement center locations had $94.0 million in total deposits and the California banking centers had $65.8 million in total deposits.

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]	'
Subsequent Events	'
	Subsequent Events
	In October 2013, NBH Bank, N.A. received approval and a waiver from the OCC under the Operating Agreement to permanently reduce the bank's capital by $313.0 million. As a result, the bank paid a $313.0 million cash dividend to the Company.
	On November 1, 2013, the Company repurchased 5,015,000 shares of its common stock, including 2,175,155 shares of Class A common stock and 2,839,845 shares of Class B nonvoting common stock, together representing approximately 9.8% of its outstanding shares, from an institutional stockholder.  The repurchase price of $20.00 per share resulted in a total transaction value of approximately $100.3 million.  On November 7, 2013, the Company repurchased 756,126 shares of Class A common stock, representing approximately 1.6% of its outstanding shares, from an institutional stockholder. The repurchase price of $20.00 per share resulted in a total transaction value of approximately $15.1 million. These repurchases were exclusive of and separate from the previously announced stock repurchase program in November 2012.

Recent_Accounting_Pronouncemen1

Recent Accounting Pronouncements (Policies)	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income	'
	Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income—In February 2013, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2013-02, Comprehensive Income-Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. This guidance requires entities to provide information about the amounts reclassified out of accumulated other comprehensive income by component. Entities are also required to present significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income, but only if the amount reclassified is required to be reclassified to net income in its entirety in the same accounting period. Other amounts that are not required to be reclassified to net income are to be cross-referenced to other disclosures that provide additional detail about those amounts. The Company was required to adopt this update in 2013 with retrospective application. Adoption of this update affects the presentation of the components of comprehensive income in the Company’s financial statements, but did not have an impact on the Company’s consolidated statements of financial condition, results of operations or liquidity.

Investment_Securities_Tables

Investment Securities - (Tables)	9 Months Ended
	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'
Summary of Available-for-Sale Investment Securities	'
	Available-for-sale investment securities are summarized as follows as of the dates indicated (in thousands):
		September 30, 2013
		Amortized		Gross			Gross			Fair Value
		Cost		Unrealized			Unrealized
				Gains			Losses
	Asset backed securities	$	20,091	$	7		$	—		$	20,098
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	514,584		9,525			(926		)	523,183
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	1,376,453		11,211			(41,402		)	1,346,262
	Other securities	419		—			—			419
	Total	$	1,911,547	$	20,743		$	(42,328	)	$	1,889,962
		December 31, 2012
		Amortized		Gross			Gross			Fair Value
		Cost		Unrealized			Unrealized
				Gains			Losses
	U.S. Treasury securities	$	300	$	—		$	—		$	300
	Asset backed securities	89,881		122			—			90,003
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	658,169		19,849			(1		)	678,017
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	931,979		17,630			(320		)	949,289
	Other securities	419		—			—			419
	Total	$	1,680,748	$	37,601		$	(321	)	$	1,718,028
Summary of Unrealized Losses	'
	The table below summarizes the unrealized losses as of the dates shown, along with the length of the impairment period (in thousands):
		September 30, 2013
		Less than 12 months					12 months or more						Total
		Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Losses			Value			Losses			Value		Losses
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	212,138	$	(925	)	$	14		$	(1	)	$	212,152	$	(926	)
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	922,778		(40,928		)	17,302			(474		)	940,080		(41,402		)
	Total	$	1,134,916	$	(41,853	)	$	17,316		$	(475	)	$	1,152,232	$	(42,328	)
		December 31, 2012
		Less than 12 months					12 months or more						Total
		Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Losses			Value			Losses			Value		Losses
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	17	$	—		$	8		$	(1	)	$	25	$	(1	)
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	130,686		(320		)	—			—			130,686		(320		)
	Total	$	130,703	$	(320	)	$	8		$	(1	)	$	130,711	$	(321	)
Scheduled Contractual Maturities Of Investment Securities Available For Sale Table [Text Block]	'
	The table below summarizes the contractual maturities, as of the last scheduled repayment date, of the available-for-sale investment portfolio as of September 30, 2013 (in thousands):
		Amortized		Fair Value
		Cost
	Due in one year or less	$	—	$	—
	Due after one year through five years	20,101		20,107
	Due after five years through ten years	206,538		206,575
	Due after ten years	1,684,489		1,662,861
	Other securities	419		419
	Total investment securities available-for-sale	$	1,911,547	$	1,889,962
Summary of Held-to-Maturity Investment Securities	'
	Held-to-maturity investment securities are summarized as follows as of the dates indicated (in thousands):
		September 30, 2013
		Amortized		Gross			Gross			Fair Value
		Cost		Unrealized			Unrealized
				Gains			Losses
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	530,406	$	3,613		$	(555	)	$	533,464
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	134,311		142			(3,339		)	131,114
	Total investment securities held-to-maturity	$	664,717	$	3,755		$	(3,894	)	$	664,578
		December 31, 2012
		Amortized		Gross			Gross			Fair
		Cost		Unrealized			Unrealized			Value
				Gains			Losses
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	577,486	$	7,065		$	—		$	584,551
	Total investment securities held-to-maturity	$	577,486	$	7,065		$	—		$	584,551
Summary of Contractual Maturities Held-to-Maturity of Investment Portfolio	'
	The table below summarizes the contractual maturities, as of the last scheduled repayment date, of the held-to-maturity investment portfolio at September 30, 2013 (in thousands):
		Amortized		Fair Value
		Cost
	Due in one year or less	$	—	$	—
	Due after one year through five years	—		—
	Due after five years through ten years	19,012		19,235
	Due after ten years	645,705		645,343
	Other securities	—		—
	Total investment securities held-to-maturity	$	664,717	$	664,578

Loans_Tables

Loans - (Tables)	9 Months Ended
	Sep. 30, 2013
Receivables [Abstract]	'
Loan Portfolio Composition Including Carrying Value by Segment of Loans Accounted for under ASC Topic 310-30 and Loans Covered by the FDIC Loss Sharing Agreements	'
	The carrying value of loans are net of discounts on loans excluded from Accounting Standards Codification (“ASC”) Topic 310-30 , and fees and costs of $15.0 million and $20.4 million as of September 30, 2013 and December 31, 2012, respectively (in thousands):
		September 30, 2013
		ASC 310-30			Non 310-30			Total Loans		% of
		Loans			Loans					Total
	Commercial	$	68,250		$	272,114		$	340,364	19.5	%
	Commercial real estate	325,701			288,752			614,453		35.3	%
	Agriculture	37,882			117,464			155,346		8.9	%
	Residential real estate	72,409			523,160			595,569		34.2	%
	Consumer	8,768			28,313			37,081		2.1	%
	Total	$	513,010		$	1,229,803		$	1,742,813	100	%
	Covered	$	309,380		$	56,966		$	366,346	21	%
	Non-covered	203,630			1,172,837			1,376,467		79	%
	Total	$	513,010		$	1,229,803		$	1,742,813	100	%
		December 31, 2012
		ASC 310-30			Non 310-30			Total Loans		% of
		Loans			Loans					Total
	Commercial	$	83,169		$	187,419		$	270,588	14.8	%
	Commercial real estate	566,035			238,964			804,999		43.9	%
	Agriculture	47,733			125,674			173,407		9.5	%
	Residential real estate	106,100			427,277			533,377		29.1	%
	Consumer	18,984			31,347			50,331		2.7	%
	Total	$	822,021		$	1,010,681		$	1,832,702	100	%
	Covered	$	527,948		$	80,274		$	608,222	33.2	%
	Non-covered	294,073			930,407			1,224,480		66.8	%
	Total	$	822,021		$	1,010,681		$	1,832,702	100	%
Loan Delinquency	'
	Loan delinquency for all loans is shown in the following tables at September 30, 2013 and December 31, 2012, respectively (in thousands):
		Total Loans September 30, 2013
		30-59			60-89			Greater		Total  past		Current		Total		Loans > 90		Non-
		days  past			days			than 90		due				loans		days past		accrual
		due			past			days past								due and
					due			due								still
																accruing
	Loans excluded from ASC 310-30
	Commercial	$	410		$	57		$	448	$	915	$	271,199	$	272,114	$	—	$	1,288
	Commercial real estate
	Construction	—			—			—		—		1,652		1,652		—		—
	Acquisition/development	46			—			148		194		7,900		8,094		148		1
	Multifamily	952			—			—		952		7,384		8,336		—		1,129
	Owner-occupied	154			17			—		171		88,846		89,017		—		728
	Non owner-occupied	116			—			4,643		4,759		176,894		181,653		—		4,643
	Total commercial real estate	1,268			17			4,791		6,076		282,676		288,752		148		6,501
	Agriculture	84			—			—		84		117,380		117,464		—		203
	Residential real estate
	Senior lien	1,043			132			1,230		2,405		468,089		470,494		—		5,160
	Junior lien	262			24			132		418		52,248		52,666		—		591
	Total residential real estate	1,305			156			1,362		2,823		520,337		523,160		—		5,751
	Consumer	427			8			24		459		27,854		28,313		21		251
	Total loans excluded from ASC 310-30	3,494			238			6,625		10,357		1,219,446		1,229,803		169		13,994
	Covered loans excluded from ASC 310-30	186			53			425		664		56,302		56,966		—		2,403
	Non-covered loans excluded from ASC 310-30	3,308			185			6,200		9,693		1,163,144		1,172,837		169		11,591
	Total loans excluded from ASC 310-30	3,494			238			6,625		10,357		1,219,446		1,229,803		169		13,994
	Loans accounted for under ASC 310-30
	Commercial	325			564			5,000		5,889		62,361		68,250		4,964		16,857
	Commercial real estate	12,943			8,731			52,773		74,447		251,254		325,701		52,773		—
	Agriculture	3,289			—			2,669		5,958		31,924		37,882		2,669		—
	Residential real estate	1,349			271			1,907		3,527		68,882		72,409		1,907		—
	Consumer	585			6			11		602		8,166		8,768		11		—
	Total loans accounted for under ASC 310-30	18,491			9,572			62,360		90,423		422,587		513,010		62,324		16,857
	Covered loans accounted for under ASC 310-30	11,433			9,199			51,115		71,747		237,633		309,380		51,079		16,857
	Non-covered loans accounted for under ASC 310-30	7,058			373			11,245		18,676		184,954		203,630		11,245		—
	Total loans accounted for under ASC 310-30	18,491			9,572			62,360		90,423		422,587		513,010		62,324		16,857
	Total loans	$	21,985		$	9,810		$	68,985	$	100,780	$	1,642,033	$	1,742,813	$	62,493	$	30,851
	Covered loans	$	11,619		$	9,252		$	51,540	$	72,411	$	293,935	$	366,346	$	51,079	$	19,260
	Non-covered loans	10,366			558			17,445		28,369		1,348,098		1,376,467		11,414		11,591
	Total loans	$	21,985		$	9,810		$	68,985	$	100,780	$	1,642,033	$	1,742,813	$	62,493	$	30,851
		Total Loans December 31, 2012
		30-59			60-89			Greater		Total  past		Current		Total		Loans > 90		Non-
		days  past			days			than 90		due				loans		days past		accrual
		due			past			days past								due and
					due			due								still
																accruing
	Loans excluded from ASC 310-30
	Commercial	$	846		$	148		$	1,122	$	2,116	$	185,303	$	187,419	$	—	$	4,500
	Commercial real estate
	Construction	—			—			—		—		3,915		3,915		—		—
	Acquisition/development	1,948			—			—		1,948		8,485		10,433		—		75
	Multifamily	—			—			34		34		13,387		13,421		—		237
	Owner-occupied	97			106			1,074		1,277		56,490		57,767		—		3,365
	Non owner-occupied	—			122			5,123		5,245		148,183		153,428		—		7,992
	Total commercial real estate	2,045			228			6,231		8,504		230,460		238,964		—		11,669
	Agriculture	33			40			11		84		125,590		125,674		—		251
	Residential real estate
	Senior lien	1,261			119			1,825		3,205		373,243		376,448		22		5,815
	Junior lien	181			—			110		291		50,538		50,829		—		593
	Total residential real estate	1,442			119			1,935		3,496		423,781		427,277		22		6,408
	Consumer	447			48			3		498		30,849		31,347		3		291
	Total loans excluded from ASC 310-30	4,813			583			9,302		14,698		995,983		1,010,681		25		23,119
	Covered loans excluded from ASC 310-30	75			51			2,062		2,188		78,086		80,274		—		6,045
Non-covered loans excluded from ASC 310-30	4,738			532			7,240		12,510		917,897		930,407		25		17,074
Total loans excluded from ASC 310-30	4,813			583			9,302		14,698		995,983		1,010,681		25		23,119
Loans accounted for under ASC 310-30
Commercial	521			563			5,621		6,705		76,464		83,169		5,621		—
Commercial real estate	10,060			3,928			129,656		143,644		422,391		566,035		129,656		—
Agriculture	1,247			16			2,768		4,031		43,702		47,733		2,768		—
Residential real estate	1,247			207			5,463		6,917		99,183		106,100		5,463		—
Consumer	297			327			3,253		3,877		15,107		18,984		3,253		—
Total loans accounted for under ASC 310-30	13,372			5,041			146,761		165,174		656,847		822,021		146,761		—
Covered loans accounted for under ASC 310-30	9,855			3,613			116,883		130,351		397,597		527,948		116,883		—
Non-covered loans accounted for under ASC 310-30	3,517			1,428			29,878		34,823		259,250		294,073		29,878		—
Total loans accounted for under ASC 310-30	13,372			5,041			146,761		165,174		656,847		822,021		146,761		—
Total loans	$	18,185		$	5,624		$	156,063	$	179,872	$	1,652,830	$	1,832,702	$	146,786	$	23,119
Covered loans	$	9,930		$	3,664		$	118,945	$	132,539	$	475,683	$	608,222	$	116,883	$	6,045
Non-covered loans	8,255			1,960			37,118		47,333		1,177,147		1,224,480		29,903		17,074
Total loans	$	18,185		$	5,624		$	156,063	$	179,872	$	1,652,830	$	1,832,702	$	146,786	$	23,119
Credit Exposure for Loans as Determined by Company's Internal Risk Rating System	'
	Credit exposure for all loans as determined by the Company’s internal risk rating system was as follows as of September 30, 2013 and December 31, 2012, respectively (in thousands):
		Total Loans September 30, 2013
		Pass			Special			Substandard		Doubtful		Total
					Mention
	Loans excluded from ASC 310-30
	Commercial	$	225,067		$	8,353		$	38,612	$	82	$	272,114
	Commercial real estate
	Construction	1,652			—			—		—		1,652
	Acquisition/development	1,593			2,646			3,855		—		8,094
	Multifamily	7,207			—			1,097		32		8,336
	Owner-occupied	83,532			1,998			3,487		—		89,017
	Non owner-occupied	140,405			32,143			9,105		—		181,653
	Total commercial real estate	234,389			36,787			17,544		32		288,752
	Agriculture	115,618			1,084			762		—		117,464
	Residential real estate
	Senior lien	461,003			1,547			7,467		477		470,494
	Junior lien	50,113			203			2,350		—		52,666
	Total residential real estate	511,116			1,750			9,817		477		523,160
	Consumer	28,057			—			250		6		28,313
	Total loans excluded from ASC 310-30	1,114,247			47,974			66,985		597		1,229,803
	Covered loans excluded from ASC 310-30	27,826			3,557			25,133		450		56,966
	Non-covered loans excluded from ASC 310-30	1,086,421			44,417			41,852		147		1,172,837
	Total loans excluded from ASC 310-30	1,114,247			47,974			66,985		597		1,229,803
	Loans accounted for under ASC 310-30
	Commercial	25,073			2,865			39,520		792		68,250
	Commercial real estate	134,979			11,757			170,988		7,977		325,701
	Agriculture	26,883			1,724			9,275		—		37,882
	Residential real estate	49,444			1,610			21,355		—		72,409
	Consumer	7,515			504			749		—		8,768
	Total loans accounted for under ASC 310-30	243,894			18,460			241,887		8,769		513,010
	Covered loans accounted for under ASC 310-30	128,530			8,146			166,859		5,845		309,380
	Non-covered loans accounted for under ASC 310-30	115,364			10,314			75,028		2,924		203,630
	Total loans accounted for under ASC 310-30	243,894			18,460			241,887		8,769		513,010
	Total loans	$	1,358,141		$	66,434		$	308,872	$	9,366	$	1,742,813
	Total covered	$	156,356		$	11,703		$	191,992	$	6,295	$	366,346
	Total non-covered	1,201,785			54,731			116,880		3,071		1,376,467
	Total loans	$	1,358,141		$	66,434		$	308,872	$	9,366	$	1,742,813
		Total Loans December 31, 2012
		Pass			Special			Substandard		Doubtful		Total
					Mention
	Loans excluded from ASC 310-30
	Commercial	$	137,537		$	9,776		$	38,696	$	1,410	$	187,419
	Commercial real estate
	Construction	3,915			—			—		—		3,915
	Acquisition/development	6,727			—			3,706		—		10,433
	Multifamily	8,409			3,798			1,201		13		13,421
	Owner-occupied	44,129			4,006			9,632		—		57,767
	Non owner-occupied	104,307			29,394			19,411		316		153,428
	Total commercial real estate	167,487			37,198			33,950		329		238,964
	Agriculture	120,471			1,359			3,844		—		125,674
	Residential real estate
	Senior lien	365,571			2,240			8,106		531		376,448
	Junior lien	48,359			251			2,214		5		50,829
	Total residential real estate	413,930			2,491			10,320		536		427,277
	Consumer	31,050			—			276		21		31,347
	Total loans excluded from ASC 310-30	870,475			50,824			87,086		2,296		1,010,681
	Covered loans excluded from ASC 310-30	32,117			9,974			36,427		1,756		80,274
	Non-covered loans excluded from ASC 310-30	838,358			40,850			50,659		540		930,407
	Total loans excluded from ASC 310-30	870,475			50,824			87,086		2,296		1,010,681
	Loans accounted for under ASC 310-30
	Commercial	29,719			3,628			42,101		7,721		83,169
	Commercial real estate	162,122			60,787			329,869		13,257		566,035
	Agriculture	34,599			1,242			11,892		—		47,733
Residential real estate	57,697			6,614			41,789		—		106,100
Consumer	14,489			723			3,772		—		18,984
Total loans accounted for under ASC 310-30	298,626			72,994			429,423		20,978		822,021
Covered loans accounted for under ASC 310-30	159,430			57,056			292,174		19,288		527,948
Non-covered loans accounted for under ASC 310-30	139,196			15,938			137,249		1,690		294,073
Total loans accounted for under ASC 310-30	298,626			72,994			429,423		20,978		822,021
Total loans	$	1,169,101		$	123,818		$	516,509	$	23,274	$	1,832,702
Total covered	$	191,547		$	67,030		$	328,601	$	21,044	$	608,222
Total non-covered	977,554			56,788			187,908		2,230		1,224,480
Total loans	$	1,169,101		$	123,818		$	516,509	$	23,274	$	1,832,702
Additional Information Regarding Impaired Loans	'
	Additional information regarding impaired loans at September 30, 2013 is set forth in the table below (in thousands):
		Impaired Loans September 30, 2013
		Unpaid			Recorded			Allowance		Average		Interest
		principal			investment			for loan		recorded		income
		balance						losses		investment		recognized
								allocated
	With no related allowance recorded:
	Commercial	$	5,114		$	5,100		$	—	$	6,169	$	276
	Commercial real estate
	Construction	—			—			—		—		—
	Acquisition/development	—			—			—		—		—
	Multifamily	997			952			—		958		—
	Owner-occupied	4,208			3,921			—		4,031		226
	Non-owner occupied	6,262			4,941			—		5,188		8
	Total commercial real estate	11,467			9,814			—		10,177		234
	Agriculture	—			—			—		—		—
	Residential real estate
	Senior lien	762			751			—		752		6
	Junior lien	—			—			—		—		—
	Total residential real estate	762			751			—		752		6
	Consumer	—			—			—		—		—
	Total impaired loans with no related allowance recorded	17,343			15,665			—		17,098		516
	With a related allowance recorded:
	Commercial	2,712			2,570			92		2,744		53
	Commercial real estate
	Construction	—			—			—		—		—
	Acquisition/development	—			1			—		1		—
	Multifamily	184			177			32		187		—
	Owner-occupied	843			634			4		668		11
	Non-owner occupied	644			632			4		636		14
	Total commercial real estate	1,671			1,444			40		1,492		25
	Agriculture	244			223			1		224		—
	Residential real estate
	Senior lien	7,959			7,166			516		7,310		71
	Junior lien	1,924			1,712			17		1,736		40
	Total residential real estate	9,883			8,878			533		9,046		111
	Consumer	319			295			7		313		3
	Total impaired loans with a related allowance recorded	14,829			13,410			673		13,819		192
	Total impaired loans	$	32,172		$	29,075		$	673	$	30,917	$	708
	The table below shows additional information regarding impaired loans at September 30, 2012 (in thousands):
		Impaired Loans September 30, 2012
		Unpaid			Recorded			Allowance		Average		Interest
		principal			investment			for loan		recorded		income
		balance						losses		investment		recognized
								allocated
	With no related allowance recorded:
	Commercial	$	19,544		$	9,521		$	—	$	13,038	$	179
	Commercial real estate
	Construction	—			—			—		—		—
	Acquisition/development	6,904			799			—		830		27
	Multifamily	198			191			—		191		—
	Owner-occupied	5,814			5,450			—		5,455		118
	Non owner-occupied	7,050			6,504			—		5,823		64
	Total commercial real estate	19,966			12,944			—		12,299		209
	Agriculture	185			178			—		181		1
	Residential real estate
	Senior lien	6,616			6,169			—		6,241		94
	Junior lien	996			671			—		675		4
	Total residential real estate	7,612			6,840			—		6,916		98
	Consumer	206			193			—		195		1
	Total impaired loans with no related allowance recorded	47,513			29,676			—		32,629		488
	With a related allowance recorded:
	Commercial	2,066			2,065			1,091		2,185		8
Commercial real estate
Construction	—			—			—		—		—
Acquisition/development	—			—			—		—		—
Multifamily	—			—			—		—		—
Owner-occupied	—			—			—		—		—
Non owner-occupied	5,688			5,123			517		5,284		—
Total commercial real estate	5,688			5,123			517		5,284		—
Agriculture	—			—			—		—		—
Residential real estate
Senior lien	445			421			421		440		—
Junior lien	271			271			3		271		—
Total residential real estate	716			692			424		711		—
Consumer	—			—			—		—		—
Total impaired loans with a related allowance recorded	8,470			7,880			2,032		8,180		8
Total impaired loans	$	55,983		$	37,556		$	2,032	$	40,809	$	496
Additional Information Related to Accruing TDR's	'
	The table below provides additional information related to accruing TDR’s at September 30, 2013 and December 31, 2012 (in thousands):
		Accruing TDR’s
		30-Sep-13
		Recorded			Average			Unpaid		Unfunded
		investment			year-to-			principal		commitments
					date			balance		to fund
					recorded					TDR’s
					investment
	Commercial	$	10,210		$	11,385		$	10,475	$	4,039
	Commercial real estate	930			954			1,009		879
	Agriculture	21			20			20		—
	Residential real estate	3,085			3,131			3,096		20
	Consumer	44			47			44		—
	Total	$	14,290		$	15,537		$	14,644	$	4,938
		Accruing TDR’s
		December 31, 2012
		Recorded			Average			Unpaid		Unfunded
		investment			year-to-			principal		commitments
					date			balance		to fund
					recorded					TDR’s
					investment
	Commercial	$	11,474		$	13,171		$	11,794	$	6,908
	Commercial real estate	3,597			3,708			3,734		—
	Agriculture	—			—			—		—
	Residential real estate	2,458			2,469			2,460		35
	Consumer	191			195			191		—
	Total	$	17,720		$	19,543		$	18,179	$	6,943
Summary of Company's Carrying Value of Non-Accrual TDR's	'
	The following table summarizes the Company’s carrying value of non-accrual TDR’s as of September 30, 2013 and December 31, 2012 (in thousands):
		Non - Accruing TDR’s
		September 30, 2013						December 31, 2012
		Covered			Non-covered			Covered		Non-covered
	Commercial	$	89		$	655		$	1,736	$	1,215
	Commercial real estate	178			4,439			313		6,823
	Agriculture	—			—			—		21
	Residential real estate	1,407			605			1,514		958
	Consumer	—			248			—		291
	Total	$	1,674		$	5,947		$	3,563	$	9,308
Re-Measurement of Loans Accounted for Under ASC Topic 310-30 Resulting in Changes in Carrying Amount of Accretable Yield	'
	The re-measurement of loans accounted for under ASC 310-30 resulted in the following changes in the carrying amount of accretable yield during the nine months ended September 30, 2013 and 2012 (in thousands):
		September 30,			September 30,
		2013			2012
	Accretable yield beginning balance	$	133,585		$	186,494
	Reclassification from non-accretable difference	55,351			46,974
	Reclassification to non-accretable difference	(5,234		)	(8,348		)
	Accretion	(59,616		)	(76,252		)
	Accretable yield ending balance	$	124,086		$	148,868
Composition of Net Book Value for Loans Accounted for under ASC Topic 310-30	'
	Below is the composition of the net book value for loans accounted for under ASC 310-30 at September 30, 2013 and December 31, 2012 (in thousands):
		September 30,			December 31,
		2013			2012
	Contractual cash flows	$	1,075,652		$	1,444,279
	Non-accretable difference	(426,101		)	(488,673		)
	Non-accretable difference on retired pools	(12,455		)	—
	Accretable yield	(124,086		)	(133,585		)
	Loans accounted for under ASC 310-30	$	513,010		$	822,021

Allowance_for_Loan_Losses_Tabl

Allowance for Loan Losses - (Tables)	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Summary of Company's Allowance for Loan Losses ("ALL") and Recorded Investment in Loans	'
	The tables below detail the Company’s allowance for loan losses (“ALL”) and recorded investment in loans as of and for the three and nine months ended September 30, 2013 and 2012 (in thousands):
		Three months ended September 30, 2013
		Commercial			Commercial			Agriculture			Residential			Consumer			Total
					real estate						real estate
	Beginning balance	$	2,286		$	2,419		$	764		$	5,907		$	471		$	11,847
	Non 310-30 beginning balance	2,240			2,113			495			4,333			471			9,652
	Charge-offs	(401		)	—			—			(117		)	(276		)	(794		)
	Recoveries	92			17			—			23			75			207
	Provision	715			(205		)	27			27			186			750
	Non 310-30 ending balance	2,646			1,925			522			4,266			456			9,815
	ASC 310-30 beginning balance	46			306			269			1,574			—			2,195
	Charge-offs	—			—			(221		)	(57		)	—			(278		)
	Recoveries	—			—			—			—			—			—
	Provision	43			(8		)	537			(885		)	—			(313		)
	ASC 310-30 ending balance	89			298			585			632			—			1,604
	Ending balance	$	2,735		$	2,223		$	1,107		$	4,898		$	456		$	11,419
		Nine months ended September 30, 2013
		Commercial			Commercial			Agriculture			Residential			Consumer			Total
					real estate						real estate
	Beginning balance	$	2,798		$	7,396		$	592		$	4,011		$	583		$	15,380
	Non 310-30 beginning balance	2,798			3,056			323			4,011			540			10,728
	Charge-offs	(1,654		)	(943		)	—			(741		)	(717		)	(4,055		)
	Recoveries	187			129			13			64			224			617
	Provision	1,315			(317		)	186			932			409			2,525
	Non 310-30 ending balance	2,646			1,925			522			4,266			456			9,815
	ASC 310-30 beginning balance	—			4,340			269			—			43			4,652
	Charge-offs	(407		)	(2,796		)	(221		)	(623		)	—			(4,047		)
	Recoveries	—			—			—			—			—			—
	Provision	496			(1,246		)	537			1,255			(43		)	999
	ASC 310-30 ending balance	89			298			585			632			—			1,604
	Ending balance	$	2,735		$	2,223		$	1,107		$	4,898		$	456		$	11,419
	Ending allowance balance attributable to:
	Non 310-30 loans individually evaluated for impairment	$	92		$	40		$	1		$	533		$	7		$	673
	Non 310-30 loans collectively evaluated for impairment	2,554			1,885			521			3,733			449			9,142
	ASC 310-30 loans	89			298			585			632			—			1,604
	Total ending allowance balance	$	2,735		$	2,223		$	1,107		$	4,898		$	456		$	11,419
	Loans:
	Non 310-30 individually evaluated for impairment	$	7,670		$	11,258		$	223		$	9,629		$	295		$	29,075
	Non 310-30 collectively evaluated for impairment	264,444			277,494			117,241			513,531			28,018			1,200,728
	ASC 310-30 loans	68,250			325,701			37,882			72,409			8,768			513,010
	Total loans	$	340,364		$	614,453		$	155,346		$	595,569		$	37,081		$	1,742,813
		Three months ended September 30, 2012
		Commercial			Commercial			Agriculture			Residential			Consumer			Total
					real estate						real estate
	Beginning balance	$	3,318		$	7,797		$	660		$	4,872		$	647		$	17,294
	Non 310-30 beginning balance	1,725			3,578			284			3,813			635			10,035
	Charge-offs	(297		)	(35		)	—			(351		)	(566		)	(1,249		)
	Recoveries	279			(195		)	4			(47		)	(41		)	—
	Provision	842			(15		)	(22		)	274			521			1,600
	Non 310-30 ending balance	2,549			3,333			266			3,689			549			10,386
	ASC 310-30 beginning balance	1,593			4,219			376			1,059			12			7,259
	Charge-offs	(1		)	(3,500		)	(144		)	(169		)	—			(3,814		)
	Recoveries	—			2			—			—			—			2
	Provision	(1,592		)	6,012			—			(747		)	(10		)	3,663
	ASC 310-30 ending balance	—			6,733			232			143			2			7,110
	Ending balance	$	2,549		$	10,066		$	498		$	3,832		$	551		$	17,496
		Nine months ended September 30, 2012
		Commercial			Commercial			Agriculture			Residential			Consumer			Total
					real estate						real estate
	Beginning balance	$	2,959		$	3,389		$	282		$	4,121		$	776		$	11,527
	Non 310-30 beginning balance	1,597			3,389			154			3,423			776			9,339
	Charge-offs	(3,056		)	(2,448		)	(8		)	(815		)	(1,161		)	(7,488		)
	Recoveries	279			24			4			49			252			608
Provision	3,729			2,368			116			1,032			682			7,927
Non 310-30 ending balance	2,549			3,333			266			3,689			549			10,386
ASC 310-30 beginning balance	1,362			—			128			698			—			2,188
Charge-offs	(216		)	(11,643		)	(144		)	(729		)	(19		)	(12,751		)
Recoveries	—			275			—			—			—			275
Provision	(1,146		)	18,101			248			174			21			17,398
ASC 310-30 ending balance	—			6,733			232			143			2			7,110
Ending balance	$	2,549		$	10,066		$	498		$	3,832		$	551		$	17,496
Ending allowance balance attributable to:
Non 310-30 loans individually evaluated for impairment	$	1,091		$	517		$	—		$	424		$	—		$	2,032
Non 310-30 loans collectively evaluated for impairment	1,458			2,816			266			3,265			549			8,354
ASC 310-30 loans	—			6,733			232			143			2			7,110
Total ending allowance balance	$	2,549		$	10,066		$	498		$	3,832		$	551		$	17,496
Loans:
Non 310-30 individually evaluated for impairment	$	11,586		$	18,067		$	178		$	7,532		$	193		$	37,556
Non 310-30 collectively evaluated for impairment	156,977			229,786			105,134			398,888			30,149			920,934
ASC 310-30 loans	97,664			664,771			55,944			126,294			26,363			971,036
Total loans	$	266,227		$	912,624		$	161,256		$	532,714		$	56,705		$	1,929,526

FDIC_Indemnification_Asset_Tab

FDIC Indemnification Asset - (Tables)	9 Months Ended
	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'
Summary of Activity Related to FDIC Indemnification Asset	'
	Below is a summary of the activity related to the FDIC indemnification asset during the nine months ended September 30, 2013 and 2012 (in thousands):
		For the nine months ended
		September 30,			September 30,
		2013			2012
	Balance at beginning of period	$	86,923		$	223,402
	Accretion	(11,843		)	(9,165		)
	FDIC portion of charge-offs exceeding fair value marks	7,466			8,100
	Reduction for claims filed	(24,460		)	(109,142		)
	Balance at end of period	$	58,086		$	113,195

Other_Real_Estate_Owned_Tables

Other Real Estate Owned - (Tables)	9 Months Ended
	Sep. 30, 2013
Banking and Thrift [Abstract]	'
Summary of Activity in OREO Balances	'
	A summary of the activity in the OREO balances during the nine months ended September 30, 2013 and 2012 is as follows (in thousands):
		For the nine months ended September 30,
		2013			2012
	Beginning balance	$	94,808		$	120,636
	Transfers from loan portfolio, at fair value	32,408			67,741
	Impairments	(9,142		)	(8,638		)
	Sales	(54,705		)	(57,186		)
	Gain on sale of OREO, net	7,384			6,792
	Ending balance	$	70,753		$	129,345

Deposits_Tables

Deposits - (Tables)	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Summary of Time Deposits Based Upon Contractual Maturity	'
	The following table summarizes the Company’s time deposits, based upon contractual maturity, at September 30, 2013 and December 31, 2012, by remaining maturity (in thousands):
		September 30, 2013				December 31, 2012
		Balance		Weighted		Balance			Weighted
				Average					Average
				Rate					Rate
	Three months or less	$	341,794	0.58	%	$	356,446		0.78	%
	Over 3 months through 6 months	343,463		0.58	%	259,097			0.68	%
	Over 6 months through 12 months	438,725		0.57	%	583,209			0.67	%
	Over 12 months through 24 months	289,159		0.95	%	373,283			0.88	%
	Over 24 months through 36 months	72,360		1.66	%	111,599			1.77	%
	Over 36 months through 48 months	27,653		1.51	%	43,967			1.83	%
	Over 48 months through 60 months	16,275		1.33	%	19,278			1.44	%
	Thereafter	4,961		1.69	%	5,839			2.32	%
	Total time deposits	$	1,534,390	0.72	%	$	1,752,718		0.85	%
Schedule of Interest Expense on Deposits	'
	The Company incurred interest expense on deposits as follows during the periods indicated (in thousands):
		For the three months ended					For the nine months ended
		September 30, 2013		September 30, 2012			September 30, 2013			September 30, 2012
	Interest bearing demand deposits	$	157	$	271		$	536		$	1,007
	Money market accounts	872		1,005			2,534			3,076
	Savings accounts	56		65			170			226
	Time deposits	2,880		5,178			9,407			19,713
	Total	$	3,965	$	6,519		$	12,647		$	24,022

Regulatory_Capital_Tables

Regulatory Capital - (Tables)	9 Months Ended
	Sep. 30, 2013
Banking and Thrift [Abstract]	'
Capital Ratio Requirements under Prompt Corrective Action or Other Regulatory Requirements	'
	At September 30, 2013 and December 31, 2012, as applicable, NBH Bank, N.A. and the consolidated holding company exceeded all capital ratio requirements under prompt corrective action or other regulatory requirements, as is detailed in the table below (in thousands):
		September 30, 2013
		Actual				Required to be				Required to be
						considered well				considered
						capitalized (1)				adequately
										capitalized
		Ratio		Amount		Ratio		Amount		Ratio		Amount
	Tier 1 leverage ratio
	Consolidated	18.5	%	$	948,196	N/A		N/A		4	%	$	205,349
	NBH Bank, N.A.	17.1	%	865,682		10	%	$	507,279	4	%	202,912
	Tier 1 risk-based capital ratio (2)
	Consolidated	48	%	$	948,196	6	%	$	118,619	4	%	$	79,079
	NBH Bank, N.A.	44.3	%	865,682		11	%	214,800		4	%	78,109
	Total risk-based capital ratio (2)
	Consolidated	48.6	%	$	960,415	10	%	$	197,698	8	%	$	158,158
	NBH Bank, N.A.	45	%	877,901		12	%	234,328		8	%	156,218
		December 31, 2012
		Actual				Required to be				Required to be
						considered well				considered
						capitalized (1)				adequately
										capitalized
		Ratio		Amount		Ratio		Amount		Ratio		Amount
	Tier 1 leverage ratio
	Consolidated	18.2	%	$	962,779	N/A		N/A		4	%	$	211,439
	NBH Bank, N.A.	16.4	%	851,365		10	%	$	518,244	4	%	207,298
	Tier 1 risk-based capital ratio (2)
	Consolidated	51.9	%	$	962,779	6	%	$	111,396	4	%	$	74,264
	NBH Bank, N.A.	46.6	%	851,365		11	%	201,147		4	%	73,144
	Total risk-based capital ratio (2)
	Consolidated	52.7	%	$	978,535	10	%	$	185,659	8	%	$	148,527
	NBH Bank, N.A.	47.4	%	867,121		12	%	219,433		8	%	146,289
	-1	These ratio requirements are reflective of the agreements the Company has made with its various regulators in connection with the approval of the de novo charter for NBH Bank, N.A., as described above.
	-2	Due to the conditional guarantee represented by the loss sharing agreements, the FDIC indemnification asset and covered assets are risk-weighted at 20% for purposes of risk-based capital computations.

FDIC_Loss_Sharing_Income_Table

FDIC Loss Sharing Income - (Tables)	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Schedule of Additional Details of Company's FDIC Loss Sharing Income	'
	The table below provides additional details of the Company’s FDIC loss sharing income (expense) during the three and nine months ended September 30, 2013 and 2012 (in thousands):
		For the three months ended						For the nine months ended
		September 30, 2013			September 30, 2012			September 30, 2013			September 30, 2012
	Clawback liability amortization	$	(314	)	$	(355	)	$	(937	)	$	(1,066	)
	Clawback liability remeasurement	(405		)	(820		)	244			247
	Reimbursement to FDIC for gain on sale of and income from covered OREO	(2,514		)	(1,842		)	(4,615		)	(1,408		)
	Reimbursement to FDIC for recoveries	—			(2		)	(22		)	(3		)
	FDIC reimbursement of costs of resolution of covered assets	2,042			4,522			8,608			11,508
	Total	$	(1,191	)	$	1,503		$	3,278		$	9,278

Stockbased_Compensation_and_Em1

Stock-based Compensation and Employee Benefits - (Tables)	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Schedule Of Weighted Average Assumptions Using Black-Scholes option-Pricing Model	'
	The expense associated with the awarded stock options was measured at fair value using a Black-Scholes option-pricing model using the following weighted average assumptions:
		Black-Scholes
	Risk-free interest rate	1.15	%
	Expected volatility	32.07	%
	Expected term (years)	6.7
	Dividend yield	1.09	%
Summary of Option Activity	'
	The following table summarizes option activity for the nine months ended September 30, 2013:
		Options		Weighted		Weighted	Aggregate
				Average		Average	Intrinsic
				Exercise		Remaining	Value
				Price		Contractual
						Term in
						Years
	Outstanding at December 31, 2012	3,471,665		$	19.98	6.94	$	22,800
	Granted during the nine months ended September 30, 2013	174,750		18.62
	Forfeited	(47,570	)	19.35
	Expired	(60,833	)	20
	Exercised	—		—
	Outstanding at September 30, 2013	3,538,012		$	19.92	6.37	$	2,238,176
	Options fully vested and exercisable at September 30, 2013	2,602,082		$	20	6.19	$	—
	Options expected to vest	933,800		$	19.74	6.43	$	2,111,363
Summary of Restricted Stock Activity	'
	The following table summarizes restricted stock activity for the nine months ended September 30, 2013:
		Total Restricted Shares		Weighted Average Grant-Date Fair Value
	Unvested at December 31, 2012	951,668		14.79
	Granted	146,218		18.25
	Forfeited	(10,732	)	18.09
	Unvested at September 30, 2013	1,087,154		15.22

Income_Per_Share_Tables

Income Per Share - (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Schedule of Computation of Basic and Diluted Income Per Share	'
	The following table illustrates the computation of basic and diluted income per share for the three and nine months ended September 30, 2013 and 2012 (in thousands, except share and earnings per share information):
		For the three months ended						For the nine months ended
		September 30,						September 30,
		2013			2012			2013			2012
	Distributed earnings	$	2,622		$	—		$	7,934		$	—
	Undistributed earnings (distributions in excess of earnings)	(1,675		)	(7,891		)	(2,007		)	(3,546		)
	Net income (loss)	$	947		$	(7,891	)	$	5,927		$	(3,546	)
	Less: earnings allocated to participating securities	(5		)	—			(12		)	—
	Earnings allocated to common stockholders	$	942		$	(7,891	)	$	5,915		$	(3,546	)
	Weighted average shares outstanding for basic earnings per common share	51,454,200			52,191,239			51,940,245			52,186,465
	Dilutive effect of equity awards	45,301			—			32,916			—
	Dilutive effect of warrants	2,479			—			—			—
	Weighted average shares outstanding for diluted earnings per common share	51,501,980			52,191,239			51,973,161			52,186,465
	Basic earnings (loss) per share	$	0.02		$	(0.15	)	$	0.11		$	(0.07	)
	Diluted earnings (loss) per share	$	0.02		$	(0.15	)	$	0.11		$	(0.07	)

Tables

- (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Tables of Financial Instruments Measured At Fair Value on Recurring Basis	'
	The tables below present the financial instruments measured at fair value on a recurring basis as of September 30, 2013 and December 31, 2012 on the consolidated statements of financial condition utilizing the hierarchy structure described above (in thousands):
		September 30, 2013
		Level 1		Level 2			Level 3		Total
	Assets:
	Investment securities available-for-sale:
	Asset backed securities	$	—	$	20,098		$	—	$	20,098
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	—		523,183			—		523,183
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	—		1,346,262			—		1,346,262
	Other securities	—		—			419		419
	Total assets at fair value	$	—	$	1,889,543		$	419	$	1,889,962
	Liabilities:
	Warrant liability	$	—	$	—		$	5,599	$	5,599
	Clawback liability	—		—			31,964		31,964
	Total liabilities at fair value	$	—	$	—		$	37,563	$	37,563
		December 31, 2012
		Level 1		Level 2			Level 3		Total
	Assets:
	Investment securities available-for-sale:
	U.S. Treasury securities	$	300	$	—		$	—	$	300
	Asset backed securities	—		90,003			—		90,003
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	—		678,017			—		678,017
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	—		949,289			—		949,289
	Other securities	—		—			419		419
	Total assets at fair value	$	300	$	1,717,309		$	419	$	1,718,028
	Liabilities:
	Warrant liability	$	—	$	—		$	5,461	$	5,461
	Clawback liability	—		—			31,271		31,271
	Total liabilities at fair value	$	—	$	—		$	36,732	$	36,732
Table of Changes in Level 3 Financial Instruments	'
	The table below details the changes in level 3 financial instruments during the nine months ended September 30, 2013 (in thousands):
		Warrant		Clawback
		liability		liability
	Balance at December 31, 2012	$	5,461	$	31,271
	Change in value	138		(244		)
	Accretion	—		937
	Settlement	—		—
	Net change in Level 3	138		693
	Balance at September 30, 2013	$	5,599	$	31,964
Inputs Used to Determine Fair Values of Oreo are Considered Level 3 Inputs in Fair Value Hierarchy	'
	The table below provides information regarding the assets recorded at fair value on a non-recurring basis during the nine months ended September 30, 2013 (in thousands):
		September 30, 2013
		Level 1		Level 2			Level 3		Total		Losses
											From
											Fair
											Value
											Changes
	Other real estate owned	$	—	$	—		$	70,753	$	70,753	$	9,049
	Impaired loans	$	—	$	—		$	29,075	$	29,075	$	1,305
Table of Valuation Techniques and Unobservable Inputs Used in Valuation of Financial Instruments Falling Within Level 3 of Fair Value Hierarchy	'
	The following table provides information about the valuation techniques and unobservable inputs used in the valuation of financial instruments falling within level 3 of the fair value hierarchy as of September 30, 2013. The table below excludes non-recurring fair value measurements of collateral value used for impairment measures for OREO. These valuations utilize third party appraisal or broker price opinions, and are classified as level 3 due to the significant judgment involved (in thousands):
		Fair Value at		Valuation Technique		Unobservable Input	Quantitative
		September 30,					Measures
		2013
	Other securities	$	419	Cash investment in private equity fund		Cash investment
	Impaired loans	29,075		Appraised value		Appraised values
						Discount rate	0-25%
	Clawback liability	31,964		Contractually defined discounted cash flows		Intrinsic loss estimates	$323.3 million -
							$405 million
						Expected credit losses	—
							$98 million-$182.7 million
						Asset purchase premium
						Discount rate	4%
						Discount period	73-85 months
	Warrant liability	5,599		Black-Scholes		Volatility	16%-49%

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments - (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	The fair value of financial instruments at September 30, 2013 and December 31, 2012, including methods and assumptions utilized for determining fair value of financial instruments, are set forth below (in thousands):
			30-Sep-13				31-Dec-12
		Level in Fair	Carrying		Estimated		Carrying		Estimated
		Value	Amount		Fair Value		Amount		Fair Value
		Measurement
		Hierarchy
	ASSETS:
	Cash and cash equivalents	Level 1	$	349,244	$	349,244	$	769,180	$	769,180
	Securities purchased under agreements to resell	Level 2	75,000		75,016		—		—
	U.S. Treasury securities available-for-sale	Level 1	—		—		300		300
	Asset backed securities available-for-sale	Level 2	20,098		20,098		90,003		90,003
	Mortgage-backed securities—residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises available-for-sale	Level 2	523,183		523,183		678,017		678,017
	Mortgage-backed securities—other residential mortgage-backed securities issued or guaranteed by U.S. Government agencies or sponsored enterprises available-for-sale	Level 2	1,346,262		1,346,262		949,289		949,289
	Other securities	Level 3	419		419		419		419
	Mortgage-backed securities—residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	Level 2	530,406		533,464		577,486		584,551
	Mortgage-backed securities—other residential mortgage-backed securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	Level 2	134,311		131,114		—		—
	Capital stock of FHLB	Level 2	6,705		6,705		7,976		7,976
	Capital stock of FRB	Level 2	25,020		25,020		25,020		25,020
	Loans receivable, net	Level 3	1,731,394		1,742,595		1,817,322		1,829,987
	Loans held-for-sale	Level 2	5,265		5,265		5,368		5,368
	Accrued interest receivable	Level 2	11,670		11,670		12,673		12,673
	LIABILITIES:
	Deposit transaction accounts	Level 2	2,417,113		2,417,113		2,448,001		2,448,001
	Time deposits	Level 2	1,534,390		1,538,608		1,752,718		1,759,886
	Securities sold under agreements to repurchase	Level 2	116,471		116,471		53,685		53,685
	Due to FDIC	Level 3	31,964		31,964		31,271		31,271
	Warrant liability	Level 3	5,599		5,599		5,461		5,461
	Accrued interest payable	Level 2	3,225		3,225		4,239		4,239

Investment_Securities_Narrativ

Investment Securities - (Narrative) (Detail) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Investments Schedule [Abstract]	'	'	'
Investment securities total	$2,600,000,000	'	$2,300,000,000
Available-for-sale securities	1,889,962,000	'	1,718,028,000
Mortgage-backed securities as percentage of available-for-sale investment portfolio	98.90%	'	94.70%
Fair value of available-for-sale investment securities pledged as collateral	188,600,000	'	89,200,000
Estimated weighted average life of the available-for-sale mortgage-backed securities portfolio	'4 years 5 months 4 days	'	'3 years 4 months 24 days
Other securities	419,000	'	'
Held-to-maturity securities	664,717,000	'	577,486,000
Available-for-sale securities classification to the held-to-maturity	'	'	754,100,000
Purchase of investment securities held-to-maturity	244,502,000	2,234,000	'
Held-to-maturity investment securities pledged as collateral	$54,400,000	'	$127,900,000
Estimated weighted average expected life of the held-to-maturity mortgage-backed securities portfolio	'4 years 3 months 16 days	'	'3 years 9 months 18 days

Investment_Securities_Summary_

Investment Securities - (Summary of Available-for-Sale Investment Securities) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	$1,911,547	$1,680,748
Gross Unrealized Gains	20,743	37,601
Gross Unrealized Losses	-42,328	-321
Fair Value	1,889,962	1,718,028
U.S. Treasury Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	'	300
Gross Unrealized Gains	'	0
Gross Unrealized Losses	'	0
Fair Value	'	300
Asset Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	20,091	89,881
Gross Unrealized Gains	7	122
Gross Unrealized Losses	0	0
Fair Value	20,098	90,003
Residential Mortgage Pass-Through Securities Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	514,584	658,169
Gross Unrealized Gains	9,525	19,849
Gross Unrealized Losses	-926	-1
Fair Value	523,183	678,017
Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	1,376,453	931,979
Gross Unrealized Gains	11,211	17,630
Gross Unrealized Losses	-41,402	-320
Fair Value	1,346,262	949,289
Other Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	419	419
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$419	$419

Investment_Securities_Summary_1

Investment Securities - (Summary of Unrealized Losses) (Detail) (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]	'	'
Less than 12 months Fair Value	$1,134,916	$130,703
Less than 12 months Unrealized Losses	-41,853	-320
12 months or more, Fair Value	17,316	8
12 months or more, Unrealized Losses	-475	-1
Total, Fair Value	1,152,232	130,711
Total Unrealized losses	-42,328	-321
Residential Mortgage Pass-Through Securities Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less than 12 months Fair Value	212,138	17
Less than 12 months Unrealized Losses	-925	0
12 months or more, Fair Value	14	8
12 months or more, Unrealized Losses	-1	-1
Total, Fair Value	212,152	25
Total Unrealized losses	-926	-1
Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less than 12 months Fair Value	922,778	130,686
Less than 12 months Unrealized Losses	-40,928	-320
12 months or more, Fair Value	17,302	0
12 months or more, Unrealized Losses	-474	0
Total, Fair Value	940,080	130,686
Total Unrealized losses	($41,402)	($320)

Investment_Securities_Summary_2

Investment Securities - (Summary of Contractual Maturities Available-for-Sale Investment Portfolio) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]	'	'
Due in one year or less, Amortized cost	$0	'
Due after one year through five years, Amortized cost	20,101	'
Due after five years through ten years, Amortized cost	206,538	'
Due after ten years, Amortized cost	1,684,489	'
Other securities, Amortized cost	419	'
Total investment securities available-for-sale, Amortized cost	1,911,547	'
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]	'	'
Due in one year or less, Fair Value	0	'
Due after one year through five years, Fair Value	20,107	'
Due after five years through ten years, Fair Value	206,575	'
Due after ten years, Fair Value	1,662,861	'
Other Securities, Fair Value	419	'
Fair Value	$1,889,962	$1,718,028

Investment_Securities_Summary_3

Investment Securities - (Summary of Held-to-maturity Investment Securities) (Detail) (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	$664,717	$577,486
Gross Unrealized Gains	3,755	7,065
Gross Unrealized Losses	-3,894	0
Fair Value	664,578	584,551
Residential Mortgage Pass-Through Securities Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	530,406	577,486
Gross Unrealized Gains	3,613	7,065
Gross Unrealized Losses	-555	0
Fair Value	533,464	584,551
Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	134,311	'
Gross Unrealized Gains	142	'
Gross Unrealized Losses	-3,339	'
Fair Value	$131,114	'

Investment_Securities_Summary_4

Investment Securities - (Summary of Contractual Maturities Held-to-Maturity of Investment Portfolio) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Investments Schedule [Abstract]	'	'
Due in one year or less, Amortized Cost	$0	'
Due after one year through five years, Amortized Cost	0	'
Due after five years through ten years, Amortized Cost	19,012	'
Due after ten years, Amortized Cost	645,705	'
Other Securities, Amortized Cost	0	'
Total investment securities held-to-maturity	664,717	'
Due in one year or less, Fair Value	0	'
Due after one year through five years, Fair Value	0	'
Due after five years through ten years, Fair Value	19,235	'
Due after ten years, Fair Value	645,343	'
Other Securities, Fair Value	0	'
Fair Value	$664,578	$584,551

Loans_Narrative_Section_Detail

Loans - Narrative Section (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
Debt Instrument [Line Items]	'	'	'
Covered Loans Percentage	21.00%	33.20%	'
Fees and cost related to loans	$15,000,000	$20,400,000	'
Carrying amount of loan investments	1,742,813,000	1,832,702,000	1,929,526,000
Loans excluded from ASC 310-30	1,731,394,000	1,817,322,000	'
Non Accrual [Member]	'	'	'
Debt Instrument [Line Items]	'	'	'
Financing Receivable, Recorded Investment, Nonaccrual Status	13,994,000	23,119,000	'
ASC 310-30 [Member]	'	'	'
Debt Instrument [Line Items]	'	'	'
Carrying amount of loan investments	513,010,000	822,021,000	'
Covered [Member] | ASC 310-30 [Member] | Non Accrual [Member] | Commercial And Industrial Loan [Member]	'	'	'
Debt Instrument [Line Items]	'	'	'
Financing Receivable, Recorded Investment, Nonaccrual Status	$16,857,000	'	'

Loans_Impaired_Loans_Narrative

Loans - Impaired Loans Narrative (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'	'
Impaired loans	$9,500	'	'
Recorded investment of impaired loans	29,075	'	37,556
Impaired loans which were covered by FDIC loss sharing agreement	366,346	608,222	7,500
Collective related allowance for loan losses for impaired loans	673	'	2,032
Discounted Cash Flows [Member]	'	'	'
Debt Instrument [Line Items]	'	'	'
Impaired loans	14,800	'	'
Fair Value Of Collateral Pledged [Member]	'	'	'
Debt Instrument [Line Items]	'	'	'
Impaired loans	4,700	'	'
General Reserve [Member]	'	'	'
Debt Instrument [Line Items]	'	'	'
Impaired loans	250	'	'
Covered [Member]	'	'	'
Debt Instrument [Line Items]	'	'	'
Impaired loans which were covered by FDIC loss sharing agreement	$8,400	'	'

Loans_Loan_Portfolio_Compositi

Loans - (Loan Portfolio Composition Including Carrying Value by Segment of Loans Accounted for under ASC Topic 310-30 and Loans Covered by the FDIC Loss Sharing Agreements) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
In Thousands, unless otherwise specified
Loans [Line Items]	'	'	'
Total Loans	$1,742,813	$1,832,702	$1,929,526
Covered Loans Percentage	21.00%	33.20%	'
% of Total	100.00%	100.00%	'
Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	366,346	608,222	'
Non-Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,376,467	1,224,480	'
% of Total	79.00%	66.80%	'
Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	340,364	270,588	266,227
% of Total	19.50%	14.80%	'
Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	614,453	804,999	912,624
% of Total	35.30%	43.90%	'
Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	155,346	173,407	161,256
% of Total	8.90%	9.50%	'
Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	595,569	533,377	532,714
% of Total	34.20%	29.10%	'
Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	37,081	50,331	56,705
% of Total	2.10%	2.70%	'
ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	513,010	822,021	'
ASC 310-30 [Member] | Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	309,380	527,948	'
ASC 310-30 [Member] | Non-Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	203,630	294,073	'
ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	68,250	83,169	'
ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	325,701	566,035	'
ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	37,882	47,733	'
ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	72,409	106,100	'
ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	8,768	18,984	'
Non ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,229,803	1,010,681	'
Non ASC 310-30 [Member] | Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	56,966	80,274	'
Non ASC 310-30 [Member] | Non-Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,172,837	930,407	'
Non ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	272,114	187,419	'
Non ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	288,752	238,964	'
Non ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	117,464	125,674	'
Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	523,160	427,277	'
Non ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	$28,313	$31,347	'

Loans_Loan_Delinquency_Detail

Loans - (Loan Delinquency) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
In Thousands, unless otherwise specified
Loans [Line Items]	'	'	'
Total loans	$1,742,813	$1,832,702	$1,929,526
Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	340,364	270,588	266,227
Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	614,453	804,999	912,624
Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	155,346	173,407	161,256
Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	595,569	533,377	532,714
Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	37,081	50,331	56,705
Non ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	1,229,803	1,010,681	'
Non ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	272,114	187,419	'
Non ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	288,752	238,964	'
Non ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	117,464	125,674	'
Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	523,160	427,277	'
Non ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	28,313	31,347	'
ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	513,010	822,021	'
ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	68,250	83,169	'
ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	325,701	566,035	'
ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	37,882	47,733	'
ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	72,409	106,100	'
ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	8,768	18,984	'
Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	366,346	608,222	'
Covered [Member] | Non ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	56,966	80,274	'
Covered [Member] | ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	309,380	527,948	'
Non-Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	1,376,467	1,224,480	'
Non-Covered [Member] | Non ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	1,172,837	930,407	'
Non-Covered [Member] | ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total loans	203,630	294,073	'
Total Loans [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	21,985	18,185	'
60-89 days past due	9,810	5,624	'
Greater than 90 days past due	68,985	156,063	'
Total past due	100,780	179,872	'
Current	1,642,033	1,652,830	'
Total loans	1,742,813	1,832,702	'
Loans 90 days past due and still accruing	62,493	146,786	'
Non- accrual	30,851	23,119	'
Total Loans [Member] | Non ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	3,494	4,813	'
60-89 days past due	238	583	'
Greater than 90 days past due	6,625	9,302	'
Total past due	10,357	14,698	'
Current	1,219,446	995,983	'
Total loans	1,229,803	1,010,681	'
Loans 90 days past due and still accruing	169	25	'
Non- accrual	13,994	23,119	'
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial Construction [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	0	0	'
60-89 days past due	0	0	'
Greater than 90 days past due	0	0	'
Total past due	0	0	'
Current	1,652	3,915	'
Total loans	1,652	3,915	'
Loans 90 days past due and still accruing	0	0	'
Non- accrual	0	0	'
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial Acquisition/Development [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	46	1,948	'
60-89 days past due	0	0	'
Greater than 90 days past due	148	0	'
Total past due	194	1,948	'
Current	7,900	8,485	'
Total loans	8,094	10,433	'
Loans 90 days past due and still accruing	148	0	'
Non- accrual	1	75	'
Total Loans [Member] | Non ASC 310-30 [Member] | Multifamily [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	952	0	'
60-89 days past due	0	0	'
Greater than 90 days past due	0	34	'
Total past due	952	34	'
Current	7,384	13,387	'
Total loans	8,336	13,421	'
Loans 90 days past due and still accruing	0	0	'
Non- accrual	1,129	237	'
Total Loans [Member] | Non ASC 310-30 [Member] | Owner-Occupied [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	154	97	'
60-89 days past due	17	106	'
Greater than 90 days past due	0	1,074	'
Total past due	171	1,277	'
Current	88,846	56,490	'
Total loans	89,017	57,767	'
Loans 90 days past due and still accruing	0	0	'
Non- accrual	728	3,365	'
Total Loans [Member] | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	116	0	'
60-89 days past due	0	122	'
Greater than 90 days past due	4,643	5,123	'
Total past due	4,759	5,245	'
Current	176,894	148,183	'
Total loans	181,653	153,428	'
Loans 90 days past due and still accruing	0	0	'
Non- accrual	4,643	7,992	'
Total Loans [Member] | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	1,268	2,045	'
60-89 days past due	17	228	'
Greater than 90 days past due	4,791	6,231	'
Total past due	6,076	8,504	'
Current	282,676	230,460	'
Total loans	288,752	238,964	'
Loans 90 days past due and still accruing	148	0	'
Non- accrual	6,501	11,669	'
Total Loans [Member] | Non ASC 310-30 [Member] | Sr lien [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	1,043	1,261	'
60-89 days past due	132	119	'
Greater than 90 days past due	1,230	1,825	'
Total past due	2,405	3,205	'
Current	468,089	373,243	'
Total loans	470,494	376,448	'
Loans 90 days past due and still accruing	0	22	'
Non- accrual	5,160	5,815	'
Total Loans [Member] | Non ASC 310-30 [Member] | Jr Liens [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	262	181	'
60-89 days past due	24	0	'
Greater than 90 days past due	132	110	'
Total past due	418	291	'
Current	52,248	50,538	'
Total loans	52,666	50,829	'
Loans 90 days past due and still accruing	0	0	'
Non- accrual	591	593	'
Total Loans [Member] | Non ASC 310-30 [Member] | Covered loans excluded from ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	186	75	'
60-89 days past due	53	51	'
Greater than 90 days past due	425	2,062	'
Total past due	664	2,188	'
Current	56,302	78,086	'
Total loans	56,966	80,274	'
Loans 90 days past due and still accruing	0	0	'
Non- accrual	2,403	6,045	'
Total Loans [Member] | Non ASC 310-30 [Member] | Non-covered loans excluded from ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	3,308	4,738	'
60-89 days past due	185	532	'
Greater than 90 days past due	6,200	7,240	'
Total past due	9,693	12,510	'
Current	1,163,144	917,897	'
Total loans	1,172,837	930,407	'
Loans 90 days past due and still accruing	169	25	'
Non- accrual	11,591	17,074	'
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	410	846	'
60-89 days past due	57	148	'
Greater than 90 days past due	448	1,122	'
Total past due	915	2,116	'
Current	271,199	185,303	'
Total loans	272,114	187,419	'
Loans 90 days past due and still accruing	0	0	'
Non- accrual	1,288	4,500	'
Total Loans [Member] | Non ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	84	33	'
60-89 days past due	0	40	'
Greater than 90 days past due	0	11	'
Total past due	84	84	'
Current	117,380	125,590	'
Total loans	117,464	125,674	'
Loans 90 days past due and still accruing	0	0	'
Non- accrual	203	251	'
Total Loans [Member] | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	1,305	1,442	'
60-89 days past due	156	119	'
Greater than 90 days past due	1,362	1,935	'
Total past due	2,823	3,496	'
Current	520,337	423,781	'
Total loans	523,160	427,277	'
Loans 90 days past due and still accruing	0	22	'
Non- accrual	5,751	6,408	'
Total Loans [Member] | Non ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	427	447	'
60-89 days past due	8	48	'
Greater than 90 days past due	24	3	'
Total past due	459	498	'
Current	27,854	30,849	'
Total loans	28,313	31,347	'
Loans 90 days past due and still accruing	21	3	'
Non- accrual	251	291	'
Total Loans [Member] | ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	18,491	13,372	'
60-89 days past due	9,572	5,041	'
Greater than 90 days past due	62,360	146,761	'
Total past due	90,423	165,174	'
Current	422,587	656,847	'
Total loans	513,010	822,021	'
Loans 90 days past due and still accruing	62,324	146,761	'
Non- accrual	16,857	0	'
Total Loans [Member] | ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	325	521	'
60-89 days past due	564	563	'
Greater than 90 days past due	5,000	5,621	'
Total past due	5,889	6,705	'
Current	62,361	76,464	'
Total loans	68,250	83,169	'
Loans 90 days past due and still accruing	4,964	5,621	'
Non- accrual	16,857	0	'
Total Loans [Member] | ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	12,943	10,060	'
60-89 days past due	8,731	3,928	'
Greater than 90 days past due	52,773	129,656	'
Total past due	74,447	143,644	'
Current	251,254	422,391	'
Total loans	325,701	566,035	'
Loans 90 days past due and still accruing	52,773	129,656	'
Non- accrual	0	0	'
Total Loans [Member] | ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	3,289	1,247	'
60-89 days past due	0	16	'
Greater than 90 days past due	2,669	2,768	'
Total past due	5,958	4,031	'
Current	31,924	43,702	'
Total loans	37,882	47,733	'
Loans 90 days past due and still accruing	2,669	2,768	'
Non- accrual	0	0	'
Total Loans [Member] | ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	1,349	1,247	'
60-89 days past due	271	207	'
Greater than 90 days past due	1,907	5,463	'
Total past due	3,527	6,917	'
Current	68,882	99,183	'
Total loans	72,409	106,100	'
Loans 90 days past due and still accruing	1,907	5,463	'
Non- accrual	0	0	'
Total Loans [Member] | ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	585	297	'
60-89 days past due	6	327	'
Greater than 90 days past due	11	3,253	'
Total past due	602	3,877	'
Current	8,166	15,107	'
Total loans	8,768	18,984	'
Loans 90 days past due and still accruing	11	3,253	'
Non- accrual	0	0	'
Total Loans [Member] | ASC 310-30 [Member] | Covered loans accounted for under ASC Topic 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	11,433	9,855	'
60-89 days past due	9,199	3,613	'
Greater than 90 days past due	51,115	116,883	'
Total past due	71,747	130,351	'
Current	237,633	397,597	'
Total loans	309,380	527,948	'
Loans 90 days past due and still accruing	51,079	116,883	'
Non- accrual	16,857	0	'
Total Loans [Member] | ASC 310-30 [Member] | Non-covered loans accounted for under ASC Topic 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	7,058	3,517	'
60-89 days past due	373	1,428	'
Greater than 90 days past due	11,245	29,878	'
Total past due	18,676	34,823	'
Current	184,954	259,250	'
Total loans	203,630	294,073	'
Loans 90 days past due and still accruing	11,245	29,878	'
Non- accrual	0	0	'
Total Loans [Member] | Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	11,619	9,930	'
60-89 days past due	9,252	3,664	'
Greater than 90 days past due	51,540	118,945	'
Total past due	72,411	132,539	'
Current	293,935	475,683	'
Total loans	366,346	608,222	'
Loans 90 days past due and still accruing	51,079	116,883	'
Non- accrual	19,260	6,045	'
Total Loans [Member] | Non-Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	10,366	8,255	'
60-89 days past due	558	1,960	'
Greater than 90 days past due	17,445	37,118	'
Total past due	28,369	47,333	'
Current	1,348,098	1,177,147	'
Total loans	1,376,467	1,224,480	'
Loans 90 days past due and still accruing	11,414	29,903	'
Non- accrual	11,591	17,074	'
Total Loans [Member] | Covered And Non-covered [Member]	'	'	'
Loans [Line Items]	'	'	'
30-59 days past due	21,985	18,185	'
60-89 days past due	9,810	5,624	'
Greater than 90 days past due	68,985	156,063	'
Total past due	100,780	179,872	'
Current	1,642,033	1,652,830	'
Total loans	1,742,813	1,832,702	'
Loans 90 days past due and still accruing	62,493	146,786	'
Non- accrual	$30,851	$23,119	'

Loans_Credit_Exposure_for_Loan

Loans - (Credit Exposure for Loans as Determined by Company's Internal Risk Rating System) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
In Thousands, unless otherwise specified
Loans [Line Items]	'	'	'
Total Loans	$1,742,813	$1,832,702	$1,929,526
Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	155,346	173,407	161,256
Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	595,569	533,377	532,714
Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	37,081	50,331	56,705
Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	340,364	270,588	266,227
Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	614,453	804,999	912,624
Non ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,229,803	1,010,681	'
Non ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	117,464	125,674	'
Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	523,160	427,277	'
Non ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	28,313	31,347	'
Non ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	272,114	187,419	'
Non ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	288,752	238,964	'
ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	513,010	822,021	'
ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	37,882	47,733	'
ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	72,409	106,100	'
ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	8,768	18,984	'
ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	68,250	83,169	'
ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	325,701	566,035	'
Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	366,346	608,222	'
Covered [Member] | Non ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	56,966	80,274	'
Covered [Member] | ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	309,380	527,948	'
Non-Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,376,467	1,224,480	'
Non-Covered [Member] | Non ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,172,837	930,407	'
Non-Covered [Member] | ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	203,630	294,073	'
Total Loans [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,742,813	1,832,702	'
Total Loans [Member] | Non ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,229,803	1,010,681	'
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial Construction [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,652	3,915	'
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial Acquisition/Development [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	8,094	10,433	'
Total Loans [Member] | Non ASC 310-30 [Member] | Multifamily [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	8,336	13,421	'
Total Loans [Member] | Non ASC 310-30 [Member] | Owner-Occupied [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	89,017	57,767	'
Total Loans [Member] | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	181,653	153,428	'
Total Loans [Member] | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	288,752	238,964	'
Total Loans [Member] | Non ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	117,464	125,674	'
Total Loans [Member] | Non ASC 310-30 [Member] | Sr lien [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	470,494	376,448	'
Total Loans [Member] | Non ASC 310-30 [Member] | Jr Liens [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	52,666	50,829	'
Total Loans [Member] | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	523,160	427,277	'
Total Loans [Member] | Non ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	28,313	31,347	'
Total Loans [Member] | Non ASC 310-30 [Member] | Covered loans excluded from ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	56,966	80,274	'
Total Loans [Member] | Non ASC 310-30 [Member] | Non-covered loans excluded from ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,172,837	930,407	'
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	272,114	187,419	'
Total Loans [Member] | ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	513,010	822,021	'
Total Loans [Member] | ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	37,882	47,733	'
Total Loans [Member] | ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	72,409	106,100	'
Total Loans [Member] | ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	8,768	18,984	'
Total Loans [Member] | ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	68,250	83,169	'
Total Loans [Member] | ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	325,701	566,035	'
Total Loans [Member] | ASC 310-30 [Member] | Covered loans accounted for under ASC Topic 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	309,380	527,948	'
Total Loans [Member] | ASC 310-30 [Member] | Non-covered loans accounted for under ASC Topic 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	203,630	294,073	'
Total Loans [Member] | Pass [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,358,141	1,169,101	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,114,247	870,475	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Commercial Construction [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,652	3,915	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Commercial Acquisition/Development [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,593	6,727	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Multifamily [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	7,207	8,409	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Owner-Occupied [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	83,532	44,129	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	140,405	104,307	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	234,389	167,487	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	115,618	120,471	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Sr lien [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	461,003	365,571	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Jr Liens [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	50,113	48,359	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	511,116	413,930	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	28,057	31,050	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Covered loans excluded from ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	27,826	32,117	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Non-covered loans excluded from ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,086,421	838,358	'
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	225,067	137,537	'
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	243,894	298,626	'
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	26,883	34,599	'
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	49,444	57,697	'
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	7,515	14,489	'
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	25,073	29,719	'
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	134,979	162,122	'
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member] | Covered loans accounted for under ASC Topic 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	128,530	159,430	'
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member] | Non-covered loans accounted for under ASC Topic 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	115,364	139,196	'
Total Loans [Member] | Special Mention [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	66,434	123,818	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	47,974	50,824	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Commercial Construction [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	0	0	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Commercial Acquisition/Development [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	2,646	0	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Multifamily [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	0	3,798	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Owner-Occupied [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,998	4,006	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	32,143	29,394	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	36,787	37,198	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,084	1,359	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Sr lien [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,547	2,240	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Jr Liens [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	203	251	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,750	2,491	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	0	0	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Covered loans excluded from ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	3,557	9,974	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Non-covered loans excluded from ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	44,417	40,850	'
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	8,353	9,776	'
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	18,460	72,994	'
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,724	1,242	'
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,610	6,614	'
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	504	723	'
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	2,865	3,628	'
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	11,757	60,787	'
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member] | Covered loans accounted for under ASC Topic 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	8,146	57,056	'
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member] | Non-covered loans accounted for under ASC Topic 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	10,314	15,938	'
Total Loans [Member] | Substandard [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	308,872	516,509	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	66,985	87,086	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Commercial Construction [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	0	0	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Commercial Acquisition/Development [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	3,855	3,706	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Multifamily [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,097	1,201	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Owner-Occupied [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	3,487	9,632	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	9,105	19,411	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	17,544	33,950	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	762	3,844	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Sr lien [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	7,467	8,106	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Jr Liens [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	2,350	2,214	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	9,817	10,320	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	250	276	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Covered loans excluded from ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	25,133	36,427	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Non-covered loans excluded from ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	41,852	50,659	'
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	38,612	38,696	'
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	241,887	429,423	'
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	9,275	11,892	'
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	21,355	41,789	'
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	749	3,772	'
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	39,520	42,101	'
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	170,988	329,869	'
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member] | Covered loans accounted for under ASC Topic 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	166,859	292,174	'
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member] | Non-covered loans accounted for under ASC Topic 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	75,028	137,249	'
Total Loans [Member] | Doubtful [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	9,366	23,274	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	597	2,296	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Commercial Construction [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	0	0	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Commercial Acquisition/Development [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	0	0	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Multifamily [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	32	13	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Owner-Occupied [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	0	0	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	0	316	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	32	329	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	0	0	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Sr lien [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	477	531	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Jr Liens [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	0	5	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	477	536	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	6	21	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Covered loans excluded from ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	450	1,756	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Non-covered loans excluded from ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	147	540	'
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	82	1,410	'
Total Loans [Member] | Doubtful [Member] | ASC 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	8,769	20,978	'
Total Loans [Member] | Doubtful [Member] | ASC 310-30 [Member] | Agriculture [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	0	0	'
Total Loans [Member] | Doubtful [Member] | ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	0	0	'
Total Loans [Member] | Doubtful [Member] | ASC 310-30 [Member] | Consumer [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	0	0	'
Total Loans [Member] | Doubtful [Member] | ASC 310-30 [Member] | Commercial Loan [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	792	7,721	'
Total Loans [Member] | Doubtful [Member] | ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	7,977	13,257	'
Total Loans [Member] | Doubtful [Member] | ASC 310-30 [Member] | Covered loans accounted for under ASC Topic 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	5,845	19,288	'
Total Loans [Member] | Doubtful [Member] | ASC 310-30 [Member] | Non-covered loans accounted for under ASC Topic 310-30 [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	2,924	1,690	'
Total Loans [Member] | Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	366,346	608,222	'
Total Loans [Member] | Covered [Member] | Pass [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	156,356	191,547	'
Total Loans [Member] | Covered [Member] | Special Mention [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	11,703	67,030	'
Total Loans [Member] | Covered [Member] | Substandard [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	191,992	328,601	'
Total Loans [Member] | Covered [Member] | Doubtful [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	6,295	21,044	'
Total Loans [Member] | Non-Covered [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,376,467	1,224,480	'
Total Loans [Member] | Non-Covered [Member] | Pass [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,201,785	977,554	'
Total Loans [Member] | Non-Covered [Member] | Special Mention [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	54,731	56,788	'
Total Loans [Member] | Non-Covered [Member] | Substandard [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	116,880	187,908	'
Total Loans [Member] | Non-Covered [Member] | Doubtful [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	3,071	2,230	'
Total Loans [Member] | Covered And Non-covered [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,742,813	1,832,702	'
Total Loans [Member] | Covered And Non-covered [Member] | Pass [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	1,358,141	1,169,101	'
Total Loans [Member] | Covered And Non-covered [Member] | Special Mention [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	66,434	123,818	'
Total Loans [Member] | Covered And Non-covered [Member] | Substandard [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	308,872	516,509	'
Total Loans [Member] | Covered And Non-covered [Member] | Doubtful [Member]	'	'	'
Loans [Line Items]	'	'	'
Total Loans	$9,366	$23,274	'

Loans_Additional_Information_R

Loans - (Additional Information Regarding Impaired Loans) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Loans [Line Items]	'	'
Unpaid principal balance, Total	$32,172	$55,983
Recorded Investment In Acquired Impaired Loans	29,075	37,556
Loans and Leases Receivable, Allowance	673	2,032
Average recorded investment, Total	30,917	40,809
Interest income recognized, Total	708	496
Commercial Loan [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance with no related allowance recorded	5,114	19,544
Recorded investment with no related allowance recorded	5,100	9,521
Allowance for loan losses allocated with no related allowance recorded	0	0
Average recorded investment of impaired loans with no related allowance recorded	6,169	13,038
Interest income recognized of impaired loans with no related allowance recorded	276	179
Unpaid principal balance of impaired loans with an allowance recorded	2,712	2,066
Recorded investment of impaired loans with an allowance recorded	2,570	2,065
Allowance for loan losses allocated with an allowance recorded	92	1,091
Average recorded investment of impaired loans with an allowance recorded	2,744	2,185
Interest income recognized of impaired loans with an allowance recorded	53	8
Commercial Construction [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance with no related allowance recorded	0	0
Recorded investment with no related allowance recorded	0	0
Allowance for loan losses allocated with no related allowance recorded	0	0
Average recorded investment of impaired loans with no related allowance recorded	0	0
Interest income recognized of impaired loans with no related allowance recorded	0	0
Unpaid principal balance of impaired loans with an allowance recorded	0	0
Recorded investment of impaired loans with an allowance recorded	0	0
Allowance for loan losses allocated with an allowance recorded	0	0
Average recorded investment of impaired loans with an allowance recorded	0	0
Interest income recognized of impaired loans with an allowance recorded	0	0
Commercial Acquisition/Development [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance with no related allowance recorded	0	6,904
Recorded investment with no related allowance recorded	0	799
Allowance for loan losses allocated with no related allowance recorded	0	0
Average recorded investment of impaired loans with no related allowance recorded	0	830
Interest income recognized of impaired loans with no related allowance recorded	0	27
Unpaid principal balance of impaired loans with an allowance recorded	0	0
Recorded investment of impaired loans with an allowance recorded	1	0
Allowance for loan losses allocated with an allowance recorded	0	0
Average recorded investment of impaired loans with an allowance recorded	1	0
Interest income recognized of impaired loans with an allowance recorded	0	0
Multifamily [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance with no related allowance recorded	997	198
Recorded investment with no related allowance recorded	952	191
Allowance for loan losses allocated with no related allowance recorded	0	0
Average recorded investment of impaired loans with no related allowance recorded	958	191
Interest income recognized of impaired loans with no related allowance recorded	0	0
Unpaid principal balance of impaired loans with an allowance recorded	184	0
Recorded investment of impaired loans with an allowance recorded	177	0
Allowance for loan losses allocated with an allowance recorded	32	0
Average recorded investment of impaired loans with an allowance recorded	187	0
Interest income recognized of impaired loans with an allowance recorded	0	0
Owner-Occupied [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance with no related allowance recorded	4,208	5,814
Recorded investment with no related allowance recorded	3,921	5,450
Allowance for loan losses allocated with no related allowance recorded	0	0
Average recorded investment of impaired loans with no related allowance recorded	4,031	5,455
Interest income recognized of impaired loans with no related allowance recorded	226	118
Unpaid principal balance of impaired loans with an allowance recorded	843	0
Recorded investment of impaired loans with an allowance recorded	634	0
Allowance for loan losses allocated with an allowance recorded	4	0
Average recorded investment of impaired loans with an allowance recorded	668	0
Interest income recognized of impaired loans with an allowance recorded	11	0
Non Owner-Occupied [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance with no related allowance recorded	6,262	7,050
Recorded investment with no related allowance recorded	4,941	6,504
Allowance for loan losses allocated with no related allowance recorded	0	0
Average recorded investment of impaired loans with no related allowance recorded	5,188	5,823
Interest income recognized of impaired loans with no related allowance recorded	8	64
Unpaid principal balance of impaired loans with an allowance recorded	644	5,688
Recorded investment of impaired loans with an allowance recorded	632	5,123
Allowance for loan losses allocated with an allowance recorded	4	517
Average recorded investment of impaired loans with an allowance recorded	636	5,284
Interest income recognized of impaired loans with an allowance recorded	14	0
Total Commercial Real Estate [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance with no related allowance recorded	11,467	19,966
Recorded investment with no related allowance recorded	9,814	12,944
Allowance for loan losses allocated with no related allowance recorded	0	0
Average recorded investment of impaired loans with no related allowance recorded	10,177	12,299
Interest income recognized of impaired loans with no related allowance recorded	234	209
Unpaid principal balance of impaired loans with an allowance recorded	1,671	5,688
Recorded investment of impaired loans with an allowance recorded	1,444	5,123
Allowance for loan losses allocated with an allowance recorded	40	517
Average recorded investment of impaired loans with an allowance recorded	1,492	5,284
Interest income recognized of impaired loans with an allowance recorded	25	0
Agriculture [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance with no related allowance recorded	0	185
Recorded investment with no related allowance recorded	0	178
Allowance for loan losses allocated with no related allowance recorded	0	0
Average recorded investment of impaired loans with no related allowance recorded	0	181
Interest income recognized of impaired loans with no related allowance recorded	0	1
Unpaid principal balance of impaired loans with an allowance recorded	244	0
Recorded investment of impaired loans with an allowance recorded	223	0
Allowance for loan losses allocated with an allowance recorded	1	0
Average recorded investment of impaired loans with an allowance recorded	224	0
Interest income recognized of impaired loans with an allowance recorded	0	0
Sr Lien 1-4 Family Closed End [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance with no related allowance recorded	762	6,616
Recorded investment with no related allowance recorded	751	6,169
Allowance for loan losses allocated with no related allowance recorded	0	0
Average recorded investment of impaired loans with no related allowance recorded	752	6,241
Interest income recognized of impaired loans with no related allowance recorded	6	94
Unpaid principal balance of impaired loans with an allowance recorded	7,959	445
Recorded investment of impaired loans with an allowance recorded	7,166	421
Allowance for loan losses allocated with an allowance recorded	516	421
Average recorded investment of impaired loans with an allowance recorded	7,310	440
Interest income recognized of impaired loans with an allowance recorded	71	0
Jr Lien 1-4 Family Closed End [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance with no related allowance recorded	0	996
Recorded investment with no related allowance recorded	0	671
Allowance for loan losses allocated with no related allowance recorded	0	0
Average recorded investment of impaired loans with no related allowance recorded	0	675
Interest income recognized of impaired loans with no related allowance recorded	0	4
Unpaid principal balance of impaired loans with an allowance recorded	1,924	271
Recorded investment of impaired loans with an allowance recorded	1,712	271
Allowance for loan losses allocated with an allowance recorded	17	3
Average recorded investment of impaired loans with an allowance recorded	1,736	271
Interest income recognized of impaired loans with an allowance recorded	40	0
Residential Real Estate Segment [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance with no related allowance recorded	762	7,612
Recorded investment with no related allowance recorded	751	6,840
Allowance for loan losses allocated with no related allowance recorded	0	0
Average recorded investment of impaired loans with no related allowance recorded	752	6,916
Interest income recognized of impaired loans with no related allowance recorded	6	98
Unpaid principal balance of impaired loans with an allowance recorded	9,883	716
Recorded investment of impaired loans with an allowance recorded	8,878	692
Allowance for loan losses allocated with an allowance recorded	533	424
Average recorded investment of impaired loans with an allowance recorded	9,046	711
Interest income recognized of impaired loans with an allowance recorded	111	0
Consumer [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance with no related allowance recorded	0	206
Recorded investment with no related allowance recorded	0	193
Allowance for loan losses allocated with no related allowance recorded	0	0
Average recorded investment of impaired loans with no related allowance recorded	0	195
Interest income recognized of impaired loans with no related allowance recorded	0	1
Unpaid principal balance of impaired loans with an allowance recorded	319	0
Recorded investment of impaired loans with an allowance recorded	295	0
Allowance for loan losses allocated with an allowance recorded	7	0
Average recorded investment of impaired loans with an allowance recorded	313	0
Interest income recognized of impaired loans with an allowance recorded	3	0
Impaired Loans With No Related Allowance Recorded [Member] [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance with no related allowance recorded	17,343	47,513
Recorded investment with no related allowance recorded	15,665	29,676
Allowance for loan losses allocated with no related allowance recorded	0	0
Average recorded investment of impaired loans with no related allowance recorded	17,098	32,629
Interest income recognized of impaired loans with no related allowance recorded	516	488
Impaired Loans with Related Allowance Recorded [Member]	'	'
Loans [Line Items]	'	'
Unpaid principal balance of impaired loans with an allowance recorded	14,829	8,470
Recorded investment of impaired loans with an allowance recorded	13,410	7,880
Allowance for loan losses allocated with an allowance recorded	673	2,032
Average recorded investment of impaired loans with an allowance recorded	13,819	8,180
Interest income recognized of impaired loans with an allowance recorded	$192	$8

Loans_Troubled_Debt_Restructur

Loans - Troubled Debt Restructuring and Loans Accounted for Under ASC Topic 310-30 Narratives (Details) (USD $)	9 Months Ended					9 Months Ended			9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013
	SecurityLoan				Non Accrual [Member]	Troubled Debt Restructurings [Member]	Troubled Debt Restructurings [Member]	Troubled Debt Restructurings [Member]	FDIC Covered [Member]	FDIC Covered [Member]	Commercial And Industrial Loan, A Commercial Real Estate Loan, And A Single Family Residential Loan [Member]
						SecurityLoan	Non Accrual [Member]	Non Accrual [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Accretable yield related for loan pool in non-accrual status	$124,086,000	$133,585,000	$148,868,000	$186,494,000	$1,400,000	'	'	'	'	'	'
TDRbs modified within the past year that defaulted on their restructured terms	2	'	'	'	'	'	'	'	'	'	'
Accruing troubled debt restructurings	'	'	'	'	'	'	'	'	6,000,000	5,000,000	'
Carrying amount of loan investments	1,742,813,000	1,832,702,000	1,929,526,000	'	'	'	7,600,000	12,900,000	'	'	'
Number of restructured loans	'	'	'	'	'	43	'	'	'	'	'
Recorded investment	'	'	'	'	'	5,500,000	'	'	'	'	'
Commercial and Industry loan	'	'	'	'	'	'	'	'	'	'	$328,000

Loans_Additional_Information_R1

Loans - (Additional Information Related to Accruing TDR's) (Detail) (Accruing TDR [Member], USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Loans [Line Items]	'	'
Recorded investment	$14,290	$17,720
Average year-to- date recorded investment	15,537	19,543
Unpaid principal balance	14,644	18,179
Unfunded commitments to fund TDRbs	4,938	6,943
Commercial [Member]	'	'
Loans [Line Items]	'	'
Recorded investment	10,210	11,474
Average year-to- date recorded investment	11,385	13,171
Unpaid principal balance	10,475	11,794
Unfunded commitments to fund TDRbs	4,039	6,908
Commercial Real Estate [Member]	'	'
Loans [Line Items]	'	'
Recorded investment	930	3,597
Average year-to- date recorded investment	954	3,708
Unpaid principal balance	1,009	3,734
Unfunded commitments to fund TDRbs	879	0
Agriculture [Member]	'	'
Loans [Line Items]	'	'
Recorded investment	21	0
Average year-to- date recorded investment	20	0
Unpaid principal balance	20	0
Unfunded commitments to fund TDRbs	0	0
Residential Real Estate Segment [Member]	'	'
Loans [Line Items]	'	'
Recorded investment	3,085	2,458
Average year-to- date recorded investment	3,131	2,469
Unpaid principal balance	3,096	2,460
Unfunded commitments to fund TDRbs	20	35
Consumer [Member]	'	'
Loans [Line Items]	'	'
Recorded investment	44	191
Average year-to- date recorded investment	47	195
Unpaid principal balance	44	191
Unfunded commitments to fund TDRbs	$0	$0

Loans_Summary_of_Companys_Carr

Loans - (Summary of Company's Carrying Value of Non-Accrual TDR's) (Detail) (Non-Accruing TDR [Member], USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Covered [Member]	'	'
Loans [Line Items]	'	'
Carrying Value of Non - Accruing TDRbs	$1,674	$3,563
Covered [Member] | Commercial [Member]	'	'
Loans [Line Items]	'	'
Carrying Value of Non - Accruing TDRbs	89	1,736
Covered [Member] | Commercial Real Estate [Member]	'	'
Loans [Line Items]	'	'
Carrying Value of Non - Accruing TDRbs	178	313
Covered [Member] | Agriculture [Member]	'	'
Loans [Line Items]	'	'
Carrying Value of Non - Accruing TDRbs	0	0
Covered [Member] | Residential Real Estate Segment [Member]	'	'
Loans [Line Items]	'	'
Carrying Value of Non - Accruing TDRbs	1,407	1,514
Covered [Member] | Consumer [Member]	'	'
Loans [Line Items]	'	'
Carrying Value of Non - Accruing TDRbs	0	0
Non-Covered [Member]	'	'
Loans [Line Items]	'	'
Carrying Value of Non - Accruing TDRbs	5,947	9,308
Non-Covered [Member] | Commercial [Member]	'	'
Loans [Line Items]	'	'
Carrying Value of Non - Accruing TDRbs	655	1,215
Non-Covered [Member] | Commercial Real Estate [Member]	'	'
Loans [Line Items]	'	'
Carrying Value of Non - Accruing TDRbs	4,439	6,823
Non-Covered [Member] | Agriculture [Member]	'	'
Loans [Line Items]	'	'
Carrying Value of Non - Accruing TDRbs	0	21
Non-Covered [Member] | Residential Real Estate Segment [Member]	'	'
Loans [Line Items]	'	'
Carrying Value of Non - Accruing TDRbs	605	958
Non-Covered [Member] | Consumer [Member]	'	'
Loans [Line Items]	'	'
Carrying Value of Non - Accruing TDRbs	$248	$291

Loans_ReMeasurement_of_Loans_A

Loans - (Re-Measurement of Loans Accounted for Under ASC Topic 310-30 Resulting in Changes in Carrying Amount of Accretable Yield) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]	'	'
Accretable yield beginning balance	$133,585	$186,494
Reclassification from non-accretable difference	55,351	46,974
Reclassification to non-accretable difference	-5,234	-8,348
Accretion	-59,616	-76,252
Accretable yield ending balance	$124,086	$148,868

Loans_Composition_of_Net_Book_

Loans - (Composition of Net Book Value for Loans Accounted for under ASC Topic 310-30) (Detail) (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Receivables [Abstract]	'	'
Contractual cash flows	$1,075,652	$1,444,279
Non-accretable difference	-426,101	-488,673
Non-accretable difference on retired pools	-12,455	0
Accretable yield	-124,086	-133,585
Loans accounted for under ASC 310-30	$513,010	$822,021

Allowance_for_Loan_Losses_Summ

Allowance for Loan Losses - (Summary of Company's Allowance for Loan Losses ("All") and Recorded Investment in Loans) (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

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 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

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

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Sep. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Mar. 31, 2012

Dec. 31, 2011

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Mar. 31, 2012

Dec. 31, 2011

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Sep. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Mar. 31, 2012

Dec. 31, 2011

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Mar. 31, 2012

Dec. 31, 2011

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Sep. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Mar. 31, 2012

Dec. 31, 2011

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Commercial Real Estate [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Agriculture [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Residential Real Estate Segment [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Consumer [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

Non ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

ASC 310-30 [Member]

Allowance for Loan and Lease Losses [Roll Forward]

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Beginning balance

'

$15,380

$11,527

$11,847

'

$17,294

'

'

$10,728

$9,339

$9,652

'

$10,035

'

'

$4,652

$2,188

$2,195

'

$7,259

$2,735

$2,286

$2,798

$2,549

$3,318

$2,959

'

'

$2,798

$1,597

$2,240

'

$1,725

'

'

$0

$1,362

$46

'

$1,593

'

$7,396

$2,419

'

$10,066

$7,797

$3,389

'

'

$3,056

$3,389

$2,113

'

$3,578

'

'

$4,340

$0

$306

'

$4,219

'

$764

$592

$498

$660

$282

'

'

$323

$154

$495

'

$284

'

'

$269

$128

$269

'

$376

'

$4,011

$5,907

'

$3,832

$4,872

$4,121

'

'

$4,011

$3,423

$4,333

'

$3,813

'

'

$0

$698

$1,574

'

$1,059

$456

$471

$583

$551

$647

$776

'

'

$540

$776

$471

'

$635

'

'

$43

$0

$0

'

$12

Charge-offs

'

'

'

'

'

'

-794

-1,249

-4,055

-7,488

'

'

'

-278

-3,814

-4,047

-12,751

'

'

'

'

'

'

'

'

'

-401

-297

-1,654

-3,056

'

'

'

0

-1

-407

-216

'

'

'

'

'

'

'

'

'

'

0

-35

-943

-2,448

'

'

'

0

-3,500

-2,796

-11,643

'

'

'

'

'

'

'

'

'

0

0

0

-8

'

'

'

-221

-144

-221

-144

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'

'

'

'

'

'

'

'

'

-117

-351

-741

-815

'

'

'

-57

-169

-623

-729

'

'

'

'

'

'

'

'

'

-276

-566

-717

-1,161

'

'

'

0

0

0

-19

'

'

'

Recoveries

'

'

'

'

'

'

207

0

617

608

'

'

'

0

2

0

275

'

'

'

'

'

'

'

'

'

92

279

187

279

'

'

'

0

0

0

0

'

'

'

'

'

'

'

'

'

'

17

-195

129

24

'

'

'

0

2

0

275

'

'

'

'

'

'

'

'

'

0

4

13

4

'

'

'

0

0

0

0

'

'

'

'

'

'

'

'

'

'

23

-47

64

49

'

'

'

0

0

0

0

'

'

'

'

'

'

'

'

'

75

-41

224

252

'

'

'

0

0

0

0

'

'

'

Provision for loan losses

-313

-3,524

-25,325

'

'

'

750

1,600

2,525

7,927

'

'

'

'

3,663

999

17,398

'

'

'

'

'

'

'

'

'

715

842

1,315

3,729

'

'

'

43

1,592

496

-1,146

'

'

'

-8

-1,246

'

'

'

'

'

-205

-15

-317

2,368

'

'

'

'

-6,012

'

18,101

'

'

'

537

'

'

'

'

'

27

-22

186

116

'

'

'

'

0

537

248

'

'

'

-885

1,255

'

'

'

'

'

27

274

932

1,032

'

'

'

'

-747

'

174

'

'

'

'

'

'

'

'

'

186

521

409

682

'

'

'

0

-10

-43

21

'

'

'

Ending balance

11,419

11,419

17,496

11,847

'

17,294

9,815

10,386

9,815

10,386

9,652

'

10,035

1,604

7,110

1,604

7,110

2,195

'

7,259

2,735

2,286

2,798

2,549

3,318

2,959

2,646

2,549

2,646

2,549

2,240

'

1,725

89

0

89

0

46

'

1,593

2,223

2,223

2,419

'

10,066

7,797

3,389

1,925

3,333

1,925

3,333

2,113

'

3,578

298

6,733

298

6,733

306

'

4,219

1,107

764

592

498

660

282

522

266

522

266

495

'

284

585

232

585

232

269

'

376

4,898

4,898

5,907

'

3,832

4,872

4,121

4,266

3,689

4,266

3,689

4,333

'

3,813

632

143

632

143

1,574

'

1,059

456

471

583

551

647

776

456

549

456

549

471

'

635

0

2

0

2

0

'

12

Ending allowance balance individually evaluated for impairment

'

'

'

'

'

'

673

2,032

673

2,032

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

92

1,091

92

1,091

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

40

517

40

517

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

0

1

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

533

424

533

424

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7

0

7

0

'

'

'

'

'

'

'

'

'

'

Ending allowance balance collectively evaluated for impairment

'

'

'

'

'

'

9,142

8,354

9,142

8,354

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,554

1,458

2,554

1,458

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,885

2,816

1,885

2,816

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

521

266

521

266

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,733

3,265

3,733

3,265

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

449

549

449

549

'

'

'

'

'

'

'

'

'

'

Ending allowance balance

'

'

'

'

'

'

'

'

'

'

'

'

'

1,604

7,110

1,604

7,110

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

89

0

89

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

298

6,733

298

6,733

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

585

232

585

232

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

632

143

632

143

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0

2

0

2

'

'

'

Total ending allowance balance

11,419

11,419

17,496

11,847

'

17,294

9,815

10,386

9,815

10,386

9,652

'

10,035

1,604

7,110

1,604

7,110

2,195

'

7,259

2,735

2,286

2,798

2,549

3,318

2,959

2,646

2,549

2,646

2,549

2,240

'

1,725

89

0

89

0

46

'

1,593

2,223

2,223

2,419

'

10,066

7,797

3,389

1,925

3,333

1,925

3,333

2,113

'

3,578

298

6,733

298

6,733

306

'

4,219

1,107

764

592

498

660

282

522

266

522

266

495

'

284

585

232

585

232

269

'

376

4,898

4,898

5,907

'

3,832

4,872

4,121

4,266

3,689

4,266

3,689

4,333

'

3,813

632

143

632

143

1,574

'

1,059

456

471

583

551

647

776

456

549

456

549

471

'

635

0

2

0

2

0

'

12

Loans individually evaluated for impairment

'

'

'

'

'

'

29,075

37,556

29,075

37,556

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7,670

11,586

7,670

11,586

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

11,258

18,067

11,258

18,067

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

223

178

223

178

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9,629

7,532

9,629

7,532

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

295

193

295

193

'

'

'

'

'

'

'

'

'

'

Loans collectively evaluated for impairment

'

'

'

'

'

'

1,200,728

920,934

1,200,728

920,934

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

264,444

156,977

264,444

156,977

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

277,494

229,786

277,494

229,786

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

117,241

105,134

117,241

105,134

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

513,531

398,888

513,531

398,888

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

28,018

30,149

28,018

30,149

'

'

'

'

'

'

'

'

'

'

Loans

'

'

'

'

'

'

'

'

'

'

'

'

'

513,010

971,036

513,010

971,036

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

68,250

97,664

68,250

97,664

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

325,701

664,771

325,701

664,771

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

37,882

55,944

37,882

55,944

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

72,409

126,294

72,409

126,294

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8,768

26,363

8,768

26,363

'

'

'

Total Loans

$1,742,813

$1,742,813

$1,929,526

'

$1,832,702

'

$1,229,803

'

$1,229,803

'

'

$1,010,681

'

$513,010

'

$513,010

'

'

$822,021

'

$340,364

'

$270,588

$266,227

'

'

$272,114

'

$272,114

'

'

$187,419

'

$68,250

'

$68,250

'

'

$83,169

'

$614,453

$614,453

'

$804,999

$912,624

'

'

$288,752

'

$288,752

'

'

$238,964

'

$325,701

'

$325,701

'

'

$566,035

'

$155,346

'

$173,407

$161,256

'

'

$117,464

'

$117,464

'

'

$125,674

'

$37,882

'

$37,882

'

'

$47,733

'

$595,569

$595,569

'

$533,377

$532,714

'

'

$523,160

'

$523,160

'

'

$427,277

'

$72,409

'

$72,409

'

'

$106,100

'

$37,081

'

$50,331

$56,705

'

'

$28,313

'

$28,313

'

'

$31,347

'

$8,768

'

$8,768

'

'

$18,984

'

Allowance_for_Loan_Losses_Narr

Allowance for Loan Losses - (Narrative) (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Allowance For Loan And Lease Losses [Line Items]	'	'	'	'
Company charged off, net of recoveries	($600,000)	'	($3,400,000)	'
Provision for loan losses	313,000	'	3,524,000	25,325,000
Commercial Real Estate [Member]	'	'	'	'
Allowance For Loan And Lease Losses [Line Items]	'	'	'	'
Company charged off, net of recoveries	'	'	'	2,400,000
Provision for loan losses	8,000	'	1,246,000	'
Residential Real Estate Segment [Member]	'	'	'	'
Allowance For Loan And Lease Losses [Line Items]	'	'	'	'
Provision for loan losses	885,000	'	-1,255,000	'
Non Accrual [Member]	'	'	'	'
Allowance For Loan And Lease Losses [Line Items]	'	'	'	'
Allowance for Doubtful Accounts Receivable, Charge-offs	400,000	'	1,700,000	'
ASC 310-30 [Member]	'	'	'	'
Allowance For Loan And Lease Losses [Line Items]	'	'	'	'
Provision for loan losses	'	-3,663,000	-999,000	-17,398,000
ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'	'
Allowance For Loan And Lease Losses [Line Items]	'	'	'	'
Provision for loan losses	'	6,012,000	'	-18,101,000
ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'	'
Allowance For Loan And Lease Losses [Line Items]	'	'	'	'
Provision for loan losses	'	747,000	'	-174,000
Non ASC 310-30 [Member]	'	'	'	'
Allowance For Loan And Lease Losses [Line Items]	'	'	'	'
Company charged off, net of recoveries	'	'	'	-6,900,000
Provision for loan losses	-750,000	-1,600,000	-2,525,000	-7,927,000
Non ASC 310-30 [Member] | Commercial and Industrial Pool [Member]	'	'	'	'
Allowance For Loan And Lease Losses [Line Items]	'	'	'	'
Company charged off, net of recoveries	'	'	'	2,400,000
Non ASC 310-30 [Member] | Commercial Real Estate [Member]	'	'	'	'
Allowance For Loan And Lease Losses [Line Items]	'	'	'	'
Provision for loan losses	205,000	15,000	317,000	-2,368,000
Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]	'	'	'	'
Allowance For Loan And Lease Losses [Line Items]	'	'	'	'
Provision for loan losses	-27,000	-274,000	-932,000	-1,032,000
Outside Core Market [Member] | Commercial Real Estate [Member]	'	'	'	'
Allowance For Loan And Lease Losses [Line Items]	'	'	'	'
Company charged off, net of recoveries	'	'	'	$2,100,000

FDIC_Indemnification_Asset_Sum

FDIC Indemnification Asset - (Summary of Activity Related to FDIC Indemnification Asset) (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
FDIC Indemnification Asset [Roll Forward]	'	'	'	'
Balance at beginning of period	'	'	$86,923	$223,402
Accretion	-4,208	-2,832	-11,843	-9,165
FDIC portion of charge-offs exceeding fair value marks	'	'	7,466	8,100
Decrease In Carrying Value Of Fdic Indemnification Asset	'	'	-24,460	-109,142
Balance at end of period	$58,086	$113,195	$58,086	$113,195

FDIC_Indemnification_Asset_Nar

FDIC Indemnification Asset - (Narrative) (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Banking and Thrift [Abstract]	'	'	'	'
Negative accretion on the FDIC indemnification asset	($4,208,000)	($2,832,000)	($11,843,000)	($9,165,000)
Decrease in carrying value of FDIC indemnification asset	'	'	-24,460,000	-109,142,000
Payment received from FDIC related to losses incurred	'	'	$77,000,000	'

Other_Real_Estate_Owned_Summar

Other Real Estate Owned - (Summary of Activity in OREO Balances) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Other Real Estate [Roll Forward]	'	'
Balance	$94,808	$120,636
Transfers from loan portfolio, at fair value	32,408	67,741
Impairments	-9,142	-8,638
Sales	-54,705	-57,186
Gain on sale of OREO, net	7,384	6,792
Balance	$70,753	$129,345

Other_Real_Estate_Owned_Narrat

Other Real Estate Owned - (Narrative) (Detail) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Banking and Thrift [Abstract]	'	'	'	'
OREO balance	$70,753,000	$129,345,000	$94,808,000	$120,636,000
Interests of several outside participating banks	3,800,000	'	5,300,000	'
Minority interests in OREO which are held by outside banks	10,600,000	'	10,600,000	'
Percentage covered by the loss sharing agreements with the FDIC	62.30%	49.90%	'	'
Amount covered by the loss sharing agreements with the FDIC	44,100,000	64,500,000	'	'
Sale of OREO	54,705,000	57,186,000	'	'
Realized net gains on sales of OREO	$7,384,000	$6,792,000	'	'

Deposits_Narrative_Detail

Deposits - (Narrative) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Banking and Thrift [Abstract]	'	'
Total Deposits	$3,951,503,000	$4,200,719,000
Time deposits	1,534,390,000	1,752,718,000
Time deposits that were subject to penalty-free withdrawals	$82,600,000	$164,300,000

Deposits_Summary_of_Time_Depos

Deposits - (Summary of Time Deposits Based Upon Contractual Maturity) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Banking and Thrift [Abstract]	'	'
Time Deposits - Three months or less	$341,794	$356,446
Time Deposits - Over 3 months through 6 months	343,463	259,097
Time Deposits - Over 6 months through 12 months	438,725	583,209
Time Deposits - Over 12 months through 24 months	289,159	373,283
Time Deposits - Over 24 months through 36 months	72,360	111,599
Time Deposits - Over 36 months through 48 months	27,653	43,967
Time Deposits - Over 48 months through 60 months	16,275	19,278
Time Deposits - Thereafter	4,961	5,839
Total time deposits	$1,534,390	$1,752,718
Three months or less, Weighted Average Rate	0.58%	0.78%
Over 3 months through 6 months, Weighted Average Rate	0.58%	0.68%
Over 6 months through 12 months, Weighted Average Rate	0.57%	0.67%
Over 12 months through 24 months, Weighted Average Rate	0.95%	0.88%
Over 24 months through 36 months, Weighted Average Rate	1.66%	1.77%
Over 36 months through 48 months, Weighted Average Rate	1.51%	1.83%
Over 48 months through 60 months, Weighted Average Rate	1.33%	1.44%
Thereafter, Weighted Average Rate	1.69%	2.32%
Total time deposits, Weighted Average Rate	0.72%	0.85%

Deposits_Schedule_of_Interest_

Deposits - (Schedule of Interest Expense on Deposits) (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
Banking and Thrift [Abstract]	'	'	'	'
Interest bearing demand deposits	$157	$271	$536	$1,007
Money market accounts	872	1,005	2,534	3,076
Savings accounts	56	65	170	226
Time deposits	2,880	5,178	9,407	19,713
Total	$3,965	$6,519	$12,647	$24,022

Regulatory_Capital_Capital_Rat

Regulatory Capital - (Capital Ratio Requirements under Prompt Corrective Action or Other Regulatory Requirements) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Minimum [Member]	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Risk-based capital computations	20.00%	'
Consolidated [Member]	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Leverage Ratio	18.50%	18.20%
Risk-based capital Ratio	48.00%	51.90%
Total risk-based capital Ratio	48.60%	52.70%
Leverage Amount	$948,196	$962,779
Risk-based capital amount	948,196	962,779
Total risk-based capital Amount	960,415	978,535
Required to be considered well capitalized Ratio, risk-based capital ratio	6.00%	6.00%
Required to be considered well capitalized Ratio, Total risk-based capital ratio	10.00%	10.00%
Required to be considered well capitalized risk-based capital Amount	118,619	111,396
Required to be considered well capitalized Total risk-based capital Amount	197,698	185,659
Required to be considered adequately capitalized Ratio, leverage ratio	4.00%	-4.00%
Required to be considered adequately capitalized Ratio, risk-based capital ratio	4.00%	-4.00%
Required to be considered adequately capitalized Ratio, Total risk-based capital ratio	8.00%	-8.00%
Required to be considered adequately capitalized leverage Amount	205,349	211,439
Required to be considered adequately capitalized risk-based capital Amount	79,079	74,264
Required to be considered adequately capitalized Total risk-based capital Amount	158,158	148,527
NBH Bank, N.A. [Member]	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Leverage Ratio	17.10%	16.40%
Risk-based capital Ratio	44.30%	46.60%
Total risk-based capital Ratio	45.00%	47.40%
Leverage Amount	865,682	851,365
Risk-based capital amount	865,682	851,365
Total risk-based capital Amount	877,901	867,121
Required to be considered well capitalized Ratio, leverage ratio	10.00%	10.00%
Required to be considered well capitalized Ratio, risk-based capital ratio	11.00%	11.00%
Required to be considered well capitalized Ratio, Total risk-based capital ratio	12.00%	12.00%
Required to be considered well capitalized leverage Amount	507,279	518,244
Required to be considered well capitalized risk-based capital Amount	214,800	201,147
Required to be considered well capitalized Total risk-based capital Amount	234,328	219,433
Required to be considered adequately capitalized Ratio, leverage ratio	4.00%	-4.00%
Required to be considered adequately capitalized Ratio, risk-based capital ratio	4.00%	-4.00%
Required to be considered adequately capitalized Ratio, Total risk-based capital ratio	8.00%	-8.00%
Required to be considered adequately capitalized leverage Amount	202,912	207,298
Required to be considered adequately capitalized risk-based capital Amount	78,109	73,144
Required to be considered adequately capitalized Total risk-based capital Amount	$156,218	$146,289

FDIC_Loss_Sharing_Income_Sched

FDIC Loss Sharing Income - (Schedule of Additional Details of Company's FDIC Loss Sharing Income) (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
Banking and Thrift [Abstract]	'	'	'	'
Clawback liability amortization	($314)	($355)	($937)	($1,066)
Clawback liability remeasurement	-405	-820	244	247
Reimbursement to FDIC for gain on sale of and income from covered OREO	-2,514	-1,842	-4,615	-1,408
Reimbursement to FDIC for recoveries	0	-2	-22	-3
FDIC reimbursement of costs of resolution of covered assets	2,042	4,522	8,608	11,508
Total	($1,191)	$1,503	$3,278	$9,278

Stockbased_Compensation_and_Em2

Stock-based Compensation and Employee Benefits - (Narrative) (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
			Company
Share Based Compensation [Line Items]	'	'	'	'
Option awards, contractual terms	'	'	'10 years	'
Number of comparable companies for expected volatility	'	'	9	'
Dividend policy at the time of grant	'	'	$0.05	'
Options granted weighted average grant date fair values	'	'	$5.54	'
Stock option expense	$0.50	$3.90	$1.80	$5.90
restricted shares	'	'	'1 year 1 month 6 days	'
Expense related to restricted stock	0.8	2.7	2.2	5
Unrecognized compensation cost related to non-vested restricted shares granted	'	'	2.3	'
Minimum [Member]	'	'	'	'
Share Based Compensation [Line Items]	'	'	'	'
Option awards vest on a graded basis	'	'	'1 year	'
Maximum [Member]	'	'	'	'
Share Based Compensation [Line Items]	'	'	'	'
Option awards vest on a graded basis	'	'	'4 years	'
Non-Vested Stock Options [Member]	'	'	'	'
Share Based Compensation [Line Items]	'	'	'	'
Total unrecognized compensation expense relate to stock options	'	'	$1.80	'
restricted shares	'	'	'10 months 24 days	'

Stockbased_Compensation_and_Em3

Stock-based Compensation and Employee Benefits - (Schedule Of Weighted Average Assumptions Using Black-Scholes option-Pricing Model) (Detail) (Black-Scholes [Member])	9 Months Ended
	Sep. 30, 2013
Black-Scholes [Member]	'
Share Based Compensation [Line Items]	'
Risk-free interest rate	1.15%
Expected volatility	32.07%
Expected term (years)	'6 years 8 months 12 days
Dividend yield	1.09%

Stockbased_Compensation_and_Em4

Stock-based Compensation and Employee Benefits - (Summary of Option Activity) (Detail) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'	'
Outstanding Options, beginning	3,471,665	'
Granted, Options	174,750	'
Forfeited, Options	-47,570	'
Expired, Options	-60,833	'
Exercised, Options	0	'
Outstanding Options, ending	3,538,012	3,471,665
Outstanding, Weighted Average Exercise Price, beginning	$19.98	'
Granted, Weighted Average Exercise Price	$18.62	'
Forfeited, Weighted Average Exercise Price	$19.35	'
Expired, Weighted Average Exercise Price	$20	'
Exercised, Weighted Average Exercise Price	$0	'
Outstanding, Weighted Average Exercised Price, ending	$19.92	$19.98
Outstanding, Weighted Average Remaining Contractual Term in Years, beginning	'6 years 4 months 13 days	'6 years 11 months 9 days
Outstanding, Weighted Average Remaining Contractual Term in Years, ending	'6 years 4 months 13 days	'6 years 11 months 9 days
Outstanding, Aggregate Intrinsic Value, beginning	$22,800	'
Outstanding, Aggregate Intrinsic Value, ending	2,238,176	22,800
Options fully vested and exercisable at June 30, 2013, Options	2,602,082	'
Options expected to vest, Options	933,800	'
Options fully vested and exercisable at June 30, 2013, Weighted Average Exercise Price	$20	'
Options expected to vest, Weighted Average Exercise Price	$19.74	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	'6 years 2 months 8 days	'
Options expected to vest, Weighted Average Remaining Contractual Term in Years	'6 years 5 months 5 days	'
Aggregate intrinsic Value of Options fully vested and exercisable at June 30, 2013	0	'
Options expected to vest, Aggregate Intrinsic Value	$2,111,363	'

Stockbased_Compensation_and_Em5

Stock-based Compensation and Employee Benefits - (Summary of Restricted Stock Activity) (Details) (Common Class A [Member], Restricted Stock [Member], USD $)	9 Months Ended
	Sep. 30, 2013
Common Class A [Member] | Restricted Stock [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]	'
Unvested Restricted Shares, Beginning (in shares)	951,668
Unvested Restricted Shares, Granted (in shares)	146,218
Unvested Restricted Shares, Forfeited (in shares)	-10,732
Unvested Restricted Shares, Ending (in shares)	1,087,154
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'
Weighted Average Grant-Date Fair Value, Beginning (in dollars per share)	$14.79
Weighted Average Grant-Date Fair Value, Granted (in dollars per share)	$18.25
Weighted Average Grant-Date Fair Value, Forfeited (in dollars per share)	$18.09
Weighted Average Grant-Date Fair Value, Ending (in dollars per share)	$15.22

Common_Stock_Narrative_Detail

Common Stock - (Narrative) (Detail)	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Schedule Of Common Stock [Line Items]	'	'
Shares outstanding	51,213,044	52,327,672
Restricted issued but not yet vested, shares	1,087,154	951,668
Common Class A [Member]	'	'
Schedule Of Common Stock [Line Items]	'	'
Shares outstanding	45,245,425	46,368,483
Common Class B [Member]	'	'
Schedule Of Common Stock [Line Items]	'	'
Shares outstanding	5,967,619	5,959,189

Income_Per_Share_Narrative_Det

Income Per Share - (Narrative) (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Earnings Per Share [Abstract]	'	'	'
Shares outstanding	51,213,044	52,191,239	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	3,538,012	'	3,471,665
Outstanding stock options to purchase common stock	'	3,443,332	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$19.92	'	$19.98
Outstanding stock options to purchase common stock, per share	'	$20	'
Outstanding warrants	830,750	'	'
Exercise price of warrants	$20	'	'
Restricted shares outstanding	1,087,154	1,169,792	'

Income_Per_Share_Schedule_of_C

Income Per Share - (Schedule of Computation of Basic and Diluted Income Per Share) (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Distributed earnings	$2,622	$0	$7,934	$0
Undistributed earnings (distributions in excess of earnings)	-1,675	-7,891	-2,007	-3,546
Net income	947	-7,891	5,927	-3,546
Less: earnings allocated to participating securities	-5	0	-12	0
Income available to common stockholders (numerator)	$942	($7,891)	$5,915	($3,546)
Weighted average common shares outstanding (denominator)	51,454,200	52,191,239	51,940,245	52,186,465
Weighted average shares outstanding for diluted earnings per common share	51,501,980	52,191,239	51,973,161	52,186,465
Income per sharebbasic (in dollars per share)	$0.02	($0.15)	$0.11	($0.07)
Income per sharebdiluted (in dollars per share)	$0.02	($0.15)	$0.11	($0.07)
Equity Option [Member]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Dilutive Convertible Securities	45,301	0	32,916	0
Warrant [Member]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Dilutive Convertible Securities	2,479	0	0	0

Derivatives_Details

Derivatives - (Details) (Interest Rate Swap [Member], Not Designated as Hedging Instrument [Member], USD $)	Sep. 30, 2013
	Swap
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member]	'
Derivative [Line Items]	'
Number of Interest Rate Derivatives Held	1
Derivative, Notional Amount	$2,100,000
Derivative Asset, Fair Value, Gross Asset	$83,000
Derivative, Fixed Interest Rate	5.75%
Derivative, Basis Spread on Variable Rate	2.75%

Fair_Value_Measurements_Tables

Fair Value Measurements - (Tables of Financial Instruments Measured At Fair Value on Recurring Basis) (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]	'	'
Total assets at fair value	$1,889,962	$1,718,028
Total liabilities at fair value	37,563	36,732
Other Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	419	419
Warrant Liability [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	5,599	5,461
Clawback Liability [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	31,964	31,271
Investment Securities Available-For-Sale [Member] | U.S. Treasury Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	'	300
Investment Securities Available-For-Sale [Member] | Asset Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	20,098	90,003
Mortgage-Backed Securities (MBS) [Member] | Residential Mortgage Pass-Through Securities Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	523,183	678,017
Mortgage-Backed Securities (MBS) [Member] | Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	1,346,262	949,289
Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	0	300
Total liabilities at fair value	0	0
Level 1 [Member] | Other Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	0	0
Level 1 [Member] | Warrant Liability [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	0	0
Level 1 [Member] | Clawback Liability [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	0	0
Level 1 [Member] | Investment Securities Available-For-Sale [Member] | U.S. Treasury Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	'	300
Level 1 [Member] | Investment Securities Available-For-Sale [Member] | Asset Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	0	0
Level 1 [Member] | Mortgage-Backed Securities (MBS) [Member] | Residential Mortgage Pass-Through Securities Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	0	0
Level 1 [Member] | Mortgage-Backed Securities (MBS) [Member] | Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	0	0
Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	1,889,543	1,717,309
Total liabilities at fair value	0	0
Level 2 [Member] | Other Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	0	0
Level 2 [Member] | Warrant Liability [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	0	0
Level 2 [Member] | Clawback Liability [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	0	0
Level 2 [Member] | Investment Securities Available-For-Sale [Member] | U.S. Treasury Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	'	0
Level 2 [Member] | Investment Securities Available-For-Sale [Member] | Asset Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	20,098	90,003
Level 2 [Member] | Mortgage-Backed Securities (MBS) [Member] | Residential Mortgage Pass-Through Securities Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	523,183	678,017
Level 2 [Member] | Mortgage-Backed Securities (MBS) [Member] | Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	1,346,262	949,289
Level 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	419	419
Total liabilities at fair value	37,563	36,732
Level 3 [Member] | Other Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	419	419
Level 3 [Member] | Warrant Liability [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	5,599	5,461
Level 3 [Member] | Clawback Liability [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities at fair value	31,964	31,271
Level 3 [Member] | Investment Securities Available-For-Sale [Member] | U.S. Treasury Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	'	0
Level 3 [Member] | Investment Securities Available-For-Sale [Member] | Asset Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	0	0
Level 3 [Member] | Mortgage-Backed Securities (MBS) [Member] | Residential Mortgage Pass-Through Securities Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	0	0
Level 3 [Member] | Mortgage-Backed Securities (MBS) [Member] | Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets at fair value	$0	$0

Fair_Value_Measurements_Table_

Fair Value Measurements - (Table of Changes in Level 3 Financial Instruments) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Warrant [Member]	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'
Beginning Balance	$5,461
Change in value	138
Accretion	0
Settlement	0
Net change in Level 3	138
Ending Balance	5,599
Clawback Liability [Member]	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'
Beginning Balance	31,271
Change in value	-244
Accretion	937
Settlement	0
Net change in Level 3	693
Ending Balance	$31,964

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
	SecurityLoan
	Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Number of comparable companies for expected volatility	9	'
Measuring period for payments to the FDIC	'45 days	'
Number of Loans measured	28	'
Nonrecurring Loans Reserves	$600,000	'
Impairments	9,142,000	8,638,000
Additions [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Number of Loans measured	11	'
Nonrecurring Loans Reserves	600,000	'
Nonrecurring Loans Carrying value	10,000,000	'
Eliminations [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Number of Loans measured	27	'
Nonrecurring Loans Reserves	1,900,000	'
FDIC [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Other Real Estate Owned Impairments Covered by the FDIC	$6,600,000	'
Percentage of OREO impairments covered by the FDIC	73.20%	'

Fair_Value_Measurements_Inputs

Fair Value Measurements - (Inputs Used to Determine Fair Values of Oreo are Considered Level 3 Inputs in Fair Value Hierarchy) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Losses From Fair Value Changes	$9,049
Other real estate owned [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets, Fair Value Disclosure, Nonrecurring	70,753
Impaired loans [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets, Fair Value Disclosure, Nonrecurring	29,075
Losses From Fair Value Changes	1,305
Level 1 [Member] | Other real estate owned [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets, Fair Value Disclosure, Nonrecurring	0
Level 1 [Member] | Impaired loans [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets, Fair Value Disclosure, Nonrecurring	0
Level 2 [Member] | Other real estate owned [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets, Fair Value Disclosure, Nonrecurring	0
Level 2 [Member] | Impaired loans [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets, Fair Value Disclosure, Nonrecurring	0
Level 3 [Member] | Other real estate owned [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets, Fair Value Disclosure, Nonrecurring	70,753
Level 3 [Member] | Impaired loans [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets, Fair Value Disclosure, Nonrecurring	$29,075

Fair_Value_Measurements_Table_1

Fair Value Measurements - (Table of Valuation Techniques and Unobservable Inputs Used in Valuation of Financial Instruments Falling Within Level 3 of Fair Value Hierarchy) (Detail) (USD $)

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Other Securities [Member]

Impaired loans [Member]

Clawback Liability [Member]

Warrant Liability [Member]

Discounted Cash Flows [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Appraised value [Member]

Contractually Defined [Member]

Discounted Cash Flows [Member]

Black-Scholes [Member]

Appraised value [Member]

Contractually Defined [Member]

Discounted Cash Flows [Member]

Black-Scholes [Member]

Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total assets at fair value

$1,889,962,000

$1,718,028,000

$419,000

'

'

'

'

'

'

'

'

'

'

'

'

Total liabilities at fair value

37,563,000

36,732,000

'

29,075,000

31,964,000

5,599,000

'

'

'

'

'

'

'

'

'

Appraised values Discount rate

'

'

'

'

'

'

'

0.00%

'

'

'

25.00%

'

'

'

Intrinsic loss estimates

'

'

'

'

'

'

'

'

323,300,000

'

'

'

405,000,000

'

'

Asset purchase premium

'

'

'

'

'

'

'

'

'

$98,000,000

'

'

'

$182,700,000

'

Discount rate

'

'

'

'

'

'

4.00%

'

'

'

'

'

'

'

'

Discount period

'

'

'

'

'

'

'

'

'

'25 months

'

'

'

'37 months

'

Volatility

'

'

'

'

'

'

'

'

'

'

16.00%

'

'

'

49.00%

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - (Schedule of Fair Value of Financial Instruments) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
ASSETS:	'	'	'	'
Cash and cash equivalents	$349,244	$769,180	$664,699	$1,628,137
Securities purchased under agreements to resell	75,000	0	'	'
Investment securities available-for-sale (at fair value)	1,889,962	1,718,028	'	'
Mortgage-backed securitiesbresidential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	664,717	577,486	'	'
Loans held-for-sale	5,265	5,368	'	'
LIABILITIES:	'	'	'	'
Time deposits	1,534,390	1,752,718	'	'
Securities sold under agreements to repurchase	116,471	53,685	'	'
Due to FDIC	31,964	31,271	'	'
U.S. Treasury Securities [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	'	300	'	'
Asset Backed Securities [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	20,098	90,003	'	'
Residential Mortgage Pass-Through Securities Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	523,183	678,017	'	'
Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	1,346,262	949,289	'	'
Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member] | Level 2 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Mortgage-backed securitiesbresidential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	131,114	0	'	'
Other Securities [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	419	419	'	'
Carrying Amount [Member] | Level 1 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Cash and cash equivalents	349,244	769,180	'	'
Carrying Amount [Member] | Level 2 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Securities purchased under agreements to resell	75,000	0	'	'
Capital stock of FHLB	6,705	7,976	'	'
Capital stock of FRB	25,020	25,020	'	'
Loans held-for-sale	5,265	5,368	'	'
Accrued interest receivable	11,670	12,673	'	'
LIABILITIES:	'	'	'	'
Deposit transaction accounts	2,417,113	2,448,001	'	'
Time deposits	1,534,390	1,752,718	'	'
Securities sold under agreements to repurchase	116,471	53,685	'	'
Accrued interest payable	3,225	4,239	'	'
Carrying Amount [Member] | Level 3 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Loans receivable, net	1,731,394	1,817,322	'	'
LIABILITIES:	'	'	'	'
Due to FDIC	31,964	31,271	'	'
Warrant liability	5,599	5,461	'	'
Carrying Amount [Member] | U.S. Treasury Securities [Member] | Level 1 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	0	300	'	'
Carrying Amount [Member] | Asset Backed Securities [Member] | Level 2 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	20,098	90,003	'	'
Carrying Amount [Member] | Residential Mortgage Pass-Through Securities Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member] | Level 2 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	523,183	678,017	'	'
Mortgage-backed securitiesbresidential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	530,406	577,486	'	'
Carrying Amount [Member] | Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member] | Level 2 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	1,346,262	949,289	'	'
Mortgage-backed securitiesbresidential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	134,311	0	'	'
Carrying Amount [Member] | Other Securities [Member] | Level 3 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	419	419	'	'
Estimated Fair Value [Member] | Level 1 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Cash and cash equivalents	349,244	769,180	'	'
Estimated Fair Value [Member] | Level 2 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Securities purchased under agreements to resell	75,016	0	'	'
Capital stock of FHLB	6,705	7,976	'	'
Capital stock of FRB	25,020	25,020	'	'
Loans held-for-sale	5,265	5,368	'	'
Accrued interest receivable	11,670	12,673	'	'
LIABILITIES:	'	'	'	'
Deposit transaction accounts	2,417,113	2,448,001	'	'
Time deposits	1,538,608	1,759,886	'	'
Securities sold under agreements to repurchase	116,471	53,685	'	'
Accrued interest payable	3,225	4,239	'	'
Estimated Fair Value [Member] | Level 3 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Loans receivable, net	1,742,595	1,829,987	'	'
LIABILITIES:	'	'	'	'
Due to FDIC	31,964	31,271	'	'
Warrant liability	5,599	5,461	'	'
Estimated Fair Value [Member] | U.S. Treasury Securities [Member] | Level 1 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	0	300	'	'
Estimated Fair Value [Member] | Asset Backed Securities [Member] | Level 2 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	20,098	90,003	'	'
Estimated Fair Value [Member] | Residential Mortgage Pass-Through Securities Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member] | Level 2 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	523,183	678,017	'	'
Mortgage-backed securitiesbresidential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	533,464	584,551	'	'
Estimated Fair Value [Member] | Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member] | Level 2 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	1,346,262	949,289	'	'
Estimated Fair Value [Member] | Other Securities [Member] | Level 3 [Member]	'	'	'	'
ASSETS:	'	'	'	'
Investment securities available-for-sale (at fair value)	$419	$419	'	'

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments - (Additional Information) (Detail)	9 Months Ended
	Sep. 30, 2013
Fair Value Of Financial Instruments [Abstract]	'
Residential mortgage loans held for sale period	'45 days

Banking_Center_Closures_Detail

Banking Center Closures - (Details) (USD $)	3 Months Ended		9 Months Ended			0 Months Ended				0 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
						Banking Center Closures [Member]	Banking Center Closures [Member]	Banking Center Closures [Member]	Banking Center Closures [Member]	Banking Center Closure Related Expenses [Member]
						Valuation Allowance, Real Estate Owned [Member]	Lease Agreements [Member]	Limited-Service Retirement Centers [Member]	California Banking Centers [Member]	Banking Center Closures [Member]
								Center	Center	Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'	'	'	'	'
Number of Real Estate Properties	'	'	'	'	'	'	'	32	4	'
Business Exit Costs	'	'	'	'	'	'	'	'	'	$3,400,000
Banking center closure related expenses	3,389,000	0	3,389,000	0	'	'	'	'	'	3,300,000
Other Restructuring Costs	'	'	2,531,000	0	'	2,500,000	800,000	'	'	'
Total Loans	1,742,813,000	1,929,526,000	1,742,813,000	1,929,526,000	1,832,702,000	'	'	'	200,000	'
Deposits	$3,951,503,000	'	$3,951,503,000	'	$4,200,719,000	'	'	$94,000,000	$65,800,000	'

Subsequent_Events_Details

Subsequent Events - (Details) (Subsequent Event [Member], USD $)	0 Months Ended
In Millions, except Share data, unless otherwise specified	Nov. 07, 2013	Nov. 01, 2013	Oct. 23, 2013
Subsequent Event [Line Items]	'	'	'
Cash Dividends Paid to Parent Company	'	'	$313
Stock Repurchased During Period, Shares	756,126	5,015,000	'
Stock Repurchased During Period, Percentage of Stock Outstanding	1.60%	9.80%	'
Treasury Stock Acquired, Average Cost Per Share	$20	$20	'
Stock Repurchased During Period, Value	15.1	100.3	'
Common Class A [Member]	'	'	'
Subsequent Event [Line Items]	'	'	'
Stock Repurchased During Period, Shares	'	2,175,155	'
Common Class B [Member]	'	'	'
Subsequent Event [Line Items]	'	'	'
Stock Repurchased During Period, Shares	'	2,839,845	'
Office of the Comptroller of the Currency [Member]	'	'	'
Subsequent Event [Line Items]	'	'	'
Approval from regulators to permanently reduce capital	'	'	$313